YB-1 promotes transcription of cyclin D1 in human non-small-cell lung cancers

YBX1: A Multifunctional Protein in Senescence and Immune Regulation

The Y-box binding protein 1 (YBX1) is a multifunctional protein with a wide range of roles in cell biology. It plays a crucial role in immune modulation, senescence, and disease progression. This review presents a comprehensive analysis of the specific functions and mechanisms of YBX1 in these areas. Initially, YBX1 is shown to be closely associated with cellular senescence and impacts significant biological processes, including cell proliferation, damage repair, and metabolism. This suggests potential applications in the prevention and treatment of senescence-related diseases. Additionally, YBX1 regulates the immune response by controlling the function of immune cells and the expression of immune molecules. It is essential in maintaining immune system homeostasis and impacts the pathological process of various diseases, including tumors. Lastly, the diverse functions of the YBX1 protein make it a promising candidate for the development of innovative therapeutic strategies for diseases. Comprehensive research on its mechanisms could provide novel insights and approaches for the prevention, diagnosis, and treatment of related diseases.

Oncogenic accumulation of cysteine promotes cancer cell proliferation by regulating the translation of D-type cyclins

Malignant cells exhibit a high demand for amino acids to sustain their abnormal proliferation. Particularly, the intracellular accumulation of cysteine is often observed in cancer cells. Previous studies have shown that deprivation of intracellular cysteine in cancer cells results in the accumulation of lipid peroxides in the plasma membrane and induction of ferroptotic cell death, indicating that cysteine plays a critical role in the suppression of ferroptosis. Herein, we found that the oncogenic accumulation of cysteine also contributes to cancer cell proliferation by promoting the cell cycle progression, which is independent of its suppressive effect on ferroptosis. The growth ability of four types of cancer cells, including murine hepatocarcinoma cells, but not of primary hepatocytes, were dependent on the exogenous supply of cysteine. Deprivation of intracellular cysteine in cancer cells induced cell cycle arrest at the G0/G1 phase, accompanied by a decrease in the expression of cyclin D1 and D2 proteins. The cysteine deprivation-induced decrease in D-type cyclin expression was associated with the upregulation of eukaryotic translation initiation factor 4E binding protein 1, which represses the translation of cyclin D1 and D2 proteins by binding to eukaryotic translation initiation factor 4E. Similar results were observed in hepatocarcinoma cells treated with erastin, an inhibitor of cystine/glutamate antiporter, xCT. These findings reveal an unappreciated role of cysteine in regulating the growth of malignant cancer cells and deepen our understanding of the cytotoxic effect of xCT inhibitor to prevent cancer cell proliferation.

Y-box binding protein 1/cyclin A1 axis specifically promotes cell cycle progression at G2/M phase in ovarian cancer

Y-box binding protein 1 (YBX1) promotes oncogenic transformation and tumor growth. YBX1 plays a role in regulation of cell cycle promotion via upregulation of cell cycle-related genes. In ovarian cancer, YBX1 also promotes tumor growth, but the mechanisms of YBX1 in cell growth and cell cycle in ovarian cancer remain not to be fully understood. Here, we investigated whether YBX1-dependent cancer cell proliferation was specifically associated with expression of cell cycle related genes in ovarian cancer. Protein and mRNA expression levels of YBX1 and cell cycle-related genes in ovarian cancer cell lines and tissues were determined by western blot analysis, immunohistochemical analysis and reverse transcription-quantitative PCR. Cell cycle analysis was performed by flow cytometry. Luciferase assay and Chromatin immunoprecipitation assay were used to investigate a transcriptional function of YBX1. YBX1 silencing induced marked growth suppression in 4 cell lines (group A), moderate suppression in 5 cell lines (group B), and no suppression in 3 cell lines (group C) among 12 ovarian cancer cell lines in culture. The YBX1 silencing induced cell cycle arrest at G2/M phase and suppressed expression of cyclin A1 gene in group A and B cell lines, but not in group C cell lines. Cyclin A1 silencing specifically suppressed cell proliferation in group A cell lines and partially in group B cell lines, but not at all in group C cell lines. YBX1 mRNA levels were significantly correlated with cyclin A1 mRNA levels in patients with high-grade serous carcinoma. Augmented YBX1 expression plays a key role in tumor growth promotion in ovarian cancer in its close association with cyclin A1.

The deubiquitinase USP5 promotes cholangiocarcinoma progression by stabilizing YBX1

AIMS

Ubiquitin specific peptidase 5 (USP5), a member of deubiquitinating enzymes, has garnered significant attention for its crucial role in cancer progression. This study aims to explore the role of USP5 and its potential molecular mechanisms in cholangiocarcinoma (CCA).

MAIN METHODS

To explore the effect of USP5 on CCA, gain-of-function and loss-of-function assays were conducted in human CCA cell lines RBE and HCCC9810. The CCK8, colony-forming assay, EDU, flow cytometry, transwell assay and xenografts were used to assess cell proliferation, migration and tumorigenesis. Western blot and immunohistochemistry were performed to measure the expression of related proteins. Immunoprecipitation and immunofluorescence were applied to identify the interaction between USP5 and Y box-binding protein 1 (YBX1). Ubiquitination assays and cycloheximide chase assays were carried out to confirm the effect of USP5 on YBX1.

KEY FINDINGS

We found USP5 is highly expressed in CCA tissues, and upregulated USP5 is required for the cancer progression. Knockdown of USP5 inhibited cell proliferation, migration and epithelial-mesenchymal transition (EMT) in vitro, along with suppressed xenograft tumor growth and metastasis in vivo. Mechanistically, USP5 could interact with YBX1 and stabilize YBX1 by deubiquitination in CCA cells. Additionally, silencing of USP5 hindered the phosphorylation of YBX1 at serine 102 and its subsequent translocation to the nucleus. Notably, the effect induced by USP5 overexpression in CCA cells was reversed by YBX1 silencing.

SIGNIFICANCE

Our findings reveal that USP5 is required for cell proliferation, migration and EMT in CCA by stabilizing YBX1, suggesting USP5-YBX1 axis as a promising therapeutic target for CCA.

