Safety and Preclinical Efficacy of Aerosol Pioglitazone on Lung Adenoma Prevention in A/J Mice

Inhaled Medicines for Targeting Non-Small Cell Lung Cancer

Throughout the years, considerable progress has been made in methods for delivering drugs directly to the lungs, which offers enhanced precision in targeting specific lung regions. Currently, for treatment of lung cancer, the prevalent routes for drug administration are oral and parenteral. These methods, while effective, often come with side effects including hair loss, nausea, vomiting, susceptibility to infections, and bleeding. Direct drug delivery to the lungs presents a range of advantages. Notably, it can significantly reduce or even eliminate these side effects and provide more accurate targeting of malignancies. This approach is especially beneficial for treating conditions like lung cancer and various respiratory diseases. However, the journey towards perfecting inhaled drug delivery systems has not been without its challenges, primarily due to the complex structure and functions of the respiratory tract. This comprehensive review will investigate delivery strategies that target lung cancer, specifically focusing on non-small-cell lung cancer (NSCLC)-a predominant variant of lung cancer. Within the scope of this review, active and passive targeting techniques are covered which highlight the roles of advanced tools like nanoparticles and lipid carriers. Furthermore, this review will shed light on the potential synergies of combining inhalation therapy with other treatment approaches, such as chemotherapy and immunotherapy. The goal is to determine how these combinations might amplify therapeutic results, optimizing patient outcomes and overall well-being.

The effects of Crocus sativus extract on inhaled paraquat-induced lung inflammation, oxidative stress, pathological changes and tracheal responsiveness in rats

Paraquat is a green liquid toxin that is used in agriculture and can induce multi-organ including lung injury. Various pharmacological effects of Crocus sativus (C. sativus) were indicated in previous studies. In this research, the effects of C. sativus extract and pioglitazone on inhaled paraquat-induced lung inflammation, oxidative stress, pathological changes, and tracheal responsiveness were studied in rats. Eight groups of rats (n = 7 in each) including control (Ctrl), untreated paraquat aerosol exposed group (54 mg/m3, 8 times in alternate days), paraquat treated groups with dexamethasone (0.03 mg/kg/day, Dexa) as positive control, two doses of C. sativus extract (20 and 80 mg/kg/day, CS-20 and CS-80), pioglitazone (5 and 10 mg/kg/day, Pio-5 and Pio-10), and the combination of CS-20 + Pio-5 were studied. Total and differential WBC, levels of oxidant and antioxidant biomarkers in the BALF, lung tissue cytokine levels, tracheal responsiveness (TR), and pathological changes were measured. The levels of IFN-γ, IL-10, SOD, CAT, thiol, and EC50 were reduced, but MDA level, total and differential WBC count in the BALF and lung pathological changes were increased in the paraquat group (all, p < 0.001). The levels of IFN-γ, IL-10, SOD, CAT, thiol and EC50 were increased but BALF MDA level, lung pathological changes, total and differential WBC counts were reduced in all treated groups. The effects of C. sativus high dose and combination groups on measured parameters were equal or even higher than dexamethasone (p < 0.05 to p < 0.001). The effects of the combination of CS-20 + Pio-5 on most variables were significantly higher than CS-20 and Pio-5 alone (p < 0.05 to p < 0.001). C. sativus treatment improved inhaled paraquat-induced lung injury similar to dexamethasone and showed a synergistic effect with pioglitazone, suggesting possible PPAR-γ receptor-mediated effects of the plant.

Drug Repurposing in Non-Small Cell Lung Carcinoma: Old Solutions for New Problems

Lung cancer is the second most common cancer and the leading cause of cancer-related deaths in 2022. The majority (80%) of lung cancer cases belong to the non-small cell lung carcinoma (NSCLC) subtype. Despite the increased screening efforts, the median five-year survival of metastatic NSCLC remains low at approximately 3%. Common treatment approaches for NSCLC include surgery, multimodal chemotherapy, and concurrent radio and chemotherapy. NSCLC exhibits high rates of resistance to treatment, driven by its heterogeneity and the plasticity of cancer stem cells (CSCs). Drug repurposing offers a faster and cheaper way to develop new antineoplastic purposes for existing drugs, to help overcome therapy resistance. The decrease in time and funds needed stems from the availability of the pharmacokinetic and pharmacodynamic profiles of the Food and Drug Administration (FDA)-approved drugs to be repurposed. This review provides a synopsis of the drug-repurposing approaches and mechanisms of action of potential candidate drugs used in treating NSCLC, including but not limited to antihypertensives, anti-hyperlipidemics, anti-inflammatory drugs, anti-diabetics, and anti-microbials.

