GREM2 maintains stem cell-like phenotypes in gastric cancer cells by regulating the JNK signaling pathway

CircZFR promotes pancreatic cancer progression through a novel circRNA-miRNA-mRNA pathway and stabilizing epithelial-mesenchymal transition protein

Pancreatic cancer (PC) ranks third in incidence and seventh in mortality among cancers worldwide. CircZFR has been implicated in various human cancers. Yet, how they affect PC progression is understudied. Herein, we demonstrated that circZFR was upregulated in PC tissues and cells, a feature that was correlated with the poor performance of patients with PC. Functional analyses elucidated that circZFR facilitated cell proliferation and enhanced tumorigenicity of PC. Moreover, we found that circZFR facilitated cell metastasis by differentially regulating the levels of proteins related to epithelial-mesenchymal transition (EMT). Mechanistic investigations revealed that circZFR sponged miR-375, thereby upregulating the downstream target gene, GREMLIN2 (GREM2). Additionally, circZFR knockdown resulted in attenuation of the JNK pathway, an effect that was reversed by GREM2 overexpression. Collectively, our findings implicate circZFR as a positive regulator of PC progression through the miR-375/GREM2/JNK axis.

The origin of gastric cancer stem cells and their effects on gastric cancer: Novel therapeutic targets for gastric cancer

Gastric cancer (GC) is one of the most prevalent malignancies and the most common causes of cancer-related mortality worldwide. Furthermore, the prognosis of advanced GC remains poor even after surgery combined with chemoradiotherapy. As a small group of cells with unlimited differentiation and self-renewal ability in GC, accumulating evidence shows that GC stem cells (GCSCs) are closely associated with the refractory characteristics of GC, such as drug resistance, recurrence, and metastasis. With the extensive development of research on GCSCs, GCSCs seem to be promising therapeutic targets for GC. However, the relationship between GCSCs and GC is profound and intricate, and its mechanism of action is still under exploration. In this review, we elaborate on the source and key concepts of GCSCs, systematically summarize the role of GCSCs in GC and their underlying mechanisms. Finally, we review the latest information available on the treatment of GC by targeting GCSCs. Thus, this article may provide a theoretical basis for the future development of the novel targets based on GCSCs for the treatment of GC.

Development of a SETD2-related immune prognostic signature in clear cell renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a malignant tumor of urinary system, and clear cell RCC (ccRCC) is the major pathological subtype. A high-frequency mutation in SETD2 gene is related to the occurrence, development, and poor prognosis of RCC.

OBJECTIVE

The research of immune-related genes (IRGs) is important to the success of immunotherapy in RCC. The aim of this study was to develop SETD2-related immune prognostic signature (IPS) potentially useful in the prognosis prediction of ccRCC.

METHODS

The expression profile, mutation profile, and clinical data related to ccRCC were obtained from the TCGA (Cancer Genome Atlas) and cBioPortal databases. The data of IRGs were downloaded from the ImmPort database.

RESULTS

An IPS with 5 genes (PDIA2, PAEP, AMELX, GREM2, and INHA) was constructed by analyzing the correlation between prognosis data and IRGs associated with ccRCC patients with wild type and mutant SETD2 genes. The clinical utility of the IPS and its relationship with immune microenvironment were also studied.

CONCLUSIONS

According to the results of this study, the IPS can be a promising biomarker of ccRCC to guide its prognosis and treatment.

CTRP3 alleviates cardiac ischemia/reperfusion injury via LAMP1/JIP2/JNK signaling pathway

Background: C1q/tumor necrosis factor-related protein 3 (CTRP3) has been reported to be a crucial regulator in myocardial infarction. Nevertheless, the potential molecular mechanism of CTRP3 in ischemia/reperfusion (I/R) injury remains largely unclear.

