RNAi targeting CXCR4 inhibits proliferation and invasion of esophageal carcinoma cells

Delivery of siRNA using hyaluronic acid‐guided nanoparticles for downregulation of CXCR4

In this study, effective transport of small interfering RNAs (siRNAs) via hyaluronic acid (HA) receptor was carried out with biodegradable HA and low-molecular weight polyethyleneimine (PEI)-based transport systems. Gold nanoparticles (AuNPs) capable of giving photothermal response, and their conjugates with PEI and HA, were also added to the structure. Thus, a combination of gene silencing, photothermal therapy and chemotherapy, has been accomplished. The synthesized transport systems ranged in size, between 25 and 690 nm. When the particles were applied at a concentration of 100 μg mL^-1 (except AuPEI NPs) in vitro, cell viability was above 50%. Applying radiation after the conjugate/siRNA complex (especially those containing AuNP) treatment, increased the cytotoxic effect (decrease in cell viability of 37%, 54%, 13%, and 15% for AuNP, AuPEI NP, AuPEI-HA, and AuPEI-HA-DOX, respectively) on the MDA-MB-231 cell line. CXCR4 gene silencing via the synthesized complexes, especially AuPEI-HA-DOX/siRNA was more efficient in MDA-MB-231 cells (25-fold decrease in gene expression) than in CAPAN-1 cells. All these results demonstrated that the synthesized PEI-HA and AuPEI-HA-DOX conjugates can be used as siRNA carriers that are particularly effective, especially in the treatment of breast cancer.

MicroRNA-210 aggravates hypoxia-induced injury in cardiomyocyte H9c2 cells by targeting CXCR4

BACKGROUND

Myocardial infarction (MI), a leading cause of mortality, is identified as the myocardial necrosis due to prolonged ischemia. Hypoxia, resulting from ischemia, induces cell apoptosis during MI. Since miR-210 is a hypoxia inducible factor, we aimed to explore the functional role of miR-210 in hypoxic H9c2 cells.

METHODS

Hypoxia-induced cell injury was evaluated according to cell viability, apoptosis and expression of apoptosis-associated proteins. miR-210 expression after hypoxia was tested. Then, miR-210 was overexpressed or silenced, and its effects on viability and apoptosis of H9c2 cells under normoxia and hypoxia were measured. Utilizing bioinformatics method, possible target genes of miR-210 were screened, and the interaction between miR-210 and target gene was investigated. Moreover, the effect of co-transfections with microRNAs and small interfering RNAs on hypoxia-induced cell injury as well as the possible involved signaling pathways was also determined.

RESULTS

Hypoxia induced cell injury and up-regulation of miR-210 in H9c2 cells. Hypoxia-induced cell injury was aggravated by miR-210 overexpression but was attenuated by miR-210 suppression. CXC chemokine receptor 4 (CXCR4) was a target gene of miR-210, and CXCR4 inhibition could reverse the effects of miR-210 inhibition on H9c2 cells. Furthermore, the key kinases involved in the SMAD and mTOR signaling pathways were down-regulated by hypoxia, and the down-regulations were reversed by miR-210 suppression through modulating CXCR4.

CONCLUSION

miR-210 was up-regulated in hypoxic H9c2 cells. Suppression of miR-210 attenuated hypoxia-induced cell injury in H9c2 cells by targeting CXCR4, along with activations of the SMAD and mTOR signaling pathways.

Modeling Idiopathic Pulmonary Fibrosis in Humanized Severe Combined Immunodeficient Mice

Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung disease of unknown etiopathogenesis with limited therapeutic options. IPF is characterized by an abundance of fibroblasts and loss of epithelial progenitors, which cumulates in unrelenting fibrotic lung remodeling and loss of normal oxygenation. IPF has been challenging to model in rodents; nonetheless, mouse models of lung fibrosis provide clues as to the natural progression of lung injury and remodeling, but many have not been useful in predicting efficacy of therapeutics in clinical IPF. We provide a detailed methodologic description of various iterations of humanized mouse models, initiated by the i.v. injection of cells from IPF lung biopsy or explants specimens into severe combined immunodeficiency (SCID)/beige or nonobese diabetic SCID γ mice. Unlike cells from normal lung samples, IPF cells promote persistent, nonresolving lung remodeling in SCID mice. Finally, we provide examples and discuss potential advantages and pitfalls of human-specific targeting approaches in a humanized SCID model of pulmonary fibrosis.

