Immunotherapy in non-small-cell lung cancer: from targeted molecules to resistance patterns

Recent Developments and Challenges in Molecular-Targeted Therapy of Non-Small-Cell Lung Cancer

Treatment of lung cancer with conventional therapies, which include radiation, surgery, and chemotherapy results in multiple undesirable adverse or side effects. The major clinical challenge in developing new drug therapies for lung cancer is resistance, which involves mutations and disturbance in various signaling pathways. Molecular abnormalities related to epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B1 (B-RAF) Kirsten rat sarcoma virus (KRAS) mutations, translocation of the anaplastic lymphoma kinase (ALK) gene, mesenchymal-epithelial transition factor (MET) amplification have been studied to overcome the resistance and to develop new therapies for non-small cell lung cancer (NSCLC). But, inevitable development of resistance presents limits the clinical benefits of various new drugs. Here, we review current progress in the development of molecularly targeted therapies, concerning six clinical biomarkers: EGFR, ALK, MET, ROS-1, KRAS, and B-RAF for NSCLC treatment.

A comprehensive bioinformatics analysis of FOXP3 in nonsmall cell lung cancer

Fork head box p3 (FOXP3), the specific transcription factors of Tregs, not only in Tregs, but also expressed in cancer cells of certain malignant tumors. The histological positioning of FOXP3 in nonsmall cell lung cancer (NSCLC) and its biological significance are still unclear. This study aims to clarify the biological function of FOXP3 in NSCLC through bioinformatics analysis. Tumor immune estimation resource database was used to analyze the mRNA expression of FOXP3 in pan cancer, and to analyze the correlation between FOXP3 expression and tumor microenvironment cell infiltration. Overall survival and disease-free survival analyses were performed using a Kaplan-Meier plotter. Immunohistochemistry staining of FOXP3 was performed using human protein atalas (HPA) database, and immunofluorescence (IF) staining was used to verify gene expression and identify cell types. Protein-protein interaction (PPI) networks were drawn using STRING and visualized by Cytoscape. The functional and pathway enrichment analysis of FOXP3 used the DAVID database. In NSCLC, whether it is lung squamous cell carcinoma (P < .001) or lung adenocarcinoma (P < .001), FOXP3 is highly expressed in cancer tissue compared with normal tissue. Immunohistochemistry results showed that FOXP3 was mainly expressed in Tregs, but not in lung cancer tissues. IF staining showed that FOXP3 and CD3 (a marker of T cells) were co-expressed in immune cells. Moreover, survival analysis showed that high FOXP3 expression could be used as a predictor of poor overall survival (HR: 1.25, P = .00065) and disease-free survival (HR: 1.88, P = 1.1E-10) in patients with NSCLC. Next, we identified an important module containing 11 genes in the PPI network, including JUN, NFATC, STAT3, IRF4, IL2, IFGN, CTLA4, TNFRSF18, IL2A, KAT5, and FOXP3. KEGG signaling pathway was enriched in T cell receptor signaling pathway, Jak-STAT signaling pathway, cytokine-cytokine receptor interaction. Finally, we observed that FOXP3 expression correlated with infiltration of CD8 + T cells (R = 0.276, P = 5.90E-10), CD4 + T cells (R = 0.643, P = 6.81E-58), neutrophils (R = 0.525, P = 1.57E-35), and dendritic cells (R = 0.608, P = 1.35E-50) in lung adenocarcinoma, the same results were observed in lung squamous cell carcinoma. The infiltration of FOXP3-positive Tregs might promote the malignant progression of NSCLC, and targeted intervention of Tregs may be a potential treatment option for patients with NSCLC.

Higher TLR7 Gene Expression Predicts Poor Clinical Outcome in Advanced NSCLC Patients Treated with Immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of lung cancer. However, their clinical benefit is limited to a minority of patients. To unravel immune-related factors that are predictive of sensitivity or resistance to immunotherapy, we performed a gene expression analysis by RNA-Seq using the Oncomine Immuno Response Assay (OIRRA) on a total of 33 advanced NSCLC patients treated with ICI evaluating the expression levels of 365 immune-related genes. We found four genes (CD1C, HLA-DPA1, MMP2, and TLR7) downregulated (p < 0.05) and two genes (IFNB1 and MKI67) upregulated (p < 0.05) in ICI-Responders compared to ICI-Non-Responders. The Bayesian enrichment computational analysis showed a more complex interaction network that involved 10 other genes (IFNA1, TLR4, CD40, TLR2, IL12A, IL12B, TLR9, CD1E, IFNG, and HLA-DPB1) correlated with different functional groups. Five main pathways were identified (FDR < 0.0001). High TLR7 expression levels were significantly associated with a lack of response to immunotherapy (p < 0.0001) and worse outcome in terms of both PFS (p < 0.001) and OS (p = 0.03). The multivariate analysis confirmed TLR7 RNA expression as an independent predictor for both poor PFS (HR = 2.97, 95% CI, 1.16–7.6, p = 0.023) and OS (HR = 2.2, 95% CI, 1–5.08, p = 0.049). In conclusion, a high TLR7 gene expression level was identified as an independent predictor for poor clinical benefits from ICI. These data could have important implications for the development of novel single/combinatorial strategies TLR-mediated for an efficient selection of “individualized” treatments for NSCLC in the era of immunotherapy.

