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Abstract Previous studies revealed that MIR155HG possessed an oncogenic role in many types of tumors including lung adenocarcinoma (LUAD), along with higher expression in tumors. However, in our study, we observed a positive correlation between MIR155HG expression and overall survival across different cohorts. The transferred PBMC on the NCG mouse model abrogated the tumor intrinsic oncogenic role of MIR155HG in LUAD. Upregulation of MIR155HG positively correlated with CD8+ T cell infiltration both in vitro and in vivo, as well as LUAD tissues. Mechanistically, we revealed that MIR155HG increased the cytokine CCL5 expression at the transcriptional level, which depended on the interaction between MIR155HG and YBX1 protein, a novel transcription factor of CCL5, resulting in the more protein stability of YBX1 through dampening ubiquitination. Additionally, we also observed that MIR155 could increase PD-L1 expression to hamper the activity of recruited CD8+ T cells, which could be rescued through PD-L1 mAb addition. Finally, we uncovered that patients with high MIR155HG expression had a higher response rate to immunotherapy, and the combination of MIR155HG overexpression and PD-L1 mAb increased the efficacy of PD-L1 mAb. Together, our study provides a novel biomarker and potential combination treatment strategy for patients who received immunotherapy.

Background It has been reported that smoking history as a predictor of immunotherapy efficacy in patients with advanced lung cancer, however, the underlying mechanisms of this phenomenon remain largely unknown.Methods The patients with lung adenocarcinoma’s (LUAD) cohort and the orthotopical transplanted mouse model were used to explore the correlation between smoking status and tertiary lymphoid structure (TLS) and chemokine CCL21, respectively. Cell adhesion and co-immunoprecipitation assays were performed to explore the interaction between CD4+T cells and CD20+B cells under tobacco exposure. Chromatin immunoprecipitation-PCR was used to dissect the mechanism of upregulated CCL21 secretion in tobacco treatment. Serum CCL21 level was recorded in patients with LUAD treated with immunotherapy.Results Here we observed that individuals with a smoking history exhibit an increased quantity and maturation level of TLS compared with non-smokers, along with higher levels of CCL21 secretion. Tobacco exposure promoted CCL21 expression in an epithelial cell-intrinsic manner, of which BaP, the main component of tobacco, facilitated the nuclear retention of the aryl hydrocarbon receptor that occupied the promoter of CCL21. Additionally, the activated CCL21/CCR7 axis increased the CD11a expression of CD4+T cells, boosting the interaction with CD20+B cells dependent on ICAM1, which potentially induced the TLSs formation. Patients with elevated serum levels of CCL21 benefited more from immunotherapy.Conclusions Patients with a smoking history exhibited higher levels of TLS via the CCL21-dependent mechanism, serum CCL21 was identified as a reliable biomarker for predicting the efficacy of immunotherapy.

Objective: To investigate the genetic mutation characteristics of non-small cell lung cancers (NSCLC) with and without lymph node metastasis.Methods: Primary lesions and metastatic lymph node lesions of 36 Chinese NSCLC patients were tested for somatic mutations, tumor mutation burden, phylogenetic and clonal evolutional analysis using a 1021-gene panel by next-generation sequencing (NGS) with an average sequencing depth of 671X.Results: In this study, eighteen patients with lung adenocarcinoma (LUAD) and 18 with lung squamous cell carcinoma (LUSC) were included. Different groups had distinct characteristics of gene mutations. CTNNB1 gene mutations were only present in Nome_LC LUAD patients (p < 0.05). ARID1A mutation was however the only gene with significant alterations (p < 0.05) in Nome_LC in LUSC. Phylogenetic trees of mutated genes were also constructed. Linear and parallel evolutions of metastatic lymph nodes were observed both in LUAD and LUSC.Conclusion: LUSC exhibited more genetic mutations than LUAD. Intriguingly, there was significant difference in gene mutations between Meta_LC and Nome_LC. CTNNB1 gene alteration was the key mutation in LUAD that seems to promote proliferation of the tumor and then determine T stage. On the other hand, proliferation of the tumor was characterized by ARID1A missense mutation in LUSC, thus influencing the T stage as well. Lymph node metastasis could display both linear and parallel evolutionary characteristics in NSCLC. Different metastatic lymph nodes might have exactly the same or different mutated genes, underlining the heterogeneous genomic characteristics of these cancer types.