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H Hondermarck

Publications and source records attributed to H Hondermarck.

At least 19 recordsLinked to original sources
PubMed2006

[Proteomics and breast cancer: new perspectives and limitations].

From differential analysis for the identification of biomarkers, to functional analysis for the evidencing of new therapeutic targets, proteomics brings new comprehensive information for a better understanding of the molecular basis of oncology and new perspectives for the clinic. However the major limitation of proteomic investigations and more generally of post-genomic approaches remains the molecular and cellular complexity of biological systems. This will be illustrated with the case of breast cancer.

Antineoplastic Agents↗
PubMed2004

Synergistic induction of apoptosis in breast cancer cells by cotreatment with butyrate and TNF-alpha, TRAIL, or anti-Fas agonist antibody involves enhancement of death receptors' signaling and requires P21(waf1).

Inhibitors of histone deacetylase (HDAC) are considered as potential anticancer agents. We have previously demonstrated that an inhibitor of HDAC, sodium butyrate (NaB), induces apoptosis of breast cancer cells in a P53-independent and P21(waf1)-dependent manner. In this study, we showed that tumor necrosis factor-alpha (TNF-alpha), TNF-related apoptosis-inducing ligand (TRAIL), and anti-Fas agonist antibody potentiated NaB-induced growth inhibition through synergistic induction of apoptosis in breast cancer cell lines (MCF-7, T47-D, and BT-20). In MCF-7 cells, NaB increased the expression of death receptors; NaB alone or in combination with TNF-alpha, TRAIL, and anti-Fas agonist antibody increased the levels of Bid, tBid, and that of cytosolic cytochrome c. Synergistic induction of apoptosis was strongly inhibited by dominant-negative Fas-associated death domain (FADD) and inhibitors of caspases-8 and -9, indicating that potentiation of apoptosis involved key elements of death receptors' signaling pathways. Moreover, cotreatment of NaB and ligands of death receptors up-regulated the levels of P21(waf1) and that of proliferating cell nuclear antigen (PCNA) associated with P21(waf1). Transient transfections of p21(waf1) antisense or p21(waf1) deficient for its interaction with PCNA abolished synergistic induction of apoptosis. This suggested that potentiation of apoptosis by cotreatments required P21(waf1) and its interaction with PCNA. Since breast tumors contain rarely p21 mutations, our results may open interesting prospects in the fight against breast cancer.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Expression of nerve growth factor receptors and their prognostic value in human breast cancer.

Nerve growth factor (NGF) has been shown recently to be mitogenic for human breast cancer cells. In the present study, we have assayed the expression of NGF receptors (NGFRs: TrkA and p75) mRNAs in 363 human primary breast cancers, using real-time quantitative reverse transcription-PCR. NGFRs were found in all of the tumor biopsies. TrkA and p75 were positively correlated and were respectively associated with the histoprognostic grading and the tumor type. NGFRs were both related to progesterone receptors. In univariate analyses, TrkA (>upper quartile) was associated with longer overall survival. Histoprognostic grading, tumor size, node involvement, and steroid receptors were also prognostic factors. In Cox multivariate analyses, TrkA was not a prognostic parameter. This study demonstrates the expression of NGFRs in breast cancer and points out that patients with high levels of TrkA have a more favorable overall survival prognosis.

Adult↗
PubMed2001

Nerve growth factor stimulates proliferation and survival of human breast cancer cells through two distinct signaling pathways.

