Prognostic significance of SOCS3 and its biological function in colorectal cancer

5-AZA Upregulates SOCS3 and PTPN6/SHP1, Inhibiting STAT3 and Potentiating the Effects of AG490 against Primary Effusion Lymphoma Cells

Epigenetic modifications, including aberrant DNA methylation occurring at the promoters of oncogenes and oncosuppressor genes and histone modifications, can contribute to carcinogenesis. Aberrant methylation mediated by histone methylatransferases, alongside histones, can affect methylation of proteins involved in the regulation of pro-survival pathways such as JAK/STAT and contribute to their activation. In this study, we used DNA or histone demethylating agents, 5-Azacytidine (5-AZA) or DS-3201 (valemetostat), respectively, to treat primary effusion lymphoma (PEL) cells, alone or in combination with AG490, a Signal transducer and activator of transcription 3 (STAT3) inhibitor. Cell viability was investigated by trypan blue assay and FACS analysis. The molecular changes induced by 5-AZA and/or AG490 treatments were investigated by Western blot analysis, while cytokine release by PEL cells treated by these drugs was evaluated by Luminex. Statistical analyses were performed with Graphpad Prism® software (version 9) and analyzed by Student's t test or a nonparametric one-way ANOVA test. The results obtained in this study suggest that 5-AZA upregulated molecules that inhibit STAT3 tyrosine phosphorylation, namely Suppressor of Cytokine Signaling 3 (SOCS3) and tyrosine-protein phosphatase non-receptor type (PTPN) 6/Src homology region 2 domain-containing phosphatase-1 (SHP-1), reducing STAT3 activation and downregulating several STAT3 pro-survival targets in PEL cells. As this lymphoma is highly dependent on the constitutive activation of STAT3, 5-AZA impaired PEL cell survival, and when used in combination with AG490 JAK2/STAT3 inhibitor, it potentiated its cytotoxic effect. Differently from 5-AZA, the inhibition of the EZH1/2 histone methyltransferase by DS-3201, reported to contribute to STAT3 activation in other cancers, slightly affected STAT3 phosphorylation or survival in PEL cells, either alone or in combination with AG490. This study suggests that 5-AZA, by upregulating the expression level of SOCS3 and PTPN6/SHP1, reduced STAT3 activation and improved the outcome of treatment targeting this transcription factor in PEL cells.

DNMTs-mediated SOCS3 methylation promotes the occurrence and development of AML

OBJECTIVES

As a tumor suppressor gene, SOCS3 inhibits the growth of tumor cells by regulating JAK/STAT signaling pathway through negative feedback. This study aimed to investigate the biological function and mechanism of SOCS3 methylation mediated by DNMTs in the development of AML.

METHODS

Bone marrow samples were collected from 70 AML patients and 20 healthy volunteers. The expression and methylation status of each gene were detected by RT-qPCR, western blot and MS-PCR, and the growth and apoptosis rate of leukemia cell lines were detected by CCK-8 and flow cytometry. The effects of changes in SOCS3 gene expression and methylation status of AML cell lines were observed by gene transfection and gene knockdown.

RESULTS

The methylation rate of SOCS3 in AML initial treatment group was significantly higher than that in the remission group and the normal control group (60% vs. 0%, 0%). The expression of SOCS3 in the SOCS3 methylation group was significantly lower than that in the non-methylated group and control group, while the expression of DNMT1, DNMT3a, p-JAK2, p-STAT3 and p-STAT5 were significantly higher than those in the non-methylated group and control group. Demethylation treatment, SOCS3 transfection and DNMT3a knockdown could up-regulate the expression of SOCS3, which decreased the proliferation and increased the apoptosis of leukemia cell lines.

CONCLUSION

SOCS3 methylation mediated by DNMTs promotes the occurrence and development of AML and can be used as a potential biomarker for the diagnosis and efficacy evaluation of AML.

MicroRNAs Regulate Tumorigenesis by Downregulating SOCS3 Expression: An In silico Approach