Helminth-derived molecules improve 5-fluorouracil treatment on experimental colon tumorigenesis

Colorectal cancer (CRC) is one of the most prevalent fatal neoplasias worldwide. Despite efforts to improve the early diagnosis of CRC, the mortality rate of patients is still nearly 50%. The primary treatment strategy for CRC is surgery, which may be accompanied by chemotherapy and radiotherapy. The conventional and first-line chemotherapeutic agent utilized is 5-fluorouracil (5FU). However, it has low efficiency. Combination treatment with leucovorin and oxaliplatin or irinotecan improves the effectiveness of 5FU therapy. Unfortunately, most patients develop drug resistance, leading to disease progression. Here, we evaluated the effect of a potential alternative adjuvant treatment for 5FU, helminth-derived Taenia crassiceps (TcES) molecules, on treating advanced colitis-associated colon cancer. The use of TcES enhanced the effects of 5FU on established colonic tumors by downregulating the expression of the immunoregulatory cytokines, Il-10 and Tgf-β, and proinflammatory cytokines, Tnf-α and Il-17a, and reducing the levels of molecular markers associated with malignancy, cyclin D1, and Ki67, both involved in apoptosis inhibition and the signaling pathway of β-catenin. TcES+5FU therapy promoted NK cell recruitment and the release of Granzyme B1 at the tumor site, consequently inducing tumor cell death. Additionally, it restored P53 activity which relates to decreased Mdm2 expression. In vitro assays with human colon cancer cell lines showed that therapy with TcES+5FU significantly reduced cell proliferation and migration by modulating the P53 and P21 signaling pathways. Our findings demonstrate, for the first time in vivo, that helminth-derived excreted/secreted products may potentiate the effect of 5FU on established colon tumors.

One-Shot Single-Cell Proteome and Metabolome Analysis Strategy for the Same Single Cell

Characterizing the profiles of proteome and metabolome at the single-cell level is of great significance in single-cell multiomic studies. Herein, we proposed a novel strategy called one-shot single-cell proteome and metabolome analysis (scPMA) to acquire the proteome and metabolome information in a single-cell individual in one injection of LC-MS/MS analysis. Based on the scPMA strategy, a total workflow was developed to achieve the single-cell capture, nanoliter-scale sample pretreatment, one-shot LC injection and separation of the enzyme-digested peptides and metabolites, and dual-zone MS/MS detection for proteome and metabolome profiling. Benefiting from the scPMA strategy, we realized dual-omic analysis of single tumor cells, including A549, HeLa, and HepG2 cells with 816, 578, and 293 protein groups and 72, 91, and 148 metabolites quantified on average. A single-cell perspective experiment for investigating the doxorubicin-induced antitumor effects in both the proteome and metabolome aspects was also performed.

Y-Box Binding Protein 1: Unraveling the Multifaceted Role in Cancer Development and Therapeutic Potential

Y-box binding protein 1 (YBX1), a member of the Cold Shock Domain protein family, is overexpressed in various human cancers and is recognized as an oncogenic gene associated with poor prognosis. YBX1's functional diversity arises from its capacity to interact with a broad range of DNA and RNA molecules, implicating its involvement in diverse cellular processes. Independent investigations have unveiled specific facets of YBX1's contribution to cancer development. This comprehensive review elucidates YBX1's multifaceted role in cancer across cancer hallmarks, both in cancer cell itself and the tumor microenvironment. Based on this, we proposed YBX1 as a potential target for cancer treatment. Notably, ongoing clinical trials addressing YBX1 as a target in breast cancer and lung cancer have showcased its promise for cancer therapy. The ramp up in in vitro research on targeting YBX1 compounds also underscores its growing appeal. Moreover, the emerging role of YBX1 as a neural input is also proposed where the high level of YBX1 was strongly associated with nerve cancer and neurodegenerative diseases. This review also summarized the up-to-date advanced research on the involvement of YBX1 in pancreatic cancer.

YBX1 as an oncogenic factor in T-cell acute lymphoblastic leukemia

Y-box-binding protein 1 (YBX1), a member of the RNA-binding protein family, is a critical regulator of cell survival in various solid tumors and acute myeloid leukemia. However, the function of YBX1 in T-cell acute lymphoblastic leukemia (T-ALL) remains elusive. Here, we found that YBX1 was upregulated in patients with T-ALL, T-ALL cell lines, and NOTCH1-induced T-ALL mice. Furthermore, depletion of YBX1 dramatically reduced cell proliferation, induced cell apoptosis, and induced G0/G1 phase arrest in vitro. Moreover, YBX1 depletion significantly decreased the leukemia burden in the human T-ALL xenograft and NOTCH1-induced T-ALL mice model in vivo. Mechanistically, downregulation of YBX1 markedly inhibited the expression of total AKT serine/threonine kinase (AKT), p-AKT, total extracellular signal-regulated kinase (ERK), and p-ERK in T-ALL cells. Taken together, our results uncovered a critical role of YBX1 in the leukemogenesis of T-ALL, which may have great potential as a biomarker and therapeutic target in T-ALL.

Effect of isolated grandivittin from Ferulago trifida Boiss. (Apiaceae) on the proliferation and apoptosis of human lung cancer A549 cells

Lung cancer is one of the deadliest cancers in the world. Introducing new promising agents can help the chemotherapeutic management of cancer. In the knowledge of oncology, plants are of special interest as a rich source of new antineoplastic and chemotherapeutic agents. Grandivittin (GRA) is one of the main constituents of Ferulago trifida Boiss. with established medicinal, phytochemical, and pharmacological properties. This study aimed to isolate and evaluate the antineoplastic potential of grandivittin and its underlying mechanisms in human lung cancer A549 cells. The viability of the A549 cells after being treated with 0.1, 0.4, 0.7, 1, and 1.3 mM of GRA for three following days was measured using the MTT method. The early apoptosis and late apoptosis were assessed by fluorescence-activated cell sorter analysis through annexin V/PI staining. The expression of apoptotic agents' genes (caspase 3, caspase 9, Bcl2, Bax, and P53) was evaluated by the RT-PCR method. GRA increased apoptotic cells and decreased cell viability in a dose- and time-dependent manner, in which only 50% of cells survived at a dose of 0.7 mM. The expression of Bax, P53, caspase 3, and caspase 9 genes in the A549 cells was significantly upregulated after GRA treatment compared to control cells (P < 0.05). On the other hand, Bcl2 was significantly downregulated after GRA treatment (P < 0.05). The results indicated that GRA can activate cell death in A549 lung carcinoma cells by inducing both DNA toxicity p53 and cascade-dependent pathways. Therefore, GRA may be a potential new therapeutic agent for the treatment of lung cancer.

YB-1 is a positive regulator of KLF5 transcription factor in basal-like breast cancer

Y-box binding protein 1 (YB-1) is a well-known oncogene highly expressed in various cancers, including basal-like breast cancer (BLBC). Beyond its role as a transcription factor, YB-1 is newly defined as an epigenetic regulator involving RNA 5-methylcytosine. However, its specific targets and pro-cancer functions are poorly defined. Here, based on clinical database, we demonstrate a positive correlation between Kruppel-like factor 5 (KLF5) and YB-1 expression in breast cancer patients, but a negative correlation with that of Dachshund homolog 1 (DACH1). Mechanistically, YB-1 enhances KLF5 expression not only through transcriptional activation that can be inhibited by DACH1, but also by stabilizing KLF5 mRNA in a RNA 5-methylcytosine modification-dependent manner. Additionally, ribosomal S6 kinase 2 (RSK2) mediated YB-1 phosphorylation at Ser102 promotes YB-1/KLF5 transcriptional complex formation, which co-regulates the expression of BLBC specific genes, Keratin 16 (KRT16) and lymphocyte antigen 6 family member D (Ly6D), to promote cancer cell proliferation. The RSK inhibitor, LJH685, suppressed BLBC cell tumourigenesis in vivo by disturbing YB-1-KLF5 axis. Our data suggest that YB-1 positively regulates KLF5 at multiple levels to promote BLBC progression. The novel RSK2-YB-1-KLF5-KRT16/Ly6D axis provides candidate diagnostic markers and therapeutic targets for BLBC.

