INSULIN SENSITIVITY AND PATTERNS OF GLUCOSE METABOLISM IN PRIMARY CELL LINES OF BREAST CANCER

Abstract

Aim: to study insulin sensitivity and patterns of glucose metabolism in the primary cell lines of breast cancer (BC). Object and Methods: 14 new primary cell lines obtained from the pleural effusion of BC patients were studied. The molecular subtype of BC was defined immunocytochemically using the monoclonal antibodies against progesterone receptor, estrogen receptor and HER-2/Neu. The cells were cultured with recombinant human insulin in the concentrations up to 5000 ng/ml. The sensitivity to the mitogenic effects of insulin, glucose consumption and lactate production were determined. Results: most obtained cell lines originated from triple-negative BC. The sensitivity to the mitogenic effect of insulin was reduced in the majority of these cell lines and their proliferation was stimulated only when insulin was applied in the excessive concentration (5000 ng/ml). The base-line level of glucose consumption in these cell lines varied significantly. Nevertheless, in most cell lines originating from triple-negative BC, this base-line level was high. The intensity of glucose consumption was not in parallel with lactate production. None of 14 cell lines under study responded to the lowest insulin concentration (20 ng/ml) within the range used. Nevertheless, in most cell lines (except for three triple-negative), insulin stimulated glucose consumption in concentrations of 500 ng/ml or 5000 ng/ml. In all triple-negative cell lines, lactate production calculated as normalized values did not change even upon exposure to the highest of the used concentrations of insulin (5000 ng/ml). Conclusions: the sensitivity to the mitogenic effect of insulin was reduced in the majority of the primary BC cell lines under study. High concentration of insulin stimulates glucose consumption although lactate production was not affected.