Transgene-derived overexpression of miR-17-92 in CD8+ T-cells confers enhanced cytotoxic activity

INT-1B3, an LNP formulated miR-193a-3p mimic, promotes anti-tumor immunity by enhancing T cell mediated immune responses via modulation of the tumor microenvironment and induction of immunogenic cell death

microRNAs (miRNAs) are small, non-coding RNAs that regulate expression of multiple genes. MiR-193a-3p functions as a tumor suppressor in many cancer types, but its effect on inducing specific anti-tumor immune responses is unclear. Therefore, we examined the effect of our lipid nanoparticle (LNP) formulated, chemically modified, synthetic miR-193a-3p mimic (INT-1B3) on anti-tumor immunity. INT-1B3 inhibited distant tumor metastasis and significantly prolonged survival. INT-1B3-treated animals were fully protected against challenge with autologous tumor cells even in absence of treatment indicating long-term immunization. Protection against autologous tumor cell challenge was hampered upon T cell depletion and adoptive T cell transfer abrogated tumor growth. Transfection of tumor cells with our miR-193a-3p mimic (1B3) resulted in tumor cell death and apoptosis accompanied by increased expression of DAMPs. Co-culture of 1B3-transfected tumor cells and immature DC led to DC maturation and these mature DC were able to stimulate production of type 1 cytokines by CD4+ and CD8+ T cells. CD4-CD8- T cells also produced type 1 cytokines, even in response to 1B3-transfected tumor cells directly. Live cell imaging demonstrated PBMC-mediated cytotoxicity against 1B3-transfected tumor cells. These data demonstrate for the first time that miR-193a-3p induces long-term immunity against tumor development via modulation of the tumor microenvironment and induction of immunogenic cell death.

Identification of extracellular vesicle microRNA signatures specifically linked to inflammatory and metabolic mechanisms in obesity-associated low type-2 asthma

RATIONALE AND OBJECTIVE

Plasma extracellular vesicles (EVs) represent a vital source of molecular information about health and disease states. Due to their heterogenous cellular sources, EVs and their cargo may predict specific pathomechanisms behind disease phenotypes. Here we aimed to utilize EV microRNA (miRNA) signatures to gain new insights into underlying molecular mechanisms of obesity-associated low type-2 asthma.

METHODS

Obese low type-2 asthma (OA) and non-obese low type-2 asthma (NOA) patients were selected from an asthma cohort conjointly with healthy controls. Plasma EVs were isolated and characterised by nanoparticle tracking analysis. EV-associated small RNAs were extracted, sequenced and bioinformatically analysed.

RESULTS

Based on EV miRNA expression profiles, a clear distinction between the three study groups could be established using a principal component analysis. Integrative pathway analysis of potential target genes of the differentially expressed miRNAs revealed inflammatory cytokines (e.g., interleukin-6, transforming growth factor-beta, interferons) and metabolic factors (e.g., insulin, leptin) signalling pathways to be specifically associated with OA. The miR-17-92 and miR-106a-363 clusters were significantly enriched only in OA. These miRNA clusters exhibited discrete bivariate correlations with several key laboratory (e.g., C-reactive protein) and lung function parameters. Plasma EV miRNA signatures mirrored blood-derived CD4+ T-cell transcriptome data, but achieved an even higher sensitivity in identifying specifically affected biological pathways.

CONCLUSION

The identified plasma EV miRNA signatures and particularly the miR-17-92 and -106a-363 clusters were capable to disentangle specific mechanisms of the obesity-associated low type-2 asthma phenotype, which may serve as basis for stratified treatment development.

Leveraging microRNAs for cellular therapy

Owing to Karl Landsteiner's discovery of blood groups, blood transfusions became safe cellular therapies in the early 1900s. Since then, cellular therapy made great advances from transfusions with unmodified cells to today's commercially available chimeric antigen receptor (CAR) T cells requiring complex manufacturing. Modern cellular therapy products can be improved using basic knowledge of cell biology and molecular genetics. Emerging genome engineering tools are becoming ever more versatile and precise and thus catalyze rapid progress towards programmable therapeutic cells that compute input and respond with defined output. Despite a large body of literature describing important functions of non-coding RNAs including microRNAs (miRNAs), the vast majority of cell engineering efforts focuses on proteins. However, miRNAs form an important layer of posttranscriptional regulation of gene expression. Here, we highlight examples of how miRNAs can successfully be incorporated into engineered cellular therapies.

