Senolytic therapeutics: An emerging treatment modality for osteoarthritis

Osteoarthritis (OA), a chronic joint disease affecting millions of people aged over 65 years, is the main musculoskeletal cause of diminished joint mobility in the elderly. It is characterized by lingering pain and increasing deterioration of articular cartilage. Aging and accumulation of senescent cells (SCs) in the joints are frequently associated with OA. Apoptosis resistance; irreversible cell cycle arrest; increased p16INK4a expression, secretion of senescence-associated secretory phenotype factors, senescence-associated β-galactosidase levels, secretion of extracellular vesicles, and levels of reactive oxygen and reactive nitrogen species; and mitochondrial dysregulation are some common changes in cellular senescence in joint tissues. Development of OA correlates with an increase in the density of SCs in joint tissues. Senescence-associated secretory phenotype has been linked to OA and cartilage breakdown. Senolytics and therapeutic pharmaceuticals are being focused upon for OA management. SCs can be selectively eliminated or killed by senolytics to halt the pathogenesis and progression of OA. Comprehensive understanding of how aging affects joint dysfunction will benefit OA patients. Here, we discuss age-related mechanisms associated with OA pathogenesis and senolytics as an emerging modality in the management of age-related SCs and pathogenesis of OA in preclinical and clinical studies.

The scientific basis of 'net zero emissions' and its diverging sociopolitical representation

The Net Zero Emissions (NZE) concept has created momentum for climate commitment made by national governments, cities, industries and individual companies. However, evidence of tangible decarbonisation is limited. Here we identify precarious differences between the scientific origin of NZE and its social representation in the wider public and explore the consequences of the resulting science-action gap for achieving global climate goals. A particular focus is given to 'offsetting', which is closely connected to the practical delivery of NZE but typically ignores that different types or carbon credits have different environmental efficacy. Revisiting the science related to the global carbon cycle demonstrates that a heavy reliance on any carbon offsetting that is not a permanent removal presents a real risk. Moreover, competition over scarce 'removal credits' distracts from the real tasks at hand, namely to rapidly decrease fossil fuel emissions, actively remove carbon through restoration, and protect existing terrestrial carbon sinks. Establishing separate targets for these distinct actions is an essential step towards disentangling current confusion. Whilst a 'race to net zero' may trigger innovation in the decarbonisation space, the restoration and protection of carbon sinks demands a collective approach where actors should focus on how to make real and verifiable contributions rather than claiming individual net zero scores.

Perioperative outcomes of laparoscopic low anterior resection using ArtiSential® versus robotic approach in patients with rectal cancer: a propensity score matching analysis

BACKGROUND

Total mesorectal excision using conventional straight fixed devices may be technically difficult because of the narrow and concave pelvis. Several laparoscopic articulating tools have been introduced as an alternative to robotic systems. The aim of this study was to compare perioperative outcomes between laparoscopic low anterior resection using ArtiSential® and robot-assisted surgery for rectal cancer.

METHODS

This retrospective study included 682 patients who underwent laparoscopic or robotic low anterior resection  for rectal cancer from September 2018 to December 2021. Among them, 82 underwent laparoscopic surgery using ArtiSential® (group A) and 201 underwent robotic surgery (group B). A total of 73 [group A; 66.37 ± 11.62; group B 65.79 ± 11.34] patients were selected for each group using a propensity score matching analysis.

RESULTS

There was no significant difference in the baseline characteristics between group A and B. Mean operative time was longer in group B than A (163.5 ± 61.9 vs 250.1 ± 77.6 min, p < 0.001). Mean length of hospital stay was not significantly different between the two groups (6.2 ± 4.7 vs 6.7 ± 6.1 days, p = 0.617). Postoperative complications, reoperation, and readmission within 30 days after surgery were similar between the two groups. Pathological findings revealed that the circumferential resection margins were above 10 mm in both groups (11.00 ± 7.47 vs 10.17 ± 6.25 mm, p = 0.960). At least 12 lymph nodes were sufficiently harvested, with no significant difference in the number harvested between the groups (20.5 ± 9.9 vs 19.7 ± 7.3, p = 0.753).

CONCLUSIONS

Laparoscopic low anterior resection using ArtiSential® can achieve acceptable clinical and oncologic outcomes. ArtiSential®, a multi-joint and articulating device, may serve a feasible alternative approach to robotic surgery in rectal cancer.

In vitro and in vivo investigations on arsenic-induced cartilage degeneration in osteoarthritis

Heavy metals found in the environment, including arsenic (As) pose significant risks to human health and present a risk factor for osteoarthritis (OA). This study researched the impact of As on cartilage degeneration by focusing on the role of As in causing OA in mice. We employed chemical inhibition and inductively coupled plasma mass spectrometry analyses to identify the effect of As on chondrocytes as well as studying its accumulation in organs after oral administration in mice. Additionally, the study examined the effect of intra-articular As treatment on the levels of crucial catabolic factors, namely Hif-2α (Epas1) and Zip8 (Slc39a8), during OA progression. Mice that were administered As orally in conjunction with surgically induced joint instability, had heightened cartilage destruction compared to wild-type mice. Quantitative analysis revealed a significant increase in Hif-2α and Zip8 mRNA expression (p = 0.0352,0.0004 respectively) and protein expression (p = 0.0101,0.008 respectively) post oral administration. Our findings illustrated the role of As in influencing crucial cellular functions that are triggered by reactive oxygen species. These events consequently activate the Akt/Hif-2α/NF-κB pathways, leading to disruptions in articular cartilage homeostasis. This study provides a comprehensive understanding of the impact of As on the development of osteoarthritis.

Structural basis for ligand recognition and signaling of hydroxy-carboxylic acid receptor 2

Hydroxycarboxylic acid receptors (HCAR1, HCAR2, and HCAR3) transduce Gi/o signaling upon biding to molecules such as lactic acid, butyric acid and 3-hydroxyoctanoic acid, which are associated with lipolytic and atherogenic activity, and neuroinflammation. Although many reports have elucidated the function of HCAR2 and its potential as a therapeutic target for treating not only dyslipidemia but also neuroimmune disorders such as multiple sclerosis and Parkinson's disease, the structural basis of ligand recognition and ligand-induced Gi-coupling remains unclear. Here we report three cryo-EM structures of the human HCAR2-Gi signaling complex, each bound with different ligands: niacin, acipimox or GSK256073. All three agonists are held in a deep pocket lined by residues that are not conserved in HCAR1 and HCAR3. A distinct hairpin loop at the HCAR2 N-terminus and extra-cellular loop 2 (ECL2) completely enclose the ligand. These structures also reveal the agonist-induced conformational changes propagated to the G-protein-coupling interface during activation. Collectively, the structures presented here are expected to help in the design of ligands specific for HCAR2, leading to new drugs for the treatment of various diseases such as dyslipidemia and inflammation.

BRD4/nuclear PD-L1/RelB circuit is involved in the stemness of breast cancer cells

BACKGROUND

Breast cancer (BC) is the most common cancer diagnosed in women worldwide. BC stem cells (BCSCs) have been known to be involved in the carcinogenesis of the breast and contribute to therapeutic resistance. The programmed death-ligand 1 (PD-L1) expression of BC correlated with a poor prognosis. Immunotherapies that target PD-L1 have great potential and have been successful when applied to cancer treatment. However, whether PD-L1 regulates BCSC formation is unknown.

METHODS

BCSCs were enriched by serum-free suspension culture. The properties of BCSCs were examined by mammosphere formation assay, CD44+/Cd24-, aldehyde dehydrogenase (ALDH) assay, CSC marker analysis, and mammosphere growth assay. To elucidate the functions of bromodomain-containing protein 4 (BRD4), nuclear PD-L1, and RelB proteins in the stemness of BCSCs, mammosphere formation was examined using BRD4 inhibitor and degrader, PD-L1 degrader, and RelB inhibitor. The antitumor function of 3',4',7,8-tetrahydroxyflavone (THF), a specific BRD4 inhibitor, was studied through in vivo tumor model and mouse studies, and the protein levels of c-Myc, PD-L1, and RelB were examined in tumor model under THF treatment.

RESULTS

BRD4 was upregulated in breast CSCs and regulates the stemness of BCs. The downregulation of BRD4 using BRD4 PROTAC, ARV-825, and BRD4 inhibitor, (+)-JQ1, inhibits mammosphere formation and reduces the levels of breast CSC markers (CD44+/CD24- and ALDH1), stem cell marker genes, and mammosphere growth. BRD4 inhibitor (JQ1) and degrader (ARV825) downregulate membrane and nuclear fractions of PD-L1 through the inhibition of PD-L1 transcript levels. The knockdown of PD-L1 inhibits mammosphere formation. Verteporfin, a PD-L1 degrader, inhibits the transcripts and protein levels of PD-L1 and downregulates the transcript and protein levels of RelB. Calcitriol, a RelB inhibitor, and the knockdown of RelB using si-RelB regulate mammosphere formation through interleukin-6 (IL-6) expression. THF is a natural product and a potent selective BRD4 inhibitor, inhibits mammosphere formation, and reduces the levels of CD44+/CD24- and mammosphere growth by downregulating c-Myc, PD-L1, and RelB. 3',4',7,8-THF shows tumoricidal activity and increased levels of CD3+CD4+ and CD3+CD8+ T-cells in the tumor and tumor-draining lymph nodes (TDLNs) in the murine tumor model using 4T1 and MC38 cells.

CONCLUSIONS

The results show the first evidence of the essential role of the BRD4/nuclear PD-L1/RelB axis in breast CSC formation. The nuclear PD-L1 regulates RelB, and the RelB/p65 complex induces IL6 and breast CSC formation. Targeting nuclear PD-L1 represents a potential and novel tool for immunotherapies of intractable BC. Video Abstract.

