Secretory Stanniocalcin 1 promotes metastasis of hepatocellular carcinoma through activation of JNK signaling pathway

STC1 competitively binding βPIX enhances melanoma progression via YAP nuclear translocation and M2 macrophage recruitment through the YAP/CCL2/VEGFA/AKT feedback loop

This study investigates the role of Stanniocalcin-1 (STC1) in melanoma progression, with a focus on its impact on metastasis, angiogenesis, and immune evasion. Systematic bioinformatics analysis revealed the potential influence of STC1 dysregulation on prognosis, immune cell infiltration, response to immune therapy, and cellular functions. In vitro assays were conducted to assess the proliferation, invasion, migration, and angiogenesis capabilities of A375 cells. In vivo experiments utilizing C57BL/6 J mice established a lung metastasis model using B16-F10 cells to evaluate macrophage infiltration and M2 polarization. A Transwell co-culture system was employed to explore the crosstalk between melanoma and macrophages. Molecular interactions among STC1, YAP, βPIX, and CCL2 are investigated using mass spectrometry, Co-Immunoprecipitation, Dual-Luciferase Reporter Assay, and Chromatin Immunoprecipitation experiments. STC1 was found to enhance lung metastasis by promoting the recruitment and polarization of M2 macrophages, thereby fostering an immunosuppressive microenvironment. Mechanistically, STC1 competes with YAP for binding to βPIX within the KER domain in melanoma cells, leading to YAP activation and subsequent CCL2 upregulation. CCL2-induced M2 macrophages secrete VEGFA, which enhances tumor vascularization and increases STC1 expression via the AKT signaling pathway in melanoma cells, establishing a pro-metastatic feedback loop. Notably, STC1-induced YAP activation increases PD-L1 expression, promoting immune evasion. Silencing STC1 enhances the efficacy of PD-1 immune checkpoint therapy in mice. This research elucidates STC1's role in melanoma metastasis and its complex interactions with tumor-associated macrophages, proposing STC1 as a potential therapeutic target for countering melanoma metastasis and augmenting the efficacy of PD-1 immunotherapy.

Integrins as the pivotal regulators of cisplatin response in tumor cells

Cisplatin (CDDP) is a widely used first-line chemotherapeutic drug in various cancers. However, CDDP resistance is frequently observed in cancer patients. Therefore, it is required to evaluate the molecular mechanisms associated with CDDP resistance to improve prognosis among cancer patients. Integrins are critical factors involved in tumor metastasis that regulate cell-matrix and cell-cell interactions. They modulate several cellular mechanisms including proliferation, invasion, angiogenesis, polarity, and chemo resistance. Modification of integrin expression levels can be associated with both tumor progression and inhibition. Integrins are also involved in drug resistance of various solid tumors through modulation of the tumor cell interactions with interstitial matrix and extracellular matrix (ECM). Therefore, in the present review we discussed the role of integrin protein family in regulation of CDDP response in tumor cells. It has been reported that integrins mainly promoted the CDDP resistance through interaction with PI3K/AKT, MAPK, and WNT signaling pathways. They also regulated the CDDP mediated apoptosis in tumor cells. This review paves the way to suggest the integrins as the reliable therapeutic targets to improve CDDP response in tumor cells.

Crosstalk between glioblastoma and tumor microenvironment drives proneural-mesenchymal transition through ligand-receptor interactions

Glioblastoma (GBM) is the most common intrinsic and aggressive primary brain tumor in adults, with a median survival of approximately 15 months. GBM heterogeneity is considered responsible for the treatment resistance and unfavorable prognosis. Proneural-mesenchymal transition (PMT) represents GBM malignant progression and recurrence, which might be a breakthrough to understand GBM heterogeneity and overcome treatment resistance. PMT is a complicated process influenced by crosstalk between GBM and tumor microenvironment, depending on intricate ligand-receptor interactions. In this review, we summarize the autocrine and paracrine pathways in the GBM microenvironment and related ligand-receptor interactions inducing PMT. We also discuss the current therapies targeting the PMT-related autocrine and paracrine pathways. Together, this review offers a comprehensive understanding of the failure of GBM-targeted therapy and ideas for future tendencies of GBM treatment.

Identification of MDK as a Hypoxia- and Epithelial-Mesenchymal Transition-Related Gene Biomarker of Glioblastoma Based on a Novel Risk Model and In Vitro Experiments

BACKGROUND

Tumor cells are commonly exposed to a hypoxic environment, which can easily induce the epithelial-mesenchymal transition (EMT) of tumor cells, further affecting tumor proliferation, invasion, metastasis, and drug resistance. However, the predictive role of hypoxia and EMT-related genes in glioblastoma (GBM) has not been investigated.

METHODS

Intersection genes were identified by weighted correlation network analysis (WGCNA) and differential expression analyses, and a risk model was further constructed by LASSO and Cox analyses. Clinical, immune infiltration, tumor mutation, drug treatment, and enrichment profiles were analyzed based on the risk model. The expression level of the MDK gene was tested using RT-PCR, immunohistochemistry, and immunofluorescence. CCK8 and EdU were employed to determine the GBM cells' capacity for proliferation while the migration and invasion ability were detected by a wound healing assay and transwell assay, respectively.

RESULTS

Based on the GBM data of the TCGA and GTEx databases, 58 intersection genes were identified, and a risk model was constructed. The model was verified in the CGGA cohort, and its accuracy was confirmed by the ROC curve (AUC = 0.807). After combining clinical subgroups, univariate and multivariate Cox regression analyses showed that risk score and age were independent risk factors for GBM patients. Furthermore, our subsequent analysis of immune infiltration, tumor mutation, and drug treatment showed that risk score and high- and low-risk groups were associated with multiple immune cells, mutated genes, and drugs. Enrichment analysis indicated that the differences between high- and low-risk groups were manifested in tumor-related pathways, including the PI3K-AKT and JAK-STAT pathways. Finally, in vivo experiments proved that the hypoxia environment promoted the expression of MDK, and MDK knockdown reduced the proliferation, migration, and EMT of GBM cells induced by hypoxia.

CONCLUSIONS

Our novel prognostic correlation model provided more potential treatment strategies for GBM patients.

ME2 Promotes Hepatocellular Carcinoma Cell Migration through Pyruvate

Cancer metastasis is still a major challenge in clinical cancer treatment. The migration and invasion of cancer cells into surrounding tissues and blood vessels is the primary step in cancer metastasis. However, the underlying mechanism of regulating cell migration and invasion are not fully understood. Here, we show the role of malic enzyme 2 (ME2) in promoting human liver cancer cell lines SK-Hep1 and Huh7 cells migration and invasion. Depletion of ME2 reduces cell migration and invasion, whereas overexpression of ME2 increases cell migration and invasion. Mechanistically, ME2 promotes the production of pyruvate, which directly binds to β-catenin and increases β-catenin protein levels. Notably, pyruvate treatment restores cell migration and invasion of ME2-depleted cells. Our findings provide a mechanistic understanding of the link between ME2 and cell migration and invasion.

