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Retracted: Frequent genetic and biochemical alterations of the PI 3‐K/AKT/PTEN pathway in head and neck squamous cell carcinoma
Author(s) -
Pedrero Juana Maria Garcia,
Carracedo Dario Garcia,
Pinto Cristina Muñoz,
Zapatero Agustín Herrero,
Rodrigo Juan Pablo,
Nieto Carlos Suarez,
Gonzalez Maria Victoria
Publication year - 2004
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.20711
Subject(s) - pten , protein kinase b , head and neck squamous cell carcinoma , biology , cancer research , carcinogenesis , point mutation , exon , tumor suppressor gene , microbiology and biotechnology , pi3k/akt/mtor pathway , pathology , gene , cancer , signal transduction , mutation , medicine , genetics , head and neck cancer
Abstract We investigated the status of the PI 3‐kinase/AKT/PTEN signaling pathway in a series of 117 head and neck squamous cell carcinomas (HNSCC) in a search for molecular alterations in genes/proteins with potential prognostic value. For this purpose, PIK3CA and AKT2 gene amplification was assessed by multiplex and Quantitative Real‐Time PCR. Protein expression of AKT, p‐AKT, p110α and PTEN was determined by Western blot. PTEN allelic loss was evaluated by microsatellite analysis. PTEN ‐exon 5 was screened for point mutations by PCR‐SSCP. Homozygous deletions were determined by multiplex PCR. PIK3CA gene was amplified in 43/117 (37%) fresh tumor samples, a frequency that did not differ from that found in archival premalignant tissues: 15/38 (39%); 12/40 (30%) fresh tumors harbored AKT2 gene amplification. AKT was found activated in 6/36 (17%) fresh tumor samples, when compared to their normal tissue counterparts. Of these 6 cases, 1 showed p110α overexpression and 5 displayed PTEN protein downregulation. Neither allelic loss (found in 11/77 informative cases) nor point mutations or homozygous deletions accounted for the reduced PTEN protein expression observed in our tumor series. The histologically normal mucosa of 4 patients displayed some of the molecular alterations analyzed. Dysregulation of the PI 3‐K/AKT/PTEN pathway might contribute to early HNSCC tumorigenesis and might constitute a potential clinical target. Overall, 17/36 (47%) cases showed at least 1 of the molecular alterations studied here, which makes the PI 3‐kinase‐initiated signaling pathway one of the most frequently altered in HNSCC. © 2004 Wiley‐Liss, Inc.