REVIEW | doi:10.20944/preprints202202.0258.v1
Subject: Materials Science, Nanotechnology Keywords: plasmonics; nanoscale; ablation; direct laser write; die-met
Online: 21 February 2022 (14:54:57 CET)
Nanoscale structuring/printing is of interest for range of applications in 3D subtractive and additive manufacturing (3D+/-). Basic principles of light field enhancement and control at the nanoscale are overviewed in this section/chapter for bulk, surface, and localised plasmons (1D, 2D, and 3D localisation, respectively). All these plasmons are resonant phenomena which have common Lorentzian spectral lineshape which relates refractive and absorption properties as well as defining the phase of transmitted and scattered light. Localisation of light at the nanoscale creates the possibility of modification with matching resolution. Harnessing this light enhancement can be demonstrated as a "nano-pen" for direct write nanolithography.
ARTICLE | doi:10.20944/preprints202103.0676.v1
Online: 26 March 2021 (16:29:10 CET)
Background: Disruption of alternative splicing (AS) is frequently observed in cancer and it might represent an important signature for tumor progression and therapy. Exon skipping (ES) represents one of the most frequent AS events and in non-small cell lung cancer (NSCLC) MET exon 14 skipping was shown to be targetable. Methods: We constructed a neural network (NN) specifically designed to detect MET exon 14 skipping events using RNAseq data. Furthermore, for discovery purpose we also developed a sparsely connected autoencoder to identify uncharacterized MET isoforms. Results: The NN had 100% Met exon 14 skipping detection rate, when tested on a manually curated set of 690 TCGA bronchus and lung samples. When globally applied to 2605 TCGA samples, we observed that the majority of false positives was characterized by a blurry coverage of exon 14, but interesting they share a common coverage peak in the second intron and we speculate that this event could be the transcription signature of a LINE1-MET fusion. Conclusions: Taken together our results indicate that neural networks can be an effective tool to provide a quick classification of pathological transcription events and sparsely connected autoencoders could represent the basis for the development of an effective discovery tool.
ARTICLE | doi:10.20944/preprints202012.0568.v1
Subject: Engineering, Automotive Engineering Keywords: die forging; isothermal annealing; thermo-mechanical treatment
Online: 22 December 2020 (16:13:53 CET)
The article discusses the results of investigations performed during a thermo-mechanical treatment of forgings made of chromium-molybdenum 42CrMo4 grade steel. The treatment was realized during a regular series production. The forging process was combined with a heat treatment carried out directly after forging on a specially adapted station. Such a production technology will make it possible to eliminate the step of repeated heating of the forgings. On the example of an element of a steering gear, it was demonstrated how it is possible to perform an isothermal annealing process starting from the temperature at which the trimming of the forgings ends. During the cooling of the forgings, it is enough to maintain the temperature at the proper level in order for the exothermal phase transformation of austenite into pearlite to take place. With an appropriate design of the processing line, the heat released during the transformation could be used to maintain the applied temperature, thus limiting the consumption of energy needed to power the devices. The test results show that, with the properly selected temperature of isothermal annealing, it is possible to obtain an equilibrial ferritic-pearlitic structure in the required hardness scope. Introducing such a solution into the industrial practice would allow significant savings of the energy used for the heat treatment.
ARTICLE | doi:10.20944/preprints202012.0269.v1
Subject: Engineering, Automotive Engineering Keywords: crank press; die forgings; joggles and shape errors; 3D scanning
Online: 10 December 2020 (17:31:44 CET)
The article proposes an indirect measurement method based on a dimensional and shape analysis of forgings for the evaluation of the manufacture and the proper operation of the key elements of the crank press, in which after modernization, a quick tool assembly based on SMED (Single Minute Exchange of Die) was implemented. As a result of the introduced changes aiming at improving the forging aggregate and increasing the production efficiency, errors were observed on the manufactured products-forgings in the form of twists and joggles. The preliminary analysis showed that they can be clearances and dynamic deformation in the kinematic chain, the occurrence of side forces during automatic forging of the forging in a two-component system (a long, thin element), as well as the design and construction errors in the joining of the SMED instrument with the table tops of the press. In order to solve the presented problem, in the first place, a separate dimensional and shape analysis was made of selected elements of the press and the instrumentation with the use of the 3D scanning method with the purpose to analyze the construction tolerances of the key elements of the press geometry. Next, an evaluation of the effect of clearances and dynamic deformations of the press as well as the force distribution during the forging process was made through numerical modelling. Despite all of the above, such an approach did not make it possible to solve the problem. A proprietary method with the use of 3d reverse scanning was proposed, which allowed to solve the problem of forgings errors. Based on the measurement results and analyses for a few variants of production cycles the necessary changes was obtained, making it possible to minimize the errors and obtain proper products in respect of geometry and quality.
