Anissa M Jabbour

Monash University (Australia) · Department of Clinical Haematology and the Australian Centre for Blood Diseases

Desmoplastic small round cell tumor (DSRCT) is characterized by the presence of a fusion protein EWS/WT1, arising from the t (11;22) (p13;q12) translocation. Here we examine the oncogenic properties of two splice variants of EWS/WT1, EWS/WT1-KTS and EWS/WT1 + KTS. We over-expressed both EWS/WT1 variants in murine embryonic fibroblasts (MEFs) of wil...

The activation of the Akt signalling in response to cytokine receptor signalling promotes protein synthesis, cellular growth and proliferation. To determine the role of Akt in interleukin-3 (IL-3) signalling, we generated IL-3-dependent myeloid cell lines from mice lacking Akt1, Akt2 or Akt3. Akt1 deletion resulted in accelerated apoptosis at low c...

p53 is critical in the normal response to a variety of cellular stresses including DNA damage and loss of p53 function is a common feature of many cancers. In hematological malignancies, p53 deletion is less common than in solid malignancies but is associated with poor prognosis and resistance to chemotherapy. Compared to their wild-type (WT) count...

Loss of p53-dependent apoptosis contributes to the development of hematologic malignancies and failure to respond to treatment. Proapoptotic Bcl-2 family member Puma is essential for apoptosis in HoxB8-immortalized interleukin-3 (IL-3)-dependent myeloid cell lines (FDM cells) provoked by IL-3 deprivation. p53 and FoxO3a can transcriptionally regula...

Bcl-2 family members regulate apoptosis in response to cytokine withdrawal and a broad range of cytotoxic stimuli. Pro-apoptotic Bcl-2 family members Bax and Bak are essential for apoptosis triggered by interleukin-3 (IL-3) withdrawal in myeloid cells. The BH3-only protein Puma is critical for initiation of IL-3 withdrawal-induced apoptosis, becaus...

Recurrent oncogenic fusion genes play a critical role in the development of various cancers and diseases and provide, in some cases, excellent therapeutic targets. To date, analysis tools that can identify and compare recurrent fusion genes across multiple samples have not been available to researchers. To address this deficiency, we developed Co-o...

Targeted therapies are frequently combined with standard cytotoxic drugs to enhance clinical response. Targeting the BCL-2 family of proteins is an attractive option to combat chemoresistance in leukemia. Pre-clinical and clinical studies indicate modest single-agent activity with selective BCL-2 inhibitors (e.g. venetoclax). We show that venetocla...

This chapter describes techniques for characterizing metazoan apoptotic pathways using Saccharomyces cerevisiae. Active forms of the major apoptotic effectors—caspases, Bax and Bak—are all lethal to yeast. Using this lethality as a readout of caspase/Bax/Bak activity, proteins and small molecules that directly or indirectly regulate the activity of...

Deregulated expression of Hox genes such as HoxA9 is associated with development of myeloproliferative disorders and leukemia and indicates a poor prognosis. To investigate the molecular mechanisms by which HoxA9 promotes immortalization of hematopoietic cells, we generated growth factor dependent myeloid cells in which HoxA9 expression is regulate...

Hoxb8 overexpression immortalises haematopoietic progenitor cells in a growth-factor-dependant manner and co-operates with interleukin-3 (IL-3) to cause acute myeloid leukaemia. To further understand how Hoxb8 contributes to myeloid cell immortalisation, we generated IL-3-dependant myeloid cells expressing Hoxb8 under the control of an inducible pr...

Resistance to cell death is a hallmark of cancer and renders transformed cells resistant to multiple apoptotic triggers. The Bcl-2 family member, Mcl-1, is a key driver of cell survival in diverse cancers, including acute myeloid leukemia (AML). A screen for compounds that downregulate Mcl-1 identified the kinase inhibitor, PIK-75, which demonstrat...

Differential pathway expression in p53−/− samples after IL-3 loss. p53−/− FDM cell clones were withdrawn of IL-3 for 6 or 18 h were analyzed by SPIA. Significant pathways are shown (FDR<0.1). (TIF)

ERK activation after IL-3 stimulation of WT and p53−/− FDM cells. Lysates were extracted from WT pr p53−/− FDM cells cultured in the absence of IL-3 for 16 h followed by a 15 minute IL-3 re-addition at various concentrations (as indicated). Lysates were resolved by SDS-PAGE and immunoblotted with antibodies specific to phospho-ERK, total ERK and ßa...

