ObjectiveTo investigate whether the inhibitory effect of Panax quinquefolium saponins （PQS） on non-small cell lung cancer （NSCLC） is enhanced under graphene-mediated far-infrared therapy （GFIR）， and to analyze its relationships with mitochondrial dysfunction， mitochondrial DNA （mtDNA） leakage， and the activation of cyclic GMP-AMP synthase （cGAS）/stimulator of interferon genes （STING） signaling pathways. MethodsIn the cell experiments， the cell-counting kit 8 （CCK-8） was employed to assess the inhibitory effects of PQS alone or in combination with GFIR （PQS+GFIR） on A549 cell viability. The scratch assay and the colony formation assay were adopted to evaluate cell migration and colony formation capabilities， respectively. Flow cytometry was employed to assess apoptosis， mitochondrial membrane potential， and reactive oxygen species （ROS） levels. Immunofluorescence （IF） assay was performed to assess mitochondrial localization. Real-time polymerase China reaction（PCR） was used to detect mitochondrial DNA （mtDNA） leakage. A STING knockdown cell model was established by transfecting cells with small interfering RNA （siRNA）， and the knockdown efficiency was assessed by Real-time PCR and Western blot. The cell viability and apoptosis following gene knockdown were assessed through the CCK-8 assay and flow cytometry. In the animal experiments， an allogeneic xenograft mouse model was established with Lewis lung cancer cells. Mice were randomized into a control group， a model group， a cisplatin group， a low-dose PQS （PQS-Low， 90 mg·kg^-1） group， a high-dose PQS （PQS-High， 180 mg·kg^-1） group， a low-dose PQS combined with GFIR （PQS-Low+GFIR， 90 mg·kg^-1） group， and a high-dose PQS combined with GFIR （PQS-High+GFIR， 180 mg·kg^-1） group. Treatment lasted for 14 days， and the fluorescence intensity was monitored at the tumor site by small-animal in vivo imaging during the treatment period. Flow cytometry was utilized to determine the proportions of T-lymphocyte subsets， B-lymphocyte levels， and peripheral blood NK cell levels in the spleens of mice. Immunohistochemical （IHC） staining was performed to assess the infiltration of CD3⁺， CD4⁺， and CD8⁺ T-lymphocytes in the tumor tissue. Enzyme-linked immunosorbent assay （ELISA） was conducted to measure the levels of interferon-α （IFN-α）， interferon-β （IFN-β）， tumor necrosis factor-α （TNF-α）， and interleukin-6 （IL-6） in mouse tumors. The mRNA levels of cGAS， STING， TANK-binding kinase 1 （TBK1）， interferon regulatory factor 3 （IRF3）， interferon beta 1 （IFNB1）， and nuclear factor κB p65 （NF-κB p65） were determined by Real-time PCR. The protein levels of cGAS， STING， p-STING， TBK1， p-TBK1， IRF3， p-IRF3， NF-κB p65， and p-NF-κB p65 were quantified via Western blot. ResultsThe cell experiment results showed that compared with the control group， PQS inhibited the viability and migration of A549 cells， promoted apoptosis， affected mitochondrial localization， reduced mitochondrial membrane potential， increased the ROS level， and promoted mtDNA leakage. Following STING knockdown， the reductions in cell viability and the apoptosis-inducing effects caused by PQS were partially reversed （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group showed inhibited A549 cell migration and colony formation， exacerbated apoptosis， downregulated mitochondrial membrane potential， elevated ROS levels， and promoted mtDNA leakage. After STING knockdown， the reduced A549 cell viability and abnormal apoptosis phenotype were further reversed （P<0.05， P<0.01）. The animal experiment results showed that compared with the control group， the model group mice exhibited reduced proportions of T-lymphocyte subsets， CD19⁺ B-lymphocyte levels， and peripheral blood NK1.1⁺ cell levels in the spleen （P<0.01）. Compared with the model group， the PQS group showed increased immune cell parameters in mice （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group exhibited enhanced levels of the aforementioned indicators （P<0.01）. Compared with the model group， the PQS group showed significantly reduced fluorescence intensity in transplanted tumors， significantly upregulated expression of CD3 and CD4 in the tumor tissue， elevated levels of IFN-α and IL-6 in tumors， and upregulated mRNA levels of cGAS， STING， TBK1， IRF3， IFNB1， and NF-κB p65 as well as upregulated protein level of cGAS and phosphorylation level of STING in tumors （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group demonstrated further reduced tumor fluorescence intensity， elevated levels of CD3， CD4， and CD8 as well as cytokine levels in tumor tissue， and upregulated mRNA levels of genes related to the cGAS/STING pathway as well as upregulated protein level of cGAS and phosphorylation levels of STING， TBK1， IRF3， and NF-κB p65 （P<0.05， P<0.01） ConclusionGFIR enhances the inhibitory effect of PQS on NSCLC， potentially through mitochondrial dysfunction， mtDNA leakage， and activation of the cGAS/STING signaling pathway.

