Abstract. Oncogene-induced senescence (OIS) may be a response to oncogenic activation, acting as a natural barrier against carcinogenesis at a premalignant stage. Thus, numerous cells in premalignant lesions enter senescence, but none or few in malignant tumours. This event could be due to the loss of senescence pathway effectors, including p16 (INK4a)-pRb or ARF-p53. The aim of this study was to characterize and compare the expression of certain senescent markers between oral precancer and cancer tissue samples. The expression of cyclin D1, Rb, maspin, p53 and mouse double minute 2 (MDM2) was analyzed in 20 paraffin-embedded tissue samples of normal oral mucosa (NOM), 14 samples of oral leukoplakia without dysplasia (OLD-), 11 samples of leukoplakia with dysplasia (OLD+) and 15 samples of oral squamous cell carcinoma (OSCC) by immunohistochemistry in tissue arrays. The expression of p16-pRb pathway markers, cyclin D1, maspin and Rb, was more frequent in OLD+ samples than in OSCC samples, although a statistical significance was only observed for maspin (P=0.036). Cyclin D1 expression was also significantly more frequent in OLD-samples vs. NOM samples. For the ARF-p53 pathway, the expression of p53 and MDM2 was significantly more frequent in the OLD-samples compared to in the NOM ones. These findings may indicate a role for cellular senescence in oral carcinogenesis, considering maspin as a reliable senescence marker and prognostic factor in oral premalignant lesions.
We studied 44 cases of small cell bladder carcinoma (SCBC) and 2 cases of large cell neuroendocrine bladder carcinoma (LCNBC) to determine the immunohistochemical profile and biologic behavior. Thyroid transcription factor (TTF)-1, cytokeratin (CK)20, chromogranin A (CgA), synaptophysin, neuron-specific enolase (NSE), and Leu-7 studies were performed. TTF-1+ cases were stained for surfactant protein A (SP-A). The immunohistochemical profile for 44 SCBC cases was as follows: TTF-1+, 11 (25%); CK20+, 3 (7%); CgA+, 13 (30%); synaptophysin+, 22 (50%); NSE+, 35 (80%); and Leu-7+, 30 (68%), and for 2 LCNBC cases was as follows: TTF-1+, 2 (100%); CgA+, (50%); synaptophysin+, 1 (50%); NSE+, 2 (100%); and Leu- 7+, 2 (100%). All cases with TTF-1 expression were negative for SP-A, except 1 case. This case was a mixed SCBC with TTF-1 expression in the urothelial component, which also expressed SP-A. Immunohistochemical markers were not associated with survival. The prognosis of SCBC is relatively better than its pulmonary counterpart. LCNBC seems to be a rarely recognized entity. TTF-1 expression is not limited to small cell lung carcinoma.
The cellular proteome shows a dynamic profile and is subjected to changes in response to various stimuli and disease progression. Lung cancer remains the leading cause of cancer death in industrialized countries. In an attempt to find new disease markers, patients suffering from lung carcinoma have been selected to achieve differential protein expression patterns between normal and neoplasic tissue. After two-dimensional electrophoresis, the spots of interest were digested and identified by matrix-assisted laser desorption/ionization (MALDI) peptide mass fingerprinting. This information will provide a more comprehensive understanding of the disease progression and might constitute a method to complement histopathological diagnosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.