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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.

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CD31 and Masson’s Trichrome staining. A) CD31 immunostaining. CD31-positive microvessels (brown) stained as indicated by the black arrowheads (400X magnification). B) Percent CD31-positive intratumoral staining within each treatment group (n = 4-5 mice/group) is shown as the mean +/− SEM. C) Masson’s Trichrome staining to detect the stromal component (blue) is shown (400X magnification). D) Percent collagen staining within each treatment group (n = 5-6 mice/group) is shown as the mean +/− SEM.
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Figure 6: CD31 and Masson’s Trichrome staining. A) CD31 immunostaining. CD31-positive microvessels (brown) stained as indicated by the black arrowheads (400X magnification). B) Percent CD31-positive intratumoral staining within each treatment group (n = 4-5 mice/group) is shown as the mean +/− SEM. C) Masson’s Trichrome staining to detect the stromal component (blue) is shown (400X magnification). D) Percent collagen staining within each treatment group (n = 5-6 mice/group) is shown as the mean +/− SEM.

Mentions: Since the animals in this study were not sacrificed at a set endpoint, optimal evaluation of target inhibition at a defined timepoint after the last drug dose was not possible. Nevertheless, intratumoral NF-κB immunohistochemical staining was quantified (Figure 5A), but no significant difference in NF-κB expression was observed between placebo and the DMAPT treatment groups. Quantification of intratumoral Ki67-positive staining showed a significant decrease in both the gemcitabine and combination groups (Figure 5B), correlating with the observed anti-tumor effects of these agents. Ki67 staining in the PanIN lesions did not differ significantly (data not shown). Pancreatic tissue sections were also stained with a CD31-specific antibody and Masson’s Trichrome to detect changes in intratumoral vasculature or stroma, respectively (Figures 6A & C). Intratumoral CD31 expression was quantified and there was no significant difference between treatment groups (Figure 6B). Similarly, there was no significant difference in the percentage of stroma/collagen as determined by quantification of Masson’s Trichrome staining (Figure 6D).


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)

CD31 and Masson’s Trichrome staining. A) CD31 immunostaining. CD31-positive microvessels (brown) stained as indicated by the black arrowheads (400X magnification). B) Percent CD31-positive intratumoral staining within each treatment group (n = 4-5 mice/group) is shown as the mean +/− SEM. C) Masson’s Trichrome staining to detect the stromal component (blue) is shown (400X magnification). D) Percent collagen staining within each treatment group (n = 5-6 mice/group) is shown as the mean +/− SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: CD31 and Masson’s Trichrome staining. A) CD31 immunostaining. CD31-positive microvessels (brown) stained as indicated by the black arrowheads (400X magnification). B) Percent CD31-positive intratumoral staining within each treatment group (n = 4-5 mice/group) is shown as the mean +/− SEM. C) Masson’s Trichrome staining to detect the stromal component (blue) is shown (400X magnification). D) Percent collagen staining within each treatment group (n = 5-6 mice/group) is shown as the mean +/− SEM.
Mentions: Since the animals in this study were not sacrificed at a set endpoint, optimal evaluation of target inhibition at a defined timepoint after the last drug dose was not possible. Nevertheless, intratumoral NF-κB immunohistochemical staining was quantified (Figure 5A), but no significant difference in NF-κB expression was observed between placebo and the DMAPT treatment groups. Quantification of intratumoral Ki67-positive staining showed a significant decrease in both the gemcitabine and combination groups (Figure 5B), correlating with the observed anti-tumor effects of these agents. Ki67 staining in the PanIN lesions did not differ significantly (data not shown). Pancreatic tissue sections were also stained with a CD31-specific antibody and Masson’s Trichrome to detect changes in intratumoral vasculature or stroma, respectively (Figures 6A & C). Intratumoral CD31 expression was quantified and there was no significant difference between treatment groups (Figure 6B). Similarly, there was no significant difference in the percentage of stroma/collagen as determined by quantification of Masson’s Trichrome staining (Figure 6D).

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