TCF12-regulated GRB7 facilitates the HER2+ breast cancer progression by activating Notch1 signaling pathway.

BACKGROUND: Human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC), which accounts for approximately one-fifth of all BCs, are highly invasive with a high rate of recurrence and a poor prognosis. Several studies have shown that growth factor receptor-bound protein 7 (GRB7) might be a potential therapeutic target for tumor diagnosis and prognosis. Nevertheless, the role of GRB7 in HER2+ BC and its underlying mechanisms have not been fully elucidated. The aim of this study was to investigate the biological function and regulatory mechanism of GRB7 in HER2+ BC. METHODS: Bioinformatics analysis was performed using the TCGA, GEO and CancerSEA databases to evaluate the clinical significance of GRB7. RT quantitative PCR, western blot and immunofluorescence were conducted to assess the expression of GRB7 in BC cell lines and tissues. MTT, EdU, colony formation, wound healing, transwell, and xenograft assays were adopted to explore the biological function of GRB7 in HER2+ BC. RNA sequencing was performed to analyze the signaling pathways associated with GRB7 in SK-BR-3 cells after the cells were transfected with GRB7 siRNA. Chromatin immunoprecipitation analysis (ChIP) and luciferase reporter assay were employed to elucidate the potential molecular regulatory mechanisms of GRB7 in HER2+ BC. RESULTS: GRB7 was markedly upregulated and associated with poor prognosis in BC, especially in HER2+ BC. Overexpression of GRB7 increased the proliferation, migration, invasion, and colony formation of HER2+ BC cells, while depletion of GRB7 had the opposite effects in HER2+ BC cells and inhibited xenograft growth. ChIP-PCR and luciferase reporter assay revealed that TCF12 directly bound to the promoter of the GRB7 gene to promote its transcription. GRB7 facilitated HER2+ BC epithelial-mesenchymal transition (EMT) progression by interacting with Notch1 to activate Wnt/ß-catenin pathways and other signaling (i.e., AKT, ERK). Moreover, forced GRB7 overexpression activated Wnt/ß-catenin to promote EMT progression, and partially rescued the inhibition of HER2+ BC proliferation, migration and invasion induced by TCF12 silencing. CONCLUSIONS: Our work elucidates the oncogenic role of GRB7 in HER2+ BC, which could serve as a prognostic indicator and promising therapeutic target.

Nomograms for predicting overall survival in colorectal cancer patients with metastasis to the liver, lung, bone, and brain.

BACKGROUND: The aim of this study was to identify the heterogeneous and homogeneous prognostic factors associated with distant metastasis to the liver, lung, bone, and brain in colorectal cancer (CRC) patients and then construct nomograms to predict the prognosis. METHODS: CRC patients registered in the surveillance, epidemiology, and end results database between 2010 and 2017 were included. A Cox regression model was used to analyse homogeneous and heterogeneous prognostic factors, and Kaplan‒Meier analysis was performed to estimate overall survival (OS). Predictive nomograms were constructed, and their performance was evaluated with C-indexes, calibration curves and the area under the receiver operating characteristic (ROC) curve (AUC). RESULTS: A total of 37,641 patients with distant metastasis to the liver, lung, bone, and brain were included. The median survival times of patients with liver metastasis, lung metastasis, bone metastasis, and brain metastasis were 12.00 months (95% CI 11.73-12.27 months), 10.00 months (95% CI 9.60-10.41 months), 5.00 months (95% CI 4.52-5.48 months), and 3.00 months (95% CI 2.28-3.72 months), respectively. An older age, higher N stage, elevated carcinoembryonic antigen level, no surgery at the primary site and no/unknown treatment with chemotherapy were identified as homogeneous prognostic factors for the four types of metastases. The calibration curves, C-indexes and AUCs exhibited good performance for predicting the OS of patients with distant metastases to the liver, lung, bone, and brain. CONCLUSIONS: CRC patients with distant metastasis to the liver, lung, bone, and brain exhibited homogeneous and heterogeneous prognostic factors, all of which were associated with shorter survival. The nomograms showed good accuracy and may be used as tools for clinicians to predict the prognosis of CRC patients with distant metastasis.

