Background Long non-coding RNAs (lncRNAs) are crucial in the invasion, angiogenesis, progression, and metastasis of hepatocellular carcinoma (HCC). The lncRNA MYLK-AS1 promotes the growth and invasion of HCC through the EGFR/HER2-ERK1/2 signaling pathway. However, the clinical significance of MYLK-AS1 in HCC still needs to be further determined. Methods Bioinformatic analysis was performed to determine the potential relationship among MYLK-AS1, miRNAs and mRNAs. A total of 156 samples of normal liver and paired HCC tissues from HCC patients were used to evaluate MYLK-AS1 expression by qRT-PCR. Human HCC cell lines were used to evaluate the colony formation, cell proliferation, migration, invasion, cell cycle and apoptosis after transfection of lentiviral short-hairpin RNAs (shRNAs) targeting MYLK-AS1 or MYLK-AS1 vectors. The competitive endogenous RNA (ceRNA) mechanism was clarified using fluorescence in situ hybridization (FISH), Western blotting, qPCR, RNA binding protein immunoprecipitation (RIP), and dual luciferase reporter analysis. Results MYLK-AS1 up-regulation was detected in the HCC tumor tissues and cell lines associated with the enhancement of the angiogenesis and tumor progression. The down-regulation of MYLK-AS1 reversed the effects on angiogenesis, proliferation, invasion and metastasis in the HCC cells and in vivo. MYLK-AS1 acted as ceRNA, capable of regulating the angiogenesis in HCC, while the microRNA miR-424-5p was the direct target of MYLK-AS1. Promoting the angiogenesis and the tumor proliferation, the complex MYLK-AS1/miR-424-5p activated the VEGFR-2 signaling through E2F7, whereas the specific targeting of E2F transcription factor 7 (E2F7) by miR-424-5p, was indicated by the mechanism studies. Conclusions MYLK-AS1 and E2F7 are closely related to some malignant clinicopathological features and prognosis of HCC, thus the MYLK-AS1/ miR-424-5p/E2F7 signaling pathway might represent a promising treatment strategy to combat HCC.

Accumulating evidence has shown a critical role of long‐non‐coding RNAs (lncRNAs) during multiple tumor progression. However, the potential functions of LINC00504 in colon cancer as well as its mechanisms remain obscure. By lncRNA profiling, we identified LINC00504 as a novel oncogenic lncRNA in colon cancer. The lncRNA LINC00504 was markedly upregulated in colon cancer cell lines and specimens. LINC00504 increases viability and migration of colon cells in vitro. Furthermore, LINC00504 also enhances colon cancer xenograft tumors in vivo. We noted that LINC00504 regulates metabolism at a transcriptional level which influences multiple metabolic pathways, such as glucose metabolism, pentose phosphate pathway, and tricarboxylic acid cycle. Mechanistic study showed that LINC00504 could interact with c‐Myc to promote chromatin recruitment of c‐Myc and enhance its transactivation activity. Collectively, our results showed that LINC00504 serves as an important transcriptional regulator for c‐Myc in colon cancer cells. LINC00504 can reprogram central metabolism in colon cancer cells implying that LINC00504 may serve as a potential target for therapeutic intervention.

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