BAG-1/SODD, HSP70, and HSP90 are potential prognostic markers of poor survival in node-negative breast carcinoma

The Bcl-2-associated athanogene gene family in tobacco (Nicotiana tabacum) and the function of NtBAG5 in leaf senescence

Leaf senescence in tobacco is closely related to leaf maturation and secondary metabolites. Bcl-2-associated athanogene (BAG) family members are highly conserved proteins and play key roles in senescence, growth and development, and resistance to biotic and abiotic stresses. Herein, the BAG family of tobacco was identified and characterized. In total, 19 tobacco BAG protein candidate genes were identified and divided into two classes, class I comprising NtBAG1a-e, NtBAG3a-b, and NtBAG4a-c and class II including NtBAG5a-e, NtBAG6a-b, and NtBAG7. Genes in the same subfamily or branch of the phylogenetic tree exhibited similarities in gene structure and the cis-element on promoters. RNA-seq and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that the expression of NtBAG5c-f and NtBAG6a-b was upregulated in senescent leaves, implying that they play a role in regulating leaf senescence. NtBAG5c was localized in the nucleus and cell wall as a homology of leaf senescence related gene AtBAG5. Further, the interaction of NtBAG5c with heat-shock protein 70 (HSP70) and sHSP20 was demonstrated using yeast two-hybrid experiment. Virus-induced gene silencing indicated that NtBAG5c reduced the lignin content and increased superoxide dismutase (SOD) activity and hydrogen peroxide (H₂O₂) accumulation. In NtBAG5c-silenced plants, the expression of multiple senescence-related genes cysteine proteinase (NtCP1), SENESCENCE 4 (SEN4) and SENESCENCE-ASSOCIATED GENE 12 (SAG12) was downregulated. In conclusion, tobacco BAG protein candidate genes were identified and characterized for the first time.

The circulating 70 kDa heat shock protein (HSPA1A) level is a potential biomarker for breast carcinoma and its progression

The early diagnosis of breast cancer can improve treatment and prognosis. We sought to evaluate whether the serum concentration of the 70 kDa heat shock protein (HSPA1A) was elevated in Brazilian women with breast cancer, and if levels correlated with tumor characteristics. This was a cross-sectional, analytical, case–control exploratory study performed at The University of São Paulo School of Medicine. From September 2017 to December 2018, 68 women with breast cancer and 59 controls were recruited. The HSPA1A concentration in serum samples was determined by ELISA by individuals blinded to the clinical data. The mean ages in the study and control groups were 54.9 and 52.0 years, respectively. The median serum levels of HSPA1A were elevated in women with breast cancer (1037 pg/ml) compared with controls (300 pg/ml) (p < 0.001). Elevated HSPA1A levels were associated with advanced histological tumor grade (p < 0.001) and with the cell proliferation index (KI67) (p = 0.0418). The HSPA1A concentration was similar in women with different histological subtypes, nuclear grade, hormone receptor expression, HER2 status and the presence or absence of angiolymphatic invasion. Elevated serum HSPA1A in Brazilian women with advanced histological grade and proliferation index breast cancer supports the potential value of additional investigation on larger and more varied populations to verify the value of HSPA1A detection as a component of breast cancer diagnosis and progression.

HSP70s in Breast Cancer: Promoters of Tumorigenesis and Potential Targets/Tools for Therapy

The high frequency of breast cancer worldwide and the high mortality among women with this malignancy are a serious challenge for modern medicine. A deeper understanding of the mechanisms of carcinogenesis and emergence of metastatic, therapy-resistant breast cancers would help development of novel approaches to better treatment of this disease. The review is dedicated to the role of members of the heat shock protein 70 subfamily (HSP70s or HSPA), mainly inducible HSP70, glucose-regulated protein 78 (GRP78 or HSPA5) and GRP75 (HSPA9 or mortalin), in the development and pathogenesis of breast cancer. Various HSP70-mediated cellular mechanisms and pathways which contribute to the oncogenic transformation of mammary gland epithelium are reviewed, as well as their role in the development of human breast carcinomas with invasive, metastatic traits along with the resistance to host immunity and conventional therapeutics. Additionally, intracellular and cell surface HSP70s are considered as potential targets for therapy or sensitization of breast cancer. We also discuss a clinical implication of Hsp70s and approaches to targeting breast cancer with gene vectors or nanoparticles downregulating HSP70s, natural or synthetic (small molecule) inhibitors of HSP70s, HSP70-binding antibodies, HSP70-derived peptides, and HSP70-based vaccines.