PPARgamma agonism inhibits progression of premalignant lesions in a murine lung squamous cell carcinoma model

The N-nitroso-trischloroethylurea (NTCU)-induced mouse model of squamous lung carcinoma recapitulates human disease from premalignant dysplasia through invasive tumors, making it suitable for preclinical chemoprevention drug testing. Pioglitazone is a peroxisome proliferator-activated receptor γ (PPARγ) agonist shown to prevent lung tumors in preclinical models. We investigated pioglitazone's effect on lesion development and markers of potential preventive mechanisms in the NTCU model. Female FVB/N mice were exposed to vehicle, NTCU or NTCU + oral pioglitazone for 32 weeks. NTCU induces the appearance of basal cells in murine airways while decreasing/changing their epithelial cell makeup, resulting in development of bronchial dysplasia. H&E and keratin 5 (KRT5) staining were used to detect and grade squamous lesions in formalin fixed lungs. mRNA expression of epithelial to mesenchymal transition (EMT) markers and basal cell markers were measured by qPCR. Dysplasia persistence markers desmoglein 3 and polo like kinase 1 were measured by immunohistochemistry. Basal cell markers KRT14 and p63, club cell specific protein and ciliated cell marker acetylated tubulin were measured by immunofluorescence. Pioglitazone treatment significantly reduced squamous lesions and the presence of airway basal cells, along with increasing normal epithelial cells in the airways of NTCU-exposed mice. Pioglitazone also significantly influenced EMT gene expression to promote a more epithelial, and less mesenchymal, phenotype. Pioglitazone reduced the presence of squamous dysplasia and maintained normal airway cell composition. This work increases the knowledge of mechanistic pathways in PPARγ agonism for lung cancer interception and provides a basis for further investigation to advance this chemoprevention strategy.

Intranasal iloprost prevents tumors in a murine lung carcinogenesis model

Lung cancer chemoprevention with the prostacyclin analogue iloprost is the most promising approach to date for intercepting progression of premalignant lung lesions in former smokers. Previous pre-clinical studies of iloprost used oral delivery, but a study modeling delivery directly to the target organ was needed. In vivo and in vitro studies have identified gene expression changes following iloprost treatment, including increased E-cadherin and PPAR𝛄 and decreased COX2 and Vimentin. We used tumor counts and gene expression to demonstrate the effectiveness of intranasal delivery of iloprost in a murine model of premalignant adenomas. Intranasal delivery of iloprost reduced adenoma multiplicity14 weeks after urethane exposure in FVB mice compared to untreated urethane controls. Intranasal iloprost reversed urethane-induced gene expression changes in tumors and whole lung. These results correspond to previous studies of oral iloprost and in vitro treatment of human bronchial epithelial cells. This study demonstrates that intranasal delivery of iloprost in a mouse model of lung premalignant lesions is effective chemoprevention. This will be an essential tool for exploring mechanisms and outcomes of iloprost chemoprevention, along with supporting ongoing clinical trials of inhaled iloprost chemoprevention.

Effects of PPAR-γ agonists on oral cancer cell lines: Potential horizons for chemopreventives and adjunctive therapies

BACKGROUND

Peroxisome proliferator-activated receptor-gamma (PPAR-γ) activators have anti-cancer effects. Our objective was to determine the effect of PPAR-γ ligands 15-deoxy-D^12,14 -Prostaglandin J₂ (15-PGJ₂ ) and ciglitazone on proliferation, apoptosis, and NF-κB in human oral squamous cell carcinoma cell lines.

METHODS

NA and CA9-22 cells were treated in vitro with 15-PGJ₂ and ciglitazone. Proliferation was measured by MTT colorimetric assay and cell cycle analysis performed via flow cytometry, apoptosis by caspase-3 colorimetric assay and poly-(ADP-ribose) polymerase cleavage on Western blot, and NF-κB activation by luciferase assays.

