Limits...
Inhibition of cancer cell proliferation and apoptosis-inducing activity of fungal taxol and its precursor baccatin III purified from endophytic Fusarium solani.

Chakravarthi BV, Sujay R, Kuriakose GC, Karande AA, Jayabaskaran C - Cancer Cell Int. (2013)

Bottom Line: They also induced apoptosis in JR4-Jurkat cells with a possible involvement of anti-apoptotic Bcl2 and loss in mitochondrial membrane potential, and was unaffected by inhibitors of caspase-9,-2 or -3 but was prevented in presence of caspase-10 inhibitor.DNA fragmentation was also observed in cells treated with fungal taxol and baccatin III.The cytotoxic activity exhibited by fungal taxol and baccatin III involves the same mechanism, dependent on caspase-10 and membrane potential loss of mitochondria, with taxol having far greater cytotoxic potential.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India. cjb@biochem.iisc.ernet.in.

ABSTRACT

Background: Taxol (generic name paclitaxel), a plant-derived antineoplastic agent, used widely against breast, ovarian and lung cancer, was originally isolated from the bark of the Pacific yew, Taxus brevifolia. The limited supply of the drug has prompted efforts to find alternative sources, such as chemical synthesis, tissue and cell cultures of the Taxus species both of which are expensive and yield low levels. Fermentation processes with microorganisms would be the methods of choice to lower the costs and increase yields. Previously we have reported that F. solani isolated from T. celebica produced taxol and its precursor baccatin III in liquid grown cultures J Biosci 33:259-67, 2008. This study was performed to evaluate the inhibition of proliferation and induction of apoptosis of cancer cell lines by the fungal taxol and fungal baccatin III of F. solani isolated from T. celebica.

Methods: Cell lines such as HeLa, HepG2, Jurkat, Ovcar3 and T47D were cultured individually and treated with fungal taxol, baccatin III with or without caspase inhibitors according to experimental requirements. Their efficacy on apoptotic induction was examined.

Results: Both fungal taxol and baccatin III inhibited cell proliferation of a number of cancer cell lines with IC50 ranging from 0.005 to 0.2 μM for fungal taxol and 2 to 5 μM for fungal baccatin III. They also induced apoptosis in JR4-Jurkat cells with a possible involvement of anti-apoptotic Bcl2 and loss in mitochondrial membrane potential, and was unaffected by inhibitors of caspase-9,-2 or -3 but was prevented in presence of caspase-10 inhibitor. DNA fragmentation was also observed in cells treated with fungal taxol and baccatin III.

Conclusions: The cytotoxic activity exhibited by fungal taxol and baccatin III involves the same mechanism, dependent on caspase-10 and membrane potential loss of mitochondria, with taxol having far greater cytotoxic potential.

No MeSH data available.


Related in: MedlinePlus

Taxol- and baccatin III-induced apoptosis in Jurkat cells assayed with PI staining followed by flow cytometry. Cells (0.25 × 106) were treated with indicated concentrations of taxol or baccatin III for 48 h, and analyzed by PI staining followed by flow cytometry to determine the hypodiploid DNA (fragmented DNA) proportions. 1 × 105 cells were analyzed. The percentage of hypodiploid cells (sub G1 peak) was calculated on the basis of the respective histograms. UT, Untreated cells; DMSO, Dimethylsulfoxide; TSTD, standard taxol; TFUNG, fungal taxol; BSTD, standard baccatin III; BFUNG, fungal baccatin III.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4016216&req=5

Figure 1: Taxol- and baccatin III-induced apoptosis in Jurkat cells assayed with PI staining followed by flow cytometry. Cells (0.25 × 106) were treated with indicated concentrations of taxol or baccatin III for 48 h, and analyzed by PI staining followed by flow cytometry to determine the hypodiploid DNA (fragmented DNA) proportions. 1 × 105 cells were analyzed. The percentage of hypodiploid cells (sub G1 peak) was calculated on the basis of the respective histograms. UT, Untreated cells; DMSO, Dimethylsulfoxide; TSTD, standard taxol; TFUNG, fungal taxol; BSTD, standard baccatin III; BFUNG, fungal baccatin III.

Mentions: Interference of the mitotic spindle apparatus by microtubule-stabilizing drugs would be expected to have an effect on the cell cycle distribution. To determine whether taxol and its precursor would have any such effect, JR4-Jurkat cells were treated for 48 h with 0.1 μM fungal taxol and 3.5 μM baccatin III, subjected to PI staining and the DNA content of the cells measured by flow cytometry. Flow cytometry analysis showed that while untreated and vehicle (DMSO) treated Jurkat cells were predominantly in the G1 phase of the cell cycle (Figure 1), significant changes were observed with fungal taxol and baccatin III-treated cells. Upon treatment, the percentage of G1 and G2/M cells decreased and the percentage of sub G1 cells increased considerably (Figure 1), suggesting initiation of apoptosis process in the cells.


