Esophagus two-step-cut overlap method in esophagojejunostomy after laparoscopic gastrectomy.

PURPOSE: Esophagojejunostomy is a challenging step in laparoscopic gastrectomy. Although the overlap method is a safe and feasible approach for esophagojejunostomy, it has several technical limitations. We developed novel modifications for the overlap method to overcome these disadvantages. METHODS: Forty-eight consecutive gastric cancer patients underwent totally laparoscopic total gastrectomy or laparoscopic proximal gastrectomy with double-tract reconstruction at our institution from January 2019 to April 2020 using the overlap method with the following modifications. The esophagus was initially rotated by 90° counterclockwise, followed by transection of two-thirds of the esophageal diameter. The unstapled esophagus was then transected with a harmonic ultrasonic scalpel to enable esophagostomy at the posterior side of the esophagus. A side-to-side esophagojejunostomy was then formed at the posterior side of the esophagus using an endoscopic linear stapler through the right lower trocar. The common entry hole was closed via hand sewing method using V-Loc suture. This procedure was termed "esophagus two-step-cut overlap method." RESULTS: Only one patient suffered from esophagojejunal anastomotic leakage but subsequently recovered after conservative treatment. Patients did not experience anastomotic bleeding or stricture. CONCLUSION: Our modified overlap method provides satisfactory surgical outcomes and overcomes several technical limitations, such as entering the false lumen of the esophagus, unnecessary pollution caused by nasogastric tube, and unintended left crus stapling during anastomosis.

Effects of autophagy regulation of tumor-associated macrophages on radiosensitivity of colorectal cancer cells.

Tumor­associated macrophages (TAMs), a major component of the tumor microenvironment, are crucial to the processes of tumor growth, infiltration and metastasis, and contribute to drug resistance. The importance of TAMs in radiation resistance of colorectal cancer remains unclear. To investigate the effects of autophagy regulation of TAMs on the radiosensitivity of colorectal cancer cells, the current study induced TAM formation from THP­1 monocyte cells. Sequential treatment of THP­1 cells with PMA for 72 h and human recombinant interleukin­4 for 24 h was used to stimulate THP­1 differentiation to TAMs. Expression of the cell surface markers CD68, CD204 and CD206, and changes to cell morphology were used to confirm successful differentiation. The TAMs were stimulated to promote or inhibit autophagy during co­culture with LoVo colorectal adenocarcinoma cells. The cells were irradiated, with subsequent measurement of LoVo colony formation and apoptosis. Additionally, the expression of p53, Bcl­2, survivin and Smac proteins was assessed by western blotting. Monodansylcadaverin staining was used to analyze the presence of autophagic vacuoles in TAM, and western blot analysis was used to assess the expression of Beclin­1, LC3B I and II, ATG­3, ­5 and ­7. The results demonstrated TAM autophagy to be markedly altered by rapamycin and bafilomycin A1 treatment. Following co­culture with TAMs, the colony formation rate and survival fraction of LoVo cells were significantly higher than those in the control group (P<0.05). It was further demonstrated that the regulation of autophagy in TAMs was able to inhibit the colony formation of LoVo colorectal cancer cells. Upregulation of TAM autophagy using rapamycin exhibited more effective inhibition of LoVo colony formation than autophagy downregulation. Notably, apoptosis was significantly increased in LoVo cells when co­cultured with TAMs only, or with rapamycin­mediated autophagy upregulated TAMs, compared with LoVo cells cultured alone (P<0.01). Expression of Bcl­2, survivin and p53 were reduced in LoVo cells co­cultured with TAMs, compared with the control group (P<0.05), whereas Smac expression was increased in the co­culture groups (P<0.01). It was demonstrated that rapamycin­mediated autophagy stimulation in TAMs led to reduced expression levels of survivin and Bcl­2, however, Smac expression was increased. The upregulation of autophagy in TAMs inhibited proliferation and induced apoptosis in colon cancer cells, and altered the expression of radiosensitivity­associated proteins. This data indicated that the radiosensitivity of colorectal cancer cells is associated with autophagy of TAM, and that stimulating TAM autophagy may increase the radiosensitivity of colorectal cancer cells.

