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1.
Cells ; 13(3)2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38334610

ABSTRACT

Brain tumors represent a heterogeneous group of neoplasms characterized by a high degree of aggressiveness and a poor prognosis. Despite recent therapeutic advances, the treatment of brain tumors, including glioblastoma (GBM), an aggressive primary brain tumor associated with poor prognosis and resistance to therapy, remains a significant challenge. Receptor tyrosine kinases (RTKs) are critical during development and in adulthood. Dysregulation of RTKs through activating mutations and gene amplification contributes to many human cancers and provides attractive therapeutic targets for treatment. Under physiological conditions, the Met RTK, the hepatocyte growth factor/scatter factor (HGF/SF) receptor, promotes fundamental signaling cascades that modulate epithelial-to-mesenchymal transition (EMT) involved in tissue repair and embryogenesis. In cancer, increased Met activity promotes tumor growth and metastasis by providing signals for proliferation, survival, and migration/invasion. Recent clinical genomic studies have unveiled multiple mechanisms by which MET is genetically altered in GBM, including focal amplification, chromosomal rearrangements generating gene fusions, and a splicing variant mutation (exon 14 skipping, METex14del). Notably, MET overexpression contributes to chemotherapy resistance in GBM by promoting the survival of cancer stem-like cells. This is linked to distinctive Met-induced pathways, such as the upregulation of DNA repair mechanisms, which can protect tumor cells from the cytotoxic effects of chemotherapy. The development of MET-targeted therapies represents a major step forward in the treatment of brain tumours. Preclinical studies have shown that MET-targeted therapies (monoclonal antibodies or small molecule inhibitors) can suppress growth and invasion, enhancing the efficacy of conventional therapies. Early-phase clinical trials have demonstrated promising results with MET-targeted therapies in improving overall survival for patients with recurrent GBM. However, challenges remain, including the need for patient stratification, the optimization of treatment regimens, and the identification of mechanisms of resistance. This review aims to highlight the current understanding of mechanisms underlying MET dysregulation in GBM. In addition, it will focus on the ongoing preclinical and clinical assessment of therapies targeting MET dysregulation in GBM.


Subject(s)
Antineoplastic Agents , Brain Neoplasms , Glioblastoma , Humans , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogene Proteins c-met/metabolism , Glioblastoma/drug therapy , Glioblastoma/genetics , Glioblastoma/metabolism , Signal Transduction , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Antineoplastic Agents/pharmacology
2.
Viruses ; 15(12)2023 12 16.
Article in English | MEDLINE | ID: mdl-38140689

ABSTRACT

Baloxavir marboxil (baloxavir) is an FDA-approved inhibitor of the influenza virus polymerase acidic (PA) protein. Here, we used next-generation sequencing to compare the genomic mutational profiles of IAV H1N1 and H3N2, and IBV wild type (WT) and mutants (MUT) viruses carrying baloxavir resistance-associated substitutions (H1N1-PA I38L, I38T, and E199D; H3N2-PA I38T; and IBV-PA I38T) during passaging in normal human bronchial epithelial (NHBE) cells. We determined the ratio of nonsynonymous to synonymous nucleotide mutations (dN/dS) and identified the location and type of amino acid (AA) substitutions that occurred at a frequency of ≥30%. We observed that IAV H1N1 WT and MUT viruses remained relatively stable during passaging. While the mutational profiles for IAV H1N1 I38L, I38T, and E199D, and IBV I38T MUTs were relatively similar after each passage compared to the respective WTs, the mutational profile of the IAV H3N2 I38T MUT was significantly different for most genes compared to H3N2 WT. Our work provides insight into how baloxavir resistance-associated substitutions may impact influenza virus evolution in natural settings. Further characterization of the potentially adaptive mutations identified in this study is needed.