Bcl2-associated athanogene 4 promotes the invasion and metastasis of gastric cancer cells by activating the PI3K/AKT/NF-κB/ZEB1 axis

Bcl2-associated athanogene 4 (BAG4) has been found to be aberrantly expressed in several types of human cancers. However, little is known about its expression, role, and clinical significance in gastric cancer (GC). In this study, we aimed to address these issues and to explore the underlying mechanisms. The expression level of BAG4, measured by immunohistochemistry, was significantly higher in GC tissues than in paired normal tissues. Elevated BAG4 expression was positively correlated with T stage, lymph node metastasis, and tumor size of GC and was associated with unfavorable outcomes of the patients. The overexpression of BAG4 promoted the in vitro invasion and in vivo metastasis of GC cells, and opposite results were observed after silencing of BAG4. Silencing of BAG4 significantly reduced the phosphorylation of PI3K, AKT, and p65, whereas overexpression of BAG4 markedly enhanced the phosphorylation of these molecules. At the same time, manipulating BAG4 expression resulted in the corresponding changes in p65 nuclear translocation and ZEB1 expression. Luciferase reporter and chromatin immunoprecipitation assays verified that p65 binds to the promoter of ZEB1 to upregulate its transcription. Our results demonstrate that BAG4 plays an oncogenic role in the invasion and metastasis of GC cells by activating the PI3K/AKT/NF-κB/ZEB1 axis to induce epithelial-mesenchymal transition.

Abscopal Effects in Metastatic Cancer: Is a Predictive Approach Possible to Improve Individual Outcomes?

Patients with metastatic cancers often require radiotherapy (RT) as a palliative therapy for cancer pain. RT can, however, also induce systemic antitumor effects outside of the irradiated field (abscopal effects) in various cancer entities. The occurrence of the abscopal effect is associated with a specific immunological activation in response to RT-induced cell death, which is mainly seen under concomitant immune checkpoint blockade. Even if the number of reported apscopal effects has increased since the introduction of immune checkpoint inhibition, its occurrence is still considered rare and unpredictable. The cases reported so far may nevertheless allow for identifying first biomarkers and clinical patterns. We here review biomarkers that may be helpful to predict the occurrence of abscopal effects and hence to optimize therapy for patients with metastatic cancers.

SNX-2112 Induces Apoptosis and Inhibits Proliferation, Invasion, and Migration of Non-Small Cell Lung Cancer by Downregulating Epithelial-Mesenchymal Transition via the Wnt/β-Catenin Signaling Pathway

Lung cancer is the most frequent malignant tumor, and non-small cell lung cancer (NSCLC) is responsible for substantial mortality worldwide. The small molecule SNX-2112 was recently shown to critically effect the proliferation and apoptosis of tumor cells. Nevertheless, the precise mechanism by which SNX-2112 affects NSCLC remains poorly understood. Therefore, we investigated the function of SNX-2112 in NSCLC. We verified that SNX-2112 promoted apoptosis and suppressed the proliferation, invasion, and migration of A549 and H520 NSCLC cells in vitro. We further verified the potential mechanism of SNX-2112 in NSCLC. The changes in the protein levels demonstrated that SNX-2112 inhibited the epithelial-mesenchymal transition (EMT) (increased E-cadherin and decreased N-cadherin and vimentin) and the Wnt/β-catenin signaling pathway (glycogen synthase kinase (GSK) 3β and phosphorylated (p)-β-catenin increased, β-catenin and p-GSK3β decreased) in NSCLC cells. These results were verified by rescue experiments using a Wnt/β-catenin pathway agonist. We also established a tumor xenograft model and confirmed that SNX-2112 reduced tumor growth and proliferation and enhanced necrosis and apoptosis in a NSCLC model in vivo. In conclusion, the current study is the first to discover the mechanism of SNX-2112 in NSCLC. SNX-2112 induced apoptosis and also inhibited the proliferation, invasion, and migration of NSCLC cells by downregulating EMT via the Wnt/β-catenin signaling pathway.

Expression of BAG1 is associated with prognosis in kidney renal clear cell carcinoma based on bioinformatics

Background

BCL2 associated Athano-Gene 1 (BAG1) has been described to be involved in the development and progression of cancer. But the role of BAG1 in kidney renal clear cell carcinoma (KIRC) has remained largely unknown.

Methods

We performed bioinformatic analysis of data from TCGA and GEO dataset. The role of BAG1 in KIRC was explored by Logistic and Cox regression model. The molecular mechanisms of BAG1 was revealed by GSEA.

Results

The current study found that the KIRC tumor samples have a low level of BAG1 mRNA expression compared to the matched normal tissues based on TCGA data and GEO databases. Low expression of BAG1 in KIRC was significantly associated with Sex, clinical pathological stage, tumor-node-metastasis (TNM) stage, hemoglobin levels, cancer status and history of neoadjuvant treatment. Kaplan-Meier survival analysis indicated that KIRC patients with BAG1 high expression have a longer survival time than those with BAG1 low expression (p < 0.000). Cox regression analysis showed that BAG1 remained independently associated with overall survival, with a hazard ratio (HR) of 1.75(CI:1.05–2.90; p = 0.029). GSEA indicated that the signaling pathways including fatty acid metabolism and oxidative phosphorylation were differentially enriched in high BAG1 expression phenotype.

