Thioredoxin-like protein 2b facilitates colon cancer cell proliferation and inhibits apoptosis via NF-κB pathway

GLRX3, a novel cancer stem cell-related secretory biomarker of pancreatic ductal adenocarcinoma

Background

Cancer stem cells (CSCs) are implicated in carcinogenesis, cancer progression, and recurrence. Several biomarkers have been described for pancreatic ductal adenocarcinoma (PDAC) CSCs; however, their function and mechanism remain unclear.

Method

In this study, secretome analysis was performed in pancreatic CSC-enriched spheres and control adherent cells for biomarker discovery. Glutaredoxin3 (GLRX3), a novel candidate upregulated in spheres, was evaluated for its function and clinical implication.

Results

PDAC CSC populations, cell lines, patient tissues, and blood samples demonstrated GLRX3 overexpression. In contrast, GLRX3 silencing decreased the in vitro proliferation, migration, clonogenicity, and sphere formation of cells. GLRX3 knockdown also reduced tumor formation and growth in vivo. GLRX3 was found to regulate Met/PI3K/AKT signaling and stemness-related molecules. ELISA results indicated GLRX3 overexpression in the serum of patients with PDAC compared to that in healthy controls. The sensitivity and specificity of GLRX3 for PDAC diagnosis were 80.0 and 100%, respectively. When GLRX3 and CA19–9 were combined, sensitivity was significantly increased to 98.3% compared to that with GLRX3 or CA19–9 alone. High GLRX3 expression was also associated with poor disease-free survival in patients receiving curative surgery.

Conclusion

Overall, these results indicate GLRX3 as a novel diagnostic marker and therapeutic target for PDAC targeting CSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08898-y.

Alternative splicing of mRNA in colorectal cancer: new strategies for tumor diagnosis and treatment

Alternative splicing (AS) is an important event that contributes to posttranscriptional gene regulation. This process leads to several mature transcript variants with diverse physiological functions. Indeed, disruption of various aspects of this multistep process, such as cis- or trans- factor alteration, promotes the progression of colorectal cancer. Therefore, targeting some specific processes of AS may be an effective therapeutic strategy for treating cancer. Here, we provide an overview of the AS events related to colorectal cancer based on research done in the past 5 years. We focus on the mechanisms and functions of variant products of AS that are relevant to malignant hallmarks, with an emphasis on variants with clinical significance. In addition, novel strategies for exploiting the therapeutic value of AS events are discussed.

Substrate specificity of thioredoxins and glutaredoxins - towards a functional classification

The spatio-temporal reduction and oxidation of protein thiols is an essential mechanism in signal transduction in all kingdoms of life. Thioredoxin (Trx) family proteins efficiently catalyze thiol-disulfide exchange reactions and the proteins are widely recognized for their importance in the operation of thiol switches. Trx family proteins have a broad and at the same time very distinct substrate specificity – a prerequisite for redox switching. Despite of multiple efforts, the true nature for this specificity is still under debate. Here, we comprehensively compare the classification/clustering of various redoxins from all domains of life based on their similarity in amino acid sequence, tertiary structure, and their electrostatic properties. We correlate these similarities to the existence of common interaction partners, identified in various previous studies and suggested by proteomic screenings. These analyses confirm that primary and tertiary structure similarity, and thereby all common classification systems, do not correlate to the target specificity of the proteins as thiol-disulfide oxidoreductases. Instead, a number of examples clearly demonstrate the importance of electrostatic similarity for their target specificity, independent of their belonging to the Trx or glutaredoxin subfamilies.

Gold-Based Medicine: A Paradigm Shift in Anti-Cancer Therapy?

A new era of metal-based drugs started in the 1960s, heralded by the discovery of potent platinum-based complexes, commencing with cisplatin [(H₃N)₂PtCl₂], which are effective anti-cancer chemotherapeutic drugs. While clinical applications of gold-based drugs largely relate to the treatment of rheumatoid arthritis, attention has turned to the investigation of the efficacy of gold(I) and gold(III) compounds for anti-cancer applications. This review article provides an account of the latest research conducted during the last decade or so on the development of gold compounds and their potential activities against several cancers as well as a summary of possible mechanisms of action/biological targets. The promising activities and increasing knowledge of gold-based drug metabolism ensures that continued efforts will be made to develop gold-based anti-cancer agents.

