AML is a cancer of the blood and bone marrow characterized by the presence of
highly proliferative and abnormally differentiated myeloblasts. Previous work from the
Bhatia lab utilized the orthotopic xenograft model in order to isolate a population of
leukemic regenerating cells (LRC) that exists prior to relapse. Affymatrix analysis of LRCs
revealed up-regulation of 248 genes that can act as unique targets to prevent relapse. In
order to screen compounds against all 248 targets, it is important to develop an in vitro
model that is able to appropriately recapture the functional and molecular markers of
LRCs. Primary AML samples were treated with 5-doses of 0.15 μM, 1 μM AraC, or DMSO
control and several outcomes were measured. In vitro AraC treatment was not able to
recapitulate the progenitor frequency curve and CD34 expression curve observed in vivo.
Additionally, we were not able to see a consistent increase in select LRC targets DRD2,
GLUT2, FUT3, and FASL via flow cytometry. Despite an increase in the mRNA levels of
LRC genes 24h after treatment with 0.15 μM AraC, long term analysis could not be
completed due to poor RNA quality and low expression of LRC-targets. Primary AML cells
were co-culture with mouse MS-5 stromal cell line order to study the effects of
mesenchymal stromal cells on AML response to AraC. Co-culture with MS-5 cells had
different effects on select primary AML cells. AML 14939 showed an increase in CD34
and LRC targets DRD2 and FUT3 following AraC treatment when co-cultured with MS-5
cells; while A374 showed no differences between DMSO and AraC treated groups.
Overall, these findings suggest the LRC signature is not induced by treatment with AraC
alone. Complex interactions between AML cells and their bone marrow niche during AraC
treatment plays an important role in the development of LRCs prior to AML relapse. / Thesis / Master of Science (MSc) / AML is a cancer of blood cells characterized by the presence of rapidly dividing
cancer cells termed myeloblasts. AML has a high rate of disease relapse. The Bhatia lab
modelled AML relapse in a mouse and discovered an unique population of cells that exist
prior to relapse termed LRCs. LRCs express distinctive genes that can act as targets for
the development of new therapies to prevent relapse. In order to screen potential relapse preventing compounds, we set out to recapture AML relapse using cells in a dish. AML
cells from patients were treated with chemotherapy reagent AraC and the number of
cancer progenitors and the expression of specific LRC proteins were measured. AraC did
not increase the level of 3 out of 4 LRC proteins studied. We determined the LRCs were
not caused by AraC treatment, and the physiology of the bone marrow environment plays
an important role in inducing relapse.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22422 |
| Date | 16 November 2017 |
| Creators | Ye, Wenqing |
| Contributors | Bhatia, Mick, Biochemistry and Biomedical Sciences |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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