负载肿瘤抗原的DC体外诱导抗肿瘤免疫反应的实验研究

目的 研究自体及同种异体树突状细胞(DC)体外负载肿瘤抗原后刺激T淋巴细胞增殖及诱导抗肿瘤免疫反应的能力.方法 利用细胞因子诱导人骨髓单个核细胞生成DC,尼龙毛柱法分离T淋巴细胞,3H-TdR掺入法检测负载肺癌细胞凋亡小体的自体及同种异体DC体外刺激T细胞增殖反应,乳酸脱氢酶(LDH)释放法检测负载肺癌细胞凋亡小体的自体及同种异体DC刺激的T细胞对肺癌细胞和乳腺癌细胞系MCF-7的杀伤作用.结果 骨髓细胞诱生的自体及同种异体DC负载肿瘤抗原后,均具有刺激T淋巴细胞增殖的能力,负载肿瘤抗原的自体及异体DC激活的T淋巴细胞后均可杀伤两种靶细胞,T细胞对MCF-7的杀伤力明显低于对患者肺癌细胞的杀伤力. 结论人自体或异体DC体外负载细胞性肿瘤抗原后,可有效地刺激T淋巴细胞的增殖,产生特异性肿瘤杀伤作用.     

体外负载HSP70-K-ras突变多肽复合物树突细胞的抗胰腺癌作用

背景：K-ras突变多肽难以很好地被树突细胞（DC）捕获,诱导的抗肿瘤效应有限。目的：探讨热休克蛋白70（HSP70）-K-ras突变多肽复合物体外负载于DC的抗胰腺癌作用。方法：使HSP70与K-ras突变多肽在体外结合成复合物,负载于由人外周血单个核细胞体外诱导分化获得的DC。酶联免疫吸附测定（ELISA）检测DC的细胞因子分泌能力,流式细胞仪分析DC负载抗原前后的细胞表型变化,胆囊收缩素（CCK）-8法检测负载抗原后DC对同基因淋巴细胞的促增殖作用,以及激活的同基因淋巴细胞对人胰腺癌细胞株Patu8988、PANC-1和正常人肝细胞株L-02的细胞毒作用。结果：HSP70-K-ras突变多肽复合物可激活DC,最适浓度为0.75μg/ml,可使DC的白细胞介素（IL）-12、肿瘤坏死因子（TNF）-α分泌量和细胞表面CD80、CD83、CD86、HLA-DR表达率显著增高。0.75μg复合物可有效激活1×10^6个DC,刺激1×10^7个同基因淋巴细胞增殖,特异性杀伤具有相同12位点突变类型（GGT→GTT）的Patu8988细胞,杀伤率达52.9%±5.1%,对不同突变类型的PANC-1细胞（GGT→GAT）和正常人肝细胞杀伤作用不明显。结论：负载HSP70-K-ras突变多肽复合物的DC活性增强,可刺激同基因淋巴细胞产生高效而特异的抗胰腺癌效应。     

体外负载冻融抗原的脐血树突状细胞诱导的抗肝癌效应

目的评价体外应用肝癌细胞冻融抗原负载的脐血树突状细胞（DC）所诱导的抗肝癌效应。方法采集健康足月剖宫产孕妇胎盘端脐血,分离脐血单个核细胞（CBMNC）及T淋巴细胞,用GM-CSF、IL-4及TNF-α联合诱导CBMNC分化为DC,观察形态学变化并以流式细胞术鉴定,选培养的第3天以肝癌细胞冻融抗原负载的CBMNC-DC,以负载抗原的DC刺激自体淋巴细胞活化为自体细胞毒性T淋巴细胞（CTL）,并用CTL对肝癌细胞进行杀伤,MTT法测定活化的自体淋巴细胞的相对数量和CTL对肝癌细胞的杀伤率。结果体外负载肿瘤冻融抗原的脐血DC可诱导显著的自体效应淋巴细胞增殖及抗肝癌效应。结论体外负载抗原的脐血DC可诱导显著的抗肝癌效应,是具有临床应用前景的肝癌疫苗。     

