Yuchi Li

Hsa-miR-1 downregulates long non-coding RNA urothelial cancer associated 1 in bladder cancer

MicroRNAs (miRNAs) are known to mainly target protein-coding genes at post-transcriptional level, resulting in mRNA destabilization and/or translational repression. Long non-coding RNAs (lncRNAs) are emerging as a novel set of targets for miRNAs. Here, we report that downregulated hsa-miR-1 and upregulated lncRNA urothelial cancer associated 1 (UCA1) were inversely expressed in bladder cancer. Hsa-miR-1 decreased the expression of UCA1 in bladder cancer cells in an Ago2-slicer-dependent manner. The binding site between UCA1 and hsa-miR-1 was confirmed. Overexpression of hsa-miR-1 inhibited bladder cancer cell growth, induced apoptosis, and decreased cell motility. Knockdown of UCA1 expression phenocopied the effects of upregulation of hsa-miR-1. Transfection of UCA1 expression vector partly reversed the changes caused by transfection of pre-miR-1 plasmids. This study provides evidence for hsa-miR-1 to play tumor suppressive roles via downregulating lncRNA UCA1 in bladder cancer, which may have potential therapeutic significance.

Epigenetic regulation and cancer (review).

Epigenetics is defined as the inheritable changes in gene expression with no alterations in DNA sequences. Epigenetics is a rapidly expanding field, and the study of epigenetic regulation in cancer is emerging. Disruption of the epigenome is a fundamental mechanism in cancer, and several epigenetic drugs have been proven to prolong survival and to be less toxic than conventional chemotherapy. Promising results from combination clinical trials with DNA methylation inhibitors and histone deacetylase inhibitors have recently been reported, and data are emerging that describe molecular determinants of clinical responses. Despite significant advances, challenges remain, including a lack of predictive markers, unclear mechanisms of response and resistance, and rare responses in solid tumors. Preclinical studies are ongoing with novel classes of agents that target various components of the epigenetic machinery. In the present review, examples of studies that demonstrate the role of epigenetic regulation in human cancers with the focus on histone modifications and DNA methylation, and the recent clinical and translational data in the epigenetics field that have potential in cancer therapy are discussed.

Functional elucidation of miR-494 in the tumorigenesis of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma has very high incidence and high mortality worldwide. MiRNA is related to the tumorigenesis and metastasis of a variety of tumors. In the present study, we verify that the expression of miR-494 in NPC tissues and NPC-derived cells was down-regulated, respectively. The proliferation, colony formation, migration, and invasion of NPC-derived cells were suppressed, while the cell apoptosis was promoted, when miR-494 was over-expressed in these cells. GALNT7 and CDK16 were confirmed to be the direct targets of miR-494. These results suggested that miR-494 play an inhibitory role in the tumorigenesis of NPC.

Identification of long-non coding RNA UCA1 as an oncogene in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults, which is associated with poor prognosis and high recurrence. Long non‑coding RNAs (lncRNAs) have been reported to be dysregulated in cancer and to be important in the regulation of carcinogenesis, thus suggesting that this class of molecules may be used as biomarkers in cancer. The lncRNA urothelial carcinoma associated 1 (UCA1) has been observed to be upregulated and to function as an oncogene in certain types of cancer; however, the role of UCA1 in RCC remains to be elucidated. The present study aimed to determine the expression and function of UCA1 in RCC. Quantitative polymerase chain reaction (qPCR) was used to determine the expression levels of UCA1 in 46 paired RCC and adjacent normal tissue samples. Furthermore, qPCR was used to determine the expression levels of UCA1 in four RCC cell lines compared with the human embryonic kidney 293T cell line. The impact of UCA1 on cell migration, proliferation and apoptosis was investigated by wound scratch assay, MTT and flow cytometry, respectively. The results of the present study demonstrated that UCA1 expression levels were significantly increased in RCC tissues and cells, as compared with the controls. Ectopic expression and gene silencing of UCA1 in RCC cell lines exerted opposite effects on cellular proliferation, migration and apoptosis, and the results suggested that UCA1 may function as an oncogene in RCC. These results indicated that UCA1 may be considered as a promising biomarker for diagnosis, and a therapeutic target in RCC. Further research is required to elucidate the role and target genes of UCA1 in RCC.

