Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
PZ HTL SA
GLOBETECH PUBLISHING LLC

Disruption of Mitochondrial Enzyme Function Characterizes Some Cancers

By BiotechDaily International staff writers
Posted on 02 Jan 2012
Since mutations in the genome of cancer cells often force tumors to use metabolic pathways not found in normal cells, cancer researchers believe that drugs targeting these pathways will be able to destroy tumors with fewer adverse side effects.

Some tumors harbor mutations in the citric acid cycle (CAC or Krebs cycle) or electron transport chain (ETC) that disable normal oxidative mitochondrial function. In this regard investigators at Emory University (Atlanta, GA, USA) studied the relationship between the enzyme PDHK1 (pyruvate dehydrogenase kinase 1), an important point of control for cancer cell metabolism, and the tyrosine kinase FGFR1 (fibroblast growth factor receptor 1), which is activated in several types of cancer.

They reported in the December 23, 2011, online edition of the journal Molecular Cell that tyrosine phosphorylation enhanced PDHK1 kinase activity by promoting ATP and pyruvate dehydrogenase complex (PDC) binding. Functional PDC formed in mitochondria outside of the matrix in some cancer cells.

Expression of a mutant, nonfunctional form of PDHK1 in cancer cells led to decreased cell proliferation under hypoxia and increased oxidative phosphorylation with enhanced mitochondrial utilization of pyruvate and reduced tumor growth in xenograft nude mice.

“We and others have shown that PDHK is upregulated in several types of human cancer, and our findings demonstrate a new way that PDHK activity is enhanced in cancer cells,” said senior author Dr. Jing Chen, associate professor of hematology and medical oncology at Emory University School. “PDHK is a very attractive target for anticancer therapy because of its role in regulating cancer metabolism. We used FGFR1 as a platform to look at how metabolic enzymes are modified by oncogenic tyrosine kinases. We discovered that several oncogenic tyrosine kinases activate PDHK, and we found that many of those tyrosine kinases are found within mitochondria.”

The experimental drug dichloroacetate (DCA), which inactivates PDHK, is being evaluated in clinical trials while researchers continue to seek other, more potent inhibitors of PDHK.

Related Links:
Emory University



comments powered by Disqus

Channels

Drug Discovery

view channel
Image: The nano-cocoon drug delivery system is biocompatible, specifically targets cancer cells, can carry a large drug load, and releases the drugs very quickly once inside the cancer cell. Ligands on the surface of the \"cocoon\" trick cancer cells into consuming it. Enzymes (the “worms\" in this image) inside the cocoon are unleashed once inside the cell, destroying the cocoon and releasing anticancer drugs into the cell (Photo courtesy of Dr. Zhen Gu, North Carolina State University).

Novel Anticancer Drug Delivery System Utilizes DNA-Based Nanocapsules

A novel DNA-based drug delivery system minimizes damage to normal tissues by utilizing the acidic microenvironment inside cancer cells to trigger the directed release of the anticancer drug doxorubicin (DOX).... Read more

Lab Technologies

view channel

Experimental Physicists Find Clues into How Radiotherapy Kills Cancer Cells

A new discovery in experimental physics has implications for a better determination of the process in which radiotherapy destroys cancer cells. Dr. Jason Greenwood from Queen’s University Belfast (Ireland) Center for Plasma Physics collaborated with scientists from Italy and Spain on the work on electrons, and published... Read more

Business

view channel

Interest in Commercial Applications for Proteomics Continues to Grow

Increasing interest in the field of proteomics has led to a series of agreements between private proteomic companies and academic institutions as well as deals between pharmaceutical companies and novel proteomics innovator biotech companies. Proteomics is the study of the structure and function of proteins.... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.