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1.
Proc Natl Acad Sci U S A ; 121(28): e2322972121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38968116

RESUMO

Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.


Assuntos
Reparo do DNA , Ubiquitina-Proteína Ligases , Humanos , Quebras de DNA de Cadeia Dupla , Histonas/metabolismo , Histonas/genética , Poliubiquitina/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
2.
Nucleic Acids Res ; 51(18): 9733-9747, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37638744

RESUMO

RAP80 has been characterized as a component of the BRCA1-A complex and is responsible for the recruitment of BRCA1 to DNA double-strand breaks (DSBs). However, we and others found that the recruitment of RAP80 and BRCA1 were not absolutely temporally synchronized, indicating that other mechanisms, apart from physical interaction, might be implicated. Recently, liquid-liquid phase separation (LLPS) has been characterized as a novel mechanism for the organization of key signaling molecules to drive their particular cellular functions. Here, we characterized that RAP80 LLPS at DSB was required for RAP80-mediated BRCA1 recruitment. Both cellular and in vitro experiments showed that RAP80 phase separated at DSB, which was ascribed to a highly disordered region (IDR) at its N-terminal. Meanwhile, the Lys63-linked poly-ubiquitin chains that quickly formed after DSBs occur, strongly enhanced RAP80 phase separation and were responsible for the induction of RAP80 condensation at the DSB site. Most importantly, abolishing the condensation of RAP80 significantly suppressed the formation of BRCA1 foci, encovering a pivotal role of RAP80 condensates in BRCA1 recruitment and radiosensitivity. Together, our study disclosed a new mechanism underlying RAP80-mediated BRCA1 recruitment, which provided new insight into the role of phase separation in DSB repair.

3.
BMC Cancer ; 23(1): 467, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37217903

RESUMO

BACKGROUND: Neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision are standard treatment regimen for patients with locally advanced rectal cancer (LARC). This sphincter-saving treatment strategy may be accompanied by a series of anorectal functional disorders. Yet, prospective studies that dynamically evaluating the respective roles of radiotherapy, chemotherapy and surgery on anorectal function are lacking. PATIENTS/DESIGN: The study is a prospective, observational, controlled, multicentre study. After screening for eligibility and obtaining informed consent, a total of 402 LARC patients undergoing NCRT followed by surgery, or neoadjuvant chemotherapy followed by surgery, or surgery only would be included in the trial. The primary outcome measure is the average resting pressure of anal sphincter. The secondary outcome measures are maximum anal sphincter contraction pressure, Wexner continence score and low anterior resection syndrome (LARS) score. Evaluations will be carried out at the following stages: baseline (T1), after radiotherapy or chemotherapy (before surgery, T2), after surgery (before closing the temporary stoma, T3), and at follow-up visits (every 3 to 6 months, T4, T5……). Follow-up for each patient will be at least 2 years. DISCUSSION: We expect the program to provide more information of neoadjuvant radiotherapy and/or chemotherapy on anorectal function, and to optimize the treatment strategy to reduce anorectal dysfunction for LARC patients. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05671809). Registered on 26 December 2022.


Assuntos
Terapia Neoadjuvante , Neoplasias Retais , Humanos , Terapia Neoadjuvante/métodos , Neoplasias Retais/patologia , Estudos Prospectivos , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Quimiorradioterapia/métodos , Estadiamento de Neoplasias , Estudos Observacionais como Assunto , Estudos Multicêntricos como Assunto
4.
Chem Biodivers ; 20(10): e202300620, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37690995

