Review of Chinese clinical trials on CIK cell treatment for malignancies

Clinical application of cytokine-induced killer (CIK) cell therapy in colorectal cancer: Current strategies and future challenges

Colorectal cancer (CRC) remains a significant global health burden and is the second leading cause of cancer-related death. Cytokine induced killer (CIK) cell therapy is an immunotherapy which has the potential to meet this need. Clinical trials of CIK cell therapy for the management of CRC have reported improved clinical outcomes. However, production and delivery protocols varied significantly, and many studies were reported only in Chinese language journals. Here we present the most comprehensive review of the clinical CIK cell therapy trials for CRC management to date. We accessed both English and Chinese language clinical studies, and summarise how CIK cell therapy has been implemented, from manufacturing to patient delivery. We discuss current challenges that impede wider adoption of CIK cell therapy in CRC management.

Use of cytokine-induced killer cell therapy in patients with colorectal cancer: a systematic review and meta-analysis

BACKGROUND

The number of clinical studies evaluating the benefit of cytokine-induced killer cell (CIK) therapy, an adoptive immunotherapy, for colorectal cancer (CRC) is increasing. In many of these trials, CIK therapy was coadministered with conventional cancer therapy. The aim of this review is to systematically assess the available literature, in which the majority were only in Chinese, on CIK therapy for the management of CRC using meta-analysis and to identify parameters associated with successful CIK therapy implementation.

METHODS

Prospective and retrospective clinical studies which compared CIK therapy to non-CIK therapy in patients with CRC were searched for electronically on MEDLINE, Embase, China National Knowledge Infrastructure, and Wanfang Data databases. The clinical endpoints of overall survival (OS), progression-free survival (PFS), OS and PFS rates, overall response rate (ORR), and toxicity were meta-analyzed using HR and relative ratio (RR), and subgroup analyses were performed using chi-square (χ2) test and I-squared (I2) statistics for study design, disease stage, cotherapy type, and timing of administration.

RESULTS

In total, 70 studies involving 6743 patients were analyzed. CIK therapy was favored over non-CIK therapy for OS (HR=0.59, 95% CI: 0.53 to 0.65), PFS (HR=0.55, 95% CI: 0.47 to 0.63), and ORR (RR=0.65, 95% CI: 0.57 to 0.74) without increasing toxicity (HR=0.59, 95% CI: 0.16 to 2.25). Subgroup analyses on OS and PFS by study design (randomized vs non-randomized study design), disease stage (Stage I-III vs Stage IV), cotreatment with dendritic cells (DCs) (CIK vs DC-CIK therapy), or timing of therapy administration (concurrent vs sequential with coadministered anticancer therapy) also showed that the clinical benefit of CIK therapy was robust in any subgroup analysis. Furthermore, cotreatment with DCs did not improve clinical outcomes over CIK therapy alone.

CONCLUSION

Compared with standard therapy, patients who received additional CIK cell therapy had favorable outcomes without increased toxicity, warranting further investigation into CIK therapy for the treatment of CRC.

Cell transfer-based immunotherapies in cancer: A review

In cell transfer therapy (CTT), immune cells such as innate immune-derived natural killer cells and dendritic cells as well as acquired immune-related T lymphocytes such as tumor-infiltrating lymphocytes and cytokine-activated or genetically modified peripheral blood T cells are used in the management of cancer. These therapies are increasingly becoming the most used treatment modality in cancer after tumor resection, chemotherapy, and radiotherapy. In adoptive cell transfer, the lymphocytes isolated from either a donor or the patient are modified ex vivo and reinfused to target malignant cells. Transferring in vitro-manipulated immune cells produces a continuous antitumor immune response. In this review, we evaluate the recent advances in CTT for the management of various malignancies.

Immunotherapy with dendritic cells and cytokine-induced killer cells for hepatocellular carcinoma: A meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) has been revealed as the second most common cause of cancer-related deaths worldwide. The introduction of cell-based immunotherapy, including dendritic cells (DCs) and cytokine-induced killer cells (CIKs), has brought HCC patients an effective benefit. However, the efficacy and necessity of cellular immunotherapy after different interventional therapy remains to be further explored.

AIM

To investigate the efficacy of cellular immunotherapy, involving DCs and CIKs, combined with different conventional treatments of HCC.

METHODS

We performed a literature search on PubMed and Web of Science up to February 15, 2019. Long-term efficacy (overall survival and recurrence) and short-term adverse effects were investigated to assess the effectiveness of immunotherapy with DCs and/or CIKs. Review Manager 5.3 was used to perform the analysis.

