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Background: MicroRNAs (miRNAs) function as potential diagnostic biomarkers in various cancers. This study aimed to evaluate the roles of miR‐205‐5p in lung cancer progression and diagnosis. Materials and Methods: MiR‐205‐5p was detected by quantitative real‐time PCR. The effect of miR‐205‐5p on cell proliferation and metastasis was estimated by MTT and flow cytometry. The expression of TP53INP1 and related genes was analyzed by immunoblotting. The diagnostic value of miR‐205‐5p was analyzed using receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity. Results: The miR‐205‐5p was increased in lung cancer tissues. MiR‐205‐5p mimics were promoted but its inhibitor suppressed cell proliferation and metastasis compared with control treatment in vitro and in vivo. By regulating the 3′ untranslated region, miR‐205‐5p could negatively regulate TP53INP1 expression, which further inhibited the expression of RB1 and P21, but increased that of cyclinD1. Moreover, the serum miR‐205‐5p levels of patients with lung cancer were significantly higher than those of normal controls, and they were correlated with patients' gender, drinking status, and clinical stage. The area under the ROC curve of serum miR‐205‐5p in the diagnosis of non‐small‐cell lung cancer was 0.8250, respectively. The finding supported its possession of high diagnostic efficiency for lung cancer. Conclusions: MiR‐205‐5p promoted lung cancer cell proliferation and metastasis by negatively regulating the novel target TP53INP1, which further affected the expression of P21, RB1, and cyclin D1. Serum miR‐205‐5p is a novel and valuable biomarker for lung cancer diagnosis. [ABSTRACT FROM AUTHOR]

Background: T-cell immunoglobulin domain and mucin domain 4 (TIM-4) is exclusively expressed in antigen-presenting cells and involved in immune regulation. However, the role of TIM-4 expressed in tumour cells remains completely unknown.Methods: Immunohistochemistry staining was used to examine TIM-4 or Ki-67 expression in tumour tissues. Real-time PCR or RT-PCR was performed to detect TIM-4 mRNA expression. Lung cancer cell growth and proliferation were conducted by CCK-8 assay and EdU staining. Cell cycle progression was analysed by flow cytometry. The PCNA and cell cycle-related proteins were verified by western blot. Co-IP assay was used to identify the interaction of TIM-4 and integrin αvβ3. The efficacy of TIM-4 in vivo was evaluated using xenograft tumour model.Results: The expression of TIM-4 in non-small-cell lung cancer (NSCLC) tissues was significantly higher than that of the adjacent tissues. Enhanced TIM-4 expression was negatively correlated with histological differentiation of lung carcinoma and lifespan of patients. Overexpression of TIM-4 promoted lung cancer cell growth and proliferation, and upregulated the expression of PCNA, cyclin A, cyclin B1 and cyclin D1, accompanied by accumulation of lung cancer cells in S phase. Interestingly, Arg-Gly-Asp (RGD) motif mutation abolished the effect of TIM-4 on lung cancer cells, which was further verified by tumour xenografts in mice. Furthermore, we found that TIM-4 interacted with αvβ3 integrin through RGD motif.Conclusions: This finding suggests that TIM-4 might be a potential biomarker for NSCLC that promotes lung cancer progression by RGD motif. [ABSTRACT FROM AUTHOR]