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PubMed1998

Differential screening and suppression subtractive hybridization identified genes differentially expressed in an estrogen receptor-positive breast carcinoma cell line.

Differences in gene expression are likely to explain the phenotypic differences between hormone-responsive and hormone-unresponsive breast cancer. We have identified differentially expressed cDNAs in the estrogen receptor (ER)-positive MCF7 breast carcinoma cell line compared with the ER-negative MDA-MB-231 breast carcinoma cell line. Differential screening isolated four differentially expressed genes: cytokeratin 8, cytokeratin 18, Hsp27 and GPCR -Br. To identify differentially expressed genes of lower abundance, suppression subtractive hybridization was utilized and 29 differentially expressed clones were isolated. Sequence analysis revealed that 11 clones were from previously described genes: HEK8, neuropeptide Y receptor Y1, p21 WAF-1, p55 PIK, cytokeratin 18 (cloned twice), fructose-1,6-biphosphatase, cytokeratin 8, TGFbeta1 binding protein, elongation factor 1alpha2 and pS2. The remaining 18 clones did not match sequences in the GenBank/EMBL database, indicating that they may be novel genes. Expression of pS2, neuropeptide Y receptor Y1 and three novel clones was induced by estradiol, indicating estrogen-responsiveness. The expression pattern of one novel gene, DEME -6, correlated with expression of ER and ERF -1/ AP -2gamma in a panel of breast carcinoma cell lines. A 2.6 kb cDNA of DEME -6 was sequenced and contains an open reading frame of 574 amino acids that demonstrates 62.4% similarity with a gene from Caenorhabditis elegans chromosome III. Expression of DEME -6 was also detected in primary breast carcinomas but not in normal breast tissue, as determined by RT-PCR. These findings support the hypothesis that a set of genes coordinately regulated with ER , but not necessarily estradiol-responsive, are characteristic of the hormone-responsive breast cancer phenotype.

Amino Acid Sequence↗

PubMed2002

Differential clinical efficacy of anti-CD4 monoclonal antibodies in rat adjuvant arthritis is paralleled by differential influence on NF-kappaB binding activity and TNF-alpha secretion of T cells.

The aim of this study was to analyze the differential effects of three anti-CD4 monoclonal antibodies (mAbs) (with distinct epitope specifities) in the treatment of rat adjuvant arthritis (AA) and on T-cell function and signal transduction. Rat AA was preventively treated by intraperitoneal injection of the anti-CD4 mAbs W3/25, OX35, and RIB5/2 (on days -1, 0, 3, and 6, i.e. 1 day before AA induction, on the day of induction [day 0], and thereafter). The effects on T-cell reactivity in vivo (delayed-type hypersensitivity), ex vivo (ConA-induced proliferation), and in vitro (mixed lymphocyte culture) were assessed. The in vitro effects of anti-CD4 preincubation on T-cell receptor (TCR)/CD3-induced cytokine production and signal transduction were also analyzed. While preventive treatment with OX35 and W3/25 significantly ameliorated AA from the onset, treatment with RIB5/2 even accelerated the onset of AA by approximately 2 days (day 10), and ameliorated the arthritis only in the late phase (day 27). Differential clinical effects at the onset of AA were paralleled by a differential influence of the mAbs on T-cell functions, i.e. in comparison with OX35 and W3/25, the 'accelerating' mAb RIB5/2 failed to increase the delayed-type hypersentivity (DTH) to Mycobacterium tuberculosis, increased the in vitro tumor necrosis factor (TNF)-alpha secretion, and more strongly induced NF-kappaB binding activity after anti-CD4 preincubation and subsequent TCR/CD3-stimulation. Depending on their epitope specificity, different anti-CD4 mAbs differentially influence individual proinflammatory functions of T cells. This fine regulation may explain the differential efficacy in the treatment of AA and may contribute to the understanding of such treatments in other immunopathologies.

