Abnormal binding pattern and composition of the NF-kappaB complex components are involved in increased TNF-alpha production by tumor bearer B cells.
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- Published online on: April 1, 1999 https://doi.org/10.3892/ijmm.3.4.411
- Pages: 411-417
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Abstract
B lymphocytes from mammary tumor bearers are cytotoxic against tumor targets and produce TNF-alpha. A greater stability of RNA and a decreased rate of RNA degradation was observed in B cells of tumor bearers compared to those of normal mice. The TNF-alpha promoter contains regions that bind NF-kappaB, which regulate the rate of transcription. Supershift assays for the NF-kappaB region showed that there are p50-p65 heterodimers and p50 homodimers in the nuclear extracts of the two types of B cells, while those from tumor bearers lack the c-Rel component that is present in normal B cells. These results indicate that abnormalities in binding and composition of the NF-kappaB complexes may be involved in the increased TNF-alpha production by B cells of tumor bearers.