Subject(s)
Herpesvirus 1, Cercopithecine , Influenza A Virus, H1N1 Subtype , Influenza, Human , Thiepins , Humans , Oxazines/pharmacology , Pyridines/pharmacology , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H3N2 Subtype/metabolism , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/metabolism , Thiepins/pharmacology , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Epithelial Cells/metabolism , Genomics , Viral Proteins/genetics , Nucleotidyltransferases
3.
BMC Med Inform Decis Mak ; 23(1): 217, 2023 10 16.
Article in English | MEDLINE | ID: mdl-37845666

ABSTRACT

BACKGROUND: Lyme disease is one of the most commonly reported infectious diseases in the United States (US), accounting for more than [Formula: see text] of all vector-borne diseases in North America. OBJECTIVE: In this paper, self-reported tweets on Twitter were analyzed in order to predict potential Lyme disease cases and accurately assess incidence rates in the US. METHODS: The study was done in three stages: (1) Approximately 1.3 million tweets were collected and pre-processed to extract the most relevant Lyme disease tweets with geolocations. A subset of tweets were semi-automatically labelled as relevant or irrelevant to Lyme disease using a set of precise keywords, and the remaining portion were manually labelled, yielding a curated labelled dataset of 77, 500 tweets. (2) This labelled data set was used to train, validate, and test various combinations of NLP word embedding methods and prominent ML classification models, such as TF-IDF and logistic regression, Word2vec and XGboost, and BERTweet, among others, to identify potential Lyme disease tweets. (3) Lastly, the presence of spatio-temporal patterns in the US over a 10-year period were studied. RESULTS: Preliminary results showed that BERTweet outperformed all tested NLP classifiers for identifying Lyme disease tweets, achieving the highest classification accuracy and F1-score of [Formula: see text]. There was also a consistent pattern indicating that the West and Northeast regions of the US had a higher tweet rate over time. CONCLUSIONS: We focused on the less-studied problem of using Twitter data as a surveillance tool for Lyme disease in the US. Several crucial findings have emerged from the study. First, there is a fairly strong correlation between classified tweet counts and Lyme disease counts, with both following similar trends. Second, in 2015 and early 2016, the social media network like Twitter was essential in raising popular awareness of Lyme disease. Third, counties with a high incidence rate were not necessarily related with a high tweet rate, and vice versa. Fourth, BERTweet can be used as a reliable NLP classifier for detecting relevant Lyme disease tweets.


Subject(s)
Lyme Disease , Social Media , United States/epidemiology , Humans , Incidence , Machine Learning , Self Report , Lyme Disease/diagnosis , Lyme Disease/epidemiology
4.
PLoS One ; 12(9): e0185644, 2017.
Article in English | MEDLINE | ID: mdl-28961263

ABSTRACT

BACKGROUND: Washington DC has a high burden of HIV with a 2.0% HIV prevalence. The city is a national and international hub potentially containing a broad diversity of HIV variants; yet few sequences from DC are available on GenBank to assess the evolutionary history of HIV in the US capital. Towards this general goal, here we analyze extensive sequence data and investigate HIV diversity, phylodynamics, and drug resistant mutations (DRM) in DC. METHODS: Molecular HIV-1 sequences were collected from participants infected through 2015 as part of the DC Cohort, a longitudinal observational study of HIV+ patients receiving care at 13 DC clinics. Sequences were paired with Cohort demographic, risk, and clinical data and analyzed using maximum likelihood, Bayesian and coalescent approaches of phylogenetic, network and population genetic inference. We analyzed 601 sequences from 223 participants for int (~864 bp) and 2,810 sequences from 1,659 participants for PR/RT (~1497 bp). RESULTS: Ninety-nine and 94% of the int and PR/RT sequences, respectively, were identified as subtype B, with 14 non-B subtypes also detected. Phylodynamic analyses of US born infected individuals showed that HIV population size varied little over time with no significant decline in diversity. Phylogenetic analyses grouped 13.5% of the int sequences into 14 clusters of 2 or 3 sequences, and 39.0% of the PR/RT sequences into 203 clusters of 2-32 sequences. Network analyses grouped 3.6% of the int sequences into 4 clusters of 2 sequences, and 10.6% of the PR/RT sequences into 76 clusters of 2-7 sequences. All network clusters were detected in our phylogenetic analyses. Higher proportions of clustered sequences were found in zip codes where HIV prevalence is highest (r = 0.607; P<0.00001). We detected a high prevalence of DRM for both int (17.1%) and PR/RT (39.1%), but only 8 int and 12 PR/RT amino acids were identified as under adaptive selection. We observed a significant (P<0.0001) association between main risk factors (men who have sex with men and heterosexuals) and genotypes in the five well-supported clusters with sufficient sample size for testing. DISCUSSION: Pairing molecular data with clinical and demographic data provided novel insights into HIV population dynamics in Washington, DC. Identification of populations and geographic locations where clustering occurs can inform and complement active surveillance efforts to interrupt HIV transmission.


