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For many years, scientists and suppliers have refered to AMV-RT as the reverse transcriptase produced by the Avian Myelobalstosis Virus. This manuscript briefly reviews the molecular basis for biological dependence of AMV for the envelope and RT proteins that are produced by its natural helper the Myeloblastosis Associated Virus (MAV). Because the wide use of the term «AMV RT» obscures scientific facts, it is worthwhile to clarify this issue for the scientific community, especially for younger scientists who might not be aware of the functional relationships that exist between these two viruses. [ABSTRACT FROM AUTHOR]

The identification of potential partners for CCN3(NOV) sheds new light on the biological activity of this signaling protein. In particular, the physical interaction of CCN3 with the IL33 cytokine combined with previous data indicating that CCN3 expression was regulated by TNFalpha and IL1 cytokines, point to CCN3 as a potent player in a variety of inflammatory responses, including neurodegenerative disease, and arthritis. Nuclear proteins that are involved in the regulation of RNA processing and chromatin remodeling were also found to interact with CCN3. These observations reinforce the concept that routing of CCN3 to the cell nucleus where it acts as a transcription regulator, might constitute a key element in the balance between the anti- and proproliferative activities of CCN3 proteins. [ABSTRACT FROM AUTHOR]

The principal aim of this historical review- the first in a new series- is to present the basic concepts that led to the discovery of NOV and to show how our ideas evolved regarding the role and functions of this new class of proteins. It should prove particularly useful to the new comers and to students who are engaged in this exciting field. It is also a good opportunity to acknowledge the input of those who participated in the development of this scientific endeavour. [ABSTRACT FROM AUTHOR]

Aims: Myeloblastosis Associated Virus type 1 (N) [MAV 1(N)] induces specifically nephroblastomas in 8-10 weeks when injected to newborn chicken. The MAV-induced nephroblastomas constitute a unique animal model of the pediatric Wilms' tumor. We have made use of three independent nephroblastomas that represent increasing tumor grades, to identify the host DNA regions in which MAV proviral sequences were integrated. METHODS Cellular sequences localized next to MAV-integration sites in the tumor DNAs were used to screen a Bacterial Artificial Chromosomes (BACs) library and isolate BACs containing about 150 kilobases of normal DNA corresponding to MAV integration regions (MIRs). These BACs were mapped on the chicken chromosomes by Fluorescent In Situ Hybridization (FISH) and used for molecular studies. Results: The different MAV integration sites that were conserved after tumor cell selection identify genes involved in the control of cell signaling and proliferation. Syntenic fragments in human DNA contain genes whose products have been involved in normal and pathological kidney development, and several oncogenes responsible for tumorigenesis in human. Conclusion: The identification of putative target genes for MAV provides important clues for the understanding of the MAV pathogenic potential. These studies identified ADAMTS1 as a gene upregulated in MAV-induced nephroblastoma and established that ccn3/nov is not a preferential site of integration for MAV as previously thought. The present results support our hypothesis that the highly efficient and specific MAV-induced tumorigenesis results from the alteration of multiple target genes in differentiating blastemal cells, some of which are required for the progression to highly aggressive stages. This study reinforces our previous conclusions that the MAV-induced nephroblastoma constitutes an excellent model in which to characterize new potential oncogenes and tumor suppressors involved in the establishment and maintenance of tumors. [ABSTRACT FROM AUTHOR]

Aim: To study the cellular distribution of CCN3(NOV) and to determine if the carboxyterminus of CCN3 is hidden or masked due to high affinity interactions with other partners. CCN3 was detected using affinity purified antibodies (anti-K19M-AF) as well as a Protein A purified anti-K19M antibodies (anti-K19M IgG) against a C-terminal 19-aminoacid peptide (K19M) of human CCN3 protein. The antibodies were applied in indirect immunofluorescence tests and immunoenzyme assays on glial tumor cell line, G59, and its CCN3-transfected variant G59/540 and the adrenocortical cell line, NCI-H295R. Results: Anti-K19M-AF antibodies reacted against K19M peptide in ELISA and recognized two bands of 51 kDa and 30 kDa in H295R (adrenocortical carcinoma) cell culture supernatants by immunoblotting. H295R culture supernatants which contained CCN3 as shown by immunoblotting did not react with anti-CCN3 antibodies in liquid phase. Anti-CCN3 antibodies stained the surface membranes of non-permeabilized H295R and cytoplasm in permeabilized H295R cells. Similarly, anti-CCN3 stained surface membranes of G59/540, but did not react with G59 cells. Prominent cytoplasmic staining was observed in G59/540, as well as the cell footprints of G59/540 and H295R were strongly labeled. Conclusions: The K19M-AF antibody directed against the C-terminal 19-aminoacid peptide of CCN3 recognized the secreted protein under denaturing conditions. However, the C-terminal motif of secreted CCN3 was not accessible to K19M-AF in liquid phase. These anti-CCN3 antibodies stained CCN3 protein which was localized to cytoplasmic stores, cell membranes and extracellular matrix. This would suggest that cytoplasmic and cell membrane bound CCN3 has an exposed C-terminus while secreted CCN3 has a sequestered C-terminus which could be due to interaction with other proteins or itself (dimerization). Thus the K19M-AF antibodies revealed at least two conformational states of the native CCN3 protein. [ABSTRACT FROM AUTHOR]

