Z Gastroenterol 2017; 55(08): e57-e299
DOI: 10.1055/s-0037-1605128
Kurzvorträge
Gastroenterologische Onkologie
Grundlagen: HCC und CCC: Donnerstag, 14 September 2017, 09:30 – 10:58, St. Petersburg/Forschungsforum 1
Georg Thieme Verlag KG Stuttgart · New York

Inhibition of glyoxalase-I leads to decreased proliferation and migration of high proliferative HCC tumor cell lines

M Michel
1   Martin-Luther-Universität Halle (Saale), Innere Medizin I, Halle, Deutschland
,
M Hollenbach
1   Martin-Luther-Universität Halle (Saale), Innere Medizin I, Halle, Deutschland
,
S Pohl
1   Martin-Luther-Universität Halle (Saale), Innere Medizin I, Halle, Deutschland
,
A Zipprich
1   Martin-Luther-Universität Halle (Saale), Innere Medizin I, Halle, Deutschland
› Author Affiliations
Further Information

Publication History

Publication Date:
02 August 2017 (online)

 

Introduction:

The glyoxalase system is formed by the enzymes glyoxalase-I (Glo-I) and Glo-II and constitutes an efficient enzymatic detoxification system suppressing the formation of a cytotoxic byproduct methylglyoxal (MGO). Tumors with a high glycolytic activity require a higher rate of MGO-detoxification. Our aim was to investigate the Glo-I activity in different hepatocellular cancer (HCC) cell lines and the subsequent role of Glo-I for proliferation and migration.

Methods:

The expression and specific activity of Glo-I was measured in different HCC-cell lines with different proliferative properties (less to more: AML-12, HepG2, Huh7) using enzyme kinetics and western-blot. Expression and kinetics were compared and correlated with proliferation (WST). Pharmacologic inhibition of Glo-I in Huh-7 cell line was achieved by using two independent inhibitors ethyl pyruvate (EP, 1 – 20mM, 24h) and BrBzGSHCp2 (1 – 10uM, 24h). Following the inhibition, proliferation (WST, clonogenic assay) and migration (WB: PDGFR, ERK, pERK; scratch assay) was assessed.

Results:

Huh7 revealed highest expression of Glo-I in WB (194 ± 31%) and RT-PCR analysis as compared to AML-12 (100 ± 19%, p < 0.05) and HepG2 (142 ± 35%). In addition, the highest specific activity of Glo-I was detected in Huh7 (0.6 ± 0.1 U/mg) compared to AML-12 (0.4 ± 0.1 U/mg, p < 0.05) and HepG2 (0.32 ± 0.1 U/mg, p < 0.05). Subsequent inhibition of Glo-I in Huh-7 with EP or BrBzGSHCp2 reduced the proliferation significantly (24h-Wst: EP 15mM 66.9 ± 6.4%, p = 0.03; 10µM BrBzGSHCp2 29.6 ± 9.3%, p = 0.005) compared to Huh-7 without EP or BrBzGSHCp2 (100%). Same results were found using clonogenic assay (5mM EP: 0.7 ± 0.8 vs. 14.8 ± 8.1 colonies, p < 0.001). EP treatment of Huh7 cells also showed decreased protein expression of PDGFR (17.5 ± 5.5%, p = 0.014) and pERK (75.8 ± 6.2%, p = 0.038) compared to Huh-7 without EP or BrBzGSHCp2 (100%). Furthermore, cell migration was reduced following inhibition of Glo-I (wound area: EP 8.8 ± 0.6% vs. 4.6 ± 1.3%, p < 0.001).

Conclusion:

A higher expression and activity of Glo-I is associated with higher proliferation rate in HCC cell lines. Decreasing the activity of Glo-I leads to decreased proliferation and migration. Therefore, blocking of Glo-I activity could be a promising therapeutic strategy in HCC.