Generation and characterization of a human oral squamous carcinoma cell line SCC-9 with CRISPR/Cas9-mediated deletion of the p75 neurotrophin receptor

Revitalizing oral cancer research: Crispr-Cas9 technology the promise of genetic editing

This review presents an in-depth analysis of the immense potential of CRISPR-Cas9 technology in revolutionizing oral cancer research. It underscores the inherent limitations of conventional treatments while emphasizing the pressing need for groundbreaking approaches. The unparalleled capability of CRISPR-Cas9 to precisely target and modify specific genes involved in cancer progression heralds a new era in therapeutic intervention. Employing genome-wide CRISPR screens, vulnerabilities in oral cancer cells can be identified, thereby unravelling promising targets for therapeutic interventions. In the realm of oral cancer, the disruptive power of CRISPR-Cas9 manifests through its capacity to perturb genes that are intricately associated with drug resistance, consequently augmenting the efficacy of chemotherapy. To address the challenges that arise, this review diligently examines pertinent issues such as off-target effects, efficient delivery mechanisms, and the ethical considerations surrounding germline editing. Through precise gene editing, facilitated by CRISPR/Cas9, it becomes possible to overcome drug resistance by rectifying mutations, thereby enhancing the efficacy of personalized treatment strategies. This review delves into the prospects of CRISPR-Cas9, illuminating its potential applications in the domains of medicine, agriculture, and biotechnology. It is paramount to emphasize the necessity of ongoing research endeavors and the imperative to develop targeted therapies tailored specifically for oral cancer. By embracing this comprehensive overview, we can pave the way for ground-breaking treatments that instill renewed hope for enhanced outcomes in individuals afflicted by oral cancer.

Bridging the gap between omics research and dental practice

AIM

The burgeoning field of omics research has witnessed exponential growth in both medicine and dentistry. However, despite more than a decade of advancements, clinical dentistry, particularly in Low- and Middle-Income Countries (LMICs), has seen limited progress in integrating omics-based approaches into routine practice. This review aims to provide a comprehensive overview of the integration of omics approaches in dentistry, focusing on the challenges and opportunities for translating research findings into clinical practice.

METHODS

we conducted a literature review using key databases to provide a brief overview of the history of genomics in dentistry. Additionally, we summarised recent breakthroughs in omics relevant to oral health practitioners, emphasising the inadequate translation of omics research into clinical practice.

RESULTS

Despite significant growth in omics research in both medicine and dentistry, its translation into routine clinical practice in dentistry remains limited. We summarise recent breakthroughs in omics and highlight the gap between research advancements and clinical implementation.

DISCUSSION AND CONCLUSION

The integration of omics approaches holds promise for enhancing diagnostics, personalised treatment strategies, and preventive measures in dental practice, ushering in a new era of precision oral healthcare. However, several challenges, including infrastructure limitations, cost-effectiveness, and education gaps, hinder the widespread adoption of omics-based approaches in clinical dentistry. A strong commitment to transforming dentistry is required to embrace this transition. This shift has the potential to revolutionise oral healthcare by advancing precision diagnostics and treatment strategies tailored to individual patient needs.

Generation of Human 293-F Suspension NGFR Knockout Cells Using CRISPR/Cas9 Coupled to Fluorescent Protein Expression

Suspension cells derived from human embryonic kidney cells (HEK 293) are attractive cell lines for retroviral vector production in gene therapeutic development studies and applications. The low-affinity nerve growth factor receptor (NGFR) is a genetic marker frequently used as a reporter gene in transfer vectors to detect and enrich genetically modified cells. However, the HEK 293 cell line and its derivatives endogenously express the NGFR protein. To eradicate the high background NGFR expression in future retroviral vector packaging cells, we here employed the CRISPR/Cas9 system to generate human suspension 293-F NGFR knockout cells. The expression of a fluorescent protein coupled via a 2A peptide motif to the NGFR targeting Cas9 endonuclease enabled the simultaneous depletion of cells expressing Cas9 and remaining NGFR-positive cells. Thus, a pure population of NGFR-negative 293-F cells lacking persistent Cas9 expression was obtained in a simple and easily applicable procedure.

Characterizing genes associated with cancer using the CRISPR/Cas9 system: A systematic review of genes and methodological approaches

The CRISPR/Cas9 system enables a versatile set of genomes editing and genetic-based disease modeling tools due to its high specificity, efficiency, and accessible design and implementation. In cancer, the CRISPR/Cas9 system has been used to characterize genes and explore different mechanisms implicated in tumorigenesis. Different experimental strategies have been proposed in recent years, showing dependency on various intrinsic factors such as cancer type, gene function, mutation type, and technical approaches such as cell line, Cas9 expression, and transfection options. However, the successful methodological approaches, genes, and other experimental factors have not been analyzed. We, therefore, initially considered more than 1,300 research articles related to CRISPR/Cas9 in cancer to finally examine more than 400 full-text research publications. We summarize findings regarding target genes, RNA guide designs, cloning, Cas9 delivery systems, cell enrichment, and experimental validations. This analysis provides valuable information and guidance for future cancer gene validation experiments.

