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Targeted inhibition of FAK, PYK2 and BCL-XL synergistically enhances apoptosis in ovarian clear cell carcinoma cell lines.

Yoon H, Choi YL, Song JY, Do I, Kang SY, Ko YH, Song S, Kim BG - PLoS ONE (2014)

Bottom Line: We then searched for single agents that exhibited a synergistic effect on cell death in combination with PF271.We found that co-treatment of PF271 with ABT-737, a BCL-2/BCL-XL antagonist, was profoundly effective at inducing apoptosis.Mechanistically, PF271 treatment resulted in the transient down-regulation of the anti-apoptotic protein MCL1 via the PI3K/AKT pathway.

View Article: PubMed Central - PubMed

Affiliation: Institute for Refractory Cancer Research, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

ABSTRACT
Ovarian clear cell carcinoma (OCCC) displays a higher resistance to first line chemotherapy, requiring the development of new therapeutics. We previously identified a frequent chromosomal gain at 8q24 that harbors the focal-adhesion kinase (FAK) gene; the potential of this gene as a therapeutic target remains to be evaluated in OCCCs. We first examined the dependence of OCCCs on FAK and the PI3K/AKT signaling pathway. FAK was overexpressed in 20% of 67 OCCC samples, and this overexpression was correlated with its copy number gain. FAK copy number gains and mutations in PIK3CA accounted for about 40% of OCCC samples, suggesting that the FAK/PI3K/AKT axis is an attractive candidate for targeted therapeutics. We, therefore, treated ovarian cancer cell lines, including OCCC subtypes, with the FAK inhibitors PF-562,271 (PF271), and PF-573,228 (PF228). Ovarian cancer cells were more sensitive to PF271 than PF228. We then searched for single agents that exhibited a synergistic effect on cell death in combination with PF271. We found that co-treatment of PF271 with ABT-737, a BCL-2/BCL-XL antagonist, was profoundly effective at inducing apoptosis. RMGI and OVISE cells were more sensitive to ABT-737 than OVMANA and SKOV3 cells, which have PIK3CA mutations. Mechanistically, PF271 treatment resulted in the transient down-regulation of the anti-apoptotic protein MCL1 via the PI3K/AKT pathway. Therefore, PF271/ABT-737 treatment led to the inhibition of the anti-apoptotic proteins MCL1 and BCL-XL/BCL-2. We suggest that pharmacological inhibition of BCL-XL and FAK/PYK2 can be a potential therapeutic strategy for the treatment of OCCC.

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Synergistic effect of the FAK and BCL2/BCL-XL inhibitors in triggering cell death.A, Cell proliferation assays were performed 72-737 (□: A), BEZ235 (○: B), PF271 (△: P), ABT-737 combined with 1 µM BEZ235 (▪: AB), ABT-737 combined with 5 µM PF271 (•: AP), and ABT-737 combined with 1 µM BEZ235 and 5 µM PF271 (▴: ABP) for 72 hr. Cell viability (%) was calculated and dose response curves were predicted with a four-parameter log-logistic function. B, OVMANA, RMGI, TOV21G, and OVISE cells were exposed to ABT-737 (0.2 or 1 µM), BEZ235 (0.2 or 1 µM), or PF271 (1, or 5 µM) individually or in combinations for 24 hr. The values of cytotoxicity (%) indicate the percentage of dead cells for each treatment. The cytotoxicity data represented in B are the means ± SD from a single representative of three experiments. A synergistic effect was observed when the cells were treated with both ABT-737 and PF271.
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pone-0088587-g004: Synergistic effect of the FAK and BCL2/BCL-XL inhibitors in triggering cell death.A, Cell proliferation assays were performed 72-737 (□: A), BEZ235 (○: B), PF271 (△: P), ABT-737 combined with 1 µM BEZ235 (▪: AB), ABT-737 combined with 5 µM PF271 (•: AP), and ABT-737 combined with 1 µM BEZ235 and 5 µM PF271 (▴: ABP) for 72 hr. Cell viability (%) was calculated and dose response curves were predicted with a four-parameter log-logistic function. B, OVMANA, RMGI, TOV21G, and OVISE cells were exposed to ABT-737 (0.2 or 1 µM), BEZ235 (0.2 or 1 µM), or PF271 (1, or 5 µM) individually or in combinations for 24 hr. The values of cytotoxicity (%) indicate the percentage of dead cells for each treatment. The cytotoxicity data represented in B are the means ± SD from a single representative of three experiments. A synergistic effect was observed when the cells were treated with both ABT-737 and PF271.

Mentions: To further evaluate the effects of combining PF271 and ABT-737, ovarian cancer cell lines were treated with PF271, ABT-737, and BEZ235 alone or in combination of either PF271 (5 µM), BEZ235 (1 µM), or PF271 (5 µM)/BEZ235 (1 µM) and increasing doses of ABT-737, and dose-response curves were determined. In particular, RMGI cells were relatively sensitive to ABT-737 alone, but were resistant to BEZ235 as compared to OVMANA cells (Fig. 4A). As shown in Fig. 3, treatment with PF271 and ABT-737 lowered the EC50 by more than 6-10-fold in RMGI and OVMANA cells (Fig. 4A). In the RMGI cell line, the combination of PF271 and ABT-737 further lowered the EC50 as compared with the combination of BEZ235 and ABT-737 (Fig. 4A).


