ABSTRACT
The cyclin-dependent kinase inhibitor 3 (CDKN3) gene, is over expressed in renal cell carcinoma (RCC). However, the cell biology functions of RCC are not well understood. The present study aimed to verify the ability of CDKN3 to promote the proliferation and migration of RCC through in vitro experiments. Subsequently, the clinical prognostic effects were analyzed using The Cancer Genome Atlas (TCGA; https://www.cancer.gov/) and Gene Expression Omnibus (GEO; https://www.ncbi.nlm.nih.gov/geo/). The chelators, di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), an analogue of the anti-tumor agent, were screened through bioinformatics analysis. The expression of CDKN3 is positively correlated with the IC50 of Dp44mT. In two RCC cell lines, 786-0 and Caki-1, we conducted small interfering RNA (siRNA) knockdown of CDKN3 and overexpression of CDKN3 by transfection plasmid. Subsequently, we administered Dp44mT to examine the resulting alterations in cell proliferation, migration, and apoptosis, thereby elucidating the role of CDKN3 and Dp44mT in these processes. The results of the experiment revealed a positive association between CDKN3 expression and the proliferation of RCC cell lines. Down-regulating CDKN3 significantly increased the apoptosis rate and inhibited cell migration in 786-0 and Caki-1 cells. Furthermore, bioinformatics analysis revealed a high expression of CDKN3 in RCC and a negative association between CDKN3 expression and survival. Gene set enrichment analysis (GSEA) revealed a significant association between high CDKN3 expression and the cell cycle pathway. Furthermore, we identified Dp44mT as a drug highly correlated with CDKN3 through the database. Subsequent addition of Dp44mT resulted in similar findings to those observed upon CDKN3 knockdown. Our findings have important implications for the diagnosis and treatment of CDKN3 in RCC. Additionally, Dp44mT is likely to be a promising candidate for future clinical applications.
Subject(s)
Carcinoma, Renal Cell , Cell Movement , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor Proteins , Kidney Neoplasms , Humans , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/drug therapy , Cell Movement/drug effects , Cell Proliferation/drug effects , Kidney Neoplasms/pathology , Kidney Neoplasms/metabolism , Kidney Neoplasms/drug therapy , Kidney Neoplasms/genetics , Cell Line, Tumor , Cyclin-Dependent Kinase Inhibitor Proteins/metabolism , Cyclin-Dependent Kinase Inhibitor Proteins/genetics , Thiosemicarbazones/pharmacology , RNA, Small Interfering/metabolism , Antineoplastic Agents/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Dual-Specificity PhosphatasesABSTRACT
Recent studies revealed the relationship among homologous recombination repair (HRR), androgen receptor (AR), and poly(adenosine diphosphate-ribose) polymerase (PARP); however, the synergy between anti-androgen enzalutamide (ENZ) and PARP inhibitor olaparib (OLA) remains unclear. Here, we showed that the synergistic effect of ENZ and OLA significantly reduced proliferation and induced apoptosis in AR-positive prostate cancer cell lines. Next-generation sequencing followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed the significant effects of ENZ plus OLA on nonhomologous end joining (NHEJ) and apoptosis pathways. ENZ combined with OLA synergistically inhibited the NHEJ pathway by repressing DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and X-ray repair cross complementing 4 (XRCC4). Moreover, our data showed that ENZ could enhance the response of prostate cancer cells to the combination therapy by reversing the anti-apoptotic effect of OLA through the downregulation of anti-apoptotic gene insulin-like growth factor 1 receptor ( IGF1R ) and the upregulation of pro-apoptotic gene death-associated protein kinase 1 ( DAPK1 ). Collectively, our results suggested that ENZ combined with OLA can promote prostate cancer cell apoptosis by multiple pathways other than inducing HRR defects, providing evidence for the combined use of ENZ and OLA in prostate cancer regardless of HRR gene mutation status.
Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Prostatic Neoplasms, Castration-Resistant/genetics , Drug Resistance, Neoplasm/genetics , Cell Line, Tumor , Receptors, Androgen/genetics , Nitriles , ApoptosisABSTRACT
Neuroendocrine prostate cancer (NEPC), the most lethal subtype of castration-resistant prostate cancer (PCa), may evolve from the neuroendocrine differentiation (NED) of PCa cells. However, the molecular mechanism that triggers NED is unknown. Trigred motif 36 (TRIM36), a member of the TRIM protein family, exhibits oncogenic or anti-oncogenic roles in various cancers. We have previously reported that TRIM36 is highly expressed to inhibit the invasion and proliferation of PCa. In the present study, we first found that TRIM36 was lowly expressed in NEPC and its overexpression suppressed the NED of PCa. Next, based on proteomic analysis, we found that TRIM36 inhibited the glycolysis pathway through suppressing hexokinase 2 (HK2), a crucial glycolytic enzyme catalyzing the conversion of glucose to glucose-6-phosphate. TRIM36 specifically bound to HK2 through lysine 48 (lys48)-mediated ubiquitination of HK2. Moreover, TRIM36-mediated ubiquitination degradation of HK2 downregulated the level of glutathione peroxidase 4 (GPx4), a process that contributed to ferroptosis. In conclusion, TRIM36 can inhibit glycolysis via lys48-mediated HK2 ubiquitination to reduce GPX4 expression and activate ferroptosis, thereby inhibiting the NED in PCa. Targeting TRIM36 might be a promising approach to retard NED and treat NEPC.
