Tuberin haploinsufficiency is associated with the loss of OGG1 in rat kidney tumors
Autor: | Jeffrey L. Barnes, Simona Simone, Hanna E. Abboud, Samy L. Habib |
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Rok vydání: | 2007 |
Předmět: |
Male
congenital hereditary and neonatal diseases and abnormalities Cancer Research DNA repair Biology Haploidy Kidney lcsh:RC254-282 Rats Mutant Strains DNA Glycosylases Loss of heterozygosity 03 medical and health sciences Tuberous sclerosis 0302 clinical medicine Tuberous Sclerosis Complex 2 Protein medicine Animals neoplasms 030304 developmental biology 0303 health sciences Tumor Suppressor Proteins Research Wild type Deoxyguanosine Organ Size medicine.disease lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens Molecular biology Kidney Neoplasms nervous system diseases Rats Protein Transport medicine.anatomical_structure Oncology 8-Hydroxy-2'-Deoxyguanosine 030220 oncology & carcinogenesis Clear cell carcinoma Cancer research Molecular Medicine TSC2 Haploinsufficiency |
Zdroj: | Molecular Cancer Molecular Cancer, Vol 7, Iss 1, p 10 (2008) |
ISSN: | 1476-4598 |
Popis: | Background Tuberous sclerosis complex (TSC) is caused by defects in one of two tumor suppressor genes, TSC-1 or TSC-2. TSC-2 gene encodes tuberin, a protein involved in the pathogenesis of kidney tumors. Loss of heterozygosity (LOH) at the TSC2 locus has been detected in TSC-associated renal cell carcinoma (RCC) and in RCC in the Eker rat. Tuberin downregulates the DNA repair enzyme 8-oxoguanine DNA-glycosylase (OGG1) with important functional consequences, compromising the ability of cells to repair damaged DNA resulting in the accumulation of the mutagenic oxidized DNA, 8-oxo-dG. Loss of function mutations of OGG1 also occurs in human kidney clear cell carcinoma and may contribute to tumorgenesis. We investigated the distribution of protein expression and the activity of OGG1 and 8-oxo-dG and correlated it with the expression of tuberin in kidneys of wild type and Eker rats and tumor from Eker rat. Results Tuberin expression, OGG1 protein expression and activity were higher in kidney cortex than in medulla or papilla in both wild type and Eker rats. On the other hand, 8-oxo-dG levels were highest in the medulla, which expressed the lowest levels of OGG1. The basal levels of 8-oxo-dG were also higher in both cortex and medulla of Eker rats compared to wild type rats. In kidney tumors from Eker rats, the loss of the second TSC2 allele is associated with loss of OGG1 expression. Immunostaining of kidney tissue shows localization of tuberin and OGG1 mainly in the cortex. Conclusion These results demonstrate that OGG1 localizes with tuberin preferentially in kidney cortex. Loss of tuberin is accompanied by the loss of OGG1 contributing to tumorgenesis. In addition, the predominant expression of OGG1 in the cortex and its decreased expression and activity in the Eker rat may account for the predominant cortical localization of renal cell carcinoma. |
Databáze: | OpenAIRE |
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