The affected P53 activity caused by STK11 mutations in PJS patients is significantly associated with protein truncation, while cancer risk in PJS can be elevated through pathways rather than P53 pathway.
Expression of cyclo-oxygenase 2 was found in 11 of 12 PJS-related nasal polyps and 19 of 28 sporadic nasal polyps (p>0.05).Overexpression of p53 was not found.
In this study, we used sequencing analysis to investigate the STK11, CDH1, and TP53 loci for a germline mutation in two siblings with PJS with primary GC.
These findings suggest that STK11 is a tumor suppressor gene regulating the development of hamartomas, and that somatic mutation of p53 subsequently promotes gastrointestinal cancer at a later stage in PJS.
Thirty nine polyps and five carcinomas from 17 patients (from 13 families) with PJS were analysed for loss of heterozygosity (LOH) at 19p13.3 (STK11/LKB1 gene locus), 5q21 (APC gene locus), 18q21-22 (Smad4 and Smad2 gene locus), and 17p13 (p53 gene locus), and evaluated for immunohistochemical staining of p53.
We examined mutations of the LKB1, beta-catenin, APC, K-ras, and p53 genes in 27 gastrointestinal hamartomatous polyps from 10 patients in nine PJS families.