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Positron emission tomographic monitoring of dual phosphatidylinositol-3-kinase and mTOR inhibition in anaplastic large cell lymphoma.

Graf N, Li Z, Herrmann K, Weh D, Aichler M, Slawska J, Walch A, Peschel C, Schwaiger M, Buck AK, Dechow T, Keller U - Onco Targets Ther (2014)

Bottom Line: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling.Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.

View Article: PubMed Central - PubMed

Affiliation: III Medical Department, Technische Universität München, Munich, Germany.

ABSTRACT

Background: Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and the thymidine analog, 3'-deoxy-3'-[(18)F] fluorothymidine (FLT).

Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.

Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.

Conclusion: Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.

No MeSH data available.


Related in: MedlinePlus

FLT-PET and FDG-PET imaging for response prediction in vivo allows early detection of refractory disease in Karpas299 xenografts. Treatment with BGT226 7.5 mg/kg (n=9) or placebo (n=7) started when tumors reached a volume of approximately 300 mm3 (day 0). Mice received BGT226 or placebo for 4 consecutive days followed by a 3-day intermission after which therapy was resumed. Some mice were sacrificed on day 7 to explant lymphomas for immunohistochemical analysis (therapy group, n=5; control group, n=3) and the remaining animals were monitored for tumor growth until day 14. (A) Tumor growth measurements. In this setting, either FLT-PET ([B] therapy group, n=5; control, n=3) or FDG-PET ([C] therapy group, n=4; control group, n=4) was performed on days 0 and 7. Left: representative PET scans showing change in tumor tracer uptake (arrows). Right: TBR was calculated and served as an indicator of tracer uptake. TBR on day 0 was defined as 100%. Change in TBR compared with pretreatment values is shown for treated (BGT226) and control animals. (D) Immunohistochemistry of explanted lymphomas using the apoptosis marker, cleaved caspase-3, and the proliferation marker, Ki-67. Mean values ± standard deviation are shown.Abbreviations: PET, positron emission tomography; FDG, 2-deoxy-2-[18F]fluoro-D-glucose; FLT, 3′-deoxy-3′-[18F]fluorothymidine; TBR, tumor-to-background ratio; pos, positive.
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f4-ott-7-789: FLT-PET and FDG-PET imaging for response prediction in vivo allows early detection of refractory disease in Karpas299 xenografts. Treatment with BGT226 7.5 mg/kg (n=9) or placebo (n=7) started when tumors reached a volume of approximately 300 mm3 (day 0). Mice received BGT226 or placebo for 4 consecutive days followed by a 3-day intermission after which therapy was resumed. Some mice were sacrificed on day 7 to explant lymphomas for immunohistochemical analysis (therapy group, n=5; control group, n=3) and the remaining animals were monitored for tumor growth until day 14. (A) Tumor growth measurements. In this setting, either FLT-PET ([B] therapy group, n=5; control, n=3) or FDG-PET ([C] therapy group, n=4; control group, n=4) was performed on days 0 and 7. Left: representative PET scans showing change in tumor tracer uptake (arrows). Right: TBR was calculated and served as an indicator of tracer uptake. TBR on day 0 was defined as 100%. Change in TBR compared with pretreatment values is shown for treated (BGT226) and control animals. (D) Immunohistochemistry of explanted lymphomas using the apoptosis marker, cleaved caspase-3, and the proliferation marker, Ki-67. Mean values ± standard deviation are shown.Abbreviations: PET, positron emission tomography; FDG, 2-deoxy-2-[18F]fluoro-D-glucose; FLT, 3′-deoxy-3′-[18F]fluorothymidine; TBR, tumor-to-background ratio; pos, positive.

Mentions: SU-DHL-1 tumors treated with BGT226 showed a marked reduction in growth and only a modest increase in tumor volume until day 7 (n=10, mean 2.0-fold increase, standard deviation [SD] 0.22) followed by stabilization until day 14 (n=5; mean 2.1-fold increase, SD 0.20), whereas vehicle-treated control animals showed rapid growth of lymphomas on day 7 (n=7, mean 6.1-fold increase, SD 0.16) and day 14 (n=3; mean 11.6-fold increase, SD 0.17; P<0.001, Figure 3A). In contrast, Karpas299 cells gave rise to lymphomas that were mainly resistant to BGT226 (n=4, mean 5.3-fold increase, SD 0.21) resulting in a tumor volume on day 14 similar to that of control tumors (n=4, mean 6.2-fold increase, SD 0.40; P=0.08, Figure 4A).