RESUMO

Five psoralen derivatives were synthesized and the structures of them were characterized by 1 H-NMR, 13 C-NMR, and IR. The antioxidant properties of the compounds were tested by inhibiting the free radical-initiated DNA oxidation and scavenging the radical reaction. The results showed that the effective stoichiometric factors (n) of the compounds V and IV could reach 2.00 and 2.11 in the system of inhibiting the DNA oxidation reaction initiated by 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). In the inhibition of ⋅OH-oxidation of the DNA system, compounds I~V showed antioxidant properties. The thiobarbituric acid absorbance (TBARS) percentages of compounds IV and V were 76.19 % and 78.84 %. Compounds I~V could also inhibit Cu2+ /GSH-oxidation of DNA, and all compounds exhibited good antioxidant properties except compound II (94.00 %). All the five compounds were able to trap diammonium 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) salt radical (ABTS+ ⋅), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH⋅) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-p-tolylox radical (galvinoxyl⋅). The ability of compounds I~V to scavenge those free radicals can be measured by the k values. The k values ranged from 0.07 to 0.82 in scavenging ABTS+ ⋅, galvinoxyl, and DPPH radicals, respectively.

5.
BMC Cancer ; 22(1): 1140, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335306

RESUMO

BACKGROUND: Our previous study reported that recombinant human epidermal growth factor (rhEGF)-triggered EGFR internalization promoted radioresistance. Here, we aimed to evaluate the effect of rhEGF on the skin protection of rectal and anal cancer patients receiving radiotherapy. METHODS: One hundred and ninety-three rectal and anal cancer patients who received radiotherapy were prospectively enrolled from January 2019 to December 2020. To perform self-controlled study, the left and right pelvic skin area (separated by midline) were randomly assigned to the rhEGF and control side. The association between radiation dermatitis and factors including rhEGF, the dose of radiotherapy and tumor distance from anal edge were analyzed. RESULTS: Among 193 enrolled patients, 41 patients (21.2%) did not develop radiation dermatitis, and 152 patients (78.8%) suffered radiation dermatitis on at least one side of pelvic skin at the end of radiotherapy. For the effect on radiation dermatitis grade, rhEGF had improved effect on 6 (4.0%) patients, detrimental effect on 2 (1.3%) patients, and no effect on 144 (94.7%) patients. Whereas for the effect on radiation dermatitis area, rhEGF showed improved effect on the radiation dermatitis area of 46 (30.2%) patients, detrimental effect on 15 (9.9%) patients, and no effect on 91 (59.9%) patients. The radiation dermatitis area of rhEGF side was significantly smaller than that of control side (P = 0.0007). CONCLUSIONS: rhEGF is a skin protective reagent for rectal and anal cancer patients receiving radiotherapy. TRIAL REGISTRATION: Chinese Clinical Trial Registry identifier: ChiCTR1900020842; Date of registration: 20/01/2019.


Assuntos
Neoplasias do Ânus , Radiodermite , Humanos , Neoplasias do Ânus/tratamento farmacológico , Neoplasias do Ânus/radioterapia , Fator de Crescimento Epidérmico/uso terapêutico , Radiodermite/tratamento farmacológico , Radiodermite/etiologia , Projetos de Pesquisa
6.
Med Sci Monit ; 27: e931427, 2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34366426

RESUMO

BACKGROUND Acute chemical liver injury needs to be further explored. The present study aimed to compare the effects of intraperitoneal injection with carbon tetrachloride on acute liver toxicity after 24 h in male and female Kunming mice. MATERIAL AND METHODS In this study, female and male mice were simultaneously divided into 3 different groups. Each group was treated differently, and after 24 h, blood samples were collected to check for changes in the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which were used to assess liver toxicity. Liver samples were used for hematoxylin-eosin staining, and periodic acid Schiff reagent staining was performed to detect the pathological changes of each group. The expression level of biomarker molecules in liver cells was also systematically analyzed. RESULTS Our results showed that, compared with male mice, female mice showed more serious damage: reduced glycogen and higher degree of necrosis, and the levels of heatshock protein 27 (HSP27), heat-shock protein 70 (HSP70), proliferating cell nuclear antigen (PCNA) and B cell lymphoma/lewkmia-2 (Bcl-2) were significantly lower than in the male group (P<0.05 or P<0.01), while the results of Bcl-2-associated X protein (Bax), cysteinyl aspartate specific proteinase 3 (Caspase3), and cytochrome P450 2E1 (CYP2E1) were the opposite (P<0.05 or P<0.01). CONCLUSIONS The findings from this study showed that, compared with male mice, at 24 h after CCl4 toxicity, female mice showed more severe changes of hepatocyte necrosis and PAS-positivity, with significantly reduced expression of HSP27, HSP70, PCNA, and Bcl-2, and significantly increased expression of Bax, caspase-3, and CYP2E1.


