Virally directed fluorescent imaging improves diagnostic sensitivity in the detection of minimal residual disease after potentially curative cytoreductive surgery

Completeness of cytoreduction is an independent prognostic factor after cure-intended surgery for peritoneal carcinomatosis. NV1066, a genetically engineered herpes simplex virus carrying the transgene for green fluorescent protein, selectively infects cancer cells. We sought to determine the feasibility of virally directed fluorescent imaging in the intraoperative detection of minimal residual disease after cytoreductive surgery. NV1066 infected human gastric cancer cells, OCUM-2MD3, and mesothelioma JMN cells at all doses. The infected cells expressed green fluorescent protein and were killed. OCUM-2MD3, and mesothelioma JMN cells at all doses. Peritoneal carcinomatosis was established in mice by injection of OCUM cells into the peritoneal cavity. Forty-eight hours after intraperitoneal injection of NV1066, two experienced surgeons resected all visible disease and identified mice free of disease. Eight of 13 mice thought to be free of disease were found to have residual disease as identified by green fluorescence (mean number of observations: 5; range: 1–9). Residual disease was most frequently observed in the retroperitoneum, pelvis, peritoneal surface, and liver. Specificity of NV1066 infection to tumor nodules was confirmed by immunohistochemistry and by polymerase chain reaction for viral gene. Virally directed fluorescent imaging, a novel molecular imaging technology, can be used for real-time visualization of minimal residual disease after cytoreductive surgery and can improve the completeness of cure-intended resection. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation) Supported in part by AstraZeneca Cancer Research and Prevention fellowship (P.S.A), training grant T 32 CA09501 (D.P.E and K.J.H.), grants RO1 CA 76416 and RO1 CA/DK80982 (Y.F.) from the National Institutes of Health, grant BC024118 from the U.S. Army (Y.F.), grant IMG0402501 from the Susan G. Komen Foundation (Y.F. and P.S.A), and grant 032047 from the Flight Attendant Medical Research Institute (Y.F. and P.S.A).     

Employing Tumor Hypoxia for Oncolytic Therapy in Breast Cancer

Hypoxia is a common tumor condition associated with metastases, therapeutic resistance, and poor patient survival. Forty percent of breast cancers are hypoxic, with a median oxygen concentration of 3.9%, and a third of tumors have regions less than 0.3%. Normal breast tissue is reported to have oxygen concentrations greater than 9%. This tumor hypoxia in breast cancer confers resistance to conventional radiation therapy and chemotherapy, as well as making estrogen-receptor-positive tumors less sensitive to hormonal therapy. Novel treatment modalities are needed to target hypoxic tumor cells. Lower tumor oxygen levels compared with surrounding normal tissues may be utilized to target and enhance herpes oncolytic viral therapy in breast cancer. Attenuated oncolytic herpes simplex viruses offer a unique cancer treatment by specifically infecting, replicating within, and lysing tumor cells. They carry genetically engineered mutations to reduce their virulence and attenuate their ability to infect normal tissues. Studies have shown the safety and efficacy of oncolytic herpes simplex viruses in treating breast cancer both in humans and in preclinical models. The placement of essential viral genes under the control of a hypoxia-responsive enhancer, which is upregulated selectively in hypoxic tissue, represents a promising strategy to target oncolytic viruses precisely to hypoxic cancer cells. In this review we describe strategies to harness hypoxia as a trigger for oncolytic viral gene expression in breast cancer, thereby increasing the specificity of viral infection, replication, and cytotoxicity to hypoxic areas of tumor. Such a targeted approach will increase efficacy in the therapy of hypoxic tumors while achieving a reduction in total dose of viral therapy.Supported in part by AACR-Astra Zeneca Cancer Research and Prevention Foundation Fellowship (P.S.A), grants RO1 CA 75416 and RO1 CA/DK80982 (Y.F.) from the National Institutes of Health, grant MBC-99366 (Y.F.) from the American Cancer Society, grant BC024118 from the US Army (Y.F.), grant IMG0402501 from the Susan G. Komen Breast Cancer Foundation (Y.F. and P.S.A.) and grant 032047 from Flight Attendant Medical Research Institute (Y.F. and P.S.A.)     

