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1.
Front Plant Sci ; 13: 816438, 2022.
Article in English | MEDLINE | ID: mdl-35300013

ABSTRACT

Bioeffector (BE) application is emerging as a strategy for achieving sustainable agricultural practices worldwide. However, the effect of BE on crop growth and quality is still controversial and there is still no adequate impact assessment that determines factors on the efficiency of BE application. Therefore, we carried out a network metaanalysis on the effect of BEs using 1,791 global observations from 186 studies to summarize influencing factors and the impact of BEs on crop growth, quality, and nutrient contents. The results show that BEs did not only improve plant growth by around 25% and yield by 30%, but also enhanced crop quality, e.g., protein (55% increase) and soluble solids content (75% increase) as well as aboveground nitrogen (N) and phosphate (P) content by 28 and 40%, respectively. The comparisons among BE types demonstrated that especially non-microbial products, such as extracts and humic/amino acids, have the potential to increase biomass growth by 40-60% and aboveground P content by 54-110%. The soil pH strongly influenced the efficiency of the applied BE with the highest effects in acidic soils. Our results showed that BEs are most suitable for promoting the quality of legumes and increasing the yield of fruits, herbs, and legumes. We illustrate that it is crucial to optimize the application of BEs with respect to the right application time and technique (e.g., placement, foliar). Our results provide an important basis for future research on the mechanisms underlying crop improvement by the application of BEs and on the development of new BE products.

2.
Clin Cancer Res ; 26(3): 643-656, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31582516

ABSTRACT

PURPOSE: TGFßs are overexpressed in many advanced cancers and promote cancer progression through mechanisms that include suppression of immunosurveillance. Multiple strategies to antagonize the TGFß pathway are in early-phase oncology trials. However, TGFßs also have tumor-suppressive activities early in tumorigenesis, and the extent to which these might be retained in advanced disease has not been fully explored. EXPERIMENTAL DESIGN: A panel of 12 immunocompetent mouse allograft models of metastatic breast cancer was tested for the effect of neutralizing anti-TGFß antibodies on lung metastatic burden. Extensive correlative biology analyses were performed to assess potential predictive biomarkers and probe underlying mechanisms. RESULTS: Heterogeneous responses to anti-TGFß treatment were observed, with 5 of 12 models (42%) showing suppression of metastasis, 4 of 12 (33%) showing no response, and 3 of 12 (25%) showing an undesirable stimulation (up to 9-fold) of metastasis. Inhibition of metastasis was immune-dependent, whereas stimulation of metastasis was immune-independent and targeted the tumor cell compartment, potentially affecting the cancer stem cell. Thus, the integrated outcome of TGFß antagonism depends on a complex balance between enhancing effective antitumor immunity and disrupting persistent tumor-suppressive effects of TGFß on the tumor cell. Applying transcriptomic signatures derived from treatment-naïve mouse primary tumors to human breast cancer datasets suggested that patients with breast cancer with high-grade, estrogen receptor-negative disease are most likely to benefit from anti-TGFß therapy. CONCLUSIONS: Contrary to dogma, tumor-suppressive responses to TGFß are retained in some advanced metastatic tumors. Safe deployment of TGFß antagonists in the clinic will require good predictive biomarkers.


Subject(s)
Antineoplastic Agents, Immunological/pharmacology , Breast Neoplasms/drug therapy , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , Lung Neoplasms/drug therapy , Neoplastic Stem Cells/drug effects , Transforming Growth Factor beta/antagonists & inhibitors , Animals , Breast Neoplasms/immunology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Disease Models, Animal , Female , Humans , Lung Neoplasms/immunology , Lung Neoplasms/metabolism , Lung Neoplasms/secondary , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Neoplastic Stem Cells/metabolism , Signal Transduction , Transforming Growth Factor beta/immunology , Transforming Growth Factor beta/metabolism , Treatment Outcome
3.
Oncotarget ; 7(25): 38164-38179, 2016 Jun 21.
Article in English | MEDLINE | ID: mdl-27203217

