—Danio rerio— : Extracellular matrix and cancer cell growth in the zebrafish xenograft model
Ylinen, Nina (2023)
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20231105143235
https://urn.fi/URN:NBN:fi-fe20231105143235
Tiivistelmä
Cancer is an exponentially growing health concern worldwide. Besides genetic mutations and altered proliferation patterns, the microenvironment, and the cancer cell niche function as an essential regulator of the tumors’ ability to proliferate and metastasize. While in vitro culturing including spheroid and organotypic models have provided valuable insight into cancer biology, their ability to recapitulate and accurately predict in vivo outcomes is limited. The inconsistency between results obtained in in vitro studies versus in vivo studies has led to a vast majority of promising treatments failing when expanded to animal trials and clinical testing. In contrast to the murine xenograft model, the zebrafish offers many benefits regarding space requirements, cost-effectiveness, and ethical considerations. Therefore, zebrafish avatars hold promise for drug screenings on patient-derived xenografts and expansion potential in the field of personalized medicine.
This project aimed to investigate alternative methods for MDA-MB-231 mCherry tumor cell detection beyond fluorescent microscopy, as well as to explore how extracellular matrixes (ECMs), namely Grow-Dex®, Matrigel®, PureCol® (collagen), Fibronectin, and Gelatin, could be utilized to affect the survival, growth, and migration of cancer cell xenografts in zebrafish embryos. Using human mitochondrial DNA as the target sequence for qPCR demonstrated adequate sensitivity for detecting MDA-MB-231 mCherry tumor cells from single embryo samples. Compared to the established protocols done by fluorescent microscopy, the method as such was not deemed adequate but would need further standardization and validation to be considered applicable. The experiments combining MDA-MB-231 mCherry tumor cells with ECMs followed up with fluorescent imaging indicate that Matrigel®, PureCol®, and Gelatin positively affect the size of the primary tumor transplant. The ECMs did not, however, affect the number of cells dissociating from the xenograft injection site, nor the rate at which the tumor grew over the incubation period. In conclusion, while no additional benefit from ECMs on fold-change or changes in migrating cells could be observed, the increased success rate and decrease in variability of the xenografts could advocate for the usage of ECMs in conjunction with the zebrafish cancer xenograft model.
This project aimed to investigate alternative methods for MDA-MB-231 mCherry tumor cell detection beyond fluorescent microscopy, as well as to explore how extracellular matrixes (ECMs), namely Grow-Dex®, Matrigel®, PureCol® (collagen), Fibronectin, and Gelatin, could be utilized to affect the survival, growth, and migration of cancer cell xenografts in zebrafish embryos. Using human mitochondrial DNA as the target sequence for qPCR demonstrated adequate sensitivity for detecting MDA-MB-231 mCherry tumor cells from single embryo samples. Compared to the established protocols done by fluorescent microscopy, the method as such was not deemed adequate but would need further standardization and validation to be considered applicable. The experiments combining MDA-MB-231 mCherry tumor cells with ECMs followed up with fluorescent imaging indicate that Matrigel®, PureCol®, and Gelatin positively affect the size of the primary tumor transplant. The ECMs did not, however, affect the number of cells dissociating from the xenograft injection site, nor the rate at which the tumor grew over the incubation period. In conclusion, while no additional benefit from ECMs on fold-change or changes in migrating cells could be observed, the increased success rate and decrease in variability of the xenografts could advocate for the usage of ECMs in conjunction with the zebrafish cancer xenograft model.