Showing 5 results for In Situ Hybridization
Mohammad Reza Noori-Daloii, Nazanin Jalilian,
Volume 68, Issue 1 (4-2010)
Abstract
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Since the recognition of true number of human
chromosomes in 1956,
many techniques have been developed to detect chromosomal aberrations. A number of those,
such as karyotyping and fluorescence in situ hybridization (FISH), are valuable tools
in both research and diagnostics. But these techniques have defects that limit
their application. One of the important limitations is resolution resolution
limitations make it impossible to detect small aberrations. The other major
defect is the disability to analyze whole genome. In 1997 Solinas-Toldo
introduced a new technique that could cover other techniques' defects. This new
technique called microarray-based comparative genomic hybridization (array CGH). Array CGH, with the powerful
resolution of FISH
and also the ability of whole genome analysis in single experiment accelerated
the genetic research. Array CGH has resulted in to a great progress in oncology and
genetic disorders research. In addition, this technique has the ability to be
used in diagnostics too. This review article, witch include the data of recent
published papers and our experiences, gives an overview of the array CGH and compare it with
the other molecular cytogenetic techniques. Its application in oncology and
genetic disorder is also discussed.
Kosari F, Yarigarravesh Hr, Rezvan M,
Volume 70, Issue 6 (9-2012)
Abstract
Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma. There are various types of DLBCL including immunoblastic and centroblastic. Epstein-Barr virus (EBV) is a member of Herpes virus family found in all human populations inducing different lymphoproliferative disorders. The role of EBV in the development of DLBCL is known. Multiple laboratory methods are available for detecting EBV. This study was conducted to determine the correlation of EBV with DLBCL in samples referred to pathology ward in Shariati and Sina Hospitals by chromogenic in situ hybridization (CISH) method.
Methods: In this case/control study, pathological specimens of 50 patients with DLBCL as well as 50 reactive lymph nodes and tonsils (control group) were collected from archives of Shariati and Sina Hospitals and were evaluated for EBV encoded RNA (EBER) expression based on CISH method. A peptide nucleic acid (PNA) EBV probe (Dakocytomatin) was used while all the processes were done in RNAase-free conditions using RNAase-free water, sterile gloves and samplers.
Results: Out of fifty specimens in the case group, eight were positive for EBER in comparison with two in the control group (P=0.046). No statistically significant difference was observed between intranodal or extranodal samples (P=0.736) or between males and females (P=0.0746).
Conclusion: Our study showed that EBV positivity for EBER in patient with DLBCL could be determined more effectively by CISH method than immunohistochemistry (IHC). Comparative analysis between CISH, PCR and IHC methods is recommended.
Zahra Nozhat , Mehdi Hedayati ,
Volume 73, Issue 3 (6-2015)
Abstract
In situ hybridization (ISH) is a method that uses labeled complementary single strand DNA or RNA to localize specific DNA or RNA sequences in an intact cell or in a fixed tissue section. The main steps of ISH consist of: probe selection, tissue or sample preparation, pre-hybridization treatment, hybridization and washing, detection and control procedure. Probe selection is one of the important aspects of successful hybridization. ISH sensitivity and specificity can be influenced by: probe construct, efficiency of labeling, percentage of GC, probe length and signal detection systems. Different methods such as nick translation, random priming, end tailing and T4 DNA polymerase replacement are used for probe generation. Both radioactive and non-radioactive labels can be used in order to probe labeling. Nucleic acid maintenance in samples, prevention of morphological changes of samples and probe penetration into tissue section are the main aims of sample preparation step. Then, a small amount of solution containing probe, is added on slides containing tissue sections for hybridization process, then slides are incubated overnight. Next day, washes are carried out to remove the probes which are not bound to target DNA or RNA. Finally, in order to be sure that the observed labeling is specific to the target sequence, using several control procedures is very important. Various techniques based on ISH consist of: Fluorescence in situ hybridization (FISH), chromogenic in situ hybridization (CISH), genomic in situ hybridization (GISH), comparative genomic hybridization (CGH), spectral karyotyping (SKY) and multiplex fluorescence in situ hybridization (MFISH). One of the most common techniques of ISH is fluorescence in situ hybridization. FISH can be used to: 1) detect small deletions and duplications that are not visible using microscope analysis, 2) detect how many chromosomes of a certain type are present in each cell and 3) confirm rearrangements that are suspected after microscope analysis. In this technique different fluorescent labels are attached to the probes. In this review article ISH, its different types, their application, advantages and disadvantages have been considered.
