Expression of GOLPH2 is associated with the progression of and poor prognosis in gastric cancer

GOLM1 dictates acquired Lenvatinib resistance by a GOLM1-CSN5 positive feedback loop upon EGFR signaling activation in hepatocellular carcinoma

Lenvatinib is a multiple receptor tyrosine kinases inhibitor (TKI) authorized for first-line treatment of hepatocellular carcinoma (HCC). However, Lenvatinib resistance is common in HCC clinical treatment, highlighting the urgent need to understand mechanisms of resistance. Here, we identified Golgi membrane protein 1 (GOLM1), a type II transmembrane protein originally located in the Golgi apparatus, as a novel regulator of Lenvatinib resistance. We found GOLM1 was overexpressed in Lenvatinib resistant human HCC cell lines, blood and HCC samples. Additionally, GOLM1 overexpression contributes to Lenvatinib resistance and HCC progression in vitro and in vivo. Mechanistically, GOLM1 upregulates CSN5 expression through EGFR-STAT3 pathway. Reversely, CSN5 deubiquitinates and stabilizes GOLM1 protein by inhibiting ubiquitin-proteasome pathway of GOLM1. Furthermore, clinical specimens of HCC showed a positive correlation between the activation of the GOLM1-EGFR-STAT3-CSN5 axis. Finally, GOLM1 knockdown was found to act in synergy with Lenvatinib in subcutaneous and orthotopic mouse model. Overall, these findings identify a mechanism of resistance to Lenvatinib treatment for HCC, highlight an effective predictive biomarker of Lenvatinib response in HCC and show that targeting GOLM1 may improve the clinical benefit of Lenvatinib.

The first structure of human Golm1 coiled coil domain reveals an unexpected tetramer and highlights its structural diversity

Golgi membrane protein 1 (Golm1), a transmembrane protein with diverse subcellular localizations, has garnered significant attention in recent years due to its strong association with the development and progression of liver diseases and numerous cancers. Interestingly, although Golm1 is a membrane protein, the C-terminal of Golm1, which contains a coiled coil domain and a flexible acid region, can also be detected in the plasma of patients with various liver diseases. Notably, the coiled coil domain of serum Golm1 is postulated to play a pivotal role in physiological and pathological functions. However, little is currently known about the structure of this coiled coil domain and the full-length protein, which may limit our understanding of Golm1. Therefore, this study aims to address this gap in knowledge and reports the first crystal structure of the coiled coil domain of Golm1 at a resolution of 2.28 Å. Meanwhile, we have also confirmed that the Golm1 coiled coil domain in solution can form tetramer. Our results reveal that Golm1 can form a novel tetrameric structure that differs from the previous reported dimeric structure Golm1 could assemble, which may provide novel insights into the diversity of physiological functions and pathological roles.

Development of an Eight-gene Prognostic Model for Overall Survival Prediction in Patients with Hepatocellular Carcinoma

BACKGROUND AND AIMS

The overall survival (OS) of hepatocellular carcinoma (HCC) remains dismal. Bioinformatic analysis of transcriptome data could identify patients with poor OS and may facilitate clinical decision. This study aimed to develop a prognostic gene model for HCC.

METHODS

GSE14520 was retrieved as a training set to identify differential expressed genes (DEGs) between tumor and adjacent liver tissues in HCC patients with different OS. A DEG-based prognostic model was then constructed and the TCGA-LIHC and ICGC-LIRI datasets were used to validate the model. The area under the receiver operating characteristic curve (AUC) and hazard ratio (HR) of the model for OS were calculated. A model-based nomogram was established and verified.

RESULTS

In the training set, differential expression analysis identified 80 genes dysregulated in oxidation-reduction and metabolism regulation. After univariate Cox and LASSO regression, eight genes (LPCAT1, DHRS1, SORBS2, ALDH5A1, SULT1C2, SPP1, HEY1 and GOLM1) were selected to build the prognostic model. The AUC for 1-, 3- and 5-year OS were 0.779, 0.736, 0.754 in training set and 0.693, 0.689, 0.693 in the TCGA-LIHC validation set, respectively. The AUC for 1- and 3-year OS were 0.767 and 0.705 in the ICGC-LIRI validation set. Multivariate analysis confirmed the model was an independent prognostic factor (training set: HR=4.422, p<0.001; TCGA-LIHC validation set: HR=2.561, p<0.001; ICGC-LIRI validation set: HR=3.931, p<0.001). Furthermore, a nomogram combining the model and AJCC stage was established and validated, showing increased OS predictive efficacy compared with the prognostic model (p=0.035) or AJCC stage (p<0.001).