树突状细胞负载甲胎蛋白、细胞毒性T细胞表位肽后的免疫应答

目的 用负载hAFP 218-226位LLNQHACAV九肽的树突状细胞（dendritic cells,DC)诱导自身淋巴细胞，使之活化为肝细胞癌（HCC）特异性细胞毒性T细胞（cytotoxic T lymphocyte,CTL)，并特异性杀伤HCC细胞。方法 在体外用GM-CSF和IL-4诱导HLA-A2^ 健康志愿者外周血单核细胞，使其分化为高纯度DC。用负载hAFP 218-226位LLNQHACAV九肽的DC诱导自身淋巴细胞，使之成为HCC特异性CTL。结果 诱导的DC分泌较高水平的IL-12（17.6-21.5pg/ml)，其中以第7天为最高（21.5pg/ml)，经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中TNF水平均比在IL-2条件下培养的未活化淋巴细胞高。L929细胞死亡百分率分别为80.65和11.6%；经DC和DC负载AFP表位肽后活化的淋巴细胞培养上清液中IL-12水平分别为20.5pg/ml和46.9pg/ml，经DC活化后淋巴细胞增殖指数大于3。活化后的淋巴细胞不但特异性杀伤HLA-A2^ 的HCC细胞HepG2和负载AFP表位肽的T2细胞，而且还不同程度杀伤HLA-A3^ HCC细胞Alexander和其它表型HCC细胞，对NK细胞敏感的靶细胞慢性髓原白血病细胞K562也有较强的杀伤作用。结论 负载hAFPHLA-A2限制性CTL九肽的DC对表达AFP HCC的研究和治疗有潜在应用价值。     

负载酸洗脱食管癌抗原肽的脐血树突状细胞对CTL杀伤活性的影响

分离脐血中的单个核细胞,以酸洗脱食管癌抗原肽负载获得分化成熟树突状细胞（DCs）,检测其对特异性细胞毒T淋巴细胞（CTL）的诱导和体外杀伤效应的影响。结果发现,负载食管癌抗原肽的脐血DCs诱导的CTL对酸洗前食管癌细胞株T.Tn的杀伤率显著高于酸洗后组和各对照组（P均〈0．05）,而对无关肿瘤细胞株Hep2无显著杀伤作用。认为负载食管癌抗原肽的脐血DCs体外可诱导CTL产生特异性杀伤效应。     

两种不同抗原致敏方式负载DC疫苗对Lovo细胞的体外杀伤作用

目的比较重组痘苗病毒负载人癌胚抗原（CEA）基因转染方式与Lovo细胞裂解物诱导方式对产生DC疫苗的影响。方法分别采用重组痘苗病毒负载CEA基因转染方式及Lovo肿瘤细胞裂解物转染方式转染未成熟DC,诱导特异性细胞毒性T淋巴细胞（CTL）。体外培养CTL并检测其活性;MTT法检测两组CTL对kovo细胞的杀伤作用。结果两种方式致敏DC均可诱导激活CTL并分泌INF-γ,而重组痘苗病毒转染Dc组CTL诱导率高于细胞裂解物组;重组痘苗病毒转染组诱导的CTL对Lovo细胞的特异性杀伤活性显著高于细胞裂解物组。结论两种不同抗原致敏方式负载DC疫苗均能够诱导高效而特异的CTL杀瘤活性,而使用重组痘苗病毒转染CEA至DCs的方式明显优于肿瘤细胞裂解物的抗原负载方式,为DC疫苗用于结肠癌的免疫治疗奠定基础。     

树突状细胞疫苗治疗慢性乙型肝炎的临床观察

形成慢性乙型肝炎的重要原因之一是树突状细胞（DC）功能缺陷。已知DC是功能最强的抗原递呈细胞，也是惟一能激活初始型T淋巴细胞的抗原递呈细胞，在T淋巴细胞介导的细胞免疫中起重要作用。当用特异性病毒抗原负载DC时，有可能通过诱导抗原特异细胞毒性T淋巴细胞（CTL）活性而特异性杀伤表达病毒抗原的靶细胞。     

