Overexpression of miR-145-5p inhibits proliferation of prostate cancer cells and reduces SOX2 expression

Spinal cord injury disrupts plasma extracellular vesicles cargoes leading to neuroinflammation in the brain and neurological dysfunction in aged male mice

Aged individuals with spinal cord injury (SCI) are prevalent with increased mortality and worse outcomes. SCI can cause secondary brain neuroinflammation and neurodegeneration. However, the mechanisms contributing to SCI-induced brain dysfunction are poorly understood. Cell-to-cell signaling through extracellular vesicles (EVs) has emerged as a critical mediator of neuroinflammation, including at a distance through circulation. We have previously shown that SCI in young adult (YA) male mice leads to robust changes in plasma EV count and microRNAs (miRs) content. Here, our goal was to investigate the impact of old age on EVs and brain after SCI. At 24 h post-injury, there was no difference in particle count or size distribution between YA and aged mice. However, aged animals increased expression of EV marker CD63 with SCI. Using the Fireplex® miRs assay, Proteomics, and mass spectrometry-based Lipidomics, circulating EVs analysis identified distinct profiles of miRs, proteins, and lipid components in old and injury animals. In vitro, plasma EVs from aged SCI mice, at a lower concentration comparable to those of YA SCI mice, induced the secretion of pro-inflammatory cytokines and neuronal apoptosis. Systemic administration of plasma EVs from SCI animals was sufficient to impair general physical function and neurological function in intact animals, which is associated with pro-inflammatory changes in the brain. Furthermore, plasma EVs from young animals had rejuvenating effects on naïve aged mice. Collectively, these studies identify the critical changes in circulating EVs cargoes after SCI and in aged animals and support a potential EV-mediated mechanism for SCI-induced brain changes.

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1- extracellular signal-regulated kinase-1/2 axis

BACKGROUND

MicroRNAs (miRNAs) regulate gene expression and play a critical role in cancer physiology. However, there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer (GC).

AIM

To investigate the role and molecular mechanism of miRNA-145-5p (miR145-5p) in the progression of GC.

METHODS

Real-time polymerase chain reaction (RT-PCR) was used to detect miRNA expression in human GC tissues and cells. The ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays, respectively. Cell proliferation was measured using cell counting kit-8 and colony formation assays, and apoptosis was evaluated using flow cytometry. Expression of the epithelial-mesenchymal transition (EMT)-associated protein was determined by Western blot. Targets of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter system. Serpin family E member 1 (SERPINE1) expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical staining. The correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot analysis. The association between SERPINE1 and GC progression was also tested. A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and miR-145-5p. The mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude mice.

RESULTS

GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this miRNA. Overexpression of miR-145-5p was associated with decreased GC cell proliferation, invasion, migration, and EMT, and these effects were reversed by forcing SERPINE1 expression. Kaplan-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 expression. Nude mouse tumorigenesis experiments confirmed that miR-145-5p targets SERPINE1 to regulate extracellular signal-regulated kinase-1/2 (ERK1/2).

CONCLUSION

This study found that miR-145-5p inhibits tumor progression and is expressed in lower amounts in patients with GC. MiR-145-5p was found to affect GC cell proliferation, migration, and invasion by negatively regulating SERPINE1 levels and controlling the ERK1/2 pathway.

The Suppression of the Epithelial to Mesenchymal Transition in Prostate Cancer through the Targeting of MYO6 Using MiR-145-5p

Aberrant expression of miR-145-5p has been observed in prostate cancer where is has been suggested to play a tumor suppressor role. In other cancers, miR-145-5p acts as an inhibitor of epithelial-to-mesenchymal transition (EMT), a key molecular process for tumor progression. However, the interaction between miR-145-5p and EMT remains to be elucidated in prostate cancer. In this paper the link between miR-145-5p and EMT in prostate cancer was investigated using a combination of in silico and in vitro analyses. miR-145-5p expression was significantly lower in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of The Cancer Genome Atlas prostate adenocarcinoma (TCGA PRAD) data showed significant downregulation of miR-145-5p in prostate cancer, correlating with disease progression. Functional enrichment analysis significantly associated miR-145-5p and its target genes with EMT. MYO6, an EMT-associated gene, was identified and validated as a novel target of miR-145-5p in prostate cancer cells. In vitro manipulation of miR-145-5p levels significantly altered cell proliferation, clonogenicity, migration and expression of EMT-associated markers. Additional TCGA PRAD analysis suggested miR-145-5p tumor expression may be useful predictor of disease recurrence. In summary, this is the first study to report that miR-145-5p may inhibit EMT by targeting MYO6 in prostate cancer cells. The findings suggest miR-145-5p could be a useful diagnostic and prognostic biomarker for prostate cancer.

Prostate Cancer and microRNAs: New insights into Apoptosis

Prostate cancer (PCa) is known as one of the most prevalent malignancies globally and is not yet curable owing to its progressive nature. It has been well documented that Genetic and epigenetic alterations maintain mandatory roles in PCa development. Apoptosis, a form of programmed cell death, has been shown to be involved in a number of physiological processes. Apoptosis disruption is considered as one of the main mechanism involved in lots of pathological conditions, especially malignancy. There is ample of evidence in support of the fact that microRNAs (miRNAs) have crucial roles in several cellular biological processes, including apoptosis. Escaping from apoptosis is a common event in malignancy progression. Emerging evidence revealed miRNAs capabilities to act as apoptotic or anti-apoptotic factors by altering the expression levels of tumor inhibitor or oncogene genes. In the present narrative review, we described in detail how apoptosis dysfunction could be involved in PCa processes and additionally, the mechanisms behind miRNAs affect the apoptosis pathways in PCa. Identifying the mechanisms behind the effects of miRNAs and their targets on apoptosis can provide scientists new targets for PCa treatment.

Regulation of the TUG1/miR‑145‑5p/SOX2 axis on the migratory and invasive capabilities of melanoma cells

Melanoma is the most prevalent malignancy of cutaneous carcinomas. Taurine-upregulated gene 1 (TUG1), a lncRNA, is a pivotal regulator of cutaneous malignancies. The present study aimed to investigate the impact and possible mechanisms of action of TUG1 behind the progression of melanomas. Reverse transcription-quantitative PCR was conducted to detect the expression levels of TUG1, microRNA (miR)-145-5p and SOX2 in melanoma tissues and cell lines. Cell Counting Kit-8 (CCK-8) assays were performed to measure the proliferative ability of melanoma cells and transwell assays were used to examine the migration and invasion of melanoma cells. Dual luciferase reporter and RNA immunoprecipitation (RIP) assays were utilized to identify the interactions among TUG1, miR-145-5p and SOX2. Western blotting and immunohistochemical assays were performed to determine the expression profile of SOX2. The impact of TUG1 on melanoma tumorigenesis was assessed using tumorigenicity assays. TUG1 expression levels were elevated in melanoma tumor tissues and cell lines. Reduced TUG1 expression levels significantly inhibited the proliferative, migratory and invasive abilities of melanoma cells. The expression levels of miR-145-5p were decreased in melanoma tumor tissues and cell lines. TUG1 directly targeted miR-145-5p and downregulated miR-145-5p. Upregulation of TUG1 counteracted the promotion of the proliferative, migratory and invasive abilities of melanoma cells induced by the overexpression of miR-145-5p. SOX2 was a target of miR-145-5p and its expression was negatively regulated by miR-145-5p, while positively regulated by TUG1. TUG1 regulated SOX2 expression through sponging miR-145-5p. Silencing of TUG1 also inhibited melanoma tumorigenesis in mice. In conclusion, the TUG1/miR-145-5p/SOX2 axis regulated the migration and invasion of melanoma cells.

