Long Non-Coding RNA PVT1/miR-150/ HIG2 Axis Regulates the Proliferation, Invasion and the Balance of Iron Metabolism of Hepatocellular Carcinoma

Background/Aims: To investigate the biological roles and underlying molecular mechanisms of long non-coding RNA (lncRNA) PVT1 in Hepatocellular carcinoma (HCC). Methods: qRT-PCR was performed to measure the expression of miRNA and mRNA. Western blot was performed to measure the protein expression. CCK-8 assay was performed to determine cell proliferation. Flow cytometry was performed to detect cell apoptosis. Wounding-healing assay and Transwell assay was performed to detect cell migration and invasion. Dual luciferase reporter assay was performed to verify the target relationship. Quantichrom iron assay was performed to check uptake level of cellular iron. Results: PVT1 expression was up-regulated in HCC tissues and cell lines. Function studies revealed that PVT1 knockdown significantly suppressed cell proliferation, migration and invasion, and induced cell apoptosis in vitro. Furthermore, PVT1 could directly bind to microRNA (miR)-150 and down-regulate miR-150 expression. Hypoxia-inducible protein 2 (HIG2) was found to be one target gene of miR-150, and PVT1 knockdown could inhibit the expression of HIG2 through up-regulating miR-150 expression. In addition, the expression of miR-150 was down-regulated, while the expression of HIG2 was up-regulated in HCC tissues and cell lines. Moreover, inhibition of miR-150 could partly reverse the biological effects of PVT1 knockdown on proliferation, motility, apoptosis and iron metabolism in vitro, which might be associated with dysregulation of HIG2. In vivo results showed that PVT1 knockdown suppressed tumorigenesis and iron metabolism disorder by regulating the expression of miR-150 and HIG2. Conclusion: Taken together, the present study demonstrates that PVT1/miR-150/HIG2 axis may lead to a better understanding of HCC pathogenesis and provide potential therapeutic targets for HCC

PRPF19 facilitates colorectal cancer liver metastasis through activation of the Src-YAP1 pathway via K63-linked ubiquitination of MYL9

Abstract Distant metastasis is one of the leading causes of cancer-related mortality of colorectal cancer (CRC). Dysregulation of E3 ubiquitin ligases has been implicated in acting vital roles in multiple cancers. In this study, we found that the E3 ubiquitin ligase, PRPF19 was positively correlated with liver metastasis, and predicted a worse clinical outcome in CRC. However, the biological effects and the underlying molecular mechanisms of PRPF19 in CRC remain elusive thus far. We illustrated that PRPF19 promoted the migration and invasion capability of CRC cells in both gain- and loss- of function assays. Mechanistically, we uncovered that myosin light chain 9 (MYL9) was the downstream substrate of PRPF19. PRPF19 enhanced the stability of MYL9 via K63-linked ubiquitination, and promoted the migration and invasion capability of CRC cells in an MYL9-mediated manner. Furthermore, the Src–YAP1 cascade was identified as the downstream effector mechanism by which the PRPF19/MYL9 axis promoted metastasis in CRC. Taken together, our findings highlighted that the PRPF19/MYL9 axis served as a novel mechanism in CRC metastasis, which provided an attractive therapeutic strategy for CRC treatment