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Assessment of bystander killing-mediated therapy of malignant brain tumors using a multimodal imaging approach.

Leten C, Trekker J, Struys T, Dresselaers T, Gijsbers R, Vande Velde G, Lambrichts I, Van Der Linden A, Verfaillie CM, Himmelreich U - Stem Cell Res Ther (2015)

Bottom Line: Subsequently, ganciclovir (GCV) treatment was commenced and the fate of both the MAPCs and the tumor were followed by multimodal imaging (MRI and bioluminescence imaging).Noteworthy, in some phosphate-buffered saline-treated animals (33 %), a significant decrease in tumor size was seen compared to sham-operated animals, which could potentially also be caused by a synergistic effect of the immune-modulatory stem cells.This treatment could be followed and guided noninvasively in vivo by MRI and bioluminescence imaging.

View Article: PubMed Central - PubMed

Affiliation: Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000, Leuven, Belgium. cindy.leten@gmail.com.

ABSTRACT

Introduction: In this study, we planned to assess if adult stem cell-based suicide gene therapy can efficiently eliminate glioblastoma cells in vivo. We investigated the therapeutic potential of mouse Oct4(-) bone marrow multipotent adult progenitor cells (mOct4(-) BM-MAPCs) in a mouse glioblastoma model, guided by multimodal in vivo imaging methods to identify therapeutic windows.

Methods: Magnetic resonance imaging (MRI) of animals, wherein 5 × 10(5) syngeneic enhanced green fluorescent protein-firefly luciferase-herpes simplex virus thymidine kinase (eGFP-fLuc-HSV-TK) expressing and superparamagnetic iron oxide nanoparticle labeled (1 % or 10 %) mOct4(-) BM-MAPCs were grafted in glioblastoma (GL261)-bearing animals, showed that labeled mOct4(-) BM-MAPCs were located in and in close proximity to the tumor. Subsequently, ganciclovir (GCV) treatment was commenced and the fate of both the MAPCs and the tumor were followed by multimodal imaging (MRI and bioluminescence imaging).

Results: In the majority of GCV-treated, but not phosphate-buffered saline-treated animals, a significant difference was found in mOct4(-) BM-MAPC viability and tumor size at the end of treatment. Noteworthy, in some phosphate-buffered saline-treated animals (33 %), a significant decrease in tumor size was seen compared to sham-operated animals, which could potentially also be caused by a synergistic effect of the immune-modulatory stem cells.

Conclusions: Suicide gene therapy using mOct4(-) BM-MAPCs as cellular carriers was effective in reducing the tumor size in the majority of the GCV-treated animals leading to a longer progression-free survival compared to sham-operated animals. This treatment could be followed and guided noninvasively in vivo by MRI and bioluminescence imaging. Noninvasive imaging is of particular interest for a rapid and efficient validation of stem cell-based therapeutic approaches for glioblastoma and hereby contributes to a better understanding and optimization of a promising therapeutic approach for glioblastoma patients.

No MeSH data available.


Related in: MedlinePlus

In vivo suicide gene therapy using eGFP-fLuc-HSV-TK (+), ihSPIO-labeled mOct4− BM-MAPCs in a mouse glioblastoma model. a Hypointense signal volume determination (three-dimensional T2* MRI) on 1 % labeled mOct4− BM-MAPCs did not show statistically significant differences between stem cell injected animals (phosphate-buffered saline (PBS)/ganciclovir (GCV)) and sham-operated animals (SHAM) 1 day after surgery (day 16). At the end of treatment (day 30), there was, however, a significant difference between sham-operated animals and GCV-treated animals (**p < 0.01) due to the smaller tumor sizes in the GCV-treated group. In the sham-operated and PBS-treated group, tumor formation was present which is accompanied with necrosis and bleedings when tumors grow over time. In contrast, the hypointense signal in the GCV-treated group, which did not develop tumors, is mostly generated by remaining labeled mOct4− BM-MAPCs. b Hypointense signal volume determination (three-dimensional T2* MRI) on 10 % labeled mOct4− BM-MAPCs showed statistically significant differences between stem cell injected animals (PBS/GCV) and sham-operated animals 1 day after surgery (day 16). At the end of treatment (day 30), there was a statistically significant difference between sham-operated and PBS-treated animals and between the PBS-treated and GCV-treated groups. *p < 0.05, **p < 0.01, ***p < 0.001. c MR images of one representative animal stereotactically injected with 1 % or 10 % labeled mOct4− BM-MAPCs showed that the hypointense contrast, delineated in red, generated by 10 % labeled mOct4− BM-MAPCs was more pronounced compared to 1 % labeled cells. SC stem cell
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Fig3: In vivo suicide gene therapy using eGFP-fLuc-HSV-TK (+), ihSPIO-labeled mOct4− BM-MAPCs in a mouse glioblastoma model. a Hypointense signal volume determination (three-dimensional T2* MRI) on 1 % labeled mOct4− BM-MAPCs did not show statistically significant differences between stem cell injected animals (phosphate-buffered saline (PBS)/ganciclovir (GCV)) and sham-operated animals (SHAM) 1 day after surgery (day 16). At the end of treatment (day 30), there was, however, a significant difference between sham-operated animals and GCV-treated animals (**p < 0.01) due to the smaller tumor sizes in the GCV-treated group. In the sham-operated and PBS-treated group, tumor formation was present which is accompanied with necrosis and bleedings when tumors grow over time. In contrast, the hypointense signal in the GCV-treated group, which did not develop tumors, is mostly generated by remaining labeled mOct4− BM-MAPCs. b Hypointense signal volume determination (three-dimensional T2* MRI) on 10 % labeled mOct4− BM-MAPCs showed statistically significant differences between stem cell injected animals (PBS/GCV) and sham-operated animals 1 day after surgery (day 16). At the end of treatment (day 30), there was a statistically significant difference between sham-operated and PBS-treated animals and between the PBS-treated and GCV-treated groups. *p < 0.05, **p < 0.01, ***p < 0.001. c MR images of one representative animal stereotactically injected with 1 % or 10 % labeled mOct4− BM-MAPCs showed that the hypointense contrast, delineated in red, generated by 10 % labeled mOct4− BM-MAPCs was more pronounced compared to 1 % labeled cells. SC stem cell

