Gene-knocked out chimeric antigen receptor (CAR) T cells: Tuning up for the next generation cancer immunotherapy

Significant Advancements and Evolutions in Chimeric Antigen Receptor Design

Recent times have witnessed remarkable progress in cancer immunotherapy, drastically changing the cancer treatment landscape. Among the various immunotherapeutic approaches, adoptive cell therapy (ACT), particularly chimeric antigen receptor (CAR) T cell therapy, has emerged as a promising strategy to tackle cancer. CAR-T cells are genetically engineered T cells with synthetic receptors capable of recognising and targeting tumour-specific or tumour-associated antigens. By leveraging the intrinsic cytotoxicity of T cells and enhancing their tumour-targeting specificity, CAR-T cell therapy holds immense potential in achieving long-term remission for cancer patients. However, challenges such as antigen escape and cytokine release syndrome underscore the need for the continued optimisation and refinement of CAR-T cell therapy. Here, we report on the challenges of CAR-T cell therapies and on the efforts focused on innovative CAR design, on diverse therapeutic strategies, and on future directions for this emerging and fast-growing field. The review highlights the significant advances and changes in CAR-T cell therapy, focusing on the design and function of CAR constructs, systematically categorising the different CARs based on their structures and concepts to guide researchers interested in ACT through an ever-changing and complex scenario. UNIVERSAL CARs, engineered to recognise multiple tumour antigens simultaneously, DUAL CARs, and SUPRA CARs are some of the most advanced instances. Non-molecular variant categories including CARs capable of secreting enzymes, such as catalase to reduce oxidative stress in situ, and heparanase to promote infiltration by degrading the extracellular matrix, are also explained. Additionally, we report on CARs influenced or activated by external stimuli like light, heat, oxygen, or nanomaterials. Those strategies and improved CAR constructs in combination with further genetic engineering through CRISPR/Cas9- and TALEN-based approaches for genome editing will pave the way for successful clinical applications that today are just starting to scratch the surface. The frontier lies in bringing those approaches into clinical assessment, aiming for more regulated, safer, and effective CAR-T therapies for cancer patients.

Strategies for Improving CAR T Cell Persistence in Solid Tumors

CAR T cells require optimization to be effective in patients with solid tumors. There are many barriers affecting their ability to succeed. One barrier is persistence, as to achieve an optimal antitumor response, infused CAR T cells must engraft and persist. This singular variable is impacted by a multitude of factors-the CAR T cell design, lymphodepletion regimen used, expansion method to generate the T cell product, and more. Additionally, external agents can be utilized to augment CAR T cells, such as the addition of novel cytokines, pharmaceutical drugs that bolster memory formation, or other agents during either the ex vivo expansion process or after CAR T cell infusion to support them in the oppressive tumor microenvironment. This review highlights many strategies being used to optimize T cell persistence as well as future directions for improving the persistence of infused cells.

CRISPR-Cas gene knockouts to optimize engineered T cells for cancer immunotherapy

While CAR-T and tgTCR-T therapies have exhibited noteworthy and promising outcomes in hematologic and solid tumors respectively, a set of distinct challenges remains. Consequently, the quest for novel strategies has become imperative to safeguard and more effectively release the full functions of engineered T cells. These factors are intricately linked to the success of adoptive cell therapy. Recently, CRISPR-based technologies have emerged as a major breakthrough for maintaining T cell functions. These technologies have allowed the discovery of T cells' negative regulators such as specific cell-surface receptors, cell-signaling proteins, and transcription factors that are involved in the development or maintenance of T cell dysfunction. By employing a CRISPR-genic invalidation approach to target these negative regulators, it has become possible to prevent the emergence of hypofunctional T cells. This review revisits the establishment of the dysfunctional profile of T cells before delving into a comprehensive summary of recent CRISPR-gene invalidations, with each invalidation contributing to the enhancement of engineered T cells' antitumor capacities. The narrative unfolds as we explore how these advancements were discovered and identified, marking a significant advancement in the pursuit of superior adoptive cell therapy.

CAR-T cell therapy: a game-changer in cancer treatment and beyond

In recent years, cancer has become one of the primary causes of mortality, approximately 10 million deaths worldwide each year. The most advanced, chimeric antigen receptor (CAR) T cell immunotherapy has turned out as a promising treatment for cancer. CAR-T cell therapy involves the genetic modification of T cells obtained from the patient's blood, and infusion back to the patients. CAR-T cell immunotherapy has led to a significant improvement in the remission rates of hematological cancers. CAR-T cell therapy presently limited to hematological cancers, there are ongoing efforts to develop additional CAR constructs such as bispecific CAR, tandem CAR, inhibitory CAR, combined antigens, CRISPR gene-editing, and nanoparticle delivery. With these advancements, CAR-T cell therapy holds promise concerning potential to improve upon traditional cancer treatments such as chemotherapy and radiation while reducing associated toxicities. This review covers recent advances and advantages of CAR-T cell immunotherapy.

Enhancement of cisplatin-induced apoptosis by saffron in human lung cancer cells

BACKGROUND

Cisplatin is a prevalent chemotherapeutic agent, and it has been used extensively to treat lung cancer. However, its clinical efficacy is hampered by its safety profile and dose-limiting toxicity. Saffron is a natural product that has shown significant anticancer effects. The combination treatment of saffron with chemotherapeutic agents has been considered a new strategy.

METHODS

Herein, saffron extract as a natural anticancer substance was combined with cisplatin to assess their combined efficacy against tumor development in vitro. In A549 and QU-DB cell lines, the combined effect of the saffron extract with cisplatin led to a significant reduction in cell viability as compared to cisplatin alone.

RESULTS

After 48 h incubation a considerable reduction in ROS levels in the QU-DB cell line upon treatment with cisplatin in the presence of saffron extract in comparison with cells treated with cisplatin alone. Furthermore, apoptosis increased significantly when in cells treated with cisplatin in combination with saffron extract compared to cisplatin alone.