Bacillus-supplemented diet improves growth performance in Jeju native pigs by modulating myogenesis and adipogenesis

Probiotics are used in pigs as nutritional supplements to improve health and induce the development of muscle and adipose tissue for enhancing growth performance and harvesting quality meat. In this study, we investigated the effects of Bacillus-based probiotic supplementation on the physiological and biochemical changes in Jeju native pigs (JNPs), including growth performance, backfat layers, blood parameters, serum IgG levels, myogenic and adipogenic markers, and expression of inflammatory markers. Average daily gain and feed efficiency were higher in the Bacillus diet group than in the basal diet group, while backfat thickness was lower in the Bacillus diet group than in the basal diet group. Blood biochemical parameters and hematological profiles were not altered significantly by Bacillus-based probiotic supplementation. Serum IgG concentration increased in the Bacillus diet group compared to the basal diet group. The Bacillus diet group showed increased adipogenic and myogenic markers expression in the longissimus dorsi muscle and adipose tissues. Overall, the data suggest that the Bacillus-based probiotics-supplemented diet regulates myogenesis and adipogenesis in JNPs and improves growth performance. We postulate that this may be due to the changes in the gut microbiota of pigs due to probiotic supplementation.

Association between Gut Microbial Change and Acute Gastrointestinal Toxicity in Patients with Prostate Cancer Receiving Definitive Radiation Therapy: A Prospective Pilot Analysis

PURPOSE/OBJECTIVE(S)

The gut microbiome is an emerging biomarker that is known to have a pivotal role in the development of diverse human diseases. This prospective cohort study aimed to investigate the association between gut microbial changes and acute gastrointestinal (GI) toxicities in prostate cancer patients receiving definitive radiation therapy (RT).

MATERIALS/METHODS

Seventy-nine fecal samples from 16 prostate cancer patients were analyzed. Stool samples were collected at the following timepoints: pre-RT (prRT), 2 weeks after the start of RT (RT-2w), 5 weeks after the start of RT (RT-5w), 1 month after completion of RT (poRT-1m), and 3 months after completion of RT (poRT-3m). Total RT doses were 69.6‒74.4 Gy at 2.4 Gy per fraction in the high-dose area and 45‒50.4 Gy at 1.8 Gy per fraction in the low-dose area. Alpha- and beta-diversity were estimated. We computed the microbial community polarization index (MCPI) as an indicator of RT-induced dysbiosis. A linear mixed effect model was adopted to evaluate time effects after RT. Metabolic pathway abundances were inferred using bioinformatics tools.

RESULTS

Seven patients experienced ≥ grade 1 acute GI toxicities. Patients experiencing toxicity had lower alpha diversity, especially at RT-2w (P = 0.037) and RT-5w (P = 0.003), with the microbiota enriched in Fusobacteria, Fusobacterium, and Bacteroides fragilis. Patients receiving a large RT field had a trend of lower alpha diversity, particularly at poRT-1m (P = 0.027), with the microbiota enriched in Propionibacteriaceae, Cutibacterium, and Prevotella stercorea. Compared with the MCPI at prRT, the MCPI observed at poRT-1m in patients experiencing toxicities was significantly elevated (P = 0.007). In terms of predicted metabolic pathways, we found linearly decreasing pathways, including carbon fixation pathways in prokaryotes (P = 0.035) and the bacterial secretion system (P = 0.005), in patients who experienced toxicities. Regarding the RT field, no linear trend of functional pathways was found across timepoints.

CONCLUSION

We showed RT-induced dysbiosis in the gut microbiome among patients with prostate cancer who experienced toxicities or received a large RT field. Reduced diversity and elevated RT-related MCPI could be helpful for developing individualized RT approaches. Longitudinal analysis revealed dynamic changes in several microbes and metabolic pathways, which should be validated in a whole metagenome sequencing study.

Two-dimensional material-based complementary ambipolar field-effect transistors with ohmic-like contacts

Ambipolar field-effect transistors (FETs) possessing both electron and hole carriers enable implementation of novel reconfigurable transistors, artificial synaptic transistors, and output polarity controllable (OPC) amplifiers. Here, we fabricated a two-dimensional (2D) material-based complementary ambipolar FET and investigated its electrical characteristics. Properties of ohmic-like contacts at source/drain sides were verified from output characteristics and temperature-dependent measurements. The symmetry of electron and hole currents can be easily achieved by optimization of the MoS2 or WSe2 channels, different from the conventional ambipolar FET with fundamental issues related to Schottky barriers. In addition, we demonstrated successful operation of a complementary inverter and OPC amplifier, using the fabricated complementary ambipolar FET based on 2D materials.&#xD.

