Limits...
KSP inhibitor ARRY-520 as a substitute for Paclitaxel in Type I ovarian cancer cells.

Kim KH, Xie Y, Tytler EM, Woessner R, Mor G, Alvero AB - J Transl Med (2009)

Bottom Line: ARRY-520 and Paclitaxel exhibited the same cytotoxic effect on Type I and II cells.Unlike Paclitaxel, ARRY-520 did not induce NF-kappaB activation, did not enhance cytokine secretion, nor induce ERK phosphorylation in Type I EOC cells.However, unlike Paclitaxel, it does not induce these pro-tumor effects in Type I cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA. ghkim@pusan.ac.kr

ABSTRACT

Background: We previously described a sub-population of epithelial ovarian cancer (EOC) cells with a functional TLR-4/MyD88/NF-kappaB pathway (Type I EOC cells), which confers the capacity to respond to Paclitaxel, a known TLR-4 ligand, by enhancing NF-kappaB activity and upregulating cytokine secretion - events that are known to promote tumor progression. It is therefore important to distinguish those patients that should not receive Paclitaxel; it is also important to identify alternative chemotherapy options that would benefit this sub-group of patients. The objective of this study is to determine if the KSP inhibitor, ARRY-520, can be a substitute for Paclitaxel in patients with Type I EOC.

Methods: EOC cells isolated from either ascites or tumor tissue were treated with increasing concentrations of ARRY-520 or Paclitaxel and cell viability determined. Activation of the apoptotic pathway was determined using Western blot analysis. Mitochondrial integrity was quantified using JC1 dye. Cytokine profiling was performed from supernatants using xMAP technology. NF-kappaB activity was measured using a Luciferase reporter system. In vivo activity was determined using a subcutaneous xenograft mouse model.

Results: ARRY-520 and Paclitaxel exhibited the same cytotoxic effect on Type I and II cells. The GI50 at 48 h for Type II EOC cells was 0.0015 microM and 0.2 microM for ARRY-520 and Paclitaxel, respectively. For Type I EOC cells, the GI50 at 48 h was > 3 microM and >20 microM for ARRY-520 and Paclitaxel, respectively. Decrease in the number of viable cells was accompanied by mitochondrial depolarization and caspase activation. Unlike Paclitaxel, ARRY-520 did not induce NF-kappaB activation, did not enhance cytokine secretion, nor induce ERK phosphorylation in Type I EOC cells.

Conclusion: Administration of Paclitaxel to patients with high percentage Type I cancer cells could have detrimental effects due to Paclitaxel-induced enhancement of NF-kappaB and ERK activities, and cytokine production (e.g. IL-6), which promote chemoresistance and tumor progression. ARRY-520 has similar anti-tumor activity in EOC cells as that of Paclitaxel. However, unlike Paclitaxel, it does not induce these pro-tumor effects in Type I cells. Therefore, the KSP inhibitor ARRY-520 may represent an alternative to Paclitaxel in this subgroup of EOC patients.

Show MeSH

Related in: MedlinePlus

In vivo activity of ARRY-520 and Paclitaxel. EOC tumors were established s.c. in female nude mice and treatments were given as described in the Materials and Methods section. Tumor size was determined by caliper measurements. (a) A2780 xenograft model and (b) tumors established from a primary culture of EOC cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2719595&req=5

Figure 7: In vivo activity of ARRY-520 and Paclitaxel. EOC tumors were established s.c. in female nude mice and treatments were given as described in the Materials and Methods section. Tumor size was determined by caliper measurements. (a) A2780 xenograft model and (b) tumors established from a primary culture of EOC cells.

Mentions: Our final objective was to determine the activity of ARRY-520 in an EOC mice xenograft model. Thus, we established a subcutaneous (s.c.) model in nude mice using A2780, an established EOC cell line, and R182, a primary culture isolated from patient's ascites (Type II and Type I, respectively). The anti-tumor activitiy of ARRY-520 and Paclitaxel was then determined as described in the Methods section. In this animal model, the results confirmed our in vitro observation that the compounds demonstrate equivalent activity against ovarian cancer cells. Both compounds induced a decrease in tumor kinetics in a dose-dependent manner (Fig. 7a and 7b).


