Cytoplasmic localization of SETDB1­induced Warburg effect via c­MYC­LDHA axis enhances migration and invasion in breast carcinoma.

SET domain bifurcated 1 (SETDB1), a pivotal histone lysine methyltransferase, is transported to the cytoplasm via a chromosome region maintenance 1 (CMR1)­dependent pathway, contributing to non­histone methylation. However, the function and underlying mechanism of cytoplasmic SETDB1 in breast cancer remain elusive. In the present study, immunohistochemistry revealed that elevated cytoplasmic SETDB1 was correlated with lymph node metastasis and more aggressive breast cancer subtypes. Functionally, wound healing and Transwell assays showed that cytoplasmic SETDB1 is key for cell migration and invasion, as well as induction of epithelial­mesenchymal transition (EMT), which was reversed by leptomycin B (LMB, a CMR1 inhibitor) treatment. Furthermore, RNA­seq and metabolite detection revealed that cytoplasmic SETDB1 was associated with metabolism pathway and elevated levels of metabolites involved in the Warburg effect, including glucose, pyruvate, lactate and ATP. Immunoblotting and reverse transcription­quantitative PCR verified that elevation of cytoplasmic SETDB1 contributed to elevation of c­MYC expression and subsequent upregulation of lactate dehydrogenase A (LDHA) expression. Notably, gain­ and loss­of­function approaches revealed that LDHA overexpression in T47D cells enhanced migration and invasion by inducing EMT, while its depletion in SETDB1­overexpressing MCF7 cells reversed SETDB1­induced migration and invasion, as well as the Warburg effect and EMT. In conclusion, subcellular localization of cytoplasmic SETDB1 may be a pivotal factor in breast cancer progression. The present study offers valuable insight into the novel functions and mechanisms of cytoplasmic SETDB1.

Actin filament-associated protein 1-antisense RNA1 promotes the development and invasion of tongue squamous cell carcinoma via the AFAP1-AS1/miR-133a-5p/ZIC2 axis.

BACKGROUND: The present study aimed to explore the biological role and underlying mechanism of the long non-coding RNA actin filament-associated protein 1-antisense RNA1 (lncRNA AFAP1-AS1) in the progression of tongue squamous cell carcinoma (TSCC). METHODS: A quantitative reverse transcriptase-PCR (RT-qPCR) was conducted to assess relative levels of the miR-133a-5p, lncRNAs AFAP1-AS1 and zinc finger family member 2 (ZIC2) in TSCC cell lines and specimens, whereas ZIC2 protein levels were measured using western blotting. After modifying the levels of expression of lncRNA AFP1-AS1, miR-133a-5p and ZIC2 using lentivirus or plasmid transfection, we examined AKT/epithelial-mesenchymal transition signaling pathway alterations, in vivo carcinogenesis of TSCC in nude mice and in vitro malignant phenotypes. A dual-luciferase reporter assay was conducted to confirm the targeting relationship between ZIC2 and miR-133a-5p, as well as between miR-133a-5p and lncRNA AFAP1-AS1. Based on The Cancer Genome Atlas (TCGA) database, we additionally validated AFP1-AS1. The potential biological pathway for AFP1-AS1 was investigated using gene set enrichment analysis (GSEA). We also evaluated the clinical diagnostic capacities of AFP1-AS1 and clustered the most potential biomarkers with the Mfuzz expression pattern. Finally, we also made relevant drug predictions for AFP1-AS1. RESULTS: In TSCC cell lines and specimens, lncRNA AFAP1-AS1 was upregulated. ZIC2 was upregulated in TSCC cells as a result of lncRNA AFAP1-AS1 overexpression, which also promoted TSCC cell migration, invasion, viability, and proliferation. Via the microRNA sponge effect, it was found that lncRNA AFAP1-AS1 could upregulate ZIC2 by competitively inhibiting miR-133a-5p. Interestingly, knockdown of ZIC2 reversed the biological roles of lncRNA AFAP1-AS1 with respect to inducing malignant phenotypes in TSCC cells. In addition, in vivo overexpression of lncRNA AFAP1-AS1 triggered subcutaneous tumor growth in nude mice implanted with TSCC cells and upregulated ZIC2 in the tumors. The TCGA database findings revealed that AFAP1-AS1 was significantly upregulated in TSCC specimens and had good clinical diagnostic value. The results of GSEA showed that peroxisome proliferator-activated receptor signaling pathway was significantly correlated with low expression of AFP1-AS1. Finally, the results of drug prediction indicated that the group with high AFAP1-AS1 expression was more sensitive to docetaxel, AZD4547, AZD7762 and nilotinib. CONCLUSIONS: The upregulation of lncRNA AFAP1-AS1, which increases TSCC cell viability, migration, proliferation and invasion via the AFAP1-AS1/miR-133a-5p/ZIC2 axis, aids in the progression of TSCC.

