Tubulin cofactor A functions as a novel positive regulator of ccRCC progression, invasion and metastasis

Recruitment of BAG2 to DNAJ-PKAc scaffolds promotes cell survival and resistance to drug-induced apoptosis in fibrolamellar carcinoma

The DNAJ-PKAc fusion kinase is a defining feature of fibrolamellar carcinoma (FLC). FLC tumors are notoriously resistant to standard chemotherapies, with aberrant kinase activity assumed to be a contributing factor. By combining proximity proteomics, biochemical analyses, and live-cell photoactivation microscopy, we demonstrate that DNAJ-PKAc is not constrained by A-kinase anchoring proteins. Consequently, the fusion kinase phosphorylates a unique array of substrates, including proteins involved in translation and the anti-apoptotic factor Bcl-2-associated athanogene 2 (BAG2), a co-chaperone recruited to the fusion kinase through association with Hsp70. Tissue samples from patients with FLC exhibit increased levels of BAG2 in primary and metastatic tumors. Furthermore, drug studies implicate the DNAJ-PKAc/Hsp70/BAG2 axis in potentiating chemotherapeutic resistance. We find that the Bcl-2 inhibitor navitoclax enhances sensitivity to etoposide-induced apoptosis in cells expressing DNAJ-PKAc. Thus, our work indicates BAG2 as a marker for advanced FLC and a chemotherapeutic resistance factor in DNAJ-PKAc signaling scaffolds.

Recruitment of BAG2 to DNAJ-PKAc scaffolds promotes cell survival and resistance to drug-induced apoptosis in fibrolamellar carcinoma

The DNAJ-PKAc fusion kinase is a defining feature of the adolescent liver cancer fibrolamellar carcinoma (FLC). A single lesion on chromosome 19 generates this mutant kinase by creating a fused gene encoding the chaperonin binding domain of Hsp40 (DNAJ) in frame with the catalytic core of protein kinase A (PKAc). FLC tumors are notoriously resistant to standard chemotherapies. Aberrant kinase activity is assumed to be a contributing factor. Yet recruitment of binding partners, such as the chaperone Hsp70, implies that the scaffolding function of DNAJ- PKAc may also underlie pathogenesis. By combining proximity proteomics with biochemical analyses and photoactivation live-cell imaging we demonstrate that DNAJ-PKAc is not constrained by A-kinase anchoring proteins. Consequently, the fusion kinase phosphorylates a unique array of substrates. One validated DNAJ-PKAc target is the Bcl-2 associated athanogene 2 (BAG2), a co-chaperone recruited to the fusion kinase through association with Hsp70. Immunoblot and immunohistochemical analyses of FLC patient samples correlate increased levels of BAG2 with advanced disease and metastatic recurrences. BAG2 is linked to Bcl-2, an anti-apoptotic factor that delays cell death. Pharmacological approaches tested if the DNAJ- PKAc/Hsp70/BAG2 axis contributes to chemotherapeutic resistance in AML12 DNAJ-PKAc hepatocyte cell lines using the DNA damaging agent etoposide and the Bcl-2 inhibitor navitoclax. Wildtype AML12 cells were susceptible to each drug alone and in combination. In contrast, AML12 DNAJ-PKAc cells were moderately affected by etoposide, resistant to navitoclax, but markedly susceptible to the drug combination. These studies implicate BAG2 as a biomarker for advanced FLC and a chemotherapeutic resistance factor in DNAJ-PKAc signaling scaffolds.

Hypermethylation of the Promoter of miR-338-5p Mediates Aberrant Expression of ETS-1 and Is Correlated With Disease Severity Of Astrocytoma Patients

The pro-oncogene ETS-1 (E26 transformation-specific sequence 1) is a key regulator of the proliferation and invasion of cancer cells. The present work examined the correlation of the aberrant expression of ETS-1 with histological or clinical classification of astrocytoma: grade I (pilocytic astrocytoma), grade II (diffuse astrocytoma), grade III (anaplastic astrocytoma), and grade IV (glioblastoma multiforme). MicroRNA, miR-338-5p, was predicted by an online tool (miRDB) to potentially target the 3’ untranslated region of ETS-1; this was confirmed by multi-assays, including western blot experiments or the point mutation of the targeting sites of miR-338-5p in ETS-1’s 3’untralation region (3’UTR). The expression of miR-338-5p was negatively associated with that of ETS-1 in astrocytoma, and deficiency of miR-338-5p would mediate aberrant expression of ETS-1 in astrocytoma. Mechanistically, hypermethylation of miR-338-5p by DNA methyltransferase 1 (DNMT1) resulted in repression of miR-338-5p expression and the aberrant expression of ETS-1. Knockdown or deactivation of DNMT1 decreased the methylation rate of the miR-338-5p promoter, increased the expression of miR-338-5p, and repressed the expression of ETS-1 in astrocytoma cell lines U251 and U87. These results indicate that hypermethylation of the miR-338-5p promoter by DNMT1 mediates the aberrant expression of ETS-1 related to disease severity of patients with astrocytoma.

Comprehensive analysis of lncRNAs as biomarkers for diagnosis, prognosis, and treatment response in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological type of renal carcinoma and has a high recurrence rate and poor outcome. Accurate patient risk stratification based on genetic markers can help to identify the high-risk patient for early and further treatments and would promote patient survival. Long non-coding RNAs (lncRNAs) have attracted widespread attention as biomarkers for early diagnosis, treatment, and prognosis because of their high specificity and sensitivity. Here, we performed a systematic search in NCBI PubMed and found 44 lncRNAs as oncogenes, 18 lncRNAs as tumor suppressors, 199 lncRNAs as diagnostic biomarkers, 62 lncRNAs as prognostic biomarkers, and 3 lncRNAs as predictive biomarkers for ccRCC. We also comprehensively discuss the biological functions and molecular regulatory mechanisms of lncRNAs in ccRCC. Overall, the present study is a systemic analysis to assess the expression and clinical value of lncRNAs in ccRCC, and lncRNAs hold promise to be diagnostic, prognostic, and predictive biomarkers.

LncRNA SNHG17 Contributes to Proliferation, Migration, and Poor Prognosis of Hepatocellular Carcinoma

Long noncoding RNAs (lncRNAs) have been substantially reported to have critical roles in regulating tumorigenesis in recent years. However, the expression pattern and biological function of SNHG17 in hepatocellular carcinoma (HCC) remain unclear. Bioinformatics analysis and qRT-PCR were performed to detect the expression pattern of SNHG17 in HCC tissues, adjacent nontumorous tissues, and cell lines. The effect of SNHG17 on proliferation, migration, and apoptosis of HCC was investigated by knockdown and overexpressing SNHG17 in HCC cell lines. RNA sequencing was utilized to explore the underlying mechanism. Utilizing publicly available TCGA-LIHC, GSE102079 HCC datasets, and qRT-PCR, we found SNHG17 was significantly upregulated in HCC tissues and cell lines and was notably associated with larger tumor size, poorly differentiation, presence of vascular invasion, and advanced TNM stage. Furthermore, gain- and loss-of-function studies demonstrated that SNHG17 promoted cell proliferation and migration and inhibited apoptosis of HCC. By employing RNA sequencing, we found knockdown of SNHG17 caused 1037 differentially expressed genes, highly enriched in several pathways, including metabolic, PI3K-Akt, cell adhesion, regulation of cell proliferation, and apoptotic pathway; among them, 92 were overlapped with SNHG17-related genes in the TCGA-LIHC dataset. Furthermore, ERH, TBCA, TDO2, and PDK4 were successfully validated and found significantly dysregulated in HCC tissues. Moreover, HCC patients with higher SNHG17 expression had a relatively poor overall survival and disease-free survival, and ERH and PDK4 also played a marked role in the prognosis of HCC. Broadly, our findings illustrate that SNHG17 acts as a noncoding oncogene in HCC progression, suggesting its potential value as a novel target for HCC therapy.

TPX2 Enhanced the Activation of the HGF/ETS-1 Pathway and Increased the Invasion of Endocrine-Independent Prostate Carcinoma Cells

The prognosis for endocrine-independent prostate carcinoma is still poor due to its highly metastatic feature. In the present work, TPX2 (the targeting protein for Xklp2), which is known as a micro-tubulin interacted protein, was identified as a novel coactivator of ETS-1, a transcription factor that plays a central role in mediating the metastasis of human malignancies. TPX2 enhanced the transcription factor activation of ETS-1 and increased the expression of ETS-1's downstream metastasis-related genes, such as mmp3 or mmp9, induced by HGF (hepatocyte growth factor), a typical agonist of the HGF/c-MET/ETS-1 pathway. The protein-interaction between TPX2 and ETS-1 was examined using immunoprecipitation (IP). TPX2 enhanced the accumulation of ETS-1 in the nuclear and the recruitment of its binding element (EST binding site, EBS) located in the promoter region of its downstream gene, mmp9. Moreover, TPX2 enhanced the in vitro or in vivo invasion of a typical endocrine-independent prostate carcinoma cell line, PC-3. Therefore, TPX2 enhanced the activation of the HGF/ETS-1 pathway to enhance the invasion of endocrine-independent prostate carcinoma cells and thus it would be a promising target for prostate carcinoma treatment.

Colchicine Blocks Tubulin Heterodimer Recycling by Tubulin Cofactors TBCA, TBCB, and TBCE

Colchicine has been used to treat gout and, more recently, to effectively prevent autoinflammatory diseases and both primary and recurrent episodes of pericarditis. The anti-inflammatory action of colchicine seems to result from irreversible inhibition of tubulin polymerization and microtubule (MT) assembly by binding to the tubulin heterodimer, avoiding the signal transduction required to the activation of the entire NLRP3 inflammasome. Emerging results show that the MT network is a potential regulator of cardiac mechanics. Here, we investigated how colchicine impacts in tubulin folding cofactors TBCA, TBCB, and TBCE activities. We show that TBCA is abundant in mouse heart insoluble protein extracts. Also, a decrease of the TBCA/β-tubulin complex followed by an increase of free TBCA is observed in human cells treated with colchicine. The presence of free TBCA is not observed in cells treated with other anti-mitotic agents such as nocodazole or cold shock, neither after translation inhibition by cycloheximide. In vitro assays show that colchicine inhibits tubulin heterodimer dissociation by TBCE/TBCB, probably by interfering with interactions of TBCE with tubulin dimers, leading to free TBCA. Manipulation of TBCA levels, either by RNAi or overexpression results in decreased levels of tubulin heterodimers. Together, these data strongly suggest that TBCA is mainly receiving β-tubulin from the dissociation of pre-existing heterodimers instead of newly synthesized tubulins. The TBCE/TBCB+TBCA system is crucial for controlling the critical concentration of free tubulin heterodimers and MT dynamics in the cells by recycling the tubulin heterodimers. It is conceivable that colchicine affects tubulin heterodimer recycling through the TBCE/TBCB+TBCA system producing the known benefits in the treatment of pericardium inflammation.

