全反式维甲酸提高激素非依赖性前列腺癌自杀基因治疗的旁观者效应

目的:观察全反式维甲酸(ATRA)提高单纯疱疹病毒胸苷激酶(HSV-TK)/丙氧鸟苷(GCV)系统体内外抗激素非依赖性前列腺癌的旁观者效应。方法:应用四甲基偶氮唑蓝(MTT)法测定细胞存活率来反映ATRA处理前后HSV-TK/GCV系统治疗PC-3细胞的旁观者效应;荷前列腺癌裸鼠模型随机分为4组,观察各组移植瘤生长状态和组织病理学改变。结果:在达到明显旁观者效应时,HSV-TK/GCV需要TK+PC-3细胞数为50%,而ATRA联合HSV-TK/GCV需要TK+PC-3细胞数仅为30%,两者比较差异显著(P<0.05)。HSV-TK可以抑制移植瘤生长,但ATRA+HSV-TK抗前列腺癌发生显效可提前1周,而且效果更显著(P<0.05)。结论:ATRA可增强HSV-TK/GCV系统治疗激素非依赖性前列腺癌的旁观者效应。     

Pancreatic carcinoma cell killing via adenoviral mediated delivery of the herpes simplex virus thymidine kinase gene.

OBJECTIVE: Use of adenoviral mediated delivery of the herpes simplex virus thymidine kinase (HSV-TK) gene as a gene therapy strategy for carcinoma of the pancreas. SUMMARY BACKGROUND DATA: Expression of HSV-TK selectively sensitizes cells to the nucleoside analog ganciclovir (GCV). This strategy has been used to treat other compartmentalized tumor models. Therefore, the containment of pancreatic carcinoma makes it amenable to this gene therapy approach. METHODS: A recombinant adenoviral vector encoding the HSV-TK gene was used to induce GCV sensitivity and test the potential bystander effect in established pancreatic carcinoma cell lines and patient-derived tumor material. Additionally, Balb/C nude mice were injected intraperitoneally with human pancreatic carcinoma cells and treated with GCV (50 mg/kg per day) for 14 days. RESULTS: Expression of the HSV-TK gene elicited a significant bystander effect in the presence of GCV. Pancreatic tumor cells injected intraperitoneally into nude mice resulted in significant tumor formation. Treatment of animals with AdCMVHSV/HSV-TK and GCV induced a dramatic decrease in overall tumor burden for up to 8 weeks post-GCV treatment. CONCLUSIONS: Pancreatic carcinoma cells are highly susceptible to transduction with recombinant adenoviral vector and elicit a potent bystander effect on neighboring tumor cells. Additionally, in vivo treatment of tumor-bearing animals results in dramatic reduction of overall tumor burden, thus providing the rationale for molecular chemotherapy of pancreatic carcinoma.     

HSV-TK/GCV系统体外对膀胱癌细胞的旁观杀伤作用

目的 探讨单纯疱疹病毒胸苷激酶（HSV－TK）基因联合羟基无环鸟苷（GCV）对膀胱癌细胞的旁观杀作作用及其机制。方法 将转染HSV－TK基因的膀胱癌细胞（BIU 87－TK）分别与人膀胱癌细胞（BIU 87、T 24）和鼠膀胱癌细胞（T 739）混合培养。在GCV作用下,观测细胞的存活情况及BIU 87－TK条件培养液和细胞死亡裂解对共培养细胞的影响。结果 当BIU 87－TK细胞占50％时,共培养细胞对GCV的敏感性与100％ BIU 87－TK细胞一致。表明每个表达HSV－TK基因的细胞能杀死至少一个不含HSV－TK基因的膀胱癌细胞。BIU 87－TK细胞的条件培养液对BIU 87亲本细胞的生长无影响。G 418诱导的细胞裂解与对其共培养的BIU 87－TK细胞无旁观毒性作用。结论 HSV－TK／GCV对膀胱癌细胞产生的“旁观者”效应是该系统特异性的毒性作用。“旁观者”效应不仅可在人膀胱癌不同细胞株之间产生,而且不局限于某一种属的膀胱癌细胞之间。     

