Flt-3 ligand: a potent dendritic cell stimulator and novel antitumor agent

Dendritic cell (DC) vaccination has generated intense interest as a potential cancer therapy. However, the rate limiting step has been the generation of DCs. Flt-3 ligand (FL) is a growth factor that was first discovered by its ability to stimulate the proliferation of hematopoietic progenitor cells of both lymphoid and myeloid origin. The remarkable activity of FL to induce large numbers of dendritic cells both in vivo and in vitro soon captured the interest of numerous researchers. In this review, we examine the structure and function of the FL, its antitumor activity in animal models, and its potential as a novel cancer treatment.     

Combination of direct intratumoral administration of dendritic cells and irradiation induces strong systemic antitumor effect mediated by GRP94/gp96 against squamous cell carcinoma in mice

We tested a new therapeutic modality for head and neck and esophageal cancers, a combination of direct intratumoral (i.t.) administration of dendritic cells (DCs) and radiation therapy (RT) in mouse squamous cell carcinoma (SCC). We also evaluated the functions of gp96, which can enhance systemic antitumor activity, and the mechanism of the abscopal effect. Mouse SCC cells (1 x 10(5)), SCCVII, were inoculated into the left femur of C3H/He mice subcutaneously, and also similarly inoculated into chest subcutaneous tissue. Only the left femur tumor was exposed to 4 or 10 Gy of ionizing radiation, and then 1 x 10(6) DCs i.t. was injected only into the femur tumor. Following this procedure, tumor volumes of the femur and chest were measured. We evaluated whether gp96 could enhance the antitumor effect. With DCs i.t. and RT, tumor growth was markedly suppressed. Tumor growth of non-treated tumors were also suppressed, indicating that the combination therapy of DCs and RT evoked systemic antitumor activity. In vitro, the enhancement of gp96 expression was strongly detected by immunostaining after irradiation, DCs with gp96 induced strong cytotoxic activity in vitro, and tumor growth inhibition was observed by direct i.t. injection of gp96. A combination of DCs i.t. and RT can induce a strong antitumor effect not only against treated local tumor but also against non-treated distant tumor, indicating that this treatment can evoke a strong systemic antitumor effect. Gp96 is thought to be one of the target molecules to explain the abscopal effect.     

Local administration of IL-12-transfected dendritic cells induces antitumor immune responses to colon adenocarcinoma in the liver in mice

Colorectal cancer is one of the most common fatal malignancies in the United States, with an incidence second only to lung cancer. The liver is the most common site of colorectal metastases and frequently the only affected organ once the primary tumor has been surgically removed. The only potentially curative treatment for metastatic colorectal cancer in the liver is surgery, although most patients are not eligible for resection. We have therefore, evaluated the therapeutic efficacy of dendritic cells (DCs) engineered to express IL-12 in a liver metastasis model. Direct administration of DCs into the portal vein significantly inhibited the growth of established MC38 colon carcinoma in the liver in C57BL/6 mice. This effect was accompanied by an intratumoral accumulation of CD4+, CD8+, and NLDC-145+ immune effector cells, and also resulted in a systemic immune response as determined by enhanced production of IFN-gamma by T lymphocytes isolated from both spleen and draining lymph nodes. Evaluation of homing of Cy3-labeled DCs following the portal vein injection confirmed their distribution in the liver and lymphoid tissue. Thus, a local delivery of DCs transduced with the IL-12 gene can not only inhibit colorectal tumor growth in vivo but also mount systemic antitumor immune responses. This approach is likely to improve the outcome of immunotherapy for metastatic colorectal cancer since high numbers of tumor-associated DCs positively correlate with a more favorable prognosis. Simultaneous local gene therapy with IL-12 will further improve clinical efficacy without placing the patient at risk for systemic toxicity.     

