TRIB1 promotes colorectal cancer cell migration and invasion through activation MMP-2 via FAK/Src and ERK pathways

"Oh, Dear We Are in Tribble": An Overview of the Oncogenic Functions of Tribbles 1

Pseudokinases are catalytically inactive proteins in the human genome that lack the ability to transfer phosphate from ATP to their substrates. The Tribbles family of pseudokinases contains three members: Tribbles 1, 2, and 3. Tribbles 1 has recently gained importance because of its involvement in various diseases, including cancer. It acts as a scaffolding protein that brings about the degradation of its substrate proteins, such as C/EBPα/β, MLXIPL, and RAR/RXRα, among others, via the ubiquitin proteasome system. It also serves as an adapter protein, which sequesters different protein molecules and activates their downstream signaling, leading to processes, such as cell survival, cell proliferation, and lipid metabolism. It has been implicated in cancers such as AML, prostate cancer, breast cancer, CRC, HCC, and glioma, where it activates oncogenic signaling pathways such as PI3K-AKT and MAPK and inhibits the anti-tumor function of p53. TRIB1 also causes treatment resistance in cancers such as NSCLC, breast cancer, glioma, and promyelocytic leukemia. All these effects make TRIB1 a potential drug target. However, the lack of a catalytic domain renders TRIB1 "undruggable", but knowledge about its structure, conformational changes during substrate binding, and substrate binding sites provides an opportunity to design small-molecule inhibitors against specific TRIB1 interactions.

Single nucleotide polymorphisms and Zn transport by ZIP11 shape functional phenotypes of HeLa cells

Zinc (Zn) is a vital micronutrient with essential roles in biological processes like enzyme function, gene expression, and cell signaling. Disruptions in the cellular regulation of Zn2+ ions often lead to pathological states. Mammalian Zn transporters, such as ZIP11, play a key role in homeostasis of this ion. ZIP11 resides predominately in the nucleus and Golgi apparatus. Our laboratory reported a function of ZIP11 in maintaining nuclear Zn levels in HeLa cervical cancer cells. Analyses of cervical and ovarian cancer patients' datasets identified four coding, single nucleotide polymorphisms (SNPs) in SLC39A11, the gene that encodes ZIP11, correlating with disease severity. We hypothesized that these SNPs might translate to functional changes in the ZIP11 protein by modifying access to substrate availability. We also proposed that a metal-binding site (MBS) in ZIP11 is crucial for transmembrane Zn2+ transport and required for maintenance of various pathogenic phenotypes observed in HeLa cells. Here, we investigated these claims by re-introducing single the SLC39A11 gene encoding for mutant residues associated with the SNPs, as well as MBS mutations into HeLa cells knocked down for the transporter. Some SNPs-encoding ZIP11 variants rescued Zn levels, proliferation, migration, and invasiveness of knockdown (KD) cells. Conversely, single MBS mutations mimicked the traits of KD cells, confirming the transporter's role in establishing and maintaining proliferative, migratory, and invasive traits. Overall, the intricate role of Zn in cellular dynamics and cancer progression underscores the significance of Zn transporters like ZIP11 in potential therapeutic interventions.

ANP32A Knockdown Attenuates the Malignant Biological Behavior of Colorectal Cancer Cells by Suppressing Epithelial-mesenchymal Transition and ERK Activation

Acidic leucine rich nuclear phosphoprotein-32A (ANP32A) protein has a variety of functions, such as regulating cell differentiation, influencing cell apoptosis and cell cycle progression. Our previous study demonstrated that high expression of ANP32A was found in the tumor tissues of colorectal cancer (CRC) patients and was positively associated with tumor grading. However, the function and underlying mechanisms of ANP32A in CRC metastasis have not been fully explored. In this study, we found that ANP32A knockdown significantly attenuated the migration and invasion, and epithelial-mesenchymal transition (EMT) in cells. Further mechanistic studies revealed that ANP32A knockdown inhibited the expression of β-catenin and phosphorylated-ERK. The immunofluorescent staining experiment has revealed that ANP32A was expressed in the cell membrane, cytosol and nucleus, and its expression was positively associated with β-catenin expression levels. Moreover, the ability of cell migration and invasion was inhibited, the expression of E-cadherin was enhanced following ANP32A knockdown, and these affects were abolished by an ERK activator PMA, enhanced by an ERK inhibitor PD98059. Moreover, our animal experiment also demonstrated that silenced ANP32A inhibited CRC cell growth, multi-organ metastasis, ERK activation and EMT progression in vivo. Collectively, these findings demonstrated that ANP32A promotes CRC progression and that may be a promising target for the anti-metastasis treatment of CRC.

Breast stiffness, a risk factor for cancer and the role of radiology for diagnosis

Over the last five decades, breast density has been associated with increased risk of developing breast cancer. Mammographically dense breasts are considered those belonging to the heterogeneously dense breasts, and extremely dense breasts subgroups according to the American College of Radiology's Breast Imaging Reporting and Data System (BI-RADS). There is a statistically significant correlation between the increased mammographic density and the presence of more glandular tissue alone. However, the strength of this correlation is weak. Although the mechanisms driving breast density-related tumor initiation and progression are still unknown, there is evidence suggesting that certain molecular pathways participating in epithelial-stromal interactions may play a pivotal role in the deposition of fibrillar collagen, increased matrix stiffness, and cell migration that favor breast density and carcinogenesis. This article describes these molecular mechanisms as potential "landscapers" for breast density-related cancer. We also introduce the term "Breast Compactness" to reflect collagen density of breast tissue on chest CT scan and the use of breast stiffness measurements as imaging biomarkers for breast cancer screening and risk stratification.

TRIB1 confers therapeutic resistance in GBM cells by activating the ERK and Akt pathways

GBM (Glioblastoma) is the most lethal CNS (Central nervous system) tumor in adults, which inevitably develops resistance to standard treatments leading to recurrence and mortality. TRIB1 is a serine/threonine pseudokinase which functions as a scaffold platform that initiates degradation of its substrates like C/EBPα through the ubiquitin proteasome system and also activates MEK and Akt signaling. We found that increased TRIB1 gene expression associated with worse overall survival of GBM patients across multiple cohorts. Importantly, overexpression of TRIB1 decreased RT/TMZ (radiation therapy/temozolomide)-induced apoptosis in patient derived GBM cell lines in vitro. TRIB1 directly bound to MEK and Akt and increased ERK and Akt phosphorylation/activation. We also found that TRIB1 protein expression was maximal during G2/M transition of cell cycle in GBM cells. Furthermore, TRIB1 bound directly to HDAC1 and p53. Importantly, mice bearing TRIB1 overexpressing tumors had worse overall survival. Collectively, these data suggest that TRIB1 induces resistance of GBM cells to RT/TMZ treatments by activating the cell proliferation and survival pathways thus providing an opportunity for developing new targeted therapeutics.

