Terbinafine prevents colorectal cancer growth by inducing dNTP starvation and reducing immune suppression.

Existing evidence indicates that gut fungal dysbiosis might play a key role in the pathogenesis of colorectal cancer (CRC). We sought to explore whether reversing the fungal dysbiosis by terbinafine, an approved antifungal drug, might inhibit the development of CRC. A population-based study from Sweden identified a total of 185 patients who received terbinafine after their CRC diagnosis and found that they had a decreased risk of death (hazard ratio = 0.50) and metastasis (hazard ratio = 0.44) compared with patients without terbinafine administration. In multiple mouse models of CRC, administration of terbinafine decreased the fungal load, the fungus-induced myeloid-derived suppressor cell (MDSC) expansion, and the tumor burden. Fecal microbiota transplantation from mice without terbinafine treatment reversed MDSC infiltration and partially restored tumor proliferation. Mechanistically, terbinafine directly impaired tumor cell proliferation by reducing the ratio of nicotinamide adenine dinucleotide phosphate (NADP+) to reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), suppressing the activity of glucose-6-phosphate dehydrogenase (G6PD), resulting in nucleotide synthesis disruption, deoxyribonucleotide (dNTP) starvation, and cell-cycle arrest. Collectively, terbinafine can inhibit CRC by reversing fungal dysbiosis, suppressing tumor cell proliferation, inhibiting fungus-induced MDSC infiltration, and restoring antitumor immune response.

TRIM59 predicts poor prognosis and promotes pancreatic cancer progression via the PI3K/AKT/mTOR-glycolysis signaling axis.

Aberrant expression of the tripartite motif containing 59 (TRIM59) has been reported to participate in the development and progression of various human cancers. However, its expression pattern and cellular roles in pancreatic cancer (PC) remains unclear. In our study, we found that TRIM59 expression was significantly increased in PC tissues and was positively correlated with several malignant behaviors and poor overall survival of PC patients based on bioinformatics analysis and immunohistochemistry staining. Functionally, small interfering RNA-mediated TRIM59 depletion inhibited cell proliferation and migration in vitro, while TRIM59 overexpression promoted cell proliferation and migration in vitro and drove tumor growth and liver metastasis in vivo. Mechanically, TRIM59 was found to enhance glycolysis through activating the PI3K/AKT/mTOR pathway, ultimately contributing to PC progression. Taken together, our results demonstrate that TRIM59 may be a potential predictor for PC and promotes PC progression via the PI3K/AKT/mTOR-glycolysis signaling pathway, which establishes the rationale for targeting the TRIM59-related pathways to treat PC.

GABRP regulates chemokine signalling, macrophage recruitment and tumour progression in pancreatic cancer through tuning KCNN4-mediated Ca2+ signalling in a GABA-independent manner.

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related death worldwide. Neurotransmitter-initiated signalling pathway is profoundly implicated in tumour initiation and progression. Here, we investigated whether dysregulated neurotransmitter receptors play a role during pancreatic tumourigenesis. METHODS: The Cancer Genome Atlas and Gene Expression Omnibus datasets were used to identify differentially expressed neurotransmitter receptors. The expression pattern of gamma-aminobutyric acid type A receptor pi subunit (GABRP) in human and mouse PDAC tissues and cells was studied by immunohistochemistry and western blot analysis. The in vivo implications of GABRP in PDAC were tested by subcutaneous xenograft model and lung metastasis model. Bioinformatics analysis, transwell experiment and orthotopic xenograft model were used to identify the in vitro and in vivo effects of GABRP on macrophages in PDAC. ELISA, co-immunoprecipitation, proximity ligation assay, electrophysiology, promoter luciferase activity and quantitative real-time PCR analyses were used to identify molecular mechanism. RESULTS: GABRP expression was remarkably increased in PDAC tissues and associated with poor prognosis, contributed to tumour growth and metastasis. GABRP was correlated with macrophage infiltration in PDAC and pharmacological deletion of macrophages largely abrogated the oncogenic functions of GABRP in PDAC. Mechanistically, GABRP interacted with KCNN4 to induce Ca2+ entry, which leads to activation of nuclear factor κB signalling and ultimately facilitates macrophage infiltration by inducing CXCL5 and CCL20 expression. CONCLUSIONS: Overexpressed GABRP exhibits an immunomodulatory role in PDAC in a neurotransmitter-independent manner. Targeting GABRP or its interaction partner KCNN4 may be an effective therapeutic strategy for PDAC.

