DC-CIK Group Research Articles

Immune Effect of Co-Culture of Dendritic Cells and Cytokine-Induced Killer Cells on Prostate Cancer Cells.

It was to explore the immune outcome of co-culture of dendritic cells (DC) and cytokine-induced killer cells (CIK) on prostate cancer (PCa) cells. Peripheral blood mononuclear cells (PBMCs) were extracted from healthy blood donors. DC and CIK cells were induced and co-cultured. The proliferation and phenotypic changes of DC, CIK, and DC-CIK cells/groups were observed. Model rats were constructed by injecting PC3 PCa cells into the abdominal cavity. The successful 50 cases were divided into a negative control group, a chemotherapy group, a DC group, a CIK group, and a DC-CIK treatment group (each consisting of 10 rats) to observe tumor progression. The secreted concentrations of interleukin-12 (IL-12) ((103.67 ± 2.77) pg/mL) and interferon-γ (IFN-γ) ((730.09 ± 23.52) pg/mL) were higher in DC-CIK group as against DC and CIK groups; the proliferation of CIK was higher in DC-CIK group as against CIK within 12 to 20 days of culture. The positive rate (PR) of CD3+/ CD56+ and CD8+ was higher and that of CD45RA+ was lower in DC-CIK group as against CIK.The killing rate of the DC-CIK group was higher than that of the DC and CIK groups at a target effect ratio of 10:1/20:1/50:1 (P < 0.05). After the treatment, the body weight of rats in the chemotherapy group, DC group, and CIK group was significantly reduced (P < 0.05), while no significant changes were observed in the negative control group and DC-CIK group (P > 0.05). After 25 days of treatment, the tumor size in the DC-CIK group was significantly smaller compared to the negative control group, chemotherapy group, DC group, and CIK group; the necrotic area of the tumor tissue in the DC-CIK group was also significantly larger than that in the negative control group, chemotherapy group, DC group, and CIK group (P < 0.05). Co-culture of DC and CIK is excellent in enhancing the proliferation of CIK cells, increasing the secretion of IL-12 and IFN-γ, and enhancing the activity of immune cells and anti-tumor ability, showing its potential in anti-PCa tumor immunotherapy.

Efficacy of DC-CIK Immunotherapy Combined with Chemotherapy on Locally Advanced Gastric Cancer.

The aim of the study is to explore the efficacy and safety of dendritic cell-cytokine-induced killer cell (DC-CIK) immunotherapy combined with chemotherapy in the treatment of locally advanced gastric cancer (LAGC). Among 106 patients with LAGC, 53 received the treatment of oxaliplatin-5-fluorouracil chemotherapy (control group), while the remaining 53 received DC-CIK immunotherapy combined with chemotherapy (DC-CIK group). The short-term efficacy and the changes in immune function indexes (cluster of differentiation (CD)3+, CD4+, CD8+, CD4+/CD8+, and natural killer (NK) cells) were analyzed. The overall response rate (ORR) was 47.2% (25/53) and 41.5% (22/53), and the disease control rate (DCR) was 69.8% (37/53) and 50.9% (27/53), respectively, in the DC-CIK group and the control group. It could be seen that the ORR had no statistically significant difference between the two groups, while the DCR in the DC-CIK group was significantly better than that in the control group. After treatment, the proportions of CD3+ T lymphocytes, CD4+ T lymphocytes, CD4+/CD8+ cells, and NK cells obviously rose, while the proportion of CD8+ T lymphocytes obviously declined in the DC-CIK group compared with those in the control group. After treatment, the scores in the function module of the QLQ-C30 scale were greatly higher in the DC-CIK group than those in the control group, while the scores of loss of appetite, constipation, dyspnea, fatigue, pain, and sleep disorders in the symptom module were significantly lower in the DC-CIK group than those in the control group. The median survival time was 23.4 months and 18.6 months, respectively, in the DC-CIK group and the control group. The results of the log-rank test showed that the OS in the DC-CIK group was remarkably superior to that in the control group. DC-CIK immunotherapy combined with chemotherapy can improve the immune cell function, ameliorate the quality of life, and prolong the survival time of LAGC patients, with fewer adverse reactions.