单纯疱疹病毒胸苷激酶基因和更昔洛韦对膀胱癌细胞的旁观杀伤效应

目的：探讨单纯疮疹病毒胸苷激酶（HSV-tk）基因和更昔洛韦（GCV）对膀胱癌细胞的旁观者效应和机制。方法：将转染HSV-tk基因的膀胱癌细胞HTB9与HTB9细胞混合培养，在GCV作用下，观测细胞的存活率。HTB9-tk细胞条件培养基，经不同孔径的滤膜过滤，将滤液及0.22μm滤膜上的物质重新加入HTB9细胞，观察细胞存活率。结果：当HTB9-tk细胞50％时，共培养细胞对GCV的敏感性近100％，表明每个表达HSV-tk基因的细胞至少杀死1个不含HSV-tk基因的膀胱癌细胞。HTB9-tk细胞的条件培养液过滤后直径大于0.22μm的某种物质对HTB9细胞具有细胞毒性作用。结论：HSV-tk/GCV对膀胱癌细胞具有明显旁观者效应的毒性作用，直径大于0.22μm的某种物质对HTB9细胞具有细胞毒性作用，其旁观杀伤效应机理可能是HTB9对HTB9-tk细胞凋亡囊泡的吞噬。     

HSV-TK/ACV系统促肾癌细胞株GRC-1细胞凋亡的实验研究

目的：观察HSV－TK／ACV系统对肾癌GRC－1细胞的杀伤作用及旁观者效应。方法将含不同浓度的肾癌GRC－1／TK细胞与肾癌GRC－1细胞混合培养,分为4组,分别含GRC－1／TK细胞0％、25％、50％及100％,分别用无环鸟苷60μg/ml进行处理,观察细胞形态改变、测定活细胞数并行流式细胞术、电子显微镜检查。结果实验组与对照组GRC－1细胞均无明显变化;含25％以上GRC－1／TK细胞可观察到明显的杀伤作用,并有凋亡峰及凋亡小体形成。结论HSV－TK／ACV系统对肾癌GRC－1细胞具有明显的杀伤作用及旁观者效应,机制可与细胞凋亡有关。     

经肝动脉或瘤体注射单纯疱疹病毒-胸苷激酶基因治疗兔肝癌

目的　观察瘤体内直接注射或经肝动脉注射载有单纯疱疹病毒胸苷激酶 (HSV TK)基因的EB病毒表达质粒 pDR2 /TK、丙氧鸟苷 (GCV )对原位兔肝癌的治疗效果。 方法　制作兔原位肝癌模型 (VX2 ) ,瘤体注射或经肝动脉注射质粒 pDR2 /TK ,腹腔注射GCV连续 10d。RT PCR检测肝癌HSV TK表达 ;螺旋CT监测肝癌大小 ,并观察兔存活时间。结果TK基因导入 10d后 ,直接注射组TK在肝癌组织强表达 ,癌旁组织弱表达 ,正常肝组织不表达 ;肝动脉注射组TK基因在肝癌表达稍强于癌旁及正常肝组织。直接注射组肿瘤大小 ( 3 .5 5± 0 .3 9)cm ,与经肝动脉注射+肝动脉结扎组肿瘤大小 ( 3 .70± 0 .3 7)cm无明显差别 (P >0 .0 5 ) ,但均明显小于对照组。瘤体直接注射TK基因 +GCV治疗组动物平均存活时间 ( 5 9.8± 3 .3 )d、肝动脉注射组 +肝动脉结扎组( 5 4.8± 4.5 )d明显长于各对照组 (P均 <0 .0 1)。结论　对实验性兔肝癌 ,瘤体内直接注射或经肝动脉注射导入治疗基因后 ,HSV TK/GCV系统具有较好的治疗效果。     

