Structural changes of gut microbiota after gastric bypass in obese patients with type 2 diabetes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the structural changes inintestinal flora and metabolic changes in type 2 diabetic patients with obesity(BMI≥40 kg/m)by sequencing the 16S rRNA genes.</p><p><b>METHODS</b>Stool samples were collected from 4 diabetic patients before and after gastric bypass surgery for extraction of the total DNA. The diversity of the intestinal flora in the samples was investigated by 16S rRNA sequencing. After surgery, the changes in glucose and lipid metabolism were evaluated in the patients, and the changesin body mass index (BMI) and waist to hip ratio were assessed at 3 month intervals.</p><p><b>RESULTS</b>After gastric bypass, the patient's BMI, waist to hip ratio, glucose metabolism and lipid metabolism gradually recovered the normal levels. The proportion of Bacteroidetesis increased and the proportions of Firmicutes and Proteobacteria decreased in the intestinal bacteria after the surgery.</p><p><b>CONCLUSION</b>Gastric bypass surgery can effectively alleviate the condition of obese patients with type 2 diabetes and improve the composition of the intestinal flora.</p>

Efficacy of three-dimensional laparoscopic total thyroidectomy combined with central lymph node dissection for thyroid cancer and its effect on inflammatory responses of the patients / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the effect of three-dimensional (3D) laparoscopic total thyroidectomy combined with central lymph node dissection for thyroid cancer and its effect on the inflammatory response of the patients.</p><p><b>METHODS</b>The clinical data were analyzed in 90 patients with thyroid cancer undergoing radical thyroidectomy at our hospital between September, 2013 to April, 2016, including 30 receiving 3D laparoscopic surgeries, 30 with 2D laparoscopic surgeries and 30 with open surgeries. The surgical data, postoperative adverse reactions and the impact of the surgeries on the inflammatory responses of the patients were compared among the 3 groups.</p><p><b>RESULTS</b>Compared with the open surgery and 2D laparoscopic surgery, 3D laparoscopic surgery was associated with lowered blood loss during the surgery and a lowered incidence of adverse reactions. The operation time in 3D group was significantly shorter than that in 2D group (P<0.05), but the total hospitalization expenses were similar between the two groups. The postoperative drainage volume did not differ significantly between the 3D group and the other two groups. The postoperative hospital stay, number of lymph nodes dissected, positivity rate of lymph nodes and the inflammatory response showed no significant differences among the 3 groups (P>0.05).</p><p><b>CONCLUSION</b>3D laparoscopic total thyroidectomy combined with central lymph node dissection is safe and effective and reduces intraoperative blood loss and perioperative adverse reactions without significant influence on inflammatory response in patients with thyroid cancer.</p>

Colonic sac duct for first-stage repair of colon anastomotic leakage in miniature pigs / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the efficacy, safety and reliability of colonic sac duct for first-stage repair of colorectal anastomotic leakage.</p><p><b>METHODS</b>An animal model of colon anastomotic leakage was established in 30 Tibet miniature pigs, which were randomly divided into treatment group and control group (n=15). Colon anastomotic leakage in the treatment group was repaired using the colonic sac duct, while the control group received conventional surgical repair. At 7, 14, and 21 days after the surgery, the healing of the anastomotic leakage was evaluated by examining the bursting pressure, tissue microvessel density and hydroxyproline content at the anastomosis.</p><p><b>RESULTS</b>Using the colonic sac duct, the anastomotic leakage was successfully repaired without death of the pigs or the occurrence of intestinal stenosis or necrosis. At 7 and 14 days after the surgery, the bursting pressure, hydroxyproline contents, and microvessel density in the treatment groups were higher than those in the control group, but such difference was not found at 21 days.</p><p><b>CONCLUSION</b>Colonic sac duct allows effective repair of colon anastomotic leakage, and is especially useful for leakage lasting for 48-72 h complicated by severe abdominal infection.</p>

