The role of LIM homeodomain transcription factor ISL-1 in leukemogenesis in ATL

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K18414
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Tumor biology
• Research Institution: University of the Ryukyus
• Principal Investigator: ISHIKAWA Chie 琉球大学, 亜熱帯島嶼科学超域研究推進機構, 助教 (90542358)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 成人T細胞白血病（ATL） / HTLV-1 / ISL-1 / Tax / c-myc

Outline of Final Research Achievements

HTLV-1 is the etiological agent of adult T-cell leukemia (ATL). Although the viral protein Tax plays crucial roles for the development of ATL, the underlying mechanisms remain obscure. ISL-1, LIM homeodomain transcription factor, is specifically expressed in certain tissue types only. Recently, ISL-1 is suggested to play an oncogenic role. The expression of ISL-1 was assessed in 8 HTLV-1-infected T-cell lines and 3 uninfected T-cell lines. RT-PCR results demonstrated a marked highly expression of ISL-1 mRNA in 5 HTLV-1-infected T-cell lines. The expression levels of ISL-1 mRNA were associated with those of Tax mRNA. ISL-1 protein was also detected in 3 Tax-positive HTLV-1-infected T-cell lines. HTLV-1 infection and Tax overexpression induced the expression of ISL-1 in T cells. Notably, ISL-1 overexpression promoted T-cell proliferation. Furthermore, ISL-1 activated the expression of c-myc. Our results provide insights into the new relationships between ISL-1 and HTLV-1 oncogenesis.

Free Research Field

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