Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To evaluate the role of p16 multiple tumor suppressor (MTS1) and p53 protein in human radiation-induced skin cancer, we examined the expression of p16 and p53 in eight cases using immunohistochemistry. An abnormal location of p16 expression in the cytoplasm was found in seven of eight cases, but the expression of p53 in nuclei was noted in only three of eight cases. These findings suggest that the inactivation of p16 might be related to its binding with another unknown oncoprotein in the cytoplasm and thus lead to carcinogenesis.
 ...
PMID:Abnormal location of p16 protein and overexpression of p53 protein in human radiation-induced skin cancer. 747 71

Changes which lead to excessive cyclin production or to loss of cell cycle inhibition by proteins such as p16/MTS1 may release breast tumour cells from the constraints of cell division. In order to establish the frequency of MTS1/p16 gene alteration and its relation with genetic damage to the p53 and cyclin D1 genes, we have studied these gene abnormalities in 164 human primary breast cancers and in six breast cancer cell lines. Two breast cancer cell lines and one primary tumour showed a homozygous deletion of exon 2 of the MTS1 gene. Using single-strand conformation polymorphism and subsequent sequencing analysis, one tumour showed an alteration at codon 67 (CCC-->CTC; Pro to Leu). Another tumour showed a mutation at codon 98 (without amino acid change) with an additional polymorphism at codon 140. This polymorphism was also found in 13 other tumour samples, but has no effect on (disease-free) survival. From these data we conclude that the occurrence of CDKN2 (p16/MTS1) mutation in primary breast cancer is a rare event and is not likely to be involved in human breast tumour carcinogenesis and progression.
 ...
PMID:Infrequent CDKN2 (MTS1/p16) gene alterations in human primary breast cancer. 754 49

Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour suppressor genes (TSGs) with an important role in multistage carcinogenesis. At the 9p arm is located the p16 (MTS1) TSG and probably others with an effect on various human tumours such as acute lymphoblastic leukaemia, bladder cancer, gliomas, malignant mesotheliomas, melanomas and non-small cell lung carcinomas. In addition, the 17q arm harbours BRCA1 TSG which is responsible for approximately 80% of the familial breast/ovarian cancer cases. In order to investigate the implication of these performed a loss of heterozygosity (LOH) analysis with 10 polymorphic microsatellite markers (three at the 17q arm surrounding the BRCA1 region and seven at the 9p arm). Fourteen of the 17 (82%) tumours exhibited deletions at 9p. The highest incidence of LOH (6/13, 46%) was found for the marker D9S157 at 9p22. One sample exhibited deletion of all the informative markers tested indicating deletion of the complete 9p arm. No homozygous deletions were found. LOH at the 17q arm near the BRCA1 locus was found in 6 (35%) among 17 specimens. The results of this study indicate that allelic deletions at 9p are frequent in the development of laryngeal tumours. The highest incidence of LOH was found for the marker D9S157 which is near, but distinct from the location of p16 (MTS1) tumour suppressor gene, indicating the presence of multiple tumour suppressor genes within this chromosomal region. In addition, BRCA1 TSG is implicated in the development of laryngeal tumours.
 ...
PMID:Loss of heterozygosity at 9p and 17q in human laryngeal tumors. 758 72

Nasopharyngeal carcinoma (NPC) is a malignancy which occurs at high incidence in southern China and southeast Asia. The molecular mechanism of this disease, however, is not well understood. Recently, a homozygous deletion and/or loss of heterozygosity on chromosome 9p21-22 was found in several primary NPCs (Huang et al., Cancer Res. 54: 4003-4006, 1994), suggesting that a potential tumor suppressor gene(s) residing in this region may play a role in nasopharyngeal carcinogenesis. Since p16/MTS1, a potential tumor suppressor gene, whose mutations/deletions are frequently found in variety of tumor cells, was mapped to chromosome 9p21, we investigated the possible involvement of this gene in the development of NPC by mutational and Northern blot analysis. SSCP-direct sequencing revealed no point mutations of the p16/MTS-1 gene in any of 42 primary NPC biopsies from three geographical regions nor in two NPC cell lines. We did, however, observe a codon 140ala-->thr polymorphism in the gene, which has been previously reported as a point mutation. Furthermore, Northern analysis revealed a decreased expression of the p16/MTS1 gene in two out of two NPC cell lines as compared with immortalized/nontransformed cell lines. These results suggest that down regulation rather than a point mutation of the p16/MTS1 gene may play a role in the genesis of NPC.
 ...
PMID:No point mutation but decreased expression of the p16/MTS1 tumor suppressor gene in nasopharyngeal carcinomas. 786 58

