Detection of Tn-antigen in breast and prostate cancer models by VVL-labeled red dye-doped nanoparticles

Aim: Fluorescence detection of breast and prostate cancer cells expressing Tn-antigen, a tumor marker, with Vicia villosa lectin (VVL)-labeled nanoparticles.
Materials & methods: Breast and prostate cancer cells engineered to express high levels of Tn-antigen and non-engineered controls were incubated with VVL-labeled or unlabeled red dye-doped silica-coated polystyrene nanoparticles. The binding to cells was studied with flow cytometry, confocal microscopy, and electron microscopy.
Results: Flow cytometry showed that the binding of VVL-labeled nanoparticles was significantly higher to Tn-antigen-expressing cancer cells than controls. Confocal microscopy demonstrated that particles bound to the cell surface. According to the correlative light and electron microscopy the particles bound mostly as aggregates.
Conclusion: VVL-labeled nanoparticles could provide a new tool for the detection of Tn-antigen-expressing breast and prostate cancer cells.
New VVL-labeled fluorescent red dye-doped silica-coated PS particles were developed and tested for detection of Tn-antigen, expressed only in malignant cells.
Breast and prostate cancer cell lines gene-engineered to express Tn-antigen at a high level and non-engineered counterparts were used as models.
The VVL-labeled particles bound specifically and effectively to Tn-antigen-expressing cells compared with their control cells as shown by flow cytometry.
Confocal microscopy showed that the VVL-labeled particles were bound to the cell surface of target cells, mostly as aggregates.
Further optimization to increase the intensity of the fluorescence and decrease the aggregation tendency of particles would help detect single particles.
The VVL-labeled nanoparticles could be used for recognizing Tn-antigen-expressing cells (circulatory tumor cells) in blood samples of breast and prostate cancer patients, biopsies, or cryosections of tumor samples. In the future, they could also be developed to function in vivo as carriers for targeted therapy of Tn-antigen-expressing cancer.

研究目的：采用野豌豆凝集素（Vicia villosa lectin, VVL）标记的纳米颗粒，对表达肿瘤标志物Tn抗原（Tn-antigen）的乳腺癌与前列腺癌细胞开展荧光检测。
材料与方法：将高表达Tn抗原（Tn-antigen）的基因工程乳腺癌、前列腺癌细胞及非工程化对照细胞，分别与VVL标记或未标记的红色染料掺杂二氧化硅包覆聚苯乙烯（polystyrene, PS）纳米颗粒共孵育。采用流式细胞术、共聚焦显微镜及电子显微镜对纳米颗粒与细胞的结合情况进行分析。
结果：流式细胞术结果显示，VVL标记纳米颗粒与表达Tn抗原的癌细胞的结合水平显著高于对照细胞。共聚焦显微镜观察证实，纳米颗粒可结合于细胞表面。关联光镜-电镜分析表明，纳米颗粒主要以聚集体形式结合于细胞。
结论：VVL标记的纳米颗粒可为表达Tn抗原的乳腺癌与前列腺癌细胞的检测提供全新工具。
本研究开发并测试了新型VVL标记的荧光红色染料掺杂二氧化硅包覆聚苯乙烯纳米颗粒，用于仅表达于恶性细胞的Tn抗原检测。
实验采用高表达Tn抗原的基因工程乳腺癌、前列腺癌细胞系，以及非工程化的对应细胞系作为研究模型。
流式细胞术结果证实，相较于对照细胞，VVL标记的纳米颗粒可特异性且高效地结合表达Tn抗原的细胞。
共聚焦显微镜观察显示，VVL标记的纳米颗粒主要以聚集体形式结合于靶细胞表面。
进一步优化以提升荧光强度、降低纳米颗粒聚集倾向，将有助于实现单颗粒检测。
VVL标记的纳米颗粒可用于乳腺癌及前列腺癌患者血液样本、活检组织或肿瘤样本冰冻切片中表达Tn抗原的细胞（循环肿瘤细胞，circulatory tumor cells）的识别。未来，该颗粒还可被开发为靶向递送载体，用于体内靶向治疗表达Tn抗原的癌症。