Background: This study aimed to summarize the association between diabetes mellitus (DM) and the incidence of lung cancer using a meta‐analysis of cohort studies.Materials and methods: We systematically searched PubMed, Embase and the Cochrane Library to identify potential cohort studies. Relative risk (RR) was used to calculate the association between DM and the risk of lung cancer. Subgroup analysis, sensitivity analysis and test for publication bias were performed. Twenty cohort studies were selected.Results: The participants with DM showed little or no significant effect on the risk of lung cancer (RR: 1.10; 95% CI: 0.99‐1.23; P = .087). DM was not associated with the risk of lung cancer in men (RR: 1.11; 95%CI: 0.92‐1.35; P = .270), but a significant association was observed in women (RR: 1.18; 95%CI: 1.10‐1.28; P < .001). Subgroup analysis suggested that smoker status was confounding variables that could bias the relationship between DM and the incidence of lung cancer.Conclusions: This meta‐analysis suggests that DM has no significant impact on the incidence of lung cancer in men but has a harmful effect on women.

Glucose‑6‑phosphate dehydrogenase (G6PD) is crucial rate‑limiting enzyme of the pentose phosphate pathway (PPP). G6PD dysregulation has been reported in various types of human cancer, and the role of G6PD in cancer progression was demonstrated in numerous studies. A previous study from our laboratory described the prognostic significance of G6PD in clear cell renal cell carcinoma (ccRCC), and demonstrated its proliferative role through positive feedback regulation of the phosphorylated form of signal transducer and activator of transcription 3. However, the role of G6PD in ccRCC invasion remains unclear. In the present study, reverse transcription‑quantitative (RT‑q) PCR, western blotting, enzyme activity assay, transwell assay and immunohistochemistry analysis in cell model, xenograft mice model and human specimen studies were performed to evaluate the role of G6PD in ccRCC invasion. The results from the present study demonstrated that G6PD may promote ccRCC cell invasive ability by increasing matrix metalloproteinase 2 (MMP2) mRNA and protein expression both in vitro and in vivo. In addition, a positive correlation between G6PD and MMP2 expression was demonstrated by RT‑qPCR and western blotting in twenty pairs of ccRCC tumor specimens and matched adjacent normal tissues. Furthermore, G6PD promoted reactive oxygen species (ROS) generation and activated the MAPK signaling pathway in ccRCC cells. In addition, ROS significantly promoted the MAPK signaling pathway activation, which in turn contributed to MMP2 overexpression in ccRCC cells. In conclusion, the present study demonstrated that G6PD may facilitate ccRCC cell invasive ability by enhancing MMP2 expression through ROS‑MAPK axis pathway.

Background: Long intergenic non-coding RNA 00511 (LINC00511) is highly expressed in diverse cancers and has a correlation with poor clinical outcomes for cancer patients. In view of contradictory data among published data, we aim to evaluate the prognostic role of LINC00511 for cancer patients. Methods: In the present study, a meta-analysis of related studies has been performed to investigate the prognostic significance of LINC00511 in cancer patients. Relevant studies published before December 22, 2019 were systematically searched online in PubMed, EMBASE, Web of Science, and the Cochrane Library databases. The relationship between LINC00511 expression and cancer patients’ survival, including overall survival (OS), disease-free survival (DFS)/relapse-free survival (RFS) and progression-free survival (PFS), was evaluated using pooled hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs). The association between LINC00511 expression and clinicopathological features was assessed using odd ratios (ORs) and their corresponding 95% CIs. Results: A total of 14 eligible studies with 1883 patients were enrolled in the present meta-analysis. The results demonstrated that elevated expression of LINC00511 was significantly associated with poor OS (HR = 2.62; 95% CI: 2.00–3.45; p < 0.001), PFS (HR = 1.80; 95% CI: 1.29–2.51; p = 0.001) and DFS/RFS (HR = 2.90; 95% CI: 1.04–8.12; p = 0.04). Additionally, High LINC00511 expression was associated with large tumor size (OR = 3.10; 95% CI: 1.97–4.86; p < 0.00001), lymph node metastasis (OR = 3.11; 95% CI: 2.30–4.21; p < 0.00001), advanced clinical stage (OR = 3.95; 95% CI: 2.68–5.81; p < 0.00001), distant metastasis (OR = 2.39; 95% CI: 1.16–4.93; p = 0.02), and disease recurrence (OR = 4.62; 95% CI: 2.47–8.65; p < 0.00001). Meanwhile, no correlation was found between LINC00511 expression and age, gender, and histological grade. These findings were consolidated by the results of bioinformatics analysis. Conclusions: Based on our findings, LINC00511 may serve as a novel prognostic biomarker for cancer patients.