喬莎++趙彬
[摘要] 目的 研究探討OK-432腫瘤疫苗對小鼠淋巴高轉(zhuǎn)移肝癌細(xì)胞Hca-F的抑制作用。 方法 對DBA/2小鼠背部接種高轉(zhuǎn)移肝癌細(xì)胞Hca-F,建立腫瘤轉(zhuǎn)移模型,設(shè)對照組和OK-432腫瘤疫苗組,3周后測量腫瘤大小,并繪制腫瘤生長曲線,檢測各組抑瘤率、淋巴結(jié)轉(zhuǎn)移抑制率,淋巴結(jié)石蠟切片HE染色觀察兩組淋巴細(xì)胞數(shù)。 結(jié)果 OK-432腫瘤疫苗具有明顯的抑瘤作用,抑瘤率達(dá)68.4%;淋巴結(jié)轉(zhuǎn)移抑制率為31.6%;通過比較對照組和給藥組淋巴結(jié)的HE染色,發(fā)現(xiàn)給藥組淋巴結(jié)內(nèi)淋巴細(xì)胞明顯多于對照組。 結(jié)論 OK-432腫瘤疫苗能夠有效抑制腫瘤生長,促進(jìn)機(jī)體免疫應(yīng)答,抑制腫瘤的淋巴結(jié)轉(zhuǎn)移。
[關(guān)鍵詞] OK-432腫瘤疫苗;淋巴結(jié)轉(zhuǎn)移;抑瘤率
[中圖分類號] R739.86 [文獻(xiàn)標(biāo)識碼] A [文章編號] 1673-9701(2015)01-0001-03
Research on inhibitory effect of OK-432 tumor vaccine on mice' liver cancer cells Hca-F
QIAO Sha ZHAO Bin
Department of Stomatology, Shanxi Medical University, Taiyuan 030001,China
[Abstract] Objective To investigate the inhibitory effect of OK-432 tumor vaccine on mice' highly lymph-metastatic liver cancer cells Hca-F. Methods Highly metastatic liver cancer cells Hca-F were planted in the back of DBA/2 mice and the tumor metastasis model was built. The control group and the OK-432 tumor vaccine group were set up, with 20 mice in each group. Three weeks later, the tumor size was measured, the tumor growth curve was drawn, the tumor inhibition rates and lymph node metastasis inhibition rates were detected, and the numbers of lymphocyte of the two groups were observed based on lymph gland paraffin section HE staining. Results OK-432 tumor vaccine had obvious tumor inhibition effects, with the tumor inhibition rate of 68.4%; The lymph node metastasis inhibition rate was 31.6%; Comparison of HE staining of the control group and the medication lymph node group showed that the number of lymphocyte in lymph node of the medication group was significantly larger than that of the control group. Conclusion OK-432 tumor vaccine can effectively inhibit tumor growth, promote body immune response and inhibit lymph node metastasis of tumor.
