Hedgehog (Hh) signaling is crucially involved in tumorigenesis. This study aimed to assess the role of Hh signaling in the regulation of epithelial-mesenchymal transition (EMT), stemness properties and chemoresistance of human pancreatic Panc-1 cancer stem cells (CSCs). Panc-1 cells were transfected with recombinant lentiviral vectors to silence SMO and serum-free floating-culture system was used to isolate Panc-1 tumorspheres. The expression of CSC and EMT markers was detected by flow cytometry, real-time RT-PCR and Western blot analysis. Malignant behaviors of Panc-1 CSC were evaluated by tumorigenicity assays and nude mouse lung metastasis model. We found that tumorspheres derived from pancreatic cancer cell line Panc-1 possessed self-renewal, differentiation and stemness properties. Hh pathway and EMT were active in Panc-1 tumorspheres. Inhibition of Hh signaling by SMO knockdown inhibited self-renewal, EMT, invasion, chemoresistance, pulmonary metastasis, tumorigenesis of pancreatic CSCs. In conclusion, Hh signaling contributes to the maintenance of stem-like properties and chemoresistance of pancreatic CSC and promotes the tumorigenesis and metastasis of pancreatic cancer. Hh pathway is a potential molecular target for the development of therapeutic strategies for pancreatic CSCs.

H19 is a long noncoding RNA differentially expressed in many tumors and participates in tumorigenesis. This study aimed to investigate the expression and function of H19 in pancreatic ductal adenocarcinoma (PDAC). Pure malignant cells were isolated from frozen sections of 25 PDAC cases by laser captured microdessection, and H19 expression level was detected by qRT-PCR. Knockdown and overexpression were employed to manipulate H19 levels in pancreatic cancer cells, then cell viability, proliferation, apoptosis and cell cycle, and the growth of xenografts were evaluated. E2F-1 levels in PDAC tissues were detected by Western blot and immunohistochemical analysis. We found that H19 was overexpressed in PDAC tissues and correlated to histological grade of PDAC. Knockdown of H19 in T3M4 and PANC-1 cells with high H19 endogenous level suppressed cell viability, proliferation and tumor growth, while H19 overexpression in COLO357 and CAPAN-1 with low H19 endogenous level enhanced cell viability, proliferation and tumor growth. Knockdown of H19 led to G0/G1 arrest, accompanied by decreased levels of E2F-1 and its downstream targets. E2F-1 was overexpressed in PDAC tissues with possible correlation with H19 expression level. In conclusion, H19 is overexpressed and plays oncogenic role in PDAC through promoting cancer cell proliferation via the upregulation of E2F-1.

Objective: The functional role and mechanism of the long noncoding RNA (lncRNA) H19 in regulating human pancreatic cancer (PC) cell stemness and invasion have not been completely elucidated. This study aimed to evaluate the role of H19 in regulating the stemness, epithelial-mesenchymal transition (EMT), invasion and chemosensitivity of PC cells.

Long non-coding RNA (lncRNA) MEG3 has been demonstrated to be a tumour suppressor in many malignancies. However, the functional role of MEG3 in pancreatic cancer (PC) is unclear. In this study, the expression pattern of MEG3 was evaluated in 25 samples of microdissected PC tissues and 8 PC cell lines and was compared to the expression in adjacent non‑cancerous tissues and a human pancreatic normal epithelial cell line. Loss of MEG3 expression was observed in both the cancerous tissues and cancer cell lines. Although the absence of expression of MEG3 was not statistically correlated to either histological grade or TNM stage in the 25 cases, the prognosis was significantly worse. MEG3 knockdown enhanced cell proliferation, promoted cell migration and invasion, induced epithelial‑mesenchymal transition (EMT), increased the sphere‑forming ability and cancer stem cell (CSC) properties, and decreased the chemosensitivity to gemcitabine in vitro. In contrast, forced expression of MEG3 resulted in a reverse effect. In conclusion, MEG3 functions as a tumour suppressor in human PC. The underlying cause of the poor prognosis induced by low levels of MEG3 expression in PC patients might involve EMT induction, enhanced CSC phenotypes and reduced chemoresistance, all of which might be associated with Snail activation.