The crosstalk between Wnt/β-catenin signaling pathway with DNA damage response and oxidative stress: Implications in cancer therapy

SENP1 regulates intermittent hypoxia-induced microglia mediated inflammation and cognitive dysfunction via wnt/β-catenin pathway

Obstructive sleep apnea syndrome (OSAS), characterized by repeated narrow or collapse of the upper airway during sleep, resulting in periodic reductions or cessations in ventilation, consequent hypoxia, hypercapnia, increased sympathetic activity and sleep fragmentation, places a serious burden on society and health care. Intermittent hypoxia (IH), which cause central nervous system (CNS) inflammation, and ultimately lead to neuropathy, is thought to be a crucial contributor to cognitive impairment in OSAS. Wnt signaling pathway exerts an important role in the regulation of CNS disorders. Particularly, it may be involved in the regulation of neuroinflammation and cognitive dysfunction. However, its underlying mechanism remains poorly understood. Accumulating evidence demonstrated that Wnt signaling pathway may inhibited in a variety of neurological disorders. Recently studies revealed that SUMOylation was participated in the regulation of neuroinflammation. Members of Wnt/β-catenin pathway may be targets of SUMOylation. In vitro and in vivo molecular biology experiments explored the regulatory mechanism of SUMOylation on Wnt/β-catenin in IH-induced neuroinflammation and neuronal injury, which demonstrated that IH induced the SUMOylation of β-catenin, microglia mediated inflammation and neuronal damage. Moreover, SENP1 regulated the de-SUMOylation of β-catenin, triggered Wnt/β-catenin pathway, and alleviated neuroinflammation and neuronal injury, thus improving IH-related mice cognitive dysfunction.

Mitochondrial metabolism in neural stem cells and implications for neurodevelopmental and neurodegenerative diseases

Mitochondria are cytoplasmic organelles having a fundamental role in the regulation of neural stem cell (NSC) fate during neural development and maintenance.During embryonic and adult neurogenesis, NSCs undergo a metabolic switch from glycolytic to oxidative phosphorylation with a rise in mitochondrial DNA (mtDNA) content, changes in mitochondria shape and size, and a physiological augmentation of mitochondrial reactive oxygen species which together drive NSCs to proliferate and differentiate. Genetic and epigenetic modifications of proteins involved in cellular differentiation (Mechanistic Target of Rapamycin), proliferation (Wingless-type), and hypoxia (Mitogen-activated protein kinase)-and all connected by the common key regulatory factor Hypoxia Inducible Factor-1A-are deemed to be responsible for the metabolic shift and, consequently, NSC fate in physiological and pathological conditions.Both primary mitochondrial dysfunction due to mutations in nuclear DNA or mtDNA or secondary mitochondrial dysfunction in oxidative phosphorylation (OXPHOS) metabolism, mitochondrial dynamics, and organelle interplay pathways can contribute to the development of neurodevelopmental or progressive neurodegenerative disorders.This review analyses the physiology and pathology of neural development starting from the available in vitro and in vivo models and highlights the current knowledge concerning key mitochondrial pathways involved in this process.

Transcriptomic analysis reveals the immune response mechanisms of sea cucumber Apostichopus japonicus under noise stress from offshore wind turbine

As an important form of renewable energy, offshore wind power can effectively reduce dependence on traditional energy sources and decrease carbon emissions. However, operation of wind turbines can generate underwater noise that may have negative impacts on marine benthic organisms in the surrounding area. Sea cucumbers are slow-moving invertebrates that inhabit the ocean, relying on their immune system to adapt to their environment. To evaluate the frequency range of characteristic noise produced by offshore wind turbines, we conducted a field survey. Additionally, we utilized sea cucumbers in simulated experiments to assess their response to the noise produced by offshore wind turbines. We established a control group, a low-frequency noise group simulating offshore wind turbine noise at 125 Hz and 250 Hz, and a high-frequency noise group at 2500 Hz, each lasting for 7 days. Results from measuring immune enzyme activity in the coelomic fluid suggest that noise can reduce the activity of superoxide dismutase enzymes, which may make sea cucumbers more susceptible to oxidative damage caused by free radicals. Exposure to low-frequency noise can have the effect of diminishing the activity of catalase, and this decrease in catalase activity could potentially increase the susceptibility of the sea cucumber's coelom to inflammation. In order to elucidate the hypothetical mechanism of immune response, intestinal tissue was extracted for transcriptome sequencing. The results showed that under 125 Hz low-frequency noise stress, the number of differentially expressed genes was the highest, reaching 1764. Under noise stress, sea cucumber's cell apoptosis and cell motility are reduced, interfering with lipid metabolism process and membrane synthesis. This research provides theoretical support for the environmental safety assessment of offshore wind power construction.

Genes related to heat tolerance in cattle-a review

Heat stress is described as the cumulative detrimental effect caused by an imbalance between heat production within the body and heat dissipation. When cattle are exposed to heat stress with skin surface temperatures exceeding 35 °C, gene networks within and across cells respond to environmental heat loads with both intra and extracellular signals that coordinate cellular and whole-animal metabolism changes to store heat and rapidly increase evaporative heat loss. In this study, we examined evidence from genes known to be associated with heat tolerance (Hsp70, HSF1, HspB8, SOD1, PRLH, ATP1A1, MTOR, and EIF2AK4). This information could serve as valuable resource material for breeding programs aimed at increasing the thermotolerance of cattle.

Crosstalk between Wnt/β-catenin signaling pathway and DNA damage response in cancer: a new direction for overcoming therapy resistance

Wnt signaling plays an important role in regulating the biological behavior of cancers, and many drugs targeting this signaling have been developed. Recently, a series of research have revealed that Wnt signaling could regulate DNA damage response (DDR) which is crucial for maintaining the genomic integrity in cells and closely related to cancer genome instability. Many drugs have been developed to target DNA damage response in cancers. Notably, different components of the Wnt and DDR pathways are involved in crosstalk, forming a complex regulatory network and providing new opportunities for cancer therapy. Here, we provide a brief overview of Wnt signaling and DDR in the field of cancer research and review the interactions between these two pathways. Finally, we also discuss the possibility of therapeutic agents targeting Wnt and DDR as potential cancer treatment strategies.

Buckwheat tartary regulates the Gsk-3β/β-catenin pathway to prevent neurobehavioral impairments in a rat model of surgical menopause

Menopause is a natural aging process characterized by decreased levels of sex hormones in females. Deprivation of estrogen following menopause results in alterations of dendritic arborization of the neuron that leads to neurobehavioral complications. Hormone replacement therapy is in practice to manage postmenopausal conditions but is associated with a lot of adverse effects. In the present study, the efficacy of buckwheat tartary (Fagopyrum tataricum) whole seed extract was investigated against the neurobehavioral complication in middle-aged ovariectomized rats, which mimic the clinical postmenopausal condition. Hydroalcoholic extraction (80% ethanol) was done, and quantification of major marker compounds in the extract was performed using HPLC. Oral treatment of the extract following the critical window period rescued the reconsolidation process of spatial and recognition memory, as well as depression-like behavior. Gene expression analysis disclosed elevated oxidative stress and neuroinflammation that largely disturb the integrity of the blood-brain barrier in ovariectomized rats. Gfap and Pparγ expression also showed reactive astrogliosis in the rats subjected to ovariectomy. The extract treatment reverted the elevated oxidative stress, neuroinflammation and expression of the studied genes. Furthermore, protein expression analysis revealed that Gsk-3β was activated differentially in the brain, as suggested by β-catenin protein expression, which was normalized following the treatment with extract and rescued the altered neurobehavioral process. The results of the current study concluded that Fagopyrum tataricum seed extract is better option to overcome the neurobehavioral complications associated with the menopause.

Liensinine prevents ischemic injury following myocardial infarction via inhibition of Wnt/β‑catenin signaling activation

BACKGROUND

Myocardial infarction (MI) is the leading cause of deaths worldwide, triggering widespread and irreversible damage to the heart. Currently, there are no drugs that can reverse ischemic damage to the myocardium and hence, finding novel therapeutic agents that can limit the extent of myocardial damage following MI is crucial. Liensinine (LSN) is a naturally derived bisbenzylisoquinoline alkaloid that is known to exhibit numerous antioxidative and cardiovascular beneficial effects. However, the role of LSN in MI-induced injury and its underlying mechanisms remain unexplored.

PURPOSE

Our study aims to evaluate the cardioprotective effects of LSN following MI and its underlying molecular mechanisms.

