Chinese scientists have developed DNA nano-robots or can target killing breast cancer cells

:2019-06-13

According to Mayo Clinic data, about 20% of breast cancers produce abnormally high levels of HER2 protein, a specific protein called human epidermal growth factor receptor 2, which is a signal protein when displayed on the surface of cancer cells. It will help to control the proliferation, and it is also directly related to the poor prognosis of breast cancer patients. Recently, a research report published in the international journal Nano Letters, scientists from Sichuan University in China developed a research DNA nano-robot, which can effectively recognize HER2 protein on the surface of breast cancer cells and target the destruction of cancer cells.

Image credit: Adapted from Nano Letters 2019, DOI: 10.1021/acs.nanolett.9b01320

Current therapies for the treatment of HER2-positive breast cancer include monoclonal antibodies, such as trastuzumab, which bind to HER2 on the cell surface and introduce it into lysosomes for degradation; lowering HER2 levels can slow the proliferation of cancer cells And induce cell death, although the current monoclonal antibodies can cause cancer cell death, but these drugs still have serious side effects, and the cost of producing such drugs is very expensive.

In the previous study, the researcher Yunfeng Lin and colleagues identified a short DNA sequence called aptamer that recognizes and binds to HER2 and promotes it in the same way as monoclonal antibodies. Lysosomes degrade it. The aptamer is not stable in serum, so the researchers wanted to increase the aptamer's biostability and anticancer activity by observing whether additional DNA nanostructures (tFNA, tetrahedral backbone nucleic acid) were added.

In this study, the researchers designed a DNA nano-robot consisting of tFNA carrying an additional HER2 aptamer. When injected into mice, the time that the nano-robot remains in the body's blood is free. More than twice as many ligands, the researchers then added nano-robots to three breast cancer cell lines in culture dishes. It was found that nano-robots can only kill HER2-positive cell lines, and additional tFNAs can promote more The aptamer binds to the HER2 protein, thereby reducing the level of HER2 on the cell surface. Although nano-robots can be easily and inexpensively manufactured compared to monoclonal antibodies, further improvements are needed before they can be used in clinical treatment of breast cancer.

Original source: Wenjuan, MaYuxi, ZhanYuxin Zhang, et al. An Intelligent DNA Nanorobot with in Vitro Enhanced Protein Lysosomal Degradation of HER2, Nano Letters (2019) doi:10.1021/acs.nanolett.9b01320

Source: Bio Valley

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