circNEIL3 inhibits tumor metastasis through recruiting the E3 ubiquitin ligase Nedd4L to degrade YBX1

Distant metastasis is a major contributor to cancer-related mortality. However, the role of circRNAs in this process remains unclear. Herein, we profiled the circRNA expression in a cohort of 68 colorectal carcinoma (CRC) primary tumors and their paired liver metastatic lesions. By overlapping with the TGFβ-responsive circRNAs, circNEIL3 (hsa_circ_0001460) was identified as a TGFβ-repressive and metastasis-related circRNA. Functionally, circNEIL3 effectively inhibited tumor metastasis in both and in vivo and in vivo models of various cancer types. Mechanistically, circNEIL3 exerts its metastasis-repressive function through its direct interaction with oncogenic protein, Y-box-binding protein 1 (YBX1), which consequently promotes the Nedd4L-mediated proteasomal degradation of YBX1. Importantly, circNEIL3 expression was negatively correlated to YBX1 protein level and metastatic tendency in CRC patient samples. Collectively, our findings indicate the YBX1-dependent antimetastatic function of circNEIL3 and highlight the potential of circNEIL3 as a biomarker and therapeutic option in cancer treatment.

Regulation of Metastasis in Ewing Sarcoma

Ewing sarcoma (EwS) is a type of bone and soft tissue tumor in children and adolescents. Over 85% of cases are caused by the expression of fusion protein EWSR1-FLI1 generated by chromosome translocation. Acting as a potent chimeric oncoprotein, EWSR1-FLI1 binds to chromatin, changes the epigenetic states, and thus alters the expression of a large set of genes. Several studies have revealed that the expression level of EWSR1-FLI1 is variable and dynamic within and across different EwS cell lines and primary tumors, leading to tumoral heterogeneity. Cells with high EWSR1-FLI1 expression (EWSR1-FLI1-high) proliferate in an exponential manner, whereas cells with low EWSR1-FLI1 expression (EWSR1-FLI1-low) tend to have a strong propensity to migrate, invade, and metastasize. Metastasis is the leading cause of cancer-related deaths. The continuous evolution of EwS research has revealed some of the molecular underpinnings of this dissemination process. In this review, we discuss the molecular signatures that contribute to metastasis.

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.

Targeting the Y-box Binding Protein-1 Axis to Overcome Radiochemotherapy Resistance in Solid Tumors

Multifunctional Y-box binding protein-1 (YB-1) is highly expressed in different human solid tumors and is involved in various cellular processes. DNA damage is the major mechanism by which radiochemotherapy (RCT) induces cell death. On induction of DNA damage, a multicomponent signal transduction network, known as the DNA damage response, is activated to induce cell cycle arrest and initiate DNA repair, which protects cells against damage. YB-1 regulates nearly all cancer hallmarks described to date by participating in DNA damage response, gene transcription, mRNA splicing, translation, and tumor stemness. YB-1 lacks kinase activity, and p90 ribosomal S6 kinase and AKT are the key kinases within the RAS/mitogen-activated protein kinase and phosphoinositide 3-kinase pathways that directly activate YB-1. Thus, the molecular targeting of ribosomal S6 kinase and AKT is thought to be the most effective strategy for blocking the cellular function of YB-1 in human solid tumors. In this review, after describing the prosurvival effect of YB-1 with a focus on DNA damage repair and cancer cell stemness, clinical evidence will be provided indicating an inverse correlation between YB-1 expression and the treatment outcome of solid tumors after RCT. In the interest of being concise, YB-1 signaling cascades will be briefly discussed and the current literature on YB-1 posttranslational modifications will be summarized. Finally, the current status of targeting the YB-1 axis, especially in combination with RCT, will be highlighted.

Long noncoding RNA SNHG6 promotes carcinogenesis by enhancing YBX1-mediated translation of HIF1α in clear cell renal cell carcinoma

Recent studies have showed that Small nucleolar RNA host genes (SNHGs) acted as a subset of long noncoding RNAs (lncRNAs) have critical roles in human cancer carcinogenesis. However, the biological functions of SNHGs in clear cell renal cell carcinoma (ccRCC) have not been fully investigated. In this study, we screened an oncogenic lncRNA termed SNHG6 using RNA-Seq data of ccRCC from The Cancer Genome Atlas (TCGA). Quantitative real-time PCR was then used to demonstrate the expression of SNHG6 in ccRCC tissues. SNHG6 overexpression is highly associated with malignant features in patients and is a prognostic indicator. SNHG6 significantly promotes ccRCC cell proliferation and metastasis in vitro and in vivo. Mechanistic investigations identified that SNHG6 exerts oncogenic effects by interacting with YBX1, and then, enhancing HIF1α translation. Taken together, SNHG6 promotes ccRCC progression by binding YBX1 and may serve as a novel molecular target for ccRCC therapy.

Y-box binding protein 1 (YB-1) promotes gefitinib resistance in lung adenocarcinoma cells by activating AKT signaling and epithelial-mesenchymal transition through targeting major vault protein (MVP)

PURPOSE

Gefitinib is a first-line treatment option for epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma. However, most patients inevitably develop gefitinib resistance. The mechanism underlying this resistance is not fully understood. Y-box binding protein 1 (YB-1) has been reported to play a role in modulating drug sensitivity, but its role in gefitinib resistance is currently unknown. Here, we investigated the role of YB-1 in gefitinib resistance of lung adenocarcinoma.

