Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tissue microdissection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed2005

Survivin, a potential biomarker in the development of Barrett's adenocarcinoma.

BACKGROUND: Survivin, a member of the inhibitor-of-apoptosis family, is reported to be overexpressed in esophageal cancer but no data are available about its status in the metaplastic/dysplastic sequence. The aim of this study was to measure survivin gene expression in normal squamous/columnar epithelium and in the various stages of development of Barrett's adenocarcinoma. METHODS: Endoscopic biopsy or operative specimen samples from 5 tissue types were analyzed: (1) squamous epithelium from 3 cm above the gastroesophageal junction in patients with a negative pH study and no histologic injury (n = 17, pH- control); (2) antral tissue from patients with no evidence of Barrett's, dysplasia, or cancer (n = 29, antral control); (3) specialized intestinal metaplasia from patients with Barrett's esophagus (n = 16; Barrett's group); (4) low- or high-grade dysplasia (n = 12, dysplasia group), and (5) adenocarcinoma (n = 45 cancer group). After laser-capture microdissection cellular RNA was extracted from each tissue and reverse transcribed to complementary DNA. Expression levels of survivin were measured by reverse-transcription polymerase chain reaction. RESULTS: Survivin gene expression was greater in columnar (antral) compared with squamous (pH-) control tissues (P = .03). Expression in quiescent Barrett's epithelium was similar to both control tissues. Expression levels in dysplastic epithelium were greater than in squamous control (P = .01) and Barrett's tissues (P = .04), but not higher than columnar control tissues, whereas expression in adenocarcinoma was greater than all tissues except dysplasia (P < .001). CONCLUSIONS: Survivin expression may be a biomarker in the development of Barrett's adenocarcinoma that is able to distinguish between quiescent Barrett's, dysplastic Barrett's, and Barrett's adenocarcinoma.

Adenocarcinoma↗
PubMed2006

Establishment of a protocol for the gene expression analysis of laser microdissected rat kidney samples with affymetrix genechips.

Laser microdissection in conjunction with microarray technology allows selective isolation and analysis of specific cell populations, e.g., preneoplastic renal lesions. To date, only limited information is available on sample preparation and preservation techniques that result in both optimal histomorphological preservation of sections and high-quality RNA for microarray analysis. Furthermore, amplification of minute amounts of RNA from microdissected renal samples allowing analysis with genechips has only scantily been addressed to date. The objective of this study was therefore to establish a reliable and reproducible protocol for laser microdissection in conjunction with microarray technology using kidney tissue from Eker rats p.o. treated for 7 days and 6 months with 10 and 1mg Aristolochic acid/kg bw, respectively. Kidney tissues were preserved in RNAlater or snap frozen. Cryosections were cut and stained with either H&E or cresyl violet for subsequent morphological and RNA quality assessment and laser microdissection. RNA quality was comparable in snap frozen and RNAlater-preserved samples, however, the histomorphological preservation of renal sections was much better following cryopreservation. Moreover, the different staining techniques in combination with sample processing time at room temperature can have an influence on RNA quality. Different RNA amplification protocols were shown to have an impact on gene expression profiles as demonstrated with Affymetrix Rat Genome 230_2.0 arrays. Considering all the parameters analyzed in this study, a protocol for RNA isolation from laser microdissected samples with subsequent Affymetrix chip hybridization was established that was also successfully applied to preneoplastic lesions laser microdissected from Aristolochic acid-treated rats.

Animals↗
PubMed1979

Correlation in the human aorta of APO B fractions with tissue cholesterol and collagen content.