Mechanisms of cancer cell death induction by paclitaxel: an updated review

Chemoresistance of cancer cells is a major problem in treating cancer. Knowledge of how cancer cells may die or resist cancer drugs is critical to providing certain strategies to overcome tumour resistance to treatment. Paclitaxel is known as a chemotherapy drug that can suppress the proliferation of cancer cells by inducing cell cycle arrest and induction of mitotic catastrophe. However, today, it is well known that paclitaxel can induce multiple kinds of cell death in cancers. Besides the induction of mitotic catastrophe that occurs during mitosis, paclitaxel has been shown to induce the expression of several pro-apoptosis mediators. It also can modulate the activity of anti-apoptosis mediators. However, certain cell-killing mechanisms such as senescence and autophagy can increase resistance to paclitaxel. This review focuses on the mechanisms of cell death, including apoptosis, mitotic catastrophe, senescence, autophagic cell death, pyroptosis, etc., following paclitaxel treatment. In addition, mechanisms of resistance to cell death due to exposure to paclitaxel and the use of combinations to overcome drug resistance will be discussed.

miRNAs as molecular biomarkers for prostate cancer

MicroRNAs (miRNAs) are short noncoding RNA able to regulate specific mRNA stability, thus influencing target gene expression. Disrupted levels of several miRNA have been associated with prostate cancer, the leading cause of cancer death among men and the fifth leading cause of death worldwide. Here, we investigated whether miR-145, miR-148, and miR-185 circulating levels in plasma could be used as molecular biomarkers, to allow distinguishing between individuals with benign prostatic hyperplasia, precancerous lesion, and prostate cancer. In this study, we recruited 170 urological clinic patients with suspected prostate cancer who underwent prostate biopsy. Total RNA was isolated from plasma, and TaqMan MicroRNA assays were used to analyze miR-145, miR-185, and miR-148 expression. First, differential miRNA expression among patient groups was evaluated. Then, miRNA levels were combined with clinical assessment outcomes, including results from invasive tests, using multivariate analysis to examine their ability in discriminating among the three patient groups. Our results suggest that miRNA is a promising molecular tool for clinical management of at-risk patients.

A New Strategy to Identify ceRNA-Based CCDC144NL-AS1/SERPINE1 Regulatory Axis as a Novel Prognostic Biomarker for Stomach Adenocarcinoma via High Throughput Transcriptome Data Mining and Computational Verification

Stomach adenocarcinoma (STAD) is one of the most malignant cancers that endanger human health. There is growing evidence that competitive endogenous RNA (ceRNA) regulatory networks play an important role in various human tumors. However, the complexity and behavioral characteristics of the ceRNA network in STAD are still unclear. In this study, we constructed a ceRNA regulatory network to identify the potential prognostic biomarkers associated with STAD. The expression profile of lncRNA, miRNA, and mRNA was downloaded from The Cancer Genome Atlas (TCGA). After performing bioinformatics analysis, the CCDC144NL-AS1/hsa-miR-145-5p/SERPINE1 ceRNA network associated to STAD prognosis of STAD was obtained. The CCDC144NL-AS1/SERPINE1 axis in the ceRNA network was identified by correlation analysis and considered as a clinical prognosis model by Cox regression analysis. In addition, methylation analysis indicated that the abnormal upregulation of CCDC144NL-AS1/SERPINE1 axis might be related to the aberrant methylation of some sites, and immune infiltration analysis suggested that CCDC144NL-AS1/SERPINE1 axis probably influences the alteration of tumor immune microenvironment and the occurrence and development of STAD. In particular, the CCDC144NL-AS1/SERPINE1 axis based on the ceRNA network constructed in the present study might be an important novel factor correlating with the diagnosis and prognosis of STAD.

Omics- and Pharmacogenomic Evidence for the Prognostic, Regulatory, and Immune-Related Roles of PBK in a Pan-Cancer Cohort

PDZ-binding kinase (PBK) is known to regulate tumor progression in some cancer types. However, its relationship to immune cell infiltration and prognosis in different cancers is unclear. This was investigated in the present study by analyzing data from TCGA, GEO, GETx, TIMER, CPTAC, GEPIA2, cBioPortal, GSCALite, PROGNOSCAN, PharmacoDB, STRING, and ENCORI databases. PBK was overexpressed in most tumors including adenocortical carcinoma (hazard ratio [HR] = 2.178, p < 0.001), kidney renal clear cell carcinoma (KIRC; HR = 1.907, p < 0.001), kidney renal papillary cell carcinoma (HR = 3.024, p < 0.001), and lung adenocarcinoma (HR = 1.255, p < 0.001), in which it was associated with poor overall survival and advanced pathologic stage. PBK methylation level was a prognostic marker in thyroid carcinoma (THCA). PBK expression was positively correlated with the levels of BIRC5, CCNB1, CDC20, CDK1, DLGAP5, MAD2L1, MELK, PLK1, TOP2A, and TTK in 32 tumor types; and with the levels of the transcription factors E2F1 and MYC, which regulate apoptosis, the cell cycle, cell proliferation and invasion, tumorigenesis, and metastasis. It was also negatively regulated by the microRNAs hsa-miR-101-5p, hsa-miR-145-5p, and hsa-miR-5694. PBK expression in KIRC, liver hepatocellular carcinoma, THCA, and thymoma was positively correlated with the infiltration of immune cells including B cells, CD4+T cells, CD8⁺ T cells, macrophages, monocytes, and neutrophils. The results of the functional enrichment analysis suggested that PBK and related genes contribute to tumor development via cell cycle regulation. We also identified 20 drugs that potentially inhibit PBK expression. Thus, PBK is associated with survival outcome in a variety of cancers and may promote tumor development and progression by increasing immune cell infiltration into the tumor microenvironment. These findings indicate that PBK is a potential therapeutic target and has prognostic value in cancer treatment.

MicroRNAs regulating SOX2 in cancer progression and therapy response

The proliferation, metastasis and therapy response of tumour cells are tightly regulated by interaction among various signalling networks. The microRNAs (miRNAs) can bind to 3'-UTR of mRNA and down-regulate expression of target gene. The miRNAs target various molecular pathways in regulating biological events such as apoptosis, differentiation, angiogenesis and migration. The aberrant expression of miRNAs occurs in cancers and they have both tumour-suppressor and tumour-promoting functions. On the contrary, SOX proteins are capable of binding to DNA and regulating gene expression. SOX2 is a well-known member of SOX family that its overexpression in different cancers to ensure progression and stemness. The present review focuses on modulatory impact of miRNAs on SOX2 in affecting growth, migration and therapy response of cancers. The lncRNAs and circRNAs can function as upstream mediators of miRNA/SOX2 axis in cancers. In addition, NF-κB, TNF-α and SOX17 are among other molecular pathways regulating miRNA/SOX2 axis in cancer. Noteworthy, anti-cancer compounds including bufalin and ovatodiolide are suggested to regulate miRNA/SOX2 axis in cancers. The translation of current findings to clinical course can pave the way to effective treatment of cancer patients and improve their prognosis.

MicroRNAs in prostate cancer following radiotherapy: Towards predicting response to radiation treatment

Prostate cancer (PCa) is the second most frequently diagnosed male cancer worldwide. Early diagnosis of PCa, response to therapy and prognosis still represent a challenge. Nearly 60% of PCa patients undergo radiation therapy (RT) which might cause side effects. In spite of numerous researches in this field, predictive biomarkers for radiation toxicity are still not elucidated. MicroRNAs as posttranscriptional regulators of gene expression are shown to be changed during and after irradiation. Manipulation with miRNA levels might be used to modulate response to RT-to reverse radioresistance-to induce radiosensitivity, or if needed, to reduce sensitivity to treatment to avoid side effects. In this review we have listed and described miRNAs involved in response to RT in PCa, and highlighted potential candidates for future biological tests predicting radiation response to RT, with the special focus on side effects of RT. Individual radiation response is a result of the interactions between physical characteristics of radiation treatment and biological background of each patient, and miRNA expression changes among others. According to described literature we concluded that let-7, miR-21, miR-34a, miR-146a, miR-155, and members of miR-17/92 cluster might be promising candidates for biological tests predicting radiosensitivity of PCa patients undergoing radiation treatment, and as future agents for modulation of radiation response. Predictive miRNA panels, especially for acute and late side effects of RT can serve as a starting point for decisions for individualized RT planning. We believe that this review might be one step closer to understanding molecular mechanisms underlying individual radiation response of patients with PCa.