Conclusions

These findings suggested that BAG1 expression may act as a potential favorable prognostic marker and challenging therapeutic target.

Cytosolic Hsp70 as a biomarker to predict clinical outcome in patients with glioblastoma

INTRODUCTION

The major stress-inducible heat shock protein 70 (Hsp70) is induced after different stress stimuli. In tumors, elevated intracellular Hsp70 levels were associated on the one hand with radio- and chemotherapy resistance and on the other hand with a favorable outcome for patients. This study was undertaken to investigate cytosolic Hsp70 (cHsp70) as a potential biomarker for progression free (PFS) and overall survival (OS) in patients with primary glioblastomas (GBM).

METHODS

The cHsp70 expression in tumor tissue of 60 patients diagnosed with primary GBM was analyzed by immunohistochemistry. The cHsp70 expression was correlated to the PFS and OS of the patients.

RESULTS

A high cHsp70 expression was associated with a prolonged PFS (hazard ratio = 0.374, p = 0.001) and OS (hazard ratio = 0.416, p = 0.014) in GBM patients treated according to the standard Stupp protocol with surgery, radiotherapy and temozolomide.

CONCLUSIONS

These data suggest that the intracellular Hsp70 expression might serve as a prognostic marker in patients with primary GBM.

Hyperphosphorylation of RPS6KB1, rather than overexpression, predicts worse prognosis in non-small cell lung cancer patients

RPS6KB1 is the kinase of ribosomal protein S6 which is 70 kDa and is required for protein translation. Although the abnormal activation of RPS6KB1 has been found in types of diseases, its role and clinical significance in non-small cell lung cancer (NSCLC) has not been fully investigated. In this study, we identified that RPS6KB1 was over-phosphorylated (p-RPS6KB1) in NSCLC and it was an independent unfavorable prognostic marker for NSCLC patients. In spite of the frequent expression of total RPS6KB1 and p-RPS6KB1 in NSCLC specimens by immunohistochemical staining (IHC), only p-RPS6KB1 was associated with the clinicopathologic characteristics of NSCLC subjects. Kaplan-Meier survival analysis revealed that the increased expression of p-RPS6KB1 indicated a poorer 5-year overall survival (OS) for NSCLC patients, while the difference between the positive or negative RPS6KB1 group was not significant. Univariate and multivariate Cox regression analysis was then used to confirm the independent prognostic value of p-RPS6KB1. To illustrate the underlying mechanism of RPS6KB1 phosphorylation in NSCLC, LY2584702 was employed to inhibit the RPS6KB1 phosphorylation specifically both in lung adenocarcinoma cell line A549 and squamous cell carcinoma cell line SK-MES-1. As expected, RPS6KB1 dephosphorylation remarkably suppressed cells proliferation in CCK-8 test, and promoted more cells arresting in G0-G1 phase by cell cycle analysis. Moreover, apoptotic A549 cells with RPS6KB1 dephosphorylation increased dramatically, with an elevating trend in SK-MES-1, indicating a potential involvement of RPS6KB1 phosphorylation in inducing apoptosis. In conclusion, our data suggest that RPS6KB1 is over-activated as p-RPS6KB1 in NSCLC, rather than just the total protein overexpressing. The phosphorylation level of RPS6KB1 might be used as a novel prognostic marker for NSCLC patients.

BAG-1 as a biomarker in early breast cancer prognosis: a systematic review with meta-analyses

BACKGROUND

The co-chaperone protein Bcl-2-associated athanogene-1 (BAG-1) is overexpressed in breast cancer and has been incorporated in the oncotype DX and PAM50 breast cancer prognostic assays. Bcl-2-associated athanogene-1 exists as multiple protein isoforms that interact with diverse partners, including chaperones Hsc70/Hsp70, Ser/Thr kinase Raf-1 and Bcl-2, to promote cancer cell survival. The BAG-1L isoform specifically binds to and increases the transcriptional activity of oestrogen receptor in cells, and in some, but not all studies, BAG-1 expression is predictive of clinical outcome in breast cancer.

METHODS

A systematic review of published studies reporting BAG-1 (mRNA and/or protein) expression and clinical outcome in early breast cancer. The REporting Recommendations for Tumour MARKer and Prognostic Studies (REMARK) criteria were used as a template against which data were assessed. Meta-analyses were performed for studies that provided a hazard ratio and 95% confidence intervals for clinical outcomes including disease-free survival or breast cancer-specific survival from univariate analysis.

RESULTS

Eighteen studies used differing methodologies and reported on differing outcomes. Meta-analyses were only possible on results from a subset of reported studies. Meta-analyses suggested improved outcome with high BAG-1 mRNA and high BAG-1 nuclear expression by immunohistochemisty.

CONCLUSIONS

Increased levels of BAG-1 are associated with better breast cancer outcomes.