Inhibiting the growth of melanoma cells via hTERT gene editing using CRISPR-dCas9-dnmt3a system

CRISPR/Cas-mediated macromolecular DNA methylation editing: Precision targeting of DNA methyltransferases in cancer therapy

Epigenetic modifications, particularly DNA methylation, play a pivotal role in gene regulation, influencing tumor suppressor silencing and oncogene activation in cancer. DNA methyltransferases (DNMTs), Ten-eleven translocation (TET) enzymes, and associated chromatin regulators are key biological macromolecules that mediate these epigenetic processes. Targeting aberrant DNA methylation holds great promise for cancer therapy, but traditional approaches lack precision and specificity. CRISPR/Cas-based epigenetic editing has emerged as a transformative tool for macromolecular DNA methylation reprogramming, offering targeted modifications without altering the genetic sequence. This review explores the role of DNMTs, TET enzymes, and chromatin-associated proteins in cancer epigenetics and discusses how CRISPR/dCas9 fused with DNMT3A or TET1 enables locus-specific DNA methylation editing. We highlight recent advances, including dCas9-DNMT3A for precise hypermethylation and dCas9-TET1 for targeted demethylation, and discuss their applications in reactivating tumor suppressor genes or silencing oncogenic pathways. Novel epigenetic editing systems, such as SunTag-based amplification, KRAB-MeCP2 repression, further enhance targeting efficiency and therapeutic potential. CRISPR/Cas-mediated macromolecular epigenetic editing represents a paradigm shift in cancer therapy, providing unprecedented control over DNA methylation and chromatin regulation. Despite challenges such as tumor heterogeneity and off-target effects, integrating CRISPR-based methylation reprogramming with precision oncology holds immense promise for future clinical applications.

Comparative RNA sequencing analysis of three Capripoxvirus infections in an immortalized hTERT-bOEC cell model

Capripoxviruses (CaPVs), such as lumpy skin disease, sheep pox, and goat pox, cause significant production and economic losses and are major constraints to the growth of livestock production in endemic areas. Understanding the pathogenic mechanism of CaPVs and their translation into clinical applications depends on the availability of a suitable cell line. In this study, we used a lentiviral packaging system to establish an immortalized hTERT-bOEC cell line by ectopic introduction of human telomerase reverse transcriptase (hTERT). Western blotting, indirect immunofluorescence, and flow cytometry analyses revealed that hTERT was successfully integrated into the genome of hTERT-bOEC cells. Crucially, this hTERT-bOEC cell line was highly susceptible to LSDV, SPPV, and GTPV infections. Establishing hTERT-bOECs is critical for basic research, clinical application, and vaccine development related to CaPVs. Furthermore, RNA-seq analyses revealed a similar differential expression of genes and enrichment of signaling pathways to CaPV infections in hTERT-bOECs. Real-time quantitative qPCR further confirmed the top five up-regulated and down-regulated differentially expressed genes among the CaPV infections. Transcriptome analyses provide deep insight into the biological characteristics of the replication process in CaPV infections.

Macrocyclic Neutralizer to Polybrene via Direct Host-Guest Complexation

Hexadimethrine bromide (HB), a synthetic polycationic species, was introduced to clinical practice as a heparin antidote and recently used in gene therapy. However, HB causes various complications such as severe red blood cells (RBCs) aggregation and tissue damage. Herein, we have synthesized a water-soluble quaterphen[3]arene containing multiple sulfonate moieties (SQP3) as a novel macrocyclic neutralizer to reverse HB via direct host-guest complexation. SQP3 exhibited a robust binding affinity toward HB with a considerably high association constant of (4.73 ± 0.61) × 107 M-1. Co-dosed with 1 equiv of SQP3, HB-induced RBCs aggregation and blood coagulation could be effectively reversed. In vitro cellular assay verified that complexation of HB with SQP3 significantly decreased reactive oxygen species production, thereby suppressing cell apoptosis. In vivo neutralization efficacy studies demonstrated that HB/SQP3 was capable of alleviating related organic damage caused by HB and improving the survival rate of HB-treated mice from 20 to 100%.

