SOX4 transcriptionally regulates multiple SEMA3/plexin family members and promotes tumor growth in pancreatic cancer

Retracted article: MYCN contributes to the sensitization of acute myelogenous leukemia cells to cisplatin by targeting SRY-box transcription factor 4

Xianbao Huang, Ling Qi, Wei Lu, Ziye Li, Wuping Li and Fei Li. MYCN contributes to the sensitization of acute myelogenous leukemia cells to cisplatin by targeting SRY-box transcription factor 4. Bioengineered. 2021 Oct. doi: 10.1080/21655979.2021.1997697.Since publication, significant concerns have been raised about the compliance with ethical policies for human research and the integrity of the data reported in the article.When approached for an explanation, the authors provided some original data but were not able to provide all the necessary supporting information. As verifying the validity of published work is core to the scholarly record's integrity, we are retracting the article. All authors listed in this publication have been informed.We have been informed in our decision-making by our editorial policies and the COPE guidelines.The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as 'Retracted.'

CircRNAs in Pancreatic Cancer: New Tools for Target Identification and Therapeutic Intervention

We have reviewed the literature for circular RNAs (circRNAs) with efficacy in preclinical pancreatic-cancer related in vivo models. The identified circRNAs target chemoresistance mechanisms (n=5), secreted proteins and transmembrane receptors (n=15), transcription factors (n=9), components of the signaling- (n=11), ubiquitination- (n=2), autophagy-system (n=2), and others (n=9). In addition to identifying targets for therapeutic intervention, circRNAs are potential new entities for treatment of pancreatic cancer. Up-regulated circRNAs can be inhibited by antisense oligonucleotides (ASO), small interfering RNAs (siRNAs), short hairpin RNAs (shRNAs) or clustered regularly interspaced short-palindromic repeats-CRISPR associated protein (CRISPR-CAS)-based intervention. The function of down-regulated circRNAs can be reconstituted by replacement therapy using plasmids or virus-based vector systems. Target validation experiments and the development of improved delivery systems for corresponding agents were examined.

LncRNA SNHG14 silencing attenuates the progression of diabetic nephropathy via the miR-30e-5p/SOX4 axis

BACKGROUND

Diabetic nephropathy (DN) is a diabetic complication. LncRNAs are reported to participate in the pathophysiology of DN. Here, the function and mechanism of lncRNA small nucleolar RNA host gene 14 (SNHG14) in DN were explored.

METHODS

Streptozotocin (STZ)-induced DN mouse models and high glucose (HG)-treated human mesangial cells (MCs) were used to detect SNHG14 expression. SNHG14 silencing plasmids were applied to examine the function of SNHG14 on proliferation and fibrosis in HG-treated MCs. Potential targets of SNHG14 were predicted using bioinformatics tools and verified by luciferase reporter, RNA pulldown, and northern blotting assays. The functional role of SNHG14 in DN in vivo was detected by injection with adenoviral vector carrying sh-SNHG14 into DN mice. Serum creatinine, blood urea nitrogen, blood glucose, 24-h proteinuria, relative kidney weight, and renal pathological changes were examined in DN mice.

RESULTS

SNHG14 expression was elevated in the kidneys of DN mice and HG-treated MCs. SNHG14 silencing inhibited proliferation and fibrosis of HG-stimulated MCs. SNHG14 bound to miR-30e-5p to upregulate SOX4 expression. In rescue assays, SOX4 elevation diminished the effects of SNHG14 silencing in HG-treated MCs, and SOX4 silencing reversed the effects of SNHG14 overexpression. In in vivo studies, SNHG14 downregulation significantly ameliorated renal injuries and renal interstitial fibrosis in DN mice.

CONCLUSIONS

SNHG14 silencing attenuates kidney injury in DN mice and reduces proliferation and fibrotic phenotype of HG-stimulated MCs via the miR-30e-5p/SOX4 axis.

Promising Therapeutic Targets in Kidney Renal Clear Cell Carcinoma: PLXNA1 and PLXNB3

Aims: This study sets out to identify dysregulated plexins and investigate their roles in KIRC through an integrated bioinformatics approach. Methods: RNA-sequencing data and clinicopathological information of KIRC, extracted from The Cancer Genome Atlas (TCGA) database, were used to perform comprehensive bioinformatics analysis. Results: Almost all plexin gene family members were dysregulated in KIRC. Univariate and multivariate Cox regression analyses revealed that PLXNA1/B3 were independent prognostic factors of overall survival in patients with KIRC. Mechanically, PLXNA1/B3 may promote ccRCC progression through several cancer-related signaling pathways, tumor immunity, and angiogenesis. Drug sensitivity analysis suggested that vemurafenib was the potential drug for PLXNA1/B3. Conclusion: Herein, we found that PLXNA1/B3 were independent prognostic factors, making them attractive new targets for KIRC treatment.

Mind the (guidance) signals! Translational relevance of semaphorins, plexins, and neuropilins in pancreatic cancer

Pancreatic cancer is a major cause of demise worldwide. Although key associated genetic changes have been discovered, disease progression is sustained by pathogenic mechanisms that are poorly understood at the molecular level. In particular, the tissue microenvironment of pancreatic adenocarcinoma (PDAC) is usually characterized by high stromal content, scarce recruitment of immune cells, and the presence of neuronal fibers. Semaphorins and their receptors, plexins and neuropilins, comprise a wide family of regulatory signals that control neurons, endothelial and immune cells, embryo development, and normal tissue homeostasis, as well as the microenvironment of human tumors. We focus on the role of these molecular signals in pancreatic cancer progression, as revealed by experimental research and clinical studies, including novel approaches for cancer treatment.

MicroRNAs in cancer metastasis: biological and therapeutic implications

Cancer metastasis is the primary cause of cancer-related deaths. The seeding of primary tumours at a secondary site is a highly inefficient process requiring substantial alterations in the genetic architecture of cancer cells. These alterations include significant changes in global gene expression patterns. MicroRNAs are small, non-protein coding RNAs which play a central role in regulating gene expression. Here, we focus on microRNA determinants of cancer metastasis and examine microRNA dysregulation in metastatic cancer cells. We dissect the metastatic process in a step-wise manner and summarise the involvement of microRNAs at each step. We also discuss the advantages and limitations of different microRNA-based strategies that have been used to target metastasis in pre-clinical models. Finally, we highlight current clinical trials that use microRNA-based therapies to target advanced or metastatic tumours.

Transcriptional Profile of Human Pancreatic Acinar Ductal Metaplasia

BACKGROUND AND AIMS

Aberrant acinar to ductal metaplasia (ADM), one of the earliest events involved in exocrine pancreatic cancer development, is typically studied using pancreata from genetically engineered mouse models.

METHODS

We used primary, human pancreatic acinar cells from organ donors to evaluate the transcriptional and pathway profiles during the course of ADM.

RESULTS

Following 6 days of three-dimensional culture on Matrigel, acinar cells underwent morphological and molecular changes indicative of ADM. mRNA from 14 donors' paired cells (day 0, acinar phenotype and day 6, ductal phenotype) was subjected to whole transcriptome sequencing. Acinar cell specific genes were significantly downregulated in the samples from the day 6 cultures while ductal cell-specific genes were upregulated. Several regulons of ADM were identified including transcription factors with reduced activity (PTF1A, RBPJL, and BHLHA15) and those ductal and progenitor transcription factors with increased activity (HNF1B, SOX11, and SOX4). Cells with the ductal phenotype contained higher expression of genes increased in pancreatic cancer while cells with an acinar phenotype had lower expression of cancer-associated genes.

CONCLUSION

Our findings support the relevancy of human in vitro models to study pancreas cancer pathogenesis and exocrine cell plasticity.

