Expression of candidate chromosome 3p21.3 tumor suppressor genes and down-regulation of BLU in some esophageal squamous cell carcinomas

Received 22 February 2005; received in revised form 21 March 2005; accepted 22 March 2005.

Abstract

The expression of six chromosome 3p21.3 candidate tumor suppressor genes (BLU, FUS2, HYAL2, NPRL2, RASSF1A, and SEMA3B) in esophageal squamous cell carcinoma (ESCC) has been investigated. Reduced expression of BLU was detected in some ESCC cell lines and tumor tissues and the difference was quantitated by real-time quantitative polymerase chain reaction. Methylation specific-PCR revealed the down-regulation of BLU by epigenetic inactivation. However, exogeneous expression of BLU did not functionally suppress tumorigenicity in nude mice. These results suggest that over-expression of BLU alone is not sufficient to inhibit tumorigenicity. Further studies on BLU interacting proteins are required to elucidate the possible role of BLU in the development of ESCC.

Keywords: 3p21.3, BLU, Esophageal squamous cell carcinoma, Tumorigenicity

a Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (SAR), People's Republic of China

b Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong (SAR), People's Republic of China

c Basic Research Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD, USA

d Laboratory of Immunobiology, National Cancer Institute, Frederick, MD, USA

e Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, CA, USA

Corresponding author. Tel.: +852 2358 7307; fax: +852 2358 1559.

PII: S0304-3835(05)00288-0

doi:10.1016/j.canlet.2005.03.036

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