METHODS

We constructed murine models of MI in order to examine the potential cardioprotective effects and mechanisms of LSN in protecting against myocardial ischemic damage both in vivo and in vitro.

RESULTS

Administration with LSN strongly protected against cardiac injuries following MI by decreasing the extent of ischemic damage and improving cardiac function. Additionally, LSN was found to be a potent inhibitor of Wnt/β‑catenin signaling pathway. Hence, the beneficial effects of LSN in preventing oxidative and DNA damage following ischemia was due to its ability to inhibit aberrant activation of Wnt/β‑catenin signaling.

CONCLUSIONS

Our findings reveal for the first time a novel cardioprotective role of LSN during myocardial infarction and most notably, its ability to protect cardiomyocytes against oxidative stress-induced damage via inhibiting Wnt/β-catenin signaling. Our study therefore suggests new therapeutic potential of LSN or plants that contain the natural alkaloid LSN in ischemic heart diseases.

Prediction of immune infiltration and prognosis for patients with urothelial bladder cancer based on the DNA damage repair-related genes signature

Objectives

To analyze the correlations between the expression and effect of DNA damage repair genes and the immune status and clinical outcomes of urothelial bladder cancer (BLCA) patients. In addition, we evaluate the efficacy and value of utilizing the DNA damage repair genes signature as a prognosis model for BLCA.

Methods

Two subtype groups (C1 and C2) were produced based on the varied expression of DNA damage repair genes. Significantly differentiated genes and predicted enriched gene pathways were obtained between the two subtypes. Seven key genes were obtained from the DNA damage repair-related genes and a 7-gene signature prognosis model was established based on the key genes. The efficacy and accuracy of this model in prognosis prediction was evaluated and verified in two independent databases. Also, the difference in biological functions, drug sensitivity, immune infiltration and affinity between the high-risk group and low-risk group was analyzed.

Results

The DNA damage repair gene signature could significantly differentiate the BLCA into two molecular subgroups with varied genetic expression and enriched gene pathways. Seven key genes were screened out from the 232 candidate genes for prognosis prediction and a 7-gene signature prognosis model was established based on them. Two independent patient cohorts (TCGA cohort and GEO cohort) were utilized to validate the efficacy of the prognosis model, which demonstrated an effective capability to differentiate and predict the overall survival of BLCA patients. Also, the high-risk group and low-risk group derived from the 7-gene model exhibited significantly differences in drug sensitivity, immune infiltration status and biological pathways enrichment.

Conclusions

Our established 7-gene signature model based on the DNA damage repair genes could serve as a novel prognosis predictive tool for BLCA. The differentiation of BLCA patients based on the 7-gene signature model may be of great value for the appropriate selection of specific chemotherapy agents and immune-checkpoint blockade therapy administration.

Nrf2 Modulation in Breast Cancer

Reactive oxygen species (ROS) are identified to control the expression and activity of various essential signaling intermediates involved in cellular proliferation, apoptosis, and differentiation. Indeed, ROS represents a double-edged sword in supporting cell survival and death. Many common pathological processes, including various cancer types and neurodegenerative diseases, are inflammation and oxidative stress triggers, or even initiate them. Keap1-Nrf2 is a master antioxidant pathway in cytoprotective mechanisms through Nrf2 target gene expression. Activation of the Nfr2 pathway benefits cells in the early stages and reduces the level of ROS. In contrast, hyperactivation of Keap1-Nrf2 creates a context that supports the survival of both healthy and cancerous cells, defending them against oxidative stress, chemotherapeutic drugs, and radiotherapy. Considering the dual role of Nrf2 in suppressing or expanding cancer cells, determining its inhibitory/stimulatory position and targeting can represent an impressive role in cancer treatment. This review focused on Nrf2 modulators and their roles in sensitizing breast cancer cells to chemo/radiotherapy agents.

Identification and Validation of a DNA Damage Repair-Related Signature for Diffuse Large B-Cell Lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma in adults, whose prognostic scoring system remains to be improved. Dysfunction of DNA repair genes is closely associated with the development and prognosis of diffuse large B-cell lymphoma. The aim of this study was to establish and validate a DNA repair-related gene signature associated with the prognosis of DLBCL and to investigate the clinical predictive value of this signature.

METHODS

DLBCL cases were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. One hundred ninety-nine DNA repair-related gene sets were retrieved from the GeneCards database. The LASSO Cox regression was used to generate the DNA repair-related gene signature. Subsequently, the level of immune cell infiltration and the correlation between the gene signature and immune cells were analyzed using the CIBERSORT algorithm. Based on the Genomics of Drug Sensitivity in Cancer (GDSC) database, the relationship between the signature and drug sensitivity was analyzed, and together with the nomogram and gene set variation analysis (GSVA), the value of the signature for clinical application was evaluated.

RESULTS

A total of 14 DNA repair genes were screened out and included in the final risk model. Subgroup analysis of the training and validation cohorts showed that the risk model accurately predicted overall survival of DLBCL patients, with patients in the high-risk group having a worse prognosis than patients in the low-risk group. Subsequently, the risk score was confirmed as an independent prognostic factor by multivariate analysis. Furthermore, by CIBERSORT analysis, we discovered that immune cells, such as regulatory T cells (Tregs), activated memory CD4+ T cells, and gamma delta T cells showed significant differences between the high- and low-risk groups. In addition, we found some interesting associations of our signature with immune checkpoint genes (CD96, TGFBR1, and TIGIT). By analyzing drug sensitivity data in the GDSC database, we were able to identify potential therapeutics for DLBCL patients stratified according to our signature.

CONCLUSIONS

Our study identified and validated a 14-DNA repair-related gene signature for stratification and prognostic prediction of DLBCL patients, which might guide clinical personalization of treatment.

Alteration in Wnt signaling mediates induction of transgenerational toxicity of polystyrene nanoplastics in C. elegans

Polystyrene nanoparticles (PS-NPs) have a potential toxicity on offspring after the exposure. However, the molecular basis for PS-NP in inducing transgenerational toxicity remains largely unknown. In this study, the role and the underlying mechanism of germline Wnt signaling in regulating transgenerational toxicity of PS-NPs were determined using an in vivo animal model of Caenorhabditis elegans. Exposure to PS-NP (1-100 μg/L) increased expression of Wnt ligand LIN-44 and decreased expression of Wnt receptor MIG-1. After the exposure, the transgenerational PS-NP toxicity on locomotion behavior and brood size were inhibited in lin-44(RNAi) nematodes, while enhanced in mig-1(RNAi) nematodes. The resistance to transgenerational PS-NP toxicity induced by RNAi of lin-44 in P0 generation (P0-G) was inhibited by RNAi of mig-1 in F1-G. In addition, after PS-NP exposure, germline RNAi of lin-44 at P0-G could increase the mig-1 expression in F1-G. Exposure to PS-NP (1-100 μg/L) further decreased expressions of Dishevelled proteins of DSH-1/2, increased APC complex component APR-1, and decreased expression of BAR-1/β-catenin. Meanwhile, transgenerational PS-NP toxicity was enhanced by RNAi of dsh-1, dsh-2, or bar-1 and inhibited by RNAi of apr-1, suggesting that the DSH-1/2-APR-1-BAR-1 signaling cascade acted downstream of Wnt receptor MIG-1 to control transgenerational PS-NP toxicity. Moreover, BAR-1 acted upstream of DVE-1 to activate mitochondrial unfolded protein response (mt UPR) against the transgenerational PS-NP toxicity. Our data highlights the potential link between alteration in germline Wnt signaling and induction of transgenerational nanoplastic toxicity in organisms.