We show here that the neurotrophin nerve growth factor (NGF), which has been shown to be a mitogen for breast cancer cells, also stimulates cell survival through a distinct signaling pathway. Breast cancer cell lines (MCF-7, T47-D, BT-20, and MDA-MB-231) were found to express both types of NGF receptors: p140(trkA) and p75(NTR). The two other tyrosine kinase receptors for neurotrophins, TrkB and TrkC, were not expressed. The mitogenic effect of NGF on breast cancer cells required the tyrosine kinase activity of p140(trkA) as well as the mitogen-activated protein kinase (MAPK) cascade, but was independent of p75(NTR). In contrast, the anti-apoptotic effect of NGF (studied using the ceramide analogue C2) required p75(NTR) as well as the activation of the transcription factor NF-kB, but neither p140(trkA) nor MAPK was necessary. Other neurotrophins (BDNF, NT-3, NT-4/5) also induced cell survival, although not proliferation, emphasizing the importance of p75(NTR) in NGF-mediated survival. Both the pharmacological NF-kappaB inhibitor SN50, and cell transfection with IkBm, resulted in a diminution of NGF anti-apoptotic effect. These data show that two distinct signaling pathways are required for NGF activity and confirm the roles played by p75(NTR) and NF-kappaB in the activation of the survival pathway in breast cancer cells.

Breast Neoplasms↗
PubMed2001

Proteomic detection of changes in protein synthesis induced by fibroblast growth factor-2 in MCF-7 human breast cancer cells.

Fibroblast growth factor-2 (FGF-2) is a potent regulator of breast cancer cell growth through stimulation of tyrosine kinase receptors and activation of the mitogen-activated protein kinase cascade. In the present study, we have investigated changes in protein synthesis induced by FGF-2 stimulation of the prototypic human breast cancer cell line MCF-7. Using high-resolution two-dimensional electrophoresis of (35)S amino acid metabolically labeled proteins and computerized analysis of 2D autoradiograms, we found that four proteins were up-regulated within the first 12 h of FGF-2 stimulation. Mass spectrometry analysis (MALDI-TOF and MS-MS) of tryptic fragments and database searches allowed the identification of these FGF-2-regulated proteins as the heat shock proteins HSP90 and HSP70, the proliferating cell nuclear antigen (PCNA), and the transcriptionaly controlled tumor protein (TCTP). We then analyzed the distribution of these proteins in various cancerous and normal breast epithelial cells. Interestingly, the four FGF-2-regulated proteins were found to be constitutively up-regulated in ras-transfected MCF-7 cells, indicating their relevance to the up-regulation of cellular proliferation. Moreover, HSP90 and PCNA were found at higher levels in cancerous cells than in normal cells. The role of HSP90 was further investigated using the specific inhibitor geldanamycin. We showed that the functionality of HSP90 is strictly required in order to obtain FGF-2 mitogenic stimulation in MCF-7 cells, indicating the crucial role played by this molecular chaperone in the control of breast cancer cell growth. Finally, these results show that proteomic analysis is a valuable method for identifying potential markers or therapeutic targets related to cancer growth.

Biomarkers, Tumor↗
PubMed2001

Proteomic analysis reveals that 14-3-3sigma is down-regulated in human breast cancer cells.

The class of molecular chaperones known as 14-3-3 is involved in the control of cellular growth by virtue of its apparent regulation of various signaling pathways, including the Raf/mitogen-activated protein kinase pathway. In breast cancer cells, the sigma form of 14-3-3 has been shown to interact with cyclin-dependent kinases and to control the rate of entry into mitosis. To test for a direct role for 14-3-3 in breast epithelial cell neoplasia, we have quantitated 14-3-3 protein levels using a proteomic approach based on two-dimensional electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF). We show here that 14-3-3sigma protein is strongly down-regulated in the prototypic breast cancer cell lines MCF-7 and MDA-MB-231 and in primary breast carcinomas as compared with normal breast epithelial cells. In contrast, levels of the alpha, beta, delta, or zeta isoforms of 14-3-3 were the same in both normal and transformed cells. The data support the idea that 14-3-3sigma is involved in the neoplastic transition of breast epithelial cells by virtue of its role as a tumor suppressor; as such, it may constitute a robust marker with clinical efficacy for this pathology.

14-3-3 Proteins↗
PubMed2001

Proteomics of breast cancer for marker discovery and signal pathway profiling.

