121 research outputs found
Up-regulation of Skp2 after prostate cancer cell adhesion to basement membranes results in BRCA2 degradation and cell proliferation.
Aberrant interaction of carcinoma cells with basement membranes (BM) is a fundamental pathophysiological process that initiates a series of events resulting in cancer cell invasion and metastasis. In this report, we describe the results of our investigations pertaining to the events triggered by the adhesion of normal (PNT1A) and highly metastatic (PC-3) prostate cells onto BM proteins. Unlike PNT1A, PC-3 cells adhered avidly to Matrigel BM matrix as well as to isolated collagen type IV, laminin, and heparan sulfate proteoglycan perlecan, main BM components. This aberrantly increased cancer cell adhesion resulted in sustained BRCA2 protein depletion and vigorous cell proliferation, a cascade triggered by beta1 integrin-mediated phosphatidylinositol 3-kinase activation leading to BRCA2 degradation in the proteasome. This latter effect was orchestrated by phosphatidylinositol 3-kinase-dependent up-regulation of Skp2, a subunit of the Skp1-Cul1-F-box protein ubiquitin complex that directly associates with BRCA2 as demonstrated by coimmunoprecipitation assays, determines its ubiquitination, and ultimately targets it for proteasomal degradation. Inhibition of Skp2 expression by small interference RNA prevented BRCA2 depletion and inhibited the trophic effect upon cell proliferation. These results provide additional evidence on the role of BRCA2 as a modulator of cancer cell growth and elucidate the molecular mechanisms involved in its down-regulation in cancer cells when interacting with BM, a crucial step in the biology of metastasis. Furthering the understanding of this molecular pathway may prove valuable in designing new therapeutic strategies aimed at modifying the natural history of prostate carcinoma
Intravascular large B-cell lymphoma with multi-organ failure presenting as a pancreatic mass: a case with atypical presentation and definite diagnosis postmortem
Intravascular large B-cell lymphoma (IVLBCL) is a very rare extra nodal lymphoma that tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules while sparing the organ parenchyma. The cause of its affinity for the vascular bed remains unknown. Because of its rarity and unremarkable clinical presentation, a timely diagnosis of IVLBCL is very challenging. Here, we describe a case of IVLBCL presenting as pancreatic mass that was ultimately diagnosed at autopsy. A 71-year-old Caucasian female presented with a 3-month history of fatigue, abdominal pain, and weight loss. She was referred to the emergency room with a new diagnosis of portal vein thrombosis and lactic acidosis. During her hospital course she was found to have a 1.9 × 1.8 cm lesion in the pancreatic tail on imaging; The cytologic specimen on the mass showed a high-grade lymphoma. A bone marrow biopsy showed no involvement. The patient’s condition rapidly deteriorated and she, later, died due to multi-organ failure. An autopsy revealed diffuse intravascular invasion in multiple organs by the lymphoma cells. Based on our literature review—and to the best of our knowledge—there are virtually no reports escribing the presentation of this lymphoma with a discernible tissue mass and associated multi-organ failure. The immunophenotypic studies performed revealed de novo CD5+ intravascular large B-cell lymphoma, which is known to be aggressive with very poor prognosis. Although it is a very rare lymphoma, it should be considered as a potential cause of multi-organ failure when no other cause has been identified. A prompt tissue diagnosis, appropriate high-dose chemotherapy and stem cell transplantation remain the only viable alternative to achieve some kind of remission
BRCA2 Mutations in Prostate Cancer: A Literature Review
Background: Prostate cancer is one of the most frequently diagnosed neoplastic disease and the second leading cause of cancer mortality in men of the Western world. Despite improved methods for early detection, a large proportion of patients succumb to metastatic prostate cancer that is resistant to conventional therapies. The development of novel effective strategies to prevent and treat prostate cancer relies considerably upon increasing our knowledge of the interplay among various molecular and genetic alterations that lead to onset and progression of prostate cancer. To date, germline mutations in the cancer susceptibility gene BRCA2 represent one of the strongest risk factor to develop prostate cancer.Objective: Goal of this review is to summarize current reports investigating the presence of BRCA2 mutations in prostate cancer.Design: A comprehensive analysis of the literature on BRCA2 mutations in prostate cancer. Data source: Pubmed. Terms included in the search: "BRCA2 mutations", "prostate cancer".Results: A total of 18 studies were included in the review. The studies focused on the clinical implications of BRCA2 mutations in prostate cancer. The findings indicate that inherited pathogenic mutations in BRCA2 predispose to highly aggressive prostate cancers and poor survival. Very recent reports also suggest that metastatic castration-resistant prostate cancers are "enriched" of BRCA2 mutations compared to the primary tumors.Conclusion: Because BRCA2-mutated tumors are very sensitive to PARP-inhibitors'-based chemotherapy, BRCA2 genomic testing of patients with advanced metastatic prostate disease may enable an effective, personalized, therapeutic strategy
Mitochondrial Genome Mutations and Pathological Features of Prostate Cancer: an Update
