M.W. Roomi, V. Ivanov, A. Niedzwiecki, M. Rath
Dr. Rath Research Institute, Oncology, 1260 Memorex Drive, Santa Clara, CA 95050

Presented at:
18th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics, November 7-10, 2006, Prague, Czechoslovakia

Published in: 
The European Journal of Cancer 2006, vol 4(12), abstract #520.

Abstract

Background:
Head and neck squamous cell carcinomas (HNSCC), the sixth most common malignancies in the United States, are known for their aggressive growth and propensity to invade and metastasize. We investigated the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract on human HNSCC cell line FaDu in vitro, evaluating viability, MMP secretion, invasion and morphology. In vivo studies were carried out in athymic nude mice bearing HNSCC FaDu xenografts.

Methods:
After one week of isolation, 5-6 weeks old athymic male nude mice were inoculated with 3x106 FADU cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed, and processed for histology. We also tested the effect of NM in vitro on FaDu cells, measuring cell proliferation by MTT assay, invasion through Matrigel, morphology by H&E staining, and secretion of MMPs by gelatinase zymography. Cells were also treated with PMA for MMP-9 induction.

Results:
NM strongly inhibited the growth of tumors by 50%. In vitro, NM exhibited dose response toxicity with maximum toxicity of 50% over the control at 1000 mg/ml. Zymography showed only a faint band representing MMP-2 and PMA-induced MMP-9. NM inhibited secretion of both MMP-2 and MMP-9 in a dose dependent fashion, with virtual total inhibition at 1000 mg/ml. Invasion through Matrigel was inhibited at 50, 100 and 500 mg/ml by 75%, 85% and 100% respectively. H&E staining did not indicate changes up to 100 µg/ml.

Conclusion:
In conclusion, NM has a great potential for therapeutic use in the treatment of HNSCC by suppressing tumor growth and significantly inhibiting MMP secretion and invasion of HNSCC cells in vitro.

Comment

Head and neck squamous cell carcinomas (HNSCC), the sixth most common malignancies in the United States, are known for their aggressive growth and propensity to invade and metastasize. We investigated the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract, shown to have potent antitumor effects on many cancer cell lines, on the growth of human HNSCC xenografts in athymic nude mice, as well as investigating this cell line in vitro, evaluating viability, MMP secretion, invasion and morphology. NM inhibited the growth of tumors by 50% and exhibited dose-response toxicity to cells in vitro, with 50% toxicity at 1000 µg/ml. In addition, NM inhibited the invasive parameters of MMP secretion and Matrigel invasion by cells in a dose-dependent manner with total block of MMPs at 1000 µg/ml and invasion at 500 µg/ml. These results are significant as they suggest that NM, a relatively safe therapeutic agent, has great potential in treatment of HNSCC in suppressing tumor growth and metastasis.