M.W. Roomi, N.W. Roomi, M. Rath and A. Niedzwiecki
Dr. Rath Research Institute, Cancer Division, Santa Clara, CA, USA

Presented at: 
101st Annual Meeting of the American Association for Cancer Research, Washington, D.C., April 17-21, 2010.

Published in: 
Proceedings of the 101st Annual Meeting of the AACR, Vol 51, Abstract #2261, page 548.

Abstract

Introduction: 
Phytochemicals and dietary antioxidants are known to decrease the risk of inflammation and prevent cancer development. We have developed strategies to inhibit cancer progression and its spread by natural products. A nutrient mixture (NM) containing ascorbic acid, lysine, proline and green tea extract has exhibited anticancer activity in vitro and in vivo in a number of cancer cell lines.

Objective: 
We investigated the effect of NM on human lymphoma cell line U-937 in vitro by measuring: cell proliferation, MMP expression, invasion, apoptosis, and Cox-2 and Cox-1 protein expression.

Materials and Methods: 
Human lymphoma cell line U-937 (ATCC) was cultured in RPMI medium supplemented with fetal bovine serum and antibiotics. U-937 cells were seeded on 24-well tissue culture plates with 40nM phorbol 12-myristate 13-acetate (PMA). After 24 hrs, the cells were treated with NM at 0, 50, 100, 250, 500 and 1000 µg/ml, in triplicate at each dose. Cell proliferation was evaluated by MTT assay, MMP expression by gelatinase zymography, invasion through Matrigel, apoptosis by using live green caspase detection kit (Molecular Probe), and COX-2 and COX-1 expression by Western blot.

Results: 
NM was not toxic to U-937 cells at a concentration of 250 µg/ml and exhibited an antiproliferative effect at 500 µg/ml concentration. Zymography demonstrated only one band corresponding to MMP-9, which was inhibited by NM in a dose-dependent manner. Matrigel invasion was significantly reduced (by 95%) at 250 µg/ml NM and completely blocked at 500 µg/ml NM. NM induced slight apoptosis at 100 µg/ml and moderate at 500 and 1000 µg/ml concentration. NM inhibited Cox-2 expression in a dose-dependent fashion and had no effect on Cox-1 expression.

Conclusions: 
Our results suggest that NM is an excellent candidate for therapeutic use in the treatment of hematological malignancies.

Comment

Phytochemicals and dietary antioxidants are known to decrease the risk of inflammation and prevent cancer development. We investigated the effect of a micronutrient mixture (NM) containing lysine, proline, ascorbic acid, green tea extract and other micronutrients on human lymphoma cell line U-937 in vitro, measuring: cell proliferation, MMP expression, invasion, apoptosis, and Cox-2 and Cox-1 protein expression. NM demonstrated antiproliferative and induced moderate apoptosis at 500 µg/ml. Zymography demonstrated only MMP-9 expression, which was inhibited by NM in a dose-dependent manner. Matrigel invasion was significantly reduced (by 95%) at 250 µg/ml NM and completely blocked at 500 µg/ml. NM inhibited the inflammatory parameter Cox-2 expression in a dose-dependent fashion and had no effect on Cox-1 expression. Our results are significant as they suggest that the non-toxic agent NM is an excellent candidate for therapeutic use in the treatment of hematological malignancies.