Although several lines of evidence have established the central role of epithelial-to-mesenchymal-transition (EMT) in malignant progression of non-small cell lung cancers (NSCLCs), the molecular events connecting EMT to malignancy remain poorly understood. This study presents evidence that Long Interspersed Nuclear Element-1 (LINE-1) retrotransposon couples EMT programming with malignancy in human bronchial epithelial cells (BEAS-2B). This conclusion is supported by studies showing that: 1) activation of EMT programming by TGF-β1 increases LINE-1 mRNAs and protein; 2) the lung carcinogen benzo(a)pyrene coregulates TGF-β1 and LINE-1 mRNAs, with LINE-1 positioned downstream of TGF-β1 signaling; and, 3) forced expression of LINE-1 in BEAS-2B cells recapitulates EMT programming and induces malignant phenotypes and tumorigenesis in vivo. These findings identify a TGFβ1-LINE-1 axis as a critical effector pathway that can be targeted for the development of precision therapies during malignant progression of intractable NSCLCs.

Introduction: Curative intent treatment of stage III NSCLC is variable and influenced by both patient and disease characteristics. We performed a real-world analysis of curative therapies in stage III NSCLC, and explored the impact of known prognostic factors on outcome. Methods: A retrospective review was completed of all patients with stage III NSCLC between January 2005 and December 2012. Cases were filtered to identify those receiving curative intent therapy including surgery, radiotherapy (RT), chemoradiotherapy (CRT), and combined modality with surgery (S þ RT). Information was collected on known prognostic and predictive factors, and immunotherapy eligibility per the PACIFIC trial. The primary outcome measure was overall survival. Results: A total of 638 patients with stage III NSCLC were referred and received curative intent treatment. Of these, 66 (10%) received surgery, 95 (15%) RT, 410 (64%) CRT, and 67 (11%) combined S þ RT. Median overall survival (OS) was similar for surgery (28.6 mo) and CRT (27.0 mo), inferior for RT alone (17.5 mo), and superior for S þ RT (55.8 mo). In a multivariate model only, Eastern Cooperative Oncology Group performance status (ECOG PS) and treatment cohort significantly influenced OS. In a case-matched analysis, the median OS for CRT was 31.9 months, compared to 55.8 months with trimodality treatment. Overall, 61% of patients receiving CRT and 88% of those receiving trimodality therapy would have been potentially eligible for adjuvant immunotherapy. Conclusions: In stage III NSCLC, the performance of surgery and CRT are similar after controlling for known prognostic factors. Radiotherapy alone is associated with worse outcomes. Combined S þ RT appears to provide a significant benefit above other modalities, albeit in highly selected patients.

Objectives: Metastatic non–small cell lung cancer (NSCLC) has a poor prognosis. Most patients present with stage IV, and many patients treated curatively with stage I to III develop recurrent metastatic disease. It is unknown whether the natural history differs between patients with recurrent versus de novo metastatic NSCLC. We hypothesized that de novo metastatic status is associated with decreased overall survival compared with recurrent metastatic disease. Materials and Methods: A retrospective review was completed of all patients with NSCLC referred to BC Cancer from 2005 to 2012. Two cohorts were created; de novo metastatic disease and patients treated with curative intent (surgery or radiotherapy) that developed recurrent, metastatic disease. Information was collected on known prognostic and predictive factors. Overall survival was calculated from the date of diagnosis of metastatic disease. Results: A total of 9651 patients were evaluated, 5782 (60%) with de novo stage IV disease, and 3869 (40%) with stage I to III disease. Of the 1658 patients who received curative therapy for stage I to III disease, 757 (46%) developed metastases. Patients in the de novo cohort versus recurrent cohort were more likely male (52% vs. 48%), have poorer performance status (Eastern Cooperative Oncology Group≥2 50% vs. 44%), and receive no palliative systemic therapy (67% vs. 61%). The median overall survival in the de novo cohort was 4.7 versus 6.9 m in the recurrent cohort (P<0.001). De novo status was associated with shorter overall survival and this remained significant in a multivariate model that incorporated known prognostic factors. Conclusions: In a large population-based study of NSCLC, de novo metastatic status was independently associated with decreased overall survival from the time of metastatic disease diagnosis.

The evolution of diagnosis and treatment of advanced nonsmall‐cell lung cancer (NSCLC) has led to increasing the use of targeted therapy and immune checkpoint inhibitors. The study goal was to assess the effect of molecular testing and the introduction of new therapies on overall survival (OS). All patients with stage IV NSCLC referred to BC Cancer were included in the study. Four 1‐year time cohorts were created based on molecular testing implementation and funded drug availability: C1 baseline (2009), C2 EGFR TKI access (2011), C3 ALK inhibitor access (2015), C4 immunotherapy availability (2017). Baseline demographics, disease characteristics, and systemic therapy details were collected retrospectively. OS was calculated using the Kaplan–Meier method and compared using the log‐rank test. There were 3421 patients identified with stage IV NSCLC and 1319 (39%) received systemic therapy. In the four 1‐year time cohorts C1/C2/C3/C4: driver mutation‐targeted treatment increased 1/17/27/34% (of total systemic therapy), as did treatment with any line immunotherapy <1/1/9/38%. Median OS with best supportive care (BSC) was 3.4/3.1/3.2/2.9 m (p = 0.16) and with systemic treatment 9.9/10.9/13.9/15.0 m (p < 0.001). Median OS by treatment exposure was BSC 3.1 m, chemotherapy only 7.3 m, targeted therapy 17.5 m, and immunotherapy 20.7 m. In our real‐world study, following the introduction of targeted therapy and immune checkpoint inhibitors, there was a significant improvement in OS in each successive time cohort concordant with advancements in therapeutic options.

Lung cancer is the most common cause of cancer death in the United States. The genome of nonsmall cell lung cancer (NSCLC), the most frequent lung cancer type, is strongly affected by Long Interspersed Nuclear Element (LINE1) insertions. Active LINE1s are repetitive DNA sequences that can amplify themselves in the genome utilizing a retrotransposition mechanism whereby LINE1 is copied via reverse transcription and inserted at target sites. ORF1p and ORF2p are LINE1 encoded proteins essential for LINE1 retrotransposition. LINE1s are silenced epigenetically in somatic tissues, and their reactivation has been associated with cancer pathogenesis. Here, we present evidence that nucleolin (NCL) regulates expression of LINE1-ORF1p (L1-ORF1p) in NSCLC cells. Genetic knockdown of NCL significantly inhibited expression of L1-ORF1p in various NSCLC cell lines. Treatment with the investigational NCL antagonist N6L ablated L1-ORF1p expression in all cell lines constitutively expressing L1-ORFp. N6L displayed a stronger antiproliferative activity in NSCLC tumor cell lines expressing the highest L1-ORF1p protein levels. Moreover, N6L treatment of nude mice bearing NSCLC tumor xenografts blocked L1-ORF1p expression and effectively inhibited tumor growth. These data indicate that L1-ORF1p expression is regulated by NCL and identify NCL as a novel promising target for pharmacological inhibition of LINE1.