ABSTRACT
INTRODUCTION: Recent insights regarding mechanisms mediating stemness, heterogeneity, and metastatic potential of lung cancers have yet to be fully translated to effective regimens for the treatment of these malignancies. This study sought to identify novel targets for lung cancer therapy. METHODS: Transcriptomes and DNA methylomes of 14 SCLC and 10 NSCLC lines were compared with normal human small airway epithelial cells (SAECs) and induced pluripotent stem cell (iPSC) clones derived from SAEC. SCLC lines, lung iPSC (Lu-iPSC), and SAEC were further evaluated by DNase I hypersensitive site sequencing (DHS-seq). Changes in chromatin accessibility and depths of transcription factor (TF) footprints were quantified using Bivariate analysis of Genomic Footprint. Standard techniques were used to evaluate growth, tumorigenicity, and changes in transcriptomes and glucose metabolism of SCLC cells after NFIC knockdown and to evaluate NFIC expression in SCLC cells after exposure to BET inhibitors. RESULTS: Considerable commonality of transcriptomes and DNA methylomes was observed between Lu-iPSC and SCLC; however, this analysis was uninformative regarding pathways unique to lung cancer. Linking results of DHS-seq to RNA sequencing enabled identification of networks not previously associated with SCLC. When combined with footprint depth, NFIC, a transcription factor not previously associated with SCLC, had the highest score of occupancy at open chromatin sites. Knockdown of NFIC impaired glucose metabolism, decreased stemness, and inhibited growth of SCLC cells in vitro and in vivo. ChIP-seq analysis identified numerous sites occupied by BRD4 in the NFIC promoter region. Knockdown of BRD4 or treatment with Bromodomain and extra-terminal domain (BET) inhibitors (BETis) markedly reduced NFIC expression in SCLC cells and SCLC PDX models. Approximately 8% of genes down-regulated by BETi treatment were repressed by NFIC knockdown in SCLC, whereas 34% of genes repressed after NFIC knockdown were also down-regulated in SCLC cells after BETi treatment. CONCLUSIONS: NFIC is a key TF and possible mediator of transcriptional regulation by BET family proteins in SCLC. Our findings highlight the potential of genome-wide chromatin accessibility analysis for elucidating mechanisms of pulmonary carcinogenesis and identifying novel targets for lung cancer therapy.
ABSTRACT
BACKGROUND: Adrenocortical carcinoma (ACC) commonly metastasizes to the lungs, and pulmonary metastasectomy (PM) is utilized due to limited systemic options. METHODS: All ACC patients with initially only lung metastases (LM) from a single institution constituted this observational case series. Kaplan-Meier and Cox proportional hazard analyses evaluated the association with potential prognostic factors and outcomes. Overall survival (OS) was calculated from the date of the PM or, in those patients who did not undergo surgery, from the development of LM. RESULTS: A total of 75 ACC patients over a 45-year period met the criteria; 52 underwent PM, and 23 did not. The patients undergoing PM had a median OS of 3.1 years (95% CI: 2.4, 4.7 years) with the 5- and 10-year OS being 35.5% and 32.8%, respectively. The total resected LM did not impact the OS nor the DFS. The patients who developed LM after 11 months from the initial ACC resection had an improved OS (4.2 years; 95% CI: 3.2, NR; p = 0.0096) compared to those developing metastases earlier (2.4 years; 95% CI: 1.6, 2.8). Patients who underwent PM within 11 months of adrenalectomy demonstrated a reduced OS (2.2 years; 95% CI: 1.0, 2.7) compared to those after 11 months (3.6 years, 95% CI: 2.6, NR; p = 0.0045). PM may provide benefit to those patients with LM at presentation (HR: 0.5; p = 0.2827), with the time to first PM as a time-varying covariate. CONCLUSIONS: PM appears to have a role in ACC patients. The number of nodules should not be an exclusion factor. Patients developing LM within a year of primary tumor resection may benefit from waiting before further surgeries, which may provide additional insight into who may benefit from PM.
ABSTRACT
OBJECTIVE: Increasing forces threaten the viability of thoracic surgeon-initiated research, a core component of our academic mission. National Institutes of Health funding is a benchmark of research productivity and innovation. This study examined the current status of National Institutes of Health funding for thoracic surgeons. METHODS: Thoracic surgeon principal investigators on National Institutes of Health-funded grants during June 2010, June 2015, and June 2020 were identified using National Institutes of Health iSearchGrants (version 2.4). American Association of Medical Colleges data were used to identify all surgeons in the United States. Types and total costs of National Institutes of Health-funded grants were compared relative to other surgical specialties. RESULTS: A total of 61 of 4681 (1.3%), 63 of 4484 (1.4%), and 60 of 4497 (1.3%) thoracic surgeons were principal investigators on 79, 76, and 87 National Institutes of Health-funded grants in 2010, 2015, and 2020, respectively; these rates were higher than those for most other surgical specialties (P ≤ .0001). Total National Institutes of Health costs for Thoracic Surgeon-initiated grants increased 57% from 2010 to 2020, outpacing the 33% increase in total National Institutes of Health budget. Numbers and types of grants varied among cardiovascular, transplant, and oncology subgroups. Although the majority of grants and costs were cardiovascular related, increased National Institutes of Health expenditures primarily were due to funding for transplant and oncology grants. Per-capita costs were highest for transplant-related grants during both years. Percentages of R01-to-total costs were constant at 55%. Rates and levels of funding for female versus male thoracic surgeons were comparable. Awards to 5 surgeons accounted for 33% of National Institutes of Health costs for thoracic surgeon principal investigators in 2020; a similar phenomenon was observed for 2010 and 2015. CONCLUSIONS: Long-term structural changes must be implemented to more effectively nurture the next generation of thoracic surgeon scientists.