METHODS

We determined the expression of YB-1, epithelial-mesenchymal transition (EMT) and AKT signaling markers, as well as the viability of lung adenocarcinoma cell lines bearing mutant (HCC827, PC-9) or wild-type (H1299) EGFR. We also evaluated PC-9 cell migration and invasion using transwell assays. The clinical importance of YB-1 and major vault protein (MVP) was evaluated using primary lung adenocarcinoma patient samples.

RESULTS

We found that YB-1 was significantly upregulated in gefitinib-resistant lung adenocarcinoma cells compared to gefitinib-sensitive cells. YB-1 augmented gefitinib resistance by activating the AKT pathway and promoting EMT. Decreased migration and invasion was observed upon MVP silencing in YB-1-overexpressing PC-9 cells, as well as restored gefitinib sensitivity. A retrospective analysis of 85 patients with lung adenocarcinoma revealed that YB-1 levels were significantly increased in tyrosine kinase inhibitor (TKI)-resistant patients compared to those in TKI-sensitive patients, indicating that YB-1 may serve as a biomarker to clinically predict acquired gefitinib resistance.

CONCLUSION

YB-1 activates AKT signaling and promotes EMT at least in part by directly activating MVP. Hence, targeting the YB-1/MVP axis may help to overcome gefitinib resistance in lung adenocarcinoma patients.

Elevated nuclear YBX1 expression and the clinicopathological characteristics of patients with solid tumors: a meta-analysis

Purpose: Y-box binding protein 1 (YBX1) is a multifunctional protein linked to tumor progression and its elevated expression is an indicator of poor prognosis in various cancers. This meta-analysis aimed to investigate the prognostic value and clinical significance of YBX1 in malignant cancer.

Methods: Relevant articles published through September 12, 2018 were identified from a comprehensive electronic and manual search in PubMed, Web of Science and Embase databases. The combined odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to estimate the relationship among clinicopathological characteristics, overall survival and disease-free-survival of patients with solid tumor and YBX1 expression.

Results: The study included 27 studies and 5,996 patients. Our analysis revealed significant association between increased YBX1 expression and tumor differentiation status, tumor size and lymph node metastasis; moreover, the pooled HR values demonstrated that high nuclear YBX1 expression was significantly associated with worse overall survival (HR=2.14; 95% CI: 1.72–2.67, P<0.001).

Conclusion: The evidence supports YBX1 as a tumor biomarker to guide clinical management and indicate prognosis.

[Impact of Her2 and BRCA1/2 status in high-dose chemotherapy and autologous stem cells transplantation in the treatment of breast cancer: The Institut Paoli Calmettes' experience]

INTRODUCTION

Studies evaluating chemotherapy high dose chemotherapy with autologous haematopoietic stem cell transplantation (HDC-ACSH) in the treatment of metastatic (MBC), locally advanced (LABC) and inflammatory (IBC) breast cancer have in common lack of biomarker information, in particular the HER2 status.

PATIENTS AND METHODS

All consecutive female patients treated for breast cancer with HDC and AHSCT at Institut Paoli Calmettes between 2003 and 2012 were included. Patients were categorized in three subtypes based on hormonal receptor (HR) and HER2 status of the primary tumor: luminal, (HR+/HER2-), HER2 (HER2+, any HR) and triple negative (TN) (HER2- and HR-). The main objective was the analysis of overall survival (OS) according to the IHC subtypes.

RESULTS

Three hundred and seventy-seven patients were included. For MBC, the TN subtype appeared to have the worst prognosis with a median OS of 19.68 months (95 % CI 11.76-44.4) compared to 44.64 months (95 % CI 40.32-67.56) for the luminal subtype and a median OS not reached for the HER2 subtype (P<0.01). For IBC, HER2 subgroup appeared to have the best prognosis with a 5-year OS of 89 % (95 % CI 64-97) compared to 57 % (95 % CI 33-76) for the TN subgroup (HR 5.38, 95 % CI 1.14-25.44; P=0.034). For CSLA, luminal subgroup appeared to have the best prognosis with a 5-year OS of 92 % (95 % CI 71-98) against 75 % (95 % CI 46-90) for HER 2 subtype and 70 % (95 %CI 97-88) for TN subtype (P=0.301).

CONCLUSION

The HDC-ACSH does not change the prognosis value of IHC subtype in breast cancer patients.

Serum YB-1 (Y-box binding protein 1) as a biomarker of bone disease progression in patients with breast cancer and bone metastases

YB-1 (Y-box binding protein 1) is a multifunctional cold-shock protein that has been implicated in all hallmarks of cancer. Elevated YB-1 protein level was associated with poor prognosis in several types of cancers, including breast cancer (BC), where it is a marker of decreased overall survival (OS) and distant metastasis-free survival across all subtypes. YB-1 is also secreted by different cell types and may act as an extracellular mitogen; however the pathological implications of the secreted form of YB-1 (sYB-1) are unknown. Our purpose was to retrospectively evaluate the association between YB-1 measured by ELISA in serum and disease characteristics and outcomes in patients with BC and bone metastases (BM). In our cohort, sYB-1 was detected in the serum of 22 (50%) patients, and was associated with the presence of extra-bone metastases (p=0.044). Positive sYB-1 was also associated with faster bone disease progression (HR 3.1, 95% CI 1.09–8.95, P=0.033), but no significant differences were observed concerning OS, and time to development of skeletal-related events. Moreover, patients with positive sYB-1 also had higher levels of IL-6, a known osteoclastogenic inducer. Therefore, detection of sYB-1 in patients with BC and BM may indicate a higher tumor burden, in bone and extra-bone locations, and is a biomarker of faster bone disease progression.

