含CpG的寡脱氧核苷酸与5-氟尿嘧啶联用治疗小鼠肝癌

The therapeutic potential of CpG-containing oligodeoxynucleotides and its combination with 5-fluorouracil in murine hepatoma

目的 探讨含CpG的寡脱氧核苷酸(ODN)单独及与5- 氟尿嘧啶(5 -FU)联用对小鼠移植性肝癌的治疗作用。方法 Balb/c小鼠皮下接种肝癌H22 细胞建立荷瘤鼠模型,肿瘤周围皮下分别注射生理盐水(对照组)、无CpG ODN、5 -FU、CpG ODN和CpG ODN+5 FU后,定期测量肿瘤大小。用酶联免疫吸附实验检测鼠血清白细胞介素(IL)- 12和干扰素(IFN) -γ含量;用乳酸脱氢酶释放法检测鼠脾脏自然杀伤(NK)细胞活性。结果 与对照组肿瘤体积[(6710±910) mm3 ]比较, CpG ODN、CpGODN+5- FU及单用5 -FU治疗后,肿瘤体积分别为(3579±481) mm3、(1998±474) mm3 及(2124±434) mm3(P值均<0.01)。对照组鼠血清IL -12 和IFN -γ的含量分别为(238±45) pg/ml和(57±8)pg/ml,与CpG ODN组[IL 12:(464±24) pg/ml;IFN -γ:(134±26) pg/ml]及CpG ODN+5 -FU组[IL -12:(336±29) pg/ml;IFN -γ:(111±5) pg/ml]比较,差异有统计学意义(P值均<0.05)。CpG ODN+5- FU组小鼠血清IL- 12及IFN -γ水平显著高于5- FU组[IL 12:(167±53) pg/ml;IFN -γ:(53±17) pg/ml;P<0.05]。与对照组NK细胞的杀伤活性[(19.2±1.0)%]相比,CpG ODN组[(44.0±1.4)%]及CpG ODN+5 FU组[(30.7±1.3)%]显著增强(P值均<0.05),且CpG ODN+5 FU组显著高于5- FU治疗组[(12.

Objective To investigate the therapeutic potential of CpG-containing oligodeoxy- nucleotides (CpG ODN) and its combination with 5-fluorouracil (5-FU) in murine hepatoma. Methods Hepatoma model was established by subcutaneously inoculating H_ 22 cells into the right flank in Balb/c mice. Tumor size was measured regularly after peritumoral injection of saline, ODN, 5-FU, CpG ODN and CpG ODN in combination with 5-FU. Serum levels of interleukin (IL)-12 and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay. The lytic capacity of splenic natural killer (NK) cells was tested by lactate dehydrogenase release assay. Results Compared with the controls [(6710±910) mm 3], tumor volumes in CpG ODN group [(3579±481) mm 3],CpG ODN and 5-FU combination group [(1998±474) mm 3] and 5-FU group [(2124±434) mm 3] were significantly shrunk ( P < 0.01 respectively ). Serum levels of IL-12 and IFN-γ in CpG ODN group [IL-12:(464± 24 ) pg/ml; IFN-γ: (134±26) pg/ml] and CpG ODN+5-FU combination group [IL-12:( 336 ± 29 ) pg/ml; IFN-γ: (111±5) pg/ml] were significantly higher than those of controls [IL-2:(238±45) pg/ml;IFN-γ: (57±8) pg/ml], P <0.05. Besides, serum levels of IL-12 and IFN-γ in combination group were significantly increased as compared with 5-FU alone [IL-12:( 1667 ± 53 ) pg/ml; IFN-γ: (53±17) pg/ml], P <0.05. The killing activity of NK cell both in CpG ODN group [(44.0±1.4) %] and CpG ODN+5-FU com- bination group [(30.7±1.3) %] was significantly increased than that of controls [(19.2±1.0)%], P < 0.05 . Meanwhile, the lytic activity of NK cells in combination group was markedly enhanced when compared with 5-FU alone [( 12.0 ± 1.4 ) %], P <0.05.Non-CpG ODN treatment had no effects on tumor growth, IL-12, IFN-γ and NK cell activity in mice. Conclusions The present study suggested that CpG ODN could activate the host anti-tumor immune response to inhibit the growth of implanted hepatoma, and improve the immunosuppression caused by chemotherapy with 5-FU.