Cortactin contributes to the tumorigenesis of gastric cancer by activating ERK/MMP pathway

Gastric cancer is a malignant tumor with high mortality and high incidence. This study aims to explore the function and molecular mechanism of Cortactin on gastric cancer progression in vitro and in vivo. A bioinformatics analysis from TCGA displayed that Cortactin was highly expressed in gastric cancer samples, and patients with a high Cortactin level had a worse survival rate. Subsequently, we investigated the specific mechanism of action of A in gastric cancer by collecting patient samples for immunohistochemistry, WB, qRT-PCR, cell transfection, cell invasion and metastasis, and constructing tumor xenografts in nude mice. Overexpression of Cortactin inhibited apoptosis and enhanced cellular proliferation and mobility in AGS cells, while those activities were reversed by the knockdown of MMP2 or MMP9. Conversely, the deletion of Cortactin induced apoptosis and suppressed cell growth and metastasis in SGC7901 cells, whereas those behaviors were inhibited by overexpression of MMP2 or MMP9. Additionally, the ERK pathway was activated by Cortactin upregulation. In vivo studies presented that overexpression of Cortactin promoted tumor growth, increased Ki67 expression, and reduced caspase 3 expression, which was reversed by ERK inhibitor treatment. In conclusion, Cortactin acted as an oncogene in gastric cancer and exerted its function by ERK/MMP2/MMP9 signaling pathway.

Plasminogen activator, urokinase enhances the migration, invasion, and proliferation of colorectal cancer cells by activating the Src/ERK pathway

Background

This paper aims to explore the effects of plasminogen activator, urokinase (PLAU) expression on the migration, invasion, and proliferation of colorectal cancer (CRC) cells and to preliminarily analyze its possible mechanism, thereby laying a foundation for the research on potential biological targets of CRC.

Methods

CRC-related mRNA was screened in Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/gds/). Differentially expressed genes (DEGs) were obtained for functional enrichment analysis. The enriched pathway and key involved functional gene were screened for further in vitro and in vivo analysis CRC cells were transfected with PLAU-NC (negative control), PLAU-mimic, and PLAU-inhibitor for 48 h and divided into the above groups for later studies. The migration, invasion, and proliferation capacities of CRC cells were detected using wound healing, Transwell, and colony formation assays, respectively. The Src inhibitor saracatinib (AZD0530) was added to the PLAU-NC and PLAU-mimic groups, and the expression levels of Src/extracellular signal-regulated kinase (ERK) pathway-, migration-, invasion-, and proliferation-related proteins were detected by Western blotting.

Results

The results showed that after upregulation of PLAU, the number of CRC cells (SW480) that migrated to the center of the wound significantly increased, the number of cells that migrated and invaded through the basement membrane increased in the PLAU-mimic group, and the number of colonies also increased. These results suggest that increasing PLAU expression promotes the migration, invasion, and proliferation of CRC cells. At the same time, the molecular mechanism of PLAU in CRC cells was investigated by downregulating the protein expression of Src combined with the results of the bioinformatics analysis. Western blotting revealed that the protein expressions of phosphorylated Src (p-Src) and phosphorylated ERK (p-ERK) in SW480 and SW620 cells increased significantly in the PLAU-mimic group compared with the PLAU-NC group, while the results were the opposite in the PLAU-inhibitor group. After being treated with saracatinib, we observed significantly decreased protein levels of p-ERK, matrix metallopeptidase 2 (MMP-2), MMP-3, MMP-9, Cyclin D1, and Cyclin A2 in the SW480 cells.

Conclusions

In conclusion, PLAU affects the migration, invasion, and proliferation of CRC cells by activating the Src/ERK pathway.

Exosomal circRNA Scm-like with four malignant brain tumor domains 2 (circ-SFMBT2) enhances the docetaxel resistance of prostate cancer via the microRNA-136-5p/tribbles homolog 1 pathway

Exosomal circular RNA was found to mediate cancer chemoresistance. However, whether exosomal circRNA Scm-like with four malignant brain tumor domains 2 (circ-SFMBT2) was involved in the chemoresistance of prostate cancer (PCa) remains unclear. The docetaxel (DTX) resistance of PCa cells was analyzed by Cell Counting Kit 8 assay. Quantitative real-time PCR was used to measure circSFMBT2, microRNA (miR)-136-5p and tribbles homolog 1 (TRIB1) expression. Cell proliferation, apoptosis, migration and invasion were analyzed by 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound-healing assay and transwell assay. RNA interaction was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Protein expression was measured by western blot analysis. Exosomes-extracted from cells were identified by transmission electron microscope, nanoparticles tracking analysis and western blot. Xenograft mice models were constructed to analyze the effect of exosomal circSFMBT2 on the DTX sensitivity of PCa tumors in vivo. CircSFMBT2 was upregulated in DTX-resistant PCa cells, and its knockdown enhanced the DTX sensitivity of DTX-resistant PCa cells by suppressing cell proliferation, migration, invasion and enhancing apoptosis. CircSFMBT2 severed as miR-136-5p sponge to positively regulate TRIB1. The regulation of circSFMBT2 knockdown on the DTX sensitivity of DTX-resistant PCa cells could be reversed by miR-136-5p inhibitor or TRIB1 overexpression. Exosomal circSFMBT2 from DTX-resistant PCa could increase the DTX resistance of normal PCa cells. In addition, exosomal circSFMBT2 also enhanced the DTX resistance of PCa tumors in vivo, and it was highly expressed in the serum of DTX-resistance PCa patients. Exosomal circSFMBT2 enhanced the DTX resistance of PCa by miR-136-5p/TRIB1 axis, indicating that circSFMBT2 might be a potential target for the treatment of PCa chemoresistance.

The Pseudokinase TRIB1 in Immune Cells and Associated Disorders

Simple Summary

TRIB1 is at the center of major cell signaling pathways. In this review, we describe its role in immune cells and highlight TRIB1 interacting partners which suggests cell-specific functions and that TRIB1 is involved in cellular homeostasis and also in different cancers and immune-related disorders.

Abstract

Research advances in Tribbles homolog (TRIB) genes have established the consensus that this protein family plays roles in diverse biological conditions and regulates intracellular signaling networks and several human diseases. In this review, we focus on one member of the family, TRIB1, and its role at the crossroads of immune signaling. TRIB1 directly interacts with transcription factors such as FOXP3 and C/EBPα, with several signaling molecules such as MEK1 and MALT1 and directly acts on key cell signaling pathways such as the MAPK and NF-κB pathways. Altogether, these interactions emphasize that TRIB1 is at the center of major cell signaling pathways while TRIB1 has cell-specific roles, potentially depending on the expressing cells and binding partners. In this review, we describe its roles in immune cells and highlight the interacting partners explaining these functions which suggests TRIB1 as a precise mediator of cellular homeostasis as well as in different cancers and immune-related disorders.