ABSTRACT

Transforming growth factor-ßs (TGF-ßs) regulate tissue homeostasis, and their expression is perturbed in many diseases. The three isoforms (TGF-ß1, -ß2, and -ß3) have similar bioactivities in vitro but show distinct activities in vivo. Little quantitative information exists for expression of TGF-ß isoform proteins in physiology or disease. We developed an optimized method to quantitate protein levels of the three isoforms, using a Luminex® xMAP®-based multianalyte assay following acid-ethanol extraction of tissues. Analysis of multiple tissues and plasma from four strains of adult mice showed that TGF-ß1 is the predominant isoform with TGF-ß2 being ~10-fold lower. There were no sex-specific differences in isoform expression, but some tissues showed inter-strain variation, particularly for TGF-ß2. The only adult tissue expressing appreciable TGF-ß3 was the mammary gland, where its levels were comparable to TGF-ß1. In situ hybridization showed the luminal epithelium as the major source of all TGF-ß isoforms in the normal mammary gland. TGF-ß1 protein was 3-8-fold higher in three murine mammary tumor models than in normal mammary gland, while TGF-ß3 protein was 2-3-fold lower in tumors than normal tissue, suggesting reciprocal regulation of these isoforms in mammary tumorigenesis.


Subject(s)
Mammary Neoplasms, Experimental/immunology , Transforming Growth Factor beta1/metabolism , Transforming Growth Factor beta3/metabolism , Transforming Growth Factor beta/metabolism , Animals , Female , Humans , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Inbred BALB C , Protein Isoforms
4.
Mol Carcinog ; 55(12): 2183-2195, 2016 12.
Article in English | MEDLINE | ID: mdl-26859836

ABSTRACT

Bryostatin 1, a complex macrocyclic lactone, is the subject of multiple clinical trials for cancer chemotherapy. Although bryostatin 1 biochemically functions like the classic mouse skin tumor promoter phorbol 12-myristate 13-acetate (PMA) to bind to and activate protein kinase C, paradoxically, it fails to induce many of the typical phorbol ester responses, including tumor promotion. Intense synthetic efforts are currently underway to develop simplified bryostatin analogs that preserve the critical functional features of bryostatin 1, including its lack of tumor promoting activity. The degree to which bryostatin analogs maintain the unique pattern of biological behavior of bryostatin 1 depends on the specific cellular system and the specific response. Merle 23 is a significantly simplified bryostatin analog that retains bryostatin like activity only to a limited extent. Here, we show that in mouse epidermal cells the activity of Merle 23 was either similar to bryostatin 1 or intermediate between bryostatin 1 and PMA, depending on the specific parameter examined. We then examined the hyperplastic and tumor promoting activity of Merle 23 on mouse skin. Merle 23 showed substantially reduced hyperplasia and was not tumor promoting at a dose comparable to that for PMA. These results suggest that there may be substantial flexibility in the design of bryostatin analogs that retain its lack of tumor promoting activity. © 2016 Wiley Periodicals, Inc.


Subject(s)
Antineoplastic Agents/pharmacology , Bryostatins/pharmacology , Keratinocytes/drug effects , Skin Neoplasms/chemically induced , Skin Neoplasms/drug therapy , Animals , Drug Design , Epidermis/drug effects , Epidermis/metabolism , Epidermis/pathology , Female , Keratinocytes/metabolism , Keratinocytes/pathology , Mice, Inbred BALB C , Mice, Inbred SENCAR , Phorbol Esters/pharmacology , Protein Kinase C/metabolism , Skin Neoplasms/metabolism , Skin Neoplasms/pathology
5.
Mol Biol Cell ; 27(8): 1346-57, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-26864624

