CRISPR/Cas9 library screening uncovered methylated PKP2 as a critical driver of lung cancer radioresistance by stabilizing β-catenin

PKP2 induced by YAP/TEAD4 promotes malignant progression of gastric cancer

Gastric cancer (GC) exhibits significant heterogeneity and its prognosis remains dismal. Therefore, it is essential to investigate new approaches for diagnosing and treating GC. Desmosome proteins are crucial for the advancement and growth of cancer. Plakophilin-2 (PKP2), a member of the desmosome protein family, frequently exhibits aberrant expression and is strongly associated with many tumor types' progression. In this study, we found upregulation of PKP2 in GC. Further correlation analysis showed a notable association between increased PKP2 expression and both tumor stage and poor prognosis in individuals diagnosed with gastric adenocarcinoma. In addition, our research revealed that the Yes-associated protein1 (YAP1)/TEAD4 complex could stimulate the transcriptional expression of PKP2 in GC. Elevated PKP2 levels facilitate activation of the AKT/mammalian target of rapamycin signaling pathway, thereby promoting the malignant progression of GC. By constructing a mouse model, we ultimately validated the molecular mechanism and function of PKP2 in GC. Taken together, these discoveries suggest that PKP2, as a direct gene target of YAP/TEAD4 regulation, has the potential to be used as an indication of GC progression and prognosis. PKP2 is expected to be a promising therapeutic target for GC.

CRISPR/Cas9 screenings unearth protein arginine methyltransferase 7 as a novel essential gene in prostate cancer metastasis

Due to the limited effectiveness of current treatments, the survival rate of patients with metastatic castration-resistant prostate cancer (mCRPC) is significantly reduced. Consequently, it is imperative to identify novel therapeutic targets for managing these patients. Since the invasive ability of cells is crucial for establishing and maintaining metastasis, the aim of this study was to identify the essential regulators of invasive abilities of mCRPC cells by conducting two independent high-throughput CRISPR/Cas9 screenings. Furthermore, some of the top hits were validated using siRNA technology, with protein arginine methyltransferase 7 (PRMT7) emerging as the most promising candidate. We demonstrated that its inhibition or depletion via genetic or pharmacological approaches significantly reduces invasive, migratory and proliferative abilities of mCRPC cells in vitro. Moreover, we confirmed that PRMT7 ablation reduces cell dissemination in chicken chorioallantoic membrane and mouse xenograft assays. Molecularly, PRMT7 reprograms the expression of several adhesion molecules by methylating various transcription factors, such as FoxK1, resulting in the loss of adhesion from the primary tumor and increased motility of mCRPC cells. Furthermore, PRMT7 higher expression correlates with tumor aggressivity and poor overall survival in prostate cancer patients. Thus, this study demonstrates that PRMT7 is a potential therapeutic target and potential biomarker for mPCa.

The Emerging Role of Deubiquitinases in Radiosensitivity

Radiation therapy is a primary treatment for cancer, but radioresistance remains a significant challenge in improving efficacy and reducing toxicity. Accumulating evidence suggests that deubiquitinases (DUBs) play a crucial role in regulating cell sensitivity to ionizing radiation. Traditional small-molecule DUB inhibitors have demonstrated radiosensitization effects, and novel deubiquitinase-targeting chimeras (DUBTACs) provide a promising strategy for radiosensitizer development by harnessing the ubiquitin-proteasome system. This review highlights the mechanisms by which DUBs regulate radiosensitivity, including DNA damage repair, the cell cycle, cell death, and hypoxia. Progress on DUB inhibitors and DUBTACs is summarized, and their potential radiosensitization effects are discussed. Developing drugs targeting DUBs appears to be a promising alternative approach to overcoming radioresistance, warranting further research into their mechanisms.

