Effect of selenium in combination with Adriamycin or Taxol on several different cancer cells.

The anti-neoplastic properties of an Selenium compound were studied in vitro on several tumor cell lines: Breast (MCF-7, MCF-10, SKBR-3, BCAP37), Lung (RH2), Prostate (LNCap and PC-3), Colon (T84, Caco-2), Small Intestine (HCF8), and Liver (HepG2). We also examined additive or synergistic effect of Selenium in combination with standard anti-cancer drugs, Adriamycin (Doxorubicin) and Taxol. The effect of Selenium was assessed by apoptosis; DNA synthesis; growth rate by MTT assay; uptake of amino acid MeAIB by System A; and morphological changes. Our results demonstrate that MCF-7 and SKBR-3 showed increase in apoptosis as measured by DNA fragmentation and increase in "rounded" cells and membrane "blebbing", decrease in MeAIB uptake, and decrease in DNA synthesis. These changes were Selenium dose dependent with optimal inhibition at Selenium concentration between 4 and 40 ng/ml after 72 hrs of treatment. Similar observations were made with RH2, HCF8, Caco-2, and HepG2 cells. In contrast, LNCap, PC-3, and T-84 were not significantly affected by Selenium. However, addition of Adriamycin or Taxol in combination with Selenium caused small but significant inhibition of prostate cancer cells LNCap and PC-3. Addition of chemotherapeutic agents either Taxol or Doxorubicin with Selenium caused further inhibition of MCF-7, SKBR-3, RH2, HCF8, and HepG2 cells. In conclusion, Selenium has a significant anti-neoplastic effect on breast, lung, liver, and small intestinal tumor cells. Supplementation of Selenium enhanced chemotherapeutic effect of Taxol and Doxorubicin in these cells beyond that seen with the chemotherapeutic drugs used alone. These in vitro studies on several cancer cell lines suggest a potential benefit of Selenium-enhancement of anticancer effects other systems, and therefore offer further relevance to clinical trials efforts.