Busulfan inhibits growth of human osteosarcoma through miR-200 family microRNAs in vitro and in vivo

Non-coding RNAs in metabolic reprogramming of bone and soft tissue sarcoma: Fundamental mechanism and clinical implication

Sarcomas, comprising approximately 1% of human malignancies, show a poor response to treatment and easy recurrence. Metabolic reprogramming play an important role in tumor development in sarcomas. Accumulating evidence shows that non-coding RNAs (ncRNAs) participate in regulating the cellular metabolism of sarcomas, which improves the understanding of the development of therapy-resistant tumors. This review addresses the regulatory roles of metabolism-related ncRNAs and their implications for sarcoma initiation and progression. Dysregulation of metabolism-related ncRNAs is common in sarcomas and is associated with poor survival. Emerging studies show that abnormal expression of metabolism-related ncRNAs affects cellular metabolism, including glucose, lipid, and mitochondrial metabolism, and leads to the development of aggressive sarcomas. This review summarizes recent advances in the roles of dysregulated metabolism-related ncRNAs in sarcoma development and stemness and describes their potential to serve as biological biomarkers for disease diagnosis and prognosis prediction, as well as therapeutic targets for treating refractory sarcomas.

Senescence-Associated Secretory Phenotype as a Hinge Between Cardiovascular Diseases and Cancer

Overlapping risks for cancer and cardiovascular diseases (CVD), the two leading causes of mortality worldwide, suggest a shared biology between these diseases. The role of senescence in the development of cancer and CVD has been established. However, its role as the intersection between these diseases remains unclear. Senescence was originally characterized by an irreversible cell cycle arrest after a high number of divisions, namely replicative senescence (RS). However, it is becoming clear that senescence can also be instigated by cellular stress, so-called stress-induced premature senescence (SIPS). Telomere shortening is a hallmark of RS. The contribution of telomere DNA damage and subsequent DNA damage response/repair to SIPS has also been suggested. Although cellular senescence can mediate cell cycle arrest, senescent cells can also remain metabolically active and secrete cytokines, chemokines, growth factors, and reactive oxygen species (ROS), so-called senescence-associated secretory phenotype (SASP). The involvement of SASP in both cancer and CVD has been established. In patients with cancer or CVD, SASP is induced by various stressors including cancer treatments, pro-inflammatory cytokines, and ROS. Therefore, SASP can be the intersection between cancer and CVD. Importantly, the conventional concept of senescence as the mediator of cell cycle arrest has been challenged, as it was recently reported that chemotherapy-induced senescence can reprogram senescent cancer cells to acquire “stemness” (SAS: senescence-associated stemness). SAS allows senescent cancer cells to escape cell cycle arrest with strongly enhanced clonogenic growth capacity. SAS supports senescent cells to promote both cancer and CVD, particularly in highly stressful conditions such as cancer treatments, myocardial infarction, and heart failure. As therapeutic advances have increased overlapping risk factors for cancer and CVD, to further understand their interaction may provide better prevention, earlier detection, and safer treatment. Thus, it is critical to study the mechanisms by which these senescence pathways (SAS/SASP) are induced and regulated in both cancer and CVD.

Mechanisms of Hydroxyurea-Induced Cellular Senescence: An Oxidative Stress Connection?

Hydroxyurea (HU) is a water-soluble antiproliferative agent used for decades in neoplastic and nonneoplastic conditions. HU is considered an essential medicine because of its cytoreduction functions. HU is an antimetabolite that inhibits ribonucleotide reductase, which causes a depletion of the deoxyribonucleotide pool and dramatically reduces cell proliferation. The proliferation arrest, depending on drug concentration and exposure, may promote a cellular senescence phenotype associated with cancer cell therapy resistance and inflammation, influencing neighboring cell functions, immunosuppression, and potential cancer relapse. HU can induce cellular senescence in both healthy and transformed cells in vitro, in part, because of increased reactive oxygen species (ROS). Here, we analyze the main molecular mechanisms involved in cytotoxic/genotoxic HU function, the potential to increase intracellular ROS levels, and the principal features of cellular senescence induction. Understanding the mechanisms involved in HU's ability to induce cellular senescence may help to improve current chemotherapy strategies and control undesirable treatment effects in cancer patients and other diseases.

Oncogenic functions of ZEB1 in pediatric solid cancers: interplays with microRNAs and long noncoding RNAs

The transcription factor Zinc finger E-box binding 1 (ZEB1) displays a range of regulatory activities in cell function and embryonic development, including driving epithelial-mesenchymal transition. Several aspects of ZEB1 function can be regulated by its functional interactions with noncoding RNA types, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Increasing evidence indicates that ZEB1 importantly influences cancer initiation, tumor progression, metastasis, and resistance to treatment. Cancer is the main disease-related cause of death in children and adolescents. Although the role of ZEB1 in pediatric cancer is still poorly understood, emerging findings have shown that it is expressed and regulates childhood solid tumors including osteosarcoma, retinoblastoma, neuroblastoma, and central nervous system tumors. Here, we review the evidence supporting a role for ZEB1, and its interplays with miRNAs and lncRNAs, in pediatric cancers.

Astaxanthin Relieves Busulfan-Induced Oxidative Apoptosis in Cultured Human Spermatogonial Stem Cells by Activating the Nrf-2/HO-1 pathway

Many child cancer patients endure anticancer therapy containing alkylating agents before sexual maturity. Busulfan (BU), as an alkylating agent, is a chemotherapy drug, causing DNA damage and cytotoxicity in germ cells. In the present study, we aimed to investigate the protective effect of astaxanthin (AST), as a potent antioxidant and powerful reactive oxygen species (ROS) scavenger, on BU-induced toxicity in human spermatogonial stem cells. For this purpose, testes were obtained from four brain-dead donors. After tissue enzymatic digestions, testicular cells were cultured for 3 weeks for spermatogonial stem cell (SSC) isolation and purification. K562 cell line was cultured to survey the effect of AST on cancer treatment. The cultured SSCs and K562 cell line were finally treated with AST (10μM), BU (0.1nM), and AST+BU. The expression of NRF-2, HO-1, SOD2, SOD3, TP53, and apoptotic genes, including CASP9, CASP3, BCL2, and BAX, were assayed using real-time PCR. Moreover, ROS level in different groups and malondialdehyde level and total antioxidant capacity in cell contraction of SSCs were measured using ELISA. Data showed that AST significantly upregulated the expression of NRF-2 gene (P<0.001) and protein (P<0.005) and also significantly decreased the production of BU-induced ROS (P<0.001). AST activated the NRF-2/HO-1 pathway that could remarkably restrain BU-induced apoptosis in SSCs. Interestingly, AST upregulated the expression level of apoptosis genes in the K562 cell line. The results of this study indicated that AST reduces the side effects of BU on SSCs without interference with its chemotherapy effect on cancerous cells through modulation of the NRF-2/HO-1 and mitochondria-mediated apoptosis pathways.

Autophagy and senescence in cancer therapy

Tumor cells can undergo diverse responses to cancer therapy. While apoptosis represents the most desirable outcome, tumor cells can alternatively undergo autophagy and senescence. Both autophagy and senescence have the potential to make complex contributions to tumor cell survival via both cell autonomous and cell non-autonomous pathways. The induction of autophagy and senescence in tumor cells, preclinically and clinically, either individually or concomitantly, has generated interest in the utilization of autophagy modulating and senolytic therapies to target autophagy and senescence, respectively. This chapter summarizes the current evidence for the promotion of autophagy and senescence as fundamental responses to cancer therapy and discusses the complexity of their functional contributions to cell survival and disease outcomes. We also highlight current modalities designed to exploit autophagy and senescence in efforts to improve the efficacy of cancer therapy.

