Allicin Could Potentially Alleviate Oral Cancer Pain by Inhibiting “Pain Mediators” TNF-alpha,IL-8, and Endothelin

To evaluate the effects of allicin on mediators of pain secreted by oral cancer cells in vitro, single-cell suspensions were prepared by enzymatic method from oral squamous cell carcinoma (OSCC). Cancer stem cells were isolated by the CD133+ selection method with magnetic cell sorting. Stemness markers were checked in both cancer cells and cancer stem cells by RT-PCR. Comparative analysis of pain mediators TNF-alpha, IL-8, and endothelin at both RNA and protein levels for normal epithelial cells, cancer cells, and cancer stem cells was carried out with and without allicin treatment. CD133 and CD44 expression levels were checked in cancer cells and cancer stem cells flow cytometrically. Allicin inhibited both gene and protein expression of TNF-alpha, IL-8, and endothelin in both cancer cells and cancer stem cells. Allicin is more likely to be a promising treatment in alleviating the levels of pain and inflammation in OSCCs.     

Flow cytometric enrichment for respiratory epithelial cells in sputum.

BACKGROUND: Induced sputum, in contrast to bronchoscopic biopsies and lavages, is an easily obtained source of biological specimens. However, obtaining abnormal exfoliated cells for detailed molecular studies is limited because respiratory epithelial cells comprise only about 1% of sputum cell populations. METHODS: We developed a multiparameter flow sorting strategy to purify epithelial cells from nonepithelial sputum cells, using anti-cytokeratin antibody AE1/AE3 to recognize human epithelial cells and DAPI to stain DNA. We excluded cells with a high degree of side-scatter, which were composed predominantly of squamous cells and contaminating macrophages. The remaining cytokeratin-positive respiratory epithelial cells were then sorted based on anti-cytokeratin (PE) vs DNA (DAPI) parameters. RESULTS: In this proof of principle study, the AE1AE3 cytokeratin/DNA flow sorting strategy enriched rare diploid respiratory epithelial cells from an average of 1.1% of cells in unsorted induced sputum samples to average purities of 42%. Thus, AE1AE3 flow-sorting results in a 38-fold enrichment of these cells. CONCLUSIONS: We report a multiparameter flow cytometric assay to detect and enrich rare respiratory epithelial cells from induced sputum samples to average purities of 42%. With further development, this methodology may be useful as part of a molecular screening approach of populations at high risk for lung cancer.     

Acquisition of viral DNA sequences in target organs of chickens infected with avian myeloblastosis virus.

The distribution of oncornavirus DNA sequences in various tissues of normal chickens and of chickens with leukemia or kidney tumors induced by avian myeloblastosis virus (AMV) was analyzed by DNA-RNA hybridization using 35S AMV RNA as a probe. All the tissues from normal chickens which were tested contained the same average cellular concentration of endogenous oncornavirus DNA. In contrast, different tissues from lekemic chickens and from chickens bearing kidney tumors contained different concentrations of AMV homologous DNA: in some tissues there was no increase whereas other tissues acquired additional AMV-specific DNA sequences. The increase was the greatest in tissues which can become neoplastic after infection, such as myeloblasts, erythrocytes, and kidney cells. It was directly demonstrated that DNA from AMV-induced kidney tumor contains AMV sequences which are absent in DNA from normal cells. A similar finding had been previously obtained with leukemic cells (15). 3H-labeled 35S RNA from purified AMV was exhaustively hybridized with an excess of normal chicken DNA to remove all the viral RNA sequences which are complementary to DNA from uninfected cells. The 3H-labeled RNA which failed to hybridize was isolated by hydroxylapatite column chromatography which separates DNA-RNA hybrids from single-stranded RNA. The residual RNA hybridized to chicken kidney tumor DNA but did not rehybridize with normal chicken DNA.     

