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The histone deacetylase (HDAC) inhibitor 4-phenylbutyrate (4-PB) is a non-toxic compound that can induce differentiation and promote maturation of various types of malignant cells. In the present study we show that 4-PB inhibit glioma cell proliferation, induce apoptosis and decrease mRNA expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in a concentration-dependent manner. Proliferation of established rat glioma cell lines (RG2 and C6) in culture was significantly decreased after treatment with 4-PB (2-40 mM). Low concentrations of 4-PB (2-20 mM) induced cell differentiation followed by apoptosis, whereas higher concentrations of 4-PB (40 mM) induced cell necrosis. Also, low concentrations of 4-PB significantly decreased GAPDH mRNA expression in C6 and RG2 rat glioma cells, suggesting a link between decreased cell proliferation, energy consumption, and down-regulation of GAPDH gene expression. We have found that GAPDH mRNA expression is markedly increased in human glioblastoma tissues. Therefore, the novel effect of 4-PB described here may offer means to suppress growth of glioma cells by diminishing the key reaction in glycolysis as a therapeutic approach for cancer.

Small cell lung cancer (SCLC) is a frequently occurring, highly aggressive tumor with a generally poor clinical outcome. In order to approach the genetic mechanisms behind the tumor progression, a general screen for DNA copy number alterations was performed using comparative genomic hybridization (CGH). In the series of 23 cases analyzed, CGH alterations were frequently detected ranging from 9 to 22 abnormalities in the individual tumors. The most frequent losses were detected on chromosome arms 3p (23/23), 13q14-21 (23/23), 4p (20/23), 4q (20/23), and 2q22-24 (18/23), while gains preferentially involved chromosome arms 19p (18/23), 19q (17/23), 1p31-35 (15/23), 17q22-25 (11/23), and 5p14-15.3 (9/23). In addition, high level amplification at chromosome arms 1p32-33 and 2p22-24 were found in three and two cases, respectively. Candidate genes for these amplifications include the l-MYC (1p32) and n-MYC (2p24.1) oncogenes, which have been previously found to be overexpressed in SCLC. Taken together, the findings demonstrate a high level of chromosomal instability in SCLC, which is well in agreement with the highly malignant phenotype of this tumor type. Subchromosomal regions involved in gains and losses were delineated and the amplifications of 1p32-33 and 2p22-24 were demonstrated, thus providing starting points for the exact characterization of molecular events involved in SCLC tumor progression.

Chromosome analysis by G-banding, spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) was performed on 24 short-term cultured transitional cell bladder carcinomas and 5 cell lines established from bladder carcinomas. Except for one tumor with an apparently normal chromosomal constitution, clonal chromosome abnormalities were detected in all examined cases by the combined approach. The application of SKY and FISH techniques improved the karyotypic descriptions, originally based on G-banding only, by identifying 32 additional numerical changes, by establishing the chromosomal origin of 27 markers and 2 ring chromosomes, by redefining 53 aberrations and by detecting 15 hidden chromosomal rearrangements. No recurrent translocation, however, was detected. The most prominent karyotypic feature was thus the occurrence of deletions and losses of whole chromosome copies indicating the importance of tumor suppressor genes in transitional cell carcinoma pathogenesis. Invasive carcinomas were karyotypically more complex than were low grade superficial tumors. Specific losses of material from chromosome 9 and from chromosome arms 11p and 8p, and gains of 8q and 1q seem to be early changes appearing in superficial tumors, whereas losses from 4p and 17p and the formation of an isochromosome for 5p were associated with more aggressive tumor phenotypes., (Copyright 2001 Wiley-Liss, Inc.)

