TY - JOUR
T1 - Enhancing responsiveness of pancreatic cancer cells to gemcitabine treatment under hypoxia by heme oxygenase-1 inhibition
AU - Abdalla, Maher Y
AU - Ahmad, Iman M
AU - Rachagani, Satyanarayana
AU - Banerjee, Kasturi
AU - Thompson, Christopher M.
AU - Maurer, Hans C.
AU - Olive, Kenneth P.
AU - Bailey, Katie L.
AU - Britigan, Bradley E.
AU - Kumar, Sushil
N1 - Funding Information:
Conflict of Interest: All authors have read the journal's authorship agreement and policy and have no conflicts to declare. The authors thank Dr. Surinder Batra, Department of Biochemistry and Molecular Biology, UNMC for his contribution in this work. We also thank Dr. M.W. Nasser, Department of Biochemistry and Molecular Biology, UNMC for his help in the animal studies.
Publisher Copyright:
© 2019 Elsevier Inc.
PY - 2019/5
Y1 - 2019/5
N2 - Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies and has one of the worst prognoses leading to a meager 5-year survival rate of ∼8%. Chemotherapy has had limited success in extending the life span of patients with advanced PDAC due to poor tumor perfusion and hypoxia-induced resistance. Hypoxia reprograms the gene expression profile and upregulates the expression of multiple genes including heme oxygenase-1 (HO-1), which provide survival advantage to PDAC cells. However, the relationships between HO-1, hypoxia, and response to chemotherapy is unclear. Our results showed that hypoxia upregulates the expression of HO-1 in PDAC cells, and HO-1 inhibition using the HO-1 inhibitors zinc protoporphyrin, tin protoporphyrin IX (SnPP), and HO-1 knockout using CRISPR/Cas9 suppresses the proliferation of PDAC cells under hypoxia and sensitize them to gemcitabine under in vitro conditions. Treating orthotopic tumors with SnPP, or SnPP in combination with gemcitabine, significantly reduced the weight of pancreatic tumors (P < 0.05), decreased metastasis and improved the efficacy of gemcitabine treatment (P < 0.05). Mechanistically, inhibition of HO-1 increased the production of reactive oxygen species as demonstrated by increased dihydroethidium, and Mitosox, disrupted glutathione cycle, and enhanced apoptosis. There was significant increase in cleaved caspase-3 staining in tumors after combined treatment with SnPP and gemcitabine comparing to control or gemcitabine alone. In addition, inhibiting HO-1 reduced expression of stemness markers (CD133, and CD44) as compared to control or gemcitabine. Overall, our study may present a novel therapeutic regimen that might be adopted for the treatment of PDAC patients.
AB - Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies and has one of the worst prognoses leading to a meager 5-year survival rate of ∼8%. Chemotherapy has had limited success in extending the life span of patients with advanced PDAC due to poor tumor perfusion and hypoxia-induced resistance. Hypoxia reprograms the gene expression profile and upregulates the expression of multiple genes including heme oxygenase-1 (HO-1), which provide survival advantage to PDAC cells. However, the relationships between HO-1, hypoxia, and response to chemotherapy is unclear. Our results showed that hypoxia upregulates the expression of HO-1 in PDAC cells, and HO-1 inhibition using the HO-1 inhibitors zinc protoporphyrin, tin protoporphyrin IX (SnPP), and HO-1 knockout using CRISPR/Cas9 suppresses the proliferation of PDAC cells under hypoxia and sensitize them to gemcitabine under in vitro conditions. Treating orthotopic tumors with SnPP, or SnPP in combination with gemcitabine, significantly reduced the weight of pancreatic tumors (P < 0.05), decreased metastasis and improved the efficacy of gemcitabine treatment (P < 0.05). Mechanistically, inhibition of HO-1 increased the production of reactive oxygen species as demonstrated by increased dihydroethidium, and Mitosox, disrupted glutathione cycle, and enhanced apoptosis. There was significant increase in cleaved caspase-3 staining in tumors after combined treatment with SnPP and gemcitabine comparing to control or gemcitabine alone. In addition, inhibiting HO-1 reduced expression of stemness markers (CD133, and CD44) as compared to control or gemcitabine. Overall, our study may present a novel therapeutic regimen that might be adopted for the treatment of PDAC patients.
KW - Gemcitabine
KW - Heme oxygenase-1 (HO-1)
KW - Pancreatic ductal adenocarcinoma (PDAC)
KW - SnPP
KW - ZnPP
UR - http://www.scopus.com/inward/record.url?scp=85060115961&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85060115961&partnerID=8YFLogxK
U2 - 10.1016/j.trsl.2018.12.008
DO - 10.1016/j.trsl.2018.12.008
M3 - Article
C2 - 30653942
AN - SCOPUS:85060115961
VL - 207
SP - 56
EP - 69
JO - Translational Research
JF - Translational Research
SN - 1931-5244
ER -