Molecular mechanisms altered in lung cancer include induced expression of oncogenes, such as RAS, MYC, c-erbB-2, and BCL-2, and loss of tumor-suppressor genes, such as RB, p53, and p16INK4A.
Our major conclusions are: (a) The death receptor pathway is differently inactivated at multiple levels in lung cancer cell lines; and (b) MYC amplification in SCLC is associated with inactivation of most components of the DISC complex, with resistance to TRAIL and with expression of c-FLIP.
The cooperation between p53 alteration and myc gene overexpression may occur during progression of lung cancer, but prognostic determinant is myc gene overexpression.
These results indicate that the p53-positive immunophenotype uncovers the occurrence of p53 point mutations in lung cancer and that p53 and c-myc gene alterations are important but represent independent occurrences in the development of lung tumors.
Here, we tested whether genomic gains in six specific loci, TP63 on 3q28, EGFR on 7p12, MYC on 8q24, 5p15.2, and centromeric regions for chromosomes 3 (CEP3) and 6 (CEP6), may provide further value in the prediction of lung cancer.
As our data imply that MAPJD is a novel member of the MYC transcriptional complex and its activation is a common feature of lung cancer, selective suppression of this pathway could be a promising therapeutic target for treatment of lung cancers.
Finally, BRG1 restoration significantly dampened invasion and progression and decreased MYC in lung cancer cells orthotopically implanted in nude mice.
Bioinformatic analysis of tumor transcriptomic data revealed regulatory gene networks and highlighted mortalin and moesin as master regulators while gene reporter and ChIP assays in the H1299 lung cancer cell line as well as cross-examination of published ChIP-sequence data of 7 human and 2 mouse cell lines provided strong evidence for the identified genes to be c-Myc targets.
In conclusion, the functional variant rs7726159 confers lung cancer susceptibility might by affecting MYC binding and inducing telomere lengthening, which provides a new insight into the crucial role of telomere biology in tumorigenesis.
Interestingly, in an EGFR mutated lung cancer cell line, treatment with an EGFR inhibitor (Gefitinib) resulted in a concentration specific reduction in c-MYC and miR-9 expression while not changing let-7a expression.
Here we used multiple mouse models of lung adenocarcinoma to identify genetic events that can cooperate with MYC activation to promote the genesis of non-small-cell lung cancer (NSCLC), the most common form of lung cancer in humans.
Finally, RNA profiling of lung epithelial cells (BEAS-2B) expressing a mutant allele of PIK3 (E545K) identified a network of transcription factors such as MYC, FOS and HMGA1, not previously recognised to be associated with aberrant PI3K signalling in lung cancer.
We also examined the expression of CIP2A protein by immunohistochemistry in 90 lung cancer specimens and correlated its expression with c-MYC expression and clinicopathological parameters.