NEK2 Serves as a Novel Biomarker and Enhances the Tumorigenicity of Clear-CellRenal-Cell Carcinoma by Activating WNT/β-Catenin Pathway

Objective. Currently, cumulative evidence has shown that loss of NEK2 function suppresses tumor growth. However, complete studies on the regulatory role of NEK2 in clear-cellrenal-cell carcinoma (ccRCC) are rarely reported. Methods. The GEPIA database was used for information mining to analyze the gene expression differences between ccRCC tumor and normal tissues. At the same time, we analyzed the protein expression of NEK2 in clinical ccRCC samples and ccRCC cell lines. We detected the effect of NEK2 on the biological behavior of ccRCC at the cell level and further verified the biological effect of NEK2 on ccRCC cells in vivo by nude mouse tumorigenesis experiment. The expression of WNT/β-cateninpathway-related proteins and downstream proteins related to cell function were detected by Western blotting. Results. Using the GEPIA database, we observed that NEK2 expression level in ccRCC tissues was significantly higher than that in normal kidney tissues and was also related to tumor grade. The survival time of patients with ccRCC with high NEK2 expression was shorter than that of patients with low NEK2 expression. Compared with adjacent carcinoma and normal renal tubular epithelial cells, NEK2 levels were highly expressed in ccRCC tissues and ccRCC cell lines. NEK2 interference restrained ccRCC cell growth, migration, and invasion. NEK2 regulated the malignant behavior of ccRCC cells through the WNT/β-catenin pathway. Nude mouse tumorigenesis assay results showed that the transplanted tumors from NEK2 silenced mice grew more slowly and were smaller in size than those from control mice. Conclusions. NEK2 elevation may be associated with poor prognosis in ccRCC, and NEK2 enhances ccRCC cell proliferation, migration, and invasion ability by activating the WNT/β-catenin signaling pathway.

FOXO1 differentially regulates bone formation in young and aged mice

It is a great challenge to develop a safe and effective treatment strategy for age-related osteoporosis and fracture healing. As one of the four FOXO transcription factors, FOXO1 is essential for cell proliferation, survival, senescence, energy metabolism, and oxidative stress in various cells. Our previous study demonstrated that specific Foxo1 gene deletion in osteoblasts in young mice results in bone loss while that in aged mice shows the opposite effect. However, the mechanism underlying the differential regulation of bone metabolism by FOXO1 remains to be elucidated. In this study, we generated osteoblast-specific Foxo1 knockout mice by using Foxo1^fl/fl and Bglap-Cre mice. In young mice, Foxo1 gene deletion inhibits osteoblast differentiation, leading to a decreased osteoblast number and decreased bone formation rate because of the weakened ability to resist oxidative stress, eventually resulting in bone loss and delayed healing of bone defects. In aged mice, high levels of reactive oxygen species (ROS) promote the diversion of CTNNB1 (β-catenin) from T cell factor 4 (TCF4)- to FOXO1-mediated transcription, thereby inhibiting Wnt/β-catenin signaling and leading to decreased osteogenic activity. Conversely, FOXO1 deficiency indirectly promotes the binding of β-catenin and TCF4 and activates Wnt/β-catenin signaling, thereby alleviating age-related bone loss and improving bone defect healing. Our study proves that FOXO1 has differential effects on bone metabolism in young and aged mice and elucidates its underlying mechanism. Further, this study provides a new perspective on the treatment of age-related osteoporosis.

DNA Damage Repair and Current Therapeutic Approaches in Gastric Cancer: A Comprehensive Review

DNA in cells is frequently damaged by endogenous and exogenous agents. However, comprehensive mechanisms to combat and repair DNA damage have evolved to ensure genomic stability and integrity. Improper DNA damage repair may result in various diseases, including some types of tumors and autoimmune diseases. Therefore, DNA damage repair mechanisms have been proposed as novel antitumor drug targets. To date, numerous drugs targeting DNA damage mechanisms have been developed. For example, PARP inhibitors that elicit synthetic lethality are widely used in individualized cancer therapies. In this review, we describe the latent DNA damage repair mechanisms in gastric cancer, the types of DNA damage that can contribute to the development of gastric cancer, and new therapeutic approaches for gastric cancer that target DNA damage repair pathways.

Oxidative Stress: Glutathione and Its Potential to Protect Methionine-35 of Aβ Peptide from Oxidation

Alzheimer's disease (AD) is the most common neurodegenerative disorder with heterogeneous etiology. Intracellular neurofibrillary tangles caused by tau (τ) protein phosphorylation and extracellular senile plaques caused by aggregation of amyloid-beta (Aβ) peptide are characteristic histopathological hallmarks of AD. Oxidative stress (OS) is also suggested to play a role in the pathophysiology of AD. The antioxidant glutathione (GSH) is able to mitigate OS through the detoxification of free radicals. The clearance of these free radicals is reported to be affected when there is a decline in GSH levels in AD. These radicals further react with the methionine-35 (M-35) residue of Aβ and facilitate its subsequent oligomerization. This review presents a plausible model indicating the role of master antioxidant GSH to protect M35 of Aβ_1-40/Aβ_1-42 from oxidation in pathological conditions as compared to healthy controls.

Multi-biomarker approach and IBR index to evaluate the effects of bisphenol A on embryonic stages of zebrafish (Danio rerio)

This study assessed the effects of Bisphenol A in embryonic stages of zebrafish, applying an IBR multi-biomarker approach that included alterations in growth and oxidative status and relates it with the expression of Nrf1, Nrf2, Wnt3a, Wnt8a, COX-2, Qdpra, and DKK1 genes. For this purpose, we exposed zebrafish embryos to eight environmentally relevant concentrations of BPA (220, 380, 540, 700, 860, 1180, 1340, and 1500 ng L^-1) until 96 h post-fertilization. Our results show that BPA induces several malformations in embryos (developmental delay, hypopigmentation, tail malformations, and on), leading to their death. The LC₅₀, EC₅₀ of malformations, and teratogenic index (TI) were 1234.60 ng L^-1, 987.77 ng L^-1, and 1.25, respectively; thus, this emerging contaminant is teratogenic. Regarding oxidative stress and gene expression, we demonstrated BPA altered oxidative status and the gene expression in embryos of Danio rerio.

The Bidirectional Link Between RNA Cleavage and Polyadenylation and Genome Stability: Recent Insights From a Systematic Screen

The integrity of the genome is governed by multiple processes to ensure optimal survival and to prevent the inheritance of deleterious traits. While significant progress has been made to characterize components involved in the DNA Damage Response (DDR), little is known about the interplay between RNA processing and the maintenance of genome stability. Here, we describe the emerging picture of an intricate bidirectional coupling between RNA processing and genome integrity in an integrative manner. By employing insights from a recent large-scale RNAi screening involving the depletion of more than 170 components that direct (alternative) polyadenylation, we provide evidence of bidirectional crosstalk between co-transcriptional RNA 3′end processing and the DDR in a manner that optimizes genomic integrity. We provide instructive examples illustrating the wiring between the two processes and show how perturbations at one end are either compensated by buffering mechanisms at the other end, or even propel the initial insult and thereby become disease-eliciting as evidenced by various disorders.

Mechanisms of acrolein induces toxicity in human umbilical vein endothelial cells: Oxidative stress, DNA damage response, and apoptosis

Acrolein is a ubiquitous environmental pollutant that produced by the incomplete combustion of cigarette smoke, forest fires, petroleum fuels, plastic materials, and cooking fumes. Inhalation is a common form of people exposure to acrolein, increasing evidence demonstrates that acrolein impairs the cardiovascular system by targeting vascular endothelial cells. However, the molecular mechanism of the cytotoxicity of acrolein exposure on vascular endothelial cells remains unclear. This work focused on the toxicity of acrolein on human umbilical vein endothelial cells (HUVECs). The molecular mechanism was studied based on oxidative stress, DNA damage response (DDR), and mitochondrial apoptosis pathways. After HUVECs were treated with 12.5, 25, and 50 μM acrolein for 24 h, cell viability, cell colony formation, mitochondrial membrane potential, and adenosine triphosphate content significantly reduced, and acrolein increased intracellular reactive oxygen species, apoptosis rate, and 8-hydroxy-2 deoxyguanosine (8-OHdG) level. Furthermore, p38MAPK and c-Jun N-terminal kinase signaling pathways were activated in response to oxidative stress. Moreover, acrolein induced G0/G1phase arrest, promoted the expression of γ-H2AX, activated the DDR signaling pathway (Ataxia-Telangiectasia-Mutated [ATM] and Rad-3-related/Chk1 and ATM/Chk2), and triggered the consequent cell cycle checkpoints. Finally, the protein expression of Bax/Bcl-2 and cleaved Caspase-3 was up-regulated, suggesting apoptosis was induced by triggering the mitochondrial apoptosis pathway. All these results indicated that acrolein induced HUVECs cytotoxicity by regulating oxidative stress, DNA damage, and apoptosis. This study provides a novel perspective on the mechanism of acrolein-induced cardiovascular toxicity, it will be helpful for the prevention of acrolein-induced cardiovascular disease.

