Expression of caspase-9 in bone marrow lymphoblasts in children with acute lymphoblastic leukemia

Caspase-9 plays a critical role in mediating apoptosis through various intrinsic pathway triggers within the mitochondria. Failure to respond to apoptotic stimuli in Acute Lymphoblastic Leukemia (ALL) can lead to chemotherapy resistance related to deviations in the caspase pathway in lymphoblasts. This study aims to assess the caspase-9 expression both before and after the induction phase of chemotherapy in children with ALL and its association with several clinical parameters. This prospective study involved pediatric patients aged 1-18 years who were newly diagnosed with ALL and administered induction-phase chemotherapy following the 2018 Indonesian National Protocol for ALL treatment. The expression of caspase-9 was evaluated before and after the induction phase from bone marrow aspirate using flow cytometry. The variance in caspase-9 expression was examined using the Mann-Whitney U test, with p < 0.05 for a two-tailed test was considered statistically significant. Out of the 37 pediatric ALL cases, 17 met the specified criteria. The median expression of caspase-9 before chemotherapy in dead children was higher (p = 0.182). The median expression before chemotherapy increased after the induction phase of chemotherapy (p = 0.561). The caspase-9 expression was low in children with hepatomegaly and splenomegaly (p = 0.015, p = 0.009). Expression of caspase-9 was elevated after chemotherapy and higher in surviving children than in dead children. Caspase-9 expression before chemotherapy was low in children with hepatomegaly and splenomegaly.