miR-194 Suppresses Proliferation and Migration and Promotes Apoptosis of Osteosarcoma Cells by Targeting CDH2

BACKGROUND/AIMS

Studies have shown that miR-194 functions as a tumour suppressor and is associated with tumour growth and metastasis. This study intends to uncover the mechanism of tumour suppression by miR-194. The expression of miR-194 in osteosarcoma cell lines and tissues were monitored by real-time PCR.

METHODS

The proliferation ability was examined by MTT assay. Migration and apoptosis of cells were monitored by migration assay and flow cytometry, respectively. The regulation of miR-194 on CDH2 was determined by luciferase assays and western blot assays.

RESULTS

The results showed that miR-194 was significantly reduced in osteosarcoma compared with that in normal bone tissue. Overexpression of miR-194 significantly attenuated the proliferation and migration and induced the apoptosis of osteosarcoma cells. Furthermore, we demonstrated that miR-194 has inhibited the malignant behaviour of osteosarcoma by downregulating CDH2 expression.

CONCLUSIONS

These findings suggested that miR-194 may act as a tumour suppressor in osteosarcoma. miR-194/CDH2 may be a novel therapeutic target in the treatment of osteosarcoma.

Phenethyl isothiocyanate (PEITC) suppresses prostate cancer cell invasion epigenetically through regulating microRNA-194

SCOPE

Tumor metastasis greatly contributes to the mortality of prostate cancer. The glucosinolate-derived phenethyl isothiocyanate (PEITC) has been widely documented to reduce the risk of prostate cancer by modulating multiple biologically relevant processes. Emerging evidence suggests that PEITC may exert its anti-cancer effects through epigenetic mechanisms including microRNAs. Altered levels of miRNA have been linked to tumor malignancy due to their capacity to regulate functional gene expression in carcinogenesis. Here, we assessed the effects of PEITC on miRNA expression which is related to PCa cell invasiveness.

METHODS AND RESULTS

Utilizing oligonucleotide microarray first identified the most affected miRNAs in LNCaP cells after PEITC treatment. Several top altered miRNAs were further validated using quantitative PCR. Interestingly, overexpression of miR-194 suppressed PC3 cell invasion in matrigel-coated Transwell chambers. Bone morphogenetic protein 1 (BMP1) was shown to be a direct target of miR-194. Downregulation of BMP1 by miR-194 or PEITC led to decreased expression of key oncogenic matrix metalloproteinases, MMP2 and MMP9. This in turn resulted in the suppression of tumor invasion.

CONCLUSION

Our results indicate that miR-194 downregulates the expression of oncogenic MMP2 and MMP9 by targeting BMP1, which suggests a potential new mechanistic target by which PEITC suppresses prostate cancer cell invasiveness.