Suberoylanilide hydroxamic acid (SAHA) attenuates memory impairment in the offspring of rats exposed to sevoflurane anesthesia

BACKGROUND

SAHA was reported to enhance the expression of miR-129-5p, which was predicted to bind to 3' UTR of CASP-6, a gene playing crucial roles in the pathogenesis of memory impairment. Whether SAHA/miR-129-5p/CASP-6 is involved in the pathogenesis of prenatal exposure to sevoflurane remains to be explored.

METHODS

Morris water maze test was performed to evaluate the functional parameters of learning and memory. Quantitative real-time qPCR was carried out to analyze the expression of miRNAs and CASP-6 mRNA under different conditions.

RESULTS

Sevoflurane exposure of pregnant rats and SAHA treatment of the offspring had no effect on the blood gases, litter size, survival rate and weight. SAHA administration remarkably reversed the learning and memory impairment in prenatal rats caused by sevoflurane exposure. Mechanistically, the abnormal expression of miR-129-5p and CASP-6 in the offspring of pregnant rats exposed to sevoflurane was effectively restored by SAHA treatment. The luciferase activity of CASP-6 vector was effectively inhibited by miR-129-5p in primary neuron cells of rats. Moreover, the expression of CASP-6 mRNA and protein was significantly suppressed by miR-129-5p and SAHA treatment in a dose-dependent manner.

CONCLUSION

Our work demonstrated that the administration of SAHA suppressed the expression of CASP-6 via modulating the expression of miR-129-5p, and SAHA may rescue the apoptosis of neurons caused by exposure to sevoflurane. The underlying mechanism might be the ability of SAHA to relieve learning and memory impairment in the offspring of the pregnant rats exposed to sevoflurane.

ID1 marks the tumorigenesis of pancreatic ductal adenocarcinoma in mouse and human

Pancreatic Ductal Adenocarcinoma (PDAC) is a deadly disease that has an increasing death rate but no effective treatment to now. Although biological and immunological hallmarks of PDAC have been frequently reported recently, early detection and the particularly aggressive biological features are the major challenges remaining unclear. In the current study, we retrieved multiple scRNA-seq datasets and illustrated the genetic programs of PDAC development in genetically modified mouse models. Notably, the transcription levels of Id1 were elevated specifically along with the PDAC development. Pseudotime trajectory analysis revealed that Id1 was closely correlated with the malignancy of PDAC. The gene expression patterns of human PDAC cells were determined by the comparative analysis of the scRNA-seq data on human PDAC and normal pancreas tissues. ID1 levels in human PDAC cancer cells were dramatically increased compared to normal epithelial cells. ID1 deficiency in vitro significantly blunt the invasive tumor-formation related phenotypes. IPA analysis on the differentially expressed genes suggested that EIF2 signaling was the core pathway regulating the development of PDAC. Blocking EFI2 signaling remarkably decreased the expression of ID1 and attenuated the tumor-formation related phenotypes. These observations confirmed that ID1 was regulated by EIF2 signaling and was the critical determinator of PDAC development and progression. This study suggests that ID1 is a potential malignant biomarker of PDAC in both mouse models and human and detecting and targeting ID1 may be a promising strategy to treat or even rescue PDAC.

PLXND1/SEMA3E Promotes Epithelial-Mesenchymal Transition Partly via the PI3K/AKT-Signaling Pathway and Induces Heterogenity in Colorectal Cancer

Colorectal cancer (CRC) is a major cause of cancer-related deaths. Metastasis is enhanced through epithelial-mesenchymal transition (EMT), a process primarily induced by the transforming growth factor beta (TGF-β)-mediated canonical Smad pathway. This study focused on plexin D1 (PLXND1), a chemoreceptor for the ligand SEMA3E to mechanosensory, showing that PLXND1 induces EMT via activation of the PI3K/AKT pathway in CRC cells. The findings showed that PLXND1-knockdown decreases cell migration and invasion significantly, and that the binding of p61-SEMA3E to the PLXND1 enhances the invasiveness and migration through EMT. Furin inhibitor suppresses EMT, decreasing cell migration and invasion. Furin cleaves full-length SEMA3E and converts it to p61-SEMA3E, suggesting that furin inhibitors block PLXND1 and p61-SEMA3E binding. Furin is a potential therapeutic target for the purpose of suppressing EMT by inhibiting the binding of p61-SEMA3E to PLXND1. In vivo experiments have shown that PLXND1-knockdown suppresses EMT. Mesenchymal cells labeled with ZEB1 showed heterogeneity depending on PLXND1 expression status. The high-expression group of PLXND1 in 182 CRC samples was significantly associated with poor overall survival compared with the low-expression group (P = 0.0352, median follow-up period of 60.7 months) using quantitative real-time polymerase chain reaction analysis. Further research is needed to determine whether cell fractions with a different expression of PLXND1 have different functions.

SOX4 promotes high-glucose-induced inflammation and angiogenesis of retinal endothelial cells by activating NF-κB signaling pathway

Diabetic retinopathy (DR) is a type of main microvascular complication of diabetes mellitus (DM) and an important factor that causes blindness in adults. SOX4 is a transcription factor expressed in the pancreas and is essential for normal endocrine pancreatic development. However, the effect and the regulatory mechanism of SOX4 on DR have not been reported. In the present study, upregulation of SOX4 was found in DM patients, particularly in DR patients and mice models. The in vitro experiments showed that SOX4 depletion increased the viability and inhibited the inflammation level of human retinal endothelial cells (HRCECs) induced by high glucose. Besides, SOX4 knockdown inhibited the migration and angiogenesis of HRCECs upon high glucose treatment. Mechanically, depletion of SOX4 inhibited the NF-κB pathway. Therefore, SOX4 could serve as a promising target for DR treatment.

Coumarin-Palladium(II) Complex Acts as a Potent and Non-Toxic Anticancer Agent against Pancreatic Carcinoma Cells

Pancreatic carcinoma still represents one of the most lethal malignant diseases in the world although some progress has been made in treating the disease in the past decades. Current multi-agent treatment options have improved the overall survival of patients, however, more effective treatment strategies are still needed. In this paper we have characterized the anticancer potential of coumarin-palladium(II) complex against pancreatic carcinoma cells. Cells viability, colony formation and migratory potential of pancreatic carcinoma cells were assessed in vitro, followed by evaluation of apoptosis induction and in vivo testing on zebrafish. Presented results showed remarkable reduction in pancreatic carcinoma cells growth both in vitro and in vivo, being effective at micromolar concentrations (0.5 μM). Treatments induced apoptosis, increased BAX/BCL-2 ratio and suppressed the expression of SOX9 and SOX18, genes shown to be significantly up-regulated in pancreatic ductal adenocarcinoma. Importantly, treatments of the zebrafish-pancreatic adenocarcinoma xenografts resulted in significant reduction in tumor mass, without provoking any adverse toxic effects including hepatotoxicity. Presented results indicate the great potential of the tested compound and the perspective of its further development towards pancreatic cancer therapy.

