The Lim1 oncogene as a new therapeutic target for metastatic human renal cell carcinoma

ERN1 knockdown modifies the hypoxic regulation of homeobox gene expression in U87MG glioblastoma cells

OBJECTIVE.

Homeobox genes play an important role in health and disease including oncogenesis. The present investigation aimed to study ERN1-dependent hypoxic regulation of the expression of genes encoding homeobox proteins MEIS (zinc finger E-box binding homeobox 2) and LIM homeobox 1 family, SPAG4 (sperm associated antigen 4) and NKX3-1 (NK3 homeobox 1) in U87MG glioblastoma cells in response to inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) for evaluation of their possible significance in the control of glioblastoma growth.

METHODS.

The expression level of homeobox genes was studied in control (transfected by vector) and ERN1 knockdown U87MG glioblastoma cells under hypoxia induced by dimethyloxalylglycine (0.5 mM for 4 h) by quantitative polymerase chain reaction and normalized to ACTB.

RESULTS.

It was found that hypoxia down-regulated the expression level of LHX2, LHX6, MEIS2, and NKX3-1 genes but up-regulated the expression level of MEIS1, LHX1, MEIS3, and SPAG4 genes in control glioblastoma cells. At the same time, ERN1 knockdown of glioblastoma cells significantly modified the sensitivity of all studied genes to a hypoxic condition. Thus, ERN1 knockdown of glioblastoma cells removed the effect of hypoxia on the expression of MEIS1 and LHX1 genes, but increased the sensitivity of MEIS2, LHX2, and LHX6 genes to hypoxia. However, the expression of MEIS3, NKX3-1, and SPAG4 genes had decreased sensitivity to hypoxia in ERN1 knockdown glioblastoma cells. Moreover, more pronounced changes under the conditions of ERN1 inhibition were detected for the pro-oncogenic gene SPAG4.

CONCLUSION.

The results of the present study demonstrate that hypoxia affected the expression of homeobox genes MEIS1, MEIS2, MEIS3, LHX1, LHX2, LHX6, SPAG4, and NKX3-1 in U87MG glioblastoma cells in gene-specific manner and that the sensitivity of all studied genes to hypoxia condition is mediated by ERN1, the major pathway of the endoplasmic reticulum stress signaling, and possibly contributed to the control of glioblastoma growth. A fundamentally new results of this work is the establishment of the fact regarding the dependence of hypoxic regulation of SPAG4 gene expression on ER stress, in particular ERN1, which is associated with suppression of cell proliferation and tumor growth.

ApoM suppresses kidney renal clear cell carcinoma growth and metastasis via the Hippo-YAP signaling pathway

Renal cell carcinoma is one of the most common malignancies worldwide, and kidney renal clear cell carcinoma (KIRC) is the most common histopathological type of renal cell carcinoma. However, the mechanism of KIRC progression remains poorly understood. Apolipoprotein M (ApoM) is a plasma apolipoprotein and a member of the lipid transport protein superfamily. Lipid metabolism is essential for tumor progression, and its related proteins can be used as therapeutic targets for tumors. ApoM influences the development of several cancers, but its relationship with KIRC remains unclear. In this study, we aimed to investigate the biological function of ApoM in KIRC and to reveal its potential molecular mechanisms. We found that ApoM expression was significantly reduced in KIRC and was strongly correlated with patient prognosis. ApoM overexpression significantly inhibited KIRC cell proliferation in vitro, suppressed the epithelial mesenchymal transition (EMT) of KIRC cells, and decreased their metastatic capacity. Additionally, the growth of KIRC cells was inhibited by ApoM overexpression in vivo. In addition, we found that overexpression of ApoM in KIRC attenuated Hippo-YAP protein expression and YAP stability and thus inhibited KIRC growth and progression. Therefore, ApoM may be a potential target for the treatment of KIRC.

Animal models of cancer metastasis to the bone

Cancer metastasis is a major cause of mortality from several tumors, including those of the breast, prostate, and the thyroid gland. Since bone tissue is one of the most common sites of metastasis, the treatment of bone metastases is crucial for the cure of cancer. Hence, disease models must be developed to understand the process of bone metastasis in order to devise therapies for it. Several translational models of different bone metastatic tumors have been developed, including animal models, cell line injection models, bone implant models, and patient-derived xenograft models. However, a compendium on different bone metastatic cancers is currently not available. Here, we have compiled several animal models derived from current experiments on bone metastasis, mostly involving breast and prostate cancer, to improve the development of preclinical models and promote the treatment of bone metastasis.