Achieving Ultra-Wideband NIR-II Emission in Cr3+-Doped Li(Sc,In)(Si,Ge)O4 Phosphors Based on Host Composition Engineering.

Realizing ultra-wideband and tunable near-infrared (NIR) emission remains a great challenge in NIR phosphor development. The luminescence of most reported NIR phosphors exhibits a peak wavelength shorter than 1000 nm and the corresponding FWHM is <200 nm. Here, a series of Cr3+-activated Li(Sc,In)(Si,Ge)O4 phosphors with ultra-wideband and tunable NIR-II emission are successfully developed based on the host composition engineering strategy. Significant spectral engineering in the NIR-II region is achieved with a peak wavelength changing from 1110 to 1253 nm. The olivine host structure could provide Cr3+ activator a highly distorted octahedral site with very weak crystal field strength, which results in NIR-II ultra-wideband emission with FWHM > 300 nm. A detailed discussion on the relationship between structural variation, crystal field splitting, and NIR luminescence has been applied. As far as we know, it is the first report about Cr3+ NIR luminescence engineering in such a long wavelength and wide range. The application of these NIR-II phosphors is demonstrated in intensity-based luminescent thermometry with a relative sensitivity of >2.0% K-1 in the physiological temperature range.

Circular RNAs in the chemoresistance of triple-negative breast cancer: A systematic review.

This study aims to assess studies on circular RNAs (circRNAs) in the chemoresistance of triple-negative breast cancer (TNBC) and provide relevant references for the development of new TNBC chemotherapy sensitivity biomarkers and therapeutic targets. The PubMed, Embase, Web of Knowledge, Cochrane Library, and four Chinese databases were searched up to January 27, 2023, and studies related to TNBC chemoresistance were included. The basic characteristics of the studies and the mechanisms of circRNAs in regulating TNBC chemoresistance were analyzed. A total of 28 studies published between 2018 and 2023 were included, and the chemotherapeutics included adriamycin, paclitaxel, docetaxel, 5-fluorouracil, lapatinib, and so forth. A total of 30 circRNAs were identified, 86.67% (n = 26) of these circRNAs were reported to act as microRNA (miRNA) sponges to regulate chemotherapy sensitivity, while only two circRNAs (circRNA-MTO1 and circRNA-CREIT) interacted with proteins. A total of 14, 12, and 2 circRNAs were reported to be associated with chemoresistance to adriamycin, taxanes, and 5-fluorouracil, respectively. Six circRNAs were found to act as miRNA sponges that promote chemotherapy resistance by regulating the PI3K/Akt signalling pathway. CircRNAs participate in the regulation of TNBC chemoresistance and can be used as biomarkers and therapeutic targets for improving chemotherapy sensitivity. However, further studies are needed to confirm the role of circRNAs in TNBC chemoresistance.

Structural Confinement and Energetic Matching Synergistic Effect toward a High-Energy Transfer Efficiency and a Significant Red Emission Enhancement in a Eu2+,Ln3+ Co-doped Sr9LiMn(PO4)7 Whitlockite Phosphor.

Despite an encouraging progress, Mn2+-activated red phosphors suffer from an insufficient emission intensity and a bad color purity. Thus, it is necessary to find a new strategy to realize a bright red emission through highly efficient Mn2+ sensitization. Herein, manipulating Eu2+-sensitized Sr9LiMn(PO4)7 (SLMP) composition by Ln3+ heterovalent substitution is proved to be able to substantially gain a tremendous Mn2+ emission enhancement and result in a dominant red Mn2+ emission. It is found that the emission enhancement ratio is proportional to the order of lanthanide contraction. Notably, Tb3+ doping realizes a 427-fold rise in the integrated emission intensity compared with the SLMP host, which is close to the theoretical maximum of 500. An underlying mechanism for Mn2+ red emission enhancement is proposed, which is attributed to a high-energy transfer probability from Eu2+ to Mn2+ via Ln3+-induced further structural confinement plus an energetic match effect. Meanwhile, homovalent (Ca2+) substitution could precisely tailor Mn2+ emitting color from orange-red to deep red. A warm-white LED device with a low color temperature of 3394 K, a high color-rendering index of 90.2, and suitable CIE coordinates of (0.403, 0.373) is fabricated using optimized phosphor SLMP:Eu2+, Tb3+. These results might reveal a new strategy to develop new red-emitting phosphors with a bright and highly purified red Mn2+ emission.

