Proces angiogeneze je zásadní v růstu a metastazování maligních nádorů a možnosti jeho ovlivnění jsou již několik let v popředí zájmu v onkologii. V současnosti jsou již v klinické praxi dostupná léčiva cílená na proces angiogeneze, která prokázala svůj přínos v řadě klinických studií, i když výzkum přináší stále nové detailní poznatky. Humanizovaná monoklonální protilátka proti VEGF bevacizumab je v léčbě solidních nádorů z těchto léků zatím nejúspěšnější a již patří do standardní léčby metastatického karcinomu kolorekta a nachází uplatnění v léčbě karcinomu prsu, ledvin a plic. Probíhají četné studie zkoumající uplatnění bevacizumabu u jiných solidních malignit. Nežádoucí účinky jsou dobře známy a jejich profil je poměrně příznivý. Článek přináší základní přehled o postavení bevacizumabu v léčbě zmíněných malignit a výsledků klinických studií., Angiogenesis is a key process in growth and metastatic spread of malignant tumors. Enthusiastic research over past years has produced several therapeutic agents targeting angiogenesis, available in clinical practice. The most advanced in the treatment of solid tumors at present time is bevacizumab, a humanized monoclonal anti-VEGF antibody. It has become a part of standard treatment of metastatic colorectal cancer and is settling in the treatment of breast, kidney and lung cancers. To determine the role of bevacizumab in the treatment of other solid malignancies, there are many clinical trials ongoing. The toxicity profile has been well described and is quite favorable. The article brings a basic overview of the clinical use of bevacizumab based on clinical studies., Jiří Tomášek, Štěpán Tuček, and Lit.: 22
Karcinom ledviny se liší od ostatních nádorů v mnoha aspektech svým biologickým chováním, s čímž pak také souvisí odlišný terapeutický přístup. Vzhledem k chemorezistenci má v systémové terapii karcinomu ledviny hlavní místo cílená léčba, působící především na vaskulární endoteliální růstový faktor, který hraje klíčovou roli v etiopatogenezi a progresi nádorů ledvin., Renal cancer differs from other tumours by its biological behaviour, having an impact on its therapeutic approach. Due to chemoresistance, targeted therapy plays a major role in the treatment of renal carcinoma, targeting mainly vascular endothelial growth factor, a keystone in renal carcinoma etiopathogenesis and progression., Hana Procházková-Študentová, Bohuslav Melichar, and Lit.: 32
Diabetic macular edema (DME) is a major factor contributing to visual disabilities in diabetic patients, and the number of patients is increasing. Animal models play a key role in the development of novel therapies. In this study, pathophysiological analyses of ocular lesions in Spontaneously Diabetic Torii (SDT) fatty rats were performed. First, vascular endothelial growth factor (VEGF) concentrations in vitreous humor, retinal vascular permeability and retinal thickness were measured in SDT fatty rats (Experiment 1). Furthermore, the pharmacological effects of two anti-diabetic drugs, phlorizin and pioglitazone, on retinal lesions were evaluated (Experiment 2). As results, the SDT fatty rats exhibited VEGF increase in vitreous humor at 8 and 16 weeks of age, and both retinal vascular hyperpermeability and retinal thickening at 16 weeks of age. In particular, the layers between the retinal internal limiting membrane and the outer nuclear layer were thickened. Phlorizin treatment from 4 to 16 weeks of age improved hyperglycemia and normalized retinal thickness; however, the effect of pioglitazone on retinal thickness was not strong despite the normalization of hyperglycemia. These data demonstrate that the male SDT fatty rat is a useful model for developing new therapeutic approaches in DME., Y. Motohashi, Y. Kemmochi, T. Maekawa, H. Tadaki, T. Sasase, Y. Tanaka, A. Kakehashi, T. Yamada, T. Ohta., and Obsahuje bibliografii
Hypoxia-inducible factor-1α (HIF-1α) transcriptionally regulates expression of several target genes in protecting tissues against hypoxia. With hypoxic stress, vascular endothelial growth factor (VEGF) is a signal protein produced by cells and further contributes to improvement of vascular functions and restoring the oxygen supply to tissues. In this current study, we first hypothesized that the protein levels of HIF-1α and VEGF are reduced in skeletal muscles of plateau animals [China Qinghai- Tibetan plateau pikas (ochotona curzoniae)] in response to hypoxia as compared with control animals [normal lowland Sprague-Dawley (SD) rats]. We further hypothesized that HIF-1α plays a role in regulating expression of VEGF in