The Expression of RTN1 in Lung Adenocarcinoma and Its Effect on Immune Microenvironment / 中国肺癌杂志

BACKGROUND@#Reticulosome family gene 1 (RTN1) is a reticulosome-encoding gene associated with the endoplasmic reticulum. RTN1 plays a key role in membrane trafficking or neuroendocrine secretion of neuroendocrine cells, while RTN1 serves as a potential diagnostic/therapeutic marker for neurological diseases and cancer. However, the expression of RTN1 and its effect on the immune microenvironment in patients with lung adenocarcinoma have not been reported. In this study, we aimed to investigate the expression of RTN1 in lung adenocarcinoma and its correlation with immune infiltration and survival in lung adenocarcinoma using public databases and bioinformatics network tools.@*METHODS@#Expression levels of RTN1 mRNA in tumor and normal tissues were analyzed using Tumor Immune Estimation Resource 2.0 (TIMER 2.0) and Gene Expression Profiling Interactive Analysis 2 (GEPIA 2). RTN1 protein expression was examined using the Human Protein Atlas. The clinical prognostic significance of RTN1 was analyzed using the GEPIA2 plotter database. To further confirm the potential function of RTN1, the data were analyzed using gene set enrichment analysis. In addition, We performed dimensionality-reduced clustering analysis at the single-cell sequencing level on two datasets from the Tumor Immune Single-cell Hub (TISCH) database to observe the cellular clustering of RTN1 in different types of immune cells. Using the TIMER online tool to analyze and predict the infiltration abundance of different types of immune cells in the immune microenvironment of lung adenocarcinoma patients in the TCGA cohort; TIMER and CIBERSORT were used to study the relationship between genes co-expressed with RTN1 and its associated tumor-infiltrating immune cells; finally, TIMER was used to analyze the relationship between RTN1 and immune correlations between immune checkpoints.@*RESULTS@#We found that RTN1 expression was decreased in patients with lung adenocarcinoma and was closely related to patient prognosis. RTN1 is involved in the process of phagosome formation, hematopoietic cell formation and cell adhesion, and plays an important role in T cell activation. Using cBioPortal and TCGA data to analyze, it is found that RTN1 is significantly associated with BTK, CD4, ECSF1R, MNDA, NCKAP1L and SNX20. High expression of the above genes may cause significant upregulation of CD4+ T cells, mast cells, monocytes, myeloid dendritic cells and M1 macrophages. The expression of RTN1 is closely related to the common immune checkpoints CD274, CTLA4, HAVCR2, LAG3, PDCD1, PDCD1LG2, TIGIT and SIGLEC15 immune checkpoints.@*CONCLUSIONS@#RTN1 may act as a tumor suppressor gene and indicate better prognosis. Furthermore, RTN1 is associated with immune infiltration that may be involved in the immunotherapy response in LUAD. However, the related mechanism needs further research.

Research on the anti-tumor effect of Plumbagin against human large cell lung cancer cell line NL9980 / 肿瘤研究与临床

Objective To investigate the anti-tumor effect and mechanism of Plumbagin against human large cell lung cancer cell line NL9980.Methods Plumbagin in different concentrations were set up to administrate NL9980 cell line.MTT test was performed to detect the inhibiting effects against tumor proliferation and IC50 concentration was identified.The influence of tumor apoptosis was observed by flow cytometry and the inhibiting effect against invasive ability was detected by Boyden chamber test.IC50 group and control group were set up and tumor cells were harvested 6 h,24 h and 48 h after administration.Realtime PCR was used to detect mRNA expression changes of bcl-2,bax,VEGF and CYCD1.Results MTT test showed obvious inhibiting effects of proliferation in NL9980 cell line and IC50 was 7.5 μmol/L.Plumbagin induced the apoptosis of tumor cells and showed a significant anti-invasive effect.Mean membrane-spanning cells were 161.59±47.32 and 26.58±9.07 in control group and IC50 group correspondingly.Down-regulations of bcl-2,VEGF and CYCD1 were detected and expression of bax gene increased.The effect of Plumbagin showed obvious time dependance (P ＜0.05).Conclusion Plumbagin has displayed the powerful antitumor effects against NL9980 cell line and it might work via multiple pathways.Plumbagin exhibits the prospect of being an effective drug against large cell lung cancer.