Expression and clinical significance of circBIRC6 and circCORO1C in patients with non-M3 acute myeloid leukemia

Circular RNAs (circRNAs) have emerged as important regulators of gene expression and may contribute to hematopoietic differentiation and leukemogenesis. Although circBIRC6 and circCORO1C have been implicated in stemness-related processes and tumor progression, their clinical relevance in non-M3 acute myeloid leukemia (AML) remains poorly characterized. This study investigated the expression and potential clinical significance of circBIRC6 and circCORO1C in patients with non-M3 AML. Bone marrow samples were obtained from 63 patients with newly diagnosed non-M3 AML and 47 healthy controls. The expression levels of circBIRC6 and circCORO1C were quantified using quantitative reverse transcription-polymerase chain reaction (RT-qPCR). Associations between circRNA expression and clinicopathological characteristics, complete remission (CR), overall survival (OS), and relapse-free survival (RFS) were evaluated. Receiver operating characteristic (ROC) curve analysis was performed to assess the discriminatory ability of the two circRNAs between AML patients and healthy controls. Both circCORO1C and circBIRC6 were significantly upregulated in non-M3 AML compared with healthy controls, with approximately 2.02-fold (P = 0.0008) and 1.91-fold (P = 0.006) higher expression, respectively. Higher circCORO1C expression was associated with AML-M2 and AML-M4/M5 subtypes, whereas higher circBIRC6 expression was associated with unfavorable cytogenetic risk. Patients with higher expression of either circRNA had higher peripheral white blood cell counts. Higher circCORO1C expression was associated with a lower CR rate, whereas the association between circBIRC6 expression and CR did not reach statistical significance (P = 0.051). Higher expression of both circRNAs was associated with shorter OS and RFS. ROC analysis showed modest discriminatory ability for circCORO1C (AUC = 0.68) and circBIRC6 (AUC = 0.65). circCORO1C and circBIRC6 are moderately upregulated in non-M3 AML and are associated with selected disease characteristics and adverse clinical outcomes. Their modest discriminatory performance and the absence of multivariable prognostic analyses indicate that these findings should be considered exploratory, and that independent prognostic effects cannot be established from the present data. Larger, independent multicenter cohorts incorporating appropriate multivariable analyses, molecular characterization, and functional validation are required to determine whether these circRNAs have clinically useful diagnostic or prognostic value.