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1.
Mol Cell ; 83(19): 3502-3519.e11, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37751742

ABSTRACT

Cyst(e)ine is a key precursor for the synthesis of glutathione (GSH), which protects cancer cells from oxidative stress. Cyst(e)ine is stored in lysosomes, but its role in redox regulation is unclear. Here, we show that breast cancer cells upregulate major facilitator superfamily domain containing 12 (MFSD12) to increase lysosomal cyst(e)ine storage, which is released by cystinosin (CTNS) to maintain GSH levels and buffer oxidative stress. We find that mTORC1 regulates MFSD12 by directly phosphorylating residue T254, while mTORC1 inhibition enhances lysosome acidification that activates CTNS. This switch modulates lysosomal cyst(e)ine levels in response to oxidative stress, fine-tuning redox homeostasis to enhance cell fitness. MFSD12-T254A mutant inhibits MFSD12 function and suppresses tumor progression. Moreover, MFSD12 overexpression correlates with poor neoadjuvant chemotherapy response and prognosis in breast cancer patients. Our findings reveal the critical role of lysosomal cyst(e)ine storage in adaptive redox homeostasis and suggest that MFSD12 is a potential therapeutic target.

2.
J Pathol ; 260(1): 17-31, 2023 05.
Article in English | MEDLINE | ID: mdl-36715683

ABSTRACT

Macropinocytosis is an effective strategy to mitigate nutrient starvation. It can fuel cancer cell growth in nutrient-limited conditions. However, whether and how macropinocytosis contributes to the rapid proliferation of hepatocellular carcinoma cells, which frequently experience an inadequate nutrient supply, remains unclear. Here, we demonstrated that nutrient starvation strongly induced macropinocytosis in some hepatocellular carcinoma cells. It allowed the cells to acquire extracellular nutrients and supported their energy supply to maintain rapid proliferation. Furthermore, we found that the phospholipid flippase ATP9A was critical for regulating macropinocytosis in hepatocellular carcinoma cells and that high ATP9A levels predicted a poor outcome for patients with hepatocellular carcinoma. ATP9A interacted with ATP6V1A and facilitated its transport to the plasma membrane, which promoted plasma membrane cholesterol accumulation and drove RAC1-dependent macropinocytosis. Macropinocytosis inhibitors significantly suppressed the energy supply and proliferation of hepatocellular carcinoma cells characterised by high ATP9A expression under nutrient-limited conditions. These results have revealed a novel mechanism that overcomes nutrient starvation in hepatocellular carcinoma cells and have identified the key regulator of macropinocytosis in hepatocellular carcinoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/metabolism , Cell Membrane , Liver Neoplasms/metabolism , Nutrients , Phospholipids/metabolism
3.
Ecotoxicol Environ Saf ; 251: 114495, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36640572

ABSTRACT

Heavy metal (HM) is noxious element that cannot be biodegraded, thus accumulating in the environment and posing a serious threat to the ecology. Plant phylloplane harbors diverse microbial communities that profoundly influence ecosystem functioning and host health. With more HM accumulating around smelters, native plants and microbes in various habitats tend to suffer from HM. However, the response of phylloplane bacteria of native plants to HM remains unclear. Thus, this study aimed to explain the response of Tamarix ramosissima, a phylloplane bacterial community to HM as well as the effect of the process on host growth in situ by investigating the potential source of HM and bacterial community shift. Results showed that, in most cases, the contaminated site with high HM level caused more accumulation of HM in phylloplane and leaves. Moreover, HM in the phylloplane was not from the internal transport of the plant but it could be due to the wind action or rains. Bacteria in phylloplane may have come from the soil due to their strong positive correlation with corresponding soil at the genus level. High HM level inhibited the relative abundance of dominant bacteria, increased the diversity and species richness of bacterial community in phylloplane, and induced more special bacteria to maintain higher productivity of the host plant, for which, Cu and Pb were the major contributors. Meanwhile, bacteria in phylloplane showed a universal positive correlation in the co-occurrence network, which showed less stability than that in corresponding soil in the smelting region, and it is helpful to regulate the growth of plants more rapidly. Nearly 25% of KEGG pathways were modulated by high HM level and bacterial function tended to stabilize HM to avoid the potential process of leaf absorption. The study illustrated that HM in phylloplane played an important role in shaping the bacterial community of phylloplane as compared to HM in leaves or phyllosphere, and the resulting increase of diversity and richness of bacterial community and special bacteria further maintained the growth of the host plant suffering from HM stress.


