High expression of Golgi phosphoprotein-3 is associated with poor survival in patients with hepatocellular carcinoma

Golgi Phosphoprotein 3 Promotes Colon Cancer Cell Metastasis Through STAT3 and Integrin α3 Pathways

Background: Golgi phosphoprotein 3 (GOLPH3) overexpression was recently reported to be associated with a poor clinical outcome in patients with colorectal cancer (CRC). However, the underlying molecular mechanism through which GOLPH3 promotes CRC metastasis remains poorly understood.

Methods:In vitro genetic ablation of GOLPH3 was performed using siRNA transfection, and a stably overexpressed GOLPH3 colon cancer cell line was constructed using the lentivirus system. Cell invasion and migration assays were conducted with or without Matrigel. Immunoblotting, qRT-PCR, immunofluorescence and immunohistochemistry were utilized to study the expression level of GOLPH3, ZEB1, integrin α3 and phosphorylation level of STAT3, AKT/mTOR and Raf/MEK/ERK pathways. Co-immunoprecipitation was used to investigate the interaction between GOLPH3 and p-STAT3 (Tyr705) or total STAT3.

Results: Overexpression of GOLPH3 was found in CRC tissues and colon cancer cell lines. Knockdown of GOLPH3 using siRNAs significantly suppressed the invasion and migration of HCT116 and HCT8 cells. In contrast, the overexpression of GOLPH3 promoted the migratory and invasive ability of colon cancer cells. The phosphorylation level of STAT3 as well as the protein and mRNA levels of ZEB1 and integrin α3, were significantly decreased after GOLPH3 knockdown. Moreover, Integrin α3 expression was correlated with GOLPH3 expression in CRC tissues. Co-immunoprecipitation assay revealed that GOLPH3 interacted with pSTAT3 (Tyr705) and total STAT3. Our further experiments suggested that GOLPH3 facilitated IL-6 induced STAT3 activation and subsequently induced transcription of integrin α3 and ZEB1, which promoted the metastasis and progression of CRC.

Conclusion: Our current work demonstrates that GOLPH3 facilitates STAT3 activation and regulates the expression of EMT transcription factor ZEB1 and Integrin α3 in colon cancer cells. These findings indicate that GOLPH3 plays a critical role in CRC metastasis and might be a new therapeutic target for CRC treatment.

MiR-3150b inhibits hepatocellular carcinoma cell proliferation, migration and invasion by targeting GOLPH3

BACKGROUND

In this study, we aimed to explore the potential involvement of miR-3150b in hepatocellular carcinoma (HCC) carcinogenesis.

METHODS

The expression of miR-3150b and Golgi phosphoprotein 3 (GOLPH3) was determined in HCC cell lines. Cell proliferation, migration and invasion were estimated by Cell Counting Kit-8, wound healing and Transwell assays. The association between miR-3150b and GOLPH3 was verified by luciferase assay.

RESULTS

MiR-3150b was downregulated, while GOLPH3 was remarkably upregulated in HCC cells. Furthermore, miR-3150b inhibited HCC cell proliferation, migration and invasion. MiR-3150b directly targeted and negatively regulated GOLPH3.

CONCLUSION

MiR-3150b suppressed HCC cell proliferation, invasion and migration by targeting GOLPH3.

Golgi protein 73 and its diagnostic value in liver diseases

Golgi protein 73 (GP73, also referred to as Golph 2) with 400 amino acids is a 73 kDa transmembrane glycoprotein typically found in the cis-Golg complex. It is primarily expressed in epithelial cells, which has been found upregulated in hepatocytes in patients suffering from both viral and non-viral liver diseases. GP73 has drawn increasing attention for its potential application in the diagnosis of liver diseases such as hepatitis, liver cirrhosis and liver cancer. Herein, we reviewed the discovery history of GP73 and summarized studies by many groups around the world, aiming at understanding its structure, expression, function, detection methods and the relationship between GP73 and liver diseases in various settings.