Tumor microenvironment is characterized by the occurrence of significant changes due to disrupted signaling pathways that affect a broad spectrum of cellular activities such as proliferation, differentiation, signaling, invasiveness, migration, and apoptosis. Similarly, a downregulated suppressor of cytokine signaling 3 (SOCS3) promotes increased JAK/STAT function due to aberrant cytokine signaling, which results in increased cell proliferation, differentiation, and migration. Multiple carcinomas including breast cancer, prostate cancer, hepatocellular carcinoma, pancreatic cancer, and colorectal cancer involve the disruption of SOCS3 expression due to microRNA overexpression. MicroRNAs are small, conserved, and non-coding RNA molecules that regulate gene expression through post-transcriptional inhibition and mRNA destabilization. The aim of this study was to identify putative microRNAs that interact with SOCS3 and downregulate its expression. In this study, miRWalk, TargetScan, and miRDB were used to identify microRNAs that interact with SOCS3, whereas RNA22 was utilized to identify the binding sites of 238 significant microRNAs. The tertiary structures of shortlisted microRNAs and SOCS3 regions were predicted through MC Sym and RNAComposer, respectively. For molecular docking, HDOCK was used, which predicted 80 microRNA-messengerRNA complexes and the interactions of the top 5 shortlisted complexes were assessed. The complexes were shortlisted on the basis of least binding affinity score and maximum confidence score. This study identifies the interactions of known (miR-203a-5p) and novel (miR-6756-5p, miR-6732-5p, miR-1203, miR-6887-5p) microRNAs with SOCS3 regions due to their maximum interactions. Identifying the interactions of these microRNAs with SOCS3 will significantly advance the understanding of oncomiRs (miRNAs that are associated with cancer development) in tumor development due to their influence on SOCS3 expression. These insights will assist in future studies to understand the significance of miRNA-SOCS3-associated tumor development and progression.

MiR-221 Regulates Suppressors of Cytokine Signaling 3-Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (SOCS3-JAK2/STAT3) Pathway and Affects Thyroid Cancer Cell Proliferation and Apoptosis

Objective: Suppressors of cytokine signaling 3 (SOCS3) negatively regulates JAK-STAT signaling. Bioinformatics analysis showed a targeted relationship between miR-221 and SOCS3 mRNA 3′-UTR. This study investigated whether miR-221 regulates SOCS3 expression and affects thyroid cancer cells. Methods: Dual-luciferase reporter gene experiments verified the relationship between miR-221 and SOCS3. The tumor tissues and adjacent tissues of patients with thyroid cancer were collected to detect miR-221 and SOCS3 level. Thyroid cancer cell line KTC-1 cells were assigned into miR-NC group and miR-221 inhibitor group followed by analysis of SOCS3, p-JAK2, and p-STAT3 level by Real-time PCR, cell apoptosis and cell proliferation by flow cytometry and cell invasion by Transwell assay. Results: Compared with adjacent tissues, miR-221 level in tumor tissues was increased, and SCOS3 mRNA level was decreased. There was a targeted relationship between miR-221 and SOCS3 mRNA. MiR-221 level in KTC-1 and TPC-1 cells was increased, while SOCS3 mRNA level was decreased. MiR-221 inhibitor can significantly upregulate SOCS3 mRNA and protein in KTC-1 cells, reduce the expression of p-JAK2, p-STAT3 protein, increase cell apoptosis, and reduce cell proliferation and invasion. Conclusion: The increased miR-221 and decreased SOCS3 expression are related to thyroid cancer pathogenesis. MiR-221 can inhibit the expression of SOCS3, affect JAK-STAT signaling activity, and regulate the proliferation and apoptosis of thyroid cancer cells.

Semantic clustering analysis of E3-ubiquitin ligases in gastrointestinal tract defines genes ontology clusters with tissue expression patterns

Background

Ubiquitin ligases (Ub-ligases) are essential intracellular enzymes responsible for the regulation of proteome homeostasis, signaling pathway crosstalk, cell differentiation and stress responses. Individual Ub-ligases exhibit their unique functions based on the nature of their substrates. They create a complex regulatory network with alternative and feedback pathways to maintain cell homeostasis, being thus important players in many physiological and pathological conditions. However, the functional classification of Ub-ligases needs to be revised and extended.

Methods

In the current study, we used a novel semantic biclustering technique for expression profiling of Ub-ligases and ubiquitination-related genes in the murine gastrointestinal tract (GIT). We accommodated a general framework of the algorithm for finding tissue-specific gene expression clusters in GIT. In order to test identified clusters in a biological system, we used a model of epithelial regeneration. For this purpose, a dextran sulfate sodium (DSS) mouse model, following with in situ hybridization, was used to expose genes with possible compensatory features. To determine cell-type specific distribution of Ub-ligases and ubiquitination-related genes, principal component analysis (PCA) and Uniform Manifold Approximation and Projection technique (UMAP) were used to analyze the Tabula Muris scRNA-seq data of murine colon followed by comparison with our clustering results.

Results

Our established clustering protocol, that incorporates the semantic biclustering algorithm, demonstrated the potential to reveal interesting expression patterns. In this manner, we statistically defined gene clusters consisting of the same genes involved in distinct regulatory pathways vs distinct genes playing roles in functionally similar signaling pathways. This allowed us to uncover the potentially redundant features of GIT-specific Ub-ligases and ubiquitination-related genes. Testing the statistically obtained results on the mouse model showed that genes clustered to the same ontology group simultaneously alter their expression pattern after induced epithelial damage, illustrating their complementary role during tissue regeneration.

