Cortactin overexpression regulates actin-related protein 2/3 complex activity, motility, and invasion in carcinomas with chromosome 11q13 amplification

Stiffness promotes cell migration, invasion, and invadopodia in nasopharyngeal carcinoma by regulating the WT-CTTN level

Matrix stiffness potently promotes the malignant phenotype in various biological contexts. Therefore, identification of gene expression to participate in mechanical force signals transduced into downstream biochemical signaling will contribute substantially to the advances in nasopharyngeal carcinoma (NPC) treatment. In the present study, we detected that cortactin (CTTN) played an indispensable role in matrix stiffness-induced cell migration, invasion, and invadopodia formation. Advances in cancer research have highlighted that dysregulated alternative splicing contributes to cancer progression as an oncogenic driver. However, whether WT-CTTN or splice variants (SV1-CTTN or SV2-CTTN) regulate matrix stiffness-induced malignant phenotype is largely unknown. We proved that alteration of WT-CTTN expression modulated matrix stiffness-induced cell migration, invasion, and invadopodia formation. Considering that splicing factors might drive cancer progression through positive feedback loops, we analyzed and showed how the splicing factor PTBP2 and TIA1 modulated the production of WT-CTTN. Moreover, we determined that high stiffness activated PTBP2 expression. Taken together, our findings showed that the PTBP2-WT-CTTN level increases upon stiffening and then promotes cell migration, invasion, and invadopodia formation in NPC.

An overview of the co-transcription factor NACC1: Beyond its pro-tumor effects

Nucleus accumbens-associated protein 1 (NACC1) is a member of the broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) protein families, mainly exerting its biological functions as a transcription co-regulator. NACC1 forms homo- or hetero-dimers through the BTB/POZ or BANP, E5R, and NACC1 (BEN) domain with other transcriptional regulators to regulate downstream signals. Recently, the overexpression of NACC1 has been observed in various tumors and is positively associated with tumor progression, high recurrence rate, indicating poor prognosis. NACC1 also regulates biological processes such as embryonic development, stem cell pluripotency, innate immunity, and related diseases. Our review combines recent research to summarize advancements in the structure, biological functions, and relative molecular mechanisms of NACC1. The future development of NACC1 clinical appliances is also discussed.

Human amniotic membrane inhibits migration and invasion of muscle-invasive bladder cancer urothelial cells by downregulating the FAK/PI3K/Akt/mTOR signalling pathway

Bladder cancer is the 10th most commonly diagnosed cancer with the highest lifetime treatment costs. The human amniotic membrane (hAM) is the innermost foetal membrane that possesses a wide range of biological properties, including anti-inflammatory, antimicrobial and anticancer properties. Despite the growing number of studies, the mechanisms associated with the anticancer effects of human amniotic membrane (hAM) are poorly understood. Here, we reported that hAM preparations (homogenate and extract) inhibited the expression of the epithelial-mesenchymal transition markers N-cadherin and MMP-2 in bladder cancer urothelial cells in a dose-dependent manner, while increasing the secretion of TIMP-2. Moreover, hAM homogenate exerted its antimigratory effect by downregulating the expression of FAK and proteins involved in actin cytoskeleton reorganisation, such as cortactin and small RhoGTPases. In muscle-invasive cancer urothelial cells, hAM homogenate downregulated the PI3K/Akt/mTOR signalling pathway, the key cascade involved in promoting bladder cancer. By using normal, non-invasive papilloma and muscle-invasive cancer urothelial models, new perspectives on the anticancer effects of hAM have emerged. The results identify new sites for therapeutic intervention and are prompt encouragement for ongoing anticancer drug development studies.

Engineered cell-overexpression of circular RNA hybrid hydrogels promotes healing of calvarial defects

Craniomaxillofacial bone defects seriously affect the physical and mental health of patients. Bone marrow mesenchymal stem cells (BMSCs) are "gold standard" cells used for bone repair. However, the collection of BMSCs is invasive, and the osteogenic capacity is limited with age. Human umbilical cord mesenchymal stem cells (hUCMSCs) are promising alternative seed cells for bone tissue engineering. Our group previously used high-throughput sequencing technology and bioinformatics methods to detect circ-CTTN (hsa-circ_0003376) molecules, which may play an essential role in the osteogenic differentiation of hUCMSCs. In this study, osteogenic induction in vitro showed that the overexpressing circ-CTTN (OE group) exhibits a more pronounced osteogenic phenotype. The levels of osteogenesis-related genes in the OE group were highly expressed. The gelatin-methacrylate (GelMA) hydrogel possessed excellent biocompatibility and was used to load hUCMSCs. In the rat calvarial defect, the OE group presented a larger bone healing volume and denser bone trabecular distribution than other groups. So far, the overexpression of circ-CTTN could enhance the osteogenic differentiation of hUCMSCs and accelerate bone reconstruction. Our research could provide a new strategy and a strong theoretical basis for promoting hUCMSC clinical application in bone tissue engineering.

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.

A prognostic biomarker study in patients with clinical stage I esophageal squamous cell carcinoma: JCOG0502-A1

We conducted genomic analyses of Japanese patients with stage I esophageal squamous cell carcinoma (ESCC) to investigate the frequency of genomic alterations and the association with survival outcomes. Biomarker analysis was conducted for patients with clinical stage T1bN0M0 ESCC enrolled in JCOG0502 (UMIN000000551). Whole-exome sequencing (WES) was performed using DNA extracted from formalin-fixed, paraffin-embedded tissue of ESCC and normal tissue or blood sample. Single nucleotide variants (SNVs), insertions/deletions (indels), and copy number alterations (CNAs) were identified. We then evaluated the associations between each gene alteration with a frequency ≥10% and progression-free survival (PFS) using a Cox regression model. We controlled for family-wise errors at 0.05 using the Bonferroni method. Among the 379 patients who were enrolled in JCOG0502, 127 patients were successfully analyzed using WES. The median patient age was 63 years (IQR, 57-67 years), and 78.0% of the patients ultimately underwent surgery. The 3-year PFS probability was 76.3%. We detected 20 genes with SNVs, indels, or amplifications with a frequency of ≥10%. Genomic alterations in FGF19 showed the strongest association with PFS with a borderline level of statistical significance of p = 0.00252 (Bonferroni-adjusted significance level is 0.0025). Genomic alterations in FGF4, MYEOV, CTTN, and ORAOV1 showed a marginal association with PFS (p < 0.05). These genomic alterations were all CNAs at chromosome 11q13.3. We have identified new genomic alterations associated with the poor efficacy of ESCC (T1bN0M0). These findings open avenues for the development of new potential treatments for patients with ESCC.

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.

Cortactin expression assessment improves patient selection for a watchful waiting strategy in pT1cN0-staged oral squamous cell carcinomas with a tumor infiltration depth below 4 mm

BACKGROUND

In this feasibility study we aimed to evaluate the value of previously reported molecular tumor biomarkers associated with lymph node metastasis in oral squamous cell carcinoma (OSCC) to optimize neck strategy selection criteria.

METHODS

The association between expression of cortactin, cyclin D1, FADD, RAB25, and S100A9 and sentinel lymph node status was evaluated in a series of 87 (cT1-2N0) patients with OSCC treated with primary resection and SLNB procedure.

