Long noncoding RNA HAND2-AS1 inhibits cancer cell proliferation,migration, and invasion in esophagus squamous cell carcinoma by regulating microRNA-21

Long noncoding RNA (lncRNA) HAND2-AS1 is a well-characterized tumor suppressor in several types of malignancies, while its role in esophagus squamous cell carcinoma (ESCC) is unknown. In this study, we found that lncRNA HAND2-AS1 was downregulated, while microRNA-21 ( miRNA-21) was upregulated in tumor tissues than in adjacent healthy tissues of ESCC patients. Expression levels of lncRNA HAND2-AS1 and miRNA-21 were significantly and inversely correlated in tumor tissues but not in healthy tissues. Plasma levels of lncRNA HAND2-AS1 were lower in ESCC patients than in healthy controls, and downregulation of plasma lncRNA HAND2-AS1 distinguished early stage ESCC patients from healthy controls. lncRNA HAND2-AS1 overexpression resulted in downregulation of miRNA-21 in cells of ESCC cell lines and inhibited cell proliferation, migration, and invasion. miRNA-21 overexpression failed to affect lncRNA HAND2-AS1 expression but significantly attenuated the inhibitory effect of lncRNA HAND2-AS1 overexpression on cancer cell proliferation, migration, and invasion. Therefore, lncRNA HAND2-AS1 may inhibit cancer cell proliferation, migration, and invasion in ESCC by regulating miRNA-21.     

microRNA-505 negatively regulates HMGB1 to suppress cell proliferation in renal cell carcinoma

microRNAs have been recognized to regulate a wide range of biology of renal cell carcinoma (RCC). Although miR-505 has been reported to play as a suppressor in several human tumors, the physiological function of miR-505 in RCC still remain unknown. Therefore, the role of miR-505 and relevant regulatory mechanisms were investigated in RCC in this study. Quantitative real-time polymerase chain reaction was conducted to detect the expression of miR-505 and high mobility group box 1 (HMGB1) in both RCC tissues and cell lines. Immunohistochemical staining was used to assess the correlation between HMGB1 expression and PCNA expression in RCC tissues. Subsequently, the effects of miR-505 on proliferation were determined in vitro using cell counting kit-8 proliferation assays and 5-ethynyl-2′-deoxyuridine incorporation. The molecular mechanism underlying the relevance between miR-505 and HMGB1 was confirmed by luciferase assay. Xenograft tumor formation was used to reflect the proliferative capacity of miR-505 in vivo experiments. Overall, a relatively lower miR-505 and higher HMGB1 expression in RCC specimens and cell lines were found. HMGB1 was verified as a direct target of miR-505 by luciferase assay. In vitro, overexpression of miR-505 negatively regulates HMGB1 to suppress the proliferation in Caki-1; meanwhile, knock-down of miR-505 negatively regulates HMGB1 to promote the proliferation in 769P. In addition, in vivo overexpression of miR-505 could inhibit tumor cell proliferation in RCC by xenograft tumor formation. Therefore, miR-505, as a tumor suppressor, negatively regulated HMGB1 to suppress the proliferation in RCC, and might serve as a novel therapeutic target for RCC clinical treatment.     

TORC1 is required to balance cell proliferation and cell death in planarians

Multicellular organisms are equipped with cellular mechanisms that enable them to replace differentiated cells lost to normal physiological turnover, injury, and for some such as planarians, even amputation. This process of tissue homeostasis is generally mediated by adult stem cells (ASCs), tissue-specific stem cells responsible for maintaining anatomical form and function. To do so, ASCs must modulate the balance between cell proliferation, i.e. in response to nutrients, and that of cell death, i.e. in response to starvation or injury. But how these two antagonistic processes are coordinated remains unclear. Here, we explore the role of the core components of the TOR pathway during planarian tissue homeostasis and regeneration and identified an essential function for TORC1 in these two processes. RNAi-mediated silencing of TOR in intact animals resulted in a significant increase in cell death, whereas stem cell proliferation and stem cell maintenance were unaffected. Amputated animals failed to increase stem cell proliferation after wounding and displayed defects in tissue remodeling. Together, our findings suggest two distinct roles for TORC1 in planarians. TORC1 is required to modulate the balance between cell proliferation and cell death during normal cell turnover and in response to nutrients. In addition, it is required to initiate appropriate stem cell proliferation during regeneration and for proper tissue remodeling to occur to maintain scale and proportion.     

