CD40 Expression by B cells is Required for Optimal Immunity to Murine Pneumocystis Infection.

CD40-CD40L interactions are critical for controlling Pneumocystis infection. However, which CD40-expressing cell populations are important for this interaction have not been well-defined. We used a cohousing mouse model of Pneumocystis infection, combined with flow cytometry and qPCR, to examine the ability of different populations of cells from C57BL/6 mice to reconstitute immunity in CD40 knockout (KO) mice. Unfractionated splenocytes, as well as purified B cells, were able to control Pneumocystis infection, while B cell depleted splenocytes and unstimulated bone-marrow derived dendritic cells (BMDCs) were unable to control infection in CD40 KO mice. Pneumocystis antigen-pulsed BMDCs showed early, but limited, control of infection. Consistent with recent studies that have suggested a role for antigen presentation by B cells, using cells from immunized animals, B cells were able to present Pneumocystis antigens to induce proliferation of T cells. Thus, CD40 expression by B cells appears necessary for robust immunity to Pneumocystis.

Microglia-derived exosomes selective sorted by YB-1 alleviate nerve damage and cognitive outcome in Alzheimer's disease.

BACKGROUND: Neuroinflammation is a characteristic pathological change of Alzheimer's Diseases (AD). Microglia have been reported to participate in inflammatory responses within the central nervous system. However, the mechanism of microglia released exosome (EXO) contribute to communication within AD microenvironment remains obscure. METHODS: The interaction between microglia and AD was investigated in vitro and in vivo. RNA-binding protein immunoprecipitation (RIP) was used to investigate the mechanisms of miR-223 and YB-1. The association between microglia derived exosomal YB-1/miR-223 axis and nerve cell damage were assessed using Western blot, immunofluorescence, RT-PCR, ELISA and wound healing assay. RESULTS: Here, we reported AD model was responsible for the M1-like (pro-inflammatory) polarization of microglia which in turn induced nerve cell damage. While M2-like (anti-inflammatory) microglia could release miR-223-enriched EXO which reduced neuroinflammation and ameliorated nerve damage in AD model in vivo and in vitro. Moreover, YB-1 directly interacted with miR-223 both in cell and EXO, and participated in microglia exosomal miR-223 loading. CONCLUSION: These results indicate that anti-inflammatory microglia-mediated neuroprotection form inflammatory damage involves exporting miR-223 via EXO sorted by YB-1. Consequently, YB-1-mediated microglia exosomal sorting of miR-223 improved the nerve cell damage repair, representing a promising therapeutic target for AD.

Exosomal YB-1 facilitates ovarian restoration by MALAT1/miR-211-5p/FOXO3 axis.

Premature ovarian failure (POF) affects many adult women less than 40 years of age and leads to infertility. Mesenchymal stem cells-derived small extracellular vesicles (MSCs-sEVs) are attractive candidates for ovarian function restoration and folliculogenesis for POF due to their safety and efficacy, however, the key mediator in MSCs-sEVs that modulates this response and underlying mechanisms remains elusive. Herein, we reported that YB-1 protein was markedly downregulated in vitro and in vivo models of POF induced with H2O2 and CTX respectively, accompanied by granulosa cells (GCs) senescence phenotype. Notably, BMSCs-sEVs transplantation upregulated YB-1, attenuated oxidative damage-induced cellular senescence in GCs, and significantly improved the ovarian function of POF rats, but that was reversed by YB-1 depletion. Moreover, YB-1 showed an obvious decline in serum and GCs in POF patients. Mechanistically, YB-1 as an RNA-binding protein (RBP) physically interacted with a long non-coding RNA, MALAT1, and increased its stability, further, MALAT1 acted as a competing endogenous RNA (ceRNA) to elevate FOXO3 levels by sequestering miR-211-5p to prevent its degradation, leading to repair of ovarian function. In summary, we demonstrated that BMSCs-sEVs improve ovarian function by releasing YB-1, which mediates MALAT1/miR-211-5p/FOXO3 axis regulation, providing a possible therapeutic target for patients with POF.

M6A demethylase FTO-stabilized exosomal circBRCA1 alleviates oxidative stress-induced granulosa cell damage via the miR-642a-5p/FOXO1 axis.

