Two Estrogen Response Element Sequences Near the PCNA Gene Are Not Responsible for Its Estrogen-Enhanced Expression in MCF7 Cells

The proliferating cell nuclear antigen (PCNA) is an essential component of DNA replication, cell cycle regulation, and epigenetic inheritance. High expression of PCNA is associated with poor prognosis in patients with breast cancer. The 5'-region of the PCNA gene contains two computationally-detected estrogen response element (ERE) sequences, one of which is evolutionarily conserved. Both of these sequences are of undocumented cis-regulatory function. We recently demonstrated that estradiol (E2) enhances PCNA mRNA expression in MCF7 breast cancer cells. MCF7 cells proliferate in response to E2.Here, we demonstrate that E2 rapidly enhanced PCNA mRNA and protein expression in a process that requires ERalpha as well as de novo protein synthesis. One of the two upstream ERE sequences was specifically bound by ERalpha-containing protein complexes, in vitro, in gel shift analysis. Yet, each ERE sequence, when cloned as a single copy, or when engineered as two tandem copies of the ERE-containing sequence, was not capable of activating a luciferase reporter construct in response to E2. In MCF7 cells, neither ERE-containing genomic region demonstrated E2-dependent recruitment of ERalpha by sensitive ChIP-PCR assays.We conclude that E2 enhances PCNA gene expression by an indirect process and that computational detection of EREs, even when evolutionarily conserved and when near E2-responsive genes, requires biochemical validation

Damage survivability of RO-RO ferries

The survival capability of damaged ships under dynamic sea conditions has been the subject of technical investigations since the early 1960's. Building upon this base of knowledge, a research program was initiated in Canada in 1991 to investigate the prime factors affecting the survival of RO-RO passenger ferries when flooded symmetrically after damage at midship.NRC publication: Ye

Flooding protection of Ro-Ro ferries

The survival capability of damaged ships under dynamic sea conditions has been the subject of technical investigations since the early 1 9W's. Building upon this base of knowledge, a research program was initiated in Canada to investigate the prime factors affecting the survival of Ro-Ro passenger ferries when flooded symmetrically after damage at midship. This effort would form an initial phase in the development of criteria for assessing Ro-Ro capsize safety after damage in sea states. A comprehensive model test program was devised to systematically examine the capsize phenomenon in sea states up to 7 metres significant wave height, using a model which replicated the design characteristics and proportions of large Canadian flag ferries. The vertical centre of gravity of the model was varied over a range of test conditions which met SOLAS 90 damage stability criteria. Using time history traces and summary data sheets, the test results were analysed to identify patterns of repeatable behaviour. Examined were the maximum upright and minimum capsize conditions of the ship in each test case. Prime variables used to make assessments under dynamic sea conditions are metacentric height and dynamic stability in the damaged condition. conclusions are drawn using these prime variables with respect to their relationship to residual freeboard after damage, freeing port area and presence of a centreline casing. In addition, findings are made on the behaviour of water accumulation on the vehicle deck which may assist in establishing criteria serving to design for capsize prevention in the future.Peer reviewed: YesNRC publication: Ye

Flooding protection of Ro-Ro ferries

The survival capability of damaged ships under dynamic sea conditions has been the subject of technical investigations since the early 1 9W's. Building upon this base of knowledge, a research program was initiated in Canada to investigate the prime factors affecting the survival of Ro-Ro passenger ferries when flooded symmetrically after damage at midship. This effort would form an initial phase in the development of criteria for assessing Ro-Ro capsize safety after damage in sea states. A comprehensive model test program was devised to systematically examine the capsize phenomenon in sea states up to 7 metres significant wave height, using a model which replicated the design characteristics and proportions of large Canadian flag ferries. The vertical centre of gravity of the model was varied over a range of test conditions which met SOLAS 90 damage stability criteria. Using time history traces and summary data sheets, the test results were analysed to identify patterns of repeatable behaviour. Examined were the maximum upright and minimum capsize conditions of the ship in each test case. Prime variables used to make assessments under dynamic sea conditions are metacentric height and dynamic stability in the damaged condition. conclusions are drawn using these prime variables with respect to their relationship to residual freeboard after damage, freeing port area and presence of a centreline casing. In addition, findings are made on the behaviour of water accumulation on the vehicle deck which may assist in establishing criteria serving to design for capsize prevention in the future.Peer reviewed: YesNRC publication: Ye