Navigation Links
Tumors grow faster without blood-supply promoting molecule

Dense networks of blood vessels thought to spur cancer's growth could actually hinder rather than promote tumor progression, according to a new study at the University of California, San Diego.

The findings partly explain why drugs designed to treat cancer by strangling its blood supply have been disappointing when used alone and why those treatments are more effective when combined with traditional chemotherapy.

Despite their rapid progression, tumors fed by more normal vascular were also more vulnerable to the effects of standard chemotherapy drugs, the team reports in this week's early online edition of the journal Nature.

Nascent tumors take off as new blood vessels invade, an event called angiogenesis that many see as key to the development of malignancy. But those pathological vessels form tangled structures that are far from normal.

"Tumor blood vessels become more chaotic, disorganized and leaky," said Randall S. Johnson, professor of molecular biology at UC San Diego who led the study. "They become dysfunctional in many ways as a blood vessel network."

Cellular secretions within tumors promote the invasion. The first drugs designed to curtail cancer's blood supply targeted one of these, called VEGF for vascular endothelial growth factor. Inflammatory cells, which infiltrate many types of tumors, provide one source of VEGF.

Johnson's team created a strain of mice in which most inflammatory cells were missing the gene for VEGF, then cross-bred them with a strain that reliably develops mammary tumors and is commonly used to study breast cancer.

"The blood vessels look more organized and less leaky in the engineered mice," said Christian Stockmann, a molecular biology postdoctoral fellow and the first author of the paper.

The blood supply to tumors in these mice was also sparse compared to mice with intact VEGF genes.

"A lot of these classic hallmarks of tumor blood vessels disappeared when the inflammatory cells couldn't make VEGF," Johnson said.

But the cancer grew faster.

All of the mice developed tumors, but at 20 weeks of age, those with low levels of VEGF from inflammatory cells had larger growths that were more likely to have progressed to a later stage of cancer.

"The tumors seemed much happier when they didn't have this chaotic vasculature," Johnson said.

The scientists also injected a cancerous cell line into normal and engineered mice and found that the introduced cells invaded normal tissues more readily without VEGF from inflammatory cells and developed more normal blood supplies.

The tumors that formed were also more susceptible to two different chemotherapy drugs in the mice lacking VEGF from inflammatory cells.

By identifying the cellular source of the critical factor for one pathology associated with cancer, the researchers say their findings may open new avenues for treatment.


Contact: Randall Johnson
University of California - San Diego

Related medicine news :

1. Researchers identify mechanism, possible drug treatment for tumors in neurofibromatosis
2. Chemo Alone Effective in Treating Kids Brain Tumors
3. Breast Cancer Vaccine Blasts Some Tumors
4. Nanomedical approach targets multiple cancer genes, shrinks tumors more effectively
5. Drug Re-Sensitizes Breast Tumors to Treatment
6. Drug/radiation combo may help shrink established tumors
7. Leading Neurosurgical Center in Moscow Purchases CyberKnife System to Expand Ability to Treat Brain and Spinal Tumors
8. Erectile dysfunction drugs allowed more chemotherapy to reach brain tumors in laboratory study
9. Researchers hone technique to KO pediatric brain tumors
10. Researchers identify promising cancer drug target in prostate tumors
11. Identification of 5 genes involved in the metastasis of breast tumors to the lung
Post Your Comments:
(Date:11/25/2015)... ... November 25, 2015 , ... Bcureful—a non-profit organization devoted to ... raising public awareness of the disorder while helping to bring expert medical care ... to bolster progress at the Tuberous Sclerosis Complex Center at Ann & Robert ...
(Date:11/24/2015)... , ... November 24, 2015 , ... ... to offer their patients the many benefits of the revolutionary BIOLASE WaterLase iPlus ... cutting and scraping tools traditionally used by a dentist in Gettysburg, PA ...
(Date:11/24/2015)... ... 24, 2015 , ... ThirdLove, the fast-growing bra company that ... offering 40% off select bras and underwear styles, now through Saturday, November 28th. ... technology and the latest fashion, quickly becoming the next generation of luxury bras. ...
(Date:11/24/2015)... ... 24, 2015 , ... Preparing for the LDT Regulation:, CLIA Won’t Satisfy the ... , FDA has long asserted that design and manufacture of Laboratory Developed Tests ... do not meet the device regulations. , Come up short in an inspection and ...
(Date:11/24/2015)... ... November 24, 2015 , ... United Benefit Advisors (UBA), ... & Company as its newest Partner Firm. Based in Jefferson City, Missouri, their ... trusted advisor regardless of whether that client is a business, a family, or ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... , November 25, 2015 ... Investors"), pursuant to which BioLight and the New Investors ... Ltd. subsidiary ("IOPtima") via a private placement. The financing ... its innovative IOPtimate™ system used in the treatment of ... pathway process for the IOPtimate™ system with the U.S. ...
(Date:11/25/2015)... 2015 Developmental, commercial, and regulatory/legal ... profitability of pharmaceutical products, says GBI Research ... regulatory/legal strategies all play a key role in boosting ... . --> Developmental, commercial, ... in boosting the profitability of pharmaceutical products, says ...
(Date:11/25/2015)... Research and Markets ( ) has ... Global Forecast to 2020" report to their offering. ... 37.21% of the total market share in 2014. The ... is projected to growth at the highest CAGR between ... to the fast growing water, industrial gas treatment, pharmaceutical, ...
Breaking Medicine Technology: