Expression of DIAPH1 is up-regulated in colorectal cancer and its down-regulation strongly reduces the metastatic capacity of colon carcinoma cells

Comprehensive serum proteomics profiles and potential protein biomarkers for the early detection of advanced adenoma and colorectal cancer

BACKGROUND

The majority of colorectal cancer (CRC) cases develop from precursor advanced adenoma (AA). With the development of proteomics technologies, blood protein biomarkers have potential applications in the early screening of AA and CRC in the general population.

AIM

To identify serum protein biomarkers for the early screening of AA and CRC.

METHODS

We collected 43 serum samples from 8 normal controls (NCs), 19 AA patients and 16 CRC patients at China-Japan Friendship Hospital. Quantitative proteomic analysis was performed using liquid chromatography-mass spectrometry/mass spectrometry and data independent acquisition, and differentially expressed proteins (DEPs) with P-values < 0.05 and absolute fold changes > 1.5 were screened out, followed by bioinformatics analysis. Prognosis was further analyzed based on public databases, and proteins expression in tissues were validated by immunohistochemistry.

RESULTS

A total of 2132 proteins and 17365 peptides were identified in the serum samples. There were 459 upregulated proteins and 118 downregulated proteins in the NC vs AA group, 289 and 180 in the NC vs CRC group, and 52 and 248 in the AA vs CRC group, respectively. Bioinformatic analysis revealed that these DEPs had different functions and participated in extensive signaling pathways. We also identified DIAPH1, VASP, RAB11B, LBP, SAR1A, TUBGCP5, and DOK3 as important proteins for the progression of AA and CRC. Furthermore, VASP (P < 0.01), LBP (P = 0.01), TUBGCP5 (P < 0.01), and DOK3 (P < 0.01) were associated with a poor prognosis. In addition, we propose that LBP and VASP may be more promising protein biomarkers for the early screening of colorectal tumors.

CONCLUSION

Our study elucidated the serum proteomic profiles of AA and CRC patients, and the identified proteins, such as LBP and VASP, may contribute to the early detection of AA and CRC.

DIAPH2 gene polymorphisms and laryngeal cancer risk in men

BACKGROUND

The DIAPH2 gene is one of the genes commonly associated with laryngeal squamous cell carcinoma (LSCC). In our study, we considered the four polymorphisms of this gene, i.e. rs5920828, rs4322175, rs12851931 and rs5921830 as potential genetic risk factors for LSCC.

METHODS

We determined the genotyping of the genetic variants of DIAPH2 in 230 male patients with histologically confirmed LSCC compared to the European population. Demographic and environmental exposure data of each subject were examined. To conduct the genetic tests, extraction of total DNA was performed. We genotyped all four variants in each patient and determined their frequencies.

RESULTS

In the case of the rs12851931 polymorphism in the DIAPH2 gene, a significant difference was observed in the distribution of the T stage depending on the polymorphism. Heterozygotes were more often associated with T2 stage, while homozygotes were more likely to have higher tumor stages. The rs12851931 homozygotes of DIAPH2 were statistically significantly more prevalent in smokers. The results suggested that rs12851931 polymorphism in DIAPH2 could increase the onset risk of LSCC.

CONCLUSIONS

Our results provide further information on the role of the DIAPH2 gene in the pathogenesis of LSCC.

Formin protein DIAPH1 positively regulates PD-L1 expression and predicts the therapeutic response to anti-PD-1/PD-L1 immunotherapy

Formins are evolutionarily conserved genes and profoundly affect cancer progression. This study aims to explore the expressions, prognostic values, and immunological correlations of Formins in cancer. Specific Formins were dysregulated and immuno-biologically correlated in breast cancer (BRCA). Formins showed different expression patterns, namely some were enriched in immune cells while some were enriched in tumor cells. Among all Formins, DIAPH1 was enriched in tumor cells and associated with an inflamed tumor microenvironment (TME). DIAPH1 functioned as an oncogene in BRCA and mediated TGF-β1-induced epithelial-mesenchymal transformation (EMT) and PD-L1 expression. Moreover, DIAPH1 was overexpressed in most cancers and functioned as a novel pan-cancer immuno-marker, which could predict the response to anti-PD-1/PD-L1 immunotherapy. Overall, DIAPH1 functions as an oncogene and is immunologically correlated, which could be utilized as an alternative biomarker for predicting the immunotherapeutic response.

