Pemetrexed induces ROS generation and cellular senescence by attenuating TS-mediated thymidylate metabolism to reverse gefitinib resistance in NSCLC.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) are strongly recommended for non-small-cell lung cancer (NSCLC) patients harbouring active EGFR mutations, while drug resistance makes exploring resistance mechanisms and seeking effective therapeutic strategies urgent endeavours. Thymidylate synthetase (TYMS or TS) is a dominant enzyme in thymidylate nucleotide metabolism. In this study, we found a positive correlation between TS expression and overall survival (OS) and disease-free survival (DFS) in lung adenocarcinoma. The examination of gene sets from 140 NSCLC patients received EGFR-TKI therapy demonstrated a negative correlation between high TS expression and the efficacy of EGFR-TKI therapy. 24 tissue specimens from NSCLC patients exhibited upregulated TS mRNA expression in NSCLC patients resistant to gefitinib. The NSCLC cell PC9 and HCC827 sensitive to gefitinib and relatively resistant PC9/GR and HCC827/GR cells were used to demonstrate the knockdown of TS restored the sensitivity of resistant cells to gefitinib. Furthermore, pemetrexed effectively suppressed TS-mediated thymidylate metabolism and induced ROS generation, DNA damage and cellular senescence, thereby hampering cancer progression and restoring sensitivity to gefitinib. Our findings illuminate the potential mechanism of TS-triggered gefitinib resistance and indicate inhibition of TS by pemetrexed can potentiate the effect of gefitinib in NSCLC. Pemetrexed combined with gefitinib has potent anti-progression potential in gefitinib-resistant NSCLC. This study suggests that NSCLC patients with both high TS expression and EGFR-driving mutations might benefit more from a combination strategy of EGFR-TKI and pemetrexed-based chemotherapy than EGFR-TKI monotherapy, which has profound clinical implications and therapeutic value.

Efficacy and safety of antiangiogenic agents or chemotherapy plus EGFR-TKIs in advanced non-small cell lung cancer: A systematic review and network meta-analysis.

BACKGROUND: The combination of antiangiogenic agents with epidermal growth factor receptor inhibitors (EGFR-TKIs) and chemotherapy with EGFR-TKIs are the most common combination treatment options in epidermal growth factor receptor (EGFR) positive non-small cell lung cancer (NSCLC). This network meta-analysis was performed to evaluate the differences between them. METHODS: We searched the PubMed, EMBASE and the Cochrane Controlled Trials Register up to August 2022. The primary outcomes were progression-free survival (PFS) and objective response rate (ORR). The secondary endpoints were overall survival (OS), disease control rate (DCR) and adverse events (AEs). The data of hazard ratio (HR) or risk ratio (RR) with their corresponding 95% confidence intervals (CIs) were extracted in the studies. A network meta-analysis (NMA) was used to indirectly compare the efficacy and safety of antiangiogenic agents plus EGFR-TKIs and chemotherapy plus EGFR-TKIs. RESULTS: Pooled data of included studies were demonstrated that chemotherapy plus EGFR-TKIs had a benefit in ORR compared to antiangiogenic agents plus EGFR-TKIs in patients with EGFR mutated NSCLC (RR = 1.1, 95% CI: 1.0-1.2). However, there were no significant differences in PFS, OS and DCR between in the two group (PFS: HR = 1.0, 95% CI: 0.74-1.6; OS: HR = 0.78, 95% CI: 0.45-1.5; DCR: RR = 1.0, 95% CI: 0.94-1.1). The common treatment-related AEs in the two groups were relatively manageable. CONCLUSION: Based on the efficacy and safety, the combination of chemotherapy with EGFR-TKIs is considered the best combination treatment options in advanced NSCLC with EGFR mutation.

Rechallenge of immune checkpoint inhibitors in a case with adverse events inducing myasthenia gravis.

