Amino acids a re required fo1' protein synthesis and energy sources in all living cell s. System L amino acid trans porters neutral amino aci cls i n a Na +' - independent manner. In ma 1ignan t tumors the L-type amino acid t ranspor te r 1(LA1'1), the first isoform 0 1' system L. is highly expressed to suppor t tumo1' cell growth. ln the present study, the expression 0 1' the system L amino acid transporter and BCH cytotoxicity were examined and compa red in both rat gli a l and C6 g lioma cel ls 1'he rat glia l cells expressed the L-type arnino acid t ra nsporter 2(LA1'2). the second isoform 이 system L, with its subu ni t 4F2hc. whereas the LA1'1 was not expressed. 1'he C6 glioma cells expressed LA1'1 with 4F2hc but not LA1'2 1'he [14C]L-leucine uptakes by the glial and C6 glioma cells were inhibi ted by BCH in a co ncent ration-d e pendant man ner wi th the lC50 values of 270.0 :t 13.7 μ M and 73.1 :t 4.5 μ M, respectively. 1'he cell g rowth was inh ibi ted by BCH in the time, concen tration-dependant manner in the gli al and C6 glioma cell s . 1'he rate of cell growth inhi bit ion induced by BCH in the C6 glioma cells was hi gh er than that in the gli al cells 1'hese results s uggesL that the tra ns ports of neutra l amino acids inc1uding several essenti al amino acids into rat g lial and C6 glioma cel ls a re for the most part mediated by LA1'2 and LA1'1, respectively. Therefore‘ the rat glia1 and C6 gJioma cells are excell ent tools for examing the proper ties of LA1'2 and LA1'1, respectively. Moreover, the spec너 i c inh ibi tion 0 1' LATl in cancel cells might be a new rationa le f'or anti -cancer therapy

Arrùno acid transpoπers play an important role in supplying nutrition to cells and for cell proliferation. System L is a major nutrient transport system responsible for the Na+-independent transport of large neutral amino acids including several essential amino acids. In malignant tumors, a system L transporter L-type amino acid transporter 1 (LATl) is upregulated to support tumor cell growth. In the present study, we have examined the expression and function of system L amino acid transporter in FaDu human pharyngeal squamous carcinoma cells. RT-PCR, real-time quantitative RT-PCR and westem blot analysis have revealed that the FaDu cells express LATl together with its associaω19 protem 4F2hc, whereas the FaDu cells do not express the other system L isoform L-type amino acid transporter 2 (LAT2). 까le uptake of L-(14Clleucine by FaDu cells is Na+-independent and almost completely inhibited by system L selective inhibitor 2-aminobicyclo-(2,2,1)-heptane-2- carboxylic acid (BCH). The profiles of the inhibition of L-[I4Cllellcine uptake by variolls amino acids in the FaDu cells are comparable with those for the LA T1 expressed in Xenopus 。()(찌es. π1e majority of L-[I4Clleucine uptake is, therefore, mediated by LAT1 in the FaDu cells. These results suggest that the transport of neutral amino acids including several essential amino acids in the FaDu human pharyngeal squamous carcinoma cells mediated by LAT1. In addition, specific inhibition of LAT1 by such agents as BCH in pharyngeal squamous cell carcinomas will be a new rationale for anti-cancer therapy.

본 연구에서는 실물 어구를 이용한 해상실험을 통하여 예망 중인 어구의 망구 형상을 해석하기 위해서 예망 속도, 어구의 저항, 전개판의 간격, 망고 등을 계측ㆍ분석하였다. 또한 망구 형상을 이론적으로 계산하기 위해서 망구의 형상을 지배하는 뜸줄, 발줄 및 옆줄의 모양을 현수곡선으로 간주하고 수학모텔을 기술하여 수치해석 하였고, 이 결과를 실제 측정된 값과 비교하여 모텔의 타당성을 검토하였다. 본 실험에 대한결과를 요약하면 다음과 같다. 1. 선속의 변화에 따라 크게 변하는 요소로는 장력과 망고였고, 끌줄 길이의 변화에 민감하게 반응한 것은 어구 수심과 전개판의 간격이었다. 2. 계측된 트롤 어구의 상태량을 토대로 뜸줄 및 옆줄의 형상을 수치해석한 결과, 선속이 증가함에 따라 뜸줄 및 발줄의 폭과 옆줄의 높이는 감소하였고, 뜸풀 및 옆줄 중앙부의 처짐 정도는 증가하였다. 3. 예망속도에 따른 망고변화에 대하여 수치해석한 결과와 실제 실험에서 얻은 데이터를 비교한 결과, 비교적 양호한 결과를 얻을 수 있었다. 4. 수치해석한 결과로부터 망구의 형상을 추정한 결과, 선속이 증가함에 따라 횡축으로 긴 직사각형의 형상이 나타났으며, 횡축 및 종축 모두 크기가 감소하였다.