Mesenchymal stem cell suppresses the efficacy of CAR-T toward killing lymphoma cells by modulating the microenvironment through stanniocalcin-1

Stem cells play critical roles both in the development of cancer and therapy resistance. Although mesenchymal stem cells (MSCs) can actively migrate to tumor sites, their impact on chimeric antigen receptor modified T cell (CAR-T) immunotherapy has been little addressed. Using an in vitro cell co-culture model including lymphoma cells and macrophages, here we report that CAR-T cell-mediated cytotoxicity was significantly inhibited in the presence of MSCs. MSCs caused an increase of CD4⁺ T cells and Treg cells but a decrease of CD8⁺ T cells. In addition, MSCs stimulated the expression of indoleamine 2,3-dioxygenase and programmed cell death-ligand 1 which contributes to the immune-suppressive function of tumors. Moreover, MSCs suppressed key components of the NLRP3 inflammasome by modulating mitochondrial reactive oxygen species release. Interestingly, all these suppressive events hindering CAR-T efficacy could be abrogated if the stanniocalcin-1 (STC1) gene, which encodes the glycoprotein hormone STC-1, was knockdown in MSC. Using xenograft mice, we confirmed that CAR-T function could also be inhibited by MSC in vivo, and STC1 played a critical role. These data revealed a novel function of MSC and STC-1 in suppressing CAR-T efficacy, which should be considered in cancer therapy and may also have potential applications in controlling the toxicity arising from the excessive immune response.

HIF-1α-regulated stanniocalcin-1 mediates gemcitabine resistance in pancreatic ductal adenocarcinoma via PI3K/AKT signaling pathway

Pancreatic ductal adenocarcinoma (PDAC) has a poor response to the first-line chemotherapy drug gemcitabine. We previously identified stanniocalcin-1 as a gemcitabine-resistant-related gene, but its specific role and function in pancreatic cancer remain unclear. RT-qPCR and Western blot were used to evaluate differential protein and mRNA expressions. The biological functions of genes were determined using proliferation and drug-resistance experiments. Subcutaneous tumorigenesis experiment was performed on nude mice. Prognostic analysis was performed using public databases and our clinical data. We found HIF-1α-regulated STC1 expression mediated chemoresistance in pancreatic cancer. Deeper, we explored the action mechanism of STC1 and identified PI3K/AKT as the downstream signaling pathway of STC1. Furthermore, we analyzed clinical data and found that STC1 expression was related to the prognosis of gemcitabine-treated patients after surgery. In general, we proved the HIF-1α/STC1/PI3K-AKT axis participated in PDAC progression and chemoresistance, and STC1 may serve as a potential prognostic factor and therapeutic target for PDAC treatment.

Stanniocalcin 1 promotes metastasis, lipid metabolism and cisplatin chemoresistance via the FOXC2/ITGB6 signaling axis in ovarian cancer

BACKGROUND

Stanniocalcin 1 (STC1) plays an integral role in ovarian cancer (OC). However, the functional role of STC1 in metastasis, lipid metabolism and cisplatin (DDP) chemoresistance in OC is not fully understood.

METHODS

Single-cell sequencing and IHC analysis were performed to reveal STC1 expression profiles in patient tissues. Metastasis, lipid metabolism and DDP chemoresistance were subsequently assessed. Cell-based in vitro and in vivo assays were subsequently conducted to gain insight into the underlying mechanism of STC1 in OC.

RESULTS

Single-cell sequencing assays and IHC analysis verified that STC1 expression was significantly enhanced in OC tissues compared with para-carcinoma tissues, and it was further up-regulated in peritoneal metastasis tissues compared with OC tissues. In vitro and in vivo experiments demonstrated that STC1 promoted metastasis, lipid metabolism and DDP chemoresistance in OC. Simultaneously, STC1 promoted lipid metabolism by up-regulating lipid-related genes such as UCP1, TOM20 and perilipin1. Mechanistically, STC1 directly bound to integrin β6 (ITGB6) to activate the PI3K signaling pathway. Moreover, STC1 was directly regulated by Forkhead box C2 (FOXC2) in OC. Notably, targeting STC1 and the FOXC2/ITGB6 signaling axis was related to DDP chemoresistance in vitro.

CONCLUSIONS

Overall, these findings revealed that STC1 promoted metastasis, lipid metabolism and DDP chemoresistance via the FOXC2/ITGB6 signaling axis in OC. Thus, STC1 may be used as a prognostic indicator in patients with metastatic OC. Meanwhile, STC1 could be a therapeutic target in OC patients, especially those who have developed chemoresistance to DDP.

Serum Autoantibodies against LRDD, STC1, and FOXA1 as Biomarkers in the Detection of Ovarian Cancer

Purpose

This study is aimed at evaluating serum autoantibodies against four tumor-associated antigens, including LRDD, STC1, FOXA1, and EDNRB, as biomarkers in the immunodiagnosis of ovarian cancer (OC).

Methods

The autoantibodies against LRDD, STC1, FOXA1, and EDNRB were measured using an enzyme-linked immunosorbent assay (ELISA) in 94 OC patients and 94 normal healthy controls (NHC) in the research group. In addition, the diagnostic values of different autoantibodies were validated in another independent validation group, which comprised 136 OC patients, 136 NHC, and 181 patients with benign ovarian diseases (BOD).

Results

In the research group, autoantibodies against LRDD, STC1, and FOXA1 had higher serum titer in OC patients than NHC (P < 0.001). The area under receiver operating characteristic curves (AUCs) of these three autoantibodies were 0.910, 0.879, and 0.817, respectively. In the validation group, they showed AUCs of 0.759, 0.762, and 0.817 and sensitivities of 49.3%, 42.7%, and 48.5%, respectively, at specificity over 90% for discriminating OC patients from NHC. For discriminating OC patients from BOD, they showed AUCs of 0.718, 0.729, and 0.814 and sensitivities of 47.1%, 39.0%, and 51.5%, respectively, at specificity over 90%. The parallel analyses demonstrated that the combination of anti-LRDD and anti-FOXA1 autoantibodies achieved the optimal diagnostic performance with the sensitivity of 58.1% at 87.5% specificity and accuracy of 72.8%. The positive rate of the optimal autoantibody panel improved from 62.4% to 87.1% when combined with CA125 in detecting OC patients.