Tribbles Gene Expression Profiles in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death due to cancer in the world. Therefore, the identification of novel druggable targets is urgently needed. Tribbles proteins belong to a pseudokinase family, previously recognized in CRC as oncogenes and potential therapeutic targets. Here, we analyzed the expression of TRIB1, TRIB2, and TRIB3 simultaneously in 33 data sets from CRC based on available GEO profiles. We show that all three Tribbles genes are overrepresented in CRC cell lines and primary tumors, though depending on specific features of the CRC samples. Higher expression of TRIB2 in the tumor microenvironment and TRIB3 overexpression in an early stage of CRC development, unveil a potential and unexplored role for these proteins in the context of CRC. Differential Tribbles expression was also explored in diverse cellular experimental conditions where either genetic or pharmacological approaches were used, providing novel hints for future research. This comprehensive bioinformatic analysis provides new insights into Tribbles gene expression and transcript regulation in CRC.

Tribbles Gene Expression Profiles in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of death due to cancer in the world. Therefore, the identification of novel druggable targets is urgently needed. Tribbles proteins belong to a pseudokinase family, previously recognized in CRC as oncogenes and potential therapeutic targets. Here, we analyzed the expression of TRIB1, TRIB2, and TRIB3 simultaneously in 33 data sets from CRC based on available GEO profiles. We show that all three Tribbles genes are overrepresented in CRC cell lines and primary tumors, though depending on specific features of the CRC samples. Higher expression of TRIB2 in the tumor microenvironment and TRIB3 overexpression in an early stage of CRC development, unveil a potential and unexplored role for these proteins in the context of CRC. Differential Tribbles expression was also explored in diverse cellular experimental conditions where either genetic or pharmacological approaches were used, providing novel hints for future research. This comprehensive bioinformatic analysis provides new insights into Tribbles gene expression and transcript regulation in CRC.

miR-513b-5p inhibits the proliferation and promotes apoptosis of retinoblastoma cells by targeting TRIB1

MicroRNAs are involved in the pathogenesis of various human malignant tumors. This study aims to explore the role of miR-513b-5p in the malignant proliferation of retinoblastoma (RB) cells and its potential molecular mechanisms. The function-gain and function-loss experiments were performed in Weri-RB1 cells using miR-513b-5 mimics and inhibitors. miR-513b-5p mimics inhibited the proliferation and clone formation and promoted apoptosis of Weri-RB1 cells. In contrast, the miR-513b-5p inhibitor promoted the proliferation and clone formation of Weri-RB1 cells and inhibited cell apoptosis. miR-513b-5p can directly bind to the 3'UTR region of TRIB1 mRNA, and inhibit its protein expression. Overexpression of TRIB1 promoted the proliferation and cloning of Weri-RB1 cells but inhibited their apoptosis. The knockdown of TRIB1 inhibited the proliferation and clone formation of Weri-RB1 cells and promoted cell apoptosis. In addition, miR-513b-5p mimics neutralized the effects of TRIB1 overexpression on the proliferation and apoptosis of Weri-RB1 cells. Finally, miR-513b-5p can inhibit the phosphorylation level of AKT, mTOR, and p70, while TRIB1 played the opposite role. miR-513b-5p inhibits the malignant proliferation of Weri-RB1 cells by repressing the expression of TRIB1. miR-513b-5p and TRIB1 may be the biomarkers and/or key targets for clinical diagnosis and treatment of RB.

Current Progress in Delineating the Roles of Pseudokinase TRIB1 in Controlling Human Diseases

Tribbles homolog 1 (TRIB1) is a member of the tribbles family of pseudoprotein kinases and is widely expressed in numerous tissues, such as bone marrow, skeletal muscle, liver, heart, and adipose tissue. It is closely associated with acute myeloid leukemia, prostate cancer, and tumor drug resistance, and can interfere with the hematopoietic stem cell cycle, promote tumor cell proliferation, and inhibit apoptosis. Recent studies have shown that TRIB1 can regulate acute and chronic inflammation by affecting the secretion of inflammatory factors, which is closely related to the occurrence of hyperlipidemia and cardiovascular diseases. Given the important biological functions of TRIB1, the reviews published till now are not sufficiently comprehensive. Therefore, this paper reviews the progress in TRIB1 research aimed at exploring its roles in cancer, hyperlipidemia, and cardiovascular disease, and providing a theoretical basis for further studies on the biological roles of TRIB1.

Structure vs. Function of TRIB1-Myeloid Neoplasms and Beyond

The Tribbles family of proteins-comprising TRIB1, TRIB2, TRIB3 and more distantly related STK40-play important, but distinct, roles in differentiation, development and oncogenesis. Of the four Tribbles proteins, TRIB1 has been most well characterised structurally and plays roles in diverse cancer types. The most well-understood role of TRIB1 is in acute myeloid leukaemia, where it can regulate C/EBP transcription factors and kinase pathways. Structure-function studies have uncovered conformational switching of TRIB1 from an inactive to an active state when it binds to C/EBPα. This conformational switching is centred on the active site of TRIB1, which appears to be accessible to small-molecule inhibitors in spite of its inability to bind ATP. Beyond myeloid neoplasms, TRIB1 plays diverse roles in signalling pathways with well-established roles in tumour progression. Thus, TRIB1 can affect both development and chemoresistance in leukaemia; glioma; and breast, lung and prostate cancers. The pervasive roles of TRIB1 and other Tribbles proteins across breast, prostate, lung and other cancer types, combined with small-molecule susceptibility shown by mechanistic studies, suggests an exciting potential for Tribbles as direct targets of small molecules or biomarkers to predict treatment response.

Do TRIB1 and IL-9 Gene Polymorphisms Impact the Development and Manifestation of Pituitary Adenoma?

BACKGROUND/AIM

To evaluate the association between TRIB1(rs6987702) and IL-9(rs1859430, rs2069870) genotypes with the development and manifestation of pituitary adenoma (PA).

MATERIALS AND METHODS

The study group included 141 patients with PA and the control group consisted of 287 healthy people. The genotyping of rs6987702, rs1859430 and rs2069870 was carried out using a real-time polymerase chain reaction.

RESULTS

Statistically significant results were obtained regarding the rs1859430, but there were no significant results regarding rs6987702. We found that the rs1859430 A/A genotype increased the odds of having recurrent PA six times (p=0.006) under the co-dominant model and four times (p=0.021) under the recessive model. Furthermore, the analysis showed that the G/A genotype increased the odds of having recurrent PA 2.3 times (p=0.003) under the co-dominant model, while G/A and A/A genotypes increased the odds 2.7 times (p=0.011) under the over-dominant model.

CONCLUSION

Certain genotypes of rs1859430 can be associated with PA recurrence.