Diaphanous-related formin subfamily: Novel prognostic biomarkers and tumor microenvironment regulators for pancreatic adenocarcinoma

The diaphanous-related formin subfamily includes diaphanous homolog 1 (DIAPH1), DIAPH2, and DIAPH3. DIAPHs play a role in the regulation of actin nucleation and polymerization and in microtubule stability. DIAPH3 also regulates the assembly and bipolarity of mitotic spindles. Accumulating evidence has shown that DIAPHs are anomalously regulated during malignancy. In this study, we reviewed The Cancer Genome Atlas database and found that DIAPHs are abundantly expressed in pancreatic adenocarcinoma (PAAD). Furthermore, we analyzed the gene alteration profiles, protein expression, prognosis, and immune reactivity of DIAPHs in PAAD using data from several well-established databases. In addition, we conducted gene set enrichment analysis to investigate the potential mechanisms underlying the roles of DIAPHs in the carcinogenesis of PAAD. Finally, we performed the experimental validation of DIAPHs expression in several pancreatic cancer cell lines and tissues of patients. This study demonstrated significant correlations between DIAPHs expression and clinical prognosis, oncogenic signature gene sets, T helper 2 cell infiltration, plasmacytoid dendritic cell infiltration, myeloid-derived suppressor cell infiltration, ImmunoScore, and immune checkpoints in PAAD. These data may provide important information regarding the role and mechanisms of DIAPHs in tumorigenesis and PAAD immunotherapy.

Circ_0044556 Promotes the Progression of Colorectal Cancer via the miR-665-Dependent Expression Regulation of Diaphanous Homolog 1

BACKGROUND

Cancer progression can be regulated by noncoding circular RNAs. A recent study has indicated that circ_0044556 facilitated the progression of colorectal cancer.

AIM

This research was performed to explore the regulatory mechanism of circ_0044556 in CRC.

METHODS

Circ_0044556, miR-665 and Diaphanous Homolog 1 levels were detected by the quantitative real-time polymerase chain reaction. Cell proliferation analysis was performed by cell counting kit-8 assay and Edu assay. Cell cycle progression was assessed using flow cytometry. The protein examination was conducted using western blot. Transwell assay was used to analyze cell migration and invasion. Dual-luciferase reporter assay was performed to validate the interaction between targets. In vivo research was implemented by xenograft tumor assay.

RESULTS

Circ_0044556 was upregulated in colorectal cancer samples and cells. Silencing circ_0044556 inhibited cell proliferation, cell cycle progression, migration, invasion, and epithelial-mesenchymal transition in CRC cells. Circ_0044556 could directly target miR-665 and the function of circ_0044556 was associated with the regulation of miR-665. In addition, Diaphanous Homolog 1 was a target gene for miR-665 and the anti-tumor role of miR-665 in colorectal cancer was dependent on the downregulation of Diaphanous Homolog 1. Diaphanous Homolog 1 level was regulated by circ_0044556 via sponging miR-665 in CRC cells. In vivo assay suggested that circ_0044556 promoted CRC tumor growth by regulating the miR-665 and Diaphanous Homolog 1 levels.

CONCLUSION

Our findings manifested that circ_0044556 functioned as an oncogenic circRNA in colorectal cancer by mediating the miR-665/Diaphanous Homolog 1 axis, elucidating the molecular mechanism of circ_0044556 in CRC progression.

Ingestion of titanium dioxide nanoparticles: a definite health risk for consumers and their progeny

Titanium dioxide (TiO₂) is one of the most commonly used nanomaterials in the world. Additive E171, which is used in the food industry, contains a nanometric particle fraction of TiO₂. Oral exposure of humans to these nanoparticles (NPs) is intensive, leading to the question of their impact on health. Daily oral intake by rats of amounts of E171 that are relevant to human intake has been associated with an increased risk of chronic intestinal inflammation and carcinogenesis. Due to their food preferences, children are very exposed to this NP. Furthermore, maternal-foetal transfer of TiO₂ NPs during pregnancy, as well as exposure of the offspring by breastfeeding, have been recently described. In France, the use of E171 in the production of foodstuffs was suspended in January 2020 as a precautionary measure. To provide some answers to this public health problem and help global regulatory agencies finalize their decisions, we reviewed in vitro and in vivo studies that address the effects of TiO₂ NPs through oral exposure, especially their effects on the gastrointestinal tract, one of the most exposed tissues. Our review also highlights the effects of exposure on the offspring during pregnancy and by breastfeeding.

Mechanobiology of Colorectal Cancer

In this review, the mechanobiology of colorectal cancer (CRC) are discussed. Mechanotransduction of CRC is addressed considering the relationship of several biophysical cues and biochemical pathways. Mechanobiology is focused on considering how it may influence epithelial cells in terms of motility, morphometric changes, intravasation, circulation, extravasation, and metastization in CRC development. The roles of the tumor microenvironment, ECM, and stroma are also discussed, taking into account the influence of alterations and surface modifications on mechanical properties and their impact on epithelial cells and CRC progression. The role of cancer-associated fibroblasts and the impact of flow shear stress is addressed in terms of how it affects CRC metastization. Finally, some insights concerning how the knowledge of biophysical mechanisms may contribute to the development of new therapeutic strategies and targeting molecules and how mechanical changes of the microenvironment play a role in CRC disease are presented.

