<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "journalpublishing3.dtd">
<article xml:lang="en" article-type="research-article" xmlns:xlink="http://www.w3.org/1999/xlink">
<?release-delay 0|0?>
<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">OL</journal-id>
<journal-title-group>
<journal-title>Oncology Letters</journal-title>
</journal-title-group>
<issn pub-type="ppub">1792-1074</issn>
<issn pub-type="epub">1792-1082</issn>
<publisher>
<publisher-name>D.A. Spandidos</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3892/ol.2018.9663</article-id>
<article-id pub-id-type="publisher-id">OL-0-0-9663</article-id>
<article-categories>
<subj-group>
<subject>Articles</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Variation of nicotinic subtype &#x03B1;7 and muscarinic subtype M3 acetylcholine receptor expression in three main types of leukemia</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author"><name><surname>Suriyo</surname><given-names>Tawit</given-names></name>
<xref rid="af1-ol-0-0-9663" ref-type="aff">1</xref>
<xref rid="af2-ol-0-0-9663" ref-type="aff">2</xref></contrib>
<contrib contrib-type="author"><name><surname>Chotirat</surname><given-names>Sadudee</given-names></name>
<xref rid="af1-ol-0-0-9663" ref-type="aff">1</xref></contrib>
<contrib contrib-type="author"><name><surname>Auewarakul</surname><given-names>Chirayu U.</given-names></name>
<xref rid="af3-ol-0-0-9663" ref-type="aff">3</xref>
<xref rid="af4-ol-0-0-9663" ref-type="aff">4</xref></contrib>
<contrib contrib-type="author"><name><surname>Chaiyot</surname><given-names>Karnjana</given-names></name>
<xref rid="af1-ol-0-0-9663" ref-type="aff">1</xref></contrib>
<contrib contrib-type="author"><name><surname>Promsuwicha</surname><given-names>Orathai</given-names></name>
<xref rid="af4-ol-0-0-9663" ref-type="aff">4</xref></contrib>
<contrib contrib-type="author"><name><surname>Satayavivad</surname><given-names>Jutamaad</given-names></name>
<xref rid="af1-ol-0-0-9663" ref-type="aff">1</xref>
<xref rid="af2-ol-0-0-9663" ref-type="aff">2</xref>
<xref rid="af5-ol-0-0-9663" ref-type="aff">5</xref>
<xref rid="c1-ol-0-0-9663" ref-type="corresp"/></contrib>
</contrib-group>
<aff id="af1-ol-0-0-9663"><label>1</label>Laboratory of Pharmacology, Chulabhorn Research Institute, Bangkok 10210, Thailand</aff>
<aff id="af2-ol-0-0-9663"><label>2</label>Center of Excellence on Environmental Health and Toxicology, Office of Higher Education Commission, Ministry of Education, Bangkok 10400, Thailand</aff>
<aff id="af3-ol-0-0-9663"><label>3</label>Faculty of Medicine and Public Health, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok 10210, Thailand</aff>
<aff id="af4-ol-0-0-9663"><label>4</label>Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand</aff>
<aff id="af5-ol-0-0-9663"><label>5</label>Environmental Toxicology Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand</aff>
<author-notes>
<corresp id="c1-ol-0-0-9663"><italic>Correspondence to</italic>: Dr Jutamaad Satayavivad, Laboratory of Pharmacology, Chulabhorn Research Institute, 54 Kamphaeng Phet 6, Laksi, Bangkok 10210, Thailand, E-mail: <email>jutamaad@cri.or.th</email></corresp>
</author-notes>
<pub-date pub-type="ppub">
<month>01</month>
<year>2019</year></pub-date>
<pub-date pub-type="epub">
<day>05</day>
<month>11</month>
<year>2018</year></pub-date>
<volume>17</volume>
<issue>1</issue>
<fpage>1357</fpage>
<lpage>1362</lpage>
<history>
<date date-type="received"><day>19</day><month>02</month><year>2018</year></date>
<date date-type="accepted"><day>26</day><month>10</month><year>2018</year></date>
</history>
<permissions>
<copyright-statement>Copyright &#x00A9; 2019, Spandidos Publications</copyright-statement>
<copyright-year>2019</copyright-year>
</permissions>
<abstract>
<p>Cholinergic receptors, such as &#x03B1;7-nicotinic acetylcholine receptor (&#x03B1;7-nAChR) and M3-muscarinic acetylcholine receptor (M3-mAChR), have been demonstrated to serve a significant role in the proliferation, differentiation and apoptosis of leukemic cells. However, the expression of these receptors in samples from patients with leukemia remains unclear. The present study aimed to determine the expression of M3-mAChR and &#x03B1;7-nAChR in the bone marrow or peripheral blood of 51 patients with leukemia, including acute myeloid leukemia (AML; n=33), acute lymphoblastic leukemia (ALL; n=13), and chronic myeloid leukemia (CML; n=5). Peripheral blood mononuclear cells (PBMCs) were also isolated from healthy subjects (n=5) for comparison. Western blot analysis was performed to determine the protein expression profiles, and a pattern of decreased &#x03B1;7-nAChR levels in patients with leukemia was observed. Among the leukemia types, the lowest expression of &#x03B1;7-nAChR and M3-mAChR were identified in patients with T-cell ALL/lymphoma (T-ALL). CML exhibited the highest level of M3-mAChR, which was significantly different from APL and AML-M4, yet not from healthy subjects (P&#x003C;0.05). Therefore, different expression profiles of &#x03B1;7-nACR and M3-mAChR were detected amongst the leukemia types. Collectively, the present study supports the potential role of cholinergic signaling in mediating leukemogenesis. However, further studies in larger cohorts are required to validate these findings.</p>
</abstract>
<kwd-group>
<kwd>&#x03B1;7-nicotinic acetylcholine receptor</kwd>
<kwd>M3-muscarinic acetylcholine receptor</kwd>
<kwd>acute myeloid leukemia</kwd>
<kwd>acute lymphoblastic leukemia</kwd>
<kwd>chronic myeloid leukemia</kwd>
</kwd-group>
</article-meta>
</front>
<body>
<sec sec-type="intro">
<title>Introduction</title>
<p>Leukemia includes a group of heterogeneous neoplastic malignancies that develop in the bone marrow and affect normal hematopoiesis. Conventionally, leukemia has been classified according to its cellular origin, whether of myeloid or lymphoid lineage, and by the course of the illness, whether acute or chronic. The four major types are acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), and chronic lymphocytic leukemia (CLL). They differ significantly in terms of the morphological, cytogenetic, immunophenotypic, and molecular features of the malignant cells (<xref rid="b1-ol-0-0-9663" ref-type="bibr">1</xref>). The French-American-British (FAB) classification divides AML into nine subtypes, identified as M0 through M7. These nine are based on the level of maturity of the myeloid cells. The category of undifferentiated AML, or M0, reflects the difficulty in delineating whether a cancer cell is truly a myeloid-type or a lymphoid-type malignancy when it presents neither myeloid nor lymphoid markers (<xref rid="b2-ol-0-0-9663" ref-type="bibr">2</xref>). These specific characteristics of leukemia suggest the heterogeneity of the underlying biological alterations involved in cancer cell transformation and the variations in the levels of hematopoietic progenitor cell hierarchy.</p>
