Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0154059 (Esophagus)
 2,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sensitivity of cancers to radiotherapy or chemotherapy may be influenced by susceptibility to apoptosis. We evaluated whether expression of three proteins regulating apoptosis, p53, bcl-2, and bax, could predict the effect of radiotherapy in esophageal cancers. We used immunohistochemical staining for these protein regulators of apoptosis to study biopsy specimens obtained from 25 patients with esophageal squamous cell carcinoma before they underwent preoperative radiotherapy. Effectiveness of radiotherapy was assessed by barium esophagography, esophagoscopy, and computed tomography. Radiotherapy was effective in 12 patients and ineffective in 13 patients. Biopsy specimens from the 25 patients showed expression of p53, bcl-2, and bax to be 48.0%, 32.0%, and 76.0% respectively. Effectiveness of radiotherapy was correlated with p53 expression (p = 0.047), but bcl-2 and bax expression showed no relationship to effectiveness of radiotherapy. Expression of p53 protein in biopsy specimens may predict effectiveness of preoperative radiotherapy in esophageal cancers.
Dis Esophagus 2000
PMID:Expression of p53, bcl-2, and bax as predictors of response to radiotherapy in esophageal cancer. 1120 30

Esophageal adenocarcinoma arising on a background of Barrett's esophagus is increasing in incidence. A molecular understanding of both the progression of Barrett's esophagus and the factors determining the response of adenocarcinoma to neoadjuvant therapy is required, and this study focused on the role of proteins regulated by the bcl-2 family of genes, which are important regulators of programmed cell death (apoptosis). In total, 48 patients (36 men, 12 women) with Barrett's adenocarcinoma were studied. All patients received preoperative chemoradiotherapy followed by surgery. Bcl-2, bax and bcl-x protein expression were detected by standard avidin-biotin peroxidase method. Bcl-2, bax and bcl-x expression were detected in 84%, 80%, and 76%, respectively, of normal squamous mucosa. An increasing degree of dysplasia in Barrett's mucosa both before and after chemoradiotherapy was significantly associated with a reduction of bcl-2 expression (P = 0.03 and 0.009, respectively). Bcl-2 expression was significantly associated with tumor differentiation (P = 0.03) and a trend towards earlier T stage (P = 0.08), but not with nodal status. Pre-therapeutic bcl-2, bax and bcl-x protein expression (27%, 75%, and 87.5%, respectively) were not associated with tumor response or resistance to therapy. Bcl-2-positive patients had a significantly improved survival compared with bcl-2-negative tumors. A significant reduction of bcl-2 expression is associated with the progression of Barrett's mucosa to adenocarcinoma. Bcl-2 expression was associated with improved survival. Preoperative chemoradiotherapy induces expression of bax and bcl-x protein. The pretreatment expression of bcl-2 and related proteins did not predict response or resistance to neoadjuvant chemoradiotherapy, suggesting that regulators of apoptosis alone do not determine the response of Barrett's adenocarcinoma to neoadjuvant therapy.
Dis Esophagus 2003
PMID:Loss of Bcl-2 expression in Barrett's dysplasia and adenocarcinoma is associated with tumor progression and worse survival but not with response to neoadjuvant chemoradiation. 1258 Dec 49