Search

Exosomes carrying microRNAs (miRNAs) have been demonstrated to play critical roles in the regulation of development, growth and metastasis of cancer. Bioinformatic predictions identified differentially expressed SRY-box 9 (SOX9) in OC, and the regulatory miRNA miR-139-5p. Here, we aim to evaluate the function of exosomal miR-139-5p in the sensitivity of ovarian cancer (OC) cells to cis-diamminedichloroplatinum(II) (DDP). Expression pattern of miR-139-5p and SOX9 in ovarian cancer cells (SKOV3) and DDP-resistant cells (SKOV3/DDP) was identified using reverse transcription quantitative polymerase chain reaction and western blot analysis. The relationship between miR-139-5p and SOX9 was validated using a dual-luciferase reporter assay. SKOV3/DDP cell line was developed and introduced with miR-30a-5p mimic to analyse the effects of miR-30a-5p on resistance to DDP. The in vitro and in vivo effects of exosomal miR-30a-5p on resistance of SKOV3 cells to DDP were assessed in a co-culture system of exosomes and OC cells as well as in tumour-bearing nude mice. High expression of SOX9 and low expression of miR-30-5p were witnessed in OC. Furthermore, miR-30-5p, a downregulated miRNA in SKOV3/DDP cells, increased the rate of cell apoptosis and enhanced the sensitivity of SKOV3/DDP cells to DDP by targeting SOX9. Moreover, exosomes carrying miR-30a-5p were identified to sensitize SKOV3/DDP cells to DDP both in vitro and in vivo . These data together supported an important conclusion that DDP-resistant OC cell-derived exosomal miR-30a-5p enhanced cellular sensitivity to DDP, highlighting a potential strategy to overcome drug resistance.

Our previous study reported that microRNA (miR)-30a-5p upregulation under hypoxia postconditioning (HPostC) exert a protective effect on aged H9C2 cells against hypoxia/reoxygenation injury via DNA methyltransferase 3B-induced DNA hypomethylation at the miR-30a-5p gene promoter. This suggests that miR-30a-5p may be a potential preventative and therapeutic target for ischemic heart disease in aged myocardium. The present study aimed to investigate the underlying mechanisms of miR-30a-5p transcription in aged myocardium in ischemic heart disease. Cardiomyocytes were treated with 8 mg/ml D-galactose for 9 days, and then exposed to hypoxic conditions. Cell viability was determined using a cell viability assay. Expression levels of histone deacetylase 2 (HDAC2), LC3B-II/I, beclin-1 and p62 were detected via reverse transcription-quantitative PCR and western blotting. Chromatin immunoprecipitation-PCR and luciferase reporter assays were performed to evaluate the effect of c-Myc binding and activity on the miR-30a-5p promoter in senescent cardiomyocytes following HPostC. It was found that HPostC enhanced the acetylation levels of H3K14 at the miR-30a-5p gene promoter in senescent cardiomyocytes, which attributed to the decreased expression of HDAC2. In addition, c-Myc could positively regulate miR-30a-5p transcription to inhibit senescent cardiomyocyte autophagy. Mechanically, it was observed that increased H3K14 acetylation level exposed to romidepsin facilitated c-Myc binding to the miR-30a-5p gene promoter region, which led to the increased transcription of miR-30a-5p. Taken together, these results demonstrated that HDAC2-mediated H3K14 hyperacetylation promoted c-Myc binding to the miR-30a-5p gene promoter, which contributed to HPostC senescent cardioprotection.

Renal ischemia/reperfusion (I/R) injury often occurs during multiple organ failure and sepsis, and autophagy may serve a role in I/R injury. The aim of the present study was to explore the effect of microRNA (miR)-30a-5p on autophagy in renal I/R injury. miR-30a-5p and autophagy-related protein expression levels in renal I/R injury mouse models and in hypoxia/re-oxygenation HK-2 cell models were determined using reverse transcription-quantitative PCR or western blotting; apoptosis was analyzed using flow cytometry. The effects of miR-30a-5p, Beclin-1 and autophagy-related gene 16 (ATG16) on the proliferation and autophagy of HK-2 cells were analyzed through gain- and loss-of-function studies. miR-30a-5p expression was significantly decreased after renal I/R injury in the in vivo and in vitro experiments. Renal I/R injury led to upregulated expression of autophagy-related proteins microtubule-associated protein light chain 3 (LC3)-II and Beclin-1, and downregulated expression of p62. miR-30a-5p overexpression decreased the number of LC3 punctae, decreased HK-2 cell apoptosis, increased p62 expression and decreased LC3-II and Beclin-1 expression. Inhibition of miR-30a-5p exhibited the opposite effects. A luciferase reporter assay demonstrated that miR-30a-5p targeted Beclin-1. Beclin-1 overexpression led to a significant increase in LC3-II expression and a decrease in p62 expression, as well as a significant increase in apoptosis. Beclin-1 overexpression also increased the protein expression level of ATG16. Downregulation of Beclin-1 decreased the expression of LC3-II, elevated the p62 level and decreased apoptosis. ATG16 knockdown showed similar effects as those of Beclin-1 downregulation. In conclusion, miR-30a-5p was increased in renal I/R injury and might mitigate autophagy by regulating the Beclin-1/ATG16 pathway.