CRISPR/Cas gene-editing technology and its advances in dentistry

A recent discovery of revolutionary Clustered regularly interspaced palindromic repeats (CRISPR) is a gene-editing tool that provides a type of adaptive immunity in prokaryotic organisms, which is currently used as a revolutionizing tool in biomedical research. It has a mechanism of correcting genome errors, turning on/off genes in cells and organisms. Most importantly playing a crucial function in bacterial defence by identifying and destroying Deoxyribonucleic acid (DNA) segments during bacteriophage invasions since the CRISPR-associated protein 9 (Cas9) enzyme recognizes and cleaves invasive DNA sequences complementary to CRISPR. Therefore, researchers employ this biological device to manipulate the genes to develop new therapies to combat systemic diseases. Currently, the most significant advance at the laboratory level is the generation of cell and animal models, functional genomic screens, live images of the cell genome, and defective DNA repairs to find the cure for genetic disorders. Even though this technology has enormous biomedical applications in various sectors, this review will summarize CRISPR/Cas emphasizing both the therapeutic and diagnostic mechanisms developed in the field of dentistry and the promising attempts to transfer this technology to clinical application. Finally, future developments are also described, which proposes to use CRISPR/Cas systems for prospective clinical dentistry applications.

Approaches for Head and Neck Cancer Research - Current Status and the Way Forward

Head and neck cancers (HNCs) are seeing an increasing trend in their prevalence among both genders and are the seventh most common cancer type occurring at the global level. Studies addressing both the cancer cell physiology and individual differences in response to a specific treatment modality should be understood for arriving at effective treatment and management of the HNCs. In this article, we discuss the trends in HNC research and their various approaches starting from 2D in vitro models, which are the traditional experimental materials to recently established Cancer-Tissue Originated Spheroids (CTOS) distinctly contributing towards personalized or precision medicine.

CRISPR/Cas9-Mediated OC-2 Editing Inhibits the Tumor Growth and Angiogenesis of Ovarian Cancer

Ovarian cancer is the leading cancer-related cause of death in women worldwide. It is of great relevance to understand the mechanism responsible for tumor progression and identify unique oncogenesis markers for a higher chance of preventing this malignant disease. The high-expression OC-2 gene has been shown to be a potential candidate for regulating oncogenesis and angiogenesis in ovarian cancer. Hence, we wished to investigate the impact of OC-2 gene on ovarian cancer aggressiveness. CRISPR/Cas9, a gene editing tool, allows for direct ablation of OC-2 at the genomic level, and we successfully generated OC-2 KO cell lines from SKOV3 and CAOV3 cells. In an apoptosis assay, OC-2 KO induced the apoptosis activation of tumor cells, with the up-regulation of Bax/Caspase-8 and the down-regulation of Bcl-2. Consequently, the proliferation, migration, and invasion of OC-2 KO cell lines were significantly inhibited. Assays of qRT-PCR and Western blotting showed that the expression levels of pro-angiogenic growth factors VEGFA, FGF2, HGF, and HIF-1α and the activation of Akt/ERK pathways were significantly down-regulated at the loss of OC-2. In the xenograft model, OC-2 KO potently suppressed the subcutaneous tumor growth, with the inhibition exceeding 56%. The down-regulation of CD31 and relevant pro-angiogenic growth factors were observed in OC-2 KO tumor tissues. Taken together, OC-2 depletion negatively regulated the ovarian cancer progression possibly by apoptosis activation and angiogenesis inhibition. This work revealed a pivotal regulator of apoptosis and angiogenesis networks in ovarian cancer, and we applied the CRISPR/Cas9 system to the transcription factor pathway for developing a broad-acting anti-tumor gene therapy.

Activation of Glucocorticoid Receptor Inhibits the Stem-Like Properties of Bladder Cancer via Inactivating the β-Catenin Pathway

Background: Glucocorticoid receptor (GR) signaling pathway has been shown to involve epithelial -to- mesenchymal transition which was implicated in the regulation of bladder cancer stem cells (CSCs) in our previous study. Herein, we aim to figure out how GR affects the stem-like properties of bladder cancer cells.

Methods: We used dexamethasone (DEX) treatment or gene-knockdown/-knockout techniques to activate or silence the GR pathway, respectively. Then we applied immunohistochemical staining and flow cytometry to assess the associations between the expression levels of GR and a stem cell surface marker CD44. Stem-like properties were assessed by reactive oxygen species (ROS), sphere-formation and side population assays. The expression levels of cancer stem cell-associated molecules were assessed by quantitative PCR and Western blotting. Tumor growth was compared using mouse xenograft models.