Long noncoding RNA NNT-AS1 promotes gastric cancer proliferation and invasion by regulating microRNA-363 expression

Increasing studies showed that long noncoding RNAs (lncRNAs) had crucial regulatory roles in various tumors, including gastric cancer (GC). Recent studies demonstrated that lncRNA nicotinamide nucleotide transhydrogenase-antisense RNA1 (NNT-AS1) played an important role in several tumors. However, the role and expression of NNT-AS1 in GC progression remain unknown. In our study, we indicated that NNT-AS1 expression was upregulated in GC samples compared with the nontumor tissues. We also showed that NNT-AS1 expression was upregulated in the GC cell lines. Ectopic expression of NNT-AS1 promoted GC cell line HGC-27 cell proliferation, cell cycle progression, and invasion. In addition, we showed that NNT-AS1 acted as a sponge competing endogenous RNA for microRNA-363 (miR-363), which was downregulated in the GC samples and cell lines. miR-363 expression was negatively related with NNT-AS1 expression in GC samples. Upregulated expression of miR-363 suppressed GC cell growth, cycle, and invasion. Furthermore, we reported that elevated expression of NNT-AS1 promoted GC cell proliferation, cycle, and invasion partly by suppressing miR-363 expression. These results indicated that lncRNA NNT-AS1 acted as an oncogene in the development of GC partly by inhibiting miR-363 expression.     

The putative tumor suppressor microRNA-497 modulates gastric cancer cell proliferation and invasion by repressing eIF4E

Accumulating evidence has shown that microRNAs are involved in multiple processes in gastric cancer (GC) development and progression. Aberrant expression of miR-497 has been frequently reported in cancer studies; however, the role and mechanism of its function in GC remains unknown. Here, we reported that miR-497 was frequently downregulated in GC tissues and associated with aggressive clinicopathological features of GC patients. Further in vitro observations showed that the enforced expression of miR-497 inhibited cell proliferation by blocking the G1/S transition and decreased the invasion of GC cells, implying that miR-497 functions as a tumor suppressor in the progression of GC. In vivo study indicated that restoration of miR-497 inhibited tumor growth and metastasis. Luciferase assays revealed that miR-497 inhibited eIF4E expression by targeting the binding sites in the 3′-untranslated region of eIF4E mRNA. qRT-PCR and Western blot assays verified that miR-497 reduced eIF4E expression at both the mRNA and protein levels. A reverse correlation between miR-497 and eIF4E expression was noted in GC tissues. Taken together, our results identify a crucial tumor suppressive role of miR-497 in the progression of GC and suggest that miR-497 might be an anticancer therapeutic target for GC patients.     

CFTR activation suppresses glioblastoma cell proliferation,migration and invasion

The aim of this study was to investigate the function of Cystic fibrosis transmembrane conductance regulator (CFTR) in human glioblastoma (GBM) cells. Data dining results of the Human Protein Atlas showed that low CFTR expression was associated with poor prognosis for GBM patients. We found that CFTR protein expression was lower in U87 and U251 GBM cells than that in normal humane astrocyte cells. CFTR activation significantly reduced GBM cell proliferation. In addition, CFTR activation significantly abrogated migration and invasion of GBM cells. Besides, CFTR activator Forskolin treatment markedly reduced MMP-2 protein expression. These effects of CFTR activation were significantly inhibited by CFTR inhibitor CFTRinh-172 pretreatment. Our findings suggested that JAK2/STAT3 signaling was involved in the anti-glioblastoma effects of CFTR activation. Moreover, CFTR overexpression in combination with Forskolin induced a synergistic anti-proliferative response in U87?cells. Overall, our findings demonstrated that CFTR activation suppressed GBM cell proliferation, migration and invasion likely through the inhibition of JAK2/STAT3 signaling.     