AKT inhibition does not alter ERK1/2 phosphorylation and MEK inhibition does not affect AKT phosphorylation. Lysates were extracted from cells treated with either AKTi or MEKi and resolved on SDS-PAGE and immunoblotted with the indicated antibodies. The predominant isoform of Bim is BimL. An asterisk indicates the correct Puma band. ßactin is shown...

Protein expression of SOCS1, SOCS3, RIPK3, ß common chain, IL-3 α chain and Bcl11a in WT and p53−/− FDM cells. (A and B) Lysates were extracted from multiple clones of WT or p53−/− FDM cells cultured in IL-3. Lysates were resolved by SDS-PAGE and immunoblotted with antibodies specific the indicated proteins. ßactin is shown as a loading control. (A...

P53-upregulated modifier of apoptosis (PUMA), a pro-apoptotic member of the Bcl-2 family, is transcriptionally activated by p53 and is a key effector of p53-dependent apoptosis. We show that PUMA protein is subject to rapid post-translational regulation by phosphorylation at a conserved residue, serine 10, following serum or interleukin-3 (IL-3) st...

It has long been known that many cell types are dependent on specific cytokines that signal proliferation, regulate differentiation and suppress apoptosis. A detailed picture of the structure of several cytokine receptors has added to our understanding of the molecular mechanism of receptor activation. An explosion of knowledge of apoptosis pathway...

Puma (p53 upregulated modulator of apoptosis) belongs to the BH3 (Bcl-2 homology 3)-only protein family of apoptotic regulators. Its expression is induced by various apoptotic stimuli, including irradiation and cytokine withdrawal. Using an inducible system to express Puma, we investigated the nature of Puma-induced apoptosis. In BaF3 cells, expres...

The Hox family of homeodomain transcription factors are essential for the regulation of hematopoiesis and deregulated expression of some Hox gene is associated with the development of myeloproliferative disorders and leukaemia. In mammals, 39 Hox genes are organized into four clusters (A, B, C or D). The expression of these genes is tightly regulat...

Cell death and differentiation is a monthly research journal focused on the exciting field of programmed cell death and apoptosis. It provides a single accessible source of information for both scientists and clinicians, keeping them up-to-date with advances in the field. It encompasses programmed cell death, cell death induced by toxic agents, dif...

Bad, Bim, and PI3 kinase, but depends in part on Puma Cell death provoked by loss of interleukin-3 signaling is independent of Growth and survival of hematopoietic cells is regulated by growth factors and cyto-kines, such as interleukin 3 (IL-3). When cytokine is removed, cells dependent on IL-3 kill themselves by a mechanism that is inhibited by o...

Although the anti-apoptotic activity of Bcl-2 has been extensively studied, its mode of action is still incompletely understood. In the nematode Caenorhabditis elegans, 131 of 1090 somatic cells undergo programmed cell death during development. Transgenic expression of human Bcl-2 reduced cell death during nematode development, and partially comple...

Caspases are a family of cysteine proteases with roles in cytokine maturation or apoptosis. Caspase-2 was the first pro-apoptotic caspase identified, but its functions in apoptotic signal transduction are still being elucidated. This study examined the regulation of the activity of caspase-2 using recombinant proteins and a yeast-based system. Our...

A genetically defined pathway orchestrates the removal of 131 of the 1090 somatic cells generated during the development of the hermaphrodite nematode Caenorhabditis elegans. Regulation of apoptosis is highly evolutionarily conserved and the nematode cell death pathway is a valuable model for studying mammalian apoptotic pathways, the dysregulation...

Cells often respond to viral infection by activating a cellular suicide process, limiting viral replicative potential and hence minimising the spread of the infection. This cellular self-destruction, termed apoptosis, occurs in a tightly regulated, morphologically and biochemically defined manner. To counter this host response to infection, some vi...

This study characterized the ability of a new member of the p35 family, p49, to inhibit a number of mammalian and insect caspases. p49 blocked apoptosis triggered by treatment with Fas ligand (FasL), Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or ultraviolet (UV) radiation but provided negligible protection against apoptosis ind...