A potential new treatment for triple negative breast cancer: Blocking TGF-beta may improve the outcomes of chemotherapy

This laboratory based study investigates the use of compounds which block TGF-β signalling in triple negative breast cancer cells.  They show that inhibiting this process prevents the development of paclitaxel resistance and the recurrence of cancers following paclitaxel treatment. 

Triple negative breast cancers are aggressive because they lack hormone receptors as well as large amounts of HER2 receptors. Patients with triple negative breast cancer often respond to an initial round of chemotherapy treatment. However, small populations of cells that survive and cause recurrences and malignancies are often resistant to this treatment.

Transforming growth factor beta (TGF-β) is a protein which controls cell division and the development of various types of cells (a process also known as cell differentiation).  In the laboratory, scientists have shown that cancer cells have receptors for TGF-β on their surface.  When these receptors interact with the TGF-β protein, cell division is activated.

This article discusses the possibility of blocking TGF-β and its interaction with its receptor as a potential new treatment option for patients with triple negative breast cancer. 

This study showed that the chemotherapy drug paclitaxel can increase signals from TGF-β and as a result can increase tumor recurrence. By treating the same cancer cells used in these experiments with a TGF-β receptor blocker called  LY2157299 and a drug against the TGF-β type II receptor, TGF-b signalling was prevented.  Additionally, researchers found that treatment with these two compounds prevented the recurrence of cancers after paclitaxel treatment.

Overall, this study showed that chemotherapy-induced TGF-β signalling promotes tumor recurrence and that drugs that block TGF-β may prevent the development of drug-resistant cancer cells.  These are promising results which have the potential to be developed into a new treatment for a form of breast cancer which is currently very difficult to treat.

Unfortunately, TGF-β blockers are still highly experimental and have to be researched further to determine their safety and efficacy.

These findings support testing a combination of TGF-β inhibitors and anti-cancer chemotherapy in patients with triple negative breast cancers. Clinical trials are awaited.