TY - JOUR
T1 - Prostaglandin E 2 suppresses NK activity in vivo and promotes postoperative tumor metastasis in rats
AU - Yakar, Ilan
AU - Melamed, Rivka
AU - Shakhar, Guy
AU - Shakhar, Keren
AU - Rosenne, Ella
AU - Abudarham, Naphtali
AU - Page, Gayle G.
AU - Ben-Eliyahu, Shamgar
PY - 2003
Y1 - 2003
N2 - Background: Prostaglandins (PGs) were shown in vitro to suppress several functions of cellular immunity. It is unclear, however, whether physiological levels of PGs can suppress cellular immunity in vivo and whether such suppression would compromise postoperative host resistance to metastasis. Methods: Fischer 344 rats were administered PGE 2 in doses (18 to 300 μg/kg subcutaneously) that increased the serum levels approximately 2- to 4-fold. We then assessed the number and activity of circulating natural killer (NK) cells, as well as rats' resistance to experimental metastasis of a syngeneic NK-sensitive tumor (MADB106). To study whether endogenously released PGs after surgery compromise these indices, we tested whether laparotomy adversely affects them and whether a cyclooxygenase-synthesis inhibitor, indomethacin (4 mg/kg), attenuates these effects. Results: PGE 2 dose-dependently suppressed NK activity per NK cell and dose-dependently increased 4- and 24-hour MADB106 lung tumor retention (LTR); 240 μg/kg of PGE 2 quadrupled the number of lung metastases counted 3 weeks later. Selective depletion of NK cells abrogated the promotion of LTR by PGE 2. Surgery significantly suppressed NK activity and increased MADB106 LTR, and indomethacin halved these effects without affecting nonoperated rats. Conclusions: PGE 2 is a potent in vivo suppressor of NK activity, and its postoperative release may promote tumor recurrence.
AB - Background: Prostaglandins (PGs) were shown in vitro to suppress several functions of cellular immunity. It is unclear, however, whether physiological levels of PGs can suppress cellular immunity in vivo and whether such suppression would compromise postoperative host resistance to metastasis. Methods: Fischer 344 rats were administered PGE 2 in doses (18 to 300 μg/kg subcutaneously) that increased the serum levels approximately 2- to 4-fold. We then assessed the number and activity of circulating natural killer (NK) cells, as well as rats' resistance to experimental metastasis of a syngeneic NK-sensitive tumor (MADB106). To study whether endogenously released PGs after surgery compromise these indices, we tested whether laparotomy adversely affects them and whether a cyclooxygenase-synthesis inhibitor, indomethacin (4 mg/kg), attenuates these effects. Results: PGE 2 dose-dependently suppressed NK activity per NK cell and dose-dependently increased 4- and 24-hour MADB106 lung tumor retention (LTR); 240 μg/kg of PGE 2 quadrupled the number of lung metastases counted 3 weeks later. Selective depletion of NK cells abrogated the promotion of LTR by PGE 2. Surgery significantly suppressed NK activity and increased MADB106 LTR, and indomethacin halved these effects without affecting nonoperated rats. Conclusions: PGE 2 is a potent in vivo suppressor of NK activity, and its postoperative release may promote tumor recurrence.
KW - Animals
KW - Cytotoxicity
KW - NK cells
KW - Tumor immunology
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U2 - 10.1245/ASO.2003.08.017
DO - 10.1245/ASO.2003.08.017
M3 - Article
C2 - 12734098
AN - SCOPUS:0041660554
SN - 1068-9265
VL - 10
SP - 469
EP - 479
JO - Annals of surgical oncology
JF - Annals of surgical oncology
IS - 4
ER -