Methods: The cell model of myocardial I/R injury was established by oxygen-glucose deprivation/reoxygenation (OGD/R) of rat cardiomyocyte H9C2. Expression of CTRP3 and lysosomal-associated membrane protein 1 (LAMP1) was detected in H9C2 cells treated with oxygen-glucose deprivation/reoxygenation (OGD/R). H9C2 cells were transfected with overexpression plasmids of CTRP3 (pcDNA-CTRP3) and LAMP1 (pcDNA-LAMP1), or CTRP3 small interfering RNA (si-CTRP3) or/and pcDNA-LAMP1, and cell proliferation, apoptosis and oxidative stress were testified. Co-IP assay was performed to validate the relationship among CTRP3, LAMP1 and JIP2. The role of CTRP3 and LAMP1 in JIP2/JNK pathway was evaluated with Western blot assay. Furthermore, in vivo myocardial I/R injury model was constructed to investigate the effect of CTRP3.

Results: Overexpression of CTRP3 and LAMP1 both significantly promoted cell proliferation, inhibited apoptosis and the production of reactive oxygen species (ROS), malondialdehyde (MAD) and cardiac troponin (cTn-I), while silencing CTRP3 exerted the opposite effects, and LAMP1 overexpression reversed the effect of silencing CTRP3 on the aspects above. CTRP3 interacted with LAMP1, and both CTRP3 and LAMP1 bound with JIP2. SP600125 (JNK inhibitor) could restore the effects of CTRP3 or LAMP1 overexpression on the expression of JIP2 and phosphorylated-JNK (p-JNK), proliferation and apoptosis. Moreover, overexpression of CTRP3 improved cardiac I/R injury in vivo.

Conclusion: CTRP3 alleviates cardiac I/R injury by elevating LAMP1 and activating JIP2/JNK signaling pathway, which may serve as a potential therapeutic target for I/R injury.

A novel mechanism for C1GALT1 in the regulation of gastric cancer progression

Background

Gastric cancer (GC) is a highly aggressive and lethal disease around the world. High expression of core 1 β 1, 3-galactosyltransferase 1 (C1GALT1), the primary enzyme responsible for protein O-glycosylation, plays a critical role in gastric carcinogenesis. However, proteins that can be O-glycosylated by C1GALT1 in GC have not been completely elucidated. Also, the mechanism leading to its upregulation in GC is currently unknown.

Results

Using public databases and our patient samples, we confirmed that C1GALT1 expression was upregulated at both the mRNA and protein levels in GC tissues. Elevated expression of C1GALT1 protein was closely associated with advanced TNM stage, lymph node metastasis, tumor recurrence, and poor overall survival. With gain- and loss-of-function approaches, we demonstrated that C1GALT1 promoted GC cell proliferation, migration, and invasion. By employing lectin pull-down assay and mass spectrometry, integrin α5 was identified as a new downstream target of C1GALT1 in GC. C1GALT1 was able to modify O-linked glycosylation on integrin α5 and thereby modulate the activation of the PI3K/AKT pathway. Functional experiments indicated that integrin α5 inhibition could reverse C1GALT1-mediated tumor growth and metastasis both in vitro and in vivo. Moreover, transcription factor SP1 was found to bind to the C1GALT1 promoter region and activated its expression. Further investigation proved that miR-152 negatively regulated C1GALT1 expression by directly binding to its 3′ -UTR.

Conclusions

Our findings uncover a novel mechanism for C1GALT1 in the regulation of GC progression. Thus, C1GALT1 may serve as a promising target for the diagnosis and treatment of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00678-2.

Gremlin2 Activates Fibroblasts to Promote Pulmonary Fibrosis Through the Bone Morphogenic Protein Pathway

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease causing unremitting extracellular matrix deposition. Transforming growth factor-β (TGF-β) superfamily involves bone morphogenetic proteins (BMPs) and TGF-β, and the balance between the activation of TGF-β-dependent SMADs (Smad2/3) and BMP-dependent SMADs (Smad1/5/8) is essential for fibrosis process. GREM2, initially identified as a TGF-β-inducible gene, encodes a small secreted glycoprotein belonging to a group of matricellular proteins, its role in lung fibrosis is not clear. Here, we identified Gremlin2 as a key regulator of fibroblast activation. Gremlin2 was highly expressed in the serum and lung tissues in IPF patients. Bleomycin-induced lung fibrosis model exhibited high expression of Gremlin2 in the bronchoalveolar lavage fluid (BALF) and lung tissue. Isolation of primary cells from bleomycin-induced fibrosis lung showed a good correlation of Gremlin2 and Acta2 (α-SMA) expressions. Overexpression of Gremlin2 in human fetal lung fibroblast 1 (HFL-1) cells increased its invasion and migration. Furthermore, Gremlin2 regulates fibrosis functions through mediating TGF-β/BMP signaling, in which Gremlin2 may activate TGF-β signaling and inhibit BMP signaling. Therefore, we provided in vivo and in vitro evidence to demonstrate that Gremlin2 may be a potential therapeutic target for the treatment of IPF.