Subject(s)
HIV Infections/virology , HIV-1/classification , Phylogeny , Adult , Cohort Studies , District of Columbia , Drug Resistance, Viral , Female , HIV Infections/transmission , Humans , Male , Middle Aged
5.
J Cell Biol ; 214(6): 719-34, 2016 09 12.
Article in English | MEDLINE | ID: mdl-27597754

ABSTRACT

Invadopodia are specialized membrane protrusions that support degradation of extracellular matrix (ECM) by cancer cells, allowing invasion and metastatic spread. Although early stages of invadopodia assembly have been elucidated, little is known about maturation of invadopodia into structures competent for ECM proteolysis. The localized conversion of phosphatidylinositol(3,4,5)-triphosphate and accumulation of phosphatidylinositol(3,4)-bisphosphate at invadopodia is a key determinant for invadopodia maturation. Here we investigate the role of the 5'-inositol phosphatase, SHIP2, and reveal an unexpected scaffold function of SHIP2 as a prerequisite for invadopodia-mediated ECM degradation. Through biochemical and structure-function analyses, we identify specific interactions between SHIP2 and Mena, an Ena/VASP-family actin regulatory protein. We demonstrate that SHIP2 recruits Mena, but not VASP, to invadopodia and that disruption of SHIP2-Mena interaction in cancer cells leads to attenuated capacity for ECM degradation and invasion in vitro, as well as reduced metastasis in vivo. Together, these findings identify SHIP2 as a key modulator of carcinoma invasiveness and a target for metastatic disease.


Subject(s)
Breast Neoplasms/enzymology , Cell Movement , Microfilament Proteins/metabolism , Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases/metabolism , Podosomes/enzymology , Animals , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Adhesion Molecules/metabolism , Cell Line, Tumor , Extracellular Matrix/metabolism , Female , HEK293 Cells , Heterografts , Humans , Male , Mice, Nude , Microfilament Proteins/genetics , Neoplasm Invasiveness , Neoplasm Metastasis , Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases/genetics , Phosphoproteins/metabolism , Podosomes/pathology , Protein Binding , Protein Interaction Domains and Motifs , Protein Transport , Proteolysis , RNA Interference , Signal Transduction , Time Factors , Transfection
6.
Toxins (Basel) ; 7(10): 3960-76, 2015 Sep 29.
Article in English | MEDLINE | ID: mdl-26426050