<p>Acetylcholine (ACh) is a major central and peripheral neurotransmitter and is also involved in the control of several non-neuronal functions, including immune function (<xref rid="b3-ol-0-0-9663" ref-type="bibr">3</xref>). Immune cells, especially lymphocytes, express essential components of the non-neuronal cholinergic system. They include the chemical messenger, ACh; the ACh-synthesizing enzyme, choline acetyltransferase (ChAT); an ACh-degrading enzyme, acetylcholinesterase (AChE); and both muscarinic (m) and nicotinic (n) ACh receptors (AChRs) (<xref rid="b4-ol-0-0-9663" ref-type="bibr">4</xref>). There is accumulating evidence for the involvement of the non-neuronal cholinergic pathway in regulating and modulating the immune system by means of its effects on the differentiation and proliferation of lymphocytes, cytokine production, antigen presentation, and inflammation (<xref rid="b5-ol-0-0-9663" ref-type="bibr">5</xref>).</p>
<p>Several studies on the involvement of the non-neuronal cholinergic pathway in tumorigenesis have been published, including lung, colon, cervix, prostate, breast, and bile duct cancers, wherein more information regarding cholinergic autocrine and paracrine signaling is available (<xref rid="b6-ol-0-0-9663" ref-type="bibr">6</xref>&#x2013;<xref rid="b9-ol-0-0-9663" ref-type="bibr">9</xref>). Molecular analyses of the expression of essential cholinergic components in malignant tumors of different histogenesis have indicated that those tumors largely exhibit different cholinergic component expression from normal tissue (<xref rid="b10-ol-0-0-9663" ref-type="bibr">10</xref>). In addition, enhancement of ACh production has often been observed in tumors as well as some differences in the expression patterns of ACh receptors. Among the various types of cholinergic AChRs, subtype &#x03B1;7 nAChR (&#x03B1;7-nAChR) and subtype M3 mAChR receptor (M3-mAChR) have been identified as the cholinergic AChRs most capable of promoting cancer progression, for example, by the induction of cancer cell growth and metastasis (<xref rid="b6-ol-0-0-9663" ref-type="bibr">6</xref>,<xref rid="b9-ol-0-0-9663" ref-type="bibr">9</xref>,<xref rid="b11-ol-0-0-9663" ref-type="bibr">11</xref>).</p>
<p>Previous studies have demonstrated the downregulation of certain types of cholinergic ACh receptors during the thymocyte maturation process, denoting their possible role in T-cell development (<xref rid="b12-ol-0-0-9663" ref-type="bibr">12</xref>). Furthermore, the plasticity of cholinergic AChRs during T-cell differentiation has also been demonstrated in murine splenic T-cell models (<xref rid="b13-ol-0-0-9663" ref-type="bibr">13</xref>). Extensive data obtained from human mononuclear leukocytes (MNLs), isolated T- and B-cells, and various leukemia cell lines, have revealed the diversity of the non-neuronal cholinergic system, particularly of cholinergic AChRs in human immune cells (<xref rid="b14-ol-0-0-9663" ref-type="bibr">14</xref>,<xref rid="b15-ol-0-0-9663" ref-type="bibr">15</xref>). Our previous <italic>in vitro</italic> study of NB-4 acute promyeolocytic leukemic cells also demonstrated that the expression of &#x03B1;7-nAChR and M3-mAChR changes following all-trans retinoic acid-induced differentiation treatment (<xref rid="b16-ol-0-0-9663" ref-type="bibr">16</xref>). In addition, induction of AChE activity was evident in whole blood and lymphocyte samples obtained from newly diagnosed pediatric patients with T- or B-ALL. However, AChE activity decreased during the remission period (<xref rid="b17-ol-0-0-9663" ref-type="bibr">17</xref>). It is important to note the recent hypothesis that non-neuronal cholinergic machinery may be involved in leukemogenesis, especially in T-cell leukemia, and that its components, such as cholinergic AChRs, may represent relevant therapeutic targets for leukemia (<xref rid="b18-ol-0-0-9663" ref-type="bibr">18</xref>). To date, there has been no new information regarding the involvement of the non-neuronal cholinergic system amongst different types of leukemia. We propose that the expression patterns of cholinergic systems may differ among the types and subtypes of leukemia. In the present study, we compared the expression levels of the major cholinergic AChRs, including &#x03B1;7-nAChR and M3-mAChR, in healthy subjects and in patients with the three main types of leukemia, to reveal the potentiality of the cholinergic pathway as a pharmacological target in hematopoietic derived neoplasia.</p>
</sec>
<sec sec-type="materials|methods">
<title>Materials and methods</title>
<sec>
<title/>
<sec>
<title>Patients</title>
<p>Inclusion criteria for the subjects were as follows: i) Diagnosis of leukemia at Siriraj Hospital (Bangkok, Thailand); ii) patients with leukemia were in the novel diagnostic-phase and not undergoing treatment that might influence the expression of cholinergic AChRs in lymphocytes; iii) written informed consent was obtained. The exclusion criteria were as follows: i) Presence of multiple tumors; ii) being pregnant or too young (age &#x003C;15 years); iii) presence of acute or chronic diseases such as diabetes, parasitosis or any immune dysfunction. The exclusions were intended to minimize potential complications due to the impact of these complex diseases on immune cells. This study was conducted in accordance with the provisions of the International Conference on Harmonization of Good Clinical Practice guidelines and the Helsinki Declaration. The study was approved by the Committee on Human Rights Related to Research Involving Human Subjects of the Chulabhorn Research Institute (CRI project number: 33/2554, approval date: 29/02/2012) and the Ethics Committee of Siriraj Hospital (Project number: 255/2555, approval date: 01/08/2012). Written informed consent was obtained from each patient prior to sample collection. A total of 51 peripheral blood (PB) or bone marrow (BM) samples were obtained from patients at the time of diagnosis between 01/2013 and 12/2016. PB samples were also taken from healthy subjects (n=5) to serve as a control group. The peripheral blood mononuclear cells (PBMCs) of patients with leukemia and healthy subjects were isolated from 6 ml of heparinized venous blood by density gradient centrifugation using Ficoll-Paque (Isoprep; Robbins Scientific, Sunnyvale, CA, USA) at 500 &#x00D7; g for 30 min. The mononuclear cells were washed three times in Hank&#x0027;s balanced salt solution (Gibco-Invitrogen; Thermo Fisher Scientific, Inc., Waltham, MA, USA).</p>
</sec>
<sec>
<title>Western immunoblotting assay</title>
