Role of POU1F1 promoting the properties of stemness of gastric carcinoma through ENO1-mediated glycolysis reprogramming.

Cancer stem cells (CSCs), a rare subset of tumor cells, have been recognized as promotive role on tumor initiation and propagation. Among, aerobic glycolysis, widely clarified in multiple tumor cells, is the key for maintaining cancer stemness. Regrettably, it is largely unknown about the connection of cellular metabolic reprogramming and stemness in gastric carcinoma (GC). Two GC parental cells lines PAMC-82 and SNU-16 and their spheroids were obtained to determine the expression status of POU1F1 using quantitative real-time PCR (qRT-PCR) and western blotting analysis, respectively. Gain or loss-of-function assay was employed to assess its biological effects. Sphere formation and transwell assays were performed to evaluate the stem cell-like traits, including self-renewal capacity, migration and invasion. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were conducted for determining the binding relationship of POU1F1 on ENO1 promoter region. Herein, aberrantly upregulated POU1F1 was observed in spheroids, compared with the parental PAMC-82 and SNU-16 cells, which promoted stem cell-like traits, as representing increasing sphere formation, enhanced cell migration and invasion. Additionally, POU1F1 expression was positively with glycolytic signaling, as displaying increasing glucose consumption, lactic acid production, and extracellular acid ratio (ECAR). Furthermore, POU1F1 was identified to be a transcriptional activator of ENO1, of which overexpression remarkably abolished POU1F1 knockdown-mediated blocking effects. Taken together, we draw a conclusion that POU1F1 facilitated the stem cell-like properties of GC cells through transcriptionally augmenting ENO1 to enhance glycolysis.

HMGA1B/2 transcriptionally activated-POU1F1 facilitates gastric carcinoma metastasis via CXCL12/CXCR4 axis-mediated macrophage polarization.

Tumor-associated macrophages (TAMs) in the tumor microenvironment contribute to poor prognosis in gastric cancer (GC). However, the underlying mechanism by which TAMs promote GC progression and metastasis remains elusive. Expression of POU1F1 was detected in 60 matched GC-normal tissue pairs using qRT-PCR and immunohistochemistry (IHC) analysis. The correlation between POU1F1 and the clinical-pathological factors of GC patients were further assessed. Cell proliferation was monitored by CCK-8, colony formation, and 5-Ethynyl-2'-deoxyuridine (EdU) incorporation assays. Cell migration and invasion were assessed by transwell assays. The impact on angiogenesis was evaluated by tube formation assay. Xenograft model was generated to investigate the role of POU1F1 on tumor growth and lung metastasis in vivo. GST pull-down and Co-immunoprecipitation (Co-IP) were used to study the interaction between HMGA1B/2 and POU1F1. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were performed to investigate the transcriptional regulation of POU1F1. Flow cytometry was performed to detect the surface expression of macrophage markers. Upregulated POU1F1 observed both in GC tissues and cell lines was positively correlated with poor prognosis. Knockdown of POU1F1 inhibited cell proliferation, migration, invasion, and angiogenesis in vitro, and suppressed tumor growth in vivo. HMGA1B/2 transcriptionally activated-POU1F1. POU1F1 promoted GC progression via regulating macrophage proliferation, migration, polarization, and angiogenesis in a CXCL12/CXCR4-dependent manner. POU1F1 also promoted GC metastasis in lung by modulating macrophage polarization through CXCL12/CXCR4 axis in vivo. HMGA1B/2-upregulated POU1F1 promoted GC metastasis via regulating macrophage polarization in a CXCL12/CXCR4-dependent manner.