Subject(s)
Metals, Heavy , Soil Pollutants , Tamaricaceae , Cadmium/metabolism , Lead/metabolism , Tamaricaceae/metabolism , Ecosystem , Metals, Heavy/analysis , Bacteria/metabolism , Soil/chemistry , Plants/metabolism , Zinc/analysis , Soil Pollutants/analysis
4.
J Pathol ; 254(3): 265-278, 2021 07.
Article in English | MEDLINE | ID: mdl-33797754

ABSTRACT

Chemoresistance is a major obstacle to the treatment of triple-negative breast cancer (TNBC), which has a poor prognosis. Increasing evidence has demonstrated the essential role of cancer stem cells (CSCs) in the process of TNBC chemoresistance. However, the underlying mechanism remains unclear. In the present study, we report that block of proliferation 1 (BOP1) serves as a key regulator of chemoresistance in TNBC. BOP1 expression was significantly upregulated in chemoresistant TNBC tissues, and high expression of BOP1 correlated with shorter overall survival and relapse-free survival in patients with TNBC. BOP1 overexpression promoted, while BOP1 downregulation inhibited the drug resistance and CSC-like phenotype of TNBC cells in vitro and in vivo. Moreover, BOP1 activated Wnt/ß-catenin signaling by increasing the recruitment of cyclic AMP response element-binding protein (CBP) to ß-catenin, enhancing CBP-mediated acetylation of ß-catenin, and increasing the transcription of downstream stemness-related genes CD133 and ALDH1A1. Notably, treating with the ß-catenin/CBP inhibitor PRI-724 induced an enhancement of chemotherapeutic response of paclitaxel in BOP1-overexpressing TNBC cells. These findings indicate that BOP1 is involved in chemoresistance development and might serve as a prognostic marker and therapeutic target in TNBC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Subject(s)
Drug Resistance, Neoplasm/physiology , Gene Expression Regulation, Neoplastic/physiology , RNA-Binding Proteins/metabolism , Triple Negative Breast Neoplasms/pathology , Acetylation , Animals , CREB-Binding Protein/metabolism , Female , Heterografts , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Triple Negative Breast Neoplasms/metabolism , Wnt Signaling Pathway/physiology
5.
Future Oncol ; 18(14): 1745-1756, 2022 May.
Article in English | MEDLINE | ID: mdl-35227076

ABSTRACT

Purpose: The authors aimed to evaluate the prognostic and predictive value of androgen receptor (AR) expression in patients with luminal/human EGFR2 negative (HER2-) T1N0 breast cancer. Methods: The cohort in this retrospective study comprised 471 patients with luminal/HER2- T1N0 breast cancer who had undergone surgery between 2013 and 2017 in the authors' center. Results: AR+ tumors were associated with favorable characteristics. AR+ patients had better 5-year recurrence-free survival rates and the risk of recurrence was greater for AR- than for AR+ patients. AR- status predicted the failure of adjuvant endocrine therapy with aromatase inhibitors and of adjuvant chemotherapy with docetaxel plus cyclophosphamide. Conclusion: AR+ expression is significantly related to a better prognosis. AR expression may be an additional biomarker for both endocrine and chemotherapy responsiveness.


Subject(s)
Breast Neoplasms , Receptor, ErbB-2 , Receptors, Androgen , Androgens , Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/diagnosis , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Disease-Free Survival , Docetaxel/therapeutic use , Female , Humans , Neoplasm Staging , Prognosis , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Receptors, Androgen/biosynthesis , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Retrospective Studies
6.
J Am Chem Soc ; 143(20): 7671-7680, 2021 05 26.
Article in English | MEDLINE | ID: mdl-33978400