<p>PBMCs and BM samples were lysed in lysis buffer containing 10 mM Tris-HCl, pH 7.4, 150 mM NaCl, 1 mM Na<sub>3</sub>VO<sub>4</sub>, 20 mM NaF, 1 mM PMSF, 1&#x0025; Triton X-100, and 1X protease inhibitor cocktail set I (Calbiochem; Merck KGaA, Darmstadt, Germany). Sample lysates were sonicated and then incubated at 4&#x00B0;C for 30 min. Samples were centrifuged at 16,000 &#x00D7; g for 15 min at 4&#x00B0;C. Sample supernatants were collected and stored at &#x2212;80&#x00B0;C for further analysis. Concentrations of proteins in the supernatants were determined by using a Bradford assay (Bio-Rad Laboratories, Inc., Hercules, CA, USA). The sample (50 &#x00B5;g total protein) was mixed with Laemmli loading buffer (62.5 mM Tris-HCl pH 6.8, 2&#x0025; SDS, 25&#x0025; glycerol, 0.01&#x0025; bromophenol blue, and 5&#x0025; 2-mercaptoethanol) and then boiled at 95&#x00B0;C for 5 min. Proteins were separated via 7.5&#x0025; SDS-PAGE in a Mini-PROTEAN II system (Bio-Rad Laboratories, Inc.). The separated proteins were then transferred onto a nitrocellulose membrane (GE Healthcare Life Sciences, Little Chalfont, UK), and the membrane was incubated in blocking buffer containing 5&#x0025; non-fat dry milk in TBS-T buffer (10 mM Tris-HCl, pH 8.0, 0.05&#x0025; Tween-20, and 150 mM NaCl) for 1 h at room temperature, followed by overnight incubation at 4&#x00B0;C with the primary antibodies. Antibodies against &#x03B1;7-nAChR (sc-5544; 1:1,000) and M3-mAChR (sc-9108; 1:500) were obtained from Santa Cruz Biotechnology (Dallas, TX, USA). The antibody against GAPDH (2118; 1:2,000) was purchased from Cell Signaling Technology, Inc. (Danvers, MA, USA). After washing with TBS-T buffer 3 times (10 min each), the membrane was incubated with a horseradish-peroxidase conjugated secondary antibody (GE Healthcare Life Sciences) for 2 h at room temperature. The protein bands stained by the targeted antibodies were visualized using an enhanced chemiluminescence assay kit (GE Healthcare Life Sciences) followed by exposure to x-ray film (Pierce, Perbio, Brazil). To avoid variation between gels, the exposure time of &#x03B1;7-nAChR, M3-mAChR, and GAPDH, was fixed at 2, 20, and 2 min, respectively. Relative protein expression levels of &#x03B1;7-nAChR and M3-mAChR were calculated from the band intensities using computerized densitometry with ImageQuantTL software (GE Healthcare Life Sciences). Notably, the M3-mAChR immunoblot had two bands, which were considered and quantified as M3-mAChR in accordance with a previous study (<xref rid="b19-ol-0-0-9663" ref-type="bibr">19</xref>).</p>
</sec>
<sec>
<title>Statistical analysis</title>
<p>All data are expressed as the means &#x00B1; standard deviation (SD). To determine whether the data set was normally distributed, a Shapiro-Wilk normality test was performed. As some groups contained only small sample numbers, statistically significant differences were assessed using the non-parametric Kruskal-Wallis one-way analysis of variance for rank with the post hoc Dunn&#x0027;s test. A P-value &#x003C;0.05 is considered to indicate a statistically significant difference.</p>
</sec>
</sec>
</sec>
<sec sec-type="results">
<title>Results</title>
<sec>
<title/>
<sec>
<title>Patient characteristics</title>
<p>The study included 5 healthy subjects and 51 patients with leukemia [AML (n=33), CML (n=5), and ALL (n=13)]. According to the WHO classification (<xref rid="b2-ol-0-0-9663" ref-type="bibr">2</xref>), AML cases were further classified into subtypes: AML with minimal differentiation (AML-M0; n=6), AML without maturation (AML-M1; n=5), AML with maturation (AML-M2; n=8), acute promyelocytic leukemia (AML-M3; n=6), or acute myelomonocytic leukemia (AML-M4; n=8). ALL was further classified as T lymphoblastic leukemia/lymphoma (T-ALL; n=9), and B lymphoblastic leukemia/lymphoma (B-ALL; n=4). Clinical characteristics are listed in <xref rid="tI-ol-0-0-9663" ref-type="table">Table I</xref>. AML and ALL occur in children as well as in adults (subject age range 15&#x2013;85) but CML has only been found in adults (subject age range 26&#x2013;57). Hemoglobin levels and percentages of hematocrit in all groups of leukemia seem to be relatively lower than in healthy subjects. As predicted, the white blood cell count (WBC) was higher; meanwhile the platelet count was much lower in the patients with leukemia than in the healthy subject group.</p>
</sec>
<sec>
<title>Expression levels of &#x03B1;7-nAChR and M3-mAChR in patients with leukemia</title>
<p>Expression levels of &#x03B1;7-nAChR in PBMCs or BM in different types of patients with leukemia were compared with healthy subjects. It might be expected that all types of patients with leukemia would have lower expression levels of &#x03B1;7-nAChR than healthy subjects, but significant expression levels were observed in T-ALL, CML, AML-M40 and AML-M4 (<xref rid="f1-ol-0-0-9663" ref-type="fig">Fig. 1</xref> and <xref rid="tII-ol-0-0-9663" ref-type="table">Table II</xref>). The expression level of &#x03B1;7-nAChR was lowest in T-ALL, significantly different from in AML-M1, AML-M2 and AML-M4.</p>
<p>Regarding M3-mAChR expression, the results showed a large variation in M3-mAChR expression among leukemia types (<xref rid="f2-ol-0-0-9663" ref-type="fig">Fig. 2</xref> and <xref rid="tII-ol-0-0-9663" ref-type="table">Table II</xref>). The expression level of M3-mAChR was lowest in T-ALL, significantly different from in B-ALL, CML, AML-M1 and AML-M2. In addition, CML showed the highest level of M3-mAChR, significantly different from in APL and AML-M4. Notably, there was no significant difference between expression in the control group any in type of leukemia types.</p>
</sec>
</sec>
</sec>
<sec sec-type="discussion">
<title>Discussion</title>
<p>The putative involvement of the non-neuronal cholinergic system in the etiology of hematopoietic derived neoplasia is of particular importance in view of various recent reports (<xref rid="b16-ol-0-0-9663" ref-type="bibr">16</xref>&#x2013;<xref rid="b18-ol-0-0-9663" ref-type="bibr">18</xref>). Several studies have provided evidence demonstrating that blood cells, especially lymphocytes, possess non-neuronal cholinergic components including cholinergic AChRs (<xref rid="b14-ol-0-0-9663" ref-type="bibr">14</xref>,<xref rid="b20-ol-0-0-9663" ref-type="bibr">20</xref>). Our results showed a variation of cholinergic AChRs, including &#x03B1;7-nAChR and M3-AChR, in the BM or PBMC samples from patients with the three main types of leukemia: AML, ALL, and CML. In detail, &#x03B1;7-nAChR in T-ALL, CML, but not B-ALL, were lower in patients with leukemia than in healthy subjects. It has been reported that cholinergic signals regulate thymic differentiation and selection (<xref rid="b21-ol-0-0-9663" ref-type="bibr">21</xref>). Furthermore, previous studies have shown that &#x03B1;7-nAChR is involved in both T and B lymphocyte development in the bone marrow and spleen (<xref rid="b22-ol-0-0-9663" ref-type="bibr">22</xref>). In AML subtypes based on levels of myeloid maturation, variation in &#x03B1;7-nAChR expression was observed. The &#x03B1;7-nAChR expression was lowest in AML-M0 (AML with minimal differentiation); its level of expression increased to a maximum in AML-M1, then continuously declined in AML-M2, APL, and AML-M4. This pattern of variation was also observed in the expression of &#x03B1;4-nAChR subunits during B lymphocyte development in wild-type mice (<xref rid="b22-ol-0-0-9663" ref-type="bibr">22</xref>).</p>