Controlling viral inflammatory lesions by rebalancing immune response patterns

In this review, we discuss a variety of immune modulating approaches that could be used to counteract tissue-damaging viral immunoinflammatory lesions which typify many chronic viral infections. We make the point that in several viral infections the lesions can be largely the result of one or more aspects of the host response mediating the cell and tissue damage rather than the virus itself being directly responsible. However, within the reactive inflammatory lesions along with the pro-inflammatory participants there are also other aspects of the host response that may be acting to constrain the activity of the damaging components and are contributing to resolution. This scenario should provide the prospect of rebalancing the contributions of different host responses and hence diminish or even fully control the virus-induced lesions. We identify several aspects of the host reactions that influence the pattern of immune responsiveness and describe approaches that have been used successfully, mainly in model systems, to modulate the activity of damaging participants and which has led to lesion control. We emphasize examples where such therapies are, or could be, translated for practical use in the clinic to control inflammatory lesions caused by viral infections.

MicroRNAs in T Cell-Immunotherapy

MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.

MicroRNAs at the Crossroad between Immunoediting and Oncogenic Drivers in Hepatocellular Carcinoma

Simple Summary

In recent years, treatments enhancing the antitumor immune response have revealed a new promising approach for advanced hepatocellular carcinoma (HCC). Beside favorable results in about one third of patients, much still remains to be done to face primary nonresponse, early, and late disease reactivation. Understanding the mechanisms underneath immune system modulation by immune checkpoint inhibitors in HCC might give additional opportunities for patient selection and combined approaches. MicroRNAs have emerged as relevant modulators of cancer cell hallmarks, including aberrant proliferation, invasion and migration capabilities, epithelial-to-mesenchymal transition, and glycolytic metabolism. At the same time, they contribute to the immune system development, response, and programs activation, with particular regard towards regulatory functions. Thus, miRNAs are relevant not only in cancer cells’ biology, but also in the immune response and interplay between cancer, microenvironment, and immune system.

Abstract

Treatments aimed to reverse the tumor-induced immune tolerance represent a promising approach for advanced hepatocellular carcinoma (HCC). Notwithstanding, primary nonresponse, early, and late disease reactivation still represent major clinical challenges. Here, we focused on microRNAs (miRNAs) acting both as modulators of cancer cell hallmarks and immune system response. We outlined the bidirectional function that some oncogenic miRNAs play in the differentiation and program activation of the immune system development and, at the same time, in the progression of HCC. Indeed, the multifaceted spectrum of miRNA targets allows the modulation of both immune-associated factors and oncogenic or tumor suppressor drivers at the same time. Understanding the molecular changes contributing to disease onset, progression, and resistance to treatments might help to identify possible novel biomarkers for selecting patient subgroups, and to design combined tailored treatments to potentiate antitumor approaches. Preliminary findings seem to argue in favor of a bidirectional function of some miRNAs, which enact an effective modulation of molecular pathways driving oncogenic and immune-skipping phenotypes associated with cancer aggressiveness. The identification of these miRNAs and the characterization of their ‘dual’ role might help to unravel novel biomarkers identifying those patients more likely to respond to immune checkpoint inhibitors and to identify possible therapeutic targets with both antitumor and immunomodulatory functions. In the present review, we will focus on the restricted panel of miRNAs playing a bidirectional role in HCC, influencing oncogenic and immune-related pathways at once. Even though this field is still poorly investigated in HCC, it might represent a source of candidate molecules acting as both biomarkers and therapeutic targets in the setting of immune-based treatments.

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial-mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

The Role of microRNA in Pathogenesis, Diagnosis, Different Variants, Treatment and Prognosis of Mycosis Fungoides

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma (CTCL), accounting for approximately 50% of all CTCLs. Although various molecular changes in MF have been described in existing studies, no obvious disease-specific changes have been found thus far. microRNAs (miRs) are short, noncoding RNA molecules that play roles in the post-transcriptional regulation of oncogenes and tumor suppressor genes in various diseases. Recently, there has been rapidly expanding experimental evidence for the role of miRs in the progression, early diagnosis, prognosis prediction for MF. Efforts to improve early diagnosis and develop personalized therapy options have become more important in recent years. Here, we provide an overview and update of recent advances regarding miRs associated with MF. Furthermore, we provide insights into future opportunities for miR-based therapies.

miRNAs in the Regulation of Cancer Immune Response: Effect of miRNAs on Cancer Immunotherapy