13-Oxo-9Z,11E-octadecadienoic Acid Down-regulates c-Myc and Attenuates Breast Cancer Cell Stemness

BACKGROUND/AIM

Breast cancer stem cells (BCSCs) are involved in the development of breast cancer and contribute to therapeutic resistance. This study aimed to investigate the anticancer stem cell (CSC) mechanism of 13-Oxo-9Z,11E-octadecadienoic acid (13-Oxo-ODE) as a potent CSC inhibitor in breast cancer.

MATERIALS AND METHODS

The effects of 13-Oxo-ODE on BCSCs were evaluated using a mammosphere formation assay, CD44^high/CD24^low analysis, aldehyde dehydrogenase (ALDH) assay, apoptosis assay, quantitative real-time PCR, and western blotting.

RESULTS

We found that 13-Oxo-ODE suppressed cell proliferation, CSC formation, and mammosphere proliferation and increased apoptosis of BCSCs. Additionally, 13-Oxo-ODE reduced the subpopulation of CD44^high/CD24^low cells and ALDH expression. Furthermore, 13-Oxo-ODE decreased c-myc gene expression. These results suggest that 13-Oxo-ODE has potential as a natural inhibitor targeting BCSCs through the degradation of c-Myc.

CONCLUSION

In summary, 13-Oxo-ODE induced CSC death possibly through reduced c-Myc expression, making it a promising natural inhibitor of BCSCs.

Isophysalin A Inhibits the Stemness of Breast Cancer Cells Possibly via Stat3 and IL-6 Signaling

BACKGROUND/AIM

Breast cancer stem cells (BCSCs) are involved in carcinogenesis of the breast and contribute to therapeutic resistance. In the present study, we found that isophysalin A acts as a potent cancer stem cell inhibitor and investigated the anti-CSC mechanism of action of isophysalin A on breast cancer.

MATERIALS AND METHODS

The effect of isophysalin A on BCSCs was examined using a mammosphere formation, a colony formation and a cell migration assay, as well as CD44 (Cluster of differentiation 44)high/CD24 (Cluster of differentiation 24)low analysis, an apoptosis assay, quantitative real-time PCR, western blotting, an electrophoretic mobility shift assay, and a cytokine profiling assay.

RESULTS

Isophysalin A inhibited cell proliferation, colony formation, cell migration, CSC formation, and mammosphere proliferation and increased BCSC apoptosis. The subpopulation of CD44high/CD24low was decreased by isophysalin A, which also reduced the DNA binding of Stat3 and the total and nuclear protein expression levels of Stat3 and phosphorylated Stat3. Furthermore, the mRNA and media IL-6/IL-8 levels of the mammosphere were also reduced by isophysalin A.

CONCLUSION

Isophysalin A inhibited the Stat3 and IL-6 signaling pathways and induced CSC death; thus, isophysalin A may be a potential natural inhibitor of BCSCs.

Oropharyngeal, proximal colonic, and vaginal microbiomes of healthy Korean native black pig gilts

BACKGROUND

Exploring the microbiome in multiple body sites of a livestock species informs approaches to promote its health and performance through efficient and sustainable modulation of these microbial ecosystems. Here, we employed 16S rRNA gene sequencing to describe the microbiome in the oropharyngeal cavity, proximal colon, and vaginal tract of Jeju Black pigs (JBP), which are native to the Korean peninsula.

RESULTS

We sampled nine 7-month-old JBP gilts raised under controlled conditions. The most abundant phyla that we found within the oropharyngeal microbiota were Proteobacteria, Bacteroidetes, Fusobacteria and Firmicutes, collectively providing core features from twenty-five of their genera. We also found a proximal colonic microbial core composed of features from twenty of the genera of the two predominant phyla, Firmicutes, and Bacteroidetes. Remarkably, within the JBP vaginal microbiota, Bacteroidetes dominated at phylum level, contrary to previous reports regarding other pig breeds. Features of the JBP core vaginal microbiota, came from seventeen genera of the major phyla Bacteroidetes, Firmicutes, Proteobacteria, and Fusobacteria. Although these communities were distinct, we found some commonalities amongst them. Features from the genera Streptococcus, Prevotella, Bacillus and an unclassified genus of the family Ruminococcaceae were ubiquitous across the three body sites. Comparing oropharyngeal and proximal colonic communities, we found additional shared features from the genus Anaerorhabdus. Between oropharyngeal and vaginal ecosystems, we found other shared features from the genus Campylobacter, as well as unclassified genera from the families Fusobacteriaceae and Flavobacteriaceae. Proximal colonic and vaginal microbiota also shared features from the genera Clostridium, Lactobacillus, and an unclassified genus of Clostridiales.

CONCLUSIONS

Our results delineate unique and ubiquitous features within and across the oropharyngeal, proximal colonic and vaginal microbial communities in this Korean native breed of pigs. These findings provide a reference for future microbiome-focused studies and suggest a potential for modulating these communities, utilizing ubiquitous features, to enhance health and performance of the JBP.

