Osteopontin-c mediates the upregulation of androgen responsive genes in LNCaP cells through PI3K/Akt and androgen receptor signaling

Tilli,Tatiana   Martins; Ferreira,Luciana   Bueno; Gimba,Etel  Rodrigues Pereira

doi:10.3892/ol.2015.2939

Osteopontin-c mediates the upregulation of androgen responsive genes in LNCaP cells through PI3K/Akt and androgen receptor signaling

Authors:
- Tatiana Martins Tilli
- Luciana Bueno Ferreira
- Etel Rodrigues Pereira Gimba
View Affiliations

Affiliations: Molecular Carcinogenesis Program, Research Coordination, National Institute of Cancer, Rio de Janeiro 22743-051, Brazil, Institute of Molecular Pathology and Immunology, University of Porto, Porto 4200-465, Portugal
Published online on: February 6, 2015 https://doi.org/10.3892/ol.2015.2939
Pages: 1845-1850

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

Androgen receptor (AR) signaling is a key pathway modulating prostate cancer (PCa) progression. Several steps in this pathway have been investigated in order to propose novel treatment strategies for advanced PCa. Total osteopontin (OPN) has been described as a biomarker for PCa, in addition to its role in activating the progression of this tumor. Based on the known effects of the OPNc splice variant on PCa progression, the present study investigated whether this isoform can also modulate AR signaling. In order to test this, an in vitro model was used in which LNCaP cells were cultured in the presence of conditioned medium (CM) secreted by PCa cells overexpressing OPNc (OPNc‑CM). The activation of AR signaling was evaluated by measuring the expression levels of AR‑responsive genes (ARGs) using quantitative polymerase chain reaction and specific oligonucleotides. The data demonstrated that all nine tested ARGs (Fgf8, TMPRSS2, Greb1, Cdk2, Ndrg1, Cdk1, Pmepa1, Psa and Ar) are significantly upregulated in response to OPNc‑CM compared with LNCaP cells cultured in CM secreted by control cells transfected with empty expression vector. The specific involvement of OPNc was demonstrated by depleting OPNc from OPNc‑CM using an anti‑OPNc neutralizing antibody. In addition, by using a phosphoinositide 3-kinase (PI3K)‑specific inhibitor and AR antagonists, such as flutamide and bicalutamide, it was also observed that upregulation of ARGs in response to OPNc‑CM involves PI3K signaling and depends on the AR. In conclusion, these data indicated that OPNc is able to activate AR signaling through the PI3K pathway and the AR. These data further corroborate our previous data, revealing the OPNc splice variant to be a key molecule that is able to modulate key signaling pathways involved in PCa progression.