HMGB1 Promotes Mitochondrial Dysfunction-Triggered Striatal Neurodegeneration via Autophagy and Apoptosis Activation.

Impairments in mitochondrial energy metabolism are thought to be involved in many neurodegenerative diseases. The mitochondrial inhibitor 3-nitropropionic acid (3-NP) induces striatal pathology mimicking neurodegeneration in vivo. Previous studies showed that 3-NP also triggered autophagy activation and apoptosis. In this study, we focused on the high-mobility group box 1 (HMGB1) protein, which is important in oxidative stress signaling as well as in autophagy and apoptosis, to explore whether the mechanisms of autophagy and apoptosis in neurodegenerative diseases are associated with metabolic impairment. To elucidate the role of HMGB1 in striatal degeneration, we investigated the impact of HMGB1 on autophagy activation and cell death induced by 3-NP. We intoxicated rat striata with 3-NP by stereotaxic injection and analyzed changes in expression HMGB1, proapoptotic proteins caspase-3 and phospho-c-Jun amino-terminal kinases (p-JNK). 3-NP-induced elevations in p-JNK, cleaved caspase-3, and autophagic marker LC3-II as well as reduction in SQSTM1 (p62), were significantly reduced by the HMGB1 inhibitor glycyrrhizin. Glycyrrhizin also significantly inhibited 3-NP-induced striatal damage. Neuronal death was replicated by exposing primary striatal neurons in culture to 3-NP. It was clear that HMGB1 was important for basal autophagy which was shown by rescue of cells through HMGB1 targeting shRNA approach.3-NP also induced the expression of HMGB1, p-JNK, and LC3-II in striatal neurons, and p-JNK expression was significantly reduced by shRNA knockdown of HMGB1, an effect that was reversed by exogenously increased expression of HMGB1. These results suggest that HMGB1 plays important roles in signaling for both autophagy and apoptosis in neurodegeneration induced by mitochondrial dysfunction.

Effects of 5­fluorouracil and class III phosphoinositide 3­kinase small interfering RNA combination therapy on SGC7901 human gastric cancer cells.

The aim of the present study was to investigate the effects of small interfering RNA­mediated inhibition of Class III phosphoinositide 3­kinase (PI3K) signal transduction on the proliferation, apoptosis and autophagy of SGC7901 gastric cancer cells. The present study also aimed to examine the contribution of autophagic inhibition to the antitumor effects of 5­fluorouracil (5­FU). A PI3K(III)­RNA interference (i)­green fluorescent protein (GFP) recombinant replication adenovirus (AD) and the negative control (NC)­RNAi­GFP control AD were constructed and infected into SGC7901 cells. A methyl thiazolyl tetrazolium assay was used to determine the growth rate of the SGC7901 cells. Immunofluorescent staining was used to detect microtubule­associated protein 1 light chain 3 expression. The mitochondrial membrane potential was measured using the JC­1 fluorescent probe. Autophagic expression was monitored with MDC staining and transmission electron microscopy. The results revealed that following combination treatment of the SGC7901 gastric cancer cells with 5­FU + PI3K(III)­RNAi­AD, the optical density absorbance values at 24, 48 and 72 h were 0.17 ± 1.64, 0.13 ± 4.64 and 0.11 ± 3.56%, respectively, with cell viability inhibition ratios of 45.89 ± 6.67, 72.57 ± 9.48 and 87.51 ± 4.65%, respectively. As compared with the other treatment groups, the inhibition rate in the combined treatment group was significantly higher (P<0.05). The percentages of the cells with green fluorescence in the combined treatment group were 74.4 ± 3.86 (24 h), 82.3 ± 1.84 (48 h) and 92.5 ± 1.1% (72 h), which were larger than those of the other groups. The percentage of cells with green fluorescence became larger, which indicated that the mitochondrion membrane potential had been reduced to a greater extent. MDC staining revealed that the number of autophagic vacuoles in the cells (measured at 24, 48 and 72 h) decreased gradually with time, with more autophagic vacuoles observed in the cells in the control group at 24 h than those in the other treatment groups. Fewest autophagic vacuoles were identified in the combined treatment group. Using a fluorescence microscope, the immune fluorescence expression of microtubule­associated proteins 1A/1B light chain 3A, which is the specific protein of autophagy, in the combined treatment group was observed to be significantly downregulated, as compared with the other groups. As determined by transmission electron microscopic observation of the SGC7901 gastric cancer cells, the degree of autophagy in the combined treatment group was significantly reduced, as compared with that of the other treatment groups. In conclusion, following combined treatment with 5­FU and an inhibitor of class III PI3K signal transduction, the proliferation of SGC7901 cells was significantly suppressed, the mitochondrion membrane potentials were significantly reduced and the expression levels of autophagic markers were significantly downregulated.