LIM1 contributes to the malignant potential of endometrial cancer

Introduction

The incidence of endometrial cancer (EC) has been increasing worldwide. However, because there are limited chemotherapeutic options for the treatment of EC, the prognosis of advanced-stage EC is poor.

Methods

Gene expression profile datasets for EC cases registered in The Cancer Genome Atlas (TCGA) was reanalyzed. Highly expressed genes in advanced-stage EC (110 cases) compared with early-stage EC (255 cases) were extracted and Gene Ontology (GO) enrichment analysis was performed. Among the enriched genes, Kaplan-Meier (KM) plotter analysis was performed. Candidate genes expression was analyzed in HEC50B cells and Ishikawa cells by RT-qPCR. In HEC50B cells, LIM homeobox1 (LIM1) was knocked down (KD) and cell proliferation, migration, and invasion ability of the cells were evaluated. Xenografts were generated using LIM1-KD cells and tumor growth was evaluated. Ingenuity Pathway Analysis (IPA) of RNA-seq data using LIM-KD cells was performed. Expression of phospho-CREB and CREB-related proteins were evaluated in LIM1-KD cells by western blotting and in xenograft tissue by immunofluorescent staining. Two different CREB inhibitors were treated in HEC50B and cell proliferation was evaluated by MTT assay.

Results

Reanalysis of TCGA followed by GO enrichment analysis revealed that homeobox genes were highly expressed in advanced-stage EC. Among the identified genes, KM plotter analysis showed that high LIM1 expression was associated with a significantly poorer prognosis in EC. Additionally, LIM1 expression was significantly higher in high-grade EC cell lines, HEC50B cells than Ishikawa cells. Knockdown of LIM1 showed reduced cell proliferation, migration and invasion in HEC50B cells. Xenograft experiments revealed that tumor growth was significantly suppressed in LIM1-KD cells. IPA of RNA-seq data using LIM-KD cells predicted that the mRNA expression of CREB signaling-related genes was suppressed. Indeed, phosphorylation of CREB was decreased in LIM1-KD cells and LIM1-KD cells derived tumors. HEC50B cells treated by CREB inhibitors showed suppression of cell proliferation.

Conclusion and discussion

Collectively, these results suggested that high LIM1 expression contributed to tumor growth via CREB signaling in EC. Inhibition of LIM1 or its downstream molecules would be new therapeutic strategies for EC.

The impact of glutamine deprivation on the expression of MEIS3, SPAG4, LHX1, LHX2, and LHX6 genes in ERN1 knockdown U87 glioma cells

Objective. The aim of the current study was to investigate the expression of genes encoded homeobox proteins such as MEIS3 (Meis homeobox 3), SPAG4 (sperm associated antigen 4), LHX1 (LIM homeobox 1), LHX2, and LHX6 in U87 glioma cells in response to glutamine deprivation in control glioma cells and cells with knockdown of ERN1 (endoplasmic reticulum to nucleus signaling 1), the major pathway of the endoplasmic reticulum stress signaling, for evaluation of a possible dependence on the expression of these important regulatory genes from glutamine supply and ERN1 signaling. Methods. The expression level of MEIS3, SPAG4, LHX, LHX2, and LHX6 genes was studied by real-time quantitative polymerase chain reaction in control U87 glioma cells (transfected by vector) and cells with ERN1 knockdown after exposure to glutamine deprivation. Results. It was shown that the expression level of MEIS3 and LHX1 genes was up-regulated in control glioma cells treated by glutamine deprivation. At the same time, the expression level of three other genes (LHX2, LHX6, and SPAG4) was down-regulated. Furthermore, ERN1 knockdown significantly modified the effect of glutamine deprivation on LHX1 gene expression in glioma cells, but did not change significantly the sensitivity of all other genes expression to this experimental condition. Conclusion. The results of this investigation demonstrate that the exposure of U87 glioma cells under glutamine deprivation significantly affected the expression of all genes studied encoding the homeobox proteins and that this effect of glutamine deprivation was independent of the endoplasmic reticulum stress signaling mediated by ERN1, except LHX1 gene.

