Ubiquitin ligase TRIM15 promotes the progression of pancreatic cancer via the upregulation of the IGF2BP2-TLR4 axis.

BACKGROUND: The tripartite motif family, predominantly characterized by its E3 ubiquitin ligase activities, is involved in various cellular processes including signal transduction, apoptosis and autophagy, protein quality control, immune regulation, and carcinogenesis. Tripartite Motif Containing 15 (TRIM15) plays an important role in melanoma progression through extracellular signal-regulated kinase activation; however, data on its role in pancreatic tumors remain lacking. We previously demonstrated that TRIM15 targeted lipid synthesis and metabolism in pancreatic cancer; however, other specific regulatory mechanisms remain elusive. METHODS: We used transcriptomics and proteomics, conducted a series of phenotypic experiments, and used a mouse orthotopic transplantation model to study the specific mechanism of TRIM15 in pancreatic cancer in vitro and in vivo. RESULTS: TRIM15 overexpression promoted the progression of pancreatic cancer by upregulating the toll-like receptor 4. The TRIM15 binding protein, IGF2BP2, could combine with TLR4 to inhibit its mRNA degradation. Furthermore, the ubiquitin level of IGF2BP2 was positively correlated with TRIM15. CONCLUSIONS: TRIM15 could ubiquitinate IGF2BP2 to enhance the function of phase separation and the maintenance of mRNA stability of TLR4. TRIM15 is a potential therapeutic target against pancreatic cancer.

Dual passivation effects of ionic liquids enable efficient and stable perovskite solar cells.

In recent years, perovskite solar cells (PSCs) have been attracting more and more attention. Although perovskite materials have high defect tolerance, defects remain the main factor that seriously affects the efficiency and stability of PSCs. Herein, the ionic liquid of 1-butyl, 3-methylimidazolium acetate ([BMIM][ACO]) was introduced into the SnO2/perovskite interface for the first time. Thanks to the dipoles formed by ILs spontaneously, the work function of SnO2 was reduced and the transport ability of carriers was improved as well. Moreover, the Lewis acidity and lone pair electrons of [BMIM][ACO] contribute to the passivation of I- defects, Pb2+ defects, or Pb-I anti site defects. In addition, the presence of dipoles will repel the approach of photogenerated holes and the reverse transport of electrons, reducing the recombination of defect sites through field-effect passivation. The solar cell with efficiency of 19.43% was obtained under such a dual passivation effect, and the best device maintained 75.21% of the initial efficiency after 80 h of continuous illumination.

Stable α-FAPbI3 via porous PbI2 for efficient perovskite solar cells.

Black-phase formamidinium lead iodide (FAPbI3), with a narrow bandgap and high thermal stability, has emerged as an in-demand material for highly efficient perovskite solar cells (PSCs). In a two-step sequential deposition, the PbI2 film plays an important role in the formation of a perovskite film with desirable qualities. This paper explores using N-methyl-2-pyrrolidone (NMP), a strong Lewis base, and N,N-dimethylformamide (DMF) as a mixed precursor solvent (DMF/NMP) of PbI2 and reports on preparing PbI2 films with a porous morphology by thermal treatment. Porous PbI2 films ensure the diffusion and sufficient reaction of the formamidinium iodide solution to form a smooth perovskite film. In addition, a dynamic spin coating method is also introduced to improve the uniformity of the perovskite film. Both methods yield a pure α-phase FAPbI3 film immediately in the unannealed state, which is necessary for the perovskite film to maintain phase stability. Finally, PSCs with a power conversion efficiency of 21.20% (0.13 cm2) are fabricated and optimized. The unencapsulated PSCs retain 90% of the initial efficiency for 1000 hours in dry air and exhibit a good thermal stability when heated to 85 °C.

ITGA2 induces STING expression in pancreatic cancer by inducing DNMT1 degradation.

