Protein kinase CK2 (CK2) has long been implicated in the regulation of cell growth and proliferation. Its activity is generally elevated in rapidly proliferating tissues, and nuclear matrix (NM) is an important subnuclear locale of its functional signaling. In the prostate, nuclear CK2 is rapidly lost commensurate with induction of receptor-mediated apoptosis after growth stimulus withdrawal. By contrast, chemical-induced apoptosis in prostate cancer and other cells (by etoposide and diethylstilbestrol) evokes an enhancement in CK2 associated with the NM that appears to be because of translocation of CK2 from the cytoplasmic to the nuclear compartment. This shuttling of CK2 to the NM may reflect a protective response to chemical-mediated apoptosis. Supporting evidence for this was obtained by employing cells that were transiently transfected with various expression plasmids of CK2 (thereby expressing additional CK2) prior to treatment with etoposide or diethylstilbestrol. Cells transfected with the CK2␣ or CK2␣␤ showed significant resistance to chemical-mediated apoptosis commensurate with the corresponding elevation in CK2 in the NM. Transfection with CK2␤ did not demonstrate this effect. These results suggest, for the first time, that besides the commonly appreciated function of CK2 in cell growth, it may also have a role in protecting cells against apoptosis. Protein kinase CK2 (CK2)1 has been extensively studied in recent years for its potential role in multiple functional activities including the regulation of cell growth and proliferation. It is a ubiquitous protein Ser/Thr kinase, localized in the cell cytoplasm and nucleus, existing as a heterotetramer consisting of ␣, ␣Ј, and ␤ subunits (ϳ 42, 38, and 28 kDa, respectively) with the possible ␣ 2 ␤ 2 , ␣␣Ј␤ 2 , or ␣Ј␣Ј␤ 2 configuration. A number of putative substrates for CK2 have been identified in both the cytoplasm and the nucleus. Many of these are based on in vitro phosphorylation studies although a number of them have also been shown to be substrates for CK2 in vivo. Among the nuclear substrates are proteins involved in growth including RNA polymerases, topoisomerase II, protein B23, nucleolin, SV40 large T antigen, certain proto-oncogene products, and growth factors, as well as certain nonhistone proteins, which might include transcription factors, etc. (for examples see Refs. 1-10).In previous work, we have demonstrated that CK2 is dynamically regulated with respect to its nuclear localization, such that chromatin and NM appear to be its preferential sites of association within the nucleus. The association of CK2 in these compartments is profoundly responsive to the status of growth stimuli (1, 9, 11-13). To that end, we have employed androgen action in the prostate epithelial cells that is mediated via the androgen-receptor system as an experimental model. It is well known that withdrawal of androgenic growth signal via castration of adult rats induces rapid apoptosis in the epithelial cells of the gland and that this process is reversed on andro...

The chromosome 16p13.11 heterozygous deletion is associated with a diverse array of neuropsychiatric disorders including intellectual disabilities, autism, schizophrenia, epilepsy and attention-deficit hyperactivity disorder. However the clinical significance of its reciprocal duplication is not clearly defined yet. We evaluated 1645 consecutive pediatric patients with various developmental disorders by high-resolution microarray-based comparative genomic hybridization and identified four deletions and eight duplications within the 16p13.11 region, representing B0.73% (12/1645) of the patients analyzed. Recurrent clinical features in these patients include mental retardation/intellectual disability, autism, seizure, dysmorphic feature or multiple congenital anomalies. Our data expand the spectrum of the clinical findings in patients with these genomic abnormalities and provide further support for the pathogenic involvement of this duplication in patients who carry them.

We identified a novel homozygous 15q13.3 microdeletion in a young boy with a complex neurodevelopmental disorder characterized by severe visual impairment, hypotonia, profound intellectual disability, and refractory epilepsy. The homozygous deletion of the genes within this deleted region provides a useful insight into the pathogenesis of the observed clinical phenotype. Absence of the Transient Receptor Potential Cation Channel, Subfamily M, Member 1 (TRPM1) gene product is proposed as a possible mechanism for the severe visual impairment; absence of CHRNA7 (alpha7-nicotinic receptor subunit) as a cause of the refractory seizures and severe cognitive impairment; and deletion of MTMR10 and/or MTMR15 (encoding myotubularin related proteins) alone or combined with other homozygously deleted genes as a cause for the congenital hypotonia with areflexia. The distinctive clinical findings in this patient reveal potential functions of the genes within the deleted region.

