Cervical intraepithelial neoplasia (CIN) represents a spectrum of preinvasive squamous
lesions within the cervical epithelium, whose identification is a diagnostic challenge
due to subtle histomorphological differences among its categories. This study explores
ORF1p, a nucleic acid-binding protein derived from long interspersed nuclear element-1
(LINE-1), as a potential biomarker for enhancing CIN diagnosis. A comprehensive analysis
of 143 cervical specimens, encompassing CIN I (n=20), CIN II (n=46), CIN III (n=14),
invasive cancer (n=32), and nondysplastic cases (normal cervical epithelia (n=24)
and atrophy (n=7) were conducted. ORF1p, Ki67, and p16 expressions were evaluated
using immunohistochemistry. ORF1p immunopositivity was detected in the vast majority
[110/112 (98.2%)] of dysplastic and neoplastic (CIN and invasive cancer) specimens,
whereas 19/24 (79.2%) of normal cervical specimens lacked ORF1p expression. The observed
pattern of ORF1p expression showed a progressively increasing extent and intensity
with advancing CIN grades. CIN I exhibited mild ORF1p expression in the lower one
or two-thirds of the cervical epithelium [14/16 (87.5%)], whereas CIN II demonstrated
moderate to strong ORF1p expression spanning the lower two-thirds [29/46 (63.0%)].
Pronounced transepithelial ORF1p immunopositivity characterized CIN III cases [13/14
(92.8%)] and cervical cancer [30/32 (93.8%)]. These findings propose ORF1p as a valuable
indicator even for detecting CIN I, effectively discerning them from normal cervical
tissue (p < 0.0001). Our findings underscore the potential of ORF1p as an early diagnostic
marker for cervical neoplasia.
