title: The association of PI3 kinase signaling and chemoresistance in advanced ovarian cancer.
abstract: Evidence that the phosphoinositide 3-kinase (PI3K) pathway is deregulated in ovarian cancer is largely based on the analysis of surgical specimens sampled at diagnosis and may not reflect the biology of advanced ovarian cancer. We aimed to investigate PI3K signaling in cancer cells isolated from patients with advanced ovarian cancer. Ascites samples were analyzed from 88 patients, of whom 61 received further treatment. Cancer cells were immunomagnetically separated from ascites, and the signaling output of the PI3K pathway was studied by quantifying p-AKT, p-p70S6K, and p-GSK3β by ELISA. Relevant oncogenes, such as PIK3CA and AKT, were sequenced by PCR-amplified mass spectroscopy detection methods. In addition, PIK3CA and AKT2 amplifications and PTEN deletions were analyzed by FISH. p-p70S6K levels were significantly higher in cells from 37 of 61 patients who did not respond to subsequent chemotherapy (0.7184 vs. 0.3496; P = 0.0100), and this difference was greater in patients who had not received previous chemotherapy. PIK3CA and AKT mutations were present in 5% and 0% of samples, respectively. Amplification of PIK3CA and AKT2 and deletion of PTEN was seen in 10%, 10%, and 27% of samples, respectively. Mutations of PIK3CA and amplification of PIK3CA/AKT2 or deletion of PTEN did not correlate with levels of p-AKT, p-p70S6K, and p-GSK3β. In patients with advanced ovarian cancer, there is an association between levels of p-p70S6K and response to subsequent chemotherapy. There is no clear evidence that this is driven specifically by PIK3CA or AKT mutations or by amplifications or deletion of PTEN.
authors.affiliation: Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutic, The Institute of Cancer Research, Sutton,United Kingdom.
authors.forename: Craig P
authors.initials: CP
authors.lastname: Carden
authors.forename: Adam
authors.initials: A
authors.lastname: Stewart
authors.forename: Parames
authors.initials: P
authors.lastname: Thavasu
authors.forename: Emma
authors.initials: E
authors.lastname: Kipps
authors.forename: Lorna
authors.initials: L
authors.lastname: Pope
authors.forename: Mateus
authors.initials: M
authors.lastname: Crespo
authors.forename: Susana
authors.initials: S
authors.lastname: Miranda
authors.forename: Gerhardt
authors.initials: G
authors.lastname: Attard
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Garrett
authors.forename: Paul A
authors.initials: PA
authors.lastname: Clarke
authors.forename: Paul
authors.initials: P
authors.lastname: Workman
authors.forename: Johann S
authors.initials: JS
authors.lastname: de Bono
authors.forename: Martin
authors.initials: M
authors.lastname: Gore
authors.forename: Stan B
authors.initials: SB
authors.lastname: Kaye
authors.forename: Udai
authors.initials: U
authors.lastname: Banerji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D045744:Cell Line, Tumor; D058534:Class I Phosphatidylinositol 3-Kinases; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D004789:Enzyme Activation / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D017353:Gene Deletion; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging; D009857:Oncogenes; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D016896:Treatment Outcome
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase