Small hairpin RNA

About: Small hairpin RNA is a research topic. Over the lifetime, 9279 publications have been published within this topic receiving 285471 citations.

Expression and Functional Role of Reprogramming-Related Long Noncoding RNA (lincRNA-ROR) in Glioma

Abstract: The objective of the study was to investigate the expression and function of reprogramming-related long noncoding RNA (lincRNA-ROR) in glioma and glioma stem cells (GSCs). With real-time quantitative PCR, we analyzed lincRNA-ROR expression levels in 26 primary glioma patients and the expression correlation of lincRNA-ROR with SOX11 and KLF4. To explore its functional role, gain- and loss-of-function studies were performed to assess the effect of lincRNA-ROR on cell proliferation, expression rate of GSCs marker CD133, and glioma stem sphere-forming ability in vitro. We found that the lincRNA-ROR expression was significantly lower in glioma tissues than in adjacent normal tissues. Knockdown of lincRNA-ROR expression by small hairpin RNA (shRNA) significantly elevated the cell proliferation and enhanced the CD133 expression rate and glioma stem sphere-forming ability in U87 cells, while overexpression of lincRNA-ROR in U87 cells showed the opposite effect. Moreover, we found that the expression of lincRNA-ROR was negatively correlated with stem cell factor KLF4 and the “up- and down-regulation” of lincRNA-ROR resulted in inverse modulation of KLF4 messenger RNA (mRNA) expression. Our results suggest that the reprogramming-related lincRNA-ROR may serve as a novel tumor suppressor gene in glioma, which can inhibit the proliferation of cancer cell and self-renewal of GSCs, partly by inhibiting the KLF4 expression. Further research about lincRNA-ROR may provide a novel biomarker and therapeutic target of glioma for cancer clinic in future.

Targeting mTORC2 inhibits colon cancer cell proliferation in vitro and tumor formation in vivo.

Abstract: The mammalian target of rapamycin (mTOR), which exists in two functionally distinct complexes, mTORC1 and mTORC2 plays an important role in tumor growth. Whereas the role of mTORC1 has been well characterized in this process, little is known about the functions of mTORC2 in cancer progression. In this study, we explored the specific role of mTORC2 in colon cancer using a short hairpin RNA expression system to silence the mTORC2-associated protein rictor. We found that downregulation of rictor in HT29 and LS174T colon cancer cells significantly reduced cell proliferation. Knockdown of rictor also resulted in a G1 arrest as observed by cell cycle analysis. We further observed that LS174T cells deficient for rictor failed to form tumors in a nude mice xenograft model. Taken together, these results show that the inhibition of mTORC2 reduces colon cancer cell proliferation in vitro and tumor xenograft formation in vivo. They also suggest that specifically targeting mTORC2 may provide a novel treatment strategy for colorectal cancer.

Elevated expression of CDK4 in lung cancer

Abstract: The aim of the present study was to analyze the expression of Cyclin-dependent kinase 4 (CDK4) in lung cancer and its correlation with clinicopathologic features. Furthermore, the involvement of CDK4-mediated cell cycle progression and its molecular basis were investigated in the pathogenesis of lung cancer. Using immunohistochemistry analysis, we analyzed CDK4 protein expression in 89 clinicopathologically characterized lung cancer patients (59 males and 30 females) with ages ranging from 36 to 78 years and compared them to 23 normal lung tissues. Cases with cytoplasmic and nuclear CDK4 immunostaining score values greater than or equal to 7 were regarded as high expression while scores less than 7 were considered low expression. The correlation between the expression level of CDK4 and clinical features was analyzed. Furthermore, we used lentiviral-mediated shRNA to suppress the expression of CDK4 and investigate its function and molecular mechanism for mediating cell cycle progression. The expression level of CDK4 protein was significantly increased in lung cancer tissues compared to normal tissues (P < 0.001). In addition, high levels of CDK4 protein were positively correlated with the status of pathology classification (P = 0.047), lymph node metastasis (P = 0.007), and clinical stage (P = 0.004) of lung cancer patients. Patients with higher CDK4 expression had a markedly shorter overall survival time than patients with low CDK4 expression. Multivariate analysis suggested the level of CDK4 expression was an independent prognostic indicator (P < 0.001) for the survival of patients with lung cancer. Use of lentiviral-mediated shRNA to inhibit the expression of CDK4 in lung cancer cell line A549 not only inhibited cell cycle progression, but also dramatically suppressed cell proliferation, colony formation, and migration. Furthermore, suppressing CDK4 expression also significantly elevated the expression of cell cycle regulator p21 Overexpressed CDK4 is a potential unfavorable prognostic factor and mediates cell cycle progression by regulating the expression of p21 in lung cancer

RNA interference mediated inhibition of HIV gene expression using short interfering RNA

Abstract: The present invention concerns methods and reagents useful in modulating HIV gene expression in a variety of applications, including use in therapeutic, diagnostic, target validation, and genomic discovery applications. Specifically, the invention relates to small interfering RNA (siRNA) molecules capable of mediating RNA interference (RNAi) against HIV polypeptide and polynucleotide targets.