Tribbles Pseudokinases in Colorectal Cancer

The Tribbles family of pseudokinases controls a wide number of processes during cancer on-set and progression. However, the exact contribution of each of the three family members is still to be defined. Their function appears to be context-dependent as they can act as oncogenes or tumor suppressor genes. They act as scaffolds modulating the activity of several signaling pathways involved in different cellular processes. In this review, we discuss the state-of-knowledge for TRIB1, TRIB2 and TRIB3 in the development and progression of colorectal cancer. We take a perspective look at the role of Tribbles proteins as potential biomarkers and therapeutic targets. Specifically, we chronologically systematized all available articles since 2003 until 2020, for which Tribbles were associated with colorectal cancer human samples or cell lines. Herein, we discuss: (1) Tribbles amplification and overexpression; (2) the clinical significance of Tribbles overexpression; (3) upstream Tribbles gene and protein expression regulation; (4) Tribbles pharmacological modulation; (5) genetic modulation of Tribbles; and (6) downstream mechanisms regulated by Tribbles; establishing a comprehensive timeline, essential to better consolidate the current knowledge of Tribbles' role in colorectal cancer.

Intracellular Progesterone Receptor and cSrc Protein Working Together to Regulate the Activity of Proteins Involved in Migration and Invasion of Human Glioblastoma Cells

Glioblastomas are the most common and aggressive primary brain tumors in adults, and patients with glioblastoma have a median survival of 15 months. Some alternative therapies, such as Src family kinase inhibitors, have failed presumably because other signaling pathways compensate for their effects. In the last ten years, it has been proven that sex hormones such as progesterone (P4) can induce growth, migration, and invasion of glioblastoma cells through its intracellular progesterone receptor (PR), which is mostly known for its role as a transcription factor, but it can also induce non-genomic actions. These non-classic actions are, in part, a consequence of its interaction with cSrc, which plays a significant role in the progression of glioblastomas. We studied the relation between PR and cSrc, and its effects in human glioblastoma cells. Our results showed that P4 and R5020 (specific PR agonist) activated cSrc protein since both progestins increased the p-cSrc (Y416)/cSrc ratio in U251 and U87 human glioblastoma derived cell lines. When siRNA against the PR gene was used, the activation of cSrc by P4 was abolished. The co-immunoprecipitation assay showed that cSrc and PR interact in U251 cells. P4 treatment also promoted the increase in the p-Fak (Y397) (Y576/577)/Fak and the decrease in p-Paxillin (Y118)/Paxillin ratio, which are significant components of the focal adhesion complex and essential for migration and invasion processes. A siRNA against cSrc gene blocked the increase in the p-Fak (Y576/Y577)/Fak ratio and the migration induced by P4, but not the decrease in p-Paxillin (Y118)/Paxillin ratio. We analyzed the potential role of cSrc over PR phosphorylation in three databases, and one putative tyrosine residue in the amino acid 87 of PR was found. Our results showed that P4 induces the activation of cSrc protein through its PR. The latter and cSrc could interact in a bidirectional mode for regulating the activity of proteins involved in migration and invasion of glioblastomas.

Identification of 6 Hub Proteins and Protein Risk Signature of Colorectal Cancer

Background

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States and the third most common cancer globally. The incidence of CRC tends to be younger, and we urgently need a reliable prognostic assessment strategy.

Methods

Protein expression profile and clinical information of 390 CRC patients/samples were downloaded from the TCPA and TCGA database, respectively. The Kaplan-Meier, Cox regression, and Pearson correlation analysis were applied in this study.

Results

Based on the TCPA and TCGA database, we screened 6 hub proteins and first constructed protein risk signature, all of which were significantly associated with CRC patients' overall survival (OS). The risk score was an independent prognostic factor and significantly related with the size of the tumor in situ (T). 6 hub proteins were differentially expressed in cancer and normal tissues and in different CRC stages, which were validated at the ONCOMINE database. Next, 40 coexpressed proteins of 6 hub proteins were extracted from the TCPA database. In the protein-protein interaction (PPI) network, HER1, HER2, and CTNNB1 were at the center. Function enrichment analysis illustrated that 46 proteins were mainly involved in the EGFR (HER1) tyrosine kinase inhibitor resistance pathway.

Conclusion

Studies indicated that 6 hub proteins might be considered as new targets for CRC therapies, and the protein risk signature can be used to predict the OS of CRC patients.

Genomic and Functional Regulation of TRIB1 Contributes to Prostate Cancer Pathogenesis

Prostate cancer is the most frequent malignancy in European men and the second worldwide. One of the major oncogenic events in this disease includes amplification of the transcription factor cMYC. Amplification of this oncogene in chromosome 8q24 occurs concomitantly with the copy number increase in a subset of neighboring genes and regulatory elements, but their contribution to disease pathogenesis is poorly understood. Here we show that TRIB1 is among the most robustly upregulated coding genes within the 8q24 amplicon in prostate cancer. Moreover, we demonstrate that TRIB1 amplification and overexpression are frequent in this tumor type. Importantly, we find that, parallel to its amplification, TRIB1 transcription is controlled by cMYC. Mouse modeling and functional analysis revealed that aberrant TRIB1 expression is causal to prostate cancer pathogenesis. In sum, we provide unprecedented evidence for the regulation and function of TRIB1 in prostate cancer.

Targeting SRC Family Kinases in Mesothelioma: Time to Upgrade

Malignant mesothelioma (MM) is a deadly tumor mainly caused by exposure to asbestos. Unfortunately, no current treatment is able to change significantly the natural history of the disease, which has a poor prognosis in the majority of patients. The non-receptor tyrosine kinase SRC and other SRC family kinase (SFK) members are frequently hyperactivated in many cancer types, including MM. Several works have indeed suggested that SFKs underlie MM cell proliferation, survival, motility, and invasion, overall affecting multiple oncogenic pathways. Consistently, SFK inhibitors effectively counteracted MM cancerous features at the preclinical level. Dasatinib, a multi-kinase inhibitor targeting SFKs, was also assessed in clinical trials either as second-line treatment for patients with unresectable MM or, more recently, as a neoadjuvant agent in patients with resectable MM. Here, we provide an overview of the molecular mechanisms implicating SFKs in MM progression and discuss possible strategies for a more successful clinical application of SFK inhibitors. Our aim is to stimulate discussion and further consideration of these agents in better designed preclinical and clinical studies to make the most of another class of powerful antitumoral drugs, which too often are lost in translation when applied to MM.