Assuntos
Intoxicação por Tetracloreto de Carbono/diagnóstico , Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Animais , Tetracloreto de Carbono/administração & dosagem , Intoxicação por Tetracloreto de Carbono/etiologia , Intoxicação por Tetracloreto de Carbono/patologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Injeções Intraperitoneais , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Necrose/induzido quimicamente , Necrose/diagnóstico , Índice de Gravidade de Doença , Fatores Sexuais , Testes de Toxicidade Aguda/métodos
7.
Hepatology ; 70(1): 259-275, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30865310

RESUMO

Although thousands of long noncoding RNAs (lncRNAs) have been annotated, only a limited number of them have been functionally characterized. Here, we identified an oncogenic lncRNA, named lnc-UCID (lncRNA up-regulating CDK6 by interacting with DHX9). Lnc-UCID was up-regulated in hepatocellular carcinoma (HCC), and a higher lnc-UCID level was correlated with shorter recurrence-free survival of HCC patients. Both gain-of-function and loss-of function studies revealed that lnc-UCID enhanced cyclin-dependent kinase 6 (CDK6) expression and thereby promoted G1/S transition and cell proliferation. Studies from mouse xenograft models revealed that tumors derived from lnc-UCID-silenced HCC cells had a much smaller size than those from control cells, and intratumoral injection of lnc-UCID small interfering RNA suppressed xenograft growth. Mechanistically, the 850-1030-nt domain of lnc-UCID interacted physically with DEAH (Asp-Glu-Ala-His) box helicase 9 (DHX9), an RNA helicase. On the other hand, DHX9 post-transcriptionally suppressed CDK6 expression by binding to the 3'-untranslated region (3'UTR) of CDK6 mRNA. Further investigation disclosed that lnc-UCID enhanced CDK6 expression by competitively binding to DHX9 and sequestering DHX9 from CDK6-3'UTR. In an attempt to explore the mechanisms responsible for lnc-UCID up-regulation in HCC, we found that the lnc-UCID gene was frequently amplified in HCC. Furthermore, miR-148a, whose down-regulation was associated with an increase of lnc-UCID in HCC, could bind lnc-UCID and inhibit its expression. Conclusion: Up-regulation of lnc-UCID, which may result from amplification of its gene locus and down-regulation of miR-148a, can promote HCC growth by preventing the interaction of DHX9 with CDK6 and subsequently enhancing CDK6 expression. These findings provide insights into the biological functions of lncRNAs, the regulatory network of cell cycle control, and the mechanisms of HCC development, which may be exploited for anticancer therapy.


Assuntos
Carcinoma Hepatocelular/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , RNA Helicases DEAD-box/metabolismo , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , Proteínas de Neoplasias/metabolismo , Animais , Carcinoma Hepatocelular/etiologia , Ciclo Celular , Células HEK293 , Células Hep G2 , Humanos , Neoplasias Hepáticas/etiologia , Camundongos , RNA Longo não Codificante/metabolismo
8.
Zhongguo Zhong Yao Za Zhi ; 43(21): 4311-4316, 2018 Nov.
Artigo em Zh | MEDLINE | ID: mdl-30583634

