Interleukin-8 promotes cell migration through integrin αvβ6 upregulation in colorectal cancer

CXCL3/TGF-β-mediated crosstalk between CAFs and tumor cells augments RCC progression and sunitinib resistance

Cancer-associated fibroblasts (CAFs) play a significant role in tumor development and treatment failure, yet the precise mechanisms underlying their contribution to renal cell carcinoma (RCC) remains underexplored. This study explored the interaction between CAFs and tumor cells, and related mechanisms. CAFs isolated from tumor tissues promoted the tumor progression and drugs resistance both in vivo and in vitro. Mechanistically, chemokine (C-X-C motif) ligand (CXCL) 3 secreted from CAFs mediated its effects. CXCL3 activated its receptor CXCR2 to active the downstream ERK1/2 signaling pathway, subsequently promoting epithelial-mesenchymal transition and cell stemness. Blocking the crosstalk between CAFs and tumor cells by CXCR2 inhibitor SB225002 attenuated the functions of CAFs. Furthermore, Renca cells facilitated the transformation of normal interstitial fibroblasts (NFs) into CAFs and the expression of CXCL3 through TGF-β-Smad2/3 signaling pathway. In turn, transformed NFs promoted the tumor progression and drug resistance of RCC. These findings may constitute potential therapeutic strategies for RCC treatment.

miR-200c-3p regulates α4 integrin-mediated T cell adhesion and migration

A microRNA miR-200c-3p is a regulator of epithelial-mesenchymal transition to control adhesion and migration of epithelial and mesenchymal cells. However, little is known about whether miR-200c-3p affects lymphocyte adhesion and migration mediated by integrins. Using TK-1 (a T lymphoblast cell) as a model of T cell, here we show that repressed expression of miR-200c-3p upregulated α4 integrin-mediated adhesion to and migration across mucosal addressin cell adhesion molecule-1 (MAdCAM-1). Conversely, overexpression of miR-200c-3p downregulated α4 integrin-mediated adhesion and migration. Unlike in epithelial cells, miR-200c-3p did not target talin, a conformation activator of integrin, but, targeted E26-transformation-specific sequence 1 (ETS1), a transcriptional activator of α4 integrin, in T cells. Treatment of the miR-200c-3p-low-expressing TK-1 cells that possessed elevated α4 integrin with ETS1 small interfering RNA (siRNA) resulted in the reversion of the α4 integrin expression, supporting that ETS1 is a target of miR-200c-3p. A potential proinflammatory immune-modulator retinoic acid (RA) treatment of TK-1 cells elicited a significant reduction of miR-200c-3p and simultaneously a marked increase in ETS1 and α4 integrin expression. An anti-inflammatory cytokine TGF-β1 treatment elevated miR-200c-3p, thereby downregulating ETS1 and α4 integrin expression. These results suggest that miR-200c-3p is an important regulator of α4 integrin expression and functions and may be controlled by RA and TGF-β1 in an opposite way. Overexpression of miR-200c-3p could be a novel therapeutic option for treatment of gut inflammation through suppressing α4 integrin-mediated T cell migration.

Role of Interleukins in Inflammation-Mediated Tumor Immune Microenvironment Modulation in Colorectal Cancer Pathogenesis

INTRODUCTION

Tumor cells invade and spread through a procedure termed as epithelial-to-mesenchymal cell transition (EMT). EMT is triggered by any alterations in the genes that encode the extracellular matrix (ECM) proteins, the enzymes that break down the ECM, and the activation of the genes that causes the epithelial cell to change into a mesenchymal type. The transcription factors NF-κB, Smads, STAT3, Snail, Zeb, and Twist are activated by inflammatory cytokines, for instance, Tumor Necrosis Factor, Tumor Growth Factors, Interleukin-1, Interleukin-8, and Interleukin-6, which promotes EMT.

MATERIALS

The current piece of work has been reviewed from the literature works published in last 10 years on the role interleukins in inflammation-mediated tumor immune microenvironment modulation in colorectal cancer pathogenesis utilizing the databases like Google Scholar, PubMed, Science Direct.

RESULTS

Recent studies have demonstrated that pathological situations, such as epithelial malignancies, exhibit EMT characteristics, such as the downregulation of epithelial markers and the overexpression of mesenchymal markers. Several growing evidence have also proved its existence in the human colon during the carcinogenesis of colorectal cancer. Most often, persistent inflammation is thought to be one factor contributing to the initiation of human cancers, such as colorectal cancer (CRC). Therefore, according to epidemiologic and clinical research, people with ulcerative colitis and Crohn's disease have a greater probability of developing CRC.

CONCLUSION

A substantial amount of data points to the involvement of the NF-κB system, SMAD/STAT3 signaling cascade, microRNAs, and the Ras-mitogen-activated protein kinase/Snail/Slug in the epithelial-to-mesenchymal transition-mediated development of colorectal malignancies. As a result, EMT is reported to play an active task in the pathogenesis of colorectal cancer, and therapeutic interventions targeting the inflammation-mediated EMT might serve as a novel strategy for treating CRC. The illustration depicts the relationship between interleukins and their receptors as a driver of CRC development and the potential therapeutic targets.

Interleukins (Cytokines) as Biomarkers in Colorectal Cancer: Progression, Detection, and Monitoring

Cancer is the primary cause of death in economically developed countries and the second leading cause in developing countries. Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Risk factors for CRC include obesity, a diet low in fruits and vegetables, physical inactivity, and smoking. CRC has a poor prognosis, and there is a critical need for new diagnostic and prognostic biomarkers to reduce related deaths. Recently, studies have focused more on molecular testing to guide targeted treatments for CRC patients. The most crucial feature of activated immune cells is the production and release of growth factors and cytokines that modulate the inflammatory conditions in tumor tissues. The cytokine network is valuable for the prognosis and pathogenesis of colorectal cancer as they can aid in the cost-effective and non-invasive detection of cancer. A large number of interleukins (IL) released by the immune system at various stages of CRC can act as "biomarkers". They play diverse functions in colorectal cancer, and include IL-4, IL-6, IL-8, IL-11, IL-17A, IL-22, IL-23, IL-33, TNF, TGF-β, and vascular endothelial growth factor (VEGF), which are pro-tumorigenic genes. However, there are an inadequate number of studies in this area considering its correlation with cytokine profiles that are clinically useful in diagnosing cancer. A better understanding of cytokine levels to establish diagnostic pathways entails an understanding of cytokine interactions and the regulation of their various biochemical signaling pathways in healthy individuals. This review provides a comprehensive summary of some interleukins as immunological biomarkers of CRC.

Development of a low-seroprevalence, αvβ6 integrin-selective virotherapy based on human adenovirus type 10

Oncolytic virotherapies (OV) hold immense clinical potential. OV based on human adenoviruses (HAdV) derived from HAdV with naturally low rates of pre-existing immunity will be beneficial for future clinical translation. We generated a low-seroprevalence HAdV-D10 serotype vector incorporating an αvβ6 integrin-selective peptide, A20, to target αvβ6-positive tumor cell types. HAdV-D10 has limited natural tropism. Structural and biological studies of HAdV-D10 knob protein highlighted low-affinity engagement with native adenoviral receptors CAR and sialic acid. HAdV-D10 fails to engage blood coagulation factor X, potentially eliminating "off-target" hepatic sequestration in vivo. We engineered an A20 peptide that selectively binds αvβ6 integrin into the DG loop of HAdV-D10 fiber knob. Assays in αvβ6+ cancer cell lines demonstrated significantly increased transduction mediated by αvβ6-targeted variants compared with controls, confirmed microscopically. HAdV-D10.A20 resisted neutralization by neutralizing HAdV-C5 sera. Systemic delivery of HAdV-D10.A20 resulted in significantly increased GFP expression in BT20 tumors. Replication-competent HAdV-D10.A20 demonstrated αvβ6 integrin-selective cell killing in vitro and in vivo. HAdV-D10 possesses characteristics of a promising virotherapy, combining low seroprevalence, weak receptor interactions, and reduced off-target uptake. Incorporation of an αvβ6 integrin-selective peptide resulted in HAdV-D10.A20, with significant potential for clinical translation.