CONCLUSION

Our data establish that the combination of saffron extract as a natural anticancer substance with cisplatin leads to improved cell toxicity of cisplatin as an anticancer agent. Therefore, the saffron extract could be potentially used as an additive to enable a reduction in cisplatin dosages and its side effects.

Chimeric Antigen Receptor T-Cell Therapy for Solid Tumors: The Past and the Future

Chimeric antigen receptor (CAR) T-cell therapy is the new standard treatment for various indications in patients with advanced hematologic malignancies. Despite the several preclinical and early phase clinical trials, the overall clinical experience has been disappointing when applying this innovative therapy in solid tumors. The failure of CAR T-cell therapy and its limited antitumor activity in solid tumors have been attributed to several mechanisms, including tumor antigen heterogeneity, the hostile tumor microenvironment and poor trafficking of CAR T cells into tumor sites, and the unacceptable toxicities in some settings, among others. However, remarkable improvements have been made in understanding many of these failure mechanisms for which several emerging novel approaches are being applied to overcome these challenges. In this review, after a brief historic background for immunotherapy in solid tumors, we highlight the recent developments achieved in CAR T-cell designs, summarize completed clinical trials, and discuss current challenges facing CAR T-cell therapy and the suggested strategies to overcome these barriers.

Engineering CAR T cells for enhanced efficacy and safety

Despite its success in treating hematologic malignancies, chimeric antigen receptor (CAR) T cell therapy faces two major challenges which hinder its broader applications: the limited effectiveness against solid tumors and the nonspecific toxicities. To address these concerns, researchers have used synthetic biology approaches to develop optimization strategies. In this review, we discuss recent improvements on the CAR and other non-CAR molecules aimed to enhance CAR T cell efficacy and safety. We also highlight the development of different types of inducible CAR T cells that can be controlled by environmental cues and/or external stimuli. These advancements are bringing CAR T therapy one step closer to safer and wider applications, especially for solid tumors.

Evaluation of the Effect of Crocin on Doxorubicin-Induced Cardiotoxicity

Despite newer advances in cancer treatment, chemotherapy is still one of the most widely used treatment strategies in this field. However, this treatment strategy faces major challenges. Doxorubicin (Dox) is an effective chemotherapeutic agent used to treat various cancers. However, several studies have shown that the use of Dox in therapeutic concentrations is associated with serious side effects, such as cardiac toxicity. The use of natural products in combination with chemotherapeutic agents to reduce side effects is a novel approach, and several studies have shown promising results. In this regard, we examined the effect of Crocin on doxorubicin-induced cardiotoxicity in rat and H9c2 cell line. The in vitro model on H9C2 cells and the in vivo models on rats were treated with doxorubicin. Cell viability, DNA damage, and apoptosis were measured in H9C2 cell line in the presence and absence of Crocin. Oxidative stress and various inflammatory parameters, as well as cardiac function tests, also were assessed in doxorubicin-induced cardiotoxicity animal model in the presence and absence of Crocin. Our results showed that Crocin can significantly decrease apoptosis in H9C2 cell line through a reduction in ROS production and DNA damages. Moreover, evaluation of the effect of Crocin on doxorubicin-induced cardiotoxicity animal model showed that Crocin also can significantly reduce oxidative stress and inflammatory parameters in the serum of the animals. Assessment of cardiac function revealed that Crocin has a significant protective effect against doxorubicin-induced cardiotoxicity in the animal model. Our data indicate that Crocin significantly attenuated doxorubicin-induced cardiotoxicity. Hence, Crocin could be potentially used as an adjuvant treatment in combination with Dox to reduce cardiotoxicity.

Efficacy and safety of humanized CD19 CAR-T as a salvage therapy for recurrent CNSL of B-ALL following murine CD19 CAR-T cell therapy

The present study aimed to compare the differences between the humanized CD19 chimeric antigen receptor (CAR)-T cell therapy and the murine CD19 CAR-T therapy in recurrent B-acute lymphoblastic leukemia (B-ALL). A 62-year-old male patient who had B-ALL (BCR/ABL⁺) for 4 years was diagnosed with relapsed central nervous system leukemia (CNSL). After several courses of high dose methotrexate combined with intrathecal chemotherapy, the patient received murine CD19 CAR-T therapy and achieved complete response (CR). The patient was diagnosed with relapsed CNSL again 15 months after his murine CD19 CAR-T therapy, and was therefore enrolled in the humanized CD19 CAR-T therapy. Subsequently, the present study aimed to compare murine and humanized CD19 CAR-T cells against Nalm-6 cells in vitro and in mice. The patient initially achieved CR from his murine CD19 CAR-T therapy with Grade 1 cytokine-release syndrome (CRS) and Grade 1 CAR-T cell-related encephalopathy syndrome (CRES). The patient then achieved CR again from his humanized CD19 CAR-T therapy with Grade 1 CRS and Grade 2 CRES. Peak levels of CD19 CAR-T cells were higher in humanized CD19 CAR-T therapy than those in murine CD19 CAR-T therapy 7 days after infusion in the peripheral blood, in bone marrow and in cerebrospinal fluid (CSF). The cytokine levels were higher in humanized CD19 CAR-T therapy than those in murine CD19 CAR-T therapy in the peripheral blood and in CSF. The cytotoxicity to Nalm-6 cells was higher in humanized CD19 CAR-T cells than that in murine CD19 CAR-T cells in vitro. In Nalm-6 BALB/c mice, the median survival time of mice in the murine CD19 CAR-T group was 35 days, while it was 43 days in the humanized CD19 CAR-T group. In conclusion, humanized CD19 CAR-T cell therapy had a better curative effect than that of murine CD19 CAR-T therapy, and may be used as a salvage treatment for recurrent B-ALL after treatment with murine CD19 CAR-T therapy.