Overexpression of Rac GTPase Activating Protein 1 Contributes to Proliferation of Cancer Cells by Reducing Hippo Signaling to Promote Cytokinesis.

BACKGROUND & AIMS: Agents designed to block or alter cytokinesis can kill or stop proliferation of cancer cells. We aimed to identify cytokinesis-related proteins that are overexpressed in hepatocellular carcinoma (HCC) cells and might be targeted to slow liver tumor growth. METHODS: Using the Oncomine database, we compared the gene expression patterns in 16 cancer microarray datasets and assessed gene enrichment sets using gene ontology. We performed immunohistochemical analysis of an HCC tissue microarray and identified changes in protein levels that are associated with patient survival times. Candidate genes were overexpressed or knocked down with small hairpin RNAs in SMMC7721, MHCC97H, or HCCLM3 cell lines; we analyzed their proliferation, viability, and clone-formation ability and their growth as subcutaneous or orthotopic xenograft tumors in mice. We performed microarray analyses to identify alterations in signaling pathways and immunoblot and immunofluorescence assays to detect and localize proteins in tissues. Yeast 2-hybrid screens and mass spectrometry combined with co-immunoprecipitation experiments were used to identify binding proteins. Protein interactions were validated with co-immunoprecipitation and proximity ligation assays. Chromatin immunoprecipitation, promoter luciferase activity, and quantitative real-time polymerase chain reaction analyses were used to identify factors that regulate transcription of specific genes. RESULTS: The genes that were most frequently overexpressed in different types of cancer cells were involved in cell division processes. We identified 3 cytokinesis-regulatory proteins among the 10 genes most frequently overexpressed by all cancer cell types. Rac GTPase activating protein 1 (RACGAP1) was the cytokinesis-regulatory protein that was most highly overexpressed in multiple cancers. Increased expression of RACGAP1 in tumor tissues was associated with shorter survival times of patients with cancer. Knockdown of RACGAP1 in HCC cells induced cytokinesis failure and cell apoptosis. In microarray analyses, we found knockdown of RACGAP1 in SMMC7721 cells to reduce expression of genes regulated by yes-associated protein (YAP) and WW domain containing transcription regulator 1 (WWTR1 or TAZ). RACGAP1 reduced activation of the Hippo pathway in HCC cells by increasing activity of RhoA and polymerization of filamentous actin. Knockdown of YAP reduced phosphorylation of RACGAP1 and redistribution at the anaphase central spindle. We found transcription of the translocated promoter region, nuclear basket protein (TPR) to be regulated by YAP and coordinately expressed with RACGAP1 to promote proliferation of HCC cells. TPR redistributed upon nuclear envelope breakdown and formed complexes with RACGAP1 during mitosis. Knockdown of TPR in HCC cells reduced phosphorylation of RACGAP1 by aurora kinase B and impaired their redistribution at the central spindle during cytokinesis. STAT3 activated transcription of RACGAP in HCC cells. CONCLUSIONS: In an analysis of gene expression patterns of multiple tumor types, we found RACGAP1 to be frequently overexpressed, which is associated with shorter survival times of patients. RACGAP1 promotes proliferation of HCC cells by reducing activation of the Hippo and YAP pathways and promoting cytokinesis in coordination with TPR.

Aberrant upregulation of KLK10 promotes metastasis via enhancement of EMT and FAK/SRC/ERK axis in PDAC.

