Hypoxia Induces Resistance to EGFR Inhibitors in Lung Cancer Cells via Upregulation of FGFR1 and the MAPK Pathway

An intelligent hypoxia-relieving chitosan-based nanoplatform for enhanced targeted chemo-sonodynamic combination therapy on lung cancer

The clinical efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs)-based targeted molecular therapies (TMT) is inevitably hampered by the development of acquired drug resistance in non-small cell lung cancer (NSCLC) treatment. Sonodymanic therapy (SDT) is a promising new cancer treatment approach, but its effects are restricted by tumor hypoxia. Herein, a nanoplatform fabricated by erlotinib-modified chitosan loading sonosensitizer hematoporphyrin (HP) and oxygen-storing agent perfluorooctyl bromide (PFOB), namely CEPH, was developed to deliver HP to erlotinib-sensitive cells. CEPH with ultrasound could alleviate hypoxia inside the three-dimensional multicellular tumor spheroids, suppress NSCLC cell growth under normoxic or hypoxic condition, and enhance TMT/SDT synergistic effects through elevated production of reactive oxygen species, decrease of mitochondrial membrane potential, and down-regulation of the expression of the proteins EGFR, p-EGFR, and HIF-1α. Hence, CEPH could be a potential nanoplatform to improve the efficacy of oxygen-dependent SDT and overcome hypoxia-induced TMT resistance for enhanced synergistic TMT/SDT.

Engineered Cytokines for Cancer and Autoimmune Disease Immunotherapy

Cytokine signaling is critical to a range of biological processes including cell development, tissue repair, aging, and immunity. In addition to acting as key signal mediators of the immune system, cytokines can also serve as potent immunotherapies with more than 20 recombinant products currently Food and Drug Administration (FDA)-approved to treat conditions including hepatitis, multiple sclerosis, arthritis, and various cancers. Yet despite their biological importance and clinical utility, cytokine immunotherapies suffer from intrinsic challenges that limit their therapeutic potential including poor circulation, systemic toxicity, and low tissue- or cell-specificity. In the past decade in particular, methods have been devised to engineer cytokines in order to overcome such challenges and here, the myriad strategies are reviewed that may be employed in order to improve the therapeutic potential of cytokine and chemokine immunotherapies with applications in cancer and autoimmune disease therapy, as well as tissue engineering and regenerative medicine. For clarity, these strategies are collected and presented as they vary across size scales, ranging from single amino acid substitutions, to larger protein-polymer conjugates, nano/micrometer-scale particles, and macroscale implants. Together, this work aims to provide readers with a timely view of the field of cytokine engineering with an emphasis on early-stage therapeutic approaches.

SIRT1/PGC-1α/PPAR-γ Correlate With Hypoxia-Induced Chemoresistance in Non-Small Cell Lung Cancer

Resistance is the major cause of treatment failure and disease progression in non-small cell lung cancer (NSCLC). There is evidence that hypoxia is a key microenvironmental stress associated with resistance to cisplatin, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), and immunotherapy in solid NSCLCs. Numerous studies have contributed to delineating the mechanisms underlying drug resistance in NSCLC; nevertheless, the mechanisms involved in the resistance associated with hypoxia-induced molecular metabolic adaptations in the microenvironment of NSCLC remain unclear. Studies have highlighted the importance of posttranslational regulation of molecular mediators in the control of mitochondrial function in response to hypoxia-induced metabolic adaptations. Hypoxia can upregulate the expression of sirtuin 1 (SIRT1) in a hypoxia-inducible factor (HIF)-dependent manner. SIRT1 is a stress-dependent metabolic sensor that can deacetylate some key transcriptional factors in both metabolism dependent and independent metabolic pathways such as HIF-1α, peroxisome proliferator-activated receptor gamma (PPAR-γ), and PPAR-gamma coactivator 1-alpha (PGC-1α) to affect mitochondrial function and biogenesis, which has a role in hypoxia-induced chemoresistance in NSCLC. Moreover, SIRT1 and HIF-1α can regulate both innate and adaptive immune responses through metabolism-dependent and -independent ways. The objective of this review is to delineate a possible SIRT1/PGC-1α/PPAR-γ signaling-related molecular metabolic mechanism underlying hypoxia-induced chemotherapy resistance in the NSCLC microenvironment. Targeting hypoxia-related metabolic adaptation may be an attractive therapeutic strategy for overcoming chemoresistance in NSCLC.

Hypoxia in Lung Cancer Management: A Translational Approach

Simple Summary

Hypoxia is a common feature of lung cancers. Nonetheless, no guidelines have been established to integrate hypoxia-associated biomarkers in patient management. Here, we discuss the current knowledge and provide translational novel considerations regarding its clinical detection and targeting to improve the outcome of patients with non-small-cell lung carcinoma of all stages.

Abstract

Lung cancer represents the first cause of death by cancer worldwide and remains a challenging public health issue. Hypoxia, as a relevant biomarker, has raised high expectations for clinical practice. Here, we review clinical and pathological features related to hypoxic lung tumours. Secondly, we expound on the main current techniques to evaluate hypoxic status in NSCLC focusing on positive emission tomography. We present existing alternative experimental approaches such as the examination of circulating markers and highlight the interest in non-invasive markers. Finally, we evaluate the relevance of investigating hypoxia in lung cancer management as a companion biomarker at various lung cancer stages. Hypoxia could support the identification of patients with higher risks of NSCLC. Moreover, the presence of hypoxia in treated tumours could help clinicians predict a worse prognosis for patients with resected NSCLC and may help identify patients who would benefit potentially from adjuvant therapies. Globally, the large quantity of translational data incites experimental and clinical studies to implement the characterisation of hypoxia in clinical NSCLC management.

Managing Acquired Resistance to Third-Generation EGFR Tyrosine Kinase Inhibitors Through Co-Targeting MEK/ERK Signaling

Although epidermal growth factor receptor (EGFR)-targeted therapy has improved clinical outcomes of patients with advanced non-small-cell lung cancer (NSCLC) carrying activating EGFR mutations, the development of acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs), including the promising third-generation ones, results in disease progression and has become an unavoidable problem that limits patient long-term benefit. The third-generation EGFR-TKIs, osimertinib and almonertinib, are now approved for the treatment of advanced NSCLC patients harboring activating EGFR mutations (first-line) and/or the resistant T790M mutation (second-line). Clinically, appropriate management of acquired resistance to third-generation EGFR-TKIs will substantially improve their long-term efficacy against EGFR-mutant NSCLC. Recent preclinical and clinical studies suggest that activation of the Ras/Raf/MEK/ERK signaling pathway may be an important resistance mechanism and accordingly co-targeting this pathway effectively overcomes and abrogates acquired resistance to third-generation EGFR-TKIs. This review focuses on discussing the scientific rationale for and potential of co-targeting MEK/ERK signaling in delaying and overcoming acquired resistance to third-generation EGFR-TKIs, particularly osimertinib.