Conclusions

An optimized semantic clustering protocol demonstrates the potential to reveal a readable and unique pattern in the expression profiling of GIT-specific Ub-ligases, exposing ontologically relevant gene clusters with potentially redundant features. This extends our knowledge of ontological relationships among Ub-ligases and ubiquitination-related genes, providing an alternative and more functional gene classification. In a similar way, semantic cluster analysis could be used for studding of other enzyme families, tissues and systems.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02265-2.

Structure-Activity Relationship Investigations of Novel Constrained Chimeric Peptidomimetics of SOCS3 Protein Targeting JAK2

SOCS3 (suppressor of cytokine signaling 3) protein suppresses cytokine-induced inflammation and its deletion in neurons or immune cells increases the pathological growth of blood vessels. Recently, we designed several SOCS3 peptidomimetics by assuming as template structures the interfacing regions of the ternary complex constituted by SOCS3, JAK2 (Janus Kinase 2) and gp130 (glycoprotein 130) proteins. A chimeric peptide named KIRCONG chim, including non-contiguous regions demonstrated able to bind to JAK2 and anti-inflammatory and antioxidant properties in VSMCs (vascular smooth muscle cells). With the aim to improve drug-like features of KIRCONG, herein we reported novel cyclic analogues bearing different linkages. In detail, in two of them hydrocarbon cycles of different lengths were inserted at positions i/i+5 and i/i+7 to improve helical conformations of mimetics. Structural features of cyclic compounds were investigated by CD (Circular Dichroism) and NMR (Nuclear Magnetic Resonance) spectroscopies while their ability to bind to catalytic domain of JAK2 was assessed through MST (MicroScale Thermophoresis) assay as well as their stability in biological serum. Overall data indicate a crucial role exerted by the length and the position of the cycle within the chimeric structure and could pave the way to the miniaturization of SOCS3 protein for therapeutic aims.

Prognostic Significance of SOCS3 in Patients With Solid Tumors: A Meta-Analysis

Background

The identification of reliable biomarkers for predicting disease recurrence and the survival of patients with cancer is of great importance. Numerous previous studies have revealed that the abnormal expression of the suppressor of cytokine signaling 3 (SOCS3) was associated with patient outcomes. However, these results were inconsistent. The aim of the present study was to assess the prognostic value of SOCS3 in patients with solid tumors.

Methods

Studies focusing on the prognostic value of SOCS3 in solid tumors were searched for in the PubMed, Embase, Web of Science, and Scopus databases. We included studies that compared disease-free survival (DFS) and overall survival based on different levels of SOCS3. Other outcomes (e.g., Edmondson grading, tumor size, tumor vascular invasion, lymph node invasion, and distant metastasis) were also considered. The hazard ratio (HR)/risk ratio (RR) and corresponding 95% CI were determined.

Results

Twelve studies with 1,551 patients were included in this meta-analysis. The pooled analysis demonstrated that the higher expression of SOCS3 was significantly associated with better disease-free survival (HR:0.36, 95% CI:0.17–0.77, P < 0.001) and overall survival (HR:0.45, 95% CI:0.32–0.62, P < 0.001) compared with low expression. Moreover, SOCS3 expression was closely correlated with the Edmondson grading [odds ratio (OR):0.77, 95% CI:0.61–0.98, P = 0.033], vascular invasion (OR:0.63, 95% CI:0.52–0.78, P < 0.001), and distant metastasis (OR:0.73, 95% CI:0.51–1.03, P = 0.076). However, the levels of SOCS3 were not significantly associated with tumor size (OR:0.85, 95% CI:0.71–1.03, P = 0.090) and lymph node invasion (OR:0.73, 95% CI:0.51–1.03, P = 0.076).

Conclusion

Increased SOCS3 expression in tumor mass was associated with better DFS and OS, suggesting it might be a novel and reliable biomarker for predicting the risk of cancer recurrence and mortality.

Knockdown of miR-92a suppresses the stemness of colorectal cancer cells via mediating SOCS3

MiRNAs (microRNAs) participate in colorectal cancer (CRC) progression and act as potential biomarkers for CRC prognosis. In this study, we investigated the mechanisms of microRNA-92a (miR-92a) in CRC. Expressions of miR-92a and SOCS3 (Suppressor Of Cytokine Signaling 3) were investigated by qRT-PCR in CRC cell lines and 30 cases of CRC. The self-renewal capacity and proliferation of CRC stem cells were estimated by the sphere formation assay, EdU staining, and Flow cytometry analysis. Moreover, the interplay between miR-92a and SOCS3 in CRC cells was validated by luciferase reporter experiments. MiR-92a was found to be remarkably increased while SOCS3 was significantly downregulated in CRC tissues. Inhibition of miR-92a or SOCS3 attenuated the sphere formation capacity, decreased expressions of stemness-related proteins, and inhibited the proliferation of cancer stem-like cells. Knockdown of SOCS3 reversed the repressive impacts of miR-92a inhibitors on self-renewal and growth of CRC cancer stem cells. This study suggested that miR-92a functions as an oncogene of CRC through mediating the stemness of colorectal cancer cells by directly binding and repressing SOCS3.

