Pericyte signaling via soluble guanylate cyclase shapes the vascular niche and microenvironment of tumors.

Pericytes and endothelial cells (ECs) constitute the fundamental components of blood vessels. While the role of ECs in tumor angiogenesis and the tumor microenvironment is well appreciated, pericyte function in tumors remains underexplored. In this study, we used pericyte-specific deletion of the nitric oxide (NO) receptor, soluble guanylate cyclase (sGC), to investigate via single-cell RNA sequencing how pericytes influence the vascular niche and the tumor microenvironment. Our findings demonstrate that pericyte sGC deletion disrupts EC-pericyte interactions, impairing Notch-mediated intercellular communication and triggering extensive transcriptomic reprogramming in both pericytes and ECs. These changes further extended their influence to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Inhibition of pericyte sGC has minimal impact on quiescent vessels but significantly increases the vulnerability of angiogenic tumor vessels to conventional anti-angiogenic therapy. In conclusion, our findings elucidate the role of pericytes in shaping the tumor vascular niche and tumor microenvironment and support pericyte sGC targeting as a promising strategy for improving anti-angiogenic therapy for cancer treatment.

Stimuli-Responsive mRNA Vaccines to Induce Robust CD8+ T Cell Response via ROS-Mediated Innate Immunity Boosting.

The messenger RNA (mRNA) vaccines hold great significance in contagion prevention and cancer immunotherapy. However, safely and effectively harnessing innate immunity to stimulate robust and durable adaptive immune protection is crucial, yet challenging. In this study, we synthesized a library of stimuli-responsive bivalent ionizable lipids (srBiv iLPs) with smart molecular blocks responsive to esterase, H2O2, cytochrome P450, alkaline phosphatase, nitroreductase, or glutathione (GSH), aiming to leverage physiological cues to trigger fast lipid degradation, promote mRNA translation, and induce robust antitumor immunity via reactive oxygen species (ROS)-mediated boosting. After subcutaneous immunization, esterase-responsive vaccine (eBiv-mVac) was rapidly internalized and transported into the draining lymph nodes. It then underwent fast decaging and self-immolative degradation in esterase-rich antigen-presenting cells, releasing sufficient mRNA for antigen translation and massive reactive quinone methides to elevate ROS levels. This resulted in broad activation of innate immunity to boost T cell response, prompting a large number of primed antigen-specific CD8+ T cells to circulate and infiltrate into tumors (>1000-fold versus unvaccinated control), thereby orchestrating innate and adaptive immunity to control tumor growth. Moreover, by further combining our vaccination strategy with immune checkpoint blockade, we demonstrated a synergism that significantly amplified the magnitude and function of antigen-specific CD8+ T cells. This, in turn, caused potent systemic antitumor efficacy and prolonged survival with high complete response rate in xenograft and metastasis models. Overall, our generalized stimuli-responsive mRNA delivery platform promises a paradigm shift in the design of potent vaccines for cancer immunotherapy, as well as effective and precise carriers for gene editing, protein replacement, and cell engineering.

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.

m6A-modified RIPK4 facilitates proliferation and cisplatin resistance in epithelial ovarian cancer.

BACKGROUND: Cisplatin (DDP)-based chemotherapy is a common chemotherapeutic regimen for the treatment of advanced epithelial ovarian cancer (EOC). However, most patients rapidly develop chemoresistance. N6-methyladenosine (m6A) is a pervasive RNA modification, and its specific role and potential mechanism in the regulation of chemosensitivity in EOC remain unclear. METHODS: The expression of RIPK4 and its clinicopathological impact were evaluated in EOC cohorts. The biological effects of RIPK4 were investigated using in vitro and in vivo models. RNA m6A quantification was used to measure total m6A levels in epithelial ovarian cancer cells. Luciferase reporter, MeRIP-qPCR, RIP-qPCR and actinomycin-D assays were used to investigate RNA/RNA interactions and m6A modification of RIPK4 mRNA. RESULTS: We demonstrated that RIPK4, an upregulated mRNA in EOC, acts as an oncogene in EOC cells by promoting tumor cell proliferation and DDP resistance at the clinical, database, cellular, and animal model levels. Mechanistically, METTL3 facilitates m6A modification, and YTHDF1 recognizes the specific m6A-modified site to prevent RIPK4 RNA degradation and upregulate RIPK4 expression. This induces NF-κB activation, resulting in tumor growth and DDP resistance in vitro and in vivo. CONCLUSIONS: Collectively, the present findings reveal a novel mechanism underlying the induction of DDP resistance by m6A-modified RIPK4, that may contribute to overcoming chemoresistance in EOC.