Anti-fibrotic Effects of CXCR4-Targeting i-body AD-114 in Preclinical Models of Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease that is prevalent in individuals >50 years of age, with a median survival of 3–5 years and limited therapeutic options. The disease is characterized by collagen deposition and remodeling of the lung parenchyma in a process that is thought to be driven by collagen-expressing immune and structural cells. The G-protein coupled C-X-C chemokine receptor 4, CXCR4, is a candidate therapeutic target for IPF owing to its role in the recruitment of CXCR4⁺ fibrocytes from the bone marrow to fibrotic lung tissue and its increased expression levels by structural cells in fibrotic lung tissue. We have engineered a novel fully human single domain antibody “i-body” called AD-114 that binds with high affinity to human CXCR4. We demonstrate here that AD-114 inhibits invasive wound healing and collagen 1 secretion by human IPF fibroblasts but not non-diseased control lung fibroblasts. Furthermore, in a murine bleomycin model of pulmonary fibrosis, AD-114 reduced the accumulation of fibrocytes (CXCR4⁺/Col1⁺/CD45⁺) in fibrotic murine lungs and ameliorated the degree of lung injury. Collectively, these studies demonstrate that AD-114 holds promise as a new biological therapeutic for the treatment of IPF.

Immunotherapy for esophageal cancer: Current studies and future perspectives

Esophageal cancer is one of the most common malignant tumors of the digestive system, and China has the highest morbidity and mortality rates of esophageal cancer in the world. Currently, main therapies for esophageal cancer include endoscopy, surgery, chemotherapy, and radiotherapy. These traditional treatments have appreciated clinical effects, but the prognosis of this malignancy is still poor. There is accumulating evidence that tumor immune microenvironment plays a key role in the development and progression of esophageal cancer. Recent clinical investigations and ongoing studies indicate that immunotherapy might have a great potential in the treatment of patients with esophageal cancer. Future studies will identify treatment strategies that can maximize therapeutic benefits by combining immunotherapies with existing and novel treatment modalities.

CXCR4 and CCR7: Two eligible targets in targeted cancer therapy

Cancer is one of the most common cause of death in the world with high negative emotional, economic, and social impacts. Conventional therapeutic methods, including chemotherapy and radiotherapy, have not proven satisfactory and relapse is common in most cases. Recent studies have focused on targeted therapy with more precise identification and targeted attacks to the cancer cells. For this purpose, chemokine receptors are proper targets and among them, CXCR4 and CCR7, with a crucial role in cancer metastasis, are being considered as desired candidates for investigation. In this review paper, the most important experimental results are highlighted on the potential targeted therapies based on CXCR4 and CCR7 chemokine receptors.

Esophageal cancer stem cells and implications for future therapeutics

Esophageal carcinoma (EC) is a lethal disease with high morbidity and mortality worldwide, and the incidence has been increasing in recent years. Although the diagnosis and treatment of EC have improved considerably, EC has rapidly progressed in the clinical setting and has a poor prognosis for its metastasis and recurrence. The general idea of cancer stem cells (CSCs) is primarily based on clinical and experimental observations, indicating the existence of a subpopulation of cells that can self-renew and differentiate. The EC stem cells, which can be isolated from normal pluripotent stem cells by applying similar biomarkers, may participate in promoting esophageal tumorigenesis through renewal and repair. In this review, major emphasis is given to CSC markers, altered CSC-specific pathways, and molecular targeting agents currently available to target CSCs of esophageal cancer. The roles of numerous markers (CD44, aldehyde dehydrogenase, CD133, and ATP-binding cassette subfamily G member 2) and developmental signaling pathways (Wnt/β-catenin, Notch, hedgehog, and Hippo) in isolating esophageal CSCs are discussed in detail. Targeting CSCs can be a logical strategy to treat EC, as these cells are responsible for carcinoma recurrence and chemoradiation resistance.

