ヒト胃癌腹膜播種形成におけるケモカインとそのレセプター発現の臨床的意義

ヒト胃癌の腹膜播種形成におけるケモカインの関与ならびにその役割を明らかにするために、1、ヒト胃癌継代細胞株数種を用いてケモカインレセプターの発現をRT-PCR法免疫細胞染色法を用いて検討した。腹膜播種指向性細胞株において選択的にCXCR4レセプターを高発現していることが判明した。CXCR4高発現胃癌細胞株を用いてその唯一のリガンドであるCXCL12(SDF-1a)に対する生物活性(遊走能・増殖能)の有無を検討した。リガンドの添加刺激に対し遊走能ばかりでなく増殖能をも有することが判明した。それら活性に対し、CXCR4のモノクローナル抗体投与は、生物活性を有意に抑制した.さらに、細胞内のSurvival signalsとして知られるAktならびにERKのリン酸化をも誘導することがウエスタンブロット法にて判明した。3、ヒト臨床検体を用いた検討では、腹膜播種症例と肝転移症例の進行再発胃癌症例の胃原発巣におけるCXCR4の発現を比較検討した結果、癌性腹膜炎を発症した症例群の原発巣では、肝転移を発症した症例群に比して有意差をもってCXCR4の発現が亢進していた。また、転移の臓器選択性を検討する目的で胃癌転移の好発臓器である肝臓・腹膜・リンパ節・胃粘膜におけるCXCL12(SDF-1a)の発現をRT-PCR法と免疫組織染色法を用いて検討した結果、大変興味深いことに、腹膜組織において恒常的なCXCL12(SDF-1a)の高発現が確認され、さらに癌性腹水中には高濃度のCXCL12(SDF-1a)が存在することが判明した。4、今後の臨床治療への応用を図ることを目的に、まずCXCR4を高発現するヒト胃癌細胞株をヌードマウス腹腔内に移植し、腹膜播種モデルを作製した。この系にCXCR4阻害剤(AMD3100)を腹腔内投与し、癌性腹水生成の有意な抑制と、腹膜転移結節の明らかな縮小を確認した。臨床的に胃癌腹膜播種再発を起こしやすい低分化腺癌や印環細胞癌は、選択的にCXCR4レセプターを高発現し、腹膜に高発現する唯一のリガンドCXCL12(SDF-1a)を介して腹腔内に遊走、腹膜上で増殖し、癌性腹水成立とともに腹水内においても増殖し、腹膜播種を形成・進展させていくことが強く示唆された。CXCR4レセプター阻害剤の腹腔内投与による腹膜播種抑制は、予防薬の開発という新たな分子標的治療として新しい治療コンセプトとなりうる可能性がある。Peritoneal carcinomatosis is a frequent cause of death in patients with advanced gastric carcinoma. Since chemokines are now considered to play an important role in the metastasis of various malignancies, we hypothesized that they may also be involved in the development of peritoneal carcinomatosis by gastric carcinoma. Human gastric carcinoma cell lines, which were all highly efficient in generating malignant ascites in nude mice upon intraperitoneal inoculation, selectively expressed CXCR4 mRNA and protein. In particular, NUGC4 cells showed vigorous migratory responses to its ligand CXCL12 (also called stromal-derived factor-1a, SDF-1a). CXCL12 enhanced proliferation and rapid increases in phosphorylation of protein kinase B/Akt and extracellular signal-regulated kinase (ERK) of NUGC4 cells. We also demonstrated that AMD3100 (a specific CXCR4 antagonist) effectively reduced tumor growth and ascitic fluid formation in nude mice inoculated with NUGC4 cells. In addition, we examined human clinical samples. Malignant ascites fluids from patients with peritoneal carcinomatosis contained high concentrations of CXCL12 (average, 4.67 ng/mL). Moreover, immunohistochemical analysis demonstrated that 22 of 33 primary gastric tumors with peritoneal metastasis were positive for CXCR4 expression (67%), whereas only 4 of 16 with other distant metastasis were positive (25%). Notably, 22 of 26 CXCR4-expressing primary tumors developed peritoneal metastases (85%). CXCR4-positivity of primary gastric carcinomas significantly correlated with the development of peritoneal carcinomatosis. Collectively, our results strongly suggest that the CXCR4/CXC12 axis plays an important role in the development of peritoneal carcinomatosis from gastric carcinoma. Thus, CXCR4 may be a potential therapeutic target for peritoneal carcinomatosis of gastric carcinoma.研究課題/領域番号:16591303, 研究期間(年度):2004-2005出典：「ヒト胃癌腹膜播種形成におけるケモカインとそのレセプター発現の臨床的意義」研究成果報告書　課題番号16591303 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)　　　本文データは著者版報告書より作