Comparison of detergent-solubilized membrane and soluble proteins from flow cytometrically sorted X- and Y-chromosome bearing porcine spermatozoa by high resolution 2-D electrophoresis

The only known and measurable difference between X- and Y-chromosome bearing spermatozoa is the small difference in their DNA content. The X sperm in the human carry 2.8% more DNA than the Y sperm, while in domestic livestock this difference ranges from 3.0 to 4.2%. The only successful sperm separation method, flow cytometric sorting, is based on this difference in DNA content. Using this technique, X and Y sperm populations with purities greater than 90% can be obtained. The number of spermatozoa that can be sorted in a given time period, however, is too low for application of this technique in routine artificial insemination. Therefore, the search for a marker other than DNA to differentiate between X and Y sperm remains of interest in order to develop a method for large scale X and Y sperm separation. The aim of the present study was to investigate whether porcine X and Y sperm contain some difference in their plasma membrane proteins. The flow cytometric sorting of sperm enabled a direct comparison of the proteins of the X and Y sperm populations High resolution two-dimensional (2-D) electrophoresis was used; however, adaptations were needed to enable its use for analysis of proteins of flow cytometrically sorted sperm, both in the sorting procedure, membrane protein solubilization, and in the 2-D electrophoresis. Up to 1,000 protein spots per gel could be detected and quantified. Comparison of the 2-D protein patterns revealed differences in protein spots between sperm of two individual boars. However, no differences in protein spots between the X and Y sperm fractions were found. These results provide additional support for the view that X- and Y-chromosome bearing spermatozoa are phenotypically identical, and cast doubt on the likelihood that a surface marker can provide a base for X and Y sperm separation. © 1996 Wiley-Liss, Inc.     

Complementary DNA cloning of a novel epithelial cell marker protein, HME1, that may be down-regulated in neoplastic mammary cells.

A full-length complementary DNA clone from a normal human mammary epithelial cell (strain 184) encoding a 25-kilodalton protein, HME1, was isolated. Expression of HME1 RNA appears to be limited to epithelial cells. The HME1 sequence has extensive sequence homology with bovine 14-3-3 protein, which is an activator of tyrosine and tryptophan hydroxylase. However, the tissue distribution, arrangement of charged amino acids, and location of potential phosphorylation sites of HME1 differ from those of 14-3-3. Compared with normal mammary epithelial cells, expression of HME1 RNA was dramatically low in two cell lines derived from human mammary carcinoma that were examined, and in a line of normal mammary epithelial cells transformed by oncogenes. HME1 therefore appears to be a cellular differentiation marker that may be down-regulated during neoplastic transformation.     

Integrating cytomics and proteomics

Systems biology along with what is now classified as cytomics provides an excellent opportunity for cytometry to become integrated into studies where identification of functional proteins in complex cellular mixtures is desired. The combination of cell sorting with rapid protein-profiling platforms offers an automated and rapid technique for greater clarity, accuracy, and efficiency in identification of protein expression differences in mixed cell populations. The integration of cell sorting to purify cell populations opens up a new area for proteomic analysis. This article outlines an approach in which well defined cell analysis and separation tools are integrated into the proteomic programs within a core laboratory. In addition we introduce the concepts of flow cytometry sorting to demonstrate the importance of being able to use flow cytometry as a cell separation technology to identify and collect purified cell populations. Data demonstrating the speed and versatility of this combination of flow cytometry-based cell separation and protein separation and subsequent analysis, examples of protein maps from purified sorted cells, and an analysis of the overall procedure will be shown. It is clear that the power of cell sorting to separate heterogeneous populations of cells using specific phenotypic characteristics increases the power of rapid automated protein separation technologies.     

Isolation of pure human mucosal epithelium for RNA analysis

Techniques for isolating the desired cell populations from complex tissues are essential for characterizing cells through mRNA analysis. We established a procedure for isolating pure mucosal epithelium from the human alimentary tract. To do this, we made rotating hooks that hold mucosal strips and detach the epithelial sheets from the irregular mucosae surface in medium containing EDTA. An additional step using a cell strainer was required to reduce contamination by lymphoid cells. Sheets of epithelial cells were detached successfully from mucosal samples derived from five different parts of the human alimentary tract. Contamination by lymphoid cells or fibroblasts was monitored by competitive RT-PCR and was no more than 0.5% of the total cells. Total RNA yields were 12.5-17 micrograms for each separation, and the integrity of the RNA was as good as that of RNAs extracted from mucosa immediately after resection. In conclusion, our method permits isolation of RNAs from a pure population of epithelial cells that can be used for mRNA-based gene expression analyses.     

