AIM: To investigate the expression pattern of epithelial cell adhesion molecule (Ep-CAM) on normal and malignant colon tissues to evaluate its diagnostic and therapeutic significance.METHODS: cDNA encoding Ep-CAv extr...AIM: To investigate the expression pattern of epithelial cell adhesion molecule (Ep-CAM) on normal and malignant colon tissues to evaluate its diagnostic and therapeutic significance.METHODS: cDNA encoding Ep-CAv extracellular domain was cloned by reverse transcription-polymerase chain reaction (RT-PCR) from excised malignant colon tissues and inserted into a glutathione S-transferase (GST)-tagged vector. EpCAM-GST fusion protein was induced by isopropyl-β-D-thiogalactopyranoside (IPTG) and purified with glutathionesepharose. The Ep-CAM-GST fusion protein was mixed with Freund's adjuvant and Balb/c mice were immunized with it. Sp2/0 myeloma cells were fused with the spleen cells of the immunized mice. After having selected by indirect ELISA, the anti-Ep-CAM monoclonal antibodies (NAbs) were generated and the corresponding ascites were obtained.Finally, the human colon carcinoma tissue array prepared from seventy individual patients was stained with the antiEp-CAM NAbs.RESULTS: The isolated Ep-CAM cDNA sequence was identical to the data in GenBank. The expressed fusion protein was almost soluble and had a molecular weight (NW) of 53 ku.Four NAbs against Ep-CAM were obtained and designated as FMU-Ep1, FMU-Ep2, FMU-Ep3 and FMU-Ep4 respectively.Among them, FMU-Ep4 could recognize the natural EpCAM on Colo205 and SW480 cells, and all of them could be used for immunohistochemical staining of tissue sections.It was found that Ep-CAM was distributed differently in normal and various malignant colon tissues, including squamous cell carcinoma, signet-ring cell carcinoma and adenocarcinoma.In normal colon gland epithelia, Ep-CAM antigen was mainly distributed on the basolateral membrane and in the region between the basolateral membrane and the cytoplastic part near the nuclei, whereas the expression pattern of colon malignancies was mainly on the whole surface of epithelia and the expression was much higher than the normal colon tissues. The staining pattern of tissue array showed in adenocarcinoma and papillary adenocarcinoma, and the expression of Ep-CAM was increased from grade Ⅰ to grade Ⅲ.CONCLUSION: NAbs against Ep-CAM might be useful for research on the structure and function of Ep-CAM and may have diagnostic and therapeutic value to various colon carcinomas.展开更多
AIM: To observe the localization of TRAIL/TRAIR (DR4, DR5,DcR1, DcR2) in the fetal pancreas.METHODS: Fetal pancreas of 32 weeks of pregnancy wereobtained from induced abortions, embedded in paraffin, and4-μm sections...AIM: To observe the localization of TRAIL/TRAIR (DR4, DR5,DcR1, DcR2) in the fetal pancreas.METHODS: Fetal pancreas of 32 weeks of pregnancy wereobtained from induced abortions, embedded in paraffin, and4-μm sections were prepared. The localization of TRAIL/TRAILR in fetal pancreas was investigated by fluorescenceimmunohistochemical method combined with laser scanningconfocal microscopy.RESULTS: TRAIL immunoreactive cells were mainly locatedon the periphery of the pancreas islets. There were a fewDcR1 and DcR2 positive cells whereas there were noimmunoreactive cells of DR4 and DR5 in the pancreas islets.In the acini and the ducts of the exocrine pancreas therewere no TRAIL/TRAILR immunoreactive cells.CONCLUSION: This study not only describes thedistribution of TRAIL/TRAILR in the fetal pancreas, but alsoprovides a morphological basis for deducing the functionof TRAIL/TRAILR in pancreas, suggesting that in normalpancreatic islets, the pancreatic cells are resistant towardsapoptosis too.展开更多
基金Supported by the National Key Basic Research Special Funds (NKBRSF), No. 2001CB510004
文摘AIM: To investigate the expression pattern of epithelial cell adhesion molecule (Ep-CAM) on normal and malignant colon tissues to evaluate its diagnostic and therapeutic significance.METHODS: cDNA encoding Ep-CAv extracellular domain was cloned by reverse transcription-polymerase chain reaction (RT-PCR) from excised malignant colon tissues and inserted into a glutathione S-transferase (GST)-tagged vector. EpCAM-GST fusion protein was induced by isopropyl-β-D-thiogalactopyranoside (IPTG) and purified with glutathionesepharose. The Ep-CAM-GST fusion protein was mixed with Freund's adjuvant and Balb/c mice were immunized with it. Sp2/0 myeloma cells were fused with the spleen cells of the immunized mice. After having selected by indirect ELISA, the anti-Ep-CAM monoclonal antibodies (NAbs) were generated and the corresponding ascites were obtained.Finally, the human colon carcinoma tissue array prepared from seventy individual patients was stained with the antiEp-CAM NAbs.RESULTS: The isolated Ep-CAM cDNA sequence was identical to the data in GenBank. The expressed fusion protein was almost soluble and had a molecular weight (NW) of 53 ku.Four NAbs against Ep-CAM were obtained and designated as FMU-Ep1, FMU-Ep2, FMU-Ep3 and FMU-Ep4 respectively.Among them, FMU-Ep4 could recognize the natural EpCAM on Colo205 and SW480 cells, and all of them could be used for immunohistochemical staining of tissue sections.It was found that Ep-CAM was distributed differently in normal and various malignant colon tissues, including squamous cell carcinoma, signet-ring cell carcinoma and adenocarcinoma.In normal colon gland epithelia, Ep-CAM antigen was mainly distributed on the basolateral membrane and in the region between the basolateral membrane and the cytoplastic part near the nuclei, whereas the expression pattern of colon malignancies was mainly on the whole surface of epithelia and the expression was much higher than the normal colon tissues. The staining pattern of tissue array showed in adenocarcinoma and papillary adenocarcinoma, and the expression of Ep-CAM was increased from grade Ⅰ to grade Ⅲ.CONCLUSION: NAbs against Ep-CAM might be useful for research on the structure and function of Ep-CAM and may have diagnostic and therapeutic value to various colon carcinomas.
基金the grants of the National Key Basic Research Program of China,No.2001CB510004
文摘AIM: To observe the localization of TRAIL/TRAIR (DR4, DR5,DcR1, DcR2) in the fetal pancreas.METHODS: Fetal pancreas of 32 weeks of pregnancy wereobtained from induced abortions, embedded in paraffin, and4-μm sections were prepared. The localization of TRAIL/TRAILR in fetal pancreas was investigated by fluorescenceimmunohistochemical method combined with laser scanningconfocal microscopy.RESULTS: TRAIL immunoreactive cells were mainly locatedon the periphery of the pancreas islets. There were a fewDcR1 and DcR2 positive cells whereas there were noimmunoreactive cells of DR4 and DR5 in the pancreas islets.In the acini and the ducts of the exocrine pancreas therewere no TRAIL/TRAILR immunoreactive cells.CONCLUSION: This study not only describes thedistribution of TRAIL/TRAILR in the fetal pancreas, but alsoprovides a morphological basis for deducing the functionof TRAIL/TRAILR in pancreas, suggesting that in normalpancreatic islets, the pancreatic cells are resistant towardsapoptosis too.
