The basic approach to target vascular endothelial growth factor (VEGF) expression in liver cancer under hypoxic condition.

虽然血管内皮生长因子（VEGF）在富血管肿瘤的生长中起作用，但其受体在血管内皮细胞上表达的旁分泌调节机制仍不清楚。本研究旨在探讨低氧暴露的HepG 2细胞释放的VEGF是否改变人脐静脉内皮细胞（HUVECs）中两种不同受体KDR和fit-1的表达。HepG 2细胞在20%O2或1%O2中培养16小时，以检测VEGF mRNA及其蛋白表达的诱导。在常氧条件下，HepG 2细胞条件培养液（CM）刺激HUVECs，RT-PCR检测VEGF受体mRNA的表达，发现低氧刺激可诱导HepG 2细胞VEGF mRNA的表达和VEGF的释放，低氧CM可诱导HUVECs fit-1 mRNA的表达，但对KOR mRNA的表达无明显影响。当缺氧暴露的HepG 2细胞释放VEGF被其反义寡核苷酸阻断时， 关于我们 缺氧-CM引起的内皮fit-1 mRNA上调仍得以维持。这些结果表明，低氧暴露的肝癌细胞不仅可以产生VEGF，而且可以通过非VEGF依赖的机制旁分泌诱导fit-1的表达，经导管肝动脉栓塞术（TAE）是治疗肝细胞癌（HGC）的低氧挑战之一。因此，我们检测了在治疗过程中接受TAE的HCC患者血清中的VEGE水平。方法. 38例HCC和丙型肝炎病毒阳性肝硬化患者进行了研究。在知情同意的情况下，在TAE前和TAE后1、3、7天采集外周血样本。检测血清VEGF和肝细胞生长因子（HGF）水平。检测血清支链氨基酸（BCAA）与酪氨酸（Tyr）的摩尔比（BTR），血清谷草转氨酶（AST）、谷丙转氨酶（ALT）和乳酸脱氢酶（LDH）水平。结果TAE后1天内AST、ALT和LDH水平达到峰值，但7天后VEGF水平明显升高。TAE过程中HGF和BTR水平无明显变化，TAE前HGF和VEGF水平显著相关，TAE后二者无显著相关性，提示VEGF可能是临床低氧干预（TAE）的反应性产物，与HGF或氨基酸代谢无关。VEGF可作为肝肿瘤缺血的敏感标志物。少

Although vascular endothelial growth factor (VEGF) plays a role in growth of hypervascular tumors, mechanisms for paracrine regulation of its receptor expression on vascular endothelial cells remain unknown. This study aimed to investigate whether VEGF released from hypoxia-exposed HepG2 cells alter expression of two distinct receptors, KDR and fit-1, *n human umbilical venous endothelial cells (HUVECs). HepG2 cells Were cultured in 20% 02 or 1% 02 for 16 hours in order to examine induction of VEGF mRNA and its protein expression. Conditioned media of HepG2 cells (CM) were applied to HUVECs under normoxic conditions, and expression of mRNA for the VEGE receptors was determined by RT-PCR.In response to the hypoxic challenge, HepG2 cells upregulated VEGF mRNA and the release of VEGE.The hypoxia-CM stimulated preferentially the mRNA expression of fit-1, but not that of KOR in HUVECs. When the VEGF release from hypoxia-exposed HepG2 cells was blocked by its antisense-oligodeoxynucleotide, … More the endothelial fit-1 mRNA upregulation elicited by the hypoxia-CM was still maintained. These results suggest that hypoxia-exposed hepatic cancer cells can not only produce VEGF but also evolve paracrine induction of fit-1 through VEGE-independent mechanisms.Transcatheter hepatic arterial embolization (TAE) therapy is one of the hypoxic challenge to hepatocellular carcinoma (HGC). Therefore, we examined the level of VEGE in sera of patients with HCC who underwent TAE during the course of the treatment. Methods. Thirty eight patients with HCC and hepatitis C virus-positive cirrhosis were studied. Peripheral blood samples were taken before and 1, 3 7 days after TAE with informed consent. The serum levels of VEGF as well as hepatocyte growth factor (HGF), another hepatic remodeling factor, were measured. The molar ratio (BTR) of serum branched chain amino acid (BCAA) to tyrosine (Tyr), the serum levels of AST, ALT and LDH were also examined. Results. Although the level of AST, ALT and LDH *ched to the peak value within 1 day after TAE, VEGF increased significantly 7 days later. On the other hand, there were no significant alterations in the levels of HGF and BTR during the course of TAE.Although the level of HGF was significantly correlated with the level of VEGF before TAE, no remarkable correlation was observed after TAE.These data collectively suggest that VEGF may be secreted in response to clinical hypoxic intervention, TAE, independent of HGF or the condition of amino acid metabolism. VEGF may play a role as a sensitive marker for hepatic tumor ischemia. Less