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1.
Semin Oncol Nurs ; 39(4): 151452, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37331879

RESUMO

OBJECTIVES: Few studies examine sexual orientation disclosures (SODs) among women with breast cancer; fewer examine the impact of culture and geography on disclosure processes. This study explores how sexual minority women (SMW) in the Southern United States engage in SODs with oncology clinicians. DATA SOURCES: We conducted in-depth interviews with SMW (eg, lesbian, bisexual) treated for early-stage (stages I-III), hormone receptor-positive breast cancer (N = 12), using a semistructured interview guide. Participants completed an online survey prior to the 60-minute interview. Data was analyzed using an adapted pile sorting approach and thematic analysis conventions. CONCLUSION: Average age of participants was 49.5 years (range: 30-69), all self-identified as cisgender; 83.3% as lesbian, 58.3% were married, 91.7% had completed a 4-year college degree or higher, 66.7% identified as non-Hispanic White, 16.7% as Black, and 16.7% as Hispanic/Latina. Half of the sample had not engaged in SODs with an oncology clinician. Key themes were: (1) religious and political conservatism in the South create SOD barriers; (2) oncologist-specific barriers to SODs; (3) "straight passing" as a discrimination mitigation strategy; and (4) SOD facilitators in oncology settings (ie, strategic disclosures, medical privilege, and lesbian, gay, bisexual, and transgender-friendly branding of oncology centers). IMPLICATIONS FOR NURSING PRACTICE: SMW with breast cancer living in the U.S. South navigate unique interpersonal barriers to SODs in oncology settings. Clinicians could encourage SODs by fostering inclusive environments via nonheteronormative language, inclusive intake forms, and respect for SMW's SOD navigation processes. Oncology clinicians require culturally relevant, geographic-specific communication training to facilitate SODs among SMW.


Assuntos
Neoplasias da Mama , Minorias Sexuais e de Gênero , Humanos , Feminino , Masculino , Estados Unidos , Adulto , Pessoa de Meia-Idade , Idoso , Neoplasias da Mama/terapia , Revelação , Comportamento Sexual , Superóxido Dismutase
2.
Bioorg Med Chem ; 82: 117217, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36889150

RESUMO

Complex natural products that bind to tubulin/microtubules come under the broad category of microtubule binding agents. The design of simplified analogs of previously reported bicyclic, microtubule depolymerizer, pyrrolo[2,3-d]pyrimidine, provided valuable structure-activity relationship data and led to the identification of novel monocyclic pyrimidine analogs of which 12 was 47-fold more potent (EC50 123 nM) for cellular microtubule depolymerization activity and 7.5-fold more potent (IC50 24.4 nM) at inhibiting the growth of MDA-MB-435 cancer cells, suggesting significantly better binding of the target within the colchicine site of tubulin compared to lead compound 1. This compound and others of this series of monocyclic pyrimidine analogs were able to overcome multidrug resistance due to the expression of the ßIII-isotype of tubulin and P-glycoprotein. In vivo evaluation of the most potent analog 12 in an MDA-MB-435 xenograft mouse model indicated, along with paclitaxel, that both compounds showed a trend towards lower tumor volume however neither compound showed significant antitumor activity in the trial. To our knowledge these are the first examples of simple substituted monocyclic pyrimidines as colchicine site binding antitubulin compounds with potent antitumor activity.


Assuntos
Antineoplásicos , Colchicina , Humanos , Camundongos , Animais , Colchicina/farmacologia , Colchicina/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Microtúbulos/metabolismo , Relação Estrutura-Atividade , Pirimidinas/química , Antineoplásicos/química , Linhagem Celular Tumoral , Sítios de Ligação , Proliferação de Células
3.
J Oncol Pharm Pract ; 29(8): 1957-1964, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36883245

