ABSTRACT
PURPOSE: The expression of miR-489 is linked to tumor development and progression; nevertheless, its role in tumor growth and invasion of colorectal cancer (CRC) and the underlying mechanism has not been clarified. EXPERIMENTAL DESIGN: We used quantitative RT-PCR to measure the expression of mature miR-489 in human colorectal tissues and the corresponding CRCs. Targets of miR-489 were predicted with TargetScan and substantiated by dual-luciferase reporter assay. Furthermore, we did in vitro and in vivo analysis with expression vectors and small interfering RNAs, to elucidate the precise role of miR-489 and its target gene histone deacetylase 7 (HDAC7) on cell proliferation, survival, and invasion. RESULTS: Compared to the corresponding non-tumor tissues, miR-489 was frequently downregulated in CRC. By Kaplan-Meier analysis, we found that lower CRC recurrence free survival years in the group with elevated miR-489 expression than those with lower miR-489 expression. In addition, we examined that miR-489 obviously inhibited the migratory and invasive capability in CRC. In further study, we found that miR-489 targets the 3'-UTR of the HDAC7 transcript and downregulates its expression, and HDAC7 expression promoted tumor cell proliferation and invasion. We demonstrated that miR-489 suppresses tumor invasion and metastasis in CRC by targeting HDAC7. CONCLUSIONS: We identified that MiR-489 suppresses tumor growth and invasion in CRC by targeting HDAC7. The expression of miR-489 suggests CRC recurrence and metastasis, which shed crucial light on how miR-489 functions in CRC pathogenesis.
Subject(s)
Biomarkers, Tumor/metabolism , Cell Proliferation , Colorectal Neoplasms/pathology , Histone Deacetylases/metabolism , Liver Neoplasms/secondary , MicroRNAs/genetics , Neoplasm Recurrence, Local/pathology , Animals , Apoptosis , Biomarkers, Tumor/genetics , Cell Movement , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Disease Progression , Female , Gene Expression Regulation, Neoplastic , Histone Deacetylases/genetics , Humans , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Middle Aged , Neoplasm Invasiveness , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/metabolism , Prognosis , Survival Rate , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Dual graft liver transplantation has been demonstrated to be feasible as well as effective in increasing the donor pool and in preventing the potential for small-for-size syndrome. However, little is known about the pathophysiological and immune processes following dual graft liver transplantation due to the lack of appropriate animal models. The aim of this study, therefore, was to establish an improved rat model of dual graft liver transplantation, with long-term survival. Male inbred rats were used as both donors and recipients. One middle lobe together with another right middle lobe from the livers of two different donors were used as the dual grafts. The "basin-shaped anastomosis" technique was used to connect the suprahepatic inferior vena cava; "Y-shaped bridge" and "three-cuff" techniques were adopted for the anastomosis of the portal veins; and the "two-stent" technique was used for the anastomosis of the bile ducts. Six of the ten recipients survived for more than 100 days after dual graft liver transplantation. There was no difference in graft survival between dual and whole liver transplantation. The long-term survivors with dual grafts from two different donors had unobstructed portal vein flow, unobstructed biliary tract dilatation, normal graft function, and well-preserved hepatic structure. Therefore, this improved model will be potentially useful for evaluating the pathophysiological processes, immune responses between dual grafts and recipient, and mechanisms underlying the liver regeneration in dual grafts after dual graft liver transplantation.