microRNA 421 induces apoptosis of c-33a cervical cancer cells via down-regulation of Bcl-xL

MicroRNA-421 Inhibits Apoptosis by Downregulating Caspase-3 in Human Colorectal Cancer

Purpose

Dysregulated microRNAs (miRNAs/miRs) have been reported to play significant roles in pathogenesis of colorectal cancer (CRC). Previous studies have demonstrated that miR-421 regulates apoptosis in some cancers. Caspase-3 plays a key role in apoptosis, but the relationship between miR-421 and caspase-3 in CRC has not been determined. In this study, we investigated the role of miR-421 in CRC and the relationship between miR-421 and caspase-3.

Methods

Expression of miR-421 and caspase-3 were detected in human paired CRC cancer tissues and corresponding paracancerous tissues. In situ detection of tissue, apoptosis was performed via the TUNEL assay. HCT116 and SW480 cell lines were subjected to several in vitro experiments to explore the relationship between miRNA421 and caspase-3 during apoptosis using miR421 mimics/antagomir and luciferase reporter assay. Apoptosis was measured by determining the levels and activity of caspase-3 as well as DNA fragmentation. Luciferase reporter assay was performed to determine the potential interaction of miR-421 with caspase-3.

Results

The results showed that the expression of miR-421 in cancer tissues was higher than that in corresponding paracancerous tissues. Inhibition of miR-421 induced apoptosis, as shown by the upregulation of caspase-3 activity and expression as well as DNA fragmentation, which were attenuated by miR-421 mimic. We further showed that miR-421 targeted and inhibited CASP3 expression by targeting sites located in the 3ʹ-untranslated region (3ʹ-UTR) of CASP3 mRNA.

Conclusion

This study demonstrated an anti-apoptotic role of miR-421 in CRC and identified caspase-3 gene as a direct target of miR-421. These findings provide a potential treatment strategy using miR-421 as a therapeutic target for CRC.

Bone morphogenetic protein 4 regulates immortalized chicken preadipocyte proliferation by promoting G1/S cell cycle progression

Bone morphogenetic protein 4 (BMP4) has been reported to regulate adipose development, but its role in preadipocyte proliferation has not been explored in vitro. Here, we investigated the effect of BMP4 on chicken preadipocyte proliferation using immortalized chicken preadipocytes (ICP1 cells) as a cell model. We report that BMP4 expression increases during preadipocyte proliferation. Overexpression and knockdown of BMP4 promotes and inhibits preadipocyte proliferation, respectively. In addition, overexpression of BMP4 decreased the number of preadipocytes at the G0/G1 phase of the cell cycle, and increased the proportion of cells at S phase. In contrast, knockdown of BMP4 increased the number of preadipocytes at the G0/G1 phase of the cell cycle, and decreased the proportion of cells at the S and G2 phases. Furthermore, overexpression of BMP4 promoted the expression of proliferating cell nuclear antigen (PCNA), Id2, cyclin E, and cyclin‐dependent kinase 2 (CDK2), while knockdown of BMP4 inhibited the expression of Id2, cyclin E, and CDK2. Finally, neither BMP4 overexpression nor BMP4 knockdown affected cell apoptosis. Taken together, our results suggest that BMP4 may promote proliferation of ICP1 cells by driving cell cycle transition from G1 to S phase.

Role of miRNA in the regulation of cannabidiol-mediated apoptosis in neuroblastoma cells

Neuroblastoma (NBL) is one of the most common childhood cancers that originate from the immature nerve cells of the sympathetic system. Studies with NBL cancers have also shown that miRNAs are dysregulated and may play a critical role in pathogenesis. Cannabidiol (CBD) is a non-psychoactive compound found in marijuana which has been previously shown by our laboratory and others to induce apoptosis in cancer cells. However, there are no studies reported to test if CBD mediates these effects through regulation of miRNA. In the current study, therefore, we investigated if CBD induces apoptosis in human NBL cell lines, SH SY5Y and IMR-32, and if it is regulated by miRNA. Our data demonstrated that CBD induces apoptosis in NBL cells through activation of serotonin and vanilloid receptors. We also found that caspase-2 and -3 played an important role in the induction of apoptosis. CBD also significantly reduced NBL cell migration and invasion in vitro. Furthermore, CBD blocked mitochondrial respiration and caused a shift in metabolism towards glycolysis. CBD altered the expression of miRNA specifically, down-regulating hsa-let-7a and upregulating hsa-mir-1972. Downregulation of let-7a increased expression of target caspase-3, and growth arrest specific-7 (GAS-7) genes. Upregulation of hsa-mir-1972 caused decreased expression of BCL2L1 and SIRT2 genes. Together, our studies suggest that CBD-mediated apoptosis in NBL cells is regulated by miRNA.

MicroRNA-30e Functions as a Tumor Suppressor in Cervical Carcinoma Cells through Targeting GALNT7

Cervical cancer is the third most common cancer in women worldwide. However, the underlying mechanism of occurrence and development of cervical cancer is obscure. In this study, we observed that miR-30e was downregulated in clinical cervical cancer tissues and cervical cancer cells. Next, overexpression of miR-30e reduced the cervical cancer cell growth through MTT, colony formation, EdU, and Transwell assay in SiHa and Caski cells. Subsequently, UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7) was identified as a potential miR-30e target by bioinformatics analysis. Moreover, we showed that miR-30e was able to bind to the 3′UTR of GALNT7 by luciferase reporter assay. In addition, the mRNA and protein levels of GALNT7 in cervical cancer cells were downregulated by miR-30e. And we validated that downregulation of GALNT7 repressed the proliferation of SiHa and Caski cells by MTT, colony formation, and Transwell assay. We identified that the restoration of GALNT7 expression was able to counteract the effect of miR-30e on cell proliferation of cervical cancer cells. Furthermore, we found that the expression levels of GALNT7 were frequently upregulated and negatively correlative to those of miR-30e in cervical cancer tissues. In addition, we validated that restoration of GALNT7 rescued the miR-30e–suppressed growth of cervical cancer xenografts in vivo. In conclusion, the current results suggest that miR-30e may function as tumor suppressors in cervical cancer through downregulation of GALNT7. Both miR-30e and its novel target, GALNT7, may play an important role in the process of cervical cancer.

MicroRNAs in gynecological cancers: Small molecules with big implications

Gynecological cancers (GCs) are often diagnosed at advanced stages, limiting the efficacy of available therapeutic options. Thus, there remains an urgent and unmet need for innovative research for the efficient clinical management of GC patients. Research over past several years has revealed the enormous promise of miRNAs. These small non-coding RNAs can aid in the diagnosis, prognosis and therapy of all major GCs, viz., ovarian cancers, cervical cancers and endometrial cancers. Mechanistic details of the miRNAs-mediated regulation of multiple biological functions are under constant investigation, and a number of miRNAs are now believed to influence growth, proliferation, invasion, metastasis, chemoresistance and the relapse of different GCs. Modulation of tumor microenvironment by miRNAs can possibly explain some of their reported biological effects. miRNA signatures have been proposed as biomarkers for the early detection of GCs, even the various subtypes of individual GCs. miRNA signatures are also being pursued as predictors of response to therapies. This review catalogs the knowledge gained from collective studies, so as to assess the progress made so far. It is time to ponder over the knowledge gained, so that more meaningful pre-clinical and translational studies can be designed to better realize the potential that miRNAs have to offer.