Brazilian plant protein inhibits progression of triple-negative breast cancer

Researchers from Unifesp have determined that a molecule isolated from the Pacara Earpod Tree is able to inhibit the migration and metastasis of that aggressive tumor as well as gastric and skin tumors.

By Elton Alisson, in Brussels (Belgium)  |   Agência FAPESP – Triple-negative breast cancer that has one of the most aggressive tumors for which there have been few advances in developing therapies in recent years, still lacks a specific treatment and an agent that is able to fight it.

A protein extracted from the seeds of the tree species Enterolobium contortisiliquum – commonly known as the Pacara Earpod Tree –, may offer hope for treatment of this disease in the future.

The results were presented by Maria Luiza Vilela Oliva, Unifesp professor and coordinator of the study in a talk at FAPESP Week Belgium.

“We determined that the protein inhibits the invasion, proliferation and metastasis of triple-negative breast cancer in in vitro tests [in cells] and, in the case of melanoma, in both the in vitro model as well as the in vivo model [in animals],” Oliva told the FAPESP News Agency.

Known as Enterolobium contortisiliquum trypsin inhibitor (EcTI), Oliva isolated the protein while pursuing her doctoral studies in the late 1980s.

Since that time, the researcher has attempted to isolate other molecules that inhibit protease – enzymes capable of breaking down the peptide bonds of other proteins – from leguminous seeds of Brazilian flora.

Oliva explained that those enzymes are involved in various biological processes such as inflammation, hemostasis (the prevention and stoppage of bleeding), thrombosis and tumor development, in addition to other processes that involve pathological microorganisms.

“We have studied the physiopathological effects of these proteins isolated from leguminous plants on some types of cancer in an attempt to discover new agents that could if not cure at least help us understand the pathology of those diseases,” she said.

In addition to isolating the proteins, the researchers have managed to determine the structure of these proteins, model them and obtain synthetic peptides from them.

Analyses of those molecules in various physiopathological models, such as that of inflammation, thrombosis and tumor, both in vivo as well as in vitro have indicated that besides having an anti-tumoral effect, they presented anti-inflammatory, anti-microbial and anti-thrombotic properties.

“Tumors, inflammation and thrombosis are pathologies that are somehow interconnected because sometimes patients with cancer can die, not because of the disease itself, but as a result of a chemotherapy that may lead to the development of a thrombosis,” she added.

The researcher also stated that besides having an anti-tumoral effect, the protein EcTI, which was patented, also demonstrated an ability to inhibit arterial and venous thrombosis.