Prognostic impact of hormone receptor- and HER2-defined subtypes in inflammatory breast cancer treated with high-dose chemotherapy: a retrospective study

Purpose: Studies examining high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HDC-AHSCT) strategies in inflammatory breast cancer (IBC), showed encouraging results in terms of disease-free survival (DFS), and overall survival (OS). The lack of data regarding HER2 status in all of these studies prevented any prognostic analysis involving breast cancer subtypes. Methods: All consecutive female patients treated for IBC with HDC and AHSCT at Institut Paoli-Calmettes between 2003 and 2012 were included. Since 2005, trastuzumab was included in initial treatment. Patient, tumor and treatment characteristics were collected. Patients were categorized in three subtypes based on hormonal receptor (HR) and HER2 status of the primary tumor: Luminal, (HR+/HER2-), HER2 (HER2+, any HR), and triple negative (TN) (HER2- and HR-). The main objective was the analysis of OS according to the IHC subtypes. Results: Sixty-seven patients were included. Eleven patients received trastuzumab. Median follow up was 80.04 months (95% CI 73.2-88.08). Five-year OS and DFS for the whole population patients were 74% (95% CI 61-83) and 65 % (95% CI 52-75), respectively. OS differed across subtypes (p=0.057) : HER2 subgroup appeared to have the best prognosis with a 5-year OS of 89% (95% CI 64-97) compared to 57% (95% CI 33-76) for the TN subgroup (HR 5.38, 95% CI 1.14-25.44; p=0.034). Conclusions: In IBC patients receiving HDC-AHSCT, OS favorably compares with data available in the literature on similar groups of patients. TN patients carried the least favourable OS and HER2 patients, half of them also receiving trastuzumab, had the best outcome. These findings provide additional information and options for patients with IBC and who could potentially benefit of HDC-AHSCT.

Breast Cancer Resistance to Antiestrogens Is Enhanced by Increased ER Degradation and ERBB2 Expression

Endocrine therapies effectively improve the outcomes of patients with estrogen receptor (ER)-positive breast cancer. However, the emergence of drug-resistant tumors creates a core clinical challenge. In breast cancer cells rendered resistant to the antiestrogen fulvestrant, we defined causative mechanistic roles for the transcription factor YBX1 and the levels of ER and the ERBB2 receptor. Enforced expression of YBX1 in parental cells conferred resistance against tamoxifen and fulvestrant in vitro and in vivo Furthermore, YBX1 overexpression was associated with decreased and increased levels of ER and ERBB2 expression, respectively. In antiestrogen-resistant cells, increased YBX1 phosphorylation was associated with a 4-fold higher degradation rate of ER. Notably, YBX1 bound the ER, leading to its accelerated proteasomal degradation, and induced the transcriptional activation of ERBB2. In parallel fashion, tamoxifen treatment also augmented YBX1 binding to the ERBB2 promoter to induce increased ERBB2 expression. Together, these findings define a mechanism of drug resistance through which YBX1 contributes to antiestrogen bypass in breast cancer cells. Cancer Res; 77(2); 545-56. ©2016 AACR.

High-dose chemotherapy and autologous bone marrow or stem cell transplantation versus conventional chemotherapy for women with early poor prognosis breast cancer

BACKGROUND

Overall survival rates are disappointing for women with early poor prognosis breast cancer. Autologous transplantation of bone marrow or peripheral stem cells (in which the woman is both donor and recipient) has been considered a promising technique because it permits use of much higher doses of chemotherapy.

OBJECTIVES

To compare the effectiveness and safety of high-dose chemotherapy and autograft (either autologous bone marrow or stem cell transplantation) with conventional chemotherapy for women with early poor prognosis breast cancer.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialised Register, MEDLINE (1966 to October 2015), EMBASE (1980 to October 2015), the World Health Organization's International Clinical Trials Registry Search Platform, and ClinicalTrials.gov on the 21 October 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing high-dose chemotherapy and autograft (bone marrow transplant or stem cell rescue) versus chemotherapy without autograft for women with early poor prognosis breast cancer.

DATA COLLECTION AND ANALYSIS

Two review authors selected RCTs, independently extracted data and assessed risks of bias. We combined data using a Mantel-Haenszel fixed-effect model to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs). We assessed the quality of the evidence using GRADE methods. Outcomes were survival rates, toxicity and quality of life.

