In non-small cell lung cancer (NSCLC), activating mutations in the epidermal growth factor receptor (EGFR) induce sensitivity to EGFR tyrosine kinase inhibitors. Despite impressive clinical responses, patients ultimately relapse as a reservoir of drug-tolerant cells persist, which ultimately leads to acquired resistance mechanisms. We performed an unbiased high-throughput siRNA screen to identify proteins that abrogate the response of EGFR-mutant NSCLC to EGFR-targeted therapy.
View Article and Find Full Text PDFTwo out of 41 non-small cell lung cancer patients enrolled in a clinical study were found with a somatic CRAF mutation in their tumor, namely CRAF and CRAF. To our knowledge, both mutations are novel in lung cancer and CRAF has not been previously reported in cancer. Expression of CRAF in HEK293T cells and BEAS-2B lung epithelial cells led to increased ERK pathway activation in a dimer-dependent manner, accompanied with loss of CRAF phosphorylation at the negative regulatory S259 residue.
View Article and Find Full Text PDFA large fraction of somatic driver BRAF mutations in lung cancer are non-V600 and impaired-kinase. Non-V600 BRAF mutations predict sensitivity to combination of a type I RAF inhibitor, Dabrafenib, and a MEK inhibitor, Trametinib. Singly, Dabrafenib only weakly suppresses mutant BRAF-induced ERK signaling and can induce ERK paradoxical activation in CRAF-overexpressing cells.
View Article and Find Full Text PDFApproximately half of BRAF-mutated Non-small cell lung cancers (NSCLCs) harbor a non-V600 BRAF mutation, accounting for ∼40,000 annual deaths worldwide. Recent studies have revealed the benefits of combined targeted therapy with a RAF-inhibitor (Dabrafenib) and a MEK-inhibitor (Trametinib) in treating V600 BRAF mutant cancers, including NSCLC. In contrast, sensitivity of non-V600 BRAF mutations to these inhibitors is not documented.
View Article and Find Full Text PDFSomatic mutations found within the tyrosine kinase domain (TKD) of the human epidermal growth factor (HER) family of receptors have been implicated in the development and progression of non-small cell lung cancer (NSCLC). However, no conclusive reports have described pathogenic mutations in kinase-impaired HER3. Here, we report a case of an advanced chemotherapy-resistant NSCLC, harboring a novel HER3(V855A) somatic mutation homologous to the EGFR(L858R)activating mutation.
View Article and Find Full Text PDF