Animals↗

PubMed2001

Profiling of differentially expressed cancer-related genes in esophageal squamous cell carcinoma (ESCC) using human cancer cDNA arrays: overexpression of oncogene MET correlates with tumor differentiation in ESCC.

PURPOSE: To examine the global gene expression of cancer-related genes in esophageal squamous cell carcinoma (ESCC) through the use of Atlas Human Cancer Array membranes printed with 588 well-characterized human genes involved in cancer and tumor biology. EXPERIMENTAL DESIGN: Two human ESCC cell lines (HKESC-1 and HKESC-2) and one morphologically normal esophageal epithelium tissue specimen from the patient of which the HKESC-2 was derived were screened in parallel using cDNA expression arrays. The array results were additionally validated using semiquantitative PCR. The overexpression of oncogene MET was studied more extensively for its protein expression by immunohistochemistry in the two ESCC cell lines and their corresponding primary tissues and 61 primary ESCC resected specimens. Sixteen of these 61 ESCC cases also had available the corresponding morphologically normal esophageal epithelium tissues and were also analyzed for MET expression. The clinicopathological features associated with overexpression of the MET gene were also correlated. RESULTS: The results of cDNA arrays showed that 13 cancer-related genes were up-regulated > or =2-fold (CDC25B, cyclin D1, PCNA, MET, Jagged 2, Integrin alpha3, Integrin alpha6, Integrin beta4, Caveolin-2, Caveolin-1, MMP13, MMP14, and BIGH3) and 5 genes were down-regulated > or =2-fold (CK4, Bad, IGFBP2, CSPCP, and IL-1RA) in both ESCC cell lines at the mRNA level. Semiquantitative RT-PCR analysis of 9 of these differentially expressed genes, including the MET gene, gave results consistent with cDNA array findings. The immunostaining results of the expression of MET gene showed that MET was overexpressed in both ESCC cell lines and their corresponding primary tumors at the protein level, validating the cDNA arrays findings. The results of the clinical specimens showed that the MET gene was overexpressed in ESCC compared with normal esophageal epithelium in 56 of 61 cases (92%). Moreover, the overexpression of MET protein was more often seen in well/moderately differentiated than in poorly differentiated ESCC. CONCLUSIONS: Multiple cancer-related genes are differentially expressed in ESCC, the oncogene MET is overexpressed in ESCC compared with normal esophageal epithelium, and its protein overexpression correlates with tumor differentiation in ESCC.

Aged↗

PubMed2005

Application of restriction fragment differential display-polymerase chain reaction in study on differential expression profiles of human diseases.

OBJECTIVE: To establish the restriction fragment differential display-polymerase chain reaction (RFDD-PCR) as an efficient technique for constructing and studying the gene expression profile of human tissues. METHODS: The tissues of mamma adenocarcinoma (T), cancerometastasis lymph node (L) and normal mammary (N) from one mammary infiltrating ductal carcinoma case were collected, and the gene expression profile of each kind of tissue was constructed using RFDD-PCR technique at equal pace according to the operating manual of Qbio-gene Company. Then all fragments of the three gene expression profiles were separated and displayed by electrophoresis. With the use of gene database at the website http://www.Qbio-gene.com/display, the authors identified the names of the probable fragments by bioinformatics analysis. Through comparison of the three profiles, the numbers and types of most differentially expressed gene fragments were displayed. RESULTS: The expression profiles of the three kinds of tissue have been constructed covering 1716 fragments of mammary adenocarcinoma, 1769 of cancerometastasis lymph nodes and 1922 of normal mammary tissue. Among these 5407 fragments, 39.39% were exactly the same. While 33.9% sequences of T and L showed differences in abundance or presence, 40.9% of T and N and 39.6% fragments of L and N were observed differentially expressed. These differentially expressed gene fragments were found to relate with metastasis, differentiation, inflammation and so on. CONCLUSION: RFDD-PCR is an efficient technique for research in human diseases genomics as a mass screening for complete gene expression profile with high-flux. Through comparison among three or more profiles, the screening for candidate genes of a certain disease can be accomplished, and there is probably a chance to identify novel gene or expressed sequence tag.