Translational control of Bcl-2 promotes apoptosis of gastric carcinoma cells

BACKGROUND

Anti-apoptotic protein Bcl-2 plays a substantial role in the carcinogenesis, whereas the regulation for Bcl-2 in gastric carcinoma (GC) is poorly understood. Specifically, a role of microRNA (miR)-383 in the control of Bcl-2 has not been shown in GC and thus addressed in the current study.

METHODS

We investigated the levels of miR-383 and Bcl-2 in 50 GC specimens, and compared them with patients' clinical characteristics. Bioinformatics analyses and luciferase-reporter assay were applied for analyzing the relationship between Bcl-2 and miR-383. An CCK assay was used to determine the survival of Fluorouracil-treated GC cells, and apoptosis of GC cells was assessed by flow cytometric FITC Annexin V apoptosis detection assay and expression of apoptosis-associated proteins.

RESULTS

The levels of miR-383 were lower while the levels of Bcl-2 levels were higher in GC specimens, compared to tissue from the adjacent non-tumor region. Low miR-383 and high Bcl-2 seemed to be associated with high malignancy and metastasis. In GC specimens, the levels of Bcl-2 and miR-383 inversely correlated. The overall survival of miR-383-low cases was poorer. Mechanistically, miR-383 targeted the 3'-UTR of Bcl-2 mRNA to inhibit its protein translation. Overexpression of miR-383 downregulated Bcl-2, resulting in reduced survival of Fluorouracil-treated GC cells. Similar conclusion was drawn through analysis of published database.

CONCLUSION

MiR-383 reduces survival of Fluorouracil-treated GC cells through downregulating of Bcl-2.

NRF2 -617 C/A Polymorphism Impacts Proinflammatory Cytokine Levels, Survival, and Transplant-Related Mortality After Hematopoietic Stem Cell Transplantation in Adult Patients Receiving Busulfan-Based Conditioning Regimens

Busulfan (BU) is widely used in conditioning regimens prior to hematopoietic stem cell transplantation (HSCT). The exposure-escalated BU directed by therapeutic drug monitoring (TDM) is extremely necessary for the patients with high-risk hematologic malignancies in order to diminish relapse, but it increases the risk of drug-induced toxicity. BU exposure, involved in the glutathione- (GSH-) glutathione S-transferases (GSTs) pathway and proinflammatory response, is associated with clinical outcomes after HSCT. However, the expression of genes in the GSH-GSTs pathway is regulated by NF-E2-related factor 2 (Nrf2) that can also alleviate inflammation. In this study, we evaluated the influence of NRF2 polymorphisms on BU exposure, proinflammatory cytokine levels, and clinical outcomes in HSCT patients. A total of 87 Chinese adult patients receiving twice-daily intravenous BU were enrolled. Compared with the patients carrying wild genotypes, those with NRF2 -617 CA/AA genotypes showed higher plasma interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α levels, poorer overall survival (OS; RR = 3.91), and increased transplant-related mortality (TRM; HR = 4.17). High BU exposure [area under the concentration-time curve (AUC) > 9.27 mg/L × h)] was related to BU toxicities. Furthermore, NRF2 -617 CA/AA genotypes could significantly impact TRM (HR = 4.04; p = 0.0142) and OS (HR = 3.69; p = 0.0272) in the patients with high BU AUC. In vitro, we found that high exposure of endothelial cell (EC) to BU, in the absence of Nrf2, elicited the hyperstimulation of NF-κB-p65, accompanied with the elevated secretion of proinflammatory cytokines, and led to EC death. These results showed that NRF2 -617 CA/AA genotypes, correlated with high proinflammatory cytokine levels, could predict inferior outcomes in HSCT patients with high BU AUC. Thus, NRF2 -617 CA/AA genotyping combined with TDM would further optimize personalized BU dosing for sufficient efficacy and safety endpoint.

Therapy-Induced Senescence: An "Old" Friend Becomes the Enemy

For the past two decades, cellular senescence has been recognized as a central component of the tumor cell response to chemotherapy and radiation. Traditionally, this form of senescence, termed Therapy-Induced Senescence (TIS), was linked to extensive nuclear damage precipitated by classical genotoxic chemotherapy. However, a number of other forms of therapy have also been shown to induce senescence in tumor cells independently of direct genomic damage. This review attempts to provide a comprehensive summary of both conventional and targeted anticancer therapeutics that have been shown to induce senescence in vitro and in vivo. Still, the utility of promoting senescence as a therapeutic endpoint remains under debate. Since senescence represents a durable form of growth arrest, it might be argued that senescence is a desirable outcome of cancer therapy. However, accumulating evidence suggesting that cells have the capacity to escape from TIS would support an alternative conclusion, that senescence provides an avenue whereby tumor cells can evade the potentially lethal action of anticancer drugs, allowing the cells to enter a temporary state of dormancy that eventually facilitates disease recurrence, often in a more aggressive state. Furthermore, TIS is now strongly connected to tumor cell remodeling, potentially to tumor dormancy, acquiring more ominous malignant phenotypes and accounts for several untoward adverse effects of cancer therapy. Here, we argue that senescence represents a barrier to effective anticancer treatment, and discuss the emerging efforts to identify and exploit agents with senolytic properties as a strategy for elimination of the persistent residual surviving tumor cell population, with the goal of mitigating the tumor-promoting influence of the senescent cells and to thereby reduce the likelihood of cancer relapse.

FOXK1, Regulated by miR-365-3p, Promotes Cell Growth and EMT Indicates Unfavorable Prognosis in Breast Cancer

Background

Forkhead box K1 (FOXK1) is members of the FOX transcription factor family. Previous work has found out that FOXK1 promotes cell proliferation, migration and invasion in several cancers, such as gastric cancer, glioma cancer and lung cancer; however, the exact role of FOXK1 in breast cancer is still poorly known.

Methods

Here, the association between FOXK1 expression and the clinicopathological characteristics of patients with breast cancer was identified. To further decipher the functional roles of FOXK1, it was overexpressed or knocked down in MCF-7, MDA-MB-231 and MCF-10A cells. Cell Counting Kit-8, colony formation and cell cycle assays were performed to examine the proliferation of breast cancer cells. Moreover, wound-healing and Transwell invasion analyses were carried out to explore the effect of FOXK1 on breast cancer cell migration and invasion.

Results

Our findings discovered that FOXK1 promotes cell proliferation, migration and invasion in breast cancer. In addition, consistent with the previous report, FOXK1 also facilitates EMT in breast cancer. TargetScan was used to predict up-stream of FOXK1, indicating that miR-365-3p could regulate FOXK1 expression in breast cancer.

Conclusion

The findings of the present study demonstrated that miR-365-3p-FOXK1 axis plays a key role in breast cancer.