MAIN RESULTS

We included 14 RCTs of 5600 women randomised to receive high-dose chemotherapy and autograft (bone marrow transplant or stem cell rescue) versus chemotherapy without autograft for women with early poor prognosis breast cancer. The studies were at low risk of bias in most areas.There is high-quality evidence that high-dose chemotherapy does not increase the likelihood of overall survival at any stage of follow-up (at three years: RR 1.02, 95% CI 0.95 to 1.10, 3 RCTs, 795 women, I² = 56%; at five years: RR 1.00, 95% CI 0.96 to 1.04, 9 RCTs, 3948 women, I² = 0%; at six years: RR 0.94, 95% CI 0.81 to 1.08, 1 RCT, 511 women; at eight years: RR1.17, 95% CI 0.95 to 1.43, 1 RCT, 344 women; at 12 years: RR 1.18, 95% CI 0.99 to 1.42, 1 RCT, 382 women).There is high-quality evidence that high-dose chemotherapy improves the likelihood of event-free survival at three years (RR 1.19, 95% CI 1.06 to 1.34, 3 RCTs, 795 women, I² = 56%) but this effect was no longer apparent at longer duration of follow-up (at five years: RR 1.04, 95% CI 0.99 to 1.09, 9 RCTs, 3948 women, I² = 14%; at six years RR 1.04, 95% CI 0.87 to 1.24, 1 RCT, 511 women; at eight years: RR 1.27, 95% CI 0.99 to 1.64, 1 RCT, 344 women; at 12 years: RR 1.18, 95% CI 0.95 to 1.45, 1 RCT, 382 women).Treatment-related deaths were much more frequent in the high-dose arm (RR 7.97, 95% CI 3.99 to 15.92, 14 RCTs, 5600 women, I² = 12%, high-quality evidence) and non-fatal morbidity was also more common and more severe in the high-dose group. There was little or no difference between the groups in the incidence of second cancers at four to nine years' median follow-up (RR 1.25, 95% CI 0.90 to 1.73, 7 RCTs, 3423 women, I² = 0%, high-quality evidence). Women in the high-dose group reported significantly worse quality-of-life scores immediately after treatment, but there were few statistically significant differences between the groups by one year.The primary studies were at low risk of bias in most areas, and the evidence was assessed using GRADE methods and rated as high quality for all comparisons.

AUTHORS' CONCLUSIONS

There is high-quality evidence of increased treatment-related mortality and little or no increase in survival by using high-dose chemotherapy with autograft for women with early poor prognosis breast cancer.

YB-1, a new biomarker of glioma progression, is associated with the prognosis of glioma patients

Y box protein 1 (YB-1) is a multifunctional cellular protein expressed in various cancers, and is a potential target in cancer therapy. Although there is evidence showing that YB-1 plays a role in human cancers, the clinical significance of YB-1 expression in glioma has not been established. In the present study, we investigated the YB-1 level in glioma tumors and analyzed the relationship between the YB-1 level and the grade of malignant glioma, with the aim of providing new ideas for the diagnosis and treatment of gliomas in clinical and basic research settings. A total of 108 patients, comprising 14, 31, 30, and 33 with gliomas of Grades I, II, III, and IV, respectively, were included in this study. The mRNA and protein levels of YB-1 were found to be significantly different between Grade IV and lower-grade tumors. The YB-1 levels in cerebrospinal fluid were significantly higher in Grades III and IV glioma patients than in Grades I and II patients. Immunofluorescence staining was used to detect the levels of YB-1 in the cytoplasm and the nucleus, and results indicated that the intracellular distribution was significantly associated with the pathological grade of glioma. A higher level of YB-1 was associated with shortened survival, suggesting that YB-1 plays a role in the progression of human glioma.

GOLPH3 and YB-1 Are Novel Markers Correlating With Poor Prognosis in Prostate Cancer

Background

Prostate cancer is a common and aggressive cancer among men. Despite advances in the treatment, the mechanisms involved in progression are still unclear. New prognostic markers should be explored for better design of patient-specific therapeutic regimens.

Methods

This study was performed on 120 patients stratified as 76 with prostatic carcinoma, 12 with low-grade prostate intraepithelial lesion, 12 with high-grade prostate intraepithelial lesion and 20 with benign prostate hyperplasia. Immunohistochemical study was done for Golgi phosphoprotein 3 (GOLPH3) and Y-box binding protein-1 (YB-1) analysis. Correlation with clinicopathological data and overall survival was analyzed.

Results

Both GOLPH3 and YB-1 showed increased expression from benign to malignant tumors. In prostatic carcinoma, cytoplasmic GOLPH3 was associated with Gleason score, stage and androgen receptor (P = 0.034, P < 0.001, and P = 0.008 respectively). Nuclear YB-1 expression was associated with Gleason score and androgen receptor (P = 0.018 and P = 0.024 respectively). Cytoplasmic YB-1 expression was associated with Gleason score, stage and androgen receptor (P = 0.008, P = 0.027, and P < 0.001 respectively). High Gleason score (P = 0.004), high stage (P < 0.001) and androgen receptor (P = 0.006) were the only detected adverse prognostic clinicopathological factors. Moderate/intense GOLPH3 and high nuclear and cytoplasmic YB-1 expression were correlated with shorter overall survival (P < 0.001, P = 0.020, and P < 0.001 respectively). In the multivariate analysis, moderate/intense GOLPH3 expression was the only predictor of overall survival (P = 0.025).

Conclusions

High GOLPH3 and nuclear/cytoplasmic YB-1 expression correlated with poor prognosis in prostate cancer. Both markers can be promising targets for new treatment strategies.

Golgi Phosphoprotein-3 and Y-Box-Binding Protein-1 Are Novel Markers Correlating With Poor Prognosis in Prostate Cancer

BACKGROUND

Prostate cancer is a common and aggressive cancer among men. Despite advances in treatment, the mechanisms involved in progression are still unclear. New prognostic markers are needed to better design patient-specific therapeutic regimens.

