Expressions of C-erbB2 and C-myc in Esophageal and Gastric Cardia Multistage Carcinogenesis from the Subjects at High-risk Area in Linxian, Northern China

~ Abstract: Linxian and nearby counties in Henan Province, northern China have been well-recognized as the highest incidence area for both esophageal squamous cell carcinoma (SCC) and gastric cardia adenocarcinoma (GCA). The molecular mechanism for SCC and GCA is largely unknown. Recent studies indicate that aberrations of DNA copy numbers at 8q and 17p in which the genes of Gmyc and C-erbB2 reside, are very common events in SCC and GCA from the patients in Linxian. The present study was undertaken to characterize the changes of C-erbB2 and C-myc in protein level on the subjects with different esophageal and gastric cardia precancerous and cancerous lesions from Linxian. In the study, 144 samples were collected, including 30 SCC and 30 GCA from Linxian Esophageal Cancer Hospital and 84 biopsies from symptom-free subjects (16 cases with normal esophageal epithelia (ENOR), 34 with esophageal basal cell hyperplasia (BCH), 8 with esophageal dysplasia (EDYS), 7 with normal gastric cardia epithelia (GNOR), 6 with chronic superficial gastritis (CSG), 10 with chronic atrophic gastritis (CAG), and 3 with gastric cardia dysplasia (GDYS». The avidin-biotin-peroxidase complex (ABC) method was performed for the expre-'ision of C-erbB2 and C myc. No immunoreactivity was observed for C-erbB2 in normal esophagus, BCH and EDYS. However, 50% of SCC was positive for C-erbB2 immunostaining. In contrast, positive immunostaining for C-myc was observed in normal esophageal epithelia and different lesions. With lesions progres..sed from ENOREDYS-SCC, the positive immunostaining rates for C-myc increased apparently. In gastric cardia, positive immunoreactivity for both C-erbB2 and C-myc was observed in normal gastric cardia epithelia and different lesions. With the le-sions progre&'ied from GNOR-CSG-CAG-GDYS-GCA, an apparent increasing tendency was observed for both C-erbB2 and C-myc. In gastric cardia multistage carcinogenesis, the positive immunostaining rate for C-erbB2 and C-myc was much higher than in esophagus. The present results demonstrate that the immunostaining patterns for C-erbB2 and C-myc are different between esophageal and gastric cardia carcinogenesis from the population at same high-risk area in Linxian. Overexpression of both C-erbB2 and C-myc is a common event in gastric cardia multistage carcinogenesis, which may be a promising early biomarker for gastric cardia carcinogenesis. C-erbB2 may be a late event for esophageal carcinogenesis. [Life Science Journal. 2006; 3(3): 6 12J (ISSN: 1097 8135). ) J ]