Placental protein-1 (Plac1) modulates immune tolerance in mammary tumor cells
ABSTRACT: Plac1 is an X-linked (Xq26) trophoblast gene expressed at high levels in the placenta, at low levels in the testis, but not in other normal somatic tissues. However, it is re-expressed in several malignancies, including breast, colon, lung, gastric, liver and endometrial cancers as well as in most human cancer cell lines. Plac1 contains HLA-A2-restricted epitopes capable of eliciting a cytotoxic T lymphocyte (CTL) response against human breast cancer cells, and colorectal cancer patients with a Plac1-specific CTL response demonstrate long-term survival. To explore the role of Plac1 in cancer, mouse mammary tumor E0771 cells expressing high levels of Plac1 were transduced with a lentivirus expressing a Plac1 shRNA (E0771/shPlac1). The RNeasy Mini Kit was used to purify total RNA from three independent cell culture samples for gene expression analysis. After isolation in parallel, 1 μg of each of the total RNA from E0771/Scram or E0771/Shplac1 was pooled prior to microarray gene expression analysis. E0771/Scram was considered as control group in this experiment.
Project description:Transcriptional profiling of SAS cells transfected with pLKO.1-LYRIC shRNA-B expression vector (desinaged as B) and control SAS cells (transfected with pLKO.1 vector, designated as CTL). Goal was to determine the effects of LYRIC knockdown on global SAS cells gene expression. Two-condition experiment, SAS cells transfected with pLKO.1-LYRIC shRNA-B expression vector (desinaged as B) v.s. control SAS cells (transfected with pLKO.1 vector, designated as CTL). Biological replicates: 4 control replicates, 4 transfected replicates.
Project description:Efficient processing of target antigens by the ubiquitin-proteasome-system (UPS) is essential for treatment of cancers by T cell therapies. However, immune escape due to impaired expression of IFN-γ-inducible components of the antigen presentation machinery and consequent inefficient processing of HLA-dependent tumor epitopes can be one important reason for failure of such therapies. Here, we show that repeated short-term co-cultures of Melan-A/MART-1 tumor antigen-expressing melanoma cells with Melan-A/MART-1 (26-35)-specific CTL led to the generation of clones resistant to CTL-mediated cell death. To determine which of the UPS components and its associated pathways was responsible for CTL escape; three UKRV-Mel-15a clones were subjected to microarray gene expression analysis. Three UKRV-Mel-15a-derived melanoma clones were isolated following three repeated short-term exposures to Melan-A/MART (26-35) CTL and harvested for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Interactions with the extracellular matrix (ECM) through integrin adhesion receptors provide cancer cells with physical and chemical cues that act in concert with growth factors to support survival and proliferation. Preclinical studies testing beta1 integrin antagonists in (breast) cancer models have shown inhibition of tumor growth and sensitization to radio- or chemotherapy and these strategies are currently evaluated in clinical trials. Here, we show that disruption of beta1 integrin-mediated ECM adhesion attenuates breast tumor growth but dissemination to the lungs from such small tumors can be markedly enhanced. beta1 integrin downregulation induces compensatory upregulation of beta3 integrins, but increased beta3 expression does not lead to enhanced lung metastasis. Instead, beta1 integrin downregulation in human and mouse triple negative, E-cadherin positive breast cancer cells elicits a switch from collective invasion to individual cell migration in 3D ECM. This involves alterations in the TGFbeta-BMP signaling network shifting the balance between miR-200 and ZEB, which causes a block in E-cadherin transcription. The switch is fully reversible: restored beta1 expression reinstates E-cadherin expression and cell cohesion. Moreover, restoring the network at the level of TGFbetaR, ZEB/miR-200 balance, or E-cadherin, restores cohesion and prevents the induction of lung metastasis without affecting tumor growth. These findings reveal that integrin-mediated ECM-attachments regulate a signaling network in control of epithelial characteristics that suppress metastatic spread. This raises concerns with respect to the use of beta1 integrins as cancer drug targets
Project description:Obscurins (~70-870kDa), encoded by the single OBSCN gene, are cytoskeletal proteins originally identified in striated muscles with structural and regulatory roles. Recently, analysis of 13,023 genes in breast and colorectal cancers identified OBSCN as one of the most frequently mutated genes, implicating it in cancer formation. Herein, we studied the expression profile of obscurins in breast, colon and skin cancer cell lines, and their involvement in cell survival. Immunoblot analysis demonstrated significant reduction of obscurins in cancer cells, resulting from decreased mRNA levels and/or the presence of mutant transcripts. In normal epithelium, obscurins localize in cytoplasmic puncta, the cell membrane and the nucleus. Accordingly, subcellular fractionation demonstrated the presence of two novel nuclear isoforms of ~110 and ~120kDa. Non-tumorigenic MCF10A breast epithelial cells stably transduced with shRNAs targeting giant obscurins exhibited increased viability (~30%) and reduced apoptosis (~20%) following exposure to the DNA damaging agent, etoposide. cDNA microarrays followed by Gene Ontology profiling indicated a substantial number of transcripts related to apoptosis and survival are differentially regulated upon obscurin knock-down. Quantitative RT-PCR further indicated that the anti-apoptotic genes BAG-4 and HAX-1 were up-regulated (1.5 and 1.4 fold, respectively), whereas initiator caspase-9 and death caspase-3 transcripts were down-regulated (0.8 and 0.6 fold, respectively). Our findings are the first to pinpoint critical roles for obscurins in cancer development by contributing to the regulation of cell survival. Two-condition experiment: control shRNA- vs. obscurin shRNA-expressing MCF10A cells exposed to 150 uM etoposide. 3 independent replicates per condition.
