MiR-183-5p-PNPT1 Axis Enhances Cisplatin-induced Apoptosis in Bladder Cancer Cells

Abstract

Objective

It has been reported that intrinsic apoptosis is associated with the progression of bladder cancer (BC). Recent evidence suggests that polyribonucleotide nucleotidyltransferase 1 (PNPT1) is a pivotal mediator involved in RNA decay and cell apoptosis. However, the regulation and roles of PNPT1 in bladder cancer remain largely unclear.

Methods

The upstream miRNA regulators were predicted by in silico analysis. The expression levels of PNPT1 were evaluated by real-time PCR, Western blotting, and immunohistochemistry (IHC), while miR-183-5p levels were evaluated by qPCR in BC cell lines and tissues. In vitro and in vivo assays were performed to investigate the function of miR-183-5p and PNPT1 in apoptotic RNA decay and the tumorigenic capability of bladder cancer cells.

Results

PNPT1 expression was decreased in BC tissues and cell lines. Overexpression of PNPT1 significantly promoted cisplatin-induced intrinsic apoptosis of BC cells, whereas depletion of PNPT1 potently alleviated these effects. Moreover, oncogenic miR-183-5p directly targeted the 3′ UTR of PNPT1 and reversed the tumor suppressive role of PNPT1. Intriguingly, miR-183-5p modulated not only PNPT1 but also Bcl2 modifying factor (BMF) to inhibit the mitochondrial outer membrane permeabilization (MOMP) in BC cells.

Conclusion

Our results provide new insight into the mechanisms underlying intrinsic apoptosis in BC, suggesting that the miR-183-5p-PNPT1 regulatory axis regulates the apoptosis of BC cells and might represent a potential therapeutic avenue for the treatment of BC.

Keywords

bladder cancer / polyribonucleotide nucleotidyltransferase 1 / bcl2 modifying factor / mitochondrial outer membrane permeabilization / microRNA

References

[1] AntoniS, FerlayJ, SoerjomataramI, et al.. Bladder Cancer Incidence and Mortality: A Global Overview and Recent Trends. Eur Urol, 2017, 71(1): 96-108

[2] AbufarajM, DalbagniG, DaneshmandS, et al.. The Role of Surgery in Metastatic Bladder Cancer: A Systematic Review. Eur Urol, 2018, 73(4): 543-557

[3] Alfred WitjesJ, LebretT, CompératEM, et al.. Updated 2016 EAU Guidelines on Muscle-invasive and Metastatic Bladder Cancer. Eur Urol, 2017, 71(3): 462-475

[4] von der MaaseH, SengelovL, RobertsJT, et al.. Long-term survival results of a randomized trial comparing gemcitabine plus cisplatin, with methotrexate, vinblastine, doxorubicin, plus cisplatin in patients with bladder cancer. J Clin Oncol, 2005, 23(21): 4602-4608

[5] BartelDP. MicroRNAs: Target recognition and regulatory functions. Cell, 2009, 136(2): 215-233

[6] BertoliG, CavaC, CastiglioniI. MicroRNAs: New Biomarkers for Diagnosis, Prognosis, Therapy Prediction and Therapeutic Tools for Breast Cancer. Theranostics, 2015, 5(10): 1122-1143

[7] KalkavanH, GreenDR. MOMP, cell suicide as a BCL-2 family business. Cell Death Differ, 2018, 25(1): 46-55

[8] LlambiF, GreenDR. Apoptosis and oncogenesis: Give and take in the BCL-2 family. Curr Opin Genet Dev, 2011, 21(1): 12-20

[9] GalluzziL, LarochetteN, ZamzamiN, et al.. Mitochondria as therapeutic targets for cancer chemotherapy. Oncogene, 2006, 25(34): 4812-4830

[10] LindnerAU, ConcannonCG, BoukesGJ, et al.. Systems analysis of BCL2 protein family interactions establishes a model to predict responses to chemotherapy. Cancer Res, 2013, 73(2): 519-528

[11] FlanaganL, LindnerAU, de ChaumontC, et al.. BCL2 protein signalling determines acute responses to neoadjuvant chemoradiotherapy in rectal cancer. J Mol Med (Berl), 2015, 93(3): 315-326