DIAPH1 facilitates paclitaxel-mediated cytotoxicity of ovarian cancer cells

The chemotherapeutic agent paclitaxel (PTX) selectively binds to and stabilizes microtubule (MTs). Also, the activated formin Diaphanous Related Formin 1 (DIAPH1) binds to MTs and increases its stability. In a recent study, we found that high DIAPH1 levels correlated with increased survival of ovarian cancer (Ovca) patients. A possible explanation for this finding is that Ovca cells with high DIAPH1 levels are more sensitive to PTX. To examine this assumption, in this study the effect of DIAPH1 depletion on PTX-mediated cytotoxicity of OVCAR8 and OAW42 cells was analyzed. Our data showed that down-regulation of DIAPH1 expression decreased PTX sensitivity in both cell lines by reducing apoptosis or necrosis. Analysis of MT stability by Western blotting revealed a decreased concentration of stable, detyrosinated MTs in PTX-treated DIAPH1 knock-down compared to control cells. Also, in fixed metaphase cells the level of stable, detyrosinated spindle MTs decreased in cells with reduced DIAPH1 expression. In vitro analysis with recombinant DIAPH1 protein showed that PTX and DIAPH1 exhibited additive effects on MT-polymerization, showing that also in a cell-free system DIAPH1 increased the effect of PTX on MT-stability. Together, our data strongly indicate that DIAPH1 increases the response of Ovca cells to PTX by enhancing PTX-mediated MT-stability.

DIAPH1 Promotes Laryngeal Squamous Cell Carcinoma Progression Through Cell Cycle Regulation

The diaphanous related formin 1 (DIAPH1) protein is involved in the regulation of dynamic cytoskeleton reorganization, which is closely related to mitosis and the cell cycle. Cell cycle disorders are generally regarded as important underlying causes of many cancers. In the current study, we have revealed that DIAPH1 expression is an independent prognostic factor for overall survival in patients with laryngeal squamous cell carcinoma (LSCC) and that DIAPH1 promotes colony formation, cell proliferation, and G1/S progression in LSCC cells. Additionally, DIAPH1 promotes growth of AMC-HN-8 LSCC-derived tumors in vivo. In this study, RNA-sequencing analysis revealed that DIAPH1 knockdown led to changes in the expression of genes associated with signaling during the cell cycle. Using western blot analyses, we further demonstrated that DIAPH1 knockdown resulted in upregulation of p21^Waf1/Cip1, p19^Ink4d, p27^Kip1, and p16^Ink4a and downregulation of cyclinA2, cyclinD1, CDK2, CDK4, and CDK6. These results suggest that DIAPH1 influences the expression of genes in several signaling pathways and promotes LSCC progression by regulating the cell cycle.

Formins in Human Disease

Almost 25 years have passed since a mutation of a formin gene, DIAPH1, was identified as being responsible for a human inherited disorder: a form of sensorineural hearing loss. Since then, our knowledge of the links between formins and disease has deepened considerably. Mutations of DIAPH1 and six other formin genes (DAAM2, DIAPH2, DIAPH3, FMN2, INF2 and FHOD3) have been identified as the genetic cause of a variety of inherited human disorders, including intellectual disability, renal disease, peripheral neuropathy, thrombocytopenia, primary ovarian insufficiency, hearing loss and cardiomyopathy. In addition, alterations in formin genes have been associated with a variety of pathological conditions, including developmental defects affecting the heart, nervous system and kidney, aging-related diseases, and cancer. This review summarizes the most recent discoveries about the involvement of formin alterations in monogenic disorders and other human pathological conditions, especially cancer, with which they have been associated. In vitro results and experiments in modified animal models are discussed. Finally, we outline the directions for future research in this field.

DIAPH1 regulates chromosomal instability of cancer cells by controlling microtubule dynamics

Chromosomal instability (CIN) is a hallmark of cancer, resulting from misalignment and missegregation of chromosomes during meta- and anaphase, due to non-precise regulation of spindle-MT dynamics. Diaphanous Related Formin 1 (DIAPH1) is an actin nucleator and also binds microtubule (MT) with high affinity. In this study, we analyzed the role of DIAPH1 in regulation of spindle MT-dynamics and CIN in HT29 and HCT-116 colorectal cancer (CRC) cells. Our data show that down-regulation of DIAPH1 in these cell lines decreased spindle-MT speed by 50 % and the fraction of cells with misaligned and missegregated chromosomes was significantly increased. Furthermore, in HCT-116 DIAPH1 depleted cells deviation of chromosome number was elevated and the number of cells with micronuclei and cytosolic DNA was increased in both DIAPH1-knock down cell lines. In line with these results, database analysis revealed a significant correlation with low DIAPH1 mRNA expression and aneuploidy. Thus, DIAPH1 is substantially involved in the control of CIN in CRC cells. Since in vitro, DIAPH1 directly increased MT-polymerization, we assume that DIAPH1 controls CIN by regulating spindle-MT dynamics.

Actin regulators in cancer progression and metastases: From structure and function to cytoskeletal dynamics

The cytoskeleton is a central factor contributing to various hallmarks of cancer. In recent years, there has been increasing evidence demonstrating the involvement of actin regulatory proteins in malignancy, and their dysregulation was shown to predict poor clinical prognosis. Although enhanced cytoskeletal activity is often associated with cancer progression, the expression of several inducers of actin polymerization is remarkably reduced in certain malignancies, and it is not completely clear how these changes promote tumorigenesis and metastases. The complexities involved in cytoskeletal induction of cancer progression therefore pose considerable difficulties for therapeutic intervention; it is not always clear which cytoskeletal regulator should be targeted in order to impede cancer progression, and whether this targeting may inadvertently enhance alternative invasive pathways which can aggravate tumor growth. The entire constellation of cytoskeletal machineries in eukaryotic cells are numerous and complex; the system is comprised of and regulated by hundreds of proteins, which could not be covered in a single review. Therefore, we will focus here on the actin cytoskeleton, which encompasses the biological machinery behind most of the key cellular functions altered in cancer, with specific emphasis on actin nucleating factors and nucleation-promoting factors. Finally, we discuss current therapeutic strategies for cancer which aim to target the cytoskeleton.

Comprehensive DNA Methylation Profiling Identifies Novel Diagnostic Biomarkers for Thyroid Cancer

Background: There are no reliable biomarkers to accurately differentiate indolent thyroid tumors from more aggressive thyroid cancers. This study aimed to develop new DNA methylation markers for diagnosis and recurrence risk stratification of papillary thyroid carcinoma (PTC). Methods: Thyroid tumor-specific DNA methylation profiling was investigated in 34 fresh frozen tissues, which included nontumor (n = 7), noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP, n = 6) and PTC (n = 21), using the Illumina HumanMethylation EPIC array. We performed a genome-wide assessment of thyroid tumor-specific differentially methylated CpG sites in the discovery set, then validated the top candidate markers in an independent set of 293 paraffin tissue samples comprised of follicular adenoma (FA, n = 61), Hürthle cell adenoma (HA, n = 24), NIFTP (n = 56), PTC (n = 120), follicular thyroid carcinoma (n = 27), and Hürthle cell carcinoma (n = 5), by pyrosequencing. Results: Three selected markers (cg10705422, cg17707274, and cg26849382) differentiated nonmalignant (FA, HA, and NIFTP) tumors from differentiated thyroid cancers with area under the receiver operating characteristic curve of 0.83, 0.83, and 0.80, respectively. Low DNA methylation levels for three markers were significantly associated with recurrent or persistent disease (odds ratio (OR) = 3.860 [95% confidence interval (CI) 1.194-12.475]) and distant metastasis (OR = 4.009 [CI 1.098-14.632]) in patients with differentiated thyroid cancer. A subgroup analysis for the validation set showed that PTC patients with low DNA methylation levels more frequently had aggressive histology, extrathyroidal extension, lymph node metastasis, BRAF^V600E mutations, and recurrent or persistent disease than those with high levels of methylation markers. All PTC patients who developed disease recurrence had low DNA methylation levels for three markers. Conclusions: DNA methylation levels of three markers can be useful for differentiating differentiated thyroid cancer from nonmalignant follicular thyroid lesions, and may serve as prognostic biomarkers for predicting recurrent or persistent disease after surgery for differentiated thyroid cancer.

Association of DIAPH1 gene polymorphisms with ischemic stroke

DIAPH1 is a formin protein involved in actin polymerization with important roles in vascular remodeling and thrombosis. To investigate potential associations of DIAPH1 single-nucleotide polymorphisms (SNPs) with hypertension and stroke, 2,012 patients with hypertension and 2,210 controls, 2,966 stroke cases [2,212 ischemic stroke (IS), 754 hemorrhagic stroke (HS)] and 2,590 controls were enrolled respectively in the case-control study. A total of 4,098 individual were included in the cohort study. DIAPH1 mRNA expression was compared between 66 IS [43 small artery occlusion (SAO) and 23 large-artery atherosclerosis (LAA)] and 58 controls. Odds ratio (OR), hazard ratio (HR) and 95% confidence interval (CI) were calculated by logistic and cox regression analysis. Rs7703688 T>C variation was significantly associated with an increased risk of IS [OR (95% CI) was 1.721 (1.486-1.993), P=4.139×10^-12]. Association of rs7703688 with stroke risk was further validated in the cohort study [adjusted HRs (95% CIs) for additive and recessive models were 1.385 (1.001-1.918), P=0.049, and 2.882 (1.038-8.004), P=0.042, respectively)]. DIAPH1 mRNA expression was significantly downregulated in IS. In SAO stroke subtype, DIAPH1 expression has an increased trend among rs251019 genotypes (P_trend=0.048). These novel findings suggest that DIAPH1 variation contributes to genetic susceptibility to stroke risk, especially the SAO subtype of IS.

Formin-like 1 (FMNL1) Is Associated with Glioblastoma Multiforme Mesenchymal Subtype and Independently Predicts Poor Prognosis

Glioblastoma multiforme (GBM), the most common primary malignant brain tumor in adults, is characterized by rapid proliferation, aggressive migration, and invasion into normal brain tissue. Formin proteins have been implicated in these processes. However, the role of formin-like 1 (FMNL1) in cancer remains unclear. We studied FMNL1 expression in glioblastoma samples using immunohistochemistry. We sought to analyze the correlation between FMNL1 expression, clinicopathologic variables, and patient survival. Migration and invasion assays were used to verify the effect of FMNL1 on glioblastoma cell lines. Microarray data were downloaded from The Cancer Genome Atlas and analyzed using gene set enrichment analysis (GSEA). FMNL1 was an independent predictor of poor prognosis in a cohort of 217 glioblastoma multiforme cases (p < 0.001). FMNL1 expression was significantly higher in the mesenchymal subtype. FMNL1 upregulation and downregulation were associated with mesenchymal and proneural markers in the GSEA, respectively. These data highlight the important role of FMNL1 in the neural-to-mesenchymal transition. Conversely, FMNL1 downregulation suppressed glioblastoma multiforme cell migration and invasion via DIAPH1 and GOLGA2, respectively. FMNL1 downregulation also suppressed actin fiber assembly, induced morphological changes, and diminished filamentous actin. FMNL1 is a promising therapeutic target and a useful biomarker for GBM progression.

The formin Drosophila homologue of Diaphanous2 (Diaph2) controls microtubule dynamics in colorectal cancer cells independent of its FH2-domain

In this study, we analyzed the functional role of the formin Drosophila Homologue of Diaphanous2 (Diaph2) in colorectal cancer cells. We show that stable down-regulation of Diaph2 expression in HT29 cells decreased chromosome alignment and the velocity of chromosome movement during M-phase, thus reducing the proliferation rate and colony formation. In interphase cells, Diaph2 was diffusely distributed in the cytosol, while in metaphase cells the protein was located to spindle microtubules (MTs). Diaph2-depletion increased the concentration of stable spindle MTs, showing that the formin is required to control spindle MT-dynamics. Our cellular data indicate that Diaph2-controls spindle MT-dynamics independent of Cdc42 activity and our in vitro results reveal that bacterially produced full-length (FL) Diaph2 strongly altered MT-dynamics in absence of Cdc42, where its actin-nucleating activity is auto-inhibited. FL-Diaph2 mediates a 10-fold increase in MT-polymerization compared to the Diaph2-FH2-domain. Interestingly, a Diaph2-mutant lacking the FH2-domain (ΔFH2) increased MT-polymerization to a similar extent as the FH2-domain, indicating the existence of a second MT-binding domain. However, in contrast to FL-Diaph2 and the FH2-domain, ΔFH2 did not alter the density of taxol-stabilized MTs. Thus, the FH2-domain and the second Diaph2-binding domain appear to control MT-dynamics by different mechanisms. In summary, our data indicate that Diaph2 controls M-phase progression under basal conditions by regulating spindle MT-dynamics. In addition, a region outside of the canonical MT-regulating FH2-domain is involved in Diaph2-mediated control of MT-dynamics.

DIAPH1 Is Upregulated and Inhibits Cell Apoptosis through ATR/p53/Caspase-3 Signaling Pathway in Laryngeal Squamous Cell Carcinoma

Cancer bioinformatics has been used to screen possible key cancer genes and pathways. Here, through bioinformatics analysis, we found that high expression of diaphanous related formin 1 (DIAPH1) was associated with poor overall survival in head and neck squamous cell carcinoma and laryngeal squamous cell carcinoma (LSCC). The effect of DIAPH1 in LSCC has not been previously investigated. Therefore, we evaluated the expression, function, and molecular mechanisms of DIAPH1 in LSCC. Immunohistochemistry and western blot analysis confirmed the significant upregulation of DIAPH1 in LSCC. We used DIAPH1 RNA interference to construct two DIAPH1-knockdown LSCC cell lines, AMC-HN-8 and FD-LSC-1, and validated the knockdown efficiency. Flow cytometry data showed that DIAPH1 inhibited apoptosis. Further, western blot analysis revealed that DIAPH1 knockdown increased the protein levels of ATR, p-p53, Bax, and cleaved caspase-3, -8, and -9. Thus, DIAPH1 is upregulated in LSCC and may act as an oncogene by inhibiting apoptosis through the ATR/p53/caspase-3 pathway in LSCC cells.