Exploring the Mechanism of the miRNA-145/Paxillin Axis in Cell Metabolism During VEGF-A-Induced Corneal Angiogenesis

Purpose

Paxillin (PXN) is a key component of focal adhesions and plays an important role in angiogenesis. The aim of the present study was to investigate the effect of PXN in vascular endothelial growth factor A (VEGF-A)–induced angiogenesis in human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were transfected with PXN overexpression and PXN interference vectors. Biochemical detection was used to detect adenosine triphosphate and lactic acid production. The morphology of mitochondria was observed under an electron microscope, and flow cytometry was conducted to measure mitochondrial membrane potential. Transwell experiments were used to detect the migration and tube formation ability of each group of cells. The expression of hexokinase (HK)1, HK2, glucose transporter 1 (GLUT1), phosphorylated phosphatidylinositol 3-kinase (PI3K), phosphorylated AKT, and phosphorylated mechanistic target of rapamycin (mTOR) was evaluated by western blot.

Results

PXN silencing reduced the levels of lactic acid and adenosine triphosphate, downregulated HK1, HK2, and GLUT1, suppressed PI3K/AKT/mTOR signaling activation, and inhibited VEGF-A–induced mitochondria injury in VEGF-A–induced HUVECs. We also determined that miR-145-5p decreased the VEGF-A–induced expression of PXN and inhibited the invasion and angiogenesis of HUVECs. Also, miR-145-5p inhibition blocked the protective effect of PXN interference on VEGF-A–induced HUVEC injury. Furthermore, PXN interference significantly decreased lactic acid and adenosine triphosphate levels, inhibited PI3K/AKT/mTOR activation, and decreased the levels of HK1, HK2, and GLUT1 in VEGF-A-treated mouse corneal.

Conclusions

The results indicate that PXN silencing inhibited the VEGF-A–induced invasion and angiogenesis of HUVECs via regulation of cell metabolism and mitochondrial damage, suggesting that PXN may be a potential target for antiangiogenic therapies.

Identification of miRNA signatures and their therapeutic potentials in prostate cancer

BACKGROUND

Herein, we identified miRNA signatures that were able to differentiate malignant prostate cancer from benign prostate hyperplasia and revealed the therapeutic potential of these miRNAs against prostate cancer development.

METHODS AND RESULTS

MicroRNA expressions were determined by qPCR. MTT was used for cell viability analysis and immunohistochemistry was performed for Bax/Bcl-2 staining. ELISA was used to measure MMP2/9 levels. Wound healing assay was used for the evaluation of cell migration. Notably, expression levels of miR-125b-5p, miR-145-5p and miR-221-3p were significantly reduced in prostate cancer patients as compared to BPH patients. Moreover, ectopic expression of miR-125b-5p, miR-145-5p and miR-221-3p resulted in significant inhibition of cell proliferation and altered cell morphology. Also, expression level of Bax protein was increased while Bcl-2 level was reduced in cells treated with miR-125b-5p, miR-145-5p and miR-221-3p mimics. Enhanced expression of miR-125b-5p, miR-145-5p and miR-221-3p was also significantly altered the expression of caspase 3 and 8 levels. In addition, MMP9 levels were significantly reduced in cells ectopically expressing miR-221-3p. All miRNA mimics significantly interfered with the migration of prostate cancer cells.

CONCLUSIONS

Consequently, our findings point to an important role of these three miRNAs in prostate cancer and indicate that miR-125b-5p, miR-145-5p and miR-221-3p are potential therapeutic targets against prostate cancer.

MicroRNA miR-145-5p inhibits Phospholipase D 5 (PLD5) to downregulate cell proliferation and metastasis to mitigate prostate cancer

Prostate cancer (PCa), a frequently detected malignant tumor, is the fifth leading global cancer mortality cause in men. Although research has improved the PCa survival rate, significantly reduced survival occurs among patients at the metastatic stage. MiRNAs, which are short non-coding proteins, are crucial for several biological roles, essential for PCa proliferation, differentiation, multiplication, and migration. The investigation aimed to explore miR-145-5p and PLD5 association and clarify their function in regulating proliferation in PCa cell lines.The study used PC-3, LNCaP, DU-145 PCa, and RWPE-1 non-cancerous cell line, PCa, and BPH tissue specimens, and nude mice to validate results. MiR-145-5p and PLD5 manifestation were assessed through RT-qPCR. PLD5 and miR-145 binding was determined through dual-luciferase reporter gene assays. Validation of cell proliferation, migration, and invasion was assessed through MTT, scratch wound, and transwell assays, respectively.The results indicated a downregulation of miR-145-5p level in PCa cell lines and tissues in comparison to the non-cancerous controls. PLD5 overexpression exerted a cancerous effect while mimicking of miR-145-5p reversed the PLD5-oncogenic effects and significantly inhibited PCa cells proliferation, migration, invasion, and metastasis.In conclusion, the study revealed that miR-145-5p upregulated apoptosis and repressed migration, invasion, and metastasis of PCa via direct PLD5 modulation.

Using Network Distance Analysis to Predict lncRNA-miRNA Interactions

LncRNA-miRNA interactions contribute to the regulation of therapeutic targets and diagnostic biomarkers in multifarious human diseases. However, it remains difficult to experimentally identify lncRNA-miRNA associations at large scale, and computational prediction methods are limited. In this study, we developed a network distance analysis model for lncRNA-miRNA association prediction (NDALMA). Similarity networks for lncRNAs and miRNAs were calculated and integrated with Gaussian interaction profile (GIP) kernel similarity. Then, network distance analysis was applied to the integrated similarity networks, and final scores were obtained after confidence calculation and score conversion. Our model obtained satisfactory results in fivefold cross validation, achieving an AUC of 0.8810 and an AUPR of 0.8315. Moreover, NDALMA showed superior prediction performance over several other network algorithms, and we tested the suitability and flexibility of the model by comparing different types of similarity. In addition, case studies of the relationships between lncRNAs and miRNAs were conducted, which verified the reliability of our method in predicting lncRNA-miRNA associations. The datasets and source code used in this study are available at https://github.com/Liu-Lab-Lnu/NDALMA .

miR-145-5p as a predictive biomarker for breast cancer stemness by computational clinical investigation

BACKGROUND

Breast tumors enriched with breast cancer stem cells (BCSCs), play a crucial role in metastasis and tumor relapse. Hence, targeting BCSCs may lead to efficacious breast cancer therapy. BCSCs have a unique expression of stemness markers, including Nanog, POU5F1, SOX2, and CD44, which play a vital role in cancer stem cell properties. However, the regulation of microRNAs (miRNAs)-mediated cancer stem cell marker expressions is largely unclear.

METHODS

MIENTURNET was used to predict miRNA-target interactions. miR-TV, UALCAN and GEPIA databases were used to analyze the expression of miR-145-5p and SOX2. Survival analysis was obtained by cBioportal, KM plotter and Breast Cancer Gene-Expression Miner. RNAComposer was used to perform miRNA-mRNA duplex prediction. In vitro mRNA and miRNA analysis was performed by qRT-PCR.

RESULTS

It was observed that miR-145-5p was the common miRNA targeting stemness markers. miR-145-5p expression was found to be lower in breast cancer patients compared to healthy subjects. Based on survival analysis, low expression of miR-145-5p and high expression of SOX2 led to a poor overall survival rate in breast cancer patients. Pathway enrichment analysis indicated that SOX2 was highly enriched with transcription factors. Moreover, SOX2 expression level was also upregulated in axillary metastatic lymph nodules. Further, in vitro ectopic expression of miR-145-5p by its mimic downregulated the SOX2 expression compared to the control mimic. Overall, SOX2 was a direct target for miR-145-5p as per the binding and minimal-free energy.

CONCLUSIONS

In this study, miR-145-5p targeting SOX2 was identified as a potential predictive biomarker for breast cancer stemness.