The replication-competent oncolytic herpes simplex mutant virus NV1066 is effective in the treatment of esophageal cancer

BACKGROUND: The oncolytic herpes simplex-1 virus, NV1066, is a replication-competent virus that has been engineered to infect and lyse tumor cells selectively and to carry a transgene for enhanced green fluorescent protein (EGFP). The purpose of this study was to determine viral cytotoxicity in an esophageal cancer cell line and to determine whether EGFP expression could be used as a marker of viral infection. METHODS: BE3 esophageal adenocarcinoma cells were infected with NV1066 in vitro to determine cell kill and viral replication. EGFP expression was assessed by flow cytometry. The in vivo anti-tumor activity of NV1066 was tested in subcutaneous and intraperitoneal xenograft models. EGFP expression was localized in vivo by fluorescent microscopy and fluorescent laparoscopy. RESULTS: NV1066 effectively replicated within and killed BE3 cells in vitro and in vivo. EGFP expression identified infected tumor cells. After NV1066 treatment in vivo, EGFP expression localized to the tumor. In an intraperitoneal tumor model, EGFP could be visualized endoscopically using a laparoscope with a fluorescent filter. CONCLUSIONS: NV1066 has oncolytic activity against the BE3 cell line and may be a useful therapy against esophageal cancer. EGFP expression localizes the virus and may help to identify tumor deposits in vivo. Oncolytic activity with NV1066 against gastrointestinal cancers may potentially be tracked by endoscopy.     

Herpes simplex virus based gene therapy enhances the efficacy of mitomycin C for the treatment of human bladder transitional cell carcinoma

PURPOSE: Oncolytic replication competent herpes simplex virus type-1 (HSV) mutants have the ability to replicate in and kill malignant cells. We have previously reported the ability of replication competent HSV to control bladder cancer growth in an orthotopic murine model. We hypothesized that the combination of a chemotherapeutic agent used for intravesical treatment, namely mitomycin C (MMC) (Bristol-Myers Squibb Oncology, Princeton, New Jersey), and oncolytic HSV would exert a synergistic effect for the treatment of human transitional cell carcinoma. MATERIALS AND METHODS: We used mutant HSV NV1066 (Medigene, San Diego, California), which is deleted for viral genes ICP0 and ICP4, and selectively infects cancer cells, to treat the transitional cell carcinoma lines KU19-19 and SKUB. Cell survival was determined by lactate dehydrogenase assay for each agent as well as for drug-viral combinations from days 1 to 5. The isobologram method and the combination index method of Chou-Talalay were used to assess the synergistic effect. RESULTS: NV1066 enhanced MMC mediated cytotoxicity at all combinations tested for KU19-19 and SKUB. The combination of the 2 agents demonstrated a synergistic effect and allowed dose reduction by 12 and 10.4 times (NV1066), and by 3 and 156 times (MMC) for the treatment of KU19-19 and SKUB, respectively, while achieving an estimated 90% cell kill. CONCLUSIONS: These data provide the cellular basis for the clinical investigation of combined MMC and oncolytic HSV therapy for the treatment of bladder cancer.     

Effective treatment of pancreatic tumors with two multimutated herpes simplex oncolytic viruses

Pancreatic cancer is an aggressive, rapidly fatal disease against which current nonsurgical therapy has minimal impact. This study evaluates the efficacy of two novel, replication-competent, multimutated herpes viruses (G207 and NV1020) in an experimental model of pancreatic cancer. Four human pancreatic carcinoma cell lines were exposed to G207 or NV1020, and cell survival and viral progeny production were determined. Flank tumors in athymic mice were subjected to single or multiple injections of 1 X 10⁷ G207 or NV1020, and tumor volume was evaluated over time. For all of the cell lines, G207 and NV1020 produced infection, viral replication, and cell lysis (P <0.05). NV1020 resulted in a higher production of viral progeny compared to G207. The efficacy of viral tumor cell kill was greatest in those cells with the shortest in vitro doubling time. For flank tumors derived from hs766t, single or multiple injections of both viruses were equally effective and significantly reduced flank tumor burden (P <0.05). Complete hs766t flank tumor eradication was achieved in 25% (5 of 20) of animals treated with G207 and 40% (8 of 20) of animals treated with NV1020. In vivo efficacy correlated with in vivo tumor doubling time. There were no adverse effects related to viral administration observed in any animal. NV1020 and G2O7 effectively infect and kill human pancreatic cancer cells in vitro and in vivo. Given the lack of effective nonoperative treatments for pancreatic cancer, oncolytic herpes viruses should be considered for clinical evaluation. Presented in part at the Forty-First Annual Meeting of The Society for Surgery of the Alimentary Tract, San Diego, Calif., May 21–24, 2000.     