In silico prediction of B and T cell epitopes based on NDV fusion protein for vaccine development against Newcastle disease virus

Newcastle disease (ND) is known as the most common diseases of economic importance worldwide. Vaccination against virulent strains of Newcastle disease virus (NDV) has failed during some outbreaks. Here, we aimed to assess the epitopes of NDV fusion protein as targets for a peptide-based vaccine. To explore the most antigenic epitopes on the F protein, we retrieved virulent strains of genotype VII from National Center for Biotechnology Information (NCBI). Linear and conformational B-cell epitopes were identified. Moreover, T-cell epitopes with high and moderate binding affinities to human major histocompatibility complex (MHC) class I and class II alleles were predicted using bioinformatics tools. Subsequently, the overlapped epitopes of B-cell and MHC class I and MHC class II were determined. To validate our predictions, the best epitopes were docked, to chicken MHC class I (B-F) alleles using the HADDOCK flexible docking server. Seven ‘high ranked epitopes’ were identified. Among them, ‘LYCTRIVTF’ and ‘MRATYLETL’ showed the highest scores. The other five epitopes including LSGEFDATY, LTTPPYMALK, LYLTELTTV, DCIKITQQV and SIAATNEAV obtained very encouraging results as well. SIAATNEAV had been recognized as a neutralizing epitope of F protein using monoclonal antibodies before. Taken together, our results demonstrated that the identified epitopes needed to be tested by in vitro and in vivo experiments.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

CAR-T cells: Early successes in blood cancer and challenges in solid tumors

New approaches to cancer immunotherapy have been developed, showing the ability to harness the immune system to treat and eliminate cancer. For many solid tumors, therapy with checkpoint inhibitors has shown promise. For hematologic malignancies, adoptive and engineered cell therapies are being widely developed, using cells such as T lymphocytes, as well as natural killer (NK) cells, dendritic cells, and potentially others. Among these adoptive cell therapies, the most active and advanced therapy involves chimeric antigen receptor (CAR)-T cells, which are T cells in which a chimeric antigen receptor is used to redirect specificity and allow T cell recognition, activation and killing of cancers, such as leukemia and lymphoma. Two autologous CAR-T products have been approved by several health authorities, starting with the U.S. Food and Drug Administration (FDA) in 2017. These products have shown powerful, inducing, long-lasting effects against B cell cancers in many cases. In distinction to the results seen in hematologic malignancies, the field of using CAR-T products against solid tumors is in its infancy. Targeting solid tumors and trafficking CAR-T cells into an immunosuppressive microenvironment are both significant challenges. The goal of this review is to summarize some of the most recent aspects of CAR-T cell design and manufacturing that have led to successes in hematological malignancies, allowing the reader to appreciate the barriers that must be overcome to extend CAR-T therapies to solid tumors successfully.

Bacteriocins: New Potential Therapeutic Candidates in Cancer Therapy

Cancer is one of the most important disorders which is associated with high mortality and high costs of treatment for patients. Despite several efforts, finding, designing and developing, new therapeutic platforms in the treatment of cancer patients are still required. Utilization of microorganisms, particularly bacteria has emerged as new therapeutic approaches in the treatment of various cancers. Increasing data indicated that bacteria could be used in the production of a wide range of anti-cancer agents, including bacteriocins, antibiotics, peptides, enzymes, and toxins. Among these anti-cancer agents, bacteriocins have attractive properties, which make them powerful anti-cancer drugs. Multiple lines evidence indicated that several bacteriocins (i.e., colcins, nisins, pediocins, pyocins, and bovocins) via activation/inhibition different cellular and molecular signaling pathways are able to suppress tumor growth in various stages. Hence, identification and using various bacteriocins could lead to improve and introduce them to clinical practices. Here, we summarized various bacteriocins which could be employed as anti-cancer agents in the treatment of many cancers.

Vitamin D and Non-coding RNAs: New Insights into the Regulation of Breast Cancer

Breast cancer, a life-threatening serious disease with a high incident rate among women, is responsible for thousands of cancer-associated death worldwide. Numerous investigations have evaluated the possible mechanisms related to this malignancy. Among them, non-coding RNAs (ncRNAs), i.e., microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs have recently attracted attention of researchers. In addition to recent studies for evaluating the role of ncRNAs in breast cancer etiology, some investigations have revealed that vitamin D has regulatory and therapeutic roles in breast cancer. Moreover, an important link between vitamin D and ncRNAs in cancer therapy has been highlighted. Herein, the aim of this study was to discuss the available data on the mentioned link in breast cancer.

Chimeric antigen receptor (CAR) natural killer (NK)-cell therapy: leveraging the power of innate immunity

Chimeric antigen receptor (CAR) T cells are a rapidly emerging form of cancer treatment, and have resulted in remarkable responses in refractory lymphoid malignancies. However, their widespread clinical use is limited by toxicity related to cytokine release syndrome and neurotoxicity, the logistic complexity of their manufacturing, cost and time-to-treatment for autologous CAR-T cells, and the risk of graft-versus-host disease (GvHD) associated with allogeneic CAR-T cells. Natural killer (NK) cells have emerged as a promising source of cells for CAR-based therapies due to their ready availability and safety profile. NK cells are part of the innate immune system, providing the first line of defence against pathogens and cancer cells. They produce cytokines and mediate cytotoxicity without the need for prior sensitisation and have the ability to interact with, and activate other immune cells. NK cells for immunotherapy can be generated from multiple sources, such as expanded autologous or allogeneic peripheral blood, umbilical cord blood, haematopoietic stem cells, induced pluripotent stem cells, as well as cell lines. Genetic engineering of NK cells to express a CAR has shown impressive preclinical results and is currently being explored in multiple clinical trials. In the present review, we discuss both the preclinical and clinical trial progress made in the field of CAR NK-cell therapy, and the strategies to overcome the challenges encountered.

Envisioning the immune system to determine its role in pancreatic ductal adenocarcinoma: Culprit or victim?