Adenocarcinoma↗

PubMedDate not supplied

Differential expression of c-myc and c-fos oncogenes during the differentiation of human leukemic cells by Ara-C.

1-B-D-arabinofuranosyl cytosine (Ara-C) is, at very low concentrations, an inducer of monocytic differentiation of human leukemic cells. By what mechanisms this differentiation is obtained and how the monocytic pathway is determined, is not yet understood. We studied the effect of Ara-C on the RNA transcript levels of two c-oncogenes often associated to cell proliferation and differentiation. In the monoblastic U-937 cell line, where Ara-C has a maximum (100%) monocytic differentiation, RNA transcript level of c-myc is not detectable, whereas c-fos levels are rapidly increased. On the other hand, in the bipotential promyelocytic HL-60 cells, Ara-C induces only 40% monocytic differentiation after 7 days; this is associated to a weaker decrement of c-myc expression; c-fos is however greatly induced 3 log after 2 days treatment, but before monocytic phenotype is observed. Ara-C, at low concentrations, may, by arresting cell proliferation, restore the leukemic's cell proliferation/differentiation equilibrium. The rapid inducement of c-fos expression may allow to foresee a rapid prescreening of Ara-C sensitive-blasts.

Cell Division↗

PubMed1983

Differential premises arising from differential socialization of the sexes: some conjectures.

The sex-differentiated socialization emphases of parents and other representatives of societal institutions are considered as they influence the personality development and behavioral orientations of males and females. Specifically, sex-differentiated socialization emphases, "shaping" behaviors, and teaching styles are evaluated with regard to the nature of the "meta-messages" conveyed to boys and girls during their early, formative years. These messages are assumed to differentially influence the self-concepts evolved, ego structures, personal goals, and the cognitive-adaptational heuristics of boys and of girls. Differences in the socialization environments experienced by the 2 sexes can be seen as related to gender differences in personality characteristics. To integrate the empirical findings surrounding gender differences in personality and socialization experience, some conjectures are offered regarding the different self- and world views our current culture may be creating and fostering in males and in females. The potential and even likely influence of biological factors conjoined with the bidirectional effects of child and parent interaction are recognized as confounded with an interpretation in terms of differential socialization. But also, it is noted that until the effects of differential socialization are specifically evaluated by cultural, subcultural, or individual family changes, the role of biological and bidirectional factors cannot be assessed.

Achievement↗

PubMedDate not supplied

Cytology of well-differentiated and poorly differentiated hemangiosarcoma in fine needle aspirates.

The cytologic descriptions of fine needle aspirates from one well-differentiated and one poorly differentiated hemangiosarcoma are reported and correlated with the histologic findings. Aggregates of two to ten cells predominated in the aspirate from the well-differentiated tumor. In Papanicolaou-stained smears and filter preparations, single nuclei, resembling intravascular nuclear protrusions in a punch biopsy specimen, projected from some of these cell groups. Shallow longitudinal invaginations characterized the hyperchromatic nuclei. Erythrophagocytosis and cytoplasmic vacuoles were evident in Wright's-stained smears. Individual binucleate cells predominated in aspirates from the poorly differentiated tumor. Their nuclei exhibited thicker membranes, more prominent nucleoli and clearer parachromatin than did those of cells from the well-differentiated tumor. Cytoplasmic projections were common and sometimes quite complex. While these cytologic features are not pathognomonic, they are indicative of a malignant neoplasm and can be combined with clinical and other histopathologic data to provide a complete diagnosis.

Adult↗

PubMed1995

Use of differential display to identify differentially expressed mRNAs induced by rat carotid artery balloon angioplasty.