The knocking down of the oncoprotein Golgi phosphoprotein 3 in T98G cells of glioblastoma multiforme disrupts cell migration by affecting focal adhesion dynamics in a focal adhesion kinase-dependent manner

Golgi phosphoprotein 3 (GOLPH3) is a conserved protein of the Golgi apparatus that in humans has been implicated in tumorigenesis. However, the precise function of GOLPH3 in malignant transformation is still unknown. Nevertheless, clinicopathological data shows that in more than a dozen kinds of cancer, including gliomas, GOLPH3 could be found overexpressed, which correlates with poor prognosis. Experimental data shows that overexpression of GOLPH3 leads to transformation of primary cells and to tumor growth enhancement. Conversely, the knocking down of GOLPH3 in GOLPH3-overexpressing tumor cells reduces tumorigenic features, such as cell proliferation and cell migration and invasion. The cumulative evidence indicate that GOLPH3 is an oncoprotein that promotes tumorigenicity by a mechanism that impact at different levels in different types of cells, including the sorting of Golgi glycosyltransferases, signaling pathways, and the actin cytoskeleton. How GOLPH3 connects mechanistically these processes has not been determined yet. Further studies are important to have a more complete understanding of the role of GOLPH3 as oncoprotein. Given the genetic diversity in cancer, a still outstanding aspect is how in this inherent heterogeneity GOLPH3 could possibly exert its oncogenic function. We have aimed to evaluate the contribution of GOLPH3 overexpression in the malignant phenotype of different types of tumor cells. Here, we analyzed the effect on cell migration that resulted from stable, RNAi-mediated knocking down of GOLPH3 in T98G cells of glioblastoma multiforme, a human glioma cell line with unique features. We found that the reduction of GOLPH3 levels produced dramatic changes in cell morphology, involving rearrangements of the actin cytoskeleton and reduction in the number and dynamics of focal adhesions. These effects correlated with decreased cell migration and invasion due to affected persistence and directionality of cell motility. Moreover, the knocking down of GOLPH3 also caused a reduction in autoactivation of focal adhesion kinase (FAK), a cytoplasmic tyrosine kinase that regulates focal adhesions. Our data support a model in which GOLPH3 in T98G cells promotes cell migration by stimulating the activity of FAK.

GOLPH3: a Golgi phosphatidylinositol(4)phosphate effector that directs vesicle trafficking and drives cancer

GOLPH3 is a peripheral membrane protein localized to the Golgi and its vesicles, but its purpose had been unclear. We found that GOLPH3 binds specifically to the phosphoinositide phosphatidylinositol(4)phosphate [PtdIns(4)P], which functions at the Golgi to promote vesicle exit for trafficking to the plasma membrane. PtdIns(4)P is enriched at the trans-Golgi and so recruits GOLPH3. Here, a GOLPH3 complex is formed when it binds to myosin18A (MYO18A), which binds F-actin. This complex generates a pulling force to extract vesicles from the Golgi; interference with this GOLPH3 complex results in dramatically reduced vesicle trafficking. The GOLPH3 complex has been identified as a driver of cancer in humans, likely through multiple mechanisms that activate secretory trafficking. In this review, we summarize the literature that identifies the nature of the GOLPH3 complex and its role in cancer. We also consider the GOLPH3 complex as a hub with the potential to reveal regulation of the Golgi and suggest the possibility of GOLPH3 complex inhibition as a therapeutic approach in cancer.