Circ_0089823 reinforces malignant behaviors of non-small cell lung cancer by acting as a sponge for microRNAs targeting SOX4. Neoplasia 2021;23:887-897. [PMID: 34311177 PMCID: PMC8326602 DOI: 10.1016/j.neo.2021.06.011]

In recent years, increasing evidence indicates the significant roles of circRNAs in carcinogenesis. However, their roles in lung cancer remain largely unclear. We profiled the circRNA expression in 10 paired non-small cell lung cancer (NSCLC) and adjacent non-cancer tissues using high-throughput sequencing. A total of 183 up-regulated and 428 down-regulated circRNAs were identified in the NSCLC tissues (fold change ≥ 2, P < 0.05). Circ_0089823, an up-regulated circRNA (5.4-fold, P = 0.0017), was further investigated through loss-of-function and gain-of-function. The circ_0089823 level in NSCLC samples was related to the gender, tumor size, pathological type, TNM stage and smoking history. Knockdown of circ_0089823 suppressed cell proliferation, induced cell cycle arrest and apoptosis of NSCLC cells in vitro. Additionally, circ_0089823-silenced xenografts grew much slowly. On the contrary, its over-expression promoted the malignant behaviors of NSCLC cells. Furthermore, SOX4, a tumor-promoting transcription factor, was highly expressed in NSCLC tissues and positively regulated by circ_0089823. Bioinformatic analysis revealed several potential binding sites for miR-507, miR-557, miR-579-3p and miR-1287-5p in circ_0089823 and SOX4 3'-untranslated region, which was later confirmed by luciferase reporter assay. Interestingly, silencing SOX4 countervailed the effects of circ_0089823 over-expression on NSCLC cells. Here, we revealed that circ_0089823 might act as a sponge of microRNAs targeting SOX4, thus increasing the expression of SOX4, thereby reinforcing the malignant behaviors of NSCLC cells. This study indicates that circ_0089823 has the potential to become a candidate target for NSCLC treatment.

LncRNA SNHG17 regulates cell proliferation and invasion by targeting miR-338-3p/SOX4 axis in esophageal squamous cell carcinoma

Small nucleolar RNA host gene 17 (SNHG17), a novel functional long noncoding RNA, has been demonstrated to play an essential role in the oncogenesis of several tumors. However, for esophageal squamous cell carcinoma (ESCC) the expression pattern and detailed function of SNHG17 are largely unknown. Hence, we conducted this study to explore potential roles and underlying oncogenic mechanisms for SNHG17 in ESCC progression. Results demonstrated SNHG17 to be markedly upregulated in ESCC. Knockdown of SNHG17 significantly suppressed ESCC cell proliferation, invasion, and epithelial-mesenchymal transition in vitro and tumor growth in vivo. Online database software analysis found miR-338-3p to interact with SNHG17 with the level of miR-338-3p negatively correlated with SNHG17 levels in ESCC samples. Further, miR-338-3p was found to directly target SRY-box transcription factor 4 (SOX4) in ESCC cells. Mechanistic analysis suggested that SNHG17 acts as an endogenous "sponge" competing with miR-338-3p to regulate SOX4, thereby promoting tumor progression. These results suggest that these molecular interactions may be potential therapeutic targets for ESCC.

Role of PLEXIND1/TGFβ Signaling Axis in Pancreatic Ductal Adenocarcinoma Progression Correlates with the Mutational Status of KRAS

Simple Summary

Pancreatic cancer is among the most lethal cancers. The expression of PLEXIND1, a receptor, is upregulated in many cancers (including pancreatic cancer). Traditionally, PLEXIND1 is known to be involved in neuron development and mediate semaphorin signaling. However, its role and signaling in cancer is not fully understood. In our study, we present a new mechanism through which PLEXIND1 mediates its roles in cancer. For the first time, we demonstrate that it can function as a transforming growth factor beta coreceptor and modulate SMAD3 signaling. Around 90% of pancreatic cancer patients have mutant KRAS. Our work suggests that PLEXIND1 functions differently in pancreatic cancer cell lines, and the difference correlates with KRAS mutational status. Additionally, we demonstrate a novel peptide based therapeutic approach to target PLEXIND1 in cancer cells. Our work is valuable to both neuroscience and cancer fields, as it demonstrates an association between two previously unrelated signaling pathways.

Abstract

PLEXIND1 is upregulated in several cancers, including pancreatic ductal adenocarcinoma (PDAC). It is an established mediator of semaphorin signaling, and neuropilins are its known coreceptors. Herein, we report data to support the proposal that PLEXIND1 acts as a transforming growth factor beta (TGFβ) coreceptor, modulating cell growth through SMAD3 signaling. Our findings demonstrate that PLEXIND1 plays a pro-tumorigenic role in PDAC cells with oncogenic KRAS (KRAS^mut). We show in KRAS^mut PDAC cell lines (PANC-1, AsPC-1,4535) PLEXIND1 downregulation results in decreased cell viability (in vitro) and reduced tumor growth (in vivo). Conversely, PLEXIND1 acts as a tumor suppressor in the PDAC cell line (BxPC-3) with wild-type KRAS (KRAS^wt), as its reduced expression results in higher cell viability (in-vitro) and tumor growth (in vivo). Additionally, we demonstrate that PLEXIND1-mediated interactions can be selectively disrupted using a peptide based on its C-terminal sequence (a PDZ domain-binding motif), an outcome that may possess significant therapeutic implications. To our knowledge, this is the first report showing that (1) PLEXIND1 acts as a TGFβ coreceptor and mediates SMAD3 signaling, and (2) differential roles of PLEXIND1 in PDAC cell lines correlate with KRAS^mut and KRAS^wt status.

Silencing of circRNA circ_0001666 Represses EMT in Pancreatic Cancer Through Upregulating miR-1251 and Downregulating SOX4

Background

Pancreatic cancer (PC) is an aggressive malignancy and has a poor prognosis. Although emerging research has revealed that circular RNAs (circRNAs) are crucial modulators that control tumor development and metastasis, their functional involvement in PC has not been well characterized. Here, we examined whether and how circRNA circ_0001666 governs epithelial-mesenchymal transition (EMT) in PC.

Methods

We investigated the effects of circ_0001666 on EMT and PC cell invasion by gain- and loss-of-function assays. We also explored the mechanisms underlying the functions of circ_0001666 in PC cells.

Results

We found that circ_0001666 is highly expressed in PC tissues and PC cell lines. Patients with high circ_0001666 expression had shorter survival times. In vitro and in vivo experiments have demonstrated that upregulation of circ_0001666 facilitates PC cell proliferation, EMT and invasiveness, whereas knockdown of circ_0001666 exhibits opposite functions. Moreover, circ_0001666 is able to bind to miR-1251, thus increasing the expression of SOX4, which is a direct downstream effector of miR-1251. The oncogenic effects of circ_0001666 on EMT and PC cell invasion were rescued by miR-1251 overexpression.

Conclusions

These results suggested that circ_0001666 acts as an oncogenic circRNA to promote EMT and invasion of PC cells through sponging miR-1251, and indicated that circ_0001666 could be explored as a potential therapeutic target for PC.

Prognostic Value of PLXND1 and TGF-β1 Coexpression and Its Correlation With Immune Infiltrates in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with no curative treatments. Plexin D1 (PLXND1) is a cellular receptor whose functions have been explored in several human cancers; however, the critical roles of PLXND1 in HCC have rarely been probed. Therefore, the present study attempted to elucidate the expression pattern, prognostic significance, and potential roles of PLXND1 in HCC. We found that PLXND1 expression in HCC tissues was significantly higher compared with normal liver tissue from Gene Expression Profiling Interactive Analysis (GEPIA) and Integrative Molecular Database of Hepatocellular Carcinoma (HCCDB) databases. This result was further validated by immunohistochemistry staining (IHC) using tissue microarrays, which contained 216 HCC cases collected from our hospital. Additionally, PLXND1 expression showed a significant correlation with several clinical characteristics, including tumor grade and tumor hemorrhage (TH). Moreover, TISIDB and GEPIA databases were used to investigate the roles of PLXND1 in tumor-immune system interactions in HCC. As an immunoinhibitor, transforming growth factor-beta (TGF-β1) displayed the greatest correlations with PLXND1 in HCC. Finally, Kaplan-Meier curves and Cox analysis were conducted to further examine the potential clinical value of PLXND1 in HCC. We described a subclassification of HCC based on PLXND1 and TGF-β1 expression, which could be used to predict clinical outcomes and patient prognosis. Taken together, the results of this study indicate that PLXND1 might be a promising prognostic biomarker and potential therapeutic target in HCC.

