Department of Internal Medicine
Contributions
Type: Publication Only
Background
Sirtuins are NAD(+)-dependent deacetylases with documented roles in gene expression, metabolic pathways, apoptosis, cell survival, DNA repair, development, inflammation, and healthy aging. SIRT6 is a sirtuin family member which has been implicated in the control of glucose uptake and metabolism, cell metabolism, genomic stability and DNA repair, and in inflammation. Aside for the observation that SIRT6 chromosomal locus is a region prone to chromosomal breaks in human acute myeloid leukemia, no data are available concerning the possible involvement of SIRT6 in leukemogenesis.
Aims
Herein, we have selected a series of novel and specific quinazolinedione small molecules SIRT6 inhibitors named S602, S603, and S610 and we have analyzed their in vitro effects on the T-ALL cell line Jurkat upon stimulation with anti-CD3/CD28 antibodies coated immunomagnetic beads to mimic tumor microenvironment signaling of the T-ALL cells.
Methods
After 24, 48 and 72 hours of stimulation in presence or absence of SIRT6 inhibitors we performed: a) a viability test with propidium iodide to determine whether these inhibitors affect cell survival; b) an assay for evaluating the content of ATP to determine whether the inhibitors alter the mitochondrial metabolic activity and therefore proliferation; c) an ELISA for TNF-α released on harvested supernatants
Results
We found that none of these inhibitors induced cell death or inhibited cell proliferation at concentrations raging between 10 and 100 µM. On the contrary, a strong and concentration dependent inhibition of TNFα production triggered by CD3 and CD28 co-engagement was observed. Notably, a marked reduction in intracellular ATP levels in Jurkat cells treated with the SIRT6 inhibitors could also be detected after a 72 h incubation.
Finally, SIRT6 inhibition resulted in a decrease in TNFα production in Jurkat cells line triggered through CD3 and CD28 co-engagement
Summary
Altogether, these findings suggest that inhibitors of SIRT6 can selectively affect the synthesis of ATP and thus the metabolic state of T-ALL cells. These inhibitors could be an useful tool when used together with pro-apoptotic anti-blastic drugs because of their complementation activity, affecting different molecular targets that are relevant for T-ALL cell growth.
In addition, TNFα production inhibition is expected to favorably affect the tumor microenvironment and to reduce invalidating systemic manifestations of disease, such as fever and cachexia, which typically worsen the clinical outcome of T-ALL patients.
Keyword(s): Cytokine, Leukemia cell line, Survival
Session topic: Publication Only
Type: Publication Only
Background
Sirtuins are NAD(+)-dependent deacetylases with documented roles in gene expression, metabolic pathways, apoptosis, cell survival, DNA repair, development, inflammation, and healthy aging. SIRT6 is a sirtuin family member which has been implicated in the control of glucose uptake and metabolism, cell metabolism, genomic stability and DNA repair, and in inflammation. Aside for the observation that SIRT6 chromosomal locus is a region prone to chromosomal breaks in human acute myeloid leukemia, no data are available concerning the possible involvement of SIRT6 in leukemogenesis.
Aims
Herein, we have selected a series of novel and specific quinazolinedione small molecules SIRT6 inhibitors named S602, S603, and S610 and we have analyzed their in vitro effects on the T-ALL cell line Jurkat upon stimulation with anti-CD3/CD28 antibodies coated immunomagnetic beads to mimic tumor microenvironment signaling of the T-ALL cells.
Methods
After 24, 48 and 72 hours of stimulation in presence or absence of SIRT6 inhibitors we performed: a) a viability test with propidium iodide to determine whether these inhibitors affect cell survival; b) an assay for evaluating the content of ATP to determine whether the inhibitors alter the mitochondrial metabolic activity and therefore proliferation; c) an ELISA for TNF-α released on harvested supernatants
Results
We found that none of these inhibitors induced cell death or inhibited cell proliferation at concentrations raging between 10 and 100 µM. On the contrary, a strong and concentration dependent inhibition of TNFα production triggered by CD3 and CD28 co-engagement was observed. Notably, a marked reduction in intracellular ATP levels in Jurkat cells treated with the SIRT6 inhibitors could also be detected after a 72 h incubation.
Finally, SIRT6 inhibition resulted in a decrease in TNFα production in Jurkat cells line triggered through CD3 and CD28 co-engagement
Summary
Altogether, these findings suggest that inhibitors of SIRT6 can selectively affect the synthesis of ATP and thus the metabolic state of T-ALL cells. These inhibitors could be an useful tool when used together with pro-apoptotic anti-blastic drugs because of their complementation activity, affecting different molecular targets that are relevant for T-ALL cell growth.
In addition, TNFα production inhibition is expected to favorably affect the tumor microenvironment and to reduce invalidating systemic manifestations of disease, such as fever and cachexia, which typically worsen the clinical outcome of T-ALL patients.
Keyword(s): Cytokine, Leukemia cell line, Survival
Session topic: Publication Only