Gut Liver.  2013 Nov;7(6):739-746.

Expression of Heat Shock Protein 70 Modulates the Chemoresponsiveness of Pancreatic Cancer

• Hyun JJ
• Lee HS
• Keum B
• Seo YS
• Jeen YT
• Chun HJ
• Um SH
• Kim CD

Abstract

BACKGROUND/AIMS
Heat shock protein (HSP) 70 is constitutively overexpressed in pancreatic cancer cells (PCCs) and appears to confer protection against chemotherapeutics. We investigated whether modulating HSP 70 increases chemoresponsiveness to gemcitabine in PCCs.
METHODS
Varying concentrations of quercetin and gemcitabine, either alone or in combination, were added to PCCs (Panc-1 and MiaPaCa-2). MTT assay was performed to analyze cell viability. HSP 70 expression was assessed by Western blot analysis. Apoptosis was determined by measuring caspase-3 activity. Western blot for the LC3-II protein detected the presence of autophagy.
RESULTS
HSP 70 levels were not affected by the incubation of Panc-1 and MiaPaCa-2 cells with gemcitabine, whereas with quercetin, the levels were reduced in both cell lines. The viability of both Panc-1 and MiaPaCa-2 cells significantly decreased with gemcitabine treatment but not with quercetin. A combination of gemcitabine and quercetin decreased the viability of both cell lines in a dose-dependent manner, which was more pronounced than gemcitabine treatment alone. Treatment with either gemcitabine or quercetin augmented caspase-3 activity in both cell lines, and a combination of these compounds further potentiated caspase-3 activity. LC3-II protein expression was negligible with gemcitabine treatment but marked with quercetin. The addition of gemcitabine to quercetin did not potentiate LC3-II protein expression.
CONCLUSIONS
Modulation of HSP 70 expression with quercetin enhanced the chemoresponsiveness of PCCs to gemcitabine. The mechanism of cell death was both apoptosis and autophagy.

Keyword

Gemcitabine; Heat shock proteins; Pancreatic neoplasms; Quercetin

MeSH Terms

Antineoplastic Combined Chemotherapy Protocols/*pharmacology
Apoptosis/drug effects
Autophagy/drug effects
Caspase 3/metabolism
Cell Line, Tumor
Cell Survival/*drug effects
Deoxycytidine/analogs & derivatives/pharmacology
Drug Resistance, Neoplasm/*drug effects
HSP70 Heat-Shock Proteins/*metabolism
Humans
Microtubule-Associated Proteins/metabolism
Pancreatic Neoplasms/*drug therapy
Quercetin/pharmacology
Caspase 3
Deoxycytidine
HSP70 Heat-Shock Proteins
Microtubule-Associated Proteins
Quercetin