Reduced expression of IQGAP2 and higher expression of IQGAP3 correlates with poor prognosis in cancers

Analysis of extracellular vesicles of frequently used colorectal cancer cell lines

Colorectal cancer (CRC) ranks as the second most prevalent malignancy globally, highlighting the urgent need for more effective diagnostic and therapeutic strategies, as well as a deeper understanding of its molecular basis. Extensive research has demonstrated that cells actively secrete extracellular vesicles (EVs) to mediate intercellular communication at both proximal and distal sites. In this study, we conducted a comprehensive analysis of the RNA content of small extracellular vesicles (sEVs) secreted into the culture media of five frequently utilised CRC cell lines (RKO, HCT116, HCT15, HT29, and DLD1). RNA sequencing data revealed significant insights into the RNA profiles of these sEVs, identifying nine protein-coding genes and fourteen long non-coding RNA (lncRNA) genes that consistently ranked among the top 30 most abundant across all cell lines. Notably, the genes found in sEVs were highly similar among the cell lines, indicating a conserved molecular signature. Several of these genes have been previously documented in the context of cancer biology, while others represent novel discoveries. These findings provide valuable insights into the molecular cargo of sEVs in CRC, potentially unveiling novel biomarkers and therapeutic targets.

PAK6 acts downstream of IQGAP3 to promote contractility in triple negative breast cancer cells

Breast cancer is a heterogeneous disease that remains the most common malignancy among women worldwide. During genomic analysis of breast tumours, mRNA levels of IQGAP3 were found to be upregulated in triple negative tumours. IQGAP3 was subsequently found to be expressed across a panel of triple negative breast cancer (TNBC) cell lines. Depleting expression levels of IQGAP3 delivered elongated cells, disrupted cell migration, and inhibited the ability of cells to form specialised invasive adhesion structures, termed invadopodia. The morphological changes induced by IQGAP3 depletion were found to be dependent on RhoA. Indeed, reduced expression of IQGAP3 disrupted RhoA activity and actomyosin contractility. Interestingly, IQGAP3 was also found to interact with p-21 activated kinase 6 (PAK6); a protein already associated with the regulation of cell morphology. Moreover, PAK6 depletion phenocopied IQGAP3 depletion in these cells. Whereas PAK6 overexpression rescued the IQGAP3 depletion phenotype. Our work points to an important PAK6-IQGAP3-RhoA pathway that drives the cellular contractility of breast cancer cells promoting both cell migration and adhesive invasion of these cells. As this phenotype is relevant to the process of metastasis and re-seeding of metastasis, the pharmacological targeting of PAK6 could lead to clinical benefit in TNBC patients.

IQGAP3 Is an Important Mediator of Skin Inflammatory Diseases

IQGAP3 (IQ Motif Containing GTPase Activating Protein 3) is member of the IQGAP family of scaffold proteins, which are essential for assembling multiprotein complexes that coordinate various intracellular signaling pathways. Previous research has shown that IQGAP3 is overexpressed in psoriatic skin lesions. Given its involvement in processes like cell proliferation and chemokine signaling, we sought to explore its molecular role in driving the psoriatic phenotype of keratinocytes. By conducting transcriptome profiling of HaCaT keratinocytes, we identified numerous psoriasis-associated pathways that were affected when IQGAP3 was knocked down. These included alterations in NFkB signaling, EGFR signaling, activation of p38/MAPK and ERK1/ERK2, lipid metabolism, cytokine production, and the response to inflammatory cytokine stimulation. Real-time analysis further revealed changes in cell growth dynamics, including proliferation and wound healing. The balance between cell proliferation and apoptosis was altered, as were skin barrier functions and the production of IL-6 and IFNγ. Despite these significant findings, the diversity of the alterations observed in the knockdown cells led us to conclude that IQGAP3 may not be the best target for the therapeutic inhibition to normalize the phenotype of keratinocytes in psoriasis.

Navigating the ERK1/2 MAPK Cascade

The RAS-ERK pathway is a fundamental signaling cascade crucial for many biological processes including proliferation, cell cycle control, growth, and survival; common across all cell types. Notably, ERK1/2 are implicated in specific processes in a context-dependent manner as in stem cells and pancreatic β-cells. Alterations in the different components of this cascade result in dysregulation of the effector kinases ERK1/2 which communicate with hundreds of substrates. Aberrant activation of the pathway contributes to a range of disorders, including cancer. This review provides an overview of the structure, activation, regulation, and mutational frequency of the different tiers of the cascade; with a particular focus on ERK1/2. We highlight the importance of scaffold proteins that contribute to kinase localization and coordinate interaction dynamics of the kinases with substrates, activators, and inhibitors. Additionally, we explore innovative therapeutic approaches emphasizing promising avenues in this field.

The Antithetic Roles of IQGAP2 and IQGAP3 in Cancers

The scaffold protein family of IQ motif-containing GTPase-activating proteins (IQGAP1, 2, and 3) share a high degree of homology and comprise six functional domains. IQGAPs bind and regulate the cytoskeleton, interact with MAP kinases and calmodulin, and have GTPase-related activity, as well as a RasGAP domain. Thus, IQGAPs regulate multiple cellular processes and pathways, affecting cell division, growth, cell-cell interactions, migration, and invasion. In the past decade, significant evidence on the function of IQGAPs in signal transduction during carcinogenesis has emerged. Compared with IQGAP1, IQGAP2 and IQGAP3 were less analyzed. In this review, we summarize the different signaling pathways affected by IQGAP2 and IQGAP3, and the antithetic roles of IQGAP2 and IQGAP3 in different types of cancer. IQGAP2 expression is reduced and plays a tumor suppressor role in most solid cancer types, while IQGAP3 is overexpressed and acts as an oncogene. In lymphoma, for example, IQGAPs have partially opposite functions. There is considerable evidence that IQGAPs regulate a multitude of pathways to modulate cancer processes and chemoresistance, but some questions, such as how they trigger this signaling, through which domains, and why they play opposite roles on the same pathways, are still unanswered.