Results: In GR-positive bladder cancer cells, DEX significantly reduced the expression of CD44 as well as pluripotency transcription factors including β-catenin and its downstream target (C-MYC, Snail, and OCT-4), the rate of sphere formation, and the proportion of side populations, and induced the intracellular levels of ROS. By contrast, GR silencing in bladder cancer cells showed the opposite effects. In xenograft-bearing mice, GR silencing resulted in the enhancement of tumor growth.

Conclusions: These data suggested that GR activity was inversely associated with the stem-like properties of bladder cancer cells, potentially via inactivating the β-catenin pathway.

CRISPR/Cas9-related technologies in liver diseases: from feasibility to future diversity

Liver diseases are one of the leading causes of mortality in the world, mainly caused by different etiological agents, alcohol consumption, viruses, drug intoxication, and malnutrition. The maturation of gene therapy has heralded new avenues for developing effective interventions for these diseases. Derived from a remarkable microbial defense system, clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins 9 system (CRISPR/Cas9 system) is driving innovative applications from basic biology to biotechnology and medicine. Recently, the mutagenic function of CRISPR/Cas9 system has been widely adopted for genome and disease research. In this review, we describe the development and applications of CRISPR/Cas9 system on liver diseases for research or translational applications, while highlighting challenges as well as future avenues for innovation.

[Development of precancerous lesions of oral mucous membrane diseases and oral cancer animal models]

Precancerous lesions of oral mucous membrane diseases and oral cancer are common diseases in developing countries, especially in South Asia. However, the cancerous mechanism remains unclear, and no efficient treatment and prognosis measure are currently available. Thus, precancerous lesions of the oral mucosa and oral cancer animal models must be identified to further understand their function. In this paper, we systematically review the development of oral mucosal precancerous lesions and oral cancer animal models by referring to related research.

Ginsenoside Rg3 inhibits growth and epithelial-mesenchymal transition of human oral squamous carcinoma cells by down-regulating miR-221

Ginsenoside Rg3, isolated from the roots of Panax ginseng, has been found to exert anti-cancer activity on multiple human cancers. However, there is no any literature available about the effect of Rg3 on oral squamous cell carcinoma (OSCC). This study investigated the possible anti-cancer effects of Rg3 on OSCC, as well as the possible molecular mechanisms. In vitro, cell viability and proliferation were respectively detected by CCK-8 assay and BrdU assay. Cell apoptosis was detected by Annexin V-FITC/PI assay. Cell transfection was used to change the expression of miR-221 and TIMP3. qRT-PCR and western blotting were performed to measure the expression of molecules involving in cell apoptosis, epithelial-mesenchymal transition (EMT) process, PI3K/AKT pathway and MAPK/ERK pathway. In vivo, OSCC orthotopic murine model was established and tumor volumes were measured. We found that Rg3 treatment inhibited viability, proliferation and EMT process of human OSCC SCC-9 and HSC-5 cells, but promoted cell apoptosis. miR-221 was highly expressed in OSCC tissues and cells. Rg3 reduced the expression of miR-221 in OSCC cells. Up-regulation of miR-221 abrogated the effects of Rg3 on SCC-9 and HSC-5 cell viability, proliferation, apoptosis and EMT process. TIMP3 was lowly expressed in OSCC tissues and cells, which was a direct target gene of miR-221. Rg3 inactivated PI3K/AKT and MAPK/ERK pathways in SCC-9 cells by up-regulating TIMP3. In vivo, Rg3 reduced the tumor volume of OSCC orthotopic murine model. In conclusion, Rg3 exerted anti-cancer effects on OSCC might be via down-regulating miR-221, up-regulating TIMP3, and then inactivating PI3K/AKT and MAPK/ERK pathways.

Genome Editing: A New Horizon for Oral and Craniofacial Research

Precise and efficient genetic manipulations have enabled researchers to understand gene functions in disease and development, providing a platform to search for molecular cures. Over the past decade, the unprecedented advancement of genome editing techniques has revolutionized the biological research fields. Early genome editing strategies involved many naturally occurring nucleases, including meganucleases, zinc finger nucleases, and transcription activator-like effector-based nucleases. More recently, the clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nucleases (CRISPR/Cas) system has greatly enriched genetic manipulation methods in conducting research. Those nucleases generate double-strand breaks in the target gene sequences and then utilize DNA repair mechanisms to permit precise yet versatile genetic manipulations. The oral and craniofacial field harbors a plethora of diseases and developmental defects that require genetic models that can exploit these genome editing techniques. This review provides an overview of the genome editing techniques, particularly the CRISPR/Cas9 technique, for the oral and craniofacial research community. We also discuss the details about the emerging applications of genome editing in oral and craniofacial biology.