Upregulated microRNA-16 as an oncogene in renal cell carcinoma

MicroRNAs (miRs) are small, endogenous noncoding RNAs that serve a significant function in various biologic processes, including those involved in cancer. The present study aimed to determine the expression and function of miR-16 in renal cell carcinoma (RCC). Quantitative polymerase chain reaction was used to quantify the expression of miR-16 in 48 paired RCC tissues and adjacent normal tissues. The impact of miR-16 on cell proliferation, migration and apoptosis was analyzed by transfecting miR-16 mature molecules into the renal cancer cell lines 786-O and ACHN. The results indicated that miR-16 was significantly upregulated in RCC tissues (P<0.05). Downregulation of miR-16 resulted in reduced cell proliferation and migration and increased levels of apoptosis, while overexpression of miR-16 resulted in accelerated cellular proliferation and migration, suggesting that miR-16 may function as an oncogene in RCC. The present study demonstrated for the first time, to the best of our knowledge, that miR-16 is upregulated in RCC and acts as an oncogene by inducing cellular proliferation, migration and reducing apoptosis. Further study of miR-16 in RCC may clarify the molecular mechanisms of RCC carcinogenesis and aid in the development of novel biomarkers and therapeutic options.

Identification of miR‑125a‑5p as a tumor suppressor of renal cell carcinoma, regulating cellular proliferation, migration and apoptosis

miR‑125a‑5p has been previously described as a tumor suppressor in numerous malignancies, however the expression and function of miR‑125a‑5p in renal cell carcinoma (RCC) remains to be elucidated. In the present study, to explore the potential role of miR‑125a‑5p in RCC, quantitative polymerase chain reaction was used to determine the expression levels of miR‑125a‑5p in renal cancer tissues. The influence of miR‑125a‑5p on cell proliferation, migration and apoptosis was also determined, using an MTT assay, a wound scratch assay and flow cytometry, respectively. The expression of miR‑125a‑5p was shown to be decreased in RCC and the restoration of miR‑125a‑5p by synthetic mimics was shown to suppress cell proliferation and migration, and induce apoptosis. The present results indicate that miR‑125a‑5p may function as a tumor suppressor in RCC. The present study is, to the best of our knowledge, the first to demonstrate the downregulation of miR‑125a‑5p in RCC, and to show the role it has in affecting cellular proliferation, migration and apoptosis. Further research is needed to define the target genes of miR‑125a‑5p and explore the potential of miR‑125a‑5p as a diagnostic or a prognostic biomarker for RCC.

Oncogenic cAMP responsive element binding protein 1 is overexpressed upon loss of tumor suppressive miR-10b-5p and miR-363-3p in renal cancer

Renal cell carcinoma (RCC) is the most common kidney cancer in adults and has a poor prognosis. cAMP responsive element binding protein 1 (CREB1) is a proto‑oncogenic transcription factor involved in malignancies of various organs. However, its functional role(s) have not yet been elucidated in RCC. We investigated the expression pattern, function and regulation of CREB1 in RCC. CREB1 was overexpressed in the RCC tissues and cell lines. Downregulation of CREB1 inhibited RCC tumorigenesis by affecting cell proliferation, migration and apoptosis. Multiple computational algorithms predicted that the 3‑untranslated region (3‑UTR) of human CREB1 mRNA is a target for miR‑10b‑5p and miR‑363‑3p. Luciferase reporter assay, qPCR and western blot analysis confirmed that miR‑10b‑5p and miR‑363‑3p bind directly to the 3‑UTR of CREB1 mRNA and inhibit mRNA and protein expression of CREB1. qPCR data also revealed a significantly lower expression of miR‑10b‑5p and miR‑363‑3p in RCC tissues. Introduction of miR‑10b‑5p and miR‑363‑3p mimics led to suppressed expression of CREB1 and inhibited cell proliferation, migration and apoptosis reduction. Taken together, we propose that CREB1 is an oncogene in RCC and that upregulation of CREB1 by loss of tumor suppressive miR‑10b‑5p and miR‑363‑3p plays an important role in the tumorigenesis of RCC.

miR‑30a‑5p in the tumorigenesis of renal cell carcinoma: A tumor suppressive microRNA.