ABSTRACT

Emulsification of immiscible two-phase fluids, i.e., one condensed phase dispersed homogeneously as tiny droplets in an outer continuous medium, plays a key role in medicine, food, chemical separations, cosmetics, fabrication of micro- and nanoparticles and capsules, and dynamic optics. Herein, we demonstrate that water clusters/droplets can be formed in an organic phase via the spontaneous assembling of ionic bilayers. We term these clusters ionosomes, by analogy with liposomes where water clusters are encapsulated in a bilayer of lipid molecules. The driving force for the generation of ionosomes is a unique asymmetrical electrostatic attraction at the water/oil interface: small and more mobile hydrated ions reside in the inner aqueous side, which correlate tightly with the lipophilic bulky counterions in the adjacent outer oil side. These ionosomes can be formed through electrochemical (using an external power source) or chemical (by salt distribution) polarization at the liquid-liquid interface. The charge density of the cations, the organic solvent, and the synergistic effects between tetraethylammonium and lithium cations, all affecting the formation of ionosomes, were investigated. These results clearly prove that a new emulsification strategy is developed providing an alternative and generic platform, besides the canonical emulsification procedure with either ionic or nonionic surfactants as emulsifiers. Finally, we also demonstrate the detection of individual ionosomes via single-entity electrochemistry.

7.
Anal Chem ; 93(7): 3353-3361, 2021 02 23.
Article in English | MEDLINE | ID: mdl-33550802

ABSTRACT

A novel approach has been developed for the selective determination of cations or anions based on the application of Fourier transformed staircase sinusoidal voltammetry (FT-SC-SV) in combination with the interface between two immiscible electrolyte solutions (ITIES) in the four-electrode configuration. The electrochemistry at the ITIES provides a very simple yet sensitive platform for the detection of a broad spectrum of redox inactive ions and even the neutral (bio)molecules that can be charged (e.g., protonated in appropriate pH). FT-SC-SV employs a complex potential excitation, i.e., a large-amplitude sine wave superimposed onto a dc bias potential that is stepped/scanned throughout the potential window. The response current is subsequently analyzed in the frequency domain by FT. Although the ions have close standard/formal transfer potential, discrimination and selective detection can be achieved by the higher harmonics. Feasibility and reliability of the proposed approach were verified with two pairs of ions that have very close transfer potentials across the ITIES and were chosen as the model systems. Besides, the additivity of the ionic current magnitude on concentration measured either in the mixture of ionic analytes or in individually prepared solutions containing the separate ionic analyte was tested. The experimental results prove that the principle of additivity holds. Compared with the traditional voltammetry, FT-SC-SV is simpler and more efficient in discrimination and quantification of apparently indistinguishable ion transfer from the viewpoint of thermodynamics. This demonstration may provide a new way for analytical detection of a broad range of redox inactive ions in terms of both fundamentals and applications.

8.
Anal Chem ; 93(27): 9495-9504, 2021 07 13.
Article in English | MEDLINE | ID: mdl-34196181

ABSTRACT

Collisional electrochemistry between single particles and a biomimetic polarized micro-liquid/liquid interface has emerged as a novel and powerful analytical method for measurements of single particles. Using this platform, rapid detection of liposomes at the single particle level is reported herein. Individual potassium, sodium, or protonated dopamine-encapsulated (pristine or protein-decorated) liposomes collide and fuse with the polarized micro-liquid/liquid interface accompanying the release of ions, which are recorded as spike-like current transients of stochastic nature. The sizing and concentration of the liposomes can be readily estimated by quantifying the amount of encapsulated ions in individual liposomes via integrating each current spike versus time and the spike frequency, respectively. We call this type of nanosensing technology "Faradaic counter". The estimated liposome size distribution by this method is in line with the dynamic light scattering (DLS) measurements, implying that the quantized current spikes are indeed caused by the collisions of individual liposomes. The reported electrochemical sensing technology may become a viable alternative to DLS and other commercial nanoparticle analysis systems, for example, nanoparticle tracking analysis.


