| Background Gastric carcinoma is the most common human malignancies,morbidity and mortality in our country home of the first types of tumors.Clinically,most of the early gastric cancer has no symptoms or no typical symptoms,which has brought difficulty to early diagnosis;on the clinical the majority of doctors' offices visiting of patients belong to advanced gastric cancer,which lose the opportunity to surgery or relapse easily after operation.As a result,improving the quality of life of patients with gastric cancer and disease-free survival of the chemotherapy appears to be very important.At present,common chemotherapeutics have more drug side effects,and the efficacy below the mark.Therefore,it is an urgent need to resolve the issue that the gastrointestinal cancer prevention and treatment need research and develop the new of safe and effective chemotherapy drugs.Cell proliferation and apoptosis in cell biology are two important aspects of behavior.The incidence of tumor cell proliferation and apoptosis is caused by out of control.In recent years,it has attracted great attention about the expression of Fas and FasL in the digestive tract tumors,especially in precancerous lesions of gastric and gastric cancer, and its relationship with cell apoptosis.Fas as important death receptor of cell surface,binding FasL and activation of apoptosis signal transduction is an important way of induced apoptosis.FasL and Fas bind through intracytoplasmic Fas-associated death domain protein(FADD),that interact to activate caspase-8 zymogen to further caspase activation together a variety of class reaction,eventually leading to apoptosis.Past research has proved the expression of FasL in gastric cancer and gastric precancerous lesions,which can mediate gastric cancer and gastric precancerous lesions cell with expression of Fas apoptosis and mediate TIL cells expression of Fas apoptosis in gastric precancerous lesions and gastric cancer tissue,which make the gastric cancer cells escape the body's own immune clearance and become a potential biological basis of genesis and survival and development of gastric cancer.To depth study expression of Fas and FasL in gastric cancer and local lymph node tissues is of great significance to further clarify the Fas system in apoptosis of gastric cancer,development and immune escape mechanisms and provide experimental evidence for prevention and treatment.NSAIDS can reduce the gastrointestinal cancer risk,which has become another hot spot in recent years in the field of prevention and treatment tumor.Abroad,a number of large-scale epidemiological studies, animal experiments and clinical studies have found that long-term use of the law of non-steroidal anti-inflammatory drugs(NSAIDS) can reduce the risk of the incidence of colon cancer.Our preliminary studies found that indomethacin(IN) and celecoxib have anti-colon tumor cell proliferation effect.Traditional NSAIDs,such as IN,can inhibit COX-2 at the same time COX-1,and thus the gastrointestinal tract and kidneys organ damage because of long-term use will have to limit its wide range and long-term of clinical applications.New NSAIDs,selectively inhibiting COX-2,are both anti-tumor effect and avoiding the side effects.Oncology experts pay much attention to whether selective COX-2 inhibitors inhibit gastric cancer cell proliferation and induce apoptosis or not.Some study at home and abroad found that celecoxib has inhibited apoptosis and proliferation in gastric cancer cell,its role is limited to the molecular mechanism of celecoxib inhibition the activity of cyclooxygenase-2.Some studies show that COX-2 inhibitors can inhibit the activity of cyclooxygenase -2 and reduce the release of prostaglandin E2,thereby inhibiting cell proliferation and induced apoptosis.However, selective COX-2 inhibitors on gastric cancer cell proliferation and related regulatory genes p16 and p21 expression,and apoptosis-related proteins Fas,FasL and Bcl-2 protein expression in small studies.We explore the selective COX-2 inhibitor celecoxib on gastric cancer cells BGC-823 anti-tumor effect from the cell cycle