BACKGROUND: Premature ovarian insufficiency (POI) is an important cause of female infertility and seriously impacts the physical and psychological health of patients. Human umbilical cord mesenchymal stem cell-derived exosomes (HucMSCs-Exs, H-Exs) have exhibited protective effects on ovarian function with unclear mechanisms. METHODS: A comprehensive analysis of the Gene Expression Omnibus (GEO) database were used to identify POI-associated circRNAs and miRNAs. The relationship between HucMSC-derived exosomal circBRCA1/miR-642a-5p/FOXO1 axis and POI was examined by RT-qPCR, Western blotting, reactive oxygen species (ROS) staining, senescence-associated ß-gal (SA-ß-gal) staining, JC-1 staining, TEM, oxygen consumption rate (OCR) measurements and ATP assay in vivo and in vitro. RT-qPCR detected the expression of circBRCA1 in GCs and serum of patients with normal ovarian reserve function (n = 50) and patients with POI (n = 50); then, the correlation of circBRCA1 with ovarian reserve function indexes was analyzed. RESULTS: Herein, we found that circBRCA1 was decreased in the serum and ovarian granulosa cells (GCs) of patients with POI and was associated with decreased ovarian reserve. H-Exs improved the disorder of the estrous cycles and reproductive hormone levels, reduced the number of atretic follicles, and alleviated the apoptosis and senescence of GCs in rats with POI. Moreover, H-Exs mitigated mitochondrial damage and reversed the reduced circBRCA1 expression induced by oxidative stress in GCs. Mechanistically, FTO served as an eraser to increase the stability and expression of circBRCA1 by mediating the m6A demethylation of circBRCA1, and exosomal circBRCA1 sponged miR-642a-5p to block its interaction with FOXO1. CircBRCA1 insufficiency aggravated mitochondrial dysfunction, mimicking FTO or FOXO1 depletion effects, which was counteracted by miR-642a-5p inhibition. CONCLUSION: H-Exs secreted circBRCA1 regulated by m6A modification, directly sponged miR-642a-5p to upregulate FOXO1, resisted oxidative stress injuries in GCs and protected ovarian function in rats with POI. Exosomal circBRCA1 supplementation may be a general prospect for the prevention and treatment of POI.

Application Effect of Patient-centered Health Education in Patients with Type 2 Diabetes Accompanied by Hyperlipidemia.

Objective: This study aims to investigate the impact of patient-centered health education on individuals with type 2 diabetes coexisting with hyperlipidemia. Methods: A cohort of 80 patients with type 2 diabetes and hyperlipidemia attending our hospital from February 2022 to August 2022 were randomly assigned to either the health education group or the control group. While the control group received routine health education, the health education group received additional patient-centered health education. Subsequently, we compared blood glucose and lipid levels, negative emotions, quality of life, and the incidence of unhealthy eating or overweight between the two groups post-education. Results: Following the health education intervention, the health education group exhibited superior improvements in blood glucose and lipid levels compared to the control group. Moreover, there was a significant decrease in SAS and SDS scores and a notable increase in quality of life compared to the control group. The health education group also demonstrated a lower incidence of unhealthy eating or overweight. Conclusions: Patient-centered health education for individuals with type 2 diabetes and hyperlipidemia proves effective in enhancing glucose and lipid metabolism, mitigating negative emotions, improving quality of life, and reducing unhealthy habits.

Effects of motivational interviewing intervention on psychological status, compliance behavior and quality of life of patients with malignant tumor combined with diabetes mellitus.

Objective: To investigate the effects of motivational interview education on psychological status, compliance behavior and quality of life in patients with malignant tumors combined with diabetes mellitus. Methods: This is a retrospective study. Eighty patients with malignant tumors combined with diabetes mellitus admitted at The Fourth Hospital of Hebei Medical University from January 2021 to June 2022 were included as subjects and divided into observation group and control group according to the intervention measures. Patients in the control group were given routine health education intervention, while those in the observation group were given motivational interviewing intervention on the basis of the control group. We compared the prognosis, cognitive function, quality of life, relief of cancer pain before intervention and three months after the intervention of the two groups were compared. Results: At three months after the intervention, the total remission rate of cancer pain in the observation group was higher than that in the control group(p<0.05), while the levels of FBG and 2hPG in the observation group were significantly lower than those in the control group(p<0.05). Self-Rating Anxiety Scale(SAS) and Self-rating depression scale(SDS) scores decreased in both groups three months after the intervention, with the level of reduction in the observation group being higher than that in the control group(p<0.05). The overall compliance was higher in the observation group than in the control group(p<0.05). Conclusion: Motivational interviewing leads to alleviate negative emotions, improve the psychological status, enhance compliance behavior and improve quality of life in patients with malignant tumors combined with diabetes mellitus.