MiR-145 suppresses the motility of prostate cancer cells by targeting cadherin-2

Metastasis is the main cause of poor prognosis in the advanced prostate cancer in clinic. Accumulating evidences have proposed that cell motility greatly contributes to the multiple steps of the metastatic process. MicroRNA-145 (miR-145) has been found to be downregulated in prostate cancer and serve as a putative tumor suppressor via decrease of cell growth and augmentation of cell death; however, the effects and the underlying mechanisms of miR-145 in prostate cancer cell motility have not been completely clarified. In the current study, we first demonstrated that miR-145 exerted inhibitory effects on the aggressive phenotype of the prostate cancer cells. Based on the bioinformatics analysis of the putative target genes of miR-145, we further experimentally identified a novel mechanism of miR-145 suppressing the aggressive phenotype of prostate cancer cells via directly targeting cadherin-2 (CDH2) protein translation. Re-expression of CDH2 could rescue miR-145-triggered cell migration and invasion defects. Our results suggested that miR-145 suppressed the motility of prostate cancer cells via post-transcriptional downregulation of CDH2 expression, and miR-145-CDH2 pair might serve as a potential target for intervention of prostate cancer metastasis.

Non-coding RNA in cancer

Majority of the human genome is transcribed to RNAs that do not encode proteins. These non-coding RNAs (ncRNAs) play crucial roles in regulating the initiation and progression of various cancers. Given the importance of the ncRNAs, the roles of ncRNAs in cancers have been reviewed elsewhere. Thus, in this review, we mainly focus on the recent studies of the function, regulatory mechanism and therapeutic potential of the ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA) and PIWI interacting RNA (piRNA), in different type of cancers.

miRNAs as Therapeutic Tools and Biomarkers for Prostate Cancer

Prostate cancer (PCa) is the fifth cause of tumor-related deaths in man worldwide. Despite the considerable improvement in the clinical management of PCa, several limitations emerged both in the screening for early diagnosis and in the medical treatment. The use of prostate-specific antigen (PSA)-based screening resulted in patients’ overtreatment and the standard therapy of patients suffering from locally advanced/metastatic tumors (e.g., radical prostatectomy, radiotherapy, and androgen deprivation therapy) showed time-limited efficacy with patients undergoing progression toward the lethal metastatic castration-resistant PCa (mCRPC). Although valuable alternative therapeutic options have been recently proposed (e.g., docetaxel, cabazitaxel, abiraterone, enzalutamide, and sipuleucel-T), mCRPC remains incurable. Based on this background, there is an urgent need to identify new and more accurate prostate-specific biomarkers for PCa diagnosis and prognosis and to develop innovative medical approaches to counteract mCRPC. In this context, microRNA (miRNAs) emerged as potential biomarkers in prostate tissues and biological fluids and appeared to be promising therapeutic targets/tools for cancer therapy. Here we overview the recent literature and summarize the achievements of using miRNAs as biomarkers and therapeutic targets/tools for fighting PCa.

MicroRNA-145 transcriptionally regulates Semaphorin 3A expression in prostate cancer cells

Prostate cancer (PCa) is one of the most prevalent cancer types among males. Differential expression of microRNAs is associated with various cancers including PCa. Although mature microRNAs are preferentially located in the cytoplasm, several studies identified mature human microRNAs in purified nuclei and miR-145 has been found to be predominantly expressed in the nuclei of benign tissues compared to tumor lesions. However, the nuclear functions of miR-145 are yet limited. Here, we aimed at investigating the inductive role of miR-145 on the expression of Semaphorin 3A (SEMA3A) in PCa cell lines. To study the regulatory potential of miR-145 in the transcriptional level in PCa, we overexpressed miR-145 in PC3 and DU145 cells, and confirmed its upregulation by quantitative-real-time-PCR. Then we investigated the tumor suppressor potential of miR-145 upon inducing SEMA3A expression using cell viability assay, western blot analysis, Chromatin Immunoprecipitation assay and luciferase reporter assay. Our results revealed that p53, miR-145, and SEMA3A expressions are significantly downregulated in PC3 and DU145 cells compared to nontumorigenic prostate epithelial PNT1a cells. miR-145 overexpression in PCa cells induced the expression of SEMA3A at both messenger RNA and protein levels. Furthermore, increased miR-145 expression enriched RNA Pol-II antibody on the promoter of SEMA3A and induced luciferase activity controlled by SEMA3A promoter. In this study, we showed that the functions of miR-145 are not limited to gene silencing, and found that it may lead to changes in gene expression in the transcriptional level.

Modular Peptide Probe for Pre/Intra/Postoperative Therapeutic to Reduce Recurrence in Ovarian Cancer

Even with optimal surgery, 80% of patients with ovarian cancer will have recurrence. Adjuvant therapy can reduce the recurrence of tumors; however, the therapeutic effect is still not prominent. Herein, we designed a modular peptide probe (T_CDTMP), which can be self-assembled into nanoparticles (NPs) by loading in miR-145-5p or VEGF-siRNA. In vivo, (1) preoperative administration of T_CDTMP/miR-145-5p ensured that NPs were adequately accumulated in tumors through active targeting and increased the expression of miR-145-5p in tumors, thereby inducing tumor cell apoptosis. (2) Intraoperatively, most of the tumors were removed, while the microscopic residual tumors were largely eliminated by T_CDTMP/miR-145-5p-mediated photodynamic therapy (PDT). (3) Postoperatively, T_CDTMP/VEGF-siRNA were given for antiangiogenesis therapy, thus delaying the recurrence of tumors. This treatment was named a preoperative (T_CDTMP/miR-145-5p)||intraoperative (surgery and PDT)||postoperative (T_CDTMP/VEGF-siRNA) therapeutic system and abbreviated as the PIP therapeutic system, which reduced the recurrence of ovarian cancer in subcutaneous tumor models, intraperitoneal metastasis models, and patient-derived tumor xenograft models. Our findings provide a therapeutic system based on modular peptide probes to reduce the recurrence of ovarian cancer after surgery, which provides a perspective for the surgical management of ovarian cancer.

MiR-145-5p suppresses the proliferation, migration and invasion of gastric cancer epithelial cells via the ANGPT2/NOD_LIKE_RECEPTOR axis

Objective

This study aimed to investigate the relationship among miR-145-5p, ANGPT2 and the NOD_LIKE_RECEPTOR pathway, thereby revealing the molecular mechanism of these three factors underlying the proliferation, migration and invasion of gastric cancer (GC) epithelial cells.

Methods

qRT-PCR was carried out to detect the expression of miR-145-5p and ANGPT2 mRNA. Western blot was performed to test the protein levels of ANGPT2 as well as NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway. The targeting relationship between miR-145-5p and ANGPT2 was verified via a dual-luciferase reporter gene assay. The proliferation, migration and invasion of GC cells were detected through MTT and Transwell assays, respectively.

Results

The expression of miR-145-5p was significantly down-regulated in GC cells, while that of ANGPT2 was notably up-regulated. MiR-145-5p directly bound with the 3′-UTR of ANGPT2 mRNA, thereby targeting ANGPT2 after transcription. Overexpression of miR-145-5p inhibited the proliferation, migration and invasion of GC cells by suppressing ANGPT2. Moreover, low expression of ANGPT2 affected the protein levels of NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway, thus weakening the abilities of cell proliferation, migration and invasion.

Conclusions

MiR-145-5p plays an important role in GC epithelial cells, and it can affect cell proliferation, migration and invasion of GC cells by targeting ANGPT2 and regulating the NOD_LIKE_RECEPTOR pathway. Overall, our study further elucidates the molecular mechanism underlying the malignant progression of GC.