The amounts of buffer- and Triton-extracted apo B (LDL-protein), as well as the sum of these two fractions, were correlated with the total tissue cholesterol and hydroxyproline content (as a measure of collagen) in grossly normal intima, fatty streaks, and fibrous plaques of human aortas obtained at autopsy. Quantitative values of buffer- and Triton-extracted apo B were obtained by sequentially extracting homogenates of aortic intima with an aqueous buffer and one containing Triton X-100, and measuring the apo B content in each extract by an electroimmunoassay relative to plasma LDL or Triton-treated LDL. Significant positive correlations were obtained between the following: tissue cholesterol and both buffer-extracted and total-extracted apo B in grossly normal intima; tissue cholesterol and Triton-extracted apo B in microdissected fibrotic caps and cores of fibrous plaques, as well as in whole plaques. A positive correlation was also obtained between tissue cholesterol and total-extracted apo B in the necrotic core. A significant negative correlation was found between Triton-extracted apo B and collagen in whole plaques. The calculated mean percent of total tissue cholesterol in the different aortic regions that could be present as part of an intact LDL particle were: 100% in grossly normal intima, 16% in fatty streaks, and 11% in fibrous plaques. The positive correlation between Triton-extracted apo B and cholesterol in plaques suggests one or both of the following: the extracellular pool of cholesterol or some material increasing concurrently with cholesterol interacts with apo B or another part of the LDL particle; or the apo B containing lipoprotein is trapped in the hydrophobic environment of extracellular lipid. Both possibilities would render the particle less soluble in aqueous buffers. The negative correlation between Triton-extracted apo B and tissue collagen and the lack of a significant correlation between buffer-extracted apo B and collagen content suggests that collagen is probably not responsible for apo B retention in the aortic intima.

Adult↗
PubMed1986

Three-dimensional visualization of the intraganglionic structures of the rat myenteric plexus: scanning electron microscopy with the connective tissue digestion method.

The rat myenteric plexus was chemically microdissected and the internal structures of the ganglia were demonstrated under a scanning electron microscope. The present preparation offers a view of the three-dimensional features of ganglion cells and permits their surface structures and the size and pattern of varicosities to be observed. Numerous finger-like processes were observed on the cell bodies of the studded neurons in close relationship with the varicose axons. The intramuscular branches of the plexus were also microdissected and their running pattern was observed.

Animals↗
PubMed2000

Gene expression profiles in squamous cell carcinomas of the oral cavity: use of laser capture microdissection for the construction and analysis of stage-specific cDNA libraries.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer among men in the developed world affecting the oral cavity, salivary glands, larynx and pharynx. Utilizing tissue from patients with HNSCC, we sought to systematically identify and catalog genes expressed in HNSCC progression. Here, we demonstrate the successful use of laser capture microdissection for procuring pure populations of cells from patient tissue sets comprised of oral squamous cell carcinomas (OSCCs) and matching normal tissue. From the estimated 5000 cells procured for each sample, we were able to extract total RNA (14.7-18.6 ng) of sufficient quality to transcribe GAPDH by reverse transcriptase-polymerase chain reaction (RT-PCR). The RNA was used for the synthesis of blunt-ended, double-strand complementary DNAs (cDNAs) by oligo (dT)-mediated reverse transcription, followed by addition of linkers. Primers specific for these linkers with uracil deglycosylase-compatible ends were used to amplify these cDNAs by PCR and the product was subcloned into the pAMP10 cloning vector. Ninety-six clones from each of six libraries were randomly sequenced and results indicated that 76-96% of the inserts represent either anonymous expressed sequence tags (ESTs) (25-48%), known genes (9-29%) or novel sequences (27-51%), respectively, with very little redundancy. These results demonstrate that high quality, representative cDNA libraries can be generated from microdissected OSCC tissue. Furthermore, these finding suggest the existence of at least 132 novel genes expressed in our cDNA libraries, which may have a role in the pathogenesis of HNSCC, and may represent novel markers for early detection as well as targets for pharmacological intervention in this disease.

Aged↗
PubMed2003

Navigated laser capture microdissection as an alternative to direct histological staining for proteomic analysis of brain samples.

Proteomic analysis of the brain is complicated by the need to obtain cells from specific anatomical regions, or nuclei. Laser capture microdissection (LCM) is a technique that is precise enough to dissect single cells within a tissue section, and thus could be useful for isolating specific brain nuclei for analysis. However, we and others have previously demonstrated that histological staining protocols used to guide LCM have detrimental effects on protein separation by two-dimensional electrophoresis (2-DE). Here we describe a new LCM method called navigated LCM. This microdissection method uses fixed but unstained tissue as starting material and thus enables us to avoid artifacts induced by tissue staining. By comparing 2-DE results obtained from fixed, unstained LCM brain tissue samples to those obtained from manually dissected samples, we demonstrated that this microdissection process gave similar protein recovery rates and similar resolution of protein spots on 2-DE gels. Moreover, matrix-assisted laser desorption/ionization-time of flight mass spectrometry analysis of selected spots from gels derived from control and fixed, LCM samples revealed that the fixation-LCM process had no effect on protein identification. Navigated LCM of tissue sections is therefore a practical and powerful method for performing proteomic studies in specifically defined brain regions.

