Effects of Autologous Cytokine-Induced Killer Cells Infusion in Colorectal Cancer Patients: A Prospective Study

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.

Cytokine-induced killer cells mediated pathways in the treatment of colorectal cancer

Cytokine-induced killer (CIK) cell therapy is a type of adoptive immunotherapy that due to its high proliferation rate and anti-tumor characteristics, is being investigated to treat various solid tumors. Since advanced colorectal cancer (CRC) has high mortality and poor survival rates, and the efficacy of chemotherapy and radiotherapy is limited in treatment, the application of CIK cell therapy in CRC has been evaluated in numerous studies. This review aims to summarize the clinical studies that investigated the safety and clinical efficacy of CIK cell therapy in CRC. Therefore, 1,969 enrolled CRC patients in the clinical trials, of which 842 patients received CIK cells in combination with chemotherapy with or without dendritic cell (DC) infusions, were included in the present review. Furthermore, the signaling pathways involved in CIK cell therapy and novel methods for improving migration abilities are discussed.

Retrospective analysis of the efficacy of adjuvant cytokine‐induced killer cell immunotherapy combined with chemotherapy in colorectal cancer patients after surgery

Objectives

Even though postoperative chemotherapy can eliminate residual tumor cells in patients with colorectal cancer (CRC), severe adversity, weakened immunity and drug resistance are still problems. Adjuvant cytokine‐induced killer (CIK) cell therapy is an alternative to CRC patients after surgery. The present study investigated the efficacy of adjuvant CIK cell therapy combined with chemotherapy in postoperative CRC patients.

Methods

This retrospective analysis included 137 postoperative CRC patients, including 71 who received adjuvant chemotherapy alone (control group) and 66 who received adjuvant immunotherapy based on CIK cells combined with chemotherapy (CIT group).

Results

Long‐term follow‐up study indicated that overall survival (OS) and progression‐free survival (PFS) were significantly longer in the CIT group than in the control group. Subgroup analyses showed that CIT treatment significantly improved OS and PFS of CRC patients classified as stage II and N0 stage and in patients with primary tumors in the rectum. Increasing the number of CIK infusions resulted in better prognosis. CRC patients aged < 65 years were found to benefit more from CIT‐based therapy than patients aged ≥ 65 years. A retrospective case–control study indicated that the primary tumor expression of signalling lymphocytes activating molecule family 7 (SLAMF7) was associated with increased efficacy of CIT treatment.

Conclusions

Adjuvant CIT therapy was an effective therapeutic strategy for postoperative CRC patients prolonging OS and PFS. Patient age, tumor stage and expression of SLAMF7 may be potential indicators of the efficacy of CIT therapy.

Application of the chemokine-chemokine receptor axis increases the tumor-targeted migration ability of cytokine-induced killer cells in patients with colorectal cancer

Cytokine-induced killer (CIK) cells are a group of heterogeneous immune cells which can be isolated from human peripheral blood mononuclear cells and have demonstrated therapeutic benefit both in hematologic malignancies and solid tumors, including colorectal cancer. However, poor tumor-targeted migration has limited the clinical efficacy of CIK cell treatment. The chemokine-chemokine receptor (CK-CKR) axis serves a role in the tumor-directed trafficking capacity of immune cells. Investigating the relationship between CKR profiles on the surface of CIK cells and chemokine expression levels in the tumor microenvironment may improve CIK cell therapy. In the present study, the spectrum of chemokine expression levels in tumor tissues from patients with colorectal cancer (CRC) and CKR expression profiles in CIK cells obtained from the same individuals with CRC were investigated. The results showed that chemokine expression levels in tumor tissues exhibited variability and cell line heterogeneity. However, the expression levels of a number of chemokines were similar in different CRC donors and cell lines. Expression levels of CXCLL10, CXCL11 and CCL3 were significantly higher in most tumor tissues compared with adjacent normal tissues and highly expressed in most CRC cell lines. In accordance with chemokine expression levels, CKR profiles on the surface of CIK cells also showed donor-to-donor variability. However, concordant expression profiles of CKRs were identified in different patients with CRC. CXCR3 and CXCR4 were highly expressed on the surface of CIK cells through the culture process. Importantly, the expression levels of all CKRs, especially CCR4, CXCR4 and CXCR3, were notably decreased during the course of CIK cell expansion. The changing trend of CKR profiles were not correlated with the chemokine expression profiles in CRC tissues (CCL3, CXCL12 and CXCL10/CXCL11 were highly expressed in CRC tissue). Re-stimulating CIK cells using chemokines (CCL21 and CXCL11) at the proper time point increased corresponding CKR expression levels on the surface of CIK cells and enhance tumor-targeted trafficking in vitro. These results demonstrated that modification of the CK-CKR axis using exogenous recombinant chemokines at the proper time point enhanced CIK cell trafficking ability and improved CIK antitumor effects.

