Establishing patient derived xenograft (PDX) models for targeted treatment of metastatic endometrial cancer
Endometrial cancer is amongst the most common cancer types in women in western countries, and incidence is expected to rise due to higher life expectancy and increased overweight in the population. Women with metastatic endometrial cancer usually have poor prognosis, as traditional cytostatic drugs have moderate response rates and limited survival benefits. Individually tailored treatment of metastatic endometrial cancer based on molecular characterization of tumors is expected to increase survival rates and improve quality of life for these patients.
Tumor models based on implantation of patient biopsies in mice (PDX models) are considered to be highly relevant for preclinical therapeutic studies, particularly when tumor is implanted in the organ of origin (orthotopic). We therefore aim to 1) establish clinically representative orthotopic PDX models of metastatic endometrial cancer, and 2) use these models to assess the systemic effect of novel targeted therapies, using a maximum of 120 female NSG mice.
We hypothesize that tumor growth and metastatic dissemination in PDX mouse models will be similar to that of human endometrial cancer patients. We also anticipate that treating PDX tumors with drugs selected based on tumor biomarker expression will improve outcome in mouse models of metastatic endometrial cancer. Treatment response in PDX models is expected to be representative of the response in corrresponding human patients, and findings from preclinical treatment studies may therefore provide clinical hypotheses for treatment response in endometrial tumors with similar molecular features. Non-invasive imaging of PDX models will be used as a supplement to clincial examination for improved assessment of disease stage and therapeutic response.
Based on previous experience with orthotopic endometrial carcinoma PDX models, metastatic lesions are mostly localized to abdominal lymph nodes and parametric structures with limited burden to the animals. However, in severe cases mice may experience metastases to lungs, liver and kidneys, which can cause symptoms such as shortness of breath, jaundice and renal failure. Mice will be euthanized immediately if such conditions are suspected, thus reducing the time of distress to as short as possible. In vitro cultivation of patient cells will be tested prior to xenografting in order to eliminate non-viable samples. This will thus reduce the number of animals needed for establishment of each model (reduction). The anti-tumor effect of potential drugs will also be tested in vitro before being included in in vivo experiment, further reducing the number of animals. To limit suffering, mice will be monitored by imaging and abdominal palpation for detection of metastatic disease at an early stage. This will improve the assessment of animal welfare and identification humane endpoints (refinement).
Tumor models based on implantation of patient biopsies in mice (PDX models) are considered to be highly relevant for preclinical therapeutic studies, particularly when tumor is implanted in the organ of origin (orthotopic). We therefore aim to 1) establish clinically representative orthotopic PDX models of metastatic endometrial cancer, and 2) use these models to assess the systemic effect of novel targeted therapies, using a maximum of 120 female NSG mice.
We hypothesize that tumor growth and metastatic dissemination in PDX mouse models will be similar to that of human endometrial cancer patients. We also anticipate that treating PDX tumors with drugs selected based on tumor biomarker expression will improve outcome in mouse models of metastatic endometrial cancer. Treatment response in PDX models is expected to be representative of the response in corrresponding human patients, and findings from preclinical treatment studies may therefore provide clinical hypotheses for treatment response in endometrial tumors with similar molecular features. Non-invasive imaging of PDX models will be used as a supplement to clincial examination for improved assessment of disease stage and therapeutic response.
Based on previous experience with orthotopic endometrial carcinoma PDX models, metastatic lesions are mostly localized to abdominal lymph nodes and parametric structures with limited burden to the animals. However, in severe cases mice may experience metastases to lungs, liver and kidneys, which can cause symptoms such as shortness of breath, jaundice and renal failure. Mice will be euthanized immediately if such conditions are suspected, thus reducing the time of distress to as short as possible. In vitro cultivation of patient cells will be tested prior to xenografting in order to eliminate non-viable samples. This will thus reduce the number of animals needed for establishment of each model (reduction). The anti-tumor effect of potential drugs will also be tested in vitro before being included in in vivo experiment, further reducing the number of animals. To limit suffering, mice will be monitored by imaging and abdominal palpation for detection of metastatic disease at an early stage. This will improve the assessment of animal welfare and identification humane endpoints (refinement).
Etterevaluering
Vi klassifiserer forsøket som betydelig belastende, jf. forsøksdyrforskriften vedlegg B.
Bakgrunnen for denne vurderingen er at musene vil gjennomgå ulike prosedyrer som samlet vil kunne gi betydelig belastning. Mattilsynet er forpliktet etter regelverket til å etterevaluere alle forsøk som er betydelig belastende for forsøksdyrene.
Bakgrunnen for denne vurderingen er at musene vil gjennomgå ulike prosedyrer som samlet vil kunne gi betydelig belastning. Mattilsynet er forpliktet etter regelverket til å etterevaluere alle forsøk som er betydelig belastende for forsøksdyrene.
