VEGFR2 expressions in Th1 and CD8+ cytotoxic T lymphocytes (CTL) in colon cancer patients.

Abstract

e15535 Background: VEGF receptors have an important role for inhibiting adaptive immun response in colon cancer. Therefore, we analyzed VEGF receptors in circulating T cell subsets according to stage in colon cancer patients. Methods: The prospective study group consisted of 50 patients with histologically confirmed colon cancer and 30 person without any cancer history as a control group. Peripheral blood specimens were collected from the patients after the diagnosis before inducing chemotherapy and radiotherapy. Patients with active infections or autoimmune disorders, who were treated with steroids and antibiotics in the last four weeks before the study enrollment were excluded from the study group. VEGFR2 expressions in circulating T cell subsets (Th1, Th2, Th17, CTL) were analyzed by flow cyctometry. Results: Age and gender were not different between the all study groups. Mean circulating CD4+ folicullar cells were less in colon cancer patients (9.54%±3.99) than the control group (12.03%±4.34), (p < 0.01). Mean circulating CD8+ follicular cells were higher in metastatic colon cancer (n = 26) 2.48% ± 1.68, than the non-metastatic colon cancer patients (n = 24) 1.63% ± 1.37, (p = 0.02). Mean VEGFR2 expressions in Th1 cells were higher in colon cancer patients 248.8 (Mean Flourescein intensity-MFI) than the control group 224.6, (P = 0.006). Mean VEGFR2 expressions in CTL were higher in colon cancer patients (381.8) than the control group (284.7), (p < 0.001). PD-1 expressions were not different between the colon cancer patients and the control group in all circulating T cell subsets. Mean VEGFR2 expressions in Th17 cells were higher non-metastatic colon cancer patients than the metastatic colon cancer patients (326.5 and 268.4 MFI, respectively, p = 0.02). Conclusions: VEGFR2 expressions are increased in circulating Th1 and CTL subsets in colon cancer patients. Whereas PD-1 expressions were not different in circulating T cell subsets than the control. VEGFRs may play an important role for the inhibition of circulating T cell subsets in colon cancer.