Progress in understanding the biology of multiple myeloma (MM), a plasma cell malignancy, has been slow. The discovery of microRNAs (miRNAs), a class of small noncoding RNAs targeting multiple mRNAs, has revealed a new level of gene expression regulation. To determine whether miRNAs play a role in the malignant transformation of plasma cells (PCs), we have used both miRNA microarrays and quantitative real time PCR to profile miRNA expression in MM-derived cell lines (n ‫؍‬ 49) and CD138؉ bone marrow PCs from subjects with MM (n ‫؍‬ 16), monoclonal gammopathy of undetermined significance (MGUS) (n ‫؍‬ 6), and normal donors (n ‫؍‬ 6). We identified overexpression of miR-21, miR-106bϳ25 cluster, miR181a and b in MM and MGUS samples with respect to healthy PCs. Selective up-regulation of miR-32 and miR-17ϳ92 cluster was identified in MM subjects and cell lines but not in MGUS subjects or healthy PCs. Furthermore, two miRNAs, miR-19a and 19b, that are part of the miR-17ϳ92 cluster, were shown to down regulate expression of SOCS-1, a gene frequently silenced in MM that plays a critical role as inhibitor of IL-6 growth signaling. We also identified p300-CBP-associated factor , a gene involved in p53 regulation, as a bona fide target of the miR106bϳ25 cluster, miR-181a and b, and miR-32. Xenograft studies using human MM cell lines treated with miR-19a and b, and miR-181a and b antagonists resulted in significant suppression of tumor growth in nude mice. In summary, we have described a MM miRNA signature, which includes miRNAs that modulate the expression of proteins critical to myeloma pathogenesis.PCAF ͉ SOCS-1 ͉ tumor suppressor gene ͉ MGUS ͉ plasma cells

Summary In multiple myeloma (MM), an incurable B-cell neoplasm, mutation or deletion of p53 is rarely detected at diagnosis. Using small-molecule inhibitors of MDM2, we provide evidence that miR-192, 194 and 215, which are down-regulated in a subset of newly diagnosed MMs, can be transcriptionally activated by p53 and then modulate MDM2 expression. Furthermore, ectopic re-expression of these miRNAs in MM cells increases the therapeutic action of MDM2 inhibitors in vitro and in vivo by enhancing their p53-activating effects. In addition, miR-192 and 215 target the IGF pathway, preventing enhanced migration of plasma cells into bone marrow. The results suggest that these miRNAs are positive regulators of p53 and that their down-regulation plays a key role in MM development.

Diabetic autonomic neuropathies are a heterogeneous and progressive disease entity and commonly complicate both type 1 and type 2 diabetes mellitus. Although the aetiology is not entirely understood, hyperglycaemia, insulin deficiency, metabolic derangements and potentially autoimmune mechanisms are thought to play an important role. A subgroup of diabetic autonomic neuropathy, cardiovascular autonomic neuropathy (CAN), is one of the most common diabetes-associated complications and is ultimately clinically important because of its correlation with increased mortality. The natural history of CAN is unclear, but is thought to progress from a subclinical stage characterized by impaired baroreflex sensitivity and abnormalities of spectral analysis of heart rate variability to a clinically apparent stage with diverse and disabling symptoms. Early diagnosis of CAN, using spectral analysis of heart rate variability or scintigraphic imaging techniques, might enable identification of patients at highest risk for the development of clinical CAN and, thereby, enable the targeting of intensive therapeutic approaches. This Review discusses methods for diagnosis, epidemiology, natural history and potential causes and consequences of CAN.