Pancreatic ductal adenocarcinoma has a poor 5-year survival rate that makes it one of the most fatal human malignancies. Unfortunately, despite the serious improvement in the survival of most cancers, there has been a minor advance in pancreatic cancer (PC). Major advances in PC treatment have been assessed over the bygone twenty-year time span, yet some complications make the survival of the patients shorter. Getting to know the PC tumor microenvironment (TME) and the immunosuppression that happens during the pathogenesis of this malignancy could be a great help to understand the nature of the immune system and find better treatment modalities based on it. Although many immune cells are present in PC, immunosuppression of the TME leads to severe immune dysfunction in the patients, therefore immune effectors fail to do their functions. Lately, immunotherapy has been presented as one of the promising treatment strategies for different malignancies including hepatocellular carcinoma, melanoma, non-small cell lung cancer, and kidney cancer. In PC, there has been shown promising results centered around the TME, immune checkpoint inhibitors, cancer vaccines, and other approaches especially when used as combinational therapy. Here we dig a little deeper into the role of the immune system and possible therapeutic options in the treatment of PC.

Comprehensive assessment of PD-L1 and PD-L2 dysregulation in gastrointestinal cancers

Background: PD-L1 and PD-L2 are ligands of PD-1. Their overexpression has been reported in different cancers. However, the underlying mechanism of PD-L1 and PD-L2 dysregulation and their related signaling pathways are still unclear in gastrointestinal cancers. Materials & methods: The expression of PD-L1 and PD-L2 were studied in The Cancer Genome Atlas and Genotype-Tissue Expression databases. The gene and protein alteration of PD-L1 and PD-L2 were analyzed in cBioportal. The direct transcription factor regulating PD-L1/PD-L2 was determined with ChIP-seq data. The association of PD-L1/PD-L2 expression with clinicopathological parameters, survival, immune infiltration and tumor mutation burden were investigated with data from The Cancer Genome Atlas. Potential targets and pathways of PD-L1 and PD-L2 were determined by protein enrichment, WebGestalt and gene ontology. Results: Comprehensive analysis revealed that PD-L1 and PD-L2 were significantly upregulated in most types of gastrointestinal cancers and their expressions were positively correlated. SP1 was a key transcription factor regulating the expression of PD-L1. Conclusion: Higher PD-L1 or PD-L2 expression was significantly associated with poor overall survival, higher tumor mutation burden and more immune and stromal cell populations. Finally, HIF-1, ERBB and mTOR signaling pathways were most significantly affected by PD-L1 and PD-L2 dysregulation. Altogether, this study provided comprehensive analysis of the dysregulation of PD-L1 and PD-L2, its underlying mechanism and downstream pathways, which add to the knowledge of manipulating PD-L1/PD-L2 for cancer immunotherapy.

A metabolic switch to memory CAR T cells: Implications for cancer treatment

Therapeutic efficacy of chimeric antigen receptor (CAR) T cells is associated with their expansion, persistence and effector function. Although CAR T cell therapy has shown remarkable therapeutic effects in hematological malignancies, its therapeutic efficacy has been limited in some types of cancers - in particular, solid tumors - partially due to the cells' inability to persist and the acquisition of T cell dysfunction within a harsh immunosuppressive tumor microenvironment. Therefore, it would be expected that generation of CAR T cells with intrinsic properties for functional longevity, such as the cells with early-memory phenotypes, could beneficially enhance antitumor immunity. Furthermore, because the metabolic pathways of CAR T cells help determine cellular differentiation and lifespan, therapies targeting such pathways like glycolysis and oxidative phosphorylation, can alter CAR T cell fate and durability within tumors. Here we discuss how reprogramming of CAR T cell metabolism and metabolic switch to memory CAR T cells influences their antitumor activity. We also offer potential strategies for targeting these metabolic circuits in the setting of adoptive CAR T cell therapy, aiming to better unleash the potential of adoptive CAR T cell therapy in the clinic.

Acute Graft-Versus-Host Disease After Humanized Anti-CD19-CAR T Therapy in Relapsed B-ALL Patients After Allogeneic Hematopoietic Stem Cell Transplant

We studied the acute graft-versus-host disease (GVHD) after humanized anti-CD19-CAR T therapy in relapsed B-acute lymphoblastic leukemia (ALL) patients after allogeneic hematopoietic stem cell transplant (allo-HSCT). Fifteen B-ALL patients were enrolled in our study. Thirteen patients (86.67%) achieved a complete response (CR) or CR with incomplete count recovery. The donor chimerism of the 13 patients reached 99.86 ± 0.21%. The development of aGVHD was observed in 10 patients (66.67%). Six patients developed grade I-II of aGVHD, while the other four patients developed grade III-IV of aGVHD. The notable adverse events were grade 1–2 cytokine release syndrome (CRS) in 10 patients and grade 3–4 CRS in five patients. Two patients died of infection, while another patient died of sudden cardiac arrest. The anti-CD19-CAR T cells were not eliminated in peripheral blood when the patients developed aGVHD. However, we did not observe their expansion peaks again in the process of aGVHD. During the aGVHD, the peaks of IL-6 and TNF-a were correlated with aGVHD levels. By May 31, 2020, the rates of leukemia-free survival (LFS) and overall survival (OS) at 180 days were 53.846 and 61.638%, respectively. All the patients who survived to date experienced aGVHD after humanized anti-CD19-CAR T cell therapy.

Trial registration: The patients were enrolled in clinical trials of ChiCTR-ONN-16009862 and ChiCTR1800019622.

