Antisense expression of PKCalpha improved sensitivity of SGC7901/VCR cells to doxorubicin.

Aim: To explore whether antisense blocking of protein kinase C alpha (PKCalpha) would reverse multi-drug resistance (MDR) in the vincristine (VCR)-resistant human gastric cancer cell line SGC7901/VCR.

Methods: SGC7901/VCR cells expressing antisense PKCalpha, SGC7901/VCR/aPKC, were established by transfection with a recombinant plasmid reversely inserted with PKCalpha cDNA. Empty vector (PCI-neo)-transfected cell clones, SGC7901/VCR/neo, served as the control.

Expression of ATP7B in human gastric cardiac carcinomas in comparison with distal gastric carcinomas.

Aim: To analyze expression of ATP7B in gastric cardiac adenocarcinomas, its clinicopathologic significance, in comparison with distal gastric adenocarcinomas.

Methods: Immunohistochemical avidin-biotin peroxidase complex method was applied to detect the expression of ATP7B in 49 cases of cardiac carcinomas, the corresponding adjacent non-neoplastic epithelium and 55 cases of distal gastric carcinomas.

Results: The proportion of ATP7B positive samples in gastric cardiac carcinomas (51.

Methylation in esophageal carcinogenesis.

Genetic abnormalities of proto-oncogenes and tumor suppressor genes have been demonstrated to be changes that are frequently involved in esophageal cancer pathogenesis. However, hypermethylation of CpG islands, an epigenetic event, is coming more and more into focus in carcinogenesis of the esophagus. Recent studies have proved that promoter hypermethylation of tumor suppressor genes is frequently observed in esophageal carcinomas and seems to play an important role in the pathogenesis of this tumor type.