Roles of the CXCL8-CXCR1/2 Axis in the Tumor Microenvironment and Immunotherapy

In humans, Interleukin-8 (IL-8 or CXCL8) is a granulocytic chemokine with multiple roles within the tumor microenvironment (TME), such as recruiting immunosuppressive cells to the tumor, increasing tumor angiogenesis, and promoting epithelial-to-mesenchymal transition (EMT). All of these effects of CXCL8 on individual cell types can result in cascading alterations to the TME. The changes in the TME components such as the cancer-associated fibroblasts (CAFs), the immune cells, the extracellular matrix, the blood vessels, or the lymphatic vessels further influence tumor progression and therapeutic resistance. Emerging roles of the microbiome in tumorigenesis or tumor progression revealed the intricate interactions between inflammatory response, dysbiosis, metabolites, CXCL8, immune cells, and the TME. Studies have shown that CXCL8 directly contributes to TME remodeling, cancer plasticity, and the development of resistance to both chemotherapy and immunotherapy. Further, clinical data demonstrate that CXCL8 could be an easily measurable prognostic biomarker in patients receiving immune checkpoint inhibitors. The blockade of the CXCL8-CXCR1/2 axis alone or in combination with other immunotherapy will be a promising strategy to improve antitumor efficacy. Herein, we review recent advances focusing on identifying the mechanisms between TME components and the CXCL8-CXCR1/2 axis for novel immunotherapy strategies.

Roles of Integrins in Gastrointestinal Cancer Metastasis

Integrins are a large family of heterodimeric transmembrane receptors which mediate cell adhesion and transmit signals to the cell interior. The mechanistic roles of integrins have long been an enigma in cancer, given its complexity in regulating different cellular behaviors. Recently, however, increasing research is providing new insights into its function and the underlying mechanisms, which collectively include the influences of altered integrin expression on the aberrant signaling pathways and cancer progression. Many studies have also demonstrated the potentiality of integrins as therapeutic targets in cancer treatment. In this review, we have summarized these recent reports and put a particular emphasis on the dysregulated expression of integrins and how they regulate related signaling pathways to facilitate the metastatic progression of gastrointestinal cancer, including gastric cancer (GC) and colorectal cancer (CRC), which will address the crucial roles of integrins in gastrointestinal cancer.

A microwell-based impedance sensor on an insertable microneedle for real-time in vivo cytokine detection

Impedance-based protein detection sensors for point-of-care diagnostics require quantitative specificity, as well as rapid or real-time operation. Furthermore, microfabrication of these sensors can lead to the formation of factors suitable for in vivo operation. Herein, we present microfabricated needle-shaped microwell impedance sensors for rapid-sample-to-answer, label-free detection of cytokines, and other biomarkers. The microneedle form factor allows sensors to be utilized in transcutaneous or transvascular sensing applications. In vitro, experimental characterization confirmed sensor specificity and sensitivity to multiple proteins of interest. Mechanical characterization demonstrated sufficient microneedle robustness for transcutaneous insertion, as well as preserved sensor function postinsertion. We further utilized these sensors to carry out real-time in vivo quantification of human interleukin 8 (hIL8) concentration levels in the blood of transgenic mice that endogenously express hIL8. To assess sensor functionality, hIL8 concentration levels in serum samples from the same mice were quantified by ELISA. Excellent agreement between real-time in vivo sensor readings in blood and subsequent ELISA serum assays was observed over multiple transgenic mice expressing hIL8 concentrations from 62 pg/mL to 539 ng/mL.

Nonphosphorylatable PEA15 mutant inhibits epithelial-mesenchymal transition in triple-negative breast cancer partly through the regulation of IL-8 expression

Background

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype that lacks targeted therapies. Patients with TNBC have a very poor prognosis because the disease often metastasizes. New treatment approaches addressing drivers of metastasis and tumor growth are crucial to improving patient outcomes. Developing targeted gene therapy is thus a high priority for TNBC patients. PEA15 (phosphoprotein enriched in astrocytes, 15 kDa) is known to bind to ERK, preventing ERK from being translocated to the nucleus and hence blocking its activity. The biological function of PEA15 is tightly regulated by its phosphorylation at Ser104 and Ser116. However, the function and impact of phosphorylation status of PEA15 in the regulation of TNBC metastasis and in epithelial-to-mesenchymal transition (EMT) are not well understood.

Methods

We established stable cell lines overexpressing nonphosphorylatable (PEA15-AA) and phospho-mimetic (PEA15-DD) mutants. To dissect specific cellular mechanisms regulated by PEA15 phosphorylation status, we performed RT-PCR immune and metastasis arrays. In vivo mouse models were used to determine the effects of PEA15 phosphorylation on tumor growth and metastasis.

Results

We found that the nonphosphorylatable mutant PEA15-AA prevented formation of mammospheres and expression of EMT markers in vitro and decreased tumor growth and lung metastasis in in vivo experiments when compared to control, PEA15-WT and phosphomimetic PEA15-DD. However, phosphomimetic mutant PEA15-DD promoted migration, mesenchymal marker expression, tumorigenesis, and lung metastasis in the mouse model. PEA15-AA-mediated inhibition of breast cancer cell migratory capacity and tumorigenesis was the partial result of decreased expression of interleukin-8 (IL-8). Further, we identified that expression of IL-8 was possibly mediated through one of the ERK downstream molecules, Ets-1.

Conclusions

Our results show that PEA15 phosphorylation status serves as an important regulator for PEA15’s dual role as an oncogene or tumor suppressor and support the potential of PEA15-AA as a therapeutic strategy for treatment of TNBC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06316-2.

Research trends in pharmacological modulation of tumor-associated macrophages

As one of the most abundant immune cell populations in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play important roles in multiple solid malignancies, including breast cancer, prostate cancer, liver cancer, lung cancer, ovarian cancer, gastric cancer, pancreatic cancer, and colorectal cancer. TAMs could contribute to carcinogenesis, neoangiogenesis, immune-suppressive TME remodeling, cancer chemoresistance, recurrence, and metastasis. Therefore, reprogramming of the immune-suppressive TAMs by pharmacological approaches has attracted considerable research attention in recent years. In this review, the promising pharmaceutical targets, as well as the existing modulatory strategies of TAMs were summarized. The chemokine-chemokine receptor signaling, tyrosine kinase receptor signaling, metabolic signaling, and exosomal signaling have been highlighted in determining the biological functions of TAMs. Besides, both preclinical research and clinical trials have suggested the chemokine-chemokine receptor blockers, tyrosine kinase inhibitors, bisphosphonates, as well as the exosomal or nanoparticle-based targeting delivery systems as the promising pharmacological approaches for TAMs deletion or reprogramming. Lastly, the combined therapies of TAMs-targeting strategies with traditional treatments or immunotherapies as well as the exosome-like nanovesicles for cancer therapy are prospected.