Targeting type I PRMTs as promising targets for the treatment of pulmonary disorders: Asthma, COPD, lung cancer, PF, and PH

Pulmonary disorders, including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), pulmonary hypertension (PH), and lung cancer, seriously impair the quality of lives of patients. A deeper understanding of the occurrence and development of the above diseases may inspire new strategies to remedy the scarcity of treatments. Type I protein arginine methyltransferases (PRMTs) can affect processes of inflammation, airway remodeling, fibroblast proliferation, mitochondrial mass, and epithelial dysfunction through substrate methylation and non-enzymatic activity, thus affecting the occurrence and development of asthma, COPD, lung cancer, PF, and PH. As potential therapeutic targets, inhibitors of type I PRMTs are developed, moreover, representative compounds such as GSK3368715 and MS023 have also been used for early research. Here, we collated structures of type I PRMTs inhibitors and compared their activity. Finally, we highlighted the physiological and pathological associations of type I PRMTs with asthma, COPD, lung cancer, PF, and PH. The developing of type I PRMTs modulators will be beneficial for the treatment of these diseases.

Computational identification and experimental verification of a novel signature based on SARS-CoV-2-related genes for predicting prognosis, immune microenvironment and therapeutic strategies in lung adenocarcinoma patients

Background

Early research indicates that cancer patients are more vulnerable to adverse outcomes and mortality when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nonetheless, the specific attributes of SARS-CoV-2 in lung Adenocarcinoma (LUAD) have not been extensively and methodically examined.

Methods

We acquired 322 SARS-CoV-2 infection-related genes (CRGs) from the Human Protein Atlas database. Using an integrative machine learning approach with 10 algorithms, we developed a SARS-CoV-2 score (Cov-2S) signature across The Cancer Genome Atlas and datasets GSE72094, GSE68465, and GSE31210. Comprehensive multi-omics analysis, including assessments of genetic mutations and copy number variations, was conducted to deepen our understanding of the prognosis signature. We also analyzed the response of different Cov-2S subgroups to immunotherapy and identified targeted drugs for these subgroups, advancing personalized medicine strategies. The expression of Cov-2S genes was confirmed through qRT-PCR, with GGH emerging as a critical gene for further functional studies to elucidate its role in LUAD.

Results

Out of 34 differentially expressed CRGs identified, 16 correlated with overall survival. We utilized 10 machine learning algorithms, creating 101 combinations, and selected the RFS as the optimal algorithm for constructing a Cov-2S based on the average C-index across four cohorts. This was achieved after integrating several essential clinicopathological features and 58 established signatures. We observed significant differences in biological functions and immune cell statuses within the tumor microenvironments of high and low Cov-2S groups. Notably, patients with a lower Cov-2S showed enhanced sensitivity to immunotherapy. We also identified five potential drugs targeting Cov-2S. In vitro experiments revealed a significant upregulation of GGH in LUAD, and its knockdown markedly inhibited tumor cell proliferation, migration, and invasion.

Conclusion

Our research has pioneered the development of a consensus Cov-2S signature by employing an innovative approach with 10 machine learning algorithms for LUAD. Cov-2S reliably forecasts the prognosis, mirrors the tumor's local immune condition, and supports clinical decision-making in tumor therapies.

PRMT1 in human neoplasm: cancer biology and potential therapeutic target

Protein arginine methyltransferase 1 (PRMT1), the predominant type I protein arginine methyltransferase, plays a crucial role in normal biological functions by catalyzing the methylation of arginine side chains, specifically monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA), within proteins. Recent investigations have unveiled an association between dysregulated PRMT1 expression and the initiation and progression of tumors, significantly impacting patient prognosis, attributed to PRMT1's involvement in regulating various facets of tumor cell biology, including DNA damage repair, transcriptional and translational regulation, as well as signal transduction. In this review, we present an overview of recent advancements in PRMT1 research across different tumor types, with a specific focus on its contributions to tumor cell proliferation, metastasis, invasion, and drug resistance. Additionally, we expound on the dynamic functions of PRMT1 during distinct stages of cancer progression, elucidating its unique regulatory mechanisms within the same signaling pathway and distinguishing between its promotive and inhibitory effects. Importantly, we sought to provide a comprehensive summary and analysis of recent research progress on PRMT1 in tumors, contributing to a deeper understanding of its role in tumorigenesis, development, and potential treatment strategies.

