De novo loss-of-function variants in STAG2 are associated with developmental delay, microcephaly, and congenital anomalies.

The cohesin complex is an evolutionarily conserved multi-subunit protein complex which regulates sister chromatid cohesion during mitosis and meiosis. Additionally, the cohesin complex regulates DNA replication, DNA repair, and transcription. The core of the complex consists of four subunits: SMC1A, SMC3, RAD21, and STAG1/2. Loss-of-function mutations in many of these proteins have been implicated in human developmental disorders collectively termed "cohesinopathies." Through clinical exome sequencing (CES) of an 8-year-old girl with a clinical history of global developmental delay, microcephaly, microtia with hearing loss, language delay, ADHD, and dysmorphic features, we describe a heterozygous de novo variant (c.205C>T; p.(Arg69*)) in the integral cohesin structural protein, STAG2. This variant is associated with decreased STAG2 protein expression. The analyses of metaphase spreads did not exhibit premature sister chromatid separation; however, delayed sister chromatid cohesion was observed. To further support the pathogenicity of STAG2 variants, we identified two additional female cases from the DECIPHER research database with mutations in STAG2 and phenotypes similar to our patient. Interestingly, the clinical features of these three cases are remarkably similar to those observed in other well-established cohesinopathies. Herein, we suggest that STAG2 is a dosage-sensitive gene and that heterozygous loss-of-function variants lead to a cohesinopathy.

Label-free enumeration, collection and downstream cytological and cytogenetic analysis of circulating tumor cells.

Circulating tumor cells (CTCs) have a great potential as indicators of metastatic disease that may help physicians improve cancer prognostication, treatment and patient outcomes. Heterogeneous marker expression as well as the complexity of current antibody-based isolation and analysis systems highlights the need for alternative methods. In this work, we use a microfluidic Vortex device that can selectively isolate potential tumor cells from blood independent of cell surface expression. This system was adapted to interface with three protein-marker-free analysis techniques: (i) an in-flow automated image processing system to enumerate cells released, (ii) cytological analysis using Papanicolaou (Pap) staining and (iii) fluorescence in situ hybridization (FISH) targeting the ALK rearrangement. In-flow counting enables a rapid assessment of the cancer-associated large circulating cells in a sample within minutes to determine whether standard downstream assays such as cytological and cytogenetic analyses that are more time consuming and costly are warranted. Using our platform integrated with these workflows, we analyzed 32 non-small cell lung cancer (NSCLC) and 22 breast cancer patient samples, yielding 60 to 100% of the cancer patients with a cell count over the healthy threshold, depending on the detection method used: respectively 77.8% for automated, 60-100% for cytology, and 80% for immunostaining based enumeration.

An unusual initial presentation of mantle cell lymphoma arising from the lymphoid stroma of warthin tumor.

BACKGROUND: Warthin tumors presenting concomitantly with a lymphoma is vanishingly rare with only 15 reported cases in English literature. Herein, we report an unusual initial presentation of a mantle cell lymphoma involving the lymphoid stroma of a Warthin tumor. CASE PRESENTATION: A seventy-seven year old otherwise healthy gentleman with a 50-pack year smoking history presents with a slowly enlarging left cheek mass. CT scan of the neck demonstrated a left parotid gland tumor measuring 3.4 cm in greatest dimension. He underwent a left superficial parotidectomy, with subsequent histopathologic examination revealing a Warthin tumor with extensive expansion of the lymphoid stroma. Flow cytometric, immunohistochemical, and cytogenetic studies of the stromal component of the tumor confirmed the presence of a mantle cell lymphoma. Clinical staging demonstrated stage IVa disease, and was considered to be at low to intermediate risk due to the slow growth of the parotid lesion. The patient is undergoing close follow up with repeat PET-CT scans at six months. CONCLUSION: To the best of our knowledge, this is the first well documented collision tumor between mantle cell lymphoma and a Warthin tumor. This case also brings to light the significance of thorough evaluation of the lymphoid component of Warthin tumor.

A Cryptic t(11;14) Translocation in Mantle Cell Lymphoma Highlights the Importance of FISH.