Potential Role of SWI/SNF Complex Subunit Actin-Like Protein 6A in Cervical Cancer.

SWI/SNF complex subunit Actin-like protein 6A (ACTL6A) has been regarded as an oncogene, regulating the proliferation, migration and invasion of cancer cells. However, the expression pattern and biological role of ACTL6A in cervical cancer have not been reported. In this study, the mRNA expression and protein level of ACTL6A in cervical cancer samples were determined by public database and immunohistochemical (IHC) analysis. The effects of ACTL6A on cervical cancer cells were investigated via MTT, colony-formation assay, tumor xenografts and flow cytometry. Gene set enrichment analysis (GSEA) was used to explore the potential mechanism of ACTL6A in regulating tumorigenesis of cervical cancer. The results revealed that ACTL6A was markedly upregulated in cervical cancer tissues. Silencing ACTL6A expression resulted in decreased cervical cancer cell proliferation, colony formation and tumorigenesis in vitro and in vivo. Furthermore, we demonstrated that knockdown of ACTL6A induced cell cycle arrest at G1 phase, ACTL6A-mediated proliferation and cell cycle progression were c-Myc dependent. Our study provides the role of ACTL6A in cervical oncogenesis and reveals a potential target for therapeutic intervention in this cancer type.

Transcriptome analysis of tongue cancer based on high­throughput sequencing.

Tongue cancer is one of the most common types of cancer, but its molecular etiology and pathogenesis remain unclear. The aim of the present study was to elucidate the pathogenesis of tongue cancer and investigate novel potential diagnostic and therapeutic targets. Four matched pairs of tongue cancer and paracancerous tissues were collected for RNA sequencing (RNA­Seq), and the differentially expressed genes were analyzed. The RNA­Seq data of tongue cancer tissues were further analyzed using bioinformatics and reverse transcription­quantitative PCR analysis. The sequenced reads were quantified and qualified in accordance with the analysis demands. The transcriptomes of the tongue cancer tissues and paired paracancerous tissues were analyzed, and 1,700 upregulated and 2,249 downregulated genes were identified. Gene Ontology analysis uncovered a significant enrichment in the terms associated with extracellular matrix (ECM) organization, cell adhesion and collagen catabolic processes. Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that these differentially expressed genes were mainly enriched in the focal adhesion pathway, ECM­receptor interaction pathway, phosphoinositide 3­kinase (PI3K)­Akt pathway, and cell adhesion molecules. Comprehensive analyses of the gene tree and pathway network revealed that the majority of cell cycle genes were upregulated, while the majority of the genes associated with intracellular response, cell adhesion and cell differentiation were downregulated. The ECM­receptor interaction, focal adhesion kinase (FAK) and PI3K­Akt pathways were closely associated with one another and held key positions in differential signaling pathways. The ECM­receptor, FAK and PI3K­Akt signaling pathways were found to synergistically promote tongue cancer occurrence and progression, and may serve as potential diagnostic and therapeutic targets for this type of cancer.

High Expression of SIRT1 Associates with the Doxorubicin Resistance of Breast Cancer through the Activation of Akt.