RESULTS

MTT assays demonstrated dose-dependent decreases after 15-PGJ₂ treatment in both cell lines, and S-phase cell cycle arrest was also demonstrated. NF-κB luciferase reporter gene activity decreased seven- and eightfold in NA and CA9-22 cells, respectively. Caspase-3 activity increased two- and eightfold in NA and CA9-22 cells, respectively.

CONCLUSIONS

Our results suggest these agents, in addition to activating PPAR-γ, can downregulate NF-κB and potentiate apoptosis in oral cancer cells.

Pharmacotherapy options in pulmonary alveolar proteinosis

INTRODUCTION

Pulmonary alveolar proteinosis (PAP) is a heterogeneous group of rare diseases characterized by the abnormal production and impaired degradation of pulmonary surfactant as a result of malfunctioning of alveolar macrophages. This is due to the downstream dysregulation of the GM-CSF pathway, which can be caused by specific autoantibodies (autoimmune, aPAP formerly known as idiopathic iPAP), direct injury to alveolar macrophages (e.g. by toxic inhaled agents.), or by genetic defects (hereditary or congenital PAP). Few pharmacotherapy options are currently available to treat this disease.

AREA COVERED

The authors discuss the exogenous administration of GM-CSF, rituximab, and the potential role of cholesterol lowering medications in this review. The authors, furthermore, provide their opinion on the available pharmacotherapeutic options and give their future perspectives.

EXPERT OPINION

Inhaled GM-CSF remains the most commonly used therapy in patients with iPAP but other inhaled therapies such as PPARγ activators should be considered, especially in patients who are partially responsive or unresponsive to traditional treatments.

Pioglitazone, Nuclear Receptors, and Aerodigestive Prevention

There has been intense interest in nuclear receptor targeting for cancer prevention. With the exception of estrogen antagonism in breast carcinoma there has not been widespread adoption or success of this strategy in clinical cancer prevention. Keith and colleagues have performed a careful study, which utilized the PPARγ nuclear receptor agonist, pioglitazone, a common type II diabetes agent, in subjects at risk for lung carcinoma. Although the results are not promising with this strategy, the study provides evidence for feasibility accrual and biomarker strategies that could be utilized to gain additional insight in future trials.

Chemoprevention of Lung Carcinogenesis by Dietary Nicotinamide and Inhaled Budesonide

Nicotinamide, the amide form of vitamin B3, and budesonide, a synthetic glucocorticoid used in the treatment of asthma, were evaluated to determine their individual and combinational chemopreventive efficacy on benzo(a)pyrene-induced lung tumors in female A/J mice. Nicotinamide fed at a dietary concentration of 0.75% significantly inhibited tumor multiplicity. Nicotinamide by aerosol inhalation at doses up to 15 mg/kg/day did not result in a statistically significant reduction in tumor multiplicity. Finally, dietary nicotinamide was administered with aerosol budesonide and tumor multiplicity reduced by 90% at 1 week and 49% at 8 weeks post last carcinogen dose. We conclude nicotinamide is an effective and safe agent for lung cancer dietary prevention at both early- and late-stage carcinogenesis and that efficacy is increased with aerosol budesonide. Combination chemoprevention with these agents is a well-tolerated and effective strategy which could be clinically advanced to human studies.

The potential to treat lung cancer via inhalation of repurposed drugs

Lung cancer is a highly invasive and prevalent disease with ineffective first-line treatment and remains the leading cause of cancer death in men and women. Despite the improvements in diagnosis and therapy, the prognosis and outcome of lung cancer patients is still poor. This could be associated with the lack of effective first-line oncology drugs, formation of resistant tumors and non-optimal administration route. Therefore, the repurposing of existing drugs currently used for different indications and the introduction of a different method of drug administration could be investigated as an alternative to improve lung cancer therapy. This review describes the rationale and development of repositioning of drugs for lung cancer treatment with emphasis on inhalation. The review includes the current progress of repurposing non-cancer drugs, as well as current chemotherapeutics for lung malignancies via inhalation. Several potential non-cancer drugs such as statins, itraconazole and clarithromycin, that have demonstrated preclinical anti-cancer activity, are also presented. Furthermore, the potential challenges and limitations that might hamper the clinical translation of repurposed oncology drugs are described.

