关键词： AKT   cervical cancer   IQGAP1   MMP16   nasopharyngeal cancer  

摘要： Human papillomavirus (HPV)-related cervical and nasopharyngeal cancers differ in molecular mechanisms underlying the oncogenic processes. The disparity may be attributed to differential expression of oncoproteins. The current study investigated the host oncogenes expression pattern in HPV-associated cervical and nasopharyngeal cancer. Formalin-fixed paraffin-embedded tissues originating from the nasopharyngeal and cervical regions were screened using Hematoxylin and Eosin staining. Genomic DNA and total RNA were extracted from confirmed cancer biopsies and non-cancer tissues (NC). HPV was detected by PCR using MY09/GP5+/6+ primers. Protein expression levels of AKT, IQGAP1, and MMP16 in HPV-infected cancers and controls were determined by immunohistochemistry. RT-qPCR was used to profile mRNAs of the oncogenes. AKT and IQGAP1 proteins were highly expressed in the epithelial cancers compared with the non-cancer tissues (p < 0.05). IQGAP1 and MMP16 mRNAs level was significantly higher in the cancers than in the NC (p < 0.05), but not AKT mRNA levels. MMP16 protein was ubiquitously expressed in all tissues. AKT mRNA level was significantly elevated in CC compared with NPC (p < 0.001). However, the difference in AKT, IQGAP1 and MMP16 proteins level between CC and NPC was not significant (p > 0.05). The oncoproteins expression level between the HPV-positive and HPV-negative cancer biopsies showed no significant difference (p < 0.05). Current study reports AKT but not IQGAP1 and MMP16 mRNAs differentially expression in cervical and nasopharyngeal cancers, independent of HPV infection status.

关键词： IQGAP1   Chemoresistance   Ferroptosis   YAP   Esophageal squamous cell carcinoma  

摘要： Chemoresistance is one of the major hindrances to many cancer therapies, including esophageal squamous cell carcinoma (ESCC). Ferroptosis, a new programmed cell death, plays an essential role in chemoresistance. IQdomain GTPase activating protein 1 (IQGAP1) is a scaffold protein and functions as an oncogene in various human malignancies. However, the underlying effect and molecular mechanisms of IQGAP1 on paclitaxel (PTX) resistance and ferroptosis in ESCC remain to be elucidated. In this study, we found that IQGAP1 was highly expressed in ESCC tissues and could as a potential biomarker for diagnosis and predicting the prognosis of ESCC. Functional studies revealed that IQGAP1 overexpression reduced the sensitivity of ESCC cells to PTX by enhancing ESCC cell viability and proliferation and inhibiting cell death, and protected ESCC cells from ferroptosis, whereas IQGAP1 knockdown exhibited contrary effects. Importantly, reductions of chemosensitivity and ferroptosis caused by IQGAP1 overexpression were reversed with ferroptosis inducer RSL3, while the increases of chemosensitivity and ferroptosis caused by IQGAP1 knockdown were reversed with ferroptosis inhibitor ferrostatin-1 (Fer-1) in ESCC cells, indicating that IQGAP1 played a key role in resistance to PTX through regulating ferroptosis. Mechanistically, we demonstrated that IQGAP1 overexpression upregulated the expression of Yes-associated protein (YAP), the central mediator of the Hippo pathway. YAP inhibitor Verteporfin (VP) could reverse the effects of IQGAP1 overexpression on ESCC chemoresistance and ferroptosis. Taken together, our findings suggest that IQGAP1 promotes chemoresistance by blocking ferroptosis through targeting YAP. IQGAP1 may be a novel therapeutic target for overcoming chemoresistance in ESCC.

关键词： Pancreatic cancer   Phosphoproteomics   Tumor typing   Tumor growth and metastasis   SOX4   MAPK1 kinase   IQGAP1 phosphorylation   KSEA analysis  

