Paradoxical roles for antioxidants in tumor prevention and eradication.

Antioxidants have been shown to provide protection against carcinogens, toxic xenobiotics and oxidative stress. This has led to the hypothesis that the addition of antioxidants to cancer chemotherapeutic regimens could increase their efficacy while reducing the side effects often encountered during treatment. The work described in this study set out to test this hypothesis using two different chemotherapeutics, Paclitaxel and FUdR, and three different antioxidants, epigallocatechin gallate, phenethyl isothiocyanate and tert-butylhydroquinone.

The potential role of neutrophils in promoting the metastatic phenotype of tumors releasing interleukin-8.

In the last decade, several groups have shown a direct correlation between the inappropriate or ectopic release of interleukin (IL)-8 by tumor cells in vitro and their growth and metastatic potential using in vivo models of tumor growth. IL-8 is a potent neutrophil chemoattractant. Neutrophils, as "early responders" to wounds and infections, release enzymes to remodel the extracellular matrix of the tissues through which they migrate to reach the site of the wound or infection.

Atypical methylation of the interleukin-8 gene correlates strongly with the metastatic potential of breast carcinoma cells.

Previously, we have shown that a strong correlation exists between the metastatic potential of breast carcinoma cell lines and their ectopic expression of IL-8. The undifferentiated, highly metastatic cell lines with high metastatic potential produce much more IL-8 than their differentiated lower metastatic counterparts. After eliminating the possibility that transcription factor activity was responsible for differences in IL-8 release, we examined the IL-8 gene for possible epigenetic modifications.