In this study, we have characterized a panel of NSCLC cell lines with differential sensitivity to gefitinib for activating mutations in egfr, pik3ca, and k-ras, and basal protein expression levels of PTEN.
To determine whether SP-A aberrations are lung cancer-specific and indicate smoking-related damage, tricolor fluorescence in situ hybridization with SP-A and PTEN probes was done on touch imprints from the lung tumors obtained prospectively from 28 patients with primary NSCLC.
We have studied hypermethylation of the PTEN promoter, loss of heterozygosity (LOH) at microsatellites in chromosome 10q23 (surrounding and intragenic to the PTEN locus), and hypermethylation of PTEN's highly homologous pseudogene, PTENP1, and their association with PTEN protein loss in a surgical case series study of primary NSCLC.
The effects of PI3K/Akt inhibitors {LY294002, adenoviruses expressing dominant-negative mutant of the p85alpha adaptor subunit of PI3K (Ad-dnp85alpha), dominant-negative Akt [Ad-HA-Akt(KM)], or PTEN (Ad-PTEN)}, MKK4/c-jun NH2-terminal kinase (JNK) inhibitor [SP600215, adenovirus expressing dominant-negative MKK4, Ad-MKK4(KR)], and their combinations on proliferation and apoptosis in NSCLC cells were tested in vitro and in vivo using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a flow cytometry-based terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, Western blot and immunohistochemical analyses, and an NSCLC xenograft tumor model.
Here, we report that rosiglitazone reduced the phosphorylation of Akt and increased phosphatase and tensin homologue (PTEN) protein expression in non-small cell lung carcinoma (NSCLC) cells (H1792 and H1838), and this was associated with inhibition of NSCLC cell proliferation.
In this study, we tested whether gene transfer of wild-type PTEN into an NSCLC cell line with a known methylated PTEN promoter, H1299, would increase its sensitivity to ionizing radiation.
We previously demonstrated that a selective agonist of peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta), GW501516, stimulated human non-small cell lung carcinoma (NSCLC) growth, partly through inhibition of phosphatase and tensin homolog deleted on chromosome 10 expression.
We therefore studied TF gene (F3) expression and the status of genes coding for tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN), and serine/threonine kinase 11 (STK11) in non-small cell lung cancer (NSCLC).
These results show that methylation of specific promoter CpG sites in PTEN, RASSF1 and DAPK is associated with outcome in early stage surgically treated NSCLC.
Somatic mutations of phosphatase and tensin homolog deleted on chromosome ten (PTEN) in non-small cell lung cancers (NSCLCs) have been investigated in but a small number of cases.
Herein, we have examined the methylation status of the human PTEN gene in 137 primary non-small-cell lung cancers (NSCLCs) by using a methylation-specific PCR and correlated the results with clinicopathological features.
Tumor tissues showed an inverse correlation between miR-21 and PTEN protein. miR-21 inhibitor transfection increased a luciferase-reporter activity containing the PTEN-3'-UTR construct and increased PTEN protein but not PTEN-mRNA levels in NSCLC cell lines.
The current study provides evidence that genetic variations within the PI3K/PTEN/AKT/mTOR signaling pathway are associated with variation in clinical outcomes of NSCLC patients.
Our findings indicate that NEDD4-1 plays a critical role in the development of NSCLC and provides novel insight on the mechanisms that contribute to inactivate PTEN in lung cancer.
Our findings established the relevance of the combinatorial inactivation of p53 and PTEN in NSCLC progression and identified a subgroup of patients with a particularly aggressive disease.