RESULTS

Tumor infiltration depth and tumor pattern of invasion were independent prognostic markers for SLN status, while none of the tumor makers showed a better prognostic value to replace SLNB as neck staging technique in the total cohort. However, in the subgroup of patients with pT1N0 OSCC, cortactin expression (OR 16.0, 95%CI 2.0-127.9) was associated with SLN classification.

CONCLUSIONS

Expression of cortactin is a promising immunohistochemical tumor marker to identify patients at low risk that may not benefit from SLNB or END.

Key proteins of invadopodia are overexpressed in oral squamous cell carcinoma suggesting an important role of MT1-MMP in the tumoral progression

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most relevant malignant neoplasm among all head and neck tumours due to its high prevalence and unfavourable prognosis. Tumour invasion and metastasis that affect prognosis are result of a set of complex events that cells with invasive potential use to spread to other regions. These cells use several mechanisms to invade tissues, including a type of finger-like membrane protrusion called invadopodia. This study aims to investigate the immunoexpression of invaopodia related-proteins TKs5, cortactin, TKs4 and MT1-MMP in OSCC and correlate it to clinicopathological data.

METHODS

An immunohistochemical evaluation of fifty cases of OSCCs and 20 cases of oral mucosa (OM) were assessed. The expression of invadopodia proteins were analysed in comparison to normal tissue (OM) and correlated to different clinical-stage and histological grade of OSCC.

RESULTS

TKs5, cortactin, TKs4 and MT1-MMP were significantly overexpressed in OSCC when compared to OM (p < 0.0001). Among tumour stages, TKs5 showed a statistical difference in immunolabelling between stage I and III (p = 0.026). Cortactin immunolabelling was statistically higher in grade I than in grade II and III. No differences were seen on TKs4 expression based on tumour staging or grading. MT1-MMP was higher expressed and showed statistical difference between stages I and III and grades I compared to II and III.

CONCLUSIONS

The invadopodia related-proteins were found to be overexpressed in OSCC when compared to OM, suggesting invadopodia formation and activity. Besides overexpressed in OSCC, cortactin, TKs4 and TKs5 showed no or ambiguous differences in protein expression when compared among clinical-stages or histological grades groups. Conversely, the expression of MT1-MMP increased in advanced stages and less differentiated tumours, suggesting MT1-MMP expression as a promising prognostic marker in OSCC.

Profiling the expression of pro-metastatic genes in association with the clinicopathological features of primary breast cancer

BACKGROUND

Metastasis accounts for ninety percent of breast cancer (BrCa) mortality. Cortactin, Ras homologous gene family member A (RhoA), and Rho-associated kinase (ROCK) raise cellular motility in favor of metastasis. Claudins (CLDN) belong to tight junction integrity and are dysregulated in BrCa. Thus far, epidemiologic evidence regarding the association of different pro-metastatic genes with pathological phenotypes of BrCa is largely inconsistent. This study aimed to determine the possible transcriptional models of pro-metastatic genes incorporate in holding the integrity of epithelial cell-cell junctions (CTTN, RhoA, ROCK, CLDN-1, CLDN-2, and CLDN-4), for the first time, in association with clinicopathological features of primary BrCa.

METHODS

In a consecutive case-series design, 206 newly diagnosed non-metastatic eligible BrCa patients with histopathological confirmation (30-65 years) were recruited in Tabriz, Iran (2015-2017). Real-time RT-PCR was used. Then fold changes in the expression of target genes were measured.

RESULTS

ROCK amplification was associated with the involvement of axillary lymph node metastasis (ALNM; ORadj. = 3.05, 95%CI 1.01-9.18). Consistently, inter-correlations of CTTN-ROCK (β = 0.226, P < 0.05) and RhoA-ROCK (β = 0.311, P < 0.01) were determined among patients diagnosed with ALNM+ BrCa. In addition, the overexpression of CLDN-4 was frequently observed in tumors identified by ALNM+ or grade III (P < 0.05). The overexpression of CTTN, CLDN-1, and CLDN-4 genes was correlated positively with the extent of tumor size. CTTN overexpression was associated with the increased chance of luminal-A positivity vs. non-luminal-A (ORadj. = 1.96, 95%CI 1.02-3.77). ROCK was also expressed in luminal-B BrCa tumors (P < 0.05). The estrogen receptor-dependent transcriptions were extended to the inter-correlations of RhoA-ROCK (β = 0.280, P < 0.01), ROCK-CLDN-2 (β = 0.267, P < 0.05), and CLDN-1-CLDN-4 (β = 0.451, P < 0.001).

CONCLUSIONS

For the first time, our findings suggested that the inter-correlations of CTTN-ROCK and RhoA-ROCK were significant transcriptional profiles determined in association with ALNM involvement; therefore the overexpression of ROCK may serve as a potential molecular marker for lymphatic metastasis. The provided binary transcriptional profiles need more approvals in different clinical features of BrCa metastasis.

Mutational drivers of cancer cell migration and invasion

Genomic instability and mutations underlie the hallmarks of cancer-genetic alterations determine cancer cell fate by affecting cell proliferation, apoptosis and immune response, and increasing data show that mutations are involved in metastasis, a crucial event in cancer progression and a life-threatening problem in cancer patients. Invasion is the first step in the metastatic cascade, when tumour cells acquire the ability to move, penetrate into the surrounding tissue and enter lymphatic and blood vessels in order to disseminate. A role for genetic alterations in invasion is not universally accepted, with sceptics arguing that cellular motility is related only to external factors such as hypoxia, chemoattractants and the rigidity of the extracellular matrix. However, increasing evidence shows that mutations might trigger and accelerate the migration and invasion of different types of cancer cells. In this review, we summarise data from published literature on the effect of chromosomal instability and genetic mutations on cancer cell migration and invasion.

CX3 CL1 promotes tumour cell by inducing tyrosine phosphorylation of cortactin in lung cancer

It has been reported that chemokine CX3 CL1 can regulate various tumours by binding to its unique receptor CX3 CR1. However, the effect of CX3 CL1-CX3 CR1 on the lung adenocarcinoma and lung squamous cell carcinoma is still unclear. Here, we showed that CX3 CL1 can further invasion and migration of lung adenocarcinoma A549 and lung squamous cell carcinoma H520. In addition, Western blot and immunofluorescence test indicated CX3 CL1 up-regulated the phosphorylation level of cortactin, which is a marker of cell pseudopodium. Meanwhile, the phosphorylation levels of c-Src and c-Abl, which are closely related to the regulation of cortactin phosphorylation, are elevated. Nevertheless, the src/abl inhibitor bosutinib and mutations of cortactin phosphorylation site could inhibit the promotion effect of CX3 CL1 on invasion and migration of A549 and H520. Moreover, these results of MTT, Hoechst staining and Western blot suggested that CX3 CL1 had no effect on the proliferation and apoptosis of A549 and H520 in vitro. The effects of CX3 CL1 were also verified by the subcutaneous tumour formation in nude mice, which showed that it could promote proliferation and invasion of A549 in vivo. In summary, our results indicated that CX3 CL1 furthered invasion and migration in lung cancer cells partly via activating cortactin, and CX3 CL1 may be a potential molecule in regulating the migration and invasion of lung cancer.

Cortactin in Epithelial-Mesenchymal Transition

Cortactin, a member of the actin-binding protein family, plays an important role in cell movement involving the cytoskeleton, as cell movement mediated by cortactin may induce the epithelial–mesenchymal transition. Cortactin participates in tumor proliferation, migration, and invasion and other related disease processes by binding to different proteins and participating in different pathways and mechanisms that induce the occurrence of these disease processes. Therefore, this article reviews the correlations between cortactin, the actin cytoskeleton, and the epithelial–mesenchymal transition and discusses its clinical importance in tumor therapy.