β-Catenin-Specific Inhibitor, iCRT14, Promotes BoHV-1 Infection-Induced DNA Damage in Human A549 Lung Adenocarcinoma Cells by Enhancing Viral Protein Expression

Oncolytic bovine herpesvirus type 1 (BoHV-1) infection induces DNA damage in human lung adenocarcinoma cell line A549. However, the underlying mechanisms are not fully understood. We found that BoHV-1 infection decreased the steady-state protein levels of p53-binding protein 1 (53BP1), which plays a central role in dictating DNA damage repair and maintaining genomic stability. Furthermore, BoHV-1 impaired the formation of 53BP1 foci, suggesting that BoHV-1 inhibits 53BP1-mediated DNA damage repair. Interestingly, BoHV-1 infection redistributed intracellular β-catenin, and iCRT14 (5-[[2,5-Dimethyl-1-(3-pyridinyl)-1H-pyrrol-3-yl]methylene]-3-phenyl-2,4-thiazolidinedione), a β-catenin-specific inhibitor, enhanced certain viral protein expression, such as the envelope glycoproteins gC and gD, and enhanced virus infection-induced DNA damage. Therefore, for the first time, we provide evidence showing that BoHV-1 infection disrupts 53BP1-mediated DNA damage repair and suggest β-catenin as a potential host factor restricting both virus replication and DNA damage in A549 cells.

Aberrations in the Cross-Talks Among Redox, Nuclear Factor-κB, and Wnt/β-Catenin Pathway Signaling Underpin Myalgic Encephalomyelitis and Chronic Fatigue Syndrome

There is evidence that chronic fatigue spectrum disorders (CFAS-Ds), including myalgic encephalomyelitis (ME), chronic fatigue syndrome (CFS), and chronic fatigue with physiosomatic symptoms including when due to comorbid medical disease, are characterized by neuroimmune and neuro-oxidative biomarkers. This study was performed to delineate the protein-protein interaction (PPI) network of CFAS-D and to discover the pathways, molecular patterns, and domains enriched in their PPI network. We performed network, enrichment, and annotation analyses using differentially expressed proteins and metabolics, which were established in patients with CFAS-D. The PPI network analysis revealed that the backbone of the highly connective CFAS-D network comprises NFKB1, CTNNB1, ALB, peroxides, NOS2, tumor necrosis factor (TNF), and interleukin-6 (IL-6) and that the network comprises interconnected immune-oxidative-nitrosative and Wnt/β-catenin subnetworks. Multiomics enrichment analysis shows that the CFAS-D network is highly significantly associated with cellular (antioxidant) detoxification, hydrogen peroxide metabolic process, peroxidase and oxidoreductase activity, interleukin-10 (IL-10) anti-inflammatory signaling and neurodegenerative canonical Wnt, the β-catenin complex, cadherin domains, cell-cell junctions and TLR2/4 pathways, and the transcription factors nuclear factor kappa B (NF-κB) and RELA. The top 10 DOID annotations of the CFAS-D network include four intestinal, three immune system disorders, cancer, and infectious disease. The custom Gene Ontology (GO) term annotation analysis revealed that the CFAS-D network is associated with a response to a toxic substance, lipopolysaccharides, bacterium, or virus. In conclusion, CFAS-D may be triggered by a variety of stimuli and their effects are mediated by aberrations in the cross-talks between redox, NF-κB, and Wnt/β-catenin signaling pathways leading to dysfunctions in multicellular organismal homeostatic processes.

Toxicity mechanism of acrolein on DNA damage and apoptosis in BEAS-2B cells: Insights from cell biology and molecular docking analyses

Acrolein is a hazardous air pollutant for humans and is responsible for many pulmonary diseases, but the underlying mechanisms have not been completely elucidated. This work is focused on the genotoxicity effects of human bronchial epithelial (BEAS-2B) cells induced by acrolein (20, 40, 80 μM). The molecular mechanism was investigated base on DNA damage and mitochondrial apoptosis pathways. The results showed that after exposure to acrolein, the cell viability, glutathione (GSH) of BEAS-2B cells were reduced. Reactive oxygen species (ROS) level significantly increased, accompanied by increased levels of DNA damage-related indicators 8-hydroxy-2 deoxyguanosine (8-OHdG), DNA content of comet tail (Tail DNA%), olive tail moment (OTM), and nucleus morphology. Cell arrested at the G2/M phase. Then, the DNA damage response (DDR) signaling pathway (Ataxia-telangiectasia-mutated (ATM) and Rad-3-related (ATR)/Chk1 and ATM/Chk2) and the consequent cell cycle checkpoints were activated. The expression of γ-H2AX was significantly increased, indicating that acrolein induced DNA double-strand breaks. Molecular docking assay showed that acrolein bound to DNA in a spontaneous process. Moreover, mitochondrial apoptosis pathway involved in apoptosis, mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) content of BEAS-2B cells were significantly reduced, and the apoptosis rate was significantly increased. The protein expression of Bax/Bcl-2 and Cleaved Caspase-3 were increased, and JNK signaling pathway was activated. All the results indicated that acrolein induced DNA damage, activated DDR and mitochondrial apoptosis pathways, which might be the pivotal factors to mediate cytotoxicity in BEAS-2B cells.

DNA damage response at telomeres boosts the transcription of SARS-CoV-2 receptor ACE2 during aging

The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) causes the coronavirus disease 2019 (COVID‐19), known to be more common in the elderly, who also show more severe symptoms and are at higher risk of hospitalization and death. Here, we show that the expression of the angiotensin converting enzyme 2 (ACE2), the SARS‐CoV‐2 cell receptor, increases during aging in mouse and human lungs. ACE2 expression increases upon telomere shortening or dysfunction in both cultured mammalian cells and in vivo in mice. This increase is controlled at the transcriptional level, and Ace2 promoter activity is DNA damage response (DDR)‐dependent. Both pharmacological global DDR inhibition of ATM kinase activity and selective telomeric DDR inhibition by the use of antisense oligonucleotides prevent Ace2 upregulation following telomere damage in cultured cells and in mice. We propose that during aging telomere dysfunction due to telomeric shortening or damage triggers DDR activation and this causes the upregulation of ACE2, the SARS‐CoV‐2 cell receptor, thus contributing to make the elderly more susceptible to the infection.

Inhibition of SYK and cSrc kinases can protect bone and cartilage in preclinical models of osteoarthritis and rheumatoid arthritis

The pathophysiology of osteoarthritis (OA) includes the destruction of subchondral bone tissue and inflammation of the synovium. Thus, an effective disease-modifying treatment should act on both of these pathogenetic components. It is known that cSrc kinase is involved in bone and cartilage remodeling, and SYK kinase is associated with the inflammatory component. Thus the aim of this study was to characterize the mechanism of action and efficacy of a small molecule multikinase inhibitor MT-SYK-03 targeting SYK and cSrc kinases among others in different in vitro and in vivo arthritis models. The selectivity of MT-SYK-03 kinase inhibition was assayed on a panel of 341 kinases. The compound was evaluated in a set of in vitro models of OA and in vivo OA and RA models: surgically-induced arthritis (SIA), monosodium iodoacetate-induced arthritis (MIA), collagen-induced arthritis (CIA), adjuvant-induced arthritis (AIA). MT-SYK-03 inhibited cSrc and SYK with IC₅₀ of 14.2 and 23 nM respectively. Only five kinases were inhibited > 90% at 500 nM of MT-SYK-03. In in vitro OA models MT-SYK-03 reduced hypertrophic changes of chondrocytes, bone resorption, and inhibited SYK-mediated inflammatory signaling. MT-SYK-03 showed preferential distribution to joint and bone tissue (in rats) and revealed disease-modifying activity in vivo by halving the depth of cartilage erosion in rat SIA model, and increasing the pain threshold in rat MIA model. Chondroprotective and antiresorptive effects were shown in a monotherapy regime and in combination with methotrexate (MTX) in murine and rat CIA models; an immune-mediated inflammation in rat AIA model was decreased. The obtained preclinical data support inhibition of cSrc and SYK as a viable strategy for disease-modifying treatment of OA. A Phase 2 clinical study of MT-SYK-03 is to be started.