<p>Among AML subtypes, we found that M3-mAChR expression was lowest in APL and AML-M4. Our previous <italic>in vitro</italic> study on the NB-4 acute promyeolocytic leukemic cell line demonstrated that M3-mAChR markedly increases after all-<italic>trans</italic>-retinoic acid-induced differentiation treatment (<xref rid="b16-ol-0-0-9663" ref-type="bibr">16</xref>). Hence, administration of a specific M3-mAChR agonist along with differentiation-inducing drugs may be a potential treatment for the APL subtype. Amongst the leukemia types, the highest expression of M3-mAChR was detected in CML, where most myeloid cells are mature. Collectively, these observations support the association of M3-mAChR in myeloid maturation. It is notable that in previous studies of the CML K562 cell line, muscarinic receptor activation stimulated intracellular cAMP, decreased c-Fos and cyclin D1 expression, and inhibited cell proliferation (<xref rid="b19-ol-0-0-9663" ref-type="bibr">19</xref>,<xref rid="b23-ol-0-0-9663" ref-type="bibr">23</xref>). Altogether, mAChR activation by its agonist may also be a potential approach for treatment of CML. However, this hypothesis needs further study.</p>
<p>Previous studies have demonstrated that ACh production in various leukemic T-cell lines, including CEM, Jurkat, HSB-2, MOLT-3, and MOLT-4, was considerably higher compared to fresh PBMCs obtained from healthy subjects (<xref rid="b24-ol-0-0-9663" ref-type="bibr">24</xref>). Moreover, it has been suggested that ACh may not be rapidly hydrolyzed in T-ALL as AChE is decreased in these types of leukemic cells, compared with in mature normal T-cell lymphocytes (<xref rid="b25-ol-0-0-9663" ref-type="bibr">25</xref>). Previous studies have shown that Jurkat, T-cell-derived leukemic cells, increased M3-mAChR expression (<xref rid="b26-ol-0-0-9663" ref-type="bibr">26</xref>). In addition, it has been proposed that high levels of ACh in T-ALL may act as an autocrine growth factor and play a significant role in leukemia T-cell clonal expansion via shaping of intracellular calcium signaling pathways (<xref rid="b18-ol-0-0-9663" ref-type="bibr">18</xref>). However, our study showed the lowest expression of both &#x03B1;7-nAChR and M3-mAChR was in T-ALL patients. It could be hypothesized that the reduction of cholinergic receptors may represent an adaptation mechanism of cholinergic over-activation.</p>
<p>In conclusion, our observations highlight the differential expression profiles of &#x03B1;7-nAChR and M3-mAChR among the three main types of leukemia, and that these expression patterns may mediate leukemogenesis. Moreover, these findings may support the utilization of cholinergic AChRs as potential prognostic markers and alternative therapeutic treatments. However, further studies with larger cohorts, and functional studies, are necessary to elucidate this proposal.</p>
</sec>
</body>
<back>
<ack>
<title>Acknowledgements</title>
<p>The authors would like to thank Assistant Professor Janice M. Wongsurawat of the Chulabhorn Research Institute (Bangkok, Thailand) for proofreading the manuscript.</p>
</ack>
<sec>
<title>Funding</title>
<p>This study was supported by a research grant from Chulabhorn Research Institute (grant no. PH2011-02, 2011).</p>
</sec>
<sec>
<title>Availability of data and materials</title>
<p>All data generated and analyzed during this study are included in this article.</p>
</sec>
<sec>
<title>Authors&#x0027; contributions</title>
<p>TS performed the experiment, analyzed the data, and drafted the manuscript. SC and KC performed the experiments. CUA participated in the design of the study and supervised subject selection and sample collection. OP performed the sample collection. JS was responsible for initiation, conception, experimental design, execution of the entire project and for critical revision of the manuscript. All authors read and approved the final manuscript.</p>
</sec>
<sec>
<title>Ethics approval and consent to participate</title>
<p>The study protocol was approved by the Committee on Human Rights Related to Research Involving Human Subjects of the Chulabhorn Research Institute (CRI project number: 33/2554, approval date: 29/02/2012) and the Ethics Committee of Siriraj Hospital (Project number: 255/2555, approval date: 01/08/2012). All patients provided written informed consent for the publication of data in this study.</p>
</sec>
<sec>
<title>Patient consent for publication</title>
<p>Not applicable.</p>
</sec>
<sec>
<title>Competing interests</title>
<p>The authors declare that they have no competing interests.</p>
</sec>
<ref-list>
<title>References</title>
<ref id="b1-ol-0-0-9663"><label>1</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Jin</surname><given-names>MW</given-names></name><name><surname>Xu</surname><given-names>SM</given-names></name><name><surname>An</surname><given-names>Q</given-names></name><name><surname>Wang</surname><given-names>P</given-names></name></person-group><article-title>A review of risk factors for childhood leukemia</article-title><source>Eur Rev Med Pharmacol Sci</source><volume>20</volume><fpage>3760</fpage><lpage>3764</lpage><year>2016</year><pub-id pub-id-type="pmid">27735044</pub-id></element-citation></ref>
<ref id="b2-ol-0-0-9663"><label>2</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Schlenk</surname><given-names>RF</given-names></name><name><surname>D&#x00F6;hner</surname><given-names>K</given-names></name><name><surname>Krauter</surname><given-names>J</given-names></name><name><surname>Fr&#x00F6;hling</surname><given-names>S</given-names></name><name><surname>Corbacioglu</surname><given-names>A</given-names></name><name><surname>Bullinger</surname><given-names>L</given-names></name><name><surname>Habdank</surname><given-names>M</given-names></name><name><surname>Sp&#x00E4;th</surname><given-names>D</given-names></name><name><surname>Morgan</surname><given-names>M</given-names></name><name><surname>Benner</surname><given-names>A</given-names></name><etal/></person-group><article-title>Mutations and treatment outcome in cytogenetically normal acute myeloid leukemia</article-title><source>N Engl J Med</source><volume>358</volume><fpage>1909</fpage><lpage>1918</lpage><year>2008</year><pub-id pub-id-type="doi">10.1056/NEJMoa074306</pub-id><pub-id pub-id-type="pmid">18450602</pub-id></element-citation></ref>
<ref id="b3-ol-0-0-9663"><label>3</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kawashima</surname><given-names>K</given-names></name><name><surname>Fujii</surname><given-names>T</given-names></name></person-group><article-title>The lymphocytic cholinergic system and its biological function</article-title><source>Life Sci</source><volume>72</volume><fpage>2101</fpage><lpage>2109</lpage><year>2003</year><pub-id pub-id-type="doi">10.1016/S0024-3205(03)00068-7</pub-id><pub-id pub-id-type="pmid">12628464</pub-id></element-citation></ref>
<ref id="b4-ol-0-0-9663"><label>4</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kawashima</surname><given-names>K</given-names></name><name><surname>Fujii</surname><given-names>T</given-names></name></person-group><article-title>Expression of non-neuronal acetylcholine in lymphocytes and its contribution to the regulation of immune function</article-title><source>Front Biosci</source><volume>9</volume><fpage>2063</fpage><lpage>2085</lpage><year>2004</year><pub-id pub-id-type="doi">10.2741/1390</pub-id><pub-id pub-id-type="pmid">15353271</pub-id></element-citation></ref>