Plastin 1 drives metastasis of colorectal cancer through the IQGAP1/Rac1/ERK pathway

Tumor metastasis is the dominant cause of death in colorectal cancer (CRC) patients, and it often involves dysregulation of various cytoskeletal proteins. Plastin 1 (PLS1) is an actin-bundling protein that has been implicated in the structure of intestinal epithelial microvilli; however, its role in CRC metastasis has not yet been determined. In this study, we demonstrated that PLS1 is highly expressed in 33.3% (45/135) of CRC patients and is correlated with lymph node metastasis and poor survival. In in vitro and in vivo experiments, PLS1 induced the migration and invasion of CRC cells and the metastases to the liver and lung in mice. Moreover, the expressions of key factors for CRC metastases, matrix metalloproteinase (MMP) 9 and 2, were enhanced by PLS1, which was dependent on phosphorylating ERK1/2 activated by IQGAP1/Rac1 signaling. The connection between these signals and PLS1 was further confirmed in CRC tissues of patients and the metastatic nodules from a mouse model. These findings suggest that PLS1 promotes CRC metastasis through the IQGAP1/Rac1/ERK pathway. Targeting PLS1 may provide a potential approach to inhibit the metastasis of CRC cells.

Src Family Kinases as Therapeutic Targets in Advanced Solid Tumors: What We Have Learned so Far

Src is the prototypal member of Src Family tyrosine Kinases (SFKs), a large non-receptor kinase class that controls multiple signaling pathways in animal cells. SFKs activation is necessary for the mitogenic signal from many growth factors, but also for the acquisition of migratory and invasive phenotype. Indeed, oncogenic activation of SFKs has been demonstrated to play an important role in solid cancers; promoting tumor growth and formation of distant metastases. Several drugs targeting SFKs have been developed and tested in preclinical models and many of them have successfully reached clinical use in hematologic cancers. Although in solid tumors SFKs inhibitors have consistently confirmed their ability in blocking cancer cell progression in several experimental models; their utilization in clinical trials has unveiled unexpected complications against an effective utilization in patients. In this review, we summarize basic molecular mechanisms involving SFKs in cancer spreading and metastasization; and discuss preclinical and clinical data highlighting the main challenges for their future application as therapeutic targets in solid cancer progression

SPARC Negatively Correlates With Prognosis After Transarterial Chemoembolization and Facilitates Proliferation and Metastasis of Hepatocellular Carcinoma via ERK/MMP Signaling Pathways

Background: Transarterial chemoembolization (TACE) represents a widely accepted treatment procedure for intermediate stage or unresectable hepatocellular carcinoma (HCC). However, few studies have evaluated serologic prognosis factors in patients with HCC before TACE. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycoprotein affecting tumorigenesis and metastasis, and leading to poor prognosis in HCC. Therefore, to further explore the potential prognosis value of SPARC, the expression levels in the plasma of patients and its potential molecular mechanisms underlying the regulation of HCC were investigated in this study. Materials and Methods: The study population included 43 patients with HCC who underwent TACE. To evaluate the expression of SPARC in different grades of pathological tissues, the immunohistochemistry was performed on tissues from 89 patients with HCC. Lentiviral vectors carrying interference sequences, as well as vectors harboring the complete open reading frame of SPARC for the knockdown or overexpression of SPARC in HuH-7 or HepG2 cells, respectively, allowed us to determine the biological functions of SPARC in vitro and in vivo. We also evaluated the levels of phosphorylated extracellular signal-regulated kinases 1/2 (p-ERK1/2) and matrix metalloproteinases 2/9 (MMP2/9) activation. Results: The association between serum levels of SPARC and the survival at different TNM and Barcelona-Clinic Liver Cancer (BCLC) stages in patients with HCC undergoing TACE were evaluated. We observed a significant upregulation of SPARC in high grade HCC tissues, predicting unfavorable prognosis, and suggesting an important tumor-promoting effect of SPARC. Functional studies indicated that downregulation of SPARC contributed to the inhibition of proliferation and metastasis of HuH-7 cells in vitro, whereas its overexpression led to opposite phenotypes. Mechanistically, decreased expression of SPARC resulted in dephosphorylation of ERK1/2 and deactivation of MMP2/9, thereby inhibiting growth and metastasis of HCC. Importantly, low expression levels of SPARC inhibited the formation of subcutaneous tumors in nude mice. Conclusions: SPARC was found to facilitate proliferation and metastasis of HCC via modulation of the ERK1/2-MMP2/9 signaling pathways. Our research has provided a glimpse on the biological mechanism of SPARC and might contribute to the eventual treatment of liver cancer.

Screening and identification of key biomarkers in prostate cancer using bioinformatics

Prostate cancer (PCa) is the second most common cancer amongst males worldwide. In the current study, microarray datasets GSE3325 and GSE6919 from the Gene Expression Omnibus database were screened to identify candidate genes that are associated with the progression of PCa. A total of 273 differentially expressed genes (DEGs) were identified, which included 173 downregulated genes and 100 upregulated genes, and a protein-protein interaction network was constructed using Search Tool for the Retired of Interacting Genes. The enriched functions and pathways of the identified DEGs included cell adhesion, the negative regulation of cell proliferation, protein binding and focal adhesion. A total of 8 hub genes were identified, of which PDZ binding kinase, Krüppel-like factor 4, collagen type XII α-1 chain, RAP1A and RAP39B were indicated to be associated with the progression and recurrence of PCa. In conclusion, the DEGs and hub genes identified in the present study may aid in determining the molecular mechanisms associated with PCa carcinogenesis and progression.

Pseudokinases: a tribble-edged sword

Advances in the understanding of the Tribbles family of pseudokinases (TRIB1, TRIB2 and TRIB3) reveal these proteins as potentially valuable biomarkers of disease diagnosis, prognosis, prediction and clinical strategy. In their role as signalling mediators and scaffolding proteins, TRIBs lead to changes in protein stability and activity, which impact on diverse cellular processes such as proliferation, differentiation, cell cycle and cell death. We review the role of TRIB proteins as promising therapeutic targets, with an emphasis on their role in cancer, and as biomarkers, with potential application across diverse pathological processes.

MicroRNA 452 Regulates Cell Proliferation, Cell Migration, and Angiogenesis in Colorectal Cancer by Suppressing VEGFA Expression

The human microRNA 452 (MIR452) was identified as a colorectal cancer (CRC)-associated micro RNA (miRNA) by miRNA expression profiling of human CRC tissues versus normal colorectal tissues. It was significantly up-regulated in human CRC tissues. However, the functional mechanisms of MIR452 and its target genes in CRC remain unclear. We identified 27 putative MIR452 target genes, and found that the vascular endothelial growth factor A (VEGFA) was a direct target gene of MIR452. Both cellular and extracellular VEGFA levels were significantly downregulated in CRC cells upon their transfection with MIR452 or siVEGFA. VEGFA expression was frequently downregulated in human CRC tissues in comparison with that in their healthy counterparts. We showed that MIR452 regulated the expression of genes in the VEGFA-mediated signal transduction pathways vascular endothelial growth factor receptor 1 (VEGFR2)-mitogen-activated protein kinase (MAPK) and VEGFR2-SRC proto-oncogene non-receptor tyrosine kinase (SRC) in CRC cells. Immunohistological analyses of xenografted MIR452-overexpressing CRC cells in mice showed that MIR452 regulated cell proliferation and angiogenesis. Furthermore, aortic ring angiogenesis assay in rats clearly showed that the number of microvessels formed was significantly reduced by MIR452 transfection. Our findings suggest that MIR452 regulates cell proliferation, cell migration, and angiogenesis by suppressing VEGFA expression in early CRC progression; therefore, MIR452 may have therapeutic value in relation to human CRC.