Proteomimetics of Natural Regulators of JAK-STAT Pathway: Novel Therapeutic Perspectives

The JAK-STAT pathway is a crucial cellular signaling cascade, including an intricate network of Protein-protein interactions (PPIs) responsible for its regulation. It mediates the activities of several cytokines, interferons, and growth factors and transduces extracellular signals into transcriptional programs to regulate cell growth and differentiation. It is essential for the development and function of both innate and adaptive immunities, and its aberrant deregulation was highlighted in neuroinflammatory diseases and in crucial mechanisms for tumor cell recognition and tumor-induced immune escape. For its involvement in a multitude of biological processes, it can be considered a valuable target for the development of drugs even if a specific focus on possible side effects associated with its inhibition is required. Herein, we review the possibilities to target JAK-STAT by focusing on its natural inhibitors as the suppressor of cytokine signaling (SOCS) proteins. This protein family is a crucial checkpoint inhibitor in immune homeostasis and a valuable target in immunotherapeutic approaches to cancer and immune deficiency disorders.

Long noncoding RNA Meg3 sponges miR-708 to inhibit intestinal tumorigenesis via SOCS3-repressed cancer stem cells growth

BACKGROUND

Colorectal cancer (CRC) remains the most common gastrointestinal cancer and a leading cause of cancer deaths worldwide, with most showing pathologies indicating the malignant transformation of early stage intestinal stem cells. The long non-coding RNA Meg3, which functions as a tumor suppressor, has been reported to be abnormal in multiple tumorigenesis events; however, the underlying mechanism by which Meg3 contributes to the malignant proliferation of colonic stem cells remains unclear.

METHODS

We analyzed the expression levels of Meg3, miR-708, and SOCS3 in samples from Apc loss-of-function (Apc^min) mice and patients with CRC, particularly in colonic crypt cells. Apc^min mice and AMO/DSS-induced mice model (in vivo) and organoid culture system (in vitro) were used to explore the effect of the Meg3/miR-708/SOCS3 axis on tumorigenesis in the colon. In vitro, we performed RNApull-down, RNA immunoprecipitation, and luciferase reporter assays using DLD1 and RKO cell lines.

FINDINGS

The Meg3/miR-708/SOCS3 signaling axis plays a critical role in the early stage of CRC development. Our data showed Meg3 levels negatively correlate with miR-708 levels both in clinical samples and in the Apc^min mouse model, which indicated that Meg3 acts as a competitive endogenous RNA (ceRNA) of miR-708. Then, miR-708 served as an oncogene, inducing neoplasia in both Apc^min mice and cultured colonic organoids. Put together, miR-708 appears to promote malignant proliferation of colonic stem cells by targeting SOCS3/STAT3 signaling.

INTERPRETATION

These data revealed that Meg3 sponges miR-708 to inhibit CRC development via SOCS3-mediated repression of the malignant proliferation of colonic stem cells. The Meg3/miR-708/SOCS3 signaling axis provides potential targets for the diagnosis and treatment of CRC, particularly early stage CRC.

Emerging roles of suppressor of cytokine signaling 3 in human cancers

As a member of the suppressor of cytokine signaling (SOCS) family, SOCS3 is a cytokine-inducible protein that inhibits cytokine signaling in a variety of signaling pathways. Increasing evidence shows that SOCS3 regulates tumor development through multiple pathological and physiological processes. It is worth mentioning that SOCS3 negatively regulates JAK/STAT signaling by binding to JAK/cytokine receptors or phosphorylation docking sites on STAT receptors, thus preventing tumor cell proliferation and inhibiting tumor cell invasion and metastasis. The kinase inhibitory region KIR of SOCS3 is the key to JAK inhibition. In addition, SOCS3 may also regulate tumor progression through other molecules or signaling pathways, such as microRNAs (miRNAs), IL-6 and NF-κB signaling pathway. MicroRNAs inhibit SOCS3 expression by binding to the 3' untranslated region of SOCS3 mRNA, thus regulating tumor development processes, including tumor cell proliferation, invasion, metastasis, differentiation, cell cycle and apoptosis, as well as tumor metastasis and chemotherapy resistance. On the whole, SOCS3 acts as an inhibitor of the majority of tumors through various pathways. In the present review, the role of SOCS3 in multitudinous tumors was comprehensively summarized, the molecular mechanisms and modes of action of SOCS3 in tumors were discussed, and the association between SOCS3 expression and the clinical characteristics of patients with cancer were emphasized.

A methylation-based prognostic model predicts survival in patients with colorectal cancer

Background

To construct a model that could effectively predict the prognosis of colorectal cancer (CRC) by searching for methylated-differentially expressed genes (MDEGs).

