Renal cell carcinoma (RCC) is a malignant tumor of the kidneys. Approximately 70% of RCC cases are clear cell renal cell carcinoma with von Hippel–Lindau (VHL) gene mutation and activation of the vascular endothelial growth factor (VEGF) pathway. Tyrosine kinase inhibitors (TKIs) targeting VEGF have emerged as promising agents for RCC treatment. Apart from primary resistance, acquired resistance to TKIs after initial tumor regression is common in RCC. Recently, immune checkpoint inhibition, including PD‐1/PD‐L1 blockade, alone or in combination with TKIs has improved the overall survival of patients with RCC. Ribonucleotide reductase subunit M2 (RRM2) has been reported in many types of cancer and has been implicated in tumor progression. However, the role of RRM2 in TKIs resistance in RCC remains unclear. In this study, the authors have demonstrated that RRM2 is upregulated in sunitinib‐resistant RCC cells and patient tissues. They also find that RRM2 stabilizes ANXA1 and activates the AKT pathway independent of its ribonucleotide reductase activity, promoting sunitinib resistance in RCC. Moreover, RRM2 regulated antitumor immune responses, and knockdown of RRM2 enhance the anti‐tumor efficiency of PD‐1 blockade in renal cancer. Collectively, these results suggest that aberrantly expressed RRM2 may be a promising therapeutic target for RCC.

The relationship between metformin and prostate cancer (PCa) remains controversial. To clarify this association, the PubMed, Embase and Cochrane library databases were systematically searched from their inception dates to May 23, 2018, using the keywords “metformin” and “prostate cancer” to identify the related studies. The results included incidence, overall survival (OS), PCa-specific survival (CSS) and recurrence-free survival (RFS), which were measured as hazard ratios (HR) with a 95% confidence interval (95% CI) using Review Manager 5.3 software. A total of 30 cohort studies, including 1,660,795 patients were included in this study. Our study revealed that metformin treatment improves OS, CSS and RFS in PCa (HR = 0.72, 95% CI: 0.59–0.88, P = 0.001; HR = 0.78, 95% CI: 0.64–0.94, P = 0.009; and HR = 0.60, 95% CI: 0.42–0.87 P = 0.006, respectively) compared with non-metformin treatment. However, metformin usage did not reduce the incidence of PCa (HR = 0.86, 95% CI: 0.55–1.34, P = 0.51). In conclusion, compared with non-metformin treatment, metformin therapy can significantly improve OS, CSS and RFS in PCa patients. No association was noted between metformin therapy and PCa incidence. This study indicates a useful direction for the clinical treatment of PCa.

Background: UBASH3B (STS1) is an important gene that negatively regulates T-cell receptor signaling in activated T-lymphocytes that involved in cancers. However, the function of UBASH3B in prostate cancer (PCa) and the correlation between UBASH3B and tumor-infiltrating immune cells still remain unclear. Methods: Real-time PCR and immunohistochemistry were applied to detect mRNA and protein expression of UBASH3B in PCa patients and benign prostate hyperplasia patients (BPH). Clinical features of patients with PCa were recorded and Kaplan Meier curve was subsequently plotted. Based on mRNA expression of UBASH3B, patients with PCa from TCGA database were divided into low-UBASH3B-expression group and high-UBASH3B-expression group for construct lncRNA-miRNA-mRNA network and analyzing GO and KEGG pathways. Single gene analysis method was performed by using GSEA to interpret gene expression data in PCa. The PPI network was constructed using STRING and the correlation between UBASH3B and tumor-infiltrating immune cells was analyzed by TIMER and CIBERSORT. Results: The mRNA and protein expression of UBASH3B were upregulated in PCa. The abundant expression of UBASH3B is associated with poor prognosis in PCa. The subnetwork of UBASH3B contains three lncRNAs (MIAT, LINC01297, MYLK-AS1) and four miRNAs (hsa-miR-200a-3p, hsa-miR-455-5p, hsa-miR-192-5p, hsamiR- 215-5P). The mRNA expression of UBASH3B was involved in 28 KEGG pathways. GSEA analysis showed that 18 hallmark gene sets were significantly enriched in high-UBASH3B-expression, whereas 1 gene set was enriched in low-UBASH3B-expression. PPI network revealed a tightly interaction between UBASH3B and LCP2 (an immune related gene). TIMER and CIBERSORT database indicated that UBASH3B was correlated with 11 types of tumor-infiltrating immune cells (naïve B cell, memory B cells, resting CD4⁺ memory T cell, activated CD4⁺ memory T cell, regulatory T cell, activated NK cell, M2 macrophages, resting dendritic cells, activated dendritic cells, resting mast cells, neutrophils). Conclusions: In conclusion, UBASH3B may be a novel potential prognostic biomarker and is associated with tumor-infiltrating immune cells in tumor microenvironment, suggesting UBASH3B as a potential target for future treatment of PCa.