BACKGROUND AND PURPOSE: Although limited by side effects and development of resistance, doxorubicin still represents the most common chemotherapy for breast cancer. Thus, the identification of critical molecules to alleviate doxorubicin resistance is crucial. Here, we provide a molecular rationale for the breast cancer patients potentially benefitting from doxorubicin based on the expression levels of SIRT1, an identified member of longevity genes. METHODS: SIRT1-overexpressed and SIRT1-knockdown breast cancer cells were established to investigate the functions of SIRT1 in regulating doxorubicin resistance both in vitro and in vivo. Cell proliferation was analyzed via CCK8 assay, cell apoptosis was studied by TUNEL analysis. Molecule interaction was analyzed through co-immunoprecipitation and immunofluorescence techniques. Sensibility to doxorubicin was assessed in vivo through the nude mice tumorigenicity experiment. RESULTS: First, SIRT1 was found higher-expressed in breast cancer doxorubicin-resistant cells MCF-7/ADR than that in the doxorubicin- sensitive cells MCF-7. Moreover, SIRT1-knockdown MCF-7/ADR cells showed higher susceptible to doxorubicin both in vitro and in vivo models, whereas overexpressing of SIRT1 inhibited this phenotype. Accordingly, SIRT1 was found interacted with Akt, consequently promoted the activity of Akt in MCF-7/ADR cells in vitro and positively correlated with the expression of P-Akt in vivo. Reversing the activity of Akt partially downturned the doxorubicin-resistant effects mediated by SIRT1. CONCLUSION: This investigation suggested the value of SIRT1 as a biomarker of response to doxorubicin, leading to the development of new tools for the management of breast cancer patients.

ACTL6A regulates follicle-stimulating hormone-driven glycolysis in ovarian cancer cells via PGK1.

Enhanced glycolysis has been identified as a hallmark of cancer. As a novel oncogene, ACTL6A is aberrantly amplified in several types of human cancers and has been shown to regulate tumor growth and progression. However, the roles of ACTL6A in the development of ovarian cancer and the regulation of cancer glucose metabolism are mostly unknown. Here we show that ACTL6A is overexpressed in ovarian cancers compared with adjacent non-tumor tissues, and that ACTL6A overexpression correlates with poor prognosis. Silencing of ACTL6A in vitro inhibits proliferation, clonal growth, and migration, and decreases glucose utilization, lactate production, and pyruvate levels of ovarian cancer cells. We found a positive correlation between ACTL6A and PGK1 expression in ovarian cancer tissues. Enforced ACTL6A expression increased PGK1 expression, whereas knockdown of ACTL6A had the opposite effect. Altered ACTL6A expression inhibits the tumorigenicity of ovarian cancer cells in vivo by downregulating PGK1. In addition, the expression of ACTL6A is regulated by follicle-stimulating hormone (FSH) stimulation via PI3K/AKT pathway. Importantly, ACTL6A regulates FSH-enhanced glycolysis in ovarian cancer. Taken together, our findings highlight the critical role of ACTL6A in ovarian cancer development and identify its contribution to glucose metabolism of cancer cells.

Resveratrol promotes sensitization to Doxorubicin by inhibiting epithelial-mesenchymal transition and modulating SIRT1/ß-catenin signaling pathway in breast cancer.

Breast cancer is one of the leading fatal diseases for women worldwide who cannot have surgery typically have to rely on systemic chemotherapy to extend their survival. Doxorubicin (DOX) is one of the most commonly used chemotherapeutic agents against breast cancer, but acquired resistance to DOX can seriously impede the efficacy of chemotherapy, leading to poor prognosis and recurrences of cancer. Resveratrol (RES) is a phytoalexin with pharmacological antitumor properties, but its underlying mechanisms are not clearly understood in the treatment of DOX-resistant breast cancer. We used cell viability assays, cell scratch tests, and transwell assays combined with Western blotting and immunofluorescent staining to evaluate the effects of RES on chemoresistance and the epithelial-mesenchymal transitions (EMTs) in adriamycin-resistant MCF7/ADR breast cancer cells, and to investigate its underlying mechanisms. The results showed that a treatment of RES combining with DOX effectively inhibited cell growth, suppressed cell migration, and promoted cell apoptosis. RES reversed EMT properties of MCF7/ADR cells by modulating the connection between SIRT1 and ß-catenin, which provides a hopeful therapeutic avenue to conquer DOX-resistance and thereby prolong survival rates in breast cancer patients.

Nicotinamide Overcomes Doxorubicin Resistance of Breast Cancer Cells through Deregulating SIRT1/Akt Pathway.

