Functional analyses of leukemia associated genes
(2014) MOBN01 20141Degree Projects in Molecular Biology
- Abstract
- Infant (<1 year of age) acute lymphoblastic leukemia (ALL) is a malignancy characterized by rearrangements of the lysin-specific methyltransferase 2A (KMT2A/MLL) gene at 11q23 in 80% of cases and with a very poor outcome. Recently, we identified recurrent mutations in FLT3 (FLT3N676K) and PIK3R1 (PIK3R1Y580fs, PIK3R1Y580*) through whole genome sequencing of infant ALL. To gain a better understanding of this subtype, we wanted to investigate if these mutations collaborate with the primary MLL-rearrangements (MLL-R). Using an in vivo retroviral overexpression model system, we therefore chose to investigate MLL-AF9, a well-known leukemia associated gene, co-expressed with FLT3N676K. A murine bone marrow transplantation assay was carried out... (More)
- Infant (<1 year of age) acute lymphoblastic leukemia (ALL) is a malignancy characterized by rearrangements of the lysin-specific methyltransferase 2A (KMT2A/MLL) gene at 11q23 in 80% of cases and with a very poor outcome. Recently, we identified recurrent mutations in FLT3 (FLT3N676K) and PIK3R1 (PIK3R1Y580fs, PIK3R1Y580*) through whole genome sequencing of infant ALL. To gain a better understanding of this subtype, we wanted to investigate if these mutations collaborate with the primary MLL-rearrangements (MLL-R). Using an in vivo retroviral overexpression model system, we therefore chose to investigate MLL-AF9, a well-known leukemia associated gene, co-expressed with FLT3N676K. A murine bone marrow transplantation assay was carried out where mice receiving MLL-AF9 together with the FLT3N676K rapidly succumb to a myeloid disease at a median latency of 28 days while mice receiving MLL-AF9 alone had a median latency of 47.5 days. An in vitro colony forming unit assay using transduced bone marrow cells with PIK3R1Y580fs, PIK3R1Y580* or FLT3N676K was performed showing a self-renewal capacity at a late onset of FLT3N676K while PIK3R1Y580fs and PIK3R1Y580* are not able to cause self-renewal. Our findings about FLT3N676K are a step in the right direction of establishing its potential role in leukemogenesis. (Less)
- Popular Abstract
- Cancer is a vast group of diseases with one thing in common: cells are exposed to uncontrolled growth and are not able to mature into different cell types (differentiate). This makes the cell unable to commit self-programmed suicide (apoptosis), but instead continue to divide and pass on the defects. All types of cancers are a result from alterations in the genetic material (DNA) of the diseased cells. Normally, all cells have the same portion of DNA but in cancer, genetic material have been lost, gained, relocated and/or altered through mutations, leading to new properties of the genes, resulting in abnormal cell function. The most common type of cancer in children is acute leukemia, which is a cancer in the blood affecting the cells of... (More)
- Cancer is a vast group of diseases with one thing in common: cells are exposed to uncontrolled growth and are not able to mature into different cell types (differentiate). This makes the cell unable to commit self-programmed suicide (apoptosis), but instead continue to divide and pass on the defects. All types of cancers are a result from alterations in the genetic material (DNA) of the diseased cells. Normally, all cells have the same portion of DNA but in cancer, genetic material have been lost, gained, relocated and/or altered through mutations, leading to new properties of the genes, resulting in abnormal cell function. The most common type of cancer in children is acute leukemia, which is a cancer in the blood affecting the cells of the immune system having an acute onset.
Acute leukemia results in an accumulation of immature blood cells in the bone marrow, and sometimes in the blood. The infiltration of these cells results in a suppression of the healthy cells. Symptoms include increased risk for infections, weakness and paleness. Depending on the genetic alterations and in what kind of cell the leukemia occurs, the disease can be further classified into acute lymphoblastic leukemia (ALL) that affects T-cells and B-cells, and acute myeloid leukemia (AML) that affects immune cells of the myeloid lineage; such as granulocytes. These diseases can be further classified into different subtypes depending on their genetic alterations. The most common genetic change seen in acute leukemia is so-called translocations that result in the fusion of two genes from unrelated chromosomes. Today, these genetic alterations are used to diagnose and to classify patients into different risk groups receiving different therapies.
Infant leukemia occurs in children of one year of age or younger and are characterized by rearrangements of a gene known as MLL and have a very poor prognosis. We have previously found novel mutations in two genes (FLT3 and PIK3R1) in infant ALL cases. To gain a better understanding of how these mutations contribute to disease, we used a murine transplantation assay where we injected bone marrow cells, in which we had introduced a mutated FLT3 gene, together with a MLL-AF9 fusion gene, a primary genetic alteration that is commonly seen in infant ALL. Mice that received cells with both a FLT3 mutation and the MLL-AF9 fusion gene succumbed to disease more rapidly than mice that received the MLL-AF9 fusion gene alone. These results indicate that the FLT3 mutation contribute to leukemia development and accelerates disease onset. Also, a cell culture experiment gave similar results confirming our findings that cells with these mutations are not able to commit suicide, but instead continue dividing.
In the future these findings could be of importance in proving that the mutations are contributing to acute leukemia. It is a step in the right direction of establishing the mutations potential role in leukemia and can, in the future, be of value when developing novel therapies.
Supervisor: Anna Andersson, PhD
Master´s Degree Project 45 credits in Molecular Biology 2014
Department of Biology, Lund University
Medical Faculty, Department of Clinical Genetics, Lund University (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/4698296
- author
- Yao Mattisson, Ingrid
- supervisor
- organization
- course
- MOBN01 20141
- year
- 2014
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 4698296
- date added to LUP
- 2014-10-16 15:09:27
- date last changed
- 2014-10-16 15:09:27
@misc{4698296,
abstract = {{Infant (<1 year of age) acute lymphoblastic leukemia (ALL) is a malignancy characterized by rearrangements of the lysin-specific methyltransferase 2A (KMT2A/MLL) gene at 11q23 in 80% of cases and with a very poor outcome. Recently, we identified recurrent mutations in FLT3 (FLT3N676K) and PIK3R1 (PIK3R1Y580fs, PIK3R1Y580*) through whole genome sequencing of infant ALL. To gain a better understanding of this subtype, we wanted to investigate if these mutations collaborate with the primary MLL-rearrangements (MLL-R). Using an in vivo retroviral overexpression model system, we therefore chose to investigate MLL-AF9, a well-known leukemia associated gene, co-expressed with FLT3N676K. A murine bone marrow transplantation assay was carried out where mice receiving MLL-AF9 together with the FLT3N676K rapidly succumb to a myeloid disease at a median latency of 28 days while mice receiving MLL-AF9 alone had a median latency of 47.5 days. An in vitro colony forming unit assay using transduced bone marrow cells with PIK3R1Y580fs, PIK3R1Y580* or FLT3N676K was performed showing a self-renewal capacity at a late onset of FLT3N676K while PIK3R1Y580fs and PIK3R1Y580* are not able to cause self-renewal. Our findings about FLT3N676K are a step in the right direction of establishing its potential role in leukemogenesis.}},
author = {{Yao Mattisson, Ingrid}},
language = {{eng}},
note = {{Student Paper}},
title = {{Functional analyses of leukemia associated genes}},
year = {{2014}},
}