lncRNA MIR4435-2HG Accelerates the Development of Bladder Cancer through Enhancing IQGAP3 and CDCA5 Expression

Background. Bladder cancer (BCa) is one of the most prevalent cancers occurring in the urinary system. Long noncoding RNAs (lncRNAs), in recent years, have emerged as crucial regulators in various biological processes of tumors. Aim. To identify the role of MIR4435-2 host gene (MIR4435-2HG) and uncover its molecular mechanism in BCa. Methods. Firstly, quantitative real-time PCR (RT-qPCR) analysis was used to examine MIR4435-2HG expression in BCa cells. Cell Counting Kit-8 (CCK-8), 5-ethynyl-2 $\prime$ -deoxyuridine (EdU), wound healing, and transwell assays were implemented to identify the role of MIR4435-2HG in BCa. RNA-binding protein immunoprecipitation (RIP), RNA pull down, and luciferase reporter assays were applied to explore the potential mechanism of MIR4435-2HG in BCa. Results. MIR4435-2HG was highly expressed in BCa. Moreover, MIR4435-2HG silencing abrogated BCa cell proliferation, migration, and invasion. In terms of underlying mechanism, MIR44352HG acted as a microRNA-2467-3p (miR-2467-3p) sponge to control the expression of IQ motif containing GTPase activating protein 3 (IQGAP3) and cell division cycle associated 5 (CDCA5), resulting in activation of the rat sarcoma virus (Ras)/rapidly accelerated fibrosarcoma (Raf)/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and PI3K/AKT/mTOR signaling pathways. Conclusion. MIR4435-2HG involves in the progression of BCa, which might provide novel insights for BCa treatment.

Robust group variable screening based on maximum Lq-likelihood estimation

Variable screening plays an important role in ultra-high-dimensional data analysis. Most of the previous analyses have focused on individual predictor screening using marginal correlation or other rank-based techniques. When predictors can be naturally grouped, the structure information should be incorporated while applying variable screening. This study presents a group screening procedure that is based on maximum Lq-likelihood estimation, which is being increasingly used for robust estimation. The proposed method is robust against data contamination, including a heavy-tailed distribution of the response and a mixture of observations from different distributions. The sure screening property is rigorously established. Simulations demonstrate the competitive performance of the proposed method, especially in terms of its robustness against data contamination. Two real data analyses are presented to further illustrate its performance.

IQ Motif-Containing GTPase-Activating Protein 2 Inhibits Breast Cancer Angiogenesis By Suppressing VEGFR2-AKT Signaling

Antiangiogenesis cancer therapies are facing setbacks due to side effects and resistance. Parallel targeting of multiple pathways can help in the development of more effective therapies. This requires the discovery of new molecules that can regulate multiple cellular processes. Our study has recently established the association of reduced IQGAP2 expression in breast cancer with EMT and poor prognosis of the patient. Existing literature indirectly suggests the role of IQGAP2 in angiogenesis that is still unexplored. In this study, we searched the role of IQGAP2 in tumor angiogenesis in a comprehensive manner using cell culture, patients, and animal models. Depletion of IQGAP2 in breast cancer cells increased proliferation, migration, and tubulogenesis of HUVECs. Findings were validated in ex ovo CAM, Matrigel plug and skin wound-healing assays in mouse model, showing that the reduction of IQGAP2 significantly increased angiogenesis. As a confirmation, IHC analysis of the patient's tissues showed a negative correlation of IQGAP2 expression with the microvessel density. Mechanistically, loss of IQGAP2 appeared to activate VEGF-A via ERK activation in tumor cells, which activated the VEGFR2-AKT axis in HUVECs. IMPLICATIONS: The findings of this study suggest the antiangiogenic properties of IQGAP2 in breast cancer. The Dual effect of IQGAP2 on EMT and angiogenesis makes it a potential target for anticancer therapy.

Role of IQGAP1 in Carcinogenesis

Scaffolding proteins can play important roles in cell signaling transduction. IQ motif-containing GTPase-activating protein 1 (IQGAP1) influences many cellular activities by scaffolding multiple key signaling pathways, including ones involved in carcinogenesis. Two decades of studies provide evidence that IQGAP1 plays an essential role in promoting cancer development. IQGAP1 is overexpressed in many types of cancer, and its overexpression in cancer is associated with lower survival of the cancer patient. Here, we provide a comprehensive review of the literature regarding the oncogenic roles of IQGAP1. We start by describing the major cancer-related signaling pathways scaffolded by IQGAP1 and their associated cellular activities. We then describe clinical and molecular evidence for the contribution of IQGAP1 in different types of cancers. In the end, we review recent evidence implicating IQGAP1 in tumor-related immune responses. Given the critical role of IQGAP1 in carcinoma development, anti-tumor therapies targeting IQGAP1 or its associated signaling pathways could be beneficial for patients with many types of cancer.

Identification of Two Novel Candidate Genetic Variants Associated With the Responsiveness to Influenza Vaccination

Background

Annual vaccination is the most effective prevention of influenza infection. Up to now, a series of studies have demonstrated the role of genetic variants in regulating the antibody response to influenza vaccine. However, among the Chinese population, the relationship between genetic factors and the responsiveness to influenza vaccination has not been clarified through genome-wide association study (GWAS).