Detection of molecular signatures and pathways shared in inflammatory bowel disease and colorectal cancer: A bioinformatics and systems biology approach

Emerging evidence indicates IBD is a risk factor for the increasing incidence of colorectal cancer (CRC) development. We used a system biology approach to identify common molecular signatures and pathways that interact between IBD and CRC and the indispensable pathological mechanisms. First, we identified 177 common differentially expressed genes (DEGs) between IBD and CRC. Gene set enrichment, protein-protein, DEGs-transcription factors, DEGs-microRNAs, protein-drug interaction, gene-disease association, Gene Ontology, pathway enrichment analyses were conducted to these common genes. The inclusion of common DEGs with bimolecular networks disclosed hub proteins (LYN, PLCB1, NPSR1, WNT5A, CDC25B, CD44, RIPK2, ASAP1), transcription factors (SCD, SLC7A5, IKZF3, SLC16A1, SLC7A11) and miRNAs (mir-335-5p, mir-26b-5p, mir-124-3p, mir-16-5p, mir-192-5p, mir-548c-3p, mir-29b-3p, mir-155-5p, mir-21-5p, mir-15a-5p). Analysis of the interaction between protein and drug discovered ASAP1 interacts with cysteine sulfonic acid and double oxidized cysteine drug compounds. Gene-disease association analysis retrieved ASAP1 also associated with pulmonary and bladder neoplasm diseases.

Epigenetic silencing of microRNA-335 contributes to nasopharyngeal carcinoma metastasis

BACKGROUND

MircoRNA-335 (miR-335), a member of mircoRNAs (miRNAs) family, has been found to be correlated with tumor invasion and metastasis. In this study, we aimed to detect the effect of miR-335 methylation on metastasis of nasopharyngeal carcinoma.

METHODS

RT-PCR and methylation-specific PCR were applied to detect the expression levels of miR-335 and miR-335 methylation in nasopharyngeal carcinoma tissues.

RESULTS

The levels of miR-335 expression were significantly lower in nasopharyngeal cancer tissues with promoter methylation, compared to those with promoter unmethylation. The levels of miR-335 gene promoter methylation were higher in 14 (46.7%) out of 30 nasopharyngeal cancer tissues. Furthermore, the patients with cervical lymph node metastasis had higher methylation rate in miR-335 promoter (66.7% versus 16.7%) than those without cervical lymph node metastasis.

CONCLUSION

Gene methylation contributes the expression of miR-335 in nasopharyngeal carcinoma. The expression of miR-335 methylation is correlated with the metastasis of nasopharyngeal carcinoma.

SOX4: Epigenetic regulation and role in tumorigenesis

Sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) is a member of the group C subfamily of SOX transcription factors and promotes tumorigenesis by endowing cancer cells with survival, migratory, and invasive capacities. Emerging evidence has highlighted an unequivocal role for this transcription factor in mediating various signaling pathways involved in tumorigenesis, epithelial-to-mesenchymal transition (EMT), and tumor progression. During the last decade, numerous studies have highlighted the epigenetic interplay between SOX4-targeting microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and SOX4 and the subsequent modulation of tumorigenesis, invasion and metastasis. In this review, we summarize the current state of knowledge about the role of SOX4 in cancer development and progression, the epigenetic regulation of SOX4, and the potential utilization of SOX4 as a diagnostic and prognostic biomarker and its depletion as a therapeutic target.

Expression of Semaphorin 3B (SEMA3B) in Various Grades of Endometrial Cancer

BACKGROUND SEMA3B is known as an inhibitor of angiogenesis and cell proliferation. During carcinogenesis, the loss of SEMA3B function is observed, which results in the progression of neoplastic changes. The aim of this study was to evaluate the expression profile of SEMA3B in endometrial cancer (G1-G3) in comparison to the control group and to assess whether the observed changes in expression could become a molecular marker in endometrial cancer. MATERIAL AND METHODS The study group consisted of 45 patients diagnosed with endometrial cancer (G1, 17; G2, 15; G3, 13). The control group included 15 patients. SEMA3B expression was assessed using the immunohistochemical method. Statistical analysis was carried out using the Statistica 12 PL program (StatSoft, USA). It included the Kruskal-Wallis test and post hoc Dunn's test (p<0.05). RESULTS Statistically significant differences in the level of SEMA3B expression were observed between all analyzed groups. The expression pattern of SEMA3B was as follows: cancer cells G1>G2>G3; endothelial cells: G3>G1>G2; stromal cells: G2>G1>G3. CONCLUSIONS Analysis of the SEMA3B expression profile shows the complexity of neoplastic transformation, which confirms the different expression of SEMA3B in endometrial cancer cells and endothelial cells. The present results and data in the literature data suggest that SEMA3B expression indicates the progression of carcinogenesis in the context of endometrial cancer.

Divergent roles of Plexin D1 in cancer

Plexin D1 belongs to a family of transmembrane proteins called plexins. It was characterized as a receptor for semaphorins and is known to be essential for axonal guidance and vascular patterning. Mutations in Plexin D1 have been implicated in pathologic conditions such as truncus arteriosus and Möbius syndrome. Emerging data show that expression of Plexin D1 is deregulated in several cancers; it can support tumor development by aiding in tumor metastasis and EMT; and conversely, it can act as a dependence receptor and stimulate cell death in the absence of its canonical ligand, semaphorin 3E. The role of Plexin D1 in tumor development and progression is thereby garnering research interest for its potential as a biomarker and as a therapeutic target. In this review, we describe its discovery, structure, mutations, role(s) in cancer, and therapeutic potential.

The role of SOX family members in solid tumours and metastasis

Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer development. Here, we review the role of the SOX family in breast cancer, prostate cancer, renal cell carcinoma, thyroid cancer, brain tumours, gastrointestinal and lung tumours as well as the entailing therapeutic implications. The SOX family consists of more than 20 members that mediate DNA binding by the HMG domain and have regulatory functions in development, cell-fate decision, and differentiation. SOX2, SOX4, SOX5, SOX8, SOX9, and SOX18 are up-regulated in different cancer types and have been found to be associated with poor prognosis, while the up-regulation of SOX11 and SOX30 appears to be favourable for the outcome in other cancer types. SOX2, SOX4, SOX5 and other SOX members are involved in tumorigenesis, e.g. SOX2 is markedly up-regulated in chemotherapy resistant cells. The SoxF family (SOX7, SOX17, SOX18) plays an important role in angio- and lymphangiogenesis, with SOX18 seemingly being an attractive target for anti-angiogenic therapy and the treatment of metastatic disease in cancer. In summary, SOX transcription factors play an important role in cancer progression, including tumorigenesis, changes in the tumour microenvironment, and metastasis. Certain SOX proteins are potential molecular markers for cancer prognosis and putative potential therapeutic targets, but further investigations are required to understand their physiological functions.

Transcriptome-wide association study identifies multiple genes and pathways associated with pancreatic cancer

AIM

To identify novel candidate genes for pancreatic cancer.

METHODS

We performed a transcriptome-wide association study (TWAS) analysis of pancreatic cancer (PC). GWAS summary data were driven from the published studies of PC, totally involving 558 542 SNPs in 1896 individuals with pancreatic cancer and 1939 healthy controls. FUSION software was applied to the PC GWAS summary data for tissue-related TWAS analysis, including whole blood, peripheral blood, adipose, and pancreas. The functional relevance of identified genes with PC was further validated by Oncomine, STRING, and CluePedia tool.