Paneth cell antimicrobial peptides: topographical distribution and quantification in human gastrointestinal tissues

Antimicrobial peptides and proteins are key effectors of innate immunity, expressed both by circulating phagocytic cells and by epithelial cells of mucosal tissues. In the human small intestine, Paneth cells are secretory epithelial cells that express the antimicrobials human alpha-defensin-5 (HD5), HD6, lysozyme and secretory phospholipase A(2) (sPLA(2)), and recent studies have implicated reduced HD5 and HD6 expression levels in the pathogenesis of ileal Crohn's disease. However, expression levels of these molecules have not been determined routinely by techniques that readily permit quantitative comparisons of their distribution between tissues and samples. Using quantitative real-time PCR with external standards and Northern blot analysis, we compared expression levels of mRNA encoding these four Paneth cell antimicrobial peptides, as well as circulating human neutrophil defensins in several different gastrointestinal tissues and the bone marrow. HD5 and HD6 were the most abundant antimicrobials expressed in the small intestine. The concentration of HD5 mRNA is approximately 5 x 10(5) copies per 10ng RNA in the jejunum and ileum; HD6 mRNA levels were about six times lower than those of HD5. With the exception of low levels in the pancreas (10(3) copies/10 ng RNA), the expression of HD5 and HD6 in tissues other than small intestine was at or below detectable limits. The expression of sPLA2 and lysozyme mRNA was observed in the small intestine (approximately, 3 x 10(3) and 9 x 10(3) copies/10 ng RNA, respectively), but also in several other tissues. Lysozyme expression was high in the duodenum (10(5) copies/10 ng RNA), and the protein localized to both Brunner's glands in the lamina propria and Paneth cells. By comparison, the hematopoietic alpha-defensins HNP1-3 mRNA were detected at 6 x 10(5) copies per 10 ng RNA in the bone marrow. These quantitative RT-PCR data from healthy tissues represents the first quantitative topographical assessment of antimicrobial expression in the gastrointestinal tract and provides a means to directly compare expression levels between healthy tissues and disease specimens for multiple antimicrobial peptides.     

Catalytically inactive,purified RNase H1: A specific and sensitive probe for RNA–DNA hybrid imaging

R-loops are three-stranded nucleic acid structures with both physiological and pathological roles in cells. R-loop imaging generally relies on detection of the RNA–DNA hybrid component of these structures using the S9.6 antibody. We show that the use of this antibody for imaging can be problematic because it readily binds to double-stranded RNA (dsRNA) in vitro and in vivo, giving rise to nonspecific signal. In contrast, purified, catalytically inactive human RNase H1 tagged with GFP (GFP-dRNH1) is a more specific reagent for imaging RNA–DNA hybrids. GFP-dRNH1 binds strongly to RNA–DNA hybrids but not to dsRNA oligonucleotides in fixed human cells and is not susceptible to binding endogenous RNA. Furthermore, we demonstrate that purified GFP-dRNH1 can be applied to fixed cells to detect hybrids after their induction, thereby bypassing the need for cell line engineering. GFP-dRNH1 therefore promises to be a versatile tool for imaging and quantifying RNA–DNA hybrids under a wide range of conditions.     

Ploidy levels in nonneoplastic and neoplastic thyroid cells

DNA levels in nonneoplastic and neoplastic human thyroid cells were studied by slide-cytophotometric and flow-cytophotometric techniques. Normal epithelial thyroid cells and cells from nonneoplastic thyroid disorders, i.e., toxic goiter, colloid goiter and chronic lymphocytic thyroiditis, had euploid (diploid, polyploid) DNA levels. The same was the case for benign tumors. Malignant tumors had either euploid DNA levels, indistinguishable from those in nonneoplastic and benign neoplastic cell populations, or aneuploid DNA levels. Taking into account the histopathologic diagnosis, clinical course and DNA level, the results indicate that DNA measurements in thyroid gland lesions are of limited diagnostic help but may contribute valuable prognostic information. To obtain representative and accurate DNA measurements, combined slide-cytophotometric and flow-cytophotometric techniques should be used.     