Clinical application of 64-slice computed tomographic angiography-based virtual colonoscopy in the diagnosis of colonic tumors / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the clinical value of 64-slice computed tomographic angiography (CTA)-based virtual colonoscopy in the diagnosis of colonic tumors.</p><p><b>METHODS</b>Philips/Brilliance 64 CT volumetric scanning was performed in 8 patients with colonic cancer and 2 with colonic polypi identified by postoperative pathological examination. Mimics software was used for surface rendering of the intestine with the Marching Cubes algorithm for 3-dimensional (3D) virtual endoscope (VE) reconstruction and CTA-based 3D reconstruction of the large intestine and the surrounding structures. The location, volume and appearance of the lesions displayed by the virtual techniques were compared with the pathological results.</p><p><b>RESULTS</b>The 3D reconstruction was successfully completed in all the 10 cases, and the imaging diagnoses showed a total match with the pathological diagnoses. No significant differences were found between virtual endoscopy and CT virtual endoscopy. Virtual colonoscopy combined with digital model reconstruction provided valuable information for accurate identification of the position of the lesions and the complex adjacent anatomical structures.</p><p><b>CONCLUSION</b>Virtual colonoscopy based on 64-slice CTA, when combined with 3D reconstruction technique, allows accurate display of the colonic lesions and potential metastasis, which can be crucial for clinical staging and surgical planning of colonic cancer.</p>

Effect of adenovirus-mediated CD/TK double suicide gene system on colorectal cancer growth and cytokines in the tumor microenvironment in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of adenovirus-mediated CD/TK double suicide gene system on tumor growth and cytokine levels in the tumor microenvironment in mice bearing transplanted colorectal cancer.</p><p><b>METHODS</b>CT26 cells were implanted subcutaneously into 30 Balb/c mice, which were subsequently randomized into the control (n=15) and experimental group (n=15). After the tumor formation, CD/TK double suicide gene system was administered for tumor treatment, and the changes in the tumor volume, tumor inhibition rate, and levels of cytokines in the tumor microenvironment were investigated.</p><p><b>RESULTS</b>CD/TK double suicide gene system resulted in a significant inhibition of the tumor growth and significantly increased levels of such cytokines as IL-2, IL-10, TNFalpha and IFNgamma in the tumor microenvironment.</p><p><b>CONCLUSION</b>CD/TK double suicide gene system produces significant tumor inhibition effect and causes obvious cytokine changes in the tumor microenvironment in mice bearing transplanted colorectal cancer.</p>

A double suicide gene system driven by KDR promoter selectively kills human colon adneocarcinoma SW480 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the selective killing effect of adenovirus (Ad)-mediated double suicide gene system driven by the KDR promoter (KDR-CDglyTK) on human colon adneocarcinoma SW480 cells.</p><p><b>METHODS</b>KDR-expressing SW480 cells and LS174T cells that did not express KDR were infected by KDR-CDglyTK, and the infection efficiency and the expression of CDglyTK in the cells were detected by RT-PCR. The infected cells were treated with the prodrugs 5-FC and GCV at different concentrations, and the cell-killing effects and bystander effects were evaluated by MTT method. DNA content and the cell cycle changes in SW480 cells were detected by flow cytometry.</p><p><b>RESULTS</b>The expression of green fluorescent protein (GFP) was observed in 95% of the infected SW480 and LS174T cells with a multiplicity of infection (MOI) of 100. RT- PCR demonstrated that the product of CD/TK gene existed in SW480 cells infected by Ad- KDR- CD/TK, but not in infected LS174 cells. The infected SW480 cells exhibited high sensitivity to the prodrugs, but the infected LS174T cells did not (P<0.01). Bystander effects of the double suicide gene system were observed in the coculture of the infected and non-infected SW480 cells. At the MOI of 100, treatment of the infected cells with the prodrugs resulted in increased cell percentage in G(0)-G(1) phase and decreased percentage in S phase and the prodrug-treated cells showed an apoptotic peak in flow cytometry.</p><p><b>CONCLUSION</b>CDglyTK fusion gene system driven by the KDR promoter selectively kills and induces the apoptosis of the KDR-CDglyTK SW480 cells.</p>

