The putative ovarian tumour marker gene HE4 (WFDC2), is expressed in normal tissues and undergoes complex alternative splicing to yield multiple protein isoforms.
The whey acidic protein (WAP) domain is a conserved motif, containing eight cysteines found in a characteristic 4-disulphide core arrangement, that is present in a number of otherwise unrelated proteins. WAP motifs are present in SLPI and elafin, two antiproteinases located on chromosome 20q12-13, in a locus rich in poorly characterized WAP domain proteins. One of these proteins, which contains two WAP domains, is HE4 (also known as WFDC2), originally described as an epididymis specific protein but more recently suggested to be a putative serum tumour marker for ovarian cancer. We have shown that HE4 is expressed in a number of normal human tissues outside of the male reproductive system, including regions of the respiratory tract and nasopharynx, as well as in a subset of lung tumour cell lines. Comparison of multiple HE4 cDNAs and RT-PCR products with genomic sequence allowed the elucidation of the genomic organization. These studies revealed that HE4 can undergo a complex series of alternative splicing events that can potentially yield five distinct WAP domain containing protein isoforms. These results cast doubt on the potential role of HE4 as a serum tumour marker specific for ovarian cancer and open the door to understanding the function of multiple WAP domain containing protein isoforms arising from a single gene.
Bingle
Lynne
L
Respiratory Medicine Unit, Division of Genomic Medicine, University of Sheffield Medical School, Sheffield S10 2RX, UK.
Singleton
Vanessa
V
Bingle
Colin D
CD
D017398:Alternative Splicing / Q000235:genetics*; D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000235:genetics*; D002352:Carrier Proteins / Q000378:metabolism; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics; D030501:Epididymal Secretory Proteins / Q000235:genetics*; D005091:Exons; D005260:Female; D005656:Fungal Proteins / Q000378:metabolism; D006801:Humans; D007438:Introns; D008168:Lung / Q000378:metabolism; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics*; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000378:metabolism; D053481:Secretory Leukocyte Peptidase Inhibitor; D017386:Sequence Homology, Amino Acid; D023083:beta-Defensins
D014408:Biomarkers, Tumor; D002352:Carrier Proteins; C426184:DEFB126 protein, human; D030501:Epididymal Secretory Proteins; D005656:Fungal Proteins; D020033:Protein Isoforms; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor; D023083:beta-Defensins