Chlorpyrifos induced oxidative stress to promote apoptosis and autophagy through the regulation of miR-19a-AMPK axis in common carp

Chlorpyrifos (CPF) has become a mainly pollution in water environment. Micro-RNAs (miRNAs) play an important part in the development of apoptosis and autophagy. However, the potential mechanism of CPF induced kidney toxicity and the roles of miRNAs are still unclear. To explore the underlying mechanism, the kidney of common carp exposed to different concentrations of CPF for 40 days was used as a research object. We found that CPF could damage the ultrastructure and function of kidney; and also caused antioxidant system disorder. CPF inhibited the mRNA level of miR-19a which improved AMP-activated protein kinase (AMPK). Furthermore, the detection of apoptosis and autophagy relative genes showed that the expressions of TSC complex subunit 2 (TSC2), light chain 3 (LC3), Dynein, tumor protein 53 (p53), Bcl-2 associated X protein (Bax), caspase-3 and caspase-9 were enhanced and the expressions of nechanistic target of rapamycin (mTOR), Ras homolog mTORC1 binding (Rheb) and B-cell lymphoma (Bcl-2) were reduced in dose-dependent way. Taken together, we conclude that CPF causes oxidative stress and miR-19a-AMPK axis disorder, thereby promotes apoptosis and autophagy in common carp kidney. Our study will provide theoretical basis for toxicology research and environmental protection of CPF.

MicroRNA-485-5p suppresses the proliferation, migration and invasion of small cell lung cancer cells by targeting flotillin-2

This study is aimed to elucidate the mechanisms underlying the role of miR-485-5p in small cell lung cancer (SCLC). The expression of miR-485-5p were quantified with real time quantitative PCR and it was found that the level of miR-485-5p was lower in SCLC tissues than normal tissues. In cultured SCLC cell lines, overexpression of miR-485-5p reduced cell proliferation, migration, and invasion in vitro, whereas knockdown of miR-485-5p performed contrary. FLOT2 expression was obviously upregulated and negatively correlated with miR-485-5p expression level in SCLC tissues. Overexpression of miR-485-5p significantly inhibited the protein expression of flotillin-2 (FLOT2) in cultured SCLC cells. Luciferase reporter assay confirmed that FLOT2 was a direct target of miR-485-5p in SCLC cells. It is concluded that miR-485-5p, as a tumor suppressor, inhibits the growth and metastasis in SCLC by targeting FLOT2. Upregulation of miR-485-5p expression may be an attractive strategy for SCLC therapy.

Chemo-resistance of A172 glioblastoma cells is controlled by miR-1271-regulated Bcl-2

MicroRNAs (miRNAs) have been reported to exert important effects on the initiation, progression and metastasis of glioblastoma multiforme (GBM). In this study, we aimed to explore the regulation role of miR-1271 on the development of GBM. We found that miR-1271 was a Bcl-2-targeting miRNA, and the levels of miR-1271was decreased in samples from patients with GBM, compared with those from corresponding normal tissue samples. On the other hand, the levels of miR-1271 were inversely related to the levels of Bcl-2, which have been significantly increased in GBM samples. The overall survival was poorer in patients with low levels of miR-1271, compared to those with high levels of miR-1271. In vitro, the chemo-resistant cell survival mediated with Bcl-2 was inhibited by overexpression of miR-1271 and was enhanced by depletion of miR-1271. Thus, the chemo-resistance of GBM cells may be promoted after suppressing miR-1271 through cell survival mediated with Bcl-2. The prognosis of patients with GBM receiving chemotherapy may be improved by overexpressing miR-1271 in cancerous cells.

The role of melatonin on chemotherapy-induced reproductive toxicity

Objectives

Reproductive malfunctions after chemotherapy still are a reason of reducing fertility and need specialized intensive care. The aim of this review was to investigate the effect of melatonin on the reproductive system under threatening with chemotherapeutic drugs.

Methods

To find the role of melatonin in the reproductive system during chemotherapy, a full systematic literature search was carried out based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in the electronic databases up to 17 April 2017 using search terms in the titles and abstracts. A total of 380 articles are screened according to our inclusion and exclusion criteria. Finally, 18 articles were included in this study.

Key findings

It has been cleared that melatonin has bilateral effects on reproductive cells. Melatonin protects normal cells via mechanisms, including decrease in oxidative stress, apoptosis, inflammation and modulating mitochondrial function, and sexual hormones. Furthermore, melatonin with antiproliferative properties and direct effects on its receptors improves reproductive injury and function during chemotherapy. On the other hand, melatonin sensitizes the effects of chemotherapeutic drugs and enhances chemotherapy-induced toxicity in cancerous cells through increasing apoptosis, oxidative stress and mitochondrial malfunction.

Conclusions

The study provides evidence of the bilateral role of melatonin in the reproductive system during chemotherapy.

miR‑4262 inhibits colon cancer cell proliferation via targeting of GALNT4

MicroRNAs (miRs) have been demonstrated to be important in the establishment and progression of colon cancer. However the underlying molecular mechanisms remain to be fully elucidated. Polypeptide N‑acetylgalactosaminyltransferase4 (GALNT4) participates in numerous cellular processes, including tumorigenesis. The present study used reverse transcription‑quantitative polymerase chain reaction and western blotting to investigate the expression levels of miR‑4262 and GALNT4 in tissues and cells. In addition, MTS and colony formation assays, and cell cycle analysis were performed to evaluate the effect of miR‑4262 on cell proliferation and the cell cycle. The findings demonstrated that miR‑4262 was a direct target of GALNT4 mRNA. Overexpression of miR‑4262 was demonstrated to decrease GALNT4 mRNA and protein expression levels, and thereby suppressed cell viability, growth and cell‑cycle progression in SW480 and SW620 colon cancer cells. In addition, knockdown of miR‑4262 significantly increased the cell viability, growth, and cell‑cycle progression of SW480 and SW620 cells. The expression level of miR‑4262 was observed to be downregulated as the expression of GALNT4 was upregulated in colon cancer tissues and cell lines. In conclusion, the results demonstrated that miR‑4262 may be involved in the development of colon cancer via targeting of GALNT4. The miR‑4262/GALNT4 axis may be a novel target for diagnosing and understanding the underlying molecular mechanism of colon cancer.

Suppression of miR-4735-3p in androgen receptor-expressing prostate cancer cells increases cell death during chemotherapy

MicroRNAs (miRNAs) play critical roles in the tumorigenesis of prostate cancer, while the biological function of miR-4735-3p is unknown. Mitogen-activated protein kinase kinase kinase 1 (MEKK1) has been shown to induce androgen receptor (AR)-dependent apoptosis in prostate cancer cells, but the regulation of MEKK1 in prostate cancer cells remains poorly defined. Here, we showed that miR-4735-3p was a MEKK1-targeting miRNA, and was highly expressed in AR+ prostate cancer specimens. Moreover, the levels of miR-4735-3p and MEKK1 inversely correlated. MiR-4735-3p-low subjects had a better overall survival, compared to miR-4735-3p-high subjects. MiR-4735-3p targeted the 3'-UTR of MEKK1 mRNA to inhibit its protein translation. Overexpression of miR-4735-3p inhibited MEKK1-mediated cell apoptosis upon docetaxel treatment, while depletion of miR-4735-3p enhanced it. Together, our data suggest that miR-4735-3p may suppress MEKK1-mediated prostate cancer cell apoptosis during chemotherapy. Inhibition of miR-4735-3p may improve the outcome of chemotherapy for some prostate cancers.

LncRNA SNHG15 contributes to proliferation, invasion and autophagy in osteosarcoma cells by sponging miR-141

Background

LncRNA small nucleolar RNA host gene 15 (SNHG15) was reported to play an oncogenic role in tumors. However, the role of SNHG15 and its molecular mechanism in osteosarcoma (OS) cells are largely unknown.

