Guidelines and definitions for research on epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) encompasses dynamic changes in cellular organization from epithelial to mesenchymal phenotypes, which leads to functional changes in cell migration and invasion. EMT occurs in a diverse range of physiological and pathological conditions and is driven by a conserved set of inducing signals, transcriptional regulators and downstream effectors. With over 5,700 publications indexed by Web of Science in 2019 alone, research on EMT is expanding rapidly. This growing interest warrants the need for a consensus among researchers when referring to and undertaking research on EMT. This Consensus Statement, mediated by 'the EMT International Association' (TEMTIA), is the outcome of a 2-year-long discussion among EMT researchers and aims to both clarify the nomenclature and provide definitions and guidelines for EMT research in future publications. We trust that these guidelines will help to reduce misunderstanding and misinterpretation of research data generated in various experimental models and to promote cross-disciplinary collaboration to identify and address key open questions in this research field. While recognizing the importance of maintaining diversity in experimental approaches and conceptual frameworks, we emphasize that lasting contributions of EMT research to increasing our understanding of developmental processes and combatting cancer and other diseases depend on the adoption of a unified terminology to describe EMT.

NAC1 promotes stemness and regulates myeloid-derived cell status in triple-negative breast cancer.

Triple negative breast cancer (TNBC) is a particularly lethal breast cancer (BC) subtype driven by cancer stem cells (CSCs) and an immunosuppressive microenvironment. Our study reveals that nucleus accumbens associated protein 1 (NAC1), a member of the BTB/POZ gene family, plays a crucial role in TNBC by maintaining tumor stemness and influencing myeloid-derived suppressor cells (MDSCs). High NAC1 expression correlates with worse TNBC prognosis. NAC1 knockdown reduced CSC markers and tumor cell proliferation, migration, and invasion. Additionally, NAC1 affects oncogenic pathways such as the CD44-JAK1-STAT3 axis and immunosuppressive signals (TGFß, IL-6). Intriguingly, the impact of NAC1 on tumor growth varies with the host immune status, showing diminished tumorigenicity in natural killer (NK) cell-competent mice but increased tumorigenicity in NK cell-deficient ones. This highlights the important role of the host immune system in TNBC progression. In addition, high NAC1 level in MDSCs also supports TNBC stemness. Together, this study implies NAC1 as a promising therapeutic target able to simultaneously eradicate CSCs and mitigate immune evasion.

Targeting the hydrophobic region of pyroglutamate-modified amyloid-ß by tyrocidine A prevents its nucleation-aggregation process and its "catalytic effect" on the Aßs aggregation.

Pyroglutamate (pE)-modified amyloid-ß (Aß) peptides play a crucial role in the development of Alzheimer's disease. pEAß3-42 can rapidly form oligomers that gradually elongate hydrophobic segments to form ß-sheet-rich amyloid intermediates, ultimately resulting in the formation of mature amyloid fibrils. pEAß3-42 can also catalyze the aggregation of Aß species and subsequently accelerate the formation of amyloid senile plaques. Considering the recent clinical success of the pEAß3-42-targeting antibody donanemab, molecules that strongly bind pEAß3-42 and prevent its aggregation and catalytic effect on Aßs may also provide potential therapeutic options for Alzheimer's disease. Here, we demonstrate that the natural antibiotic cyclopeptide tyrocidine A (TA) not only strongly inhibits the aggregation of Aß1-42 as previously reported, but also interacts with the hydrophobic C-terminus and middle domain of pEAß3-42 to maintain an unordered conformation, effectively impeding the formation of initial oligomers and subsequently halting the aggregation of pEAß3-42. Furthermore, TA can disrupt the "catalytic effect" of pEAß3-42 on amyloid aggregates, effectively suppressing Aß aggregation and ultimately preventing the pathological events induced by Aßs.

Hsp47 promotes cancer metastasis by enhancing collagen-dependent cancer cell-platelet interaction.

