关键词： Colorectal cancer   Vemurafenib resistance   Metastasis   LY2835219   ARF1-IQGAP1 interaction  

摘要： Introduction: 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. Objectives: 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. Methods: 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 (IQdomain 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 *** biological functions of ARF1 and LY2835219 were determined by transwell, western blotting, Annexin V-FITC/PI staining and in vivo experimental metastasis assays. Results: 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 Conclusion: This study uncovers that ARF1-IQGAP1 interaction-mediated ERK signaling reactivation is critical for vemurafenib resistance and cancer metastasis, and that

关键词： annular pancreas   cell migration   IQGAP1   malformation   NRCAM  

摘要： Background: Annular pancreas (AP) is a congenital defect of unknown cause in which the pancreas encircles the duodenum. Theories include abnormal migration and rotation of the ventral bud, persistence of ectopic pancreatic tissue, and inappropriate fusion of the ventral and dorsal buds before rotation. The few reported familial cases suggest a genetic ***: We conducted exome sequencing in 115 affected infants from the California birth defects ***: Seven cases had a single heterozygous missense variant in IQGAP1, five of them with CADD scores >20;seven other infants had a single heterozygous missense variant in NRCAM, five of them with CADD scores >20. We also looked at genes previously associated with AP and found two rare heterozygous missense variants, one each in PDX1 and ***: IQGAP1 and NRCAM are crucial in cell polarization and migration. Mutations result in decreased motility which could possibly cause the ventral bud to not migrate normally. To our knowledge, this is the first study reporting a possible association for IQGAP1 and NRCAM with AP. Our findings of rare genetic variants involved in cell migration in 15% of our population raise the possibility that AP may be related to abnormal cell migration.

关键词： ZC3H13   IQGAP1   m6A modification   Papillary thyroid   carcinoma  

摘要： Purpose: The purpose of this study was to clarify the effect of ZC3H13 on the growth of papillary thyroid carcinoma (PTC). Methods: Firstly, we used qRT-PCR and Western blot to compare the difference in the expression of ZC3H13 between normal thyroid epithelial cells and PTC cell lines. Then, ZC3H13 overexpression/knockout thyroid cancer cells were constructed by lentivirus transfection, and the effects of overexpression of ZC3H13 on the proliferation, migration and invasion of PTC cells were detected by CCK8 and transwell experiments. Lastly, MeRIP-qPCR, RIP and o Actinomycin D were used to verify that ZC3H13 regulated the expression of downstream target gene IQGAP1 through m6A modification. Results: ZC3H13 expression was decreased in PTC cell lines BCPAP, KTC-1, k1, HTH83, and TPC1. Proliferation, invasion, and migration of PTC cells were inhibited by overexpressed ZC3H13 but increased by knockdown of ZC3H13. IQGAP1 expression was suppressed by ZC3H13 overexpression but enhanced by ZC3H13 knockdown. In ZC3H13-overexpressed PTC cells, the m6A level of IQGAP1 mRNA was increased, and the IQGAP1 mRNA expression was decreased with the increasing time of Actinomycin D treatment. YTHDF2 enriched more IQGAP1 mRNA than IgG and knockdown of YTHDF2 reversed the effect of ZC3H13 overexpression on IQGAP1 mRNA stability. The xenograft tumor experiment in nude mice confirmed that the overexpression of ZC3H13 inhibited tumor growth, while overexpression of IQGAP1 could reverse the inhibitory effect of ZC3H13 overexpression on tumor growth. Conclusion: ZC3H13 mediates IQGAP1 mRNA degradation by promoting m6A modification of IQGAP1 mRNA, this provides a prospective therapeutic target for PTC. (c) 2023, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://***/licenses/bync-nd/4.0/).

关键词： Cell migration   Focal Adhesion   IQGAP1   Hax1   Microtubules  

摘要： Cell migration is a highly orchestrated process requiring the coordination between the cytoskeleton, cell membrane and extracellular matrix adhesions. Our previous study demonstrated that Hax1 interacts with EB2, a microtubule end-binding protein, and this interaction regulate cell migration in keratinocytes. However, little is known about the underlying regulatory mechanism. Here, we show that Hax1 links dynamic focal adhesions to regulate cell migration via interacting with IQGAP1, a multidomain scaffolding protein, which was identified by affinity purification coupled with LC-MS/MS. Biochemical characterizations revealed that C-terminal region of Hax1 and RGCT domain of IQGAP1 are the most critical binding determinants for its interaction. IQGAP1/Hax1 interaction is essential for cell migration in MCF7 cells. Knockdown of HAX1 not only stabilizes focal adhesions, but also impairs the accumulation of IQGAP in focal adhesions. Further study indicates that this interaction is critical for maintaining efficient focal adhesion turnover. Perturbation of the IQGAP1/Hax1 interaction in vivo using a membrane-permeable TAT-RGCT peptide results in impaired focal adhesion turnover, thus leading to inhibition of directional cell migration. Together, our findings unravel a novel interaction between IQGAP1 and Hax1, suggesting that IQGAP1 association with Hax1 plays a significant role in focal adhesion turnover and directional cell migration.

