We investigate the unknown tumor-killing activity of cytokine-induced killer (CIK) cells against autologous metastatic melanoma and the elusive subset of putative cancer stem cells (mCSC).
We ...developed a preclinical autologous model using same patient-generated CIK cells and tumor targets to consider the unique biology of each patient/tumor pairing. In primary tumor cell cultures, we visualized and immunophenotypically defined a putative mCSC subset using a novel gene transfer strategy that exploited their exclusive ability to activate the promoter of stemness gene Oct4.
The CIK cells from 10 patients with metastatic melanoma were successfully expanded (median, 23-fold; range, 11-117). Primary tumor cell cultures established and characterized from the same patients were used as autologous targets. Patient-derived CIK cells efficiently killed autologous metastatic melanoma up to 71% specific killing (n = 26). CIK cells were active in vivo against autologous melanoma, resulting in delayed tumor growth, increased necrotic areas, and lymphocyte infiltration at tumor sites. The metastatic melanoma cultures presented an average of 11.5% ± 2.5% putative mCSCs, which was assessed by Oct4 promoter activity and stemness marker expression (Oct4, ABCG2, ALDH, MITF). Expression was confirmed on mCSC target molecules recognized by CIK cells (MIC A/B; ULBPs). CIK tumor killing activity against mCSCs was intense (up to 71%, n = 4) and comparable with results reported against differentiated metastatic melanoma cells (P = 0.8).
For the first time, the intense killing activity of CIK cells against autologous metastatic melanoma, including mCSCs, has been shown. These findings move clinical investigation of a new immunotherapy for metastatic melanoma, including mCSCs, closer.
Summary
Cytokine‐induced killer lymphocytes (CIK) are a promising alternative to conventional donor lymphocyte infusion (DLI), following allogeneic haematopoietic cell transplantation (HCT), due to ...their intrinsic anti‐tumour activity and reduced risk of graft‐versus‐host disease (GVHD). We explored the feasibility, anti‐leukaemic activity and alloreactive risk of CIK generated from full‐donor chimaeric (fc) patients and genetically redirected by a chimeric antigen receptor (CAR) (fcCAR.CIK) against the leukaemic target CD44v6. fcCAR.CIK were successfully ex‐vivo expanded from leukaemic patients in complete remission after HCT confirming their intense preclinical anti‐leukaemic activity without enhancing the alloreactivity across human leukocyte antigen (HLA) barriers. Our study provides translational bases to support clinical studies with fcCAR.CIK, a sort of biological bridge between the autologous and allogeneic sources, as alternative DLI following HCT.
Antibodies against the lymphocyte PD-1 (aPD-1) receptor are cornerstone agents for advanced non-small cell lung cancer (NSCLC), based on their ability to restore the exhausted antitumor immune ...response. Our study reports a novel, lymphocyte-independent, therapeutic activity of aPD-1 against NSCLC, blocking the tumor-intrinsic PD-1 receptors on chemoresistant cells.
PD-1 in NSCLC cells was explored in vitro at baseline, including stem-like pneumospheres, and following treatment with cisplatin both at transcriptional and protein levels. PD-1 signaling and RNA sequencing were assessed. The lymphocyte-independent antitumor activity of aPD-1 was explored in vitro, by PD-1 blockade and stimulation with soluble ligand (PD-L1s), and in vivo within NSCLC xenograft models.
We showed the existence of PD-1+ NSCLC cell subsets in cell lines and large in silico datasets (Cancer Cell Line Encyclopedia and The Cancer Genome Atlas). Cisplatin significantly increased PD-1 expression on chemo-surviving NSCLC cells (2.5-fold P = 0.0014), while the sequential treatment with anti-PD-1 Ab impaired their recovery after chemotherapy. PD-1 was found to be associated with tumor stemness features. PD-1 expression was enhanced in NSCLC stem-like pneumospheres (P < 0.0001), significantly promoted by stimulation with soluble PD-L1 (+27% ± 4, P < 0.0001) and inhibited by PD-1 blockade (-30% ± 3, P < 0.0001). The intravenous monotherapy with anti-PD-1 significantly inhibited tumor growth of NSCLC xenografts in immunodeficient mice, without the contribution of the immune system, and delayed the occurrence of chemoresistance when combined with cisplatin.
We report first evidence of a novel lymphocyte-independent activity of anti-PD-1 antibodies in NSCLC, capable of inhibiting chemo-surviving NSCLC cells and exploitable to contrast disease relapses following chemotherapy. See related commentary by Augustin et al., p. 505.
Interferons (IFNs) play a key role in modulating anti-microbial and antitumor immune responses. In oncology, past attempts to exploit IFNs therapeutically did not fulfill expectations, and had only ...modest clinical results, mostly limited to adjuvant melanoma treatment. The recent successes of immunotherapy in oncology have brought new attention to the potential of immune-modulatory agents like the IFNs. Areas covered: The authors review the biological effects of IFN on melanoma and immune cells. Then, the authors summarize the clinical results of adjuvant and therapeutic IFN in melanoma, giving focus to possible prognostic factors and new on-going clinical trials. Expert opinion: IFNs offer intriguing opportunities for synergism between conventional treatments and recently introduced molecular-targeted and immunotherapy approaches. However, the full comprehension of all IFN effects and their multiple biologic links is challenging. A strong commitment toward parallel translational research is needed to facilitate the interpretation of IFN's expected and unexpected effects, guiding the rational design of informative clinical studies.
The good outcome of hematopoietic stem cell (HSC) transplantation is hampered by low doses of CD34+ cell infusion. Transplanted HSCs undergo a replicative stress that causes accelerated senescence ...due to rapid telomere shortening. The expansion of human cord blood HSCs is instrumental in obtaining a large number of "good quality" cells, in terms of telomere length and telomerase activity compared to adult HSCs.
