SM04755, a small-molecule inhibitor of the Wnt pathway, as a potential topical treatment for tendinopathy.

The Wnt pathway is upregulated in tendinopathy, affecting inflammation and tenocyte differentiation. Given its potential role in tendinopathy, this signaling pathway may be a relevant target for treatment. The current study examined the therapeutic potential of SM04755, a topical, small-molecule Wnt pathway inhibitor, for the treatment of tendinopathy using in vitro assays and animal models.

The CLK inhibitor SM08502 induces anti-tumor activity and reduces Wnt pathway gene expression in gastrointestinal cancer models.

The Wnt/β-catenin signaling pathway is aberrantly activated in colorectal (CRC) and many other cancers, and novel strategies for effectively targeting it may be needed due to its complexity. In this report, SM08502, a novel small molecule in clinical development for the treatment of solid tumors, was shown to reduce Wnt pathway signaling and gene expression through potent inhibition of CDC-like kinase (CLK) activity. SM08502 inhibited serine and arginine rich splicing factor (SRSF) phosphorylation and disrupted spliceosome activity, which was associated with inhibition of Wnt pathway-related gene and protein expression.

Glycogen synthase kinase 3beta missplicing contributes to leukemia stem cell generation.

Recent evidence suggests that a rare population of self-renewing cancer stem cells (CSC) is responsible for cancer progression and therapeutic resistance. Chronic myeloid leukemia (CML) represents an important paradigm for understanding the genetic and epigenetic events involved in CSC production. CML progresses from a chronic phase (CP) in hematopoietic stem cells (HSC) that harbor the BCR-ABL translocation, to blast crisis (BC), characterized by aberrant activation of beta-catenin within granulocyte-macrophage progenitors (GMP).

Thrombopoietin regulates c-Myb expression by modulating micro RNA 150 expression.

Objective: Mice harboring c-Myb hypomorphic mutations display enhanced thrombopoiesis because of increased numbers of megakaryocytes and their progenitors. Thrombopoietin induces these same effects, which lead us to hypothesize that the hormone acts through modulation of c-Myb expression, as c-Myb levels falls during thrombopoietin-induced megakaryocyte (MK) maturation. Micro RNAs (miRs) downregulate gene expression by binding to the 3' untranslated region (UTR) of specific messenger RNAs (mRNAs); we noted that the 3'UTR of c-Myb contains four miR-150 binding sites.

Selective inhibition of JAK2-driven erythroid differentiation of polycythemia vera progenitors.

Polycythemia Vera (PV) is a myeloproliferative disorder (MPD) that is commonly characterized by mutant JAK2 (JAK2V617F) signaling, erythrocyte overproduction, and a propensity for thrombosis, progression to myelofibrosis, or acute leukemia. In this study, JAK2V617F expression by human hematopoietic progenitors promoted erythroid colony formation and erythroid engraftment in a bioluminescent xenogeneic immunocompromised mouse transplantation model. A selective JAK2 inhibitor, TG101348 (300 nM), significantly inhibited JAK2V617F+ progenitor-derived colony formation as well as engraftment (120 mg/kg) in xenogeneic transplantation studies.

Thrombopoietin (TPO) induces c-myc expression through a PI3K- and MAPK-dependent pathway that is not mediated by Akt, PKCzeta or mTOR in TPO-dependent cell lines and primary megakaryocytes.

Thrombopoietin (TPO) and its receptor (c-Mpl) are the major regulators of megakaryocyte and platelet production and serve a critical and non-redundant role in hematopoietic stem cell (HSC) biology. TPO signals through the Jak-STAT, Ras-Raf-MAPK, and PI3K pathways, and promotes survival, proliferation, and polyploidization in megakaryocytes. The proto-oncogene c-myc also plays an important role in many of these same processes.

Prevalence of chemokine and chemokine receptor polymorphisms in seroprevalent children with symptomatic HIV-1 infection in the United States.

Several chemokines and chemokine receptors are involved in HIV-1 infection, disease progression, and transmission. We studied the prevalence of genetic variations in CCR2, SDF1, and the CCR5 gene and its promoter region at positions 59029, 59353, and 59356 in a seroprevalent cohort of 1057 children with symptomatic HIV-1 infection in the United States. The percentage of children with the CCR5-wt/Delta32 genotype was significantly higher for white, non-Hispanic children (15%) than for Hispanic (6%) or black, non-Hispanic children (4%).

Genetic influence of CCR5, CCR2, and SDF1 variants on human immunodeficiency virus 1 (HIV-1)-related disease progression and neurological impairment, in children with symptomatic HIV-1 infection.

The role that host genetics plays in the modification of the rate of human immunodeficiency virus 1 (HIV-1)-related disease progression was evaluated in a seroprevalent cohort of 1049 children with symptomatic HIV-1 infection who participated in 2 clinical trials in the United States. Variants including CCR2-V64I, CCR5-wt/Delta32, CCR5-59029-G/A, CCR5-59353-T/C, CCR5-59356-C/T, and SDF1-3'-G/A were identified by polymerase chain-reaction genotyping. Children with the CCR5-wt/Delta32 genotype experienced significantly delayed disease progression, including less neurocognitive impairment.