<ref id="b5-ol-0-0-9663"><label>5</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Ofek</surname><given-names>K</given-names></name><name><surname>Soreq</surname><given-names>H</given-names></name></person-group><article-title>Cholinergic involvement and manipulation approaches in multiple system disorders</article-title><source>Chem Biol Interact</source><volume>203</volume><fpage>113</fpage><lpage>119</lpage><year>2013</year><pub-id pub-id-type="doi">10.1016/j.cbi.2012.07.007</pub-id><pub-id pub-id-type="pmid">22898318</pub-id></element-citation></ref>
<ref id="b6-ol-0-0-9663"><label>6</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Russo</surname><given-names>P</given-names></name><name><surname>Del Bufalo</surname><given-names>A</given-names></name><name><surname>Milic</surname><given-names>M</given-names></name><name><surname>Salinaro</surname><given-names>G</given-names></name><name><surname>Fini</surname><given-names>M</given-names></name><name><surname>Cesario</surname><given-names>A</given-names></name></person-group><article-title>Cholinergic receptors as target for cancer therapy in a systems medicine perspective</article-title><source>Curr Mol Med</source><volume>14</volume><fpage>1126</fpage><lpage>1138</lpage><year>2014</year><pub-id pub-id-type="doi">10.2174/1566524014666141015152601</pub-id><pub-id pub-id-type="pmid">25324001</pub-id></element-citation></ref>
<ref id="b7-ol-0-0-9663"><label>7</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Paleari</surname><given-names>L</given-names></name><name><surname>Grozio</surname><given-names>A</given-names></name><name><surname>Cesario</surname><given-names>A</given-names></name><name><surname>Russo</surname><given-names>P</given-names></name></person-group><article-title>The cholinergic system and cancer</article-title><source>Semin Cancer Biol</source><volume>18</volume><fpage>211</fpage><lpage>217</lpage><year>2008</year><pub-id pub-id-type="doi">10.1016/j.semcancer.2007.12.009</pub-id><pub-id pub-id-type="pmid">18262434</pub-id></element-citation></ref>
<ref id="b8-ol-0-0-9663"><label>8</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Shah</surname><given-names>N</given-names></name><name><surname>Khurana</surname><given-names>S</given-names></name><name><surname>Cheng</surname><given-names>K</given-names></name><name><surname>Raufman</surname><given-names>JP</given-names></name></person-group><article-title>Muscarinic receptors and ligands in cancer</article-title><source>Am J Physiol Cell Physiol</source><volume>296</volume><fpage>C221</fpage><lpage>C232</lpage><year>2009</year><pub-id pub-id-type="doi">10.1152/ajpcell.00514.2008</pub-id><pub-id pub-id-type="pmid">19036940</pub-id></element-citation></ref>
<ref id="b9-ol-0-0-9663"><label>9</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Campoy</surname><given-names>FJ</given-names></name><name><surname>Vidal</surname><given-names>CJ</given-names></name><name><surname>Munoz-Delgado</surname><given-names>E</given-names></name><name><surname>Montenegro</surname><given-names>MF</given-names></name><name><surname>Cabezas-Herrera</surname><given-names>J</given-names></name><name><surname>Nieto-Cer&#x00F3;n</surname><given-names>S</given-names></name></person-group><article-title>Cholinergic system and cell proliferation</article-title><source>Chem Biol Interact</source><volume>259</volume><fpage>257</fpage><lpage>265</lpage><year>2016</year><pub-id pub-id-type="doi">10.1016/j.cbi.2016.04.014</pub-id><pub-id pub-id-type="pmid">27083142</pub-id></element-citation></ref>
<ref id="b10-ol-0-0-9663"><label>10</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Spindel</surname><given-names>ER</given-names></name></person-group><article-title>Muscarinic receptor agonists and antagonists: Effects on cancer</article-title><source>Handb Exp Pharmacol</source><fpage>451</fpage><lpage>468</lpage><year>2012</year><pub-id pub-id-type="doi">10.1007/978-3-642-23274-9_19</pub-id><pub-id pub-id-type="pmid">22222710</pub-id></element-citation></ref>
<ref id="b11-ol-0-0-9663"><label>11</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Dang</surname><given-names>N</given-names></name><name><surname>Meng</surname><given-names>X</given-names></name><name><surname>Song</surname><given-names>H</given-names></name></person-group><article-title>Nicotinic acetylcholine receptors and cancer</article-title><source>Biomed Rep</source><volume>4</volume><fpage>515</fpage><lpage>518</lpage><year>2016</year><pub-id pub-id-type="doi">10.3892/br.2016.625</pub-id><pub-id pub-id-type="pmid">27123240</pub-id></element-citation></ref>
<ref id="b12-ol-0-0-9663"><label>12</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kawashima</surname><given-names>K</given-names></name><name><surname>Fujii</surname><given-names>T</given-names></name><name><surname>Moriwaki</surname><given-names>Y</given-names></name><name><surname>Misawa</surname><given-names>H</given-names></name></person-group><article-title>Critical roles of acetylcholine and the muscarinic and nicotinic acetylcholine receptors in the regulation of immune function</article-title><source>Life Sci</source><volume>91</volume><fpage>1027</fpage><lpage>1032</lpage><year>2012</year><pub-id pub-id-type="doi">10.1016/j.lfs.2012.05.006</pub-id><pub-id pub-id-type="pmid">22659391</pub-id></element-citation></ref>
<ref id="b13-ol-0-0-9663"><label>13</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Qian</surname><given-names>J</given-names></name><name><surname>Galitovskiy</surname><given-names>V</given-names></name><name><surname>Chernyavsky</surname><given-names>AI</given-names></name><name><surname>Marchenko</surname><given-names>S</given-names></name><name><surname>Grando</surname><given-names>SA</given-names></name></person-group><article-title>Plasticity of the murine spleen T-cell cholinergic receptors and their role in in vitro differentiation of na&#x00EF;ve CD4 T cells toward the Th1, Th2 and Th17 lineages</article-title><source>Genes Immun</source><volume>12</volume><fpage>222</fpage><lpage>230</lpage><year>2011</year><pub-id pub-id-type="doi">10.1038/gene.2010.72</pub-id><pub-id pub-id-type="pmid">21270829</pub-id></element-citation></ref>
<ref id="b14-ol-0-0-9663"><label>14</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Sato</surname><given-names>KZ</given-names></name><name><surname>Fujii</surname><given-names>T</given-names></name><name><surname>Watanabe</surname><given-names>Y</given-names></name><name><surname>Yamada</surname><given-names>S</given-names></name><name><surname>Ando</surname><given-names>T</given-names></name><name><surname>Kazuko</surname><given-names>F</given-names></name><name><surname>Kawashima</surname><given-names>K</given-names></name></person-group><article-title>Diversity of mRNA expression for muscarinic acetylcholine receptor subtypes and neuronal nicotinic acetylcholine receptor subunits in human mononuclear leukocytes and leukemic cell lines</article-title><source>Neurosci Lett</source><volume>266</volume><fpage>17</fpage><lpage>20</lpage><year>1999</year><pub-id pub-id-type="doi">10.1016/S0304-3940(99)00259-1</pub-id><pub-id pub-id-type="pmid">10336173</pub-id></element-citation></ref>
