A vascularized breast cancer spheroid platform for the ranked evaluation of tumor microenvironment-targeted drugs by light sheet fluorescence microscopy

Targeting the supportive tumor microenvironment (TME) is an approach of high interest in cancer drug development. However, assessing TME-targeted drug candidates presents a unique set of challenges. We develop a comprehensive screening platform that allows monitoring, quantifying, and ranking drug-induced effects in self-organizing, vascularized tumor spheroids (VTSs). The confrontation of four human-derived cell populations makes it possible to recreate and study complex changes in TME composition and cell-cell interaction. The platform is modular and adaptable for tumor entity or genetic manipulation. Treatment effects are recorded by light sheet fluorescence microscopy and translated by an advanced image analysis routine in processable multi-parametric datasets. The system proved to be robust, with strong interassay reliability. We demonstrate the platform's utility for evaluating TME-targeted antifibrotic and antiangiogenic drugs side-by-side. The platform's output enabled the differential evaluation of even closely related drug candidates according to projected therapeutic needs.

Prognostic Impact of the Immune-Cell Infiltrate in N1-Positive Non-Small-Cell Lung Cancer

INTRODUCTION

The tumoral immune milieu plays a crucial role for the development of non-small-cell lung cancer (NSCLC) and may influence individual prognosis. We analyzed the predictive role of immune cell infiltrates after curative lung cancer surgery.

MATERIALS AND METHODS

The tumoral immune-cell infiltrate from 174 patients with pN1 NSCLC and adjuvant chemotherapy was characterized using immunofluorescence staining. The density and distribution of specific immune cells in tumor center (TU), invasive front (IF) and normal tissue (NORM) were correlated with clinical parameters and survival data.

RESULTS

Tumor specific survival (TSS) of all patients was 69.9% at 5 years. The density of tumor infiltrating lymphocytes (TIL) was higher in TU and IF than in NORM. High TIL density in TU (low vs. high: 62.0% vs. 86.7%; p = .011) and the presence of cytotoxic T-Lymphocytes (CTLs) in TU and IF were associated with improved TSS (positive vs. negative: 90.6% vs. 64.7% p = .024). High TIL-density correlated with programmed death-ligand 1 expression levels ≥50% (p < .001). Multivariate analysis identified accumulation of TIL (p = .016) and low Treg density (p = .003) in TU as negative prognostic predictors in squamous cell carcinoma (p = .025), whereas M1-like tumor- associated macrophages (p = .019) and high programmed death-ligand 1 status (p = .038) were associated with better survival in adenocarcinoma.

CONCLUSION

The assessment of specific intratumoral immune cells may serve as a prognostic predictor in pN1 NSCLC. However differences were observed related to adenocarcinoma or squamous cell carcinoma histology. Prospective assessment of the immune-cell infiltrate and further clarification of its prognostic relevance could assist patient selection for upcoming perioperative immunotherapies.

Image-based modeling of vascular organization to evaluate anti-angiogenic therapy

In tumor therapy anti-angiogenic approaches have the potential to increase the efficacy of a wide variety of subsequently or co-administered agents, possibly by improving or normalizing the defective tumor vasculature. Successful implementation of the concept of vascular normalization under anti-angiogenic therapy, however, mandates a detailed understanding of key characteristics and a respective scoring metric that defines an improved vasculature and thus a successful attempt. Here, we show that beyond commonly used parameters such as vessel patency and maturation, anti-angiogenic approaches largely benefit if the complex vascular network with its vessel interconnections is both qualitatively and quantitatively assessed. To gain such deeper insight the organization of vascular networks, we introduce a multi-parametric evaluation of high-resolution angiographic images based on light-sheet fluorescence microscopy images of tumors. We first could pinpoint key correlations between vessel length, straightness and diameter to describe the regular, functional and organized structure observed under physiological conditions. We found that vascular networks from experimental tumors diverted from those in healthy organs, demonstrating the dysfunctionality of the tumor vasculature not only on the level of the individual vessel but also in terms of inadequate organization into larger structures. These parameters proofed effective in scoring the degree of disorganization in different tumor entities, and more importantly in grading a potential reversal under treatment with therapeutic agents. The presented vascular network analysis will support vascular normalization assessment and future optimization of anti-angiogenic therapy.

Utility and Drawbacks of Chimeric Antigen Receptor T Cell (CAR-T) Therapy in Lung Cancer

The present treatments for lung cancer include surgical resection, radiation, chemotherapy, targeted therapy, and immunotherapy. Despite advances in therapies, the prognosis of lung cancer has not been substantially improved in recent years. Chimeric antigen receptor (CAR)-T cell immunotherapy has attracted growing interest in the treatment of various malignancies. Despite CAR-T cell therapy emerging as a novel potential therapeutic option with promising results in refractory and relapsed leukemia, many challenges limit its therapeutic efficacy in solid tumors including lung cancer. In this landscape, studies have identified several obstacles to the effective use of CAR-T cell therapy including antigen heterogeneity, the immunosuppressive tumor microenvironment, and tumor penetration by CAR-T cells. Here, we review CAR-T cell design; present the results of CAR-T cell therapies in preclinical and clinical studies in lung cancer; describe existing challenges and toxicities; and discuss strategies to improve therapeutic efficacy of CAR-T cells.