Subject(s)
Dopamine , Liposomes , Ions , Particle Size , Potassium , Sodium
9.
FASEB J ; 34(8): 9959-9971, 2020 08.
Article in English | MEDLINE | ID: mdl-32427399

ABSTRACT

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype with high motile and invasive capacity that contributes to metastasis. Understanding the mechanisms for the motility of TNBC might provide novel targetable vulnerabilities of the tumors. Herein, we find that Rhophilin-associated tail protein 1 (ROPN1) is selectively overexpressed in human TNBC cell lines and tissues. Overexpression of ROPN1 promotes, while silencing of ROPN1 inhibits the robust migration, invasion, and in vivo metastasis of TNBC cells. Moreover, we find that ROPN1 activates RhoA signaling via rhophilin-1 (RHPN1), leading to enhanced actin stress fibers formation in TNBC cells. RhoA signaling is demonstrated to be essential for ROPN1-mediated migration and metastasis of TNBC cells. Finally, we find that high levels of ROPN1 are significantly associated distant metastasis and predicted poor prognosis in patients with breast cancer. These findings reveal a novel mechanism for the high motility and metastasis of TNBC cells, suggesting that ROPN1 might be a potential prognostic marker and therapeutic target.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cell Movement , Gene Expression Regulation, Neoplastic , Lung Neoplasms/secondary , Membrane Proteins/metabolism , Triple Negative Breast Neoplasms/pathology , rho GTP-Binding Proteins/metabolism , rhoA GTP-Binding Protein/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cell Proliferation , Female , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Membrane Proteins/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Prognosis , Signal Transduction , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , rho GTP-Binding Proteins/genetics , rhoA GTP-Binding Protein/genetics
10.
Anal Chem ; 89(17): 9284-9291, 2017 09 05.
Article in English | MEDLINE | ID: mdl-28758383

ABSTRACT

Single-emulsion toluene oil droplets (femtoliter) containing a hydrophobic redox probe that are dispersed in water stochastically collide with an ultramicroelectrode (UME). The fast-scan cyclic voltammetry (FSCV) or Fourier-transformed sinusoidal voltammetry (FTSV) is applied: the UME was scanned with a fast, repetitive triangular, or sinusoidal potential, and its current in time/frequency domains were monitored. The electron transfer at the UME/oil interface is coupled with ion transfer at the oil/water interface. Thus, the obtained transient voltammograms of a myriad of ions were used to estimate thermodynamics of ion transfer at the toluene/water interface. Additionally, the single-droplet voltammogram combined with finite element simulations reveal the droplet's size and shape distributions. Four collision mechanisms with new physical insights were also uncovered via comprehensive analysis of phase angle in the frequency domain, time domain FSCVs, and finite element simulations.

11.
Chemistry ; 22(28): 9523-7, 2016 Jul 04.
Article in English | MEDLINE | ID: mdl-27168168

ABSTRACT

Direct electrochemical characterization of freely moving nanoparticles (NPs) at the individual particle level is challenging. A method is presented that can achieve this goal based on the collision between a NP and an ultramicroelectrode (UME). By applying a sinusoidal potential to the UME and monitoring the current response in the frequency domain, a sudden change in the phase angle indicates the arrival of a NP at the UME. The response induced by the collision can be isolated and used to explore the properties of the NP. This method, analogous to a high-speed camera, can obtain a snapshot of the properties of the single NP at the moment of a collision. The proposed method was employed to investigate the properties of both the hard catalytic Pt NP and soft electroactive emulsion droplets, and many new insights were revealed thereafter. The method also has the potential to be applied in many other fields, where the interested signals appear as discrete events.

12.
Anal Chem ; 87(1): 448-56, 2015 Jan 06.
Article in English | MEDLINE | ID: mdl-25437710

ABSTRACT

Discrimination and quantification of electroactive species are traditionally realized by a potential difference which is mainly determined by thermodynamics. However, the resolution of this approach is limited to tens of millivolts. In this paper, we described an application of Fourier transformed sinusoidal voltammetry (FT-SV) that provides a new approach for discrimination and quantitative evaluation of electroactive species, especially thermodynamic similar ones. Numerical simulation indicates that electron transfer kinetics difference between electroactive species can be revealed by the phase angle of higher order harmonics of FT-SV, and the difference can be amplified order by order. Thus, even a very subtle kinetics difference can be amplified to be distinguishable at a certain order of harmonics. This method was verified with structurally similar ferrocene derivatives which were chosen as the model systems. Although these molecules have very close redox potential (<10 mV), discrimination and selective detection were achieved by as high as the thirteenth harmonics. The results demonstrated the feasibility and reliability of the method. It was also implied that the combination of the traditional thermodynamic method and this kinetics method can form a two-dimension resolved detection method, and it has the potential to extend the resolution of voltammetric techniques to a new level.