PURPOSE: Integrin alpha 2 (ITGA2, also known as CD49b or VLA-2) is the alpha subunit of a transmembrane receptor for collagens and related proteins. Previously, we found that ITGA2 may regulate immune cell infiltration in pancreatic cancer by inducing PD-L1 expression. As yet, however, whether ITGA2 regulates immune cell infiltration in pancreatic cancer by other mechanisms remains unclear. METHODS: RNA sequencing was performed to identify differentially expressed genes in ITGA2-silenced pancreatic cancer cells. Protein-protein interactions were detected via co-immunoprecipitation. The infiltration level of immune cells was assessed using an immunofluorescence staining assay. RESULTS: We found that ITGA2 can activate the cytosolic DNA-sensing pathway and promote STING expression in pancreatic cancer cells. In addition, we found that ITGA2 induces DNMT1 degradation by disrupting the interaction between DNMT1 and Kindlin2 in pancreatic cancer cells. As a DNA methyltransferase, we found that DNMT1 overexpression induced by ITGA2 silencing significantly up-regulated the methylation level of the STING gene promoter. Finally, ITGA2 silencing combined with DNMT1 inhibitor treatment induced immune cell infiltration in pancreatic cancer. CONCLUSION: Our data indicate that ITGA2 induces STING expression by interacting with DNMT1 and inducing the degradation of DNMT1. ITGA2 silencing combined with DNMT1 inhibitor treatment may be a novel therapeutic strategy for pancreatic cancer.

CBX3 Regulated By YBX1 Promotes Smoking-induced Pancreatic Cancer Progression via Inhibiting SMURF2 Expression.

As a key reversible and heritable mechanism of transcriptional regulation, the epigenetic modification plays a crucial role in tumorigenesis. Of note, tobacco smoking induces epigenetic modifications to promote pancreatic cancer development. Chromobox protein homolog 3 (CBX3) acts as an epigenetic regulator, modulating gene expression of downstream targets via chromatin modifications. To date, the relationship between CBX3 and smoking in pancreatic cancer remains unknown. This study aimed to uncover the specific role and underlying mechanism of CBX3 in smoking-related pancreatic cancer. The bioinformatics analyses were conducted to identify CBX3 as a key player in tobacco-induced pancreatic cancer. The abnormal upregulation of CBX3 was associated with poor prognosis in pancreatic cancer patients. Moreover, cigarette smoke extract (CSE) exposure promoted the overexpression of Y-box-binding protein 1 (YBX1), which consequently led to upregulated CBX3 in pancreatic cancer cells. We also revealed that CBX3 enhanced pancreatic cancer progression, likely by inhibiting the expression of SMAD specific E3 ubiquitin protein ligase 2 (SMURF2) and promoting the activation of TGF-ß signaling. In summary, the YBX1/CBX3/SMURF2 signaling axis may be a promising therapeutic target in patients with smoking-related pancreatic cancer.

Overexpressed integrin alpha 2 inhibits the activation of the transforming growth factor ß pathway in pancreatic cancer via the TFCP2-SMAD2 axis.

BACKGROUND: Integrin alpha 2 (ITGA2) has been recently reported to be an oncogene and to play crucial roles in tumor cell proliferation, invasion, metastasis, and angiogenesis. Our previous study showed that ITGA2 was overexpressed in pancreatic cancer and promoted its progression. However, the mechanism of ITGA2 overexpression and other mechanisms for promoting the progression of pancreatic cancer are still unclear. METHODS: The GEPIA database was used to confirm the expression of ITGA2 in pancreatic cancer. To verify the influence of ITGA2 and TGF-ß on the morphological changes of pancreatic cancer and tumor cell progression, we conduct CCK8 test, plate cloning, flow cytometry experiments and animal experiments. Then we conduct Western blot, RT-qPCR to explore the relationship between ITGA2 and TGF-ß, and then find the key molecules which can regulate them by immunoprecipitation, Western blot, RT-qPCR, CHIP, nuclear and cytoplasmic separation test. RESULTS: The results of the present study show that the abnormal activation of KRAS induced the overexpression of ITGA2 in pancreatic cancer. Moreover, ITGA2 expression significantly suppressed the activation of the TGF-ß pathway. ITGA2 silencing enhanced the anti-pancreatic cancer proliferation and tumor growth effects of TGF-ß. Mechanistically, ITGA2 expression suppressed the activation of the TGF-ß pathway by inhibiting the SMAD2 expression transcriptionally. In addition, it interacted with and inhibited the nuclear translocation of TFCP2, which induced the SMAD2 expression as a transcription factor. Furthermore, TFCP2 also induced ITGA2 expression as a transcription factor, and the TFCP2 feedback regulated the ITGA2-TFCP2-SMAD2 pathway. CONCLUSIONS: Taken together, these results indicated that ITGA2 expression could inhibit the activation of the TGF-ß signaling pathway in pancreatic cancer via the TFCP2-SMAD2 axis. Therefore, ITGA2, by effectively enhancing the anti-cancer effects of TGF- ß, might be a potential clinical therapeutic target for pancreatic cancer.