Leptin Promotes Expression of EMT-Related Transcription Factors and Invasion in a Src and FAK-Dependent Pathway in MCF10A Mammary Epithelial Cells

Leptin is one of the main adipokines secreted in breast tissue. Leptin promotes epithelial-mesenchymal transition (EMT), cell migration and invasion in epithelial breast cells, leading to tumor progression. Although, the molecular mechanisms that underlie these events are not fully understood, the activation of different signaling pathways appears to be essential. In this sense, the effects of leptin on the activation of kinases like Src and FAK, which regulate signaling pathways that activate the EMT program, are not completely described. Therefore, we investigated the involvement of these kinases using an in vitro model for leptin-induced EMT process in the non-tumorigenic MCF10A cell line. To this end, MCF10A cells were stimulated with leptin, and Src and FAK activation was assessed. Specific events occurring during EMT were also evaluated in the presence or absence of the kinases' chemical inhibitors PP2 and PF-573228. For instance, we tested the expression and subcellular localization of the EMT-related transcription factors Twist and β-catenin, by western blot and immunofluorescence. We also evaluated the secretion and activation of matrix metalloproteases (MMP-2 and MMP-9) by gelatin zymography. Invasiveness properties of leptin-stimulated cells were determined by invadopodia formation assays, and by the Transwell chamber method. Our results showed that leptin promotes EMT through Src and FAK activation, which leads to the secretion and activation of MMP-2 and MMP-9, invadopodia formation and cell invasion in MCF10A cells. In conclusion, our data suggest that leptin promotes an increase in the expression levels of Twist and β-catenin, the secretion of MMP-2, MMP-9, the invadopodia formation and invasion in MCF10A cells in a Src and FAK-dependent manner.

Ginkgo Biloba Extract Inhibits Metastasis and ERK/Nuclear Factor kappa B (NF-κB) Signaling Pathway in Gastric Cancer

Background

Ginkgo biloba extract (EGb761), a standard extract of the Chinese traditional medicine Ginkgo biloba, plays an anti-tumor role in various cancers. However, whether EGb761 is involved in the invasion and metastasis of gastric cancer remains unclear.

Material/Methods

In the current study, cell viability assay, Western blotting, wound-healing assay, Transwell invasion assay, and orthotopic transplantation model were performed to explore the effects of EGb761 on gastric cancer.

Results

In vitro, the results showed that EGb761 suppressed the proliferation of gastric cancer cells in a dose-dependent manner. Furthermore, the migration and invasiveness were weakened and the protein levels of p-ERK1/2, NF-κB P65, NF-κB p-P65, and MMP2 were decreased by EGb761 or U0126 (an inhibitor of ERK signaling pathway) exposure in gastric cancer cells. Moreover, the combined treatment with EGb761 and U0126 significantly inhibited ERK, NF-κB signaling pathway, and the expression of MMP2 than those of single drug. In vivo, EGb761 inhibited the tumor growth and hepatic metastasis of gastric cancer in the mouse model. Results of immunohistochemistry indicated that the expression of ERK1/2, NF-κB P65 and MMP2 were decreased by EGb761 in the tumor tissues.

Conclusions

EGb761 plays a vital role in the suppression of metastasis and ERK/NF-κB signaling pathway in gastric cancer.

Reduction of inflammation and colon injury by a Pennyroyal phenolic extract in experimental inflammatory bowel disease in mice

PURPOSE

Little is known about the pharmacological effects of the phenolic compounds of Pennyroyal (Mentha pulegium). This Mediterranean aromatic plant, used as a gastronomic spice and as food preservative by the food industry has been studied mainly due to its essential oil antibacterial properties, composed primarily by monoterpenes. With this work, we aimed to evaluate the effects of a phenolic extract of pennyroyal in the impairment of inflammatory processes in Inflammatory Bowel Diseases (IBD) and in the potential inhibition of progression to colorectal cancer (CRC).

METHODS

To that purpose, we evaluated the effect of pennyroyal extract administration in a model of TNBS-induced colitis in mice and further determined its effect on human colon carcinoma cell proliferation and invasion.

RESULTS

The phenolic extract of pennyroyal exhibited antioxidant properties in in vitro assays and administration of the extract in a rat model of carrageenan-induced paw oedema led to significant anti-inflammatory effects. Further results evidenced a beneficial effect of the phenolic extract in the attenuation of experimental colitis and a potential antiproliferative effect on cultured colon cancer cells, effects not previously described, to our knowledge. A reduction in several markers of colon inflammation was observed following administration of the extract to colitis-induced mice, including functional and histological indicators. A successful inhibition of cancer cell invasion and proliferation was also observed in in vitro studies with HT-29 cells. Furthermore, the extract also led to a reduced expression of iNOS/COX-2 in the colon of colitis-induced mice, both being crucial mediators of intestinal inflammation.

CONCLUSIONS

Taking into consideration the central role of inflammation in the pathophysiology of CRC and the recognised connection between inflammatory events and cancer, these results enlighten the relevance of the phenolic constituents of pennyroyal as important pharmacological sources in the investigation of new treatment options for patients with inflammatory bowel diseases.

CXCL1 stimulates migration and invasion in ER‑negative breast cancer cells via activation of the ERK/MMP2/9 signaling axis

Chemokine (C‑X‑C motif) ligand 1 (CXCL1), a member of the CXC chemokine family, has been reported to be a critical factor in inflammatory diseases and tumor progression; however, its functions and molecular mechanisms in estrogen receptor α (ER)‑negative breast cancer (BC) remain largely unknown. The present study demonstrated that CXCL1 was upregulated in ER‑negative BC tissues and cell lines compared with ER‑positive tissues and cell lines. Treatment with recombinant human CXCL1 protein promoted ER‑negative BC cell migration and invasion in a dose‑dependent manner, and stimulated the activation of phosphorylated (p)‑ extracellular signal‑regulated kinase (ERK)1/2, but not p‑STAT3 or p‑AKT. Conversely, knockdown of CXCL1 in BC cells attenuated these effects. Additionally, CXCL1 increased the expression of matrix metalloproteinase (MMP)2/9 via the ERK1/2 pathway. Inhibition of MEK1/2 by its antagonist U0126 reversed the effects of CXCL1 on MMP2/9 expression. Furthermore, immunohistochemical analysis revealed a strong positive association between CXCL1 and p‑ERK1/2 expression levels in BC tissues. In conclusion, the present study demonstrated that CXCL1 is highly expressed in ER‑negative BC, and stimulates BC cell migration and invasion via the ERK/MMP2/9 pathway. Therefore, CXCL1 may serve as a potential therapeutic target in ER‑negative BC.

