Advances in the study of microparticles in diabetic retinopathy.

Diabetic retinopathy (DR) is one of the common diabetic microangiopathies, which severely impairs vision in diabetic population. The underlying mechanisms regarding the development of DR are not fully understood, and there is a lack of biomarkers to guide clinical, assessment of disease progression. Recently researchers have found that microparticles (MP) and its bioactive molecules are involved in the development of DR. MP is widely distributed in the circulation and can exert autocrine and paracrine benefits in intercellular signalling, provide a catalytic platform for the thrombospondin complex to promote coagulation, and promote the accumulation of reactive oxygen species to cause endothelial damage. MP interacts with advanced glycosylation end products (AGE) and AGE receptor (RAGE) to activate inflammatory pathways. MP carries a variety of miRNAs that regulate the vascular endothelial growth factor generation pathway. MP has also been applied to the exploration of mesenchymal stromal cell replacement therapy to treat DR. In a word, MP provides new ideas for the study of DR. MP has emerged as a marker to assess the progression of DR. As a potential therapeutic target, MP also has considerable research value.

IFI35 limits antitumor immunity in triple-negative breast cancer via CCL2 secretion.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with poor prognosis due to the lack of therapeutic targets. Although immunotherapy brings survival benefits to patients diagnosed with TNBC, it remains limited and treatment resistance is widespread. Here we demonstrate that IFI35 is highly expressed in tumor tissues and can be induced by Interferon-γ in a time-dependent and concentration-dependent manner in breast cancer cells. In xenograft models, we reveal that IFI35 dramatically increases myeloid-derived suppressor cells infiltration in tumors, along with depletion and anergy of CD8+T cells. IFI35 ablation leads to prolonged survival of the mice. Mechanistically, RNA-sequencing reveals that IFI35 promotes CCL2 secretion, resulting in the remodeling of TNBC immune microenvironment. Ablation of IFI35 promotes the infiltration of effector CD8+T cells, and thereby sensitizes TNBC to anti-PD-1 immunotherapy. Our data suggest that IFI35 limits antitumor immunity and may be expected to become a new immunotherapy target in TNBC.

Ultrasound-assisted macroporous resin treatment improves the color and functional properties of sunflower meal protein.

Sunflower meal protein (SMP) has been considered as a high-quality source of plant protein. However, because the chlorogenic acid (CA) contained in sunflower seed meal was prone to oxidation reactions under traditional alkali extraction conditions, the extracted protein has a dark color and some poor functional properties. To this end, this study used ultrasound-assisted macroporous resin treatment to extract SMP. The improvement effects and potential mechanisms of ultrasonic-assisted macroporous resin treatment with different powers (100, 300, and 500 W) on the color and functional properties of SMP were studied. The results showed that compared with untreated sunflower meal protein (USMP), the lightness value (L*), solubility, emulsification, and gel elasticity were significantly enhanced when treated with 100 W and 300 W ultrasonic-assisted macroporous resin. However, when the ultrasonic power was increased to 500 W, the L* value, solubility, emulsification, and gel elasticity decreased instead, indicating that lower power (100 W and 300 W) ultrasonic-assisted macroporous resin treatment significantly improved the color and functional properties of SMP. Further research found that ultrasound-assisted macroporous resin treatment changed the secondary and tertiary structures of SMP, transformed ß-sheet into α-helix and ß-turn through rearrangement, and significantly improved surface hydrophobicity. It shows that ultrasonic-assisted macroporous resin treatment expands the SMP structure and exposes hydrophobic groups, thereby improving the color and functional properties of SMP. This study provides a potential strategy for extracting SMP with light color and good functional properties. It also provides a theoretical basis for the wide application of SMP in food processing.

Light controls mesophyll-specific post-transcriptional splicing of photoregulatory genes by AtPRMT5.

