关键词： copy number amplification   Chr 1q21.1   LINC02802   oncogene   hepatocellular carcinoma  

摘要： Background: Copy number amplification of genomic Chromosome 1q21.1 has emerged as a robust predictor of overall survival in hepatocellular carcinoma (HCC) patients. However, the study of functional long non-coding RNA (lncRNA)s located in 1q21.1 remains unclear. Here, we reported that LINC02802 in Chr 1q21.1 loci exhibit oncogenic roles in HCC patients. Methods: We analyzed the copy-number gains or RNA expression levels of LINC02802 by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in HCC samples. Loss- or gain-of-function assays were carried out to determine the biological effects on cell growth and metastasis in vitro and in vivo. Furthermore, mass spectrometry analysis from biotinylated LINC02802 pulldown assays revealed that IQ motif-containing GTPase-activating protein 1 (IQGAP1) is a prominent binding partner of LINC02802 in HCC cells. Results: The progression of HCC cells is robustly mitigated by LINC02802 knockdown and significantly aggravated by its overexpression. Mechanistically, we found that elevated RNA levels of LINC02802 have directly interacted with the polyproline protein-protein domain, the four IQ motifs domain, and the Ras GTPase-activating protein-related domain of IQGAP1. This interaction stabilizes IQGAP1 by disrupting its interactions with tripartite-motif-containing protein 56 (TRIM56). As a consequence, the ubiquitination-mediated degradation of IQGAP1 is inhibited. Conclusions: LINC02802, an oncogene, has significant potential as a prognostic biomarker, and targeting LINC02802 could provide a promising therapeutic strategy for HCC patients.

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： Breast cancer   LGR5   IQGAP1  

摘要： Breast cancer is a phenomenon in which mammary epithelial cells proliferate out of control under the action of various carcinogenic factors. This study aimed to explore the role and regulatory mechanism of LGR5 in the occurrence and development of breast cancer. Fresh breast cancer case samples and normal breast cell samples were collected. Western blot was used to analyze the expression of LGR5 and (phosphorylated IQGAP1)/(IQGAP1). Construct metastatic human breast cancer MDA-MB-231 cell line knocking down LGR5. The relative expression levels of LGR5 and phosphorylated IQGAP1 were detected by Western blot. The relative activity of the above three types of cells after 24 h of culture was detected by CCK8 assay. The migration ability of the cells was analyzed by the cell scratch test, and the invasive ability of the cells was analyzed by the transwell detection. Construct LGR5-knockdown, LGR5overexpressing and LGR5-& UDelta;C-overexpressing (lack of C-terminal tail) human colon cancer LoVo cell lines. The mechanism of the reaction between LGR5 and IQGAP1 was examined by immunoprecipitation. Expression of LGR5 and phosphorylation ratio of IQGAP1 showed opposite trends in breast cancer and normal body. Viability, migration and invasion ability of breast cancer cells were all affected by LGR5 expression and IQGAP1 phosphorylation ratio. LGR5 affected IQGAP1 phosphorylation process by linking to IQGAP1 through its own C-terminus. This study proved that LGR5, which is highly expressed in breast cancer cells, interacts with IQGAP1 through its C-terminal end, reducing the phosphorylation ratio of IQGAP1, thereby improving the viability, migration and invasion ability of breast cancer cells, and ultimately increasing the malignant transformation rate of breast cancer.

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： breast cancer biomarker   sigma receptor1   breast cancer   oligomerization   IQGAP1   Cdc42   Rac1  

摘要： Simple Summary Breast cancer continues to be the number one cause of cancer mortality among women. Because breast cancer is a heterogenous disease there is a need for a more personalized approach to treatment. Such an approach requires the understanding of the molecular root cause of each cancer and the identification of the responsible molecule(s) or pathway(s). SigmaR1 is a receptor implicated in certain types of breast cancer and represents a promising target for a new generation of personalized treatments. However, there is a need for understanding its precise cellular role in order to target it effectively. This article reviews the current knowledge about SigmaR1 in breast cancer biology and potential treatment and proposes a new model as to how SigmaR1 operates within the cell in order to devise new effective ways for utilizing it in the clinic. Despite the major progress in treating breast cancer, recurrence remains a problem and types such as triple-negative breast cancer still lack targeted medicine. The orphan Sigma receptor1 (SigmaR1) has emerged as a target in breast cancer, but its mechanism of action is unclear and hinders clinical utility. SigmaR1 is widely expressed in organ tissues and localized to various sub-cellular compartments, particularly the endoplasmic reticulum (ER), the mitochondrial-associated membranes (MAMs) and the nuclear envelope. As such, it involves diverse cellular functions, including protein quality control/ER stress, calcium signaling, cholesterol homeostasis, mitochondrial integrity and energy metabolism. Consequently, SigmaR1 has been implicated in a number of cancers and degenerative diseases and thus has been intensively pursued as a therapeutic target. Because SigmaR1 binds a number of structurally unrelated ligands, it presents an excellent context-dependent therapeutic target. Here, we review its role in breast cancer and the current therapies that have been considered based on its known functions. As SigmaR1 is not cla

关键词： TRPA1   IQGAP1   protein trafficking   inflammatory pain   neuropathic pain   calcium signalling  

摘要： Khan et al. study the mechanisms by which TRPA1 channels contribute to mechanical and cold hypersensitivity. They show that the scaffold protein IQGAP1 is an essential part of this process, binding to TRPA1 channels and promoting their trafficking and functional sensitization in sensory neurons. TRPA1 channels have been implicated in mechanical and cold hypersensitivity in chronic pain. But how TRPA1 mediates this process is unclear. Here we show that IQ motif containing GTPase activating protein 1 is responsible using a combination of biochemical, molecular, Ca2+ imaging and behavioural approaches. TRPA1 and IQ motif containing GTPase activating protein 1 bind to each other and are highly colocalized in sensory dorsal root ganglia neurons in mice. The expression of IQ motif containing GTPase activating protein 1 but not TRPA1 is increased in chronic inflammatory and neuropathic pain. However, TRPA1 undergoes increased trafficking to the membrane of dorsal root ganglia neurons catalysed by the small GTPase Cdc42 associated with IQ motif containing GTPase activating protein 1, leading to functional sensitization of the channel. Activation of protein kinase A is also sufficient to evoke TRPA1 trafficking and sensitization. All these responses are, however, completely prevented in the absence of IQ motif containing GTPase activating protein 1. Concordantly, deletion of IQ motif containing GTPase activating protein 1 markedly reduces mechanical and cold hypersensitivity in chronic inflammatory and neuropathic pain in mice. IQ motif containing GTPase activating protein 1 thus promotes chronic pain by coupling the trafficking and signalling machineries to TRPA1 channels.