ABSTRACT
ObjectiveTo study the effect and mechanism of Xiangsha Liu Junzitang combined with phlegm-removing and detoxifying traditional Chinese medicine on immune escape in Lewis lung cancer mice. MethodA total of 60 specific-pathogen-free （SPF）-grade C57BL/6J male mice were injected subcutaneously with 0.2 mL of Lewis cell suspension （containing 2×106 cells·mL-1） in the right mid-axillary line. After 7 days， the mice that had been successfully modeled were randomly divided into six groups： the model group， the cisplatin group， the Xiangsha Liu Junzitang low-， medium-， and high-dose groups， and the combined group， with 10 mice in each group. The Xiangsha Liu Junzitang low-， medium- and high-dose groups were gavaged with 17.88， 35.75， 71.50 g·kg-1 Xiangsha Liu Junzitang solution once a day， respectively， and the dosage of cisplatin intraperitoneally injected into the mice was converted to 5 mg·kg-1 twice a week， and the tumour volumes of each group were measured every two days. The intervention lasted for 14 consecutive days. At the end of treatment， the tumour mass of mice in each group was weighed and the tumour inhibition rate was calculated. The morphological characteristics of tumours in each group were observed by hematoxylin-eosin （HE） staining. Fluorescent quantitative real-time polymerase chain reaction （Real-time PCR） assay was used to detect messenger ribonucleic acid （mRNA） contents of the natural killer group 2 member D （NKG2D） receptor， ribonucleic acid export-1 （RAE-1）， and γ interferon （IFN-γ） in the tumour tissues of each group. NKG2D， RAE-1， and IFN-γ mRNA in tumour tissues of each group. Immunohistochemistry （IHC） and Western blot were applied to detect the expressions of RAE-1， NKG2D， and IFN-γ in tumour tissues of each group， and Western blot was used to detect the expressions of interleukin-6 （IL-6）， Janus kinase 2 （JAK2）， p-JAK2， signal transducer and activator of transcription 3 （STAT3）， and p-STAT3 in tumour tissues of each group， as well as the protein levels of NKG2D， and RAE-1 in spleen tissues of each group. ResultCompared with that in the model group， the tumour mass decreased in all dose groups of Xiangsha Liu Junzitang， with no statistically significant difference. The tumour volume was reduced （P<0.05， P <0.01）. The pathological morphology was improved. The mRNA contents of NKG2D， RAE-1 and IFN-γ were increased in the medium-dose group （P<0.05， P<0.01）， and the protein expressions of NKG2D， RAE-1， and IFN-γ in tumour tissues were elevated （P<0.05， P<0.01）， and p-JAK2 and p-STAT3 protein expressions were decreased （P<0.05， P<0.01）. In spleen tissues， the protein expressions of NKG2D and RAE-1 in all dose groups of Xiangsha Liu Junzitang were significantly elevated （P<0.01）. Compared with those in the cisplatin group， NKG2D， RAE-1 and IFN-γ mRNA contents were elevated in the middle-dose group of Xiangsha Liu Junzitang， and the difference was not statistically significant. IHC showed that the protein expressions of NKG2D and IFN-γ in the combined group were significantly elevated （P<0.01）， and Western blot results showed that the protein expressions of RAE-1， NKG2D and IFN-γ were elevated （P<0.05， P<0.01）. p-JAK2 and p-STAT3 protein expressions were decreased in the combined group （P<0.05， P<0.01）. NKG2D and RAE-1 protein expressions were significantly increased in spleen tissues of the medium-dose groups and the combined group （P<0.01）. ConclusionXiangsha Liu Junzitang combined with phlegm-removing and detoxifying traditional Chinese medicine can inhibit the growth of tumours in Lewis lung cancer mice by up-regulating the expressions of RAE-1/NKG2D， promoting the activation of NK cells， and inhibiting immune escape， the mechanism of which may be related to down-regulation of the JAK2/STAT3 pathway.