Applications of CRISPR screening to lung cancer treatment

Lung cancer is an extremely aggressive and highly prevalent disease worldwide, and it is one of the leading causes of cancer death. Deciphering intrinsic genetic mechanism, finding new targets, and overcoming drug resistance are the key to lung cancer treatment. High-throughput CRISPR screening has been extensively used to obtain the genes related to cancers including lung cancer. This review describes CRISPR/Cas9 or CRISPR/dCas9-based technologies for high-throughput screening. We summarize the applications of CRISPR screening technology in exploring the mechanism of lung cancer development in vivo or in vitro, overcoming drug resistance, improving the effect of immunotherapy, and discovering new therapeutic targets. This review highlights the potential of CRISPR screening in combination with tumor barcoding and high-throughput sequencing (Tuba-seq) to precisely quantify the impact of alterations in many tumor suppressor genes on lung cancer.

Photoreactive Probe-Based Strategy Enables the Specific Identification of the Transient Substrates of Methyltransferase at the Proteome Scale

To decipher the biological function of protein arginine methyltransferases (PRMTs), the identification of their substrate proteins is crucial. However, this is not a trivial task as the stable and strong interacting proteins always prevail over the weak and transient substrate proteins. Herein, we report the development of a novel photoreactive probe-based strategy to identify the substrate proteins of methyltransferases. By applying it to PRMT1, we demonstrate that this strategy can effectively distinguish substrate proteins from other interacting proteins and allows the identification of highly confident substrate proteins. Noteworthily, we found for the first time that hypomethylation of proteins is a prerequisite for efficient capturing of substrate proteins. This study describes the development of a robust chemical proteomics tool for profiling the transient substrates and can be adapted for broad biomedical applications.

PRMT1 and PRMT5: on the road of homologous recombination and non-homologous end joining

DNA double-strand breaks (DSBs) are widely accepted to be the most deleterious form of DNA lesions that pose a severe threat to genome integrity. Two predominant pathways are responsible for repair of DSBs, homologous recombination (HR) and non-homologous end-joining (NHEJ). HR relies on a template to faithfully repair breaks, while NHEJ is a template-independent and error-prone repair mechanism. Multiple layers of regulation have been documented to dictate the balance between HR and NHEJ, such as cell cycle and post-translational modifications (PTMs). Arginine methylation is one of the most common PTMs, which is catalyzed by protein arginine methyltransferases (PRMTs). PRMT1 and PRMT5 are the predominate PRMTs that promote asymmetric dimethylarginine and symmetric dimethylarginine, respectively. They have emerged to be crucial regulators of DNA damage repair. In this review, we summarize current understanding and unaddressed questions of PRMT1 and PRMT5 in regulation of HR and NHEJ, providing insights into their roles in DSB repair pathway choice and the potential of targeting them for cancer therapy.

Review: Mechanisms and perspective treatment of radioresistance in non-small cell lung cancer

Radiotherapy is the major treatment of non-small cell lung cancer (NSCLC). The radioresistance and toxicity are the main obstacles that leading to therapeutic failure and poor prognosis. Oncogenic mutation, cancer stem cells (CSCs), tumor hypoxia, DNA damage repair, epithelial-mesenchymal transition (EMT), and tumor microenvironment (TME) may dominate the occurrence of radioresistance at different stages of radiotherapy. Chemotherapy drugs, targeted drugs, and immune checkpoint inhibitors are combined with radiotherapy to treat NSCLC to improve the efficacy. This article reviews the potential mechanism of radioresistance in NSCLC, and discusses the current drug research to overcome radioresistance and the advantages of Traditional Chinese medicine (TCM) in improving the efficacy and reducing the toxicity of radiotherapy.