Effects of damage-regulated autophagy regulator gene on the SGC7901 human gastric cancer cell line.

The aim of this study was to investigate the effects of the adenoviral-mediated autophagy gene, damage-regulated autophagy regulator (DRAM), on the proliferation and autophagy of SGC7901 human gastric cancer cells in vitro. The recombinant adenovirus, AdMax-pDC315-DRAM-EGFP, working as a virus vector of DRAM was constructed and infected into the SGC7901 human gastric cancer cell line. The MTT assay was used to determine the growth rate of the SGC7901 cells. Activation of autophagy was monitored with monodansylcadaverin (MDC) staining following AdMax-pDC315-DRAM-EGFP treatment. Immunofluorescent staining was used to examine the expression of microtubule-associated protein 1 light chain 3 (LC3), and western blotting was used to examine the expression of apoptosis- and autophagy-associated proteins, including Beclin1, p53, p21 and B-cell lymphoma 2 (Bcl-2), in the culture supernatant. The viability of the SGC7901 cells was activated by AdMax-pDC315-DRAM-EGFP treatment. The AdMax-pDC315-DRAM-EGFP-treated cells exhibited positive LC3 expression detected by immunoreactivity and MDC staining. Inductions in the expression of the apoptosis-related proteins, p53 and p21, and the autophagic protein, Beclin1, were revealed by western blot analysis. By contrast, downregulation of the apoptosis-related protein, Bcl-2, following AdMax-pDC315-DRAM-EGFP treatment was identified. In conclusion, the present study demonstrated that AdMax-pDC315-DRAM-EGFP treatment resulted in upregulation of the level of autophagy and induction of cell proliferation in the SGC7901 human gastric cancer cell line in vitro.

Blocking Bcl-2 leads to autophagy activation and cell death of the HEPG2 liver cancer cell line.

BACKGROUND: Apoptosis may be induced after Bcl-2 expression is inhibited in proliferative cancer cells. This study focused on the effect of autophagy activation by ABT737 on anti-tumor effects of epirubicin. METHODS: Cytotoxic effects of ABT737 on the HepG2 liver cancer cell line were assessed by MTT assay and cell apoptosis through flow cytometry. Mitochondrial membrane potential was measured by fluorescence microscopy. Monodansylcadaverin (MDC) staining was used to detect activation of autophagy. Expression of p53, p62, LC3, and Beclin1, apoptotic or autophagy related proteins, was detected by Western blotting. RESULTS: ABT737 and epirubicin induced growth inhibition in HepG2 cells in a dose- and time-dependent manner. Both ABT737 and epirubicin alone could induce cell apoptosis with a reduction in mitochondrial membrane potential as well as increased apoptotic protein expression. Further increase of apoptosis was detected when HepG2 cells were co- treated with ABT373 and epirubicin. Furthermore, our results demonstrated that ABT373 or epirubicin ccould activate cell autophagy with elevated autophagosome formation, increased expression of autophagy related proteins and LC3 fluorescent puncta. CONCLUSIONS: ABT737 influences cancer cells through both apoptotic and autophagic mechanisms, and ABT737 may enhance the effects of epirubicin on HepG2 cells by activating autophagy and inducing apoptosis.