Cortactin Interacts with Hepatitis C Virus Core and NS5A Proteins: Implications for Virion Assembly

Hepatitis C virus (HCV) exploits cellular proteins to facilitate viral propagation. To identify the cellular factors involved in the HCV life cycle, we previously performed protein microarray assays using either HCV nonstructural 5A (NS5A) protein or core protein as a probe. Interestingly, cellular cortactin strongly interacted with both NS5A and core. Cortactin is an actin-binding protein critically involved in tumor progression by regulating the migration and invasion of cancerous cells. Protein interaction between cortactin and NS5A or core was confirmed by coimmunoprecipitation and immunofluorescence assays. We showed that cortactin interacted with NS5A and core via the N-terminal acidic domain of cortactin. Cortactin expression levels were not altered by HCV infection. Small interfering RNA (siRNA)-mediated knockdown of cortactin dramatically decreased HCV protein expression and infectivity levels, whereas overexpression of cortactin increased viral propagation. Ectopic expression of the siRNA-resistant cortactin recovered the viral infectivity, suggesting that cortactin was specifically required for HCV propagation. We further showed that cortactin was involved in the assembly step without affecting viral entry, HCV internal ribosome entry site (IRES)-mediated translation, and the replication steps of the HCV life cycle. Of note, silencing of cortactin markedly reduced both NS5A and core protein levels on the lipid droplets (LDs), and this effect was reversed by the overexpression of cortactin. Importantly, NS5A and core promoted cell migration by activating the phosphorylation of cortactin at tyrosine residues 421 and 466. Taken together, these data suggest that cortactin is not only involved in HCV assembly but also plays an important role in the cell migration.IMPORTANCE Cortactin is a cytoskeletal protein that regulates cell migration in response to a number of extracellular stimuli. The functional involvement of cortactin in the virus life cycle is not yet fully understood. The most significant finding is that cortactin strongly interacted with both hepatitis C virus (HCV) core and NS5A. Cortactin is involved in HCV assembly by tethering core and NS5A on the lipid droplets (LDs) with no effect on LD biogenesis. It was noteworthy that HCV NS5A and core activated cortactin by phosphorylation at tyrosines 421 and 466 to regulate cell migration. Collectively, our study shows that cortactin is a novel host factor involved in viral production and HCV-associated pathogenesis.

Genome-wide copy number variation analysis identified ANO1 as a novel oncogene and prognostic biomarker in esophageal squamous cell cancer

Copy number variations (CNVs) represent one of the most common genomic alterations. This study aimed to evaluate the roles of genes within highly aberrant genome regions in the prognosis of esophageal squamous cell cancer (ESCC). Exome sequencing data from 81 paired ESCC tissues were used to screen aberrant genomic regions. The associations between CNVs and gene expression were evaluated using gene expression data from the same individuals. Then, an RNA expression array profile from 119 ESCC samples was adopted for differential gene expression and prognostic analyses. Two independent ESCC cohorts with 315 subjects were further recruited to validate the prognostic value using immunohistochemistry tests. Finally, we explored the potential mechanism of our identified novel oncogene in ESCC. In total, 2003 genes with CNVs were observed, of which 76 genes showed recurrent CNVs in more than three samples. Among them, 32 genes were aberrantly expressed in ESCC tumor tissues and statistically correlated with CNVs. Strikingly, 4 (CTTN, SHANK2, INPPL1 and ANO1) of the 32 genes were significantly associated with the prognosis of ESCC patients. Patients with a positive expression of ANO1 had a poorer prognosis than ANO1 negative patients (overall survival rate: 42.91% versus 26.22% for ANO1-/+ samples, P < 0.001). Functionally, ANO1 promoted ESCC cell proliferation, migration and invasion by activating transforming growth factor-β pathway. Knockdown of ANO1 significantly inhibited tumor progression in vitro and in vivo. In conclusion, ANO1 is a novel oncogene in ESCC and may serve as a prognostic biomarker for ESCC.

Hypermethylation of UCHL1 Promotes Metastasis of Nasopharyngeal Carcinoma by Suppressing Degradation of Cortactin (CTTN)

Epigenetic regulation plays an important role in the development and progression of nasopharyngeal carcinoma (NPC), but the epigenetic mechanisms underlying NPC metastasis remain poorly understood. Here, we demonstrate that hypermethylation of the UCHL1 promoter leads to its downregulation in NPC. Restoration of UCHL1 inhibited the migration and invasion of NPC cells in vitro and in vivo, and knockdown of UCHL1 promoted NPC cell migration and invasion in vitro and in vivo. Importantly, we found that UCHL1 interacts with CTTN, and may function as a ligase promoting CTTN degradation by increasing K48-linked ubiquitination of CTTN. Additionally, restoration of CTTN in NPC cells that overexpressed UCHL1 rescued UCHL1 suppressive effects on NPC cell migration and invasion, which indicated that CTTN is a functional target of UCHL1 in NPC. Our findings revealed that UCHL1 acts as a tumor suppressor gene in NPC and thus provided a novel therapeutic target for NPC treatment.

The Drosophila protein, Nausicaa, regulates lamellipodial actin dynamics in a Cortactin-dependent manner

Drosophila CG10915 is an uncharacterized protein coding gene with sequence similarity to human Cortactin-binding protein 2 (CTTNBP2) and Cortactin-binding protein 2 N-terminal-like (CTTNBP2NL). Here, we have named this gene Nausicaa (naus) and characterize it through a combination of quantitative live-cell total internal reflection fluorescence microscopy, electron microscopy, RNAi depletion and genetics. We found that Naus co-localizes with F-actin and Cortactin in the lamellipodia of Drosophila S2R+ and D25c2 cells and this localization is lost following Cortactin or Arp2/3 depletion or by mutations that disrupt a conserved proline patch found in its mammalian homologs. Using permeabilization activated reduction in fluorescence and fluorescence recovery after photobleaching, we find that depletion of Cortactin alters Naus dynamics leading to a decrease in its half-life. Furthermore, we discovered that Naus depletion in S2R+ cells led to a decrease in actin retrograde flow and a lamellipodia characterized by long, unbranched filaments. We demonstrate that these alterations to the dynamics and underlying actin architecture also affect D25c2 cell migration and decrease arborization in Drosophila neurons. We present the hypothesis that Naus functions to slow Cortactin's disassociation from Arp2/3 nucleated branch junctions, thereby increasing both branch nucleation and junction stability.

The Pathogenic Effect of Cortactin Tyrosine Phosphorylation in Cutaneous Squamous Cell Carcinoma

BACKGROUND/AIM

Cortactin (CTTN) has been considered a promising molecular prognostic factor in various types of cancers. In this study, we aimed to investigate the role of CTTN in the pathogenesis of cutaneous squamous cell carcinoma (CSCC).

MATERIALS AND METHODS

CTTN and phospho-CTTN (p-CTTN) expression was determined in 10 healthy controls and 38 CSCC tissue samples by immunohistochemistry. The influence of CTTN on the biological behavior of CSCC cells was also investigated.

RESULTS

p-CTTN expression was significantly increased in CSCC than control samples. In contrast, no significant difference in CTTN expression was found between control and CSCC tissues. Moreover, a significant association was found between recurrence-free survival with p-CTTN expression, but not with CTTN expression. Furthermore, the proliferative, migratory, and invasive abilities of CSCC cells were significantly decreased by CTTN-siRNA transfection.

