Progression Of Malignant Disease Research Articles

ETS1 Mediates MEK1/2-Dependent Overexpression of Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) in Human Cancer Cells

EGFR-MEK-ERK signaling pathway has an established role in promoting malignant growth and disease progression in human cancers. Therefore identification of transcriptional targets mediating the oncogenic effects of the EGFR-MEK-ERK pathway would be highly relevant. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently characterized human oncoprotein. CIP2A promotes malignant cell growth and is over expressed at high frequency (40–80%) in most of the human cancer types. However, the mechanisms inducing its expression in cancer still remain largely unexplored. Here we present systematic analysis of contribution of potential gene regulatory mechanisms for high CIP2A expression in cancer. Our data shows that evolutionary conserved CpG islands at the proximal CIP2A promoter are not methylated both in normal and cancer cells. Furthermore, sequencing of the active CIP2A promoter region from altogether seven normal and malignant cell types did not reveal any sequence alterations that would increase CIP2A expression specifically in cancer cells. However, treatment of cancer cells with various signaling pathway inhibitors revealed that CIP2A mRNA expression was sensitive to inhibition of EGFR activity as well as inhibition or activation of MEK-ERK pathway. Moreover, MEK1/2-specific siRNAs decreased CIP2A protein expression. Series of CIP2A promoter-luciferase constructs were created to identify proximal −27 to −107 promoter region responsible for MEK-dependent stimulation of CIP2A expression. Additional mutagenesis and chromatin immunoprecipitation experiments revealed ETS1 as the transcription factor mediating stimulation of CIP2A expression through EGFR-MEK pathway. Thus, ETS1 is probably mediating high CIP2A expression in human cancers with increased EGFR-MEK1/2-ERK pathway activity. These results also suggest that in addition to its established role in invasion and angiogenesis, ETS1 may support malignant cellular growth via regulation of CIP2A expression and protein phosphatase 2A inhibition.

Prognostic significance of angiogenesis and angiogenic growth factors in nonsmall cell lung cancer.

Currently, nonsmall-cell lung cancer (NSCLC) is the leading cause of cancer-related death in the United States. Angiogenesis, the formation of new vasculature, is a complex and tightly regulated process that promotes metastasis and disease progression in lung cancer and other malignancies. Developmental antiangiogenic agents have shown activity in NSCLC, and bevacizumab, an antiangiogenic monoclonal antibody, is approved for the treatment of patients with advanced disease. However, predictive biomarkers are needed to guide the administration of antiangiogenic agents. It is possible that angiogenic molecules could accurately predict patient response to targeted antiangiogenic therapies, which would allow individualized and perhaps more effective treatment. Angiogenic signaling molecules may also have value as prognostic indicators, which may be useful for the management of NSCLC. Here the author provides an overview of angiogenic molecules currently being investigated as prognostic biomarkers in NSCLC and discusses their potential to guide treatment choices.

Prostate tumor cells with cancer progenitor properties have high telomerase activity and are rapidly killed by telomerase interference

Cancer progenitor cells (CPCs) have been postulated to promote treatment resistance and disease progression in prostate and other malignancies. We investigated whether the enzyme telomerase, which is active in cancer cells and in normal stem cells, plays an important role in CPC which can be exploited to neutralize these cells. We used flow cytometry and assays of gene expression, clonogenicity, and invasiveness to isolate and characterize a putative CPC subpopulation from freshly resected human prostatectomy specimens. Telomerase activity was measured by qPCR-based Telomeric Repeat Amplification Protocol (TRAP). Telomerase interference was achieved by ectopic expression of a mutated telomerase RNA construct which reprograms telomerase to generate "toxic" uncapped telomeres. Treated cells were assayed for apoptosis, proliferation in culture, and xenograft tumor formation. CPC in prostate tumors expressed elevated levels of genes associated with a progenitor phenotype and were highly clonogenic and invasive. Significantly, CPC telomerase activity was 20- to 200-fold higher than in non-CPC from the same tumors, and CPC were exquisitely sensitive to telomerase interference which induced rapid apoptosis and growth inhibition. Similarly, induction of telomerase interference in highly tumorigenic CPC isolated from a prostate cancer cell line abrogated their ability to form tumor xenografts. Human prostate tumors contain a CPC subpopulation with markedly elevated telomerase activity which renders them acutely susceptible to telomerase interference. These findings offer the first tumor-derived and in vivo evidence that telomerase may constitute a CPC "Achilles heel" which may ultimately form the basis for more effective new CPC-targeting therapies.