Pancreatic Ductal Adenocarcinoma (PADC) metastasis is the leading cause of morality of this severe malignant tumor. Proteases are key players in the degradation of extracellular matrix which promotes the cascade of tumor metastasis. As a kind of serine proteases, the kallikrein family performs vital function on the cancer proteolysis scene, which have been proved in diverse malignant tumors. However, the specific member of kallikrein family and its function in PDAC remain unexplored. In this study, by data mining of GEO datasets, we have identified KLK10 is upregulated gene in PDAC. We found that KLK10 was significantly overexpressed in tissues of pancreatic intraepithelial neoplasia (PanIN) and PDAC from Pdx1-Cre; LSL-KrasG12D/+ mice (KC) and Pdx1-Cre; LSL-KrasG12D/+; LSL-Trp53R172H/+ mice (KPC) by immunohistochemical analysis. Moreover, KLK10 is extremely elevated in the PDAC tissues, especially that from the PDAC patients with lymphatic and distant metastasis. Aberrant KLK10 expression is significantly correlated with poor prognosis and shorter survival by univariable and multivariable analysis. Functionally, knockdown of KLK10 observably inhibits invasion and metastatic phenotype of PDAC cells in vitro and metastasis in vivo. In addition, blockade of KLK10 attenuates epithelial-mesenchymal transition and activation of FAK-SRC-ERK signaling, which explains the mechanism of KLK10 in promoting metastasis. Collectively, KLK10 should be considered as a promising biomarker for diagnosis and potential target for therapy in PDAC.

NLRP1 inhibits lung adenocarcinoma growth through mediating mitochondrial dysregulation in an inflammasome-independent manner.

NLRP1, the first identified inflammasome-forming sensor, is thought to be involved in cancer, yet its definite function in lung adenocarcinoma (LUAD) remains unclear. Herein, we explored the expression and function of NLRP1 in LUAD. Decreased NLRP1 expression was identified in LUAD, which was associated with a poor prognosis. Overexpression of NLRP1 inhibited tumor growth in vitro and in vivo. Mechanically, this effect was observed regardless of inflammasome activation. Further studies revealed that overexpression of NLRP1 downregulated the phosphorylation of DRP1 and promoted mitochondrial fusion, which was mediated by inhibition of NF-κB activity. NF-κB agonist could neutralize the effect of NLRP1 on mitochondrial dynamics. In addition, LUAD sensitivity to cisplatin was enhanced by decreased mitochondrial fission resulting from up-regulated NLRP1. In conclusion, our findings demonstrated an unexpected role of NLRP1 in LUAD by modulating mitochondrial activities, which provides strong evidence for its potential in LUAD treatment.

CCBE1 promotes mitochondrial fusion by inhibiting the TGFß-DRP1 axis to prevent the progression of hepatocellular carcinoma.

The extracellular matrix (ECM), as an important component of the tumor microenvironment, exerts various roles in tumor formation. Mitochondrial dynamic disorder is closely implicated in tumorigenesis, including hyperfission in HCC. We aimed to determine the influence of the ECM-related protein CCBE1 on mitochondrial dynamics in HCC. Here, we found that CCBE1 was capable of promoting mitochondrial fusion in HCC. Initially, CCBE1 expression was found to be significantly downregulated in tumors compared with nontumor tissues, which resulted from hypermethylation of the CCBE1 promoter in HCC. Furthermore, CCBE1 overexpression or treatment with recombinant CCBE1 protein dramatically inhibited HCC cell proliferation, migration, and invasion in vitro and in vivo. Mechanistically, CCBE1 functioned as an inhibitor of mitochondrial fission by preventing the location of DRP1 on mitochondria through inhibiting its phosphorylation at Ser616 by directly binding with TGFßR2 to inhibit TGFß signaling activity. In addition, a higher percentage of specimens with higher DRP1 phosphorylation was present in patients with lower CCBE1 expression than in patients with higher CCBE1 expression, which further confirmed the inhibitory effect of CCBE1 on DRP1 phosphorylation at Ser616. Collectively, our study highlights the crucial roles of CCBE1 in mitochondrial homeostasis, suggesting strong evidence for this process as a potential therapeutic strategy for HCC.

Spatiotemporal quantification of metastatic tumour cell growth and distribution in lymph nodes by whole-mount tissue 3D imaging.

