Radiotherapy exerts its effects on tumor cells directly by damaging their DNA and consequently activating a programmed cell death process(apoptosis)and indirectly by stimulating an immune response towards tumor antige...Radiotherapy exerts its effects on tumor cells directly by damaging their DNA and consequently activating a programmed cell death process(apoptosis)and indirectly by stimulating an immune response towards tumor antigens.Tumor cells are known to activate several mechanisms to preserve their survival and limit the host response,including resistance to apoptosis and immune evasion.Recently,Han et al.1 published that to limit the induction of the host immune response,tumor cells can exploit the intrinsic apoptosis program rather than block it,an apparent paradox.When exposed to the caspase inhibitor emricasan,which blocks this immune-evasion mechanism,tumor cells“adopt”countermeasures by upregulating the expression of PD-L1,which negatively controls immune responses.To eliminate this additional tumor adaptive reaction and protect the animals from tumor growth,the authors used a combination of radiation,caspase inhibition,and immune checkpoint inhibitor(anti-PD-L1 antibody)treatment.展开更多
文摘Radiotherapy exerts its effects on tumor cells directly by damaging their DNA and consequently activating a programmed cell death process(apoptosis)and indirectly by stimulating an immune response towards tumor antigens.Tumor cells are known to activate several mechanisms to preserve their survival and limit the host response,including resistance to apoptosis and immune evasion.Recently,Han et al.1 published that to limit the induction of the host immune response,tumor cells can exploit the intrinsic apoptosis program rather than block it,an apparent paradox.When exposed to the caspase inhibitor emricasan,which blocks this immune-evasion mechanism,tumor cells“adopt”countermeasures by upregulating the expression of PD-L1,which negatively controls immune responses.To eliminate this additional tumor adaptive reaction and protect the animals from tumor growth,the authors used a combination of radiation,caspase inhibition,and immune checkpoint inhibitor(anti-PD-L1 antibody)treatment.
