USC progenitor cells that self-renew in the lab slowed blood and solid tumors in mice
Engineered granulocyte-monocyte progenitors from a USC team slowed blood cancers and solid tumors in mice, according to a study in Cell. A self-renewing source of such cells could ease manufacturing, but every result described so far comes from mice.
The Scientist · Science desk
What happened
- The team genetically modified the cells to recognize specific cancer markers and to strengthen broader immune responses.
- In mice, the engineered cells established themselves in bone marrow and produced new immune cells.
- Long-term self-renewal in blood has traditionally been tied to hematopoietic stem cells, with committed progenitors thought to have less of it.
Why it matters
- What it limits constraint Every result described is from mice, so durability, safety and dosing in patients remain open questions.
- What's now possible capability A cell type that expands in culture and can be gene-edited lets developers engineer one dividing stock and scale from it.
- What doesn't add up contradiction The ScienceDaily headline promises a never-ending supply, but the article text says only potentially renewable, and the text is the claim to hold the work to.
In the blood system, long-term self-renewal has been tied mainly to hematopoietic stem cells. Progenitors are further along and committed to a narrower set of cells, and they are generally thought to have less capacity for it [7]. The USC team worked with granulocyte-monocyte progenitors (GMPs), which normally give rise to macrophages and other immune cells [4]. Under carefully controlled laboratory conditions, the progenitors kept multiplying and kept their identity [8].
Corresponding author Qi-Long Ying, a professor at the Keck School of Medicine of USC [12], said: "We found that, under the right conditions, GMPs can also self-renew, dividing extensively while keeping their identity and ability to produce functional immune cells." [9]
A cell that divides without maturing can be expanded, and the team reports it could also be edited to recognize cancer markers [5][6]. The release lists the difficulty of making enough immune cells, and of keeping them active in the body, among the biggest obstacles in cancer immunotherapy [16]. Ying said: "That gives us a scalable starting point for engineering cell therapies for cancer, infectious disease and potentially many other conditions." [15]
The mouse work is where the "continuous" claim gets tested. The engineered cells settled in bone marrow and produced new immune cells [2]. Disease progressed more slowly in both blood cancers and solid tumors [3]. A population that lodges in marrow and keeps making cells is the feature that would make a therapy last, so we would want that result replicated first.
The ScienceDaily text, which reprints material from the Keck School of Medicine of USC [14], describes the tumor results only as slowed progression, without saying how large the effect was. The portion reviewed here does not report group sizes, control arms, survival or how long the engineered cells persisted.
The headline and the text also differ. ScienceDaily's headline promises a "never-ending supply", while the body calls it a "potentially renewable" one [10]. The body's wording is the one the evidence supports, and a cell line that expands for a long time in a dish is a different thing from one that has been shown to last in a patient.
What to watch
- The Cell paper's methods: group sizes, control arms, survival data and how long the engineered cells persisted in mouse bone marrow.
- Whether other labs reproduce GMP self-renewal in culture under the same conditions.
- Whether the team reports any work with human GMPs, the step that would test the ready-made therapy idea.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence35
- Adoption
- Not scored
- Hype gap+40
- Incentives
- Not scored
- Confidence40
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Scientists at the University of Southern California described the GMP system in a study published in Cell.
- [2]
In experiments involving mice, the engineered cells established themselves in bone marrow and produced new immune cells.
- [3]
In the mouse experiments, the engineered cells slowed the progression of both blood cancers and solid tumors.
- [4]
Granulocyte-monocyte progenitors (GMPs) normally develop into macrophages and other immune cells that protect the body from infections and participate in immune responses.
- [5]
The researchers found that GMPs could be grown extensively in the laboratory while retaining their ability to develop into functioning immune cells.
- [6]
The GMPs could be genetically modified to recognize specific cancer markers and strengthen broader immune responses.
- [7]
Long-term self-renewal in the blood system has traditionally been associated primarily with hematopoietic stem cells; progenitor cells are committed to a more limited range of cells and are generally thought to have less capacity for long-term self-renewal.
- [8]
Under carefully controlled laboratory conditions, GMPs continued multiplying while preserving their identity and their capacity to generate functional immune cells.
- [9]
Qi-Long Ying said: "We found that, under the right conditions, GMPs can also self-renew, dividing extensively while keeping their identity and ability to produce functional immune cells."
- [10]
The ScienceDaily headline refers to a 'never-ending supply' of cancer-fighting cells, while the article text describes a 'potentially renewable' supply.
- [11]
The release says the discovery challenges a long-standing understanding of how blood and immune cells develop.
- [12]
Qi-Long Ying, MD, PhD, is the paper's corresponding author and a professor of stem cell biology and regenerative medicine at the Keck School of Medicine of USC.
- [13]
The release summary says the researchers developed a system that can continuously produce tumor-fighting cells inside the body.
- [14]
ScienceDaily lists the Keck School of Medicine of USC as the source of the article.
- [15]
Qi-Long Ying said: "That gives us a scalable starting point for engineering cell therapies for cancer, infectious disease and potentially many other conditions."
- [16]
The release says the work could help overcome some of the biggest obstacles facing cancer immunotherapy, including the difficulty of manufacturing enough immune cells and keeping them active in the body.
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Sources
1 independent publisher whose own reporting we read for this story.
- sciencedaily.comUSC scientists discover how to create a never-ending supply of cancer-fighting cells
1 article · October 16, 2026
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