ARTICLE | doi:10.20944/preprints201901.0055.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: multi-point die; stretch forming; swinging ball head; numerical simulation
Online: 8 January 2019 (09:09:12 CET)
To improve the effect of multi-point stretch forming of sheet metal, it is proposed in this paper to replace fixed ball head with swinging ball head. According to the multi-point dies with different arrangements, this research establishes the finite element models of the following stretch forming, i.e. fixed ball heads with conventional arrangement, swinging ball heads with conventional arrangement, swinging ball heads with declining staggered arrangement, and swinging ball heads with parallel staggered arrangement and then numerical simulation is performed. The simulation results show that by replacing fixed ball head with swinging ball head, the surface indentation of the formed part was effectively suppressed, the stress and tension strain distribution of the formed part was improved and the forming quality was improved; that the thickness of the elastic pad was reduced, the springback was reduced and the forming accuracy was improved; and that when the ball head was applied to multi-point die with staggered arrangement, better forming result was achieved, where the best forming result was achieved in combining the swinging ball heads with the multi-point die with parallel staggered arrangement. The forming experiments were carried out, and the experimental results were consistent with the trend of numerical simulation results, which verified the correctness of the numerical simulation.
ARTICLE | doi:10.20944/preprints202011.0525.v1
Subject: Engineering, Automotive Engineering Keywords: flexible functional device; thin film coating; slot-die; surface tension; coating gap
Online: 20 November 2020 (07:08:12 CET)
Slot-die coatings are advantageous when used for coating large-area flexible devices; in particular, the coating width can be controlled, and simultaneous multi-layer coatings can be processed. Till date, the effects of ink widening and coating gap on the coating thickness have only been considered in a few studies. To this end, we developed two mathematical models to accurately estimate the coating width and thickness considering these two effects. We used root mean square deviation (RMSD) to experimentally verify the developed method. The coating width was seen to increase and the coating thickness was seen to decrease when the coating gap was increased. Experimental results showed that the estimation performances of the coating width and thickness models were as high as 98.46 % and 95.8 %, respectively. We believe that the developed models can be useful for determining the coating conditions according to the ink properties to coat a functional layer with user-defined widths and thicknesses in both lab- and industrial-scale roll-to-roll slot-die coating processes.
ARTICLE | doi:10.20944/preprints202011.0613.v1
Subject: Engineering, Automotive Engineering Keywords: Green Infrastructure (GI); Human Thermal Comfort (HTC); ENVI-met; microclimate; modelling
Online: 24 November 2020 (10:58:39 CET)
This study assesses Human Thermal Comfort in two selected areas: a Green Infrastructure (GI) area represented by a garden and a high-rise building area, in the Central Business District (CBD) of Melbourne, Australia. Three-dimensional microclimatic modelling software, ENVI-met version 4 was used to simulate the microclimate. The indices of Predicted Mean Vote (PMV), Physiological Equivalent Temperature (PET) and Universal Temperature Climate Index (UTCI) were used to quantify the level of thermal comfort in the research areas. The simulation results showed that at midday, the difference in temperature between the garden area and the high-rise building area was approximately 1°C. Increasing temperatures at midday led to a change in the level of thermal comfort for both the areas, even though it was not significant. In general, the thermal perception in the GI area was slightly ‘cooler’ than in the high-rise building area. The results of the study indicated the important role of GI in improving the thermal comfort in urban areas.