CXCL13 mediates prostate cancer cell proliferation through JNK signalling and invasion through ERK activation

Objectives: The focus of this study was to determine the dedicator of cytokinesis 2 (DOCK2), extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase-1 (JNK) and Akt signals involved in CXCL13-mediated prostate cancer (PCa) cell invasion and proliferation. Materials and methods: Androgen-sensitive (LNCaP), hormone-refractory (PC3) cells and normal cells (RWPE-1) were used to determine CXCL13-mediated PCa cell invasion and proliferation. Immuno-blotting, fast activated cell-based (FACE) ELISA, caspase activity, cell invasion and proliferation assays were performed to ascertain some of the signalling events involved in PCa cell proliferation and invasion. Results: Unlike androgen-sensitive LNCaP cells, we report for the first time that the hormone-refractory cell line, PC3, expresses DOCK2. CXCL13-mediated LNCaP and PC3 cell invasion was regulated by Akt and ERK1/2 activation in a DOCK2-independent fashion. CXCL13 also promoted LNCaP cell proliferation in a JNK-dependent fashion even in the absence of DOCK2. In contrast, CXCL13 induced PC3 cell proliferation through JNK activation, which required DOCK2. Conclusions: Our results show CXCL13-mediated PCa cell invasion requires Akt and ERK1/2 activation and suggests a new role for DOCK2 in proliferation of hormone-refractory CXCR5-positive PCa cells.     

microRNA-510-5p promotes thyroid cancer cell proliferation,migration, and invasion through suppressing SNHG15

SNHG15 has been suggested to be correlated with clinical progression and prognosis, and function as tumor suppressive long noncoding RNA in thyroid cancer at our previous study. SNHG15 was proposed to be a potential target for miR-510-5p at LncBase Predicted database. Thus, the aim of this study was to explore the relationship between miR-510-5p and SNHG15 in thyroid cancer, and the clinical significance of miR-510-5p in patients with thyroid cancer. In our results, levels of miR-510-5p expression were increased in thyroid cancer tissues and cell lines compared with adjacent normal thyroid tissues and normal thyroid cell line, respectively. There was a statistically negative correlation between SNHG15 expression and miR-510-5p expression in thyroid cancer tissues. Moreover, miR-510-5p directly bound to SNHG15, and negatively regulated SNHG15 expression in thyroid cancer cells. Furthermore, miR-510-5p promoted thyroid cancer cell proliferation, migration, and invasion through suppressing SNHG15. Finally, high miR-510-5p expression was observed in tumor tissues with advanced clinical stage or lymph node metastasis. In conclusion, we provide evidence to support a pivotal role for miR-510-5p in regulating thyroid cancer cell proliferation, migration, and invasion.     

Calcium-activated nucleotidase 1 silencing inhibits proliferation,migration, and invasion in human clear cell renal cell carcinoma

Calcium-activated nucleotidase 1 (CANT1, belongs to the apyrase family, is widely expressed in various organs. However, the biological function of CANT1 remains poorly explored. In this study, we aimed to investigate the expression profile and functions of CANT1 in clear cell renal cell carcinoma (ccRCC). Our data show that the protein level of CANT1 was significantly higher in tumor tissues than in adjacent normal tissues. CANT1 silencing suppressed cell proliferation, migration, and invasion obviously in 769-P and 786-O cells, arrested cell cycle in S phase and promoted apoptosis in 769-P cells. In conclusion, the present study shows the different expression mode of CANT1 in human ccRCC tumor tissue and adjacent normal tissue, denotes the function of CANT1 in ccRCC cells and provides potential molecular mechanisms and pathways of CANT1 antitumor function in ccRCC.     

Tumor suppressive microRNA-133a regulates novel targets: moesin contributes to cancer cell proliferation and invasion in head and neck squamous cell carcinoma