CCL3 (MIP-1α) plasma levels and the risk for disease progression in chronic lymphocytic leukemia

AbstractB-cell receptor (BCR) signaling has been inferred as an important mechanism for disease progression in chronic lymphocytic leukemia (CLL) and other B-cell malignancies. In response to BCR activation, CLL cells secrete the chemokine CCL3, which fosters interactions between CLL cells and the leukemia microenvironment. CCL3 secretion correlates with expression of the 70-kDa ζ-associated protein (ZAP-70) and responsiveness of the CLL clone to BCR stimulation. Here, we measured CCL3 plasma levels by enzyme-linked immunosorbent assay (ELISA) in 351 CLL patients and examined CCL3 levels for associations with established prognostic markers and time from diagnosis to initial therapy. We found that CCL3 plasma concentrations were strongly associated with established prognostic markers. In a Cox proportional hazards regression model, CCL3 as well as established prognostic markers (immunoglobulin heavy chain variable-region mutation status, CD38 or ZAP-70 cytogenetics, clinical stage) were significantly associated with time to treatment. Multivariable analysis revealed that CCL3 (hazard ratio [HR] = 2.33, P < .0001), advanced clinical stage (HR = 2.75, P = .0025), poor risk cytogenetics (del 17p, HR = 2.38; del11q, HR = 2.36, P = .001), and CD38 expression (HR = 1.43, P = .023) were independent prognostic markers. Collectively, CCL3 is a novel, robust, and independent prognostic marker in CLL that can easily and reliably be measured by ELISA. CCL3 therefore should become useful for risk assessment in patients with CLL.

Abstract A21: Global DNA methylation analysis of bronchial epithelia of former smokers with COPD, with and without lung cancer

Abstract Introduction: Emerging evidence suggests that aberrant epigenetic regulation is involved in the development and progression of malignant and nonmalignant respiratory diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. Moreover, patients with COPD have an increased risk of developing lung cancer. Besides similar risk factors such as tobacco smoke exposure, little is known about the shared biology between COPD and lung cancer. Smoking causes aberrations in airway and lung parenchyma at both the genomic and epigenomic levels, resulting in global changes to gene expression. In this study, we hypothesize that alterations at the level of DNA methylation in airway epithelia of former smokers (FS) with COPD with and without non-small cell lung cancer (NSCLC) may be used to identify genes involved in the pathogenesis of these respiratory diseases, independent of the effects of active smoking. Methods: Bronchial epithelial cells were obtained from brushings of small airways (&amp;lt; 2 mm diameter) during bronchoscopy from FS with COPD (n=22), without COPD (n=22) and patients with COPD as well as previous surgical resection of Stage I NSCLC (n=6). Illumina's Infinium Methylation (HM27) assay was used to assess DNA methylation status of 27,578 CpG sites associated with 14,475 genes. Results: COPD patients are distinguished from non-COPD patients based on airway methylation profiles. Genes differentially methylated in airways between COPD and non-COPD patients include several modulators of aryl hydrocarbon receptor and IL6 signaling, as well as genes previously implicated in COPD, including immune chemotaxis regulators (CXCL11, CCR8) and GABA receptor signaling (GABRA5). Airway epithelial DNA from COPD patients with NSCLC compared to those without NSCLC was differentially methylated at sites encoding multiple key regulators of xenobiotic metabolism, regulators of free radical savaging/detoxification and retinol metabolic pathway components including several alcohol dehydrogenase, glutathione S transferase, and UDP glucoronosyltransferase genes. Conclusion: Our preliminary results suggest a role for DNA methylation in the deregulation of previously identified COPD-related genes, and specifically highlight differences in airways of COPD patients with/without NSCLC corresponding to well-known smoking-related metabolomic processes. Knowledge of DNA methylation disruption will further our understanding of the etiological role of COPD in the development of lung cancer, and contribute to the development of chemo-prevention strategies targeting the biology of both COPD and NSCLC. Supported by CIHR. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A21.