IntroductionDysregulation of oncogenes by translocation near a strong enhancer in an immunoglobulin heavy chain (IgH) (14q32) or IgL (, 2p11 or , 22q11) locus represents a critical event in the pathogenesis of B-lymphocyte tumors. 1,2 Primary translocations usually are mediated by errors in 1 of 3 B cell-and stage-specific DNA modification mechanisms that generate double-strand breaks in genomic DNA: VDJ recombination, IgH switch recombination, and somatic hypermutation. 1,3,4 Multiple myeloma (MM) is a tumor of postgerminal center, long-lived plasma cells that have been subjected to each of these 3 DNA modification processes. We and others [5][6][7][8][9][10] have determined that IgH translocations occur in most MM tumors and that they involve a promiscuous array of nonrandom chromosomal partners and oncogenes. The 3 most frequent partner loci, each of which is involved in approximately 10% to 20% of MM tumors, include 4p16.3 (FGFR3 and MMSET), 11q13 (cyclin D1), and 16q23 (c-maf). To gain a more comprehensive insight regarding what kinds of oncogenes are dysregulated by primary immunoglobulin translocations in MM, we have continued to search for additional recurrent translocation partners.Three D-type cyclin genes encode proteins, each of which can interact with the cdk4 or the cdk6 cyclin D-dependent kinases that phosphorylate Rb, thus regulating a process that promotes the G1/S cell cycle transition. 11 Despite differences in expression patterns and in some functional properties, it appears that cyclins D1, D2, and D3 are virtually interchangeable for regulating Rb phosphorylation. [12][13][14] It is well established that dysregulation of cyclin D1 provides a primary oncogenic event in animal models and in various human tumors, including MM. [15][16][17][18][19][20][21][22][23] By contrast, despite overexpression or amplification of cyclins D2 or D3 in some human tumors, there is a paucity of compelling evidence that dysregulation of cyclins D2 or D3 are primary oncogenic events. [24][25][26][27][28][29][30][31] We report here the cytogenetic and molecular characterization of a novel partner locus at 6p21 that is translocated to the IgH or Ig locus in approximately 4% of MM tumors, and identify cyclin D3 as the apparent oncogene that is dysregulated as a consequence of these translocations. Materials and methods ProbesThe CH and CBAC, the VH cosmid probe, the 5Ј and 3Ј switch gamma (S␥) probes, and the cyclin D3 cosmid (ccnd3cy13) probe have been described elsewhere. 8,32,33 The cyclin D3 BAC (RPC11-209e18) was Cell linesThe MM cell lines used to determine the expression of cyclin D messenger RNA (mRNA) and protein included the following, as described previously 6,8,35 : RPMI-8226, ANBL6, ARK, Delta-47, EJM, Flam-76, FR4, H1112, H929, JIM-3, JJN-3, Karpas-620, KMM-1, KMS-12, KMS-18, L363, LP-1, MM.1, MM-S1, OCI-MY5, OPM-2, SKMM-1, SKMM-2, U266, UTMC-2, XG-1, XG-2, XG-5, XG-6, and XG-7. Fluorescence in situ hybridization assaysThree color fluorescence in situ hybridization (FISH) assays of metaphase chromoso...

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Several functionally important genetic elements (such as the TATA box, mRNA splice sequences, poly(A) addition signal) were first detected as short segments of unexplained sequence homology within non-coding regions of different genes. A short region of unknown sequence in the intron between the human J kappa and C kappa immunoglobulin coding regions was found to be sufficiently homologous to the corresponding segment of the mouse gene to form stable heteroduplexes. Although no specific function has yet been definitely ascribed to this region (which we call the kappa intron conserved region, or KICR), some functional significance has been inferred from the findings that (1) activation of B lymphocytes induces a DNase hypersensitivity site in this region and (2) deletions including this region reduce expression of kappa genes introduced into lymphoid cells. To delineate the KICR more precisely and to test the generality of the sequence conservation in a third species, we have sequenced this region of the human and mouse genes and have examined the corresponding region of a recently cloned rabbit kappa gene. We find a segment of about 130 base pairs (bp) that shows striking conservation in all three species, demonstrating homology significantly higher than within the C kappa coding region itself. Two short sequences from the J kappa-C kappa intron that were noted by other investigators to be homologous to proposed 'enhancer' sequences both lie within the conserved region.

OBJECTIVES The aim of this study was to determine whether short-term treatment with perhexiline improves cardiac energetics, left ventricular function, and symptoms of heart failure by altering cardiac substrate utilization.BACKGROUND Perhexiline improves exercise capacity and left ventricular ejection fraction (LVEF) in patients with

NFkB activity is critical for survival and proliferation of normal lymphoid cells and many kinds of B-cell tumors, including multiple myeloma (MM). NFkB activating mutations, which are apparent progression events, enable MM tumors to become less dependent on bone marrow signals that activate NFkB. Mutations that activate NFkB-inducing kinase (NIK) protein are the most prevalent among the many kinds of NFkB mutations in MM tumors. NIK is the main activating kinase of the alternative NFkB pathway, although over-expression of NIK also can activate the classical pathway. Two NIK inhibitors and an isomeric control were tested with human myeloma cell lines. These specific NIK inhibitors are selectively cytotoxic for cells with NIK-dependent activation of NFkB. Combination therapy targeting NIK and IKKbeta (as a main kinase of the classical NFkB pathway) represents a promising treatment strategy in MM. NIK inhibitors can also be useful tool for assessing the role of NIK and alternative NFkB pathway in different cells.