7, 12-dimethylbenzanthracene으로 유발된 생쥐표피의 증식성 변화와 Langerhans세포수의 변동

Abstract

[한글]

화학발암제에 의한 피부표피의 발암현상은 개시(initiation)와 촉진(promotion)의 2단계를 거친다. 종양개시제는 DNA를 손상 혹은 변형시켜 유전자의 변화를 일으키나 일회 투여로는 종양형성이 안되며, 종양촉진제를 투여하면 손상 혹은 변형된 세포의 선택적 증식

을 일으켜 종양이 형성된다. 피부의 Langerhans세포는 접촉성 알레르기 항원을 선택적으로 포착, 항원을 표현(presentation)하여 세포매개성 면역이 일어나도록 하므로 피부의 면역방어기능에 필수 불가결한 세포이다. 잠재성 종양세포의 형성과 암으로의 진행은 인

체의 다른 부위에서와 마찬가지로 면역학적 감시(surveillance)하에 있으며 피부 면역방어기능의 중요한 요소인 Langerhans세포와도 관계가 있을 것으로 생각할 수 있다.

본 연구에서는 발암제인 7, 12-dimethylbenzanthracene(DMBA)을 BALE/c 생쥐피부에 전처치한 후 종양촉진제인 12-0-tetradecanoyl-phorbol-13-acetate(TPA)를 단기 및 장기 도포하여 표피세포의 형태학적 변화에 따른 표피세포의 세포주기분포와 DNA ploidy 및 이러

한 세포의 증식결과와 표피내 Langerhans세포의 수적 변화에 대하여 관찰하여 다음과 같은 결론을 얻었다.

1. DMBA 전처치 후 TPA를 도포한 결과 유두종은 12주 이상 도포한 군에서 발생하였고 편평상피세포암종은 33주 이상 약물을 도포한 군에서 발생되었다. 유두종의 수 및 크기는 약물도포기간에 비례하여 증가되었다.

2. 표피세포의 증식, 과다각화증 및 이형성은 약물도포기간이 길수록 중가되었다.

3. 표피세포의 BrdU표지지수는 약물도포기간에 따라 증가되는 경향을 보였는데 12주 도포군과 21주 도포군 사이의 차이가 뚜렷하였다.

4. Langerhans세포지수는 약물도포기간이 길어짐에 따라 점점 감소하는 경향을 보였다.

특히 약물도포 초기인 4주 도포군에서 급격히 감소하였으며, 암종에서는 Langerhans세포가 전혀 관찰되지 않았다.

5. 표피세포의 BrdU표지지수가 증가될수록 Langerhans세포지수는 감소하였다.

6. 유세포측정 검색상 aneuploidy는 1예도 발생되지 않았으며 모든 예가 diploidy였다.

증식지수와 S기 분획은 약물도포기간에 따라 증가하였다.

이상의 결과로 보아 표피에 화학성 발암물질을 도포하면 Langerhans세포는 약물도포 초기에 급격히 감소하고, 세포증식능력은 상당한 시간이 지난 후에 중가되며, 증식력 및 이형성 변화가 현저히 증가된 경우에도 종양세포 DNA의 양적 이상은 발생되지 않음을 알 수

있었다.

The epidermal proliferation and the number of Langerhans cells in 7,

12-dimethylbenzanthracene induced epidermal changes

Chang Soon Han

Department of Medical Science The Graduate School, Yonsei University

(Directed by professor In Joon Choi and Kwang Gil Lee)

Chemically induced epiderml carcinogenesis is usually divided into two stages,

the initiation and promotion. The initiation involves conversion of some epidermal

cells into latent neoplastic cells and the promotion is proliferation of the

transformed cells. As immunosurveillence is thought to be a host defense against

tumors, Langerhans cells, being essential in initiation of local cutaneous

immunologic reaction, is suggested to be important in the carcingenesis of the

epidermis. This study is attempted to investigate the epidermal proliferative

changes in mice induced by application of

12-0-tetradecanoyl-phorbol-13-acetate(TPA) on the skin initiated with 7,

12-dimethyl-benzanthracene (DMBA) and its relationship with Langerhans cell.

