Breast cancer is the most diagnosed cancer in Canadian women, with an overall survival rate of 87%. A new advancement in immunotherapy has demonstrated a high response of complete remission in patients with relapsed acute lymphoblastic leukaemia and has the potential to treat solid tumours in diseases like breast cancer. The chimeric antigen receptor T-cell treatment expresses the CAR protein on the surface of each T-cell to allow them to efficiently target and destroy the associated protein found on the surface of tumour cells. As groundbreaking as the in vitro production of CAR-T cells is, it is still extremely laborious and expensive.
The purpose of this project is to develop a novel therapy that engineers the tyrosine kinase orphan receptor (present on triple-negative breast cancer cells) specific CAR T-cells in vivo to eradicate breast cancer. This would allow for a more widespread and affordable administration of the treatment since nanoparticles can be easily manufactured for a low price. In this project, 2 different types of nanoparticles (CMCS/TPP and PEOGMA/DMAEMA) and a control sample were inserted into breast cancer cell lines. The results showed that the CMCS/TPP sample showed the most cell intake of the nanoparticles, therefore asserting it as the best sample to use as a gene carrier for the CAR protein. The next steps in this research project are to program the T-lymphocytes, in vitro, with the nanoparticles loaded with the plasmids carrying the ROR1-specific CAR, then analysing the data to predict the outcomes of the in vivo implementation.
What inspired you (or your team)?
I have always been interested in the intersection of oncology and nanotechnology, and I truly believe that the combination of medicine and technology will facilitate the development of novel therapies to cure cancer in our lifetime! The two research papers that inspired my research project are “In Situ Programming of Leukaemia-Specific T Cells Using Synthetic DNA Nanocarriers” by Smith, Tyrel T., et al. (2017), and “Phase I study of immunotherapy for advanced ROR1+ malignancies with autologous ROR1-specific chimeric antigen receptor-modified (CAR)-T cells” by Specht, J., Lee, S., Turtle, C., et al. (2018).
The publication by Nat Nanotechnol discusses a new approach of producing CAR T-cells by administering DNA carriers which can rapidly program the CAR genes into host T-cells. The results of their revolutionary research established the possibility of programming T-cells with CARs in vitro via engineered nanoparticles. By injecting mice with the 194-1BBz CAR carrying particles, they found that tumours were eradicated in 7/10 of the mice and the rest of the mice had a regression with a 58-day average improvement in survival! (Smith, Tyrel T., et al., 2017). This research paper gave me my first glimpse at the possibilities of using nanoparticles to program CAR T-cells within the body. The results, methods, and background information allows me to create a research project that will build on and improve their research methods based on the recommendations provided, with a focus on breast cancer and using in vitro cell lines to predict in vitro outcomes.
The first-in-human trial using receptor tyrosine kinase orphan receptor (ROR1) specific CARs was conducted on 6 patients in 2018. 4 patients had triple-negative breast cancer (TNBC) and 2 had non-small cell lung cancer (NSCLC). Post-treatment tumour biopsies revealed some positive results; an influx of T-cells in 2 patients experiencing a low level of tumour infiltration, and 4 patients demonstrating decreased disease burden. However, many improvements are still being made to eradicate potential barriers such as T-cell exhaustion (Specht, J., Lee, S., Turtle, C., et al., 2018). This clinical trial helped me better understand the biology of breast cancer cells and exposed me to new challenges that may be faced when using the CAR T-cell therapy to treat breast cancer, in addition to helping me determine what CAR protein to use in my research project.
Smith, Tyrel T., et al. “In Situ Programming of Leukaemia-Specific T Cells Using Synthetic DNA Nanocarriers.” Nature Nanotechnology, vol. 12, no. 8, 17 Apr. 2017, pp. 813–820., doi:10.1038/nnano.2017.57.
Specht, J., Lee, S., Turtle, C., Berger, C., Veatch, J., Gooley, T., Mullane, E., Chaney, C., Riddell, S. and Maloney, D. (2018). Phase I study of immunotherapy for advanced ROR1+ malignancies with autologous ROR1-specific chimeric antigen receptor-modified (CAR)-T cells. Journal of Clinical Oncology, 36(5_suppl), pp.TPS79-TPS79