Recently, many studies suggest that microRNAs (miRNAs) contribute to the development, invasion and metastasis of various types of human cancers. Our recent study revealed that expression of microRNA-133a (miR-133a) was significantly reduced in head and neck squamous cell carcinoma (HNSCC) and that restoration of miR-133a inhibited cell proliferation, migration and invasion in HNSCC cell lines, suggesting that miR-133a function as a tumor suppressor. Genome-wide gene expression analysis of miR-133a transfectants and TargetScan database showed that moesin (MSN) was a promising candidate of miR-133a target gene. MSN is a member of the ERM (ezrin, radixin and moesin) protein family and ERM function as cross-linkers between plasma membrane and actin-based cytoskeleton. The functions of MSN in cancers are controversial in previous reports. In this study, we focused on MSN and investigated whether MSN was regulated by tumor suppressive miR-133a and contributed to HNSCC oncogenesis. Restoration of miR-133a in HNSCC cell lines (FaDu, HSC3, IMC-3 and SAS) suppressed the MSN expression both in mRNA and protein level. Silencing study of MSN in HNSCC cell lines demonstrated significant inhibitions of cell proliferation, migration and invasion activities in si-MSN transfectants. In clinical specimen with HNSCC, the expression level of MSN was significantly up-regulated in cancer tissues compared to adjacent non-cancerous tissues. These data suggest that MSN may function as oncogene and is regulated by tumor suppressive miR-133a. Our analysis data of novel tumor-suppressive miR-133a-mediated cancer pathways could provide new insights into the potential mechanisms of HNSCC oncogenesis.     

Monocarboxylate transporter 1 promotes proliferation and invasion of renal cancer cells by mediating acetate transport

One hallmark of renal cell carcinoma (RCC) is metabolic reprogramming, which involves elevation of glycolysis and upregulation of lipid metabolism. However, the mechanism of metabolic reprogramming is incompletely understood. Monocarboxylate transporter 1 (MCT1) promotes transport for lactate and pyruvate, which are crucial for cell metabolism. The aim of present study was to investigate the function of MCT1 on RCC development and its mechanism on metabolic reprogramming. The results showed that MCT1 messenger RNA and protein levels significantly increased in cancer tissues of ccRCC compared to normal tissue. MCT1 was further found to mainly located in the cell membrane of RCC. The knockdown of MCT1 by RNAi significantly inhibited proliferation and migration of 786-O and ACHN cells. MCT1 also induced the expressions of proliferation marker Ki-67 and invasion marker SNAI1. Moreover, we also showed that acetate treatment could upregulate the expression of MCT1, but not other MCT isoforms. On the other hand, MCT1 was involved in acetate transport and intracellular histone acetylation. In summary, this study revealed that MCT1 is abnormally high in ccRCC and promotes cancer development. The regulatory effect of MCT1 on cell proliferation and invasion maybe mediated by acetate transport.     

microRNA-501-5p promotes cell proliferation and migration in gastric cancer by downregulating LPAR1

In spite of the achievement in treatment, the gastric cancer (GC) mortality still remains high. MicroRNAs (miRNAs) are a group of small noncoding RNAs that play a crucial part in tumor progression. In this study, we explored the expression and function of microRNA-501-5p (miR-501-5p) in GC cell lines. Quantitative real-time polymerase chain reaction assay results suggested that miR-501-5p was significantly upregulated in GC tissues and cell lines. And, the Cell Counting Kit-8 colony formation and cell migration assay results showed that the downregulation of miR-501-5p decreased GC cell proliferation and migration. Besides that, we found that GC cell cycle was arrested in G2 phase and cell apoptosis rate was increased by silencing the expression of miR-501-5p in GC cell lines using the flow cytometry. We also found that miR-501-5p could directly target lysophosphatidic acid receptor 1 (LPAR1) and negatively regulate LPAR1 expression in GC cell lines by performing dual-luciferase reporter gene assay and Western blot analysis. And, LPAR1 was significantly downregulated in GC tissues and inversely correlated with miR-501-5p expression. Furthermore, LPAR1 downregulation promoted cell proliferation and migration, which were attenuated by cotransfection of miR-501-5p inhibitor in GC cells. In conclusion, miR-501-5p can promote GC cell proliferation and migration by targeting and downregulating LPAR1. miR-501-5p/LPAR1 may become a potential therapeutic target for GC treatment.     

Increased microRNA-223 in Helicobacter pylori-associated gastric cancer contributed to cancer cell proliferation and migration

Dysregulation of microRNA-223 (miR-223) was associated with gastric cancer (GC), in which Helicobacter pylori (H. pylori) played important roles. However, the mechanism of relationships between miR-223 and H. pylori-associated GC was largely undiscovered. Here, we found the overexpression of miR-223 was related with H. pylori positive infection in vivo and in vitro in GC by relative quantification of qRT-PCR. Upregulated miR-223 was responsible for the poorer prognosis of GC with H. pylori positive, also. The result indicated not only overexpression of miR-223 stimulated the proliferation by CCK-8 assays and colony formation of H. pylori associated GC cells, but also migration and invasion by scratch assay and transwell invasion assays in vitro. Above all, all our data declared H. pylori infection played an important role in developing GC according to overexpression of miR-223, which increased cancer cell proliferation and migration.     