YB-1 as an Oncoprotein: Functions, Regulation, Post-Translational Modifications, and Targeted Therapy

Y box binding protein 1 (YB-1) is a protein with a highly conserved cold shock domain (CSD) that also belongs to the family of DNA- and RNA-binding proteins. YB-1 is present in both the nucleus and cytoplasm and plays versatile roles in gene transcription, RNA splicing, DNA damage repair, cell cycle progression, and immunity. Cumulative evidence suggests that YB-1 promotes the progression of multiple tumor types and serves as a potential tumor biomarker and therapeutic target. This review comprehensively summarizes the emerging functions, mechanisms, and regulation of YB-1 in cancers, and further discusses targeted strategies.

LncRNA HOXC-AS3 promotes non-small-cell lung cancer growth and metastasis through upregulation of YBX1

NSCLC is common and is the primary cause of cancer-related deaths due to a lack of early diagnosis and its propensity for metastasis. The pathogenesis of NSCLC is still unclear. Here, we explored the molecular mechanisms underlying NSCLC development, focusing on the HOXC-AS3/YBX1/HOXC8 axis. Human NSCLC specimens and cell lines were used. qRT-PCR and western blotting were utilised to examine the levels of HOXC-AS3/YBX1/HOXC8. CCK-8, colony formation, scratch wound healing and Transwell assays were performed to evaluate cancer cell proliferation, migration and invasion. A nude mouse xenograft model was used to examine tumour growth and metastasis in vivo. RNA pull-down, chromatin immunoprecipitation, coimmunoprecipitation and dual-luciferase assays were applied to validate the interactions of HOXC-AS3/YBX1, MDM2/YBX1 and the YBX1/HOXC8 promoter. The levels of HOXC-AS3 and HOXC8 were increased in human NSCLC specimens and cells. Knockdown of HOXC-AS3 suppressed NSCLC cell proliferation, migration and invasion, as well as tumour growth and metastasis in vivo. HOXC-AS3 directly bound to YBX1 to suppress its ubiquitination mediated by MDM2. YBX1 bound to the HOXC8 promoter and enhanced its transcription. Knockdown of HOXC8 inhibited the effects of HOXC-AS3 overexpression on NSCLC. HOXC-AS3 promotes NSCLC growth and metastasis by stabilising YBX1 and thus increasing HOXC8 transcription. Our study indicates that the HOXC-AS3/YBX1/HOXC8 axis could serve as a biomarker for NSCLC diagnosis or as a target for therapy development.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND

Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma (HCC). Y-box binding protein 1 (YB-1) is closely correlated with tumors and drug resistance. However, the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.

AIM

To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.

METHODS

The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues. Next, we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib. Then, we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry and Western blotting assays. We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo. Moreover, we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing (DGE-seq).

RESULTS

YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues. YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis. Consistently, the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down. Furthermore, KEGG pathway enrichment analysis of DGE-seq demonstrated that the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was essential for the sorafenib resistance induced by YB-1. Subsequently, YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway (Akt1 and PIK3R1) as shown by searching the BioGRID and HitPredict websites. Finally, YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib, and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.

CONCLUSION

Overall, we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene, which is of great significance for the application of sorafenib in advanced-stage HCC.

The dual distinct role of telomerase in repression of senescence and myofibroblast differentiation

Many aging related diseases such as cancer implicate the myofibroblast in disease progression. Furthermore genesis of the myofibroblast is associated with manifestation of cellular senescence of unclear significance. In this study we investigated the role of a common regulator, namely telomerase reverse transcriptase (TERT), in order to evaluate the potential significance of this association between both processes. We analyzed the effects of TERT overexpression or deficiency on expression of CDKN2A and ACTA2 as indicators of senescence and differentiation, respectively. We assess binding of TERT or YB-1, a repressor of both genes, to their promoters. TERT repressed both CDKN2A and ACTA2 expression, and abolished stress-induced expression of both genes. Conversely, TERT deficiency enhanced their expression. Altering CDKN2A expression had no effect on ACTA2 expression. Both TERT and YB-1 were shown to bind the CDKN2A promoter but only YB-1 was shown to bind the ACTA2 promoter. TERT overexpression inhibited CDKN2A promoter activity while stimulating YB-1 expression and activation to repress ACTA2 gene. TERT repressed myofibroblast differentiation and senescence via distinct mechanisms. The latter was associated with TERT binding to the CDKN2A promoter, but not to the ACTA2 promoter, which may require interaction with co-factors such as YB-1.

A comprehensive review of the functions of YB-1 in cancer stemness, metastasis and drug resistance

The Y Box binding protein 1 (YB-1) is a member of the highly conserved Cold Shock Domain protein family with multifunctional properties both in the cytoplasm and inside the nucleus. YB-1 is also involved in various cellular functions, including regulation of transcription, mRNA stability, and splicing. Recent studies have associated YB-1 with the regulation of the malignant phenotypes in several tumor types. In this review article, we provide an in-depth and expansive review of the literature pertaining to the multiple physiological functions of YB-1. We will also review the role of YB-1 in cancer development, progression, metastasis, and drug resistance in various malignancies, with more weight on literature published in the last decade. The methodology included querying databases PubMed, Embase, and Google Scholar for Y box binding protein 1, YB-1, YBX1, and Y-box-1.

YBX1 regulated by Runx3-miR-148a-3p axis facilitates non-small-cell lung cancer progression

BACKGROUND

Y-box binding protein 1 (YBX1) is a common oncogene in non-small-cell lung cancer (NSCLC), which is regulated by microRNAs (miRNAs) and transcription factors. This research aims to explore the function of YBX1, miR-148a-3p and Runt-related transcription factor 3 (Runx3) in NSCLC development, and analyze their interactions.

METHODS

YBX1, miR-148a-3p and Runx3 levels were detected using quantitative reverse transcription polymerase chain reaction(RT-PCR), Western blotting or immunohistochemical staining. The functions of YBX1, miR-148a-3p and Runx3 were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, wound healing, transwell, flow cytometry, xenograft model and Western blotting analyses. The binding correlation was validated through dual-luciferase reporter analysis and chromatin immunoprecipitation (ChIP).