Posttransplant administration of cyclophosphamide and donor lymphocyte infusion induces potent antitumor immunity to solid tumor

PURPOSE: Nonmyeloablative allogeneic stem cell transplantation (SCT) has been increasingly used for the treatment of hematologic and solid malignancies, and mature donor T cells are considered to be the main effectors of the graft-versus-tumor (GVT) activity. However, the association between degree of donor chimerism and intensity of GVT effects has not been fully elucidated. We recently proposed a unique nonmyeloablative cell therapy using posttransplant cyclophosphamide and donor lymphocyte infusion, by which a significant antitumor effect against murine renal cell carcinoma, RENCA, was induced, although the level of mixed chimerism was relatively low. In this study, we attempted to clarify a role of chimerism for in vivo antitumor effects on GVT effects in radiation-associated nonmyeloablative SCT. EXPERIMENTAL DESIGN: We assessed antitumor effects on RENCA tumors and the degree of donor chimerism after several doses of irradiation followed by allogeneic SCT and compared the results with those of cyclophosphamide-based cell therapy. RESULTS: Allogeneic SCT following sublethal irradiation (6 Gy) induced almost complete donor chimerism, whereas cyclophosphamide-based cell therapy produced low levels of donor chimerism. Nonetheless, GVT activity was much more potent in cyclophosphamide-based cell therapy than irradiation-conditioned SCT. Furthermore, cyclophosphamide-conditioned SCT induced more potent immune reconstitution with less severe graft-versus-host disease than irradiation-conditioned SCT. CONCLUSIONS: Our results indicate that a high level of chimerism is not essential for the in vivo antitumor effect of nonmyeloablative allogeneic cell therapy against solid tumor and that the recovery of peripheral lymphocytes after the initial immunosuppression might be a critical event for the elicitation of in vivo antitumor effects of that treatment modality.     

MCF-7荷瘤裸鼠不同树突状细胞亚群凋亡的研究

目的:通过建立MCF-7荷瘤裸鼠模型,研究树突状细胞(DCs)不同亚群的凋亡,为设计新的免疫治疗方法和新的疫苗提供详尽信息。方法:建立MCF-7裸鼠模型,随机分为荷瘤组和对照组,肿块达5 mm后处死裸鼠,取骨髓单个核细胞进行DCs诱导、分化,流式细胞仪上检测表面分子标志CD86、CD83、MHC-Ⅱ及CD34,AnnexinⅤ检测CD11c及CD123了解DCs亚群的凋亡率。结果:骨髓起源单个核细胞培养至第9天出现典型DCs形态特征,荷瘤组和对照组细胞均高表达CD86、CD83及MHC-Ⅱ,而CD34表达两组均较低。荷瘤组CD11c+CD123-细胞为(52.01±1.43)%,对照组为(56.36±1.76)%;CD123+CD11c-细胞荷瘤组为(32.19±1.71)%,对照组为(28.95±1.39)%。荷瘤组mDC凋亡率为(23.64±2.43)%,较对照组(20.05±2.49)%高,P<0.05。荷瘤组小鼠pDC凋亡率为(11.53±2.92)%,较对照组(14.96±2.96)%低,P<0.05。结论:MCF-7乳腺癌小鼠体内DCs存在mDC和pDC两种亚型,mDC凋亡率增加,使诱导Th1免疫反应能力减低;而pDC凋亡率减少,诱导体内免疫耐受的发生,机体抗肿瘤免疫反应能力因而下降。     

Combination of intra-arterial administration of anticancer agent and hemocarboperfusion in treatment of advanced cancer

Nineteen patients with malignant tumors were treated with a combination of bolus administration of mitomycin C with direct hemoperfusion over charcoal, and 15 patients were valuable. Mitomycin C of 1 mg/kg was administered via a catheter placed into the regional artery. Seven out of 14 patients with genitourinary cancers: 4 out of 9 patients with urinary bladder, 2 of 4 patients with renal and one prostate responded to the therapy. There were 4 responders out of 8 in the one-shot administration group, on the other hand, 7 cases receiving continuous infusion of 60 to 120 minutes responded. In both the one-shot group and the continuous group nausea and vomiting were observed in 21% and 11% respectively. Three patients receiving continuous administration of mitomycin C had local ulcerations. Myelosuppressions such as leukocytopenia and thrombocytopenia were observed in 37% of the both groups.     

Sunitinib for treatment of advanced renal cell cancer: primary tumor response.

