OSTEOPONTIN-A IS ASSOCIATED WITH T-ALL PROGNOSTIC FEATURES

INTRODUCTION AND OBJECTIVES: T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy characterized by an oncogenic process in T-lymphocyte precursors. Resistance and relapse are common, despite improved treatment efficacy. Therefore, it is essential to search for new biomarkers related to T-ALL malignancy processes. In T-ALL, osteopontin (OPN) serum levels are distinguished from healthy samples. Moreover, OPN primary transcript is subject to alternative splicing, generating five isoforms (OPN-SI), which act in a tissue and tumor-specific way. However, OPN-SI expression patterns and functions in T-ALL had not been explored. Herein, we aimed to characterize the expression of OPN-SI and their associations with different prognostic factors in T-ALL patients. MATERIAL AND METHODS: The analyses were performed using the virtual database TARGET, and statistical analysis and graphical representations using the software GraphPad Prism 8. RESULTS AND CONCLUSION: Among the OPN-SI, each isoform presented a different median of expression. Notably, OPNa is the most frequently expressed (31.52%) and presents the highest median expression levels (0.06 TPM) among patients with T-ALL in this cohort. In T-ALL patient subgroups with early T cell precursor (ETP) immunophenotype and presenting blasts at the pre-cortical stage, OPNa splice variant displayed the highest expression levels (0.15 TPM and 0.04 TPM, respectively), suggesting its importance for maintenance of stemness potential in T-ALL. In conclusion, the OPN-SI presented different expression profiles in the T-ALL patients. Among the five analysed OPN-SI, OPNa  transcriptional levels were associated with worse prognosis features.