regulation and control system,Fas, FasL system and the apoptosis signaling pathway level,and so on, "Stereo" and systematically research stomach tumor cell proliferation and apoptosis regulation and control network,revealed a selective COX-2 inhibitor celecoxib inhibited gastric cancer cell proliferation and apoptosis regulation and control mechanism,provided the experimental basis for clinical applications a selective COX-2 inhibitor anti-gastric tumors including celecoxib,as well as to provide new ideas for detecting new molecular targets.Chapterâ… Effects of Celeeoxib on cell proliferation in human gastric cancer cell line BGC-823 and expression of p16 and p21Objectives:To explore the effects of Celecoxib on cell proliferation of human gastric cancer cell line BGC-823 and expression of cell cycle regulation -related factor p16 and p21.Methods:MTT assay were used to quantify the influence of Celecoxib on the proliferation of gastric cancer cell line BGC-823.Flow cytometry(FCM) were used to measure the influence of Celecoxib on cell cycle of difference concentration celecoxib on BGC-823 cell.The expressions of p16 and p21 mRNA with difference concentration celecoxib on BGC-823 cell were observed by RT-PCR analysis.Results:â‘ Celecoxib concentration 20,40,60,80,100,120μmol/L respectively,cultivating for 24hr the inhibition rate(%) were 7.63±2.66,13.33±0.95,18.83±9.10,24.63±1.55,33.20±1.14,55.00±6.50; 48hr when the inhibition rate(%),respectively:10.72±3.20,25.16±2.70,37.22±1.60,42.42±2.41,46.79±4.57,91.64±4.14;72hr when the inhibition rate(%),respectively:10.91±1.61,31.39±3.20,54.82±1.25,62.41±5.51,74.88±1.02,98.17±0.69Difference concentration celecoxib inhibited the cell growth rates of gastric cancer cell line BGC-823 in a time -dependent and concentration -dependent manner.â‘¡FCM showed:Celecoxib concentration 20,40,60,80,100,120μmol/L respectively,the proportion of G1 phase cells were 0.603±0.016,0.643±0.006,0.671±0.005,0.708±0.008,0.750±0.007,0.787±0.006;S phase cell ratio were 0.307±0.006,0.223±0.003,0.209±0.005,0.193±0.015,0.157±0.005,0.122±0.006;Celecoxib increased the proportion of cells in G1 phase,whereas decreased the proportion of cells in the S phase in a concentration-dependent manner from 0 to 100μmol/L in BGC-823 cells.The proportion of cells between various concentration celecoxib groups has significant differences,(P＜0.05).â‘¢RT-PCR results showed that there were expressions of p16 and p21 amplified product by different concentrations of celecoxib on BGC-823 cells, relative abundance of expressions of p16 and p21 amplified product increased with celecoxib concentration.Celecoxib concentration 20,40,60,80,100,120μmol/L respectively,p16 PCR products relative abundance,respectively:0.223±0.006,0.296±0.012,0.381±0.008, 0.438±0.017,0.494±0.002,0.663±0.068:p21 PCR products relative abundance,respectively:0.435±0.045,0.642±0.098,0.730±0.014, 0.813±0.069,0.907±0.058,1.030±0.051.The relative abundance of p16 and p21 between various concentration celecoxib groups has significant differences,(P＜0.05). Conclusions:â‘ Celecoxib inhibited BGC-823 gastric cancer cell proliferation,showing time and dose-dependent manner.â‘¡Celecoxib inhibited BGC-823 gastric cancer cell proliferation;G1 phase cells increased and S phase cells decrease in celecoxib on BGC-823gastric cancer cell,which block cell cycle in G1 phase.â‘¢Celecoxib inhibited cell cycle progress of BGC-823 gastric cancer cell,which may be associated with up-regulation of the expression of cell cycle dependent protein kinase p16 and p21,and alteration cell cycle progression.Chapterâ…¡Effects of Celecoxib on cell apoptosis in human gastric cancer cell line BGC-823 and expression of Fas,FasL and Bcl-2Objectives:To explore the effect of Celecoxib on cell apoptosis of human gastric cancer cell line BGC-823 and expression of Fas,FasL and Bcl-2.Methods:Flow cytometry was used to quantify the influence of Celecoxib on the apoptosis of gastric cancer cell line BGC-823.The expressions of Fas,FasL,bcl-2 proteins were observed by Western blot analysis.Results:â‘ Flow cytometry found that the ratio of apoptotic cells increased with the concentration of celecoxib increased;Celecoxib concentration at 0,20,40,60,80100μmol / L,ratio of apoptotic cells(%) were:0.503±0.018,5.870±0.325,11.396±0.267,17.567±0.376, 24.439±0.326,52.933±2.575.The apoptotic rates of cells between various concentration celecoxib groups has significant differences,(P＜0.05).