MATERIALS AND METHODS

The present study included 120 patients: 76 with prostate carcinoma, 12 with low-grade prostate intraepithelial lesions, 12 with high-grade prostate intraepithelial lesions, and 20 with benign prostatic hyperplasia. Immunohistochemical study was performed for Golgi phosphoprotein-3 (GOLPH3) and Y-box-binding protein-1 (YB-1) analysis. The correlation with clinicopathologic data and overall survival was analyzed.

RESULTS

Both GOLPH3 and YB-1 showed increased expression from benign to malignant tumors. In prostate carcinoma, cytoplasmic GOLPH3 was associated with Gleason score, tumor stage, and androgen receptor status (P = .034, P < .001, and P = .008, respectively). Nuclear YB-1 expression was associated with Gleason score and androgen receptor status (P = .018 and P = .024, respectively). Cytoplasmic YB-1 expression was associated with Gleason score, tumor stage, and androgen receptor status (P = .008, P = .027, and P < .001, respectively). A high Gleason score (P = .004), high tumor stage (P < .001), and androgen receptor-independent cancer (P = .006) were the only detected adverse prognostic clinicopathologic factors. Moderate to intense GOLPH3 and high nuclear and cytoplasmic YB-1 expression correlated with shorter overall survival (P < .001, P = .020, and P < .001, respectively). On multivariate analysis, moderate to intense GOLPH3 expression was the only predictor of overall survival (P = .025).

CONCLUSION

High GOLPH3 and nuclear/cytoplasmic YB-1 expression correlated with a poor prognosis in patients with prostate cancer. Both markers could be promising targets for new treatment strategies.

[YB-1-based virotherapy: A new therapeutic intervention for transitional cell carcinoma of the bladder?]

Therapeutic intervention using oncolytic viruses is called virotherapy. This type of virus is defined by the ability to replicate in tumor cells only and to destroy these cells upon replication. In addition, this virus type is able to induce a tumor-directed immune response. Early clinical trials have confirmed the safety profile of oncolytic viruses. Currently, different groups are working on the development of oncolytic viruses with a focus on treatment of nonmuscle invasive bladder cancer (NMIBC). A preliminary active recruiting clinical phase II/III trial ongoing in patients with a NMIBC was recently implemented in the United States. Our research group developed an oncolytic adenovirus that will soon enter a clinical phase I trial in patients diagnosed with glioma. This virus is being further modified for the treatment of NMIBC. In this review article, recent developments in the design and use of virotherapy in bladder cancer are summarized.

Translational Activation of HIF1α by YB-1 Promotes Sarcoma Metastasis

Metastatic dissemination is the leading cause of death in cancer patients, which is particularly evident for high-risk sarcomas such as Ewing sarcoma, osteosarcoma, and rhabdomyosarcoma. Previous research identified a crucial role for YB-1 in the epithelial-to-mesenchymal transition (EMT) and metastasis of epithelial malignancies. Based on clinical data and two distinct animal models, we now report that YB-1 is also a major metastatic driver in high-risk sarcomas. Our data establish YB-1 as a critical regulator of hypoxia-inducible factor 1α (HIF1α) expression in sarcoma cells. YB-1 enhances HIF1α protein expression by directly binding to and activating translation of HIF1A messages. This leads to HIF1α-mediated sarcoma cell invasion and enhanced metastatic capacity in vivo, highlighting a translationally regulated YB-1-HIF1α axis in sarcoma metastasis.

Strong YB-1 expression predicts liver recurrence following resection for colorectal metastases

INTRODUCTION

The Y-box binding protein-1 (YB-1) is a multifunctional oncoprotein involved in the proliferation and aggressiveness of cancer cells. The aim of this study was to determine whether strong YB-1 expression in neoplastic cells of colorectal liver metastases (CRLM) may have an impact on liver disease-free survival following liver resection.

MATERIALS AND METHODS

Immunohistochemistry was performed to evaluate YB-1 in 66 patients who underwent liver resection for CRLM. YB-1 expression was classified as weak (low-staining intensity) and strong (high-staining intensity).

RESULTS

YB-1 expression was observed in the cytoplasm of all CRLM. YB-1 expression was weak in 17 patients (25.8%) and strong in 49 patients (74.2%). Liver recurrence rate was significantly higher in the strong than in the weak expression group: 55.1 vs. 23.5% (p = 0.023). Multivariable logistic regression analysis showed that YB-1 strong expression was the only independent risk factor for liver recurrence. The 5-year specific liver disease-free survival rate was 76.0% in the weak expression group and 41.5% in the strong expression group (p = 0.034). These results were not influenced by clinical prognostic factors of tumor recurrence.

CONCLUSIONS

This is the first study showing that the degree of YB-1 expression in tissue specimens of CRLM predicts liver recurrence following liver resection.

