Renal cell carcinoma (RCC) is erratic and unpredictable even when diagnosed. The incidence rates for RCC are higher among African Americans and the male to female ratio for RCC is 2:1. At diagnosis, five-year survival is limited to 60% in RCC patients. Melanoma, a very serious form of skin cancer, is a relatively rare cancer. However, its incidence rate in the U.S. has been increasing steadily, and it was the sixth most common cancer in the U.S. in 2003. Though often curable in its early stages, melanoma can metastasize to other areas of the body. We have characterized in our laboratory a nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract as a novel antineoplastic agent with a broad spectrum of antitumor activity against a number of human cancer cell lines.
We investigated whether the underlying antitumor effect of NM observed in human RCC and melanoma was due to apoptosis.
Materials and Methods:
Human RCC 786-0 and human melanoma cells A2058 (ATCC) were cultured in RPMI and DMEM medium respectively and treated with NM in different concentrations: 0, 100, 500 and 1000 µg/ml. Growth inhibition was detected by MTT assay, morphology by H&E staining, and apoptosis by Live Green Caspase Detection Kit.
NM showed no significant effect on RCC growth, exhibiting slight toxicity at 100 µg and significant at 500 and 1000 µg/ml. RCC 786-0 cells treated at 500 and 1000 µg/ml NM and melanoma A2058 cells treated with 100, 500 and 1000 µg/ml NM and stained by H&E demonstrated obvious apoptotic cells with shrinkage and darkly stained and condensed nuclei and strong acidophilic cytoplasm. Using live green caspases kit a significant number of early and late apoptotic RCC cells were demonstrated at 500 and 1000 µg/ml NM and a considerable number of apoptotic melanoma cells at 100 µg/ml, with significant increase at 500 and 1000 µg/ml NM.
Our results suggest that the anticancer activity of NM on RCC and melanoma cells is due in part to its apoptotic effect on these cell lines.
Renal cell carcinoma is an aggressive cancer, with five-year survival limited to 60% at diagnosis. Melanoma, a rare but serious form of skin cancer, can metastasize to other areas of the body. In previous studies we have shown that the anticancer activity of the nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract on these cancer cell lines. In this study we studied whether the underlying antitumor effect seen was due to induction of apoptosis (programmed cell death). NM induced apoptotic cells in RCC and melanoma cells in a dose-dependent manner with early and late apoptotic cells of both cell lines observed at 500 and 1000 µg/ml NM, indicating that anticancer acitivty of NM on RCC and melanoma cells is partly due to induction of apoptosis.