Journal Article

Protocadherin LKC, a new candidate for a tumor suppressor of colon and liver cancers, its association with contact inhibition of cell proliferation

Noriko Okazaki, Naomi Takahashi, Shin-ichi Kojima, Yasuhiko Masuho and Hisashi Koga

in Carcinogenesis

Volume 23, issue 7, pages 1139-1148
Published in print July 2002 | ISSN: 0143-3334
Published online July 2002 | e-ISSN: 1460-2180 | DOI: http://dx.doi.org/10.1093/carcin/23.7.1139
Protocadherin LKC, a new candidate for a tumor suppressor of colon and liver cancers, its association with contact inhibition of cell proliferation

More Like This

Show all results sharing this subject:

  • Clinical Cytogenetics and Molecular Genetics

GO

Show Summary Details

Preview

Protocadherins are a major subfamily of the cadherin superfamily, but little is known about their functions and intracellular signal transduction. We cloned a novel human protocadherin gene, containing seven EC domains, and identified functional aspects of this gene. The gene was predominantly expressed in liver, kidney and colon tissues, and was thus designated Protocadherin LKC. The expression of Protocadherin LKC is markedly reduced in cancers arising from these tissues at both transcriptional and protein levels. To investigate the effects of Protocadherin LKC expression in colon cancer, we introduced the gene into colon cancer cell line HCT116, which does not express this gene. Significantly, Protocadherin LKC expression induced contact inhibition of cell proliferation although it did not affect growth rate. When grown to post-confluence in monolayer cells cultures, Protocadherin LKC-expressing HCT116 no longer formed multiple cell layers and showed the typical paving stone morphology of normal epithelial cells. Furthermore, expression of Protocadherin LKC suppressed tumor formation of HCT116 cells in a nude mouse model. In addition, we identified a protein, hMAST205 (microtubule-associated serine/threonine kinase-205 kDa), which interacted with Protocadherin LKC; the interaction occurring between the PDZ domain of hMAST205 and C-terminal tail of Protocadherin LKC. Our results suggest that Protocadherin LKC, which directly binds PDZ protein, is a molecular switch for contact inhibition of epithelial cells in the liver, kidney and colon tissues.

Keywords: MU, mutant; PBS, phosphate-buffered saline; WT, wild-type

Journal Article.  8175 words.  Illustrated.

Subjects: Clinical Cytogenetics and Molecular Genetics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.