Treatment of malignant brain tumors using EA01 and EA02
1 Purpose
Malignant brain tumors are associated with extremely poor patient prognosis due to the inefficiency of current therapeutic strategies. Our group has recently shown that Thioridazine, a phenothiazine extensively used for the treatment of schizophrenia, represents a chemosensitizing agent for the treatment of glioblastoma (GBM) (Johannessen et al., 2018). As Thioridazine was withdrawn from the market in 2005 due to adverse effects, we synthesized two novel analogues based on the molecular structure of Thioridazine. Our in-vitro studies revealed a direct cytotoxic effect on both GBM and melanoma brain metastases (MBM) cells. Interestingly, cytotoxicity was not observed in both normal astrocytes and brain organoids, -indicating that these two novel compounds have a significant therapeutic window. Therefore, the current study aims to analyze the effect of these novel drugs, EA01 and EA02, in-vivo using our patient-derived GBM and MBM xenograft models.
2 Distress
From our prior experience, the implantation of primary brain tumor cells into the brains of nude mice are well tolerated by the animals and a pilot toxicity study in mice demonstrated a good safety profile of both drugs. However, the growth of the tumors will cause moderate distress to the animals. The animals will be closely monitored and euthanized if the attached objective endpoint criteria are met.
3 Expected benefit
If successful, we hope to implement a novel and better treatment for patients suffering from malignant brain tumors.
4 Number of animals, and what kind
130 nod/scid mice.
5 How to adhere to 3R
Replacement
Tumor cell invasion is highly dependent on the tumor microenvironment, which is very complex and cannot be fully mimicked in vitro. In order to evaluate a therapeutic potential and to possibly bring novel treatments into the clinic, we depend on further analysis in our well-established patient-derived xenograft models.
Refinement
The method of stereotactic orthotopic intracranial implantation is a well-established and refined technique in our group. Two trained people will be used, one to inject the tumor cells, and the other responsible for animal care. While the anesthetized animals will be heated, the cells will be injected stereotactically with mild harm to the animal. During imaging, two trained persons will be present, one to prepare and monitor the animals, and the other to operate the imaging instrumentation. The animals will be heated during imaging. The imaging procedures do not cause any harm to the animals.
Animals will be monitored daily by trained people and weighed twice/week. As imaging will be performed regularly, we will be able to detect the tumor burden prior to any symptoms in animal behavior. Based on the specific criteria mentioned in the score-sheet, analgesia will be administered as early as necessary and animals will be sacrificed if the objective endpoints are met, prior to developing severe harm.
Reduction
The high success rate of tumor development after implantation in our group gives us the possibility to cut down the number of animals in each experimental group.
Malignant brain tumors are associated with extremely poor patient prognosis due to the inefficiency of current therapeutic strategies. Our group has recently shown that Thioridazine, a phenothiazine extensively used for the treatment of schizophrenia, represents a chemosensitizing agent for the treatment of glioblastoma (GBM) (Johannessen et al., 2018). As Thioridazine was withdrawn from the market in 2005 due to adverse effects, we synthesized two novel analogues based on the molecular structure of Thioridazine. Our in-vitro studies revealed a direct cytotoxic effect on both GBM and melanoma brain metastases (MBM) cells. Interestingly, cytotoxicity was not observed in both normal astrocytes and brain organoids, -indicating that these two novel compounds have a significant therapeutic window. Therefore, the current study aims to analyze the effect of these novel drugs, EA01 and EA02, in-vivo using our patient-derived GBM and MBM xenograft models.
2 Distress
From our prior experience, the implantation of primary brain tumor cells into the brains of nude mice are well tolerated by the animals and a pilot toxicity study in mice demonstrated a good safety profile of both drugs. However, the growth of the tumors will cause moderate distress to the animals. The animals will be closely monitored and euthanized if the attached objective endpoint criteria are met.
3 Expected benefit
If successful, we hope to implement a novel and better treatment for patients suffering from malignant brain tumors.
4 Number of animals, and what kind
130 nod/scid mice.
5 How to adhere to 3R
Replacement
Tumor cell invasion is highly dependent on the tumor microenvironment, which is very complex and cannot be fully mimicked in vitro. In order to evaluate a therapeutic potential and to possibly bring novel treatments into the clinic, we depend on further analysis in our well-established patient-derived xenograft models.
Refinement
The method of stereotactic orthotopic intracranial implantation is a well-established and refined technique in our group. Two trained people will be used, one to inject the tumor cells, and the other responsible for animal care. While the anesthetized animals will be heated, the cells will be injected stereotactically with mild harm to the animal. During imaging, two trained persons will be present, one to prepare and monitor the animals, and the other to operate the imaging instrumentation. The animals will be heated during imaging. The imaging procedures do not cause any harm to the animals.
Animals will be monitored daily by trained people and weighed twice/week. As imaging will be performed regularly, we will be able to detect the tumor burden prior to any symptoms in animal behavior. Based on the specific criteria mentioned in the score-sheet, analgesia will be administered as early as necessary and animals will be sacrificed if the objective endpoints are met, prior to developing severe harm.
Reduction
The high success rate of tumor development after implantation in our group gives us the possibility to cut down the number of animals in each experimental group.