Increased expression of extracellular matrix (ECM) proteins in circulating tumor cells (CTCs) suggests potential function of cancer cell-produced ECM in initiation of cancer cell colonization. Here, we showed that collagen and heat shock protein 47 (Hsp47), a chaperone facilitating collagen secretion and deposition, were highly expressed during the epithelial-mesenchymal transition (EMT) and in CTCs. Hsp47 expression induced mesenchymal phenotypes in mammary epithelial cells (MECs), enhanced platelet recruitment, and promoted lung retention and colonization of cancer cells. Platelet depletion in vivo abolished Hsp47-induced cancer cell retention in the lung, suggesting that Hsp47 promotes cancer cell colonization by enhancing cancer cell-platelet interaction. Using rescue experiments and functional blocking antibodies, we identified type I collagen as the key mediator of Hsp47-induced cancer cell-platelet interaction. We also found that Hsp47-dependent collagen deposition and platelet recruitment facilitated cancer cell clustering and extravasation in vitro. By analyzing DNA/RNA sequencing data generated from human breast cancer tissues, we showed that gene amplification and increased expression of Hsp47 were associated with cancer metastasis. These results suggest that targeting the Hsp47/collagen axis is a promising strategy to block cancer cell-platelet interaction and cancer colonization in secondary organs.

Access to acridones by tandem copper(I)-catalyzed electrophilic amination/Ag(I)-mediated oxidative annulation of anthranils with arylboronic acids.

An efficient and practical approach for the synthesis of medicinally important acridones was developed from anthranils and commercially available arylboronic acids by a tandem copper(I)-catalyzed electrophilic amination/Ag(I)-mediated oxidative annulation strategy. This new and straightforward protocol displayed a broad substrate scope (25 examples) and high functional group tolerance. What's more, a possible mechanistic proposal was also presented.

ITCH nuclear translocation and H1.2 polyubiquitination negatively regulate the DNA damage response.

The downregulation of the DNA damage response (DDR) enables aggressive tumors to achieve uncontrolled proliferation against replication stress, but the mechanisms underlying this process in tumors are relatively complex. Here, we demonstrate a mechanism through which a distinct E3 ubiquitin ligase, ITCH, modulates DDR machinery in triple-negative breast cancer (TNBC). We found that expression of a nuclear form of ITCH was significantly increased in human TNBC cell lines and tumor specimens. Phosphorylation of ITCH at Ser257 by AKT led to the nuclear localization of ITCH and ubiquitination of H1.2. The ITCH-mediated polyubiquitination of H1.2 suppressed RNF8/RNF168-dependent formation of 53BP1 foci, which plays important roles in DDR. Consistent with these findings, impaired ITCH nuclear translocation and H1.2 polyubiquitination sensitized cells to replication stress and limited cell growth and migration. AKT activation of ITCH-H1.2 axis may confer TNBC cells with a DDR repression to counteract the replication stress and increase cancer cell survivorship and growth potential.

Potential protein markers for breast cancer recurrence: a retrospective cohort study.

BACKGROUND: We evaluated five key proteins involved in various cancer-related pathways and assessed their relation to breast cancer recurrence. METHODS: We used the Kentucky Cancer Registry to retrospectively identify primary invasive breast cancer cases (n = 475) that were diagnosed and treated at University of Kentucky Medical Center between 2000 and 2007. Breast cancer recurrence was observed in 62 cases during the 5-year follow-up after diagnosis. Protein expression or activity level was analyzed from surgery tissue using immuno-histochemical assays. RESULTS: Compared to ER+/PR+/HER2- patients without recurrence, those with recurrence had higher TWIST expression (p = 0.049) but lower ABL1/ABL2 activity (p = 0.003) in primary tumors. We also found that triple-negative breast cancer patients with recurrence had higher SNAI1 expression compared to those without recurrence (p = 0.03). After adjusting for potential confounders, the higher ABL1/ABL2 activity in primary tumors was associated with a decreased risk of recurrence (OR 0.72, 95% CI 0.85-0.90) among ER+/PR+/HER2- patients. In addition, among patients with recurrence we observed that the activity level of ABL1/ABL2 was significantly increased in recurrent tumors compared to the matched primary tumors regardless of the subtype (p = 0.013). CONCLUSIONS: These findings provide evidence that the expression/activity level of various proteins may be differentially associated with risk of recurrence of breast tumor subtypes.

Raloxifene alleviates amyloid-ß-induced cytotoxicity in HT22 neuronal cells via inhibiting oligomeric and fibrillar species formation.

