Breast cancer is one of the most common causes of death for women, and about 90% breast cancer patients died of tumor metastasis. Sadly, currently there is no cure case for metastatic breast cancer.

Chemotherapy is still the main treatment for metastasis of breast cancer, but it is not able to effectively differentiate cancer cells from normal cells, which leads to inefficient therapy and severe systemic side effects and vastly limits the clinical application of chemotherapy.

To address the problem, Prof. LI Yaping's group from Shanghai Institute of Materia Medica of Chinese Academy of Sciences has constructed a nanodevice with selective toxicity towards cancer cells and good compatibility in the body. The work provides a new strategy of tumor cells-selective chemotherapy. The finding was published in Advanced Functional Materials.

In the study, the scientists linked a chemotherapeutic agent, docetaxel (DTX), with a kind of glycosaminoglycan, heparan sulfate (HS), to obtain a new material, HS-DTX, which formed micelles automatically in water, and the toxicity of DTX was concealed. Then red blood cell (RBC) membranes were isolated from the blood of mice. rHS-DTX was prepared by coating HS-DTX with RBCm. When injected into the body, rHS-DTX disguised as RBC in blood circulation. Therefore, it escaped from the clearance by the immune system and had more chances to accumulate in the primary tumor and metastases.

Since the heparanase (Hpa) concentration in tumor cells is much higher than that in normal cells, after rHS-DTX entered tumor cells, HS was degraded by Hpa and DTX was set free to kill tumor cells. While in normal cells, HS-DTX linked together and showed low toxicity.

The experiments in metastatic breast cancer mice model proved that rHS-DTX significantly inhibited the growth and metastasis of tumor, inducing no severe toxicity in the major organs and blood. Thus the scientists concluded that rHS-DTX can be a powerful tool for treating breast cancer.

This work was funded by the National Basic Research Program of China, the National Natural Science Foundation of China, the Key Scientific Research Program of the Chinese Academy of Sciences (CAS), and the Youth Innovation Promotion Association of Chinese Academy of Sciences (CAS).

The article link: https://doi.org/10.1002/adfm.201707289

Therapy of metastatic breast cancer with rHS-DTX. (Image by LANG Tianqun)

Contact person:
Prof. LI Yaping
Email: ypli@simm.ac.cn

(Credit: YIN Qi; Editor: PAN Peihua)