LHX1 as a potential biomarker regulates EMT induction and cellular behaviors in uterine corpus endometrial carcinoma

OBJECTIVES

To investigate the expression of LHX1 and its role as a biomarker in the diagnosis and prognosis of Uterine Corpus Endometrial Carcinoma (UCEC).

METHODS

The Cancer Genome Atlas (TCGA) database was used to detect the expression level of LHX1 in UCEC cells and tissues, and to find out the effect of LHX1 on prognosis. Co-expressed genes were then identified by Spearman correlation analysis, and the protein-protein interaction network was constructed using Cytoscape software. The R "clusterProfiler" package was used to conduct Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. A series of in vitro experiments were performed to evaluate LHX1 expression and detect UCEC cell proliferation, invasion, and migration. Western blotting was used to determine the effect of LHX1 on expression levels of Epithelial-Mesenchymal Transition (EMT)-related proteins.

RESULTS

LHX1 was upregulated in UCEC tissues and correlated with poor overall survival and disease-specific survival outcomes. Functional enrichment analysis suggested that genes co-expressed with LHX1 were enriched in cell adhesion. The expression of LHX1 was positively correlated with the expression levels of genes related to EMT induction and invasion. LHX1 can enhance the proliferation, migration, and invasion activities of UCEC cells in vitro, and alter the expression levels of EMT-related proteins.

CONCLUSION

LHX1 expression was highly upregulated in UCEC cells and tissues, which was correlated with the prognosis of patients with UCEC. LHX1 may regulate UCEC progression at least in part by modulating EMT induction.

KLF2 inhibits cancer cell migration and invasion by regulating ferroptosis through GPX4 in clear cell renal cell carcinoma

The metastatic dissemination and underlying mechanisms of clear cell renal cell carcinoma (ccRCC) remain insufficiently understood. In this study, we identified the essential role of KLF2 in suppressing the metastasis of ccRCC. Downregulation of KLF2 detected by immunohistochemistry in primary metastatic ccRCC was remarkably related to poor clinical outcomes. Overexpression of KLF2 in vitro inhibited growth, migration and invasion of RCC cells. Analysis of clinical specimens revealed that there is a close correlation between KLF2 and GPX4 in ccRCC. Mechanistically, KLF2 deficiency is sufficient to inhibit ferroptosis on account of the impairment of transcriptional repression of GPX4 and thus promotes the migration and invasion of RCC cells. Reverting KLF2 expression in vivo decreased pulmonary metastatic lesions and prolonged life span of mice, whereas GPX4 overexpression reversed these properties. Overall, our results established a novel critical pathway that drives human ccRCC invasion and metastasis, which could be a promising target regarding to the therapies of advanced ccRCC in the clinic.

ERN1 knockdown modifies the effect of glucose deprivation on homeobox gene expressions in U87 glioma cells

OBJECTIVE

The aim of the present investigation was to study the expression of genes encoding homeobox proteins ZEB2 (zinc finger E-box binding homeobox 2), TGIF1 (TGFB induced factor homeobox 1), SPAG4 (sperm associated antigen 4), LHX1 (LIM homeobox 1), LHX2, LHX6, NKX3-1 (NK3 homeobox 1), and PRRX1 (paired related homeobox 1) in U87 glioma cells in response to glucose deprivation in control glioma cells and cells with knockdown of ERN1 (endoplasmic reticulum to nucleus signaling 1), the major pathway of the endoplasmic reticulum stress signaling, for evaluation of it possible significance in the control of glioma growth through ERN1 signaling and chemoresistance.

METHODS

The expression level of homeobox family genes was studied in control (transfected by vector) and ERN1 knockdown U87 glioma cells under glucose deprivation condition by real-time quantitative polymerase chain reaction.