MicroRNA-30a-5p (miR-30a-5p), which functions as a tumor suppressor, has been reported to be downregulated in colorectal cancer (CRC) tissues and to be associated with cancer invasion. However, the detailed regulatory mechanism of curcumol in the malignant progression of CRC remains unknown. MTT, Transwell, scratch, western blotting and reverse transcription-quantitative PCR assays were performed to examine how curcumol inhibited CRC cell viability, invasion and migration, and to detect the role of miR-30a-5p and curcumol in the invasion and Hippo signaling pathways of CRC cells. The present study revealed that miR-30a-5p expression was downregulated in human CRC tissues and cells. The results demonstrated that miR-30a-5p downregulation was accompanied by the inactivation of the Hippo signaling pathway, which was demonstrated to promote CRC cell viability, invasion and migration. Curcumol treatment was identified to increase miR-30a-5p expression and to activate the Hippo signaling pathway, which in turn inhibited the invasion and migration of CRC cells. Overexpression of miR-30a-5p enhanced the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. Furthermore, downregulation of miR-30a-5p reversed the effects of curcumol on cell invasion and migration, and the Hippo signaling pathway in CRC cells. These findings identified novel signaling pathways associated with miR-30a-5p and revealed the effects of curcumol on miR-30a-5p expression. Therefore, curcumol may serve as a potential therapeutic strategy to delay CRC progression.

Curcumin has been shown to inhibit the growth of a variety of tumor cells. However, the biological functions of curcumin in prostate cancer (PCa) have not yet fully elucidated. The objective of the present study was to investigate the role of curcumin on the proliferation, migration, invasion and apoptosis of PCa cells and the underlying mechanism. Cell Counting Kit-8 and flow cytometry were used to detect the effects of curcumin at different concentrations on the proliferation and apoptosis of PCa cell lines, PC-3 and DU145. BrdU and Transwell assays, western blotting and reverse transcription-quantitative PCR were used to determine the effect of curcumin on cell proliferation, migration and invasion, apoptosis-related protein expression, and microRNA (miR)-30a-5p and PCNA clamp associated factor (PCLAF) expression, respectively. In addition, bioinformatics analysis and Pearson's correlation test were used to verify the relationship between miR-30a-5p and PCLAF. Curcumin was observed to impede the proliferation, migration and invasion of PCa cells, and promote their apoptosis in a time- and dose-dependent manner. Curcumin enhanced miR-30a-5p expression and inhibited PCLAF expression; furthermore, there was a negative correlation between miR-30a-5p and PCLAF expression in PCa tissues. In addition, transfection of miR-30a-5p inhibitors partially reversed the function of curcumin on cell proliferation, migration, invasion and apoptosis. Overall, curcumin suppressed the malignant biological behaviors of PCa cells by regulating the miR-30a-5p/PCLAF axis.

Background/Aims: MiR-30a-5p, a member of the microRNA-30 family (miR-30), is known to function as a tumor suppressor in several different cancers. However, the expression levels, biological function, and underlying mechanisms of miR-30a-5p in renal cell carcinoma (RCC) remain unclear. Glucose-regulated protein78 (GRP78) is a common cancer biomarker and promotes the growth and survival of cancer cells. The expression of GRP78 has been reported to be modulated by miR-30a in neurons. In this study, the expression profile of miR-30a-5p in clear cell renal cell carcinoma (ccRCC) and its effect on ccRCC through regulating GRP78 expression was investigated. Methods: MiR-30a-5p expression was analyzed using bioinformatic software on open microarray datasets from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), and confirmed by quantitative RT-PCR (qRT-PCR) in ccRCC cell lines. Cell proliferation was investigated using CCK-8 and cell count assays. Western blotting, immunohistochemistry, luciferase reporter assays, and flow cytometry were employed to investigate the mechanisms of the effect of miR-30a-5p on ccRCC Results: MiR-30a-5p was down-regulated in ccRCC and related to the clinicopathological factors and prognosis of ccRCC. MiR-30a-5p was found to both suppress the growth of ccRCC cells and promote apoptosis of ccRCC cells in vitro. GRP78 was the direct target gene of miR-30a-5p, and the GRP78 expression was inversely correlated with the expression of miR-30a-5p in vivo and in vitro. The functional studies of GRP78 overexpression or knockdown demonstrated that GRP78 promoted proliferation and anti-apoptosis of ccRCC cells, and the oncogenic activity of GRP78 resulting in by miR-30a-5p overexpression. Conclusion: MiR-30a-5p is a bona fide negative regulator of GRP78 expression, and the anti-tumor activity of miR-30a-5p in ccRCC is due at least in part to down-regulating GRP78 expression and modulating the unfolded protein response (UPR) pathway. Thus, miR-30-GRP78 interaction provides a novel therapeutic candidate target in ccRCC treatment.

