Absolute quantification of four isoforms of the class I phosphoinositide-3-kinase catalytic subunit by real-time RT-PCR

Hiroyuki Nakamura, Shingo Dan, Tetsuyuki Akashi, Michiaki Unno, Takao Yamori

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Class I phosphoinositide-3-kinase (PI3K) consists of four isoforms of the catalytic subunit, p110α, -β, -δ and -γ, generated from the genes PIK3CA, -B, -D and -G, respectively. These isoforms show different tissue distribution and some specific and indispensable functions in various biological pathways such as development, inflammation, autoimmunity and malignancy. In human cancers, frequent genomic amplification and gain-of-function mutations of PIK3CA were reported, which suggests an oncogenic potential. However, the role played by the other three isoforms in human cancer remains to be determined. We wanted to investigate the relationship between all the isoforms in human cancers. Here, we have established a system for the simultaneous absolute-quantification of all four isoforms by real-time reverse transcription polymerase chain reaction (RT-PCR). The reliability of this system was confirmed using three main criteria: (i) good correlation of each standard curve, (ii) high specificity of the PCR reactions and (iii) excellent reproducibility. Using this system, we investigated human monocytic leukemia cells (U937) to analyze expression of all four isoforms. The biological implications of the expression level of the four isoforms of class I PI3K catalytic subunit are discussed.

Original languageEnglish
Pages (from-to)1181-1184
Number of pages4
JournalBiological and Pharmaceutical Bulletin
Volume30
Issue number6
DOIs
Publication statusPublished - 2007 Jun 1

Keywords

  • Absolute quantification
  • Phosphoinositide-3-kinase (PI3K)
  • Real-time reverse transcription polymerase chain reaction (RT-PCR)
  • U937

ASJC Scopus subject areas

  • Pharmacology
  • Pharmaceutical Science

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