The mechanism(s) of immune checkpoint inhibitor (ICI)-induced myasthenia gravis (MG), an immune-related adverse event (irAE) that is fatal and limits subsequent ICI use, remain unexplored. Here, through comparative genomic analysis, we identified a pathogenic p.S467C germline variant in SLC22A5 in a thymoma case with ICI-induced MG, which was found to be associated with fatty acid oxidation through its regulation on L-carnitine levels. Remarkably, ICI rechallenge with L-carnitine pretreatment led to durable response without MG-related symptoms. Thus, we provide the first clinical evidence of genetic test-directed irAE management, which integrates individualized ICI treatment into the evolving paradigm of cancer management.

Ferroptosis in cancer therapy: a novel approach to reversing drug resistance.

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.

The miRNA125a-5p and miRNA125b-1-5p cluster induces cell invasion by down-regulating DDB2-reduced epithelial-to-mesenchymal transition (EMT) in colorectal cancer.

Background: MicroRNA (miRNA) is a kind of non-coding RNA that regulates gene expression and is involved in tumor development. MiRNA-125 is reportedly aberrantly expressed in colorectal cancer tissue; however, its potential function and underlying mechanism remain unclear. The present study aimed to investigate the expression level and potential role of the miRNA-125 family in the invasion and migration of colorectal cancer. Methods: To further understand the role of the miRNA-125 family in metastatic colorectal cancer, we overexpressed miRNA-125 in the SW480 cell line by transfection with the miRNA-125 family mimics or a sponge. Methyl thiazolyl tetrazolium (MTT) assay was performed to identify the effect of the miRNA-125 family on cell proliferation, and a Transwell filter assay was used to detect the role of the miRNA-125 family in migration and invasion. A luciferase assay was carried out to confirm the binding site of miRNA-125 and the target gene, damage specific DNA binding protein 2 (DDB2). Western blot was applied to detect the expression levels of DDB2 and the markers of epithelial-to-mesenchymal transition (EMT) in colorectal cancer cells. Results: The real-time polymerase chain reaction (PCR) results showed that miR-125a-5p and miR-125b-1-5p were up-regulated in metastatic colorectal cancer tissues. The Transwell filter assay results appeared that miR-125a-5p and miR-125b-1-5p could promote the invasion and migration of colorectal cancer cells. The luciferase assay data confirmed the binding site of miR-125a-5p and miR-125b-1-5p on the 3' untranslated region (3'UTR) of DDB2 messenger RNA (mRNA). The real-time PCR and Western blot results indicated that miR-125a-5p and miR-125b-1-5p could regulate the expression levels of DDB2 and EMT markers, and lower DDB2 expression was observed in metastatic tissues. Conclusions: Our findings illustrated that miRNA125a-5p and miRNA125b-1-5p could reduce the expression of DDB2 by binding to the 3'UTR region, and then regulate the expression levels of EMT markers, leading to the enhanced invasion and metastasis of colorectal cancer cells. Thus, miRNA125a-5p and miRNA125b-1-5p might be novel markers of colorectal cancer migration and potential therapeutic targets to treat metastatic colorectal cancer patients.

Concurrent use of anlotinib overcomes acquired resistance to EGFR-TKI in patients with advanced EGFR-mutant non-small cell lung cancer.

