CRISPR-cas9 genome editing delivery systems for targeted cancer therapy

Nucleic acid drugs: recent progress and future perspectives

High efficacy, selectivity and cellular targeting of therapeutic agents has been an active area of investigation for decades. Currently, most clinically approved therapeutics are small molecules or protein/antibody biologics. Targeted action of small molecule drugs remains a challenge in medicine. In addition, many diseases are considered 'undruggable' using standard biomacromolecules. Many of these challenges however, can be addressed using nucleic therapeutics. Nucleic acid drugs (NADs) are a new generation of gene-editing modalities characterized by their high efficiency and rapid development, which have become an active research topic in new drug development field. However, many factors, including their low stability, short half-life, high immunogenicity, tissue targeting, cellular uptake, and endosomal escape, hamper the delivery and clinical application of NADs. Scientists have used chemical modification techniques to improve the physicochemical properties of NADs. In contrast, modified NADs typically require carriers to enter target cells and reach specific intracellular locations. Multiple delivery approaches have been developed to effectively improve intracellular delivery and the in vivo bioavailability of NADs. Several NADs have entered the clinical trial recently, and some have been approved for therapeutic use in different fields. This review summarizes NADs development and evolution and introduces NADs classifications and general delivery strategies, highlighting their success in clinical applications. Additionally, this review discusses the limitations and potential future applications of NADs as gene therapy candidates.

Genome-wide CRISPR screening identifies the pivotal role of ANKRD42 in colorectal cancer metastasis through EMT regulation

Colorectal cancer (CRC), a pervasive and lethal malignancy of gastrointestinal cancer, imposes significant challenges due to the occurrence of distant metastasis in advanced stages. Understanding the intricate regulatory mechanisms driving CRC distant metastasis is of paramount importance. CRISPR-Cas9 screening has emerged as a powerful tool for investigating tumor initiation and progression. However, its application in studying CRC distant metastasis remains largely unexplored. To establish a model that faithfully recapitulates CRC liver metastasis in patients, we developed an in vivo genome-wide CRISPR-Cas9 screening approach using a spleen-injected liver metastasis mouse model. Through comprehensive screening of a whole-genome sgRNA library, we identified ANKRD42 as a pivotal regulatory gene facilitating CRC liver metastasis. Analysis of the TCGA database and our clinical cohorts unveiled heightened ANKRD42 expression in metastases. At the cellular level, the attenuation of ANKRD42 impaired the migration and invasion processes of tumor cells. In vivo experiments further validated these observations, highlighting the diminished liver metastatic capacity of tumor cells upon ANKRD42 knockdown. To unravel the specific mechanisms by which ANKRD42 regulates CRC distant metastasis, we leveraged patient-derived organoid (PDO) models. Depleting ANKRD42 in PDOs sourced from liver metastases precipitated the downregulation of pivotal genes linked to epithelial-mesenchymal transition (EMT), including CDH2 and SNAI2, thereby effectively suppressing tumor metastasis. This study not only establishes a conceptual framework but also identifies potential therapeutic avenues for advanced-stage distant metastasis in CRC patients.

CRISPR-Cas9 system: a novel and promising era of genotherapy for beta-hemoglobinopathies, hematological malignancy, and hemophilia

Gene therapy represents a significant potential to revolutionize the field of hematology with applications in correcting genetic mutations, generating cell lines and animal models, and improving the feasibility and efficacy of cancer immunotherapy. Compared to different genetic engineering tools, clustered regularly interspaced short palindromic repeats (CRISPR) CRISPR-associated protein 9 (Cas9) emerged as an effective and versatile genetic editor with the ability to precisely modify the genome. The applications of genetic engineering in various hematological disorders have shown encouraging results. Monogenic hematological disorders can conceivably be corrected with single gene modification. Through the use of CRISPR-CAS9, restoration of functional red blood cells and hemostasis factors were successfully attained in sickle cell anemia, beta-thalassemia, and hemophilia disorders. Our understanding of hemato-oncology has been advanced via CRIPSR-CAS9 technology. CRISPR-CAS9 aided to build a platform of mutated genes responsible for cell survival and proliferation in leukemia. Therapeutic application of CRISPR-CAS9 when combined with chimeric antigen receptor (CAR) T cell therapy in multiple myeloma and acute lymphoblastic leukemia was feasible with attenuation of CAR T cell therapy pitfalls. Our review outlines the latest literature on the utilization of CRISPR-Cas9 in the treatment of beta-hemoglobinopathies and hemophilia disorders. We present the strategies that were employed and the findings of preclinical and clinical trials. Also, the review will discuss gene engineering in the field of hemato-oncology as a proper tool to facilitate and overcome the drawbacks of chimeric antigen receptor T cell therapy (CAR-T).