Adjuvant high-dose chemotherapy with autologous hematopoietic stem cell support for high-risk primary breast cancer: results from the Italian national registry

The efficacy of high-dose chemotherapy (HDC) and autologous hemopoietic progenitor cell transplantation (AHPCT) for breast cancer (BC) patients has been an area of intense controversy among the medical oncology community. The aim of this study was to assess toxicity and efficacy of this procedure in a large cohort of high-risk primary BC patients who underwent AHPCT in Italy. A total of 1183 patients receiving HDC for high-risk BC (HRBC) (>3 positive nodes) were identified in the Italian registry. The median age was 46 years, 62% of patients were premenopausal at treatment, 60.1% had endocrine-responsive tumors, and 20.7% had a human epidermal growth factor receptor 2 (HER2)-positive tumor. The median number of positive lymph nodes (LN) at surgery was 15, with 71.5% of patients having ≥ 10 positive nodes. Seventy-three percent received an alkylating agent-based HDC as a single procedure, whereas 27% received epirubicin or mitoxantrone-containing HDC, usually within a multitransplantation program. The source of stem cells was peripheral blood in the vast majority of patients. Transplantation-related mortality was .8%, whereas late cardiac and secondary tumor-related mortality were around 1%, overall. With a median follow-up of 79 months, median disease-free and overall survival (OS) in the entire population were 101 and 134 months, respectively. Subgroup analysis demonstrated that OS was significantly better in patients with endocrine-responsive tumors and in patients receiving multiple transplantation procedures. HER2 status did not affect survival probability. The size of the primary tumor and number of involved LN negatively affected OS. Adjuvant HDC with AHPCT has a low mortality rate and provides impressive long-term survival rates in patients with high-risk primary BC. Our results suggest that this treatment modality should be proposed in selected HRBC patients and further investigated in clinical trials.

Y-box binding protein 1--a prognostic marker and target in tumour therapy

Y-box binding protein 1 (YB-1) is a multifunctional protein involved in various cellular processes including both transcriptional and translational regulation of target gene expression. Significantly increased YB-1 levels have been reported in a number of human malignancies and shown to be associated with poor prognosis and disease recurrence. Indeed, YB-1 can act as a versatile oncoprotein playing an important role in tumour cell proliferation and progression. Consequently, YB-1 not only proves to be a good prognostic tumour marker, but also may be a promising emerging molecular target for the development of new therapeutical strategies. In this review, we discuss both the role of YB-1 in cancer and specifically in malignant melanoma as well as possible translations into the clinics derived thereof.

Development of a Chemiluminescence Immunoassay for Serum YB-1 and its Clinical Application as a Potential Diagnostic Marker for Hepatocellular Carcinoma

BACKGROUND

Y-box binding protein 1 (YB-1) overexpression has been shown in various tumor cells including hepatocellular carcinoma (HCC); moreover, this protein can be actively secreted.

OBJECTIVES

The aim of this study was to establish a method to quantify serum YB-1 and evaluate its clinical application in the clinical diagnosis of HCC.

PATIENTS AND METHODS

Recombinant YB-1 and two populations of its antibodies were prepared. A monoclonal antibody was specific to the N-terminus of YB-1 amino acids 134-160; and another was a polyclonal antibody. A sandwich-type chemiluminescence immunoassay (CLIA) was developed and evaluated. Levels of YB-1 and alpha fetoprotein (AFP) in serum samples from 105 HCC patients, 25 hepatitis B virus patients, 25 cirrhosis patients, and 50 healthy donors were detected using the established method and an AFP electrochemiluminescence kit.

RESULTS

The developed method was linear to 150 μg/L of YB-1 with a minimum detection limit of 0.01 μg/L. The average recoveries were between 93.9% and 109.0%. The mean intra- and inter-assay coefficients of variation (CVs) were 4.0-4.8% and 8.2-10.2%, respectively. The relationship between the concentration of diluted YB-1 and the dilution ratios gave a good linear correlation coefficient of 0.9986. The YB-1 concentration was increased in serum of HCC patients (33.0 ± 23.39 μg/L) compared to healthy individuals (13.2 ± 5.29 μg/L, P < 0.0001), patients with HBV (17.9 ± 7.49 μg/L, P = 0.0003), and patients with HBV cirrhosis (20.7 ± 8.75 μg/L, P < 0.05). Moreover, the combination of YB-1 and alpha-fetoprotein had a high sensitivity (89.5%) and reasonable specificity (62.0%) in identifying HCC.

CONCLUSIONS

The established method has an acceptable performance in quantifying YB-1. In addition, serum YB-1 may aid in the diagnosis of HCC.

YB-1 immunization combined with regulatory T-cell depletion induces specific T-cell responses that protect against neuroblastoma in the early stage

Neuroblastoma is the most common extracranial solid cancer in childhood and the most common cancer in infancy. Currently, no effective clinical treatments are available for advanced neuroblastoma. In a previous study, we screened Y Box protein 1 (YB-1) as a potential neuroblastoma-associated antigen from sera of AGN2a-immunized mice by serological analysis of recombinant cDNA expression libraries technique. The aim of this study is to explore if YB-1 immunization in the context of Treg depletion could induce protective immune response against the neuroblastoma in mice. YB-1 was expressed and purified by pET-15b prokaryotic expression system. It was demonstrated that anti-YB-1 CD8(+) T-cell responses could be induced by AGN2a immunization, and the strongest CD8(+) T-cell responses against AGN2a were induced by YB-1-immunized mice in the context of Treg depletion compared with YB-1 only immunization group and control group. Importantly, the survival rate of mice treated with YB-1 immunization combined with Treg depletion was 80% when challenged by 1 × 10(4) AGN2a cells, significantly higher than that of mice immunized with YB-1 alone (P < 0.01). Furthermore, T-cell adoptive therapy showed that the neuroblastoma growth was inhibited when T cells or splenic cells from YB-1-immunized mice with Treg depletion were transferred to AGN2a bearing mice. Both CD4(+) and CD8(+) T cells were involved in the anti-neuroblastoma responses induced by YB-1 immunization combined with Treg depletion. These results indicated that YB-1 immunization combined with Treg depletion could induce specific T-cell responses against neuroblastoma and could be a potential strategy for the prevention and treatment of neuroblastoma in the early stage.

