involucrin and Uterine-Cervical-Dysplasia

In a recent study of low-grade cervical squamous intraepithelial lesions (SILs), we reported that infection with both low- and high-risk human papillomaviruses (HPVs) upregulated cyclin A, B, E, and Ki67 expression in basal and suprabasal cells. In view of the intricate link between cell cycle exit, proliferation, and differentiation, we examined the morphologic distribution of cytokeratins 13 and 14 and involucrin expression in 49 low-grade SILs infected with HPV types 6, 11, 16, 18, 31, 33, 39, 42, 43, 44, 45, 51, 52, 56, 58, and 66; 2 lesions contained both low- and high-risk HPVs. The findings were compared with 30 high-grade SILs infected with HPV types 16, 31, 33, 51, 58, 66, and 67; 3 of these were infected with 2 different HPVs. In low-grade lesions, the differentiation markers were expressed normally, showing that differentiation proceeds despite upregulation of cell cycle--associated proteins. Loss of involucrin (3 of 33) and cytokeratin 13 (8 of 33) expression occurred only in the high-grade lesions and was therefore related to lesion grade. Loss of cytokeratin 14 expression was also significantly more frequent in high-grade than in low-grade lesions (19 of 33 v 12 of 51; P < .01). In addition, cytokeratin 14 expression was significantly less frequent in the intermediate and superficial layers of low-grade SILs infected with high-risk HPVs than in those infected with low-risk HPVs (3 of 27 v 14 of 24; P < .001). These findings are consistent with in vitro data and suggest that abnormalities of both cell cycle control and squamous differentiation are important in HPV-associated neoplastic transformation.

Topics: DNA, Viral; Female; Humans; Immunoenzyme Techniques; In Situ Hybridization; Keratin-14; Keratins; Papillomaviridae; Papillomavirus Infections; Polymerase Chain Reaction; Protein Precursors; Transcription Factor AP-1; Tumor Virus Infections; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

Cervical intraepithelial neoplasia (CIN) I, II, and III represent a spectrum of premalignant epithelial changes and are ideal targets for application of chemoprevention strategies. Intermediate end point biomarkers are increasingly being used as surrogate end points to monitor clinical chemoprevention trials. To identify potential biomarkers in cervical epithelium, we analyzed the expression of nuclear retinoic acid receptor (RAR) mRNA by in situ hybridization, involucrin, cornifin, and transforming growth factors (TGFs) beta1 and beta2 by immunohistochemistry in cervical specimens, which contained adjacent normal epithelium and CIN lesions from 52 patients. These biomarkers were expressed in all adjacent normal cervical epithelia, whereas all CIN lesions including CIN I, CIN II, and CIN III exhibited decreased expression of RAR-alpha by 55.8%, RAR-beta by 64.7%, RAR-gamma by 54.9%, involucrin by 80.8%, cornifin by 88.5%, TGF-beta1 by 89.7%, and TGF-beta2 by 85.7%. Viewed as a whole, these biomarkers were down-regulated in 100% of the CIN lesions. Because all of these biomarkers can be modulated in vitro by retinoids, they may serve as intermediate biomarkers for retinoid chemoprevention trials in the patients with CIN lesions.

Topics: Biomarkers, Tumor; Cornified Envelope Proline-Rich Proteins; Down-Regulation; Female; Humans; Immunohistochemistry; In Situ Hybridization; Membrane Proteins; Protein Precursors; Receptors, Retinoic Acid; RNA, Messenger; Transforming Growth Factor beta; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

The expression of involucrin, a cytoplasmic protein synthesized during squamous maturation, was assessed by immunocytochemistry in different grades of cervical lesions. In normal/benign cervical epithelium and low-grade squamous intraepithelial lesions [SILS or cervical intraepithelial neoplasia (CIN)-1] involucrin showed intense and homogenous cytoplasmic expression in the spinal layers of 75 and 57% of samples, respectively. The basal cell layers showed no expression of involucrin. In high-grade SILs (CIN-2/3) 40% of the samples showed diffuse and focal cytoplasmic expression of involucrin in the differentiated basaloid cells. In the squamous cell carcinomas (SCCs) analyzed, well-differentiated tumors showed intense focal expression in 61% of the cases, moderately differentiated SCCs showed intense expression in 33% of the cases, while poorly differentiated SCCs (PDSCC) showed only a mild focal expression in 7% of cases. With increasing severity of the lesions, patchy expression of involucrin with a mixture of reactive and nonreactive cells predominated. Patterns of immunocytochemical staining for involucrin in cervical lesions of different grades, from low-grade to high-grade SILs, and invasive carcinoma may be of critical importance, if loss of involucrin expression is used as a criterion for neoplastic transformation in cervical epithelium. Our findings suggest that involucrin may be a sensitive marker in identifying the differentiation status of the lesion while the absence of involucrin in PDSCC may be helpful in differential diagnosis.