ARTICLE | doi:10.20944/preprints201810.0483.v2
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: continuum rolling contact; geometry relationship; pressure distribution; stress behavior; rolling die and slab
Online: 23 October 2018 (05:51:12 CEST)
In the world industry plant, solid and solid metals are always in contact even their motions not independent. Modeling of rolling die contact with slab primarily needs to describe the Tribology of contact phenomena. Consideration of continuum theory of rolling contact how a contact region is formed between rolling die and slab, and how the tangential force is distributed over the contact area with coefficient of friction is important. The central concern of numerical model is used in this work to indicate a set of equations, derived from the contact principle, that transfer the physical event into the mathematical equations including the laws of nature, such as newton’s laws, boundary conditions, state of stresses and their derivatives at particular time and locations. In this paper the elasticity stress behavior of rolling die contact with slab for number of cyclic loads is modeled. The model is including new proposed constitutive equations for discontinuity of the velocity, pressure distribution in rolling contact from the enter side to exit side of the neutral point. To verify the model, finite element simulation and experimental data from the literature are considered. The results show good agreement with finite element simulation and experimental data.
Subject: Life Sciences, Biotechnology Keywords: Drosophila melanogaster; fluorescence resonance energy transfer; Met-lead 1.44 M1; Pb biosensor
Online: 1 October 2021 (11:12:13 CEST)
The heavy metal lead (Pb) can irreversibly damage the human nervous system. To help understand Pb-induced damage, we applied a genetically encoded Förster resonance energy transfer (FRET)-based Pb biosensor Met-lead 1.44 M1 to two living systems to monitor the concentration of Pb: induced pluripotent stem cell (iPSC)-derived cardiomyocytes as a semi-tissue platform, and Drosophila melanogaster fruit flies as an in vivo animal model. Different FRET imaging modalities were used to obtain FRET signals, which represented the presence of Pb in the tested samples in different spatial dimensions. Using iPSC-derived cardiomyocytes, the relationship between beating activity (20–24 beats per minute, bpm) determined from the fluctuation of fluorescent signals and the concentrations of Pb represented by the FRET emission ratio values of Met-lead 1.44 M1 was revealed from simultaneous measurements. Pb (50 μM) affected the beating activity of cardiomyocytes, whereas two drugs that stop the entry of Pb differentially affected this beating activity: verapamil (2 μM) did not reverse the cessation of beating, whereas 2-APB (50 μM) partially restored this activity (16 bpm). The results clearly demonstrate a potential of this biosensor system as an anti-Pb drug screening application. In the Drosophila model, Pb was detected within the adult brain or larval central nervous system (Cha-gal4>UAS-Met-lead 1.44 M1) using fast epifluorescence and high-resolution two-photon 3D FRET ratio image systems. The tissue-specific expression of Pb biosensors provides an excellent opportunity to explore the possible Pb-specific populations within living organisms. We believe that this integrated Pb biosensor system can be applied to the prevention of Pb poisoning and advanced research on Pb neurotoxicology.
REVIEW | doi:10.20944/preprints202009.0018.v1
Subject: Engineering, Civil Engineering Keywords: green infrastructure; urban heat island; human thermal comfort, modelling tools; ENVI-met.
Online: 1 September 2020 (12:19:13 CEST)
Research on urban heat mitigation has been growing in recent years with many of the studies focusing on green infrastructure (GI) as a strategy to mitigate the adverse effects of Urban Heat Island (UHI). This paper aims at presenting a review of the range of findings from GI research for urban heat mitigation through a review of scientific articles published during the years 2009-2019. This research includes a review of the different types of GI and its contribution for urban heat mitigation and human thermal comfort. In addition to analyzing different mitigation strategies, numerical simulation tools that are commonly used are also reviewed. It is seen that ENVI-met is one of the modelling tools that is considered as a reliable tool to simulate different mitigation strategies and hence has been widely used in the recent past. Considering its popularity in urban microclimate studies, this article also provides a review of ENVI-met simulation results that were reported in the reviewed papers. It was observed that the majority of the research was conducted on a limited spatial scale and focused on temperature and human thermal comfort.