Raloxifene, a selective estrogen receptor modulator, displays benefits for Alzheimer's disease (AD) prevention in postmenopausal women as hormonal changes during menopause have the potential to influence AD pathogenesis, but the underlying mechanism of its neuroprotection is not entirely clear. In this study, the effects of raloxifene on amyloid-ß (Aß) amyloidogenesis were evaluated. The results demonstrated that raloxifene inhibits Aß42 aggregation and destabilizes preformed Aß42 fibrils through directly interacting with the N-terminus and middle domains of Aß42 peptides. Consequently, raloxifene not only reduces direct toxicity of Aß42 in HT22 neuronal cells, but also suppresses expressions of tumor necrosis factor-α and transforming growth factor-ß induced by Aß42 peptides, and then alleviates microglia-mediated indirect toxicity of Aß42 to HT22 neuronal cells. Our results suggested an alternative possible explanation for the neuroprotective activity of raloxifene in AD prevention.

(+)-Isobicyclogermacrenal and spathulenol from Aristolochia yunnanensis alleviate cardiac fibrosis by inhibiting transforming growth factor ß/small mother against decapentaplegic signaling pathway.

Cardiac fibrosis contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. Antifibrotic therapies are likely to be a crucial strategy in curbing many fibrosis-related cardiac diseases. In our previous study, an ethyl acetate extract of a traditional Chinese medicine Aristolochia yunnanensis Franch. was found to have a therapeutic effect on myocardial fibrosis in vitro and in vivo. However, the exact chemicals and their mechanisms responsible for the activity of the crude extract have not been illustrated yet. In the current study, 10 sesquiterpenoids (1-10) were isolated from the active extract, and their antifibrotic effects were systematically evaluated in transforming growth factor ß 1 (TGFß1)-stimulated cardiac fibroblasts and NIH3T3 fibrosis models. (+)-Isobicyclogermacrenal (1) and spathulenol (2) were identified as the main active components, being more potent than the well-known natural antifibrotic agent oxymatrine. Compounds 1 and 2 could inhibit the TGFß1-induced cardiac fibroblasts proliferation and suppress the expression of the fibrosis biomarkers fibronectin and α-smooth muscle actin via down-regulation of their mRNA levels. The mechanism study revealed that 1 and 2 could inhibit the phosphorylation of TGFß type I receptor, leading to the decrease of the phosphorylation levels of downstream Smad2/3, then consequently blocking the nuclear translocation of Smad2/3 in the TGFß/Smad signaling pathway. These findings suggest that 1 and 2 may serve as promising natural leads for the development of anticardiac fibrosis drugs.

POMC maintains tumor-initiating properties of tumor tissue-derived long-term-cultured breast cancer stem cells.

The identification and understanding of the molecular network of cancer stem cells (CSCs) have had a profound impact on our view of carcinogenesis and treatment strategy. Unfortunately, a major problem is that serial passages of CSCs from clinical solid tumor specimens currently are not available in any lab, and thus, reported data are difficult to confirm and intensively interrogated. Here, we have generated two tumor tissue-derived breast CSC (BCSC) lines that showed prolonged maintenance over 20 serial passages in vitro, while retaining their tumor-initiating biological properties. We then deciphered the intrinsic mechanism using analyses of mRNA expression array profiles. It has been determined that pro-opiomelanocortin (POMC) is closely related with protein phosphorylation mediated by G-protein-coupled estrogen receptor (GPER) in BCSC. Following, knockdown of POMC inhibits properties of mammosphere formation, CD44+ CD24- population, CD44 expression, and clonogenicity ability in BCSC. We found that inhibition of POMC attenuates phosphorylation of AKT2 and GSK3ß in BCSC. Further in vivo investigations demonstrated that POMC interference regulates proliferation of BCSC-bearing tumors. Combination of the clinical results that POMC positive expression is frequently upregulated in human breast cancer and POMC positivity correlated with a poor prognosis, POMC is a potential therapeutic target for BCSC. In conclusion, we have successfully established two long-term-cultured BCSC from clinical specimens. We further indicated that POMC acts as a potential therapeutic target and prognostic marker for future treatment of BCSC.