BACKGROUND: We have used differential display technology in an animal model of arterial restenosis to study the molecular mechanisms of neointima formation. EXPERIMENTAL DESIGN: Balloon angioplasty of the rat common carotid artery was performed, and tissues were examined from naive animals (control) and from animals that had undergone angioplasty 6 hours, 3 days, and 14 days earlier. Total RNA was isolated, and differential display was performed to identify mRNA transcripts whose expression is modulated in a temporal fashion as a consequence of balloon angioplasty. RESULTS: Using total RNA isolated from vessels excised from naive rats and those from rats that underwent angioplasty up to 14 days earlier, we describe two differentially regulated transcripts by differential display and verify the expression pattern of these same transcripts by Northern analysis. DNA sequence analysis has identified one of these angioplasty-induced transcripts as a novel sequence and the other as the tryptophan hydroxylase and protein kinase C regulatory protein 14-3-3 gamma. CONCLUSIONS: In this study, we describe the in vivo application of the differential display technique in a rat carotid artery angioplasty model to identify mRNA transcripts whose expression is modulated selectively in vessels undergoing neointima formation. Use of this technique in animal models of disease should facilitate our understanding of gene expression patterns in pathogenesis and may serve as a reliable technique to "fingerprint" disease processes.

14-3-3 Proteins↗

PubMed1995

Identification of melanoma inhibitory activity and other differentially expressed messenger RNAs in human melanoma cell lines with different metastatic capacity by messenger RNA differential display.

The differential display technique was used to identify mRNAs differentially expressed in human melanoma cell lines with different metastatic capacity. We report the isolation of nine different clones, of which four were uniquely expressed in the highly metastatic human melanoma cell line MV3, whereas the other five clones were uniquely expressed in the poorly metastatic human melanoma cell line 530. The differences in expression identified by differential mRNA display were confirmed by Northern blot analyses. DNA sequencing followed by computer search analyses indicated that of the nine differentially expressed clones, five represented novel gene products. The other four were histocompatibility antigen HLA-DR, laminin B2, melanoma inhibitory activity (MIA), and tissue inhibitor of metalloproteinases 3. MIA was also identified in RNA from human melanoma metastasis lesions in a comparison by differential display with pooled human nevi. Northern blot analysis confirmed MIA mRNA expression in nonmetastasizing melanoma cell lines and in melanoma metastasis lesions, while expression was absent in highly metastasizing cell lines and pretumor stages. In the 11 metastasis lesions examined, MIA mRNA expression was apparently inversely correlated with pigmentation.

Amino Acid Sequence↗

PubMed1995

Human circulating specific antibody-forming cells after systemic and mucosal immunizations: differential homing commitments and cell surface differentiation markers.

Circulating spontaneous antibody-secreting cells (ASC) induced by mucosal and systemic immunizations in human volunteers have been characterized with respect to differentiation stage and homing commitments. Irrespective of the immunization route, the large majority of ASC co-expressed CD19 and HLA-DR, which are normally lost during the transition of plasmablasts to plasmocytes, as well as CD38, a marker of activated B cell blasts, expressed also by plasmocytes. However, these cells expressed neither CD28, a molecule acquired by plasmocytes, nor CD22 and CD37, which are lost during the transition of plasmablasts to plasmocytes. Therefore, the large majority of ASC found in peripheral blood after oral and parenteral immunizations are terminally differentiated B cells, but not fully differentiated plasmocytes. As a whole, the mucosally derived ASC population seemed to be more homogenously differentiated. CD25 was detected on few ASC, whereas ASC expressing CD71 were more numerous, especially among systemically derived ASC. Almost all ASC expressed the adhesion molecules CD44 and alpha 4-integrins, irrespective of immunization route. However, virtually all systemically derived ASC expressed L-selectin, recognizing the peripheral lymph node addressin, whereas only a minority of mucosally induced blood ASC expressed L-selectin. These studies are the first to demonstrate in humans that circulating precursors of mucosal B cell immunoblasts utilize organ-specific recognition mechanisms distinct from those of corresponding systemic B cells and appear to be more advanced in the B lineage maturation pathway. Specialization of receptor expression could explain both the unification of immune responses in diverse mucosal sites and the physiologic segregation of mucosal from non-mucosal immune mechanisms in humans.