Blockade of NF-κB nuclear translocation results in the inhibition of the invasiveness of human gastric cancer cells.

The aim of the present study was to investigate the effect of the nuclear factor-κB (NF-κB) p65 inhibitor, SN50, on the invasiveness and mechanisms of SGC7901 human gastric carcinoma cell xenografts in nude mice. Nude mice were randomly divided into model control and SN50 treatment groups. On days 5, 10 and 15 following treatment, the tumor samples were observed and a selection of parameters were recorded, including the level of tumor growth inhibition, the pathological changes in the tumor specimens, the expression levels of matrix metalloproteinase-9 (MMP-9), proliferating cell nuclear antigen (PCNA), tissue inhibitor of metalloproteinases type-1 (TIMP-1) and vascular endothelial growth factor (VEGF) and the apoptosis indices in the tumor samples. The results demonstrated that treating the tumor with SN50 for 5, 10 and 15 days inhibited carcinoma growth in comparison with the control group. Hematoxylin and eosin (HE) staining indicated that the level of inhibition increased progressively, in correlation with apoptosis. The expression of the MMP-9, PCNA and VEGF proteins was observed to be downregulated, while that of the TIMP-1 protein was shown to be upregulated, using immunohistochemical staining. In conclusion, the NF-κB p65 inhibitor, SN50, inhibited the invasiveness of the gastric cancer cells by downregulating the protein expression of MMP-9, PCNA and VEGF and upregulating the protein expression of TIMP-1. It was further suggested that SN50 may be a molecular target of anti-invasion therapy for gastric cancer, and that the inhibition of the NF-κB p65 signaling pathway may be considered as a potential strategy for treating gastric cancer.

[Effects of class I( phosphatidylinositol-3-kinases inhibitor on gastric cancer cell xenografts in nude mice].

OBJECTIVE: To investigate the effect of recombinant adenovirus (phosphatidylinositol-3-kinases(PI3K)(I()-RNAi-AD which blocks the class I( PI3K signaling pathway on gastric carcinoma cells xenografts in nude mice. METHODS: Subcutaneous tumor models of nude mice were established with SGC7901 cells and randomly divided into PI3K(I()-RNAi-AD group, NC-RNAi-GFP-AD group and control group. The tumor size and the inhibitory rate of tumor growth on days 3, 6, and 9 after cell transplantation were measured. The expression of TNF-α, COX2, P53, PCNA, E-cadherin and nm23/DNPK in tumor tissues were detected by immunohistochemistry. RESULTS: Tumor growth was significantly inhibited in the PI3K(I()-RNAi-AD group(14.2%, 21.0%, and 28.1%) on days 3, 6, 9 compared with NC-RNAi-GFP-AD group(1.3%, 1.9%, and 2.0%, all P<0.05). The expressions of TNF-α, P53, E-cadherin and nm23/DNPK were up-regulated, and the expressions of COX2 and PCNA were down-regulated in the PI3K(I()-RNAi-AD group by immunohistochemical staining(all P<0.05). CONCLUSIONS: PI3K(I()-RNAi-AD can inhibit the growth of SGC7901 cell transplantation tumor in vivo in nude mice by inhibiting cell growth, reducing the capacity of tumor invasion and inhibiting tumor angiogenesis.

Effects of small interfering RNA inhibit Class I phosphoinositide 3-kinase on human gastric cancer cells.