Mantle cell lymphoma (MCL) is a mature B-cell neoplasm composed of monomorphic small to medium-sized atypical lymphocytes arising from naïve mantle zone B-cells, with a generally aggressive and incurable clinical course. The t(11;14)(q13;q32) between IGH@ and CCND1 is present in almost all cases of MCL. Secondary cytogenetic abnormalities are common, and have been associated in some cases with clinical progression. Variant and cryptic t(11;14) translocations have been reported as well. Herein, we present the case of an 80-year old woman with classical MCL, and a cryptic t(11;14) translocation detected by fluorescence in situ hybridization (FISH), and not by conventional cytogenetics. FISH on previously G-banded metaphases showed a cryptic CCND1-IGH@ fusion signal on a derivative chromosome 10, and another fusion signal on one of the abnormal copies of chromosome 11. Cases such as this highlight the importance of FISH studies as part of an algorithmic and multidisciplinary approach to diagnosis.

Novel three-dimensional in vitro models of ovarian endometriosis.

BACKGROUND: Endometriosis is characterized by the presence of functional endometrial tissue outside of the uterine cavity. It affects 1 in 10 women of reproductive age. This chronic condition commonly leads to consequences such as pelvic pain, dysmenorrhea, infertility and an elevated risk of epithelial ovarian cancer. Despite the prevalence of endometriosis and its impact on women's lives, there are relatively few in vitro and in vivo models available for studying the complex disease biology, pathophysiology, and for use in the preclinical development of novel therapies. The goal of this study was to develop a novel three-dimensional (3D) cell culture model of ovarian endometriosis and to test whether it is more reflective of endometriosis biology than traditional two dimensional (2D) monolayer cultures. METHODS: A novel ovarian endometriosis epithelial cell line (EEC16) was isolated from a 34-year old female with severe endometriosis. After characterization of cells using in vitro assays, western blotting and RNA-sequencing, this cell line and a second, already well characterized endometriosis cell line, EEC12Z, were established as in vitro 3D spheroid models. We compared biological features of 3D spheroids to 2D cultures and human endometriosis lesions using immunohistochemistry and real-time semi-quantitative PCR. RESULTS: In comparison to normal ovarian epithelial cells, EEC16 displayed features of neoplastic transformation in in vitro assays. When cultured in 3D, EEC16 and EEC12Z showed differential expression of endometriosis-associated genes compared to 2D monolayer cultures, and more closely mimicked the molecular and histological features of human endometriosis lesions. CONCLUSIONS: To our knowledge, this represents the first report of an in vitro spheroid model of endometriosis. 3D endometriosis models represent valuable experimental tools for studying EEC biology and the development of novel therapeutic approaches.

One in four individuals of African-American ancestry harbors a 5.5kb deletion at chromosome 11q13.1.

Cloning and sequencing of 5.5 kb deletion at chromosome 11q13.1 from the HeLa cells, tumorigenic hybrids and two fibroblast cell lines have revealed homologous recombination between AluSx and AluY resulting in the deletion of intervening sequences. Long-range PCR of the 5.5 kb sequence in 494 normal lymphocyte samples showed heterozygous deletion in 28.3% of African-American ancestry samples but only in 4.8% of Caucasian samples (p<0.0001). This observation is strengthened by the copy number variation (CNV) data of the HapMap samples which showed that this deletion occurs in 27% of YRI (Yoruba--West African) population but none in non-African populations. The HapMap analysis further identified strong linkage disequilibrium between 5 single nucleotide polymorphisms and the 5.5 kb deletion in people of African ancestry. Computational analysis of 175 kb sequence surrounding the deletion site revealed enhanced flexibility, low thermodynamic stability, high repetitiveness, and stable stem-loop/hairpin secondary structures that are hallmarks of common fragile sites.

Correction: The CD44high Tumorigenic Subsets in Lung Cancer Biospecimens Are Enriched for Low miR-34a Expression.

[This corrects the article on p. e73195 in vol. 8.].

Heterogeneity of monosomy 3 in fine needle aspiration biopsy of choroidal melanoma.