腺病毒介导自杀基因对消化系统肿瘤的杀伤作用

目的观察腺病毒介导的自杀基因对消化系肿瘤的杀伤作用。方法腺病毒介导的自杀基因HSV-TK分别转染结肠癌LOVO细胞、胃癌MGL-803细胞和肝癌BEL-7402细胞,比较腺病毒载体对不同肿瘤细胞的转染效率。加入前药丙氧鸟苷(GCV),通过MTT法检测细胞存活率,观察单纯疱疹病毒1型胸苷激酶/丙氧鸟苷(HSV-TK/GCV)系统对不同肿瘤细胞的杀伤作用和旁观者效应。结果在GCV浓度100mg/L以上时,3种转基因肿瘤细胞均可被HSV-TK/GCV系统完全杀伤;旁观者效应以MGL-803细胞最为明显,与LOVO细胞和BEL-7402细胞相比,差异有显著性意义(P<0.05);腺病毒对肿瘤细胞的转染效率强弱依次为BEL-7402细胞、MGL-803细胞和LOVO细胞。结论重组腺病毒可以作为消化系肿瘤基因治疗的高效载体。HSV-TK/GCV系统对胃癌MGL-803细胞的作用最佳。     

角蛋白19启动子介导自杀基因的肿瘤细胞凋亡研究

目的探讨角蛋白19（keratin19，K19）启动子驱动单纯疱疹病毒胸苷激酶（HSV．-TK）基因这一载体系统对肿瘤细胞凋亡的影响。方法构建K19启动子驱动的HSV-TK载体pK19-TK，分别转染鼠转化角质细胞系、人肺癌细胞系和两种宫颈癌细胞系，MYr和流式细胞法检测前体药物丙氧鸟苷（GCV）对肿瘤细胞的杀伤作用。结果成功构建出pK19-TK质粒；两种细胞系在转染后产生了对GCV的敏感性，以鼠转化角质细胞系（PAM212细胞系）为例，加入2ixmol／LGCV后有19．4％的细胞死亡，加入10ixmol／LGCV和100txmol／LGCV分别有44．4％、58．7％的细胞被杀死。结论利用肿瘤细胞的角蛋白19表达特性来诱导细胞死亡在上皮细胞来源肿瘤的基因治疗中有潜在的应用价值。     

单纯疱疹病毒胸苷激酶/丙氧鸟苷系统对膀胱癌体内杀伤作用的研究

目的：探讨逆转录病毒介导的单纯疤疹病毒胸苷激酶／丙氧鸟苷(HSV-TK／GCV)系统对膀胱癌的体内杀伤作用。方法：用逆转录病毒载体感染鼠源性膀胱癌细胞株T739，体外观察其对GCV的敏感性。在鼠源性T739膀胱癌动物模型中，以逆转录病毒单次或重复感染方法介导TK基因转移，观察GCV治疗前后肿瘤体积大小及动物存活时间变化。结果：TK基因导入T739后获得了GCV敏感性，体内肿瘤生长受到抑制，动物存活时间延长，但单次和重复感染组之间无差别。结论：逆转录病毒成功介导膀胱癌体内基因转移，HSV-TK／GCV系统在体内对膀胱癌有杀伤作用，其可望对膀胱癌作为基因治疗。     

逆转录病毒介导单纯疱疹病毒-胸苷激酶基因对胰腺癌细胞的杀伤作用

目的：观察单纯疱疹病毒－胸苷激酶（HSV－tk)／丙氧鸟苷（GCV）基因治疗系统在体内外对人胰腺癌细胞的杀伤效应。方法：构建含HSV－tk基因的重组逆转录病毒载体pDOR-tk-neo,经病毒包装细胞PA317产生重组逆转录病毒,后者将HSV－tk基因转入人胰腺癌细胞系PC－2细胞内,筛选出稳定表达HSV－tk的细胞克隆PC－2／tk。测定PC－2/tk细胞在体外对GCV的敏感性及其旁观杀伤效应PC－2／tk细胞在裸鼠皮下成瘤,观察GCV的治疗作用。结果：GCV对PC－2/tk细胞有明显的杀伤作用,且其作用呈现剂量和时间依赖性特点以及旁观杀伤效应,对母本细胞则无明显毒性。裸鼠腹腔注射GCV后对移植瘤有明显治疗作用。结论：表达HSV－tk的人胰腺癌细胞在体内外均可被GCV有效杀伤。     

Cancer gene therapy using a replication-competent herpes simplex virus type 1 vector.