RESUMO

OBJECTIVE: To pilot test a mobile health intervention using a CONnected CUstomized Treatment Platform that integrates a connected electronic adherence monitoring smartbox and an early warning system of non-adherence with bidirectional automated texting feature and provider alerts. METHODS: In total, 29 adult women with hormone-receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer and a prescription for palbociclib were asked to complete a survey and participate in a CONnected CUstomized Treatment Platform intervention, including use of a smartbox for real-time adherence monitoring, which triggered text message reminders for any missed or extra dose, and referrals to (a) participant's oncology provider after three missed doses or an episode of over-adherence, or (b) a financial navigation program for any cost-related missed dose. Use of smartbox, number of referrals, palbociclib adherence, CONnected CUstomized Treatment Platform usability measured by System Usability Scale, and changes in symptom burden and quality of life were assessed. RESULTS: Mean age was 57.6 and 69% were white. The smartbox was used by 72.4% of participants, with palbociclib adherence rate of 95.8%±7.6%. One participant was referred to oncology provider due to missed doses and one was referred to financial navigation. At baseline, 33.3% reported at least one adherence barrier including inconvenience to get prescription filled, forgetfulness, cost, and side effects. There were no changes in self-reported adherence, symptom burden or quality of life over 3 months. CONnected CUstomized Treatment Platform usability score was 61.9 ± 14.2. CONCLUSION: The CONnected CUstomized Treatment Platform interventions is feasible, resulting in a high palbociclib adherence rate without any decline in overtime. Future efforts should focus on improving usability.


Assuntos
Neoplasias da Mama , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama/patologia , Projetos Piloto , Qualidade de Vida , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Receptor ErbB-2/metabolismo
4.
Cancer Med ; 12(5): 6190-6199, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36258654

RESUMO

BACKGROUND: Cancer treatment requires substantial demands on patients and their caregivers. Mobile apps can provide support for self-management during oncology treatment, but few have been rigorously evaluated. METHODS: A 3-month randomized controlled trial was conducted at a large cancer center to evaluate the efficacy of an app (LivingWith®) that provides self-management support during cancer treatment on quality of life and health care utilization. Patients in chemotherapy treatment were randomized into the intervention (n = 113) and control group (n = 111). Intervention group participants agreed to use the app weekly for 3 months, and all participants completed a survey at enrollment and after 3 months to evaluate changes in quality of life and health care utilization. RESULTS: Retention rate was 75.4% with 169 participants completing the follow-up survey. The intervention group reported 0.74 fewer medical office visits (p = 0.043) and 0.24 fewer visits with a mental health professional (p = 0.061) during the 3 and month intervention compared with controls. There were no significant changes by study group in quality of life, or emergency room and urgent care visits. Among intervention participants, 75.3% reported using the app and on average, used it 11.7 times during the 3-month intervention. Reasons for not using the app among intervention participants included lack of time, lack of interest in apps, and usability challenges. CONCLUSIONS AND RELEVANCE: Apps are inexpensive and scalable tools that can provide additional support for individuals coping with complex cancer treatments. This trial provides evidence that a well-designed oncology support app used during chemotherapy resulted in fewer clinic visits. Still, nearly a quarter of participants randomized to the intervention arm reported never using the app due to personal preference and usability challenges, which points to future opportunities for calibrating target user population and improving user-centered design. CLINICALTRIALS: gov identifier: NCT04331678.


Assuntos
Aplicativos Móveis , Neoplasias , Humanos , Qualidade de Vida , Oncologia , Neoplasias/tratamento farmacológico , Assistência Ambulatorial
5.
J Hematol Oncol ; 15(1): 146, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36242092