Role of haematopoietic cell-specific protein 1-associated protein X-1 gene in lipopolysaccharide-induced apoptosis of human dermal fibroblasts

Wound healing may be disrupted by lipopolysaccharide (LPS)-induced mitochondrial dysfunction, inflammation, and excessive oxidative stress, which can lead to undesirable consequences. The haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) is a mitochondrial matrix protein that regulates mitochondrial function. This study aimed to comprehensively identify the role of HAX-1 in the inhibition of LPS-induced mitochondrial dysfunction and apoptosis in human dermal fibroblasts (HDFs). HAX-1 expression was assessed in the HDF-a cell line using real-time polymerase chain reaction, western blotting, and immunohistochemical staining. The viability, migration, and apoptosis of HDF-a cells were evaluated using the water-soluble tetrazolium-1 assay, transwell assay, and flow cytometry analysis, respectively. Mitochondrial function was evaluated based on reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm). Our results demonstrated that LPS stimulation markedly repressed HAX-1 expression in HDFs and silencing of HAX-1 led to mitochondrial ROS accumulation, ΔΨm disruption, and abnormal mitochondrial morphology. Accordingly, overexpression of HAX-1 or administration of metformin enhanced mitochondrial fusion and normalized mitochondrial dynamics, thereby reversing LPS-induced mitochondrial dysfunction, fibroblast apoptosis, and viability and migration inhibition in HDF-a cells. These data support a mechanism wherein HAX-1 plays a crucial role in LPS-induced fibroblast apoptosis in a mitochondria-dependent manner.

STAT1-Induced Upregulation lncRNA LINC00958 Accelerates the Epithelial Ovarian Cancer Tumorigenesis by Regulating Wnt/β-Catenin Signaling

Background

Growing studies have demonstrated that long noncoding RNAs (lncRNAs) play important roles in tumor progression. In this study, we aimed to explore the potential roles of lncRNA LINC00958 (LINC00958) and its biological functions in epithelial ovarian cancer (EOC).

Methods

The expression of LINC00958 in 11 cases of EOC and adjacent nontumor specimens and five cell lines was detected by qRT-PCR. CCK-8, colony formation, and flow cytometry assays were conducted to study the cell viabilities of EOC cells. Wound scratch and transwell analyses were carried out for the examination of cell invasion and migration of EOC cells. The targeting associations between LINC00958 and STAT1 were demonstrated by ChIP analyses combined with luciferase reporter assays. The related proteins of Wnt/β-catenin signaling were determined using RT-PCR.

Results

Higher levels of LINC00958 were observed in EOC tissues and cell lines. Our data also revealed that high LINC00958 expression was partly induced by STAT1. Functionally, knockdown of LINC00958 suppressed the proliferation, migration, and invasion of EOC cells. Mechanistic investigation showed that the inhibitory effect of LINC00958 knockdown on EOC cells was mediated by the Wnt/β-catenin signaling.

Conclusion

Our findings suggested that STAT1-induced overexpression of LINC00958 promoted EOC progression by modulating Wnt/β-catenin signaling.

Wnt/β-Catenin Pathway in Experimental Model of Fibromyalgia: Role of Hidrox®

Fibromyalgia (FM) is a chronic condition characterized by persistent widespread pain that negatively affects the quality of life of patients. The WNT/β-catenin signaling pathway seems to be involved in central sensitization and different pain states. The objective of this study was to investigate the beneficial effects of a new compound called Hidrox^® (HD), containing 40-50% hydroxytyrosol, in counteracting the pain associated with FM. An FM-like model was induced in rats by subcutaneous injections of reserpine (1 mg/kg) for three consecutive days. Later, HD (10 mg/kg) was administered orally to the animals for seven days. Reserpine injections induced WNT/β-catenin pathway activation, release of pro-inflammatory mediators as well as a significant increase in oxidative stress. Daily treatment with HD was able to modulate the WNT/β-catenin and Nrf2 pathways and consequently attenuate the behavioral deficits and microglia activation induced by reserpine injection. These results indicate that nutritional consumption of HD can be considered as a new therapeutic approach for human FM.

Epigallocatechin gallate and theaflavins independently alleviate cyclophosphamide-induced ovarian damage by inhibiting the overactivation of primordial follicles and follicular atresia

BACKGROUND

Cyclophosphamide (CTX), which has been used to treat common female cancers for several years, often causes ovarian damage, early menopause and infertility. However, strategies for the effective prevention and treatment of CTX-induced ovarian damage are still lacking. Epigallocatechin gallate (EGCG) and theaflavins (TFs), key molecules derived from green tea or black tea, have been shown to exert preventive effects on many ageing-related diseases.

PURPOSE

We aimed to explore the potential preventive and protective effects of EGCG and TFs on CTX-induced ovarian damage and compare the two compounds.

STUDY DESIGN

Six-week-old female mice were administered a low or high dose of EGCG or TFs. The low dose was equivalent to the average daily amount of tea consumed by a drinker.

METHODS

We determined the oestrous cycle and serum hormone levels to evaluate ovarian endocrine function, and we performed mating tests for reproductivity. We also assessed the follicle count and AMH level to evaluate ovarian reserve, and we performed Masson's trichrome and Sirius red staining to evaluate ovarian fibrosis. We conducted γ-H2AX and TUNEL analyses to evaluate DNA damage, and we also measured the relevant indicators of oxidative stress and follicular activation, including NRF2, HO-1, SOD2, AKT, mTOR and RPS6.

RESULTS

EGCG and TFs treatment independently improved the ovarian endocrine function and reproductivity of mice that were administered CTX. EGCG and TFs also increased the ovarian reserve of these animals. Furthermore, EGCG and TFs alleviated oxidation-induced damage to ovarian DNA in mice by activating the NRF2/HO-1 and SOD2 pathways and reducing the apoptosis of growing follicles. At the same time, EGCG and TFs reduced the overactivation of primordial follicles by inhibiting the AKT/mTOR/RPS6 pathway.

CONCLUSION

The present study showed that EGCG and TFs independently improved ovarian function in mice with CTX-induced ovarian damage, thereby providing useful information for designing a potential clinical strategy that will protect against chemotherapy-induced ovarian damage.

Targeting Wnt/β-catenin signaling by microRNAs as a therapeutic approach in chemoresistant osteosarcoma

Osteosarcoma (OS) is an adolescent and young adult malignancy that mostly occurs in long bones. The treatment of OS is still a big challenge for clinicians due to increasing chemoresistance, and many efforts are being made today to find more beneficial treatments. In this regard, the use of microRNAs has shown a high capacity to develop promising therapies. By targeting cancer-involved signaling pathways, microRNAs reduce the cellular level of these protein pathways; thereby reducing the growth and invasion of tumors, and even leading cancer cells to apoptosis. One of these oncogenic pathways that play an important role in OS development and can be targeted by microRNAs is the Wnt/β-catenin signaling pathway. Hence, the first goal of this review article is to explain the cross-talk of microRNAs and the Wnt/β-catenin signaling in OS and then discussing recent findings of the use of microRNAs as a therapeutic approach in OS.

Bisphenol A-induced DNA damages promote to lymphoma progression in human lymphoblastoid cells through aberrant CTNNB1 signaling pathway

Lymphoma is a group of blood cancers that develop from the immune system, and one of the main risk factors is associated with exposure to environmental chemicals. Bisphenol A (BPA) is a common chemical used in the manufacture of materials in polycarbonate and epoxy plastic products and can interfere with the immune system. BPA is considered to possibly induce lymphoma development by affecting the immune system, but its potential mechanisms have not been well established. This study performed a gene-network analysis of microarray data sets in human lymphoma tissues as well as in human cells with BPA exposure to explore module genes and construct the potential pathway for lymphomagenesis in response to BPA. This study provided evidence that BPA exposure resulted in disrupted cell cycle and DNA damage by activating CTNNB1, the initiator of the aberrant constructed CTNNB1-NFKB1-AR-IGF1-TWIST1 pathway, which may potentially lead to lymphomagenesis.

Wnt/β-catenin inhibitor ICG-001 enhances the antitumor efficacy of radiotherapy by increasing radiation-induced DNA damage and improving tumor immune microenvironment in hepatocellular carcinoma

BACKGROUND AND PURPOSE

Radiotherapy (RT) has a promising anti-tumor effect depending on its effects on both cancer cells and tumor immune microenvironment (TIME). As one of the most common alterations in hepatocellular carcinoma (HCC), wnt/β-catenin pathway activation, has been reported to induce radioresistance and suppressive TIME. In this study, we aim to explore the effect of wnt/β-catenin inhibitor ICG-001 on radiosensitivity and RT-related TIME of HCC and the underlying mechanism.

MATERIALS AND METHODS

C57BL/6 and nude mouse tumor models were used to evaluate the efficacy of different treatments on tumor growth, recurrence and mice survival. Flow cytometry was performed to assess tumor infiltrating lymphocytes (TILs). DNA damage response (DDR) and radioresistance was investigated by colony formation assays, γ-H2AX and micronuclei measurements.

