| BACKGROUND:The malignant neoplasms of digestive system are among the crucial diseases that threaten human's health in the world. The incidence and mortality of those diseases rank top list in the malignant diseases. For example, pancreatic cancer is one of the most lethal human cancers. It is hard to diagnosed and progresses rapidly with worst prognosis. The incidence of pancreatic cancer is almost equal to the mortality, so it is called " the intractable fortress of 21st century". Make another example like colorectal cancer, the incidence grew fast in recent years with the development of people's life standard so that it has become the most common cancer among the malignant tumors of digestive system. But the treatment remains not optimistic. The worse prognosis of digestive system tumors is partly because of the later disease period, the lower respectability and the recurrence even the metastases. The surgical resection is still the primary choice for the treatment of malignant tumors of digestive system. So early detection and early diagnosis are the best way to solve the question that how to promote the radical resection rate. Even though the most malignant pancreatic cancer, the survival can be last for a longer time after the tumor has been resected in the early stage. We got many weapons to diagnose malignant tumors during their early stage, but less effective. Most methods used in the clinical practice such as CEA, CA19-9 are not for the early detection but just can screen the early phase in the advance stage. It is very urgent to develop some practical, cheap and sensitive early detection methods. The serum tumor biomarker test is a very effective tumor diagnostic method, and maybe become one of the early detection methods in the future. Our lab has finished a study about screening and identification of immunogenic membrane antigens in pancreatic cancer using proteomics. We chose some potential membrane antigens that may have some relationship with the genesis and existence of pancreatic cancer. Among them, COMT and CHCHD3 were found expressed in human pancreatic cancer cell lines SW1990, AsPc and P3 in the gene and protein level. Compared with normal pancreatic tissue, COMT were found more expressed in the pancreatic cancer cell lines. Further study is needed to prove the role of these two proteins in the pancreatic cancer, and expand the study to the tumors of other digestive system organs to understand the expression level. This is the basis for the further study of tumor marker.OBJECTIVE:In order to verify the expression of COMT and CHCHD3 in the tissue level of pancreatic cancer, insuloma and normal pancreatic tissue; To understand the expression of COMT and CHCHD3 in other malignant tumors of digestive system.METHODS:Make a deeper understand of COMT and CHCHD3 using bioinformation study. To know the genes'location, function, modulation and transcription, to explain the proteins'function in human body and what kind of influence they have on body. We kept samples of pancreatic cancer, insuloma, normal pancreatic tissue, hepatic cancer and normal hepatic tissue, gastric cancer and normal gastric mucosa, colorectal cancer and normal colorectal mucosa immediately after the samples were resected. The total RNA and total protein were extracted from the samples and then performed RT-PCR and western blot. Study the expression level and different expression between the tumors and normal tissues of all the groups. In tissue microarray, Using the immunohistochemistry to study the protein's staining location in cells, staining intensity, staining rate. RESULTS:1. There are single nucleotide polymorphisms in COMT gene. The coding proteins include membrane-bound COMT and soluble COMT. COMT can catabolize dopamine, adnephrin and arterenol and play an important role in the metabolism of catechol estrogens whose metabolism products show an inhibitive activity against cancer.2. It is still unclear about the function of CHCHD3 gene. Maybe it relates to PKA pathway, oxidative phosphorylation and signal pathways.3. RT-PCR results showed both COMT and CHCHD3 expressed in pancreatic cancer, insuloma and normal pancreatic tissue, but there was no significantly different between the groups.4. RT-PCR results showed both COMT and CHCHD3 expressed in hepatic cancer and normal hepatic tissue, but there was no significantly different between the groups.5. RT-PCR results showed both COMT and CHCHD3 expressed in gastric cancer and normal gastric mucosa, but there was no significantly different between the groups.6. RT-PCR results showed COMT expressed in colorectal cancer and normal colorectal mucosa, and was significantly over-expressed in the colorectal cancer compared with the normal colorectal mucosa (P<0.05). CHCHD3 expressed in colorectal cancer and normal colorectatl mucosa, but there was no significantly different between the groups.7. Western blot results showed MB-COMT,S-COMT and CHCHD3 protein expressed in pancreatic cancer, insuloma and normal pancreatic tissue, but there was no significantly different between the groups.8. Western blot results showed MB-COMT,S-COMT protein expressed in hepatic cancer and normal hepatic tissue, but there was no significantly different between the groups. CHCHD3 protein didn't express in the hepatic tissues.9. Western blot results showed MB-COMT and S-COMT protein expressed in gastric cancer and normal gastric mucosa, and was significantly down-expressed in the gastric cancer compared with the normal gastric mucosa (P<0.05). CHCHD3 protein didn't express in the gastric tissues.10.Western blot results showed MB-COMT and S-COMT protein expressed in colorectal cancer and normal colorectal mucosa, and S-COMT was significantly over-expressed in the colorectal cancer compared with the normal colorectal mucosa (P<0.05). MB-COMT was not significantly different between the groups. CHCHD3 protein didn't express in the colorectal tissues.11.Immunohistochemistry results showed COMT protein mostly stained in the cytoplasm and nuclear of the pancreatic cancer and normal pancreatic tissue. The staining rate of pancreatic cancer is significantly higher than the normal pancreatic tissue (P<0.05)12.Immunohistochemistry results showed COMT protein stained in the hepatic cancer and normal hepatic tissue, the staining rate showed no significantly different.13.Immunohistochemistry results showed COMT protein stained in the gastric cancer and normal gastric mucosa. The staining rate of normal gastric mucosa is significantly higher than the gastric cancer (P<0.05).14.Immunohistochemistry results showed COMT protein stained in the colorectal cancer and normal colorectal mucosa. The staining rate of the gastric cancer is significantly higher than the normal gastric mucosa (P<0.05)15.The CHCHD3 protein immunohistochemistry results showed there are no obviously stain in the pancreatic tissue, hepatic tissue, gastric tissue and colorectal tissue in the CHCHD3.CONCLUSIONS:1. COMT expresses in the pancreatic cancer, insuloma and normal pancreatic tissue, and is over-expressed in the pancreatic cancer compared with the normal pancreatic tissue.2. COMT expresses in the liver, stomach and colorectal tissue, and is over-expressed in the colorectal cancer and down-expressed in the gastric cancer compared with the normal tissue.3. CHCHD3 expresses expresses in the pancreatic cancer, insuloma and normal pancreatic tissue. |
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