ABSTRACT

The coordination of cell cycle progression with the repair of DNA damage supports the genomic integrity of dividing cells. The function of many factors involved in DNA damage response (DDR) and the cell cycle depends on their Ran GTPase-regulated nuclear-cytoplasmic transport (NCT). The loading of Ran with GTP, which is mediated by RCC1, the guanine nucleotide exchange factor for Ran, is critical for NCT activity. However, the role of RCC1 or Ran⋅GTP in promoting cell proliferation or DDR is not clear. We show that RCC1 overexpression in normal cells increased cellular Ran⋅GTP levels and accelerated the cell cycle and DNA damage repair. As a result, normal cells overexpressing RCC1 evaded DNA damage-induced cell cycle arrest and senescence, mimicking colorectal carcinoma cells with high endogenous RCC1 levels. The RCC1-induced inhibition of senescence required Ran and exportin 1 and involved the activation of importin ß-dependent nuclear import of 53BP1, a large NCT cargo. Our results indicate that changes in the activity of the Ran⋅GTP-regulated NCT modulate the rate of the cell cycle and the efficiency of DNA repair. Through the essential role of RCC1 in regulation of cellular Ran⋅GTP levels and NCT, RCC1 expression enables the proliferation of cells that sustain DNA damage.


Subject(s)
Cell Cycle Proteins/metabolism , Cell Cycle/physiology , DNA Repair/physiology , Guanine Nucleotide Exchange Factors/metabolism , Nuclear Proteins/metabolism , ran GTP-Binding Protein/metabolism , Cell Cycle Proteins/genetics , Cellular Senescence/physiology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , DNA Damage/physiology , Doxorubicin/pharmacology , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation , Guanine Nucleotide Exchange Factors/genetics , Guanosine Triphosphate/metabolism , HCT116 Cells/drug effects , HeLa Cells , Humans , Karyopherins/metabolism , Nuclear Proteins/genetics , RNA Interference , Receptors, Cytoplasmic and Nuclear/metabolism , beta Karyopherins/metabolism , ran GTP-Binding Protein/genetics , Exportin 1 Protein
6.
Cancer ; 122(4): 588-597, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26566079

ABSTRACT

BACKGROUND: Inhibitors of apoptosis proteins (IAPs) are key regulators of apoptosis and are frequently dysregulated in ovarian cancer. It was hypothesized that blocking IAPs with birinapant would increase tumor cell death and result in objective responses for women with platinum-refractory and -resistant ovarian cancer. METHODS: In this phase 2, Cancer Therapy Evaluation Program-sponsored study, patients received birinapant at 47 mg/m(2) on days 1, 8, and 15 of 28-day cycles. Pharmacokinetics were obtained during cycle 1. Plasma, peripheral blood mononuclear cells (PBMCs), and percutaneous tumor biopsy samples were collected before cycle 1 and after 6 weeks. The primary endpoint was an objective response or progression-free survival lasting greater than 6 months in a mini-max design. RESULTS: Eleven patients received birinapant; after this, accrual was terminated for lack of a clinical benefit. Birinapant was well tolerated, with predominantly grade 2 adverse events and 1 case of grade 3 lymphopenia. Pretreatment biopsy samples and PBMCs were collected; paired posttreatment biopsy samples and PBMCs were collected from 7 and 10 patients, respectively. There was consistent downregulation of cellular inhibitor of apoptosis protein 1 in tumors (P = .016) and PBMCs (P < .01). Procaspase 3 also decreased in tumors (P = .031) and PBMCs (P < .01); cleaved caspase 3 colocalized with H2A histone family member X (γ-H2AX) in tumors after birinapant exposure. Peripheral T and B cells decreased significantly after treatment, but natural killer cells did not (P = .04, P = .05, and P = .43, respectively). CONCLUSIONS: Birinapant shows consistent target suppression in vivo without single-agent antitumor activity in this small population. Single-agent pharmacodynamics are necessary to understand the drug's mechanism of action and set the stage for rational combination therapy. Preclinical studies are ongoing to identify optimal synergistic combinations for future clinical trials.