RESULTS

A total of 22 studies involving 3756 patients selected by eligibility inclusion criteria were forwarded for meta-analysis. Combined with the conventional clinical treatment, immunotherapy with DCs and/or CIKs was demonstrated to significantly improve overall survival at 6 mo [risk ratio (RR) = 1.07; 95% confidence interval (CI): 1.01-1.13, P = 0.02], 1 year (RR = 1.12; 95%CI: 1.07-1.17, P < 0.00001), 3 years (RR = 1.23; 95%CI: 1.15-1.31, P < 0.00001) and 5 years (RR = 1.26; 95%CI: 1.15-1.37, P < 0.00001). Recurrence rate was significantly reduced by cellular immunotherapy at 6 mo (RR = 0.50; 95%CI: 0.36-0.69, P < 0.0001) and 1 year (RR = 0.82; 95%CI: 0.75-0.89, P < 0.00001). Adverse effect assessment addressed that immunotherapy with DCs and/or CIKs was accepted as a safe, feasible treatment.

CONCLUSION

Combination immunotherapy with DCs, CIKs and DC/CIK with various routine treatments for HCC was evidently suggested to improve patients' prognosis by increasing overall survival and reducing cancer recurrence.

Enhanced metabolic activities for ATP production and elevated metabolic flux via pentose phosphate pathway contribute for better CIK cells expansion

Objective

Ex vivo expansion is an effective way to produce cytokine‐induced killer (CIK) cells needed for clinical trials. Here, ex vivo expansion and metabolism characters of CIK cells in static and dynamic cultures and the relationship between cell expansion and metabolism were investigated.

Materials and methods

Oxygen transfer efficiency was assessed by computational fluid dynamics technique. Cell phenotype, apoptosis and of transporter expression were determined by flow cytometry and Western blotting. Metabolites and enzyme activities were assessed by biochemical methods.

Results

Dynamic cultures favoured better CIK cell expansion without impairing their phenotype and cytotoxicity, enhanced oxygen transfer efficiency. The glucose metabolism flux of cells in dynamic cultures was enhanced by upregulating surface glucose transporter 1 expression and phosphofructokinase activity. Moreover, pentose phosphate pathway (PPP) metabolic flux was enhanced through upregulating glucose‐6‐phosphate dehydrogenase activity. Glutaminolysis was also accelerated via boosting glutamine transporters expression, glutaminase (GLS) and glutamate dehydrogenase activities. Together with higher oxygen consumption rate and extracellular acidification rate, it was suggested that cells in dynamic cultures were in a more vigorous metabolic state for ATP production.

Conclusion

Dynamic cultures accelerated glucose and glutamine metabolic flux to promote ATP production, elevated glucose metabolic flux through PPP to promote biosynthesis for better cell expansion. These findings may provide the basis for ex vivo CIK cell expansion process optimization.

A dynamic transcriptomic atlas of cytokine-induced killer cells

Several clinical immunotherapy trials with cytokine-induced killer (CIK) cells have been reported. However, molecular evidence of cell expansion, acquisition of tumor cytotoxicity, and safety of CIK cells is required before putting them to clinical use. Here, we performed dynamic transcriptomic analyses of CIKs generated from primary peripheral blood mononuclear cells exposed to interferon-γ, OKT3, and interleukin-2. CIK mRNAs were extracted and sequenced at days 0, 1, 7, and 14 and subjected to bioinformatics analyses. Using weighted correlation network analysis (WGCNA), we identified two major gene modules that mediate immune cell activation and mitosis. We found that activation and cytotoxicity of CIK cells likely rely on cluster of differentiation 8 (CD8) and its protein partner LCK proto-oncogene, Src family tyrosine kinase (LCK). A time-course series analysis revealed that CIK cells have relatively low immunogenicity because of decreased expression of some self-antigens. Importantly, we identified several crucial activating receptors and auxiliary adhesion receptors expressed on CIK cells that may function as tumor sensors. Interestingly, cytotoxicity-associated genes, including those encoding PRF1, GZMB, FASL, and several cytokines, were up-regulated in mature CIK cells. Most immune-checkpoint molecules and inflammatory tumor-promoting factors were down-regulated in the CIK cells, suggesting efficacy and safety in future clinical trials. Notably, insulin-like growth factor 1 (IGF-1) was highly expressed in CIK cells and may promote cytotoxicity, although it also could facilitate tumorigenesis. The transcriptomic atlas of CIK cells presented here may inform efforts to improve CIK-associated tumor cytotoxicity and safety in clinical trials.

Dynamic suspension culture improves ex vivo expansion of cytokine-induced killer cells by upregulating cell activation and glucose consumption rate

Ex vivo expansion is an effective strategy to acquire cytokine-induced killer (CIK) cells needed for clinical trials. In this work, the effects of dynamic suspension culture, which was carried out by shake flasks on a shaker, on CIK cells were investigated by the analysis of expansion characteristics and physiological functions, with the objective to optimize the culture conditions for ex vivo expansion of CIK cells. The results showed that the expansion folds of total cells in dynamic cultures reached 69.36 ± 30.36 folds on day 14, which were significantly higher than those in static cultures (9.24 ± 1.12 folds, P < 0.05), however, the proportions of CD3⁺ cells and CD3⁺CD56⁺ cells in both cultures were similar, leading to much higher expansion of CD3⁺ cells and CD3⁺CD56⁺ cells in dynamic cultures. Additionally, expanded CIK cells in two cultures possessed comparable physiological functions. Notably, significantly higher percentages of CD25⁺ cells and CD69⁺ cells were found in dynamic cultures (P <  0.05). Besides, much higher glucose consumption rate of cells (P <  0.05) but similar Y_Lac/gluc were observed in dynamic cultures. Further, cells in dynamic cultures had better glucose utilization efficiency. Together, these results suggested that dynamic cultures improved cell activation, then accelerated glucose consumption rate, which enhanced cell expansion and promoted glucose utilization efficiency of cells.

