Sep 30, 2021 - Science

Proteins give a clearer picture of cancer growth

A cancer cell

Illustration: Rebecca Zisser/Axios

A new analysis found unique networks of hundreds of proteins that may drive the growth of breast, head and neck cancers, according to three studies out today.

Why it matters: Cancers differ in many aspects, including their mutations. But, there are some common systems of cells involved, including protein networks, that may affect cancer growth and scientists hope to target them with therapies.

  • By better understanding protein-protein interaction (PPI) networks and their role in driving cancers, scientists can greatly expand the number of potential drug targets.
  • "PPIs are critical because they extend far beyond gene lists to define the protein biochemistry of tumor pathways and druggable targets," Stanford University School of Medicine's Ran Cheng and Peter Jackson say in a perspective piece.
  • By creating innovative methods to examine PPI data and cancers, they write, there's a greater chance of reaching "the promise of better personalized medicine identifying the relevant therapy for each patient."

The latest: The journal Science Thursday posted studies with an analysis that mapped 395 protein systems in 13 cancer types, focusing on data from studies on head and neck squamous cell cancers and breast cancers.

  • The three related papers examined how hundreds of mutations in breast and head and neck cancers affect the activity of proteins that drive the diseases.
  • They also discovered some hard-t0-detect mutations in some proteins that may affect tumor growth as well as some biomarkers that could be used in clinical sequencing panels.
  • For head and neck cancer, they found 771 PPIs, 84% of which were never reported before. The breast cancer findings include locating two proteins that affect the function of the tumor-suppressor gene BRCA1 and two proteins that regulate PIK3CA, which have been linked to breast cancer.

What they're saying: Raghu Kalluri, chairman of cancer biology at MD Anderson Cancer Center in Houston, tells Axios these studies offer "good progress" toward efforts to "identify things that were not identified before as vulnerabilities, for which there may be drugs available."

  • "Looking at how proteins interact with others, in a broad sense of a network that formed to control the fate of a cancer cell, will provide us with new insights into other proteins that could be impacted," says Kalluri, who was not part of these studies.
  • However, more validation from other groups and using genetic mouse models are needed, he adds.

What's next: Researchers will continue working on the big question: which mutations in different genes affect the interactions of proteins that drive cancer growth, Marcus Kelly, postdoctoral researcher and a co-author of one of the papers, tells Axios.

  • "We are looking at these protein systems at multiple scales. Some of these protein systems are kind of small clumps of proteins that basically always stick together, and others are these signaling pathways that involve a bunch of different proteins, handing information off to each other," he says.
  • "It's important to test those different scales because the mutations may be affecting processes on different scales as well," Kelly says.
  • See their interactive map of the protein systems here.
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