Thioredoxin-1 promotes colorectal cancer invasion and metastasis through crosstalk with S100P

S100P facilitates LUAD progression via PKA/c-Jun-mediated tumor-associated macrophage recruitment and polarization

S100P, a member of the S100 calcium-binding protein family, is closely associated with abnormal proliferation, invasion, and metastasis of various cancers. However, its role in the lung adenocarcinoma (LUAD) tumor microenvironment (TME) remains unclear. In this study, we observed specific expression of S100P on tumor cells in LUAD patients through tissue immunofluorescence analysis. Furthermore, this expression was strongly correlated with the recruitment and polarization of tumor-associated macrophages (TAMs). Bioinformatics analysis revealed that high S100P expression is associated with poorer overall survival in LUAD patients. Subsequently, a subcutaneous mouse model demonstrated that S100P promotes recruitment and polarization of TAMs towards the M2 type. Finally, in vitro studies on LUAD cells revealed that S100P enhances the secretion of chemokines and polarizing factors by activating the PKA/c-Jun pathway, which is implicated in TAM recruitment and polarization towards the M2 phenotype. Moreover, inhibition of c-Jun expression impedes the ability of TAMs to infiltrate and polarize towards the M2 phenotype. In conclusion, our study demonstrates that S100P facilitates LUAD cells growth by recruiting M2 TAMs through PKA/c-Jun signaling, resulting in the production of various cytokines. Considering these findings, S100P holds promise as an important diagnostic marker and potential therapeutic target for LUAD.

Thioredoxin system in colorectal cancer: Its role in carcinogenesis, disease progression, and response to treatment

The thioredoxin system is essential for many physiological processes, including the maintenance of redox signalling pathways. Alterations in the activity, expression and interactions with other signalling pathways can lead to protective or pathophysiological responses. Thioredoxin and thioredoxin reductase, the two main components of this system, are often overexpressed in cancer, including colorectal cancer. This overexpression is often linked with tumour progression and poor outcomes. This review discusses the role of the Trx system in driving colorectal carcinogenesis and disease progression, as well as the challenges of targeting this system. Additionally, the recent advancements in the development of novel and effective thioredoxin inhibitors for colorectal cancer are also explored.

The Long Noncoding RNA Gall Bladder Cancer-Associated Suppressor of Pyruvate Carboxylase Inhibits the Proliferation, Migration, and Invasion of Colorectal Cancer Cells and Induces Their Apoptosis

This study aimed to determine the role of the long noncoding RNA (lncRNA) gall bladder cancer-associated suppressor of pyruvate carboxylase (SOD2-1) in the progression of colorectal cancer (CRC). A total of 23 pairs of specimens, including CRC tissues and adjacent normal tissues, were collected, and the expression of lncRNA SOD2-1 (lnc-SOD2-1) was measured. lnc-SOD2-1 function was examined using HCT15 and HCT116 cells. A lnc-SOD2-1 overexpression vector was designed and transfected into both cell lines. MTS and colony formation assays were used to determine cell viability. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assays were performed to measure apoptosis. Cell migration and invasion were evaluated using the Transwell assay. Migration and invasion markers were validated using quantitative reverse transcription-polymerase chain reaction and western blot analysis. The results indicated that the expression of lnc-SOD2-1 was downregulated in CRC tissues. lnc-SOD2-1 overexpression evidently decreased cell viability and led to the formation of fewer cell colonies. lnc-SOD2-1 overexpression induced ~ twofold higher apoptosis than the control group. lnc-SOD2-1 overexpression reduced the proportion of migratory and invasive cells to 50% and 75% of the control group, respectively. lnc-SOD2-1 overexpression significantly decreased the expression of matrix metalloproteinase-2 and -9. In conclusion, lnc-SOD2-1 may act as a tumor suppressor that inhibits the proliferation, migration, and invasion of CRC cells and induces their apoptosis.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

Inhibition of thioredoxin-1 enhances the toxicity of glycolysis inhibitor 2-deoxyglucose by downregulating SLC1A5 expression in colorectal cancer cells

BACKGROUND

Targeting glycolysis in cancer is an attractive approach for therapeutic intervention. 2-Deoxyglucose (2DG) is a synthetic glucose analog that inhibits glycolysis. However, its efficacy is limited by the systemic toxicity at high doses. Understanding the mechanism of 2DG resistance is important for further use of this drug in cancer treatment.

METHODS

The expression of thioredoxin-1 (Trx-1) in colorectal cancer (CRC) cells treated with 2DG was detected by Western blotting. The effect of Trx-1 on the cytotoxicity of 2DG in CRC cells was examined in vitro and in vivo. The molecular mechanism involved in Trx-1-mediated activation of the SLC1A5 gene promoter activity was elucidated using in vitro models.

RESULTS

Inhibition glycolysis with 2DG increased the expression of Trx-1 in CRC cells. Overexpression of Trx-1 decreased the cytotoxicity of 2DG, whereas knockdown of Trx-1 by shRNA significantly increased the cytotoxicity of 2DG in CRC cells. The Trx-1 inhibitor PX-12 increased the cytotoxicity of 2DG on CRC cells both in vitro and in vivo. In addition, Trx-1 promoted SLC1A5 expression by increasing the promoter activity of the SLC1A5 gene by binding to SP1. We also found that the SLC1A5 expression was upregulated in CRC tissues, and inhibition of SLC1A5 significantly enhanced the inhibitory effect of 2DG on the growth of CRC cells in vitro and in vivo. Overexpression of SLC1A5 reduced the cytotoxicity of 2DG in combination with PX-12 treatment in CRC cells.

CONCLUSION

Our results demonstrate a novel adaptive mechanism of glycolytic inhibition in which Trx-1 increases GSH levels by regulating SLC1A5 to rescue cytotoxicity induced by 2DG in CRC cells. Inhibition of glycolysis in combination with inhibition of Trx-1 or SLC1A5 may be a promising strategy for the treatment of CRC.

Discovery of novel organoarsenicals as robust thioredoxin reductase inhibitors for oxidative stress mediated cancer therapy

Targeting overexpressed thioredoxin reductase (TrxR) in cancer cells to induce oxidative stress has been proved to be an effective strategy for cancer therapy. However, the treatment was hindered by the low efficiency and frequent administration of TrxR inhibitors, and hence more potent TrxR inhibitors were urgently needed. Herein, we designed and synthesized a series of TrxR inhibitors based on arsenicals. Among these, compound 1d inhibited the proliferation of a variety of cancer cells at low micromolar concentrations and exhibited low toxicity to normal cells. Importantly, compound 1d induced the accumulation of reactive oxygen species (ROS) by inhibiting the TrxR activity, further causing the collapse of the redox system, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and DNA damage, followed by oxidative stress-induced cell apoptosis. In vivo data showed that, compared with the clinical TrxR inhibitor auranofin (AUR), compound 1d could more effectively eliminate tumors by 90 % at a dose of 1.5 mg/kg without any obvious side effects. These results indicated that compound 1d was a potent TrxR inhibitor against cancer.