RESULTS

Transcriptome-wide association study analysis identified 19 genes significantly associated with PC, such as LRP5L (P value = 5.21 × 10^-5 ), SOX4 (P value = 3.2 × 10^-4 ), and EGLN3 (P value = 6.2 × 10^-3 ). KEGG pathway enrichment analysis detected several PC-associated pathways, such as One carbon pool by folate (P value = 1.60 × 10^-16 ), Cell cycle (P value = 1.27 × 10^-7 ), TGF-beta signaling pathway (P value = 4.64 × 10^-6 ). Further comparing the 19 genes with previously identified overexpressed genes in PC patients found one overlapped gene SOX4.

CONCLUSION

We identified some novel candidate genes and pathways associated with PC. Our results provide novel clues for the genetic mechanism studies of pancreatic cancer.

Overexpression of Semaphorin-3E enhances pancreatic cancer cell growth and associates with poor patient survival

Semaphorin-3E (Sema3E) is a member of an axon guidance gene family, and has recently been reported to contribute to tumor progression and metastasis. However, its role in pancreatic cancer is yet unknown and uncharacterized. In this study, we showed that Sema3E is overexpressed in human pancreatic cancer, and that high Sema3E levels are associated with tumor progression and poor survival. Interestingly, we also observed Sema3E expression in the nucleus, even though Sema3E is reported to be a secreted protein. Overexpression of Sema3E in pancreatic cancer cells promoted cell proliferation and migration in vitro, and increased tumor incidence and growth in vivo. Conversely, knockout of Sema3E suppressed cancer cell proliferation and migration in vitro, and reduced tumor incidence and size in vivo. Moreover, Sema3E induced cell proliferation via acting through the MAPK/ERK pathway. Collectively, these results reveal an undiscovered role of Sema3E in promoting pancreatic cancer pathogenesis, suggesting that Sema3E may be a suitable prognostic marker and therapeutic target for pancreatic cancer.

Androgen receptor transcriptionally regulates semaphorin 3C in a GATA2-dependent manner

The androgen receptor (AR) is a member of the nuclear receptor superfamily of transcription factors and is central to prostate cancer (PCa) progression. Ligand-activated AR engages androgen response elements (AREs) at androgen-responsive genes to drive the expression of gene batteries involved in cell proliferation and cell fate. Understanding the transcriptional targets of the AR has become critical in apprehending the mechanisms driving treatment-resistant stages of PCa. Although AR transcription regulation has been extensively studied, the signaling networks downstream of AR are incompletely described. Semaphorin 3C (SEMA3C) is a secreted signaling protein with roles in nervous system and cardiac development but can also drive cellular growth and invasive characteristics in multiple cancers including PCa. Despite numerous findings that implicate SEMA3C in cancer progression, regulatory mechanisms governing its expression remain largely unknown. Here we identify and characterize an androgen response element within the SEMA3C locus. Using the AR-positive LNCaP PCa cell line, we show that SEMA3C expression is driven by AR through this element and that AR-mediated expression of SEMA3C is dependent on the transcription factor GATA2. SEMA3C has been shown to promote cellular growth in certain cell types so implicit to our findings is the discovery of direct regulation of a growth factor by AR. We also show that FOXA1 is a negative regulator of SEMA3C. These findings identify SEMA3C as a novel target of AR, GATA2, and FOXA1 and expand our understanding of semaphorin signaling and cancer biology.

MicroRNA-216b-5p Functions as a Tumor-suppressive RNA by Targeting TPT1 in Pancreatic Cancer Cells

MicroRNAs (miRNAs) are increasingly recognized as being involved in pancreatic cancer progression by directly regulating the expression of their targets. In this study, we showed that miR-216b-5p expression was significantly decreased in pancreatic cancer tissues and cell lines. In addition, low miR-216b-5p expression was significantly associated with large tumor size and advanced TNM stage. Meanwhile, both Kaplan-Meier and multivariate survival analysis showed that decreased miR-216b-5p expression was associated with overall survival. miR-216b-5p over-expression repressed pancreatic cancer cell proliferation and induced cell cycle arrest and cell apoptosis in vitro and inhibited tumorigenesis in vivo. The translationally controlled tumor protein (TPT1) was identified as a novel direct target of miR-216b-5p. miR-216b-5p up-regulation suppressed TPT1 expression. Moreover, TPT1 mRNA expression levels were increased in pancreatic cancer tissues, and were inversely correlated with miR-216b-5p expression. TPT1 down-regulation had similar effects as miR-216b-5p up-regulation on pancreatic cancer cell progression. The restoration of TPT1 reversed the effect of miR-216b-5p on pancreatic cancer cell progression. Furthermore, we found that miR-216b-5p up-regulation suppressed Pim-3, Cyclin B1, p-Bad and Bcl-xL protein expression. However, the effect of miR-216b-5p up-regulation was partly reversed by TPT1 up-regulation in vitro. Taken together, our findings suggested that miR-216b-5p functions as a potential tumor suppressor by regulating TPT1 in pancreatic cancer cells, and it may represent a potential therapeutic target for patients with pancreatic cancer.

SOX4: Joining the Master Regulators of Epithelial-to-Mesenchymal Transition?

The epithelial-to-mesenchymal transition (EMT) is an important developmental program exploited by cancer cells to gain mesenchymal features. Transcription factors globally regulating processes during EMT are often referred as 'master regulators' of EMT, and include members of the Snail and ZEB transcription factor families. The SRY-related HMG box (SOX) 4 transcription factor can promote tumorigenesis by endowing cells with migratory and invasive properties, stemness, and resistance to apoptosis, thereby regulating key aspects of the EMT program. We propose here that SOX4 should also be considered as a master regulator of EMT, and we review the molecular mechanisms underlying its function.

MiR-129-5p suppresses gastric cancer cell invasion and proliferation by inhibiting COL1A1

Gastric cancer (GC) is one of the most lethal cancers worldwide. In this study, we aimed to explore the role of miR-129-5p, a newly identified miR-129 member, in GC cells as well as the potential mechanism of action. The results of reverse transcription - qualitative polymerase chain reaction (RT-qPCR) and Western Blot showed that miR-129 was downregulated in GC cells compared with normal ones. Using MTT, colony formation, wound healing assay, and a Transwell assay, we evaluated the proliferation, migration, and invasion abilities of transfected cells, and confirmed miR-129-5p as a tumor suppressor in GC. After a microarray analysis comparing different gene expressions in miR-129-5p transfected SGC-7901 cells, COL1A1 was selected for biggest fold-change and potential target of miR-129-5p predicted by TargetScan. Measured by RT-qPCR and Western blot, COL1A1 turned out to be upregulated in GC tissues and cells. We further confirmed the targeting relationship between miR-129-5p and COL1A1 by dual luciferase assay. By manipulating the expression of COL1A1 in SGC-7901 cells, cell proliferation, migration, and invasion were examined and the tumor-promoting function of COL1A1 was validated. Moreover, co-transfection of miR-129-5p mimics and COL1A1 attenuated the tumor-promoting effects induced by a single-transfection of COL1A1, and miR-129-5p inhibitor counteracted the tumor-suppressing effects of COL1A1 siRNA. Collectively, the data demonstrate the important functions of the miR-129-5p-COL1A1 axis in GC: miR-129-5p suppresses GC cell proliferation, migration, and invasion, by selectively inhibiting COL1A1. This study provides new therapeutic targets for the clinical treatment of GC.

