Prospective exosome-focused translational research for afatinib study of non-small cell lung cancer patients expressing EGFR (EXTRA study)

Prospective exosome-focused translational research for afatinib (EXTRA) study of patients with nonsmall cell lung cancer harboring EGFR mutation: an observational clinical study

Background

The exosome-focused translational research for afatinib (EXTRA) study is the first trial to identify novel predictive biomarkers for longer treatment efficacy of afatinib in patients with epidermal growth factor receptor (EGFR) mutation-positive nonsmall cell lung cancer (NSCLC) via a comprehensive association study using genomic, proteomic, epigenomic, and metabolomic analyses.

Objectives

We report details of the clinical portion prior to omics analyses.

Design

A prospective, single-arm, observational study was conducted using afatinib 40 mg/day as an initial dose in untreated patients with EGFR mutation-positive NSCLC. Dose reduction to 20 mg every other day was allowed.

Methods

Progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were evaluated.

Results

A total of 103 patients (median age 70 years, range 42-88 years) were enrolled from 21 institutions in Japan between February 2017 and March 2018. After a median follow-up of 35.0 months, 21% remained on afatinib treatment, whereas 9% had discontinued treatment because of AEs. The median PFS was 18.4 months, with a 3-year PFS rate of 23.3%. The median afatinib treatment duration in patients with final doses of 40 (n = 27), 30 (n = 23), and 20 mg/day (n = 35), and 20 mg every other day (n = 18) were 13.4, 15.4, 18.8, and 18.3 months, respectively. The median OS was not reached, with a 3-year OS rate of 58.5%. The median OS in patients who did (n = 25) and did not (n = 78) receive osimertinib during the entire course of treatment were 42.4 months and not reached, respectively (p = 0.654).

Conclusions

As the largest prospective study in Japan, this study confirmed favorable OS following first-line afatinib in patients with EGFR mutation-positive NSCLC in a real-world setting. Further analysis of the EXTRA study is expected to identify novel predictive biomarkers for afatinib.

Trial registration

UMIN-CTR identifier (UMIN000024935, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_his_list.cgi?recptno=R000028688.

Metabolomics of Extracellular Vesicles: A Future Promise of Multiple Clinical Applications

Extracellular vesicles (EVs) can contain DNA, RNA, proteins and metabolic molecules from primary origins; they are coated with a phospholipid bilayer membrane and released by cells into the extracellular matrix. EVs can be obtained from various body liquids, including the blood, saliva, cerebrospinal fluid, and urine. As has been proved, EVs-mediated transfer of biologically active molecules is crucial for various physiological and pathological processes. Extensive investigations have already begun to explore the diagnosis and prognosis potentials for EVs. Furthermore, research has continued to recognize the critical role of nucleic acids and proteins in EVs. However, our understanding of the comprehensive effects of metabolites in these nanoparticles is currently limited and in its infancy. Therefore, we have attempted to summarize the recent research into the metabolomics of EVs in relation to potential clinical applications and discuss the problems and challenges that have occurred, to provide more guidance for the future development in this field.

Role of exosomes in lung cancer: A comprehensive insight from immunomodulation to theragnostic applications

Exosomes are 30 to 150 nm-diameter lipid bilayer-enclosed extracellular vesicles that enable cell-to-cell communication through secretion and uptake. The exosomal cargoes contain RNA, lipids, proteins, and metabolites which can be delivered to recipient cells in vivo. In a healthy lung, exosomes facilitate interaction between adaptive and innate immunity and help maintain normal lung physiology. However, tumor-derived exosomes in lung cancer (LC) can, on the other hand, restrict immune cell proliferation, cause apoptosis in activated CD8+ T effector cells, reduce natural killer cell activity, obstruct monocyte differentiation, and promote proliferation of myeloid-derived suppressor and regulatory T cells. In addition, exosomes in the tumor microenvironment may also play a critical role in cancer progression and the development of drug resistance. In this review, we aim to comprehensively examine the current updates on the role of exosomes in lung carcinogenesis and their potential application as a diagnostic, prognostic, and therapeutic tool in lung cancer.

Epidermal growth factor/epidermal growth factor receptor signaling blockage inhibits tumor cell-derived exosome uptake by oral squamous cell carcinoma through macropinocytosis

Various cell types secrete exosomes into their surrounding extracellular space, which consequently affect the function and activity of recipient cells. Numerous studies have showed that tumor cell‐derived exosomes play important roles in tumor growth and progression. Although a variety of endocytic pathways are reportedly involved in the cellular uptake of exosomes, detailed mechanisms remain unknown. The present study demonstrated that treatment with recombinant epidermal growth factor (EGF) time‐ and dose‐dependently promoted cellular uptake of oral squamous cell carcinoma (OSCC) cell‐derived exosomes into OSCC cells themselves. Conversely, EGF receptor (EGFR) knockdown and treatment with EGFR inhibitors, including erlotinib and cetuximab, abrogated OSCC cell uptake of exosomes. The macropinocytosis inhibitor 5‐(N‐ethyl‐N‐isopropyl) amiloride (EIPA) blocked the effects of active EGF/EGFR signaling on uptake of OSCC cell‐derived exosomes. These EGFR inhibitors also suppressed OSCC cell‐derived exosome‐induced proliferation, migration, invasion, stemness, and chemoresistance of OSCC cells. Taken together, the data presented herein suggest that EGFR inhibitors might inhibit the malignant potential of OSCC cells through direct inhibition of not only EGFR downstream signaling pathway but also cellular uptake of OSCC cell‐derived exosomes through macropinocytosis.