Extracellular vesicles in cancer therapy: Roles, potential application, and challenges

Extracellular vesicles (EVs) have emerged as a novel cell-free strategy for the treatment of many diseases including cancer as they play important roles in cancer development and progression. Considering their natural capacity to facilitate cell-to-cell communication as well as their high physiochemical stability and biocompatibility, EVs serve as superior delivery systems for a wide range of therapeutic agents, including medicines, nanomaterials, nucleic acids, and proteins. Therefore, EVs-based cancer therapy is of greater interest to researchers. Mounting studies indicate that EVs can be improved in efficiency, specificity, and safety for cancer therapy. However, their heterogeneity of physicochemical properties and functions is not fully understood, hindering the achievement of bioactive EVs with high yield and purity. Herein, we paid more attention to the EVs applications and their significance in cancer therapy.

Engineered stem cells by emerging biomedical stratagems

Stem cell therapy holds immense potential as a viable treatment for a widespread range of intractable disorders. As the safety of stem cell transplantation having been demonstrated in numerous clinical trials, various kinds of stem cells are currently utilized in medical applications. Despite the achievements, the therapeutic benefits of stem cells for diseases are limited, and the data of clinical researches are unstable. To optimize tthe effectiveness of stem cells, engineering approaches have been developed to enhance their inherent abilities and impart them with new functionalities, paving the way for the next generation of stem cell therapies. This review offers a detailed analysis of engineered stem cells, including their clinical applications and potential for future development. We begin by briefly introducing the recent advances in the production of stem cells (induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs)). Furthermore, we present the latest developments of engineered strategies in stem cells, including engineered methods in molecular biology and biomaterial fields, and their application in biomedical research. Finally, we summarize the current obstacles and suggest future prospects for engineered stem cells in clinical translations and biomedical applications.

Recent advances in nano/micro systems for improved circulation stability, enhanced tumor targeting, penetration, and intracellular drug delivery: a review

In recent years, nanoparticles (NPs) have been extensively developed as drug carriers to overcome the limitations of cancer therapeutics. However, there are several biological barriers to nanomedicines, which include the lack of stability in circulation, limited target specificity, low penetration into tumors and insufficient cellular uptake, restricting the active targeting toward tumors of nanomedicines. To address these challenges, a variety of promising strategies were developed recently, as they can be designed to improve NP accumulation and penetration in tumor tissues, circulation stability, tumor targeting, and intracellular uptake. In this Review, we summarized nanomaterials developed in recent three years that could be utilized to improve drug delivery for cancer treatments.

CRISPR-Cas9: A Potent Gene-editing Tool for the Treatment of Cancer

The prokaryotic adaptive immune system has clustered regularly interspaced short palindromic repeat. CRISPR-associated protein (CRISPR-Cas) genome editing systems have been harnessed. A robust programmed technique for efficient and accurate genome editing and gene targeting has been developed. Engineered cell therapy, in vivo gene therapy, animal modeling, and cancer diagnosis and treatment are all possible applications of this ground-breaking approach. Multiple genetic and epigenetic changes in cancer cells induce malignant cell growth and provide chemoresistance. The capacity to repair or ablate such mutations has enormous potential in the fight against cancer. The CRISPR-Cas9 genome editing method has recently become popular in cancer treatment research due to its excellent efficiency and accuracy. The preceding study has shown therapeutic potential in expanding our anticancer treatments by using CRISPR-Cas9 to directly target cancer cell genomic DNA in cellular and animal cancer models. In addition, CRISPR-Cas9 can combat oncogenic infections and test anticancer medicines. It may design immune cells and oncolytic viruses for cancer immunotherapeutic applications. In this review, these preclinical CRISPRCas9- based cancer therapeutic techniques are summarised, along with the hurdles and advancements in converting therapeutic CRISPR-Cas9 into clinical use. It will increase their applicability in cancer research.