. Renal epithelial cells constitutively produce a protein that blocks adhesion of crystals to their surface. Am J Physiol Renal Physiol 287: F373-F383, 2004. First published April 20, 2004 10.1152/ajprenal.00418.2003.-Attachment of newly formed crystals to renal tubular epithelial cells appears to be a critical step in the development of kidney stones. The present study was undertaken to identify autocrine factors released from renal epithelial cells into the culture medium that inhibit adhesion of calcium oxalate crystals to the cell surface. A 39-kDa glycoprotein that is constitutively secreted by renal cells was purified by gel filtration chromatography. Amino acid microsequencing revealed that it is novel and not structurally related to known inhibitors of calcium oxalate crystallization. Hence, it was named crystal adhesion inhibitor, or CAI. Immunoreactive CAI was detected in diverse rat tissues, including kidney, heart, pancreas, liver, and testis. Immunohistochemistry revealed that CAI is present in the renal cell cytosol and is also on the plasma membrane. Importantly, CAI is present in normal human urine, from which it can be purified using calcium oxalate monohydrate crystal affinity chromatography. CAI could be an important defense against crystal attachment to tubular cells and the subsequent development of renal stones in vivo.calcium oxalate monohydrate; cell-crystal interaction; DING protein; inhibitor; nephrolithiasis NEPHROLITHIASIS IS AN EXTREMELY common condition in the United States, affecting up to 10% of the population at some point during their lives (26,32). Although many affected individuals have identifiable urinary metabolic risk factors, such as excessively concentrated urine that may contain too much calcium, uric acid, or oxalate, or perhaps too little citrate, many do not (12). Therefore, the concentration of these urinary constituents does not appear to fully explain the formation of renal stones. In addition, nucleation and growth of individual crystals appear unlikely to produce particles large enough to occlude the nephron lumen in vivo (15). Recent evidence suggests, that in many calcium oxalate stone formers, the earliest changes may be depositions of calcium phosphate in the medullary interstitium, which then serve as a nidus for a calcium oxalate stone (14). The processes that mediate calcium phosphate deposition and its evolution into calcium oxalate stones remain to be determined. In more marked hyperoxaluric states (e.g., enteric or primary hyperoxaluria), direct adhesion of calcium oxalate crystals to renal epithelial cells may predominate (14). Therefore, our laboratory (19 -24) and others (29,30,37,38,43) have sought to identify regulatory mechanism(s) by which urinary calcium oxalate and calcium phosphate crystals in tubular fluid bind to renal epithelial cells, are retained in the kidney, and become a nidus for stone formation.Previous studies have demonstrated that anionic molecules in tubular fluid can coat calcium oxalate monohydrate (COM) and hydroxyapatite (H...

We report 4 interstitial inverted duplications with associated terminal deletions (inv dup del) involving the short arms of chromosomes 5 and 8, and the long arm of chromosome 13 by microarray-based comparative genomic hybridization (aCGH) combined with chromosome banding (GTG banding) and fluorescence in situ hybridization (FISH) analyses. Formation of the intermediate dicentric chromosomes in 3 of them occurred through breakage-fusion-bridge cycle mechanism (U-type exchange mechanism) and in the fourth one it occurred through the mediation of the inverted low-copy repeats on chromosome 8p23.1. Two of these 4 inv dup del were confirmed and a third one was suspected to be associated with telomere capture for the healing of the terminal deletions. These findings indicate that a telomere capture mechanism is frequently used for stabilizing the broken chromosome ends in this type of genomic rearrangements. In addition, the inv dup del(13) represents the first observation of inv dup del on chromosome 13 in humans, the inv dup del(5) represents the first observation of inv dup del(5p) with an associated telomere capture, and unique features of the remaining two inv dup del(8p) were also discussed.

