Cancer Science & Therapy

Biography

Biography: Mengying Liu

Abstract

Statement of the Problem: BCR-ABL p190 (e1a2) is expressed in 20-30% of Acute Lymphoblastic Leukemia (ALL) and 1-2% of Chronic Myeloid Leukemia (CML)^1,2. The co-expression of p190 and p210 is rare in both CML and ALL^1,2. Xpert^® BCR-ABL Ultra p190, an automated cartridge-based test for measuring BCR-ABL p190 transcript level, is standardized to quantify the amount of BCR-ABL p190 relative to ABL1 control gene based on delta Ct in peripheral blood of patients³. Since BCR-ABL p190 level is crucial for risk stratification and treatment decisions in ALL⁴ as well as diagnosis and continuous therapeutic monitoring in CML⁵, it can be useful to obtain the copy number (CN) of BCR-ABL p190. The purpose of this study is to establish a BCR-ABL p190 CN estimator with known CN of e1a2-ABL IVT-RNA as well as to compare %BCR-ABL p190/ABL1 reporting between delta Ct-based and CN-based methods. Methodology & Theoretical Orientation: Nine levels of e1a2-ABL IVT-RNA as well as two lots of Xpert^® BCR-ABL Ultra p190 tests were used to generate standard curves for CN and %CN reporting. BCR-ABL p190 contrived samples and ALL clinical samples containing the BCR-ABL p190 transcript were examined to evaluate the CN and %CN between two lots of the Xpert^® BCR-ABL Ultra p190 tests and to compare the delta Ct-based and CN-based methods for reporting %BCR-ABL p190/ABL1. Findings: Linearity was demonstrated in Ct vs CN input for BCR-ABL p190 (R²>0.99) and ABL1 (R²>0.98). Less than 1.35-fold difference was exhibited for CN and %CN across two different lots. Less than 2-fold difference was observed in %BCR-ABL p190/ABL1 reporting between delta Ct-based and CN-based approaches. Conclusion & Significance: A BCR-ABL p190 copy number estimator for Xpert^® BCR-ABL Ultra p190 test was established, which will provide helpful information for diagnosis and prognosis of diseases relating to BCR-ABL