Selective cytotoxic effect of lentivirus-mediated double suicide gene transfer on human gastric adneocarcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the selective cytotoxic effect of lentivirus-mediated double suicide gene (CD/TK) against human gastric carcinoma cells SGC-7901 in vitro.</p><p><b>METHODS</b>SGC-7901 cells were infected with FGW-KDRP-CD/TK vector and the infection efficiency was observed under a fluorescence microscope. The morphological changes of the infected cells were observed by Giemsa staining. Flow cytometry (FCM) was employed for cell cycle analysis, and the expression of CD/TK was detected by RT-PCR. The infected cells were then treated with the prodrugs ganciclovir (GCV) and/or 5-fluorocytosine (5-FC) at different concentrations, and the cytotoxic effects were evaluated using MTT method.</p><p><b>RESULTS</b>The infection efficiency of the lentiviral vector in SGC-7901 cells increased with the titer of the virus, which produced no significant effect on the cancer cell morphology in vitro or on the percentages of G0-G1, G2-M and S phase cells (P>0.05). RT-PCR demonstrated the expression of CD/TK gene in SGC-7901 cells infected by FGW-KDRP-CD/TK. The infected cells were highly sensitive to the prodrugs with a dose-dependent cytotoxic effect within a specific concentration range of the drugs, whereas the non-infected cells were not sensitive to the prodrugs. Combined use of the two prodrugs produced an obviously stronger inhibitory effect than either of the them (P<0.05). When combined, GCV and 5-FC at the concentration of 0.1+40, 1+80, 10+160, and 100+320 mg/L demonstrated a synergetic effect with a CDI<1.</p><p><b>CONCLUSION</b>Lentivirus-mediated CD/TK fusion gene system can selectively kill gastric cancer cells, and the two prodrugs show a synergistic cytotoxic effect.</p>

Inhibitory effect of recombinant adenovirus containing CDglyTK double suicide gene driven by KDR promoter on human stomach adneocarcinoma SCG7901 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the inhibitory effect of adenovirus-mediated fusion gene system driven by KDR promoter on the proliferation of human gastric adneocarcinoma SCG7901 cells and observe the bystander effect in vitro.</p><p><b>METHODS</b>SCG7901, ECV304 and HepG2 cells were infected with Ad-KDR-CDglyTK and Ad-CMV-CDglyTK at a multiplicity of infection (MOI) of 100, and the infection efficiency and the mRNA expressions of the transferred fusion gene were investigated. GCV and/or 5-FC at different concentrations were added into the culture medium of the infected cells to observe the targeted antitumor effect and bystander effect of CDglyTK suicide gene driven by KDR promoter.</p><p><b>RESULTS</b>With the MOI of the adenovirus of 100, the fluorescence emitted by green fluorescent protein (GFP) was observed in 95% of the infected SCG7901, ECV304 and HepG2 cells. All the cells infected by Ad-CMV-CDglyTK and SCG7901 and ECV304 cells infected by Ad-KDR-CDglyTK were highly sensitive to the prodrugs. In comparison, HepG2 cells infected with Ad-KDR-CDglyTK did not show much sensitivity to the two prodrugs. Following treatment with the prodrugs at the same concentration, the infected SCG7901 and ECV304 cells exhibited gradually lowered survival rates as the culture time was prolonged, whereas the transgenic HepG2 cells showed no such time-dependent changes. When the non-infected cells were cocultured with the transgenic cells, the bystander effect of CDglyTK gene was observed, which increased with the ratio of the transgenic cells. In these mixed cell culture systems, GCV and 5-FC showed obvious synergetic effect in suppressing the cell survival.</p><p><b>CONCLUSION</b>The CDglyTK fusion gene system driven by KDR promoter can inhibit the proliferation of SCG7901 and ECV304 cells with obvious bystander effect in vitro. The combination of the prodrugs produces obvious synergetic effect against the cell survival.</p>

Effect of KDR recombinant adenovirus containing double suicide gene on the proliferation of human colon adneocarcinoma SW620 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of adenovirus (Ad)-mediated fusion gene system driven by the KDR promoter on the proliferation of human colon adenocarcinoma SW620 cells.</p><p><b>METHODS</b>The KDR-expressing SW620 cells and LS174T cells not expressing KDR were both infected with AdEasy-KDR-CDglyTK followed by treatment with the prodrugs 5-FC and/or ganciclovir at different concentrations. The effect of the transfection on the cell proliferation was evaluated.</p><p><b>RESULTS</b>The expression of green fluorescent protein (GFP) was observed in 95% of the infected SW620 and LS174T cells with a multiplicity of infection (MOI) of 100. Significant difference was not founded in the growth of SW620 and LS174T cells with or without the transfection. The infected SW620 cells exhibit high sensitivity to the prodrugs, but the infected LS174T cells did not (P<0.01). The CDglyTK fusion gene produced much stronger killing effect of on the target cells than either of the single suicide genes (P<0.01).</p><p><b>CONCLUSION</b>CDglyTK fusion gene system driven by the KDR promoter selectively kills the KDR-CDglyTK SW620 cells and inhibits the cell proliferation.</p>

