Huiyun Xu

A randomized controlled trial of Licartin for preventing hepatoma recurrence after liver transplantation.

Orthotopic liver transplantation (OLT) is the only curative therapy of HCC with underlying cirrhosis, but due to HCC metastasis and recurrence, its benefit is limited to a small population who meet the strict selection criteria. We previously reported that Licartin ([131I]mAb HAb18G/CD147) was safe and effective in treating HCC patients, and its antigen, HAb18G/CD147, was closely related to HCC invasion and metastasis. Here, we reported a randomized controlled trial to assess the post‐OLT antirecurrence efficacy of Licartin in advanced HCC patients. We randomized 60 post‐OLT patients with HCC, who were at tumor stage 3/4 and outside the Milan criteria before OLT, into 2 groups. Three weeks after OLT, the treatment group received 15.4 MBq/kg of Licartin, while the control group received placebo intravenously for 3 times with an interval of 28 days. At 1‐year follow‐up, the recurrence rate significantly decreased by 30.4% (P = 0.0174) and the survival rate increased by 20.6% (P = 0.0289) in the treatment group, compared with those in the control group. For the control group versus the treatment group, the hazard ratio for recurrence was 3.60 (95% confidence interval [CI], 1.50‐8.60) and that for death was 3.87 (95% CI, 1.23–12.21). Licartin treatment also resulted in an earlier decreased AFP level and a longer time of normal AFP level than placebo (P = 0.0016). No Licartin‐related toxic effects were observed. Conclusion: Licartin is a promising drug for preventing post‐OLT tumor recurrence in advanced HCC patients excluded by the currently strict criteria for OLT. HAb18G/CD147 can be a good drug target. (HEPATOLOGY 2007;45:269–276.)

HAb18G/CD147 Functions in Invasion and Metastasis of Hepatocellular Carcinoma

CD147 molecule is reported to be correlated with the malignancy of some cancers; however, it remains unclear whether it is involved in the progression of hepatocellular carcinoma (HCC). Here, we investigated the function of HAb18G/CD147, a member of CD147 family, and its antibodies, HAb18 and LICARTIN, in HCC invasion and metastasis. We observed that HAb18G/CD147 gene silence in HCC cells significantly decreased the secretion of matrix metalloproteinase (MMP) and the invasive potential of HCC cells (P < 0.001). MMP silence in HCC cells also significantly suppressed the invasion of the cells when cocultured with fibroblasts; however, its inhibitory effect was significantly weaker than that of both HAb18G/CD147 silence in HCC cells and that of MMP silence in fibroblasts (P < 0.001). Blocking theHAb18G/CD147 molecule on HCC cells with HAb18 monoclonal antibody resulted in a similar suppressive effect on MMP secretion and cell invasion, but with no significant effects on the cell growth. 131I-labeled HAb18 F(ab′)2 (LICARTIN), however, significantly inhibited the in vitro growth of HCC cells (P < 0.001). In an orthotopic model of HCC in nude mice, HAb18 and LICARTIN treatment effectively reduced the tumor growth and metastasis as well as the expression of three major factors in the HCC microenviroment (MMPs, vascular endothelial growth factor, and fibroblast surface protein) in the paracancer tissues. Overall, these results suggest that HAb18G/CD147 plays an important role in HCC invasion and metastasis mainly via modulating fibroblasts, as well as HCC cells themselves to disrupt the HCC microenviroment. LICARTIN can be used as a drug targeting to HAb18G/CD147 in antimetastasis and recurrence therapy of HCC. (Mol Cancer Res 2007;5(6):605–14)