High MMP-26 expression in glioma is correlated with poor clinical outcome of patients

To date the management of glioma remains a great challenge in cancer therapy worldwide. The identification of novel diagnostic and therapeutic methods is required. Although there is data indicating that matrix metalloproteinase (MMP)-26 serves an important role in many human cancer types, its clinical significance in glioma remains uncertain. The present study aimed to evaluate MMP-26 expression in human astrocytic glioma specimens, and investigate its role and significance in the progression of astrocytic glioma. Immunohistochemistry was performed to assess MMP-26 expression in astrocytic glioma tissues. The levels of MMP-26 expression and its relevance to the clinicopathological features and prognostic factors in patients with astrocytic glioma patients were then investigated. The results demonstrated that MMP-26 expression was significantly assocaited with the World Health Organization grade (P<0.05). Additionally, it was identified that MMP-26 expression was an effective predictor of the overall survival of patients with astrocytic glioma (P<0.05). Analyses of univariate and multivariate Cox regression confirmed that MMP-26 expression was an independent factor for evaluating the prognosis of astrocytic glioma patients (P<0.05). The current results support that MMP-26 may be a novel indicator of diagnosis and an independent factor for evaluating prognosis in patients with glioma.

Golgi phosphoprotein 3 (GOLPH3) promotes hepatocellular carcinoma progression by activating mTOR signaling pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the second leading cause of cancer-related deaths worldwide. Despite new technologies in diagnosis and treatment, the incidence and mortality of HCC continue rising. And its pathogenesis is still unclear. As a highly conserved protein of the Golgi apparatus, Golgi phosphoprotein 3 (GOLPH3) has been shown to be involved in tumorigenesis of HCC. This study aimed to explore the exact oncogenic mechanism of GOLPH3 and provide a novel diagnose biomarker and therapeutic strategy for patients with HCC.

METHODS

Firstly, the expression of GOLPH3 was detected in the HCC tissue specimens and HCC cell lines. Secondly, RNA interference was used for GOLPH3 gene inhibition. Thirdly, cell proliferation was analyzed by MTT; cell apoptosis was analyzed by Annexin-V/PI staining, Hoechst 33,342 staining and caspase 3/7 activity assay. Fourthly, xenograft tumor model was used to study the function of GOLPH3 in tumor growth in vivo. Finally, western blotting and immunohistochemistry were used to investigate the role of GOLHP3 in the mTOR signaling pathway.

RESULTS

Data showed that the mRNA and protein expression of GOLPH3 were up-regulated in HCC tumor tissue and cell lines compared with those of control (P < 0.05). Correlation analyses showed that GOLPH3 expression was positively correlated with serum alpha-fetoprotein level (AFP, P = 0.006). Knockdown GOLPH3 expression inhibited proliferation and promoted apoptosis in HCC cell lines. What's more, knockdown GOLPH3 expression led to tumor growth restriction in xenograft tumor model. The expression of phosphorylated mTOR, AKT and S6 K1 were significantly higher in HCC tumor tissue and cell lines compared with those in normal liver tissues (p < 0.05). While the phosphorylated mTOR, AKT and S6 K1 were much lower when diminished GOLPH3 expression in HCC cell lines both in vitro and in vivo.

CONCLUSION

The current study suggests that GOLPH3 contributes to the tumorigenesis of HCC by activating mTOR signaling pathway. GOLPH3 is a promising diagnose biomarker and therapeutic target for HCC. Our study may provide a scientific basis for developing effective approaches to treat the HCC patients with GOLPH3 overexpression.

GOLPH3 induces epithelial-mesenchymal transition via Wnt/β-catenin signaling pathway in epithelial ovarian cancer

Golgi phosphoprotein 3 (GOLPH3), a newly recognized oncogene, is associated with tumor growth, metastasis, and poor prognosis in several types of cancer. However, its biological role and underlying mechanism in epithelial ovarian cancer (EOC) remain poorly understood. Here, we found that GOLPH3 was overexpressed in EOC tissues and cell lines. This overexpression promoted the migration and invasion of EOC cells. Moreover, GOLPH3 upregulated the expression of epithelial–mesenchymal transition (EMT) markers, such as N‐cadherin and Snail, and the Wnt/β‐catenin‐related genes cyclin‐D1 and c‐Myc, which were restored via silencing of GOLPH3 expression. Furthermore, the inhibitor and activator of the Wnt/β‐catenin pathway, XAV939 and LiCl, enhanced or decreased, respectively, the effect of GOLPH3 on EMT, which further confirmed that GOLPH3 promoted EMT progression via activation of Wnt/β‐catenin signaling. In addition, we found that EDD, the human hyperplastic discs gene, was consistent with GOLPH3 expression and also promoted the EMT process and activated Wnt/β‐catenin signaling. These findings demonstrate that EDD might be a downstream factor of GOLPH3. Taken together, our findings demonstrate the existence of a GOLPH3–Wnt/β‐catenin–EMT axis in EOC and provide a new therapeutic target to treat EOC.

