Protein kinase C (PKC) includes a family of related proteins which constitutes a major signal transduction pathway. The aim of this study was to determine the localization of the PKC-α isoform throughout the human gastrointestinal tract. PKC-α expression was also measured and compared between normal and neoplastic colorectal tissue. PKC-α mRNA expression was detected in normal human gastrointestinal tract tissue using Northern blot analyses and in situ hybridization. PKC-α protein expression was detected in normal gastrointestinal tissue and colorectal neoplasia using Western blot and immunohistochemical analyses. PKC-α was expressed throughout the human gastrointestinal tract. Distinct organ and cellular localization was characterized. PKC-α mRNA and protein localization were most prevalent in the deep basal layer of the esophageal mucosa. In the stomach, PKC-α expression was detected predominately in the cells of the deep glands and surface epithelial cells but less in the mucous neck cells of the gastric pits. In the duodenum and ileum, PKC-α mRNA expression was greater in the deeper crypt cells than in the differentiated cells that line the villi. However, immunohistochemistry showed greater expression in the cells of the villi compared to crypt cells. In normal colonic tissue, PKC-α mRNA and protein predominated in the cells of the upper crypt and surface epithelial cells. PKC-α protein was also prominently expressed in the glands of colorectal adenocarcinoma. There was no quantitative difference in the level of PKC-α protein expression between normal and neoplastic colorectal tissue. The specific organ and cellular expression of PKC-α suggests separate and distinct functional roles for this PKC isoform throughout the gastrointestinal tissues.
|Number of pages
|Cell Growth and Differentiation
|Published - 1996
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology