Dedifferentiated liposarcoma with leukocytosis. A case report of G-CSF-producing soft-tissue tumors, possible association with undifferentiated liposarcoma lineage

<p>Abstract</p> <p>Background</p> <p>Granulocyte-colony-stimulating factor (G-CSF) functions as a hematopoietic growth factor and it is responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies.</p> <p>Case presentation</p> <p>We report the case of a 72-year-old man with dedifferentiated liposarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma (MFH)-like features in addition to well-differentiated lipoma-like liposarcoma, arising from his upper arm. Preoperative laboratory data showed leukocytosis (103,700/μl). The serum level of G-CSF was also elevated (620 pg/ml [normal, <8 pg/ml]). Nine days after the surgery, the leukocytosis was relieved (WBC; 6,920/μl) and the elevated serum G-CSF level was significantly decreased (G-CSF; 12 pg/ml). One month after the surgery, leukocytosis gradually began to appear again. Three months after the surgery metastatic lung lesions were confirmed, and the patient subsequently died of respiratory problems. In the English literature regarding soft-tissue tumors with leukocytosis, including the current case, we could review a total of 6 cases of liposarcoma with leukocytosis. The subtype of these 6 liposarcoma cases was undifferentiated liposarcoma, comprising dedifferentiated liposarcoma in 4 cases and pleomorphic liposarcoma in 2 cases.</p> <p>Conclusion</p> <p>Since the only other soft-tissue tumor that was associated with leukocytosis was MFH, and since MFH is characterized by the absence of any specific differentiation, we would like to propose a possible association between G-CSF-producing soft-tissue tumors and an undifferentiated liposarcoma lineage, such as dedifferentiated liposarcoma or pleomorphic liposarcoma.</p

Analysis of Aurora kinase A expression in CD34+ blast cells isolated from patients with myelodysplastic syndromes and acute myeloid leukemia

Aurora kinase A, also known as aurora A, is a serine/threonine kinase that plays critical roles in mitosis entry, chromosome alignment, segregation, and cytokinesis. Overexpression of aurora A has been observed in many solid tumors and some hematopoietic neoplasms, but little is known about its expression in myeloid diseases. Because cytogenetic abnormalities play an essential role in the pathogenesis of myeloid malignancies, we hypothesized that aurora A deregulation may be involved in myelodysplastic syndromes and acute myeloid leukemia and contribute to the chromosomal instability observed in these diseases. We assessed aurora A mRNA levels in CD34+ bone marrow blasts from nine patients with acute myeloid leukemia, 20 patients with myelodysplastic syndromes, and five normal patients serving as controls. CD34+ blasts were isolated from bone marrow aspirate specimens using magnetic activated cell separation technology. RNA was extracted from purified CD34+ cells, and quantitative real-time reverse transcriptase polymerase chain reaction for aurora A was performed. Immunocytochemical analyses for total aurora A, phosphorylated aurora A, Ki-67, and activated caspase 3 were performed on cytospin slides made from purified CD34+ cells in myelodysplastic syndrome patients using standard methods. Aurora A mRNA and protein levels were correlated, as was aurora A mRNA level, with blast counts, cytogenetic abnormalities, and International Prognostic Scoring System score. We found that CD34+ cells in myelodysplastic syndromes and acute myeloid leukemia expressed aurora A at significantly higher levels (P = 0.01 and P = 0.01, respectively) than normal CD34+ cells. Aurora A mRNA levels correlated with total and phosphorylated protein levels (P = 0.0002 and P = 0.02, respectively). No significant correlation was found between aurora A mRNA level and blast count, blast viability, cytogenetic abnormalities, or the International Prognostic Scoring System score in patients with myelodysplastic syndromes. We conclude that aurora A is up-regulated in CD34+ blasts from myeloid neoplasms

Constitutive Phosphorylation of Aurora-A on Ser51 Induces Its Stabilization and Consequent Overexpression in Cancer