PURPOSE: Nephrectomy before immunotherapy in patients with metastatic renal cell cancer (RCC) will improve patient outcome. In addition, the primary tumor is known to be refractory to cytokines. Sunitinib is now approved for treatment of advanced RCC, but its effect on the primary tumor has yet to be reported. EXPERIMENTAL DESIGN: All patients treated with sunitinib for advanced RCC without prior nephrectomy were reviewed and sequential computed tomography scans were evaluated for response in the primary tumor as well as metastases according to Response Evaluation Criteria in Solid Tumors. Volumes of primary tumors and central necrotic areas were measured with the perimeter method. RESULTS: Computed tomography scans were available for evaluation of response in 17 of 22 patients with a primary tumor in situ (1 patient with two primaries). According to Response Evaluation Criteria in Solid Tumors, 4 patients had a partial response, 12 had stable disease, and 1 had progressive disease. The one-dimensional longest diameter of the primary tumor correlated with the volumetric measurements both at baseline and at the time of evaluation of response. Excluding the patient with progressive disease, the median volume reduction was 31% associated with a median increase in the volume of necrosis of 39%. Three patients underwent nephrectomy and tumors showed extensive necrotic areas next to small fields of vital tumor cells. CONCLUSIONS: Sunitinib can induce a significant reduction in volume of primary renal cell tumors. Further trials need to address the role of nephrectomy in advanced RCC patients on sunitinib treatment.     

Tumour cell lysate-loaded dendritic cell vaccine induces biochemical and memory immune response in castration-resistant prostate cancer patients

Background:

Recently, we produced a tumour antigen-presenting cells (TAPCells) vaccine using a melanoma cell lysate, called TRIMEL, as an antigen source and an activation factor. Tumour antigen-presenting cells induced immunological responses and increased melanoma patient survival. Herein, we investigated the effect of TAPCells loaded with prostate cancer cell lysates (PCCL) as an antigen source, and TRIMEL as a dendritic cell (DC) activation factor; which were co-injected with the Concholepas concholepas haemocyanin (CCH) as an adjuvant on castration-resistant prostate cancer (CRPC) patients.

Methods:

The lysate mix capacity, for inducing T-cell activation, was analysed by flow cytometry and Elispot. Delayed-type hypersensitivity (DTH) reaction against PCCL, frequency of CD8⁺ memory T cells (Tm) in blood and prostate-specific antigen (PSA) levels in serum were measured in treated patients.

Results:

The lysate mix induced functional mature DCs that were capable of activating PCCL-specific T cells. No relevant adverse reactions were observed. Six out of 14 patients showed a significant decrease in levels of PSA. DTH⁺ patients showed a prolonged PSA doubling-time after treatment. Expansion of functional central and effector CD8⁺ Tm were detected.

Conclusion:

Treatment of CRPC patients with lysate-loaded TAPCells and CCH as an adjuvant is safe: generating biochemical and memory immune responses. However, the limited number of cases requires confirmation in a phase II clinical trial.     

Genetic polymorphisms and treatment response in advanced non-small cell lung cancer

BACKGROUND: Genetic polymorphisms involved in DNA repair and apoptosis are suspected to influence patient response to cancer treatment. To evaluate the effect of genetic variations on chemotherapy and/or radiotherapy, we genotyped four single nucleotide polymorphisms (SNPs) in ATM (A60G), ERCC1 (Asn118Asn), APE1 (Asn148Glu), and iASPP (A67T), and examined their associations with treatment response among patients with advanced non-small cell lung cancer (NSCLC). METHODS: Included in the study were 230 patients diagnosed with inoperable advanced NSCLC. Of these patients, 76 received platinum-based chemotherapy, 125 received chemotherapy plus radiation, and 29 received radiotherapy only. The SNPs were genotyped using the TaqMan methods. RESULTS: Among the patients who received chemotherapy only, ERCC1 (Asn118Asn) genotype was significantly associated with treatment response. Patients with either one or two T alleles (T/T+C/T) at Asn118Asn were more likely not to respond to platinum-based chemotherapy compared to those without the T allele (OR=4.10, 95% CI: 1.31-12.85). For patients who were treated with both chemotherapy and radiotherapy, treatment response seemed to differ substantially between patients with different genotypes of iASPP (A67T). Patients carrying an A allele (A/T+A/A) at A67T were more likely to respond to combined chemotherapy and radiotherapy compared to those not carrying the A allele (OR=0.25, 95% CI: 0.08-0.74). An association with treatment response was also suggested for the selected polymorphism in APE1, but no association was found for the ATM polymorphism. CONCLUSION: We found that SNPs in ERCC1 and iASPP were associated with response to chemotherapy or combined chemotherapy and radiotherapy in NSCLC patients. These findings support the notion that genetic variations related to DNA repair or apoptosis may affect the effect of chemotherapy or radiation on NSCLC.     