BACKGROUND AND PURPOSE: Breast cancer is one of the leading causes of cancer deaths in female worldwide. Doxorubicin represents the most common chemotherapy for breast cancer, whereas side effects and development of resistance impede its effect on chemotherapy. Nicotinamide (NAM), serves as the sirtuins' inhibitor, effectively suppressing various types of cancer. However, the effects of NAM on drug resistance of breast cancer are need to be fully investigated. METHODS: Breast cancer doxorubicin-resistant cells MCF-7/ADR and doxorubicin-sensitive cells MCF-7 were applied in this study. Cell proliferation was assessed by CCK8 and colony-forming assays. Cell migration was evaluated by scratch test and transwell assay while cell apoptosis was measured by TUNEL analysis. Expression levels of SIRT1, phosphate Akt (P-Akt, Ser-473) and Akt were measured using western blot analysis. The interrelation between SIRT1 and Akt was investigated by co-immunoprecipitation assay. RESULTS: Treatment of nicotinamide combined with doxorubicin effectively inhibited cell growth, suppressed cell migration, and promoted cell apoptosis of MCF7/ADR cells. Mechanistically, nicotinamide translocated SIRT1 from the cell nucleus to cytoplasm, dissociated the connection between SIRT1 and Akt, and consequently decreased expressions of SIRT1, and P-Akt, thereby inhibiting the growth of MCF7/ADR cells. CONCLUSIONS: Our results suggested that the value of nicotinamide is a potential therapeutic agent for breast cancer treatment through downregulating SIRT1/Akt pathway, leading to the valid management of breast cancer patients.

AKT phosphorylation sites of Ser473 and Thr308 regulate AKT degradation.

Protein kinase B (AKT) is a serine-threonine kinase that mediates diverse cellular processes in a variety of human diseases. Phosphorylation is always the best studied posttranslational modification of AKT and a connection between phosphorylation and ubiquitination has been explored recently. Ubiquitination of AKT is an important step for its phosphorylation and activation, while whether phosphorylated AKT regulated its ubiquitination status is still unknow. In the present study, we mimic dephosphorylation of AKT by using mutagenesis techniques at both Thr308 and Ser473 into Alanine (AKT-2A). After losing phosphorylation activity, AKT enhances its degradation and prevents itself release from the plasma membrane after insulin stimulation. Fourthermore, AKT-2A is found to be degraded through ubiquitin- proteasome pathway which declared that un-phosphorylation of AKT at both Ser473 and Thr308 sites increases its ubiquitination level. In conclusion, AKT phosphorylated at Ser473 and Thr308 sites have a significant effect on its ubiquitination status. Abbreviations: AKT: Protein kinase B; Ser: serine; Thr: threonine; IF: immunofluorescence; Epo: Epoxomicin; Baf: Bafilomycin; PBS: phosphate buffer solution.

MiR-143-3p suppresses cell proliferation, migration, and invasion by targeting Melanoma-Associated Antigen A9 in laryngeal squamous cell carcinoma.

Previously we found that melanoma-associated antigen-A9 (MAGE-A9) was a significantly upregulated biomarker in laryngeal squamous cell carcinoma (LSCC). A high expression of MAGE-A9 indicates an unfavorable survival outcome, and the MAGE-A9 expression level is an independent prognostic factor of LSCC. To explore the mechanism of MAGE-A9 upregulation, several predicted regulatory microRNAs were screened and validated in LSCC cells. In the current study, we found that miR-143-3p (MAGE-A9 related miRNAs) expression levels correlated negatively with the MAGE-A9 protein expression in LSCC tissues. Dual-luciferase reporter assays and Western blot analysis revealed MAGE-A9 to be a direct target of miR-143-3p. Furthermore, a series of in vitro gain- and loss-of-function assays revealed that miR-143-3p inhibited LSCC cell proliferation, migration, and invasion. Also, miR-143-3p suppressed LSCC tumorigenesis in vivo. These effects were clinically relevant, as a lower expression of miR-143-3p occurred in severer clinical stages and represented poor overall survival in patients with LSCC. Taken together, these results suggest that downregulation of miR-143-3p contributes to tumor progression through upregulation of MAGE-A9. The expression level of these two key molecules maintained LSCC progression, thus, highlighting the potential of miR-143-3p as a therapeutic target for human LSCC.

SIRT1 promotes formation of breast cancer through modulating Akt activity.