Animals↗
PubMed2006

Tumor-associated endothelial cells display GSTP1 and RARbeta2 promoter methylation in human prostate cancer.

BACKGROUND: A functional blood supply is essential for tumor growth and proliferation. However, the mechanism of blood vessel recruitment to the tumor is still poorly understood. Ideally, a thorough molecular assessment of blood vessel cells would be critical in our comprehension of this process. Yet, to date, there is little known about the molecular makeup of the endothelial cells of tumor-associated blood vessels, due in part to the difficulty of isolating a pure population of endothelial cells from the heterogeneous tissue environment. METHODS: Here we describe the use of a recently developed technique, Expression Microdissection, to isolate endothelial cells from the tumor microenvironment. The methylation status of the dissected samples was evaluated for GSTP1 and RARbeta2 promoters via the QMS-PCR method. RESULTS: Comparing GSTP1 and RARbeta2 promoter methylation data, we show that 100% and 88% methylation is detected, respectively, in the tumor areas, both in epithelium and endothelium. Little to no methylation is observed in non-tumor tissue areas. CONCLUSION: We applied an accurate microdissection technique to isolate endothelial cells from tissues, enabling DNA analysis such as promoter methylation status. The observations suggest that epigenetic alterations may play a role in determining the phenotype of tumor-associated vasculature.

Journal Article↗
PubMed1995

Monoclonality in gastric lymphoma detected in formalin-fixed, paraffin-embedded endoscopic biopsy specimens using immunohistochemistry, in situ hybridization, and polymerase chain reaction.

Diagnosis of gastric malignant lymphoma remains a challenge, especially when the tissue source is endoscopic biopsy specimens. Once an atypical lymphoid infiltrate is found, demonstration of clonality is the key to establishing a diagnosis of the disease. For this purpose, we evaluated the usefulness of immunohistochemistry, in situ hybridization, and polymerase chain reaction (PCR) using formalin-fixed, paraffin-embedded endoscopic materials from 20 patients with B-cell malignant lymphomas. Template DNA for PCR was obtained by microdissecting Giemsa-stained sections using a serial hematoxylin and eosin section as a guide. Clonal rearrangement bands were demonstrated in 15 of 20 cases (75%) by PCR, whereas expression of monotypic light-chain mRNA was detected in seven of 20 (35%) by in situ hybridization and monotypic light-chain restriction in four of 20 (20%) by conventional immunohistochemistry. Although less sensitive than PCR, in situ hybridization was useful for localizing the expression of target mRNAs with cellular accuracy and with low background staining. In addition, two cases were found to be monoclonal only by in situ hybridization, and not by PCR. The results showed that clonal proliferation is detected with the greatest sensitivity with PCR using small routinely processed biopsy specimens and that a difficulty with the PCR method in terms of cellular localization was partially overcome using a microdissection procedure that provided at least tissue-level accuracy.

Base Sequence↗
PubMed1994

Nuclear accumulation of p53 protein correlates with mutations in the p53 gene on archival paraffin-embedded tissues of human breast cancer.

Fifty invasive ductal carcinomas of the breast were analyzed by immunohistochemistry, polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and direct sequencing after microdissection of conventional formalin-fixed, paraffin-embedded tissues. A highly significant association between the presence of p53 gene mutation and nuclear accumulation of p53 protein was found (P < 0.0001). Of 13 tumors that demonstrated p53 gene mutations, 11 (84.6%) showed nuclear accumulation of p53 protein. However, of 37 tumors in which gene mutations were not detected, only 5 (13.5%) showed nuclear accumulation of p53 protein. There was a statistically significant association between the nuclear accumulation of p53 protein and a higher histological grade (P < 0.001) or mitotic index (P < 0.01). In addition, gene mutations had a statistically significant association with a higher histological grade (P < 0.05) or mitotic index (P < 0.0001). Therefore, p53 abnormalities might be associated with an aggressive phenotype in breast cancer. We conclude that the immunohistochemical detection of nuclear p53 protein accumulation is highly associated with p53 gene mutations in archival paraffin-embedded tissues, and that this method is useful for rapid screening of p53 abnormalities.