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.

The potential regulatory role of RNA methylation in ovarian cancer.

Updates in whole genome sequencing technologies have revealed various RNA modifications in cancer, among which RNA methylation is a frequent posttranscriptional modification. RNA methylation is essential for regulating biological processes such as RNA transcription, splicing, structure, stability, and translation. Its dysfunction is strongly associated with the development of human malignancies. Research advances with respect to the regulatory role of RNA modifications in ovarian cancer include N6-methyladenosine (m6A), 5-methylcytosine (m5C), N1-methyladenosine (m1A), and N7-methylguanosine (m7G). Numerous studies have demonstrated that epigenetic modifications of RNA can influence the progression and metastasis of ovarian cancer and may provide excellent targets for cancer therapy. This review highlights advances in research on RNA methylation modifications and ovarian cancer prognosis, carcinogenesis, and resistance, which could provide a theoretical foundation for designing therapeutic strategies for ovarian cancer based on RNA methylation modifications.

Reactive oxygen species-induced SIAH1 promotes granulosa cells' senescence in premature ovarian failure.

Reactive oxygen species (ROS) exposure triggers granulosa cells' (GCs) senescence, which is an important causal factor for premature ovarian failure (POF). However, underlying mechanism in this process remains unknown. In our study, we observed increased ROS levels in POF ovarian tissues, POF patient follicular GCs and cyclophosphamide (CTX) pretreated GCs. Correspondingly, increased SIAH1, reduced TRF2 and GC senescence were also found in these cases. Silencing of SIAH1 rescued ROS-induced TRF2 reduction and cell senescence in GCs. Moreover, SIAH1 co-localized with TRF2 in the cytoplasm, facilitating its ubiquitination degradation, further leading to telomere abnormalities in GCs. In conclusion, our findings indicate that ROS induces telomere abnormalities by augmenting SIAH1-mediated TRF2 degradation, leading to cell senescence in GCs in POF processing.

Delivery of engineered extracellular vesicles with miR-29b editing system for muscle atrophy therapy.

Muscle atrophy is a frequently observed complication, characterized by the loss of muscle mass and strength, which diminishes the quality of life and survival. No effective therapy except exercise is currently available. In our previous study, repressing miR-29b has been shown to reduce muscle atrophy. In our current study, we have constructed artificially engineered extracellular vesicles for the delivery of CRISPR/Cas9 to target miR-29b (EVs-Cas9-29b). EVs-Cas9-29b has shown a favorable functional effect with respect to miR-29b repression in a specific and rapid manner by gene editing. In in vitro conditions, EVs-Cas9-29b could protect against muscle atrophy induced by dexamethasone (Dex), angiotensin II (AngII), and tumor necrosis factor-alpha (TNF-α). And EVs-Cas9-29b introduced in vivo preserved muscle function in the well-established immobilization and denervation-induced muscle atrophy mice model. Our work demonstrates an engineered extracellular vesicles delivery of the miR-29b editing system, which could be potentially used for muscle atrophy therapy.

Neuron secrete exosomes containing miR-9-5p to promote polarization of M1 microglia in depression.

