Mechanism of nuclear protein 1 in the resistance to axitinib in clear cell renal cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To explore the potential mechanism of resistance to axitinib in clear cell renal cell carcinoma (ccRCC), with a view to expanding the understanding of axitinib resistance, facilitating the design of more specific treatment options, and improving the treatment effectiveness and survival prognosis of patients.@*METHODS@#By exploring the half maximum inhibitory concentration (IC50) of axitinib on ccRCC cell lines 786-O and Caki-1, cell lines resistant to axitinib were constructed by repeatedly stimulated with axitinib at this concentration for 30 cycles in vitro. Cell lines that were not treated by axitinib were sensitive cell lines. The phenotypic differences of cell proliferation and apoptosis levels between drug resistant and sensitive lines were tested. Genes that might be involved in the drug resistance process were screened from the differentially expressed genes that were co-upregulated in the two drug resistant lines by transcriptome sequencing. The expression level of the target gene in the drug resistant lines was verified by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB). The expression differences of the target gene in ccRCC tumor tissues and adjacent tissues were analyzed in the Gene Expression Profiling Interactive Analysis (GEPIA) public database, and the impact of the target gene on the prognosis of ccRCC patients was analyzed in the Kaplan-Meier Plotter (K-M Plotter) database. After knocking down the target gene in the drug resistant lines using RNA interference by lentivirus vector, the phenotypic differences of the cell lines were tested again. WB was used to detect the levels of apoptosis-related proteins in the different treated cell lines to find molecular pathways that might lead to drug resistance.@*RESULTS@#Cell lines 786-O-R and Caki-1-R resistant to axitinib were successfully constructed in vitro, and their IC50 were significantly higher than those of the sensitive cell lines (10.99 μmol/L, P < 0.01; 11.96 μmol/L, P < 0.01, respectively). Cell counting kit-8 (CCK-8) assay, colony formation, and 5-ethynyl-2 '-deoxyuridine (EdU) assay showed that compared with the sensitive lines, the proliferative ability of the resistant lines decreased, but apoptosis staining showed a significant decrease in the level of cell apoptosis of the resistant lines (P < 0.01). Although resistant to axitinib, the resistant lines had no obvious new replicated cells in the environment of 20 μmol/L axitinib. Nuclear protein 1 (NUPR1) gene was screened by transcriptome sequencing, and its RNA (P < 0.0001) and protein expression levels significantly increased in the resistant lines. Database analysis showed that NUPR1 was significantly overexpressed in ccRCC tumor tissue (P < 0.05); the ccRCC patients with higher expression ofNUPR1had a worse survival prognosis (P < 0.001). Apoptosis staining results showed that knockdown ofNUPR1inhibited the anti-apoptotic ability of the resistant lines to axitinib (786-O, P < 0.01; Caki-1, P < 0.05). WB results showed that knocking downNUPR1decreased the protein level of B-cell lymphoma-2 (BCL2), increased the protein level of BCL2-associated X protein (BAX), decreased the protein level of pro-caspase3, and increased the level of cleaved-caspase3 in the resistant lines after being treated with axitinib.@*CONCLUSION@#ccRCC cell lines reduce apoptosis through theNUPR1 -BAX/ BCL2 -caspase3 pathway, which is involved in the process of resistance to axitinib.

Clinicopathological analysis of patients with papillary renal cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinicopathological features,treatment and prognosis of patients with papillary renal cell carcinoma (PRCC) and PRCC-complicated with tumor thrombus.@*METHODS@#Single center retrospective analysis of 75 patients with PRCC treated from January 2012 to October 2017 was performed. There were 55 males and 20 females at an age range of 24-82 years. Sixteen PRCC patients were complicated with tumor thrombus. All the patients were with a surgery and had clear pathological diagnosis and detailed follow-up data. The clinicopathological features, prognosis and influencing factors of the patients with PRCC and PRCC complicated with tumor thrombus were analyzed and summarized.@*RESULTS@#The average age of the 75 patients was(56.05±11.59)years,the average body mass index (BMI) was (26±3) kg/m², and the average tumor maximum diameter was (5.17±3.85) cm. There were significant differences between tumor maximum diameter larger than 7 cm and less than 7 cm (69.6% vs. 94.4%, P<0.001), lymph node metastasis and no lymph node metastasis (<38% vs. 98%, P<0.001), adrenal metastasis and no adrenal metastasis (0% vs. 95.3%, P<0.001), pulmonary metastasis and no pulmonary metastasis (0% vs.90.7%, P<0.001), complicated with and without tumor thrombus (<66.4% vs. 93.5%, P<0.001) on the effect of 3-year survival rate of the PRCC patients. In this study, there were 16 patients with type 2 PRCC complicated with tumor thrombus. There were significant differences in concomitant symptoms (62.5% vs. 22.0%, P=0.005), maximum tumor diameter (68.8% vs.13.3%, P<0.001), adrenal metastasis (18.8% vs. 0.02%, P=0.029), pulmonary metastasis (18.8% vs. 0%, P=0.008), nuclear grade (P<0.001) and pathological type (100% vs. 44.1%, P<0.001) between the PRCC patients with and without tumor thrombus.@*CONCLUSION@#There were significant differences in tumor diameter,lymph node metastasis,adrenal metastasis, pulmonary metastasis,pathological type, nuclear grade and tumor thrombus in the effect of the 3-year survival rate of PRCC patients. PRCC patients with tumor thrombus were more commonly suffered from type 2 PRCC, for whom the tumor diameter was larger,the nuclear grade was higher,and the distance metastasis happened more easily.