Method

A total of 1,968 healthy volunteers of Chinese descent were recruited and 1,582 of them were available for the subsequent two-stage analysis. In the discovery stage, according to our inclusion criteria, 123 of 1,582 subjects were selected as group 1 and received whole-genome sequencing to identify potential variants and genes. In the verification stage, 29 candidate variants identified by GWAS were selected for further validation in 481 subjects in group 2. Besides, we also analyzed nine variants from previously published reports in our study.

Results

Multivariate logistic regression analysis showed that compared with the TT genotype of ZBTB46 rs2281929, the TC + CC genotype was associated with a lower risk of low responsiveness to influenza vaccination adjusted for gender and age (Group 2: P = 7.75E-05, OR = 0.466, 95%CI = 0.319–0.680; Combined group: P = 1.18E-06, OR = 0.423, 95%CI = 0.299–0.599). In the combined group, IQGAP2 rs2455230 GC + CC genotype was correlated with a lower risk of low responsiveness to influenza vaccination compared with the GG genotype (P = 8.90E-04, OR = 0.535, 95%CI = 0.370–0.774), but the difference was not statistically significant in group 2 (P = 0.008). The antibody fold rises of subjects with ZBTB46 rs2281929 TT genotype against H1N1, H3N2,and B were all significantly lower than that of subjects with TC + CC genotype (P < 0.001). Compared with IQGAP2 rs2455230 GC + CC carriers, GG carriers had lower antibody fold rises to H1N1 (P = 0.001) and B (P = 0.032). The GG genotype of rs2455230 tended to be correlated with lower antibody fold rises (P = 0.096) against H3N2, but the difference was not statistically significant. No correlation was found between nine SNPs from previously published reports and the serological response to influenza vaccine in our study.

Conclusion

Our study identified two novel candidate missense variants, ZBTB46 rs2281929 and IQGAP2 rs2455230, were associated with the immune response to influenza vaccination among the Chinese population. Identifying these variants will provide more evidence for future research and improve the individualized influenza vaccination program.

IQGAP3, a YAP Target, Is Required for Proper Cell-Cycle Progression and Genome Stability

Controlling cell proliferation is critical for organism development, tissue homeostasis, disease, and regeneration. IQGAP3 has been shown to be required for proper cell proliferation and migration, and is associated to a number of cancers. Moreover, its expression is inversely correlated with the overall survival rate in the majority of cancers. Here, we show that IQGAP3 expression is elevated in cervical cancer and that in these cancers IQGAP3 high expression is correlated with an increased lethality. Furthermore, we demonstrate that IQGAP3 is a target of YAP, a regulator of cell cycle gene expression. IQGAP3 knockdown resulted in an increased percentage of HeLa cells in S phase, delayed progression through mitosis, and caused multipolar spindle formation and consequentially aneuploidy. Protein-protein interaction studies revealed that IQGAP3 interacts with MMS19, which is known in Drosophila to permit, by competitive binding to Xpd, Cdk7 to be fully active as a Cdk-activating kinase (CAK). Notably, IQGAP3 knockdown caused decreased MMS19 protein levels and XPD knockdown partially rescued the reduced proliferation rate upon IQGAP3 knockdown. This suggests that IQGAP3 modulates the cell cycle via the MMS19/XPD/CAK axis. Thus, in addition to governing proliferation and migration, IQGAP3 is a critical regulator of mitotic progression and genome stability. IMPLICATIONS: Our data indicate that, while IQGAP3 inhibition might be initially effective in decreasing cancer cell proliferation, this approach harbors the risk to promote aneuploidy and, therefore, the formation of more aggressive cancers.

IQGAP2 acts as an independent prognostic factor and is related to immunosuppression in DLBCL

Background

Almost one-third of patients with diffuse large B-cell lymphoma (DLBCL) cannot be cured with initial therapy and will eventually succumb to the disease. Further elaboration of prognostic markers of DLBCL will provide therapeutic targets. IQ motif-containing GTPase activating protein 2 (IQGAP2) acts as a tumour suppressor in hepatocellular, prostate, and gastric cancers. However, the role of IQGAP2 in DLBCL remains unclear.

Methods

We collected mRNA expression data from 614 samples and the corresponding clinical information. The survival time of patients was compared between groups according to the mRNA expression level of IQGAP2. Survival analyses were performed in different subgroups when considering the effect of age, tumour stage, serum lactate dehydrogenase (LDH) concentration, performance status, and the number of extra nodal disease sites. The biological processes associated with IQGAP2-associated mRNAs were analysed to predict the function of IQGAP2. The correlation of IQGAP2 mRNA with immunosuppressive genes and leukocyte infiltration were analysed.

Results

The overall survival of patients with increased IQGAP2 mRNA levels was reduced even after aggressive treatment independent of age, tumour stage, serum LDH concentration, performance status, and the number of extra nodal disease sites. Furthermore, the biological processes of IQGAP2-associated mRNAs were mainly immune processes. IQGAP2 mRNA expression was correlated with the expression of immunosuppressive genes and leukocyte infiltration.

Conclusion

IQGAP2 mRNA is an independent prognostic factor and is related to immunosuppression in DLBCL. This discovery may provide a promising target for further development of therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08086-y.

