Novel bladder-sparing approaches in patients with muscle-invasive bladder cancer

The pursuit of surgeons and oncologists in fulfilling the inherent desire of patients to retain their urinary bladder despite having muscle-invasive bladder cancer (MIBC) has sparked years of research and multiple debates, given its aggressive nature and the high risk of fatal metastatic recurrence. Historically, several approaches to bladder-sparing treatment have been explored, ranging from radical transurethral resection to concurrent chemoradiation. A less well-established approach involves a risk-adapted approach with local therapy deferred based on the clinical response to transurethral resection followed by systemic therapy. Each approach is associated with potential risks, benefits, and trade-offs. In this review, we aim to understand, navigate, and suggest future perspectives on bladder-sparing approaches in patients with MIBC.

Dietary Melatonin and Glycine Decrease Tumor Growth through Antiangiogenic Activity in Experimental Colorectal Liver Metastasis

Despite multimodal treatment strategies, clinical outcomes of advanced stage colorectal cancer (CRC) patients remain poor. Neoadjuvant/adjuvant chemotherapy efficacy is limited due to chemoresistance, toxicity, and negative side effects. Since both melatonin and glycine have anti-cancer activities without relevant side effects, this study was designed to investigate their combined effects in experimental CRC liver metastases. CRC metastasis with CC531 cells were induced in male Wistar rats. Melatonin and glycine alone or their combination were supplemented for 14 days (n = 100). Blood parameters, a micro-computed tomography scan (tumor volume over time), and immunohistochemistry for Ki67 and CD31 expression in tumor tissue were compared between groups. Melatonin and glycine alone significantly reduced the tumor volume by 63.2% (p = 0.002) and 43% (p = 0.044) over time, respectively, while tumor volume increased by 8.7% in the controls. Moreover, treatment with melatonin and glycine alone reduced the tumor proliferation index. Most interestingly, the combination therapy did not have any influence on the above-mentioned tumor parameters. The leukocyte count was significantly increased with melatonin at the end of the experiment (p = 0.012) which was due to a high lymphocytes count. Tumor microvascular density was significantly reduced in all treatment groups. The results of this study suggest an inhibitory function for melatonin and glycine alone in the case of CRC liver metastasis growth by acting as natural antiangiogenic molecules, followed by angiogenesis-dependent cancer proliferation and immunomodulation.

Combination of Salinomycin and AZD3463 Reveals Synergistic Effect on Reducing the Viability of T98G Glioblastoma Cells

BACKGROUND

Salinomycin, an ionophore antibiotic, is known to be an effective agent in reducing the viability of Glioblastoma (GBM) cells. The combination of salinomycin with other chemotherapeutic drugs would help to overcome the drug resistance of GBM cells.

OBJECTIVE

This study aims to test the combinatorial effect of salinomycin and AZD3463 in T98G GBM cells.

METHODS

The cytotoxic effects of drugs on T98G GBM cells were determined by using WST-8 assay. Flow cytometry was used to identify apoptosis and cell cycle profiles after treatments. Real-time PCR was used to portray mRNA expression profiles of genes in the Wnt-signaling pathway after treatments.

RESULTS

IC50 concentrations of AZD3463 and salinomycin were 529nM and 7.3μM for 48h, respectively. The combination concentrations of AZD3463 and salinomycin were 3.3μM and 333nM, respectively. The combination treatment showed a synergistic effect on reducing the viability of GBM cells. AZD3463, salinomycin, and their combination induced apoptosis in 1.2, 1.4, and 3.2 folds, respectively. AZD3463 and the combination treatment induced the cell cycle arrest at the G1 phase. Salinomycin and AZD3463 treatments, either alone or in combination, resulted in the downregulation or upregulation of mRNA expression levels of genes in the Wntsignaling pathway.

CONCLUSION

Salinomycin, AZD3463, and their combination may inhibit proliferation and induce apoptosis in GBM cells due to a decrease in expression levels of genes acting in both the canonical and non-canonical Wnt signaling pathways. The Wnt signaling pathway may be involved in salinomycin-AZD3463 drug interaction.

The Antimalarial Drug Pyronaridine Inhibits Topoisomerase II in Breast Cancer Cells and Hinders Tumor Progression In Vivo

BACKGROUND

Breast cancer is the most frequently diagnosed cancer in women worldwide. Pyronaridine (PND), an antimalarial drug, was shown to exert anticancer activity on seventeen different human cancer cells, seven from female breast tissue. Additionally, PND induced apoptosis via mitochondrial depolarization, alteration of cell cycle progression, and DNA intercalation. However, the molecular target of PND in cells was not elucidated.

OBJECTIVE

Here, we have further investigated PND's mode of action by using transcriptome analysis. Preclinical studies were also performed to determine whether PND could affect tumor progression in a human breast cancer xenograft in mice. Moreover, we assessed the combined efficacy of PND with well-known anticancer drugs.

METHODS

Transcriptome analyses of PND-treated cancer cells were performed. Topoisomerase II activity was evaluated by an in vitro assay. In addition, daily oral administration of PND was given to mice with human breast cancer xenografts. The differential nuclear staining assay measured in-vitro cell toxicity.

RESULTS

The transcriptome signatures suggested that PND might act as a topoisomerase II inhibitor. Thus, topoisomerase inhibition assays were performed, providing evidence that PND is a bona fide topoisomerase II inhibitor. Also, in-vivo studies suggest that PND hinders tumor progression. Besides, combination studies of PND with anticancer drugs cisplatin and gemcitabine revealed higher cytotoxicity against cancer cells than individual drug administration.

CONCLUSION

The findings provide evidence that PND is a topoisomerase II inhibitor and can hinder cancer progression in an animal model, further demonstrating PND's favorable characteristics as a repurposed anticancer drug.

Synergistic AML Cell Death Induction by Marine Cytotoxin (+)-1(R), 6(S), 1'(R), 6'(S), 11(R), 17(S)-Fistularin-3 and Bcl-2 Inhibitor Venetoclax

Treatment of acute myeloid leukemia (AML) patients is still hindered by resistance and relapse, resulting in an overall poor survival rate. Recently, combining specific B-cell lymphoma (Bcl)-2 inhibitors with compounds downregulating myeloid cell leukemia (Mcl)-1 has been proposed as a new effective strategy to eradicate resistant AML cells. We show here that 1(R), 6(S), 1’(R), 6’(S), 11(R), 17(S)-fistularin-3, a bromotyrosine compound of the fistularin family, isolated from the marine sponge Suberea clavata, synergizes with Bcl-2 inhibitor ABT-199 to efficiently kill Mcl-1/Bcl-2-positive AML cell lines, associated with Mcl-1 downregulation and endoplasmic reticulum stress induction. The absolute configuration of carbons 11 and 17 of the fistularin-3 stereoisomer was fully resolved in this study for the first time, showing that the fistularin we isolated from the marine sponge Subarea clavata is in fact the (+)-11(R), 17(S)-fistularin-3 stereoisomer keeping the known configuration 1(R), 6(S), 1’(R), and 6’(S) for the verongidoic acid part. Docking studies and in vitro assays confirm the potential of this family of molecules to inhibit DNA methyltransferase 1 activity.