[Maintenance therapy following CD19 CAR-T treatment for relapsed B-cell acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation]

Objective: This study aimed to evaluate the maintenance therapy following an anti-CD19-CAR T-cell therapy for a B-cell acute lymphoblastic leukemia (ALL) patient who relapsed after allogeneic hematopoietic cell transplantation (allo-HSCT) and investigate the effect of donor stem cells and donor T lymphocyte infusion on the amplification of CD19 CAR-T cells. Methods: One refractory B-ALL patient relapsed after murine CD19 CAR-T cell therapy followed by a sibling allo-HSCT. He underwent a humanized CD19 CAR-T cell therapy followed by donor stem cell and donor T lymphocytes infusions as maintenance therapy in our hospital. The level of cytokines, the proportion of CD19 CAR-T cell, the level of CAR19 DNA expression in the peripheral blood, and the proportion of leukemia cells and donor chimerism in the bone marrow were detected. Correspondingly, T lymphocytes from the C57 spleen were separated to modify the CD19 CAR lentivirus and refused into C57 mice, and after 14 days, the B lymphocytes from C57 mice were separated and refused into the same C57 mice. The CD19 CAR T cells, B cells, and CD19 CAR gene counts in the peripheral blood were evaluated at different time points. Results: ①The patient achieved a complete response (CR) 14 days after a humanized CD19 CAR-T therapy with grade 1 cytokine release syndrome (CRS) and restored a donor chimerism to 99.76%. ② Following the remission from humanized CD19 CAR-T therapy, the patient received a maintenance therapy of donor stem cell infusion. Mild graft-versus-host disease (GVHD) manifested 24 days after infusion with an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood. It fell with the remission of GVHD. The patient maintained CR and 99.69% donor chimerism during this period. ③ Throughout the subsequent donor T lymphocytes maintenance therapy, mild GVHD surfaced12 days after infusion without an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood. The patient maintained CR and 99.87% donor chimerism during this period. ④ In vivo experiments on C57 mice confirmed that the proportion of CD19 CAR-T cells and the level of CAR19 DNA expression were upregulated in mice following CAR-T cell infusion, accompanied by depletion of CD19(+) B lymphocyte. After infusion of CD19(+) B lymphocyte cells, an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood were observed again. Conclusions: The infusion of donor stem cells and donor T lymphocytes could be used as a maintenance treatment after CD19 CAR-T cell therapy for B-ALL patients who relapsed after allo-HSCT. Infusion of donor stem cells induced an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression with the occurrence of GVHD. It might lead to further elimination of minimal residual disease.

A brief review concerning Chimeric Antigen Receptors T cell therapy

The understanding concerning the function of immune system in cancer has achieved considerable advance with time passes by. Manipulating genetically engineered immune cells were investigated as a novel strategy for treating cancer. Chimeric antigen receptors (CARs) are recombinant protein molecules by merging the exquisite targeting the potent cytotoxicity of T cells and specificity of monoclonal antibodies and, which could trigger serial cascades of signal transduction and thereby activate T cells to directly destroy the tumor cells. Manufacturing CAR-modified T lymphocytes were successfully implemented in treating cancer derived from they could specifically retarget tumor-associated antigens, causing effective elimination of tumor cells, which spurred the optimization and development of new CAR-T cell technology. The advancement of synthetic biology methodologies of cell therapy in CAR-T would ultimately provide us with a much safer, reliable and efficient modality to against cancer. This review primarily described the emergence, development and application of cell therapy in CAR-T, then discuss the side effects and the potential factors of tumor reccurrence caused by CAR-T cell therapy, in addition to the corresponding countermeasure concerning complications.

Expression profile of stem cell markers and ABC transporters in 5-fluorouracil resistant Hep-2 cells

Resistance of laryngeal squamous cell carcinoma cells to traditional therapeutic regimens still remains to be a major reason for therapeutic failure in patients. In this study, we aimed at investigating the expression profiles of ATP-binding cassette (ABC) transporters and stem cell markers in 5-fluorouracil (5-FU) resistant laryngeal Hep-2 cells. We treated parental Hep-2 cells, with stepwise increased doses of 5-FU for almost 1 year to develop 5-FU resistant sub-lines with resistance against varying levels of 5-FU concentrations (4 sub-lines resistant to 1, 2, 4, and eightfold of 5-FU). Then, we measured the expression levels of 10 genes from ABC transporters family and 4 stem cell associated markers using quantitative reverse transcription polymerase chain reaction (qRT-PCR) to find out a potential relationship between these markers and chemoresistance. We found that stemness-associated markers had elevated expressions from the beginning of 5-FU resistance acquisition. Their expressions elevated stepwise while parental Hep-2 cells got resistance to higher doses of 5-FU. Expressions of tested ABC transporters (ABCA5, ABCB1, ABCB6, ABCC1, ABCC2, ABCC3, ABCC5, ABCC10 and ABCF2, and ABCG2) were also deregulated in 5-FU resistant Hep-2 cells. Although their expressions remained unaltered at the beginning of acquisition of resistance, expressions of ABC transporters except from ABCB6 increased significantly when cells became resistant to higher doses of 5-FU. Our results suggest that enrichment of cells with stemness characteristics and upregulation of ABC transporters might be amongst the crucial contributors of chemoresistance in laryngeal cancer cells.

CAR T-cell immunotherapy of B-cell malignancy: the story so far

Chimeric antigen receptor (CAR) T-cell immunotherapy has achieved unprecedented efficacy in the treatment of chemotherapy-resistant or refractory B-cell malignancies. Promising results from pivotal anti-CD19 CAR T-cell phase II trials have led to landmark approvals of two CD19-specific CAR T-cell products by the United States Food and Drug Administration and European Medicines Agency. However, several issues associated with CAR T-cell treatment remain unresolved, such as the management of severe toxicities and the frequent occurrence of both antigen-positive and antigen-negative relapse. Nonetheless, pre-clinical research is advancing at an unprecedented pace to develop innovative solutions to address these issues. Herein, we summarise recent clinical developments and outcomes of CD19-targeted CAR T-cell immunotherapy and discuss emerging strategies that may further improve the success, safety and broadened applicability of this approach.

Advance genome editing technologies in the treatment of human diseases: CRISPR therapy (Review)

Genome editing techniques are considered to be one of the most challenging yet efficient tools for assisting therapeutic approaches. Several studies have focused on the development of novel methods to improve the efficiency of gene editing, as well as minimise their off-target effects. Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas9) is a tool that has revolutionised genome editing technologies. New applications of CRISPR/Cas9 in a broad range of diseases have demonstrated its efficiency and have been used in ex vivo models of somatic and pluripotent stem cells, as well as in in vivo animal models, and may eventually be used to correct defective genes. The focus of the present review was the recent applications of CRISPR/Cas9 and its contribution to the treatment of challenging human diseases, such as various types of cancer, neurodegenerative diseases and a broad spectrum of other disorders. CRISPR technology is a novel method for disease treatment, enhancing the effectiveness of drugs and improving the development of personalised medicine.

