胃癌細胞株 (低分化腺癌と高分化腺癌) に対する125Iの小線源療法 (hot) の増殖抑制効果が観察された。免疫染色、caspase-3の活性を調べたところ、小線源療法によるアポトーシス誘導が観察された。次に、in vivoでのhot群の安全性と増殖抑制効果を検討するため、ヌードマウスの胃癌播種モデルを構築し、アプリケーターにより腫瘍内部に小線源を投与した。cold群と比べ、hot群では優位に腫瘍量が少なく、2週間後には播種巣は、定常状態となった。胃癌細胞株全てにおいて腫瘍抑制効果が観察され、免疫染色により、hot群ではアポトーシスが誘導されたことが証明された。
Human gastric cancer cell lines (well-differentiated and poor-differentiated cancer) were treated with cold or hot seeds in vitro and in nude mouse injected by applicator. Cell viability, apoptosis, caspase-3 assay, and cell-cycle distribution were studied in vitro. Body weight and tumor volumes of nude mice with cancer cells subcutaneously injected were measured, and in vivo cell proliferation and apoptosis assays were also evaluated by Ki67 and TUNEL double staining. Hot seeds reduced cell viability and induced cell apoptosis through the activation of caspase-3, and resulted in the accumulation of cells in the G 2/M phase in vitro. It also suppressed the growth of gastric cancer xenografts in nude mice, while inhibiting cell proliferation and inducing apoptosis were demonstrated by proliferation assay or double staining. Thus, these results suggest that hot seeds, regardless of histological origin, might be a safe and promising new option as one of gastric cancer treatment.

研究種目 : 基盤研究 (C) (一般)
研究期間 : 2016～2018
課題番号 : 16K09290
研究分野 : 消化器病学