In the last few decades, carcinogenesis has been extensively explored and substantial research has identified immunogenic involvement in various types of cancers. As a result, immune checkpoint blockers and other immune-based therapies were developed as novel immunotherapeutic strategies. However, despite being a promising therapeutic option, immunotherapy has significant constraints such as a high cost of treatment, unpredictable toxicity, and clinical outcomes. miRNAs are non-coding, small RNAs actively involved in modulating the immune system's multiple signalling pathways by binding to the 3'-UTR of target genes. miRNAs possess a unique advantage in modulating multiple targets of either the same or different signalling pathways. Therefore, miRNA follows a 'one drug multiple target' hypothesis. Attempts are made to explore the therapeutic promise of miRNAs in cancer so that it can be transported from bench to bedside for successful immunotherapeutic results. Therefore, in the current manuscript, we discussed, in detail, the mechanism and role of miRNAs in different types of cancers relating to the immune system, its diagnostic and therapeutic aspect, the effect on immune escape, immune-checkpoint molecules, and the tumour microenvironment. We have also discussed the existing limitations, clinical success and the prospective use of miRNAs in cancer.

Regulation of Adaptive Tumor Immunity by Non-Coding RNAs

Cancer immunology research has mainly focused on the role of protein-coding genes in regulating immune responses to tumors. However, despite more than 70% of the human genome is transcribed, less than 2% encodes proteins. Many non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have been identified as critical regulators of immune cell development and function, suggesting that they might play important roles in orchestrating immune responses against tumors. In this review, we summarize the scientific advances on the role of ncRNAs in regulating adaptive tumor immunity, and discuss their potential therapeutic value in the context of cancer immunotherapy.

MicroRNAs: Key Regulators in Lung Cancer

Noncoding RNAs have emerged as key regulators of the genome upon gene expression profiling and genome-wide sequencing. Among these noncoding RNAs, microRNAs are short noncoding RNAs that regulate a plethora of functions, biological processes and human diseases by targeting the messenger RNA stability through 3'UTR binding, leading to either mRNA cleavage or translation repression, depending on microRNA-mRNA complementarity degree. Additionally, strong evidence has suggested that dysregulation of miRNAs contribute to the etiology and progression of human cancers, such as lung cancer, the most common and deadliest cancer worldwide. Indeed, by acting as oncogenes or tumor suppressors, microRNAs control all aspects of lung cancer malignancy, including cell proliferation, survival, migration, invasion, angiogenesis, cancer stem cells, immune-surveillance escape, and therapy resistance; and their expressions are often associated with clinical parameters. Moreover, several deregulated microRNAs in lung cancer are carried by exosomes, microvesicles and secreted in body fluids, mainly the circulation where they conserve their stable forms. Subsequently, seminal efforts have been focused on extracellular microRNAs levels as noninvasive diagnostic and prognostic biomarkers in lung cancer. In this review, focusing on recent literature, we summarize the deregulation, mechanisms of action, functions and highlight clinical applications of miRNAs for better management and design of future lung cancer targeted therapies.

MicroRNAs: immune modulators in cancer immunotherapy

MicroRNA (miRNA) is a class of endogenous small non-coding RNA of 18–25 nucleotides and plays regulatory roles in both physiological and pathological processes. Emerging evidence support that miRNAs function as immune modulators in tumors. MiRNAs as tumor suppressors or oncogenes are also found to be able to modulate anti-tumor immunity or link the crosstalk between tumor cells and immune cells surrounding. Based on the specific regulating function, miRNAs can be used as predictive, prognostic biomarkers, and therapeutic targets in immunotherapy. Here, we review new findings about the role of miRNAs in modulating immune responses, as well as discuss mechanisms underlying their dysregulation, and their clinical potentials as indicators of tumor prognosis or to sensitize cancer immunotherapy.

Antigenic Restimulation of Virus-Specific Memory CD8+ T Cells Requires Days of Lytic Protein Accumulation for Maximal Cytotoxic Capacity

