Hunting a Killer
Cell Biologist Yuri Lazebnik: Pursuing the Roots of Cancer
Yuri Lazebnik Fuses Cells
Cell biologist Lazebnik explores links between cell fusion and cancer.
Is rare in most healthy cells
Can cause genetic changes
May be linked to cancer
What is another name for cell suicide?
Apoptosis under normal conditions
Sculpts fingers and toes
Streamlines nerve connections in brain during development
Removes old, worn-out cells from the body
Hunting Down a Serial Killer
Move into neighboring tissues
Damage or shut down vital organs
Can be deadly
Don't die off like normal cells do
What makes cancer cells act like they do?
Investigation Guided by Surprise
David Rubenstein, a high school student working in Lazebnik's lab as part of Cold Spring Harbor Laboratory's Partner's for the Future program, sets up an experiment with a normal cell and a cancer-prone cell.
The experiment yielded a surprise finding: new cells that appeared to be fused together.
Rubenstein repeats the experiment and gets the same results.
Lazebnik starts investigating cell fusion
Only five known examples of healthy cell fusion
Fertilized eggs are the only fused cells that continue to divide
Sometimes, healthy cells accidentally fuse
Name the five known examples of healthy cell fusion.
What would happen if other healthy fused cells continued to divide?
Do accidentally fused cells continue to divide?
Spontaneous Cell Fusion
Some cancerous and cancer-prone cells
Do not avoid cell fusion like normal cells
Readily merge together
Continue to reproduce
Could be the cause of diversity of cells with unpredictable characteristics in tumors
What Makes Cells Fuse?
Lazebnik and Duelli investigate genes and molecules in fused cells
Hypothesis: The virus might trigger cell fusion.
Hypothesis: Some of the mutations can chart a course toward cancer.
Observation #2: Fused cells develop genetic changes, or mutations.
Observation #1: Cancer-prone cells squirt out a virus that causes an AIDS-like disease in monkeys.
Viruses Can Make Cells Fuse
Measles and mumps viruses cause a type of cell fusion
Also seen in some types of cancer
Don't continue to divide; die and are reabsorbed by the body
≥10% cancers at least partially caused by viruses
Human papillomavirus (HPV)
Hepatitis B and C
Epstein-Barr virus (mononucleosis, or "mono")
What are syncytia?
Is there a link between viruses and cancer?
Questions About Viruses
Do all cancer-causing viruses turn into cancer?
No. Only 1-2% of women with HPV develop cervical cancer.
Can scientists prevent virus-caused cancers by developing vaccines against the viruses?
In some cases, yes. Vaccines already exist for HPV and hepatitis B.
What factors other than viruses contribute to cancer?
Do viruses cause some of our cells to fuse?
Does cell fusion cause, or contribute to, cancer?
What We Know
What We Don't Know
What are the implications of using viruses as vehicles to deliver genes or medications to specific tissues if such a strategy relies on cell fusion?