Hitting the Target but Missing the Point: Recent Progress towards Adenovirus-Based Precision Virotherapies

More people are surviving longer with cancer. Whilst this can be partially attributed to advances in early detection of cancers, there is little doubt that the improvement in survival statistics is also due to the expansion in the spectrum of treatments available for efficacious treatment. Transformative amongst those are immunotherapies, which have proven effective agents for treating immunogenic forms of cancer, although immunologically "cold" tumour types remain refractive. Oncolytic viruses, such as those based on adenovirus, have great potential as anti-cancer agents and have seen a resurgence of interest in recent years. Amongst their many advantages is their ability to induce immunogenic cell death (ICD) of infected tumour cells, thus providing the alluring potential to synergise with immunotherapies by turning immunologically "cold" tumours "hot". Additionally, enhanced immune mediated cell killing can be promoted through the local overexpression of immunological transgenes, encoded from within the engineered viral genome. To achieve this full potential requires the development of refined, tumour selective "precision virotherapies" that are extensively engineered to prevent off-target up take via native routes of infection and targeted to infect and replicate uniquely within malignantly transformed cells. Here, we review the latest advances towards this holy grail within the adenoviral field.

Expression of Integrin β6 and HAX-1 Correlates with Aggressive Features and Poor Prognosis in Esophageal Squamous Cell Carcinoma

Purpose

The development of esophageal squamous cell carcinoma (ESCC) is a complicated process in which cell adhesion and motility, mediated by integrins, are involved through connecting the cytoskeleton to extracellular matrix. Different mechanisms via which integrin β6 participates in cancer invasion and metastasis have been described by numerous studies; however, the expression and clinical significance of integrin β6 in ESCC remain unknown.

Methods

To investigate the differential expression of integrin β6 in ESCC, qPCR and immunohistochemistry assays were performed in 10 paired human samples. A total of 137 ESCC samples were further enrolled to evaluate the expression levels of integrin β6 and its endocytic trafficking regulator HS1-associated protein X-1 (HAX-1), followed by the evaluation of their correlation with clinicopathological parameters. The overall survival was analyzed using the Kaplan–Meier method, with significant variables further evaluated by multivariate Cox regression analyses.

Results

The expression of integrin β6 was markedly increased in ESCC compared with matched adjacent normal tissues. Among the ESCC samples, positive expression of integrin β6 was observed in 41.6% tumors, which was associated with histological differentiation, lymph node metastasis and TNM stage. High expression of HAX-1 was detected in 47.4% tumors, and there was a positive relationship between the expression levels of integrin β6 and HAX-1. Furthermore, the expression of integrin β6 and HAX-1 were independent unfavorable indicators for prognosis. Patients with positive integrin β6 and high HAX-1 expression demonstrated worst outcomes.

Conclusion

The present findings suggested the predictive value of integrin β6 and HAX-1 as independent indicators of poor prognosis for patients with ESCC, both of which may contribute to the tumor proliferation and metastasis, leading to ESCC progression. Therefore, combined targeting of integrin β6 and HAX-1 may provide a potential novel approach for the treatment of ESCC.

Interleukin-6 Promotes Epithelial-Mesenchymal Transition and Cell Invasion through Integrin β6 Upregulation in Colorectal Cancer

The metastatic potential of colorectal cancer (CRC) is intensively promoted by the tumor microenvironment (TME) in a paracrine manner. As a pleiotropic inflammatory cytokine, Interleukin-6 (IL-6) is produced and involved in CRC, the same scenario where integrin αvβ6 also becomes upregulated. However, the relationship between IL-6 and integrin αvβ6 as well as their involvement in the crosstalk between CRC and TME remains largely unclear. In the present study, we demonstrated a positive correlation between the expression of IL-6 and integrin β6 in CRC samples. The mutually promotive interaction between CRC and TME was further determined by an indirect coculture system. CRC cells could augment the secretion of IL-6 from fibroblasts, which in return induced invasion and integrin β6 expression of CRC cells. Through the classic IL-6 receptor/STAT-3 signaling pathway, IL-6 mediated the upregulation of integrin β6, which was involved in the invasion and epithelial-mesenchymal transition of CRC cells induced by IL-6. Taken together, our results reveal a paracrine crosstalk between IL-6 signals originating from the TME and increased the integrin β6 level of CRC. IL-6 induces CRC invasion via upregulation of integrin β6 through the IL-6 receptor/STAT-3 signaling pathway. Combined inhibition of IL-6 along with integrin β6-targeted strategy may indicate new directions for antitumor strategies for CRC.

The Role of Interleukins in Colorectal Cancer

Despite great progress has been made in treatment strategies, colorectal cancer (CRC) remains the predominant life-threatening malignancy with the feature of high morbidity and mortality. It has been widely acknowledged that the dysfunction of immune system, including aberrantly expressed cytokines, is strongly correlated with the pathogenesis and progression of colorectal cancer. As one of the most well-known cytokines that were discovered centuries ago, interleukins are now uncovering new insights into colorectal cancer therapy. Herein, we divide currently known interleukins into 6 families, including IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family and IL-17 family. In addition, we comprehensively reviewed the oncogenic or antitumour function of each interleukin involved in CRC pathogenesis and progression by elucidating the underlying mechanisms. Furthermore, by providing interleukins-associated clinical trials, we have further driven the profound prospect of interleukins in the treatment of colorectal cancer.

Integrin αvβ6 predicts poor prognosis and promotes resistance to cisplatin in hilar cholangiocarcinoma

OBJECTIVE

Integrin αvβ6 is associated with an extremely aggressive cancer phenotype. However, little is known about the clinicopathological significance and prognostic value of integrin αvβ6 in human hilar cholangiocarcinoma.

METHODS

In the present study, bioinformatics analysis demonstrated a significant increase of integrin β6 gene expression in cholangiocarcinoma tissues compared to non-tumorous tissues, which was further validated in clinical samples through RT-qPCR and western blotting analyses. Integrin αvβ6 was observed to be expressed in 48.6% of tumors, and its expression was related to a poor tumor differentiation (p = 0.002), lymph node metastasis (p<0.001) and advanced TNM stage (p=0.001). Furthermore, patients who were αvβ6-positive showed a significantly shorter overall survival period than those who were αvβ6-negative (p=0.004). Multivariate analysis confirmed that integrin αvβ6 was an independent prognostic factor (p=0.002). In addition, loss- and gain-of-function assays showed integrin αvβ6 not only played an important role in colony formation, but also protected cholangiocarcinoma cells from cisplatin-induced growth inhibition and apoptosis. ERK/MAPK signaling pathway was involved in integrin αvβ6-mediated resistance of cholangiocarcinoma cells to cisplatin.

CONCLUSIONS

Taken together, the present findings revealed that integrin αvβ6 could serve as a potential prognostic predictor and contribute to cisplatin resistance, which might prove to be a promising target candidate for the clinical intervention of human hilar cholangiocarcinoma.