摘要： ObjectiveThis study aims to elucidate the functional role of IQGAP1 phosphorylation modification mediated by the SOX4/MAPK1 regulatory axis in developing pancreatic cancer through phosphoproteomics *** and phosphoproteomics data of pancreatic cancer were obtained from the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. Differential analysis, kinase-substrate enrichment analysis (KSEA), and independent prognosis analysis were performed on these datasets. Subtype analysis of pancreatic cancer patients was conducted based on the expression of prognostic-related proteins, and the prognosis of different subtypes was evaluated through prognosis analysis. Differential analysis of proteins in different subtypes was performed to identify differential proteins in the high-risk subtype. Clinical correlation analysis was conducted based on the expression of prognostic-related proteins, pancreatic cancer typing results, and clinical characteristics in the pancreatic cancer proteomics dataset. Functional pathway enrichment analysis was performed using GSEA/GO/KEGG, and most module proteins correlated with pancreatic cancer were selected using WGCNA analysis. In cell experiments, pancreatic cancer cells were grouped, and the expression levels of SOX4, MAPK1, and the phosphorylation level of IQGAP1 were detected by RT-qPCR and Western blot experiments. The effect of SOX4 on MAPK1 promoter transcriptional activity was assessed using a dual-luciferase assay, and the enrichment of SOX4 on the MAPK1 promoter was examined using a ChIP assay. The proliferation, migration, and invasion functions of grouped pancreatic cancer cells were assessed using CCK-8, colony formation, and Transwell assays. In animal experiments, the impact of SOX4 on tumor growth and metastasis through the regulation of MAPK1-IQGAP1 phosphorylation modification was studied by constructing subcutaneous and orthotopic pancreatic cancer xenograft models, as well as a liver metastas

摘要： Acute myeloid leukemia (AML) is fatal in the majority of adults. Identification of new therapeutic targets and their pharmacologic modulators are needed to improve outcomes. Previous studies had shown that immunization of rabbits with normal peripheral WBCs that had been incubated with fluorodinitrobenzene elicited high titer antibodies that bound to a spectrum of human leukemias. We report that proteomic analyses of immunoaffinity-purified lysates of primary AML cells showed enrichment of scaffolding protein IQGAP1. Immunohistochemistry and gene-expression analyses confirmed IQGAP1 mRNA overexpression in various cytogenetic subtypes of primary human AML compared to normal hematopoietic cells. shRNA knockdown of IQGAP1 blocked proliferation and clonogenicity of human leukemia cell-lines. To develop small molecules targeting IQGAP1 we performed in-silico screening of 212,966 compounds, selected 4 hits targeting the IQGAP1-GRD domain, and conducted SAR of the 'fittest hit' to identify UR778Br, a prototypical agent targeting IQGAP1. UR778Br inhibited proliferation, induced apoptosis, resulted in G2/M arrest, and inhibited colony formation by leukemia cell-lines and primary-AML while sparing normal marrow cells. UR778Br exhibited favorable ADME/T profiles and drug-likeness to treat AML. In summary, AML shows response to IQGAP1 inhibition, and UR778Br, identified through in-silico studies, selectively targeted AML cells while sparing normal marrow.

关键词： IQ结构域三磷酸鸟苷酶激活蛋白1   胰腺癌细胞   增殖   凋亡  

摘要： 目的分析下调IQ结构域三磷酸鸟苷酶激活蛋白(IQGAP)1对胰腺癌细胞增殖、凋亡的影响及作用机制。方法人胰腺癌HPAF-Ⅱ细胞分为对照组、过表达组、沉默组。对照组不做任何处理,过表达组为人胰腺癌细胞做IQGAP1过表达质粒转染,沉默组为人胰腺癌细胞做IQGAP1沉默质粒转染。鉴定IQGAP1转染效率,分析沉默IQGAP1基因对胰腺癌细胞的增殖抑制作用、凋亡及Wnt/β-连环蛋白(catenin)通路蛋白的影响,并分析其作用机制。结果过表达组IQGAP1基因表达量显著高于对照组,沉默组IQGAP1基因表达量显著低于对照组(P<0.05),说明IQGAP1基因转染成功。过表达组细胞增殖率显著高于对照组,沉默组细胞增殖率显著低于对照组、过表达组(P<0.05)。过表达组细胞凋亡率显著低于对照组,沉默组细胞凋亡率显著高于对照组、过表达组(P<0.05)。过表达组Wnt、β-catenin蛋白表达量显著低于对照组,细胞外信号调节激酶(ERK)、B细胞淋巴瘤-2相关X蛋白(Bax)、细胞外信号调节激酶的激酶(MEK)蛋白表达量显著高于对照组,沉默组Wnt、β-catenin蛋白表达量显著高于对照组,ERK、Bax、MEK蛋白表达量显著低于对照组(P<0.05);相比于过表达组,沉默组Wnt、β-catenin蛋白表达量显著较高,ERK、Bax、MEK蛋白表达量显著较低(P<0.05)。结论下调IQGAP1基因可以抑制胰腺癌细胞增殖,促进其凋亡,其机制可能与激活Wnt/β-catenin通路相关。