Light plays a central role in plant growth and development, providing an energy source and governing various aspects of plant morphology. Previous study showed that many polyadenylated full-length RNA molecules within the nucleus contain unspliced introns (post-transcriptionally spliced introns, PTS introns), which may play a role in rapidly responding to changes in environmental signals. However, the mechanism underlying post-transcriptional regulation during initial light exposure of young, etiolated seedlings remains elusive. In this study, we used FLEP-seq2, a Nanopore-based sequencing technique, to analyze nuclear RNAs in Arabidopsis (Arabidopsis thaliana) seedlings under different light conditions and found numerous light-responsive PTS introns. We also used single-nucleus RNA sequencing (snRNA-seq) to profile transcripts in single nucleus and investigate the distribution of light-responsive PTS introns across distinct cell types. We established that light-induced PTS introns are predominant in mesophyll cells during seedling de-etiolation following exposure of etiolated seedlings to light. We further demonstrated the involvement of the splicing-related factor A. thaliana PROTEIN ARGININE METHYLTRANSFERASE 5 (AtPRMT5), working in concert with the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a critical repressor of light signaling pathways. We showed that these two proteins orchestrate light-induced PTS events in mesophyll cells and facilitate chloroplast development, photosynthesis, and morphogenesis in response to ever-changing light conditions. These findings provide crucial insights into the intricate mechanisms underlying plant acclimation to light at the cell-type level.

A self-healing electrocatalytic system via electrohydrodynamics induced evolution in liquid metal.

Catalytic deterioration during electrocatalytic processes is inevitable for conventional composite electrodes, which are prepared by depositing catalysts onto a rigid current collector. In contrast, metals that are liquid at near room temperature, liquid metals (LMs), are potential electrodes that are uniquely flexible and maneuverable, and whose fluidity may allow them to be more adaptive than rigid substrates. Here we demonstrate a self-healing electrocatalytic system for CO2 electroreduction using bismuth-containing Ga-based LM electrodes. Bi2O3 dispersed in the LM matrix experiences a series of electrohydrodynamic-induced structural changes when exposed to a tunable potential and finally transforms into catalytic bismuth, whose morphology can be controlled by the applied potential. The electrohydrodynamically-induced evolved electrode shows considerable electrocatalytic activity for CO2 reduction to formate. After deterioration of the electrocatalytic performance, the catalyst can be healed via simple mechanical stirring followed by in situ regeneration by applying a reducing potential. With this procedure, the electrode's original structure and catalytic activity are both recovered.

HISTONE DEACETYLASE 9 transduces heat signal in plant cells.

Heat stress limits plant growth, development, and crop yield, but how plant cells precisely sense and transduce heat stress signals remains elusive. Here, we identified a conserved heat stress response mechanism to elucidate how heat stress signal is transmitted from the cytoplasm into the nucleus for epigenetic modifiers. We demonstrate that HISTONE DEACETYLASE 9 (HDA9) transduces heat signals from the cytoplasm to the nucleus to play a positive regulatory role in heat responses in Arabidopsis. Heat specifically induces HDA9 accumulation in the nucleus. Under heat stress, the phosphatase PP2AB'ß directly interacts with and dephosphorylates HDA9 to protect HDA9 from 26S proteasome-mediated degradation, leading to the translocation of nonphosphorylated HDA9 to the nucleus. This heat-induced enrichment of HDA9 in the nucleus depends on the nucleoporin HOS1. In the nucleus, HDA9 binds and deacetylates the target genes related to signaling transduction and plant development to repress gene expression in a transcription factor YIN YANG 1-dependent and -independent manner, resulting in rebalance of plant development and heat response. Therefore, we uncover an HDA9-mediated positive regulatory module in the heat shock signal transduction pathway. More important, this cytoplasm-to-nucleus translocation of HDA9 in response to heat stress is conserved in wheat and rice, which confers the mechanism significant implication potential for crop breeding to cope with global climate warming.

Epigenetic regulation of thermomorphogenesis in Arabidopsis thaliana.

Temperature is a key factor in determining plant growth and development, geographical distribution, and seasonal behavior. Plants accurately sense subtle changes in ambient temperature and alter their growth and development accordingly to improve their chances of survival and successful propagation. Thermomorphogenesis encompasses a variety of morphological changes that help plants acclimate to warm environmental temperatures. Revealing the molecular mechanism of thermomorphogenesis is important for breeding thermo-tolerant crops and ensuring food security under global climate change. Plant adaptation to elevated ambient temperature is regulated by multiple signaling pathways and epigenetic mechanisms such as histone modifications, histone variants, and non-coding RNAs. In this review, we summarize recent advances in the mechanism of epigenetic regulation during thermomorphogenesis with a focus on the model plant Arabidopsis thaliana and briefly discuss future prospects for this field.

