TY - JOUR
TI - Phosphatidylinositol 3′-kinase catalytic subunit α gene amplification contributes to the pathogenesis of mantle cell lymphoma
AU - Psyrri, A.
AU - Papageorgiou, S.
AU - Liakata, E.
AU - Scorilas, A.
AU - Rontogianni, D.
AU - Kontos, C.K.
AU - Argyriou, P.
AU - Pectasides, D.
AU - Harhalakis, N.
AU - Pappa, V.
AU - Kolialexi, A.
AU - Economopoulou, C.
AU - Kontsioti, F.
AU - Maratou, E.
AU - Dimitriadis, G.
AU - Economopoulou, P.
AU - Economopoulos, T.
JO - Clinical Cancer Research
PY - 2009
VL - 15
TODO - 18
SP - 5724-5732
PB - 
SN - 1078-0432
TODO - 10.1158/1078-0432.CCR-08-3215
TODO - 2 morpholino 8 phenylchromone;  phosphatidylinositol 3 kinase;  phosphatidylinositol 3,4,5 trisphosphate 3 phosphatase;  protein kinase B;  2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one;  chromone derivative;  morpholine derivative, alpha chain;  article;  cancer growth;  catalysis;  controlled study;  flow cytometry;  fluorescence in situ hybridization;  gene amplification;  genetic transcription;  human;  human cell;  immunohistochemistry;  mantle cell lymphoma;  pathogenesis;  priority journal;  protein expression;  real time polymerase chain reaction;  somatic mutation;  Western blotting;  apoptosis;  chemistry;  drug effect;  enzyme active site;  enzymology;  genetics;  metabolism;  pathology;  reverse transcription polymerase chain reaction;  tumor cell line, 1-Phosphatidylinositol 3-Kinase;  Apoptosis;  Catalytic Domain;  Cell Line, Tumor;  Chromones;  Gene Amplification;  Humans;  Lymphoma, Mantle-Cell;  Morpholines;  Reverse Transcriptase Polymerase Chain Reaction
TODO - Purpose: Activation of phosphatidylinositol 3′-kinase pathway is implicated in the pathogenesis of mantle cell lymphoma (MCL). The genetic change in phosphatidylinositol 3′-kinase catalytic subunit α (PIK3CA) in MCL has not been identified. Experimental Design: Thirty-five primary MCL cases and 2 MCL cell lines (GRANTA-519 and Rec-1) were used to investigate somatic mutation and gene copy number of PIK3-CA. Gene copy number was determined using quantitative real-time PCR and fluorescence in situ hybridization. We used quantitative real-time reverse transcription-PCR to measure PIK3CA transcription levels. Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and phoshorylated AKT protein levels were analyzed using Western blotting and immunohistochemistry. Flow cytometry was used to assess apoptosis after treatment of MCL cell lines and one control cell line with LY294002, a specific inhibitor of PI3KCA. Results: Fifteen of 22 (68%) MCL cases and the MCL cell lines harbored a gain (≥3) of PIK3CA gene copy number. In addition, cases withincreased PIK3CA gene copy number had elevated PIK3CA mRNA levels. Furthermore, amplification of PIK3CA correlated with the status of AKT phosphorylation in 7 of 12 (58%) primary MCL cases. Inhibition of PIK3CA induced increased apoptosis in the MCL cell lines. PTEN protein expression was present in all 14 primary MCL cases and cell lines by Western blotting, whereas 5 of 33 (15%) cases tested by immunohistochemistry had loss of PTEN expression. Conclusions: We conclude that a gain of gene copy number of PIK3CA is frequent genetic alteration that contributes to MCL progression. PIK3CA is a promising therapeutic target in MCL. © 2009 American Association for Cancer Research.
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