Spatio-temporal distribution of tubulin-binding cofactors and posttranslational modifications of tubulin in the cochlea of mice

The five tubulin-binding cofactors (TBC) are involved in tubulin synthesis and the formation of microtubules. Their importance is highlighted by various diseases and syndromes caused by dysfunction or mutation of these proteins. Posttranslational modifications (PTMs) of tubulin promote different characteristics, including stability-creating subpopulations of tubulin. Cell- and time-specific distribution of PTMs has only been investigated in the organ of Corti in gerbils. The aim of the presented study was to investigate the cell type-specific and time-specific expression patterns of TBC proteins and PTMs for the first time in murine cochleae over several developmental stages. For this, murine cochleae were investigated at the postnatal (P) age P1, P7 and P14 by immunofluorescence analysis. The investigations revealed several profound interspecies differences in the distribution of PTMs between gerbil and mouse. Furthermore, this is the first study to describe the spatio-temporal distribution of TBCs in any tissue ever showing a volatile pattern of expression. The expression analysis of TBC proteins and PTMs of tubulin reveals that these proteins play a role in the physiological development of the cochlea and might be essential for hearing.

miR-363 suppresses the proliferation, migration and invasion of clear cell renal cell carcinoma by downregulating S1PR1

Background

MicroRNAs (miRNAs) serve as important regulators of the tumorigenesis and progression of many human cancers. Therefore, we evaluated the biological function and underlying mechanism of miR-363 in clear cell renal cell carcinoma (ccRCC).

Methods

The expression of miR-363 in ccRCC tissues compared with adjacent normal renal tissues was detected by quantitative real-time polymerase chain reaction, and the association between miR-363 levels and prognosis of ccRCC patients was analyzed. The candidate target gene of miR-363 was determined by in silico analysis and luciferase reporter assays. The effects of miR-363 on the proliferation, migration and invasion of ccRCC cells in vitro were determined by MTS assay, colony formation assay, Transwell assay and wound healing assay. We also investigated the roles of miR-363 in vivo by a xenograft tumour model. The mechanism of miR-363 on the proliferation, migration and invasion of ccRCC was determined by gain- and loss-of-function analyses.

Results

we demonstrated that miR-363 expression was obviously downregulated in ccRCC tissues and that reduced miR-363 expression was correlated with poor disease-free survival (DFS) in ccRCC patients after surgery. S1PR1 expression was inversely correlated with the level of miR-363 in human ccRCC samples. Luciferase reporter assays suggested that S1PR1 was a direct functional target of miR-363. miR-363 downregulated S1PR1 expression and suppressed the proliferation, migration and invasion abilities of ccRCC cells in vitro and suppressed xenograft tumour growth in vivo. Importantly, miR-363 exerted its biological function by inhibiting S1PR1 expression in ccRCC cells, leading to the repression of ERK activation. Moreover, we found that the levels of downstream effectors of ERK, including PDGF-A, PDGF-B, and epithelial-mesenchymal transition (EMT)-related genes, were decreased after miR-363 overexpression.

Conclusions

Our results suggest that miR-363 acts as a tumour suppressor by directly targeting S1PR1 in ccRCC and may be a potential new therapeutic target for ccRCC.

ZNF139/circZNF139 promotes cell proliferation, migration and invasion via activation of PI3K/AKT pathway in bladder cancer

Existing reports identify the involved roles of ZNF139 and its one circular RNA (circRNA), circZNF139, in the progression of various tumors. However, their relevance and function role in bladder cancer (BC) remain largely unexplored. Herein, we aimed to reconnoiter the role and potential mechanism of ZNF139 and circZNF139 in the progression of BC. Firstly, bioinformatics analyses indicated ZNF139 was upregulated in BC tissues and correlated with disease-free survival of BC patients. The subcellular localization and structural analyses of ZNF139 conveyed the possibility of ZNF139 functioning as a transcription factor. Secondly, circZNF139 was validated by bioinformatics analyses and RNase R tests. ZNF139 and circZNF139 were both significantly upregulated in BC cell lines. Functionally, ZNF139/circZNF139 had facilitated effects on the proliferative, clonal, migratory, and invasive potential of BC cells. Mechanistically, GO, KEGG pathway analyses and western blot assays altogether unveiled ZNF139/circZNF139 activated PI3K/AKT pathway in BC cells, supported by the alteration of AKT at phosphorylation level and PI3K at the protein level. Collectively, this work reveals ZNF139 and circZNF139 cooperate closely with each other to promote cell proliferation, migration and invasion via activation of PI3K/AKT pathway in BC.

The TGF-β/Smad Pathway Inhibitor SB431542 Enhances The Antitumor Effect Of Radiofrequency Ablation On Bladder Cancer Cells

Background

Despite progress achieved in bladder cancer (BC) treatment, the prognosis of patients with advanced BC (ie, metastasized from the bladder to other organs) is poor. Although mortality in cases of low-grade BC is rare, the treatment, such as a radical cystectomy, often has a serious impact on the quality of life. Thus, research is needed to identify more effective treatment strategies and this work is aiming to examine the potential application of combination of radiofrequency ablation (RFA) and SB435142, a inhibitor of transforming growth factor β (TGFβ)/Smad pathway.

