Sulforaphane suppresses bladder cancer metastasis via blocking actin nucleation-mediated pseudopodia formation

Metastasis is the primary stumbling block to the treatment of bladder cancer (BC). In order to spread, tumor cells must acquire increased migratory and invasive capacity, which is tightly linked with pseudopodia formation. Here, we unravel the effects of sulforaphane (SFN), an isothiocyanate in cruciferous vegetables, on the assembly of pseudopodia and BC metastasis, and its molecular mechanism in the process. Our database analysis revealed that in bladder tumor, pseudopodia-associated genes, CTTN, WASL and ACTR2/ARP2 are upregulated. SFN caused lamellipodia to collapse in BC cells by blocking the CTTN-ARP2 axis. SFN inhibited invadopodia formation and cell invasion by reducing WASL in different invasive BC cell lines. The production of ATP, essential for the assembly of pseudopodia, was significantly increased in bladder tumors and strongly inhibited by SFN. Overexpressing AKT1 reversed the downregulation of ATP in SFN-treated bladder cancer cells and restored filopodia and lamellipodia morphology and function. Bioluminescent imaging showed that SFN suppressed BC metastases to the lung of nude mice while downregulating Cttn and Arp2 expression. Our study thus reveals mechanisms of SFN action in inhibiting pseudopodia formation and highlights potential targeting options for the therapy of metastatic bladder cancer.

Isoprenylcysteine carboxyl methyltransferase (ICMT) promotes invadopodia formation and metastasis in cancer cells

Isoprenyl cysteine carboxyl methyltransferase (ICMT) catalyzes the last step of the prenylation pathway. Previously, we found that high ICMT levels enhance tumorigenesis in vivo and that its expression is repressed by the p53 tumor suppressor. Based on evidence suggesting that some ICMT substrates affect invasive traits, we wondered if this enzyme may promote metastasis. In this work, we found that ICMT overexpression enhanced lung metastasis in vivo. Accordingly, ICMT overexpression also promoted cellular functions associated with aggressive phenotypes such as migration and invasion in vitro. Considering that some ICMT substrates are involved in the regulation of actin cytoskeleton, we hypothesized that actin-rich structures, associated with invasion and metastasis, may be affected. Our findings revealed that ICMT enhanced the formation of invadopodia. Additionally, by analyzing cancer patient databases, we found that ICMT is overexpressed in several tumor types. Furthermore, the concurrent expression of ICMT and CTTN, which encodes a crucial component of invadopodia, showed a significant correlation with clinical outcome. In summary, our work identifies ICMT overexpression as a relevant alteration in human cancer that promotes the development of metastatic tumors.

Cortactin-dependent control of Par1b-regulated epithelial cell polarity in Helicobacter infection

Cell polarity is crucial for gastric mucosal barrier integrity and mainly regulated by polarity-regulating kinase partitioning-defective 1b (Par1b). During infection, the carcinogen Helicobacter pylori hijacks Par1b via the bacterial oncoprotein CagA leading to loss of cell polarity, but the precise molecular mechanism is not fully clear. Here we discovered a novel function of the actin-binding protein cortactin in regulating Par1b, which forms a complex with cortactin and the tight junction protein zona occludens-1 (ZO-1). We found that serine phosphorylation at S405/418 and the SH3 domain of cortactin are important for its interaction with both Par1b and ZO-1. Cortactin knockout cells displayed disturbed Par1b cellular localization and exhibited morphological abnormalities that largely compromised transepithelial electrical resistance, epithelial cell polarity, and apical microvilli. H. pylori infection promoted cortactin/Par1b/ZO-1 abnormal interactions in the tight junctions in a CagA-dependent manner. Infection of human gastric organoid-derived mucosoids supported these observations. We therefore hypothesize that CagA disrupts gastric epithelial cell polarity by hijacking cortactin, and thus Par1b and ZO-1, suggesting a new signaling pathway for the development of gastric cancer by Helicobacter.

MCT4 and CD147 colocalize with MMP14 in invadopodia and support matrix degradation and invasion by breast cancer cells

Expression levels of the lactate-H+ cotransporter MCT4 (also known as SLC16A3) and its chaperone CD147 (also known as basigin) are upregulated in breast cancers, correlating with decreased patient survival. Here, we test the hypothesis that MCT4 and CD147 favor breast cancer invasion through interdependent effects on extracellular matrix (ECM) degradation. MCT4 and CD147 expression and membrane localization were found to be strongly reciprocally interdependent in MDA-MB-231 breast cancer cells. Overexpression of MCT4 and/or CD147 increased, and their knockdown decreased, migration, invasion and the degradation of fluorescently labeled gelatin. Overexpression of both proteins led to increases in gelatin degradation and appearance of the matrix metalloproteinase (MMP)-generated collagen-I cleavage product reC1M, and these increases were greater than those observed upon overexpression of each protein alone, suggesting a concerted role in ECM degradation. MCT4 and CD147 colocalized with invadopodia markers at the plasma membrane. They also colocalized with MMP14 and the lysosomal marker LAMP1, as well as partially with the autophagosome marker LC3, in F-actin-decorated intracellular vesicles. We conclude that MCT4 and CD147 reciprocally regulate each other and interdependently support migration and invasiveness of MDA-MB-231 breast cancer cells. Mechanistically, this involves MCT4-CD147-dependent stimulation of ECM degradation and specifically of MMP-mediated collagen-I degradation. We suggest that the MCT4-CD147 complex is co-delivered to invadopodia with MMP14.

Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization

How cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIRF microscopy, we observe that GMF's branch destabilizing activities are potently blocked by cortactin (IC50 = 1.3 nM) and that this inhibition requires direct interactions of cortactin with Arp2/3 complex. The simplest model that would explain these results is competition for binding Arp2/3 complex. However, we find that cortactin and GMF do not compete for free Arp2/3 complex in solution. Further, we use single molecule analysis to show that cortactin's on-rate (3 ×107 s-1 M-1) and off-rate (0.03 s-1) at branch junctions are minimally affected by excess GMF. Together, these results show that cortactin binds with high affinity to branch junctions, where it blocks the destabilizing effects of GMF, possibly by a mechanism that is allosteric in nature. In addition, the affinities we measure for cortactin at actin filament branch junctions (Kd = 0.9 nM) and filament sides (Kd = 206 nM) are approximately 20-fold stronger than previously reported. These observations contribute to an emerging view of molecular complexity in how Arp2/3 complex is regulated through the integration of multiple inputs.

Targeting cholesterol impairs cell invasion of all breast cancer types

BACKGROUND

Breast cancer clinical outcome relies on its intrinsic molecular subtype and mortality is almost exclusively due to metastasis, whose mechanism remains unclear. We recently revealed the specific contribution of plasma membrane cholesterol to the invasion of malignant MCF10CAIa but not premalignant MCF10AT and normal MCF10A cell lines in 2D, through invadopodia formation and extracellular matrix (ECM) degradation. In the present study, we address the impact of breast cancer subtypes, mutations and aggressiveness on cholesterol implication in breast cancer cell invasion and 3D spheroid invasion and growth.

METHODS

We used nine breast cancer cell lines grouped in four subtypes matching breast tumor classification. Four of these cell lines were also used to generate 3D spheroids. These cell lines were compared for cell invasion in 2D and 3D, spheroid growth in 3D, gelatin degradation, cortactin expression, activation and subcellular distribution as well as cell surface cholesterol distribution and lipid droplets. The effect of plasma membrane cholesterol depletion on all these parameters was determined in parallel and systematically compared with the impact of global matrix metalloproteinase (MMP) inhibition.

RESULTS

The six invasive cell lines in 2D were sensitive to partial cholesterol depletion, independently of their subtype, aggressiveness or mutation. Nevertheless, the effect was stronger in the three cell lines able to degrade gelatin. 3D spheroid invasion was also reduced after cholesterol depletion in all breast cancer subtypes tested. Notably, targeting cholesterol was more powerful than MMP inhibition in reducing invasion in both 2D and 3D culture models. Moreover, cholesterol depletion in the six invasive cell lines impaired cortactin distribution in the perinuclear region where invadopodia localized. Breast cancer cell line aggressiveness relied on cholesterol-enriched domains at the ECM-free side and intracellular lipid droplets. Furthermore, the three gelatin-degrading cell lines were characterized by increased cholesterol-enriched submicrometric domains at their ECM-contact side.

CONCLUSION

Together, our data suggest cell surface cholesterol combined with lipid droplet labeling as a breast cancer cell aggressiveness marker. They also open the way to test other cholesterol-targeting drugs in more complex models to further evaluate whether cholesterol could represent a strategy in breast cancer therapy.

Assessment of Invadopodium Formation and Gelatin Degradation in Vitro

Some cancer cells form highly regulated structures, termed invadopodia, which mediate local, enzymatic degradation of extracellular matrix and facilitate cancer cell invasion and migration during metastatic progression. Understanding invadopodium formation and function in cancer cells is therefore an important strategy to find novel clinical approaches to interfere with metastasis. Invadopodia are F-actin-rich protrusions that form on the advancing edge of cells, supported by complex molecular interactions at the cell membrane. Invadopodia formation, structure, and function can be studied in vitro, using commonly cultured cancer cell lines and standard microscopic techniques. Here, these approaches are described in detail.