CONCLUSION

CTTN phosphorylation is strongly associated with CSCC pathogenesis and may serve as a molecular biomarker of CSCC.

The HBx-CTTN interaction promotes cell proliferation and migration of hepatocellular carcinoma via CREB1

Hepatitis B virus-encoded X protein (HBx) acts as a tumor promoter during hepatocellular carcinoma (HCC) development, probably by regulating the expression of host proteins through protein–protein interaction. A proteomics approach was used to identify HBx-interacting proteins involved in HBx-induced hepatocarcinogenesis. We validated the proteomics findings by co-immunoprecipitation and confocal microscopy. We performed cell proliferation, migration assays and cell cycle analyses in HCC cells. Finally, we confirmed the clinical significance of our findings in samples from patients. We found that cortactin (CTTN) is a novel HBx-interacting protein, and HBx regulates the expression of CTTN in the HCC cell lines MHCC-LM3 and HepG2. Mechanistically, by upregulating the expression of cAMP response element-binding protein (CREB1) and its downstream targets, such as cyclin D1 and MMP-9, the effects of the HBx-CTTN interaction on the enhancement of cellular proliferation and migration were maintained by inhibiting cell cycle arrest. In addition, we demonstrated that the levels of CTTN and CREB1 were closely correlated in clinical samples from HBV-infected patients with HCC. Overall, our data suggests that HBx contributes to cell migration and proliferation of HCC cells by interacting with CTTN and regulating the expression of CTTN and CREB1. Therefore, the HBx/CTTN/CREB1 axis is a potential novel therapeutic target in HCC.

Correlation of focal adhesion kinase expression with nodal metastasis in patients with head and neck cutaneous squamous cell carcinoma

BACKGROUND

Focal adhesion kinase (FAK) and cortactin overexpression is frequently detected in a variety of cancers, and has been associated with poor clinical outcome. However, there are no data in cutaneous squamous cell carcinoma (cSCC).

OBJECTIVE

To investigate the relationship of FAK and cortactin expression with the clinicopathologic features and the impact on the prognosis of cSCC patients.

METHODS

FAK and cortactin expression was analyzed by immunohistochemistry on paraffin-embedded tissue samples from 100 patients with cSCC, and correlated with the clinical data.

RESULTS

FAK overexpression was a significant risk factor for nodal metastasis with crude and adjusted ratios (HRs) of 2.04, (95% CI [1.08-3.86], [P = 0.029]) and 2.23 (95% CI [1.01-4.91], [P = 0.047]), respectively. Cortactin expression was not a significant risk factor for nodal metastasis.

CONCLUSION

These findings demonstrate that FAK overexpression is an independent predictor of nodal metastasis that might be helpful for risk stratification and management of patients with cSCC.

Cortactin as a potential predictor of second esophageal neoplasia in hypopharyngeal carcinoma

OBJECTIVE

Hypopharyngeal carcinoma has a very poor prognosis. The high incidence of second esophageal neoplasia is one of the major causes. To establish an efficient follow-up scheme for increasing the diagnostic yield and reducing the adverse impact of second esophageal neoplasia on survival, the purpose of this study was to explore a biomarker to predict second esophageal neoplasia.

METHODS

In this retrospective cohort study, consecutive tissue specimens from those patients who underwent tumor resection between September 2007 and October 2015 were collected. Gene amplification was performed by real-time PCR. The expression of cortactin was evaluated by immunohistochemistry. The predictive risk factors of developing second esophageal neoplasia and prognostic factors related to survival were analyzed.

RESULTS

A total of 187 patients were included with a mean follow-up of 48months (12-118months). Second esophageal tumors were found in 53 (28.3%), including 41 (21.9%) esophageal squamous cell carcinoma and 12 severe dysplasia. The results of multivariate analyses revealed that age (OR 2.81, 95% CI 1.16-6.78), cortactin overexpression (OR 2.49, 95% CI 1.17-5.33), and stage IV versus I (OR 6.49, 95% CI 1.68-25.18) were independent predictors of second esophageal neoplasia, and second esophageal neoplasia (HR 1.78, 95% CI 1.05-3.01) was an independent predictor of overall survival.

CONCLUSION

This is the first report to identify a potential biomarker for predicting second esophageal neoplasia in patients with hypopharyngeal carcinoma. In those patients with cortactin overexpression and younger age (≤60years old), close surveillance for second esophageal neoplasia is required. In addition, the real effect of cortactin overexpression on development of primary esophageal carcinoma is required to be validated in a large cohort study.

An update of knowledge on cortactin as a metastatic driver and potential therapeutic target in oral squamous cell carcinoma

Cortactin is a protein encoded by the CTTN gene, localized on chromosome band 11q13. As a result of the amplification of this band, an important event in oral carcinogenesis, CTTN is also usually amplified, promoting the frequent overexpression of cortactin. Cortactin enhances cell migration in oral cancer, playing a key role in the regulation of filamentous actin and of protrusive structures (invadopodia and lamellipodia) on the cell membrane that are necessary for the acquisition of a migratory phenotype. We also analyze a series of emerging functions that cortactin may exert in oral cancer (cell proliferation, angiogenesis, regulation of exosomes, and interactions with the tumor microenvironment). We review its molecular structure, its most important interactions (with Src, Arp2/3 complex, and SH3-binding partners), the regulation of its functions, and its specific oncogenic role in oral cancer. We explore the mechanisms of its overexpression in cancer, mainly related to genetic amplification. We analyze the prognostic implications of the oncogenic activation of cortactin in potentially malignant disorders and in head and neck cancer, where it appears to be relevant in the development of lymph node metastasis. Finally, we discuss its usefulness as a therapeutic target and suggest future research lines.

Cortactin promotes colorectal cancer cell proliferation by activating the EGFR-MAPK pathway

Cortactin (CTTN) is overexpressed in various tumors, including head and neck squamous cell carcinoma and colorectal cancer (CRC), and can serve as a biomarker of cancer metastasis. We observed that CTTN promotes cancer cell proliferation in vitro and increases CRC tumor xenograft growth in vivo. CTTN expression increases EGFR protein levels and enhances the activation of the MAPK signaling pathway. CTTN expression also inhibits the ubiquitin-mediated degradation of EGFR by suppressing the coupling of c-Cbl with EGFR. CoIP experiments indicate CTTN can interact with c-Cbl in CRC cells. These results demonstrate that CTTN promotes the proliferation of CRC cells and suppresses the degradation of EGFR.

Cytogenetic, genomic, and epigenetic characterization of the HSC-3 tongue cell line with lymph node metastasis

Oral carcinoma develops from squamous epithelial cells by the acquisition of multiple (epi) genetic alterations that target different genes and molecular pathways. Herein, we performed a comprehensive genomic and epigenetic characterization of the HSC-3 cell line through karyotyping, multicolor fluorescence in situ hybridization, array comparative genomic hybridization, and methylation-specific multiplex ligation-dependent probe amplification. HSC-3 turned out to be a near-triploid cell line with a modal number of 61 chromosomes. Banding and molecular cytogenetic analyses revealed that nonrandom gains of chromosomal segments occurred more frequently than losses. Overall, gains of chromosome 1, 3q, 5p, 7p, 8q, 9q, 10, 11p, 11q13, 12, 13, 14, 17, 18p, 20, Yp, and Xq were observed. The largest region affected by copy number loss was observed at chromosome 18q. Several of the observed genomic imbalances and their mapped genes were already associated with oral carcinoma and/or adverse prognosis, invasion, and metastasis in cancer. The most common rearrangements observed were translocations in the centromeric/near-centromeric regions. RARB, ESR1, and CADM1 genes were methylated and showed copy number losses, whereas TP73 and GATA5 presented with methylation and copy number gains. Thus, the current study presents a comprehensive characterization of the HSC-3 cell line; the use of this cell line may contribute to enriching the resources available for oral cancer research, especially for the testing of therapeutic agents.