SoxC Transcription Factors Promote Contralateral Retinal Ganglion Cell Differentiation and Axon Guidance in the Mouse Visual System

Transcription factors control cell identity by regulating diverse developmental steps such as differentiation and axon guidance. The mammalian binocular visual circuit is comprised of projections of retinal ganglion cells (RGCs) to ipsilateral and contralateral targets in the brain. A transcriptional code for ipsilateral RGC identity has been identified, but less is known about the transcriptional regulation of contralateral RGC development. Here we demonstrate that SoxC genes (Sox4, 11, and 12) act on the progenitor-to-postmitotic transition to implement contralateral, but not ipsilateral, RGC differentiation, by binding to Hes5 and thus repressing Notch signaling. When SoxC genes are deleted in postmitotic RGCs, contralateral RGC axons grow poorly on chiasm cells in vitro and project ipsilaterally at the chiasm midline in vivo, and Plexin-A1 and Nr-CAM expression in RGCs is downregulated. These data implicate SoxC transcription factors in the regulation of contralateral RGC differentiation and axon guidance.

Meta-analysis of the prognostic value of abnormally expressed lncRNAs in hepatocellular carcinoma

Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in hepatocellular carcinoma (HCC), and may have the potential to serve as prognostic markers. In this study, a meta-analysis was conducted to systematically evaluate the prognostic value of various lncRNAs in HCC. Eligible literatures were systematically collected from PubMed, Embase, Web of Science, and Cochrane Library (up to December 30, 2015). The main outcomes including overall survival, relapse-free survival, and disease-free survival were analyzed. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using random- or fixed-effects models. A total of 2,991 patients with HCC in People's Republic of China from 27 studies were included in the analysis. The level of lncRNAs showed a significant association with clinical outcomes. Abnormally elevated lncRNA transcription level predicted poor overall survival (HR: 1.68, 95% CI: 1.20-2.34, P=0.002; I (2)=75.5%, P=0.000) and relapse-free survival (HR: 2.08, 95% CI: 1.65-2.61, P<0.001; I (2)=24.0%, P=0.215), while no association was observed with disease-free survival of HCC patients (HR: 1.39, 95% CI: 0.51-3.78, P=0.524; I (2)=81.3%, P=0.005). Subgroup analysis further showed that lncRNA transcription level was significantly associated with tumor size (relative risk [RR]: 1.19, 95% CI: 1.01-1.39, P=0.035), microvascular invasion (RR: 1.44, 95% CI: 1.10-1.89, P=0.009), and portal vein tumor thrombus (RR: 1.50, 95% CI: 1.03-2.20, P=0.036). Publication bias and sensitivity analysis further confirmed the stability of our results. Our present meta-analysis indicates that abnormal lncRNA transcription level may serve as a promising indicator for prognostic evaluation of patients with HCC in People's Republic of China.

SOX-mediated molecular crosstalk during the progression of tumorigenesis

SOX family transcription factor has emerged as a double-edged sword relating to tumorigenesis and metastasis. Multiple studies have revealed different expression patterns and contradictory roles of SOX factors in the tumor initiation and progression. The aberrant expression of SOX factors is regulated by copy number alteration, methylation modulation, microRNAs, transcription factors and post-translational modification. This review summarizes the role of SOX factors in molecular interactions and signaling pathways during different steps of carcinogenesis, such as CSCs stemness maintenance, EMT occurrence, cell invasion, cell proliferation and apoptosis. The Wnt signaling pathway is also shown to provide vital intermediate signaling transduction. We believe that SOX family proteins may be used as prognostic markers for human clinical therapy, and novel therapy strategies targeting SOX factors should be explored in future clinical applications.

TMEM2 Is a SOX4-Regulated Gene That Mediates Metastatic Migration and Invasion in Breast Cancer

The developmental transcription factor SOX4 contributes to the metastatic spread of multiple solid cancer types, but its direct target genes that mediate cancer progression are not well defined. Using a systematic molecular and genomic approach, we identified the TMEM2 transmembrane protein gene as a direct transcriptional target of SOX4. TMEM2 was transcriptionally activated by SOX4 in breast cancer cells where, like SOX4, TMEM2 was found to mediate proinvasive and promigratory effects. Similarly, TMEM2 was sufficient to promote metastatic colonization of breast cancer cells and its expression in primary breast tumors associated with a higher likelihood of metastatic relapse. Given earlier evidence that genetic inactivation of SOX4 or TMEM2 yield similar defects in cardiac development, our findings lead us to propose that TMEM2 may not only mediate the pathologic effects of SOX4 on cancer progression but also potentially its contributions to embryonic development. Cancer Res; 76(17); 4994-5005. ©2016 AACR.

KRAS mutation status is associated with specific pattern of genes expression in pancreatic adenocarcinoma

AIMS

To evaluate potential differences at a molecular level between KRAS mutant tumors (MT) and KRAS wild-type (WT) pancreatic tumors and the biological and prognostic significance of different KRAS mutations.

MATERIALS & METHODS

Expression of a panel of 29 genes was analyzed in KRAS WT and MT tumors. Effects of KRAS mutation and gene expression levels were assessed on patients' survival.

RESULTS

MUC6 (p = 0.009), HGF (p = 0.011), VEGFR-2 (p = 0.020) and VEGFB (p = 0.026) were significantly more expressed and SMAD4 was less suppressed (p = 0.003) in WT KRAS. Contrariwise, SHH (p = 0.012) and IHH (p = 0.031) were more expressed in MT KRAS patients. No OS difference was found between WT and MT KRAS tumors.

CONCLUSION

KRAS mutation status seems to identify two different subtypes of pancreatic ductal adenocarcinoma with similar outcome but distinct molecular features and probably different therapeutic targets.

MicroRNA-338-3p suppresses metastasis of lung cancer cells by targeting the EMT regulator Sox4

Metastasis remains the leading cause of the majority of cancer-related mortality. MicroRNAs (miRNAs) have frequently emerged as tumor metastatic regulator by acting on multiple signaling pathways. In the present study, we demonstrated that miR-338-3p was significantly downregulated in highly metastatic NSCLC cell lines and clinical metastatic tissues. Then, we found that introduction of miR-338-3p significantly suppressed the migration and invasion of lung cancer cells both in vitro and in vivo, suggesting that miR-338-3p may be a novel tumor suppressor. Further studies indicated that the EMT-related transcription factor Sox4 was one direct target gene of miR-338-3p, evidenced by the direct binding of miR-338-3p with the 3'untranslated region (3'UTR) of Sox4. Furthermore, miR-338-3p could decrease the expression of Sox4 both at mRNA and protein levels. Notably, the EMT marker E-cadherin or vimentin, a downstream regulator of Sox4, was also down-regulated or up-regulated upon miR-338-3p treatment. Additionally, over-expressing or silencing Sox4 could elevate or inhibit the migration and invasion of lung cancer cells, parallel to the effect of miR-338-3p on the lung cancer cells. Meanwhile, knockdown of Sox4 reversed the enhanced migration and invasion mediated by miR-338-3p. These results indicated that miR-338-3p suppressed the migration and invasion of NSCLC cells through targeting Sox4 involving in the EMT process. Thus, our finding provides new insight into the mechanism of NSCLC progression. Therapeutically, miR-338-3p may serve as a potential target in the treatment of human lung cancer.

MiR-129-3p promotes docetaxel resistance of breast cancer cells via CP110 inhibition

Docetaxel is commonly used as an effective chemotherapeutic agent in breast cancer treatment, but the underlying mechanisms of drug resistance are not fully understood. The purpose of this study was to investigate the possible role of miR-129-3p in breast cancer cell resistance to docetaxel. MiR-129 and miR-129-3p inhibitor were transfected into breast cancer cells to investigate their effects on chemoresistance to docetaxel. The function of miR-129-3p was evaluated by apoptosis, cell proliferation, and cell cycle assays. We found that miR-129-3p was up-regulated in MDA-MB-231/Doc cells, concurrent with CP110 down-regulation, compared to the parental MDA-MB-231 cells. In vitro drug sensitivity assays demonstrated that miR-129-3p inhibition sensitized MDA-MB-231/Doc and MCF-7 cells to docetaxel, whereas miR-129 overexpression enhanced MDA-MB-231 and MCF-7 cell resistance to docetaxel. Ectopic miR-129 expression reduced CP110 expression and the luciferase activity of a CP110 3′ untranslated region-based reporter construct in MDA-MB-231 cells, suggesting that CP110 is a direct miR-129-3p target. We demonstrated that restoration of CP110 expression in MDA-MB-231 and MCF-7 cells by miR-129 overexpression rendered the cells sensitive to docetaxel. In a nude xenograft model, miR-129 up-regulation significantly decreased MDA-MB-231 cells’ response to docetaxel. Our findings suggest that miR-129-3p down-regulation potentially sensitizes breast cancer cells to docetaxel treatment.