Efficacy of cytokine-induced killer therapy following operation of renal cell carcinoma in north China

Purpose: The purpose of the study was to evaluate the antitumor activity of CIK cells in vitro and investigate the clinical efficacy of cytokine-induced killer (CIK) therapy following operation of renal cell carcinoma patients in North China. Method: In vitro experiments, the secretion of IFN-γ and IL-2 in CIK cells were detected by ELISA and the degranulation was detected by flow cytometry. From January 1, 2012 to October 1, 2015, 202 patients were enrolled in the study and were followed up for at least 36 months. The information of 101 patients who received CIK treatment following nephrectomy and other 101 patients who only received nephrectomy was retrospectively collected. In addition, the correlation of CIK treatment to prognosis of patients following nephrectomy, including disease-free survival (DFS) and overall survival (OS), was analyzed by Kaplan-Meier analyses. COX proportional hazards analyses were used to investigate the benefited population. Results: In vitro, DC-CIK group exhibited the highest cytokines secretion and cytotoxicity followed by the CIK group. In addition, survival analysis showed that patients in North China who received CIK therapy has better prognosis compared to the control group. And the COX proportional hazards analyses demonstrated that in North China, patients with different characteristics can benefit from CIK treatment at the same. Conclusions: CIK immunotherapy is an effective and safety adjuvant for the patients with ccRCC following nephrectomy in North China.

Study of proliferation ability of tumor antigen-loaded DC-CIK cells and its killing effect on hepatocarcinoma cells HepG2

Objective To observe the proliferation ability of cocultured dendritic cells (DCs) loaded with tumor antigen and cytokine-induced killer cells (CIKs) and its killing effect on hepatocarcinoma cells HepG2. Methods The antigen of hepatocarcinoma cells HepG2 was prepared by repeated freezing and thawing of liquid nitrogen. Peripheral blood mononuclear cells (PBMNCs) were isolated from healthy donors by blood cell separator, then DCs and CIKs were induced. Ag-DCs were obtained by impinging DCs with tumor antigens. CIKs were divided into three groups: the first group was CIKs alone, the second group was mixed in the proportion of DCs∶CIKs=1∶5, and the third group was mixed in the proportion of Ag-DCs∶CIKs=1∶5. The three groups of cells were recorded as CIK group, DC-CIK group and Ag-DC-CIK group. The proliferation and cell phenotype of the three groups of cells were observed and the killing effects on hepatocarcinoma cells HepG2 were detected by methyl thiazolyl tetrazolium (MTT) assay. Results The proliferation multiples of the three groups of cells were gradually increased with the prolongation of culture time, and the proliferation rates of Ag-DC-CIK on the 9th day (61.32±1.72), the 12th day (190.83±3.53) and the 15th day (399.09±5.60) were significantly higher than those of CIK group (22.47±2.07, 55.91±1.81, 83.20±2.34) and DC-CIK group (40.26±2.49, 125.03±4.16, 251.55±3.25), and the difference between the three group was statistically significant (F=185.78, P=0.033; F=297.35, P=0.018; F=455.37, P<0.001), in addition, the differences between each two groups were statistically significant (all P<0.05). The cytotoxicity of Ag-DC-CIK to HepG2 cells at the effective target ratios of 5∶1 (31.71%±0.29%), 10∶1 (42.43%±1.86%) and 20∶1 (57.69%±1.11%) were significantly higher than those of CIK group (12.11%±1.14%, 21.30%±0.52%, 30.71%±1.26%) and DC-CIK group (20.06%±0.67%, 29.89%±1.37%, 39.11%±0.92%), and the difference between the three group was statistically significant (F=159.64, P=0.037; F=199.36, P=0.025; F=302.08, P<0.001), in addition, the differences between each two groups were statistically significant (all P<0.05). On the 15th day of cell culture, the flow cytometry analysis showed that all the three groups were expressed CD3+ CD8+ , CD3+ CD56+ double positive cells, the contents of CD3+ CD8+ 、CD3+ CD56+ double positive cells in the Ag-DC-CIK group (88.12%±1.24%, 61.35%±2.63%) were significantly higher than those in the CIK group (54.37%±3.08%, 18.22%±1.83%) and DC-CIK group (69.80%±1.46%, 39.51%±2.17%), and the difference between the three group was statistically significant (F=414.32, P<0.001; F=378.60, P<0.001), in addition, the differences between each two groups were statistically significant (all P<0.001). Conclusion The proliferation ability and killing effect of Ag-DC-CIK that obtained from antigen-pulsed DCs co-cultured with CIKs are significantly higher than those of CIKs and DC-CIKs. Key words: Dendritic cells; Killer cells; Cell line, tumor

Retrospective analysis on the efficacy of sunitinib/sorafenib in combination with dendritic cells-cytokine-induced killer in metastasis renal cell carcinoma after radical nephrectomy.

