Abstract:

Objective To investigate the role of Hippo/Yes related protein（YAP） signaling pathway regulation protein aggrecan（ACAN）in the diagnosis of hepatocellular carcinoma （HCC）. Methods A total of 156 HCC patients,33 hepatitis B patients,31 hepatitis C patients,30 liver cirrhosis patients,26 colon cancer patients,19 lung cancer patients,22 gastric cancer patients,20 breast cancer patients and 100 healthy subjects （healthy control group） were enrolled. Their ACAN levels were determined. YAP over-expressive vector and YAP-shRNA lentivirus plasmid were used to transfect hepatoma cell lines Bel-7402 and SMMC-7721. Over-expressive cAMP-response element binding protein （CREB）,TEA domain family member（TEAD）,alpha-globin transcription factor CP2（TFCP2）,Runt-related transcription factor 2 （RUNX2）vectors were individually transfected and co-transfected with YAP into Bel-7402 and SMMC-7721 cells,respectively. The expression of ACAN mRNA and the effects of different vectors on ACAN wild and mutant type promoters were determined. The diagnostic efficiency of ACAN and alpha-fetoprotein（AFP） for the diagnosis of HCC was evaluated. Results The levels of ACAN in HCC group were higher than those in gastric cancer,colon cancer,breast cancer,lung cancer,hepatitis B,hepatitis C and healthy control groups （P=0.000）,but there was no statistical significance among the other groups （P>0.05）. The expression of ACAN mRNA increased after the over-expression of YAP（P<0.01）,but it decreased after YAP knockout （P<0.01）. Compared with other transcription factors （TEAD,TFCP2 and RUNX2）,over-expressive CREB and co-transfected CREB and YAP could promote the expression of ACAN mRNA （P<0.01）. The wild type ACAN promoter can be affected by CREB and YAP,while the mutant type ACAN promoter was not affected. There was a positive correlation between ACAN and AFP,alanine aminotransferase （ALT）and aspartate aminotransferase （AST）（r=0.722,0.517 and 0.443,P=0.000）. Receiver operating characteristic （ROC） curve showed that the areas under the curves （AUC）of ACAN and AFP were 0.978 and 0.661. The AUC of ACAN were 0.903 and 0.993 for the diagnosis of stage Ⅰ-Ⅱ and stage Ⅲ HCC,respectively. Conclusions The diagnostic efficiency of ACAN for HCC is better than that of AFP. The diagnostic efficiency for advanced HCC is superior to that of early HCC. ACAN can be used as a new tumor marker for the diagnosis of HCC and plays a role through Hippo/YAP signaling pathway.

Key words: Aggrecan, Hepatocellular carcinoma, Hippo/ Yes related protein signaling pathway