Repeated Administration of Cisplatin Transforms Kidney Fibroblasts through G2/M Arrest and Cellular Senescence

Cisplatin is a potent chemotherapeutic used for the treatment of many types of cancer, but it has nephrotoxic side effects leading to acute kidney injury and subsequently chronic kidney disease (CKD). Previous work has focused on acute kidney tubular injury induced by cisplatin, whereas the chronic sequelae post-injury has not been well-explored. In the present study, we established a kidney fibroblast model of CKD induced by repeated administration of cisplatin (RAC) as a clinically relevant model. In NRK-49F rat kidney fibroblasts, RAC upregulated α-smooth muscle actin (α-SMA) and fibronectin proteins, suggesting that RAC induces kidney fibroblast-to-myofibroblast transformation. RAC also enhanced cell size, including the cell attachment surface area, nuclear area, and cell volume. Furthermore, RAC induced p21 expression and senescence-associated β-galactosidase activity, suggesting that kidney fibroblasts exposed to RAC develop a senescent phenotype. Inhibition of p21 reduced cellular senescence, hypertrophy, and myofibroblast transformation induced by RAC. Intriguingly, after RAC, kidney fibroblasts were arrested at the G2/M phase. Repeated treatment with paclitaxel as an inducer of G2/M arrest upregulated p21, α-SMA, and fibronectin in the kidney fibroblasts. Taken together, these data suggest that RAC transforms kidney fibroblasts into myofibroblasts through G2/M arrest and cellular senescence.

High-quality metagenome-assembled genomes from proximal colonic microbiomes of synbiotic-treated korean native black pigs reveal changes in functional capacity

Synbiotics are feed supplements with the potential to promote health and productivity in pigs partly, through modulation of the intestinal microbiome. Our study used shotgun sequencing and 16S rRNA gene sequencing techniques to characterize the effect of a synbiotic containing three Lactobacillus species and a fructo-oligosaccharide on the proximal colonic microbiome of 4- to 7-month-old Korean native black gilts. With shotgun sequencing we constructed unique metagenome-assembled genomes of gut microbiota in Native Black Pig for the first time, which we then used for downstream analysis. Results showed that synbiotic treatment did not alter microbial diversity and evenness within the proximal colons, but altered composition of some members of the Lactobacillaceae, Enterococcaceae and Streptococcaceae families. Functional analysis of the shotgun sequence data revealed 8 clusters of orthologous groups (COGs) that were differentially represented in the proximal colonic microbiomes of synbiotic-treated Jeju black pigs relative to controls. In conclusion, our results show that administering this synbiotic causes changes in the functional capacity of the proximal colonic microbiome of the Korean native black pig. This study improves our understanding of the potential impact of synbiotics on the colonic microbiome of Korean native black pigs.

Primaquine Inhibits the Endosomal Trafficking and Nuclear Localization of EGFR and Induces the Apoptosis of Breast Cancer Cells by Nuclear EGFR/Stat3-Mediated c-Myc Downregulation

Triple-negative breast cancer (TNBC) cells overexpress the epidermal growth factor receptor (EGFR). Nuclear EGFR (nEGFR) drives resistance to anti-EGFR therapy and is correlated with poor survival in breast cancer. Inhibition of EGFR nuclear translocation may be a reasonable approach for the treatment of TNBC. The anti-malarial drugs chloroquine and primaquine have been shown to promote an anticancer effect. The aim of the present study was to investigate the effect and mechanism of chloroquine- and primaquine-induced apoptosis of breast cancer cells. We showed that primaquine, a malaria drug, inhibits the growth, migration, and colony formation of breast cancer cells in vitro, and inhibits tumor growth in vivo. Primaquine induces damage to early endosomes and inhibits the nuclear translocation of EGFR. Primaquine inhibits the interaction of Stat3 and nEGFR and reduces the transcript and protein levels of c-Myc. Moreover, primaquine and chloroquine induce the apoptosis of breast cancer cells through c-Myc/Bcl-2 downregulation, induce early endosome damage and reduce nEGFR levels, and induce apoptosis in breast cancer through nEGFR/Stat3-dependent c-Myc downregulation. Our study of primaquine and chloroquine provides a rationale for targeting EGFR signaling components in the treatment of breast cancer.