CONCLUSIONS

Our eight-gene prognostic model and the related nomogram represent as reliable prognostic tools for OS prediction in HCC patients.

Golgi Phosphoprotein 73: The Driver of Epithelial-Mesenchymal Transition in Cancer

Golgi phosphoprotein 73 (GP73, also termed as GOLM1 or GOLPH2) is a glycosylated protein residing on cis-Golgi cisternae and highly expressed in various types of cancer tissues. Since GP73 is a secretory protein and detectable in serum derived from cancer patients, it has been regarded as a novel serum biomarker for the diagnosis of different cancers, especially hepatocellular carcinoma (HCC). However, the functional roles of GP73 in cancer development are still poorly understood. In recent years, it has been discovered that GP73 acts as a multifunctional protein-facilitating cancer progression, and strikingly, it has been identified as a leading factor promoting epithelial-mesenchymal transition (EMT) of cancer cells and causing cancer metastasis. In this review, we have overviewed the latest findings of the functional roles of GP73 in elevating cancer progression, especially in facilitating EMT and cancer metastasis through modulating expression, transactivation, and trafficking of EMT-related proteins. In addition, unsolved research fields of GP73 have been lightened, which might be helpful to elucidate the regulatory mechanisms of GP73 on EMT and provide potential approaches in therapeutics against cancer metastasis.

GOLM1 Drives Colorectal Cancer Metastasis by Regulating Myeloid-derived Suppressor Cells

Colorectal cancer (CRC) is the most common digestive neoplasms worldwide, metastasis and recurrence still account for the leading cause for the high mortality rate, but the exact mechanisms remain unclear. More and more evidence has indicated that the deregulation of GOLM1 plays a crucial role in cancer progression. Here, we reported a novel role of GOLM1 in promoting CRC metastasis. In this study, the expression of GOLM1 was detected in human CRC cohort. The function of GOLM1 in CRC metastasis was analyzed by in vivo cecum orthotopic model. We found that the expression of GOLM1 was significantly increased in CRC tissues than adjacent nontumor. Overexpression GOLM1 can promote CRC immune escape and metastasis by recruiting of myeloid-derived suppressor cells (MDSCs) at the same time. PF-04136309, a small molecule and specific inhibitor of CCR2 can largely suppressed GOLM1-mediated CRC metastasis. These results suggest that GOLM1 can promote CRC metastasis and is a prognostic biomarker in human CRC.

High GP73 Expression Correlates with Poor Response to Neoadjuvant Chemotherapy and Survival in Gastric Cancer: A Tissue Microarray Study

Golgi protein 73 (GP73) is a type II Golgi transmembrane protein which is overexpressed in several cancers, however, its role in gastric cancer is still unclear. The aim of this study is to investigate if high GP73 expression is associated with pathological tumor response to neoadjuvant chemotherapy and prognosis for patients with gastric cancer. A total of 348 patients with gastric cancer, who had undergone surgery between 1999 and 2011 were retrospectively reviewed, GP73 expression was examined in tumor tissues using tissue microarray and the correlations between its expression and pathological response to neoadjuvant chemotherapy as well as patients prognosis were analyzed. We found that GP73 expression was not associated with clinicopathologic features including tumor size, differentiation and TNM stage. High expression of GP73 was associated with less pathological tumor response to neoadjuvant chemotherapy and poor survival in gastric cancer, multivariate analysis showed GP73 expression was an independent predictive factor for pathological response to neoadjuvant chemotherapy and for prognosis in patients with gastric cancer. Our results suggest that GP73 expression correlates with the effect of neoadjuvant chemotherapy and is a promising biomarker to identify patients with poor prognosis.