肿瘤抗原致敏树突状细胞疫苗联合热疗治疗晚期非小细胞肺癌的临床观察

目的: 探讨树突状细胞疫苗联合热疗治疗晚期非小细胞肺癌的安全性和临床疗效。方法： 14例晚期非小细胞肺癌患者入组，均符合研究的纳入及排除标准，并签署知情同意书；患者单采外周血单核细胞体外培育成树突状细胞，将抗原致敏制备成的树突状细胞疫苗回输患者，回输前1 d使用     

Myeloid-derived suppressor cell inhibition of the IFN response in tumor-bearing mice

Our group and others have determined that immune effector cells from patients with advanced cancers exhibit reduced activation of IFN signaling pathways. We hypothesized that increases in immune regulatory cells termed myeloid-derived suppressor cells (MDSC) could interfere with the host immune response to tumors by inhibiting immune cell responsiveness to IFNs. The C26 murine adenocarcinoma model was employed to study immune function in advanced malignancy. C26-bearing mice had significantly elevated levels of GR1(+)CD11b(+) MDSC as compared with control mice, and splenocytes from tumor-bearing mice exhibited reduced phosphorylation of STAT1 (P-STAT1) on Tyr(701) in response to IFN-α or IFN-γ. This inhibition was seen in splenic CD4(+) and CD8(+) T cells as well as natural killer cells. In vitro coculture experiments revealed that MDSC inhibited the IFN responsiveness of splenocytes from normal mice. Treatment of C26-bearing mice with gemcitabine or an anti-GR1 antibody led to depletion of MDSC and restored splenocyte IFN responsiveness. Spleens from C26-bearing animals displayed elevated levels of iNOS protein and nitric oxide. In vitro treatment of splenocytes with a nitric oxide donor led to a decreased STAT1 IFN response. The elevation in nitric oxide in C26-bearing mice was associated with increased levels of nitration on STAT1. Finally, splenocytes from iNOS knockout mice bearing C26 tumors exhibited a significantly elevated IFN response as compared with control C26 tumor-bearing mice. These data suggest that nitric oxide produced by MDSC can lead to reduced IFN responsiveness in immune cells.     

国产吉西他滨联合顺铂治疗晚期非小细胞肺癌的疗效观察

背景与目的目前铂类药物为基础的联合化疗被认为是治疗晚期非小细胞肺癌的有效方案。本研究旨在观察国产吉西他滨(gemcitabine，GEM)与顺铂(cisplatin，DDP)联合化疗方案治疗晚期非小细胞肺癌的临床疗效及毒副反应。方法32例患者均为不能手术的Ⅲ、Ⅳ期非小细胞肺癌患者。吉西他滨1000mg／m^2静脉滴注，第1、8、15天；顺铂20mg静脉滴注，第1～5天。每28天为一个周期，治疗3～4周期。结果全组无完全缓解的患者，总有效率为34．4％(11／32)。中位生存期为329天，1年生存率为32．7％。主要毒副反应为骨髓抑制及恶心呕吐，但没有严重的Ⅳ度损害；无明显的肝肾功能损害；无一例因毒性反应而延期化疗。结论吉西他滨加顺铂联合化疗方案治疗晚期非小细胞肺癌有较好的疗效，且耐受性较好。     

