3BP2 was originally identified through its interaction with the ABL kinase. Fusion of ABL with the BCR gene forms the BCR-ABL onco-protein, which is causative in Chronic Myeloid Leukemia (CML) and acute lymphoid leukemia (ALL). Due to the ability of 3BP2 to regulate ABL activity in osteoblasts, we hypothesize that 3BP2 modulates BCR-ABL signalling. Overexpression of 3BP2 in the CML-T1 cell line produced a marked decrease in global tyrosine phosphorylation. 3BP2 overexpression also resulted in a significant increase in CML-T1 cell growth, accompanied by altered ERK1/2, AKT, SYK, LYN, HCK, and CBL phosphorylation and expression. A phospho-SRC family protein and a 116 kDa phospho-protein were identified as 3BP2 interaction partners in response to BCR-ABL activation. BCR-ABL bone marrow transplantation (BMT) models in 3bp2-/- mice exhibit accelerated disease compared to wild-type mice, with altered leukemic phenotype. In conclusion, 3BP2 is able to modulate signalling through BCR-ABL and affect BCR-ABL-induced disease outcome.

Both tissue microenvironment and genetic changes are involved in development of cancer. We employed the Friend murine leukemia virus (F-MuLV)- induced erythroleukemia model to study the role of these parameters in induction of malignancy. The tissue microenvironment is composed of non-cellular and cellular components. In regards to the non-cellular part, we previously reported that vascular endothelial growth factor (VEGF), in combination with macrophage chemoattractant protein-5, contributes to leukemia progression in F-MuLV- infected mice. To study the influence of constitutively elevated VEGF levels on the progression of erythroleukemia, we inoculated VEGF hi/+ mice, which are heterozygous for a VEGF “hypermorphic” allele, with F-MuLV. Unexpectedly, a significant delay in erythroleukemia was observed in these mice when compared with wild-type controls. The VEGF hi/+ mice exhibited a higher natural killer (NK) cell activity, elevated B cells, and a decrease in T-cell number. Furthermore, higher erythroid progenitors (i.e. CD34+, CD36+, and TER119+ cells) were evident in the bone marrow, spleen, and peripheral blood of these mice. Also, the CFU-E levels were significantly elevated in VEGF hi/+ bone marrow cultures. We propose that a compensatory erythropoietic response combined with increased NK cell activity account for the extended survival of erythroleukemic, VEGF hi/+mice. In regards to the cellular component of tissue microenvironment we studied the role of B cells in response to F-MuLV. To test the hypothesis that virus- neutralizing antibodies are involved in providing sterilizing immunity to F-MuLV we inoculated adult female mice with F-MuLV so that their newborns are provided with anti-viral antibodies. F-MuLV challenge of these newborns did not lead to induction of erythroleukemia. Conversely, mice from a control group (newborns whose mother had not received viral inoculation) contracted erythroleukemia upon F-MuLV challenge, as shown by hepatosplenomegaly, anemia, and emergence of leukemic cells in the spleen. These results indicated the importance of anti-viral antibodies in immunity to F-MuLV and suggested that anti-F-MuLV antibodies were generated in mothers, transferred to their offspring and protected them from viral challenge. The key genetic event upon F-MuLV infection is viral integration at the Fli-1 locus. We set to identify F-MuLV integration sites in SCID mice following two observations that these mice show a delay in induction of leukemia and also they do not exhibit viral integration at the Fli-1 locus. We hypothesized that development of leukemia in these mice is due to F-MuLV integration at a region other than the Fli-1 locus. Using a GenomeWalking approach we identified a total of 15 viral integration sites in F-MuLV-infected SCID mice, with eight of them interrupting the following genes: Mex3d, Fam125b, Prdm16, Rhoq, Ahdc1, Zc3h4, Msh3, and Hcls1. Using PCR to amplify the virus- host DNA junction fragment we found that one of the viral insertion sites (chromosome 10; position 20,942,825) occurs with a frequency of 35 % and therefore is considered as a common integration site.

Feline leukemia viruses (FeLVs) are pathogenic retroviruses of the domestic cat. FeLV transmission and emergence of pathogenic variants show striking similarity to HIV pathogenesis. The emergence of pathogenic subgroup-C FeLV from the transmitted subgroup-A FeLV coincides with a switch in host receptor used for infection as a result of mutations in the viral envelope protein (Env). I have characterized a novel FeLV Env that may represent an evolutionary intermediate between FeLV-A and FeLV-C. I have also reported evidence suggesting that FeLVs may use co-factors/co-receptors for infection. I have found that FeLVs inefficiently infect murine NIH3T3 cells overexpressing FeLV receptors (NIH3T3/Receptor). I have provided evidence that the low infection is caused by a block at a post-binding but pre-entry stage of FeLV infection. Furthermore, fusion of NIH3T3/Receptor cells with highly susceptible cells rescues inhibition to infection suggesting that FeLVs, like HIV, may also use co-receptors for infection.