Gene modification strategies for next-generation CAR T cells against solid cancers

Immunotherapies have become the backbone of cancer treatment. Among them, chimeric antigen receptor (CAR) T cells have demonstrated great success in the treatment of hematological malignancies. However, CAR T therapy against solid tumors is less effective. Antigen targeting; an immunosuppressive tumor microenvironment (TME); and the infiltration, proliferation, and persistence of CAR T cells are the predominant barriers preventing the extension of CAR T therapy to solid tumors. To circumvent these obstacles, the next-generation CAR T cells will require more potent antitumor properties, which can be achieved by gene-editing technology. In this review, we summarize innovative strategies to enhance CAR T cell function by improving target identification, persistence, trafficking, and overcoming the suppressive TME. The construction of multi-target CAR T cells improves antigen recognition and reduces immune escape. Enhancing CAR T cell proliferation and persistence can be achieved by optimizing costimulatory signals and overexpressing cytokines. CAR T cells equipped with chemokines or chemokine receptors help overcome their poor homing to tumor sites. Strategies like knocking out immune checkpoint molecules, incorporating dominant negative receptors, and chimeric switch receptors can favor the depletion or reversal of negative T cell regulators in the TME.

Cancer Stem Cells and Combination Therapies to Eradicate Them

Cancer stem cells (CSCs) show self-renewal ability and multipotential differentiation, like normal stem or progenitor cells, and which proliferate uncontrollably and can escape the effects of drugs and phagocytosis by immune cells. Traditional monotherapies, such as surgical resection, radiotherapy and chemotherapy, cannot eradicate CSCs, however, combination therapy may be more effective at eliminating CSCs. The present review summarizes the characteristics of CSCs and several promising combination therapies to eradicate them.

Cancer stem cells and oral cancer: insights into molecular mechanisms and therapeutic approaches

Cancer stem cells (CSCs) have been identified as a little population of cancer cells, which have features as the same as the cells normal stem cells. There is enough knowledge of the CSCs responsibility for metastasis, medicine resistance, and cancer outbreak. Therefore, CSCs control possibly provides an efficient treatment intervention inhibiting tumor growth and invasion. In spite of the significance of targeting CSCs in treating cancer, few study comprehensively explored the nature of oral CSCs. It has been showed that oral CSCs are able to contribute to oral cancer progression though activation/inhibition a sequences of cellular and molecular pathways (microRNA network, histone modifications and calcium regulation). Hence, more understanding about the properties of oral cancers and their behaviors will help us to develop new therapeutic platforms. Head and neck CSCs remain a viable and intriguing option for targeted therapy. Multiple investigations suggested the major contribution of the CSCs to the metastasis, tumorigenesis, and resistance to the new therapeutic regimes. Therefore, experts in the field are examining the encouraging targeted therapeutic choices. In spite of the advancements, there are not enough information in this area and thus a magic bullet for targeting and eliminating the CSCs deviated us. Hence, additional investigations on the combined therapies against the head and neck CSCs could offer considerable achievements. The present research is a review of the recent information on oral CSCs, and focused on current advancements in new signaling pathways contributed to their stemness regulation. Moreover, we highlighted various therapeutic approaches against oral CSCs.

CAR T cell therapy: newer approaches to counter resistance and cost

The genetically engineered Chimeric Antigen Receptor bearing T-cell (CAR T cell) therapy has been emerged as the new paradigm of cancer immunotherapy. However, recent studies have reported an increase in the number of relapsed haematological malignancies. This review provides newer insights into how the efficacy of CAR T cells might be increased by the application of new genome editing technologies, monitoring the complexity of tumor types and T cells sub-types. Next, tumor mutation burden along with tumormicroenvironment and epigenetic mechanisms of CAR T cell as well as tumor cell may play a vital role to tackle the cancer resistance mechanisms. These studies highlight the need to consider traditional cancer therapy in conjunction with CAR T cell therapy for relapsed or cases unresponsive to treatment. Of note, this therapy is highly expensive and requires multi-skill for successful implementation, which results in reduction of its accessibility/affordability to the patients. Here, we also propose a model for cost minimization of CAR T cell therapy by a collaboration of academia, hospitals and industry.

Hyaluronic Acid and Regenerative Medicine: New Insights into the Stroke Therapy

Stroke is known as one of the very important public health problems that are related to societal burden and tremendous economic losses. It has been shown that there are few therapeutic approaches for the treatment of this disease. In this regard, the present therapeutic platforms aim to obtain neuroprotection, reperfusion, and neuro recovery. Among these therapies, regenerative medicine-based therapies have appeared as new ways of stroke therapy. Hyaluronic acid (HA) is a new candidate, which could be applied as a regenerative medicine-based therapy in the treatment of stroke. HA is a glycosaminoglycan composed of disaccharide repeating elements (N-acetyl-Dglucosamine and D-glucuronic acid). Multiple lines of evidence demonstrated that HA has critical roles in normal tissues. It can be a key player in different physiological and pathophysiological conditions such as water homeostasis, multiple drug resistance, inflammatory processes, tumorigenesis, angiogenesis, and changed viscoelasticity of the extracellular matrix. HA has very important physicochemical properties i.e., availability of reactive functional groups and its solubility, which make it a biocompatible material for application in regenerative medicine. Given that HAbased bioscaffolds and biomaterials do not induce inflammation or allergies and are hydrophilic, they are used as soft tissue fillers and injectable dermal fillers. Several studies indicated that HA could be employed as a new therapeutic candidate in the treatment of stroke. These studies documented that HA and HA-based therapies exert their pharmacological effects via affecting stroke-related processes. Herein, we summarized the role of the extracellular matrix in stroke pathogenesis. Moreover, we highlighted the HA-based therapies for the treatment of stroke.