Mentions: We have previously shown that HSV-TK containing mOct4− BM-MAPCs can be killed in vitro using GCV concentrations as low as 0.01 μM [26]. Furthermore, we have also shown that mOct4− BM-MAPCs could be killed successfully in vivo following treatment with GCV (14 days, 50 mg/kg) [26]. In this study, we assessed whether administration of GCV to mice with HSV-TK containing mOct4− BM-MAPCs present in and around a glioblastoma (GL261) could also kill the glioblastoma cells via a suicide killing bystander effect [9]. Hereby, it is essential to assess the capacity of eGFP-fLuc-HSV-TK-expressing and ihSPIO-labeled mOct4− BM-MAPCs to distribute within and around the glioblastoma. We have engrafted 5 × 105 mOct4− BM-MAPCs into the mouse brain, of which only a fraction (1 or 10 %) of the injected cells was labeled with ihSPIO particles, as 3 × 105 cells already generated extensive hypointense contrast (Fig. 3). Evaluation of the grafted cells by MRI showed that when 10 % (Fig. 3b), but not 1 % (Fig. 3a) of the stem cells were labeled with ihSPIO particles it was possible to follow them by MRI as indicated by the hypointense signal. One representative animal is shown in Fig. 3c.Fig. 3


Assessment of bystander killing-mediated therapy of malignant brain tumors using a multimodal imaging approach.

Leten C, Trekker J, Struys T, Dresselaers T, Gijsbers R, Vande Velde G, Lambrichts I, Van Der Linden A, Verfaillie CM, Himmelreich U - Stem Cell Res Ther (2015)

In vivo suicide gene therapy using eGFP-fLuc-HSV-TK (+), ihSPIO-labeled mOct4− BM-MAPCs in a mouse glioblastoma model. a Hypointense signal volume determination (three-dimensional T2* MRI) on 1 % labeled mOct4− BM-MAPCs did not show statistically significant differences between stem cell injected animals (phosphate-buffered saline (PBS)/ganciclovir (GCV)) and sham-operated animals (SHAM) 1 day after surgery (day 16). At the end of treatment (day 30), there was, however, a significant difference between sham-operated animals and GCV-treated animals (**p < 0.01) due to the smaller tumor sizes in the GCV-treated group. In the sham-operated and PBS-treated group, tumor formation was present which is accompanied with necrosis and bleedings when tumors grow over time. In contrast, the hypointense signal in the GCV-treated group, which did not develop tumors, is mostly generated by remaining labeled mOct4− BM-MAPCs. b Hypointense signal volume determination (three-dimensional T2* MRI) on 10 % labeled mOct4− BM-MAPCs showed statistically significant differences between stem cell injected animals (PBS/GCV) and sham-operated animals 1 day after surgery (day 16). At the end of treatment (day 30), there was a statistically significant difference between sham-operated and PBS-treated animals and between the PBS-treated and GCV-treated groups. *p < 0.05, **p < 0.01, ***p < 0.001. c MR images of one representative animal stereotactically injected with 1 % or 10 % labeled mOct4− BM-MAPCs showed that the hypointense contrast, delineated in red, generated by 10 % labeled mOct4− BM-MAPCs was more pronounced compared to 1 % labeled cells. SC stem cell
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4562202&req=5