Both tissue microenvironment and genetic changes are involved in development of cancer. We employed the Friend murine leukemia virus (F-MuLV)- induced erythroleukemia model to study the role of these parameters in induction of malignancy. The tissue microenvironment is composed of non-cellular and cellular components. In regards to the non-cellular part, we previously reported that vascular endothelial growth factor (VEGF), in combination with macrophage chemoattractant protein-5, contributes to leukemia progression in F-MuLV- infected mice. To study the influence of constitutively elevated VEGF levels on the progression of erythroleukemia, we inoculated VEGF hi/+ mice, which are heterozygous for a VEGF “hypermorphic” allele, with F-MuLV. Unexpectedly, a significant delay in erythroleukemia was observed in these mice when compared with wild-type controls. The VEGF hi/+ mice exhibited a higher natural killer (NK) cell activity, elevated B cells, and a decrease in T-cell number. Furthermore, higher erythroid progenitors (i.e. CD34+, CD36+, and TER119+ cells) were evident in the bone marrow, spleen, and peripheral blood of these mice. Also, the CFU-E levels were significantly elevated in VEGF hi/+ bone marrow cultures. We propose that a compensatory erythropoietic response combined with increased NK cell activity account for the extended survival of erythroleukemic, VEGF hi/+mice. In regards to the cellular component of tissue microenvironment we studied the role of B cells in response to F-MuLV. To test the hypothesis that virus- neutralizing antibodies are involved in providing sterilizing immunity to F-MuLV we inoculated adult female mice with F-MuLV so that their newborns are provided with anti-viral antibodies. F-MuLV challenge of these newborns did not lead to induction of erythroleukemia. Conversely, mice from a control group (newborns whose mother had not received viral inoculation) contracted erythroleukemia upon F-MuLV challenge, as shown by hepatosplenomegaly, anemia, and emergence of leukemic cells in the spleen. These results indicated the importance of anti-viral antibodies in immunity to F-MuLV and suggested that anti-F-MuLV antibodies were generated in mothers, transferred to their offspring and protected them from viral challenge. The key genetic event upon F-MuLV infection is viral integration at the Fli-1 locus. We set to identify F-MuLV integration sites in SCID mice following two observations that these mice show a delay in induction of leukemia and also they do not exhibit viral integration at the Fli-1 locus. We hypothesized that development of leukemia in these mice is due to F-MuLV integration at a region other than the Fli-1 locus. Using a GenomeWalking approach we identified a total of 15 viral integration sites in F-MuLV-infected SCID mice, with eight of them interrupting the following genes: Mex3d, Fam125b, Prdm16, Rhoq, Ahdc1, Zc3h4, Msh3, and Hcls1. Using PCR to amplify the virus- host DNA junction fragment we found that one of the viral insertion sites (chromosome 10; position 20,942,825) occurs with a frequency of 35 % and therefore is considered as a common integration site.

Cancer remains one of the most common causes for death in the world today. Researchers are continuously trying to improve old, and develop new, methods in order to strife this global problem. Much research is being made trying to find new specific biomarkers that can be used to detect and diagnose cancer in an early stage. One candidate protein for possible future use as a biomarker is tripeptidyl-peptidase II (TPPII) which has previously been shown to be up-regulated in Burkitt´s lymphoma. This paper focuses on the expression of TPPII on an mRNA-level to see if there is any difference between expression in human leucocytes from patients with a leukemia diagnosis and a healthy volunteer, in order to evaluate if the expression of TPPII have any future use as a biomarker. Patient samples were analyzed using real time qPCR, to study the expression of mRNA, and Western blot, in order to correlate the mRNA findings with protein expression. Three different cell lines with different characteristics regarding expression and function of TPPII were also used to validate the methods used and for comparison with the patient samples analyzed. A difference in expression of mRNA were seen between the different patient samples, both individually and between larger groups of samples with the same diagnosis, indicating a large individual variation, thus making future use in a clinical setting difficult. However, seeing as only a few samples were analyzed in this study, more research must be done in order to draw any final conclusions.

