RT Journal Article SR Electronic T1 Genetic Alterations in the PI3K Pathway in Prostate Cancer JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 1739 OP 1743 VO 29 IS 5 A1 XIUJU SUN A1 JIAN HUANG A1 TAKU HOMMA A1 DAISUKE KITA A1 HELMUT KLOCKER A1 GEORG SCHAFER A1 PETER BOYLE A1 HIROKO OHGAKI YR 2009 UL http://ar.iiarjournals.org/content/29/5/1739.abstract AB Alterations in the PIK3CA and PTEN genes were assessed in 40 prostate tumors (radical prostatectomy samples). Genetic analyses in glands of the highest Gleason pattern within each tumor revealed PIK3CA amplification in 13%, PIK3CA mutations in 3%, PTEN homozygous deletion in 13% and PTEN hemizygous deletion in 8% of the cases analyzed. Supporting the view that PTEN and PIK3CA act in the same PI3K signaling pathway, genetic alterations in the PIK3CA and PTEN genes were mutually exclusive, except in one tumor. Overall, 13 of the 40 (33%) prostate tumors had alterations in the PI3K pathway. For cases with genetic alterations, other tumor areas with lower Gleason patterns as well as non-tumorous prostate glands were also analyzed. Of nine tumors with Gleason score 7, five cases contained the same genetic alterations in tumor areas of Gleason patterns 3 and 4, whereas in another four cases, genetic alterations were detected only in tumor areas of Gleason 4 but not Gleason 3 patterns. There were no alterations in non-tumorous glands. These results suggest that genetic alterations in the PI3K pathway are common in prostate cancer, and occur mainly through PIK3CA amplification and PTEN hemizygous or homozygous deletion. Glands of Gleason pattern 3 are genetically heterogeneous, some containing the same genetic alterations observed in glands of Gleason pattern 4.