Correlation of GOLPH3 Gene with Wnt Signaling Pathway in Human Colon Cancer Cells

Objective: Overexpression of GOLPH3 in colorectal cancer tissue may promote cell proliferation and activate the Wnt signaling pathway. We investigated the correlation between GOLPH3 gene expression and the Wnt signaling pathway to explore the mechanism of the overexpression of GOLPH3 gene which promotes proliferation in human colon cancer cells.

Methods: We measured expression of GOLPH3 mRNA in the human colon cancer cell lines HCT116, HT29, SW480 and SW620 by RT-PCR, and the cells with the highest expression were selected and divided into four groups: negative control, GOLPH3 siRNA transfection (siRNA-GOLPH3), Akt inhibitor (Tricinbine), and glycogen synthase kinase (GSK)-3β inhibitor (TWS119). After human colon cancer cells were transfected with siRNA-GOLPH3, we used RT-PCR to investigate the silencing effect of GOLPH3 gene. We assessed the activity of the Wnt signaling pathway in all groups using the Topflash method. Proliferation and apoptosis of colon cancer SW620 cells were detected by MTT assay, colony formation assay and flow cytometry. Expression of Golgi phosphoprotein (GOLPH)3, β-catenin, GSK-3β and pS9-GSK-3β in cancer cells was determined by Western blotting.

Results: SW620 cells expressed the highest level of GOLPH3 mRNA, and the silence effect was good after they were transfected with siRNA-GOLPH3. The relative luminescence units (RLU) values in the experimental groups were significantly lower than in the negative control group (P<0.001). There was no significant difference in the RLU values among the experimental groups (P> 0.05). The growth inhibition ratio and apoptosis rate of cancer cells in each experimental group were significantly higher than those in the control group, and the cell colony count in the experimental group was significantly lower than in the control group (P<0.05). In addition, the RLU value, proliferation and apoptosis rate of cancer cells did not differ significantly between each two experimental groups. Western blotting showed that, compared with the control group, expression of β-catenin and pS9-GSK3 proteins were significantly decreased in the experimental group. Expression of GSK-3β in the experimental group did not different from that of the control group.

Conclusions: Overexpression of GOLPH3 gene activated the Wnt signaling pathway, as well as increasing expression of β-catenin, promoting proliferation and inhibiting apoptosis in human colon cancer cells. The mechanism of action was that overexpression of GOLPH3 gene activated Akt, which may also further activate the Wnt signaling pathway via GSK-3β, and promote proliferation in human colon cancer cells.

Distinct Biochemical Pools of Golgi Phosphoprotein 3 in the Human Breast Cancer Cell Lines MCF7 and MDA-MB-231