负载胰腺癌抗原的树突状细胞疫苗诱导T淋巴细胞抗肿瘤效应的研究

培养树突状细胞(DC),反复冻融法裂解培养的负载胰腺癌细胞(PC-3),提取细胞抗原,致敏DC,获得负载胰腺癌抗原的DC疫苗后诱导特异性细胞毒性T淋巴细胞(CTL)的生成,MTT法检测CTL对不同肿瘤细胞的杀伤作用.发现负载PC-3细胞抗原的DC疫苗能诱导产生肿瘤特异性的CTL,其对PC-3细胞具有明显地杀伤效应,而对人乳腺癌细胞MCF-7、人肝癌细胞7721细胞杀伤作用弱.认为负载胰腺癌抗原的DC疫苗能够诱导高效而特异地CTT杀瘤活性,为将来DC疫苗在胰腺癌的免疫治疗中提供了实验依据.     

负载MB49肿瘤细胞抗原的DC疫苗对膀胱癌的抑制效应及机制

目的探讨负载MB49肿瘤细胞抗原的树突状细胞疫苗（DC疫苗）治疗膀胱癌的可行性及机制。方法采用反复冻融法提取MB49抗原并用其致敏DC2.4,制备DC疫苗。将24只膀胱癌荷瘤小鼠随机分为两组各12只。DC组皮下注射DC疫苗,对照组注射PBS。注射3周观察两组肿瘤体积变化,计算肿瘤抑制率;分离两组脾脏T淋巴细胞进行培养,MTT法检测细胞毒性T淋巴细胞（CTL）对MB49的杀伤率;ELISA法检测培养上清中IFN-γ水平。结果 DC组肿瘤抑制率及细胞杀伤率均明显高于对照组,P〈0.01;IFN-γ水平亦明显高于对照组,P〈0.01。结论以DC2.4为基础的DC疫苗体内具有抑制肿瘤细胞MB49增长的作用;其机制可能为激活T淋巴细胞。     

K562细胞可溶性抗原负载树突状细胞体外诱导CTL作用的研究

目的探讨经K562细胞裂解物冲击致敏的外周血单个核细胞衍生的树突状细胞（DC）的生物特性及体外诱导抗原特异性CTL应答的能力。方法采集健康人抗凝外周血分离单个核细胞，贴壁细胞用含rhGM—CSF、rhIL-4、TNF—α的RPM1640＋10％FBS培养基体外诱导培养产生DC，5天收获细胞并将细胞分组：A组：未负载抗原DC；B组：加入K562细胞裂解液脉冲DC。7天后用流式细胞仪检测成熟DC免疫表型，并将非贴壁细胞（淋巴细胞）作为效应细胞与各组DE共育，以产生细胞毒性T淋巴细胞（CTL）。12天用LDH释放试验测定对K562细胞的杀伤活性。并用ELISA方法测定细胞上清液中IL-12的含量。结果（1）经细胞因子联合体外诱导的各组DC较培养前在数量，形态及免疫表型上差异有统计学意义，CD86、CD83、CD40、CD1a表达增加，其中经K562细胞裂解液冲击的DC的CD83CD86表达率明显升高。（2）效应细胞与K562细胞混合培养时，负载K562细胞裂解液的DC刺激后的T细胞比单独DC刺激后的T细胞对K562细胞的杀伤作用更明显。（3）负载K562细胞裂解液的DC细胞培养上清液中产生IL-12含量较未负载抗原的DC明显增加。结论用GM—CSF、IL-4以及TNF—α诱导培养健康人外周血单个核细胞可以得到成熟的DC，且经K562细胞裂解液致敏可以进一步促进DC的成熟并体外诱导特异性杀伤靶细胞的CTL。     

Experimental and clinicopathologic study on the relationship between transcription factor Egr-1 and esophageal carcinoma

AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore the potential application of Egr-1 gene in gene therapy of tumor. METHODS: Eukaryotic expression vector of PCMV-Egr-1 plasmid was introduced into Eca109 cell line which expressed no Egr-1 protein originally with lipofectamine transfection method. The introduction and expression of PCMV-Egr-1 plasmid into Eca109 cell line was confirmed by G418 selection culture, PCR amplification of neogene contained in the vector, Western blot analysis and immunocytochemical analysis. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous Egr-1 gene on Eca109 cell line. The Egr-1 mRNA and Egr-1 protein were also detected in 50 surgical specimens of esophageal carcinoma by in situ hybridization and immunohistochemistry. RESULTS: Exogenous Egr-1 gene was introduced successfully into Eca109 cell line and expressed Egr-1 protein stably. The transfected Eca109 cell line grew more slowly than control Eca109 as shown by cell growth curves, the soft agar colony formation rate (4.0% vs 6.9%, P < 0.01) and the average growth rate of tumor in SCID mice (35.5 +/- 7.6 vs 65.8 +/- 7.6, P < 0.05). The expression level of Egr-1 mRNA and protein significantly increased in dysplastic epithelia adjacent to cancer rather than in cancer tissues (65.8% vs 20.0% by ISH and 57.9% vs 0.01). CONCLUSION: Exogenous Egr-1 gene shows the strong effect of growth inhibition in Eca109 cell line. Egr-1 in the cancer tissue shows down-regulated expression that supports the inhibited function of Egr-1 in cancer growth and suggests Egr-1 may have an important role in gene therapy of esophageal carcinoma.     

Angiopoietin-1 targeted RNA interference suppresses angiogenesis and tumor growth of esophageal cancer

AIM： To determine the inhibitory effect of the adenovirusbased angiopoietin-1 （Ang-1） targeted small interfering RNA expression system （Ad/Ang-1si） on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109. METHODS： siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si （Eca109/Ang-1si）, and Ad/si was used to infect Eca109 cells as control （Eca109/si）. Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell （HUVEC） migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined. RESULTS： HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirustransfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased. CONCLUSION： The targeting Ang-1 may provide a therapeutic option for esophageal cancer.     

^18F-FETNIM在食管癌ECa109细胞乏氧监测中的应用

目的探讨乏氧显像剂^18F-氟赤式硝基咪唑（^18F—FETNIM）在食管癌细胞ECa109乏氧监测中的应用价值。方法传代至2～3代的ECa109细胞,常氧环境下分别予以0、2、4、6、8Gyx线照射,加入等量”F．FETNIM显像剂后分别于5、30、60、120、180min用γ井型测量仪测定其放射性计数,计算摄取率。结果^18F—FETNIM在ECa100细胞中的摄取,0Gy组细胞的摄取率随时间延长而增高,180min达最高,其余各组细胞随照射剂量增加,摄取率峰值逐渐前移,且峰值均高于0Gy组。结论^18F—FETNIM可用于食管癌细胞乏氧情况监测,为临床优化化疗方案提供依据。     

Role of stress-activated MAP kinase P38 in cisplatin- and DTT-induced apoptosis of the esophageal carcinoma cell line Eca109

AIM: To study the role of P38 kinase in esophageal cancer cell apoptosis induced by genotoxin, cisplatin and the unfolded protein response (UPR) inducer, dithiothreitol (DTT). METHODS: Esophageal carcinoma cell line Eca109 was cultured in RPMI 1640 medium to 70% confluency and treated with either cisplatin, DTT, or cisplatin plus DTT in the presence or absence of P38 inhibitor, SB203580. The untreated cells served as the control. The esophageal carcinoma cell apoptosis was detected by agarose gel DNA ladder analysis and quantified by flow cytometry. The P38 phosphorylation was detected by immunohis-tochemistry using antibodies specific to phosphorylated P38 protein. RESULTS: (1) Both cisplatin and DTT induced apoptosis in the esophageal cancer cell line Eca109 as shown by DNA ladder formation; (2) As detected by antibodies specific for the phosphorylated P38 protein (p-P38), both cisplatin and DTT treatments activated the stress-activated enzyme, MAP kinase P38. The number of positive cells was about 50% for the treatment groups, comparing to that of 10% for untreated group. DTT treatment, but not cisplatin treatment, induces nuclear localization of p-P38; (3) As measured by flow cytometry, inhibition of P38 activity by SB203580 blocks DTT- and cisplatin-induced apoptosis. The rates for DTT, cisplatin, and DTT plus cisplatin-induced apoptosis were 16.8%, 17.1%, and 21.4%, respectively. Addition of the SB compound during the incubation reduced the apoptotic rate to about 7.6% for all the treatment groups, suggesting that P38 activation is essential for cisplatin- and DTT-induced apoptosis in Eca109 cells. CONCLUSION: (1) Both DTT and cisplatin were able to induce apoptosis in esophageal cancer cell line Eca109; (2) P38 MAP kinase is essential for DTT- and cisplatin- induced apoptosis in Eca109 cells; (3) P38 activation may be the common signaling component relaying the multiple upstream signaling events to the downstream cell death program.     