Adult↗

PubMed1995

Expression of leukocyte differentiation antigens during the differentiation of HL-60 cells induced by 1,25-dihydroxyvitamin D3: comparison with the maturation of normal monocytic and granulocytic bone marrow cells.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] induces monocytic differentiation of the HL-60 leukemic cell line. The present study investigated whether and to what extent this differentiation resembles the normal maturation of monocytic cells in the bone marrow. Multidimensional flow cytometry was used to identify changes in antigen expression that occur in normal bone marrow cells at distinct stages of monocytic and granulocytic maturation. HL-60 cells were analyzed in the same manner after exposure to 1,25-(OH)2D3 to determine whether the hormone induces a similar sequence of phenotypic changes. In the leukemic cells, monocytic features were sequentially induced and several maturational steps could be resolved. CD14, CD32, CD53, CD15, CDw65, CD29, CD16, and CD66b were modulated in 1,25-(OH)2D3-induced HL-60 cells as in the normal monocytic maturational pathway. Differences were observed for CD15s and CDw17. The expression pattern of CD44 during differentiation of HL-60 cells resembled that in granulocytic cells. The results therefore suggest that 1,25-(OH)2D3 induces a differentiation program in HL-60 cells that in many ways resembles that of normal monocytic cells in the bone marrow but also carries elements of the granulocytic pathway.

Antibodies, Monoclonal↗

PubMed2026

Comprehensive analysis of differentially expressed mRNAs, lncRNAs, and miRNAs involved in ovarian differentiation and development in Qihe gibel carp (Carassius gibelio var. Qihe).

Qihe gibel carp (Carassius gibelio var. Qihe) exhibits diverse reproductive modes including gynogenesis and sexual reproduction, yet the molecular mechanisms of ovarian differentiation remain poorly understood. Ovarian tissues at 20, 30, and 60 days after hatching (dah), representing key stages covering early ovarian differentiation and primary oocyte growth, were subjected to whole-transcriptome sequencing. A total of 27,259 mRNAs, 2622 lncRNAs, and 2467 miRNAs were differentially expressed. Cell cycle, transcription, translation, and DNA replication pathways were significantly upregulated from 20 to 60 dah. Oocyte meiosis was enriched from 20 and 30 dah, whereas metabolic pathways (lipid, carbohydrate, and nucleotide metabolism) were enriched from 30 to 60 dah, indicating sequential progression from meiosis initiation to primary oocyte growth with nutrient synthesis. Hub lncRNAs and key ceRNA networks (e.g., MSTRG.28669.5-miR-221-ccnb2) were identified. This study provides the first comprehensive characterization of ncRNA-mediated regulation and ceRNA networks during ovarian development in Qihe gibel carp, establishing a foundation for understanding ovarian differentiation in this species.

Animals↗

PubMed2001

Differential gene expression during capillary morphogenesis in 3D collagen matrices: regulated expression of genes involved in basement membrane matrix assembly, cell cycle progression, cellular differentiation and G-protein signaling.