Cortactin function in invadopodia

Actin remodeling plays an essential role in diverse cellular processes such as cell motility, vesicle trafficking or cytokinesis. The scaffold protein and actin nucleation promoting factor Cortactin is present in virtually all actin-based structures, participating in the formation of branched actin networks. It has been involved in the control of endocytosis, and vesicle trafficking, axon guidance and organization, as well as adhesion, migration and invasion. To migrate and invade through three-dimensional environments, cells have developed specialized actin-based structures called invadosomes, a generic term to designate invadopodia and podosomes. Cortactin has emerged as a critical regulator of invadosome formation, function and disassembly. Underscoring this role, Cortactin is frequently overexpressed in several types of invasive cancers. Herein we will review the roles played by Cortactin in these specific invasive structures.

The Arp2/3 Regulatory System and Its Deregulation in Cancer

The Arp2/3 complex is an evolutionary conserved molecular machine that generates branched actin networks. When activated, the Arp2/3 complex contributes the actin branched junction and thus cross-links the polymerizing actin filaments in a network that exerts a pushing force. The different activators initiate branched actin networks at the cytosolic surface of different cellular membranes to promote their protrusion, movement, or scission in cell migration and membrane traffic. Here we review the structure, function, and regulation of all the direct regulators of the Arp2/3 complex that induce or inhibit the initiation of a branched actin network and that controls the stability of its branched junctions. Our goal is to present recent findings concerning novel inhibitory proteins or the regulation of the actin branched junction and place these in the context of what was previously known to provide a global overview of how the Arp2/3 complex is regulated in human cells. We focus on the human set of Arp2/3 regulators to compare normal Arp2/3 regulation in untransformed cells to the deregulation of the Arp2/3 system observed in patients affected by various cancers. In many cases, these deregulations promote cancer progression and have a direct impact on patient survival.

Genomic profile of oral squamous cell carcinomas with an adjacent leukoplakia or with an erythroleukoplakia that evolved after the treatment of primary tumor: A report of two cases

Oral leukoplakia and erythroleukoplakia are common oral potentially malignant disorders diagnosed in the oral cavity. The specific outcome of these lesions remains to be elucidated, as their malignant transformation rate exhibits great variation. The ability to predict which of those potentially malignant lesions are likely to progress to cancer would be vital to guide their future clinical management. The present study reported two patients with tongue squamous cell carcinoma: Case study 1 was diagnosed with a simultaneous leukoplakia and case study 2 developed an erythroleukoplakia following the primary tumor treatment. Whole genome copy number alterations were analyzed using array comparative genomic hybridization. The present study determined more genomic imbalances in the tissues from leukoplakia and erythroleukoplakia compared with their respective tumors. The present study also identified in tumor and potentially malignant lesions common alterations of chromosomal regions and genes, including FBXL5, UGT2B15, UGT2B28, KANSL1, GSTT1 and DUSP22, being some of these typical aberrations described in oral cancer and others are linked to chemoradioresistance. Several putative genes associated with hallmarks of malignancy that may have an important role in predicting the progression of leukoplakia and erythroleukoplakia to squamous cell carcinoma, namely gains in BNIPL, MCL1, STAG2, CSPP1 and ZNRF3 genes were also identified.

Preventive effect of celecoxib use against cancer progression and occurrence of oral squamous cell carcinoma

Overexpression of cyclooxygenase-2 in oral cancer increases lymph node metastasis and is associated with a poor prognosis. The potential of celecoxib (CXB) use is reported in cancer treatment by inhibiting proliferation through apoptosis, but the effects on the epithelial-mesenchymal transition (EMT) and cancer cell mobility remain unclear. We performed a preclinical study and population-based study to evaluate CXB use in the prevention of oral cancer progression and occurrence. The in-vitro findings showed that CXB is involved in the inhibition of EMT and cell mobility through blocking transcription factors (Slug, Snail and ZEB1), cytoplasmic mediators (focal adhesion kinase (FAK), vimentin and β-catenin), cell adhesion molecules (cadherins and integrins), and surface receptors (AMFR and EGFR). The murine xenograft model showed a 65% inhibition in tumour growth after a 5-week treatment of CXB compared to placebo. Xenograft tumours in placebo-treated mice displayed a well-to-moderate/moderate differentiated SCC grade, while those from CXB-treated mice were well differentiated. The expression levels of membrane EGFR, and nuclear FAK, Slug and ZEB1 were decreased in the xenograft tumours of CXB-treated mice. A retrospective cohort study showed that increasing the daily dose and medication time of CXB was associated with oral cancer prevention. The findings provide an alternative prevention strategy for oral cancer development with CXB use.

Cortactin and phosphorylated cortactin tyr421 and tyr466 expression in supraglottic laryngeal carcinomas and lymph node metastases

Background:

The most important adverse prognostic factor for laryngeal squamous cell carcinoma (LSCC) is the presence of cervical lymph node metastases. The supraglottic area of the larynx is richly supplied with lymphatics, and 25%-75% of supraglottic carcinomas metastasize in neck lymph nodes. Cortactin is a multidomain protein related to actin cytoskeleton regulation, podosome and lamellipodia formation, integrin signaling, axon guidance and extracellular matrix degradation. Cortactin is involved in metastasis formation because of its role in cell mobility. The present study focused mainly on the role of cortactin and phosphorylated cortactin (residues tyr421 and tyr466) expression and subcellular localization in primary supraglottic LSCCs and their cervical lymph node metastases.

Methods:

The immunohistochemical expression of cortactin, p-Y466-cortactin and p-Y421-cortactin was assessed in 38 primary supraglottic LSCCs and 10 lymph node metastases. The statistical approach included bootstrapping analysis.

Results:

Despite a significantly higher expression of cortactin in carcinoma cells than in adjacent normal laryngeal mucosa, no associations emerged between prognosis and the expression of cortactin or its isoforms in supraglottic LSCC. Statistical analysis found cortactin expression higher in less-differentiated LSCCs (p = 0.03). A significant direct correlation was found between cortactin and p-Y466-cortactin levels (p = 0.031), and between p-Y466-cortactin and p-Y421-cortactin levels (p = 0.001).

Conclusions:

Cortactin expression in carcinoma cells and its known involvement in the EGFR pathway suggest a role for this protein as a target for LSCC therapy. Further prospective studies are needed to investigate the potential of cortactin, p-Y466-cortactin and p-Y421-cortactin expression as markers of response to treatment (particularly EGFR-directed agents) in LSCC.

Genetic and epigenetic characterization of the tumors in a patient with a tongue primary tumor, a recurrence and a pharyngoesophageal second primary tumor

Background

The choice of therapeutic modality for oral carcinoma in recurrent or second primary tumors remains controversial, as the treatment modalities available might be reduced by the treatment of the first tumor, and the overall survival is lower when compared with patients with a single or first tumor. Identifying biomarkers that predict the risk of relapse and the response to treatment is an emerging clinical issue.