Conclusion

Serum autoantibodies against LRDD, STC1, and FOXA1 have potential diagnostic values in detecting OC.

Prognostic value of STC1 in solid tumors: a meta-analysis

Aim: The prognostic value of STC1 has been evaluated in solid tumors. However, the results remain controversial. Materials & methods: Relevant studies published up to 27 February 2021 were identified by a comprehensive search of the PubMed, EMBASE and Web of Science databases. Hazard ratios (HRs) and odds ratios with 95% CIs were applied to explore the association between STC1 and survival outcome and clinical characteristics. Results: Sixteen articles involving 2942 participants were included in this meta-analysis. The pooled analysis showed that high STC1 expression was significantly associated with worse overall survival (HR: 1.91; 95% CI: 1.63-2.24) and disease-free survival/progression-free survival/relapse-free survival (HR: 2.01; 95% CI: 1.34-3.02). Conclusion: STC1 may be an effective prognostic marker in solid tumors.

Stanniocalcin 1 is a serum biomarker and potential therapeutic target for HBV-associated liver fibrosis

Stanniocalcin 1 (STC1), a secreted protein, is upregulated in human cancers including hepatocellular carcinoma (HCC). While most HCCs develop from chronic liver disease which involves progressive parenchymal injury and fibrosis, the role of STC1 in this pre-neoplastic stage remains poorly understood. In this study, we investigated the clinical relevance and functional significance of secreted STC1 in liver fibrosis. To this end, STC1 level was determined in the serum samples of chronic hepatitis B patients and correlated with the degree of liver fibrosis. Diagnostic performance of STC1 was analysed by area under receiver operating characteristic curve (AUROC), sensitivity, specificity, positive predictive value, and negative predictive value. The results were compared with other well-characterised serum biomarkers for liver fibrosis, aspartate transaminase to Platelet Ratio Index (APRI) and Fibrosis-4 (FIB-4). The functional role of STC1 was interrogated by in vitro experiments using cell line models. Expression of fibrogenic markers was quantified by RT-qPCR and western blotting. Our results showed that serum STC1 level in chronic hepatitis B patients was positively correlated with the degree of liver fibrosis and showed a stepwise increase in accordance with the severity of fibrosis. The AUROCs for detecting significant fibrosis (>9.0 kPa) and cirrhosis (>12.0 kPa) was 0.911 and 0.880, respectively. STC1 demonstrated a superior specificity and positive predictive value when compared to APRI and FIB-4. Consistent with this, STC1 was elevated in the liver tissues and sera of CCl₄ -treated mice showing marked liver fibrosis. In vitro, STC1 was secreted by the human hepatic stellate cell line LX2. Human recombinant STC1 (rhSTC1) induced expression of fibrogenic markers in LX2 cells. The pro-fibrogenic phenotype conferred by rhSTC1 or TGF-β1 in LX2 cells could be attenuated using anti-STC1 antibody. Taken together, STC1 is a specific serum biomarker for HBV-associated liver fibrosis. STC1 functionally promotes liver fibrogenesis and is a potential actionable target. This article is protected by copyright. All rights reserved.

STC1 is a Novel Biomarker Associated with Immune Characteristics and Prognosis of Bladder Cancer

Background

Stanniocalcin-1 (STC1) is a well-studied oncogene that promotes different types of cancer progression. However, the expression status of STC1, the values of STC1 on prognosis, and its immune characteristic in bladder cancer (BLCA) have not been well examined.

Methods

The expression of STC1 and its clinicopathological as well as immune characteristics in BLCA samples were firstly identified in The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Immunohistochemistry (IHC) performed on the tissue microarray (TMA) slide was further used to validate the expression of STC1 and its relationship with immune features in 16 non-muscle invasive bladder cancer (NMIBC) samples and 42 muscle invasive bladder cancer (MIBC) samples.

Results

The expression of STC1 was upregulated in higher stage BLCA. High STC1 expression also predicted poor prognosis in BLCA. Subsequently, the TMA validated the expression and prognostic value of STC1 in BLCA. Bioinformatics analysis demonstrated that STC1 and common immune checkpoints as well as immune markers of various immune cells were positively correlated in TCGA. In addition, IHC data from the TMA further validated that tumor cells with higher STC1 level tended to express higher PDL1 as well as increased infiltration of CD3+ T cells.

Conclusion

To our knowledge, this is the first comprehensive study that investigates the clinical and immune characteristics of STC1 in BLCA. It may provide new insight into the function of STC1 in regulating tumor immune microenvironment. Further studies are warranted to uncover the potential mechanisms that mediate STC1 expression and tumor immunity in BLCA.

Development and Validation of a Hypoxia-Related Signature for Predicting Survival Outcomes in Patients With Bladder Cancer

Objectives

This study aimed to develop and validate a hypoxia signature for predicting survival outcomes in patients with bladder cancer.

Methods

We downloaded the RNA sequence and the clinicopathologic data of the patients with bladder cancer from The Cancer Genome Atlas (TCGA) (https://portal.gdc.cancer.gov/repository?facetTab=files) and the Gene Expression Omnibus (GEO) (https://www.ncbi.nlm.nih.gov/geo/) databases. Hypoxia genes were retrieved from the Molecular Signatures Database (https://www.gsea-msigdb.org/gsea/msigdb/index.jsp). Differentially expressed hypoxia-related genes were screened by univariate Cox regression analysis and Lasso regression analysis. Then, the selected genes constituted the hypoxia signature and were included in multivariate Cox regression to generate the risk scores. After that, we evaluate the predictive performance of this signature by multiple receiver operating characteristic (ROC) curves. The CIBERSORT tool was applied to investigate the relationship between the hypoxia signature and the immune cell infiltration, and the maftool was used to summarize and analyze the mutational data. Gene-set enrichment analysis (GSEA) was used to investigate the related signaling pathways of differentially expressed genes in both risk groups. Furthermore, we developed a model and presented it with a nomogram to predict survival outcomes in patients with bladder cancer.

Results

Eight genes (AKAP12, ALDOB, CASP6, DTNA, HS3ST1, JUN, KDELR3, and STC1) were included in the hypoxia signature. The patients with higher risk scores showed worse overall survival time than the ones with lower risk scores in the training set (TCGA) and two external validation sets (GSE13507 and GSE32548). Immune infiltration analysis showed that two types of immune cells (M0 and M1 macrophages) had a significant infiltration in the high-risk group. Tumor mutation burden (TMB) analysis showed that the risk scores between the wild types and the mutation types of TP53, MUC16, RB1, and FGFR3 were significantly different. Gene-Set Enrichment Analysis (GSEA) showed that immune or cancer-associated pathways belonged to the high-risk groups and metabolism-related signal pathways were enriched into the low-risk group. Finally, we constructed a predictive model with risk score, age, and stage and validated its performance in GEO datasets.