Breast cancer is the most common form of cancer among women and the identification of markers to discriminate tumorigenic from normal cells, as well as the different stages of this pathology, is of critical importance. Two-dimensional electrophoresis has been used before for studying breast cancer, but the progressive completion of human genomic sequencing and the introduction of mass spectrometry, combined with advanced bioinformatics for protein identification, have considerably increased the possibilities for characterizing new markers and therapeutic targets. Breast cancer proteomics has already identified markers of potential clinical interest (such as the molecular chaperone 14-3-3 sigma) and technological innovations such as large scale and high throughput analysis are now driving the field. Methods in functional proteomics have also been developed to study the intracellular signaling pathways that underlie the development of breast cancer. As illustrated with fibroblast growth factor-2, a mitogen and motogen factor for breast cancer cells, proteomics is a powerful approach to identify signaling proteins and to decipher the complex signaling circuitry involved in tumor growth. Together with genomics, proteomics is well on the way to molecularly characterizing the different types of breast tumor, and thus defining new therapeutic targets for future treatment.

14-3-3 Proteins↗
PubMed2001

[Proteomic analysis: why and how ?].

The proteome, first formalized in 1995, designs all the proteins expressed by the genome of a cell, tissu, or organ at a defined time. Proteomic analysis leads to a description of the regulation of gene expression by the study of proteins and of their post-translational modifications. Proteomic analysis is based on three technologies: 1) Two-dimensional electrophoresis allowing the separation of thousands of proteins from a single mixture; 2) mass spectrometry allowing the characterization of picoquantities of polypeptides and providing data on post-translational modifications; 3) Bioinformatic which is required for the quantification of protein level and for the constitution of databases of protein expression profiles. Complementing the methods of the genomics, the use of proteomic analysis is widely spreading in the fields of fundamental biology, biomedicine and pharmacology for the identification of new biological markers and therapeutic targets.

Animals↗
PubMed2000

The proliferative and migratory activities of breast cancer cells can be differentially regulated by heparan sulfates.

To explore how heparan sulfate (HS) controls the responsiveness of the breast cancer cell lines MCF-7 and MDA-MB-231 to fibroblast growth factors (FGFs), we have exposed them to HS preparations known to have specificity for FGF-1 (HS glycosaminoglycan (HSGAG A)) or FGF-2 (HSGAGB). Proliferation assays confirmed that MCF-7 cells were highly responsive to FGF-2 complexed with GAGB, whereas migration assays indicated that FGF-1/HSGAGA combinations were stimulatory for the highly invasive MDA-MB-231 cells. Quantitative polymerase chain reaction for the levels of FGF receptor (FGFR) isoforms revealed that MCF-7 cells have greater levels of FGFR1 and that MDA-MB-231 cells have greater relative levels of FGFR2. Cross-linking demonstrated that FGF-2/HSGAGB primarily activated FGFR1, which in turn up-regulated the activity of mitogen-activated protein kinase; in contrast, FGF-1/HSGAGA led to the phosphorylation of equal proportions of both FGFR1 and FGFR2, which in turn led to the up-regulation of Src and p125(FAK). MDA-MB-231 cells were particularly responsive to vitronectin substrates in the presence of FGF-1/HSGAGA, and blocking antibodies established that they used the alpha(v)beta(3) integrin to bind to it. These results suggest that the clustering of particular FGFR configurations on breast cancer cells induced by different HS chains leads to distinct phenotypic behaviors.

Breast Neoplasms↗
PubMed2000

The mitogenic signaling pathway for fibroblast growth factor-2 involves the tyrosine phosphorylation of cyclin D2 in MCF-7 human breast cancer cells.

Fibroblast growth factor-2 (FGF-2) is mitogenic for the human breast cancer cell line MCF-7; here we investigate some of the signaling pathways subserving this activity. FGF-2 stimulation of MCF-7 cells resulted in a global increase of intracellular tyrosine phosphorylation of proteins, particularly FGF receptor substrate-2, the protooncogene product Src and the mitogen-activated protein kinase (MAP kinase) cascade. A major increase in the tyrosine phosphorylation of a 30-kDa protein species was also found. This protein was identified as cyclin D2 by mass spectrometry after trypsin digestion. Immunoprecipitation of cyclin D2 and immunoblotting with anti-phosphotyrosine antibodies confirmed that the tyrosine phosphorylation of cyclin D2 was indeed induced by FGF-2 stimulation. In addition, pharmacological inhibition of Src (with herbimycin A and PP2), and of the MAP kinase cascade (with PD98059), confirmed that Src activity is required for the FGF-2-induced phosphorylation of cyclin D2 whereas MAP kinase activity is not. Thus, tyrosine phosphorylation of cyclin D2 may be a key regulatory target for FGF-2 signaling.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Differential regulation of FGF-1 and -2 mitogenic activity is related to their kinetics of binding to heparan sulfate in MDA-MB-231 human breast cancer cells.

