MIA-602 (GHRH antagonist) is a new PAK1-blocking peptide!

Several years ago, a group led by Andrew Schally (1977 Nobel-laureate) at University of Miami developed a new peptide of 29 amino acids called MIA-602 which antagonizes with GHRH (growth-hormone releasing hormone) for its receptor, and found its potent anti-cancer activity (1). Very recently, a Chinese group in collaboration with Andrew Schally, nailed-down the precise molecular mechanism underlying its anti-cancer action. MIA-602 suppresses the PAK1 gene expression (2). Thus, MIA-602 is a new member of PAK1- blockers.

In other words, GHRH and its receptor are essential for activation of PAK1 gene, and if its receptor is abnormally activated somehow, a wide variety of PAK1-dependent diseases/disorders would emerge, and eventually shorten our lifespan. Interestingly, GH (growth-hormone)-deficient mice are dwarfs, but live longer than the wild-type (3). Thus, it is almost certain that MIA-602 extends our healthy lifespan. 

References: 
 1. Bellyei S¹, Schally AV, Zarandi M, Varga JL, Vidaurre I, Pozsgai E.

GHRH antagonists reduce the invasive and metastatic potential of human cancer cell lines in vitro. Cancer Lett. 2010 ; 293(1): 31-40.

2. Gan J¹, Ke X¹, Jiang J¹, Dong H¹, Yao Z¹, Lin Y¹, Lin W¹, Wu X², Yan S³, Zhuang Y², Chu WK⁴, Cai R^5,6,7,8,9, Zhang X^5,6,7,8,9, Cheung HS^5,6,10, Block NL¹¹, Pang CP^4,12, Schally AV^{13,6,7,8,9,11}, Zhang H^14,2,15. Growth hormone-releasing hormone receptor antagonists inhibit human gastric cancer through downregulation of PAK1-STAT3/NF-κB signaling. Proc Natl Acad Sci U S A. 2016 Dec 7.  

3. Kinney-Forshee BA¹, Kinney NE, Steger RW, Bartke A. Could a deficiency in growth hormone signaling be beneficial to the aging brain?  Physiol Behav. 2004; 80(5): 589-94.