ABSTRACT

The principal portal for anthrax infection in natural animal outbreaks is the digestive tract. Enteric exposure to anthrax, which is difficult to detect or prevent in a timely manner, could be exploited as an act of terror through contamination of human or animal food. Our group has developed a novel animal model of gastrointestinal (GI) anthrax for evaluation of disease pathogenesis and experimental therapeutics, utilizing vegetative Bacillus anthracis (Sterne strain) administered to A/J mice (a complement-deficient strain) by oral gavage. We hypothesized that a humanized recombinant monoclonal antibody (mAb) * that neutralizes the protective antigen (PA) component of B. anthracis lethal toxin (LT) and edema toxin (ET) could be an effective treatment. Although the efficacy of this anti-anthrax PA mAb has been shown in animal models of inhalational anthrax, its activity in GI infection had not yet been ascertained. We hereby demonstrate that passive immunotherapy with anti-anthrax PA mAb, administered at the same time as gastrointestinal exposure to B. anthracis, prevents lethal sepsis in nearly all cases (>90%), while a delay of up to forty-eight hours in treatment still greatly reduces mortality following exposure (65%). Moreover, passive immunotherapy protects against enteric invasion, associated mucosal injury and subsequent dissemination by gastrointestinal B. anthracis, indicating that it acts to prevent the initial stages of infection. * Expired raxibacumab being cycled off the Strategic National Stockpile; biological activity confirmed by in vitro assay.


Subject(s)
Anthrax/therapy , Antibodies, Monoclonal, Humanized/therapeutic use , Gastroenteritis/therapy , Immunization, Passive/methods , Sepsis/prevention & control , Animals , Anthrax/immunology , Anthrax/microbiology , Antibodies, Monoclonal, Humanized/administration & dosage , Antigens, Bacterial , Bacillus anthracis/drug effects , Bacillus anthracis/immunology , Bacillus anthracis/pathogenicity , Bacterial Toxins/antagonists & inhibitors , Disease Models, Animal , Drug Administration Schedule , Female , Gastroenteritis/immunology , Gastroenteritis/microbiology , Intestinal Mucosa/drug effects , Intestinal Mucosa/immunology , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Mice, Inbred Strains , Sepsis/immunology
7.
J Natl Cancer Inst ; 106(5)2014 May 09.
Article in English | MEDLINE | ID: mdl-24815864

ABSTRACT

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 role of brachyury in breast tumor prognosis and drug resistance and the ability of brachyury-specific T cells to lyse human breast carcinoma cells were also evaluated. Kaplan-Meier analyses were used to evaluate the association between brachyury expression and survival. All statistical tests were two-sided. RESULTS: The level of brachyury expression in breast cancer cells was positively associated with their ability to invade the extracellular matrix, efficiently form mammospheres in vitro, and resist the cytotoxic effect of docetaxel. A comparison of survival among breast cancer patients treated with tamoxifen in the adjuvant setting who had tumors with high vs low brachyury mRNA expression demonstrated that high expression of brachyury is associated as an independent variable with higher risk of recurrence (hazard ratio [HR] = 7.5; 95% confidence interval [CI] = 2.4 to 23.5; P = 5.14×10(-4)) and distant metastasis (HR = 15.2; 95% CI = 3.5 to 66.3; P = 3.01×10(-4)). We also demonstrated that brachyury-specific T cells can lyse human breast carcinoma cells. CONCLUSIONS: The studies reported here provide the rationale for the use of a vaccine targeting brachyury for the therapy of human breast cancer, either as a monotherapy or in combination therapies.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Fetal Proteins/biosynthesis , T-Box Domain Proteins/biosynthesis , Adult , Aged , Aged, 80 and over , Breast Neoplasms/genetics , Cell Line, Tumor , Epithelial-Mesenchymal Transition , Female , Fetal Proteins/genetics , Formaldehyde , Humans , Immunohistochemistry , Middle Aged , Neoplasm Invasiveness , Paraffin Embedding , Prognosis , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , T-Box Domain Proteins/genetics , Tissue Fixation
8.
Cancer Res ; 74(9): 2510-9, 2014 May 01.
Article in English | MEDLINE | ID: mdl-24626094

