Limits...
Dimethylaminoparthenolide and gemcitabine: a survival study using a genetically engineered mouse model of pancreatic cancer.

Yip-Schneider MT, Wu H, Stantz K, Agaram N, Crooks PA, Schmidt CM - BMC Cancer (2013)

Bottom Line: Gemcitabine or the combination DMAPT/gemcitabine significantly increased median survival and decreased the incidence and multiplicity of pancreatic adenocarcinomas.The DMAPT/gemcitabine combination also significantly decreased tumor size and the incidence of metastasis to the liver.While gemcitabine treatment increased the levels of the inflammatory cytokines interleukin 1α (IL-1α), IL-1β, and IL-17 in mouse plasma, DMAPT and DMAPT/gemcitabine reduced the levels of the inflammatory cytokines IL-12p40, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 beta (MIP-1β), eotaxin, and tumor necrosis factor-alpha (TNF-α), all of which are NF-κB target genes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Surgery, Indiana University School of Medicine, 980 W. Walnut St,, Building R3, Rm. 541C, Indianapolis, IN 46202, USA. myipschn@iupui.edu

ABSTRACT

Background: Pancreatic cancer remains one of the deadliest cancers due to lack of early detection and absence of effective treatments. Gemcitabine, the current standard-of-care chemotherapy for pancreatic cancer, has limited clinical benefit. Treatment of pancreatic cancer cells with gemcitabine has been shown to induce the activity of the transcription factor nuclear factor-kappaB (NF-κB) which regulates the expression of genes involved in the inflammatory response and tumorigenesis. It has therefore been proposed that gemcitabine-induced NF-κB activation may result in chemoresistance. We hypothesize that NF-κB suppression by the novel inhibitor dimethylaminoparthenolide (DMAPT) may enhance the effect of gemcitabine in pancreatic cancer.

Methods: The efficacy of DMAPT and gemcitabine was evaluated in a chemoprevention trial using the mutant Kras and p53-expressing LSL-KrasG12D/+; LSL-Trp53R172H; Pdx-1-Cre mouse model of pancreatic cancer. Mice were randomized to treatment groups (placebo, DMAPT [40 mg/kg/day], gemcitabine [50 mg/kg twice weekly], and the combination DMAPT/gemcitabine). Treatment was continued until mice showed signs of ill health at which time they were sacrificed. Plasma cytokine levels were determined using a Bio-Plex immunoassay. Statistical tests used included log-rank test, ANOVA with Dunnett's post-test, Student's t-test, and Fisher exact test.

Results: Gemcitabine or the combination DMAPT/gemcitabine significantly increased median survival and decreased the incidence and multiplicity of pancreatic adenocarcinomas. The DMAPT/gemcitabine combination also significantly decreased tumor size and the incidence of metastasis to the liver. No significant differences in the percentages of normal pancreatic ducts or premalignant pancreatic lesions were observed between the treatment groups. Pancreata in which no tumors formed were analyzed to determine the extent of pre-neoplasia; mostly normal ducts or low grade pancreatic lesions were observed, suggesting prevention of higher grade lesions in these animals. While gemcitabine treatment increased the levels of the inflammatory cytokines interleukin 1α (IL-1α), IL-1β, and IL-17 in mouse plasma, DMAPT and DMAPT/gemcitabine reduced the levels of the inflammatory cytokines IL-12p40, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 beta (MIP-1β), eotaxin, and tumor necrosis factor-alpha (TNF-α), all of which are NF-κB target genes.

Conclusion: In summary, these findings provide preclinical evidence supporting further evaluation of agents such as DMAPT and gemcitabine for the prevention and treatment of pancreatic cancer.

Show MeSH

Related in: MedlinePlus

Luciferase-expressing p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice. A) At 10 and 13 weeks of age, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were injected with D-luciferin (60 mg/kg; i.p.) and imaged to detect bioluminescence as shown for three representative mice. At each time point, a sequence of 15 images (2 minutes exposure time/image) was acquired. The image with the peak bioluminescence was used to assess relative change in photon fluence rate, e.g., counts/min in each voxel, using a lower threshold of 150 counts/min/sec (> 10 times background noise). The optical geometry was identical for all imaging sessions. B) Total photon flux (counts/min/tumor x 106) at 10 and 13 weeks of age (n = 14 mice). * P < 0.05 by two-tailed paired t-test. C) Median survival for each treatment group is shown in the Kaplan-Meier survival curve (placebo = 126 days; DMAPT = 143 days; Gem = 155 days). * P < 0.05 for gemcitabine vs. placebo by log-rank test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3672012&req=5

