Knockdown of PKMYT1 is associated with autophagy inhibition and apoptosis induction and suppresses tumor progression in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a cancerous tumor that ranks as the third leading cause of cancer death across the globe. Protein kinase membrane-associated tyrosine/threonine kinase 1 (PKMYT1) is overexpressed in many cancer types, including HCC, but the potential mechanism and biological function of PKMYT1 are not fully understood. MATERIALS AND METHODS: The expression level of PKMYT1 was detected in human HCC tissues and adjacent tissues. We then established HCC cell lines with PKMYT1 knockdown and observed proliferation, migration, autophagy, apoptosis in cell lines and tumor growth in a nude mouse model. To investigate the underlying mechanism by which PKMYT1 regulates autophagy and apoptosis, RNA sequencing was performed in HCC-LM3 cells with and without PKMYT1 knockdown. RESULTS: Here, we observed that human HCC tissues had higher expression of PKMYT1 than adjacent tissues. Overexpression of PKMYT1 was closely associated with poor prognosis in HCC patients. PKMYT1 knockdown inhibited the proliferative potential and migration of HCC cell lines. We also found that downregulation of PKMYT1 inhibited autophagy and induced apoptosis. RNA sequencing analysis showed that the MAPK and PI3K-AKT pathways, which have been reported to affect autophagy and apoptosis, may be regulated after PKMYT1 knockdown by KEGG pathway enrichment analysis. Furthermore, we identified that knockdown of PKMYT1 attenuated the phosphorylation levels of p38 MAPK, ERK and PI3K/Akt/mTOR, which might mediate autophagy inhibition and apoptosis induction via these signaling pathways to inhibit the development of HCC. CONCLUSION: Our study suggests that PKMYT1 functions as an oncogene and may be a new target for HCC treatment.

Establishment and Validation of SSCLIP Scoring System to Estimate Survival in Hepatocellular Carcinoma Patients Who Received Curative Liver Resection.

BACKGROUND AND AIMS: There is no prognostic model that is reliable and practical for patients who have received curative liver resection (CLR) for hepatocellular carcinoma (HCC). This study aimed to establish and validate a Surgery-Specific Cancer of the Liver Italian Program (SSCLIP) scoring system for those patients. METHODS: 668 eligible patients who underwent CLR for HCC from five separate tertiary hospitals were selected. The SSCLIP was constructed from a training cohort by adding independent predictors that were identified by Cox proportional hazards regression analyses to the original Cancer of the Liver Italian Program (CLIP). The prognostic performance of the SSCLIP at 12 and 36-months was compared with data from existing models. The patient survival distributions at different risk levels of the SSCLIP were also assessed. RESULTS: Four independent predictors were added to construct the SSCLIP, including age (HR = 1.075, 95%CI: 1.019-1.135, P = 0.009), albumin (HR = 0.804, 95%CI: 0.681-0.950, P = 0.011), prothrombin time activity (HR = 0.856, 95%CI: 0.751-0.975, P = 0.020) and microvascular invasion (HR = 19.852, 95%CI: 2.203-178.917, P = 0.008). In both training and validation cohorts, 12-month and 36-month prognostic performance of the SSCLIP were significantly better than those of the original CLIP, model of end-stage liver disease-based CLIP, Okuda and Child-Turcotte-Pugh score (all P < 0.05). The stratification of risk levels of the SSCLIP showed an enhanced ability to differentiate patients with different outcomes. CONCLUSIONS: A novel SSCLIP to predict survival of HCC patients who received CLR based on objective parameters may provide a refined, useful prognosis algorithm.