High Expression of KIFC1 in Glioma Correlates with Poor Prognosis.

OBJECTIVE: Kinesin family member C1 (KIFC1), a non-essential kinesin-like motor protein, has been found to serve a crucial role in supernumerary centrosome clustering and the progression of several human cancer types. However, the role of KIFC1 in glioma has been rarely reported. Thus, the present study aimed to investigate the role of KIFC1 in glioma progression. METHODS: Online bioinformatics analysis was performed to determine the association between KIFC1 expression and clinical outcomes in glioma. Immunohistochemical staining was conducted to analyze the expression levels of KIFC1 in glioma and normal brain tissues. Furthermore, KIFC1 expression was knocked in the glioma cell lines, U251 and U87MG, and the functional roles of KIFC1 in cell proliferation, invasion and migration were analyzed using cell multiplication, wound healing and Transwell invasion assays, respectively. The autophagic flux and expression levels matrix metalloproteinase-2 (MMP2) were also determined using imaging flow cytometry, western blotting and a gelation zymography assay. RESULTS: The results revealed that KIFC1 expression levels were significantly upregulated in glioma tissues compared with normal brain tissues, and the expression levels were positively associated with tumor grade. Patients with glioma with low KIFC1 expression levels had a more favorable prognosis compared with patients with high KIFC1 expression levels. In vitro, KIFC1 knockdown not only inhibited the proliferation, migration and invasion of glioma cells, but also increased the autophagic flux and downregulated the expression levels of MMP2. CONCLUSION: Upregulation of KIFC1 expression may promote glioma progression and KIFC1 may serve as a potential prognostic biomarker and possible therapeutic target for glioma.

Artesunate ameliorates sepsis-induced acute lung injury by activating the mTOR/AKT/PI3K axis.

Sepsis-induced acute lung injury (ALI) remains one of the most common disorders in hospitals. The aim of this research was to explore the underlying characteristics and mechanisms of artesunate (AS) in protecting rat lungs from sepsis. The sepsis-induced ALI model was generated in SD rats by the intratracheal administration of lipopolysaccharide (LPS, 5 mg/kg) for 24 h. The rats were randomly assigned into 4 groups: Sham, LPS, LPS + AS, and LPS + AS + LY294002. Pathological evaluation of the lungs was conducted by HE staining, immunofluorescence, and TUNEL assay, and the MPO activity and the W/D ratio of each group were evaluated. The levels of inflammatory mediators (TNF-α and IL-6) were measured by immunoblotting, immunofluorescence and real-time PCR. Western blotting was used to determine the protein levels of PI3K, cleaved Caspase-3, p-mTOR, mTOR, p-Akt, and Akt in the lungs. The MPO activity, W/D ratio and lung injury score were obviously elevated after induction of ALI by LPS. Nevertheless, these alterations could be inhibited by AS. In addition, sepsis decreased the levels of p-mTOR, p-Akt, and PI3K and elevated the expression of cl-caspase-3, TNF-α, and IL-6 in the lungs. After AS administration, these alterations were obviously decreased, but treatment with the PI3K antagonist LY294002 inhibited the function of AS. AS could partially protect against LPS-induced ALI by inhibiting apoptosis and inflammatory mediator production, and this function is perhaps associated with the regulation of the mTOR/AKT/PI3K axis. These findings suggest that AS may possess certain beneficial characteristics in protecting the lungs from sepsis.

Golgi phosphoprotein 3 sensitizes the tumour suppression effect of gefitinib on gliomas.

OBJECTIVES: We previously reported that Golgi phosphoprotein 3 (GOLPH3) promotes glioma progression by inhibiting EGFR endocytosis and degradation, leading to EGFR accumulation and PI3K-AKT pathway over-activation. In the current study, we examine whether GOLPH3 affects the response of glioma cells to gefitinib, an EGFR selective inhibitor. MATERIALS AND METHODS: The expression of GOLPH3 and EGFR in glioma cells was detected by immunofluorescence and immunoblotting. The cell viability or growth in vitro was determined by CCK-8, EdU incorporation and clonogenic assays. The primary glioma cells were cultured by trypsin and mechanical digestion. The transwell invasion assay was used to examine the primary glioma cell motility. Intracranial glioma model in nude mice were established to explore the sensitivity of gefitinib to GOLPH3 high cancer cells in vivo. RESULTS: Both the immortalized and primary glioma cells with GOLPH3 over-expression hold higher EGFR protein levels on the cell membrane and exhibited higher sensitivity to gefitinib. In addition, primary glioma cells with higher GOLPH3 level exhibited stronger proliferation behaviour. Importantly, GOLPH3 enhanced the anti-tumour effect of gefitinib in vivo. Consistently, after gefitinib treatment, tumours derived from GOLPH3 over-expression cells exhibited lower Ki67-positive and higher cleaved caspase-3-positive cells than control tumours. CONCLUSIONS: Our results demonstrate that GOLPH3 increases the sensitivity of glioma cells to gefitinib. Our study provides foundation for further exploring whether GOLPH3 high gliomas will be more sensitive to anti-EGFR therapy in clinic and give ideas for developing new possible treatments for individual glioma patients.

