Combination of carboplatin and intermittent normobaric hyperoxia synergistically suppresses benzo[a]pyrene-induced lung cancer

Mitochondrial dysfunction of peripheral blood mononuclear cells is associated with lung carcinogenesis

The composition, quantity, and function of peripheral blood mononuclear cells (PBMCs) are closely correlated with tumorigenesis. However, the mechanisms of PBMCs in lung cancer are not clear. Mitochondria are energy factories of cells, and almost all cellular functions rely on their energy metabolism level. The present study aimed to test whether the mitochondrial function of PBMCs directly determines their tumor immune monitoring function. We recruited 211 subjects, including 105 healthy controls and 106 patients with recently diagnosed with lung cancer. The model of lung carcinogenesis induced by BaP was used in animal experiment, and the Bap carcinogenic metabolite, Benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide (BPDE), was used in cell experiment. We found that mitochondrial function of PBMCs decreased significantly in patients with new lung cancer, regardless of age. In vivo, BaP caused PBMC mitochondrial dysfunction in mice before the appearance of visible malignant tissue. Moreover, mitochondrial function decreased significantly in mice with lung cancers induced by BaP compared to those without lung cancer after BaP intervention. In vitro, BPDE also induced mitochondrial dysfunction and reduced the aggressiveness of PBMCs toward cancer cells. Furthermore, the changes in mitochondrial energy metabolism gene expression caused by BPDE are involved in this process. Thus, the mitochondrial function of PBMCs is a potential prognostic biomarker or therapeutic target to improve clinical outcomes in patients with lung cancer.

Comparison effects of Ferula gummosa essential oil and Beta-pinene Alginate nanoparticles on human melanoma and breast cancer cells proliferation and apoptotic index in short term normobaric hyperoxic model

BACKGROUND

Breast cancer is the most common cancer among women, and melanoma is the most dreadful type of skin cancer. Due to the side effects of chemotherapy drugs, the development of new herbal nano-medicines has been considered.

METHODS

This study first investigated the chemical composition of Ferula gummosa essential oil using GC-MS analysis; β-pinene, with 61.57%, was the major compound. Next, alginate nanoparticles containing β-pinene and the essential oil with particle sizes of 174 ± 7 and 137 ± 6 nm were prepared. Meanwhile, their zeta potentials were 12.4 ± 0.7 and 28.1 ± 1 mV. Besides, the successful loading of β-pinene and the essential oil in nanoparticles was confirmed using ATR-FTIR analysis. After that, their effects on viability and apoptotic index of human melanoma and breast cancer cells were investigated in normoxia and normobaric hyperoxia (NBO) conditions.

RESULTS

The best efficacy on A-375 and MDA-MB-231 cells was achieved by alginate nanoparticles containing the EO at hyperoxic and normoxia conditions; IC50 76 and 104 µg/mL. Besides, it affected apoptosis-involved genes; as Bax/Bcl-2 ratio was higher than 1, conditions for induction of apoptosis were obtained. Higher sensitivity was observed in the A-375 cell line treated with Alg-EO in the NBO model.

CONCLUSIONS

Alginate nanoparticles containing F. gummosa EO could be considered for further investigation in anticancer studies. Also, it may be expected that NBO can be a new strategy for delaying cancer progression and improving nanotherapy efficacy.

Effects of aging on accompanying intermittent hypoxia in a bleomycin-induced pulmonary fibrosis mouse model

BACKGROUND/AIMS

Obstructive sleep apnea (OSA) is prevalent in older patients with idiopathic pulmonary fibrosis (IPF); however, it is underrecognized. OSA is characterized by intermittent hypoxia (IH) and sleep fragmentation. In this study, we evaluated the effects of IH in an older mouse model of bleomycin-induced lung fibrosis.

METHODS

Bleomycin-induced mice (C57BL/6, female) were randomly divided into four groups of young vs. old and room air (RA)-exposed vs. IH-exposed. Mice were exposed to RA or IH (20 cycles/h, FiO2 nadir 7 ± 0.5%, 8 h/day) for four weeks. The mice were sacrificed on day 28, and blood, bronchoalveolar lavage (BAL) fluid, and lung tissue samples were obtained.

RESULTS

The bleomycin-induced IH-exposed (EBI) older group showed more severe inflammation, fibrosis, and oxidative stress than the other groups. The levels of inflammatory cytokines in the serum and BAL fluid increased in the EBI group. Hydroxyproline levels in the lung tissue increased markedly in the EBI group.

