[show abstract][hide abstract] ABSTRACT: Dehydroepiandrosterone (DHEA), the main brain neurosteroid, has been implicated in various psychiatric disorders especially those including gender differences. We studied genetic variability in the DHEA-producing enzyme CYP17A1 in relation to anorexia nervosa (AN) susceptibility and AN-related co-morbidities. We performed analysis of 100 Israeli AN family trios accounting for CYP17A1 haplotypes characteristic of populations of European origin and studied genotype-phenotype relationships using correlation analyses and transmission disequilibrium test. Although our analysis revealed no evidence of association between CYP17A1 and AN per se, it revealed an association between specific CYP17A1 haplotypes and AN co-morbidity, specifically anxiety. We found that a common CYP17A1 haplotype (H1) was associated with higher anxiety in AN patients (Clinical Global Impression; CGI-anxiety ≥4). Moreover, H1 homozygotes were at higher risk for expressing high CGI-anxiety levels (OR = 3.7), and H1 was preferentially transmitted to AN patients with high CGI-anxiety levels (P = 0. 037). We suggest that CYP17A1 H1 haplotype may contribute to genetic predisposition to higher CGI-anxiety levels in AN patients and that this predisposition may be mediated by reduced CYP17A1 enzymatic activity and corresponding lower DHEA production.
Archives of Women s Mental Health 06/2013; · 2.01 Impact Factor
[show abstract][hide abstract] ABSTRACT: The genetic factors participating in oral melanoma evolution have not been studied extensively. We aimed to analyze the prevalence of BRAF and GNAQ mutations in a series of oral melanocytic tumors, nevi, and melanomas.
The study group consisted of 4 melanomas and 10 nevi (6 intramucosal, 4 blue nevi). DNA was extracted from paraffin-embedded tissue sections, and mutations in GNAQ and BRAF were analyzed with the use of mass spectrometery.
V600E point mutation was identified in the BRAF gene in 3 intramucosal nevi and in 2 melanomas. Only 1 blue nevus harbored the GNAQ209 mutation. None of the BRAF-positive samples harbored GNAQ mutations.
The finding of BRAF mutations in oral benign and malignant melanocytic lesions points to a potential initiating role of BRAF in malignant transformation, which may have important therapeutic implications as those with BRAF mutations may benefit from specific treatment using RAF inhibitors.
[show abstract][hide abstract] ABSTRACT: Abstract The JAK2V617F mutation has emerged in recent years as a diagnostic as well as treatment target in patients with polycythemia vera (PV). We analyzed JAK2V617F allele burden (JAK2(V617F)) in a Jewish population with PV. Results were correlated with disease symptoms and complications. Median JAK2(V617F) was 48% and 54% in patients of Ashkenazi and non-Ashkenazi origin, respectively (p =0.75). Higher JAK2(V617F) was seen in patients with imaging-proven splenomegaly (p =0.01). A correlation between JAK2(V617F) and the weekly hydoxyurea dose needed for disease control was found (p =0.043). In addition, a trend for higher allele burden in patients with longer disease duration (p =0.064) and those treated with cytoreductive drugs other than hydroxyurea (p =0.056) was noted. Higher JAK2(V617F) was seen in patients with transformation to myelofibosis (p =0.0001), but not in patients with vascular complications. JAK2(V617F) may assist in prognostic stratification of patients with PV.
[show abstract][hide abstract] ABSTRACT: Purpose. RASSF1A inactivation in uveal melanoma (UM) is common and methylation-induced. We investigated the effect of RASSF1A re-expression on the UM phenotype in vivo and in vitro. Methods. The phenotypic effect of methylation-induced inactivation of RASSF1A in UM was explored using a stable RASSF1A-expressing UM-15 clone. RASSF1A expression was assessed using QRT-PCR. Proliferation was evaluated in vitro using MTT assays. Additionally, athymic NOD/SCID mice were injected subcutaneously or intraocularly with RASSF1A-expressing and -non-expressing UM-15 clones, and euthanized when tumors reached a volume of 1500 mm(3), or at 56 or 46 days, respectively. Tumor tissues, eyes, and livers were analyzed histologically. Results. In vitro analysis confirmed the lack of RASSF1A expression and full methylation of the RASSF1A promoter region in the UM-15 cell line, which was reversible following treatment with 5-Aza-2-deoxycytidine. Cells expressing exogenous RASSF1A showed slower proliferation than controls and regained sensitivity to cisplatin. Compared to mice injected with control cells, mice treated with UM-15 cells expressing exogenous RASSF1A did not acquire intraocular tumors, and their subcutaneous tumors were relatively delayed and small. Neither group had liver metastases. Conclusions. UM cells reduced tumorigenicity in the presence of activated RASSF1A. RASSF1A apparently has an important role in the development of UM, and its reactivation might be applied in the development of new treatments.
