腺病毒介导白细胞介素24基因转染对胫骨癌痛大鼠的镇痛效应

目的 评价腺病毒介导白细胞介素24基因转染对胫骨癌痛大鼠的镇痛效应.方法 将已构建好的含IL-24基因的腺病毒(Ad-IL-24)和空白腺病毒载体(Ad-GFP)转入QBI-293A细胞,多次扩增后获得高效价病毒.雌性SD大鼠32只,体重180～200 g,随机分为4组(n=8):对照组(C组)、PBS阴性对照组(PBS组)、Ad-GFP组和Ad-IL-24组.C组不做任何处理,其余3组均于左侧胫骨骨髓腔内接种Walker 256乳腺癌细胞建立胫骨癌痛模型,建模后第9天分别在术侧后肢局部皮下注射PBS70μl、Ad-GFP70 μl和Ad-IL-24 70 μl,隔天给药,共3次.于接种前(基础状态)、接种后3、6、8、10、12、14d时测定机械痛阚;于接种后14 d时,取术侧胫骨组织,观察肿瘤细胞生长情况和骨小梁破坏情况;取股动脉血样测定血浆肿瘤坏死因子α(TNF-α)、IL-6、β-内啡肽、干扰素γ(IFN-γ)的浓度.结果 C组胫骨骨髓腔内未见异常,PBS组和Ad-GFP组肿瘤向外生长,骨小梁和骨皮质破坏;Ad-IL-24组骨小梁破坏程度较轻;骨皮质完整.与C组和基础值比较,PBS组、Ad-GFP组和Ad-IL-24组其余各时点机械痛阈降低(P<0.05);与PBS组和Ad-GFP组比较,Ad-IL-24组机械痛阈升高,血浆IFN-γ、β-内啡肽、TNF-α的浓度升高,IL-6浓度降低(P<0.05);PBS组和Ad-GFP组间上述指标差异无统计学意义(P>0.05).结论 腺病毒介导-IL-24基因转染对胫骨癌痛大鼠可产生一定程度的镇痛效应,其机制与其可抑制肿瘤细胞生长和调节细胞因子分泌有关.

Analgesic effects of adenovirus-mediated IL-24 gene transfection in rats with tibial cancer pain

Objective To evaluate the analgesic effects of adenovirus-mediated IL-24 (Ad-IL-24) gene transfection in rats with tibial cancer pain. Methods QBI-293A cells were transfected with Ad-IL-24 and Ad-GFP respectively according to Wang et al. High titer adenovirus was acquired after being amplified many times. Thirty-two female SD rats weighing 180-200 g were randomly divided into 4 groups (n = 8 each) :group Ⅰ normal control; group Ⅱ PBS; group Ⅲ Ad-GFP and group Ⅳ Ad-IL-24. Bone cancer was induced by injecting Walker 256 cancer cells into left tibia. On the 9th day after cancer cell inoculation, 70 μl of PBS, Ad-GFP and Ad-IL-24 were injected subcutaneously into the operated hindleg once every other day×3 times respectively. Pain threshold to noxious mechanical stimulation was measured before (baseline) and on days 3, 6, 8, 10, 12, 14 after cancer cell inoculation. The operated legs were then cut and stained with haematoxylin and eosin (HE) for examination of tumor infiltration and bone destruction. Plasma concentrations of TNF-α, IL-6, β-endorphin and IFN-γ were measured on the 14th day after cancer cell inoculation. Results Mechanical pain threshold was significantly decreased after cancer cell inoculation in group Ⅱ-Ⅳ as compared with the baselines and control group. Administration of Ad-IL-24 significantly decreased mechanical hyperalgesia induced by cancer cell inoculation in group Ⅳ as compared with PBS and Ad-GFP groups (group Ⅱ and Ⅲ). Plasma concentrations of IFN-γ, β-endorphin and TNF-α were significantly higher, while plasma IL-6 concentration was significantly lower in group Ad-IL-24 than in group PBS and Ad-GFP. In group PBS and Ad-GFP the tumor destroyed bone matrix and periosteum and grew out of the bone. Repeated Ad-IL-24 administration ameliorated the damage caused by cancer. Conclusion Ad-IL-24 gene transfection can decrease the degree of tibial cancer pain induced by Walker 256 cell inoculation through suppression of the growth of tumor and modification of cytokine secretion.