The early stage of adult ocular dominance plasticity revealed by near-infrared optical imaging of intrinsic signals.

Long term monocular deprivation is considered to be necessary for the induction of significant ocular dominance plasticity in the adult visual cortex. In this study, we subjected adult mice to monocular deprivation for various durations and screened for changes in ocular dominance using dual-wavelength intrinsic signal optical imaging. We found that short-term deprivation was sufficient to cause a shift in ocular dominance and that these early-stage changes were detected only by near-infrared illumination. In addition, single-unit recordings showed that these early-stage changes primarily occurred in deep cortical layers. This early-stage ocular dominance shift was abolished by the blockade of NMDA receptors. In summary, our findings reveal an early phase of adult ocular dominance plasticity and provide the dynamics of adult plasticity.

Prolactin Regulates Ovine Ovarian Granulosa Cell Apoptosis by Affecting the Expression of MAPK12 Gene.

Prolactin (PRL) has been reported to influence reproductive performance and cell apoptosis. However, its mechanism remains unclear. Hence, in the present study, ovine ovarian granulosa cells (GCs) were used as a cell model to investigate the relationship between PRL concentration and GC apoptosis, as well as its possible mechanisms. We examined the relationship between serum PRL concentration and follicle counts in sexually mature ewes. GCs were isolated from adult ewes and treated with different concentrations of PRL, while 500 ng/mL PRL was selected as the high concentration of prolactin (HPC). Then, we applied the transcriptome sequencing (RNA-Seq) combined with a gene editing approach to explore the HPC contributing to cell apoptosis and steroid hormones. The apoptosis of GCs gradually increased at PRL concentrations above 20 ng/mL, while 500 ng/mL PRL significantly decreased the secretion of steroid hormones and the expression of L-PRLR and S-PRLR. The results indicated that PRL regulates GC development and steroid hormones mainly through the target gene MAPK12. The expression of MAPK12 was increased after knocked-down L-PRLR and S-PRLR, while it decreased after overexpressed L-PRLR and S-PRLR. Cell apoptosis was inhibited and the secretion of steroid hormones increased after interfering with MAPK12, while the overexpression of MAPK12 showed the opposite trend. Overall, the number of follicles gradually decreased with increasing PRL concentration. HPCs promoted apoptosis and inhibited steroid hormone secretion in GCs by upregulating MAPK12 through reducing L-PRLR and S-PRLR.

Modulation of Visual Responses and Ocular Dominance by Contralateral Inhibitory Activation in the Mouse Visual Cortex.

Both hemispheres connect with each other by excitatory callosal projections, and whether inhibitory interneurons, usually believed to have local innervation, engage in transcallosal activity modulation is unknown. Here, we used optogenetics in combination with cell-type-specific channelrhodopsin-2 expression to activate different inhibitory neuron subpopulations in the visual cortex and recorded the response of the entire visual cortex using intrinsic signal optical imaging. We found that optogenetic stimulation of inhibitory neurons reduced spontaneous activity (increase in the reflection of illumination) in the binocular area of the contralateral hemisphere, although these stimulations had different local effects ipsilaterally. The activation of contralateral interneurons differentially affected both eye responses to visual stimuli and, thus, changed ocular dominance. Optogenetic silencing of excitatory neurons affects the ipsilateral eye response and ocular dominance in the contralateral cortex to a lesser extent. Our results revealed a transcallosal effect of interneuron activation in the mouse visual cortex.

High Prolactin Concentration Induces Ovarian Granulosa Cell Oxidative Stress, Leading to Apoptosis Mediated by L-PRLR and S-PRLR.

High prolactin (PRL) concentration has been shown to induce the apoptosis of ovine ovarian granulosa cells (GCs), but the underlying mechanisms are unclear. This study aimed to investigate the mechanism of apoptosis induced by high PRL concentration in GCs. Trial 1: The optimal concentration of glutathion was determined according to the detected cell proliferation. The results showed that the optimal glutathione concentration was 5 µmol/mL. Trial 2: 500 ng/mL PRL was chosen as the high PRL concentration. The GCs were treated with 0 ng/mL PRL (C group), 500 ng/mL PRL (P group) or 500 ng/mL PRL, and 5 µmol/mL glutathione (P-GSH group). The results indicated that the mitochondrial respiratory chain complex (MRCC) I-V, ATP production, total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and thioredoxin peroxidase (TPx) in the C group were higher than those in the P group (p < 0.05), while they were lower than those in the P-GSH group (p < 0.05). Compared to the C group, the P group exhibited elevated levels of reactive oxygen species (ROS) and apoptosis (p < 0.05) and increased expression of ATG7 and ATG5 (p < 0.05). However, MRCC I-V, ATP, SOD, A-TOC, TPx, ROS, and apoptosis were decreased after the addition of glutathione (p < 0.05). The knockdown of either L-PRLR or S-PRLR in P group GCs resulted in a significant reduction (p < 0.05) in MRCC I-V, ATP, T-AOC, SOD and TPx, while the overexpression of either receptor showed an opposite trend (p < 0.05). Our findings suggest that high PRL concentrations induce apoptotic cell death in ovine ovarian GCs by downregulating L-PRLR and S-PRLR, activating oxidative stress and autophagic pathways.