Synthetic CRISPR/dCas9-KRAB system driven by specific PSA promoter suppresses malignant biological behavior of prostate cancer cells through negative feedback inhibition of PSA expression

PSA is a type of proto-oncogene that is specifically and highly expressed in embryonic and prostate cancer cells, but not expressed in normal prostate tissue cells. The specific expression of prostate-specific antigen (PSA) is found to be related with the conditional transcriptional regulation of its promoter. Clustered regularly interspaced short palindromic repeats (CRISPR)-dCas9-KRAB is a newly developed transcriptional regulatory system that inhibits gene expression by interupting the DNA transcription process. Induction of CRISPR-dCas9-KRAB expression through the PSA promoter may help feedback inhibition of cellular PSA gene expression via single guide RNA (sgRNA), thereby monitoring and suppressing the malignant state of tumor cells. In this study, we examined the transcriptional activity of the PSA promoter in different prostate cancer cells and normal prostate epithelial cells and determined that it is indeed a prostate cancer cell-specific promoter.Then we constructed the CRISPR-dCas9-KRAB system driven by the PSA promoter, which can inhibit PSA gene expression in the prostate cancer cells at the transcriptional level, and therefore supress the malignant growth and migration of prostate cancer cells and promote their apoptosis in vitro. This study provides a potentially effective anti-cancer strategy for gene therapy of prostate cancer.

Targeted large fragment deletion in plants using paired crRNAs with type I CRISPR system

The CRISPR-Cas systems have been widely used as genome editing tools, with type II and V systems typically introducing small indels, and type I system mediating long-range deletions. However, the precision of type I systems for large fragment deletion is still remained to be optimized. Here, we developed a compact Cascade-Cas3 Dvu I-C system with Cas11c for plant genome editing. The Dvu I-C system was efficient to introduce controllable large fragment deletion up to at least 20 kb using paired crRNAs. The paired-crRNAs design also improved the controllability of deletions for the type I-E system. Dvu I-C system was sensitive to spacer length and mismatch, which was benefit for target specificity. In addition, we showed that the Dvu I-C system was efficient for generating stable transgenic lines in maize and rice with the editing efficiency up to 86.67%. Overall, Dvu I-C system we developed here is powerful for achieving controllable large fragment deletions.

Bioorthogonal CRISPR/Cas9-Drug Conjugate: A Combinatorial Nanomedicine Platform

Bioconjugation of proteins can substantially expand the opportunities in biopharmaceutical development, however, applications are limited for the gene editing machinery despite its tremendous therapeutic potential. Here, a self-delivered nanomedicine platform based on bioorthogonal CRISPR/Cas9 conjugates, which can be armed with a chemotherapeutic drug for combinatorial therapy is introduced. It is demonstrated that multi-functionalized Cas9 with a drug and polymer can form self-condensed nanocomplexes, and induce significant gene editing upon delivery while avoiding the use of a conventional carrier formulation. It is shown that the nanomedicine platform can be applied for combinatorial therapy by incorporating the anti-cancer drug olaparib and targeting the RAD52 gene, leading to significant anti-tumor effects in BRCA-mutant cancer. The current development provides a versatile nanomedicine platform for combination treatment of human diseases such as cancer.

CRISPR-based m6A modification and its potential applications in telomerase regulation

Telomerase determines cell lifespan by controlling chromosome stability and cell viability, m⁶A epigenetic modification plays an important role in the regulation of telomerase activity. Using CRISPR epigenome editing to analyze specific m⁶A modification sites in telomerase will provide an important tool for analyzing the molecular mechanism of m⁶A modification regulating telomerase activity. In this review, we clarified the relevant applications of CRISPR system, paid special attention to the regulation of m⁶A modification in stem cells and cancer cells based on CRISPR system, emphasized the regulation of m⁶A modification on telomerase activity, pointed out that m⁶A modification sites regulate telomerase activity, and discussed strategies based on telomerase activity and disease treatment, which are helpful to promote the research of anti-aging and tumor related diseases.