Ionic Liquids Modulating CsPbI3 Colloidal Quantum Dots Enable Improved Mobility for High-Performance Solar Cells.

Colloidal all-inorganic CsPbI3 perovskite quantum dots (PQDs) have shown tremendous potential in photovoltaic applications in recent years due to their outstanding optoelectronic properties that general metal halide perovskites offer, along with the added advantages that originates from size reduction and the quantum confinement effect. However, the issue of low carrier mobility in PQD films caused by insulating organic ligands capped on the PQD surface still remains to be addressed while aiming for high-efficiency PQD solar cells. Herein, we propose a novel strategy that takes benefits of ionic liquids, which can offer the high polarity and the electron donating ability to boost the mobility of PQD films in photovoltaic devices. Specifically, 1-propyl-3-methylimidazolium iodide to modulate the colloidal CsPbI3 PQD surface and couple QDs is demonstrated for the first time. The lone pair electrons on the nitrogen of the imidazole ring within the ionic liquid binds to the empty nonbonding surface orbitals of CsPbI3 PQDs while the long-chain insulating ligands are replaced, which enables not only efficient charge transport but also reduced defect density in the assembled PQD solid films. The resulting CsPbI3 PQD solar cell shows a significant increase in efficiency with suppressed hysteresis, indicating the impressive potential of this strategy for developing highly efficient PQD solar cells.

Cu-Ion-Implanted and Polymeric Carbon Nitride-Decorated TiO2 Nanotube Array for Unassisted Photoelectrochemical Water Splitting.

Photoelectrochemical (PEC) water splitting over TiO2 photoanodes is a promising strategy for hydrogen production due to its eco-friendly, energy-saving, and low-cost nature. However, the intrinsic drawbacks of TiO2, i.e., the too wide band gap and rapid exciton recombination, significantly limit further enhancement of its performance. Herein, we report a TiO2 nanotube array (TNA), which is implanted by Cu ions and decorated by polymeric carbon nitride (PCN) nanosheets, as a photoanode for the high-efficiency PEC water splitting. In such designed material, Cu-ion implantation can effectively tailor the electronic structure of TiO2, thus narrowing the band gap and enhancing the electronic conductivity. Meanwhile, the PCN decoration induces TiO2/PCN heterojunctions, enhancing the visible light absorption and accelerating the exciton separation. Upon this synergistic effect, the modified TNA photoanode shows significantly improved PEC capability. Its photocurrent density, solar-to-hydrogen efficiency, and applied bias photon-to-current efficiency achieve 1.89 mA cm-2 at 1.23 VRHE (V vs reversible hydrogen electrode), 2.31%, and 1.20% at 0.46 VRHE, respectively. Importantly, this modified TNA supported on a meshlike Ti substrate can be readily integrated with a perovskite solar cell to realize unassisted PEC water splitting.

Dimensional structure regulation of organic-inorganic hybrid perovskite and its application in thin film transistors.

The effects of dimensional structure on the properties of lead iodide perovskite (C8H9NH3)2(CH3NH3)n-1PbnI3n+1were investigated. Furthermore, perovskite thin films with different dimensionalities were applied as the channel layer of thin film transistors (TFT). The electrical performance and stability of TFT devices were significantly improved through the regulation of dimensional microstructure of the perovskites. As a result, the quasi-2D (n = 6) perovskite TFTs achieved a field-effect mobility (µFE) of 3.90 cm2V-1s-1, with 104on-off current ratio and -1.85 V threshold voltage, which can be maintained well after 4 days without degradation at 30% ambient humidity. Moreover, the electrical performance of the TFTs based on Pure-2D and Quasi-2D perovskite also exhibited a good bias stability.

CH3NH3PbBr3-xIx Quantum Dots Enhance Bulk Crystallization and Interface Charge Transfer for Efficient and Stable Perovskite Solar Cells.