Unravelling the distinct biological functions and potential therapeutic applications of TIMP2 in cancer.

Tissue inhibitors of metalloproteinases (TIMPs) are a conserved family of proteins that were originally identified as endogenous inhibitors of matrixin and adamalysin endopeptidase activity. The matrixins and adamalysins are the major mediators of extracellular matrix (ECM) turnover, thus making TIMPs important regulators of ECM structure and composition. Despite their high sequence identity and relative redundancy in inhibitory profiles, each TIMP possesses unique biological characteristics that are independent of their regulation of metalloproteinase activity. As our understanding of TIMP biology has evolved, distinct roles have been assigned to individual TIMPs in cancer progression. In this respect, data regarding TIMP2's role in cancer have borne conflicting reports of both tumor suppressor and, to a lesser extent, tumor promoter functions. TIMP2 is the most abundant TIMP family member, prevalent in normal and diseased mammalian tissues as a constitutively expressed protein. Despite its apparent stable expression, recent work highlights how TIMP2 is a cell stress-induced gene product and that its biological activity can be dictated by extracellular posttranslational modifications. Hence an understanding of TIMP2 molecular targets, and how its biological functions evolve in the progressing tumor microenvironment may reveal new therapeutic opportunities. In this review, we discuss the continually evolving functions of TIMP proteins, future perspectives in TIMP research, and the therapeutic utility of this family, with a particular focus on TIMP2.

Bispecific antibody simultaneously targeting PD1 and HER2 inhibits tumor growth via direct tumor cell killing in combination with PD1/PDL1 blockade and HER2 inhibition.

Immune checkpoint blockade has shown significant clinical benefit in multiple cancer indications, but many patients are either refractory or become resistant to the treatment over time. HER2/neu oncogene overexpressed in invasive breast cancer patients associates with more aggressive diseases and poor prognosis. Anti-HER2 mAbs, such as trastuzumab, are currently the standard of care for HER2-overexpressing cancers, but the response rates are below 30% and patients generally suffer relapse within a year. In this study we developed a bispecific antibody (BsAb) simultaneously targeting both PD1 and HER2 in an attempt to combine HER2-targeted therapy with immune checkpoint blockade for treating HER2-positive solid tumors. The BsAb was constructed by fusing scFvs (anti-PD1) with the effector-functional Fc of an IgG (trastuzumab) via a flexible peptide linker. We showed that the BsAb bound to human HER2 and PD1 with high affinities (EC50 values were 0.2 and 0.14 nM, respectively), and exhibited potent antitumor activities in vitro and in vivo. Furthermore, we demonstrated that the BsAb exhibited both HER2 and PD1 blockade activities and was effective in killing HER2-positive tumor cells via antibody-dependent cellular cytotoxicity. In addition, the BsAb could crosslink HER2-positive tumor cells with T cells to form PD1 immunological synapses that directed tumor cell killing without the need of antigen presentation. Thus, the BsAb is a new promising approach for treating late-stage metastatic HER2-positive cancers.

LncGSAR Controls Ovarian Granulosa Cell Steroidogenesis via Sponging MiR-125b to Activate SCAP/SREBP Pathway.