Base Sequence↗
PubMed2004

Distinctive pattern of LINE-1 methylation level in normal tissues and the association with carcinogenesis.

Genome-wide losses of DNA methylation have been regarded as a common epigenetic event in malignancies and may play crucial roles in carcinogenesis. Limited information is available on the global methylation status in normal tissues and other cancer types beyond colonic carcinoma. Here we applied the combined bisulfite restriction analysis PCR to evaluate the methylation status of LINE-1 repetitive sequences in genomic DNA derived from microdissected samples from several human normal and neoplastic tissues. We found that methylation of LINE-1 in leukocytes was independent of age and gender. In contrast, normal tissues from different organs showed tissue-specific levels of methylated LINE-1. Globally, most carcinomas including breast, colon, lung, head and neck, bladder, esophagus, liver, prostate, and stomach, revealed a greater percentage of hypomethylation than their normal tissue counterparts. Furthermore, DNA derived from sera of patients with carcinoma displayed more LINE-1 hypomethylation than those of noncarcinoma individuals. Finally, in a colonic carcinogenesis model, we detected significantly greater hypomethylation in carcinoma than those of dysplastic polyp and histological normal colonic epithelium. Thus, the methylation status is a unique feature of a specific tissue type and the global hypomethylation is a common epigenetic process in cancer, which may progressively evolve during multistage carcinogenesis.

Base Sequence↗
PubMed2004

Decreased transferrin receptor expression by neuromelanin cells in restless legs syndrome.

BACKGROUND: Restless legs syndrome (RLS) is a sensory-movement disorder affecting 5 to 10% of the population. Its etiology is unknown, but MRI analyses and immunohistochemical studies on autopsy tissue suggest the substantia nigra (SN) of patients with RLS has subnormal amounts of iron. METHODS: Neuromelanin cells from the SN of four RLS and four control brains were isolated by laser capture microdissection, and a profile of iron-management protein expression was obtained by immunoblot analysis. Binding assays for iron regulatory protein activity were performed on cell homogenates. RESULTS: Ferritin, divalent metal transporter 1, ferroportin, and transferrin receptor (TfR) were decreased in RLS neuromelanin cells compared with control. Transferrin was increased in RLS neuromelanin cells. This protein profile in RLS neuromelanin cells is consistent with iron deficiency with the exception that TfR expression was decreased rather than increased. The concentration and activity of the iron regulatory proteins (IRP1 and IRP2) were analyzed to determine whether there was a functional deficit in the post-transcriptional regulatory mechanism for TfR expression. Total IRP activity, IRP1 activity, and IRP1 protein levels were decreased in RLS, but total IRP2 protein levels were not decreased in RLS. CONCLUSION: Restless legs syndrome may result from a defect in iron regulatory protein 1 in neuromelanin cells that promotes destabilization of the transferrin receptor mRNA, leading to cellular iron deficiency.

Aged↗
PubMed1999

Molecular genetic testing from paraffin-embedded tissue distinguishes nonmolar hydropic abortion from hydatidiform mole.