Lymph nodes (LNs) are a common site of metastasis in many solid cancers. Tumour cells can migrate to LNs for further metastatic colonization of distant organs, indicating poor prognosis and requiring different clinical interventions. The histopathological diagnostic methods currently used to detect clinical lymph node metastasis (LNM) have limitations, such as incomplete visualization. To obtain a complete picture of metastatic LNs on the spatial and temporal scales, we used ultimate 3D imaging of solvent-cleared organs (uDISCO) and 3D rapid immunostaining. MC38 cells labelled with EGFP were injected into the left footpads of C57BL/6 mice. Draining lymph nodes (DLNs) harvested from these mice were cleared using the uDISCO method. Metastatic colorectal cancer (CRC) cells in various regions of DLNs from mice at different time points were quantified using 3D imaging of whole-mount tissue. Several stages of tumour cell growth and distribution in LNs were identified: 1) invasion of lymphatic vessels (LVs) and blood vessels (BVs); 2) dispersion outside LVs and BVs for proliferation and expansion; and 3) re-entry into BVs and efferent lymphatic vessels (ELVs) for further distant metastasis. Moreover, these data demonstrated that mouse fibroblast cells (MFCs) could not only promote LNM of tumour cells but also metastasize to LNs together with tumour cells, thus providing a "soil" for tumour cell colonization. In conclusion, 3D imaging of whole-mount tissue and spatiotemporal analysis of LNM may collectively constitute an auxiliary method to improve the accuracy of clinical LNM detection.

Proteomic screening of potential N-glycoprotein biomarkers for colorectal cancer by TMT labeling combined with LC-MS/MS.

BACKGROUND AND AIMS: Colorectal cancer (CRC) is part of the most widespread malignant tumors. At present, colonoscopy is a routine procedure in the diagnosis of CRC, but it is traumatic. Carcinoembryonic antigen, CA199, and CA242 are common serum markers for the diagnosis of CRC; however, they do not demonstrate satisfactory specificity and sensitivity for the diagnosis of CRC. Hence, Now it is necessary to screen many valuable serum biomarkers for CRC, proteomics methods have been used to investigate PTMs such as glycosylation of proteins with prominent roles in the occurrence and development of tumors. METHODS: This study screens altering glycosylated proteins of CRC tissues using LC-MS/MS quantitative glycoproteomics, and then these candidate biomarkers for CRC are further validated by serum glycoproteomics. RESULTS: The results of glycoproteomics in CRC tissues show that the abundance of 160 and 79 glycerogelatin proteins was obviously upregulated and downregulated compared with their adjacent tissues(P < 0.05). Bioinformatics analysis suggests that these molecules are mainly involved in many biological processes, including skeletal system development, collagen fibril organization, and receptor-mediated endocytosis. Results of serum glycoproteomics show that the changing trends of 2 protein glycosylation were consistent with MS results of CRC tissues, including ICAM1and APMAP. Areas under the ROC curve (AUC) results confirm that ICAM1and APMAP as early immune diagnosis markers of CRC has excellent sensitivity and specificity. CONCLUSION: The ICAM1 and APMAP may serve as a potential tumor marker for CRC.

BDNF expression in GISTs predicts poor prognosis when associated with PD-L1 positive tumor-infiltrating lymphocytes.

Substantial evidence indicates that brain-derived neurotrophic factor (BDNF) plays an important role in tumorigenesis, in addition to its primary role in neuronal activity. Gastrointestinal stromal tumors (GISTs), which are the most common mesenchymal neoplasms of the gastrointestinal tract, contain multiple types of tumor-infiltrating lymphocytes (TILs) that express relevant immune checkpoint proteins. However, no data have been reported on the role of BDNF in GISTs. This study aimed to investigate the expression pattern and prognostic value of BDNF in GIST patients with different degrees of risk, as well as the relationship between BDNF expression and immune checkpoints. Immunohistochemistry (IHC) demonstrated that higher BDNF expression was more likely to be present in high-risk patients and suggested a poor prognosis. A similar phenomenon was demonstrated in plasma. Even more interesting was that a positive correlation was present between BDNF and PD-L1+ expression on TILs. Moreover, high BDNF expression levels in combination with a high PD-L1+ TIL count predict extremely poor survival. The combination of BDNF expression and TIL PD-L1+ expression as a single biomarker was a powerful significant independent predictor of prognosis. Taken together, BDNF expression may serve as a significant prognostic factor, as the combination of BDNF expression and the PD-L1+ TIL subset led to superior prediction of GIST prognosis. Furthermore, our research coupled a neurotrophin with immunity, which provides novel evidence of neural and immune regulation in a clinical study of GIST.

Identification of a subset of immunosuppressive P2RX1-negative neutrophils in pancreatic cancer liver metastasis.

