High expression of hematopoietic cell specific Lyn substrate-1 (HS1) predicts poor survival of B-cell chronic lymphocytic leukemia patients.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in adults in western countries. HS1 protein regulates leukemic cell migration and homing, and can indirectly promote disease progression and influence patient survival. The aim of this study was to evaluate HS1 expression in CLL patients in connection with other known prognostic factors and patients' survival. 90 untreated CLL patients were included into the study. The control group consisted of 28 healthy matched people. HS1 detection was performed by western-blotting. Mutational status of IgVH, as well as CD38 and ZAP70 expression was also analyzed. HS1 expression was significantly higher in CLL patients comparing to controls. Positive correlation was shown between HS1 and: age (p=0.0454), Rai stage (p=0.0412), leukocytosis (p=0.0129) and beta-2-microglobulin (p=0.0342). Patients with lymphocyte doubling time shorter or equal to 6 months had higher expression of HS1. Patients with higher HS1 expression had shorter survival than those with lower HS1 expression (p=0.0329). We showed, that high HS1 expression predicts poor survival of chronic lymphocytic leukemia patients.