RESUMO
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.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteína-Arginina N-Metiltransferases , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Plântula/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , LuzRESUMO
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.
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Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Células Vegetais/metabolismo , Melhoramento Vegetal , Arabidopsis/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismoRESUMO
BACKGROUND: Empirical chemotherapy remains the standard of care in patients with unfavourable cancer of unknown primary (CUP). Gene-expression profiling assays have been developed to identify the tissue of origin in patients with CUP; however, their clinical benefit has not yet been demonstrated. We aimed to evaluate the efficacy and safety of site-specific therapy directed by a 90-gene expression assay compared with empirical chemotherapy in patients with CUP. METHODS: This randomised controlled trial was conducted at Fudan University Shanghai Cancer Center (Shanghai, China). We enrolled patients aged 18-75 years, with previously untreated CUP (histologically confirmed metastatic adenocarcinoma, squamous cell carcinoma, poorly differentiated carcinoma, or poorly differentiated neoplasms) and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, who were not amenable to local radical treatment. Patients were randomly assigned (1:1) by the Pocock and Simon minimisation method to receive either site-specific therapy or empirical chemotherapy (taxane [175 mg/m2 by intravenous infusion on day 1] plus platinum [cisplatin 75 mg/m2 or carboplatin area under the curve 5 by intravenous infusion on day 1], or gemcitabine [1000 mg/m2 by intravenous infusion on days 1 and 8] plus platinum [same as above]). The minimisation factors were ECOG performance status and the extent of the disease. Clinicians and patients were not masked to interventions. The tumour origin in the site-specific therapy group was predicted by the 90-gene expression assay and treatments were administered accordingly. The primary endpoint was progression-free survival in the intention-to-treat population. The trial has been completed and the analysis is final. This study is registered with ClinicalTrials.gov (NCT03278600). FINDINGS: Between Sept 18, 2017, and March 18, 2021, 182 patients (105 [58%] male, 77 [42%] female) were randomly assigned to receive site-specific therapy (n=91) or empirical chemotherapy (n=91). The five most commonly predicted tissues of origin in the site-specific therapy group were gastro-oesophagus (14 [15%]), lung (12 [13%]), ovary (11 [12%]), cervix (11 [12%]), and breast (nine [10%]). At the data cutoff date (April 30, 2023), median follow-up was 33·3 months (IQR 30·4-51·0) for the site-specific therapy group and 30·9 months (27·6-35·5) for the empirical chemotherapy group. Median progression-free survival was significantly longer with site-specific therapy than with empirical chemotherapy (9·6 months [95% CI 8·4-11·9] vs 6·6 months [5·5-7·9]; unadjusted hazard ratio 0·68 [95% CI 0·49-0·93]; p=0·017). Among the 167 patients who started planned treatment, 46 (56%) of 82 patients in the site-specific therapy group and 52 (61%) of 85 patients in the empirical chemotherapy group had grade 3 or worse treatment-related adverse events; the most frequent of these in the site-specific therapy and empirical chemotherapy groups were decreased neutrophil count (36 [44%] vs 42 [49%]), decreased white blood cell count (17 [21%] vs 26 [31%]), and anaemia (ten [12%] vs nine [11%]). Treatment-related serious adverse events were reported in five (6%) patients in the site-specific therapy group and two (2%) in the empirical chemotherapy group. No treatment-related deaths were observed. INTERPRETATION: This single-centre randomised trial showed that site-specific therapy guided by the 90-gene expression assay could improve progression-free survival compared with empirical chemotherapy among patients with previously untreated CUP. Site-specific prediction by the 90-gene expression assay might provide more disease information and expand the therapeutic armamentarium in these patients. FUNDING: Clinical Research Plan of Shanghai Hospital Development Center, Program for Shanghai Outstanding Academic Leader, and Shanghai Anticancer Association SOAR PROJECT. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Primárias Desconhecidas , Humanos , Pessoa de Meia-Idade , Masculino , Feminino , Neoplasias Primárias Desconhecidas/tratamento farmacológico , Neoplasias Primárias Desconhecidas/genética , Neoplasias Primárias Desconhecidas/patologia , Neoplasias Primárias Desconhecidas/mortalidade , Idoso , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Gencitabina , Perfilação da Expressão Gênica , Desoxicitidina/análogos & derivados , Desoxicitidina/administração & dosagem , Desoxicitidina/uso terapêutico , Cisplatino/administração & dosagem , Cisplatino/uso terapêutico , Carboplatina/administração & dosagem , China , Taxoides/administração & dosagem , Taxoides/uso terapêutico , Adulto Jovem , AdolescenteRESUMO
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.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , MicroRNAs/metabolismo , Zigoto/metabolismoRESUMO
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.