RESUMO

DNA lesions induced by alkylating agents are repaired by two canonical mechanisms, base excision repair dependent on poly(ADP) ribose polymerase 1 (PARP1) and the other mediated by O6-methylguanine (O6meG)-DNA methyltransferase (MGMT) in a single-step catalysis of alkyl-group removal. O6meG is the most cytotoxic and mutagenic lesion among the methyl adducts induced by alkylating agents. Although it can accomplish the dealkylation reaction all by itself as a single protein without associating with other repair proteins, evidence is accumulating that MGMT can form complexes with repair proteins and is highly regulated by a variety of post-translational modifications, such as phosphorylation, ubiquitination, and others. Here, we show that PARP1 and MGMT proteins interact directly in a non-catalytic manner, that MGMT is subject to PARylation by PARP1 after DNA damage, and that the O6meG repair is enhanced upon MGMT PARylation. We provide the first evidence for the direct DNA-independent PARP1-MGMT interaction. Further, PARP1 and MGMT proteins also interact via PARylation of MGMT leading to formation of a novel DNA damage inducible PARP1-MGMT protein complex. This catalytic interaction activates O6meG repair underpinning the functional crosstalk between base excision and MGMT-mediated DNA repair mechanisms. Furthermore, clinically relevant 'chronic' temozolomide exposure induced PARylation of MGMT and increased binding of PARP1 and MGMT to chromatin in cells. Thus, we provide the first mechanistic description of physical interaction between PARP1 and MGMT and their functional cooperation through PARylation for activation of O6meG repair. Hence, the PARP1-MGMT protein complex could be targeted for the development of advanced and more effective cancer therapeutics, particularly for cancers sensitive to PARP1 and MGMT inhibition.


Assuntos
O(6)-Metilguanina-DNA Metiltransferase , Ribose , Difosfato de Adenosina , Alquilantes/toxicidade , Cromatina , DNA , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Reparo do DNA , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Guanina/análogos & derivados , Humanos , O(6)-Metilguanina-DNA Metiltransferase/genética , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Proteínas Supressoras de Tumor/genética
6.
iScience ; 25(2): 103725, 2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35098099

RESUMO

Current therapy is ineffective for relapsed and metastatic Ewing sarcoma (EwS) owing to development of drug resistance. Macromolecular prodrugs potentially lead to lower drug exposure in normal tissues and reduced toxicity. We evaluated the efficacy of PEGylated talazoparib (PEG∼TLZ), a PARP1 inhibitor, alone or in combination with the DNA-alkylating agent temozolomide (TMZ) in EwS and other pediatric tumors using conventional testing or single-mouse trial (SMT). A single dose of PEG∼TLZ (10 µmol/kg on day 0) combined with 5 daily doses of TMZ (40 mg/kg starting on day 3/4) produced minimal toxicity, and the combination achieved maintained complete response in EwS and glioblastoma models. The SMT trial with the 3-day interval between PEG∼TLZ and TMZ resulted in objective responses in EwS and other xenografts. Thus, PEG∼TLZ + TMZ demonstrated a broad range of activity in pediatric solid tumor models. Furthermore, the therapeutic window of PEG∼TLZ + TMZ was enhanced compared with the free-TLZ combination.

7.
Molecules ; 27(1)2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35011550

RESUMO

A series of eleven 4-substituted 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidines were designed and synthesized and their biological activities were evaluated. Synthesis involved the Gewald reaction to synthesize ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate ring, and SNAr reactions. Compound 4 was 1.6- and ~7-fold more potent than the lead compound 1 in cell proliferation and microtubule depolymerization assays, respectively. Compounds 4, 5 and 7 showed the most potent antiproliferative effects (IC50 values < 40 nM), while compounds 6, 8, 10, 12 and 13 had lower antiproliferative potencies (IC50 values of 53-125 nM). Additionally, compounds 4-8, 10 and 12-13 circumvented Pgp and ßIII-tubulin mediated drug resistance, mechanisms that diminish the clinical efficacy of paclitaxel (PTX). In the NCI-60 cell line panel, compound 4 exhibited an average GI50 of ~10 nM in the 40 most sensitive cell lines. Compound 4 demonstrated statistically significant antitumor effects in a murine MDA-MB-435 xenograft model.