Sunitinib/sorafenib (SU/SO), dendritic cells (DCs), or DC-cytokine-induced killer (CIK) could significantly prolong progression-free survival (PFS), 3-year overall survival (OS), or 5-year OS for patients with metastatic renal cell carcinoma (mRCC). We retrospectively analyzed the clinical efficacy between SU/SO combined with DC-CIK and SU/SO monotherapy in treating renal cell carcinoma (RCC) patients with metastasis after radical nephrectomy. All patients (n = 34) with postoperative mRCC in our hospital from January 2009 to January 2014 were received either SU/SO monotherapy (Group 1, n = 15) or in combination with DC-CIK (Group 2, n = 19). A retrospective study was based on the primary endpoint (PFS) and secondary endpoint (OS). At a median follow-up of 19.5 months, in Group 2, as compared with in Group 1, the median PFS was significantly longer (28.0 vs. 11.0 months, P = 0.03). Moreover, the 3-year OS was higher (57.1% vs. 28.6%). The cases of progressive diseases (PDs) and deaths were less in Group 2 than that in Group 1 (PD: 8 vs. 9, deaths: 3 vs. 5); however, the cases of stable diseases were more (11 vs. 6). In addition, the 3-year OS was higher in SU + DC-CIK group than that in SO + DC-CIK group (63.36% vs. 50%). There was no significant difference for PFS between SO + DC-CIK group and SU single agent group. SU/SO with DC-CIK could significantly prolong the median PFS, improve the 3-year OS rate, prolong the 3-year OS. It is likely to be a new approach for mRCC after radical nephrectomy.

Killing effect of Huaier combined with DC-CIK on nude mice bearing colon cancer HT29 stem cells in vivo

To compare the therapeutic effects of different treatment methods on the nude mice bearing colon cancer HT29 cells. BalB/C nude mice colon cancer stem cell models were established and randomly divided into the following four groups, with 8 nude mice in each group: blank control group, DC-CIK group, Huaier group, and Huaier combined with DC-CIK group (combined treatment group). The mice in DC-CIK group and combined treatment group received 1×10⁶ DC-CIK cells treatment by tail vein injectionafter the tumor stem cells were inoculated for 4 days,2 times a week for three weeks. The mice in Huaier group and combined treatment group received intragastric administration at the dose of 20 g/60 kg body weight, 0.2 mL/time, once a day for a total of three weeks. The mice in control group received equal volume of normal saline. Tumor size and body weight of nude mice were measured every 2 days during treatment for three weeks in each group. After the treatment, the nude mice were sacrificed to measure the tumor weight and the tumor inhibition rate was calculated. The RT-PCR method was used to detect the expression levels of the key genes in the signal pathway. After the end of the treatment, the quality of the tumor in the Huaier group, DC-CIK group and combined treatment group was significantly lower than that in the control group; the quality in combined treatment group was significantly lower than that in Huaier group and DC-CIK group.Among them, the tumor inhibition rate reached 46.77% in the combined treatment group. In respect of changes in expression levels of key genes in the signaling pathway, the mRNA expression levels of key genes PI3KR1 and Akt in PI3K/Akt pathway, key genes Wnt1 and CTTNB1 in Wnt/β-catenin pathway, and key genes Notch1, Notch2, Notch3 in Notch pathway in the combined treatment group were lower than those in DC-CIK group and Huaier group. The Huaier combined with DC-CIK group showed best therapeutic effect among different treatment methods for HT29 stemcell colon tumors in nude mice, providing a new idea for clinical treatment of colon cancer.