Interleukin-8 promotes integrin β3 upregulation and cell invasion through PI3K/Akt pathway in hepatocellular carcinoma

Background

Interleukin-8 (IL-8) plays a vital role in the invasion and metastasis of hepatocellular carcinoma (HCC), and is closely associated with poor prognosis of HCC patients. Integrin αvβ3, a member of the integrin family, has been reported to be overexpressed in cancer tissues and mediate the invasion and metastasis of HCC cells. However, the relationship between IL-8 and integrin αvβ3 in HCC and the underlying mechanism of IL-8 and integrin αvβ3 in the invasion of HCC remains unclear.

Methods

The expression of IL-8, integrin αv and integrin β3 in HCC cells and tissues was detected by quantitative real-time PCR, Western blot and immunohistochemistry. Transwell assay and Western blot was used to detect the invasiveness, the expression of integrin β3 and the activation of PI3K/Akt pathway of HCC cells pretreated with IL-8 knockdown or exogenous IL-8.

Results

IL-8, integrin αv and integrin β3 were overexpressed in highly metastatic HCC cell lines compared with low metastatic cell lines. There was a positive correlation between integrin β3 and IL-8 expression in HCC tissues. IL-8 siRNA transfection reduced HCC cell invasion and the levels of integrin β3, p-PI3K and p-Akt. IL-8 induced HCC cell invasion and integrin β3 expression was significantly inhibited by transfection with CXCR1 siRNA or CXCR2 siRNA. When we stimulated HCC cells with exogenous IL-8, cell invasion and the levels of integrin β3, p-PI3K, and p-Akt increased, which could be effectively reversed by adding PI3K inhibitor LY294002.

Conclusions

Our results suggest that IL-8 promotes integrin β3 upregulation and the invasion of HCC cells through activation of the PI3K/Akt pathway. The IL-8/CXCR1/CXCR2/PI3K/Akt/integrin β3 axis may serve as a potential treatment target for patients with HCC.

SO2 derivatives and As co-exposure promote liver cancer metastasis through integrin αvβ3 activation

Arsenic (As) and sulfur dioxide (SO₂) are two environmental pollutants that have been shown to promote the development of human cancer. In recent years, due to increased pollution, humans are often exposed to SO₂, in addition to As. Despite the development and implementation of standards for environment and air quality, cases of disease caused by As or SO₂ continue to rise alarmingly. It is currently unknown whether simultaneous exposure to As and SO₂ results in increased cancer promoting activity. In this study, concentrations of As and SO₂ below the limits established by the world health organization (WHO) in force environmental standards (concentrations of As should be lower than 1×10^-2 mg/L and SO₂ should be lower than 50 μg/m³), were employed to investigate possible, long-term, synergistic effects of As and SO₂, by using cell-based assays. We found that co-exposure to these pollutants significantly promotes HepG2 cancer cell migration, while As or SO₂ alone have no remarkable effects. Integrins αvβ3 play a key role in this process, as cilengitide, an integrin αvβ3 inhibitor, substantially prevented As and SO₂-induced cell migration. MMPs, IL-8, and TGF-β were also involved in the induced cell migration. In summary, combined exposure to As and SO₂ promotes integrin-dependent cell migration and may be of relevance for the activation of mechanisms underlying liver cancer progression.

CAR T-Cells Targeting the Integrin αvβ6 and Co-Expressing the Chemokine Receptor CXCR2 Demonstrate Enhanced Homing and Efficacy against Several Solid Malignancies

Despite the unprecedented clinical success of chimeric antigen receptors (CAR) T-cells against haematological malignancy, solid tumors impose a far greater challenge to success. Largely, this stems from an inadequate capacity of CAR T-cells that can traffic and maintain function within a hostile microenvironment. To enhance tumor-directed T-cell trafficking, we have engineered CAR T-cells to acquire heightened responsiveness to interleukin (IL)-8. Circulating IL-8 levels correlate with disease burden and prognosis in multiple solid tumors in which it exerts diverse pathological functions including angiogenesis, support of cancer stem cell survival, and recruitment of immunosuppressive myeloid cells. To harness tumor-derived IL-8 for therapeutic benefit, we have co-expressed either of its cognate receptors (CXCR1 or CXCR2) in CAR T-cells that target the tumor-associated αvβ6 integrin. We demonstrate here that CXCR2-expressing CAR T-cells migrate more efficiently towards IL-8 and towards tumor conditioned media that contains this cytokine. As a result, these CAR T-cells elicit superior anti-tumor activity against established αvβ6-expressing ovarian or pancreatic tumor xenografts, with a more favorable toxicity profile. These data support the further engineering of CAR T-cells to acquire responsiveness to cancer-derived chemokines in order to improve their therapeutic activity against solid tumors.

Expression of Interleukin-6 and Integrin ανβ6 in Colon Cancer: Association with Clinical Outcomes and Prognostic Implications

As important factors in the tumor microenvironment, interleukin-6 (IL-6) and integrin ανβ6 play significant roles in accumulating mutations that drive the progression and metastatic capacities of cancer. The aim of this study was to investigate the expression of IL-6 and integrin ανβ6, their clinical significance, as well as their correlation in the colon cancer tissues of 145 cases using immunohistochemistry. Our results showed that IL-6 and integrin ανβ6 are indicators of cancer progression and poor prognosis in patients with colon cancer. Moreover, their relationship may provide clues for further studies on how the tumor microenvironment mediates the development of colon cancer, as well as strategies for the identification of novel therapeutic targets in the prevention and treatment of colon cancer.

Cell-free DNA derived from cancer cells facilitates tumor malignancy through Toll-like receptor 9 signaling-triggered interleukin-8 secretion in colorectal cancer

Circulating cell-free DNA (cfDNA) has become a potential diagnostic and prognostic biomarker for colorectal cancer (CRC). In non-cancerous diseases, it has been confirmed that cfDNA can be recognized by Toll-like receptor 9 (TLR9), leading to a significant biological change. Nevertheless, the biological significance of cfDNA and its relationship with TLR9 in tumor malignancy is still unclear. Therefore, the purpose of this study is to explore the biological role of cfDNA in colorectal cancer (CRC). The expression of TLR9 was measured in different CRC cell lines and cancerous samples by RT-PCR or immunohistochemistry, which showed that high expression of TLR9 was significantly correlated with the tumor metastasis, advanced TNM stage and poor prognosis of patients. Then, cfDNA was obtained from fluorouracil (5FU)-induced apoptotic cancer cells in vitro and transfection techniques were used to transfect siRNA and cDNA plasmid for TLR9. Cancer cells were stimulated using isolated cfDNA fragments, and results showed that cfDNA could promote colorectal cancer cell proliferation via TLR9. Meanwhile, we demonstrated that the cfDNA binding to TLR9 could facilitate cell migration and invasion. Finally, we demonstrated that cfDNA initiated downstream TLR9-MyD88 signaling and induced robust release of chemokine interleukin 8 (IL-8), which helped to elucidate the mechanisms underlying these phenomena. Our data suggest that cancer cell-derived cfDNA contributes to cancer progression through activation of TLR9-MyD88 signaling and IL-8 secretion in CRC. These findings provide a novel perspective for understanding of tumor progression and provoke a potential therapeutic target for CRC treatment.