Therapeutic Targeting of Golgi Phosphoprotein 2 (GOLPH2) with Armed Antibodies: A Preclinical Study of Anti-GOLPH2 Antibody Drug Conjugates in Lung and Colorectal Cancer Models of Patient Derived Xenografts (PDX)

BACKGROUND

Golgi phosphoprotein 2 (GOLPH2) has been shown to be involved in chronic inflammatory processes and carcinogenesis. GOLPH2 is prominently overexpressed in hepatocellular carcinoma, melanoma, glioblastoma, prostate, lung, and colorectal cancer. With a low and tightly regulated expression in non-malignant tissues, GOLPH2 has been proposed as an attractive target for cancer therapy. However, GOLPH2 is predominantly located intracellularly and when situated outside of the cell it is proteolytically cleaved and shed from the cell surface. Until now, GOLPH2 has been regarded as an "undruggable" target.

OBJECTIVE

We sought to create antibodies that specifically bind to GOLPH2 overexpressing tumor cells.

PATIENTS AND METHODS

Antibodies binding to membranous GOLPH2 despite shedding of the protein were generated from a scFV library screening. These antibodies target the part of GOLPH2 that remains at the cell surface after proteolytic cleavage. These antibodies were then tested in vitro and in vivo.

RESULTS

Two candidates (G2-1 and G2-2) showed target specific binding in vitro. Utilizing a tumor array (n = 128 tumors) with G2-2 and a reference antibody, a GOLPH2 expression scoring system was established. Rapid internalization of the antibodies was noted so this was exploited to deliver a toxic payload of pyrrolobenzodiazepine (PBD). In two patient-derived xenograft (PDX)-models, colorectal and lung cancer, the G2-2 antibody drug conjugate (ADC) displayed high efficacy with significant tumor responses (P = 0.001; P = 0.013) and improved survival (P = 0.0001; P = 0.0011) compared with controls.

CONCLUSIONS

Treatment with GOLPH2-directed antibodies induces durable responses in colorectal and lung cancer models. With a robust companion assay for GOLPH2 positivity at hand our findings prepare for the translation into a clinical trial.

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.

Selected Golgi-Localized Proteins and Carcinogenesis: What Do We Know?

The role of the Golgi apparatus in carcinogenesis still remains unclear. A number of structural and functional cis-, medial-, and trans-Golgi proteins as well as a complexity of metabolic pathways which they mediate may indicate a central role of the Golgi apparatus in the development and progression of cancer. Pleiotropy of cellular function of the Golgi apparatus makes it a "metabolic heart" or a relay station of a cell, which combines multiple signaling pathways involved in carcinogenesis. Therefore, any damage to or structural abnormality of the Golgi apparatus, causing its fragmentation and/or biochemical dysregulation, results in an up- or downregulation of signaling pathways and may in turn promote tumor progression, as well as local nodal and distant metastases. Three alternative or parallel models of spatial and functional Golgi organization within tumor cells were proposed: (1) compacted Golgi structure, (2) normal Golgi structure with its increased activity, and (3) the Golgi fragmentation with ministacks formation. Regardless of the assumed model, the increased activity of oncogenesis initiators and promoters with inhibition of suppressor proteins results in an increased cell motility and migration, increased angiogenesis, significantly activated trafficking kinetics, proliferation, EMT induction, decreased susceptibility to apoptosis-inducing factors, and modulating immune response to tumor cell antigens. Eventually, this will lead to the increased metastatic potential of cancer cells and an increased risk of lymph node and distant metastases. This chapter provided an overview of the current state of knowledge of selected Golgi proteins, their role in cytophysiology as well as potential involvement in tumorigenesis.

A Nonsynonymous Variant in the GOLM1 Gene in Cutaneous Malignant Melanoma

Background

Statistically significant linkage of melanoma to chromosome 9q21 was previously reported in a Danish pedigree resource and independently confirmed in Utah high-risk pedigrees, indicating strong evidence that this region contains a melanoma predisposition gene.

Methods

Whole-exome sequencing of pairs of related melanoma case subjects from two pedigrees with evidence of 9q21 linkage was performed to identify the responsible predisposition gene. Candidate variants were tested for association with melanoma in an independent set of 454 unrelated familial melanoma case subjects and 396 unrelated cancer-free control subjects from Utah, and 1534 melanoma case subjects and 1146 noncancer control subjects from Texas (MD Anderson) via a two-sided Fisher exact test.