Conclusion

We successfully constructed and validated a novel hypoxia signature in bladder cancer, which could accurately predict patients’ prognosis.

Melatonin Induces Apoptosis and Modulates Cyclin Expression and MAPK Phosphorylation in Pancreatic Stellate Cells Subjected to Hypoxia

In certain diseases of the pancreas, pancreatic stellate cells form an important part of fibrosis and are critical for the development of cancer cells. A hypoxic condition develops within the tumor, to which pancreatic stellate cells adapt and are able to proliferate. The consequence is the growth of the tumor. Melatonin, the product of the pineal gland, is gaining attention as an agent with therapeutic potential against pancreatic cancers. Its actions on tumor cells lead, in general, to a reduction in cell viability and proliferation. However, its effects on pancreatic stellate cells subjected to hypoxia are less known. In this study, we evaluated the actions of pharmacological concentrations of melatonin (1 mM–1 µM) on pancreatic stellate cells subjected to hypoxia. The results show that melatonin induced a decrease in cell viability at the highest concentrations tested. Similarly, the incorporation of BrdU into DNA was diminished by melatonin. The expression of cyclins A and D also was decreased in the presence of melatonin. Upon treatment of cells with melatonin, increases in the expression of major markers of ER stress, namely BIP, phospho-eIF2α and ATF-4, were detected. Modulation of apoptosis was noticed as an increase in caspase-3 activation. In addition, changes in the phosphorylated state of p44/42, p38 and JNK MAPKs were detected in cells treated with melatonin. A slight decrease in the content of α-smooth muscle actin was detected in cells treated with melatonin. Finally, treatment of cells with melatonin decreased the expression of matrix metalloproteinases 2, 3, 9 and 13. Our observations suggest that melatonin, at pharmacological concentrations, diminishes the proliferation of pancreatic stellate cells subjected to hypoxia through modulation of cell cycle, apoptosis and the activation of crucial MAPKs. Cellular responses might involve certain ER stress regulator proteins. In view of the results, melatonin could be taken into consideration as a potential therapeutic agent for pancreatic fibrosis.

Stanniocalcin 1 is a phagocytosis checkpoint driving tumor immune resistance

Immunotherapy induces durable clinical responses in a fraction of patients with cancer. However, therapeutic resistance poses a major challenge to current immunotherapies. Here, we identify that expression of tumor stanniocalcin 1 (STC1) correlates with immunotherapy efficacy and is negatively associated with patient survival across diverse cancer types. Gain- and loss-of-function experiments demonstrate that tumor STC1 supports tumor progression and enables tumor resistance to checkpoint blockade in murine tumor models. Mechanistically, tumor STC1 interacts with calreticulin (CRT), an "eat-me" signal, and minimizes CRT membrane exposure, thereby abrogating membrane CRT-directed phagocytosis by antigen-presenting cells (APCs), including macrophages and dendritic cells. Consequently, this impairs APC capacity of antigen presentation and T cell activation. Thus, tumor STC1 inhibits APC phagocytosis and contributes to tumor immune evasion and immunotherapy resistance. We suggest that STC1 is a previously unappreciated phagocytosis checkpoint and targeting STC1 and its interaction with CRT may sensitize to cancer immunotherapy.

Modeling preeclampsia using human induced pluripotent stem cells

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder, affecting up to 10% of pregnancies worldwide. The primary etiology is considered to be abnormal development and function of placental cells called trophoblasts. We previously developed a two-step protocol for differentiation of human pluripotent stem cells, first into cytotrophoblast (CTB) progenitor-like cells, and then into both syncytiotrophoblast (STB)- and extravillous trophoblast (EVT)-like cells, and showed that it can model both normal and abnormal trophoblast differentiation. We have now applied this protocol to induced pluripotent stem cells (iPSC) derived from placentas of pregnancies with or without PE. While there were no differences in CTB induction or EVT formation, PE-iPSC-derived trophoblast showed a defect in syncytialization, as well as a blunted response to hypoxia. RNAseq analysis showed defects in STB formation and response to hypoxia; however, DNA methylation changes were minimal, corresponding only to changes in response to hypoxia. Overall, PE-iPSC recapitulated multiple defects associated with placental dysfunction, including a lack of response to decreased oxygen tension. This emphasizes the importance of the maternal microenvironment in normal placentation, and highlights potential pathways that can be targeted for diagnosis or therapy, while absence of marked DNA methylation changes suggests that other regulatory mechanisms mediate these alterations.

Prognostic and predictive impact of stroma cells defined by PDGFRb expression in early breast cancer: results from the randomized SweBCG91RT trial

Purpose

Predictive biomarkers are needed to aid the individualization of radiotherapy (RT) in breast cancer. Cancer-associated fibroblasts have been implicated in tumor radioresistance and can be identified by platelet-derived growth factor receptor-beta (PDGFRb). This study aims to analyze how PDGFRb expression affects RT benefit in a large randomized RT trial.

Methods

PDGFRb was assessed by immunohistochemistry on tissue microarrays from 989 tumors of the SweBCG91RT trial, which enrolled lymph node-negative, stage I/IIA breast cancer patients randomized to RT after breast-conserving surgery. Outcomes were analyzed at 10 years for ipsilateral breast tumor recurrence (IBTR) and any recurrence and 15 years for breast cancer specific death (BCSD).

Results

PDGFRb expression correlated with estrogen receptor negativity and younger age. An increased risk for any recurrence was noted in univariable analysis for the medium (HR 1.58, CI 95% 1.11–2.23, p = 0.011) or PDGFRb high group (1.49, 1.06–2.10, p = 0.021) compared to the low group. No differences in IBTR or BCSD risk were detected. RT benefit regarding IBTR risk was significant in the PDGFRb low (0.29, 0.12–0.67, p = 0.004) and medium (0.31, 0.16–0.59, p < 0.001) groups but not the PDGFRb high group (0.64, 0.36–1.11, p = 0.110) in multivariable analysis. Likewise, risk reduction for any recurrence was less pronounced in the PDGFRb high group. No significant interaction between RT and PDGFRb-score could be detected.

Conclusion

A higher PDGFRb-score conferred an increased risk of any recurrence, which partly can be explained by its association with estrogen receptor negativity and young age. Reduced RT benefit was noted among patients with high PDGFRb, however without significant interaction.

Research advances of secretory proteins in malignant tumors

Secretory proteins in tumor tissues are important components of the tumor microenvironment. Secretory proteins act on tumor cells or stromal cells or mediate interactions between tumor cells and stromal cells, thereby affecting tumor progression and clinical treatment efficacy. In this paper, recent research advances in secretory proteins in malignant tumors are reviewed.

