To investigate the expression of human papillomavirus type 16 (HPV-16) E5 p
rotein in squamous neoplastic changes in the uterine cervix, the specific E
5 antibody was generated and used to identify the expression of E5 protein
in 40 cases of HPV-16-positive tissues and 5 previously identified HPV-nega
tive normal cervical tissues. The results revealed that E5 protein was prim
arily expressed in the lower third of the epithelium in low-grade squamous
intraepithelial lesions (SILs) and throughout the whole epithelium in high-
grade SILs. In invasive squamous carcinoma, 60% of HPV-16-infected cancers
which contained the episomal viral genome had the E5 gene, and could expres
s E5 protein which was located throughout the whole epithelium. Previously,
we documented the expression of type I growth factor receptors [ERBB1/EGFR
(epidermal growth factor receptor), ERBB2, ERBB3 and ERBB4] in the full ra
nge of cervical neoplasias by immunohistochemistry assay. Hence, in this st
udy, we extensively analyzed the correlation between the expression of E5 p
rotein and the expression of type I growth factor receptors. Among 40 HPV-1
6-infected cervical neoplasias, we found that the expression of E5 protein
was significantly correlated with either the expression of the ERBB1 or the
ERBB4 receptor.