Ferroptosis is an intracellular iron-dependent form of cell death that is distinct from apoptosis, necrosis, and autophagy. Extensive studies suggest that ferroptosis plays a pivotal role in tumor suppression, thus providing new opportunities for cancer therapy. The development of resistance to cancer therapy remains a major challenge. A number of preclinical and clinical studies have focused on overcoming drug resistance. Intriguingly, ferroptosis has been correlated with cancer therapy resistance, and inducing ferroptosis has been demonstrated to reverse drug resistance. Herein, we provide a detailed description of the mechanisms of ferroptosis and the therapeutic role of regulating ferroptosis in reversing the resistance of cancer to common therapies, such as chemotherapy, targeted therapy and immunotherapy. We discuss the prospect and challenge of regulating ferroptosis as a therapeutic strategy for reversing cancer therapy resistance and expect that our review could provide some references for further studies.

Purpose: Our preclinical work suggests that appropriate angiogenesis inhibition could potentiate PD-1/PD-L1 blockade via alleviating hypoxia, increasing infiltration of CD8+ T cells and reducing recruitment of tumor-associated macrophages. We hereby conducted a clinical trial to evaluate this combination in pretreated patients with advanced non–small cell lung cancer (NSCLC). Patients and Methods: The study included phase Ib apatinib dose-escalation and phase II expansion cohorts. Patients received apatinib at doses of 250–500 mg orally once daily, in combination with camrelizumab 200 mg intravenously every 2 weeks. Results: From March 2017 to October 2018, 105 chemotherapy-pretreated patients with nonsquamous NSCLC were enrolled and received apatinib 250 mg (recommended phase II dose) and camrelizumab. Among them, one (1.0%) complete response, 28 (26.7%) partial responses, and 48 (45.7%) stable diseases were observed. In the efficacy-evaluable population (n = 94), objective response rate (ORR) was 30.9% [95% confidence interval (CI), 21.7–41.2]. The median progression-free survival was 5.7 months (95% CI, 4.5–8.8) and overall survival was 15.5 months (95% CI, 10.9–24.5). Efficacy of combination therapy was evident across all PD-L1 and tumor mutation burden subgroups, and appeared to be improved in patients with STK11/KEAP1 mutation (mutant vs. wild-type, ORR: 42.9% vs. 28.1%; 1-year survival rate: 85.1% vs. 53.1%). No unexpected adverse events were observed. Conclusions: Combined apatinib and camrelizumab showed encouraging antitumor activity and acceptable toxicity in chemotherapy-pretreated patients with advanced nonsquamous NSCLC. Patients with STK11/KEAP1 mutation might derive more benefits from this combination. We will validate these results in an ongoing phase III trial (NCT04203485).

Gefitinib, a tyrosine kinase inhibitor of epidermal growth factor receptor, has been used as the first choice of treatment for advanced non-small-cell lung cancer. However, during the course of treatment, cancer cells often develop resistance to gefitinib without fully understood mechanisms. In this study, we aimed to elucidate an important role of long intergenic non-coding RNA 00665 in developing resistance to gefitinib in non-small-cell lung cancer. We showed that long intergenic non-coding RNA 00665 expression was significantly upregulated in lung cancer tissues and cells with acquired gefitinib resistance. Long intergenic non-coding RNA 00665 knockdown restored gefitinib sensitivity both in vitro and in vivo by suppressing cell proliferation and inducing apoptosis. Moreover, knockdown of long intergenic non-coding RNA 00665 markedly reduced activation of EGFR and its downstream event protein kinase B (AKT). Moreover, LINC00665 could interact with EZH2 and regulate the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. Thus, our study suggests that long intergenic non-coding RNA 00665 is important for non-small-cell lung cancer to develop drug resistance and might be a potential biomarker for drug resistance and a therapeutic target for non-small-cell lung cancer.

Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment prolongs the survival of lung cancer patients harbouring activating EGFR mutations. However, resistance to EGFR-TKIs is inevitable after long-term treatment. Molecular mechanistic research is of great importance in combatting resistance. A comprehensive investigation of the molecular mechanisms underlying resistance has important implications for overcoming resistance. An accumulating body of evidence shows that lncRNAs can contribute to tumorigenesis and treatment resistance. By bioinformatics analysis, we found that LINC00969 expression was elevated in lung cancer cells with acquired gefitinib resistance. LINC00969 regulated resistance to gefitinib in vitro and in vivo. Mechanistically, gain of H3K4me1 and H3K27Ac led to the activation of LINC00969 expression. LINC00969 interacts with EZH2 and METTL3, transcriptionally regulates the level of H3K27me3 in the NLRP3 promoter region, and posttranscriptionally modifies the m6A level of NLRP3 in an m6A-YTHDF2-dependent manner, thus epigenetically repressing NLRP3 expression to suppress the activation of the NLRP3/caspase-1/GSDMD-related classical pyroptosis signalling pathways, thereby endowing an antipyroptotic phenotype and promoting TKI resistance in lung cancer. Our findings provide a new mechanism for lncRNA-mediated TKI resistance from the new perspective of pyroptosis via simultaneous regulation of histone methylation and RNA methylation. The pivotal role of LINC00969 gives it the potential to be a novel biomarker and therapeutic target for overcoming EGFR-TKI resistance in lung cancer.

Background: Invasive adenocarcinoma (IAC), which is typically preceded by minimally invasive adenocarcinoma (MIA), is the dominant pathological subtype of early-stage lung adenocarcinoma (LUAD). Identifying the molecular events underlying the progression from MIA to IAC may provide a crucial perspective and boost the exploration of novel strategies for early-stage LUAD diagnosis and treatment. Methods: Transcriptome sequencing of four pairs of MIA and IAC tumours obtained from four multiple primary lung cancer patients was performed to screen out beta-1,4-galactosyltransferase1 (B4GALT1). Function and mechanism experiments in vitro and in vivo were performed to explore the regulatory mechanism of B4GALT1-mediated immune evasion by regulating programmed cell death ligand 1 (PD-L1). Results: B4GALT1, a key gene involved in N-glycan biosynthesis, was highly expressed in IAC samples. Further experiments revealed that B4GALT1 regulated LUAD cell proliferation and invasion both in vitro and in vivo and was related to the impaired antitumour capacity of CD8 + T cells. Mechanistically, B4GALT1 directly mediates the N-linked glycosylation of PD-L1 protein, thus preventing PD-L1 degradation at the posttranscriptional level. In addition, B4GALT1 stabilized the TAZ protein via glycosylation, which activated CD274 at the transcriptional level. These factors lead to lung cancer immune escape. Importantly, inhibition of B4GALT1 increased CD8 + T-cell abundance and activity and enhanced the antitumour immunity of anti-PD-1 therapy in vivo. Conclusion: B4GALT1 is a critical molecule in the development of early-stage LUAD and may be a novel target for LUAD intervention and immunotherapy.

Long non-coding RNA LUCAT1 is associated with poor prognosis in human non-small cell lung cancer and regulates cell proliferation via epigenetically repressing p21 and p57 expression Long non-coding RNA LUCAT1 is associated with poor prognosis in human non-small lung cancer and regulates cell proliferation via epigenetically repressing p21 and p57 expression