Determination of Inhibitory Effect of PKM2 Enzyme and Antitumoral Activity of Novel Coumarin-Naphthoquinone Hybrids.

BACKGROUND: Oral squamous cell carcinoma (OSCC) represents the primary form of oral cancer, posing a significant global health threat. The existing chemotherapy options are accompanied by notable side effects impacting patient treatment adherence. Consequently, the exploration and development of novel substances with enhanced anticancer effects and fewer side effects have become pivotal in the realms of biological and chemical science. OBJECTIVE: This work presents the pioneering examples of naphthoquinone-coumarin hybrids as a new category of highly effective cytotoxic substances targeting oral squamous cell carcinoma (OSCC). METHODS: Given the significance of both naphthoquinones and coumarins as essential pharmacophores/ privileged structures in the quest for anticancer compounds, this study focused on the synthesis and evaluation of novel naphthoquinones/coumarin hybrids against oral squamous cell carcinoma. RESULTS: By several in vitro, in silico, and in vivo approaches, we demonstrated that compound 6e was highly cytotoxic against OSCC cells and several other cancer cell types and was more selective than current chemotherapeutic drugs (carboplatin) and the naphthoquinone lapachol. Furthermore, compound 6e was non-hemolytic and tolerated in vivo at 50 mg/kg with an LD50 of 62.5 mg/kg. Furthermore, compound 6e did not induce apoptosis and cell cycle arrest but led to intracellular vesicle formation with LC3 aggregation in autophagosomes, suggesting an autophagic cell death. Additionally, 6e had a high-affinity potential for PKM2 protein, higher than the known ligands, such as lapachol or shikonin, and was able to inhibit this enzyme activity in vitro. CONCLUSION: We assert that compound 6e shows promise as a potential lead for a novel chemotherapeutic drug targeting OSCC, with potential applicability to other cancer types.

Pyrones isolated from Annona acutiflora exhibit promising cytotoxic effects on cancer cell lines.

This work discusses the ongoing challenge of cancer, focusing on therapy issues such as chemotherapy resistance and adverse drug effects. It emphasizes the need for new anticancer agents with improved efficacy and fewer side effects, exploring natural products from plant sources. The Annonaceae family, specifically the Annona genus, is highlighted for its medicinal properties, including anti-inflammatory and anticancer effects. The study focuses on the isolation and elucidation of the substances present in Annona acutiflora leaves. The methodology involves chromatographic and spectroscopy techniques. The isolated compounds, (6S)-5'-oxohepten-1'E,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (1), (6R)-5'-oxohepten-1'Z,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (2) and (6R)-5'-oxohepten-1'Z,3'E-dienyl)-5,6-dihydro-2H-pyran-2-one (3) were investigated for cytotoxicity assays on cancer cell lines and normal cells. Results show promising cytotoxic activity, particularly with compound 3, demonstrating potential activity against oral cancer (43.18µM), hepatocarcinoma (17.24µM), melanoma (5.39µM), and colon cancer (59.03µM). The compound outperforms carboplatin in selectivity against oral cancer (S.I. 2.15) and melanoma (S.I. 17.22). The study concludes by suggesting the potential of these α-pyrones as effective and less toxic alternatives for cancer therapy.

Drug Resistance and Novel Targets for Cancer Therapy: An Overview of Recent Findings.

The complex nature of cancer cells poses a challenge to the scientific community [...].

A Novel MDM2-Binding Chalcone Induces Apoptosis of Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) represents ~90% of all oral cancers, being the eighth most common cancer in men. The overall 5-year survival rate is only 39% for metastatic cancers, and currently used chemotherapeutics can cause important side effects. Thus, there is an urgency in developing new and effective anti-cancer agents. As both chalcones and 1,2,3-triazoles are valuable pharmacophores/privileged structures in the search for anticancer compounds, in this work, new 1,2,3-triazole-chalcone hybrids were synthesized and evaluated against oral squamous cell carcinoma. By using different in silico, in vitro, and in vivo approaches, we demonstrated that compound 1f has great cytotoxicity and selectivity against OSCC (higher than carboplatin and doxorubicin) and other cancer cells in addition to showing minimal toxicity in mice. Furthermore, we demonstrate that induced cell death occurs by apoptosis and cell cycle arrest at the G2/M phase. Moreover, we found that 1f has a potential affinity for MDM2 protein, similar to the known ligand nutlin-3, and presents a better selectivity, pharmacological profile, and potential to be orally absorbed and is not a substrate of Pg-P when compared to nutlin-3. Therefore, we conclude that 1f is a good lead for a new chemotherapeutic drug against OSCC and possibly other types of cancers.

Pro-Apoptotic Antitumoral Effect of Novel Acridine-Core Naphthoquinone Compounds against Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is a global public health problem with high incidence and mortality. The chemotherapeutic agents used in the clinic, alone or in combination, usually lead to important side effects. Thus, the discovery and development of new antineoplastic drugs are essential to improve disease prognosis and reduce toxicity. In the present study, acridine-core naphthoquinone compounds were synthesized and evaluated for their antitumor activity in OSCC cells. The mechanism of action, pharmacokinetics, and toxicity parameters of the most promising compound was further analyzed using in silico, in vitro, and in vivo methods. Among the derivatives, compound 4e was highly cytotoxic (29.99 µM) and selective (SI 2.9) at levels comparable and generally superior to chemotherapeutic controls. Besides, compound 4e proved to be non-hemolytic, stable, and well tolerated in animals at all doses tested. Mechanistically, compound 4e promoted cell death by apoptosis in the OSCC cell, and molecular docking studies suggested this compound possibly targets enzymes important for tumor progression, such as RSK2, PKM2, and topoisomerase IIα. Importantly, compound 4e presented a pharmacological profile within desirable parameters for drug development, showing promise for future preclinical trials.