新疆哈萨克族食管鳞癌中微小RNA let-7的表达及病理生物学意义

目的探讨微小RNA（miRNA）let-7在食管鳞癌细胞及组织中的表达,及let-7与食管鳞癌临床病理的关系。方法在细胞水平,运用实时荧光定量聚合酶链反应（real-time quantitative PCR,qRT-PCR）检测let-7在正常食管鳞状上皮细胞Heepic及食管鳞癌细胞CaES-17、Eca109和KYSE-150中的表达差异;在组织水平,采用qRT-PCR技术检测let-7在15对哈萨克族食管鳞癌组织和癌旁正常组织中的表达,并分析其与食管鳞癌浸润、转移等临床病理的关系。结果 qRT-PCR结果显示,let-7在3个食管鳞癌细胞系中的表达明显低于在正常食管鳞状上皮细胞Heepic中的表达,let-7在食管鳞癌组织中的表达明显低于其在癌旁正常组织中的表达,其相对表达量比值为0.79±0.56,差异有统计学意义（P〈0.05）;let-7在不同性别、分化程度、大体分型、浸润深度及淋巴结转移之间的相对表达量比值均无统计学差异（P〉0.05）。结论 Let-7在正常食管鳞状上皮细胞和食管鳞癌细胞中均有表达,但在食管鳞癌细胞中呈低表达;let-7在食管鳞癌组织和正常食管鳞状上皮组织中均有表达,但在癌组织中呈显著低表达;哈萨克族食管鳞癌患者let-7低表达与其临床病理参数之间无显著相关性;let-7对哈萨克族食管鳞癌的发生起抑制作用,是食管鳞癌的潜在分子标记物。     

脂质体槲皮素对食管癌细胞增殖及蛋白表达的影响及机制

目的比较不同脂质体槲皮素对人食管癌Eca109和Eca9706细胞增殖的作用,并初步探讨其作用机制。方法采用旋转蒸发法制备氯仿和甲醇溶解类脂物质的脂质体槲皮素LQ1和按同比例的氯仿和DMSO作为溶剂的脂质体槲皮素LQ2,用DMSO直接溶解槲皮素制备非脂质体槲皮素nLQ,分别作用于Eca109和Eca9706细胞（分别作为LQ1、LQ2及nLQ组）,同时设立对照组。MTT实验检测各组细胞抑制率,免疫组织化学染色和免疫印迹法检测磷酸酶基因（PTEN）和细胞周期素D1（Cychn D1）蛋白表达。结果各组细胞增殖的抑制效应、上调PTEN和下调Cyclin D1蛋白表达的效应呈现同一趋势,即LQ2组〉LQ1组〉nLQ组〉对照组,P〈0．05。结论脂质体槲皮素对食管癌细胞增殖有抑制作用,LQ2的抑制率高于LQ1;上调PTEN表达、下调Cyclin D1表达可能为其作用机制之一。     

Effect of S1P5 on proliferation and migration of human esophageal cancer cells

AIM:To investigate the sphingosine 1phosphate (S1P) receptor expression profile in human esophageal cancer cells and the effects of S1P5 on proliferation and migration of human esophageal cancer cells. METHODS: S1P receptor expression profile in human esophageal squamous cell carcinoma cell line Eca109 was detected by semiquantitative reverse trans cription polymerase chain reaction. Eca109 cells were stably transfected with S1P5EGFP or controlEGFP constructs. The relation between the responses of cell prol...     

