Identification of microRNA that correctly inhibits KRAS-related downstream signal transduction in KRAS mutant colorectal cancer

• Project/Area Number: 24659608
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Digestive surgery
• Research Institution: Osaka University
• Principal Investigator: YAMAMOTO Hirofumi 大阪大学, 医学(系)研究科(研究院), 准教授 (30322184)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2013: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: KRAS / colorectal cancer / microRNA / RAF/MEK/ERK pathway / PI3K/Akt pathway / carbonate apatite / nanoparticle / AKT / 大腸癌 / K-ras遺伝子変異 / セツキシマブ / MAPK/ERK / AP-１

Research Abstract

The antiEGFR monoclonal antibodies are effective in patients with metastatic CRC with KRAS wild type. However, KRAS mutant mCRC shows resistance to the antiEGFR antibodies. To identify miRNAs that inhibit KRAS mutant CRCs, we first introduced KRASG12V cDNA into HEK293 and MRC5. After miRNA microarray analyses we searched which candidate miRNAs would inhibit two major KRAS-associated signal transduction pathways using SRE and AP1 luciferase reporter assays. And we found 2 miRNAs. miR-4689 regulated not only RAF/MEK/ERK pathway but also PI3K/Akt pathway by directly binding to both 3UTR of KRAS and the coding sequence of Akt1. Down-regulation of Akt1 led to sequential induction of pro-apoptotic factors and inhibition of anti-apoptotic molecules. Systemic administration of miR-4689 with super carbonate apatite nanoparticles in nude mice significantly inhibited the growth of pre-established DLD1 xenografts compared to miR-NC with a proof of down-regulation of KRAS and Akt1.

Research Products

• [Patent(Industrial Property Rights)] 大腸癌の治療剤 (2014)
  • Inventor(s): 山本浩文、森正樹、土岐祐一郎、西村潤一
  • Industrial Property Rights Holder: 山本浩文、森正樹、土岐祐一郎、西村潤一
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 2014-041768
  • Filing Date: 2014-03-04
• [Patent(Industrial Property Rights)] 大腸癌の治療剤 (2014)
  • Inventor(s): 山本浩文 森正樹 土岐祐一郎 西村潤一
  • Industrial Property Rights Holder: 山本浩文 森正樹 土岐祐一郎 西村潤一
  • Industrial Property Rights Type: 特許
  • Filing Date: 2014