Abstract. The purpose of the present study was to evaluate the effects of uric acid in promoting tubular cell apoptosis and verify the role of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4)-induced oxidative stress in this process. HK-2 cells were used as a human proximal tubular cell model and co-cultured with various concentrations of uric acid with or without pre-treatment with the Nox4 inhibitor diphenylene iodonium (DPI). The apoptotic rate and the amount of reactive oxygen species (ROS) were examined by flow cytometry. Furthermore, levels of Nox4, phosphorylated (p)-P38, p-extracellular signal-regulated kinase (ERK), B-cell lymphoma 2 (Bcl-2) and Bcl-2-extra large (Bax) were detected by western blot analysis. The results showed that treatment with uric acid decreased HK-2 cell viability and promoted apoptosis in a dose-dependent manner. This was paralleled with an upregulation of Nox4 as well as ROS overproduction, which activated the phosphorylation of P38/ERK and caused an imbalance of Bax/Bcl-2 in HK-2 cells. Of note, inhibition of Nox4 with DPI prevented uric acid-induced cell injury by suppressing ROS generation and P38/ERK activation. In conclusion, it was demonstrated that elevated uric acid promoted ROS-induced tubular cell apoptosis by upregulating Nox4 expression. The present study therefore provided possible mechanisms and a potential therapeutic target of uric acid-induced chronic kidney disease.

Background Association of cigarette smoking habits with the risk of prostate cancer is still a matter of debate. This systematic review and meta-analysis aimed to assess the association between cigarette smoking and prostate cancer risk. Methods We conducted a systematic search on PubMed, Embase, Cochrane Library, and Web of Science without language or time restrictions on June 11, 2022. Literature search and study screening were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Prospective cohort studies that assessed the association between cigarette smoking habits and the risk of prostate cancer were included. Quality assessment was conducted using the Newcastle–Ottawa Scale. We used random-effects models to obtain pooled estimates and the corresponding 95% confidence intervals. Results A total of 7296 publications were screened, of which 44 cohort studies were identified for qualitative analysis; 39 articles comprising 3 296 398 participants and 130 924 cases were selected for further meta-analysis. Current smoking had a significantly reduced risk of prostate cancer (RR, 0.74; 95% CI, 0.68–0.80; P < 0.001), especially in studies completed in the prostate-specific antigen screening era. Compared to former smokers, current smokers had a significant lower risk of PCa (RR, 0.70; 95% CI, 0.65–0.75; P < 0.001). Ever smoking showed no association with prostate cancer risk in overall analyses (RR, 0.96; 95% CI, 0.93–1.00; P = 0.074), but an increased risk of prostate cancer in the pre-prostate-specific antigen screening era (RR, 1.05; 95% CI, 1.00–1.10; P = 0.046) and a lower risk of prostate cancer in the prostate-specific antigen screening era (RR, 0.95; 95% CI, 0.91–0.99; P = 0.011) were observed. Former smoking did not show any association with the risk of prostate cancer. Conclusions The findings suggest that the lower risk of prostate cancer in smokers can probably be attributed to their poor adherence to cancer screening and the occurrence of deadly smoking-related diseases, and we should take measures to help smokers to be more compliant with early cancer screening and to quit smoking. Trial registration This study was registered on PROSPERO (CRD42022326464).

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Kidney renal clear cell carcinoma (KIRC) is one of the most malignant diseases with poor survival rate over the world. The tumor microenvironment (TME) is highly related to the oncogenesis, development, and prognosis of KIRC. Thus, making the identification of KIRC biomarkers and immune infiltrates critically important. Microtubule Interacting and Trafficking Domain containing 1(MITD1) was reported to participate in cytokinesis of cell division. In the present study, multiple bioinformatics tools and databases were applied to investigate the expression level and clinical value of MITD1 in KIRC. We found that the expression of MITD1 was significantly increased in KIRC tissues. Further, the KIRC patients with high MITD1 levels showed a worse overall survival (OS) rate and disease free survival (DFS) rate. Otherwise, we found a significant correlation MITD1 expression and the abundance of CD8+ T cells. Functional enrichment analyses revealed that immune response and cytokine-cytokine receptor are very critical signaling pathways which associated with MITD1 in KIRC. In conclusion, our findings indicated that MITD1 may be a potential biomarker and associated with immune infiltration in KIRC.