PT  - JOURNAL ARTICLE
AU  - PETROS KECHAGIOGLOU
AU  - RIGINI M. PAPI
AU  - XENI PROVATOPOULOU
AU  - ELENI KALOGERA
AU  - ELLI PAPADIMITRIOU
AU  - PETROS GRIGOROPOULOS
AU  - APHRODITI NONNI
AU  - GEORGE ZOGRAFOS
AU  - DIMITRIOS A. KYRIAKIDIS
AU  - ANTONIA GOUNARIS
TI  - Tumor Suppressor PTEN in Breast Cancer: Heterozygosity, Mutations and Protein Expression
DP  - 2014 Mar 01
TA  - Anticancer Research
PG  - 1387--1400
VI  - 34
IP  - 3
4099  - http://ar.iiarjournals.org/content/34/3/1387.short
4100  - http://ar.iiarjournals.org/content/34/3/1387.full
SO  - Anticancer Res2014 Mar 01; 34
AB  - Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is one of the most frequently mutated human tumor suppressor genes, implicated in cell growth and survival and suppressing tumor formation. Loss of PTEN activity, either at the protein or genomic level, has been related to many primary and metastatic malignancies including breast cancer. The present study investigates the heterozygosity, mutation spectrum and protein expression of PTEN in 43 patients with breast cancer or precursor lesions of the breast and 10 healthy individuals. Microsatellite analysis at the PTEN locus using D10S215, D10S541 and D10S579 markers indicated that the observed heterozygosity (Ho) is lower than the expected heterozygosity (Hs) in benign and malignant breast disease. Mutational analysis in exons 1, 5, 7 and 9 of the PTEN gene revealed several mutations, most of which cause truncation of the PTEN protein and consequently loss of activity. Increased circulating levels of PTEN and phosphorylated PTEN protein were also observed by immunostaining in patients with breast cancer and precursor breast lesions. In support, increased PTEN protein expression was detected in corresponding tissue specimens. Our data suggest an association between breast cancer and PTEN mutations, resulting in the production of truncated forms of the corresponding protein, thus indicating that breast carcinogenesis is potentially related to PTEN loss of activity rather than loss of expression. Peripheral blood sampling may provide an advantageous application for the determination of PTEN gene mutations and its protein expression in human cancer.