NSrp70 suppresses metastasis in triple-negative breast cancer by modulating Numb/TßR1/EMT axis.

Alternative splicing of mRNA precursors allows cancer cells to create different protein isoforms that promote growth and survival. Compared to normal cells, cancer cells frequently exhibit a higher diversity of their transcriptomes. A comprehensive understanding of splicing regulation is required to correct the splicing alterations for the future precision oncology. A quantitative proteomic screen was performed to identify the regulators associated the metastasis in triple-negative breast cancer. Multiple in vitro and in vivo functional analyses were used to study the effects of NSrp70 on breast cancer metastasis. Next, transcriptomic sequencing (RNA-seq) and alternative splicing bioinformatics analysis was applied to screen the potential targets of NSrp70. Moreover, in vitro splicing assays, RNA pull-down, and RNA immunoprecipitation assay were used to confirm the specific binding between NSrp70 and downstream target genes. Furthermore, the prognostic value of NSrp70 was analyzed in a cohort of patients by performing IHC. We uncovered NSrp70 as a novel suppressor of breast cancer metastasis. We discovered that NSrp70 inhibited the skipped exon alternative splicing of NUMB, promoted the degradation of transforming growth factor receptor 1 through lysosome pathway, and regulated TGFß/SMAD-mediated epithelial-mesenchymal transition phenotype in breast cancer cells. Furthermore, high NSrp70 expression correlated with a better prognosis in breast cancer patients. Our findings revealed that splicing regulator NSrp70 serves as a metastasis suppressor.

RNA binding protein POP7 regulates ILF3 mRNA stability and expression to promote breast cancer progression.

RNA binding proteins (RBPs) play pivotal roles in breast cancer (BC) development. As an RBP, Processing of precursor 7 (POP7) is one of the subunits of RNase P and RNase MRP, however, its exact function and mechanism in BC remain unknown. Here, we showed that expression of POP7 was frequently increased in BC cells and in primary breast tumors. Upregulated POP7 significantly promoted BC cell proliferation in vitro and primary tumor growth in vivo. POP7 also increased cell migration, invasion in vitro, and lung metastasis in vivo. Through RNA immunoprecipitation coupled with sequencing (RIP-seq), we found that POP7 bound preferentially to intron regions and POP7-binding peak associated genes were mainly enriched in cancer-related pathways. Furthermore, POP7 regulated Interleukin Enhancer Binding Factor 3 (ILF3) expression through influencing its mRNA stability. Knockdown of ILF3 significantly impaired the increased malignant potential of POP7-overexpressing cells, suggesting that POP7 enhances BC progression through regulating ILF3 expression. Collectively, our findings provide the first evidence for the important role of POP7 and its regulation of ILF3 in promoting BC progression.

Famitinib with Camrelizumab and Nab-Paclitaxel for Advanced Immunomodulatory Triple-Negative Breast Cancer (FUTURE-C-Plus): An Open-Label, Single-Arm, Phase II Trial.

PURPOSE: Camrelizumab, an mAb against programmed cell death protein 1 (PD-1), plus nab-paclitaxel exhibited promising antitumor activity in refractory metastatic immunomodulatory triple-negative breast cancer (TNBC). Famitinib is a tyrosine kinase inhibitor targeting VEGFR2, PDGFR, and c-kit. We aimed to assess the efficacy and safety of a novel combination of famitinib, camrelizumab, and nab-paclitaxel in advanced immunomodulatory TNBC. PATIENTS AND METHODS: This open-label, single-arm, phase II study enrolled patients with previously untreated, advanced, immunomodulatory TNBC (CD8 IHC staining ≥10%). Eligible patients received 20 mg of oral famitinib on days 1 to 28, 200 mg of i.v. camrelizumab on days 1 and 15, and i.v. nab-paclitaxel 100 mg/m2 on days 1, 8, and 15 in 4-week cycles. The primary endpoint was objective response rate (ORR), as assessed by investigators per RECIST v1.1. Key secondary endpoints were progression-free survival (PFS), overall survival (OS), duration of response (DOR), safety, and exploratory biomarkers. RESULTS: Forty-eight patients were enrolled and treated. Median follow-up was 17.0 months (range, 8.7-24.3). Confirmed ORR was 81.3% [95% confidence interval (CI), 70.2-92.3], with five complete and 34 partial responses. Median PFS was 13.6 months (95% CI, 8.4-18.8), and median DOR was 14.9 months [95% CI, not estimable (NE)-NE]. Median OS was not reached. No treatment-related deaths were reported. Among 30 patients with IHC, 13 (43.3%) were programmed death-ligand 1 (PD-L1)-negative, and PD-L1 was associated with favorable response. PKD1 and KAT6A somatic mutations were associated with therapy response. CONCLUSIONS: The triplet regimen was efficacious and well tolerated in previously untreated, advanced, immunomodulatory TNBC. The randomized controlled FUTURE-SUPER trial is under way to validate our findings. See related commentary by Salgado and Loi, p. 2728.

