Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Loss of heterozygosity (LOH) at the mannose 6-phosphate/insulin-like growth factor 2 receptor gene locus (M6P/IGF2R) on 6q26-27 has recently been demonstrated in approximately 30% of both invasive and in situ breast cancers. LOH was coupled with somatic point mutations in the remaining allele in several instances, leading to the proposition that M6P/IGF2R is a tumor suppressor gene. Somatic mutations in M6P/IGF2R have also been described in hepatoma and gastrointestinal cancers with the replication error positive (RER+) phenotype. These data indicate that M6P/IGF2R loss of function mutations may be involved in the pathogenesis of a wide spectrum of malignancies. Extensive data on the normal function of the M6P/IGF2R suggest that loss of M6P/IGF2R activity may contribute to multiple aspects of tumor pathophysiology, including deregulated growth, apoptosis, angiogenesis and invasion.
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PMID:The mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R), a putative breast tumor suppressor gene. 951 81

Hepatocellular carcinoma (HCC) is linked etiologically to viruses (hepatitis B virus [HBV] and hepatitis C virus [HCV]), chemical carcinogens (i.e., aflatoxins), and other environmental and host factors causing chronic liver injury. Some hepatoblastomas may be linked to inherited gene mutations, but adult hereditary HCC appears to be rare. HCCs display gross genomic alterations, including DNA rearrangements associated with HBV DNA integration, loss of heterozygosity, and, less importantly, chromosomal amplifications and loss of imprinting. Many genes with somatic mutations have now been identified in these tumors. Most frequently involved genes are tumor suppressor genes such as p53, M6P/IGF2R, beta-catenin, p16INK4A, and retinoblastoma genes. Most identified mutations are somatic, but germline mutations of p16INK4A, APC, and BRCA2 have also been reported. Oncogenic activation of several cellular genes such as cyclin D and cyclin A have been described in HCC, but the possible implication of candidate viral oncogenes (i.e., X protein of HBV) is still debated. A comprehensive analysis of all the genetic changes described for HCC demonstrates that at least four different growth regulatory pathways are altered in these tumors. However, each pathway appears to be implicated in a limited fraction of these tumors, suggesting that HCCs are genetically heterogenous neoplasms. This genetic heterogeneity correlates with the heterogeneity of etiologic factors implicated in HCC.
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PMID:Genetic aspects of hepatocellular carcinogenesis. 1051 3

Information about M6P/IGF2R and p53 genes in hepatocarcinogenesis is limited and controversial. We tested the loss of heterozygosity (LOH) of M6P/IGF2R and p53 genes in cirrhotic and neoplastic foci in surgically resected livers of 30 patients with hepatocellular carcinoma (HCC). The DNAs extracted from microdissected specimens were used for polymerase-chain-reaction (PCR)-based assay. LOH of the M6P/IGF2R gene in the primary HCCs was detected in 10 of 22 informative cases (45%). In five of these 10 cases (50%), LOH was detected in cirrhotic lesions adjacent to the HCCs. The allelic loss patterns of M6P/IGF2R in liver cirrhosis (LC) were identical to those in the corresponding HCC, suggesting that HCC could develop from one of the cells in which M6P/IGF2R had been lost. Furthermore, LOH of the p53 gene in HCC was detected in 10 (43%) of 23 informative cases, and p53 loss in cirrhotic foci adjacent to HCC was shown in one of the 10 cases (10%). The pattern of allelic loss of the p53 gene in the cirrhotic foci was identical with that in the corresponding tumor. The LOH of the M6P/IGF2R and p53 genes occurred independently in HCCs. LOH of the M6P/IGF2R locus was a relatively frequent and possibly early event in hepatocarcinogenesis, and LOH of the M6P/IGF2R gene and LOH of the p53 gene occurred independently.
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PMID:Loss of heterozygosity of the mannose 6-phosphate/insulin-like growth factor II receptor and p53 genes in human hepatocellular carcinoma. 1128 87

Mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF2R) tumor suppressor- gene mutation is an early event in human hepatocellular carcinoma (HCC) formation in the United States, but its role in hepatocarcinogenesis in Japan is unclear. We therefore determined M6P/IGF2R mutation frequency in HCCs from patients who resided in the southern, central, and northern regions of Japan. Ten single nucleotide polymorphisms were used to identify HCCs and dysplastic liver nodules with M6P/IGF2R loss of heterozygosity. The retained allele in these tumors was also assessed for point mutations and deletions in the M6P/IGF2R ligand binding domains by direct sequencing of polymerase chain reaction (PCR) amplified DNA products. Fifty-eight percent (54 of 93) of the patients were heterozygous at the M6P/IGF2R locus, and 67% (43 of 64) of the HCCs and 75% (3 of 4) of the dysplastic nodules had loss of heterozygosity. The remaining allele in 21% of the HCCs contained either M6P/IGF2R missense mutations or deletions, whereas such mutations were not found in the dysplastic lesions. In conclusion, M6P/IGF2R is mutated in HCCs from throughout Japan with a frequency similar to that in the United States. Loss of heterozygosity in dysplastic liver nodules provides additional evidence that M6P/IGF2R haploid insufficiency is an early event in human hepatocarcinogenesis.
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PMID:M6P/IGF2R tumor suppressor gene mutated in hepatocellular carcinomas in Japan. 1198 65

It was reported that 60-70% of hepatitis B virus (HBV)-negative hepatocellular carcinoma (HCC) had loss of heterozygosity (LOH) at the mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF2R) locus and this gene was mutated in 55% of these patients with LOH. In this study, genomic DNA from 29 pairs of HBV-positive HCC and corresponding non-tumor tissues was used to analyze LOH at the M6P/IGF2R locus and single deoxyguanosine deletion in this gene by PCR. Total RNA from 19 of the 29 patients was utilized to determine a 192 bp insert in the M6P/IGF2R mRNA and expression of this gene by RT-PCR. Twenty-eight of 29 (97%) HBV-positive HCC were found to be informative at the M6P/IGF2R locus but LOH at this region was only detected in 4/28 (14%) informative patients. Neither single deoxyguanosine deletion in this gene nor 192 bp insert in its mRNA occurred in these patients. Compared with corresponding non-tumor tissues, expression of the M6P/IGF2R mRNA was decreased in 13/19 (68%) HBV-positive HCC tissues, suggesting that M6P/IGF2R may be involved in HBV-associated hepatocarcinogenesis by the regulation of its expression level. In the development of HBV-associated HCC, M6P/IGF2R mutation may not be a major agent.
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PMID:Genetic changes and expression of the mannose 6-phosphate/insulin-like growth factor II receptor gene in human hepatitis B virus-associated hepatocellular carcinoma. 1273 21

The risk for hepatocellular carcinoma (HCC) development is significantly heightened in the atomic bomb survivors, but the mechanism is unclear. We have previously reported finding a radiation dose-dependent increase in HCCs with TP53 mutations from the survivors. We now show that, in the same HCC samples, the frequency of 3'-untranslated region (3'UTR) mutations in M6P/IGF2R, a candidate HCC tumor suppressor gene, decreases with dose (P = 0.0091), implying a radiation dose-dependent negative selection of cells harboring such mutations. The fact that they were in the 3'UTR implicates changes in transcript stability rather than in protein function as the mechanism. Moreover, these M6P/IGF2R 3'UTR mutations and the TP53 mutations detected previously were mutually exclusive in most of the tumors, suggesting two independent pathways to HCC development, with the TP53 pathway being more favored with increasing radiation dose than the M6P/IGF2R pathway. These results suggest that tumors attributable to radiation may be genotypically different from tumors of other etiologies and hence may provide a way of distinguishing radiation-induced cancers from "background" cancers--a shift from the current paradigm.
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PMID:A dose-dependent decrease in the fraction of cases harboring M6P/IGF2R mutations in hepatocellular carcinomas from the atomic bomb survivors. 1714 73