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Biomedical subjects

Haiying Chen

Publications and source records attributed to Haiying Chen.

At least 19 recordsLinked to original sources

Pharmacologic inhibition of SOX9-CDK4 by CYD-4-61 impairs gastric adenocarcinoma growth and amplifies anti-PD-1 response.

Gastric adenocarcinoma (GAC) remains a leading cause of cancer-related mortality, particularly in patients with peritoneal carcinomatosis, for whom effective therapies are limited. We investigated the therapeutic efficacy and molecular mechanism of CYD-4-61, a BAX activator, using human GAC cell lines, patient-derived xenograft models, genetically engineered mouse models, and a syngeneic mouse model. CYD-4-61 potently inhibited tumor cell proliferation, induced apoptosis, and suppressed cancer stem cell-like properties, with enhanced activity in radiation-resistant GAC cells. Mechanistically, CYD-4-61 activated the BAX-caspase pathway, leading to SOX9 protein reduction. Integrated bulk and single-cell transcriptomic analyses identified SOX9-dependent transcriptional programs as major targets of CYD-4-61. Functional rescue experiments together with chromatin immunoprecipitation and CUT&RUN analyses supported CDK4 as a SOX9-regulated gene and demonstrated suppression of the SOX9-CDK4 regulatory axis following CYD-4-61 treatment. In multiple preclinical models, CYD-4-61 significantly inhibited tumor growth and improved the therapeutic response to anti-programmed cell death protein 1 (PD-1) therapy while modulating the tumor immune microenvironment. Clinically, co-expression of SOX9 and CDK4 was associated with diffuse-type GAC and poor patient outcomes. These findings identify the BAX-SOX9-CDK4 axis as an important mechanism contributing to the antitumor activity of CYD-4-61 and provide a strong preclinical rationale for its further development as a therapeutic strategy for aggressive GAC.

Animals↗

Effects of estradiol with micronized progesterone or medroxyprogesterone acetate on risk markers for breast cancer in postmenopausal monkeys.

The addition of the synthetic progestin medroxyprogesterone acetate (MPA) to postmenopausal estrogen therapy significantly increases breast cancer risk. Whether this adverse effect is specific to MPA or characteristic of all progestogens is not known. The goal of this study was to compare the effects of oral estradiol (E2) given with either MPA or micronized progesterone (P4) on risk biomarkers for breast cancer in a postmenopausal primate model. For this randomized crossover trial, twenty-six ovariectomized adult female cynomolgus macaques were divided into social groups and rotated randomly through the following treatments (expressed as equivalent doses for women): (1) placebo; (2) E2 (1 mg/day); (3) E2 + P4 (200 mg/day); and (4) E2 + MPA (2.5 mg/day). Hormones were administered orally, and all animals were individually dosed. Treatments lasted two months and were separated by a one-month washout period. The main outcome measure was breast epithelial proliferation, as measured by Ki67 expression. Compared to placebo, E2 + MPA resulted in significantly greater breast proliferation in lobular (P < 0.01) and ductal (P < 0.01) epithelium, while E2 + P4 did not. Intramammary gene expression of the proliferation markers Ki67 and cyclin B1 was also higher after treatment with E2 + MPA (P < 0.01) but not E2 + P4. Both progestogens significantly attenuated E2 effects on body weight, endometrium, and the TFF1 marker of estrogen receptor activity in the breast. These findings suggest that oral micronized progesterone has a more favorable effect on risk biomarkers for postmenopausal breast cancer than medroxyprogesterone acetate.

Animals↗

Value of recruitment strategies used in a primary care practice-based trial.