ABSTRACT

Aberrant expression of the T-box transcription factor brachyury in human carcinomas drives the phenomenon of epithelial-mesenchymal transition (EMT), a phenotypic modulation that facilitates tumor dissemination and resistance to conventional therapies, including chemotherapy and radiotherapy. By generating isogenic cancer cell lines with various levels of brachyury expression, we demonstrate that high levels of brachyury also significantly reduce the susceptibility of cancer cells to lysis by both antigen-specific T cells and natural killer cells. Our results indicated that resistance of brachyury-high tumor cells to immune-mediated attack was due to inefficient caspase-dependent apoptosis, manifested as inefficient nuclear lamin degradation in the presence of activated effector caspases. We correlated this phenomenon with loss of cell-cycle-dependent kinase 1 (CDK1), which mediates lamin phosphorylation. In support of a causal connection, pretreatment of tumor cells with a specific inhibitor of WEE1, a negative regulator kinase of CDK1, could counter the defective apoptosis of tumor cells expressing high levels of brachyury. Thus, our findings suggested that reconstituting CDK1 activity to threshold levels may be sufficient to restore immunosurveillance of mesenchymal-like cancer cells that have escaped previous immune detection or eradication.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Cycle Proteins/metabolism , Cytotoxicity, Immunologic/drug effects , Epithelial-Mesenchymal Transition/drug effects , Nuclear Proteins/metabolism , Protein-Tyrosine Kinases/metabolism , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Animals , Apoptosis , CDC2 Protein Kinase/metabolism , Cell Cycle Proteins/antagonists & inhibitors , Cell Line, Tumor , Drug Screening Assays, Antitumor , Female , Fetal Proteins/metabolism , Humans , Mice , Mice, Inbred C57BL , Neoplasm Transplantation , Nuclear Proteins/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidinones , T-Box Domain Proteins/metabolism , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/physiology , Tumor Escape
9.
Oncotarget ; 4(10): 1777-90, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24125763

ABSTRACT

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. These characteristics, and the selective expression of brachyury for a range of human tumor types vs. normal adult tissues, make brachyury an attractive tumor target. Due to its intracellular localization and the "undruggable" character of transcription factors, available options to target brachyury are currently limited. Here we report on the development and characterization of an immunological platform for the efficient targeting of brachyury-positive tumors consisting of a heat-killed, recombinant Saccharomyces cerevisiae (yeast)-brachyury vector-based vaccine (designated as GI-6301) that expresses the full-length human brachyury protein. We demonstrate that human dendritic cells treated with recombinant yeast-brachyury can activate and expand brachyury-specific CD4+ and CD8+ T cells in vitro that, in turn, can effectively lyse human tumor cells expressing the brachyury protein. Vaccination of mice with recombinant yeast-brachyury is also shown here to elicit brachyury-specific CD4+ and CD8+ T-cell responses, and to induce anti-tumor immunity in the absence of toxicity. Based on these results, a Phase I clinical trial of GI-6301 is currently ongoing in patients with advanced tumors; to our knowledge, this is the first vaccine platform aimed at targeting a driver of tumor EMT that has successfully reached the clinical stage.


Subject(s)
Cancer Vaccines/pharmacology , Epithelial-Mesenchymal Transition/immunology , Fetal Proteins/immunology , T-Box Domain Proteins/immunology , Animals , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cancer Vaccines/immunology , Cell Line, Tumor , Dendritic Cells/immunology , Female , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/immunology , Wound Healing/immunology
10.
Mol Cancer Ther ; 12(9): 1805-15, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23783250

ABSTRACT

The epithelial-mesenchymal transition (EMT) is a process associated with the metastasis of solid tumors as well as with the acquisition of resistance to standard anticancer modalities. A major initiator of EMT in carcinoma cells is TGF-ß, which has been shown to induce the expression of several transcription factors ultimately responsible for initiating and maintaining the EMT program. We have previously identified Brachyury, a T-box transcription factor, as an inducer of mesenchymal features in human carcinoma cells. In this study, a potential link between Brachyury and TGF-ß signaling has been investigated. The results show for the first time that Brachyury expression is enhanced during TGF-ß1-induced EMT in various human cancer cell lines, and that a positive feedback loop is established between Brachyury and TGF-ß1 in mesenchymal-like tumor cells. In this context, Brachyury overexpression is shown to promote upregulation of TGF-ß1 at the mRNA and protein levels, an effect mediated by activation of the TGF-ß1 promoter in the presence of high levels of Brachyury. Furthermore, inhibition of TGF-ß1 signaling by a small-molecule inhibitor of TGF-ß receptor type I decreases Brachyury expression, induces a mesenchymal-to-epithelial transition, and renders cancer cells more susceptible to chemotherapy. This study thus has implications for the future development of clinical trials using TGF-ß inhibitors in combination with other anticancer agents.


