Local anesthetic levobupivacaine inhibits stemness of osteosarcoma cells by epigenetically repressing MAFB though reducing KAT5 expression

MG149 suppresses anaplastic thyroid cancer progression by inhibition of lysine acetyltransferase KAT5-mediated c-Myc acetylation

BACKGROUND

Anaplastic thyroid cancer (ATC) is a highly lethal form of thyroid cancer. lysine acetyltransferase 5 (KAT5) has been found to promote ATC development via c-Myc stabilization by previous study. We thus designed experiments to confirm the anti-tumor effect of a KAT5 inhibitor (MG149) in ATC.

METHODS

Western blotting assessed the level of KAT5, c-Myc, and epithelial-mesenchymal transition (EMT)-related proteins in ATC cells and xenograft tumor tissues. Cell counting kit-8, flow cytometry, wound healing, and transwell assays revealed the effect of MG149 on cell proliferation, apoptosis, migration, and invasion in ATC cell lines. Immunofluorescence detected the level of E-cadherin and N-cadherin in ATC cell lines. The effect of MG149 on KAT5-mediated c-Myc stabilization was detected using co-immunoprecipitation assay. Tumor volume and tumor weight in ATC xenograft models were evaluated. H&E staining showed the effect of MG149 on lung metastasis in vivo. We further investigated whether MG149 can enhance the sensitivity of ATC to cisplatin (CDDP).

RESULTS

MG149 inhibited cell proliferation and increased the apoptosis of cells. MG149 suppressed the migratory and invasive ability of ATC cells. The EMT in CAL-62 and 8505C cells was significantly inhibited by MG149. MG149 suppressed the KAT5-mediated c-Myc acetylation. MG149 inhibited tumor growth and lung metastasis in vivo. Additionally, MG149 potentiated the sensitivity to CDDP in ATC cells in vitro and in vivo.

CONCLUSION

MG149 suppresses ATC progression and metastasis by inhibiting the acetylation of c-Myc mediated by KAT5.

Self-Renewal and Pluripotency in Osteosarcoma Stem Cells' Chemoresistance: Notch, Hedgehog, and Wnt/β-Catenin Interplay with Embryonic Markers

Osteosarcoma is a highly malignant bone tumor derived from mesenchymal cells that contains self-renewing cancer stem cells (CSCs), which are responsible for tumor progression and chemotherapy resistance. Understanding the signaling pathways that regulate CSC self-renewal and survival is crucial for developing effective therapies. The Notch, Hedgehog, and Wnt/β-Catenin developmental pathways, which are essential for self-renewal and differentiation of normal stem cells, have been identified as important regulators of osteosarcoma CSCs and also in the resistance to anticancer therapies. Targeting these pathways and their interactions with embryonic markers and the tumor microenvironment may be a promising therapeutic strategy to overcome chemoresistance and improve the prognosis for osteosarcoma patients. This review focuses on the role of Notch, Hedgehog, and Wnt/β-Catenin signaling in regulating CSC self-renewal, pluripotency, and chemoresistance, and their potential as targets for anti-cancer therapies. We also discuss the relevance of embryonic markers, including SOX-2, Oct-4, NANOG, and KLF4, in osteosarcoma CSCs and their association with the aforementioned signaling pathways in overcoming drug resistance.

Repurposed Drugs in Gastric Cancer

Gastric cancer (GC) is one of the major causes of death worldwide, ranking as the fifth most incident cancer in 2020 and the fourth leading cause of cancer mortality. The majority of GC patients are in an advanced stage at the time of diagnosis, presenting a poor prognosis and outcome. Current GC treatment approaches involve endoscopic detection, gastrectomy and chemotherapy or chemoradiotherapy in an adjuvant or neoadjuvant setting. Drug development approaches demand extreme effort to identify molecular mechanisms of action of new drug candidates. Drug repurposing is based on the research of new therapeutic indications of drugs approved for other pathologies. In this review, we explore GC and the different drugs repurposed for this disease.

Impact of local anesthetics on epigenetics in cancer

Defective silencing of tumor suppressor genes through epigenetic alterations contributes to oncogenesis by perturbing cell cycle regulation, DNA repair or cell death mechanisms. Reversal of such epigenetic changes including DNA hypermethylation provides a promising anticancer strategy. Until now, the nucleoside derivatives 5-azacytidine and decitabine are the sole DNA methyltransferase (DNMT) inhibitors approved by the FDA for the treatment of specific hematological cancers. Nevertheless, due to their nucleoside structure, these inhibitors directly incorporate into DNA, which leads to severe side effects and compromises genomic stability. Much emphasis has been placed on the development of less toxic epigenetic modifiers. Recently, several preclinical studies demonstrated the potent epigenetic effects of local anesthetics, which are routinely used during primary tumor resection to relief surgical pain. These non-nucleoside molecules inhibit DNMT activity, affect the expression of micro-RNAs and repress histone acetylation, thus exerting cytotoxic effects on malignant cells. The in-depth mechanistic comprehension of these epigenetic effects might promote the use of local anesthetics as anticancer drugs.