Obtaining a perovskite light-absorbing layer with good crystallization, low defect concentration, good stability, and well-matched energy levels is critical to obtaining high-efficiency perovskite solar cells (PSCs). Here, a hybrid PSC with a graded band gap is explored using MAPbBr3 (MA = CH3NH3) and MAPbBr0.9I2.1 quantum dots (QDs) as component cells. We have creatively designed a solar cell device with a double-QD structure [indium tin oxide (ITO)/SnO2/perovskite:MAPbBr3 QDs/MAPbBr0.9I2.1 QDs/Spiro-OMeTAD/Au]. A better crystal film of the perovskite absorption layer can be obtained because the MAPbBr3 QDs are doped in an antisolvent, which induces nucleation and growth in the polycrystalline perovskite. In addition, we expect that digestive ripening occurred in the crystallization, and the oleic acid ligands on the surface of the QDs disintegrate during the doping process and transfer to the surface of the perovskite absorption layer finally; it follows that the hydrophobicity and stability of the perovskite film are greatly enhanced. Moreover, a thin film of MAPbBr0.9I2.1 QDs is introduced between the perovskite absorption layer and the hole layer, acting as an energy-level ladder, which leads to well-matched energy levels, an increase in fill factor (FF), and an enhanced hole transport capability. In particular, the mechanism of the crystallization process involving the effect of oleic acid ligands on the interior and surface of the perovskite film is fully discussed here. The final research results from the PSCs show that both high efficiency and long-term stability are achieved successfully by this design strategy.

Perovskite Ink with an Ultrawide Processing Window for Efficient and Scalable Perovskite Solar Cells in Ambient Air.

Perovskite solar cells (PSCs) have attracted tremendous attention because of their rapidly growing efficiency and low cost. However, the efficiency of scalably deposited PSCs, especially spray-coated devices, is still lagging far behind that of spin-coated devices because of the complicated crystallization of coated precursor ink. Here, we show a precursor ink with an ultrawide processing window (more than 40 min) for spray-coating by adjusting the precursor component, which benefits the scalable deposition of perovskite films. Coupled with antisolvent extraction and addition of methylamine chloride to perovskite ink, high-quality perovskite films were achieved with large-scale uniformity. A power conversion efficiency (PCE) of 18.5% for rigid sprayed PSCs and 16.15% for flexible sprayed PSCs were achieved. At the square-centimeter level, sprayed PSCs on rigid and flexible substrates were achieved with PCEs of 15.07 and 13.21%, respectively. The one-step single-pass spraying method for versatility substrates at a deposition rate of 540 m h-1 brings great prospects for commercialization of PSCs.

Efficient Perovskite Solar Cells Prepared by Hot Air Blowing to Ultrasonic Spraying in Ambient Air.

Substrate heating is the most common method for controlling crystallization during spray coating. However, due to poor controllability during substrate heating, the sprayed films have variable thicknesses and rich pores, which limit the efficiency of the device. Here, hot air blowing was applied to spray coating to promote the crystallization of perovskite films under ambient conditions. Upon employing a hot air blowing method that stimulated uniformly distributed nuclei growth, the pinhole-free and thickness-controllable perovskite film was prepared. This enabled more reproducible high-quality perovskite films to achieve a power conversion efficiency of 13.5% and obtain a stabilized power output of >12% in ambient conditions.

UV-Sintered Low-Temperature Solution-Processed SnO2 as Robust Electron Transport Layer for Efficient Planar Heterojunction Perovskite Solar Cells.

Recently, low temperature solution-processed tin oxide (SnO2) as a versatile electron transport layer (ETL) for efficient and robust planar heterojunction (PH) perovskite solar cells (PSCs) has attracted particular attention due to its outstanding properties such as high optical transparency, high electron mobility, and suitable band alignment. However, for most of the reported works, an annealing temperature of 180 °C is generally required. This temperature is reluctantly considered to be a low temperature, especially with respect to the flexible application where 180 °C is still too high for the polyethylene terephthalate flexible substrate to bear. In this contribution, low temperature (about 70 °C) UV/ozone treatment was applied to in situ synthesis of SnO2 films deposited on the fluorine-doped tin oxide substrate as ETL. This method is a facile photochemical treatment which is simple to operate and can easily eliminate the organic components. Accordingly, PH PSCs with UV-sintered SnO2 films as ETL were successfully fabricated for the first time. The device exhibited excellent photovoltaic performance as high as 16.21%, which is even higher than the value (11.49%) reported for a counterpart device with solution-processed and high temperature annealed SnO2 films as ETL. These low temperature solution-processed and UV-sintered SnO2 films are suitable for the low-cost, large yield solution process on a flexible substrate for optoelectronic devices.

Enhanced planar perovskite solar cells with efficiency exceeding 16% via reducing the oxygen vacancy defect state in titanium oxide electrode.