The role of TXNIP in cancer: a fine balance between redox, metabolic, and immunological tumor control

Thioredoxin-interacting protein (TXNIP) is commonly considered a master regulator of cellular oxidation, regulating the expression and function of Thioredoxin (Trx). Recent work has identified that TXNIP has a far wider range of additional roles: from regulating glucose and lipid metabolism, to cell cycle arrest and inflammation. Its expression is increased by stressors commonly found in neoplastic cells and the wider tumor microenvironment (TME), and, as such, TXNIP has been extensively studied in cancers. In this review, we evaluate the current literature regarding the regulation and the function of TXNIP, highlighting its emerging role in modulating signaling between different cell types within the TME. We then assess current and future translational opportunities and the associated challenges in this area. An improved understanding of the functions and mechanisms of TXNIP in cancers may enhance its suitability as a therapeutic target.

Gut microbiota-derived short-chain fatty acids regulate gastrointestinal tumor immunity: a novel therapeutic strategy?

Tumor immune microenvironment (TIME), a tumor-derived immune component, is proven to be closely related to the development, metastasis, and recurrence of tumors. Gut microbiota and its fermented-metabolites short-chain fatty acids (SCFAs) play a critical role in maintaining the immune homeostasis of gastrointestinal tumors. Consisting mainly of acetate, propionate, and butyrate, SCFAs can interact with G protein-coupled receptors 43 of T helper 1 cell or restrain histone deacetylases (HDACs) of cytotoxic T lymphocytes to exert immunotherapy effects. Studies have shed light on SCFAs can mediate the differentiation and function of regulatory T cells, as well as cytokine production in TIME. Additionally, SCFAs can alter epigenetic modification of CD8⁺ T cells by inhibiting HDACs to participate in the immune response process. In gastrointestinal tumors, the abundance of SCFAs and their producing bacteria is significantly reduced. Direct supplementation of dietary fiber and probiotics, or fecal microbiota transplantation to change the structure of gut microbiota can both increase the level of SCFAs and inhibit tumor development. The mechanism by which SCFAs modulate the progression of gastrointestinal tumors has been elucidated in this review, aiming to provide prospects for the development of novel immunotherapeutic strategies.

Thioredoxin-1 regulates self-renewal and differentiation of murine hematopoietic stem cells through p53 tumor suppressor

BACKGROUND

Thioredoxin-1 (TXN1) is one of the major cellular antioxidants in mammals and is involved in a wide range of physiological cellular responses. However, little is known about the roles and the underlying molecular mechanisms of TXN1 in the regulation of hematopoietic stem/progenitor cells (HSPCs).

METHODS

TXN1 conditional knockout mice (ROSA-CreER-TXN1fl/fl) and TXN1fl/fl control mice were used. The mice were treated with tamoxifen and the number and biological functions of HSPCs were measured by flow cytometry, PCR and western blot. Limiting dilution competitive transplantation with sorted HSCs and serial transplantations were performed to assess the effects of TXN1 knockout on HSC self-renewal and long-term reconstitutional capacity. RNA sequencing (RNA-seq) was performed to investigate the downstream molecular pathways of TXN1 deletion in murine HSPCs. CRISPR/Cas9 knockout experiments were performed in vitro in EML murine hematopoietic stem/progenitor cell line to investigate the effects of TXN1 and/or TP53 deletion on cell survival, senescence and colony forming units. TP53 protein degradation assay, CHiP PCR and PGL3 firefly/renilla reporter assay were performed. The effects of TXN1 on various molecular pathways relevant to HSC radiation protection were examined in vitro and in vivo.

RESULTS

TXN1-TP53 tumor suppressor axis regulates HSPC biological fitness. Deletion of TXN1 in HSPCs using in vivo and in vitro models activates TP53 signaling pathway, and attenuates HSPC capacity to reconstitute hematopoiesis. Furthermore, we found that knocking out of TXN1 renders HSPCs more sensitive to radiation and treatment with recombinant TXN1 promotes the proliferation and expansion of HSPCs.

CONCLUSIONS

Our findings suggest that TXN1-TP53 axis acts as a regulatory mechanism in HSPC biological functions. Additionally, our study demonstrates the clinical potential of TXN1 for enhancing hematopoietic recovery in hematopoietic stem cell transplant and protecting HSPCs from radiation injury.

A novel prognostic model based on urea cycle-related gene signature for colorectal cancer

Background

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the world. This study aimed to develop a urea cycle (UC)-related gene signature that provides a theoretical foundation for the prognosis and treatment of patients with CRC.

Methods

Differentially expressed UC-related genes in CRC were confirmed using differential analysis and Venn diagrams. Univariate Cox and least absolute shrinkage and selection operator regression analyses were performed to identify UC-related prognostic genes. A UC-related signature was created and confirmed using distinct datasets. Independent prognostic predictors were authenticated using Cox analysis. The Cell-type Identification by Estimating Relative Subsets of RNA Transcripts algorithm and Spearman method were applied to probe the linkage between UC-related prognostic genes and tumor immune-infiltrating cells. The Human Protein Atlas database was used to determine the protein expression levels of prognostic genes in CRC and normal tissues. Verification of the expression levels of UC-related prognostic genes in clinical tissue samples was performed using real-time quantitative polymerase chain reaction (qPCR).

Results

A total of 49 DEUCRGs in CRC were mined. Eight prognostic genes (TIMP1, FABP4, MMP3, MMP1, CD177, CA2, S100P, and SPP1) were identified to construct a UC-related gene signature. The signature was then affirmed using an external validation set. The risk score was demonstrated to be a credible independent prognostic predictor using Cox regression analysis. Functional enrichment analysis revealed that focal adhesion, ECM-receptor interaction, IL-17 signaling pathway, and nitrogen metabolism were associated with the UC-related gene signature. Immune infiltration and correlation analyses revealed a significant correlation between UC-related prognostic genes and differential immune cells between the two risk subgroups. Finally, the qPCR results of clinical samples further confirmed the results of the public database.

Conclusion

Taken together, this study authenticated UC-related prognostic genes and developed a gene signature for the prognosis of CRC, which will be of great significance in the identification of prognostic molecular biomarkers, clinical prognosis prediction, and development of treatment strategies for patients with CRC.

The adipocyte-enriched secretory protein tetranectin exacerbates type 2 diabetes by inhibiting insulin secretion from β cells

Pancreatic β cell failure is a hallmark of diabetes. However, the causes of β cell failure remain incomplete. Here, we report the identification of tetranectin (TN), an adipose tissue-enriched secretory molecule, as a negative regulator of insulin secretion in β cells in diabetes. TN expression is stimulated by high glucose in adipocytes via the p38 MAPK/TXNIP/thioredoxin/OCT4 signaling pathway, and elevated serum TN levels are associated with diabetes. TN treatment greatly exacerbates hyperglycemia in mice and suppresses glucose-stimulated insulin secretion in islets. Conversely, knockout of TN or neutralization of TN function notably improves insulin secretion and glucose tolerance in high-fat diet-fed mice. Mechanistically, TN binds with high selectivity to β cells and inhibits insulin secretion by blocking L-type Ca²⁺ channels. Our study uncovers an adipocyte-β cell cross-talk that contributes to β cell dysfunction in diabetes and suggests that neutralization of TN levels may provide a new treatment strategy for type 2 diabetes.

Aspirin promotes RSL3-induced ferroptosis by suppressing mTOR/SREBP-1/SCD1-mediated lipogenesis in PIK3CA-mutant colorectal cancer

Ferroptosis, a new form of regulated cell death triggered by the iron-dependent peroxidation of phospholipids, is associated with cellular metabolism, redox homeostasis, and various signaling pathways related to cancer. Aspirin is a widely used non-steroidal anti-inflammatory drug (NSAID) and has been reported to show therapeutic benefit in cancers harboring oncogenic PIK3CA, which encodes the catalytic p110α subunit of phosphoinositide 3-kinase (PI3K). In this study, we found that aspirin sensitized cancer cells harboring oncogenic activation of PIK3CA to ferroptosis induction. Mechanistically, aspirin inhibited protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling, suppressed downstream sterol regulatory element-binding protein 1 (SREBP-1) expression, and attenuated stearoyl-CoA desaturase-1 (SCD1)-mediated lipogenesis of monounsaturated fatty acids, thus promoting RSL3-induced ferroptosis in colorectal cancer (CRC) cells. Moreover, genetic ablation of SREBP-1 or SCD1 conferred cancer cells greater sensitivity to ferroptosis induction. Conversely, ectopic expression of SREBP-1 or SCD1 restored ferroptosis resistance in CRC cells and abolished the effect of aspirin on RSL3-induced cytotoxicity. Additionally, the synergistic effects of aspirin and RSL3 were confirmed in a xenograft mouse model. The combined use of aspirin and RSL3 resulted in significant tumor suppression. Our work demonstrated that aspirin enhanced the cytotoxic effect of RSL3 in PIK3CA-mutant cancers, and the combination of aspirin and ferroptosis inducer displayed promising therapeutic effects in cancer treatment.

Thioredoxin 1 supports colorectal cancer cell survival and promotes migration and invasion under glucose deprivation through interaction with G6PD

Overcoming energy stress is a critical step for cells in solid tumors. Under this stress microenvironment, cancer cells significantly alter their energy metabolism to maintain cell survival and even metastasis. Our previous studies have shown that thioredoxin-1 (Trx-1) expression is increased in colorectal cancer (CRC) and promotes cell proliferation. However, the exact role and mechanism of how Trx-1 is involved in energy stress are still unknown. Here, we observed that glucose deprivation of CRC cells led to cell death and promoted the migration and invasion, accompanied by upregulation of Trx-1. Increased Trx-1 supported CRC cell survival under glucose deprivation. Whereas knockdown of Trx-1 sensitized CRC cells to glucose deprivation-induced cell death and reversed glucose deprivation-induced migration, invasion, and epithelial-mesenchymal transition (EMT). Furthermore, we identified glucose-6-phosphate dehydrogenase (G6PD) interacting with Trx-1 by HuPortTM human protein chip, co-IP and co-localization. Trx-1 promoted G6PD protein expression and activity under glucose deprivation, thereby increasing nicotinamide adenine dinucleotide phosphate (NADPH) generation. Moreover, G6PD knockdown sensitized CRC cells to glucose deprivation-induced cell death and suppressed glucose deprivation-induced migration, invasion, and EMT. Inhibition of Trx-1 and G6PD, together with inhibition of glycolysis using 2-deoxy-D-glucose (2DG), resulted in significant anti-tumor effects in CRC xenografts in vivo. These findings demonstrate a novel mechanism and may represent a new effective therapeutic regimen for CRC.

Calcium-binding protein S100P is a new target gene of MACC1, drives colorectal cancer metastasis and serves as a prognostic biomarker

Background

The metastasis inducing gene MACC1 is a prognostic and predictive biomarker for metastasis in several cancers. Its mechanism of inducing metastasis includes the transcriptional control of other cancer-related target genes. Here, we investigate the interplay with the metastasis driver S100P in CRC progression.

Methods

MACC1-dependent S100P expression was analysed by qRT-PCR. The binding of MACC1 to the S100P promoter was determined by ChIP. Alterations in cell proliferation and motility were determined by functional in vitro assays. In vivo metastasis after intrasplenic transplantation was assessed by bioluminescence imaging and evaluation of tumour growth and liver metastasis. The prognostic value of S100P was determined in CRC patients by ROC-based Kaplan–Meier analyses.

Results

Expression of S100P and MACC1 correlated positively in CRC cells and colorectal tumours. MACC1 was found binding to the S100P promoter and induces its expression. The overexpression of S100P increased proliferation, migration and invasion in vitro and significantly induced liver metastasis in vivo. S100P expression was significantly elevated in metachronously metastasising CRC and was associated with shorter metastasis-free survival.

Conclusions

We identified S100P as a transcriptional target gene of MACC1. Expression of S100P increases the metastatic potential of CRC cells in vitro and in vivo, and serves as a prognostic biomarker for metastasis-free survival of CRC patients, emphasising novel therapeutic interventions targeting S100P.

DNA comethylation analysis reveals a functional association between BRCA1 and sperm DNA fragmentation

OBJECTIVES

To identify the DNA comethylation patterns associated with sperm DNA fragmentation (SDF) and to explore the potential associations of hub genes with SDF.

DESIGN

Prospective study.

SETTING

University-affiliated reproductive medicine center.

PATIENT(S)

A total of 300 male patients consulting for couple infertility were recruited from the First Affiliated Hospital of Wenzhou Medical University.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Comethylation network analysis based on the genome-wide methylation profile of spermatozoal DNA from 20 men was performed to identify hub modules and genes involved in SDF. Human spermatozoa were used for targeted bisulfite amplicon sequencing (267 men) or droplet digital polymerase chain reaction (45 men). The potential role of Brca1 in DNA damage was explored in mouse GC2 spermatocyte cells. Oxidative damage to spermatocytes was modeled by incubating GC2 cells with H₂O₂ (25 mM) for 90 minutes.

RESULT(S)

BRCA1 was identified as a hub gene in SDF. Promoter hypermethylation of BRCA1 was observed in those samples with a high DNA fragmentation index (DFI) compared to those with a low DFI. Concomitantly, BRCA1 mRNA expression was lower in samples with a high DFI than with a low DFI. In the GC2 cell model, Brca1 knockdown reduced cell proliferation and increased sensitivity to oxidative stress. Moreover, it increased double-strand breaks and decreased the protein levels of the DNA repair genes MRE11 and RAD51.

CONCLUSION(S)

A prominent cluster of comethylated patterns associated with SDF was identified. BRCA1 may be the hub gene involved in sperm DNA damage.

