The Role Of Indoleamine 2,3-dioxygenase2(IDO2) In The Mouse Melanoma Model Of Lung Metastasis

Object:Detection the expression of IDO1 and IDO2 respectively in normal mice and in mice bearing melanoma tissues; To investigate effection of indole 2,3-dioxygenase 2(IDO2) inhibitor L-1-methyl-tryptophan(L-1-MT) on mouse melanoma lung metastasis; Vitro expriment observate how L-1-MT and silence tumor cell IDO2 effect on the cell characteristics of proliferation,migration and invasion. Methods:1、C57BL/6 male mice were inoculated subcutaneously melanoma B16-BL6 5×105 cells/mouse, the mice were sacrificed at different time and collect various organs and tissues, using RT-PCR technology to detect tissue IDO1 IDO2 expression levels of mRNA;2、After C57BL/6 mice were inoculated subcutaneously B16-BL6 melanoma cell, intravenous injection B16-BL6 melanoma cell again to establish lung metastasis model. Chemical applications IDO2 inhibitor L-1-MT in tumor-bearing mice intervention, observed lung tumor cases and statistics of lung tumor nodules;3、Applications IDO chemical inhibitors L-1-MT and IDO2 siRNA respectively processing cultured melanoma cells B16-BL6. qPCR to detection efficiency of IDO2 silence, and healing assay, transwell cell migration assay was observed on tumor cell migration; colony formation assay was observed on proliferation of tumor cell; transwell cell invasion assay was observed on tumor cell invasion; Results:1. IDO1 expression detected by normal mice and tumor-bearing mice were in the colon and epididymis, no significant difference, And IDO2 expression detect except in normal and tumor-bearing mice liver, kidney, brain, cerebellum, epididymis expression, but also detect in the tumor-bearing mice spleen, lung, colon and thymus, metastasis were not found in the above-mentioned mice.2. Oral L-1-MT treatment inhibits C57BL/6 mice subcutaneous melanoma growth, while the melanoma lung metastasis model mice lung tumor formation was significantly reduced.3. Vitro experiments: L-1-MT and silence cell IDO2 all make B16-BL6 cells migrate slower scratches, monoclonal form a low density, reducing the number of Transwell cell migration, reducing the number of Transwell cell invasion. Conclusion:1. Abnormal expression of IDO2 in melanoma bearing mice tissue promotes tumor lung metastasis.2. IDO2 affect melanoma cell B16-BL6 proliferation, migration, and invasion.