MicroRNA-20a Promotes Ovarian Cancer Cell OVCAR3Metastasis By Targeting APP And CCND1

Background and Objects:MicroRNAs (miRNAs) are a class of small non-coding RNAs that post-transcriptionally regulate gene expression. MiRNAs are involved in many physiological and pathological progresses. Recent evidence indicates that special miRNAs may function as oncogenes or tumor suppressors and play a critical role in cancer initiation and progression by negatively regulating their target genes. Recent reports implicate that they are very important regulatory molecules in regulating cancer cells proliferation and metastasis. In this study, we focused on the effects of miR-20a on human ovarian cancer cell line OVCAR3growth and metastasis. The direct and functional target genes of miR-20a were also identified in order to illuminate the molecular mechanism of miR-20a in ovarian cancer initiation and progression.Methods:To detect the effect of miR-20a on the proliferation and metastasis of OVCAR3ovarian cancer cell, miR-20a was either blocked or overexpressed in human ovarian cancer cell line OVCAR3and then cell vitality, proliferation activity and invasion activity were detected with MTT assay, colony formation assay and transwell invasion assay, respectively. Furthermore, the mRNA levels and protein levels of target genes in both miR-20a inhibited and overexpressed ovarian cancer cells were detected with semi-quantitative RT-PCR, real time PCR and western blot, in order to confirm the regulating roles of miR-20a in the expression of targets genes APP and CCND1. Finaly, APP and CCND1were knocked down by RNA interference, in order to study what the roles they played in OVCAR3cell.Results:When miR-20a was suppressed, the colony formation activity and invasion activity of OVCAR3were both inhibited. Inversely, when miR-20a was overexpessed, the colony formation activity and invasion activity of OVCAR3were both promoted. Furthermore, miR-20a had no effect on the vitality of OVCAR3cell. When miR-20a function was inhibited in ovarian cancer cell line, mRNA level of APP and CCND1were both elevated, protein level of APP was enhanced. When miR-20a function was overexpressed, the result is opposite. When APP and CCND1were blocked, it was no effect on the vitality of OVCAR3cell, but the colony formation activity was both promoted.Conelusions:In human ovarian cancer cell line OVCAR3, miR-20a promotes cell metastasis via regulating the target genes APP and CCND1. When miR-20a was blocked by the antisense oligonucleotides (ASO), the cell metastatic activity and cell proliferative activity were both suppressed, and cell viability was not affected. Inversely, when miR-20a was overexpressed by siRNA technology, cell metastatic activity was promoted and cell proliferative activity was slightly enhanced, while cell viability was not affected, either. Furthermore, using semi-quantitative RT-PCR, real time PCR and western blot assays, we detected that the mRNA level and protein level of APP and CCND1were conversely related with the miR-20a level, indicating that APP and CCND1were target genes of miR-20a in OVCAR3. When the function of APP and CCND1was blocked, the cell proliferative activity was enhanced, further illustrated that APP plays a key regulative role in ovarian cancer cell line OVCAR3.