[show abstract][hide abstract] ABSTRACT: Mutations in the LMNA gene encoding lamins A/C are responsible for Hutchinson-Gilford syndrome (HGS), a disorder of premature aging. Cataract is 1 of the main manifestations. The most prevalent mutation in Hutchinson-Gilford syndrome is C1824T, which activates a cryptic splice donor site to produce an abnormal lamin A protein. The purpose of this study was to investigate a possible association of the C1824T mutation with age-related cataract. Anterior lens capsule material was collected during cataract extraction surgery from 178 patients with senile cataract during 2007-2008. DNA and mRNA were extracted and sequenced for the LMNA gene. DNA and cDNA were screened for the C1824T mutation, which was not detected. Messenger RNA (mRNA) expression was normal, with no truncation. We found that human age-related nuclear cataract is not associated with LMNA gene mutations or truncation of lamin A.
Neurobiology of aging 11/2011; 33(7):1487.e15-9. · 5.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: The phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma (AKT) viral oncogene pathway is involved in regulating the signaling of multiple biological processes such as apoptosis, metabolism, cell proliferation, and cell growth. Mutations in the genes associated with the PI3K/AKT pathway including PI3K, AKT, RAS and PTEN, are infrequently found within head and neck squamous cell carcinoma and more specifically are rarely reported in oral squamous cell carcinoma (OSCC) cases. We aimed to investigate the frequency of mutations in AKT1, PTEN, PIK3CA, and RAS (K-RAS, N-RAS, H-RAS) genes in 37 cases of oral squamous cell carcinoma (OSCC). Mutational analysis of PTEN, RAS, PIK3CA and AKT genes was performed using chip-based matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry and by direct sequencing. The only gene mutated in our series was the PIK3CA. Missense mutations of the PIK3CA gene were found in 4 of our cases (10.8%); no correlation has been found with oral location, stage and survival. The absence of mutations in AKT1, PTEN, and RAS genes in the present study is in accordance with previous studies confirming that these genes are rarely mutated in OSCC. Our data confirm that PIK3CA is important to OSCC tumorigenesis and can contribute to oncogene activation of the PIK3CA/AKT pathway in OSCC. The knowledge of the PIK3CA's involvement in OSCC is important because a specific kinase inhibitor could be considered as a future therapeutic option for OSCC patients with PIK3CA mutations.
[show abstract][hide abstract] ABSTRACT: Specific mutations leading to the development of various histological grades of intraductal papillary mucinous neoplasm (IPMN) have been partially characterized.
Analysis of 323 oncogenic mutations in 22 tumor-related genes was conducted, using a chip-based matrix-assisted laser desorption time-of-flight mass spectrometer of DNA extracted from microdissected cells of low-grade (n = 14), borderline (n = 6), and invasive IPMN (n = 7). Additional assays were performed on the DNA extracted from dyplastic cells found in the background of the adenocarcinoma.
We identified 9 K-ras mutations (low grade, 2/14; borderline, 1/6; invasive, 6/7), 3 p53 mutations (low grade, 1/14; invasive 2/7), and 2 PIK3CA mutations (low grade, 1/14; invasive, 1/7). K-ras, p53, and PIK3CA mutations present in the invasive cancer were absent in the adjacent precursor cells in 50% of the cases. In one patient, K-ras mutation was present in the precursor lesion and absent in the adjacent invasive lesion.
Of the 22 screened tumor-related genes, only K-ras, p53, and PIK3CA mutations were found in IPMN. K-ras mutations are more prevalent in invasive than premalignant IPMN. The variable coexistence of mutations in the invasive cancer and in the adjacent precursor cells may point to the heterogeneous nature of this tumor.