Lung Cancer Screening in a Surgical Lung Cancer Population: Analysis of a Rural, Quaternary, Academic Experience

BACKGROUND

Rural populations face many health disadvantages including higher rates of tobacco use and lung cancer than more populated areas. Given this, we specifically sought to understand the current screening landscape in a cohort of patients with resected lung cancer to help direct improvements in the screening process.

MATERIALS AND METHODS

We retrospectively reviewed our prospective database at a rural, quaternary, academic institution from January 2015 to June 2018. All patients who underwent resection for primary lung cancer were studied to assess the frequency of preoperative low-dose chest computed tomography per accepted guidelines. The intent was to evaluate participant demographics, clinical stage, frequency, and distribution of Lung-RADS reporting.

RESULTS

About 446 patients underwent primary resection, of which 252 were deemed screening-eligible. About 57 (22.6%) underwent low-dose chest computed tomography screening and 195 (77.4%) did not. No significant demographic differences were identified between groups. However, 82.5% (47/57) of the screened patients presented with clinical stage IA disease, compared with 67.1% (131/195) of the nonscreened patients (P = 0.03). Among those screened, 36.8% (21/57) did not have a Lung-RADS score documented despite 52.3% (11/21) of those coming from accredited programs.

CONCLUSIONS

Our screening completion rate was only 22.6% of eligible patients and 36.8% of those patients did not have a documented Lung-RADS score. These findings, in combination with the increased rate of diagnosis of stage IA disease, provide compelling reasons to further investigate factors designed to improve access and screening practices at rural institutions.

[Research Progress on the Mechanism and Clinical Data of Cereblon in Reversing the Resistance of Lung Cancer to PD-1 Antibody by T cells]

Programmed cell death receptor 1 (PD-1) is a membrance-spanning protein mostly expressed in the T cell, and combines with programmed cell death ligand 1 (PD-L1) in the targeting cell. When binding to the ligand on tumor cells, PD-1 as an immunosuppressive molecule, can inhibit the immune function of T cells, thus tumor immune escape. For example, depletion of peripheral effector T cell and accelerate the transformation of effector T cells into regulator T cells. To solve this problem, PD-1 antibody is used to bind to PD-1 on T cells to inhibit the interaction between PD-1 on the T cells and PD-L1 on the tumor cells so that it can restore the function of T cells to kill tumor cell. PD-1 antibodies, such as Nivolumab and Pembrolizumb, are approved as a first-line treatment for advanced non-small cell lung cell cancer. However, due to the interaction of tumor cells, T cells and cytokines, some patients developed drug resistance which reduces the efficacy of immunotherapy. Hence, how to overcome resistance has become a urgent problem. Cereblon (CRBN), a substrate receptor of the DDB1-cullin-RING E3 ubiquitin ligase complex and the only known molecular receptor of immunoregulatory drugs, has been found to reverse PD-1 antibody resistance by binding to CRBN regulatory agents (CMS), exert T cell immune function by regulating proliferation, activation and metabolism of T cell. In this paper, the mechanism of down-regulation of T cells leading to resistance of PD-1 antibody in lung cancer, the mechanism of CRBN regulating T cells, and research progress of CRBN regulator in the treatment of lung cancer were reviewed.
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How I Treat Non-Small Cell Lung Cancer Refractory to Immunotherapy

Lung cancer is a leading cause of cancer-related mortality despite continued advances in diagnostic and therapeutic strategies. Although the development of immune checkpoint inhibitors has revolutionized the treatment landscape for advanced non-small cell lung cancer, many patients either have primary resistance to these agents or eventually develop secondary resistance necessitating a change to an alternate therapy. Understanding novel patterns of response to immunotherapy is crucial in determining appropriate selection and sequencing of treatment. Chemotherapy remains the standard of care in immunotherapy-refractory disease, but multiple trials are ongoing to explore the role of combination radioimmunotherapy and rechallenging with immunotherapy either alone or in combination with other antineoplastic agents.