Topics: Adult; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Differentiation; Female; Humans; Immunohistochemistry; Middle Aged; Protein Precursors; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

Ninety-three cervical conization specimens with condyloma or intraepithelial neoplasia were stained by the peroxidase-antiperoxidase technique for involucrin. Diffuse, homogeneous suprabasal staining was observed in the ectocervical squamous mucosa and mature squamous metaplasia. In immature squamous metaplasia, staining was limited to cells with apparent squamous differentiation. Although diffusely reactive in the upper layers of condyloma and cervical intraepithelial neoplasia (CIN) grade I, the stain was uneven in the former and lacking in the parabasal layers of the latter. The staining intensity, distribution, and pattern were more variable in CIN grade II and grade III. With increasing severity, a patchy pattern with a mixture of reactive and nonreactive cells predominated. Although immunoreactivity with involucrin could not distinguish immature squamous metaplasia from neoplasia, the staining patterns in CIN correlated with extent of disease, degree of squamous differentiation, and cellular disorganization.

Topics: Carcinoma in Situ; Carcinoma, Squamous Cell; Condylomata Acuminata; Female; Humans; Immunoenzyme Techniques; Protein Precursors; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

Forty-two cervical biopsies with cervical intraepithelial neoplasia were compared with respect to the expression of human papillomavirus (HPV) structural proteins and the expression of the cellular structural protein involucrin, a marker of suprabasal squamous differentiation. HPV structural protein and involucrin expression displayed an inverse correlation with the severity of dysplasia. Both of these proteins were detected in 11 of 28 cases (39%) of mild and moderate dysplasia, but in only two of 14 (14%) cases of severe dysplasia. This difference was statistically significant (p less than 0.001). The presence of HPV was also associated with expression of involucrin in the full thickness of the epithelium, including the basal layer, and an altered staining pattern in the more superficial cells, particularly the koilocytotic cells. These findings support the hypothesis that squamous differentiation is required for the expression of viral structural proteins and that HPV infection begins in the basal epithelium. The study also demonstrates the utility of involucrin staining in differentiating virus-induced cytologic atypia from true neoplasia.

Topics: Adult; Animals; Carcinoma in Situ; Cell Differentiation; Female; Humans; Papillomaviridae; Protein Precursors; Tumor Virus Infections; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms; Viral Proteins; Viral Structural Proteins

Involucrin, a protein subunit of keratinocyte cross-linked envelopes, is a distinctive marker for suprabasal differentiation in stratified squamous epithelium. Immunoperoxidase staining for involucrin was used to evaluate paraffin sections of tissue obtained by colposcopically directed biopsies of infectious, metaplastic, and dysplastic lesions of the cervix and vagina. Areas of normal squamous epithelium, papillary and flat condyloma acuminatum, and mature and immature squamous metaplasia showed positive staining in 99 per cent of samples lacking significant inflammation and in 60 per cent of those with moderate or severe inflammation. In contrast, only 19 per cent of the squamous cell dysplasias, even those without much inflammation, showed positive staining, and no area with moderate or severe inflammation showed positive staining. These findings indicate that expression of involucrin is modulated by cellular pathologic features and microenvironment. We suggest that immunoperoxidase staining for involucrin may be useful in distinguishing mild dysplasia from immature metaplasia and flat condyloma in some biopsy specimens in which routine histologic examination yields an indeterminate diagnosis.

Topics: Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cervix Uteri; Female; Immunoenzyme Techniques; Methods; Protein Precursors; Staining and Labeling; Uterine Cervical Dysplasia; Vagina