We have performed a screening analysis of differential gene expression using a defined in vitro model of human capillary tube formation. Gene array, differential display and cDNA library screening were used to identify both known and novel differentially expressed genes. Major findings include: the upregulation and functional importance of genes associated with basement membrane matrix assembly; the upregulation of growth factors, transcription factors, anti-apoptotic factors, markers of endothelial cell differentiation, JAK-STAT signalling molecules, adhesion receptors, proteinase inhibitors and actin regulatory proteins; and expression changes consistent with inhibition of cell cycle progression, increased cholesterol biosynthesis, decreased ubiquitin-proteasome mediated degradation, and activation of G-protein signaling pathways. Using DNA microarray analysis, the most induced genes at 8, 24 and 48 hours compared with those at 0 hours were jagged-1, stanniocalcin and angiopoietin-2, whereas the most repressed genes were connective tissue growth factor, fibulin-3 and RGS-5. In addition, the full length coding sequence of two novel regulated capillary morphogenesis genes (CMGs) are presented. CMG-1 encodes a predicted intracellular 65 kDa protein with coiled-coil domains. A CMG-1-green fluorescent protein (GFP) chimera was observed to target to an intracellular vesicular compartment. A second novel gene, CMG-2, was found to encode a predicted intracellular protein of 45 kDa containing a transmembrane segment and a CMG-2-GFP chimera was observed to target to the endoplasmic reticulum. A recombinant portion of CMG-2 was found to bind collagen type IV and laminin, suggesting a potential role in basement membrane matrix synthesis and assembly. These data further elucidate the genetic events regulating capillary tube formation in a 3D matrix environment.

Amino Acid Sequence↗

PubMed1989

Differential expression of CD11b/CD18 (Mo1) and myeloperoxidase genes during myeloid differentiation.

During the course of differentiation of early human myeloid cells toward monocytes and granulocytes, cell surface expression of the cell adhesion molecule, CD11b/CD18 (Mo1) increases dramatically and expression of myeloperoxidase (MPO), a bacteriocidal enzyme, decreases markedly. Using the inducible promyelocytic cell line HL-60 as a model, we studied the mRNA expression of these genes. Differentiation of these cells along both a monocytic and a granulocytic pathway demonstrated that the mRNA levels of the two subunits of CD11b/CD18 increased in a pattern temporally and quantitatively similar to the increase in cell surface expression of this heterodimer. In contrast, the expression of MPO mRNA decreased in a temporal and quantitative pattern similar to the known decrease in MPO protein during differentiation, suggesting that regulation of these myeloid-specific proteins may occur at the level of mRNA expression. These findings have important implications with regard to the nature of the block in differentiation in acute nonlymphocytic leukemia and the regulation of myeloid gene expression.

Antigens, Differentiation↗

PubMed1996

Three forms of RPTP-beta are differentially expressed during gliogenesis in the developing rat brain and during glial cell differentiation in culture.

In situ hybridization and Northern analysis demonstrate that the three splicing variants of RPTP-beta have different spatial and temporal patterns of expression in the developing brain. The 9.5-kb and 6.4-kb transcripts, which encode transmembrane protein tyrosine phosphatases with different extracellular domains, are predominantly expressed in glial progenitors located in the subventricular zone (SVZ). The 8.4-kb transcript, which encodes a secreted chondroitin sulfate proteoglycan (phosphacan), is expressed at high levels by more mature glia that have migrated out of the SVZ. The three transcripts are also differentially expressed in glial cell cultures; O2A progenitors express high levels of the 9.5- and 8.4-kb transcript, whereas type 1 astrocyte progenitors predominantly express the 6.4-kb transcript. C6 gliomas also express high levels of the 6.4-kb transcript. Treating C6 cells with the differentiating agent dibutyryl cyclic-AMP (DBcAMP), induces a decrease in the 6.4-kb transcript and a corresponding increase in the 8.4-kb transcript. O2A cells grown in the presence of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) remain highly proliferative and undifferentiated, and continue to express high levels of RPTP-beta. However, when O2A cells are grown in conditions that induce oligodendrocyte differentiation, there is a marked decrease in the expression of the transmembrane forms of RPTP-beta, as determined by immunofluorescence. These results demonstrate that RPTP-beta expression is regulated during glial cell differentiation and suggest that the different forms of RPTP-beta perform distinct functions during brain development.

Animals↗

PubMed2000

Balance of two secretion pathways of nerve growth factor in PC12 cells changes during the progression of their differentiation, with a decrease in constitutive secretion in more differentiated cells.