Thiol-Based Antioxidants and the Epithelial/Mesenchymal Transition in Cancer

Significance: The epithelial/mesenchymal transition (EMT) is commonly associated with tumor metastasis. Oxidative and nitrosative stress is maintained in cancer cells and is involved in the EMT. Cancer cells are endowed with high levels of enzymatic and nonenzymatic antioxidants, which counteract the effects of oxidative and nitrosative stress. Thiol-based antioxidant systems such as the thioredoxin/thioredoxin reductase (Trx/TrxR) and glutathione/glutaredoxin (GSH/Grx) are continually active in cancer cells, while the thioredoxin-interacting protein (Txnip), the negative regulator of the Trx/TrxR system, is downregulated. Recent Advances: Trx/TrxR and GSH/Grx systems play a major role in maintaining EMT signaling and cancer cell progression. Critical Issues: Enhanced stress conditions stimulated in cancer cells inhibit EMT signaling. The elevated expression levels of the Trx/TrxR and GSH/Grx systems in these cells provide the antioxidant protection necessary to guarantee the occurrence of the EMT. Future Directions: Elevation of the intracellular reactive oxygen species and nitric oxide concentrations in cancer cells has been viewed as a promising strategy for elimination of these cells. The development of inhibitors of GSH synthesis and of the Trx/TrxR system together with genetic-based strategies to enhance Txnip levels may provide the necessary means to achieve this goal. Antioxid. Redox Signal. 36, 1037-1050.

The blood level of thioredoxin 1 as a supporting biomarker in the detection of breast cancer

BACKGROUND

There is a long-time unmet need for a means to detect breast cancer (BC) using blood. Although mammography is accepted as the gold standard for screening, a blood-based diagnostic can complement mammography and assist in the accurate detection of BC in the diagnostic process period of early diagnosis. We have previously reported the possible use of thioredoxin 1 (Trx1) in serum as a novel means to detect BC. In the present study, we validated the clinical utility of Trx1 to identify BC by testing sera from biopsy-confirmed cancer patients and women without cancer.

METHODS

We have generated monoclonal antibodies against Trx1 and developed an ELISA kit that can quantitate Trx1 in sera. The level of Trx1 was determined in each serum from women without cancer (n = 114), as well as in serum from patients with BC (n = 106) and other types of cancers (n = 74), including cervical, lung, stomach, colorectal, and thyroid cancer. The sera from BC patients were collected and classified by the subjects' age and cancer stage. In addition to the Trx1 levels of BC patients, several pathological and molecular aspects of BC were analyzed. Test results were retrospectively compared to those from mammography. Each test was duplicated, and test results were analyzed by ROC analysis, one-way ANOVA tests, and unpaired t-tests.

RESULTS

The mean level of Trx1 from women without cancer was 5.45 ± 4.16 (±SD) ng/ml, that of the other malignant cancer patient group was 2.70 ± 2.01 ng/ml, and that from the BC group was 21.96 ± 6.79 ng/ml. The difference among these values was large enough to distinguish BC sera from non-BC control sera with a sensitivity of 97.17% and specificity of 94.15% (AUC 0.990, p < 0.0001). Most Trx1 levels from BC patients' sera were higher than the cut-off value of 11.4 ng/ml regardless of age, stage, histological grade, type, and specific receptors' expression profile of BC. The level of Trx1 could rescue women from most cases of misread or incomplete mammography diagnoses.

CONCLUSION

These results indicated that the blood level of Trx1 could be an effective and accurate means to assist the detection of BC during the early diagnosis period.

Cloning and characterization of Thioredoxin 1 from the Cnidarian Hydra

Thioredoxins, small disulphide-containing redox proteins, play an important role in the regulation of cellular thiol redox balance through their disulfide reductase activity. In this study, we have identified, cloned, purified and characterized thioredoxin 1 (HvTrx1) from the Cnidarian Hydra vulgaris Ind-Pune. Bioinformatics analysis revealed that HvTrx1 contains an evolutionarily conserved catalytic active site CGPC and shows a closer phylogenetic relationship with vertebrate Trx1. Optimum pH and temperature for enzyme activity of purified HvTrx1 was found to be pH 7.0 and 25 °C respectively. Enzyme activity decreased significantly at acidic or alkaline pH as well as at higher temperatures. HvTrx1 was found to be expressed ubiquitously in whole mount in situ hybridization. Treatment of Hydra with hydrogen peroxide (H2O2), a highly reactive oxidizing agent, led to a significant increase in gene expression and enzyme activity of Trx1. Further experiments using PX12, an inhibitor of Trx1, indicated that Trx1 plays an important role in regeneration in Hydra. Finally, by using growth assay in E. coli and wound healing assay in human colon cancer cells, we demonstrate that HvTrx1 is functionally active in both prokaryotic and eukaryotic heterologous systems.

Cancer-associated fibroblasts-derived exosomes upregulate microRNA-135b-5p to promote colorectal cancer cell growth and angiogenesis by inhibiting thioredoxin-interacting protein

OBJECTIVE

The role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP).

METHODS

CRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed.

RESULTS

MiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p, CONCLUSION: CAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.

Impact of Andrographolide and Melatonin Combinatorial Drug Therapy on Metastatic Colon Cancer Cells and Organoids

Background:

The death rate (the number of deaths per 100 000 people per year) of colorectal cancer (CRC) has been dropping since 1980 due to increased screening, lifestyle-related risk factors, and improved treatment options; however, CRC is the third leading cause of cancer-related deaths in men and women in the United States. Therefore, successful therapy for CRC is an unmet clinical need. This study aimed to investigate the impacts of andrographolide (AGP) and melatonin (MLT) on CRC and the underlying mechanism.

Methods:

To investigate AGP and MLT anticancer effects, a series of metastatic colon cancer cell lines (T84, Colo 205, HT-29, and DLD-1) were selected. In addition, a metastatic patient-derived organoid model (PDOD) was used to monitor the anticancer effects of AGP and MLT. A series of bioassays including 3D organoid cell culture, MTT, colony formation, western blotting, immunofluorescence, and quantitative polymerase chain reaction (qPCR) were performed.

Results:

The dual therapy significantly promotes CRC cell death, as compared with the normal cells. It also limits CRC colony formation and disrupts the PDOD membrane integrity along with decreased Ki-67 expression. A significantly higher cleaved caspase-3 and the endoplasmic reticulum (ER) stress proteins, IRE-1 and ATF-6 expression, by 48 hours were found. This combinatorial treatment increased reactive oxygen species (ROS) levels. Apoptosis signaling molecules BAX, XBP-1, and CHOP were significantly increased as determined by qPCR.

Conclusions:

These findings indicated that AGP and MLT associated ER stress-mediated apoptotic metastatic colorectal cancer (mCRC) cell death through the IRE-1/XBP-1/CHOP signaling pathway. This novel combination could be a potential therapeutic strategy for mCRC cells.

The KLF6 Super Enhancer Modulates Cell Proliferation via MiR-1301 in Human Hepatoma Cells

BACKGROUND

Recent studies have attempted to elucidate the function of super enhancers by means of microRNAs. Although the functional outcomes of miR-1301 have become clearer, the pathways that regulate the expressions of miR-1301 remain unclear.

OBJECTIVE

The objective of this paper was to consider the pathway regulating expression of miR- 1301 and miR-1301 signaling pathways with the inhibition of cell proliferation.

