the in vitro activity was not reflected in their in vivo potency

Crizotinib injection of irinotecan produced the most significant inhibition of cecal tumor and completely inhibited metastasis to regional lymph nodes. In mice injected with SW620CE2 nontargeting shRNA tumor cells, control mice had the largest tumors, and 6 of 9 mice had metastasis in the regional lymph nodes. Oral administration of PKI166 significantly reduced the weight of the cecal tumors and decreased the incidence of lymph node metastasis to 2 of 9 mice. Intraperitoneal injection of irinotecan also inhibited cecal tumor growth. Oral administration of PKI166 and i. p. injection of irinotecan produced the most significant inhibition of cecal tumor growth and completely inhibited lymph node metastasis. The obtained with the SW620CE nontargeting shRNA were therefore similar to that obtained with the SW620CE2 WT tumors. In mice injected with SW620CE2 TGF shRNA tumor cells, the control group had the largest cecal tumors, and 3 of 9 mice had lymph node metastasis. Oral administration of PKI166 did not produce significant changes in tumor weight. Treatment with irinotecan Immune system alone inhibited tumor growth. The weight of cecal tumors in mice treated with the combination of oral PKI166 and i. p. irinotecan was comparable to mice treated with only irinotecan. The incidence of lymph node metastasis was higher in mice with SW620CE2 WT and SW620CE nontargeting shRNA than in mice with SW620CE2 TGF shRNA cecal tumors. Immunohistochemical Analysis Next, we determined the expression of TGF, EGF, EGFR, and phosphorylated EGFR in tumors by immunohistochemical analysis. SW620CE2 WT and SW620CE nontargeting shRNA tumors expressed high levels of TGF, whereas the SW620CE2 TGF shRNA tumor did not. Because the immunohistochemistry was carried out on cells transfected with the TGF shRNA at least 12 weeks before the assay, the absence of TGF expression verified the stability of the transfection. Oprozomib None of the tumors expressed EGF. Dual localization of CD31 and EGFR or pEGFR confirmed that tumor cells in all three colon carcinoma groups did not express the EGFR. In all groups, tumor associated endothelial cells expressed the EGFR. In the SW620CE WT tumors and SW620CE nontargeting shRNA treated with PKI166 or PKI166 plus irinotecan, the EGFR was not phosphorylated. In the SW620CE2 TGF shRNA tumor, tumor associated endothelial cells expressed EGFR that was not phosphorylated. Cell Proliferation, Apoptosis, and MVD in Cecal Tumors Cell proliferation was evaluated by staining for Ki 67. In SW620CE2 WT tumors, the median number of Ki 67 LI of control group was 17. Treatment with irinotecan alone or PKI166 alone significantly decreased the number of Ki 67 LI. Treatment with both PKI166 and irinotecan produced the most significant decrease in cell proliferation. In SW620CE2 nontargeting shRNA tumors, the median number of Ki 67 LI of control group was 19. Treatment with irinotecan alone or PKI166 alone significantly decreased the number of Ki 67 LI.