Cytokine-induced killer cell/dendritic cell combined with cytokine-induced killer cell immunotherapy for treating advanced gastrointestinal cancer

Background

This study aimed to investigate the efficacy and safety of cytokine-induced killer (CIK)/dendritic cell combined with CIK (DC–CIK) cell therapy in advanced gastrointestinal cancer (GIC).

Methods

The PubMed, Cochrane library, and Embase were searched to conduct a meta-analysis of clinical controlled trials to evaluate the efficacy and safety of CIK/DC–CIK cell therapy in advanced GIC. The pooled risk ratios (RRs) or weighted mean difference (WMD) with 95% confidence intervals (95% CIs) were calculated.

Results

A total of nine studies with 1113 patients were identified. The overall survival (RR = 1.84, 95% CI = 1.41–2.40, P_{heterogeneity} = 0.654, I² = 0%), progression-free survival (RR = 1.99, 95% CI = 1.52–2.60, P_{heterogeneity} = 0.727, I² = 0%), and quality of life (WMD = 16.09, 95% CI = 1.66–30.52, P_{heterogeneity} < 0.001, I² = 98.8%) were significantly improved in patients who received chemotherapy combined with CIK/DC–CIK cells, and no severe adverse events were reported.

Conclusion

This meta-analysis suggested that the combination of CIK/DC–CIK immunotherapy and chemotherapy was safe and applicable for patients with advanced GIC. It is a feasible choice to prolong survival and improve quality of life.

Predictive significance of T cell subset changes during ex vivo generation of adoptive cellular therapy products for the treatment of advanced non-small cell lung cancer

Adoptive T cell immunotherapy with cytokine-induced killer cells (CIKs) has been demonstrated to prolong the survival of patients with advanced non-small cell lung cancer (NSCLC). The aim of the present study was to evaluate whether the expansion of effector T cells and the decrease of regulatory T cells (Tregs) that occurred during the ex vivo generation of DC-CIKs were associated with improved clinical outcome in patients who received treatment. CIKs were generated ex vivo over a 28-day period from the peripheral blood apheresis product of 163 patients with advanced cancer (including 30 with NSCLC). CIKs were also generated from an additional cohort of 65 patients with NSCLC over a 15-day period. The progression-free survival (PFS) and overall survival (OS) time of patients treated with CIKs was determined by reviewing the patients' medical records. The number of CIKs gradually increased during the culture period and peaked at day 15, followed by a slight decline until day 28. Similarly, the percentages of T cell subtypes associated with anti-tumor activity (CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺ and CD8⁺CD28⁺) peaked at day 15. Although the percentage of CD4⁺CD25⁺CD127⁺ Tregs increased by day 7, a decrease was subsequently observed. Among the 95 patients with NSCLC, those with a post/pre-culture ratio of CD8⁺CD28⁺ T lymphocytes >2.2 had significantly better PFS and OS compared with those with ratios ≤2.2. Those with a post/pre-culture CD4⁺CD25⁺CD127⁺ Treg ratio ≤0.6 had significantly better OS and PFS compared with those with ratios >0.6. The peak expansion of CIKs from peripheral blood mononuclear cells occurred at day 15 of ex vivo culture. PFS and OS were associated with post/pre-culture CD8⁺CD28⁺ T lymphocyte ratio >2.2 and post/pre-culture CD4⁺CD25⁺CD127⁺ Treg ratio <0.6 in the CIKs of patients with advanced NSCLC treated with adoptive T cell immunotherapy. Further efforts are underway to optimize the DC-CIK infusion for cancer immunotherapy.