Mutations in codon I 2 of K-ras occur in a high proportion of pancreatic cancer cases. Although there is evidence that p53 mutations also occur in this tumor, few studies have been reported to date and no comparison has been made of K-ras and p53 mutations in the same tissues. Single-strand conforma
K-ras and p53 mutations in the pathogenesis of classical and goblet cell carcinoids of the appendix
β Scribed by Dharam M. Ramnani; Ignacio I. Wistuba; Carmen Behrens; Adi F. Gazdar; Leslie H. Sobin; Jorge Albores-Saavedra
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 603 KB
- Volume
- 86
- Category
- Article
- ISSN
- 0008-543X
No coin nor oath required. For personal study only.
β¦ Synopsis
BACKGROUND.
Mutations in the K-ras oncogene and the p53 tumor suppressor gene are present in approximately 50% of colonic adenocarcinomas. Goblet cell carcinoids (GCCs) are uncommon neoplasms of the appendix that appear to be intermediate between carcinoid tumors and adenocarcinomas, both histologically and biologically. The current study was undertaken to examine the role of p53 and K-ras mutations in the pathogenesis of GCCs and typical carcinoids (TCs) of the appendix.
METHODS.
Archival materials from 22 GCCs and 18 TCs were analyzed. K-ras mutations in codons 12, 13, and 61 were studied by a polymerase chain reaction (PCR) based designed restriction fragment length polymorphism method using mismatched nested primers. Mutations in exons 5-8 of the p53 tumor suppressor gene were analyzed in 16 GCCs and 18 TCs by PCR and single-strand conformational polymorphism followed by direct sequencing. Immunostains for p53 and chromogranin were performed in all cases.
RESULTS. K-ras mutations and nuclear accumulation of p53 by immunohistochemistry were not detected in any of the GCCs or TCs. p53 mutations were found in 4 of 16 GCCs (25%) and 8 of 18 TCs (44%). Immunoreactivity for chromogranin was seen in the vast majority of GCCs and TCs.
CONCLUSIONS. p53 mutations appear to play a role in the pathogenesis of some
GCCs and in approximately 50% of TCs of the appendix, whereas mutations in the K-ras oncogene do not appear to be important in the development of these tumors.
The minimal cytologic atypia, low incidence of metastases, and lack of K-ras mutations in goblet cell appendiceal neoplasms suggest that they are variants of carcinoid tumors. Our findings lend support to the recommendation that the therapeutic guidelines applied to TCs of the appendix should be the same for GCCs.
π SIMILAR VOLUMES
Between
BACKGROUND. Adenocarcinomas and carcinoid tumors are
## Abstract Gene mutations in __APC__, __Kβras__, and __p53__ are thought to be essential events for colorectal cancer development. Recent data seem to indicate that __Kβras__ and __p53__ mutations rarely coβexist in the same tumor, indicating that these alterations do not represent a synergistic e
An anomalous junction of the pancreaticobiliary duct (AJPBD) was thought to be an important risk factor for gallbladder carcinoma in Japan. In this report, we compared K-rus and p53 mutations in Stage I gallbladder carcinomas (GC) of patients with AJPBD with those in patients without AJPBD. METHODS.
In contrast to the origins of colorectal carcinomas, the mechanisms of carcinogenesis in the small intestine remain unclear. We therefore analyzed the mutational status of the Ki-ras, p53, and adenomatous polyposis coli (APC) genes in primary carcinomas of the small intestine and compared the mutati