Identification and isolation of mouse type II cells on the basis of intrinsic expression of enhanced green fluorescent protein

The unique morphology and cell-specific expression of surfactant genes have been used to identify and isolate alveolar type II epithelial cells. Because these attributes can change during lung injury, a novel method was developed for detecting and isolating mouse type II cells on the basis of transgenic expression of enhanced green fluorescence protein (EGFP). A line of transgenic mice was created in which EGFP was targeted to type II cells under control of the human surfactant protein (SP)-C promoter. Green fluorescent cells that colocalized by immunostaining with endogenous pro-SP-C were scattered throughout the parenchyma. EGFP was not detected in Clara cell secretory protein-expressing airway epithelial cells or other nonlung tissues. Pro-SP-C immunostaining diminished in lungs exposed to hyperoxia, consistent with decreased expression and secretion of intracellular precursor protein. In contrast, type II cells could still be identified by their intrinsic green fluorescence, because EGFP is not secreted. Type II cells could also be purified from single-cell suspensions of lung homogenates using fluorescence-activated cell sorting. Less than 1% of presorted cells exhibited green fluorescence compared with >95% of the sorted population. As expected for type II cells, ultrastructural analysis revealed that the sorted cells contained numerous lamellar bodies. SP-A, SP-B, and SP-C mRNAs were detected in the sorted population, but T1alpha and CD31 (platelet endothelial cell adhesion molecule) were not, indicating enrichment of type II epithelial cells. This method will be invaluable for detecting and isolating mouse type II cells under a variety of experimental conditions.     

The lysosomal trafficking regulator interacting protein-5 localizes mainly in epithelial cells

Endocytosis, subsequent protein sorting into multivesicular bodies (MVBs), and eventual degradation in lysosomes compose an important mechanism for controlling protein expression on the plasma membrane. The lysosomal trafficking regulator interacting protein-5 (LIP5) is part of the complex protein machinery involved in MVB biosynthesis. LIP5 interacts with other players of the ESCRT machinery as well as with two known cargo proteins, AQP2 and EGFR, whose degradation is affected upon reduction of LIP5 expression. To investigate the expression and localization pattern of LIP5, we studied LIP5 protein expression in a mouse tissue panel and subjected various rodent and human tissues to immunohistochemistry. Immunoblotting revealed that, except for jejunum, LIP5 is expressed as a 42 kDa protein in all mouse tissues tested. Alternatively-spliced gene products could not be detected. Immunohistochemical studies revealed that in tissues positive for LIP5, LIP5 is detected in virtually all epithelial cells of the examined rodent and human tissues. The observed LIP5 expression in epithelial tissues suggests that LIP5 is of particular importance in the MVB sorting and degradation of proteins expressed in polarized cells.     

Two-color multiparametric method for flow cytometric DNA analysis of carcinomas using staining for cytokeratin and leukocyte-common antigen

Solid tumors contain heterogenous cell populations, resulting in flow cytometric (FCM) DNA quantitations of a mixture of tumor and host cells. Such mixed populations can result in dilution of the tumor cells by the host cells, in difficulty defining the diploid reference mean and in histogram peak overlap, precluding cell-cycle analysis. In this study, epithelial (tumor) cells and contaminating host cells in 100 consecutively accessioned human mammary and colorectal carcinomas were segregated in a multiparametric two-color FCM DNA analysis of intact, ethanol-fixed cells. These two carcinomas and bladder carcinomas contain a cytoskeleton of simple epithelium that is selectively stained with an FITC-labeled monoclonal antibody (MAb) to cytokeratin (CK: CAM 5.2-FITC). This MAb detects the CK 8, CK 18 and CK 19 consistently present in all layers of normal and neoplastic urothelium, colonic epithelium and mammary epithelium. Gating on CK in these tumors enables the nonstaining leukocytes, stromal fibroblasts and endothelial cells to be excluded from DNA analysis. A separate aliquot of each tumor evaluated was labeled with an MAb to leukocyte-common antigen (LCA-FITC) to serve as a patient-specific intrinsic diploid reference standard. Both the CK-labeled and LCA-labeled cells were then dual labeled for DNA with propidium iodide. This method (1) correctly identified the intrinsic diploid (LCA-positive) channel, allowing an accurate definition of normal cell DNA content for calculation of the DNA index; and (2) resulted in an increased sensitivity in the identification of both diploid and abnormal hyperdiploid tumor cell populations. It also (3) limited DNA cell cycle analysis to urothelial, colonic and mammary epithelial cells, the majority of which were neoplastic in carefully selected tumor samples. In addition, this method (4) clarified near-tetraploid populations that overlap the normal nonepithelial G2M region by diminishing the normal G2M peak and accentuating the aneuploid tetraploid G0G1 peak and (5) deconvoluted overlapping histograms composed of normal host and diploid-range or aneuploid tumor cells by gating on tissue-specific markers. This exclusion of host cells in both classes of tumors resulted in more accurate cell-cycle calculations in the former and allowed calculation of the S-phase fractions in the latter.     

