Introduction: We have characterized a nutrient mixture 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 cancer cell lines.

Objective: We investigated the effect of NM on modulation of P-glycoprotein (Pgp) in the drug-resistant human uterine sarcoma cell line MES-SA/Dx5 and compared it with the effect on drug-sensitive cell line MES-SA. In addition we also studied the effect of NM on MMP expression and Rhodamine-123 accumulation and efflux.

Material and Methods: Human drug insensitive uterine sarcoma cell line MES-SA/Dx5 and drug sensitive cell line MES-SA (ATCC) were grown in RPMI 1640 medium supplemented with fetal bovine serum and antibiotics. At near confluence, the cells were tested with NM at 0, 50, 100, 250, 500 and 1000 mcg/ml, in triplicate at each dose. Cell proliferation was evaluated by MTT assay, MMPs by gelatinase zymography, and Pgp expression by Western blot and immunodetection using FITC-conjugated antibody and rhodamine-123 (Rh-123) accumulation and efflux assays.

Results: NM exhibited antiproliferative effect on MES-SA/Dx5, by 20% at 50 and 100 mcg/ml and by 40% at 25, 500 and 1000 mcg/ml, whereas in MES-SA cell line, NM showed dose-response toxicity of 40% at 50 and 30% at 1000 mcg/ml. In both cell lines, zymography demonstrated a band corresponding to MMP-2 in normal cells and MMP-9 with PMA treatment. Both MMPs showed dose-response inhibition by NM. NM treatment also showed diminished dose-dependent Pgp expression by MES-SA/Dx5 cell line by Western blot and by immunodetection, whereas MES-SA did not exhibit Pgp by Western blot or by immunostaining. NM enhanced the accumulation and efflux of Pgp substrate Rh-123 in MES-SA/Dx5 uterine sarcoma cell line but not in the drug-sensitive cell line MES-SA.

Conclusions: In summary, this study demonstrated that Pgp is modulated by NM, which may be an attractive potential agent for therapeutic use in cancer treatment

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2260.