Dietary supplementation with L-arginine: modulation of tumour-infiltrating lymphocytes in patients with colorectal cancer.
BACKGROUND
Dietary supplementation with L-arginine enhances natural cytotoxicity in peripheral blood lymphocytes but its effect on infiltrating lymphoreticular cells within a tumour microenvironment is unknown. The effects of dietary supplementation with L-arginine on tumour-infiltrating lymphocytes (TILs) in patients with colorectal cancer were evaluated.


METHODS
Eighteen patients received either a standard hospital diet (controls) or a standard diet supplemented with 30 g per day of L-arginine for 3 days before surgery. Tumour biopsies were taken at surgery and lymphocyte subsets (CD antigens) and macrophages examined immunohistochemically.


RESULTS
Tumours from patients receiving L-arginine contained increased numbers of specific cell subsets within the tumour which expressed CD16 (P = 0.004) and CD56 (P = 0.001) surface markers, when compared with tumours from control patients. There were no differences in the total number of T and B cells, T helper and T suppressor cells.


CONCLUSIONS
Dietary supplementation with L-arginine significantly alter the spectrum of TILs in human colorectal cancers in vivo. These findings have important implications for new strategies in anticancer treatment.
Heys
S D
SD
Surgical Nutrition and Metabolism Unit, University of Aberdeen, UK.
Segar
A
A
Payne
S
S
Bruce
D M
DM
Kernohan
N
N
Eremin
O
O
D000368:Aged; D000369:Aged, 80 and over; D001120:Arginine / Q000008:administration & dosage*; D015179:Colorectal Neoplasms / Q000178:diet therapy* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D008875:Middle Aged; D017452:Receptors, IgG / Q000378:metabolism
D017452:Receptors, IgG; D001120:Arginine