- Scientists from Harvard Medical School identify
certain cancers that feed on fat for energy.
cancer and acute myeloid leukemia have been found to feed on
- PHD3 protein controls pathway which controls fat
- Increase of PHD3 in tumor cell lines leads to cell
always been thought of as feeding on sugar for their growth but now scientists
from The Harvard School of Medicine have found that some cancers feed on fat
Senior author Dr. Marcia Haigis who is an
associate professor of cell biology at Harvard Medical School said "This really
represents a new frontier in looking at the metabolism of cancer. Understanding
the molecular handle of this pathway is the first step toward translating the
basic work into therapy."
‘Restricting utilization of fat could starve certain cancers.’
Cancer and Sugar
Cancers are found to feed on sugar molecules
and utilize the energy to grow. Cancer cells take up glucose 1-12 times more
than normal cells, displaying a very high metabolic rate.
The affinity of cancer cells to sugar
molecules is utilized in the Positron Emission Tomography (PET) scan
which allows advanced imaging of the body and the
identification of cancer cells in the body.
PET is conducted by drinking glucose labeled
with radioactive material which is carried by the body to all its parts. The
glucose is preferentially picked up by the tumor cells which are detected by
imaging systems. This helps in identifying the presence of cancer cells in the
Cancer cells break down the glucose molecules
at a faster rate than normal cells, utilizing the energy as fuel.
Cancer Cells and Fat
Scientists from the Harvard School of
Medicine have found that some cancers could be using fat as fuel, changing the
perception on cancers. In a normal human, carbohydrates and sugars are first
broken down into smaller units and utilized for energy, storing fats for use
when sugars are not available. There exist specific signaling pathways that
block the utilization of fat for fuel.
Prolyl Hydroxylase 3 (PHD3) and Fat Burning
The protein prolyl hydroxylase 3 (PHD3) is
found to regulate fat burning by blocking pathways that are utilized to break
down fats. The scientists found that in cancers like prostate
and acute myeloid leukemia
, this protein was
found to be in low concentration.
Fat burning in normal humans is triggered
when there is a low concentration of sugars or when the energy levels are low.
This can lead to the activation of a protein called AMP-activated protein
kinase (AMPK) that further activates the enzyme acetyl CoA carboxylase (ACC).
This leads to the burning of fat. The body holds on to its fat even under
considerable stress as it is the storehouse of energy and to help the body tide
over possible episodes of lack of nutrition. However, this could be reversed in
certain forms of cancer, according to Harvard Medical School Scientists.
Evidence to Support that Certain Cancers
Experiment to suppress PHD3
: The scientists carried out
experiments where the protein PHD3 was suppressed, they found that this protein
suppressed and modified ACC2, preventing the burning of fat.
Researching previous data
: The scientists studied data
related to cancers and found that cancers that depended on sugar had high level
of PHD3 while cancers that depended on fats had low level of PHD3.
Testing effect of PHD3 on tumor cell Lines
: In an effort to understand the
importance of PHD3 on tumor cell lines of mice, it was found that
- Cancer cells stopped growing
the cancer cells died
When asked about the future prospects of this
discovery, Dr. Haigis adds "That was really exciting. We've altered a lot of
metabolic pathways in cancer, and this is one of the few pathways we've
modulated where we really see the tumors die. They are so dependent on fat
oxidation that they die. What do fats provide to tumors that other fuels don't?
That's one open question, and this is only the first chapter in the story."
The study holds promise for therapy that can
be aimed at starving certain cancers which will arrest their growth and lead to
their termination. However, there are considerable steps to take before this
study will be available for human therapy, though the promises they offer are
- 5 Reasons Cancers and Sugars are Best
Friends - (http://beatcancer.org/blog-posts/5-reasons-cancer-and-sugar-are-best-friends/)