SOX4 is a potential prognostic factor in human cancers: a systematic review and meta-analysis

OBJECTIVE

The aim of the this study was to analyze the status of sex-determining region Y-related high-mobility group box 4 (SOX4) expression in varied human cancers and its correlation with overall survival in patients with human cancers.

METHODS

To observe initially the expression status of SOX4 in twenty kinds of human cancers at protein database (The Human Protein Atlas). We systematically and carefully searched the studies from electronic databases and seriously identified according to eligibility criteria. The correlation between SOX4 expression and overall survival in human cancers was evaluated through Review Manager.

RESULTS

We found that SOX4 expression was significantly positive in most types of human cancer tissues, and the positive rate of SOX4 expression was about 78 % in overall cancer tissues. Furthermore, a total of 10 studies which included 1348 cancer patients were included in the final analysis. Meta-analysis showed that SOX4 overexpression was correlated with a poor overall survival and the pooled hazard ratio (HR), and corresponding 95 % confidence interval (CI) was 1.67 (95 % CI 1.01-2.78). From subgroup analyses, we present evidence that SOX4 overexpression was an unfavorable prognostic factor for colorectal cancer patients' recurrence-free survival and gastric cancer patients' overall survival, and the pooled HRs (95 % CI) were 1.73 (95 % CI 1.04-2.88) and 3.74 (95 % CI 1.04-13.45), respectively.

CONCLUSIONS

In summary, SOX4 is a potential prognostic biomarker in human cancers.

Hepatitis B virus replication and sex-determining region Y box 4 production are tightly controlled by a novel positive feedback mechanism

Hepatitis B virus (HBV) infection is a major cause of liver diseases. However, the mechanisms underlying HBV infection and pathogenesis remain largely unknown. The sex-determining region Y box 4 (Sox4) is a transcriptional factor, which preferentially regulates the development of various organs, tissues, and cancers. But, the role of Sox4 in viral infection and pathogenesis has not been elucidated. Here, we demonstrated that Sox4 is up-regulated by HBV, and revealed the mechanism by which HBV regulates Sox4 expression. First, HBV stimulates Sox4 expression through transcriptional factor Yin Yang 1 (YY1), which binds to Sox4 promoter to activate Sox4 transcriptional activity. Second, miR-335, miR-129-2 and miR-203 inhibit Sox4 expression by targeting its mRNA 3’UTR, while HBV suppresses the microRNAs expression, resulting in up-regulating Sox4 post-transcriptionally. Third, Sox4 protein is degraded by proteasome, while HBV surface protein (HBsAg) prevents Sox4 from degradation by directly interacting with the protein, thereby enhancing Sox4 production post-translationlly. More interestingly, HBV-activated Sox4 in turn facilitates HBV replication by direct binding to the viral genome via its HMG box. Thus, this study revealed a novel positive feedback mechanism by which Sox4 production and HBV replication are tightly correlated.

MicroRNA signatures in total peripheral blood of gallbladder cancer patients

MicroRNAs (miRNAs) are small non-coding RNA molecules that function as negative regulators of gene expression. Expression analysis of miRNAs can reflect the developmental lineage and differentiation state of the tumor. Thus, the miRNA profiles could play essential roles in gallbladder cancer (GBC). However, their role as novel biomarkers for the diagnosis of GBC is unclear yet. We assessed here for the first time whole-genome miRNA expression in peripheral blood samples of 40 GBC patients using microRNA microarray. We identified 11 miRNAs, which are significantly dysregulated in GBC patients in comparison to 40 healthy controls. Among these, the expression of let-7a, miR-21, miR-187, miR-143, miR-202, and miR-335 are in agreement with those measured by real-time PCR (p < 0.05). Furthermore, dysregulated miR-187, miR-143, and miR-202 demonstrate a significant correlation with clinicopathologic features (p < 0.05). Our results suggest a possible pathological relationship between the differential expression of miRNA in peripheral blood and GBC, and these dysregulated miRNAs could be novel tumor biomarkers for early detection of GBC.

MicroRNA-335 represents an independent prognostic marker in cervical cancer

Advanced stages with distant metastases or recurrence lack reliable prognostic predictor for cervical cancer. Therefore, the purpose of this study was to investigate the clinical significance of miR-335 expression in cervical cancer. A total of 138 cervical cancer samples were collected, and normal cervical tissues were obtained as matched-pair controls. The level of miR-335 expression was examined using quantitative real-time polymerase chain reaction. Overall survival was analyzed using Kaplan-Meier method. Moreover, the relationship between the expression of miR-335 and the clinicopathological features was further analyzed using Cox regression. Lower miR-335 expression was found in cervical cancer specimens. Cervical cancer patients with reduced miR-335 level had shorter survival time, compared with those with high levels of miR-335 expression (P = 0.011, log-rank = 6.458). Through Cox regression, we found that miR-335 expression was associated with the survival of cervical cancer (RR = 0.251, 95 % CI 0.095-0.663, P = 0.005). The results suggested that miR-335 expression was decreased in cervical cancer specimens and lower miR-335 expression resulted in poorer survival in patients with cervical cancer. Our findings indicated that miR-335 may be a candidate factor for predicting prognosis for cervical cancer.

SOX4 overexpression is a novel biomarker of malignant status and poor prognosis in breast cancer patients

Sex-determining region Y-related high mobility group box 4 (SOX4) has been proven to serve as a critical role in cancer development and progression. However, little is known about the pathological role of SOX4 in breast cancer patients. The purpose of this study is to measure the expression of SOX4 in breast cancer patients and to explore the clinical significance of SOX4. Using RT-PCR and Western blot, messenger RNA (mRNA) and protein expression of SOX4 were measured in breast cancer tissues and adjacent normal mammary tissues. The relationship of SOX4 expression with clinical characteristics of 148 breast cancer patients was analyzed by immunohistochemistry. In the present study, our results indicated that SOX4 mRNA and protein were highly expressed in breast cancer tissues compared with adjacent normal mammary tissues and positively correlated with clinical stage (I-II vs. III-IV; P = 0.008), T classification (T1-T2 vs. T3-T4; P = 0.013), N classification (N0-N1 vs. N2-N3; P < 0.001), M classification (M0 vs. M1; P = 0.001), estrogen receptor (negative vs. positive; P = 0.029), progesterone receptor (negative vs. positive; P = 0.004), and histological grade (G1 vs. G2-G3; P = 0.033) in breast cancer patients. Furthermore, we also found that SOX4 protein overexpression was an unfavorable prognostic factor in breast cancer patients (P < 0.001), regardless of clinical stage, tumor size, lymph node metastasis, and distant metastasis. Finally, high SOX4 expression was an independent poor prognostic factor for pancreatic patients through multivariate analysis (P = 0.033). In conclusion, SOX4 overexpression serves as an unfavorable prognostic biomarker in breast cancer patients.

