OBJECTIVETo study the expression of β-integrin family members in children with T-cell acute lymphoblastic leukemia (T-ALL) and their significance.

METHODSQuantitative real-time PCR analyses were performed to assess the expression levels of β-integrin family members in bone marrow samples from 22 children with newly-diagnosed T-ALL and 21 controls (16 children with non-malignant hematologic disease and 5 healthy donors with bone marrow transplantation). Jurkat cells were treated with integrin inhibitor arginine-glycine-aspartate (Arg-Gly-Asp, RGD) peptide. The cell viability and apoptosis rate were determined by CCK8 assay and flow cytometry respectively.

RESULTSThe mRNA levels of integrins β, β, and βwere significantly lower in children with T-ALL than in controls (P<0.05). In T-ALL patients, high integrin βexpression was associated with lower white blood cell counts (<100×10/L), minimal residual disease (MRD) positivity, and day 33 bone marrow negative remission (P<0.05). In T-ALL patients, higher integrin βexpression was associated with relapse of T-ALL (P<0.05). Based on survival curve analysis, higher integrin βexpression was related to lower event-free survival and overall survival rates. RGD peptide treatment inhibited the proliferation of Jurkat cells and increased their apoptosis rate (P<0.05).

CONCLUSIONSβ-Integrin may play a role in the occurrence and development of T-ALL by affecting cell proliferation and apoptosis. The expression of integrin β5 is closely related to the risk of relapse of T-ALL. The expression of integrin β3 is closely related the treatment response and prognosis of T-ALL.