Role of polymorphisms in genes that encode cytokines and Helicobacter pylori virulence factors in gastric carcinogenesis

The Helicobacter pylori (H. pylori) infection is a determinant factor in gastric cancer (GC) development. However, the infection outcomes are variable and depend on both host and bacterial characteristics. Some host cytokines such as interleukin (IL)-1β, IL-1Ra, IL-8, IL-10 and tumor necrosis factor-α play important roles in the host immune system response to the pathogen, in the development of gastric mucosal lesions and in cell malignant transformation. Therefore, these host factors are crucial in neoplastic processes. Certain polymorphisms in genes that encode these cytokines have been associated with an increased risk of GC. On the other hand, various virulence factors found in distinct H. pylori bacterial strains, including cytotoxin-associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and blood group antigen binding adhesin, have been associated with the pathogenesis of different gastric diseases. The virulent factors mentioned above allow the successful infection by the bacterium and play crucial roles in gastric mucosa lesions, including malignant transformation. Moreover, the role of host polymorphisms and bacterial virulence factors in gastric carcinogenesis seems to vary among different countries and populations. The identification of host and bacterium factors that are associated with an increased risk of GC development may be useful in determining the prognosis of infection in patients, what could help in clinical decision-making and in providing of an optimized clinical approach.

Adipocytes Promote Early Steps of Breast Cancer Cell Dissemination via Interleukin-8

Fat is a major tissue component in human breast cancer (BC). Whether breast adipocytes (BAd) affect early stages of BC metastasis is yet unknown. BC progression is dependent on angiogenesis and inflammation, and interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) are key regulators of these events. Here, we show that BAd increased the dissemination of estrogen receptor positive BC cells (BCC) in vivo in the zebrafish model of metastasis, while dissemination of the more aggressive and metastatic BCC such as estrogen receptor negative was unaffected. While anti-VEGF and anti-IL-8 exhibited equal inhibition of angiogenesis at the primary tumor site, anti-IL-8 reduced BCC dissemination whereas anti-VEGF had minor effects on this early metastatic event. Mechanistically, overexpression of cell-adhesion molecules in BCC and neutrophils via IL-8 increased the dissemination of BCC. Importantly, the extracellular in vivo levels of IL-8 were 40-fold higher than those of VEGF in human BC. Our results suggest that IL-8 is a clinical relevant and promising therapeutic target for human BC.

An impedimetric immunosensor for highly sensitive detection of IL-8 in human serum and saliva samples: A new surface modification method by 6-phosphonohexanoic acid for biosensing applications

In this study, we fabricated a sensitive and label-free impedimetric immunosensor based on 6-phosphonohexanoic acid (PHA) modified ITO electrode for detection of interleukin-8 (IL-8) in human serum and saliva. PHA was first employed to cancer biomarker sensing platform. Anti-IL-8 antibody was used as a biorecognition element and the detection principle of this immunosensor was based on monitoring specific interaction between anti-IL-8 antibody and IL-8 antigen. The morphological characterization of each electrode modification step was analyzed by scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) while electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and single frequency impedance (SFI) techniques. Moreover, the antibody immobilization on the electrode surface was proved Fourier-transform infrared spectroscopy (FTIR) and Raman Spectroscopy. This proposed impedimetric immunosensor exhibited good performances with a wide linear in the range from 0.02 pg/mL to 3 pg/mL as well as a relative low detection limit of 6 fg/mL. The impedimetric immunosensor had a good specificity, stability and reproducibility. This study proved that PHA was a suitable interface material to fabricate an electrochemical biosensor.

Arabinoxylan hydrolyzates as immunomodulators in Caco-2 and HT-29 colon cancer cell lines

The use of plant derived polysaccharides as health promoters has gained immense interest in the past few years. Arabinoxylan (AX) is the predominant non-starch polysaccharide in cereals and grasses including wheat. The current research aimed to investigate the structure-function relationship of arabinoxylan hydrolyzates (AXH), obtained by the enzymatic hydrolysis of AX using xylanase and arabinofuranosidase as immunomodulators in two colon cancer cell lines: Caco-2 and HT-29. Fine structural details had a strong correlation with the immunological properties of the wheat AXH. As a general trend, as the presence of arabinose substitution increased in the AXH, the production of proinflammatory cytokines, IL-8 and TNF-α, decreased in both cell lines. Thus, AXH with a higher degree of arabinose substitution might be better adept in lowering inflammation in colon cancer cells.

Integrin αvβ6 Promotes Lung Cancer Proliferation and Metastasis through Upregulation of IL-8-Mediated MAPK/ERK Signaling

Lung cancer is notorious for high morbidity and mortality around the world. Interleukin (IL)-8, a proinflammatory chemokine with tumorigenic and proangiogenic effects, promotes lung cancer cells growth and migration and contributes to cell aggressive phenotypes. Integrin αvβ6 is a receptor of transmembrane heterodimeric cell surface adhesion, and its overexpression correlates with poor survival from non–small cell lung cancer. However, the cross talk between αvβ6 and IL-8 in lung cancer has not been characterized so far. Herein, human lung cancer samples were analyzed, and it revealed that the immunohistochemical and mRNA expression of integrin αvβ6 was significantly correlated with the expression of IL-8. Furthermore, in vitro, integrin αvβ6 increased cell proliferation, migration, and invasion by impairing the expressions of MMP-2 and MMP-9 and inhibited cell apoptosis in human lung cancer cells A549 and H460. In addition, integrin αvβ6 upregulated IL-8 expression through activating MAPK/ERK signaling. The in vivo experiment showed that integrin αvβ6 promoted tumor growth in xenograft model mice by accelerating tumor volume and reducing apoptosis. Meanwhile, lung metastasis model experiment suggested that integrin αvβ6 stimulated tumor metastasis with the increase of lung/total weight and tumor nodules. Simultaneously, integrin αvβ6 upregulated IL-8 expression detected by both Western blots and immunohistochemistry, along with the activation of MAPK/ERK signaling. Overall, these data suggested that, in vitro and in vivo, integrin αvβ6 promoted lung cancer proliferation and metastasis, at least in part, through upregulation of IL-8–mediated MAPK/ERK signaling. Thus, the inhibition of integrin αvβ6 and IL-8 may be the key for the treatment of lung cancer.

Tumor specific delivery and therapy mediate by integrin β6-target immunoliposomes for β6-siRNA in colon carcinoma

Adjuvant chemotherapy does not achieve the desired therapeutic efficacy in colon cancer as a result of the deficient reaction. Gene therapy using small interfering RNAs (siRNAs) delivered by target delivering system represents a potent and specific strategy in tumor therapy. Integrinβ6 is exclusively expressed in malignant colonic epithelia, associated with the progression, metastasis, and chemotherapeutic resistance of colon cancer. Accordingly, designing an efficient and targeted delivery system for β6-siRNA could be a potential approach to improve therapeutic efficacy of colon cancer. Here, we designed the Integrinβ6 target immunoliposomes for highly efficient and selective delivery of β6-siRNA in colon cancer, which consequently resulted in greatly growth suppression, invasion and metastasis of colon cancer cells. Moreover, it was able to greatly inhibit the tumor growing in vivo.

