Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study using a transplantable murine T cell lymphoma designated as Dalton's lymphoma, we investigated the role of oxygen, glucose and other environmental factors in evolution of altered survival responses in tumor cells during the late tumor-bearing stages. Tumor progression was observed to be associated with an improvement in the survival ability of tumor cells. Moreover, tumor serum and ascitic fluid obtained from the late tumor bearing stage was found to augment tumor cell survival in vitro, indicating that these humoral components of tumor bearing host contain factors capable of modulating tumor survival. Progressive tumor growth was also shown to be associated with depletion in glucose and oxygen content in the fluids of tumor microenvironment along with a concomitant augmentation in the production of lactate and lactate dehydrogenase. Moreover, tumor cells expressed higher amount of mRNA for inducible nitric oxide synthase, Hypoxia inducible factor-1 and 2 and Hsp70 and VEGF proteins during the late tumor bearing stages. Splenic macrophages and non-adherent splenic lymphocytes from tumor-bearing mice showed an increased production of IL-6, TGF-beta, IFN-gamma, IL-2R and VEGF during the late tumor-bearing stage, which could be implicated in the differential regulation of tumor growth in a tumor stage dependent manner. In conclusion, the observations of the present study suggest that factors contained in altered tumor microenvironment may act in concert to cause behavioral alterations in tumor cells, with respect to survival, during the course of the progression of a nonsolid T cell lymphoma.
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PMID:Progressive tumor growth-associated altered tumor microenvironment: implications in a tumor stage-dependent modulation in survival of a murine T cell lymphoma. 1912 95

In this review, we discuss the concept of metabolic remodeling and signaling in tumors, specifically the various metabolites that participate in the regulation of gene expression in cancer cells. In particular, pyruvate, oxaloacetate, succinate and fumarate, four mitochondrial metabolites, activate genes relevant for tumor progression. When the balance between glycolysis and oxidative phosphorylation is altered, these metabolites accumulate in the cytoplasm and regulate the activity of the Hypoxia Inducible Factor 1alpha (HIF-1alpha). HIF is one of the main factors that orchestrate the metabolic switch observed during oncogenesis. There is also an important role for lactate, fructose 1-6 bisphosphate or citrate that leads to the diversion of glucose metabolites to anabolism. In addition reactive oxygen species, which are produced by the respiratory chain, could serve as an endogenous source of DNA-damaging agents to promote genetic instability. Accordingly, several mitochondrial DNA mutations were reported in tumors, and the construction of cybrids recently demonstrated their role in the control of tumor progression.
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PMID:Mitochondria: from bioenergetics to the metabolic regulation of carcinogenesis. 1927 31

A shift in glucose metabolism from oxidative phosphorylation to glycolysis is one of the biochemical hallmarks of tumor cells. Mitochondrial defects have been proposed to play an important role in the initiation and/or progression of various types of cancer. In the past decade, a wide spectrum of mutations and depletion of mtDNA have been identified in human cancers. Moreover, it has been demonstrated that activation of oncogenes or mutation of tumor suppressor genes, such as p53, can lead to the upregulation of glycolytic enzymes or inhibition of the biogenesis or assembly of respiratory enzyme complexes such as cytochrome c oxidase. These findings may explain, at least in part, the well documented phenomena of elevated glucose uptake and mitochondrial defects in cancers. In this article, we review the somatic mtDNA alterations with clinicopathological correlations in human cancers, and their potential roles in tumorigenesis, cancer progression, and metastasis. The signaling pathways involved in the shift from aerobic metabolism to glycolysis in human cancers are also discussed.
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PMID:Mitochondrial DNA instability and metabolic shift in human cancers. 1933 28

Cancer cells, as with most mammalian cells, depend on a continuous supply of glucose; not only as a precursor of glycoproteins, triglycerides and glycogen, but also as an important source of energy. This review concentrates on GLUT transporter expression in both normal and cancerous classical sex-steroid hormone tissues (i.e. breast, uterus, ovary, testis and prostate, among others). Given the importance of estrogen, progesterone and androgens in carcinogenesis, as well as in survival and propagation of these cancers, this review also highlights the current literature on hormone regulation of glucose transporters and on the role of hypoxia in their expression. Given the recent explosion of information on the newer GLUT6-12 family members, a brief overview on their function and general expression has been included. Finally, an insight into the use of glucose transporters as markers of cancer progression and clinical outcome is also discussed.
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PMID:Glucose transporters in sex steroid hormone related cancer. 1948 86