ARTICLE | doi:10.20944/preprints201811.0633.v1
Subject: Engineering, Mechanical Engineering Keywords: micro channel tube (MCT); extrusion; porthole die; microstructure evolution; VPSC model; flow line model
Online: 30 November 2018 (10:43:22 CET)
Micro channel tube (MCT) is widely employed in industry due to its excellent efficiency in heat transfer. An MCT is commonly produced through extrusion within a porthole die, where severe plastic deformation is inevitably involved. Moreover, the plastic deformation, which dramatically affects the final property of the MCT, varies significantly from location to location. In order to understand the development of the microstructure and its effect on the final property of the MCT, the viscoplastic self-consistent (VPSC) model, together with the finite element analysis and the flow line model, is employed in the current study. The flow line model is used to reproduce the local velocity gradient within the complex porthole die, while VPSC model is employed to predict the evolution of the microstructure accordingly. In addition, electron backscatter diffraction (EBSD) measurement and mechanical tests are used to characterize the evolution of the microstructure and the property of the MCT. The simulation results agree well with the corresponding experimental ones. The influence of the material’s flow line on the evolution of the orientation and morphology of the grains, and the property of the produced MCT are discussed in detail.
ARTICLE | doi:10.20944/preprints201810.0353.v1
Subject: Materials Science, Metallurgy Keywords: TRIP steel sheet; cross-die test; forming limit diagram; finite element analysis; failure mechanisms
Online: 16 October 2018 (11:12:42 CEST)
The formability and failure behavior of TRIP steel blanks were investigated through various stress states. The forming limit diagram (FLD) at fracture is constructed both experimentally and numerically. Numerical studies are performed to evaluate the applicability of different damage criteria in predicting the FLD as well as complex cross-die deep drawing process. The fracture surface and numerical results revealed that the material failed in a different mode for different strain path. Therefore, Tresca model which is based on shear stress accurately predicted the conditions where shear had the profound effect on the damage initiation, whereas Situ localized necking criterion was able to calculate the conditions which localization was dominant.
ARTICLE | doi:10.20944/preprints201712.0076.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: additive manufacturing; laser metal deposition; hot stamping; die and mold; conformal cooling; design optimization.
Online: 12 December 2017 (15:24:24 CET)
Hot stamping dies include cooling channels to treat the formed sheet. The optimum cooling channels of dies & molds should adapt to the shape and surface of the dies, so that a homogeneous temperature distribution and cooling are guaranteed. Nevertheless, cooling ducts are conventionally manufactured by deep drilling, attaining straight channels unable to follow the geometry of the tool. Laser Metal Deposition (LMD) is an additive manufacturing technique capable to fabricate nearly free-form integrated cooling channels and therefore shape the so-called conformal cooling. The present work investigates the design and manufacturing of conformal cooling ducts, which are additively built up on hot work steel and then milled in order to attain the final part. Their mechanical performance and heat transfer capability has been evaluated, both experimentally and by means of thermal simulation. Finally, conformal cooling conduits are evaluated and compared to traditional straight channels. The results show that LMD is a proper technology for the generation of cooling ducts, opening the possibility to produce new geometries on dies & molds and, therefore, new products.
HYPOTHESIS | doi:10.20944/preprints202008.0459.v1
Subject: Biology, Animal Sciences & Zoology Keywords: colonial life-history; major evolutionary transition (MET); cooperation; modularity; biological information; heterochrony; tunicate
Online: 20 August 2020 (13:05:33 CEST)
The diversification of life-histories is mediated by cooperation, innovations of biological information, modularity, and heterochrony in developmental processes. These processes are defined, contextualized, and exemplified, studying the evolution of coloniality (i.e. life-history involving modularization of the multicellular individual) in the family of benthic tunicates Styelidae. This study proposes that in these colonial tunicates there is an inter-generational division of labor, where one generation is feeding, a second is developing by morphogenetic processes, and a third is aging by programmed cell death and phagocytosis. The communication system developed in these colonies is mediated, by changes in proportion, location, and gene expression of specialized blood cells. Colonial life-history in animals is related to the reduction of individual size; development of extra-corporeal tissues to interconnect zooids; the inter-generational division of labor; and the reduction of zooid’s individuality. Processes analogous with the widely accepted major evolutionary transitions (METs), suggesting that coloniality could be studied as a MET. The understanding of colonial life-histories could provide information about key mechanisms for life diversification.