PURPOSE: To report on the heterogeneity of monosomy 3 in a fine needle aspiration biopsy obtained transsclerally from choroidal melanoma for prognosis. METHODS: All clinical records for patients who had been diagnosed with choroidal melanoma and underwent iodine-125 plaque brachytherapy with intraoperative transscleral fine needle aspiration biopsy from January 2005 to August 20, 2011, and who had a positive result for monosomy 3 according to fluorescence in situ hybridization as reported by clinical cytogenetics testing were collected. Patient age and sex, total number of cells evaluated and number of cells positive for monosomy 3, tumor size, and metastatic outcome were recorded for each patient. RESULTS: A positive result for monosomy 3 was reported in 93 patients who underwent transscleral fine needle aspiration biopsy. Two patients were lost to follow-up immediately post-operatively, and the remaining 91 patients were included in this study. The mean number of cells evaluated in the biopsy was 273 (range 28 to 520). The mean percentage of cells positive for monosomy 3 was 62.9% (range 4.7%-100%). The mean tumor height was 5.91 mm (range 1.99 to 10.85 mm). Larger tumors were associated with a higher percentage of cells positive for monosomy 3. During the average follow-up interval of 28.9 months (range 3-76 months), choroidal melanoma metastasis developed in 18 (20%) patients. Patients whose tumors had 1%-33% of cells positive for monosomy 3 had a significantly lower risk of metastasis-related death compared to patients whose tumors harbored a higher percentage of monosomy 3 (p = 0.04). CONCLUSIONS: Cytogenetic heterogeneity of fluorescent in situ hybridization for monosomy 3 exists in a biopsy sample. Larger tumors were more likely to have a higher percentage of monosomy 3 positive cells in the sample. Furthermore, patients whose tumors had more than 33% of cells positive for monosomy 3 had a poorer prognosis than patients whose tumors had lower percentages of monosomy 3.

The CD44(high) tumorigenic subsets in lung cancer biospecimens are enriched for low miR-34a expression.

Cellular heterogeneity is an integral part of cancer development and progression. Progression can be associated with emergence of cells that exhibit high phenotypic plasticity (including "de-differentiation" to primitive developmental states), and aggressive behavioral properties (including high tumorigenic potentials). We observed that many biomarkers that are used to identify Cancer Stem Cells (CSC) can label cell subsets in an advanced clinical stage of lung cancer (malignant pleural effusions, or MPE). Thus, CSC-biomarkers may be useful for live sorting functionally distinct cell subsets from individual tumors, which may enable investigators to hone in on the molecular basis for functional heterogeneity. We demonstrate that the CD44(hi) (CD44-high) cancer cell subsets display higher clonal, colony forming potential than CD44(lo) cells (n=3) and are also tumorigenic (n=2/2) when transplanted in mouse xenograft model. The CD44(hi) subsets express different levels of embryonal (de-differentiation) markers or chromatin regulators. In archived lung cancer tissues, ALDH markers co-localize more with CD44 in squamous cell carcinoma (n=5/7) than Adeno Carcinoma (n=1/12). MPE cancer cells and a lung cancer cell line (NCI-H-2122) exhibit chromosomal abnormalities and 1p36 deletion (n=3/3). Since miR-34a maps to the 1p36 deletion site, low miR-34a expression levels were detected in these cells. The colony forming efficiency of CD44(hi) cells, characteristic property of CSC, can be inhibited by mir-34a replacement in these samples. In addition the highly tumorigenic CD44(hi) cells are enriched for cells in the G2 phase of cell cycle.

The role of miRNA in inflammation and autoimmunity.

miRNAs are small non-coding RNA molecules that modulate the expression of multiple protein-encoding genes at the post-transcriptional level. They have recently been recognized as powerful regulators of numerous genes and pathways in the pathogenesis of inflammatory and autoimmune diseases. The targets of most miRNAs remain unknown and their roles in biological processes such as cell differentiation, proliferation, and death (apoptosis) are not clearly understood. In this review we will discuss how certain candidate miRNAs affect inflammatory and immune mediated diseases by regulating their cellular and molecular targets. We focused the influence of gender and sex hormones on miRNA. We believe that understanding the role of miRNAs could shed light on the cause and progression of many inflammatory and autoimmune diseases and eventually lay the groundwork for therapeutic options.

HOXB7 promotes invasion and predicts survival in pancreatic adenocarcinoma.

BACKGROUND: The homeobox gene HOXB7 is overexpressed across a range of cancers and promotes tumorigenesis through varying effects on proliferation, survival, invasion, and angiogenesis. Although published microarray data suggest HOXB7 is overexpressed in pancreatic ductal adenocarcinoma (PDAC), its function in pancreatic cancer has not been studied. METHODS: HOXB7 message and protein levels were examined in PDAC cell lines and patient samples, as well as in normal pancreas. HOXB7 protein expression in patient tumors was determined by immunohistochemistry and correlated with clinicopathologic factors and survival. The impact of HOXB7 on cell proliferation, growth, and invasion was assessed by knockdown and overexpression in PDAC cell lines. Candidate genes whose expression levels were altered following HOXB7 knockdown were determined by microarray analysis. RESULTS: HOXB7 message and protein levels were significantly elevated in PDAC cell lines and patient tumor samples relative to normal pancreas. Evaluation of a tissue microarray of 145 resected PDACs found high HOXB7 protein expression was correlated with lymph node metastasis (P = .034) and an independent predictor of worse overall survival in multivariate analysis (hazard ratio = 1.56, 95% confidence interval = 1.02-2.39). HOXB7 knockdown or overexpression in PDAC cell lines resulted in decreased or increased invasion, respectively, without influencing proliferation or cell viability. CONCLUSIONS: HOXB7 is frequently overexpressed in PDAC, specifically promotes invasive phenotype, and is associated with lymph node metastasis and worse survival outcome. HOXB7 and its downstream targets may represent novel clinical biomarkers or targets of therapy for inhibiting the invasive and metastatic capacity of PDAC.

