A protein that destroys hard to treat cancers has been discovered by scientists - offering hope of effective new treatments. Experiments on mice and human tissue found it is effective against the most aggressive tumours.
They include those of the breast, pancreas, ovaries and brain. The compound, known as ERX-41, leaves healthy tissue unscathed.
It is one of the most promising breakthroughs to date - offering hope of a 'one size fits all' pill that was once thought impossible. Results were so encouraging clinical trials are expected to begin in the next few months.
Lead author Professor Ratna Vadlamudi, of the University of Texas in the United States, said: "We identified a critical vulnerability in multiple cancers and have validated our findings in multiple cancer cell types and animal models. The range of cell lines and xenografts in which the compound has been shown to work is compelling and indicates that it is targeting a fundamental vulnerability in cancer cells."
Xenografts are human tumours grown in mouse models for research purposes. The findings could lead to exciting drugs for cancers that have few effective treatments.
Prof Vadlamudi's lab staff study breast and ovarian cancer with the goal of developing small-molecule inhibitors for tumours that are resistant to current therapies. In 2017 they identified a compound called ERX-11 that targets the oestrogen receptor (ER) protein that drives most breast cancers.
By screening similar chemicals the researchers showed ERX-41 killed ER-positive and triple-negative breast cancers (TNBCs) in petri dishes. They lack receptors for the hormones oestrogen, progesterone and human epidermal growth factor 2 - and are the most deadly.
The researchers then showed ERX-41 also attacked a large number of human tumours grown from several of these cell lines in mouse models. It was also potent against patient-derived xenografts - shrinking human tumours grown in lab rodents without affecting normal breast cells or causing any discernible toxicity.
Prof Vadlamudi said: "The safety profile and high therapeutic index of this compound is particularly notable and bodes well for clinical translation." Further tests found ERX-41 is also effective against pancreatic, brain and ovarian tumours.
They are among the most lethal - with few effective treatments. Prof Vadlamudi added: "This vulnerability has a large therapeutic window, with no adverse effects either on normal cells or in mice. Our study implicates a targeted strategy for solid tumours including breast, brain, pancreatic and ovarian whereby small, orally bioavailable molecules result in tumour cell death."
Dallas-based biotech company EtiraRx hopes clinical trials will be underway in early 2023. The study was published in the journal Nature Cancer.