The immunosuppressive microenvironment that is shaped by hepatic metastatic pancreatic ductal adenocarcinoma (PDAC) is essential for tumor cell evasion of immune destruction. Neutrophils are important components of the metastatic tumor microenvironment and exhibit heterogeneity. However, the specific phenotypes, functions and regulatory mechanisms of neutrophils in PDAC liver metastases remain unknown. Here, we show that a subset of P2RX1-negative neutrophils accumulate in clinical and murine PDAC liver metastases. RNA sequencing of murine PDAC liver metastasis-infiltrated neutrophils show that P2RX1-deficient neutrophils express increased levels of immunosuppressive molecules, including PD-L1, and have enhanced mitochondrial metabolism. Mechanistically, the transcription factor Nrf2 is upregulated in P2RX1-deficient neutrophils and associated with PD-L1 expression and metabolic reprogramming. An anti-PD-1 neutralizing antibody is sufficient to compromise the immunosuppressive effects of P2RX1-deficient neutrophils on OVA-activated OT1 CD8+ T cells. Therefore, our study uncovers a mechanism by which metastatic PDAC tumors evade antitumor immunity by accumulating a subset of immunosuppressive P2RX1-negative neutrophils.

CTHRC1 promotes liver metastasis by reshaping infiltrated macrophages through physical interactions with TGF-ß receptors in colorectal cancer.

Metastasis is a major cause of cancer-related deaths. Tumor-intrinsic properties can determine whether tumor metastasis occurs or not. Here, by comparing the gene expression patterns in primary colorectal cancer (CRC) patients with or without metastasis, we found that Collagen Triple Helix Repeat Containing 1 (CTHRC1) in primary CRC served as a metastasis-associated gene. Animal experiments verified that CTHRC1 secreted by CRC cells promoted hepatic metastasis, which was closely correlated with macrophage infiltration. Depletion of macrophages by liposomal clodronate largely abolished the promoting effect of CTHRC1 on CRC liver metastasis. Furthermore, we demonstrated that CTHRC1 modulated macrophage polarization to M2 phenotypes through TGF-ß signaling. A mechanistic study revealed that CTHRC1 bound directly to TGF-ß receptor II and TGF-ß receptor III, stabilized the TGF-ß receptor complex, and activated TGF-ß signaling. The combination treatment of CTHRC1 monoclonal antibody and anti-PD-1 blocking antibody effectively suppressed CRC hepatic metastasis. Taken together, our data demonstrated that CTHRC1 is an intrinsic marker of CRC metastasis and further revealed that CTHRC1 promoted CRC liver metastasis by reshaping infiltrated macrophages through TGF-ß signaling, suggesting that CTHRC1 could be a potential biomarker for the early prediction of and a therapeutic target of CRC hepatic metastasis.

Single-cell RNA sequencing reveals that targeting HSP90 suppresses PDAC progression by restraining mitochondrial bioenergetics.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, which lacks effective treatment strategies. There is an urgent need for the development of new strategies for PDAC therapy. The genetic and phenotypic heterogeneity of PDAC cancer cell populations poses further challenges in the clinical management of PDAC. In this study, we performed single-cell RNA sequencing to characterize PDAC tumors from KPC mice. Functional studies and clinical analysis showed that PDAC cluster 2 cells with highly Hsp90 expression is much more aggressive than the other clusters. Genetic and pharmacologic inhibition of Hsp90 impaired tumor cell growth both in vitro and in vivo. Further mechanistic study revealed that HSP90 inhibition disrupted the interaction between HSP90 and OPA1, leading to a reduction in mitochondrial cristae amount and mitochondrial energy production. Collectively, our study reveals that HSP90 might be a potential therapeutic target for PDAC.

MPC1 Deficiency Promotes CRC Liver Metastasis via Facilitating Nuclear Translocation of ß-Catenin.

