Israeli scientists at Tel Aviv University (TAU) say they have developed a novel nano-vaccine for melanoma – one of the most aggressive forms of skin cancer – that proved efficient in mouse models. The research, they say, paves the way for effective, even preventative, treatment of the potentially fatal disease.
The focus of the research, published on Monday in Nature Technology, a monthly peer-reviewed scientific journal, was a nanoparticle that served as the basis for the new vaccine. In the study, mice injected with the vaccine and then injected with melanoma cells did not get sick.
Led 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 SacklerFaculty of Medicine, Prof. Helena Florindo of the University of Lisbon while on sabbatical at the Satchi-Fainaro lab at TAU, the study was conducted by Dr. Anna Scomparin of Prof. Satchi-Fainaro’s TAU lab and postdoctoral fellow Dr. João Conniot.
The researchers say the results showed how effective their innovative approach was proven in preventing the development of melanoma in mice, while also indicating promising results for treating primary tumors and metastases that result from melanoma.
“The war against cancer in general, and melanoma in particular, has advanced over the years through a variety of treatment modalities, such as surgery, chemotherapy, radiation therapy and immunotherapy; but the vaccine approach, which has proven so effective against various viral diseases, has not materialized yet against cancer,” said Prof. Satchi-Fainaro in a university statement.
“In our study, we have shown that it is possible to produce an effective nano-vaccine against melanoma and to sensitize the immune system to immunotherapies,” she added.
According to the university, the scientists harnessed tiny particles of about 170 nanometers in size made of a biodegradable polymer for their study which they then “packed” with two peptides – short chains of amino acids, which are expressed in melanoma cells. These nanoparticles, or nano-vaccines, were then injected into mouse models bearing melanoma.
Prof. Satchi-Fainaro said the nanoparticles “acted just like known vaccines for viral-borne diseases.”
“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,” she explained. “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.”
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The researchers found that the vaccine was not only preventative, it could also be used as a treatment for melanoma and combat metastasis.
The vaccine, the university said in the announcement, proved to have prophylactic effects. The vaccine was injected into healthy mice, and an injection of melanoma cells followed. “The result was that the mice did not get sick, meaning that the vaccine prevented the disease,” said Prof. Satchi-Fainaro.
The nano-vaccine was also used to treat a primary tumor on melanoma model mice, in combination with immunotherapy treatments.
“The synergistic treatment significantly delayed the progression of the disease and greatly extended the lives of all treated mice” in this case, the university said.
And finally, the researchers validated their approach on tissues taken from human patients with melanoma brain metastases, suggesting the nano-vaccine could be used to treat brain metastases as well.
Mouse models with late-stage melanoma brain metastases had already been established following excision of the primary melanoma lesion, mimicking the clinical setting. Research on image-guided surgery of primary melanoma using smart probes was published last year by Prof. Satchi-Fainaro’s lab, the university said.
Prof. Satchi-Fainaro said the 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,” she explained.