ARTICLE | doi:10.20944/preprints202011.0465.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: coating defect; electrolyte layer; temperature; thermal deformation; roll-to-roll slot-die coating systems; wrinkle
Online: 18 November 2020 (10:43:39 CET)
In roll-to-roll (R2R) processing, uniformity of the web is a crucial factor that can guarantee high coating quality. To understand web defects due to thermal deformation, we analyzed the effects of web unevenness on the coating quality of an yttria-stabilized zirconia (YSZ) layer, a brittle electrolyte of solid oxide fuel cells (SOFCs). We used finite element analysis to analyze the thermal and mechanical deformations at different drying temperatures. A YSZ layer was also coated using R2R slot-die coating to observe effects of web unevenness on the coating quality. It was seen that web unevenness was generated by thermal deformation due the conduction and convection heat from the dryer. Owing to varying web unevenness with time, the YSZ layer developed cracks. At higher drying temperatures, more coating defects having larger widths were generated. Results indicated that web unevenness at the coating section led to coating defects, which could damage the SOFC and decrease its yield in the R2R process. From this study, we suggest that coating defects, generated by the web unevenness owing to the convection and conduction heat, should be considered for the high-volume production of brittle electrolytes using the R2R process.
ARTICLE | doi:10.20944/preprints201805.0408.v1
Subject: Earth Sciences, Atmospheric Science Keywords: urban heat island; non-constructible parcels; cool surfaces; urban vegetation; envi met; mitigation measures; beirut
Online: 28 May 2018 (13:21:28 CEST)
The Urban Heat Island (UHI) is one of the more serious consequences of urbanization resulting in impacts on thermal comfort levels, heat stress, and even mortality. For Municipal Beirut, implementation of “cool” surface materials and green spaces have been recommended to counterbalance the UHI. This paper builds on previous findings on the topic of non-constructible parcels within the district of Bachoura in Municipal Beirut and examines the possibility of implementing “cool” surface or paving materials and urban vegetation which can improve thermal conditions especially during the summer period and with the viewto project the positive findings of this case study to the entire Municipal Beirut area. A numerical analysis using ENVI-met 4.0 investigates the thermal performance of these non-constructibles further to implementation of high reflective surfaces and urban vegetation within a broad neighborhood scale in Bachoura. Results show reductions in ambient temperatures up to 1K on a summer day.. Within the framework of an integrated approach to planning, this form of urban acupuncture aims for substantial UHI reduction. Energy performance of buildings further to implementation of these mitigation measures is also recommended for future studies and to validate the findings in this paper.
ARTICLE | doi:10.20944/preprints202208.0069.v1
Subject: Chemistry, Inorganic & Nuclear Chemistry Keywords: technetium; imidazole; technetyl; XRD-analysis; Hirshfeld surface analysis; π-interactions; met-al-nitrogen bond; supramolecular chemistry
Online: 3 August 2022 (03:29:49 CEST)
In this work, we have proposed two new methods for the synthesis of [TcO2L4]+ (where L = im-idazole (Im), methylimidazole (MeIm)) complexes using thiourea (Tu) and Sn(II) as reducing agents. The main and by-products of the reactions were determined, and possible reaction mechanisms were proposed. We have shown that the reduction of Tc(VII) with thiourea is ac-companied by the formation of the Tc(III) intermediate and further oxidation to Tc(V). The reac-tion conditions changing can lead to the formation of Tc(VII) and Tc(IV) salts. Seven new crystal structures are described in this work: Tc(V) complexes, salts with Tc(VII) and Tc(IV) anions. For halide salts of Tu the cell parameters were determined. In all obtained compounds, except for [TcO2(MeIm)4]TcO4, there are π-stacking interactions between aromatic rings. An increase in the anion size lead to weaken intermolecular interactions. Halogen bonds and anion-π interactions have also been found in hexahalide-containing compounds. The Hirshfeld surface analysis showed that the main contribution to the crystal packing is made by van der Waals interactions of the H···H type (42.5–55.1%), H···C/C ···H (17.7–21.3%) and hydrogen bonds, which contribute 15.7–25.3% in total.
