A perylene derivative regulates HIF-1α and Stat3 signaling pathways.

It is becoming increasingly evident that improving the cure rate of many cancers will require treatment regimens hit more than one validated tumor targets. Developing an anti-cancer agent that targets two oncoproteins simultaneously is a promising strategy for accomplishing this goal. It would be expected to promote drug efficacy, reduce therapy-resistant without introducing additional toxic side effects.

Combined treatment targeting HIF-1α and Stat3 is a potent strategy for prostate cancer therapy.

Background: The Stat3 pathway and the hypoxia-sensing pathway are both up-regulated in prostate cancer. Stat3 is a specific regulator of pro-carcinogenic inflammation and represents a promising therapeutic target. Hypoxia-inducible factor-1 (HIF-1)α, which mediates the cellular response to hypoxia, has been demonstrated to be over-expressed in many human cancers and is associated with poor prognosis and treatment failure in clinic.

G-rich oligonucleotides inhibit HIF-1alpha and HIF-2alpha and block tumor growth.

Hypoxia-inducible factor-1 (HIF-1) plays crucial roles in tumor promotion by upregulating its target genes, which are involved in energy metabolism, angiogenesis, cell survival, invasion, metastasis, and drug resistance. The HIF-1alpha subunit, which is regulated by O2-dependent hydroxylation, ubiquitination, and degradation, has been identified as an important molecular target for cancer therapy. We have rationally designed G-rich oligodeoxynucleotides (ODNs) as inhibitors of HIF-1alpha for human cancer therapy.

A G-quartet oligonucleotide blocks glycoprotein Ib-mediated platelet adhesion and aggregation under flow conditions.

Platelets arrest bleeding by adhering to and aggregating on the subendothelium exposed at the site of vessel injury. This process is initiated by the interaction between the subendothelium von Willebrand factor (VWF) and the glycoprotein (GP) Ib-IX-V complex on platelets. However, the same interaction also results in thrombosis at the site of a ruptured atherosclerotic plaque.

T40214/PEI complex: a potent therapeutics for prostate cancer that targets STAT3 signaling.

Background: Prostate cancer (PC) is the most common cancer among men in American and the second leading cause of cancer death. The treatment options employed for patients with advanced and metastatic PC are limited. As a critical mediator of oncogenic signaling, STAT3 is active in 82% of patients with PC.

High levels of circulating CD34 cells, dacrocytes, clonal hematopoiesis, and JAK2 mutation differentiate myelofibrosis with myeloid metaplasia from secondary myelofibrosis associated with pulmonary hypertension.

We studied 25 patients with myelofibrosis with myeloid metaplasia and 19 patients with secondary myelofibrosis associated with pulmonary hypertension (PH). In these 2 groups, we compared the peripheral-blood CD34 count, the clonality of granulocytes and platelets in peripheral blood, the mutational status of the JAK2 kinase gene, and the morphology of the peripheral blood and bone marrow. We found that the following were distinctive features of myelofibrosis with myeloid metaplasia but not of secondary myelofibrosis due to PH: high circulating CD34 cell count, the presence of clonal platelets and granulocytes and of peripheral-blood dacrocytes, and a JAK2 1849G>T (V617F) mutation.

Heterogeneity of the molecular biology of methemoglobinemia: a study of eight consecutive patients.

Congenital methemoglobinemia can be caused by mutations involving five different genes. We studied the etiology and molecular biology of eight consecutive patients with methemoglobinemia. Four had b5R mutations; two were novel.

Congenital polycythemia with homozygous and heterozygous mutations of von Hippel-Lindau gene: five new Caucasian patients.

We report on five Caucasian patients with congenital polycythemia and mutations of the von Hipple-Lindau (VHL) gene: a compound heterozygote for the novel exon 1 (VHL 235C->T) and previously reported VHL 562C->G mutations; three homozygotes for Chuvash VHL 598C->T mutation; and a heterozygote for VHL 523->G mutation who also has ataxia-telangiectasia; a rare autosomal disease of childhood onset.

Identification of a human mutation of DMT1 in a patient with microcytic anemia and iron overload.

Divalent metal transporter 1 (DMT1) is a transmembrane protein crucial for duodenal iron absorption and erythroid iron transport. DMT1 function has been elucidated largely in studies of the mk mouse and the Belgrade rat, which have an identical single nucleotide mutation of this gene that affects protein processing, stability, and function. These animals exhibit hypochromic microcytic anemia due to impaired intestinal iron absorption, and defective iron utilization in red cell precursors.

Instability of PRV-1 mRNA: a factor to be considered in PRV-1 quantification for the diagnosis of polycythemia vera.

High expression of PRV-1 mRNA in granulocytes has been proposed as a new diagnostic marker for polycythemia vera. We used real-time reverse transcription polymerase chain reaction (RT-PCR) to measure the levels of PRV-1 mRNA, GAPDH mRNA and 18S rRNA in granulocytes obtained from blood samples processed 2, 24 and 48 hours after collection and observed a significant decrease of PRV-1 levels after 24 and 48 hours. The instability of PRV-1 mRNA may affect the diagnostic value of the PRV-1 test in blood samples stored for extended periods.