Project description:Polycystic ovarian syndrome (PCOS) is an endocrine disorder of the reproductive and metabolic axis in women during the reproductive age. In this study, we used a rat model exhibiting reproductive and metabolic abnormalities similar to human PCOS to unravel the molecular mechanisms underlining this complex syndrome. Female Sprague-Dawley rats were implanted with a silicone capsule continuous-releasing 5α-dehydrotestestrone (DHT) per day for 12 weeks to mimic the hyperandrogenic state in women with PCOS, and the control (CTL) groups received an empty capsule. The animals were euthanized at 15 weeks of age and the ovarian cortex tissues of both groups were used for transcriptome profile analysis.
Project description:We evaluated the gene expression profiles of the 1228- and 0316-Glioma-initiating cells (GICs), as well as the original glioblastoma tissues from which they were derived, plus neural stem cells and normal brain tissues. Short- and long-term cultures of 0316-GICs (2 and 6 months, respectively) were also included in the analysis in order to evaluate the potential effects of in vitro culture duration on gene expression. Expressional changes by EZH2 depletion and DZnep treatment were also evaluated.
Project description:The epithelial-mesenchymal transition (EMT), considered essential for metastatic cancer, has been a focus of much research, but important questions remain. Here, we show that silencing or removing H2A.X, a histone H2A variant involved in cellular DNA repair and robust growth, induced mesenchymal-like characteristics including activation of EMT transcription factors, Slug and ZEB1, in HCT116 human colon cancer cells. Ectopic H2A.X re-expression partially reversed these changes; as did silencing Slug and ZEB1. In an experimental metastasis model, the HCT116 parental and H2A.X-null cells exhibited similar metastases levels, but the cells with re-expressed H2A.X exhibited substantially elevated levels. We surmise that H2A.X re-expression led to partial EMT reversal and increased robustness in the HCT116 cells, permitting them to both form tumors and to metastasize. In a human adenocarcinoma panel, H2A.X levels correlated inversely with Slug and ZEB1 levels. Together, these results point to H2A.X as a novel regulator of EMT. 9 samples in total including 4 replicates of control shRNA and 5 replicates of shH2A.X.
Project description:High-resolution mass spectrometry analysis of Interleukin 2 (IL-2) and Janus kinase (JAK) controlled protein phosphorylations in cytotoxic T lymphocytes (CTL) revealed JAKs coupled IL-2 receptors to diverse and complex serine/threonine kinase-substrate networks. These involved intricate, co-ordinated phosphorylation of transcription factors, chromatin regulators within the nuclear environment, cytosolic mRNA translational machinery, regulators of GTPases, vesicle trafficking proteins and the actin and microtubule cytoskeleton. We also identified an IL-2-JAK independent SRC family Tyr kinase controlled signaling network that regulates ~10% of the CTL phosphoproteome. One key signaling pathway in CTL is mediated by phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and the serine/threonine kinase AKT. Strikingly, SRC family kinase dependent but JAK independent signaling controlled PIP3 levels and AKT activity in CTL. IL-2-JAK controlled signaling pathways thus coordinate with IL-2 independent networks of protein phosphorylation to program CTL fate.
Project description:The transcription factor GATA3 is essential for luminal cell differentiation during mammary gland development and critical for formation of the luminal subtypes of breast cancer. Ectopic expression of GATA3 promoted global alterations of the transcriptome of basal triple-negative breast cancer cells resulting in molecular and cellular changes associated with a more differentiated, luminal tumor subtype and a concomitant reduction in primary tumor growth, lung metastasis, and macrophage recruitment at the metastatic site. Importantly, we demonstrate that the inhibition of metastases by GATA3 results from the suppression of lysyl oxidase (LOX) expression, a metastasis promoting matrix protein that affects cell proliferation, cross-linking of extracellular collagen types, and establishment of the metastatic niche. There are 2 samples sent in triplicates.
Project description:In order to investigate the involvement of Hsp27 in splicing, we performed a whole-genome exonic expression profiling of the castration-resistant prostate cancer PC-3 cells treated by Hsp27-siRNA or CTL-siRNA (both in biological duplicates).