Bitter taste signaling in tracheal epithelial brush cells elicits innate immune responses to bacterial infection

Constant exposure of the airways to inhaled pathogens requires efficient early immune responses protecting against infections. How bacteria on the epithelial surface are detected and first-line protective mechanisms are initiated are not well understood. We have recently shown that tracheal brush cells (BCs) express functional taste receptors. Here we report that bitter taste signaling in murine BCs induces neurogenic inflammation. We demonstrate that BC signaling stimulates adjacent sensory nerve endings in the trachea to release the neuropeptides CGRP and substance P that mediate plasma extravasation, neutrophil recruitment, and diapedesis. Moreover, we show that bitter tasting quorum-sensing molecules from Pseudomonas aeruginosa activate tracheal BCs. BC signaling depends on the key taste transduction gene Trpm5, triggers secretion of immune mediators, among them the most abundant member of the complement system, and is needed to combat P. aeruginosa infections. Our data provide functional insight into first-line defense mechanisms against bacterial infections of the lung.

Extracellular Matrix in the Tumor Microenvironment and Its Impact on Cancer Therapy

Solid tumors are complex organ-like structures that consist not only of tumor cells but also of vasculature, extracellular matrix (ECM), stromal, and immune cells. Often, this tumor microenvironment (TME) comprises the larger part of the overall tumor mass. Like the other components of the TME, the ECM in solid tumors differs significantly from that in normal organs. Intratumoral signaling, transport mechanisms, metabolisms, oxygenation, and immunogenicity are strongly affected if not controlled by the ECM. Exerting this regulatory control, the ECM does not only influence malignancy and growth of the tumor but also its response toward therapy. Understanding the particularities of the ECM in solid tumor is necessary to develop approaches to interfere with its negative effect. In this review, we will also highlight the current understanding of the physical, cellular, and molecular mechanisms by which the pathological tumor ECM affects the efficiency of radio-, chemo-, and immunotherapy. Finally, we will discuss the various strategies to target and modify the tumor ECM and how they could be utilized to improve response to therapy.

LOX-catalyzed collagen stabilization is a proximal cause for intrinsic resistance to chemotherapy

The potential of altering the tumor ECM to improve drug response remains fairly unexplored. To identify targets for modification of the ECM aiming to improve drug response and overcome resistance, we analyzed expression data sets from pre-treatment patient cohorts. Cross-evaluation identified a subset of chemoresistant tumors characterized by increased expression of collagens and collagen-stabilizing enzymes. We demonstrate that strong collagen expression and stabilization sets off a vicious circle of self-propagating hypoxia, malignant signaling, and aberrant angiogenesis that can be broken by an appropriate auxiliary intervention: Interfering with collagen stabilization by inhibition of lysyl oxidases significantly enhanced response to chemotherapy in various tumor models, even in metastatic disease. Inhibition of collagen stabilization by itself can reduce or enhance tumor growth depending on the tumor type. The mechanistical basis for this behavior is the dependence of the individual tumor on nutritional supply on one hand and on high tissue stiffness for FAK signaling on the other.

Phenotypic distinctions between neural crest and placodal derived vagal C-fibres in mouse lungs

Two major types of nociceptors have been described in dorsal root ganglia (DRGs). In comparison, little is known about the vagal nociceptor subtypes. The vagus nerves provide much of the capsaicin-sensitive nociceptive innervation to visceral tissues, and are likely to contribute to the overall pathophysiology of visceral inflammatory diseases. The cell bodies of these afferent nerves are located in the vagal sensory ganglia referred to as nodose and jugular ganglia. Neurons of the nodose ganglion are derived from the epibranchial placodes, whereas jugular ganglion neurons are derived from the neural crest. In the adult mouse, however, there is often only a single ganglionic structure situated alone in the vagus nerve. By employing Wnt1Cre/R26R mice, which express β-galactosidase only in neural crest derived neurons, we found that this single vagal sensory ganglion is a fused ganglion consisting of both neural crest neurons in the rostral portion and non-neural crest (nodose) neurons in the more central and caudal portions of the structure. Based on their activation and gene expression profiles, we identified two major vagal capsaicin-sensitive nociceptor phenotypes, which innervated a defined target, namely the lung in adult mice. One subtype is non-peptidergic, placodal in origin, expresses P2X2 and P2X3 receptors, responds to α,β-methylene ATP, and expresses TRKB, GFRα1 and RET. The other phenotype is derived from the cranial neural crest and does not express P2X2 receptors and fails to respond to α,β-methylene ATP. This population can be further subdivided into two phenotypes, a peptidergic TRKA(+) and GFRα3(+) subpopulation, and a non-peptidergic TRKB(+) and GFRα1(+) subpopulation. Consistent with their similar embryonic origin, the TRPV1 expressing neurons in the rostral dorsal root ganglia were more similar to jugular than nodose vagal neurons. The data support the hypothesis that vagal nociceptors innervating visceral tissues comprise at least two major subtypes. Due to distinctions in their gene expression profile, each type will respond to noxious or inflammatory conditions in their own unique manner.