Homogeneous and heterogeneous risk and prognostic factors for lung metastasis in colorectal cancer patients.

BACKGROUND: The lung is one of the most frequent distant metastasis sites in colorectal cancer (CRC) patients; however, lung metastasis risk and prognostic factors have not been comprehensively elucidated. This study aimed to identify the homogeneous and heterogeneous lung metastasis risk and prognostic factors in CRC patients using the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: CRC patients registered in the SEER database between 2010 and 2016 were included to analyse risk factors for developing lung metastasis by using univariable and multivariable logistic regression. Patients diagnosed between 2010 and 2015 were selected to investigate prognostic factors for lung metastasis by conducting Cox regression. Kaplan-Meier analysis was used to estimate overall survival outcomes. RESULTS: A total of 10,598 (5.2%) patients with synchronous lung metastasis were diagnosed among 203,138 patients with CRC. The median survival time of patients with lung metastasis was 10.0 months (95% CI 9.6-10.5 months). Older age, unmarried status, uninsured status, poor histological differentiation, more lymphatic metastasis, CEA positivity, liver metastasis, bone metastasis and brain metastasis were lung metastasis risk and prognostic factors. Black patients and those with left colon, rectum, and stage T4 disease were more likely to develop lung metastasis, while patients with right colon cancer and no surgical treatment of the primary tumour had poor survival outcomes. CONCLUSION: The incidence of lung metastasis in CRC patients was 5.2%. CRC patients with lung metastasis exhibited homogeneous and heterogeneous risk and prognostic factors. These results are helpful for clinical evaluation and individual treatment decision making.

The catalytic effect of RuM-C catalyst attached to carbon- based support for hydrogen evolution reaction.

The potential of converting traditional biomass into low-cost HER catalysts has broad application prospects. In this paper, fungus is used as a carbon-based carrier. The bimetallic catalyst RuM-C (M = V, Mo, W, Zn, Cu) was synthesized under inert gas protection at high temperature. The order of electrocatalytic activity is RuV-C > RuZn-C > RuW-C > RuMo-C > Ru-C > RuCu-C > BF-C, which indicates that RuV-C exhibits excellent HER activity. Due to its irregular sheet structure, the specific surface area of the catalyst is increased. Impressively, it exhibits extremely high catalytic activity for HER in 1 M KOH due to favorable kinetics and excellent specific activity. Consequently, the prepared RuV-C exhibited excellent and stable HER activity compared Ru-C with a low overpotential of 65.78 mV at the current densities of 10 mA cm-2and Tafel slope of 45.26 mV dec-1. The potential only decreased by 88 mV after 24 h of continuous testing, which indicates that the catalyst has outstanding stability. This work will provide positive inspiration for the promotion of a new Ru-based biomass HER electrocatalyst.

Ultrahigh-Energy-Transfer Efficiency and Efficient Mn2+ Red Emission Realized by Structural Confinement in Ca9LiMn(PO4)7:Eu2+,Tb3+ Phosphor.

Structural confinement on Eu2+-Mn2+ optical centers is an effective strategy to boost Mn2+ red emission. On the basis of the Ca9LiMn(PO4)7 (CLMP) host with a compact Eu2+-Mn2+ distance of ∼3.5 Å, a pure and intense Mn2+ red emission without seeing Eu2+ emission is realized, indicating that an ultrahigh energy transfer (ET) could be induced by a structural confinement effect. It is found that the Mn2+ emission intensity and quantum efficiency could be further improved by a Tb3+ bridging effect, which offers extra energy levels to reduce the energetic mismatch between the excited states of Eu2+ and Mn2+. The optimal sample CLMP:0.02Eu2+,0.90Tb3+ shows a promising performance in terms of high color purity (93.9%), high quantum efficiency (QE = 51.2%), and good thermal stability (70% of the room-temperature value at 373 K). All of the results demonstrate that CLMP:Eu2+,Tb3+ phosphor is a promising red-light-emitting-diode phosphor, and the structural confinement effect should be developed as a general strategy to enhance the ET efficiency for a pure and efficient emission.