A number of recent observations have suggested a potential role for membrane-bound gamma-glutamyltransferase (GGT) in tumor progression and appearance of more aggressive and resistant phenotypes, through redox interactions leading to production of reactive oxygen species. The present study was aimed to evaluate whether such pro-oxidant activity of GGT can promote oxidative DNA damage, thus contributing to cancer genomic instability. Human GGT-transfected melanoma cells were studied, and DNA damage was measured by using the alkaline comet assay. Our results indicate that higher levels of GGT activity are associated with higher levels of background DNA damage and oxidized bases. This association cannot be explained by differences in cell cycle distribution or apoptotic rates. GGT-over-expressing cells also presented with a markedly higher glucose uptake, a phenomenon potentially leading to higher metabolic rate and oxidative DNA damage. Anyway, when GGT-over-expressing cells were incubated in the presence of GGT substrates and a source of catalytic iron, increased levels of DNA damage and oxidized bases were observed, an effect completely prevented in the presence of GGT inhibitors or various antioxidants.The findings reported indicate that GGT activity is able to promote iron-dependent DNA oxidative damage, thus potentially representing an important mechanism in initiation/progression of neoplastic transformation.
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PMID:Membrane gamma-glutamyl transferase activity promotes iron-dependent oxidative DNA damage in melanoma cells. 1950 83

PED/PEA-15 is a 15-kDa ubiquitously expressed protein implicated in a number of fundamental cellular functions, including apoptosis, proliferation, and glucose metabolism. PED/PEA-15 lacks enzymatic function and serves mainly as a molecular adaptor. PED/PEA-15 is an endogenous substrate for protein kinase C (PKC), calcium/calmodulin-dependent protein kinase II (CAM kinase II), and Akt. In particular, PKC phosphorylates PED/PEA-15 at Ser(104) and CAM kinase II or Akt at Ser(116), modifying its stability. Evidence obtained over the past 10 years has indicated that PED/PEA-15 regulates cell survival by interfering with both intrinsic and extrinsic apoptotic pathways. In addition, it may also control cell proliferation by interfering with ERK1/2-mediated pathways. Indeed, PED/PEA-15 has been identified as an ERK1/2 interactor, which modifies its subcellular localization and targeting to a specific subset of substrates. Increased PED/PEA-15 levels may affect tumorigenesis and cancer progression as well as sensitivity to anticancer agents. Moreover, PED/PEA-15 affects astrocyte motility and increases susceptibility to skin carcinogenesis in vivo. PED/PEA-15 expression is regulated at the transcriptional and the posttranslational levels. Increased PED/PEA-15 expression has been identified in individuals with type 2 diabetes early during the natural history of the disease. Evidence generated over the past 10 years indicated that this defect contributes to altering glucose tolerance by impairing insulin action and insulin secretion and might play a role in the development of diabetes-associated neurological disorders. Strategies are being devised to target key signaling events in PED/PEA-15 action aimed at improving glucose tolerance and at facilitating cancer cell death.
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PMID:Frontiers: PED/PEA-15, a multifunctional protein controlling cell survival and glucose metabolism. 1953 39

Tumor progression is driven by genetic mutations, but little is known about the environmental conditions that select for these mutations. Studying the transcriptomes of paired colorectal cancer cell lines that differed only in the mutational status of their KRAS or BRAF genes, we found that GLUT1, encoding glucose transporter-1, was one of three genes consistently up-regulated in cells with KRAS or BRAF mutations. The mutant cells exhibited enhanced glucose uptake and glycolysis and survived in low-glucose conditions, phenotypes that all required GLUT1 expression. In contrast, when cells with wild-type KRAS alleles were subjected to a low-glucose environment, very few cells survived. Most surviving cells expressed high levels of GLUT1, and 4% of these survivors had acquired KRAS mutations not present in their parents. The glycolysis inhibitor 3-bromopyruvate preferentially suppressed the growth of cells with KRAS or BRAF mutations. Together, these data suggest that glucose deprivation can drive the acquisition of KRAS pathway mutations in human tumors.
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PMID:Glucose deprivation contributes to the development of KRAS pathway mutations in tumor cells. 1966 83

