Aberrant expression of p53 tumour-suppressor protein in non-melanoma skin cancer

Expression of the cellular p53 tumour-suppressor protein was examined in 78 epidermal tumours, including basal and squamous cell carcinomas, keratoacanthomas, solar keratoses, Bowen's disease and viral warts. An immunohistochemical study was employed using the antibody CM-1, raised against recombinant human p53 protein. Positive staining for p53, not detectable in normal cells because wild-type p53 is rapidly degraded, reflects abnormal stabilization of p53 protein, and in many cases suggests p53 gene mutation. p53 immunoreactivity was not observed in normal skin or in viral warts. In contrast, positive staining for CM-1 was seen throughout the tumour in the majority of basal and squamous cell carcinomas and in Bowen's disease. Immunoreactivity to p53 was also observed in the majority of keratoacanthomas and solar keratoses, but was confirmed to areas of dysplastic basal epithelium. This study demonstrates that accumulation of p53 protein, suggestive in many cases of p53 gene mutation and hence loss of tumour-suppressor function, may occur as an important early step in the development of diverse epidermal cancers.

Expression of high-affinity laminin receptor mRNA correlates with cell proliferation rather than invasion in human papillomavirus-associated cervical neoplasms

Induction of the expression of the Mr 67,000 high-affinity laminin receptor gene has been postulated as playing a role in the progression of human tumors to invasive cancers. We tested this hypothesis by examining histopathological sections of a large number of epithelial lesions of the genital tract associated with human papillomaviruses. In situ hybridization was performed with a riboprobe generated from a laminin receptor complementary DNA. Laminin receptor mRNA was expressed primarily in the less differentiated cells in normal squamous tissues and in a spectrum of squamous neoplasms. There was no net induction of mRNA per cell in intraepithelial or invasive squamous neoplasms relative to normal tissue. In contrast, laminin receptor mRNA was not expressed at a detectable level in normal glands of the uterine cervix but was dramatically induced in morphologically abnormal, human papillomavirus-positive glands, irrespective of the genotype of human papillomaviruses present. The induction occurred before any evidence of invasion, and there was no further increase during the transition from adenocarcinoma in situ to invasive carcinoma. We conclude that induction of high-affinity laminin receptor gene expression is associated with the development of malignancies of cervical glandular epithelia, but the increased expression appears to correlate with the proliferative rather than the invasive properties of these cells.

[Detection of human papillomavirus antigens in papillomatous lesions of the palate]

The presence of human papillomavirus antigen was studied in palate papillomas and in verruca vulgaris located in the palate using the Peroxidase-Antiperoxidase immunohistochemical methods. The antigens were detected only in the nuclei of cells of the stratum granulosum and stratum corneum in some cases of verruca vulgaris but not in any case of palate papillomas.

[Human papilloma virus and pathology of the oral cavity]

The human papillomavirus (HPV) causes a variety of cutaneous warts and proliferative squamous lesions of oral mucosa. This article reviews, on the basis of the literature and personal observations, the biology of HPV and its etiopathogenetic role in some uncommon oral diseases.

Oral warty dyskeratoma

An elderly woman had a small verrucose hyperkeratotic papule on the hard palate. Histologic examination showed the lesion to be a warty dyskeratoma. Warty dyskeratoma may represent an abnormal keratinization response to intraoral trauma or inflammation. All eight previously reported cases are reviewed. Clinically, the lesions appeared as verrucose hyperkeratotic papules or as focal mucosal depressions, sometimes filled with keratin. Eight of nine lesions were located on the hard palate or on an alveolar ridge.

Warty dyskeratoma. A note concerning its occurrence on the oral mucosa, and its possible pathogenesis

A case of warty dyskeratoma occurring in the oral mucosa is presented. Indirect immunofluorescence tests using the patient's serum showed the presence of IgG class antibodies reactive with intercellular material of guinea-pig lip mucosa and IgM class antinuclear antibodies. The patient did not have any clinical histopathological, haematological or serological evidence of other autoimmune disease.

[Verrucous type of Thomson's syndrome. A contribution to the congenital poikilodermias]

A case of a verrucous type of Thomson's syndrome in a 12 year old boy is presented. The verrucous type is discussed as a prognostically serious form of Thomson's syndrome, because of tendency to malignant degeneration. A review of the literature is given.