The silent information regulation factor 1 (sirtuin Type 1, SIRT1), as a kind of NAD+ dependent class III histone deacetylation enzyme, has been found to be involved in tumor proliferation, invasion, and metastasis. The roles of SIRTl in breast cancer is multifaceted depending on its substrate from upstream or downstream signaling pathway. In this study, we sought to make clear the regulating effects of SIRT1 in breast cancer cells, and to explore the underlying mechanisms through which SIRT1 regulates breast cancer. First, our results showed that SIRT1 was significantly up-regulated in breast cancer tissues and cells, which correlated with histological grade, tumor size, as well as lymph node metastasis. Then we established SIRT1-overexpressed and SIRT1- knockdown breast cancer cell lines to investigate the functions of SIRT1 in regulating colony formation, cell proliferation, cell cycle, cell apoptosis and migration. We found that overexpression of SIRT1 significantly promoted breast cancer growth both in vitro and in vivo, whereas knockdown of SIRT1 inhibited these phenotypes. Furthermore, SIRT1 was found to interact with Akt directly, consequently promoting the activity of Akt in breast cancer cells in vitro and positively correlating with expression of Akt, P-Akt, in breast cancer tissues in vivo. Down regulation the activity of Akt partially weakened the proliferative effect mediated by SIRT1. Taken together, our results demonstrated SIRT1's tumor promotion function and potential mechanisms in breast cancer, thus providing valuable therapeutic targets for breast cancer.

MiR-650 represses high-risk non-metastatic colorectal cancer progression via inhibition of AKT2/GSK3ß/E-cadherin pathway.

Although 5-year survival rate of non-metastatic colorectal cancer (CRC) is high, about 10% of patients in stage I and II still develop into metastatic CRC and eventually die after resection. Currently, there is no effective biomarker for predicting the prognosis of non-metastatic CRC in clinical practice. In this study, we identified miR-650 as a biomarker for prognosis prediction. We observed that the expression of miR-650 in tumor tissues had a positive association with overall survival. MiR-650 inhibited cell growth and invasion in vitro and in vivo. Furthermore, miR-650 targeted AKT2 and repressed the activation of the AKT pathway (AKT2/GSK3ß/E-cadherin). Thus it induced the translocation of E-cadherin and ß-catenin in cancer cells. Our results highlight the potential of miR-650 as a prognostic prediction biomarker and therapeutic target in non-metastatic CRC via inhibition of the AKT2/GSK3ß/E-cadherin pathway.

Combined Knockdown of D-dopachrome Tautomerase and Migration Inhibitory Factor Inhibits the Proliferation, Migration, and Invasion in Human Cervical Cancer.

OBJECTIVE: D-dopachrome tautomerase (D-DT) is a homologue of macrophage migration inhibitory factor (MIF) with similar functions. However, the possible biological roles of D-DT in cervical cancer remain unknown so far. METHODS: D-dopachrome tautomerase was assessed by immunohistochemistry in 83 cervical cancer and 31 normal cervix tissues. The stable knockdown of D-DT and MIF by lentivirus-delivered short hairpin RNA was established, and tumor growth was examined in vitro and in vivo. The effects of D-DT and MIF on the migration and invasion were further detected by wound healing assay and transwell assay. Western blot was used to explore the mechanism of D-DT and MIF in cervical cancer pathogenesis. RESULTS: We found that D-DT was significantly high in cervical cancer, which correlated with lymph node metastasis. The knockdown of D-DT and MIF, individually and additively, inhibited the proliferation, migration, and invasion in HeLa and SiHa cells and restrained the growth of xenograft tumor. The ablation of D-DT and MIF rescued the expression of E-cadherin and inhibited the expression of PCNA, cyclin D1, gankyrin, Sam68, and vimentin, as well as phospho-Akt and phospho-glycogen synthase kinase 3-ß. CONCLUSIONS: The inhibition of D-DT and MIF in combination may represent a potential therapeutic strategy for cervical cancer.

PA-MSHA inhibits the growth of doxorubicin-resistant MCF-7/ADR human breast cancer cells by downregulating Nrf2/p62.