13.
Heliyon ; 10(3): e25082, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38322943

ABSTRACT

Based on a natural event, namely a pilot accountability audit of natural resources conducted by local officials in 2014, this study empirically investigates the impact of the pilot on the total factor productivity (TFP) of enterprises. The study utilizes the Differences-in-Differences model with an observation window spanning from 2012 to 2015. The findings indicate a significant reduction in the total factor productivity of enterprises in the pilot area due to the implementation of the pilot program. The study identifies that this impact is primarily driven by increased production costs and decreased investment. Further analysis reveals heterogeneity in the effects, with regions characterized by low levels of economic development, distortions in the production element market, low competition in industries, heavy asset-intensive industries, large enterprises, and absolute holding enterprises experiencing a more pronounced impact of the audit on total factor productivity. Overall, this study sheds light on the influence of accountability audits of natural resources on the real economy and offers valuable insights for policymakers.

14.
ACS Appl Mater Interfaces ; 16(12): 14561-14572, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38500377

ABSTRACT

Uridine diphosphate (UDP)-glucosyltransferases (UGTs) have received increasing attention in the field of ginsenoside Rh2 conversion. By harnessing the metal chelation between transition metal ions and imidazole groups present on His-tagged enzymes, a specific immobilization of the enzyme within metal-organic frameworks (MOFs) is achieved. This innovative approach not only enhances the stability and reusability of the enzyme but also enables one-step purification and immobilization. Consequently, the need for purifying crude enzyme solutions is effectively circumvented, resulting in significant cost savings during experimentation. The use of immobilized enzymes in catalytic reactions has shown great potential for achieving higher conversion rates of ginsenoside Rh2. In this study, highly stable mesoporous Zn-Ni MOF materials were synthesized at 150 °C by a solvothermal method. The UGT immobilized on the Zn-Ni MOF (referred to as UGT@Zn-Ni MOF) exhibited superior pH adaptability and thermal stability, retaining approximately 76% of its initial activity even after undergoing 7 cycles. Furthermore, the relative activity of the immobilized enzyme remained at an impressive 80.22% even after 45 days of storage. The strong specific adsorption property of Zn-Ni MOF on His-tagged UGT was confirmed through analysis using polyacrylamide gel electrophoresis. UGT@Zn-Ni MOF was used to catalyze the conversion reaction, and the concentration of rare ginsenoside Rh2 was generated at 3.15 µg/mL. The results showed that Zn-Ni MOF is a material that can efficiently purify and immobilize His-tagged enzyme in one step and has great potential for industrial applications in enzyme purification and ginsenoside synthesis.


Subject(s)
Ginsenosides , Glycosyltransferases , Enzymes, Immobilized/chemistry , Indicators and Reagents , Zinc
15.
Anal Chem ; 85(1): 83-90, 2013 Jan 02.
Article in English | MEDLINE | ID: mdl-23186366

ABSTRACT

Traditionally, the selectivity of voltammetric analysis depends on the difference of redox potential. Unfortunately, the limit of discrimination imposed by the voltammogram itself is dozens of millivolts. This suggests that it is impossible to achieve selective detection of one chemical under the interference of chemicals which have very close redox potential with the target chemical. Herein, we provided an attractive solution to this problem, using phase angle instead of potential as the basis of selectivity. Specifically, the electrochemical system was perturbed with a large-amplitude sinusoidal potential signal and the responsive current signal was subsequently analyzed in the frequency domain. This technique was termed as sinusoidal voltammetry (SV). The selective detection can be realized by quantifying the amplitude of a certain harmonic element at the characteristic "fingerprint" phase angle of each redox couple; and their phase angle difference can be regulated to be close to 90° to eliminate interferences and optimize the selective detection. Feasibility of the proposed approach was verified with a model system consisting of two ferrocene derivatives. The underlying theoretical basis was interpreted as that there are inherently several phase angle dramatic transition regions near the redox potential, and thus a minimum redox potential difference can generate a significant phase angle difference in those regions.

