RESUMO
PURPOSE: Recently, studies have demonstrated that a novel circular RNA (circRNA), circMAT2B, can promote cell proliferation and can thus contribute to the growth and development of hepatocellular carcinoma. However, the precise mechanisms underlying in circMAT2B-induced colorectal cancer (CRC) cell proliferation are not yet fully understood. MATERIALS AND METHODS: Quantitative reverse transcription polymerase chain reaction was conducted to evaluate circMAT2B expression in 70 CRC tissues and 70 matched adjacent normal tissues, CRC cell lines and human colonic epithelial cell line (NCM460). The direct interaction between miR-610 and circMAT2B or E2F1 was verified using luciferase reporter assay and biotinylated RNA Pull-down assay. Cell Counting Kit-8, colony formation assay, flow cytometry were utilized to examine the effect of circMAT2B, miR-610 and E2F1 on cell proliferation. Western blot was conducted to evaluate E2F1 expression. RESULTS: In our study, circMAT2B was found to be upregulated in CRC tissues and cell lines. Furthermore, the silencing of circMAT2B significantly inhibited proliferation. Hence, in order to investigate the mechanism underlying the oncogenic properties of circMAT2B in CRC, a bioinformatics analysis (circular RNA Interactome, https://circinteractome.nia.nih.gov/) was performed to screen the putative interacting microRNAs of circMAT2B. miR-610 was identified to be one of the potential targeted miRNAs of circMAT2B. Luciferase reporter and RNA pulldown assay confirmed a direct interaction between circMAT2B and miR-610. Moreover, circMAT2B expression was negatively correlated with the expression of miR-610 in CRC tissues (r=-0.5131, p<0.0001). Furthermore, we demonstrated circMAT2B upregulated expression levels of the miR-610 target gene E2F1, which is involved in cell proliferation, is overexpression in a broad range of human cancer including CRC. Further studies suggested that E2F1 upregulation could significantly reverse the si-circMAT2B-mediated inhibition of proliferation. CONCLUSION: circMAT2B is upregulated in CRC tissues and cell lines. Moreover, circMAT2B promoted CRC proliferation by regulating the miR-610/E2F1 axis, which may serve as a potential therapeutic target for CRC treatment.
RESUMO
BACKGROUND: RFA is designed to produce localized tumor destruction by heating the tumor and surrounding liver tissue, especially suitable for patients who do not qualify for hepatic resection. Many studies have reported that RFA was inferior to hepatectomy in the treatment of recurrent colorectal liver metastases. However, strong evidence is lacking in the literature. This study aimed to investigate the effect and clinical outcome of percutaneous ultrasound-guided RFA and repeat hepatic resection for recurrent colorectal liver metastases after hepatectomy. METHODS: From January 2007 to January 2014, 194 patients with recurrent colorectal liver metastases after hepatectomy diagnosed in our hospital was performed, and then divided into two groups based on different regimens: repeat hepatic resection group and RFA group. The clinical data of the two groups were analyzed. After treatment, the liver function-related indexes, complication rate, survival rate, and tumor recurrence of the two groups were recorded. The difference in short-term and long-term effects between repeat hepatic resection and RFA was identified by propensity score analysis. RESULTS: The number of metastases and the proportion of left and right lobe involved by tumor and preoperative chemotherapy in the RFA group were higher than those in the repeat hepatic resection group. The clinical data showed no significant difference between the two groups after using propensity score analysis. Compared with the RFA group, the liver function of the repeat hepatic resection group was significantly improved. After adjustment for potential confounders, no significant difference in liver function-related indexes was found between RFA and repeat hepatic resection, and the incidence of complications in the RFA group was lower. In survival analysis, there was no significant difference in OS and DFS between the two groups. CONCLUSIONS: RFA is a safe and effective therapeutic option for patients with recurrent colorectal liver metastases after hepatectomy.