MicroRNA-374b inhibits liver cancer progression via down regulating programmed cell death-1 expression on cytokine-induced killer cells

Programmed cell death-1 (PD-1) is an oncogene associated with suppressing proliferation and cytokine production of T cells in the progression of liver cancer. microRNAs (miRs) regulate gene expression via specific binding to the target 3′untranslated region of mRNA. In the present study, miR-374b was indicated to interact with PD-1 and affect the tumor-targeting capacity of cytokine-induced killer (CIK) cells. miR-374b inhibitor significantly increased PD-1 expression in CIK cells. A synthetic small interfering (si)RNA targeting PD-1 was employed to silence the expression level of PD-1 in CIK cells. Then, the antitumor effect of siPD-1 in CIK cells was investigated. In vitro study demonstrated that IFN-γ secretion and the concentration of lactate dehydrogenase were significantly increased in the PD-1 knockdown group; however, the viability of HepG2 cells in the PD-1 knockdown group had significantly decreased, compared with the HepG2 cells in the negative control group. In vivo study indicated that mice inoculated with HepG2 cells and CIK cells with PD-1 knocked down had a significantly smaller tumor volume, compared with the control group. To conclude, human CIK cells transfected with siPD-1 can target liver cancer cells and enhance immunotherapy efficacy, and therefore they have potential in the immunotherapy of liver cancer.

Cytokine-Induced Killer Cells As Pharmacological Tools for Cancer Immunotherapy

Cytokine-induced killer (CIK) cells are a heterogeneous population of effector CD3⁺CD56⁺ natural killer T cells, which can be easily expanded in vitro from peripheral blood mononuclear cells. CIK cells work as pharmacological tools for cancer immunotherapy as they exhibit MHC-unrestricted, safe, and effective antitumor activity. Much effort has been made to improve CIK cells cytotoxicity and treatments of CIK cells combined with other antitumor therapies are applied. This review summarizes some strategies, including the combination of CIK with additional cytokines, dendritic cells, check point inhibitors, antibodies, chemotherapeutic agents, nanomedicines, and engineering CIK cells with a chimeric antigen receptor. Furthermore, we briefly sum up the clinical trials on CIK cells and compare the effect of clinical CIK therapy with other immunotherapies. Finally, further research is needed to clarify the pharmacological mechanism of CIK and provide evidence to formulate uniform culturing criteria for CIK expansion.

Dual Functional Capability of Dendritic Cells - Cytokine-Induced Killer Cells in Improving Side Effects of Colorectal Cancer Therapy

The aim of cancer therapy is to eradicate cancer without affecting healthy tissues. Current options available for treating colorectal cancer (CRC), including surgery, chemotherapy or radiotherapy, usually elicit multiple adverse effects and frequently fail to completely remove the tumor cells. Thus, there is a constant need for seeking cancer cell-specific therapeutics to improve the course of cancer therapy and reduce the risk of relapse. In this review we elaborate on the mechanisms underlying the immunotherapy with dendritic cells (DCs) and cytokine-induced killer (CIK) cells, and summarize their effectiveness and tolerability available clinical studies. Finally, we discuss the up-to-date combinatorial adoptive anti-cancer immunotherapy with CIK cells co-cultured with DCs that recently showed encouraging efficacy and usefulness in treating malignant disease, including CRC.

TACE combined with dendritic cells and cytokine-induced killer cells in the treatment of hepatocellular carcinoma: A meta-analysis

Patients with hepatocellular carcinoma (HCC), a fatal cancer, have benefited significantly from TACE (transcatheter arterial chemoembolization) and immunotherapy treatments. Immunotherapy that includes dendritic cells and cytokine-induced killer cells (DC-CIK) in combination with TACE has been extensively applied in cases of HCC. Few decisive conclusions about these combined effects on the outcomes of HCC patients have been reached. Therefore, the present meta-analysis was performed to compare the efficacy of the combined usage of DC-CIK with TACE with a TACE therapy alone on the outcomes of HCC patients. Participants were enrolled in eight eligible trials. The efficiency and safety of TACE followed by DC-CIK immunotherapy (experimental group) and of TACE alone (control group) were compared. The meta-analysis results demonstrated that TACE plus DC-CIK immunotherapy is possibly superior to TACE alone in promoting a better overall response, for half-year, 1-year, and 2-year overall survival (OS), median overall survival (OS) and progression-free survival rates (PFS) in HCC patients. Further studies should be performed to confirm the effect of the combined therapy.