BACKGROUND: Diagnosis of hydatidiform mole by histology and ploidy analysis is limited by overlap of criteria for nonmolar hydropic abortion, complete mole, and partial mole. With early presentation, diagnosis is difficult due to limited tissue and lack of clinical features. Accurate diagnosis of these entities is important for both prognosis and patient management. We assessed a polymerase chain reaction (PCR) assay for polymorphic short tandem repeats (STR) for discrimination between nonmolar hydropic abortion, complete mole, and partial mole based on the genetic composition of molar pregnancies. METHODS: Seventeen cases of products of conception (POC) diagnosed by histology and flow cytometry ploidy analysis were studied retrospectively. PCR was performed using maternal and chorionic villus DNA extracted from microdissected, formalin-fixed, paraffin-embedded tissue sections. Allelic patterns for up to eight well-characterized polymorphic STR loci were determined using the GenePrint Fluorescent STR System (Promega Corporation, Madison, WI). The presence of three villus alleles at a single locus was interpreted as partial mole. Detection of only one allele in the villi, different from all maternal allele(s) at the same locus, was interpreted as a complete mole. RESULTS: This technique identified eight complete moles previously diagnosed as complete mole (3), hydatidiform mole, otherwise unspecified (1), hydropic villi (2), hydropic villi versus partial mole (1), and partial mole (1). The diagnoses of five partial moles by the molecular assay were consistent with the diagnoses by histology and flow cytometry. One nonmolar gestation was identified, which had been diagnosed previously as hydropic villi. In three cases, maternal DNA amplification was insufficient for definitive diagnosis. CONCLUSION: Molecular genetic testing of POC from paraffin-embedded tissue accurately distinguishes complete mole, partial mole, and nonmolar hydropic abortion. Identification of triploidy by flow cytometry can confirm a histological impression of partial mole. Histological and ploidy analysis of POC results in underdiagnosis of complete moles.

Abortion, Spontaneous↗
PubMed1988

Quantitative histochemical determination of Na+ and K+ in microscopic samples using carbon furnace atomic absorption spectrometry.

Carbon furnace atomic absorption spectrometry was used to measure the Na and K content of freeze-dried microscopic tissue samples. This method was sufficiently sensitive to measure pmol amounts of Na and K from tissue weighing 10-60 ng. Within the spatial resolution of the microdissection procedure, ion diffusion that might occur during cryosectioning, freeze-drying, and dissection of the tissue did not seem to be a problem. Data obtained with this methodology were in agreement with previously reported values of the Na and K content of various tissues, thus supporting the usefulness of this quantitative histochemical technique.

Animals↗
PubMed2001

Piffalls in diagnostic molecular pathology--significance of sampling error.

Today, molecular diagnostic tests are widely used in clinical medicine with polymerase chain reaction (PCR)-based techniques being of particular interest. In tissue specimens, however, false-positive and false-negative results can be obtained if pathomorphological and processing aspects are not considered. We therefore studied the impact of tissue sampling in three widely used diagnostic tests: (1) assessment of clonality in B-cell non-Hodgkin's lymphoma, (2) analysis of microsatellite instability (MSI) in colorectal neoplasia, and (3) demonstration of mycobacterium tuberculosis. Tissue sections of routinely formalin-fixed and paraffin-embedded diagnostic specimens were taken, and the significance of sampling was systematically investigated using laser microdissection or processing of the entire section. PCR analyses were done according to standard protocols. False-positive pseudo-monoclonality was obtained in small gastrointestinal biopsies and in laser microdissected lymph follicles of non-neoplastic tonsils. False negativity (pseudo-stability) could be demonstrated in a case with hereditary rectal adenoma if whole tissue sections were taken without microdissection of the most dysplastic subareas. Demonstration of mycobacteria failed in tissue sections of a formalin-fixed lymph node that was positive after complete digestion or in fresh frozen material of the same patient. In diagnostic molecular pathology, sampling error is an important source of false-positive and false-negative results, particularly if disease- and tissue-specific morphological features, such as sample size, type of fixation, and intralesional heterogeneity, are ignored.

Clone Cells↗
PubMed2000

Molecular strategies to define HLA haplotype loss in microdissected tumor cells.

Loss of heterozygosity (LOH) of chromosome 6p21 is an important mechanism that generates HLA haplotype loss in various human tumors. This mechanism produces non-reversible HLA-deficient tumor cells that can escape T cell immune responses in peptide-vaccinated cancer patients. However, the exact frequency of this mechanism is still unknown, because contaminating stroma in solid tumor tissues masks the tumor DNA obtained from solid samples. A microdissection technique was applied to 4-8 microm sections of cryopreserved tumor tissues from a group of colorectal and laryngeal carcinomas. Fifteen patients were analyzed for the presence of LOH associated with the beta(2)-microglobulin gene in chromosome 15, and five patients for LOH associated with HLA genes in chromosome 6. In two cases, autologous metastasis tissue samples were also available. The patients were selected for showing an altered HLA class I tumor phenotype as determined by immunohistological techniques. DNA was obtained from this microdissected material and amplified in order to detect the presence or absence of nine previously selected microsatellite markers. HLA sequence based typing (SBT) was also applied to these microdissected DNA samples to define the HLA genotype. Microdissection greatly improved the definition of LOH, with nearly 100% signal reduction in one of the alleles. In addition, this procedure allowed us to detect beta(2)-microglobulin LOH in tumors that expressed some HLA molecules. Our data indicate that this procedure can be successfully applied to microdissected samples from solid tumors, thus enhancing the power and sensitivity of LOH detection.

