487-P: The Activation of mTORC1 in Leukocytes of Patients with Cancer and Diabetes

Aim: mTOR/p70S6K1 play an important role in the pathogenesis of cancer and diabetes. Macrophages and lymphocytes are involved in the pathogenesis of diabetes, diabetic atherosclerosis, formation of insulin resistance as well as immune response to cancer and tumor maintenance. Thus, the aim was to study the mTORC1 activation by determining the phosphorylation of PRAS40 and p70S6K1 in leukocytes of patients with type 2 diabetes and cancer.

Materials and Methods: The following groups were studied: control group - healthy people, representative by age (n=6), patients with type 2 diabetes (n=12), cancer patients (n=15) and patients with both cancer and diabetes (n=7). For determinations of phospho-PRAS40 (Thr246) and phospho-p70S6K1 (Thr389) amounts ELISA kits КНО0421 and 85-86053 (Invitrogen) respectively were used. The protein concentration in the lysate was determined using BCA protein assay kit. The measurements were carried out on a microplate reader at a wavelength of 450 nm.

Results: The amounts of phosphorylated PRAS40 and p70S6K1 significantly increase in leukocytes of patients with type 2 diabetes and cancer, which indicates the mTORC1 activation. The number of phospho-PRAS40-positive samples in patients with diabetes was 83.3%, and in patients with cancer - 66.7%. The decrease in the amount of phospho-PRAS40 in leukocytes of the patients group both with cancer and diabetes was observed.

Conclusions: Thus, phosphorylation of PRAS40 is generally consistent with the activation of mTORC1, as measured by phosphorylation of p70S6K1. The changes in the activity of mTOR/S6K in severe chronic diseases can be systemic, and the study of the status of these kinases in leukocytes perhaps could be useful for diagnostic and prognostic purposes.