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Biomarcadores , Micropartículas Derivadas de Células , Retinopatia Diabética , Humanos , Retinopatia Diabética/terapia , Micropartículas Derivadas de Células/metabolismo , Biomarcadores/metabolismo , Progressão da Doença , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
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.
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Neoplasias da Mama , Neoplasias Pulmonares , Proteínas do Fator Nuclear 90 , Ribonuclease P , Feminino , Humanos , Neoplasias da Mama/genética , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Proteínas do Fator Nuclear 90/genética , Estabilidade de RNA/genética , Autoantígenos/genética , Ribonuclease P/genéticaRESUMO
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.
Assuntos
3-Hidroxiesteroide Desidrogenases , Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , 3-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Colesterol , Feminino , Humanos , Metástase Neoplásica , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Neoplasias de Mama Triplo Negativas/genéticaRESUMO
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.
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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.
Assuntos
Ferroptose/efeitos dos fármacos , Metformina/farmacologia , MicroRNAs/metabolismo , Proteínas de Neoplasias/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , RNA Neoplásico/metabolismo , Feminino , Humanos , Células MCF-7 , MicroRNAs/genética , Proteínas de Neoplasias/genética , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , RNA Neoplásico/genéticaRESUMO
Polyadenylation influences gene expression by affecting mRNA stability, transport, and translatability. Here, we report that Cleavage stimulation Factor 77 (AtCstF77), a component of the pre-mRNA 3'-end polyadenylation machinery, affects polyadenylation site (PAS) selection in transcripts of some auxin signaling genes in Arabidopsis (Arabidopsis thaliana). Disruption of AtCstF77 reduced auxin sensitivity and decreased the expression of the auxin reporter DR5-GFP Null mutations of cstf77 caused severe developmental defects, but were not lethal as previously reported. cstf77-2 genetically interacted with transport inhibitor response 1 auxin signaling f-box 2 auxin receptor double mutants, further supporting that polyadenylation affects auxin signaling. AtCstF77 was ubiquitously expressed in embryos, seedlings, and adult plants. The AtCstF77 protein was localized in the nucleus, which is consistent with its function in pre-mRNA processing. We observed that PASs in transcripts from approximately 2,400 genes were shifted in the cstf77-2 mutant. Moreover, most of the PAS shifts were from proximal to distal sites. Auxin treatment also caused PAS shifts in transcripts from a small number of genes. Several auxin signaling or homeostasis genes had different PASs in their transcripts in the cstf77-2 mutant. The expression levels of AUXIN RESISTANT 2/INDOLE-3-ACETIC ACID 7 were significantly increased in the cstf77-2 mutant, which can partially account for the auxin resistance phenotype of this mutant. Our results demonstrate that AtCstF77 plays pleiotropic and critical roles in Arabidopsis development. Moreover, disruption of AtCstF64, another component of the polyadenylation machinery, led to developmental defects and reduced auxin response, similar to those of the cstf77-2 mutant. We conclude that AtCstF77 affects auxin responses, likely by controlling PAS selection of transcripts of some auxin signaling components.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Fator Estimulador de Clivagem/metabolismo , Ácidos Indolacéticos/metabolismo , Poliadenilação/fisiologia , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/genética , Benzamidas/farmacologia , Sistemas CRISPR-Cas , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Fator Estimulador de Clivagem/genética , Regulação da Expressão Gênica de Plantas , Mutação , Naftóis/farmacologia , Plantas Geneticamente Modificadas , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Sentinel lymph node is the first stop of lymphatic spreading of cancer with known primary. The lymph node metastasis pattern of cancer of unknown primary (CUP) is unclear and has been presumed to follow the same pathway. To test this hypothesis, data of all 716 patients clinically diagnosed as CUP in our center were collected. METHODS: Diagnoses of lymph node metastasis were established by 18F-FDG PET-CT