5-Hydroxymaltol Derived from Beetroot Juice through Lactobacillus Fermentation Suppresses Inflammatory Effect and Oxidant Stress via Regulating NF-kB, MAPKs Pathway and NRF2/HO-1 Expression

Inflammation is the first response of the immune system against bacterial pathogens. This study isolated and examined an antioxidant derived from Lactobacillus fermentation products using cultured media with 1% beet powder. The antioxidant activity of the beet culture media was significantly high. Antioxidant activity-guided purification and repeated sample isolation yielded an isolated compound, which was identified as 5-hydoxymaltol using nuclear magnetic resonance spectrometry. We examined the mechanism of its protective effect on lipopolysaccharide (LPS)-induced inflammation of macrophages. 5-Hydroxymaltol suppressed nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. It also suppressed tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS) in the messenger RNA and protein levels in LPS-treated RAW 264.7 cells. Moreover, it suppressed LPS-induced nuclear translocation of NF-κB (p65) and mitogen-activated protein kinase activation. Furthermore, 5-hydroxymaltol reduced LPS-induced reactive oxygen species (ROS) production as well as increased nuclear factor erythroid 2-related factor 2 and heme oxygenase 1 expression. Overall, this study found that 5-hydroxymaltol has anti-inflammatory activities in LPS-stimulated RAW 264.7 macrophage cells based on its inhibition of pro-inflammatory cytokine production depending on the nuclear factor κB signaling pathway, inhibition of LPS-induced reactive oxygen species production, inhibition of LPS-induced mitogen-activated protein kinase induction, and induction of the nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling pathway. Our data showed that 5-hydroxymaltol may be an effective compound for treating inflammation-mediated diseases.

Physalin A, 13,14-Seco-16, 24-Cyclo-Steroid, Inhibits Stemness of Breast Cancer Cells by Regulation of Hedgehog Signaling Pathway and Yes-Associated Protein 1 (YAP1)

The Hedgehog (HH) signaling pathway plays an important role in embryonic development and adult organ homeostasis. Aberrant activity of the Hedgehog signaling pathway induces many developmental disorders and cancers. Recent studies have investigated the relationship of this pathway with various cancers. GPCR-like protein Smoothened (SMO) and the glioma-associated oncogene (GLI1) are the main effectors of Hedgehog signaling. Physalin A, a bioactive substance derived from Physalis alkekengi, inhibits proliferation and migration of breast cancer cells and mammospheres formation. Physalin A-induced apoptosis and growth inhibition of mammospheres, and reduced transcripts of cancer stem cell (CSC) marker genes. Physalin A reduced protein expressions of SMO and GLI1/2. Down-regulation of SMO and GLI1 using siRNA inhibited mammosphere formation. Physalin A reduced mammosphere formation by reducing GLI1 gene expression. Down-regulation of GLI1 reduced CSC marker genes. Physalin A reduced protein level of YAP1. Down-regulation of YAP1 using siRNA inhibited mammosphere formation. Physalin A reduced mammosphere formation through reduction of YAP1 gene expression. Down-regulation of YAP1 reduced CSC marker genes. We showed that treatment of MDA-MB-231 breast cancer cells with GLI1 siRNA induced inhibition of mammosphere formation and down-regulation of YAP1, a Hippo pathway effector. These results show that Hippo signaling is regulated by the Hedgehog signaling pathway. Physalin A also inhibits the canonical Hedgehog and Hippo signaling pathways, CSC-specific genes, and the formation of mammospheres. These findings suggest that physalin A is a potential therapeutic agent for targeting CSCs.

5-Desmethylsinensetin isolated from Artemisia princeps suppresses the stemness of breast cancer cells via Stat3/IL-6 and Stat3/YAP1 signaling

AIMS

To study 5-desmethylsinensetin exhibiting potential anticancer activity against breast cancer stem cells and the related molecular mechanism.

MAIN METHODS

In this study, isolation of a cancer stem cell (CSC) inhibitor of Artemisia princeps was performed using a silica gel column, a Sephadex gel column, and high-performance liquid chromatography. A single compound was purified via activity-based isolation using mammosphere formation assays. An MTS was used to examine the proliferation of breast cancer cells, and flow cytometry was used to analyze apoptosis and cancer stem cell markers. Western blotting was used to detect the signaling pathway.

RESULTS

The isolated compound was identified as 5-desmethylsinensetin using nuclear magnetic resonance and mass spectrometry. 5-Desmethylsinensetin suppresses the proliferation and mammosphere formation of breast cancer cells, reduces the subpopulations of CD44⁺/CD24^- and ALDH1⁺ cancer cells, and reduces the transcription of the stemness markers Oct4, c-Myc, Nanog and CD44 in Breast CSCs. 5-Desmethylsinensetin inhibits the total and nuclear expression of Stat3 and p-Stat3, as well as the translocation of YAP1. Additionally, 5-desmethylsinensetin reduces the mRNA and protein levels of IL-6.

CONCLUSION

Our results show that 5-desmethylsinensetin exhibits potential anticancer activity against breast cancer stem cells via Stat3-IL-6 and Stat3-YAP1 signaling.

Wogonin Influences Osteosarcoma Stem Cell Stemness Through ROS-dependent Signaling

Backgorund/Aim: Wogonin, a flavonoid-like compound extracted from the root of Scutellaria baicalensis Georgi, has been shown to have anticancer effects against cancer cells. Osteosarcoma is the most malignant type of bone cancer and can appear in any bone, with a high propensity for relapse and metastasis. The present study aimed to assess the anticancer effects of wogonin on osteosarcoma stem cells.