[Key words] OK-432 tumor vaccine; Lymph node metastasis; Tumor inhibition rate
近年來,腫瘤的發(fā)病率逐年增高且越來越年輕化,對患者的生命和健康造成嚴(yán)重的影響。目前全世界都在對腫瘤的預(yù)防和治療進(jìn)行研究。隨著腫瘤藥理學(xué)、分子生物學(xué)及免疫學(xué)等相關(guān)學(xué)科的快速發(fā)展和交叉滲透,腫瘤疫苗作為腫瘤治療、放療、化療后的一種輔助治療手段越來越受到人們的關(guān)注,本研究所用腫瘤疫苗為OK-432腫瘤疫苗[1]。OK-432腫瘤疫苗是通過菌體與癌細(xì)胞的直接接觸,使腫瘤細(xì)胞變性并暴露瘤細(xì)胞“隱藏”著的某些抗原決定簇,從而達(dá)到增強(qiáng)腫瘤抗原性的目的。研究表明,OK-432腫瘤疫苗可以顯著抑制荷瘤小鼠腫瘤的生長及轉(zhuǎn)移[2],并延長其生存期。本研究將背部接種了高轉(zhuǎn)移肝癌細(xì)胞Hca-F的DBA/2小鼠隨機(jī)分為兩組,分別給予腹腔注射OK-432腫瘤疫苗和生理鹽水,觀察OK-432腫瘤疫苗對腫瘤的抑制作用。
1 材料與方法
1.1 實(shí)驗(yàn)動物
雌性DBA/2小鼠40只,5~6周,體重16~20 g,購自北京維通利華實(shí)驗(yàn)技術(shù)有限公司。在SPF條件下喂養(yǎng),實(shí)驗(yàn)前至少適應(yīng)1周。
1.2 腫瘤細(xì)胞及培養(yǎng)方法
高轉(zhuǎn)移肝癌細(xì)胞Hca-F購自于上海愛丁堡生物科技有限公司。KLN-205腫瘤細(xì)胞在37℃,5%CO2恒溫箱傳代培養(yǎng),每次使用的培養(yǎng)液按照45 mL的RPMI-1640培養(yǎng)液加入5 mL胎牛血清,0.5 mL的雙抗的比例配制。選取培養(yǎng)4代以上活力旺盛的腫瘤細(xì)胞作為靶細(xì)胞。
1.3 藥物與試劑
OK-432為溶血鏈球菌減毒株凍干制劑,由中外制藥株式會社(日本) 提供。青鏈霉素購自Solarbio公司;胰蛋白酶(含EDTA),無菌PBS,D-Hanks緩沖液;無支原體胎牛血清為浙江天杭生物科技有限公司出品。
1.4 荷瘤小鼠的制備、分組及給藥方法
疫苗的制備按Li X等[1]的方法制備而成。將Hca-F腫瘤細(xì)胞在37℃,5%CO2恒溫箱傳代培養(yǎng),每次使用的培養(yǎng)液按照45 mL的RPMI-1640培養(yǎng)液加入5 mL胎牛血清,0.5mL的雙抗的比例配制。選取培養(yǎng)4代以上活力旺盛的腫瘤細(xì)胞作為靶細(xì)胞,用100 μL注射器及30#針頭接種于DBA/2小鼠的背部(2×105/50 μL)。實(shí)驗(yàn)小鼠接種24 h后隨機(jī)分為兩組,每組20只,作為對照組(生理鹽水)和給藥組(OK-432腫瘤疫苗),接種24 h后開始給藥,給藥方式為腹腔注射,每只100 μL(5×105個),每周1次,連續(xù)給藥3周。
1.5 腫瘤大小的測定
各組小鼠處理后每天觀察腫瘤大小,每隔5天測量腫瘤最大徑a和最小徑b, 計(jì)算腫瘤體積。腫瘤體積=a×b×b×0.52(mm3)。
1.6 抑瘤率及淋巴結(jié)轉(zhuǎn)移抑制率[3]
給藥3周后處死小鼠,摘取腋下、腹部、胭窩處的淋巴結(jié),根據(jù)淋巴結(jié)石蠟切片HE染色,計(jì)數(shù)淋巴結(jié)轉(zhuǎn)移數(shù), 剝離原發(fā)腫瘤,測定淋巴結(jié)重量,計(jì)算抑瘤率、淋巴結(jié)轉(zhuǎn)移率及轉(zhuǎn)移抑制率。
抑瘤率=(對照組平均瘤重-給藥組平均瘤重)/對照平均瘤重×100%;淋巴結(jié)轉(zhuǎn)移率=同組轉(zhuǎn)移小鼠數(shù)/同組小鼠數(shù)×100%;淋巴結(jié)轉(zhuǎn)移抑制率=(對照組淋巴結(jié)轉(zhuǎn)移率-給藥組淋巴結(jié)轉(zhuǎn)移率)/對照組淋巴結(jié)轉(zhuǎn)移率×100%。
1.7 淋巴結(jié)HE染色
用40 g/L甲醛固定液固定淋巴結(jié),常規(guī)方法石蠟包埋固定,制成4 μm的石蠟切片,進(jìn)行HE染色,觀察兩組淋巴細(xì)胞浸潤情況。