RESULTS

YBX1 expression was upregulated, and miR-148a-3p and Runx3 levels were reduced in NSCLC samples and cell lines. YBX1 silence restrained NSCLC cell proliferation, migration, invasion and tumor growth, and enhanced apoptosis. YBX1 was targeted via miR-148a-3p. MiR-148a-3p knockdown promoted cell proliferation, migration, invasion and tumor growth, and repressed apoptosis, and these effects were abolished by YBX1 silence. Runx3 upregulation restrained cell proliferation, migration, invasion and tumor growth, and facilitated apoptosis. Runx3 bound with miR-148a-3p promotor to regulate miR-148a-3p expression. Runx3 silence modulated YBX1 expression though miR-148a-3p to promote NSCLC progression by increasing Cyclin D1, Cyclin B1, Slug-1, MMP-2 and MMP-9 levels.

CONCLUSION

Runx3-miR-148a-3p axis targeted YBX1 to modulate NSCLC progression.

Y box binding protein 1 inhibition as a targeted therapy for ovarian cancer

Y box binding protein 1 (YB-1) is a multifunctional protein associated with tumor progression and the emergence of treatment resistance (TR). Here, we report an azopodophyllotoxin small molecule, SU056, that potently inhibits tumor growth and progression via YB-1 inhibition. This YB-1 inhibitor inhibits cell proliferation, resistance to apoptosis in ovarian cancer (OC) cells, and arrests in the G1 phase. Inhibitor treatment leads to enrichment of proteins associated with apoptosis and RNA degradation pathways while downregulating spliceosome pathway. In vivo, SU056 independently restrains OC progression and exerts a synergistic effect with paclitaxel to further reduce disease progression with no observable liver toxicity. Moreover, in vitro mechanistic studies showed delayed disease progression via inhibition of drug efflux and multidrug resistance 1, and significantly lower neurotoxicity as compared with etoposide. These data suggest that YB-1 inhibition may be an effective strategy to reduce OC progression, antagonize TR, and decrease patient mortality.

FOLFOX Therapy Induces Feedback Upregulation of CD44v6 through YB-1 to Maintain Stemness in Colon Initiating Cells

Cancer initiating cells (CICs) drive tumor formation and drug-resistance, but how they develop drug-resistance characteristics is not well understood. In this study, we demonstrate that chemotherapeutic agent FOLFOX, commonly used for drug-resistant/metastatic colorectal cancer (CRC) treatment, induces overexpression of CD44v6, MDR1, and oncogenic transcription/translation factor Y-box-binding protein-1 (YB-1). Our study revealed that CD44v6, a receptor for hyaluronan, increased the YB-1 expression through PGE2/EP1-mTOR pathway. Deleting CD44v6, and YB-1 by the CRISPR/Cas9 system attenuates the in vitro and in vivo tumor growth of CICs from FOLFOX resistant cells. The results of DNA:CD44v6 immunoprecipitated complexes by ChIP (chromatin-immunoprecipitation) assay showed that CD44v6 maintained the stemness traits by promoting several antiapoptotic and stemness genes, including cyclin-D1,BCL2,FZD1,GINS-1, and MMP9. Further, computer-based analysis of the clones obtained from the DNA:CD44v6 complex revealed the presence of various consensus binding sites for core stemness-associated transcription factors “CTOS” (c-Myc, TWIST1, OCT4, and SOX2). Simultaneous expressions of CD44v6 and CTOS in CD44v6 knockout CICs reverted differentiated CD44v6-knockout CICs into CICs. Finally, this study for the first time describes a positive feedback loop that couples YB-1 induction and CD44 alternative splicing to sustain the MDR1 and CD44v6 expressions, and CD44v6 is required for the reversion of differentiated tumor cells into CICs.

Potential Links between YB-1 and Fatty Acid Synthesis in Clear Cell Renal Carcinoma

According to the National Institutes of Health, clear cell renal cell carcinoma (ccRCC) is the most common type of Renal Cell Carcinoma (RCC), making up approximately 75% of total renal carcinoma cases. Clear cell Renal Cell Carcinoma is characterized by a significant accumulation of lipids in the cytoplasm, which allows light from microscopes to pass through giving them a "clear" phenotype. Many of these lipids are in the form of fatty acids, both free and incorporated into lipid droplets. RCC is typically associated with a poor prognosis due to the lack of specific symptoms. Some symptoms include blood in urine, fever, lump on the side, weight loss, fatigue, to name a few; all of which can be associated with non-specific, non-cancerous, health conditions that contribute to difficult diagnosis. Treatment of RCC has typically been centered around radical nephrectomy as the standard of care, but due to the potentially small size of lesions and the possibility of causing surgically induced chronic kidney disease, treatments have shifted to more cautious, less invasive approaches. These approaches include active surveillance, nephron-sparing surgery, and other minimally invasive techniques like cryotherapy and renal ablation. Although these techniques have had the desired effect of reducing the number of surgeries, there is still considerable potential for renal impairment and the chance that tumors can grow out of control without surgery. With the difficulty that surrounds the treatment of ccRCC and its considerably high mortality rate amongst urological cancers, it is important to look for novel approaches to improve patient outcomes. This review looks at available literature and our data that suggests the lipogenic enzyme stearoyl-CoA desaturase may be more beneficial to patient survival than once thought. As our understanding of the importance of lipids in cell metabolism and longevity matures, it is important to present new perspectives that present a new understanding of ccRCC and the role of lipids in survival mechanisms engaged by transformed cells during cancer progression. In this review, we provide evidence that pharmacological inhibition of lipid desaturation in renal cancer patients is not without risk, and that the presence of unsaturated fatty acids may be a beneficial factor in patient outcomes. Although more direct experimental evidence is needed to make definitive conclusions, it is clear that the work reviewed herein should challenge our current understanding of cancer biology and may inform novel approaches to the diagnosis and treatment of ccRCC.

YB-1 Knockdown Inhibits the Proliferation of Mesothelioma Cells through Multiple Mechanisms

Y-box binding protein-1 (YB-1) is a multifunctional oncoprotein that has been shown to regulate proliferation, invasion and metastasis in a variety of cancer types. We previously demonstrated that YB-1 is overexpressed in mesothelioma cells and its knockdown significantly reduces tumour cell proliferation, migration, and invasion. However, the mechanisms driving these effects are unclear. Here, we utilised an unbiased RNA-seq approach to characterise the changes to gene expression caused by loss of YB-1 knockdown in three mesothelioma cell lines (MSTO-211H, VMC23 and REN cells). Bioinformatic analysis showed that YB-1 knockdown regulated 150 common genes that were enriched for regulators of mitosis, integrins and extracellular matrix organisation. However, each cell line also displayed unique gene expression signatures, that were differentially enriched for cell death or cell cycle control. Interestingly, deregulation of STAT3 and p53-pathways were a key differential between each cell line. Using flow cytometry, apoptosis assays and single-cell time-lapse imaging, we confirmed that MSTO-211H, VMC23 and REN cells underwent either increased cell death, G1 arrest or aberrant mitotic division, respectively. In conclusion, this data indicates that YB-1 knockdown affects a core set of genes in mesothelioma cells. Loss of YB-1 causes a cascade of events that leads to reduced mesothelioma proliferation, dependent on the underlying functionality of the STAT3/p53-pathways and the genetic landscape of the cell.