Colorectal Neoplasms↗
PubMed2005

Comparative proteomic analysis using samples obtained with laser microdissection and saturation dye labelling.

Comparative proteomic methods are rapidly being applied to many different biological systems including complex tissues. One pitfall of these methods is that in some cases, such as oncology and neuroscience, tissue complexity requires isolation of specific cell types and sample is limited. Laser microdissection (LMD) is commonly used for obtaining such samples for proteomic studies. We have combined LMD with sensitive thiol-reactive saturation dye labelling of protein samples and 2-D DIGE to identify protein changes in a test system, the isolated CA1 pyramidal neurone layer of a transgenic (Tg) rat carrying a human amyloid precursor protein transgene. Saturation dye labelling proved to be extremely sensitive with a spot map of over 5,000 proteins being readily produced from 5 mug total protein, with over 100 proteins being significantly altered at p < 0.0005. Of the proteins identified, all showed coherent changes associated with transgene expression. It was, however, difficult to identify significantly different proteins using PMF and MALDI-TOF on gels containing less than 500 mug total protein. The use of saturation dye labelling of limiting samples will therefore require the use of highly sensitive MS techniques to identify the significantly altered proteins isolated using methods such as LMD.

Alzheimer Disease↗
PubMed2003

Osteopontin is down-regulated in hydatidiform mole.

OBJECTIVE: Osteopontin (OPN) is a glycoprotein of the extracellular matrix that can bind to different types of receptors including integrins and CD44 receptors. Multiple binding affinity enables OPN to play a role in many physiological and pathological processes. OPN contributes to tumorigenesis in several types of cancers. OPN is also expressed by the endometrium and by trophoblast cells of the chorionic villus in human placenta, where OPN may regulate implantation and placentation in early pregnancies by promoting cell-cell interactions, adhesion, spreading, and migration of trophoblast. Our purpose was to determine the expression of OPN mRNA and protein in hydatidiform mole and in normal placenta of comparable gestational age. METHODS: A total of 13 fresh tissues from complete hydatidiform moles, 2 from partial hydatidiform moles, and 9 from normal placentas were analyzed by performing quantitative real-time PCR on microdissected trophoblast cells and immunohistochemistry on frozen sections of tissue. RESULTS: Our results showed significantly lower expression of OPN mRNA and protein in hydatidiform mole, and in particular complete mole (P = 0.001 by real-time PCR and P < 0.001 by immunohistochemistry) as compared to nermal placenta. CONCLUSION: Although precise molecular mechanisms of gestational trophoblastic diseases have not yet been determined, down-regulation of osteopontin may play an important role in the pathogenesis of molar pregnancy.

Dissection↗
PubMedDate not supplied

Analysis of the HER2/neu gene amplification in microdissected breast cancer tumour samples.

The HER2/neu oncogene has been reported to be amplified in > 20% of invasive ductal carcinomas. In order to investigate the HER2/neu status in pure populations of breast cancer cells, a laser capture microdissection (LCM) system was used. Formalin-fixed paraffin-embedded breast tissue areas corresponding to normal ducts, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) were microdissected and genomic DNA was isolated by a modified proteinase K- phenol extraction method and subjected to PCR for HER2/neu analysis. One hundred % concordance for detection of the HER2/neu gene amplification was found between immunohistochemistry and PCR used in combination with LCM. Our results indicated that LCM is a powerful technique for isolating pure populations of cells from paraffin-embedded tissue sections and that these cells can be used to study genomic alterations at the DNA level.

Base Sequence↗