Prognostic factors in extensive-stage small cell lung cancer patients with organ-specific metastasis: unveiling commonalities and disparities.

BACKGROUND: This study aimed to identify shared and distinct prognostic factors related to organ-specific metastases (liver, lung, bone, and brain) in extensive-stage small cell lung cancer (ES-SCLC) patients, then construct nomograms for survival prediction. METHODS: Patient data for ES-SCLC were from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2019. Kaplan-Meier analysis was applied to estimate overall survival (OS), and Cox regression was used to identify prognostic factors. A Venn diagram was utilized to distinguish common and unique prognostic factors among the variables assessed. These identified prognostic factors were used to formulate a nomogram, and its predictive accuracy and reliability were evaluated using C-indexes, calibration curves, and receiver operating characteristic (ROC) curves. RESULTS: A total of 24,507 patients diagnosed with ES-SCLC exhibiting metastases to the liver, lung, bone, and brain were included. The 6-month, 1-year, and 2-year OS rates were 46.1%, 19.7%, and 5.0%, respectively. Patients with liver metastasis demonstrated the most unfavorable prognosis, with a 1-year OS rate of 14.5%, while those with brain metastasis had a significantly better prognosis with a 1-year OS rate of 21.6%. The study identified seven common factors associated with a poor prognosis in ES-SCLC patients with organ-specific metastases: older age, male sex, unmarried status, higher T stage, presence of other metastases, and combination radiotherapy and chemotherapy. Furthermore, specific prognostic factors were identified for patients with metastasis to the liver, bone, and brain, including paired tumors, lack of surgical treatment at the primary site, and household income, respectively. To facilitate prognostic predictions, four nomograms were developed and subsequently validated. The performance of these nomograms was assessed using calibration curves, C-indexes, and the area under the curve (AUC), all of which consistently indicated good predictive accuracy and reliability. CONCLUSIONS: Patients diagnosed with ES-SCLC with organ-specific metastases revealed shared and distinct prognostic factors. The nomograms developed from these factors demonstrated good performance and can serve valuable clinical tools to predict the prognosis of ES-SCLC patients with organ-specific metastases.

INPP4B suppresses HER2-induced mesenchymal transition in HER2+ breast cancer and enhances sensitivity to Lapatinib.

Human epidermal growth factor receptor 2 positive (HER2+) breast cancer (BC) tends to metastasize and has a bad prognosis due to its high malignancy and rapid progression. Inositol polyphosphate 4-phosphatase isoenzymes type II (INPP4B) plays unequal roles in the development of various cancers. However, the function of INPP4B in HER2+ BC has not been elucidated. Here we found that INPP4B expression was significantly lower in HER2+ BC and positively correlated with the prognosis by bioinformatics and tissue immunofluorescence analyses. Overexpression of INPP4B inhibited cell proliferation, migration, and growth of xenografts in HER2+ BC cells. Conversely, depletion of INPP4B reversed these effects and activated the PDK1/AKT and Wnt/ß-catenin signaling pathways to promote epithelial-mesenchymal transition (EMT) progression. Moreover, INPP4B overexpression blocked epidermal growth factor (EGF) -induced cell proliferation, migration and EMT progression, whereas INPP4B depletion antagonized HER2 depletion in reduction of cell proliferation and migration of HER2+ BC cells. Additionally, Lapatinib (LAP) inhibited HER2+ BC cell survival, proliferation and migration, and its effect was further enhanced by overexpression of INPP4B. In summary, our results illustrate that INPP4B suppresses HER2+ BC growth, migration and EMT, and its expression level affects patient outcome, further providing new insights into clinical practice.

CCT020312 exerts anti-prostate cancer effect by inducing G1 cell cycle arrest, apoptosis and autophagy through activation of PERK/eIF2α/ATF4/CHOP signaling.