Cancer nanomedicine toward clinical translation: Obstacles, opportunities, and future prospects

With the integration of nanotechnology into the medical field at large, great strides have been made in the development of nanomedicines for tackling different diseases, including cancers. To date, various cancer nanomedicines have demonstrated success in preclinical studies, improving therapeutic outcomes, prolonging survival, and/or decreasing side effects. However, the translation from bench to bedside remains challenging. While a number of nanomedicines have entered clinical trials, only a few have been approved for clinical applications. In this review, we highlight the most recent progress in cancer nanomedicine, discuss current clinical advances and challenges for the translation of cancer nanomedicines, and provide our viewpoints on accelerating clinical translation. We expect this review to benefit the future development of cancer nanotherapeutics specifically from the clinical perspective.

Methods for CRISPR-Cas as Ribonucleoprotein Complex Delivery In Vivo

The efficient delivery of CRISPR-Cas components is still a key and unsolved problem. CRISPR-Cas delivery in the form of a Cas protein+sgRNA (ribonucleoprotein complex, RNP complex), has proven to be extremely effective, since it allows to increase on-target activity, while reducing nonspecific activity. The key point for in vivo genome editing is the direct delivery of artificial nucleases and donor DNA molecules into the somatic cells of an adult organism. At the same time, control of the dose of artificial nucleases is impossible, which affects the efficiency of genome editing in the affected cells. Poor delivery efficiency and low editing efficacy reduce the overall potency of the in vivo genome editing process. Here we review how this problem is currently being solved in scientific works and what types of in vivo delivery methods of Cas9/sgRNA RNPs have been developed.

New Therapeutics for Extracellular Vesicles: Delivering CRISPR for Cancer Treatment

Cancers are defined by genetic defects, which underlines the prospect of using gene therapy in patient care. During the past decade, CRISPR technology has rapidly evolved into a powerful gene editing tool with high fidelity and precision. However, one of the impediments slowing down the clinical translation of CRISPR-based gene therapy concerns the lack of ideal delivery vectors. Extracellular vesicles (EVs) are nano-sized membrane sacs naturally released from nearly all types of cells. Although EVs are secreted for bio-information conveyance among cells or tissues, they have been recognized as superior vectors for drug or gene delivery. Recently, emerging evidence has spotlighted EVs in CRISPR delivery towards cancer treatment. In this review, we briefly introduce the biology and function of the CRISPR system and follow this with a summary of current delivery methods for CRISPR applications. We emphasize the recent progress in EV-mediated CRISPR editing for various cancer types and target genes. The reported strategies for constructing EV-CRISPR vectors, as well as their limitations, are discussed in detail. The review aims to throw light on the clinical potential of engineered EVs and encourage the expansion of our available toolkit to defeat cancer.

Role of exosomal non-coding RNAs from tumor cells and tumor-associated macrophages in the tumor microenvironment

Exosomes have a crucial role in intercellular communication and mediate interactions between tumor cells and tumor-associated macrophages (TAMs). Exosome-encapsulated non-coding RNAs (ncRNAs) are involved in various physiological processes. Tumor-derived exosomal ncRNAs induce M2 macrophage polarization through signaling pathway activation, signal transduction, and transcriptional and post-transcriptional regulation. Conversely, TAM-derived exosomal ncRNAs promote tumor proliferation, metastasis, angiogenesis, chemoresistance, and immunosuppression. MicroRNAs induce gene silencing by directly targeting mRNAs, whereas lncRNAs and circRNAs act as miRNA sponges to indirectly regulate protein expressions. The role of ncRNAs in tumor-host interactions is ubiquitous. Current research is increasingly focused on the tumor microenvironment. On the basis of the "cancer-immunity cycle" hypothesis, we discuss the effects of exosomal ncRNAs on immune cells to induce T cell exhaustion, overexpression of programmed cell death ligands, and create a tumor immunosuppressive microenvironment. Furthermore, we discuss potential applications and prospects of exosomal ncRNAs as clinical biomarkers and drug delivery systems.

Versatile tools of synthetic biology applied to drug discovery and production

Although synthetic biology is an emerging research field, which has come to prominence within the last decade, it already has many practical applications. Its applications cover the areas of pharmaceutical biotechnology and drug discovery, bringing essential novel methods and strategies such as metabolic engineering, reprogramming the cell fate, drug production in genetically modified organisms, molecular glues, functional nucleic acids and genome editing. This review discusses the main avenues for synthetic biology application in pharmaceutical biotechnology. The authors believe that synthetic biology will reshape drug development and drug production to a similar extent as the advances in organic chemical synthesis in the 20th century. Therefore, synthetic biology already plays an essential role in pharmaceutical, biotechnology, which is the main focus of this review.

CRISPR/dCas9 for hepatic fibrosis therapy: implications and challenges

Hepatic fibrosis is a pathological reaction of tissue damage and repair caused by various pathogenic factors acting on liver. At present, there is no effective anti-fibrotic specific therapy. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (dCas9) system is a new generation of gene editing technology. The CRISPR/dCas9 system provides a platform for studying site-specific transcriptional regulation, which has high efficiency in gene transcriptional activation for achieving robust. This system holds promise for hepatic fibrosis therapy via acting on liver fibrosis effector cells. However, there are some challenges associated with this novel technology, such as large structural variants at on-target, off-target sites, and targeted delivery efficiency. In this review, we present the potential implications and describe the challenges of CRISPR/dCas9 system that might be encountered in hepatic fibrosis therapy.

A Cancer Cell Membrane-Derived Biomimetic Nanocarrier for Synergistic Photothermal/Gene Therapy by Efficient Delivery of CRISPR/Cas9 and Gold Nanorods

Bimodal synergistic therapy produces superadditive effect for enhanced therapeutic efficacy. However, how to efficiently and simultaneously deliver several kinds of therapeutic agents is still challenging. A cancer cell membrane-derived nanocarrier (mCas9-sGNRs) is proposed for synergistic photothermal/gene therapy (PTT/GT) by efficient delivery of clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) and gold nanorods (GNRs). In this approach, Cas9 proteins can be efficiently loaded inside the cell membranes (mCas9) by electrostatic interactions. Similarly, single-guide RNAs, which target survivin, can be loaded onto GNRs (sGNRs) through electrostatic interactions and encapsulated by mCas9. As a result, the nanodelivery systems present advantages in biocompatibility, homologous targeting capacity and loading efficiency of cargoes. In addition, significant antitumor effects is achieved by gene editing of survivin which induces anticancer activity and reduces heat tolerance of cancer cells caused by GNRs mediated PTT due to the downregulation of HSP70. These results indicate the nanotherapeutic platform leads to enhanced PTT/GT efficacy. Therefore, this work not only provides a general strategy to construct a versatile nanoplatform for loading and target delivery of several therapeutic cargos but will also be valuable for PTT/GT and other bimodal synergistic therapy.

Generation of an mESC model with a human hemophilia B nonsense mutation via CRISPR/Cas9 technology

BACKGROUND

Hemophilia B is a rare inherited genetic bleeding disorder caused by a deficiency or lack of coagulation factor IX, the gene for which (F9) is located on the X chromosome. Hemophilia B is currently incurable and the standard treatment is coagulation factor replacement therapy. Although gene therapy has the potential to cure hemophilia, significant barriers are still needed to be overcome, e.g., off-target effects and immunoreactivity, so new approaches must be explored. Nonsense mutations account for 8% of all the hemophilia B mutation types and can result in the development of coagulation factor inhibitors. In this study, CRISPR/Cas9 technology was used to construct a mouse embryonic stem cell model with a hemophilia B nonsense mutation (F9 c.223C > T) in humans to investigate the pathogenesis and treatment of nonsense mutations in hemophilia B.

METHODS

First, a donor plasmid with a mutation (F9 c.223 C > T) and sgRNAs were constructed. Second, both the donor plasmid and the px330-sgRNA were electroporated into mouse embryonic stem cell, and the mutant cells were then screened using puromycin and red fluorescence. Third, the mutant cell lines were tested for pluripotency and the ability to differentiate into three layers. Finally, the effect of mutation on gene function was studied in the differentiation system.

RESULTS

The mutant vector and effective sgRNA were constructed, and the mutant cell line was screened. This mutant cell line exhibited pluripotency and the ability to differentiate into three layers. This point mutation affects F9 expression at both the RNA and protein levels in the differentiation system.

CONCLUSIONS

The mutant cell line obtained in the current study had a single-base mutation rather than a base deletion or insertion in the exon, which is more similar to clinical cases. In addition, the mutant has the characteristics of mouse embryonic stem cells, and this point mutation affects F9 gene transcription and translation, which can be used as a disease model for studying the pathogenesis and treatment of hemophilia at the stem cell level.

