本院延聘美國杜克醫學中心生物化學系謝道時教授回國接任本所特聘研究員兼所長。所長聘期自98年6月15日起至101年6月14日止，任期三年。已於6月19日(星期五)由翁院長親自主持，完成交接儀式。

謝道時特聘研究員兼任所長簡介
專長 :Biochemistry

2009-     細胞與個體生物學研究所特聘研究員兼任所長
1993-     美國杜克醫學中心生物化學系教授 
1977      Ph. D. 加州大學柏克萊分校生物物理化學

background: Clinical-grade human embryonic stem cells (hESCs) ideally should be derived and maintained in xeno-free culture conditions using defined chemicals or materials of human origin. This will reduce the possibility of xeno-derived pathogenic infection and/or unfavorable immune reaction in clinical application. The present study therefore aimed to derive autogenic feeders from hESCs and evaluate their capability to support the pluripotency of hESCs in xeno-free culture conditions.
methods and results: H9 hESCs were cultured in media containing human serum (HS), serum replacement (SR) or KFM combination,to generate autogenic feeders (named HSdF, SRdF and KFMdF, respectively). Reverse transcription polymerase chain reaction, flow cytometry and immunofluorescence analysis using pluripotent stem cell markers, markers of early cell lineages and surface markers revealed that HSdF, SRdF and KFMdF likely belonged to different cellular subpopulations. The efficiency of the autogenic feeders in maintaining pluripotency of H9 hESCs using media containing SR, fetal bovine serum, HS or 1% HS plus various combinations of growth factors was evaluated by flow cytometric analysis of Oct4 expression. All three autogenic feeders were shown to be capable of maintaining the undifferentiated status of H9 hESCs in SR-containing media in long-term culture. When supplemented with bFGF, activin A and noggin, hESCs could also be maintained favorably on KFMdF in a medium containing 1% HS without losing their pluripotent potentials both in vitro and in vivo.
conclusions: Novel autogenic feeders can be derived from hESCs under xeno-free conditions and they can robustly maintain the pluripotent identity of hESCs in xeno-free media containing a low concentration of HS.
Key words: autogenic feeder / embryonic stem cells / pluripotency / human serum / xeno-free culture

Lung cancer is the leading cause of cancer-related mortality worldwide. The lack of tumor specificity remains a major drawback for effective chemotherapies and results in dose-limiting toxicities. However, a ligand-mediated drug delivery system should be able to render chemotherapy more specific to tumor cells and less toxic to normal tissues. In this study, we isolated a novel peptide ligand from a phage-displayed peptide library that bound to non-small cell lung cancer (NSCLC) cell lines. The targeting phage bound to several NSCLC cell lines but not to normal cells. Both the targeting phage and the synthetic peptide recognized the surgical specimens of NSCLC with a positive rate of 75% (27 of 36 specimens). In severe combined immunodeficiency (SCID) mice bearing NSCLC xenografts, the targeting phage specifically bound to tumor masses. The tumor homing ability of the targeting phage was inhibited by the cognate synthetic peptide, but not by a control or a WTY-mutated peptide. When the targeting peptide was coupled to liposomes carrying doxorubicin or vinorelbine, the therapeutic index of the chemotherapeutic agents and the survival rates of mice with human lung cancer xenografts markedly increased. Furthermore, the targeting liposomes increased drug accumulation in tumor tissues by 5.7-fold compared with free drugs and enhanced cancer cell apoptosis resulting from a higher concentration of bioavailable doxorubicin. The current study suggests that this tumor-specific peptide may be used to create chemotherapies specifically targeting tumor cells in the treatment of NSCLC and to design targeted gene transfer vectors or it may be used one in the diagnosis of this malignancy.