Figure 2: Luciferase-expressing p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice. A) At 10 and 13 weeks of age, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were injected with D-luciferin (60 mg/kg; i.p.) and imaged to detect bioluminescence as shown for three representative mice. At each time point, a sequence of 15 images (2 minutes exposure time/image) was acquired. The image with the peak bioluminescence was used to assess relative change in photon fluence rate, e.g., counts/min in each voxel, using a lower threshold of 150 counts/min/sec (> 10 times background noise). The optical geometry was identical for all imaging sessions. B) Total photon flux (counts/min/tumor x 106) at 10 and 13 weeks of age (n = 14 mice). * P < 0.05 by two-tailed paired t-test. C) Median survival for each treatment group is shown in the Kaplan-Meier survival curve (placebo = 126 days; DMAPT = 143 days; Gem = 155 days). * P < 0.05 for gemcitabine vs. placebo by log-rank test.

Mentions: A pilot study was also performed with a related model suitable for imaging, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice, in which p53 is deleted and mutant Kras and luciferase are expressed in the pancreas. The p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were imaged at 10 weeks of age to monitor luciferase expression and detect bioluminescence (Figure 2A). All mice expressed luciferase as shown in the three representative mice, confirming the functional expression of Cre recombinase in the pancreas by 10 weeks of age; bioluminescence was also detected at 6 weeks of age, the earliest timepoint at which the animals were imaged. Three weeks after the initial imaging, the same mice were re-imaged; increased bioluminescence and therefore luciferase expression were detected, that should reflect a corresponding increase in mutant Kras expression and p53 deletion in the pancreas at 13 weeks of age. Total photon flux significantly increased between 10 and 13 weeks for the majority of the mice (Figure 2B). Using this model to test the single agents, gemcitabine was administered at 8 weeks of age and significantly increased median survival by approximately 30 days compared to placebo (155 days vs. 126 days [P = 0.02]), thus confirming gemcitabine’s beneficial effect (Figure 2C). DMAPT did not significantly extend survival (143 days [P = 0.14]).


Dimethylaminoparthenolide and gemcitabine: a survival study using a genetically engineered mouse model of pancreatic cancer.

Yip-Schneider MT, Wu H, Stantz K, Agaram N, Crooks PA, Schmidt CM - BMC Cancer (2013)

Luciferase-expressing p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice. A) At 10 and 13 weeks of age, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were injected with D-luciferin (60 mg/kg; i.p.) and imaged to detect bioluminescence as shown for three representative mice. At each time point, a sequence of 15 images (2 minutes exposure time/image) was acquired. The image with the peak bioluminescence was used to assess relative change in photon fluence rate, e.g., counts/min in each voxel, using a lower threshold of 150 counts/min/sec (> 10 times background noise). The optical geometry was identical for all imaging sessions. B) Total photon flux (counts/min/tumor x 106) at 10 and 13 weeks of age (n = 14 mice). * P < 0.05 by two-tailed paired t-test. C) Median survival for each treatment group is shown in the Kaplan-Meier survival curve (placebo = 126 days; DMAPT = 143 days; Gem = 155 days). * P < 0.05 for gemcitabine vs. placebo by log-rank test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672012&req=5

Figure 2: Luciferase-expressing p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice. A) At 10 and 13 weeks of age, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were injected with D-luciferin (60 mg/kg; i.p.) and imaged to detect bioluminescence as shown for three representative mice. At each time point, a sequence of 15 images (2 minutes exposure time/image) was acquired. The image with the peak bioluminescence was used to assess relative change in photon fluence rate, e.g., counts/min in each voxel, using a lower threshold of 150 counts/min/sec (> 10 times background noise). The optical geometry was identical for all imaging sessions. B) Total photon flux (counts/min/tumor x 106) at 10 and 13 weeks of age (n = 14 mice). * P < 0.05 by two-tailed paired t-test. C) Median survival for each treatment group is shown in the Kaplan-Meier survival curve (placebo = 126 days; DMAPT = 143 days; Gem = 155 days). * P < 0.05 for gemcitabine vs. placebo by log-rank test.
Mentions: A pilot study was also performed with a related model suitable for imaging, p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice, in which p53 is deleted and mutant Kras and luciferase are expressed in the pancreas. The p53f/f; LSL-KrasG12D;lucl/l; Pdx-1-Cre mice were imaged at 10 weeks of age to monitor luciferase expression and detect bioluminescence (Figure 2A). All mice expressed luciferase as shown in the three representative mice, confirming the functional expression of Cre recombinase in the pancreas by 10 weeks of age; bioluminescence was also detected at 6 weeks of age, the earliest timepoint at which the animals were imaged. Three weeks after the initial imaging, the same mice were re-imaged; increased bioluminescence and therefore luciferase expression were detected, that should reflect a corresponding increase in mutant Kras expression and p53 deletion in the pancreas at 13 weeks of age. Total photon flux significantly increased between 10 and 13 weeks for the majority of the mice (Figure 2B). Using this model to test the single agents, gemcitabine was administered at 8 weeks of age and significantly increased median survival by approximately 30 days compared to placebo (155 days vs. 126 days [P = 0.02]), thus confirming gemcitabine’s beneficial effect (Figure 2C). DMAPT did not significantly extend survival (143 days [P = 0.14]).