DGKZ promotes TGFß signaling pathway and metastasis in triple-negative breast cancer by suppressing lipid raft-dependent endocytosis of TGFßR2.

Diacylglycerol kinase ζ (DGKZ) is a diacylglycerol kinase that metabolizes diacylglycerol to yield phosphatidic acid, and its function in breast cancer progression remains unclear. In this study, via screening of a CRISPR-Cas9 knockout library containing lipid metabolic genes, DGKZ was identified as a potential prometastatic gene. We first confirmed that high DGKZ expression correlated with tumor progression and poor prognosis in patients. Next, knockout of DGKZ in triple-negative breast cancer cell lines were found to significantly inhibit metastatic behaviors in vitro and in vivo, whereas its overexpression increased the metastatic potential of cell lines. Mechanistic studies based on RNA sequencing and bioinformatic analysis indicated that DGKZ might regulate cell metastasis by promoting epithelial-mesenchymal transition via the transforming growth factor ß (TGFß) signaling pathway. Furthermore, we found that overexpression of DGKZ activated the TGFß/TGFßR2/Smad3 signaling pathway by inhibiting the degradation of TGFßR2 through suppression of caveolin/lipid raft-dependent endocytosis. Moreover, the caveolin/lipid raft-dependent endocytosis of TGFßR2 was regulated by the metabolite phosphatidic acid, which might alter TGFßR2 partitioning in lipid rafts and nonlipid rafts by affecting the fluidity of the plasma membrane. These findings suggested that DGKZ is a novel promoter of metastasis and that it could be a potential prognostic indicator in patients with triple-negative breast cancer.

Conjoint analysis of circulating tumor cells and solid tumors for exploring potential prognostic markers and constructing a robust novel predictive signature for breast cancer.

BACKGROUND: Distance metastasis is the leading cause of death for breast cancer patients, and circulating tumor cells (CTCs) play a key role in cancer metastasis. There have been few studies on CTCs at the molecular level due to their rarity, and the heterogeneity of CTCs may provide special information for solid tumor analysis. METHODS: In this study, we used the gene expression and clinical information of single-cell RNA-seq data of CTCs of breast cancer and discovered a cluster of epithelial cells that had more aggressive characteristics. The differentially expressed genes (DEGs) between the identified epithelial cells cluster and others from single-CTCs were selected for further analysis in bulk sequence data of solid breast cancers. RESULTS: Eighteen genes closely related to the specific CTC epithelial phenotype and breast cancer patient prognosis were identified. Among these 18 genes, we selected the GARS gene, which has not been studied in breast cancer, for functional research and confirmed that it may be a potential oncogene in breast cancer. A risk score was established by the 18 genes, and a high-risk score was strongly associated with a high metastasis rate and poor survival prognosis in breast cancer. The high-risk score group was related to a defective immune infiltration environment in breast cancer, and the immune checkpoint therapy response rate was lower in this group. The drug-sensitive analysis shows that the high-risk score patients may be more sensitive to AKT-mTOR and the cyclin-dependent kinase (CDK) pathways drugs than low-risk score patients. CONCLUSIONS: Our 18-gene risk score shows good prognostic and predictive values and might be a personalized prognostic marker or therapy guide marker in breast cancer patients.