Methods

qRT-PCR was performed to evaluate the expression levels of SNHG15 and miR-141 in OS tissues and cells. Cell transfection with different siRNAs, miRNAs or pcDNAs into U2OS and MG63 cells were carried out by Lipofectamine 2000. The effects of SNHG15 and miR-141 on OS cell proliferation, invasion and the levels of autophagy-related proteins were analyzed by MTT assay, Transwell invasion/migration assay and western blot, respectively. Luciferase reporter assay was used to confirm whether SNHG15 could directly interact with miR-141.

Results

We found that up-regulation of SNHG15 was inversely correlated with miR-141 expression in OS tissues. SNHG15 knockdown and miR-141 overexpression significantly suppressed cell proliferation, invasion, migration and autophagy while SNHG15 overexpression and miR-141 repression exhibited the opposite effects on OS cells. Besides, SNHG15 could directly interact with miR-141 and regulate its expression. Furthermore, miR-141 suppressing significantly overturned the inhibition on proliferation, invasion, migration and autophagy mediated by SNHG15 knockdown while miR-141 overexpression remarkably attenuated SNHG15 overexpression-induced proliferation, invasion, migration and autophagy in OS cells.

Conclusion

Our data showed that SNHG15 contributes to proliferation, invasion, migration and autophagy in OS by negatively regulating miR-141, providing a new potential target and prognostic biomarker for the treatment of OS.

Beyond circulating microRNA biomarkers: Urinary microRNAs in ovarian and breast cancer

Breast cancer is the most common malignancy in women worldwide, and ovarian cancer is the most lethal gynecological malignancy. Women carrying a BRCA1/2 mutation have a very high lifetime risk of developing breast and ovarian cancer. The only effective risk-reducing strategy in BRCA-mutated women is a prophylactic surgery with bilateral mastectomy and bilateral salpingo-oophorectomy. However, many women are reluctant to undergo these prophylactic surgeries due to a consequent mutilated body perception, unfulfilled family planning, and precocious menopause. In these patients, an effective screening strategy is available only for breast cancer, but it only consists in close radiological exams with a significant burden for the health system and a significant distress to the patients. No biomarkers have been shown to effectively detect breast and ovarian cancer at an early stage. MicroRNAs (miRNAs) are key regulatory molecules operating in a post-transcriptional regulation of gene expression. Aberrant expression of miRNAs has been documented in several pathological conditions, including solid tumors, suggesting their involvement in tumorigenesis. miRNAs can be detected in blood and urine and could be used as biomarkers in solid tumors. Encouraging results are emerging in gynecological malignancy as well, and suggest a different pattern of expression of miRNAs in biological fluids of breast and ovarian cancer patients as compared to healthy control. Aim of this study is to highlight the role of the urinary miRNAs which are specifically associated with cancer and to investigate their role in early diagnosis and in determining the prognosis in breast and ovarian cancer.

Protection of tubular epithelial cells during renal injury via post-transcriptional control of BMP7

Severe injury of renal tubular epithelial cells may cause acute renal failure, the progression of which results in renal fibrosis, and obstructive nephropathy. Transforming growth factor β 1 and bone morphogenic protein 7 (BMP7) play contradicting roles in and coordinate the process of epithelial-to-mesenchymal transition of renal tubular epithelial cells, but the molecular regulation of BMP7 remains ill-defined. Here, we addressed this question. We found that after induction of unilateral ureteral obstruction (UUO) in mice, the increases in BMP7 mRNA were much more pronounced than BMP7 protein in kidney, suggesting the presence of post-transcriptional control of BMP7. Moreover, significant increases in a BMP7-targeting microRNA, miR-384-5p, were detected in the mouse kidney post UUO. Overexpression of miR-384-5p significantly decreased BMP7 protein, while depletion of miR-384-5p significantly increased BMP7 protein in renal epithelial cells. Bioinformatics study showed that miR-384-5p appeared to suppress BMP7 protein translation, through its direct binding to the 3'-UTR of BMP7 mRNA. Furthermore, suppression of miR-384-5p in vivo attenuated severity of renal injury by UUO. Together, our study sheds light on miR-384-5p as a crucial factor that regulates the fibrosis-related pathogenesis after renal injury, and points to miR-384-5p as a promising innovative therapeutic target for prevention of renal fibrosis.

miR-130b regulates the proliferation, invasion and apoptosis of glioma cells via targeting of CYLD

MicroRNAs are short non-coding RNAs that play important roles in gliomas. However, the role of miR-130b in glioma remains unclear. In the present study, miR-130b expression was upregulated in glioma tissues and cell lines. Kaplan-Meier analysis indicated that the upregulation of miR-130b expression correlated with poor prognoses in glioma patients. Multivariate analysis demonstrated that this upregulation and a high-grade classification were independent factors that both predicted poor outcomes for glioma patients. Dual-luciferase assays identified that the cylindromatosis (CYLD) gene is a direct target of miR-130b. Functional studies demonstrated that a miR-130b mimic significantly promoted the growth and invasion of glioma cells, while also inhibiting apoptosis via selective targeting of CYLD, which was enhanced by CYLD-targeted siRNA. In contrast, a miR‑130b inhibitor suppressed these biological behaviors, and this inhibition was reversed by CYLD-targeted siRNA. These data revealed that miR-130b could act as a novel potential diagnostic biomarker for glioma, while also demonstrating the importance of miR‑130b in the cell proliferation and progression of glioma, indicating that it may serve as a useful therapeutic target for glioma.

MicroRNA-137 inhibits growth of glioblastoma through EGFR suppression

Aberrant expression of certain microRNAs (miRNAs) has been shown to contribute to the development of Glioblastoma multiforme (GBM). However, the involvement of miR-137 in the carcinogenesis of GBM has not been reported. Here, we showed that miR-137 levels in GBM tissues were significantly lower than the paired normal brain tissue in patients' specimens. Moreover, low miR-137 levels in GBM tissue were associated with poor prognosis. In vitro, overexpression of miR-137 decreased GBM cell growth and increased cell apoptosis, while depletion of miR-137 enhanced cell growth and decreased cell apoptosis. Combined bioinformatics analysis and dual luciferase reporter assay showed that miR-137 may target the 3'-UTR of the epidermal growth factor receptor (EGFR) to reduce its protein translation, resulting in suppression of EGFR signaling in GBM cells. Together, our data suggest that reduction in miR-137 levels in GBM tissues may increase cell growth and decrease cell apoptosis, possibly through suppression of EGFR.

MicroRNA-137 inhibits BMP7 to enhance the epithelial-mesenchymal transition of breast cancer cells

Bone morphogenetic protein-7 (BMP7) is known to antagonize transforming growth factor β 1 (TGFβ1)-mediated fibrosis through suppressing epithelial-mesenchymal transition (EMT). We recently reported that BMP7 also antagonizes the effects of TGFβ1 in breast cancer (BC) tumorigenesis-related EMT. Nevertheless, the control of BMP7 expression in BC remains ill-defined. Here, we detected significantly lower levels of BMP7 and significantly higher levels of microRNA-137 (miR-137) in the BC specimens, relative to paired adjacent non-tumor breast tissue. BMP7 and miR-137 levels were correlated inversely. Additionally, the high miR-137 levels in BC specimens were correlated with reduced patient survival. In vitro, overexpression of miR-137 significantly increased cell EMT and invasion, while depletion of miR-137 significantly decreased cell EMT and invasion in BC cells. The increases in BC cell invasiveness by miR-137 appeared to result from its suppression of BMP7, through direct binding of miR-137 to the 3'-UTR of BMP7 mRNA, thereby blocking its protein translation in BC cells. This study sheds light on miR-137 as a crucial factor that enhances BC cell EMT and invasiveness, and points to miR-137 as a promising innovative therapeutic target for BC treatment.

MicroRNA-223-3p inhibits human bladder cancer cell migration and invasion

The regulation of initiation and progression during carcinogenesis of bladder carcinoma is not completely elucidated. Dysregulation of microRNAs has been detected to play critical roles in the development of various cancers, including bladder carcinoma, whereas the involvement of miR-223-3p in the tumorigenesis of bladder carcinoma has not been studied. Here, we show that significantly higher levels of nuclear receptor coactivator 1 and significantly lower levels of miR-223-3p were detected in bladder carcinoma tissue, compared to the adjacent non-tumor tissue. In addition, the levels of nuclear receptor coactivator 1 and miR-223-3p were inversely correlated. Moreover, low miR-223-3p levels in bladder carcinoma specimens were associated with poor prognosis. In vitro, depletion of miR-223-3p increased bladder carcinoma cell invasion, which was abolished by overexpression of nuclear receptor coactivator 1. Bioinformatics studies demonstrate that miR-223-3p may bind to the 3'-UTR of nuclear receptor coactivator 1 messenger RNA to inhibit its protein translation in bladder carcinoma cells. Together, our study highlights miR-223-3p as a previously unrecognized microRNA that inhibits bladder carcinoma invasiveness via nuclear receptor coactivator 1, and this finding may be important for developing innovative therapeutic targets in treating bladder carcinoma.

miR-200bc/429 Inhibits Osteosarcoma Cell Proliferation and Invasion by Targeting PMP22

Background

MicroRNAs (miRNAs) are small non-coding RNAs which play a crucial role in diverse biological processes and could contribute to cancer development and progression. MiR-200bc/429 have been found to be aberrantly expressed in osteosarcoma (OS). However, the features of miR-200bc/429 in the tumorigenesis and progress of OS remain poorly understood.

Material/Methods

The miR-200bc/429 expression was firstly identified in human OS clinical samples and cell lines by quantitative real-time PCR (qRT-PCR). After transfection with miR-200bc/429 mimics or negative control in U2OS or MG63 cells, cell proliferation was measured by CCK-8 assay. Following that, wound-healing assay and Transwell invasion assay were performed to evaluate cell migration and invasion, respectively. Finally, luciferase reporter assay and Western blot analysis were performed to determine if peripheral myelin protein-22 (PMP22) is a direct target of miR-200bc/429.

Results

Results revealed that miR-200bc/429 were significantly depressed in human OS tissues and cell lines by qRT-PCR. Then, restoration of miR-200bc/429 significantly inhibited cell proliferation (P<0.05) and invasion (P<0.05) in vitro. Luciferase reporter assay and Western blot analysis revealed that miR-200bc/429 could directly target PMP22 3′ untranslated region (UTR) and inhibit its expression in U2OS and MG63 cells.

Conclusions

These findings suggest that miR-200bc/429 inhibit OS cells proliferation and invasion by targeting PMP22, and function as a tumor suppressor and may be a patent molecular marker as well as a potential target for OS therapy.

MicroRNA-187 exerts tumor-suppressing functions in osteosarcoma by targeting ZEB2

MicroRNA-187 (miR-187) has been reported to be involved in the occurrence and development of several types of cancers; however, a role for miR-187 in osteosarcoma (OS) has not yet been reported. Here, miR-187 was found to be significantly downregulated in OS cell lines and tissue samples, and decreased miR-187 expression was shown to be correlated closely with the TNM stage and lymph node metastasis. miR-187 overexpression suppressed OS cell proliferation, colony formation, migration, invasion, and epithelial-mesenchymal transition (EMT). Mechanically, zinc finger E-box binding homeobox 2 (ZEB2) was shown to serve as a direct target of miR-187 in OS cells and the overexpression of ZEB2 rescued the miR-187-induced suppression of proliferation, colony formation, migration, and invasion in OS cells. In clinical OS specimens, ZEB2 expression levels were elevated and were inversely correlated with miR-187 expression. These results suggest that miR-187 functions as a tumor suppressor in OS, partially by targeting ZEB2, and that miR-187 can serve as a promising candidate for OS.

Long Noncoding RNA Taurine-Upregulated Gene 1 Promotes Cell Proliferation and Invasion in Gastric Cancer via Negatively Modulating miRNA-145-5p

Long noncoding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) is involved in the development and carcinogenesis of various tumors, suggesting the diagnostic potential of TUG1 in these cancers. However, the exact role of TUG1 and its underlying mechanism in gastric cancer (GC) remain unknown. In this study, the expression of TUG1 and miR-145-5p in GC cell lines and nonmalignant gastric epithelial cell lines was detected by qRT-PCR. BGC-823 and SGC-7901 cells were transfected with si-TUG1, pcDNA 3.1-TUG1, miR-145-5p mimics, or matched controls. The biological function of TUG1 and miR-145-5p in GC cell proliferation and invasion in vitro and tumor growth in vivo was investigated by MTT assay, Transwell invasion assay, and tumor xenograft experiments. The regulating relationship between TUG1 and miR-145-5 was confirmed by luciferase reporter assay. The results showed that TUG1 was significantly overexpressed and miR-145-5p was dramatically downregulated in GC cell lines. TUG1 knockdown strikingly inhibited cell proliferation and invasion in vitro and markedly suppressed tumor growth in vivo. Furthermore, TUG1 could directly bind to miR-145-5p and repress miR-145-5p expression. TUG1 overexpression significantly relieved the inhibition on GC cell proliferation and invasion in vitro and tumor growth in vivo, mediated by miR-145-5p overexpression. In conclusion, TUG1 promotes cell proliferation and invasion in GC via negatively modulating miRNA-145-5p, which undoubtedly contributes to understanding the mechanism of GC occurrence and development.

miR-574-3p acts as a tumor promoter in osteosarcoma by targeting SMAD4 signaling pathway

Human osteosarcoma is the most common primary bone malignancy sarcoma that affects primarily children and people <20 years old. In the present study, it was demonstrated that miR-574-3p was downregulated in human osteosarcoma U2OS, SAOS and MG63 cells lines as well as in osteosarcoma tissue compared with the normal tissues. Downregulation of miR-574-3p by antisense miR-574-3p, inhibited cell growth and induced cell apoptosis. Overexpression of miR-574-3p by transfection with miR-574-3p mimics promoted the growth of U2OS cells. The present study then identified mothers against decapentaplegic homolog 4 (SMAD4) as a target of miR-574-3p and SMAD4 was suppressed in miR-574-3p transfected cells. Overexpression of SMAD4 could rescue the promoting effects of miR-574-3p on cancer cell growth. In conclusion, miR-574-3p exerts tumor-promoting roles by targeting the tumor-suppressing gene SMAD4 and its downstream signaling in human osteosarcoma, which provides a novel target for the treatment.