PERK/eIF2α/ATF4/CHOP signaling pathway is one of three major branches of unfolded protein response (UPR) and has been implicated in tumor progression. CCT020312 is a selective PERK activator and may have a potential anti-tumor effect. Here we investigated the anti-prostate cancer effect and its underlying mechanism of CCT020312. Our results showed that CCT020312 inhibited prostate cancer cell viability by inducing cell cycle arrest, apoptosis and autophagy through activation of PERK/eIF2α/ATF4/CHOP signaling. CCT020312 treatment caused cell cycle arrest at G1 phase and increased the levels of cleaved-Caspase3, cleaved-PARP and Bax in prostate cancer C4-2 and LNCaP cells. Moreover, CCT020312 increased LC3II/I, Atg12-Atg5 and Beclin1 levels and induced autophagosome formation. Furthermore, knockdown of CHOP reversed CCT020312-induced cell viability decrease, apoptosis and autophagy. Bafilomycin A1 reversed CCT020312-induced cell viability decrease but had no effect on CCT020312-induced CHOP activation in C4-2 and LNCaP cells. In vivo, CCT020312 suppressed tumor growth in C4-2 cells-derived xenograft mouse model, activated PERK pathway, and induced autophagy and apoptosis. Our study illustrates that CCT020312 exerts an anti-tumor effect in prostate cancer via activating the PERK pathway, thus indicating that CCT020312 may be a potential drug for prostate cancer.

The initiation of oxidative stress and therapeutic strategies in wound healing.

When the production of reactive oxygen species (ROS) is overloaded surpassing the capacity of the reductive rheostat, mammalian cells undergo a series of oxidative damage termed oxidative stress (OS). This phenomenon is ubiquitously detected in many human pathological conditions. Wound healing program implicates continuous neovascularization, cell proliferation, and wound remodeling. Increasing evidence indicates that reactive oxygen species (ROS) have profound impacts on the wound healing process through regulating a series of the physiological and pathological program including inflammatory response, cell proliferation, angiogenesis, granulation as well as extracellular matrix formation. In most pathological wound healing processes, excessive ROS exerts a negative role on the wound healing process. Interestingly, the moderate increase of ROS levels is beneficial in killing bacteria at the wound site, which creates a sterile niche for revascularization. In this review, we discussed the physiological rhythms of wound healing and the role of ROS in this progress, aim to explore the potential manipulation of OS as a promising therapeutic avenue.

CEP55 as a Promising Immune Intervention Marker to Regulate Tumor Progression: A Pan-Cancer Analysis with Experimental Verification.

CEP55, a member of the centrosomal protein family, affects cell mitosis and promotes the progression of several malignancies. However, the relationship between CEP55 expression levels and prognosis, as well as their role in cancer progression and immune infiltration in different cancer types, remains unclear. We used a combined form of several databases to validate the expression of CEP55 in pan-cancer and its association with immune infiltration, and we further screened its targeted inhibitors with CEP55. Our results showed the expression of CEP55 was significantly higher in most tumors than in the corresponding normal tissues, and it correlated with the pathological grade and age of the patients and affected the prognosis. In breast cancer cells, CEP55 knockdown significantly decreased cell survival, proliferation, and migration, while overexpression of CEP55 significantly promoted breast cancer cell proliferation and migration. Moreover, CEP55 expression was positively correlated with immune cell infiltration, immune checkpoints, and immune-related genes in the tumor microenvironment. CD-437 was screened as a potential CEP55-targeted small-molecule compound inhibitor. In conclusion, our study highlights the prognostic value of CEP55 in cancer and further provides a potential target selection for CEP55 as a potential target for intervention in tumor immune infiltration and related immune genes.

Proteomics of serum exosomes identified fibulin-1 as a novel biomarker for mild cognitive impairment.