Expression and Clinical Significance of FAK and Src Proteins in Human Endometrial Adenocarcinoma

Focal Adhesion Kinase (FAK) is a protein tyrosine kinase, localised in the focal adhesions, which, upon activation interacts with Src, another tyrosine kinase, regulating several cellular signalling pathways. Both enzymes have been implicated in malignant transformation and disease progression. The aim of the present study was to evaluate the clinical significance of FAK and Src expression in cases of endometrial adenocarcinoma. The total (t) and the activated, phosphorylated (p) forms of FAK and Src proteins were assessed immunohistochemically in tumour specimens obtained from 43 endometrial adenocarcinoma patients and were statistically analyzed in relation to various clinicopathological parameters and tumour proliferative capacity, reflected by Ki-67 labelling index. t-FAK positivity was significantly correlated with FIGO disease stage (p = 0.031), and t-FAK overexpression with patients' age (p = 0.015). No statistically significant correlation was identified between t-FAK staining intensity, t-Src positivity, overexpression or staining intensity and any of the clinicopathological parameters tested. No significant correlation was found between neither the positivity nor the intensity of staining of either p-FAk or p-Src with any of the parameters under study. Nonetheless, important, but non-significant, trends were identified between t-FAK staining intensity, t-Src positivity and overexpression and patients' survival (log rank, p = 0.122, p = 0.090 and p = 0.057 respectively). Similarly, p-FAK and p-Src staining characteristics seemed to correlate, even though non-significantly, with patients' survival (log rank, p = 0.051 and p = 0.070 for p-FAK and p-Src expression, respectively; log rank, p = 0.134 and p = 0.110 for p-FAK and p-Src staining intensity, respectively). These results support an important potential role of FAK-Src signalling in endometrial malignant disease progress and render further research in this field a necessity.

Management of branch-duct intraductal papillary mucinous neoplasms of the pancreas: observation with MR imaging

Purpose To evaluate the clinical outcomes of conservative management by observation with MRI of patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). Materials and Methods Twenty-three consecutive patients, who were followed up by MRI with magnetic resonance cholangiopancreatography (MRCP) over a period of more than 9 months after initial MRI examinations, were enrolled in this study. On MRI, number of lesions, the maximum diameter of BD-IPMNs, lesion location, the presence of associated dilatation of main pancreatic duct (MPD), the presence of enhancing mural nodules within the lesion and the presence of interval change were retrospectively reviewed on initial and follow-up MR images in consensus by two radiologists. All patients were evaluated to search for evidence of malignant progression of disease. Results The follow-up period ranged from 10 to 96 months (mean, 37 months). On initial MRI with MRCP, a total of 39 lesions were found in 23 patients. The maximum diameter of BD-IPMNs ranged between 6 and 32 mm, with a mean of 12 mm. Thirty-four lesions (87%) of 19 patients remained unchanged in the maximum diameter. Five lesions (13%) of four patients showed an increase in the maximum diameter. Enhancing mural nodules were not found in any individual, neither on the initial MRI study nor on the follow-up studies. There was no patient who had evidence of local aggressive growth of tumor or evidence of metastases to distant sites. Conclusion Our study suggests that branch-duct IPMNs without enhancing mural nodules are essentially benign and should be managed nonoperatively through observation by MRI.

Identification of genes with different methylation profiles between RAEB and RCMD in myelodysplastic syndrome.

