Stamps for nanospheres
Breast cancer is the most common form of cancer in women and one of the main causes of cancer death. 20-30% of breast cancer cases are poorly treatable HER2-positive form. HER2 is an epidermal Growth Factor Receptor (Human Epidermal Growth Factor Receptor 2). The HER2 protein lies in the cell membrane: one part protrudes into the cell, the other is located on the cell surface. As soon as a growth factor is attached to it, the extracellular part of HER2 binds into a heterodimer with another protein similar to itself (HER1 or HER3). This triggers a multi-stage cascade of signals in the cell that are involved in processes such as division, metastasis and growth of newly formed vessels supplying the tumor. HER2-positive tumor cells contain significantly higher concentrations of HER2. One of the modern tactics of therapy at an early stage of HER2-positive tumor is based on the binding of antibodies to HER2 to block dimerization.
A group of Chinese researchers led by Zhen Liu from Nanjing University has demonstrated the effectiveness of selective binding of nanoparticles and HER2 receptors in suppressing the growth of tumor cells.
They have developed molecular "imprinted" biocompatible polymer nanoparticles that recognize HER2 in the same way as antibodies and prevent dimerization.
"Imprinted" means that the mixture polymerizes into nanospheres in the presence of biomolecules, which they should recognize later. Biomolecules act as a kind of stamp, leaving nanoscopic "prints" on the spheres. Therefore, subsequently they are ideally suited to the molecules on which they were "imprinted", and specifically bind to them. Unlike antibodies, nanospheres are simple and inexpensive to produce and chemically stable.
For the process of "imprinting" (imprinting), the researchers used a special method, which is the most manageable. It allows imprinting using carbohydrate chains of building blocks (glycans) as templates. Many proteins contain specific "sugar chains" that are unique, like a protein fingerprint. The researchers used a type of glycan from the extracellular end of the HER2 protein as a "stamp". This allowed them to produce nanoparticles that specifically recognize HER2 and selectively bind to it, suppressing dimerization.
Thus, the authors were able to significantly reduce the proliferation of tumor cells in vitro and tumor growth in mice. Healthy cells with such therapy practically did not suffer.
Article by Y. Dong et al. Inhibition of HER2‐Positive Breast Cancer Growth by Blocking the HER2 Signaling Pathway with HER2‐Glycan‐Imprinted Nanoparticles is published in Angewandte Chemie International Edition.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on Wiley: Imprinted Spheres Fight Breast Cancer: Inhibition of HER2 on tumor cells by molecularly imprinted nanoparticles.