Molecular mechanisms underlying application of serum procalcitonin and stool miR-637 in prognosis of acute ischemic stroke

We and others have reported that the serum procalcitonin (PCT) level has a demonstrative role in predicting the long-term mortality after acute ischemic stroke (AIS) in Chinese population. Nevertheless, the underlying mechanisms remain ill-defined. In the current study, we further detected a close association of stool microRNA-637 (miR-637) levels with the long-term mortality after AIS in Chinese population. Moreover, the serum PCT and stool miR-637 levels appeared to be inversely correlated. AIS patients with lower levels of stool miR-637 appeared to predict more severe mortality in the long-term. Since PCT has been shown to be mainly produced by the neuroendocrine cells in the intestine, we used an intestine neuroendocrine cell line to study the relationship between miR-637 and PCT. Bioinformatics analyses showed that miR-637 targeted the 3'-UTR of PCT mRNA to inhibit its translation, and thus the levels of PCT protein production and secretion, which was proved by luciferase reporter assay. Together, our data reveal that the molecular mechanisms underlying application of serum PCT and stool miR-637 in prognosis of AIS, in which miR-637 in intestine neuroendocrine cells may be reduced during AIS to allow more PCT to be released into serum to be detected.

MicroRNA-3713 regulates bladder cell invasion via MMP9

Transitional cell carcinoma (TCC) is the most common type of bladder cancer but its carcinogenesis remains not completely elucidated. Dysregulation of microRNAs (miRNAs) is well known to be involved in the development of various cancers, including TCC, whereas a role of miR-3713 in the pathogenesis of TCC has not been appreciated. Here, we reported that significantly higher levels of matrix metallopeptidase 9 (MMP9), and significantly lower levels of miR-3713 were detected in TCC tissue, compared to the adjacent non-tumor tissue, and were inversely correlated. Moreover, the low miR-3713 levels in TCC specimens were associated with poor survival of the patients. In vitro, overexpression of miR-3713 significantly decreased cell invasion, and depletion of miR-3713 increased cell invasion in TCC cells. The effects of miR-3713 on TCC cell growth appeared to result from its modification of MMP9 levels, in which miR-3713 was found to bind to the 3'-UTR of MMP9 mRNA to inhibit its protein translation in TCC cells. This study highlights miR-3713 as a previously unrecognized factor that controls TCC invasiveness, which may be important for developing innovative therapeutic targets for TCC treatment.

MiR-497 enhances metastasis of oral squamous cell carcinoma through SMAD7 suppression

SMAD7 is a key inhibitor of transforming growth factor β (TGFβ) receptor signaling, which regulates the alteration of cancer cell invasiveness through epithelial-mesenchymal cell conversion. Since microRNAs (miRNAs) play a potential role in the tumorigenesis, cancer cell growth and metastases of oral squamous cell carcinoma (OSCC), determination of the involved miRNAs that may regulate SMAD7-mediated OSCC cell invasion appears to be one important question. Here, we found that the levels of miR-497 were significantly increased and the levels of SMAD7 were significantly decreased in OSCC specimens, compared to the paired adjacent non-tumor tissue. Moreover, miR-497 and SMAD7 inversely correlated in OSCC specimens. The 5-year survival of the patients with higher miR-497 levels in the resected OSCC was worse than those high miR-497 levels. Bioinformatics analyses showed that miR-497 targeted the 3'-UTR of SMAD7 mRNA to inhibit its translation, which was proved by luciferase reporter assay. Furthermore, miR-497 overexpression increased SMAD7-suppressed cell invasion, while miR-497 depletion decreased SMAD7-suppressed cell invasion in OSCC cells, in both a transwell cell invasion assay and a scratch would healing assay. Together, our data suggest that suppression of miR-497 in OSCC cells may promote cancer cell invasion via suppression of SMAD7, and highlight miR-497 as an intriguing therapeutic target to prevent OSCC metastases.

IGF-1 protects tubular epithelial cells during injury via activation of ERK/MAPK signaling pathway

Injury of renal tubular epithelial cells can induce acute renal failure and obstructive nephropathy. Previous studies have shown that administration of insulin-like growth factor-1 (IGF-1) ameliorates the renal injury in a mouse unilateral ureteral obstruction (UUO) model, whereas the underlying mechanisms are not completely understood. Here, we addressed this question. We found that the administration of IGF-1 significantly reduced the severity of the renal fibrosis in UUO. By analyzing purified renal epithelial cells, we found that IGF-1 significantly reduced the apoptotic cell death of renal epithelial cells, seemingly through upregulation of anti-apoptotic protein Bcl-2, at protein but not mRNA level. Bioinformatics analyses and luciferase-reporter assay showed that miR-429 targeted the 3'-UTR of Bcl-2 mRNA to inhibit its protein translation in renal epithelial cells. Moreover, IGF-1 suppressed miR-429 to increase Bcl-2 in renal epithelial cells to improve survival after UUO. Furthermore, inhibition of ERK/MAPK signaling pathway in renal epithelial cells abolished the suppressive effects of IGF-1 on miR-429 activation, and then the enhanced effects on Bcl-2 in UUO. Thus, our data suggest that IGF-1 may protect renal tubular epithelial cells via activation of ERK/MAPK signaling pathway during renal injury.

Modulation of mesenchymal stem cells with miR-375 to improve their therapeutic outcome during scar formation

Understanding of the mechanism of cutaneous scar formation with the goal of developing potential therapies to promote scar-less wound healing appears to be extremely critical. Mesenchymal stem cells (MSCs) have a demonstrate role in promoting scar-less wound healing. However, recent studies have shown that the function of MSCs may be attenuated due to insufficient activation in vivo. Here, we aimed to increase the activity and functions of MSCs to improve their effects during scar formation. We found that overexpression of microRNA-375 (miR-375) in MSCs significantly decreased the levels of tissue inhibitor of metalloproteinases 1 (TIMP-1) protein, but not mRNA. Mechanistically, miR-375 inhibited TIMP-1 protein translation through binding to the 3'-UTR of the TIMP-1 mRNA in MSCs. Transplantation of miR-375-expressing MSCs significantly reduced the fibrosis in the scar region of the mice, possibly through reduction of reactive oxygen species (ROS), suppression of transition of myofibroblasts from fibroblasts, and increases in hepatic growth factor (HGF). Together, these data suggest that overexpression of miR-375 in MSCs may substantially improve the effects of MSCs on reduction of scar during wound healing. Our study sheds new light on a scar-less wound healing.

MicroRNA-454 regulates stromal cell derived factor-1 in the control of the growth of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant carcinoma with an extremely high lethality. We recently reported that hypoxia-inducible factor 1 (HIF-1) targets quiescin sulfhydryl oxidase 1 to facilitate PDAC cell growth and invasion. Here, we analyzed the control of another HIF-1 target, stromal cell derived factor-1 (SDF-1), in PDAC cells. We detected significantly more CD68+ macrophages in the PDAC, compared to normal human pancreas (NT). Since macrophages are recruited to the tissue through their expression of CXCR4 in response to SDF-1, we thus examined the SDF-1 levels in the PDAC specimens. Surprisingly, the SDF-1 protein but not mRNA significantly increased in PDAC, compared to NT. Moreover, a SDF-1-targeting microRNA, miR-454, was found to decrease in PDAC. Promoter luciferase assay confirmed that bindings of miR-454 to 3'-UTR of SDF-1 mRNAs inhibited SDF-1 protein translation. Co-culture of bone marrow derived macrophages and miR-454-modified PDAC cells in a transwell migration experiment showed that macrophages migrated less towards miR-454-overexpressing PDAC cells, and migrated more towards miR-454-depleted cells. Implanted miR-454-depleted PDAC cells grew significantly faster than control, while implanted miR-454-overexpressing PDAC cells grew significantly slower than control. Together, our data suggest that miR-454 may regulate SDF-1 in the control of the growth of PDAC.

