West Asia Organization for Cancer Prevention (WAOCP), APOCP's West Asia Chapter. Asian Pacific Journal of Cancer Prevention 1513-7368 23 5 2022 05 01 Relationship between Bax and Bcl-2 Protein Expression and Outcome of Induction Phase Chemotherapy in Pediatric Acute Lymphoblastic Leukemia 1679 1685 90119 10.31557/APJCP.2022.23.5.1679 EN Andi Cahyadi Hematology Oncology Division, Department of Child Health, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. 0000-0002-4523-3663 I Dewa Gede Ugrasena Hematology Oncology Division, Department of Child Health, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. 0000-0002-0458-7801 Mia Ratwita Andarsini Hematology Oncology Division, Department of Child Health, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. 0000-0003-1431-5137 Maria Christina Shanty Larasati Hematology Oncology Division, Department of Child Health, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. 0000-0003-1316-9246 Aryati Aryati Department of Clinical Pathology, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. 0000-0002-9383-6354 Diah Kusuma Arumsari Hematology Oncology Division, Department of Child Health, Faculty of Medicine, Universitas Airlangga/Dr. Soetomo General Academic Hospital, Surabaya, Indonesia. Journal Article 2021 12 27 Background: Overexpression of the antiapoptotic protein Bcl-2 causes apoptosis to stop and conversely the increased expression of the proapoptotic protein Bax makes lymphoblasts easy to destroy. The Bax/Bcl-2 ratio plays a role in the balance of apoptosis, immortality, resistance, and outcome of chemotherapy. We analyzed the relationship between the Bax/BCl-2 ratio and the outcome of induction phase chemotherapy in pediatric Acute Lymphoblastic Leukemia (ALL). Methods: This research was conducted with a prospective observational study on pediatric ALL aged 1-18 years who were newly diagnosed based on bone marrow aspiration (morphology and immunophenotyping) at Dr. Soetomo General Hospital, Surabaya on October 2020 to March 2021. Expression of Bcl-2, Bax, and Bax/Bcl-2 protein ratio was measured by the flow cytometry method from lymphoblast on bone marrow aspirate samples before and after induction phase chemotherapy according to the 2018 Childhood ALL Indonesian Protocol. The outcomes evaluated were survival and remission rate (lymphoblasts in the bone marrow less than 5%). We used the Mann-Whitney U test and Wilcoxon Signed Rank test to analyze the differences between protein expression with p<0.05 for a two-tailed test. Results: We included 17/26 pediatric ALL, consisting of 88% male, 94% LLA-L1, 76% B cell ALL and 24% T cell ALL. Mean expression of Bax, Bcl-2, and Bax/Bcl-2 protein ratio before chemotherapy among pediatric ALL who alive (N=11) and dead (N=6) were not significantly different (p>0.05). All children who completed the induction phase of chemotherapy went into remission. Bax and Bcl-2 expression before and after chemotherapy showed no difference (p>0.05). The Bax/Bcl-2 ratio increased from 1.74(SD 1.846) to 6.17(4.139) with p=0.021. Conclusion: Expression of Bax, Bcl-2, and Bax/Bcl-2 protein ratio at the beginning of diagnosis did not affect the survival of pediatric ALL after the induction phase of chemotherapy. The Bax/Bcl-2 protein ratio increased 3.5 times in pediatric ALL with remission outcomes, indicating proapoptotic dominance. https://journal.waocp.org/article_90119_d0a1ddd1a1a44062338a1bb5a8473339.pdf