Prognostic impact of cortactin in patients with hypopharyngeal cancer and its role for tegafur-uracil maintenance after adjuvant chemoradiotherapy

The prognosis of patients with hypopharyngeal cancer (HPC) remains poor. Our study aims to investigate the prognostic impact of cortactin in patients with HPC and its role for tegafur-uracil (UFUR) maintenance after adjuvant chemoradiotherapy (CRT). Patients who were diagnosed to have HPC and underwent laryngopharyngectomy followed by adjuvant CRT were enrolled into our study. Immunohistochemical staining was performed for cortactin evaluation. Kaplan-Meier curves were depicted for recurrence-free survival (RFS) and overall survival (OS). A total of 157 patients were enrolled into our study. After stratified by cortactin, 53 patients were cortactin (+) and 104 patients were cortactin (-). The median RFS was 86.7 months in cortactin (-) and 10.2 months in cortactin (+) (P < 0.001). The median OS was 93.4 months in cortactin (-) and 16.9 months in cortactin (+) (P < 0.001). Patients were further classified according to UFUR maintenance or not after adjuvant CRT. In cortactin (+) patients, the median RFS and OS were 13.6 months versus 7.0 months (P = 0.006) and 24.0 months versus 10.0 months (P < 0.001) in UFUR (+) and UFUR (-), respectively. In cortactin (-) patients, the median RFS and OS were 96.0 months versus 72.2 months (P = 0.262) and 98.5 months versus 105.0 months (P = 0.665) in UFUR (+) and UFUR (-), respectively. Cortactin has a significantly impact in HPC patients. UFUR maintenance provided survival benefits in patients with cortactin (+) after adjuvant CRT.

Cortactin contributes to the tumorigenesis of gastric cancer by activating ERK/MMP pathway

Gastric cancer is a malignant tumor with high mortality and high incidence. This study aims to explore the function and molecular mechanism of Cortactin on gastric cancer progression in vitro and in vivo. A bioinformatics analysis from TCGA displayed that Cortactin was highly expressed in gastric cancer samples, and patients with a high Cortactin level had a worse survival rate. Subsequently, we investigated the specific mechanism of action of A in gastric cancer by collecting patient samples for immunohistochemistry, WB, qRT-PCR, cell transfection, cell invasion and metastasis, and constructing tumor xenografts in nude mice. Overexpression of Cortactin inhibited apoptosis and enhanced cellular proliferation and mobility in AGS cells, while those activities were reversed by the knockdown of MMP2 or MMP9. Conversely, the deletion of Cortactin induced apoptosis and suppressed cell growth and metastasis in SGC7901 cells, whereas those behaviors were inhibited by overexpression of MMP2 or MMP9. Additionally, the ERK pathway was activated by Cortactin upregulation. In vivo studies presented that overexpression of Cortactin promoted tumor growth, increased Ki67 expression, and reduced caspase 3 expression, which was reversed by ERK inhibitor treatment. In conclusion, Cortactin acted as an oncogene in gastric cancer and exerted its function by ERK/MMP2/MMP9 signaling pathway.

Binding of USP4 to cortactin enhances cell migration in HCT116 human colon cancer cells

Ubiquitin-specific protease 4 (USP4) is highly overexpressed in colon cancer and acts as a potent protooncogenic protein by deubiquitinating β-catenin. However, its prominent roles in tumor formation and migration in cancer cells are not fully understood by its deubiquitinating enzyme (DUB) activity on β-catenin. Thus, we investigated an additional role of USP4 in cancer. In this study, we identified cortactin (CTTN), an actin-binding protein involved in the regulation of cytoskeleton dynamics and a potential prognostic marker for cancers, as a new cellular interacting partner of USP4 from proximal labeling of HCT116 cells. Additionally, the role of USP4 in CTTN activation and promotion of cell dynamics and migration was investigated in HCT116 cells. We confirmed that interacting of USP4 with CTTN increased cell movement. This finding was supported by the fact that USP4 overexpression in HCT116 cells with reduced expression of CTTN was insufficient to promote cell migration. Additionally, we observed that USP4 overexpression led to a significant increase in CTTN phosphorylation, which is a requisite mechanism for cell migration, by regulating Src/focal adhesion kinase (FAK) binding to CTTN and its activation. Our results suggest that USP4 plays a dual role in cancer progression, including stabilization of β-catenin as a DUB and interaction with CTTN to promote cell dynamics by inducing CTTN phosphorylation. Therefore, this study demonstrates that USP4 is important for cancer progression and is a good target for treating or preventing cancer.

Down-regulating Effect of a Standardized Extract of Cultured Lentinula edodes mycelia on Cortactin in Prostate Cancer Cells Is Dependent on Malignant Potential

BACKGROUND/AIM

The incidence and mortality rates of prostate cancer have been increasing worldwide. Although prostate cancer cells grow slowly in the local original site, once the cancer cells spread to distant organs they grow rapidly and show very aggressive features. Cortactin is a protein that regulates the actin cytoskeleton and plays crucial roles in cancer metastasis. Up-regulated cortactin is correlated with the metastatic capacity of prostate cancer cells. AHCC^®, a standardized extract of cultured Lentinula edodes mycelia, has been previously reported to have cortactin-down-regulating effects on human pancreatic cancer cells. In the present study, the effects of AHCC^® treatment on cortactin levels in prostate cancer cells was evaluated.