PURPOSE: "Physicians-recruiting-physicians" is the preferred recruitment approach for practice-based research. However, yields are variable; and the approach can be costly and lead to biased, unrepresentative samples. We sought to explore the potential efficiency of alternative methods. METHODS: We conducted a retrospective analysis of the yield and cost of 10 recruitment strategies used to recruit primary care practices to a randomized trial to improve cardiovascular disease risk factor management. We measured response and recruitment yields and the resources used to estimate the value of each strategy. Providers at recruited practices were surveyed about motivation for participation. RESULTS: Response to 6 opt-in marketing strategies was 0.40% (53/13290), ranging from 0% to 2.86% by strategy; 33.96% (18/53) of responders were recruited to the study. Of those recruited from opt-out strategies, 8.68% joined the study, ranging from 5.35% to 41.67% per strategy. A strategy that combined both opt-in and opt-out approaches resulted in a 51.14% (90/176) response and a 10.80% (19/90) recruitment rate. Cost of recruitment was $613 per recruited practice. Recruitment approaches based on in-person meetings (41.67%), previous relationships (33.33%), and borrowing an Area Health Education Center's established networks (10.80%), yielded the most recruited practices per effort and were most cost efficient. Individual providers who chose to participate were motivated by interest in improving their clinical practice (80.5%); contributing to CVD primary prevention (54.4%); and invigorating their practice with new ideas (42.1%). CONCLUSIONS: This analysis provides suggestions for future recruitment efforts and research. Translational studies with limited funds could consider multi-modal recruitment approaches including in-person presentations to practice groups and exploitation of previous relationships, which require the providers to opt-out, and interactive opt-in approaches which rely on borrowed networks. These approaches can be supplemented with non-relationship-based opt-out strategies such as cold calls strategically targeted to underrepresented provider groups.

Advertising↗

Growth hormone and IGF-I modulate local cerebral glucose utilization and ATP levels in a model of adult-onset growth hormone deficiency.

Decreases in plasma IGF-I levels that occur with age have been hypothesized to contribute to the genesis of brain aging. However, support for this hypothesis would be strengthened by evidence that growth hormone (GH)/IGF-I deficiency in young animals produces a phenotype similar to that found in aged animals. As a result, we developed a unique model of adult-onset GH/IGF-I deficiency by using dwarf rats specifically deficient in GH and IGF-I. The deficiency in plasma IGF-I is similar to that observed with age (e.g., 50% decrease), and replacement of GH restores levels of IGF-I to that found in young animals with normal GH levels. The present study employs this model to investigate the effects of circulating GH and IGF-I on local cerebral glucose utilization (LCGU). Analysis of LCGU indicated that GH/IGF-I-deficient animals exhibit a 29% decrease in glucose metabolism in many brain regions, especially those involved in hippocampally dependent processes of learning and memory. Similarly, a high correlation between plasma IGF-I levels and glucose metabolism was found in these areas. The deficiency in LCGU was not associated with alterations in GLUT1, GLUT3, or hexokinase activity. A 15% decrease in ATP levels was also found in hippocampus of GH-deficient animals, providing compelling data that circulating GH and IGF-I have significant effects on the regulation of glucose utilization and energy metabolism in the brain. Furthermore, our results provide important data to support the conclusion that deficiencies in circulating GH/IGF-I contribute to the genesis of brain aging.

Adenosine Triphosphate↗

Antibody-induced transplantation tolerance that is dependent on thymus-derived regulatory T cells.

Targeting of the CD45RB isoform by mAb (anti-CD45RB) effectively induces donor-specific tolerance to allografts. The immunological mechanisms underlying the tolerant state remain unclear although some studies have suggested the involvement of regulatory T cells (T-regs). Although their generative pathway remains undefined, tolerance promoting T-regs induced by systemic anti-CD45RB treatment have been assumed to originate in the peripheral immune system. We demonstrate herein that separable effects on the peripheral and central immune compartments mediate graft survival induced by anti-CD45RB administration. In the absence of the thymus, anti-CD45RB therapy is not tolerogenic though it retains peripheral immunosuppressive activity. The thymus is required for anti-CD45RB to produce indefinite graft survival and donor-specific tolerance, and this effect is accomplished through thymic production of donor-specific T-regs. These data reveal for the first time an Ab-based tolerance regimen that relies on the central tolerance pathway.