6608 Background: Myelodysplastic syndromes (MDS) are a group of clonal hematological disorders characterized by significant prognostic heterogeneity and a preleukemic condition with transformation into acute myeloid leukemia. However, the underlying genetic events remain poorly understood. Since aberrant DNA methylation might play a causative role in disease and prognosis, the study investigated the difference of DNA methylation profiles between refractory anemia with excess blast (RAEB) and refractory cytopenia with multilineage dysplasia (RCMD). Methods: Bone marrow samples from 20 patients with primary MDS (nine RAEB and 11 RCMD) and peripheral blood samples from four controls, were assessed using a commercial whole genome-wide methylation assay. Results: The microarray data revealed statistically significant hypermethylation of 69 genes in RAEB, but not in RCMD. The candidate genes mapped to five different networks, with network 1 being the top-scoring network with functions in gene expression, cancer, and cell cycle. Five network 1 genes (GSTM5, BIK, CENPH, RERG, and ANGPTL2) were associated with disease progression in malignancy. Methylation-specific polymerase chain reaction was used to detect the methylation level of candidate gene promoters in both RAEB and RCMD. Among these genes, methylated promoters of GSTM5 (55.5% and 20%, respectively), BIK (20% and 0%, respectively), and ANGPTL2 (44.4% and 10%, respectively) occurred more frequently in RAEB than in RCMD. Conclusions: Although the functions of these genes were not revealed, DNA methylation of GSTM5, BIK and ANGPTL2 might induce epigenetic silencing and contribute to the increasing blasts, resulting in progression of MDS. No significant financial relationships to disclose.

HSP90 and its inhibitors (Review)

The HSP90 molecular chaperone family is highly conserved and expressed in various organisms ranging from prokaryotes to eukaryotes. HSP90 proteins play essential housekeeping functions, such as controlling the activity, turnover and trafficking of various proteins, promoting cell survival through maintaining the structural and functional integrity of some client proteins which control cell survival, proliferation and apoptosis, and play an important role in the progression of malignant disease. HSP90 proteins are ATP-dependent chaperones and the binding and hydrolysis of ATP are coupled to conformation changes of HSP90, which facilitate client protein folding and maturation. Many natural and synthetic molecular compounds have been proposed as promising cancer therapy via disrupting the formation of complex ATP-HSP90-client proteins.

Expression and prognostic significance of iNOS in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular tumor in adults. Disease metastasis occurs in half of the patients and is uniformly fatal despite systemic therapy. Inducible nitric oxide synthase (iNOS) is associated with disease progression in various malignancies including cutaneous melanoma. In this retrospective cohort, we examined the prognostic value of iNOS in UM by performing immunohistochemistry on paraffin-embedded sections of primary tumors (90 patients) and matched primary and metastatic hepatic tumors (19 patients) with complete histopathological and clinical data. We show that iNOS is expressed in UM (57% of the patients) and high iNOS levels significantly (p = 0.04; hazard ratio (HR) = 2.3) predict disease-specific survival (DSS) as assessed by Kaplan-Meier analysis and univariate Cox's proportional hazards regression model. Furthermore, high iNOS expression in the UM primary tissue was significantly associated with metastatic disease and vice versa. Expression of iNOS in hepatic metastases significantly (p = 0.02) predicted a shortened survival as assessed by Kaplan-Meier analysis. However, iNOS did not appear to be a significant (p = 0.16; HR = 1.9) factor in the multivariate Cox's regression analysis performed together with the clinical parameters tumor diameter, tumor cell type, and tumor location in which only tumor diameter predicted DSS. In conclusion, iNOS predicts DSS in UM and may play a role in disease progression but it is not an independent prognostic factor.