RESUMO

The aim of this paper was to observe the effect of gambogenic acid on angiogenesis of lung cancer and its preliminary mechanism. After culturing lung adenocarcinoma A549 cells, the conditioned medium was treated with gambogenic acid and then used to culture human umbilical vein endothelial cells (HUVECs) to establish the indirect contact cell co-culture system. A two-dimensional culture model of HUVEC was established with matrigel to observe the effect of gambogenic acid on angiogenesis. DAPI staining was used to observe the morphological changes in HUVEC cells after treatment with gambogenic acid under the fluorescence microscope. Annexin V-FITC/PI staining and flow cytometry analysis were used to determine gambogenic acid's effect on HUVEC cell apoptosis rate. The protein expressions of PI3K, p-PI3K, Akt, p-Akt were measured by Western blot. PTEN-siRNA was transfected into cells, and RT-PCR was used to detect the expression levels of PI3K and Akt genes. Gambogenic acid can significantly inhibit angiogenesis, and its inhibitory effect was dose-dependent. DAPI staining showed apoptotic morphological features of HUVEC cells under fluorescence microscope. Annexin V-FITC/PI staining showed that gambogenic acid induced apoptosis in HUVECs. The results of Western blot showed that the expressions of p-PI3K and p-Akt protein were down-regulated with gambogenic acid, while the expressions of PI3K and Akt protein was insignificant. The results of RT-PCR indicated that the expressions of PI3K and Akt protein were up-regulated by PTEN siRNA. Gambogenic acid can inhibit angiogenesis in lung cancer in vitro, and the mechanism of inhibiting angiogenesis may be related to the PI3K/Akt signaling pathway.


Assuntos
Apoptose , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Neovascularização Patológica/patologia , Xantenos/farmacologia , Células A549 , Técnicas de Cocultura , Humanos , Neoplasias Pulmonares/tratamento farmacológico , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transfecção
9.
Plant Cell Rep ; 36(7): 1053-1064, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28405745

RESUMO

KEY MESSAGE: An albinic rice is caused by mutation of threonyl-tRNA synthetase, which is essential for plant development by stabilizing of NEP and PEP gene expressions and chloroplast protein synthesis. Chloroplast biogenesis and development depend on complex genetic mechanisms. Apart from their function in translation, aminoacyl-tRNA synthetases (aaRSs) play additional role in gene expression regulation, RNA splicing, and cytokine activity. However, their detailed functions in plant development are still poorly understood. We isolated a lethal albinic seedling (las) mutant in rice. Physiological and ultrastructural analysis of las mutant plants revealed weak chlorophyll fluorescence, negligible chlorophyll accumulation, and defective thylakoid membrane development. By map based cloning we determined that the LAS allele gene encodes threonyl-tRNA synthetase (ThrRS). LAS was constitutively expressed with relatively high level in leaves. NEP-dependent gene transcripts accumulated in the developing chloroplasts, while PEP-dependent transcripts were reduced in the las mutant. This result indicated that PEP activity was impaired. Chloroplast-encoded protein levels were sharply reduced in the las mutant. Biogenesis of chloroplast rRNAs (16S and 23S rRNA) was arrested, leading to impaired translation and protein synthesis. Together, our findings indicated that LAS is essential not only for chloroplast development by stabilizing the NEP and PEP gene expression, but also for protein synthesis and construction of the ribosome system in rice chloroplasts.


Assuntos
Oryza/enzimologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plântula/enzimologia , Plântula/metabolismo , Treonina-tRNA Ligase/metabolismo , Proteínas de Cloroplastos/genética , Proteínas de Cloroplastos/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/genética , Mutação , Oryza/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plastídeos/enzimologia , Plastídeos/genética , Plastídeos/metabolismo , Plântula/genética , Treonina-tRNA Ligase/genética
10.
Angew Chem Int Ed Engl ; 54(28): 8231-5, 2015 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-26032302

RESUMO

An unprecedented Pd-catalyzed regioselective activation of gem-difluorinated cyclopropanes induced by C-C bond cleavage is reported. It provides a general and efficient access to a variety of 2-fluoroallylic amines, ethers, esters, and alkylation products in high Z-selectivity, which are important skeletons in many biologically active molecules. In addition, the transformation represents the first general application of gem-difluorinated cyclopropanes as reaction partners in transition-metal-catalyzed cross-coupling reaction.