Cytokine-induced killer cell therapy-associated idiopathic thrombocytopenic purpura: rare but noteworthy

Idiopathic thrombocytopenic purpura (ITP) is characterized by a diminished platelet count, an autoimmune condition with antibodies against platelets and an increased tendency to bleed. The association between ITP and solid tumors is uncommon. Cytokine-induced killer (CIK) cell therapy is a well tolerated and promising cancer treatment with minimal toxicity. For the first time, CIK cell therapy was reported to be followed by ITP. The mechanism through which CIK induces ITP remains unclear. Imbalanced ratio of Th cells, decreased numbers or impaired function of Treg cells and excessive secretion of cytokines inducing abnormal activation of B cells may be among the possible reasons. Therefore, a better understanding of this rare condition will require further investigation of these cases.

The combination of dendritic cells-cytotoxic T lymphocytes/cytokine-induced killer (DC-CTL/CIK) therapy exerts immune and clinical responses in patients with malignant tumors

BACKGROUND

The clinical trials using immunotherapy have been performed for the treatment of variety of malignant tumors. However, large-scale meta-analysis of combined DC-CTL/CIK therapy on immune and clinical response in patients has not been well studied yet. The purpose of this study is to investigate the role of DC-CTL/CIK therapy and evaluate the changes of immune indicators and tumor serological markers both at an individual level and at a system level, which is an important basis for immunotherapy as well as prognosis estimation.

METHODS

Three cohorts were designed to estimate therapeutic effects on patients with malignant tumors. Tumor serological markers were detected pre- and post-treatment by immunoradiometric methods using commercially available diagnostic kits. Lymphocyte subsets were identified by flow cytometry. The quality of life was assessed by EORTC QLQ-C30 questionnaire.

RESULTS

In this study, we found out that Tregs was significantly reduced after transfusion of DC-CTL/CIK cells companied by decreasing serological tumor markers including AFP, CA199 and CA242 in primary liver cancer and CA724 in gastric cancer. A system-level analysis showed that lower percentages of Tregs were detected in patients with long-lasting courses of immunotherapy. Strikingly, a tumor progression indicator, myeloid-derived suppressor cells (MDSC), was dramatically decreased in patients after DC-CTL/CIK treatment. These results suggested that DC-CTL/CIK therapy improves immune functions and the quality of life post-treatment versus pre-therapy, indicating that DC-CTL/CIK therapy might block the deterioration of invasive cancers in these patients.

CONCLUSIONS

This study demonstrated that DC-CTL/CIK therapy could reduce Tregs, MDSCs, and several crucial serological tumor markers in particular tumors, and improve the function of T cells immune systems and the quality of life in patients with malignant tumor.

Clinical effects of autologous dendritic cells combined with cytokine-induced killer cells followed by chemotherapy in treating patients with advanced colorectal cancer: a prospective study

The objective of this study was to evaluate the effects of dendritic cell and cytokine-induced killer (DC-CIK) cell-based immunotherapy combined with chemotherapy on the treatment of patients with advanced colorectal cancer. We prospectively included patients with advanced colorectal cancer and assessed the efficacy of DC-CIK cell-based immunotherapy combined with chemotherapy compared to treatment with chemotherapy alone. T cell subtypes, progression-free survival (PFS), overall survival (OS), and adverse events were evaluated in each group. In total, 134 patients were included in the DC-CIK group and 121 patients were included in the control group. No significant differences were observed in the percentages of CD3(+), CD3(+)CD4(+), CD3(+)CD8(+), and NK cells after DC-CIK cell-based immunotherapy compared to before chemotherapy in the DC-CIK group. The median PFS and OS in the DC-CIK treatment group were 8.8 months (95 % CI 8.4-9.1) and 14.7 months (95 % CI 13.9-15.5), respectively, which were significantly improved compared to the PFS and OS in the control group. The frequencies of grade III and IV leukopenia (8.2 vs. 19.0 %, P = 0.011), grade III and IV anemia (3.0 vs. 9.1 %, P = 0.039), and grade III and IV thrombocytopenia (3.7 vs. 10.7 %, P = 0.029) were significantly lower in the DC-CIK group compared to the control group. DC-CIK cell-based immunotherapy could induce an immune response against colorectal cancer and prolong PFS and OS. DC-CIK cell-based immunotherapy combined with chemotherapy had a significant benefit in terms of survival in patients with colorectal cancer compared to chemotherapy alone.

