Serum soluble interleukin-2 receptor and immunohistochemical staining of IL-2R/Tac antigen in gastric cancer

本研究旨在探讨血清可溶性白细胞介素2受体（sIL-2 R）在早期胃癌患者中的临床意义。215例胃癌患者入组本研究。血清可溶性IL-2 R水平用酶联免疫吸附试验测定。有淋巴结转移者sIL-2 R水平明显高于无淋巴结转移者。同时检测了74例早期胃癌患者血清sIL-2 R水平。6例有淋巴结转移者中5例血清sIL-2 R阳性，68例无淋巴结转移者中43例血清sIL-2 R阴性。取19例患者的组织，用鼠抗人白细胞介素2受体抗体进行免疫组化染色。19例胃癌组织中有13例IL-2 R阳性细胞。同样，在转移淋巴结的组织中识别IL-2 R阳性细胞。提示胃癌患者浸润的活化T淋巴细胞起抗肿瘤作用，并释放大量sIL-2 R，导致血清sIL-2 R水平升高。此外，我们可以在结直肠癌中获得与胃癌相同的结果。根据这些数据，T淋巴细胞在癌细胞释放的体液介质的刺激下，将成为活化的T淋巴细胞，从而导致胃肠道肿瘤的抗肿瘤作用。

In the present study, we investigated the clinical significance of serum sIL-2R in patients with early gastric cancer. 215 patients with gastric cancer were enrolled in this study. Levels of serum soluble IL-2R were measured by an enzyme-linked immunosorbent assay. The levels of sIL-2R in cases with metastatic lymph nodes were significantly higher than those without metastatic lymph nodes. Moreover, Levels of serum sIL-2R in 74 patients with early gastric cancer were measured. Five of these 6 cases with metastatic lymph nodes demonstrated positive levels of serum soluble IL-2R, while 43 of 68 cases without metastatic lymph nodes demonstrated negative levels of serum sIL-2R. In the tissues obtained from 19 cases, immunohistochemical staining was performed with mouse anti-human interleukin-2 receptor antibody. 13 of 19 cases showed Il-2R positive cells in gastric cancer tissues. Similarly, Il-2R positive cells were recognized in the tissues of metastatic lymph nodes. These results may suggest that activated T lymphocytes infiltrating into the cancer tissues play an atitumor role and release a large amount of sIL-2R, resulting the high levels of serum sIL-2R in patients with gastric cancer. Moreover, we could get the same results in colorectal cancer as in gastric cancer. According to these data, T-lymphocytes, stimulated by humoral mediator released from cancer cells, would become to be activated T-lymphocytes, resulting in the anti-tumor effects in gastrointestinal cancer.