Glycolytic Genes Predict Immune Status and Prognosis Non-Small-Cell Lung Cancer Patients with Radiotherapy and Chemotherapy

Background

Non-small-cell lung cancer (NSCLC) is a major health problem that endangers human health. The prognosis of radiotherapy or chemotherapy is still unsatisfactory. This study is aimed at investigating the predictive value of glycolysis-related genes (GRGs) on the prognosis of NSCLC patients with radiotherapy or chemotherapy.

Methods

Download the clinical information and RNA data of NSCLC patients receiving radiotherapy or chemotherapy from TCGA and geo databases and obtain GRGs from MsigDB. The two clusters were identified by consistent cluster analysis, the potential mechanism was explored by KEGG and GO enrichment analyses, and the immune status was evaluated by estimate, TIMER, and quanTIseq algorithms. Lasso algorithm is used to build the corresponding prognostic risk model.

Results

Two clusters with different GRG expression were identified. The high-expression subgroup had poor overall survival. The results of KEGG and GO enrichment analyses suggest that the differential genes of the two clusters are mainly reflected in metabolic and immune-related pathways. The risk model constructed with GRGs can effectively predict the prognosis. The nomogram combined with the model and clinical characteristics has good clinical application potential.

Conclusion

In this study, we found that GRGs are associated with tumor immune status and can assess the prognosis of NSCLC patients receiving radiotherapy or chemotherapy.

Pyroptosis-based risk score predicts prognosis and drug sensitivity in lung adenocarcinoma

Pyroptosis is a recently identified form of programmed cell death; however, its role in lung adenocarcinoma (LUAD) remains unclear. Therefore, we set out to explore the prognostic potential of pyroptosis-related genes in LUAD. The pyroptosis-related risk score (PRRS) was developed by least absolute shrinkage and selection operator Cox regression and multivariate Cox regression. We found that PRRS was an independent prognostic factor for LUAD. LUAD patients in the high-PRRS group showed a significantly shorter overall survival (OS) and enriched in cell proliferation-related pathways. Then pathway enrichment analyses, mutation profile, tumor microenvironment, and drug sensitivity analysis were further studied in PRRS stratified LUAD patients. Tumor purity (TP) analyses revealed that L-PRRS LUAD patients had a lower TP, and patients in L-TP + L-PRRS subgroup had the most prolonged OS. Mutation analyses suggested that the L-PRRS LUAD patients had a lower tumor mutation burden (TMB), and patients in H-TMB + L-PRRS subgroup had the most prolonged OS. Drug sensitivity analyses showed that PRRS was significantly negatively correlated with the sensitivity of cisplatin, besarotene, etc., while it was significantly positively correlated with the sensitivity of kin001-135. Eventually, a nomogram was constructed based on PRRS and clinical characters of LUAD. Overall, the pyroptosis-related signature is helpful for prognostic prediction and in guiding treatment for LUAD patients.

Identification of Novel Regulators of Radiosensitivity Using High-Throughput Genetic Screening

The biological impact of ionizing radiation (IR) on humans depends not only on the physical properties and absorbed dose of radiation but also on the unique susceptibility of the exposed individual. A critical target of IR is DNA, and the DNA damage response is a safeguard mechanism for maintaining genomic integrity in response to the induced cellular stress. Unrepaired DNA lesions lead to various mutations, contributing to adverse health effects. Cellular sensitivity to IR is highly correlated with the ability of cells to repair DNA lesions, in particular coding sequences of genes that affect that process and of others that contribute to preserving genomic integrity. However, accurate profiling of the molecular events underlying individual sensitivity requires techniques with sensitive readouts. Here we summarize recent studies that have used whole-genome analysis and identified genes that impact individual radiosensitivity. Whereas microarray and RNA-seq provide a snapshot of the transcriptome, RNA interference (RNAi) and CRISPR-Cas9 techniques are powerful tools that enable modulation of gene expression and characterizing the function of specific genes involved in radiosensitivity or radioresistance. Notably, CRISPR-Cas9 has altered the landscape of genome-editing technology with its increased readiness, precision, and sensitivity. Identifying critical regulators of cellular radiosensitivity would help tailor regimens that enhance the efficacy of therapeutic treatments and fast-track prediction of clinical outcomes. It would also contribute to occupational protection based on average individual sensitivity, as well as the formulation of countermeasures to the harmful effects of radiation.