The Formin mDia1 Regulates Acute Lymphoblastic Leukemia Engraftment, Migration, and Progression in vivo

Leukemias typically arise in the bone marrow and then spread to the blood and into other tissues. To disseminate into tissues, leukemia cells migrate into the blood stream and then exit the circulation by migrating across vascular endothelial barriers. Formin proteins regulate cytoskeletal remodeling and cell migration of normal and malignant cells. The Formin mDia1 is highly expressed in transformed lymphocytes and regulates lymphocyte migration. However, the role of mDia1 in regulating leukemia progression in vivo is unknown. Here, we investigated how mDia1 mediates the ability of leukemia cells to migrate and disseminate in vivo. For these studies, we used a mouse model of Bcr-Abl pre-B cell acute lymphoblastic leukemia. Our data showed that mDia1-deficient leukemia cells have reduced chemotaxis and ability to complete transendothelial migration in vitro. In vivo, mDia1 deficiency reduced the ability of leukemia cells to engraft in recipient mice. Furthermore, leukemia dissemination to various tissues and leukemia progression were inhibited by mDia1 depletion. Finally, mDia1 depletion in leukemia cells resulted in prolonged survival of recipient mice in a leukemia transfer model. Overall, our data show that the Formin mDia1 mediates leukemia cell migration, and drives leukemia engraftment and progression in vivo, suggesting that targeting mDia1 could provide a new method for treatment of leukemia.

Influence of Adalimumab on the Expression Profile of Genes Associated with the Histaminergic System in the Skin Fibroblasts In Vitro

Objective

The aim of this study was to evaluate the influence of adalimumab on expression profile of genes associated with the histaminergic system in Normal Human Dermal Fibroblast (NHDF) cells stimulated with 8.00 μg/ml of adalimumab and the identification of miRNAs regulating these genes' expression.

Methods

NHDFs were cultured with or without the presence of adalimumab for 2, 8, and 24 hours. The expression profile of genes and miRNA were determined with the use of microarray technology.

Results

Among 22283 ID mRNA, 65 are associated with the histaminergic system. It can be observed that 15 mRNAs differentiate NHDFs cultures with adalimumab form control. The analysis of miRNAs showed that, among 1105 ID miRNA, 20 miRNAs are differentiating in cells treated with adalimumab for 2 hours, 9 miRNA after 8 hours, and only 3 miRNAs after 24 hours.

Conclusion

It was also determined that miRNAs play certain role in the regulation of the expression of genes associated with the histaminergic system. The results of this study confirmed the possibility of using both genes associated with this system as well as miRNAs regulating their expression, as complementary molecular markers of sensitivity to the adalimumab treatment.

Gene expression profiling in colon of mice exposed to food additive titanium dioxide (E171)

Dietary factors that may influence the risks of colorectal cancer, including specific supplements, are under investigation. Previous studies showed the capacity of food additive titanium dioxide (E171) to induce DNA damage in vitro and facilitate growth of colorectal tumours in vivo. This study aimed to investigate the molecular mechanisms behind these effects after E171 exposure. BALB/c mice were exposed by gavage to 5 mg/kg_bw/day of E171 for 2, 7, 14, and 21 days. Transcriptome changes were studied by whole genome mRNA microarray analysis on the mice's distal colons. In addition, histopathological changes as well as a proliferation marker were analysed. The results showed significant gene expression changes in the olfactory/GPCR receptor family, oxidative stress, the immune system and of cancer related genes. Transcriptome analysis also identified genes that thus far have not been included in known biological pathways and can induce functional changes by interacting with other genes involved in different biological pathways. Histopathological analysis showed alteration and disruption in the normal structure of crypts inducing a hyperplastic epithelium. At cell proliferation level, no consistent increase over time was observed. These results may offer a mechanistic framework for the enhanced tumour growth after ingestion of E171 in BALB/c mice.