Integrated Analysis of Three Publicly Available Gene Expression Profiles Identified Genes and Pathways Associated with Clear Cell Renal Cell Carcinoma

BACKGROUND Although advances have been achieved in the therapy of clear cell renal cell carcinoma (ccRCC), the pathogenesis of ccRCC is not yet fully understood. This study aimed to explore the critical genes and pathways associated with ccRCC by meta-analysis. MATERIAL AND METHODS We performed an integrated analysis of 3 publicly available microarray datasets developed from ccRCC tumor samples and normal tissues. A list of overlapped differentially expressed genes (DEGs) with the consistent expression trend in ccRCC tumor samples were identified, for which the protein-protein interaction (PPI) network was constructed, followed by topology structure and module analysis. The microRNA (miRNA) regulatory network and ccRCC associated pathway network were reconstructed. RESULTS A total of 504 genes were found to be consistently and differentially regulated based on 3 microarray datasets. The overrepresented pathways for DEGs included citric acid cycle (TCA cycle) and peroxisome proliferator-activated receptor (PPAR) signaling pathway and cell cycle. The PPI network was clustered into 6 modules that were closely related with the M phase, desmosome assembly, and response to hormone stimulus. The hsa04110: cell cycle and hsa04510: focal adhesion were the significant pathways associated with ccRCC overlapped with enrichment analysis. KDR and ITGB4 were focal-adhesion-associated genes, which were regulated by has-miR-424 and has-miR-204, respectively. CCND2 and CCNA2 were cell-cycle-associated genes, which were regulated by hsa-miR-324-3p, hsa-miR-146a and hsa-miR-145. CONCLUSIONS Cell cycle and focal adhesion were dysregulated in ccRCC, which were associated with the expression of CCND2, ITGB4, KDR, and CCNA2 genes. The deregulation of pathways and associated genes may provide insights to ccRCC research and therapy.

Coordinated AR and microRNA regulation in prostate cancer

The androgen receptor (AR) remains a key driver of prostate cancer (PCa) progression, even in the advanced castrate-resistant stage, where testicular androgens are absent. It is therefore of critical importance to understand the molecular mechanisms governing its activity and regulation during prostate tumourigenesis. MicroRNAs (miRs) are small ∼22 nt non-coding RNAs that regulate target gene, often through association with 3′ untranslated regions (3′UTRs) of transcripts. They display dysregulation during cancer progression, can function as oncogenes or tumour suppressors, and are increasingly recognised as targets or regulators of hormonal action. Thus, understanding factors which modulate miRs synthesis is essential. There is increasing evidence for complex and dynamic bi-directional cross-talk between the multi-step miR biogenesis cascade and the AR signalling axis in PCa. This review summarises the wealth of mechanisms by which miRs are regulated by AR, and conversely, how miRs impact AR's transcriptional activity, including that of AR splice variants. In addition, we assess the implications of the convergence of these pathways on the clinical employment of miRs as PCa biomarkers and therapeutic targets.

Silence of FOXD2-AS1 inhibited the proliferation and invasion of esophagus cells by regulating miR-145-5p/CDK6 axis

This study aimed to investigate the function of long non-coding RNA FOXD2 adjacent opposite strand RNA 1 (lncRNA FOXD2-AS1) during the progression of esophagus cancer (EC) and explore its underlying molecular mechanisms. The level of FOXD2-AS1 in EC tissues and paracancerous tissues was detected by using RT-qPCR; ROC curve was used to evaluate the diagnostic value of FOXD2-AS1 for EC. In addition, CCK8 assay and immunofluorescence staining assay were used to detect the proliferation of Eca-109 and TE-1 cells. To investigate the function of FOXD2-AS1 on cell apoptosis and cell cycle, flow cytometry was performed. To detect the invasion ability of EC cells, transwell invasion assay was performed. Starbase3.0 and Targetscan were used to predict the target genes of FOXD2-AS1 and miR-145-5p, and protein expressions were detected with western blot. We found FOXD2-AS1 was significantly upregulated in EC tissues compared with adjacent normal tissues, which was positively correlated with clinicopathological parameters of patients with EC. Downregulation of FOXD2-AS1 inhibited the proliferation and invasion by inducing apoptosis of EC cells. Moreover, FOXD2-AS1 may regulate the expression of CDK6 by targeting miR-145-3p. Meanwhile, silencing of FOXD2-AS1 caused G1 phase arrest of EC cells by reducing the expression of CDK6. In conclusion, silening FOXD2-AS1 significantly inhibited the proliferation and invasion of EC cells by regulating the miR-145-5p/CDK6 axis. Therefore, FOXD2-AS1 might be used as diagnostic biomarker and therapeutic target for EC.

The regulatory pathways leading to stem-like cells underlie prostate cancer progression

Prostate cancer (PCa) is the most common cause of malignancy in males and the third leading cause of cancer mortality in the United States. The standard care for primary PCa with local invasive disease mainly is surgery and radiation. For patients with distant metastases, androgen deprivation therapy (ADT) is a gold standard. Regardless of a favorable outcome of ADT, patients inevitably relapse to an end-stage castration-resistant prostate cancer (CRPC) leading to mortality. Therefore, revealing the mechanism and identifying cellular components driving aggressive PCa is critical for prognosis and therapeutic intervention. Cancer stem cell (CSC) phenotypes characterized as poor differentiation, cancer initiation with self-renewal capabilities, and therapeutic resistance are proposed to contribute to the onset of CRPC. In this review, we discuss the role of CSC in CRPC with the evidence of CSC phenotypes and the possible underlying mechanisms.

Circular RNAs and their participation in stemness of cancer

Circular RNAs (circRNA) are covalently closed single-stranded RNA molecules that act as important regulators of gene expression through different mechanisms. Meanwhile, cancer stem cells (CSCs) are a small subpopulation of cells, with properties similar to normal stem cells that arise during the development of cancer and support tumor growth, induce resistance to therapy, and are responsible for metastatic spread. Since the elimination of CSCs is an important goal of cancer treatment, the circRNAs that participate in regulating gene expression and signaling pathways linked to CSCs have aroused attention in recent years, especially because it has been suggested that these molecules may function as therapeutic targets and/or clinical biomarkers. Thus, the proposal of this work is to enumerate a series of circRNAs that have been shown to play a relevant role in CSCs and explain in detail the molecular regulatory mechanisms that they establish to perform that function.

The interplay between m6A RNA methylation and noncoding RNA in cancer

N6-methyladenosine (m6A) methylation, one of the most common RNA modifications, has been reported to execute important functions that affect normal life activities and diseases. Most studies have suggested that m6A modification can affect the complexity of cancer progression by regulating biological functions related to cancer. M6A modification of noncoding RNAs regulates the cleavage, transport, stability, and degradation of noncoding RNAs themselves. It also regulates cell proliferation and metastasis, stem cell differentiation, and homeostasis in cancer by affecting the biological function of cells. Interestingly, noncoding RNAs also play significant roles in regulating these m6A modifications. Additionally, it is becoming increasingly clear that m6A and noncoding RNAs potentially contribute to the clinical application of cancer treatment. In this review, we summarize the effect of the interactions between m6A modifications and noncoding RNAs on the biological functions involved in cancer progression. In particular, we discuss the role of m6A and noncoding RNAs as possible potential biomarkers and therapeutic targets in the treatment of cancers.

MicroRNA Changes in Firefighters

Objectives:

Firefighters have elevated cancer incidence and mortality rates. MicroRNAs play prominent roles in carcinogenesis, but have not been previously evaluated in firefighters.

Methods:

Blood from 52 incumbent and 45 new recruit nonsmoking firefighters was analyzed for microRNA expression, and the results adjusted for age, obesity, ethnicity, and multiple comparisons.

Results:

Nine microRNAs were identified with at least a 1.5-fold significant difference between groups. All six microRNAs with decreased expression in incumbent firefighters have been reported to have tumor suppressor activity or are associated with cancer survival, and two of the three microRNAs with increased expression in incumbent firefighters have activities consistent with cancer promotion, with the remaining microRNA associated with neurological disease.

Conclusion:

Incumbent firefighters showed differential microRNA expression compared with new recruits, providing potential mechanisms for increased cancer risk in firefighters.

Enhancement of therapeutic potential of mesenchymal stem cell-derived extracellular vesicles

After the initial investigations into applications of mesenchymal stem cells (MSCs) for cell therapy, there was increased interest in their secreted soluble factors. Following studies of MSCs and their secreted factors, extracellular vesicles (EVs) released from MSCs have emerged as a new mode of intercellular crosstalk. MSC-derived EVs have been identified as essential signaling mediators under both physiological and pathological conditions, and they appear to be responsible for many of the therapeutic effects of MSCs. In several in vitro and in vivo models, EVs have been observed to have supportive functions in modulating the immune system, mainly mediated by EV-associated proteins and nucleic acids. Moreover, stimulation of MSCs with biophysical or biochemical cues, including EVs from other cells, has been shown to influence the contents and biological activities of subsequent MSC-derived EVs. This review provides on overview of the contents of MSC-derived EVs in terms of their supportive effects, and it provides different perspectives on the manipulation of MSCs to improve the secretion of EVs and subsequent EV-mediated activities. In this review, we discuss the possibilities for manipulating MSCs for EV-based cell therapy and for using EVs to affect the expression of elements of interest in MSCs. In this way, we provide a clear perspective on the state of the art of EVs in cell therapy focusing on MSCs, and we raise pertinent questions and suggestions for knowledge gaps to be filled.

