The invention provides an application of combination of SPRC and a PD-1 or PD-L1 inhibitor in preparation of a
lung cancer immunotherapy sensitizing
drug, and relates to the technical field of
biomedicine.In the application, through in-vitro
cell experiments,
cell co-culture experiments and in-vivo animal experiments, S-
propargyl-L-
cysteine (SPRC) can play a sensitizing role in the anti-
lung cancer curative effect of the PD-1 inhibitor, and can be used for preparing a sensitizing
drug for
lung cancer immunotherapy. The core mechanism is as follows: 30 [mu] M SPRC is in a non-cytotoxic
dose window and can specifically inhibit IFN-gamma induced STAT1
phosphorylation and PD-L1 up-regulation by depending on a CSE / H2S pathway, while IFN-gamma-STAT1-PD-L1 is a core
signal axis of PD-L1 adaptive up-regulation in
lung cancer cells, and the
induction effect of TNF-alpha on PD-L1 is relatively weak; meanwhile, SPRC can inhibit activation of NF-kB induced by TNF-alpha and expression of
inflammatory factors such as IL-6 and IL-8 through the pathway so as to exert the anti-inflammatory effect, the CD8 +
T cell depletion proportion can be remarkably reduced by combining SPRC with anti-PD-1, the synergistic
tumor inhibition effect is formed, the effect is verified in in-vivo and in-vitro experiments, and a
closed loop of an in-vitro mechanism and an in-vivo
curative effect is achieved.