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Biomedical subjects

M Lishner

Publications and source records attributed to M Lishner.

At least 19 recordsLinked to original sources
PubMed2006

Impaired migration of trophoblast cells caused by simvastatin is associated with decreased membrane IGF-I receptor, MMP2 activity and HSP27 expression.

BACKGROUND: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme-A reductase, the rate-limiting enzyme of the mevalonate pathway, and are used successfully in the treatment of hypercholesterolaemia. Statins are contraindicated during pregnancy. Lately, we have shown that simvastatin has adverse affects on human first trimester placental explants' proliferation and migration. The objective of the present study was to investigate the molecules involved in mediating simvastatin's effect on trophoblast cell migration. We hypothesized that simvastatin attenuates insuline-like growth factor-I (IGF-I) receptor expression (involved in trophoblast motility), matrix metalloproteinase (MMP) activities, and heat shock protein 27 (HSP27) levels (whose mRNA is actively transcribed during trophoblast differentiation) in trophoblast cells thus consequently effecting their migration. METHODS: Human placental explants were cultured above a matrigel with/without simvastatin (10 microM) for 5 days. In this model, trophoblast migrates from the villi into the matrigel. Western-blot and immunohistochemistry served for analysing HSP27 expression. Immunohistochemistry was used for assessing IGF-I receptor localization. MMPs activity was assayed by gel zymography. RESULTS: Simvastatin reduced IGF-I receptor membranal expression, MMP2 activity and HSP27 expression in trophoblast cells (P < 0.05). CONCLUSIONS: The inhibitory effect of simvastatin on trophoblast cell migration is associated with a significant decrease in the tested molecules, which probably contributes to the impaired migration.

Blotting, Western↗
PubMed2006

Random aneuploidy in CML patients at diagnosis and under imatinib treatment.

Chronic myeloid leukemia (CML) is characterized by the presence of a BCR-ABL fusion gene, which is the result of a reciprocal translocation between chromosomes 9 and 22, and is cytogenetically visible as a shortened chromosome 22 (Philadelphia). Research during the past two decades has established that BCR-ABL is probably the pathogenetic pathway leading to CML, and that constitutive tyrosine kinase activity is central to BCR-ABL capacity to transform hematopoietic cells in vitro and in vivo. The tyrosine kinase inhibitor imatinib mesylate was introduced into the treatment regimen for CML in 1998. During the last few years, reports on chromosomal changes during imatinib treatment have been described. In this study, we evaluated the random aneuploidy rate with chromosomes 9 and 18 in bone marrow from treated and untreated patients. We found higher aneuploidy rates in both treated and untreated patients compared to the control group. In three patients who were treated with imatinib mesylate for more than 1.5 years, triploidy also appeared in some nuclei. To our knowledge, this is the first report on new chromosomal changes such as random aneuploidy and triploidy under imatinib treatment, but more studies are needed to investigate the long-term effect of the imatinib treatment on genetic instability.

Adult↗
PubMed2006

The influence of different chromosomal aberrations on molecular cytogenetic parameters in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia of adults in Western countries. The most frequent recurring chromosomal aberrations identified in B-CLL patients are trisomy 12 and deletions of 13q, 17p, and 11q. Cases with deletions of 11q and 17p have a poor prognosis, whereas cases with deletions in 13q have a favorable prognosis. It was previously shown that CLL patients with trisomy 12 and del(13)(q14) have a higher rate of asynchronous replication of normal structural genes when compared to those with normal karyotypes. We studied the replication pattern of the structural locus 21q22 and the imprinted gene SNRPN and its telomere (15qter) and the random aneuploidy of chromosomes 9 and 18 in CLL patients with trisomy 12 and deletions of 11q and 17p, and compared the results to those of CLL patients without these aberrations and to healthy controls. Random aneuploidy rate was higher in the group of patients with trisomy 12 as compared to all other groups. The replication pattern with higher asynchronous pattern was found in both aberration groups compared to the CLL patients without the aberrations and to the control group with involvement of 21q22 and 15qter, whereas the highest synchronous group was found in the 2 aberrations CLL patient groups compared to the other groups with the imprinted locus SNRPN. The existence and significance of chromosomal aberrations in CLL have a deleterious effect on the processes of cell cycle and gene replication and may have biological and prognostic implications.

