High Kpnß1 expression promotes non-small cell lung cancer proliferation and chemoresistance via the PI3-kinase/AKT pathway.

Karyopherin ß1 (Kpnß1), also known as importin-ß, is part of the karyopherin superfamily of nuclear transport proteins. Kpnß1 is an oncogene that is overexpressed in various human cancers. Recent studies have showed that Kpnß1 is one of the leading causes of cancer-related deaths in the world. However, the role of Kpnß1 in non-small cell lung cancer (NSCLC) remains uncertain. In this study, we used western blotting to show that Kpnß1 expression is higher in lung-cancer tissues and cells, and immunohistochemistry analysis revealed that Kpnß1 was significantly associated with the clinicopathological features of NSCLC. Kaplan-Meier analysis showed that elevated Kpnß1 expression correlated with a poor prognosis in NSCLC patients. Serum starvation-refeeding experiments and Kpnß1-shRNA transfection assays revealed that elevated Kpnß1 expression promoted cell proliferation and reduced sensitivity to cis-diamminedichloroplatinum. Immunoprecipitation assays showed that Kpnß1 interacts with PI3 K to activate the PI3-kinase/AKT pathway, leading to enhanced cell survival and drug resistance in NSCLC cells. Collectively, our findings suggest that Kpnß1 plays a significant role in NSCLC progression and chemoresistance. Our study provides new insights for targeted therapy to treat NSCLC.

Upregulation of KPNß1 in gastric cancer cell promotes tumor cell proliferation and predicts poor prognosis.

KPNß1, also known as importin ß, P97, is reported as one of soluble transport factors that mediates transportion of proteins and RNAs between the nucleus and cytoplasm in cellular process. Recent studies show that KPNß1 is a tumor gene which is highly expressed in several malignant tumors such as ovarian cancer, cervical tumor, neck cancer, and lung cancer via promoting cell proliferation or inhibiting cell apoptotic pathways. However, the the role of KPNß1 in gastric cancer remains unclear. In this study, Western blot and immunohistochemistrical analyses showed that KPNß1 was significantly upregulated in clinical gastric cancer specimens compared with adjacent noncancerous tissues. KPNß1 was positively correlated with tumor grade, Ki-67, and predicted poor prognosis of gastric cancer. More importantly, through starvation-refeeding model, CCK8 assay, flow cytometry, colony formation assays, the vitro studies demonstrated that KPNß1 promoted proliferation of gastric cancer cells, while KPNß1 knockdown led to decreased cell proliferation and arrested cell cycle at G1 phase. Furthermore, our results also indicated that KPNß1 expression could result in docetaxel resistance. And, KPNß1 could interact with Stat1, contributed to its nucleus import in gastric cancer cells. These findings provided a novel promising therapeutic targets for clinical treatment against human gastric cancer.

Upregulation of nuclear transporter, Kpnß1, contributes to accelerated cell proliferation- and cell adhesion-mediated drug resistance (CAM-DR) in diffuse large B-cell lymphoma.

BACKGROUND: The Karyopherin proteins are involved in the shuttling of cargo proteins, and certain RNAs, across the nuclear pore complex into and out of the cell nucleus. Karyopherin ß1 (Kpnß1) is a member of the Karyopherin ß superfamily of nuclear transport proteins. In addition to the nuclear import function, Kpnß1 is associated with the occurrence of tumors. This study investigated the expression and biologic function of Kpnß1 in diffuse large B-cell lymphoma (DLBCL). METHODS: The prognostic value of Kpnß1 expression was evaluated using immunohistochemical staining. The role of Kpnß1 on cell proliferation- and cell adhesion-mediated drug resistance (CAM-DR) was also determined. RESULTS: We demonstrated that Kpnß1 mRNA and protein expression levels were significantly higher in DLBCL B-cells and DLBCL cell lines than in normal CD19 purified B-cells. Immunohistochemical analysis suggested that the expression of Kpnß1 was correlated with Ki-67 (P < 0.001). Kaplan-Meier curve showed that high expression of Kpnß1 was significantly associated with shorter overall survival. In addition, Kpnß1 was associated with the proliferation of DLBCL cells. Importantly, we found that Kpnß1 could interact with p65 and promote CAM-DR via accelerating NF-κB activation in DLBCL. CONCLUSIONS: Patients with tumors highly expressing Kpnß1 have poorer overall survivals. Kpnß1 interacts with p65 and enhances CAM-DR.

KPNß1 promotes palmitate-induced insulin resistance via NF-κB signaling in hepatocytes.

It has been intensively studied that inflammation contributes to the insulin resistance development in obesity-induced type 2 diabetes mellitus (T2DM). In this study, we assessed the effect of karyopherin ß1 (KPNß1) in hepatic insulin resistance and the underlying mechanisms using high-fat diet (HFD) fed mice and palmitate (PA)-stimulated hepatocytes (HepG2). KPNß1 expression is increased in the HFD fed mice liver. PA upregulated KPNß1 expression in HepG2 cells in a time-dependent manner. PA also increased pro-inflammatory cytokines expression, including tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1ß (IL-1ß). KPNß1 knockdown reversed PA-induced pro-inflammatory cytokines expression and insulin-stimulated glucose uptake in HepG2 cells. In addition, KPNß1 knockdown reduced intracellular lipid accumulation. Mechanistically, KPNß1 transports nuclear factor kB (NF-κB) p65 from the cytoplasm to the nucleus to increase pro-inflammatory genes expression. In summary, KPNß1 acts as a positive regulator in the NF-κB pathway to enhance palmitate-induced inflammation response and insulin resistance in HepG2 cells.