Autophagy regulation in the development and treatment of breast cancer.

Autophagy is a major catabolic process in which intracellular membrane structures, protein complexes, and lysosomes are formed as lysoautophagosome to degrade and renew cytoplasmic components. Autophagy is physiologically a strategy and mechanism for cellular homeostasis as well as adaptation to stress, and thus alterations in the autophagy machinery may lead to diverse pathological conditions. The role of autophagy in cancer is complex, and the current literature reflects this as a 'double-edged sword'. Autophagy shows promise as a novel therapeutic target in various types of breast cancer, inhibiting or increasing treatment efficacy in a context- and cell-type-dependent manner. This review aims to summarize the recent advances in the understanding of the mechanisms by which key modulators of autophagy participate in cancer metastasis, highlight different autophagy-deficient murine models for breast cancer study, and provide further impetus for the modulation of autophagy in anticancer therapy.

The impact of low-dose carcinogens and environmental disruptors on tissue invasion and metastasis.

The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.

EGFR phosphorylates and inhibits lung tumor suppressor GPRC5A in lung cancer.

BACKGROUND: GPRC5A is a retinoic acid inducible gene that is preferentially expressed in lung tissue. Gprc5a- knockout mice develop spontaneous lung cancer, indicating Gprc5a is a lung tumor suppressor gene. GPRC5A expression is frequently suppressed in majority of non-small cell lung cancers (NSCLCs), however, elevated GPRC5A is still observed in a small portion of NSCLC cell lines and tumors, suggesting that the tumor suppressive function of GPRC5A is inhibited in these tumors by an unknown mechanism. METHODS: In this study, we examined EGF receptor (EGFR)-mediated interaction and tyrosine phosphorylation of GPRC5A by immunoprecipitation (IP)-Westernblot. Tyrosine phosphorylation of GPRC5A by EGFR was systematically identified by site-directed mutagenesis. Cell proliferation, migration, and anchorage-independent growth of NSCLC cell lines stably transfected with wild-type GPRC5A and mutants defective in tyrosine phosphorylation were assayed. Immunohistochemical (IHC) staining analysis with specific antibodies was performed to measure the total and phosphorylated GPRC5A in both normal lung and lung tumor tissues. RESULT: We found that EGFR interacted with GPRC5A and phosphorylated it in two conserved double-tyrosine motifs, Y317/Y320 and Y347/ Y350, at the C-terminal tail of GPRC5A. EGF induced phosphorylation of GPRC5A, which disrupted GPRC5A-mediated suppression on anchorage-independent growth of NSCLC cells. On contrary, GPRC5A-4 F, in which the four tyrosine residues have been replaced with phenylalanine, was resistant to EGF-induced phosphorylation and maintained tumor suppressive activities. Importantly, IHC analysis with anti-Y317/Y320-P sites showed that GPRC5A was non-phosphorylated in normal lung tissue whereas it was highly tyrosine-phosphorylated in NSCLC tissues. CONCLUSION: GPRC5A can be inactivated by receptor tyrosine kinase via tyrosine phosphorylation. Thus, targeting EGFR can restore the tumor suppressive functions of GPRC5A in lung cancer.

The SNAG domain of Snail1 functions as a molecular hook for recruiting lysine-specific demethylase 1.

Epithelial-mesenchymal transition (EMT) is a transdifferentiation programme. The mechanism underlying the epigenetic regulation of EMT remains unclear. In this study, we identified that Snail1 interacted with histone lysine-specific demethylase 1 (LSD1). We demonstrated that the SNAG domain of Snail1 and the amine oxidase domain of LSD1 were required for their mutual interaction. Interestingly, the sequence of the SNAG domain is similar to that of the histone H3 tail, and the interaction of Snail1 with LSD1 can be blocked by LSD1 enzymatic inhibitors and a histone H3 peptide. We found that the formation of a Snail1-LSD1-CoREST ternary complex was critical for the stability and function of these proteins. The co-expression of these molecules was found in cancer cell lines and breast tumour specimens. Furthermore, we showed that the SNAG domain of Snail1 was critical for recruiting LSD1 to its target gene promoters and resulted in suppression of cell migration and invasion. Our study suggests that the SNAG domain of Snail1 resembles a histone H3-like structure and functions as a molecular hook for recruiting LSD1 to repress gene expression in metastasis.