Downregulation of miR-145-5p elevates retinal ganglion cell survival to delay diabetic retinopathy progress by targeting FGF5

Diabetic retinopathy (DR) is a leading cause of new-onset blindness. Recent studies showed that protecting retinal ganglion cells (RGCs) from high glucose-induced injury is a promising strategy for delaying DR. This study is to investigate the role of miR-145-5p in high glucose-induced RGC injury. Here, RGCs were randomly divided into low glucose and high glucose groups. PCR assay showed miR-145-5p was significantly upregulated in high glucose group. Transfection of miR-145-5p inhibitor decreased pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) levels, elevated cell viability and proliferation, as well as suppressed cell apoptosis by ELISA, MTT, EdU proliferation, colony formation and flow cytometry assays, respectively. Moreover, dual-luciferase reporter assay confirmed FGF5 as a target gene of miR-145-5p. FGF5 knockdown could partially reverse the protective effects of miR-145-5p on RGC-5 cells. In conclusion, our results demonstrated that inhibition of miR-145-5p might be a neuroprotective target for diabetes mellitus-related DR.

Abbreviations: DR: diabetic retinopathy; RGCs: retinal ganglion cells; miR-145-5p: microRNA-145-5p; TNF-α: tumor necrosis factor-α; IL-6: interleukin-6; FGF: fibroblast growth factor; ATCC: American Type Culture Collection; WT: wild type; MUT: mutant type

ANLN-induced EZH2 upregulation promotes pancreatic cancer progression by mediating miR-218-5p/LASP1 signaling axis

Background

Pancreatic cancer is a highly lethal malignancy with poor prognosis. Anillin (ANLN), an actin binding protein, is upregulated and plays an important role in many malignant tumors. However, the precise role of ANLN in pancreatic cancer remains unclear.

Methods

The expression of ANLN and its association with pancreatic cancer patient survival were analyzed using an online database and confirmed by immunohistochemistry. The ANLN protein expression in pancreatic cancer cell lines was detected by Western blot. Cell proliferation, colony formation and transwell assays in vitro and in vivo tumor growth were used to determine the role of ANLN in pancreatic cancer. Gene expression microarray analysis and a series of in vitro assays were used to elucidate the mechanisms of ANLN regulating pancreatic cancer progression.

Results

We found that the ANLN expression was significantly upregulated in pancreatic cancer tissues and cell lines. The high expression of ANLN was associated with tumor size, tumor differentiation, TNM stage, lymph node metastasis, distant metastasis and poor prognosis in pancreatic cancer. ANLN downregulation significantly inhibited cell proliferation, colony formation, migration, invasion and tumorigenicity in nude mice. Meanwhile, we found that ANLN knockdown inhibited several cell-cell adhesion related genes, including the gene encoding LIM and SH3 protein 1 (LASP1). LASP1 upregulation partially reversed the tumor-suppressive effect of ANLN downregulation on pancreatic cancer cell progression. Moreover, we found that ANLN downregulation induced the expression of miR-218-5p which inhibited LASP1 expression through binding to its 3’UTR. We also found that ANLN-induced enhancer of zeste homolog 2 (EZH2) upregulation was involved in regulating miR-218-5p/LASP1 signaling axis. EZH2 upregulation or miR-218-5p downregulation partially reversed the tumor-suppressive effect of ANLN downregulation on pancreatic cancer cell progression.

Conclusion

ANLN contributed to pancreatic cancer progression by regulating EZH2/miR-218-5p/LASP1 signaling axis. These findings suggest that ANLN may be a candidate therapeutic target in pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1340-7) contains supplementary material, which is available to authorized users.

Long non-coding RNAs in Oral squamous cell carcinoma: biologic function, mechanisms and clinical implications

There is growing evidence that regions of the genome that cannot encode proteins play an important role in diseases. These regions are usually transcribed into long non-coding RNAs (lncRNAs). LncRNAs, little or no coding potential, are defined as capped transcripts longer than 200 nucleotides. New sequencing technologies have shown that a large number of aberrantly expressed lncRNAs are associated with multiple cancer types and indicated they have emerged as an important class of pervasive genes during the development and progression of cancer. However, the underlying mechanism in cancer is still unknown. Therefore, it is necessary to elucidate the lncRNA function. Notably, many lncRNAs dysregulation are associated with Oral squamous cell carcinoma (OSCC) and affect various aspects of cellular homeostasis, including proliferation, survival, migration or genomic stability. This review expounds the up- or down-regulation of lncRNAs in OSCC and the molecular mechanisms by which lncRNAs perform their function in the malignant cell. Finally, the potential of lncRNAs as non-invasive biomarkers for OSCC diagnosis are also described. LncRNAs hold promise as prospective novel therapeutic targets, but more research is needed to gain a better understanding of their biologic function.

The targeting of MTDH by miR‑145‑5p or miR‑145‑3p is associated with prognosis and regulates the growth and metastasis of prostate cancer cells

Studies have rarely been conducted on the role of miRNAs in prostate cancer (PCa) cell progression by directly targeting MTDH, at least to the best of our knowledge. Thus, the present study aimed to identify miRNAs closely related with metadherin (MTDH) and to determine their roles in PCa. For this purpose, the expression levels of MTDH in PCa tissues and cell lines were examined by RT‑qPCR, immunohistochemistry and western blot analysis. By cell transfection, MTDH was either overexpressed in the normal prostate epithelial cell lines or silenced in tumor cell lines to determine cell viability, invasion and migration. Bioinformatics analysis, RT‑qPCR, western blot analysis, dual‑luciferase reporter assay and MTT assay were performed to identify direct the target of MTDH and to examine tumor cell viability. Rescue experiments using the PC‑3 and LNCaP cells were carried out by MTT assay, scratch wound assay, Transwell assay, RT‑qPCR and western blot analysis. Experiments were also conducted using 46 PCa human cancer and adjacent tissues, as wells as on 501 cases of PCa from the TCGA database. It was confirmed that the overexpression of MTDH was associated with a poor prognosis of patients. The overexpression of MTDH was found to promote the viability, invasion and migration of PCa cells. miR‑145‑5p and miR‑145‑3p identified from 16 miRNAs were found to be closely related to PCa and to be the targets of MTDH. Both these miRNAs were found to significantly suppress the growth and metastasis of PCa cells by negatively regulating the expression of MTDH. On the whole, the findings of this study demonstrate that MTDH functions as an oncogene in PCa and the inhibition of MTDH by miR‑145‑5p or miR‑145‑3p suppressed the growth and metastasis of PCa cells. The miR‑145‑5p/MTDH and miR‑145‑3p/MTDH pathways may thus become novel treatment targets for PCa.

LncRNA BRE-AS1 interacts with miR-145-5p to regulate cancer cell proliferation and apoptosis in prostate carcinoma and has early diagnostic values

Long non-coding RNA (LncRNA) BRE-AS1 has recently proven to be a tumor suppressor in lung cancer. The present study aimed to investigate the involvement of lncRNA BRE-AS1 in prostate carcinoma (PC). In the present study we found that plasma BRE-AS1 and miR-145-5p were both down-regulated in PC patients than in healthy controls. Down-regulation of BRE-AS1 and miR-145-5p effectively distinguished early-stage PC patients from healthy controls. A significant and positive correlation between BRE-AS1 and miR-145-5p was only found in PC patients. BRE-AS1 overexpression mediated miR-145-5p up-regulation in PC cells, while miR-145-5p overexpression did not significantly affect BRE-AS1. Overexpression of BRE-AS1 and miR-145-5p led to inhibited proliferation and promoted apoptosis of PC cells. miR-145-5p inhibitor attenuated the effects of BRE-AS1 overexpression on cancer cell behaviors. Therefore, lncRNA BRE-AS1 may regulate cancer cell proliferation and apoptosis in PC by interacting with miR-145-5p.