Colorectal cancer cells are resistant to anti-EGFR monoclonal antibody through adapted autophagy

The epidermal growth factor receptor (EGFR) signaling plays a key role in the initiation, progression, growth and metastases of colorectal carcinoma (CRC). Monoclonal antibody against EGFR (aEGFR; Cetuximab) has been used in treating CRC but some CRCs appeared to be resistant to aEGFR therapy, with undetermined mechanisms. Here, we studied the effects of aEGFR on CRC cells in vitro. We found that aEGFR dose-dependently activated Beclin-1 in 2 CRC cell lines, HT29 and SW480. Inhibition of autophagy significantly increased the aEGFR-induced CRC cell death in an CCK-8 assay. Moreover, microRNA (miR)-216b levels were significantly downregulated in aEGFR-treated CRC cells. Bioinformatics study showed that miR-216b targeted the 3'-UTR of Beclin-1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Together, these data suggest that aEGFR may decrease miR-216b levels in CRC cells, which subsequently upregulates Beclin-1 to increase CRC cell autophagy to antagonize aEGFR-induced cell death. Strategies that increase miR-216b levels or inhibit cell autophagy may improve the outcome of aEGFR treatment in CRC therapy.

Crosstalk between Meg3 and miR-1297 regulates growth of testicular germ cell tumor through PTEN/PI3K/AKT pathway

Maternally Expressed Gene 3 (Meg3) encodes a long non-coding RNA that has been recently shown to regulate tumorigenesis through its interaction with microRNA (miR). We have recently reported that miR-1297 might play a role in the regulation of PTEN/PI3k/Akt signaling pathway in testicular germ cell tumor (TGCT). However, a crosstalk between Meg3 and miR-1297 in TGCT has not been appreciated. Here, we analyzed the levels of Meg3, miR-1297 and PTEN in TGCT specimens, compared to paired adjacent non-tumor tissue (NT), and found that Meg3 levels were significantly decreased and miR-1297 levels were unchanged in TGCT. PTEN protein but not mRNA levels significantly decreased in TGCT. Bioinformatics analyses showed that miR-1297 bound to 3'-UTR of PTEN mRNA, while miR-1297 also bound to Meg3. Luciferase report assay showed that Meg3 overexpression abolished the effects of miR-1297 on 3'-UTR of PTEN mRNA, possibly through competitive binding, which was supported by double fluorescent in situ hybridization showing co-localization of intracellular Meg3 and miR-1297 signals in TGCT cells. Moreover, Meg3 overexpression abolished the inhibitory effects of miR-1297 on PTEN, resulting in deactivation of Akt and decreases in cell growth. Together, these data demonstrate a previous unappreciated pathway in which Crosstalk between Meg3 and miR-1297 regulates growth of TFCT through PTEN/PI3K/AKT signaling. Re-expression of Meg3 may be an attractive strategy for TGCT therapy.

Autophagy regulates resistance of non-small cell lung cancer cells to paclitaxel

Paclitaxel is a chemotherapeutic drug that is effective for treating non-small cell lung cancer (NSCLC). However, some NSCLCs are not sensitive to paclitaxel treatment with undetermined underlying molecular mechanisms. In this study, we found that paclitaxel dose-dependently activated Beclin-1 in 2 NSCLC cell lines, A549 and Calu-3. Inhibition of autophagy significantly increased the paclitaxel-induced NSCLC cell death in a cell counting kit-8 (CCK-8) assay. Moreover, microRNA (miR)-216b levels were significantly downregulated in paclitaxel-treated NSCLC cells. Bioinformatics study showed that miR-216b targeted the 3'-UTR of Beclin-1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Together, these data suggest that paclitaxel may decrease miR-216b levels in NSCLC cells, which subsequently upregulates Beclin-1 to increase NSCLC cell autophagy to antagonize paclitaxel-induced cell death. Strategies that increase miR-216b levels or inhibit cell autophagy may improve the outcome of paclitaxel treatment in NSCLC therapy.

MiR-130b inhibits proliferation and induces apoptosis of gastric cancer cells via CYLD

A role of microRNA-130b (miR-130b) in the carcinogenesis of gastric cancer remains undetermined. In this study, we studied the effects and mechanism of miR-130b to the gastric cell proliferation and apoptosis. We found that the levels of miR-130b significantly up-regulated in gastric cancer tissue, compared to the paired adjacent non-tumor gastric tissue. The miR-130b levels in gastric cancer cell lines were significantly higher than those in control normal gastric tissues. Transfection with the miR-130b mimic enhanced the cell proliferation and suppressed cell apoptosis in gastric cancer cells, while transfection with the anti-sense of miR-130b (anti-miR-130b) suppressed cell proliferation and induced cell apoptosis in gastric cancer cells. Bioinformatics analyses showed that cylindromatosis gene (CYLD) was a potential target gene of miR-130b. The luciferase activity assay and western blot verified that miR-130b targeted CYLD messenger RNA (mRNA) to modulate its protein levels. Together, our study suggests that aberrantly expressed miR-130b may regulate cell apoptosis and proliferation of human gastric cancer cells via CYLD, which appears to be a promising therapeutic target for gastric cancer.

Overexpression of miR-506 inhibits growth of osteosarcoma through Snail2

Osteosarcoma (OS) is a prevalent primary bone malignancy and its distal metastasis accounts for the majority of OS-related death. MicroRNAs (miRNAs) play critical roles during cancer metastasis. Thus, elucidation of the involvement of specific miRNAs in the metastasis of OS may provide novel therapeutic targets for OS treatment. Here, we showed that in the OS specimens from patients, the levels of miR-506 were significantly decreased and the levels of Snail2 were significantly increased, compared to the paired normal bone tissue. MiR-506 and Snail2 inversely correlated in patients' specimen. Bioinformatics analyses predicted that miR-506 may target the 3'-UTR of Snail2 mRNA to inhibit its translation, which was confirmed by luciferase-reporter assay. Moreover, miR-506 overexpression inhibited Snail2-mediated cell invasiveness, while miR-506 depletion increased Snail2-mediated cell invasiveness in OS cells. Together, our data suggest that miR-506 suppression in OS cells may promote Snail2-mediated cancer metastasis.

Norcantharidin induces autophagy-related prostate cancer cell death through Beclin-1 upregulation by miR-129-5p suppression

Norcantharidin (NCTD) has an anticancer potential to allow it to be used in the treatment of some malignant cancers. However, whether NCTD may have similar anticancer effects on prostate cancer (PC) is unknown. Here, we aimed to examine the effects of NCTD on PC cells and the underlying mechanisms. We found that NCTD dose-dependently inhibited the PC cell growth, in either a cell counting kit-8 (CCK-8) assay or a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, NCTD dose-dependently increased the PC cell autophagy, through upregulation of Beclin-1. Furthermore, the Beclin-1 protein, but not mRNA, was regulated by NCTD in PC cells, suggesting post-transcriptional control of Beclin-1 by NCTD. Finally, microRNA (miR)-129-5p was found to be regulated by NCTD, and bioinformatics analyses showed that miR-129-5p targeted the 3'-UTR of Beclin-1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Together, these data suggest that NCTD may upregulate Beclin-1 through suppression of miR-129-5p to induce autophagic cell death and cell proliferation arrest in PC cells. Our study sheds light on using NCTD as a novel treatment for PC.