关键词： Biochemistry   Cytoskeleton  

摘要： IQGAP1 coordinates actin assembly via transient pausing of events and by displacing prominent plus-end binding proteins including formin (mDia1), capping protein (CP), and mDia1-CP "decision complexes." Cell processes require precise regulation of actin polymerization that is mediated by plus-end regulatory proteins. Detailed mechanisms that explain plus-end dynamics involve regulators with opposing roles, including factors that enhance assembly, e.g., the formin mDia1, and others that stop growth (capping protein, CP). We explore IQGAP1's roles in regulating actin filament plus-ends and the consequences of perturbing its activity in cells. We confirm that IQGAP1 pauses elongation and interacts with plus ends through two residues (C756 and C781). We directly visualize the dynamic interplay between IQGAP1 and mDia1, revealing that IQGAP1 displaces the formin to influence actin assembly. Using four-color TIRF, we show that IQGAP1's displacement activity extends to formin-CP "decision complexes," promoting end-binding protein turnover at plus-ends. Loss of IQGAP1 or its plus-end activities disrupts morphology and migration, emphasizing its essential role. These results reveal a new role for IQGAP1 in promoting protein turnover on filament ends and provide new insights into how plus-end actin assembly is regulated in cells.

关键词： circAnk3   Glutamate receptors   IQ motif containing GTPase activating protein 1   miR-7080-3p   Psychiatric disorder   Synaptic plasticity  

摘要： BACKGROUND: Circular RNAs are highly enriched in the synapses of the mammalian brain and play important roles in neurological function by acting as molecular sponges of microRNAs. circAnk3 is derived from the 11th intron of the ankyrin-3 gene, Ank3 , a strong genetic risk factor for neuropsychiatric disorders;however, the function of circAnk3 remains elusive. In this study, we investigated the function of circAnk3 and its downstream regulatory network for target genes in the hippocampus of mice. METHODS: The DNA sequence from which circAnk3 is generated was modified using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9) technology, and neurobehavioral tests (anxiety and depression -like behaviors, social behaviors) were performed in circAnk3 + /- mice. A series of molecular and biochemical assays were used to investigate the function of circAnk3 as a microRNA sponge and its downstream regulatory network for target genes. RESULTS: circAnk3 + /- mice exhibited both anxiety -like behaviors and social deficits. circAnk3 was predominantly located in the cytoplasm of neuronal cells and functioned as a miR-7080-3p sponge to regulate the expression of Iqgap1 . Inhibition of miR-7080-3p or restoration of Iqgap1 in the hippocampus ameliorated the behavioral deficits of circAnk3 + /- mice. Furthermore, circAnk3 deficiency decreased the expression of the NMDA receptor subunit GluN2a and impaired the structural plasticity of dendritic synapses in the hippocampus. CONCLUSIONS: Our results reveal an important role of the circAnk3/miR-7080-3p/IQGAP1 axis in maintaining the structural plasticity of hippocampal synapses. circAnk3 might offer new insights into the involvement of circular RNAs in neuropsychiatric disorders.

关键词： IQ motif containing GTPase activating protein (IQGAP1)   knockout mouse   lung fibroblast   alpha-smooth muscle actin (SMA)   scleroderma (systemic sclerosis, SSc)-associated interstitial lung disease (ILD)   bleomycin  

摘要： We previously found IQ motif containing GTPase activating protein (IQGAP1) to be consistently elevated in lung fibroblasts (LF) isolated from patients with scleroderma (systemic sclerosis, SSc)-associated interstitial lung disease (ILD) and reported that IQGAP1 contributed to SSc by regulating expression and organization of alpha-smooth muscle actin (SMA) in LF. The aim of this study was to compare the development of ILD in the presence and absence of IQGAP1. Pulmonary fibrosis was induced in IQGAP1 knockout (KO) and wild-type (WT) mice by a single-intratracheal instillation of bleomycin. Two and three weeks later, mice were euthanized and investigated. We observed that the IQGAP1 KO mouse was characterized by a reduced rate of actin polymerization with reduced accumulation of actin in the lung compared to the WT mouse. After exposure to bleomycin, the IQGAP1 KO mouse demonstrated decreased contractile activity of LF, reduced expression of SMA, TGF beta, and collagen, and lowered overall fibrosis scores compared to the WT mouse. The numbers of inflammatory cells and expression of pro-inflammatory cytokines in lung tissue were not significantly different between IQGAP1 KO and WT mice. We conclude that IQGAP1 plays an important role in the development of lung fibrosis induced by bleomycin, and the absence of IQGAP1 reduces the contractile activity of lung fibroblast and bleomycin-induced pulmonary fibrosis. Thus, IQGAP1 may be a potential target for novel anti-fibrotic therapies for lung fibrosis.