Related Experiment Videos
Decreased cyclic inositol phosphohydrolase activity in hamster renal tumors and human renal cell carcinomas
M C Sekar1, V Sambandam, D Roy
1Department of Pathology, University of Alabama at Birmingham 35294, USA.
Insights
Cyclic inositol phosphohydrolase (cIPH) activity is significantly reduced in both hamster and human renal tumors. This enzyme
Area of Science:
- Biochemistry
- Enzymology
- Oncology
Background:
- Cyclic inositol phosphohydrolase (cIPH) hydrolyzes cyclic inositol monophosphate, a molecule involved in cell density regulation.
- Highest cIPH activity is typically found in renal tissue across various species.
Purpose of the Study:
- To investigate whether cIPH enzyme activity is altered in renal tumors.
- To determine the impact of diethylstilbestrol (DES) on cIPH activity in kidney tissue.
Main Methods:
- Assessing cIPH activity in diethylstilbestrol-induced hamster renal tumors and normal kidney tissue.
- Measuring cIPH activity in normal human kidney (cortex, medulla) and renal cell carcinoma samples.
Main Results:
- Hamster renal tumors exhibited an 87% reduction in cIPH activity compared to controls.
- Short-term DES treatment in hamsters led to a 28% decrease in kidney cIPH activity.
- Human renal cell carcinoma showed significantly lower cIPH activity (1.9 +/- 2.3) than normal kidney cortex (10.6 +/- 4.6) and medulla (6.7 +/- 4.6).
Conclusions:
- cIPH activity is markedly decreased in renal tumors of both hamsters and humans.
- This reduction in cIPH may be associated with renal tumor development or progression.
Abstract:
Cyclic inositol phosphohydrolase (cIPH) (EC 3.1.4.36) hydrolyzes the cyclic phosphodiester bond of cyclic inositol monophosphate to yield inositol 1-phosphate. Renal tissue in various species has been shown to contain the highest activity of this enzyme. Cyclic inositol monophosphate, the substrate for this enzyme, has been implicated in the regulation of cell density. Thus, we determined whether activity of this enzyme is modulated in renal tumor. Samples of hamster renal tumors induced by diethylstilbestrol (DES) demonstrated 87% less cIPH activity than control hamster kidney. After 8 days of DES treatment of hamsters, a 28% decrease in the cIPH activity in kidney was observed. Interestingly, comparison of the cIPH activity in normal human kidney cortex, medulla, and renal cell carcinoma gave the following values (mean +/- SD), 10.6 +/- 4.6 (9), 6.7 +/- 4.6 (5), and 1.9 +/- 2.3 (8), respectively. Our study demonstrates that cIPH activity is reduced in hamster and human renal tumors.