Reduced IQGAP2 expression promotes EMT and inhibits apoptosis by modulating the MEK-ERK and p38 signaling in breast cancer irrespective of ER status

IQGAP2, a member of the IQGAP family, functions as a tumor suppressor in most of the cancers. Unlike IQGAP1 and IQGAP3, which function as oncogenes in breast cancer, the role of IQGAP2 is still unexplored. Here we report a reduced expression of IQGAP2, which was associated with lymph node positivity, lymphovascular invasion, and higher age in breast cancer patients. We found an inverse correlation of IQGAP2 expression levels with oncogenic properties of breast cancer cell lines in estrogen receptor (ER) independent manner. IQGAP2 expression enhanced apoptosis via reactive oxygen species (ROS)-P38-p53 pathway and reduced epithelial-mesenchymal transition (EMT) in a MEK-ERK-dependent manner. IQGAP2-IQGAP1 ratio correlated negatively with phospho-ERK levels in breast cancer patients. Pull-down assay showed interaction of IQGAP1 and IQGAP2. IQGAP2 overexpression rescued, IQGAP1-mediated ERK activation, suggesting the possibility of IQGAP1 sequestration by IQGAP2. IQGAP2 depletion, in a tumor xenograft model, increased tumor volume, tumor weight, and phospho-ERK expression. Overall, our findings suggest that IQGAP2 is negatively associated with proliferative and metastatic abilities of breast cancer cells. Suppression of IQGAP1-mediated ERK activation is a possible route via which IQGAP2 restricts oncogenic properties of breast cancer cells. Our study highlights the candidature of IQGAP2 as a potent target for therapeutic intervention.

Urinary Cell-Free DNA in Bladder Cancer Detection

Urinary bladder cancer is a common urological cancer. Although flexible cystoscopy is widely employed in bladder cancer detection, it is expensive, invasive, and uncomfortable to the patients. Recently, urinary cell-free DNA (ucfDNA) isolated from urine supernatant has been shown to have great potential in bladder cancer detection and surveillance. Molecular features, such as integrity and concentration of ucfDNA, have been shown to be useful for differentiating bladder cancer patients from healthy controls. Besides, bladder cancer also exhibits unique genetic features that can be identified from sequencing and expression of ucfDNA. Apart from bladder cancer detection, ucfDNA is also useful for molecular classification. For example, ucfDNA exhibits significant differences, both molecularly and genetically, in non-muscle-invasive and muscle-invasive bladder cancers. There is no doubt that ucfDNA is a very promising tool for future applications in the field of bladder cancer.

IQGAP3 Overexpression Correlates With Poor Prognosis and Radiation Therapy Resistance in Breast Cancer

Background: IQ motif-containing GTPase activating protein 3 (IQGAP3), the latest identified member of the IQGAP family, may act as a crucial factor in cancer development and progression; however, its clinical value in breast cancer remains unestablished. We explored the correlation between IQGAP3 expression profile and the clinicopathological features in breast cancer. Methods: IQGAP3 mRNA and protein levels were detected in breast cancer cell lines and tumor tissues by real-time PCR and western blotting and compared to the normal control groups. Protein expression of IQGAP3 was also evaluated immunohistochemically in archived paraffin-embedded specimens from 257 breast cancer patients, and the associations between IQGAP3 expression level, clinical characteristics, and prognosis were analyzed. We assessed the relationship between IQGAP3 expression and sensitivity to radiation therapy which was determined by subgroup analysis. Results: IQGAP3 was significantly upregulated in breast cancer cell lines and human tumor tissues at both the mRNA and protein level compared to controls. Additionally, high levels of IQGAP3 expression were detected in 110/257 (42.8%) of archived paraffin-embedded breast cancer specimens. High IQGAP3 expression level was significantly related to clinical stage (p = 0.001), T category (p = 0.002), N category (p = 0.001), locoregional recurrence (p = 0.002), distant metastasis (p = 0.001), and vital status (p = 0.001). Univariate and multivariate statistical analysis showed that IQGAP3 expression was an independent prognostic factor among all 257 breast cancer patients in our cohort (p = 0.003, p = 0.001). Subgroup analysis revealed IQGAP3 expression correlated with radioresistance and was also an independent predictor of radiotherapy outcome. Conclusion: Our findings suggest that high IQGAP3 expression predicts poor prognosis and radioresistance in breast cancer. Therefore, IQGAP3 may be a reliable prognostic biomarker in breast cancer and could be used to identify patients who may benefit from radiotherapy.

IQGAP3 interacts with Rad17 to recruit the Mre11-Rad50-Nbs1 complex and contributes to radioresistance in lung cancer

IQ motif containing GTPase-activating protein 3 (IQGAP3) has been implicated in diverse cellular processes, including neuronal morphogenesis, cell proliferation and motility, and epithelial-mesenchymal transition. However, its role in cancer radioresistance is completely unknown. Here, we report that IQGAP3 is overproduced in lung cancer patients and correlates with poor clinical outcomes. Functionally, we demonstrate that depletion of IQGAP3 impairs oncogenesis and overcomes radioresistance in lung cancer in vitro and in vivo. Mechanistically, we uncover that IQGAP3 interacts with Rad17 and controls its expression to activate the ATM/Chk2 and ATR/Chk1 signaling pathways by recruiting the Mre11-Rad50-Nbs1 (MRN) complex in response to DNA damage. Moreover, Rad17 is identified as the major downstream effector that mediates the functions of IQGAP3 in lung cancer. Clinically, IQGAP3 overexpression positively correlates with Rad17 upregulation in human lung cancer tissues. Collectively, these data support key role for IQGAP3 in promoting lung cancer radioresistance by interacting with Rad17 and suggest that targeting IQGAP3 may be an attractive strategy for lung cancer radiotherapy.

LncRNA PDCD4-AS1 alleviates triple negative breast cancer by increasing expression of IQGAP2 via miR-10b-5p

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Down-regulated expressions of PDCD4-AS1 and IQGAP2were observed in TNBC.

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Over-expressed miR-10b-5p was detected in TNBC.

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PDCD4-AS1/IQGAP2 inhibits proliferation, migration and invasion of TNBC cells.

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miR-10b-5p increases proliferation, migration and invasion of TNBC cells.

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PDCD4-AS1 inhibits TNBC via acting as a ceRNA for miR-10b-5p.

Objective

Mounting evidence demonstrates that long non-coding RNA (lncRNA) is dysregulated in breast cancers. This study was designed to detect the influences and regulatory mechanism of lncRNA PDCD4-AS1 in triple-negative breast cancer (TNBC).