Implication for Cancer Stem Cells in Solid Cancer Chemo-Resistance: Promising Therapeutic Strategies Based on the Use of HDAC Inhibitors

Resistance to therapy in patients with solid cancers represents a daunting challenge that must be addressed. Indeed, current strategies are still not effective in the majority of patients; which has resulted in the need for novel therapeutic approaches. Cancer stem cells (CSCs), a subset of tumor cells that possess self-renewal and multilineage differentiation potential, are known to be intrinsically resistant to anticancer treatments. In this review, we analyzed the implications for CSCs in drug resistance and described that multiple alterations in morphogenetic pathways (i.e., Hippo, Wnt, JAK/STAT, TGF-β, Notch, Hedgehog pathways) were suggested to be critical for CSC plasticity. By interrogating The Cancer Genome Atlas (TCGA) datasets, we first analyzed the prevalence of morphogenetic pathways alterations in solid tumors with associated outcomes. Then, by highlighting epigenetic relevance in CSC development and maintenance, we selected histone deacetylase inhibitors (HDACi) as potential agents of interest to target this subpopulation based on the pleiotropic effects exerted specifically on altered morphogenetic pathways. In detail, we highlighted the role of HDACi in solid cancers and, specifically, in the CSC subpopulation and we pointed out some mechanisms by which HDACi are able to overcome drug resistance and to modulate stemness. Although, further clinical and preclinical investigations should be conducted to disclose the unclear mechanisms by which HDACi modulate several signaling pathways in different tumors. To date, several lines of evidence support the testing of novel combinatorial therapeutic strategies based on the combination of drugs commonly used in clinical practice and HDACi to improve therapeutic efficacy in solid cancer patients.

Ubiquitous and cell type-specific transcriptomic changes triggered by dissipation of monovalent cation gradients in rodent cells: Physiological and pathophysiological implications

Elevation of [Na⁺]_i/[K⁺]_i-ratio is considered as one of the major signals triggering transcriptomic changes in various cells types. In this study, we identified ubiquitous and cell type-specific [Formula: see text] -sensitive genes by comparative analysis of transcriptomic changes in ouabain-treated rat aorta smooth muscle cells and rat aorta endothelial cells (RASMC and RAEC, respectively), rat cerebellar granule cells (RCGC), and mouse C2C12 myoblasts. Exposure of the cells to ouabain increased intracellular Na⁺ content by ~14, 8, 7, and 6-fold and resulted in appearance of 7577, 2698, 2120, and 1146 differentially expressed transcripts in RAEC, RASMC, C2C12, and RCGC, respectively. Eighty-three genes were found as the intersection of the four sets of identified transcripts corresponding to each cell type and are classified as ubiquitous. Among the 10 top upregulated ubiquitous transcripts are the following: Dusp6, Plk3, Trib1, Ccl7, Mafk, Atf3, Ptgs2, Cxcl1, Spry4, and Coq10b. Unique transcripts whose expression is cell-specific include 4897, 1523, 789, and 494 transcripts for RAEC, RASMC, C2C12, and RCGC, respectively. The role of gene expression and signal pathways induced by dissipation of transmembrane gradient of monovalent cations in the development of various diseases is discussed with special attention to cardiovascular and pulmonary illnesses.

A comprehensive study of immunology repertoires in both preoperative stage and postoperative stage in patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the 3rd most common cancer type in the world. The correlation between immune repertoire and prognosis of CRC has been well studied in the last decades. The diversity and stability of the immune cells can be measured by hypervariable complementarity-determining region 3 (CDR3) segments of the T-cell receptor (TCR).

METHODS

In this study, we collected five healthy controls and 19 CRC patients' peripheral blood mononuclear cells (PBMCs) in three stages, namely 1 day preoperative, 3 days' postoperative, and 7 days' postoperative, respectively. Simultaneously, we have also done the comparative analysis of these two different anesthesia methods, namely TIVA and CEGA. Sequencing of the TCR segments has been performed by multiplex PCR and high-throughput next-generation sequencing. We also analyzed the distribution of CDR3 length, highly expansion clones (HECs), TRBV, and TRBJ gene usage.

RESULTS

Our result showed a significant difference between TCR CDR3 length distribution and HEC distribution between CRC patients and healthy controls. We also found that TRBV11-2, TRBV12-1, TRBV16, TRBV3-2, TRBV4-2, TRBV4-3, TRBV5-4, TRBV6-8, TRBV7-8, TRBV7-9 and RBV11-2, TRBV12-1, TRBV16, TRBV3-2, TRBV4-2, TRBV4-3, TRBV5-4, TRBV6-8, TRBV7-8, and TRBV7-9 usages are different between CRC patients and healthy controls.

CONCLUSION

In conclusion, CRC patients were presented with different immune repertoire in comparison with healthy controls. In this study, significant difference in TRBV and TRBJ gene usage in between case and control group could provide some potential biomarker for the diagnosis and the treatment of the patients with CRC.

Synergistic anticancer effects of timosaponin AIII and ginsenosides in MG63 human osteosarcoma cells

Background

Timosaponin AIII (TA3) is a steroidal saponin extracted from Anemarrhena asphodeloides. Here, we investigated the anticancer effects of TA3 in MG63 human osteosarcoma cells. TA3 attenuates migration and invasion of MG63 cells via regulations of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are involved with cancer metastasis in various cancer cells. TA3 reduced enzymatic activities and transcriptional expressions of MMP-2 and MMP-9 in MG63 cells. TA3 also inhibited Src, focal adhesion kinase, extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), p38, β-catenin, and cAMP response element binding signaling, which regulate migration and invasion of cells. TA3 induced apoptosis of MG63 cells via regulations of caspase-3, caspase-7, and poly(ADP-ribose) polymerase (PARP). Then, we tested several ginsenosides to be used in combination with TA3 for the synergistic anticancer effects. We found that ginsenosides Rb1 and Rc have synergistic effects on TA3-induced apoptosis in MG63 cells.

Methods

We investigated the anticancer effects of TA3 and synergistic effects of various ginseng saponins on TA3-induced apoptosis in MG63 cells. To test antimetastatic effects, we performed wound healing migration assay, Boyden chamber invasion assays, gelatin zymography assay, and Western blot analysis. Annexin V/PI staining apoptosis assay was performed to determine the apoptotic effect of TA3 and ginsenosides.

Results

TA3 attenuated migration and invasion of MG63 cells and induced apoptosis of MG63 cells. Ginsenosides Rb1 and Rc showed the synergistic effects on TA3-induced apoptosis in MG63 cells.