16.
IEEE Trans Cybern ; PP2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37708015

ABSTRACT

Completing low-rank matrices from subsampled measurements has received much attention in the past decade. Existing works indicate that O(nrlog2(n)) datums are required to theoretically secure the completion of an n ×n noisy matrix of rank r with high probability, under some quite restrictive assumptions: 1) the underlying matrix must be incoherent and 2) observations follow the uniform distribution. The restrictiveness is partially due to ignoring the roles of the leverage score and the oracle information of each element. In this article, we employ the leverage scores to characterize the importance of each element and significantly relax assumptions to: 1) not any other structure assumptions are imposed on the underlying low-rank matrix and 2) elements being observed are appropriately dependent on their importance via the leverage score. Under these assumptions, instead of uniform sampling, we devise an ununiform/biased sampling procedure that can reveal the "importance" of each observed element. Our proofs are supported by a novel approach that phrases sufficient optimality conditions based on the Golfing scheme, which would be of independent interest to the wider areas. Theoretical findings show that we can provably recover an unknown n×n matrix of rank r from just about O(nrlog2 (n)) entries, even when the observed entries are corrupted with a small amount of noisy information. The empirical results align precisely with our theories.

17.
J Cancer Res Clin Oncol ; 149(8): 4367-4380, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36109402

ABSTRACT

BACKGROUND: Triple-negative breast cancer (TNBC) is resistant to targeted therapy with HER2 monoclonal antibodies and endocrine therapy, because it lacks the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). TNBC is a subtype of breast cancer with the worst prognosis and the highest mortality rate compared to other subtypes. N6-methyladenosine (m6A) modification is significant in cancer and metastasis, because it can alter gene expression and function at numerous levels, such as RNA splicing, stability, translocation, and translation. There are limited investigations into the connection between TNBC and m6A. MATERIALS AND METHODS: Breast cancer-related data were retrieved from the Cancer Genome Atlas (TCGA) database, and 116 triple-negative breast cancer cases were identified from the data. The GSE31519 data set, which included 68 cases of TNBC, was obtained from the Gene Expression Omnibus (GEO) database. Survival analysis was used to determine the prognosis of distinct m6A types based on their m6A group, gene group, and m6A score. To investigate the potential mechanism, GO and KEGG analyses were performed on the differentially expressed genes. RESULTS: The expression of m6A-related genes and their impact on prognosis in TNBC patients were studied. According to the findings, m6A was crucial in determining the prognosis of TNBC patients, and the major m6A-linked genes in this process were YTHDF2, RBM15B, IGFBP3, and WTAP. YTHDF2, RBM15B and IGFBP3 are associated with poor prognosis, while WTAP is associated with good prognosis. By cluster analysis, the gene cluster and the m6A cluster were beneficial in predicting the prognosis of TNBC patients. The m6A score based on m6A and gene clusters was more effective in predicting the prognosis of TNBC patients. Furthermore, the tumor microenvironment may play an important role in the process of m6A, influencing TNBC prognosis. CONCLUSIONS: N6-adenylic acid methylation (m6A) was important in altering the prognosis of TNBC patients, and the key m6A-associated genes in this process were YTHDF2, RBM15B, IGFBP3, and WTAP. Furthermore, the comprehensive typing based on m6A and gene clusters was useful in predicting TNBC patients' prognosis, showing potential as valuable evaluating tools for TNBC.


Subject(s)
Triple Negative Breast Neoplasms , Humans , Triple Negative Breast Neoplasms/genetics , Prognosis , Multigene Family , Transcription Factors , Breast , Tumor Microenvironment
18.
J Phys Chem B ; 127(41): 8974-8981, 2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37796864

ABSTRACT

Single-entity collisional electrochemistry (SECE), a subfield of single-entity electrochemistry, enables directly characterizing entities and particles in the electrolyte solution at the single-entity resolution. Blockade SECE at the traditional solid ultramicroelectrode (UME)/electrolyte interface suffers from a limitation: only redox-inactive particles can be studied. The wide application of the classical Coulter counter is restricted by the rapid translocation of entities through the orifice, which results in a remarkable proportion of undetected signals. In response, the blocking effect of single charged conductive or insulating nanoparticles (NPs) at low concentrations for ion transfer (IT) at a miniaturized polarized liquid/liquid interface was successfully observed. Since the particles are adsorbed at the liquid/liquid interface, our method also solves the problem of the Coulter counter having a too-fast orifice translocation rate. The decreasing quantal staircase/step current transients are from landings (controlled by electromigration) of either conductive or insulating NPs onto the interface. This interfacial NP assembly shields the IT flux. The size of each NP can be calculated by the step height. The particle size measured by dynamic light scattering (DLS) is used for comparison with that calculated from electrochemical blocking events, which is in fairly good agreement. In short, the blocking effect of IT by single entities at micro- or submicro-liquid/liquid interface has been proven experimentally and is of great reference in single-entity detection.