BACKGROUND: Acquired resistance development is a major challenge in the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC). Here, we investigated the potential effects of the concurrent use of anlotinib and EGFR-TKI to overcome acquired resistance. METHODS: We conducted a preclinical study to evaluate the antitumor effects of gefitinib + anlotinib in gefitinib-resistant lung adenocarcinoma models in vitro and in vivo. We then investigated the treatment effect of EGFR-TKI + anlotinib therapy in 24 advanced EGFR-mutant NSCLC patients after EGFR-TKI acquired resistance between January 2018 and August 2020. RESULTS: Anlotinib reversed gefitinib resistance in gefitinib-resistant lung adenocarcinoma models by enhancing the antiproliferative and proapoptotic effects of gefitinib. The gefitinib + anlotinib treatment exerted a synergistic antitumor effect by downregulating the activation of VEGFR2 and downstream effectors, Akt and ERK. The EGFR-TKI + anlotinib therapy exhibited an objective response rate of 20.8% and a disease control rate of 95.8%. Median progression-free survival (PFS) was 11.53 ± 2.41 months, but median overall survival was not reached. The median PFS was longer in patients experiencing gradual progression (13.30 ± 1.69 months) than in patients with dramatic progression (6.80 ± 1.75 months, p = 0.017). One grade 3 adverse event was noted (diarrhea, n = 2, 8.3%), and grade 4 or 5 adverse events were absent. CONCLUSIONS: EGFR-TKI combined with anlotinib demonstrated powerful antitumor activity in vitro and in vivo. Concurrent use of anlotinib overcomes acquired resistance to EGFR-TKI in advanced EGFR-mutant NSCLC patients.

Efficacy and acquired resistance of EGFR-TKI combined with chemotherapy as first-line treatment for Chinese patients with advanced non-small cell lung cancer in a real-world setting.

BACKGROUND: To compare the benefits and explore the cause of acquired resistance of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and its combination with chemotherapy in advanced non-small-cell lung cancer (NSCLC) patients harboring EGFR mutation in a real-life setting. METHODS: This retrospective analysis included 117 advanced NSCLC patients with EGFR mutation who underwent next-generation sequencing (NGS) prior to treatment. The combination group included 50 patients who received the regimen of EGFR-TKI combined with chemotherapy, while the EGFR-TKI monotherapy group included 67 patients treated with TKI only. The primary endpoint of this study was progression-free survival (PFS); the secondary endpoints were overall survival (OS), response rate, and toxicity. RESULTS: The median PFS was significantly longer in the combination group than in the EGFR-TKI monotherapy group (19.00 months [95% CI, 14.67-23.33] vs. 11.70 months [95% CI, 10.81-12.59], p < 0.001). Subgroup analysis showed a similar trend of results. The median OS was not reached in the combination group and was 38.50 (95% CI, 35.30-41.70) months in the EGFR-TKI monotherapy group (p = 0.586). Patients in the combination group were more likely to experience adverse events, most of which showed the severity of grade 1 or 2. T790M mutation remains the main reason for acquired resistance, and the frequency of T790M mutation was similar between the two groups (p = 0.898). CONCLUSIONS: Compared with EGFR-TKI monotherapy, EGFR-TKI combined with chemotherapy significantly improved PFS in advanced NSCLC patients with EGFR mutation, with acceptable toxicity.

The development and validation of a nomogram for predicting brain metastases in lung squamous cell carcinoma patients: an analysis of the Surveillance, Epidemiology, and End Results (SEER) database.

BACKGROUND: The incidence of brain metastasis (BM) in patients suffering from lung squamous cell carcinoma (LUSC) is lower than that in patients suffering from non-squamous cell carcinoma (NSCC) and there are few studies on BM of LUSC. The purpose of this investigation was to ascertain the risk factors of LUSC, as well as to establish a nomogram prognostic model to predict the incidence of BM in patients with LUSC. METHODS: Patients diagnosed with LUSC between 2010 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database and the patient data were collated. All patients diagnosed from 2010-2012 were allocated into the training cohort, and the remaining patients diagnosed from 2013-2015 formed the test cohort. Using factors that were screened out through logistic regression analyses, the nomogram in the training cohort was established. It was then evaluated for discrimination and calibration using the test cohort. The performance of the nomogram was assessed by quantifying the area under the receiver operating characteristic (ROC) curve and evaluating the calibration curve. RESULTS: A total of 26,154 LUSC patients were included in the study. The training cohort consisted of 16,543 patients and there were 8611 patients in the test cohort. Age, marital status, insurance status, histological grade, tumor location, laterality, stage of the cancer, number of metastatic organs, chemotherapy, surgery, and radiotherapy were highly correlated with the incidence of BM. The area under the ROC curve (AUC) of the nomogram for the training cohort and the test cohort were 0.810 [95% confidence interval (CI): 0.796 to 0.823] and 0.805 (95% CI: 0.784 to 0.825), respectively. The slope of the calibration curve was close to 1. CONCLUSIONS: The nomogram was able to accurately predict the incidence of BM. This may be beneficial for the early identification of high-risk LUSC patients and the establishment of individualized treatments.