RESULTS

It was shown that the expression level of ZEB2, TGIF1, PRRX1, and LHX6 genes was up-regulated in control glioma cells treated by glucose deprivation. At the same time, the expression level of three other genes (NKX3-1, LHX1, and LHX2) was down-regulated. Furthermore, ERN1 knockdown of glioma cells significantly modified the effect glucose deprivation condition on the expression almost all studied genes. Thus, treatment of glioma cells without ERN1 enzymatic activity by glucose deprivation condition lead to down-regulation of the expression level of ZEB2 and SPAG4 as well as to more significant up-regulation of PRRX1 and TGIF1 genes. Moreover, the expression of LHX6 and NKX3-1 genes lost their sensitivity to glucose deprivation but LHX1 and LHX2 genes did not change it significantly.

CONCLUSIONS

The results of this investigation demonstrate that ERN1 knockdown significantly modifies the sensitivity of most studied homeobox gene expressions to glucose deprivation condition and that these changes are a result of complex interaction of variable endoplasmic reticulum stress related and unrelated regulatory factors and contributed to glioma cell growth and possibly to their chemoresistance.

Activation-Induced Cytidine Deaminase Expression Facilitates the Malignant Phenotype and Epithelial-to-Mesenchymal Transition in Clear Cell Renal Cell Carcinoma

Although advances have been made in the development of antiangiogenesis targeted therapy and surgery, metastatic clear cell renal cell carcinoma (ccRCC) is still incurable. Activation-induced cytidine deaminase (AID) is mainly expressed in a variety of germ and somatic cells, and induces somatic hypermutation and class-switch recombination, playing a vital role in antibody diversification. We confirmed that AID was expressed at a higher level in ccRCC tissues than in the corresponding nontumor renal tissues. We explored the impact of AID on ccRCC proliferation, invasion, and migration. In 769-p and 786-0 cells, expression of an AID-specific short hairpin RNA significantly reduced AID expression, which markedly inhibited tumor cell invasion, proliferation, and migration. Previous studies showed that AID is associated with Wnt ligand secretion mediator (WLS/GPR177), cyclin-dependent kinase 4 (CDK4), and stromal cell-derived factor-1 (SDF-1/CXCL12) regulation, which was further confirmed in human ccRCC tissues. Therefore, we studied the relationship between AID and these three molecules, and the impact of AID on epithelial-to-mesenchymal transition in ccRCC. WLS/GPR177, SDF-1/CXCL12, and CDK4 were sensitive to 5-azacytidine (a DNA demethylation agent), which reverted the inhibition of carcinogenesis caused by AID repression. In summary, AID is an oncogene that might induce tumorigenesis through DNA demethylation. Targeting AID may represent a novel therapeutic approach to treat metastatic ccRCC.

Chemotherapy exacerbates ovarian cancer cell migration and cancer stem cell-like characteristics through GLI1

BACKGROUND

Despite the great clinical response to the first-line chemotherapeutics, metastasis still happens among most of the ovarian cancer patients within 2 years.

METHODS

Using multiple human ovarian cancer cell lines, a transwell co-culture system of the carboplatin or VP-16-challenged feeder and receptor cells was established to demonstrate the chemotherapy-exacerbated migration. The migration and cancer stem cell (CSC)-like characteristics were determined by wound healing, transwell migration, flow cytometry and sphere formation. mRNA and protein expression were identified by qPCR and western blot. Bioinformatics analysis was used to investigate the differentially expressed genes. GLI1 expression in tissue samples was analysed by immunohistochemistry.

RESULTS

Chemotherapy was found to not only kill tumour cells, but also trigger the induction of CSC-like traits and the migration of ovarian cancer cells. EMT markers Vimentin and Snail in receptor cells were upregulated in the microenvironment of chemotherapy-challenged feeder cells. The transcription factor GLI1 was upregulated by chemotherapy in both clinical samples and cell lines. Follow-up functional experiments illustrated that inhibiting GLI1 reversed the chemotherapy-exacerbated CSC-like traits, including CD44 and CD133, as well as prevented the migration of ovarian cancer cells.

CONCLUSIONS

Targeting GLI1 may improve clinical benefits in the chemotherapy-exacerbated metastasis in ovarian cancer treatment.