Oncolytic herpes viral therapy is effective in the treatment of hepatocellular carcinoma cell lines

The rising incidence of hepatocellular carcinoma (HCC) in western countries, along with the poor prognosis offered by present-day treatment modalities, makes novel therapies for this disease necessary. Oncolytic herpes simplex viruses (HSV) are replication-competent viruses that are highly effective in the treatment of a wide variety of experimental models of human malignancies. This study seeks to investigate the effectiveness of oncolytic herpes viruses in the treatment of primary HCC cell lines. Sixteen commercially available human HCC cell lines were studied. G207 is an attenuated, replication-competent, oncolytic HSV engineered to selectively replicate within cancer cells. Cell lines were tested for viral sensitivity to G207 and their ability to support viral replication using standard cytotoxicity and viral replication assays. Eleven of 16 cell lines were moderately to highly sensitive to G207 viral oncolysis. HCC cell lines additionally demonstrated the ability to support viral replication in vitro with as high as 800-fold amplification of the administered viral dose observed. G207 is cytotoxic to, and efficiently replicates within, HCC cell lines in vitro. From these data, we suggest that oncolytic HSV therapy may have a role in the treatment of HCC, and in vivo studies are warranted. Presented in part at the 2005 American Hepato-Pancreato-Biliary Association Congress, Hollywood, Florida, April 14–17, 2005. Supported by grants R01CA75461 and R01CA72632 from the National Institutes of Health, and by grant MBC-99366 from the American Cancer Society (Yuman Fong).     

胰腺癌细胞对5氟脲嘧啶和健择的获得性耐药机制的研究

目的探讨胰腺癌细胞对 5氟脲嘧啶 (5 FU)和健择产生获得性耐药的机制。方法用磺酰罗丹明B蛋白染色法检测细胞毒性作用 ,根据药物剂量与细胞生存的关系计算 5 0 %抑制浓度(IC50 ) ;用RNA酶保护分析和Westernblot法来检测Bcl xL和mcl 1的表达水平。结果 5 FU和健择对 3株胰腺癌细胞均产生了细胞毒性作用。 5 FU长期作用后 ,Capan 1细胞IC50 上升了 2 1倍 (P <0 0 5 ) ;健择长期作用后 ,Capan 1细胞IC50 上升了 1 8倍 (P <0 0 5 ) ;而Mia Paca 2细胞在 5 FU和健择作用前后IC50 明显降低 (P <0 0 5 )。产生获得性耐药细胞的Bcl xL 和mcl 1的表达均上调。结论胰腺癌细胞对 5 FU相对耐药 ,而对健择较为敏感。化疗药物长期作用后 ,抑凋亡基因Bcl xL和mcl 1的表达上调 ,胰腺癌细胞产生了获得性耐药。     

Interleukin 12 secretion enhances antitumor efficacy of oncolytic herpes simplex viral therapy for colorectal cancer

OBJECTIVE: To assess the strategy of combining oncolytic herpes simplex virus (HSV) therapy with immunomodulatory therapy as treatment for experimental colon cancer. The oncolytic HSV recombinant NV1023 and the interleukin 12 (IL-12)-secreting oncolytic NV1042 virus were evaluated in vitro and in vivo with respect to antitumor efficacy. SUMMARY BACKGROUND DATA: Genetically engineered, replication-conditional, attenuated HSVs have shown oncolytic activity against a wide variety of solid malignancies. Other strategies for treating cancer have involved immunomodulation and cytokine gene transfer using viral vectors. This study has combined both of these strategies by inserting the murine IL-12 gene into a replication-competent HSV. This approach allows oncolytic therapy to replicate selectively within and lyse tumor cells while providing the host immune system with the cytokine stimulus necessary to recruit and activate inflammatory cells needed to enhance the antitumor effect. METHODS: NV1023 is a multimutant HSV based on the wild-type HSV-1 F strain. NV1042 was created by insertion of the mIL-12 gene into NV1023. Cytotoxicity and viral proliferation of both NV1023 and NV1042 within murine CT26 colorectal cancer cells were first shown. Cells infected with NV1042 were then shown to produce significant levels of IL-12. Using an experimental flank model of colon cancer, mice were treated with both high and low doses of NV1023 or NV1042 and were followed up for both cure and reduction in tumor burden. RESULTS: Both viruses could replicate within and kill CT26 cells in vitro, with 100% cytotoxicity achieved after infection by either virus. Only NV1042 could produce mIL-12. Therapy using high viral doses to treat animals in vivo showed equal efficacy between NV1023 and NV1042, with five of seven cures for each virus. When viral doses were lowered, only the cytokine-producing NV1042 virus could reduce tumor burden and cure animals of their disease. CONCLUSIONS: Both NV1023 and NV1042 have the oncolytic potential to kill colon cancer cells at higher doses. Cytokine production by NV1042 may allow lower doses of viral therapy to be used without losing antitumor efficacy. The combination of oncolytic viral therapy and immunomodulatory strategies should be further investigated as treatment for colon cancer.     