Assuntos
Alquilação/fisiologia , Ciclopropanos/química , Halogenação/fisiologia , Paládio/química , Catálise , Estrutura Molecular , Estereoisomerismo
11.
Tumour Biol ; 35(2): 1403-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24078446

RESUMO

Recent population studies suggest that the use of artemisinin is associated with reduced incidence and improved prognosis of certain cancers. In the current study, we assessed the effect of artemisinin on gastric cancer cells (AGS and MKN74 cells). We found that artemisinin inhibited growth and modulated expression of cell-cycle regulators in these cells. Treatment with artemisinin was also associated with induction of p27 kip1 and p21 kip1, two negative cell-cycle regulators. Furthermore, we revealed that artemisinin treatment led to an increased expression of p53. Taken together, these results provide evidence for a mechanism that may contribute to the antineoplastic effects of artemisinin suggested by recent population studies and justify further work to explore potential roles for it in gastric cancer prevention and treatment.


Assuntos
Artemisininas/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Gástricas/tratamento farmacológico , Proteína Supressora de Tumor p53/biossíntese , Apoptose/efeitos dos fármacos , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteína Supressora de Tumor p53/genética
12.
Open Forum Infect Dis ; 11(1): ofad614, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38192381

RESUMO

Background: The Taiwanese government made a concerted effort to contain a coronavirus disease 2019 (COVID-19) nosocomial outbreak of variant B.1.429, shortly before universal vaccination program implementation. This study aimed to investigate seroprevalence in the highest-risk regions. Methods: Between January and February 2021, we retrieved 10 000 repository serum samples from blood donors to examine for antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) and spike (S) antigens. A positive result was confirmed if anti-N and anti-S antibodies were positive. Overall, 2000 donors residing in the highest-risk district and donating blood in January 2021 were further examined for SARS-CoV-2 RNA. We estimated seroprevalence and compared the epidemic curve between confirmed COVID-19 cases and blood donors with positive antibodies or viral RNA. Results: Twenty-one cases with COVID-19 were confirmed in the nosocomial cluster, with an incidence of 1.27/100 000 in the COVID-affected districts. Among 4888 close contacts of the nosocomial cases, 20 (0.4%) became confirmed cases during isolation. Anti-SARS-CoV-2 was detected in 2 of the 10000 blood donors, showing a seroprevalence of 2/10000 (95% CI, 0.55-7.29). None of the 2000 donors who underwent tests for SARS-CoV-2 RNA were positive. The SARS-CoV-2 infection epidemic curve was observed sporadically in blood donors compared with the nosocomial cluster. Conclusions: In early 2021, an extremely low anti-SARS-CoV-2 seroprevalence among blood donors was observed. Epidemic control measures through precise close contact tracing, testing, and isolation effectively contained SARS-CoV-2 transmission before universal vaccination program implementation.

13.
Cell Death Dis ; 14(11): 746, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37968256

RESUMO

DNA double-strand breaks (DSBs) are the fatal type of DNA damage mostly induced by exposure genome to ionizing radiation or genotoxic chemicals. DSBs are mainly repaired by homologous recombination (HR) and nonhomologous end joining (NHEJ). To repair DSBs, a large amount of DNA repair factors was observed to be concentrated at the end of DSBs in a specific spatiotemporal manner to form a repair center. Recently, this repair center was characterized as a condensate derived from liquid-liquid phase separation (LLPS) of key DSBs repair factors. LLPS has been found to be the mechanism of membraneless organelles formation and plays key roles in a variety of biological processes. In this review, the recent advances and mechanisms of LLPS in the formation of DSBs repair-related condensates are summarized.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Reparo do DNA/genética , Reparo do DNA por Junção de Extremidades , Dano ao DNA , DNA
14.
Sci Rep ; 13(1): 4832, 2023 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-36964267