METHODS

In this study, we prepared the cell clones that the KLF6 super enhancer was deleted by means of the CRISPR/Cas9 system-mediated genetic engineering. Changes in miR-1301 expression after the deletion of the KLF6 super enhancer were evaluated by RT-PCR analysis, and the signal pathway of miR-1301 with inhibition of the cell proliferation was examined using RNA interference technology.

RESULTS

The results showed that miR-1301 expression was significantly increased after the deletion of the KLF6 super enhancer. Over-expression of miR-1301 induced by deletion of the KLF6 super enhancer also regulated the expression of p21 and p53 in human hepatoma cells. functional modeling of findings using siRNA specific to miR-1301 showed that expression level changes had direct biological effects on cellular proliferation in Human hepatoma cells. Furthermore, cellular proliferation assay was shown to be directly associated with miR-1301 levels.

CONCLUSION

As a result, it was demonstrated that the over-expression of miR-1301 induced by the disruption of the KLF6 super enhancer leads to a significant inhibition of proliferation in HepG2 cells. Moreover, it was demonstrated that the KLF6 super enhancer regulates the cell-proliferative effects which are mediated, at least in part, by the induction of p21and p53 in a p53-dependent manner. Our results provide the functional significance of miR-1301 in understanding the transcriptional regulation mechanism of the KLF6 super enhancer.

The deficiency of FKBP-5 inhibited hepatocellular progression by increasing the infiltration of distinct immune cells and inhibiting obesity-associated gut microbial metabolite

Background

Gut microbiota has a number of essential roles in nutrition metabolism and immune homeostasis, and is closely related to hepatocellular progression. In recent years, studies have also shown that FK506 binding protein 5 (FKBP-5) plays a crucial role in immune regulation. However, it is not yet clear whether FKBP-5 promotes the development of hepatocellular carcinoma (HCC) by affecting immune function and gut microbiota.

Methods

FKBP-5 expression was verified by immunochemistry and western blot and reverse transcription polymerase chain reaction (RT-qPCR) assays. After treatment in WT and FKBP-5^-/- mice, the histological characteristic of mice liver tissue was assessed by H&E staining, and hepatic leukocytes and hepatic NKT cells were identified by flow cytometer. Meanwhile, primary bile acids (BAs), secondary BAs, serum total cholesterol, and the weight of abdomen adipose tissues were examined, and the gut microbiota was evaluated by 16S ribosomal ribonucleic acid (rRNA) sequencing.

Results

We discovered that FKBP-5 was highly expressed in HCC tissues. Meanwhile, FKBP-5 deletion inhibited tumor progression by increasing CD⁸⁺ T, CD⁴⁺ T, NKT and CD⁴⁺NKT cells in mice after diethylnitrosamine (DEN) injection. Besides, we proved that FKBP-5 deletion generated rapid and significant reductions in the intestinal BAs, the weight of abdomen adipose tissues and the serum total cholesterol. FKBP-5 deletion also led to a change in the composition of gut microbiota, suggesting that BAs are the main dietary factor regulating gut microbiota, which could be affected by FKBP-5 deletion. Further, we uncovered that anti-CD4 and anti-CD8 treatments facilitated hepatocellular progression by modulating gut microbiota composition in FKBP-5^-/- mice.

Conclusions

Therefore, we demonstrated that FKBP-5 deletion inhibited hepatocellular progression by modulating immune response and gut microbiome-mediated BAs metabolism.

Synthesis and biological evaluation of disulfides as anticancer agents with thioredoxin inhibition

Altered redox homeostasis as a hallmark of cancer cells is exploited by cancer cells for growth and survival. The thioredoxin (Trx), an important regulator in maintaining the intracellular redox homeostasis, is cumulatively recognized as a promising target for the development of anticancer drugs. Herein, we synthesized 72 disulfides and evaluated theirinhibition for Trx and antitumor activity. First, we established an efficient and fast method to screen Trx inhibitors by using the probe NBL-SS that was developed by our group to detect Trx function in living cells. After an initial screening of the Trx inhibitory activity of these compounds, 8 compounds showed significant inhibition activity against Trx. We then evaluated the cytotoxicity of these 8 disulfides, compounds 68 and 69 displayed high cytotoxicity to HeLa cells, but less sensitive to normal cell lines. Next, we performed kinetic studies of both two disulfides, 68 had faster inhibition of Trx than 69. Further studies revealed that 68 led to the accumulation of reactive oxygen species and eventually induced apoptosis of Hela cells via inhibiting Trx. The establishment of a method for screening Trx inhibitors and the discovery of 68 with remarkable Trx inhibition provide support for the development of anticancer candidates with Trx inhibition.

The role of TXNL1 in disease: treatment strategies for cancer and diseases with oxidative stress

Thioredoxin-like protein-1 (TXNL1; also known as thioredoxin-related 32 kDa protein, TRP32) is a thioredoxin involved in the regulation of oxidative stress, which protects cells from damage through redox balance. Studies have shown that TXNL1 has a variety of functions, including cell signal transduction, cell cycle regulation, protein synthesis, modification and degradation, vesicle transport, transcriptional regulation, cell apoptosis, virus replication and oxidative stress regulation, etc., and plays an important role in the occurrence and development of human diseases. Therefore, TXNL1 has a strong correlation with the treatment of cancer and oxidative stress diseases. In this paper, the basic structure, function and potential application value of TXNL1 in diseases are reviewed, so as to open up new targets for the treatment of cancer and oxidative stress-related diseases.

High nuclear expression of APE1 correlates with unfavorable prognosis and promotes tumor growth in hepatocellular carcinoma

APE1 is a multifunctional protein that plays important roles in cancer development. However, the association between APE1 expression and the clinicopathological parameters of HCC patients has not been fully characterized. In this study, bioinformatics analysis of APE1 was performed in several databases, including the TCGA, GeneCard, Human Protein Atlas and Ualcan databases. The relationship between APE1 mRNA expression and several attributes of liver cancer patients in TCGA was investigated. Then, the protein expression of APE1 was detected by IHC analysis in 95 HCC samples and the association between APE1 expression and the clinicopathological parameters of HCC patients was explored. GSEA-KEGG analysis was performed to predict the potential signaling pathways that associated with APE1 expression. Then the siRNA-mediated knockdown model of APE1 was constructed in HCC cell line to further detect the detailed function of APE1 in HCC development in vitro and in vivo. The results of the bioinformatics analysis showed that APE1 expression was primarily located in the cell nucleus. APE1 mRNA expression was substantially correlated with pathological grade and T status in TCGA database. Elevated APE1 expression was observed in HCC samples and was associated with unfavorable survival time in liver cancer patients. IHC data demonstrated that the nuclear expression of APE1 in HCC tissues was significantly higher than that in noncancerous tissues. The expression level of the APE1 protein in HCC was strongly associated with tumor diameter and overall survival. Survival analysis indicated that APE1 nuclear expression is an independent prognostic marker for the overall survival of HCC patients. GSEA-KEGG results confirmed that APE1 associated with the base excision repair signaling pathway. The data of phenotypic experiments indicated that APE1 remarkably promoted tumor growth both in HCC cells and xenografts. The findings firstly imply that nuclear expression of APE1 is a valuable prognostic marker for HCC. APE1 significantly facilitate HCC development and targeting APE1 may be a promising strategy for HCC treatment.

