MiR-411-5p acts as a tumor suppressor in non-small cell lung cancer through targeting PUM1.

OBJECTIVE: The aim of this study was to investigate the expression of micro ribonucleic acid-411-5P (miR-411-5p) in non-small cell lung cancer (NSCLC), and to explore the effect of miR-411-5p on the biological behavior of NSCLC cells as well as the underlying molecular mechanism. PATIENTS AND METHODS: Quantitative Real Time- Polymerase Chain Reaction (qRT-PCR) was used to detect the expression level of miR-411-5p in NSCLC tissues and cells. MiR-411-5p mimics and relevant controls were transfected into NSCLC cells according to the instructions of Lipidosome 2000. Transfected cells were divided into the experimental group and the control group. The transfection efficiency of each group was detected by qRT-PCR. After miR-411-5p overexpression, methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, and transwell assay were used to detect the biological changes of cells in each group. Bioinformatics predicted that pumilio homolog 1 (PUM1) was the target gene of miR-411-5p. Subsequently, the mRNA and protein expression level of PUM1 in each group was detected by qRT-PCR and Western blotting, respectively. Dual-luciferase reporter assay was used to validate the target regulatory relationship between miR-411-5p and PUM1. RESULTS: The results of qRT-PCR showed that miR-411-5p was relatively lowly expressed in NSCLC tissues and cells. After miR-411-5p overexpression, MTT results revealed that the proliferation of NSCLC cells was decreased. Flow cytometry results indicated that the apoptosis rate of NSCLC cells was increased, and cell cycle was arrested in the G0-G1 phase. Meanwhile, the transwell assay demonstrated that the migration and invasion abilities of NSCLC cells were decreased. Bioinformatics predicted that PUM1 was the target gene of miR-411-5p. After miR-411-4p was overexpressed in NSCLC cells, qRT-PCR and Western blotting showed that both the mRNA and protein expression levels of PUM1 were up-regulated. Moreover, dual-luciferase reporter assay demonstrated that miR-411-5p could significantly inhibit the luciferase activity of wild-type PUM1-3'-untranslated region (3'-UTR). However, it exhibited no effect on the luciferase activity of cells transfected with mutant plasmids. CONCLUSIONS: MiR-411-5p may be involved in regulating the biological function of NSCLC cells via targeting PUM1. In addition, miR-411-5p may serve as a potential target for the molecular therapy of NSCLC.

MiR-203 is involved in osteoporosis by regulating DKK1 and inhibiting osteogenic differentiation of MSCs.

OBJECTIVE: To investigate whether miR-203 is involved in the osteogenic differentiation of rat mesenchymal stem cells (MSCs) by regulating DDK1, thus participating in the pathogenesis of osteoporosis. PATIENTS AND METHODS: miR-203 expression in serum samples of 60 osteoporosis patients and 60 normal subjects was detected using Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) assay. MSCs were isolated from bone marrow of rats and then identified. Subsequently, the effects of miR-203 and DKK1 on osteogenic differentiation were estimated by alkaline phosphatase (ALP) activity, alizarin red staining, ALP staining, respectively. Expression levels of osteogenic-specific genes were detected by Western blot. Rescue experiments were conducted to confirm whether miR-203 could promote osteogenic differentiation of MSCs by inhibiting DKK1. RESULTS: Serum level of miR-203 in osteoporosis patients was significantly lower than that of the normal subjects. Overexpressed miR-203 in MSCs enhanced ALP activity, expression of osteogenic marker genes and the number of calcified cells. Additionally, miR-203 could bind to DKK1. The regulatory effect of miR-203 on osteogenic differentiation in MSCs was reversed by DKK1. CONCLUSIONS: MiR-203 promotes the differentiation of rat MSCs into osteoblast-like cells, which may be associated with the regulation of DKK1 expression.

Association between expression of DNA mismatch repair genes and clinical features and prognosis of patients with radical resection of colon cancer.

The aim of this study was to investigate the clinical significance of the expression of DNA mismatch repair (MMR) genes in patients subjected to radical surgical removal of colon cancer, as well as their correlation with disease prognosis. Ninety stage II and III colon cancer patients who received laparoscopic radical resection of colon cancer at our hospital were recruited in this study. The expression of hMLH1, hMSH2, hMSH6, and hPMS2 in the resected tumor tissues was examined by SP immunohistochemistry, in order to analyze the relationship between defective DNA MMR (dMMR) and the clinico-pathological features and prognosis of colon cancer. Patients were followed up over a period of 5-35 months, and the Kaplan-Meier survival curve was plotted. dMMR was confirmed in 27 subjects (30.0%), among whom recurrence with metastasis and death was reported in 5 (18.5%) and 2 (7.4%) patients, respectively. The remaining 63 subjects displayed proficient DNA MMR (pMMR); among these, 19 (30.2%) and 7 (11.1%) recurrences with metastasis and death were reported, respectively. dMMR showed no significant correlation with gender, age, or therapeutic modality (P > 0.05), but was significantly correlated with the degree of differentiation, tumor location, number of resected lymph nodes, presence of ileus, and TNM stage (P < 0.05). The prognosis of patients with dMMR was better than that of patients with pMMR. dMMR serves as a biomarker for the prognosis of stage II/III colon cancers.