Bottom Line: Gemcitabine or the combination DMAPT/gemcitabine significantly increased median survival and decreased the incidence and multiplicity of pancreatic adenocarcinomas.The DMAPT/gemcitabine combination also significantly decreased tumor size and the incidence of metastasis to the liver.While gemcitabine treatment increased the levels of the inflammatory cytokines interleukin 1α (IL-1α), IL-1β, and IL-17 in mouse plasma, DMAPT and DMAPT/gemcitabine reduced the levels of the inflammatory cytokines IL-12p40, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 beta (MIP-1β), eotaxin, and tumor necrosis factor-alpha (TNF-α), all of which are NF-κB target genes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Surgery, Indiana University School of Medicine, 980 W. Walnut St,, Building R3, Rm. 541C, Indianapolis, IN 46202, USA. myipschn@iupui.edu

ABSTRACT

Background: Pancreatic cancer remains one of the deadliest cancers due to lack of early detection and absence of effective treatments. Gemcitabine, the current standard-of-care chemotherapy for pancreatic cancer, has limited clinical benefit. Treatment of pancreatic cancer cells with gemcitabine has been shown to induce the activity of the transcription factor nuclear factor-kappaB (NF-κB) which regulates the expression of genes involved in the inflammatory response and tumorigenesis. It has therefore been proposed that gemcitabine-induced NF-κB activation may result in chemoresistance. We hypothesize that NF-κB suppression by the novel inhibitor dimethylaminoparthenolide (DMAPT) may enhance the effect of gemcitabine in pancreatic cancer.

Methods: The efficacy of DMAPT and gemcitabine was evaluated in a chemoprevention trial using the mutant Kras and p53-expressing LSL-KrasG12D/+; LSL-Trp53R172H; Pdx-1-Cre mouse model of pancreatic cancer. Mice were randomized to treatment groups (placebo, DMAPT [40 mg/kg/day], gemcitabine [50 mg/kg twice weekly], and the combination DMAPT/gemcitabine). Treatment was continued until mice showed signs of ill health at which time they were sacrificed. Plasma cytokine levels were determined using a Bio-Plex immunoassay. Statistical tests used included log-rank test, ANOVA with Dunnett's post-test, Student's t-test, and Fisher exact test.

Results: Gemcitabine or the combination DMAPT/gemcitabine significantly increased median survival and decreased the incidence and multiplicity of pancreatic adenocarcinomas. The DMAPT/gemcitabine combination also significantly decreased tumor size and the incidence of metastasis to the liver. No significant differences in the percentages of normal pancreatic ducts or premalignant pancreatic lesions were observed between the treatment groups. Pancreata in which no tumors formed were analyzed to determine the extent of pre-neoplasia; mostly normal ducts or low grade pancreatic lesions were observed, suggesting prevention of higher grade lesions in these animals. While gemcitabine treatment increased the levels of the inflammatory cytokines interleukin 1α (IL-1α), IL-1β, and IL-17 in mouse plasma, DMAPT and DMAPT/gemcitabine reduced the levels of the inflammatory cytokines IL-12p40, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 beta (MIP-1β), eotaxin, and tumor necrosis factor-alpha (TNF-α), all of which are NF-κB target genes.

Conclusion: In summary, these findings provide preclinical evidence supporting further evaluation of agents such as DMAPT and gemcitabine for the prevention and treatment of pancreatic cancer.

Show MeSH
Related in: MedlinePlus