and/or biopsy pathology. Three hundred and forty-seven cases meeting the criteria were divided into three groups: pathology-confirmed primary with invasive biopsy or surgery of the suspicious lesion (group A, n = 64), primary still unknown even with invasive biopsy or surgery of the suspicious lesion (group B, n = 204), and others with no suspicious lesion or lesions who had not been sampled due to medical or other reasons (group C, n = 79). We assessed the clinicopathological features between these groups, and the relationship between lymph node metastasis pattern and confirmed primary site. RESULTS: In group A, the primary sites of 61 cases were compatible with sentinel node theory, resulting in a positive predictive value of 95%. No significant differences in age, sex, bone metastasis, or visceral metastasis observed between group A and group B, except that group A had a higher ratio of differentiated carcinoma (94% vs. 77%, P = 0.003). CONCLUSION: To our knowledge, this is the first evidence indicating that the majority of clinical CUP cases follow the sentinel node theory to spread in lymph nodes, which helps tracking the primary, especially for differentiated carcinoma.
Assuntos
Neoplasias Primárias Desconhecidas/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos/metabolismo , Biópsia de Linfonodo Sentinela/métodos , Linfonodo Sentinela/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18/metabolismo , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Primárias Desconhecidas/diagnóstico por imagem , Neoplasias Primárias Desconhecidas/cirurgia , Prognóstico , Linfonodo Sentinela/diagnóstico por imagem , Linfonodo Sentinela/cirurgia , Adulto JovemRESUMO
BACKGROUND: The current randomized, controlled, multicenter clinical trial was conducted to investigate the efficacy of concurrent neoadjuvant chemotherapy (NCT) and estrogen deprivation in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. METHODS: Eligible patients with AJCC stage IIB to stage IIIC, ER-positive, HER2-negative breast cancer were enrolled and randomly assigned to receive NCT with or without estrogen deprivation. The primary endpoint was the objective response rate (ORR). RESULTS: A total of 249 patients were assigned to either neoadjuvant chemoendocrine therapy (NCET) (125 patients) or the NCT group (124 patients). In the intention-to-treat analysis, the ORR was found to be significantly higher in the NCET group compared with the NCT group (84.8% vs 72.6%; odds ratio, 2.11 [95% CI, 1.13-3.95; P = .02). The efficacy of NCET was more prominent in tumors with a higher Ki-67 index (>20%), with an ORR of 91.2% reported in the NCET group versus 68.7% in the NCT group (P = .001). The pathologic complete response and pathological response rates did not differ significantly between the 2 groups. Although there was no significant difference with regard to progression-free survival (PFS) between the 2 groups (P = .188), patients with a higher baseline Ki-67 index appeared to derive a greater PFS benefit from NCET (2-year PFS rate of 91.5% in the NCET group vs 76.5% in the NCT group; P = .058). Adding endocrine agents to NCT did not result in significant differences in adverse events (grade 3 or 4; graded according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) between the 2 groups. CONCLUSIONS: The addition of estrogen deprivation to NCT appears to improve the clinical response in patients with ER-positive, HER2-negative breast cancer, especially for those individuals with a higher Ki-67 index. Patients with a higher Ki-67 index might derive more PFS benefit from concurrent neoadjuvant treatment.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/mortalidade , Estrogênios/metabolismo , Terapia Neoadjuvante/mortalidade , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Adulto JovemRESUMO
Angiosperms integrate a multitude of endogenous and environmental signals to control floral development, thereby ensuring reproductive success. Here, we report the identification of AGAMOUS AND TERMINAL FLOWER (AGTFL), a novel regulator of floral development in Medicago truncatula. Mutation of AGTFL led to the transformation of carpels and stamens into numerous sepals and petals and altered primary inflorescence identity. AGTFL encodes a nucleus-localized protein containing a putative Myb/SANT-like DNA-binding domain and a PKc kinase domain. Molecular and genetic analyses revealed that AGTFL regulates the transcription of MtAGs and MtTFL1 to control floral organ identity and inflorescence development.