An experimental study on DC-CIK cells' immuno effects on killing gastric cancer cells in vitro

Objective: To investigate the anti-gastric cancer immuno effects of DC-CIKs against gastric cancer cells by co-culturing Dendritic Cells (DCs) with Cytokine-Induced Killer cells (CIKs) derived from peripheral blood mononuclear cells of patients with gastric carcinoma. Methods: Collecting 30 ml peripheral blood of patient of gastric cancer, we separate peripheral blood with lymphocyte separation liquid to obtain mononuclear cells respectively, and used for generating DC with the treatment of recombinant human Granulocyte Macrophage Coliny Stimulating Factor (rhGMCSF) and recombinant human Interleukin-4 (rhIL-4) as well producing CIK with interferon-γ (IFN-γ), CD3 and rhIL-2 in vitro, mixing SGC-7901 cells of DC and CIK cells and then DC and CIK were cocultured according to the ratio of 1:10 to produce DC-CIK. The experiment was performed with three groups composed of DC-CIK group, DC group and CIK group. After 14 d of co-culture, increased number of cells were counted by trypan blue staining, cytotoxic activity against SGC-7901 cells in three groups were detected by MTT assay. The Flow Cytometry (FCM) was used to measure the antigen expression of the CD1a, CD83, CD86, CD80, CD40, HLA-DR and the lymphocyte subsets of CD3+, CD3+CD8+ and CD3+CD56+ of the three groups cells. Levels of Interleukin-12 (IL-12), Interleukin-4 (IL-4), the Interferon-γ (IFN-γ) and Tumor Necrosis Factor-α (TNF-α) in the supernatants of DC-CIK, DC and CIK cells culture were detected by Enzyme-Linked Immunosorbent Assay (ELISA). Results: After culturing for 14 d in vitro, the proliferation capability and the cells percentage of antigen expression of peripheral blood DC-CIK cells was significantly higher than that of DC and CIK cells (p 0.05). Conclusion: DC-CIK can induce potent immunological effect against gastric cancer cells. Immuno efficacy of DC-CIK against gastric cancer is relevant to cytokine and cytotoxicity, which provides theoretical and experimental basis for the clinical immunotherapy of gastric cancer.

Enhanced antitumor effects and improved immune status of dendritic cell and cytokine-induced killer cell infusion in advanced cancer patients.

Little progress has been made in the treatment of advanced cancer. Dendritic cells (DCs) plus cytokine-induced killer (CIK) cells have exhibited antitumor effects. Thus, the aim of the present study was to evaluate the clinical efficacy of DC-CIK cell treatment in patients with advanced cancer. A paired study including 57 patients treated with DC-CIK cells (DC-CIK group) and 33 patients treated with best supportive care alone (BSC group) was performed. The patients in the DC-CIK group were matched to those in the control group in terms of sex, age, tumor type and clinical stage. T-cell subsets were detected and overall survival (OS) was compared between the two groups. The results demonstrated that CD4+/CD25+ and CD8+/CD28- subsets significantly decreased following DC-CIK immunotherapy (P<0.05). The CD3+, CD3+/CD8+, CD8+/CD28+ and CD3+/CD56+ T-cell subsets were significantly increased in the DC-CIK group compared with the BSC group, while the CD8+/CD28- subset was significantly decreased. Univariate analysis demonstrated that a lower CD8+/CD28- and a higher CD8+/CD28+ ratio were associated with prolonged OS in advanced cancer patients. In addition, DC-CIK treatment administration, age (>60 vs. <60 years), clinical stage and the frequency of CIK treatment significantly affected the OS of patients in the DC-CIK group. A CD8+/CD28- ratio of <21.12 was found to decrease the hazard ratio (HR) of OS to 0.50 [95% confidence interval (CI): 0.29-0.87] and a CD8+/CD28+ ratio >9.04 was found to decrease the HR of OS to 0.45 (95% CI: 0.21-0.98). No serious side effects were observed in the DC-CIK group. Taken together, these data indicate that DC-CIK infusions were able to change the ratios of the T-cell subsets, which increased the T helper cell and cytotoxic T lymphocyte subsets, while it decreased regulatory T lymphocyte subsets. Thus, this method of immunotherapy was found to improve the imbalance in the immune system and prolong the OS in patients with advanced cancer.

Killing effects of Huaier Granule combined with DC-CIK on nude mice transplanted with colon carcinoma cell line.