Why Be One Protein When You Can Affect Many? The Multiple Roles of YB-1 in Lung Cancer and Mesothelioma

Lung cancers and malignant pleural mesothelioma (MPM) have some of the worst 5-year survival rates of all cancer types, primarily due to a lack of effective treatment options for most patients. Targeted therapies have shown some promise in thoracic cancers, although efficacy is limited only to patients harboring specific mutations or target expression. Although a number of actionable mutations have now been identified, a large population of thoracic cancer patients have no therapeutic options outside of first-line chemotherapy. It is therefore crucial to identify alternative targets that might lead to the development of new ways of treating patients diagnosed with these diseases. The multifunctional oncoprotein Y-box binding protein-1 (YB-1) could serve as one such target. Recent studies also link this protein to many inherent behaviors of thoracic cancer cells such as proliferation, invasion, metastasis and involvement in cancer stem-like cells. Here, we review the regulation of YB-1 at the transcriptional, translational, post-translational and sub-cellular levels in thoracic cancer and discuss its potential use as a biomarker and therapeutic target.

HMGA1 Modulates Gene Transcription Sustaining a Tumor Signalling Pathway Acting on the Epigenetic Status of Triple-Negative Breast Cancer Cells

Chromatin accessibility plays a critical factor in regulating gene expression in cancer cells. Several factors, including the High Mobility Group A (HMGA) family members, are known to participate directly in chromatin relaxation and transcriptional activation. The HMGA1 oncogene encodes an architectural chromatin transcription factor that alters DNA structure and interacts with transcription factors favouring their landing onto transcription regulatory sequences. Here, we provide evidence of an additional mechanism exploited by HMGA1 to modulate transcription. We demonstrate that, in a triple-negative breast cancer cellular model, HMGA1 sustains the action of epigenetic modifiers and in particular it positively influences both histone H3S10 phosphorylation by ribosomal protein S6 kinase alpha-3 (RSK2) and histone H2BK5 acetylation by CREB-binding protein (CBP). HMGA1, RSK2, and CBP control the expression of a set of genes involved in tumor progression and epithelial to mesenchymal transition. These results suggest that HMGA1 has an effect on the epigenetic status of cancer cells and that it could be exploited as a responsiveness predictor for epigenetic therapies in triple-negative breast cancers.

The Promoter-Associated Noncoding RNA pncCCND1_B Assembles a Protein-RNA Complex to Regulate Cyclin D1 Transcription in Ewing Sarcoma

Most Ewing sarcomas are characterized by the in-frame chromosomal translocation t(11;22) generating the EWS-FLI1 oncogene. EWS-FLI1 protein interacts with the RNA helicase DHX9 and affects transcription and processing of genes involved in neoplastic transformation, including CCND1 (the cyclin D1 gene), which contributes to cell-cycle dysregulation in cancer. In this study, we found that CCND1 expression is significantly higher in patients with Ewing sarcoma compared with other sarcomas and that the pncCCND1_B RNA, a previously uncharacterized CCND1 promoter-associated noncoding (pnc) transcript, is expressed in Ewing sarcoma cells. PncCCND1_B interacted with the RNA-binding protein Sam68 and repressed CCND1 expression. Notably, knockdown of Sam68 affected pncCCND1_B subcellular localization and cyclin D1 expression. Pharmacologic impairment of DHX9/EWS-FLI1 interaction promoted RNA-dependent association of Sam68 with DHX9 and recruitment of Sam68 to the CCND1 promoter, thus repressing it. Conversely, mitogenic stimulation of Ewing sarcoma cells with IGF1 impaired Sam68/DHX9 interaction and positively regulated CCND1 expression. These studies uncover a fine-tuned modulation of the proto-oncogene CCND1 in Ewing sarcoma cells via alternative complexes formed by DHX9 with either EWS-FLI1 or pncCCND1_B-Sam68. SIGNIFICANCE: A pncRNA-based mechanism represses expression of CCND1 through the formation of a protein-RNA complex and provides new therapeutic opportunities for patients with Ewing sarcoma.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/14/3570/F1.large.jpg.

Thymoquinone-induced antitumor and apoptosis in human lung adenocarcinoma cells

BACKGROUND

Lung cancer has been associated with the highest cancer-associated mortality rate in the world. Chemotherapeutic management of cancer necessitates introducing new promising agents. Plants represent a rich source of new antineoplastic and chemotherapeutic agents. Thymoquinone (TQ), the main constituent of Nigella sativa (black seed or black cumin), has shown potent antioxidant and anti-inflammatory activities so far. The purpose of the current study was to evaluate the antineoplastic potential of TQ and their underlying mechanisms in A549 cells (human lung cancer cell line).

METHOD

The A549 cells were treated with the different concentrations of TQ for three following days. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Necrosis and apoptosis were assessed by fluorescence-activated cell sorter analysis through propidium iodide and annexin V staining and also by assessing caspase-3 and -9 activation. DNA fragmentation was monitored by gel electrophoresis.

RESULTS

TQ decreased the viability and increased apoptotic cell death in A549 human lung tumor cells. TQ treatment significantly elevated the Bax/ Bcl-2 ratio in the lung cancer cells. TQ also upregulated p53 expression, another apoptotic modulator in A549 cancer cells. TQ also activated caspase-dependent apoptosis by the activation of caspases-3 and -9.

CONCLUSION

Our results proposed that TQ may be a potential new therapeutic agent for the management of lung cancer. TQ promoted apoptosis in A546 lung cancer cells by the activation of p53 and caspase cascade dependent pathways.