Proteins are secreted from animal cells by either a constitutive or a regulated pathway. When cDNA of nerve growth factor (NGF) was introduced into PC12 cells, these cells produced and secreted active NGF, where NGF was secreted not only in constitutive but also in activity-dependent regulated way according to the results of pulse-chase and ELISA studies. The regulated secretion was caused by depolarization, cyclic AMP analogue, or beta-adrenergic agonist but not by glutamate or carbachol. Because these transfected cells differentiated into a morphology indistinguishable from that incubated with NGF protein, we next compared the secretion pathways of NGF from PC12 cells at different stages of the differentiation. NGF was secreted in both constitutive and regulated way at 2 and 7 days after the transfection of NGF-cDNA, but the constitutive secretion of NGF from the more differentiated cells of Day 7 was decreased and mature NGF tended to accumulate in the cells. These results indicate that the neurotrophin secretion mechanism is intimately regulated in the course of the differentiation of PC12 cells. Such a change in the protein secretion pathway might have an profound role in the development of neurons.

Animals↗

PubMed1999

A repertoire of differentially expressed transcription factors that offers insight into mechanisms of human cytotrophoblast differentiation.

During human placental development, specialized cells allocated to the extraembryonic lineage (cytotrophoblasts) invade the uterus, anchoring the conceptus to the decidua and tapping a supply of maternal blood. This unusual behavior requires cytotrophoblasts to assume highly specialized characteristics; some are commonly associated with tumor cells, while others are typical of endothelia. Here we investigated the transcriptional mechanisms that control cytotrophoblast differentiation/invasion. Specifically, we examined the cells' expression of a number of transcription factors, at the RNA level, as they differentiated along the invasive pathway in vitro. Since basic helix-loop-helix (bHLH) proteins play important roles in murine trophoblast differentiation, we first examined their expression by cytotrophoblasts. As in murine placental development, expression of the human homologue of Mash-2 was confined to progenitor cells. But expression of Hand-1, which promotes differentiation of murine trophoblast giant cells, was not detected. We also found that cytotrophoblasts upregulated the expression of bHLH/PAS factors that function in adaptive responses to hypoxia, including hEPAS-1, which is expressed primarily in endothelial cells. Quite unexpectedly, we discovered that cytotrophoblasts express high levels of mRNA encoding the human homologue of the Drosophila neuronal fate gene, glial cells missing-1 (gcm-1). We also found evidence of crosstalk between the bHLH and GCM-1 regulatory networks. Together, these results offer insights into the transcriptional mechanisms that govern cytotrophoblast differentiation/invasion. Interestingly, these mechanisms suggest analogies with those that govern differentiation of murine stem cells allocated to both the intra- and extraembryonic lineages.

Animals↗

PubMed1992

Differential sorting of beta tubulin isotypes into colchicine-stable microtubules during neuronal and muscle differentiation of embryonal carcinoma cells.

Pluripotent P19 embryonal carcinoma (EC) cells were differentiated along the neuronal and muscle pathways. Comparisons of class I, II, III, and IV beta tubulin isotypes in total and colchicine-stable microtubule (MT) arrays from uncommitted EC, neuronal, and muscle cells were made by immunoblotting and by indirect immunofluorescence microscopy. In undifferentiated EC cells the relative amounts of these four isotypes are the same in both the total and stable MT populations. Subcellular sorting of beta tubulin isotypes was demonstrated in both neuronal and muscle differentiated cells. During neuronal differentiation, class II beta tubulin is preferentially incorporated into the colchicine-stable MTs while class III beta tubulin is preferentially found in the colchicine-labile MTs. The subcellular sorting of class II into stable MTs correlates with the increased staining of MAP 1B, and with the expression of MAP 2C and tau. Although muscle differentiated cells express class II beta tubulin, stable MTs in these cells do not preferentially incorporate this isotype but instead show increased incorporation of class IV beta tubulin. Muscle cells do not show high levels of MAP 1B and do not express MAP 2C or tau. These results are consistent with the hypothesis that a subcellular sorting of tubulin isotypes is the result of a complex interaction between tubulin isotypes and MT-associated proteins.

Animals↗