Subject(s)
Epithelial-Mesenchymal Transition , Fetal Proteins/metabolism , T-Box Domain Proteins/metabolism , Transforming Growth Factor beta1/metabolism , Antineoplastic Combined Chemotherapy Protocols , Cell Line, Tumor , Cisplatin/therapeutic use , Drug Evaluation, Preclinical , Drug Resistance, Neoplasm/genetics , Epithelial-Mesenchymal Transition/drug effects , Feedback, Physiological , Fetal Proteins/genetics , Gene Expression Regulation, Neoplastic , Humans , Neoplasms/genetics , Neoplasms/metabolism , Phenotype , Pteridines/pharmacology , Pteridines/therapeutic use , Receptors, Transforming Growth Factor beta/antagonists & inhibitors , Signal Transduction/drug effects , T-Box Domain Proteins/genetics , Transforming Growth Factor beta1/antagonists & inhibitors , Vinblastine/analogs & derivatives , Vinblastine/therapeutic use , Vinorelbine
11.
Clin Cancer Res ; 18(14): 3868-79, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22611028

ABSTRACT

PURPOSE: 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. EXPERIMENTAL DESIGN: The expression of Brachyury was evaluated by PCR and by immunohistochemistry in human lung tumors and adult normal tissues. Brachyury gene copy number and promoter methylation status were analyzed in tumor tissues with various levels of Brachyury expression. Lung carcinoma cells' susceptibility to T-cell lysis and EGF receptor (EGFR) kinase inhibition were also evaluated relative to the levels of Brachyury. RESULTS: Our results showed Brachyury protein expression in 41% of primary lung carcinomas, including 48% of adenocarcinomas and 25% of squamous cell carcinomas. With the exception of normal testis and some thyroid tissues, the majority of normal tissues evaluated in this study were negative for the expression of Brachyury protein. Brachyury-specific T cells could lyse Brachyury-positive tumors and the level of Brachyury corresponded to resistance of tumor cells to EGFR kinase inhibition. CONCLUSION: We hypothesize that the elimination of Brachyury-positive tumor cells may be able to prevent and/or diminish tumor dissemination and the establishment of metastases. The ability of Brachyury-specific T-cell lines to lyse Brachyury-positive tumor cells, in vitro, supports the development of Brachyury-based immunotherapeutic approaches for the treatment of lung cancer.


Subject(s)
Epithelial-Mesenchymal Transition , Fetal Proteins , Lung Neoplasms , Neoplasm Invasiveness/genetics , T-Box Domain Proteins , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Disease Progression , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Fetal Proteins/genetics , Fetal Proteins/metabolism , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Neoplasm Metastasis , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism
12.
Semin Oncol ; 39(3): 358-66, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22595058

ABSTRACT

The 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. The process of EMT is driven by a group of transcription factors designated as EMT transcription factors, such as Snail, Slug, Twist, and the recently identified T-box family member, Brachyury. In an attempt to determine which of these drivers of EMT is more amenable to targeted therapies and, in particular, T-cell-mediated immunotherapeutic approaches, we have examined their relative expression levels in a range of human and murine normal tissues, cancer cell lines, and human tumor biopsies. Our results demonstrated that Brachyury is a molecule with a highly restricted human tumor expression pattern. We also demonstrated that Brachyury is immunogenic and that Brachyury-specific CD8(+) T cells expanded in vitro are able to lyse Brachyury-positive tumor cells. We thus propose Brachyury as an attractive target for vaccination strategies designed to specifically target tumor cells undergoing EMT.


