A new research paper was published in Volume 17 of Oncotarget, titled “Limitation of the therapeutic potential of DUSP4 through adaptive feedback partially mediated by DUSP5.”

The study explores whether targeting a protein called DUSP4 could help control cancer growth.

Researchers found that reducing DUSP4 activity slowed tumour growth in experimental models, but an adaptive response involving a related protein, DUSP5, appeared to limit its therapeutic potential.

The study was co-first-authored by Barbara Hopfgartner and Monika Kriz, who contributed equally to the research, alongside Donat Alpar, Yvonne Westermaier, Marco H. Hofmann, Ralph A. Neumüller and Sarah Grosche.

All authors are affiliated with Boehringer Ingelheim RCV GmbH & Co KG in Vienna, Austria.

Neumüller and Grosche are the corresponding authors.

Cancer cells depend on molecular signals to grow and divide.

One important signalling network, known as the MAPK pathway, is frequently altered in cancer.

While many existing treatments aim to block excessive MAPK activity, researchers are also investigating whether increasing this activity beyond tolerable levels could interfere with cancer cell growth.

DUSP4 helps regulate the MAPK pathway by limiting the activity of ERK proteins.

In cancers carrying the BRAF V600E mutation, DUSP4 may help prevent excessive signalling, making it a potential therapeutic target.

To explore this possibility, the researchers used genetic approaches to reduce DUSP4 activity in colorectal cancer and melanoma cell models, including cells resistant to the BRAF inhibitor dabrafenib.

They found that DUSP4 reduction increased MAPK signalling and slowed cancer cell proliferation.

In colorectal cancer cells, it also caused cell cycle arrest, preventing cells from progressing normally toward division.

The team then examined the effects of DUSP4 reduction in mice bearing colorectal tumours.

Although tumour growth was significantly inhibited, the tumours remained largely stable rather than shrinking.

Signs of regrowth also appeared during the experiment, suggesting that cancer cells could adapt to the disruption.

Further investigation revealed that reducing DUSP4 increased the expression of DUSP5, a related protein that also regulates MAPK signalling.

In additional cell experiments, higher DUSP5 levels helped compensate for DUSP4 loss and restored cancer cell proliferation to varying degrees.

These findings suggest that cancer cells may adjust their signalling networks to counteract the effects of DUSP4 reduction.

This compensatory response could help explain why targeting DUSP4 alone may not produce lasting tumour regression.

“This points to context-specific genetic buffering among DUSP proteins.”

The results highlight an important challenge in developing treatments that disrupt cancer cell signalling.

Even when a potential target is successfully suppressed, cancer cells may activate alternative mechanisms that reduce the treatment's effectiveness.

However, the findings are based on preclinical experiments involving cancer cell lines and mouse models.

They do not establish how DUSP4-targeted therapies would perform in patients, and further research is needed to determine their clinical potential.

Overall, the study provides insight into how DUSP5-related feedback may limit the therapeutic potential of DUSP4.

Understanding these adaptive responses could help guide future research into more effective strategies for controlling cancer growth.

Source: Impact Journals LLC