ObjectiveTo investigate whether the inhibitory effect of Panax quinquefolium saponins （PQS） on non-small cell lung cancer （NSCLC） is enhanced under graphene-mediated far-infrared therapy （GFIR）， and to analyze its relationships with mitochondrial dysfunction， mitochondrial DNA （mtDNA） leakage， and the activation of cyclic GMP-AMP synthase （cGAS）/stimulator of interferon genes （STING） signaling pathways. MethodsIn the cell experiments， the cell-counting kit 8 （CCK-8） was employed to assess the inhibitory effects of PQS alone or in combination with GFIR （PQS+GFIR） on A549 cell viability. The scratch assay and the colony formation assay were adopted to evaluate cell migration and colony formation capabilities， respectively. Flow cytometry was employed to assess apoptosis， mitochondrial membrane potential， and reactive oxygen species （ROS） levels. Immunofluorescence （IF） assay was performed to assess mitochondrial localization. Real-time polymerase China reaction（PCR） was used to detect mitochondrial DNA （mtDNA） leakage. A STING knockdown cell model was established by transfecting cells with small interfering RNA （siRNA）， and the knockdown efficiency was assessed by Real-time PCR and Western blot. The cell viability and apoptosis following gene knockdown were assessed through the CCK-8 assay and flow cytometry. In the animal experiments， an allogeneic xenograft mouse model was established with Lewis lung cancer cells. Mice were randomized into a control group， a model group， a cisplatin group， a low-dose PQS （PQS-Low， 90 mg·kg^-1） group， a high-dose PQS （PQS-High， 180 mg·kg^-1） group， a low-dose PQS combined with GFIR （PQS-Low+GFIR， 90 mg·kg^-1） group， and a high-dose PQS combined with GFIR （PQS-High+GFIR， 180 mg·kg^-1） group. Treatment lasted for 14 days， and the fluorescence intensity was monitored at the tumor site by small-animal in vivo imaging during the treatment period. Flow cytometry was utilized to determine the proportions of T-lymphocyte subsets， B-lymphocyte levels， and peripheral blood NK cell levels in the spleens of mice. Immunohistochemical （IHC） staining was performed to assess the infiltration of CD3⁺， CD4⁺， and CD8⁺ T-lymphocytes in the tumor tissue. Enzyme-linked immunosorbent assay （ELISA） was conducted to measure the levels of interferon-α （IFN-α）， interferon-β （IFN-β）， tumor necrosis factor-α （TNF-α）， and interleukin-6 （IL-6） in mouse tumors. The mRNA levels of cGAS， STING， TANK-binding kinase 1 （TBK1）， interferon regulatory factor 3 （IRF3）， interferon beta 1 （IFNB1）， and nuclear factor κB p65 （NF-κB p65） were determined by Real-time PCR. The protein levels of cGAS， STING， p-STING， TBK1， p-TBK1， IRF3， p-IRF3， NF-κB p65， and p-NF-κB p65 were quantified via Western blot. ResultsThe cell experiment results showed that compared with the control group， PQS inhibited the viability and migration of A549 cells， promoted apoptosis， affected mitochondrial localization， reduced mitochondrial membrane potential， increased the ROS level， and promoted mtDNA leakage. Following STING knockdown， the reductions in cell viability and the apoptosis-inducing effects caused by PQS were partially reversed （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group showed inhibited A549 cell migration and colony formation， exacerbated apoptosis， downregulated mitochondrial membrane potential， elevated ROS levels， and promoted mtDNA leakage. After STING knockdown， the reduced A549 cell viability and abnormal apoptosis phenotype were further reversed （P<0.05， P<0.01）. The animal experiment results showed that compared with the control group， the model group mice exhibited reduced proportions of T-lymphocyte subsets， CD19⁺ B-lymphocyte levels， and peripheral blood NK1.1⁺ cell levels in the spleen （P<0.01）. Compared with the model group， the PQS group showed increased immune cell parameters in mice （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group exhibited enhanced levels of the aforementioned indicators （P<0.01）. Compared with the model group， the PQS group showed significantly reduced fluorescence intensity in transplanted tumors， significantly upregulated expression of CD3 and CD4 in the tumor tissue， elevated levels of IFN-α and IL-6 in tumors， and upregulated mRNA levels of cGAS， STING， TBK1， IRF3， IFNB1， and NF-κB p65 as well as upregulated protein level of cGAS and phosphorylation level of STING in tumors （P<0.05， P<0.01）. Compared with the PQS group， the PQS+GFIR group demonstrated further reduced tumor fluorescence intensity， elevated levels of CD3， CD4， and CD8 as well as cytokine levels in tumor tissue， and upregulated mRNA levels of genes related to the cGAS/STING pathway as well as upregulated protein level of cGAS and phosphorylation levels of STING， TBK1， IRF3， and NF-κB p65 （P<0.05， P<0.01） ConclusionGFIR enhances the inhibitory effect of PQS on NSCLC， potentially through mitochondrial dysfunction， mtDNA leakage， and activation of the cGAS/STING signaling pathway.