Methods

BC cells were transplanted into nude mice (thymusdeficiency Bal B/c) to form subcutaneous tumors. The mice with subcutaneous tumors were then treated with RFA and oral administration of SB431542, an inhibitor of TGFβ/Smad signaling pathway. The antitumor effect of RFA was measured by tumor proliferation curves and micro-positron emission computed tomography (micro-PET). The effect of SB431542 on epithelial-mesenchymal transition (EMT) related regulators in subcutaneous tumor tissues formed by BC cells were examined by quantitative real-time polymerase chain reaction (qPCR) experiments.

Results

The SB431542 treatment enhanced the antitumor effect of RFA on subcutaneous growth of BCs. SB431542 also decreased EMT-related regulators in subcutaneous tumor tissues formed by BC cells in nude mice.

Conclusion

SB431542 enhances the effect of RFA on BC.

LncRNA ADAMTS9-AS2 inhibits cell proliferation and decreases chemoresistance in clear cell renal cell carcinoma via the miR-27a-3p/FOXO1 axis

Accumulating evidence reveals the principal role of long noncoding RNAs in the progression of clear cell renal cell carcinoma (ccRCC). However, little is known about the underlying mechanism of ADAM metallopeptidase with thrombospondin type 1 motif, 9 antisense RNA 2 (ADAMTS9-AS2) in ccRCC. Here, bioinformatics analyses verified ADAMTS9-AS2 is a long noncoding RNA and its high expression was associated with better prognosis of ccRCC. ADAMTS9-AS2 was clearly downregulated in ccRCC clinical samples and cell lines. Clinical data showed low-expressed ADAMTS9-AS2 was correlated with worse overall survival in ccRCC patients. Next, miR-27a-3p was identified as an inhibitory target of ADAMTS9-AS2 by dual-luciferase reporter and RNA immunoprecipitation assays. Both overexpressed ADAMTS9-AS2 and underexpressed miR-27a-3p in ccRCC cell lines led to the inhibition of cell proliferation and the reduction of chemoresistance. Additionally, Forkhead Box Protein O1 (FOXO1) was confirmed as the inhibitory target of miR-27a-3p. Induced by ADAMTS9-AS2 overexpression, cell proliferation and chemoresistance exhibited an obvious reduction, FOXO1 expression showed an evident increase, but all were reversed after miR-27a-3p was simultaneously overexpressed. Collectively, these results suggest ADAMTS9-AS2 inhibits the progression and impairs the chemoresistance of ccRCC via miR-27a-3p-mediated regulation of FOXO1 and may serve as a prognostic biomarker and therapeutic target for ccRCC.

MicroRNA-1251-5p Promotes Carcinogenesis and Autophagy via Targeting the Tumor Suppressor TBCC in Ovarian Cancer Cells

Accounting for more than 70% of ovarian cancer cases, epithelial ovarian malignancy has a low 5-year survival rate. MicroRNAs may be targeted in the clinical treatment of the disease. In this study, we first found that miR-1251-5p was significantly upregulated in human ovarian cancer cell lines and tissues with the cancer progression and stages. Overexpression or inhibition of miR-1251-5p promoted or impeded cell proliferation and cell cycle progression. Subsequently, TBCC, one of the tubulin-binding cofactors (TBCs), was identified as a target of miR-1251-5p to be negatively associated with cell cycle and autophagy. Exogenous overexpression of TBCC inhibited the expressions of CDK4 and LC3BII, but it promoted the expressions of α/β-tubulin and p62 to suppress cell growth and autophagy, particularly under the starving condition; whereas the introduction of miR-1251-5p in TBCC-overexpressing cells rescued the suppressive effects of TBCC on cell cycle and autophagy through the inverse regulation of the above proteins. Finally, miR-1251-5p was proven to enhance xenograft tumor growth through the downregulation of TBCC but upregulation of Ki67 and LC3B in xenograft tumor tissues. Collectively, these results suggest that miR-1251-5p functions as an oncogene to suppress TBCC and α/β-tubulin expression. Thus, the miR-1251-5p/TBCC/α/β-tubulin axis may be targeted for ovarian cancer treatment.

Effect of the hyaluronic acid-poloxamer hydrogel on skin-wound healing: in vitro and in vivo studies

BACKGROUND

Recent research into skin injury and wound healing has focused mainly on post-trauma hemostasis, infection prevention, dermal regeneration and angiogenesis. However, less attention has been paid to air permeability and moisture loss prevention which also play important roles in injury healing.

METHODS

In the present work, we prepared a hyaluronic acid-poloxamer (HA-POL) hydrogel and tested the therapeutic effect of the hydrogel on skin-wound healing.

RESULTS

The HA-POL hydrogel transformed from sol to gel at 30°C, close to body temperature, and had stable moisturizing properties. HA-POL hydrogel promoted skin-wound healing and increased protein accumulation in the wound area. HA-POL hydrogel allowed greater air permeability than Band-aid, a typical wound covering. Results from transwell assays showed that the HA-POL hydrogel effectively isolated skin-wounds from bacterial invasion.

CONCLUSION

This work demonstrates the advantages of using HA-POL gel materials in the treatment of cutaneous wounds.