AKT drives SOX2 overexpression and cancer cell stemness in esophageal cancer by protecting SOX2 from UBR5-mediated degradation

As a transcription factor critical for embryonic and adult stem cell self-renewal and function, SOX2 gene amplification has been recognized as a driving factor for various cancers including esophageal cancer. SOX2 overexpression occurs more broadly in cancer than gene amplification, but the mechanism is poorly understood. Here we showed that in esophageal cancer cell lines the levels of SOX2 proteins are not directly correlated to the copy numbers of SOX2 genes and are strongly influenced by proteostasis. We showed that AKT is a major determinant for SOX2 overexpression and does so by protecting SOX2 from ubiquitin-dependent protein degradation. We identified UBR5 as a major ubiquitin E3 ligase that induces SOX2 degradation through ubiquitinating SOX2 at lysine 115. Phosphorylation of SOX2 at threonine 116 by AKT inhibits the interaction of UBR5 with SOX2 and thus stabilizes SOX2. We provided evidence that AKT inhibitor can effectively downregulate SOX2 and suppress esopheageal cancer cell proliferation and stemness. Taken together, our study provides new insight into the mechanism of SOX2 overexpression in cancer and evidence for targeting AKT as a potential therapeutic strategy for SOX2-positive cancers.

MicroRNAs as prognostic markers in prostate cancer

BACKGROUND

Prostate cancer (PCa) is the most commonly diagnosed malignancy in men who are especially over the age of 50 years in the western countries. Currently used therapeutic modalities mostly fail to give positive clinical outcomes and nearly 30% of the PCa patients eventually develop clinical recurrence. Therefore, understanding the underlying mechanisms of PCa progression is of paramount importance to help determining the course of disease. In this study, we aimed at profiling the differentially expressed microRNAs in recurrent PCa samples.

METHODS

We profiled the microRNA expression of 20 recurrent and 20 non-recurrent PCa patients with microRNA microarray, and validated the differential expression of significantly deregulated microRNAs in 40 recurrent and 39 non-recurrent PCa specimens using quantitative reverse-transcription PCR (qRT-PCR). Data were statistically analyzed using two-sided Student's t-test, Pearson Correlation test, Receiver operating characteristic (ROC) analysis.

RESULTS

Our results demonstrated that a total of 682 probes were significantly deregulated in recurrent versus non-recurrent PCa specimen comparison. Among those, we confirmed the significant downregulation of miR-424 and upregulation of miR-572 with further qRT-PCR analysis in a larger sample set. Further ROC analysis showed that these microRNAs have enough power to distinguish recurrent specimens from non-recurrent ones on their own.

CONCLUSIONS

Here, we report that differential expression of miR-424 and miR-572 in recurrent PCa specimens can serve as novel biomarkers for prediction of PCa progression.

miR-145-5p Suppresses Breast Cancer Progression by Inhibiting SOX2

BACKGROUND

In this study, we aimed to investigate the expression and clinical significance of miR-145-5p and its tumor-suppressive effect in breast cancer patients.

METHODS

We used luciferase reporter assay, real-time quantitative reverse transcription polymerase chain reaction and Western blot to identify sex-determining region Y-box2 (SOX2) as the target gene of miR-145-5p. Their expression levels in breast cancer tissues (n = 122) were detected by real-time quantitative polymerase chain reaction. We also applied 3-(4,5-dimethyl- 2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry to reveal the effect of miR-145-5p on proliferation in breast cancer.

RESULTS

miR-145-5p expression is downregulated in breast cancer tissues and negatively correlated with SOX2 expression. Decreased miR-145-5p expression was significantly associated with larger tumor size, distal metastasis, higher Ki67 expression level, and shorter overall survival. miR-145-5p inhibits breast cancer cell proliferation via targeting SOX2, and multivariate regression showed that both miR-145-5p and SOX2 were unfavorable prognostic factors.

CONCLUSIONS

miR-145-5p played a suppressive role in the proliferation of breast cancer cells by targeting SOX2, and miR-145-5p is a putative biomarker for risk assessment in patients with breast cancer.

MiR-192, miR-200c and miR-17 are fibroblast-mediated inhibitors of colorectal cancer invasion

Colorectal cancer remains a leading cause of cancer-related death worldwide. A previous transcriptomics based study characterized molecular subgroups of which the stromal subgroup was associated with the worst clinical outcome. Micro-RNAs (miRNAs) are well-known regulators of gene expression and can follow a non-linear repression mechanism. We set up a model combining piecewise linear and linear regression and applied this combined regression model to a comprehensive colon adenocarcinoma dataset. We identified miRNAs involved in regulating characteristic gene sets, particularly extracellular matrix remodeling in the stromal subgroup. Comparison of expression data from separated (epithelial) cancer cells and stroma cells or fibroblasts associate these regulatory interactions with infiltrating stromal or tumor-associated fibroblasts. MiR-200c, miR-17 and miR-192 were identified as the most promising candidates regulating genes crucial for extracellular matrix remodeling. We validated our computational findings by in vitro assays. Enforced expression of either miR-200c, miR-17 or miR-192 in untransformed human colon fibroblasts down-regulated 85% of all predicted target genes. Expressing these miRNAs singly or in combination in human colon fibroblasts co-cultured with colon cancer cells considerably reduced cancer cell invasion validating these miRNAs as cancer cell infiltration suppressors in tumor associated fibroblasts.

Downregulation of miR-145-5p in cancer cells and their derived exosomes may contribute to the development of ovarian cancer by targeting CT

The present study aimed to identify shared microRNAs (miRNAs) in ovarian cancer (OC) cells and their exosomes using microarray data (accession number GSE103708) available from the Gene Expression Omnibus database, including exosomal samples from 13 OC cell lines and 3 normal ovarian surface epithelial cell lines, and their original cell samples. Differentially expressed miRNAs (DE‑miRNAs) were identified using the Linear Models for Microarray data method, and mRNA targets of DE‑miRNAs were predicted using the miRWalk2 database. The potential functions of target genes were analyzed using Database for Annotation, Visualization and Integrated Discovery and intersected with known OC‑associated pathways downloaded from the Comparative Toxicogenomics Database. The associations between crucial miRNAs and target genes, and their clinical associations, were validated using data from The Cancer Genome Atlas. As a result, 16 upregulated and 6 downregulated DE‑miRNAs were shared in OC cell lines and their exosomes compared with normal controls. The target genes of 11 common DE‑miRNAs were predicted. Among these DE‑miRNAs, a low expression of homo sapiens (hsa)‑miR‑145‑5p was significantly correlated with a poor prognosis and higher stages. Although 91 target genes were predicted for hsa‑miR‑145‑5p, only 4 genes [connective tissue growth factor (CTGF), myotubularin‑related protein 14, protein phosphatase 3 catalytic subunit alpha and suppressor of cytokine signaling 7] were suggested as risk factors for prognosis. The subsequent Pearson's correlation analysis validated a significant negative correlation between hsa‑miR‑145‑5p and CTGF (r=‑0.1126, P=0.02188). According to the results of the functional analysis, CTGF is involved in the Hippo signaling pathway (hsa04390). In conclusion, decreased expression of hsa‑miR‑145 in OC and OC‑derived exosomes may be a crucial biomarker for the diagnosis and treatment of OC.

miR-145-5p Inhibits Vascular Smooth Muscle Cells (VSMCs) Proliferation and Migration by Dysregulating the Transforming Growth Factor-b Signaling Cascade

Background

There is accumulating evidence demonstrating that microRNAs (miRNA) play essential roles in proliferation, migration, and invasion of vascular smooth muscle cells (VSMCs). However, the exact function of these molecules and the mechanisms involved are not fully understood. In this study, we defined the role of miR-145-5p in VSMCs.

Material/Methods

This study used the PDGF-bb-induced VSMCs proliferation model. Expression of miR-145-5p and its target, Smad4, were detected and measured by real-time PCR and Western blot analysis. The luciferase reporter of miR-145-5p was used to elucidate miRNA-target interactions. The functions of miR-145-5p in proliferation and migration were detected by CCK-8 assay, Transwell assay, and scratch test.