Comprehensive Combined Proteomics and Genomics Analysis Identifies Prognostic Related Transcription Factors in Breast Cancer and Explores the Role of DMAP1 in Breast Cancer.

Transcription factors (TFs) are important for regulating gene transcription and are the hallmark of many cancers. The identification of breast cancer TFs will help in developing new diagnostic and individualized cancer treatment tools. In this study, we used quantitative proteomic analyses of nuclear proteins and massive transcriptome data to identify enriched potential TFs and explore the possible role of the transcription factor DMAP1 in breast cancer. We identified 13 prognostic-related TFs and constructed their regulated genes, alternative splicing (AS) events, and splicing factor (SF) regulation networks. DMAP1 was reported less in breast cancer. The expression of DMAP1 decreased in breast cancer tumors compared with normal tissues. The poor prognosis of patients with low DMAP1 expression may relate to the activated PI3K/Akt signaling pathway, as well as other cancer-relevant pathways. This may be due to the low methylation and high expression of these pathway genes and the fact that such patients show more sensitivity to some PI3K/Akt signaling pathway inhibitors. The high expression of DMAP1 was correlated with low immune cell infiltration, and the response to immune checkpoint inhibitor treatment in patients with high DMAP1 expression was low. Our study identifies some transcription factors that are significant for breast cancer progression, which can be used as potential personalized prognostic markers in the future.

Identification of a Three-RNA Binding Proteins (RBPs) Signature Predicting Prognosis for Breast Cancer.

BACKGROUND: To date, breast cancer remains the primary cause of tumor-related death among women, even though some leap-type developments of oncology have been done to slash the mortality. Considering the tumor heterogeneity and individual variation, the more reliable biomarkers are required to be identified for supporting the development of precision medicine in breast cancer. METHODS: Based on the TCGA-BRCA and METABRIC databases, the differently expressed RNA binding proteins (RBPs) between tumor and normal tissues were investigated. In this study, we focused on the communal differently expressed RBPs in four subtypes of breast cancer. Lasso-penalized Cox analysis, Stepwise-multivariate Cox analysis and Kaplan-Meier survival curve were performed to identify the hub RBP-coding genes in predicting prognosis of breast cancer, and a prognostic model was established. The efficiency of this model was further validated in other independent GSE20685, GSE4922 and FUSCC-TNBC cohorts by calculating the risk score and performing survival analysis, ROC and nomogram. Moreover, pathologic functions of the candidate RBPs in breast cancer were explored using some routine experiments in vitro, and the potential compounds targeting these RBPs were predicted by reviewing the Comparative Toxicogenomics Database. RESULTS: Here, we identified 62 RBPs which were differently expressed between the tumor and normal tissues. Thereinto, three RBPs (MRPL12, MRPL13 and POP1) acted as independent risk factors, and their expression pattern also correlated with poor prognosis of patients. A prognostic model, built with these 3-RBPs, possessed statistical significance to predict the survival probability of patients with breast cancer. Furthermore, experimental validations showed that down-regulating the expression of endogenous MRPL12, MRPL13 or POP1 could dramatically suppress the cellular viability and migration of breast cancer cells in vitro. Besides, some compounds (such as the Acetaminophen, Urethane and Tunicamycin) were predicted for curing breast cancer via targeting MRPL12, MRPL13 and POP1 simultaneously. CONCLUSION: This study identified and established a 3-RBPs-based signature and nomogram for predicting the survival probability of patients with breast cancer. MRPL12, MRPL13 and POP1 might act as oncogenes in maintaining cellular viability and accelerating metastasis of breast cancer cells, implying the possibility of which to be designed as biomarkers and/or therapeutic targets for breast cancer.

A pharmacophore-based classification better predicts the outcomes of HER2-negative breast cancer patients receiving the anthracycline- and/or taxane-based neoadjuvant chemotherapy.