多西紫杉醇联合顺铂治疗晚期非小细胞肺癌临床分析

目的:观察多西紫杉醇(艾素) 联合顺铂治疗晚期非小细胞肺癌的疗效及不良反应.方法:对病理学或细胞学证实的36例晚期非小细胞肺癌患者给予艾素联合顺铂治疗.采用分次疗法,艾素37.5mg/m2/次,静滴,第1、8天二次给药;顺铂25mg/m2/次静滴,第2-5天.每21天为1周期,每例患者均接受2周期治疗或以上.结果:全组36例中完全缓解1例,部分缓解14例,稳定14例,进展7例,总有效率41.7 %.中位生存期8.6个月,1年生存率为38.9%. 临床最常见的不良反应为骨髓抑制,Ⅲ、Ⅳ度白细胞下降率为27.8% ,其余无严重不良反应.结论:多西紫杉醇联合顺铂治疗晚期非小细胞肺癌疗效较好,不良反应较轻,采用分次疗法,病人耐受性较好,尤对老年晚期患者更加适宜.     

Combination of paclitaxel and etoposide in the treatment of advanced non-small cell lung cancer: a phase I-II study

Thirty-six patients (pts) with unpretreated advanced non-small cell lung cancer (NSCLC) stages IIIB and IV were enrolled in this two-stage phase I-II study aimed to establish the maximum tolerated dose (MTD) of paclitaxel and to evaluate the efficacy and safety of paclitaxel combined with etoposide every 3 weeks for a maximum of 6 courses, increasing the dose of paclitaxel according to a modified Fibonacci scheme. Nineteen pts were enrolled in the first stage and 17 pts in the second stage. The characteristics of the pts were as follows: median age 56 years (40-70), median Karnofsky's Performance Status 80% (70-80), 11 pts were stage IIIB and 25 pts stage IV. The doses of etoposide administered were 50 mg/m2 for 15 pts and 100 mg/m2 for 21 pts. MTD has not been reached and the study proceeded with the dose of paclitaxel 250 mg/m2. We obtained 9 (25%) partial remissions (PR) and 11 (31%) stable disease (SD) in 33 objectively evaluable pts. Median time to progression (TTP) was 4 months (0.3-21), median survival was 9.3 months (0.3-27). The main toxicity was neutropenia and neurotoxicity, while the gastrointestinal toxicity was mild. Two pts deceased after the first course. The causes of death were necrotizing enteritis in the first pt and congestive heart failure in the second pt. A total of 156 courses were administered at 7 dose levels, with a median of 4 courses per patient (1-6). The results seem to support the use of this combination in advanced non-small cell lung cancer.     

多西紫杉醇联合顺铂治疗晚期非小细胞肺癌

目的：观察多西紫杉醇联合顺铂治疗晚期非小细胞肺癌的疗效及毒副瓜。方法：对经病理学或细胞学证实的40例晚期非小细胞肺癌患者给予多西紫杉醇与顺铂联合治疗，其中多西紫杉醇75mg/m^2,静脉滴注，第1天，顺铂75－80mg/m^2，静脉滴注，第1天或分为第1－3天，21天为一周期，每例患者治疗两周期以上。结果：全组完全缓解1例，部分缓解16例，稳定15例，进展7例，总有效率为43．6％。初治组有效率为44．4％，复治组有效率为40．9％，两组间比较有效率差异无显著性（P＞0．05）。最常见的毒副反应为骨髓抑制，Ⅲ＋Ⅳ度白细胞和血小板下降率分别为17．5％和12．5％，有一例因严重骨髓抑制致颅内出血死亡，其余毒副反应均轻微可耐受。结论：多西紫彬醇联合顺铂一线治疗或二线治疗晚期非小细胞肺癌均有较好的疗效，毒性可以耐受，但应注意防治严重的骨髓抑制。     

Serum CYFRA 21-1 in advanced stage non-small cell lung cancer: an early measure of response.