CONCLUSION

This study demonstrates the possible harmful impact of OSA in an elderly mouse model of lung fibrosis. This study further suggests that older patients with IPF and OSA may be more of a concern than younger patients with IPF. Further research is required in this area.

Hypoxia signaling in cancer: Implications for therapeutic interventions

Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.

The Normobaric Oxygen Paradox-Hyperoxic Hypoxic Paradox: A Novel Expedient Strategy in Hematopoiesis Clinical Issues

Hypoxia, even at non-lethal levels, is one of the most stressful events for all aerobic organisms as it significantly affects a wide spectrum of physiological functions and energy production. Aerobic organisms activate countless molecular responses directed to respond at cellular, tissue, organ, and whole-body levels to cope with oxygen shortage allowing survival, including enhanced neo-angiogenesis and systemic oxygen delivery. The benefits of hypoxia may be evoked without its detrimental consequences by exploiting the so-called normobaric oxygen paradox. The intermittent shift between hyperoxic-normoxic exposure, in addition to being safe and feasible, has been shown to enhance erythropoietin production and raise hemoglobin levels with numerous different potential applications in many fields of therapy as a new strategy for surgical preconditioning aimed at frail patients and prevention of postoperative anemia. This narrative review summarizes the physiological processes behind the proposed normobaric oxygen paradox, focusing on the latest scientific evidence and the potential applications for this strategy. Future possibilities for hyperoxic-normoxic exposure therapy include implementation as a synergistic strategy to improve a patient's pre-surgical condition, a stimulating treatment in critically ill patients, preconditioning of athletes during physical preparation, and, in combination with surgery and conventional chemotherapy, to improve patients' outcomes and quality of life.

Inspiratory hyperoxia suppresses lung cancer metastasis through a MYC/SLC1A5-dependent metabolic pathway

The lack of knowledge about the effect of inspiratory hyperoxia on the lung-specific tumour microenvironment and progression of lung cancer has attracted considerable attention. This study proposes that inspiratory hyperoxia has special significance for the malignant phenotype of lung cancer cells. The effects of different oxygenation parameters on the proliferation, apoptosis, invasion and migration of lung cancer cells were systematically evaluated in vitro and in vivo Our results reveal that inspiratory hyperoxia treatment (60% oxygen, 6 h·day^-1) not only has no tumour progression-promoting effects, but also suppresses lung cancer metastasis and promotes long-term survival. In addition, we combined transcriptome, proteome and metabolome analysis and found that hyperoxia treatment induced significant intracellular metabolic changes in lung cancer cells. Overall, we established that MYC/SLC1A5-induced metabolic reprogramming and glutamine addiction is a new mechanism that drives lung cancer metastasis, which can be significantly suppressed by inspiratory hyperoxia treatment. These findings are relevant to the debate on the perils, promises and antitumour effect of inspiratory hyperoxia, especially for patients with lung cancer.

Novel therapeutic modalities target cell signaling of Renin-Angiotensin system/NF-κB-induced cell cycle arrest and apoptosis in urethane-induced lung cancer in mice: An in vivo study

BACKGROUND

Lung cancer has risen to the top of the list of cancer-related deaths worldwide. Aliskiren is a direct renin inhibitor.

AIM

This study aims to investigate the impact of cell signaling of Renin-Angiotensin system (RAS)/NF-κB on lung cancer by investigating the potential therapeutic effects of aliskiren for lung cancer treatment in urethane-induced lung cancer in mice.

METHODS

Male BALB/c mice were randomly assigned to one of five treatment groups for 150 days, including (1) normal control; (2) aliskiren (25 mg/kg/i.p) daily, (3) urethane at a dose of 1.5 g/kg (i.p) at Day 1 and 60 (nonsmall cell lung cancer[NSCLC] group) (4) NSCLC mice received carboplatin (15 mg/kg/i.p) every other day for the last 4 successive weeks and (5) NSCLC mice treated with aliskiren daily. Tumor size was determined based on blood sampling, and lungs were isolated for biochemical analysis, western blot analysis assay, and histopathological examination.

