Showing papers on "Skin Carcinoma published in 2001"

Squamous carcinoma in a major salivary gland: a review of the diagnostic considerations.

Abstract: Context.—Squamous carcinoma in a major salivary gland has several possible sources: (1) high-grade mucoepidermoid carcinoma, (2) metastasis or direct invasion from a primary skin carcinoma, (3) metastasis from a distant primary carcinoma, or (4) a primary malignant neoplasm. The latter is conventionally regarded as a diagnosis of exclusion after a history of squamous carcinoma elsewhere has been obtained or there is a positive mucin stain. Design.—Eleven cases of squamous carcinoma in a major salivary gland are presented and the literature reviewed. Results.—Two cases, 1 metastatic from a histologically identical squamous carcinoma from the ipsilateral tonsil and 1 with in situ squamous carcinoma in a duct, demonstrated positive mucicarmine stains. Two cases were high-grade mucoepidermoid carcinomas, also with positive mucin stains. Five cases represented metastases from cutaneous squamous carcinomas. Only 2 cases were regarded as primary carcinomas. There were no histologic clues as to correct s...

Telomerase activity in Kaposi's sarcoma, squamous cell carcinoma, and basal cell carcinoma.

Abstract: Patients with acquired immune deficiency syndrome (AIDS) often develop Kaposi's sarcoma (KS), an unusual skin tumor. The malignant nature of KS has long been disputed. Telomerase activity that maintains telomere length and ensures chromosomal stability, a frequently appearing marker in human malignancies, has been proposed to play a critical role in supporting continued cell growth, hence formation of tumors. We examined telomerase activity in tissue extracts from 22 KS, 10 squamous cell carcinoma (SCC), and 22 basal cell carcinoma (BCC) using the telomeric repeat amplification protocol (TRAP). All of the tumor tissues were previously cryopreserved at -80 degrees C. In this study, all tumor samples tested were positive for telomerase activity. Consistent with the presence of the enzyme activity, the skin tumors had relatively long telomeres. Inhibitors in the tissue extracts of some samples needed to be diluted or extracted by phenol before the enzyme activity was detected in the TRAP assay. All KS as well as two other skin carcinoma samples revealed positive telomerase activity. Our finding supports telomerase's role in tumor cell immortality and suggests the true neoplastic nature of KS.

Role of intracellular interleukin-1 receptor antagonist in skin carcinogenesis.

Abstract: Interleukin 1 (IL-1) is a major mediator of inflammation and exerts pleiotropic effects on many systems. To elucidate the role of its endogenous inhibitor, intracellular IL-1 receptor antagonist (icIL-1Ra), in mouse skin, we produced an icIL-1Ra-overexpressing skin carcinoma cell line (icIL-1Ra-JWF2). Altered expression of icIL-1Ra did not change IL-1alpha mRNA levels in these transfected cells. In icIL-1Ra-JWF2 cells, however, cyclooxygenase-2 mRNA levels were dramatically reduced and shown to be transcriptionally regulated by icIL-1Ra. To determine the effect of icIL-1Ra on cell proliferation, cell counts were done 24 h after plating equal numbers of cells. Cells from three icIL-1Ra-JWF2 clones showed significantly reduced growth rates compared with parental JWF2 cells. We subcutaneously injected five independent clones of icIL-1Ra-JWF2 cells into nude mice and measured the tumor doubling time by weekly measurements of tumor volume. IcIL-1Ra appeared to significantly slow the growth of tumors in vivo. Collectively these observations suggest that IL-1Ra has antiproliferative effects in murine skin carcinoma cells.

Divergence between the high rate of p53 mutations in skin carcinomas and the low prevalence of anti-p53 antibodies

Abstract: Circulating anti-p53 antibodies have been described and used as tumoural markers in patients with various cancers and strongly correlate with the p53 mutated status of the tumours. No study has yet looked at the prevalence of such antibodies in skin carcinoma patients although these tumours have been shown to be frequently p53 mutated. Most skin carcinoma can be diagnosed by examination or biopsy, but aggressive, recurrent and/or non-surgical cases' follow up would be helped by a biological marker of residual disease. We performed a prospective study looking at the prevalence of anti-p53 antibodies using an ELISA technique in a series of 105 skin carcinoma patients in comparison with a sex- and age-matched control skin carcinoma-free group (n = 130). Additionally, p53 accumulation was studied by immunohistochemistry to confirm p53 protein altered expression in a sample of tumours. Anti-p53 antibodies were detected in 2.9% of the cases, with a higher prevalence in patients suffering from the more aggressive squamous cell type (SCC) of skin carcinoma (8%) than for the more common and slowly growing basal cell carcinoma type or BCC (1.5%). p53 protein stabilization could be confirmed in 80% of tumours studied by IHC. This low level of anti-p53 antibody detection contrasts with the high rate of p53 mutations reported in these tumours. This observation shows that the anti-p53 humoral response is a complex and tissue-specific mechanism.

Method for detecting carcinoma

Abstract: PROBLEM TO BE SOLVED: To utilize a protein bearing an important role on the long term survival of the cranial nerves cell and a DNA encoding the protein on the detection of carcinoma. SOLUTION: The detection of carcinoma, e.g. large bowel carcinoma, skin carcinoma or the like, is carried out by using the DNA encoding the bradion protein or its analogue derived from human beings and the antibody immunoreactive with the protein or its analogue.