Multiple factors, both environmental and genetic, are thought to play roles in breast carcinogenesis. The recently cloned multiple tumor suppressor gene (MTS1), the product of which interacts with CDK4 to regulate cell growth, has been found to be mutated with high frequency in a variety of cell lines as well as primary tumors of different histologic types. Using PCR-SSCP, we analyzed exons one (126 bp) and two (307 bp) of the MTS1 gene to determine the incidence of mutation in a population of 50 primary breast adenocarcinomas and corresponding normal tissue. Analysis of five breast tumor cell lines was also performed. We found no mutations in the MTS1 gene in the primary breast tumor samples. One cell line was found to have a homozygous deletion of the gene. Our results suggest that the MTS1 gene is not mutated with increased frequency in primary breast tumors, and thus may not play a major role in breast carcinogenesis.
 ...
PMID:Analysis of MTS1/CDK4 in female breast carcinomas. 788 33

The MTS1/CDK4I gene encodes a 16 kDa cyclin kinase inhibitor and maps to chromosome 9p21. Previous studies have suggested the presence of a major tumour suppressor gene at this locus which may be inactivated in head and neck squamous cell carcinoma (HNSCC). To determine the status of this gene in human primary and metastatic HNSCC, we examined the locus and its transcript for abnormalities by polymerase chain reaction (PCR). Out of 14 cell lines studied, four had lost only exon 1, one had lost only exon 2, three had lost both exons 1 and 2, and none of the remaining six lines expressed a normal p16 mRNA. These latter six cell lines expressed p16 transcripts that had suffered deletions ranging in size from 2-16 base pairs. In each case, deletions led to a change of reading frame. Furthermore, in two cases abnormalities in the MTS1/CDK4I gene were identical in cells derived from metastatic tumours as compared to cells derived independently from the corresponding primary tumour. The identical nature of mutations observed in primary tumours and metastases derived from the same patient provides strong evidence that inactivation of p16 function was an in vivo event.
Carcinogenesis 1994 Dec
PMID:MTS1/CDK4I is altered in cell lines derived from primary and metastatic oral squamous cell carcinoma. 800 Dec 21

We previously reported frequent loss of heterozygosity on chromosome 9p in esophageal carcinomas and suggested that a tumor suppressor gene located on this chromosomal arm might be involved in development of these cancers. Since recently published studies have shown that a gene mapped on chromosome 9p21, MTS1/CDK4I (multiple tumor suppressor 1/cyclin-dependent kinase 4 inhibitor), is frequently mutated in various types of tumors, we chose to examine esophageal squamous cell carcinomas for mutations in this candidate gene. DNA sequence analyses revealed somatic mutations of MTS1/CDK4I in 14 of 27 tumors examined; 8 were frame-shift mutations and 6 were missense mutations. These results suggested that the MTS1/CDK4I gene is a tumor suppressor the inactivation of which plays an important role during carcinogenesis of the squamous cell type of esophageal carcinoma.
 ...
PMID:Frequent somatic mutation of the MTS1/CDK4I (multiple tumor suppressor/cyclin-dependent kinase 4 inhibitor) gene in esophageal squamous cell carcinoma. 801 57