Virally-directed fluorescent imaging (VFI) can facilitate endoscopic staging

Background Replication-competent, tumor specific herpes simplex virus NV1066 expresses green fluorescent protein (GFP) in infected cancer cells. We sought to determine the feasibility of GFP-guided imaging technology in the intraoperative detection of small tumor nodules. Methods Human cancer cell lines were infected with NV1066 at multiplicities of infection of 0.01, 0.1 and 1. Cancer cell specific infectivity, vector spread and GFP signal intensity were measured by flow cytometry and time-lapse digital imaging (in vitro); and by use of a stereomicroscope and endoscope equipped with a fluorescent filter (in vivo). Results NV1066 infected all cancer cell lines and expressed GFP at all MOIs. GFP signal was significantly higher than the autofluorescence of normal cells. One single dose of NV1066 spread within and across body cavities and selectively infected tumor nodules sparing normal tissue. Tumor nodules undetectable by conventional thoracoscopy and laparoscopy were identified by GFP fluorescence. Conclusion Virally-directed fluorescent imaging (VFI) is a real-time novel molecular imaging technology that has the potential to enhance the intraoperative detection of endoluminal or endocavitary tumor nodules. R. Huq: Molecular Cytology Core Facility Presented at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) meeting, Fort Lauderdale, FL, USA, 13–16 April 2005     

Interferon receptors and the caspase cascade regulate the antitumor effects of interferons on human pancreatic cancer cell lines

BACKGROUND: Interferons (IFNs) have antiproliferative effects on tumor cells. The apoptotic effects and sensitization to chemotherapy conferred by IFN therapy, however, are not clearly understood. The aims of the present study were to explore the apoptotic effects of IFNs in human pancreatic cancer cell lines and to attempt to define their ability to synergistically enhance sensitivity to 5-fluorouracil (5-FU) and gemcitabine, a mechanism that depends on the expression of IFN receptors. METHODS: Human pancreatic cancer cells were cultured alone or in combination with the chemotherapeutic agents 5-FU and gemcitabine. Differential dosages of IFN-alpha, -beta, and -gamma were also added to the cell lines concomitantly during a period of 24 to 96 hours. The cell line viability and effects of treatment were examined using the methylthiazol tetrazolium assay and single-stranded DNA apoptosis assay. The expression of IFN receptors was determined using immunohistochemistry. Caspase-8 inhibitor was used to block the caspase cascade. RESULTS: The antiproliferative and apoptotic effects of IFNs were most profoundly demonstrated on those cells that expressed the respective IFN receptor. The apoptotic effects provided by the interferons, however, were blocked by caspase-8 inhibition. The addition of IFNs significantly enhanced the cytotoxic effects of 5-FU and gemcitabine in those cell lines that expressed the corresponding IFN-alpha, -beta, or -gamma receptors. CONCLUSIONS: This study on pancreatic cancer cell lines has demonstrated that IFNs mediate apoptosis through IFN receptors and the caspase cascade. Enhanced cytotoxicity occurred when IFNs were combined with 5-FU and gemcitabine.     