Strong fascin expression promotes metastasis independent of its F-actin bundling activity

High expression of the actin bundling protein Fascin increases the malignancy of tumor cells. Here we show that fascin expression is up-regulated in more malignant sub-cell lines of MDA-MB-231 cells as compared to parental cells. Since also parental MDA-MB-231 cells exhibit high fascin levels, increased fascin expression was termed as “hyperexpression”. To examine the effect of fascin hyperexpression, fascin was hyperexpressed in parental MDA-MB-231 cells and metastasis was analyzed in NOD scid gamma (NSG) mice. In addition, the effect of fascin mutants with inactive or constitutively active actin bundling activity was examined. Unexpectedly, we found that hyperexpression of both, wildtype (wt) and mutant fascin strongly increased metastasis in vivo, showing that the effect of fascin hyperexpression did not depend on its actin bundling activity. Cellular assays revealed that hyperexpression of wt and mutant fascin increased adhesion of MDA-MB-231 cells while transmigration and proliferation were not affected. Since it has been shown that fascin controls adhesion by directly interacting with microtubules (MTs), we analyzed if fascin hyperexpression affects MT dynamics. We found that at high concentrations fascin significantly increased MT dynamics in cells and in cell-free approaches. In summary our data show that strong expression of fascin in breast cancer cells increases metastasis independent of its actin bundling activity. Thus, it seems that the mechanism of fascin-stimulated metastasis depends on its concentration.

EGF hijacks miR-198/FSTL1 wound-healing switch and steers a two-pronged pathway toward metastasis

Exploring the parallels between wound healing and epithelial cancers, Sundaram et al. elucidate the mechanism by which cancer cells hijack the wound healing switch to enhance invasion and metastasis in head and neck squamous cell carcinoma.

Epithelial carcinomas are well known to activate a prolonged wound-healing program that promotes malignant transformation. Wound closure requires the activation of keratinocyte migration via a dual-state molecular switch. This switch involves production of either the anti-migratory microRNA miR-198 or the pro-migratory follistatin-like 1 (FSTL1) protein from a single transcript; miR-198 expression in healthy skin is down-regulated in favor of FSTL1 upon wounding, which enhances keratinocyte migration and promotes re-epithelialization. Here, we reveal a defective molecular switch in head and neck squamous cell carcinoma (HNSCC). This defect shuts off miR-198 expression in favor of sustained FSTL1 translation, driving metastasis through dual parallel pathways involving DIAPH1 and FSTL1. DIAPH1, a miR-198 target, enhances directional migration through sequestration of Arpin, a competitive inhibitor of Arp2/3 complex. FSTL1 blocks Wnt7a-mediated repression of extracellular signal–regulated kinase phosphorylation, enabling production of MMP9, which degrades the extracellular matrix and facilitates metastasis. The prognostic significance of the FSTL1-DIAPH1 gene pair makes it an attractive target for therapeutic intervention.

Drosophila homologue of Diaphanous 1 (DIAPH1) controls the metastatic potential of colon cancer cells by regulating microtubule-dependent adhesion

Drosophila homologue of Diaphanous 1 (DIAPH1) regulates actin polymerization and microtubule (MT) stabilization upon stimulation with lysophosphatidic acid (LPA). Recently, we showed strongly reduced lung metastasis of DIAPH1-depleted colon cancer cells but we found accumulations of DIAPH1-depleted cells in bone marrow. Here, we analyzed possible organ- or tissue-specific metastasis of DIAPH1-depleted HCT-116 cells. Our data confirmed that depletion of DIAPH1 strongly inhibited lung metastasis and revealed that, in contrast to control cells, DIAPH1-depleted cells did not form metastases in further organs. Detailed mechanistic analysis on cells that were not stimulated with LPA to activate the cytoskeleton-modulating activity of DIAPH1, revealed that even under basal conditions DIAPH1 was essential for cellular adhesion to collagen. In non-stimulated cells DIAPH1 did not control actin dynamics but, interestingly, was essential for stabilization of microtubules (MTs). Additionally, DIAPH1 controlled directed vesicle trafficking and with this, local clustering of the adhesion protein integrin-β1 at the plasma membrane. Therefore, we conclude that under non-stimulating conditions DIAPH1 controls cellular adhesion by stabilizing MTs required for local clustering of integrin-β1 at the plasma membrane. Thus, blockade of DIAPH1-tubulin interaction may be a promising approach to inhibit one of the earliest steps in the metastatic cascade of colon cancer.