The serine/threonine kinase Aurora-A (Aur-A) is a proto-oncoprotein overexpressed in a wide range of human cancers. Overexpression of Aur-A is thought to be caused by gene amplification or mRNA overexpression. However, recent evidence revealed that the discrepancies between amplification of Aur-A and overexpression rates of Aur-A mRNA were observed in breast cancer, gastric cancer, hepatocellular carcinoma, and ovarian cancer. We found that aggressive head and neck cancers exhibited overexpression and stabilization of Aur-A protein without gene amplification or mRNA overexpression. Here we tested the hypothesis that aberration of the protein destruction system induces accumulation and consequently overexpression of Aur-A in cancer.Aur-A protein was ubiquitinylated by APC(Cdh1) and consequently degraded when cells exited mitosis, and phosphorylation of Aur-A on Ser51 was observed during mitosis. Phosphorylation of Aur-A on Ser51 inhibited its APC(Cdh1)-mediated ubiquitylation and consequent degradation. Interestingly, constitutive phosphorylation on Ser51 was observed in head and neck cancer cells with protein overexpression and stabilization. Indeed, phosphorylation on Ser51 was observed in head and neck cancer tissues with Aur-A protein overexpression. Moreover, an Aur-A Ser51 phospho-mimetic mutant displayed stabilization of protein during cell cycle progression and enhanced ability to cell transformation.Broadly, this study identifies a new mode of Aur-A overexpression in cancer through phosphorylation-dependent inhibition of its proteolysis in addition to gene amplification and mRNA overexpression. We suggest that the inhibition of Aur-A phosphorylation can represent a novel way to decrease Aur-A levels in cancer therapy

Therapeutic effects of STAT3 decoy oligodeoxynucleotide on human lung cancer in xenograft mice

<p>Abstract</p> <p>Background</p> <p>Signal transducer and activator of transcription 3 (STAT3) is usually constitutively activated in a variety of malignancies. Therefore, STAT3 may be a promising target for treatment of tumor cells. To explore the possibility of a double-stranded decoy oligodeoxynucleotide (ODN) targeted blocking STAT3 over-activated tumor cells, we, here, evaluate the efficacy of STAT3 decoy ODN on human lung cancer cells <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>A STAT3 decoy ODN was transfected into A549 lung cancer cell line <it>in vitro </it>by using lipofectamine. The flow cytometry and fluorescent microscopy were used to detect the transfection efficiency and the sub-cellular localization of STAT3 decoy ODN in A549 cells. Cell proliferation was determined by counting cell numbers and [³H]-thymidine uptake. Cell apoptosis was examined with Annexin V and propidum iodide by flow cytometry. The expression levels of STAT3 target genes were identified by RT-PCR and immunoblot. For <it>in vivo </it>experiment, A549 lung carcinoma-nude mice xenograft was used as a model to examine the effect of the STAT3 decoy by intratumoral injection. At the end of treatment, TUNEL and immunohistochemistry were used to examine the apoptosis and the expression levels of bcl-xl and cyclin D1 in tumor tissues.</p> <p>Results</p> <p>STAT3 decoy ODN was effectively transfected into A549 lung cancer cells and mainly located in nucleus. STAT3-decoy ODN significantly induced apoptosis and reduced [³H]-thymidine incorporation of A549 cells as well as down-regulated STAT3-target genes <it>in vitro</it>. STAT3 decoy ODN also dramatically inhibited the lung tumor growth in xenografted nude mice and decreased gene expression of bcl-xl and cyclin D1.</p> <p>Conclusion</p> <p>STAT3 decoy ODN significantly suppressed lung cancer cells <it>in vitro </it>and <it>in vivo</it>, indicating that STAT3 decoy ODN may be a potential therapeutic approach for treatment of lung cancer.</p

Evolution of Resistance to Aurora Kinase B Inhibitors in Leukaemia Cells

Aurora kinase inhibitors are new mitosis-targeting drugs currently in clinical trials for the treatment of haematological and solid malignancies. However, knowledge of the molecular factors that influence sensitivity and resistance remains limited. Herein, we developed and characterised an in vitro leukaemia model of resistance to the Aurora B inhibitor ZM447439. Human T-cell acute lymphoblastic leukaemia cells, CCRF-CEM, were selected for resistance in 4 µM ZM447439. CEM/AKB4 cells showed no cross-resistance to tubulin-targeted and DNA-damaging agents, but were hypersensitive to an Aurora kinase A inhibitor. Sequencing revealed a mutation in the Aurora B kinase domain corresponding to a G160E amino acid substitution. Molecular modelling of drug binding in Aurora B containing this mutation suggested that resistance is mediated by the glutamate substitution preventing formation of an active drug-binding motif. Progression of resistance in the more highly selected CEM/AKB8 and CEM/AKB16 cells, derived sequentially from CEM/AKB4 in 8 and 16 µM ZM447439 respectively, was mediated by additional defects. These defects were independent of Aurora B and multi-drug resistance pathways and are associated with reduced apoptosis mostly likely due to reduced inhibition of the catalytic activity of aurora kinase B in the presence of drug. Our findings are important in the context of the use of these new targeted agents in treatment regimes against leukaemia and suggest resistance to therapy may arise through multiple independent mechanisms

Necdin, a Negative Growth Regulator, Is a Novel STAT3 Target Gene Down-Regulated in Human Cancer