关键词： Extracellular vesicles   CRISPR/Cas9   liver cancer   sorafenib resistance   cancer stem cells  

摘要： BackgroundSorafenib resistance poses therapeutic challenges in HCC treatment, in which cancer stem cells (CSCs) plays a crucial role. CRISPR/Cas9 can be utilized as a potential technique to overcome the drug resistance. However, a safe, efficient and target specific delivery of this platform remains challenging. Extracellular vesicles (EVs), the active components of cell to cell communication, hold promising benefits as delivery *** Herein we report the normal epithelial cell -derived EVs engineered with HN3(HLC9-EVs) show competing tumor targeting ability. Anchoring HN3 to the membrane of the EVs through LAMP2, drastically increased the specific homing of HLC9-EVs to GPC3(+)Huh-7 cancer cells rather than co-cultured GPC3(-)LO2 cells. Combination therapy of HCC with sorafenib and HLC9-EVs containing sgIF to silence IQGAP1 (protein responsible for reactivation of Akt/PI3K signaling in sorafenib resistance) and FOXM1 (self-renewal transcription factor in CSCs attributed to sorafenib resistance), exhibited effective synergistic anti-cancer effect both in vitro and in vivo. Our results also showed that disruption of IQGAP1/FOXM1 resulted in the reduction of CD133(+) population that contribute to the stemness of liver cancer *** By reversing sorafenib resistance using combination therapeutic approach with engineered EVs encapsulated CRISPR/Cas9 and sorafenib, our study foreshadows a path for a better, accurate, reliable and successful anti-cancer therapy in the future.

关键词： extracellular signal-regulated kinases   intracellular signaling   molecular scaffolds   phosphoinositide 3-kinase  

摘要： IQGAP1 is a multidomain cancer-associated protein that serves as a scaffold protein for multiple signaling pathways. Numerous binding partners have been found for the calpo-nin homology, IQ and GAP-related domains in IQGAP1. Identification of a binding partner for its WW domain has proven elusive, however, even though a cell-penetrating peptide derived from this domain has marked anti-tumor activity. Here, using in vitro binding assays with human proteins and co-precipitation from human cells, we show that the WW domain of human IQGAP1 binds directly to the p110 alpha catalytic subunit of phosphoinositide 3-kinase (PI3K). In contrast, the WW domain does not bind to ERK1/2, MEK1/2, or the p85 alpha regulatory subunit of PI3K when p85 alpha is expressed alone. However, the WW domain is able to bind to the p110 alpha/p85 alpha heterodimer when both subunits are co-expressed, as well as to the mutationally activated p110 alpha/p65 alpha hetero-dimer. We present a model of the structure of the IQGAP1 WW domain, and experimen-tally identify key residues in the hydrophobic core and beta strands of the WW domain that are required for binding to p110 alpha. These findings contribute to a more precise understanding of IQGAP1-mediated scaffolding, and of how IQGAP1-derived therapeutic peptides might inhibit tumorigenesis.

关键词： Osteoporosis   Osteoblast   Higenamine   SMAD family   IQGAP1  

摘要： Osteoporosis is a common bone disease caused by an imbalance of bone resorption and formation that results in a loss of total bone density. SMAD2/3 signal transduction is known to play a crucial role in osteogenic differentiation through transforming growth factor-beta (TGF-beta). By screening a library of small-molecule compounds, the current study identifies higenamine (HG) as an active osteogenic agent that could be a therapeutic candidate for osteoporosis. In vitro data demonstrated that HG effectively induced expressions of osteogenic markers in mouse bone marrow stromal cell (BMSCs) and preosteoblastic cell cultures. Further, HG treatment resulted in enhanced bone formation and prevented accelerated bone loss on two animal models that mimic spontaneous senile osteoporosis and postmenopausal osteoporosis. IQ motif-containing GTPase-activating protein 1 (IQGAP1) was confirmed as a novel target of HG, where HG appears to bind to the Glu-1019 site of IQGAP1 to exert its osteogenic effects. Data subsequently suggested that HG promoted phosphorylation of SMAD2/3 and regulated the SMAD2/3 pathway by inhibiting SMAD4 ubiquitination. Overall, the findings highlight HG as a new small-molecule drug to promote bone formation through SMAD2/3 pathway in osteoporosis. (c) 2023 American Society for Bone and Mineral Research (ASBMR).

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