The uremic toxin p-cresyl sulfate induces proliferation and migration of clear cell renal cell carcinoma via microRNA-21/ HIF-1α axis signals

p-Cresyl sulfate (pCS), a uremic toxin, can cause renal damage and dysfunction. Studies suggest that renal dysfunction increases the prevalence of renal cancer. However, the effect of pCS on the proliferation and migration of renal cancer is unclear. Clear cell renal cell carcinoma (ccRCC) expresses mutant von Hippel-Lindau gene and is difficult to treat. Hypoxia-inducible factor-1α and 2-α (HIF-1α and HIF-2α) as well as microRNA-21 (miR-21) can regulate the proliferation and migration of ccRCC cells. However, the association between HIF-α and miR-21 in ccRCC remains unclear. Therefore, the effects of pCS on ccRCC cells were investigated for HIF-α and miR-21 signals. Our results showed that pCS induced overexpression of HIF-1α and promoted the proliferation and regulated epithelial-mesenchymal transition-related proteins, including E-cadherin, fibronectin, twist and vimentin in ccRCC cells. pCS treatment increased miR-21 expression. Specifically, inhibition of miR-21 blocked pCS-induced proliferation and migration. Taken together, the present results demonstrate that pCS directly induced the proliferation and migration of ccRCC cells through mechanisms involving miR-21/HIF-1α signaling pathways.

Study on the mechanism behind lncRNA MEG3 affecting clear cell renal cell carcinoma by regulating miR-7/RASL11B signaling

The goal of this research was to study the relationships between maternally expressed gene 3 (MEG3), microRNA-7 (miR-7), and RASL11B, and explore their influence on the progression of clear cell renal cell carcinoma (CCRCC). Microarray analysis was conducted using the data provided by The Cancer Genome Atlas. The expression levels of MEG3 and miR-7 in CCRCC and adjacent tissue samples were ascertained by quantitative real-time polymerase chain reaction (qRT-PCR). The cell proliferation activity was unmasked by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell apoptosis and cell cycle were investigated by flow cytometry. A dual luciferase reporter assay was used to verify target relationships. Wound healing assay and transwell assay were used to detect cell migration and invasion ability. Decreased MEG3 expression was observed in CCRCC tissues and cells. Overexpression of MEG3 accelerated apoptosis; inhibited cell proliferation, migration and invasion; and induced G0/G1 phase cell cycle arrest in CCRCC. MiR-7, directly binding to MEG3, was overexpressed in the CCRCC tissues and could inhibit the apoptosis and promote the migration and invasion of CCRCC cells. RASL11B, lowly expressed in CCRCC, was a target of miR-7. After the overexpression of RASL11B, G0/G1 phase cell cycle arrest was induced; cell apoptosis was promoted; and the proliferation, invasion, and migration of CCRCC cells were inhibited. MEG3 could up-regulate RASL11B to inhibit the cell proliferation, invasion, and migration; induce G0/G1 cell cycle arrest; and promote cell apoptosis by suppressing miR-7 in CCRCC.

Increased expression of αTubulin is associated with poor prognosis in patients with pancreatic cancer after surgical resection

Background

αTubulin, the essential orchestrator of cytoskeletal protein polymers, critical for cell growth and division, motility, signaling development and maintenance of cell shape, plays vital roles in the oncogenesis and progression of various types of cancer, but its role in prognosis of pancreatic cancer patients remains unknown. The aim of this study was to investigate its prognostic value in patients with pancreatic cancer after surgical resection.

Results

αTubulin expression in pancreatic cancer was significantly associated with N classification (p = 0.013) and TNM stage (p = 0.025). Increased expression of αTubulin in tumoral tissue was associated with decreased overall survival rate (p = 0.002). Multivariate Cox regression analysis suggested that αTubulin expression was an independent prognostic indicator for pancreatic cancer except for T and N classification (p = 0.002). Using multivariate analysis, αTubulin expression, CA19-9, and N classification were selected to generate the nomogram to predict the 1-year and 3-year overall survival. The c-index of this model was 0.692. The calibration curve for probability of survival showed good agreement between prediction by nomogram and actual observation.

Methods

αTubulin expression was evaluated by tissue microarrays from 124 pancreatic cancer patients and statistically assessed for correlations with the clinical profiles and the prognosis of the patients with pancreatic cancer. The prognostic nomogram was designed to predict 1-year and 3-year overall survival probability.

Conclusions

αTubulin expression might be an independent prognostic factor for pancreatic cancer after surgical resection and could potentially be a high-priority therapeutic target. Incorporating αTubulin expression into CA19-9 and N classification can provide a good prognostic model.

Overexpression of CAPN2 promotes cell metastasis and proliferation via AKT/mTOR signaling in renal cell carcinoma

The calpain 2 (CAPN2) is upregulated in various malignant carcinomas. Previous studies have reported that CAPN2 functioned as an oncogenic factor in human cancers. However, its clinical role and potential effects on cell metastasis and proliferation in renal cell carcinoma (RCC) remain unknown. In this study, we evaluated the mRNA and protein levels of CAPN2 in human RCC specimens, matched normal specimens, and RCC cell lines using quantitative Real-time PCR (RT-PCR) and western blot. Immunohistochemistry of 74 RCC tissues in a tissue microarrays (TMAs) and normal kidney tissues were performed. Kaplan-Meier survival curve analyses were conducted to measure the correlation between CAPN2 and tumor prognosis. Cell migration, invasion and proliferation were detected by transwell assays and Cell Counting Kit-8 (CCK-8) assays. CAPN2 exhibited a significant overexpression in human RCC tissues and cell lines compared with adjacent non-tumor tissues and normal human proximal tubule epithelial cell line HK-2. Strong staining of CAPN2 was associated with higher clinical stage and histological grade. In addition, sh-CAPN2 could significantly inhibit migration, invasion and proliferation of 769-P and CAKI-1 cells. Conversely, increased cell biological behaviors were observed in CAPN2-OV CAKI-2 cells. Moreover, the subsequent mechanism investigation suggested that CAPN2 promoted tumor progression by activating AKT/mTOR signaling, enhancing epithelial mesenchymal transition (EMT) and MMP9 levels. The present study indicates that CAPN2 may act as a prominent indicator for RCC progression and a novel therapeutic target for RCC patients.

