2013 Fiscal Year Final Research Report

Role of PTPRZ1 to maintain cancer stemness in small-cell lung carcinoma

Research Project

Project/Area Number	24700990
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Tumor biology
Research Institution	National Center of Neurology and Psychiatry
Principal Investigator	MAKINOSHIMA Hideki 独立行政法人国立がん研究センター, 臨床開発センター, 研究員 (30510573)
Project Period (FY)	2012-04-01 – 2014-03-31
Keywords	がん幹細胞 / チロシンフォスファターゼ / 肺小細胞がん / PTPRZ1
Research Abstract	Because small-cell lung carcinoma (SCLC) is still a disease with a poor prognosis and limited treatment options, there is an urgent need to develop targeted molecular agents for this diseases. We screened cell lines and paraffin-embedded tissues from a variety of pathological phenotypes to examine PTPRZ1 expression. Here we show that PTPRZ1 is highly expressed in SCLC cell lines and exists in human SCLC tissues. In addition, we found that PTPRZ1 actually has an important oncogenic role in tumor progression in the murine xenograft model. These results imply that PTPRZ1 could be a feasible cell-surface marker to isolate cancer stem cells of SCLC.To test this idea, we established to separate PTPRZ1 positive cells (PTPRZ1+) from PTPRZ1 negative cells (PTPRZ1-) using anti-PTPRZ1 antibody. However, isolated SCLC cells were technically impossible to maintain cell culture in vitro. Therefore, we could not characterize whether PTPRZ1+ cells might have a feature of cancer stem cells.