Adult↗
PubMed2005

Random aneuploidy in neoplastic and pre-neoplastic diseases, multiple myeloma, and monoclonal gammopathy.

In this study we evaluated the aneuploidy rate of cells from patients considered to have a premalignant condition (monoclonal gammopathy or MGUS) and patients with multiple myeloma, as well as healthy controls. By applying a fluorescence situ hybridization technique, we estimated the random aneuploidy rate of alpha-satellite (centromeres) probes from chromosomes 9 and 18. The monosomy and total aneuploidy rates were higher in the two study groups compared to the control group. The monosomy rate was significantly higher in the MGUS group compared to the group with chromosome 18 alpha-satellite probes, a finding that was reported before in preneoplastic conditions. Our results support the cancer aneuploidy theory that carcinogenesis is initiated by a random aneuploidy, which is induced either spontaneously or by a carcinogen. The resulting karyotype instability sets a chain reaction of aneuploidization, which generates even more abnormal and eventually cancer-specific combinations and rearrangements of chromosomes.

Aged↗
PubMed2005

Simvastatin has deleterious effects on human first trimester placental explants.

BACKGROUND: Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMG-CoA reductase), the rate-limiting enzyme of the mevalonate pathway, and have been used successfully in the treatment of hypercholesterolaemia. Animal models have provided evidence for the teratogenic effects of statins on pregnancy outcome. Thus statins are contraindicated during pregnancy. However, conflicting data are available from inadvertent use of statins in human pregnancy. Therefore we decided to explore the effects of simvastatin on the placenta in an in vitro human placental model. METHODS: Human first trimester placental explants that were grown on matrigel were exposed to medium supplemented with simvastatin. Migration of extravillous trophoblast cells was assessed by visual observation. Proliferative and apoptotic events of the trophoblast cells were assesed by immunohistochemical examination using anti-Ki67 and anti-activated caspase-3 antibodies respectively. Hormone levels were measured. RESULTS: Simvastatin sharply inhibited migration of extravillous trophoblast cells from the villi to the matrigel (P < 0.05). Moreover, simvastatin inhibited half of the proliferative events in the villi (P < 0.05) and increased apoptosis of cytotrophoblast cells compared to control. Moreover, simvastatin significantly decreased secretion of progesterone from the placental explants (P < 0.01). CONCLUSION: Simvastatin adversely affects human first trimester trophoblast.

Apoptosis↗
PubMed2005

Microsatellite instability in patients with chronic B-cell lymphocytic leukaemia.

The purpose of our study was to evaluate the microsatellite instability (MSI) at selected loci with known involvement in the oncogenesis of chronic B-cell lymphocytic leukaemia (B-CLL). DNA from B cells (tumour cells) and from T cells (normal controls) of 27 samples of 26 patients with previously untreated B-CLL was extracted. Microsatellite instability in six microsatellite markers was tested using GeneScan Analysis Software. The rate of replication errors positive phenotype (RER+) was determined (MSI in more than 30% of examined loci). RER+ was found in four out of 27 patients (14.8%). A larger proportion of patients with stage C B-CLL exhibited RER+ than those with stage A or B (P < 0.05). A higher prevalence of RER+ was demonstrated in a subgroup of patients with additional malignancies (three out of eight patients) in comparison with patients with B-CLL alone (1/19) (P = 0.031). In conclusion, our study demonstrated that MSI might have a more prominent role in pathogenesis of B-CLL than reported to date. This may result from a selection of microsatellite markers adjacent to chromosomal loci, which are involved in B-cell malignancies, and using GeneScan Analysis Software, which is most modern and precise method of microsatellite analysis.

Aged↗
PubMed2005

The effect of 6-mercaptopurine on early human placental explants.