RESULTS

The addition of ICG-001 to RT exhibited better anti-tumor and survival-prolong efficacy in C57BL/6 than nude mice. TILs analysis revealed that ICG-001 plus RT boosted the infiltration and IFN-γ production of TIL CD8⁺ T cells, meanwhile reduced the number of Tregs. Moreover, mechanistic study demonstrated that ICG-001 increased the radiation-induced DDR of HCC cells by suppressing p53, thus leading to stronger activation of cGAS/STING pathway. Utilization of cGAS/STING pathway inhibitors impaired the therapeutic effect of combination therapy. Furthermore, combination therapy led to stronger immunologic memory and tumor relapse prevention.

CONCLUSIONS

Our findings showed that ICG-001 displayed both local and systematic effects by increasing radiosensitivity and improving immunity in HCC, which indicated that ICG-001 might be a potential synergetic treatment for radiotherapy and radioimmunotherapy in HCC patients.

Exploring the Potential Mechanism of Costunolide-Induced MCF-7 Cells Apoptosis by Multi-Spectroscopy, Molecular Docking and Cell Experiments

Breast cancer is one of the most common cancer with high morbidity and mortality in women. This study aimed to explore the potential mechanism of costunolide inducing MCF-7 cells apoptosis by multi-spectroscopy, molecular docking, and cell experiments. The results manifested that costunolide interacted with calf thymus DNA (ct-DNA) in a spontaneous manner, and the minor groove as the preferential binding mode. Furthermore, costunolide inhibited cell proliferation and colony formation. Hoechst 33258 staining showed that cell apoptosis induced by costunolide might be related to DNA damage. The apoptosis mechanism relied on regulating the protein expression of Bax, Bcl-2, p53, Caspase-3 and the activation of p38MAPK and nuclear factor κB (NF-κB) pathways. This study will provide some experimental basis and potential therapeutic strategy for breast cancer treatment.

WNT inhibition creates a BRCA-like state in Wnt-addicted cancer

Wnt signaling maintains diverse adult stem cell compartments and is implicated in chemotherapy resistance in cancer. PORCN inhibitors that block Wnt secretion have proven effective in Wnt-addicted preclinical cancer models and are in clinical trials. In a survey for potential combination therapies, we found that Wnt inhibition synergizes with the PARP inhibitor olaparib in Wnt-addicted cancers. Mechanistically, we find that multiple genes in the homologous recombination and Fanconi anemia repair pathways, including BRCA1, FANCD2, and RAD51, are dependent on Wnt/β-catenin signaling in Wnt-high cancers, and treatment with a PORCN inhibitor creates a BRCA-like state. This coherent regulation of DNA repair genes occurs in part via a Wnt/β-catenin/MYBL2 axis. Importantly, this pathway also functions in intestinal crypts, where high expression of BRCA and Fanconi anemia genes is seen in intestinal stem cells, with further upregulation in Wnt-high APCmin mutant polyps. Our findings suggest a general paradigm that Wnt/β-catenin signaling enhances DNA repair in stem cells and cancers to maintain genomic integrity. Conversely, interventions that block Wnt signaling may sensitize cancers to radiation and other DNA damaging agents.

Efficacy and mechanism of the combination of PARP and CDK4/6 inhibitors in the treatment of triple-negative breast cancer

Background

PARP inhibitors (PARPi) benefit only a fraction of breast cancer patients with BRCA mutations, and their efficacy is even more limited in triple-negative breast cancer (TNBC) due to clinical primary and acquired resistance. Here, we found that the efficacy of the PARPi olaparib in TNBC can be improved by combination with the CDK4/6 inhibitor (CDK4/6i) palbociclib.

Methods

We screened primary olaparib-sensitive and olaparib-resistant cell lines from existing BRCA^mut/TNBC cell lines and generated cells with acquired olaparib resistance by gradually increasing the concentration. The effects of the PARPi olaparib and the CDK4/6i palbociclib on BRCA^mut/TNBC cell lines were examined in both sensitive and resistant cells in vitro and in vivo. Pathway and gene alterations were assessed mechanistically and pharmacologically.

Results

We demonstrated for the first time that the combination of olaparib and palbociclib has synergistic effects against BRCA^mut/TNBC both in vitro and in vivo. In olaparib-sensitive MDA-MB-436 cells, the single agent olaparib significantly inhibited cell viability and affected cell growth due to severe DNA damage. In olaparib-resistant HCC1937 and SUM149 cells, single-agent olaparib was ineffective due to potential homologous recombination (HR) repair, and the combination of olaparib and palbociclib greatly inhibited HR during the G2 phase, increased DNA damage and inhibited tumour growth. Inadequate DNA damage caused by olaparib activated the Wnt signalling pathway and upregulated MYC. Further experiments indicated that the overexpression of β-catenin, especially its hyperphosphorylation at the Ser675 site, activated the Wnt signalling pathway and mediated olaparib resistance, which could be strongly inhibited by combined treatment with palbociclib.

Conclusions

Our data provide a rationale for clinical evaluation of the therapeutic synergy of the PARPi olaparib and CDK4/6i palbociclib in BRCA^mut/TNBCs with high Wnt signalling activation and high MYC expression that do not respond to PARPi monotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01930-w.

Down-regulation of long non-coding RNA antisense non-coding RNA in the INK4 locus suppresses OVCAR-3 cells proliferation and induction of apoptosis by Wnt/β -catenin

OBJECTIVES

Ovarian cancer is a lethal gynecological malignancy. Long non-coding RNA antisense non-coding RNA in the INK4 locus (lncRNA ANRIL) was reported to have a critical role in cancer advancement. The ANRIL-mediated oncogenic underlying molecular mechanisms are not fully understood in ovarian cancer. We aimed to study ANRIL silencing effects on the proliferation and apoptosis of OVCAR-3 cells.

METHODS

The ANRIL was Knockdown by transfection of OVCAR-3 cells with si-RNA against ANRIL. MTT assay and cell death ELISA kit were used to evaluate cellular proliferation and apoptosis. The expression levels of ANRIL, pro-and anti-apoptotic genes were assessed using q-RT-PCR. Western blotting was used to assess Wnt/β-catenin signalling pathway.

KEY FINDINGS

ANRIL down-regulating in OVCAR-3 cell lines resulted in significant inhibition of cellular proliferation, apoptosis induction, as well as suppression of cellular invasion. Besides, knockdown of ANRIL led to pro-apoptotic genes up-regulation, Bad and Bax and anti-apoptotic genes down-regulation, Bid and Bcl-2. More importantly, we observed that ANRIL inhibition suppressed the vital components expression of the Wnt/β-catenin cascade.

CONCLUSION

Our findings showed that down-regulation of lncRNA ANRIL resulted in the effective suppression of OVCAR-3 cell proliferation and invasion and induction of apoptosis by preventing Wnt/β-catenin signal transduction.

MiR-139-5p inhibits invasion and migration of gastric cancer cells by targeting PAK5 gene to block Wnt/β-catenin signaling pathway

BACKGROUND

Gastric cancer (GC) is the most common type of cancer of the digestive system. Local or systemic metastasis is the main cause of poor prognosis. MicroRNAs (miRNAs) are an important regulatory factor in the development of gastric cancer. However, the effect and mechanism of miR-139-5p on the invasion and metastasis of gastric cancer cells are still unclear.

AIM

To explore the effect of miR-139-5p on the invasion and migration of gastric cancer cells and the underlying mechanism.

METHODS

Real-time fluorescent quantitative PCR (qRT-PCR) and Western blot were used to detect the expression of miR-139-5p and PAK5, respectively, in immortalized gastric mucosal cell line GES1 and gastric cancer cell lines SGC-7901, AGS, and BGC-823. MiR-139-5p mimic was transfected into gastric cancer SGC-7901 cells, and qRT-PCR was used detect the transfection efficiency. Transwell invasion and scratch assays were used to detect the effect of overexpression of miR-139-5p on the invasion and migration of SGC-7901 cells. Dual luciferase reporter gene assay and Western blot were used to detect the targeted regulation of miR-139-5p on PAK5. Western blot was used to detect the effect of overexpression of miR-139-5p on the activation of Wnt/β-catenin signaling pathway.