The NRF2, Thioredoxin, and Glutathione System in Tumorigenesis and Anticancer Therapies

Cancer remains an elusive, highly complex disease and a global burden. Constant change by acquired mutations and metabolic reprogramming contribute to the high inter- and intratumor heterogeneity of malignant cells, their selective growth advantage, and their resistance to anticancer therapies. In the modern era of integrative biomedicine, realizing that a personalized approach could benefit therapy treatments and patients' prognosis, we should focus on cancer-driving advantageous modifications. Namely, reactive oxygen species (ROS), known to act as regulators of cellular metabolism and growth, exhibit both negative and positive activities, as do antioxidants with potential anticancer effects. Such complexity of oxidative homeostasis is sometimes overseen in the case of studies evaluating the effects of potential anticancer antioxidants. While cancer cells often produce more ROS due to their increased growth-favoring demands, numerous conventional anticancer therapies exploit this feature to ensure selective cancer cell death triggered by excessive ROS levels, also causing serious side effects. The activation of the cellular NRF2 (nuclear factor erythroid 2 like 2) pathway and induction of cytoprotective genes accompanies an increase in ROS levels. A plethora of specific targets, including those involved in thioredoxin (TRX) and glutathione (GSH) systems, are activated by NRF2. In this paper, we briefly review preclinical research findings on the interrelated roles of the NRF2 pathway and TRX and GSH systems, with focus given to clinical findings and their relevance in carcinogenesis and anticancer treatments.

Thioredoxin Interacting Protein (TXNIP) Is Differentially Expressed in Human Tumor Samples but Is Absent in Human Tumor Cell Line Xenografts: Implications for Its Use as an Immunosurveillance Marker

Simple Summary

The metabolic protein TXNIP plays a crucial role in various cellular processes. Abnormal TXNIP levels are notable, e.g., in type II diabetes, cardiovascular diseases, and tumors. Using immunohistochemical staining for TXNIP in different tumor entities, we give new insights of TXNIP expression on the protein level. In human tumors, staining intensity inversely correlated with aggressiveness of the tumor entity. In contrast, human tumor cell lines grown in mice (xenografts), consistently revealed no staining. Hence, loss of TXNIP suggests a critical role for the development of tumors in xenografts. Furthermore, we investigated TXNIP staining of immunocompetent cells in the proximity of the xenograft tumor tissue. Our findings demonstrate that TXNIP downregulation is a common feature in human tumor xenograft models. Subsequently, TXNIP expression might be used to monitor the functional state of tumor-infiltrating leukocytes in tissue sections and may help to predict response to modern immune therapy.

Abstract

Thioredoxin interacting protein (TXNIP) is a metabolic protein critically involved in redox homeostasis and has been proposed as a tumor suppressor gene in a variety of malignancies. Accordingly, TXNIP is downregulated in breast, bladder, and gastric cancer and in tumor transplant models TXNIP overexpression inhibits growth and metastasis. As TXNIP protein expression has only been investigated in few malignancies, we employed immunohistochemical detection in a large multi-tumor tissue microarray consisting of 2,824 samples from 94 different tumor entities. In general, TXNIP protein was present only in a small proportion of primary tumor samples and in these cases was differently expressed depending on tumor stage and subtype (e.g., renal cell carcinoma, thyroid cancer, breast cancer, and ductal pancreatic cancer). Further, TXNIP protein expression was determined in primary mouse xenograft tumors derived from human cancer cell lines and was immunohistochemically absent in all xenograft tumors investigated. Intriguingly, TXNIP expression became gradually lower in the proximity of the primary tumor tissue and was absent in leukocytes directly adjacent to tumor tissue. In conclusion, these findings suggest that TXNIP downregulation is as a common feature in human tumor xenograft models and that intra-tumoral leukocytes down-regulate TXNIP. Hence TXNIP expression might be used to monitor the functional state of tumor-infiltrating leukocytes in tissue sections.

A Novel DNA Aptamer Targeting S100P Induces Antitumor Effects in Colorectal Cancer Cells

Colorectal cancer (CRC) is a prevalent malignancy with poor prognosis and survival. As a Ca²⁺ binding protein, S100P plays a role in calcium-dependent signal transduction pathways that involve in diverse biological processes. Our previous studies have shown that S100P is overexpressed in CRC tissues and regulates cell growth, invasion, and metastasis in CRC. Therefore, S100P is expected to be an effective target for CRC therapy. Aptamers are short single-stranded oligonucleotides that could serve as specific and high-affinity probes to a wide range of target molecules for therapeutic purposes. In this study, we generated a novel DNA aptamer against S100P (AptS100P-1) by way of the SELEX process and high-throughput sequencing. The binding assay showed that AptS100P-1 had a high affinity for S100P protein. Further experiments indicated that AptS100P-1 is relatively stable in a cell culture system and could be used in flow cytometry analysis, dot blot assay, and fluorescence microscopy analysis to detect S100P. Moreover, AptS100P-1 was capable of binding to cells and had an inhibitory effect on CRC cell growth in vitro and in vivo. Also, AptS100P-1 inhibited the migration and epithelial-mesenchymal transition of CRC cells expressing S100P. These results indicate a novel DNA aptamer targeting S100P, which might be a potential therapeutic strategy for targeting S100P against S100P-expressing CRC.

Promotion of the occurrence of endometrioid carcinoma by S100 calcium binding protein P

Background

Endometrial cancer, one of the most common malignant tumors, is a serious threat to women’s health. Endometrial hyperplasia is a precursor of endometrial cancer. S100 calcium binding protein P (S100P) has been found to play important roles in many types of cancer. The present study aimed to investigate the expression of S100P in endometrial cancer and its precursor lesions, and to explore the possible mechanisms.

Methods

We collected paraffin sections of normal endometrium, simple and complex non-atypical hyperplasia, atypical hyperplasia, and endometrioid carcinoma. The expression of S100P in endometrial cancer and its precancerous lesions was observed using immunohistochemistry. We also cultured primary endometrial cells and endometrial cancer cell lines (Ishikawa and RL95–2), and observed the expression of S100P in these cells. Laser confocal microscopy was used to observe the co-localization of S100P and its interacting protein Ezrin in RL95–2 cells. We employed lentiviruses to knockdown and overexpress S100P and then detected the F-actin distribution and cell invasion using phalloidin staining and Transwell assays.

Results

There was a gradual increase in the S100P signal as the disease progressed from normal endometrium and simple non-atypical hyperplasia, to complex non-atypical hyperplasia, atypical hyperplasia, and then to endometrial cancer. S100P was mainly distributed in the cytoplasm and co-localized with Ezrin in endometrial cancer cells. After knocking down S100P, F-actin aggregated in the nucleus or to the local cell membrane. Furthermore, knockdown of S100P in Ishikawa cells decreased their cell invasion capability. Meanwhile, S100P overexpression in endometrial stromal cells increased cell invasion.