Sequential treatment with aT19 cells generates memory CAR-T cells and prolongs the lifespan of Raji-B-NDG mice

Treatment with chimeric antigen receptor (CAR)-modified T cells targeting CD19 has proved successful in patients with relapsed/refractory B cell malignancies. However, long-term follow-up indicates that remission in a substantial proportion of patients is not sustainable. Most patients that experience recurrence have tumors and lost the CAR-T cells. To maintain the activity of CAR-T cells, Raji-B-NDG mice were treated sequentially with CAR-T-19 cells and homologous cells expressing human CD19 to promote expansion of CAR-T cells. Sequential treatment of mice with CAR-T-19 cells followed by Raji tumor cells led to marked prolongation of survival. The best case scenario after sequential treatment was a survival time of more than 200 days; the average survival time of mice in the non-sequential treatment group was 80 days. We treated mice with autologous CD19-modified T cells after initial treatment with CAR-T-19 cells. The overall survival and recurrence-free survival times of mice receiving sequential treatment were significantly longer. The percentages of CAR+ T cells in peripheral blood increased. Sequential therapy with autologous CAR-T-19 and aT19 cells provides a new strategy for generating memory CAR-T cells, which may lead ultimately to increased clinical efficacy.

Cancer stem cells as therapeutic targets of pancreatic cancer

The discovery of stem cells and their potential abilities in self-renewal and differentiation has opened a new horizon in medicine. Scientists have found a small population of stem cells in some types of cancers with the same functions as normal stem cells. There are two models for tumor progression: clonal (stochastic) and cancer stem cell (CSCs) models. According to the first model, all transformed cells in the tumor have carcinogenic potential and are able to proliferate and produce the same cells. The latter model, which has received more attention recently, considers the role of CSCs in drug resistance and tumor metastasis. Following the model, researchers have found that targeting CSCs may be a promising way in cancer therapy. This review describes CSC characteristics in general, while also focusing on CSC properties in the context of pancreatic cancer.

Chimeric Antigen Receptor-Engineered T-Cells - A New Way and Era for Lymphoma Treatment

BACKGROUND

Patients with refractory or relapsed diffuse large B-cell lymphoma have a poor prognosis with the current standard of care.

OBJECTIVE

Chimeric Antigen Receptor T-cells (CAR T-cells) are functionally reprogrammed lymphocytes, which are able to recognize and kill tumor cells. The aim of this study is to make progress in this area.

METHODS

A mini-review was achieved using the articles published in Web of Science and PubMed in the last year and the new patents were made in this field.

RESULTS

The responses to CAR T-cell products axicabtagene ciloleucel and tisagenlecleucel are promising; the objective response rate can reach up to 83%, and the complete response rate ranges between 40 and 58%. About half of the patients may have serious side effects, such as cytokine release syndrome and neurotoxicity. Current and future developments include the improvement of CAR T-cell expansion and polyfunctionality, the combined use of CAR T-cells with a fusion protein between interferon and an anti-CD20 monoclonal antibody, with checkpoint inhibitors or small molecule sensitizers that have apoptotic-regulatory effects. Furthermore, the use of IL-12-expressing CAR T-cells, an improved technology for the production of CAR T-cells based on targeted nucleases, the widespread use of allogeneic CAR T-cells or universal CAR T-cells obtained from genetically engineered healthy donor T-cells are future developments actively considered.

CONCLUSION

CAR T-cell therapy significantly improved the outcome of patients with relapsed or refractory diffuse large B-cell lymphoma. The advances in CAR T-cells production technology will improve the results and enable the expansion of this new immunotherapy.

Knockdown of Sal-like 4 expression by siRNA induces apoptosis in colorectal cancer

Colorectal cancer (CRC) is known as the third most common malignancies among men and women and is also the second leading cause of cancer-related deaths worldwide. It has been indicated that a variety of risk factors are involved in the pathogenesis of CRC. Spalt-like transcription factor 4 (SALL4) is known as a transcription factor that plays an important role in the proliferation of cancerous cells. In this study, using a specific sequence of small interfering RNA (siRNA) against the sequence of SALL4, its activity is investigated in the CRC cell line (sw742). The CRC cells (sw742) were cultured and then, using a specific anti-SALL4 siRNA, their toxic doses were determined. Then, the gene is transfected into the cell. Proliferation and expression of the SALL4 and Bcl-2 gene were measured using the real-time polymerase chain reaction method. Cell death was evaluated by propidium iodide staining and fluorescence-activated cell sorting analysis. Our results indicated that the specific concentration of siRNA of the SALL4 gene was 62.5 nmole. Gene expression of SALL4 and Bcl-2 results showed that expression of Bcl-2 gene in the siRNA group was significantly reduced. In conclusion, our finding indicated that it could be used as a therapeutic and diagnostic biomarker in the treatment of patients with CRC.

MicroRNA and exosome: Key players in rheumatoid arthritis

Rheumatoid arthritis (RA) is known as one of important autoimmune disorders which can lead to joint pain and damage throughout body. Given that internal (ie, genetic and epigenetic alterations) and external factors (ie, lifestyle changes, age, hormones, smoking, stress, and obesity) involved in RA pathogenesis. Increasing evidence indicated that cellular and molecular alterations play critical roles in the initiation and progression of RA. Among various targets and molecular signaling pathways, microRNAs (miRNAs) and their regulatory networks have key roles in the RA pathogenesis. It has been showed that deregulation of many miRNAs involved in different stages of RA. Hence, identification of miRNAs and their signaling pathways in RA, could contribute to new knowledge which help to better treatment of patients with RA. Besides miRNAs, exosomes have been emerged as key messengers in RA pathogenesis. Exsosomes are nanocarriers which could be released from various cells and lead to changing of behaviors recipient cells via targeting their cargos (eg, proteins, messenger RNAs, miRNAs, long noncoding RNAs, DNAs). Here, we summarized several miRNAs involved in RA pathogenesis. Moreover, we highlighted the roles of exosomes in RA pathogenesis.