Subject(s)
Adenocarcinoma, Clear Cell/drug therapy , Antineoplastic Agents/therapeutic use , Carcinoma, Endometrioid/drug therapy , Dipeptides/therapeutic use , Drug Resistance, Neoplasm , Indoles/therapeutic use , Neoplasms, Cystic, Mucinous, and Serous/drug therapy , Neoplasms, Glandular and Epithelial/drug therapy , Ovarian Neoplasms/drug therapy , Adenocarcinoma, Clear Cell/metabolism , Aged , Antineoplastic Agents/pharmacokinetics , Apoptosis Regulatory Proteins , B-Lymphocytes , Carcinoma, Endometrioid/metabolism , Carcinoma, Ovarian Epithelial , Caspase 3/metabolism , Dipeptides/pharmacokinetics , Disease-Free Survival , Female , Humans , Indoles/pharmacokinetics , Inhibitor of Apoptosis Proteins/metabolism , Intracellular Signaling Peptides and Proteins , Killer Cells, Natural , Leukocytes, Mononuclear/metabolism , Lymphocyte Count , Lymphopenia/chemically induced , Middle Aged , Mitochondrial Proteins , Neoplasms, Cystic, Mucinous, and Serous/metabolism , Neoplasms, Glandular and Epithelial/metabolism , Ovarian Neoplasms/metabolism , Platinum Compounds/therapeutic use , T-Lymphocytes , Treatment Failure , Treatment Outcome , Ubiquitin-Protein Ligases/metabolism
7.
Clin Cancer Res ; 22(5): 1067-75, 2016 Mar 01.
Article in English | MEDLINE | ID: mdl-26446942

ABSTRACT

PURPOSE: AZD6244 is a MEK1/2 inhibitor with significant preclinical activity in multiple myeloma cells. This phase II study used a two-stage Simon design to determine the AZD6244 response rate in patients with relapsed or refractory multiple myeloma. EXPERIMENTAL DESIGN: AZD6244 (75 mg) was administered orally, twice a day, continuously for 28-day cycles. Response was evaluated after three cycles. RESULTS: Thirty-six patients received therapy. The median age was 65 years (range: 43-81) and the median number of prior therapies was 5 (range: 2-11). The most common grade 3 and 4 toxicities included anemia, neutropenia, thrombocytopenia, diarrhea, and fatigue. Three deaths occurred possibly related to AZD6244 (2 due to sepsis, 1 due to acute kidney injury). After AZD6244 discontinuation, three additional deaths occurred due to disease progression. The response rate (CR + PR) was 5.6% with a mean duration of response of 4.95 months and median progression-free survival time of 3.52 months. One patient had a very good partial response (VGPR), 1 patient had a partial response, 17 patients had stable disease, 13 patients had progressive disease, and 4 patients could not be assessed for response. Pharmacodynamic studies revealed variable effects on bone marrow CD138(+) cell MEK1/2 and ERK1/2 phosphorylation. The best clinical response, a prolonged VGPR, occurred in a patient with an MMSET translocation. CONCLUSIONS: Single-agent AZD6244 was tolerable and had minimal activity in this heavily pretreated population.


Subject(s)
Benzimidazoles/administration & dosage , Multiple Myeloma/drug therapy , Neoplasm Recurrence, Local/drug therapy , Adult , Aged , Aged, 80 and over , Benzimidazoles/adverse effects , Benzimidazoles/pharmacokinetics , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , MAP Kinase Kinase Kinases/antagonists & inhibitors , MAP Kinase Kinase Kinases/genetics , Male , Middle Aged , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Neoplasm Recurrence, Local/pathology , Proto-Oncogene Proteins p21(ras)/genetics
8.
J Med Chem ; 57(12): 5356-69, 2014 Jun 26.
Article in English | MEDLINE | ID: mdl-24906106

ABSTRACT

Protein kinase C (PKC), a validated therapeutic target for cancer chemotherapy, provides a paradigm for assessing structure-activity relations, where ligand binding has multiple consequences for a target. For PKC, ligand binding controls not only PKC activation and multiple phosphorylations but also subcellular localization, affecting subsequent signaling. Using a capillary isoelectric focusing immunoassay system, we could visualize a high resolution isoelectric focusing signature of PKCδ upon stimulation by ligands of the phorbol ester and bryostatin classes. Derivatives that possessed different physicochemical characteristics and induced different patterns of biological response generated different signatures. Consistent with different patterns of PKCδ localization as one factor linked to these different signatures, we found different signatures for activated PKCδ from the nuclear and non-nuclear fractions. We conclude that the capillary isoelectric focusing immunoassay system may provide a window into the integrated consequences of ligand binding and thus afford a powerful platform for compound development.