<ref id="b15-ol-0-0-9663"><label>15</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Tayebati</surname><given-names>SK</given-names></name><name><surname>El-Assouad</surname><given-names>D</given-names></name><name><surname>Ricci</surname><given-names>A</given-names></name><name><surname>Amenta</surname><given-names>F</given-names></name></person-group><article-title>Immunochemical and immunocytochemical characterization of cholinergic markers in human peripheral blood lymphocytes</article-title><source>J Neuroimmunol</source><volume>132</volume><fpage>147</fpage><lpage>155</lpage><year>2002</year><pub-id pub-id-type="doi">10.1016/S0165-5728(02)00325-9</pub-id><pub-id pub-id-type="pmid">12417445</pub-id></element-citation></ref>
<ref id="b16-ol-0-0-9663"><label>16</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Chotirat</surname><given-names>S</given-names></name><name><surname>Suriyo</surname><given-names>T</given-names></name><name><surname>Hokland</surname><given-names>M</given-names></name><name><surname>Hokland</surname><given-names>P</given-names></name><name><surname>Satayavivad</surname><given-names>J</given-names></name><name><surname>Auewarakul</surname><given-names>CU</given-names></name></person-group><article-title>Cholinergic activation enhances retinoic acid-induced differentiation in the human NB-4 acute promyelocytic leukemia cell line</article-title><source>Blood Cells Mol Dis</source><volume>59</volume><fpage>77</fpage><lpage>84</lpage><year>2016</year><pub-id pub-id-type="doi">10.1016/j.bcmd.2016.04.009</pub-id><pub-id pub-id-type="pmid">27282572</pub-id></element-citation></ref>
<ref id="b17-ol-0-0-9663"><label>17</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Battisti</surname><given-names>V</given-names></name><name><surname>Schetinger</surname><given-names>MR</given-names></name><name><surname>Maders</surname><given-names>LD</given-names></name><name><surname>Santos</surname><given-names>KF</given-names></name><name><surname>Bagatini</surname><given-names>MD</given-names></name><name><surname>Correa</surname><given-names>MC</given-names></name><name><surname>Spanevello</surname><given-names>RM</given-names></name><name><surname>do Carmo Ara&#x00FA;jo</surname><given-names>M</given-names></name><name><surname>Morsch</surname><given-names>VM</given-names></name></person-group><article-title>Changes in acetylcholinesterase (AchE) activity in lymphocytes and whole blood in acute lymphoblastic leukemia patients</article-title><source>Clin Chim Acta</source><volume>402</volume><fpage>114</fpage><lpage>118</lpage><year>2009</year><pub-id pub-id-type="doi">10.1016/j.cca.2008.12.030</pub-id><pub-id pub-id-type="pmid">19185568</pub-id></element-citation></ref>
<ref id="b18-ol-0-0-9663"><label>18</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Dobrovinskaya</surname><given-names>O</given-names></name><name><surname>Valencia-Cruz</surname><given-names>G</given-names></name><name><surname>Castro-S&#x00E1;nchez</surname><given-names>L</given-names></name><name><surname>Bonales-Alatorre</surname><given-names>EO</given-names></name><name><surname>Li&#x00F1;an-Rico</surname><given-names>L</given-names></name><name><surname>Pottosin</surname><given-names>I</given-names></name></person-group><article-title>Cholinergic machinery as relevant target in acute lymphoblastic T leukemia</article-title><source>Front Pharmacol</source><volume>7</volume><fpage>290</fpage><year>2016</year><pub-id pub-id-type="doi">10.3389/fphar.2016.00290</pub-id><pub-id pub-id-type="pmid">27630569</pub-id></element-citation></ref>
<ref id="b19-ol-0-0-9663"><label>19</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Cabadak</surname><given-names>H</given-names></name><name><surname>Aydin</surname><given-names>B</given-names></name><name><surname>Kan</surname><given-names>B</given-names></name></person-group><article-title>Regulation of M2, M3, and M4 muscarinic receptor expression in K562 chronic myelogenous leukemic cells by carbachol</article-title><source>J Recept Signal Transduct Res</source><volume>31</volume><fpage>26</fpage><lpage>32</lpage><year>2011</year><pub-id pub-id-type="doi">10.3109/10799893.2010.506484</pub-id><pub-id pub-id-type="pmid">20684668</pub-id></element-citation></ref>
<ref id="b20-ol-0-0-9663"><label>20</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Kawashima</surname><given-names>K</given-names></name><name><surname>Fujii</surname><given-names>T</given-names></name></person-group><article-title>Extraneuronal cholinergic system in lymphocytes</article-title><source>Pharmacol Ther</source><volume>86</volume><fpage>29</fpage><lpage>48</lpage><year>2000</year><pub-id pub-id-type="doi">10.1016/S0163-7258(99)00071-6</pub-id><pub-id pub-id-type="pmid">10760545</pub-id></element-citation></ref>
<ref id="b21-ol-0-0-9663"><label>21</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Rinner</surname><given-names>I</given-names></name><name><surname>Globerson</surname><given-names>A</given-names></name><name><surname>Kawashima</surname><given-names>K</given-names></name><name><surname>Korsatko</surname><given-names>W</given-names></name><name><surname>Schauenstein</surname><given-names>K</given-names></name></person-group><article-title>A possible role for acetylcholine in the dialogue between thymocytes and thymic stroma</article-title><source>Neuroimmunomodulation</source><volume>6</volume><fpage>51</fpage><lpage>55</lpage><year>1999</year><pub-id pub-id-type="doi">10.1159/000026364</pub-id><pub-id pub-id-type="pmid">9876235</pub-id></element-citation></ref>
<ref id="b22-ol-0-0-9663"><label>22</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Skok</surname><given-names>M</given-names></name><name><surname>Grailhe</surname><given-names>R</given-names></name><name><surname>Agenes</surname><given-names>F</given-names></name><name><surname>Changeux</surname><given-names>JP</given-names></name></person-group><article-title>The role of nicotinic acetylcholine receptors in lymphocyte development</article-title><source>J Neuroimmunol</source><volume>171</volume><fpage>86</fpage><lpage>98</lpage><year>2006</year><pub-id pub-id-type="doi">10.1016/j.jneuroim.2005.09.011</pub-id><pub-id pub-id-type="pmid">16253349</pub-id></element-citation></ref>
<ref id="b23-ol-0-0-9663"><label>23</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Aydin</surname><given-names>B</given-names></name><name><surname>Kan</surname><given-names>B</given-names></name><name><surname>Cabadak</surname><given-names>H</given-names></name></person-group><article-title>The role of intracellular pathways in the proliferation of human K562 cells mediated by muscarinic receptors</article-title><source>Leuk Res</source><volume>37</volume><fpage>1144</fpage><lpage>1149</lpage><year>2013</year><pub-id pub-id-type="doi">10.1016/j.leukres.2013.05.018</pub-id><pub-id pub-id-type="pmid">23800797</pub-id></element-citation></ref>