YBX1 regulates tumor growth via CDC25a pathway in human lung adenocarcinoma

Y-box binding protein 1 (YBX1) is involved in the multi-tumor occurrence and development. However, the regulation of YBX1 in lung tumorigenesis and the underlying mechanisms, especially its relationship with CDC25a, was remains unclear. In this study, we analyzed the expression and clinical significance of YBX1 and CDC25a in lung adenocarcinoma and identified their roles in the regulation of lung cancer growth. The retrospective analysis of 116 patients with lung adenocarcinoma indicated that YBX1 was positively correlated with CDC25a expression. The Cox-regression analysis showed only high-ranking TNM stage and low CDC25a expression were an independent risk factor of prognosis in enrolled patients. High expression of YBX1 or CDC25a protein was also observed in lung adenocarcinoma cells compared with HLF cells. ChIP assay demonstrated the binding of endogenous YBX1 to the CDC25a promoter region. Overexpression of exogenous YBX1 up-regulated the expression of the CDC25a promoter-driven luciferase. By contrast, inhibition of YBX1 by siRNA markedly decreased the capability of YBX1 binding to CDC25a promoter in A549 and H322 cells. Inhibition of YBX1 expression also blocked cell cycle progression, suppressed cell proliferation and induced apoptosis via the CDC25a pathway in vitro. Moreover, inhibition of YBX1 by siRNA suppressed tumorigenesis in a xenograft mouse model and down-regulated the expression of YBX1, CDC25a, Ki67 and cleaved caspase 3 in the tumor tissues of mice. Collectively, these results demonstrate inhibition of YBX1 suppressed lung cancer growth partly via the CDC25a pathway and high expression of YBX1/CDC25a predicts poor prognosis in human lung adenocarcinoma.

Plasma MiRNA alterations between NSCLC patients harboring Del19 and L858R EGFR mutations

Based on recognition of driver mutations, treatment paradigm for non-small-cell lung cancer (NSCLC) patients has been shifted. However, recently exon 19 deletion mutation (del19) of epidermal growth factor receptor (EGFR) clearly shows better clinical benefit over single-point substitution mutation L858R in exon 21 (L858R). The aim of this study was to investigate the difference by analyzing the expression of plasma microRNAs (miRNAs) of NSCLC patients with EGFR mutation del19 or L858R. MiRNA microarray of plasma from patients' blood identified 79 mapped, network-eligible miRNAs (fold > 5), of which 76 were up regulated and 3 were down regulated. Genetic network was performed with Ingenuity Pathway Analysis (IPA). Among analysis, MYC, Argonaute2 (AGO2), Y-box binding protein 1 (YBX1), cyclin E1 (CCNE1) were involved in organismal abnormalities and cancer. Our findings provide information on the epigenetic signature of the two major sensitive mutations among NSCLC and add to the understanding of mechanisms underlying the different outcomes.

The association between CCND1 G870A polymorphism and colorectal cancer risk: A meta-analysis

BACKGROUND

CyclinD1 (CCND1) is a key cell cycle regulatory protein. A large number of epidemiological studies have assessed the potential correlation between the CCND1 G870A polymorphism and the risk of colorectal cancer (CRC), but their findings have been inconsistent. To obtain a more precise understanding of the association between the G870A polymorphism in the CCND1 gene and the CRC risk, we conducted a more comprehensive meta-analysis.

METHODOLOGY

We searched PubMed, Ovid, Springer, Weipu, China National Knowledge Infrastructure (CNKI), and Wanfang databases, covering all publications (the last search was updated on January 10, 2017). The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. Statistical analyses were performed using Review Manager 5.3 and STATA 10.0 software.

RESULTS

A total of 7276 CRC patients and 9667 controls from 27 publications were included in this meta-analysis. We found that compared with GG homozygote genetic model, AA, AG, AA + AG genetic models of the CCND1 G870A polymorphism were significantly associated with overall CRC risk (AA homozygote genetic model: OR = 1.28, 95% CI = 1.10-1.49; AG heterozygote genetic model: OR = 1.15, 95% CI = 1.06-1.25; AA homozygote + AG heterozygote genetic model: OR = 1.19, 95% CI = 1.07-1.33). Subgroup analyses by ethnicity and cancer location showed that A carriers were consistently associated with a significantly increased risk of CRC in all subsets of participants (Asian and Caucasian; colon cancer and rectal cancer). When stratified by study design, we found a significant association in hospital-based studies (HB), but no significant associations were found in either population-based studies (PB) or family-based studies (FB). According to subgroup analysis by cancer type, the risk of sporadic colorectal cancer (sCRC) and hereditary nonpolyposis colorectal cancer (HNPCC) were not correlated with the CCND1 G870A polymorphism, except AG (AG vs GG: OR = 1.30, 95% CI = 1.11-1.53).

CONCLUSIONS

This meta-analysis suggests that the CCND1 G870A polymorphism is associated with an increased risk of CRC, especially that A carriers may be a major risk factor for CRC.

Shrimp miR-S8 Suppresses the Stemness of Human Melanoma Stem-like Cells by Targeting the Transcription Factor YB-1

Cross-species regulation of gene expression by microRNA is a possible untapped opportunity for miRNA-based therapy. In this study, we report a novel approach to ablate melanoma stem-like cells by targeting the transcription factor YB-1, which is significantly and selectively upregulated in these cells in melanoma. Silencing YB-1 expression was sufficient to significantly inhibit the stemness of melanoma stem-like cells. In exploring YB-1 targeting, we discovered that the shrimp microRNA miR-S8 could suppress human YB-1 expression in melanoma stem-like cells. Mechanistic investigations revealed that miR-S8 recognized the 3'UTR of YB-1 mRNA and mediated its degradation. In tumor cell and xenograft experiments, miR-S8 suppressed the tumorigenic capacity of melanoma stem-like cells by targeting human YB-1. Overall, our results illuminated a novel aspect of miRNA-mediated cross-species gene expression and its use in regulating cancer stem-like cells. Cancer Res; 77(20); 5543-53. ©2017 AACR.

Y-box Protein-1 Regulates the Expression of Collagen I in Hepatic Progenitor Cells via PDGFR-β/ERK/p90RSK Signalling

Y-box protein-1 (YB-1) is a highly conserved transcription factor that is involved in multiple biological processes via transcriptional regulation of several genes, including p53, cyclin D1, and EGFR. YB-1 has been reported to be overexpressed in injured livers. This study aims to explore the functions of YB-1 in hepatic progenitor cells (HPCs). Herein, chromatin immunoprecipitation sequencing (ChIP-sequencing) and RNA-sequencing assays identified that YB-1 participated in the biological adhesion process and ECM-receptor interactions in HPCs. Further study demonstrated that YB-1 modulated the expression of extracellular matrix components in HPCs. ChIP-sequencing assays established that PDGFR-β was a target gene of YB-1, and luciferase reporter assays confirmed that YB-1 negatively regulated PDGFR-β promoter activity in HPCs. In addition, PDGFR-β can regulate the expression of collagen I through ERK/p90RSK signalling, and disruption of the signalling pathway with a PDGFR-β inhibitor or ERK1/2 inhibitor abolished the regulatory effect of PDGFR-β on collagen I expression in HPCs. Conclusively, YB-1 can modulate the expression of collagen I in HPCs via direct binding to the PDGFR-β promoter, negatively regulating its expression. In addition, the ERK/p90RSK axis serves as the downstream signalling pathway of PDGFR-β.