Acquired resistance to doxorubicin in breast cancer is a serious therapeutic problem. In this study, we investigated whether Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) could inhibit the growth of doxorubicin-resistant breast cancer cells. We found that the expressions of Nrf2 and p62 in breast cancer were higher than that in the corresponding adjacent normal tissues and benign breast epithelial cell. The expressions of Nrf2 and p62 in breast cancer doxorubicin-resistant cells MCF-7/ADR were higher than that in doxorubicin-sensitive cells MCF-7. Silencing of Nrf2 or p62 rendered breast cancer cells more susceptible to doxorubicin. We further demonstrated that PA-MSHA inhibited growth and induced apoptosis of MCF-7/ADR cells but not MCF-7 cells. Subcutaneous administration of PA-MSHA greatly inhibited the growth of xenograft tumors from MCF-7/ADR cells in nude mice. In addition, PA-MSHA could downregulate Nrf2 and p62 in vitro and in vivo. These results suggested that activation of Nrf2 and p62 was associated with doxorubicin resistance in breast cancer. PA-MSHA could inhibit the growth of doxorubicin-resistant MCF-7/ADR cells and its potential mechanism might be due to the suppression of Nrf2/p62. It indicated the possibility of using PA-MSHA in doxorubicin-resistant breast cancer.

Activation of AKT pathway by Nrf2/PDGFA feedback loop contributes to HCC progression.

Nuclear factor erythroid-2-related factor 2 (Nrf2), a master transcription factor in the antioxidant response, has been found to be ubiquitously expressed in various cancer cells and in the regulation tumor proliferation, invasion, and chemoresistance activities. The regulatory roles of Nrf2 in controlling Hepatocellular carcinoma (HCC) progression remain unclear. In this study, we demonstrated that Nrf2 was significantly elevated in HCC cells and tissues and was correlated with poor prognosis of HCCs. Consistently, Nrf2 significantly promoted HCC cell growth both in vitro and in vivo. Further investigation suggested a novel association of Nrf2 with Platelet-Derived Growth Factor-A (PDGFA). Nrf2 promoted PDGFA transcription by recruiting specificity protein 1 (Sp1) to its promoter, resulting in increased activation of the AKT/p21 pathway and cell cycle progression of HCC cells. As a feedback loop, PDGFA enhanced Nrf2 expression and activation in an AKT dependent manner. In line with these findings, expression of Nrf2 and PDGFA were positively correlated in HCC tissues. Taken together, this study uncovers a novel mechanism of the Nrf2/PDGFA regulatory loop that is crucial for AKT-dependent HCC progression, and thereby provides potential targets for HCC therapy.

The role of the Chaperonin containing t-complex polypeptide 1, subunit 8 (CCT8) in B-cell non-Hodgkin's lymphoma.

The chaperonin containing t-complex polypeptide 1 (CCT) is known to mediate folding of proteins. CCT, subunit 8 (CCT8), is the θ subunit of CCT complex chaperonin. CCT8 has been reported to be dysregulated in several tumor tissues. In this study, we investigated the role of CCT8 in B-cell non-Hodgkin's lymphoma (NHL). Clinically, the expression levels of CCT8 in reactive lymphoid hyperplasia (RLH) and B-cell NHL specimens were investigated using immunohistochemical analysis. We found that CCT8 was highly expressed in proliferating germinal center cells compared with the quiescent cells of the follicular mantle zone. Furthermore, CCT8 was highly expressed in progressive lymphomas than in indolent lymphomas. Kaplan-Meier curve showed that high expression of CCT8 was significantly associated with shorter overall survival in patients with diffuse large B-cell lymphoma. Moreover, we demonstrated that CCT8 could promote the proliferation of B-cell NHL cells. In addition, we found that CCT8 could accelerate the G1/S transition in B-cell NHL. Finally, we demonstrated that overexpression of CCT8 could reverse cell adhesion-mediated drug resistance (CAM-DR) phenotype. Our study may shed new insights into the important role of CCT8 in cancer development.

Synergistic effects of c-Jun and SP1 in the promotion of TGFß1-mediated diabetic nephropathy progression.