B-cell chronic lymphocytic leukemia is the most common leukemia in the adult population of Western developed countries. In 2005, an estimated 9,730 adults in the United States will be diagnosed with B-CLL and an estimated 4,600 deaths will occur. B-CLL is a common heterogeneous malignant disease with variable outcome. B-CLL is divided into two groups based on whether somatic hypermutation is observed in the variable region of the immunoglobulin heavy-chain locus (IgVH). The two distinct groups are named mutated and unmutated. The B-CLL mutated group has a more favorable prognosis than the unmutated group. Gene expression profiling has been used successfully to decipher the biological and clinical diversity of many leukemias and lymphomas. Recently, other small RNAs (microRNAs) have been shown to be important in hematopoiesis. MicroRNAs are small 20-28 nucleotide RNAs that are believed to control many important cellular and developmental processes by posttranscriptional gene silencing, translational repression, and modulating epigenetic events. We are interested in whether microRNA expression correlates with the mutational status of IgVH. This study is significant in the following ways: (1) microRNAs may become surrogate markers for the mutational status of IgVH of B-CLL, which implies a more rapid diagnostic means as compared to the current practice, and (2) microRNAs, in the particular context of B-CLL, may play some significant roles in a gene regulatory network that is further responsible for chromosomal abnormalities found in B-CLL. This thesis presents a study comparing microRNA expression in mutated and unmutated B-CLL groups. Instead of using a genome-wide expression profiling strategy, we selected a specific set of microRNAs based on their chromosome locations and mRNA targets. Specifically, we chose the following eight microRNAs (with their chromosomal abnormalities): mir16-1 (deletion 13), let-7i (trisomy 12), mir196-2 (trisomy 12), mir26a-2 (trisomy 12), mir-34b (deletion 11), mir-125b (deletion 11), mir-181C (trisomy 19), mir-125a (trisomy 19). We used solution hybridization assays to monitor the expression of microRNAs. We successfully characterized the microRNA expression in twelve B-CLL patient samples (eight mutated and four unmutated). Among the eight microRNAs examined, three (mir196-2, mir-125a, mir-125b) are not expressed in the two B-CLL groups, four (mir16-1, mir26a-2, let-7i, mir-34b) have significant differences in expressions over the two groups, and one (mir-181c) has no significant difference in expressions over the two groups.

Acute megakaryoblastic leukemia (AMKL) was first described by Von Boros and Karangi in 1931, was a result of developments in ultrastructural cytochemistry and immunologic phenotyping acute myeloid leukemia (AML) of megakaryocytic lineage have been diagnosed increasingly. The French-American-British (FAB) Co-operative Group established the criteria for the diagnosis and added this category as a distinct subtype of AML (M7) in 1985. The main subtypes of AML in the infants are M4, M5, and M7. One 25-day-old infant was referred to the hospital for further examination of white blood cell. Hepatosplenomegaly and anemia were physically examined, and he was diagnosed to be an AMKL case. Abnormal karyotype 46,XY,t(1;1)(p13;p36) was observed in this patient. This study aims to identify the AMKL potentially related genes on the breakpoints of Homo sapiens autosomal (HSA) 1p13 and 1p36 in this case by candidate gene approaches. Data-mining of the AMKL potentially related genes on breakpoints of HSA1p13 and 1p36 through NCBI Map Viewer Database, OMIM Morbid Map, and OMIM Gene Map were performed. We identified three candidate genes on HSA1p13 and 15 candidate genes on HSA 1p36. RBM15-MKL1 fusion on t(1;22)(p13;q13) was reported to be AMKL genes by Ma et al., Mercher et al., and the Mitelman Database of Chromosome Aberrations in Cancer. We anticipated RBM15 is also a related gene on HSA1p13 in this AMKL case, and compared the Gene Ontology terms between MKL1 and these 15 candidate genes on HSA1p36. SKI becomes our first candidate gene on 1p36 in this case. To identify candidate genes locating at HSA1p13 and 1p36, including RBM15 and SKI were screened at both cDNA and genomic DNA levels. According to these results, RBM15 and SKI are more likely to be candidate genes. Thus RBM15 and SKI may be the novel AMKL genes in t(1;1)(p13;p36) AMKL patients.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes bibliographical references and vita.

Thesis (Ph. D.)--University of Chicago, Dept. of Pathaology, 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Virginia, 2001. / Includes bibliographical references (leaves 182-215). Also available online through Digital Dissertations.