The present results demonstrated a higher participation of Ki-ras gene mutations in EHC than found in previous studies, and provided a confirmation and extension of the results earlier reported by Tada et al. and Tsuda et al. for IHC.
Here we report the development of a genetically engineered mouse model of IHCC that incorporates two of the most common mutations in human IHCC, activating mutations of Kras (Kras(G12D)) and deletion of p53.
The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (21%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA.
KRAS is mutated in 23 of 98 (23%) bile duct-type intrahepatic cholangiocarcinomas and in only 1 of 76 (1%) cholangiolar-type intrahepatic cholangiocarcinomas.
In this study, we analyze a large set of intrahepatic cholangiocarcinoma tumors (n = 54) for mutations in these genes and compare the clinical outcomes of wild type versus KRAS and BRAF mutant cases.
These latest advancements along with known mutations in KRAS/BRAF/EGFR and 11q13 high-level amplification have contributed to a better understanding of the landscape of molecular alterations in iCCA.
These data suggest that each of the examined genes is involved in the development of ICC and that the p53 and K-ras mutation may play a role in the tumor growth pattern.
We find that TP53-defective ICC patients are more likely to be HBsAg-seropositive, whereas mutations in the oncogene KRAS are nearly exclusively found in HBsAg-seronegative ICC patients.
In addition, point mutations of ras and p53 were examined genetically in selected ICC cases by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequence analysis.
The systematic screening for p53 mutations in European patients with hilar cholangiocarcinoma has shown that the type of mutation (except 175) is different and its incidence is much lower when compared to the pattern previously reported for intrahepatic cholangiocarcinoma in East Asian patients.
Genetic analyses revealed that KRAS mutation was significantly more frequent in type 1 ICC, whereas IDH mutation and FGFR2 translocation were restricted to type 2 ICC.
Isocitrate dehydrogenases 1 and 2 (IDH1/2), KRAS protooncogene GTPase (KRAS), a RAS Viral Oncogene Homolog in neoroblastoma (NRAS) and P53 are primary genetic alterations in ICC.
The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (21%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA.
We performed a case-control association study to evaluate the association between common polymorphisms in MTHFR (C677T and A1298C) and the Arg72Pro polymorphism in the p53 gene and the risk for cervical intraepithelial neoplasia (CIN) or invasive cervical cancer (ICC) in Mexican HPV-infected women.
KRAS and p53 mutations are associated with an aggressive disease prognosis while FGFR mutations may signify a relatively indolent disease course of intrahepatic cholangiocarcinoma.
Intrahepatic cholangiocarcinomas with chronic advanced liver disease showed higher EGFR mutation rate (5/38, 13.2% vs 1/43, 2.3%) and lower mutation rates of KRAS (3/38, 7.9% vs 8/43, 18.6%), MLH1 (2/38, 5.3% vs 5/43, 11.6%), and GNAS (1/38, 2.6% vs 5/43, 11.6%), compared with those in intrahepatic cholangiocarcinomas with normal liver.
KRAS and p53 mutations are associated with an aggressive disease prognosis while FGFR mutations may signify a relatively indolent disease course of intrahepatic cholangiocarcinoma.
Compared to ICC that was not associated with Thorotrast, the frequency of mutation of the KRAS gene was lower, while that of the TP53 gene was more than two times higher.
In conclusion, MDM2 amplification in large-duct iCCAs is more common than presently considered, and it may represent a unique biliary carcinogenetic process in which KRAS and TP53 mutations are less frequent.