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Identification and applications of MGAgs -------a group of novel gastric cancer associated antigens. Daiming Fan,Xueyong Zhang,Xitao Chen, ,Jialu Hu, Zhengxian Mu , Jun Ren, Jie Ding,Kaichun Wu. Institute of Digestive Diseases ,Xijing Hospital,
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Identification and applications of MGAgs-------a group of novel gastric cancer associated antigens Daiming Fan,Xueyong Zhang,Xitao Chen, ,Jialu Hu, Zhengxian Mu , Jun Ren, Jie Ding,Kaichun Wu Institute of Digestive Diseases ,Xijing Hospital, Fourth Military Medical University, Xi’an, China
Gastric cancer • Cause about 200,000 deaths annually • Early detection is not very easy • Mass survey is not feasible in China
The nature and immunohistochemical reactivity of MG series monoclonal antibodies Positive immunohistochemical reaction (% of cases) Ig subclass mAb Gastric cancer Colonic cancer Esophageal cancer Hepatic cancer Pancreatic cancer IgG1 IgG1 IgG2 IgG1 IgG1 IgG1 IgG1 IgG1 IgG1 IgM IgG1 IgG1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 MGa-5 MGa-7 MGa-9 MGa-11 MGb-1 MGb-2 MGc-1 MGd-1 MGe-1 MGe-2 MGg-1 MGg-2 28.6 66.7 72.6 36.0 68.8 42.0 50.0 70.0 20.0 46.7 44.8 67.6 16.7 25.0 25.0 0 16.7 0 9.1 0 0 40.9 20.5 32.3 25.0 22.2 30.0 16.7 0 14.3 0 0 0 55.6 0 13.0
Early detection of gastric cancer from precancerous lesions of stomach Retrogress Disappear Dysplasia Malignant transformation 4.0~19.0%
Follow up study of patients with dysplasia of gastric mucosa Dysplasia(90 cases) Stained by MGa-7 29 cases (+) 61 cases (-) 19 cases (41 months) 16 cases (42 months) No malignant change but 1 case became positive in staining Malignant change in 6 cases( 4 cases early gastric cancer)
Immunofluorescent diagnosis of cancer cells in malignant ascitic fluid or pleural effusion Methods Cases % Positive cases Immunoflourescent examination Conventional cytological examination 76 76 69 59 90.7 77.6 (P<0.05)
Radioimmunoimaging of tumor in vivo • The satisfactory imaging results were obtained in 73.3% of patients with gastric cancer(74/101). Metastatic tumor in liver, pancreas and supraclavicular lymph node could also be detected.
RII of Patients with Gastric Cancer Positive rate(%) 87.5(7/8) 75.9(22/29) 44.4(4/9) 50.0(2/4) 0 (0/7) 100(3/3) 131I-McAb MG7F(ab)2 MG7IgG MGd1 MGb2 MG11 MG7+MGd1
Detection of MGAgs for serological diagnosis of gastric cancer by immuno-PCR
RIA IRMA EIA Detection rate of gastric cancer using existing serological diagnostic methods
Reasons of low dectection rate for gastric cancer GC antigens 5% 95% Gastric lumen Blood circulation metabolized
? IF EIA RIA
Advantages and disadvantages of PCR • High sensitivity • 25,000 publications • Just for detection of nucleic acid
pXJ 19 MG7 -p XJ 19 pXJ 19
Sensitivity comparison of IPCR to EIA KATO III MG7AgP (x cell/ml) concentration IPCR 2 x 101 3.8 x 10-14 <0.001 EIA 2 x 105 3.0 x 10-11
Detection of MGAgs in different gastric diseases with IPCR Cases Positive % Gastric cancer 198 164 82.8 Peptic ulcer 78 6 7.7 Chronic gastritis 118 7 5.9 Donor 236 2 0.8
Positive results of MGAgs in different cancers with IPCR Cancer of Cases Positive % Stomach 198 164 82.8 Colon 90 40 44.4 Esophagus 86 15 17.4 Ovary 45 1 2.2 Lung 66 4 6.1 Liver 84 0 0 Uterus 27 0 0
Positive results of MGAgs in different histological patterns of gastric cancer Histological type Well differentiated Poorly differentiated Mucous adenocarcinoma Mucous cell carcinoma Cases Positive % 151 122 80.8 80 56 70.0 31 20 64.5 29 16 55.2
Positive results of MGAgs at different stages of gastric cancers Stage Cases Positive % Early 31 12 38.7 Advanced 116 91 78.4
Comparison of MGAgs to other tumor markers % 33.7 27.9 38.4 45.3 81.4 Gastric ca. (86) 29 24 33 39 70 Benign diseases (83) 10 6 6 7 7 Marker CEA CA50 CA19-9 TAG-72 MG7 Ag-IPCR % 12.0 7.2 7.2 8.4 8.4
抗癌药 1u 1000u 100u 10u MDR 10万种药
Total ratios 58% MDR1 10% MRP 12% LRP 10% GST-pi 36% Non-detected 42% 42% 58% 多个已知耐药相关分子在胃癌中的表达
MDR cells Sensitive cells Anticancer drug In vitro selection polyA+ RNAs proteins SSH/DD-PCR 2-D gel electrophoresis 30 proteins 83 genes
pH 10 - 3 IEF pH 10 - 3 IEF SDS --PAGE SGC7901/VCR SGC7901 Protein spectrums displayed by 2-D gel
11 11 12 11 12 19 19 19 SGC7901 SGC7901/VCR
3 specifically expressed in MDR cells 6 up-regulated in MDR cells 30 proteins 19 down-regulated in MDR cells 2 specifically expressed in sensitive cells
Accession number AF503367