Revving up Natural Killer Cells and Cytokine-Induced Killer Cells Against Hematological Malignancies

Natural killer (NK) cells belong to innate immunity and exhibit cytolytic activity against infectious pathogens and tumor cells. NK-cell function is finely tuned by receptors that transduce inhibitory or activating signals, such as killer immunoglobulin-like receptors, NK Group 2 member D (NKG2D), NKG2A/CD94, NKp46, and others, and recognize both foreign and self-antigens expressed by NK-susceptible targets. Recent insights into NK-cell developmental intermediates have translated into a more accurate definition of culture conditions for the in vitro generation and propagation of human NK cells. In this respect, interleukin (IL)-15 and IL-21 are instrumental in driving NK-cell differentiation and maturation, and hold great promise for the design of optimal NK-cell culture protocols. Cytokine-induced killer (CIK) cells possess phenotypic and functional hallmarks of both T cells and NK cells. Similar to T cells, they express CD3 and are expandable in culture, while not requiring functional priming for in vivo activity, like NK cells. CIK cells may offer some advantages over other cell therapy products, including ease of in vitro propagation and no need for exogenous administration of IL-2 for in vivo priming. NK cells and CIK cells can be expanded using a variety of clinical-grade approaches, before their infusion into patients with cancer. Herein, we discuss GMP-compliant strategies to isolate and expand human NK and CIK cells for immunotherapy purposes, focusing on clinical trials of adoptive transfer to patients with hematological malignancies.

Comparative study of different procedures for the separation of peripheral blood mononuclear cells in cytokine-induced killer cell immunotherapy for hepatocarcinoma

Cytokine-induced killer (CIK) cell immunotherapy exhibits significant advantages in the clinical treatment of tumors. This study was designed to compare the biological characteristics of autologous CIK cells from patients with hepatocarcinoma following different procedures for the separation of peripheral blood mononuclear cells (PBMCs). Forty-four hepatocarcinoma patients were enrolled and distributed into two groups. PBMCs were isolated either using a blood cell separator (apheresis method) or Ficoll lymphocyte separation medium (Ficoll method). The total amount, collection efficacy, and cell status of PBMCs in the two groups were determined. According to the number and status of collected PBMCs, different cultivation procedures were used for their amplification and activation and the proliferation ability, phenotype, and killing activity of CIK cells in the two groups were evaluated. Our results indicated that the number of collected PBMCs in the apheresis group was far more than that in the Ficoll group. However, the isolation rate was lower, and more cellular debris was observed in the apheresis group, which may be the cause of some untoward effects. Following in vitro culture, the enrichment time of CIK cells was longer in the Ficoll group, and the percentages of CD3(+)CD4(+) (Th) and CD4(+)CD25(+) (Treg) cells were higher. In the apheresis group, the percentages of CD3(-)CD56(+) (NK) and CD3(+)CD56(+) (NKT) cells were higher, and the CIK cells exhibited a higher cytolytic activity against HepG2 hepatoma cells. In conclusion, different procedures for PBMCs separation can influence the biological activities of CIK cells, and the apheresis method is more effective at enhancing the antitumor efficacy of CIK cells. However, significant attention should be paid to the possibility of adverse reactions in apheresis donors.

MicroRNA profiling of CD3+ CD56+ cytokine-induced killer cells

Studies have proven that IL-2 and IL-15 showed contrasting roles during CIK cells preparation. By employing microarray, we analyzed miRNA expression profiles of PBMC, CIKIL-2 and CIKIL-15. Advanced bioinformatic analyses were performed to explore the key miRNAs which may regulate cell proliferation and anti-tumor activity of CIK. We identified 261 differentially expressed miRNAs (DEMs) between PBMC and CIKIL-2, and 249 DEMs between PBMC and CIKIL-15. MiR-143-3p/miR-145-5p was miRNA cluster which may positively regulate cell proliferation. In contrast, miR-340-5p/miR-340-3p cluster may negatively regulate cell proliferation via induction apoptosis, which may cause decreased cell proliferation capacity of CIKIL-2. MiRNA-target interaction analysis indicated that 10 co-downregulated miRNAs may synergistically turn on the expression of a pool of tumor cytotoxic genes in CIK cells. The DEMs between CIKIL-2 and CIKIL-15 may contribute to enhanced tumor cytotoxic capacity of CIKIL-2. Importantly, we found that repressed miR-193a-5p may regulate the expressions of inhibitory receptor KLRD1. The results of the validation assay have shown that KLRD1 were upregulated in CIK cells. Our findings have provided new insights into mechanisms of CIK cells production and tumor cytotoxic function, and shed light on their safety for clinical trial.

A killer choice for cancer immunotherapy

The promise of cell-based immunotherapies for the treatment of cancer offers the potential of therapeutic synergy with chemo- and radiotherapies that may overcome current limitations leading to durable responses and prevention of recurrence. There is a wide array of cell-based immunotherapies that are either poised to enter cancer clinical trials or are in clinical trials, and many are showing some success. Yet within this field, there are clear obstacles that need to be overcome, including limited access across tissue barriers, development of antigen tolerance, and the immunosuppressive microenvironment of tumors. Through an understanding of immune cell signaling and trafficking, immune cell populations can be selected for adoptive transfer, and delivery strategies can be developed that circumvent these obstacles to effectively direct populations of cells with robust anti-tumor efficacy to the target. Within the realm of immune cell therapies, cytokine-induced killer (CIK) cells have demonstrated promising trafficking patterns, effective delivery of synergistic therapeutics, and stand-alone efficacy. Here, we discuss the next generation of CIK therapies and their application for the effective treatment of a wide variety of cancers.