Fluoropyrimidines (FP) are the backbone chemotherapy in colorectal cancer (CRC) treatment; however, their use is associated with cardiotoxicity, which is underreported. In the present study, it was ...aimed to prospectively determine the incidence rates and related risk factors of FP‑induced cardiotoxicity (FIC) in CRC patients and at identifying predictive biomarkers. A total of 129 consecutive previously untreated CRC patients underwent active cardiological monitoring, including 5‑items simplified questionnaire on symptoms, electrocardiogram (ECG) and plasma sample collection during FP chemotherapy. FIC was defined as the presence of ECG alterations and/or the arising of at least one symptom of chest pain, dyspnoea, palpitations or syncope. The primary objective was the evaluation of FIC incidence. Secondary objectives were the correlation of FIC with well‑known cardiological risk factors and the identification of circulating biomarkers (serum levels of troponin I, pro hormone BNP; miRNA analysis) as predictors of FIC. A total of 20 out of 129 (15.5%) patients experienced FIC. The most common symptoms were dyspnoea (60%) and chest pain (40%), while only 15% of patients presented ECG alterations, including one acute myocardial infarction. Retreatment with FP was attempted in 90% of patients with a favourable outcome. Despite 48% of patients having cardiological comorbidities, an increased FIC was not observed in this subgroup. Only the subgroup of females with the habit of alcohol consumption showed an increased risk of FIC. None of the circulating biomarkers evaluated demonstrated a clinical utility as FIC predictors. FIC can be an unexpected, life‑threatening adverse event that can limit the subsequent treatment choices in patients with CRC. In this prospective study, well‑known cardiological comorbidities were not related to higher FIC risk and circulating biomarkers predictive of toxicity could not be found. With careful monitoring, mainly based on symptoms, almost all patients completed the FP treatment.
Cytokine-induced killer (CIK) cells consist of a heterogeneous population of polyclonal T lymphocytes displaying NK phenotype and HLA-unrestricted cytotoxic activity against a broad range of tumors. ...We sought to determine whether transduction of CIK cells with T cell receptor (TCR) genes specific for tumor-associated antigens could generate effector cells endowed with a double mechanism of tumor recognition. HLA-A2-restricted TCR-transduced (TD) CIK directed against the melanoma antigens Mart1 and NY-ESO1 were generated by lentiviral transduction and successfully expanded over a 3-4-week period. TD-CIK cells were both CD3(+)/CD56(-) and CD3(+)/CD56(+) (31±8% and 59±9%, respectively), indicating that both major histocompatibility complex (MHC)-restricted T cells and MHC-unrestricted CIK could be targeted by lentiviral transduction. At the end of the culture, the majority of both unmodified and TD-CIK displayed an effector memory phenotype, without considerable expression of replicative senescence and exhaustion markers. Functionally, TD-CIK specifically recognized tumor cells expressing the relevant antigen as well as maintained their MHC-unrestricted tumor activity. The cytotoxic activity of TD-CIK against HLA-A2(+) melanoma cell lines was significantly higher than the untransduced counterparts at a low effector:target ratio (cytotoxic activity of TD-CIK was from 1.9- to 4.3-fold higher than untransduced counterparts). TD-CIK were highly proficient in releasing high amount of IFN-γ upon antigen-specific stimulation and were able to recognize primary melanoma targets. In conclusion, we showed that (1) the reproducibility and simplicity of CIK transduction and expansion might solve the problem of obtaining adequate numbers of potent antitumor effector cells for adoptive immunotherapy; (2) the presence of both terminal effectors as well as of less differentiated progenitors might confer them long survival in vivo; and (3) the addition of an MHC-restricted antigen recognition allows not only targeting tumor surface antigens but also a wider range of cytoplasmic or nuclear antigens, involved in tumor proliferation and survival. TD-CIK cells with a double mechanism of tumor recognition are an attractive and alternative tool for the development of efficient cell therapeutic strategies.
Cytokine-induced killer (CIK) cells are ex vivo expanded T lymphocytes endowed with potent MHC-independent antitumor activity. CIK cells are emerging as promising therapeutic approach in the field of ...cancer adoptive immunotherapy, with biologic features favoring their transferability into clinical applications. Aim of this review is to present the biologic characteristic of CIK cells, discussing the main preclinical findings and initial clinical applications in the field of solid tumors.
Conventional chemotherapies seemed to have reached a therapeutic plateau in the treatment of solid tumors and many metastatic diseases are still incurable. Events of chemo-resistance and relapses ...appear to be sustained by a subset of putative cancer stem cells (CSCs). New anticancer strategies need to face this new challenge exploring their efficacy against CSCs. Immunotherapy has raised enthusiasms in cancer therapy and its potential against CSCs is an intriguing field of research.
In this work we reviewed the immunotherapy approaches directed against CSCs in solid tumors. We schematically divided adaptive immunotherapy strategies, mainly based on dendritic cell-vaccination, and strategies exploiting MHC-unrestricted effectors like natural killer cells, γδ T lymphocytes and cytokine-induced killer cells. Findings, strength and limitations of these models are discussed and compared highlighting their potential clinical relevance.
The important biologic role and clinical relevance of CSCs introduced a 'noble target' for immunotherapy and cancer treatments in general. Initial evidences suggest that CSCs may be susceptible to various types of immunotherapy attacks, overcoming their chemo-resistance. Investigation of important safety issues, based on shared features with 'normal' stem cells, along with intriguing synergisms with modulatory agents are open challenges for the next future and effective clinical translation.
