To determine the role of the PTEN/MMAC1 gene in lung cancer, we screened 34 small cell lung cancer (SCLC) cell lines, 10 SCLC tumors, 13 non-small cell lung cancer (NSCLC) cell lines and 10 NSCLC tumors using Denaturing HPLC (DHPLC) and direct sequencing methods.
These data indicate that point mutations in the PTEN/MMAC1 gene are probably not an important factor in tumorigenesis and the progression of a major subset of lung cancers.
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.
Therefore, it was strongly indicated that activation of the PI3K/AKT/NFkB pathway by PTEN inactivation results in augmented invasiveness in lung cancer cells and lipid phosphatase activity of PTEN plays a key role in this process.
Our results suggest that TOPK is a potential therapeutic target in lung cancer that promotes cell migration by modulating a PI3K/PTEN/AKT-dependent signaling pathway; they also suggest that high TOPK expression, either alone or in combination with a low level of PTEN, may serve as a prognostic marker for lung cancer.
Other driver biomarkers in lung cancer (point mutations and rearrangements in specific genes including Her2, BRAF, NUT, MET, ROS1, DDR2, FGFR1, KRAS, and PTEN) might potentially provide additional information for clinical decision making.
The H358 erlotinib-resistant (ER) cells do not have a secondary EGFR mutation, neither MET gene amplification nor PTEN downregulation; these have been identified in lung cancers with the EGFR mutations.
Loss of PTEN function has been detected frequently in different forms of cancers, such as breast, prostate and lung cancer, gastric and colon cancer, skin cancer, as well as endometrial carcinoma.
Our previous study observed that the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was downregulated in thrombin-stimulated lung cancer.