1.8統(tǒng)計(jì)學(xué)方法
應(yīng)用SPSS17.0軟件進(jìn)行數(shù)據(jù)分析,計(jì)量資料用(x±s)表示,組間比較采用方差分析,計(jì)數(shù)資料用相對數(shù)表示,采用χ2檢驗(yàn),P<0.05為差異有統(tǒng)計(jì)學(xué)意義。
2 結(jié)果
2.1 OK-432疫苗對DBA/2小鼠腫瘤增殖的抑制作用
腹腔注射OK-432疫苗及生理鹽水后,每隔5天測量一次腫瘤的大小,計(jì)算腫瘤體積。見表1,應(yīng)用SPSS17.0軟件進(jìn)行方差分析:5、10、15、20 d給藥組與對照組差異均有統(tǒng)計(jì)學(xué)意義(P<0.01),OK-432腫瘤疫苗可以抑制腫瘤生長。以天數(shù)為橫坐標(biāo),腫瘤的平均體積為縱坐標(biāo)繪制腫瘤生長曲線,見圖1。由圖1可見對照組腫瘤生長速度明顯高于給藥組。
表1 兩組腫瘤大小比較(x±s,mm3)
圖1 腫瘤生長曲線
2.2 兩組抑瘤率及淋巴結(jié)轉(zhuǎn)移抑制率比較
給藥3周后處死小鼠,摘取腋下、腹部、胭窩處的淋巴結(jié)(包括轉(zhuǎn)移瘤),計(jì)數(shù)淋巴結(jié)轉(zhuǎn)移數(shù),測定原發(fā)腫瘤重量,計(jì)算抑瘤率、淋巴結(jié)轉(zhuǎn)移率及轉(zhuǎn)移抑制率見表2。疫苗組原發(fā)淋巴結(jié)重量明顯低于對照組(P<0.01),抑瘤率為68.4%;淋巴結(jié)轉(zhuǎn)移率疫苗組(65%)低于對照組(95%),有統(tǒng)計(jì)學(xué)差異(P<0.05),淋巴結(jié)轉(zhuǎn)移抑制率為31.6%。OK-432腫瘤疫苗可以抑制腫瘤生長及腫瘤的淋巴結(jié)轉(zhuǎn)移。
表2 兩組淋巴結(jié)轉(zhuǎn)移情況比較
2.3 小鼠轉(zhuǎn)移淋巴結(jié)HE染色結(jié)果
從圖2可見,對照組淋巴結(jié)內(nèi)淋巴細(xì)胞明顯少于給藥組。OK-432疫苗可以促進(jìn)機(jī)體免疫應(yīng)答并可抑制腫瘤淋巴結(jié)轉(zhuǎn)移。
圖2 對照組(左)與給藥組(右)小鼠淋巴結(jié)HE染色病理切片
3 討論
腫瘤疫苗是用腫瘤細(xì)胞、腫瘤抗原或腫瘤細(xì)胞裂解物等激活機(jī)體免疫系統(tǒng)來產(chǎn)生抗腫瘤效應(yīng)。它是一種新型的、主動免疫治療腫瘤的方法[4]。OK-432[5-7]制劑是將A群溶血性鏈球菌(Su株)以苯基尼西林加熱處理并冷凍干燥之制劑,具有免疫活性作用。OK-432腫瘤疫苗[8,9]是把OK-432與KLN-205癌細(xì)胞通過戊二醛(GA)架橋劑交聯(lián),剔除未結(jié)合的剩余物而制成。
本實(shí)驗(yàn)通過給接種了肝癌腫瘤細(xì)胞的小鼠腹腔注射腫瘤疫苗,觀察腫瘤疫苗對小鼠腫瘤的抑制作用,結(jié)果顯示,OK-432腫瘤疫苗可以抑制腫瘤細(xì)胞生長,抑制腫瘤細(xì)胞的淋巴結(jié)轉(zhuǎn)移,能夠激活機(jī)體免疫,增強(qiáng)小鼠抗腫瘤能力。其抗腫瘤機(jī)制可能為:①OK-432腫瘤疫苗使菌體與癌細(xì)胞直接接觸,利用OK-432直接殺傷癌細(xì)胞的作用使腫瘤細(xì)胞變性,能使細(xì)胞膜和細(xì)胞內(nèi)的腫瘤抗原得到加工呈遞與外露,從而腫瘤細(xì)胞“隱藏”著的某些抗原決定簇被暴露,使腫瘤抗原性增強(qiáng)得到增加[10,11]。②OK-432腫瘤疫苗可以激活宿主CD4+Th1細(xì)胞主導(dǎo)的細(xì)胞免疫,增強(qiáng)巨噬細(xì)胞和NK細(xì)胞的抗腫瘤作用,從而誘發(fā)CTL應(yīng)答,使荷瘤小鼠腫瘤的生長得到顯著抑制,延長小鼠生命,激發(fā)和增強(qiáng)宿主的特異性免疫功能[12]。
綜上所述,OK-432腫瘤疫苗不僅可以抑制腫瘤的生長,而且可以增強(qiáng)機(jī)體免疫應(yīng)答,并可抑制腫瘤的轉(zhuǎn)移,值得臨床上推廣應(yīng)用。
[參考文獻(xiàn)]
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(收稿日期:2014-07-29)