RNA interference-mediated knockdown of SIRT1 and/or SIRT2 in melanoma: Identification of downstream targets by large-scale proteomics analysis

Melanoma is the most notorious and fatal of all skin cancers and the existing treatment options have not been proven to effectively manage this neoplasm, especially the metastatic disease. Sirtuin (SIRT) proteins have been shown to be differentially expressed in melanoma. We have shown that SIRTs 1 and 2 were overexpressed in melanoma and inhibition of SIRT1 imparts anti-proliferative responses in human melanoma cells. To elucidate the impact of SIRT 1 and/or 2 in melanoma, we created stable knockdowns of SIRTs 1, 2, and their combination using shRNA mediated RNA interference in A375 human melanoma cells. We found that SIRT1 and SIRT1&2 combination knockdown caused a decreased cellular proliferation in melanoma cells. Further, the knockdown of SIRT 1 and/or 2 resulted in a decreased colony formation in melanoma cells. To explore the downstream targets of SIRTs 1 and/or 2, we employed a label-free quantitative nano-LC-MS/MS proteomics analysis using the stable lines. We found aberrant levels of proteins involved in many vital cellular processes, including cytoskeletal organization, ribosomal activity, oxidative stress response, and angiogenesis. These findings provide clear evidence of cellular systems undergoing alterations in response to sirtuin inhibition, and have unveiled several excellent candidates for future study.

SIGNIFICANCE

Melanoma is the deadliest form of skin cancer, due to its aggressive nature, metastatic potential, and a lack of sufficient treatment options for advanced disease. Therefore, detailed investigations into the molecular mechanisms of melanoma growth and progression are needed. In the search for candidate genes to serve as therapeutic targets, the sirtuins show promise as they have been found to be upregulated in melanoma and they regulate a large number of proteins involved in cellular processes known to affect tumor growth, such as DNA damage repair, cell cycle arrest, and apoptosis. In this study, we used a large-scale label-free comparative proteomics system to identify novel protein targets that are affected following knockdown of SIRT1 and/or 2 in A375 metastatic melanoma cell line. Our study offers important insight into the potential downstream targets of SIRTs 1 and/or 2. This may unravel new potential areas of exploration in melanoma research.

MEIS1 inhibits clear cell renal cell carcinoma cells proliferation and in vitro invasion or migration

BACKGROUND

Myeloid ecotropic viral integration site 1 (MEIS1) protein plays a synergistic causative role in acute myeloid leukemia (AML). However, MEIS1 has also shown to be a potential tumor suppressor in some other cancers, such as non-small-cell lung cancer (NSCLC) and prostate cancer. Although multiple roles of MEIS1 in cancer development and progression have been identified, there is an urgent demand to discover more functions of this molecule for further therapeutic design.

METHODS

MEIS1 was overexpressed via adenovirus vector in clear cell renal cell carcinoma (ccRCC) cells. Western blot and real-time qPCR (quantitative Polymerase Chain Reaction) was performed to examine the protein and mRNA levels of MEIS1. Cell proliferation, survival, in vitro migration and invasion were tested by MTT, colony formation, soft-agar, transwell (in vitro invasion/migration) assays, and tumor in vivo growthwas measured on nude mice model. In addition, flow-cytometry analysis was used to detect cell cycle arrest or non-apoptotic cell death of ccRCC cells induced by MEIS1.

RESULTS

MEIS1 exhibits a decreased expression in ccRCC cell lines than that in non-tumor cell lines. MEIS1 overexpression inhibits ccRCC cells proliferation and induces G1/S arrest concomitant with marked reduction of G1/S transition regulators, Cyclin D1 and Cyclin A. Moreover, MEIS1-1 overexpression also induces non-apoptotic cell death of ccRCC cells via decreasing the levels of pro-survival regulators Survivin and BCL-2. Transwell migration assay (TMA) shows that MEIS1 attenuates in vitro invasion and migration of ccRCC cells with down-regulated epithelial-mesenchymal transition (EMT) process. Further, in nude mice model, MEIS1 inhibits the in vivo growth of Caki-1 cells.

CONCLUSIONS

By investigating the role of MEIS1 in ccRCC cells' survival, proliferation, anchorage-independent growth, cell cycle progress, apoptosis and metastasis, in the present work, we propose that MEIS1 may play an important role in clear cell renal cell carcinoma (ccRCC) development.

Expression of microRNA-30c via lentivirus vector inhibits the proliferation and enhances the sensitivity of highly aggressive ccRCC Caki-1 cells to anticancer agents

The clear cell renal cell carcinoma (ccRCC) is one of the most fatal urologic tumors, and the prognosis remains very poor for advanced or metastatic ccRCC. This study reveals the roles of microRNA (miR)-30c in regulating a highly aggressive ccRCC cell line proliferation by targeting MTA-1, which is a key mediator for human cancer metastasis. Results from quantitative real-time polymerase chain reaction showed that the expression of MTA-1, the target of miR-30c, was significantly higher in metastatic ccRCC specimens than in nonmetastatic ccRCC or nontumor specimens. Accordingly, endogenous miR-30c is at a much lower level in highly aggressive ccRCC Caki-1 cells than nontumor or ccRCC cell lines. Expression of miR-30c via lentivirus vector inhibits the proliferation, anchorage-independent growth, in vitro invasion or migration, or in vivo growth of Caki-1 cells by repressing MTA-1 protein expression. miR-30c also enhances the sensitivity of Caki-1 cells to anticancer agents, including sorafenib and paclitaxel. These data reveal the potential application of miR-30c and that its targeting gene, MTA-1, would be a potential target in metastatic ccRCC treatment.