RESULTS

The expression level of miR-139-5p in gastric cancer cells was significantly lower than that of normal gastric mucosal cells (P < 0.05), and the expression of PAK5 mRNA and protein was significantly higher than that of normal gastric mucosal cells (P < 0.05). Transfection of miR-139-5p mimic up-regulated the expression of miR-139-5p in SGC-7901 cells. Overexpression of miR-139-5p significantly inhibited the invasion and migration of SGC-7901 cells. The results of dual luciferase reporter gene assay and Western blot showed that miR-139-5p can target and negatively regulate the expression of PAK5. After overexpression of miR-139-5p, the expression of Wnt3a, β-catenin, and Cyclin D1 proteins in SGC-7901 cells was significantly down-regulated.

CONCLUSION

MiR-139-5p inhibits the invasion and migration of gastric cancer cells by targeting the PAK5 gene to block the Wnt/β-catenin signaling pathway.

GTPases, genome, actin: A hidden story in DNA damage response and repair mechanisms

The classical small Rho GTPase (Rho, Rac, and Cdc42) protein family is mainly responsible for regulating cell motility and polarity, membrane trafficking, cell cycle control, and gene transcription. Cumulative recent evidence supports important roles for these proteins in the maintenance of genomic stability. Indeed, DNA damage response (DDR) and repair mechanisms are some of the prime biological processes that underlie several disease phenotypes, including genetic disorders, cancer, senescence, and premature aging. Many reports guided by different experimental approaches and molecular hypotheses have demonstrated that, to some extent, direct modulation of Rho GTPase activity, their downstream effectors, or actin cytoskeleton regulation contribute to these cellular events. Although much attention has been paid to this family in the context of canonical actin cytoskeleton remodeling, here we provide a contextualized review of the interplay between Rho GTPase signaling pathways and the DDR and DNA repair signaling components. Interesting questions yet to be addressed relate to the spatiotemporal dynamics of this collective response and whether it correlates with different subcellular pools of Rho GTPases. We highlight the direct and indirect targets, some of which still lack experimental validation data, likely associated with Rho GTPase activation that provides compelling evidence for further investigation in DNA damage-associated events and with potential therapeutic applications in translational medicine.

Wnt signalling and endocytosis: Mechanisms, controversies and implications for stress responses

Wnt signalling is one of a few conserved pathways that control diverse aspects of development and morphogenesis in all metazoan species. Endocytosis is a key mechanism that regulates the secretion and graded extracellular distribution of Wnt glycoproteins from the source cells, as well as Wnt signal transduction in the receiving cells. However, controversies exist regarding the requirement of clathrin-dependent endocytosis in Wnt signalling. Various lines of evidence from recent studies suggest that Wnt-β-catenin signalling is also involved in the regulation of cellular stress responses in adulthood, a role that is beyond its canonical functions in animal development. In this review, we summarise recent advances in the molecular and cellular mechanisms by which endocytosis modulates Wnt signalling. We also discuss how Wnt signalling could be repurposed to regulate mitochondrial stress response in the nematode Caenorhabditis elegans.

DNA damage response and breast cancer development: Possible therapeutic applications of ATR, ATM, PARP, BRCA1 inhibition

Breast cancer is the most common and significant cancers in females regarding the loss of life quality. Similar to other cancers, one of the etiologic factors in breast cancer is DNA damage. A plethora of molecules are responsible for sensing DNA damage and mediating actions which lead to DNA repair, senescence, cell cycle arrest and if damage is unbearable to apoptosis. In each of these, aberrations leading to unrepaired damage was resulted in uncontrolled proliferation and cancer. Another cellular function is autophagy defined as a process eliminating of unnecessary proteins in stress cases involved in pathogenesis of cancer. Knowing their role in cancer, scholars have tried to develop strategies in order to target DDR and autophagy. Further, the interactions of DDR and autophagy plus their regulatory role on each other have been focused simultaneously. The present review study has aimed to illustrate the importance of DDR and autophagy in breast cancer according to the related studies and uncover the relation between DDR and autophagy and its significance in breast cancer therapy.

NFATC2 Modulates Radiation Sensitivity in Dermal Fibroblasts From Patients With Severe Side Effects of Radiotherapy

Although it is well established that 5 to 15% of radiotherapy patients exhibit severe side-effects in non-cancerous tissues, the molecular mechanisms involved are still poorly known, and the links between cellular and tissue radiosensitivity are still debated. We here studied fibroblasts from non-irradiated skin of patients with severe sequelae of radiotherapy, to determine whether specific basal cell activities might be involved in susceptibility to side-effects in normal tissues. Compared to control cells, patient fibroblasts exhibited higher radiosensitivity together with defects in DNA repair. Transcriptome profiling of dermal fibroblasts from 16 radiotherapy patients with severe side-effects and 8 healthy individuals identified 540 genes specifically deregulated in the patients. Nuclear factor of activated T cells 2 (NFATC2) was the most differentially expressed gene, poorly expressed at both transcript and protein level, whereas the NFATC2 gene region was hypermethylated. Furthermore, NFATC2 expression correlated with cell survival after irradiation. Finally, silencing NFATC2 in normal cells by RNA interference led to increased cellular radiosensitivity and defects in DNA repair. This study demonstrates that patients with clinical hypersensitivity also exhibit intrinsic cellular radiosensitivity in their normal skin cells. It further reveals a new role for NFATC2 as a potential regulator of cellular sensitivity to ionizing radiation.

Oxidative Stress and Cancer Development: Are Noncoding RNAs the Missing Links?

Significance: It is now clear that genetic changes underlie the basis of cancer, and alterations in functions of multiple genes are responsible for the process of tumorigenesis. Besides the classical genes that are usually implicated in cancer, the role of noncoding RNAs (ncRNAs) and reactive oxygen species (ROS) as independent entitites has also been investigated. Recent Advances: The microRNAs and long noncoding RNAs (lncRNAs), two main classes of ncRNAs, are known to regulate many aspects of tumor development. ROS, generated during oxidative stress and pathological conditions, are known to regulate every step of tumor development. Conversely, oxidative stress and ROS producing agents can suppress tumor development. The malignant cells normally produce high levels of ROS compared with normal cells. The interaction between ROS and ncRNAs regulates the expression of multiple genes and pathways implicated in cancer, suggesting a unique mechanistic relationship among ncRNA-ROS-cancer. The mechanistic relationship has been reported in hepatocellular carcinoma, glioma, and malignancies of blood, breast, colorectum, esophagus, kidney, lung, mouth, ovary, pancreas, prostate, and stomach. The ncRNA-ROS regulate several cancer-related cell signaling pathways, namely, protein kinase B (AKT), epidermal growth factor receptor (EGFR), forkhead box O3 (FOXO3), kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), p53, phosphatase and tensin homologue (PTEN), and wingless-related integration site (Wnt)/glycogen synthase kinase-3 beta (GSK3β). Critical Issues: To date, most of the reports about ncRNA-oxidative stress-carcinogenesis relationships are based on cell lines. The mechanistic basis for this relationship has not been completely elucidated. Future Directions: Attempts should be made to explore the association of lncRNAs with ROS. The significance of the ncRNA-oxidative stress-carcinogenesis interplay should also be explored through studies in animal models.

lncRNA VIM‑AS1 promotes cell proliferation, metastasis and epithelial‑mesenchymal transition by activating the Wnt/β‑catenin pathway in gastric cancer

The present study aimed to explore the biological functions and molecular mechanisms of the long non-coding RNA VIM antisense RNA 1 (VIM-AS1) in gastric cancer (GC). The expression of VIM-AS1 was analyzed in tissues from patients with GC and GC cell lines by reverse transcription-quantitative (RT-q)PCR. The relationship between VIM-AS1 expression and overall survival time of patients with GC was also assessed. To determine the biological functions of VIM-AS1, Cell Counting Kit-8 assay, colony formation assay, flow cytometry, wound healing assay and Transwell assay were employed. The targeting relationship among VIM-AS1, microRNA (miR)-8052 and frizzled 1 (FZD1) was verified by the dual luciferase reporter gene assay. The underlying molecular mechanism of VIM-AS1 on GC was determined by RT-qPCR and western blotting. In addition, tumor formation was detected in nude mice. The results of the present study demonstrated that VIM-AS1 was highly expressed in GC tissues and cells. In addition, VIM-AS1 expression was demonstrated to be closely related to the prognosis of patients with GC. Notably, silencing VIM-AS1 inhibited the proliferation, migration and invasion, and enhanced apoptosis of AGS and HGC-27 cells. Silencing VIM-AS1 significantly increased the protein expression levels of cleaved caspase-3, Bax and E-cadherin, but decreased the protein expression levels of Bcl-2, N-cadherin, vimentin, matrix metalloproteinase (MMP)-2, MMP-9, β-catenin, cyclin D1, C-myc and FZD1. Additionally, silencing VIM-AS1 inhibited tumor growth in nude mice. Cumulatively, the present study demonstrated that VIM-AS1 may promote cell proliferation, migration, invasion and epithelial-mesenchymal transition by regulating FDZ1 and activating the Wnt/β-catenin pathway in GC.

