Using Fisher's exact test and logistic regression, we compared the frequency of the known disease-causing MYH mutations Y165C, G382D and 466delE in 137 probands (117 cases with CRC and 20 cases diagnosed on the basis of adenomatous polyps only) from families with three or more CRCs but negative for mutations in the MMR genes and in 967 healthy controls with comparable ethnic backgrounds.
The primary objective of the current investigation was to determine whether folic acid would prevent LOH of the three tumor suppressor genes, deleted in colorectal cancer (DCC), adenomatous polyposis coli (APC) and p53 in macroscopically normal appearing rectal mucosa of patients with adenomatous polyps.
In the 4 adenomatous polyps with carcinomatous foci, BAT-26 positivity was detected in 2 cases (50%) in both (adenomatous and carcinomatous) components of the lesions. p53 immunoreactivity was observed in 6 adenomatous polyps, 2 of them with malignant transformation.
Serum levels of the mutant p53 protein in patients with colorectal cancer (mean=0.97+/-0.14 ng/ml, ranged from 0.7 ng/ml to 1.37 ng/ml, n=50) were significantly greater than those in patients with adenomatous polyp (mean=0.73+/-0.06 ng/ml, ranged from 0.69 ng/ml to 0.83 ng/ml) (p<0.001).
Adenomatous polyps of the appendix frequently had APC, KRAS and TP53 mutations and were morphologically and molecularly similar to adenomatous polyps of the colorectum.
Adenomatous polyps in the gastrointestinal system rarely occur in childhood and are accompanied by syndromes such as Familial adenomatous polyposis, attenuated familial adenomatous polyposis, and MUTYH-associated polyposis, Gardner and Turcot syndrome, and also mismatch repair (MMR) gene defects.
APC and KRAS mutations and microsatellite status were determined in colorectal lesions (colorectal carcinoma (CRC), hyperplastic (HP) and adenomatous polyps (AP)).
Using Fisher's exact test and logistic regression, we compared the frequency of the known disease-causing MYH mutations Y165C, G382D and 466delE in 137 probands (117 cases with CRC and 20 cases diagnosed on the basis of adenomatous polyps only) from families with three or more CRCs but negative for mutations in the MMR genes and in 967 healthy controls with comparable ethnic backgrounds.
Lynch syndrome displays many curious features that cannot be accounted for by the prevailing concepts of carcinogenesis and genetics: (1) CRCs occur preferentially in the right side of the colon, whereas the majority of sporadic cases develop in the left colon; (2) the increased risk of CRC is not associated with an increased incidence of adenomatous polyps, which are necessary precancerous lesions in the development of common CRCs; (3) the tumor spectrum in Lynch syndrome is restricted to the colon and some extracolonic sites, whereas the responsible MMR genes are ubiquitously expressed; (4) the tumor risk, which is negligible during childhood, becomes significant during adulthood at the age of 25 and thereafter remains essentially constant throughout the ages.
Somatic APC inactivation due to mutation or loss of heterozygosity (LOH) promotes the development of adenomatous polyps by stabilizing the transcriptional coactivator β-catenin.
The purpose of this study was to further evaluate the role of low activity MTHFR variants as well as to explore interactive effects between alcoholic drink consumption and MTHFR variants and risk of distal colorectal adenomatous polyps.
In this study, we have confirmed and refined the LOH-associated region in colorectal FAP: allelic loss in adenomatous polyps tended to occur when the germline mutation lay in the region of the APC gene between the first and second beta-catenin degradation repeats (codons 1285-1378).
Comparative immunohistologic analysis revealed strong membranous staining for beta-catenin in all adenomatous polyps, but only 1 adenoma showed nuclear accumulation.
Studies of the interaction between polymorphisms in the gene for methylenetetrahydrofolate reductase (MTHFR) and dietary components for risk of both colorectal cancer and adenomatous polyps provide a glimpse into the future of diet and cancer research.
The expression of CD44-mRNA was examined in 90 specimens from 44 patients with colorectal cancer or colorectal adenomatous polyps and in the peripheral blood leukocytes from 7 healthy volunteers by reverse transcription-polymerase chain reaction and Southern blot hybridization.
In the present study, expression of alternatively spliced variants of CD44 and their cellular distribution have been investigated in human colonic tumours and in the corresponding normal mucosa, in addition to benign adenomatous polyps.
We have developed a cancer vaccine, TetMYB, that targets MYB and aim to evaluate its efficacy in the prophylactic and therapeutic management of adenomatous polyps.
In addition, the plasma circ-ABCC1 level was related to tumor growth and progression, and the plasma circ-CCDC66 and circ-ABCC1 levels were decreased in precursor lesions of CRC, including colon adenomas and adenomatous polyps.