Subject(s)
Bryostatins/metabolism , Isoelectric Focusing , Phorbol Esters/metabolism , Protein Kinase C-delta/metabolism , Cell Line, Tumor , Humans , Immunoassay/methods , Ligands , Phosphorylation , Protein Binding , Structure-Activity Relationship
9.
Mol Cancer Ther ; 12(11): 2601-13, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23979919

ABSTRACT

Developing proteomic biomarkers is valuable for evaluating therapeutic effects of drugs and generating better treatment strategies. However, conventional protein analysis is often challenging due to inadequate sample size of clinical specimens, lack of assay reproducibility, accuracy, and sensitivity. A novel capillary isoelectricfocusing (IEF) immunoassay system (NanoPro) was used to study the dynamic phosphorylation status of signaling molecules in non-small cell lung cancer (NSCLC) cells treated with EGFR tyrosine kinase and MEK inhibitors. NanoPro showed the same dynamic ERK phosphorylation as Western blotting with good assay reproducibility using 1,000 times less protein. The IEF separation in NanoPro system enables multiple protein phosphorylation isoforms to be resolved and detected simultaneously. With NanoPro, we identified a specific on-target mitogen-activated protein/extracellular signal-regulated kinase (MEK) response pattern to MEK inhibitor PD325901, which was not detectable by Western blot analysis. We also revealed a MEK2 signal that may be associated with NSCLC cell sensitivity to the EGF receptor inhibitor erlotinib, and distinguished erlotinib-sensitive cells from intrinsic as well as acquired resistant cells to erlotinib. Moreover, NanoPro could differentiate human ERK1 isoforms from the mouse isoforms based on their isoelectric point differences and showed that erlotinib effectively inhibited ERK phosphorylation in targeted human xenograft cancer cells but not in surrounding mouse stromal cells. With 8 µg of tumor aspirates, we precisely quantified the response of 18 signaling molecules to erlotinib and MEK1 inhibitor treatments in an NSCLC patient. NanoPro's higher sensitivity, better resolution of protein phosphorylation status, and reduced tissue requirement warrant NanoPro's investigation for future drug development and evaluation of drug effects of targeted therapies.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/metabolism , Immunoassay/methods , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Protein Kinase Inhibitors/therapeutic use , Quinazolines/therapeutic use , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Benzimidazoles/therapeutic use , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Erlotinib Hydrochloride , Extracellular Signal-Regulated MAP Kinases/metabolism , Humans , Lung Neoplasms/pathology , Lymphatic Metastasis , MAP Kinase Kinase 2/antagonists & inhibitors , MAP Kinase Kinase 2/metabolism , MAP Kinase Signaling System/drug effects , Mice , Mice, Nude , Molecular Targeted Therapy , Neoplasms, Experimental , Oncogene Proteins/genetics , Oncogene Proteins/metabolism , Phosphorylation , Protein Kinase Inhibitors/pharmacokinetics , Quinazolines/pharmacokinetics
10.
Anal Biochem ; 442(1): 97-103, 2013 Nov 01.
Article in English | MEDLINE | ID: mdl-23896461

ABSTRACT

Precise and accurate quantification of protein expression levels in a complex biological setting is challenging. Here, we describe a method for absolute quantitation of endogenous proteins in cell lysates using an automated capillary immunoassay system, the size-based Simple Western system (recently developed by ProteinSimple). The method was able to accurately measure the absolute amounts of target proteins at picogram or sub-picogram levels per nanogram of cell lysates. The measurements were independent of the cell matrix or the cell lysis buffer and were not affected by different antibody affinities for their specific epitopes. We then applied this method to quantitate absolute levels of expression of protein kinase C (PKC) isoforms in LNCaP and U937 cells, two cell lines used extensively for probing the downstream biological responses to PKC targeted ligands. Our absolute quantitation confirmed the predominance of PKCδ in both cells, supporting the important functional role of this PKC isoform in these cell lines. The method described here provides an approach to accurately quantitate levels of protein expression and correlate protein level with function. In addition to enhanced accuracy relative to conventional Western analysis, it circumvents the distortions inherent in comparison with signal intensities from different antibodies with different affinities.