Voltage activation induced MoO42- dissolution to enhance performance of iron doped nickel molybdate for oxygen evolution reaction.

Transition metal-based precatalysts are typically voltage-activated before electrochemical testing in the condition of alkaline oxygen evolution reaction. Nevertheless, the impact of voltage on the catalyst and the anion dissolution is frequently disregarded. In this study, Fe-doped NiMoO4 (Fe-NiMoO4) was synthesized as a precursor through a straightforward hydrothermal method, and MoFe-modified Ni (oxygen) hydroxide (MoFe-NiOxHy) was obtained via cyclic voltammetry (CV) activation. The effects of voltage on Fe-NiMoO4 and the dissolved inactive MoO42- ions in the process were examined in relation to OER performance. It has demonstrated that the crystallinity of the catalyst is reduced by voltage, thereby enhancing its electrocatalytic activity. The electron distribution state can be adjusted during the application of voltage, leading to the generation of additional active sites and an acceleration in the reaction rate. Additionally, MoO42- exhibits potential dependence during its dissolution. In the OER process, the dissolution of MoO42- enhances the reconstruction degree of Fe-NiMoO4 into the active substance and expedites the formation of active Ni(Fe)OOH. Hence, the optimized MoFe-NiOxHy exhibited exceptional electrocatalytic performance, with a current density of 100 mA cm-2 achieved at an overpotential of only 256 mV. This discovery contributes to a more comprehensive understanding of alkaline OER performance under the influence of applied voltage and the presence of inactive oxygen ions, offering a promising avenue for the development of efficient electrocatalysts.

Synthesis, antioxidant, and antimicrobial evaluation of some 2-arylbenzimidazole derivatives.

A series of 2-arylbenzimidazole derivatives (3a-3p and 4a-4i) were synthesized and evaluated as potential antioxidant and antimicrobial agents. Their antioxidant properties were evaluated by various in vitro assays including hydroxyl radical (HO) scavenging, superoxide radical anion (O2(-)) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, and ferric reducing antioxidant power. Results demonstrated that compounds with hydroxyl group at the 5-position of benzimidazole ring had a comparable or better antioxidant activity in comparison to standard antioxidant tert-butylhydroquinone (TBHQ). Markedly, compound 4h that showed the highest HO scavenging activity (EC50=46µM) in vitro had a significant reduction of 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced intracellular oxidative stress and H2O2-induced cell death. In addition, these compounds showed moderate to good inhibitory activity against Staphylococcus aureus selectively at noncytotoxic concentrations.

NF-κB represses retinoic acid receptor-mediated GPRC5A transactivation in lung epithelial cells to promote neoplasia.

Chronic inflammation is associated with lung tumorigenesis, in which NF-κB-mediated epigenetic regulation plays a critical role. Lung tumor suppressor G protein-coupled receptor, family C, member 5A (GPRC5A), is repressed in most non-small cell lung cancer (NSCLC); however, the mechanisms remain unclear. Here, we show that NF-κB acts as a transcriptional repressor in suppression of GPRC5A. NF-κB induced GPRC5A repression both in vitro and in vivo. Intriguingly, transactivation of NF-κB downstream targets was not required, but the transactivation domain of RelA/p65 was required for GPRC5A repression. NF-κB did not bind to any potential cis-element in the GPRC5A promoter. Instead, p65 was complexed with retinoic acid receptor α/ß (RARα/ß) and recruited to the RA response element site at the GPRC5A promoter, resulting in disrupted RNA polymerase II complexing and suppressed transcription. Notably, phosphorylation on serine 276 of p65 was required for interaction with RARα/ß and repression of GPRC5A. Moreover, NF-κB-mediated epigenetic repression was through suppression of acetylated histone H3K9 (H3K9ac), but not DNA methylation of the CpG islands, at the GPRC5A promoter. Consistently, a histone deacetylase inhibitor, but not DNA methylation inhibitor, restored GPRC5A expression in NSCLC cells. Thus, NF-κB induces transcriptional repression of GPRC5A via a complex with RARα/ß and mediates epigenetic repression via suppression of H3K9ac.