Integrated miRNA and mRNA omics reveal the anti-cancerous mechanism of Licochalcone B on Human Hepatoma Cell HepG2

To unravel the potential of Licochalcone B as an anti-tumour phytochemical agent and evaluate its underlying mechanisms, we analyzed the mRNAs and miRNAs expression profiles of HepG2 cells in response to Licochalcone B (120 μM). mRNA and miRNA expression libraries were conducted and functional analysis for differential expression mRNAs was carried out utilizing Clue GO. We found 763 Licochalcone B -responsive differently expressed genes, among them, 572 mRNAs were up-regulated and 191 mRNAs were down-regulated, many of which were related to the MAPK signaling pathway. A protein-protein interaction network was constructed to discover the hub genes, and IL6, FOS, JUN, NOTCH1, UBC, UBB, CXCL8, CDKN1A, IL1B, ATF3, and GATA3 genes were screened out. Additionally, miRNAs engaged in Licochalcone B -mediated regulation on HepG2 cells were also studied. 85 differential expression miRNAs were identified, including 39 up-regulated miRNAs and 46 down-regulated miRNAs. Co-expression of miRNA-mRNA network was created and two key miRNAs (hsa-miR-29b-3p and hsa-miR-96-5p) were identified. These recognized key genes, miRNA, and the miRNA-mRNA regulatory network may provide clues to understand the molecular mechanism of Licochalcone B as an apoptotic inducer which may offer hint for its application as a functional food component.

Targeting POLE2 Creates a Novel Vulnerability in Renal Cell Carcinoma via Modulating Stanniocalcin 1

Objective

The aim of this study is to investigate the biological functions and the underlying mechanisms of DNA polymerase epsilon subunit 2 (POLE2) in renal cell carcinoma (RCC).

Methods

The datasets of POLE2 expression in The Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) and International Cancer Genome Consortium (ICGC) databases was selected and the correlation between POLE2 and various clinicopathological parameters was analyzed. The POLE2 expression in RCC tissues was examined by immunohistochemistry. The POLE2 knockdown cell lines were constructed. In vitro and in vivo experiments were carried out to investigate the function of POLE2 on cellular biology of RCC, including cell viability assay, clone formation assay, flow cytometry, wound-healing assay, Transwell assay, qRT-PCR, Western blot, etc. Besides, microarray, co-immunoprecipitation, rescue experiment, and Western blot were used to investigate the molecular mechanisms underlying the functions of POLE2.

Results

POLE2 was overexpressed in RCC tissues, and high expression of POLE2 was correlated with poor prognosis of RCC. Furthermore, knockdown of POLE2 significantly inhibited cell proliferation, migration, and facilitated apoptosis in vitro. In vivo experiments revealed that POLE2 attenuated RCC tumorigenesis and tumor growth. we also illuminated that stanniocalcin 1 (STC1) was a downstream gene of POLE2, which promoted the occurrence and development of RCC. Besides, knockdown of POLE2 significantly upregulated the expression levels of Bad and p21 while the expression levels of HSP70, IGF-I, IGF-II, survivin, and sTNF-R1 were significantly downregulated. Western blot analysis also showed that knockdown of POLE2 inhibited the expression levels of Cancer-related pathway proteins including p-Akt, CCND1, MAPK9, and PIK3CA.

Conclusion

Knockdown of POLE2 attenuates RCC cells proliferation and migration by regulating STC1, suggesting that POLE2-STC1 may become a potential target for RCC therapy.

Characterization of stanniocalcin-1 expression in macrophage differentiation

Human stanniocalcin-1 (STC1) is a paracrine factor associated with inflammation and carcinogenesis. The role of STC1 in the pro- and anti-inflammatory functions of differentiating macrophage, however, is not clear. In this study, our data showed that phorbol 12-myristate 13-acetate (PMA) treatment induced human leukemia monocytic cells (ThP-1) differentiation to M0 macrophages. The differentiation was accompanied by a significant increase in the mRNA expression levels of STC1, the pro-inflammatory cytokine TNFα, and anti-inflammatory markers, CD163 & CD206. An intermitted removal of PMA treatment reduced the mRNA levels of STC1 and TNFα but had no noticeable effects on the anti-inflammatory markers. The correlation in the expression of STC1 and pro-inflammatory markers in differentiating macrophages was investigated, using siRNA_STC1-transfected PMA-induced cells. Consistently, the transcripts levels of TNFα and IL-6 were significantly reduced. Moreover, LPS/IFNγ-induced M1-polarization showed remarkably higher expression levels of STC1 than IL-4/IL-13-induced M2-macrophages and PMA-induced M0-macrophages. Transcriptomic analysis of siRNA_STC1-transfected M1-polarized cells revealed an upregulation of TBC1 domain family member 3 (TBC1D3G). The gene regulates the payload of macrophage-released extracellular vesicles to mediate inflammation. The conditioned media from siRNA_STC1-transfected M1-polarized cells were found to reduce Hep3B cell motility. The data suggest that the expression of STC1 were associated with macrophage differentiation, but preferentially to M1 polarization.

Microenvironmental Hypoxia Induces Dynamic Changes in Lung Cancer Synthesis and Secretion of Extracellular Vesicles

Extracellular vesicles (EVs) mediate critical intercellular communication within healthy tissues, but are also exploited by tumour cells to promote angiogenesis, metastasis, and host immunosuppression under hypoxic stress. We hypothesize that hypoxic tumours synthesize hypoxia-sensitive proteins for packing into EVs to modulate their microenvironment for cancer progression. In the current report, we employed a heavy isotope pulse/trace quantitative proteomic approach to study hypoxia sensitive proteins in tumour-derived EVs protein. The results revealed that hypoxia stimulated cells to synthesize EVs proteins involved in enhancing tumour cell proliferation (NRSN2, WISP2, SPRX1, LCK), metastasis (GOLM1, STC1, MGAT5B), stemness (STC1, TMEM59), angiogenesis (ANGPTL4), and suppressing host immunity (CD70). In addition, functional clustering analyses revealed that tumour hypoxia was strongly associated with rapid synthesis and EV loading of lysosome-related hydrolases and membrane-trafficking proteins to enhance EVs secretion. Moreover, lung cancer-derived EVs were also enriched in signalling molecules capable of inducing epithelial-mesenchymal transition in recipient cancer cells to promote their migration and invasion. Together, these data indicate that lung-cancer-derived EVs can act as paracrine/autocrine mediators of tumorigenesis and metastasis in hypoxic microenvironments. Tumour EVs may, therefore, offer novel opportunities for useful biomarkers discovery and therapeutic targeting of different cancer types and at different stages according to microenvironmental conditions.