In this work, the influence of oxygen vacancy defect (OVD) in compact titanium oxide (c-TiO2) on the performance of planar perovskite solar cells (p-PSCs) is investigated, and the possible mechanisms are also proposed. To meet our objective, anatase c-TiO2 thin films with various OVD concentrations are prepared by changing the oxygen flux during the DC magnetron sputtering process and are characterized by the intensity of defect signals in the X-ray photoelectron spectra. We conclude that abundant OVDs can trigger an obviously increased majority carrier accumulation zone at the metal oxide/perovskite interface and enhanced capacitance, thereby greatly deteriorating photogenerated carrier collection efficiency. A detailed analysis of the study results also reveals that the presence of OVD in the bulk and surface of c-TiO2 can slow down electronic carrier transport and lower its electron quasi-Fermi level under illumination, leading to the detrimental charge recombination in p-PSCs. Furthermore, we report a remarkably enhanced p-PSC efficiency via preparing c-TiO2 using high oxygen flux and subsequent ultraviolet ozone treatment. As a consequence, repeatable power conversion efficiency (PCE) is propelled to as high as 16.62%, coupled with negligible hysteresis and increased stability. These results provide a significant implication for further perfecting efficient and stable p-PSCs for their record efficiency.

Improving Performance of Organic-Silicon Heterojunction Solar Cells Based on Textured Surface via Acid Processing.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PEDOT: PSS) is widely applied in organic-photoelectronic devices due to its excellent transparency and conductivity. However, when it is used in the organic-silicon heterojunction solar cells with traditional pyramid texturing surface, the device performance is limited by the contact between the PEDOT: PSS and silicon wafer at the bottom of the pyramids. We optimized the structure of the bottom of the pyramids via acid isotropic etching (AIE) method with mixed acid solution to ensure that the silicon wafer is fully covered by the PEDOT: PSS. In addition, hydrogenated amorphous silicon thin films were deposited with PEVCD method as the passivation and back surface field (BSF) layer to decrease the rear surface recombination rate, thus increasing the long wavelength response. Finally, a power conversion efficiency of 13.78% was achieved after depositing MoO3 on the front of the device as the antireflection layer.

Novel Combination of Efficient Perovskite Solar Cells with Low Temperature Processed Compact TiO2 Layer via Anodic Oxidation.

In this work, a facile and low temperature processed anodic oxidation approach is proposed for fabricating compact and homogeneous titanium dioxide film (AO-TiO2). In order to realize morphology and thickness control of AO-TiO2, the theory concerning anodic oxidation (AO) is unveiled and the influence of relevant parameters during the process of AO such as electrolyte ingredient and oxidation voltage on AO-TiO2 formation is observed as well. Meanwhile, we demonstrate that the planar perovskite solar cells (p-PSCs) fabricated in ambient air and utilizing optimized AO-TiO2 as electron transport layer (ETL) can deliver repeatable power conversion efficiency (PCE) over 13%, which possess superior open-circuit voltage (Voc) and higher fill factor (FF) compared to its counterpart utilizing conventional high temperature processed compact TiO2 (c-TiO2) as ETL. Through a further comparative study, it is indicated that the improvement of device performance should be attributed to more effective electron collection from perovskite layer to AO-TiO2 and the decrease of device series resistance. Furthermore, hysteresis effect about current density-voltage (J-V) curves in TiO2-based p-PSCs is also unveiled.

Toward Revealing the Critical Role of Perovskite Coverage in Highly Efficient Electron-Transport Layer-Free Perovskite Solar Cells: An Energy Band and Equivalent Circuit Model Perspective.

Currently, most efficient perovskite solar cells (PVKSCs) with a p-i-n structure require simultaneously electron transport layers (ETLs) and hole transport layers (HTLs) to help collecting photogenerated electrons and holes for obtaining high performance. ETL free planar PVKSC is a relatively new and simple structured solar cell that gets rid of the complex and high temperature required ETL (such as compact and mesoporous TiO2). Here, we demonstrate the critical role of high coverage of perovskite in efficient ETL free PVKSCs from an energy band and equivalent circuit model perspective. From an electrical point of view, we confirmed that the low coverage of perovskite does cause localized short circuit of the device. With coverage optimization, a planar p-i-n(++) device with a power conversion efficiency of over 11% was achieved, implying that the ETL layer may not be necessary for an efficient device as long as the perovskite coverage is approaching 100%.