The therapeutic promise of the cancer stem cell concept

Cancer stem cells (CSCs) are a subpopulation of tumor cells that selectively possess tumor initiation and self-renewal capacity and the ability to give rise to bulk populations of nontumorigenic cancer cell progeny through differentiation. As we discuss here, they have been prospectively identified in several human malignancies, and their relative abundance in clinical cancer specimens has been correlated with malignant disease progression in human patients. Furthermore, recent findings suggest that clinical cancer progression driven by CSCs may contribute to the failure of existing therapies to consistently eradicate malignant tumors. Therefore, CSC-directed therapeutic approaches might represent translationally relevant strategies to improve clinical cancer therapy, in particular for those malignancies that are currently refractory to conventional anticancer agents directed predominantly at tumor bulk populations.

Cancer stem cells as new therapeutic target to prevent tumour progression and metastasis

Over the past decade, increasing evidence suggested that stem cells play a crucial role not only in the generation of complex multicellular organisms, but also in the development and progression of malignant diseases. For the most abundant tumours, it has been shown that they contain a subset of distinct cancer cells that is exclusively responsible for tumour initiation and propagation These cells are termed cancer stem cells or tumour-initiating cells and they are also highly resistant to chemotherapeutic agents. Because CSC are preferentially endowed with the self-renewal capacity, it has further been hypothesized that they are also exclusively responsible for metastasis. Indeed, we were able to show that pancreatic cancer stem cells contain a subpopulation of migrating cancer stem cells characterized by CXCR4 co-expression. Only these cells are capable of evading the primary tumour and metastasizing. Laboratories around the world are now aiming to further characterize these cells to eventually identify novel treatment modalities to fight cancer. Thus, cancer stem cells are promising new targets to counteract the growth-promoting and metastatic potential of solid tumours.

Deregulation of EZH2 expression in human spermatogenic disorders and testicular germ cell tumors

Enhancer of Zeste 2 (EZH2) is an epigenetic transcriptional repressor involved in cell cycle control and cell fate decisions. Since these processes play key roles during intact spermatogenesis, deregulation of EZH2 expression may contribute to the development and progression of benign and malignant testicular diseases. The objective of this study was to investigate the expression profile of EZH2 in testicular germ cell tumors (TGCT) and spermatogenic defects. Real-time RT-PCR was applied to quantify the m-RNA expression of EZH2 in 64 seminomas 36 non-seminomas, 4 carcinomas in situ (CIS), 40 samples harboring impaired spermatogenesis and 24 normal testicular reference biopsies. EZH2 was expressed in 99% of TGCT samples and in all biopsies with intact spermatogenesis. Its expression levels were highest in normal testicular tissue, and continuously decreased with malignant transformation to CIS and further progression to invasive TGCT (P<0.001). EZH2 tumor levels were not related to the histological TGCT subtype or clinical tumor stage. Comparison of distinct stages of spermatogenic failure revealed an inverse association of EZH2 levels to the severity of the spermatogenic defect (P<0.001). Our data strongly suggest that in TGCT EZH2 does not exert its often assumed oncogenic properties during malignant transformation and progression. High EZH2 levels in normal testicular tissue and the inverse association of its expression levels with the severity of spermatogenic failure point to its potential value as a molecular marker for spermatogenic defects and may indicate an important physiological role of EZH2 during intact spermatogenesis.

Tissue-Factor- and PSGL-1-Bearing Microparticles Are Strong Outcome Predictors in Allogeneic Stem Cell Transplantation.