GRO-α and IL-8 enhance ovarian cancer metastatic potential via the CXCR2-mediated TAK1/NFκB signaling cascade

Intraperitoneal metastasis is a common occurrence and is usually involved in the poor prognosis of ovarian cancer. Its specific metastatic pattern implies that certain indispensable microenvironmental factors secreted in the peritoneal cavity can direct metastatic ovarian cancer cells to permissive niches for secondary lesion formation. However, the underlying molecular mechanisms are ill defined. Herein, we report that GRO-α and IL-8 are predominately upregulated in culture media derived from either normal or cancerous omenta and are associated with increased ovarian cancer aggressiveness. Methods: OCM was established from culture medium of fresh human omental tissues. Primary and metastatic ovarian cancer cell lines were generated from human tumor tissues and verified by specific antibodies. The functional roles of GRO-α, IL-8, and their specific receptor CXCR2 were examined by neutralizing antibodies, shRNA gene knockdown, CRISPR/Cas9 gene knockout and pharmaceutical CXCR2 inhibitor SB225002. The oncogenic properties of ovarian cancer cells were examined by in vitro and in vivo mouse models. Results: Both GRO-α and IL-8 can activate TAK1/NFκB signaling via the CXCR2 receptor. Intriguingly, TAK1/NFκB signaling activity was higher in metastatic ovarian cancer cells; this higher activity makes them more susceptible to OCM-induced tumor aggressiveness. Treatment of ovarian cancer cells with GRO-α and IL-8 neutralizing antibodies or ablation of CXCR2 by shRNA gene knockdown, CRISPR/Cas9 gene knockout, or CXCR2 inhibitor SB225002 treatment significantly attenuated TAK1/NFκB signaling and decreased in vitro and in vivo oncogenic and metastatic potential, suggesting CXCR2 plays a key role in the GRO-α and IL-8-governed metastatic spreading of ovarian cancer cells in the intraperitoneal cavity. Conclusion: This study highlights the significance of GRO-α and IL-8 as the key chemokines in the peritoneal tumor microenvironment and suggests the utility of targeting their receptor CXCR2 as a potential target-based therapy for peritoneal metastases of ovarian cancer.

TNFα induces tolerant production of CXC chemokines in colorectal cancer HCT116 cells via A20 inhibition of ERK signaling

Ubiquitin editing enzyme A20 functions as a tumor suppressor in various cancer. However, the mechanism for A20 regulation of cancer progress is not fully understood. In this study, we found that in human colorectal cancer HCT116 cells, TNFα induced a tolerant production of CXC chemokines, including CXCL1, 2, and 8 in a dose and time dependent manner. TNFα pre-treatment of HCT116 cells down-regulated the chemokine production induced by TNFα re-treatment. TNFα induced the phosphorylation of MAPKs ERK, JNK, P38 and NF-κB P65, but only ERK inhibition decreased TNFα-induced chemokine production. Both RT-PCR and FACS results showed that TNFα treatment did not regulate the expression of TNF receptors. However, TNFα up-regulated the expression of A20 at both mRNA and protein levels significantly. TNFα pre-treatment inhibited the signal transduction of MAPKs induced by TNFα re-stimulation, and A20 over-expression decreased the signal transduction of ERK and P38. Meanwhile, A20 inhibition by RNA interference reversed chemokine down-regulation induced by TNFα re-stimulation after TNFα pre-treatment. Taken together, these results suggested that in human colorectal cancer cells, A20 may function to inhibit cancer progression via down-regulation of TNFα-induced chemokine production by suppression of ERK signaling.

IL-17B activated mesenchymal stem cells enhance proliferation and migration of gastric cancer cells

Mesenchymal stem cells are important cells in tumor microenvironment. We have previously demonstrated that IL-17B/IL-17RB signal promoted progression of gastric cancer. In this study, we further explored the effect of IL-17B on mesenchymal stem cells in tumor microenvironment and its impact on the tumor progression. The results showed that IL-17B induced the expression of stemness-related genes Nanog, Sox2, and Oct4 in mesenchymal stem cells and enhanced its tumor-promoting effect. The supernatant from cultured mesenchymal stem cells after treating with exogenous rIL-17B promoted the proliferation and migration of MGC-803, therefor suggesting that rIL-17B might promote mesenchymal stem cells to produce soluble factors. In addition, rIL-17B also activated the NF-κΒ, STAT3, β-catenin pathway in mesenchymal stem cells. Our data revealed a new mechanism that IL-17B enhanced the progression of gastric cancer by activating mesenchymal stem cells.

Investigating in vitro and in vivo αvβ6 integrin receptor-targeting liposomal alendronate for combinatory γδ T cell immunotherapy

The αvβ6 integrin receptor has been shown to be overexpressed on many types of cancer cells, resulting in a more pro-invasive and aggressive phenotype, this makes it an attractive target for selective drug delivery. In tumours that over-express the αvβ6 receptor, cellular uptake of liposomes can be enhanced using ligand-targeted liposomes. It has previously been shown in both in vitro and in vivo studies that liposomal alendronate (L-ALD) can sensitise cancer cells to destruction by Vγ9Vδ2 T cells. It is hypothesised that by using the αvβ6-specific peptide A20FMDV2 as a targeting moiety for L-ALD, the therapeutic efficacy of this therapy can be increased in αvβ6 positive tumours. Targeted liposomes (t-L) were formulated and the targeting efficacy of targeted liposomes (t-L) was assessed by cell uptake and cytotoxicity studies in the αvβ6 positive cells line A375Pβ6. Bio-distribution of both L and t-L were carried out in αvβ6 positive (A375Pβ6 and PANC0403) and αvβ6 negative (A375Ppuro and PANC-1) subcutaneous tumour mouse models. Immuno-compromised mice bearing A375Pβ6 experimental metastatic lung tumours were treated with L-ALD or t-L-ALD as monotherapies or in combination with ex vivo-expanded Vγ9Vδ2 T cells. In vitro, αvβ6-dependant uptake of t-L was observed, with t-L-ALD being more effective than L-ALD at sensitising A375Pβ6 to γδ T cells. Interestingly, t-L-ALD led to slightly higher but not significant reduction in tumour growth compared to L-ALD, when used as monotherapy in vivo. Moreover, both L-ALD and t-L-ALD led to significant reductions in tumour growth when used in combination with γδ T cells in vivo but t-L-ALD offered no added advantage compared to L-ALD.

Mxi1-0 regulates the growth of human umbilical vein endothelial cells through extracellular signal-regulated kinase 1/2 (ERK1/2) and interleukin-8 (IL-8)-dependent pathways

Mxi1 plays an important role in the regulation of cell proliferation. Mxi1-0, a Mxi1 isoform, has a different N-terminal amino acid sequence, intracellular location and expression profile from Mxi1. However, the precise role of Mxi1-0 in cell proliferation and the molecular mechanism underlying its function remain poorly understood. Here, we showed that Mxi1-0 suppression decreased the proliferation of human umbilical vein endothelial cells (HUVECs) along with cell accumulation in the G2/M phase. Mxi1-0 suppression also significantly decreased the expression and secretion of interleukin (IL-8). Neutralizing IL-8 in conditioned medium (CM) from Mxi1-0-overexpressed HUVECs significantly eliminated CM-induced proliferation of HUVECs. In addition, Mxi1-0 suppression significantly decreased the activity of MAP kinase ERK1/2. Treatment of HUVECs with U0126, an ERK1/2 signaling inhibitor, attenuated autocrine production of IL-8 induced by Mxi1-0 overexpression. On the other hand, Mxi1-0 overexpression-induced IL-8 increased the level of phosphorylated ERK1/2 in HUVECs, and such increasing was diminished in cells incubated with CM, which neutralized with anti-IL-8 antibody. Taken together, our results suggest that Mxi1-0 regulates the growth of HUVECs via the IL-8 and ERK1/2 pathways, which apparently reciprocally activate each other.