Adoptive Transfer↗

Quality of cholesterol screening and management with respect to the National Cholesterol Education's Third Adult Treatment Panel (ATPIII) guideline in primary care practices in North Carolina.

BACKGROUND: Adherence to previous national cholesterol guidelines has been low. We assessed whether lipid screening and management was consistent with the National Cholesterol Education's ATPIII in a sample of primary care practices participating in a quality improvement study. METHODS: Demographic and clinical data were abstracted from charts of 5071 patients aged 21 to 84 years, which were seen between June 1, 2001, and May 31, 2003, at 60 practices. Clinical sites were non-university-based primary care practices from 22 North Carolina counties. A dyslipidemia screening test was defined as a lipid profile performed on persons when not on a lipid-lowering drug. Among patients receiving a lipid profile, the proportion of patients appropriately treated, per ATPIII, was calculated. Practice level variation in screening and management was examined using the 50th (20th and 80th) percentile values across practices. RESULTS: The median practice level dyslipidemia screening rate during the 2 years was 40.1% (25.8%, 53.7%) of their age-eligible patients. The appropriate decision regarding lipid-lowering therapy was documented within 4 months of the lipid profile for 79.3% (69.0%, 86.0%) of practices' patients. Within 4 months, among the drug-ineligible patients, 100% (94%, 100%) were not prescribed drugs; 33.3% (6.3%, 50.0%) of the drug-eligible patients were prescribed lipid-lowering agents. CONCLUSIONS: The median dyslipidemia screening rate met the recommendations. There remains a need to improve the management of dyslipidemia; in particular, there was a significant underprescription of lipid-lowering drugs.

Adult↗

The bone marrow-derived endothelial progenitor cell response is impaired in delayed wound healing from ischemia.

OBJECTIVE: Vasculogenesis relies on the recruitment of bone marrow-derived endothelial progenitor cells (BMD EPCs) and is stimulated by tissue-level ischemia. We hypothesized that the BMD EPC response is impaired in ischemic wounds and studied the relationship between BMD EPCs and wound healing. METHODS: We used transgenic Tie-2/LacZ mice, which carry the beta-galactosidase (beta-gal) reporter gene under Tie-2 promoter control. Wild-type mice were lethally irradiated and reconstituted with Tie-2/LacZ bone marrow. Four weeks later, the mice underwent unilateral femoral artery ligation/excision and bilateral wounding of the hindlimbs. Ischemia was confirmed and monitored with laser Doppler imaging. A subset of mice received incisional vs excisional nonischemic bilateral hindlimb wounds, without femoral ligation. Excisional wound closure was measured by using daily digital imaging and software-assisted calculation of surface area. RESULTS: Ischemia resulted in significantly delayed wound healing and differentially affected the number of BMD EPCs recruited to wound granulation tissue and muscle underlying the wounds. At 3 days postwounding, the granulation tissue of the wound base contained significantly fewer numbers of BMD EPCs in ischemic wounds compared with the nonischemic wounds (P < .05). In contrast, significantly more BMD EPCs were present in the muscle underlying the ischemic wounds at this same time point compared with the muscle under the nonischemic wounds (P < .05). In ischemic wounds, eventual wound closure significantly correlated with a delayed rise in BMD EPCs within the wound granulation tissue (Kendall's correlation, -.811, P = .0005) and was significantly associated with a gradual recovery of hindlimb perfusion (P < .0001). By 7 days postwounding, BMD EPCs were incorporated into the neovessels in the granulation tissue. At 14 days and 75 days, BMD EPCs were rarely observed within the wounds. CONCLUSIONS: Granulation tissue of excisional ischemic wounds showed significantly less BMD EPCs 3 days postwounding, in association with significantly delayed wound closure. However, the number of BMD EPCs were increased in ischemic hindlimb skeletal muscle, consistent with the notion that ischemia is a powerful signal for vasculogenesis. To our knowledge, this is the first report identifying a deficit in BMD EPCs in the granulation tissue of ischemic skin wounds and reporting the key role for these cells in both ischemic and nonischemic wound healing.