BACKGROUND: Neuroinflammation is an important component mechanism in the development of depression. Exosomal transfer of MDD-associated microRNAs (miRNAs) from neurons to microglia might exacerbate neuronal cell inflammatory injury. RESULTS: By sequence identification, we found significantly higher miR-9-5p expression levels in serum exosomes from MDD patients than healthy control (HC) subjects. Then, in cultured cell model, we observed that BV2 microglial cells internalized PC12 neuron cell-derived exosomes while successfully transferring miR-9-5p. MiR-9-5p promoted M1 polarization in microglia and led to over releasing of proinflammatory cytokines, such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), which exacerbated neurological damage. Furthermore, we identified suppressor of cytokine signaling 2 (SOCS2) as a direct target of miR-9-5p. Overexpression of miR-9-5p suppressed SOCS2 expression and reactivated SOCS2-repressed Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathways. Consistently, we confirmed that adeno-associated virus (AAV)-mediated overexpression of miR-9-5p polarized microglia toward the M1 phenotype and exacerbated depressive symptoms in chronic unpredictable mild stress (CUMS) mouse mode. CONCLUSION: MiR-9-5p was transferred from neurons to microglia in an exosomal way, leading to M1 polarization of microglia and further neuronal injury. The expression and secretion of miR-9-5p might be novel therapeutic targets for MDD.

Abnormalities in FGF family members and their roles in modulating depression-related molecules.

The role of the fibroblast growth factor (FGF) system in depression has received considerable attention in recent years. To understand the role of this system, it is important to identify the specific members of the FGF family that have been implicated and the various mechanisms that they modulated. Here, we review the role of FGFs in depression and integrate evidence from clinical and basic research. These data suggest that changes in the FGF family are involved in depression and possibly in a wider range of psychiatric disorders. We analyse the abnormalities of FGF family members in depression and their roles in modulating depression-related molecules. The role of the FGF family in depression and related disorders needs to be studied in more detail.

Pygo1 regulates pathological cardiac hypertrophy via a ß-catenin-dependent mechanism.

Wnt/ß-catenin signaling plays a key role in pathological cardiac remodeling in adults. The identification of a tissue-specific Wnt/ß-catenin interaction factor may provide a tissue-specific clinical targeting strategy. Drosophila Pygo encodes the core interaction factor of Wnt/ß-catenin. Two Pygo homologs (Pygo1 and Pygo2) have been identified in mammals. Different from the ubiquitous expression profile of Pygo2, Pygo1 is enriched in cardiac tissue. However, the role of Pygo1 in mammalian cardiac disease is yet to be elucidated. In this study, we found that Pygo1 was upregulated in human cardiac tissues with pathological hypertrophy. Cardiac-specific overexpression of Pygo1 in mice spontaneously led to cardiac hypertrophy accompanied by declined cardiac function, increased heart weight/body weight and heart weight/tibial length ratios, and increased cell size. The canonical ß-catenin/T-cell transcription factor 4 (TCF4) complex was abundant in Pygo1-overexpressing transgenic (Pygo1-TG) cardiac tissue, and the downstream genes of Wnt signaling, that is, Axin2, Ephb3, and c-Myc, were upregulated. A tail vein injection of ß-catenin inhibitor effectively rescued the phenotype of cardiac failure and pathological myocardial remodeling in Pygo1-TG mice. Furthermore, in vivo downregulated pygo1 during cardiac hypertrophic condition antagonized agonist-induced cardiac hypertrophy. Therefore, our study is the first to present in vivo evidence demonstrating that Pygo1 regulates pathological cardiac hypertrophy in a canonical Wnt/ß-catenin-dependent manner, which may provide new clues for tissue-specific clinical treatment via targeting this pathway.NEW & NOTEWORTHY In this study, we found that Pygo1 is associated with human pathological hypertrophy. Cardiac-specific overexpression of Pygo1 in mice spontaneously led to cardiac hypertrophy. Meanwhile, cardiac function was improved when expression of Pygo1 was interfered in hypertrophy-model mice. Our study is the first to present in vivo evidence demonstrating that Pygo1 regulates pathological cardiac hypertrophy in a canonical Wnt/ß-catenin-dependent manner, which may provide new clues for a tissue-specific clinical treatment targeting this pathway.

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.

18F-FDG uptake velocity but not uptake level is associated with progression of carotid plaque.

