Combination immunotherapy targeting for chemoresistnat cancer stem cells with PD-L1 expression

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K19927
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Digestive surgery
• Research Institution: Osaka University
• Principal Investigator: URAKAWA SHINYA 大阪大学, 医学部附属病院, 医員 (40768975)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 食道癌 / 癌幹細胞 / PD-L1 / 抗腫瘍免疫回避機構

Outline of Final Research Achievements

Although immunohistochemistry showed tumorous PD-L1 expression was associated with poor overall survival in esophageal cancer patients who underwent esophagectomy, no relationship was identified between PD-L1 expression and presence of preoperative therapy or tumor response. In flow cytometry analysis of tissue-infiltrating lymphocytes extracted from pre-therapeutic biopsy tissue and resected specimen, percentage of positive PD-1 in CD8+ cells was higher in non-responders compared with responders while some cases showed increased PD-1-expression after chemotherapy, thus indicating that PD-L1/PD-1 pathways was associated with chemoresistance in esophageal cancer. Now, we are analyzing PD-L1 expression in pre-therapeutic biopsy tissue by immunohistochemistry and establishing a new method to culture tumor tissue together with immune cells　to investigate the mechanism of cancer stem cells with PD-L1-expression resistant to chemotherapy.

Free Research Field

がん免疫