Diabetic nephropathy (DN) is a major complication of diabetes mellitus. Transforming growth factor beta 1 (TGFß1) is a well-distinguished mediator of progressive renal fibrosis in DN. However, the molecular mechanisms contributing to enhanced TGFß1 expression in the progression of DN are not fully understood. Herein, we reported that c-Jun and specificity protein 1 (SP1) were critical upstream regulators of TGFß1 expression in DN. The increase in c-Jun and SP1 expressions was positively correlated with TGFß1 in both high glucose-treated human renal mesangial cells (HRMCs) and diabetic kidneys. Furthermore, c-Jun dose-dependently promoted SP1-mediated TGFß1 transcription and vice versa. The synergistic effects of c-Jun and SP1 were attributed to their auto-regulation and cross-activation. Moreover, enhanced phosphorylation levels of c-Jun and SP1 were accompanied with increased TGFß1 expression in diabetic kidneys. Accordingly, dephosphorylation of c-Jun and SP1 by the specific c-Jun N-terminal kinase (JNK) inhibitor SP600125 prevented the increase in TGFß1 expression. These results suggested that c-Jun and SP1 synergistically activated profibrotic TGFß1 expression in the development of DN by auto-regulation, cross-activation and phospho-modification.

Overexpression of HOXC8 is Associated With Poor Prognosis in Epithelial Ovarian Cancer.

Homeobox C8 (HOXC8) is a transcription factor that has been reported as a potential driver oncogene in several tumors and involved in the regulation of many cancer-related proteins. In this study, we investigated the expression and role of HOXC8 in ovarian cancer. Western blot and immunohistochemistry analyses were performed to detect the expression of HOXC8. Kaplan-Meier curve showed that high expression of HOXC8 was related to poor prognosis of patients with epithelial ovarian cancer (EOC). Starvation and refeeding assay were used to assess cell cycle, suggesting that HOXC8 played a critical role in EOC cell proliferation. HOXC8 depletion by small interfering RNA inhibited cell proliferation, migration, and induced apoptosis in EOC cells. Moreover, HOXC8 knockdown increased the expression of ZAC1. Owing to the overexpression of HOXC8, our findings implied that HOXC8 is involved in the progression of EOC and could be a potential therapeutical approach of EOC.

Spy1 participates in the proliferation and apoptosis of epithelial ovarian cancer.

This study focused on determining the role of Spy1 in human epithelial ovarian cancer (EOC). Speedy is a novel cell cycle protein capable of promoting cell proliferation. In this study, western blot and immunohistochemistrical analyses were performed to detect the expression of Spy1 in ovarian cancer. Spy1 protein levels increased with ovarian cancer grade, and Kaplan-Meier curve showed that overexpression of Spy1 was significantly correlated with reduced patient survival. In vitro, Spy1 depletion in ovarian cell lines led to reduced proliferation according to CCK8 and plate colony assays. The expression of Spy1 was positively related to pThr187-p27. Flow cytometry revealed that the reduced expression of Spy1 induced the apoptosis of the EOC cells. In summary, our findings suggested that Spy1 may be a novel independent prognostic predictor of survival for ovarian patients.

Nrf2 ameliorates diabetic nephropathy progression by transcriptional repression of TGFß1 through interactions with c-Jun and SP1.

Diabetic nephropathy (DN) is one of the major complications in diabetes patients. Reactive oxygen species (ROS) play key roles in DN progression. As a primary transcription factor, Nrf2 controls the antioxidant response to maintain cellular redox homeostasis. Herein we systemically examined the role of Nrf2 in DN progression and its regulatory mechanism in a mouse model bearing type II diabetes and in cultured human renal mesangial cells (HRMCs). We found that Nrf2 could ameliorate DN progression by transcriptional repression of TGFß1 in vivo and in vitro. Moreover, Nrf2 bound to the specific region in TGFß1 promoter by interactions with transcription factors c-Jun and SP1. Significant abolishment of Nrf2-mediated TGFß1 transcriptional repression could be accomplished by knockdown of either c-Jun or SP1, and site-directed mutagenesis of c-Jun and SP1 binding sites in the TGFß1 promoter specific region. Moreover, after interacting with c-Jun and SP1, Nrf2 inhibited c-Jun and SP1 activations, and thus reversed c-Jun- and SP1-promoted TGFß1 transcription. In all, Nrf2 could slow down DN progression by repression of TGFß1 in a c-Jun and SP1-dependent way. Our findings may provide novel clues for DN preventions and interventions in clinic.