In various infections or vaccinations of mice or humans, reports of the persistence and the requirements for restimulation of the cytotoxic mediators granzyme B (GrB) and perforin (PRF) in CD8+ T cells have yielded disparate results. In this study, we examined the kinetics of PRF and GrB mRNA and protein expression after stimulation and associated changes in cytotoxic capacity in virus-specific memory cells in detail. In patients with controlled HIV or cleared respiratory syncytial virus (RSV) or influenza virus infections, all virus-specific CD8+ T cells expressed low PRF levels without restimulation. Following stimulation, they displayed similarly delayed kinetics for lytic protein expression, with significant increases occurring by days 1 to 3 before peaking on days 4 to 6. These increases were strongly correlated with, but were not dependent upon, proliferation. Incremental changes in PRF and GrB percent expression and mean fluorescence intensity (MFI) were highly correlated with increases in HIV-specific cytotoxicity. mRNA levels in HIV-specific CD8+ T-cells exhibited delayed kinetics after stimulation as with protein expression, peaking on day 5. In contrast to GrB, PRF mRNA transcripts were little changed over 5 days of stimulation (94-fold versus 2.8-fold, respectively), consistent with posttranscriptional regulation. Changes in expression of some microRNAs, including miR-17, miR-150, and miR-155, suggested that microRNAs might play a significant role in regulation of PRF expression. Therefore, under conditions of extremely low or absent antigen levels, memory virus-specific CD8+ T cells require prolonged stimulation over days to achieve maximal lytic protein expression and cytotoxic capacity.IMPORTANCE Antigen-specific CD8+ T cells play a major role in controlling most virus infections, primarily by perforin (PRF)- and granzyme B (GrB)-mediated apoptosis. There is considerable controversy regarding whether PRF is constitutively expressed, rapidly increased similarly to a cytokine, or delayed in its expression with more prolonged stimulation in virus-specific memory CD8+ T cells. In this study, the degree of cytotoxic capacity of virus-specific memory CD8+ T cells was directly proportional to the content of lytic molecules, which required antigenic stimulation over several days for maximal levels. This appeared to be modulated by increases in GrB transcription and microRNA-mediated posttranscriptional regulation of PRF expression. Clarifying the requirements for maximal cytotoxic capacity is critical to understanding how viral clearance might be mediated by memory cells and what functions should be induced by vaccines and immunotherapies.

Chimeric antigen receptor T-cell immunotherapy for glioblastoma: practical insights for neurosurgeons

The prognosis for glioblastoma (GBM) remains exceedingly poor despite state-of-the-art multimodal therapy. Immunotherapy, particularly with cytotoxic T cells, represents a promising alternative. Perhaps the most prominent T-cell technology is the chimeric antigen receptor (CAR), which in 2017 received accelerated approval from the Food and Drug Administration for the treatment of hematological malignancies. Several CARs for GBM have been recently tested in clinical trials with exciting results. The authors review these clinical data and discuss areas of ongoing research.

Role of miRNAs in immune responses and immunotherapy in cancer

In the past decade, the study of mechanisms of cancer immunity has seen a prominent boom, which paralleled the increased amount of research on the clinical efficacy of immune checkpoint blockade in several lethal types of cancers. This conspicuous effort has led to the development of successful immunotherapy treatment strategies, whose medical impact has been recognized by the awarding of 2018 Nobel Prize in Physiology or Medicine to the two pioneers of check point inhibitor research, Tasuku Honjo and James Allison. Despite these promising achievements, the differences in the clinical response rate in different cancer patients and the high risk of toxicity of immune-based therapies represent crucial challenges. More remarkably, the causes responsible for different outcome (success vs failure) in patients with tumor having same histotype and clinical characteristics remain mostly unknown. MicroRNAs (miRNAs), small regulatory noncoding RNA molecules representing the most studied component of the dark matter of the human genome, are involved in the regulation of many pathways of cancer and immune cells. Therefore, understanding the role of miRNAs in controlling cancer immunity is necessary, as it can contribute to reveal mechanisms that can be modulated to improve the success of immunetherapy in cancer patients. Here, we discuss the latest findings on immune pathways regulated by miRNAs in cancer, miRNA-mediated regulation of immune cells in the tumor microenvironment, and miRNAs as potential target for immunotherapies.

Immunotherapy for Glioblastoma: Adoptive T-cell Strategies

Glioblastoma (GBM) is a devastating disease with an extremely poor prognosis. Immunotherapy via adoptive cell transfer (ACT), especially with T cells engineered to express chimeric antigen receptors (CAR), represents a particularly promising approach. Despite the recent success of CAR T cells for blood cancers, the question remains whether this powerful anticancer therapy will ultimately work for brain tumors, and whether the primary immunologic challenges in this disease, which include antigenic heterogeneity, immune suppression, and T-cell exhaustion, can be adequately addressed. Here, we contextualize these concepts by reviewing recent developments in ACT for GBM, with a special focus on pioneering clinical trials of CAR T-cell therapy.