Adoptive immunotherapy of cytokine-induced killer cell therapy in the treatment of non-small cell lung cancer

AIM

The aim of this study was to systemically evaluate the therapeutic efficacy of cytokine-induced killer (CIK) cells for the treatment of non-small cell lung cancer.

MATERIALS AND METHODS

A computerized search of randomized controlled trials for CIK cell-based therapy was performed. The overall survival, clinical response rate, immunological assessment and side effects were evaluated.

RESULTS

Overall, 17 randomized controlled trials of non-small cell lung cancer (NSCLC) with a total of 1172 patients were included in the present analysis. Our study showed that the CIK cell therapy significantly improved the objective response rate and overall survival compared to the non-CIK cell-treated group. After CIK combined therapy, we observed substantially increased percentages of CD3+, CD4+, CD4+CD8+, CD3+CD56+ and NK cells, whereas significant decreases were noted in the percentage of CD8+ and regulatory T cell (Treg) subgroups. A significant increase in Ag-NORs was observed in the CIK-treated patient group (p = 0.00001), whereas carcinoembryonic antigen (CEA) was more likely to be reduced to a normal level after CIK treatment (p = 0.0008). Of the possible major side effects, only the incidence of fever in the CIK group was significantly higher compared to the group that received chemotherapy alone.

CONCLUSION

The CIK cell combined therapy demonstrated significant superiority in the overall survival, clinical response rate, and T lymphocytes responses and did not present any evidence of major adverse events in patients with NSCLC.

Human leukocyte antigen-haploidentical donor-derived cytokine-induced killer cells are safe and prolong the survival of patients with advanced non-small cell lung cancer

The aim of the present study was to evaluate the safety and efficacy of administering cytokine-induced killer cells (termed allogeneic CIKs), obtained from the blood of the offspring of patients, for the treatment of non-small cell lung cancer. Symptoms, signs and laboratory assessment results for 303 cancer patients were collected prior to and following treatment with autologous or allogeneic CIKs. In addition, 54 patients with advanced non-small cell lung cancer (NSCLC) were enrolled and divided into allogeneic CIK and optimal support groups (n=27 per group) according to gender, age, Karnofsky performance status score, TNM stage and histological type. In addition, overall survival (OS) was compared between the two groups. A total of 303 patients were treated with CIKs for 647 cycles, with 308 and 339 cycles in the autologous and allogeneic CIK groups, respectively. The mean number of CIKs in the autologous and allogeneic groups was 2.11±0.32×10¹⁰ and 2.29±0.36×10¹⁰, respectively, with no marked differences identified between the two groups (t=1.147; P>0.05). The predominant adverse events included insomnia, fever, nausea, vomiting and mild abdominal pain, which were found, respectively, in nine (6.8%), eight (6.0%), two (1.5%) and one (0.8%) patients receiving autologous CIKs and 11 (6.5%), 10 (5.9%), one (0.6%) and one (0.6%) patients receiving allogeneic CIKs, with no marked differences identified between the two groups (P>0.05). Adverse events were not associated with cell count, frequency or duration of treatment. Following CIK treatment, the outcomes of routine blood tests, and liver and kidney function tests, as well as immune function and electrocardiogram examinations remained unchanged (P>0.05). The median OS was 11.0 months (95% confidence interval (CI), 8.6–13.4 months) and 8.0 months (95% CI, 5.3–10.7 months) for NSCLC patients receiving allogeneic CIKs and optimal support, respectively; a statistically significant difference was identified (χ²=5.618; P=0.018). The present study demonstrated that CIKs from human leukocyte antigen haploidentical donors are safe and prolong the survival of NSCLC patients.

Treatment of multiple solitary plasmacytomas with cytokine-induced killer cells

BACKGROUND AIMS

Currently available treatment methods for advanced plasmacytoma include surgery, chemotherapy, radiotherapy, immunomodulatory agents, hematopoietic stem cell transplantation and donor lymphocyte infusion. We report a case of advanced refractory multiple solitary plasmacytomas in a 68-year-old Asian man with multiple bone lesions, in whom autologous cytokine-induced killer (CIK) cells were administered in an effort to eliminate residual tumor lesions.

METHODS

CIK cells were infused monthly for 21 courses.

RESULTS

The patient has survived 63 months since the first hospital visit without disease progression for 40 months.

CONCLUSIONS

This case represents the first report of autologous CIK cell immunotherapy used successfully to suppress multiple solitary plasmacytomas and resolve bone lesions.