Ninty four male inbred BALB/c mice weighing 20∼25g were divided into five

groups; the 33 week-group, the 21 week-group, the 12 week-group, and the

4week-group according to the duration of carcinogen application, and the control

group. The carcingen was applied with a brush on the dorsal skin of mice after

depilation. Ten days after application of 800 nmole DMBA in 0.4㏄ acetone, 20 nmole

TPA in 0.4㏄ acetone was applied twice per week and the control group was applied

with the same amount of acetone for 4week. Animals were sacrificed 3days after the

last application of TPA. One hour before sacrifice, bromodeoxyuridine(BrdU)(1 ㎎/g)

was injected via the tail vein for BrdU stain of S phase cells. A strip of dorsal

skin was used for hematoxy-lin-eosin stain, immunohistochemical stain for BrdU and

la antigen of Langerhans cell, and flow cytometry.

The results are as follows: 1. Celluar proliferation, hyperkeratosis and

dysplasia of the epidermis were increased in relation to duration of carcingen

application. Papillomas were developed 12weeks after application of the carcinogen.

2. BrdU labelling and proliferative indices of the 20 weeks' application group were

significantly higher than those of the 12 weeks' application group. The number of

Langerhans cell was decreased markedly after 4 weeks' application of the

carcinogen. 3. All epidermal lesions including a case of squamous cell carcinoma

were diploidy in flow cytometry. These results indicate that the number of

Langerhans cells decreases markedly in the early stave of chemically induced

epidermal carcinogenesis, but proliferation of epidermal cells increases much

later. Although abnormal quantitative chance of nuclear DNA has not occurred even

when the epidermal proliferative activity and dysplastic change were increased

markedly, it is thought that the occurrence of structural change of chromosome is

remained to be clarified.

[영문]

Chemically induced epiderml carcinogenesis is usually divided into two stages, the initiation and promotion. The initiation involves conversion of some epidermal cells into latent neoplastic cells and the promotion is proliferation of the

transformed cells. As immunosurveillence is thought to be a host defense against tumors, Langerhans cells, being essential in initiation of local cutaneous immunologic reaction, is suggested to be important in the carcingenesis of the epidermis. This study is attempted to investigate the epidermal proliferative changes in mice induced by application of 12-0-tetradecanoyl-phorbol-13-acetate(TPA) on the skin initiated with 7, 12-dimethyl- benzanthracene (DMBA) and its relationship with Langerhans cell.

Ninty four male inbred BALB/c mice weighing 20∼25g were divided into five groups; the 33 week-group, the 21 week-group, the 12 week-group, and the 4week-group according to the duration of carcinogen application, and the control group. The carcingen was applied with a brush on the dorsal skin of mice after depilation. Ten days after application of 800 nmole DMBA in 0.4㏄ acetone, 20 nmole TPA in 0.4㏄ acetone was applied twice per week and the control group was applied with the same amount of acetone for 4week. Animals were sacrificed 3days after the last application of TPA. One hour before sacrifice, bromodeoxyuridine(BrdU)(1 ㎎/g) was injected via the tail vein for BrdU stain of S phase cells. A strip of dorsal skin was used for hematoxy-lin-eosin stain, immunohistochemical stain for BrdU and la antigen of Langerhans cell, and flow cytometry.

The results are as follows: 1. Celluar proliferation, hyperkeratosis and dysplasia of the epidermis were increased in relation to duration of carcingen application. Papillomas were developed 12weeks after application of the carcinogen.

2. BrdU labelling and proliferative indices of the 20 weeks' application group were significantly higher than those of the 12 weeks' application group. The number of Langerhans cell was decreased markedly after 4 weeks' application of the carcinogen. 3. All epidermal lesions including a case of squamous cell carcinoma were diploidy in flow cytometry. These results indicate that the number of Langerhans cells decreases markedly in the early stave of chemically induced epidermal carcinogenesis, but proliferation of epidermal cells increases much later. Although abnormal quantitative chance of nuclear DNA has not occurred even

when the epidermal proliferative activity and dysplastic change were increased markedly, it is thought that the occurrence of structural change of chromosome is remained to be clarified.