Aug 6 2019
Scientists at Tel Aviv University have created a new nano-vaccine for melanoma, which is the most aggressive skin cancer type.
(Image credit: Tel Aviv University)
Their ground-breaking method has until now proven to be effective in inhibiting the development of melanoma in mouse models and in treating primary tumors and metastases that arise from melanoma.
The study is focused on a nanoparticle that acts as the foundation for the new vaccine. The research was headed by Prof. Ronit Satchi-Fainaro, chair of the Department of Physiology and Pharmacology and Head of the Laboratory for Cancer Research and Nanomedicine at TAU’s Sackler Faculty of Medicine, and Prof. Helena Florindo of the University of Lisbon while on sabbatical at the Satchi-Fainaro lab at TAU; it was carried out by Dr Anna Scomparin of Prof. Satchi-Fainaro’s TAU lab and postdoctoral fellow Dr João Conniot.
The outcomes were reported in Nature Nanotechnology on August 5th, 2019.
Melanoma forms in the skin cells that synthesize melanin or skin pigment.
The war against cancer in general, and melanoma in particular has advanced over the years through a variety of treatment modalities, such as chemotherapy, radiation therapy and immunotherapy; but the vaccine approach, which has proven so effective against various viral diseases, has not materialized yet against cancer.
Prof. Ronit Satchi-Fainaro, Chair, Department of Physiology and Pharmacology, TAU
Satchi-Fainaro continued, “In our study, we have shown for the first time that it is possible to produce an effective nano-vaccine against melanoma and to sensitize the immune system to immunotherapies.”
The scientists utilized tiny particles, with a size of around 170 nm, composed of a biodegradable polymer. Inside every particle, they “packed” two peptides—short chains of amino acids that are expressed in melanoma cells. They subsequently administered the nanoparticles (or “nano-vaccines”) into a mouse model carrying melanoma.
“The nanoparticles acted just like known vaccines for viral-borne diseases,” Prof. Satchi-Fainaro described. “They stimulated the immune system of the mice, and the immune cells learned to identify and attack cells containing the two peptides—that is, the melanoma cells. This meant that, from now on, the immune system of the immunized mice will attack melanoma cells if and when they appear in the body.”
Following this, the scientists analyzed the effectiveness of the vaccine under three distinct conditions.
First, the vaccine was confirmed to have prophylactic effects. The vaccine was administered into healthy mice, and subsequently an injection of melanoma cells was administered. “The result was that the mice did not get sick, meaning that the vaccine prevented the disease,” stated Prof. Satchi-Fainaro.
Second, the nanoparticle was employed for the treatment of a primary tumor: An blend of the ground-breaking vaccine and immunotherapy treatments was tested on melanoma mouse model. The synergistic treatment considerably slowed down the disease progression and significantly prolonged the lives of all treated mice.
Finally, the scientists tested their method on tissues derived from patients with melanoma brain metastases. This implied that it is possible to use the nano-vaccine to treat brain metastases too.
Mouse models having late-stage melanoma brain metastases had already been determined after removal of the primary melanoma lesion, imitating the clinical setting. Prof. Satchi-Fainaro’s lab reported the study on image-guided surgery of primary melanoma using smart probes in 2018.
Our research opens the door to a completely new approach—the vaccine approach—for effective treatment of melanoma, even in the most advanced stages of the disease. We believe that our platform may also be suitable for other types of cancer and that our work is a solid foundation for the development of other cancer nano-vaccines.
Prof. Ronit Satchi-Fainaro, Chair, Department of Physiology and Pharmacology, TAU
This work was supported by EuroNanoMed-II, the Israeli Ministry of Health, the Portuguese Foundation for Science and Technology (FCT), the Israel Science Foundation (ISF), the European Research Council (ERC) Consolidator and Advanced Awards, the Saban Family Foundation–Melanoma Research Alliance (MRA) Team Science Award, and the Israel Cancer Research Fund (ICRF).