Antileukemic Potential of Sodium Caseinate in Cytarabine-Resistant HL60-CR50 Human Leukemia Cells

Chemoresistance is the leading cause of mortality in cancer patients. The poor clinical prognosis and limited therapeutic options for acute myeloid leukemia (AML) patients demand the development of new therapeutic strategies capable of overcoming chemoresistance and avoiding toxic side effects in normal cells. Sodium caseinate (SC), a derivative of casein protein found in milk, has demonstrated a dual role: it inhibits the proliferation of several murine AML cell lines while promoting the proliferation of normal hematopoietic cells. Furthermore, we previously showed that SC can modulate the expression of genes associated with chemoresistance in mouse cells. However, its biological effects on cytarabine-resistant human leukemia cells remain unclear. Here, we developed the HL60-CR50 subline, resistant to cytarabine, and investigated the effects of SC. We demonstrated that SC significantly reduced cell proliferation, decreased SIRT1 levels, increased acetylated p53, activated cleaved caspase-3, and enhanced apoptosis in cytarabine-resistant cells. These findings suggest that SC might have potential as a therapeutic adjuvant for AML, providing efficacy in chemoresistant cases compared with cytarabine treatment alone.