OBJECTIVE: The authors investigate the efficacy of hrR3, a viral vector derived from herpes simplex virus type 1 (HSV 1), in destroying colon carcinoma cells in vitro and in vivo. The effect of adding the prodrug ganciclovir in combination with hrR3 infection also is assessed. SUMMARY BACKGROUND DATA: Most cancer gene therapy strategies use viral vectors that are incapable of replication. The HSV 1 vector hrR3 is capable of replication, and its replication is cytotoxic to cells. hrR3 also possesses the HSV-thymidine kinase gene, which converts ganciclovir into a toxic metabolite. Thus, the addition of ganciclovir to hrR3-infected cells may enhance the ability of hrR3 to destroy tumor cells. To increase specificity for tumor cells, hrR3 has a mutated ribonucleotide reductase gene and replicates selectively in cells with high levels of endogenous rbonucleotide reductase. Actively dividing cells such as tumor cells have high levels of endogenous ribonucleotide reductase for synthesis of DNA precursors. The authors are interested in the use of HSV 1 vectors to treat liver metastases from colorectal cancer. METHODS: Ribonucleotide reductase expression in several colon carcinoma cell lines and in primary cultures of human hepatocytes was determined by Western blot analysis. hrR3-mediated cytotoxicity in the colon carcinoma cell lines was determined using an in vitro assay. The human colon carcinoma cell line HT29 was injected into the flanks of nude mice followed by intratumoral injection of hrR3. Tumor growth rate was assessed with and without the addition of intraperitoneal ganciclovir. RESULTS: Ribonucleotide reductase levels in colon carcinoma cell lines are much higher than in primary cultures of human hepatocytes. hrR3 efficiently destroys colon carcinoma cell lines in vitro. A single intratumoral injection of hrR3 into HT29 flank tumors significantly reduces tumor growth rate, and the administration of ganciclovir has no additive effect. CONCLUSIONS: The inherent cytotoxicity of hrR3 replication effectively destroys colon carcinoma cells in vitro and in vivo. This cytotoxicity is not enhanced in vivo by the addition of ganciclovir. In the future, more efficacious and selective HSV 1 vectors may be useful in the treatment of cancer.     

Limited efficacy of gene transfer in herpes simplex virus-thymidine kinase/ganciclovir gene therapy for brain tumors

OBJECT: Low efficacy of gene transfer, transient gene expression, and toxicity of viral vectors are the major hurdles in successful anticancer gene therapy. The authors conducted in vitro (U87MG cell line) and in vivo (xenograft, tumor-bearing rodent model) studies to address the stability of transduction by using the adenoassociated virus serotype-2 (AAV2)-thymidine kinase (TK) vector over time. METHODS: Standard methods for cell growth and a ganciclovir (GCV) cytotoxicity assay were applied. The AAV2-TK was infused into implanted tumors in athymic rats via convection-enhanced delivery (CED). Thymidine kinase expression was evaluated through immunohistochemical analysis, and the distribution volumes of the transduced tumors were calculated. Twenty-four hours following the viral infusions, animals were treated with GCV (50 mg/kg intraperitoneally every day for 10 days; six rats) or phosphate-buffered saline (six rats). A rapid decrease in TK expression over time was observed both in vitro and in vivo. A large volume of the tumor (up to 39%) was transduced with AAV2-TK following CED. Administration of GCV resulted in limited therapeutic effects (survival of 25.8 compared with 21.3 days). CONCLUSIONS: Rapid elimination of TK expression from dividing tumor cells and focal transduction of the brain tumor were most likely responsible for the limited bystander effect in this approach. Immediate administration of GCV is crucial to assure maximal efficacy in the elimination of cancer cells. In addition, the complete or diffused transduction of a brain tumor with TK may be required for its total eradication.     