MicroRNA-34c Inhibits Osteogenic Differentiation and Valvular Interstitial Cell Calcification via STC1-Mediated JNK Pathway in Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD), a common heart valve disease, is increasingly prevalent worldwide and causes high morbidity and mortality. Here, we aimed to investigate a possible role for miR-34c in the development of osteogenic differentiation during CAVD and to find out the underlying mechanisms. Valvular interstitial cells (VICs) were isolated from the clinical aortic valve tissue samples of CAVD patients and patients with acute aortic dissection and collected. Then, RT-qPCR was performed to determine miR-34c expression and western blot analysis was applied to confirm the relevant protein expression in these VICs. Dual luciferase reporter gene assay was applied to confirm the relation between miR-34c and STC1. Alkaline phosphatase (ALP) staining and alizarin red staining was performed to further confirm the degree of calcification in these samples. MiR-34c was lowly expressed and STC1 was highly expressed in the CAVD tissues. Furthermore, STC1 was the target of miR-34c and was negatively regulated by miR-34c. Overexpression of miR-34c in VICs was concomitant with suppression of both STC1 expression and phosphorylation level of c-Jun N-terminal kinase (JNK). In addition, significant decrease of bone morphogenetic protein-2 (BMP2) and osteocalcin, as well as the decrease of calcification degree were also observed in VICs with miR-34c overexpressed. Taken together, miR-34c could inhibit osteogenic differentiation and calcification of VICs by suppressing the STC1/JNK signaling pathway in CAVD, making miR-34c a novel therapeutic target for the treatment of CAVD.

Pancreatic stellate cells exhibit adaptation to oxidative stress evoked by hypoxia

BACKGROUND INFORMATION

Pancreatic stellate cells play a key role in the fibrosis that develops in diseases such as pancreatic cancer. In the growing tumour, a hypoxia condition develops under which cancer cells are able to proliferate. The growth of fibrotic tissue contributes to hypoxia. In this study, the effect of hypoxia (1% O₂ ) on pancreatic stellate cells physiology was investigated. Changes in intracellular free-Ca²⁺ concentration, mitochondrial free-Ca²⁺ concentration and mitochondrial membrane potential were studied by fluorescence techniques. The status of enzymes responsible for the cellular oxidative state was analyzed by quantitative reverse transcription-polymerase chain reaction, high-performance liquid chromatography, spectrophotometric and fluorimetric methods and by Western blotting analysis. Cell viability and proliferation were studied by crystal violet test, 5-bromo-2-deoxyuridine cell proliferation test and Western blotting analysis. Finally, cell migration was studied employing the wound healing assay.

RESULTS

Hypoxia induced an increase in intracellular and mitochondrial free-Ca²⁺ concentration, whereas mitochondrial membrane potential was decreased. An increase in mitochondrial reactive oxygen species production was observed. Additionally, an increase in the oxidation of proteins and lipids was detected. Moreover, cellular total antioxidant capacity was decreased. Increases in the expression of superoxide dismutase 1 and 2 were observed and superoxide dismutase activity was augmented. Hypoxia evoked a decrease in the oxidized/reduced glutathione ratio. An increase in the phosphorylation of nuclear factor erythroid 2-related factor and in expression of the antioxidant enzymes catalytic subunit of glutamate-cysteine ligase, catalase, NAD(P)H-quinone oxidoreductase 1 and heme oxygenase-1 were detected. The expression of cyclin A was decreased, whereas expression of cyclin D and the content of 5-bromo-2-deoxyuridine were increased. This was accompanied by an increase in cell viability. The phosphorylation state of c-Jun NH₂ -terminal kinase was increased, whereas that of p44/42 and p38 was decreased. Finally, cells subjected to hypoxia maintained migration ability.

CONCLUSIONS AND SIGNIFICANCE

Hypoxia creates pro-oxidant conditions in pancreatic stellate cells to which cells adapt and leads to increased viability and proliferation.

Oleanolic acid alleviates oxidative stress in Alzheimer's disease by regulating stanniocalcin-1 and uncoupling protein-2 signalling

Oxidative stress is thought to play an important role in the occurrence and development of Alzheimer's disease (AD) and antioxidants may delay or even treat AD. Oleanolic acid (OA) exhibits antioxidant properties against many diseases. However, its effects on oxidative stress in AD remain unclear. Here, we explored the role and mechanism of action of OA in N2a/APP695swe cells exposed to oxidative stress. The cells were incubated with different concentrations of OA (0, 5, 8, 10, 15, and 25 μmol/L) for 24 hours. Higher concentrations of OA (10, 15, and 25 μmol/L) significantly suppressed the apoptosis, caspase-3 activity, reactive oxygen species level, and β amyloid (Aβ) content and increased the viability of these cells. OA (10 μmol/L) also increased the expression of stanniocalcin-1 (STC-1) and uncoupling protein-2 (UCP2) in N2a/APP695swe cells. STC-1 interference markedly reversed the effect of OA on UCP2, indicating that OA may regulate UCP2 expression in N2a/APP695swe cells via STC-1. Moreover, UCP2 inhibition significantly reversed the OA-mediated effects on cell viability, caspase-3 activity, reactive oxygen species, and Aβ level. Thus, OA regulates UCP2 expression via STC-1 to alleviate oxidative stress and Aβ level in N2a/APP695swe cells.

Stanniocalcin 1 is a prognostic biomarker in glioma

Malignant gliomas are the most common type of primary malignancy of the central nervous system with a poor prognosis. Stanniocalcin 1 (STC1) is closely associated with tumor genesis and development. However, its role in the development and progression of glioma is poorly understood. In silico analysis, The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), Rembrandt and GSE16011 datasets were used to assess the expression levels of STC1 in non-tumor brain tissues and gliomas. Moreover, reverse transcription-quantitative PCR and immunohistochemistry were used to detect STC1 expression in tumor tissues collected in the Department of Neurosurgery of Shenzhen People's Hospital (Shenzhen, China). The association between STC1 expression and different molecular pathological features was analyzed in four public datasets, as well as via Kaplan-Meier analysis. Furthermore, normalized mRNA expression in TCGA was used to perform Gene Ontology analysis. It was revealed that STC1 expression was significantly elevated in glioma tissues compared with the non-tumor brain tissues, both in silico analysis and via cohort validation. According to TCGA, CGGA, Rembrandt and GSE16011 datasets, it was identified that STC1 expression was increased in high grade glioma compared with low grade glioma. In addition, the results indicated STC1 expression was enriched in the isocitrate dehydrogenase (IDH) wild-type and mesenchymal subtype in TCGA, GSE16011 and Rembrandt datasets. Moreover, it was demonstrated that patients with higher STC1 expression exhibited shorter overall survival times compared with those with lower STC1 expression using Kaplan-Meier analysis, according to both the public datasets and validation cohort. Furthermore, the results of the Gene Ontology analysis demonstrated that STC1 was primarily involved in the reorganization of extracellular matrix and was significantly correlated with invasive-related proteins. Therefore, the present results indicate that STC1 was upregulated in glioma tissues and may represent a prognostic biomarker in patients with glioma.