The growth of the malignant human mammary MDA-MB-231 cells is stimulated by fibroblast growth factor-1 (FGF-1) but not by FGF-2. When these cells are cultured in the presence of chlorate, an inhibitor of heparan sulfate (HS) sulfation, their proliferation is stimulated by both FGF-1 and FGF-2. We analyzed the interactions of FGF-1 and FGF-2 with HS purified from the cell layer and the culture medium of control and chlorate-treated MDA-MB-231 cells. The HS from the cell layer bound FGF-1 with faster association kinetics than the HS from the culture medium, and so had a higher affinity for FGF-1. Chlorate treatment had no significant effect on the FGF-1 binding kinetics of the HS. In contrast to FGF-1, chlorate treatment of the cells significantly altered the FGF-2 binding kinetics. The HS from untreated cells possessed two binding sites for FGF-2, one with fast association kinetics (k(ass) 470,000 to 610,000 M(-1) s(-1)) and a high affinity (K(d) 46 to 70 nM) and one with slower association kinetics (k(ass) 74,000 to 100,000 M(-1) s(-1)) and a lower affinity (K(d) 290 to 400 nM). HS from chlorate-treated cells possessed just a single binding site for FGF-2 with fast association kinetics (k(ass) 270,000 to 290,000 M(-1) s(-1)) and a high affinity (K(d) 41 to 57 nM). These results show that there is a relationship between the binding kinetics of FGFs and their ability to stimulate cell growth.

Artifacts↗
PubMed2000

Regulation of sialyltransferase expression by estradiol and 4-OH-tamoxifen in the human breast cancer cell MCF-7.

We have addressed the effects of estradiol and 4-OH-tamoxifen on the expression of five sialyltransferases in the hormono-dependent MCF-7 cell line using a Multiplex RT-PCR approach. Estradiol induced a statistically significant increase in ST3Gal III and a decrease in ST6Gal I, whereas the two other enzymes, ST3Gal IV and ST3Gal I, are not modified and expression of the fifth enzyme, ST3Gal II, was very low or not detectable. Estradiol effects were dose dependent and completely antagonized by 4OH-tamoxifen. In addition, there is no direct relation between cellular proliferation and sialyltransferase expression. This suggests that ST3Gal III and ST6Gal I could be used as supplementary markers of hormono-sensitivity in breast cancer.

Antineoplastic Agents, Hormonal↗
PubMed2000

Normal breast epithelial cells induce apoptosis of MCF-7 breast cancer cells through a p53-mediated pathway.

Cancer development depends not only on the nature of the tumor cells themselves but also on the regulatory effects of various normal cells. The present study was performed to better understand the mechanism by which normal breast epithelial cells (NBEC) can control the growth of MCF-7 breast cancer cells. When MCF-7 cells were treated with NBEC conditioned medium, cell growth was inhibited in a concentration-dependent manner. This inhibition was due to an induction of apoptosis without any change in cell cycle progression. The induction of apoptosis was correlated with increased levels of p53, p21(waf1) and decreased levels of bcl-2. Transient transfections of MCF-7 cells with two p53 cDNA constructs demonstrated the induction of apoptosis was mediated by endogenous p53. Taken together, our results indicate that NBEC inhibit the growth of MCF-7 breast cancer cells by inducing apoptosis in them via endogenous p53.

Adult↗
PubMed2000

FGF signals for cell proliferation and migration through different pathways.

