Antibiotics may help to treat melanoma

Date:
July 22, 2021
Source:
KU Leuven
Summary:
Some antibiotics appear to be effective against a form of skin
cancer known as melanoma. Researchers examined the effect of these
antibiotics on patient-derived tumors in mice.



FULL STORY ==========================================================================
Some antibiotics appear to be effective against a form of skin cancer
known as melanoma. Researchers at KU Leuven, Belgium, examined the effect
of these antibiotics on patient-derived tumours in mice. Their findings
were published in the Journal of Experimental Medicine.


========================================================================== Researchers from KU Leuven may have found a new weapon in the fight
against melanoma: antibiotics that target the 'power plants' of cancer
cells. These antibiotics exploit a vulnerability that arises in tumour
cells when they try to survive cancer therapy.

"As the cancer evolves, some melanoma cells may escape the treatment
and stop proliferating to 'hide' from the immune system. These are
the cells that have the potential to form a new tumour mass at a later
stage" explains cancer researcher and RNA biologist Eleonora Leucci (KU Leuven). "In order to survive the cancer treatment however, those inactive cells need to keep their 'power plants' -- the mitochondria -- switched
on at all times." As mitochondria derive from bacteria that, over time,
started living inside cells, they are very vulnerable to a specific class
of antibiotics. This is what gave us the idea to use these antibiotics as anti-melanoma agents." The researchers implanted patient-derived tumours
into mice, which were then treated with antibiotics -- either as the only treatment or in combination with existing anti-melanoma therapies. Leucci:
"The antibiotics quickly killed many cancer cells and could thus be used
to buy the precious time needed for immunotherapy to kick in. In tumours
that were no longer responding to targeted therapies, the antibiotics
extended the lifespan of -- and in some cases even cured -- the mice."
The researchers worked with antibiotics that are now, because of rising antibiotic resistance, only rarely used in bacterial infection. However,
this resistance has no effect on the efficacy of the treatment in this
study, explains Leucci. "The cancer cells show high sensitivity to these antibiotics, so we can now look to repurpose them to treat cancer instead
of bacterial infections." However, patients with melanoma shouldn't
start experimenting, warns Leucci.

"Our findings are based on research in mice, so we don't know how
effective this treatment is in human beings. Our study mentions
only one human case where a melanoma patient received antibiotics
to treat a bacterial infection, and this re-sensitised a resistant
melanoma lesion to standard therapy. This result is cause for
optimism, but we need more research and clinical studies to
examine the use of antibiotics to treat cancer patients. Together
with oncologist Oliver Bechter (KU Leuven/UZ Leuven), who is a
co-author of this study, we are currently exploring our options." ========================================================================== Story Source: Materials provided by KU_Leuven. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Roberto Vendramin, Vicky Katopodi, Sonia Cinque, Angelina Konnova,
Zorica
Knezevic, Sara Adnane, Yvessa Verheyden, Panagiotis Karras, Ewout
Demesmaeker, Francesca M. Bosisio, Lukas Kucera, Jan Rozman, Ivan
Gladwyn-Ng, Lara Rizzotto, Erik Dassi, Stefania Millevoi, Oliver
Bechter, Jean-Christophe Marine, Eleonora Leucci. Activation
of the integrated stress response confers vulnerability to
mitoribosome-targeting antibiotics in melanoma. Journal of
Experimental Medicine, 2021; 218 (9) DOI: 10.1084/jem.20210571 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/07/210722112942.htm

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