Case presentation

A Caucasian 49-years-old man was treated with chemotherapy followed by chemoradiotherapy for a primary left side tongue tumor, achieving a complete response. After 49-months of follow-up, a local recurrence was diagnosed. After 3 months, a second primary tumor at the pharyngoesophageal region was detected. Genomic and epigenetic characterization of these three tumors was performed using array Comparative Genomic Hybridization, Multiplex Ligation-dependent Probe Amplification (MLPA) and Methylation Specific MLPA.

Results

The three tumors of this patient shared several imbalances in all chromosomes excluding chromosomes 9, 20 and 22, where genes related to important functional mechanisms of tumorigenesis are mapped. The shared genomic imbalances, such as losses at 1p, 2p, 3p, 4q, 5q, 6q, 7q, 8p, 10p, 11q, 12p, 12q, 13q, 15q, 16p, 16q, 17p, 17q, 18q, 19p, 19q, 21q and Xp and gains at 3q, 7q, 14q and 15q showed a common clonal origin for the diagnosed relapses.

We identified some chromosomal imbalances and genes mapped in the chromosomes 2, 3, 4, 6, 7, 11, 14, 17, 18 and 22 as putative linked to chemoradioresistance and chemoradiosensitivity. We also observed that gains in short arm of chromosomes 6, 7, 8 and 18 were acquired after treatment of the primary tumor. We identified losses of VHL gene and promoter methylation of WT1 and GATA5 genes, as predictors of relapses.

Conclusions

A common clonal origin for the diagnosed relapses was observed and we identified some putative candidate biomarkers of prognosis, relapse risk and treatment response that could guide the development of management strategies for these patients.

Cortactin and phosphorylated cortactin tyr466 expression in temporal bone carcinoma

PURPOSE

Cortactin is a multidomain protein engaged in several cellular mechanisms involving actin assembly and cytoskeletal arrangement. Cortactin overexpression in several malignancies has been associated with increased cell migration, invasion, and metastatic potential. Cortactin needs to be activated by tyrosine or serine/threonine phosphorylation. The role of cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) was investigated in temporal bone squamous cell carcinoma (TBSCC).

MATERIALS AND METHODS

Immunohistochemical expression of cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) was assessed in 27 consecutively-operated TBSCCs.

RESULTS

Several clinicopathological variables correlated with recurrence (pT stage, dura mater involvement), and disease-free survival (DFS) (cT stage, pT stage, pN status, dura mater involvement). Twenty-three of 24 immunohistochemically evaluable TBSCCs were cortactin-positive. Median cortactin expression was 75.0%. Cortactin reaction in the cytoplasm was more intense in carcinoma cells than in normal adjacent tissue. Recurrence and DFS rates did not correlate with cortactin and phosphorylated cortactin (residue tyr⁴⁶⁶) expression in TBSCC specimens.

CONCLUSIONS

Cortactin upregulation in TBSCC supports the conviction that inhibiting cortactin functions could have selective effects on this malignancy. Multi-institutional studies should further investigate the role of cortactin and phosphorylated cortactin in TBSCC, and their potential clinical application in integrated treatment modalities.

Inhibitory cortactin nanobodies delineate the role of NTA- and SH3-domain-specific functions during invadopodium formation and cancer cell invasion

Cancer cells exploit different strategies to escape from the primary tumor, gain access to the circulation, disseminate throughout the body, and form metastases, the leading cause of death by cancer. Invadopodia, proteolytically active plasma membrane extensions, are essential in this escape mechanism. Cortactin is involved in every phase of invadopodia formation, and its overexpression is associated with increased invadopodia formation, extracellular matrix degradation, and cancer cell invasion. To analyze endogenous cortactin domain function in these processes, we characterized the effects of nanobodies that are specific for the N-terminal acidic domain of cortactin and expected to target small epitopes within this domain. These nanobodies inhibit cortactin-mediated actin-related protein (Arp)2/3 activation, and, after their intracellular expression in cancer cells, decrease invadopodia formation, extracellular matrix degradation, and cancer cell invasion. In addition, one of the nanobodies affects Arp2/3 interaction and invadopodium stability, and a nanobody targeting the Src homology 3 domain of cortactin enabled comparison of 2 functional regions in invadopodium formation or stability. Given their common and distinct effects, we validate cortactin nanobodies as an instrument to selectively block and study distinct domains within a protein with unprecedented precision, aiding rational future generation of protein domain-selective therapeutic compounds.-Bertier, L., Boucherie, C., Zwaenepoel, O., Vanloo, B., Van Troys, M., Van Audenhove, I., Gettemans, J. Inhibitory cortactin nanobodies delineate the role of NTA- and SH3-domain-specific functions during invadopodium formation and cancer cell invasion.

Clinical Implications of FADD Gene Amplification and Protein Overexpression in Taiwanese Oral Cavity Squamous Cell Carcinomas

Amplification of 11q13.3 is a frequent event in human cancers, including head and neck squamous cell carcinoma. This chromosome region contains several genes that are potentially cancer drivers, including FADD (Fas associated via death domain), an apoptotic effector that was previously identified as a novel oncogene in laryngeal/pharyngeal cancer. This study was designed to explore the role of FADD in oral squamous cell carcinomas (OSCCs) samples from Taiwanese patients, by assessing copy number variations (CNVs) and protein expression and the clinical implications of these factors in 339 male OSCCs. The intensity of FADD protein expression, as determined by immunohistochemistry, was strongly correlated with gene copy number amplification, as analyzed using a TaqMan CNV assay. Both FADD gene copy number amplification and high protein expression were significantly associated with lymph node metastasis (P < 0.001). Patients with both FADD copy number amplification and high protein expression had the shortest disease-free survival (DFS; P = 0.074 and P = 0.002) and overall survival (OS; P = 0.011 and P = 0.027). After adjusting for primary tumor status, tumor differentiation, lymph node metastasis and age at diagnosis, DFS was still significantly lower in patients with either copy number amplification or high protein expression (hazard ratio [H.R.] = 1.483; 95% confidence interval [C.I.], 1.044–2.106). In conclusion, our data reveal that FADD gene copy number and protein expression can be considered potential prognostic markers and are closely associated with lymph node metastasis in patients with OSCC in Taiwan.

Novel role of cortactin in G protein-coupled receptor agonist-induced nuclear export and degradation of p21Cip1

Monocyte chemotactic protein 1 (MCP1) stimulates phosphorylation of cortactin on Y421 and Y446 residues in a time-dependent manner and phosphorylation at Y446 but not Y421 residue is required for MCP1-induced CDK-interacting protein 1 (p21Cip1) nuclear export and degradation in facilitating human aortic smooth muscle cell (HASMC) proliferation. In addition, MCP1-induced cortactin tyrosine phosphorylation, p21Cip1 degradation and HASMC proliferation are dependent on Fyn activation. Upstream to Fyn, MCP1 stimulated C-C chemokine receptor type 2 (CCR2) and Gi/o and inhibition of either one of these molecules using their specific antagonists or inhibitors attenuated MCP1-induced cortactin tyrosine phosphorylation, p21Cip1 degradation and HASMC proliferation. Cortactin phosphorylation at Y446 residue is also required for another G protein-coupled receptor (GPCR) agonist, thrombin-induced p21Cip1 nuclear export and its degradation in promoting HASMC proliferation. Quite interestingly, the receptor tyrosine kinase (RTK) agonist, platelet-derived growth factor-BB (PDGF-BB)-induced p21Cip1 degradation and HASMC proliferation do not require cortactin tyrosine phosphorylation. Together, these findings demonstrate that tyrosine phosphorylation of cortactin at Y446 residue is selective for only GPCR but not RTK agonist-induced nuclear export and proteolytic degradation of p21Cip1 in HASMC proliferation.