Tumor necrosis factor αとInterferon γによるヒト胃癌細胞株における相乗的インタ-ロイキン8産生誘導機序の分子生物学的解析

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1084号, 学位授与年月日：平成5年3月25日,学位授与年：199

Inhibition of GSK-3β activity attenuates proliferation of human colon cancer cells in rodents

The authors\u27 recent discovery that glycogen synthase kinase-3β (GSK-3β) participates in colon cancer cells\u27 survival and proliferation prompted us to investigate whether GSK-3β inhibition alters proliferation of colon cancer cells in vivo. Groups of four or five athymic mice (Balb/c, nu/nu) with subcutaneous xenografts of SW480 human colon cancer cells were treated with dimethyl sulfoxide (DMSO) or different doses (1, 2 and 5mg/kg body weight) of either small-molecule GSK-3β inhibitor (SB-216763 and AR-A014418) by intraperitoneal injection three times per week for 5 weeks. Compared with DMSO (a diluent of the GSK-3β inhibitors) as a control, either GSK-3β inhibitor significantly inhibited proliferation of cancer cell xenografts in the rodents in a dose-dependent manner. Histochemical and immunohistochemical analysis of tumor xenografts demonstrated a significant, dose-dependent decrease in fractions of proliferating cells and an increase in the incidence of apoptosis of cancer cells in mice treated with either GSK-3β inhibitor. No adverse events or effects were observed in the rodents during the course of treatment, except for rare lethal accidents due to intraperitoneal injection. Morphological examination showed no apparent pathologic changes in major organs including the lungs, liver, pancreas, kidneys, spleen and large bowel of rodents treated with DMSO and the GSK-3β inhibitors. The results indicate that the GSK-3β inhibitors would be a novel class of therapeutic agent for colon cancer. © 2007 Japanese Cancer Association

Combined chemotherapy with carboplatin plus irinotecan showed favorable efficacy in a patient with relapsed small cell carcinoma of the prostate complicated with meningeal carcinomatosis

金沢大学附属病院がん高度先進治療センター金沢大学がん研究所分子標的がん医療研究開発センターWe report the case of a 65-year-old man with recurrent prostate cancer who presented with meningeal carcinomatosis. In September 2007, he had been diagnosed with mixed type small cell carcinoma and adenocarcinoma at clinical stage T4N1M1 (primary prostate tumor with multiple bone, liver, and lymph node metastases) and hormonal therapy had been administered. Following an increase in the level of pro-gastrin-releasing peptide (ProGRP), combined chemotherapy with cisplatin plus etoposide was implemented and showed efficacy in targeting the small cell carcinoma. In March 2008, he presented with signs of meningeal irritation; his condition deteriorated quickly and multiple brain metastases were confirmed by magnetic resonance imaging (MRI). A sample of cerebrospinal fluid collected by lumbar puncture showed cancer cells and an elevated level of ProGRP. Small cell carcinoma of the prostate complicated with meningeal carcinomatosis was diagnosed. A different chemotherapy regimen was then administered, consisting of a combination of carboplatin plus irinotecan, which is one of the most common first-line treatments for extensive-stage small cell lung carcinoma. From day 20 after the initiation of this therapy, he gradually recovered from the signs of meningeal irritation, and brain MRI showed nearly normal findings; also, the serum level of ProGRP was reduced. In conclusion, we report the efficacy of combined treatment with carboplatin plus irinotecan for small cell carcinoma of the prostate complicated with meningeal carcinomatosis. Because this clinical condition is extremely rare, a gold standard treatment has yet to be established. © 2009 Japan Society of Clinical Oncology