EpCAM expression in esophageal cancer and its correlation with immunotherapy of solitomab

BackgroundRecurrence of esophageal cancer (EC) after chemotherapy may mainly be explained by the existence of chemotherapy-resistant cells, and an effective drug against chemotherapy-resistant cells is highly sought. The aim of this study was to investigate the cytotoxicity of bispecific antibody solitomab combined with γ δ T cells on Eca109 cell spheres.MethodsWe cultured Eca109 cell spheres in serum-free medium, and the morphological differences between wild-type Eca109 cells and Eca109 cell spheres were compared by microscope and flow cytometry. Different concentrations of nanoparticle albumin-bound paclitaxel (Nab-PTX) and cisplatin were used to treat the two groups of cells and compare their drug resistance. Flow cytometry was then used to detect the expression level of epithelial cell adhesion molecule (EpCAM) and the cytotoxicity of γ δ T cells combined with bispecific antibody solitomab on the two groups.ResultsFlow cytometry analysis showed that Eca109 cell spheres were smaller in size and had less cytoplasmic granules and CCK-8 assay showed that the viability of Eca109 cell spheres treated with different concentrations of Nab-PTX and cisplatin was significantly higher than that of wild-type Eca109 cells (P<0.05). Flow cytometry also showed that the expression level of EpCAM on Eca109 cell spheres was higher than that of wild-type Eca109 cells. Co-culture experiment showed that there was no significant difference in the cytotoxicity of γ δ T cells to wild-type Eca109 cells and Eca109 cell spheres without solitomab. However, after adding solitomab, the cytotoxicity of γ δ T cells to Eca109 cell spheres was significantly higher than that of wild-type Eca109 cells (P<0.05).ConclusionsEC Eca109 cell spheres have strong stem cell characteristics such as multidrug resistance and may contain a high proportion of EC stem cells. Further, EC Eca109 cell spheres have a high expression level of EpCAM, and EpCAM may be one of the markers of EC stem cells. Therefore, EpCAM could be used as a potential molecular target of immunotherapy for EC, and solitomab may become an effective immunotherapeutic drug for chemotherapy-resistant EC cells.     

缺氧诱导因子-1α与EphA2在食管鳞状细胞癌中的表达及其相关性研究

目的 检测缺氧诱导因子-1α (HIF-1α) 蛋白与EphA2蛋白在食管鳞状细胞癌中的表达定位并探讨二者表达的相关性.方法 采用细胞免疫荧光法检测HIF-1α与EphA2在食管鳞状细胞癌细胞株Eca109中的表达与定位;采用免疫组化法检测HIF-1α与EphA2在41例食管鳞状细胞癌和25例正常食管组织中的表达;常氧和缺氧条件下,Western 印迹法检测食管鳞状细胞癌细胞株Eca109和TE13经RNA干扰(RNAi)技术特异性沉默HIF-1α后EphA2表达的变化.结果 ①细胞免疫荧光结果显示HIF-1α和EphA2均在Eca109细胞胞质表达.②免疫组化结果显示HIF-1α在食管鳞状细胞癌和正常食管组织中的阳性表达率分别为70.73%(29/41)和0%(0/25),两者比较差异有统计学意义(P<0.05).EphA2在食管鳞状细胞癌和正常食管组织中的阳性表达率分别为78.04%(32/41)和28%(7/25),两者比较差异有统计学意义(P<0.05).相关性检验提示HIF-1α和EphA2在食管鳞状细胞癌中表达呈正相关性(r=0.5654,χ~2=13.11,P<0.05).③ Western印迹结果显示在食管鳞状细胞癌细胞株Eca109和TE13中,EphA2表达随HIF-1α的沉默而受抑制.结论 HIF-1α与EphA2在食管鳞状细胞癌组织中呈高表达,且二者表达呈正相关;EphA2表达受HIF-1α的调控,可能为HIF-1α的靶基因.