Subject(s)
Cancer Vaccines/immunology , Carcinoma/immunology , Epithelial-Mesenchymal Transition/immunology , Fetal Proteins/immunology , T-Box Domain Proteins/immunology , Animals , Cancer Vaccines/genetics , Cancer Vaccines/metabolism , Carcinoma/genetics , Carcinoma/metabolism , Fetal Proteins/genetics , Fetal Proteins/metabolism , Humans , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/immunology , Phenotype , T-Box Domain Proteins/genetics , T-Box Domain Proteins/metabolism
13.
Exp Biol Med (Maywood) ; 236(5): 537-45, 2011 May 01.
Article in English | MEDLINE | ID: mdl-21427233

ABSTRACT

The 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. In particular, this review focuses on the potential use of cancer vaccine strategies to target tumor cells that exhibit a mesenchymal-like phenotype, with an emphasis on the characterization of a novel tumor antigen, Brachyury, which we have identified as a critical regulator of EMT in human cancer cells.


Subject(s)
Carcinoma/pathology , Mesoderm/pathology , Epithelial Cells/pathology , Epithelial-Mesenchymal Transition , Humans , Phenotype , Transcription Factors/metabolism
14.
Hum Gene Ther ; 19(8): 763-73, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18627219

ABSTRACT

Intradermal administration of DNA vaccines encoding luciferase represents a convenient method to assess gene expression in vivo. Gene silencing by intradermal gene gun administration of DNA encoding short hairpin RNA (shRNA) may represent an effective technique for the specific knockdown of gene expression in vivo. In the current study, we characterized luciferase gene expression over time in vivo by noninvasive bioluminescence imaging. Furthermore, we characterized in vivo luciferase gene silencing with DNA encoding shRNA targeting luciferase. We also characterized human papillomavirus type 16 (HPV-16) E7-specific CD8(+) T cell immune responses in mice immunized with E7 DNA and DNA encoding shRNA targeting Fas ligand (FasL), a key proapoptotic signaling protein. Our results indicated that coadministration of DNA encoding shRNA targeting luciferase significantly reduced luciferase expression in mice intradermally administered luciferase DNA. Furthermore, we observed that mice vaccinated with E7-expressing DNA coadministered with DNA encoding shRNA targeting FasL generated significantly enhanced E7-specific CD8(+) cytotoxic T cell responses as well as potent therapeutic antitumor effects against E7-expressing tumors. Thus, intradermal administration of DNA encoding shRNA represents a plausible approach to silence genes in vivo and a potentially useful tool to enhance DNA vaccine potency.


Subject(s)
Cancer Vaccines/immunology , Fas Ligand Protein/genetics , RNA Interference , RNA, Small Interfering/immunology , Vaccines, DNA/immunology , Animals , Biolistics , CD8-Positive T-Lymphocytes/immunology , Cancer Vaccines/genetics , Cells, Cultured , Dendritic Cells/immunology , Female , Flow Cytometry , Gene Expression Regulation , Human papillomavirus 16/immunology , Humans , Imaging, Three-Dimensional , Luciferases, Firefly/genetics , Mice , Mice, Inbred C57BL , Papillomavirus E7 Proteins/genetics , Papillomavirus E7 Proteins/immunology , RNA, Small Interfering/genetics , Spleen/cytology , Spleen/immunology , Transfection , Vaccines, DNA/genetics
15.
J Mol Med (Berl) ; 86(8): 899-908, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18542898