Critical issues on high-dose chemotherapy with autologous hematopoietic progenitor cell transplantation in breast cancer patients

INTRODUCTION

High-dose chemotherapy (HDC) with autologous hematopoietic progenitor cell transplantation (AHPCT) for high-risk (HR) or metastatic breast cancer (MBC) is no longer an option.

AREAS COVERED

An expert panel including medical oncologists and hematologists produce an opinion paper on the use of HDC and AHPCT in BC patients and they explain why they believe that; despite inconclusive results thus far, this treatment should have an ongoing role in breast cancer management under clinical trials.

EXPERT OPINION

HDC with AHPCT has become a safe treatment modality and an advantage in disease-free survival has been observed in most of the studies with HDC, with the caveat that today, even a limited relapse-free survival and progression-free survival benefit is sufficient for the approval of new antineoplastic agents. Moreover, in HRBC, an overall survival benefit by HDC could be achieved in the HER2-ve and triple-negative populations and, in this setting, HDC with AHPCT represents a therapeutic option that can be proposed to well-informed patients. In MBC, the HDC approach should be investigated further in selected patients with HER2-ve, chemosensitive disease. This paper is not intended to give any conclusion, but rather to open a debate on the value of HDC in HR and MBC.

Strong YB-1 expression is associated with liver metastasis progression and predicts shorter disease-free survival in advanced gastric cancer

BACKGROUND

The most significant cause of gastric cancer (GC) death is metastasis, although the underlying mechanisms remain obscure. Y-box binding protein-1 (YB-1) is associated with tumor aggressiveness and poor prognosis in various cancers. In this study we investigated the relationship between YB-1 expression and the clinicopathologic features and metastasis-associated epithelial-mesenchymal transition (EMT) phenotype in advanced GC patients.

PATIENTS AND METHODS

Immunohistochemistry (IHC) was used to analyze YB-1, E-cadherin, and vimentin expression in 98 advanced GC cases.

RESULTS

Twenty-nine (29.6%) cases of GC exhibited strong YB-1 immunoreactivity. Strong YB-1 staining occurred more often in patients with intestinal or non-scirrhous cancer, and demonstrated a significant correlation with vascular invasion (VI), liver metastasis, and shorter disease-free survival (DFS). However, we observed no relationship between YB-1 expression and EMT phenotype or overall survival. Logistic regression analysis revealed that strong staining for YB-1 was the only predictive factor for liver metastasis.

CONCLUSIONS

Our results indicate that YB-1 plays a role in the process of GC metastasis, and that the immunohistochemical detection of this protein potentially delivers valuable insight regarding the prediction of liver metastasis and shorter DFS in patients undergoing curative resection for advanced GC.

Expression of Y-box-binding protein YB-1 allows stratification into long- and short-term survivors of head and neck cancer patients

Background:

Histology-based classifications and clinical parameters of head and neck squamous cell carcinoma (HNSCC) are limited in their clinical capacity to provide information on prognosis and treatment choice of HNSCC. The primary aim of this study was to analyse Y-box-binding protein-1 (YB-1) protein expression in different grading groups of HNSCC patients, and to correlate these findings with the disease-specific survival (DSS).

Methods:

We investigated the expression and cellular localisation of the oncogenic transcription/translation factor YB-1 by immunohistochemistry on tissue micro arrays in a total of 365 HNSCC specimens and correlated expression data with clinico-pathological parameters including DSS.

Results:

Compared with control tissue from healthy individuals, a significantly (P<0.01) increased YB-1 protein expression was observed in high-grade HNSCC patients. By univariate survival data analysis, HNSCC patients with elevated YB-1 protein expression had a significantly (P<0.01) decreased DSS. By multivariate Cox regression analysis, high YB-1 expression and nuclear localisation retained its significance as a statistically independent (P<0.002) prognostic marker for DSS. Within grade 2 group of HNSCC patients, a subgroup defined by high nuclear and cytoplasmic YB-1 levels (co-expression pattern) in the cells of the tumour invasion front had a significantly poorer 5-year DSS rate of only 38% compared with overall 55% for grade 2 patients. Vice versa, the DSS rate was markedly increased to 74% for grade 2 cancer patients with low YB-1 protein expression at the same localisation.

Conclusion:

Our findings point to the fact that YB-1 expression in combination with histological classification in a double stratification strategy is superior to classical grading in the prediction of tumour progression in HNSCC.

