Cbl‑associated protein (CAP) is encoded by the sorbin and SH3 domain‑containing 1 (SORBS1) gene. CAP has been reported to be associated with the actin cytoskeleton, receptor tyrosine kinase signaling ...and cell adhesion through interactions with various proteins. It may be hypothesized that SORBS1 has numerous unknown functions, which may include providing a favorable condition for metastasis. Although CAP has been demonstrated to possess a number of functions, the role of this protein has only been reported in metabolic signaling pathways and its function in cancer remains to be elucidated. In the present study, SORBS1 expression was detected in colorectal cancer cell lines divided into the primary group and the metastatic group by reverse transcription‑quantitative PCR and western blot analysis. In addition, SORBS1 expression was manipulated by vector transfection and lentivirus transduction. The metastatic role of SORBS1, as determined by assessing its effects on cell proliferation and migration, was determined by colony formation assay, cell cycle analysis and Boyden chamber assay. To elucidate the SORBS1‑binding protein, immunoprecipitation was performed. Co‑localization of SORBS1 and AHNAK nucleoprotein (AHNAK) was identified by confocal microscopy. Notably, the protein expression levels of CAP were higher in SNU‑769A and SW480 cells than in SNU‑769B and SW620 cells. In addition, the number of colonies in the SORBS1‑overexpressing group was significantly increased compared with that of the control group, as determined using the colony formation assay; the SORBS1 overexpression group formed >8‑fold more colonies than the control group. The proliferative ability of the SORBS1 overexpression group was also significantly increased compared with the control group over the entire incubation period. Cell migration assays revealed that the number of migrated SORBS1‑knockdown cells was reduced compared with the control in both HCT‑116 and SNU‑C4 cell lines; migration area was decreased to 31 and 26% in HCT‑116 and SNU‑C4 cell lines, respectively. Consequently, it was confirmed that SORBS1 could form a complex with AHNAK, which functions as a tumor suppressor through inhibition of phosphorylated‑ERK and Rho‑associated coiled‑coil containing protein kinase 1. In conclusion, SORBS1 may serve a crucial role in cancer growth and migration via inhibition of AHNAK expression.
In additive manufacturing (AM), the powder properties and laser powder bed fusion (LPBF) process parameters influence the quality of materials and building parts. However, the relationship between ...the size of the powder, LPBF process parameters, and mechanical properties is not well-established. In addition, Hastelloy X (HX) is attracting attention for its excellent high-temperature properties, but it is difficult to process, such as by cutting and milling, because of its high hardness and high ductility. This can be overcome by applying the AM process. We compared the LPBF window process maps for two HX powders of different sizes. Despite their small difference of 19.7% in particle size, it was confirmed that the difference in laser power was more than 40 W, the difference in scan speed was more than 100 mm/s, and the difference in energy density was more than 20% under the optimal process conditions. The as-built specimen had a larger molten-pool size as the energy density was higher, which resulted in the differences in mechanical properties at room temperature and high temperature (816 °C). We considered the control of the size of the powder to obtain the properties required for each temperature condition. The microstructures and mechanical properties of the as-built LPBF specimens were also investigated and compared with those of cast HX. Because of the rapid melting and solidification processes in LPBF, the as-built HX exhibited nano-sized dendrite structures and large internal strain energy. This resulted in the as-built LPBF exhibiting a higher room-temperature tensile strength than the cast material. Under high-temperature conditions, the grain boundary of the as-built LPBF acts as a sliding path, and the as-built LPBF HX showed significantly better high-temperature tensile strength characteristics than the cast HX.
Although MEK blockade has been highlighted as a promising antitumor drug, it has poor clinical efficacy in KRAS mutant colorectal cancer (CRC). Several feedback systems have been described in which ...inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single‐MEK targeted therapies. Here, we investigated a bypass mechanism of resistance to MEK inhibition in KRAS CRC. We found that KRAS mutant CRC cells with refametinib, MEK inhibitor, induced MIF secretion and resulted in activation of STAT3 and MAPK. MIF knockdown by siRNA restored sensitivity to refametinib in KRAS mutant cells. In addition, combination with refametinib and 4‐IPP, a MIF inhibitor, effectively reduced the activity of STAT3 and MAPK, more than single‐agent treatment. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against refametinib‐resistant cells by inhibition of MIF activation. These results reveal that MIF‐induced STAT3 and MAPK activation evoked an intrinsic resistance to refametinib. Our results provide the basis for a rational combination strategy against KRAS mutant colorectal cancers, predicated on the understanding of cross talk between the MEK and MIF pathways.
