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Acquired resistance to BRAF inhibitor vemurafenib is frequently observed in metastatic colorectal cancer (CRC), and it is a thorny issue that results in treatment failure. As adaptive responses for vemurafenib treatment, a series of cellular bypasses are response for the adaptive feedback reactivation of ERK signaling, which warrant further investigation.We identified ARF1 (ADP-ribosylation factor 1) as a novel regulator of both vemurafenib resistance and cancer metastasis, its molecular mechanism and potential inhibitor were investigated in this study.DIA-based quantitative proteomics and RNA-seq were performed to systematic analyze the profiling of vemurafenib-resistant RKO cells (RKO-VR) and highly invasive RKO cells (RKO-I8), respectively. Co‑immunoprecipitation assay was performed to detect the interaction of ARF1 and IQGAP1 (IQ-domain GTPase activating protein 1). An ELISA-based drug screen system on FDA-approved drug library was established to screen the compounds against the interaction of ARF1-IQGAP1.The biological functions of ARF1 and LY2835219 were determined by transwell, western blotting, Annexin V-FITC/PI staining and in vivo experimental metastasis assays.We found that ARF1 strongly interacted with IQGAP1 to activate ERK signaling in VR and I8 CRC cells. Deletion of IQGAP1 or inactivation of ARF1 (ARF-T48S) restored the invasive ability induced by ARF1. As ARF1-IQGAP1 interaction is essential for ERK activation, we screened LY2835219 as novel inhibitor of ARF1-IQGAP1 interaction, which inactivated ERK signaling and suppressed CRC metastasis and vemurafenib-resistance in vitro and in vivo with no observed side effect. Furthermore, LY2835219 in combined treatment with vemurafenib exerted significantly inhibitory effect on ARF1-mediated cancer metastasis than used independently.This study uncovers that ARF1-IQGAP1 interaction-mediated ERK signaling reactivation is critical for vemurafenib resistance and cancer metastasis, and that LY2835219 is a promising therapeutic agent for CRC both as a single agent and in combination with vemurafenib.

Transcription-induced chimeric RNAs are an emerging area of research into molecular signatures for disease biomarker and therapeutic target development. Despite their importance, little is known for chimeric RNAs-relevant roles and the underlying mechanisms for cancer pathogenesis and progression. Here we describe a unique ASTN2-PAPPA(antisense) chimeric RNA (A-P-as chiRNA) that could be the first reported chimeric RNA derived from the splicing of exons and intron antisense of two neighboring genes, respectively. Aberrant A-P-as chiRNA level in ESCC tissues was associated with tumor progression and patients' outcome. In vitro and in vivo studies demonstrated that A-P-as chiRNA aggravated ESCC metastasis and enhanced stemness through modulating OCT4. Mechanistic studies demonstrated that ERK5-mediated non-canonical PAF1 activity was required for A-P-as chiRNA-induced cancer malignancy. The study defined an undocumented function of chimeric RNAs in aggravating cancer stemness and metastasis.

Previous studies have shown that sharp physical and chemical changes may induce the formation of swirl-like reaction phases in the ultrasonic spot welding (USW) of different materials. However, the mechanisms have not been well understood. In particular, swirl-like structures have seldom been discovered or discussed in the USW of Cu/Sn. In this study, swirl-like phases were observed in the USW of a Sn-coated T2 Cu plate with different welding energies (300−400 J). The evolution of the microstructure from the flat region to the swirl region was studied, the diffusion coefficient of Cu in Sn and the peak temperature of the interface during welding were theoretically calculated and experimentally verified, the formation mechanism of the swirl-like phases was discussed, and the relationship between the joint properties and welding energies was investigated. The results show that the content of Cu3Sn increases, while that of Cu6Sn5 decreases gradually from the flat region to the swirl region and that grain refinement of Cu and IMCs occurs near the swirl regions. The greatly enhanced diffusivity shows that intense atomic diffusion takes place during the welding process. When the welding energy exceeds 300 J, the experimentally measured peak temperatures in the welding processes are higher than the theoretical values. The formation of the swirl-like phase is attributed to the uneven distribution of interfacial stress and the collapse of cavitation bubbles. When the welding energy reaches 400 J, the peak lap shear load of the welded specimen reaches 1008 N, and the associated fractures indicate the combined characteristics of ductility and brittleness.

Aluminum toxicity is common in subtropical acidic soils, and the effect of Al stress on Aleurites montana is unknown. This study determined the growth and Al and macronutrient contents (C, N, P, K, Ca, and Mg) in leaves and roots of 1-year-old A. montana seedings to reveal the effects of Al stress on growth and elements of A. montana seedings and the difference of growth and content of elements in potted seedlings and hydroponic seedlings under Al addition. The content of Al in the leaves of potted A. montana seedlings was greater than 1000 mg kg−1 under Al stress, so it can be judged that A. montana is likely an Al accumulator and has a high Al tolerance in potted soil. The changes of macronutrient contents in the seedlings varied with Al concentration. For potted seedlings, Al stress had a significant effect on Mg and K contents in roots and Mg and C contents in leaves, but it had no effect on other macronutrients, such as N, P and Ca. For hydroponic seedlings, Al content in roots and N, P, and K contents in roots and leaves increased significantly, and C and Ca contents in roots decreased significantly when the Al concentration exceeded 0.290 mmol L−1. The Al stress affected the distribution and transportation of macronutrients between roots and leaves. The Al and K contents in the roots were higher than those in leaves in both cultivation methods, while the C, N, and Ca contents were smaller than those in leaves. The transportation of N, P and Ca from root to leaf in potted seedlings changed with the increase of Al concentration. There were major differences in the growth and the absorption and transportation of elements between potted and hydroponic seedlings under Al stress. In this study, Al promoted or had no significant effect on the growth of potted seedlings, while the growth of hydroponic seedlings was significantly inhibited when the Al concentration was relatively high. Moreover, the effect of Al concentration on Al and macronutrients of potted seedlings was less than that of hydroponic seedlings. Therefore, the effects of the primary environment should be considered in future stress experiments. This study revealed the effect of Al concentration on A. montana seedlings from the perspective of growth and nutrition, which are crucial in ecological restoration function of mixed tree species in acid rain area. Comparison of the effects of Al concentration on A. montana seedlings under two cultivation methods provides new perspectives for future stress test research.

Tumor angiogenesis is a complicated process based upon a sequence of interactions between tumor and vessel endothelial cells. Tumor conditioned medium has been widely used to stimulate endothelial cells in vitro angiogenesis. This work was aimed to investigate the effects of gold nanoparticles (GNPs) on angiogenesis in hepatic carcinoma-conditioned endothelial cells. Human umbilical vein endothelial cells (HUVECs) were cultured with conditioned medium (CM) from the human hepatocarcinoma cell line HepG2 (HepG2-CM), and then treated with different concentrations of GNPs. The effects of GNPs on the viability, migration and active VEGF level of HUVECs were investigated by MTT assay, wound healing assay and transwell chamber assay, and ELISA assay, respectively. The data showed that GNPs significantly inhibited HUVECs proliferation and migration induced by HepG2-CM, and also reduced the levels of active VEGF in the co-culture system. Then, the alterations in morphology and ultrastructure of HUVECs detected by atomic force microscopy (AFM) showed that there appeared obvious pseudopodia, larger membrane particle sizes and much rougher surface in HUVECs after HepG2-CM treatment, which were all reversed after GNPs treatment. Changes in cytoskeleton of HUVECs determined by immunocytochemistry demonstrated that GNPs treatment remarkably inhibited the activation effect of HepG2-CM on HUVECs, which was associated with the disruption of actin filaments induced by GNPs. This study indicates that GNPs can significantly inhibit HepG2-CM activated endothelial cell proliferation and migration through down-regulation of VEGF activity and disruption of cell morphology, revealing the potential applications of GNPs as antiangiogenic agent for the treatment of hepatic carcinoma.

The pathological changes of erythrocytes were detected at the nanometer scale, which was important for revealing the onset of diseases, early diagnosis, and effective therapies. Diseases may disturb the morphology and function of erythrocytes at molecular scale. There were dramatic surface deformations in topography of erythrocytes from a patient with elliptocytosis complicating idiopathic thrombocytopenic purpura (ITP). The overall shape and surface membrane of the healthy, pre- and post-therapeutic erythrocytes have been studied by high-resolution atomic force microscopy imaging. The results showed that we can detect healthy and pathological erythrocytes by the morphologic parameters of the length, width, ratio of length to width, peak, valley, valley-to-peak, surface fluctuation, and standard deviations of the erythrocytes. Therefore, the morphologic information of erythrocytes is very important indictor for diagnosing the healthy and disease, as well as evaluating therapeutic effect.

Atomic force microscopy (AFM) is a rapidly developing tool recently introduced into the evaluation of the age of bloodstains, potentially providing legal medical experts useful information for forensic investigation. In this study, the time-dependent, morphological changes of red blood cells (RBC) under three different conditions (including controlled, room-temperature condition, uncontrolled, outdoor-environmental condition, and controlled, low-temperature condition) were observed by AFM, as well as the cellular viscoelasticity via force-vs-distance curve measurements. Firstly, the data indicate that substrate types have different effects on cellular morphology of RBC. RBC presented the typical biconcave shape on mica, whereas either the biconcave shape or flattened shape was evident on glass. The mean volume of RBCs on mica was significantly larger than that of cells on glass. Surprisingly, the adhesive property of RBC membrane surfaces was substrate type-independent (the adhesive forces were statistically similar on glass and mica). With time lapse, the changes in cell volume and adhesive force of RBC under the controlled room-temperature condition were similar to those under the uncontrolled outdoor-environmental condition. Under the controlled low-temperature condition, however, the changes in cell volume occurred mainly due to the collapse of RBCs, and the curves of adhesive force showed the dramatic alternations in viscoelasticity of RBC. Taken together, the AFM detections on the time-dependent, substrate type-dependent, environment (temperature/humidity)-dependent changes in morphology and surface viscoelasticity of RBC imply a potential application of AFM in forensic medicine or investigations, e.g., estimating age of bloodstain or death time.