AIM: To investigate the effects of small interfering RNA (siRNA)-mediated inhibition of Class I phosphoinositide 3-kinase (Class I PI3K) signal transduction on the proliferation, apoptosis, and autophagy of gastric cancer SGC7901 and MGC803 cells. METHODS: We constructed the recombinant replication adenovirus PI3K(I)-RNA interference (RNAi)-green fluorescent protein (GFP) and control adenovirus NC-RNAi-GFP, and infected it into human gastric cancer cells. MTT assay was used to determine the growth rate of the gastric cancer cells. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after adenovirus PI3K(I)-RNAi-GFP and control adenovirus NC-RNAi-GFP treatment. Immunofluorescence staining was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. The expression of autophagy was monitored with MDC, LC3 staining, and transmission electron microscopy. Western blotting was used to detect p53, Beclin-1, Bcl-2, and LC3 protein expression in the culture supernatant. RESULTS: The viability of gastric cancer cells was inhibited after siRNA targeting to the Class I PI3K blocked Class I PI3K signal pathway. MTT assays revealed that, after SGC7901 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 27.48% ± 2.71% at 24 h, 41.92% ± 2.02% at 48 h, and 50.85% ± 0.91% at 72 h. After MGC803 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 24.39% ± 0.93% at 24 h, 47.00% ± 0.87% at 48 h, and 70.30% ± 0.86% at 72 h (P < 0.05 compared to control group). It was determined that when 50 MOI, the transfection efficiency was 95% ± 2.4%. Adenovirus PI3K(I)-RNAi-GFP (50 MOI) induced mitochondrial dysfunction and activated cell apoptosis in SGC7901 cells, and the results described here prove that RNAi of Class I PI3K induced apoptosis in SGC7901 cells. The results showed that adenovirus PI3K(I)-RNAi-GFP transfection induced punctate distribution of LC3 immunoreactivity, indicating increased formation of autophagosomes. The results showed that the basal level of Beclin-1 and LC3 protein in SGC7901 cells was low. After incubating with adenovirus PI3K(I)-RNAi-GFP (50 MOI), Beclin-1, LC3, and p53 protein expression was significantly increased from 24 to 72 h. We also found that Bcl-2 protein expression down-regulated with the treatment of adenovirus PI3K(I)-RNAi-GFP (50 MOI). A number of isolated membranes, possibly derived from ribosome-free endoplasmic reticulum, were seen. These isolated membranes were elongated and curved to engulf a cytoplasmic fraction and organelles. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after adenovirus PI3K(I)-RNAi-GFP (50 MOI) treatment. Control cells showed a round shape and contained normal-looking organelles, nucleus, and chromatin, while adenovirus PI3K(I)-RNAi-GFP (50 MOI)-treated cells exhibited the typical signs of autophagy. CONCLUSION: After the Class I PI3K signaling pathway has been blocked by siRNA, the proliferation of cells was inhibited and the apoptosis of gastric cancer cells was enhanced.

SN50 enhances the effects of LY294002 on cell death induction in gastric cancer cell line SGC7901.

INTRODUCTION: In the previous study, we found that the inhibition of phosphatidylinositol 3-kinase (PI3K) by LY294002 induced SGC7901 cell death in vitro. We did not know whether SN50, which is a specific inhibitor of nuclear factor κB (NF-κB), could increase the cell death induction of gastric cancer of LY294002 in vitro, and we also wanted to know the mechanism of it, which might be applied to clinical tumor therapy. MATERIAL AND METHODS: The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cytotoxic effects of the drugs. Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Hoechst 33258 staining was used to detect apoptosis and necrosis morphological changes after LY294002 and/or SN50 treatment. Expression of p53, PUMA and Beclin1 were determined with real-time polymerase chain reaction (RT-PCR) analysis. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after LY294002 and/or SN50 treatment. RESULTS: In this study, we found that treating the human gastric cancer cells SGC7901 with SN50 could significantly enhance the effects of LY294002 on inducing cell death after 24 h, compared to the control group (p < 0.05). Detection of mitochondrial potential and transmission electron microscopic examination indicated that the rate of cell death increased progressively. The expression of p53, PUMA and Beclin1 was up-regulated. CONCLUSIONS: The NF-κB inhibitor SN50 could enhance the role of LY294002 on inducing cell death of human gastric cancer cells SGC7901, which might be a promising new approach to gastric cancer therapy.

