Hespintor Negative Regulation of PI3K/Akt Pathway Induces Cell Cycle Arrest of Hepatocellular Carcinoma

The mechanism of Hespintor (a protein of serpin family) inhibitory action on the growth of inoculated hepatocellular carcinoma was studied in a model of human hepatoma in nude mice by using on long-noncoding RNA (lncRNA) sequencing. Two days after tumor transplantation, Hespintor or normal saline was injected into the caudal vein at a dose of 15 μg/kg (2 times a week over 4 weeks). The tumors were isolated in 4 weeks after subcutaneous injection of human hepatoma MHCC97-H cells. In Hespintor and control groups, the complementary DNA libraries of tumor tissues were established, and transcriptome sequencing was performed. Based on RNA-sequencing data, the differentially expressing lncRNA genes (DEGs lncRNA) were obtained, and functional enrichment and interaction analyses were performed to find the regulatory gene sets. Then, the network module division method was employed to identify the key genes of the Hespintor action, as well as to build the regulatory network and critical pathways associated with the key genes with validation of the results by Western blotting. The target gene sets regulated by DEGs lncRNA were mainly enriched in cell behavior, transcriptional regulation, and cell cycle. The PI3K/Akt signaling pathway related to the revealed gene sets plays a leading role in the antitumor action of Hespintor, targeted by this serpin to down-regulate expression levels of the cell cycle regulatory proteins Cyclin D1, P-Rb, CDK4, and CDK6, thereby arresting the cell cycle in G1/S phase.