Functional Analysis of Human Beta Defensin-1: Novel Insight into Its Role in Prostate Cancer

Prostate cancer is the second leading cause of cancer-related deaths in men in the United States. The molecular pathogenesis of this disease includes genetic alterations, infection, and exposure to inflammatory or dietary oxidants. Recently, research has focused on the role of host defense peptides in tumor immunity. Defensins, a highly conserved multigene family of proteins that possess antimicrobial and antiviral properties, play an essential role in innate and adaptive immunity. These peptides are categorized into alpha- and beta-defensins based upon the spacing and connection between the six conserved cysteine residues of the mature peptide. Human Beta Defensin-1 (hBD-1), an important component of the innate immune system, is frequently lost in malignant prostate tissue, while expression is maintained in adjacent benign regions. Several studies indicate there may be multiple tumor suppressor genes present within the 8p22-23 region in prostate carcinoma, an area where frequent genetic alterations occur. The high incidence of loss of hBD-1 expression in prostate cancer, along with its chromosomal location of 8p23.2, raised the possibility that it may play a role in tumor suppression. Our studies demonstrated that induction of hBD-1 expression results in significant changes in cell viability, membrane permeability, and the activation of caspase-mediated apoptosis in DU145 and PC3 human prostate cancer cell lines. However, no effect was observed following the induction of hBD-1 in LNCaP. To gain insight into the caspase-mediated cell death, we analyzed the activation of specific caspases within the intrinsic and extrinsic pathway following the induction of hBD-1 expression. In DU145 and PC3 prostate cancer cell lines the activation of both apoptotic pathways was observed, specifically the activation of caspases 3, 8 and 9. However, no caspase activation was observed in the LNCaP prostate cancer cell line. Although our studies suggest that within our expression system and employed methodologies, hBD-1 does not exhibit a \u27bystander effect\u27 on neighboring cells, the results indicate a possible upward trend suggesting that hBD-1 may exhibit a \u27bystander effect\u27 under different conditions than those used in this study. Collectively, this data indicates the loss of hBD-1 in the area surrounding prostate cancer cells may create an environment that promotes the progression of prostate cancer

The colonial ascidian Didemnum sp. A: Current distribution, basic biology and potential threat to marine communities of the northeast and west coasts of North America

Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 342 (2007): 99-108, doi:10.1016/j.jembe.2006.10.020.Didemnum sp. A is a colonial ascidian with rapidly expanding populations on the east and west coasts of North America. The origin of Didemum sp. A is unknown. Populations were first observed on the northeast coast of the U.S. in the late 1980s and on the west coast during the 1990s. It is currently undergoing a massive population explosion and is now a dominant member of many subtidal communities on both coasts. To determine Didemnum sp. A’s current distribution, we conducted surveys from Maine to Virginia on the east coast and from British Columbia to southern California on the west coast of the U.S. between 1998 and 2005. In nearshore locations Didemnum sp. A currently ranges from Eastport, Maine to Shinnecock Bay, New York on the east coast. On the west coast it has been recorded from Humboldt Bay to Port San Luis in California, several sites in Puget Sound, Washington, including a heavily fouled mussel culture facility, and several sites in southwestern British Columbia on and adjacent to oyster and mussel farms. The species also occurs at deeper subtidal sites (up to 81 m) off New England, including Georges, Stellwagen and Tillies Banks. On Georges Bank numerous sites within a 147 km2 area are 50-90% covered by Didemnum sp. A; large colonies cement the pebble gravel into nearly solid mats that may smother infaunal organisms. These observations suggest that Didemnum sp. A has the potential to alter marine communities and affect economically important activities such as fishing and aquaculture.Funding for this project was provided by EPA (STAR) grant GZ1910464 to R.B. Whitlatch, NSF-DGE 0114432 to J. Byrnes, NSF-OCE 0117839 to R. Etter and R.J. Miller, MIT Sea Grant NA86RG0074 and USEPA Grant GX83055701-0 to J. Pederson. RI Sea Grant NA07R90363 to J.S. Collie. Funding for A.N. Cohen and G. Lambert was provided by Mass. Sea Grant, U.S. EPA, Smithsonian Envl. Research Center Invasions Lab, Natl. Geographic Soc., San Francisco Bay-Delta Science Consortium and CALFED Science Program, Calif. Coastal Conservancy and the Rose Foundation. Additional funding and support was provided by the Stellwagen Bank National Marine Sanctuary

Genome, Functional Gene Annotation, and Nuclear Transformation of the Heterokont Oleaginous Alga \u3ci\u3eNannochloropsis oceanica\u3c/i\u3e CCMP1779

Unicellular marine algae have promise for providing sustainable and scalable biofuel feedstocks, although no single species has emerged as a preferred organism. Moreover, adequate molecular and genetic resources prerequisite for the rational engineering of marine algal feedstocks are lacking for most candidate species. Heterokonts of the genus Nannochloropsis naturally have high cellular oil content and are already in use for industrial production of high-value lipid products. First success in applying reverse genetics by targeted gene replacement makes Nannochloropsis oceanica an attractive model to investigate the cell and molecular biology and biochemistry of this fascinating organism group. Here we present the assembly of the 28.7 Mb genome of N. oceanica CCMP1779. RNA sequencing data from nitrogen-replete and nitrogendepleted growth conditions support a total of 11,973 genes, of which in addition to automatic annotation some were manually inspected to predict the biochemical repertoire for this organism. Among others, more than 100 genes putatively related to lipid metabolism, 114 predicted transcription factors, and 109 transcriptional regulators were annotated. Comparison of the N. oceanica CCMP1779 gene repertoire with the recently published N. gaditana genome identified 2,649 genes likely specific to N. oceanica CCMP1779. Many of these N. oceanica–specific genes have putative orthologs in other species or are supported by transcriptional evidence. However, because similarity-based annotations are limited, functions of most of these species-specific genes remain unknown. Aside from the genome sequence and its analysis, protocols for the transformation of N. oceanica CCMP1779 are provided. The availability of genomic and transcriptomic data for Nannochloropsis oceanica CCMP1779, along with efficient transformation protocols, provides a blueprint for future detailed gene functional analysis and genetic engineering of Nannochloropsis species by a growing academic community focused on this genus