Results

A rare nonsynonymous variant in Golgi Membrane Protein 1 (GOLM1), rs149739829, shared in two hypothesized predisposition carriers in one linked pedigree was observed. Segregation of this variant in additional affected relatives of the index carriers was confirmed. A statistically significant excess of carriers of the variant was observed among Utah case subjects and control subjects (odds ratio [OR] = 9.81, 95% confidence interval [CI] = 8.35 to 11.26, P < .001) and statistically significantly confirmed in Texas case subjects and control subjects (OR = 2.45, 95% CI = 1.65 to 3.25, P = .02).

Conclusion

These findings support GOLM1 as a candidate melanoma predisposition gene.

Research progress on GP73 in malignant tumors

Malignant cancer is one of the most serious diseases that currently endanger human health. As most tumors are diagnosed at an advanced stage, the current treatments show poor therapeutic efficacy, and the patients have poor prognosis. However, a 5-year survival rate higher than 80% could be achieved if tumors are diagnosed at an early stage. Therefore, early diagnosis and treatment play important roles in the prevention and treatment of malignant tumors, and serum tumor markers are important for the early diagnosis of malignant cancers. Recent studies have shown that GP73, a transmembrane protein, has greater diagnostic value in primary liver cancer than in other types of cancers, and research on the regulation of GP73 expression has unveiled broad prospects in anticancer targeted therapy. Thus, GP73, as a new tumor marker, deserves further study.

Overexpression of Golgi Phosphoprotein 2 Is Associated With Poor Prognosis in Oral Squamous Cell Carcinoma

OBJECTIVES

The aims of this study were to investigate the relationship between Golgi phosphoprotein 2 (GOLPH2) and oral squamous cell carcinoma (OSCC) and explore the clinical significance of GOLPH2 in OSCC.

METHODS

Tissue microarrays from human OSCC samples were stained for GOLPH2 expression and clinicopathologic features. Kaplan-Meier analysis was used to compare the survival of patients with high GOLPH2 expression and patients with low GOLPH2 expression.

RESULTS

We found GOLPH2 is highly expressed in OSCC tissue, and the GOLPH2 expression in metastatic lymph nodes is higher than in tumor tissue. Our data indicate that patients with higher GOLPH2 expression have poor overall survival compared with those with lower GOLPH2 expression. This study demonstrated that GOLPH2 was associated with CD44, SOX2, Slug, B7-H3, B7-H4, TIM3, and VISTA.

CONCLUSIONS

These findings suggest GOLPH2 is a potential marker for estimating the patient's prognosis and may be a target for molecular-targeted therapy against OSCC.

PDGFA/PDGFRα-regulated GOLM1 promotes human glioma progression through activation of AKT

BACKGROUND

Golgi Membrane Protein 1 (GOLM1), a protein involved in the trafficking of proteins through the Golgi apparatus, has been shown to be oncogenic in a variety of human cancers. Here, we examined the role of GOLM1 in the development of human glioma.

METHODS

qRT-PCR, immunohistochemistry, and western blot analysis were performed to evaluate GOLM1 levels in cell lines and a cohort of primary human glioma and non-neoplastic brain tissue samples. Glioma cell lines were modified with lentiviral constructs expressing short hairpin RNAs targeting GOLM1 or overexpressing the protein to assess function in proliferation, viability, and migration and invasion in vitro using EdU, CCK8, clone-forming, Transwell assays, 3D tumor spheroid invasion assay and in vivo in orthotopic implantations. Protein lysates were used to screen a membrane-based antibody array to identify kinases mediated by GOLM1. Specific inhibitors of PDGFRα (AG1296) and AKT (MK-2206) were used to examine the regulation of PDGFA/PDGFRα on GOLM1 and the underlying pathway respectively.