Possibility and future problems of gene therapy for gastric cancer]

Recently, stage-oriented surgery has been performed for gastric cancer, but a new strategy is necessary for stage IV gastric cancer. The first target of gene therapy for gastric cancer was for stage IV patients with-widespread lymph node metastases and/or peritoneal dissemination. We reported on suicide gene therapy in experimental gastric cancer induced by ENNG in the dog, and the results showed that in situ gene transfer of a suicide gene (Ad. CAGHSV-TK) followed by prodrug (GCV) treatment may be applicable not only to the primary gastric tumor, but also to lymph node metastasis. Next, we assessed the efficacy of in situ gene therapy with Ad. CAGHSV-TK/GCV in gastric cancer induced by MNNG in rats, and followed the histopathological changes in the gastric cancer and HSV-TK gene in peripheral blood for 30 days. The results showed that: 1) apoptosis preceded tissue degeneration; 2) histopathological efficacy requires 30 days after suicide gene therapy; and 3) the HSV-TK gene persisted for 30 days. Based on these studies, we speculated that combination treatment with endoscopy is possible for all early gastric cancer, i.e., endoscopic mucosal resection of the primary tumor plus suicide gene therapy for sentinel lymph node metastasis. New possible strategies for peritoneal dissemination are: 1) tumor dormancy therapy with adeno-associated virus (AAV); and 2) combination gene therapy with suicide genes plus gene transfer to provide immunotherapy.     

Adenoviral herpes simplex virus thymidine kinase gene therapy in an orthotopic lung cancer model

Background. Although adenovirus-mediated herpes simplex virus thymidine kinase (HSVtk) gene therapy is a potential candidate for a novel effective therapy for lung cancer, previous studies have been performed only in a subcutaneous tumor model employing nude mice. We studied therapeutic potentials in correlation with accurate adenoviral gene transduction efficiency in a more clinically relevant orthotopic lung cancer model employing imunocompetent mice.

Methods. To analyze the cytotoxicity of adenoviral HSVtk gene transduction and ganciclovir, a cell proliferation assay was performed in vitro. A survival study was carried out in immunocompetent mice with orthotopic lung cancer, which was generated by intrapulmonary inoculation with syngeneic murine lung cancer cells that had been infected beforehand with each adenoviral vector at the predetermined gene transduction efficiencies.

Results. Tumor cells were efficiently killed by infection with adenovirus carrying the HSVtk gene with the addition of ganciclovir in vitro. In the in vivo experiment all control mice died of rapid growth of the primary lung cancer and of metastases to mediastinal lymph nodes within 26 days after tumor inoculation. In contrast 50% and 100% of mice survived more than 40 days after inoculation with adenovirally HSVtk-transfected tumor cells that moderately and highly expressed HSVtk, respectively, when followed by ganciclovir administration. Gene transduction efficiencies were 67%.

Conclusions. Adenovirus-mediated HSVtk gene therapy may be therapeutic for lung cancer when gene transduction efficiencies and sufficient expression levels of HSVtk can be achieved. Moreover, the present findings underscore the importance of the mouse orthotopic lung cancer model for studies of gene therapy.     