AIMS: Prognosis of patients for human epidermal growth factor receptor 2 (HER2)-negative breast cancer post neoadjuvant chemotherapy is not well understood. The aim of this study was to develop a novel pharmacophore-based signature to better classify and predict the risk of HER2-negative patients after anthracycline-and/or taxane-based neoadjuvant chemotherapy (NACT). MAIN METHODS: Anthracycline and taxane pharmacophore-based genes were obtained from PharmMapper. Drug-targeted genes (DTG) related clinical and bioinformatic analyses were undertaken in four GEO datasets. KEY FINDINGS: We used 12 genes from the pharmacophore to develop a DTG score (DTG-S). The DTG-S classification exhibited significant prognostic ability with respect to disease free survival (DFS) for HER2-negative patients who receive at least one type of neoadjuvant chemotherapy that included anthracycline and/or taxane. DTG-S associated with a high predictive ability for pathological complete response (pCR) as well as for prognosis of breast cancer. Using the DTG-S classification in other prediction models may improve the reclassification accuracy for DFS. Combining the DTG-S with other clinicopathological factors may further improve its predictive ability of patients' outcomes. Gene ontology and KEGG pathway analysis showed that the biological processes of DTG-S high group were associated with the cell cycle, cell migration, and cell signal transduction pathways. Targeted drug analysis shows that some CDK inhibitors and PI3K-AKT pathway inhibitors may be useful for high DTG-S patients. SIGNIFICANCE: The DTG-S classification adds prognostic and predictive information to classical parameters for HER2-negative patients who receive anthracycline-and/or taxane-based NACT, which could improve the patients' risk stratification and may help guide adjuvant treatment.

NSDHL promotes triple-negative breast cancer metastasis through the TGFß signaling pathway and cholesterol biosynthesis.

PURPOSE: Metastasis is the main cause of breast cancer mortality. Recent studies have proved that lipid metabolic reprogramming plays critical roles in breast cancer carcinogenesis and metastasis. We aim to identify critical lipid metabolism genes in breast cancer metastasis. METHODS: We designed and cloned a CRISPR pooled library containing lipid metabolic gene guide RNAs and performed a genetic screen in vivo. Transwell assay and animal experiments were used to evaluate cell metastatic ability in vitro or in vivo, respectively. We performed immunohistochemistry with breast cancer tissue microarray to study the clinical significance of NSDHL. FINDINGS: We identified a cholesterol metabolic enzyme, NSDHL, as a potential metastatic driver in triple-negative breast cancer. NSDHL was highly expressed in breast cancer tissues and predicted a poor prognosis. NSDHL knockdown significantly suppressed cell proliferation and migration. Mechanistically, NSDHL activated the TGFß signaling pathway by inhibiting the endosomal degradation of TGFßR2. In addition, blocking the upstream metabolism of NSDHL with ketoconazole rescued cancer metastasis and TGFßR2 degradation. However, the inactivation of NSDHL (Y151X) did not rescue the migration ability and the TGFßR2 protein expression. CONCLUSION: Taken together, our findings established that NSDHL serves as a metastatic driver, and its function depends on its enzyme activity in cholesterol biosynthesis and is mediated by the NSDHL-TGFßR2 signal pathway. Our study indicated that NSDHL and steroid biosynthesis may serve as new drug targets for patients with advanced breast cancer.

DEAD-BOX RNA HELICASE 27 regulates microRNA biogenesis, zygote division, and stem cell homeostasis.

After double fertilization, zygotic embryogenesis initiates a new life cycle, and stem cell homeostasis in the shoot apical meristem (SAM) and root apical meristem (RAM) allows plants to produce new tissues and organs continuously. Here, we report that mutations in DEAD-BOX RNA HELICASE 27 (RH27) affect zygote division and stem cell homeostasis in Arabidopsis (Arabidopsis thaliana). The strong mutant allele rh27-1 caused a zygote-lethal phenotype, while the weak mutant allele rh27-2 led to minor defects in embryogenesis and severely compromised stem cell homeostasis in the SAM and RAM. RH27 is expressed in embryos from the zygote stage, and in both the SAM and RAM, and RH27 is a nucleus-localized protein. The expression levels of genes related to stem cell homeostasis were elevated in rh27-2 plants, alongside down-regulation of their regulatory microRNAs (miRNAs). Further analyses of rh27-2 plants revealed reduced levels of a large subset of miRNAs and their pri-miRNAs in shoot apices and root tips. In addition, biochemical studies showed that RH27 associates with pri-miRNAs and interacts with miRNA-biogenesis components, including DAWDLE, HYPONASTIC LEAVES 1, and SERRATE. Therefore, we propose that RH27 is a component of the microprocessor complex and is critical for zygote division and stem cell homeostasis.