Homeobox Transcription Factor NKX2-1 Promotes Cyclin D1 Transcription in Lung Adenocarcinomas

The known oncogene cyclin D1 (CCND1) participates in progression of the cell cycle from G₁ to S-phase. Expression of cyclin D1 is frequently promoted in multiple human cancers including non-small cell lung cancer (NSCLC). However, a relationship between cyclin D1 expression and the prognosis of NSCLC has not been confirmed. NKX2-1 is a homeobox transcription factor involved in pulmonary development as a differentiation-promoting factor. In NSCLC, it acts as a metastasis suppressor and correlates with a good prognosis. Here, NKX2-1-binding motifs were identified in the cyclin D1 promoter, but it has not been clarified whether NKX2-1 is involved in cyclin D1 expression in NSCLC. To shed light on this issue, endogenous NKX2-1 was depleted in NSCLC cell lines, which resulted in decreased cyclin D1 mRNA and protein. In contrast, forced overexpression of NKX2-1 increased cyclin D1 levels. Moreover, NKX2-1 directly bound to the cyclin D1 promoter and enhanced its activity. Finally, using human NSCLC clinical specimens, it was determined that both NKX2-1 protein and mRNA were significantly correlated with cyclin D1 expression status in adenocarcinomas. These results indicate that NKX2-1 directly and positively regulates transcription of cyclin D1 Finally, expression of NKX2-1, but not cyclin D1, was significantly associated with metastatic incidence as an independent good prognostic factor of adenocarcinoma.Implications: NKX2-1-expressing adenocarcinomas, whereas NKX2-1 promoted cyclin D1 expression, may show good prognosis features by the metastasis inhibition potency of NKX2-1 regardless cyclin D1 expression. Mol Cancer Res; 15(10); 1388-97. ©2017 AACR.

The Atypical Dual Specificity Phosphatase hYVH1 Associates with Multiple Ribonucleoprotein Particles

Human YVH1 (hYVH1), also known as dual specificity phosphatase 12 (DUSP12), is a poorly characterized atypical dual specificity phosphatase widely conserved throughout evolution. Recent findings have demonstrated that hYVH1 expression affects cellular DNA content and is a novel cell survival phosphatase preventing both thermal and oxidative stress-induced cell death, whereas studies in yeast have established YVH1 as a novel 60S ribosome biogenesis factor. In this study, we have isolated novel hYVH1-associating proteins from human U2OS osteosarcoma cells using affinity chromatography coupled to mass spectrometry employing ion mobility separation. Numerous ribosomal proteins were identified, confirming the work done in yeast. Furthermore, proteins known to be present on additional RNP particles were identified, including Y box-binding protein 1 (YB-1) and fragile X mental retardation protein, proteins that function in translational repression and stress granule regulation. Follow-up studies demonstrated that hYVH1 co-localizes with YB-1 and fragile X mental retardation protein on stress granules in response to arsenic treatment. Interestingly, hYVH1-positive stress granules were significantly smaller, whereas knocking down hYVH1 expression attenuated stress granule breakdown during recovery from arsenite stress, indicating a possible role for hYVH1 in stress granule disassembly. These results propagate a role for dual specificity phosphatases at RNP particles and suggest that hYVH1 may affect a variety of fundamental cellular processes by regulating messenger ribonucleoprotein (mRNP) dynamics.

Hyper-O-GlcNAcylation of YB-1 affects Ser102 phosphorylation and promotes cell proliferation in hepatocellular carcinoma

As an essential post-translational modification, O-GlcNAcylation has been thought to be able to modulate various nuclear and cytoplasmic proteins and is emerging as a key regulator of multiple biological processes, such as transcription, cell growth, signal transduction, and cell motility. Recently, authoritative glycomics analyses have reported extensive crosstalk between O-GlcNAcylation and phosphorylation, which always dynamically interplay with each other and regulate signaling, transcription, and other cellular processes. Also, plentiful studies have shown close correlation between YB-1 phosphorylation and tumorigenesis. Therefore, our study aimed to determine whether YB-1 was O-GlcNAc modified and whether such modification could interact with its phosphorylation during the process of HCC development. Western blot and immunohistochemistry were firstly conducted to reveal obvious up-regulation of YB-1, OGT and O-GlcNAc modification in HCC tissues. What is more, not only YB-1 was identified to be O-GlcNAcylated but hyper-O-GlcNAcylation was demonstrated to facilitate HCC cell proliferation in a YB-1 dependent manner. Moreover, we detected four specific O-GlcNAc sites and confirmed T126A to be the most effective mutant in HCC cell proliferation via close O-GlcNAcylation-phosphorylation interaction. Even more interestingly, we discovered that T126A-induced HCC cell retardation and subdued transcriptional activity of YB-1 could be partially reversed by T126A/S102E mutant. From all above, it is not difficult to find that glycosylated-YB-1 mainly enhanced cell proliferation through congenerous actions with YB-1 phosphorylation and thus played indispensable roles in fine-tuning cell proliferation and procession of HCC.

Y-box-binding protein-1 (YB-1) promotes cell proliferation, adhesion and drug resistance in diffuse large B-cell lymphoma

YB-1 is a multifunctional protein, which has been shown to correlate with resistance to treatment of various tumor types. This study investigated the expression and biologic function of YB-1 in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical analysis showed that the expression statuses of YB-1 and pYB-1(S102) were reversely correlated with the clinical outcomes of DLBCL patients. In addition, we found that YB-1 could promote the proliferation of DLBCL cells by accelerating the G1/S transition. Ectopic expression of YB-1 could markedly increase the expression of cell cycle regulators cyclin D1 and cyclin E. Furthermore, we found that adhesion of DLBCL cells to fibronectin (FN) could increase YB-1 phosphorylation at Ser102 and pYB-1(S102) nuclear translocation. In addition, overexpression of YB-1 could increase the adhesion of DLBCL cells to FN. Intriguingly, we found that YB-1 overexpression could confer drug resistance through cell-adhesion dependent and independent mechanisms in DLBCL. Silencing of YB-1 could sensitize DLBCL cells to mitoxantrone and overcome cell adhesion-mediated drug resistance (CAM-DR) phenotype in an AKT-dependent manner.

High expression of Y-box-binding protein 1 correlates with poor prognosis and early recurrence in patients with small invasive lung adenocarcinoma

Background

Prognosis of small (≤2 cm) invasive lung adenocarcinoma remains poor, and identification of high-risk individuals from the patients after complete surgical resection of lung adenocarcinoma has become an urgent problem. YBX1 has been reported to be able to predict prognosis in many cancers (except lung adenocarcinoma) that are independent of TNM (tumor, nodes, metastases) staging, especially small invasive lung adenocarcinoma. Therefore, we examined the significance of YBX1 expression on prognosis and recurrence in patients with small invasive lung adenocarcinoma.