Combined preconditioning and in vivo chemoselection with 6-thioguanine alone achieves highly efficient reconstitution of normal hematopoiesis with HPRT-deficient bone marrow.

Purine analogs such as 6-thioguanine (6TG) cause myelotoxicity upon conversion into nucleotides by hypoxanthine-guanine phosphoribosyltransferase (HPRT). Here we have developed a novel and highly efficient strategy employing 6TG as a single agent for both conditioning and in vivo chemoselection of HPRT-deficient hematopoietic stem cells. The dose-response and time course of 6TG myelotoxicity were first compared in HPRT wild-type mice and HPRT-deficient transgenic mice. Dosage and schedule parameters were optimized to employ 6TG for myelosuppressive conditioning, immediately followed by in vivo chemoselection of HPRT-deficient transgenic donor bone marrow (BM) transplanted into syngeneic HPRT wild-type recipients. At appropriate doses, 6TG induced selective myelotoxicity without any adverse effects on extrahematopoietic tissues in HPRT wild-type mice, while hematopoietic stem cells deficient in HPRT activity were highly resistant to its cytotoxic effects. Combined 6TG conditioning and post-transplantation chemoselection consistently achieved ∼95% engraftment of HPRT-deficient donor BM, with low overall toxicity. Long-term reconstitution of immunophenotypically normal BM was achieved in both primary and secondary recipients. Our results provide proof-of-concept that single-agent 6TG can be used for both myelosuppressive conditioning without requiring irradiation and for in vivo chemoselection of HPRT-deficient donor cells. Our results show that by applying the myelosuppressive effects of 6TG both before (as conditioning) and after transplantation (as chemoselection), highly efficient engraftment of HPRT-deficient hematopoietic stem cells can be achieved.

Clear cell renal cell carcinoma: multiphasic multidetector CT imaging features help predict genetic karyotypes.

PURPOSE: To determine whether imaging characteristics at multiphasic multidetector computed tomography (CT) correlate with common karyotypic abnormalities in patients with clear cell renal cell carcinomas (ccRCCs). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was waived for this HIPAA-compliant retrospective study. From January 2000 through September 2007, the prenephrectomy multiphasic (corticomedullary, nephrographic, and excretory phases), multidetector helical CT images of 58 histologically proved and karyotyped ccRCCs were reviewed by two readers with experience in abdominal imaging. Imaging features assessed included degree of attenuation, contour, and presence of calcifications and neovascularity. These features were independently correlated with specific karyotypic abnormalities on the resected specimens. Degree of attenuation data were analyzed with logistic regression for significance (P < .05), and morphologic characteristics were analyzed with odds ratios for assessing their diagnostic power. RESULTS: On unenhanced scans, 7% (two of 28) of ccRCCs with the loss of chromosome 3p were calcified, whereas 37% (11 of 30) of lesions without this anomaly were calcified (odds ratio, 0.13). During the corticomedullary phase, ccRCCs with the loss of chromosome Y enhanced more than those without this anomaly (130.0 vs 102.5 HU, P = .04), and ccRCCs with trisomy 7 enhanced less than those without this anomaly (105.8 vs 139.3 HU, P = .04). During the excretory phase, ccRCCs with trisomy 5 enhanced more than those without this anomaly (115.5 vs 83.4 HU, P = .03). CONCLUSION: The genetic makeup of ccRCCs affects their imaging features at multidetector CT examinations. Multidetector CT imaging characteristics may help suggest differences at the cytogenetic level among ccRCCs.

Coexistence of translocation(1,19) and the Philadelphia chromosome in a child's first presentation of chronic myeloid leukemia in blast crisis treated with dasatinib.