Methods

qRT-PCR and Western blot were utilized to investigate the expression levels of PDCD4-AS1, miR-10b-5p and IQGAP2 in TNBC tissues and cells. Online software and luciferase reporter gene system were employed to testify the interactions among these molecules. Loss and gain of function of PDCD4-AS1, miR-10b-5p or IQGAP2 were performed before MTT and colony formation assay, TUNEL staining in addition to Transwell and scratch assays were applied to measure the cell biological functions.

Results

In this work, PDCD4-AS1 and IQGAP2 were lowly expressed while miR-10b-5p was strongly expressed in TNBC tissues and cells. PDCD4-AS1 or IQGAP2 overexpression effectively attenuated TNBC cell proliferation, migration and invasion, and increased the apoptosis rate, while this effect was abandoned in response to miR-10b-5p mimics transfection. miR-10b-5p bound to IQGAP2 and acted as a downstream target of PDCD4-AS1.

Conclusion

Our findings identified lncRNA PDCD4-AS1 as a tumor suppressor in TNBC by regulating IQGAP2 expression via miR-10b-5p, giving a novel insight into the regulatory mechanism of PDCD4-AS1 in the pathogenesis of TNBC.

Enhancement of Migration and Invasion of Gastric Cancer Cells by IQGAP3

Although gastric cancer is one of the most common causes of cancer death in the world, mechanisms underlying this type of tumor have not been fully understood. In this study, we found that IQGAP3, a member of the IQGAP gene family, was significantly up-regulated in human gastric cancer starting from the early stages of tumor progression. Overexpression of IQGAP3 in 293T and NIH3T3 cells, which have no endogenous IQGAP3 expression, resulted in morphological change with multiple dendritic-like protrusions and enhanced migration. Overexpression of IQGAP3 also led to reduced cell–cell adhesion in 293T cells, likely as a result of its interactions with e-cadherin or β-catenin proteins. Additionally, IQGAP3 accumulated along the leading edge of migrating cells and at the cleavage furrow of dividing cells. In contrast, suppression of IQGAP3 by short-interfering RNA (siRNA) markedly reduced invasion and anchorage-independent growth of MKN1 and TMK-1 gastric cancer cells. We further confirmed that IQGAP3 interacted with Rho family GTPases, and had an important role in cytokinesis. Taken together, we demonstrated that IQGAP3 plays critical roles in migration and invasion of human gastric cancer cells, and regulates cytoskeletal remodeling, cell migration and adhesion. These findings may open a new avenue for the diagnosis and treatment of gastric cancer.

Intronic variant in IQGAP3 associated with hereditary neuropathy with proximal lower dominancy, urinary disturbance, and paroxysmal dry cough

In 2008, we reported a clinically and genetically new type of autosomal dominant disorder of motor and sensory neuropathy with proximal dominancy in the lower extremities, urinary disturbance, and paroxysmal dry cough. To identify the nucleotide variant causative of this disease, we reanalyzed the linkage of the original Japanese pedigree including seven newly ascertained subjects with updated information. We assigned the locus of the disease to 1p13.3-q23 (maximum logarithm-of-odds score = 2.71). Exome sequencing for five patients and one healthy relative from the pedigree revealed 2526 patient-specific single-nucleotide variants (SNVs). By rigorous filtering processes using public databases, our linkage results, and functional prediction, followed by Sanger sequencing of the pedigree and 520 healthy Japanese individuals, we identified an intronic SNV in IQGAP3, a gene known to be associated with neurite outgrowth. Upon pathological examination of the sural nerve, moderate, chronic, mainly axonal neuropathy was observed. By histochemical analyses, we observed a patient-specific increase of IQGAP3 expression in the sural nerve. We concluded that the variant of IQGAP3 is associated with the disease in our pedigree.

IQGAP2 Inhibits Migration and Invasion of Gastric Cancer Cells via Elevating SHIP2 Phosphatase Activity

Previous studies have shown reduced expression of Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) and its tumor-suppressive role in gastric cancer (GC). However, the precise role of SHIP2 in the migration and invasion of GC cells remains unclear. Here, an IQ motif containing the GTPase-activating protein 2 (IQGAP2) as a SHIP2 binding partner, was screened and identified by co-immunoprecipitation and mass spectrometry studies. While IQGAP2 ubiquitously expressed in GC cells, IQGAP2 and SHIP2 co-localized in the cytoplasm of GC cells, and this physical association was confirmed by the binding of IQGAP2 to PRD and SAM domains of SHIP2. The knockdown of either SHIP2 or IQGAP2 promoted cell migration and invasion by inhibiting SHIP2 phosphatase activity, activating Akt and subsequently increasing epithelial–mesenchymal transition (EMT). Furthermore, knockdown of IQGAP2 in SHIP2-overexpressing GC cells reversed the inhibition of cell migration and invasion by SHIP2 induction, which was associated with the suppression of elevated SHIP2 phosphatase activity. Moreover, the deletion of PRD and SAM domains of SHIP2 abrogated the interaction and restored cell migration and invasion. Collectively, these results indicate that IQGAP2 interacts with SHIP2, leading to the increment of SHIP2 phosphatase activity, and thereby inhibiting the migration and invasion of GC cells via the inactivation of Akt and reduction in EMT.

Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis

The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.

Prognostic roles of the expression of sphingosine-1-phosphate metabolism enzymes in non-small cell lung cancer

Background

Sphingosine-1-phosphate (S1P), a bioactive lipid, is generally increased in human non-small cell lung cancer (NSCLC). Evidence has shown that the levels of enzymes in S1P metabolism were associated with clinical outcomes in patients with NSCLC. Nevertheless, the roles of mRNA expression of major enzymes (SPHK1, SPHK2 and SGPL1) in S1P metabolism for predicting outcomes in NSCLC patients have not been determined.