MATERIALS AND METHODS

The cytotoxic effects of wogonin on CD133⁺ Cal72 osteosarcoma stem cells were assessed through in vitro experiments by MTT assay, transwell assay, sphere-formation assay, flow cytometry, immunocytochemistry and western blotting.

RESULTS

Wogonin suppressed stem cell characteristics and the expression of stem cell-related genes by regulating reactive oxygen species (ROS) levels and ROS-related signaling of CD133⁺ Cal72 cells, effects which were reversed by ROS scavenger N-acetylcysteine.

CONCLUSION

Wogonin may be a promising candidate for successful clinical management of osteosarcoma by regulating ROS-related mechanisms and stem cell-related genes.

The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018

Global aviation operations contribute to anthropogenic climate change via a complex set of processes that lead to a net surface warming. Of importance are aviation emissions of carbon dioxide (CO₂), nitrogen oxides (NO_x), water vapor, soot and sulfate aerosols, and increased cloudiness due to contrail formation. Aviation grew strongly over the past decades (1960-2018) in terms of activity, with revenue passenger kilometers increasing from 109 to 8269 billion km yr^-1, and in terms of climate change impacts, with CO₂ emissions increasing by a factor of 6.8 to 1034 Tg CO₂ yr^-1. Over the period 2013-2018, the growth rates in both terms show a marked increase. Here, we present a new comprehensive and quantitative approach for evaluating aviation climate forcing terms. Both radiative forcing (RF) and effective radiative forcing (ERF) terms and their sums are calculated for the years 2000-2018. Contrail cirrus, consisting of linear contrails and the cirrus cloudiness arising from them, yields the largest positive net (warming) ERF term followed by CO₂ and NO_x emissions. The formation and emission of sulfate aerosol yields a negative (cooling) term. The mean contrail cirrus ERF/RF ratio of 0.42 indicates that contrail cirrus is less effective in surface warming than other terms. For 2018 the net aviation ERF is +100.9 milliwatts (mW) m^-2 (5-95% likelihood range of (55, 145)) with major contributions from contrail cirrus (57.4 mW m^-2), CO₂ (34.3 mW m^-2), and NO_x (17.5 mW m^-2). Non-CO₂ terms sum to yield a net positive (warming) ERF that accounts for more than half (66%) of the aviation net ERF in 2018. Using normalization to aviation fuel use, the contribution of global aviation in 2011 was calculated to be 3.5 (4.0, 3.4) % of the net anthropogenic ERF of 2290 (1130, 3330) mW m^-2. Uncertainty distributions (5%, 95%) show that non-CO₂ forcing terms contribute about 8 times more than CO₂ to the uncertainty in the aviation net ERF in 2018. The best estimates of the ERFs from aviation aerosol-cloud interactions for soot and sulfate remain undetermined. CO₂-warming-equivalent emissions based on global warming potentials (GWP* method) indicate that aviation emissions are currently warming the climate at approximately three times the rate of that associated with aviation CO₂ emissions alone. CO₂ and NO_x aviation emissions and cloud effects remain a continued focus of anthropogenic climate change research and policy discussions.

The Antiasthma Medication Ciclesonide Suppresses Breast Cancer Stem Cells through Inhibition of the Glucocorticoid Receptor Signaling-Dependent YAP Pathway

Ciclesonide is an FDA-approved glucocorticoid used to treat asthma and allergic rhinitis. However, whether it has anticancer and anti-cancer stem cell (CSC) effects is unknown. This study focused on investigating the effect of ciclesonide on breast cancer and CSCs and determining its underlying mechanism. Here, we showed that ciclesonide inhibits breast cancer and CSC formation. Similar glucocorticoids-dexamethasone and prednisone-did not inhibit CSC formation. Ciclesonide-induced glucocorticoid receptor (GR) degradation was dependent on ubiquitination. We showed via GR small interfering RNA (siRNA) that GR plays an important role in CSC formation. We showed via western blot and immunofluorescence assays that ciclesonide reduces the nuclear level of GR. The GR antagonist RU-486 also inhibited CSC formation. Ciclesonide reduced the protein level of the Hippo transducer Yes-associated protein (YAP). GR siRNA induced a decrease in YAP protein expression and inhibited mammosphere formation. The YAP inhibitor verteporfin inhibited CSC formation and transcription of the connective tissue growth factor and cysteine-rich protein 61 genes. The GR/YAP1 pathway regulated breast CSC formation. We showed that the GR/YAP signaling pathway regulates breast CSC formation and revealed a new approach for targeting GR and YAP to inhibit CSC formation.