FGFs are pleiotropic growth factors that control cell proliferation, migration and differentiation. However, FGF transduction studies have so far focused primarily on the mitogenic effect of this growth factor family and it has been difficult to assess if the described intracellular signaling pathways are dedicated solely to cell proliferation, or whether they are equally important for the migratory activity often seen in responsive cells. We review here papers in which the migratory effects of this growth factor family were clearly discriminated from proliferative effects. In toto, these studies suggest that cells use different signaling pathways for migration, such as Src and p38 MAP kinase, from those for proliferation, which tend to upregulate the ERKs. Which signaling pathway a cell uses for proliferation or migration appears to depend on many factors, including the structure and the quantity of available FGF trapped in the basal lamina by heparan sulfate co-factors, the disposition of cognate high affinity receptors and the general environment of the cell. Thus the density of the cell population, the state of the cell cycle, the presence of other factors or receptors will modulate the migratory response of cells to FGF.

Animals↗
PubMed2000

Autocrine and paracrine growth inhibitors of breast cancer cells.

Breast epithelial cells produce both mitogens and growth inhibitors which are involved in the control of mammary gland development through autocrine and paracrine pathways. While the mechanisms of action of several growth factors have been well established and related strategies proposed for breast cancer therapy, little is known concerning growth inhibitors. In this review, we present an overview of current information about major autocrine and paracrine growth inhibitors of breast epithelial cells, and we discuss their potential functions in the control of breast cancer development.

Autocrine Communication↗
PubMed1998

Alterations in both heparan sulfate proteoglycans and mitogenic activity of fibroblast growth factor-2 are triggered by inhibitors of proliferation in normal and breast cancer epithelial cells.

Heparan sulfate proteoglycans (HSPG) are involved in the regulation of cellular proliferation, differentiation, and migration. We have studied the effect of three inhibitors of proliferation on 35S incorporation into HSPG of the breast cancer cell lines MCF-7 and MDA-MB-231 and the normal breast epithelial cells (NBEC). Transforming growth factor beta-1 (TGFbeta-1), which inhibits the proliferation of NBEC, but not of MCF-7 and MDA-MB-231, cells induced an increase in 35S incorporation of HSPG in NBEC, but had no effect on cancer cells. Sodium butyrate (NaB), which inhibits NBEC as well as cancer cell proliferation, induced an increase in 35S incorporation into HSPG in all cell types studied. In contrast, retinoic acid had no effect on HSPG of breast epithelial cells. Modification of HSPG induced by TGFbeta-1 or NaB treatments in normal and breast cancer epithelial cells resulted in an increase in 125I-fibroblast growth factor-2 (FGF-2) binding on HSPG. More importantly, NaB pretreatment resulted in an inhibition of the MCF-7 cell responsiveness to FGF-2, even though these cells remained sensitive to growth stimulation induced by serum or epidermal growth factor. These results indicate that changes in HSPG production are a key process involved in the mechanism of breast epithelial cell growth regulation.

Binding Sites↗
PubMed1998

Nerve growth factor is mitogenic for cancerous but not normal human breast epithelial cells.

We show here that nerve growth factor (NGF), the archetypal neurotrophic factor, is able to stimulate the proliferation of breast cancer cells (MCF-7 and MDA-MB-231 cell lines), although it is unable to stimulate growth of normal breast epithelial cells (NBEC). This stimulation induced cells in the G0 phase to reenter the cell cycle, as well as shortening cell cycle duration. Immunoblotting experiments revealed that both the two cancer cell lines and the NBEC express high affinity (p140(trk)) and low affinity (p75) NGF receptors. Inhibition of the NGF growth-promoting effect by the drugs K-252a and PD98059 indicated that activation of Trk-tyrosine kinase activity and the mitogen-activated protein kinase cascade are necessary to obtain the mitogenic effect. Activation of mitogen-activated protein kinase can be detected in breast cancer cells after 10 min of NGF stimulation, whereas no change was detected in NBEC. These results demonstrate that NGF is a mitogenic factor for human breast cancer cells and that it might constitute a new regulator of breast tumor growth.

Blotting, Western↗