Expression, function and clinical application of stanniocalcin-1 in cancer

The glycoprotein stanniocalcin-1 functions as a regulatory endocrine hormone that maintains the balance of calcium and phosphorus in bony fish and as a paracrine/autocrine factor involved in many physiological/pathological processes in humans, including carcinogenesis. In this review, we provide an overview of (a) the possible mechanisms through which STC1 affects the malignant properties of cancer, (b) transcriptional and post-transcriptional regulation pathways of STC1 and (c) the potential clinical relevance of STC1 as a cancer biomarker and even a therapeutic target in the future. Exploring the role of STC1 in cancer development may provide a better understanding of the tumorigenesis process in humans and may facilitate finding an effective therapeutic method against cancer.

The stress-activated protein kinase pathway and the expression of stanniocalcin-1 are regulated by miR-146b-5p in papillary thyroid carcinogenesis

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Deciphering the pathophysiological mechanisms that contribute to PTC development is essential to the discovery of optimal diagnostic and therapeutic approaches. MiR-146b-5p has been identified as a cancer-associated microRNA highly up-regulated in PTC. This study explores the hypothesis that miR-146b-5p contributes to papillary thyroid carcinogenesis through regulation of cell signaling pathways in a manner that overcomes the cellular growth suppressive events and provides survival advantage. The effect of miR-146b-5p inhibition on major cancer related signaling pathways and expression of Stanniocalcin-1 (STC1), an emerging molecule associated with stress response and carcinogenesis, was tested in cultured primary thyroid cells using luciferase reporter assays, quantitative real-time PCR, immunofluorescence staining, and flow cytometry. Our results demonstrated that miR-146b-5p inhibits the JNK/AP1 pathway activity and down-regulates the expression of STC-1 in thyroid-cultured cells and in thyroid tissue samples. In the presence of miR-146b-5p, PTC cells were resistant to cell death in response to oxidative stress. This is a novel report that miR-146b-5p directly targets STC1 and regulates the activity of JNK/AP1 pathway. Considering the importance of the JNK/AP1 pathway and STC1 in mediating many physiological and pathological processes like apoptosis, stress response and cellular metabolism, a biological regulator of these pathways would have a great scientific and clinical significance.

MLL2 promotes cancer cell lymph node metastasis by interacting with RelA and facilitating STC1 transcription

Esophageal squamous cell carcinoma (ESCC) presents with lymph node metastasis in the early stages, limiting the opportunities for curative local resection, including endoscopic submucosal dissection (ESD). ESD is regarded as the standard treatment for early-stage ESCCs. However, radical surgery is recommended when lymph node metastasis risk exists. More efforts are needed to find the markers for early prediction and clarify the molecular mechanism underlying the pathogenesis of lymph node metastasis. Recently, aberrant regulation of gene expression by histone methylation modifiers has emerged as an important mechanism for cancer metastasis. Herein, we demonstrated that mixed-lineage leukemia 2 (MLL2) positively regulates gene expression programs associated with ESCC cell migration. MLL2 interacts with RelA in the nucleus to enhance transcription of stanniocalcin-1 (STC1) and to facilitate cancer metastasis. Meanwhile, MLL2 knockdown resulted in a significant decrease in the migration of ESCC cells. Clinically, high level of MLL2 was significantly associated with early-stage ESCC lymph node metastasis. In summary, these findings discovered a previously unidentified molecular pathway underlying the coordinated regulation of metastasis-related STC-1 expression by MLL2 and RelA and highlighted the critical role of MLL2 in ESCC.

Antagonism between the RNA-binding protein Musashi1 and miR-137 and its potential impact on neurogenesis and glioblastoma development

RNA-binding proteins (RBPs) and miRNAs are critical gene expression regulators that interact with one another in cooperative and antagonistic fashions. We identified Musashi1 (Msi1) and miR-137 as regulators of a molecular switch between self-renewal and differentiation. Msi1 and miR-137 have opposite expression patterns and functions, and Msi1 is repressed by miR-137. Msi1 is a stem-cell protein implicated in self-renewal while miR-137 functions as a proneuronal differentiation miRNA. In gliomas, miR-137 functions as a tumor suppressor while Msi1 is a prooncogenic factor. We suggest that the balance between Msi1 and miR-137 is a key determinant in cell fate decisions and disruption of this balance could contribute to neurodegenerative diseases and glioma development. Genomic analyses revealed that Msi1 and miR-137 share 141 target genes associated with differentiation, development, and morphogenesis. Initial results pointed out that these two regulators have an opposite impact on the expression of their target genes. Therefore, we propose an antagonistic model in which this network of shared targets could be either repressed by miR-137 or activated by Msi1, leading to different outcomes (self-renewal, proliferation, tumorigenesis).

LncRNA TRERNA1 facilitates hepatocellular carcinoma metastasis by dimethylating H3K9 in the CDH1 promoter region via the recruitment of the EHMT2/SNAI1 complex

Objectives

Long non‐coding RNAs (LncRNAs) play an important role in hepatocellular carcinoma development, however, as a crucial driver of hepatocellular carcinoma (HCC) metastasis, their functions in tumour metastasis remain largely unknown.

Materials and methods

The lncRNA TRERNA1 expression levels were detected in HCC by quantitative real‐time PCR (qPCR). The function of TRERNA1 was examined by wound‐healing assays, transwell assays and tail vein injection experiments. The potential regulatory mechanisms of TRERNA1 on its target genes were explored by ChIP, RIP, IP and WB assays.

Results

Elevated TRERNA1 levels promoted HCC cell migration and invasion in vitro and in vivo. TRERNA1 recruited EHMT2 to dimethylate H3K9 in the CDH1 promoter region. Furthermore, EHMT2 bound to SNAI1 to suppress CDH1 expression in HCC cells. After inhibiting TRERNA1, the expression level of CDH1 was restored and was involved in the regulation of the EHMT2/SNAI1 complex. The level of TRERNA1 was positively correlated with tumour metastasis and was negatively correlated with the expression of CDH1 in HCC tissues.