Glutaredoxin 3 promotes migration and invasion via the Notch signalling pathway in oral squamous cell carcinoma

Substantial evidence indicates that the alteration of the cellular redox status is a critical factor involved in cell growth and death and results in tumourigenesis. Cancer cells have an efficient antioxidant system to counteract the increased generation of ROS. However, whether this ability to survive high levels of ROS has an important role in the growth and metastasis of tumours is not well understood. Glutaredoxin 3 (GLRX3), also known as TXNL2, Grx3 and PICOT, maintains a low level of ROS, thus contributing to the survival and metastasis of several types of cancer. However, little is known about the role of GLRX3 and the underlying mechanisms that suppress oral squamous cell carcinoma (OSCC) progression. Here, by using immunohistochemical staining, we demonstrated that GLRX3 was overexpressed in human OSCC, and enhanced GLRX3 expression correlated with metastasis and with decreased overall patient survival. Knockdown of GLRX3 in human OSCC cell lines reduced Notch activity by reversing the epithelial-mesenchymal transition (EMT), resulting in the inhibition of in vitro migration and invasion. Importantly, knockdown of GLRX3 triggered the generation of ROS. Furthermore, N-acetyl cysteine (NAC), an ROS scavenger, enhanced the effects of GLRX3 knockdown on Notch-dependent EMT. Collectively, these findings suggested the vital roles of GLRX3 in OSCC progression through its relationship with EMT progression, and these data also suggest that a strategy of blocking ROS to enhance the activity of GLRX3 knockdown warrants further attention in the treatment of OSCC.

Dishevelled1-3 contribute to multidrug resistance in colorectal cancer via activating Wnt/β-catenin signaling

Multidrug resistance is a great obstacle in successful chemotherapy of colorectal cancer. However, the molecular mechanism underlying multidrug resistance is not fully understood. Dishevelled, a pivot in Wnt signaling, has been linked to cancer progression, while its role in chemoresistance remains unclear. Here, we found that Dishevelled1-3 was over-expressed in multidrug-resistant colorectal cancer cells (HCT-8/VCR) compared to their parental cells. Silencing Dishevelled1-3 resensitized HCT-8/VCR cells to multiple drugs including vincristine, 5-fluorouracil and oxaliplatin. Moreover, Dishevelled1-3 increased the protein levels of multidrug resistance protein 1 (P-gp/MDR1), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), Survivin and Bcl-2 which are correlated with multidrug resistance. shβ-catenin abolished Dishevelled-mediated these protein expressions. Unexpectedly, none of Dishevelled1-3 controlled β-catenin accumulation and nuclear translocation. Furthermore, the nuclear translocations of Dishevelled1-3 were promoted in HCT-8/VCR cells compared to HCT-8. Dishevelled1-3 bound to β-catenin in nucleus, and promoted nuclear complex formation and transcription activity of β-catenin/TCF. Taken together, Dishevelled1-3 contributed to multidrug resistance in colorectal cancer via activating Wnt/β-catenin signaling and inducing the expressions of P-gp, MRP2, BCRP, Survivin and Bcl-2, independently of β-catenin accumulation and nuclear translocation. Silencing Dishevelled1-3 resensitized multidrug-resistant colorectal cancer cells, providing a novel therapeutic target for successful chemotherapy of colorectal cancer.

Excretory/secretory products from two Fasciola hepatica isolates induce different transcriptional changes and IL-10 release in LPS-activated bovine "BOMA" macrophages

Fasciola hepatica are trematodes that reside in the bile ducts of mammals. Infection causes US$3 billion in losses annually in animal production and is considered a zoonosis of growing importance. An under-represented area in F. hepatica research has been the examination of the different immunomodulatory abilities of various parasite isolates on the host immune system. In this paper, this issue was explored, with the bovine macrophage cell line "BOMA". The cells were matured by LPS treatment and stimulated with excretory/secretory antigens (ES) from two Fasciola hepatica isolates: a laboratory isolate "Weybridge" (Fh-WeyES) and a wild isolate (Fh-WildES). As expected, stimulation with antigen mixtures with highly similar compositions resulted in mild transcriptomic differences. However, there were significant differences in cytokine levels. Compared to Fh-WeyES, exposure to Fh-WildES upregulated 27 and downregulated 30 genes. Fh-ES from both isolates diminished the release of TNF-α, whereas only Fh-WildES decreased IL-10 secretion. Neither Fh-WeyES nor Fh-WildES had an impact on IL-12 release. Our results indicate that various isolates can have different immunomodulatory abilities and impacts on the bovine immune system.

Silencing of hERG1 Gene Inhibits Proliferation and Invasion, and Induces Apoptosis in Human Osteosarcoma Cells by Targeting the NF-κB Pathway

