Navigation Links
Potential Brain Cancer Drug for Children May Damage Bones
Date:3/10/2008

- Animal Study Raises Caution on Using Signal Transduction Inhibitors in Children -

PHILADELPHIA, March 10 /PRNewswire-USNewswire/ -- A novel drug that fully eliminated brain tumors from mice in a dramatic 2004 study has shown a darker side -- causing permanent bone damage in younger mice. The researcher who conducted both studies says the disappointing new finding raises concerns about using similar drugs to treat children's cancers, at least until there is a more thorough understanding of possible risks.

Tom Curran, Ph.D., a developmental biologist at The Children's Hospital of Philadelphia, led the study, published in the March 2008 issue of the journal Cancer Cell. The drug in question, HhAntag, is a signal transduction inhibitor--an agent that blocks signals along a biological pathway. In mice specially bred for these studies by Curran's research group, HhAntag specifically acts against signals on a pathway leading to medulloblastoma, a type of brain tumor found mostly in children.

Much current cancer research has focused on signal transduction inhibitors (STIs) because of their potential to interrupt specific biological pathways that give rise to cancer. To date, only one STI has been approved by the Food and Drug Administration for use in children. That drug, which acts on different biological pathways than HhAntag does, has not been associated with any developmental defects in children. However, other STIs are currently in pediatric clinical trials.

His team's new findings, says Curran, raise a strong caution. "While it is not clear that the bone defects we observed in mice would also occur in children, and while signal transduction inhibitors may still represent a highly promising approach to treating pediatric cancer, it may be important to perform preclinical testing in young animals before moving ahead to clinical trials," he added. Young animals could provide a model of a drug's potential effects during childhood development.

The drug used by Curran's group acts on the hedgehog (Hh) pathway, which is known to play multiple roles during the development of mammals. Mutations of genes along that pathway lead to different cancers, including medulloblastoma, the most common cancerous brain tumor in children. Because conventional treatment with surgery, radiation and chemotherapy causes serious long-term side effects such as ataxia (a movement disorder) and cognitive impairments, the researchers sought novel, less toxic treatments for medulloblastoma.

In 2001, using genetic engineering, Curran bred mice to develop medulloblastoma. He then treated those mice with HhAntag, which had previously been developed by a biotech company for treating skin cancer in adults. In 2004, while at St. Jude's Children's Research Hospital, Curran reported highly promising results from the mouse studies. At high doses, the drug caused the tumors to shrink and in some cases, disappear entirely. The treated mice also survived much longer than untreated mice, with no serious side effects.

The drug seemed to be an unusually strong candidate for trials in children with the type of medulloblastoma having gene mutations on the Hh pathway--about a third of cases.

However, when Curran's group tested the agent on young mice (10 to 14 days old, in contrast to the adult mice tested previously), they found an unpleasant surprise: serious impairments to developing bones. The mice were smaller, with lower weight and shorter bones than untreated mice, and the effects were not reversible. Even four doses of the drug permanently stunted their growth. "We already knew that the same biological pathway involved in the growth of tumors was also involved in bone development," said Curran, "but we did not expect temporary inhibition to cause an irreversible change in bone growth."

While the current studies were disappointing, said Curran, they do not totally rule out a future role for HhAntag as a treatment for medulloblastoma. "The effects we see in mice may be less dramatic in children, and there may be methods of delivering this drug directly to brain tissue, while avoiding bones. Alternatively, we might discover other drugs that act on the hedgehog pathway but selectively target brain tissue." Another approach, he adds, may be to use HhAntag only in older children who have already completed their growth, or in the admittedly small proportion of medulloblastoma patients who are adults.

"Signal transduction inhibitors such as this drug may still prove beneficial in treating children's cancers, but our findings raise questions about possible adverse effects during childhood development," said Curran.

The National Institutes of Health supported the study. The biotech company Genentech provided supplies of the drug used in the research. Curran's co-authors were Hiromichi Kimura, formerly of St. Jude's Children's Research Hospital; and Jessica M.Y. Ng, of The Children's Hospital of Philadelphia.

About The Children's Hospital of Philadelphia: The Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking third in National Institutes of Health funding. In addition, its unique family-centered care and public service programs have brought the 430-bed hospital recognition as a leading advocate for children and adolescents. For more information, visit http://www.chop.edu.

Contact: John Ascenzi

Phone: (267) 426-6055


'/>"/>
SOURCE The Children's Hospital of Philadelphia
Copyright©2008 PR Newswire.
All rights reserved

Related medicine news :

1. DNA vaccine against multiple sclerosis appears safe, potentially beneficial
2. UCLA study identifies designer estrogen as potential MS drug
3. Office-Based Medical Treatment and Internet Resources Are Potential Solution to Rising Painkiller Misuse Among Teens, Young Adults
4. Common abdominal pain may be due to a potentially treatable newly recognized inflammatory reaction
5. Potential new approach to treat cognitive impairments in schizophrenia
6. Nosespray vaccine using aloe vera has exciting potential, researcher says
7. Network approach identifies potential breast cancer susceptibility gene
8. Liver fibrosis will be treated by a potential target
9. Researchers study potential health benefits of natural chemicals in muscadine grape seeds
10. Jefferson researchers find stem cells in degenerating spinal discs, potential for repair
11. China Holdings, Inc. Announces 2nd Biomass Renewable Energy Project (Power Capacity: 50 MW); Total Potential: 100 MW in Biomass Energy Pipeline
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2017)... ... 24, 2017 , ... The weather is heating up and the days are ... should be aware that the summer months provide more than warmer temperatures that are ... can be negatively affected from direct exposure to the sun. When it comes to ...
(Date:6/23/2017)... , ... June 23, 2017 , ... By scoring 100% ... ninth consecutive four-star rating from premier online charity evaluator, Charity Navigator, validating ANRF's work ... 1% of all charities reviewed by Charity Navigator and earns ANRF a spot on ...
(Date:6/23/2017)... (PRWEB) , ... June 23, 2017 , ... ... plastic surgeon practicing in Newburgh, New York, has recently begun offering three new ... to offering the best cutting-edge procedures and reducing downtime, Dr. Rubinstein is excited ...
(Date:6/23/2017)... Hills, CA (PRWEB) , ... June 23, 2017 , ... ... plane facelift . Dr. Talei has come up with a proprietary technique that ... releases and lifts tissues that have dropped. For all ages, patients can expect to ...
(Date:6/23/2017)... (PRWEB) , ... June 23, 2017 , ... MD ... Florida. This is MD Now’s 28th facility overall and marks the urgent care center's ... located one mile North of The Falls shopping mall. The new clinic offers a ...
Breaking Medicine News(10 mins):
(Date:6/20/2017)...  Hill-Rom Holdings, Inc. (NYSE: HRC), will host its fiscal ... July 28, 2017, beginning at 7:30 a.m. (CDT) / 8:30 ... To participate in the conference call, dial (877) 304-8969 (domestic) ... least 10 minutes prior to the start to allow time ... Webcast: A simultaneous webcast of the ...
(Date:6/16/2017)... , June 16, 2017  Exactly 50 years ago ... off what later became known as the San Francisco "Summer ... ) is unveiling two radical innovations in strategic market research ... This announcement marks the beginning of Northern Light,s "Summer of ... ...
(Date:6/14/2017)... -- In 2016, Embodied Labs took top prize ... came away with $25,000 in seed-fund investment. Embodied Labs ... "entering the life of another" and by the Journal ... medical professionals in an entirely new dimension." Building upon ... for the Department of Education,s EdSimChallenge, where they received ...
Breaking Medicine Technology: