1.Potentials of Chinese herbal medicine in ameliorating septic shock2.Fucosyltransferases in breast cancer

• Main Authors: Peishan Lee, 李佩珊
• Other Authors: Chi-huey Wong
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/18751574525544921553

碩士 === 國立臺灣大學 === 生化科學研究所 === 95 === Section I. Potentials of Chinese herbal medicine in ameliorating septic shock Previous studies have shown that the fucose-containing glycoprotein fraction 3 (Reishi-F3) purified from the ancient Chinese herb – Ganoderma lucidum (Reishi) extract contains active components that could activate immune cells and exhibit anti-tumor properties. Although these studies pointed out the feasibility of Reishi-F3 as a potential botanical drug, like any other investigational agent, Reishi-F3 must show evidence of relative purity, safety, and effectiveness before it can be used in the clinical trials. Despite of the fact that it was shown earlier that Reishi-F3 was adjudged pyrogenic by both the rabbit pyrogen test and the Limulus amebocyte lysate test, we argued that the pyrogenicity of Reishi-F3 may not be entirely attributed to the contamination by endotoxins. With this goal in mind, we sought to distinguish the biological properties of lipopolysaccharide (LPS) and Reishi-F3 by the LPS-induced mortality test in mice. While a majority of the mice which received a lethal dose of LPS died within 48 hours after injection, mice injected with an equivalent dose of Reishi-F3 showed 100% survivability. We also followed up by assaying the levels of different cytokines in the serum samples of each mouse. Interestingly, we noted the inductions of many of the pro-inflammatory cytokines such as interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were missing in mice treated with Reishi-F3. Furthermore, Reishi-F3 induced a higher serum level of IL-10 in comparison to LPS. Based on our results above, we were interested in investigating whether Reishi-F3 possesses anti-inflammatory properties. Unfortunately, we determined that the pre-treatment of Reishi-F3 does not protect the mice from later challenge with LPS. Hirsutella hepiali (Hirsutella) is the proprietary strain of the popular Chinese herbal medicine Cordyceps sinensis. It has been reported that Cordyceps sinensis could protect against viral infection and suppress inflammation. We discovered that pre-treatment of mice with the crude extract of Hirsutella could indeed protect the mice from LPS-induced endotoxic lethality. By monitoring the levels of different cytokines in the mouse serum after treatment of Hirsutella and subsequent injection of LPS, we showed that treatment of Hirsutella alone at relatively low dose was capable of lowering the levels of several cytokines in the mouse serum. More importantly, treatment with Hirsutella appears to prime the animal for later exposure to LPS, resulting in increased secretion of the cytokine IL-1 receptor antagonist (IL-1Ra) upon LPS challenge. On the other hand, measurement of IL-1Ra suggested that Hirsutella alone would not lead to an increase in the secretion of IL-1Ra into the mouse serum. Since IL-1Ra is known as an inhibitor of IL-1 and attenuate injury caused by inflammation, we surmised that Hirsutella ameliorates LPS-induced endotoxic shock via an increased production of IL-1Ra, though the exact mechanism has yet to be determined. Section II: Fucosyltransferases in breast cancer Fucose is a deoxyhexose that is commonly found as a terminal modification of many N- and O-linked glycans. The transfer of fucose residues onto existing glycan structures is carried out by enzymes known as fucosyltransferases and 13 fucosyltransferases have been identified in the human genome thus far. Fucosylated glycans have been implicated in the pathogenesis of several human diseases including cancer, in which altered expressions of particular type of fucosylated epitopes were often seen on the surface of tumor cells. However, it remains to be resolved whether carcinogenesis could be directly linked to the changes in the expressions of the fucosyltransferase. We therefore determined the expression levels of all 13 fucosyltransferase genes in 63 pairs of primary breast tumor and normal specimens. Pre-processing of the data by Genespring clustering analysis showed that the normal and tumor samples roughly formed their own distinct clusters and were easily distinguishable. Statistical analyses also indicated correlation between the expression profiles of FUT genes with tumor grade, size, stage, and status of predictive markers such as the estrogen and progesterone receptors and HER-2. Interestingly, we found that the expressions of FUT1, FUT4-5, FUT8, and FUT10-13 were significantly downregulated in breast tumors as opposed to normal tissues, whereas increased expressions of FUT2 and FUT7 were seen in most tumor samples. Here, we also relate our findings to the current knowledge of fucosyltransferases and fucosylation patterns from scientific publications, though more thorough studies are needed to further examine the actual functions and products of each fucosyltransferase in order to clarify the roles these enzymes play in the development of breast cancer.