Breeding of the transgenic C57Bl6 Wnt-1 mice with the transgenic mouse strain B6.129P2-Axltm1Dgen/J in order to study the role of Axl in mammary tumor development
1. Study purpose
AXL is a tyrosine kinase transmembrane receptor belonging to the TAM family, which regulates a whole range of cellular responses. In adult tissues, AXL expression is restricted to smooth muscles cells, but elevated levels are found in various disease states such as cancer. In cancer patients, AXl expression is associated with widespread metastasis and poor overall survival. We have previously bred B6.129P2-Axltm1Dgen/J strain to elucidate the role AXL in absence of expression (FOTS 11928). In this project, we want to crossbreed the B6.129P2-Axltm1Dgen/J mouse strain with C57Bl6 Wnt-1 strain where the latter strain develop mammary tumours. Crossing these strains will allow us to assess the tumour incidence and relapse in the absence or presence of AXL expression. Preliminary data suggests to corroborate our hypothesis (FOTS 11927, FOTS 6638).
2. Expected harm to animals
Animals with malignant phenotypes are expected to suffer moderate distress and/or pain. However, measures are taken as to lessen this burden as mush as possible. The animals will be monitored daily for signs of pain and/or distress. They will be sacrificed before they reach human endpoint specified in the score sheet.
3. Expected benefits to scientific community and society
We hypothesize that AXL expression in cancer is associated with metastasis and overall poor prognosis. This project will provide insights into tumour signaling in the presence or absence of AXL expression. These insights can contribute to a larger understanding of cancer malignancies and potentially targets for therapy in the future.
4. Amount of animals and species/strain
We plan to use 500 of each of the B6.129P2-Axltm1Dgen/J and C57Bl6 Wnt-1 strains.
5. Complying with replacement, reduction, and refinement
The purpose of these studies are to understand the role AXL has in cancer malignancies, and to unveil the AXL signaling in the microenvironment. In vitro experiments are done to reduce the number of animals, but to mimic the whole body complexity it is necessary to perform in vivo studies. Furthermore, animals will be used both for in vivo and ex vivo studies, and the breeding will be planned according to the experiments needed in order to reduce amount of animals. As this projects build on previous projects (FOTS 6638, and FOTS 11927), we take advantage of already having established a functional breeding strategy. Homozygous wild type animals are excluded from the colony in order to exclude unwanted phenotype and to decrease the number of not-targeted alleles amongst newborn pups. In order to select animals with targeted genotypes, small biopsies are taken from the ear. This approach allow reduction of animals used in experiments. As the colony is established, backcrossing will be performed using C57bl6/J from The Jackson Laboratory with particular focus on limiting inbred mice in order to maintain healthy animals in the colony. The normal state in these animals does not cause pain and no painful procedures will be performed during breeding. We do however expect some of the wnt-1 positive animals to develop tumours from the age of 10 weeks.
AXL is a tyrosine kinase transmembrane receptor belonging to the TAM family, which regulates a whole range of cellular responses. In adult tissues, AXL expression is restricted to smooth muscles cells, but elevated levels are found in various disease states such as cancer. In cancer patients, AXl expression is associated with widespread metastasis and poor overall survival. We have previously bred B6.129P2-Axltm1Dgen/J strain to elucidate the role AXL in absence of expression (FOTS 11928). In this project, we want to crossbreed the B6.129P2-Axltm1Dgen/J mouse strain with C57Bl6 Wnt-1 strain where the latter strain develop mammary tumours. Crossing these strains will allow us to assess the tumour incidence and relapse in the absence or presence of AXL expression. Preliminary data suggests to corroborate our hypothesis (FOTS 11927, FOTS 6638).
2. Expected harm to animals
Animals with malignant phenotypes are expected to suffer moderate distress and/or pain. However, measures are taken as to lessen this burden as mush as possible. The animals will be monitored daily for signs of pain and/or distress. They will be sacrificed before they reach human endpoint specified in the score sheet.
3. Expected benefits to scientific community and society
We hypothesize that AXL expression in cancer is associated with metastasis and overall poor prognosis. This project will provide insights into tumour signaling in the presence or absence of AXL expression. These insights can contribute to a larger understanding of cancer malignancies and potentially targets for therapy in the future.
4. Amount of animals and species/strain
We plan to use 500 of each of the B6.129P2-Axltm1Dgen/J and C57Bl6 Wnt-1 strains.
5. Complying with replacement, reduction, and refinement
The purpose of these studies are to understand the role AXL has in cancer malignancies, and to unveil the AXL signaling in the microenvironment. In vitro experiments are done to reduce the number of animals, but to mimic the whole body complexity it is necessary to perform in vivo studies. Furthermore, animals will be used both for in vivo and ex vivo studies, and the breeding will be planned according to the experiments needed in order to reduce amount of animals. As this projects build on previous projects (FOTS 6638, and FOTS 11927), we take advantage of already having established a functional breeding strategy. Homozygous wild type animals are excluded from the colony in order to exclude unwanted phenotype and to decrease the number of not-targeted alleles amongst newborn pups. In order to select animals with targeted genotypes, small biopsies are taken from the ear. This approach allow reduction of animals used in experiments. As the colony is established, backcrossing will be performed using C57bl6/J from The Jackson Laboratory with particular focus on limiting inbred mice in order to maintain healthy animals in the colony. The normal state in these animals does not cause pain and no painful procedures will be performed during breeding. We do however expect some of the wnt-1 positive animals to develop tumours from the age of 10 weeks.