Y-box-binding protein 1 interacts with hepatitis C virus NS3/4A and influences the equilibrium between viral RNA replication and infectious particle production

The hepatitis C virus (HCV) NS3/4A protein has several essential roles in the virus life cycle, most probably through dynamic interactions with host factors. To discover cellular cofactors that are co-opted by HCV for its replication, we elucidated the NS3/4A interactome using mass spectrometry and identified Y-box-binding protein 1 (YB-1) as an interacting partner of NS3/4A protein and HCV genomic RNA. Importantly, silencing YB-1 expression decreased viral RNA replication and severely impaired the propagation of the infectious HCV molecular clone JFH-1. Immunofluorescence studies further revealed a drastic HCV-dependent redistribution of YB-1 to the surface of the lipid droplets, an important organelle for HCV assembly. Core and NS3 protein-dependent polyprotein maturation were shown to be required for YB-1 relocalization. Unexpectedly, YB-1 knockdown cells showed the increased production of viral infectious particles while HCV RNA replication was impaired. Our data support that HCV hijacks YB-1-containing ribonucleoparticles and that YB-1-NS3/4A-HCV RNA complexes regulate the equilibrium between HCV RNA replication and viral particle production.

An integrative approach to identify YB-1-interacting proteins required for cisplatin resistance in MCF7 and MDA-MB-231 breast cancer cells

The Y-box binding protein 1 (YB-1) is a multifunctional protein that affects transcription, splicing, and translation. Overexpression of YB-1 in breast cancers causes cisplatin resistance. The exact mechanism by which YB-1 confers cisplatin resistance is unknown. The aim of the present study was to identify, using mass spectrometry, proteins that interact with YB-1 that are important for cisplatin resistance in two breast cancer cell lines, namely MCF7 and MDA-MB-231. A tagged YB-1 construct was used to identify proteins interacting directly with YB-1 in breast cancer cells. We then focused on proteins that are potentially involved in breast cancer progression based on the ONCOMINE public microarray database. Genes encoding for these YB-1-interacting proteins were examined in the public NCBI comparative genomic hybridization database to determine whether they are localized to regions of chromosomes that are rearranged in breast cancer tissues. From these analyses, we generated a list of proteins potentially involved in cisplatin resistance. Cisplatin dose-response curves were constructed in MCF7 and MDA-MB-231 transfected with four siRNA corresponding to each of these YB-1 interactors to identify proteins significantly affecting cisplatin sensitivity upon gene silencing. Depletion of only the X-linked ribosomal protein S4 (RPS4X) resulted in consistent resistance to cisplatin in both cell lines with at least three different siRNA sequences against RPS4X. Further analyses indicated that the knock down of RPS4X decreased DNA synthesis, induced cisplatin resistance, and is equivalent to the overexpression of YB-1 in both MCF7 and MDA-MB-231 cells. These results suggest that the RPS4X/YB-1 complex is a significant potential target to counteract cisplatin resistance in breast cancer.

The expression of activated Y-box binding protein-1 serine 102 mediates trastuzumab resistance in breast cancer cells by increasing CD44+ cells

The development of acquired resistance to trastuzumab remains a prevalent challenge in the treatment of patients whose tumors express human epidermal growth factor 2 (HER2). We previously reported that HER2 overexpressing breast cancers are dependent on Y-box binding protein-1 (YB-1) for growth and survival. As YB-1 is also linked to drug resistance in other types of cancer, we address its possible role in trastuzumab insensitivity. Employing an in vivo model of acquired resistance, we demonstrate that resistant cell lines have elevated levels of P-YB-1(S102) and its activating kinase P-RSK and these levels are sustained following trastuzumab treatment. Further, to demonstrate the importance of YB-1 in mediating drug resistance, the expression of the active mutant YB-1(S102D) rendered the BT474 cell line insensitive to trastuzumab. Questioning the role of tumor-initiating cells (TIC) and their ability to escape cancer therapies, we investigate YB-1's role in inducing the cancer stem cell marker CD44. Notably, the resistant cells express more CD44 mRNA and protein compared with BT474 cells, which correlated with increased mammosphere formation. Expression of YB-1(S102D) in the BT474 cells increase CD44 protein levels, resulting in enhanced mammosphere formation. Further, exposing BT474 cells to trastuzumab selected for a resistant sub-population enriched for CD44. Conversely, small intefering RNA inhibition of CD44 restored trastuzumab sensitivity in the resistant cell lines. Our findings provide insight on a novel mechanism employed by tumor cells to acquire the ability to escape the effects of trastuzumab and suggest that targeting YB-1 may overcome resistance by eliminating the unresponsive TIC population, rendering the cancer sensitive to therapy.

Emerging biomarkers in breast cancer care

Currently, decision-making for breast cancer treatment in the clinical setting is mainly based on clinical data, histomorphological features of the tumor tissue and a few cancer biomarkers such as steroid hormone receptor status (estrogen and progesterone receptors) and oncoprotein HER2 status. Although various therapeutic options were introduced into the clinic in recent decades, with the objective of improving surgery, radiotherapy, biochemotherapy and chemotherapy, varying response of individual patients to certain types of therapy and therapy resistance is still a challenge in breast cancer care. Therefore, since breast cancer treatment should be based on individual features of the patient and her tumor, tailored therapy should be an option by integrating cancer biomarkers to define patients at risk and to reliably predict their course of the disease and/or response to cancer therapy. Recently, candidate-marker approaches and genome-wide transcriptomic and epigenetic screening of different breast cancer tissues and bodily fluids resulted in new promising biomarker panels, allowing breast cancer prognosis, prediction of therapy response and monitoring of therapy efficacy. These biomarkers are now subject of validation in prospective clinical trials.