The International Journal of Developmental Biology 

About: The International Journal of Developmental Biology is an academic journal published by University of the Basque Country. The journal publishes majorly in the area(s): Cellular differentiation & Xenopus. It has an ISSN identifier of 0214-6282. It is also open access. Over the lifetime, 3312 publications have been published receiving 115413 citations. The journal is also known as: International Journal of Developmental Biology.

Endocrine regulation of gametogenesis in fish.

Abstract: The pituitary-gonadal axis plays an important role in regulating gametogenesis in vertebrates. In most cases, gonadotropins act through the biosynthesis of gonadal steroid hormones which in turn mediate various stages of gametogenesis. A series of studies in our laboratory using several species of teleost fishes as experimental animals has provided new information about the endocrine regulation of gametogenesis, including oocyte growth, oocyte maturation, spermatogenesis and sperm maturation. This article briefly reviews our findings on the identification of steroidal mediators involved in each process of gametogenesis, and the sites and mechanisms of action of the mediators. These observations collectively demonstrate the appropriateness of using teleost fishes as valid models for examining hormonal influences on gametogenesis. Such models could also have applications and validity for vertebrates in general.

Matrix metalloproteinases in cancer: from new functions to improved inhibition strategies.

Abstract: Over the last years, the relevance of the matrix metalloproteinase (MMP) family in cancer research has grown considerably. These enzymes were initially associated with the invasive properties of tumour cells, owing to their ability to degrade all major protein components of the extracellular matrix (ECM) and basement membranes. However, further studies have demonstrated the implication of MMPs in early steps of tumour evolution, including stimulation of cell proliferation and modulation of angiogenesis. The establishment of causal relationships between MMP overproduction in tumour or stromal cells and cancer progression has prompted the development of clinical trials with a series of inhibitors designed to block the proteolytic activity of these enzymes. Unfortunately, the results derived from using broad-spectrum MMP inhibitors (MMPIs) for treating patients with advanced cancer have been disappointing in most cases. There are several putative explanations for the lack of success of these MMPIs including the recent finding that some MMPs may play a paradoxical protective role in tumour progression. These observations together with the identification of novel functions for MMPs in early stages of cancer have made necessary a reformulation of MMP inhibition strategies. A better understanding of the functional complexity of this proteolytic system and global approaches to identify the relevant MMPs which must be targeted in each individual cancer patient, will be necessary to clarify whether MMP inhibition may be part of future therapies against cancer.

Transcriptional regulation of cadherins during development and carcinogenesis

Abstract: The cadherin superfamily of Ca(2+)-dependent homophilic adhesion molecules plays a critical role in regulating cell-to-cell interactions. During development, the expression of different cadherins is highly dynamic, since they are associated with the morphogenesis, establishment and/or maintenance of different tissues. Alterations in cadherin expression or function occur frequently during carcinogenesis, such as the loss of the epithelial cadherin (E-cadherin) and/or the aberrant expression of other cadherins. Indeed, the aberrant expression of cadherins has been detected during carcinoma invasion, a process which is reminiscent of the epithelial-mesenchymal transition (EMT) so important in many critical developmental processes. The functional regulation of cadherins can occur at many different levels, from transcriptional regulation to the control of the strength of the cadherin-mediated cell-cell interaction. In this review, we will focus on the transcriptional control of cadherin expression, both in development and carcinogenesis, paying particular attention to the regulation of E-cadherin given its proposed role as a suppressor of invasion. We will discuss the main genetic and epigenetic mechanisms involved in down-regulating E-cadherin expression, and we will analyse the mechanisms involved in regulating EMT, in an attempt to elucidate which elements are common to this process in both physiological and pathological situations.

Transplantation of testis germinal cells into mouse seminiferous tubules.

Abstract: In the adult male, germ cell differentiation takes place in the seminiferous tubules of the testis by a complex, highly organized and very efficient process. A population of diploid stem-cell spermatogonia that lie on the basement membrane of the tubule continuously undergoes self-renewal and produces progeny cells, which initiate the process of cellular differentiation to generate mature spermatozoa. Each testis contains many seminiferous tubules, which are connected at both ends to a collecting system called the rete testis. The mature spermatozoa pass from the tubules into the rete and are then carried through efferent ducts to the epididymis for final maturation before they are ready to fertilize an egg. In previous studies, we have demonstrated that donor testis cells collected from a fertile mouse are able to generate spermatogenesis when transplanted to the seminiferous tubules of an infertile male. The spermatozoa produced by the recipient from the donor-derived spermatogonial stem cells are able to fertilize eggs and produce progeny carrying the donor male haplotype. Furthermore, donor testis stem cells from a rat will generate normal rat spermatozoa following transplantation to a mouse testis. The spermatogonial transplantation technique is clearly valuable and applicable to many species, but it is difficult. Therefore, several procedures to introduce donor cells into the seminiferous tubules of a recipient have been developed using the mouse as a model, and they are described here in detail. The results indicate that microinjection of cell suspensions into the seminiferous tubules, efferent ducts or rete testis are equally effective in generating donor cell-derived spermatogenesis in recipients. Each approach is likely to be useful for different experimental purposes in a variety of species.

The stroma reaction myofibroblast: a key player in the control of tumor cell behavior.

Abstract: The cooperation between epithelial and mesenchymal cells is essential for embryonic development and probably plays an important role in pathological phenomena such as wound healing and tumor progression. It is well known that many epithelial tumors are characterized by the local accumulation of connective tissue cells and extracellular material; this phenomenon has been called the stroma reaction. One of the cellular components of the stroma reaction is the myofibroblast, a modulated fibroblast which has acquired the capacity to neoexpress α-smooth muscle actin, the actin isoform typical of vascular smooth muscle cells, and to synthesize important amounts of collagen and other extracellular matrix components. It is now well accepted that the myofibroblast is a key cell for the connective tissue remodeling which takes place during wound healing and fibrosis development. Myofibrobasts are capable of remodeling connective tissue but also interact with epithelial cells and other connective tissue cells and may thus control such phenomena as tumor invasion and angiogenesis. In this review we discuss the mechanisms of myofibroblast evolution during fibrotic and malignant conditions and the interaction of myofibroblasts with other cells in order to control tumor progression. On this basis we suggest that the myofibroblast may represent a new important target of antitumor therapy.