RESUMO

Cataract, the leading cause of blindness worldwide, is caused by crystallin protein aggregation within the protected lens environment. Phase separation has been implicated as an important mechanism of protein aggregation diseases, such as neurodegeneration. Similarly, cataract has been proposed to be a protein condensation disease in the last century. However, whether crystallin proteins aggregate via a phase separation mechanism and which crystallin protein initiates the aggregation remain unclear. Here, we showed that all types of crystallin-GFP proteins remain soluble under physiological conditions, including protein concentrations, ion strength, and crowding environments. However, in age or disease-induced aberrant conditions, α-crystallin-GFP, including αA- and αB-crystallin-GFP, but not other crystallin-GFP proteins, undergo phase separation in vivo and in vitro. We found that aging-related changes, including higher crystallin concentrations, increased Na+, and decreased K+ concentrations, induced the aggregation of α-crystallin-GFP. Furthermore, H2O2, glucose, and sorbitol, the well-known risk factors for cataract, significantly enhanced the aggregation of αB-crystallin-GFP. Taken together, our results revealed that α-crystallin-GFP forms aggregates via a phase transition process, which may play roles in cataract disease. Opposite to the previously reported function of enhancing the solubility of other crystallin, α-crystallin may be the major aggregated crystallin in the lens of cataract patients.


Assuntos
Catarata , Cristalinas , Cristalino , Cadeia A de alfa-Cristalina , alfa-Cristalinas , Humanos , alfa-Cristalinas/metabolismo , Cristalinas/genética , Cristalinas/metabolismo , Agregados Proteicos , Peróxido de Hidrogênio/metabolismo , Catarata/metabolismo , Cristalino/metabolismo
15.
Nucleus ; 14(1): 2293599, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38105528

RESUMO

Noncoding RNAs have been found to play important roles in DNA damage repair, whereas the participation of circRNA remains undisclosed. Here, we characterized ciRS-7, a circRNA containing over 70 putative miR-7-binding sites, as an enhancer of miRISC condensation and DNA repair. Both in vivo and in vitro experiments confirmed the condensation of TNRC6B and AGO2, two core protein components of human miRISC. Moreover, overexpressing ciRS-7 largely increased the condensate number of TNRC6B and AGO2 in cells, while silencing ciRS-7 reduced it. Additionally, miR-7 overexpression also promoted miRISC condensation. Consistent with the previous report that AGO2 participated in RAD51-mediated DNA damage repair, the overexpression of ciRS-7 significantly promoted irradiation-induced DNA damage repair by enhancing RAD51 recruitment. Our results uncover a new role of circRNA in liquid-liquid phase separation and provide new insight into the regulatory mechanism of ciRS-7 on miRISC function and DNA repair.


Assuntos
MicroRNAs , RNA Circular , Humanos , RNA Circular/genética , Separação de Fases , MicroRNAs/genética , MicroRNAs/metabolismo , Reparo do DNA/genética , Dano ao DNA , Proteínas de Ligação a RNA/metabolismo
16.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o689-90, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412582

RESUMO

In the centrosymmetric title compound, C(12)H(10)O(2)S(2), the alkyl chains adopt a fully extended all-trans conformation with respect to the C(thio-phene)-C bond. The non-H atoms of the mol-ecule are nearly planar, with a maximum deviation of 0.063 (2) Šfrom the mean plane of the constituent atoms. In the crystal, symmetry-related mol-ecules are linked via pairs of C-H⋯π contacts [H-centroid distances of the thio-phene units = 2.79 (9) and 2.82 (4) Å], in turn inter-digitating with each other along the bc plane, thus leading to an inter-woven two-dimensional network.