Immunomodulation of glioma cells after gene therapy: induction of major histocompatibility complex class I but not class II antigen in vitro

OBJECTIVE: Acquired immunity has been demonstrated in Fischer rats bearing syngeneic 9L tumors after herpes simplex virus (HSV) thymidine kinase (TK) gene transfection and ganciclovir treatment. The nature of this immunity in rats and its relevance to the HSV TK/ganciclovir protocol for human subjects remain to be determined. In this study, levels of major histocompatibility complex (MHC) Class I and II antigen expression were measured before and after HSV TK transfection, in an effort to document immunomodulatory changes caused by gene therapy. METHODS: Tumor cells from the 9L gliosarcoma cell line, three primary human glioma cultures, and the human glioma cell line U87 MG were transduced with HSV TK vector-containing supernatant from fibroblast-producing cells (titer of 5 x 10(6) colony-forming units/ml) and selected in G418 medium for neomycin resistance. Clones were pooled or individually selected for cell-killing assays with ganciclovir, to confirm TK expression (10(3) cells/well in a 96-well dish). Northern analyses using MHC Class I and Class II complementary deoxyribonucleic acid probes were performed on blots containing total ribonucleic acid from wild-type tumor cells and HSV TK transfectants. A beta-actin complementary deoxyribonucleic acid probe served as an internal control. Cell surface expression was confirmed with flow cytometry. The induction of MHC Class I was tested for cycloheximide and genistein sensitivity. RESULTS: All cell cultures exhibited increases in MHC Class I but not MHC Class II expression, as determined by Northern analysis densitometry and flow cytometry. Cycloheximide treatment did not diminish the up-regulation of MHC Class I after retroviral transfection, implicating a signal transduction pathway that does not require ongoing protein synthesis. Genistein pretreatment of cell cultures did diminish the up-regulation of MHC Class I, implicating a tyrosine kinase in the signaling cascade. CONCLUSION: Induction of MHC Class I in rat and human glioma cells after HSV TK retroviral gene therapy is a primary effect that is dependent on tyrosine kinase activity. Specific immune responses generated after transfection may represent an important general side effect of gene therapy protocols. Elucidation of the mechanism of immunomodulation after gene therapy will likely yield safer and more effective clinical protocols.     

Characterization of human T lymphocytes engineered to express interleukin-15 and herpes simplex virus-thymidine kinase

Introduction

Preclinical studies have demonstrated that tumor-reactive T cells expressing the interleukin (IL)-15 transgene had enhanced activity. Gene therapy strategies using IL-15 should include a safety mechanism in anticipation of possible adverse effects because IL-15 overexpression has been implicated in autoimmune disorders and may be involved in the pathogenesis of some leukemias. We developed a retroviral vector carrying both IL-15 and the herpes simplex virus-thymidine kinase (HSV-TK) suicide gene and characterized its application in the transduction of human T lymphocytes.

Methods

A retroviral vector carrying IL-15 and HSV-TK genes was optimized for the transduction of human T lymphocytes. IL-15 production was measured by enzyme-linked immunosorbent assay. Thymidine incorporation and cell viability assays were used to assess the efficacy of the HSV-TK suicide gene. Genetically modified tumor-infiltrating lymphocytes (TILs) were assayed for survival after withdrawal from exogenous IL-2. The activity and specificity of retrovirally transduced TILs were assessed using tumor coculture assays.

Results

Human T cells transduced with the IL-15 HSV-TK vector exhibited thymidine uptake in the absence of exogenous cytokine support and survived in culture for up to 80 d without IL-2. IL-15 HSV-TK–transduced T cells were efficiently killed by ganciclovir at concentrations as low as 0.1 μM. TILs transduced with the IL-15 HSV-TK vector retained specific recognition of HLA-A2+, MART1+ melanomas, even after withdrawal of IL-2.

Conclusions

Human T lymphocytes genetically modified with the IL-15 HSV-TK retroviral vector retained the ability to recognize tumor antigen while gaining the ability to secrete IL-15 and prolong their own survival. IL-15 HSV-TK–transduced T cells expressed HSV-TK and could be efficiently eliminated by ganciclovir.     

