Normal or increased levels of MET mRNA and Met protein were consistently found in fresh samples of carcinomas as well as in epithelial tumor cell lines.
The antibodies revealed expression of c-MET protein in hepatomas (11/14), carcinomas of colon and rectum (19/21), stomach (11/22), kidney (16/19), ovary (9/17) and skin (7/17).
Now we report that the expression of the Met/HGF receptor is increased a hundred fold in 22 out of 41 human carcinomas derived from the thyroid follicular epithelium.
These results, overall, suggest that the 6.0-kb transcript of the c-met gene might participate in the development and progression of gastric carcinomas.
Recently, overexpression of the Met/HGF receptor gene has been detected in fresh samples of carcinomas and in epithelial tumor cell lines but not in cell lines derived from human leukemia and lymphoma.
Overexpression of the hepatocyte growth factor receptor (Met/HGF receptor), a transmembrane tyrosine kinase encoded by the met proto-oncogene, has been associated with tumor progression in different human carcinomas.
The results suggest that missense mutations located in the MET proto-oncogene lead to constitutive activation of the MET protein and papillary renal carcinomas.
Summarizing these and previous results, mutations of the MET proto-oncogene were detected in 17/129 sporadic papillary renal carcinomas but not in other solid tumors.
Overexpression of the hepatocyte growth factor receptor (Met/HGF receptor), a transmembrane tyrosine kinase encoded by the MET proto-oncogene, is involved in transformation and invasive behavior of human carcinomas and sarcomas.
These results suggest that the amplification and overexpression of c-met gene do not play a different role in the progression and metastasis of EBV-positive and EBV-negative gastric carcinomas.
The receptor tyrosine kinase MET is overexpressed in human colorectal adenomas and carcinomas, suggesting an instrumental role for MET signaling in the onset and progression of colorectal cancer.
Expression of Met, the Hepatocyte Growth Factor receptor, has been shown to have prognostic value in numerous types of cancer including breast, gastric, cervical and head and neck carcinomas.
c-MET/phospho-MET expression and MET BISH positivity were observed in 22.2%, 5.6%, and 10.9% of NSCLCs, respectively; they were more prevalent in ADCs (27.3%, 6.9%, and 11.5%, respectively) and sarcomatoid carcinomas (20.9%, 9.3%, and 36.6%, respectively) than in SCCs and large cell carcinomas.
In conclusion, our data suggest that mutation alone plays a minor role in causing aberrancies of the HGF/MET pathway in medulloblastoma in comparison with other malignancies such as breast, hepatocellular, renal, and lung carcinomas.