Formation, contents, functions of exosomes and their potential in lung cancer diagnostics and therapeutics

Lung cancer is the leading cause of cancer-related death worldwide due to diagnosis in the advanced stage and drug resistance in the subsequent treatments. Development of novel diagnostic and therapeutic methods is urged to improve the disease outcome. Exosomes are nano-sized vehicles which transport different types of biomolecules intercellularly, including DNA, RNA and proteins, and are implicated in cross-talk between cells and their surrounding microenvironment. Tumor-derived exosomes (TEXs) have been revealed to strongly influence the tumor microenvironment, antitumor immunoregulatory activities, tumor progression and metastasis. Potential of TEXs as biomarkers for lung cancer diagnosis, prognosis and treatment prediction is supported by numerous studies. Moreover, exosomes have been proposed to be promising drug carriers. Here, we review the mechanisms of exosomal formation and uptake, the functions of exosomes in carcinogenesis, and potential clinical utility of exosomes as biomarkers, tumor vaccine and drug delivery vehicles in the diagnosis and therapeutics of lung cancer.

Exosomes: a new perspective in EGFR-mutated lung cancer

Exosomes are major contributors in cell to cell communication due to their ability to transfer biological material such as protein, RNA, DNA, and miRNA. Additionally, they play a role in tumor initiation, promotion, and progression, and recently, they have emerged as a potential source of information on tumor detection and may be useful as diagnostic, prognostic, and predictive tools. This review focuses on exosomes from lung cancer with a focus on EGFR mutations. Here, we outline the role of exosomes and their functional effect in carcinogenesis, tumor progression, and metastasis. Finally, we discuss the possibility of exosomes as novel biomarkers in early detection, diagnosis, assessment of prognosis, and prediction of therapeutic response in EGFR-mutated lung cancer.

Cutaneous Thermal Injury Modulates Blood and Skin Metabolomes Differently in a Murine Model

As the field of metabolomics develops further, investigations of how the metabolome is affected following thermal injury may be helpful to inform diagnostics and guide treatments. In this study, changes to the metabolome were tested and validated in a murine burn injury model. After a 30% total body surface scald injury or sham procedure sera and skin biopsies were collected at 1, 2, 6, or 24 hr.

Burn-specific changes in the metabolome were detected compared to sham animals. The sera metabolome exhibited a more rapid response to burn injury than that of the skin and it peaked more proximal to injury (6 vs 24 hr). Progression of metabolic response in the skin was less synchronous and showed a higher overlap of the significantly modified metabolites (SMMs) among tested time-points. Top affected pathways identified by SMMs of skin included inositol phosphate metabolism, ascorbate and alderate metabolism, caffeine metabolism, and the pentose phosphate pathway. Future research is warranted in human and larger animal models to further elucidate the role of metabolomic perturbations and the pathophysiology following burn injury.

Mechanisms of Action of EGFR Tyrosine Kinase Receptor Incorporated in Extracellular Vesicles

EGFR and some of the cognate ligands extensively traffic in extracellular vesicles (EVs) from different biogenesis pathways. EGFR belongs to a family of four homologous tyrosine kinase receptors (TKRs). This family are one of the major drivers of cancer and is involved in several of the most frequent malignancies such as non-small cell lung cancer, breast cancer, colorectal cancer and ovarian cancer. The carrier EVs exert crucial biological effects on recipient cells, impacting immunity, pre-metastatic niche preparation, angiogenesis, cancer cell stemness and horizontal oncogene transfer. While EV-mediated EGFR signalling is important to EGFR-driven cancers, little is known about the precise mechanisms by which TKRs incorporated in EVs play their biological role, their stoichiometry and associations to other proteins relevant to cancer pathology and EV biogenesis, and their means of incorporation in the target cell. In addition, it remains unclear whether different subtypes of EVs incorporate different complexes of TKRs with specific functions. A raft of high spatial and temporal resolution methods is emerging that could solve these and other questions regarding the activity of EGFR and its ligands in EVs. More importantly, methods are emerging to block or mitigate EV activity to suppress cancer progression and drug resistance. By highlighting key findings and areas that remain obscure at the intersection of EGFR signalling and EV action, we hope to cross-fertilise the two fields and speed up the application of novel techniques and paradigms to both.

Extracellular Vesicles in Non-Small-Cell Lung Cancer: Functional Role and Involvement in Resistance to Targeted Treatment and Immunotherapy

Targeted and immunological therapies have become the gold standard for a large portion of non-small cell lung cancer (NSCLC) patients by improving significantly clinical prognosis. However, resistance mechanisms inevitably develop after a first response, and almost all patients undergo progression. The knowledge of such a resistance mechanism is crucial to improving the efficacy of therapies. So far, monitoring therapy responses through liquid biopsy has been carried out mainly in terms of circulating tumor (ctDNA) analysis. However, other particles of tumor origin, such as extracellular vehicles (EVs) represent an emerging tool for the studying and monitoring of resistance mechanisms. EVs are now considered to be ubiquitous mediators of cell-to-cell communication, allowing cells to exchange biologically active cargoes that vary in response to the microenvironment and include proteins, metabolites, RNA species, and nucleic acids. Novel findings on the biogenesis and fate of these vesicles reveal their fundamental role in cancer progression, with foreseeable and not-far-to-come clinical applications in NSCLC.