TK基因/9-丙氧鸟苷联合mGM-CSF基因治疗胃癌

目的 观察自杀基因ＴＫ对小鼠胃癌的杀伤作用,并联合ｍＧＭ－ＣＳＦ基因,观察免疫反应在增强ＴＫ杀伤性中的作用。方法 应用逆转录病毒方法转导自杀基因ＴＫ,应用脂质体方法转导细胞因子基因ｍＧＭ－ＣＳＦ。观察ＴＫ基因体外对小鼠胃癌６１５小鼠前胃癌（ＭＦＣ）细胞的杀伤性和旁观者效应;体内实验中将病毒上清注入瘤体内,并结合应用其前药９－丙氧鸟苷（ＧＣＶ）和ｍＧＭ－ＣＳＦ基因,分别观察肿瘤的生长情况。通过病理切     

Surgical treatment of primary lung cancer with synchronous brain metastases

OBJECTIVES: The role of surgical resection for brain metastases from non-small cell lung cancer is evolving. Although resection of primary lung cancer and metachronous brain metastases is superior to other treatment modalities in prolonging survival and disease-free interval, resection of the primary non-small cell lung cancer and synchronous brain metastases is controversial. METHODS: From January 1975 to December 1997, 220 patients underwent surgical treatment for brain metastases from non-small cell lung cancer at our institution. Twenty-eight (12.7%) of these patients underwent surgical resection of synchronous brain metastases and the primary non-small cell lung cancer. RESULTS: The group comprised 18 men and 10 women. Median age was 57 years (range 35-71 years). Twenty-two (78.6%) patients had neurologic symptoms. Craniotomy was performed first in all 28 patients. Median time between craniotomy and thoracotomy was 14 days (range 4-840 days). Pneumonectomy was performed in 4 patients, bilobectomy in 4, lobectomy in 18, and wedge excision in 2. Postoperative complications developed in 6 (21.4%) patients. Cell type was adenocarcinoma in 11 patients, squamous cell carcinoma in 9, and large cell carcinoma in 8. After pulmonary resection, 17 patients had no evidence of lymph node metastases (N0), 5 had hilar metastases (N1), and 6 had mediastinal metastases (N2). Twenty-four (85.7%) patients received postoperative adjuvant therapy. Follow-up was complete in all patients for a median of 24 months (range 2-104 months). Median survival was 24 months (range 2-104). Survival at 1, 2, and 5 years was 64.3%, 54.0%, and 21.4%, respectively. The presence of thoracic lymph node metastases (N1 or N2) significantly affected 5-year survival (P =.001). CONCLUSION: Although the overall survival for patients who have brain metastases from non-small cell lung cancer is poor, surgical resection may prove beneficial in a select group of patients with synchronous brain metastases and lung cancer without lymph node metastases.     

自杀基因联合全反式维甲酸治疗对前列腺癌PC-3细胞旁观者效应的影响

目的 观察单纯疱疹病毒胸苷激酶(HSV-TK)/丙氧鸟苷(GCV)系统联合全反式维甲酸(ATRA)对人雄激素非依赖性前列腺癌PC-3细胞旁观者效应的影响.方法 噻唑蓝(MTT)比色法检测HSV-TK(Ad-TK)/GCV系统对PC-3细胞的杀伤力.流式细胞仪检查连接蛋白(Cx)43阳性细胞数.结果 单纯Ad-TK/GCV系统对PC-3细胞旁观者效应在TK+:TK-细胞混合比例为5:5时明显出现(P<0.05),而联合ATRA后,在TK+:TK-细胞混合比例为3:7时就明显出现(P<0.05).Ad-TK/GCV联合ATRA处理PC-3细胞后,在细胞抑制率均达到约50%时,其TK+PC-3细胞混合比例可降低20%.ATRA(10-6 moL/L)处理PC-3细胞1、3、5 d后,Cx43阳性细胞率由10.5%分别升高为25.8%、50.8%和62.4%(P<0.01).结论 ATRA可能通过增强基于Cx43的旁观者效应,从而提高Ad-TK/GCV系统对前列腺癌的杀伤效应.