Abstract 2263Poster Board II-240 ObjectiveThere is compelling evidence that increased levels of Tissue-factor (TF) and TF-bearing microparticles (MPs) as well as P-selectin and its receptor P-selectin glycoprotein ligand 1 (PSGL-1) play an important role in disease progression, angiogenesis and cancer-related coagulopathy in solid and hematologic malignancies. We therefore hypothesized that numbers of circulating TF- and PSGL-1 bearing MPs might have substantial influence on outcome in allogeneic stem cell transplantation (alloSCT). Patients and MethodsBlood samples were obtained from 33 patients with different hematologic diseases (AML=19, ALL=5, CML/MPS=2, CLL/lymphoma=2, myeloma=2, aplastic anemia=2) during the course of alloSCT at distinct time points: at admission (“start”), during conditioning therapy before anti-thymocyte globulin (ATG) infusion (“pre-ATG”), on day 3 of ATG infusion (“during-ATG”), before transplantation (“pre-Tx”), 1 h after transplantation (“post-Tx), on day 1 after transplantation (“d+1post-Tx”) and on day 1 after neutrophil engraftment (“engraftment”). Conditioning regimens included either standard therapies (n=17), FLAMSA (n=11) or other (n=5). GvHD prophylaxis consisted of either CsA/MTX/ATG (n=19), CsA/MMF/ATG (n=11) or CsA/Steroids (n=3). Typical patient and transplant risk factors were included in statistical analysis.Platelet-free plasma (PFP) was obtained by three-step centrifugation, snap-frozen in liquid nitrogen and stored at -80°C. After thawing, 50μl of PFP were resuspended in Annexin V binding or control buffer and labeled with 1μl Annxin V-Cy5 and 0.5μg of CD142-FITC (TF), CD162-FITC (PSGL-1) or isotype control. In flow cytometry MPs were gated by size (<1μm) and Annexin V positivity and Trucount tubes® were used for MP enumeration. ResultsMean follow-up time was 759 (10-1305) days. 17 (51.5%) patients died, 9 due to TRM (27.3%), and 12 (36.4%) had recurrence or progression during follow-up. Median overall survival (OS) was 815 days, median disease-free or progression survival (DFS/PFS) 440 (10-1272) days and median time to progression (TTP) 365.5 (130-1183) days.MP counts are shown in table 1. There was a significant reduction (p<0.05) for Annexin V- and PSGL-1-MPs from “start” to “pre-Tx” and an increase after transplantation while TF-MPs had significant higher numbers at “d+1post-Tx” compared to “start” values.Univariate Cox analysis identified TF-MPs at “start” (p=0.011, HR=1.006 per 1 MP/μl) and “pre-ATG” (p=0.004, HR=1.011) to be significantly associated with OS. When corrected for known risk factors, TF-MPs “pre-ATG” remained the only independent predictive parameter for OS in multivariate Cox analysis s(p=0.036, HR 1.022). A cut-off value was determined for stratification of patients by calculating the AUC of a ROC–curve (p=0.030, AUC 0.762). Thus, Patients with TF-MP values >140/μl showed a significantly shorter survival time (p=0.007; mean OS: 469.4±160.0 vs. 1038.5±110.3 days). Same was done for DFS/PFS and again TF-MP values >140/μl were predictive of worse DFS/PFS (p=0.020, HR=3.61) in multivariate Cox regression with a shortened DFS/PFS (p=0.013; mean: 350.9±113.8 vs. 852.5±129.6 days). These findings were caused by an increased treatment-related mortality (TRM) with a cumulative incidence at 1 year of 55.5% vs. 13.3% for corresponding TF-MP groups (p=0.029). TRM was caused by infection (n=4), VOD (n=2) or other reasons (n=3). There was no significant association with relapse or acute GvHD.Furthermore, we found PSGL-1-MP counts below 250/μl “post-Tx” (and on “engraftment”) to be a significant predictor of relapse/progression (p=0.044, HR=4.91) with a cumulative incidence at 3 years of 81% (95%-CI: 61.9-100) vs. 11.1% (95%-CI: 1.8-70.5) and a mean TTP of 602±106.1 vs. 1140±104.5 days (p=0.027). ConclusionsTF-bearing MPs before and during conditioning therapy are prognostic markers of OS and DFS/PFS due to increased TRM while PSGL-1 bearing MPs after transplantation and at engraftment predict relapse/progression and TTP. Course of MP counts suggests increased TF-MP release by monocytes, endothelial and stromal cell while significant differences in PSGL-1-MPs might rather be graft-related. [Display omitted] Disclosures:Trummer:CSL Behring: Research Funding.