INHIBITORY EFFECTS OF A GRADIENT STATIC MAGNETIC FIELD ON NORMAL ANGIOGENESIS

Angiogenesis, the formation of new blood vessels, is critical in many normal and pathological processes such as development, reproduction, tumor growth, and metastasis. Recently, exposure to moderate-intensity static magnetic fields (1 mT to 1 T) has attracted much attention for its potential therapeutic value as a noninvasive intervening method. Nevertheless, the effects of moderate-intensity and spatial gradient static magnetic fields (GSMF) on angiogenesis have not received enough attention. In this study, the effects of GSMF (0.2-0.4 T, 2.09 T/m, 1-11 days) on angiogenesis were investigated both in vitro and in vivo. An MTT assay was used as an in vitro method to detect the proliferation ability of human umbilical veins endothelial cells (HUVECs). Two kinds of in vivo models, a chick chorioallantoic membrane (CAM) and a matrigel plug, were used to detect the effects of GSMF on angiogenesis. The results showed that the proliferation ability of HUVECs was significantly inhibited 24 h after the onset of exposure. With regard to the CAM model, vascular numbers in the CAM that was continuously exposed to the GSMF were all less than those in normal condition. In accordance with the gross appearance, the contents of hemoglobin in the models exposed to GSMF for 7-9 days were also less. In addition, similar to the CAM model, the results of vascular density and hemoglobin contents in the matrigel plug also demonstrated that the GSMF exposure for 7 or 11 days inhibited vascularization. These findings indicate that GSMF might inhibit or prevent new blood vessels formation and could be helpful for the treatment of some diseases relevant to pathological angiogenesis.

Human mesenchymal stem cells are sensitive to abnormal gravity and exhibit classic apoptotic features

The aim of the present study was to investigate the effects of abnormal gravity on human mesenchymal stem cells (hMSCs). Strong magnetic field and magnetic field gradient generate a magnetic force that can add to or subtract from the gravitational force. In this study, this is defined as a high-magneto-gravitational environment (HMGE). The HMGE provides three apparent gravity levels, i.e. hypogravity (μg), hypergravity (2g) and normal gravity with strong magnetic field (1g) conditions. After hMSCs were subject to HMGE for 12 h, the proliferation, morphology, structure and apoptosis were investigated. Results showed that the proliferation of hMSCs was inhibited under μg condition. The abnormal gravity induced morphologic characteristics of apoptosis cells, such as cell shrinkage, membrane blebbing, nuclear chromatin condensation and margination, decreased cell viability, and increased caspase-3/7 activity. The rate of apoptosis under μg condition is up to 56.95%. The F-actin stress fibers and microtubules were disrupted under abnormal gravity condition. Under μg-condition, the expression of p53 at mRNA and protein levels was up-regulated more than 9- and 6 folds, respectively. The Pifithrin-α, an specific inhibitor of p53, inhibited the apoptosis and prevented the disruption of cytoskeleton induced by abnormal gravity. These results implied that hMSCs were sensitive to abnormal gravity and exhibited classic apoptotic features, which might be associated with p53 signaling.

Oscillatory fluid flow elicits changes in morphology, cytoskeleton and integrin-associated molecules in MLO-Y4 cells, but not in MC3T3-E1 cells

Interstitial fluid flow stress is one of the most important mechanical stimulations of bone cells under physiological conditions. Osteocytes and osteoblasts act as primary mechanosensors within bones, and in vitro are able to respond to fluid shear stress, both morphologically and functionally. However, there is little information about the response of integrin-associated molecules using both osteoblasts and osteocytes. In this study, we investigated the changes in response to 2 hours of oscillatory fluid flow stress in the MLO-Y4 osteocyte-like cell line and the MC3T3-E1 osteoblast-like cell line. MLO-Y4 cells exhibited a significant increase in the expression of integrin-associated molecules, including OPN, CD44, vinculin and integrin αvβ3. However, there was no or limited increase observed in MC3T3-E1 osteoblast-like cells. Cell area and fiber stress formation were also markedly promoted by fluid flow only in MLO-Y4 cells. But the numbers of processes per cell remain unaffected in both cell lines.

Two-dimensional clinorotation influences cellular morphology, cytoskeleton and secretion of MLO-Y4 osteocyte-like cells

The aim of this study was to investigate the effects of the clinostat-simulated weightlessness on biological characteristics of MLO-Y4 osteocyte-like cells. MLO-Y4 cells were incubated for 24 h, then randomly divided into 3 groups and rotated in a clinostat as a model of simulated weightlessness for 12 h, 24 h and 48 h. The morphology, cytoskeleton, and secretion of soluble molecules of MLO-Y4 cells were observed and detected. The results show that clinostat culture affects the number of dendrites/cell, cytoskeleton distribution, and secretion of nitric oxide and prostaglandin E2 in MLO-Y4 cells. These results may provide some clue to explore the cellular mechanism of bone loss caused by weightlessness.

Polycystin 2 is involved in the nitric oxide production in responding to oscillating fluid shear in MLO-Y4 cells.