Methods

"The Kaplan-Meier plotter" (the KM plotter) is an online database which contains gene expression and clinical data of 1,928 NSCLC patients. In this study, we analyzed the relationship between mRNA expression of major enzymes in S1P metabolism and overall survival (OS) in 1,926 NSCLC patients with the KM plotter. Further analyses stratified by smoking history, non-metastasis patents, clinical stages, negative surgical margin, chemotherapy and radiotherapy were also performed.

Results

High SPHK1 mRNA expression [hazard ratio (HR) 1.47, 95% confident interval (CI): 1.28-1.68, P=2.6e-08] was significantly correlated to worse OS, but high SPHK2 (0.66, 95% CI: 0.59-0.75, P=1.9e-10) or SGPL1 (HR 0.64, 95% CI: 0.55-0.75, P=8.7e-09) mRNA expression was in favor of better OS in NSCLC patients.

Conclusions

The mRNA expression of SPHK1, SPHK2, and SGPL1 is potential predictor of outcomes in NSCLC patients.

PON1 hypermethylation is associated with progression of renal cell carcinoma

In this study, our aim was to exploring the influences of DNA methylation of PON1 on cell proliferation, migration and apoptosis of renal cancer cells. The genome‐wide methylation array of renal cell carcinoma samples and adjacent tissues were obtained from the cancer genome atlas (TCGA) database. By analysing the DNA methylation and conducting the CpG islands array, methylation status expressed in renal tumour samples and normal renal tissue samples were detected. Methylation‐specific PCR (MS‐PCR) and qRT‐PCR were employed to detect the methylation level and mRNA expression of PON1. Wound‐healing assay, transwell assay and MTT assay were utilized to detecting the migration, invasion and proliferation abilities, respectively. The cell apoptosis was testified by Tunnel assay. In addition, the effect of PON1 on renal cancer cells was verified by experiments in vivo. The methylation status of different genes in renal cell carcinoma samples was obtained by CpG islands arrays and hypermethylated PON1 was selected for further study. PON1 was down‐regulated in renal cell carcinoma tissues detected by qRT‐PCR and Western blot. Both in vitro and vivo experiments indicated that the sunitinib‐resistant in renal cancer cells could be suppressed by treat with 5‐Aza‐dC or TSA, and the effect came out more obvious after 5‐Aza‐dC and TSA co‐treatment. In detail, the demethylation of PON1 inhibited the migration, invasion and proliferation of renal cancer cells and also arrested more cells in G0/G1 phase. The vivo experiment indicated that demethylated PON1 suppressed the growth of tumour. Hypermethylated PON1 promoted migration, invasion and proliferation of sunitinib‐resistance renal cancer cells and arrested more cells in G0/G1 phase.

Clinical value of detecting IQGAP3, B7-H4 and cyclooxygenase-2 in the diagnosis and prognostic evaluation of colorectal cancer

Background

The IQ-motif-containing GTPase-activating protein (IQGAP) family comprises three members, IQGAP1, IQGAP2 and IQGAP3. IQGAP3 is the latest addition to the family. This study mainly investigated the novel marker IQGAP3 at serum and tumor tissue levels compared with the markers B7-H4 and cyclooxygenase-2 (COX-2) in patients with colorectal cancer (CRC) and in healthy individuals, aiming to evaluate the diagnostic and prognostic value of IQGAP3 for CRC.

Materials and methods

Serum samples were collected prior to any therapy in 118 CRC patients and as part of a routine examination in 85 healthy individuals. Serum IQGAP3, B7-H4 and COX-2 levels were measured using commercially available ELISA kits. Immunohistochemistry was performed to detect the IQGAP3, B7-H4 and COX-2 in tumor tissues and normal para-carcinoma tissues. The receiver operating characteristics (ROC) curve and the area under the curve (AUC) were used to evaluate and compare the diagnostic value of different serum tumor markers. Univariate and multivariate analyses were performed to identify the prognostic risk factors for CRC.

Results

IQGAP3, B7-H4 and COX-2 showed low or high expression in tumor tissues while no expression in normal para-carcinoma tissues. Serum levels of IQGAP3 in CRC group were significantly higher than those in healthy control group (P < 0.001). The IQGAP3 AUC was 0.799, while the B7-H4 AUC was 0.795 and the COX-2 AUC was 0.796. IQGAP3 seemed to be superior to B7-H4 and COX-2 in detecting CRC, with the highest sensitivity among the three markers. Multivariate analysis showed that T stage, N stage, differentiation degree, TNM stage and both serum and tissue IQGAP3, B7-H4 and COX-2 levels were significant prognostic factors for CRC.

Conclusions

IQGAP3 has a better diagnostic efficacy than B7-H4 and COX-2 in detecting CRC and it has value in predicting the prognosis of patients with CRC.

Regulators of the RAS-ERK pathway as therapeutic targets in thyroid cancer

Thyroid cancer is mostly an ERK-driven carcinoma, as up to 70% of thyroid carcinomas are caused by mutations that activate the RAS/ERK mitogenic signaling pathway. The incidence of thyroid cancer has been steadily increasing for the last four decades; yet, there is still no effective treatment for advanced thyroid carcinomas. Current research efforts are focused on impairing ERK signaling with small-molecule inhibitors, mainly at the level of BRAF and MEK. However, despite initial promising results in animal models, the clinical success of these inhibitors has been limited by the emergence of tumor resistance and relapse. The RAS/ERK pathway is an extremely complex signaling cascade with multiple points of control, offering many potential therapeutic targets: from the modulatory proteins regulating the activation state of RAS proteins to the scaffolding proteins of the pathway that provide spatial specificity to the signals, and finally, the negative feedbacks and phosphatases responsible for inactivating the pathway. The aim of this review is to give an overview of the biology of RAS/ERK regulators in human cancer highlighting relevant information on thyroid cancer and future areas of research.