Fistula plug versus conventional surgical treatment for anal fistulas. A system review and meta-analysis.

OBJECTIVE: To evaluate the recurrence and fecal incontinence of anal fistula plug versus conventional surgical treatment for anal fistulas. METHODS: This meta-analysis was carried out in the General Surgery Department of the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China. We searched the Medline, EMBASE, and Cochrane Library from June 2011 to April 2012. The literature searches were carried out using medical subject headings and free-text word: anal fistula, fibrin adhesive, fibrin sealant, and fistula plug. RESULTS: Two randomized controlled trials and 3 retrospective controlled studies were included. A total of 428 patients were included in our study. The recurrence rate was higher in those patients who accept fistula plug treatment (62.1% versus 47%) (p=0.004). CONCLUSION: Anal fistula plug has a moderate probability of success with little risk of incontinence, but the recurrence rate is significantly higher than the conventional surgical treatment. This treatment is minimally invasive, repeatable, and sphincter-sparing. This meta-analysis failed to find a statistically significant difference in incontinence rate between conservative treatment and conventional surgical treatment.

[Effects of damage-regulated autophagy modulator on the radiosensitivity of SGC7901 cell xenografts in nude mice].

OBJECTIVE: To investigate the effects of damage-regulated autophagy modulator (DRAM) on radiosensitivity and the related mechanisms of implanted tumors of SGC7901 human gastric carcinoma cells in nude mice. METHODS: Nude mice were randomly divided into model control group, radiotherapy group, and DRAM treatment group and radiotherapy combined with DRAM treatment group. When volume of transplantation tumor were 1.0 cm(3), radiotherapy, DRAM treatment was given. On days 3, 6 and 9 after treatment, the inhibition rate of tumor growth, pathological changes in tumor specimens, expression levels of P53, proliferating cell nuclear antigen(PCNA), C-myc, Fas-L, as well as apoptosis indexes in tumor samples were observed. RESULTS: Inhibition rates of tumor in DRAM combined with radiotherapy were 9.3%, 14.1%, 16.7% on day 3, 6 and 9, respectively, all significantly higher than those in the radiotherapy group(5.0%, 8.8%, 6.5%, P<0.05). The expressions of PCNA and C-myc protein were down-regulated, while the expressions of P53 and Fas-L were upregulated. CONCLUSION: Damage-regulated autophagy modulator gene may promote cell apoptosis and inhibit cell growth to enhance the radiosensitivity of transplanted gastric tumor in vivo in nude mice.

TEM and conventional rectal surgery for T1 rectal cancer: a meta-analysis.

BACKGROUND/AIMS: To compare transanal endoscopic microsurgery (TEM) with conventional radical surgery (CRS) for T1 rectal cancer focusing on safety, feasibility and efficacy of both procedures. METHODOLOGY: An online search of Ovid, Medline, Embase, Pubmed and Cochrane Controlled Trials Register was undertaken to identify studies comparing TEM with CRS published in English between 1984 and March 2010. Only studies comparing TEM with CRS for T1 rectal cancer treatment and with a minimum of 20 cases were included. The parameters compared were postoperative complications, hospital mortality, recurrence rate and 5-year survival. RESULTS: Five studies met screening criteria and 397 patients were enrolled in the meta-analysis; 216 were treated with TEM and the rest received CRS. Complications were observed in 16/196 in the TEM group and 77/163 in the CRS group. The difference was significant (p=0.01). The rate of mortality was 3.68% in CRS group, and 0 in TEM group (p=0.01). The 5-year survival was similar (p=0.84), the TEM group was 80.1% and the CRS group was 81.0%. However, there was more recurrence in the TEM group compared to CRS group (p=0.0004). TEM group was 12.0%, while CRS group was 0.5%. CONCLUSION: Compared with CRS, TEM had significant shorter hospital stay and fewer postoperative complications. TEM is a safe, feasible and effective option for T1 rectal cancer. Though TEM had a slightly higher rate of recurrence than CRS, no significant difference on 5-year survival was observed.