OBJECTIVES: Our objective was to test the prognostic importance of both the pretreatment level and change in serum CYFRA 21-1 after one cycle of chemotherapy in patients with advanced non-small cell lung cancer (NSCLC) and to compare these two CYFRA variables to routine clinical stage and response as measured by imaging. PATIENTS AND METHODS: Our patients consisted of 58 with advanced NSCLC who were treated with chemotherapy. Fourteen were stage IIIa, 8 stage IIIb, and 36 stage IV, and none had received previous treatment. The choice of chemotherapy was left to the discretion of the treating physicians. We collected two serum samples, one before the first cycle of chemotherapy and the second before the second cycle, and analyzed these for serum CYFRA 21-1 using an electrochemiluminescence immunoassay and the ElecSys 2010 system (Roche Diagnostics Corp., Indianapolis, IN). We expressed changes in CYFRA in terms of the natural ratio logarithm of post-treatment to pretreatment CYFRA, and we used the Cox proportional hazards model to analyze survival time. RESULTS: Patients experienced an average drop of 27% in serum CYFRA after the first cycle of chemotherapy. Furthermore, the Cox model demonstrated that both the initial natural logarithm of serum CYFRA and presence of >27% drop in CYFRA were significantly related to subsequent survival (model P < 0.0006), but neither clinical stage nor clinical response related to survival (P > 0.1). CONCLUSION: In advanced stage NSCLC, the initial level of serum CYFRA appears to provide more prognostic information than clinical stage. Furthermore, a drop of >27% in CYFRA after one cycle of therapy adds prognostic information, so that this threshold appears to be an early measure of response to chemotherapy.     

吉西他滨联合卡铂治疗晚期非小细胞肺癌

目的　观察吉西他滨联合卡铂治疗晚期非小细胞肺癌的疗效及毒副反应。方法　 41例晚期非小细胞肺癌患者给予吉西他滨与卡铂联合治疗 ,吉西他滨 10 0 0mg/m2 ,静脉滴注第 1、8、15天 ,卡铂AUC 5 ,静脉滴注第 1天 ,2 8天为一周期 ,每例患者治疗 2周期以上。结果　全组完全缓解 2例 ,部分缓解 18例 ,稳定15例 ,进展 6例 ,总有效率为 48.8%。初治组有效率为 5 5 .6% ,复治组为 43 .5 % (P >0 .0 5 )。全组中位生存期 11.8月 ,1年生存率为 49%。KPS评分增加者占 70 .7% ( 2 9/4 1)。最常见的毒副反应为骨髓抑制 ,Ⅲ～Ⅳ度白细胞和血小板下降发生率分别为 3 4.1%和 2 9.3 % ,其余毒副反应均轻微 ,可耐受。结论　吉西他滨联合卡铂一线治疗或二线治疗晚期非小细胞肺癌均有较好的疗效 ,毒性可以耐受。     

艾素联合卡铂治疗晚期非小细胞肺癌临床研究

目的:观察艾素(国产多西紫杉醇)联合卡铂治疗晚期非小细胞肺癌(NSCLC)的临床疗效与不良反应.方法:80例经手术和病理证实的晚期非小细胞肺癌患者,观察组49例,用艾素联合卡铂化疗;对照组31例,用异长春花碱联合顺铂化疗.观察两组疗效和毒副作用,3周期后评价疗效.结果:两组患者近期总有效率(PR)分别为44.9%(22/49)和41.94%(13/31).主要毒副作用为骨髓抑制,消化道反应和脱发,其发生率无显著性差异(P＞0.05).结论:艾素与卡铂联合给药方案治疗非小细胞肺癌疗效满意,耐受性好,不良反应少,性价比高.     

Mebendazole elicits a potent antitumor effect on human cancer cell lines both in vitro and in vivo.

We have found that mebendazole (MZ), a derivative of benzimidazole, induces a dose- and time-dependent apoptotic response in human lung cancer cell lines. In this study, MZ arrested cells at the G(2)-M phase before the onset of apoptosis, as detected by using fluorescence-activated cell sorter analysis. MZ treatment also resulted in mitochondrial cytochrome c release, followed by apoptotic cell death. Additionally, MZ appeared to be a potent inhibitor of tumor cell growth with little toxicity to normal WI38 and human umbilical vein endothelial cells. When administered p.o. to nu/nu mice, MZ strongly inhibited the growth of human tumor xenografts and significantly reduced the number and size of tumors in an experimental model of lung metastasis. In assessing angiogenesis, we found significantly reduced vessel densities in MZ-treated mice compared with those in control mice. These results suggest that MZ is effective in the treatment of cancer and other angiogenesis-dependent diseases.