Journal of Gastrointestinal Surgery 01/2011; 15(3):503-11. · 2.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: Somatic mutations in codon 209 of the GNAQ gene are the first initiating events to be identified in uveal melanoma. The purpose of this study was to search for GNAQ209 mutations in conjunctival melanocytic lesions.
Forty archival samples of conjunctival melanocytic lesions (conjunctival nevi, primary acquired melanosis, and conjunctival melanoma), 27 samples of uveal melanoma, and 11 samples of uveal melanoma metastases to the liver (3 of which matched primary uveal melanoma samples)-a total of 78 samples from 75 patients- were examined for the presence of GNAQ209 mutations by using chip-based, matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry. Direct sequencing was also performed.
The GNAQ209 mutation was identified in 12 (44.5%) uveal melanoma samples and 4 (36.5%) of the 11 metastases of uveal melanoma. It was not detected in any of the other melanocytic lesions.
The GNAQ209 mutation rate in uveal melanoma in this study is in line with the rate in other reports. The finding of the same genotype in the primary tumors and their metastases suggests that mutation in GNAQ is an early event in uveal melanoma tumorigenesis. The lack of GNAQ mutations in conjunctival melanocytic lesions suggests the involvement of a different tumorigenic pathway from that of uveal melanoma.
[show abstract][hide abstract] ABSTRACT: DNase II like acid DNase (DNase IIβ, DLAD) is expressed in human and murine cells in the lens. Studies in mice have reported that abnormal degeneration of cellular organelles by DLAD reduced lens transparency and that the DLAD gene may be involved in cataract formation. The aim of the present study was to search for possible genetic alterations in the DLAD gene in human senile cataract. Anterior lens capsule material was collected during surgery from 55 patients with senile cataract, with or without a subcapsular component. Total DNA was extracted, amplified by polymerase chain reaction and sequenced for exon 3 (n = 51) exon 4 (n = 40) and all 6 exons of the DLAD gene (n = 27). No mutation was found. There were genomic polymorphisms in all exons except 3 and 4. Nonsynonymous genomic polymorphisms were detected in exon 1 (rs738573) and exon 2 (rs3754274) and synonymous polymorphisms were detected in exon 5 (rs7511984) and exon 6 (rs3768250). In contrast to findings in mice, based on the limited samples analyzed, this study suggests that human age-related nuclear cataract is not associated with DLAD mutations.
International Journal of Genetics and Molecular Biology 07/2010; 2:121-125.
[show abstract][hide abstract] ABSTRACT: To investigate whether acquired somatic mutations in the iron response element of the ferritin L-chain gene account for the age-related cataract.
The 15 most prevalent point mutations causing hereditary hyperferritinemia cataract syndrome (HHCS) were screened in patients with age-related cataract using MALDI-TOF Mass Spectrometry. DNA samples were obtained from the lens capsules of patients following cataract surgery, and subjected to PCR amplification. Products were analyzed by a Sequenom® mass spectrometer, and classified as a mutation or wild type according to molecular weight. For a positive control, L-ferritin G32T mutation detected by direct sequencing in 3 members of an Israeli family known to be affected by HHCS was used.
DNA samples were isolated from the lens capsules of 90 patients, mean age 73.86, and screened for L-ferritin mutations. While the G32T mutation was detected in all 3 positive control cases, all other patients were negative for the 15 mutations.
Somatic mutations in the iron response elements (IRE) of the L-ferritin gene are infrequent in the age-related cataract. The role of L-ferritin genetic variations in the pathogenesis of age-related cataract is yet to be explored.
[show abstract][hide abstract] ABSTRACT: The PI3K/AKT pathway is frequently activated in endometrial carcinoma (EC) mainly due to mutations in the PIK3CA and PTEN genes. These events are common and believed to be the key to endometrial carcinogenesis. Recently, a somatic activating mutation in the AKT1 gene (E17K) was identified in several cancer types. In this study we explored the frequency of this AKT1 mutation in endometrial carcinoma.
Tumor DNA, extracted from 73 EC was analyzed for AKT1 E17K mutation (G49A) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition, the tumors were screened for coexisting common mutations in PTEN, PIK3CA and KRAS.
The AKT1 E17K mutation was detected in 4% of EC. One of the AKT1-mutated tumors showed coexisting PTEN loss-of-function mutation.