Four cases of late onset clear cell renal cell carcinoma (RCC), a case of gastric cancer, and a case of exocrine pancreatic cancer were identified in a Japanese family. In order to elucidate the underlying mechanism for tumorigenesis in this family, extensive genetic studies were performed including routine and spectral karyotyping (SKY), fluorescence in situ hybridisation (FISH), comparative genomic hybridisation (CGH), loss of heterozygosity studies (LOH), and VHL mutation analysis. A germline translocation t(1;3)(q32-q41;q13-q21) was identified by karyotyping in five members of the family including all three RCC cases tested. The translocation was refined to t(1;3)(q32;q13.3) by FISH analysis using locus specific genomic clones, and the two breakpoints were mapped to a 5 cM region in 3q13.3 and a 3.6 cM region in 1q32. Both CGH and allelotyping using microsatellite markers showed loss of the derivative chromosome 3 carrying a 1q segment in the three familial RCCs analysed. Additional chromosomal imbalances were identified by CGH, including amplifications of chromosomes 5 and 7 and loss of 8p and 9. No germline VHL mutation was found but two different somatic mutations, a splice (IVS1-2A>C) and a frameshift (726delG), were identified in two RCCs from the same patient confirming their distinct origin. Taken together, these results firmly support a three step model for tumorigenesis in this family. A constitutional translocation t(1q;3q) increased the susceptibility to loss of the derivative chromosome 3 which is then followed by somatic mutations of the RCC related tumour suppressor gene VHL located in the remaining copy of chromosome 3.

Prostate cancer cell lines have been widely used as model systems characterizing pathogenetic, functional, and therapeutic aspects of prostate cancer development. However, their chromosomal compositions are poorly characterized. In this study, five prostate cancer cell lines-TSU-Pr1, JCA-1, NCI-H660, ALVA-31, and PPC-1-were investigated by G-banding, comparative genomic hybridization (CGH), and spectral karyotyping. The results were combined with our previous findings in the prostate cancer cell lines PC-3, DU145, and LNCaP. By comparative genomic hybridization (CGH), the most frequent losses were observed at 13q, 8p, 9p, and 4q, whereas gains were most commonly seen at 8q, 10q, and 18p. The composite karyotypes were characterized by multiple numerical and structural chromosomal aberrations. Recurrent breakpoints at 5q11, 8p11, and 10q22 were observed to participate in deletion and translocation events in five of the cell lines, suggesting the importance of tumor suppressor and/or oncogenes in these regions. ALVA-31 and PPC-1 shared nine identical derivative chromosomes, two of which have also been detected in PC-3. In addition, the identification of the same homozygous deletion at D10S541 and of an identical TP53 gene mutation in all three cell lines suggests a common origin of these cell lines., (Copyright 2000 Wiley-Liss, Inc.)

Human cancers arise by a combination of discrete mutations and chromosomal alterations. Loss of heterozygosity (LOH) of chromosomal regions bearing mutated tumor suppressor genes is a key event in the evolution of epithelial and mesenchymal tumors. Global patterns of LOH can be understood through allelotyping of tumors with polymorphic genetic markers. Simple sequence length polymorphisms (SSLPs, or microsatellites) are reliable genetic markers for studying LOH, but only a modest number of SSLPs are used in LOH studies because the genotyping procedure is rather tedious. Here, we report the use of a highly parallel approach to genotype large numbers of single-nucleotide polymorphisms (SNPs) for LOH, in which samples are genotyped for nearly 1,500 loci by performing 24 polymerase chain reactions (PCR), pooling the resulting amplification products and hybridizing the mixture to a high-density oligonucleotide array. We characterize the results of LOH analyses on human small-cell lung cancer (SCLC) and control DNA samples by hybridization. We show that the patterns of LOH are consistent with those obtained by analysis with both SSLPs and comparative genomic hybridization (CGH), whereas amplifications rarely are detected by the SNP array. The results validate the use of SNP array hybridization for tumor studies.

