Inhibition of ERK1/2 in cancer-associated pancreatic stellate cells suppresses cancer-stromal interaction and metastasis
- J Exp Clin Cancer Res. 2019 May 27;38(1):221. doi: 10.1186/s13046-019-1226-8.
- 1. Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka, 812-8582, Japan.
- 2. Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka, 812-8582, Japan. [email protected].
- 3. Department of Advanced Medical Initiatives, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. [email protected].
- 4. Department of General Surgery, Shenzhen University General Hospital, Shenzhen, China.
- 5. Department of Advanced Medical Initiatives, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
- 6. Cancer Center of Kyushu University Hospital, Fukuoka, Japan.
- 7. Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka, 812-8582, Japan. [email protected].
Background: Extracellular signal-regulated kinases (ERKs) have been related to multiple cancers, including breast Cancer, hepatocellular Cancer, lung Cancer and colorectal Cancer. ERK1/2 inhibitor can suppress growth of KRAS-mutant pancreatic tumors by targeting Cancer cell. However, no studies have shown the expression of ERK1/2 on pancreatic stromal and its effect on pancreatic cancer-stromal interaction.
Methods: Immunohistochemistry and western blotting were performed to detect the expression of p-ERK1/2 in pancreatic tissues and cells. Cell viability assay was used to study IC50 of ERK Inhibitor on pancreatic Cancer cells (PCCs) and primary cancer-associated pancreatic stellate cells (PSCs). Transwell migration, invasion, cell viability assay, senescence β-galactosidase staining were performed to determine the effect of ERK Inhibitor on PCCs and PSCs in vitro and in vivo. The expression of key factors involved in Autophagy and epithelial-to-mesenchymal transition (EMT) process were evaluated by western blotting. The expression of key factors related to cell invasiveness and malignancy were confirmed by qRT-PCR. Co-transplantation of PCC Organoid and PSC using a splenic xenograft mouse model was used to evaluated combined treatment of ERK Inhibitor and Autophagy inhibitor.
Results: Immunohistochemical staining in pancreatic tumor samples and transgenetic mice detected p-ERK1/2 expression in both Cancer cells and stromal cells. In pancreatic tissues, p-ERK1/2 was strongly expressed in cancer-associated PSCs compared with Cancer cells and normal PSCs. PSCs were also significantly more sensitive to ERK1/2 inhibitor treatment. Inhibition of ERK1/2 suppressed EMT transition in HMPCCs, upregulated cellular senescence markers, activated Autophagy in cancer-associated PSCs; and suppressed cancer-stromal interaction, which enhanced invasiveness and viability of Cancer cells. We also found that chloroquine, an Autophagy inhibitor, suppressed ERK inhibition-induced Autophagy and promoted PSC cellular senescence, leading to significantly decreased cell proliferation. The combination of an ERK Inhibitor and Autophagy inhibitor suppressed liver metastasis in a splenic pancreatic cancer Organoid xenograft mouse model.
Conclusions: These data indicate that inhibition of ERK1/2 in cancer-associated pancreatic stellate cells suppresses cancer-stromal interaction and metastasis.