Breast Cancer Breakthrough

Researchers from the University of Illinois at Urbana-Champaign have identified a single small molecule derivative that could help treat breast cancer.

In 2021, Paul Hergenrother and his team developed ErSO, a small molecule compound “that activates the anticipatory unfolded protein response (a-UPR) and induces rapid and selective necrosis of ERα-positive breast cancer cell lines in vitro (1).” Whilst this molecule was successful in killing breast cancer cells, hwoever, it came with undesirable side effects. The team has now team synthesized derivatives of ErSO – one of which, ErSO-TFPy, was evaluated and found to possess qualities such as the ability to kill multiple human estrogen receptor positive (ER+) breast cancer cell lines in culture; tolerability with no serious side effects in mice, rats, and dogs; and the ability to shrink transplanted human breast tumors in mice.

So promising is this discovery that the researchers believe a single dose could help reduce the risk of side effects and late effects, although further extensive testing is required to confirm safety and efficacy. The study synopsis puts it plainly: “A single dose of ErSO-TFPy leads to complete tumor regressions in multiple mouse xenograft models of breast cancer.” 

Hergenrother said: “It is very rare for a compound to shrink tumors in mouse models of breast cancer, let alone completely eradicate those tumors with a single dose, so we are eager for ErSO-TFPy to advance for treatment of breast cancer.” 

The work is funded by the National Cancer Institute at the National Institutes of Health and the Cancer Center at Illinois. 

Breast cancer is one of the most studied diseases in the world, and appeared at the top of Phesi’s recently published “Top Five Studied Disease Areas in 2024” report. In a 2023 interview with Phesi CEO Gen Li, we learned that around 44,000 women die of breast cancer each year. It is therefore no surprise that it remains a consistent area of high priority. There were just under 1,800 global recruiting breast cancer trials in 2024 (up from just over 1,200 in 2023).