Leuprorelin Acetate Long-Lasting Effects on GnRH Receptors of Prostate Cancer Cells: An Atomic Force Microscopy Study of Agonist/Receptor Interaction

Lama, Gina; Papi, Massimiliano; Angelucci, Cristiana; Maulucci, Giuseppe; Sica, Gigliola; Spirito, Marco De

doi:10.1371/journal.pone.0052530

Cited by 14 publications

(8 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In all the experiments, the GnRH agonist has been utilized at the dose of 10 −6 mol/L, on the basis of previous studies, from the authors’ laboratory as well as from others, aimed to investigate the molecular aspects of the antitumor activity of GnRH analogs in CRPC cells [29] , [41] – [46] . The same range of doses were also utilized to investigate the antitumor activity of GnRH agonists in several experimental models of cancer cells overexpressing the GnRH receptor [16] , [47] – [49] .…”

Section: Methodsmentioning

confidence: 99%

Gonadotropin-Releasing Hormone Agonists Sensitize, and Resensitize, Prostate Cancer Cells to Docetaxel in a p53-Dependent Manner

et al. 2014

View full text Add to dashboard Cite

Gonadotropin-releasing hormone (GnRH) receptors are expressed in prostate cancer, specifically in the most aggressive stage of the tumor (castration-resistant prostate cancer, CRPC) for which the standard treatment, docetaxel-based chemotherapy, can only improve the median survival time by few months. We previously showed that GnRH agonists exert an antitumor activity in CRPC cells; however, a link between GnRH receptors and the apoptotic machinery remains to be defined. Aim of this study was to evaluate whether, in CRPC cells, GnRH agonists might affect the expression/activity of apoptosis-related proteins and might sensitize, or resensitize, cancer cells to chemotherapeutics. We demonstrated that, in p53-positive DU145 cells, GnRH agonists: a) increase the expression of the proapoptotic protein Bax; this effect is mediated by the phosphorylation (activation) of p53, triggered by the p38 MAPK; b) potentiate the antiproliferative/proapoptotic activity of docetaxel; c) resensitize docetaxel-resistant cells to the antitumor activity of the cytotoxic drug. These data indicate that GnRH agonists sensitize and, more importantly, resensitize DU145 CRPC cells to chemotherapy in a p53-dependent manner. To confirm the crucial role of p53 in the activity of GnRH agonists, experiments were performed in p53-null PC3 cells. We found that GnRH agonists fail to increase Bax expression and do not potentiate the cytotoxic activity of docetaxel. These results may provide a rationale for novel combination treatment strategies, especially for docetaxel-resistant CRPC patients expressing a functional p53 protein.

show abstract

Section: Methodsmentioning

confidence: 99%

Gonadotropin-Releasing Hormone Agonists Sensitize, and Resensitize, Prostate Cancer Cells to Docetaxel in a p53-Dependent Manner

et al. 2014

View full text Add to dashboard Cite

show abstract

“…However, they use purified biological molecules that have been removed from their native biological context, and the results obtained cannot be directly linked to biological processes happening in vivo (Robinson et al , ). Nevertheless, it is possible to study more accurately molecular interactions and recognition as they happen in their natural environment, by performing SMFS experiments directly on living cells (Lama et al , ; Zhang et al , ).…”

Section: Introductionmentioning

confidence: 99%

Mapping HA‐tagged protein at the surface of living cells by atomic force microscopy

Formosa

Lachaize

Galès

et al. 2014

J of Molecular Recognition

View full text Add to dashboard Cite

Single-molecule force spectroscopy using atomic force microscopy (AFM) is more and more used to detect and map receptors, enzymes, adhesins, or any other molecules at the surface of living cells. To be specific, this technique requires antibodies or ligands covalently attached to the AFM tip that can specifically interact with the protein of interest. Unfortunately, specific antibodies are usually lacking (low affinity and specificity) or are expensive to produce (monoclonal antibodies). An alternative strategy is to tag the protein of interest with a peptide that can be recognized with high specificity and affinity with commercially available antibodies. In this context, we chose to work with the human influenza hemagglutinin (HA) tag (YPYDVPDYA) and labeled two proteins: covalently linked cell wall protein 12 (Ccw12) involved in cell wall remodeling in the yeast Saccharomyces cerevisiae and the β2-adrenergic receptor (β2-AR), a G protein-coupled receptor (GPCR) in higher eukaryotes. We first described the interaction between HA antibodies, immobilized on AFM tips, and HA epitopes, immobilized on epoxy glass slides. Using our system, we then investigated the distribution of Ccw12 proteins over the cell surface of the yeast S. cerevisiae. We were able to find the tagged protein on the surface of mating yeasts, at the tip of the mating projections. Finally, we could unfold multimers of β2-AR from the membrane of living transfected chinese hamster ovary cells. This result is in agreement with GPCR oligomerization in living cell membranes and opens the door to the study of the influence of GPCR ligands on the oligomerization process.

show abstract

“…The distribution of single HSPG receptors on the surface of living A549 cells was mapped by AFM, following investigation of the specific interactions between heparin-binding hemagglutinin and heparan sulphate proteoglycan receptors, 37 which provided new avenues for pathogenesis research, particularly for elucidating the molecular basis of the pathogen-host interactions. To investigate the GnRH-agonist leuprorelin acetate induced up-regulation of GnRH-R at the membrane of prostate cancer cells, Lama et al 38 mapped the amount and distribution of the functional GnRH-R receptors on the surface of living prostate cancer cells by AFM, which provided a crucial insight into the stimulatory effect of LA on GnRH-R expressed on the androgen-insensitive prostate cancer cell membrane. AFM force mapping can also be used for single ion channel imaging of the membranes of living cells.…”

Section: Afm: Probing Single Biomolecules In Cell Membranes By Functi...mentioning

confidence: 99%

In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine

Jin

Yang

et al. 2014

Nanoscale

View full text Add to dashboard Cite

The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In this review, we attempt to summarize the characteristics of these advanced techniques for use in the in situ single molecule imaging of cell membranes. We believe that this work will help to promote the technological and methodological developments of super-resolution techniques for the single molecule imaging of cell membranes and help researchers better understand which technique is most suitable for their future exploring of membrane biomolecules; ultimately promoting further developments in cell biology, immunology and medicine.

show abstract

Leuprorelin Acetate Long-Lasting Effects on GnRH Receptors of Prostate Cancer Cells: An Atomic Force Microscopy Study of Agonist/Receptor Interaction

Cited by 14 publications

References 45 publications

Gonadotropin-Releasing Hormone Agonists Sensitize, and Resensitize, Prostate Cancer Cells to Docetaxel in a p53-Dependent Manner

Gonadotropin-Releasing Hormone Agonists Sensitize, and Resensitize, Prostate Cancer Cells to Docetaxel in a p53-Dependent Manner

Mapping HA‐tagged protein at the surface of living cells by atomic force microscopy

In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine

Contact Info

Product

Resources

About