Assuntos
Técnicas de Química Sintética , Desenho de Fármacos , Pirimidinas/química , Pirimidinas/farmacologia , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Multimerização Proteica/efeitos dos fármacos , Pirimidinas/síntese química , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese química
8.
Cancers (Basel) ; 13(24)2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34944795

RESUMO

A screening program designed to identify natural products with selective cytotoxic effects against cell lines representing different types of pediatric solid tumors led to the identification of altertoxin II as a highly potent and selective cytotoxin against Ewing sarcoma cell lines. Altertoxin II, but not the related compounds altertoxin I and alteichin, was highly effective against every Ewing sarcoma cell line tested, with an average 25-fold selectivity for these cells as compared to cells representing other pediatric and adult cancers. Mechanism of action studies revealed that altertoxin II causes DNA double-strand breaks, a rapid DNA damage response, and cell cycle accumulation in the S phase. Our studies also demonstrate that the potent effects of altertoxin II are partially dependent on the progression through the cell cycle, because the G1 arrest initiated by a CDK4/6 inhibitor decreased antiproliferative potency more than 10 times. Importantly, the cell-type-selective DNA-damaging effects of altertoxin II in Ewing sarcoma cells occur independently of its ability to bind directly to DNA. Ultimately, we found that altertoxin II has a dose-dependent in vivo antitumor efficacy against a Ewing sarcoma xenograft, suggesting that it has potential as a therapeutic drug lead and will be useful to identify novel targets for Ewing-sarcoma-specific therapies.

9.
Clin Cancer Res ; 26(12): 3012-3023, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32184294

RESUMO

PURPOSE: Vincristine combined with camptothecin derivatives showed synergy in preclinical pediatric cancer models, and the combinations are effective in treatment of childhood solid tumors. We determined whether the synergy between vincristine and irinotecan extends to eribulin, another microtubule inhibitor. EXPERIMENTAL DESIGN: Vincristine or eribulin, alone or combined with irinotecan, was studied in 12 xenograft models. Tumor regression and time to event were used to assess antitumor activity. Pharmacodynamic studies and RNA sequencing (RNA-seq) were conducted 24 and 144 hours after single-agent or combination treatment. Effects on vascular development were studied in Matrigel plugs implanted in mice. The interaction between binary combinations was examined in vitro. RESULTS: Eribulin combined with irinotecan was more effective than vincristine-irinotecan in 6 of 12 models. Pharmacodynamic markers induced by eribulin (phospho-histone H3) and irinotecan (γ-H2A.X) were abrogated in combination-treated tumors. The predominant RNA-seq signature in combination-treated tumors was activation of the TP53 pathway with increased nuclear TP53. Massive apoptosis was observed 24 hours only after treatment with the eribulin combination. In vitro, neither combination showed interaction using combination index analysis. Eribulin alone and the combination caused alterations in developing vasculature. CONCLUSIONS: The eribulin combination is very active in these xenograft models, but not synergistic in vitro. The combination reduced pharmacodynamic markers indicative of single-agent mechanisms but in tumors, dramatically activated the TP53 pathway. Although a mechanism for in vivo synergy requires further study, it is possible that eribulin-induced inhibition of microtubule dynamics enhances irinotecan-induced nuclear accumulation of TP53, leading to rapid cell death.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Renais/tratamento farmacológico , Rabdomiossarcoma/tratamento farmacológico , Tumor de Wilms/tratamento farmacológico , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Feminino , Furanos/administração & dosagem , Perfilação da Expressão Gênica , Humanos , Irinotecano/administração & dosagem , Cetonas/administração & dosagem , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Camundongos , Camundongos SCID , Prognóstico , Rabdomiossarcoma/genética , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/patologia , Células Tumorais Cultivadas , Vincristina/administração & dosagem , Tumor de Wilms/genética , Tumor de Wilms/metabolismo , Tumor de Wilms/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
J Med Chem ; 60(22): 9275-9289, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29053266

RESUMO

Targeted therapies for ER+/PR+ and HER2-amplified breast cancers have improved patient survival, but there are no therapies for triple negative breast cancers (TNBC) that lack expression of estrogen and progesterone receptors (ER/PR), or amplification or overexpression of HER2. Gene expression profiling of TNBC has identified molecular subtypes and representative cell lines. An extract of the Texas native plant Amyris texana was found to have selective activity against MDA-MB-453 cells, a model of the luminal androgen receptor (LAR) subtype of TNBC. Bioassay-guided fractionation identified two oxazole natural products with selective activity against this cell line. Conducted analog synthesis and structure-activity relationship studies provided analogs with more potent and selective activity against two LAR subtype cell line models, culminating in the discovery of compound 30 (CIDD-0067106). Lead compounds discovered have potent and selective antiproliferative activities, and mechanisms of action studies show they inhibit the activity of the mTORC1 pathway.