Alterations of 3p are the most frequently observed changes in follicular thyroid carcinomas. Loss of 3p25-pter has been speculated to be a critical event in the malignant transformation of a subset of thyroid follicular neoplasms. The present report describes a minimally invasive follicular thyroid carcinoma (FTC) with a balanced t(3;7)(p25;q34) and dic(15;22)(p11;p11) as the only abnormalities. The alterations were present in all metaphases analyzed and were demonstrated by G-banding, spectral karyotyping (SKY), and fluorescence in situ hybridization (FISH). This study represents the second case of FTC where 3p25 is involved in a balanced translocation. The findings support the existence of a gene locus in this region which is involved in the tumorigenesis of thyroid carcinoma.

Aims: Modern orthokeratology (ortho-k), using reverse geometry lens designs, is being widely used for myopia reduction world-wide but there has been no well-controlled clinical trial of this procedure. This study reports on the associated corneal changes and short-term safety of an orthokeratology procedure using the OK-74 lens design (known as OK704 in the UK)., Methods: We carried out a 100-day, controlled, randomised clinical trial in which 14 subjects underwent ortho-k and a further 14 were fitted with alignment fit contact lenses., Results: Central corneal flattening and peripheral corneal steepening occurred and myopia reduction was explained by the flattening of the central 2 mm of the cornea. The overall ocular health effects were similar in conventional and OK-74 lens wear., Conclusions: Corneal sphericalisation occurred. Daily wear of OK-74 lens and the conventionally-designed lens were equally safe over the 100-day period investigated. Further work is needed to evaluate the long term safety of ortho-k.

Orthokeratology has been used to provide temporary reduction of myopia since the 1950s and in recent years the development of new lens designs, materials and advanced instrumentation for corneal modelling has resulted in a resurgence in interest in this procedure. In particular, the reverse geometry design has allowed greater myopia reduction. Materials with high oxygen permeability have improved the corneal response to rigid lenses and in orthokeratology they allow overnight retainer lens wear. Corneal modelling systems allow the orthokeratology changes to be monitored and measured, and have increased our understanding of the technique. This paper summarises previous published work in this area and identifies the uncertainties which still remain.

Aims: Modern orthokeratology (ortho-k) using reverse geometry lens designs is being widely used for myopia reduction world-wide although there has been no well-controlled clinical trial of this procedure. This paper reports on the efficacy and predictability of an ortho-k procedure using the OK-74 lens design (now known as OK-704)., Methods: We carried out a 100-day, controlled, randomised clinical trial in which 14 subjects underwent ortho-k and a further 14 were fitted with aligned rigid contact lenses., Results: The mean reduction in myopia was 1.50 (SD 0.45) D in the ortho-k group and 0.01 (SD 0.20) D in the control group. Unaided vision improved by -0.64 (SD 0.22) logMAR units in the ortho-k group, compared with -0.09 (SD 0.11) units in the control group. Variables which correlated with refractive change were corneal thickness, p-value of the nasal semi-meridian and the difference between central and peripheral corneal powers. A multiple factors model can account for 72% of the refractive change., Conclusions: Ortho-k using the OK-74 lens design achieved an average myopia reduction of 1.50 D. The model developed can provide an estimate of the refractive change likely to occur in ortho-k, a matter of importance to both clinician and patient.

Human prostate cancer is characterized by multiple gross chromosome alterations involving several chromosome regions. However, the specific genes involved in the development of prostate tumors are still largely unknown. Here we have studied the chromosome composition of the three established prostate cancer cell lines, LNCaP, PC-3, and DU145, by spectral karyotyping (SKY). SKY analysis showed complex karyotypes for all three cell lines, with 87, 58/113, and 62 chromosomes, respectively. All cell lines were shown to carry structural alterations of chromosomes 1, 2, 4, 6, 10, 15, and 16; however, no recurrent breakpoints were detected. Compared to previously published findings on these cell lines using comparative genomic hybridization, SKY revealed several balanced translocations and pinpointed rearrangement breakpoints. The SKY analysis was validated by fluorescence in situ hybridization using chromosome-specific, as well as locus-specific, probes. Identification of chromosome alterations in these cell lines by SKY may prove to be helpful in attempts to clone the genes involved in prostate cancer tumorigenesis., (Copyright 2000 S. Karger AG, Basel)