Animals↗

A diet rich in green and yellow vegetables inhibits atherosclerosis in mice.

Although dietary patterns characterized by a high intake of fruits and vegetables are associated with reduced risk of coronary heart disease, the mechanisms involved are uncertain. We determined the effects of a diet rich in green and yellow vegetables on the development of atherosclerosis, the underlying cause of coronary heart disease, in a mouse model of atherosclerosis, the LDL receptor -/-, apolipoprotein B transgenic mouse. The mice were randomized into 2 diet groups: 1) a vegetable-free control diet (n = 53) and 2) the same diet with 30% (w:w) replaced by an equal-parts mixture of freeze-dried peas, green beans, broccoli, corn, and carrots (n = 54). Mice were fed these diets for 16 wk. Aortic atherosclerosis, as estimated by cholesteryl ester content, was reduced 38% (P < 0.001) in mice fed the vegetable-rich diet. Plasma total cholesterol (-12%), VLDL + ILDL cholesterol (-32%), serum amyloid A (-37%), and body weight (-7%) (all P < 0.01) were also lower in these mice at the end of the treatment period. In a regression model, antiatherogenic effects of the vegetable diet remained largely unexplained by the variation in plasma lipoproteins or body weight. Although the pathway(s) involved remain uncertain, the results indicate that a diet rich in green and yellow vegetables inhibits the development of atherosclerosis and may therefore lead to a reduction in the risk of coronary heart disease.

Animals↗

Unbalanced ranked set sampling for estimating a population proportion.

The application of ranked set sampling (RSS) techniques to data from a dichotomous population is currently an active research topic, and it has been shown that balanced RSS leads to improvement in precision over simple random sampling (SRS) for estimation of a population proportion. Balanced RSS, however, is not in general optimal in terms of variance reduction for this setting. The objective of this article is to investigate the application of unbalanced RSS in estimation of a population proportion under perfect ranking, where the probabilities of success for the order statistics are functions of the underlying population proportion. In particular, the Neyman allocation, which assigns sample units for each order statistic proportionally to its standard deviation, is shown to be optimal in the sense that it leads to minimum variance within the class of RSS estimators that are simple averages of the means of the order statistics. We also use a substantial data set, the National Health and Nutrition Examination Survey III (NHANES III) data, to demonstrate the feasibility and benefits of Neyman allocation in RSS for binary variables.

Data Interpretation, Statistical↗

Ranked set sampling for efficient estimation of a population proportion.

Ranked set sampling (RSS) is a sampling procedure that can be considerably more efficient than simple random sampling (SRS). It involves preliminary ranking of the variable of interest to aid in sample selection. Although ranking processes for continuous variables that are implemented through either subjective judgement or via the use of a concomitant variable have been studied extensively in the literature, the use of RSS in the case of a binary variable has not been investigated thoroughly. In this paper we propose the use of logistic regression to aid in the ranking of a binary variable of interest. We illustrate the application of RSS to estimation of a population proportion with an example based on the National Health and Nutrition Examination Survey III data set. Our results indicate that this use of logistic regression improves the accuracy of the preliminary ranking in RSS and leads to substantial gains in precision for estimation of a population proportion.

Adult↗

Use of complementary and alternative medicine by persons with arthritis: results of the National Health Interview Survey.