Targeted inhibition of FAK, PYK2 and BCL-XL synergistically enhances apoptosis in ovarian clear cell carcinoma cell lines.

Yoon H, Choi YL, Song JY, Do I, Kang SY, Ko YH, Song S, Kim BG - PLoS ONE (2014)

Synergistic effect of the FAK and BCL2/BCL-XL inhibitors in triggering cell death.A, Cell proliferation assays were performed 72-737 (□: A), BEZ235 (○: B), PF271 (△: P), ABT-737 combined with 1 µM BEZ235 (▪: AB), ABT-737 combined with 5 µM PF271 (•: AP), and ABT-737 combined with 1 µM BEZ235 and 5 µM PF271 (▴: ABP) for 72 hr. Cell viability (%) was calculated and dose response curves were predicted with a four-parameter log-logistic function. B, OVMANA, RMGI, TOV21G, and OVISE cells were exposed to ABT-737 (0.2 or 1 µM), BEZ235 (0.2 or 1 µM), or PF271 (1, or 5 µM) individually or in combinations for 24 hr. The values of cytotoxicity (%) indicate the percentage of dead cells for each treatment. The cytotoxicity data represented in B are the means ± SD from a single representative of three experiments. A synergistic effect was observed when the cells were treated with both ABT-737 and PF271.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921183&req=5

pone-0088587-g004: Synergistic effect of the FAK and BCL2/BCL-XL inhibitors in triggering cell death.A, Cell proliferation assays were performed 72-737 (□: A), BEZ235 (○: B), PF271 (△: P), ABT-737 combined with 1 µM BEZ235 (▪: AB), ABT-737 combined with 5 µM PF271 (•: AP), and ABT-737 combined with 1 µM BEZ235 and 5 µM PF271 (▴: ABP) for 72 hr. Cell viability (%) was calculated and dose response curves were predicted with a four-parameter log-logistic function. B, OVMANA, RMGI, TOV21G, and OVISE cells were exposed to ABT-737 (0.2 or 1 µM), BEZ235 (0.2 or 1 µM), or PF271 (1, or 5 µM) individually or in combinations for 24 hr. The values of cytotoxicity (%) indicate the percentage of dead cells for each treatment. The cytotoxicity data represented in B are the means ± SD from a single representative of three experiments. A synergistic effect was observed when the cells were treated with both ABT-737 and PF271.
Mentions: To further evaluate the effects of combining PF271 and ABT-737, ovarian cancer cell lines were treated with PF271, ABT-737, and BEZ235 alone or in combination of either PF271 (5 µM), BEZ235 (1 µM), or PF271 (5 µM)/BEZ235 (1 µM) and increasing doses of ABT-737, and dose-response curves were determined. In particular, RMGI cells were relatively sensitive to ABT-737 alone, but were resistant to BEZ235 as compared to OVMANA cells (Fig. 4A). As shown in Fig. 3, treatment with PF271 and ABT-737 lowered the EC50 by more than 6-10-fold in RMGI and OVMANA cells (Fig. 4A). In the RMGI cell line, the combination of PF271 and ABT-737 further lowered the EC50 as compared with the combination of BEZ235 and ABT-737 (Fig. 4A).

Bottom Line: We then searched for single agents that exhibited a synergistic effect on cell death in combination with PF271.We found that co-treatment of PF271 with ABT-737, a BCL-2/BCL-XL antagonist, was profoundly effective at inducing apoptosis.Mechanistically, PF271 treatment resulted in the transient down-regulation of the anti-apoptotic protein MCL1 via the PI3K/AKT pathway.

View Article: PubMed Central - PubMed

Affiliation: Institute for Refractory Cancer Research, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

ABSTRACT
Ovarian clear cell carcinoma (OCCC) displays a higher resistance to first line chemotherapy, requiring the development of new therapeutics. We previously identified a frequent chromosomal gain at 8q24 that harbors the focal-adhesion kinase (FAK) gene; the potential of this gene as a therapeutic target remains to be evaluated in OCCCs. We first examined the dependence of OCCCs on FAK and the PI3K/AKT signaling pathway. FAK was overexpressed in 20% of 67 OCCC samples, and this overexpression was correlated with its copy number gain. FAK copy number gains and mutations in PIK3CA accounted for about 40% of OCCC samples, suggesting that the FAK/PI3K/AKT axis is an attractive candidate for targeted therapeutics. We, therefore, treated ovarian cancer cell lines, including OCCC subtypes, with the FAK inhibitors PF-562,271 (PF271), and PF-573,228 (PF228). Ovarian cancer cells were more sensitive to PF271 than PF228. We then searched for single agents that exhibited a synergistic effect on cell death in combination with PF271. We found that co-treatment of PF271 with ABT-737, a BCL-2/BCL-XL antagonist, was profoundly effective at inducing apoptosis. RMGI and OVISE cells were more sensitive to ABT-737 than OVMANA and SKOV3 cells, which have PIK3CA mutations. Mechanistically, PF271 treatment resulted in the transient down-regulation of the anti-apoptotic protein MCL1 via the PI3K/AKT pathway. Therefore, PF271/ABT-737 treatment led to the inhibition of the anti-apoptotic proteins MCL1 and BCL-XL/BCL-2. We suggest that pharmacological inhibition of BCL-XL and FAK/PYK2 can be a potential therapeutic strategy for the treatment of OCCC.

Show MeSH
Related in: MedlinePlus