Positron emission tomographic monitoring of dual phosphatidylinositol-3-kinase and mTOR inhibition in anaplastic large cell lymphoma.

Graf N, Li Z, Herrmann K, Weh D, Aichler M, Slawska J, Walch A, Peschel C, Schwaiger M, Buck AK, Dechow T, Keller U - Onco Targets Ther (2014)

FLT-PET and FDG-PET imaging for response prediction in vivo allows early detection of refractory disease in Karpas299 xenografts. Treatment with BGT226 7.5 mg/kg (n=9) or placebo (n=7) started when tumors reached a volume of approximately 300 mm3 (day 0). Mice received BGT226 or placebo for 4 consecutive days followed by a 3-day intermission after which therapy was resumed. Some mice were sacrificed on day 7 to explant lymphomas for immunohistochemical analysis (therapy group, n=5; control group, n=3) and the remaining animals were monitored for tumor growth until day 14. (A) Tumor growth measurements. In this setting, either FLT-PET ([B] therapy group, n=5; control, n=3) or FDG-PET ([C] therapy group, n=4; control group, n=4) was performed on days 0 and 7. Left: representative PET scans showing change in tumor tracer uptake (arrows). Right: TBR was calculated and served as an indicator of tracer uptake. TBR on day 0 was defined as 100%. Change in TBR compared with pretreatment values is shown for treated (BGT226) and control animals. (D) Immunohistochemistry of explanted lymphomas using the apoptosis marker, cleaved caspase-3, and the proliferation marker, Ki-67. Mean values ± standard deviation are shown.Abbreviations: PET, positron emission tomography; FDG, 2-deoxy-2-[18F]fluoro-D-glucose; FLT, 3′-deoxy-3′-[18F]fluorothymidine; TBR, tumor-to-background ratio; pos, positive.
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f4-ott-7-789: FLT-PET and FDG-PET imaging for response prediction in vivo allows early detection of refractory disease in Karpas299 xenografts. Treatment with BGT226 7.5 mg/kg (n=9) or placebo (n=7) started when tumors reached a volume of approximately 300 mm3 (day 0). Mice received BGT226 or placebo for 4 consecutive days followed by a 3-day intermission after which therapy was resumed. Some mice were sacrificed on day 7 to explant lymphomas for immunohistochemical analysis (therapy group, n=5; control group, n=3) and the remaining animals were monitored for tumor growth until day 14. (A) Tumor growth measurements. In this setting, either FLT-PET ([B] therapy group, n=5; control, n=3) or FDG-PET ([C] therapy group, n=4; control group, n=4) was performed on days 0 and 7. Left: representative PET scans showing change in tumor tracer uptake (arrows). Right: TBR was calculated and served as an indicator of tracer uptake. TBR on day 0 was defined as 100%. Change in TBR compared with pretreatment values is shown for treated (BGT226) and control animals. (D) Immunohistochemistry of explanted lymphomas using the apoptosis marker, cleaved caspase-3, and the proliferation marker, Ki-67. Mean values ± standard deviation are shown.Abbreviations: PET, positron emission tomography; FDG, 2-deoxy-2-[18F]fluoro-D-glucose; FLT, 3′-deoxy-3′-[18F]fluorothymidine; TBR, tumor-to-background ratio; pos, positive.
Mentions: SU-DHL-1 tumors treated with BGT226 showed a marked reduction in growth and only a modest increase in tumor volume until day 7 (n=10, mean 2.0-fold increase, standard deviation [SD] 0.22) followed by stabilization until day 14 (n=5; mean 2.1-fold increase, SD 0.20), whereas vehicle-treated control animals showed rapid growth of lymphomas on day 7 (n=7, mean 6.1-fold increase, SD 0.16) and day 14 (n=3; mean 11.6-fold increase, SD 0.17; P<0.001, Figure 3A). In contrast, Karpas299 cells gave rise to lymphomas that were mainly resistant to BGT226 (n=4, mean 5.3-fold increase, SD 0.21) resulting in a tumor volume on day 14 similar to that of control tumors (n=4, mean 6.2-fold increase, SD 0.40; P=0.08, Figure 4A).

Bottom Line: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling.Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.

View Article: PubMed Central - PubMed

Affiliation: III Medical Department, Technische Universität München, Munich, Germany.

ABSTRACT

Background: Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and the thymidine analog, 3'-deoxy-3'-[(18)F] fluorothymidine (FLT).

Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.

Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.

Conclusion: Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.

No MeSH data available.


Related in: MedlinePlus