BACKGROUND: 6-mercaptopurine (6-MP) is an antineoplastic and immunosuppressive drug. Recently, more women have received this drug during pregnancy. Animal studies have shown that 6-MP has deleterious effects on the fetus, while human data include prematurity, intrauterine growth restriction, low birth weight and malformations that occur especially when the drug is administered in the first trimester of pregnancy. OBJECTIVES: To study the effects of 6-MP on cellular functions of human trophoblast explants. METHODS: Human placental explants (5.5-9 weeks gestational age), that were grown on matrigel, were exposed to medium containing 6-MP for 5 days. Medium alone served as control. Extravillous trophoblast (EVT) cell migration assessment was performed by visual observation. Analysis of proliferating events of the trophoblast cells was assessed by immunohistochemical examination. Apoptosis was analyzed by Tunnel procedure and by anti-caspase 3 staining and hormone level by enzyme-linked immunosorbent assay. RESULTS: 6-MP inhibited migration of EVT cells from the villi to the matrigel with a lower proliferation rate and increased apoptosis of cytotrophoblast cells compared to controls. However, no significant effect of 6-MP on hormone levels was observed. CONCLUSIONS: 6-MP inhibited migration and proliferation of trophoblast cells in first-trimester human placental explant culture.

Antimetabolites, Antineoplastic↗
PubMed2005

Random aneuploidy and telomere capture in chronic lymphocytic leukemia and chronic myeloid leukemia patients.

Telomeric regions of the human genome are of particular interest, because rearrangements of these regions are difficult to identify by conventional chromosome banding technology. With the advent of molecular cytogenetic techniques such as fluorescence in situ hybridization (FISH), it has been possible to investigate the terminus in cytogenetically visible terminal deletions and telomere rearrangements. We investigated telomere capture and aneuploidy rates in chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) patients, as well as in healthy control subsets. Using a FISH technique, we estimated the random aneuploidy and telomere capture of the 21q22, SNRPN, and 15qter loci. Higher aneuploidy rates were found in the leukocytes of CLL and CML patients, compared with the control group, for the 21q22 and SNRPN loci. There was no difference in the aneuploidy rate between the CML and CLL groups. Telomere capture was found in the two groups (CLL and CML), but not in the control group. We propose that the telomere capture phenomenon is much more common than has been reported in the literature; however, its prognostic significance is yet to be established.

Aged↗
PubMed2005

Non-steroidal anti-inflammatory drugs for the prevention and treatment of cancer.

Non-steroidal anti-inflammatory drugs (NSAIDs), both cyclooxygenase-2 (COX-2) selective and nonselective inhibitors, are amongst the most popular medications worldwide. Whilst their anti-inflammatory effect is well known, recent studies have demonstrated an unexpected effect in both the prevention and treatment of several types of cancer. The anticancerous effect of NSAIDs is believed to be mainly due to the inhibition of COX-2, which is overexpressed in many types of cancer and may play a major role in tumourigenesis. In this review, we will describe the possible mechanisms for NSAIDs anticancer effect and summarize the major clinical studies in cancer prevention and treatment. We will also discuss the effect of the recent reports of adverse cardiovascular effects on anticancer research of the selective COX-2 inhibitors.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Deletion of 5q31 and 7q31 in patients with stable melphalan treated multiple myeloma.

Multiple myeloma represents a malignant proliferation of plasma cells derived from a single clone. It is well known that alkylating agents are capable of inducing myelodysplastic syndromes (MDS) and acute myelocytic leukemias (AML). This risk of both diseases in patients with multiple myeloma has been estimated to be 10-20% after 10 years. We aimed to evaluate the time course and the type of genetic abnormalities in melphalan-treated patients in the chronic stage of the disease. We applied fluorescence in situ hybridization methods with probes to 5q31 and 7q31 to mononuclear peripheral blood leukocytes of 18 melphalan-treated patients and compared the results to those of 8 untreated myeloma patients. We found three patients (17%) with a 5q31 deletion in their peripheral white blood cells, but no 7q31 deletion. These findings suggest that 5q- occurs before the overt development of MDS/AML and raise important concerns regarding long-term treatment of myeloma patients with alkylating agents. Also, the performance of cytogenetic evaluation should be considered before autologous transplantation. The clinical and biological implications of these findings should be evaluated in larger clinical and laboratory studies.

