MicroRNA-7 (miR-7) has been described as a tumor suppressor in several human cancers, but the results of a study to identify miRNAs associated with metastatic capability in breast cancer suggested that miR-7 may be characterized as an oncogene. The present study was to determine the expression and function of miR-7 in renal cell carcinoma. Quantitative real-time polymerase chain reaction was used to validate the expressions of miR-7 in 48 paired renal cell carcinomas (RCC) and normal tissues, based on the preliminary sequencing results of miRNAs. Furthermore, the impacts of miR-7 on cell migration, proliferation and apoptosis were analyzed using wound scratch assay, MTT and flow cytometry, respectively. The results demonstrated that miR-7 was up-regulated in RCC compared with normal tissues (p = 0.001). Down-regulation of miR-7 with synthesized inhibitor inhibited cell migration in vitro, suppressed cell proliferation and induced renal cancer cell apoptosis, prompting that miR-7 could be characterized as an oncogene in RCC. The present study was the first to reveal that miR-7 was up-regulated in RCC and it played an important role in RCC by affecting cellular migration, proliferation and apoptosis. Further researches should be conducted to explore the roles and target genes of miR-7 in RCC and other cancers.

Urachal carcinomas are rare bladder malignances, which usually present at an advanced stage with a high risk of distant metastases and a poor prognosis. To improve understanding of this uncommon carcinoma, a retrospective review was conducted for the cases observed at Peking University Shenzhen Hospital and Peking University First Hospital. The clinical outcomes were analyzed for 17 patients with a diagnosis of urachal cancer, who were admitted to Peking University Shenzhen Hospital (Shenzhen, China) and Peking University First Hospital (Beijing, China) between 1998 and 2013. The TNM staging system was used to predict outcomes. Among the 17 study patients, there were 10 males and seven females, with a median age at diagnosis of 50 years. A total of four (23%) patients presented with lymph node or distant metastasis. The median overall survival time for all stages was 57.6 months, with five patients (38.4%) alive for more than five years following treatment. The application of the TNM staging system demonstrated a median survival time of 6.2 years for stage I/II patients, compared with a median survival of 1.8 years (log-rank, P<0.001) for patients with advanced disease (stages III and IV). In addition, no significant correlation was observed between tumor size and age, and survival. In conclusion, urachal carcinomas are usually locally advanced at presentation. Surgical excision remains the predominant choice of treatment and lymph node dissection is not required unless lymph node involvement is confirmed by preoperative examination. The current results indicated that the most significant predictor of prognosis was the tumor grade.

MicroRNAs (miRNAs) are an important class of small, non‑coding RNA molecules that regulate gene expression at the transcriptional or post‑transcriptional level. They are involved in apoptosis, proliferation and migration and are known to have an important role in many types of cancer. Aberrant expression of miRNA‑451a (miR‑451a) has previously been reported in tumors, however its role in renal cell carcinoma (RCC) is currently unknown. The aim of the present study was to investigate the role of miR‑451a in RCC. The expression of miR‑451a was analyzed in 50 paired RCC and normal tissues by quantitative polymerase chain reaction. Furthermore, the effects of miR‑451a on cell migration, proliferation and apoptosis were evaluated, using migration scratch, MTT and flow cytometric assays. The present study demonstrated that miR‑451a was upregulated in RCC, as compared with paired normal tissues (P<0.05). Downregulation of miR‑451a using a synthesized inhibitor, significantly suppressed cell migration and proliferation, and induced apoptosis of renal cancer cells in vitro, as compared with a negative control (P<0.05). In the present study, it was determined that miR‑451a may have an important role as a tumor enhancer in RCC. These results imply that miR‑451a may be a promising therapeutic target for the treatment of RCC.

Abstract. microRNAs (miRNAs; miR) are a class of small non-coding RNA molecules, which are involved in the pathogenesis of human diseases through the negative regulation of gene expression. Previous studies have demonstrated that miR-509-3p is a novel miRNA associated with cell proliferation and migration in 786-O renal cell carcinoma (RCC) cells. However, the mechanism of action of miR-509-3p in RCC remains to be elucidated. The present study aimed to examine the functional role and mechanism of miR-509-3p in the development of RCC. The results demonstrated that the expression levels of miR-509-3p were downregulated in the 786-O and ACHN RCC cell lines compared with the normal tissues of 10 patients with RCC, as determined by reverse transcription-quantitative polymerase chain reaction. The mRNA expression levels of mitogen-activated protein kinase kinase kinase 8 (MAP3K8) were upregulated in the RCC cell lines. Functional investigations demonstrated that the overexpression of miR-509-3p inhibited the migration and proliferation of the RCC cells, as determined by wound scratch and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Luciferase reporter assays revealed that the overexpression of miR-509-3p reduced the transcriptional activity of MAP3K8. Furthermore, the present study demonstrated that the ectopic transfection of miR-509-3p led to a significant reduction in the mRNA and protein expression levels of MAP3K8 in the RCC cells. Finally, knockdown of MAP3K8 inhibited the migration and proliferation of the RCC cells. Therefore, the results of the present study demonstrated that the miR-509-3p RCC suppressor was a significant regulator of the MAP3K8 oncogene, suggesting that it may have a potential therapeutic role in the treatment of RCC.

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.