胰腺癌细胞对5-氟尿嘧啶和健择产生获得性耐药的分子生物学机制初探

目的　探索胰腺癌细胞对 5 氟尿嘧啶 ( 5 FU)和健择产生获得性耐药的机制 ,分析这种耐药与凋亡的调控基因———bcl 2家族之间的关系。方法　 5 FU和健择的细胞毒性作用通过磺酰罗丹明B蛋白染色法 (SRB)来检测 ,应用RNA酶保护分析法来检测化疗药物作用前后bcl 2家族mRNA表达水平。结果　 5 FU和健择对 3株胰腺癌细胞均产生了细胞毒性作用 ,5 FU长期作用后 ,Capan 1细胞 5 0 %抑制浓度 (IC50 )上升了 2 .1倍 (P <0 .0 5 )。健择长期作用后 ,Capan 1细胞IC50 上升了 1.8倍 (P <0 .0 5 )。RNA酶保护分析结果提示 ,bcl xL 和mcl 1上调的细胞产生了获得性耐药。结论　化疗药物长期作用后 ,抑凋亡基因bcl xL 和mcl 1上调 ,胰腺癌细胞产生了获得性耐药。阻断这些抑凋亡基因的表达可能提高胰腺癌细胞对 5 FU和健择的敏感性 ,从而产生治疗作用。     

A structurally optimized celecoxib derivative inhibits human pancreatic cancer cell growth

Deregulation of the phosphatidylinositol 3-kinase (PI-3K)/PDK-l/Akt signaling cascade is associated with pancreatic cancer tumor invasion, angiogenesis, and tumor progression. As such, it has been postulated that PDK-1/Akt signaling inhibitors may hold promise as novel therapeutic agents for pancreatic cancer. Disadvantages of currently available Akt inhibitors include tumor resistance, poor specificity, potential toxicity, and poor bioavailability. Previous studies have demonstrated that OSU-03012, a celecoxib derivative, specifically inhibits PDK-1 mediated phosphorylation of Akt with IC₅₀ values in the low mM range. Human pancreatic cancer cell lines AsPC-1, BxPC-3, Mia-PaCa 2, and PANC-1 were cultured in media containing varying concentrations of OSU-03012, 5-fluorouracil (5-FU), and gemcitabine, and changes in Akt phosphorylation and cell viability were evaluated using western blotting and a 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Treatment with OSU-03012 resulted in decreased PDK-1-mediated Akt phosphorylation and cell growth inhibition for all cell lines with IC₅₀ values ranging between 1.0 and 2.5 μM. Resistance to 5-FU and gemcitabine was observed in cell lines AsPC-1 and BxPC-3. Further analyses indicate that OSU-03012 induces both proapoptotic and antiproliferative effects in these cells. Taken together, these data suggest that OSU-03012 has potential value as a novel therapy for pancreatic cancer. Presented at the 2005 American Hepato-Pancreato-Biliary Association Congress, Hollywood Florida, April 14–17, 2005.     

利用鼠尾胶原建立胶原微滴药物敏感性检测方法

目的 利用鼠尾胶原建立胶原凝胶微滴肿瘤药物敏感性检测(CD-DST)技术,探讨其在胰腺瘤等恶性肿瘤化疗敏感性检测中的应用.方法 利用鼠尾胶原建立CD-DST检测方法 ,对3株胰腺癌细胞株、15例胰腺癌和10例胃肠道恶性肿瘤的手术切除标本进行临床化疗药物敏感性检测.结果 利用鼠尾胶原建立的CD-DST能有效的对胰腺癌细胞株和临床肿瘤标本进行体外肿瘤药物敏感性检测,对临床肿瘤标本的整体检测成功率为80%(20/25),胰腺癌细胞在体外对5-氟尿嘧啶、吉西他滨、奥沙利铂的化疗敏感性低于胃肠道恶性肿瘤.结论 CD-DST是一种切实可行的体外肿瘤化疗药物敏感性检测方法 ,可用于临床制定个体化化疗方案.     

