CagA increases DNA methylation and decreases PTEN expression in human gastric cancer

Zhang,Baogui; Zhang,Xiaobei; Jin,Meng; Hu,Lei; Zang,Mingde; Qiu,Weilong; Wang,Shouqi; Liu,Bingya; Liu,Shiqi; Guo,Dongli

doi:10.3892/mmr.2018.9654

CagA increases DNA methylation and decreases PTEN expression in human gastric cancer

Authors:
- Baogui Zhang
- Xiaobei Zhang
- Meng Jin
- Lei Hu
- Mingde Zang
- Weilong Qiu
- Shouqi Wang
- Bingya Liu
- Shiqi Liu
- Dongli Guo
View Affiliations

Affiliations: Department of Gastrointestinal Surgery, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China, Department of Central Laboratory, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China, Department of General Surgery Affiliated Provincial Hospital of Anhui Medical University, Hefei, Anhui 230001, P.R. China, Department of Gastric Cancer Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, P.R. China, Department of Surgery, Shanghai Key Laboratory of Gastric Neoplasms, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
Published online on: November 13, 2018 https://doi.org/10.3892/mmr.2018.9654
Pages: 309-319
Copyright: © Zhang et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Gastric cancer is one of the leading causes of cancer-associated mortality worldwide. Cytotoxin‑associated gene A (CagA) has been reported to be associated with gastric diseases. Phosphatase and tensin homolog (PTEN) and tet methylcytosine dioxygenase 1 (Tet1) are important tumor‑suppressor genes. The present study aimed to investigate the underlying functions of CagA in human gastric cancer, and to explore the associations between CagA, PTEN and Tet1 in gastric cancer. For that purpose, CagA overexpression and Tet1 interference recombinant lentiviral plasmids were constructed. Quantitative polymerase chain reaction (qPCR) was utilized to screen gene expression in HGC‑27 human gastric cancer cells overexpressing CagA. qPCR and western blotting were used to detect gene and protein expression, respectively. In addition, the methylation status of PTEN was detected by methylation‑specific PCR. The expression levels of PTEN, Tet1, apolipoprotein B mRNA editing enzyme catalytic subunit (APOBEC)3A, APOBEC3C and APOBEC3F were significantly decreased in the CagA overexpression group compared with in the negative control group in HGC‑27 cells. Compared with in the negative control group, the mRNA and protein expression levels of PTEN were markedly decreased in cells with Tet1 interference. The decreased expression of PTEN was associated with increased methylation levels in the cells. In addition, the protein expression levels of PTEN were significantly decreased in HGC‑27 cells when CagA was overexpressed. The expression levels of PTEN and Tet1 were also markedly decreased in CagA+ gastric cancer tissues compared with in non‑cancerous tissues. The decreased expression of PTEN in CagA+ gastric cancer tissues was associated with increased methylation levels. In conclusion, overexpression of CagA significantly decreased the expression of PTEN, Tet1, APOBEC3A, APOBEC3C and APOBEC3F in human gastric cancer. In addition, CagA increased DNA methylation and decreased PTEN expression, which was reversed by Tet1 overexpression. The present study may facilitate future therapeutic approaches targeting human gastric cancer.

