CHARACTERIZATION OF KERATIN AND CELL-CYCLE PROTEIN EXPRESSION IN CELL-LINES FROM SQUAMOUS INTRAEPITHELIAL LESIONS PROGRESSING TOWARDS A MALIGNANT PHENOTYPE

Two cell lines derived from vaginal intraepithelial neoplasias (VAINs) expressing human papillomavirus (HPV) 33 (VAIN I, UT-DEC-1) and 16 (V AIN II, UT-DEC-2) E6-E7 mRNA were studied in organotypic culture for t heir keratins and cell cycle regulatory proteins in relation to replic ative aging. Early-passage UT-DEC-1 and UT-DEC-2 cells reproduced epit helial patterns consistent with VAIN, Cells from later passages resemb led full-thickness intraepithelial neoplasia (UT-DEC-1) and microinvas ive cancer (UT-DEC-2), The morphological changes were compatible with these cell lines' ability for anchorage-independent growth at later pa ssages. Simple epithelial keratins were aberrantly expressed in both c ell lines. K18 (absent in normal vaginal keratinocytes) and K17 expres sion increased in UT-DEC-1 and UT-DEC-2 cells at late passages. No mar ked differences in expression of p53 (wild type in both cell lines), m dm-2 or PCNA were detected in parallel with progression. The expressio n of p21(WAF1/Cp1) localized mostly to the upper half of the epitheliu m at early passage and was more intense in the HPV 16-positive UT-DEC- 2 cell line expressing K10. In Northern blot analyses, the transcripti on pattern of the HPV 33 E6-E7 of the UT-DEC-1 cell line changed durin g later passages, whereas that of the HPV 16 E6-E7 of the UT-DEC-2 cel l line remained unaltered. The present characterization of the phenoty pe of these cell lines derived from natural squamous intraepithelial l esions shows an association between simple epithelial-type keratin exp ression and progressive changes in growth and morphology, but fails to demonstrate consistent changes in the expression of cell cycle regula tory proteins studied in parallel with progression.