Aberrant miRNAs Regulate the Biological Hallmarks of Glioblastoma

GBM is the highest incidence in primary intracranial malignancy, and it remains poor prognosis even though the patient is gave standard treatment. Despite decades of intense research, the complex biology of GBM remains elusive. In view of eight hallmarks of cancer which were proposed in 2011, studies related to the eight biological capabilities in GBM have made great progress. From these studies, it can be inferred that miRs, as a mode of post-transcriptional regulation, are involved in regulating these malignant biological hallmarks of GBM. Herein, we discuss state-of-the-art research on how aberrant miRs modulate the eight hallmarks of GBM. The upregulation of 'oncomiRs' or the genetic loss of tumor suppressor miRs is associated with these eight biological capabilities acquired during GBM formation. Furthermore, we also discuss the applicable clinical potential of these research results. MiRs may aid in the diagnosis and prognosis of GBM. Moreover, miRs are also therapeutic targets of GBM. These studies will develop and improve precision medicine for GBM in the future.

MiR-21 is required for anti-tumor immune response in mice: an implication for its bi-directional roles

Here we show that miR-21, a microRNA known for its oncogenic activity, is also essential for mediating immune responses against tumor. Knockout of miR-21 in mice slowed the proliferation of both CD4⁺ and CD8⁺ cells, reduced their cytokine production and accelerated the grafted tumor growth. Further investigations indicated that miR-21 could activate CD4⁺ and CD8⁺ T cells via the PTEN/Akt pathway in response to stimulations. Taken together, these data suggest the key functions of miR-21 in mediating anti-tumor immune response and thereby uncover a bi-directional role of this traditionally known 'oncomiR' in tumorigenesis. Our study may provide new insights for the design of cancer therapies targeting microRNAs, with an emphasis on the dynamic and possibly unexpected role of these molecules.

MicroRNA and extracellular vesicles in glioblastoma: small but powerful

To promote the tumor growth, angiogenesis, metabolism, and invasion, glioblastoma (GBM) cells subvert the surrounding microenvironment by influencing the endogenous activity of other brain cells including endothelial cells, macrophages, astrocytes, and microglia. Large number of studies indicates that the intra-cellular communication between the different cell types of the GBM microenvironment occurs through the functional transfer of oncogenic components such as proteins, non-coding RNAs, DNA and lipids via the release and uptake of extracellular vesicles (EVs). Unlike the communication through the secretion of chemokines and cytokines, the transfer and gene silencing activity of microRNAs through EVs is more complex as the biogenesis and proper packaging of microRNAs is crucial for their uptake by recipient cells. Although the specific mechanism of EV-derived microRNA uptake and processing in recipient cells is largely unknown, the screening, identifying and finally targeting of the EV-associated pro-tumorigenic microRNAs are emerging as new therapeutic strategy to combat the GBM.

Specific immunotherapy generates CD8(+) CD196(+) T cells to suppress lung cancer growth in mice

That specific immunotherapy can inhibit cancer growth has been recognized; its efficiency is to be improved. This study aimed to inhibit lung cancer (LC) growth in a mouse model by using an LC-specific vaccination. In this study, a LC mouse model was created by adoptive transplantation with LC cells. The tumor-bearing mice were vaccinated with LC cell extracts plus adjuvant TNBS or adoptive transplantation with specific CD8(+) CD196(+) T cells. The results showed that the vaccination with LC extracts (LCE)/TNBS markedly inhibited the LC growth and induced CD8(+) CD196(+) T cells in LC tissue and the spleen. These CD8(+) CD196(+) T cells proliferated and produce high levels of perforin upon exposure to LCE and specifically induced LC cell apoptosis. Exposure to TNBS induced RAW264.7 cells to produce macrophage inflammatory protein-3α; the latter activated signal transducer and activator of transcription 3 and further induced perforin expression in the CD8(+) CD196(+) T cells. Adoptive transfer with specific CD8(+) CD196(+) T cells suppressed LC growth in mice. In conclusion, immunization with LC extracts and TNBS can induce LC-specific CD8(+) CD196(+) T cells in LC-bearing mice and inhibit LC growth.

Enhancing adoptive T cell immunotherapy with microRNA therapeutics

Adoptive T cell-based immunotherapies can mediate complete and durable regressions in patients with advanced cancer, but current response rates remain inadequate. Maneuvers to improve the fitness and antitumor efficacy of transferred T cells have been under extensive exploration in the field. Small non-coding microRNAs have emerged as critical modulators of immune system homeostasis and T cell immunity. Here, we summarize recent advances in our understanding of the role of microRNAs in regulating T cell activation, differentiation, and function. We also discuss how microRNA therapeutics could be employed to fine-tune T cell receptor signaling and enhance T cell persistence and effector functions, paving the way for the next generation of adoptive immunotherapies.