乳腺癌是女性常见的恶性肿瘤，发病率高且易复发转移。我们前期通过小样本量的免疫组化检测，发现肿瘤相关糖抗原Tn和sialyl-Tn抗原在人乳腺癌中异常高表达，初步确立其与乳腺癌的一些临床特征有相关性，同时也发现了参与Tn抗原表达的关键调控基因（Cosmc、T-synthase）在Tn阳性和Tn阴性乳腺癌中存在表达差异。鉴于人乳腺癌中Tn/sialyl-Tn抗原异常表达的机制尚不清楚，本课题拟研究：（1）Tn/sialyl-Tn抗原在人乳腺癌病灶的表达及其与临床病理特征和预后的相关性；（2）通过体内外试验明确O-聚糖缺陷（即Tn抗原暴露）对乳腺癌细胞生物学功能的影响；（3）采用目标区域捕获测序、甲基化分析等方法明确乳腺癌中Tn抗原异常表达的机制。本课题将揭示Tn/sialyl-Tn抗原在人乳腺癌发生发展中的地位及机制，为寻找对乳腺癌有早期诊断、预后价值的生物标记物及治疗靶点提供重要理论基础。

Breast cancer is a common malignancy in women, with high incidence and recurrence and metastasis. We detected the tumor-associated carbohydrate antigen Tn and sialyl-Tn antigens in human breast cancer by early immunohistochemical detection of small sample size. It was found that Tn and sialyl-Tn antigens were related to some clinical features of breast cancer, and the key regulatory genes (Cosmc, T-synthase) involved in the expression of Tn antigen have differences in Tn-positive and Tn-negative breast cancer. Tn/sialyl-Tn antigen is closely related to the development and progression of breast cancer, but its molecular mechanism is unclear. Based on our previous work, the subjects are to be studied as follows: (1) explore the expression of Tn/sialyl-Tn antigen in human breast cancer and its correlation with clinicopathological features and prognosis with large sample size; (2) The effect of O-glycan deficiency on the biological function of breast cancer cells was clarified by in vitro and in vivo experiments; (3) The molecular mechanism of the abnormal expression of Tn antigen was clarified by target-region capture sequence and methylation analysis. Our research will uncover the status and molecular mechanism of Tn/sialyl-Tn antigen in the development and progression of human breast cancer and provide some clues for their early diagnosis and targeted therapies in clinical practice.