RESULTS

qRT-PCR, immunohistochemistry and western blot analysis revealed GOLM1 expression to be elevated in glioma tissues and cell lines. Silencing of GOLM1 attenuated proliferation, migration, and invasion of U251, A172 and P3#GBM (primary glioma) cells, while overexpression of GOLM1 enhanced malignant behavior of U87MG cells. We further demonstrated that activation of AKT is the driving force of GOLM1-promoted glioma progression. The last finding of this research belongs to the regulation of PDGFA/PDGFRα on GOLM1, while GOLM1 was also a key element of PDGFA/PDGFRα-mediated activation of AKT, as well as the progression of glioma cells.

CONCLUSIONS

PDGFA/PDGFRα-regulated GOLM1 promotes glioma progression possibly through activation of a key signaling kinase, AKT. GOLM1 interference may therefore provide a novel therapeutic target and improve the efficacy of glioma treatment, particularly in the case of the proneural molecular subtype of human glioma.

GP73 regulates Hepatic Steatosis by enhancing SCAP-SREBPs interaction

Elevated Golgi phosphoprotein 2 (GP73, also known as GOLPH2 or GOLM1) expression in serum and liver, which can be induced by viral infection and cytokine treatments, is intimately connected with liver disease, including acute hepatitis, cirrhosis and hepatocellular carcinoma (HCC). However, its pathogenic roles in hepatic diseases have never been clarified in detail. Here, we showed that the upregulated GP73 is indispensable for SREBPs activation and lipogenesis. Notably, GP73 overexpression enhanced SCAP-SREBPs binding and its Golgi trafficking even under cholesterol sufficiency. Consistent with these functional findings, GP73 blockage could alleviate tunicamycin-induced liver steatosis by reducing SREBPs activation. A significant positive correlation of GP73 with genes in lipid metabolism pathway was also identified in liver cancer based on data from The Cancer Genome Atlas (TCGA) dataset. Our findings revealed previously unrecognized role of GP73 in lipid metabolism.

Association of GOLPH2 expression with survival in non-small-cell lung cancer: clinical implications and biological validation

AIM

We investigated the role of GOLPH2 in non-small-cell lung cancer (NSCLC).

METHODS

We analyzed the relationship between the expression of GOLPH2 and the clinical pathological characteristics of patients with NSCLC. The function of GOLPH2 in NSCLC cell lines was also explored through overexpression and knockdown studies.

RESULTS

The positive expression rate of GOLPH2 protein in NSCLC tissue was higher than that of normal lung tissue. We found that positive GOLPH2 expression was closely associated with unfavorable features of patients with NSCLC. The GOLPH2 expression was an independent predictor of the prognosis of patients with NSCLC. That GOLPH2 can promote the proliferation and invasion of NSCLC cells.

CONCLUSION

The GOLPH2 is a novel marker for NSCLC.

Golgi-Related Proteins GOLPH2 (GP73/GOLM1) and GOLPH3 (GOPP1/MIDAS) in Cutaneous Melanoma: Patterns of Expression and Prognostic Significance

GOLPH2 and GOLPH3 are Golgi-related proteins associated with aggressiveness and progression of a number of cancers. Their prognostic significance in melanoma has not yet been analyzed. We performed immunohistochemical analysis for GOLPH2 and GOLPH3 in 20 normal skin, 30 benign nevi and 100 primary melanoma tissue samples and evaluated their expression in three compartments: cancer cells, tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs). High levels of both proteins in melanoma cells were associated with characteristics of aggressive disease, and shorter disease-free survival (DFS) and cancer-specific overall survival (CSOS). On the contrary, increased numbers of GOLPH2-positive and GOLPH3-positive TAMs were observed in thinner, non-ulcerated tumors, with brisk lymphocytic reaction and absent lymphangioinvasion. Distant metastases were not observed among patients with high numbers of GOLPH2-positive TAMs. Increased expression of either protein in TAMs was related to prolonged CSOS and DFS. Similarly, GOLPH3-expressing CAFs were more frequent in thin melanomas with low mitotic rate, without ulceration and lymphangioinvasion. Moreover, increased GOLPH3-positive CAFs correlated with the absence of regional or distant metastases, and with longer CSOS and DFS. GOLPH2 expression was not observed in CAFs. Our results suggest that GOLPH2 and GOLPH3 play a role in melanoma progression and are potential targets for molecular-based therapies.