Aged↗
PubMed2004

Fluorouracil induces apoptosis and surface molecule modulation of peripheral blood leukocytes.

Little is known about the direct effect of chemotherapy on normal peripheral blood leukocytes (PBL) or its contribution to leukopenia. We examined 5'-fluorouracil's (5FU) effect on PBL apoptosis and adhesion molecules' expression in a single-drug solid-tumor model. Possible apoptosis mediators were examined. The study included 32 colorectal cancer patients; apoptosis was determined by annexin-V binding and light-scatter morphology before and after drug infusion. CD18, CD11a, CD11b, and CD63 membranal levels were assayed by flow cytometry. Apoptosis was increased post-5FU administration in neutrophils (PMN), monocytes and lymphocytes (P < 0.05). Levels of Fas receptor and activated caspase 3 did not vary indicating that the process was not mediated by caspase 3 in the timeframe studied. Reduced CD63 on monocytes and decreased CD18 expression on PMN and non-apoptotic monocytes were observed (P < or = 0.05). CD11a,b expression did not vary. Decreased CD18 and CD63 levels were demonstrated in apoptotic and non-apoptotic PBL implying a more direct association with the drug itself.

Antigens, CD↗
PubMed2004

Expression of tetraspanins in peripheral blood leukocytes: a comparison between normal and infectious conditions.

The role of tetraspanins is undefined, despite their detection in diverse cell types and functions. This study addresses the characterization of tetraspanin expression levels in normal peripheral blood leukocytes (PBL) and in patients with bacterial infection. Membranal and cytoplasmic expression of CD9, CD53, CD63, CD81, CD82 and CD151 in polymorphonuclears (PMN), monocytes, B and T lymphocytes was assessed using flow cytometry. Results suggested that for normal PBL, PMN are distinguished by dominant cytoplasmic CD63; monocytes and B cells prevailingly express CD53; CD82 is primarily expressed on T-cell membranes. However, a major trend of downregulation was demonstrated for the examined tetraspanins, except CD63, in all patients' PBL subtypes. Therefore, tetraspanin modulation in infections may be attributed to elevated leukocyte motility in immune reactions and this is compatible with the previous publications of tetraspanins as metastasis suppressors. This work represents the first comprehensive baseline of tetraspanin expression in normal PBL and in infectious disorders.

Adolescent↗
PubMed2003

The effect of chlorambucil treatment on cytogenetic parameters in chronic lymphocytic leukemia patients.

The most common treatment of chronic lymphocytic leukemia (CLL) is the alkylating agent chlorambucil (CLB), with or without prednisone. In the present study, our aim was to evaluate whether treatment with CLB for more than one year induced genetic changes manifested by comparative genomic hybridization (CGH) as new chromosomal aberrations. We also studied whether CLB affected the pattern of replication by using fluorescence in situ hybridization (FISH). We found a similar rate of asynchronous pattern of replication in both treated and untreated patients with CLL. Most of the aberrations found with CGH were previously reported in CLL. More prognostically unfavorable aberrations and more cases with genetic changes were found in the treated group. The changes found were not typical of the secondary genetic aberrations associated with alkylating agents. Thus, we conclude that treatment of CLL with CLB for at least a year does not affect the parameters analyzed in this study. Longer studies are needed to further explore the effects of alkylating agents on normal and malignant cells.

Aged↗
PubMed2001

Neurodevelopment of children exposed in utero to treatment of maternal malignancy.