View Figures

View References

1	Bellahcène A, Castronovo V, Ogbureke KU, Fisher LW and Fedarko NS: Small integrin-binding ligand N-linked glycoproteins (SIBLINGs): multifunctional proteins in cancer. Nat Rev Cancer. 8:212–226. 2008. View Article : Google Scholar : PubMed/NCBI
2	Zhang Y, Forootan SS, Kamalian L, et al: Suppressing tumourigenicity of prostate cancer cells by inhibiting osteopontin expression. Int J Oncol. 38:1083–1091. 2011.PubMed/NCBI
3	Zheng J, Hou ZB and Jiao NL: Effects of osteopontin downregulation on the growth of prostate cancer PC-3 cells. Mol Med Rep. 4:1225–1231. 2011.PubMed/NCBI
4	He B, Mirza M and Weber GF: An osteopontin splice variant induces anchorage independence in human breast cancer cells. Oncogene. 25:2192–2202. 2006. View Article : Google Scholar
5	Gimba ER and Tilli TM: Human osteopontin splicing isoforms: known roles, potential clinical applications and activated signaling pathways. Cancer Lett. 331:11–17. 2013. View Article : Google Scholar
6	Puzone R, Paleari L, Montefiore F, et al: Osteopontin plasma level does not detect prostate cancer in patients referred for diagnostic prostate biopsy. Int J Biol Markers. 25:200–206. 2010.PubMed/NCBI
7	Thoms JW, Dal Pra A, Anborgh PH, et al: Plasma osteopontin as a biomarker of prostate cancer aggression: relationship to risk category and treatment response. Br J Cancer. 107:840–846. 2012. View Article : Google Scholar : PubMed/NCBI
8	Weber GF, Lett GS and Haubein NC: Osteopontin is a marker for cancer aggressiveness and patient survival. Br J Cancer. 103:861–869. 2010. View Article : Google Scholar : PubMed/NCBI
9	Weber GF, Lett GS and Haubein NC: Categorical meta-analysis of Osteopontin as a clinical cancer marker. Oncol Rep. 25:433–441. 2011. View Article : Google Scholar
10	Tilli TM, Mello KD, Ferreira LB, et al: Both osteopontin-c and osteopontin-b splicing isoforms exert pro-tumorigenic roles in prostate cancer cells. Prostate. 72:1688–1699. 2012. View Article : Google Scholar : PubMed/NCBI
11	Tilli TM, Thuler LC, Matos AR, et al: Expression analysis of osteopontin mRNA splice variants in prostate cancer and benign prostatic hyperplasia. Exp Mol Pathol. 92:13–19. 2012. View Article : Google Scholar
12	Martinez HD, Hsiao JJ, Jasavala RJ, Hinkson IV, Eng JK and Wright ME: Androgen-sensitive microsomal signaling networks coupled to the proliferation and differentiation of human prostate cancer cells. Genes Cancer. 2:956–978. 2011. View Article : Google Scholar
13	Takayama K, Tsutsumi S, Katayama S, et al: Integration of cap analysis of gene expression and chromatin immunoprecipitation analysis on array reveals genome-wide androgen receptor signaling in prostate cancer cells. Oncogene. 30:619–630. 2011. View Article : Google Scholar
14	Liu X, Choi RY, Jawad SM and Arnold JT: Androgen-induced PSA expression requires not only activation of AR but also endogenous IGF-I or IGF-I/PI3K/Akt signaling in human prostate cancer epithelial cells. Prostate. 71:766–777. 2011. View Article : Google Scholar :
15	Bitting RL and Armstrong AJ: Targeting the PI3K/Akt/mTOR pathway in castration-resistant prostate cancer. Endocr Relat Cancer. 20:R83–R99. 2013. View Article : Google Scholar : PubMed/NCBI
16	Terracciano D, Mazzarella C, Di Carlo A, et al: Effects of the ErbB1/ErbB2 kinase inhibitor GW2974 on androgen-independent prostate cancer PC-3 cell line growth and NSE, chromogranin A and osteopontin content. Oncol Rep. 24:213–217. 2010.PubMed/NCBI
17	Zhu H and Garcia JA: Targeting the adrenal gland in castration-resistant prostate cancer: a case for orteronel, a selective CYP-17 17,20-lyase inhibitor. Curr Oncol Rep. 15:105–112. 2013. View Article : Google Scholar : PubMed/NCBI
18	Elo TD, Valve EM, Seppänen JA, et al: Stromal activation associated with development of prostate cancer in prostate-targeted fibroblast growth factor 8b transgenic mice. Neoplasia. 12:915–927. 2010.PubMed/NCBI
19	Angelucci A, Festuccia C, Gravina GL, et al: Osteopontin enhances the cell proliferation induced by the epidermal growth factor in human prostate cancer cells. Prostate. 59:157–166. 2004. View Article : Google Scholar : PubMed/NCBI
20	Tilli TM, Bellahcène A, Castronovo V and Gimba ER: Changes in the transcriptional profile in response to overexpression of the osteopontin-c splice isoform in ovarian (OvCar-3) and prostate (PC-3) cancer cell lines. BMC Cancer. 14:4332014. View Article : Google Scholar : PubMed/NCBI