OBJECTIVES: The objective of this study was to evaluate whether baseline 18F-fluorodeoxyglucose (FDG) uptake is associated with carotid plaque progression. METHODS: A total of 156 subjects with carotid plaque were enrolled and underwent carotid magnetic resonance imaging (MRI) (at baseline and the 12-month follow-up) and positron emission tomography-computed tomography (PET-CT) (baseline). Carotid plaque progression was evaluated by two indices (the incidence of plaque progression and percentage of plaque increase) with three-dimensional (3D) imaging, while the 18F-FDG uptake was evaluated by the 18F-FDG uptake levels and 18F-FDG uptake velocity. The association between plaque progression and 18F-FDG uptake was investigated by the trend test and multivariate logistic regression analysis. RESULTS: Of the 156 subjects, 80 (51.3%) showed carotid plaque progression during the 12-month follow-up. Firstly, no association was found between 18F-FDG uptake levels and plaque progression. Secondly, significant differences in the incidence of plaque progression were observed among the groups with different uptake velocities, showing a significant decreasing trend ranging from high to intermediate to low (p = 0.002, trend test). After adjusting for covariates, an adequate prediction of the 18F-FDG uptake velocity for the incidence of plaque progression was revealed (OR = 0.682, p < 0.05). In addition, no association was found between the 18F-FDG uptake velocity and the percentage of plaque increase in the subjects with plaque progression (p = 0.757, trend test). CONCLUSIONS: Our findings suggest 18F-FDG uptake velocity is independently associated with the incidence of carotid plaque progression. Additionally, the 18F-FDG uptake velocity, as another important parameter of PET-CT, warrants further study in future clinical research. KEY POINTS: • The18F-FDG uptake levels were not associated with the carotid plaque progression. • The18F-FDG uptake velocity could predict the incidence of carotid plaque progression. • The18F-FDG uptake velocity with related factors warrants more attention in future clinical research.

Which is better for mothers and babies: fresh or frozen-thawed blastocyst transfer?

BACKGROUND: In recent years, there have been many reports on the pregnancy outcomes of fresh blastocyst transfer (BT) and frozen-thawed BT, but the conclusions are controversial and incomplete. To compare the pregnancy outcomes, maternal complications and neonatal outcomes of fresh and frozen-thawed BT in the context of in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles, we conducted a meta-analysis. METHODS: A meta-analysis was conducted by searching the PubMed, Embase, and Cochrane Library databases through May 2020. Data were extracted independently by two authors. RESULTS: Fifty-four studies, including 12 randomized controlled trials (RCTs), met the inclusion criteria. Fresh BT was associated with a lower implantation rate, pregnancy rate, ongoing pregnancy rate, and clinical pregnancy rate and higher ectopic pregnancy rate than frozen-thawed BT according to the results of the RCTs. The risks of moderate or severe ovarian hyperstimulation syndrome, placental abruption, placenta previa and preterm delivery were higher for fresh BT than for frozen-thawed BT. The risk of pregnancy-induced hypertension and pre-eclampsia was lower for fresh BT; however, no significant differences in risks for gestational diabetes mellitus and preterm rupture of membrane were found between the two groups. Compared with frozen-thawed BT, fresh BT appears to be associated with small for gestational age and low birth weight. No differences in the incidences of neonatal mortality or neonatal malformation were observed between fresh and frozen-thawed BT. CONCLUSIONS: At present there is an overall slight preponderance of risks in fresh cycles against frozen, however individualization is required and current knowledge does not permit to address a defintive response.

TIPE1 promotes cervical cancer progression by repression of p53 acetylation and is associated with poor cervical cancer outcome.

Previous studies have shown that TIPE1 inhibits tumor proliferation and metastasis in certain cancers; however, increased expression of TIPE1 is observed in cervical cancer cell lines and tissues, indicating it might exert a distinctive role in cervical cancer. Cell and xenograft tumorigenicity assays showed that TIPE1 facilitates cervical cancer progression in this study. Further investigation demonstrated that TIPE1 binds to p53 and impairs its activity via inhibition of its acetylation. In addition, TIPE1 promoted cell proliferation and suppressed cisplatin susceptibility in a p53-dependent manner, indicating that TIPE1 facilitates cervical cancer progression primarily through the p53 pathway. TIPE1 expression in clinical samples also demonstrated that its upregulation predicts poor prognosis in patients with cervical cancer. Taken together, the results of this study showed that TIPE1 serves as an oncogene by restricting p53 activity in the development of cervical cancer, suggesting that TIPE1 will provide a new potential target for cervical cancer therapy and can be used as a biomarker to predict patient prognosis.