Current status of mucins in the diagnosis and therapy of cancer

Mucins are the most abundant high molecular weight glycoproteins in mucus. Their nature and glycosylation content dictates the biochemical and biophysical properties of viscoelastic secretions, pointing out an important role in diverse biological functions, such as differentiation, cell adhesions, immune responses, and cell signaling. Mucins are expressed in tubular organs by specialized epithelial cells in the body. Their aberrant expression is well documented in a variety of inflammatory or malignant diseases. From a prognosis point of view, their expression and alterations in glycosylation are associated with the development and progression of malignant diseases. Therefore, mucins can be used as valuable markers to distinguish between normal and disease conditions. Indeed, this alteration in glycosylation patterns generates several epitopes in the oligosaccharide side chains that can be used as diagnostic and/or prognostic markers. Furthermore, these characteristic tumor-associated epitopes are extensively used as appropriate immunotargets of malignant epithelial cells. Therefore, in an effort to detect and treat cancer at the earliest stage possible, mucins are analyzed as potential markers of disease for diagnosis, progression, and for therapeutic purposes. In this review, we focused on the current status of the distribution of mucins in normal and pathologic conditions and their clinical use both in cancer diagnosis and therapeutics treatments.

The Interferon Consensus Sequence Binding Protein (ICSBP/IRF8) Activates Transcription of the FANCF Gene during Myeloid Differentiation

The interferon consensus sequence binding protein (ICSBP) is an interferon regulatory transcription factor with leukemia-suppressor activity. ICSBP regulates genes that are involved in phagocyte function, proliferation, and apoptosis. In murine models ICSBP deficiency results in a myeloproliferative disorder (MPD) with increased mature neutrophils. Over time this MPD progresses to acute myeloid leukemia (AML), suggesting that ICSBP deficiency is adequate for MPD, but additional genetic lesions are required for AML. The hypothesis of these studies is that dysregulation of key target genes predisposes to disease progression under conditions of decreased ICSBP expression. To investigate this hypothesis, we used chromatin co-immunoprecipitation to identify genes involved the ICSBP-leukemia suppressor effect. In the current studies, we identify the gene encoding Fanconi F (FANCF) as an ICSBP target gene. FancF participates in a repair of cross-linked DNA. We identify a FANCF promoter cis element, which is activated by ICSBP in differentiating myeloid cells. We also determine that DNA cross-link repair is impaired in ICSBP-deficient myeloid cells in a FancF-dependent manner. This effect is observed in differentiating cells, suggesting that ICSBP protects against the genotoxic stress of myelopoiesis. Decreased ICSBP expression is found in human AML and chronic myeloid leukemia during blast crisis (CML-BC). Our studies suggest that ICSBP deficiency may be functionally important for accumulation of chromosomal abnormalities during disease progression in these myeloid malignancies.

Cancer stem cells and the cellular hierarchy in haematological malignancies

Malignancies in the haematopoietic system seem to depend on a small subset of so-called cancer stem cells (CSC) for their continued growth and progression – this was first described as the “sleeper-feeder theory” for leukaemia. The leukaemia stem cell was the first of such subsets to be described although the origins of these cells have been difficult to dissect. Consequently, their biology is not fully elucidated, which also holds true for the normal-tissue counterparts. The stem cell concept describes stem cells to be of low frequency, self renewing and with multilineage potential based on phenomenology – a definition which may not hold strictly true for CSCs when studied in animals and humans in vivo and in vitro. Several studies have analysed the cellular hierarchy of the haematopoietic system by cell sorting of few and even single cells, tracking acquired genetic changes and performing transplantation model studies to document subsets within the differentiating hierarchy as potential CSC compartments. In leukaemia the CSC has been described in the bone marrow compartment of haematopoietic stem cells (HSC); however, in other bone marrow disorders like multiple myeloma it is likely that the cell of origin is a more differentiated cell, like post-germinal memory B cells or plasmablasts. Studies performed so far have even indicated that the genetic events may occur in different B cell subsets in accordance with the stepwise oncogenesis of the disease. Although our understanding of the nature and biology of these initiating cells remains unknown, the obvious existence of such cells has implications for understanding initial malignant transformation and disease metastasis or progression and, most important, the selection of individualised therapeutic strategies targeting the subsets harbouring the CSC function. In the present review on stem cells in haematological malignancies we have focused on two topics, first, describing the stem cell concept in health and disease, and its “phenomenology”, and second, describing the CSC compartments in leukaemia and multiple myeloma.