Long non-coding RNAs (lncRNAs) have been shown to play important roles in livestock fecundity, and many lncRNAs that affect follicular development and reproductive diseases have been identified in the ovary. However, only a few of them have been functionally annotated and mechanistically validated. In this study, we identified a new lncRNA (lncGSAR) and investigated its effects on the proliferation and steroidogenesis of ovine granulosa cells (GCs). High concentrations of glucose (add 33.6 mM glucose) caused high expression of lncGSAR in GCs by regulating its stability, and lncGSAR overexpression promoted GCs proliferation, estrogen secretion, and inhibited progesterone secretion, whereas interference with lncGASR had the opposite effect. Next, we found that the RNA molecules of lncGSAR act on MiR-125b as competitive endogenous RNA (ceRNA), and SREBP-cleavage-activating protein (SCAP) was verified as a target of MiR-125b. LncGASR overexpression increased the expression of SCAP, SREBP, and steroid hormone-related proteins, which can be attenuated by MiR-125b. Our results demonstrated that lncGSAR can act as a ceRNA to activate SCAP/SREBP signaling by sponging MiR-125b to regulate steroid hormone secretion in GCs. These findings provide new insights into the mechanisms of nutrient-regulated follicle development in ewes.

Long Non-Coding RNA GDAR Regulates Ovine Granulosa Cells Apoptosis by Affecting the Expression of Apoptosis-Related Genes.

Short-term dietary supplementation of ewes during the luteal phase can increase fertility, most probably by stimulating glucose uptake by the follicles. However, the molecular mechanism of glucose regulation of follicular development has not yet been clarified, especially the further study of long non-coding RNA (lncRNA) in determining fertility during follicular development. We generated granulosa cell (GC) models of different doses of glucose (0, 2.1, 4.2, 8.4, 16.8 and 33.6 mM), and observed that the highest cell viability was recorded in the 8.4 mM group and the highest apoptosis rates were recorded in the 33.6 mM group. Therefore, a control group (n = 3, 0 mM glucose), a low glucose group (n = 3, add 8.4 mM glucose), and a high glucose group (n = 3, add 33.6 mM glucose) of GCs were created for next whole genomic RNA sequencing. In total, 18,172 novel lncRNAs and 510 annotated lncRNAs were identified in the GCs samples. Gene Ontology indicated that differentially expressed lncRNAs associated with cell apoptosis were highly enriched. Kyoto Encyclopedia of Genes and Genomes enrichment analysis of lncRNA target genes found that the apoptosis pathway and the p53 signaling pathway were both enriched. Furthermore, we focused on the function of a lncGDAR and verified that lncGDAR could influence cell apoptosis in GC development through affecting the mRNA and protein expression of apoptosis-related markers. These results provide the basis for further study of the lncRNA regulation mechanism in nutrition on female fertility.

MUC1 mediates Pneumocystis murina binding to airway epithelial cells.

Previous studies have shown that Pneumocystis binds to pneumocytes, but the proteins responsible for binding have not been well defined. Mucins are the major glycoproteins present in mucus, which serves as the first line of defence during airway infection. MUC1 is the best characterised membrane-tethered mucin and is expressed on the surface of most airway epithelial cells. Although by electron microscopy Pneumocystis primarily binds to type I pneumocytes, it can also bind to type II pneumocytes. We hypothesized that Pneumocystis organisms can bind to MUC1 expressed by type II pneumocytes. Overexpression of MUC1 in human embryonic kidney HEK293 cells increased Pneumocystis binding, while knockdown of MUC1 expression by siRNA in A549 cells, a human adenocarcinoma-derived alveolar type II epithelial cell line, decreased Pneumocystis binding. Immunofluorescence labelling indicated that MUC1 and Pneumocystis were co-localised in infected mouse lung tissue. Incubation of A549 cells with Pneumocystis led to phosphorylation of ERK1/2 that increased with knockdown of MUC1 expression by siRNA. Pneumocystis caused increased IL-6 and IL-8 secretion by A549 cells, and knockdown of MUC1 further increased their secretion in A549 cells. Taken together, these results suggest that binding of Pneumocystis to MUC1 expressed by airway epithelial cells may facilitate establishment of productive infection.

Evaluation of genetic diversity and development of core collections of industrial brewing yeast using ISSR markers.

Germplasm of industrial brewing yeast of the worldwide have a richer diversity, and various successes in improving the performance of brewing yeasts. However, they are limited in that they have relatively low odds of combining desirable traits in a correct manner. To improve germplasm resource preservation, management, and utilization efficiency. In this study, the genetic diversity of 35 industrial brewing yeasts were analyzed based upon inter simple sequence repeat (ISSR) markers, in which 151 out of 167 SSR loci (90.42%) were polymorphic between two or more strains. Three preliminary core collections were established using ISSR data, and based on three different strategies as follows: an advanced maximization (M) strategy, an allele preferred sampling (A) strategy, and a random sampling (R) strategy. Comparison of genetic parameters, including polymorphic information content, Nei's genetic diversity (H), effective allele number, observed allele number, Shannon's index (I), and principal coordinate analyses, confirmed that all the core collections accurately recapitulated the diversity of the initial germplasm. Considering the loci retention ratio and trait coverage efficiency, Core1 was considered the best core collection.

