Expression of microRNAs-106b in nonsmall cell lung cancer.

AIM: To explore the expression of microRNA-106b (miRNA-106b) in nonsmall cell lung cancer (NSCLC). SETTINGS AND DESIGN: miRNAs are short regulatory RNAs that negatively modulate gene expression at the posttranscriptional level, and are deeply involved in the pathogenesis of several types of cancer. miRNA-106b has been shown to play an oncogenic role in tumor progression. The expression of miRNA-106b is detected in this study. SUBJECTS AND METHODS: Quantitative reverse transcription polymerase chain reaction and Northern blotting were used to detect the expression level of miRNA-106b in 200 NSCLC samples. STATISTICAL ANALYSIS USED: All statistical analyses were performed using SPSS 16.0 software. Results were statistically evaluated using the Kruskal-Wallis test and Mann-Whitney U-test. Survival curves were estimated by the Kaplan-Meier method and P < 0.05 was considered to be statistically significant. RESULTS: miRNA-106b expression is increased in NSCLC tissues. Statistical analysis showed that overexpression of miRNA-106b was strongly associated with lymph node metastasis, stage of tumor node metastasis classification, and poor prognosis. Moreover, there was a significant difference in the miRNA-106b expression levels between smoking and nonsmoking patients. Multivariate Cox regression analysis showed that miRNA-106b was an independent prognostic factor for NSCLC patients. CONCLUSIONS: These data suggest that aberrantly expressed miRNA-106b may contribute to the development of NSCLC.

Overexpression of SKP2 Inhibits the Radiation-Induced Bystander Effects of Esophageal Carcinoma.

BACKGROUND: To investigate the effects of S-phase kinase protein 2 (SKP2) expression on the radiation induced bystander effect (RIBE) in esophageal cancer (EC) cells. MATERIALS AND METHODS: Western blot was used to detect the levels of SKP2, Rad51, and Ku70 in EC cells. Positive transfection, RNAi, micronucleus (MN), and γ-H2AX focus formation assay were used to investigate the effects of SKP2 on RIBE induced by irradiated cells. RESULTS: We found a significant negative correlation between SKP2 expression and MN frequency (p < 0.05) induced by RIBE. The results were further confirmed by positive transfection, RNAi, and rescue experiments.γ-H2AX focus formation assay results indicated that overexpression of SKP2 in the irradiated cells inhibited the DNA damage of RIBE cells. However, when SKP2 expression decreased in irradiated cells, the DNA damage of RIBE cells increased. Increased or decreased expression levels of SKP2 had effects on Rad51 expression under the conditions of RIBE. CONCLUSIONS: These results showed, for the first time, that SKP2 expression can inhibit RIBE of EC cells. The mechanism may function, at least partly, through the regulation of Rad51 in the ability to repair DNA damage.

[Expression of mir-106b in esophageal squamous cell carcinoma].

OBJECTIVE: To investigate the expression of mir-106b in esophageal squamous cell carcinoma (ESCC) tissue and analyze its correlation with the clinicopathologic features of ESCC. METHODS: A total of 200 fresh surgical specimens of ESCC and adjacent tissues collected between 2001 and 2007 were examined for expressions of mir-106b using real-time PCR (RT-PCR). Northern blot analysis for mir-106b was performed in 4 pairs of samples to confirm the RT-PCR results. The relationship between mir-106b expression and clinicopathological features and prognosis of the patients were analyzed. RESULTS: Mir-106b was expressed at significantly higher levels in ESCC tissues than in the paired adjacent tissues. Overexpression of mir-106b was associated with lymph node metastasis, stage of TNM classification and smoking (P<0.05). The survival rate of patients with low mir-106b expression was higher than that of patients with high mir-106b expression (60 vs 37 months, P=0.024). Cox regression analysis indicated that the expression of mir-106b, lymph node metastasis and smoking were independent prognostic factors for ESCC (P<0.05). CONCLUSION: Mir-106b is overexpressed in ESCC tumors, and its overexpression is strongly associated with lymph node metastasis and a poor prognosis. Mir-106b expression is an independent prognostic factor for ESCC and can serve as a biomarker for diagnosis and prognostic evaluation of ESCC.