CNTN-1为一种神经细胞粘附分子，参与介导神经系统的生长发育及多种细胞功能，是近年来发现最有潜力参与细胞分化的细胞分子。Sox-2是一种与SRY蛋白相关的含有HMGbox的转录因子。Sox-2作为“干性因子”在胚胎干细胞中维持自我更新及在多项分化过程中起决定性作用，结合肿瘤干细胞学说，使其成为在肿瘤分子学领域研究热点，现有的研究证明原癌基因CNTN-1、Sox-2在促进肿瘤发生发展中起一定作用，但其确切作用机制尚不清楚。本研究以关键原癌基因CNTN-1、Sox-2为突破点，阐述其在乳腺肿瘤发生及侵袭转移的关键分子机制，通过观察CNTN1/Sox-2在犬乳腺肿瘤病理组织及相关细胞系中的表达情况，采用基因干扰技术通过使其沉默或过表达，通过体内外实验，探究上述基因与肿瘤细胞、肿瘤干细胞增殖转移和成瘤能力之间的相互关系，为揭示乳腺肿瘤的生成、转移机制及为肿瘤有效预防提供理论依据。

It was a hot and key point to research for effective anti-tumor molecular mechanism of development, invasion, metastasis in recently. CNTN-1 is a kind of neural cell adhesion molecule involved in growth and development, in most cytokines involved in cell differentiation it was potential and a variety of cellular functions mediated by the nervous system. Sox-2 is a transcription factor containing HMGbox and related to SRY protein. Some researchers showed that cell in early embryonic germ expression Sox-2. Sox-2 as a "stem factor" can maintain self-renewal and multi-directional differentiation plays an important role in the progress of embryonic stem cells, combined with the theory of cancer stem cells, which makes it become the hot research field in tumor molecular biology. The current studies had proved that the proto oncogene CNTN-1, Sox-2 and tumor has certain correlation, but its exact mechanism of action is not clear. In this study, with the key CNTN-1 and Sox-2 as a breakthrough point to elaborates the molecular mechanism in the development of mammary gland tumorigenesis, invasion and metastasis as the scientific objectives, to observe the expression of CNTN-1/Sox-2 in canine mammary gland tumor pathological tissue and tumor cell lines, to find the relationship between the gene of CNTN-1/Sox-2 deletion, over-expression and by RNA interference technology explore the gene and tumor cells, tumor stem cell invasion, metastasis, proliferation and tumorigenic. After study for these, we will to understand well from the fundamentally the key role played by CNTN-1/Sox-2 between in the breast primary tumor and metastasis, and further analysis sensitivity of chemotherapy drugs it with tamoxifen, and to provide a theoretical basis for the prevention and control of breast tumor effectively.