MiR-4521 plays a tumor repressive role in growth and metastasis of hepatocarcinoma cells by suppressing phosphorylation of FAK/AKT pathway via targeting FAM129A.

Introduction: Globally, hepatocellular carcinoma (HCC) is the sixth most common malignancy and it has the fourth highest mortality. MicroRNAs play a significant part in biological processes in cell formation and advancement by targeting genes in many cancers including HCC. Objective: In the present study we examine the involvement of miR-4521 and FAM129A correlations in HCC occurrence and progression. Methods: Expression levels of miR-4521 and FAM129A in HCC tissues and cells were detected. Immunohistochemistry was carried out to detect expression of FAM129A, MMP9 and TIMP-1 in HCC tissues. Western blot assays were used to examine expression levels of different genes involve in signaling pathways. Transwell chamber, MTT and wound healing assays were performed to check cell migration, invasion and proliferation rates. Results: Overexpression of FAM129A positively correlated with upregulation of MMP9 and negatively correlated with TIMP-1 in HCC patient samples, which encouraged progression and metastasis of HCC. An antagonistic relation between miR-4521 and FAM129A was detected in current study, down-regulation of miR-4521 and up-regulation of FAM129A was demonstrated in HCC tissues and cell lines as compare to normal tissue samples and the normal cell line LO2. Overexpressing miR-4521 and silencing FAM129A impaired HCC cell migratory and invasive properties and suppressed cell proliferation. Mutually, miR-4521-FAM129A axial regulation inhibited in vitro proliferation of cells by promoting apoptosis through the p-FAK/p-AKT/MDM2/P53 and p-FAK/p-AKT/BCL-2/BAX/Cytochrome-C/Caspase-3/Caspase-9 pathways, respectively, and suppressed the migration and invasion capabilities of HCCLM3 and HepG2 cells via the TIMP-1/MMP9/MMP2 and p-FAK/p-AKT pathway. Conclusion: Our work found the axial regulation mechanism of miR-4521-FAM129A in HCC. Deficiency of miR-4521 and abundance of FAM129A synergistically enhanced cancer progression by increasing cell proliferation and malignant invasion and by inhibiting apoptosis. These discoveries suggest that miR-4521/FAM129A might play a vital role in hepatic cancer progression and could be a candidate for its therapy.

miR-124-3p Suppresses the Invasiveness and Metastasis of Hepatocarcinoma Cells via Targeting CRKL.

Abnormal expressions of microRNAs are involved in growth and progression of human cancers including hepatocellular carcinoma (HCC). An adaptor protein CRKL plays a pivotal role in HCC growth, whereas miR-124-3p downregulation is associated with clinical stage and the poor survival of patients. However, the relationship between miR-124-3p and CRKL and the molecular mechanisms through which they regulate HCC metastasis remains unclear. In the current work, we explored miR-124-3p and its correlation with CRKL expression in HCC patient tissues. We found that miR-124-3p deficiency is inversely co-related with CRKL overexpression in tumorous tissues of HCC patients, which was also consistent in HCCLM3 and Huh7 HCC cell lines. Target validation data shows that miR-124-3p directly targets CRKL. The overexpression of miR-124-3p reverses the CRKL expression at both mRNA and protein levels and inhibits the cell development, migration, and invasion. Mechanistic investigations showed that CRKL downregulation suppresses the ERK pathway and EMT process, and concomitant decrease in invasion and metastasis of HCC cells. The expressions of key molecules in the ERK pathway such as RAF, MEK, ERK1/2, and pERK1/2 and key promoters of EMT such as N-cadherin and vimentin were downregulated, whereas E-cadherin, a key suppression indicator of EMT, was upregulated. MiR-124-3p-mediated CRKL suppression led to BAX/BCL-2 increase and C-JUN downregulation, which inhibited the cell proliferation and promoted the apoptosis in HCC cells. Collectively, our data illustrates that miR-124-3p acts as an important tumor-suppressive miRNA to suppress HCC carcinogenesis through targeting CRKL. The miR-124-3p-CRKL axial regulated pathway may offer valuable indications for cancer research, diagnosis, and treatment.