Retrospective comparative study of the effects of dendritic cell vaccine and cytokine-induced killer cell immunotherapy with that of chemotherapy alone and in combination for colorectal cancer

Purpose. This retrospective study determined the delayed-type hypersensitivity (DTH) skin test and safety of dendritic cell (DC) vaccine and cytokine-induced killer (CIK) cell immunotherapy and the survival compared to chemotherapy in 239 colorectal cancer (CRC) patients. Methods. DTH and safety of the immunotherapy were recorded. The overall survival (OS) and disease free survival curves were compared according to the immunotherapy and/or chemotherapy received with Kaplan-Meier estimates. Results. Of the 70 patients who received immunotherapy, 62.86% had a positive DTH skin test, 38.57% developed fever, 47.14% developed insomnia, 38.57% developed anorexia, 4.29% developed joint soreness, and 11.43% developed skin rash. For 204 resectable CRC patients, median survival time (MST) (198.00 days) was significantly longer in patients with immunotherapy plus chemotherapy than with chemotherapy alone (106.00 days) (P = 0.02). For 35 patients with unresectable or postsurgery relapsed CRC and who were confirmed to be dead, no statistical difference was observed in the MST between the patients treated with immunotherapy and with chemotherapy (P = 0.41). MST in the patients treated with chemotherapy plus immunotherapy was 154 days longer than that of patients treated with chemotherapy alone (P = 0.41). Conclusions. DC vaccination and CIK immunotherapy did not cause severe adverse effects, induce immune response against CRC, and prolong OS.

Evaluation of tumor response to cytokine-induced killer cells therapy in malignant solid tumors

CIK cells therapy has been evaluated as an adoptive cell immunotherapy for cancer patients, but there still have not been any standardized systems for evaluating the antitumor efficacy yet. The WHO and RECIST criteria have already been established for a few years but not sufficient to fully characterize the activity of immunotherapy. Based on these two criteria, the irRC was proposed for evaluating the efficacy of immunotherapy. A variety of bioassays for immune monitoring including the specific and non-specific methods, have been established. We recommend detect levels of various immunocytes, immune molecules and soluble molecules to find the correlations among them and clinicopathological characteristics to establish criteria for immunological classification. We also recommend a paradigm shift for the oncologists in the evaluation of immune therapies to ensure assessment of activity based on clinically relevant criteria and time points.

Modification of chemokine receptor expression to enhance levels of trafficking receptors on autologous cytokine-induced killer cells derived from patients with colorectal cancer

Cytokine-induced killer (CIK) cells have achieved therapeutic benefit in treatment of solid tumors in clinic. However, some patients show no response after CIK treatment. Animal assays have shown that successful infiltration of CIK cells to the tumor sites could affect the outcome. Chemokines play important roles in lymphocyte trafficking. Understanding the molecular mechanism of chemokines in the process of CIK cell homing is important for further modification of CIK therapy. In this study, we investigated the spectrum of chemokine ligands in the colorectal cancer sites and observed that chemokine ligands CCL20 and CXCL10 were overexpressed in the CRC tumor tissues compared with adjacent tissues. Although the corresponding receptors CCR6 and CXCR3 increased on CIK cells compared with PBMCs, their expression on CIK cells derived from CRC patients had lower levels than healthy donors, which might be a limited factor for autologous-CIK cells trafficking to tumor site. Importantly, stimulation with chemokines CCL20 and CXCL10 promotes the expression levels of CCR6 and CXCR3 on CIK cells, thus augmenting the relative migration of CIK cells in vitro. Our results suggest that modification of surface chemokine receptors may enhance the homing ability of CIK cells for better therapeutic achievements.

Shikonin induces cytotoxicity of co-stimulated human cells to gastric cancer cell lines

AIM: To observe the effect of shikonin on the growth of co-stimulated human cells and the cytotoxicity of co-stimulated cells to gastric cancer cell lines NCI-N87, BGC-823 and HGC-27, and to explore the underlying mechanisms．

METHODS: Peripheral blood mononuclear cells were separated form healthy volunteers and induced with various cytokines (CD3 mAb, IL-2, IFN-γ, IL-1α, CD28 mAb, IL-15 and IL-21) to result in co-stimulated human cells in vitro. After co-stimulated cells were incubated with shikonin of different concentrations for 24, 48 and 72 h and co-cultured with the three gastric cancer cell lines, CCK8 assay was used to assess the proliferation of co-stimulated cells, and MTT assay was used to measure the reduced rate of growth of gastric cancer cells. FCM was used to detect the expression of GraB, PFP, CD107a and IFN-γ on co-stimulated cells before and after shikonin treatment. LDH release assay was used to measure the influence of shikonin on cytotoxic activity of co-stimulated cells to gastric cancer cells. Western blot assay was used to measure β-catenin, P-ERK1/2, Bcl-2 and P-AKT expression in co-stimulated cells before and after shikonin induction.