Reciprocal interplay between asporin and decorin: Implications in gastric cancer prognosis

Effective patient prognosis necessitates identification of novel tumor promoting drivers of gastric cancer (GC) which contribute to worsened conditions by analysing TCGA-gastric adenocarcinoma dataset. Small leucine-rich proteoglycans, asporin (ASPN) and decorin (DCN), play overlapping roles in development and diseases; however, the mechanisms underlying their interplay remain elusive. Here, we investigated the complex interplay of asporin, decorin and their interaction with TGFβ in GC tumor and corresponding normal tissues. The mRNA levels, protein expressions and cellular localizations of ASPN and DCN were analyzed using real-time PCR, western blot and immunohistochemistry, respectively. The protein-protein interaction was predicted by in-silico interaction analysis and validated by co-immunoprecipitation assay. The correlations between ASPN and EMT proteins, VEGF and collagen were achieved using western blot analysis. A significant increase in expression of ASPN in tumor tissue vs. normal tissue was observed in both TCGA and our patient cohort. DCN, an effective inhibitor of the TGFβ pathway, was negatively correlated with stages of GC. Co-immunoprecipitation demonstrated that DCN binds with TGFβ, in normal gastric epithelium, whereas in GC, ASPN preferentially binds TGFβ. Possible activation of the canonical TGFβ pathway by phosphorylation of SMAD2 in tumor tissues suggests its role as an intracellular tumor promoter. Furthermore, tissues expressing ASPN showed unregulated EMT signalling. Our study uncovers ASPN as a GC-promoting gene and DCN as tumor suppressor, suggesting that ASPN can act as a prognostic marker in GC. For the first time, we describe the physical interaction of TGFβ with ASPN in GC and DCN with TGFβ in GC and normal gastric epithelium respectively. This study suggests that prevention of ASPN-TGFβ interaction or overexpression of DCN could serve as promising therapeutic strategies for GC patients.

Functional characterization of ATF1, GREM2 AND WNT10B variants associated with tooth agenesis

OBJECTIVE

To determine the functional effects of ATF1, WNT10B and GREM2 gene variants identified in individuals with tooth agenesis (TA).

SETTINGS AND SAMPLE POPULATION

Stem cells from human exfoliated deciduous teeth (SHED) were used as an in vitro model system to test the effect of TA-associated variants.

MATERIALS AND METHODS

Plasmid constructs containing reference and mutant alleles for ATF1 rs11169552, WNT10B rs833843 and GREM2 rs1414655 variants were transfected into SHED for functional characterization of variants. Allele-specific changes in gene transcription activity, protein expression, cell migration and proliferation, and expression of additional tooth development genes (MSX1, PAX9 and AXIN2) were evaluated. Data analyses were performed using Student's t-test. P-values ≤ .05 were considered statistically significant.

RESULTS

Mutant variants resulted in significantly decreased transcriptional activity of respective genes (P < 0.05), although no changes in protein localization were noted. Expression of MSX1 was significantly decreased in ATF1- and GREM2-mutant cells, whereas PAX9 or AXIN2 mRNA expression was not significantly altered. Mutant WNT10B had no significant effect on the expression of additional TA genes. ATF1- and GREM2-mutant cells presented increased cell migration. Cell proliferation was also affected with all three mutant alleles.

CONCLUSIONS

Our results demonstrate that ATF1, WNT10B and GREM2 mutant alleles have modulatory effects on gene/protein function that may contribute to TA.

