Navigation Links
Cell's recycling center implicated in division decisions
Date:7/28/2014

Most cells do not divide unless there is enough oxygen present to support their offspring, but certain cancer cells and other cell types circumvent this rule. Researchers at The Johns Hopkins University have now identified a mechanism that overrides the cells' warning signals, enabling cancers to continue to divide even without a robust blood supply. In the process, the researchers found that lysosomes the cell's protein "recycling centers" help govern cell division decisions. They also uncovered new evidence that certain drugs can halt the growth of tumors that have high levels of the protein HIF-1alpha.

A summary of their findings will be published the week of July 28 in the journal PNAS.

Low levels of oxygen stimulate the production and activation of HIF-1alpha, which protects cells in two ways. Primarily, it turns on several genes for proteins that help the cells adapt to the lack of oxygen. It can also stop the duplication of DNA, which prevents cells from dividing and adding more oxygen-using cells to an already harsh environment.

Knowing that some cells ignore the warnings of HIF-1alpha and divide anyway, Gregg Semenza, M.D., Ph.D., and his team looked for interactions between HIF-1alpha and Cdk1 and Cdk2, proteins known to regulate cell division decisions. They found that HIF-1alpha interacts with both of them, but that Cdk1 increases HIF-1alpha levels, while Cdk2 lowers them.

Semenza's team suspected that Cdk1 and Cdk2 were acting on HIF-1alpha by marking or not marking it for destruction by the cell's miniature "garbage disposals," called proteasomes. But when the researchers blocked proteasome function, they found no changes in HIF-1alpha levels. Instead, Cdk1 and Cdk2 turned out to alter HIF-1alpha levels by marking or not marking it for destruction by the cell's lysosomes. To their knowledge, this is the first time lysosomes have been implicated in a cell's division decisions.

Remarkably, in certain cancer cells, Cdk2 was able to decrease levels of HIF-1alpha while also stimulating its gene activation activity. The net effect was that cells continued dividing while coping with low oxygen levels. In cultured cells, drugs that inhibit Cdk1 prevented HIF-1alpha levels from falling and restored its ability to halt cell division, suggesting they may be effective treatments for certain cancers.


'/>"/>

Contact: Catherine Kolf
ckolf@jhmi.edu
443-440-1929
Johns Hopkins Medicine
Source:Eurekalert

Related medicine news :

1. New drug prevents spread of human prostate cancer cells
2. Tiny hitchhikers attack cancer cells
3. To prevent leukemias dreaded return, go for the stem cells
4. Scientists identify major source of cells defense against oxidative stress
5. Therapy exploits addiction of leukemia cells
6. IBN discovers human neural stem cells with tumor targeting ability
7. Leukaemia cells have a remembrance of things past
8. Small molecular bodyguards kill HPV-infected cancer cells by protecting tumor-suppressor
9. Research yields new clues to how brain cancer cells migrate and invade
10. Presence of fetal cells in women lowers risk of breast cancer but raises risk of colon cancer
11. Researchers Rejuvenate Blood-Forming Stem Cells in Mice
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/21/2017)... ... July 21, 2017 , ... ... Theater of Witness , was awarded a $300,000 grant from The Pew ... fosters empathy, comfort with ambiguity and the recognition of one’s own limits among ...
(Date:7/21/2017)... ... 2017 , ... The Margarian Law Firm has filed a class action ... for allegedly containing no ginger. Dr. Pepper produces the “Canada Dry” brand of ginger ... alleges Canada Dry Ginger Ale claims on its bottle that it is made from ...
(Date:7/21/2017)... (PRWEB) , ... July 21, 2017 , ... ... 4th-year medical students improve their chances of acceptance to a residency in a ... who have earned degrees outside the U.S. , According to data released by ...
(Date:7/21/2017)... CA (PRWEB) , ... July 21, 2017 , ... West ... “Tu” Tuantu Doan Vu, PA-C. Beginning July 17, 2017, Ms. Vu will join West ... 27 years of experience in dermatology, skin cancer , and more. She graduated ...
(Date:7/21/2017)... ... July 21, 2017 , ... How physicians ... on the rise, say researchers presenting their work at the American Orthopaedic ... “The combination of evaluating the patterns of change in concussion symptom presentation, diagnostic ...
Breaking Medicine News(10 mins):
(Date:7/13/2017)... WILLIAMSTON, Mich. , July 13, 2017  Centurion Medical Products, ... offers its DisImpactor ® fecal impaction removal device for hospice ... ... Patient pain management ... DisImpactor for Hospice can help alleviate patient pain while preventing unneeded ...
(Date:7/12/2017)... July 12, 2017 CarpalAID is a revolutionary new product ... surgery. Carpal tunnel syndrome affects more than 8 million ... the rate of men. The common methods of treating CTS are ... uncomfortable hand braces or gloves. ... CarpalAID is a clear patch worn on ...
(Date:7/11/2017)... , July 11, 2017  Bayer has awarded grants ... countries as part of its prestigious Bayer Hemophilia Awards Program ... of Philadelphia and Uniformed Services University ... are among the winners. Grant recipients were announced last night ... Hemostasis (ISTH) 2017 Congress, Berlin, Germany . ...
Breaking Medicine Technology: