Smad7 induces hepatic metastasis in colorectal cancer

S. K. Halder, G. Rachakonda, N. G. Deane, P. K. Datta

Research output: Contribution to journalArticle

63 Scopus citations

Abstract

Although Smad signalling is known to play a tumour suppressor role, it has been shown to play a prometastatic function also in breast cancer and melanoma metastasis to bone. In contrast, mutation or reduced level of Smad4 in colorectal cancer is directly correlated to poor survival and increased metastasis. However, the functional role of Smad signalling in metastasis of colorectal cancer has not been elucidated. We previously reported that overexpression of Smad7 in colon adenocarcinoma (FET) cells induces tumorigenicity by blocking TGF-β-induced growth inhibition and apoptosis. Here, we have observed that abrogation of Smad signalling by Smad7 induces liver metastasis in a splenic injection model. Polymerase chain reaction with genomic DNA from liver metastases indicates that cells expressing Smad7 migrated to the liver. Increased expression of TGF-β type II receptor in liver metastases is associated with phosphorylation and nuclear accumulation of Smad2. Immunohistochemical analyses have suggested poorly differentiated spindle cell morphology and higher cell proliferation in Smad7-induced liver metastases. Interestingly, we have observed increased expression and junctional staining of Claudin-1, Claudin-4 and E-cadherin in liver metastases. Therefore, this report demonstrates, for the first time, that blockade of TGF-β/Smad pathway in colon cancer cells induces metastasis, thus supporting an important role of Smad signalling in inhibiting colon cancer metastasis.

Original languageEnglish (US)
Pages (from-to)957-965
Number of pages9
JournalBritish Journal of Cancer
Volume99
Issue number6
DOIs
Publication statusPublished - Sep 16 2008

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Keywords

  • Immunohistochemistry
  • Liver mets
  • Metastasis
  • Smad7
  • TGF-β1

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Halder, S. K., Rachakonda, G., Deane, N. G., & Datta, P. K. (2008). Smad7 induces hepatic metastasis in colorectal cancer. British Journal of Cancer, 99(6), 957-965. https://doi.org/10.1038/sj.bjc.6604562