skeletal muscle. Note that HIF-1α and VEGF were determined by using two-site immunoenzymatic assay (ELISA) methods. Our results demonstrated that hypoxic stress induced by exposure of lower O2 (6 h) significantly increased the levels of HIF-1α and VEGF in the oxidative and glycolytic muscles of SD rats and pikas (P<0.05 vs. normoxic conditions). Notably, the increases in HIF-1α and VEGF were significantly less in pikas (P<0.05, vs. SD controls) than in SD rats. In addition, a linear relationship was observed between amplified HIF-1α and VEGF in oxidative muscle (r=0.76 and P<0.01) and glycolytic muscle (r=0.72 and P<0.01) and inhibiting HIF-1α significantly decreased expression of VEGF induced by hypoxic stress in skeletal muscles (P<0.05). Overall, our findings suggest that (1) responsiveness of HIF-1α and VEGF in skeletal muscles to hypoxic stress is blunted in plateau animals, and (2) HIF-1α has a regulatory effect on VEGF under hypoxic environment., H.-C. Xie, J.-P. He, J.-F. Zhu, J.-G. Li., and Obsahuje bibliografii
Hypoxia training can improve endurance performance. However, the specific benefits mechanism of hypoxia training is controversial, and there are just a few studies on the peripheral adaptation to hypoxia training. The main objective of this study was to observe the effects of hypoxia training on cutaneous blood flow (CBF), hypoxia-inducible factor (HIF), nitric oxide (NO), and vascular endothelial growth factor (VEGF). Twenty rowers were divided into two groups for four weeks of training, either hypoxia training (Living High, Exercise High and Training Low, HHL) or normoxia training (NOM). We tested cutaneous microcirculation by laser Doppler flowmeter and blood serum parameters by ELISA. HHL group improved the VO2peak and power at blood lactic acid of 4 mmol/l (P4) significantly. The CBF and the concentration of moving blood cells (CMBC) in the forearm of individuals in the HHL group increased significantly at the first week. The HIF level of the individuals in the HHL group increased at the fourth week. The NO of HHL group increased significantly at the fourth week. In collusion, four weeks of HHL training resulted in increased forearm cutaneous blood flow and transcutaneous oxygen pressure. HHL increases rowers’ NO and VEGF, which may be the mechanism of increased blood flow. The increased of CBF seems to be related with improving performance.
Vascular endothelial growth factor (VEGF), a disulphide-linked homodimeric glycoprotein that is selectively mitogenic for endothelial cells, plays an important role in vasculogenesis and angiogenesis. Preeclampsia, a relatively common complication of pregnancy that is characterized by diffuse endothelial dysfunction possibly secondary to impaired trophoblast invasion of the spiral arteries during implantation, has recently been associated with alterations in maternal serum/plasma concentrations of VEGF, and other related growth factors and their receptors. We examined the relationship of maternal plasma VEGF, sVEGF-R1 and PlGF levels to the risk of preeclampsia among women delivering at Harare Maternity Hospital, Zimbabwe. 131 pregnant women with preeclampsia and 175 controls were included in a case-control study. Maternal plasma concentrations of each biomarker were measured using enzymatic methods. We used logistic regression to calculate odds ratios (OR) and 95 % confidence intervals (CI). Preeclampsia risk was inversely related with quartiles of plasma VEGF (OR: 1.0, 1.0, 0.7, and 0.5, with the lowest quartile as reference; p for trend = 0.06). We noted a strong positive association between preeclampsia risk and sVEGF-R1 concentrations (OR: 1.0, 6.5, 9.7, 31.6, with the first quartile as the referent group; p for trend < 0.001). After adjusting for confounders, we noted that women with sVEGF-R1 concentrations in the highest quartile (≥ 496 pg/ml), as compared with those in the lowest quartile (< 62 pg/ml) had a 31.6-fold increased risk of preeclampsia (OR = 31.6, 95 % CI 7.7-128.9). There was no clear evidence of a linear relation in risk of preeclampsia with PlGF concentrations. In conclusion, plasma VEGF, sVEGF-R1 and PlGF concentrations (measured at delivery) were altered among Zimbabwean women with preeclampsia as compared with normotensive women. Our results are consistent with some, though not all, previous reports. Prospective studies are needed to: 1) identify modifiable determinants of maternal plasma concentrations VEGF, sVEGF-R1, and PlGF; and 2) evaluate the temporal relationship between observed alterations of these biological markers in preeclamptic pregnancies.