crizotinib and Carcinoma--Lewis-Lung

Non-small cell lung cancer (NSCLC) patients with chromosomal rearrangements of the anaplastic lymphoma kinase gene (ALK) are sensitive to the tyrosine kinase inhibitor crizotinib. We aimed to investigate the effects of combined radiotherapy and crizotinib in ALK-positive vs. wild type NSCLC models.. Clonogenic survival, proliferation and apoptosis of cells exposed to crizotinib and radiotherapy (photon and carbon ions) were evaluated in ALK mutation positive (ALK+; H3122) and negative (ALK-; A549 and LLC) NSCLC lines. The syngeneic mouse (LLC) and human (H3122) xenograft tumor models were further studied in vivo. Tumor growth kinetics, microvascular density (MVD), perfusion and proliferation were assessed.. Crizotinib exerted potent and selective anti-proliferative and pro-apoptotic effects in ALK+ H3122 cells which were augmented by radiotherapy. The synergistic effect of this combination in ALK+ NSCLC was confirmed by isobologram analysis. Crizotinib also sensitized H3122 cells to particle therapy with carbon ions. In H3122 xenografts, dual combination was most effective in reducing tumor proliferation, MVD and perfusion. In contrast, in the LLC model, crizotinib led only to a transient tumor growth inhibition and combined treatment was inferior to radiotherapy alone.. Crizotinib elicits beneficial effects in combination with radiotherapy only in ALK-positive NSCLC.

Topics: Animals; Apoptosis; Carcinoma, Lewis Lung; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Chemoradiotherapy; Crizotinib; Drug Synergism; Female; Humans; Lung Neoplasms; Mice; Mice, Inbred C57BL; Oncogene Proteins, Fusion; Protein Kinase Inhibitors; Pyrazoles; Pyridines; Random Allocation; Xenograft Model Antitumor Assays

Lung cancer accounts for 13% (1.6 million) of the total cases and 18% (1.4 million) of the deaths in 2008. Crizotinib (PF-02341066) is identified as an ATP competitive small-molecular inhibitor for anaplastic lymphoma kinase (ALK). The US Food and Drug Administration (FDA) approved crizotinib to be used for the treatment of patients with locally advanced or metastatic ALK-positive NSCLC in 2011. In the present study, the side population (SP) and main population (MP) cells were obtained from Lewis lung carcinoma cells (LLC) and analyzed by DNA dye (Hoechst 33342) and flow cytometry. LLC SP and MP cells were confirmed as no ALK fusion gene by fluorescence in situ hybridization. The effects of crizotinib on LLC SP and MP cells both in vivo and in vitro were identified. Our results indicate that crizotinib can induce apoptosis and G1 phase arrest in LLC MP cells. Crizotinib used in combination with verapamil can inhibit proliferation of LLC SP cells. Moreover, crizotinib decreased tumor size and weight and inhibited angiogenesis in established xenografted tumors. To analyze the signaling pathway involved, computer simulation, Affymetrix microarray analysis and western blot analysis were performed. In these assays, crizotinib was found to dock into Smad3 and activate the Smad signaling pathway. Overall, these studies demonstrate the antitumor activity of crizotinib in LLC cell line, and provide a novel use for crizotinib.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Calcium Channel Blockers; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Proliferation; Crizotinib; G1 Phase Cell Cycle Checkpoints; Humans; Lung Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Neovascularization, Pathologic; Protein Kinase Inhibitors; Pyrazoles; Pyridines; Signal Transduction; Smad3 Protein; Smad4 Protein; Verapamil; Xenograft Model Antitumor Assays