Recently, the human ether à go-go (eag) related gene 1 (hERG1) channel, a member of the voltage-dependent potassium channel (Kv) family, was determined to have a critical role in cancer cell proliferation, invasion, tumorigenesis and apoptosis. However, the expression levels and functions of hERG1 in osteosarcoma cells remain poorly characterized. In this study, hERG1 transcript and protein levels in osteosarcoma cells and tissues were measured using semi-quantitative real time PCR (RT-PCR), Western blot, and immunohistochemistry. The effects of hERG1 knockdown on osteosarcoma cell proliferation, apoptosis and invasion were examined using CCK-8, colony formation, flow cytometry, caspase-3 activity, wound healing and transwell based assays. Furthermore, semi-quantitative RT-PCR, Western blot and a luciferase reporter assay were used to assess the effects of hERG1 inhibition on the nuclear factor-κB (NF-κB) pathway. In addition, the effect of NF-κB p65-siRNA and NF-κB p65 expression on the survival of osteosarcoma cells was investigated. Through this work, a relationship for hERG1 with the NF-κB pathway was identified. Osteosarcoma cells and tissues were found to express high levels of hERG1. Knockdown of hERG1 significantly suppressed cellular proliferation and invasion, and induced apoptosis, while inhibition of hERG1 significantly decreased activation of NF-κB. Overall, hERG1 may stimulate nuclear translocation of p65, thus regulating the NF-κB pathway through the activation of the hERG1/beta1 integrin complex and PI3K/AKT signaling. Taken together, these results demonstrate that hERG1 is necessary for regulation of osteosarcoma cellular proliferation, apoptosis and migration. Furthermore, this regulation by hERG1 is, at least in part, through mediation of the NF-κB pathway.

miR-483-3p plays an oncogenic role in esophageal squamous cell carcinoma by targeting tumor suppressor EI24

microRNAs (miRNAs), through negatively regulating their target genes, influence the development and progression of many cancers. Previously, we found miR-483 was overexpressed in esophageal squamous cell carcinoma (ESCC) tissues, and its overexpression was negatively correlated with the prognosis and positively correlated with multidrug resistance of ESCC, but whether it could affect the biological role of proliferation and migration in ESCC cell lines is unknown. In the present study, we found miR-483-3p was overexpressed in ESCC cell lines as compared with the normal esophageal squamous epithelial cell line. Functional experiments in vitro showed that miR-483-3p could promote the proliferation, migration, transformation of cell cycle from G1 phase to G2 phase of ESCC cells and could inhibit cells' sensitivity to chemotherapy drugs. Nude mouse tumorigenicity assay indicated that miR-483-3p could promote the growth of ESCC cells in vivo. Western blot assay showed that ectopic expression of miR-483-3p in ESCC cells could downregulate the protein level of etoposide induced 2.4 (EI24), which is a tumor suppressor and has not been reported in ESCC. Luciferase reporter assay demonstrated that EI24 was a direct target of miR-483-3p. Collectively, our study demonstrated that miR-483-3p could promote ESCC progression at least in part through directly targeting EI24, supplying a potential strategy for miRNA-based ESCC therapy.

Biomarker Development for Intraductal Papillary Mucinous Neoplasms Using Multiple Reaction Monitoring Mass Spectrometry

Intraductal papillary mucinous neoplasm (IPMN) is a common precursor of pancreatic cancer (PC). Much clinical attention has been directed toward IPMNs due to the increase in the prevalence of PC. The diagnosis of IPMN depends primarily on a radiological examination, but the diagnostic accuracy of this tool is not satisfactory, necessitating the development of accurate diagnostic biomarkers for IPMN to prevent PC. Recently, high-throughput targeted proteomic quantification methods have accelerated the discovery of biomarkers, rendering them powerful platforms for the evolution of IPMN diagnostic biomarkers. In this study, a robust multiple reaction monitoring (MRM) pipeline was applied to discovery and verify IPMN biomarker candidates in a large cohort of plasma samples. Through highly reproducible MRM assays and a stringent statistical analysis, 11 proteins were selected as IPMN marker candidates with high confidence in 184 plasma samples, comprising a training (n = 84) and test set (n = 100). To improve the discriminatory power, we constructed a six-protein panel by combining marker candidates. The multimarker panel had high discriminatory power in distinguishing between IPMN and controls, including other benign diseases. Consequently, the diagnostic accuracy of IPMN can be improved dramatically with this novel plasma-based panel in combination with a radiological examination.

Upregulation of RICTOR gene transcription by the proinflammatory cytokines through NF-κB pathway contributes to the metastasis of renal cell carcinoma

Metastasis accounts for more than 50 % of deaths among renal cell carcinoma (RCC) patients, and therefore, it is important to study the biology of metastasis and identify metastasis-associated biomarkers for risk prognosis and stratification of patients for an individualized therapy of RCC. In cultured RCC cells, knockdown of Rictor by short hairpin RNA (shRNA) inhibited cell migration and invasion, probably due to impairments in activation of Akt. Pretreatment with tumor necrosis factor α (TNFα) or interleukin 6 (IL-6) enhanced the expression of Rictor and the migration of renal cancer cells. Mechanistic analysis showed that TNFα induced the activation of NF-κB in RCC cells. Luciferase reporter analysis revealed a NF-κB responding element (-301 to -51 bp) at the promoter region of Rictor. Chromatin immunoprecipitation (ChIP) analysis further confirmed that TNFα-induced binding of p65 with the promoter of Rictor. In a xenograft model, knockdown of Rictor-blocked RCC cells metastasis to the mouse lungs and livers. Taken together, our results suggest that the proinflammatory cytokine TNFα promotes the expression of Rictor through the NF-κB pathway.