Assuntos
Antineoplásicos/farmacologia , Imidazóis/farmacologia , Oxazóis/farmacologia , Prolina/análogos & derivados , Receptores Androgênicos/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Antineoplásicos/síntese química , Antineoplásicos/isolamento & purificação , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imidazóis/síntese química , Imidazóis/isolamento & purificação , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Oxazóis/síntese química , Oxazóis/isolamento & purificação , Prolina/síntese química , Prolina/isolamento & purificação , Prolina/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Rutaceae/química , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Neoplasias de Mama Triplo Negativas/metabolismo
11.
J Nat Prod ; 80(2): 409-414, 2017 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-28112516

RESUMO

The taccalonolides are microtubule stabilizers that covalently bind tubulin and circumvent clinically relevant forms of resistance to other drugs of this class. Efforts are under way to identify a taccalonolide with optimal properties for clinical development. The structurally similar taccalonolides AF and AJ have comparable microtubule-stabilizing activities in vitro, but taccalonolide AF has excellent in vivo antitumor efficacy when administered systemically, while taccalonolide AJ does not elicit this activity even at maximum tolerated dose. The hypothesis that pharmacokinetic differences underlie the differential efficacies of taccalonolides AF and AJ was tested. The effects of serum on their in vivo potency, metabolism by human liver microsomes and in vivo pharmacokinetic properties were evaluated. Taccalonolides AF and AJ were found to have elimination half-lives of 44 and 8.1 min, respectively. Furthermore, taccalonolide AJ was found to have excellent and highly persistent antitumor efficacy when administered directly to the tumor, suggesting that the lack of antitumor efficacy seen with systemic administration of AJ is likely due to its short half-life in vivo. These results help define why some, but not all, taccalonolides inhibit the growth of tumors at systemically tolerable doses and prompt studies to further improve their pharmacokinetic profile and antitumor efficacy.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Esteroides/farmacocinética , Moduladores de Tubulina/farmacocinética , Animais , Humanos , Microtúbulos/efeitos dos fármacos , Estrutura Molecular , Esteroides/química , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química
12.
Breast Cancer Res Treat ; 157(3): 475-88, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27255535

RESUMO

Triple-negative breast cancers (TNBC) are aggressive malignancies with no effective targeted therapies. Recent gene expression profiling of these heterogeneous cancers and the classification of cell line models now allows for the identification of compounds with selective activities against molecular subtypes of TNBC. The natural product deguelin was found to have selective activity against MDA-MB-453 and SUM-185PE cell lines, which both model the luminal androgen receptor (LAR) subtype of TNBC. Deguelin potently inhibited proliferation of these cells with GI50 values of 30 and 61 nM, in MDA-MB-453 and SUM-185PE cells, respectively. Deguelin had exceptionally high selectivity, 197 to 566-fold, for these cell lines compared to cell lines representing other TNBC subtypes. Deguelin's mechanisms of action were investigated to determine how it produced these potent and selective effects. Our results show that deguelin has dual activities, inhibiting PI3K/Akt/mTOR signaling, and decreasing androgen receptor levels and nuclear localization. Based on these data, we hypothesized that the combination of the mTOR inhibitor rapamycin and the antiandrogen enzalutamide would have efficacy in LAR models. Rapamycin and enzalutamide showed additive effects in MDA-MB-453 cells, and both drugs had potent antitumor efficacy in a LAR xenograft model. These results suggest that the combination of antiandrogens and mTOR inhibitors might be an effective strategy for the treatment of androgen receptor-expressing TNBC.