Differential Expression of MicroRNAs in Tissues and Plasma Co-exists as a Biomarker for Pancreatic Cancer

OBJECTIVE

Pancreatic cancer (PC) is a lethal disease with disappointing results from current treatment modalities, suggesting that novel therapeutic strategies are urgently needed. Since microRNAs (miRNAs) are important player in biology, the clinical utility of miRNAs for designing novel therapeutics is an active area of research. The objective of the present study was to examine differentially expressed miRNAs between normal and tumor tissues, and in plasma samples obtained from PC patients, chronic pancreatitis (CP) patients and healthy subjects (HC).

MATERIAL AND METHODS

The miRNA expression profiling using formalin-fixed paraffin embedded (FFPE) tissues from normal and tumor specimens was accomplished using miRBase version 19 (LC Sciences, Houston, TX, USA). Quantitative real-time PCR (qRT-PCR) was subsequently performed in individual samples for 7 selected miRNAs. In addition, qRT-PCR was also performed for assessing the expression of 8 selected miRNAs in plasma samples.

RESULTS

A significant difference in the expressions of miR-21, miR-205, miR-155, miR-31, miR-203, miR-214 and miR-129-2 were found in tumor tissue samples. Lower expression of miR-214 was found to be associated with better overall survival. We also observed differential expression of 8 miRNAs in plasma samples of CP and PC patients compared to HC. Interestingly, over expression of miR-21, and miR-31 was noted in both tumor tissues and in the plasma.

CONCLUSION

We found deregulated expression of miRNAs that could distinguish normal from PC in two different types of samples (tissues and plasma). Interestingly, lower expression of miR-214 was found to be associated with better overall survival. Although not statistically significant, we also observed higher expression of let-7a and lower expression of miR-508 to be associated with overall better survival. We conclude that our study nicely lays the foundation for detailed future investigations for assessing the role of these miRNAs in the pathology of pancreatic cancer.

miR-129-1-3p promote BGC-823 cell proliferation by targeting PDCD2

MicroRNAs (miRNAs) are the class of small noncoding RNAs, and play an important role in the regulation of gene expression at the posttranscriptional level. In this study, we explored the effect of miR-129-1-3p on the growth and cell cycle of human gastric cancer cell line BGC-823. The miR-129-1-3p mimics or inhibitors were transfected into the BGC-823 cell line, and the cell cycle and cell growth was measured by flow cytometry and real-time cell analyzer, respectively. The possible targets of miR-129-1-3p were analyzed by quantitative real time-PCR (QRT-PCR), Western blotting and Luciferase reporter assay. The results showed that miR-129-1-3p could promote the growth and cell cycle of BGC-823 cells. Although protein expression of programmed cell death 2 (PDCD2) was not changed with miR-129-1-3p, QRT-PCR showed that expression of PDCD2 mRNA was negatively related to the miR-129-1-3p. Luciferase reporter assay revealed that PDCD2 is one of the targets of miR-129-1-3p. Our results indicated that miR-129-1-3p might promote proliferation of BGC-823 cells by targeting PDCD2.

Differentially expressed miRNAs in cancer-stem-like cells: markers for tumor cell aggressiveness of pancreatic cancer

Pancreatic cancer (PC) is one of the most deadly cancers. The higher mortality is in part due to treatment resistance and early onset of metastasis. The existence of cancer-stem-like cells (CSLCs) has been widely accepted to be responsible for tumor aggressiveness in PC. Emerging evidence suggests that CSLCs have the capacity for increased cell growth, cell migration/invasion, metastasis, and treatment resistance, which leads to poor clinical outcome. However, the molecular role of CSLCs in tumor development and progression is poorly understood. Therefore, mechanistic understanding, and targeted killing of CSLCs may provide a newer therapeutic strategy for the treatment of PC. It has been well accepted that microRNAs (miRNAs) play critical roles during tumor development and progression through deregulation of multiple genes. Moreover, deregulated expression of miRNAs may also play a key role in the regulation of CSLC characteristics and functions. Here we show that isolated CD44(+)/CD133(+)/EpCAM(+) cells (triple-marker-positive cells) from human PC cell lines, MiaPaCa-2 and L3.6pl cells, display aggressive characteristics, such as increased cell growth, clonogenicity, cell migration, and self-renewal capacity, which is consistent with overexpression of CSLC signatures/markers. We also found deregulated expression of over 400 miRNAs, including let-7, miR-30, miR-125b, and miR-335, in CSLCs. As a proof-of-concept, knockdown of miR-125b resulted in the inhibition of tumor cell aggressiveness of CSLCs (triple-marker-positive cells), consistent with the downregulation of CD44, EpCAM, EZH2, and snail. These results clearly suggest the importance of miRNAs in the regulation of CSLC characteristics, and may serve as novel targets for therapy.

miR-335 promotes mesendodermal lineage segregation and shapes a transcription factor gradient in the endoderm

Transcription factors (TFs) pattern developing tissues and determine cell fates; however, how spatio-temporal TF gradients are generated is ill defined. Here we show that miR-335 fine-tunes TF gradients in the endoderm and promotes mesendodermal lineage segregation. Initially, we identified miR-335 as a regulated intronic miRNA in differentiating embryonic stem cells (ESCs). miR-335 is encoded in the mesoderm-specific transcript (Mest) and targets the 3'-UTRs of the endoderm-determining TFs Foxa2 and Sox17. Mest and miR-335 are co-expressed and highly accumulate in the mesoderm, but are transiently expressed in endoderm progenitors. Overexpression of miR-335 does not affect initial mesendoderm induction, but blocks Foxa2- and Sox17-mediated endoderm differentiation in ESCs and ESC-derived embryos. Conversely, inhibition of miR-335 activity leads to increased Foxa2 and Sox17 protein accumulation and endoderm formation. Mathematical modeling predicts that transient miR-335 expression in endoderm progenitors shapes a TF gradient in the endoderm, which we confirm by functional studies in vivo. Taken together, our results suggest that miR-335 targets endoderm TFs for spatio-temporal gradient formation in the endoderm and to stabilize lineage decisions during mesendoderm formation.

Increased expression of microRNA-335 predicts a favorable prognosis in primary gallbladder carcinoma

Background

MicroRNAs (miRNAs) display aberrant expression patterns and functional abnormalities in many types of cancer. However, their roles in primary gallbladder carcinoma (PGC) have not been well documented. miR-335 has been demonstrated to be involved in tumorigenesis of several cancers in the digestive system. The aim of this study was to investigate the clinical significance of miR-335 in PGC.

Methods

miR-335 expression in 166 human PGC tissues and matched adjacent nondysplastic gallbladder epithelia was measured by real-time quantitative polymerase chain reaction (RT-PCR) assay.

Results

The expression level of miR-335 was significantly lower in PGC tissues than that in nondysplastic gallbladder epithelia (P<0.001). Of 166 PGC patients, 96 (57.83%) had reduced expression of miR-335. Additionally, the expression of miR-335 was significantly lower in PGC tissues with high histologic grade (P=0.02), advanced pathologic T stage (P=0.009) and clinical stage (P=0.008), and with positive lymph node metastasis (P=0.001). In univariate analysis by log-rank test, histologic grade (P=0.03), pathologic T stage (P=0.008), clinical stage (P=0.01), lymph node metastasis (P<0.001), and miR-335 expression (P<0.001) were significant prognostic factors for overall survival of PGC patients. Multivariate analysis further revealed that pathologic T stage (P=0.02), lymph node metastasis (P=0.008), and miR-335 expression (P=0.006) maintained independent prognostic influence on overall survival.

Conclusion

This study offers convincing evidence for the first time that miR-335 was downregulated in a majority of PGC patients and may be associated with the aggressive tumor behaviors. Loss of miR-335 expression may be a useful marker for clinical outcome and a therapeutic target for PGC.