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.

Homeobox A1 Facilitates Immune Escape and Alleviates Oxidative Stress in Lung Adenocarcinoma

Objective

Recent studies have demonstrated that homeobox A1 (HOXA1) is upregulated in lung cancer due to RNA modifications (N6-methyladenosine), but the specific function of HOXA1 in lung adenocarcinoma (LUAD) remains indistinct. Herein, we investigated the role of HOXA1 in LUAD biology.

Methods

This study presented pancancer analysis of associations of HOXA1 with prognosis, TMB, and immune checkpoints. The expression of HOXA1 was detected in LUAD and normal tissues with immunohistochemistry and western blot. Through least absolute shrinkage and selection operator (LASSO) analysis, HOXA1-derived gene model was conducted in LUAD. Correlations of HOXA1 with immune cell infiltrations, immune checkpoints, HLAs, and chemotherapeutic sensitivity were evaluated. Colony formation, proliferation, and migration of LUAD cells with si-HOXA1 transfection were investigated, and the effects of HOXA1 on T cell exhaustion were assessed in vitro.

Results

HOXA1 expression was a risk factor of overall survival, disease-specific survival, and progression-free interval of LUAD. HOXA1 exhibited prominent associations with immune cell infiltration, immune checkpoints, and HLAs. HOXA1-derived gene signature reliably and independently predicted LUAD outcomes. Also, high-risk cases presented increased sensitivity to cisplatin, paclitaxel, docetaxel, vinorelbine, and etoposide. HOXA1 knockdown exhibited an inhibitory effect on proliferation and migration abilities of LUAD cells. Silencing HOXA1 weakened the expression of antioxidative stress markers Nrf2/HO-1 and T cell exhaustion marker CD155 in LUAD cells. Moreover, LUAD cells with HOXA1 knockdown enhanced the CD8+ T cell response.

Conclusion

Our data support the oncogenic function and prognostic significance of HOXA1 that facilitates immune escape and alleviates oxidative stress of LUAD.

The Advances in Epigenetics for Cancer Radiotherapy

Cancer is an important factor threatening human life and health; in recent years, its morbidity and mortality remain high and demosntrate an upward trend. It is of great significance to study its pathogenesis and targeted therapy. As the complex mechanisms of epigenetic modification has been increasingly discovered, they are more closely related to the occurrence and development of cancer. As a reversible response, epigenetic modification is of great significance for the improvement of classical therapeutic measures and the discovery of new therapeutic targets. It has become a research focusto explore the multi-level mechanisms of RNA, DNA, chromatin and proteins. As an important means of cancer treatment, radiotherapy has made great progress in technology, methods, means and targeted sensitization after years of rapid development, and even research on radiotherapy based on epigenetic modification is rampant. A series of epigenetic effects of radiation on DNA methylation, histone modification, chromosome remodeling, RNA modification and non-coding RNA during radiotherapy affects the therapeutic effects and prognosis. Starting from the epigenetic mechanism of tumorigenesis, this paper reviews the latest progress in the mechanism of interaction between epigenetic modification and cancer radiotherapy and briefly introduces the main types, mechanisms and applications of epigenetic modifiers used for radiotherapy sensitization in order to explore a more individual and dynamic approach of cancer treatment based on epigenetic mechanism. This study strives to make a modest contribution to the progress of human disease research.

