Targeting the Myofibroblastic Cancer-Associated Fibroblast Phenotype Through Inhibition of NOX4

Abstract

BackgroundCancer-associated fibroblasts (CAFs) are tumor-promoting and correlate with poor survival in many cancers, which has led to their emergence as potential therapeutic targets. However, effective methods to manipulate these cells clinically have yet to be developed.MethodsCAF accumulation and prognostic significance in head and neck cancer (oral, n = 260; oropharyngeal, n = 271), and colorectal cancer (n = 56) was analyzed using immunohistochemistry. Mechanisms regulating fibroblast-to-myofibroblast transdifferentiation were investigated in vitro using RNA interference/pharmacological inhibitors followed by polymerase chain reaction (PCR), immunoblotting, immunofluorescence, and functional assays. RNA sequencing/bioinformatics and immunohistochemistry were used to analyze NAD(P)H Oxidase-4 (NOX4) expression in different human tumors. NOX4’s role in CAF-mediated tumor progression was assessed in vitro, using CAFs from multiple tissues in Transwell and organotypic culture assays, and in vivo, using xenograft (n = 9–15 per group) and isograft (n = 6 per group) tumor models. All statistical tests were two-sided.ResultsPatients with moderate/high levels of myofibroblastic-CAF had a statistically significant decrease in cancer-specific survival rates in each cancer type analyzed (hazard ratios [HRs] = 1.69–7.25, 95% confidence intervals [CIs] = 1.11 to 31.30, log-rank P ≤ .01). Fibroblast-to-myofibroblast transdifferentiation was dependent on a delayed phase of intracellular reactive oxygen species, generated by NOX4, across different anatomical sites and differentiation stimuli. A statistically significant upregulation of NOX4 expression was found in multiple human cancers (P < .001), strongly correlating with myofibroblastic-CAFs (r = 0.65–0.91, adjusted P < .001). Genetic/pharmacological inhibition of NOX4 was found to revert the myofibroblastic-CAF phenotype ex vivo (54.3% decrease in α-smooth muscle actin [α-SMA], 95% CI = 10.6% to 80.9%, P = .009), prevent myofibroblastic-CAF accumulation in vivo (53.2%–79.0% decrease in α-SMA across different models, P ≤ .02) and slow tumor growth (30.6%–64.0% decrease across different models, P ≤ .04).ConclusionsThese data suggest that pharmacological inhibition of NOX4 may have broad applicability for stromal targeting across cancer types.

Inhibition of PAI‐1 limits chemotherapy resistance in lung cancer through suppressing myofibroblast characteristics of cancer‐associated fibroblasts

“…4,5 Furthermore, a part of CAFs has myofibroblast (MF) characteristic with the expression of alpha-smooth muscle actin (α-SMA), which substantially promotes chemotherapeutic resistance by expressing high levels of inflammatory factors and chemokines. 6,7 Thus, the suppression of the MF characteristics of CAFs can be a novel treatment strategy for a chemotherapeutic-resistant lung cancer with myofibroblastic CAFs.…”

Modulation of the tumour promoting functions of cancer associated fibroblasts by phosphodiesterase type 5 inhibition increases the efficacy of chemotherapy in human preclinical models of esophageal adenocarcinoma

“…Stromal remodeling can promote cancer progression. CAFs display an activated myofibroblast phenotype and expression of αSMA in many solid tumors is a marker of reduced disease free and overall survival 8, 35, 39-41 . The tumor-promoting biology of CAFs make them a target for novel cancer therapies.…”

Pan-cancer deconvolution of cellular composition identifies molecular correlates of antitumour immunity and checkpoint blockade response

“…Finally, the lack of immune-resistance mutations in cold tumours (presumably due to the absence of a selection pressure for them) suggests that if we can induce lymphocyte infiltration (e.g. by targeting glycolysis or CAFs 84 ), we may improve the effectiveness of checkpoint blockade across a broader range of patients.…”