MDM2 promotes the proliferation and inhibits the apoptosis of pituitary adenoma cells by directly interacting with p53
Abstract
Introduction: Pituitary adenomas constitute one of the most common intracranial tumours. The mouse double minute 2 homologue (MDM2) is considered as an important oncogene in many tumours, but it has been little studied in pituitary adenomas and the mechanism is not well understood. The purpose of this study was to investigate the function of MDM2 and its primary mechanism of action in pituitary adenoma cells.
Material and methods: The expression of MDM2 in pituitary adenoma cell lines and normal cells was determined by real-time polymerase chain reaction (RT-PCR). The proliferation and apoptosis of pituitary adenoma cells after inhibition of MDM2 expression were detected by MTS and flow cytometry, respectively. The protein expressions of MDM2 and p53 were detected by western blot. Co-IP was used to detect the direct binding between MDM2 and p53.
Results: The results of RT-PCR showed that MDM2 was significantly up-regulated in pituitary adenoma cell lines. Inhibition of MDM2 suppressed the proliferation and promoted apoptosis of pituitary adenoma cells. However, inhibiting the expression of MDM2 can promotethe protein expression of p53. The results of co-IP showed that MDM2 interacted with p53 by direct combination. Then, we inhibited the expressions of p53 and MDM2 simultaneously in the pituitary adenoma cells by co-transfecting siRNAs, and the results showed that, compared with the group that inhibited MDM2 alone, cell proliferation of the co-transfected group increased and apoptosis of the cotransfected group decreased, which was similar to the NC group.
Conclusions: Taken together, these results suggest that MDM2 promoted the proliferation and inhibited the apoptosis of pituitary adenoma cells by directly interacting with p53 in pituitary adenoma cells. Therefore, MDM2-p53 may serve as a novel marker and therapeutic target for pituitary adenomas.
Keywords: pituitary adenomasMDM2proliferationapoptosisp53
References
- Pichard C, Gerber S, Laloi M, et al. Pituitary carcinoma: report of an exceptional case and review of the literature. J Endocrinol Invest. 2002; 25(1): 65–72.
- Ezzat S, Asa SL, Couldwell WT, et al. The prevalence of pituitary adenomas: a systematic review. Cancer. 2004; 101(3): 613–619.
- Zhu X, Wang Y, Zhao X, et al. Incidence of Pituitary Apoplexy and Its Risk Factors in Chinese People: A Database Study of Patients with Pituitary Adenoma. PLoS One. 2015; 10(9): e0139088.
- Oliner JD, Kinzler KW, Meltzer PS, et al. Amplification of a gene encoding a p53-associated protein in human sarcomas. Nature. 1992; 358(6381): 80–83.
- Mairinger FD, Walter RFH, Ting S, et al. Mdm2 protein expression is strongly associated with survival in malignant pleural mesothelioma. Future Oncol. 2014; 10(6): 995–1005.
- Walter RFH, Mairinger FD, Ting S, et al. MDM2 is an important prognostic and predictive factor for platin-pemetrexed therapy in malignant pleural mesotheliomas and deregulation of P14/ARF (encoded by CDKN2A) seems to contribute to an MDM2-driven inactivation of P53. Br J Cancer. 2015; 112(5): 883–890.
- Lu X, Yan C, Huang Yi, et al. Mouse double minute 2 (MDM2) upregulates Snail expression and induces epithelial-to-mesenchymal transition in breast cancer cells in vitro and in vivo. Oncotarget. 2016; 7(24): 37177–37191.
- Gao C, Xiao Gu, Piersigilli A, et al. Context-dependent roles of MDMX (MDM4) and MDM2 in breast cancer proliferation and circulating tumor cells. Breast Cancer Res. 2019; 21(1): 5.
- Suliman M, Royds J, Cullen D, et al. Mdm2 and the p53 pathway in human pituitary adenomas. Clin Endocrinol (Oxf). 2001; 54(3): 317–325.
- Yao X, Gao H, Li C, et al. Analysis of Ki67, HMGA1, MDM2, and RB expression in nonfunctioning pituitary adenomas. J Neurooncol. 2017; 132(2): 199–206.