Plant Volatile, Phenylacetaldehyde Targets Breast Cancer Stem Cell by Induction of ROS and Regulation of Stat3 Signal

Cancer stem cells (CSCs) are undifferentiated cells that give rise to tumor and resistance to chemotherapy. This study reports that phenylacetaldehyde (PAA), a flower flavor, inhibits formation on breast CSCs. PAA showed anti-proliferation and increased apoptosis of breast cancer. PAA also reduced tumor growth in an in vivo mice model. PAA reduced the CD44⁺/CD24⁻ and ALDH1-expressing cells, mammosphere formation, and CSC marker genes. PAA preferentially induced reactive oxygen species (ROS) production and combined treatment with PAA and N-acetyl cysteine (NAC) decreased inhibition of mammosphere formation. PAA reduced phosphorylation of nuclear Stat3. PAA inhibited Stat3 signaling through de-phosphorylation of Stat3 and reduced secretory IL-6. Our results suggest that the PAA-induced ROS deregulated Stat3/IL-6 pathway and PAA may be a potential agent targeting breast cancer and CSCs.

Non-thermal Plasma-activated Medium Induces Apoptosis of Aspc1 Cells Through the ROS-dependent Autophagy Pathway

BACKGROUND/AIM

Numerous studies on various cancer cell lines have reported that direct exposure to non-thermal plasma treatment using plasma-activated medium (PAM) can be applied as a novel technology for cancer therapy. In this study, we investigated the inhibitory effects of PAM on Aspc1 pancreatic cancer cells and the mechanisms responsible for the cell death observed.

MATERIALS AND METHODS

A colony-formation, sphere-formation, wound-healing and transwell assays, immunocytochemistry and western blot analysis were used monitor effects of PAM.

RESULTS

PAM induced a greater cytotoxic effect in pancreatic cancer cells compared to that induced in NIH3T3 cells and 293T cells, and significantly inhibited colony and sphere formation, and cell migration of Aspc1 cells. Furthermore, PAM treatment increased the accumulation of reactive oxygen species (ROS) and reduced the mitochondrial membrane potential in Aspc1 cells. In addition, PAM treatment down-regulated the AKT serine/threonine kinase 1/signal transducer and activator of transcription 3 signaling pathway and induced ROS-dependent cellular autophagy.

CONCLUSION

Our findings suggest that PAM can induce apoptosis of Aspc1 cells through ROS-dependent autophagy and may be a candidate for use in pancreatic cancer therapeutics.

Machilin D, a Lignin Derived from Saururus chinensis, Suppresses Breast Cancer Stem Cells and Inhibits NF-κB Signaling

Cancer stem cells are responsible for breast cancer initiation, metastasis, and relapse. Targeting breast cancer stem cells (BCSCs) using phytochemicals is a good strategy for the treatment of cancer. A silica gel, a reversed-phase C18 column (ODS), a Sephadex LH-20 gel, thin layer chromatography, and high-performance liquid chromatography (HPLC) were used for compound isolation from Saururus chinensis extracts. The isolated compound was identified as machilin D by mass spectrometry and nuclear magnetic resonance (NMR). Machilin D inhibited the growth and mammosphere formation of breast cancer cells and inhibited tumor growth in a xenograft mouse model. Machilin D reduced the proportions of CD44⁺/CD24^- and aldehyde dehydrogenase 1 (ALDH1)-positive cells. Furthermore, this compound reduced the nuclear localization of the NF-κB protein and decreased the IL-6 and IL-8 secretion in mammospheres. These results suggest that machilin D blocks IL-6 and IL-8 signaling and induces CSC death and thus may be a potential agent targeting BCSCs.

The FDA-Approved Anti-Asthma Medicine Ciclesonide Inhibits Lung Cancer Stem Cells through Hedgehog Signaling-Mediated SOX2 Regulation

Ciclesonide is an FDA-approved glucocorticoid (GC) used to treat asthma and allergic rhinitis. However, its effects on cancer and cancer stem cells (CSCs) are unknown. Our study focuses on investigating the inhibitory effect of ciclesonide on lung cancer and CSCs and its underlying mechanism. In this study, we showed that ciclesonide inhibits the proliferation of lung cancer cells and the growth of CSCs. Similar glucocorticoids, such as dexamethasone and prednisone, do not inhibit CSC formation. We show that ciclesonide is important for CSC formation through the Hedgehog signaling pathway. Ciclesonide reduces the protein levels of GL1, GL2, and Smoothened (SMO), and a small interfering RNA (siRNA) targeting SMO inhibits tumorsphere formation. Additionally, ciclesonide reduces the transcript and protein levels of SOX2, and an siRNA targeting SOX2 inhibits tumorsphere formation. To regulate breast CSC formation, ciclesonide regulates GL1, GL2, SMO, and SOX2. Our results unveil a novel mechanism involving Hedgehog signaling and SOX2 regulated by ciclesonide in lung CSCs, and also open up the possibility of targeting Hedgehog signaling and SOX2 to prevent lung CSC formation.