DNA methylation of CRB3 is a prognostic biomarker in clear cell renal cell carcinoma

Our previous study revealed that CRB3 protein expression was reduced in clear cell renal cell carcinoma (ccRCC) and was associated with TNM stage, pathological grade, and poor prognosis of ccRCC. This study aimed to investigate if DNA methylation of CRB3 decreases its expression, subsequently leading to the progression and poor prognosis of ccRCC. Data for DNA methylation of CRB3, CRB3 mRNA expression, and ccRCC clinicopathological parameters were extracted from the cancer genome atlas (TCGA) database. The relationships among DNA methylation of CRB3, CRB3 mRNA expression, and ccRCC clinicopathological parameters were analyzed using UALCAN, MethHC, LinkedOmics, and Wanderer. We found that CRB3 mRNA levels were lower in ccRCC compared to normal tissues. Methylation of CRB3 increased in ccRCC, with all probes showing differences between ccRCC and normal tissues. Furthermore, CRB3 DNA methylation negatively correlated with CRB3 mRNA expression. CRB3 DNA methylation was also related to pathologic stage, T stage, N stage, and M stage of ccRCC. Overall survival was shorter in ccRCC patients with high CRB3 DNA methylation compared to ccRCC patients with low CRB3 DNA methylation. Methylation of cg24798010, a CRB3 probe, was related to laterality, pathologic stage, T stage, M stage, neoplasm-histologic-grade without N stage, and race. Furthermore, treatment with the DNA methylation inhibitor Decitabine resulted in the upregulation of CRB3 mRNA in ccRCC cell lines. These results indicate that DNA methylation of CRB3 may be both a prognostic marker and therapeutic target for ccRCC.

A Novel Role of VEGFC in Cerebral Ischemia With Lung Injury

Cerebral ischemia (CI) is a severe brain injury resulting in a variety of motor impairments combined with secondary injury in remote organs, especially the lung. This condition occurs due to insufficient blood supply to the brain during infancy. However, it has a molecular linkage that needs to be thoroughly covered. Here, we report on the role of vascular endothelial growth factor C (VEGFC) in lung injury induced by CI. The middle cerebral artery occlusion (MCAO) was depended to establish the animal model of CI. Rats were used and brain ischemia was confirmed through TTC staining. Serum was used for protein chip analysis to study the proteomic interaction. Immunohistochemistry analyses were used to quantify and locate the VEGFC in the lung and brain. The role of VEGFC was detected by siVEGFC technology in SY5Y, HUCEV, and A549 cell lines, under normal and oxygen glucose deprivation (OGD) conditions in vitro. As a result, the TTC staining demonstrated that the model of brain ischemia was successfully established, and MPO experiments reported that lung damage was induced in MCAO rats. VEGFC levels were up-regulated in serum. On the other hand, immunohistochemistry showed that VEGFC increased significantly in the cytoplasm of neurons, the endothelium of small trachea and the lung cells of CI animals. On a functional level, siVEGFC effectively inhibited the proliferation of SY5Y cells and decreased the viability of HUVEC cells in normal cell lines. But under OGD conditions, siVEGFC decreased the growth of HUVEC and increased the viability of A549 cells, while no effect was noticed on SYSY cells. Therefore, we confirmed the different role of VEGFC played in neurons and lung cells in cerebral ischemia-reperfusion injury. These findings may contribute to the understanding the molecular linkage of brain ischemia and lung injury, which therefore provides a new idea for the therapeutic approach to cerebral ischemia-reperfusion.

Identification of survival-related predictors in hepatocellular carcinoma through integrated genomic, transcriptomic, and proteomic analyses

Patient survival time generally reflects the tumor progression and represents a key clinical parameter. In this study, we aimed to comprehensively characterize the prognosis-associated molecular alterations in hepatocellular carcinoma (HCC). In this study, copy-number changes, gene mutations, mRNA expression, and reverse phase protein arrays data in HCC samples profiled by The Cancer Genome Atlas (TCGA) were obtained. Tumors were then stratified into two groups based on the clinical outcome and identified genomic, transcriptomic, and proteomic traits associated to HCC prognosis. We found that several copy number amplifications and deletions can discriminate HCC patients with poor prognosis from those with better prognosis. Mutated DNAH8 showed a worse prognosis-specific pattern and correlated with a reduced disease-free survival in HCC. By integrating RNA sequencing data, we found that HCC samples with poor prognosis are consistently associated with the up-regulation of cell cycle process, such as chromosome separation, DNA replication, cytokinesis, and etc. At the proteomic level, seven proteins were significantly enriched in samples with poor prognosis, including acetylated α-Tubulin, p62-LCK-ligand, ARID1 A, MSH6, B-Raf, Cyclin B1, and PEA15. Acetylated α-Tubulin was frequently expressed in HCC tissues and acted as a promising prognostic factor for HCC. These alterations lay a foundation for developing relevant therapeutic strategies and improve our knowledge of the pathogenesis of HCC.

Urinary Cell-Free DNA IQGAP3/BMP4 Ratio as a Prognostic Marker for Non-Muscle-Invasive Bladder Cancer

BACKGROUND

Disease monitoring in non-muscle-invasive bladder cancer (NMIBC) patients is crucial for early identification of disease recurrence and progression. High IQGAP3/BMP4 and IQGAP3/FAM107A ratios in urinary cell-free DNA (ucfDNA) are a diagnostic biomarker for bladder cancer. We aimed to investigate whether the levels of these biomarkers in ucfDNA can be used to monitor disease recurrence or progression in patients with NMIBC.