Methods

We identified MDEGs through four databases from Gene Expression Omnibus (GEO) and annotated their functions via bioinformatics analysis. Subsequently, after adjusting for gender, age, and grading, multivariate Cox hazard analysis was utilized to select MDEGs interrelated with the prognosis of CRC, and LASSO analysis was utilized to fit the prediction model in the training set. Furthermore, another independent dataset was harnessed to verify the effectiveness of the model in predicting prognosis.

Results

In total, 252 hypomethylated and up-regulated genes and 132 hypermethylated and down-regulated genes were identified, 27 of which were correlated with the prognosis of CRC, and a 10-gene prognostic model was established after LASSO analysis. The overall survival rate could be effectively grouped into different risks by the median score of this model in the training set [risk ratio (HR) =2.27, confidence interval (95% CI), 1.69-3.13, P=8.15×10^-8], and the validity of its effect in predicting prognosis in CRC was verified in the validation dataset (HR =1.75, 95% CI, 1.15-2.70, P=9.32×10^-3).

Conclusions

Our model could effectively predict the overall survival rate of patients with CRC and provides potential application guidelines for its clinically personalized treatment.

The Emerging Role of Suppressors of Cytokine Signaling (SOCS) in the Development and Progression of Leukemia

Cytokines are pleiotropic signaling molecules that execute an essential role in cell-to-cell communication through binding to cell surface receptors. Receptor binding activates intracellular signaling cascades in the target cell that bring about a wide range of cellular responses, including induction of cell proliferation, migration, differentiation, and apoptosis. The Janus kinase and transducers and activators of transcription (JAK/STAT) signaling pathways are activated upon cytokines and growth factors binding with their corresponding receptors. The SOCS family of proteins has emerged as a key regulator of cytokine signaling, and SOCS insufficiency leads to constitutive activation of JAK/STAT signaling and oncogenic transformation. Dysregulation of SOCS expression is linked to various solid tumors with invasive properties. However, the roles of SOCS in hematological malignancies, such as leukemia, are less clear. In this review, we discuss the recent advances pertaining to SOCS dysregulation in leukemia development and progression. We also highlight the roles of specific SOCS in immune cells within the tumor microenvironment and their possible involvement in anti-tumor immunity. Finally, we discuss the epigenetic, genetic, and post-transcriptional modifications of SOCS genes during tumorigenesis, with an emphasis on leukemia.

microR-4449 Promotes Colorectal Cancer Cell Proliferation via Regulation of SOCS3 and Activation of STAT3 Signaling

Introduction

Dysregulation of microRNAs (miRNAs), which represented a critical level of gene expression modulation, regulated the development of colorectal cancer. However, the functions of numerous miRNAs remain unclear in colorectal cancer.

Methods

The microarray data of GSE115513 were retrieved; subsequently, the differentially expressed miRNAs between 411 colon tumors and 381 normal colon mucosa were analyzed. Real-time PCR (RT-qPCR) and bioinformatic analysis were applied to examine the expression of miR-4449 in collected colorectal tumors and published microarray data. The activity of signal transducer and activator of transcription 3 (STAT3) signaling was detected by Western blotting and RT-qPCR. Dual-Luciferase assay and bioinformatic analysis were used to confirm the interaction between suppressor of cytokine signaling 3 (SOCS3) and miR-4449. Loss of function and rescue assays were performed to study the involvement of miR-4449 and SOCS3 in cell proliferation and apoptosis of colorectal cancer.

Results

Herein, we identified miR-4449 as a novel upregulated miRNA in colorectal cancer. Our data suggested that miR-4449 downregulation blocked the proliferation of colorectal cancer cells accompanied with the elevation of cell apoptosis. Decreased expression of miR-4449 led to inactivation of STAT3 pathway as indicated by dephosphorylation of STAT3 and downregulation of STAT3 target genes, including vascular endothelial growth factor (VEGF), c-Myc, baculovirus inhibitor of apoptosis containing 5 (BIRC5). Furthermore, SOCS3, a negative regulator of STAT3 pathway, was found to be a target gene of miR-4449. The data also showed that the inactivation of STAT3 pathway by miR-4449 inhibitor was realized by targeting SOCS3. Moreover, the biological function of miR-4449 downregulation was reversed by SOCS3 knockdown in colorectal cancer cells.

Conclusion

The current study revealed that miR-4449 promoted cell proliferation of colorectal cancer and was a promising potential therapeutic target for colorectal cancer.

The Combination Therapy of Fluorouracil and Oxaliplatin Suppress the Progression of Colon Cancer Through miR-183-5p/SOCS3 Axis and Downregulating PD-L1

Purpose

The purpose of this study was to investigate the mechanism of combination of fluorouracil (FU) and oxaliplatin (OXA) on the progression of colon cancer via miR-183-5p/SOCS3 axis and regulating PD-L1.