Hypoxia-inducible transcription factor (HIF) is the master regulator of hypoxia-inducible genes involved in the mediation of survival and adaptive responses to insufficient oxygen availability, such as genes involved in hematopoesis, angiogenesis, iron transport, glucose utilization, resistance to oxidative stress, cell proliferation, survival and apoptosis, extracellular matrix homeostasis, and tumor progression. The stability of the HIFalpha subunit is regulated by oxygen-dependent prolyl 4-hydroxylation catalyzed by the HIF prolyl 4-hydroxylases (P4Hs). The 4-hydroxyproline residues generated in normoxic conditions facilitate binding of HIFalpha to the von Hippel-Lindau E3 ubiquitin ligase complex resulting in the attachment of ubiquitin molecules and subsequent rapid proteasomal degradation of HIFalpha. In hypoxia this oxygen-requiring hydroxylation event is inhibited, HIFalpha escapes degradation and can translocate to the nucleus and form a functional dimer with HIFbeta that triggers the hypoxic response. HIF-P4Hs are considered as promising drug development targets in the treatment of diseases such as myocardial infarction, stroke, peripheral vascular disease, inflammation, diabetes and severe anemias. Studies with HIF-P4H inhibitors in various animal models and ongoing clinical trials support this hypothesis by demonstrating efficacy in many applications.
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PMID:HIF prolyl 4-hydroxylases and their potential as drug targets. 1967 Oct 43

Pivotal studies have demonstrated that pharmacotherapy with pegvisomant (Somavert) is a highly effective treatment for acromegaly. Since clinical experience with the drug was very limited, the Pegvisomant Observational Study was launched in Germany immediately with the drug becoming commercially available to patients early in 2004. Its purpose was to record safety and efficacy data on as many patients as possible. As of 12th August 2008 a total of 371 patients (185 males, 186 females) had been included in the study. They were on pegvisomant therapy for an average of 118 weeks. Median and mean doses of pegvisomant were 15 and 16.4 mg/day respectively. Treatment efficacy was monitored by IGF1 levels and the patients symptoms were evaluated by completion of a questionnaire (patient-assessed acromegaly symptom questionnaire). Safety data included liver function tests, fasting glucose, HbA1c measurements, and tumor size monitoring by repeated magnetic resonance imaging. Normalization of IGF1 ranged from 55.7% of the 273 patients assessed after 6 months to 71.3% of 202 patients assessed after 24 months of treatment. It was 70.7% after 36 months (133 patients), 64.8% at 48 months (71 patients), and 58.4% after 60 months (24 patients). In 39 patients (10.9%) treatment was discontinued due to serious adverse events or adverse events with 25 (6.7%) of these patients having a potential causal relationship with the pegvisomant treatment. Liver function tests became abnormal in 20 patients and another three patients were recorded to have hepatobiliary disorders. Tumor size increase was reported in 20 patients, but only confirmed in nine patients by careful revision of all available images. Local injection site reactions were observed in 12 patients. In conclusion, in this large group of pegvisomant-treated patients, long-term data for up to 5 years of treatment are now available. In 71.3% of patients with previously not sufficiently treatable acromegaly, IGF1 levels were normalized by pegvisomant therapy. Elevated transaminases usually normalized after discontinuation but in half of the affected patients also despite continuation of treatment without dose alteration. Tumor progression was a rare event. It did not exceed the expected rate in patients with acromegaly not treated with pegvisomant. As from this presently largest database of acromegalic patients treated with pegvisomant, long-term results are encouraging. The German data are now merged into the global ACROSTUDY and will constitute a major portion of the international ACROSTUDY project as a continuing global web-based observational study.
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PMID:The German ACROSTUDY: past and present. 1968 61

Tumor progression and metastasis depend on the ability of cancer cells to initiate angiogenesis to ensure delivery of oxygen, nutrients, and growth factors to tumor cells and provide access to the systemic circulation. Hypoxia-inducible factor-1 (HIF-1) can activate expression of a broad range of genes that mediate many of the adaptive responses to decreased oxygen concentration, such as enhanced glucose uptake and formation of new blood vessels. Acting through Plexin-B1 on endothelial cells, Semaphorin 4D (Sema4D) has been shown to promote angiogenesis and enhance invasive growth and proliferation in some tumors. Here we show that the gene for Sema4D, the product of which is elevated in head and neck squamous cell carcinoma (HNSCC) cells, contains upstream hypoxia response elements (HRE) and is strongly induced in hypoxia in a HIF-1-dependent manner. Knocking down Sema4D expression with short hairpin (sh) RNA reduces in vitro endothelial cell migration and growth and vascularity of HNSCC xenografts expressing a degradation resistant HIF-1alpha subunit. We also demonstrate a correlation between HIF-1 activity and Sema4D expression in HNSCC specimens. These findings indicate that Sema4D is induced by hypoxia in a HIF-1-dependent manner and influences endothelial cell migration and tumor vascularity. Expression of Sema4D may be a strategy by which carcinomas promote angiogenesis and therefore could represent a therapeutic target for these malignancies.
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PMID:Hypoxia-inducible factor-1-mediated regulation of semaphorin 4D affects tumor growth and vascularity. 1976 74


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