Inhibition of cancer cell proliferation and apoptosis-inducing activity of fungal taxol and its precursor baccatin III purified from endophytic Fusarium solani.

Chakravarthi BV, Sujay R, Kuriakose GC, Karande AA, Jayabaskaran C - Cancer Cell Int. (2013)

Taxol- and baccatin III-induced apoptosis in Jurkat cells assayed with PI staining followed by flow cytometry. Cells (0.25 × 106) were treated with indicated concentrations of taxol or baccatin III for 48 h, and analyzed by PI staining followed by flow cytometry to determine the hypodiploid DNA (fragmented DNA) proportions. 1 × 105 cells were analyzed. The percentage of hypodiploid cells (sub G1 peak) was calculated on the basis of the respective histograms. UT, Untreated cells; DMSO, Dimethylsulfoxide; TSTD, standard taxol; TFUNG, fungal taxol; BSTD, standard baccatin III; BFUNG, fungal baccatin III.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016216&req=5

Figure 1: Taxol- and baccatin III-induced apoptosis in Jurkat cells assayed with PI staining followed by flow cytometry. Cells (0.25 × 106) were treated with indicated concentrations of taxol or baccatin III for 48 h, and analyzed by PI staining followed by flow cytometry to determine the hypodiploid DNA (fragmented DNA) proportions. 1 × 105 cells were analyzed. The percentage of hypodiploid cells (sub G1 peak) was calculated on the basis of the respective histograms. UT, Untreated cells; DMSO, Dimethylsulfoxide; TSTD, standard taxol; TFUNG, fungal taxol; BSTD, standard baccatin III; BFUNG, fungal baccatin III.
Mentions: Interference of the mitotic spindle apparatus by microtubule-stabilizing drugs would be expected to have an effect on the cell cycle distribution. To determine whether taxol and its precursor would have any such effect, JR4-Jurkat cells were treated for 48 h with 0.1 μM fungal taxol and 3.5 μM baccatin III, subjected to PI staining and the DNA content of the cells measured by flow cytometry. Flow cytometry analysis showed that while untreated and vehicle (DMSO) treated Jurkat cells were predominantly in the G1 phase of the cell cycle (Figure 1), significant changes were observed with fungal taxol and baccatin III-treated cells. Upon treatment, the percentage of G1 and G2/M cells decreased and the percentage of sub G1 cells increased considerably (Figure 1), suggesting initiation of apoptosis process in the cells.

Bottom Line: They also induced apoptosis in JR4-Jurkat cells with a possible involvement of anti-apoptotic Bcl2 and loss in mitochondrial membrane potential, and was unaffected by inhibitors of caspase-9,-2 or -3 but was prevented in presence of caspase-10 inhibitor.DNA fragmentation was also observed in cells treated with fungal taxol and baccatin III.The cytotoxic activity exhibited by fungal taxol and baccatin III involves the same mechanism, dependent on caspase-10 and membrane potential loss of mitochondria, with taxol having far greater cytotoxic potential.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India. cjb@biochem.iisc.ernet.in.

ABSTRACT

Background: Taxol (generic name paclitaxel), a plant-derived antineoplastic agent, used widely against breast, ovarian and lung cancer, was originally isolated from the bark of the Pacific yew, Taxus brevifolia. The limited supply of the drug has prompted efforts to find alternative sources, such as chemical synthesis, tissue and cell cultures of the Taxus species both of which are expensive and yield low levels. Fermentation processes with microorganisms would be the methods of choice to lower the costs and increase yields. Previously we have reported that F. solani isolated from T. celebica produced taxol and its precursor baccatin III in liquid grown cultures J Biosci 33:259-67, 2008. This study was performed to evaluate the inhibition of proliferation and induction of apoptosis of cancer cell lines by the fungal taxol and fungal baccatin III of F. solani isolated from T. celebica.

Methods: Cell lines such as HeLa, HepG2, Jurkat, Ovcar3 and T47D were cultured individually and treated with fungal taxol, baccatin III with or without caspase inhibitors according to experimental requirements. Their efficacy on apoptotic induction was examined.

Results: Both fungal taxol and baccatin III inhibited cell proliferation of a number of cancer cell lines with IC50 ranging from 0.005 to 0.2 μM for fungal taxol and 2 to 5 μM for fungal baccatin III. They also induced apoptosis in JR4-Jurkat cells with a possible involvement of anti-apoptotic Bcl2 and loss in mitochondrial membrane potential, and was unaffected by inhibitors of caspase-9,-2 or -3 but was prevented in presence of caspase-10 inhibitor. DNA fragmentation was also observed in cells treated with fungal taxol and baccatin III.

Conclusions: The cytotoxic activity exhibited by fungal taxol and baccatin III involves the same mechanism, dependent on caspase-10 and membrane potential loss of mitochondria, with taxol having far greater cytotoxic potential.

No MeSH data available.


Related in: MedlinePlus