Hypoxia is a general characteristic of most solid malignancies and intimately related to cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor-1alpha (HIF-1alpha) that elicits transcriptional activity through recruitment P300 coactivator. Targeting the interaction of HIF- alpha and P300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, a screening assay was developed for inhibitors targeting the interaction between HIF-1alpha and P300. The nucleotide sequence of human HIF-1alpha and P300 were cloned into pBIND and pACT vectors, named pBIND-HIF1alpha and pACT-P300. The interaction of HIF-1alpha and P300 was identified in HEK293 cell using mammalian two-hybrid system. And compound chetomin decreased their interaction in this mammalian two-hybrid system. We further verified HIF-1 inhibition effect of chetomin in U251-HRE cells. Therefore, we established a screening assay combined HIF-1alpha and P300 mammalian two-hybrid system and U251-HRE reporter assay for HIF-1 selective inhibitors.

The purpose of this study is to investigate the activity and mechanism of a new anti-tumor agent T03. MTT and colony formation assay were performed to determine anti-proliferation activity of T03 in vitro. Antitumor activity was observed by Renca xenograft model in vivo. The effect of T03 on cell cycle and apoptosis were measured by FCM analysis. Western blotting was performed to investigate the expression level of proteins in HepG2 cell lines treated with T03. T03 had anti-tumor activity by inhibiting tumor cell growth and colony formation in vitro, especially on hepatocellular carcinoma cells (HCC). At the concentration of 10 micromol x L(-1), T03 induced cell apoptosis and cell cycle arrest in HCC. Moreover, it proved that T03 reduced the tumor weight with the rate of 42.30% without any obviously side effect in Renca xenograft model. At the concentration of 2.0 micromol x L(-1), T03 was able to reduce the level of p-c-Raf (Ser259), and thus blocked Raf/MEK/ERK and AKT signaling in HepG2 cell lines. The result suggested that T03 has the potential to inhibit cell proliferation and induce cell apoptosis both in vitro and in vivo, particularly active against HCC, indicating T03 and its analogues may serve as a new anti-cancer drug against hepatocellular carcinoma.

Objective:To evaluate the role of monocyte-derived macrophages (Mo-Mφ) in postoperative cognitive dysfunction (POCD) induced by cardiopulmonary bypass (CPB) in rats.Methods:Forty SPF healthy adult Sprague-Dawley rats, weighing 350-400 g, aged 11-12 weeks, were divided into 4 groups ( n = 10 each) using a random number table method: sham operation group (S group), CPB group (C group), CPB plus PBS liposome group (P group), and CPB plus clodronate liposome group (L group). In C, P, and L groups, CPB was performed for 60 min, the equal volume of normal saline, PBS liposomes 4 μl/g and clodronate liposomes 4 μl were injected via the tail vein at 48 and 24 h before CPB, respectively.Blood was collected from the saphenous vein before CPB for determination of the clearance rate of Mo-Mφ by flow cytometry.Cognitive function was assessed using the Morris water maze test at 7 days after CPB.Blood was collected from the abdominal aortic vein, and the levels of serum inflammatory factors (interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-α], and interleukin-1beta [IL-1β]) and brain injury markers (S100β protein and neuron-specific enolase [NSE]) were measured by enzyme-linked immunosorbent assay. Results:Compared with group S, the serum IL-1β, IL-6 and TNF-α concentrations were significantly increased, the serum S100β protein and NSE concentrations were increased, the escape latency was prolonged, and the number of crossing the platform was decreased in C, P, and L groups ( P<0.05). Compared with group C, the clearance rate of blood-derived monocytes was significantly decreased, the serum S100β concentrations were increased, the escape latency was prolonged, and the number of crossing the platform was decreased ( P<0.05), and no significant change was found the parameters mentioned above in group P ( P>0.05). Conclusion:Mo-Mφ infiltration is the endogenous protective mechanism of CPB-induced POCD in the rats.