Conclusions

These data suggested that S100P might be involved in the occurrence and development of endometrial cancer via interaction with Ezrin and re-organization of F-actin to promote cell invasion.

Friend or Foe: S100 Proteins in Cancer

S100 proteins are widely expressed small molecular EF-hand calcium-binding proteins of vertebrates, which are involved in numerous cellular processes, such as Ca²⁺ homeostasis, proliferation, apoptosis, differentiation, and inflammation. Although the complex network of S100 signalling is by far not fully deciphered, several S100 family members could be linked to a variety of diseases, such as inflammatory disorders, neurological diseases, and also cancer. The research of the past decades revealed that S100 proteins play a crucial role in the development and progression of many cancer types, such as breast cancer, lung cancer, and melanoma. Hence, S100 family members have also been shown to be promising diagnostic markers and possible novel targets for therapy. However, the current knowledge of S100 proteins is limited and more attention to this unique group of proteins is needed. Therefore, this review article summarises S100 proteins and their relation in different cancer types, while also providing an overview of novel therapeutic strategies for targeting S100 proteins for cancer treatment.

ROS-Mediated Therapeutic Strategy in Chemo-/Radiotherapy of Head and Neck Cancer

Head and neck cancer is a highly genetic and metabolic heterogeneous collection of malignancies of the lip, oral cavity, salivary glands, pharynx, esophagus, paranasal sinuses, and larynx with five-year survival rates ranging from 12% to 93%. Patients with head and neck cancer typically present with advanced stage III, IVa, or IVb disease and are treated with comprehensive modality including chemotherapy, radiotherapy, and surgery. Despite advancements in treatment modality and technique, noisome recurrence, invasiveness, and resistance as well as posttreatment complications severely influence survival rate and quality of life. Thus, new therapeutic strategies are urgently needed that offer enhanced efficacy with less toxicity. ROS in cancer cells plays a vital role in regulating cell death, DNA repair, stemness maintenance, metabolic reprogramming, and tumor microenvironment, all of which have been implicated in resistance to chemo-/radiotherapy of head and neck cancer. Adjusting ROS generation and elimination to reverse the resistance of cancer cells without impairing normal cells show great hope in improving the therapeutic efficacy of chemo-/radiotherapy of head and neck cancer. In the current review, we discuss the pivotal and targetable redox-regulating system including superoxide dismutases (SODs), tripeptide glutathione (GSH), thioredoxin (Trxs), peroxiredoxins (PRXs), nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/keap1), and mitochondria electron transporter chain (ETC) complexes and their roles in regulating ROS levels and their clinical significance implicated in chemo-/radiotherapy of head and neck cancer. We also summarize several old drugs (referred to as the non-anti-cancer drugs used in other diseases for a long time) and small molecular compounds as well as natural herbs which effectively modulate cellular ROS of head and neck cancer to synergize the efficacy of conventional chemo-/radiotherapy. Emerging interdisciplinary techniques including photodynamic, nanoparticle system, and Bio-Electro-Magnetic-Energy-Regulation (BEMER) therapy are promising measures to broaden the potency of ROS modulation for the benefit of chemo-/radiotherapy in head and neck cancer.

MicroRNA‑199a‑5p suppresses cell proliferation, migration and invasion by targeting ITGA3 in colorectal cancer

As a member of the integrin family, integrin α3β1 (ITGA3) has been linked to intercellular communication and serves an important role in the signaling among cells and the extracellular matrix. MicroRNA (miR)-199a-5p has been demonstrated to be related to the pathogenesis and progression of multiple malignant diseases. However, the biological functions of miR-199a-5p and ITGA3 in colorectal cancer (CRC) have rarely been reported. The aim of the present study was to explore the roles of miR-199a-5p and ITGA3 in CRC. Immunohistochemistry staining and western blotting were applied to detect the protein expression of ITGA3 in CRC tissues and cells. Reverse transcription-quantitative PCR was performed to investigate the expression of miR-199a-5p and ITGA3 mRNA. HCT-116 cells were transfected with miR-199a-5p mimics, mimics control, short hairpin RNA targeting ITGA3, or pcDNA-ITGA3 for the functional experiments. Dual luciferase reporter assay was applied to confirm whether miR-199a-5p targeted the 3′ untranslated region (3′UTR) of ITGA3. The MTT, Transwell and wound healing assays were used to evaluate the proliferation, invasion and migration of CRC cells. Immunofluorescence assay was used to monitor the epithelial-mesenchymal transition (EMT) biomarker expression. The results demonstrated downregulation of miR-199a-5p and upregulation of ITGA3 in CRC tissues and cell lines. miR-199a-5p mimics and knockdown of ITGA3 suppressed the proliferation, invasion and migration of CRC cells. Bioinformatics analysis and luciferase reporter assay indicated that miR-199a-5p targeted the 3′UTR of the ITGA3 transcript, and overexpression of ITGA3 reversed the tumor-suppressive effects of miR-199a-5p elevation. In addition, the immunofluorescence assay suggested that miR-199a-5p mimics suppressed the EMT of CRC cells, whereas the overexpression of ITGA3 restored this effect. In conclusion, miR-199a-5p may act as a tumor suppressor by targeting and negatively regulating ITGA3 in CRC.

Sodium Butyrate Selectively Kills Cancer Cells and Inhibits Migration in Colorectal Cancer by Targeting Thioredoxin-1

Background

Sodium butyrate (NaB) is a short-chain fatty acid which is produced by bacterial fermentation of nondigestible dietary fiber and has been reported to exert anti-tumor effects in many tumors including colorectal cancer (CRC). However, the role of thioredoxin-1 (Trx-1) in NaB-induced anti-tumor effect has not been completely clarified.

Materials and Methods

Effects of NaB on the growth of CRC cell lines HT29 and SW480 were detected by the Cell Counting Kit-8 (CCK-8) and colony formation assays. The apoptotic cells were determined by flow cytometry, and cell migration was assessed by a Transwell assay. Western blot analysis was used to test the Trx-1 and epithelial-to-mesenchymal transition (EMT)-related proteins level. Reactive oxygen species (ROS) level was determined and N-acetylcysteine (NAC) recovery experiment was performed in CRC cells. In addition, mice xenograft model was established to test the effect of NaB on CRC growth in vivo. Further, the effects of NaB on CRC cells with overexpression or knockdown were tested by the CCK-8 and Transwell assays.

Results

NaB treatment significantly inhibited cell growth and decreased Trx-1 protein expression in CRC cells but not in normal colon epithelial cells. NaB also induced apoptosis, inhibited colony formation, migration and EMT in CRC cells. Besides, NaB increased ROS level in CRC cells and NAC reversed NaB-induced inhibition of cell proliferation. Moreover, downregulation of Trx-1 significantly enhanced NaB-induced inhibitory effects on cell growth and migration, whereas overexpression of Trx-1 attenuated NaB-induced inhibitory effects on growth and migration in CRC cells.