Accumulating evidence has pointed out that metastasis is the leading cause of death in several malignant tumor, including CRC. During CRC, metastatic capacity is closely correlated with reprogrammed energy metabolism. Mitochondrial Pyruvate Carrier 1 (MPC1), as the carrier of transporting pyruvate into mitochondria, linked the glycolysis and TCA cycle, which would affect the energy production. However, the specific role of MPC1 on tumor metastasis in CRC remains unexplored. Here, by data mining of genes involved in pyruvate metabolism using the TCGA dataset, we found that MPC1 was significantly downregulated in CRC compared to nontumor tissues. Similar MPC1 expression pattern was also found in multiple GEO datasets. IHC staining in both human sample and AOM/DSS induced mouse CRC model revealed significant downregulation of MPC1. What is more, we found that MPC1 expression was gradually decreased in normal tissue, primary CRC, and metastasis CRC. Additionally, poor prognosis emerged in the MPC1 low expression patients, especially in patients with metastasis. Following, functional tests showed that MPC1 overexpression inhibited the motility of CRC cells in vitro and MPC1 silencing enhanced liver metastases in vivo. Furthermore, we uncovered that decreased MPC1 activated the Wnt/ß-catenin pathway by promoting nuclear translocation of ß-catenin to mediate the expression of MMP7, E-cadherin, Snail1, and myc. Collectively, our data suggest that MPC1 has the potential to be served as a promising biomarker for diagnosis and a therapeutic target in CRC.

Perineural Invasion Reprograms the Immune Microenvironment through Cholinergic Signaling in Pancreatic Ductal Adenocarcinoma.

Perineural invasion is a common feature of pancreatic ductal adenocarcinoma (PDAC). Here, we investigated the effect of perineural invasion on the microenvironment and how this affects PDAC progression. Transcriptome expression profiles of PDAC tissues with different perineural invasion status were compared, and the intratumoral T-cell density and levels of neurotransmitters in these tissues were assessed. Perineural invasion was associated with impaired immune responses characterized by decreased CD8+ T and Th1 cells, and increased Th2 cells. Acetylcholine levels were elevated in severe perineural invasion. Acetylcholine impaired the ability of PDAC cells to recruit CD8+ T cells via HDAC1-mediated suppression of CCL5. Moreover, acetylcholine directly inhibited IFNγ production by CD8+ T cells in a dose-dependent manner and favored Th2 over Th1 differentiation. Furthermore, hyperactivation of cholinergic signaling enhanced tumor growth by suppressing the intratumoral T-cell response in an orthotopic PDAC model. Conversely, blocking perineural invasion with bilateral subdiaphragmatic vagotomy in tumor-bearing mice was associated with an increase in CD8+ T cells, an elevated Th1/Th2 ratio, and improved survival. In conclusion, perineural invasion-triggered cholinergic signaling favors tumor growth by promoting an immune-suppressive microenvironment characterized by impaired CD8+ T-cell infiltration and a reduced Th1/Th2 ratio. SIGNIFICANCE: These findings provide a promising therapeutic strategy to modulate the immunosuppressive microenvironment of pancreatic ductal adenocarcinoma with severe perineural invasion.

NPTX2 promotes colorectal cancer growth and liver metastasis by the activation of the canonical Wnt/ß-catenin pathway via FZD6.

Accumulating evidence from clinical and epidemiological studies has highlighted the close correlation between the individual risk of cancer and nervous system diseases. The expression of neuronal pentraxin 2 (NPTX2) is absent in Alzheimer's disease, anxiety, and depression. Herein, we found that NPTX2 mRNA and protein expression was significantly upregulated in colorectal carcinoma (CRC). NPTX2 expression level gradually increased with CRC progression and was closely associated with poor prognosis. In vitro and in vivo studies demonstrated that NPTX2 promoted CRC proliferation and metastasis through the activation of the Wnt/ß-catenin signaling pathway. As NPTX2 receptors are absent on CRC cells, NPTX2 was shown to physically interact with frizzled class receptor 6 (FZD6) to promote ß-catenin translocation into the cell nucleus, resulting in an increase in the expression of MYC, cyclin D1, snail, and N-cadherin along with a decrease in the expression of E-cadherin. Knockdown of FZD6 expression with a small-interfering RNA almost completely reversed the proliferative effects of NPTX2 on CRC development. In conclusion, NPTX2, a molecule related to nervous system diseases, promotes CRC cell proliferation and metastasis through the activation of the Wnt/ß-catenin pathway via direct interaction with FZD6.

Autocrine CTHRC1 activates hepatic stellate cells and promotes liver fibrosis by activating TGF-ß signaling.