View Figures

View References

1	Zhu AL and Sonnenberg A: Is gastric cancer again rising? J Clin Gastroenterol. 46:804–806. 2012. View Article : Google Scholar : PubMed/NCBI
2	Correa P: Gastric cancer: Two epidemics? Dig Dis Sci. 56:1585–1586; author reply, 1586. 2011. View Article : Google Scholar : PubMed/NCBI
3	Jeyamani L, Jayarajan J, Leelakrishnan V and Swaminathan M: CagA and VacA genes of Helicobacter pylori and their clinical relevance. Indian J Pathol Microbiol. 61:66–69. 2018. View Article : Google Scholar : PubMed/NCBI
4	Weel JF, van der Hulst RW, Gerrits Y, Roorda P, Feller M, Dankert J, Tytgat GN and van der Ende A: The interrelationship between cytotoxin-associated gene A, vacuolating cytotoxin, and Helicobacter pylori-related diseases. J Infect Dis. 173:1171–1175. 1996. View Article : Google Scholar : PubMed/NCBI
5	Huang JQ, Zheng GF, Sumanac K, Irvine EJ and Hunt RH: Meta-analysis of the relationship between cagA seropositivity and gastric cancer. Gastroenterology. 125:1636–1644. 2003. View Article : Google Scholar : PubMed/NCBI
6	Franco AT, Israel DA, Washington MK, Krishna U, Fox JG, Rogers AB, Neish AS, Collier-Hyams L, Perez-Perez GI, Hatakeyama M, et al: Activation of beta-catenin by carcinogenic Helicobacter pylori. Proc Natl Acad Sci USA. 102:10646–10651. 2005. View Article : Google Scholar : PubMed/NCBI
7	Basso D, Zambon CF, Letley DP, Stranges A, Marchet A, Rhead JL, Schiavon S, Guariso G, Ceroti M, Nitti D, et al: Clinical relevance of Helicobacter pylori cagA and vacA gene polymorphisms. Gastroenterology. 135:91–99. 2008. View Article : Google Scholar : PubMed/NCBI
8	Keniry M and Parsons R: The role of PTEN signaling perturbations in cancer and in targeted therapy. Oncogene. 27:5477–5485. 2008. View Article : Google Scholar : PubMed/NCBI
9	Krymskaya VP and Goncharova EA: PI3K/mTORC1 activation in hamartoma syndromes: Therapeutic prospects. Cell Cycle. 8:403–413. 2009. View Article : Google Scholar : PubMed/NCBI
10	Sansal I and Sellers WR: The biology and clinical relevance of the PTEN tumor suppressor pathway. J Clin Oncol. 22:2954–2963. 2004. View Article : Google Scholar : PubMed/NCBI
11	Stambolic V, Suzuki A, de la Pompa JL, Brothers GM, Mirtsos C, Sasaki T, Ruland J, Penninger JM, Siderovski DP and Mak TW: Negative regulation of PKB/Akt-dependent cell survival by the tumor suppressor PTEN. Cell. 95:29–39. 1998. View Article : Google Scholar : PubMed/NCBI
12	Fu HL, Ma Y, Lu LG, Hou P, Li BJ, Jin WL and Cui DX: TET1 exerts its tumor suppressor function by interacting with p53-EZH2 pathway in gastric cancer. J Biomed Nanotechnol. 10:1217–1230. 2014. View Article : Google Scholar : PubMed/NCBI
13	Pastor WA, Aravind L and Rao A: TETonic shift: Biological roles of TET proteins in DNA demethylation and transcription. Nat Rev Mol Cell Biol. 14:341–356. 2013. View Article : Google Scholar : PubMed/NCBI
14	Livak KJ and Schmittgen TD: Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) method. Methods. 25:402–408. 2001. View Article : Google Scholar : PubMed/NCBI
15	Blaser MJ, Perez-Perez GI, Kleanthous H, Cover TL, Peek RM, Chyou PH, Stemmermann GN and Nomura A: Infection with Helicobacter pylori strains possessing cagA is associated with an increased risk of developing adenocarcinoma of the stomach. Cancer Res. 55:2111–2115. 1995.PubMed/NCBI