Renal cell carcinoma (RCC) is the most common type of malignant tumor of the adult kidney and has a poor prognosis. MicroRNAs (miRs) are important in a wide range of biological and pathological processes, including cell differentiation, migration, growth, proliferation, apoptosis and metabolism. The present study aimed to determine the role exerted by miR‑30a‑5p in the tumorigenesis of RCC. The expression levels of miR‑30a‑5p in RCC tissues and RCC‑derived cells were demonstrated to be significantly downregulated by real‑time quantitative polymerase chain reaction (RT‑qPCR). Wound scratch assay, cell proliferation assay and flow cytometric analysis revealed that the abilities of migration and proliferation of the RCC‑derived cells were suppressed, whereas cell apoptosis was promoted, when miR‑30a‑5p was overexpressed in these cells. N‑acetylgalactosaminyltransferasexa07 (GALNT7) was predicted to be one target gene of miR‑30a‑5p by bioinformatics analysis. Luciferase reporter assay, RT‑qPCR and western blotting were performed to confirm that GALNT7 is the direct conserved target of miR‑30a‑5p. These results suggested that miR‑30a‑5p has a tumor‑suppressive role in the tumorigenesis of RCC.

MicroRNA-20b-5p functions as a tumor suppressor in renal cell carcinoma by regulating cellular proliferation, migration and apoptosis

Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults and is associated with a poor prognosis due to a lack of early‑warning signs, protean clinical manifestations, and resistance to radiotherapy and chemotherapy. Recently, increasing evidence has suggested that microRNAs (miRNAs) are involved in the proliferation, invasion and apoptosis of various types of human cancer cells. In a previous study, miRNA expression profiles from renal cell carcinoma (RCC) revealed that expression of miR‑20b‑5p was significantly downregulated in RCC tissues. The aim of this study was to investigate the expression and functional significance of miR‑20b‑5p in RCC. The expression of miR‑20b‑5p was quantified in 48 paired RCC tissues and cell lines, and compared with adjacent normal tissues and the 293T cell line by reverse transcription‑quantitative polymerase chain reaction. The functional impact of miR‑20b‑5p on cell proliferation, cell migration and apoptosis in the 786‑O and ACHN RCC cell lines, was determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a scratch assay and flow cytometry. To the best of our knowledge, the present study was the first to reveal that miR‑20b‑5p was downregulated in RCC tissues and cell lines. It also demonstrated that upregulation of miR‑20b‑5p inhibited cellular migration and proliferation, and promoted cellular apoptosis, suggesting that miR‑20b‑5p functioned as a potential tumor suppressor. However, further studies are required to fully determine the effects of miR‑20b‑5p and the miR‑20b‑5p‑mediated molecular pathway in RCC and other types of cancer. In conclusion, these results imply that miR‑20b‑5p may be a biomarker for early detection and prognosis prediction, as well as a therapeutic target for RCC.

Downregulated microRNA-510-5p acts as a tumor suppressor in renal cell carcinoma

MicroRNA (miR)-510-5p has been demonstrated to be involved in a number of types of malignancy; however, the function of miR-510-5p in renal cancer remains unclear. The present study aimed to determine the expression of miR-510-5p in renal cell carcinoma (RCC) specimens and analyzed the impact of miR-510-5p on renal cancer by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound scratch and apoptosis assays. The results showed that miR-510-5p was significantly downregulated in RCC specimens compared with normal renal specimens. Overexpression of miR-510-5p by synthetic mature mimics reduced cell proliferation and migration and induced an increase in cell apoptosis, indicating that miR-510-5p may act as a tumor suppressor in RCC. The present study firstly revealed that downregulated miR-510-5p functioned as a tumor suppressor by reducing cellular proliferation and migration, and inducing apoptosis in RCC. Further research is required to define target genes of miR-510-5p to determine the cellular mechanism of miR-510-5p in the carcinogenesis of RCC.