Biomedical subjects

Jose A Gomez

Publications and source records attributed to Jose A Gomez.

4 recordsLinked to original sources

PubMed2006

Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis.

Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.

Acetylcysteine↗

PubMed2006

Primary angiosarcoma of the bladder.

CONTEXT: Primary bladder angiosarcomas are extremely rare, and their clinical and pathologic features are not well described. OBJECTIVE: To further refine the clinical features of primary bladder angiosarcomas and define their pathologic spectra. DATA SOURCES: Relevant sources were identified using MEDLINE and a subsequent bibliographic search of all pertinent reports and reviews. We also searched the M. D. Anderson pathology archives. STUDY SELECTION: After excluding 4 cases that likely secondarily involved the bladder, we identified 9 true primary bladder angiosarcomas. DATA EXTRACTION: Data were extracted on the following: demographics, clinical presentation, predisposing factors, gross pathology, microscopic pathology, immunophenotype, therapy, and outcomes. DATA SYNTHESIS: Primary bladder angiosarcomas were found at a mean age of 64.2 years, with a male-female ratio of 8:1. Two cases arose in a postirradiation setting. Primary bladder angiosarcomas typically presented with hematuria and were grossly hemorrhagic, raised masses (mean size, 6.7 cm) of the trigone and/or dome. Histologically, most showed classic anastomosing channels lined by plump hyperchromatic cells, though many showed variant histology such as solid growth and epithelioid cytology. Three (43%) of 7 patients died within a year, but only 1 patient died with evidence of disease. The remaining patients were alive at the time of publication of their respective cases (mean, 22 months). CONCLUSIONS: Primary angiosarcomas of the bladder are typically rare tumors of middle-aged and elderly men that present with locally advanced disease and show a wide histologic spectrum. However, their prognosis may be better than previously thought.

Age Distribution↗

PubMed2003

Allelic loss and tumor pathology in head and neck squamous cell carcinoma.

Allelic loss is a common occurrence in head and neck tumors and has been shown to be an independent predictor of prognosis; however, the relationship between allelic loss and tumor pathology is not well-known. We studied 139 patients who were newly diagnosed with squamous cell cancer of the head and neck to determine whether tumor pathology was correlated with allelic loss at one or more of eight different regions on chromosomes 3p, 5q, 8p, 9p, 10p, 18q, and 21q. At each chromosomal region, loss of heterozygosity at any one of three or four highly polymorphic microsatellite markers that spanned the region in question was considered evidence for allelic loss. A pathologist scored all tumors for seven tumor pathology and host interface parameters. Mean allelic loss across all eight regions was associated with mitotic index (P =.034) and inflammatory response (P =.005). For allelic loss at specific chromosomal regions, the most statistically significant trends were between overall tumor grade and 3p14.2-p13 (P =.014), mitotic index and 3p24.3-p14.3 (P =.026), 9p24.2-p21 (P =.004) and 18q12.3-q23 (P =.009), inflammatory response and 3p14.2-p13 (P =.008) and 9p24.2-p21 (P =.001), desmoplastic response and 9p24.2-p21 (P =.009), and pattern of invasion and 21q21-q22.2 (P =.015). Our results suggest that genes involved in tumor suppression and oncogenesis can potentially be classified based on specific pathologic events in head and neck squamous cell carcinogenesis that they modify.

Carcinoma, Squamous Cell↗

PubMed2002

Malignant melanoma in the palate of a 3-month-old child.

BACKGROUND: Malignant mucosal melanoma of the head and neck is a rare cancer in adults that carries a grave prognosis. Three mucosal melanomas in pediatric patients have previously been reported. METHODS: We present here the youngest case of malignant mucosal melanoma of the head and neck in a 3-month-old boy. He presented with a 2 x 2-mm-pigmented lesion on the anterior maxillary alveolus. The patient was treated with local excision alone. RESULTS: The patient has remained disease free with regular follow-up for 117 months. CONCLUSION: Based upon this case and the few cases reported in the literature, mucosal melanoma is a much less common disease in children than in adults. Further, juvenile mucosal melanoma displays a benign clinical behavior.

Biopsy, Needle↗