위암환자에서 수술전 Polyadenylic-polyuridylic Acid 투여가 말초혈액과 영역림프절 단핵구의 NK 및 LAK활성도에 미치는 영향

Abstract

[한글]

Polyadenylic-polyuridylic acid[Poly(A)·Poly(U)]는 비독성, 합성 double-stranded polynucleotide로서 세포성 및 체액성 면역조절기능을 갖고 있는데 절제 가능한 유방암과 위암에서 근치적 수술후 보조적 치료제로서 효과가 높음이 최근에 보고되었고, 이러한 항암효과는 주로 인터페론유도에 따른 말초혈액 단핵구(peripheral blood mononuclear cell ; PBMC)의 NK활성도(natural killer activity) 상승에 의한 것으로 알려져 있다. 그러나 poly(A)·poly(U) 투여가 암주위 영역림프절 단핵구(lymphnode mononuclear cell; LNMC)의 NK 및 LAK활성도 (lymphokine-activated hiller activity)와 인터페론작용과 관련되는 2', 5'-AS활성도(2', 5'-oligoadenylate synthetase activity)에 미치는 영향에 대하여서는 아직까지 보고된 바 없다.

이에 본 연구에서는 위암환자에 있어서 수술전 poly(A)·poly(U) 투여가 PBMC와 LNMC의 NK 및 LAK활성도와 2', 5'-AS활성도에 미치는 영향을 알아보기 위하여 47예의 위암환자를 두군으로 나누어 26예의 poly(A)·poly(U) 비투여군에게는 수술 2일전 placebo를, 21예의 poly(A)·poly(U) 투여군에게는 수술 6일, 4일 및 2일전의 3회에 걸쳐 각각 100mg의 poly(A)·poly(U)를 정맥주사하고, 약물투여전과 수술시 얻은 PBMC와 위암주위 영역림프절에서 분리한 LNMC의 NK 및 LAK활성도를 K562와 Raji세포를 표적세포로하여 4시간 51**Cr방출법으로 측정하였으며, 2', 5-AS활성도를 3**H-ATP 존재하에서 2', 5'-oligoadenylate[pppA(2'p5'A)n; 2', 5'-A)를 합성하는 능력으로 측정하여 다음의 결과를 얻었다.

1. 위암환자에 있어서 LNMC의 NK 및 LAK활성도는 PBMC의 NK 및 LAK활성도에 비하여 매우 낮았다.

2. 위암의 진행정도에 따라 PBMC의 NK 및 LAK활성도는 낮아졌으나 LNMC의 NK 및 LAK활성도는 암의 진행정도나 림프절의 전이여부에 따른 차이가 없었다.

3. LNMC의 2', 5'-AS활성도는 PBMC의 2', 5'-AS활성도 보다 다소 높았다.

4. 위암의 진행정도에 따라 PBMC의 2', 5'-AS활성도는 감소하는 경향을 보였으나 LNMC의 2', 5'-AS활성도는 증가하는 경향을 보였다.

5. Poly(A)·poly(U) 투여후 PBMC의 NK 및 LAK활성도는 증가하였으나 LNMC의 NK 및 LAK 활성도는 증가하지 않았다.

6. Poly(A)·poly(U) 투여후 PBMC와 LNMC의 2', 5'-AS활성도는 증가하는 경향을 보였다.

이상의 결과로 위암환자에서 LNMC의 NK 및 LAK활성도는 PBMC 보다 낮으나 인터페론작용과 관련되는 2', 5'-AS활성도는 암이 진행된 경우라 할지라도 높게 유지됨을 알 수 있었고, poly(A)·poly(U)를 투여하면 PBMC의 NK 및 LAK활성도를 증가시킬 뿐 아니라 PBMC와 LNMC의 2', 5'-AS활성도도 증가시키므로 위암환자에 있어서 poly(A)·poly(U)의 투여가 항암효과를 높이는데 기여할 수 있을 것으로 생각된다.

