| Trichinosis caused by Trichinella spiralis is one of the important zoonotic parasitic disease that harms human and animals'health. This disease spread worldwide which causes the huge economic loss and poses the huge threat on the public health. Therefore, the study of the trichinosis attracts much more attention from scholars all over the world.Cancer is the top-killer of human health. About 7.5 million people die in cancer and 8.7 million ones take cancer every year according to the statistics of the WHO. Gene-therapy, as a new treatment method, offers hope for the cure of cancer. In recent years, a lot of tumor treatment results indicate that some parasites and viruses can inhibit the tumors. Trichinella spiralis can promote immune cells to divide, proliferate and maturate. It also can make the organism to secret kinds of cell factors, enhance the organism's immunity conditions and suppress tumor cells'escaping. The anti-tumor effect of Trichinella spiralis has been confirmed by many experiments. But its anti-tumor molecular mechanism is still not clear and need to be further investigated.Along with the further study to the Trichinella spiralis, researchers discovered that Trichinella spiralis was beneficial to organisms. Rebecca and other scholars once put flu virus into the bodies of NIH rats infected by 500 trichina larvas during different times. The result showed that trichina larvas had an obvious inhibiting effect on the flu during the early stage of rats'infection. Moreover, a finding published in Neurology Yearbook suggested that the immunity reply process of the host to the secondary antigen was changed by the growing quantity or the enhancing action of regulative T cells produced after parasites infected the organism. Thus the course of multiple sclerosis encephalitis (MS) was altered. Many domestic reports indicated that Trichinella spiralis could enhance the hosts'power of resistance to tumors. Trichinella spiralis could inhibit the proliferation of tumor cells or the growth of tumor tissues transplanted into rats.Using the SSH methods to clone low abundance specific gene fragments of differential expression need high quality samples. If the samples are very complicated or there are few differences among their genes, the cloning background will happen with high frequency. In this experiment, anti-tumor animal models with remarkable phenotype changes were duplicated. These models accorded with the request of the SSH by check the tumor morphologic and immunological index. The successful construction of the model could offer reliable samples to Trichina spiralis anti-tuomr correlated difference genes. The established Balb/c mouse bearing cancer model could provide the ideal materials for constructing Trichina spiralis anti-tuomr difference gene expression library.The Part of Releated Genes expression cDNA library had been successfully set up with Trichinella Spiralis infection Induced on SP2/0 Myeloma Cell. The bearing cancer inoculated with Trichinella spiralis as the terester groups and the bearing cancer inoculated with Sodium Chloride as the driver groups, the RNA was separated, then the single and double strand cDNA were synthesized by inverse transcription. The cDNA was snipped into average size of 400-600bp fragments by the enzymes. The cDNA of driver group was divided into two groups and connected them with two kinds of adapters. Subtractive Hybridization and Suppression PCR were amplified for two times respectively with driven element cDNA. After the purification of the second time PCR product, the final product was linked to pMD-18T vector and transformed into E.coli DH5αcompetent cells. Finally, the high subtractive efficiency cDNA expression library of Trichina spiralis anti-tuomr correlated differential genes was constructed. 75 positive clones were obtained. The 30 randomly selected positive clones were identified by PCR. The results showed that the inserted fragments were ranged between 180-850bp.Using reverse Northern dot blot hybridization technique, 24 differential expression clones were abtained from the subtractive cDNA expression libraries. 20 ESTs sequences were gained by detecting the arrangement of clone. The valid sequences were submited to NCBI (http: //www. ncbi. nlm. nih. gov/VecScreen/VecScreen. html). Removed the vector and adapter sequences, The sequence homology search in the GenBank nr and EST database by BLASTn revealed that there were 27 high homology genes according to the classifying standards of EST, in which the functions of 12 genes were unknown. The high homology genes were seperated into 6 clusters according to function including signaling transduction and communication, cell structure and mobility, transporters, apoptosis, metabolism, translation and expression regulation. The function of MRPL41, NKTR, RbAp48, QRS and ANXA2 might relate to tumor inhibiting effects. They might play an important role in the process of Trichinella spiralis anti-tumors.The gene, named (MRPL41), plays an very important role in the process of apoptosis relying on the induction of p53 protein. While being lack of p53 protein, MRPL41 is capable of stabilizing p27Kip1 so that it reaches the arrest of the cell cycle in G1. In addition, the major function of Retinoblastoma binding protein 48 (RbAp48) is to regulate the cell cycle. RbAp48 belongs to the histone deacetylase compound recruited by Rb and represses the transcription of E2F by regulating the promoter gene. RbAp48 is usually considered as a tool which connects different molecular compounds and regulates the transcription inhibition of Rb. The natural killer tumor recognition protein (NKTR) can recognize tumor cells through the large granular lymphocyte (LGLs) and LGLs kill tumor cells through MHC. If the NKTR gene codogenic protein appears on LGLs'surface, the LGLs is competent of distinguishing and binding tumor cells easily. Such a feature exerts an indispensable influence on the cell toxic of the NK cells. NKTR has the unique protein multi-structures territory sparse rivercharacter N-Terminal including 3 kinds of histidines-like structural domains and 3 structural domains rich in ARG and SER. Although the direct action of recogniing NKTR protein target cell has not been confirmed. The NKTR gene will be a extremely useful tool in studying the origin of NK cell as well as the recognition of tumor cells. This research has supplied a basic foundation for illuminating the parasite anti-tumor. As a heterogeny tetramer in the cell, ANXA2 can stabilize the intermediate fibres in the cystoskeleton and cytolemma. Meanwhile, ANXA2 plays an important role in connecting the cell organs with cell-substances. On the other hand, the ANNEXINA2 protein has the capability of suppressing the migration and transfer of prostatic carcinoma cells. Its action to prostatic carcinoma may have a relationship with the ANNEXINA's action on cystoskeleton.At the MRPL41 gene mRNA of experimental groups and control groups, the result of relative fluorescent quantitation RT-PCR were indicated that The expression of MRPL41gene in expremental groups is not statistically different from that in control groups(p<0.05). MRPL41 gene expression up-regulation produce possibly a marked effect of anti-tumor. The tendencies in the expressive alteration of all verified differentially expressed genes were in coincidence with the result of gene expression profiles in Trichinella Spiralis Induced SP2/0 Myeloma Cell. It was suggested that the quality of the SSH library of development isreliable and its construction would lay the fundament for further screening differentially expressed genes in Trichinella Spiralis Induced SP2/0 Myeloma Cell and supplies some new ideas for the treatment of human tumors.
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