MATERIALS AND METHODS

LNCaP.FGC, DU145, and PC-3 are human prostate cancer cell lines. LNCaP.FGC is well differentiated, androgen-dependent, and poorly metastatic. DU145 is less differentiated, androgen-independent, and moderate metastatic. PC-3 is less differentiated, androgen-independent, and highly metastatic. The effects of AHCC^® treatment on cortactin levels in prostate cancer cells was evaluated by western blot.

RESULTS

In vitro AHCC^® treatment decreased cortactin levels in LNCaP.FGC and DU145 cells but did not change those in PC-3 cells.

CONCLUSION

AHCC^® treatment down-regulated cortactin expression in poor and moderate metastatic LNCaP.FGC and DU145 cells but showed no effect on cortactin expression in the highly metastatic PC-3 cells. Further studies are required to elucidate the mechanism of the resistance to AHCC^® treatment in highly metastatic PC-3 cells.

Short-hairpin RNA-mediated suppression of cortactin may inhibit the migration and invasion abilities of endometrial cancer cells by reducing lamellipodia

Objectives

The prognosis of endometrial cancer (EC) is significantly affected by tumor infiltration and metastasis. Cortactin (CTTN) regulates infiltration and metastasis in other tumors. Studies on the role and mechanism of CTTN in EC are limited and further studies are needed.

Materials and Methods

Quantitative PCR and immunohistochemistry were used to detect Ras-associated C3 botulinum toxin substrate 1 (Rac1) and CTTN in EC and normal tissues. The relationship between the expression of these two genes and their prognostic factors was analyzed. A CTTN-RNAi lentiviral system was constructed and transfected into EC cells. Migration and invasion were evaluated by scratch assay, transwell migration, and invasion assays. Pseudopodia formation was observed by immunofluorescence staining. Western blotting was performed to detect the expression of Rac1.

Results

The expression levels of Rac1 and CTTN in EC tissues were significantly higher than those in normal tissues. In the EC group, Rac1 and CTTN levels were correlated. The protein expression levels of Rac1 and CTTN were related to myometrial invasion and stage. After CTTN knockdown, the migration rate, invasiveness, and migratory ability of EC cells decreased significantly. Lamellipodia was observed to disappear with the appearance of blebs. Rac1 protein expression was decreased after CTTN knockdown.

Conclusion

CTTN may promote the invasion and migration of EC by lamellipodia. This effect may be related to the regulation of Rac1 by CTTN.

Gastric Epithelial Barrier Disruption, Inflammation and Oncogenic Signal Transduction by Helicobacter pylori

Helicobacter pylori exemplifies one of the most favourable bacterial pathogens worldwide. The bacterium colonizes the gastric mucosa in about half of the human population and constitutes a major risk factor for triggering gastric diseases such as stomach cancer. H. pylori infection represents a prime example of chronic inflammation and cancer-inducing bacterial pathogens. The microbe utilizes a remarkable set of virulence factors and strategies to control cellular checkpoints of inflammation and oncogenic signal transduction. This chapter emphasizes on the pathogenicity determinants of H. pylori such as the cytotoxin-associated genes pathogenicity island (cagPAI)-encoded type-IV secretion system (T4SS), effector protein CagA, lipopolysaccharide (LPS) metabolite ADP-glycero-β-D-manno-heptose (ADP-heptose), cytotoxin VacA, serine protease HtrA, and urease, and how they manipulate various key host cell signaling networks in the gastric epithelium. In particular, we highlight the H. pylori-induced disruption of cell-to-cell junctions, pro-inflammatory activities, as well as proliferative, pro-apoptotic and anti-apoptotic responses. Here we review these hijacked signal transduction events and their impact on gastric disease development.

Cortactin: A universal host cytoskeletal target of Gram-negative and Gram-positive bacterial pathogens

Pathogenic bacteria possess a great potential of causing infectious diseases and represent a serious threat to human and animal health. Understanding the molecular basis of infection development can provide new valuable strategies for disease prevention and better control. In host-pathogen interactions, actin-cytoskeletal dynamics play a crucial role in the successful adherence, invasion, and intracellular motility of many intruding microbial pathogens. Cortactin, a major cellular factor that promotes actin polymerization and other functions, appears as a central regulator of host-pathogen interactions and different human diseases including cancer development. Various important microbes have been reported to hijack cortactin signaling during infection. The primary regulation of cortactin appears to proceed via serine and/or tyrosine phosphorylation events by upstream kinases, acetylation, and interaction with various other host proteins, including the Arp2/3 complex, filamentous actin, the actin nucleation promoting factor N-WASP, focal adhesion kinase FAK, the large GTPase dynamin-2, the guanine nucleotide exchange factor Vav2, and the actin-stabilizing protein CD2AP. Given that many signaling factors can affect cortactin activities, several microbes target certain unique pathways, while also sharing some common features. Here we review our current knowledge of the hallmarks of cortactin as a major target for eminent Gram-negative and Gram-positive bacterial pathogens in humans.

Respiratory syncytial virus disrupts the airway epithelial barrier by decreasing cortactin and destabilizing F-actin

Respiratory syncytial virus (RSV) infection is the leading cause of acute lower respiratory tract infection in young children worldwide. Our group recently revealed that RSV infection disrupts the airway epithelial barrier in vitro and in vivo. However, the underlying molecular pathways were still elusive. Here, we report the critical roles of the filamentous actin (F-actin) network and actin-binding protein cortactin in RSV infection. We found that RSV infection causes F-actin depolymerization in 16HBE cells, and that stabilizing the F-actin network in infected cells reverses the epithelial barrier disruption. RSV infection also leads to significantly decreased cortactin in vitro and in vivo. Cortactin-knockout 16HBE cells presented barrier dysfunction, whereas overexpression of cortactin protected the epithelial barrier against RSV. The activity of Rap1 (which has Rap1A and Rap1B forms), one downstream target of cortactin, declined after RSV infection as well as in cortactin-knockout cells. Moreover, activating Rap1 attenuated RSV-induced epithelial barrier disruption. Our study proposes a key mechanism in which RSV disrupts the airway epithelial barrier via attenuating cortactin expression and destabilizing the F-actin network. The identified pathways will provide new targets for therapeutic intervention toward RSV-related disease. This article has an associated First Person interview with the first author of the paper.

Syntaxin 7 contributes to breast cancer cell invasion by promoting invadopodia formation

Invasion in various cancer cells requires coordinated delivery of signaling proteins, adhesion proteins, actin-remodeling proteins and proteases to matrix-degrading structures called invadopodia. Vesicular trafficking involving SNAREs plays a crucial role in the delivery of cargo to the target membrane. Screening of 13 SNAREs from the endocytic and recycling route using a gene silencing approach coupled with functional assays identified syntaxin 7 (STX7) as an important player in MDA-MB-231 cell invasion. Total internal reflection fluorescence microscopy (TIRF-M) studies revealed that STX7 resides near invadopodia and co-traffics with MT1-MMP (also known as MMP14), indicating a possible role for this SNARE in protease trafficking. STX7 depletion reduced the number of invadopodia and their associated degradative activity. Immunoprecipitation studies revealed that STX7 forms distinct SNARE complexes with VAMP2, VAMP3, VAMP7, STX4 and SNAP23. Depletion of VAMP2, VAMP3 or STX4 abrogated invadopodia formation, phenocopying what was seen upon lack of STX7. Whereas depletion of STX4 reduced MT1-MMP level at the cell surfaces, STX7 silencing significantly reduced the invadopodia-associated MT1-MMP pool and increased the non-invadosomal pool. This study highlights STX7 as a major contributor towards the invadopodia formation during cancer cell invasion. This article has an associated First Person interview with the first author of the paper.

PLXDC2 enhances invadopodium formation to promote invasion and metastasis of gastric cancer cells via interacting with PTP1B

Plexin-domain containing 2 (PLXDC2) has been reported as an oncoprotein in several human malignancies. However, its expression and roles in gastric cancer remain largely unclear. In this study, we found that PLXDC2 was highly expressed in gastric cancer tissues, and the expression levels were positively correlated with clinicopathological features, but negatively with the patients’ outcome. Cox regression analysis identified PLXDC2 as an independent prognostic indicator for the patients. Knockdown of PLXDC2 markedly suppressed the in vitro invasion and in vivo metastasis of gastric cancer cells, while overexpression of PLXDC2 resulted in opposite effects. Mechanistically, PLXDC2 enhanced the level of phosphorylated Cortactin (p-Cortactin) by physically interacting with protein tyrosine phosphatase 1B (PTP1B), an important dephosphorylase, to prevent its dephosphorylating of p-Cortactin, thereby promoting the formation of invadopodia. Collectively, our results indicate that PLXDC2 contributes to the invasion and metastasis of gastric cancer by inhibiting PTP1B to facilitate the invadopodium formation, and may serve as a potential prognostic biomarker and a therapeutic target for this disease.

Dietary patterns in association with the expression of pro-metastatic genes in primary breast cancer

PURPOSE

Metastasis is a major leading cause of mortality in female breast cancer (BrCa). Cellular motility is a pathological process of metastasis remarked by the overexpression of cortactin (CTTN), Ras homolog family member-A (RhoA), and Rho-associated kinase (ROCK) genes. Their balance is responsible for upholding the integrity of healthy epithelial cell junctions. This study aimed to explore the associations between a posteriori dietary patterns and the expression levels of pro-metastatic genes in primary BrCa.

