Natural products are important leads in drug discovery. The search for effective plant‐derived anticancer agents or their synthetic analogues has continued to be of interest to biologists and ...chemists for a long time. In this report, cytotoxicity and anticancer activity of new synthetic α‐methylene‐δ‐lactones was tested against two breast cancer cell lines, invasive, hormone‐independent MDA‐MB‐231 and hormone‐dependent MCF‐7. Cytotoxicity was examined using MTT assay. The ability to induce apoptosis and changes in mitochondrial membrane potential was studied by flow cytometry. The expression levels of pro‐ and anti‐apoptotic genes were determined by quantitative real‐time PCR. Cancer cell migration and invasion were assessed by wound healing and Matrigel assays. Additionally, secretion of proteins associated with invasiveness, metalloproteinase‐9 (MMP‐9) and urokinase plasminogen activator (uPA) was investigated using commercial ELISA kits and MMP‐9 activity by gelatin zymography. A natural sesquiterpene lactone, parthenolide, was used as a positive control. Screening results showed all four analogues to be highly cytotoxic. The most potent compound of the series, 1‐isopropyl‐2‐methylene‐1,2‐dihydrobenzochromen‐3‐one, designated DL‐3, which reduced the number of viable MDA‐MB‐231 and MCF‐7 cells with the IC50 values of 5.3 μM and 3.54 μM, respectively, was selected for further research. DL‐3 activated the intrinsic pathway of apoptosis, associated with the loss of mitochondrial membrane potential and changes in Bax/Bcl‐2 ratio. DL‐3 also inhibited the movement of both types of breast cancer cells. Suppression of cell migration and invasion was the result of the decreased secretion of enzymes responsible for the degradation of the extracellular matrix, MMP‐9 and uPA. These findings show that the synthetic α‐methylene‐δ‐lactone, DL‐3, displays potential to be further explored in the development of new anticancer agents.
Natural products are important leads in drug discovery. The search for effective plant-derived anticancer agents or their synthetic analogues has continued to be of interest to biologists and ...chemists for a long time. In this report, cytotoxicity and anticancer activity of new synthetic alpha-methylene-delta-lactones was tested against two breast cancer cell lines, invasive, hormone-independent MDA-MB-231 and hormone-dependent MCF-7. Cytotoxicity was examined using MTT assay. The ability to induce apoptosis and changes in mitochondrial membrane potential was studied by flow cytometry. The expression levels of pro- and anti-apoptotic genes were determined by quantitative real-time PCR. Cancer cell migration and invasion were assessed by wound healing and Matrigel assays. Additionally, secretion of proteins associated with invasiveness, metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA) was investigated using commercial ELISA kits and MMP-9 activity by gelatin zymography. A natural sesquiterpene lactone, parthenolide, was used as a positive control. Screening results showed all four analogues to be highly cytotoxic. The most potent compound of the series, 1-isopropyl-2-methylene-1,2-dihydrobenzochromen-3-one, designated DL-3, which reduced the number of viable MDA-MB-231 and MCF-7 cells with the IC50 values of 5.3 µM and 3.54 µM, respectively, was selected for further research. DL-3 activated the intrinsic pathway of apoptosis, associated with the loss of mitochondrial membrane potential and changes in Bax/Bcl-2 ratio. DL-3 also inhibited the movement of both types of breast cancer cells. Suppression of cell migration and invasion was the result of the decreased secretion of enzymes responsible for the degradation of the extracellular matrix, MMP-9 and uPA. These findings show that the synthetic alpha-methylene-delta-lactone, DL-3, displays potential to be further explored in the development of new anticancer agents. PUBLICATION ABSTRACT
The biological activities of parthenolide, a sesquiterpene lactone isolated from feverfew, have been attributed to the presence of the alpha -methylene- gamma -lactone skeleton. The lactone skeleton ...can react via the Michael type addition with sulfhydryl groups of enzymes and other functional proteins, interfering with key biological processes in the cell. In the present study, we describe an efficient method of preparation of 3-isopropyl-2-methyl-4-methyleneisoxa zolidin-5-one (MZ-6), a synthetic compound with alpha -methylene- gamma -lactone ring, as in parthenolide, additionally modified by introduction of a nitrogen atom. Furthermore, we investigated the cytotoxic activity and anti-metastatic potential of MZ-6 in comparison with parthenolide. Both compounds showed considerable cytotoxicity against breast cancer MCF-7 and MDA-MB-231 adenocarcinoma cells in vitro and were then evaluated for their anti-metastatic potential. The experimental results showed that MZ-6 and parthenolide suppressed, to a similar degree, migration of MCF-7, but not more aggressive MDA-MB-231 cells. In both cell lines, tested compounds down-regulated mRNA and protein levels of metalloproteinase-9 and urokinase plasminogen activator, the key proteases involved in the degradation of extracellular matrix and dissemination of cancer cells. The obtained results indicate that simple analogs of alpha -methylene- gamma -lactones can be good substitutes for more complex structures isolated from plants. Cytotoxic activity and anti-metastatic potential of parthenolide and MZ-6, a simple analog of parthenolide with the same alpha -methylene- gamma -lactone motif, have been investigated. Efficient synthesis of MZ-6, has been described.
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