Abstract
Deregulation of the PI3K-AKT/mTOR pathway due to mutation of the tumor suppressor gene PTEN frequently occurs in human prostate cancer and is therefore considered to be an attractive therapeutic target. Here, we investigated how the PTEN genotype affected the antitumor effect of NVP-BEZ235 in human prostate cancer cells. In this setting, NVP-BEZ235 induced cell death in a PTEN-independent manner. NVP-BEZ235 selectively induced apoptotic cell death in the prostate cancer cell line DU145, which harbors wild-type PTEN; however, in the PC3 cell line, which is PTEN-null, treatment with NVP-BEZ235 resulted in autophagic cell death. Consistently, NVP-BEZ235 treatment did not result in the cleavage of caspase-3; instead, it resulted in the conversion of LC3-I to LC3-II, indicating autophagic cell death; these results suggest that an alternate mechanism of cell death is induced by NVP-BEZ235 in PTEN-null prostate cancer cells. Based on our findings, we conclude that the PTEN/PI3K/Akt pathway is critical for prostate cancer survival, and targeting PI3K signaling by NVP-BEZ235 may be beneficial in the treatment of prostate cancer, independent of the PTEN genotype.
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References
Manning BD, Cantley LC (2007) AKT/PKB signaling: navigating downstream. Cell 129(7):1261–1274. doi:10.1016/j.cell.2007.06.009
Campbell IG, Russell SE, Choong DY, Montgomery KG, Ciavarella ML, Hooi CS et al (2004) Mutation of the PIK3CA gene in ovarian and breast cancer. Cancer Res 64(21):7678–7681. doi:10.1158/0008-5472.CAN-04-2933
Samuels Y, Wang Z, Bardelli A, Silliman N, Ptak J, Szabo S et al (2004) High frequency of mutations of the PIK3CA gene in human cancers. Science 304(5670):554. doi:10.1126/science.10965021096502
Philp AJ, Campbell IG, Leet C, Vincan E, Rockman SP, Whitehead RH et al (2001) The phosphatidylinositol 3′-kinase p85alpha gene is an oncogene in human ovarian and colon tumors. Cancer Res 61(20):7426–7429
Brachmann SM, Hofmann I, Schnell C, Fritsch C, Wee S, Lane H et al (2009) Specific apoptosis induction by the dual PI3K/mTor inhibitor NVP-BEZ235 in HER2 amplified and PIK3CA mutant breast cancer cells. Proc Natl Acad Sci U S A 106(52):22299–22304. doi:10.1073/pnas.0905152106
Liaw D, Marsh DJ, Li J, Dahia PL, Wang SI, Zheng Z et al (1997) Germline mutations of the PTEN gene in Cowden disease, an inherited breast and thyroid cancer syndrome. Nat Genet 16(1):64–67. doi:10.1038/ng0597-64
Engelman JA, Luo J, Cantley LC (2006) The evolution of phosphatidylinositol 3-kinases as regulators of growth and metabolism. Nat Rev Genet 7(8):606–619. doi:10.1038/nrg1879
Chalhoub N, Baker SJ (2009) PTEN and the PI3-kinase pathway in cancer. Annu Rev Pathol 4:127–150. doi:10.1146/annurev.pathol.4.110807.092311
Cairns P, Okami K, Halachmi S, Halachmi N, Esteller M, Herman JG et al (1997) Frequent inactivation of PTEN/MMAC1 in primary prostate cancer. Cancer Res 57(22):4997–5000
Dong JT, Sipe TW, Hyytinen ER, Li CL, Heise C, McClintock DE et al (1998) PTEN/MMAC1 is infrequently mutated in pT2 and pT3 carcinomas of the prostate. Oncogene 17(15):1979–1982. doi:10.1038/sj.onc.1202119
Verhagen PC, van Duijn PW, Hermans KG, Looijenga LH, van Gurp RJ, Stoop H et al (2006) The PTEN gene in locally progressive prostate cancer is preferentially inactivated by bi-allelic gene deletion. J Pathol 208(5):699–707. doi:10.1002/path.1929
Sarker D, Reid AH, Yap TA, de Bono JS (2009) Targeting the PI3K/AKT pathway for the treatment of prostate cancer. Clin Cancer Res 15(15):4799–4805. doi:10.1158/1078-0432.CCR-08-0125
Yoshimoto M, Bayani J, Nuin PA, Silva NS, Cavalheiro S, Stavale JN et al (2006) Metaphase and array comparative genomic hybridization: unique copy number changes and gene amplification of medulloblastomas in South America. Cancer Genet Cytogenet 170(1):40–47. doi:10.1016/j.cancergencyto.2006.05.009
Halvorsen OJ, Haukaas SA, Akslen LA (2003) Combined loss of PTEN and p27 expression is associated with tumor cell proliferation by Ki-67 and increased risk of recurrent disease in localized prostate cancer. Clin Cancer Res 9(4):1474–1479