16	Miehlke S, Kirsch C, Agha-Amiri K, Günther T, Lehn N, Malfertheiner P, Stolte M, Ehninger G and Bayerdörffer E: The Helicobacter pylori vacA s1, m1 genotype and cagA is associated with gastric carcinoma in Germany. Int J Cancer. 87:322–327. 2000. View Article : Google Scholar : PubMed/NCBI
17	Plummer M, van Doorn LJ, Franceschi S, Kleter B, Canzian F, Vivas J, Lopez G, Colin D, Muñoz N and Kato I: Helicobacter pylori cytotoxin-associated genotype and gastric precancerous lesions. J Natl Cancer Inst. 99:1328–1334. 2007. View Article : Google Scholar : PubMed/NCBI
18	Loh JT, Shaffer CL, Piazuelo MB, Bravo LE, McClain MS, Correa P and Cover TL: Analysis of cagA in Helicobacter pylori strains from Colombian populations with contrasting gastric cancer risk reveals a biomarker for disease severity. Cancer Epidemiol Biomarkers Prev. 20:2237–2249. 2011. View Article : Google Scholar : PubMed/NCBI
19	Churin Y, Al-Ghoul L, Kepp O, Meyer TF, Birchmeier W and Naumann M: Helicobacter pylori CagA protein targets the c-Met receptor and enhances the motogenic response. J Cell Biol. 161:249–255. 2003. View Article : Google Scholar : PubMed/NCBI
20	Faller G and Kirchner T: Immunological and morphogenic basis of gastric mucosa atrophy and metaplasia. Virchows Arch. 446:1–9. 2005. View Article : Google Scholar : PubMed/NCBI
21	Hlubek F, Spaderna S, Schmalhofer O, Jung A, Kirchner T and Brabletz T: Wnt/FZD signaling and colorectal cancer morphogenesis. Front Biosci. 12:458–470. 2007. View Article : Google Scholar : PubMed/NCBI
22	Bagnoli F, Buti L, Tompkins L, Covacci A and Amieva MR: Helicobacter pylori CagA induces a transition from polarized to invasive phenotypes in MDCK cells. Proc Natl Acad Sci USA. 102:16339–16344. 2005. View Article : Google Scholar : PubMed/NCBI
23	Weydig C, Starzinski-Powitz A, Carra G, Löwer J and Wessler S: CagA-independent disruption of adherence junction complexes involves E-cadherin shedding and implies multiple steps in Helicobacter pylori pathogenicity. Exp Cell Res. 313:3459–3471. 2007. View Article : Google Scholar : PubMed/NCBI
24	Murata-Kamiya N, Kurashima Y, Teishikata Y, Yamahashi Y, Saito Y, Higashi H, Aburatani H, Akiyama T, Peek RM Jr, Azuma T and Hatakeyama M: Helicobacter pylori CagA interacts with E-cadherin and deregulates the beta-catenin signal that promotes intestinal transdifferentiation in gastric epithelial cells. Oncogene. 26:4617–4626. 2007. View Article : Google Scholar : PubMed/NCBI
25	Pei YF, Tao R, Li JF, Su LP, Yu BQ, Wu XY, Yan M, Gu QL, Zhu ZG and Liu BY: TET1 inhibits gastric cancer growth and metastasis by PTEN demethylation and re-expression. Oncotarget. 7:31322–31335. 2016. View Article : Google Scholar : PubMed/NCBI
26	Chen S, Li X, Qin J, Chen Y, Liu L and Zhang D, Wang M, Wang M and Zhang D: APOBEC3A possesses anticancer and antiviral effects by differential inhibition of HPV E6 and E7 expression on cervical cancer. Int J Clin Exp Med. 8:10548–10557. 2015.PubMed/NCBI
27	Gansmo LB, Romundstad P, Hveem K, Vatten L, Nik-Zainal S, Lønning PE and Knappskog S: APOBEC3A/B deletion polymorphism and cancer risk. Carcinogenesis. 39:118–124. 2017. View Article : Google Scholar :
28	Yu Q, Chen D, König R, Mariani R, Unutmaz D and Landau NR: APOBEC3B and APOBEC3C are potent inhibitors of simian immunodeficiency virus replication. J Biol Chem. 279:53379–53386. 2004. View Article : Google Scholar : PubMed/NCBI
29	Ara A, Love RP, Follack TB, Ahmed KA, Adolph MB and Chelico L: Mechanism of enhanced HIV restriction by virion coencapsidated cytidine deaminases APOBEC3F and APOBEC3G. J Virol. 91:e02230–16. 2016.