Establishment of genetic tools for genomic DNA engineering of Halomonas sp. KM-1, a bacterium with potential for biochemical production

Halomonas species are halophilic and alkaliphilic bacteria, which exhibit potential for industrial production of a variety of chemicals, such as polyhydroxyalkanoates and ectoine, by fermentation because of their favorable characteristics, including high-density culturing capacity and low risk of contamination. However, genetic tools to modify the metabolism of Halomonas for suitable fermentation performance are limited. In this study, we developed two independent basic vectors for Halomonas, named pUCpHAw and pHA1AT_32, consisting of ori regions from two plasmids isolated from Halomonas sp. A020, and chloramphenicol- and tetracycline-resistant genes as cloning markers, respectively. These vectors can independently transform and co-transform the Halomonas sp. KM-1 (KM-1). A protein that was highly and constitutively accumulated was identified as a hemolysin coregulated protein (Hcp) based on proteome analysis of KM-1. Using the hcp promoter, various genes, such as phaA and EGFP, were highly expressed. To establish a gene disruption system, the Streptococcus pyogenes cas9 gene and guide RNA for the pyrF gene, a yeast URA3 homologue, were expressed in pUCpHAw and pHA1AT_32, respectively. As a result, gene disruption mutants were isolated based on phenotypes, 5-fluoroorotic acid resistance, and uracil auxotrophy. A combination of KM-1 and these vectors could be a suitable platform for industrial chemical and protein production.

Genome editing and cancer: How far has research moved forward on CRISPR/Cas9?

Cancer accounted for almost ten million deaths worldwide in 2020. Metastasis, characterized by cancer cell invasion to other parts of the body, is the main cause of cancer morbidity and mortality. Therefore, understanding the molecular mechanisms of tumor formation and discovery of potential drug targets are of great importance. Gene editing techniques can be used to find novel drug targets and study molecular mechanisms. In this review, we describe how popular gene-editing methods such as CRISPR/Cas9, TALEN and ZFNs work, and, by comparing them, we demonstrate that CRISPR/Cas9 has superior efficiency and precision. We further provide an overview of the recent applications of CRISPR/Cas9 to cancer research, focusing on the most common cancers such as breast cancer, lung cancer, colorectal cancer, and prostate cancer. We describe how these applications will shape future research and treatment of cancer, and propose new ways to overcome current challenges.

Recent advances in targeted drug delivery systems for resistant colorectal cancer

Colorectal cancer (CRC) is one of the deadliest cancers in the world, the incidences and morality rate are rising and poses an important threat to the public health. It is known that multiple drug resistance (MDR) is one of the major obstacles in CRC treatment. Tumor microenvironment plus genomic instability, tumor derived exosomes (TDE), cancer stem cells (CSCs), circulating tumor cells (CTCs), cell-free DNA (cfDNA), as well as cellular signaling pathways are important issues regarding resistance. Since non-targeted therapy causes toxicity, diverse side effects, and undesired efficacy, targeted therapy with contribution of various carriers has been developed to address the mentioned shortcomings. In this paper the underlying causes of MDR and then various targeting strategies including exosomes, liposomes, hydrogels, cell-based carriers and theranostics which are utilized to overcome therapeutic resistance will be described. We also discuss implication of emerging approaches involving single cell approaches and computer-aided drug delivery with high potential for meeting CRC medical needs.

Emerging therapeutic targets for cerebral edema

INTRODUCTION

Cerebral edema is a key contributor to death and disability in several forms of brain injury. Current treatment options are limited, reactive, and associated with significant morbidity. Targeted therapies are emerging based on a growing understanding of the molecular underpinnings of cerebral edema.

AREAS COVERED

We review the pathophysiology and relationships between different cerebral edema subtypes to provide a foundation for emerging therapies. Mechanisms for promising molecular targets are discussed, with an emphasis on those advancing in clinical trials, including ion and water channels (AQP4, SUR1-TRPM4) and other proteins/lipids involved in edema signaling pathways (AVP, COX2, VEGF, and S1P). Research on novel treatment modalities for cerebral edema [including recombinant proteins and gene therapies] is presented and finally, insights on reducing secondary injury and improving clinical outcome are offered.