BACKGROUND: Hepatic fibrosis is caused by chronic liver injury and may progress toward liver cirrhosis, and even hepatocellular carcinoma. However, current treatment is not satisfactory. Therefore, there is a mandate to find novel therapeutic targets to improve therapy, and biomarkers to monitor therapeutic response. METHODS: Liver fibrosis was induced by carbon tetrachloride (CCl4) or thioacetamide (TAA) in wild type (WT) or CTHRC1-/- mice, followed by immunofluorescence and immunohistochemical analyses. CTHRC1 monoclonal antibody (mAb) was used to abrogate the effect of CTHRC1 in vitro and in vivo. RESULTS: Here, we reported that collagen triple helix repeat containing 1 (CTHRC1), a secreted protein derived from hepatic stellate cells (HSCs), was significantly up-regulated in fibrotic liver tissues. CTHRC1 promoted HSCs transformation from a quiescent to an activated state, and enhanced migratory or contractile capacities of HSCs by activating TGF-ß signaling. Meanwhile, CTHRC1 competitively bound to Wnt noncononical receptor and promoted the contractility but not activation of HSCs. CCl4 or TAA-induced liver fibrosis was attenuated in CTHRC-/- mice compared with littermate control, while a monoclonal antibody of CTHRC1 suppressed liver fibrosis in WT mice treated with CCl4 or TAA. INTERPRETATION: We demonstrated that CTHRC1 is a new regulator of liver fibrosis by modulating TGF-ß signaling. Targeting CTHRC1 could be a promising therapeutic approach, which can suppress TGF-ß signaling and avoid the side effects caused by directly targeting TGF-ß. CTHRC1 could also be a potential biomarker for monitoring response to anti-fibrotic therapy. FUND: This study was supported by the National Natural Science Foundation of China (ID 81672358, 81871923, 81872242, 81802890), the Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (ID 20181708), the Natural Science Foundation of Shanghai (ID 17ZR1428300, 18ZR1436900), and Shanghai Municipal Health Bureau (ID 2018BR32). The funders did not play a role in manuscript design, data collection, data analysis, interpretation nor writing of the manuscript.

GPAA1 promotes gastric cancer progression via upregulation of GPI-anchored protein and enhancement of ERBB signalling pathway.

BACKGROUND: Gastric cancer is one of the deadliest malignant tumours, with a high incidence in China, and is regulated by aberrantly overexpressed oncogenes. However, existing therapies are insufficient to meet patients' needs; thus, the identification of additional therapeutic targets and exploration of the underlying mechanism are urgently needed. GPAA1 is the subunit of the GPI transamidase that transfers the GPI anchor to proteins within the ER. The functional impacts of increased expression levels of GPAA1 in human cancers are not well understood. METHODS: Data mining was performed to determine the pattern of GPAA1 expression and the reason for its overexpression in tumour and adjacent normal tissues. In vitro and in vivo experiments evaluating proliferation and metastasis were performed using cells with stable deletion or overexpression of GPAA1. A tissue microarray established by the Ren Ji Hospital was utilized to analyse the expression profile of GPAA1 and its correlation with prognosis. Western blotting, an in situ proximity ligation assay, and co-immunoprecipitation (co-IP) were performed to reveal the mechanism of GPAA1 in gastric cancer. RESULTS: GPAA1 was a markedly upregulated oncogene in gastric cancer due to chromosomal amplification. GPAA1 overexpression was confirmed in specimens from the Ren Ji cohort and was associated with ERBB2 expression, predicting unsatisfactory patient outcomes. Aberrantly upregulated GPAA1 dramatically contributed to cancer growth and metastasis in in vitro and in vivo studies. Mechanistically, GPAA1 enhanced the levels of metastasis-associated GPI-anchored proteins to increase tumour metastasis and intensified lipid raft formation, which consequently promoted the interaction between EGFR and ERBB2 as well as downstream pro-proliferative signalling. CONCLUSIONS: GPAA1 facilitates the expression of cancer-related GPI-anchored proteins and supplies a more robust platform-the lipid raft-to promote EGFR-ERBB2 dimerization, which further contributes to tumour growth and metastasis and to cancer progression. GPAA1 could be a promising diagnostic biomarker and therapeutic target for gastric cancer.