ARTICLE | doi:10.20944/preprints202201.0403.v2
Subject: Chemistry, Analytical Chemistry Keywords: lead biosensors; FRET; portable Pb sensor; smartphone-based device; Met-lead; tap water lead; groundwater lead
Online: 23 February 2022 (10:53:14 CET)
Most methods for measuring environmental lead (Pb) content are time consuming, expensive, hazardous, and restricted to specific analytical systems. To provide a facile, safe tool to detect Pb, we created pMet-lead, a portable fluorescence resonance energy transfer (FRET)-based Pb biosensor. pMet-lead comprises a 3D-printed frame housing a 405-nm laser diode — an excitation source for fluorescence emission images (YFP and CFP) — accompanied by optical filters, a customized sample holder with a Met-lead 1.44 M1 (the most recent version)-embedded biochip, and an optical lens aligned for smartphone compatibility. Measuring the emission ratios (Y/C) of the FRET component enables Pb detection with a dynamic range of nearly 2 (1.96), pMet-lead/Pb dissociation constant (Kd) 45.62 nM, and limit of detection 40 nM (0.832 μg/dL, 8.32 ppb). To mitigate earlier problems with lack of selectivity for Pb vs. zinc, we preincubated samples with tricine, a low-affinity zinc chelator. We validated pMet-lead measurements of characterized laboratory samples and unknown samples from six regions in Taiwan by inductively coupled plasma mass spectrometry (ICP-MS). Notably, two unknowns had Y/C ratios significantly higher than that of the control (3.48 ± 0.08 and 3.74 ± 0.12 vs. 2.79 ± 0.02), along with Pb concentrations (10.6 ppb and 15.24 ppb) above the WHO-permitted level of 10 ppb in tap water, while the rest four unknowns showing no detectable Pb upon ICP-MS. These results demonstrate that pMet-lead provides a rapid, sensitive means for on-site Pb detection in water from the environment and in living/drinking supply systems to prevent potential Pb poisoning.
ARTICLE | doi:10.20944/preprints202110.0145.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: immune checkpoint inhibitors; PD-1; PD-L1; CTLA-4; immunotherapy; target therapy; BRAF; MET; melanoma; [18F]FDG PET/CT
Online: 8 October 2021 (14:14:14 CEST)
Background/Aim: To evaluate the association between baseline [18F]FDG-PET/CT tumor burden parameters and disease progression rate after first-line target therapy or immunotherapy in advanced melanoma patients. Materials and Methods: 44 melanoma patients who underwent [18F]FDG-PET/CT before first-line target therapy (28/50) or immunotherapy (16/50) were retrospectively analyzed. Whole-body and per-district metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated. Therapy response was assessed according to RECIST 1.1 on CT scan at 3 (early) and 12 (late) months. PET parameters were compared with Mann-Whitney test. Optimal cut-offs for predicting progression were defined using the ROC curve. PFS and OS were studied using Kaplan-Meier analysis. Results: Median(IQR) MTVwb and TLGwb were 13.1 mL and 72.4 respectively. Non-responders patients were 38/44, 26/28 and 12/16 at early evaluation, and in 33/44, 21/28 and 12/16 at late evaluation in the whole-cohort, target and immunotherapy subgroup respectively. At late evaluation, MTVbone and TLGbone were higher in non-responders compared to responder patients (all p<0.037) in the whole-cohort and target subgroup and also MTVwb and TLGwb (all p<0.022) in target subgroup. No significant differences were found for immunotherapy subgroup. No metabolic parameters were able to predict PFS. Controversy, MTVlfn, TLGlfn, MTVsoft+lfn, TLG-soft+lfn, MTVwb and TLGwb were significantly associated (all p<0.05) with OS in both the whole-cohort and target therapy subgroup. Conclusion: Higher values of whole-body and bone metabolic parameters were correlated with poorer outcome, while higher values of whole-body, lymph node and soft tissue metabolic parameters were correlated with OS.