Methods

HCT116 cells were treated with 4 μM OXA and 10.5 μM FU, or exogenous regulation of the expression of miR-183-5p, SOCS3 and PD-L1 in HCT116 cells. CCK-8 assay was employed to detect cell viability of HCT116 cells. Flow cytometry was performed to assess the apoptosis and cell cycle. The expression level of SOCS3, PD-L1, chemokines (CCL1, CCL4 and CCL7) and immune escapes related proteins (EGFR, STARD1 and STARD3) in HCT116 cells were assessed by Western blotting. In addition, dual-luciferase reporter gene was carried out to verify the targeted relationship between miR-183-5p with SOCS3.

Results

Our study demonstrated that the combination of OXA and FU remarkably suppressed proliferation, promoted apoptosis and arrest cells in G0/G1 phrase of HCT116 cells, and observably downregulated the expression of PD-L1, CCL1, CCL4, CCL7, EGFR, STARD1 and STARD3. Meanwhile, the combination of OXA and FU significantly downregulated miR-183-5p expression. Knockdown of miR-183-5p also repressed the proliferation, promoted apoptosis and arrest cells in G0/G1 phrase of HCT116 cells, and downregulated the expression of PD-L1, CCL1, CCL4, CCL7, EGFR, STARD1 and STARD3. In addition, our study proved that miR-183-5p upregulated PD-L1 by targeting downregulated SOCS3 expression. Finally, we demonstrated that the combination therapy of OXA and FU inhibited the proliferation, promote apoptosis and arrest cells in G0/G1 phrase by downregulating PD-L1 via miR-183-5p/SOCS3 axis.

Conclusion

The combination therapy of OXA and FU could suppress the malignant biological behavior, and the mechanism was realized by inhibiting PD-L1 through miR-183-5p/SOCS3 axis.

MiR-324/SOCS3 Axis Protects Against Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury and Regulates Myocardial Ischemia via TNF/NF-κB Signaling Pathway

We aimed at exploring the function of microRNA-324/cytokine signaling 3 (miR-324/SOCS3) axis in hypoxia/reoxygenation (H/R) -induced cardiomyocyte injury and its underlying mechanism. The differential expression genes were analyzed based on the GSE83500 and GSE48060 datasets from the Gene Expression Omnibus (GEO) database. Then, to conduct the function enrichment analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used. The upstream regulatory microRNAs (miRNAs) of the identified genes were predicted by miRanda, miRWalk, and TargetScan websites. MiR-324 expression was measured with quantitative real-time polymerase chain reaction (qRT-PCR). The target binding of miR-324 and SOCS3 was established by dual-luciferase reporter assay. Cardiomyocyte proliferation was analyzed by cell counting kit-8 (CCK-8) assay, whereas the apoptosis was investigated via flow cytometry. The expression of TNF pathway-related proteins was detected by western blot analysis. SOCS3 was upregulated in patients with myocardial infarction (MI), and function enrichment analyses proved that SOCS3 was enriched in TNF signaling pathway. Moreover, we found that miR-324 was the upstream regulatory miRNA of SOCS3 and negatively regulated SOCS3 expression. MiR-324 was downregulated in cardiomyocytes with H/R-induced injury, inhibiting cell proliferation. In the H/R model, SOCS3 suppresses cardiomyocyte proliferation, which was recovered by miR-324, and induces cell apoptosis, which was repressed by miR-324 via regulating the expression of cleaved caspase-3 and p P38-MAPK. MiR-324 upregulation decreased the protein levels of TNF-α, p-P65, and p-IκBα in cardiomyocytes that suffered from H/R, which was reversed with SOCS3 overexpression. MiR-324/SOCS3 axis could improve the H/R-induced injury of cardiomyocytes via regulating TNF/NF-κB signaling pathway, and this might provide a new therapy strategy for myocardial ischemia.

Malathion induced cancer-linked gene expression in human lymphocytes

BACKGROUND

Malathion is the most widely used organophosphate pesticide in agriculture. Increasing cancer incidence in agricultural workers and their children links to the exposure of malathion. Identification of genes involved in the process of carcinogenesis is essential for exploring the role of malathion. The alteration in gene expression by malathion in human lymphocytes has not been explored yet, although hematological malignancies are rampant in humans.

OBJECTIVE

This study investigates the malathion induced expression of cancer associated genes in human lymphocytes.

METHODS

Human lymphocyte viability and colony-forming ability were analyzed in malathion treated and control groups. Gene expression profile in control and malathion treated human lymphocytes were performed using a microarray platform. The genes which have significant functions and those involved in different pathways were analyzed using the DAVID database. Differential gene expression upon malathion exposure was validated by quantitative real-time (qRT)-PCR.

RESULTS

Malathion caused a concentration-dependent reduction in human lymphocyte viability. At low concentration (50 μg/mL) of malathion treatment, human lymphocytes were viable indicating that low concentration of malathion is not cytotoxic and induces the colony formation. Total of 659 genes (15%) were up regulated and 3729 genes (85%) were down regulated in malathion treated human lymphocytes. About 57 cancer associated genes related to the growth and differentiation of B and T cells, immunoglobulin production, haematopoiesis, tumor suppression, oncogenes and signal transduction pathways like MAPK and RAS were induced by malathion.