Conclusions

For the first time, the current study reveals that TRERNA1 promotes cell metastasis and the invasion of HCC via the recruitment of EHMT2 and/or the EHMT2/SNAI1 complex to suppress CDH1. These data identify a novel mechanism that regulates TRERNA1 in metastatic HCC and provides a potential targeted therapy for HCC patients.

Stanniocalcin 1 in tumor microenvironment promotes metastasis of ovarian cancer

Background: Tumor metastasis is the major challenge for ovarian cancer treatment. Cancer-associated fibroblasts (CAFs), a major component existing in tumor microenvironment, can secrete several cytokines to interact with cancer epithelial cells, and promote cancer metastasis. Stanniocalcin 1 (STC1), a secretory glycoprotein hormone, has been proven to be an important factor in ovarian tumorigenesis. Methods: In this study, we focused on the functional role of STC1 in ovarian cancer microenvironment, investigated STC1's effects on the proliferation and metastasis of ovarian cancer cells, and explored the molecular mechanism underlying STC1-mediated cancer metastasis. Results: By analyzing the GEO dataset and examined STC1 expression in CAFs isolated from ovarian cancer patients, we found that expression of STC1 was higher in ovarian cancer stroma and CAFs than in the normal ovarian stroma and normal fibroblasts (NFs). Addition of recombinant human STC1 (rhSTC1) promoted cell proliferation and metastasis in ovarian cancer, while adoption of STC1 neutralizing antibody (STC1 Ab) abolished the effects. Furthermore, our results revealed that STC1 promoted the phosphorylation of Akt (Ser473), and upregulated several epithelial-mesenchymal transition (EMT) markers including fibronectin，vimentin and slug. In addition, we demonstrated that STC1 in tumor microenvironment could mediate the conversion of NFs to CAFs. Conclusion: Taken together, the study results suggested the crucial role of STC1 in tumor environment on the metastasis of ovarian cancer.

MicroRNA regulating stanniocalcin-1 is a metastasis and dissemination promoting factor in glioblastoma

BACKGROUND

MicroRNAs (miRs) regulate many biological processes, such as invasion, angiogenesis, and metastasis. Glioblastoma (GBM) patients with metastasis/metastatic dissemination have a very poor prognosis; therefore, inhibiting metastasis/metastatic dissemination has become an important therapeutic strategy for GBM treatment.

METHODS

Using 76 GBM tissues, we examined the expression levels of 23 GBM-related miRs and compared the miRs' expression levels between GBMs with metastasis/metastatic dissemination and GBMs without metastasis/metastatic dissemination. Using the bioinformatics web site, we searched the target genes of miRs. To analyze the function of target gene, several biological assays and survival analysis by the Kaplan-Meier method were performed.

RESULTS

We found that eight miRs were significantly decreased in GBM with metastasis/metastatic dissemination. By the bioinformatics analysis, we identified stanniocalcin-1 (STC1) as the most probable target gene against the combination of these miRs. Four miRs (miR-29B, miR-34a, miR-101, and miR-137) have predictive binding sites in STC1 mRNA, and mRNA expression of STC1 was downregulated by mimics of these miRs. Also, mimics of these miRs and knockdown of STC1 by siRNA suppressed invasion in GBM cells. GBM with metastasis/metastatic dissemination had significantly higher levels of STC1 than GBM without metastasis/metastatic dissemination. Finally, Kaplan-Meier analysis demonstrated that GBMs with high STC1 level had significantly shorter survival than GBMs with low STC1 level.

CONCLUSIONS

STC1 may be a novel metastasis/metastatic dissemination promoting factor regulated by several miRs in GBM. Because STC1 is a secreted glycoprotein and functions via the autocrine/paracrine signals, inhibiting STC1 signal may become a novel therapeutic strategy for GBM.

High throughput silencing identifies novel genes in endometrioid endometrial cancer

OBJECTIVE

To validate the gene expression profile obtained from the previous microarray analysis and to further study the biological functions of these genes in endometrial cancer. From our previous study, we identified 621 differentially expressed genes in laser-captured microdissected endometrioid endometrial cancer as compared to normal endometrial cells. Among these genes, 146 were significantly up-regulated in endometrial cancer.

MATERIALS AND METHODS

A total of 20 genes were selected from the list of up-regulated genes for the validation assay. The qPCR confirmed that 19 out of the 20 genes were up-regulated in endometrial cancer compared with normal endometrium. RNA interference (RNAi) was used to knockdown the expression of the upregulated genes in ECC-1 and HEC-1A endometrial cancer cell lines and its effect on proliferation, migration and invasion were examined.

RESULTS

Knockdown of MIF, SOD2, HIF1A and SLC7A5 by RNAi significantly decreased the proliferation of ECC-1 cells (p < 0.05). Our results also showed that the knockdown of MIF, SOD2 and SLC7A5 by RNAi significantly decreased the proliferation and migration abilities of HEC-1A cells (p < 0.05). Moreover, the knockdown of SLC38A1 and HIF1A by RNAi resulted in a significant decrease in the proliferation of HEC1A cells (p < 0.05).

CONCLUSION

We have identified the biological roles of SLC38A1, MIF, SOD2, HIF1A and SLC7A5 in endometrial cancer, which opens up the possibility of using the RNAi silencing approach to design therapeutic strategies for treatment of endometrial cancer.

Loss of Linc01060 induces pancreatic cancer progression through vinculin-mediated focal adhesion turnover

There is currently limited knowledge regarding the involvement of long non-coding RNAs (lncRNAs) in cancer development. We aimed to identify lncRNAs with important roles in pancreatic cancer progression. We screened for lncRNAs that were differentially expressed in pancreatic cancer tissues. Among 349 differentially expressed lncRNAs, Linc01060 showed the lowest expression in pancreatic cancer tissues compared with normal pancreatic tissues. Lower Linc01060 expression in pancreatic cancer tissues was significantly associated with a poor prognosis. Linc01060 inhibited pancreatic cancer proliferation and invasion in vitro and in vivo. Vinculin overexpression inhibited Linc01060KD-mediated increases in FAK and paxillin phosphorylation, whereas vinculin knockdown reversed the Linc01060-mediated repression of FAK and inactivation of focal adhesion turnover. Vinculin knockdown also accelerated pancreatic cancer cell proliferation by upregulating ERK activity. In biological function analyses, vinculin overexpression abrogated Linc01060-mediated repression of pancreatic cancer cell proliferation and invasion, whereas vinculin counteracted the Linc01060-mediated repression of PC cell proliferation and invasion. These data demonstrate that Linc01060 plays a key role in suppressing pancreatic cancer progression by regulating vinculin expression. These findings suggest that the Linc01060-vinculin-focal adhesion axis is a therapeutic target for pancreatic cancer treatment.