Material and methods

A total of 75 patients with small invasive lung adenocarcinoma after complete resection were enrolled from January 2008 to December 2010. Immunohistochemical staining was used to detect the expression of YBX1, and receiver operating characteristic curve analysis was performed to precisely assess the overall expression of YBX1. Meanwhile, primary lesions were identified based on the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society’s classification of lung adenocarcinoma. The effect of different clinicopathological factors on patients’ survival was examined. Furthermore, Western blot analysis was used to show the expression of YBX1 in vitro.

Results

Sensitivity and specificity of YBX1 for detecting small invasive lung adenocarcinoma from normal surrounding tissue were 66.7% and 74.7% (area under the receiver operating characteristic curve =0.731; P<0.001), respectively. High YBX1 expression was detected in 31 (41.3%) patients, and in A549, H322, Hcc827, and H1299 lung adenocarcinoma cells but not in HLF cells. In addition to sex, age, tumor size, TNM staging, pleural invasion, and lymph node metastasis, the expression of YBX1 was associated with the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society pathological grade risk (P=0.026) and differentiation (P=0.009). The patients with low YBX1 expression lived longer than those with high expression (5-year overall survival: 52.3% vs 79.0%; P=0.039) and showed fewer recurrences (P=0.024). In multivariate analyses, high YBX1 expression (odds ratio =2.737; 95% confidence interval: 1.058–7.082; P=0.038) was shown as an independent risk factor of overall survival but not of disease-free survival (odds ratio =1.696; 95% confidence interval: 0.616–4.673; P=0.307).

Conclusion

YBX1 is an important predictor for the prognosis in patients with small invasive lung adenocarcinoma after complete resection.

Nuclear expression of Y-box binding protein-1 is associated with poor prognosis in patients with pancreatic cancer and its knockdown inhibits tumor growth and metastasis in mice tumor models

The objective of this study was to examine the implication of Y-box-binding protein-1 (YB-1) for the aggressive phenotypes, prognosis and therapeutic target in pancreatic ductal adenocarcinoma (PDAC). YB-1 expression in PDAC, pancreatic intraepithelial neoplasia (PanIN) and normal pancreas specimens was evaluated by immunohistochemistry, and its correlation with clinicopathological features was assessed in patients with PDAC. The effects of YB-1 on proliferation, invasion and expressions of cell cycle-related proteins and matrix metalloproteinases (MMPs) were analyzed by WST-8, cell cycle and Matrigel invasion assays, Western blotting and quantitative RT-PCR in PDAC cells transfected with YB-1-siRNAs. To verify the significance of YB-1 for tumor progression in vivo, the growth and metastasis were monitored after intrasplenic implantation of ex vivo YB-1 siRNA-transfected PDAC cells, and YB-1-targeting antisense oligonucleotides were intravenously administered in nude mice harboring subcutaneous tumor. The intensity of YB-1 expression and positivity of nuclear YB-1 expression were higher in PDAC than PanIN and normal pancreatic tissues. Nuclear YB-1 expression was significantly associated with dedifferentiation, lymphatic/venous invasion and unfavorable prognosis. YB-1 knockdown inhibited cell proliferation via cell cycle arrest by S-phase kinase-associated protein 2 downregulation and consequent p27 accumulation, and decreased the invasion due to downregulated membranous-type 2 MMP expression in PDAC cells. Tumor growth and liver metastasis formation were significantly suppressed in nude mice after implantation of YB-1-silenced PDAC cells, and the YB-1 targeting antisense oligonucleotide significantly inhibited the growth of subcutaneous tumors. In conclusion, YB-1 may be involved in aggressive natures of PDAC and a promising therapeutic target.

Role of post-translational modification of the Y box binding protein 1 in human cancers

Y box binding protein-1 (YBX1) belongs to a DNA- and RNA-binding family of transcription factors, containing the highly conserved cold shock domain (CSD). YBX1 is involved in a number of cellular functions including transcription, translation, DNA damage repair etc., and it is upregulated during times of environmental stress. YBX1 is localized in both the cytoplasm and the nucleus. There, its nuclear translocation is observed in a number of cancers and is associated with poor prognosis and disease progression. Additionally, YBX1 expression is upregulated in a variety of cancers, pointing towards its role as a potential oncogene. Under certain circumstances, YBX1 also promotes the expression of multidrug resistance 1 (MDR1) gene, which is involved in the development of drug resistance. Thus, it is critical to understand the mechanism of YBX1 regulation and its downstream effects on promoting cancer development. A number of recent studies have highlighted the mechanisms of YBX1 regulation. Mass spectrometric analyses have reported several post-translational modifications that possibly play an important role in modulating YBX1 function. Phosphorylation is the most widely occurring post-translational modification in YBX1. In vivo analyses of sites like S102 and more recently, S165 illustrate the relationship of post-translational regulation of YBX1 in promoting cell proliferation and tumor growth. This review provides a comprehensive and up-to-date account of post-translational modifications identified in YBX1. This knowledge is a key in allowing us to better understand the mechanism of YBX1 regulation, which will aid in development of novel therapeutic strategies to target YBX1 in many types of cancer in the future.

shRNA-Mediated Silencing of Y-Box Binding Protein-1 (YB-1) Suppresses Growth of Neuroblastoma Cell SH-SY5Y In Vitro and In Vivo

Y-box binding protein-1 (YB-1), a member of cold-shock protein superfamily, has been demonstrated to be associated with tumor malignancy, and is proposed as a prognostic marker in multiple carcinomas. However, the role of YB-1 in neuroblastoma has not been well studied. To investigate the functional role of YB-1 in neuroblastoma, we established a YB-1-silenced neuroblastoma cell strain by inhibiting YB-1 expression using a shRNA knockdown approach. YB-1-silenced neuroblastoma SH-SY5Y cells exhibited a pronounced reduction in cell proliferation and an increased rate of apoptosis in vitro and in vivo xenograft tumor model. At molecular level, YB-1 silencing resulted in downregulation of Cyclin A, Cyclin D1 and Bcl-2, as well as upregulated levels of Bax, cleaved caspase-3 and cleaved PARP-1. We further demonstrated that YB-1 transcriptionally regulated Cyclin D1 expression by chromatin-immunoprecipitation and luciferase reporter assays. In addition, xenograft tumors derived from neuroblastoma SH-SY5Y cell line were treated with YB-1 shRNA plasmids by intra-tumor injection, and YB-1 targeting effectively inhibited tumor growth and induced cell death. In summary, our findings suggest that YB-1 plays a critical role in neuroblastoma development, and it may serve as a potential target for neuroblastoma therapy.