[영문]

Although the biological significance of the regional lymphnode as a barrier to tumor remains unclear, the clinical prognostic relevance of the neoplastic infiltration of these nodes is accepted. The most potent antitumor effector cells may be expected to be present within or around the site of tumor growth However, lymphocytes isolated from solid tumor, cancer ascites fluid, and carcinomatous pleural effusion have been shown to express low natural killer(NK) activity or none at all. Similarly, it has been reported that lymphnode can be regarded as an NK-deficient tissue, since more limited cytotoxic activity is recorded in the

lymphnode cells.

Although there is general agreement that the NK and lymphokine-activated killer(LAK) activities of peripheral blood mononuclear cells(PBMC) decrease in patients with various tumors, this decrease remains unclear with regard to the cytotoxic activities of their regional lymphnode mononuclear cells(LNMC), especially after in vitro stimulation by lymphokines or after in vivo administration of biological response modifier(BRM).

Polyadenylic-polyuridylic acid[poly(A)·poly(U)], a nontoxic double-stranded complex of synthetic polyribonucleotides has been successfully rosed as an adjunt to surgery in animal tumors as well as operable human breast and gastric cancers.

The mechanisms governing the antitumor action of poly(A)·poly(U) has been discussed with respect to various biological effects such as immunomodulation for both humoral and cell-mediated immune responses, induction of interferon, and enhancement of NK cell activity. However, detection of serum interferon induced by poly(A)-poly(U) is very difficult, because low dose of poly(A)·poly(U) lead to not sufficient production of detectable levels of interferon and half-life of circulating interferon is very short. Under these conditions, the interferon-mediated enzymes[2', 5'-oligoadenylate synthetase(2', 5'-AS) and p67k kinase] are enhanced, and the degree of enhancement is correlated with the dose of poly(A)·poly(U). Therefore, these enzymes may be used as convenient markers to monitor the interferon-inducing effect of poly(A)·poly(U).

It is of interest to assess whether the in vitro administration of poly(A)·poly(U) auguments the NK and LAK activities and 2', 5'-AS activity of PBMC and LNMC. So, the present study was designed to investigate the effects of the in vivo administration of poly(A)·poly(U) on the NK and LAK activities and 2', 5'-AS activities of PBMC and LNMC from patients with gastric carcinoma.

Fourtyseven patients with resectable gastric carcinoma were divided into poly(A)·poly(U)-nontreated group(21 patients) and poly(A)·poly(U)-treated group(26 patients) to whom 100 mg of poly(A)·poly(U) was intravenously administerded 3 times preoperatively. NK and LAK activities of PBMC and LNMC were measured by 4 hour 51**Cr-release assay using K562 and Raji cells as targets and 2', 5'-AS activities were measured by measuring 2', 5'-A produced by 2', 5'-AS attached to polyinosinic-polycytidilic acid agarose bead.

The results obtained are as follows:

1. NK and LAK activities of LNMC were significantly lower than those of PBMC from patients with gastric carcinoma.

2. As the stage of gastric carcinoma progressed, NK and LAK activities of PBMC decreased but those of LNMC did not. No differences were found in NK and LAK activities of LNMC, whether regional lymphnodes were infiltrated or net by the carcinoma.

3. 2', 5'-AS activities of LNMC were slightly higher than those of PBMC.

4. 2', 5'-AS activities of PBMC showed decreasing tendency and those of LNMC showed increasing tendency according to the stave of gastric carcinoma.

5. After administration of poly(A)·poly(U), NK and LAK activities of PBMC increased but those of LNMC did not increase.

6. After administration of poly(A)·poly(U), 2', 5'-AS activities of PBMC and LNMC showed increasing tendency.

These results suggest that even though NK and LAK activities of LNMC were significantly lower than those of PBMC, 2', 5'-AS activitiy of LNMC were maintained in high level even in patients with gastric carcinoma. And anti-cancer effect of poly(A)·poly(U) in patients with gastric carcinoma may be related with augumented 2', 5'-AS activities of PBMC and LNMC as well as enhanced NK and LAK activities of PBMC after administration of poly(A)·poly(U).