METHODS

In this consecutive case series, 215 eligible women, newly diagnosed with histologically confirmed non-metastatic BrCa (stage I-IIIA), were recruited from Hospitals in Tabriz, Northwestern Iran (2015-2017). The tumoral expression levels of genes were quantified using real-time reverse transcription-polymerase chain reaction. Dietary data assessment was carried out using a validated food frequency questionnaire.

RESULTS

Three dietary patterns were identified using principal component analysis (KMO = 0.699). Adherence to the "vegan" pattern (vegetables, fruits, legumes, nuts, seeds, and whole grains) was inversely associated with the expression levels of RhoA (OR_Adj.T3vs.T1 = 0.24, 95%CI 0.07-0.79) and ROCK (OR_Adj.T3vs.T1 = 0.26, 95%CI 0.08-0.87). In addition, the highest adherence to the "prudent" pattern (spices, seafood, dairy, and vegetable oils) decreased the odds of overexpressions at RhoA (OR_Adj.T3vs.T1 = 0.26, 95%CI 0.08-0.84) and ROCK genes (OR_Adj.T3vs.T1 = 0.29, 95%CI 0.09-0.95). The highest adherence to "Western" pattern (meat, processed meat, hydrogenated fat, fast food, refined cereals, sweets, and soft drinks) was a risk factor associated with the overexpression of RhoA (OR_Adj.T3vs.T1 = 3.15, 95%CI 1.12-8.85).

CONCLUSION

Adherence to healthy dietary patterns was significantly associated with the downregulation of pro-metastatic genes. Findings provided new implications to advance the nutrigenomic knowledge to prevent the odds of over-regulations in pro-metastatic genes of the primary BrCa.

[The expression of cortactin in colorectal cancer and its relationship with clinicopathological and prognostic parameters]

Objective: To investigate the expression of cortactin in colorectal cancer and its correlation with clinicopathological parameters and prognosis. Methods: The expressions of cortactin in normal colorectal mucosal tissue and colorectal cancer tissue in paraffin-embedded tissue microarray from 319 patients who were diagnosed as colorectal cancer and treated in Cancer Hospital of Chinese Academy of Medical Sciences from 2006 to 2009 was detected by immunohistochemistry. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox proportional risk regression model was used for multivariate analysis. Results: The positive expression rates of cortactin in colorectal cancer tissue and normal colorectal mucosal tissue were 61.1% (195/319) and 5.6% (18/319, P<0.001), respectively. T-stage, N-stage, American Joint Committee on Cancer (AJCC) stage, degree of tumor differentiation, neural invasion and preoperative carcinoembryonic antigen (CEA) levels were associated with the expression of cortactin (P<0.05). The positive expression of cortactin was associated with poorer disease-free survival (P=0.036) and overall survival (P=0.043), and the effect was more significant in patients with stage Ⅱ to Ⅲ. For patients with stage Ⅱ-Ⅲ colorectal cancer, postoperative adjuvant therapy was associated with disease-free survival (P=0.007) and overall survival (P=0.015). The vascular tumor embolus, pathological type, preoperative CEA level and cortactin expression were independent influencing factors for disease-free survival (P<0.05). The age, AJCC stage, preoperative CEA level and cortactin expression were independent influencing factors for overall survival (P<0.05). Preoperative CEA level and cortactin expression were independent influencing factors for disease-free survival and overall survival (P<0.05). Conclusion: Cortactin is expressed in colorectal cancer and in stage Ⅱ-Ⅲ patients, it is a potential predictor of colorectal cancer prognosis.

[Mechanism study of the protective effects of selective cyclooxygenase-2 enzyme inhibitors on the liver of rats with type 2 diabetes mellitus combined with nonalcoholic steatohepatitis via Rho/ROCK pathway]

