8th World Congress and Expo on Cell & Stem Cell Research March 20-22, 2017 Orlando, Florida, USA

Diana Anderson (H index 54) holds the Established Chair in Biomedical Sciences at the University of Bradford. She obtained her first degree in the University of Wales and second degrees in the Faculty of Medicine, University of Manchester. She has 450+ peer-reviewed papers, 9 books, and has successfully supervised 28 PhDs. She is an Editorial Board Member of 10 international journals. She is Editor in Chief of a book series on Toxicology for the Royal Society of Chemistry. She gives key note addresses at various international meetings. She is a consultant for many international organisations, including WHO, EU, NATO, TWAS, UNIDO, OECD

The spermatogonial stem cells (SSCs) are responsible for the transmission of genetic information from an individual to the next generation. SSCs play a very important role in the maintenance of normal tissue and provide an understanding of the rudimentary reproductive biology of gametes and a strategy for diagnosis and treatment of infertility and male reproductive toxicology. The balance between hormonal androgens/oestrogens is very important for the suitable maintenance of male germ cells, because there is evidence confirming the damaging effects of oestrogen-like compounds on male reproductive health. We investigated the effects in vitro, of diethylstilbestrol (DES) on mouse spermatogonial stem cells isolated using Staput unitgravity velocity sedimentation, evaluating any DNA damage using the Comet assay and apoptotic cells with the TUNEL assay. Immunocytochemistry assays showed that the purity of isolated spermatogonial cells was 90% and the viability over 96%. Intracellular superoxide anion production in SSCs was detected by the p-Nitro Blue Tetrazolium (NBT) assay. The results showed DES-induced DNA damage, increased apoptotic cells, and increased production of intracellular superoxide anions. Investigating the mechanisms and biology of SSCs in this way helps to provide a better understanding of spermatogonial stem cell regulation.

Georg F Weber has attended Medical School in Wurzburg, Germany. He worked at the Dana-Farber Cancer Institute, Harvard Medical School from 1990 to 1999 and is currently, working as a Faculty at the University of Cincinnati. He has published close to 100 scientific reports, including many in the most respected professional journals and various monographs, including textbooks on molecular oncology and anti-cancer drugs. His research has made key contributions to understanding the molecular mechanisms of metastasis.

Metastasis formation is an essential aspect of cancer. While the organ preference for dissemination is governed to some degree by tumor-host interactions, there is an intrinsic genetic basis underlying the ability of cancer cells to disseminate to specific distant sites. Metastasis genes are comprised of developmentally non-essential stress response genes, which encode homing receptors, their ligands and extracellular matrix-degrading proteinases. They jointly cause invasion and anchorageindependence. Metastatic potential is conferred to cancer cells by aberrant expression or splicing of these genes, which include osteopontin. The osteopontin gene product is subject to alternative splicing, which yields three RNA messages, osteopontin-a (full length), osteopontin-b (lacking exon 5) and osteopontin-c (lacking exon 4). The shorter forms -b and -c are differentially expressed in cancers, but are absent from healthy tissues. The major limiting factor in the process of metastasis formation is the death of the tumor cells before their implantation in target organs. Hence, anchorage-independent survival is required for cancer spread. The detachment of mammary epithelial cells prompts a loss of glucose transport and resulting ATP deficiency, thus compromising the energy metabolism and causing apoptosis. In invasive breast tumor cells, osteopontin-A and osteopontin-C synergize in supporting tumor progression via up-regulating the energy production, which leads to deadherent survival. Osteopontin splice variants hold promise as potential drug targets. While aberrant expression or splicing of metastasis genes conveys to cancers the ability to break through tissue barriers and disseminate, the genetic basis for organ preference in cancer spread has remained incompletely understood. Metastases are generally characterized by a gene expression core program associated with tissue remodeling (a stress response) that distinguishes metastases from their originating primary tumors as well as from their target host tissues. Site-selectivity is accomplished through a specific program component that adjusts to the target micro-environment. It remains to be investigated whether the gene expression profile of metastases precedes implantation and thus determines organ preference or is shaped by the target site and is thus a consequence of implantation.

Chemotherapy of metastatic cancer might be more efficacious if selected to match the genetic makeup of the metastases rather than the organ of origin by the primary tumor.