Increased NHE1 expression is targeted by specific inhibitor cariporide to sensitize resistant breast cancer cells to doxorubicin in vitro and in vivo.

BACKGROUND: The Na+/H+ exchanger (NHE1) plays a crucial role in cancer cell proliferation and metastasis. However, the mechanism underlying chemotherapeutic resistance in cancer cells has not been completely elucidated. The NHE1 inhibitor cariporide has been demonstrated to inhibit human cancer cell lines. The goal of this study was to provide new sights into improved cancer cell chemosensitivity mediated by cariporide with activation of the apoptosis pathway. METHODS: The NHE1 expression levels were first evaluated using the online database Oncomine and were determined by RT-PCR and western blot in vitro and in vivo. Cell proliferation was assessed In vitro through a CCK-8 assay, and apoptosis was analyzed by flow cytometry. An in vivo analysis was performed in BALB/c nude mice, which were intraperitoneally injected with MCF-7/ADR cells. RESULTS: NHE1 levels were significantly higher in breast cancer tissue than adjacent tissue, as well as in resistant cancer cells compared to sensitive cells. Cariporide induced the apoptosis of MCF-7/ADR cells and was associated with the intracellular accumulation of doxorubicin and G0/G1 cell cycle arrest. Moreover, cariporide decreased MDR1 expression and activated cleaved caspase-3 and caspase-9, promoting caspase-independent apoptosis in vitro. In vivo, cariporide significantly improved doxorubicin sensitivity in a xenograft model, enhancing tumor growth attenuation and diminishing tumor volume. CONCLUSIONS: Our results demonstrate that cariporide significantly facilitates the sensitivity of breast cancer to doxorubicin both in vitro and in vivo. This finding suggests that NHE1 may be a novel adjuvant therapeutic candidate for the treatment of resistant breast cancer.

Heterogeneity of adult masseter muscle satellite cells with cardiomyocyte differentiation potential.

Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1+ MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1- MMSCs with Pax7 expression. Sca1+ MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement.

Downregulation of hypermethylated in cancer-1 by miR-4532 promotes adriamycin resistance in breast cancer cells.

BACKGROUND: MicroRNAs are small RNAs (~ 22 nt) that modulate the expression of thousands of genes in tumors and play important roles in the formation of multidrug resistance. In this study, we firstly investigated that miR-4532 involved in the multidrug resistance formation of breast cancer by targeting hypermethylated in cancer 1 (HIC-1), a tumor-suppressor gene. METHODS: To identify and characterize the possible miRNAs in regulating multidrug resistance, we employed the transcriptome sequencing approach to profile the changes in the expression of miRNAs and their target mRNAs were obtained by bioinformatics prediction. Then the molecular biology experiments were conducted to confirm miR-4532 involved in multidrug resistance formation of breast cancer. RESULTS: The luciferase reporter assay experiment was employed to confirm that HIC-1 was the target of miR-4532. Transfection with an miR-4532 mimic indicated miR-4532 mimic significantly increased breast cancer cell resistance to adriamycin. Cell proliferation and invasion assay experiments showed overexpression of HIC-1 inhibited the invasion and metastasis of breast cancer cells. Meanwhile, the interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3) signaling pathway was confirmed to be involving in multidrug resistance by western blotting experiments. CONCLUSIONS: These results suggest that downregulation of hypermethylated in cancer-1 by miR-4532 could promote adriamycin resistance in breast cancer cells, in which the IL-6/STAT3 pathway was regulated by the HIC-1. This finding might contribute to new therapeutic target for reversal of tumor resistance.