21	Ngan S, Stronach EA, Photiou A, Waxman J, Ali S and Buluwela L: Microarray coupled to quantitative RT-PCR analysis of androgen-regulated genes in human LNCaP prostate cancer cells. Oncogene. 28:2051–2063. 2009. View Article : Google Scholar : PubMed/NCBI
22	Mattila MM and Härkönen PL: Role of fibroblast growth factor 8 in growth and progression of hormonal cancer. Cytokine Growth Factor Rev. 18:257–266. 2007. View Article : Google Scholar : PubMed/NCBI
23	Ferreira LB, Palumbo A, de Mello KD, et al: PCA3 noncoding RNA is involved in the control of prostate-cancer cell survival and modulates androgen receptor signaling. BMC Cancer. 12:5072012. View Article : Google Scholar : PubMed/NCBI
24	Flores O, Wang Z, Knudsen KE and Burnstein KL: Nuclear targeting of cyclin-dependent kinase 2 reveals essential roles of cyclin-dependent kinase 2 localization and cyclin E in vitamin D-mediated growth inhibition. Endocrinology. 151:896–908. 2010. View Article : Google Scholar : PubMed/NCBI
25	Rae JM, Johnson MD, Cordero KE, et al: GREB1 is a novel androgen-regulated gene required for prostate cancer growth. Prostate. 66:886–894. 2006. View Article : Google Scholar : PubMed/NCBI
26	Lilja H: Biology of prostate-specific antigen. Urology. 62(Suppl 1): 27–33. 2003. View Article : Google Scholar : PubMed/NCBI
27	Chen YW, Lee MS, Lucht A, et al: TMPRSS2, a serine protease expressed in the prostate on the apical surface of luminal epithelial cells and released into semen in prostasomes, is misregulated in prostate cancer cells. Am J Pathol. 176:2986–2996. 2010. View Article : Google Scholar : PubMed/NCBI
28	Tomlins SA, Laxman B, Varambally S, et al: Role of the TMPRSS2-ERG gene fusion in prostate cancer. Neoplasia. 10:177–188. 2008. View Article : Google Scholar : PubMed/NCBI
29	Li H, Xu LL, Masuda K, et al: A feedback loop between the androgen receptor and a NEDD4-binding protein, PMEPA1, in prostate cancer cells. J Biol Chem. 283:28988–28995. 2008. View Article : Google Scholar : PubMed/NCBI
30	Richter E, Masuda K, Cook C, et al: A role for DNA methylation in regulating the growth suppressor PMEPA1 gene in prostate cancer. Epigenetics. 2:100–109. 2007. View Article : Google Scholar
31	Mattsson JM, Laakkonen P, Stenman UH and Koistinen H: Antiangiogenic properties of prostate-specific antigen (PSA). Scand J Clin Lab Invest. 69:447–451. 2009. View Article : Google Scholar : PubMed/NCBI
32	Guo Y, Pili R and Passaniti A: Regulation of prostate-specific antigen gene expression in LNCaP human prostatic carcinoma cells by growth, dihydrotestosterone, and extracellular matrix. Prostate. 24:1–10. 1994. View Article : Google Scholar : PubMed/NCBI
33	Sica G, Iacopino F, Settesoldi D and Zelano G: Effect of leuprorelin acetate on cell growth and prostate-specific antigen gene expression in human prostatic cancer cells. Eur Urol. 35(Suppl 1): 2–8. 1999. View Article : Google Scholar : PubMed/NCBI
34	Valdez CD, Davis JN, Odeh HM, et al: Repression of androgen receptor transcription through the E2F1/DNMT1 axis. PloS One. 6:e251872011. View Article : Google Scholar : PubMed/NCBI
35	Shiota M, Yokomizo A and Naito S: Increased androgen receptor transcription: a cause of castration-resistant prostate cancer and a possible therapeutic target. J Mol Endocrinol. 47:R25–R41. 2011. View Article : Google Scholar : PubMed/NCBI
36	Hou X, Li Z, Huang W, et al: Plk1-dependent microtubule dynamics promotes androgen receptor signaling in prostate cancer. Prostate. 73:1352–1363. 2013. View Article : Google Scholar : PubMed/NCBI
37	Baena E, Shao Z, Linn DE, et al: ETV1 directs androgen metabolism and confers aggressive prostate cancer in targeted mice and patients. Genes Dev. 27:683–698. 2013. View Article : Google Scholar : PubMed/NCBI
38	Patki M, Chari V, Sivakumaran S, Gonit M, Trumbly R and Ratnam M: The ETS domain transcription factor ELK1 directs a critical component of growth signaling by the androgen receptor in prostate cancer cells. J Biol Chem. 288:11047–11065. 2013. View Article : Google Scholar : PubMed/NCBI
39	Chun JY, Nadiminty N, Dutt S, et al: Interleukin-6 regulates androgen synthesis in prostate cancer cells. Clin Cancer Res. 15:4815–4822. 2009. View Article : Google Scholar : PubMed/NCBI