<ref id="b24-ol-0-0-9663"><label>24</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Fujii</surname><given-names>T</given-names></name><name><surname>Tsuchiya</surname><given-names>T</given-names></name><name><surname>Yamada</surname><given-names>S</given-names></name><name><surname>Fujimoto</surname><given-names>K</given-names></name><name><surname>Suzuki</surname><given-names>T</given-names></name><name><surname>Kasahara</surname><given-names>T</given-names></name><name><surname>Kawashima</surname><given-names>K</given-names></name></person-group><article-title>Localization and synthesis of acetylcholine in human leukemic T cell lines</article-title><source>J Neurosci Res</source><volume>44</volume><fpage>66</fpage><lpage>72</lpage><year>1996</year><pub-id pub-id-type="doi">10.1002/(SICI)1097-4547(19960401)44:1&#x003C;66::AID-JNR9&#x003E;3.0.CO;2-G</pub-id><pub-id pub-id-type="pmid">8926632</pub-id></element-citation></ref>
<ref id="b25-ol-0-0-9663"><label>25</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Rubinstein</surname><given-names>H</given-names></name><name><surname>Lubrano</surname><given-names>T</given-names></name><name><surname>Dainko</surname><given-names>J</given-names></name><name><surname>Mathews</surname><given-names>H</given-names></name><name><surname>Lange</surname><given-names>C</given-names></name><name><surname>Silberman</surname><given-names>S</given-names></name><name><surname>Minowada</surname><given-names>J</given-names></name></person-group><article-title>Acetylcholinesterase in cultured human leukemia/lymphoma cell lines</article-title><source>Leuk Res</source><volume>8</volume><fpage>741</fpage><lpage>744</lpage><year>1984</year><pub-id pub-id-type="doi">10.1016/0145-2126(84)90023-7</pub-id><pub-id pub-id-type="pmid">6332244</pub-id></element-citation></ref>
<ref id="b26-ol-0-0-9663"><label>26</label><element-citation publication-type="journal"><person-group person-group-type="author"><name><surname>Alea</surname><given-names>MP</given-names></name><name><surname>Borroto-Escuela</surname><given-names>DO</given-names></name><name><surname>Romero-Fernandez</surname><given-names>W</given-names></name><name><surname>Fuxe</surname><given-names>K</given-names></name><name><surname>Garriga</surname><given-names>P</given-names></name></person-group><article-title>Differential expression of muscarinic acetylcholine receptor subtypes in Jurkat cells and their signaling</article-title><source>J Neuroimmunol</source><volume>237</volume><fpage>13</fpage><lpage>22</lpage><year>2011</year><pub-id pub-id-type="doi">10.1016/j.jneuroim.2011.05.010</pub-id><pub-id pub-id-type="pmid">21742386</pub-id></element-citation></ref>
</ref-list>
</back>
<floats-group>
<fig id="f1-ol-0-0-9663" position="float">
<label>Figure 1.</label>
<caption><p>Expression levels of &#x03B1;7-nAChR in patients with leukemia. (A) Representative immunoblots of &#x03B1;7-nAChR in the three main types of leukemia, including five subtypes of AML, two subtypes of ALL, and CML. GAPDH was used as the loading control. (B) The ratio of &#x03B1;7-nAChR to GAPDH was determined by densitometric analysis. Data are presented as the means &#x00B1; standard deviation. The number of cases in each group is presented in parentheses on the &#x00D7; axis. P&#x003C;0.05 was considered to indicate a statistically significant difference. &#x03B1;7-nAChR, nicotinic subtype &#x03B1;7 acetylcholine receptors; AML-M0, AML with minimal differentiation; AML-M1, AML without maturation; AML-M2, AML with maturation; APL, acute promyelocytic leukemia; AML-M4, acute myelomonocytic leukemia; CML, chronic myeloid leukemia; T-ALL, T lymphoblastic leukemia/lymphoma; B-ALL, B lymphoblastic leukemia/lymphoma.</p></caption>
<graphic xlink:href="ol-17-01-1357-g00.tif"/>
</fig>
<fig id="f2-ol-0-0-9663" position="float">
<label>Figure 2.</label>
<caption><p>Expression levels of M3-mAChR in patients with leukemia. (A) Representative immunoblots of M3-mAChR in the three main types of leukemia, including five subtypes of AML, two subtypes of ALL, and CML. (B) Ratio of M3-mAChR to GAPDH as determined by densitometric analysis. Data are presented as the means &#x00B1; standard deviation. The number of cases in each group is presented in parentheses at the &#x00D7; axis. P&#x003C;0.05 was considered to indicate a statistically significant difference. M3-mAChR, muscarinic subtype M3 acetylcholine receptors; AML-M0, AML with minimal differentiation; AML-M1, AML without maturation; AML-M2, AML with maturation; APL, acute promyelocytic leukemia; AML-M4, acute myelomonocytic leukemia; CML, chronic myeloid leukemia; T-ALL, T lymphoblastic leukemia/lymphoma; B-ALL, B lymphoblastic leukemia/lymphoma.</p></caption>
<graphic xlink:href="ol-17-01-1357-g01.tif"/>
</fig>
<table-wrap id="tI-ol-0-0-9663" position="float">
<label>Table I.</label>
<caption><p>Clinical characteristics of patients.</p></caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th align="left" valign="bottom">Disease diagnosis</th>
<th align="center" valign="bottom">No. of case</th>
<th align="center" valign="bottom">No. of males/females</th>
<th align="center" valign="bottom">Age (years)</th>
<th align="center" valign="bottom">Hemoglobin (g/dl)</th>
<th align="center" valign="bottom">Hematocrit (&#x0025;)</th>
<th align="center" valign="bottom">WBC count (&#x00D7;10<sup>9</sup>/l)</th>
<th align="center" valign="bottom">Platelet count (&#x00D7;10<sup>9</sup>/l)</th>
<th align="center" valign="bottom">Blast cells (&#x0025;)</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" valign="top">AML-M0</td>
<td align="center" valign="top">6</td>
<td align="center" valign="top">3/3</td>
<td align="center" valign="top">16&#x2013;76 (42)</td>
<td align="center" valign="top">6.2&#x2013;8.5 (8)</td>
<td align="center" valign="top">18.2&#x2013;25.5 (24.6)</td>
<td align="center" valign="top">2.4&#x2013;273.4 (62.1)</td>
<td align="center" valign="top">8&#x2013;133 (28)</td>
<td align="center" valign="top">80.5&#x2013;88 (85.8)</td>
</tr>
<tr>
<td align="left" valign="top">AML-M1</td>
<td align="center" valign="top">5</td>
<td align="center" valign="top">4/1</td>
<td align="center" valign="top">15&#x2013;81 (54)</td>
<td align="center" valign="top">6.9&#x2013;12.2 (8.8)</td>
<td align="center" valign="top">21.3&#x2013;37.0 (26.3)</td>
<td align="center" valign="top">4.8&#x2013;190.2 (16)</td>
<td align="center" valign="top">24&#x2013;507 (152)</td>
<td align="center" valign="top">24&#x2013;92.2 (39.8)</td>
</tr>
<tr>
<td align="left" valign="top">AML-M2</td>
<td align="center" valign="top">8</td>
<td align="center" valign="top">4/4</td>
<td align="center" valign="top">16&#x2013;66 (47.5)</td>
<td align="center" valign="top">4.2&#x2013;11.7 (8.1)</td>
<td align="center" valign="top">13.5&#x2013;33.8 (23.4)</td>
<td align="center" valign="top">0.5&#x2013;131 (20.6)</td>
<td align="center" valign="top">8&#x2013;85 (33)</td>
<td align="center" valign="top">65.7&#x2013;80.4 (76.6)</td>
</tr>
<tr>
<td align="left" valign="top">AML-M3</td>
<td align="center" valign="top">6</td>
<td align="center" valign="top">4/2</td>
<td align="center" valign="top">33&#x2013;85 (56.5)</td>
<td align="center" valign="top">7.3&#x2013;10 (7.95)</td>
<td align="center" valign="top">21&#x2013;29.8 (23)</td>
<td align="center" valign="top">0.6&#x2013;133.8 (13.9)</td>
<td align="center" valign="top">9&#x2013;113 (41)</td>
