Precocious appearance of markers of squamous differentiation in metaplastic cells of human endocervix

Abstract

We used immunoperoxidase methods employing antibodies against involucrin and filaggrin, both markers of squamous terminal differentiation, to study squamous metaplastic transformation in the human endocervix. Expression of involucrin and filaggrin was restricted to squamous metaplastic cells whereas columnar epithelial cells were constantly negative. Immature squamous metaplastic epithelium also showed a positive immunostaining. In mature squamous metaplasia a suprabasal homogeneous staining pattern similar to that found in the exocervical epithelium was detected, although with full-thickness filaggrin immunoreactivity in 45% of cases (P less than 0.05). These results support the hypothesis of an epithelial origin of reserve subcolumnar cells, and suggest that precocious squamous differentiation seems to take place in metaplastic cells of the human endocervix.

Squamous metaplasia amplifies pathologic epithelial-mesenchymal interactions in COPD patients

“…These findings are consistent with the work of others suggesting that SM occurs through the increased recruitment of basal cells into an amplifying population of committed squamous lineage cells (29). This amplifying population occupies the suprabasal layer and expresses involucrin, keratin 6B, and keratin 14, which are known markers of actively proliferating suprabasal cells in normal squamous mucosa, SM either in the lung or other mucosal sites, and the epidermis at the edge of wounds (29,30,(45)(46)(47).…”

Filaggrin, Human Papillomavirus, and the Cervix

“…Lara et al [ 7 ] studied 87 cervical biopsies, classifi ed as either normal cervical epithelium, nonneoplastic lesions, preneoplastic lesions, or neoplastic lesions, and performed fi laggrin protein immunostaining. Non-squamous epithelium, either benign or malignant, showed lack of fi laggrin expression as also demonstrated elsewhere [ 8 ]. As for normal squamous epithelium, they found the aforementioned homogeneous suprabasal pattern.…”

“…Changes in fi laggrin/pro-fi laggrin expression were related to abnormal keratinization rather than to the presence of HPV DNA or type. With regard to the T-zone, Serra et al [ 8 ] showed that fi laggrin was completely absent from the endocervical columnar epithelium, but with diffuse and intense immunoreactivity even in the most immature metaplastic epithelium. In the area of very incipient squamous metaplasia, unnoticed histologically, fi laggrin expression was found to be restricted to the reserve subcolumnar cells, which is thought to play a role in the histogenesis of the T-zone [ 8 , 81 ].…”

Intermediate basal cells of the prostate: In vitro and in vivo characterization

“…Hormonal and growth factor alterations may induce hyperplasia or squamous metaplasia within the prostate basal layer [15,33,34]. To investigate this possibility, PrECs and prostate specimens were stained with an antibody against involucrin, a protein associated with squamous differentiation/metaplasia [27,35]. Formalin-fixed, paraffin-embedded blocks of proliferating PrECs stained strongly for involucrin in vitro ( Fig.…”