Subject(s)
Immunoassay/methods , Protein Kinase C/analysis , Automation , Blotting, Western , Cell Line, Tumor , Humans , Isoenzymes/analysis , Isoenzymes/metabolism , Protein Kinase C/metabolism , Recombinant Proteins/analysis , Recombinant Proteins/metabolism
11.
Drug Metab Dispos ; 41(10): 1805-12, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23868912

ABSTRACT

ABCG2 (also known as breast cancer resistance protein) is an ATP-binding cassette (ABC) transporter localized to the plasma membrane where it mediates the efflux of xenobiotics, including potential therapeutics. Studies investigating Abcg2 function at the blood-brain barrier in mouse models are often compared with human ABCG2 function. It is critical to understand the nature of species differences between mouse and human ABCG2, since extrapolations are made from murine data to humans. Two independent drug-selected cell line pairs expressing human or mouse ABCG2 were compared for efflux of fluorescent substrates using flow cytometry. To this end, we developed and characterized a new mouse Abcg2-expressing subline that demonstrated efflux of known fluorescent ABCG2 substrates and increased resistance to mitoxantrone, which is reduced in the presence of the ABCG2 inhibitor Ko143. Our results indicate that the substrate specificity of human and mouse ABCG2 is very similar. We identified a new human and mouse ABCG2 substrate, a porphyrin analog, purpurin-18 (Pp-18), which is not a substrate for P-glycoprotein or multidrug resistance protein 1. The ability of inhibitors to block efflux activity of ABCG2 was assessed using Pp-18. Inhibitors also demonstrated similar effects on human and mouse ABCG2. Chrysin, benzoflavone, and cyclosporin A inhibited Pp-18 efflux in both human and mouse ABCG2. The similarity of the substrate and inhibitor specificity of human and mouse ABCG2 supports interpretation of mouse models in understanding the clinical, pharmacological, and physiologic roles of ABCG2.


Subject(s)
ATP-Binding Cassette Transporters/antagonists & inhibitors , Neoplasm Proteins/antagonists & inhibitors , Substrate Specificity/physiology , 3T3 Cells , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , ATP Binding Cassette Transporter, Subfamily G, Member 2 , ATP-Binding Cassette Transporters/metabolism , Animals , Cell Line , Cell Line, Tumor , Drug Resistance, Multiple/physiology , Drug Resistance, Neoplasm/physiology , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , MCF-7 Cells , Mice , Mitoxantrone/pharmacology , Neoplasm Proteins/metabolism , Porphyrins/pharmacology
12.
ACS Chem Biol ; 8(4): 767-77, 2013 Apr 19.
Article in English | MEDLINE | ID: mdl-23369356

ABSTRACT

The bryostatins are a group of 20 macrolides isolated by Pettit and co-workers from the marine organism Bugula neritina. Bryostatin 1, the flagship member of the family, has been the subject of intense chemical and biological investigations due to its remarkably diverse biological activities, including promising indications as therapy for cancer, Alzheimer's disease, and HIV. Other bryostatins, however, have attracted far less attention, most probably due to their relatively low natural abundance and associated scarcity of supply. Among all macrolides in this family, bryostatin 7 is biologically the most potent protein kinase C (PKC) ligand (in terms of binding affinity) and also the first bryostatin to be synthesized in the laboratory. Nonetheless, almost no biological studies have been carried out on this agent. We describe herein the total synthesis of bryostatin 7 based on our pyran annulation technology, which allows for the first detailed biological characterizations of bryostatin 7 with side-by-side comparisons to bryostatin 1. The results suggest that the more easily synthesized and less lipophilic bryostatin 7 may be an effective surrogate for bryostatin 1.