Assuntos
Flores/fisiologia , Inflorescência/fisiologia , Medicago truncatula/fisiologia , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Inflorescência/genética , Inflorescência/metabolismo , Medicago truncatula/genética , Mutação/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
After the publication of this work [1] an error in Fig. 1c was brought to our attention: the Western blots for PRDX6 and ß-actin were similar to those shown in lanes 5-6 of Fig. 4g. To verify these findings, we have repeated this experiment and the results are shown in a new Fig. 1c below. The repeated experimental results are consistent with the previously reported findings in the original study [1] and the functional role for PRDX6 in malignant progression of human cancer including breast cancer has been widely documented and recognized in numerous other studies [2]. We apologize for the error. However, this correction does not affect the conclusions of the article.
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OBJECTIVE: To evaluate the role of germline mutations of TP53 gene among a Chinese population with high risk for breast cancer. METHODS: A total of 81 BRCA-negative breast cancer probands from cancer families were analyzed using targeted capture and next-generation sequencing. Candidate mutations were verified with Sanger sequencing. Co-segregation analyses were carried out to explore the likely pathogenicity of the mutation. RESULTS: Of the 81 BRCA-negative patients, 3 exonic mutations in the TP53 gene were identified in 3 breast cancer patients. Of these, 2 mutations were previously reported and 1 was novel. One family with TP53 mutation has met the criteria for Li-Fraumeni syndrome (LFS) and accounted for 9.1% of all families who fulfilled the diagnostic criteria for LFS. Two of the carriers were diagnosed with breast cancer under the age of 30, and have accounted for 11.8% (2/17) of all very young (≤30 years) breast cancer patients in our study. CONCLUSION: The TP53 germline mutation is more common in Chinese population with a high risk for breast cancer than previously thought. TP53 gene mutation screening should be considered particularly for patients with a family history of LFS and very young age of onset.
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Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Mutação em Linhagem Germinativa , Proteína Supressora de Tumor p53/genética , Adulto , Povo Asiático/genética , Sequência de Bases , Neoplasias da Mama/etnologia , China , Análise Mutacional de DNA , Éxons , Saúde da Família , Feminino , Predisposição Genética para Doença/etnologia , Heterozigoto , Humanos , Síndrome de Li-Fraumeni/etnologia , Síndrome de Li-Fraumeni/genética , Masculino , Pessoa de Meia-Idade , Linhagem , Fatores de Risco , Adulto JovemRESUMO
BACKGROUND: PA-MSHA, a genetically engineered Pseudomonas aeruginosa (PA) strain, is currently under investigation as a new anti-cancer drug. It can induce cell cycle arrest and apoptosis in different human cancer cells, including hormone receptor negative breast cancer cells. However, the underlying mechanism of tumor lethality mediated by PA-MSHA remains to be fully investigated. METHODS: The effect of PA-MSHA on human hormone receptor negative breast cancer cells was analyzed by morphological measurement, western blot, cell proliferation assay and mouse xenograft model. RESULTS: PA-MSHA was found to induce endoplasmic reticulum (ER) stress in breast cancer cell lines through the IRE1 signaling pathway. Inhibiting autophagy potentiated the cytotoxic effect of PA-MSHA while treating breast cancer cell lines. In mouse xenograft model, PA-MSHA produced more pronounced tumor suppression in mice inoculated with IRE1 gene knockdown. MDA-MB-231HM cells. CONCLUSIONS: These findings demonstrated inhibiting autophagy together with PA-MSHA might be a promising therapeutic strategy in treating hormone receptor negative breast cancer cells.
