title: Correlation of PIK3Ca mutations with gene expression and drug sensitivity in NCI-60 cell lines.
abstract: The gene that encodes the alpha-isoform of phosphatidylinositol 3-kinase (PIK3Ca) is frequently mutated in human cancers. We profiled the mutation status of the PIK3Ca gene in the National Cancer Institute (NCI)-60 panel of human cancer cell lines maintained by the Developmental Therapeutics Program of the NCI. Mutation hotspots on the gene were PCR amplified and sequenced, and the trace data were analyzed with software designed to detect mutations. Seven of the cell lines tested have PIK3Ca mutations: two lines derived from breast cancer, two from colon cancer, two from ovarian cancer, and one from lung cancer. BRAF and EGFR genes were normal in the PIK3Ca mutant lines. Two of the cell lines with mutant PIK3Ca also have a mutant version of the KRAS gene. The mutation status was correlated with array-based gene expression that is publicly available for the NCI-60 cell lines. We found increased expression levels for estrogen receptor (ER) and ERBB2 in PIK3Ca mutant lines. The PIK3Ca mutation status was also correlated with compound screening data for the cell lines. PIK3Ca-mutant cell lines were relatively more sensitive than PIK3Ca-normal cell lines to the ER inhibitor tamoxifen and the AKT inhibitor triciribine, among other compounds. The results provide insights into the role of mutant PIK3Ca in oncogenic signaling and allow preliminary identification of novel targets for therapeutic intervention in cancers harboring PIK3Ca mutations.
authors.affiliation: Argus Biosciences, LLC 2623 Barclay Way, Belmont, CA 94002, USA. dwhyte@argusbio.com
authors.forename: David B
authors.initials: DB
authors.lastname: Whyte
authors.forename: Susan L
authors.initials: SL
authors.lastname: Holbeck
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D045744:Cell Line, Tumor; D058534:Class I Phosphatidylinositol 3-Kinases; D004252:DNA Mutational Analysis; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D020869:Gene Expression Profiling; D005787:Gene Frequency; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis* / Q000235:genetics* / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D012263:Ribonucleosides / Q000494:pharmacology / Q000627:therapeutic use; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology; D013629:Tamoxifen / Q000494:pharmacology; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D058534:Class I Phosphatidylinositol 3-Kinases; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases; D012263:Ribonucleosides; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen; D014157:Transcription Factors; C023764:triciribine; C484760:PIK3CA protein, human