Golgi phosphoprotein 3 (GOLPH3) has been implicated in the development of carcinomas in many human tissues, and is currently considered a bona fide oncoprotein. Importantly, several tumor types show overexpression of GOLPH3, which is associated with tumor progress and poor prognosis. However, the underlying molecular mechanisms that connect GOLPH3 function with tumorigenicity are poorly understood. Experimental evidence shows that depletion of GOLPH3 abolishes transformation and proliferation of tumor cells in GOLPH3-overexpressing cell lines. Conversely, GOLPH3 overexpression drives transformation of primary cell lines and enhances mouse xenograft tumor growth in vivo. This evidence suggests that overexpression of GOLPH3 could result in distinct features of GOLPH3 in tumor cells compared to that of non-tumorigenic cells. GOLPH3 is a peripheral membrane protein mostly localized at the trans-Golgi network, and its association with Golgi membranes depends on binding to phosphatidylinositol-4-phosphate. GOLPH3 is also contained in a large cytosolic pool that rapidly exchanges with Golgi-associated pools. GOLPH3 has also been observed associated with vesicles and tubules arising from the Golgi, as well as other cellular compartments, and hence it has been implicated in several membrane trafficking events. Whether these and other features are typical to all different types of cells is unknown. Moreover, it remains undetermined how GOLPH3 acts as an oncoprotein at the Golgi. Therefore, to better understand the roles of GOLPH3 in cancer cells, we sought to compare some of its biochemical and cellular properties in the human breast cancer cell lines MCF7 and MDA-MB-231 with that of the non-tumorigenic breast human cell line MCF 10A. We found unexpected differences that support the notion that in different cancer cells, overexpression of GOLPH3 functions in diverse fashions, which may influence specific tumorigenic phenotypes.

Golgi phosphoprotein 3 (GOLPH3) promotes hepatocellular carcinoma cell aggressiveness by activating the NF-κB pathway

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies, in which the NF-κB pathway plays an important role and is constitutively activated. Better understanding of the molecular pathogenesis of HCC and the NF-κB pathway are needed to improve patient outcomes. Herein, we identified an unappreciated protein involved in NF-κB-induced activation, Golgi phosphoprotein 3 (GOLPH3). The mRNA and protein expression levels of GOLPH3 were frequently up-regulated in HCC and GOLPH3 expression correlated closely with clinical stage and survival in both the testing and validation cohorts. Ectopic over-expression of GOLPH3 in PLC/PRF/5 (PLC) and Huh7 HCC cells protected against cisplatin-induced apoptosis, promoted angiogenesis and proliferation and increased the aggressiveness of HCC cells in vitro and in vivo, whereas inhibition of GOLPH3 led to decreased aggressiveness. Through analysis of two published HCC patient profiles, GOLPH3 expression significantly correlated with NF-κB signalling. Furthermore, we demonstrated that GOLPH3 promoted K63-linked polyubiquitination of tumour necrosis factor receptor-associated factor 2 (TRAF2), receptor interacting protein (RIP) and NF-κB essential modulator (NEMO) and substantially sustained the activation of NF-κB in HCC cells. Taken together, our findings provided evidence that GOLPH3 is a prognostic and/or potential therapeutic biomarker for HCC patients and plays an important role in activation of the NF-κB pathway during HCC progression.

The multiple cellular functions of the oncoprotein Golgi phosphoprotein 3

The highly conserved Golgi phosphoprotein 3 (GOLPH3) protein, a component of Trans-Golgi Network (TGN), has been defined as a "first-in-class Golgi oncoprotein" and characterized as a Phosphatidylinositol 4-phosphate [PI(4)P] effector at the Golgi. GOLPH3 is commonly amplified in several solid tumors. Furthermore this protein has been associated with poor prognosis in many cancers. Highly conserved from yeast to humans, GOLPH3 provides an essential function in vesicle trafficking and Golgi structure. Recent data have also implicated this oncoprotein in regulation of cytokinesis, modulation of mitochondrial mass and cellular response to DNA damage. A minute dissection of the molecular pathways that require GOLPH3 protein will be helpful to develop new therapeutic cancer strategies.

GOLPH3 links the Golgi, DNA damage, and cancer

GOLPH3 is the first example of an oncogene that functions in secretory trafficking at the Golgi. The discovery of GOLPH3's roles in both cancer and Golgi trafficking raises questions about how GOLPH3 and the Golgi contribute to cancer. Our recent investigation of the regulation of GOLPH3 revealed a surprising response by the Golgi upon DNA damage that is mediated by DNA-PK and GOLPH3. These results provide new insight into the DNA damage response with important implications for understanding the cellular response to standard cancer therapeutic agents.