Cytokine and growth factor signaling pathways involving STAT3 are frequently constitutively activated in many human primary tumors, and are known for the transcriptional role they play in controlling cell growth and cell cycle progression. However, the extent of STAT3's reach on transcriptional control of the genome as a whole remains an important question. We predicted that this persistent STAT3 signaling affects a wide variety of cellular functions, many of which still remain to be characterized. We took a broad approach to identify novel STAT3 regulated genes by examining changes in the genome-wide gene expression profile by microarray, using cells expressing constitutively-activated STAT3. Using computational analysis, we were able to define the gene expression profiles of cells containing activated STAT3 and identify candidate target genes with a wide range of biological functions. Among these genes we identified Necdin, a negative growth regulator, as a novel STAT3 target gene, whose expression is down-regulated at the mRNA and protein levels when STAT3 is constitutively active. This repression is STAT3 dependent, since inhibition of STAT3 using siRNA restores Necdin expression. A STAT3 DNA-binding site was identified in the Necdin promoter and both EMSA and chromatin immunoprecipitation confirm binding of STAT3 to this region. Necdin expression has previously been shown to be down-regulated in a melanoma and a drug-resistant ovarian cancer cell line. Further analysis of Necdin expression demonstrated repression in a STAT3-dependent manner in human melanoma, prostate and breast cancer cell lines. These results suggest that STAT3 coordinates expression of genes involved in multiple metabolic and biosynthetic pathways, integrating signals that lead to global transcriptional changes and oncogenesis. STAT3 may exert its oncogenic effect by up-regulating transcription of genes involved in promoting growth and proliferation, but also by down-regulating expression of negative regulators of the same cellular processes, such as Necdin

Ashwagandha Derived Withanone Targets TPX2-Aurora A Complex: Computational and Experimental Evidence to its Anticancer Activity

Cancer is largely marked by genetic instability. Specific inhibition of individual proteins or signalling pathways that regulate genetic stability during cell division thus hold a great potential for cancer therapy. The Aurora A kinase is a Ser/Thr kinase that plays a critical role during mitosis and cytokinesis and is found upregulated in several cancer types. It is functionally regulated by its interactions with TPX2, a candidate oncogene. Aurora A inhibitors have been proposed as anticancer drugs that work by blocking its ATP binding site. This site is common to other kinases and hence these inhibitors lack specificity for Aurora A inhibition in particular, thus advocating the need of some alternative inhibition route. Previously, we identified TPX2 as a cellular target for withanone that selectively kill cancer cells. By computational approach, we found here that withanone binds to TPX2-Aurora A complex. In experiment, withanone treatment to cancer cells indeed resulted in dissociation of TPX2-Aurora A complex and disruption of mitotic spindle apparatus proposing this as a mechanism of the anticancer activity of withanone. From docking analysis, non-formation/disruption of the active TPX2-Aurora A association complex could be discerned. Our MD simulation results suggesting the thermodynamic and structural stability of TPX2-Aurora A in complex with withanone further substantiates the binding. We report a computational rationale of the ability of naturally occurring withanone to alter the kinase signalling pathway in an ATP-independent manner and experimental evidence in which withanone cause inactivation of the TPX2-Aurora A complex. The study demonstrated that TPX2-Aurora A complex is a target of withanone, a potential natural anticancer drug

Negative regulation of signal transducer and activator of transcription-3 signalling cascade by lupeol inhibits growth and induces apoptosis in hepatocellular carcinoma cells

Background: Constitutive activation of signal transducer and activator of transcription signalling 3 (STAT3) has been linked with survival, proliferation and angiogenesis in a wide variety of malignancies including hepatocellular carcinoma (HCC). Methods: We evaluated the effect of lupeol on STAT3 signalling cascade and its regulated functional responses in HCC cells. Results: Lupeol suppressed constitutive activation of STAT3 phosphorylation at tyrosine 705 residue effectively in a dose- and time-dependent manner. The phosphorylation of Janus-activated kinases (JAKs) 1 and 2 and Src was also suppressed by lupeol. Pervanadate treatment reversed the downregulation of phospho-STAT3 induced by lupeol, thereby indicating the involvement of a phosphatase. Indeed, we observed that treatment with lupeol increased the protein and mRNA levels of SHP-2, and silencing of SHP-2 abolished the inhibitory effects of lupeol on STAT3 activation. Treatment with lupeol also downregulated the expression of diverse STAT3-regulated genes and decreased the binding of STAT3 to VEGF promoter. Moreover, the proliferation of various HCC cells was significantly suppressed by lupeol, being associated with substantial induction of apoptosis. Depletion of SHP-2 reversed the observed antiproliferative and pro-apoptotic effects of lupeol. Conclusions: Lupeol exhibited its potential anticancer effects in HCC through the downregulation of STAT3-induced pro-survival signalling cascade