Fig3: In vivo suicide gene therapy using eGFP-fLuc-HSV-TK (+), ihSPIO-labeled mOct4− BM-MAPCs in a mouse glioblastoma model. a Hypointense signal volume determination (three-dimensional T2* MRI) on 1 % labeled mOct4− BM-MAPCs did not show statistically significant differences between stem cell injected animals (phosphate-buffered saline (PBS)/ganciclovir (GCV)) and sham-operated animals (SHAM) 1 day after surgery (day 16). At the end of treatment (day 30), there was, however, a significant difference between sham-operated animals and GCV-treated animals (**p < 0.01) due to the smaller tumor sizes in the GCV-treated group. In the sham-operated and PBS-treated group, tumor formation was present which is accompanied with necrosis and bleedings when tumors grow over time. In contrast, the hypointense signal in the GCV-treated group, which did not develop tumors, is mostly generated by remaining labeled mOct4− BM-MAPCs. b Hypointense signal volume determination (three-dimensional T2* MRI) on 10 % labeled mOct4− BM-MAPCs showed statistically significant differences between stem cell injected animals (PBS/GCV) and sham-operated animals 1 day after surgery (day 16). At the end of treatment (day 30), there was a statistically significant difference between sham-operated and PBS-treated animals and between the PBS-treated and GCV-treated groups. *p < 0.05, **p < 0.01, ***p < 0.001. c MR images of one representative animal stereotactically injected with 1 % or 10 % labeled mOct4− BM-MAPCs showed that the hypointense contrast, delineated in red, generated by 10 % labeled mOct4− BM-MAPCs was more pronounced compared to 1 % labeled cells. SC stem cell
Mentions: We have previously shown that HSV-TK containing mOct4− BM-MAPCs can be killed in vitro using GCV concentrations as low as 0.01 μM [26]. Furthermore, we have also shown that mOct4− BM-MAPCs could be killed successfully in vivo following treatment with GCV (14 days, 50 mg/kg) [26]. In this study, we assessed whether administration of GCV to mice with HSV-TK containing mOct4− BM-MAPCs present in and around a glioblastoma (GL261) could also kill the glioblastoma cells via a suicide killing bystander effect [9]. Hereby, it is essential to assess the capacity of eGFP-fLuc-HSV-TK-expressing and ihSPIO-labeled mOct4− BM-MAPCs to distribute within and around the glioblastoma. We have engrafted 5 × 105 mOct4− BM-MAPCs into the mouse brain, of which only a fraction (1 or 10 %) of the injected cells was labeled with ihSPIO particles, as 3 × 105 cells already generated extensive hypointense contrast (Fig. 3). Evaluation of the grafted cells by MRI showed that when 10 % (Fig. 3b), but not 1 % (Fig. 3a) of the stem cells were labeled with ihSPIO particles it was possible to follow them by MRI as indicated by the hypointense signal. One representative animal is shown in Fig. 3c.Fig. 3

Bottom Line: Subsequently, ganciclovir (GCV) treatment was commenced and the fate of both the MAPCs and the tumor were followed by multimodal imaging (MRI and bioluminescence imaging).Noteworthy, in some phosphate-buffered saline-treated animals (33 %), a significant decrease in tumor size was seen compared to sham-operated animals, which could potentially also be caused by a synergistic effect of the immune-modulatory stem cells.This treatment could be followed and guided noninvasively in vivo by MRI and bioluminescence imaging.

View Article: PubMed Central - PubMed

Affiliation: Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000, Leuven, Belgium. cindy.leten@gmail.com.

ABSTRACT

Introduction: In this study, we planned to assess if adult stem cell-based suicide gene therapy can efficiently eliminate glioblastoma cells in vivo. We investigated the therapeutic potential of mouse Oct4(-) bone marrow multipotent adult progenitor cells (mOct4(-) BM-MAPCs) in a mouse glioblastoma model, guided by multimodal in vivo imaging methods to identify therapeutic windows.

Methods: Magnetic resonance imaging (MRI) of animals, wherein 5 × 10(5) syngeneic enhanced green fluorescent protein-firefly luciferase-herpes simplex virus thymidine kinase (eGFP-fLuc-HSV-TK) expressing and superparamagnetic iron oxide nanoparticle labeled (1 % or 10 %) mOct4(-) BM-MAPCs were grafted in glioblastoma (GL261)-bearing animals, showed that labeled mOct4(-) BM-MAPCs were located in and in close proximity to the tumor. Subsequently, ganciclovir (GCV) treatment was commenced and the fate of both the MAPCs and the tumor were followed by multimodal imaging (MRI and bioluminescence imaging).

Results: In the majority of GCV-treated, but not phosphate-buffered saline-treated animals, a significant difference was found in mOct4(-) BM-MAPC viability and tumor size at the end of treatment. Noteworthy, in some phosphate-buffered saline-treated animals (33 %), a significant decrease in tumor size was seen compared to sham-operated animals, which could potentially also be caused by a synergistic effect of the immune-modulatory stem cells.

Conclusions: Suicide gene therapy using mOct4(-) BM-MAPCs as cellular carriers was effective in reducing the tumor size in the majority of the GCV-treated animals leading to a longer progression-free survival compared to sham-operated animals. This treatment could be followed and guided noninvasively in vivo by MRI and bioluminescence imaging. Noninvasive imaging is of particular interest for a rapid and efficient validation of stem cell-based therapeutic approaches for glioblastoma and hereby contributes to a better understanding and optimization of a promising therapeutic approach for glioblastoma patients.

No MeSH data available.


Related in: MedlinePlus