放化疗对IRM-2小鼠不同肿瘤模型治疗作用的研究

目的观察IRM-2小鼠的肿瘤易感性,探讨放化疗对IRM-2小鼠不同肿瘤模型的抑制作用。方法利用120只IRM-2近交系小鼠,分别接种肺腺癌(LA795)、宫颈癌(U14)、黑色素瘤(B16)、肝癌(HepA)细胞,造模24 h后,将荷瘤鼠随机分为对照组、照射组、环磷酰胺组,每组各10只。照射组于第4天开始进行1 Gy全身照射,每日1次,连续5 d,共照射5次。环磷酰胺组(25 mg/kg)腹腔注射隔日1次,0.2 mL/只,共4次。对照组注射相同体积生理盐水。小鼠于第12天处死,解剖瘤块、胸腺和脾脏称重,骨髓有核细胞计数,计算抑瘤率、胸腺及脾重指数。结果①IRM-2小鼠皮下移植4种肿瘤的成瘤率均为100%。②环磷酰胺组、照射组LA795的抑瘤率分别为(31.8±27.3)%、(68.2±18.2)%,差异有高度统计学意义(P<0.01)。环磷酰胺组、照射组瘤重(0.07±0.04)、(0.15±0.06)g]均低于对照组(0.22±0.15)g],差异有统计学意义(P<0.05);环磷酰胺组瘤重低于照射组,差异有高度统计学意义(P<0.01)。③环磷酰胺组、照射组U14的抑瘤率分别为(37.3±3.5)%、(70.8±8.2)%,差异有统计学意义(P<0.05)。环磷酰胺组瘤重(0.50±0.14)g]低于对照组(1.71±0.60)g]及照射组(1.14±0.06)g],差异有统计学意义(P<0.05或P<0.01)。④环磷酰胺组、照射组对黑色素瘤B16的抑瘤率分别为(17.7±15.8)%、(63.6±15.9)%,差异有高度统计学意义(P<0.01)。环磷酰胺组脾重指数、瘤重与对照组比较差异有统计学意义(P<0.05或P<0.01);环磷酰胺组瘤重(0.72±0.31)g]低于照射组(1.63±0.51)g],差异有高度统计学意义(P<0.01)。⑤环磷酰胺组、照射组对肝癌HepA的抑瘤率分别为(31.5±21.7)%、(69.6±25.0)%,差异有高度统计学意义(P<0.01)。环磷酰胺组、照射组瘤重(0.28±0.23)、(0.63±0.20)g]均低于对照组(0.92±0.16)g],差异均有高度统计学意义(P<0.01);环磷酰胺组瘤重低于照射组,差异有高度统计学意义(P<0.01)。结论 IRM-2近交系小鼠对肺腺癌、宫颈癌、黑色素和肝癌均能有效接种,放疗对接种肿瘤有一定杀伤作用,环磷酰胺能有效抑制IRM-2小鼠肿瘤的生长,疗效更佳。

Research of therapeutic effects of radiotherapy and chemotherapy on different tumor models of IRM-2 mouse

Objective To observe the cancer susceptibility of IRM-2 mice and to explore the inhibition effects of ra- diotherapy and chemotherapy to different tumor models of IRM-2 mice. Methods 120 IRM-2 inbred mice were inocu- lated with lung adenocarcinoma （LA795）, cervical carcinoma （U14）, melanoma （B16）, and hepatoma （HepA） cell re- spectively. 24 hours after inoculation, the tumor-bearing mice were randomly divided into control group, irradiation group, cyclophosphamide group with 10 mice in each group. Started from the fourth day, mice in irradiation group were given 1 Gy body irradiation one time a day for five consecutive days. Mice in cyclophosphamide group were given in-traperitoneal injection （25 mg/kg） every other day, the dose was 0.2 mL/mice for a total of four times. The con- trol group was injected with the same volume of saline. Mice were sacrificed on day 12 and dissected. The tumor mass, thymus and spleen were weighted, bone marrow nucleated cell were counted to calculate the tumor inhibition rate and thymus and spleen weight index. Results ①The tumor formation rate of four kinds of tumor subcutaneously transplanted to IRM-2 mice was 100%. ②The tumor inhibi- tion rate of LA795 in cyclophosphamide group and irradiation group was （31.8±27.3） %, （68.2±18.2） % respectively, the difference was statistically significant （P 〈 0.01）. The tumor mass in cyclophosphamide group and irradiation group （0.07±0.04）, （0.15±0.06） g] were all lower than that in control group （0.22±0.15） g], the differences were statistically significant （P 〈 0.05）; the tumor mass in cyclophosphamide group was lower than that in irradiation group, the difference was statistically significant （P 〈 0.05）. ③The tumor inhibition rate of U14 in cyclophosphamide group and irradia- tion group was （37.3±3.51） %, （70.8±8.19） % respectively, the differences were statistically significant （P 〈 0.05）. The tumor mass in cyclophosphamide group （0.50±0.14） g] was all lower than that in control group （1.71±0.60） g] and irradiation group （1.14±0.06） g], the difference was statistically significant （P 〈 0.05 or P 〈 0.01）. ④The tumor inhibition rate of B16 cyclophosphamide group and irradiation group （17.7±15.8） %, （63.64±15.90） % respectively, the difference was statistically significant （P 〈 0.01）. The differences of spleen index, tumor mass between cyclophosphamide group and control group were statistically significant （P 〈 0.05 or P 〈 0.01）; the tumor mass in cyclophosphamide group （0.72±0.31） g] was lower than that in control group （1.63±0.51） g], the difference was statistically significant （P 〈 0.01）. The tumor inhibition rate of HepA cyclophosphamide group and irradiation group was （31.52±21.70） %, （69.57±25.00） %, the difference was statistically significant （P 〈 0.01）. The tumor mass in cyclophosphamide group and irradiation group （0.28±0.23）, （0.63±0.20） g] were all lower than those in control group （0.92±0.16） g], the differences were statistically significant （P 〈 0.01）; the tumor mass in cyclophosphamide group was lower than that in irradiation group, the differences were statistically significant （P 〈 0.01）. Conclusion IRM-2 inbred mice can be effectively inoc- ulated with lung adenocarcinoma, cervical cancer, melanoma, and hepatoma. Radiotherapy has certain killing effects to tumors of IRM-2 mice while CTX can effectively inhibit tumor growth in IRM-2 mice, thus cyclophosphamide showes better efficacy.