The acute phase protein alpha2-macroglobulin induces rat ventricular cardiomyocyte hypertrophy via ERK1,2 and PI3-kinase/Akt pathways

OBJECTIVE

Alpha2-macroglobulin (alpha2M) is an acute phase protein released to the serum upon challenges such as cardiac hypertrophy and infarction. Here we report on the role of alpha2M in the induction of hypertrophic cell growth, contractile responsiveness of rat ventricular cardiomyocytes, and on the underlying extracellular regulated kinase 1,2 (ERK1,2) and phosphoinositide 3-kinase (PI3-kinase)/Akt pathways.

METHODS

Cell volume and cross-sectional areas were assessed as parameters of hypertrophic growth, and real time RT-PCR for the analysis of hypertrophy-related genes was performed. Protein synthesis was analyzed by 14C-phenylalanine incorporation. Activation of ERK1,2, PI3-kinase and Akt was assessed by immunohistochemical analysis of phosphorylated proteins. Contractile responsiveness was investigated by determination of cell shortening following electrical field stimulation. Intracellular calcium concentration [Ca2+]i was determined by fluo-3 microfluorometry.

RESULTS

Treatment of ventricular cardiomyocytes for 24 h with alpha2M significantly increased cell volume and protein synthesis as well as expression of hypertrophy-associated genes [brain natriuretic protein (BNP), beta-myosin heavy chain (beta-MHC), myosin light chain-2 (MLC-2), atrial natriuretic factor (ANF), and skeletal alpha-actin]. Comparable effects were achieved by treatment of cells with an antibody directed against the alpha2M-receptor LDL receptor-related protein-1 (LRP-1) and counteracted upon coincubation with receptor-associated protein (RAP), suggesting an involvement of alpha2M-LRP-1 signalling. Furthermore, alpha2M treatment increased sarcoplasmic reticulum Ca2+-ATPase (SERCA-2a) expression, diastolic and systolic [Ca2+]i, and contractile responsiveness after electrical stimulation. Shortly after alpha2M stimulation, activation of ERK1,2, Akt, and PI3-kinase pathways was observed. Consequently, alpha2M-induced protein synthesis was inhibited upon treatment with the ERK1,2 inhibitor UO126 as well as by LY294002 and wortmannin, which inhibit PI3-kinase, and by rapamycin, which inhibits mammalian target of rapamycin (mTOR) downstream of Akt.

CONCLUSIONS

Our data show that alpha2M induces hypertrophic cell growth in rat ventricular cardiomyocytes via ERK1,2 and PI3-kinase/Akt and improves cardiac cell function.

Feed forward cycle of hypotonic stress-induced ATP release, purinergic receptor activation, and growth stimulation of prostate cancer cells

ATP is released in many cell types upon mechanical strain, the physiological function of extracellular ATP is largely unknown, however. Here we report that ATP released upon hypotonic stress stimulated prostate cancer cell proliferation, activated purinergic receptors, increased intracellular [Ca(2+)](i), and initiated downstream signaling cascades that involved MAPKs ERK1/2 and p38 as well as phosphatidylinositol 3-kinase (PI3K). MAPK activation, the calcium response as well as induction of cell proliferation upon hypotonic stress were inhibited by preincubation with the ATP scavenger apyrase, indicating that hypotonic stress-induced signaling pathways are elicited by released ATP. Hypotonic stress increased prostaglandin E(2) (PGE(2)) synthesis. Consequently, ATP release was inhibited by antagonists of PI3K (LY294002 and wortmannin), phospholipase A(2) (methyl arachidonyl fluorophosphonate (MAFP)), cyclooxygenase-2 (COX-2) (indomethacin, etodolac, NS398) and 5,8,11,14-eicosatetraynoic acid (ETYA), which are involved in arachidonic acid metabolism. Furthermore, ATP release was abolished in the presence of the adenylate cyclase (AC) inhibitor MDL-12,330A, indicating regulation of ATP-release by cAMP. The hypotonic stress-induced ATP release was significantly blunted when the ATP-mediated signal transduction cascade was inhibited on different levels, i.e. purinergic receptors were blocked by suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), the Ca(2+) response was inhibited upon chelation of intracellular Ca(2+) by 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), and ERK1,2 as well as p38 were inhibited by UO126 and SB203580, respectively. In summary our data demonstrate that hypotonic stress initiates a feed forward cycle of ATP release and purinergic receptor signaling resulting in proliferation of prostate cancer cells.