Ex-Vivo Treatment of Tumor Tissue Slices as a Predictive Preclinical Method to Evaluate Targeted Therapies for Patients with Renal Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the third type of urologic cancer. At time of diagnosis, 30% of cases are metastatic with no effect of chemotherapy or radiotherapy. Current targeted therapies lead to a high rate of relapse and resistance after a short-term response. Thus, a major hurdle in the development and use of new treatments for ccRCC is the lack of good pre-clinical models that can accurately predict the efficacy of new drugs and allow the stratification of patients into the correct treatment regime. Here, we describe different 3D cultures models of ccRCC, emphasizing the feasibility and the advantage of ex-vivo treatment of fresh, surgically resected human tumor slice cultures of ccRCC as a robust preclinical model for identifying patient response to specific therapeutics. Moreover, this model based on precision-cut tissue slices enables histopathology measurements as tumor architecture is retained, including the spatial relationship between the tumor and tumor-infiltrating lymphocytes and the stromal components. Our data suggest that acute treatment of tumor tissue slices could represent a benchmark of further exploration as a companion diagnostic tool in ccRCC treatment and a model to develop new therapeutic drugs.

A panel of Transcription factors identified by data mining can predict the prognosis of head and neck squamous cell carcinoma

Background

Transcription factors (TFs) are responsible for the regulation of various activities related to cancer like cell proliferation, invasion, and migration. It is thought that, the measurement of TFs levels could assist in developing strategies for diagnosis and prognosis of cancer detection. However, due to lack of effective genome-wide tests, this cannot be carried out in clinical settings.

Methods

A complete assessment of RNA-seq data in samples of a head and neck squamous cell carcinoma (HNSCC) cohort in The Cancer Genome Atlas (TCGA) database was carried out. From the expression data of six TFs, a risk score model was developed and further validated in the GSE41613 and GSE65858 series. Potential functional roles were identified for the six TFs via gene set enrichment analysis.

Results

Based on our multi-TF signature, patients are stratified into high- and low-risk groups with significant variations in overall survival (OS) (median survival 2.416 vs. 5.934 years, log-rank test P < 0.001). The sensitivity and specificity evaluation of our multi-TF for 3-year OS in TCGA, GSE41613 and GSE65858 was 0.707, 0.679 and 0.605, respectively, demonstrating good reproducibility and robustness for predicting overall survival of HNSCC patients. Through multivariate Cox regression analyses (MCRA) and stratified analyses, we confirmed that the predictive capability of this risk score (RS) was not dependent on any of other factors like clinicopathological parameters.

Conclusions

With the help of a RS obtained from a panel of TFs expression signatures, effective OS prediction and stratification of HNSCC patients can be carried out.

The interaction of YBX1 with G3BP1 promotes renal cell carcinoma cell metastasis via YBX1/G3BP1-SPP1- NF-κB signaling axis

Background

Renal cell carcinoma (RCC) is a deadly urological tumor that remains largely incurable. Our limited understanding of key molecular mechanisms underlying RCC invasion and metastasis has hampered efforts to identify molecular drivers with therapeutic potential. With evidence from our previous study revealing that nuclear overexpression of YBX1 is associated with RCC T stage and metastasis, we investigated the effects of YBX1 in RCC migration, invasion, and adhesion, and then characterized its interaction with RCC-associated proteins G3BP1 and SPP1.

Methods

Renal cancer cell lines, human embryonic kidney cells, and clinical samples were analyzed to investigate the functional role of YBX1 in RCC metastasis. YBX1 knockdown cells were established via lentiviral infection and subjected to adhesion, transwell migration, and invasion assay. Microarray, immunoprecipitation, dual-luciferase reporter assay, and classical biochemical assays were applied to characterize the mechanism of YBX1 interaction with RCC-associated proteins G3BP1 and SPP1.

Results

Knockdown of YBX1 in RCC cells dramatically inhibited cell adhesion, migration, and invasion. Mechanistic investigations revealed that YBX1 interaction with G3BP1 upregulated their downstream target SPP1 in vitro and in vivo, which led to an activated NF-κB signaling pathway. Meanwhile, knockdown of SPP1 rescued the YBX1/G3BP1-mediated activation of NF-κB signaling pathway, and RCC cell migration and invasion. We further showed that YBX1 expression was positively correlated with G3BP1 and SPP1 expression levels in clinical RCC samples.

Conclusions

YBX1 interacts with G3BP1 to promote metastasis of RCC by activating the YBX1/G3BP1–SPP1–NF-κB signaling axis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1347-0) contains supplementary material, which is available to authorized users.