Objective: To investigate whether the selective cyclooxygenase-2 enzyme inhibitors celecoxib has protective effect on the liver of rats with type 2 diabetes mellitus (T2DM) combined with nonalcoholic steatohepatitis (NASH) via inhibiting the expression of Rho/ROCK pathway. Methods: Forty male SD rats were randomly divided into four groups: type 2 diabetes mellitus combined with nonalcoholic steatohepatitis (T2DM-NASH) group, T2DM-NASH + celecoxib group, control group, and control+celecoxib group. The T2DM-NASH and T2DM-NASH + celecoxib groups were fed with high-sugar and fat diet, and the control group and control + celecoxib group were fed with basal diet (25 kJ/kg). Four weeks later, streptozotocin (STZ, 30 mg/kg) was intraperitoneally injected into the NASH group and T2DM-NASH + celecoxib group to induce T2DM model, and the control group and control + celecoxib group were intraperitoneally injected with isovolumic citric acid-sodium citrate buffer. Four weeks after STZ injection, the T2DM-NASH + celecoxib group and the control + celecoxib group were gavaged with celecoxib (10 mg·kg·d) dissolved in normal saline for 4 weeks, and the remaining two groups of rats were gavaged with isovolumic normal saline for 4 weeks. Animals were sacrificed at the end of the 12- weeks, and the liver tissue was collected. Liver pathological changes were observed by HE staining. The expressions of RhoA, RhoA, ROCK1 and ROCK2 proteins in liver were detected by immunohistochemistry and western blot. The expressional condition of RhoA, ROCK1 and ROCK2 mRNA in liver were detected by real-time quantitative PCR. The differences were compared between protein and mRNA expression among the groups by analysis of variance and t-test. Results: Compared with the control group and the control + celecoxib group, the liver tissue of the T2DM-NASH group and the T2DM-NASH + celecoxib group had severe steatosis, and there was partial inflammatory cell infiltration under the light microscope. The expression levels of RhoA, ROCK1 and ROCK2 protein and mRNA were significantly increased (P < 0.05) in each liver tissue, while liver steatosis was reduced to certain extent in T2DM-NASH + celecoxib group than T2DM-NASH group, and the expression levels of RhoA, ROCK1 and ROCK2 protein and mRNA were decreased in each liver tissue of T2DM-NASH group (P < 0.05). Conclusion: The selective cyclooxygenase-2 enzyme inhibitors celecoxib has a protective effect on the liver of rats with T2DM-NASH, and its effect may be achieved by inhibiting the expression of Rho/ROCK pathway.

[Effects of adenovirus-mediated shRNA down-regulates PTEN expression on fibril-binding proteins vinculin, filamin A and cortactin in activated hepatic stellate cells]

Objective: To investigate the effect of adenovirus-mediated shRNA down-regulating phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on vinculin, filamin A, and cortactin in activated hepatic stellate cells (HSCs). Methods: Activated rats hepatic stellate cell line (HSC-T6) was cultured in vitro. Recombinant adenovirus Ad-shRNA/PTEN carrying PTEN targeted RNA interference sequence [short hairpin RNA (shRNA)] and empty control virus Ad-GFP were transfected into HSCs. The PTEN mRNA and protein expression of HSCs in each group were detected by real-time fluorescence quantitative PCR and Western blot. The expressional change of vinculin, filamin A and cortactin in HSCs of each group were detected by confocal laser scanning immunofluorescence microscope. Image-pro plus 6.0 software was used for image analysis and processing. The integrated optical density (IOD) of the fluorescence protein expression was measured. The experiment was divided into three groups: control group (DMEM instead of adenovirus solution in the adenovirus transfection step), Ad-GFP group (transfected with empty virus Ad-GFP only expressing green fluorescent protein), and Ad-shRNA/PTEN group (recombinant adenovirus Ad-shRNA/PTEN carrying shRNA targeting PTEN and expressing green fluorescent protein). One-way analysis of variance was used for comparison of mean value among the three groups, and LSD-test was used for comparison between the groups. Results: shRNA targeted PTEN was successfully transfected and the expression of PTEN mRNA and protein in HSC (P < 0.05) was significantly down-regulated. HSCs vinculin was mainly expressed in the cytoplasm. HSCs vinculin fluorescence IOD in the Ad-shRNA/PTEN group (19 758.83 ± 1 520.60) was higher than control (7 737.16 ± 279.93) and Ad-GFP group (7 725.50 ± 373.03) (P < 0.05), but there was no statistically significant difference between control group and Ad-GFP group (P > 0.05). There was no statistically significant difference in the fluorescence IOD of Filamin A among the three groups (P > 0.05), but the subcellular distribution of Filamin A among the three groups were changed. Filamin A in the Ad-shrNA /PTEN HSC group was mainly distributed in the cytoplasm. Filamin A HSC was mainly located in the nucleus.The filamin A HSC in the control group and Ad-GFP group was mainly located in the nucleus. The nucleocytoplasmic ratio of Filamin A in the AD-shrNA /PTEN group (0.60 ± 0.15) was significantly lower than control group (1.20 ± 0.15) and Ad-GFP group (1.08 ± 0.23), P < 0.05. but there was no statistically significant difference in filamin A nucleocytoplasmic ratio of HSC between the control group and the Ad-GFP group (P > 0.05). Cortactin HSCs in the three groups was mainly distributed in the cytoplasm. The cortactin fluorescence IOD of HSCs in the Ad-shRNA/PTEN group was significantly higher than control group (22 959.94 ± 1 710.42) and the Ad-GFP group (22 547.11 ± 1 588.72 ) (P < 0.05), while there was no statistically significant difference in the IOD of cortactin fluorescence in HSCs between the control group and the Ad-GFP group (P > 0.05). Conclusion: The down-regulation of PTEN expression raises the expression of microfilament-binding protein vinculin and cortactin, and changes the subcellular distribution of another microfilament binding protein filamin A, that is, translocation from nucleus to the cytoplasm in activated HSC in vitro.

