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Researchers
have
identified
a
“zombie”
gene
that
protects
elephants
from
cancer,
a
finding
that
may
pave
the
way
for
a
new
treatment
for
humans.
Globally,
nearly
1
in
6
human
deaths
occur
due
to
cancer,
whereas
less
than
5%
of
captive
elephants
who
also
live
for
about
70
years,
and
have
about
100
times
as
many
potentially
cancerous
cells
as
humans
die
of
the
disease.
Humans
and
elephants
have
one
copy
of
the
master
tumour
suppressor
gene
p53,
which
recognises
unrepaired
DNA
damage
a
precursor
of
cancer
and
causes
those
damaged
cells
to
die.
However,
the
researchers
from
the
University
of
Chicago
found
that
elephants
have
20
copies
of
p53.
This
makes
their
cells
significantly
more
sensitive
to
damaged
DNA
and
quicker
to
engage
in
cellular
suicide.
Moreover,
the
elephants
also
have
an
anti-cancer
gene
called
leukemia
inhibitory
factor
6
(LIF6)
that
returned
from
the
dead.
LIF6’s
function,
when
activated
by
p53,
is
to
respond
to
damaged
DNA
by
killing
the
cell.
“Genes
duplicate
all
the
time,”
said
Vincent
Lynch,
assistant
professor
at
the
varsity.
“Sometimes
they
make
mistakes,
producing
non-functional
versions
known
as
pseudogenes.
We
often
refer
to
these
dismissively
as
dead
genes,”
Lynch
added.
The
LIF6
gene
makes
a
protein
that
goes,
quite
rapidly,
to
the
mitochondria
the
cell’s
main
energy
source.
That
protein
pokes
holes
in
the
mitochondria,
causing
the
cell
to
die.
“Hence,
zombie,”
Lynch
said.
“This
dead
gene
came
back
to
life.
When
it
gets
turned
on
by
damaged
DNA,
it
kills
that
cell,
quickly.
This
is
beneficial,
because
it
acts
in
response
to
genetic
mistakes,
errors
made
when
the
DNA
is
being
repaired.
Getting
rid
of
that
cell
can
prevent
a
subsequent
cancer,”
he
noted,
in
the
paper
appearing
journal
Cell
Reports.
Elephants
have
eight
LIF
genes,
but
only
LIF6
is
known
to
be
functional.
This
defunct
gene
seems
to
have
emerged
around
the
time
wn
the
fossil
record
indicates
that
the
small
groundhog-sized
precursors
of
today’s
elephants
began
to
grow
bigger,
Lynch
said.
This
started
about
25
to
30
million
years
ago.
This
supplementary
method
of
suppressing
cancer
may
have
been
a
key
element
enabling
enormous
growth,
which
eventually
led
to
modern
elephants.
Exactly
how
LIF6
induces
apoptosis,
however,
remains
unclear.
This
will
be
“the
focus
of
continued
studies”,
the
researchers
said.
Researchers
have
identified
a
“zombie”
gene
that
protects
elephants
from
cancer,
a
finding
that
may
pave
the
way
for
a
new
treatment
for
humans.
Globally,
nearly
1
in
6
human
deaths
occur
due
to
cancer,
whereas
less
than
5%
of
captive
elephants
who
also
live
for
about
70
years,
and
have
about
100
times
as
many
potentially
cancerous
cells
as
humans
die
of
the
disease.
Humans
and
elephants
have
one
copy