Although drug resistance to MEK inhibitor has been researched, the mechanism of resistance remains unclear. We found that macrophage inhibitory factor (MIF) was associated with drug resistance in KRAS mutant colorectal cancer cell lines. The results suggest suppression of MIF and MEK as a promising combination strategy against KRAS mutant colorectal cancers.
This study was designed to identify novel fusion transcripts (FTs) and their functional significance in colorectal cancer (CRC) lines.
We performed paired-end RNA sequencing of 28 CRC cell lines. FT ...candidates were identified using TopHat-fusion, ChimeraScan, and FusionMap tools and further experimental validation was conducted through reverse transcription-polymerase chain reaction and Sanger sequencing. FT was depleted in human CRC line and the effects on cell proliferation, cell migration, and cell invasion were analyzed.
One thousand three hundred eighty FT candidates were detected through bioinformatics filtering. We selected six candidate FTs, including four inter-chromosomal and two intrachromosomal FTs and each FT was found in at least one of the 28 cell lines. Moreover, when we tested 19 pairs of CRC tumor and adjacent normal tissue samples, NFATC3-PLA2G15 FT was found in two. Knockdown of NFATC3-PLA2G15 using siRNA reduced mRNA expression of epithelial-mesenchymal transition (EMT) markers such as vimentin, twist, and fibronectin and increased mesenchymal-epithelial transition markers of E-cadherin, claudin-1, and FOXC2 in colo-320 cell line harboring NFATC3-PLA2G15 FT. The NFATC3-PLA2G15 knockdown also inhibited invasion, colony formation capacity, and cell proliferation.
These results suggest that that NFATC3-PLA2G15 FTs may contribute to tumor progression by enhancing invasion by EMT and proliferation.
•Subsequent alloying process following the liquid metal dealloying is proposed.•The immersion in Mg–3Al melt facilitates Al alloying to 3D interconnected porous Ti.•Al alloying leads to formation of ...3D interconnected metal–intermetallic composites.•Mg–Ti3Al–TiAl composite has remarkable hardness, strength, and fracture resistance.
This study presents a novel process for the fabrication of metal–intermetallic composites with a 3D bicontinuous structure, achieved through a combination of liquid metal dealloying (LMD) and subsequent alloying. Initially, porous Ti structures are produced using the LMD process, followed by immersion in a molten Mg–3Al (wt%) metal. Due to the higher thermodynamic miscibility of Al with Ti compared to Mg, the concentration of Al in the Ti matrix increases as the immersion time increases. This results in a sequential phase transition within the Ti matrix: α-Ti → Ti3Al → TiAl. The phase transition considerably affects the hardness and strength of the composite material, with the Mg–Ti3Al–TiAl composite exhibiting a maximum hardness nearly twice as high as that of the conventional Mg–Ti composite. This innovative process holds potential for the development of various bicontinuous metal–intermetallic composites.
Abstract Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment ...for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans) . Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups ( p > 0.05), and the flexural strength was lower in the experimental groups than in the control group ( p < 0.05), but no difference was found with Sr-PBG content ( p > 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group ( p < 0.05). This study demonstrated that 3.75% Sr-PBG exhibits antifungal effects against C. albicans along with suitable physicochemical properties, which may help to minimize the risk of adverse effects associated with harmful microbial living on removable orthodontic appliances and promote the use of various materials.
Among the many experimental paradigms used for the investigation of aging, the calorie restriction (CR) model has been proven to be the most useful in gerontological research. Exploration of the ...mechanisms underlying CR has produced a wealth of data. To identify key molecules controlled by aging and CR, we integrated data from 84 mouse and rat cDNA microarrays with a protein–protein interaction network. On the basis of this integrative analysis, we selected three genes that are upregulated in aging but downregulated by CR and two genes that are downregulated in aging but upregulated by CR. One of these key molecules is lymphocyte-specific protein tyrosine kinase (LCK). To further confirm this result on LCK, we performed a series of experiments in vitro and in vivo using kidneys obtained from aged ad libitum-fed and CR rats. Our major significant findings are as follows: (1) identification of LCK as a key molecule using integrative analysis; (2) confirmation that the age-related increase in LCK was modulated by CR and that protein tyrosine kinase activity was decreased using a LCK-specific inhibitor; and (3) upregulation of LCK leads to NF-κB activation in a ONOO
−
generation-dependent manner, which is modulated by CR. These results indicate that LCK could be considered a target attenuated by the anti-aging effects of CR. Integrative analysis of cDNA microarray and interactome data are powerful tools for identifying target molecules that are involved in the aging process and modulated by CR.
Journaling file systems are widely used in modern computer systems as it provides high reliability with reasonable performance. However, existing journaling file systems are not efficient for ...emerging PCM (Phase Change Memory) storage. Specifically, a large amount of write operations performed by journaling incur serious performance degradation of PCM storage as it has long write latency. In this paper, we present a new journaling file system for PCM, called Shortcut-JFS, that reduces write amount of journaling by more than a half exploiting the byte-accessibility of PCM. Specifically, Shortcut-JFS performs two novel schemes, 1) differential logging that performs journaling only for modified bytes and 2) in-place checkpointing that removes unnecessary block copy overhead. We implemented Shortcut-JFS on Linux 2.6, and measured the performance of Shortcut-JFS and legacy journaling schemes used in ext 3. The results show that the performance improvement of Shortcut-JFS against ext 3 is 40% on average.
DTFS Lee, Eunji; Jang, Jee-eun; Bahn, Hyokyung
Proceedings of the 29th Annual ACM Symposium on Applied Computing,
03/2014
Conference Proceeding
Phase-change memory (PCM) has emerged as one of the most promising technologies to incorporate into the storage hierarchy of future computer systems. However, PCM has critical weaknesses in ...performing write operations. Specifically, the access latency and the energy consumption that occur during a write operation are about 6--10 times larger than those of a read operation in PCM. To cope with this situation, we analyze the write access characteristics of file systems, and observe that a large percentage of file write I/Os incurs small changes from the previous version. Based on this observation, we design a novel file system for PCM called DTFS (dual-tree file system) that incurs minimal writes to PCM. DTFS performs better than legacy file systems, but its reliability is as high as any file systems based on journaling or copy-on-write. Experiments with various workload conditions show that DTFS improves the file system performance and the energy consumption by 47% and 67% on average, respectively, compared to copy-on-write file systems such as ZFS and BtrFS.
Abstract
The tumor microenvironment is recognized as developing crosstalk between different cells by secretion of growth factors and cytokines, thus providing oncogenic signals enhancing tumor ...progression and drug resistance. Here, we hypothesized that tumor cells carrying KRAS mutation-induced cytokines may have a critical role in intercellular communication between microenvironment and tumor cells. We first investigated biologic evidence of secreted cytokines in KRAS mutant type (KRAS MT) cell lines. We explored the roles of cytokine that cell morphology, colony-formation ability, and wound-healing ability were enhanced when KRAS wild-type (KRAS WT) cell lines were exposed to conditioned media (CM) from KRAS MT cells, and we found macrophage migration inhibitory factor (MIF) was highly expressed in KRAS MT cells by analysis of proteomics. We also observed secreted MIF level between KRAS WT and MT cell lines, and it was highly secreted in KRAS MT cell lines. In addition, compared with patients whose KRAS mutation was not harbored, MIF expression was higher in patients who have KRAS mutation. The predictive marker of KRAS mutation in colorectal cancer patients is associated with resistance to antiepidermal growth factor receptor (EGFR) antibody cetuximab. Following the hypothesis, we investigated that secreted cytokines have an effect on the cetuximab resistance to surrounding cells including KRAS WT cells. Treatment of CM from KRAS MT cells led to cetuximab resistance in KRAS WT cells and MIF blockade prevented cetuximab resistance. Also, CM from knockout in KRAS MT cells by using CRISPR/Cas9 system resulted in sensitizing to cetuximab resistance compared with CM from KRAS MT cells. In conclusion, we demonstrated for the first time that MIF promotes the cetuximab resistance of KRAS WT colorectal cancer cells, and this effect is mediated by paracrine and autocrine signaling-induced activation of the intracellular AKT signaling pathways and regulated by NF-kb transcription factor through oncogenic KRAS mutation and MIF overexpression, respectively. These findings suggest that MIF may be a promising predictive biomarker for the cetuximab resistance of KRAS wild-type colorectal cancer patients.
Citation Format: Jee Eun Jang, Hwang-Phill Kim, Sae Won Han, Tae You Kim. Mutant KRAS-induced macrophage migration inhibitory factor (MIF) secretion promotes resistance to cetuximab in colorectal cancer abstract. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B100.
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