Regulation of Steroid Sulfatase by Glucocorticoids in Human Breast Cancer and Bone Cancer Cell Lines

Steroid sulfatase is an enzyme involved in the conversion of active estrogens and androgens from inactive systemic precursors such as estrone sulfate (E1S) and dehydropiandrosterone sulfate (DHEAS). This protein is known to play a role in the fetal-adrenal endocrine axis during pregnancy and it is suspected to have additional physiological functions. Steroid sulfatase has also been implicated in stimulation of hormone-dependent cancers; consequently, a substantial amount of research has been undertaken to develop inhibitors of this enzyme. By comparison, relatively little is known about the regulation of steroid sulfatase. Previous work in our lab had suggested that glucocorticoids may affect steroid sulfatase activity in human breast and bone cells. The purpose of my research was to study the regulation of steroid sulfatase by glucocorticoids in two human cell lines, MDA-MB-231 hormone-independent breast cancer cells, and MG-63 osteosarcoma cells. MDA-MB-231 cells treated for 72 hours with 10 or 1.0µM cortisol showed a decrease in steroid sulfatase activity, as determined by a whole cell radiolabeled steroid conversion assay. Similarly, intact MDA-MB-231 cells treated with 10, 1.0 or 0.1µM dexamethasone showed significantly decreased steroid sulfatase activity. This reduction of steroid sulfatase activity was dose responsive. MDA-MB-231 cell lysates prepared after exposure to dexamethasone provided mixed results with regard to steroid sulfatase activity. The observed decrease in steroid sulfatase activity was not due to competitive inhibition by the glucocorticoids, as neither cortisol nor dexamethasone was found to be competitive inhibitors of steroid sulfatase activity in MDA-MB-231 microsomes. Qualitative analysis of steroid sulfatase mRNA using RT-PCR suggests levels are not affected by dexamethasone. However, quantitative assays must be performed to determine anything conclusive. In contrast to the MDA-MB-231 results, MG-63 bone precursor cells showed no change in steroid sulfatase activity after exposure to dexamethasone for 24 or 96 hours. However, MG-63 cell lysates demonstrated an upregulation in steroid sulfatase activity at the 96h time period. Data from this study indicate that glucocorticoids can influence steroid sulfatase activity in human breast and bone cells

On-site Analysis of Trace Elements Using Liquid Electrode Plasma-Optical Emission Spectrometry Combined with Solid-Phase Extraction

13301甲第4819号博士（学術）金沢大学博士論文要旨Abstract 要約Outlin

Application of Length-Based Assessment Methods to Elucidate Biological Reference Points of Black Pomfret Stock in the Bay of Bengal, Bangladesh

The black pomfret (Parastromateus niger) is one of the high-income-generating carangid fish species and the only known member of its genus. This study aims to identify existing gaps in stock status and population demography of this species and provide viable management recommendations to enhance the sustainability of this fishery. Therefore, three methodological approaches have been used in this study; TropFishR to present the current exploitation status, the length-based spawning potential ratio (LB-SPR) to quantify stock spawning biomass, and Froese’s sustainability indicators (LBI) to establish a basic standard for sustainable management of the fishery. In the length-weight relationship of black pomfret, an allometric growth pattern (b = 2.19) was found. The VBGF life history parameters for black pomfret were L∞ = 55.25 cm, K = 0.54 year−1, and based on LCCC analysis, the total mortality (Z = 1.61 year−1), natural mortality (M = 0.69 year−1) and fishing mortality (F = 0.91 year−1) are calculated. The result reveals that this fishery is currently suffering from overexploitation and the stock’s spawning biomass (SPR = 13%) is below the limit reference point because most of the catch (82%) was found to be under the maturity level. Based on the results, this study recommended strictly maintaining the mesh size of the net to ensure not to catch immature fish with a length smaller than 30.63 cm, recommended the length to catch be between 29 and 35 cm, and reducing fishing pressure by one-third to ensure the sustainability of the black pomfret fishery

Stock Assessment and Rebuilding of Two Major Shrimp Fisheries (Penaeus monodon and Metapenaeus monoceros) from the Industrial Fishing Zone of Bangladesh

The two economically important shrimp species in Bangladesh are the tiger shrimp, Penaeus monodon, and the brown shrimp, Metapenaeus monoceros. However, a continuous decline in the landing of these species from the industrial trawling made it critical to assess their stock biomass status to explore their response to the present degree of removal. Given the minimum data requirement and robustness, this study employed the depletion-based stock reduction analysis (DB-SRA) to assess these fisheries rigorously. For the industrial fishing zone (beyond the 40 m depth in the EEZ of Bangladesh), the estimated historic mean carrying capacity (K) was 5015 metric tons for the Penaeus monodon and 35,871 metric tons for Metapenaeus monoceros. The estimated overfishing limits (OFL), which were much smaller than the reported catches throughout the time series, indicate the overfishing status of these fisheries. As a result, the estimated biomass for the reference year (B2020) for both species was lower than BMSY, indicating that these fisheries are not producing MSY. Therefore, for the rebuilding and sustainable management of these stocks, this study recommended a catch limit of 100 metric tons for P. monodon and 750 metric tons for M. monoceros for the next ten years from biomass projections