As a mechano-calcium channel, polycystin2 (PC2) play an important role in the response of renal epithelial cells to fluid flow shear stress. In bone tissue, osteocytes are well known as the main mechanosensory cells, and sensitive to fluid flow stimulus in vitro. In the study, we investigated the effects of oscillating fluid flow (OFF, 2 h, 1 Hz, 1.0 Pa) on the release of Nitric Oxide (NO) and ProstaglandinE2 (PGE2), and the role of PC2 on the release. Our findings demonstrate that PC2 expression increases after 2 h of OFF, and silencing PC2 by RNAi inhibits downstream NO production and iNOS expression, but does not affect the response of PGE2 to OFF.

Hyperoxygenated solutions in clinical practice: preventing or reducing hypoxic injury.

In cases of hypoxia, oxygen can be supplied via a number of methods including face masks, nasal cannulae, hyperoxygenated oxygen chambers and mechanical ventilation. Administering oxygen via the respiratory tract is, however, limited in respiratory diseases such as pulmonary fibrosis, pneumoconiosis and severe acute respiratory syndrome, or following the inhalation of asphyxiating poisons. This has led to research into new methods of supplying oxygen that bypass the lungs. Research has investigated the efficacy of intravenous hyperoxygenated solutions (HOS) as auxiliary oxygen supplies in several hypoxic states including cardiopulmonary resuscitation, respiratory failure, cerebrovascular disease, myocardial ischaemia, severe acute respiratory syndrome, poisoning, neonatal hypoxia, altitude sickness, large burns and traumatic haemorrhagic shock. Much of the research has taken place in China and more than 3.5 million hypoxic patients have received HOS, with good therapeutic effects. This review summarizes the literature supporting the use of this novel treatment.

Biological responses of osteocytic connexin 43 hemichannels to simulated microgravity.

Connexin 43 (Cx43) hemichannels and gap junctions in osteocytes are responsive to mechanical loading, which is important for bone formation and remodeling. However, the mechanism of these Cx43‐forming channels in the process of mechanical unloading is still not very clear. In this study, unloading caused by weightlessness was simulated by using a random position machine (RPM). Osteocytic MLO‐Y4 cells were subjected to 2 h of RPM treatment, and levels of Cx43 mRNA and total and cell surface expressed protein were determined by quantitative real‐time PCR, western blotting, and biotinylation analysis. Although mRNA was elevated by RPM, total protein level of Cx43 was not altered; however, surface biotinylated Cx43 was significantly reduced. Interestingly, RPM promoted the retention of Cx43 in the Golgi apparatus detected by co‐immunofluorescence with antibodies against Cx43 and 58 K Golgi marker protein. Dye uptake assay showed that hemichannels were induced open after RPM for 2 h. Consistently, prostaglandin E2 release was increased and this increase was completely attenuated with the treatment of a Cx43 hemichannel blocking antibody. Together, this study demonstrates increased activity of Cx43 hemichannels to RPM, and active Cx43 hemichannels with prostaglandin E2 release are likely to module biological function under simulated weightless conditions.

Deformation regimes of collagen fibrils in cortical bone revealed by in situ morphology and elastic modulus observations under mechanical loading

The mechanical properties of the bone play a decisive role in the resistance of the bone to fracture. Clinically, the quantity of the bone in the mineral phase has been considered as the gold-standard indicator for the risk of bone fracture. However, the bone is a complex tissue with a hierarchical-structure consisting of organic matrix, mineral hydroxyapatite, and water. Collagen comprises up to 90% of the organic matrix in the bone, and is vital for its mechanical behavior. To date, the morphological and mechanical responses of collagen fibrils in the bone matrix have been largely overlooked. In the present study, an atomic force microscopy-based imaging and indentation approach is introduced and integrated with a tibia axial loading model. The morphology of mineralized Type I collagen fibrils of the murine cortical tibia is imaged after demineralization, and the in situ elastic modulus of the fibrils is quantified at different loading conditions. Results suggested that the mineralized collagen fibrils are stretched in the early phase of bone deformation, characterized by the elongation of the D-periodic spacing. Reorientation of the collagen fibrils is demonstrated in the subsequent phase of bone deformation. The in situ radial elastic modulus of the collagen fibrils remained constant under the tested loading conditions. These experimental findings provide evidence in support of the unique deformation regimes of bone tissue from the perspective of alterations of mineralized collagen fibrils. This study allows the understanding of the unique mechanical behavior of the bone at the nanoscale, and reveals the mechanisms of relevant diseases that impair the mechanical properties of the bone.