The regulation of proliferation and invasion in differentiated thyroid cancer by growth factors.

Invasion and metastasis are the primary cause of death in patients with follicular thyroid cancer (FTC). The thyroid is a micro-economic system in which proliferation and differentiation was supposed to be under the major control of only a single hormone (thyroid stimulating hormone-TSH). It has shown, however, that a complex network of various growth factors regulates growth and invasion of thyroid cancer cells. A growing literature has established the close association between malignant tumor progression and growth regulatory aberrations in cancer cells. Most of these studies have focused on the phenomenon, that advanced and more aggressive tumors or metastases lost the sensitivity to growth inhibitors, such as transforming growth factor beta. These findings highlight two aberrations of growth regulation which may favour progression of malignant disease and acquisition of metastatic competence: (1) Resistance to growth factor inhibitors and (2) growth autonomy of metastatic follicular thyroid cancer cells.

Cisterna chyli in patients with malignancy—Is there a correlation between changes in cisterna volume and progression or regression of the tumor?

The purpose of this study was to investigate the potential correlation between the size of the cisterna chyli (CC) and the tumor size in patients with malignancies on computed tomography (CT). Materials and methods Out of a 3000 patient cohort 138 patients with histologically confirmed malignant disease, a detectable CC on CT and at least two CT scans within a 6 month period were included in this retrospective study. Out of 525 scans a total of 711 lesion intervals were evaluated. The volume of the CC and all target lesions (up to three per scan) were recorded. The Pearson correlation coefficient for the two parameters of changes in lesion size and CC size was calculated for the whole cohort and for a 33 patient subgroup that included only patients with tumors that showed the closest association with large CC in a previous study. Results The mean difference in lesion size for all 711 intervals was −1165 μl. The mean difference in CC size for all 711 intervals was −46.6 μl. The respective Pearson correlation coefficient was .05 with a non-significant p-value of .1823 (subgroup: r = .04, p = .6358). Conclusion No significant correlation between the progression or regression of malignant disease and the size of the cisterna chyli could be found.

Dyspnea in oncologic patients as an important cause of attendance in emergency room

e20705 Background: Attending oncologic patients in emergency room because of a large variety of symptoms due to treatments or tumor complications is very common. Our objective is to estimate the prevalence of dyspnea in oncologic patients and its etiology. Methods: From October 2007 to October 2008 we recollected 560 oncologic patients who were seen on Emergency room. It was revised cause of consultation, tumors´ location and stage, active or palliative care, diagnosis and treatment. Results: 71 of the 560 patients (12.7%) related dyspnea as cause of consultation, being the third cause of attendance in Emergency room after pain (126 patients, 22.5%) and fever (98 patients, 17.5%). The most common tumor´s location was lung in 38 of the 71 patients (53.52%), followed by colorectal cancer (11.3%) and breast (9.9%). 76.8% were advanced oncologic patients (stage IV). Diagnosis was respiratory infection in 19 patients (26.8 %) followed by malignant pleural bleeding (10 patients, 14.1%), disease progression (9 patients, 12.7%) and pulmonary embolism (5 patients, 7%). Dyspnea was a multifactorial symptom in 21 of the 71 patients (29.6%) without an etiological diagnosis. In 47 patients (66.2%) was required admission with a mortal evolution in more than 50%. Conclusions: In oncologic patients dyspnea is a frequent cause of consultation in Emergency room with high rates of morbility and mortality. It affects to patients´quality of life. When etiology is diagnosed the most common is respiratory infection. We should make an effort to offer the best supportive care. No significant financial relationships to disclose.