VEGF-activated miR-144 regulates autophagic survival of prostate cancer cells against Cisplatin

Cisplatin is a commonly used chemotherapy drug for prostate cancer (PC). However, some PCs are resistant to cisplatin treatment, while the molecular mechanisms underlying the resistance of PCs to cisplatin are not completely understood. In this study, we found that cisplatin dose-dependently activated Beclin-1 in two PC cell lines, PC3 and LNCap. Autophagy suppression significantly increased the cisplatin-induced cell death of these PC cells in a CCK-8 assay. Moreover, microRNA (miR)-144 levels were significantly downregulated in cisplatin-treated PC cells, in a VEGF-dependent manner. Bioinformatics analysis showed that miR-144 targeted the 3'-UTR of Beclin-1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. In PC patients after cisplatin treatment, low miR-144 levels appeared to predict poor outcome of patients' survival. Together, these data suggest that cisplatin may induce VEGF to suppress miR-144 levels in PC cells, which subsequently upregulates Beclin-1 to increase autophagic cell survival against cisplatin-induced cell death. Upregulation of miR-144 or suppression of cell autophagy may improve the outcome of cisplatin therapy in PC.

MiR-429 induces apoptosis of glioblastoma cell through Bcl-2

An essential role of microRNAs (miRNAs) has been acknowledged in the tumorigenesis of glioblastoma multiforme (GBM). Very recently, miR-429 was reported to have a potential of suppressing cancer growth. However, whether miR-429 may similarly regulate growth of GBM remains unknown. Here, we analyzed the levels of miR-429 and anti-apoptotic protein Bcl-2 in GBM specimens. We combined bioinformatics analyses and luciferase reporter assay to determine the relationship between miR-429 and Bcl-2 in GBM cells. Cell survival upon temozolomide treatment was analyzed in a CCK assay. Cell apoptosis was measured by fluorescein isothiocyanate (FITC) Annexin V apoptosis detection assay. We found that miR-429 levels were significantly decreased and Bcl-2 levels were significantly increased in GBM specimens, compared to the paired adjacent non-tumor brain tissue. Moreover, the levels of miR-429 and Bcl-2 inversely correlated. Low-miR-429 subjects had an overall inferior survival, compared to high-miR-429 subjects. MiR-429 targeted the 3'-UTR of Bcl-2 mRNA to inhibit its translation. Overexpression of miR-429 inhibited Bcl-2-mediated cell survival against temozolomide-induced apoptosis, while depletion of miR-429 augmented it. Together, our data suggest that miR-429 suppression in GBM promotes Bcl-2-mediated cancer cell survival against chemotherapy-induced cell death. Re-expression of miR-429 levels in GBM cells may improve the outcome of chemotherapy.

Role of miR-138 in the regulation of larynx carcinoma cell metastases

The cases of larynx carcinoma (LC) with poor prognosis largely result from the distal metastases of the primary tumor. Since microRNAs (miRNAs) play critical roles during cancer metastases, determination of the involved miRNAs in the regulation of the LC metastases may provide novel therapeutic targets for LC treatment. Here, we studied the LC specimens from the patients and found that the levels of miR-138 were significantly decreased and the levels of ZEB2, a critical factor that regulates cancer cell invasiveness, were significantly increased in LC, compared to the paired normal larynx tissue. Metastatic LC appeared to contained lower levels of miR-138. Moreover, miR-138 and ZEB2 inversely correlated in LC specimens. Bioinformatics analyses showed that miR-138 targeted the 3'-untranslated region (3'-UTR) of ZEB2 mRNA to inhibit its translation, which was confirmed in a luciferase reporter assay. Further, miR-138 overexpression inhibited ZEB2-mediated cell invasiveness, while miR-138 depletion increased ZEB2-mediated cell invasiveness in LC cells. Together, our data suggest that miR-138 suppression in LC cells may promote ZEB2-mediated cancer metastases. Thus, miR-138 appears to be an intriguing therapeutic target to prevent metastases of LC.

MiR-429 regulates gastric cancer cell invasiveness through ZEB proteins

MicroRNAs (miRNAs) play an essential role in the tumorigenesis of gastric carcinoma (GC). MiR-429 has been recently reported to inhibit GC growth; however, whether miR-429 may also regulate the invasion of GC cells is unknown. Here, we showed that miR-429 levels were significantly decreased and ZEB1 and ZEB2 levels were significantly increased in GC specimens, compared to the paired adjacent non-tumor gastric tissue. Moreover, the levels of miR-429 and ZEB1 or ZEB2 inversely correlated in GC specimens. Bioinformatics analyses showed that miR-429 targeted the 3'-untranslated region of both ZEB1 and ZEB2 mRNA to inhibit their translation, which was confirmed by luciferase reporter assay. Overexpression of miR-429 inhibited ZEB1/2-mediated cell invasiveness, while depletion of miR-429 augmented it. Together, our data suggest that miR-429 suppression in GC promotes ZEB1/2-mediated cancer cell invasion.

Pituitary tumor-transforming gene 1 enhances metastases of cervical cancer cells through miR-3666-regulated ZEB1

Early cancer metastases often occur in cervical cancer (CC) patients, resulting in poor prognosis and poor therapeutic outcome after resection of primary cancer. Hence, there is a compelling requirement for elucidating the molecular mechanisms underlying the CC cell invasiveness. Recently, the role of microRNAs (miRNAs) and pituitary tumor-transforming gene 1 (Pttg1) in the carcinogenesis of CC has been reported. Nevertheless, the relationship between miRNAs and Pttg1 remains ill-defined. Here, we showed that the levels of miR-3666 were significantly decreased and the levels of zinc finger E-box binding homeobox 1 (ZEB1) and Pttg1 were significantly increased in the CC specimens from patients, compared to the paired non-tumor tissue. Moreover, the levels of miR-3666 and ZEB1 inversely correlated. Bioinformatics analyses showed that miR-3666 targeted the 3'-untranslated region (3'-UTR) of ZEB1 messenger RNA (mRNA) to inhibit its translation, which was confirmed by luciferase reporter assay. Moreover, Pttg1 overexpression inhibited miR-3666 and subsequently increased ZEB1 and cell invasion, while Pttg1 depletion increased miR-3666 and subsequently decreased ZEB1 and cell invasion. Together, our data suggest that Pttg1 may increase CC cell metastasis, possibly through miR-3666-regulated ZEB1 levels.

Effects of radiotherapy on nasopharyngeal carcinoma cell invasiveness

Radiotherapy is widely used in the treatment of nasopharyngeal carcinoma (NPC), whereas its effects on the NPC growth, survival, and metastases have not been completely evaluated. Here, we compared the detected metastatic NPC tissues after radiotherapy (m-NPC) to the resected primary NPC tissues prior to radiotherapy (p-NPC). We detected higher levels of Snail2 protein, but not mRNA in m-NPC, compared to p-NPC. In vitro, a modest irradiation on NPC cells resulted in significant cell death, but increased Snail2 protein, but mRNA levels in the surviving NPC cells. Bioinformatics analyses showed that miR-613, which was significantly decreased in NPC cells after irradiation, targeted the 3'-UTR of Snail2 mRNA to inhibit its translation. Moreover, miR-613 overexpression inhibited Snail2-mediated cell invasiveness, while miR-613 depletion increased Snail2-mediated cell invasiveness in NPC cells. Finally, we detected significantly lower levels of miR-613 in m-NPC, compared to p-NPC. Together our data suggest that although radiotherapy induced NPC cell death, it may increase Snail2-mediated NPC cell invasiveness through downregulating miR-613.