Cytogenetic abnormalities of chromosome 9p21-22 have been documented in human non-small cell lung carcinomas (NSCLC). Recently, a candidate tumor suppressor gene, MTS1/CDK4l, was identified in this chromosomal region and frequent homozygous deletions of this gene were found in cancer cell lines derived from various types of tissues. We screened 64 primary NSCLCs, including 31 adenocarcinomas and 33 squamous cell carcinomas, for mutations in MTS1/CDK4l, and detected somatic mutations in 19 of the 64 tumors examined. Five were deletions and 14 were missense mutations. These results suggest that inactivation of MTS1/CDK4l plays an important role during carcinogenesis of NSCLC.
 ...
PMID:Somatic mutations of the MTS (multiple tumor suppressor) 1/CDK4l (cyclin-dependent kinase-4 inhibitor) gene in human primary non-small cell lung carcinomas. 806 Mar 23

p16 (CDKN2/MTS1/p16INK4a) is frequently deleted, methylated, or mutated in many malignancies including squamous cell carcinoma of the head and neck (HNSCC). p16 beta is an alternative transcript derived from a newly described exon (exon 1 beta) located more than 15 kb 5' to exon 1 of p16. Moreover, the p16 beta transcript theoretically encodes a protein distinct from p16 derived from a divergent reading frame putatively initiated in exon 1 beta. To test the contribution of both of these transcripts in carcinogenesis, full-length cDNA of p16 and p16 beta were cloned in separate vector constructs and then transfected into HNSCC cell lines characterized for p16 status (p16[+/+], p16[mut/-], and p16[methylated]). Transfection of either p16 or p16 beta resulted in marked growth inhibition in all three HNSCC lines tested, regardless of p16 status. However, p16 beta but not p16 inhibited the growth of HeLa cells, a cell line with inactive pRB due to expression of E7 papillomavirus protein. Moreover, transfection of all three HNSCC lines with either p16 or p16 beta resulted in a marked increase in cells in G0-G1 consistent with a cell cycle arrest in G1. These data are consistent with the hypothesis that p16 and p16 beta are growth-inhibitory genes active in HNSCC and that both act by blocking progression through the G1-S transition of the cell cycle. Furthermore, the suppressive effects of p16 beta on HeLa growth suggest that p16 beta mediates its effect independently from pRB.
 ...
PMID:p16 and p16 beta are potent growth suppressors of head and neck squamous carcinoma cells in vitro. 879 77

Cyclin-dependent kinase-4 inhibitor genes (INK4) regulate the cell cycle and are candidate tumor-suppressor genes. To determine if alterations in the coding regions of the p18 and p19 genes, which are novel members of the INK4 family and if they correlate with the development of human cancer, 100 human cancer cell lines were analyzed. Two other INK4 gene family members, p15INK4b/MTS2 and p16INK4/MTS1 genes were also analyzed. Homozygous deletions of the p15INK4b/MTS2 gene were detected in 29 cancer cell lines. Thirty-five homozygous deletions and 7 intragenic mutations of the pl6INK4/MTS1 gene were also detected in these cell lines. Neither homozygous deletions nor intragenic mutations of the p18 and p19 genes were found except in an ovarian cancer cell line, SKOV3, harboring a single base pair deletion in exon 1 of p19. In p16INK4/MTS1 expression analysis, 5 cell lines with both authentic and alternative spliced p16INK4/MTS1 mRNA had no detectable p16INK4/MTS1 protein. These results suggest the hypotheses that either post-translational modification or enhanced degradation may be responsible for the lack of detection of the p16INK4/MTS1 protein. Using Western blot analysis, subsets of 26 human cancer cell lines were examined for p18 expression and 39 cell lines for p19 expression. All of these cell lines expressed the p18 or p19 protein, with the exception of SKOV3, which did not express p19. Therefore, the INK4 gene family may be divided into 2 groups. One group includes p15INK4b/MTS2 and p16INK4/MTS1, in which genetic and epigenetic alterations might contribute to the development of human cancers. The other group includes p18 and p19, in which somatic mutations are uncommon in many types of human cancer, and their role in human carcinogenesis and cancer progression is uncertain.
 ...
PMID:Molecular analysis of the cyclin-dependent kinase inhibitor genes p15INK4b/MTS2, p16INK4/MTS1, p18 and p19 in human cancer cell lines. 893 42


1 2 3 Next >>