EXPERT OPINION

Targeted molecular strategies to minimize or prevent cerebral edema are promising. Inhibition of SUR1-TRPM4 (glyburide/glibenclamide) and VEGF (bevacizumab) are currently closest to translation based on advances in clinical trials. However, the latter, tested in glioblastoma multiforme, has not demonstrated survival benefit. Research on recombinant proteins and gene therapies for cerebral edema is in its infancy, but early results are encouraging. These newer modalities may facilitate our understanding of the pathobiology underlying cerebral edema.

Bio-vehicles of cytotoxic drugs for delivery to tumor specific targets for cancer precision therapy

Abnormal structural and molecular changes in malignant tissues were thoroughly investigated and utilized to target tumor cells, hence rescuing normal healthy tissues and lowering the unwanted side effects as non-specific cytotoxicity. Various ligands for cancer cell specific markers have been uncovered and inspected for directional delivery of the anti-cancer drug to the tumor site, in addition to diagnostic applications. Over the past few decades research related to the ligand targeted therapy (LTT) increased tremendously aiming to treat various pathologies, mainly cancers with well exclusive markers. Malignant tumors are known to induce elevated levels of a variety of proteins and peptides known as cancer "markers" as certain antigens (e.g., Prostate specific membrane antigen "PSMA", carcinoembryonic antigen "CEA"), receptors (folate receptor, somatostatin receptor), integrins (Integrin αvβ3) and cluster of differentiation molecules (CD13). The choice of an appropriate marker to be targeted and the design of effective ligand-drug conjugate all has to be carefully selected to generate the required therapeutic effect. Moreover, since some tumors express aberrantly high levels of more than one marker, some approaches investigated targeting cancer cells with more than one ligand (dual or multi targeting). We aim in this review to report an update on the cancer-specific receptors and the vehicles to deliver cytotoxic drugs, including recent advancements on nano delivery systems and their implementation in targeted cancer therapy. We will discuss the advantages and limitations facing this approach and possible solutions to mitigate these obstacles. To achieve the said aim a literature search in electronic data bases (PubMed and others) using keywords "Cancer specific receptors, cancer specific antibody, tumor specific peptide carriers, cancer overexpressed proteins, gold nanotechnology and gold nanoparticles in cancer treatment" was carried out.

Combination of CRISPR/Cas9 System and CAR-T Cell Therapy: A New Era for Refractory and Relapsed Hematological Malignancies

Chimeric antigen receptor T (CAR-T) cell therapy is the novel treatment strategy for hematological malignancies such as acute lymphoblastic leukemia (ALL), lymphoma and multiple myeloma. However, treatment-related toxicities such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) have become significant hurdles to CAR-T treatment. Multiple strategies were established to alter the CAR structure on the genomic level to improve efficacy and reduce toxicities. Recently, the innovative gene-editing technology-clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated nuclease9 (Cas9) system, which particularly exhibits preponderance in knock-in and knockout at specific sites, is widely utilized to manufacture CAR-T products. The application of CRISPR/Cas9 to CAR-T cell therapy has shown promising clinical results with minimal toxicity. In this review, we summarized the past achievements of CRISPR/Cas9 in CAR-T therapy and focused on the potential CAR-T targets.

Single-Strand Annealing in Cancer

DNA double-strand breaks (DSBs) are among the most serious forms of DNA damage. In humans, DSBs are repaired mainly by non-homologous end joining (NHEJ) and homologous recombination repair (HRR). Single-strand annealing (SSA), another DSB repair system, uses homologous repeats flanking a DSB to join DNA ends and is error-prone, as it removes DNA fragments between repeats along with one repeat. Many DNA deletions observed in cancer cells display homology at breakpoint junctions, suggesting the involvement of SSA. When multiple DSBs occur in different chromosomes, SSA may result in chromosomal translocations, essential in the pathogenesis of many cancers. Inhibition of RAD52 (RAD52 Homolog, DNA Repair Protein), the master regulator of SSA, results in decreased proliferation of BRCA1/2 (BRCA1/2 DNA Repair Associated)-deficient cells, occurring in many hereditary breast and ovarian cancer cases. Therefore, RAD52 may be targeted in synthetic lethality in cancer. SSA may modulate the response to platinum-based anticancer drugs and radiation. SSA may increase the efficacy of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 (CRISPR associated 9) genome editing and reduce its off-target effect. Several basic problems associated with SSA, including its evolutionary role, interplay with HRR and NHEJ and should be addressed to better understand its role in cancer pathogenesis and therapy.