OBJECTIVE: To compare the complementary and alternative medicine (CAM) used by adults ages 45 years and older with and without arthritis, and to investigate the prevalence and predictors of CAM use by persons who report being told by a doctor they had arthritis. METHODS: Data from the 2002 National Health Interview Survey with a supplemental section on CAM use were analyzed. Data on overall use and use by 4 CAM modalities were calculated by arthritis status. CAM use for treatment of any health condition, including arthritis, was calculated and compared by arthritis status. Logistic regression was used to identify predictors of CAM use among persons with arthritis. RESULTS: Overall use of CAM and use of 3 of 4 major CAM categories were higher for persons who reported doctor-diagnosed arthritis compared with those without arthritis. Biologically based therapies were the most frequently reported modalities. Although persons with arthritis were more likely than those without arthritis to report using CAM for treatment, most of their CAM use was for conditions other than arthritis. Joint pain and poor functional status were the most common predictors of CAM modalities among persons with arthritis. CONCLUSION: Health care providers of persons with arthritis should be aware that CAM use is common among their patients. A complete medication history is needed to obtain information on CAM use for all conditions.

Aged↗

The cell cycle-regulated genes of Schizosaccharomyces pombe.

Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast) and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast). The 750 genes with the most significant oscillations were identified and analyzed. There were two broad waves of cell cycle transcription, one in early/mid G2 phase, and the other near the G2/M transition. The early/mid G2 wave included many genes involved in ribosome biogenesis, possibly explaining the cell cycle oscillation in protein synthesis in S. pombe. The G2/M wave included at least three distinctly regulated clusters of genes: one large cluster including mitosis, mitotic exit, and cell separation functions, one small cluster dedicated to DNA replication, and another small cluster dedicated to cytokinesis and division. S. pombe cell cycle genes have relatively long, complex promoters containing groups of multiple DNA sequence motifs, often of two, three, or more different kinds. Many of the genes, transcription factors, and regulatory mechanisms are conserved between S. pombe and S. cerevisiae. Finally, we found preliminary evidence for a nearly genome-wide oscillation in gene expression: 2,000 or more genes undergo slight oscillations in expression as a function of the cell cycle, although whether this is adaptive, or incidental to other events in the cell, such as chromatin condensation, we do not know.

Cell Cycle↗

Vascular endothelial growth factor-C promotes vasculogenesis, angiogenesis, and collagen constriction in three-dimensional collagen gels.

OBJECTIVE: Neovascularization, angiogenesis, and collagen constriction are essential for wound healing. We tested whether vascular endothelial growth factor-C (VEGF-C) can promote collagen constriction, capillary sprouting (angiogenesis), and invasion/migration of bone marrow-derived endothelial progenitor cells into collagen (vasculogenesis). METHODS: We used a recently characterized three-dimensional collagen matrix assay with either monolayers of human dermal microvascular endothelial cells (HMVECs) or bone marrow-derived endothelial progenitor cells (BMD EPCs), obtained from Tie-2 LacZ transgenic mice, overlaid with an acellular layer and then a cellular layer of collagen embedded with fibroblasts, that were nontransduced or transduced with either LacZ adenoviral vector (Ad5) or VEGF-C/Ad5. The ability of VEGF-C to enhance fibroblast-mediated collagen constriction was measured, and gels overlying HMVECs or BMD EPCs were co-cultured, harvested, and assayed for HMVEC migration, sprouting, and capillary-like formation; gels containing BMD EPCs were assayed for EPC invasion/migration into the collagen extracellular matrix. RESULTS: VEGF-C significantly increased collagen constriction and formation of capillary-like structures with true lumina (P < .05) assessed by von Willebrand factor and VEGF receptor-2 immunoassaying. VEGF-C induced a significant increase in HMVEC migration, tubular polarization, and branching sprouts associated with a significant up-regulation of membrane type 1 matrix metalloproteinase (MT1-MMP) ( P < .05). Fibroblasts were necessary to support BMD-EPC invasion/migration from the monolayer into the collagen. Moreover, fibroblasts overexpressing VEGF-C significantly enhanced EPC invasion/migration ( P < .05) into the extracellular matrix by two-fold, and this effect could not be achieved with equivalent levels of exogenous VEGF-C in the absence of fibroblasts. The addition of a soluble VEGF-C competitor protein only partially inhibited these responses, reducing the EPCs by three-fold, but significant numbers of EPCs still invaded/migrated into the extracellular matrix, suggesting that other fibroblast-specific signals also contribute to the vasculogenic response. CONCLUSION: Fibroblast-specific expression of VEGF-C promotes collagen constriction by fibroblasts and enhances microvascular endothelial cell migration, branching, and capillary sprouting in association with up-regulating MT1-MMP expression. Fibroblasts are necessary for BMD EPC invasion/migration into collagen, and their overexpression of VEGF-C enhances this fibroblast-mediated vasculogenic effect. Collectively, these findings suggest a role for VEGF-C in multiple biologic steps required for wound healing (angiogenesis, vasculogenesis, and collagen constriction). CLINICAL RELEVANCE: Ischemic wound healing remains an unsolved problem with no previously identified molecular target for therapeutic intervention. This study demonstrates that VEGF-C overexpression by fibroblasts stimulates multiple biologic processes known to impact wound healing, such as collagen constriction, capillary sprouting, and EPC invasion and migration through extracellular matrix. Most ischemic wounds fail to heal and frequently lead to major limb amputation. Available cytokine ointments are ineffective, and revascularization is often not technically feasible. Even when these procedures are accomplished, many ischemic wounds frequently still do not heal because of multifactorial tissue level impairments in the fibroblastic and neovascularization responses at the wound base. Our findings identify an important role for two novel tissue level targets, dermis-derived fibroblasts and VEGF-C, in collagen constriction, angiogenesis, and postnatal vasculogenesis from BMD EPCs. Thus the findings are particularly relevant to the unsolved clinical problem of ischemic wound healing.

