Spreading cancer survives via signals from nearby blood vessels long before new vessels are grown
December 19, 2003DURHAM, N.C. -- In one of the clearest models of cancer metastasis, scientists have shown that spreading cancer cells receive growth-sustaining signals from nearby blood vessels telling them where to go for permanent nourishment and oxygen.
These signals actually protect the fledgling cancer cells long before new blood vessels have grown around the cancer to supply it with a more permanent source of nutrients and oxygen, said the researchers from the Duke Comprehensive Cancer Center.
Their results will be published in the Dec. 19, 2003, issue of the Federation of American Societies for Experimental Biology Journal.
"We've demonstrated a give and take relationship in which cancer cells release signals to nearby blood vessels to stimulate new vessel growth, and in turn, blood vessels release signals that sustain the migrating cancer cells as they try to establish themselves in new tissue," said Duke cancer biologist Mark Dewhirst, Ph.D.
Dewhirst said his findings present a model of the earliest stages of cancer metastasis, and they bolster medicine's latest strategy of blocking blood vessel growth as a means of inhibiting cancer's spread.
Scientists have long known that tumors secrete proteins which promote the growth of new blood vessels to sustain the tumor's continued growth. What they didn't realize is that endothelial cells that line the blood vessels are also releasing signals back to the cancer cells that protect the cancer cells from dying and direct them to grow toward the blood vessel.
In fact, the cancer cells respond to the endothelial cells' messages by elongating and stretching toward the blood vessel in a column formation, their study showed. This change occurs within days after the cancer cells are implanted in the tissue, and long before new blood vessels have begun to form.
"Our data show that blood vessel endothelial cells are involved in cancer survival and growth at a far earlier stage than we had originally believed," said Dewhirst. "This discovery energizes our efforts to block these signals from being released and to inhibit new blood vessels from forming." Such a strategy is called anti-angiogenesis.
The two-way dialogue begins when cancer cells secrete proteins -- such as vascular endothelial growth factor (VEGF) and angiopoietin 2 -- that alert blood vessels to their presence. These proteins prime the blood vessels to initiate new blood vessel growth.
In response, blood vessel endothelial cells release numerous growth and survival factors that sustain the tumor's survival and invasion of the tissue, the study indicated.
Dewhirst's team demonstrated this two-way dialogue between cancer cells and blood vessels by testing how certain signals affected cancer cells in the test tube and in animals. They found that:
- a signal called bFGF (also known as a cytokine) known to promote cancer cell survival in the body had no effect on cancer cells in a test tube. This finding shows that bFGF is not directly acting on cancer cells, but instead it is signaling another player -- probably endothelial cells in blood vessels -- to induce cancer cell growth.
- the cancer cell models in the current study do not even have bFGF receptors -- docking sites for proteins to bind to and activate a reaction inside the cell. Without a bFGF receptor, the bFGF protein cannot directly communicate the cancer cell.
- when scientists prevented cancer cells from utilizing VEGF -- a protein that prompts blood vessel growth -- they inhibited cancer cell survival and growth long before new blood vessels had begun to grow.
- by blocking a vessel-growth protein receptor called Tie2, the scientists inhibited cancer cell survival long before new blood vessels had begun to grow. This suggests that Tie2 is also involved in promoting cancer survival, not just blood vessel growth.
-end-
Duke University Medical Center
Related Cancer Articles from Brightsurf:
New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.
UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.
Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.
Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.
Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.
Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.
Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.
More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.
New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.
American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.
Read More: Cancer News and Cancer Current Events
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.
UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.
Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.
Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.
Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.
Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.
Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.
More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.
New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.
American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.
Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.