CRISPR based therapeutics: a new paradigm in cancer precision medicine

Background

Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) systems are the latest addition to the plethora of gene-editing tools. These systems have been repurposed from their natural counterparts by means of both guide RNA and Cas nuclease engineering. These RNA-guided systems offer greater programmability and multiplexing capacity than previous generation gene editing tools based on zinc finger nucleases and transcription activator like effector nucleases. CRISPR-Cas systems show great promise for individualization of cancer precision medicine.

Main body

The biology of Cas nucleases and dead Cas based systems relevant for in vivo gene therapy applications has been discussed. The CRISPR knockout, CRISPR activation and CRISPR interference based genetic screens which offer opportunity to assess functions of thousands of genes in massively parallel assays have been also highlighted. Single and combinatorial gene knockout screens lead to identification of drug targets and synthetic lethal genetic interactions across different cancer phenotypes. There are different viral and non-viral (nanoformulation based) modalities that can carry CRISPR-Cas components to different target organs in vivo.

Conclusion

The latest developments in the field in terms of optimization of performance of the CRISPR-Cas elements should fuel greater application of the latter in the realm of precision medicine. Lastly, how the already available knowledge can help in furtherance of use of CRISPR based tools in personalized medicine has been discussed.

Strategies to overcome the main challenges of the use of CRISPR/Cas9 as a replacement for cancer therapy

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated protein 9) shows the opportunity to treat a diverse array of untreated various genetic and complicated disorders. Therapeutic genome editing processes that target disease-causing genes or mutant genes have been greatly accelerated in recent years as a consequence of improvements in sequence-specific nuclease technology. However, the therapeutic promise of genome editing has yet to be explored entirely, many challenges persist that increase the risk of further mutations. Here, we highlighted the main challenges facing CRISPR/Cas9-based treatments and proposed strategies to overcome these limitations, for further enhancing this revolutionary novel therapeutics to improve long-term treatment outcome human health.

Long non-coding RNA HCG11 enhances osteosarcoma phenotypes by sponging miR-1245b-5p that directly inhibits plakophilin 2

Long non-coding RNA (lncRNA) HCG11 can regulate various cancers through the ceRNA network. However, its role in osteosarcoma (OS) remains unknown. The HOS and Saos-2 cell lines were used for in vitro analyses. HCG11 and plakophilin 2 (PKP2) silencers, a miR-1245b-5p mimic, and a miR-1245b-5p inhibitor were utilized for the regulation analysis of lncRNA HCG11, miR-1245b-5p, and PKP2. Cell Counting Kit-8, wound healing, and transwell assays were used for cell proliferation, migration, and invasion analyses, and caspase-3 activity assay was used to measure cell apoptosis. The expression levels of lncRNA HCG11, miR-1245b-5p, and PKP2 were evaluated by quantitative real-time PCR and Western blotting. The distribution of lncRNA HCG11 was assessed using the RNA-FISH assay. The sponging and targeting roles of HCG11 and PKP2 on miR-1245b-5p were confirmed by dual-luciferase reporter analysis. An RNA immunoprecipitation assay was used to assess the binding between lncRNA HCG11 and miRNA-1245b-5p. We found that the lncRNA HCG11 was significantly upregulated in OS. LncRNA HCG11 silencing inhibits OS progression by repressing cell proliferation, migration, and invasion, and promoting cell apoptosis. RNA-FISH analysis indicated that lncRNA HCG11 was located in the cytoplasm. Mechanistic experiments showed that lncRNA HCG11 sponges miR-1245b-5p and negatively regulates miR-1245b-5p expression. Upregulated lncRNA HCG11 promotes proliferation, migration, and invasion, and inhibits apoptosis by inhibiting miR-1245b-5p in OS cells. PKP2 was verified as a target gene of miR-1245b-5p. Upregulated PKP2 promotes proliferation, migration, and invasion, and inhibits apoptosis by inhibiting miR-1245b-5p in OS. In conclusion, the HCG11/miR-1245b-5p/PKP2 axis promotes OS expression by promoting cell proliferation, migration, and invasion, and inhibiting apoptosis.