Opioid Receptor Antibodies Trifecta

This publication proposes a role for opioid receptors in treating cancers. It also references use of our μ, δ, and κ opioid receptor antibodies.

Kohei Yamamizu1, Sadayoshi Furuta, Shiori Katayama, Michiko Narita, Naoko Kuzumaki, Satoshi Imai, Hiroshi Nagase, Tsutomu Suzuki, Minoru Narita, and Jun K. Yamashita. The κ opioid system regulates endothelial cell differentiation and pathfinding in vascular development. Blood July 21, 2011 vol. 118 no. 3 775-785.

Highlights: The opioid system is, thus, a new regulator of vascular development that simultaneously modifies 2 distinct vascular properties, EC differentiation and vascular pathfinding. We confirmed that KOR, but not MOR, was highly expressed in various ECs such as HUVECs (data not shown), suggesting that KOR agonists could directly act on tumor ECs to suppress VEGF receptor expression, similar to the effects observed in embryonic ECs. If so, a combination therapy including an MOR agonist, morphine, and a KOR agonist (such as TRK820, a clinically approved drug in Japan for uremic pruritus) may prove useful for cancer therapy through the suppression of tumor angiogenesis by dual inhibition of VEGF ligands and receptors, extending the therapeutic benefits beyond pain relief.

Images: KOR was highly expressed in Flk1⁺ vascular progenitors. (A) RT-PCR showing mRNA expression of MOR, DOR, and KOR in ES cells, Flk1⁺ cells, cells after 1 or 3 days of Flk1⁺ cell culture (Flk-d1 or Flk-d3), CD31-positive cells (ECs) and CD31-negative cells (MCs) at Flk-d3. (B) Fluorescent staining for MOR, DOR, and KOR at Flk-d1. Nuclei are stained with DAPI (blue). Left, MOR; middle, DOR; right, KOR. Scale bars, 100 μm. (C) Double fluorescent staining for MOR, DOR, and KOR with CD31 (red) at Flk-d3. Nuclei are stained with DAPI (blue). Top, opioid (green) receptors (green); middle, CD31 (red); bottom, merged. Scale bars, 100 μm.