Premium
Protein kinase C activity in human colonic adenoma and colorectal carcinoma
Author(s) -
Kusunoki Masato,
Sakanoue Youichirou,
Hatada Takuya,
Yanagi Hidenori,
Yamamura Takehira,
Utsunomiya Joji
Publication year - 1992
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/1097-0142(19920101)69:1<24::aid-cncr2820690107>3.0.co;2-1
Subject(s) - protein kinase c , cytosol , adenoma , medicine , carcinoma , endocrinology , pathology , carcinogenesis , gastroenterology , enzyme , biology , cancer , biochemistry
To additionally understand the molecular mechanisms and biologic indicators of colonic tumorigenesis through the adenoma‐carcinoma sequence, protein kinase C (PKC) activity was examined in the cytosol and particulate fraction of specimen homogenates from 18 human colonic carcinomas and seven coexisting colonic adenomas and was compared with the ddjaceni normal mucosal tissues. This study showed that PKC activity could be detected precisely using mini DEAE‐Sephacel column purification and histone III‐S as a substrate. The PKC activity in both colonic adenoma and carcinoma progressively was reduced in the particulate fraction compared with that of the adjacent normal mucosa from each patient (74.9 ± 11.3 and 42.4 ± 9.37 versus 112 ± 16.8 pmol/min/mg, P < 0.001), although PKC activity in the cytosolic fraction was not significantly different (62.6 ± 17.7 and 63.1 ± 8.08 versus 56.4 ± 7.32 pmol/min/mg) with respect to protein concentration. Both colonic adenomas and carcinomas showed a significant progressive decrease in total particulate PKC activity compared with the adjacent normal mucosa of each patient (13.5 ± 2.18 and 7.64 ± 1.35 versus 19.8 ± 2.74 pmol/min/g tissue, P < 0.001) and no difference in total cytosolic PKC activity (15.2 ± 3.80 and 16.5 ± 2.02 versus 14.6 ± 1.81 pmol/min/g tissue). Among PKC activities in carcinomas, there was no difference related to histologic type, Dukes' staging, or carcinoembryonic antigen values. Among PKC activities in colonic adenomas, a significant decrease in particulate PKC correlated with size. The specific PKC activity in the particulate fraction decreased with advancing adenoma size ( P < 0.05). This study showed that colonic carcinogenesis might be associated with alterations in cellular levels of PKC activity and that the decrease in particulate PKC activity in the adenoma had a possible correlation with adenoma size.