RESUMEN

AIM: To further understand the molecular basis for gastric cardia carcinogenesis and to provide etiological clues. METHODS: Endoscopic mucosa biopsy and histopathological examinations were made on 37 subjects from a high incidence area for both esophageal and gastric cardia carcinomas in northern China. All the biopsy samples were fixed in 850 ml. (-1)L alcohol and embedded in paraffin. Each block contained one piece of tissue and was serially section at 5 microm. Immunohistochemistry (ABC) was carried out on these gastric cardia samples to determine the alterations of p16 and Rb. RESULTS: Based on the histopathlogical examination there were 11 cases of chronic superficial gastritis, 12 cases of chronic atrophic gastritis and 14 cases of dysplasia. The immunostaining demonstrated different levels of unclear immunostaining of p16 and Rb in normal gastric cardia tissue and the tissues with different severity of lesions. With the lesions progressing, the positive immunostaining rates for p16 protein had a decreasing tendency. In contrast, the positive immunostaining rate for Rb protein had an increasing tendency. There was a significant negative relationship between the two parameters. Changes of p16 was CSG 11(100%), CAG 7(58%), DYS 4(29%) and changes of Rb was CSG 2(18%), CAG 8(67%) and DYS 12(86%), (P<0.05). CONCLUSION: The alterations of p16 and Rb protein may play a role in the early stages of gastric cardia carcinogenesis.

Asunto(s)

Genes de Retinoblastoma , Genes p16 , Lesiones Precancerosas/genética , Neoplasias Gástricas/genética , China/epidemiología , Expresión Génica , Humanos , Lesiones Precancerosas/epidemiología , Lesiones Precancerosas/etiología , Factores de Riesgo , Neoplasias Gástricas/epidemiología , Neoplasias Gástricas/etiología

RESUMEN

AIM:To determine the extent of apoptosis and its possible relationship with the changes of p53, Waflp21, bcl-2, and c-myc at different stages of esophageal carcinogenesis.METHODS:Two hundred and forty-one esophageal biopsy samples from symptom-free subjects and 38 surgically resected esophageal carcinoma tissues from a high-risk population for esophageal cancer in Henan, China were used in this study.Apoptotic cells and apoptotic bodies were identified by well-established morphological criteria. The extent of apoptosis and its possible relationship with the rate of cell proliferation (PCNA) and changes of p53, Waf1p21, bcl-2,and c-myc were analyzed in samples with esophageal precancerous and cancerous lesions.RESULTS:The apoptotic cells, identified morphologically, were located in the same proliferative compartment of hyperproliferative cell population in the esophageal epithelia as the cells immunostaining-positive for p53, bcl-2, c-myc and PCNA.The apoptotic indices (total number of apoptotic cells and apoptotic bodies per mm(2) of the tissue section) were low in the normal epithelia,and increased significantly as the lesions progressed from BCH to DYS and to SCC.The extent of apoptosis correlated well with the cell proliferation indices based on PCNA. The total number of positive cells for p53 stain was much higher than that of apoptotic cells. No difference in apoptotic indices was found between p53-positive and p53-negative samples. Waf1p21-positive cells resided in cell layers were higher in number than p53 and PCNA-positive cells. The number of immunostaining positive cells for Waflp21 increased slightly from normal to BCH,but decreased in DYS and SCC. Positive staining samples for bcl-2 and c-myc increased as the lesions progressed from BCH to DYS and to SCC. No apparent correlation between apoptosis and Waf1p21, bcl-2 or c-myc expression was observed.CONCLUSION:The extent of apoptosis was low in normal esophageal epithelium and increased as the lesions progressed. The apoptotic cells were located in the same hyperproliferative cell compartment as cells immunostaining-positive for p53, bcl-2,c-myc and PCNA,but no apparent correlation between apoptosis and these parameters was observed,possibly due to the complexities of molecular changes in esophageal carcinogenesis.

RESUMEN

AIM:To investigate the pathogenesis of gastric cardia and the distal part of stomach cancer and to further characterize the histopathogenesis model for gastric cardia cancer from the high-risk population for esophageal cancer.METHODS:Mass survey with endoscopic mucosa biopsy and histopathological examination were carried out on 226 subjects aged above 30 years. Three biopsies were collected one each from the middle part of the esophagus, the gastric cardia and the pyloric antrum. The biopsy tissue was fixed with 85% alcohol and paraffin-embedded.RESULTS:The incidence of intestinal metaplasia and dysplasia at gastric cardia epithelium was higher than that at the pyloric antrum from the subjects in the same area. And there were high incidences of both esophageal and gastric cardia cancer, but a low incidence of gastric cancer at the distal part of the stomach.CONCLUSION:There might be different etiology and pathogenesis of gastric cardia and pyloric cancer at the distal part of the stomach.