PATIENTS AND METHODS

A total of 103 patients with NMIBC (pTa-pT1) were enrolled. The IQGAP3/BMP4 and IQGAP3/FAM107A ratios in ucfDNA were measured by real-time PCR, and the results were compared with clinical outcome by Kaplan-Meier curves and Cox regression analyses.

RESULTS

Overall, 55 patients (53.4%) experienced recurrence and 29 (28.2%) experienced disease progression during a median follow-up of 42.7 months (range, 6.1-172.2 months). Kaplan-Meier analysis revealed that NMIBC patients with a high IQGAP3/BMP4 ratio had worse recurrence-free survival and progression-free survival (PFS) (P = .001 and < .001, respectively), and those with a high IQGAP3/FAM107A ratio had worse PFS (P = .006). Multivariate Cox regression analysis revealed that the IQGAP3/BMP4 ratio was independently associated with recurrence-free survival (hazard ratio, 2.462; P = .003) and PFS (hazard ratio = 3.871; P = .004), whereas the IQGAP3/FAM107A ratio was not an independent factor for PFS (P = .079).

CONCLUSION

The IQGAP3/BMP4 ratio in ucfDNA might be a valuable novel biomarker for predicting disease recurrence and progression in patients with NMIBC.

Diagnostic value of combined IQGAP3/BMP4 and IQGAP3/FAM107A expression ratios in urinary cell-free DNA for discriminating bladder cancer from hematuria

BACKGROUND

Urinary cell-free DNA (ucfDNA) has great potential as a "liquid biopsy" for use in diagnosis of urological cancers. In this study, we compared ucfDNA gene expression levels between patients with bladder cancer (BC) and those with hematuria, and determined whether they could be used as a noninvasive urine-based marker.

METHODS

The study cohort of 355 patients included a screening group (40 BC and 41 hematuria controls) and a validation cohort (149 BC and 125 hematuria controls). Expression levels ratios of 1 up-regulated gene (IQGAP3) to those of 7 down-regulated genes were examined in ucfDNA in the screening group to identify ratios that differed significantly between BC and hematuria patients. IQGAP3/BMP4 and IQGAP3/FAM107A ratios were selected and combined to develop a discriminant score (DS) index, which was tested in the validation cohort. Receiver operating characteristic curves and areas under the curve were calculated to evaluate the performance of the DS index.

RESULTS

IQGAP3/BMP4 and IQGAP3/FAM107A ratios in ucfDNA were both significantly higher in BC patients than in hematuria patients (both P < 0.001). The DS index had an area under the curve of 0.862, a sensitivity of 71.0%, a specificity of 88.6%, a positive predictive value of 90.3%, and a negative predictive value of 67.2%.

CONCLUSIONS

Both IQGAP3/BMP4 and IQGAP3/FAM107A ratios in ucfDNA were significantly higher in patients with BC than in those with hematuria. The DS index exhibits good diagnostic performance as a noninvasive biomarker.

MUC16 mutation predicts a favorable clinical outcome and correlates decreased Warburg effect in gastric cancer

Mutations in oncogenes or tumor suppressors can reprogram tumor metabolism by controlling multiple metabolic changes including glycolysis, glutaminolysis, increased autophagy, and macropinocytosis. Somatic mutations are essential for the development and growth of gastric cancer (GC), but the precise roles of these mutations in GC glucose metabolism remain largely unknown. In this study, we examined cancer genomes in 375 GC samples and demonstrated several glycolysis-related mutations in GC. Of note, loss-of-function mutation in MUC16 gene was identified. Mutated MUC16 predicted a better prognosis in GC patients. Gene set enrichment analysis suggested that mutated MUC16 status was associated with down-regulation of PI3K/Akt/mTOR signaling and Myc expression. GC cells with MUC16 mutations had reduced glycolytic capacity. Subsequently, genetic silencing of MUC16 in SNU16 and SNU5 cells led to significant reduction in glucose uptake, lactate production, extracellular acidification rate, and colony formation ability, indicating the critical regulatory roles of MUC16 in GC glycolysis and tumorigenesis. Specifically, western blotting showed that MUC16 knockdown inhibited PI3K/Akt/mTOR signaling, and reduced the protein level of Myc, which acts as a key transcription factor in regulating glycolysis. Taken together, our findings identify the MUC16-PI3K/Akt/mTOR-Myc axis as a critical signaling cascade that couples genomic mutations to metabolic reprogramming in GC.

Haploid embryonic stem cells can be enriched and maintained by simple filtration

Mammalian haploid embryonic stem cells (haESCs) serve as a powerful tool for genetic analyses at both the cellular and organismal levels. However, spontaneous diploidization of haESCs limits their use in these analyses. Addition of small molecules to the culture medium to control the cell cycle can slow down diploidization, but cell-sorting methods such as FACS are still required to enrich haploid cells for long-term maintenance in vitro Here, acting on our observation that haploid and diploidized cells differ in diameter, we developed a simplified filtration method to enrich haploid cells from cultured haESCs. We found that regular cell filtration with this system reliably maintained the haploidy of mouse haESCs for over 30 passages. Importantly, CRISPR/Cas9-mediated knockout and knockin were successfully achieved in the filtered cells, leading to stable haploid cell lines carrying the desired gene modifications. Of note, by injecting haESCs into metaphase II oocytes, we efficiently obtained live mice with the expected genetic traits, indicating that regular filtration maintained the functional integrity of haESCs. Moreover, this filtration system was also feasible for derivation of mouse haESCs from parthenogenetic haploid blastocysts and for human haESC maintenance. In conclusion, we have identified a reliable, efficient, and easy-to-handle technique for countering diploidization of haploid cells, a major obstacle in haESC applications.