Malihea Khaleghian , Issa Jahanzad , Abbas Shakoori , Neda Zargari, Maryam Mohamadi , Cyrus Azimi ,
Volume 73, Issue 4 (7-2015)
Abstract
Background: The incidence rate of gastric cancer in Western countries has shown a remarkable decline in recent years although it is still the almost common cancer between men in Iran. The proto-oncogene MYC, located at 8q24.1, regulates almost 15% of human genes and is activated in 20% of all tumors. MYC amplification and overexpression of its protein product are observed in 15-30% of gastric neoplasia. The objective of this study was to find the preference of CISH or IHC in the diagnosis and prognosis of gastric cancer.
Methods: In this cross-sectional investigation, 102 paraffin blocks samples of Iranian patients with gastric cancers were studied. All the patients had undergone primary surgical resection at the Cancer Institute Hospital, Tehran University of Medical Sciences from 1987 to 1993. CISH and IHC techniques were applied to the samples. CISH was carried out on 3-µm-thick tissue sections and with a ZytoDot CISH Implementation Kit (ZytoVision GmbH, Germany). IHC was down using the HRP method with the monoclonal antibody. A universal peroxidase-conjugated secondary antibody kit was used for the detection system. All samples were gastric adenocarcinoma and were selected randomly.
Results: Our data revealed that both diffuse and intestinal types of gastric cancer occurred significantly in men more than women. Our results showed an indication of some correlation between grades and CISH results, although the difference was not significant. Our data also showed that CISH+ patients (43.1%) were more frequent in comparison with IHC+ patients (14.7%). There was a correlation between CISH and IHC. This result revealed that there was a significant difference between grades and IHC. There was also no statistically significant difference between CISH amplification in diffuse and intestinal types.
Conclusion: Our conclusion is that for the treatment, management of stomach cancer, and monitoring of progress and prognosis of the tumor that is almost important for patients and clinicians, CISH test is a better and feasible to IHC test, with regards to sensitivity and specificity.
Fatemeh Nevisi , Marjan Yaghmaie , Hossein Pashaiefar , Kamran Alimoghaddam , Masoud Iravani, Gholamreza Javadi , Ardeshir Ghavamzadeh ,
Volume 77, Issue 11 (2-2020)
Abstract
Background: Gastric cancer (GC) is considered as one of the most common types of cancer worldwide with poor prognosis and generally limited treatment options. Recent studies have indicated that HER2, MDM2, MYC, MET, and TP53 play an important role in the development of gastric cancer. Therefore, the aim of this study was to evaluate the incidence of amplification/deletion of these genes in patients with gastric cancer.
Methods: In this descriptive study, a total of 37 gastric cancer tissue samples from GC patients including 23 males (62.2%) and 14 females (37.8%) referred to the Hematology-Oncology and Stem Cell Research Center of Shariati Hospital, Tehran, from March 2015 to February 2016 were evaluated. The patient's age at diagnosis ranged from 33 to 85 years (median: 65 years). The amplification pattern of HER2, MDM2, MYC and MET genes and TP53 deletion were investigated by fluorescence in situ hybridization (FISH) technique performed on 3 to 5 micron section obtained from formalin-fixed and paraffin-embedded cancer tissues.
Results: The tumors were preferably identified at the distal stomach (54.05%) in comparison to tumors arising from the gastric cardia. The tumor size varied between 2 and 5 cm (average, 3.5 cm). Seven of the cases (19%) had advanced tumors at the time of diagnosis. HER2, MDM2, MYC, MET and TP53 copy number alteration were successfully determined in all samples obtained from the GC patients. HER2, MDM2, and c-MYC genes were amplified in 2 (5.41%), 1 (2.7%) and 3 (8.11%) of 37 patient samples, however, MET gene amplification and TP53 deletion were not observed in the obtained GC tissue samples. Co-amplification of HER2, MDM2, and MYC genes, and co-amplification of HER2 and MYC genes were detected in one patient.
Conclusion: The results of this study indicate the low frequency of MDM2, HER2 and MYC genes in gastric cancer patient and their copy number alterations may provide diagnostic and prognostic marker for GC patients.