The tumor microenvironment in esophageal cancer

Esophageal cancer is a deadly disease, ranking sixth among all cancers in mortality. Despite incremental advances in diagnostics and therapeutics, esophageal cancer still carries a poor prognosis, and thus there remains a need to elucidate the molecular mechanisms underlying this disease. There is accumulating evidence that a comprehensive understanding of the molecular composition of esophageal cancer requires attention to not only tumor cells but also the tumor microenvironment, which contains diverse cell populations, signaling factors, and structural molecules that interact with tumor cells and support all stages of tumorigenesis. In esophageal cancer, environmental exposures can trigger chronic inflammation, which leads to constitutive activation of pro-inflammatory signaling pathways that promote survival and proliferation. Anti-tumor immunity is attenuated by cell populations such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), as well as immune checkpoints like programmed death-1 (PD-1). Other immune cells such as tumor-associated macrophages can have other pro-tumorigenic functions, including the induction of angiogenesis and tumor cell invasion. Cancer-associated fibroblasts secrete growth factors and alter the extracellular matrix (ECM) to create a tumor niche and enhance tumor cell migration and metastasis. Further study of how these TME components relate to the different stages of tumor progression in each esophageal cancer subtype will lead to development of novel and specific TME-targeting therapeutic strategies, which offer considerable potential especially in the setting of combination therapy.

Matrigel: from discovery and ECM mimicry to assays and models for cancer research

The basement membrane is an important extracellular matrix that is found in all epithelial and endothelial tissues. It maintains tissue integrity, serves as a barrier to cells and to molecules, separates different tissue types, transduces mechanical signals, and has many biological functions that help to maintain tissue specificity. A well-defined soluble basement membrane extract, termed BME/Matrigel, prepared from an epithelial tumor is similar in content to authentic basement membrane, and forms a hydrogel at 24-37°C. It is used in vitro as a substrate for 3D cell culture, in suspension for spheroid culture, and for various assays, such as angiogenesis, invasion, and dormancy. In vivo, BME/Matrigel is used for angiogenesis assays and to promote xenograft and patient-derived biopsy take and growth. Studies have shown that both the stiffness of the BME/Matrigel and its components (i.e. chemical signals) are responsible for its activity with so many different cell types. BME/Matrigel has widespread use in assays and in models that improve our understanding of tumor biology and help define therapeutic approaches.

Knock-down of ABCE1 gene induces G1/S arrest in human oral cancer cells

PURPOSE

This study aims to explore the clinical characteristics of ATP binding cassette E1 (ABCE1) in oral squamous cell carcinomas (OSCC) and its roles in the proliferation, invasiveness, migration and apoptosis of the human oral squamous cell carcinoma cells CAL-27.

METHODS

The expression of ABCE1 and its target protein-RNase L, were first studied in tumor tissues of OSCC and adjacent non-tumor tissues. Moreover, CAL-27cells were transfected by ABCE1-specific shRNA, then MTT assay, the transwell and scratch assay were used to study cell proliferation and migration activity; the apoptosis rate and cell cycle distribution were tested by flow cytometry. Western blot and RT-PCR assay were adopted to measure their silencing efficacy.

RESULTS

ABCE1 expression is low in the adjacent non-tumor tissues while the expression is high in the oral cancer; the expression is reversely proportional to the differentiation degrees. The expression of RNaseL was in contrary to ABCE1. After transfected with ABCE1-siRNA, the proliferation, invasiveness and migration capabilities of cells decreased significantly whilst the apoptosis rate enhanced greatly (P < 0.01). Meanwhile, the expression of ABCE1 in CAL-27 cells was blocked (P < 0.01) while the expression of RNase L increased significantly (P < 0.01).

CONCLUSION

ABCE1 is closely connected with the pathogenesis and development of oral cancer, which acts through the cellular pathways of 2-5A/RNase L.