Assuntos
Autofagia/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hemaglutininas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Endorribonucleases/genética , Feminino , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Proteínas Serina-Treonina Quinases/genética , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
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.
Assuntos
Helianthus , Proteínas de Plantas/química , Solubilidade , Interações Hidrofóbicas e Hidrofílicas , Extratos Vegetais/químicaRESUMO
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.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias de Mama Triplo Negativas , Animais , Humanos , Camundongos , Mama , Linfócitos T CD8-Positivos , Quimiocina CCL2 , Modelos Animais de Doenças , Imunoterapia , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/imunologia , Microambiente Tumoral , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismoRESUMO
PURPOSE: Proteasome inhibition induces endoplasmic reticulum (ER) stress and compensatory autophagy to relieve ER stress. Disturbance of intracellular calcium homeostasis can lead to ER stress and alter the autophagy process. It has been suggested that inhibition of the proteasome disrupts intracellular calcium homeostasis. However, it is unknown if intracellular calcium affects proteasome inhibitor-induced ER stress and autophagy. METHODS: Human colon cancer HCT116 Bax positive and negative cell lines were treated with MG132, a proteasome inhibitor. BAPTA-AM, a cell permeable free calcium chelator, was used to modulate intracellular calcium levels. Autophagy and cell death were determined by fluorescence microscopy and immunoblot analysis. RESULTS: MG132 increased intracellular calcium levels in HCT116 cells, which was suppressed by BAPTA-AM. MG132 suppressed proteasome activity independent of Bax and intracellular calcium levels in HCT116 cells. BAPTA-AM inhibited MG132-induced cellular vacuolization and ER stress, but not apoptosis. MG132 induced autophagy with normal autophagosome-lysosome fusion. BAPTA-AM seemed not to affect autophagosome-lysosome fusion in MG132-treated cells but further enhanced MG132-induced LC3-II levels and GFP-LC3 puncta formation, which was likely via impaired lysosome function. CONCLUSIONS: Blocking intracellular calcium by BAPTA-AM relieved MG132-induced ER stress, but it was unable to rescue MG132-induced apoptosis, which was likely due to impaired autophagic degradation.
Assuntos
Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Leupeptinas/farmacologia , Inibidores de Proteassoma/farmacologia , Autofagia/efeitos dos fármacos , Quelantes/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Células HCT116 , HumanosRESUMO
The Atg4 cysteine proteases are required for processing Atg8 for the latter to be conjugated to phosphatidylethanolamine on autophagosomal membranes, a key step in autophagosome biogenesis. Notably, whereas there are only one atg4 and one atg8 gene in the yeast, the mammals have four Atg4 homologues and six Atg8 homologues. The Atg8 homologues seem to play different roles in autophagosome biogenesis, and previous studies had indicated that they could be differentially processed by Atg4 homologues. The present study provided the first detailed kinetics analysis of all four Atg4 homologues against four representative Atg8 homologues. The data indicated that Atg4B possessed the broadest spectrum against all substrates, followed by Atg4A, whereas Atg4C and Atg4D had minimal activities as did the catalytic mutant of Atg4B (C74S). On the other hand, GATE-16 seemed to be the overall best substrate for Atg4 proteases. The kinetics parameters of Atg4B were also affected by its structure and that of the substrates, indicating a process of induced fit. The determination of the kinetics parameters of the various Atg4-Atg8 pairs provides a base for the understanding of the potential selective impact of the reaction on autophagosome biogenesis.