Search results for "Neoplastic"
showing 10 items of 2901 documents
Pyrrolotetrazinones deazaanalogues of temozolomide induce apoptosis in Jurkat cell line: involvement of tubulin polymerization inhibition.
2009
Pyrrolotetrazinones are a new class of azolotetrazinones endowed with a high, remarkable antiproliferative activity in human tumor cultured cells. They hold the deaza skeleton of the antitumor drug temozolomide, although preliminary investigations indicated a different mechanism of action. To understand their mechanism(s) of action along with their target at molecular level, four derivatives were selected on the basis of their activity on a panel of human tumor cell lines and they were investigated in depth in a T leukemia cell line (Jurkat). Flow cytometric analysis of cell cycle after treatment with pyrrolotetrazinones has demonstrated that they were able to induce an arrest of the cell c…
cAMP-dependent phosphorylation of CYP2B1 as a functional switch for cyclophosphamide activation and its hormonal controlin vitro andin vivo
2001
An important feature of cytochrome P450 (CYP) 2B1 is its high ability to convert the prodrug cyclophosphamide (CPA) to therapeutically cytotoxic metabolites, resulting in interstrand DNA-cross-linking and cell death. We have examined whether and how the phosphorylation of CYP2B1 influences CPA metabolic activation in vitro and in vivo. We found first that only part of the total CYP2B1 pool undergoes phosphorylation. This part is fully inactivated. Second, phosphorylation of CYP2B1 in intact hepatocytes reduced by up to 75% toxification of CPA to mutagenic metabolites (totally dependent on the same preferentially CYP2B-catalyzed 4-hydroxylation of CPA as is the generation of highly cytotoxic…
Early Skin Toxicity as a Predictive Factor for Tumor Control in Hepatocellular Carcinoma Patients Treated with Sorafenib.
2010
Abstract Introduction. Sorafenib is an oral multikinase inhibitor that targets Raf kinase and receptor tyrosine kinases and has led to a longer median overall survival (OS) time and time to progression (TTP) in patients with advanced hepatocellular carcinoma (HCC). This study was conducted to assess the link between the antitumor efficacy of sorafenib and its early cutaneous side effects in advanced HCC patients. Materials and Methods. All patients received 800 mg daily of sorafenib until progression or unacceptable toxicities. We retrospectively analyzed the incidence of rash and hand–foot skin reactions (HFSR) during the first month of treatment, comparing tumor control (partial response …
Trastuzumab therapy vs tetracycline controlled ERBB2 downregulation: influence on tumour development in an ERBB2-dependent mouse tumour model
2008
Trastuzumab (Herceptin) has improved therapy of breast cancer. Only patients overexpressing ERBB2 are treated with trastuzumab, whereas its use in tumours without ERBB2 expression is useless. This led to the concept that the subgroup of trastuzumab-sensitive tumours is ‘ERBB2-dependent', meaning that ERBB2 signalling is indispensable for growth of these tumours. We used a mouse model that allows anhydrotetracycline (ATc)-controlled downregulation of ERBB2 in tumour tissue. ERBB2 mRNA and protein expression were downregulated below detection limit leading to a macroscopically complete tumour remission within 14 days. Tumour remission was accompanied by a strong decrease in proliferation, a m…
Analysis of t(15;17) chromosomal breakpoint sequences in therapy-related versus de novo acute promyelocytic leukemia: Association of DNA breaks with …
2010
We compared genomic breakpoints at the PML and RARA loci in 23 patients with therapy-related acute promyelocytic leukemia (t-APL) and 25 de novo APL cases.Eighteen of 23 t-APL cases received the topoisomerase II poison mitoxantrone for their primary disorder. DNA breaks were clustered in a previously reported 8 bp "hot spot" region of PML corresponding to a preferred site of mitoxantrone-induced DNA topoisomerase II-mediated cleavage in 39% of t-APL occurring in patients exposed to this agent and in none of the cases arising de novo (P = 0.007). As to RARA breakpoints, clustering in a 3' region of intron 2 (region B) was found in 65% of t-APL and 28% of de novo APL patients, respectively. S…
Prostate cancer: from the pathophysiologic implications of some genetic risk factors to translation in personalized cancer treatments.
2013
Several pathologies affect human prostate, such as prostate cancer (PC), which is the most common non-skin malignant cancer in Western male populations. A complex interaction between genetic and environmental factors (i.e. infectious agents, dietary carcinogens) and hormonal imbalances has been reported to have a fundamental role in PC pathophysiology by evoking chronic inflammation. Thus, chronic inflammation drives prostate carcinogenesis and neoplastic progression. No adequate biomarkers exist until now to guide PC prognosis and treatment. Accordingly, the research has particularly focused its attention on genetic variants in genes, codifying molecules of signaling innate immune/inflamma…
Oxidative stress in bisphosphonate-related osteonecrosis of the jaws
2013
Objectives To analyze whether oxidative stress (OS) changes are present in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) versus controls. Materials and Methods Oxidative stress was analyzed in serum and unstimulated saliva of three groups: Group 1 consisted of 24 patients who had been treated with intravenous bisphosphonates (ivBPs) and developed BRONJ, group 2 consisted of 20 patients who had received ivBPs and did not develop BRONJ, and group 3 comprised 17 control subjects. Reduced glutathione (GSH), malondialdehyde (MDA), oxidized glutathione (GSSG), and 8–oxo-7,8-dihydro-2-deoxyguanosine (8-oxo-dG) levels, as well as the GSSG/GSH ratio, were measured. Results Me…
Complete tumor prevention by engineered tumor cell vaccines employing nonviral vectors.
2004
We report that 100% mice survival after tumor challenge is achieved with cytokine-engineered cells employing nonviral lipoplexes and without using viral vectors. We describe this effect with cytokine-secreting tumor cell vaccines, based on cell clones or fresh transfected cells. Tumor cells were transfected with murine granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-4 plasmids employing the cationic lipid DOTAP, were irradiated (150 Gy) and kept frozen until use. The transfection efficacy was analyzed by qRT-PCR and flow cytometry. Vaccination induced potent antitumor rejection, resulting in 100% mice survival. Furthermore, the antitumor immunity was long lasting, since a tw…
ERGO: A pilot study of ketogenic diet in recurrent glioblastoma
2014
Limiting dietary carbohydrates inhibits glioma growth in preclinical models. Therefore, the ERGO trial (NCT00575146) examined feasibility of a ketogenic diet in 20 patients with recurrent glioblastoma. Patients were put on a low-carbohydrate, ketogenic diet containing plant oils. Feasibility was the primary endpoint, secondary endpoints included the percentage of patients reaching urinary ketosis, progression-free survival (PFS) and overall survival. The effects of a ketogenic diet alone or in combination with bevacizumab was also explored in an orthotopic U87MG glioblastoma model in nude mice. Three patients (15%) discontinued the diet for poor tolerability. No serious adverse events attri…
Castration-Induced Downregulation of SPARC in Stromal Cells Drives Neuroendocrine Differentiation of Prostate Cancer.
2021
Abstract Fatal neuroendocrine differentiation (NED) of castration-resistant prostate cancer is a recurrent mechanism of resistance to androgen deprivation therapies (ADT) and antiandrogen receptor pathway inhibitors (ARPI) in patients. The design of effective therapies for neuroendocrine prostate cancer (NEPC) is complicated by limited knowledge of the molecular mechanisms governing NED. The paucity of acquired genomic alterations and the deregulation of epigenetic and transcription factors suggest a potential contribution from the microenvironment. In this context, whether ADT/ARPI induces stromal cells to release NED-promoting molecules and the underlying molecular networks are unestablis…