Conclusions

The results strongly suggest that the combination of TA3 and the two ginsenosides Rb1 and Rc may be a strong candidate for the effective antiosteosarcoma agent.

Adaptively capturing the heterogeneity of expression for cancer biomarker identification

Background

Identifying cancer biomarkers from transcriptomics data is of importance to cancer research. However, transcriptomics data are often complex and heterogeneous, which complicates the identification of cancer biomarkers in practice. Currently, the heterogeneity still remains a challenge for detecting subtle but consistent changes of gene expression in cancer cells.

Results

In this paper, we propose to adaptively capture the heterogeneity of expression across samples in a gene regulation space instead of in a gene expression space. Specifically, we transform gene expression profiles into gene regulation profiles and mathematically formulate gene regulation probabilities (GRPs)-based statistics for characterizing differential expression of genes between tumor and normal tissues. Finally, an unbiased estimator (aGRP) of GRPs is devised that can interrogate and adaptively capture the heterogeneity of gene expression. We also derived an asymptotical significance analysis procedure for the new statistic. Since no parameter needs to be preset, aGRP is easy and friendly to use for researchers without computer programming background. We evaluated the proposed method on both simulated data and real-world data and compared with previous methods. Experimental results demonstrated the superior performance of the proposed method in exploring the heterogeneity of expression for capturing subtle but consistent alterations of gene expression in cancer.

Conclusions

Expression heterogeneity largely influences the performance of cancer biomarker identification from transcriptomics data. Models are needed that efficiently deal with the expression heterogeneity. The proposed method can be a standalone tool due to its capacity of adaptively capturing the sample heterogeneity and the simplicity in use.

Software availability

The source code of aGRP can be downloaded from https://github.com/hqwang126/aGRP.

Electronic supplementary material

The online version of this article (10.1186/s12859-018-2437-2) contains supplementary material, which is available to authorized users.

Association Analysis of a Microsatellite Repeat in the TRIB1 Gene With Prostate Cancer Risk, Aggressiveness and Survival

With an estimated 1.1 million men worldwide diagnosed with prostate cancer yearly, effective and more specific biomarkers for early diagnosis could lead to better patient outcome. As such, novel genetic markers are sought for this purpose. The tribbles homologue 1 gene (TRIB1) has recently shown to have a role in prostate tumorigenesis and data-mining of prostate cancer expression data confirmed clinical significance of TRIB1 in prostate cancer. For the first time, a polymorphic microsatellite in this gene was studied for its potential association with prostate cancer risk and aggressiveness. Genomic DNA was extracted from a cohort of 1,152 prostate cancer patients and 1,196 cancer-free controls and the TTTTG-TRIB1 microsatellite was genotyped. The socio-demographic and clinical characteristics were analyzed using the non-parametric t-test and two-way ANOVA. Association of the TTTTG-TRIB1 microsatellite and prostate cancer risk and aggressiveness were analyzed by binary logistic regression and confirmed by bootstrapping. Total and prostate cancer mortality was analyzed using the Kaplan Meier test. Genotype and allele correlation with TRIB1 mRNA levels was analyzed using the non-parametric Kolmogorov-Smirnov test. To predict the effect that the TTTTG-TRIB1 polymorphisms had on the mRNA structure, the in silico RNA folding predictor tool, mfold, was used. By analyzing the publicly available data, we confirmed a significant over-expression of TRIB1 in prostate cancer compared to other cancer types, and an over-expression in prostate cancerous tissue compared to adjacent benign. Three alleles (three-five repeats) were observed for TTTTG-TRIB1. The three-repeat allele was associated with prostate cancer risk at the allele (OR = 1.16; P = 0.044) and genotypic levels (OR = 1.70; P = 0.006) and this association was age-independent. The four-repeat allele was inversely associated with prosatet cancer risk (OR = 0.57; P < 0.0001). TRIB1 expression was upregulated in tumors when compared to adjacent cancer-free tissue but was not allele specific. In silico analysis suggested that the TTTTG-TRIB1 alleles may alter TRIB1 mRNA structure. In summary, the three-repeat allele was significantly associated with prostate cancer risk, suggesting a biomarker potential for this microsatellite to predict prostate cancer. Further studies are needed to elucidate the functional role of this microsatellite in regulating TRIB1 expression, perhaps by affecting the TRIB1 mRNA structure and stability.

Na/K-ATPase Y260 Phosphorylation-mediated Src Regulation in Control of Aerobic Glycolysis and Tumor Growth

We report here the identification of α1 Na/K-ATPase as a major regulator of the proto-oncogene Src kinase and the role of this regulation in control of Warburg effect and tumor growth. Specifically, we discovered Y260 in α1 Na/K-ATPase as a Src-specific phosphorylation and binding site and that Y260 phosphorylation is required for Src-mediated signal transduction in response to a number of stimuli including EGF. As such, it enables a dynamic control of aerobic glycolysis. However, such regulation appears to be lost or attenuated in human cancers as the expression of Na/K-ATPase α1 was significantly decreased in prostate, breast and kidney cancers, and further reduced in corresponding metastatic lesions in patient samples. Consistently, knockdown of α1 Na/K-ATPase led to a further increase in lactate production and the growth of tumor xenograft. These findings suggest that α1 Na/K-ATPase works as a tumor suppressor and that a loss of Na/K-ATPase-mediated Src regulation may lead to Warburg phenotype in cancer.

Dioscin Inhibits HSC-T6 Cell Migration via Adjusting SDC-4 Expression: Insights from iTRAQ-Based Quantitative Proteomics

Hepatic stellate cells (HSCs) migration, an important bioprocess, contributes to the development of liver fibrosis. Our previous studies have found the potent activity of dioscin against liver fibrosis by inhibiting HSCs proliferation, triggering the senescence and inducing apoptosis of activated HSCs, but the molecular mechanisms associated with cell migration were not clarified. In this work, iTRAQ (isobaric tags for relative and absolution quantitation)-based quantitative proteomics study was carried out, and a total of 1566 differentially expressed proteins with fold change ≥2.0 and p < 0.05 were identified in HSC-T6 cells treated by dioscin (5.0 μg/mL). Based on Gene Ontology classification, String and KEGG pathway assays, the effects of dioscin to inhibit cell migration via regulating SDC-4 were carried out. The results of wound-healing, cell migration and western blotting assays indicated that dioscin significantly inhibit HSC-T6 cell migration through SDC-4-dependent signal pathway by affecting the expression levels of Fn, PKCα, Src, FAK, and ERK1/2. Specific SDC-4 knockdown by shRNA also blocked HSC-T6 cell migration, and dioscin slightly enhanced the inhibiting effect. Taken together, the present work showed that SDC-4 played a crucial role on HSC-T6 cell adhesion and migration of dioscin against liver fibrosis, which may be one potent therapeutic target for fibrotic diseases.