This study aims to compare the efficacy of different treatments for nude mice transplanted with HT-29 colon carcinoma cell line. BalB/C nude mice were transplanted with HT-29 colon carcinoma cell line and randomly divided into four groups, with 5 mice in each group: blank control group, DC-CIK group, Huaier Granule group, and Huaier Granule group combined with DC-CIK group (combined treatment group). For DC-CIK group and combined treatment group, 1×106 DC-CIK cells were injected via the tail vein 4 days after transplantation. The injection was performed twice weekly for a total of 2 weeks. For Huaier Granule group and combined treatment group, Huaier Granule was administered at the dose of 20 g/60 g, by dissolving 20 g of Huaier granules in 600 ml of pure water. Intragastric administration of 0.2 ml of granules was performed once daily for 3 weeks. For the blank control group, equal volume of normal saline was given. Tumor size and body weight of nude mice were measured every 2 days during the 3-week treatment. The mice were sacrificed at the end of treatment to harvest tumors. Key genes of the signaling pathway were detected by RT-PCR. At the end of treatment, mice in combined treatment group, DC-CIK group and Huaier Granule group remained stable emotionally with normal mobility and water and food intake. However, in the blank control group, the mobility was restricted starting from the third week and the mice were on the verge of dying. The expression of PI3KR1, Akt, Wnt1, CTTNB1, Notch1, Notch2 and Notch3 genes were all downregulated significantly in the combined treatment group compared with DC-CIK group and Huaier Granule group (P<0.05). Therefore, the combined treatment of Huaier Granule combined with DC-CIK achieved the best effect in nude mice transplanted with HT-29 colon carcinoma cell line.

The Efficacy and Safety of Dendritic Cells Co-Cultured with Cytokine-Induced Killer Cell Therapy in Combination with TACE-Predominant Minimally-Invasive Treatment for Hepatocellular Carcinoma: a Meta-Analysis.

To evaluate the efficacy and safety of dendritic cells (DCs) co-cultured with cytokine-induced killer cell (CIK) immunotherapy combined with transcatheter arterial chemoembolization (TACE) or TACE plus local ablation therapy for hepatocellular carcinoma (HCC). Our meta-analysis included a comprehensive search for relevant studies published through December 12, 2014. We used Cochrane Library, PubMed, CBM, VIP, CNKI, and Wanfang data. Depending on the heterogeneity among the included studies, we calculated the pooled odds ratio (OR) and mean difference (MD) using fixed- or random-effects models. Publication biases were assessed using funnel plots and Begg's tests. Sensitivity analyses were also performed. Seven randomized controlled trials (RCTs) and one controlled clinical trial (CCT) that included 693 patients and met the inclusion criteria were analyzed. Pooled results showed that DC-CIK immunotherapy combined with TACE or TACE plus local ablation therapy significantly improved 1-year (OR = 2.00, p = 0.02) and 2-year overall survival (OR = 1.77, p = 0.04). A favored overall response rate (ORR) (OR = 1.51, p = 0.03), disease control rate (DCR) (OR = 1.81, p = 0.01), and better quality of life (OR = 3.30, p < 0.01) were observed in the DC-CIK group. Additionally, when tumor-associated T lymphocyte subsets were compared, our analyses demonstrated that the percentage of CD3+ T cells (MD(CD3+) = 21.37, p = 0.005) and the ratio of CD4+/CD8+ (MD(CD4+/CD8+) = 2.83, p = 0.02) were significantly increased in the DC-CIK therapy group. The combination of DC-CIK immunotherapy and TACE or TACE plus local ablation therapy improves 1- and 2-year overall survival, ORR, DCR, and provides a better quality of life for patients with HCC.

Combination of chemotherapy and immunotherapy for colon cancer in China: A meta-analysis

To investigate whether autologous dendritic cell (DC)-cytokine-induced killer (CIK) cell therapy is able to improve the therapeutic efficacy of chemotherapy in colon cancer. We conducted a systematic review of published papers from the sources of MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, the Wanfang Database, the China Science and Technology Periodical Database and China Journal Net. Published data were extracted independently by two authors using predefined database templates. The quality of the data from individual papers was also assessed. The effects of chemotherapy were compared with those of chemotherapy in combination with DC-CIK immunotherapy. The pooled analysis was performed using the data from random or fixed-effect models. Seven trials matched our inclusion criteria (n = 533). The overall analysis showed significant survival benefit [one-year overall survival (OS), P < 0.0001; two-year OS, P = 0.009; three-year OS, P = 0.002] in favor of DC-CIK immunotherapy combined with chemotherapy. Disease-free survival (DFS) rate was improved after the combination of DC-CIK immunotherapy and chemotherapy (one-year DFS, P < 0.0001; two-year DFS, P = 0.002; three-year DFS, P = 0.02). An improved overall response rate (P = 0.009) was also observed in patients who received DC-CIK therapy. Furthermore, the analysis of T-lymphocyte subsets in peripheral blood indicated that the number of CD4⁺ T cells significantly increased in the DC-CIK plus chemotherapy group (P < 0.05). The combination of DC-CIK immunotherapy and chemotherapy was superior in prolonging the survival time and enhancing immunological responses.