Haplotype analysis of CTLA4 gene and risk of esophageal squamous cell carcinoma in Anyang area of China.

BACKGROUND/AIMS: To study the effect of cytotoxic T-lymphocyte antigen 4 gene haplotypes to susceptibility of esophageal squamous cell carcinoma. METHODOLOGY: A gender- and age-matched case-control design was used in this study. PCR-RFLP method was used to detect the genotype of CTLA4 in 205 patients and 205 control individuals in the Anyang area. Furthermore, haplotypes were calculated by PHASE2.1 software. Finally, the conditional logistic regression analysis was carried out to analyze the relevance between the risk of ESCC and the genotypes or haplotypes of CTLA4 gene. RESULTS: The CTLA4 rs231775 and rs4553808 genotypes in patients with ESCC were significantly different from controls (p=0.004, p=0.023, respectively). The AG and AA genotypes of rs231775 were highly correlated with the risk of ESCC (Adjusted OR=2.280, 95%CI=1.433-3.629, p=0.001; Adjusted OR=2.192, 95%CI=1.229-3.911, p=0.008, respectively), and AG genotype of rs4553808 also increased the susceptibility of ESCC (Adjusted OR=1.848, 95%CI=1.220-2.800, p=0.004). Further study suggested that AAG haplotype may enhance the risk of ESCC (Adjusted OR=5.035, 95%CI=1.599-15.860, p=0.005), but GAA haplotype played a protective role (Adjusted OR=0.413, 95%CI=0.251-0.680, p=0.001). CONCLUSIONS: Our research confirmed that CTLA4 genetic variation was related to ESCC in the Anyang area and GAA haplotype was the protective factor of ESCC.

[Effects of combined therapy of LY294002 and SN50 on nude mice model with gastric cancer].

OBJECTIVE: To investigate the effect of phosphatidylinositol 3-kinase inhibitor LY294002 combined with NF-κB P65 nuclear translocation inhibitor SN50 on the tumor cell growth and apoptosis using a nude mouse model of gastric cancer. METHODS: Human gastric cancer cell strain SGC7901 was transplanted subcutaneously to nude mice to establish tumor models. Model mice were randomly divided into the control group, the LY294002 treatment group, the SN50 treatment group, and the LY294002+SN50 treatment group, with 5 in each group. After being treated for 10 days, the inhibition rate of tumor growth was ascertained by measuring the size of tumor. Immunohistochemical method was used to detect the expression levels of Bcl-2, P53 and Bax proteins and transmission electron microscopy to investigate the apoptosis of tumor cells. RESULTS: On the 10th day after treatment, the inhibition rate of gastric cancer cellular growth in the LY294002+SN50 group was (49.2±2.5)%, which was significantly higher than that in the LY294002 group(29.4±1.5)% and SN50 group (19.7±1.6)%(P<0.05). In comparison with the other two groups, LY294002+SN50 group exhibited more severe apoptosis, with expression of Bcl-2 decreased and that of P53 and Bax increased more significantly(P<0.05). CONCLUSION: LY294002 combined with SN50 inhibits the growth of SGC7901 transplanted tumor and aggravates the apoptosis of gastric cancer cells in nude mice model.

Blocking NF-κB nuclear translocation leads to p53-related autophagy activation and cell apoptosis.

