NSCLC is a very aggressive solid tumor, with a poor prognosis due to post-surgical recurrence. Analysis of the specific tumor and immune signatures of NSCLC samples is a critical step in prognostic evaluation and management decisions for patients after surgery. Routine histological assays have some limitations. Therefore, new diagnostic tools with the capability to quickly recognize NSCLC subtypes and correctly identify various markers are needed. We developed a technique for ex vivo isolation of cancer and immune cells from surgical tumor and lung tissue samples of patients with NSCLC (adenocarcinomas and squamous cell carcinomas) and their examination on ex vivo cell preparations and, parallelly, on histological sections after Romanovsky–Giemsa and immunofluorescent/immunochemical staining for cancer-specific and immune-related markers. As a result, PD-L1 expression was detected for some patients only by ex vivo analysis. Immune cell profiling in the tumor microenvironment revealed significant differences in the immunological landscapes between the patients’ tumors, with smokers’ macrophages with simultaneous expression of pro- and anti-inflammatory cytokines, neutrophils, and eosinophils being the dominant populations. The proposed ex vivo analysis may be used as an additional diagnostic tool for quick examination of cancer and immune cells in whole tumor samples and to avoid false negatives in histological assays.

Smoking is an established risk factor for a variety of malignant tumors, the most well-known of which is lung cancer. Various molecular interactions are known to link tobacco smoke exposure to lung cancer, but new data are still emerging on the effects of smoking on lung cancer development, progression, and tumor response to therapy. In this study, we reveal in further detail the previously established association between smoking and hsa-mir-301a activity in lung squamous cell carcinoma, LUSC. Using different bioinformatic tools, we identified IRF1 as a key smoking-regulated target of hsa-mir-301a in LUSC. We further confirmed this relationship experimentally using clinical LUSC tissue samples and intact lung tissue samples. Thus, increased hsa-mir-301a levels, decreased IRF1 mRNA levels, and their negative correlation were shown in LUSC tumor samples. Additional bioinformatic investigation for potential pathways impacted by such a mechanism demonstrated IRF1’s multifaceted role in controlling the antitumor immune response in LUSC. IRF1 was then shown to affect tumor immune infiltration, the expression of immune checkpoint molecules, and the efficacy of immune checkpoint blockade therapy. As a result, here we suggest a smoking-regulated mir301a/IRF1 molecular axis that could modulate the antitumor immune response and immunotherapy efficacy in LUSC, opening up novel opportunities for future research.

Activating mutations of EGFR are associated with sensitivity of non-small cell lung cancer (NSCLC ) to tyrosine kinase inhibitors (TKI). Liquid biopsy using circulating cell-free tumor DNA (cfDNA) is proposed in cases when formalin fixed paraffin embedded (FFPE) tumor tissue is not available and for monitoring of EGFR status. In the study we evaluated new qPC R assay for EGFR mutations in plasma cfDNA. Sensitivity of the assay was 1 % of the mutant allele for L858R, L861Q, S768I mutations and deletions in exon 19, and 5 % of the mutant allele for G719X or T790M mutations Before surgery, mutation was detected in plasma of 4 out of 7 patients (57 %) with mutant EGFR in FFPE tumor tissue. Mutations found in cfDNA completely matched those found in tumor tissue in 2 cases. In one case with G719X and S768I mutations in FFPE tissue, only S768I was found in cfDNA. In another case, T790M was detected in plasma in addition to L858R that was present in tumor tissue. No EGFR mutations were detected in plasma DNA from 12 healthy volunteers and 13 cases of NSCLC with wt EGFR suggesting 100 % specificity of the assay. Liquid biopsy detected EGFR mutations in cfDNA in 8 of 16 cases of NSCLC with mutant EGFR being under therapy with TKI. Among them, 7 cases had mutations in liquid biopsy that matched those in tumor tissue and another case had T790M in addition to L858R. In 3 cases increased mutant allele frequency was detected 212 months before clinical progression.

NSCLC is a very aggressive solid tumor, with a poor prognosis due to post-surgical recurrence. Analysis of the specific tumor and immune signatures of NSCLC samples is a critical step in prognostic evaluation and management decisions for patients after surgery. Routine histological assay has some limitations. Therefore, new diagnostic tools with the capability to quickly recognize NSCLC subtypes and correctly identify various markers are needed. We developed a technique for ex vivo expansion of cancer and immune cells from surgical tumor and lung tissue samples of patients with NSCLC (adenocarcinomas and squamous cell carcinomas) and their examination on ex vivo cell preparations and, parallelly, on histological sections after Romanovsky–Giemsa and immunofluorescent/immunochemical staining for cancer-specific and immune-related markers. As a result, PD-L1 expression was detected for some patients only by ex vivo analysis. Immune cell profiling in the tumor microenvironment revealed significant differences in the immunological landscapes between the patients’ tumors, with smokers’ macrophages with simultaneous expression of pro- and anti-inflammatory cytokines, neutrophils, and eosinophils being the dominant populations. The proposed ex vivo analysis may be used as an additional diagnostic tool for quick examining cancer and immune cells in whole tumor samples and avoiding false negatives in histological assays.

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). However, the limited predictive value of PD-L1 expression as a biomarker underscores the urgent need for more reliable predictors of ICI response. Interferon regulatory factor 1 (IRF1) is a transcription factor that lies downstream of interferon-γ signaling and directly regulates CD274 (PD-L1) transcription. Here, we performed a comprehensive bioinformatic analysis to identify microRNAs (miRNAs) that may be associated with IRF1 expression in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). Using data from The Cancer Genome Atlas (TCGA), we identified 20 miRNAs whose expression levels consistently and negatively correlated with IRF1 mRNA levels in both LUAD and LUSC. Among these, only hsa-miR-301b possesses conserved binding sites in the 3′UTR of IRF1 mRNA, suggesting direct post-transcriptional repression. For the remaining 19 miRNAs, we hypothesized an indirect mechanism of action. Further analysis revealed that hsa-miR-183 and hsa-miR-141 may target the transcription factor genes NFKB1 and STAT4, respectively, both of which positively correlate with IRF1 expression and are themselves associated with improved survival in ICI-treated patients. This study delineates a multi-layer miRNA regulatory network associated with IRF1 expression in NSCLC and identifies hsa-miR-301b, hsa-miR-183 and hsa-miR-141 as candidate upstream regulators of IRF1. Direct survival analysis for these miRNAs in ICI-treated cohorts was not feasible due to the lack of publicly available miRNA-seq data with treatment annotations; therefore, their clinical predictive value remains hypothetical, and experimental validation is required to assess their potential as predictors of ICI response.