Mild cognitive impairment (MCI) is a prodrome of Alzheimer's disease pathology. Cognitive impairment patients often have a delayed diagnosis because there are no early symptoms or conventional diagnostic methods. Exosomes play a vital role in cell-to-cell communications and can act as promising biomarkers in diagnosing diseases. This study was designed to identify serum exosomal candidate proteins that may play roles in diagnosing MCI. Mass spectrometry coupled with tandem mass tag approach-based non-targeted proteomics was used to show the differentially expressed proteins in exosomes between MCI patients and healthy controls, and these differential proteins were validated using immunoblot and enzyme-linked immunosorbent assays. Correlation of cognitive performance with the serum exosomal protein level was determined. Nanoparticle tracking analysis suggested that there was a higher serum exosome concentration and smaller exosome diameter in individuals with MCI compared with healthy controls. We identified 69 exosomal proteins that were differentially expressed between MCI patients and healthy controls using mass spectrometry analysis. Thirty-nine exosomal proteins were upregulated in MCI patients compared with those in control patients. Exosomal fibulin-1, with an area under the curve value of 0.81, may be a biomarker for an MCI diagnosis. The exosomal protein signature from MCI patients reflected the cell adhesion molecule category. In particular, higher exosomal fibulin-1 levels correlated with lower cognitive performance. Thus, this study revealed that exosomal fibulin-1 is a promising biomarker for diagnosing MCI.

Investigation of isoflavone constituents from tuber of Apios americana Medik and its protective effect against oxidative damage on RIN-m5F cells.

In our previous study, AI-3, a mixture of isoflavones, was obtained from Apios Americana Medik tuber and showed strong protective ability on oxidative damaged RIN-m5F cells. This study aimed to identify the main compounds of AI-3 and elucidate their activities and underlying mechanism. In results, eleven compounds were purified from AI-3. Among them, Compound 8 (2'-Hydroxy, 5-methoxy genistein-7-O-glucoside, HMG) was the most effective compound against H2O2-induced injury in RIN-m5F cells (stronger than positive control α-LA). Further RNA-seq analysis found that compared with H2O2 group, 388 differentially expressed genes (DEGs) were identified in HMG group. The enrichment analyses revealed fluid shear stress and atherosclerosis pathway and hepatocellular carcinoma pathway enriched the most DEGs, in which HOX-1, GST, NQO1, SQSTM, TrxR1 were significantly up-regulated. The finding indicated Keap1-Nrf2-ARE signaling pathway may play essential role in the protective effect of HMG on oxidative damaged RIN-m5F cells.

Photosensitizers with aggregation-induced far-red/near-infrared emission for versatile visualization and broad-spectrum photodynamic killing of pathogenic microbes.

The exploration of photosensitizers with aggregation-induced emission (AIE PSs) for efficient visualization and broad-spectrum photodynamic killing of pathogenic microbes is a significant task. Herein, two far-red/near-infrared AIE-active PSs (TBTPy and TBTCy) were attained to show efficient Type I and Type II ROS generation, benefiting from the efficient ISC processes. The attained AIE PSs, especially TBTPy with bright emission, showed advantages in discriminating G+ bacteria over G- bacteria, and distinguishing dead E. coli from lived one. Both TBTPy and TBTCy have the capacity of broad-spectrum photodynamic killing of pathogenic microbes in vitro with considerable safety for mammalian cells. Antimicrobial mechanism is found to be changing osmotic pressure of cytoplasm in E. coli, causing cell deformation and destruction of S. aureus and C. albicans. In vivo anti-infection experiment demonstrated AIE PSs can accelerate the healing process of the burned wounds on rats infected by methicillin-resistant S. aureus (MRSA) or E. coli, indicating their potential to treat tertiary burns in clinical application. Therefore, the attained AIE PSs hold great promise as antimicrobial candidates in infective therapeutic application.

Broadband-excited and green-red tunable emission in Eu2+-sensitized Ca8MnTb(PO4)7 phosphors induced by structural-confined cascade energy transfer.

Novel green-red color-tunable Ca8(Mg,Mn)Tb(PO4)7:Eu2+ phosphors have been synthesized via the traditional solid-state method. Since Tb3+/Mn2+ ions are the parent ions in the lattice, the structural confinement occurs when the sensitizer Eu2+ is introduced into the Ca8(Mg,Mn)Tb(PO4)7:Eu2+ structure. The distance from Eu2+ to Tb3+/Mn2+ is confined in the 5 Å range, which induces a highly efficient energy transfer process. At Eu2+ 350 nm excitation, Ca8MgTb(PO4)7:Eu2+ shows dominant Tb3+ green emission with almost-vanished Eu2+ emission. Red emission is clearly observed as Mn2+ ions doping into Ca8MgTb(PO4)7:Eu2+, and color-tuning from green to red is realized by varying the Mn2+ contents. Eu2+-Tb3+-Mn2+ cascade energy transfer process is in effect due to short Eu2+-Tb3+/Mn2+ and Tb3+-Mn2+ distances, which is verified by PL and decay variations. Meanwhile, the Ca8(Mg,Mn)Tb(PO4)7:Eu2+ phosphor indicates good thermal stability and maintained the 45% emission level at 150 °C, which demonstrates their potential applications in white light LEDs.