Establishment and evaluation of rabbit model of fecal incontinence / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish and evaluate a rabbit model of fecal incontinence.</p><p><b>METHODS</b>Twelve normal adult male New Zealand rabbits were randomly divided into experimental group and control group. The nerve innervating the external anal sphincter, namely the fourth sacral nerve, was functionally located and selectively damaged with local injection of 50 g/L ropivacaine in the experimental group, and normal saline injection was administered in the control group. The changes in the resting anal pressure was examined before and after the surgery, and the electromyogram (EMG) of the external anal sphincter was recorded for comparison with the pathological changes of the fourth sacral nerve.</p><p><b>RESULTS</b>Compared with the control group, the experimental group exhibited significantly decreased resting anal pressure after the surgery. The EMG of the experimental group showed abnormal nerve conduction velocity of the fourth sacral nerve, suggesting successful nerve block. Transmission electron microscope revealed irreversible pathological changes in the ultrastructure of the axons of the fourth sacral nerve.</p><p><b>CONCLUSION</b>This method allows successful establishment of fecal incontinence in rabbits, which facilitates further in vivo study of artificial sphincters for treatment of anal incontinence.</p>

Effect of targeted argon-helium cryoablation on the portal region in canine livers / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of targeted argon-helium cryoablation on portal region of the liver in dogs by observing the pathological changes in the first-order branches of the Glisson ductal system.</p><p><b>METHODS</b>Twelve healthy dogs underwent percutaneous targeted argon-helium cryoablation of the liver and sacrificed at 3 and 28 days after the cryoablation to observe the pathological changes in target area for cryoablation and the first-order branches of the Glisson ductal system.</p><p><b>RESULTS</b>No obvious damage was not found in the vascular wall of the portal vein by gross or microscopic observation, but the liver tissue in the vicinity of the blood vessels showed total necrosis. In spite of the injuries of different degrees in the first-order bile duct system after argon-helium cryoablation, no severe damages such as perforation or full-thickness necrosis occurred in bile duct wall, and most of the injuries were temporary and reversible. The size of the ablated area on day 28 was significantly reduced as compared with that on day 3 following the cryoablation (P<0.05). In the acute stage after the cryoablation (1-3 days), ALT and AST levels increased significantly in (P<0.05) but recovered 1-4 weeks later (P>0.05). The cryoablated area was basically consistent with the pathological area that underwent necrosis (P>0.05).</p><p><b>CONCLUSION</b>Targeted argon-helium cryoablation can cause total destruction of the liver tissue around the blood vessel without damaging the vascular walls of the portal vein. Argon-helium cryoablation induces relatively minor injuries to the bile duct of hepatic portal section and does not obviously damage the liver function, and the scope of tissue necrosis can be estimated according to the size of frozen area observed. Argon-helium cryoablation is a safe and minimally invasive operation with reliable therapeutic effect.</p>

A double suicide gene system driven by KDR promoter selectively kills human hepatic carcinoma cells and human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the selective killing effects of adenovirus (Ad)-mediated double suicide gene system driven by KDR promoter (KDR-CdglyTK) on the human hepatic carcinoma cells and human umbilical vein endothelial cells (HUVECs).</p><p><b>METHODS</b>KDR-expressing BEL-7402 and HUVECs and HepG2 cells that did not express KDR were infected by KDR-CdglyTK, and the infection efficiency and the expression of CdglyTK in the cells was detected by RT-PCR. The infected cells were treated with the the prodrugs 5-FC and GCV at different concentrations, and the cell-killing effects and bystander effects were evaluated by MTT method.</p><p><b>RESULTS</b>At the multiplicity of infection (MOI) of 100, the recombinant AdKDR-CDglyTK showed similar infection efficiency in the 3 cell lines. RT-PCR demonstrated CDglyTK expression in the recombinant adenovirus and the 3 infected cell lines. BEL-7402 and HUVECs infected by the KDR-CdglyTK, but not the HepG2 cells, were highly sensitive to the prodrugs (P<0.001). Bystander effects of the double suicide gene system were observed in the coculture of the infected and non-infected BEL-7402 and HUVECs.</p><p><b>CONCLUSION</b>The double suicide gene system driven by KDR promoter has specific killing effect on KDR-expressing hepatocellular carcinoma cells and HUVECs.</p>