The worldwide distribution of the VHL 598C>T mutation indicates a single founding event.

The first congenital defect of hypoxia-sensing homozygosity for VHL 598C>T mutation was recently identified in Chuvash polycythemia. Subsequently, we found this mutation in 11 unrelated individuals of diverse ethnic backgrounds. To address the question of whether the VHL 598C>T substitution occurred in a single founder or resulted from recurrent mutational events in human evolution, we performed haplotype analysis of 8 polymorphic markers covering 340 kb spanning the VHL gene on 101 subjects bearing the VHL 598C>T mutation, including 72 homozygotes (61 Chuvash and 11 non-Chuvash) and 29 heterozygotes (11 Chuvash and 18 non-Chuvash), and 447 healthy unrelated individuals from Chuvash and other ethnic groups.

Mutations of von Hippel-Lindau tumor-suppressor gene and congenital polycythemia.

The von Hippel-Lindau (pVHL) protein plays an important role in hypoxia sensing. It binds to the hydroxylated hypoxia-inducible factor 1 alpha (HIF-1 alpha) and serves as a recognition component of an E3-ubiquitin ligase complex. In hypoxia or secondary to a mutated VHL gene, the nondegraded HIF-1 alpha forms a heterodimer with HIF-beta and leads to increased transcription of hypoxia-inducible genes, including erythropoietin (EPO).

Discrimination of polycythemias and thrombocytoses by novel, simple, accurate clonality assays and comparison with PRV-1 expression and BFU-E response to erythropoietin.

Essential thrombocythemia (ET) and polycythemia vera (PV) are clonal myeloproliferative disorders that are often difficult to distinguish from other causes of elevated blood cell counts. Assays that could reliably detect clonal hematopoiesis would therefore be extremely valuable for diagnosis. We previously reported 3 X-chromosome transcription-based clonality assays (TCAs) involving the G6PD, IDS, and MPP1 genes, which together were informative in about 65% of female subjects.

Disruption of oxygen homeostasis underlies congenital Chuvash polycythemia.

Chuvash polycythemia is an autosomal recessive disorder that is endemic to the mid-Volga River region. We previously mapped the locus associated with Chuvash polycythemia to chromosome 3p25. The gene associated with von Hippel-Lindau syndrome, VHL, maps to this region, and homozygosity with respect to a C-->T missense mutation in VHL, causing an arginine-to-tryptophan change at amino-acid residue 200 (Arg200Trp), was identified in all individuals affected with Chuvash polycythemia.

Mutations in the VHL gene in sporadic apparently congenital polycythemia.

The congenital polycythemic disorders with elevated erythropoietin (Epo) have been until recently an enigma, and abnormality in the hypoxia-sensing pathway has been hypothesized as a possible mechanism. The tumor suppressor von Hippel-Lindau (VHL) participates in the hypoxia-sensing pathway, as it binds to the proline-hydroxylated form of the hypoxia-inducible factor 1alpha (HIF-1alpha) and mediates its ubiquitination and proteosomal degradation. The loss of VHL function may result in the accumulation of HIF-1alpha and overproduction of HIF-1 downstream target genes including Epo.

N-(4-hydroxyphenyl)retinamide (4-HPR) modulates GADD45 expression in radiosensitive bladder cancer cell lines.

We previously demonstrated that N-(4-hydroxyphenyl)retinamide (4-HPR) and gamma-irradiation, when used in combination, had a synergistic effect in inducing apoptosis in bladder cancer cells, suggesting that 4-HPR may increase radiosensitivity in bladder cancer cells. To unravel molecular correlates in this radiosensitizing effect of 4-HPR, we examined the baseline and 4-HPR-induced expression of GADD45 to elucidate possible mechanisms by which 4-HPR enhanced the effect of gamma-irradiation in three bladder cancer cell lines. To investigate the role of p53 in mediating the radiosensitizing effect of 4-HPR, we also examined mutations in exons 5-9 by using direct sequencing and the levels of p53 expression by using RT-PCR and Western blot, before and after treatment with 4-HPR in these bladder cancer cell lines.

Potassium-dependent folding: a key to intracellular delivery of G-quartet oligonucleotides as HIV inhibitors.

Several groups have demonstrated that G-rich oligonucleotides forming G-quartet structures display activity as potential drugs, such as potent HIV inhibitors. The delivery of G-quartet oligonucleotides to their intracellular targets is a key obstacle to overcome for their clinical success. Here we have developed a novel system to deliver G-rich oligonucleotides into the cell nucleus, e.

Acquired uniparental disomy of chromosome 9p is a frequent stem cell defect in polycythemia vera.

Objective: Clonal stem cell proliferation and increased erythrocyte mass are hallmarks of the myeloproliferative disorder polycythemia vera (PV). The molecular basis of PV is unknown.

Methods: We carried out a genome-wide screening for loss of heterozygosity (LOH) and analyzed candidate genes within the LOH loci.