Prognostic Relevance of Structural Maintenance of Chromosomes 4 Overexpression in Pediatric Acute Lymphoblastic...

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. Abnormal expression of structural maintenance of chromosomes (SMC) 4 has been observed in multiple tumors and plays a vital role in cancer development. However, the association between SMC4 expression and clinical characteristics in Chinese childhood patients with ALL is unknown. Thus, this study aimed to investigate the relationship between SMC4 expression and clinical features and prognosis in these patients.

Real-time quantitative polymerase chain reaction (PCR) was performed to detect the expression of SMC4 in Chinese pediatric ALL patients and in patients achieving complete remission (CR). Then, the relationships between SMC4 expression and clinical features, such as gender, age, white blood cell (WBC) count, French-American-British (FAB) classification, immunophenotype, fusion gene, prednisone response, and minimal residual disease (MRD) were determined. Furthermore, survival and prognostic factor analyses were carried out to examine the prognostic value of SMC4 expression.

The expression level of SMC4 was significantly higher in bone morrow cells of newly diagnosed pediatric ALL patients than in those of healthy controls (p = 0.006), especially in B-cell precursor ALL (BCP ALL). Moreover, SMC4 expression was correlated with different clinical parameters. Furthermore, a decrease of SMC4 expression was detected in BCP ALL patients achieving CR. The high SMC4 expression group had both worse event-free survival rate and poorer overall survival rate. However, multivariate analysis showed that SMC4 expression was not an independently predictive factor of BCP ALL outcome.

These results revealed that SMC4 expression in BM was associated with various clinical outcomes in pediatric patients with ALL, although it was not an independent outcome factor.