RESULTS: After incubation with shikonin at concentrations ranging from 0.2 to 50 μg/L for 48 h, the proliferation rate of co-stimulated cells increased significantly (P < 0.05). The expression of GraB, PFP, CD107a, IFN-γ, β-catenin, P-ERK1/2, Bcl-2 and P-AKT on co-stimulated cells treated with shikonin at concentrations from 6 to 25 μg/L were significantly higher than that in the control group (P < 005). In addition, the cytotoxic activity of co-stimulated cells treated with shikonin against the three gastric cancer cell lines were significantly higher than that in the control group (P < 0.05).

CONCLUSION: These results suggest that shikonin can promote the growth of co-stimulated cells and increase the cytotoxic activity of co-stimulated cells against gastric cancer cells via mechanisms possibly associated with enhancing the activity of β-catenin, P-ERK1/2, Bcl-2 and P-AKT expression and increasing the expression of PFP, GraB, CD107a and IFN-γ.

The CIK cells stimulated with combination of IL-2 and IL-15 provide an improved cytotoxic capacity against human lung adenocarcinoma

Generation of cytokine-induced killer (CIK) cells is an emerging approach in adoptive donor lymphocyte infusion for patients with a wide range of tumors. However, our previous in vitro studies have shown that the killing efficacy of CIK cells against lung cancer was lower than other tumor cells, while the underlying mechanisms are not clear. We explored the feasibility to improve CIK cells mediated cytotoxicity against lung cancer. Interleukin (IL)-15 is a pleiotropic cytokine that stimulates cytolytic activity and cytokine secretion of NK cells, which may enhance the cytotoxic activity of CIK cells. In this study, we intended to stimulate the CIK cells by IL-2 in combination with IL-15 in cell expansion to achieve enhanced cytotoxicity against lung cancer cells. The different phenotypes of IL-2 or combination of IL-2 and IL-15 stimulated cytokine-induced killer cells were determined, and the improved cytotoxicity of IL-2 and IL-15 induced CIK cells against lung adenocarcinoma were evaluated both in vitro and in vivo. CIK cells stimulated with both IL-2 and IL-15 has shown greater proliferative potential than CIK cells treated with IL-2 alone. IL-15 induction also has driven the expansion of CD3+CD56+ subset and significantly enhanced cytotoxicity against tumor cells. Further analysis has demonstrated that CIKIL-2&IL-15 injected mice models have shown significant tumor regression and lower expression level of CyclinD1 in tumor tissue. This study has provided preclinical evidences that CIKIL-2&IL-15 with enhanced cytotoxicity may offer alternative treatment option for patients with lung cancer.

Cytokine-induced killer cells promote antitumor immunity

The number of immune cells, especially dendritic cells and cytotoxic tumor infiltrating lymphocytes (TIL), particularly Th1 cells, CD8 T cells, and NK cells is associated with increased survival of cancer patients. Such antitumor cellular immune responses can be greatly enhanced by adoptive transfer of activated type 1 lymphocytes. Recently, adoptive cell therapy based on infusion of ex vivo expanded TILs has achieved substantial clinical success. Cytokine-induced killer (CIK) cells are a heterogeneous population of effector CD8 T cells with diverse TCR specificities, possessing non-MHC-restricted cytolytic activities against tumor cells. Preclinical studies of CIK cells in murine tumor models demonstrate significant antitumor effects against a number of hematopoietic and solid tumors. Clinical studies have confirmed benefit and safety of CIK cell-based therapy for patients with comparable malignancies. Enhancing the potency and specificity of CIK therapy via immunological and genetic engineering approaches and identifying robust biomarkers of response will significantly improve this therapy.

Enhancing cytokine-induced killer cell therapy of multiple myeloma

Cytokine-induced killer (CIK) cells are in clinical testing against various tumor types, including multiple myeloma. In this study, we show that CIK cells have activity against subcutaneous and disseminated models of human myeloma (KAS-6/1), which can be enhanced by infecting the CIK cells with an oncolytic measles virus (MV) or by pretreating the myeloma cells with ionizing radiation (XRT). KAS-6/1 cells were killed by coculture with CIK or MV-infected CIK (CIK/MV) cells, and the addition of an anti-NKG2D antibody inhibited cytolysis by 50%. However, human bone marrow stromal cells can reduce CIK and CIK/MV mediated killing of myeloma cells (RPMI 8226, JJN-3 and MM1). In vivo, CIK and CIK/MV prolonged the survival of mice with systemic myeloma, although CIK/MV showed enhanced antitumor activity compared with CIK. Irradiation of the KAS-6/1 cells induced mRNA and protein expression of NKG2D ligands, MICA, and MICB in a dose-dependent manner and enhanced delivery of CIK/MV to the irradiated tumors. In both subcutaneous and disseminated myeloma models, XRT at 2 Gy resulted in superior prolongation of the survival of mice given CIK/MV therapy compared with CIK/MV with no XRT. This study demonstrates the potential of CIK against myeloma and that the combination of virotherapy with radiation could be used to further enhance therapeutic outcome using CIK cells.