The Small Heal Shock Protein αA-Crystallin Is Expressed In Pancreas and Acts as Negative Regulator of Carcinogenesis

Mi Deng (1) , Pei-Chao Chen (2) , Sisi Xie (2) , Junqiong Zhao (2) , Lili Gong (1) , Jinping Liu (1) , Lan Zhang (1, 2) , Shuming Sun (1, 2) , Jiao Liu (2, 1) , Haili Ma (1) , Surinder Batra (1) , David Wan-Cheng Li (1, 2, 3)

1 Department of Biochemistry and Molecular Biology
2 HNU - Hunan Normal University
3 Department of Ophthalmology & Visual Sciences

The small heat shock protein αA-crystallin is a structural protein in the ocular lens. In addition, recent studies have also revealed that it is a molecular chaperone, an autokinase and a strong anti-apoptotic regulator. Besides its lenticular distribution, a previous study demonstrates that a detectable level of αA-crystallin is found in other tissues including thymus and spleen. In the present study, we have re-examined the distribution of αA-crystallin in various normal human and mouse tissues and found that the normal pancreas expresses a moderate level of αA-crystallin. Moreover, αA-crystallin is found significantly downregulated in 60 cases of pancreatic carcinoma of different types than it is in 11 normal human pancreas samples. In addition, we demonstrate that αA-crystallin can enhance activity of the activating protein-1 (AP-1) through modulating the function of the MAP kinase, and also up-regulates components of TGFβ pathway. Finally, expression of αA-crystallin in a pancreatic cancer cell line, miapaca, results in retarded cell migration. Together, these results suggest that αA-crystallin seems to negatively regulate pancreatic carcinogenesis.

Mots clés: Small heat shock protein; αA; Pancreas; AP-1; Smad2/3/5; TGFβ; Pancreatic Cancer; Cell migration

Mi Deng, Pei-Chao Chen, Sisi Xie, Junqiong Zhao, Lili Gong, et al.. The Small Heal Shock Protein αA-Crystallin Is Expressed In Pancreas and Acts as Negative Regulator of Carcinogenesis. Biochimica et Biophysica Acta - Molecular Basis of Disease, 2010, 1802 (7-8), pp.621. ⟨10.1016/j.bbadis.2010.04.004⟩. ⟨hal-00600124⟩