Conclusion

These findings indicate that the NaB-mediated anti-tumor effects on CRC cells are related to downregulation of Trx-1.

Control of tumor angiogenesis and metastasis through modulation of cell redox state

Redox reactions pervade all biology. The control of cellular redox state is essential for bioenergetics and for the proper functioning of many biological functions. This review traces a timeline of findings regarding the connections between redox and cancer. There is ample evidence of the involvement of cellular redox state on the different hallmarks of cancer. Evidence of the control of tumor angiogenesis and metastasis through modulation of cell redox state is reviewed and highlighted.

Increased Thioredoxin-1 Expression Promotes Cancer Progression and Predicts Poor Prognosis in Patients with Gastric Cancer

Background

Thioredoxin-1 (Trx-1) is a small redox protein, which plays an important role in many biological processes. Although increased expression of Trx-1 in various solid tumors has been reported, the prognostic significance and function of Trx-1 in human gastric cancer (GC) are still unclear. Here, we investigated the clinical and prognostic significance of Trx-1 expression and the function and mechanism of Trx-1 in human GC.

Methods

We analyzed Trx-1 mRNA expression from the GEO database and Trx-1 protein expression in 144 GC tissues using immunohistochemistry. Effects of Trx-1 on GC cell were assessed in vitro and in vivo through Trx-1 knockdown or overexpression. The antitumor effects of the Trx-1 inhibitor, PX-12, on GC cells were investigated. PTEN and p-AKT expressions were evaluated by Western blotting.

Results

Increased Trx-1 expression was found in GC tissues and associated with poor prognosis and aggressive clinicopathological characteristics in patients with GC. High Trx-1 expression predicted poor prognosis, and its expression was an independent prognostic factor for overall survival of GC patients. Knockdown of Trx-1 expression inhibited GC cell growth, migration, and invasion in vitro and tumor growth and lung metastasis in vivo. Conversely, overexpression of Trx-1 promoted GC cell growth, migration, and invasion. We also found that PX-12 inhibited GC cell growth, migration, and invasion. Overexpression of Trx-1 caused a decrease in PTEN and increase in p-AKT levels whereas silencing Trx-1 caused an increase in PTEN and decrease in p-AKT levels in GC cells. Inhibition of AKT signaling pathway by MK2206 also inhibited GC cell growth, migration, and invasion.

Conclusion

Our results indicate that Trx-1 may be a promising prognostic indicator and therapeutic target for GC patients.

mRNA-miRNA bipartite network reconstruction to predict prognostic module biomarkers in colorectal cancer stage differentiation

Biomarker detection is one of the most important and challenging problems in cancer studies. Recently, non-coding RNA based biomarkers such as miRNA expression levels have been used for early diagnosis of many cancer types. In this study, a systems biology approach was used to detect novel miRNA based biomarkers for CRC diagnosis in early stages. The mRNA expression data from three CRC stages (Low-grade Intraepithelial Neoplasia (LIN), High-grade Intraepithelial Neoplasia (HIN) and Adenocarcinoma) were used to reconstruct co-expression networks. The networks were clustered to extract co-expression modules and detected low preserved modules among CRC stages. Then, the experimentally validated mRNA-miRNA interaction data were applied to reconstruct three mRNA-miRNA bipartite networks. Twenty miRNAs with the highest degree (hub miRNAs) were selected in each bipartite network to reconstruct three bipartite subnetworks for further analysis. The analysis of these hub miRNAs in the bipartite subnetworks revealed 30 distinct important miRNAs as prognostic markers in CRC stages. There are two novel CRC related miRNAs (hsa-miR-190a-3p and hsa-miR-1277-5p) in these 30 hub miRNAs that have not been previously reported in CRC. Furthermore, a drug-gene interaction network was reconstructed to detect potential candidate drugs for CRC treatment. Our analysis shows that the hub miRNAs in the mRNA-miRNA bipartite network are very essential in CRC progression and should be investigated precisely in future studies. In addition, there are many important target genes in the results that may be critical in CRC progression and can be analyzed as therapeutic targets in future research.

Interplay between Trx-1 and S100P promotes colorectal cancer cell epithelial-mesenchymal transition by up-regulating S100A4 through AKT activation

We previously reported a novel positive feedback loop between thioredoxin‐1 (Trx‐1) and S100P, which promotes the invasion and metastasis of colorectal cancer (CRC). However, the underlying molecular mechanisms remain poorly understood. In this study, we examined the roles of Trx‐1 and S100P in CRC epithelial‐to‐mesenchymal transition (EMT) and their underlying mechanisms. We observed that knockdown of Trx‐1 or S100P in SW620 cells inhibited EMT, whereas overexpression of Trx‐1 or S100P in SW480 cells promoted EMT. Importantly, S100A4 and the phosphorylation of AKT were identified as potential downstream targets of Trx‐1 and S100P in CRC cells. Silencing S100A4 or inhibition of AKT phosphorylation eliminated S100P‐ or Trx‐1‐mediated CRC cell EMT, migration and invasion. Moreover, inhibition of AKT activity reversed S100P‐ or Trx‐1‐induced S100A4 expression. The expression of S100A4 was higher in human CRC tissues compared with their normal counterpart tissues and was significantly correlated with lymph node metastasis and poor survival. The overexpression of S100A4 protein was also positively correlated with S100P or Trx‐1 protein overexpression in our cohort of CRC tissues. In addition, overexpression of S100P reversed the Trx‐1 knockdown‐induced inhibition of S100A4 expression, EMT and migration and invasion in SW620 cells. The data suggest that interplay between Trx‐1 and S100P promoted CRC EMT as well as migration and invasion by up‐regulating S100A4 through AKT activation, thus providing further potential therapeutic targets for suppressing the EMT in metastatic CRC.

Redox-Inactive Peptide Disrupting Trx1-Ask1 Interaction for Selective Activation of Stress Signaling

Thioredoxin 1 (Trx1) and glutaredoxin 1 (Grx1) are two ubiquitous redox enzymes that are central for redox homeostasis but also are implicated in many other processes, including stress sensing, inflammation, and apoptosis. In addition to their enzymatic redox activity, a growing body of evidence shows that Trx1 and Grx1 play regulatory roles via protein-protein interactions with specific proteins, including Ask1. The currently available inhibitors of Trx1 and Grx1 are thiol-reactive electrophiles or disulfides that may suffer from low selectivity because of their thiol reactivity. In this report, we used a phage peptide library to identify a 7-mer peptide, 2GTP1, that binds to both Trx1 and Grx1. We further showed that a cell-permeable derivative of 2GTP1, TAT-2GTP1, disrupts the Trx1-Ask1 interaction, which induces Ask1 phosphorylation with subsequent activation of JNK, stabilization of p53, and reduced viability of cancer cells. Notably, as opposed to a disulfide-derived Trx1 inhibitor (PX-12), TAT-2GTP1 was selective for activating the Ask1 pathway without affecting other stress signaling pathways, such as endoplasmic reticulum stress and AMPK activation. Overall, 2GTP1 will serve as a useful probe for investigating protein interactions of Trx1.