Begrunnelse for etterevalueringen
The main aim of the study has been to establish metastatic orthotopic PDX models clinically relevant for endometrial cancer, and to use the models to evaluate the effect of new, targeted treatments.
This aim was achieved by successfully establishing eight PDX models derived from eight different patients, including five metastatic models.
Histology, protein marker expression and genetic profile were highly concordant between PDXs and corresponding patient tumors. Also, response to chemotherapy in vivo was similar to response observed in the corresponding organoid models in vitro.
Both orthotopic and subcutaneous models were treated with standard chemotherapy to validate the models and to evaluate the utility and feasability of non-invasive imaging for monitoring tumor development and treatment response.
This is the first study that demonstrates that MRI and PET/CT are highly feasible for monitoring tumor progression and treatment response in organoid based PDX models of endometrial cancer.
The researchers have also developed radiomic models (based on MRI) that were able to predict treatment response at an early timepoint.
The second aim of evaluating systemic effect of targeted treatment was not achieved.
The researchers have screened their organoid models for a panel of targeted drugs but did not reach the stage of validating treatment effect in vivo within the timeframe of this project.
45 of 120 mice were used. 13 mice were reported with mild severity, 29 mice with moderate severity and 3 with high severity.
The responsible researcher informs that the researchers have generated both orthotopic and subcutaneous models in this study.
Their assessment is that the mice experienced less stress when cells were implanted orthotopically. The research group will continue with orthotopic models, non-invasive imaging (MRI and/or PET/CT) and image-guided endpoints.
In parallel with this study, the research group has established a collection of patient-derived organoids models that genetically are highly representative of the patient donor.
Evaluating novel targeted therapies in the future, organoids will be tested for panels of drugs to select the models that are candidates for in vivo validation.
Organoids may therefore replace most animal models in the future.
The responsible researcher informs that they have failed to detect statistical significance in experiments with five mice in each group and may therefore consider increasing the number of mice to eight in each group for later experiments.
They have been able to re-use data from several animal experiments (for example by using new analyses methods) leading to a total reduction of animals needed in the project.
The endpoints in the study were based on imaging markers. By MRI the researchers have been able to non-invasively monitor the tumor growth and end the experiments humanely when statistically significant results were reached.
Establishment of this preclinical platform is highly important for future preclinical studies, particularly studies aiming at understanding metastatic dissemination and evaluating treatment strategies for metastatic endometrial cancers.
This aim was achieved by successfully establishing eight PDX models derived from eight different patients, including five metastatic models.
Histology, protein marker expression and genetic profile were highly concordant between PDXs and corresponding patient tumors. Also, response to chemotherapy in vivo was similar to response observed in the corresponding organoid models in vitro.
Both orthotopic and subcutaneous models were treated with standard chemotherapy to validate the models and to evaluate the utility and feasability of non-invasive imaging for monitoring tumor development and treatment response.
This is the first study that demonstrates that MRI and PET/CT are highly feasible for monitoring tumor progression and treatment response in organoid based PDX models of endometrial cancer.
The researchers have also developed radiomic models (based on MRI) that were able to predict treatment response at an early timepoint.
The second aim of evaluating systemic effect of targeted treatment was not achieved.
The researchers have screened their organoid models for a panel of targeted drugs but did not reach the stage of validating treatment effect in vivo within the timeframe of this project.
45 of 120 mice were used. 13 mice were reported with mild severity, 29 mice with moderate severity and 3 with high severity.
The responsible researcher informs that the researchers have generated both orthotopic and subcutaneous models in this study.
Their assessment is that the mice experienced less stress when cells were implanted orthotopically. The research group will continue with orthotopic models, non-invasive imaging (MRI and/or PET/CT) and image-guided endpoints.
In parallel with this study, the research group has established a collection of patient-derived organoids models that genetically are highly representative of the patient donor.
Evaluating novel targeted therapies in the future, organoids will be tested for panels of drugs to select the models that are candidates for in vivo validation.
Organoids may therefore replace most animal models in the future.
The responsible researcher informs that they have failed to detect statistical significance in experiments with five mice in each group and may therefore consider increasing the number of mice to eight in each group for later experiments.
They have been able to re-use data from several animal experiments (for example by using new analyses methods) leading to a total reduction of animals needed in the project.
The endpoints in the study were based on imaging markers. By MRI the researchers have been able to non-invasively monitor the tumor growth and end the experiments humanely when statistically significant results were reached.
Establishment of this preclinical platform is highly important for future preclinical studies, particularly studies aiming at understanding metastatic dissemination and evaluating treatment strategies for metastatic endometrial cancers.