Stock Assessment and Rebuilding of Two Major Shrimp Fisheries (Penaeus monodon and Metapenaeus monoceros) from the Industrial Fishing Zone of Bangladesh

The two economically important shrimp species in Bangladesh are the tiger shrimp, Penaeus monodon, and the brown shrimp, Metapenaeus monoceros. However, a continuous decline in the landing of these species from the industrial trawling made it critical to assess their stock biomass status to explore their response to the present degree of removal. Given the minimum data requirement and robustness, this study employed the depletion-based stock reduction analysis (DB-SRA) to assess these fisheries rigorously. For the industrial fishing zone (beyond the 40 m depth in the EEZ of Bangladesh), the estimated historic mean carrying capacity (K) was 5015 metric tons for the Penaeus monodon and 35,871 metric tons for Metapenaeus monoceros. The estimated overfishing limits (OFL), which were much smaller than the reported catches throughout the time series, indicate the overfishing status of these fisheries. As a result, the estimated biomass for the reference year (B2020) for both species was lower than BMSY, indicating that these fisheries are not producing MSY. Therefore, for the rebuilding and sustainable management of these stocks, this study recommended a catch limit of 100 metric tons for P. monodon and 750 metric tons for M. monoceros for the next ten years from biomass projections

Physicochemical properties of moringa oleifera Lam. seed oil of the indigenous-cultivar of Bangladesh

金沢大学理工研究域物質化学系Moringa oleifera Lam. seed oil of the indigenous-cultivar of Bangladesh was extracted using n-hexane (H), light petroleum ether (LPE) (bp 40-60C) and chloroform/methanol (50:50, v/v) mixture (CM). The oil content ranged from 37.50 (H) to 40.20% (CM). The moisture, protein, ash and crude fiber contents of seed residues, and the density, refractive index, color, acidity, saponification value, iodine value, unsaponifiable matter content, oxidative state, sterols, tocopherols and fatty acid composition of the extracted oil were determined. The oil contained a high amount of oleic acid (C18:1) of up to 74.41% and a high ratio of monounsaturated to saturated fatty acids with moderate oxidative stability. The results of the present study were compared with those reported in literature for different regional habitats and species variants. © 2009, Wiley Periodicals, Inc

Length-Based Stock Assessment for the Data-Poor Bombay Duck Fishery from the Northern Bay of Bengal Coast, Bangladesh

The Bombay duck (Harpadon nehereus) forms the second-largest single-species marine fishery in Bangladesh and therefore has a significant impact on the local economy, providing employment, food, and nutrition to thousands of people. Despite the immense importance, this fishery has never been a priority for the relevant regulatory authorities. To enhance the sustainability of this fishery, an effective management policy based on the scientific evaluation of the current stock’s status is urgently required. Therefore, this study used three methodological approaches (traditional size structure-based stock assessment to reveal current exploitation status; the length-based spawning potential ratio (LB-SPR) to evaluate the stock’s spawning biomass; and Froese’s sustainability indicators for sustainable fishing) to conduct a thorough assessment of the Bombay duck stock to establish basic standards for the sustainable management of this fishery. The results revealed that this fishery is presently suffering from overexploitation and the stock’s spawning biomass (SPR = 8%) is below the limit reference point because of the juvenile-oriented fishing behavior of the fishery. Based on the outputs, this study recommended the mesh size regulation of the set bag nets (SBNs) (5 cm mesh size for the codend) to ensure not to catch immature fishes with a length equal to or smaller than 17.95 cm; and reduce the existing number of SBNs by half to reduce fishing pressure on the stock to ensure the sustainability of this fishery

Length-Based Stock Assessment for the Data-Poor Bombay Duck Fishery from the Northern Bay of Bengal Coast, Bangladesh

The Bombay duck (Harpadon nehereus) forms the second-largest single-species marine fishery in Bangladesh and therefore has a significant impact on the local economy, providing employment, food, and nutrition to thousands of people. Despite the immense importance, this fishery has never been a priority for the relevant regulatory authorities. To enhance the sustainability of this fishery, an effective management policy based on the scientific evaluation of the current stock’s status is urgently required. Therefore, this study used three methodological approaches (traditional size structure-based stock assessment to reveal current exploitation status; the length-based spawning potential ratio (LB-SPR) to evaluate the stock’s spawning biomass; and Froese’s sustainability indicators for sustainable fishing) to conduct a thorough assessment of the Bombay duck stock to establish basic standards for the sustainable management of this fishery. The results revealed that this fishery is presently suffering from overexploitation and the stock’s spawning biomass (SPR = 8%) is below the limit reference point because of the juvenile-oriented fishing behavior of the fishery. Based on the outputs, this study recommended the mesh size regulation of the set bag nets (SBNs) (5 cm mesh size for the codend) to ensure not to catch immature fishes with a length equal to or smaller than 17.95 cm; and reduce the existing number of SBNs by half to reduce fishing pressure on the stock to ensure the sustainability of this fishery