Tyrosine 397 phosphorylation is critical for FAK-promoted Rac1 activation and invasive properties in oral squamous cell carcinoma cells

Oral squamous cell carcinoma (OSCC) is a common cancer worldwide. Despite advances in diagnosis and therapy, treatment options for patients with metastatic OSCC are few, due in part to the limited understanding of the molecular events involved in the invasion and metastasis of OSCC. In this study, we investigated the expression of focal adhesion kinase (FAK) and its tyrosine 397 phosphorylation (pY397) in the tissue specimens of OSCC. The roles of pY397 in regulating the activities of Rac1 and cortactin and the invasive properties of OSCC cells were further determined. Results from immunohistochemical analyses in 9 benign, 19 premalignant, and 19 malignant oral tissues showed that the immunoreactivity of FAK was observed in 5 benign (56%), 19 premalignant (100%), and 18 malignant tissues (95%), whereas the immunoreactivity of pY397 was only found in 1 of 9 (11%) benign lesions but was observed in 9 premalignant (47%) and 12 malignant (63%) lesions. Compared with the low-invading SCC4 cells, the high-invading OECM-1 cells exhibited higher levels of FAK expression and pY397, correlating with higher levels of GTP-bound Rac1 and cortactin phosphorylation. Manipulation of FAK expression or Y397 phosphorylation in SCC4, FaDu, OECM-1, or HSC-3 cells regulated their Rac1 activities and invasive properties. Furthermore, treatment of NSC23766, a Rac1-specific inhibitor, in OECM-1 and HSC-3 cells led to reduced invasive properties. Nevertheless, knockdown of FAK expression or suppression of pY397 had no effect on the cortactin activity in OECM-1 cells. The data collectively suggest that pY397 plays critical roles in the FAK-promoted Rac1 activation and invasive properties in OSCC cells. Thus, the inhibition of FAK phosphorylation at Y397 or Rac1 activity can serve as a therapeutic strategy for treating patients with metastatic OSCC.

Modification of platelet proteins by 4-hydroxynonenal: Potential Mechanisms for inhibition of aggregation and metabolism

Platelet aggregation is an essential response to tissue injury and is associated with activation of pro-oxidant enzymes, such as cyclooxygenase, and is also a highly energetic process. The two central energetic pathways in the cell, glycolysis and mitochondrial oxidative phosphorylation, are susceptible to damage by reactive lipid species. Interestingly, how platelet metabolism is affected by the oxidative stress associated with aggregation is largely unexplored. To address this issue, we examined the response of human platelets to 4-hydroxynonenal (4-HNE), a reactive lipid species which is generated during thrombus formation and during oxidative stress. Elevated plasma 4-HNE has been associated with renal failure, septic shock and cardiopulmonary bypass surgery. In this study, we found that 4-HNE decreased thrombin stimulated platelet aggregation by approximately 60%. The metabolomics analysis demonstrated that underlying our previous observation of a stimulation of platelet energetics by thrombin glycolysis and TCA (Tricarboxylic acid) metabolites were increased. Next, we assessed the effect of both 4-HNE and alkyne HNE (A-HNE) on bioenergetics and targeted metabolomics, and found a stimulatory effect on glycolysis, associated with inhibition of bioenergetic parameters. In the presence of HNE and thrombin glycolysis was further stimulated but the levels of the TCA metabolites were markedly suppressed. Identification of proteins modified by A-HNE followed by click chemistry and mass spectrometry revealed essential targets in platelet activation including proteins involved in metabolism, adhesion, cytoskeletal reorganization, aggregation, vesicular transport, protein folding, antioxidant proteins, and small GTPases. In summary, the biological effects of 4-HNE can be more effectively explained in platelets by the integrated effects of the modification of an electrophile responsive proteome rather than the isolated effects of candidate proteins.

Lysophosphatidic acid activates the RhoA and NF-κB through Akt/IκBα signaling and promotes prostate cancer invasion and progression by enhancing functional invadopodia formation

We have demonstrated previously that increased RhoA and nuclear factor (NF)-κB activities are associated with increased PC-3 prostate cancer cell invasion and that lysophosphatidic acid (LPA) significantly increases cancer invasion through RhoA and NF-κB activation. In this study, we identified the intermediate signaling molecules and specialized cell structures which are activated by LPA, resulting in enhanced cellular invasion. LPA-induced Akt and IκBα signaling pathways were necessary for RhoA and NF-κB activation, and these LPA effects were abolished by RhoA inhibition. Mice injected with PC-3 cells expressing dominant-negative RhoA N19 developed significantly less tumor growth compared with those injected with control (pcDNA 3.1). In addition, LPA treatment increased functional invadopodia formation. Activation of RhoA and NF-κB through the Akt and IκBα signaling pathway was required for LPA-stimulated gelatin degradation activity. LPA administration increased tumor growth and osteolytic lesions in a mouse xenograft model. These results indicate that LPA promotes PC-3 cell invasion by increasing functional invadopodia formation via upregulating RhoA and NF-κB signaling which contributes to prostate cancer progression. Therefore, the LPA and RhoA-NF-κB signaling axis may represent key molecular targets to inhibit prostate cancer invasion and progression.

Src tyrosyl phosphorylates cortactin in response to prolactin

The hormone/cytokine prolactin (PRL) is implicated in breast cancer cell invasion and metastasis. PRL-induced pathways are mediated by two non-receptor tyrosine kinases, JAK2 and Src. We previously demonstrated that prolactin stimulates invasion of breast cancer cells TMX2-28 through JAK2 and its target serine/threonine kinase PAK1. We hypothesize herein that the actin-binding protein cortactin, a protein involved in invadopodia formation and cell invasion, is activated by PRL. We demonstrate that TMX2-28 cells are more invasive than T47D breast cancer cells in response to PRL. We determine that cortactin is tyrosyl phosphorylated in response to PRL in a time and dose-dependent manner in TMX2-28 cells, but not in T47D cells. Furthermore, we show that PRL mediates cortactin tyrosyl phosphorylation via Src, but not JAK2. Finally, we demonstrate that maximal PRL-mediated TMX2-28 cell invasion requires both Src and JAK2 kinase activity, while T47D cell invasion is JAK2- but not Src-dependent. Thus PRL may induce cell invasion via two pathways: through a JAK2/PAK1 mediated pathway that we have previously demonstrated, and Src-dependent activation and tyrosyl phosphorylation of cortactin.

Association between genetic polymorphisms in cortactin and susceptibility to gastric cancer

PURPOSE

Overexpression of cortactin (CTTN) in human tumors has been proposed to result in increased cell migration and metastatic potential. Here, we determined the frequencies of CTTN g.-9101C>T, g.-8748C>T, and g.72C>T polymorphisms in apparently healthy subjects and gastric cancer patients, respectively, and the influence of the CTTN polymorphisms on gastric cancer susceptibility.

METHODS

Blood samples were collected from 267 patients and 533 controls. CTTN g.-8748C>T and g.-9101C>T polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism; the g.72C>T polymorphism was determined using the TaqMan method.