19.
Theranostics ; 13(1): 339-354, 2023.
Article in English | MEDLINE | ID: mdl-36593950

ABSTRACT

Rationale: Chemoresistance is a major challenge in the clinical management of patients with breast cancer. Mutant p53 proteins tend to form aggregates that promote tumorigenesis in cancers. We here aimed to explore the mechanism for the generation of mutant p53 aggregates in breast cancer and assess its role in inducing chemoresistance. Methods: Expression of BCL2-associated athanogene 2 (BAG2) was evaluated by qRT-PCR, western blotting, and immunohistochemistry in breast cancer patient specimens. The significance of BAG2 expression in prognosis was assessed by Kaplan-Meier survival analysis and the Cox regression model. The roles of BAG2 in facilitating the formation of mutant p53 aggregates were analyzed by co-immunoprecipitation, immunofluorescence, and semi-denaturing detergent-agarose gel electrophoresis assays. The effects of BAG2 on the chemoresistance of breast cancer were demonstrated by cell function assays and mice tumor models. Results: In the present study, we found that BAG2 was significantly upregulated in relapse breast cancer patient tissues and high BAG2 was associated with a worse prognosis. BAG2 localized in mutant p53 aggregates and interacted with misfolded p53 mutants. BAG2 exacerbated the formation of the aggregates and recruited HSP90 to promote the propagation and maintenance of the aggregates. Consequently, BAG2-mediated mutant p53 aggregation inhibited the mitochondrial apoptosis pathway, leading to chemoresistance in breast cancer. Importantly, silencing of BAG2 or pharmacological targeting of HSP90 substantially reduced the aggregates and increased the sensitivity of chemotherapy in breast cancer. Conclusion: These findings reveal a significant role of BAG2 in the chemoresistance of breast cancer via exacerbating mutant p53 aggregates and suggest that BAG2 may serve as a potential therapeutic target for breast cancer patients with drug resistance.


Subject(s)
Breast Neoplasms , Drug Resistance, Neoplasm , Molecular Chaperones , Tumor Suppressor Protein p53 , Animals , Mice , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , HSP90 Heat-Shock Proteins/metabolism , Neoplasm Recurrence, Local , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Molecular Chaperones/genetics , Molecular Chaperones/metabolism , Breast Neoplasms/genetics , Humans , Female
20.
Cell Rep ; 42(6): 112542, 2023 06 27.
Article in English | MEDLINE | ID: mdl-37210725

ABSTRACT

Alternative splicing (AS) is a critical mechanism for the aberrant biogenesis of long non-coding RNA (lncRNA). Although the role of Wnt signaling in AS has been implicated, it remains unclear how it mediates lncRNA splicing during cancer progression. Herein, we identify that Wnt3a induces a splicing switch of lncRNA-DGCR5 to generate a short variant (DGCR5-S) that correlates with poor prognosis in esophageal squamous cell carcinoma (ESCC). Upon Wnt3a stimulation, active nuclear ß-catenin acts as a co-factor of FUS to facilitate the spliceosome assembly and the generation of DGCR5-S. DGCR5-S inhibits TTP's anti-inflammatory activity by protecting it from PP2A-mediated dephosphorylation, thus fostering tumor-promoting inflammation. Importantly, synthetic splice-switching oligonucleotides (SSOs) disrupt the splicing switch of DGCR5 and potently suppress ESCC tumor growth. These findings uncover the mechanism for Wnt signaling in lncRNA splicing and suggest that the DGCR5 splicing switch may be a targetable vulnerability in ESCC.


Subject(s)
Esophageal Neoplasms , Esophageal Squamous Cell Carcinoma , RNA, Long Noncoding , Humans , Esophageal Squamous Cell Carcinoma/genetics , RNA, Long Noncoding/genetics , Esophageal Neoplasms/genetics , Inflammation/genetics , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Cell Proliferation/genetics , Cell Movement/genetics
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