Loss of p63 expression is associated with tumor progression in bladder cancer.

p63, a member of the p53 gene family, encodes multiple proteins that may either transactivate p53 responsive genes (TAp63) or act as a dominant-negative factor toward p53 and p73 (Delta Np63). p63 is expressed in many epithelial compartments and p63(-/-) mice fail to develop skin, prostate, and mammary glands among other defects. It has been previously shown that p63 is expressed in normal urothelium. This study reports that p63 is regulated in bladder carcinogenesis and that p63 expression is lost in most invasive cancers whereas papillary superficial tumors maintain p63 expression. Examination of bladder carcinoma cell lines reveals that certain lines derived from invasive carcinomas maintain expression of Delta Np63, as demonstrated by both immunoblotting and confirmed by isoform-specific quantitative reverse transcriptase-polymerase chain reaction. Another novel finding reported in this study is the fact that p63(-/-) mice develop a bladder mucosa epithelial layer yet fail to complete uroepithelial differentiation, producing a nontransitional default cuboidal epithelium. These data indicate that in contrast to the skin and prostate, p63 is not required for formation of a bladder epithelium but is indispensable for the specific differentiation of a transitional urothelium.

Hürthle cell carcinoma: a 60-year experience.

BACKGROUND: The aim of this study was to define the clinical behavior and prognostic indicators of outcome in Hürthle cell cancer (HCC). METHODS: Diagnosis was confirmed for 56 patients with HCC treated between 1940 and 2000, who form the basis of this study. Primary end points were relapse-free survival (RFS) and disease-specific survival (DSS). Data were analyzed with the Kaplan-Meier method and by log-rank test. RESULTS: The extent of thyroid resection did not predict outcome. Recurrence was a significant predictor of tumor-related mortality. Significant adverse predictors of RFS and DSS were degree of invasion, size >4 cm, extrathyroidal extension, and initial nodal or distant metastases. The most significant predictor of outcome was extent of invasion. Eight-year RFS values for low- and high-risk groups were 100% and 24%. Corresponding rates of 8-year DSS were 100% and 58%. CONCLUSIONS: Widely invasive HCC is an aggressive malignancy that identifies patients who are at high risk for recurrence and tumor-related death. Patients with HCC have a prognosis that is reliably predicted by degree of invasion, tumor size, extrathyroidal disease extension, and initial nodal or distant metastasis. Recurrence portends a poor outcome. High-risk patients and those with recurrence should be considered for adjuvant therapy.

p63 expression profiles in human normal and tumor tissues.

PURPOSE: The p63 gene, located on chromosome 3q27-28, is a member of the p53 gene family. The product encoded by the p63 gene has been reported to be essential for normal development. EXPERIMENTAL DESIGN: In this study, we examined the expression pattern of p63 in human normal and tumor tissues by immunohistochemistry using a monoclonal antibody (clone 4A4) that recognizes all p63 splice variants, and by reverse transcription-PCR using isoform-specific primers. RESULTS: We found that p63 expression was restricted to the nucleus, with a nucleoplasmic pattern. We also observed that the expression was restricted to epithelial cells of stratified epithelia, such as skin, esophagus, exocervix, tonsil, and bladder, and to certain subpopulations of basal cells in glandular structures of prostate and breast, as well as in bronchi. Consistent with the phenotype observed in normal tissues, we found that p63 is expressed predominantly in basal cell and squamous cell carcinomas, as well as transitional cell carcinomas, but not in adenocarcinomas, including those of breast and prostate. Interestingly, thymomas expressed high levels of p63. Moreover, a subset of non-Hodgkin's lymphoma was also found to express p63. Using isoform-specific reverse transcription-PCR, we found that thymomas express all isoforms of p63, whereas the non-Hodgkin's lymphoma tended to express the transactivation-competent isoforms. We did not detect p63 expression in a variety of endocrine tumors, germ cell neoplasms, or melanomas. Additionally, soft tissue sarcomas were also found to have undetectable p63 levels. CONCLUSIONS: Our data support a role for p63 in squamous and transitional cell carcinomas, as well as certain lymphomas and thymomas.