Project description:Lysophosphatidic acid (LPA) and LPA-receptor (LPAR)-activated G-protein alpha subunits encoded by GNAi2, GNA12, and GNA13 play a crucial role in ovarian cancer progression. While the general signaling mechanism regulated by LPA-LPAR-signaling had previously been characterized, the global transcriptomic network regulated by individual G protein alpha-subunits in ovarian cancer pathophysiology remains largely unknown. To define the specific oncogenic networks regulated by LPA-stimulated GNAi2, GNA12, and GNA13 in ovarian cancer, transcriptomic analyses were carried out using SKOV3 cells in which the expression of GNAi2, GNA12, or GNA134 was silenced in an Agilent SurePrint G3 Human Comparative Genomic Hybridization 8x60 microarray platform.
Project description:Lysophosphatidic acid (LPA) acts through high-affinity G protein-coupled receptors to mediate a plethora of physiological and pathological activities associated with tumorigenesis. LPA receptors and autotaxin (ATX/LysoPLD), the primary enzyme producing LPA, are aberrantly expressed in multiple cancer lineages. However, the role of ATX and LPA receptors in the initiation and progression of breast cancer has not been evaluated. We demonstrate that expression of ATX or each edg family LPA receptor in mammary epithelium of transgenic mice is sufficient to induce a high frequency of late-onset, estrogen receptor (ER)-positive, invasive, and metastatic mammary cancer. Thus, ATX and LPA receptors can contribute to the initiation and progression of breast cancer.
Project description:We report that the lysophosphatidic acid receptor 4 (LPAR4) is specifically upregulated on cells exposed to environmental stress or cancer drugs where it promotes stress tolerance, self-renewal, and tumor initiation. We find that ectopic LPAR4-expressing tumors display an enrichment of key extracellular matrix (ECM)-related genes that are established drivers of cancer stemness, and surprisingly do not require stimulation with the canonical LPAR4 ligand, LPA. From this RNAseq data, we observed that LPAR4 promotes a subset of genes, mainly extracellular matrix related genes, independent of its ligand LPA in patient-derived xenograft cells.
Project description:We report the differential gene expression patterns of TILs from two patients after treating the cells with lysophosphatidic acid (LPA) for 2 or 3 hours. Among the common LPA-regulated genes are transcription factors and other immediate early genes as well as T-cell regulatory cell-surface molecules
Project description:Lysophosphatidic acid (LPA) is a bioactive lipid enriched in highly immunosuppressive neoplasms like ovarian cancer (OvCa). While LPA is known to enhance the tumorigenic capacity of malignant cells, the immunomodulatory role of this phospholipid in cancer remains largely unexplored. Here, we report that LPA operates as a negative regulator of type-I interferon (IFN) responses in OvCa. Ablation of the LPAgenerating enzyme autotaxin in OvCa cells reprogrammed the tumor immune microenvironment, extended host survival, and improved the effects of therapies that elicit protective responses driven by type-I IFN. Mechanistically, LPA sensing by dendritic cells triggered PGE2 synthesis that suppressed type-I IFN signaling via autocrine EP4 engagement. Moreover, we identified an LPA-controlled, immune-derived gene signature associated with weak responses to combined PARP inhibition and PD-1 blockade in OvCa patients. Controlling LPA production or sensing in tumors may therefore be useful to improve cancer immunotherapies that rely on robust induction of type-I IFN.
Project description:Autotaxin (ATX, Enpp2) is a secreted lysophospholipase D catalyzing the production of lysophosphatidic acid (LPA), a pleiotropic growth factor-like phospholipid. Upregulated ATX expression has been detected in various chronic inflammatory disorders and different types of cancer; among them increased ATX mRNA or immunohistochemical staining has been suggested in Hepatocellular carcinoma (HCC) patients. Conditional deletion of ATX/Enpp2 specifically from hepatocytes, in AlbEnpp2-/- mice, attenuated the DEN/CCl4-mediated HCC development in mice. To obtain mechanistic insights into the mode of action of the ATX/LPA axis in HCC development, we performed whole liver, genome wide expression profiling of DEN/CCl4-induced HCC upon the genetic deletion of Autotaxin (ATX) in AlbEnpp2-/- mice in comparison with DEN/CCl4-treated and untreated wt littermate mice.
Project description:LPA is a natural bioactive lipid with growth factor-like functions due to activation of series of six G protein-coupled receptors (LPA1-6). In this study we determine the LPA induced early-miRNA expression profile in human breast cancer cell lines MDA-MB-231
Project description:LPA is a natural bioactive lipid with growth factor-like functions due to activation of series of six G protein-coupled receptors (LPA1-6). In this study we determine the LPA induced early-miRNA expression profile in human breast cancer cell lines MDA-MB-231 MDA-MB-231 cells were serum starved for 24h and then stimulated with LPA (1µM) for 45min. The controls were the serum starved unstimulated cells. Three replicates were included in this study.
Project description:Autotaxin (ATX) has been reported to act as a motility and growth factor in a variety of cancer cells. The ATX protein acts as a secreted lysophospholipase D (lysoPLD) by converting lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which signals via G-protein coupled receptors and has important functions in cell migration and proliferation. The current study demonstrates that ATX expression is upregulated and functionally active in FLT3-ITD+ human blasts. ATX expression was also found in normal human CD34+ progenitor cells and selected myeloid and lymphoid subpopulations. Stable transduction of mutant FLT3-ITD increased ATX mRNA in selected cell lines, whereas inhibition of FLT3-ITD signaling by sublethal doses of PKC412 led to a significant down-regulation of ATX. Moreover, results indicate that the Jun N-terminal kinase (JNK) is an important mediator between FLT3 signaling and ATX. In the presence of LPC, ATX expression led to a significant increase of proliferation. LPA caused proliferation of all tested cell lines, regardless of ATX expression and induced chemotaxis in human leukemic cell lines and human CD34+ progenitors. LPC increased chemotaxis, in cells with high expression of endogenous and exogenous ATX, by at least 80% demonstrating the autocrine effect of ATX expression. Inhibition of ATX using a small molecule inhibitor induced selective killing of ATX-expressing cell lines and reduced the motile phenotype observed in this cells. Our data suggest that the production of bioactive LPA through ATX is involved in controlling proliferation and migration during hematopoiesis and that deregulation contributes to the pathogenesis of AML. AML Classes: Molecular/cytogenetic group of acute myeloid leukemia, either internal tandem duplication (FLT3) or FLT3 point mutation (D835) or normal karyotype (NK) or t(8;21) transclocation (t821) or monosomy 7 (mono7) or inversion on chromosome 16 (inv16) or high leukocyte count normal karyotype (HL). FAB (French-American-British) Classification system for acute myeloid leukemia is provided for each sample.