PPARγ-Mediated p21 Induction in Aerodigestive Preneoplastic Cell Lines

INTRODUCTION

Oral leukoplakia is defined as a mucous membrane disorder characterized by white patches that cannot be scraped off. Leukoplakia is the most frequent, potentially premalignant oral mucosa disorder and a good candidate for chemopreventive therapies. Pioglitazone activates peroxisome proliferator-activated receptor gamma (PPARγ), which forms a complex with nuclear cofactors and regulates gene expression of a variety of cell-cycle proteins and is currently being tested preclinically and clinically in aerodigestive cancer prevention.

METHODS

In the present study, we hypothesized that pioglitazone would decrease proliferation of human leukoplakia cells (MSK Leuk1) and transformed bronchial epithelial cells (BEAS-2B) through regulatory changes of G1 checkpoint protein regulators, p21 and cyclin-D1. MSK Leuk1 and BEAS-2B cells were treated with pioglitazone and assayed for cell proliferation and p21 transcriptional activity.

RESULTS

We discovered pioglitazone significantly inhibited cell proliferation in a dose-dependent fashion. We also observed p21 protein induction after treatment with pioglitazone, which was preceded by measurable increases in p21 mRNA induction.

CONCLUSIONS

We conclude the PPARγ activator, pioglitazone, can activate p21, which is associated with decreased proliferation in 2 aerodigestive preneoplastic cell lines. In addition, the p21 gene may be a potential hypothesis-driven biomarker in translational studies of pioglitazone as a chemoprevention agent for aerodigestive cancer.

Pioglitazone ameliorates retinal ischemia/reperfusion injury via suppressing NLRP3 inflammasome activities

AIM

To explore the role of Pioglitazone (Pio) on a mouse model of retinal ischemia/reperfusion (I/R) injury and to elucidate the potential mechanism.

METHODS

Retinal ischemia was induced in mice by increasing the intraocular pressure, and Pio was administered 4h though periocular injection before I/R. The number of cells in the ganglion cell layer (GCL) was counted 7d after retinal I/R injury. Glial fibrillary acidic protein (GFAP), nuclear factor-kappa B (NF-κB), p38, phosphorylated-p38, PPAR-γ, interleukin-1β (IL-1β), Toll-like receptor 4 (TLR4), NLRP3, cleaved caspase-1, caspase-1 were determined by real-time polymerase chain reaction and Western blotting.

RESULTS

Pio promoted the survival of retinal cells in GCL following retinal I/R injury (P<0.05). Besides, retinal I/R injury stimulated the expression of GFAP and TLR4, which were partially reversed by Pio treatment (P<0.05). Retinal I/R injury-upregulated expression of NLRP3, cleaved caspase-1, IL-1β was attenuated after Pio treatment (P<0.05). Moreover, I/R injury induced activation of NF-κB and p38 were inhibited by Pio treatment (P<0.05).

CONCLUSION

Pio promotes retinal ganglion cells survival by suppressing I/R-induced activation of TLR4/NLRP3 inflammasomes via inhibiting NF-κB and p38 phosphorylation.

Pioglitazone-mediated reversal of elevated glucose metabolism in the airway epithelium of mouse lung adenocarcinomas

Airway epithelial cells are prone to the damage caused by lung cancer risk factors, such as cigarette smoking. Little is known about surrogate biomarkers in the bronchial airway epithelium that can be used to assess the effect of potential chemoprevention drugs on lung adenocarcinoma formation/progression. Pioglitazone has been suggested as a chemoprevention drug for lung cancer. To study the mechanisms underlying the role of pioglitazone in lung cancer prevention, we performed transcriptome sequencing (RNA-Seq) and found that Kras signaling was repressed by pioglitazone treatment in the airway epithelial cells of mice with lung adenocarcinoma (FDR q = 9.8E-04). It was also found that glucose metabolic pathways were elevated in the airway epithelium of mice with lung adenocarcinomas and inhibited by pioglitazone treatment (FDR q = 0.01). Downregulation of glucose metabolism genes was also observed in lung tumors of mice treated with pioglitazone. The high-risk expression signature of elevated glucose metabolism was associated with poor survival outcome in multiple lung adenocarcinoma patient populations (P values ranging from 1.0E-9 to 5.5E-5). Our results suggest that the role of pioglitazone in preventing lung adenocarcinoma may depend on inhibiting Kras signaling and glucose metabolism, which may serve as biomarkers of agent action in the airway epithelium.