[12] ArraianoCM, AndradeJM, DominguesS, et al.. The critical role of RNA processing and degradation in the control of gene expression. FEMS Microbiol Rev, 2010, 34(5): 883-923

[13] WangG, ChenHW, OktayY, et al.. PNPASE regulates RNA import into mitochondria. Cell, 2010, 142(3): 456-467

[14] ChenHW, RaineyRN, BalatoniCE, et al.. Mammalian polynucleotide phosphorylase is an intermembrane space RNase that maintains mitochondrial homeostasis. Mol Cell Biol, 2006, 26(22): 8475-8487

[15] SatoR, Arai-IchinoiN, KikuchiA, et al.. Novel biallelic mutations in the PNPT1 gene encoding a mitochondrial-RNA-import protein PNPase cause delayed myelination. Clin Genet, 2018, 93(2): 242-247

[16] MatilainenS, CarrollCJ, RichterU, et al.. Defective mitochondrial RNA processing due to PNPT1 variants causes Leigh syndrome. Hum Mol Genet, 2017, 26(17): 3352-3361

[17] LiuX, FuR, PanY, et al.. PNPT1 Release from Mitochondria during Apoptosis Triggers Decay of Poly(A) RNAs. Cell, 2018, 174(1): 187-201.e12

[18] HouT, OuJ, ZhaoX, et al.. MicroRNA-196a promotes cervical cancer proliferation through the regulation of FOXO1 and p27Kip1. Br J Cancer, 2014, 110(5): 1260-1268

[19] GuerraF, ArbiniAA, MoroL. Mitochondria and cancer chemoresistance. Biochim Biophys Acta Bioenerg, 2017, 1858(8): 686-699

[20] SuzukiS, NaitoA, AsanoT, et al.. Constitutive activation of AKT pathway inhibits TNF-induced apoptosis in mitochondrial DNA-deficient human myelogenous leukemia ML-1a. Cancer Lett, 2008, 268(1): 31-37

[21] ParkSY, ChangI, KimJY, et al.. Resistance of mitochondrial DNA-depleted cells against cell death: Role of mitochondrial superoxide dismutase. J Biol Chem, 2004, 279(9): 7512-7520

[22] SanchoP, Burgos-RamosE, TaveraA, et al.. MYC/PGC-1α Balance Determines the Metabolic Phenotype and Plasticity of Pancreatic Cancer Stem Cells. Cell Metab, 2015, 22(4): 590-605

[23] YuJ, LiangQY, WangJ, et al.. Zinc-finger protein 331, a novel putative tumor suppressor, suppresses growth and invasiveness of gastric cancer. Oncogene, 2013, 32(3): 307-317

[24] XieX, HuY, XuL, et al.. The role of miR-125b-mitochondria-caspase-3 pathway in doxorubicin resistance and therapy in human breast cancer. Tumour Biol, 2015, 36(9): 7185-7194

[25] FioriME, VillanovaL, BarbiniC, et al.. miR-663 sustains NSCLC by inhibiting mitochondrial outer membrane permeabilization (MOMP) through PUMA/BBC3 and BTG2. Cell Death Dis, 2018, 9(2): 49

[26] GaoJM, HuangLZ, HuangZG, et al.. Clinical value and potential pathways of miR-183-5p in bladder cancer: A study based on miRNA-seq data and bioinformatics analysis. Oncol Lett, 2018, 15(4): 5056-5070

[27] ChenD, LiSG, ChenJY, et al.. MiR-183 maintains canonical Wnt signaling activity and regulates growth and apoptosis in bladder cancer via targeting AXIN2. Eur Rev Med Pharmacol Sci, 2018, 22(15): 4828-4836

[28] LiH, LiuL, ChangH, et al.. Downregulation of MCL-1 and upregulation of PUMA using mTOR inhibitors enhance antitumor efficacy of BH3 mimetics in triple-negative breast cancer. Cell Death Dis, 2018, 9(2): 137

[29] ZhangQA, YangXH, ChenD, et al.. miR-34 increases in vitro PANC-1 cell sensitivity to gemcitabine via targeting Slug/PUMA. Cancer Biomark, 2018, 21(4): 755-762

[30] CardenasC, MontagnaMK, PitruzzelloM, et al.. Adipocyte microenvironment promotes Bclxl expression and confers chemoresistance in ovarian cancer cells. Apoptosis, 2017, 22(4): 558-569