Specific killing effects of combination of recombinant adenovirus containing double suicide gene driven by KDR promoter and survivin antisense oligonucleotide on colorectal cancer cells and vascular endothelial cells / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the specific killing effects of combination of recombinant adenovirus mediated double suicide gene driven by KDR promoter and survivin antisense oligonucleotide(ASODN) on colorectal cancer cells and vascular endothelial cells.</p><p><b>METHODS</b>The 293 packaging cells were transfected with the plasmids of pAdEasy-CDglyTK and the recombinant adenovirus were generated. The KDR expressive cells of SW620, ECV304 were infected with adenovirus, meanwhile survivinASODN was transferred into the same cells. The infection rate of adenovirus and transfection efficiency of survivinASODN were observed and the expression of CDglyTK was detected by RT-PCR. The expression of survivin was measured by Western blot. The killing effects and bystander effects on SW620, ECV304 were examined through MTT method.</p><p><b>RESULTS</b>The cells which were infected with the adenovirus mediated double suicide gene could be transfected with the survivin ASODN and the infection rate was not affected as well as the transfection efficiency. The high expression of CDglyTK gene was found in SW620, ECV304 cells infected with recombinant adenovirus and survivin ASODN decreased the survivin protein level. The survival rate of gene therapy group was significantly lower than that of negative group. The combination of survivin ASODN and AdKDR-CDglyTK gene therapy showed significantly lower survival rate of SW620 and ECV304 cells as compared with the AdKDR-CDglyTK or survivin ASODN used alone (P<0.05). The survival rate was slightly lower in GCV 100 microg/ml, 5-FC 2000 microg/ml than that AdKDR-CDglyTK used alone (P>0.05). The combined therapy of AdKDR-CDglyTK and survivin ASODN showed synergistic killing efficacy and more significant bystander effects.</p><p><b>CONCLUSION</b>The combined gene therapy of AdKDR-CDglyTK system and survivin ASODN has stronger specific killing effects on colorectal cancer cells and vein endothelial cells.</p>

Adenovirus-mediated double suicide gene selectively kills breast cancer MCF-7 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of adenovirus-mediated double suicide gene (CD/TK) for selective killing of breast cancer cells.</p><p><b>METHODS</b>Vascular endothelial growth factor (VEGF)-expressing MCF-7 cells and normal human mammary epithelial cells that did not express VEGF were infected with the adenovirus containing VEGFP-CD/TK-GFP genes. CD/TK gene expression in the infected cells was detected by RT-PCR. After treatment of the infected cells with GCV and/or 5-FC, the cell growth status was evaluated using MTT assay, and the cell cycle changes were detected with flow cytometry. In nude mice bearing human breast cancer, the recombinant adenovirus vector was injected directly into the tumor followed by intraperitoneal injection of the prodrugs GCV and/or 5-FC, and the subsequent tumor growth was observed.</p><p><b>RESULTS</b>The recombinant adenovirus achieved similar infection rates in MCF-7 and human mammary epithelial cells, and the rates increased gradually with the multiplicity of infection (MOI) of the virus. RT-PCR demonstrated the presence of CD/TK gene product in infected MCF-7 cells, but not in the infected mammary epithelial cells. The infected MCF-7 cells, but not the mammary epithelial cells, were highly sensitive to the pro-drugs. The CD/TK fusion gene system showed significantly greater efficiency than either of the single suicide gene in killing the target cells (P<0.01). At the MOI of 100, treatment of the infected cells with the pro-drugs resulted in increased cell percentage in G(0)-G(1) phase and decreased percentage in S phase. In nude mice bearing MCF-7 cell-derived subcutaneous tumor, treatment with the double suicide gene system significantly inhibited the tumor growth, showing much stronger effect than either of the single suicide gene (P<0.01).</p><p><b>CONCLUSION</b>The adenovirus-mediated CD/TK double suicide gene driven by VEGF promoter combined with GCV and 5-FC treatment can be an effective therapy against experimental breast cancer, and produces much greater efficacy than the single suicide gene CD/TK combined with GCV or 5-FC.</p>