18.
J Contemp Brachytherapy ; 14(4): 332-340, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36199952

RESUMO

Purpose: To evaluate the efficacy of radiotherapy in locally advanced cervical cancer, and to determine the factors affecting prognosis. Material and methods: Clinical data of 211 patients with cervical cancer, treated at our institution between June 2014 and February 2017 were reviewed retrospectively. All patients were treated with definitive radiotherapy and received external irradiation of 45-50.4 Gy. High-dose-rate brachytherapy (HDR-BT) of 24-36 Gy was prescribed to a high-risk clinical target volume (HR-CTV) as a local boost. All statistical analyses were performed with SPSS version 19.0 using Kaplan-Meier survival test and Cox regression analysis. Additionally, dose parameters of patients with IIIB stage treated with combined intracavitary/interstitial (IC/IS) implants were compared with IC only. Results: With a median follow-up time of 69 months, local control (LC), overall survival (OS), disease-free survival (DFS), and nodal control (NC) at 5 years were 89%, 78%, 67%, and 88%, respectively. In multivariate analysis, the major determinant of LC was the level of pre-treatment squamous cell carcinoma antigen (SCC-Ag). The predictors of shorter OS were adenocarcinoma, pre-treatment SCC-Ag, and FIGO stage. Worse DFS was associated with adenocarcinoma, pre-treatment SCC-Ag, and involved lymph nodes. The predictors for nodal failure were positive pelvic lymph nodes. Patients with IIIB treated with IC/IS brachytherapy tended to improve DFS compared with IC alone, and obtained similar HR-CTV D90 EQD2 (n = 10) and biological effective dose (BED), 91 ±6 Gy vs. 89 ±3 Gy, and 107 ±4.5 Gy vs. 107 ±5.6 Gy, whereas decreased organs at risk (OARs) doses, including rectum and bladder D2cm3 were 7.5 Gy and 7.2 Gy lower, respectively. Late grade 3-4 bladder and bowel toxicities were observed in 1.9% of patients. Conclusions: Radiation therapy carried out in our institution results in good survival, with acceptable toxicity in locally advanced cervical cancer. Different individualized therapeutic strategies should be considered for patients with high-risk factors.

19.
Anal Cell Pathol (Amst) ; 2022: 9675466, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35498155

RESUMO

Cervical cancer (CC) is among the most prevalent cancers among female populations with high recurrence rates all over the world. Cisplatin (DDP) is the first-line treatment for multiple cancers, including CC. The main problem associated with its clinical application is drug resistance. This study is aimed at investigating the function and downstream regulation mechanism of forkhead-box A1 (FOXA1) in CC, which was verified as an oncogene in several cancers. Using GEO database and bioinformatics analysis, we identified FOXA1 as a possible oncogene in CC. Silencing of FOXA1 inhibited CC cell growth, invasion, and chemoresistance. Afterwards, the downstream gene of FOXA1 was predicted using a bioinformatics website and validated using ChIP and dual-luciferase assays. SIX4, a possible target of FOXA1, promoted CC cell malignant aggressiveness and chemoresistance. In addition, overexpression of SIX4 promoted phosphorylation of PI3K and AKT proteins and activated the PI3K/AKT signaling pathway. Further overexpression of SIX4 reversed the repressive effects of FOXA1 knockdown on CC cell growth, invasion, and chemoresistance in DDP-resistant cells. FOXA1-induced SIX4 facilitates CC progression and chemoresistance, highlighting a strong potential for FOXA1 to serve as a promising therapeutic target in CC.


Assuntos
Neoplasias do Colo do Útero , Transformação Celular Neoplásica , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Fator 3-alfa Nuclear de Hepatócito/genética , Proteínas de Homeodomínio , Humanos , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transativadores , Neoplasias do Colo do Útero/genética
20.
Cell Death Discov ; 8(1): 436, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36316314

RESUMO

Aberrant DNA damage response (DDR) axis remains the major molecular mechanism for tumor radio-resistance. We recently characterized liquid-liquid phase separation (LLPS) as an essential mechanism of DDR, and identified several key DDR factors as potential LLPS proteins, including nucleolar protein NOP53. In this study, we found that NOP53 formed highly concentrated droplets in vivo and in vitro, which had liquid-like properties including the fusion of adjacent condensates, rapid fluorescence recovery after photobleaching and the sensitivity to 1,6-hexanediol. Moreover, the intrinsically disordered region 1 (IDR1) is required for NOP53 phase separation. In addition, multivalent-arginine-rich linear motifs (M-R motifs), which are enriched in NOP53, were essential for its nucleolar localization, but were dispensable for the LLPS of NOP53. Functionally, NOP53 silencing diminished tumor cell growth, and significantly sensitized colorectal cancer (CRC) cells to radiotherapy. Mechanically, NOP53 negatively regulated p53 pathway in CRC cells treated with or without radiation. Importantly, data from clinical samples confirmed a correlation between NOP53 expression and tumor radio-resistance. Together, these results indicate an important role of NOP53 in radio-resistance, and provide a potential target for tumor radio-sensitization.

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