Distinct impact of targeted actin cytoskeleton reorganization on mechanical properties of normal and malignant cells

The actin cytoskeleton is substantially modified in cancer cells because of changes in actin-binding protein abundance and functional activity. As a consequence, cancer cells have distinctive motility and mechanical properties, which are important for many processes, including invasion and metastasis. Here, we studied the effects of actin cytoskeleton alterations induced by specific nucleation inhibitors (SMIFH2, CK-666), cytochalasin D, Y-27632 and detachment from the surface by trypsinization on the mechanical properties of normal Vero and prostate cancer cell line DU145. The Young's modulus of Vero cells was 1300±900 Pa, while the prostate cancer cell line DU145 exhibited significantly lower Young's moduli (600±400 Pa). The Young's moduli exhibited a log-normal distribution for both cell lines. Unlike normal cells, cancer cells demonstrated diverse viscoelastic behavior and different responses to actin cytoskeleton reorganization. They were more resistant to specific formin-dependent nucleation inhibition, and reinforced their cortical actin after detachment from the substrate. This article is part of a Special Issue entitled: Mechanobiology.

Ex vivo aorta patch model for analysis of cellular adhesion

The vascular endothelium as well as subendothelium are objects of many researches as it is directly involved in a multiplicity of physiological and pathological settings. Detailed study of endothelial function became feasible with the development of techniques to culture endothelial cells (EC) in vitro. Limitations of this approach have become apparent with the realization that cell culture dedifferentiate with time and do not exhibit properties of intact tissue. Here we describe the development of a novel ex vivo tissue model to study cell-vascular wall interactions by using isolated mouse aorta patches. Validation of this model was performed by demonstrating cell attachment and changes in cell shape typical for cell spreading during adhesion. A major advantage of this model is that cell-endothelium interaction and its molecular backgrounds can now be studied more feasibly on an intact and native tissue.

Increased expression of formin-like 3 contributes to metastasis and poor prognosis in colorectal carcinoma

Formin-like 3 (FMNL3), a member of diaphanous-related formins subfamily, plays an important role in cytoskeleton reorganization, cell adhesion and cancer cell invasion in vitro. This study aimed to explore the expression of FMNL3 in colorectal carcinoma (CRC) cell-lines and tissues, and further evaluate its prognostic value and correlation with the clinicopathological parameters, and also investigate the effects of FMNL3 gene silencing on the growth and metastasis of CRC in vivo. Immunohistochemical analysis showed that FMNL3 protein was distributed in a punctuate aggregation pattern and located mainly in the cytoplasm of glandular cavity side, close to the nucleus of CRC cells. The positive rate of FMNL3 expression was 87.5% (84/96) in CRC, which was significantly higher than that in adjacent normal mucosa (30%, 9/30). Moreover, FMNL3 protein expressed far more in primary CRC with metastasis and corresponding lymph nodes metastatic CRC than in primary CRC without metastasis. Increased expression of FMNL3 was closely correlated with tumor size, differentiation, serosal invasion, and both lymph node metastasis and distant metastasis. However, it was not correlated with patients' age and gender. According to Kaplan-Meier survival analyses, patients with FMNL3 high expression level had lower overall survival rate than that with FMNL3 low expression level. Univariate and multivariate analyses revealed that high FMNL3 expression was a significant and independent prognostic predictor of patients with CRC. In addition, FMNL3 mRNA and protein levels were substantially up-regulated in CRC-metastasis-derived cell lines, as compared to those in primary-CRC-derived ones. FMNL3 gene silencing suppressed the growth and metastasis of CRC in vivo. In conclusion, FMNL3 plays an important role in the progression and metastasis of CRC and may be a novel potential prognostic predictor and therapeutic target for patients with CRC.

Expression and Y435-phosphorylation of Abelson interactor 1 (Abi1) promotes tumour cell adhesion, extracellular matrix degradation and invasion by colorectal carcinoma cells

Background

The Abelson tyrosine kinase (c-Abl) inhibitor STI571 (Glivec®) has been shown to effectively inhibit colorectal cancer cell migration and invasion. The c-Abl substrate abelson interactor 1 (Abi1) is a key regulator of actin reorganization and upregulated in colorectal carcinoma. The specific role of Abi1 in relation to extracellular matrix degradation and effects of targeting Abi1 phosphorylation have not yet been examined. Here, we investigated the role of Abi1 in relation to invasive properties in colorectal cancer.

Methods and results

In 56 primary human colorectal carcinoma samples, we found overexpression of Abi1 in 39% at the invasive edge of the tumour, associated with an infiltrative phenotype and high-grade tumour cell budding (p = 0.001). To explore the role of Abi1 in vitro, we employed the Abi1 expressing and KRAS-mutated CHD1 model and performed matrix degradation assays that showed Abi1 localization at specific sites of matrix degradation. Moreover, quantification of matrix dissolution demonstrated suppression after RNAi knockdown of Abi1 by 95% (p = 0.001). Importantly, treatment with STI571 did abolish Abi1 Y435-phosphorylation, suppressed the matrix dissolution, decreased fibronectin attachment, and suppressed cell invasion through reconstituted extracellular matrix.

Conclusion

Our data indicate that phosphorylated Abi1 contributes to the invasive properties of colorectal cancer.