ABSTRACT

There is an urgent need to develop new innovative therapies for the control of cancer. Antigen-specific immunotherapy and the employment of proteasome inhibitors have emerged as two potentially plausible approaches for the control of cancer. In the current study, we explored the combination of the DNA vaccine encoding calreticulin (CRT) linked to human papillomavirus type 16 E7 antigen (CRT/E7) with the proteasome inhibitor, bortezomib, for their ability to generate E7-specific immune responses and antitumor effects in vaccinated mice. We found that the combination of treatment with bortezomib and CRT/E7(detox) DNA generated more potent E7-specific CD8+ T cell immune responses and better therapeutic effects against TC-1 tumors in tumor-bearing mice compared to monotherapy. Furthermore, we found that treatment with bortezomib led to increased apoptosis of TC-1 tumor cells and could render the TC-1 tumor cells more susceptible to lysis by E7-specific CD8+ T cells. Our data have significant implications for future clinical translation.


Subject(s)
Antineoplastic Agents/therapeutic use , Boronic Acids/therapeutic use , Cancer Vaccines/therapeutic use , Protease Inhibitors/therapeutic use , Proteasome Inhibitors , Pyrazines/therapeutic use , T-Lymphocytes, Cytotoxic/immunology , Vaccines, DNA/therapeutic use , Animals , Apoptosis , Bortezomib , Calreticulin/genetics , Cancer Vaccines/administration & dosage , Cancer Vaccines/immunology , Drug Therapy, Combination , Mice , Mice, Inbred C57BL , Papillomavirus E7 Proteins/genetics , Papillomavirus E7 Proteins/immunology , T-Lymphocytes, Cytotoxic/drug effects , Tumor Cells, Cultured , Vaccines, DNA/administration & dosage , Vaccines, DNA/immunology
16.
Vaccine ; 25(45): 7824-31, 2007 Nov 07.
Article in English | MEDLINE | ID: mdl-17931752

ABSTRACT

Intradermal vaccination via gene gun efficiently delivers DNA vaccines into dendritic cells (DCs) of the skin, resulting in the activation and priming of antigen-specific T cells in vivo. We have previously demonstrated that intradermal delivery of DNA vaccines encoding single-chain trimer (SCT) composed of the most immunogenic epitope of human papillomavirus type 16 (HPV-16) E6 protein (aa49-57), beta2-microglobulin, and MHC class I heavy chain (SCT-E6) can bypass antigen processing and lead to stable cell-surface presentation of E6 peptides. We also showed that co-administration of DNA vaccines with DNA encoding anti-apoptotic proteins can prolong the survival of DNA-transduced DCs, resulting in significant enhancement of antigen-specific CD8(+) T cell immune responses. In the current study, we hypothesized that combining the SCT strategy and antiapoptotic strategy may further enhance DNA vaccine potency by augmenting antigen-specific CD8(+) T cell immune responses and antitumor effects in vaccinated mice. Here, we show that C57BL/6 mice vaccinated with SCT-E6 DNA combined with antiapoptotic protein Bcl-xL DNA generated enhanced E6-specific CD8(+) T cell immune responses compared to mice vaccinated with SCT-E6 DNA and a non-functional mutant Bcl-xL (mtBcl-xL) DNA. Furthermore, we show that mice treated with SCT-E6 and Bcl-xL DNA generated enhanced anti-tumor effects against E6-expressing tumor cells (TC-1/Luciferase) compared to mice treated with SCT-E6 and mtBcl-xL DNA.


Subject(s)
Dendritic Cells/drug effects , Drug Administration Routes , Papillomaviridae/immunology , Vaccines, DNA/administration & dosage , Animals , Cell Survival , Dendritic Cells/immunology , Dendritic Cells/physiology , Epitopes/genetics , Epitopes/immunology , Injections, Intradermal , Mice , Mice, Inbred C57BL , Oncogene Proteins, Viral/genetics , Oncogene Proteins, Viral/immunology , Papillomaviridae/genetics , Papillomavirus Vaccines/administration & dosage , Papillomavirus Vaccines/immunology , Repressor Proteins/genetics , Repressor Proteins/immunology , Vaccines, DNA/immunology
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