Background: The epithelial-mesenchymal transition (EMT) has been implicated as an important process in tumor cell invasion, metastasis, and drug resistance. The transcription factor brachyury has recently been described as a driver of EMT of human carcinoma cells.
Methods: Brachyury mRNA and protein expression was analyzed in human breast carcinomas and benign tissues.
The embryonic T-box transcription factor brachyury is aberrantly expressed in a range of human tumors. Previous studies have demonstrated that brachyury is a driver of the epithelial-mesenchymal transition (EMT), a process associated with cancer progression. Brachyury expression in human tumor cells enhances tumor invasiveness in vitro and metastasis in vivo, and induces resistance to various conventional therapeutics including chemotherapy and radiation.
View Article and Find Full Text PDFPurpose: The epithelial-mesenchymal transition (EMT) is emerging as a critical factor for the progression and metastasis of carcinomas, as well as drug resistance. The T-box transcription factor Brachyury has been recently characterized as a driver of EMT in human carcinoma cells. The purpose of this study was to characterize Brachyury as a potential target for lung cancer therapy.
View Article and Find Full Text PDFThe epithelial-mesenchymal transition (EMT) is thought to be a critical step along the metastasis of carcinomas. In addition to gaining motility and invasiveness, tumor cells that undergo EMT also acquire increased resistance to many traditional cancer treatment modalities, including chemotherapy and radiation. As such, EMT has become an attractive, potentially targetable process for therapeutic interventions against tumor metastasis.
View Article and Find Full Text PDFThe switch of tumor cells from an epithelial to a mesenchymal-like phenotype [designated as epithelial-to-mesenchymal transition (EMT)] is known to induce tumor cell motility and invasiveness, therefore promoting metastasis of solid carcinomas. Although multiple studies have focused on elucidating the signaling events that initiate this phenotypic switch, there has been so far no characterization of the pattern of soluble mediators released by tumor cells undergoing EMT, and the potential impact that this phenotypic switch could have on the remodeling of the tumor microenvironment. Here we show that induction of EMT in human carcinoma cells via overexpression of the transcription factor Brachyury is associated with enhanced secretion of multiple cytokines, chemokines, and angiogenic factors and, in particular, with the induction of the IL-8/IL-8R axis.
View Article and Find Full Text PDFThe switch of carcinoma cells from an epithelial to a mesenchymal-like phenotype, via a process designated 'epithelial-to-mesenchymal transition (EMT),' has been recognized as a relevant step in the metastasis of solid tumors. Additionally, this phenotypic switch of carcinoma cells has been associated with the acquisition of tumor resistance mechanisms that reduce the antitumor effects of radiation, chemotherapy and some small-molecule-targeted therapies. As multiple signaling pathways and transcriptional regulators that play a role in this phenotypic switch are being identified, novel strategies can be designed to specifically target tumor cells with this metastatic and resistant phenotype.
View Article and Find Full Text PDFAdenoviral transduction with CD40L and poxviral transduction with B7-1, ICAM-1, and LFA-3 (TRICOM) have been used to enhance the antigen-presenting capacity of chronic lymphocytic leukemia (CLL) cells. This study compares the same vector (modified vaccinia virus strain Ankara (MVA)) encoding CD40L or TRICOM for its ability to enhance the immunogenicity of CLL cells. CLL cells from some patients showed differential responses to each vector in terms of induction of autologous T-cell responses.
View Article and Find Full Text PDFMetastatic disease is responsible for the majority of human cancer deaths. Understanding the molecular mechanisms of metastasis is a major step in designing effective cancer therapeutics. Here we show that the T-box transcription factor Brachyury induces in tumor cells epithelial-mesenchymal transition (EMT), an important step in the progression of primary tumors toward metastasis.
View Article and Find Full Text PDFIn chronic lymphocytic leukemia (CLL), malignant B cells and nonmalignant T cells exhibit dysfunction. We previously demonstrated that infection of CLL cells with modified vaccinia Ankara (MVA) expressing the costimulatory molecules B7-1, ICAM-1, and LFA-3 (designated TRICOM) increased expression of these costimulatory molecules on the surface of CLL cells and thus augmented their antigen-presenting capability. Here, we evaluate the effect of MVA-TRICOM-modified CLL cells on T cells.
View Article and Find Full Text PDFPurpose: The primary objective of this phase I study was to evaluate the clinical safety of a vaccine using recombinant vaccinia virus (prime) and recombinant fowlpox virus (boost) in combination with granulocyte-macrophage colony-stimulating factor in patients with prostate cancer. The vaccines contained transgenes for prostate specific antigen, a triad of co-stimulatory molecules and a tumor antigen whose amino acid sequence had been modified to enhance its immunogenicity. Secondary end points were immunological and clinical responses, changes in prostate specific antigen velocity, and the kinetics of vaccinia virus clearance from the vaccination site, serum, peripheral blood mononuclear cells, urine and saliva.
View Article and Find Full Text PDFCD4+CD25+Foxp3+ regulatory T (Treg) cells have been implicated in the lack of effective antitumor immunity. Denileukin diftitox (DAB(389)IL-2), a fusion protein of interleukin 2 (IL-2) and diphtheria toxin, provides a means of targeting Treg cells. In this study, we examined (1) the effect of denileukin diftitox on the deletion of Treg cells in various lymphoid compartments and (2) the dose scheduling of denileukin diftitox in combination with a recombinant poxviral vaccine to enhance antigen-specific immune responses.
View Article and Find Full Text PDFPurpose: Identification of tumor antigens is essential in advancing immune-based therapeutic interventions in cancer. Particularly attractive targets are those molecules that are selectively expressed by malignant cells and that are also essential for tumor progression.
Experimental Design And Results: We have used a computer-based differential display analysis tool for mining of expressed sequence tag clusters in the human Unigene database and identified Brachyury as a novel tumor antigen.
LPS-activated B cells, transduced with IgG fusion proteins, are highly tolerogenic APCs. To analyze the mechanisms for this B cell-delivered gene therapy, we first followed the fate of CFSE-labeled B cell blasts. These cells primarily localized to the spleen, where a small population persisted for at least 1 mo after injection.
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