ß-catenin-mediated YAP signaling promotes human glioma growth.

BACKGROUND: Hippo/YAP pathway is known to be important for development, growth and organogenesis, and dysregulation of this pathway leads to tumor progression.We and others find that YAP is up-regulated in human gliomas and associated with worse prognosis of patients. However, the role and mechanism of YAP in glioma progression is largely unknown. METHODS: The expression of YAP in glioma tissues was detected by quantitative polymerase chain reaction (qPCR) and immunoblotting. The effect of YAP on glioma progression was examined using cell growth assays and intracranial glioma model. The effect of YAP on ß-catenin protein level, subcellular location and transcription activity was examined by immunoblotting, immunofluorescence and RT-PCR. RESULTS: Firstly, knockdown of YAP inhibited glioma cell proliferation in vitro and tumor growth in vivo. In addition, YAP modulated the protein level, subcellular location and transcription activity of ß-catenin via regulating the activity of GSK3ß. Lastly, ß-catenin partially mediated the effect of YAP on glioma cell proliferation. CONCLUSION: Our findings identify that YAP promotes human glioma growth through enhancing Wnt/ß-catenin signaling. In addition, this study provides a new crosstalk mechanism between Hippo/YAP and Wnt/ß-catenin pathways, which suggests a new strategy for human glioma treatment.

Golgi phosphoprotein 3 promotes glioma progression via inhibiting Rab5-mediated endocytosis and degradation of epidermal growth factor receptor.

BACKGROUND: Golgi phosphoprotein 3 (GOLPH3) is associated with worse prognosis of gliomas, but its role and mechanism in glioma progression remain largely unknown. This study aimed to explore the role and mechanism of GOLPH3 in glioma progression. METHODS: The expression of GOLPH3 in glioma tissues was detected by quantitative PCR, immunoblotting, and immunohistochemistry. GOLPH3's effect on glioma progression was examined using cell growth assays and an intracranial glioma model. The effect of GOLPH3 on epidermal growth factor receptor (EGFR) stability, endocytosis, and degradation was examined by immunoblotting and immunofluorescence. The activity of Rab5 was checked by glutathione S-transferase pulldown assay. RESULTS: GOLPH3 was upregulated in gliomas, and its downregulation inhibited glioma cell proliferation both in vitro and in vivo. Furthermore, GOLPH3 depletion dampened EGFR signaling by enhancing EGFR endocytosis, driving EGFR into late endosome and promoting lysosome-mediated degradation. Interestingly, GOLPH3 bound to Rab5 and GOLPH3 downregulation promoted the activation of Rab5. In addition, Rab5 depletion abolished the effect of GOLPH3 on EGFR endocytosis and degradation. CONCLUSION: Our results imply that GOLPH3 promotes glioma cell proliferation via inhibiting Rab5-mediated endocytosis and degradation of EGFR, thereby activating the phosphatidylinositol-3 kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway. We find a new mechanism by which GOLPH3 promotes tumor progression through regulating cell surface receptor trafficking. Extensive and intensive understanding of the role of GOLPH3 in glioma progression may provide an opportunity to develop a novel molecular therapeutic target for gliomas.

Protein kinase D2 promotes the proliferation of glioma cells by regulating Golgi phosphoprotein 3.

Protein kinase D2 (PKD2) has been demonstrated to promote tumorigenesis in many types of cancers. However, how PKD2 regulates cancer cell growth is largely unknown. In this study, we found that over-expression of PKD2 promoted glioma cell growth but down-regulation of PKD2 inhibited it. Further investigation indicated that PKD2 down-regulation decreased the protein level of Golgi phosphoprotein 3(GOLPH3) as well as p-AKT level. On the contrary, over-expression of PKD2 increased the protein level of GOLPH3 and p-AKT. In addition, GOLPH3 exhibited similar effect on glioma cell growth to that of PKD2. Importantly, GOLPH3 down-regulation partially abolished glioma cell proliferation induced by PKD2 over-expression, while over-expression of GOLPH3 also partially rescued the inhibition effect of PKD2 down-regulation on glioma cell growth. Interestingly, the level of PKD2 and GOLPH3 significantly increased and was positively correlated in a cohort of glioma patients, as well as in patients from TCGA database. Taken together, these results reveal that PKD2 promotes glioma cell proliferation by regulating GOLPH3 and then AKT activation. Our findings indicate that both PKD2 and GOLPH3 play important roles in the progression of human gliomas and PKD2-GOLPH3-AKT signaling pathway might be a potential glioma therapeutic target.