miRNA-155 modulates the malignant biological characteristics of NK/T-cell lymphoma cells by targeting FOXO3a gene.

This study investigated the effects of miRNA-155 on malignant biological characteristics of NK/T-cell lymphoma cell lines and the possible mechanism. The expression of miRNA-155 was detected in lymphoma cell lines from different sources (SNK-6, YTS, Jurkat and DOHH2) by real-time PCR. Lentiviral vectors (pLL3.7) that could overexpress or downexpress miRNA-155 were constructed. Recombinant lentiviral particles were prepared and purified, and their titers determined. The expression of miRNA-155 in the infected SNK-6 cells and the cell proliferation were detected by PCR and CCK-8, respectively. Flow cytometry was used to determine the apoptosis of infected SNK-6 cells. The target of miRNA155 was predicted from Targetscan website. The effect of miRNA155 on FOXO3a expression was examined by Western blotting. The results showed that among the human NK/T-cell lymphoma cell lines SNK-6, YTS, Jurkat and DOHH2, the expression of miRNA-155 was highest in SNK-6. The infection efficiency of the recombinant lentivirus in SNK-6 was more than 70% at multiplicity of infection (MOI) of 100. The expression of miRNA-155 was significantly increased in SNK-6 cells infected by lentivirus vectors with high expression of miRNA-155 (4 times higher than the control group), and profoundly decreased in those infected with lentiviruses with low expression of miRNA-155. The proliferation of letivirus-infected SNK-6 cells was decreased as the expression of miRNA-155 reduced. The apoptosis rate was increased with the reduction in the expression of miRNA-155. FOXO3a was found to be a possible target of miRNA155, as suggested by Targetscan website. Western blotting showed that the expression of FOXO3a was significantly elevated in SNK-6 cells with miRNA-155 inhibition. It was concluded that reduction in miRNA-155 expression can inhibit the proliferation of SNK-6 lymphoma cells and promote their apoptosis, which may be associated with regulation of FOXO3a gene.

MicroRNA-155 is a potential molecular marker of natural killer/T-cell lymphoma.

Natural killer/T-cell lymphoma (NKTCL) is characterized by its highly aggressive nature and rapid progression. MicroRNAs (miRNAs) play key roles in the development of NKTCL. We utilized next-generation Solexa high-throughput sequencing to compare miRNA expression in the SNK-6 and YTS NKTCL cell lines with expression in normal NK cells. We found that 195 miRNAs were upregulated in the SNK-6 cells and 286 miRNAs were upregulated in the YTS cells. Based on those results, we selected six miRNAs, including miRNA-155, and confirmed their expression using real-time polymerase chain reaction. Expression of miRNA-155 was higher in SNK-6 and YKS cells than in normal NK cells. We next determined the levels of miRNA-155 in the serum of healthy individuals and NKTCL patients, and correlated its expression with clinical parameters and inflammatory factors detected using enzyme-linked immunoabsorbent assays. Levels of miRNA-155 were higher in NKTCL patients' serum than in serum from healthy individuals. miRNA-155 expression was higher in patients with stable or progressive disease (SD+PD) than in those with partial or complete remission (PR+CR). While further studies are needed to clarify the underlying molecular mechanisms, it appears miRNA-155 may be a molecular marker of NKTCL.

Effect of VEGFR 2 gene polymorphism V297I on clinical outcomes of advanced NSCLC patients treated with bevacizumab combining with chemotherapy as first line treatment / 中国肿瘤生物治疗杂志

@# Objective: To investigate the effect of VEGFR2 gene polymorphism V297I on the clinical outcomes in patients with advanced non-small cell lung cancer (NSCLC) treated with bevacizumab combining with chemotherapy. Methods:Atotal of 135 patients with advanced NSCLC, who were treated by bevacizumab plus platinum-based chemotherapy for first-line regimen, were included in this study. PCR-RFLP assay was used to detect the VEGFR2 genotypes in peripheral blood of patients and qPCR was used to detect the VEGFR2 mRNA in the cancer tissues of NSCLC patients. Logistic regression analysis was used to analyze the correlation between gene polymorphism and other variants, Kaplan-Meier assay to analyze the correlation between genotype and prognosis, and Cox regression model to analyze the risk factors for patients’PFS. Results: Of the polymorphisms analyzed, only polymorphism V297I was found to be of clinical significance. V297I locates in the coding region of VEGFR2, and it’s prevalence in the study population was as follows: CC genotype in 99 cases (73.33%), CT genotype in 33 cases (24.44%) and TT genotype in 3 cases (2.23%); the frequency of minor allele was 0.14, and the distribution of three genotypes was in accordance with Hardy-Weinberg equilibrium (P>0.05). The overall objective remission rate (ORR) of the 135 patients was 45.93%, the median progression free survival (mPFS) was 8.2 months and the median overall survival (mOS) was 20.8 months. The ORR, mPFS and mOS of patients with CT/TT genotype and CC genotype were 41.67%, 6.2 months, 18.9 months and 47.47%, 8.9 months and 21.5 months, respectively (all P<0.05).Additionally, the mRNAexpression of VEGFR2 in cancer tissues of the patients with CT/TT genotype was significantly higher than those with CC genotype (P< 0.01). The risk factors for patients’PFS included V297I, gender and ECOG score. Conclusion:Among advanced NSCLC patients treated by bevacizumab plus platinum-based chemotherapy, the polymorphism V297I of VEGFR2 may impact the clinical outcomes and prognosis of NSCLC patients treated with bevacizumab first line treatment by influencing the mRNAexpression of VEGFR2.