RESULTS

Urethane demonstrated significant changes in all biochemical and molecular parameters and histological patterns. Aliskiren-treated mice had significantly lower levels of NF-κB p65, Bcl-2, cyclin D1, ICAM-1, MMP-2, and Nrf2, with an increase in the catalytic activity of caspase-3 due to its RAS inhibitory mechanism. The combined urethane administration with aliskiren demonstrated a significant improvement in the histopathological examination.

CONCLUSION

RAS/NF-B cell signaling is a potential therapeutic target for preventing and treating lung adenocarcinoma, evidenced by the fundamental cytotoxic mechanism and attenuation of metastasis and angiogenesis induced by the treatment of NSCLC mice with aliskiren.

Hyperbaric Oxygen Therapy as a Complementary Treatment in Glioblastoma-A Scoping Review

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. The mainstay of management for GBM is surgical resection, radiation (RT), and chemotherapy (CT). Even with optimized multimodal treatment, GBM has a high recurrence and poor survival rates ranging from 12 to 24 months in most patients. Recently, relevant advances in understanding GBM pathophysiology have opened new avenues for therapies for recurrent and newly diagnosed diseases. GBM's hypoxic microenvironment has been shown to be highly associated with aggressive biology and resistance to RT and CT. Hyperbaric oxygen therapy (HBOT) may increase anticancer therapy sensitivity by increasing oxygen tension within the hypoxic regions of the neoplastic tissue. Previous data have investigated HBOT in combination with cytostatic compounds, with an improvement of neoplastic tissue oxygenation, inhibition of HIF-1α activity, and a significant reduction in the proliferation of GBM cells. The biological effect of ionizing radiation has been reported to be higher when it is delivered under well-oxygenated rather than anoxic conditions. Several hypoxia-targeting strategies reported that HBOT showed the most significant effect that could potentially improve RT outcomes, with higher response rates and survival and no serious adverse events. However, further prospective and randomized studies are necessary to validate HBOT's effectiveness in the 'real world' GBM clinical practice.

Implications of Hyperoxia over the Tumor Microenvironment: An Overview Highlighting the Importance of the Immune System

Hyperoxia is used in order to counteract hypoxia effects in the TME (tumor microenvironment), which are described to boost the malignant tumor phenotype and poor prognosis. The reduction of tumor hypoxic state through the formation of a non-aberrant vasculature or an increase in the toxicity of the therapeutic agent improves the efficacy of therapies such as chemotherapy. Radiotherapy efficacy has also improved, where apoptotic mechanisms seem to be implicated. Moreover, hyperoxia increases the antitumor immunity through diverse pathways, leading to an immunopermissive TME. Although hyperoxia is an approved treatment for preventing and treating hypoxemia, it has harmful side-effects. Prolonged exposure to high oxygen levels may cause acute lung injury, characterized by an exacerbated immune response, and the destruction of the alveolar-capillary barrier. Furthermore, under this situation, the high concentration of ROS may cause toxicity that will lead not only to cell death but also to an increase in chemoattractant and proinflammatory cytokine secretion. This would end in a lung leukocyte recruitment and, therefore, lung damage. Moreover, unregulated inflammation causes different consequences promoting tumor development and metastasis. This process is known as protumor inflammation, where different cell types and molecules are implicated; for instance, IL-1β has been described as a key cytokine. Although current results show benefits over cancer therapies using hyperoxia, further studies need to be conducted, not only to improve tumor regression, but also to prevent its collateral damage.

Repurposing of sildenafil as antitumour; induction of cyclic guanosine monophosphate/protein kinase G pathway, caspase-dependent apoptosis and pivotal reduction of Nuclear factor kappa light chain enhancer of activated B cells in lung cancer

OBJECTIVES

Lung cancer is one of the most frequent types of cancers that lead to death. Sildenafil is a potent inhibitor of phosphodiesterase-5 and showed potential anticancer effects, which has not yet been fully evaluated. Thus, this study aims to investigate the potential anticancer effect of sildenafil in urethane-induced lung cancer in BALB/c mice.

METHODS

Five-week-old male BALB/c mice were treated with either (i) normal saline only, (ii) sildenafil only 50 mg kg-1/ P.O every other day for the last four successive weeks, (iii) urethane 1.5 gm kg-1 i.p (at day 1 and day 60), (iv) carboplatin after urethane induction, or (v) sildenafil after urethane induction.