Animals↗

Normal human fibroblasts enable melanoma cells to induce angiogenesis in type I collagen.

BACKGROUND: We previously reported that fibroblasts induce human microvascular endothelial cells (HMVECs) to differentiate from monolayer to capillarylike morphology. We now test the hypothesis that fibroblasts modulate angiogenesis in melanoma cells. METHODS: We tested 12 human melanoma lines (2 radial growth phase (RGP), 3 vertical growth phase (VGP), and 7 metastatic (MM)) for ability to induce HMVECs to invade/migrate into collagen and form capillarylike networks. HMVEC monolayers were overlaid with 3-dimensional collagen gels embedded with melanoma cells alone (M), fibroblasts alone (F), or a 1:1 mixture of the 2 cells (M+F). After 5 days, gels were removed, fixed, and HMVEC networks were quantified by von Willebrand's factor (vWF) immunofluorescence. The influence of soluble factors on HMVEC invasion/migration into collagen was assessed with the use of acellular 3-D collagen gels overlaid on HMVEC monolayers, cultured with conditioned media (CM) derived from monolayers of M, F, or M+F. Angiogenic growth factors involved in the observed invasion/migration were identified with the use of a RayBio Cytokine Antibody Array (RayBiotech, Norcross, Ga). RESULTS: Cell line-specific variability in melanoma-supported angiogenesis was observed only when in combination with fibroblasts (analysis of variance [ANOVA], P < .01). Melanoma plus fibroblasts uniformly resulted in a significantly higher angiogenic response than melanoma alone (P < .05). One vertical growth phase and one metastatic melanoma line, while weakly angiogenic alone, induced significantly higher angiogenesis than either fibroblast or melanoma alone (P < .05) when combined with fibroblasts. CM from M or M+F induced significantly less HMVEC invasion/migration into collagen than CM from fibroblasts alone. Interleukin 8, monocyte chemotactic protein-1, and tissue inhibitor of metalloproteinase-2 were identified as significantly elevated in the media derived from M+F cultures, compared with either cell type alone. CONCLUSION: To our knowledge, this is the first report demonstrating that melanoma-supported angiogenesis in collagen is more significantly influenced by normal skin-derived fibroblasts than by the intrinsic biology of the melanoma cell type. Interleukin 8, monocyte chemotactic protein-1, and tissue inhibitor of metalloproteinase-2 are implicated as potential paracrine factors regulating this observed effect.