RESULTS

Genotype frequencies of the CTTN g.-9101C>T polymorphism were 97.5% (TT), 2.5% (TC), and 0% (CC) in the patient group, and 98.6% (TT), 1.4% (TC), and 0% (CC) in the control group. Genotype frequencies of the CTTN g.-8748C>T polymorphism were 93.3% (TT), 6.8% (TC), and 0% (CC) in the patient group, and 94.2% (TT), 5.8% (TC), and 0% (CC) in the control group. Genotype frequencies of the CTTN g.72C>T polymorphism were 82.4% (CC), 17.2% (CT), and 0.4% (TT) in the patient group, and 78.0% (CC), 20.1% (CT), and 1.9% (TT) in the control group. Genotype and allele frequencies of the CTTN g.-9101C>T polymorphism differed significantly between the advanced gastric cancer and control groups. Patients with advanced gastric cancer, possessing the TC genotype, had a significantly poorer prognosis than the group with the TT genotype.

CONCLUSION

The CTTN g.-9101C>T polymorphism might influence advanced gastric cancer susceptibility. However, the role of the CTTN g.-9101C>T, g.-8748C>T, and g.72C>T polymorphisms requires careful interpretation and confirmation through larger studies.

Cortactin promotes colon cancer progression by regulating ERK pathway

Cortactin is upregulated in various cancers including breast cancer, head and neck squamous cell carcinoma and gastric cancer. However, the role of cortactin in the pathogenesis of colon cancer remains unclear. mRNA expression of cortactin in colon cancer samples and cell lines was detected by quantitative real-time PCR (qRT-PCR), while protein expression of cortactin in colon cancer tissues and adjacent non-cancer tissues was assessed by immunohistochemistry. The role of cortactin in regulation of the proliferation of colon cancer derived cells were investigated both in vitro and in vivo. In the total of 60 paired colon cancer specimens, compared with the adjacent non-cancer tissues, the expression of cortactin mRNA was upregulated in 45 (75.0%). Immunohistochemical analysis showed significantly increased cortactin expression in colon cancer (42/60, 70.0%) compared to control tissues (18/60, 30.0%). Overexpression of cortactin promoted HCT116 cellular colony formation and tumor growth. Conversely, cortactin knockdown inhibited these effects in SW480 cells. Mechanistic analyses indicated that cortactin was able to activate the EGFR-ERK signaling pathway. Additionally, cortactin expression was associated with tumor size, tumor stages and lymphatic invasion, increased cortactin expression predicts poor prognosis in patients with colon cancer. In summary, cortactin demonstrated the promotive effect in human colon cancer cell growth and tumorigenicity. These results indicated that cortactin may serve as an effective target for gene therapy.

Mechanisms of Invasion in Head and Neck Cancer

CONTEXT

The highly invasive properties demonstrated by head and neck squamous cell carcinoma (HNSCC) are often associated with locoregional recurrence and lymph node metastasis in patients and is a key factor leading to an expected 5-year survival rate of approximately 50% for patients with advanced disease. It is important to understand the features and mediators of HNSCC invasion so that new treatment approaches can be developed.

OBJECTIVES

To provide an overview of the characteristics, mediators, and mechanisms of HNSCC invasion.

DATA SOURCES

A literature review of peer-reviewed articles in PubMed on HNSCC invasion.

CONCLUSIONS

Histologic features of HNSCC tumors can help predict prognosis and influence clinical treatment decisions. Cell surface receptors, signaling pathways, proteases, invadopodia function, epithelial-mesenchymal transition, microRNAs, and tumor microenvironment are all involved in the regulation of the invasive behavior of HNSCC cells. Identifying effective HNSCC invasion inhibitors has the potential to improve outcomes for patients by reducing the rate of spread and increasing responsiveness to chemoradiation.

Possible role of glial cells in the relationship between thyroid dysfunction and mental disorders

It is widely accepted that there is a close relationship between the endocrine system and the central nervous system (CNS). Among hormones closely related to the nervous system, thyroid hormones (THs) are critical for the development and function of the CNS; not only for neuronal cells but also for glial development and differentiation. Any impairment of TH supply to the developing CNS causes severe and irreversible changes in the overall architecture and function of the human brain, leading to various neurological dysfunctions. In the adult brain, impairment of THs, such as hypothyroidism and hyperthyroidism, can cause psychiatric disorders such as schizophrenia, bipolar disorder, anxiety and depression. Although impact of hypothyroidism on synaptic transmission and plasticity is known, its effect on glial cells and related cellular mechanisms remain enigmatic. This mini-review article summarizes how THs are transported into the brain, metabolized in astrocytes and affect microglia and oligodendrocytes, demonstrating an example of glioendocrine system. Neuroglial effects may help to understand physiological and/or pathophysiological functions of THs in the CNS and how hypo- and hyper-thyroidism may cause mental disorders.

Tumor and stromal-based contributions to head and neck squamous cell carcinoma invasion

Head and neck squamous cell carcinoma (HNSCC) is typically diagnosed at advanced stages with evident loco-regional and/or distal metastases. The prevalence of metastatic lesions directly correlates with poor patient outcome, resulting in high patient mortality rates following metastatic development. The progression to metastatic disease requires changes not only in the carcinoma cells, but also in the surrounding stromal cells and tumor microenvironment. Within the microenvironment, acellular contributions from the surrounding extracellular matrix, along with contributions from various infiltrating immune cells, tumor associated fibroblasts, and endothelial cells facilitate the spread of tumor cells from the primary site to the rest of the body. Thus far, most attempts to limit metastatic spread through therapeutic intervention have failed to show patient benefit in clinic trails. The goal of this review is highlight the complexity of invasion-promoting interactions in the HNSCC tumor microenvironment, focusing on contributions from tumor and stromal cells in order to assist future therapeutic development and patient treatment.

Effects of 3,3',5-triiodothyronine on microglial functions

L-tri-iodothyronine (3, 3', 5-triiodothyronine; T3) is an active form of the thyroid hormone (TH) essential for the development and function of the CNS. Though nongenomic effect of TH, its plasma membrane-bound receptor, and its signaling has been identified, precise function in each cell type of the CNS remained to be investigated. Clearance of cell debris and apoptotic cells by microglia phagocytosis is a critical step for the restoration of damaged neuron-glia networks. Here we report nongenomic effects of T3 on microglial functions. Exposure to T3 increased migration, membrane ruffling and phagocytosis of primary cultured mouse microglia. Injection of T3 together with stab wound attracted more microglia to the lesion site in vivo. Blocking TH transporters and receptors (TRs) or TRα-knock-out (KO) suppressed T3-induced microglial migration and morphological change. The T3-induced microglial migration or membrane ruffling was attenuated by inhibiting Gi /o -protein as well as NO synthase, and subsequent signaling such as phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK). Inhibitors for Na(+) /K(+) -ATPase, reverse mode of Na(+) /Ca(2+) exchanger (NCX), and small-conductance Ca(2+) -dependent K(+) (SK) channel also attenuated microglial migration or phagocytosis. Interestingly, T3-induced microglial migration, but not phagocytosis, was dependent on GABAA and GABAB receptors, though GABA itself did not affect migratory aptitude. Our results demonstrate that T3 modulates multiple functional responses of microglia via multiple complex mechanisms, which may contribute to physiological and/or pathophysiological functions of the CNS.