ARTICLE | doi:10.20944/preprints202210.0475.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: epithelial-to-mesenchymal transition (EMT); hybrid EMT; partial EMT; mesenchymal-to-epithelial transition (MET); SCAND1; SCAN zinc finger; MZF1; cancer prognosis
Online: 31 October 2022 (08:57:38 CET)
Epithelial-mesenchymal transition (EMT) is a reversible cellular program that transiently places epithelial (E) cells into pseudo-mesenchymal (M) cell states. The malignant progression and resistance of many types of carcinomas depends on EMT activation, partial EMT and hybrid E/M status in neoplastic cells. EMT is activated by tumor microenvironmental TGFβ signal and EMT-inducing transcription factors, such as ZEB1/2 in tumor cells. However, reverse EMT factors are less studied. We demonstrate that transcription factor SCAND1 can revert mesenchymal and hybrid E/M phenotype of cancer cells to a more epithelial, less invasive status and inhibit their proliferation and migration. SCAND1 is a SCAN domain-containing protein and hetero-oligomerizes with SCAN-zinc finger transcription factors, such as MZF1, for accessing DNA and transcriptional co-repression of target genes. We found that SCAND1-MZF1 co-expression and interaction correlated with maintaining epithelial features, whereas the simultaneous loss of SCAND1 and MZF1 correlated with mesenchymal features of tumor cells. Overexpression of SCAND1 over endogenous MZF1 in DU-145 prostate cancer cells reverted their hybrid E/M status into cobblestone morphology with increased epithelial adhesion by E-cadherin and β-catenin relocation. Consistently, co-expression analysis in TCGA PanCancer Atlas revealed that both SCAND1 and MZF1 co-express and are negatively correlated with EMT driver genes, including CTNNB1, ZEB1, ZEB2 and TGFBR, in prostate tumor specimens. In addition, SCAND1 overexpression suppressed tumor cell proliferation by reducing the MAP3K-MEK-ERK signaling pathway. Of note, SCAND1-overexpressing DU-145 cells migrated slower than control cells with decreased lymph node metastasis of prostate cancer in a mouse tumor xenograft model. Kaplan-Meyer analysis showed high expression of MZF1 and SCAND1 to correlate with better prognoses in pancreatic cancer and head and neck cancers, although with poorer prognosis in kidney cancer. Overall, these data suggest that the combination of SCAND1-MZF1 complexes may revert the EMT mechanism in cancer to establish an epithelial phenotype. These effects seem to include co-repression of EMT-driver genes and suppression of tumor cell proliferation via inhibition of the MAP3K-MEK-ERK signaling pathway.
Subject: Biology, Anatomy & Morphology Keywords: epithelial mesenchymal plasticity (EMP); epithelial mesenchymal transition (EMT); mesenchymal epithelial transition (MET); E/M Hybrid; partial EMT; computational biology; mathematical modeling; cancer
Online: 10 February 2021 (15:04:19 CET)
The epithelial-mesenchymal (E/M) hybrid state has emerged as an important mediator of elements of cancer progression, facilitated by epithelial mesenchymal plasticity (EMP). We review here evidence for the presence, prognostic significance, and therapeutic potential of the E/M hybrid state in carcinoma. We further assess modelling predictions and validation studies to demonstrate stabilised E/M hybrid states along the spectrum of EMP, as well as computational approaches for characterising and quantifying EMP phenotypes, with particular attention to the emerging realm of single-cell approaches through RNA sequencing and protein-based techniques.