Objectives: Small cell lung cancer (SCLC) patients of all stages are treated with etoposide and cisplatin or carboplatin with or without surgery or chest radiotherapy. Initial response rates are ≥70% however the majority of patients relapse and are resistant to additional therapies due to pan-resistance to these salvage therapies. Therefore, new treatments are urgently needed.
View Article and Find Full Text PDFThe emergence of EGFR inhibitors such as gefitinib, erlotinib, and osimertinib has provided novel treatment opportunities in EGFR-driven non-small cell lung cancer (NSCLC). However, most patients with EGFR-driven cancers treated with these inhibitors eventually relapse. Recent efforts have identified the canonical Wnt pathway as a mechanism of protection from EGFR inhibition and that inhibiting tankyrase, a key player in this pathway, is a potential therapeutic strategy for the treatment of EGFR-driven tumors.
View Article and Find Full Text PDFSmall-cell lung cancer (SCLC) cells have rapid proliferation, universal Rb inactivation, and high rates of MYC family amplification, making aurora kinase inhibition a natural target. Preclinical studies have demonstrated activity for Aurora A and pan-Aurora inhibitors with some relationship to MYC family expression. A clinical trial showed activity for an Aurora kinase A inhibitor, but no biomarkers were evaluated.
View Article and Find Full Text PDFPurpose: FGFR1 gene copy number (GCN) is being evaluated as a biomarker for FGFR tyrosine kinase inhibitor (TKI) response in squamous cell lung cancers (SCC). The exclusive use of FGFR1 GCN for predicting FGFR TKI sensitivity assumes increased GCN is the only mechanism for biologically relevant increases in FGFR1 signaling. Herein, we tested whether FGFR1 mRNA and protein expression may serve as better biomarkers of FGFR TKI sensitivity in lung cancer.
View Article and Find Full Text PDFLung cancer is the leading cause of death worldwide. Adenocarcinomas, the most common histologic subtype of non-small cell lung cancer (NSCLC), are frequently associated with activating mutations in the epidermal growth factor receptor (EGFR) gene. Although these patients often respond clinically to the EGFR tyrosine kinase inhibitors erlotinib and gefitinib, relapse inevitably occurs, suggesting the development of escape mechanisms that promote cell survival.
View Article and Find Full Text PDFDespite initial and sometimes dramatic responses of specific NSCLC tumors to EGFR TKIs, nearly all will develop resistance and relapse. Gene expression analysis of NSCLC cell lines treated with the EGFR TKI, gefitinib, revealed increased levels of FGFR2 and FGFR3 mRNA. Analysis of gefitinib action on a larger panel of NSCLC cell lines verified that FGFR2 and FGFR3 expression is increased at the mRNA and protein level in NSCLC cell lines in which the EGFR is dominant for growth signaling, but not in cell lines where EGFR signaling is absent.
View Article and Find Full Text PDFThe epithelial to mesenchymal transition (EMT) is a developmental process enabling epithelial cells to gain a migratory mesenchymal phenotype. In cancer, this process contributes to metastases; however the regulatory signals and mechanistic details are not fully elucidated. Here, we sought to identify the subset of genes regulated in lung cancer by ZEB1, an E-box transcriptional repressor known to induce EMT.
View Article and Find Full Text PDFDespite widespread expression of epidermal growth factor (EGF) receptors (EGFRs) and EGF family ligands in non-small-cell lung cancer (NSCLC), EGFR-specific tyrosine kinase inhibitors (TKIs) such as gefitinib exhibit limited activity in this cancer. We propose that autocrine growth signaling pathways distinct from EGFR are active in NSCLC cells. To this end, gene expression profiling revealed frequent coexpression of specific fibroblast growth factors (FGFs) and FGF receptors (FGFRs) in NSCLC cell lines.
View Article and Find Full Text PDFThe modest response of patients with head and neck squamous cell carcinoma (HNSCC) and non-small cell lung carcinoma (NSCLC) to epithelial growth factor receptor tyrosine kinase inhibitors such as gefitinib and erlotinib indicates the need for the development of biomarkers to predict response. We determined gefitinib sensitivity in a panel of HNSCC cell lines by a 5-day 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and confirmed these responses with analysis of downstream signaling by immunoblotting and cell cycle arrest. Basal gene expression profiles were then determined by microarray analysis and correlated with gefitinib response.
View Article and Find Full Text PDFPurpose: Recognition that the epidermal growth factor receptor (EGFR) was a therapeutic target in non-small cell lung cancer (NSCLC) and other cancers led to development of the small-molecule receptor tyrosine kinase inhibitors gefitinib and erlotinib. Clinical trials established that EGFR tyrosine kinase inhibitors produced objective responses in a minority of NSCLC patients. We examined the sensitivity of 23 NSCLC lines with wild-type or mutated EGFR to gefitinib to determine genes/proteins related to sensitivity, including EGFR and HER2 cell surface expression, phosphorylated EGFR expression, EGFR gene copy number, and EGFR mutational status.
View Article and Find Full Text PDFTyrosine kinase inhibitors (TKI) of the epidermal growth factor receptor (EGFR) produce objective responses in a minority of patients with advanced-stage non-small cell lung cancer (NSCLC), and about half of all treated patients progress within 6 weeks of instituting therapy. Because the target of these agents is known, it should be possible to develop biological predictors of response, but EGFR protein levels have not been proven useful as a predictor of TKI response in patients and the mechanism of primary resistance is unclear. We used microarray gene expression profiling to uncover a pattern of gene expression associated with sensitivity to EGFR-TKIs by comparing NSCLC cell lines that were either highly sensitive or highly resistant to gefitinib.
View Article and Find Full Text PDFThe epidermal growth factor receptor is overexpressed in a majority of non-small cell lung cancers and has been associated with a poor prognosis. Preclinical studies have shown that ZD1839, an oral anilinoquinazoline, targets the epidermal growth factor receptor-associated tyrosine kinase, reversibly inhibiting critical downstream signaling and resulting in cancer cell growth arrest. Potent antitumor effects have been observed in human lung tumor xenograft models.
View Article and Find Full Text PDFLung cancer, like many other epithelial malignancies, is thought to be the outcome of genetic and epigenetic changes that result in a constellation of phenotypic abnormalities in bronchial epithelium. These include morphologic epithelial dysplasia, angiogenesis, increased proliferative rate, and changes in expression of cell surface proteins, particularly overexpression of epidermal growth factor receptor (EGFR) family proteins. The EFGR family is a group of four structurally similar tyrosine kinases (EGFR, HER2/neu, ErbB-3, and ErbB-4) that dimerize on binding with a number of ligands, including EGF and transforming growth factor alpha.
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