All forms of communication between human beings have long been recognized as a requirement for reciprocal understanding, transfer of knowledge, and productive development of societies. This also applies to living cells who are organized in "microsocieties" that constantly adjust to their environment through a complex network of signaling pathways. The chemical communication which occurs at various levels results in an integrated exchange of information that is essential for coordinated responses. We wish to present a few features of Cell Communication and Signaling: an open access, peerreviewed journal devoted to the publication of manuscripts covering all aspects of cell communication, with a particular focus on molecular processes that govern intercellular signaling and events that sustain cellular communication, both in normal and pathological conditions. The launching of Cell Communication and Signaling provides us the opportunity to present a brief overview of basic processes underlying cell communication and the signaling processes that take place within and between cells to permit an efficient communication. [ABSTRACT FROM AUTHOR]

The CCN (CYR61 [Cystein-rich61]/CTGF [connective tissue growth factor]/NOV [Nephroblastoma overexpressed]) proteins constitute a family of regulatory factors involved in many aspects of cell proliferation and differentiation. An increasing body of evidence indicates that abnormal expression of the CCN proteins is associated to tumourgenesis. The multimodular architecture of the CCN proteins, and the production of truncated isoforms in tumours, raise interesting questions regarding the participation of each individual module to the various biological properties of these proteins. In this article, we review the current data regarding the involvement of CCN proteins in tumourigenesis. We also attempt to provide structural basis for the stimulatory and inhibitory functions of the full length and truncated CCN proteins that are expressed in various tumour tissues. [ABSTRACT FROM AUTHOR]

The CCN family of genes consists presently of six members in human (CCN1-6) also known as Cyr61 (Cystein rich 61), CTGF (Connective Tissue Growth Factor), NOV (Nephroblastoma Overexpressed gene), WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins). Results obtained over the past decade have indicated that CCN proteins are matricellular proteins, which are involved in the regulation of various cellular functions, such as proliferation, differentiation, survival, adhesion and migration. The CCN proteins have recently emerged as regulatory factors involved in both internal and external cell signaling. CCN3 was reported to physically interact with fibulin-1C, integrins, Notch and S100A4. Considering that, the conformation and biological activity of these proteins are dependent upon calcium binding, we hypothesized that CCN3 might be involved in signaling pathways mediated by calcium ions. In this article, we review the data showing that CCN3 regulates the levels of intracellular calcium and discuss potential models that may account for the biological effects of CCN3. [ABSTRACT FROM AUTHOR]

The author focuses on the development of the International CNN Society (ICCNS) as a medium of exchange and diffusion of scientific information on the field of cellular signaling. He explained that the publication of the "Journal of Cell Communication & Signaling" was a major step of the field. On the other hand, the author along with other editorial board members announced their resignation effective September 2007.

Aims: Myeloblastosis Associated Virus type 1 (N) [MAV 1(N)] induces specifically nephroblastomas in 8-10 weeks when injected to newborn chicken. The MAV-induced nephroblastomas constitute a unique animal model of the pediatric Wilms' tumor. We have made use of three independent nephroblastomas that represent increasing tumor grades, to identify the host DNA regions in which MAV proviral sequences were integrated., Methods: Cellular sequences localized next to MAV-integration sites in the tumor DNAs were used to screen a Bacterial Artificial Chromosomes (BACs) library and isolate BACs containing about 150 kilobases of normal DNA corresponding to MAV integration regions (MIRs). These BACs were mapped on the chicken chromosomes by Fluorescent In Situ Hybridization (FISH) and used for molecular studies., Results: The different MAV integration sites that were conserved after tumor cell selection identify genes involved in the control of cell signaling and proliferation. Syntenic fragments in human DNA contain genes whose products have been involved in normal and pathological kidney development, and several oncogenes responsible for tumorigenesis in human., Conclusion: The identification of putative target genes for MAV provides important clues for the understanding of the MAV pathogenic potential. These studies identified ADAMTS1 as a gene upregulated in MAV-induced nephroblastoma and established that ccn3/nov is not a preferential site of integration for MAV as previously thought. The present results support our hypothesis that the highly efficient and specific MAV-induced tumorigenesis results from the alteration of multiple target genes in differentiating blastemal cells, some of which are required for the progression to highly aggressive stages. This study reinforces our previous conclusions that the MAV-induced nephroblastoma constitutes an excellent model in which to characterize new potential oncogenes and tumor suppressors involved in the establishment and maintenance of tumors.