Tags

Type your tag names separated by a space and hit enter

Abrogation of the Rb/p16 tumor-suppressive pathway in virtually all pancreatic carcinomas.
Cancer Res 1997; 57(15):3126-30CR

Abstract

The Rb/p16 tumor-suppressive pathway is abrogated frequently in human tumors, either through inactivation of the Rb or p16INK4a/CDKN2/MTS1 tumor-suppressor proteins, or through alteration or overexpression of the cyclin D1 or cyclin-dependent kinase 4 oncoproteins. We reported previously that the p16 gene was genetically inactivated in 82% of pancreatic carcinomas. Nearly half of these inactivations were by intragenic mutation of p16, and the remainder were by homozygous deletion of the gene. Here, we analyzed pancreatic carcinomas for additional mechanisms by which the Rb/p16 pathway might be inactivated. Transcriptional silencing of the p16 gene in association with methylation of its 5'-CpG island was examined by methylation-specific PCR in 18 pancreatic carcinomas. Nine of these were known to harbor an intragenic mutation in p16, and nine had a wild-type p16 coding sequence. Seven of the 18 tumors were hypermethylated, and all 7 were p16 wild-type (P = 0.001). Complete silencing of transcription from methylated wild-type gene sequences was demonstrated. Immunohistochemical analysis revealed normal expression levels of the Rb protein in all carcinomas studied. None of the carcinomas had genomic amplification of the cyclin D1 or CDK4 genes, and none had mutation of the p16-binding domain of CDK4. An additional p16 mutation was identified. In total, the Rb/p16 pathway was abrogated in 49 of the 50 carcinomas (98%) studied, all through inactivation of the p16 gene. Similar results were obtained in an independently analyzed series of 19 pancreatic carcinomas. These data demonstrate the central role of the Rb/p16 pathway in the development of pancreatic carcinoma.

Authors+Show Affiliations

Department of Oncology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9242437

Citation

Schutte, M, et al. "Abrogation of the Rb/p16 Tumor-suppressive Pathway in Virtually All Pancreatic Carcinomas." Cancer Research, vol. 57, no. 15, 1997, pp. 3126-30.
Schutte M, Hruban RH, Geradts J, et al. Abrogation of the Rb/p16 tumor-suppressive pathway in virtually all pancreatic carcinomas. Cancer Res. 1997;57(15):3126-30.
Schutte, M., Hruban, R. H., Geradts, J., Maynard, R., Hilgers, W., Rabindran, S. K., ... Herman, J. G. (1997). Abrogation of the Rb/p16 tumor-suppressive pathway in virtually all pancreatic carcinomas. Cancer Research, 57(15), pp. 3126-30.
Schutte M, et al. Abrogation of the Rb/p16 Tumor-suppressive Pathway in Virtually All Pancreatic Carcinomas. Cancer Res. 1997 Aug 1;57(15):3126-30. PubMed PMID: 9242437.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Abrogation of the Rb/p16 tumor-suppressive pathway in virtually all pancreatic carcinomas. AU - Schutte,M, AU - Hruban,R H, AU - Geradts,J, AU - Maynard,R, AU - Hilgers,W, AU - Rabindran,S K, AU - Moskaluk,C A, AU - Hahn,S A, AU - Schwarte-Waldhoff,I, AU - Schmiegel,W, AU - Baylin,S B, AU - Kern,S E, AU - Herman,J G, PY - 1997/8/1/pubmed PY - 1997/8/1/medline PY - 1997/8/1/entrez SP - 3126 EP - 30 JF - Cancer research JO - Cancer Res. VL - 57 IS - 15 N2 - The Rb/p16 tumor-suppressive pathway is abrogated frequently in human tumors, either through inactivation of the Rb or p16INK4a/CDKN2/MTS1 tumor-suppressor proteins, or through alteration or overexpression of the cyclin D1 or cyclin-dependent kinase 4 oncoproteins. We reported previously that the p16 gene was genetically inactivated in 82% of pancreatic carcinomas. Nearly half of these inactivations were by intragenic mutation of p16, and the remainder were by homozygous deletion of the gene. Here, we analyzed pancreatic carcinomas for additional mechanisms by which the Rb/p16 pathway might be inactivated. Transcriptional silencing of the p16 gene in association with methylation of its 5'-CpG island was examined by methylation-specific PCR in 18 pancreatic carcinomas. Nine of these were known to harbor an intragenic mutation in p16, and nine had a wild-type p16 coding sequence. Seven of the 18 tumors were hypermethylated, and all 7 were p16 wild-type (P = 0.001). Complete silencing of transcription from methylated wild-type gene sequences was demonstrated. Immunohistochemical analysis revealed normal expression levels of the Rb protein in all carcinomas studied. None of the carcinomas had genomic amplification of the cyclin D1 or CDK4 genes, and none had mutation of the p16-binding domain of CDK4. An additional p16 mutation was identified. In total, the Rb/p16 pathway was abrogated in 49 of the 50 carcinomas (98%) studied, all through inactivation of the p16 gene. Similar results were obtained in an independently analyzed series of 19 pancreatic carcinomas. These data demonstrate the central role of the Rb/p16 pathway in the development of pancreatic carcinoma. SN - 0008-5472 UR - https://www.unboundmedicine.com/medline/citation/9242437/Abrogation_of_the_Rb/p16_tumor_suppressive_pathway_in_virtually_all_pancreatic_carcinomas_ L2 - http://cancerres.aacrjournals.org/cgi/pmidlookup?view=long&pmid=9242437 DB - PRIME DP - Unbound Medicine ER -