耐药胰腺癌细胞株对放射敏感性影响的初步探讨

目的初步探讨耐药胰腺癌细胞株的耐药性对其放射敏感性的影响。方法选取人胰腺癌细胞株SW1990经氟尿嘧啶（5-FU）、阿霉素和吉西他滨诱导后建立三株耐药细胞亚株（SW1990／FIL1、SW1990／ADM、SW1990／GZ）,通过流式细胞仪及直线加速器照射后进行细胞周期及放射生物学相关参数检测。结果细胞周期分析显示,与亲本株SW1990相比,SW1990／FU与SW1990／Gz的Go／G。期比例增高,G2／M期比例明显降低;SW1990／ADM各细胞周期百分比变化不大。集落实验结果表明,与亲本株SW1990相比,SW1990／FU及SW1990／GZ的存活分数（sir2）分别升高26．9％（P＜0．01）和14．4％（P＜0．01）,差异有统计学意义;SW1990／ADM的sir2升高1．1％,差异不明显。结论耐药胰腺癌细胞株的耐药性对其放射敏感性具有一定影响,胰腺癌耐药细胞株放射敏感周期G2／M期比例降低,从而导致其放射敏感性降低,耐放射性增加。     

Effects of the proteasome inhibitor bortezomib on gene expression profiles of pancreatic cancer cells

BACKGROUND: Pancreatic cancer remains a highly chemoresistant malignancy. Gemcitabine is a widely used clinical chemotherapeutic agent against locally advanced and metastatic pancreatic cancer. Proteasome inhibitor bortezomib has been shown to result in enhanced cytotoxicity and apoptosis when used alone or in combination with gemcitabine in pancreatic cancer cell lines. MATERIALS AND METHODS: To determine the effect of bortezomib on gene expression profile of pancreatic adenocarcinoma cells with different sensitivity to gemcitabine, we used Affymetrix HG U133A 2.0 GeneChip (Santa Clara, CA) and measured changes induced by bortezomib in pancreatic cancer cell lines with high (BxPC-3) and low (PANC-1) sensitivity to gemcitabine, at time points 24 h. Selected genes were subsequently validated by quantitative real-time polymerase chain reaction. RESULTS: Forty-four common genes in both PANC-1 and BxPC-3 cells were identified as up-regulated (>3-fold) induced by bortezomib analyzed by microarray, which are associated with multiple cytotoxic and cytoprotective effects. Bcl-2 was repressed by bortezomib in both PANC-1 and BxPC-3 cells, while no changes induced in either cell by bortezomib were disclosed in all five members of nuclear factor-kappa B family. Other interesting genes related to apoptosis or drug metabolism, such as TP53 and ABCB1 (mdr1), were not found differentially expressed in common. CONCLUSIONS: Bortezomib exhibits antitumor effects toward pancreatic cancer in vitro and in vivo. Genes with divergent apoptotic effects are induced by bortezomib, which may become promising targets for pancreatic cancer treatment.     

Use of an oncolytic virus secreting GM-CSF as combined oncolytic and immunotherapy for treatment of colorectal and hepatic adenocarcinomas

BACKGROUND: Oncolytic cancer therapy using herpes simplex viruses (HSV) that have direct tumoricidal effects and cancer immunotherapy using the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) have each been effective in preclinical testing. NV1034 is a multimutated oncolytic HSV carrying the gene for murine GM-CSF that attempts to combine these 2 anticancer strategies. The purpose of this study was to compare NV1034 to NV1023, the parent HSV mutants lacking GM-CSF, to determine if such combined oncolytic and immunotherapy using a single vector has advantages over oncolytic therapy alone. METHODS: Expression GM-CSF in vitro did not alter the infectivity, cytotoxicity, or replication of NV1034 compared to the noncytokine-secreting control. Tumors infected with NV1034 produced GM-CSF in picogram quantities. In vivo efficacy of the viruses against murine colorectal carcinoma CT26 and murine hepatoma Hepa l-6 was then tested in subcutaneous tumors in syngeneic Balb/c and C57 L/J mice, respectively. In these immune-competent models, NV1034 and NV1023 each demonstrated potent antitumor activity. RESULTS: Treatment with NV1034 had significantly better antitumor effect compared to treatment with NV1023. Furthermore, there was no difference in the antitumor efficacy of these viruses in mice depleted of CD4+ and CD8+ T lymphocytes. CONCLUSIONS: Viral vectors combining oncolytic and immunotherapy are promising agents in treatment of colorectal carcinoma and hepatoma.     