Metformin induces ferroptosis by targeting miR-324-3p/GPX4 axis in breast cancer.

Metformin is a widely prescribed hypoglycemic drug. Many studies have shown its anti-cancer properties. In the present study, we aimed to explore the effect of metformin on breast cancer and clarify the underlying mechanism. Our results showed that metformin induced ferroptosis in MDA-MB-231 cells through upregulating miR-324-3p expression. Overexpression of miR-324-3p inhibited cancer cell viability. miR-324-3p inhibitor promoted cell viability. Further studies showed that the effect of miR-324-3p was mediated by directly targeting glutathione peroxidase 4 (GPX4). miR-324-3p bound to the 3'-UTR of GPX4 and led to the downregulation of GPX4. In vivo studies showed that metformin induced ferroptosis by upregulating miR-324-3p in the xenograft model of breast cancer in mice. Our study suggested that metformin promotes ferroptosis of breast cancer by targeting the miR-324-3p/GPX4 axis. Metformin could act as a potential anti-cancer agent through the induction of ferroptosis.

The clinicopathological and MRI features of patients with BRCA1/2 mutations in familial breast cancer.

BACKGROUND: To determine the histopathological and MRI features of BRCA1/2 mutation-associated familial breast cancers compared with those of BRCA1/2 mutation-negative and sporadic breast cancers and to further compare the imaging features of cancers from BRCA1 and BRCA2 mutation carriers according to lesion type on MRI. METHODS: A retrospective review of medical records was conducted to determine tumour clinicopathologic features and MRI characteristics between June 2011 and July 2017, and 93 lesions with BRCA mutations, 93 lesions without BRCA mutations from familial breast cancers and 93 lesions from sporadic breast cancers were included. Histopathologic data, including immunohistochemistry findings and MRI data according to the BI-RADS lexicon, were reviewed. The association between MRI or histopathologic findings and BRCA mutations was analysed. RESULTS: BRCA-positive familial breast cancers had a higher number of IDCs with high nuclear grade and lymph node metastasis (all P<0.05), while the BRCA-negative group had a significantly lower Ki-67 index (P<0.001). BPE on MRI was found to be significantly lower for BRCA mutations of familial breast cancer (P=0.024). BRCA1 carriers tended to exhibit the triple-negative phenotype with a more benign shape and margin (P=0.006 and 0.019), whereas BRCA2 mutations were associated with the luminal phenotype and more malignant features. CONCLUSIONS: BRCA mutation carriers had a significantly higher number of IDCs with more aggressive cancer, and BRCA-negative cancers had low proliferation levels. Background features on MRI may help to identify BRCA status, while tumour characteristics can differentiate the BRCA1/2 mutation status, consistent with the differences in their clinicopathologic features.

CPSF30-L-mediated recognition of mRNA m6A modification controls alternative polyadenylation of nitrate signaling-related gene transcripts in Arabidopsis.

N6-methyladenosine (m6A), a ubiquitous internal modification of eukaryotic mRNAs, plays a vital role in almost every aspect of mRNA metabolism. However, there is little evidence documenting the role of m6A in regulating alternative polyadenylation (APA) in plants. APA is controlled by a large protein-RNA complex with many components, including CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR30 (CPSF30). In Arabidopsis, CPSF30 has two isoforms and the longer isoform (CPSF30-L) contains a YT512-B Homology (YTH) domain, which is unique to plants. In this study, we showed that CPSF30-L YTH domain binds to m6A in vitro. In the cpsf30-2 mutant, the transcripts of many genes including several important nitrate signaling-related genes had shifts in polyadenylation sites that were correlated with m6A peaks, indicating that these gene transcripts carrying m6A tend to be regulated by APA. Wild-type CPSF30-L could rescue the defects in APA and nitrate metabolism in cpsf30-2, but m6A-binding-defective mutants of CPSF30-L could not. Taken together, our results demonstrated that m6A modification regulates APA in Arabidopsis and revealed that the m6A reader CPSF30-L affects nitrate signaling by controlling APA, shedding new light on the roles of the m6A modification during RNA 3'-end processing in nitrate metabolism.