Chronic myelogenous leukemia (CML) constitutes less than 5% of childhood leukemias. The authors describe a rare case of a 14-year-old boy who presented with CML in blast crisis. Unique to this patient was the evidence of both breakpoint cluster region-c-abl oncogene 1 (BCR-ABL1) fusions as well as an additional unbalanced t(1;19) translocation. This combination has not previously been reported in the same patient. Initial treatment with dasatinib achieved a complete cytogenetic response within 2 months of therapy. This case highlights the heterogeneous presentation of CML in children and rationale for use of dasatinib as a first-line agent for patients with blast crisis.

Characterization of three cell lines derived from fine needle biopsy of choroidal melanoma with metastatic outcome.

PURPOSE: To report three low-passage cell lines from primary choroidal melanoma with metastatic outcome, which were stable for cytogenetic patterns and expression profiles of the primary melanoma. METHODS: In patients with choroidal melanoma, transscleral fine needle aspiration biopsy (FNAB) was performed immediately before plaque placement for (125)iodine brachytherapy or immediately after enucleation. Cells were examined for cytopathology, evaluated by fluorescence in-situ hybridization (FISH) for the centromere of chromosome 3, analyzed by 250K whole genome Mapping Array and U133 plus 2.0 Expression Array, and placed in cell culture. At passage 3, the cell lines were analyzed by Mapping Array and Expression Array. RESULTS: Three cell lines were propagated from primary choroidal melanomas in three patients who subsequently developed metastasis. Two cell lines were stable for the entire chromosomal aberration pattern of the respective primary tumor. In the third, necrotic material from the biopsy prevented further analysis, yet resulted in a stable cell line. Each cell line had chromosome 3 loss, 6q loss, 8p loss, multiple 8q gain, and 16q loss. Additionally, two cell lines had chromosome 6p gain. Two cell lines had RNA expression profiles similar to the respective primary tumors; the third cell line had a similar RNA expression profile relative to the other two cell lines. CONCLUSIONS: FNAB of primary choroidal melanomas resulted in highly characterized, low-passage cell lines, which were stable for the cytogenetic patterns and expression profiles found in the primary tumor. These cell lines represent novel tools for the study of metastatic choroidal melanoma biology.

Identification of candidate tumor oncogenes by integrative molecular analysis of choroidal melanoma fine-needle aspiration biopsy specimens.

OBJECTIVE: To report integrative molecular analysis of choroidal melanoma fine-needle aspiration biopsy specimens to identify candidate tumor oncogenes. METHODS: Thirty-one choroidal melanoma fine-needle aspiration biopsy specimens were analyzed using cytopathologic diagnosis of melanoma, fluorescence in situ hybridization for chromosome 3, cytogenetic characterization (GeneChip Human 250K NSPI Mapping Arrays; Affymetrix, Santa Clara, California), and gene expression profiles (GeneChip Human Genome U133 Plus 2.0 Arrays, Affymetrix). These analyses were performed by clustering of cytogenetic aberrations, sorting by chromosome 3 loss and chromosome 6p gain, and comparing gene expression profiles in chromosome 3 loss- and chromosome 6p-gain tumors to identify genes with differential expression based on cytogenetic characteristics. RESULTS: Of 31 choroidal melanoma biopsy specimens included in this study, 19 tumors had chromosome 3 loss, and 12 tumors without chromosome 3 loss had chromosome 6p gain. Comparative RNA analysis for these 2 groups revealed 49 genes with greater than 4-fold higher expression and 31 genes with greater than 4-fold lower expression in chromosome 3-loss tumors relative to chromosome 6p-gain tumors. CONCLUSIONS: Molecular analysis of choroidal melanoma fine-needle aspiration biopsy specimens demonstrated 2 cytogenetically distinct groups characterized by chromosome 3 loss or chromosome 6p gain. In chromosome 3-loss melanomas relative to chromosome 6p-gain melanomas, integrative RNA analysis revealed genes with higher expression and lower expression and identified several genes that have not been reported in previous studies. CLINICAL RELEVANCE: Genes differentially expressed between chromosome 3-loss and chromosome 6p-gain melanomas may provide new knowledge about the biologic nature of choroidal melanoma and may contribute to the development of targeted therapies.

Pleomorphic malignant fibrous histiocytoma/undifferentiated high-grade pleomorphic sarcoma of the scrotum in a patient presenting as fournier gangrene: a case report.

