Project description:AHI-1 is an oncogene often targeted by provirus insertional mutagenesis in murine leukemias and lymphomas. Aberrant expression of human AHI-1 occurs in cutaneous T-cell lymphoma (CTCL) cells and in CD4+CD7- Sezary cells from patients with Sezary syndrome (SS). Stable knockdown of AHI-1 using retroviral-mediated RNA interference in CTCL cells inhibits their transforming activity in vitro and in vivo. To identify genes involved in AHI-1-mediated transformation, microarray analysis was performed to identify differentially expressed genes in AHI-1 suppressed CTCL cells. Fifteen up-regulated and six down-regulated genes were identified and confirmed by Q-RT-PCR. Seven were further confirmed in a microarray analysis of CD4+CD7- Sezary cells from SS patients. HCK and BIN1 emerged as new candidate cooperative genes, with differential protein expression which correlates with observed transcript changes. Interestingly, changes in HCK phosphorylation and biological response to its inhibitor, dasatinib, were observed in AHI-1 suppressed or overexpressed cells. The tumor suppressor BIN1 physically interacts with MYC in CTCL cells, which also exhibit differential MYC protein expression. In addition, aberrant expression of alternative splicing forms of BIN1 was observed in primary and transformed CTCL cells. These findings indicate that HCK and BIN1 may play critical roles in AHI-1-mediated leukemic transformation of human CTCL cells. Experiment Overall Design: Two groups, each with two subgroups, subgroups having 2 or 3 replicates each
Project description:AHI-1 is an oncogene often targeted by provirus insertional mutagenesis in murine leukemias and lymphomas. Aberrant expression of human AHI-1 occurs in cutaneous T-cell lymphoma (CTCL) cells and in CD4+CD7- Sezary cells from patients with Sezary syndrome (SS). Stable knockdown of AHI-1 using retroviral-mediated RNA interference in CTCL cells inhibits their transforming activity in vitro and in vivo. To identify genes involved in AHI-1-mediated transformation, microarray analysis was performed to identify differentially expressed genes in AHI-1 suppressed CTCL cells. Fifteen up-regulated and six down-regulated genes were identified and confirmed by Q-RT-PCR. Seven were further confirmed in a microarray analysis of CD4+CD7- Sezary cells from SS patients. HCK and BIN1 emerged as new candidate cooperative genes, with differential protein expression which correlates with observed transcript changes. Interestingly, changes in HCK phosphorylation and biological response to its inhibitor, dasatinib, were observed in AHI-1 suppressed or overexpressed cells. The tumor suppressor BIN1 physically interacts with MYC in CTCL cells, which also exhibit differential MYC protein expression. In addition, aberrant expression of alternative splicing forms of BIN1 was observed in primary and transformed CTCL cells. These findings indicate that HCK and BIN1 may play critical roles in AHI-1-mediated leukemic transformation of human CTCL cells. Keywords: Cell type comparison
Project description:Myotonic dystrophes (DM), the most common adult muscular dystrophy, are the first recognized examples of RNA-mediated diseases in which expression of mutant RNAs containing expanded CUG or CCUG repeats interfere with the splicing of other mRNAs. Using whole-genome microarrays, we found that alternative splicing of the BIN1 mRNA is altered in DM skeletal muscle tissues, resulting in the expression of an inactive form of BIN1 deprived of phosphoinositide-binding and membrane-tubulating activities. BIN1 is involved in tubular invaginations of the plasma membrane and is essential for biogenesis of the muscle T-tubules, which are specialized skeletal muscle membrane structures essential to correct excitation-contraction (E-C) coupling. Mutations in the BIN1 gene cause centronuclear myopathy (CNM) that shares some histopathological features with DM, and both diseases are characterized by muscle weakness. Consistent with a loss-of-function of BIN1, muscle T-tubules were altered in DM patients, and membrane tubulation was restored upon expression of the correct splicing form of BIN1 in DM muscle cells. By deciphering the mechanism of BIN1 splicing mis-regulation we demonstrate that the splicing regulator, MBNL1, which is sequestered by expanded CUG and CCUG in DM, binds the BIN1 pre-mRNA and regulates directly its alternative splicing. Finally, reproducing BIN1 splicing alteration in mice is sufficient to reproduce the DM features of T-tubule alterations and muscle weakness. We propose that alteration of BIN1 alternative splicing regulation leads to muscle weakness, a predominant pathological feature of DM. Exon-Array analysis of control and CDM1 muscle primary cultures 10 days of differentiation
Project description:Cutaneous T-cell lymphoma (CTCL) develops from clonally expanded CD4+ T cells in a background of chronic inflammation. Dendritic cells (DCs) are potent T-cell stimulators; yet despite DCs’ extensive presence in skin, cutaneous T cells in CTCL do not respond with effective anti-tumor immunity. We evaluated primary T-cell and DC émigrés from epidermal and dermal explant cultures of skin biopsies from CTCL patients (n = 37) and healthy donors (n = 5). Compared with healthy skin, CD4+ CTCL populations contained more T cells expressing PD-1, CTLA-4, and LAG-3; and CD8+ CTCL populations comprised more T cells expressing CTLA-4 and LAG-3. CTCL populations also contained more T cells expressing the inducible T-cell costimulator (ICOS), a marker of T-cell activation. DC émigrés from healthy or CTCL skin biopsies expressed PD-L1, indicating that maturation during migration resulted in PD-L1 expression irrespective of disease. Most T cells did not express PD-L1. Using skin samples from 49 additional CTCL patients for an unsupervised analysis of genome-wide mRNA expression profiles corroborated that advanced T3/T4 stage samples expressed higher levels of checkpoint inhibition genes compared with T1/T2 stage patients or healthy controls. Exhaustion of activated T cells is therefore a hallmark of both CD4+ and CD8+ T cells directly isolated from the lesional skin of patients with CTCL, with a continuum of increasing expression in more advanced stages of disease. These results justify identification of antigens driving T-cell exhaustion and the evaluation of immune checkpoint inhibition to reverse T-cell exhaustion earlier in the treatment of CTCL.
