Castrate-resistant prostate cancer (CRPC) is a likely outcome of hormone treatment for advanced prostate cancer. Although no longer dependent on androgen levels, CRPC remains driven by the androgen receptor (AR). One proposed progression mechanism is altered repertoires of coregulator proteins possessing the ability to alter AR activity.
View Article and Find Full Text PDFBackground: In neuroblastoma MYCN amplification is associated with enhanced angiogenesis and poor survival. Mutations in the anaplastic lymphoma kinase (ALK) gene can occur with MYCN amplification, conferring a very poor prognosis. Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF)/c-MET signalling are implicated in neuroblastoma progression.
View Article and Find Full Text PDFBackground: Current strategies to inhibit androgen receptor (AR) are circumvented in castration-resistant prostate cancer (CRPC). Cyclin-dependent kinase 7 (CDK7) promotes AR signalling, in addition to established roles in cell cycle and global transcription, providing a rationale for its therapeutic targeting in CRPC.
Methods: The antitumour activity of CT7001, an orally bioavailable CDK7 inhibitor, was investigated across CRPC models in vitro and in xenograft models in vivo.
The undruggable nature of oncogenic Myc transcription factors poses a therapeutic challenge in neuroblastoma, a pediatric cancer in which MYCN amplification is strongly associated with unfavorable outcome. Here, we show that CYC065 (fadraciclib), a clinical inhibitor of CDK9 and CDK2, selectively targeted MYCN-amplified neuroblastoma via multiple mechanisms. CDK9 - a component of the transcription elongation complex P-TEFb - bound to the MYCN-amplicon superenhancer, and its inhibition resulted in selective loss of nascent MYCN transcription.
View Article and Find Full Text PDFThis study investigates the influence expression of the MYCN oncogene has on the DNA damage response, replication fork progression and sensitivity to PARP inhibition in neuroblastoma. In a panel of neuroblastoma cell lines, amplification or MYCN expression resulted in increased cell death in response to a range of PARP inhibitors (niraparib, veliparib, talazoparib and olaparib) compared to the response seen in non-expressing/amplified cells. MYCN expression slowed replication fork speed and increased replication fork stalling, an effect that was amplified by PARP inhibition or PARP1 depletion.
View Article and Find Full Text PDFOverexpression of fatty acid synthase (FASN), a key regulator of the de novo synthesis of fatty acids, has been demonstrated in a variety of cancers and is associated with poor prognosis and increased multidrug resistance. Inhibition of FASN with the anti-obesity drug orlistat has been shown to have significant anti-tumourigenic effects in many cancers, notably breast and prostate. In our study, we investigated whether FASN inhibition using orlistat is an effective adjunctive treatment for ovarian cancers that have become platinum resistant using a cisplatin-resistant ovarian tumour xenograft model in mice.
View Article and Find Full Text PDFBackground: The use of clinical MRI scanners to conduct pre-clinical research facilitates comparisons with clinical studies. Here the utility and sensitivity of anatomical and functional MRI data/biomarkers acquired from transgenic mouse models of neuroblastoma using a dedicated radiofrequency (RF) coil on a clinical 3T scanner was evaluated.
Methods: Multiparametric MRI of transgenic mice bearing abdominal neuroblastomas was performed at 3T, and data cross-referenced to that acquired from the same mice on a pre-clinical 7T MRI system.
Poly(adenosine diphosphate ribose) polymerases (PARPs) are multifunctional proteins which play a role in many cellular processes. Namely, PARP1 and PARP2 have been shown to be involved in DNA repair, and therefore are valid targets in cancer treatment with PARP inhibitors, such as rucaparib, currently in clinical trials. Proton magnetic resonance spectroscopy ( H-MRS) was used to study the impact of rucaparib in vitro and ex vivo in liver tissue from mice, via quantitative analysis of nicotinamide adenosine diphosphate (NAD ) spectra, to assess the potential of MRS as a biomarker of the PARP inhibitor response.
View Article and Find Full Text PDFNeuroblastoma is the most common childhood extracranial solid tumor. In high-risk cases, many of which are characterized by amplification of MYCN, outcome remains poor. Mutations in the p53 (TP53) tumor suppressor are rare at diagnosis, but evidence suggests that p53 function is often impaired in relapsed, treatment-resistant disease.
View Article and Find Full Text PDFPurpose: To evaluate between-site agreement of apparent diffusion coefficient (ADC) measurements in preclinical magnetic resonance imaging (MRI) systems.
Materials And Methods: A miniaturized thermally stable ice-water phantom was devised. ADC (mean and interquartile range) was measured over several days, on 4.
Ewing sarcoma and osteosarcoma represent the two most common primary bone tumours in childhood and adolescence, with bone metastases being the most adverse prognostic factor. In prostate cancer, osseous metastasis poses a major clinical challenge. We developed a preclinical orthotopic model of Ewing sarcoma, reflecting the biology of the tumour-bone interactions in human disease and allowing in vivo monitoring of disease progression, and compared this with models of osteosarcoma and prostate carcinoma.
View Article and Find Full Text PDFAn Acad Bras Cienc
March 2002
The fluminense vegetation, more specifically the flora from the Jurubatiba restinga has been investigated by a multidisciplinary team of botanists, chemist, radiobiologist, insect physiologists and geneticist. Vouchers of 564 specimens have been collected, identified, organized in an herbarium, and a database is being build up containing, in addition to classical botanical data, chemical data and information on the potential economic use either for landscape gardening, alternative foods or as medicinal plants. Phytochemical studies of the Guttiferae, Clusia hilariana, yielded oleanolic acid and nemorosone.
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