Assuntos
Antineoplásicos/administração & dosagem , Feniltioidantoína/análogos & derivados , Receptores Androgênicos/metabolismo , Rotenona/análogos & derivados , Sirolimo/administração & dosagem , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Benzamidas , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Nitrilas , Feniltioidantoína/administração & dosagem , Feniltioidantoína/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Rotenona/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
J Nat Prod ; 79(7): 1822-7, 2016 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-27310425

RESUMO

Triple-negative breast cancers are highly aggressive, and patients with these types of tumors have poor long-term survival. These breast cancers do not express estrogen or progesterone receptors and do not have gene amplification of human epidermal growth factor receptor 2; therefore, they do not respond to available targeted therapies. The lack of targeted therapies for triple-negative breast cancers stems from their heterogeneous nature and lack of a clear definition of driver defects. Studies have recently identified triple-negative breast cancer molecular subtypes based on gene expression profiling and representative cell lines, allowing for the identification of subtype-specific drug leads and molecular targets. We previously reported the identification of a new fungal metabolite named maximiscin (1) identified through a crowdsourcing program. New results show that 1 has selective cytotoxic efficacy against basal-like 1 MDA-MB-468 cells compared to cell lines modeling other triple-negative breast cancer molecular subtypes. This compound also exhibited antitumor efficacy in a xenograft mouse model. The mechanisms of action of 1 in MDA-MB-468 cells were investigated to identify potential molecular targets and affected pathways. Compound 1 caused accumulation of cells in the G1 phase of the cell cycle, suggesting induction of DNA damage. Indeed, treatment with 1 caused DNA double-strand breaks with concomitant activation of the DNA damage response pathways, indicated by phosphorylation of p53, Chk1, and Chk2. Collectively, these results suggest basal-like triple-negative breast cancer may be inherently sensitive to DNA-damaging agents relative to other triple-negative breast cancer subtypes. These results also demonstrate the potential of our citizen crowdsourcing program to identify new lead molecules for treating the subtypes of triple-negative breast cancer.


Assuntos
Antineoplásicos/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Feminino , Compostos Heterocíclicos de 4 ou mais Anéis/química , Humanos , Camundongos , Estrutura Molecular , Receptor ErbB-2/metabolismo , Receptores de Progesterona , Ensaios Antitumorais Modelo de Xenoenxerto
14.
J Nat Prod ; 79(3): 531-40, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-26785306

RESUMO

There remains a critical need for more effective therapies for the treatment of late-stage and metastatic prostate cancers. Three Texas native plants yielded three new and three known compounds with antiproliferative and cytotoxic activities against prostate cancer cells with IC50 values in the range of 1.7-35.0 µM. A new sesquiterpene named espadalide (1), isolated from Gochnatia hypoleuca, had low micromolar potency and was highly effective in clonogenic assays. Two known bioactive germacranolides (2 and 3) were additionally isolated from G. hypoleuca. Dalea frutescens yielded two new isoprenylated chalcones, named sanjuanolide (4) and sanjoseolide (5), and the known sesquiterpenediol verbesindiol (6) was isolated from Verbesina virginica. Mechanistic studies showed that 1-4 caused G2/M accumulation and the formation of abnormal mitotic spindles. Tubulin polymerization assays revealed that 4 increased the initial rate of tubulin polymerization, but did not change total tubulin polymer levels, and 1-3 had no effects on tubulin polymerization. Despite its cytotoxic activity, compound 6 did not initiate changes in cell cycle distribution and has a mechanism of action different from the other compounds. This study demonstrates that new compounds with significant biological activities germane to unmet oncological needs can be isolated from Texas native plants.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Chalconas/isolamento & purificação , Chalconas/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Sesquiterpenos de Germacrano/isolamento & purificação , Sesquiterpenos de Germacrano/farmacologia , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Antineoplásicos/química , Ciclo Celular/efeitos dos fármacos , Chalconas/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Sesquiterpenos de Germacrano/química , Texas , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologia
15.
Health Promot Pract ; 17(1): 21-30, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26630979

