[High MYO1B expression promotes proliferation, migration and invasion of gastric cancer cells and is associated with poor patient prognosis].

[OBJECTIVES] To analyze MYO1B expression in gastric cancer, its association with long-term prognosis and its role in regulating biological behaviors of gastric cancer cells.

[METHODS] We analyzed MYO1B expression in gastric cancer and its correlation with tumor grade, tumor stage, and patient survival using the Cancer Public Database. We also examined MYO1B expression with immunohistochemistry in gastric cancer and paired adjacent tissues from 105 patients receiving radical surgery and analyzed its correlation with cancer progression and postoperative 5-year survival of the patients. GO and KEGG enrichment analyses were used to explore the biological functions of MYO1B and the key pathways. In cultured gastric cancer cells, we examined the changes in cell proliferation, migration and invasion following MYO1B overexpression and knockdown.

[RESULTS] Data from the Cancer Public Database showed that MYO1B expression was significantly higher in gastric cancer tissues than in normal tissues with strong correlations with tumor grade, stage and patient prognosis (<0.05). In the clinical tissue samples, MYO1B was significantly overexpressed in gastric cancer tissues in positive correlation with Ki67 expression (=0.689, <0.05) and the parameters indicative of gastric cancer progression (CEA ≥5 μg/L, CA19-9 ≥37 kU/L, G3-4, T3-4, and N2-3) (<0.05). Kaplan-Meier analysis and multivariate Cox regression analysis suggested that high MYO1B expression was associated with decreased postoperative 5-year survival and was an independent risk factor (: 3.522, 95%: 1.783-6.985, <0.05). MYO1B expression level was a strong predictor of postoperative survival (cut-off value: 3.11, AUC: 0.753, <0.05). GO and KEGG analyses suggested that MYO1B may regulate cell migration and the mTOR signaling pathway. In cultured gastric cancer cells, MYO1B overexpression significantly enhanced cell proliferation, migration, and invasion and promoted the phosphorylation of Akt and mTOR.

[CONCLUSIONS] High MYO1B expression promotes proliferation, migration and invasion of gastric cancer cells and is correlated with poor patient prognosis.