Subject(s)
Bryostatins/pharmacology , Lipids/chemistry , Bryostatins/chemical synthesis , Bryostatins/chemistry , Cell Line, Tumor , Down-Regulation , Humans , Isoenzymes/metabolism , Male , Membrane Potential, Mitochondrial/drug effects , Protein Kinase C/metabolism , Real-Time Polymerase Chain Reaction , Subcellular Fractions/enzymology , U937 Cells
13.
Gut ; 62(12): 1777-86, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23411027

ABSTRACT

OBJECTIVE: The standard therapy for advanced hepatocellular carcinoma (HCC) is sorafenib, with most patients experiencing disease progression within 6 months. Label-retaining cancer cells (LRCC) represent a novel subpopulation of cancer stem cells (CSC). The objective was to test whether LRCC are resistant to sorafenib. METHODS: We tested human HCC derived LRCC and non-LRCC before and after treatment with sorafenib. RESULTS: LRCC derived from human HCC are relatively resistant to sorafenib. The proportion of LRCC in HCC cell lines is increased after sorafenib while the general population of cancer cells undergoes growth suppression. We show that LRCC demonstrate improved viability and toxicity profiles, and reduced apoptosis, over non-LRCC. We show that after treatment with sorafenib, LRCC upregulate the CSC marker aldehyde dehydrogenase 1 family, wingless-type MMTV-integration-site family, cell survival and proliferation genes, and downregulate apoptosis, cell cycle arrest, cell adhesion and stem cells differentiation genes. This phenomenon was accompanied by non-uniform activation of specific isoforms of the sorafenib target proteins extracellular-signal-regulated kinases and v-akt-murine-thymoma-viral-oncogene homologue (AKT) in LRCC but not in non-LRCC. A molecular pathway map for sorafenib treated LRCC is proposed. CONCLUSIONS: Our results suggest that HCC derived LRCC are relatively resistant to sorafenib. Since LRCC can generate tumours with as few as 10 cells, our data suggest a potential role for these cells in disease recurrence. Further investigation of this phenomenon might provide novel insights into cancer biology, cancer recurrence and drug resistance with important implications for the development of novel cancer therapies based on targeting LRCC.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Niacinamide/analogs & derivatives , Phenylurea Compounds/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor/cytology , Cell Line, Tumor/drug effects , Drug Resistance, Neoplasm , Extracellular Signal-Regulated MAP Kinases/metabolism , Gene Expression Profiling , Humans , Niacinamide/therapeutic use , Oncogene Protein v-akt/metabolism , Real-Time Polymerase Chain Reaction , Sorafenib , Stem Cells/drug effects
14.
Mol Cancer Res ; 10(10): 1389-99, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22878587

ABSTRACT

TGF-ß plays a dual role in epithelial carcinogenesis with the potential to either suppress or promote tumor progression. We found that levels of Smad3 mRNA, a critical mediator of TGF-ß signaling, are reduced by approximately 60% in human breast cancer. We therefore used conditionally immortalized mammary epithelial cells (IMEC) of differing Smad3 genotypes to quantitatively address the Smad3 requirement for different biologic responses to TGF-ß. We found that a two-fold reduction in Smad3 gene dosage led to complex effects on TGF-ß responses; the growth-inhibitory response was retained, the pro-apoptotic response was lost, the migratory response was reduced, and the invasion response was enhanced. Loss of the pro-apoptotic response in the Smad3(+/-) IMECs correlated with loss of Smad3 binding to the Bcl-2 locus, whereas retention of the growth-inhibitory response in Smad3 IMECs correlated with retention of Smad3 binding to the c-Myc locus. Addressing the integrated outcome of these changes in vivo, we showed that reduced Smad3 levels enhanced metastasis in two independent models of metastatic breast cancer. Our results suggest that different biologic responses to TGF-ß in the mammary epithelium are differentially affected by Smad3 dosage and that a mere two-fold reduction in Smad3 is sufficient to promote metastasis.