VPS34-IN1 induces apoptosis of ER+ breast cancer cells via activating PERK/ATF4/CHOP pathway.

VPS34-IN1 is a specific selective inhibitor of Class III Phosphatidylinositol 3-kinase (PI3K) and has been shown to exhibit a significant antitumor effect in leukemia and liver cancer. In current study, we focused on the anticancer effect and potential mechanism of VPS34-IN1 in estrogen receptor positive (ER+ ) breast cancer. Our results revealed that VPS34-IN1 inhibited the viability of ER+ breast cancer cells in vitro and in vivo. Flow cytometry and western blot analyses showed that VPS34-IN1 treatment induced breast cancer cell apopotosis. Interestingly, VPS34-IN1 treatment activated protein kinase R (PKR)-like ER kinase (PERK) branch of endoplasmic reticulum (ER) stress. Furthermore, knockdown of PERK by siRNA or inhibition of PERK activity by chemical inhibitor GSK2656157 could attenuate VPS34-IN1-mediated apoptosis in ER+ breast cancer cells. Collectively, VPS34-IN1 has an antitumor effect in breast cancer, and it may result from activating PERK/ATF4/CHOP pathway of ER stress to induce cell apoptosis. These findings broaden our understanding of the anti-breast cancer effects and mechanisms of VPS34-IN1 and provide new ideas and reference directions for the treatment of ER+ breast cancer.

Celastrol targets the ChREBP-TXNIP axis to ameliorates type 2 diabetes mellitus.

BACKGROUNDS: Thioredoxin-interacting protein (TXNIP) plays a pivotal role in regulation of blood glucose homeostasis and is an emerging therapeutic target in diabetes and its complications. Celastrol, a pentacyclic triterpene extracted from the roots of Tripterygium wilfordii Hook F, can reduce insulin resistance and improve diabetic complications. PURPOSE: This study aimed to untangle the mechanism of celastrol in ameliorating type 2 diabetes (T2DM) and evaluate its potential benefits as an anti-diabetic agent. METHODS: db/db mice was used to evaluate the hypoglycemic effect of celastrol in vivo; Enzyme-linked immunosorbent assay (ELISA) and 2-NBDG assay were used to detect the effect of celastrol on insulin secretion and glucose uptake in cells; Western blotting, quantitative reverse transcription PCR (RT-qPCR) and immunohistological staining were used to examine effect of celastrol on the expression of TXNIP and the carbohydrate response element-binding protein (ChREBP). Molecular docking, cellular thermal shift assay (CETSA), drug affinity responsive targets stability assay (DARTS) and mass spectrometry were used to test the direct binding between celastrol and ChREBP. Loss- and gain-of-function studies further confirmed the role of ChREBP and TXNIP in celastrol-mediated amelioration of T2DM. RESULTS: Celastrol treatment significantly reduced blood glucose level, body weight and food intake, and improved glucose tolerance in db/db mice. Moreover, celastrol promoted insulin secretion and improved glucose homeostasis. Mechanistically, celastrol directly bound to ChREBP, a primary transcriptional factor upregulating TXNIP expression. By binding to ChREBP, celastrol inhibited its nuclear translocation and promoted its proteasomal degradation, thereby repressing TXNIP transcription and ultimately ameliorating T2DM through breaking the vicious cycle of hyperglycemia deterioration and TXNIP overexpression. CONCLUSION: Celastrol ameliorates T2DM through targeting ChREBP-TXNIP aix. Our study identified ChREBP as a new direct molecular target of celastrol and revealed a novel mechanism for celastrol-mediated amelioration of T2DM, which provides experimental evidence for its possible use in the treatment of T2DM and new insight into diabetes drug development for targeting TXNIP.