- Wu X, Bayle JH, Olson D, et al. The p53-mdm-2 autoregulatory feedback loop. Genes Dev. 1993; 7(7A): 1126–1132.
- Ye J, Liang R, Bai T, et al. RBM38 plays a tumor-suppressor role via stabilizing the p53-mdm2 loop function in hepatocellular carcinoma. J Exp Clin Cancer Res. 2018; 37(1): 212.
- Yi H, Yan X, Luo Q, et al. A novel small molecule inhibitor of MDM2-p53 (APG-115) enhances radiosensitivity of gastric adenocarcinoma. J Exp Clin Cancer Res. 2018; 37(1): 97.
- Fan X, Wang Y, Song J, et al. MDM2 inhibitor RG7388 potently inhibits tumors by activating p53 pathway in nasopharyngeal carcinoma. Cancer Biol Ther. 2019; 20(10): 1328–1336.
- Cahilly-Snyder L, Yang-Feng T, Francke U, et al. Molecular analysis and chromosomal mapping of amplified genes isolated from a transformed mouse 3T3 cell line. Somat Cell Mol Genet. 1987; 13(3): 235–244.
- Wade M, Li YC, Wahl GM. MDM2, MDMX and p53 in oncogenesis and cancer therapy. Nat Rev Cancer. 2013; 13(2): 83–96.
- Senturk E, Manfredi JJ. Mdm2 and tumorigenesis: evolving theories and unsolved mysteries. Genes Cancer. 2012; 3(3-4): 192–198.
- Olivier M, Hollstein M, Hainaut P. TP53 mutations in human cancers: origins, consequences, and clinical use. Cold Spring Harb Perspect Biol. 2010; 2(1): a001008.
- Piette J, Neel H, Maréchal V. Mdm2: keeping p53 under control. Oncogene. 1997; 15(9): 1001–1010.
- Zhao Y, Yu H, Hu W. The regulation of MDM2 oncogene and its impact on human cancers. Acta Biochim Biophys Sin (Shanghai). 2014; 46(3): 180–189.
- Hanahan D, Weinberg RA. Hallmarks of cancer: the next generation. Cell. 2011; 144(5): 646–674.
- Zhao Y, Aguilar A, Bernard D, et al. Small-molecule inhibitors of the MDM2-p53 protein-protein interaction (MDM2 Inhibitors) in clinical trials for cancer treatment. J Med Chem. 2015; 58(3): 1038–1052.
- Vassilev L. Small-Molecule Antagonists of p53-MDM2 Binding: Research Tools and Potential Therapeutics. Cell Cycle. 2014; 3(4): 417–419.
- Tovar C, Graves B, Packman K, et al. MDM2 small-molecule antagonist RG7112 activates p53 signaling and regresses human tumors in preclinical cancer models. Cancer Res. 2013; 73(8): 2587–2597.
- Bill KL, Garnett J, Meaux I, et al. SAR405838: A Novel and Potent Inhibitor of the MDM2:p53 Axis for the Treatment of Dedifferentiated Liposarcoma. Clin Cancer Res. 2016; 22(5): 1150–1160.
- Wagner AJ, Banerji U, Mahipal A, et al. Phase I Trial of the Human Double Minute 2 Inhibitor MK-8242 in Patients With Advanced Solid Tumors. J Clin Oncol. 2017; 35(12): 1304–1311.
- Holzer P, Masuya K, Furet P, et al. Discovery of a Dihydroisoquinolinone Derivative (NVP-CGM097): A Highly Potent and Selective MDM2 Inhibitor Undergoing Phase 1 Clinical Trials in p53wt Tumors. J Med Chem. 2015; 58(16): 6348–6358.
- Canon J, Osgood T, Olson SH, et al. The MDM2 Inhibitor AMG 232 Demonstrates Robust Antitumor Efficacy and Potentiates the Activity of p53-Inducing Cytotoxic Agents. Mol Cancer Ther. 2015; 14(3): 649–658.