Expression of microRNA-452 via adenoviral vector inhibits non-small cell lung cancer cells proliferation and metastasis

The microRNA miR-452 has been shown to function as a tumor suppressor. However, the cellular mechanism and potential application of miR-452-mediated cancer suppression remain great unknown. This study aims to identify how miR-452 acts in regulating non-small cell lung cancer (NSCLC) proliferation and metastasis. Expression of miR-452 via adenoviral (Ad) vector inhibits the proliferation, invasion, and migration of NSCLC cells A549 or H460. Our data also shows that miR-452 down-regulates the expression of Bmi-1 as well as pro-survival or anti-apoptosis regulators Survivin, cIAP-1, and cIAP-2. By such gene interference, miR-452 modulates NSCLC cell epithelial-mesenchymal transition (EMT) and further disrupts their migration and invasion. Moreover, miR-452 blocks the activation of PI3K/AKT pathway, which is also required for EMT process. These data reveal that miR-452 treatment could be a novel target or strategy for NSCLC treatment.

MiR-122 Induces Radiosensitization in Non-Small Cell Lung Cancer Cell Line

MiR-122 is a novel tumor suppresser and its expression induces cell cycle arrest, or apoptosis, and inhibits cell proliferation in multiple cancer cells, including non-small cell lung cancer (NSCLC) cells. Radioresistance of cancer cell leads to the major drawback of radiotherapy for NSCLC and the induction of radiosensitization could be a useful strategy to fix this problem. The present work investigates the function of miR-122 in inducing radiosensitization in A549 cell, a type of NSCLC cells. MiR-122 induces the radiosensitization of A549 cells. MiR-122 also boosts the inhibitory activity of ionizing radiation (IR) on cancer cell anchor-independent growth and invasion. Moreover, miR-122 reduced the expression of its targeted genes related to tumor-survival or cellular stress response. These results indicate that miR-122 would be a novel strategy for NSCLC radiation-therapy.

Estrogen receptor α enhances the transcriptional activity of ETS-1 and promotes the proliferation, migration and invasion of neuroblastoma cell in a ligand dependent manner

BACKGROUND

It is well known that estrogen receptor α (ERα) participates in the pathogenic progress of breast cancer, hepatocellular carcinoma and head and neck squamous cell carcinoma. In neuroblastoma cells and related cancer clinical specimens, moreover, the ectopic expression of ERα has been identified. However, the detailed function of ERα in the proliferation of neuroblastoma cell is yet unclear.

METHODS

The transcriptional activity of ETS-1 (E26 transformation specific sequence 1) was measured by luciferase analysis. Western blot assays and Real-time RT-PCR were used to examine the expression of ERα, ETS-1 and its targeted genes. The protein-protein interaction between ERα and ETS-1 was determined by co-IP and GST-Pull down assays. The accumulation of ETS-1 in nuclear was detected by western blot assays, and the recruitment of ETS-1 to its targeted gene's promoter was tested by ChIP assays. Moreover, SH-SY5Y cells' proliferation, anchor-independent growth, migration and invasion were quantified using the MTT, soft agar or Trans-well assay, respectively.

RESULTS

The transcriptional activity of ETS-1 was significantly increased following estrogen treatment, and this effect was related to ligand-mediated activation of ERα. The interaction between the ERα and ETS-1 was identified, and enhancement of ERα activation would up-regulate the ETS-1 transcription factor activity via modulating its cytoplasm/nucleus translocation and the recruitment of ETS-1 to its target gene's promoter. Furthermore, treatment of estrogen increased proliferation, migration and invasion of neuroblastoma cells, whereas the antagonist of ERα reduced those effects.

CONCLUSIONS

In this study, we provided evidences that activation of ERα promoted neuroblastoma cells proliferation and up-regulated the transcriptional activity of ETS-1. By investigating the role of ERα in the ETS-1 activity regulation, we demonstrated that ERα may be a novel ETS-1 co-activator and thus a potential therapeutic target in human neuroblastoma treatment.

The tubulin cofactor A is involved in hyphal growth, conidiation and cold sensitivity in Fusarium asiaticum

BACKGROUND

Tubulin cofactor A (TBCA), one of the members of tubulin cofactors, is of great importance in microtubule functions through participating in the folding of α/β-tubulin heterodimers in Saccharomyces cerevisiae. However, little is known about the roles of TBCA in filamentous fungi.

RESULTS

In this study, we characterized a TBCA orthologue FaTBCA in Fusarium asiaticum. The deletion of FaTBCA caused dramatically reduced mycelial growth and abnormal conidiation. The FaTBCA deletion mutant (ΔFaTBCA-3) showed increased sensitivity to low temperatures and even lost the ability of growth at 4°C. Microscopic observation found that hyphae of ΔFaTBCA-3 exhibited blebbing phenotypes after shifting from 25 to 4°C for 1- or 3-day incubation and approximately 72% enlarged nodes contained several nuclei after 3-day incubation at 4°C. However, hyphae of the wild type incubated at 4°C were phenotypically indistinguishable from those incubated at 25°C. These results indicate that FaTBCA is involved in cell division under cold stress (4°C) in F. asiaticum. Unexpectedly, ΔFaTBCA-3 did not exhibit increased sensitivity to the anti-microtubule drug carbendazim although quantitative real-time assays showed that the expression of FaTBCA was up-regulated after treatment with carbendazim. In addition, pathogenicity assays showed that ΔFaTBCA-3 exhibited decreased virulence on wheat head and on non-host tomato.

