Chronic Lympocytic Leukemia (CLL): The role of Sphingosine Kinases (SK) in the activation, proliferation and survival of the leukemic clone

ALMEJÚN MARÍA BELÉN; BORGE MERCEDES; COLADO ANA; PODAZA ENRIQUE; RISNIK DENISE; DE BRASI CARLOS DANIEL; OPPEZZO PABLO; CABREJO MARÍA; FERNÁNDEZ GRECCO HORACIO; BEZARES RAIMUNDO F; CRANCO SANTIAGO; BURGOS RUBEN; SÁNCHEZ-ÁVALOS JULIO CÉSAR; GIORDANO MIRTA; GAMBERALE ROMINA

CABA

Congreso; I Meeting LASID, FAIC, SAI 2015; 2015

Background: Leukemic B-cells from CLL patients survive and proliferate within lymphoid tissues where the supportive microenvironment favors their accumulation. We have previously reported that CLL activation reduces the expression of the main receptor for sphingosine-1-phosphate (S1P), a bioactive phospholipid that participates in lymphocyte egress from lymphoid tissues. S1P also favors cell growth and survival, through receptor independent intracellular mechanisms, and is generated by sphingosine kinases (SK1/2) and degraded by S1P lyases (S1PL). The aim of our study was to evaluate the role of SK/S1P/S1PL pathway in the proliferation and survival of CLL-cells. Results and Methods: We measured SK and S1PL expression by qRT-PCR on purified B-cells from CLL patients (n=22) and aged-matched healthy donors (n=9), and found that CLL-cells express a higher SK1/S1PL ratio (p