We identified the AKT1 E17K mutation in 4% of endometrial carcinomas. The presence of double AKT1/ PTEN mutants is in accord with the hypothesis that in EC more than one hit is required to completely activate the PI3K pathway. Furthermore, AKT1 mutations were limited to high grade, advanced stage tumors suggesting that this mutation confers a more aggressive tumor behavior.
[show abstract][hide abstract] ABSTRACT: To investigate the neuroprotective effect of brimonidine following induction of ischaemic optic neuropathy in rodents (rAION).
Mice were treated with an intraperitoneal injection of brimonidine 48, 24 or 0 h before rAION induction or eye drops for 5 days after rAION induction. Retinal ganglion cell (RGC) loss and expression of genes involved in the angiogenesis (vascular endothelial growth factor [VEGF], pigment epithelium-derived factor [PEDF], The epidermal growth factor homology domains-2 [Tie-2]), ischaemia (haem oxygense-1 [HO-1], hypoxia-inducible factor 1alpha[HIF-1alpha], endothelial nitric oxide synthase [eNOS]) and oxidative stress (superoxide dismutase-1 [SOD-1], glutathione peroxidase-1 [GPX-1]) response to ischaemic damage were compared with sham or rAION-untreated mice.
No RGC loss was detected in the brimonidine-treated mice. Effect of post-rAION eye drops: day 1--no decrease in retinal mRNA levels of angiogenesis-related genes, increase in ischaemia- and oxidative stress-related genes except HIF-1alpha; day 3--baseline or higher levels of oxidative and ischaemia-related genes except HIF-1alpha, increase in VEGF, decrease in PEDF; day 21--no change in angiogenesis-related genes. Effect of pre-rAION injection: baseline levels of angiogenesis-related genes with all injection schedules; increase in ischaemia-related genes with 48-h and 0-h pretreatment; decrease in HO-1 and eNOS with 24-h pretreatment; increase in oxidative-related genes except GPX-1. In optic nerve tissue, HO-1, HIF-1alpha and SOD-1 decreased on day 1 after topical administration and were still below baseline on day 3.
The increase in HO-1 associated with rAION is mitigated with brimonidine treatment, especially when administered intraperitoneally. Topical brimonidine apparently reduces VEGF, Tie-2, HIF-1alpha and GPX-1 expression on day 21. These results agree with published data and may have therapeutic implications for patients diagnosed with AION in the acute phase.
Clinical and Experimental Ophthalmology 09/2009; 37(7):718-29. · 1.96 Impact Factor
[show abstract][hide abstract] ABSTRACT: The PI3K/AKT pathway is frequently activated in human cancer. Recently, a G to A point mutation (E17K) was found in the pleckstrin homology domain of AKT1. We aimed to explore this mutation in cases of urothelial carcinoma. Using chip-based matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometer, AKT1 E17K mutation was searched in 26 total RNA samples obtained from 26 patients known to have urothelial carcinoma. Mutation was found in one out of 26 (3.8%) patients - a 46 year old female with a low grade transitional cell carcinoma located to the lamina propria (Ta disease). Our finding is in line with previous studies showing AKT1 E17K mutation to be rare. Yet, further studies are required to determine whether this mutation is indeed related to less aggressive disease and carries better prognosis.
Cancer genetics and cytogenetics 06/2009; 191(1):34-7. · 1.54 Impact Factor
[show abstract][hide abstract] ABSTRACT: Many malignancies are known to be associated with abnormal activation of the PI3K-AKT pathway. Recently, a somatic mutation in the AKT1 gene (E17K) was identified in a small proportion of human tumors. This mutation activated AKT1 by means of abnormal membrane recruitment and stimulated downstream signaling. This study was designed to analyze AKT1 mutations in retinoblastoma and gain insights into the role PI3K-AKT pathway plays in the development of this tumor.
Twenty-four samples of retinoblastoma from children were analyzed for mutations in the AKT1, PTEN and K-RAS genes, using a chip-based matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometer. Mutations in the PIK3CA gene were analyzed in 16 retinoblastoma samples using direct sequencing.
These results show that the mutation E17K/AKT1 was not detected in the 24 samples of retinoblastoma analyzed. K-RAS mutations were identified in two samples. There were no mutations in any of the other genes analyzed by a mass array system. On direct sequencing of 16 samples for the PIK3CA gene, one sample showed gain of function mutation in exon 9. In another sample, a genetic polymorphism of unknown significance (rs17849079) was detected in exon 20.