Ablation of LGR4 signaling enhances radiation sensitivity of prostate cancer cells

AIM

Our previous study has shown that leucine-rich repeat containing GPCR-4 (LGR4, or GPR48) LGR4 plays a role in cell migration, invasion, proliferation and apoptosis of prostate cancer (PCa). In this study, we aimed to explore whether LGR4 would affect radiation response in PCa.

MATERIALS AND METHODS

LGR4 expression was silenced by shRNA transfection. qRT-PCR was employed to determine mRNA expression of LGR4 and DNA damage repair genes. Western blot was used to evaluate protein expression of LGR4, RSPO1-4, androgen receptor (AR), cyclic AMP response-element binding protein (CREB1), γH2A.X, and H2A.X. Cell proliferation was detected by CCK-8 assay and apoptosis was assayed by flow cytometry. Additionally, a xenograft model was also established to validate the role of LGR4 in PCa cells after radiation.

KEY FINDINGS

LGR4 expression was enhanced in PCa cells by radiation treatment in dose- and time-dependent means. RSPO1-4 were also upregulated post-radiation. Furthermore, LGR4 knockdown exacerbated apoptosis, reduced cell viabilities and strengthened nuclear γH2A.X staining in AR positive PCa cells but not in AR negative cells in the presence of radiation. Likewise, LGR4 ablation diminished AR and CREB1 expression induced by radiation. In contrast, RSPO1 stimulation augmented cell viabilities, promoted AR and CREB1 expression, and upregulated DNA repair gene expression, which could be reversed by enzalutamide, except for AR expression. Additionally, LGR4 knockdown further suppressed tumor growth and AR/CREB1 expression but enhanced γH2A.X expression in xenografts.

SIGNIFICANCE

In all, our study suggested that LGR4 might serve as an important regulator of radiation sensitivity in PCa.

Small subset of Wnt-activated cells is an initiator of regrowth in colorectal cancer organoids after irradiation

Most colorectal cancers (CRCs) are differentiated adenocarcinomas, which maintain expression of both stemness and differentiation markers. This observation suggests that CRC cells could retain a regeneration system of normal cells upon injury. However, the role of stemness in cancer cell regeneration after irradiation is poorly understood. Here, we examined the effect of radiation on growth, stemness, and differentiation in organoids derived from differentiated adenocarcinomas. Following a sublethal dose of irradiation, proliferation and stemness markers, including Wnt target genes, were drastically reduced, but differentiation markers remained. After a static growth phase after high dose of radiation, regrowth foci appeared; these consisted of highly proliferating cells that expressed stem cell markers. Radiosensitivity and the ability to form foci differed among the cancer tissue‐originated spheroid (CTOS) lines examined and showed good correlation with in vivo radiation sensitivity. Pre‐treating organoids with histone deacetylase inhibitors increased radiation sensitivity; this increase was accompanied by the suppression of Wnt signal‐related gene expression. Accordingly, Wnt inhibitors increased organoid radiosensitivity. These results suggested that only a small subset of, but not all, cancer cells with high Wnt activity at the time of irradiation could give rise to foci formation. In conclusion, we established a radiation sensitivity assay using CRC organoids that could provide a novel platform for evaluating the effects of radiosensitizers on differentiated adenocarcinomas in CRC.

Melanocyte Precursors in the Hair Follicle Bulge of Repigmented Vitiligo Skin Are Controlled by RHO-GTPase, KCTD10, and CTNNB1 Signaling

In repigmentation of human vitiligo, the melanocyte (MC) precursors in the hair follicle bulge proliferate, migrate, and differentiate to repopulate the depigmented epidermis. Here, we present a comprehensive characterization of pathways and signals in the bulge that control the repigmentation process. Using biopsies from patients with vitiligo, we have selectively harvested, by laser capture microdissection, MC and keratinocyte precursors from the hair follicle bulge of untreated vitiligo skin and vitiligo skin treated with narrow-band UVB. The captured material was subjected to whole transcriptome RNA-sequencing. With this strategy, we found that repigmentation in the bulge MC precursors is driven by KCTD10, a signal with unknown roles in the skin, and CTNNB1 (encoding β-catenin) and RHO guanosine triphosphatase [RHO GTPase, RHO], two signaling pathways previously shown to be involved in pigmentation biology. Knockdown studies in cultured human MCs of RHOJ, the upmost differentially expressed RHO family component, corroborated with our findings in patients with vitiligo, identified RHOJ involvement in UV response and melanization, and confirmed previously identified roles in melanocytic cell migration and apoptosis. A better understanding of mechanisms that govern repigmentation in MC precursors will enable the discovery of molecules that induce robust repigmentation phenotypes in vitiligo.

Oxygen-releasing manganese clay hybrid complex triggers p53-mediated cancer cell death in hypoxia

Hypoxia in tumor microenvironment is responsible for resistance to conventional modes of cancer therapeutics. A manganese-clay hybrid compound MHC was shown to generate molecular oxygen in aqueous solution. In this study we have shown that MHC, in hypoxia, causes cancer cell death, through release of molecular oxygen and via p53-dependent apoptosis. MHC treatment of cells results in depletion of mitochondrial membrane potential and inhibition of ROS production, in a cell-specific manner. In hypoxia, the oxygen from MHC releases cells from S-phase arrest thus causing p53-dependent apoptosis. The induction of apoptosis by MHC is higher in p53 Wt/Wt cells when it is compared with p53 Mt/Mt cells. The released oxygen from MHC triggers apoptosis via p53 activation through its enhanced homo-oligomerization, post-translational modifications and nuclear localization. Thus MHC as a cellular oxygen-releasing compound has high potential as a drug for hypoxic tumor regression.

Periostin interaction with discoidin domain receptor-1 (DDR1) promotes cartilage degeneration

Osteoarthritis (OA) is characterized by progressive loss of articular cartilage accompanied by the new bone formation and, often, a synovial proliferation that culminates in pain, loss of joint function, and disability. However, the cellular and molecular mechanisms of OA progression and the relative contributions of cartilage, bone, and synovium remain unclear. We recently found that the extracellular matrix (ECM) protein periostin (Postn, or osteoblast-specific factor, OSF-2) is expressed at high levels in human OA cartilage. Multiple groups have also reported elevated expression of Postn in several rodent models of OA. We have previously reported that in vitro Postn promotes collagen and proteoglycan degradation in human chondrocytes through AKT/β-catenin signaling and downstream activation of MMP-13 and ADAMTS4 expression. Here we show that Postn induces collagen and proteoglycan degradation in cartilage by signaling through discoidin domain receptor-1 (DDR1), a receptor tyrosine kinase. The genetic deficiency or pharmacological inhibition of DDR1 in mouse chondrocytes blocks Postn-induced MMP-13 expression. These data show that Postn is signaling though DDR1 is mechanistically involved in OA pathophysiology. Specific inhibitors of DDR1 may provide therapeutic opportunities to treat OA.

Regenerative responses following DNA damage - β-catenin mediates head regrowth in the planarian Schmidtea mediterranea

Pluripotent stem cells hold great potential for regenerative medicine. Increased replication and division, such is the case during regeneration, concomitantly increases the risk of adverse outcomes through the acquisition of mutations. Seeking for driving mechanisms of such outcomes, we challenged a pluripotent stem cell system during the tightly controlled regeneration process in the planarian Schmidtea mediterranea Exposure to the genotoxic compound methyl methanesulfonate (MMS) revealed that despite a similar DNA-damaging effect along the anteroposterior axis of intact animals, responses differed between anterior and posterior fragments after amputation. Stem cell proliferation and differentiation proceeded successfully in the amputated heads, leading to regeneration of missing tissues. Stem cells in the amputated tails showed decreased proliferation and differentiation capacity. As a result, tails could not regenerate. Interference with the body-axis-associated component β-catenin-1 increased regenerative success in tail fragments by stimulating proliferation at an early time point. Our results suggest that differences in the Wnt signalling gradient along the body axis modulate stem cell responses to MMS.