Angiogenic Proteins↗

Resistance to anti-CD45RB-induced tolerance in NOD mice: mechanisms involved.

While great advances have been made in the success of islet transplantation to cure autoimmune diabetes, this protocol remains limited by our inability to induce donor-specific tolerance within the recipient. The profound resistance of the NOD mouse to tolerance-inducing regimens that are routinely successful in other strains further defines the imposing barriers that must be surmounted. Herein, we have assessed the utility of anti-CD45RB therapy to induce tolerance to allografts in C57BL/6 and NOD-strain mice. We find that, as with other therapies, NOD mice are also resistant to this manipulation, despite robust tolerance induction in the comparison strain. Analysis of cell surface markers revealed a number of changes within the B lymphocyte compartment following contact with antibody and alloantigen in the B6 strain. The absence of reciprocal changes within the NOD lymphocyte compartment suggests that B cells might contribute to the mechanism of action of this therapy and to the resistance to immunological tolerance noted in the NOD strain.

Animals↗

Synthesis and evaluation of indenopyrazoles as cyclin-dependent kinase inhibitors. Part 4: Heterocycles at C3.

New indeno[1,2-c]pyrazol-4-one cyclin dependent kinase inhibitors have been disclosed. The most promising compounds are nanomolar enzyme inhibitors with excellent activity against tumor cells. The most advanced compound retains cell culture activity even in the presence of human serum proteins. The most advanced compound did not kill the normal fibroblast line AG1523.

Cell Line, Tumor↗

Discovery of 1-(2-aminomethylphenyl)-3-trifluoromethyl-N- [3-fluoro-2'-(aminosulfonyl)[1,1'-biphenyl)]-4-yl]-1H-pyrazole-5-carboxyamide (DPC602), a potent, selective, and orally bioavailable factor Xa inhibitor(1).

Factor Xa, a serine protease, is at the critical juncture between the intrinsic and extrinsic pathways of the coagulation cascade. Inhibition of factor Xa has the potential to provide effective treatment for both venous and arterial thrombosis. We recently described a series of meta-substituted phenylpyrazoles that are highly potent, selective, and orally bioavailable factor Xa inhibitors. In this paper we report our efforts to further optimize the selectivity profile of our factor Xa inhibitors with a series of ortho- and/or para-substituted phenylpyrazole derivatives. The most potent compounds display sub-nanomolar inhibition constants for factor Xa and show greater than 1000-fold selectivity against other serine proteases. These compounds are also effective in a rabbit model of arteriovenous shunt thrombosis. Optimization of this series led to the preclinical development of DPC602, a 2-(aminomethyl)phenylpyrazole analogue, as a highly potent, selective, and orally bioavailable factor Xa inhibitor.

Administration, Oral↗

Synthesis and evaluation of indenopyrazoles as cyclin-dependent kinase inhibitors. 3. Structure activity relationships at C3(1,2).

The identification of indeno[1,2-c]pyrazol-4-ones as inhibitors of cyclin-dependent kinases (CDKs) has led to the discovery of a series of novel and potent compounds. Herein, we report the effects of substitutions at C3 of the indeno[1,2-c]pyrazol-4-one core with alkyls, heterocycles, and substituted phenyls. Substitutions at the para position of the phenyl ring at C3 were generally well-tolerated; however, larger groups were generally inactive. For alkyls directly attached to C3, longer chain substituents were not tolerated; however, shorter alkyl groups and cyclic alkyls were acceptable. In general, the heterocycles at C3 gave the most potent analogues. One such heterocycle, 24j, was examined in detail and was determined to have a biological profile consistent with CDK inhibition. An X-ray crystal structure of one of the alkyl compounds, 13q, complexed with CDK2 was determined and showed the inhibitor residing in the adenosine 5'-triphosphate pocket of the enzyme.

Antineoplastic Agents↗