KEY FINDINGS

It was shown that sildenafil significantly increased the levels of cGMP and Caspase-3 with a reduction of NF-κB, Bcl-2, Cyclin D1, intercellular adhesion molecule 1, matrix metalloproteinase-2 levels and normalisation of Nrf2 along with pronounced improvement in the histological patterns.

CONCLUSIONS

These results indicated that sildenafil markedly induces cell cycle arrest, apoptosis and inhibits the metastatic activity through activation of cyclic guanosine monophosphate/protein kinase G pathway and down-regulation of cyclin D1 and nuclear factor kappa light chain enhancer of activated B cells with downstream anti-apoptotic gene Bcl-2, which underscores the critical importance of future using sildenafil in the treatment of lung cancer.

Role of hyperoxic treatment in cancer

IMPACT STATEMENT

Tumor hypoxia promotes cancer cell aggressiveness, and is strongly associated with poor prognosis across multiple tumor types. The hypoxic microenvironments inside tumors also limit the effectiveness of radiotherapy, chemotherapy, and immunotherapy. Several approaches to eliminate hypoxic state in tumors have been proposed to delay cancer progression and improve therapeutic efficacies. This review will summarize current knowledge on hyperoxia, used alone or in combination with other therapeutic modalities, in cancer treatment. Molecular mechanisms and undesired side effects of hyperoxia will also be discussed.

Hyperoxia Alters Ultrastructure and Induces Apoptosis in Leukemia Cell Lines

Oxygenation conditions are crucial for growth and tumor progression. Recent data suggests a decrease in cancer cell proliferation occurring after exposure to normobaric hyperoxia. Those changes are associated with fractal dimension. The purpose of this research was to study the impact of hyperoxia on apoptosis and morphology of leukemia cell lines. Two hematopoietic lymphoid cancer cell lines (a T-lymphoblastoid line, JURKAT and a B lymphoid line, CCRF-SB) were tested under conditions of normobaric hyperoxia (FiO₂ > 60%, ± 18h) and compared to a standard group (FiO₂ = 21%). We tested for apoptosis using a caspase-3 assay. Cell morphology was evaluated by cytospin, microphotography after coloration, and analysis by a fractal dimension calculation software. Our results showed that exposure of cell cultures to transient normobaric hyperoxia induced apoptosis (elevated caspase-3) as well as significant and precocious modifications in cell complexity, as highlighted by increased fractal dimensions in both cell lines. These features are associated with changes in structure (pycnotic nucleus and apoptosis) recorded by microscopic analysis. Such morphological alterations could be due to several molecular mechanisms and rearrangements in the cancer cell, leading to cell cycle inhibition and apoptosis as shown by caspase-3 activity. T cells seem less resistant to hyperoxia than B cells.

Systemic Evaluation on the Pharmacokinetics of Platinum-Based Anticancer Drugs From Animal to Cell Level: Based on Total Platinum and Intact Drugs

Cisplatin, carboplatin, and oxaliplatin are the common platinum-based anticancer drugs widely used in the chemotherapeutic treatment of solid tumors in clinic. However, the comprehensive pharmacokinetics of platinum-based anticancer drugs has not been fully understood yet. This leads to many limitations for the further studies on their pharmacology and toxicology. In this study, we conduct a systemic evaluation on the pharmacokinetics of three platinum analogues at animal and cell levels, with quantification of both total platinum and intact drugs. A detailed animal study to address and compare the different pharmacokinetic behaviors of three platinum analogues has been conducted in three biological matrices: blood, plasma, and ultrafiltrate plasma. Carboplatin showed an obviously different pharmacokinetic characteristic from cisplatin and oxaliplatin. On the one hand, carboplatin has the highest proportion of Pt distribution in ultrafiltrate plasma. On the other hand, carboplatin has the highest intact drug exposure and longest intact drug elimination time in blood, plasma, and ultrafiltrate plasma, which may explain its high hematotoxicity. Additionally, the cellular and subcellular pharmacokinetics of oxaliplatin in two colon cancer HCT-116/LOVO cell lines has been elucidated for the first time. The biotransformation of intact oxaliplatin in cells was rapid with a fast elimination, however, the generated platinum-containing metabolites still exist within cells. The distribution of total platinum in the cytosol is higher than in the mitochondria, followed by the nucleus. Enrichment of platinum in mitochondria may affect the respiratory chain or energy metabolism, and further lead to cell apoptosis, which may indicate mitochondria as another potential target for efficacy and toxicity of oxaliplatin.