Maira SM, Stauffer F, Brueggen J, Furet P, Schnell C, Fritsch C et al (2008) Identification and characterization of NVP-BEZ235, a new orally available dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor with potent in vivo antitumor activity. Mol Cancer Ther 7(7):1851–1863. doi:10.1158/1535-7163.MCT-08-0017
Santiskulvong C, Konecny GE, Fekete M, Chen KY, Karam A, Mulholland D et al (2011) Dual targeting of phosphoinositide 3-kinase and mammalian target of rapamycin using NVP-BEZ235 as a novel therapeutic approach in human ovarian carcinoma. Clin Cancer Res 17(8):2373–2384. doi:10.1158/1078-0432.CCR-10-2289
Liu TJ, Koul D, LaFortune T, Tiao N, Shen RJ, Maira SM et al (2009) NVP-BEZ235, a novel dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor, elicits multifaceted antitumor activities in human gliomas. Mol Cancer Ther 8(8):2204–2210. doi:10.1158/1535-7163.MCT-09-0160
Kabeya Y, Mizushima N, Ueno T, Yamamoto A, Kirisako T, Noda T et al (2000) LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing. EMBO J 19(21):5720–5728. doi:10.1093/emboj/19.21.5720
Hendil KB, Lauridsen AM, Seglen PO (1990) Both endocytic and endogenous protein degradation in fibroblasts is stimulated by serum/amino acid deprivation and inhibited by 3-methyladenine. Biochem J 272(3):577–581
Dubrovska A, Kim S, Salamone RJ, Walker JR, Maira SM, Garcia-Echeverria C et al (2009) The role of PTEN/Akt/PI3K signaling in the maintenance and viability of prostate cancer stem-like cell populations. Proc Natl Acad Sci U S A 106(1):268–273. doi:10.1073/pnas.0810956106
Jin N, Jiang T, Rosen DM, Nelkin BD, Ball DW (2011) Synergistic action of a RAF inhibitor and a dual PI3K/mTOR inhibitor in thyroid cancer. Clin Cancer Res 17(20):6482–6489. doi:10.1158/1078-0432.CCR-11-0933
Shoji K, Oda K, Kashiyama T, Ikeda Y, Nakagawa S, Sone K et al (2012) Genotype-dependent efficacy of a dual PI3K/mTOR inhibitor, NVP-BEZ235, and an mTOR inhibitor, RAD001, in endometrial carcinomas. PLoS One 7(5):e37431. doi:10.1371/journal.pone.0037431PONE-D-12-01860
Yang S, Xiao X, Meng X, Leslie KK (2011) A mechanism for synergy with combined mTOR and PI3 kinase inhibitors. PLoS One 6(10):e26343. doi:10.1371/journal.pone.0026343PONE-D-11-10214
Bitting RL, Armstrong AJ (2013) Targeting the PI3K/Akt/mTOR pathway in castration-resistant prostate cancer. Endocr Relat Cancer 20(3):R83–R99. doi:10.1530/ERC-12-0394ERC-12-0394
Downward J (1998) Mechanisms and consequences of activation of protein kinase B/Akt. Curr Opin Cell Biol 10(2):262–267.
Degtyarev M, De Maziere A, Orr C, Lin J, Lee BB, Tien JY et al (2008) Akt inhibition promotes autophagy and sensitizes PTEN-null tumors to lysosomotropic agents. J Cell Biol 183(1):101–116. doi:10.1083/jcb.200801099
Klionsky DJ, Abeliovich H, Agostinis P, Agrawal DK, Aliev G, Askew DS et al (2008) Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy 4(2):151–175.
Acknowledgments
This study was supported by grants from the Korea Health 21 R&D Project, Ministry of Health and Welfare and Family Affairs (HI10C2014), the Converging Research Center Program of the Ministry of Education, Science and Technology (2011K000871), and the Basic Science Research program through the National Research Foundation of Korea (NRF), which was funded by the Ministry of Education, Science and Technology (2012R1A1A2009160), Republic of Korea. This study was supported by a grant (2011-506) from the Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea. We would like to thank Dr. Jaeyoung Koh, Department of Neurology, Asan Medical Center, for providing the GFP-LC3 cDNA.
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Seung-Woo Hong, Jae-Sik Shin, Jai-Hee Moon have contributed equally to this work.
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Hong, SW., Shin, JS., Moon, JH. et al. NVP-BEZ235, a dual PI3K/mTOR inhibitor, induces cell death through alternate routes in prostate cancer cells depending on the PTEN genotype. Apoptosis 19, 895–904 (2014). https://doi.org/10.1007/s10495-014-0973-4
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DOI: https://doi.org/10.1007/s10495-014-0973-4