Results

This study demonstrates that miR-145-5p is downregulated in PDGF-mediated VSMCs in both time- and dose-dependent manners. The in vitro results suggest that overexpression of miR-145-5p results in a reduction in SMAD4 and an increase in SMAD2, Smad3, and TGF-β at the mRNA and protein levels. Overexpression of miR-145-5p inhibited PDGF-induced VSMCs proliferation and migration. Moreover, SMAD4 was identified as a direct target of miR-145-5p and is involved in PDGF-mediated VSMC proliferation. Downstream factors such as Smad2, Smad3, and TGF-β were also influenced by miR-145-5p.

Conclusions

We identify miR-145-5p as a novel regulator of VSMC. Moreover, miR-145-5p inhibits VSMCs proliferation and migration by directly targeting Smad4 and dysregulating the transforming growth factor-β signaling cascade, including Smad2, Smad3, and TGF-β.

miR‑145‑5p reduces proliferation and migration of hepatocellular carcinoma by targeting KLF5

MicroRNAs (miRs) are important in hepatocellular carcinoma (HCC) progression. miR‑145‑5p acts as a tumor suppressor in certain malignancies, however, its role in HCC remains unclear. The present study aimed to perform a functional analysis of miR‑145‑5p in HCC in order to elucidate its role in the pathogenesis of HCC. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to analyze tissue and cellular expression of miR‑145‑5p in HCC. Following miRNA mimics transfection, cell viability, apoptosis and cells migration were determined by Cell Counting kit‑8, Annexin V‑FITC/propidium iodide staining and Transwell analyses. The target of miR‑145‑5p was analyzed by luciferase reporter assay and western blot analysis. It was observed that miR‑145‑5p was significantly decreased in HCC tissues and cell lines. Overexpression of miR‑145‑5p significantly increased apoptosis, reduced cell proliferation and suppressed HCC cell migration. Kruppel‑like factor 5 (KLF5) is regarded as a target of miR‑145‑5p in HCC cells. In addition, KLF5 overexpression partially attenuated the tumor suppressive effects of miR‑145‑5p. KLF5 expression was negatively associated with levels of miR‑145‑5p in HCC tissues. The present study demonstrated that miRNA‑145‑5p may, by targeting KLF5, partially suppress HCC cell growth and motility. The results of the present study suggested that miRNA‑145‑5p alteration in HCC may serve a role in the progression of HCC.

Novel circular RNA expression profiles reflect progression of patients with hypopharyngeal squamous cell carcinoma

Circular RNAs (circRNAs), a novel class of endogenous noncoding RNAs, have been shown to have important roles in a number of diseases, including several types of cancers. We hypothesized that circRNAs are involved in the pathogenesis of hypopharyngeal squamous cell carcinoma (HSCC). To test our hypothesis, we initially compared the expression profiles of circRNAs in 4 paired HSCC and adjacent normal tissue samples by using a circRNA microarray. The microarray data showed that 2392 circRNAs, including 1304 upregulated and 1088 downregulated circRNA transcripts, were significantly dysregulated in the HSCC tissues. The 10 most dysregulated circRNAs from the microarray analysis were further validated in another 32 pairs of specimens using quantitative real-time polymerase chain reaction assays. These circRNAs might sponge microRNAs (miRNAs) in predicted circRNA-miRNA-mRNA networks. Bioinformatics analysis was also performed to predict possible pathways in which these networks might be involved. Finally, we analyzed the interaction between validated circRNAs and their potential cancer-related miRNA targets. We are the first to comprehensively delineate the expression profiles of circRNAs in HSCC and to provide potential candidates for future mechanism studies. Our study is potentially of critical significance in uncovering the roles of circRNAs in HSCC.

Expression of miR-145 and Its Target Proteins Are Regulated by miR-29b in Differentiated Neurons

MicroRNAs (miRNAs) are emerging as the most potential regulator of neuronal development. Recent studies from our lab and elsewhere have demonstrated a direct role of miRNAs in regulating neuronal differentiation and synaptogenesis. MicroRNA-145, a miRNA identified to regulate pluripotency of stem cells, downregulates the protein levels of reprogramming transcription factors (RTFs) like OCT4, SOX2, and KLF4 (cell, 137,647-658,2009). Studies have shown that miR-145 is multifunctional and crucial for fate determination of neurons. In our recently published study, we have identified a set of miRNAs including miR-145 and miR-29b families differentially expressed in SH-SY5Y cells exposed sequentially with retinoic acid + brain-derived neurotrophic factor (RA+BDNF) for differentiation into mature neurons (Mol Neurobiol (2016) doi: https://doi.org/10.1007/s12035-016-0042-9 ). In the present study, we have identified the role of miR-29b in upregulation of miR-145, which is upregulated after exposure of RA+BDNF in a P53-dependent manner. In differentiating SH-SY5Y cells, expression of miR-29b downregulates expression of P85α, a P53 inhibitor, which results in upregulation of miR-145 and downregulation of RTF proteins. Ectopic expression of miR-145 and miR-29b in amounts equivalent to their endogenous expression has induced G1 phase cell cycle arrest. In conclusion, our studies have identified miR-29b as an upstream regulator of miR-145 and targets its RTF genes during differentiation of SH-SY5Y cells.

The dark side of SOX2: cancer - a comprehensive overview

The pluripotency-associated transcription factor SOX2 is essential during mammalian embryogenesis and later in life, but SOX2 expression can also be highly detrimental. Over the past 10 years, SOX2 has been shown to be expressed in at least 25 different cancers. This review provides a comprehensive overview of the roles of SOX2 in cancer and focuses on two broad topics. The first delves into the expression and function of SOX2 in cancer focusing on the connection between SOX2 levels and tumor grade as well as patient survival. As part of this discussion, we address the developing connection between SOX2 expression and tumor drug resistance. We also call attention to an under-appreciated property of SOX2, its levels in actively proliferating tumor cells appear to be optimized to maximize tumor growth - too little or too much SOX2 dramatically alters tumor growth. The second topic of this review focuses on the exquisite array of molecular mechanisms that control the expression and transcriptional activity of SOX2. In addition to its complex regulation at the transcriptional level, SOX2 expression and activity are controlled carefully by microRNAs, long non-coding RNAs, and post-translational modifications. In the Conclusion and Future Perspectives section, we point out that there are still important unanswered questions. Addressing these questions is expected to lead to new insights into the functions of SOX2 in cancer, which will help design novels strategies for more effectively treating some of the most deadly cancers.

Acquisition cancer stemness, mesenchymal transdifferentiation, and chemoresistance properties by chronic exposure of oral epithelial cells to arecoline

Oral squamous cell carcinoma (OSCC), one of the most deadliest malignancies in the world, is caused primarily by areca nut chewing in Southeast Asia. The mechanisms by which areca nut participates in OSCC tumorigenesis are not well understood. In this study, we investigated the effects of low dose long-term arecoline (10 μg/mL, 90-days), a major areca nut alkaloid, on enhancement cancer stemness of human oral epithelial (OE) cells. OE cells with chronic arecoline exposure resulted in increased ALDH1 population, CD44 positivity, stemness-related transcription factors (Oct4, Nanog, and Sox2), epithelial-mesenchymal transdifferentiation (EMT) traits, chemoresistance, migration/invasiveness/anchorage independent growth and in vivo tumor growth as compared to their untreated controls. Mechanistically, ectopic miR-145 over-expression in chronic arecoline-exposed OE (AOE) cells inhibited the cancer stemness and xenografic. In AOE cells, luciferase reporter assays further revealed that miR-145 directly targets the 3′ UTR regions of Oct4 and Sox2 and overexpression of Sox2/Oct4 effectively reversed miR-145-regulated cancer stemness-associated phenomenas. Additionally, clinical results further revealed that Sox2 and Oct4 expression was inversely correlated with miR-145 in the tissues of areca quid chewing-associated OSCC patients. This study hence attempts to provide novel insight into areca nut-induced oral carcinogenesis and new intervention for the treatment of OSCC patients, especially in areca nut users.