Flow cytometric analysis of polysomaty and in vitro genetic instability in potato

The analysis of nuclear DNA contents in various tissues of potato genotypes showed that flow cytometry is a rapid method to characterize large populations of cells for polysomaty, that is, the occurrence of cells with normal DNA levels together with cells containing endoreduplicated nuclei. The proportion of endoreduplicated nuclei varied in different tissues and genotypes of potato. The analysis of callus and cell cultures showed that the temporal changes in nuclear DNA contents during in vitro growth can be followed and the degree of polyploidization quantified. It is concluded that flow cytometry is a highly suitable method to detect ploidy changes in differentiated plant tissues and calli which are often not amenable for chromosome number determination.     

Identification and preliminary characterization of two related proliferation-associated nuclear phosphoproteins

Two nuclear phosphoproteins, pp35 and pp32, were purified from A20 cells, a murine B-lymphoblastoid cell line. Initially detected by cross-reactivity with antibodies to human erythrocyte protein 4.1, the 35- and 32-kDa proteins were purified by sequential fractionation of non-ionic detergent cell lysates on DEAE-cellulose, high performance liquid chromatography (HPLC)-anion-exchange chromatography, and HPLC hydroxylapatite chromatography. By two-dimensional peptide mapping, pp35 and pp32 are related but do not appear to represent sequential proteolytic products. Both pp35 and pp32 appear to be associated with cell proliferation. Antibodies specific for pp35 and pp32 show prominent intranuclear staining in A20 cells but only focal staining in normal murine lymphoid tissues. Quantitative immunoblotting showed that both pp35 and pp32 are, respectively, expressed at 5.9 x 10(4) and 7.0 x 10(4) copies/cell in small, dense resting B lymphocytes, increasing approximately 12- and 7-fold after polyclonal stimulation with lipopolysaccharide. When normalized to total cell protein, this represents specific inductions of approximately 4- and 2-fold. Expression of both pp35 and pp32 is constitutively high in populations of neoplastic B cell lines; moreover, both are expressed in the nuclei of intestinal crypt epithelial cells but not in other epithelial compartments in the same sections, suggesting that forms of pp35 and pp32 may be expressed in additional tissues and associated with proliferation.     

Analytical and preparative electrophoresis of RNA in agarose-urea.

Agarose-6 m urea gels at neutral pH stained with ethidium bromide give high resolution of complex mixtures of RNA molecules. These RNA species can be readily distinguished from contaminating DNA, which does not have to be purified away from the RNA, and electrophoresis can be carried out using phenol-saturated deproteinated cellular extracts without loss of resolution. Individual RNA species can be extracted from the gels by freezing, thawing, and centrifugation; the RNA may then be purified by phenol extraction and ethanol precipitation. Such purified RNA is an excellent substrate for RNA-DNA hybridization and cell-free translation. In addition, the RNA can be easily transferred with high resolution from the agarose-6 m urea gels to diazobenzyloxymethyl paper for subsequent hybridization to labeled DNA.     

Immunohistochemical localization of sex hormone-binding globulin in normal and neoplastic breast tissue.

The distribution of sex hormone-binding globulin-like antigens (SHBG-LA) in normal and neoplastic human breast tissues was investigated by immunohistochemistry, employing a monospecific polyclonal antiserum against highly purified human SHBG and an avidin-biotin-peroxidase complex (ABC) method in formalin-fixed paraffin embedded tissue sections. In normal breast tissues the staining of SHBG-LA was present exclusively in the cytoplasm of epithelial cells of ductal and ductular types. Nuclei as well as stromal and lymphatic tissues remained unstained. While the staining was positive in all cases of intraductal carcinoma, only 4 out of 15 infiltrating carcinomas revealed SHBG-LA. The demonstration of a plasma sex steroid binding globulin in the cytoplasm of endocrine target cells is consistent with the hypothesis that steroid-binding globulins are able to enter target cells. The apparent loss of this specific cell function in infiltrating carcinomas may result from dedifferentiation and change of cell membrane properties occurring during the process of neoplastic progression.