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General Comment |
Wu et al 2003 reported that BNF-1 is a novel gene encoding a putative extracellular matrix protein, is
overexpressed in tumor tissues.
In an effort to identify novel genes relevant to tumor angiogenesis, we compared the genes
expressed in a matched pair composed of vascularized breast tumor and its adjacent normal tissue
obtained from the same cancer patient. Using differential display, we identified a cDNA fragment
that was reproducibly upregulated in vascularized breast tumor. Up-regulation of this gene fragment
in vascularized breast tumor was further verified by semi-quantitative PCR on the same RNA pair
using gene-specific primers. The cDNA encoding the full-length ORF of that gene was then cloned
by both 3' and 5' RACE. Sequence analysis showed that this gene encodes an ORF of 1353 bp
having a hydrophobic N-terminal signal sequence and a cleavage site. We named this novel gene
BNF-1 (breast tumor novel factor 1). The mature protein of this gene contains cysteine-rich repeats
that are a specific feature of several extracellular matrix proteins including thrombospondin-1,
thrombospondin-2, pro-collagen type 1, and von Willebrand Factor 1. PCR analysis of BNF-1
expression in a variety of human adult normal tissues revealed that BNF-1 is expressed
predominantly in liver, heart, prostate, testis, and ovary. To further study the expression pattern of
this novel gene in tumor tissues, we extended our analysis to additional matched pairs of tumor
tissues obtained from breast, lung, and colon cancer patients. We show here that BNF-1 is
over-expressed not only in breast tumors but also in lung and colon tumors.
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