Although the PI3K-AKT pathway is known to be dysregulated in retinoblastoma, the low frequency of oncogenic mutations in the AKT1, PIK3CA, and PTEN genes, suggests a different activating mechanism.
[show abstract][hide abstract] ABSTRACT: Neural stem cells are currently being investigated as potential therapies for neurodegenerative diseases, stroke, and trauma. However, concerns have been raised over the safety of this experimental therapeutic approach, including, for example, whether there is the potential for tumors to develop from transplanted stem cells.
A boy with ataxia telangiectasia (AT) was treated with intracerebellar and intrathecal injection of human fetal neural stem cells. Four years after the first treatment he was diagnosed with a multifocal brain tumor. The biopsied tumor was diagnosed as a glioneuronal neoplasm. We compared the tumor cells and the patient's peripheral blood cells by fluorescent in situ hybridization using X and Y chromosome probes, by PCR for the amelogenin gene X- and Y-specific alleles, by MassArray for the ATM patient specific mutation and for several SNPs, by PCR for polymorphic microsatellites, and by human leukocyte antigen (HLA) typing. Molecular and cytogenetic studies showed that the tumor was of nonhost origin suggesting it was derived from the transplanted neural stem cells. Microsatellite and HLA analysis demonstrated that the tumor is derived from at least two donors.
This is the first report of a human brain tumor complicating neural stem cell therapy. The findings here suggest that neuronal stem/progenitor cells may be involved in gliomagenesis and provide the first example of a donor-derived brain tumor. Further work is urgently needed to assess the safety of these therapies.
PLoS Medicine 03/2009; 6(2):e1000029. · 15.25 Impact Factor
[show abstract][hide abstract] ABSTRACT: The transcription factor forkhead box P3 (FOXP3 in humans; Foxp3 in mice) controls the development and function of regulatory T cells (Treg). In mice, CD4(+)CD25(-) T cells do not express Foxp3 following TCR activation. Whether FOXP3 is a common activation-induced molecule in human T cells--hence not Treg restricted--is currently a controversial issue. As FOXP3 can significantly modulate the function of T cells, understanding the mode (and regulation) of FOXP3 expression in human T cells is vital. Here we show that in conventional CD4(+)CD25(-) T cells, the induction of FOXP3 expression following TCR activation is both restricted to a fraction of the progeny and transient. Moreover, FOXP3 expression in vivo is particularly infrequent in activated effector CD4(+) T cells that accumulate within inflamed joints. We next demonstrate that the repression of FOXP3 transcription in resting conventional human CD25(-) T cells is linked to complete methylation of an evolutionarily conserved intronic CpG island. The dense methylation pattern is furthermore inherited after activation by progeny. This intronic CpG island, on the other hand, is frequently unmethylated in CD4(+)CD25(+) T cells. Importantly, blocking maintenance DNA methylation, by pharmacological inhibition of DNA methyltransferase-1, induced significant and stable activation-dependent FOXP3 expression in cycling conventional T cells, which was further amplified by co-treatment with transforming growth factor beta. In contrast to natural Treg, such induced CD4(+)FOXP3(+) T cells could produce pro-inflammatory cytokines upon activation. These results indicate that DNA methylation normally restricts FOXP3 transcription in conventional human T cells.
International Immunology 08/2008; 20(8):1041-55. · 3.14 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate levels of proinflammatory cytokines in a mouse model of anterior ischemic optic neuropathy (rAION).
AION was induced in C57/BL6 mice and levels of IL-6, TNF-alpha, and MIP-2 were measured in plasma by ELISA and in the optic nerves by RT-PCR at predetermined intervals.
Plasma: IL-6 levels were elevated immediately after rAION induction and decreased gradually thereafter. TNF-alpha showed an early peak on day 1 and again from day 21. MIP-2 levels were increased until day 7. Optic nerve: IL-6, TNF-alpha, and MIP-2 levels increased within a few hours and then decreased gradually. IL-6 had a second peak on day 3.
Proinflammatory cytokines may play a role in the pathogenesis of rAION.
Current eye research 05/2008; 33(4):395-401. · 1.51 Impact Factor