Antineoplastic Combined Chemotherapy Protocols/pharmacology; Carcinoma, Squamous Cell/metabolism; Crotoxin/pharmacology; Lung Neoplasms/metabolism; Protein Kinase Inhibitors/pharmacology; Animals; Antineoplastic Combined Chemotherapy Protocols/administration & dosage; Apoptosis/drug effects; Carcinoma, Squamous Cell/drug therapy; Caspase 3/metabolism; Cell Cycle/drug effects; Cell Line, Tumor; Crotoxin/administration & dosage; Drug Synergism; Enzyme Activation/drug effects; ErbB Receptors/antagonists & inhibitors; ErbB Receptors/metabolism; Female; Gefitinib; Humans; JNK Mitogen-Activated Protein Kinases/metabolism; Lung Neoplasms/drug therapy; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphorylation/drug effects; Protein Kinase Inhibitors/administration & dosage; Proto-Oncogene Proteins c-bcl-2/metabolism; Quinazolines/administration & dosage; Quinazolines/pharmacology; Xenograft Model Antitumor Assays