Bisulfite-treated DNA samples from 73 eligible patients were amplified by quantitative methylation-specific polymerase chain reaction (QMSP) targeting 6 genes (deleted in colorectal cancer [DCC], endothelin receptor type B [EDNRB], homeobox protein A9 [HOXA9], kinesin family member 1A [KIF1A], nidogen-2 [NID2], and N-methyl D-aspartate receptor subtype 2B [NR2B]).
The methylation status of the UNC5C and DCC genes were examined in primary carcinomas and the corresponding normal tissues derived from 50 patients with colorectal cancer using quantitative methylation-specific polymerase chain reaction (qMSP).
Phenotypic analogy to mice with homozygous inactivation of Ntn1 encoding the secreted axonal guidance protein netrin1, or Dcc encoding its receptor Deleted in Colorectal Cancer led us to perform sequence analysis of NTN1 and DCC in all the patients.No pathogenic mutations were found.
Although none of these genetic alterations showed a significant prognostic value, specific mutation of K-ras gene and DCC LOH phenotype might have a predictive prognostic implication in colorectal cancer.
Data are insufficient to recommend the routine use of p53, ras, thymidine synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, microsatellite instability, 18q loss of heterozygosity, or deleted in colon cancer (DCC) protein in the management of patients with colorectal cancer.
However, thus far few studies have analyzed the impact of numerical abnormalities of chromosomes 17 and 18, which carry the p53 and DCC plus SHAD4/DPC4 genes involved in colorectal cancer, on the clinical and biological behaviors of the disease.
Whether or not the deleted in colorectal cancer (DCC) gene is implicated in metastases or in predicting prognosis in patients with colorectal cancer has not previously been substantiated.
It was subsequently shown that somatic mutations of these genes (APC, mismatch repair genes, TP53, KRAS, and DCC) also occur in sporadic colorectal cancer.
Protein expression of the putative tumour-suppressor gene DCC on chromosome 18q was evaluated in a panel of 16 matched colorectal cancer and normal colonic tissue samples together with DCC mRNA expression and allelic deletions (loss of heterozygosity, LOH).
Allelic imbalance and microsatellite instability of the DCC gene in colorectal cancer in patients under the age of 35 using fluorescent DNA technology.
Allelic loss of a portion of chromosome 18q and lack of expression of deleted in colorectal cancer (DCC) protein has been reported as an adverse prognostic indicator for stage II (i.e., Dukes' B2) colorectal cancer.
These results suggest that codon 201Gly of the DCC gene is not only associated with flat-type colorectal tumors, but that it may serve as a useful genetic marker for identifying groups at higher risk for colorectal cancer.
Twenty-five of 84 tumors had homozygous deletions at 18q21.1, a site that excludes DCC (a candidate suppressor gene for colorectal cancer) and includes DPC4, a gene similar in sequence to a Drosophila melanogaster gene (Mad) implicated in a transforming growth factor-beta (TGF-beta)-like signaling pathway.
Inactivation of the "deleted in colon cancer" (DCC) gene on chromosome 18 is known to be associated with the tumorigenesis and metastasis of colorectal cancer.
The data recorded in our series differ from other authors' data in three respects: a high incidence of pseudodiploid chromosome number, rearrangements of chromosome 19 and 15, and involvement of DCC gene in the development of gastric cancer, as well as in colorectal cancer as previously reported.
In addition, all 4 specimens of colorectal cancer with liver metastasis showed the decreased expression level of DCC mRNA, suggesting that functional loss of DCC in cancerous tissues may play an important role in metastatic events.