A Co-purification Method for Efficient Production and Src Kinase-mediated Phosphorylation of Aplysia Cortactin

Cortactin is an actin-binding protein that regulates processes like cell migration, endocytosis, and tumor cell metastasis. Although cortactin is associated with actin-cytoskeletal dynamics in non-neuronal cells and cell-free systems, the exact mechanisms underlying its fundamental roles in neuronal growth cones are not fully explored. Recent reports show that Aplysia Src2 tyrosine kinase induces phosphorylation of cortactin as a mechanism to control lamellipodia protrusion and filopodia formation in cultured Aplysia bag cell neurons ( He et al., 2015 ; Ren et al., 2019 ). In order to provide in vitro evidence for Src2-mediated phosphorylation of cortactin, we developed a robust and cost-effective method for the efficient expression and purification of Aplysia cortactin and Src2 kinase that can be used for biochemical studies including phosphorylation assays. By co-purifying cortactin and Src kinase with a phosphatase (YopH) from Yersinia enterocolitica, we eliminated the problem of non-specific phosphorylation of induced proteins by bacterial kinases and also reduced costs by bypassing the need for commercial enzymatic treatments. This protocol is reproducible and can be modified to produce homogenous non-phosphorylated proteins during recombinant protein expression in Escherichia coli.

Cortactin and HER2 as potential markers for dural-targeted therapy in advanced gastric cancer

To study the role of HER2/cortactin co-overexpression in advanced gastric cancer (GC). This study retrospectively enrolled 246 patients with stage III GC from January 2015 to December 2016 at our hospital. We explored, using immunostaining techniques, the role of the expression of cortactin and HER2 in the progression of advanced GC. The patient data, including age, sex, cortactin and HER2 expression, pathological parameters and survival, were collected. Univariate and multivariate analyses were used to analyze the characteristics, survival, and prognostic factors of the patients. The results showed that the expression of cortactin was significantly associated with vascular-lymphatic invasion (P < 0.001), N stage (P = 0.001), and TNM stage (P = 0.046). HER2 overexpression correlated with tumor size (P = 0.002), neural invasion (P = 0.002), Lauren classification (P = 0.005) and N stage (P = 0.034). Through univariate analysis using the Kaplan-Meier method, vascular-lymphatic invasion (P = 0.015), neural invasion (P = 0.021), N stage (P < 0.003), and HER2/cortactin co-overexpression (P < 0.028) were shown to be significantly associated with overall survival. Multivariate analysis demonstrated that vascular lymphatic invasion (hazard ratio = 1.481, 95% CI, 1.064 to 2.061, P = 0.020), neural invasion (hazard ratio = 1.505, 95% CI, 1.084 to 2.089, P = 0.015), N stage (N2/N1: hazard ratio = 1.655, 95% CI, 1.048 to 2.641, P < 0.031, N3/N1: hazard ratio = 2.089, 95% CI, 1.325 to 3.295, P < 0.002), and HER2/cortactin co-overexpression (hazard ratio = 1.427, 95% CI, 1.007 to 2.024, P = 0.046) were independent prognostic factors for poor overall survival. The results suggested that HER2/cortactin co-overexpression is an important predictive biomarker for GC patients. GC patients with HER2/cortactin co-overexpression may receive dual-targeted therapy to improve survival prognosis in the future.

A comparative immunohistochemical analysis of cortactin in orthokeratinized odontogenic cyst (OOC), sporadic odontogenic keratocyst (OKC), and syndromic OKC

OBJECTIVES

To evaluate and compare the immunohistochemical expression of cortactin in the epithelial lining of orthokeratinized odontogenic cyst (OOC), sporadic odontogenic keratocyst (OKC), and syndromic OKC.

METHODS

Formalin-fixed paraffin-embedded tissue blocks of histopathologically diagnosed cases of OOC, OKC, syndromic OKC, normal buccal mucosa (NBM), and oral squamous cell carcinoma (OSCC) were examined for immunohistochemical expression of cortactin. Clear brown cytoplasmic and membranous staining was considered positive.

RESULTS

A statistically significant difference was observed between OOC and syndromic OKC (p<0.001), as well as between sporadic OKC and syndromic OKC (p<0.001). Although not statistically significant, the expression of cortactin was slightly higher in the basal layer of NBM (mean=0.47), OOC (mean=0.27), sporadic OKC (mean=0.47) syndromic OKC (mean=1.53), and OSCC (mean=0.67) than in the parabasal layers of NBM (mean=0.27), OOC (mean=0.20), sporadic OKC (mean=0.47), syndromic OKC (mean=1.27), and OSCC (mean=0.60).

CONCLUSION

The expression of cortactin in the basal layer may suggest the formation of invadopodia in the basal layer where the invasion mechanism occurs. This finding is further supported by the higher localization of cortactin in areas of epithelial budding and daughter cysts in syndromic OKC, thereby reaffirming its possible association with recurrence.