Differential roles of normal and lung cancer-associated fibroblasts in microvascular network formation.

Perfusable microvascular networks offer promising three-dimensional in vitro models to study normal and compromised vascular tissues as well as phenomena such as cancer cell metastasis. Engineering of these microvascular networks generally involves the use of endothelial cells stabilized by fibroblasts to generate robust and stable vasculature. However, fibroblasts are highly heterogenous and may contribute variably to the microvascular structure. Here, we study the effect of normal and cancer-associated lung fibroblasts on the formation and function of perfusable microvascular networks. We examine the influence of cancer-associated fibroblasts on microvascular networks when cultured in direct (juxtacrine) and indirect (paracrine) contacts with endothelial cells, discovering a generative inhibition of microvasculature in juxtacrine co-cultures and a functional inhibition in paracrine co-cultures. Furthermore, we probed the secreted factors differential between cancer-associated fibroblasts and normal human lung fibroblasts, identifying several cytokines putatively influencing the resulting microvasculature morphology and functionality. These findings suggest the potential contribution of cancer-associated fibroblasts in aberrant microvasculature associated with tumors and the plausible application of such in vitro platforms in identifying new therapeutic targets and/or agents that can prevent formation of aberrant vascular structures.

Symptomatic Pneumonitis With Durvalumab After Concurrent Chemoradiotherapy in Unresectable Stage III NSCLC.

Introduction: In the placebo-controlled, phase 3 PACIFIC trial, durvalumab significantly prolonged progression-free survival (PFS) (p < 0.0001) and overall survival (OS) (p = 0.00251) in patients with unresectable stage III NSCLC and no progression after platinum-based concurrent chemoradiotherapy (cCRT). Pneumonitis or radiation pneumonitis (PRP) was common in both arms. We report exploratory analyses evaluating the association of symptomatic (grade ≥2) PRP (G2+PRP) with baseline factors and clinical outcomes. Methods: Patients with WHO performance status of 0 or 1 were randomized (2:1) to 12 months of durvalumab or placebo, 1 to 42 days after cCRT. Associations between baseline factors and on-study G2+PRP in durvalumab-treated patients were investigated using univariate and multivariate logistic regression. PFS and OS were analyzed using Cox proportional hazards models adjusted for time-dependent G2+PRP plus covariates for randomization stratification factors without and with additional baseline factors. Results: On-study G2+PRP occurred in 94 of 475 (19.8%) and 33 of 234 patients (14.1%) on durvalumab and placebo, respectively (median follow-up, 25.2 mo); grade greater than or equal to 3 PRP was uncommon (4.6% and 4.7%, respectively). Time to onset and resolution of G2+PRP was similar with durvalumab and placebo. Univariate and multivariate analyses identified patients treated in Asia, those with stage IIIA disease, those with performance status of 1, and those who had not received induction chemotherapy as having a higher risk of G2+PRP. PFS and OS benefit favoring durvalumab versus placebo was maintained regardless of time-dependent G2+PRP. Conclusions: Factors associated with higher risk of G2+PRP with durvalumab after cCRT were identified. Clinical benefit was maintained regardless of on-study G2+PRP, suggesting the risk of this event should not deter the use of durvalumab in eligible patients with unresectable stage III NSCLC.

Differences in microenvironment of lung cancer and pleural effusions by single-cell RNA sequencing.

BACKGROUND: Direct comparison of tumor microenvironment of matched lung cancer biopsies and pleural effusions (PE) from the same patients is critical in understanding tumor biology but has not been performed. This is the first study to compare the lung cancer and PE microenvironment by single-cell RNA sequencing (scRNA-seq). METHODS: Matched lung cancer biopsies and PE were obtained prospectively from ten patients. We isolated CD45+ cells and performed scRNA-seq to compare the biopsies and PE. RESULTS: PE had a higher proportion of CD4+ T cells but lower proportion of CD8+ T cells (False detection rate, FDR = 0.0003) compared to biopsies. There was a higher proportion of naïve CD4+ T cells (FDR = 0.04) and naïve CD8+ T cells (FDR = 0.0008) in PE vs. biopsies. On the other hand, there was a higher proportion of Tregs (FDR = 0.04), effector CD8+ (FDR = 0.006), and exhausted CD8+ T cells (FDR = 0.01) in biopsies. The expression of inflammatory genes in T cells was increased in biopsies vs. PE, including TNF, IFN-É£, IL-1R1, IL-1R2, IL-2, IL-12RB2, IL-18R1, and IL-18RAP (FDR = 0.009, 0.013, 0.029, 0.043, 0.009, 0.013, 0.004, and 0.003, respectively). The gene expression of exhaustion markers in T cells was also increased in tumor biopsies including PDCD1, CTLA4, LAG 3, HAVCR2, TIGIT, and CD160 (FDR = 0.008, 0.003, 0.002, 0.011, 0.006, and 0.049, respectively). CONCLUSIONS: There is a higher proportion of naïve T cells and lower proportion of exhausted T cells and Tregs in PE compared to lung cancer biopsies, which can be leveraged for prognostic and therapeutic applications.