Nomogram Personalizes and Visualizes the Overall Survival of Patients with Triple-Negative Breast Cancer Based on the Immune Genome

Background

Triple-negative breast cancer (TNBC) is usually poorly differentiated, highly invasive, susceptible to distant metastasis, and less responsive to endocrine and targeted therapy. However, immunotherapy is a promising treatment for TNBC patients recently.

Methods

The prognostic value of immune-related genes (IRGs) was explored by using RNA sequencing and microarray data of 123 and 107 TNBC patients from TCGA and GEO databases, respectively.

Results

In TCGA database, GO and KEGG pathway analysis of 119 differential IRGs indicated that they actively participate in the interaction of cytokines and receptors. A nomogram model constructed by the prognosis-related CCL25, IL29, TDGF3, GPR44, and GREM2 in the IRGs could personalize and visualize the 1-, 2-, 3-, 4-, and 5-year overall survival (OS) of TNBC patients. Moreover, TNBC patients could be defined as low-risk (risk score < 194) or high-risk (risk score ≥ 194) cohorts based on the risk score derived from the nomogram model. The results could be validated by the GSE58812 dataset. Furthermore, the risk score was an independent risk factor for TNBC patients (HR = 1.019, 95% CI 1.012-1.027, p < 0.001) and was positively related to stage (p = 0.017). Interestingly, the risk score could reflect the infiltration of B cells, CD4+ T cells, CD8+ T cells, dendritic cells, and neutrophils.

Conclusion

These findings provided a reference for personalized OS prediction in TNBC patients and might be potential immune biomarkers for designing novel therapy.

Extracellular BMP Antagonists, Multifaceted Orchestrators in the Tumor and Its Microenvironment

The bone morphogenetic proteins (BMPs), a subgroup of the transforming growth factor-β (TGF-β) superfamily, are involved in multiple biological processes such as embryonic development and maintenance of adult tissue homeostasis. The importance of a functional BMP pathway is underlined by various diseases, including cancer, which can arise as a consequence of dysregulated BMP signaling. Mutations in crucial elements of this signaling pathway, such as receptors, have been reported to disrupt BMP signaling. Next to that, aberrant expression of BMP antagonists could also contribute to abrogated signaling. In this review we set out to highlight how BMP antagonists affect not only the cancer cells, but also the other cells present in the microenvironment to influence cancer progression.

Comprehensive analysis of transcriptome data for identifying biomarkers and therapeutic targets in head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancy worldwide. Accumulating evidences have highlighted the importance of transcriptome data during HNSCC tumorigenesis. The aim of this study was to identify significant genes as effective biomarkers for HNSCC and constructed miRNA-mRNA regulatory network for a more comprehensive understanding of the underlying molecular mechanisms.

Methods

A total of four independent microarrays conducted on HNSCC samples were downloaded from the Gene Expression Omnibus (GEO) and analyzed through R software. FunRich was applied to predict potential transcription factors and targeted genes of miRNAs. Protein-protein interaction (PPI) network and miRNA-mRNA regulatory network were constructed in Cytoscape. Additionally, the database for annotation, visualization, and integrated discovery (DAVID) was utilized to perform GO and KEGG pathway enrichment analyses. Validation of gene expression levels was conducted by online databases and qPCR experiments.

Results

A total of 35 and 193 differentially expressed miRNAs (DEMs) and mRNAs (DEGs) were screened out by the limma package in R. The interactive network of the overlapping DEGs presented three significant modules and ten hub genes (FN1, MMP3, SPP1, STAT1, LOX, CXCL5, CXCL11, ISG15, IFIT3, and RSAD2). Predicted target genes of DEMs were visualized in Cytoscape and six miRNA-mRNA regulatory pairs were identified. Further validation demonstrated the upregulation of SLC16A1 and COL4A1 in HNSCC.

Conclusions

We performed an integrated and comprehensive bioinformatics analysis of miRNAs and mRNAs in HNSCC, contributing to explore the underlying regulatory mechanisms and to identify genetic biomarkers and therapeutic targets for HNSCC.