The Role of Mitogen-Activated Protein Kinase Kinase (MEK) in Hepatocellular Carcinoma

The mitogen-activated protein kinase kinase (MEK) pathway is a key regulator of cell proliferation, survival, and differentiation, and its dysregulation is closely linked to hepatocellular carcinoma (HCC) development. This retrospective study aimed to investigate the expression of MEK in HCC, its association with clinicopathological features, and prognostic significance. A total of 260 HCC patients who underwent surgical resection at our institution from 2016 - 2021 were included. MEK expression in tumor and adjacent non-tumor tissues was detected by immunohistochemistry. High MEK expression in tumor tissues was significantly associated with larger tumor size (p = 0.003), higher histological grade (p = 0.01), microvascular invasion (p = 0.001), and elevated alpha-fetoprotein (AFP) levels (p = 0.005). Multivariate Cox regression analysis identified high MEK expression as an independent predictor of poor overall survival (hazard ratio [HR] = 2.2, 95% confidence interval [CI]: 1.4 - 3.5, p < 0.001) and recurrence-free survival (HR = 2.1, 95% CI: 1.3 - 3.3, p = 0.002). These findings highlight the critical role of MEK in HCC progression and suggest its potential as a prognostic biomarker and therapeutic target.