Anticancer Potential of Aguerin B, a Sesquiterpene Lactone Isolated from Centaurea behen in Metastatic Breast Cancer Cells

Sesquiterpene Lactones as Promising Candidates for Cancer Therapy: Focus on Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease which confers to patients a poor prognosis at short term. PDAC is the fourth leading cause of death among cancers in the Western world. The rate of new cases of pancreatic cancer (incidence) is 10 per 100,000 but present a 5-year survival of less than 10%, highlighting the poor prognosis of this pathology. Furthermore, 90% of advanced PDAC tumor present KRAS mutations impacting in several oncogenic signaling pathways, many of them associated with cell proliferation and tumor progression. Different combinations of chemotherapeutic agents have been tested over the years without an improvement of significance in its treatment. PDAC remains as one the more challenging biomedical topics thus far. The lack of a proper early diagnosis, the notable mortality statistics and the poor outcome with the available therapies urge the entire scientific community to find novel approaches against PDAC with real improvements in patients' survival and life quality. Natural compounds have played an important role in the process of discovery and development of new drugs. Among them, terpenoids, such as sesquiterpene lactones, stand out due to their biological activities and pharmacological potential as antitumor agents. In this review, we will describe the sesquiterpene lactones with in vitro and in vivo activity against pancreatic tumor cells. We will also discuss the mechanism of action of the compounds as well as the signaling pathways associated with their activity.

Synthesis and anticancer evaluation of sulfur containing 9-anilinoacridines

BACKGROUND

DNA topoisomerases are a class of enzymes that play a critical role in fundamental biological processes of replication, transcription, recombination, repair and chromatin remodeling. Amsacrine (m-AMSA), the best-known compound of 9-anilinoacridines series was one of the first DNA-intercalating agents to be considered as a Topoisomerase II inhibitor.

OBJECTIVE

A series of sulfur containing 9-anilinoacridines related to amsacrine were synthesized and evaluated for their anticancer activity.

METHODS

Cell viability was assessed by the MTT assay. The topoisomerase II inhibitory assay was performed using the Human topoisomerase II Assay kit and flow cytometry was used to evaluate the effects on cell cycle of K562 cells. Molecular docking was performed using Schrödinger Maestro program.

RESULTS

Compound 36 was found to be the most cytotoxic of the sulfide series against SW620, K562, and MCF-7. The limited SAR suggested the importance of the methansulfonamidoacetamide side chain functionality, the lipophilicity and relative metabolic stability of 36 in contributing to the cytotoxicity. Topoisomerase II α inhibitory activity appeared to be involved in the cytotoxicity of 36 through inhibition of decatenation of kinetoplast DNA (kDNA) in a concentration dependent manner. Cell cycle analysis further showed the Topo II inhibition through accumulation of K562 cells in G2/M phase of cell cycle. Docking of 36 into the Topo II α-DNA complex suggested that it may be an allosteric inhibitor of Topo II α.

CONCLUSION

Compound 36 exhibits anticancer activity by inhibiting topoisomerase II and it could further be evaluated in in vivo models.