Modulation of CDK2-AP1 (p12DOC-1) expression in human colorectal cancer

Ziquan Yuan, Anu G. Gaba, Tara Sotsky Kent, Anna Bennett, Agnes Miller, Thomas K. Weber

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

We have previously demonstrated an association between microsatellite instability and decreased CDK2-AP1 (p12DOC-1) expression in human colorectal cancer (CRC) cell lines. In those same studies, induction of CDK2-AP1 expression promoted both cell cycle arrest and apoptosis. The goals of our present study were to better understand the mechanisms leading to reduced CDK2-AP1 expression in microsatellite unstable (MSI) CRC and to study further the effect of CDK2-AP1 modulation on cell proliferation and apoptosis utilizing RNA interference (RNAi) techniques. We used direct sequencing to screen for mutations of the poly (T)8 microsatellite-like region in the 3′ end of the CDK2-AP1 gene in 24 CRC cell lines. We then utilized an in vitro human mismatch repair (MMR) recombinant system to assess for correction of the mutation and changes in CDK2-AP1 expression secondary to hMLH1 transfection. We also investigated the effect of CDK2-AP1 modulation in four settings: (1) native CDK2-AP1 absence, (2) endogenous CDK2-AP1 expression, (3) RNAi-induced CDK2-AP1 inhibition and (4) induced CDK2-AP1 over expression. The mutation - del T poly (T)8 - at the 3′ end of the CDK2-AP1 gene was found in 3/12 (25%) of MSI CRC cell lines, but in none of the microsatellite stable samples (0/12). Interestingly, when wild-type MMR protein - MLH1 - was induced in an in vitro human recombinant system, the del T poly (T)8 mutation was reversed and CDK2-AP1 expression increased. RNAi-mediated CDK2-AP1 inhibition was associated with decreased apoptosis and increased cell proliferation in CDK2-AP1-non deficient CRC cell lines. We conclude that mutations in the microsatellite-like sequence of the CDK2-AP1 gene in MSI CRC are associated with decreased CDK2-AP1 expression. In addition, modulation of CDK2-AP1 expression in human CRC alters cell proliferation and apoptosis.

Original languageEnglish (US)
Pages (from-to)3657-3668
Number of pages12
JournalOncogene
Volume24
Issue number22
DOIs
StatePublished - May 19 2005

Keywords

  • CDK2-AP1
  • Colorectal cancer
  • Microsatellite instability
  • siRNA

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research

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    Yuan, Z., Gaba, A. G., Kent, T. S., Bennett, A., Miller, A., & Weber, T. K. (2005). Modulation of CDK2-AP1 (p12DOC-1) expression in human colorectal cancer. Oncogene, 24(22), 3657-3668. https://doi.org/10.1038/sj.onc.1208378