CONCLUSION

This study evidences the carcinogenic nature of malathion. Low concentration of this pesticide is not cytotoxic and induces differentially regulated genes in human lymphocytes, which are involved in the initiation, progression, and pathogenesis of cancer.

Upregulation of hsa_circ_0007874 suppresses the progression of ovarian cancer by regulating the miR-760/SOCS3 pathway

Ovarian cancer (OVA) is a fatal and common malignancy in women worldwide. Circular RNAs (circRNAs) consist of a family of circular endogenous RNAs generated by selective splicing, and they are involved in many diseases. Previous studies reported that hsa_circ_0007874 is aberrantly expressed in cancer and functions in tumorigenesis. While the hsa_circ_0007874 role in OVA is unclear. Here, we detected the hsa_circ_0007874 expression in OVA cell lines using Rt‐qPCR. Hsa_circ_0007874 subcellular localization was confirmed by fluorescence in situ hybridization. The relationship between hsa_circ_0007874, microRNAs (miRNAs), and relative protein levels was assessed using the luciferase reporter assays. Results verified that hsa_circ_0007874 is downregulated in OVA cell lines. hsa_circ_0007874 overexpression decreased the OVA cell migration and proliferation in vitro and in vivo. Bioinformatics and luciferase reporter assays confirmed that miR‐760 and SOCS3 are the downstream targets of hsa_circ_0007874. Downregulation of SOCS3 or miR‐760 overexpression restored the migration and proliferation ability of SKOV3 or A2780 cells overexpressing hsa_circ_0007874. Downregulation of SOCS3 restored the proliferation and migration in miR‐760 knockdown SKOV3 and A2780 cells. In summary, the data suggest that hsa_circ_0007874 acts as a tumor suppressor by regulating the miR‐760/SOCS3 axis, highlighting its potential as an effective therapeutic target for OVA.

Clinical implications of ALDH1A1 and ALDH1A3 mRNA expression in melanoma subtypes

Aldehyde dehydrogenase (ALDH) activity is not only a valuable marker for cancer cells with stem-like features, but also plays a vital role in drug resistance and disease progression in many tumors including melanoma. However, the precise role of ALDH activity in patient prognosis remains unclear. In this study, using the Cancer Genome Atlas (TCGA) RNA-sequencing expression data, we analyzed gene expression of ALDH isozymes in melanoma tumors to define the expression patterns and the prognostic and predictive values of these enzymes. We found that ALDH1A1 and ALDH1A3 had both higher and broader expression ranges in melanoma patients, and that ALDH1A3 expression correlated with better overall survival in metastatic melanoma. Further, stratification of the TCGA cohorts by the mutational subtypes of melanoma specifically revealed that expression of ALDH1A3 correlated with better prognosis in metastatic BRAF-mutant melanoma while expression of ALDH1A1 correlated with better prognosis in BRAF wild-type melanoma. Gene set enrichment analysis (GSEA) of these cohorts identified upregulation in oxidative phosphorylation, adipogenesis, and fatty acid metabolism signaling in ALDH1A^lo patients, suggesting BRAF/MEK inhibitor resistance in that subset of patients. On the other hand, GSEA of ALDH1A3^hi cohorts revealed upregulation in glycolysis, hypoxia and angiogenesis, suggesting BRAF/MEK inhibitor sensitivity in that subset of patients. Gene expression analysis using pre-treatment tumor samples supports high ALDH1A3 expression before BRAF/MEK inhibitor treatment as predictive of better treatment response in BRAF-mutant melanoma patients. Our study provides evidence that high ALDH1A3 mRNA expression is not only a prognostic marker but also a predictive marker for BRAF/MEK inhibitor treatment response in BRAF-mutant metastatic melanoma patients.

Control of Tyrosine Kinase Signalling by Small Adaptors in Colorectal Cancer

Tyrosine kinases (TKs) phosphorylate proteins on tyrosine residues as an intracellular signalling mechanism to coordinate intestinal epithelial cell communication and fate decision. Deregulation of their activity is ultimately connected with carcinogenesis. In colorectal cancer (CRC), it is still unclear how aberrant TK activities contribute to tumour formation because TK-encoding genes are not frequently mutated in this cancer. In vertebrates, several TKs are under the control of small adaptor proteins with potential important physiopathological roles. For instance, they can exert tumour suppressor functions in human cancer by targeting several components of the oncogenic TK signalling cascades. Here, we review how the Src-like adaptor protein (SLAP) and the suppressor of cytokine signalling (SOCS) adaptor proteins regulate the SRC and the Janus kinase (JAK) oncogenic pathways, respectively, and how their loss of function in the intestinal epithelium may influence tumour formation. We also discuss the potential therapeutic value of these adaptors in CRC.