Cancer is the second most common cause of death during the reproductive years, complicating approximately 1/1000 pregnancies. The occurrence of cancer during gestation is likely to increase as a result of a woman's tendency to delay childbearing. Improved diagnostic techniques for malignancies increases detection of cancer during pregnancy. Malignant conditions during gestation are believed to be associated with an increase in poor perinatal and fetal outcomes that are often due to maternal treatment. Physicians should weigh the benefits of treatment against the risks of fetal exposure. To date, most reports have focused on morphologic observations made very close to the time of delivery with little data collected on children's long-term neurodevelopment following in utero exposure to malignancy and treatment. Because the brain differentiates throughout pregnancy and in early postnatal life, damage may occur even after first trimester exposure. The possible delayed effects of treatment on a child's neurological, intellectual and behavioural functioning have never been systematically evaluated. The goal of this report was to summarize all related issues into one review to facilitate both practitioners' and patients' access to known data on fetal risks and safety.

Child↗
PubMed2001

Comparative genomic hybridization in polycythemia vera and essential thrombocytosis patients.

Polycythemia vera (PV) and essential thrombocytosis (ET) are clonal chronic myeloproliferative disorders originating from a multipotent stem cell. Bone marrow examinations reveal chromosomal abnormalities in 15-43% of PV patients and 5% of ET patients, but no specific recurring abnormality has been found to date. We aimed to find cytogenetic aberrations in PV and ET by comparative genomic hybridization (CGH), a relatively new molecular cytogenetic technique. In this study, CGH analysis was performed on peripheral blood leukocytes of 12 PV patients and 8 ET patients. One patient (8.3%) with PV had an abnormal karyotype with a deletion in 7q11.2 and one patient with ET (12.5%) had a gain in 18p. Peripheral blood analysis by CGH revealed a low frequency of cytogenetic abnormalities in PV and ET patients. However, using CGH we were able to detect two cytogenetic aberrations that were not reported previously in these disorders.

Aged↗
PubMed2001

Modified order of allelic replication in lymphoma patients at different disease stages.

Asynchronous replication of homologous loci was reported in lymphocytes of patients with lymphoma, ovarian and renal cancer as well as in lymphocytes of patients with premalignant conditions, for example, essential mixed cryoglobulinemia associated with hepatitis C virus and in monoclonal gammopathy of unknown significance. In the present study we evaluated the replication pattern in lymphocytes of four groups of patients with intermediate grade of non-Hodgkin lymphoma at various stages of their disease: 1) at diagnosis; 2) during cytotoxic treatment; 3) in remission; and 4) in relapse. A significantly higher proportion of the asynchronous pattern of replication at diagnosis, during cytotoxic treatment, and in relapse was noted as compared to healthy controls and to patients who achieved remission of their lymphoma. Also, the frequency of the two doublets (DD) pattern in every group studied was significantly lower than in the controls. If our findings can be confirmed in larger, long-term prospective studies, it may allow the use of a simple and inexpensive tool to closely observe patients with lymphoma who are at high risk for relapse.

Aged↗
PubMed2001

Analysis of chromosomal aberrations in large hepatocellular carcinomas by comparative genomic hybridization.

Hepatocellular carcinoma (HCC) is a very common and highly malignant tumor, associated mainly with chronic viral hepatitis, cirrhosis of any cause, aflatoxin exposure and ethanol consumption. The aim of this study was to map genomic aberrations in HCC by a recently developed technique: comparative genomic hybridization (CGH). We applied CGH on 17 liver specimens, of which seven were HCCs. The rest were benign liver tumors, cirrhotic and normal livers, and other liver malignancies. Our study included mainly large tumors (mean size 10.5 cm) unrelated to viral hepatitis or cirrhosis. Our CGH analysis detected genomic imbalances in 42% of HCCs. The common aberrations included DNA gains of 1q, 9p, and 8q and DNA losses of 17p, 13q, 9q, 4q, and 11q. Also, we detected trisomies 8, 9, 18 and 21, which have not been reported previously. Gains and losses of DNA found in this study probably involve oncogenes and tumor suppressor genes that play a role in the puzzle of hepatocarcinogenesis. This study also suggests a possible link between the size of the tumor and the burden of genetic changes.

Adult↗