Pleomorphic malignant fibrous histiocytoma (MFH), also known as undifferentiated high-grade pleomorphic sarcoma according to the latest World Health Organization classification, is a diagnosis of exclusion and extremely rare in adult scrotal/paratesticular region. Clinical presentation of scrotal/paratesticular pleomorphic MFH is usually a painless and gradual scrotal swelling. We report a case of scrotal MFH in a 63-year-old man who presented as Fournier gangrene after 10-month painful scrotal swelling and multiple procedures. The specimen of emergent debridement was submitted for pathologic and bacteriologic examination. Microscopically, the lesion had marked architectural and cytologic pleomorphism. The neoplastic cells were positive for vimentin, but negative for all lineage-specific markers. Fluorescence in-situ hybridization showed an aneuploid karyotype and negative results for lipomatous tumor abnormalities. Bacterial cultures of the specimen showed extensive growth of virulent polymicrobes. The diagnosis of scrotal/paratesticular pleomorphic MFH with concurrent Fournier gangrene was made. Thoracic computed tomography scan showed bilateral multiple pulmonary nodules. The patient died 1 month later.

Cytogenetic and molecular tumor profiling for type 1 and type 2 papillary renal cell carcinoma.

PURPOSE: The goal of this study was to evaluate immunohistochemical and cytogenetic features and their prognostic value in papillary renal cell carcinoma (PRCC) subtypes. EXPERIMENTAL DESIGN: One hundred fifty-eight cases of PRCC were identified and reclassified by subtype. Tumoral expression of 29 molecular markers was determined by immunohistochemistry. Cytogenetic analyses were done on a prospective series of 65 patients. Associations with clinicopathologic information and disease-specific survival were assessed. RESULTS: Fifty-one patients (32%) had type 1 and 107 (68%) type 2 PRCC. Type 2 patients had worse Eastern Cooperative Oncology Group performance status, higher T stages, nodal and distant metastases, higher grades, and a higher frequency of necrosis, collecting system invasion and sarcomatoid features. Type 2 showed greater expression of vascular endothelial growth factor (VEGF)-R2 in the tumor epithelium, and of VEGF-R3 in both tumor epithelium and endothelium. Loss of chromosome 1p, loss of 3p, and gain of 5q were exclusively observed in type 2, whereas type 1 more frequently had trisomy 17. Type 2 PRCC was associated with worse survival than type 1, but type was not retained as an independent prognostic factor. Lower PTEN, lower EpCAM, lower gelsolin, higher CAIX, and higher VEGF-R2 and VEGF-R3 expression, loss of 1p, 3p, or 9p, and absence trisomy 17 were all associated with poorer prognosis. CONCLUSIONS: Type 2 PRCC is associated with more aggressive clinicopathologic features and worse outcome. Molecular and chromosomal alterations can distinguish between PRCC subtypes and influence their prognosis. The effect of 3p loss on survival in PRCC is opposite to the relationship seen in clear cell RCC.

Prostate-specific membrane antigen associates with anaphase-promoting complex and induces chromosomal instability.

Prostate-specific membrane antigen (PSMA) is a transmembrane protein highly expressed in advanced and metastatic prostate cancers. The pathologic consequence of elevated PSMA expression in not known. Here, we report that PSMA is localized to a membrane compartment in the vicinity of mitotic spindle poles and associates with the anaphase-promoting complex (APC). PSMA-expressing cells prematurely degrade cyclin B and exit mitosis due to increased APC activity and incomplete inactivation of APC by the spindle assembly checkpoint. Further, expression of PSMA in a karyotypically stable cell line induces aneuploidy. Thus, these findings provide the first evidence that PSMA has a causal role in the induction of aneuploidy and might play an etiologic role in the progression of prostate cancer.

Megakaryocytic blast crisis as a presenting manifestation of chronic myeloid leukemia.

Acute megakaryocytic leukemia is a rare form of acute myelogenous leukemia and may occur either de novo or by transformation of a preexisting myelodysplastic or myeloproliferative process including blast crisis of chronic myeloid leukemia (CML). Megakaryocytic blast crisis as the presenting manifestation of CML is extremely rare. We describe such a patient with no prior hematologic disease who presented with acute megakaryoblastic leukemia and extramedullary involvement, in whom the leukemic cells carried the BCR-ABL1 translocation as part of a complex karyotype. Using targeted sequential fluorescence in situ hybridization (T-FISH) technique, we detected two copies of BCR-ABL1 fusion gene in the leukemic blasts while the neutrophils carried a single copy of BCR-ABL1 fusion gene, thereby proving the origin of the megakaryoblastic leukemia from a previously undiagnosed CML clone. Blast crisis as a presenting manifestation of CML is rare and detecting clonal evolution of acute leukemia by specialized cytogenetic techniques may have important diagnostic and therapeutic implications.