Leukemia-derived exosomes: Bringing oncogenic signals to blood cells

Leukemia is a cancer, which is derived from leukocytes and precursors of leukocytes in the bone marrow. A large number of pivotal biological processes are linked to leukemia pathogenesis. More insights into these mechanisms can provide a better developing pharmacological platform for patients with leukemia. Among the different players in leukemia pathogenesis, exosomes have appeared as a new biological vehicle, which can transfer oncogenic signals to blood cells. Exosomes are nano-carriers, which enable transferring numerous cargos such as DNA fragments, RNAs, messenger RNAs, microRNAs, long noncoding RNA, and proteins. Targeting the contents of exosomes leads to the alteration of host cell behavior. Increasing evidence has indicated that leukemia-derived exosomes could be utilized as prognostic, diagnostic, and therapeutic biomarkers for individuals suffering from leukemia. In this regard, the importance of exosomes in terms of initiation and progression of leukemia was underlined in this study.

MicroRNAs and response to therapy in leukemia

A variety of epigenetic factors involved in leukemia pathogenesis. Among various epigenetic factors, microRNAs (miRNAs) have emerged as important players, which affect a sequence of cellular and molecular signaling pathways. Leukemia is known as progressive cancer, which is related to many health problems in the world. It has been shown that the destruction of the blood-forming organs could lead to abnormal effects on the proliferation and development of leukocytes and their precursors. Despite many attempts for approved effective and powerful therapies for patients with leukemia, finding and developing new therapeutic approaches are required. One of the important aspects of leukemia therapy, identification of underlying cellular and molecular mechanisms involved in the pathogenesis of leukemia. Several miRNAs (ie, miR-103, miR-101, mit-7, let-7i, miR-424, miR-27a, and miR-29c) and play major roles in response to therapy in patients with leukemia. miRNAs exert their effects by targeting a variety of targets, which are associated with response to therapy in patients with leukemia. It seems that more understanding about the roles of miRNAs in response to therapy in patients with leukemia could contribute to better treatment of patients with leukemia. Here, for the first time, we summarized various miRNAs, which are involved in response to therapy in the treatment patients with leukemia.

Genetic Modification Strategies to Enhance CAR T Cell Persistence for Patients With Solid Tumors

Immunotherapy with chimeric antigen receptor (CAR) T cells offers a promising method to improve cure rates and decrease morbidities for patients with cancer. In this regard, CD19-specific CAR T cell therapies have achieved dramatic objective responses for a high percent of patients with CD19-positive leukemia or lymphoma. Most patients with solid tumors however, have experienced transient or no benefit from CAR T cell therapies. Novel strategies are therefore needed to improve CAR T cell function for patients with solid tumors. One obstacle for the field is limited CAR T cell persistence after infusion into patients. In this review we highlight genetic engineering strategies to improve CAR T cell persistence for enhancing antitumor activity for patients with solid tumors.

Vaccines for colorectal cancer: an update

Colorectal cancer (CRC) is known as the third most common and fourth leading cancer associated death worldwide. The occurrence of metastasis has remained as a critical challenge in CRC, so that distant metastasis (mostly to the liver) has been manifested in about 20%-25% of patients. Several screening approaches have introduced for detecting CRC in different stages particularly in early stages. The standard treatments for CRC are surgery, chemotherapy and radiotherapy, in alone or combination. Immunotherapy is a set of novel approaches with the aim of remodeling the immune system battle with metastatic cancer cells, such as immunomodulatory monoclonal antibodies (immune checkpoint inhibitors), adoptive cell transfer (ACT) and cancer vaccine. Cancer vaccines are designed to trigger the intense response of immune system to tumor-specific antigens. In two last decades, introduction of new cancer vaccines and designing several clinical trials with vaccine therapy, have been taken into consideration in colon cancer patients. This review will describe the treatment approaches with the special attention to vaccines applied to treat colorectal cancer.

Knockdown of sal-like 4 expression by small interfering RNA induces apoptosis in breast cancer cells

Breast cancer is the most prevalent cancers worldwide and causes a significant amount of deaths annually. Spalt-like transcription factor 4 is known as a transcription factor, which has an important role in the proliferation of cancerous cells. Small interfering RNA (siRNA) is a short-chain molecule of 20 to 25 nucleotides that protrude on two sides of the 3', two nucleotides. In this study, using a specific sequence of siRNA against the sequence of this gene, its activity is investigated in the cell line of breast cancer. The breast cancer cells (MCF-7) were cultured and then, using a specific anti-sal-like 4 (SALL4) siRNA, their toxic doses were determined. Then, the gene is transfected into the cell. Proliferation and expression of the SALL4 and BCL-2 gene were measured using the real-time polymerase chain reaction method. The specific concentration of siRNA IC₅₀ of the SALL4 gene was 40.35 nmole. Gene expression results indicated that the expression of the Bcl-2 gene in the siRNA group was significantly reduced ( P < 0.05). SiRNA can increase the apoptosis of breast cancer cells by reducing the gene expression of SALL4 gene and Bcl-2; it can be used as a novel targeted therapy. This strategy, in addition to increasing the specificity of the drug, also reduces the side effects when compared with conventional chemotherapy.

Chimeric antigen receptor modified T-cells for cancer treatment

T cells engineered with the chimeric antigen receptor (CAR) are rapidly emerging as an important immunotherapy for hematologic malignancies. The anti-cluster of differentiation (CD)19 CAR-T cell therapy has been remarkably successful against refractory/relapsed acute lymphoblastic leukemia (ALL), and a complete remission rate as high as 90% was observed, in both children and adults. Although the achievement of clinical efficacy using CAR-T cell therapy for solid tumors has encountered several obstacles that were associated with the multiple mechanisms contributing to an immunosuppressive microenvironment, investigators are exploring more optimized approaches to improve the efficiency of CAR-T in solid tumors. In addition, cytokine release syndrome (CRS) and neurotoxicity following CAR-T cell therapy can be severe or even fatal; therefore, the management of these toxicities is significant. Herein, we briefly review the structure of CAR-T and some novel CAR designs, the clinical application of CAR-T cell therapies, as well as the assessment and management of toxicities.