MicroRNAs (miRs) are a class of small non-coding RNAs of 18–25 nucleotides in length that serve as key regulators in the development and progression of human cancers. Recently, miR-30b-5p, as a member of the miR-30 family, has been reported to act as a tumor suppressor in gastric cancer. However, the expression and function of miR-30a-5p in gastric cancer, as well as the corresponding underlying mechanism, remain unknown. In the present study, it was demonstrated that the expression of miR-30a-5p was significantly reduced in gastric cancer tissues (n=43) compared with normal gastric tissues (n=10; P

Pulmonary arterial hypertension (PAH) is a fatal and currently incurable cardiopulmonary disease. Numerous microRNAs (miRNAs) serve important roles in the development of PAH. While the expression of miR-30a-5p was downregulated in the lung tissue of rats in a pulmonary hypertension rat model, the expression pattern and function of miR-30a-5p in human PAH remain unclear. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to examine miR-30a-5p and chitinase-3-like protein 1 (YKL-40) mRNA expression levels. The expression levels of YKL-40 and apoptosis-associated proteins were measured by western blot analysis. Cell proliferation assays and flow cytometry analysis were performed to examine cell proliferation and apoptosis, respectively. The association between miR-30a-5p and YKL-40 was determined by a luciferase reporter assay, RT-qPCR and western blot analysis. The relative expression levels of miR-30a-5p in plasma were increased in patients with PAH [median=13.23 (25th percentile=6.388, 75th percentile=21.91)] compared with normal controls [median=2.25 (25th percentile=1.4, 75th percentile=3.7). The expression of miR-30a-5p was significantly downregulated while the protein expression of YKL-40 was significantly upregulated in hypoxia-induced human pulmonary artery endothelial cells (HPAECs) when compared with the hypoxia-induced group at 0 h. miR-30a-5p overexpression promoted HPAEC growth and inhibited apoptosis of HPAECs under hypoxia. A miR-30a-5p mimic decreased the luciferase activity of a luciferase reporter construct containing YKL-40 3′-untranslated region and also decreased YKL-40 protein expression. YKL-40 overexpression partly alleviated the effects of miR-30a-5p upregulation on proliferation and apoptosis of HPAECs under hypoxia. In conclusion, the data indicated that miR-30a-5p promoted cell growth and inhibited apoptosis of HPAECs under hypoxia by targeting YKL-40. Therefore, the miR-30a-5p/YKL-40 axis may provide a potential target for the development of novel PAH therapies.

Keloids are benign fibrous overgrowths that occur as a result of abnormal wound healing following cutaneous injury. MicroRNAs (miRNAs/miRs) are short non-coding RNAs that serve critical roles in numerous important biological processes, such as cell proliferation, differentiation and apoptosis. However, their role in keloid development remains largely unknown. In the present study, the role of miR-30a-5p, a miRNA regulated by Trichostatin A (TSA), in apoptosis within cultured keloid fibroblasts was investigated. An MTT assay was used to detect the proliferation of cultured keloid fibroblasts treated with TSA. Cell apoptosis and cell cycle phases were analyzed using flow cytometry. In addition, an miRNA microarray was performed to compare expression profiles between cultured keloid fibroblasts treated with or without 1,000 nM TSA. Reverse transcription-quantitative polymerase chain reaction analysis was conducted to estimate miRNA expression levels. The direct target of miR-30a-5p was identified using a dual-luciferase reporter assay. Western blotting was employed to assess protein expression levels in keloid fibroblasts. The results demonstrated that TSA inhibited the proliferation of keloid fibroblasts in a time- and dose-dependent manner. The miRNA microarray revealed alterations in the expression of numerous miRNA sequences in response to TSA when compared with controls. Notably, the expression of miR-30a-5p was downregulated in keloid tissues. In addition, overexpression of miR-30a-5p induced apoptosis by targeting B-cell lymphoma 2, which was similar to that observed in response to TSA. These results provide important information regarding a novel miR-30a-5p-mediated signaling pathway induced by TSA treatment, and suggest a potential use for TSA and miR-30a-5p as effective therapeutic strategies for keloids.