CXC chemokine receptor 1 predicts postoperative prognosis and chemotherapeutic benefits for TNM II and III resectable gastric cancer patients

Backround: Abnormal expression of CXC chemokine receptor 1 (CXCR1) has shown the ability to promote tumor angiogensis, invasion and metastasis in several cancers. The purpose of our curret study is to discover the clinical prognostic significance of CXCR1 in resectable gastric cancer.

METHODS

330 gastric cancer patients who underwent R0 gastrectomy with standard D2 lymphadenectomy at Zhongshan Hospital, Fudan University between 2007 and 2008 were enrolled. CXCR1 expression was evaluated with use of immunohistochemical staining. The relation between CXCR1 expression and clinicopathological features and postoperative prognosis was respectively inspected.

RESULTS

In both discovery and validation data sets, CXCR1 high expression indicated poorer overall survival (OS) in TNM II and III patients. Furthermore, multivariate analysis identified CXCR1 expression and TNM stage as two independent prognostic factors for OS. Incorporating CXCR1 expression into current TNM staging system could generate a novel clinical predictive model for gastric cancer, showing better prognostic accuracy with respect to patients' OS. More importantly, TNM II patients with higher CXCR1 expression were shown to significantly benefit from postoperative 5-fluorouracil (5-FU) based adjuvant chemotherapy (ACT).

CONCLUSION

CXCR1 in gastric cancer was identified as an independent adverse prognostic factor. Combining CXCR1 expression with current TNM staging system could lead to better risk stratification and more accurate prognosis for gastric cancer patients. High expression of CXCR1 identified a subgroup of TNM stage II gastric cancer patients who appeared to benefit from 5-FU based ACT.

The CXCL8-CXCR1/2 pathways in cancer

Persistent infection or chronic inflammation contributes significantly to tumourigenesis and tumour progression. C-X-C motif ligand 8 (CXCL8) is a chemokine that acts as an important multifunctional cytokine to modulate tumour proliferation, invasion and migration in an autocrine or paracrine manner. Studies have suggested that CXCL8 and its cognate receptors, C-X-C chemokine receptor 1 (CXCR1) and CX-C chemokine receptor 2 (CXCR2), mediate the initiation and development of various cancers including breast cancer, prostate cancer, lung cancer, colorectal carcinoma and melanoma. CXCL8 also integrates with multiple intracellular signalling pathways to produce coordinated effects. Neovascularisation, which provides a basis for fostering tumour growth and metastasis, is now recognised as a critical function of CXCL8 in the tumour microenvironment. In this review, we summarize the biological functions and ficlinical significance of the CXCL8 signalling axis in cancer. We also propose that CXCL8 may be a potential therapeutic target for cancer treatment

Colorectal cancer-promoting activity of the senescent peritoneal mesothelium

Gastrointestinal cancers metastasize into the peritoneal cavity in a process controlled by peritoneal mesothelial cells (HPMCs). In this paper we examined if senescent HPMCs can intensify the progression of colorectal (SW480) and pancreatic (PSN-1) cancers in vitro and in vivo. Experiments showed that senescent HPMCs stimulate proliferation, migration and invasion of SW480 cells, and migration of PSN-1 cells. When SW480 cells were injected i.p. with senescent HPMCs, the dynamics of tumor formation and vascularization were increased. When xenografts were generated using PSN-1 cells, senescent HPMCs failed to favor their growth. SW480 cells subjected to senescent HPMCs displayed up-regulated expression of transcripts for various pro-cancerogenic agents as well as increased secretion of their products. Moreover, they underwent an epithelial-mesenchymal transition in the Smad 2/3-Snail1-related pathway. The search for mediators of senescent HPMC activity showed that increased SW480 cell proliferation was stimulated by IL-6, migration by CXCL8 and CCL2, invasion by IL-6, MMP-3 and uPA, and epithelial-mesenchymal transition by TGF-β1. Secretion of these agents by senescent HPMCs was increased in an NF-κB- and p38 MAPK-dependent mechanism. Collectively, our findings indicate that in the peritoneum senescent HPMCs may create a metastatic niche in which critical aspects of cancer progression become intensified.

Integrin β6 serves as an immunohistochemical marker for lymph node metastasis and promotes cell invasiveness in cholangiocarcinoma

Cholangiocarcinoma is a devastating malignancy that is notoriously difficult to diagnose and is associated with a high mortality. Despite extensive efforts to improve the diagnosis and treatment of this neoplasm, limited progress has been made. Integrin β6 is a subtype of integrin that is expressed exclusively on the surfaces of epithelial cells and is associated with a variety of tumors. In the present study, we investigated the expression and roles of integrin β6 in cholangiocarcinoma. β6 upregulation in cholangiocarcinoma was correlated with lymph node metastasis and distant metastasis. Moreover, integrin β6 was identified as a biomarker for the diagnosis of cholangiocarcinoma and an indicator of lymph node metastasis. Integrin β6 significantly promoted the proliferation, migration and invasion of cholangiocarcinoma cells. Furthermore, integrin β6 increased Rac1-GTPase, resulting in the upregulation of metalloproteinase-9 (MMP9) and F-actin polymerization. Taken together, our results indicate that integrin β6 promotes tumor invasiveness in a Rac1-dependent manner and is a potential biomarker for tumor metastasis. Integrin β6 may help to improve the diagnostic accuracy, and targeting β6 may be a novel strategy for the treatment of cholangiocarcinoma.

Computational Identification of Key Regulators in Two Different Colorectal Cancer Cell Lines

Transcription factors (TFs) are gene regulatory proteins that are essential for an effective regulation of the transcriptional machinery. Today, it is known that their expression plays an important role in several types of cancer. Computational identification of key players in specific cancer cell lines is still an open challenge in cancer research. In this study, we present a systematic approach which combines colorectal cancer (CRC) cell lines, namely 1638N-T1 and CMT-93, and well-established computational methods in order to compare these cell lines on the level of transcriptional regulation as well as on a pathway level, i.e., the cancer cell-intrinsic pathway repertoire. For this purpose, we firstly applied the Trinity platform to detect signature genes, and then applied analyses of the geneXplain platform to these for detection of upstream transcriptional regulators and their regulatory networks. We created a CRC-specific position weight matrix (PWM) library based on the TRANSFAC database (release 2014.1) to minimize the rate of false predictions in the promoter analyses. Using our proposed workflow, we specifically focused on revealing the similarities and differences in transcriptional regulation between the two CRC cell lines, and report a number of well-known, cancer-associated TFs with significantly enriched binding sites in the promoter regions of the signature genes. We show that, although the signature genes of both cell lines show no overlap, they may still be regulated by common TFs in CRC. Based on our findings, we suggest that canonical Wnt signaling is activated in 1638N-T1, but inhibited in CMT-93 through cross-talks of Wnt signaling with the VDR signaling pathway and/or LXR-related pathways. Furthermore, our findings provide indication of several master regulators being present such as MLK3 and Mapk1 (ERK2) which might be important in cell proliferation, migration, and invasion of 1638N-T1 and CMT-93, respectively. Taken together, we provide new insights into the invasive potential of these cell lines, which can be used for development of effective cancer therapy.