Checkpoint inhibitor pneumonitis in Chinese lung cancer patients: clinical characteristics and risk factors.

BACKGROUND: Checkpoint inhibitor pneumonitis (CIP) may be accompanied by lung cancer in patients treated with immune checkpoint inhibitors (ICI). This study aimed to test the risk factors, genetic and clinical characteristics of CIP in a cohort of Chinese patients with lung cancer. METHODS: We retrospectively reviewed the medical records of eligible patients who received ICI treatment from December 2017 to September 2020 in our hospital. Patient characteristics, ICI protocols, and mutation frequencies of related genes are compared between the CIP group and the non-CIP group. RESULTS: A total of 94 patients were recruited. Of them, 16 (17.0%) patients developed CIP. Multivariate logistic regression analysis suggested Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2 [odds ratio (OR) =6.53; 95% confidence interval (CI), 1.74-24.46; P=0.005] and previous pulmonary fibrosis (OR =20.13; 95% CI, 3.64-111.44; P=0.001) were independently associated with a higher incidence of CIP. There was an increasing trend, although not statistically significant, in the risk of CIP in patients with TP53 mutation (P=0.280). Most CIP patients were managed successfully following the current guideline. However, serious events (including one death) were still observed. CONCLUSIONS: ECOG PS ≥2 and earlier pulmonary fibrosis were closely correlated to the occurrence of CIP in Chinese lung cancer patients after ICI treatment. Early screening and prompt intervention are necessary for the management of CIP.

A multicenter real-world study of tumor-derived DNA from pleural effusion supernatant in genomic profiling of advanced lung cancer.

BACKGROUND: Pleural effusion (PE) is commonly observed in advanced lung cancer. Research has suggested that molecular profiling of PE could be used to detect tumor driver mutations, thus informing clinical decision-making. However, the performance of PE samples in a real-world setting has yet to be examined. METHODS: A total of 678 metastatic lung cancer patients with pleural effusion were enrolled in this study. Cohort 1 included 22 patients whose PE and matched plasma samples were simultaneously collected as a pilot study. Cohort 2 comprised 656 patients, from whom 734 samples were collected in a real world setting. These samples were subjected to targeted next-generation sequencing (NGS) of 1,021 cancer-related genes. RESULTS: PE supernatant was the preferred choice for genetic profiling. While the maximal somatic allele frequency (MSAF) of plasma in patients with M1a stage was significantly lower than that in patients with M1b/c stages (4.4%±9.6% vs. 9.0%±14.1%, P<0.01), the MSAF of PE supernatant was similar between M1a and M1b/c stages. PE supernatant demonstrated higher sensitivity than plasma in detecting actionable mutations in cohort 1 (81.8% vs. 45.5%, P=0.01) as well as in M1a disease (84.7% vs. 42.1%, P<0.01), but not in M1b/c disease, in cohort 2. Known resistant mutations were identified in 72 of the 117 patients who were resistant to first- or second-generation EGFR-TKIs, 22 of the 42 patients who were resistant to osimertinib, and 9 of the 13 patients who were resistant to crizotinib. Remarkably, PE supernatant outperformed plasma in identifying mutations that confer resistance to first- and second-generation EGFR-TKIs (75.4% vs. 29.8%, P<0.001). CONCLUSIONS: This real-world large cohort study verified that PE supernatant had higher sensitivity than plasma for identifying actionable mutations, including resistance mutations. PE supernatant would be preferred by physicians for assessing tumor genomics in advanced lung cancer when tumor tissue is not available.