Because genetic and epigenetic alterations of the adenomatous polyposis coli (APC) gene are common events in gastrointestinal tumor development, we sought to investigate the frequency and level of aberrant APC promoter methylation in primary tumors and paired preoperative serum or plasma samples of lung cancer patients by semiquantitative methylation-specific fluorogenic real-time PCR.
The mutated genes with positive or negative roles in cell growth or survival in aneuploid gastrointestinal cancer (e.g., APC, K-ras, and p53) are less frequently mutated in near-diploid MMP gastrointestinal tumors.
Established MSH6-null mice present a frequent occurrence of gastrointestinal tumors without microsatellite instability (MI), suggesting the possibility of the APC gene being a mutational target.
Examples of these molecularly targeted biomarker therapies are: tyrosine kinase inhibitors in chronic myeloid leukemia and gastrointestinal tumors; anaplastic lymphoma kinase (ALK) inhibitors in lung cancer with EML4-ALk fusion; HER2/neu blockage in HER2/neu-positive breast cancer; and epidermal growth factor receptors (EGFR) inhibition in EGFR-mutated lung cancer.
Flow cytometric and immunoblotting analyses demonstrated that GLA treatment substantially reduced Her-2/neu protein levels in the Her-2/neu-overexpressing cell lines BT-474, SK-Br3, and MDA-MB-453 (breast cancer), SK-OV3 (ovarian cancer), and NCI-N87 (gastrointestinal tumor derived).
Mutational studies of 57 sporadic gastrointestinal tumor DNAs revealed the presence of length variations in three of them: (a) BLM; (b) CBL; and (c) HOXA1.
Acquired resistance to epidermal growth factor receptor (EGFR) targeted antibodies represents a clinical challenge in the treatment of gastrointestinal tumors such as metastatic colorectal cancer, but its molecular mechanisms are incompletely understood.
The presence of activating mutations within EGFR in both esophageal and pancreatic adenocarcinomas defines a previously unrecognized subset of gastrointestinal tumors in which EGFR signaling may play an important biological role.
Our results demonstrate a novel mechanism for activation of beta-catenin in gastrointestinal tumors and support the concept that overexpression of p73 isoforms can play an important role in tumorigenesis.
Mutation in K-RAS (K-RAS-MT) plays important roles in both cancer progression and resistance to anti-epidermal growth factor receptor (EGFR) therapy in gastrointestinal tumors.
Examples of these molecularly targeted biomarker therapies are: tyrosine kinase inhibitors in chronic myeloid leukemia and gastrointestinal tumors; anaplastic lymphoma kinase (ALK) inhibitors in lung cancer with EML4-ALk fusion; HER2/neu blockage in HER2/neu-positive breast cancer; and epidermal growth factor receptors (EGFR) inhibition in EGFR-mutated lung cancer.