A survey of bile duct injuries sustained during laparoscopic cholecystectomy / 中华外科杂志

<p><b>OBJECTIVE</b>To summarize the reasons for bile duct injury (BDI) after laparoscopic cholecystectomy (LC), and to determine the effect of multiple treatment after BDI.</p><p><b>METHODS</b>A retrospective cohort study was performed. The medical records of 110 patients diagnosed with BDI after LC from October 1993 to November 2007, in ten large hospitals in Guangdong of China, were reviewed.</p><p><b>RESULTS</b>Among 110 patients with BDI, 58 cases (52.7%) were local patients, whereas 52 cases (47.3%) were transferred from outside hospitals. Reasons for BDI following LC were: (1) Lack of experience of the LC operator (48.2%); (2) LC performed during acute cholecystitis (20.0%); (3) The structure of Calot triangle was unclear (15.5%); (4) Variable anatomical position (11.8%); (5) Intra-operation bleeding (4.5%). The commonest sites of injury were the choledochus and common hepatic duct (76.4%). Following BDI, endoscopic stenting or operative repair was performed in 106 patients. The overall success rate was 95.3% (101/106), with a mortality rate was 0.9% (1/106). Cholangitis occurred in 3.8% (4/106) cases. Choledocho-enterostomy operation was performed in almost 60.0% (63/106) cases, and the success rate was 93.7% (59/63). Endoscopic stenting or operative repair was performed immediately following BDI in 23.6% (25/106) patients, the success rate was 100%; and within 30 days in 63.2% (67/106) patients. Eighty-eight out of 106 patients who underwent repair were successful following the first operative procedure.</p><p><b>CONCLUSIONS</b>Factors such as an un-experienced operator and unclear anatomical position were causes of BDI following LC. Early operative repair should be regarded as the treatment of choice, in patients diagnosed with BDI. Early refer to an experienced hepatobiliary operator ensures a high success rate.</p>

Reconstruction of a digital three-dimensional model of the rectum and the surrounding structures based on CT angiographic data / 南方医科大学学报

<p><b>OBJECTIVE</b>To reconstruct a digital three-dimensional model of the rectum and the surrounding structures based on CT angiographic (CTA) data.</p><p><b>METHODS</b>Based on air pressure enema and CTA, the chest T12 level to upper portion of the femur of a healthy volunteer was scanned with 64-slice spiral CT in the arterial phase and venous phase. The rectum and the surrounding structures were reconstructed with Mimics software based on the two-dimensional images of 856 consecutive layers obtained by Dicom 3.0 standard CT. The model was validated using finite element analysis software.</p><p><b>RESULTS AND CONCLUSION</b>The established three-dimensional digital model allowed clear visualization of such structures of the lumbar vertebrae, pelvis, femur, abdominal aorta, internal iliac artery, external iliac artery, branches of the external iliac artery, skin, rectum, the colons, part of the small intestines, and the urinary bladder and prostate. The application of thin-layer CT and Dicom 3.0 standard renders better accuracy of the established digital model, which can provide a platform for surgical skill training and teaching of anatomy.</p>

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>

Polyamidoamine dendrimer-mediated survivin antisense oligonucleotide inhibits the growth of subcutaneously transplanted colorectal cancer in nude mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the inhibitory effects of survivin antisense oligonucleotide (survivin-ASODN) mediated by polyamidoamine dendrimer (PAMAM) against the growth of subcutaneously transplanted colorectal cancer in nude mice.</p><p><b>METHODS</b>Nude mouse models bearing colorectal cancer was established by subcutaneous injection of SW620 cells. Survivin- OSADN (300 microg/L) was mixed with 4.06 microg/L PAMAM or liposome to prepare two transfection complexes, and their morphologies were observed by transmission electron microscope. The particle size of the prepared complexes was determined by laser particle size analyzer, and the zeta potential was measured. The encapsulation efficiency and the DNA release rate in vitro were determined by ultraviolet spectrophotometer. The transfection complexes were then directly injected into the xenografts of the tumor-bearing nude mice. The tumor volume changes were observed, and the expression of survivin in the transplanted tumor was measured by Western blotting.</p><p><b>RESULTS</b>The PAMAM-survivin-ASODN complex had a significantly smaller diameter and greater zeta potential than liposome-survivin-ASODN (P<0.01 and 0.05, respectively). The encapsulation efficiency was comparable between the two complexes. In in vitro condition, PAMAM-survivin-ASODN allowed sustained survivin-ASODN release for as long as 14 days, as compared with the 5 days for the liposome complex. After injection into the tumor xenografts, PAMAM-survivin- ASODN resulted in significantly lower expression of survivin protein in the transplanted tumors (P<0.05), and also in significantly greater reduction of the tumor volume than the liposome complex (P<0.05).</p><p><b>CONCLUSION</b>PAMAM can effectively deliver survivin-ASODN into transplanted colorectal tumor cells to reduce the expression of survivin and inhibit the tumor growth.</p>

