ABSTRACT
AIMS: To assess MRP1 protein and MRP1 mRNA levels in gastric carcinomas and in non-neoplastic mucosa remote from the tumours. MRP1 gene expression may play a role in the complex pattern of chemoresistance present in gastric carcinomas. METHODS AND RESULTS: A total of 57 carcinomas and respective gastric tissues were included for immunohistochemical assessment with the anti-MRP1 monoclonal antibodies MRPr1 and QCRL-1. Of these, 35 tumour and gastric mucosa tissues were also assessed by real-time quantitative reverse transcriptase-polymerase chain reaction. Medium or high MRP1 protein expression was detected in 89% and 77% of carcinomas and in 96% and 93% of non-neoplastic gastric mucosa by MRPr1and QCRL-1, respectively. No difference in MRP1 mRNA levels was detected between carcinomas and non-neoplastic gastric mucosa tissues in 77% of the patients. A significant correlation was found between MRP1 mRNA level and protein expression detected in carcinomas related to non-neoplastic gastric mucosa, although they were non-concordant in 29% of the patients. CONCLUSIONS: MRP1 gene is usually expressed in most gastric carcinomas and does not differ substantially from that observed in non-neoplastic gastric mucosa remote from the tumour. However, a decrease in MRP1 gene expression is found in some carcinomas. For accurate assessment of changes in MRP1 expression between tumour and normal tissues both protein and mRNA detection are necessary.
Subject(s)
Multidrug Resistance-Associated Proteins/genetics , Stomach Neoplasms/pathology , Gastric Mucosa/metabolism , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Multidrug Resistance-Associated Proteins/analysis , Neoplasm Staging , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction/methods , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolismABSTRACT
To study the effect intracolonic perfusion of nutrients has on exocrine pancreatic secretion, six dogs were prepared with gastric, duodenal, and cecal cannulas using a modified Thomas technique. In our study protocol, we collected pancreatic juice by selective ductal cannulation after having applied several types of intracolonic stimulation: perfusion of sodium chloride, tryptophan, rice starch + glucose, or sodium oleate. All these solutions were applied together with a background dose of intravenous secretin. Our results showed a significant increase in the volume of pancreatic juice and bicarbonate output after intracolonic perfusion of sodium oleate. Other perfusions did not change these parameters. Protein output did not change in any of the cases. It seems that the ascending colon plays a regulating role in pancreatic secretion; in some conditions the colon could increase exocrine pancreatic function.