KSP inhibitor ARRY-520 as a substitute for Paclitaxel in Type I ovarian cancer cells.

Kim KH, Xie Y, Tytler EM, Woessner R, Mor G, Alvero AB - J Transl Med (2009)

In vivo activity of ARRY-520 and Paclitaxel. EOC tumors were established s.c. in female nude mice and treatments were given as described in the Materials and Methods section. Tumor size was determined by caliper measurements. (a) A2780 xenograft model and (b) tumors established from a primary culture of EOC cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719595&req=5

Figure 7: In vivo activity of ARRY-520 and Paclitaxel. EOC tumors were established s.c. in female nude mice and treatments were given as described in the Materials and Methods section. Tumor size was determined by caliper measurements. (a) A2780 xenograft model and (b) tumors established from a primary culture of EOC cells.
Mentions: Our final objective was to determine the activity of ARRY-520 in an EOC mice xenograft model. Thus, we established a subcutaneous (s.c.) model in nude mice using A2780, an established EOC cell line, and R182, a primary culture isolated from patient's ascites (Type II and Type I, respectively). The anti-tumor activitiy of ARRY-520 and Paclitaxel was then determined as described in the Methods section. In this animal model, the results confirmed our in vitro observation that the compounds demonstrate equivalent activity against ovarian cancer cells. Both compounds induced a decrease in tumor kinetics in a dose-dependent manner (Fig. 7a and 7b).

Bottom Line: ARRY-520 and Paclitaxel exhibited the same cytotoxic effect on Type I and II cells.Unlike Paclitaxel, ARRY-520 did not induce NF-kappaB activation, did not enhance cytokine secretion, nor induce ERK phosphorylation in Type I EOC cells.However, unlike Paclitaxel, it does not induce these pro-tumor effects in Type I cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA. ghkim@pusan.ac.kr

ABSTRACT

Background: We previously described a sub-population of epithelial ovarian cancer (EOC) cells with a functional TLR-4/MyD88/NF-kappaB pathway (Type I EOC cells), which confers the capacity to respond to Paclitaxel, a known TLR-4 ligand, by enhancing NF-kappaB activity and upregulating cytokine secretion - events that are known to promote tumor progression. It is therefore important to distinguish those patients that should not receive Paclitaxel; it is also important to identify alternative chemotherapy options that would benefit this sub-group of patients. The objective of this study is to determine if the KSP inhibitor, ARRY-520, can be a substitute for Paclitaxel in patients with Type I EOC.

Methods: EOC cells isolated from either ascites or tumor tissue were treated with increasing concentrations of ARRY-520 or Paclitaxel and cell viability determined. Activation of the apoptotic pathway was determined using Western blot analysis. Mitochondrial integrity was quantified using JC1 dye. Cytokine profiling was performed from supernatants using xMAP technology. NF-kappaB activity was measured using a Luciferase reporter system. In vivo activity was determined using a subcutaneous xenograft mouse model.

Results: ARRY-520 and Paclitaxel exhibited the same cytotoxic effect on Type I and II cells. The GI50 at 48 h for Type II EOC cells was 0.0015 microM and 0.2 microM for ARRY-520 and Paclitaxel, respectively. For Type I EOC cells, the GI50 at 48 h was > 3 microM and >20 microM for ARRY-520 and Paclitaxel, respectively. Decrease in the number of viable cells was accompanied by mitochondrial depolarization and caspase activation. Unlike Paclitaxel, ARRY-520 did not induce NF-kappaB activation, did not enhance cytokine secretion, nor induce ERK phosphorylation in Type I EOC cells.

Conclusion: Administration of Paclitaxel to patients with high percentage Type I cancer cells could have detrimental effects due to Paclitaxel-induced enhancement of NF-kappaB and ERK activities, and cytokine production (e.g. IL-6), which promote chemoresistance and tumor progression. ARRY-520 has similar anti-tumor activity in EOC cells as that of Paclitaxel. However, unlike Paclitaxel, it does not induce these pro-tumor effects in Type I cells. Therefore, the KSP inhibitor ARRY-520 may represent an alternative to Paclitaxel in this subgroup of EOC patients.

Show MeSH
Related in: MedlinePlus