Increase in Anticancer Drug-Induced Toxicity by Fisetin in Lung Adenocarcinoma A549 Spheroid Cells Mediated by the Reduction of Claudin-2 Expression

Overcoming obstacles in three-dimensional cell culture model establishment: Approaches for growing A549 non-small cell lung cancer spheroids using a clinostat system

INTRODUCTION

Non-small cell lung cancer (NSCLC) accounts for 80-85 % of lung cancer cases globally. And the A549 cell line is widely used in pharmacological and toxicity screening. Due to its popularity as a NSCLC model, it was inevitable that three-dimensional (3D) cultures of A549 cells would be established. 3D models increase physiological relevance, and their advanced structure allows researchers to obtain more translatable and reliable results. However, establishing this cell line as a 3D model may come with challenges, like clumping.

METHODS

In this study, A549 spheroids were established using a clinostat-based rotating bioreactor system and were characterised in terms of morphology, planimetry, and viability.

RESULTS

The main challenge faced included continuous aggregation of the spheroids, which constrained growth and development. This challenge was successfully overcome by supplementation with ascorbic acid, foetal bovine serum coating, and minimising handling, and a NSCLC mini-tumour model was established and semi-characterised. The spheroids survived for 25 days and had a significant increase in growth.

CONCLUSION

The A549 spheroid model cultured in a clinostat-based microgravity system was shown to be stable, viable, and suitable to be used in pharmacological and toxicological investigations.

Deciphering the role of claudins in lung cancer

Lung cancer remains a major global health challenge, characterized by aggressive malignancy and poor prognostic outcomes. This review article focuses on the pivotal role of claudins, a family of tight junction proteins, in the pathophysiology of lung cancer. Claudins are integral to maintaining epithelial barrier function and cellular polarity, yet they are intricately involved in the progression and metastasis of lung cancer. The aberrant expression of claudins has been observed across various histological subtypes of lung cancer, indicating their potential as diagnostic and prognostic biomarkers. Specifically, claudins such as claudin-1, -2, -3, -4, and -7 exhibit diverse expression patterns that correlate with tumor aggressiveness, patient survival rates, and response to therapies. Inflammation and cytokine modulation significantly influence claudin expression, affecting tumor microenvironment dynamics and cancer progression. This review also highlights the therapeutic implications of targeting claudins, particularly in cases resistant to conventional treatments. Recent advances in this area suggest that claudin-modulating agents may enhance the efficacy of existing therapies and offer new avenues for targeted interventions. By integrating the latest research, this article aims to provide a comprehensive understanding of claudin's roles in lung cancer and encourages further clinical trials to explore claudin-targeting therapies. This could pave the way for more effective management strategies, improving outcomes for lung cancer patients.

Cubosomal nanoformulation increase invitro dissolution and anticancer activity of Fisetin in A549 lung cancer cells

Aim: To prepare fisetin (FIS) cubosomal nanoformulation to increase aqueous solubility and anticancer activity. Methods: Top-down method using glyceryl monooleate (GMO) and Pluronic F-127. Results: Optimized using 2% GMO and 1% Pluronic F-127, reported 93.07 nm particle size, 80.10% drug entrapment, and reports more than 50% enhanced in vitro drug release than native FIS. MTT assay reports IC50 Values of FIS 16.59 μg/ml and optimized cubosomal FIS nanoformulation (FISCUB) 12.18 μg/ml. The colony numbers observed in clonogenic assay for FISCUB were 8.33 ± 0.58 and FIS 11.67 ± 1.15. In flow cytometry study, apoptotic cells in FISCUB and FIS-treated A549 cells were found to be 33.4 and 6.83% respectively. Conclusion: A stable cubosomal nanoformulation of FIS showed enhanced aqueous solubility and anticancer activity.

A New Saponin (Zygo-albuside D) from Zygophyllum album Roots Triggers Apoptosis in Non-Small Cell Lung Carcinoma (A549 Cells) through CDK-2 Inhibition

Phytochemical study of the ethyl acetate root extract of Zygophyllum album has resulted in the isolation of a new saponin, Zygo-albuside D (1), along with two known compounds; (3-O-[β-D-quinovopyranosyl]-quinovic acid) (2), which is first reported in the root, and catechin (3), first reported in the genus. Their chemical structures were established by NMR and high-resolution mass spectrometry (HRMS). The new saponin (1) exhibited promising cytotoxicity with IC50 values of 3.5 and 5.52 μM on A549 and PC-3 cancer cell lines, respectively, compared to doxorubicin with IC50 values of 9.44 and 11.39 μM on A549 and PC-3 cancer cell lines, respectively. While it had an IC50 value of 46.8 μM against WISH cells. Investigating apoptosis-induction, compound 1 induced total apoptotic cell death in A549 lung cancer cells by 32-fold; 21.53% compared to 0.67% in the untreated control cells. Finally, it upregulated the pro-apoptotic genes and downregulated the antiapoptotic gene using gene expression levels. Compound 1 exhibited remarkable CDK-2 target inhibition by 96.2% with an IC50 value of 117.6 nM compared to Roscovitine. The molecular docking study further confirmed the binding affinity of compound 1 as CDK2 and Bcl2 inhibitors that led to apoptosis induction in A549 cancer cells. Hence, this study highlights the importance of compound 1 in the design of a new anticancer agent with specific mechanisms.

Kaempferol and Fisetin-Related Signaling Pathways Induce Apoptosis in Head and Neck Cancer Cells

Despite the relative effectiveness of standard cancer treatment strategies, head and neck cancer (HNC) is still considered one of the leading causes of mortality and morbidity. While selected bioactive compounds of plant origin reveal a pro-apoptotic effect, kaempferol and fisetin flavonols have been reported as potential anti-cancer agents against malignant neoplasms. To date, their exact role in signaling pathways of head and neck cancer cells is largely unknown. Based on the various methods of cytotoxicity testing, we elucidated that kaempferol and fisetin inhibit proliferation, reduce the capacity of cell migration, and induce apoptosis in SCC-9, SCC-25, and A-253 HNC cells in a dose-dependent manner in vitro (p < 0.05, fisetin IC₅₀ values of 38.85 µM, 62.34 µM, and 49.21 µM, and 45.03 µM, 49.90 µM, and 47.49 µM for kaempferol-SCC-9, SCC-25, and A-253, respectively). The obtained results showed that exposure to kaempferol and fisetin reduces Bcl-2 protein expression, simultaneously leading to the arrest in the G2/M and S phases of the cell cycle. Kaempferol and fisetin inhibit cell proliferation by interfering with the cell cycle, which is strongly associated with the induction of G2/M arrest, and induce apoptosis by activating caspase-3 and releasing cytochrome c in human HNC cells. In addition, investigating flavonols, by inhibiting anti-apoptotic proteins from the Bcl-2 family and damaging the mitochondrial transmembrane potential, increased the level of cytochrome c. While flavonols selectively induce apoptosis of head and neck cancer cells, they may support oncological therapy as promising agents. The discovery of new derivatives may be a breakthrough in the search for effective chemotherapeutic agents with less toxicity and thus fewer side effects.