[Role of cytokine signal suppressor 3 in the regulatory mechanism of colon cancer invasion and proliferation]

OBJECTIVE

To investigate the expression of cytokine signal suppressor 3 (SOCS3) in colon cancer tissue and the mechanism by which SOCS3 regulates the proliferation and invasion of colon cancer.

METHODS

We collected the specimens of tumor tissues and paired adjacent tissues from 80 patients with colon cancer undergoing radical resection in our hospital between July, 2014 and May, 2017, and the expression of SOCS3 in the tissue samples was analyzed using Western blotting. We also transfected colon cancer cell line SW480 with a SOCS3-overexpressing plasmid or a small interference RNA (siRNA) for SOCS3 knockdown, and the changes in the cell proliferation and invasion capacity were evaluated using CCK-8 assay and Transwell assay, respectively. The effect of demethylation and IL-6 treatment on SOCS3 expression and the proliferation and invasion of SW480 cells were observed.

RESULTS

Colon cancer tissues showed a lowered expression of SOCS3 compared with the adjacent tissues. Over-expression of SOCS3 significantly inhibited while SOCS3 knockdown obviously promoted the proliferation and invasion of SW480 cells in vitro. Demethylation treatment up-regulated SOCS3 expression and inhibited the proliferation and invasion capacity of SW480 cells; IL-6 treatment of the cells caused the reverse changes.

CONCLUSIONS

SOCS3 participates in the development and progression of colon cancer and serves as a potential target for colon cancer treatment. In patients with colon cancer, the low expression of SOCS3 possibly as a result of methylation may promote the proliferation and invasion of the cancer cells.

Crizotinib induces apoptosis of lung cancer cells through JAK-STAT pathway

Effect of crizotinib on apoptosis of lung cancer cells was investigated. Human non-small cell lung adenocarcinoma H2228 cells were cultured in the presence of 0, 20, 40, 80, 160 and 320 nmol/l of crizotinib for 3 days, respectively. The inhibition rate of cell proliferation was measured by MTT assay, and half maximal inhibitory concentration (IC₅₀) was calculated. Cell apoptosis was detected by flow cytometry. Transwell assay was performed to detect cell migration. Expression of Janus protein tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) proteins was detected by western blot analysis. Crizotinib significantly inhibited the proliferation of human lung cancer H2228 cells, and the inhibitory effect was enhanced with the increase of the concentration of crizotinib (p<0.01). The IC₅₀ value was 311.26 nnol/l. According to IC₅₀ value, concentration of crizotinib at 300 nmol/l was selected for the study. It was found that crizotinib at 300 nmol/l significantly promoted cell apoptosis (p<0.01) and inhibited cell migration (p<0.01). Compared with pretreatment levels, crizotinib downregulated the expression of JAK and STAT (p<0.01) on the 1st day of treatment, but with the prolongation of time, no further significant difference was observed on the 1st, 2nd or 3rd day in the level of JAK protein (p=0.47); there were no statistically significant differences in the level of STAT protein (p=0.91). Crizotinib can inhibit the migration and promote cell apoptosis of human lung cancer cell line H2228 by regulating the expression of JAK and STAT proteins in JAK-STAT signaling pathway.

Systematic Analysis of Transcriptomic Profile of Renal Cell Carcinoma under Long-Term Hypoxia Using Next-Generation Sequencing and Bioinformatics

Patients with clear cell renal cell carcinoma (ccRCC) are often diagnosed with both von Hippel-Lindau (VHL) mutations and the constitutive activation of hypoxia-inducible factor-dependent signaling. In this study, we investigated the effects of long-term hypoxia in 786-O, a VHL-defective renal cell carcinoma cell line, to identify potential genes and microRNAs associated with tumor malignancy. The transcriptomic profiles of 786-O under normoxia, short-term hypoxia and long-term hypoxia were analyzed using next-generation sequencing. The results showed that long-term hypoxia promoted the ability of colony formation and transwell migration compared to normoxia. In addition, the differentially expressed genes induced by long-term hypoxia were involved in various biological processes including cell proliferation, the tumor necrosis factor signaling pathway, basal cell carcinoma and cancer pathways. The upregulated (L1CAM and FBN1) and downregulated (AUTS2, MAPT, AGT and USH1C) genes in 786-O under long-term hypoxia were also observed in clinical ccRCC samples along with malignant grade. The expressions of these genes were significantly correlated with survival outcomes in patients with renal cancer. We also found that long-term hypoxia in 786-O resulted in decreased expressions of hsa-mir-100 and hsa-mir-378 and this effect was also observed in samples of metastatic ccRCC compared to samples of non-metastatic ccRCC. These findings may provide a new direction for the study of potential molecular mechanisms associated with the progression of ccRCC.