Progress and Perspective of CRISPR-Cas9 Technology in Translational Medicine

Translational medicine aims to improve human health by exploring potential treatment methods developed during basic scientific research and applying them to the treatment of patients in clinical settings. The advanced perceptions of gene functions have remarkably revolutionized clinical treatment strategies for target agents. However, the progress in gene editing therapy has been hindered due to the severe off-target effects and limited editing sites. Fortunately, the development in the clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) system has renewed hope for gene therapy field. The CRISPR-Cas9 system can fulfill various simple or complex purposes, including gene knockout, knock-in, activation, interference, base editing, and sequence detection. Accordingly, the CRISPR-Cas9 system is adaptable to translational medicine, which calls for the alteration of genomic sequences. This review aims to present the latest CRISPR-Cas9 technology achievements and prospect to translational medicine advances. The principle and characterization of the CRISPR-Cas9 system are firstly introduced. The authors then focus on recent pre-clinical and clinical research directions, including the construction of disease models, disease-related gene screening and regulation, and disease treatment and diagnosis for multiple refractory diseases. Finally, some clinical challenges including off-target effects, in vivo vectors, and ethical problems, and future perspective are also discussed.

Pan-cancer analysis of G6PD carcinogenesis in human tumors

Glucose-6-phosphate dehydrogenase (G6PD) is involved in the catalytic pentose phosphate pathway (PPP), which is closely related to energy metabolism. G6PD plays a crucial role in many types of cancer, but the specific molecular mechanisms of G6PD in cancer remain unclear. Therefore, we investigated the potential oncogenic role of G6PD in various tumors based on The Cancer Genome Atlas (TCGA), the cBioPortal datasets, the University of California Santa Cruz (UCSC) Xena browser, and the UALCAN-based online tool. G6PD was highly expressed in several cancer tissues (hepatocellular carcinoma, glioma, and breast cancer) compared with normal tissues and was significantly associated with poor prognosis of hepatocellular carcinoma, clear cell renal cell carcinoma, and breast cancer. Promoter methylation levels of G6PD were lower in Bladder Urothelial Carcinoma (BLCA) (P = 2.77e-02), breast invasive carcinoma (BRCA) (P = 1.62e-12), kidney renal clear cell carcinoma (KIRC) (P = 4.23e-02), kidney renal papillary cell carcinoma (KIRP) (P = 2.64e-03), liver hepatocellular carcinoma (LIHC) (P = 1.76e-02), stomach adenocarcinoma (STAD) (P = 3.50e-02), testicular germ cell tumors (TGCT) (P = 1.62e-12), higher in prostate adenocarcinoma (PRAD) (P = 1.81e-09), and uterine corpus endometrial carcinoma (UCEC) (P = 2.96e-04) compared with corresponding normal tissue samples. G6PD expression was positively correlated with the infiltration level of immune cells in most tumors, suggesting that G6PD may be involved in tumor immune infiltration. In addition, the functional mechanism of G6PD also involves 'Carbon metabolism', 'Glycolysis/Gluconeogenesis', 'Pentose phosphate pathway', and 'Central carbon pathway metabolism in cancer signaling pathway'. This pan-cancer study provides a relatively broad understanding of the oncogenic role of G6PD in various tumors and presents a theoretical basis for the development of G6PD inhibitors as therapeutic drugs for multiple cancers.

hTERT Gene Modification Using CRISPR-dCas9-dnmt3a System as a Therapeutic Approach Against Glioma

Background

Abnormal DNA methylation patterns have been reported in various diseases, including different cancers. CRISPR/Cas9 is a low-cost and highly effective gene editing tool that has lately revolutionized biotechnology. Studies have shown that the CRISPR/Cas9 system can effectively target and correct methylation.

Objectives

Telomerase plays a survival role for cancer cells. It is encoded by the hTERT gene. The effectiveness of CRISPR/Cas9 in targeting hTERT to treat glioma cancer cells was assessed in this study.

Methods

EF1a-hsaCas9-U6-gRNA vector carrying sgRNA and Cas9 hybrids were used to transfect U87 glioma cells. Four and eight μg/mL polybrene concentrations were investigated to improve transfection efficiency. The expression level of hTERT that has undergone metabisulfite modification was assessed using real-time PCR. Flow cytometry and Western blotting were also used to determine whether telomerase was present in the cells. High-resolution melting analysis (HRM) was used to examine the hTERT promoter's methylation. Finally, flow cytometry was used to measure the apoptotic rate of transfected U87 cells.

Results

The findings demonstrated that gRNA significantly boosted transfection effectiveness. Significant variations were seen in the expression of hTERT in U87 cells at 4 μg/mL polybrene and 80 μg/mL transfection compared to transfection without gRNA and basal cells. Flow cytometry showed a decrease in hTERT levels in transfected cells. Furthermore, transfection with gRNA increased U87 cell apoptosis compared to transfection without gRNA.

Conclusions

It appears that the designed CRISPR/Cas9 system can reduce hTERT expression and telomerase activity and thus inhibit glioma cell growth.