Subject(s)
Breast Neoplasms/pathology , Epithelium/metabolism , Gene Dosage/drug effects , Mammary Glands, Animal/metabolism , Mammary Glands, Human/metabolism , Smad3 Protein/genetics , Transforming Growth Factor beta/pharmacology , Animals , Breast Neoplasms/genetics , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/pathology , Disease Progression , Enhancer Elements, Genetic/genetics , Epithelium/drug effects , Epithelium/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Mammary Glands, Animal/drug effects , Mammary Glands, Animal/pathology , Mammary Glands, Human/drug effects , Mammary Glands, Human/pathology , Mice , Neoplasm Metastasis , Protein Binding/drug effects , Protein Binding/genetics , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Smad3 Protein/metabolism
15.
Bioorg Med Chem Lett ; 20(23): 7142-6, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-20932750

ABSTRACT

Based upon a previously reported lead compound 1, a series of 1,2-diamino-ethane-substituted-6,7,8,9-tetrahydro-5H-pyrimido[4,5-d]azepines were synthesized and evaluated for improved physiochemical and pharmacokinetic properties while maintaining TRPV1 antagonist activity. Structure-activity relationship studies directed toward improving the aqueous solubility (pH 2 and fasted-state simulated intestinal fluid (SIF)) and rat pharmacokinetics led to the discovery of compound 13. Aqueous solubility of compound 13 (pH 2 ≥237 µg/mL and SIF=11 µg/mL) was significantly improved over compound 1 (pH 2=5 µg/mL and SIF=0.5 µg/mL). In addition, compound 13 afforded improved rat pharmacokinetics (CL=0.7 L/kg/h) compared to compound 1 (CL=3.1 L/kg/h). Compound 13 was orally bioavailable and afforded a significant reversal of carrageenan-induced thermal hyperalgesia at 5 and 30 mg/kg in rats.


Subject(s)
Azepines/chemical synthesis , Azepines/pharmacology , TRPV Cation Channels/antagonists & inhibitors , Animals , Azepines/chemistry , Azepines/pharmacokinetics , Dose-Response Relationship, Drug , Humans , Hydrogen-Ion Concentration , Hyperalgesia/drug therapy , Hyperalgesia/prevention & control , Rats , Solubility , Structure-Activity Relationship
16.
J Bras Nefrol ; 32(1): 49-54, 2010 Mar.
Article in English, Portuguese | MEDLINE | ID: mdl-21448520

ABSTRACT

INTRODUCTION: The incidence and prevalence of treated end-stage chronic kidney disease (CKD) patients continue to grow throughout the world. Renal transplantation remains the preferred form of renal substitutive therapy, but given the limited number of donors, dialytic therapies are the most common modalities. OBJECTIVES: To assess a registry of patients admitted for renal substitutive therapy at a single centre from 1984 to 2009. METHODS: This is a retrospective epidemiological study. The following were analyzed: demographic and clinical characteristics; incidence of CKD; underlying kidney disease; dialysis modalities; mortality; and causes of death. The variables were compared by using the chi-square test, Student t test, ANOVA, and Tukey test. Kaplan-Meier curves were used to estimate patient's survival. A p value < 0.05 was considered statistically significant. RESULTS: In the period studied, 878 patients were admitted to dialysis. Their mean age was 47.0 ± 16.2 years, 549 (62.5%) were males, and 712 (81.1%) were white. The major cause of CKD was hypertension in 351 (40.0%) patients, diabetic nephropathy in 174 (19.8%), and chronic glomerulonephritis in 180 (20.5%) patients. The main dialytic modality was hemodialysis. The one-year mortality rate was 10.4%. The most common cause of death was cardiovascular, affecting 126 (34.6%) patients. CONCLUSIONS: The cohort of patients studied had a low mortality rate. Cardiovascular disease remains the most common cause of death in end-stage chronic kidney disease. Screening for cardiovascular disease is highly recommended for those patients.


Subject(s)
Kidney Failure, Chronic/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Retrospective Studies , Time Factors , Young Adult
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