<td align="center" valign="top">64.5&#x2013;92.5 (82.3)</td>
</tr>
<tr>
<td align="left" valign="top">AML-M4</td>
<td align="center" valign="top">8</td>
<td align="center" valign="top">5/3</td>
<td align="center" valign="top">21&#x2013;71 (58.5)</td>
<td align="center" valign="top">4.9&#x2013;9.9 (8.4)</td>
<td align="center" valign="top">15.7&#x2013;30.5 (25.7)</td>
<td align="center" valign="top">9.2&#x2013;205.1 (31.4)</td>
<td align="center" valign="top">20&#x2013;189 (38.5)</td>
<td align="center" valign="top">66.3&#x2013;85 (78.8)</td>
</tr>
<tr>
<td align="left" valign="top">CML</td>
<td align="center" valign="top">5</td>
<td align="center" valign="top">3/2</td>
<td align="center" valign="top">26&#x2013;57 (49)</td>
<td align="center" valign="top">8.8&#x2013;12.3 (9.8)</td>
<td align="center" valign="top">26.4&#x2013;37.3 (32.1)</td>
<td align="center" valign="top">2.4&#x2013;312.4 (5.7)</td>
<td align="center" valign="top">100&#x2013;601 (209)</td>
<td align="center" valign="top">ND</td>
</tr>
<tr>
<td align="left" valign="top">T-ALL</td>
<td align="center" valign="top">9</td>
<td align="center" valign="top">8/1</td>
<td align="center" valign="top">19&#x2013;50 (26)</td>
<td align="center" valign="top">5&#x2013;16.6 (8.9)</td>
<td align="center" valign="top">16&#x2013;50.8 (26.9)</td>
<td align="center" valign="top">3.1&#x2013;280 (9.4)</td>
<td align="center" valign="top">17&#x2013;406 (131)</td>
<td align="center" valign="top">44.3&#x2013;90.4 (74.4)</td>
</tr>
<tr>
<td align="left" valign="top">B-ALL</td>
<td align="center" valign="top">4</td>
<td align="center" valign="top">2/2</td>
<td align="center" valign="top">15&#x2013;56 (29)</td>
<td align="center" valign="top">5.6&#x2013;12.5 (8.3)</td>
<td align="center" valign="top">18.8&#x2013;27.9 (25.8)</td>
<td align="center" valign="top">6.65&#x2013;153.1 (56.2)</td>
<td align="center" valign="top">21&#x2013;63 (31)</td>
<td align="center" valign="top">65.1&#x2013;77.7 (65.2)</td>
</tr>
<tr>
<td align="left" valign="top">Normal<sup><xref rid="tfn1-ol-0-0-9663" ref-type="table-fn">a</xref></sup></td>
<td align="center" valign="top">5</td>
<td align="center" valign="top">2/3</td>
<td align="center" valign="top">22&#x2013;34 (28)</td>
<td align="center" valign="top">12.1&#x2013;14.5 (13.3)</td>
<td align="center" valign="top">38.1&#x2013;44.1 (39.7)</td>
<td align="center" valign="top">4.55&#x2013;7.84 (5.7)</td>
<td align="center" valign="top">170&#x2013;341 (231)</td>
<td align="center" valign="top">ND</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="tfn1-ol-0-0-9663"><label>a</label><p>Normal is healthy subjects. Data in the parentheses are the median. AML, acute myeloid leukemia; M0, AML with minimal differentiation; M1, AML without maturation; M2, AML with maturation; M3, acute promyelocytic leukemia; M4, acute myelomonocytic leukemia; CML, chronic myeloid leukemia; T-ALL, T lymphoblastic leukemia/lymphoma; B-ALL, B lymphoblastic leukemia/lymphoma; ND, not determine.</p></fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="tII-ol-0-0-9663" position="float">
<label>Table II.</label>
<caption><p>Relative expression levels of &#x03B1;7-nAChR and M3-mAChR in patients with leukemia compare to healthy subjects.</p></caption>
<table frame="hsides" rules="groups">
<thead>
<tr>
<th/>
<th align="center" valign="bottom" colspan="4">Relative expression levels (&#x0025; of healthy subjects)</th>
</tr>
<tr>
<th/>
<th align="center" valign="bottom" colspan="4"><hr/></th>
</tr>
<tr>
<th/>
<th align="center" valign="bottom" colspan="2">&#x03B1;7-nAChR</th>
<th align="center" valign="bottom" colspan="2">M3-mAChR</th>
</tr>
<tr>
<th/>
<th align="center" valign="bottom" colspan="2"><hr/></th>
<th align="center" valign="bottom" colspan="2"><hr/></th>
</tr>
<tr>
<th align="left" valign="bottom">Leukemia types</th>
<th align="center" valign="bottom">Mean</th>
<th align="center" valign="bottom">Median</th>
<th align="center" valign="bottom">Mean</th>
<th align="center" valign="bottom">Median</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" valign="top">Normal<sup><xref rid="tfn2-ol-0-0-9663" ref-type="table-fn">a</xref></sup> (5)</td>
<td align="center" valign="top">100</td>
<td align="center" valign="top">100</td>
<td align="center" valign="top">100</td>
<td align="center" valign="top">100</td>
</tr>
<tr>
<td align="left" valign="top">AML-M0 (6)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;51</td>
<td align="center" valign="top">&#x00A0;&#x00A0;43</td>
<td align="center" valign="top">&#x00A0;&#x00A0;70</td>
<td align="center" valign="top">&#x00A0;&#x00A0;80</td>
</tr>
<tr>
<td align="left" valign="top">AML-M1 (5)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;79</td>
<td align="center" valign="top">&#x00A0;&#x00A0;75</td>
<td align="center" valign="top">129</td>
<td align="center" valign="top">147</td>
</tr>
<tr>
<td align="left" valign="top">AML-M2 (8)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;70</td>
<td align="center" valign="top">&#x00A0;&#x00A0;66</td>
<td align="center" valign="top">127</td>
<td align="center" valign="top">145</td>
</tr>
<tr>
<td align="left" valign="top">APL (6)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;57</td>
<td align="center" valign="top">&#x00A0;&#x00A0;54</td>
<td align="center" valign="top">&#x00A0;&#x00A0;47</td>
<td align="center" valign="top">&#x00A0;&#x00A0;57</td>
</tr>
<tr>
<td align="left" valign="top">AML-M4 (8)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;47</td>
<td align="center" valign="top">&#x00A0;&#x00A0;42</td>
<td align="center" valign="top">&#x00A0;&#x00A0;57</td>
<td align="center" valign="top">&#x00A0;&#x00A0;58</td>
</tr>
<tr>
<td align="left" valign="top">CML (5)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;49</td>
<td align="center" valign="top">&#x00A0;&#x00A0;48</td>
<td align="center" valign="top">164</td>
<td align="center" valign="top">187</td>
</tr>
<tr>
<td align="left" valign="top">T-ALL (9)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;26</td>
<td align="center" valign="top">&#x00A0;&#x00A0;19</td>
<td align="center" valign="top">&#x00A0;&#x00A0;40</td>
<td align="center" valign="top">&#x00A0;&#x00A0;49</td>
</tr>
<tr>
<td align="left" valign="top">B-ALL (4)</td>
<td align="center" valign="top">&#x00A0;&#x00A0;62</td>
<td align="center" valign="top">&#x00A0;&#x00A0;60</td>
<td align="center" valign="top">135</td>
<td align="center" valign="top">147</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn id="tfn2-ol-0-0-9663"><label>a</label><p>Normal is healthy subjects. Data in the parentheses are number of cases. Data are relative expression levels of &#x03B1;7-nAChR or M3-mAChR and presented as &#x0025; of mean or median of leukemic groups to mean or median of healthy subject group. AML, acute myeloid leukemia; M0, AML with minimal differentiation; M1, AML without maturation; M2, AML with maturation; M3, acute promyelocytic leukemia; M4, acute myelomonocytic leukemia; CML, chronic myeloid leukemia; T-ALL, T lymphoblastic leukemia/lymphoma; B-ALL, B lymphoblastic leukemia/lymphoma.</p></fn>
</table-wrap-foot>
</table-wrap>
</floats-group>
</article>
