News | New Study Reveals How Ovarian Cancer Spreads Rapidly: Cancer Cells Recruit Protective Abdominal Cells to Invade Together
Ovarian cancer is one of the deadliest gynecologic malignancies, largely because it is often diagnosed at an advanced stage, after cancer cells have spread widely throughout the abdominal cavity. Scientists have long known that ovarian cancer spreads unusually quickly, but the underlying biological mechanism has not been fully explained.
A recent study from Nagoya University in Japan has shed light on this key question. Researchers found that ovarian cancer cells do not act alone. They “recruit” mesothelial cells from the abdominal cavity as partners, forming mixed cell clusters that invade surrounding tissues more efficiently and show greater resistance to chemotherapy.
The findings were published in Science Advances.
Cancer Cells and Protective Abdominal Cells Form “Mixed Spheroids”
To understand how ovarian cancer spreads rapidly within the abdominal cavity, the team analyzed the cellular composition of ascites samples from patients with ovarian cancer.
Contrary to the previous assumption that cancer cells float alone in the abdominal cavity, most were attached to mesothelial cells and formed tightly packed mixed-cell spheroids.
The study estimated that about 60% of cancer cell spheroids contained “recruited” mesothelial cells.
Further research showed that ovarian cancer cells release a signaling molecule called TGF-β1. It changes the state of mesothelial cells, causing them to form spike-like structures. These structures can cut through surrounding tissue, creating channels through which cancer cells enter new tissue.
A Pattern of Spread Unlike Most Cancers
As ovarian cancer progresses, some cancer cells detach from the primary tumor and enter the fluid environment of the abdominal cavity. This fluid moves continuously with breathing and body movement, carrying cancer cells to different areas of the abdomen.
This mode of spread differs substantially from many other cancers. Breast and lung cancers, for example, commonly enter the bloodstream through blood vessels and metastasize to distant organs. Because circulation follows relatively fixed routes, clinicians can sometimes use blood tests to monitor the spread of these cancers.
Ovarian cancer, however, largely bypasses the vascular system and spreads by floating directly in abdominal fluid. Because this fluid has no fixed direction of flow, cancer cell movement is difficult to predict, making disease monitoring more challenging.
Scientists previously did not understand what happened to cancer cells during this “floating phase” or how they metastasized so efficiently.
Mesothelial Cells Act as the “Vanguard of Invasion”
The team found that during the floating phase, ovarian cancer cells actively recruit mesothelial cells shed from the peritoneum and bind with them to form mixed spheroids.
Within these mixed structures, mesothelial cells form spike-like structures called invadopodia. These can penetrate nearby tissue like drill bits.
Once the mixed-cell spheroids attach to the surface of a new organ, the mesothelial cells create invasion pathways first, and the cancer cells then move into the tissue along these routes.
The researchers noted that compared with cancer cells alone, the mixed-cell spheroids not only invaded more quickly but were also more resistant to chemotherapy drugs.
Real-Time Observation of Cancer Spread
Using advanced microscopic imaging, the team observed the behavior of cells from patient ascites in real time. They validated the mechanism through mouse-model experiments and single-cell gene expression analysis.
First author Kaname Uno, MD, PhD, a visiting researcher at Nagoya University School of Medicine, said the cancer cells themselves do not need to undergo major genetic or molecular changes during this process.
He explained: “The cancer cells are effectively manipulating mesothelial cells to invade tissue. They only need to move through the channels created by the mesothelial cells.”
Dr. Uno worked as a gynecologist for eight years before entering research. He recalled that one patient’s experience profoundly influenced his research direction. The patient had normal test results three months earlier but was then diagnosed with advanced ovarian cancer and could not be saved because the disease progressed so rapidly.
The experience prompted him to investigate why ovarian cancer spreads so quickly and why current screening methods struggle to detect it early.
New Directions for Future Treatment and Monitoring
The researchers believe the finding identifies potential new targets for ovarian cancer treatment.
Most current chemotherapy drugs primarily target the cancer cells themselves rather than the mesothelial cells that play a key role in metastasis.
Future treatment strategies may include:
Blocking the TGF-β1 signaling pathway
Preventing cancer cells and mesothelial cells from forming mixed-cell clusters
The study also suggests a new approach to disease monitoring. By detecting mixed-cell spheroids in abdominal fluid, clinicians may be able to predict ovarian cancer progression and treatment response more accurately.
The researchers said the discovery provides important clues to why ovarian cancer spreads rapidly and opens new research directions for more effective diagnostic and treatment strategies.
