Related Experiment Videos
Ras mutations in human pituitary tumors.
H J Karga1, J M Alexander, E T Hedley-Whyte
1Department of Medicine, Massachusetts General General Hospital, Boston 02114.
The Journal of Clinical Endocrinology and Metabolism
|April 1, 1992
Summary
Ras mutations are rare in pituitary tumors, but a specific H-ras gene mutation was found in a fatal, invasive prolactinoma. This finding suggests ras mutations may indicate aggressive pituitary neoplasia.
Area of Science:
- Oncology
- Genetics
- Endocrinology
Background:
- The cellular origins of pituitary tumors (neoplasia) are not well understood.
- Activating mutations in ras proto-oncogenes are implicated in various human cancers.
- Ras gene alterations are potential genetic factors in pituitary tumor development.
Purpose of the Study:
- To investigate the presence and significance of ras mutations in pituitary tumors.
- To determine if ras mutations are associated with specific pituitary tumor subtypes or invasiveness.
Main Methods:
- Analyzed DNA from 19 pituitary tumors (11 nonfunctioning adenomas, 6 somatotroph adenomas, 2 prolactinomas).
- Amplified K-ras, N-ras, and H-ras genes using polymerase chain reaction.
- Screened for mutations affecting GTPase activity via oligonucleotide-specific hybridization.
Main Results:
- No ras mutations were detected in 18 out of 19 pituitary adenomas.
- A mutation in codon 12 of the H-ras gene (Glycine to Valine) was identified in one recurrent prolactinoma.
- This specific prolactinoma was highly invasive and associated with a fatal outcome.
Conclusions:
- Ras mutations are infrequent genetic alterations in pituitary adenomas.
- The identified H-ras mutation in an aggressive prolactinoma may serve as a potential biomarker for highly invasive pituitary tumors.