CONCLUSION

Taken together, results of this study indicate that FaTBCA plays crucial roles in vegetative growth, conidiation, temperature sensitivity and virulence in F. asiaticum.

Hypoxia-induced overexpression of stanniocalcin-1 is associated with the metastasis of early stage clear cell renal cell carcinoma

Background

Although metastasis of clear cell renal cell carcinoma (ccRCC) is predominantly observed in late stage tumors, early stage metastasis of ccRCC can also be found with indefinite molecular mechanism, leading to inappropriate clinical decisions and poor prognosis. Stanniocalcin-1 (STC1) is a glycoprotein hormone involved in calcium/phosphate homeostasis, which regulates various cellular processes in normal development and tumorigenesis. This study aimed to investigate the role and mechanism of regulation of STC1 in the metastasis of early stage ccRCC.

Methods

STC1 mRNA and protein expression was determined in ccRCC surgical specimens, RCC cell lines, and human kidney tubule epithelial cell line HKC by real-time polymerase chain reaction (RT-PCR) and western blotting. Immunohistochemistry staining (IHC) and immunofluorescence were also used to examine the expression and localization of STC1 in ccRCC tissues and cancer cells. Knockdown and overexpression studies were conducted in vitro in RCC cell lines using small interfering RNAs (siRNA) and lentiviral-mediated gene delivery to evaluate the role of STC1 in cell proliferation, anchorage-dependent and independent growth, cell cycle control, and migration and invasion.

Results

STC1 mRNA and protein expression were significantly up-regulated in tumors when compared with non-tumor tissues, with the greatest increase in expression observed in metastatic tissues. Clinicopathological analysis revealed that STC1 mRNA expression was associated with Fuhrman tumor grade (P = 0.008) and overall Tumor Node Metastasis (TNM) staging (P = 0.018). STC1 expression was elevated in T1 stage metastatic tumors when compared with localized tumors, and was positively correlated with average tumor diameter. Silencing of STC1 expression by Caki-1 and A498 resulted in the inhibition of cell proliferation, migration, and invasion, meanwhile down-regulation of STC1 impaired epithelial–mesenchymal transition (EMT) of ccRCC cell lines. Overexpression of STC1 in Caki-2 enhanced cell growth and proliferation but not migration and invasion. Further investigation identified hypoxia and HIF-1α as candidate regulators of STC1 expression.

Conclusions

Our findings demonstrate a role for STC1 in metastasis of early stage ccRCC and suggest that STC1 may be a biomarker of potential value both for the prognosis of this disease and for guiding clinical decisions regarding surgical strategies and adjuvant treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0421-4) contains supplementary material, which is available to authorized users.

βIII-tubulin overexpression is linked to aggressive tumor features and shortened survival in clear cell renal cell carcinoma

AIMS

βIII-tubulin (TUBB3) is a microtubule component overexpression of which is found in many solid cancer types, often linked to poor patient prognosis, and has been suggested to predict failure of microtubule-targeting chemotherapeutics. This study was designed to determine prevalence and prognostic impact of TUBB3 expression in kidney cancers.

METHODS AND RESULTS

A tissue microarray (TMA) containing more than 1,200 renal tumors was analyzed by immunohistochemistry. TUBB3 expression varied markedly between the different histological subtypes and was more frequent in 105 papillary cancers (75.2 %, p < 0.0001), 38 oncocytomas (52.6 %, p < 0.0001), and 22 chromophobic carcinomas (36.4 %, p = 0.1221) than in 555 clear cell RCC (16.4 %). In clear cell cancers, strong TUBB3 positivity was linked to high Fuhrman grade (p < 0.0001), advanced stage (0.002), nodal metastases (p = 0.0433), hematogenous metastases (p = 0.0016), and shortened overall survival (p < 0.0001). Associations with outcome and tumor phenotype were inversely for papillary RCC, where TUBB3 immunostaining was linked to low tumor stage (p = 0.0012) and prolonged survival (p = 0.0043).

CONCLUSIONS

TUBB3 expression levels and their effects are strikingly different between ccRCC and papillary RCC. These differences may be caused by differences in VHL function between these RCC subtypes, because VHL (like TUBB3) is another strong regulator of microtubule function.

EPAS-1 mediates SP-1-dependent FBI-1 expression and regulates tumor cell survival and proliferation

Factor binding IST-1 (FBI-1) plays an important role in oncogenic transformation and tumorigenesis. As FBI-1 is over-expressed in multiple human cancers, the regulation of itself would provide new effective options for cancer intervention. In this work, we aimed to study the role that EPAS-1 plays in regulating FBI-1. We use the fact that specificity protein-1 (SP-1) is one of the crucial transcription factors of FBI-1, and that SP-1 can interact with the endothelial pas domain protein-1 (EPAS-1) for the induction of hypoxia related genes. The study showed that EPAS-1 plays an indispensible role in SP-1 transcription factor-mediated FBI-1 induction, and participated in tumor cell survival and proliferation. Thus, EPAS-1 could be a novel target for cancer therapeutics.