Inhibition of Cdk5 in PV Neurons Reactivates Experience-Dependent Plasticity in Adult Visual Cortex.

Cyclin-dependent kinase 5 (Cdk5) has been shown to play a critical role in brain development, learning, memory and neural processing in general. Cdk5 is widely distributed in many neuron types in the central nervous system, while its cell-specific role is largely unknown. Our previous study showed that Cdk5 inhibition restored ocular dominance (OD) plasticity in adulthood. In this study, we specifically knocked down Cdk5 in different types of neurons in the visual cortex and examined OD plasticity by optical imaging of intrinsic signals. Downregulation of Cdk5 in parvalbumin-expressing (PV) inhibitory neurons, but not other neurons, reactivated adult mouse visual cortical plasticity. Cdk5 knockdown in PV neurons reduced the evoked firing rate, which was accompanied by an increment in the threshold current for the generation of a single action potential (AP) and hyperpolarization of the resting membrane potential. Moreover, chemogenetic activation of PV neurons in the visual cortex can attenuate the restoration of OD plasticity by Cdk5 inhibition. Taken together, our results suggest that Cdk5 in PV interneurons may play a role in modulating the excitation and inhibition balance to control the plasticity of the visual cortex.

Bone marrow mesenchymal stem cell-derived exosomal miR-144-5p improves rat ovarian function after chemotherapy-induced ovarian failure by targeting PTEN.

Chemotherapy-induced premature ovarian failure (POF) in women is currently clinically irreversible. Bone marrow mesenchymal stem cells (BMSCs) are a promising cellular therapeutic strategy for POF. However, the underlying mechanism governing the efficacy of BMSCs in treating POF has not been determined. In this study, we show that BMSC and BMSC-derived exosome transplantation can significantly recover the estrus cycle, increase the number of basal and sinus follicles in POF rats, increase estradiol (E2) and anti-Mullerian hormone (AMH) levels, and reduce follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels in the serum. Furthermore, we demonstrate that BMSC-derived exosomes prevent ovarian follicular atresia in cyclophosphamide (CTX)-treated rats via the delivery of miR-144-5p, which can be transferred to cocultured CTX-damaged granulosa cells (GCs) to decrease GC apoptosis. A functional assay revealed that overexpression of miR-144-5p in BMSCs showed efficacy against CTX-induced POF, and the improvement in the repair was related to the inhibition of GC apoptosis by targeting PTEN. The opposite effect was exhibited when miR-144-5p was inhibited. Taken together, our experimental results provide new information regarding the potential of using exosomal miR-144-5p to treat ovarian failure.

A nuclear lncRNA Linc00839 as a Myc target to promote breast cancer chemoresistance via PI3K/AKT signaling pathway.

Chemoresistance has become a leading cause of mortality in breast cancer patients and is one of the major obstacles for improving the clinical outcome. Long noncoding RNAs play important roles in breast cancer tumorigenesis and chemoresistance. However, the involvement and regulation of lncRNAs in breast cancer chemoresistance are not completely understood. Here, we reported that Linc00839 was localized in the nucleus and upregulated in chemoresistant breast cancer cells and tissues, and high level of Linc00839 was associated with a poor prognosis. Knockdown of Linc00839 significantly suppressed proliferation, invasion, and migration, sensitized cells to paclitaxel in vitro and inhibited transplant tumor development in vivo. Mechanistically, we found that Myc could directly bind to the promoter region of Linc00839 and activate its transcription. Furthermore, Linc00839 overexpression increased the expression of Myc and the RNA-binding protein Lin28B and activated the PI3K/AKT signaling pathway. We also discovered that Lin28B positively interacted with Linc00839 and was upregulated in breast cancer tissues. Taken together, for the first time, we showed that Linc00839 was activated by Myc and promoted proliferation and chemoresistance in breast cancer through binding with Lin28B. These findings provide new insight into the regulatory mechanism of Linc00839 and propose a Myc/Linc00839/Lin28B feedback loop that could be used as a novel therapeutic target for breast cancer.

Retraction Note to: Bio­HMGB1 from breast cancer contributes to M­MDSC differentiation from bone marrow progenitor cells and facilitates conversion of monocytes into MDSC­like cells.

The Editor-in-Chief has retracted this article.