RESUMO

Anal cancer disproportionately burdens persons living with human immunodeficiency virus (PLHIV) regardless of natal sex, sexual orientation, gender expression, and ethnic identity. Culturally competent communications are recommended to address health disparities, with sociocultural relevance ensured through constituent dialogic processes. Results are presented from six provider focus groups conducted to inform the promotion/education component of a Hawai'i-based project on anal cancer screening tools. Krueger's focus group methodology guided discussion queries. Verbatim transcripts of digitally recorded discussions were analyzed using grounded theory and PEN-3 procedures. Adherence to an audit trail ensured analytic rigor. Grounded theory analysis detected the overall theme of risk and reluctance to anal cancer screening, characterized by anal cancer not being "on the radar" of PLHIV, conflicting attributions of the anus and anal sex, fear of sex-shaming/-blaming, and other interrelated conceptual categories. PEN-3 analysis revealed strategies for destigmatizing anal cancer, through "real talk" (proactive, candid, nonjudgmental discussion) nested in a framework of sexual health and overall well-being, with additional tailoring for relevance to Native Hawaiians/Pacific Islanders, transgender persons, and other marginalized groups. Application of strategies for health practice are specific to the Hawai'i context, yet may offer considerations for developing strengths-based, culturally relevant screening promotion/education with diverse PLHIV in other locales.


Assuntos
Neoplasias do Ânus/psicologia , Havaiano Nativo ou Outro Ilhéu do Pacífico/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/etnologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Adulto , Idoso , Neoplasias do Ânus/diagnóstico , Competência Cultural , Detecção Precoce de Câncer , Feminino , Grupos Focais , Infecções por HIV/diagnóstico , Infecções por HIV/psicologia , Havaí , Conhecimentos, Atitudes e Prática em Saúde , Promoção da Saúde , Disparidades nos Níveis de Saúde , Humanos , Masculino , Pessoa de Meia-Idade
17.
J Nat Prod ; 78(3): 388-95, 2015 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-25685941

RESUMO

A new tricyclic sesquiterpene, named meleucanthin (1), was isolated from an extract of the leaves and branches of Melampodium leucanthum, along with four known germacranolide sesquiterpene lactones, leucanthin-A (2), leucanthin-B (3), melampodin-A acetate (4), and 3α-hydroxyenhydrin (5). The chemical structure of 1 was elucidated by analysis of 1D and 2D NMR and mass spectrometric data. All compounds exhibited antiproliferative and cytotoxic efficacy against PC-3 and DU 145 prostate cancer cells, as well as HeLa cervical cancer cells, with IC50 values ranging from 0.18 to 9 µM. These compounds were effective in clonogenic assays and displayed high cellular persistence. They were also found to be capable of circumventing P-glycoprotein-mediated drug resistance. Mechanism of action studies showed that 4 caused an accumulation of cells in the G2/M phase of the cell cycle, and 2-5 caused the formation of abnormal mitotic spindles. These results suggest the cytotoxic effects of these germacranolides involve inhibition of mitotic spindle function, and it is likely that other mechanisms additionally contribute to cell death. These studies also demonstrate the possibility of isolating new, biologically active compounds from indigenous Texas plants.


Assuntos
Antimitóticos/isolamento & purificação , Antimitóticos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Asteraceae/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Antimitóticos/química , Antineoplásicos Fitogênicos/química , Ciclo Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células HeLa , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/química , Texas
18.
J Nat Prod ; 77(6): 1459-66, 2014 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-24893224

RESUMO

Two new dimeric epipolythiodiketopiperazines, preussiadins A (1) and B (2), together with two known diastereomers, leptosins C (6) and A (7), were obtained from the mycelia of a Preussia typharum isolate. The structures of the new compounds were established by spectroscopic methods, and the absolute configurations of 1 and 2 were assigned by chemical transformations and comparisons of quantum chemical ECD and VCD calculations to experimental data. Compound 1 exhibited potent cytotoxic activity in the NCI-60 cell line panel with an average LC50 value of 251 nM. Further studies demonstrated that 1 circumvents P-glycoprotein-mediated drug resistance, yet had no significant antitumor activity in a xenograft UACC-62 melanoma model.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Ascomicetos/química , Piperazinas/isolamento & purificação , Piperazinas/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/farmacologia , Animais , Antineoplásicos/química , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Melanoma/patologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Piperazinas/química
19.
Redox Biol ; 2: 259-66, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24494201

