Researchers on Verge of Breakthrough New Class of Cancer Drugs

Inhibiting a previously undruggable protein holds promise for treatment of numerous types of cancer.

Blocking a specific protein linked with cancer growth may lead to the development of a breakthrough new class of oncology drugs, a recent study found.

The study, published in the current issue of ACS Chemical Biology, evaluated 6 chemical compounds that inhibit the so-called “oncoprotein” HuR, which binds to RNA and promotes tumor growth.

"These are the first reported small-molecule HuR inhibitors that competitively disrupt HuR-RNA binding and release the RNA, thus blocking HuR function as a tumor-promoting protein," corresponding author Liang Xu said in a press release.

The findings are promising for the treatment of several types of cancer, as high levels of HuR have been found in nearly every cancer type the study evaluated, including colon, prostate, breast, brain, ovarian, pancreas, and lung cancers.

"HuR inhibitors may be useful for many types of cancer," Xu said. "Since HuR is involved in many stem cell pathways, we expect HuR inhibitors will be active in inhibiting 'cancer stem cells,' or the seeds of cancer, which have been a current focus in the cancer drug discovery field."

The compounds in the study can be further optimized for a new class of cancer therapy, specifically stem cells. The results provide the first evidence that indicates HuR is, in fact, druggable.

The researchers examined approximately 6000 compounds in a process called High Throughput Screening, which evaluated compounds that block the HuR interface with healthy human RNA.

The researchers pinpointed 6 compounds that could be starting points of novel cancer drugs that target HuR.

"A cancer-causing gene, or oncogene, makes RNA, which then makes an oncoprotein that causes cancer or makes cancer cells hard to kill, or both," Xu said. "This is the problem we're trying to overcome with precision medicine."