Effect of 5-aminolevulinic acid-mediated photodynamic therapy on human gastric cancer xenografts in nude mice in vivo / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on human gastric cancer xenografts in vivo and to explore its potential tumoricidal mechanism.</p><p><b>METHODS</b>Cultured MGC-803 human gastric cancer cells were injected below the skins of the nude mice to develop the tumor model. The tumor-bearing nude mice were examined under the Leica LT-9 MACIMSYSPULS to detect the fluorescence. The tumor volume of day 1, 3, 7, 14, 21 after treatment were measured, and its histological changes were also studied. The tissues of the tumors in nude mice of the control group, light group, 5-ALA group and PDT group were examined with the electron microscope and apoptosis was detected by TUNEL assay.</p><p><b>RESULTS</b>The tumor model was successfully developed. The tumor in the nude mice emitted the red fluorescence under the Leica LT-9 MACIMSYSPULS. The tumor volumes were (0.189+/-0.010) cm(3), (0.183+/-0.011) cm(3), (0.185+/-0.019)cm(3), (0.182+/-0.015)cm(3) for the control group, light group, 5-ALA group, PDT group, respectively at day 1 after treatment, while at day 3, (0.294+/-0.010) cm(3), (0.280+/-0.013) cm(3), (0.278+/-0.016) cm(3), (0.183+/-0.014) cm(3); at day 7, (0.409+/-0.016) cm(3), (0.411+/-0.009) cm(3), (0.407+/-0.015) cm(3), (0.221+/-0.008) cm(3); at day 14, (0.970+/-0.055) cm(3), (0.976+/-0.054) cm(3), (0.981+/-0.032)cm(3), (0.318+/-0.005) cm(3); at day 21, (1.495+/-0.059) cm(3), (1.513+/-0.057) cm(3), (1.524+/-0.063) cm(3), (0.446+/-0.042) cm(3) (F=1003.086, P=0.000). The histology demonstrated that most tumor blood vessels were congested and necrosis developed after PDT while not in the control group, light group and 5-ALA group. Necrosis and apoptosis were observed in the cells of the tumors of the PDT group examined by TUNEL and electron microscope while not in the cells of the tumors of the other groups.</p><p><b>CONCLUSIONS</b>5-aminolevulinic acid-mediated photodynamic therapy (PDT) can induce injury to human gastric cancer xenografts and inhibit the tumor growth while light only and 5-ALA only can not. 5-aminolevulinic acid-mediated photodynamic therapy (ALA- PDT) appears to be a promising therapy for human gastric cancer, whose mechanism involves in the destruction of the tumors partly by apoptosis other than necrosis.</p>

Phase IIa clinical trail of hemocoagulase acutus for injection / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of hemocoagulase acutus for injection and determine its curative dose.</p><p><b>METHODS</b>Forty-five patients on abdominal surgeries were randomly allocated into 2 study groups and 1 control group. Thirty minutes before the operation, the patients in the study groups received intravenous hemocoagulase acutus at 1 U and 2 U, respectively, and control group had no treatment. The hemostatic time, hemorrhagic volume, and hemoagglutination were observed in all the groups.</p><p><b>RESULTS</b>The average hemorrhagic volume and hemorrhagic volume per square were significantly lower in the two study groups than in the control group (P<0.05), and the average hemorrhagic volume per square were significantly lower in study group 2 U than in the 1 U group (P<0.05). No significant differences were found in adverse effects between the 3 groups.</p><p><b>CONCLUSION</b>Hemocoagulase acutus for injection has good hemostatic effect for controlling capillary hemorrhage at the abdominal incisions and can be safely used in the surgical patients.</p>

In vitro killing effect of adenovirus-mediated fusion gene system driven by KDR promoter on gastric cancer cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the killing effect of adenovirus(Ad)-mediated double suicide gene driven by kinase domain-containing receptor (KDR) promoter on gastric cancer MGC-803 cells.</p><p><b>METHODS</b>The 293 packaging cells were transfected by the plasmids pAdEasy-KDR-CDglyTK to generate infectious viruses. The gastric cancer MGC-803 cells were infected by the Ad followed by treatment with 5-FC and/or ganciclovir at different concentrations. The cell-killing effects were evaluated and the bystander effects analyzed after coculture of the cells without AdKDR-CDglyTK infection with the infected cells at different ratios. The cell cycle distribution was detected by flow cytometry and the pathological changes of the cells were observed by electron microscopy.</p><p><b>RESULTS</b>The infection rate of the resultant recombinant Ad in the cells increased gradually with increment of the multiplicity of infection (MOI) of the Ads. The killing effect of CD/TK fusion gene on the MGC-803 cells was much stronger than that of either of the single suicide gene (P<0.001), and considerable bystander effect was observed. The Ad infection caused MGC-803 cell growth arrest at G(1) phase with onset of apoptotic and necrotic morphologies of the cells as seen under electron microscope.</p><p><b>CONCLUSION</b>The CD/TK fusion gene system driven by the KDR promoter possesses effective killing effect on the KDR-expressing gastric cancer MGC-803 cells.</p>

Effect of photodynamic therapy with 5-aminolevulinic acid on human gastric cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy (PDT) on MGC-803 human gastric cancer cells in vitro.</p><p><b>METHODS</b>MGC-803 human gastric cancer cells were treated with 5-ALA at various concentrations followed by laser irradiation. The cells were also treated with 5-ALA at the same concentration before laser exposure at various doses. PDT-induced phototoxicity of the cells was determined by MTT assay.</p><p><b>RESULTS</b>After laser exposure of the cells at the same dose (25.0 J/cm(2)), the cell survival rates decreased significantly with incubation of the cells with 5-ALA at 0.25, 0.5, 1.0, 2.0 and 4.0 mmol/L, respectively (F=266.39, P<0.001), but 2.0 and 4.0 mmol/L ALA showed no significant difference in lowering the cell survival rates (P>0.05). Following treatment with the same 5-ALA concentration (1 mmol/L), the cell survival rates decreased in response to increased laser doses (at 6.25, 12.5, 25.0, 50.0, and 100 J/cm(2), respectively, F=226.31, P<0.0001). Without laser exposure, the survival rate of the cells did not significantly change for different 5-ALA concentrations (F=0.79, P=0.5383), nor did it undergo obvious variation in response to different laser doses without 5-ALA incubation (F=0.61, P=0.6551).</p><p><b>CONCLUSIONS</b>The damage of MGC-803 cells by PDT increases with 5-ALA concentration within a relative lower range and is proportional to the laser doses delivered. Without 5-ALA treatment, the laser at the chosen dose cannot produce photodynamic effect and ALA itself is nontoxic. ALA-mediated PDT appears to be a promising therapy for gastric cancer.</p>