Mitochondria are organelles involved in a variety of cellular functions that are central to the life and death of a cell. Oxidative phosphorylation (OXPHOS), the main energy provider of the cell, takes place inside mitochondria and is known to be altered in carcinogenesis and tumor progression contributing to the “metabolic reprogrammingâ€, one of the hallmarks of cancer cells. Due to the central role of energy metabolism in cancer cell pathogenesis, mutations in the mitochondrial genome (mtDNA), which encodes for essential components of the OXPHOS pathway, have been suggested to play a role in many cancers, including prostate cancer. Recent studies provide evidence for increased levels of mutant mtDNA in prostate cancer patients with higher Gleason grade and relapse, as well as in bone metastatic sites. In this review, we will provide an overview of recent studies investigating the presence of mtDNA mutations in prostate cancer cells and their significance in the context of clinical pathological features of prostate cancer
The Isotropic Fractionator as a Tool for Quantitative Analysis in Central Nervous System Diseases
One major aim in quantitative and translational neuroscience is to achieve a precise and fast neuronal counting method to work on high throughput scale to obtain reliable results.Here we tested the Isotropic Fractionator (IF) method for evaluating neuronal and non-neuronal cell loss in different models of central nervous system (CNS) pathologies.Sprague-Dawley rats underwent: (i) ischemic brain damage; (ii) intraperitoneal injection with kainic acid (KA) to induce epileptic seizures; and (iii) monolateral striatal injection with quinolinic acid (QA) mimicking human Hungtington’s disease.All specimens were processed for IF method and cell loss assessed.Hippocampus from KA-treated rats and striatum from QA-treated rats were carefully dissected using a dissection microscope and a rat brain matrix. Ischemic rat brains slices were first processed for TTC staining and then for IF.In the ischemic group the cell loss corresponded to the neuronal loss suggesting that hypoxia primarily affects neurons. Combining IF with TTC staining we could correlate the volume of lesion to the neuronal loss; by IF, we could assess that neuronal loss also occurs contralaterally to the ischemic side.In the epileptic group we observed a reduction of neuronal cells in treated rats, but also evaluated the changes in the number of non-neuronal cells in response to the hippocampal damage
Intravascular large B-cell lymphoma with multi-organ failure presenting as a pancreatic mass: a case with atypical presentation and definite diagnosis postmortem
Intravascular large B-cell lymphoma (IVLBCL) is a very rare extra nodal lymphoma that tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules while sparing the organ parenchyma. The cause of its affinity for the vascular bed remains unknown. Because of its rarity and unremarkable clinical presentation, a timely diagnosis of IVLBCL is very challenging. Here, we describe a case of IVLBCL presenting as pancreatic mass that was ultimately diagnosed at autopsy. A 71-year-old Caucasian female presented with a 3-month history of fatigue, abdominal pain, and weight loss. She was referred to the emergency room with a new diagnosis of portal vein thrombosis and lactic acidosis. During her hospital course she was found to have a 1.9 × 1.8 cm lesion in the pancreatic tail on imaging; The cytologic specimen on the mass showed a high-grade lymphoma. A bone marrow biopsy showed no involvement. The patient’s condition rapidly deteriorated and she, later, died due to multi-organ failure. An autopsy revealed diffuse intravascular invasion in multiple organs by the lymphoma cells. Based on our literature review—and to the best of our knowledge—there are virtually no reports escribing the presentation of this lymphoma with a discernible tissue mass and associated multi-organ failure. The immunophenotypic studies performed revealed de novo CD5+ intravascular large B-cell lymphoma, which is known to be aggressive with very poor prognosis. Although it is a very rare lymphoma, it should be considered as a potential cause of multi-organ failure when no other cause has been identified. A prompt tissue diagnosis, appropriate high-dose chemotherapy and stem cell transplantation remain the only viable alternative to achieve some kind of remission
Modulation of Mouse Coagulation Gene Transcription following Acute In Vivo Delivery of Synthetic Small Interfering RNAs Targeting HNF4α and C/EBPα
Hepatocyte nuclear factor 4α (HNF4α) and CCAAT/enhancer-binding protein α (C/EBPα) are important for the transcriptional control of coagulation factors. To determine in vivo the direct role of HNF4α and C/EBPα in control of genes encoding coagulation factors, a synthetic small interfering (si)RNA approach was used that enabled strong reduction of mouse hepatic HNF4α and C/EBPα under conditions that minimized target-related secondary effects. For both HNF4α and C/EBPα, intravenous injection of specific synthetic siRNAs (siHNF4α and siC/EBPα) resulted in more than 75% reduction in their liver transcript and protein levels 2 days post-injection. For siHNF4α, this coincided with marked and significantly reduced transcript levels of the coagulation genes Hrg, Proz, Serpina5, F11, F12, F13b, Serpinf2, F5, and F9 (in order of magnitude of effect) as compared to levels in control siRNA injected animals. Significant decreases in HNF4α target gene mRNA levels were also observed at 5 days post-siRNA injection, despite a limited level of HNF4α knockdown at this time point. Compared to HNF4α, C/EBPα knockdown had a modest impact on genes encoding coagulation factors. A strong reduction in C/EBPα transcript and protein levels resulted in significantly affected transcript levels of the control genes Pck1 and Fasn and a modest downregulation for coagulation genes Fba, Fbg and F5. F5 and F11 were the sole coagulation genes that were significantly affected upon prolonged (5 day) C/EBPα knockdown. We conclude that in the mouse, HNF4α has a direct and essential regulatory role for multiple hepatic coagulation genes, while a role for C/EBPα is more restricted. In addition, this study demonstrates that synthetic siRNA provides a simple and fast means for determining liver transcription factor involvement in vivo
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