Expression of BAG-1 is closely related to cell differentiation and TNM stage in esophageal cancer and its downregulation inhibits the proliferation and invasion of human esophageal carcinoma cells

The aim of the present study was to explore the correlation of BAG-1 with clinical characteristics of esophageal cancer and its effects on the proliferation, invasion and apoptosis of the esophageal carcinoma cell line Eca109. Therefore, the expression of BAG-1 was assessed in esophageal carcinoma tumor tissues and adjacent normal esophageal tissues. The siRNA vector of BAG-1 was constructed and transfected into the Eca109 cell line, and then fluorescence microscopy was used to evaluate the transfection efficiency. MTT and Transwell assays were used to study cell proliferation and invasive activity, and the apoptosis rate was assessed by flow cytometry. Western blotting was adopted to assess the silencing efficiency and expression of related gene bcl-2. The results revealed that BAG-1 expression was low in the adjacent normal esophageal tissues while expression was high in the esophageal carcinoma tissues. After Eca109 cells were transfected with BAG-1-siRNA, the proliferation and invasive capabilities of the cells were significantly decreased while the apoptosis rate was greatly enhanced (P<0.01). When the expression of BAG-1 in the Eca109 cells was downregulated, the expression of bcl-2 was significantly abated (P<0.05). In conclusion, BAG-1 is closely connected with the pathogenesis and development of esophageal carcinoma, which may act through affecting bcl-2.

Study of β-catenin, E-cadherin and vimentin in oral squamous cell carcinoma with and without lymph node metastases

Abstract

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6506095201182002.

Depleting ABCE1 expression induces apoptosis and inhibits the ability of proliferation and migration of human esophageal carcinoma cells

OBJECTIVE

This study aims to explore the clinical characteristics of ABCE1 in esophageal cancers and its roles in the proliferation, invasiveness, migration and apoptosis of the esophageal carcinoma Eca109 cell line.

METHODS

The expression of ABCE1 and its target protein-RNase L, were first studied in tumor tissues of esophageal carcinoma and adjacent non-tumor tissues. The siRNA green fluorescent protein (GFP) expression vector of ABCE1 was prepared and transfected into the esophageal carcinoma Eca109 cells, then the fluorescence microscope was used to study the transfection efficiency. The MTT assay, cell invasion, the transwell and scratch assay were used to study cell proliferation and migration activity; the apoptosis rate was tested by flow cytometry. Western blot and RT-PCR assay were adopted to measure their silencing efficacy.

RESULTS

ABCE1 expression is low in the adjacent non-tumor tissues while the expression is high in the esophageal carcinoma; the expression is reversely proportional to the differentiation degrees. The expression of RNase L was in contrary to ABCE1. After transfected with ABCE1-siRNA, the proliferation, invasiveness and migration capabilities of cells decreased significantly whilst the apoptosis rate enhanced greatly (P<0.01). Meanwhile, the expression of ABCE1 in Eca109 cells was blocked (P<0.01) while the expression of RNase L increased significantly (P<0.01).

CONCLUSION

ABCE1 is closely connected with the pathogenesis and development of esophageal carcinoma, which act through the cellular pathways of 2-5A/RNase L.

The effect and mechanism of CXCR4 silencing on metastasis suppression of human glioma U87 cell line

Tumor metastasis is the major cause of treatment failure and poor prognosis of glioma. Inhibiting metastasis has become an important therapeutic strategy for glioma treatment. CXCR4 has been proved to play an important role in the occurrence and development of tumors. In order to illustrate the effect of CXCR4 on glioma metastasis, we investigated the role of CXCR4 in U87 cells metastasis based on the CXCR4 silencing tumor cells. In this study, we found that CXCR4 silencing could suppress U87 cells invasion and adhesion potential, production of TGF-β1, IL-6, and IL-8, and blocked the G0/G1 phase of the cell cycle. We also found that CXCR4 silencing could up-regulate the mRNA and protein expression of p53, p21, and E-cadherin, and down-regulate the mRNA and protein expression of CD44 and MMP-2/-9. Meanwhile, CXCR4 silencing could decrease the phosphorylation of p-AKT and transcription activity of NF-κB promoter, and increased the phosphorylation of PTEN. The results provided a new research basis for the further study of CXCR4 gene, the screening of human glioma, as well as the target treatment for glioma and its prognosis.