Common Effects on Cancer Cells Exerted by a Random Positioning Machine and a 2D Clinostat

In this study we focused on gravity-sensitive proteins of two human thyroid cancer cell lines (ML-1; RO82-W-1), which were exposed to a 2D clinostat (CLINO), a random positioning machine (RPM) and to normal 1g-conditions. After a three (3d)- or seven-day-culture (7d) on the two devices, we found both cell types growing three-dimensionally within multicellular spheroids (MCS) and also cells remaining adherent (AD) to the culture flask, while 1g-control cultures only formed adherent monolayers, unless the bottom of the culture dish was covered by agarose. In this case, the cytokines IL-6 and IL-8 facilitated the formation of MCS in both cell lines using the liquid-overlay technique at 1g. ML-1 cells grown on the RPM or the CLINO released amounts of IL-6 and MCP-1 into the supernatant, which were significantly elevated as compared to 1g-controls. Release of IL-4, IL-7, IL-8, IL-17, eotaxin-1 and VEGF increased time-dependently, but was not significantly influenced by the gravity conditions. After 3d on the RPM or the CLINO, an accumulation of F-actin around the cellular membrane was detectable in AD cells of both cell lines. IL-6 and IL-8 stimulation of ML-1 cells for 3d and 7d influenced the protein contents of ß₁-integrin, talin-1, Ki-67, and beta-actin dose-dependently in adherent cells. The ß₁-integrin content was significantly decreased in AD and MCS samples compared with 1g, while talin-1 was higher expressed in MCS than AD populations. The proliferation marker Ki-67 was elevated in AD samples compared with 1g and MCS samples. The ß-actin content of R082-W-1 cells remained unchanged. ML-1 cells exhibited no change in ß-actin in RPM cultures, but a reduction in CLINO samples. Thus, we concluded that simulated microgravity influences the release of cytokines in follicular thyroid cancer cells, and the production of ß₁-integrin and talin-1 and predicts an identical effect under real microgravity conditions.

Gastric cancer-derived mesenchymal stem cells prompt gastric cancer progression through secretion of interleukin-8

Background

Bone marrow mesenchymal stem cells (BM-MSCs) have been identified to be closely associated with tumor growth and progression. However, the roles of tumor-resident MSCs in cancer have not been thoroughly clarified. This study was to investigate the regulating effect of gastric cancer-derived MSCs (GC-MSCs) on gastric cancer and elucidate the underlying mechanism.

Methods

GC-MSCs were isolated from primary human gastric cancer tissues and characterized. The effect of GC-MSCs on gastric cancer cell proliferation was analyzed by MTT assay and colony formation assay. Transwell migration assay was performed to evaluate the influence of GC-MSCs in gastric cancer cell migration. The regulating effects of interactions between gastric cancer cells and GC-MSCs on their pro-angiogenic abilities were analyzed in a co-culture system, with the expression, and secretion of pro-angiogenic factors detected by RT-PCR and Luminex assay. Tube formation assay was used to further validate the angiogenic capability of gastric cancer cells or GC-MSCs. Cytokine profiles in the supernatant of GC-MSCs were screened by Luminex assay and neutralizing antibody was used to identify the key effective cytokines. The activations of Akt and Erk1/2 in gastric caner cells were detected by Western blot.

Results

GC-MSC treatment enhanced the proliferation and migration of BGC-823 and MKN-28 cells, which was more potently than MSCs from adjacent non-cancerous tissues (GCN-MSCs) or bone marrow (BM-MSCs). Higher expression levels of pro-angiogenic factors were detected in GC-MSCs than GCN-MSCs or BM-MSCs. After 10 % GC-MSC-CM treatment, BGC-823, and MKN-28 cells expressed increased levels of pro-angiogenic factors and facilitated tube formation more potently than cancer cells alone. Furthermore, GC-MSCs produced an extremely higher level of interleukin-8 (IL-8) than GCN-MSCs or BM-MSCs. Blockade of IL-8 by neutralizing antibody significantly attenuated the tumor-promoting effect of GC-MSCs. In addition, 10 % CM of IL-8-secreted GC-MSCs induced the activations of Akt or Erk1/2 pathway in BGC-823 and MKN-28 cells.

Conclusion

Tumor-resident GC-MSCs promote gastric cancer growth and progression more efficiently than GCN-MSCs or BM-MSCs through a considerable secretion of IL-8, which could be a possible target for gastric cancer therapy.

Integrin β6 can be translationally regulated by eukaryotic initiation factor 4E: Contributing to colonic tumor malignancy

It is well known that both eukaryotic initiation factor 4E (eIF4E) and integrin αvβ6 can contribute to malignant behavior of colon cancer. We have found that integrin αvβ6 and eIF4E were co-expressed and positively correlated in colon cancer tissues. Recently, deregulation of the protein synthesis apparatus has begun to gain attention as a major participant in cancer development and progression. However, the regulation of integrin β6 expression at translational level has never been investigated before. In present study, gene-silencing technique for eIF4E by small interfering RNA (siRNA) was used in all the subsequent experiments, in order to investigate whether eIF4E could translationally regulate expression of integrin β6 in colon cancer SW480 and HT-29 cell lines. Additionally, the subsequent effects of eIF4E knockdown on cellular malignant behavior were observed. siRNA in SW480 and HT-29 transfectants. Subsequently, protein expression of β6 was markedly suppressed, while mRNA expression of β6 showed no significant variation before and after eIF4E RNA interfering. Therefore, it could be seen that eIF4E could upregulate the expression of β6, without effect on β6 mRNA expression. More importantly, after treated with eIF4E siRNA, cellular migratory capacity on fibronectin of HT-29 and β6-transfected SW480 as well as their survival to 5-FU was decreased distinctly. Expression of integrin β6 could be translationally regulated by eIF4E, which subsequently contributed to tumor malignancy through enhancing cellular migration, survival, anti-apoptosis, and chemoresistance of colon cancer in vitro. Thus, targeting eIF4E in integrin αvβ6 expressing tumors can be a potential therapeutic strategy for patients with colon cancer.

A novel multiplexed immunoassay identifies CEA, IL-8 and prolactin as prospective markers for Dukes' stages A-D colorectal cancers

Background

Current methods widely deployed for colorectal cancers (CRC) screening lack the necessary sensitivity and specificity required for population-based early disease detection. Cancer-specific protein biomarkers are thought to be produced either by the tumor itself or other tissues in response to the presence of cancers or associated conditions. Equally, known examples of cancer protein biomarkers (e.g., PSA, CA125, CA19-9, CEA, AFP) are frequently found in plasma at very low concentration (pg/mL-ng/mL). New sensitive and specific assays are therefore urgently required to detect the disease at an early stage when prognosis is good following surgical resection. This study was designed to meet the longstanding unmet clinical need for earlier CRC detection by measuring plasma candidate biomarkers of cancer onset and progression in a clinical stage-specific manner. EDTA plasma samples (1 μL) obtained from 75 patients with Dukes’ staged CRC or unaffected controls (age and sex matched with stringent inclusion/exclusion criteria) were assayed for expression of 92 human proteins employing the Proseek® Multiplex Oncology I proximity extension assay. An identical set of plasma samples were analyzed utilizing the Bio-Plex Pro™ human cytokine 27-plex immunoassay.

Results

Similar quantitative expression patterns for 13 plasma antigens common to both platforms endorsed the potential efficacy of Proseek as an immune-based multiplex assay for proteomic biomarker research. Proseek found that expression of Carcinoembryonic Antigen (CEA), IL-8 and prolactin are significantly correlated with CRC stage.

Conclusions

CEA, IL-8 and prolactin expression were found to identify between control (unaffected), non-malignant (Dukes’ A + B) and malignant (Dukes’ C + D) stages.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9081-x) contains supplementary material, which is available to authorized users.