News | New Study Reveals How Ovarian Cancer Spreads Rapidly: Cancer Cells Recruit Protective Abdominal Cells to Invade Together
News | New Study Reveals How Ovarian Cancer Spreads Rapidly: Cancer Cells Recruit Protective Abdominal Cells to Invade Together
Ovarian cancer is one of the deadliest gynecologic malignancies, largely because it is often diagnosed at an advanced stage, after cancer cells have spread widely throughout the abdominal cavity. Scientists have long known that ovarian cancer spreads unusually quickly, but the underlying biological mechanism has not been fully explained.
A recent study from Nagoya University in Japan has shed light on this key question. Researchers found that ovarian cancer cells do not act alone. They “recruit” mesothelial cells from the abdominal cavity as partners, forming mixed cell clusters that invade surrounding tissues more efficiently and show greater resistance to chemotherapy.
The findings were published in Science Advances.
Cancer Cells and Protective Abdominal Cells Form “Mixed Spheroids”
To understand how ovarian cancer spreads rapidly within the abdominal cavity, the team analyzed the cellular composition of ascites samples from patients with ovarian cancer.
Contrary to the previous assumption that cancer cells float alone in the abdominal cavity, most were attached to mesothelial cells and formed tightly packed mixed-cell spheroids.
The study estimated that about 60% of cancer cell spheroids contained “recruited” mesothelial cells.
Further research showed that ovarian cancer cells release a signaling molecule called TGF-β1. It changes the state of mesothelial cells, causing them to form spike-like structures. These structures can cut through surrounding tissue, creating channels through which cancer cells enter new tissue.
A Pattern of Spread Unlike Most Cancers
As ovarian cancer progresses, some cancer cells detach from the primary tumor and enter the fluid environment of the abdominal cavity. This fluid moves continuously with breathing and body movement, carrying cancer cells to different areas of the abdomen.
This mode of spread differs substantially from many other cancers. Breast and lung cancers, for example, commonly enter the bloodstream through blood vessels and metastasize to distant organs. Because circulation follows relatively fixed routes, clinicians can sometimes use blood tests to monitor the spread of these cancers.
Ovarian cancer, however, largely bypasses the vascular system and spreads by floating directly in abdominal fluid. Because this fluid has no fixed direction of flow, cancer cell movement is difficult to predict, making disease monitoring more challenging.
Scientists previously did not understand what happened to cancer cells during this “floating phase” or how they metastasized so efficiently.
Mesothelial Cells Act as the “Vanguard of Invasion”
The team found that during the floating phase, ovarian cancer cells actively recruit mesothelial cells shed from the peritoneum and bind with them to form mixed spheroids.
Within these mixed structures, mesothelial cells form spike-like structures called invadopodia. These can penetrate nearby tissue like drill bits.
Once the mixed-cell spheroids attach to the surface of a new organ, the mesothelial cells create invasion pathways first, and the cancer cells then move into the tissue along these routes.
The researchers noted that compared with cancer cells alone, the mixed-cell spheroids not only invaded more quickly but were also more resistant to chemotherapy drugs.
Real-Time Observation of Cancer Spread
Using advanced microscopic imaging, the team observed the behavior of cells from patient ascites in real time. They validated the mechanism through mouse-model experiments and single-cell gene expression analysis.
First author Kaname Uno, MD, PhD, a visiting researcher at Nagoya University School of Medicine, said the cancer cells themselves do not need to undergo major genetic or molecular changes during this process.
He explained: “The cancer cells are effectively manipulating mesothelial cells to invade tissue. They only need to move through the channels created by the mesothelial cells.”
Dr. Uno worked as a gynecologist for eight years before entering research. He recalled that one patient’s experience profoundly influenced his research direction. The patient had normal test results three months earlier but was then diagnosed with advanced ovarian cancer and could not be saved because the disease progressed so rapidly.
The experience prompted him to investigate why ovarian cancer spreads so quickly and why current screening methods struggle to detect it early.
New Directions for Future Treatment and Monitoring
The researchers believe the finding identifies potential new targets for ovarian cancer treatment.
Most current chemotherapy drugs primarily target the cancer cells themselves rather than the mesothelial cells that play a key role in metastasis.
Future treatment strategies may include:
Blocking the TGF-β1 signaling pathway
Preventing cancer cells and mesothelial cells from forming mixed-cell clusters
The study also suggests a new approach to disease monitoring. By detecting mixed-cell spheroids in abdominal fluid, clinicians may be able to predict ovarian cancer progression and treatment response more accurately.
The researchers said the discovery provides important clues to why ovarian cancer spreads rapidly and opens new research directions for more effective diagnostic and treatment strategies.
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Collected online