On examination of DNA from dewaxed sections of the tumor, we found no p53 mutation in the tumor tissue, but found two K-ras mutations in codon 12; this pattern of mutation commonly occurs in pancreatic carcinoma, indicating a somewhat genetic relationship of OGTP to pancreatic carcinoma.
This study confirms that loss of chromosomes, particularly chromosomes 17 and 18, which carry the p53 and DCC genes, are common in pancreas cancer.Chromosome 20 is also frequently lost.
From these, K-ras mutations detected in blood, stool and bile juice of patients at risk for pancreatic cancer seem to be more promising than p53 alterations as a more later step in carcinogenesis, although they are neither yet well established nor standardised by reliable assays.
Therefore, it is concluded that simultaneously aberrant expression of Bcl-2 and p53 may confer PC with more malignant clinicopathological characteristics.
The p16(INK4a) (MTS-1, CDKN2) gene product acts in the same pathway as p53 to inhibit cell cycle progression at G1/S. p16(INK4a) is deleted and/or mutated in a significant fraction of human tumors, including pancreatic carcinoma.
A molecular examination of Ki-ras codon 12 and p53 mutations therefore enables us to predict, to some degree, the occurrence of liver and lymph node metastasis in pancreatic carcinoma.
Using a novel improved primer extension and preamplification polymerase chain reaction, we analyzed microdissected paraffin-embedded specimens of pancreatic carcinoma (n = 29) and their corresponding pancreatic intraductal lesions (PIL, n = 331) for loss of heterozygosity (LOH) of p16(INK4), DPC4, and p53 by microsatellite analysis and for p53 protein by immunohistochemistry.
Studies have demonstrated that pancreatic cancer is associated with various genetic abnormalities in oncogenes and tumor suppressor genes including p53.
These data demonstrate that overexpression of p21(WAF1/CIP1) occurs early in the development of PanIN, before aberrations in p53, cyclin D1, and DPC4/Smad4 expression. p21(WAF1/CIP1) overexpression, independent of p53 and/or DPC4/Smad4 expression, may reflect increased Ras activity, either directly through activating K-ras mutations or as a consequence of HER-2/neu (ERBB2) overexpression, both of which are common in PC and in early events in the development of PanIN.
Restoration of transforming growth factor-beta signaling enhances radiosensitivity by altering the Bcl-2/Bax ratio in the p53 mutant pancreatic cancer cell line MIA PaCa-2.
Activation of the proto-oncogene K-Ras and inactivation of the tumour suppressor gene loci INK4a, p53 and SMAD4 are characteristic for pancreatic cancer.
The aim of the current study was conducted to investigate the association between p53 mutation and VEGF expression and the prognostic value of these factors in pancreatic carcinoma.