AIM: To investigate the anti-tumor effects of nuclear factor-κB (NF-κB) inhibitor SN50 and related mechanisms of SGC7901 human gastric carcinoma cells. METHODS: MTT assay was used to determine the cytotoxic effects of SN50 in gastric cancer cell line SGC7901. Hoechst 33258 staining was used to detect apoptosis morphological changes after SN50 treatment. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after SN50 treatment. Immunofluorescence staining was used to detect the expression of light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Western blotting analysis were used to determine the expression of proteins involved in apoptosis and autophagy including p53, p53 upregulated modulator of apoptosis (PUMA), damage-regulated autophagy modulator (DRAM), LC3 and Beclin 1. We detected the effects of p53-mediated autophagy activation on the apoptosis of SGC7901 cells with the p53 inhibitor pifithrin-α. RESULTS: The viability of SGC7901 cells was inhibited after SN50 treatment. Inductions in the expression of apoptotic protein p53 and PUMA as well as autophagic protein DRAM, LC3 and Beclin 1 were detected with Western blotting analysis. SN50-treated cells exhibited punctuate microtubule-associated protein 1 LC3 in immunoreactivity and MDC-labeled vesicles increased after treatment of SN50 by MDC staining. Collapse of mitochondrial membrane potential Δψ were detected for 6 to 24 h after SN50 treatment. SN50-induced increases in PUMA, DRAM, LC3 and Beclin 1 and cell death were blocked by the p53 specific inhibitor pifithrin-α. CONCLUSION: The anti-tumor activity of NF-κB inhibitors is associated with p53-mediated activation of autophagy.

Effects of LY294002 on the invasiveness of human gastric cancer in vivo in nude mice.

AIM: To investigate the effects of class I phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 on the invasiveness and related mechanisms of implanted tumors of SGC7901 human gastric carcinoma cells in nude mice. METHODS: Nude mice were randomly divided into model control groups and LY294002 treatment groups. On days 5, 10 and 15 after treatment, the inhibitory rate of tumor growth, pathological changes in tumor specimens, expression levels of matrix metalloproteinase (MMP)-2, MMP-9, CD34 [representing microvessel density (MVD)] and vascular endothelial growth factor (VEGF), as well as apoptosis indexes in tumor samples were observed. RESULTS: In this study, we showed that treating the tumors with LY294002 could significantly inhibit carcinoma growth by 11.3%, 29.4% and 36.7%, after 5, 10 and 15 d, respectively, compared to the control group. Hematoxylin & eosin staining indicated that the rate of inhibition increased progressively (23.51% +/- 3.11%, 43.20% +/- 3.27% and 63.28% +/- 2.10% at 5, 10 and 15 d, respectively) along with apoptosis. The expression of MMP-2 was also downregulated (from 71.4% +/- 1.6% to 47.9% +/- 0.7%, 31.9% +/- 0.9% and 7.9% +/- 0.7%). The same effects were observed in MMP-9 protein expression (from 49.4% +/- 1.5% to 36.9% +/- 0.4%, 23.5% +/- 0.9% and 7.7% +/- 0.6%), the mean MVD (from 51.2% +/- 3.1% to 41.9% +/- 1.5%, 30.9% +/- 1.7% and 14.9% +/- 0.8%), and the expression of VEGF (from 47.2% +/- 3.1% to 25.9% +/- 0.5%, 18.6% +/- 1.2% and 5.1% +/- 0.9%) by immunohistochemical staining. CONCLUSION: The class I PI3K inhibitor LY294002 could inhibit the invasiveness of gastric cancer cells by downregulating the expression of MMP-2, MMP-9, and VEGF, and reducing MVD.

LY294002 induces p53-dependent apoptosis of SGC7901 gastric cancer cells.

AIM: To study the effects of LY294002, an inhibitor of class I phosphatidylinositol 3-kinase (PI3K), on proliferation and apoptosis of SGC7901 gastric cancer cells. METHODS: The MTT assay was used to determine the cytotoxic effects of LY294002. Cell cycle distribution was analyzed using flow cytometry and apoptosis was assessed using flow cytometry analysis after staining DNA with propidium iodide. Mitochondrial membrane potential was measured using the fluorescent probe JC-1. Expression of p53 and PUMA was determined using real-time RT-PCR and Western blotting analysis. RESULTS: The viability of SGC7901 cells was significantly reduced by LY294002 treatment. Expression of p53 and PUMA was induced, and mitochondrial membrane potential collapsed after treatment with LY294002. LY294002 induced apoptotic cell death. CONCLUSION: Activation of the p53 pathway is involved in LY294002-induced SGC7901 cell death.