Project description:Cutaneous T-cell lymphomas form a heterogeneous group of non-Hodgkin lymphomas characterized by only poor prognosis in advanced stage. Despite significant progress made in the identification of novel genes and pathways involved in the pathogenesis of cutaneous lymphoma, the therapeutic value of these findings has still to be proven. Here, we demonstrate by gene expression arrays that aurora kinase A is one of highly overexpressed genes of the serine/threonine kinase in CTCL. The finding was confirmed by qualitative RT-PCR, Western blotting and immunohistochemistry in CTCL cell lines and primary patient samples. Moreover, treatment with a specific aurora kinase A inhibitor blocks cell proliferation by inducing cell cycle arrest in G2 phase as well as apoptosis in CTCL cell lines. These new data provide a promising rationale for using aurora kinase A inhibition as a therapeutic modality of CTCL. 14 lesional skin biopsies of different MF patients (patch=3, plaque=6, tumor=4) and 9 healthy controls. Comparison between Cutaneus Tcell Lymphoma Samples and Healthy Control Tissue
Project description:Cutaneous T-cell lymphomas form a heterogeneous group of non-Hodgkin lymphomas characterized by only poor prognosis in advanced stage. Despite significant progress made in the identification of novel genes and pathways involved in the pathogenesis of cutaneous lymphoma, the therapeutic value of these findings has still to be proven. Here, we demonstrate by gene expression arrays that aurora kinase A is one of highly overexpressed genes of the serine/threonine kinase in CTCL. The finding was confirmed by qualitative RT-PCR, Western blotting and immunohistochemistry in CTCL cell lines and primary patient samples. Moreover, treatment with a specific aurora kinase A inhibitor blocks cell proliferation by inducing cell cycle arrest in G2 phase as well as apoptosis in CTCL cell lines. These new data provide a promising rationale for using aurora kinase A inhibition as a therapeutic modality of CTCL.
Project description:We studied MET-transformed human primary osteoblasts (MET-HOBs), which we previously turned into osteosarcoma cells by LV driven over-expression of MET oncogene. We obtained distinct MET transformed HOB clones derived from independent events of transgene integration. To characterise the phenotype of the MET-HOB clones we used oligonucleotide microarrays. Expression profiles of MET-HOBs and parental HOBs were compared.
Project description:We studied MET-transformed human primary osteoblasts (MET-HOBs), which we previously turned into osteosarcoma cells by LV driven over-expression of MET oncogene. We obtained distinct MET transformed HOB clones derived from independent events of transgene integration. To characterise the phenotype of the MET-HOB clones we used oligonucleotide microarrays. Expression profiles of MET-HOBs and osteosarcoma cell lines were compared.
Project description:Cutaneous T-cell lymphomas (CTCL) are the most frequent primary skin lymphomas. Nevertheless, diagnosis of early disease has proven difficult due to a clinical and histological resemblance to benign inflammatory skin diseases. To address if microRNA (miRNA) profiling can discriminate CTCL from benign inflammation, we study miRNA expression in 199 patients with CTCL, peripheral T-cell lymphoma (PTL), and benign skin diseases (psoriasis and dermatitis). Using microarrays we show that the most induced- (miR-326, miR-663b, miR-711) and repressed- (miR-203, miR-205) miRNAs distinguish CTCL from benign skin diseases with > 90% accuracy in a training set of 90 samples and a test set of 58 blinded samples. These miRNAs also distinguish malignant and benign lesions in an independent set of 50 patients with PTL and skin inflammation and in experimental human xenograft mouse models of psoriasis and CTCL. Q-RT-PCR analysis of 104 patients with CTCL and benign skin disorders validates differential expression of 4 out of the 5 miRNAs and confirms previous reports on miR-155 in CTCL. A q-RT-PCR-based classifier consisting of miR-155, miR-203, and miR-205 distinguishes CTCL from benign disorders with high specificity, sensitivity, and a classification accuracy of 95% indicating that miRNAs have a high diagnostic potential in CTCL.