â‘¡Western blotting analysis showed:Celecoxib concentration at 0,20,40,60,80,100μmol / L,cultivating for 48h on BGC-823 gastric cancer cells,Relative content of Fas protein were 0.1113±0.0037,0.1017±0.0065,0.1975±0.0100,0.3297±0.0053,0.4595±0.0045,0.5204±0.0148;Relative content of FasL protein were 0.8070±0.0268,0.7311±0.0780,0.6254±0.0501,0.5465±0.0180,0.4378±0.0081,0.3760±0.0034;Relative content of Bcl-2 protein were 0.5448±0.0049,0.5213±0.0326,0.4256±0.0421,0.3934±0.0305,0.2659±0.0121,0.2294±0.0081.The expression of Fas was up-regulated,whereas the expressions of FasL and bcl-2 proteins were down-regulated in a concentration-dependent manner from 0 to 100μmol/L in gastric cancer cell line BGC-823.The expressions of Fas,FasL and Bcl-2 proteins between various concentration celecoxib groups have significant differences(P＜0.05,respsctively).Conclusions:â‘ Celecoxib-induced gastric cancer BGC-823 cell apoptosis,to a certain range of dose-dependent manner.â‘¡At a certain celecoxib concentration scope, Fas protein increased and FasL,Bcl-2 protein reduced were dose-dependent manner.â‘¢Celecoxib induced cell apoptosis in gastric cancer cell line BGC-823,which may be associated with up-regulation of the expressions of Fas protein and down-regulated of the expressions of FasL and bcl-2 protein. Chapterâ…¢Expression significance of Fas and FasL in gastric cancer tissues and local lymph nodes tissuesObjective:To investigate the relationship between the expression of Fas and FasL protein with genesis,development and transfer of gastric cancer.Methods:FasL and Fas expression of 64 cases gastric cancer and 20 cases normal gastric tissue were studied by immunohistochemistry, and analysis the relationship between their age,gender,pathological subtype and lymph node metastasis with FasL and Fas expression.Results:â‘ Expression of Fas protein in normal gastric tissue is high, expression of Fas protein in gastric cancer tissue is low.Expression of FasL protein in normal gastric tissue is low;expression of FasL protein in gastric cancer tissue is high.The positive expressions between the two groups have significant differences,(P<0.001).â‘¡Expression of Fas in infringement lymph node tissue is high;Expression of Fas in non-infringement lymph node tissues is low.Fas positive expressions between the two groups have significant differences,(P=0.003).FasL positive expression between the two groups lymph tissues have no difference,(P=0.593).â‘¢Expression of Fas protein in highly and moderately differentiated gastric cancer tissue is high;Expression of Fas protein in poorly differentiated gastric cancer tissue is low.Expression of FasL protein in highly and moderately differentiated gastric cancer tissue is low;Expression of FasL protein in poorly differentiated gastric cancer tissue is high.The positive expressions between the two groups have significant differences,(P=0.015 and P=0.021,respectively).â‘£There is no significant relationship between age,sex and whether or not lymph node metastases with expression of Fas and FasL in gastric cancer.⑤There was a significant difference between Fas and FasL positive expression rate in gastric cancer(P＜0.001);both the expression of non-linear correlation(rs=-0.425,P=0.575).Conclusions:â‘ Fas expression in gastric cancer down-regulation,FasL expression in gastric cancer up-regulation.â‘¡Fas expression in infringement lymph node tissue up-regulation,in non-infringement lymph node tissues down-regulation.â‘¢Fas expressions in the well-differentiated gastric cancer were higher than it in poorly differentiated gastric cancer;FasL expressions in the well-differentiated gastric cancer tissues were lower than it in poorly differentiated gastric cancer.
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