암환자의 체액에서 real-time TRAP assay를 이용한 telomerase 활성도 측정
Detection of telomerase activity from body fluids in cancer patients by real-time TRAP assay
암환자의 복수나 흉수와 같은 체액에서 암세포의 검출은 복막, 흉막 재발의 좋은 예견 인자이며 이와 같은 환자에게 적절한 복강, 흉강 내 항암치료를 시행하기 위한 판단 기준이 되고 있다. 이런 기준에 따른 항암치료를 위해서는 보다 정확하고 빠른 검사법이 요구된다.
체액 내 암세포의 검출을 위해서 세포병리검사가 널리 사용되지만, 임상에 적용할 만한 민감도와 특이성을 나타내지 못했다. 따라서 새로운 생물학적 표지자를 확인하기 위한 많은 노력이 있었다.
Telomerase는 DNA 복제시 염색체 말단의 길이를 유지하는 리보핵단백질 (ribonucleoprotein)로서 정상 체세포에서는 발현되지 않고, 대부분의 악성종양에서는 높은 효소 활성도를 나타내므로 악성종양에 대한 표지자로서 사용되어 졌다. 현재 telomerase 활성도를 검출하기 위해서 민감도와 특이성이 높은 TRAP assay (telomeric repeat amplification protocol)가 사용되고 있지만, TRAP assay는 많은 시간과 노동력이 들고 정확한 정량이 어려운 단점이 있다. 본 연구에서는 이를 보완하기 위해서 TRAP assay에 real-time PCR을 응용하여 민감도가 향상되고 정확한 정량이 가능한 real-time TRAP assay 조건을 확립하였다. 또한 암환자의 체액에서 세포병리검사 결과와 TRAP assay 및 real-time TRAP assay에 의한 telomerase 활성도를 비교하였다.
첫 번째로 293 세포주의 핵단백질을 이용한 telomerase 활성도의 최소 검출 범위는 TRAP assay에서 0.04 ㎍에 비하여 real-time TRAP assay에서는 0.0016 ㎍으로 민감도가 25배 증가하였다. 두 번째로 11개 세포주의 telomerase 활성도를 TRAP assay와 real-time TRAP assay로 분석한 결과, r2=0.843 (p=0.001)으로 두 실험법 사이에 높은 상관관계를 보였다.
이러한 결과를 바탕으로 세포병리검사를 시행한 암환자 40명의 체액 164 검체를 이용하여 TRAP assay와 real-time TRAP assay 결과를 비교하였을 경우, 세포병리검사의 양성률은 4.9% (8/164)이며 TRAP assay에서 양성률은 4.3% (7/164), real-time TRAP assay에서는 25% (41/164)의 양성률을 나타냈다.
본 결과에서 real-time TRAP assay는 번거로운 전기영동 과정이 생략되고 실시간으로 telomerase 활성도를 정량 할 수 있는 대량 검사 (high-throughput)가 가능한 검사법으로 체액 내 유리된 암세포를 검사하는데 있어 기존의 TRAP assay를 대체할 수 있는 민감도 높은 검사법임을 확인하였고 실제 임상응용의 가능성을 보여주었다.
The purpose of this study was to measure safety-awareness among elementary students, identify their safety-practices and actual status of accidents. The study was also done to acquire basic information on safety education to help students be more aware of safety, and more active in accident-prevention activities. A random sample was taken of 763 5th and 6th grade students in 4 different elementary schools in Seoul. The survey was done between March 25th and April 10th with 96.3% of the students replying. Of the 735 questionnaires collected, 684 were complete and were used in the analysis. SPSS was used to analyze the questionnaires. The results are summarized as follows.
First, the overall safety-awareness score was relatively high at 139.06 of a maximum of 164. and respondents were most conscious of the section on Home Safety. Awareness was higher in girls, 5th graders, those who lived in apartments, students who participated in class activities, those who showed better leaning proficiency, those who felt the necessity of safety education, and those who received frequent safety education from their parents.
Second, the safety-practices of the respondents was at the middle level with a mean score of 56.01 of a maximum of 80. The level of safety-practice was higher in students whose parents had higher education, students who were only children, introverted students, students who participated in class activities, those who showed recognizably better leaning proficiency, those who felt the necessity of safety education, and those who received frequent safety education from their parents. The factors affecting the safety-practice of the respondents were education of their parents, number of siblings, respondent''s characteristics, adaptiveness to school life, recognized learning proficiency, awareness of need for safety education, and level of safety-education conducted by parents.
Third, 53.4% of the respondents had experienced one or more accidents during the past year. Most of the accidents occurred during play and recreation and Home accidents were the most frequently reported accidents. accidents was higher in boys than girls, those who have more friends, those who showed recognizably lower leaning proficiency. The risk factors related to the occurrence of accidents were gender, relationship with friends, recognized learning proficiency, and awareness of traffic safety.
Forth, higher safety-awareness was found to be directly related to higher safety-practices. Respondents with lower safety-awareness reported higher rate of accidents. With regard to safety-practice, the relationship was not statistically significant even though respondents with lower safety-practices reported more accidents.
In view of the results so far achieved, habituation and formation of safety-oriented actions among students are highly required to prevent accidents. In order to do that, development of safety-awareness and in-life enforcement of safety-practice need to come first. In schools, customized school safety training programs should be included in the regular curriculum and be enforced consistently and systematically.
Especially nursing teachers and class teachers should be able to fully utilize the allotted time to carry out the safety programs focused upon habituation of safety-practice, in an effort to make the students themselves lower the chances of accidents.
Additionally, a variety of safety methods and other effective programs targeted to students and parents should be developed and enforced to ensure practical implementation of the programs in which families, schools, and local community can actively cooperate and participate.