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma and has the highest mortality rate. For metastatic RCC, systemic drug therapy is the most important method in addition to surgical tumor reduction. In recent years, tyrosine kinase inhibitors (TKIs) targeting the angiogenesis have been applied to treat ccRCC and achieved profound therapeutic effects. It has been reported that most patients receiving antiangiogenic therapy will develop resistance within 15 months. The mechanism of resistance to targeted therapy is extremely complex and has not been clarified. Ovarian tumor-associated protease domain-containing proteins (OTUDs) belonging to DUBs play a critical role in the tumorigenesis of solid tumors. However, the specific role of OTUDs in ccRCC is still elusive. Here, we investigated the clinicopathological role of OTUD family members in ccRCC. We demonstrated that OTUD1 was downregulated in renal cancer and involved in the poor prognosis of renal cancer. Then, we showed that OTUD1 inhibits cancer cell growth. Moreover, analysis of OTUD1 RNA-seq data indicated that OTUD1 inhibition triggers the AKT and NF-kappa B pathways in renal cancer cells. Furthermore, OTUD1 interacts with PTEN and regulates its stability. Subsequently, we revealed that downregulation of OTUD1 contributes to the sensitivity of renal cancer cells to TKIs, and this effect was blocked by TNF/NF-kappa B inhibitors and AKT inhibitors. Thus, we identified that the OTUD1-PTEN axis suppresses tumor growth and regulates the resistance of renal cancer to TKIs.

Clear cell renal cell carcinoma (ccRCC) accounts for 85% of all malignant renal tumors. Currently, the pathogenesis of ccRCC is not fully understood. Chromobox (CBX) family proteins are the major subunits of PcG complexes and are implicated in regulating mammalian development. The CBX family consists of eight members, namely, CBX1-8. Numerous studies have highlighted that each CBX protein exhibits distinct functions and prognostic roles in specific cancer types. In this study, in silico analysis indicated that CBX7 was downregulated in ccRCC and correlated with favorable prognosis in a ccRCC cohort. Subsequent studies showed that CBX7 inhibited cancer cell proliferation and invasion. Then, we showed that CBX7 downregulated ETS1 to inactivate the tumor necrosis factor (TNF) signaling pathway, which inhibited tumor proliferation and enhanced the sensitivity of ccRCC cells to tyrosine kinase inhibitors (TKIs). Moreover, we found that CBX7 was a bona fide substrate of RNF26. RNF26 promoted the degradation of CBX7 and enhanced ccRCC tumor growth. Therefore, our results revealed a novel RNF26/CBX7 axis that modulates the TNF signaling pathway in ccRCC.

Spider toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. The aim of the present investigation was to explore different antitumor effects of the spider peptide toxin lycosin-I through different pathways at different concentrations. It was found that by inactivating STAT3 pathway, high concentrations of lycosin-I induce apoptosis in prostate cancer cells and low concentrations of lycosin-I inhibit the migration of prostate cancer cells. This finding provides favorable evidence for further study of the molecular diversity of spider toxins. Impact statement: The spider peptide toxin has become an important research topic. These toxins are molecularly diverse and some display not only a strong antibacterial effect but also exhibit significant inhibition of tumor growth and promote tumor cell apoptosis. Inspired by previous studies, the present study aims to investigate the effects of different concentrations of lycosin-I on the invasiveness and apoptosis of human prostate cancer cells. The findings provide favorable evidence for further study of the molecular diversity of spider toxins.