RESUMO

AIMS: Dietary supplementation with ursolic acid (UA) prevents monocyte dysfunction in diabetic mice and protects mice against atherosclerosis and loss of renal function. The goal of this study was to determine the molecular mechanism by which UA prevents monocyte dysfunction induced by metabolic stress. METHODS AND RESULTS: Metabolic stress sensitizes or "primes" human THP-1 monocytes and murine peritoneal macrophages to the chemoattractant MCP-1, converting these cells into a hyper-chemotactic phenotype. UA protected THP-1 monocytes and peritoneal macrophages against metabolic priming and prevented their hyper-reactivity to MCP-1. UA blocked the metabolic stress-induced increase in global protein-S-glutathionylation, a measure of cellular thiol oxidative stress, and normalized actin-S-glutathionylation. UA also restored MAPK phosphatase-1 (MKP1) protein expression and phosphatase activity, decreased by metabolic priming, and normalized p38 MAPK activation. Neither metabolic stress nor UA supplementation altered mRNA or protein levels of glutaredoxin-1, the principal enzyme responsible for the reduction of mixed disulfides between glutathione and protein thiols in these cells. However, the induction of Nox4 by metabolic stress, required for metabolic priming, was inhibited by UA in both THP-1 monocytes and peritoneal macrophages. CONCLUSION: UA protects THP-1 monocytes against dysfunction by suppressing metabolic stress-induced Nox4 expression, thereby preventing the Nox4-dependent dysregulation of redox-sensitive processes, including actin turnover and MAPK-signaling, two key processes that control monocyte migration and adhesion. This study provides a novel mechanism for the anti-inflammatory and athero- and renoprotective properties of UA and suggests that dysfunctional blood monocytes may be primary targets of UA and related compounds.


Assuntos
Macrófagos Peritoneais/metabolismo , Monócitos/metabolismo , NADPH Oxidases/metabolismo , Triterpenos/farmacologia , Actinas/metabolismo , Animais , Quimiocina CCL2/metabolismo , Suplementos Nutricionais , Regulação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glutarredoxinas/genética , Glutarredoxinas/metabolismo , Glutationa/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos Peritoneais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/citologia , NADPH Oxidase 4 , Estresse Fisiológico/efeitos dos fármacos , Ácido Ursólico
20.
Angew Chem Int Ed Engl ; 53(3): 804-9, 2014 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-24285637

RESUMO

A fundamental component for success in drug discovery is the ability to assemble and screen compounds that encompass a broad swath of biologically relevant chemical-diversity space. Achieving this goal in a natural-products-based setting requires access to a wide range of biologically diverse specimens. For this reason, we introduced a crowdsourcing program in which citizen scientists furnish soil samples from which new microbial isolates are procured. Illustrating the strength of this approach, we obtained a unique fungal metabolite, maximiscin, from a crowdsourced Alaskan soil sample. Maximiscin, which exhibits a putative combination of polyketide synthase (PKS), non-ribosomal peptide synthetase (NRPS), and shikimate pathway components, was identified as an inhibitor of UACC-62 melanoma cells (LC50=0.93 µM). The metabolite also exhibited efficacy in a xenograft mouse model. These results underscore the value of building cooperative relationships between research teams and citizen scientists to enrich drug discovery efforts.


Assuntos
Antineoplásicos/metabolismo , Produtos Biológicos/metabolismo , Fungos/metabolismo , Metionina/metabolismo , Tirosina/metabolismo , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Produtos Biológicos/uso terapêutico , Produtos Biológicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Humanos , Melanoma/tratamento farmacológico , Metionina/química , Metionina/toxicidade , Camundongos , Conformação Molecular , Peptídeo Sintases/metabolismo , Policetídeos/química , Policetídeos/metabolismo , Pseudomonas/metabolismo , Ácido Chiquímico/química , Ácido Chiquímico/metabolismo , Transplante Heterólogo , Tirosina/química , Tirosina/toxicidade
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