Specific killing effects of combination of double suicide gene and survivin antisense oligonucleotide on breast tumor cells and vein endothelial cells / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the selectively killing effects of combination of adenovirus mediated double suicide gene driven by kinase-domain insert containing receptor (KDR) promoter and survivin antisense oligonucleotide on breast tumor cells and vein endothelial cells.</p><p><b>METHODS</b>Human embryonal kidney cells 293 were transfected with the plasmids of pAdEasy-KDR-CDglyTK and the adenovirus was generated. The KDR expressive cells of MCF-7, ECV304 were infected by adenovirus and survivin ASODN was transferred into the same cells meanwhile. The infection rates of adenovirus and transfection efficiency of survivin ASODN were observed and the expression of CDglyTK was detected by RT-PCR. The expression of survivin was measured by Western blot. The killing effects and bystander effects on cells were assessed by MTT assay.</p><p><b>RESULTS</b>The cells infected by the adenovirus mediated double suicide gene could be transfected with the survivin ASODN and the infection rate was not affected as well as the transfection rate. The high expression of CDglyTK gene was found in the two kinds of cells and survivin ASODN decreased the survivin protein level. When survivin ASODN was transferred into MCF-7, ECV304 cells, the survival rates were 56.4% +/- 3.8% and 55.9% +/- 3.6% respectively. The combination of survivin ASODN and AdKDR-CDglyTK gene therapy showed significantly lower survival rate comparing with using each treatment alone (P < 0.05) and the survival rate decreased gradually with the increasing of the concentration of GCV and 5-FC. But the survival rate for combined gene therapy group was slightly lower in GCV 100 microg/ml, 5-FC 2000 microg/ml than that of AdKDR-CDglyTK group (P > 0.05). The combination of survivin ASODN and AdKDR-CDglyTK therapy showed synergistic killing efficacy and more significant bystander effects.</p><p><b>CONCLUSION</b>The combined therapy with AdKDR-CDglyTK system and survivin ASODN shows obvious killing effects on breast tumor cells and vein endothelial cells.</p>

Preliminary effect of VEGF promoter-driven recombinant adenovirus containing double suicide genes on apoptosis of human gastric carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of the adenovirus containing CD/TK fusion gene controlled by the human vascular endothelial growth factor (VEGF) promoter on apoptosis of human gastric carcinoma cells SGC-7901.</p><p><b>METHODS</b>VEGF-expressing SGC-7901 cells were infected by the recombinant adenovirus Ad-VEGFP-CD/TK, and the infection efficiencies were observed with fluorescence microscopy. The toxic effect and intracellular calcium concentration induced by 5-fluorocytosine (5-FC) and ganciclovic (GCV) were determined by light microscopy, electron microscopy and flow cytometry.</p><p><b>RESULTS</b>The transfection efficiency of the recombinant adenovirus in SGC-7901 cells increased with the viral titer. At the multiplicity of infection (MOI) of 100, 5-FC and GCV could induce apoptosis of SGC-7901 cells within a given dose range in a dose- and time-dependent manner, and apoptotic changes of the cells were observed with electron microscopy. Apoptotic peak was also detected by flow cytometry. Cell cycle analysis revealed increased cell percentage in G(0)-G(1) phase and decreased percentage of cells in G(2)-M and S phases in response to treatment with the pro-drugs, which also induced marked elevation of intracellular calcium concentration in the infected cells.</p><p><b>CONCLUSIONS</b>CD/TK fusion gene system driven by VECF promoter selectively induces apoptosis of VEGF-expressing SGC-7901 cells, the action of which is probably mediated by intracellular calcium variation.</p>