Effects of two different immunotherapies on triple negative breast cancer in animal model

The ability of immune system to react specifically against tumors inspirited the study of triple negative breast cancer (TNBC) immunotherapies. Sixty spontaneous breast cancer TA2 mice were randomly divided into three groups: GM-CSF group, with therapy of granulocyte–macrophage colony-stimulating factor (GM-CSF) combined with breast cancer stem cells associated antigens and cytosine–phosphorothioate–guanine oligodeoxynucleotides (CpG-ODNs); DC–CIK group, with infusions of dendritic cells/cytokine-induced killer (DC/CIK) cells; and PBS group as controls. After therapy, the cellular immunity of mice in GM-CSF group and DC–CIK group was obviously increased, especially for GM-CSF group (P<0.05), tumor regression was obviously observed in GM-CSF group. The survival rate of mice in GM-CSF group was significantly higher compared to DC–CIK group and PBS group. These results indicated that tumor immunotherapy manifested strong killing activity against TNBC. The therapeutic effect of GM-CSF combined with antigens and CpG was better than DC–CIK cells.

Inhibitory effect of dendritic cells combined with cytokine-induced killer cells on the growth and liver metastasis of human primary malignant melanoma of the small intestine

Objective To investigate the inhibitory effect of dendritic cells (DCs) and homologous cytokine-induced killer cells (CIKs) on the growth and liver metastasis of human primary malignant melanoma of the small intestine. Methods A histologically intact liver metastasis fragment derived from a surgical specimen of patients with primary malignant melanoma of the small intestine was implanted in the mucous layer of small intestine in nude mice to construct the liver metastasis model of the malignant melanoma. Peripheral blood mononuclear cells from healthy donors and patients with malignant melanoma of the small intestine were isolated. DCs and CIKs were separately produced according to corresponding culture method, and the DC-CIKs were harvested after coculorthotopically implanted in 56 nude mice, and 72 hours later, all the mice were equally divided into normal saline group (0.3 ml), mitomycin treatment group (400 μg/0.3 ml), healthy donor CIK group (6 × 107/0.3 ml),healthy donor DC-CIK group (3 × 107/0.3 ml), autologous CIK treatment group (6 × 107/0.3 ml), autologous DC-CIK group (6 × 107/0. 3 ml) and DC-CIK (6 × 107/0.3 ml) + mitomycin (400 μg/0. 3 ml) treatment group. Mice in the experimental groups were administered the agents once daily by vena caudalis injection for 28 days. Mice were sacrificed 72 hours after treatment, and the orthotopic xenografts were removed for weighing,and the liver metastases were simultaneously evaluated by macroscopy and microscopy. All data were analyzed using the analysis of variance, LSD test and chi-square test. Results A liver metastatic model of human primary malignant melanoma of the small intestine ( HSIM-0603 ) was established. Of the control group, healthy donor CIK group, healthy donor DC-CIK group, autologous CIK treatment group, autologous DC-CIK group and DC-CIK +mitomycin group, the tumor weights were ( 1.18 ± 0. 17), (0.71 ± 0.06), (0.68 ± 0. 15 ), (0. 43 ± 0.08 ),(0.67 ± 0.07 ), (0.37 ± 0.08 ) and (0.20 ± 0.05 ) g, respectively; the tumor inhibition rates were 0, 39.82%,42.37%, 65.56%, 43.22%, 68.64% and 83.05%, respectively; liver metastases were detected in 8, 8, 5,4, 4, 3, 2 rats, respectively, in the above mentioned groups. There were significant differences in the tumor weight, tumor inhibition rate and liver metastasis rate among the seven groups (F = 152. 300, x2= 200. 538,94. 325, P ＜ 0.05 ). Conclusions The liver metastatic model could be applied to the studies on the pathogenesis,invasion, metastasis and treatment of human primary malignant melanoma of the small intestine. DC-CIK has the potential in inhibiting the growth and liver metastasis of the malignant melanoma of the small intestine. Key words: Neoplasms of small intestine; Malignant melanoma; Liver metastasis; Animal model; Dendritic cells; Killer cells; Immunotherapy