Hemizygous deletions of the chromosome 22q11.2 region result in the 22q11.2 deletion syndrome also referred to as DiGeorge, Velocardiofacial or Shprintzen syndromes. The phenotype is variable but commonly includes conotruncal cardiac defects, palatal abnormalities, learning and behavioral problems, immune deficiency, and facial anomalies. Four distinct highly homologous blocks of low copy number repeat sequences (LCRs) flank the deletion region. Mispairing of LCRs during meiosis with unequal meiotic exchange is assumed to cause the recurrent and consistent deletions. The proximal LCR is reportedly located at 22q11.2 from 17.037 to 17.083 Mb while the distal LCR is located from 19.835 to 19.880 Mb. Although the chromosome breakpoints are thought to localize to the LCRs, the positions of the breakpoints have been investigated in only a few individuals. Therefore, we used high resolution oligonucleotide-based 244K microarray comparative genomic hybridization (aCGH) to resolve the breakpoints in a cohort of 20 subjects with known 22q11.2 deletions. We also investigated copy number variation (CNV) in the rest of the genome. The 22q11.2 breaks occurred on either side of the LCR in our subjects, although more commonly on the distal side of the reported proximal LCR. The proximal breakpoints in our subjects spanned the region from 17.036 to 17.398 Mb. This region includes the genes DGCR6 (DiGeorge syndrome critical region protein 6) and PRODH (proline dehydrogenase 1), along with three open reading frames that may encode proteins of unknown function. The distal breakpoints spanned the region from 19.788 to 20.122 Mb. This region includes the genes GGT2 (gamma-glutamyltransferase-like protein 2), HIC2 (hypermethylated in cancer 2), and multiple transcripts of unknown function. The genes in these two breakpoint regions are variably hemizygous depending on the location of the breakpoints. Our 20 subjects had 254 CNVs throughout the genome, 94 duplications and 160 deletions, ranging in size from 1 kb to 2.4 Mb. The presence or absence of genes at the breakpoints depending on the size of the deletion plus variation in the rest of the genome due to CNVs likely contribute to the variable phenotype associated with the 22q11.2 deletion or DiGeorge syndrome.

Many stimuli play a role in in¯uencing the structure and function of chromatin and nuclear matrix through post-translational modi®cations of the component proteins in these dynamic structures. We propose that the protein serine/threonine kinase CK2 (formerly casein kinase II) is one such agent that is involved in signal transduction in the nuclear matrix and chromatin in response to a variety of stimuli. Protein kinase CK2 appears to undergo rapid modulations in its association with nuclear matrix and nucleosomes in response to mitogenic signals and is involved in the phosphorylation of a variety of intrinsic proteins in these structures depending on the state of genomic activity. In addition, its association or loss from the nuclear matrix may also in¯uence the apoptotic activity in the cell. CK2 has been found to be dysregulated in virtually all the neoplasias examined and nuclear association appears to be an important facet of its expression in tumor cells. We hypothesize that CK2 provides a functional paradigm linking the nuclear matrix and chromatin structures. Identi®cation of precise loci of action of CK2 in these structures and how they in¯uence the morphological appearance of the nucleus under normal and abnormal growth conditions would be an important future direction of investigation.

We describe a 5 year old boy with a de novo t(l0;13) translocation and optic nerve coloboma-renal disease (ONCR). On the basis ofGTG banding analysis ofprometaphase chromosomes, the patient's karyo- Ophthalmological examination showed bilateral large optic discs with temporal colobomas and an anomalous vascular pattern.Urine analysis showed moderate proteinuria (1.0 g/day), but urinary sediments were unremarkable. The urinary levels of N-acetyl glucosaminidase (10.6 IU/1) and a-2-microglobulin (239 ng/ml) were raised. Blood chemistry showed mild renal dysfunction with blood urea-N of 38.5 mg/dl, creatinine of 1.3 mg/dl, and creatinine clearance of 56.5 ml/min. Serum levels of total protein, complement, and immunoglobulins were normal. There was no serological evidence of streptococcal infection. Ultrasonography showed normal sized kidneys (left: 6.5 x 3.0 cm, right: 6.0 x 2.0 cm), and voiding cystourethrography showed no 213