Pro-apoptotic and mitochondria-disrupting effects of 4-methylthiazole in K562 leukemia cells: A mechanistic investigation

Abstract

Thiazole derivatives have garnered attention for their anticancer potential. This study investigates the antileukemic effects of 4-methylthiazole on K562 chronic myeloid leukemia (CML) cells, focusing on apoptosis induction and mitochondrial dysfunction. Cell viability was assessed using MTS assays; apoptosis and necrosis were analyzed via Annexin V/PI staining and flow cytometry; mitochondrial membrane potential changes were evaluated with JC-1 dye; gene expression levels were measured by qRT-PCR; and levels of apoptosis- and cytokine-related proteins were quantified using ELISA. Treatment with 4-methylthiazole led to selective cytotoxicity in K562 cells while sparing healthy peripheral blood mononuclear cells (PBMNCs). Apoptotic induction was evidenced by Caspase-3 (CASP-3) activation, Cytochrome-C (CYT-C), release, and mitochondrial depolarization. Gene expression analysis showed upregulation of pro-apoptotic markers such as TP53 (tumor suppressor protein 53), BAX and BAK (pro-apoptotic Bcl-2 family proteins), while upregulation of CASP3 (caspase-3) expression was not statistically significant. Conversely, levels of GPX4 (glutathione peroxidase 4, involved in oxidative stress protection) remained unchanged, indicating an apoptosis mechanism independent of oxidative stress. Additionally, SEMA3A (Semaphorin 3 A, involved in tumor progression and cell signaling) was significantly downregulated. Cytokine profiling revealed a dose-dependent modulation of IL-6, while TNF-α and IL-10 levels remained unaffected. These findings suggest that 4-methylthiazole induces apoptosis through mitochondrial pathways, affects cytokine signaling, and selectively targets leukemia cells, supporting its potential as a therapeutic candidate for CML treatment.