Chirurgische Therapie des lokal fortgeschrittenen und primär inoperablen Pankreaskarzinoms nach neoadjuvanter präoperativer Radiochemotherapie

INTRODUCTION: So far, surgery represents the only prospect for cure in patients with pancreatic cancer. Most patients, however, present with locally advanced pancreatic cancer at primary diagnosis. Recently, novel therapeutic regimens with preoperative radiochemotherapy have been developed that may improve long-term survival and resectability rates of patients with locally advanced pancreatic cancer. METHODS: This feasibility study evaluates the preliminary results of neoadjuvant therapy with gemcitabine and 5-fluorouracil (5-FU) or cisplatin. Twenty-six patients suffering from locally advanced pancreatic cancer were considered for preoperative radiochemotherapy. They received radiation (45 Gy) and chemotherapy with simultaneous or sequential gemcitabine and 5-FU (n = 15) or gemcitabine and cisplatin (n = 11) administration prior to surgical resection. RESULTS: Mean patient age was 62.4 +/- 2.6 years and 62% (n = 16) were male. The response rate was 69%, and 11 patients underwent curative surgical resection of the pancreatic cancer. Nine Whipple procedures and two complete pancreatectomies were carried out. In five patients a total of eight surgical complications were observed. Median overall survival was 9.8 months after primary cancer diagnosis (mean 12.0 +/- 1.2). During follow-up no local recurrent disease was detected. CONCLUSIONS: Our findings lead us to conclude that preoperative chemoradiation with 45 Gy, gemcitabine and 5-FU or cisplatin is a powerful therapeutic tool in patients with locally advanced non-resectable pancreatic cancer. Major resections, including vascular reconstructions, are nonetheless associated with increased mortality. Preoperative chemoradiation contributes to improved survival in patients with primary non-resectable pancreatic cancer.     

5-氟尿嘧啶缓释剂瘤内注射治疗胰腺癌的实验研究和临床研究

目的 观察5-氟尿嘧啶(5-Fu)缓释剂对荷胰腺癌裸鼠肿瘤细胞及胰腺癌患者血清肿瘤标记物和细胞免疫的影响。方法 (1)5-Fu缓释剂的体外释放实验和体外抑瘤实验：测定浸出液药物的浓度，计算释放量；检测其浸出液对人胰腺癌细胞株PC3的抑制作用：(2)将荷胰腺癌细胞株Pc3裸鼠60只，随机分成静脉对照组(A组)、5-Fu静注组(B组)、基质植入组(C组)、大剂量5-Fu缓释剂植入组(D组)和小剂量5-FU缓释利植入组(E组)：治疗前及治疗后l4d测肿瘤大小。治疗2周后观察肿瘤组织学变化：免疫组化法测定bcl-2和Bax的蛋白表达水平；TUNEL法检测凋亡指数(Al)。(3)手术探查不能切除之胰腺癌69例随机分成3组：将5-FU缓释剂瘤内植入治疗组(治疗组)、术后行5-FU静脉化疗组(化疗组)和对照组。分别于术前1d和术后第14天采血，测定各组血清中NK细胞，T细胞亚群和CEA，CA50，CA19-9，CA125，CA242血清肿瘤标记物水平。结果 (1)5mg 5-FU缓释剂第1天释放量最大，为0．85mg，第3天为0．45mg，其后在0．25mg水平维持稳定的缓慢释放；释放时间长达l4d以上。(2)5-Fu缓释剂第1天的浸出液对人胰腺癌细胞株PC-3的抑制率达60．27％，第3天为34．25％，以后稳定在25．00％左右。5-Fu缓释剂瘤内注射治疗组裸鼠移植瘤生长速度减慢，bcl-2基因表达明显低于其他各组，而Bax基因表达明显高于其他各组，肿瘤细胞的Al明显高于其他各组。D组和E组肿瘤组织中炎症反应和血管内膜增厚程度明显高于其他各组。术后治疗组CD4 ／CD8 和NK细胞水平高于化疗组，而血清中E述5种肿瘤标记物低于对照组和化疗组。结论 5-Fu缓释剂能在2周内在体外较稳定地持续释放，对人胰腺癌细胞株PC3有持续抑制作用。该剂瘤内注射可明显抑制荷胰腺癌瘤裸鼠瘤体的生长，其作用机制与药物在肿瘤组织中引起的炎症反应和血管内膜增厚等因素有关；并可能与诱导肿瘤细胞的凋亡有关。该剂植入患者胰腺癌实体内，能明显降低5种血清肿瘤标记物水平，同时对患者的细胞免疫功能影响较小，5-Fu缓释剂可望成为治疗不能切除之胰腺癌的较好的制剂。