Over-expression of LSD1 promotes proliferation, migration and invasion in non-small cell lung cancer

Background

Lysine specific demethylase 1 (LSD1) has been identified and biochemically characterized in epigenetics, but the pathological roles of its dysfunction in lung cancer remain to be elucidated. The aim of this study was to evaluate the prognostic significance of LSD1 expression in patients with non-small cell lung cancer (NSCLC) and to define its exact role in lung cancer proliferation, migration and invasion.

Methods

The protein levels of LSD1 in surgically resected samples from NSCLC patients were detected by immunohistochemistry or Western blotting. The mRNA levels of LSD1 were detected by qRT-PCR. The correlation of LSD1 expression with clinical characteristics and prognosis was determined by statistical analysis. Cell proliferation rate was assessed by MTS assay and immunofluorescence. Cell migration and invasion were detected by scratch test, matrigel assay and transwell invasion assay.

Results

LSD1 expression was higher in lung cancer tissue more than in normal lung tissue. Our results showed that over-expression of LSD1 protein were associated with shorter overall survival of NSCLC patients. LSD1 was localized mainly to the cancer cell nucleus. Interruption of LSD1 using siRNA or a chemical inhibitor, pargyline, suppressed proliferation, migration and invasion of A549, H460 and 293T cells. Meanwhile, over-expression of LSD1 enhanced cell growth. Finally, LSD1 was shown to regulate epithelial-to-mesenchymal transition in lung cancer cells.

Conclusions

Over-expression of LSD1 was associated with poor prognosis in NSCLC, and promoted tumor cell proliferation, migration and invasion. These results suggest that LSD1 is a tumor-promoting factor with promising therapeutic potential for NSCLC.     

BMP-6 inhibits cell proliferation by targeting microRNA-192 in breast cancer

Although bone morphogenetic protein-6 (BMP-6) has been identified as a tumor suppressor associated with breast cancer differentiation and metastasis, the potential roles of BMP-6 in regulating cell cycle progression have not been fully examined. In the present study, we provide the novel finding that induction of BMP-6 in MDA-MB-231 breast cancer cells significantly inhibits cell proliferation by decreasing the number of cells in S phase of the cell cycle, resulting in inhibition of tumorigenesis in a nude mouse xenograft model. Further investigation indicated that BMP-6 up-regulates the expression of microRNA-192 (miR-192) in MDA-MB-231 cells. Elevated expression of miR-192 caused cell growth arrest, which is similar to the effect of BMP-6 induction. Importantly, depletion of endogenous miR-192 by miRNA inhibition significantly attenuated BMP-6-mediated repression of cell cycle progression. In breast cancer tissue, miR-192 expression is significantly down-regulated in tumor samples and positively correlates with the expression of BMP-6, demonstrating the inhibitory effect of BMP-6 on cell proliferation through miR-192 regulation. Additionally, using the RT² Profiler PCR Array, retinoblastoma 1 (RB1) was identified as a direct target of the BMP-6/miR-192 pathway in regulating cell proliferation in breast cancer. In conclusion, we have identified an important role for BMP-6/miR-192 signaling in the regulation of cell cycle progression in breast cancer. Furthermore, BMP-6/miR-192 was expressed at low levels in breast cancer specimens, indicating that this pathway might represent a promising therapeutic target for breast cancer treatment.     

Upregulated microRNA-224 promotes ovarian cancer cell proliferation by targeting KLLN

Human epithelial ovarian cancer is a complex disease, with low 5-yr survival rate largely due to the terminal stage at diagnosis in most patients. MicroRNAs play critical roles during epithelial ovarian cancer progression in vivo and have also been shown to regulate characteristic of ovarian cancer cell line in vitro. Alterative microRNA-224 (microRNA-224) expression affects human epithelial ovarian cancer cell survival, apoptosis, and metastasis. However, people know little about the effects of microRNA-224 on epithelial ovarian cancer cell proliferation. In the current study, we found that the microRNA-224 expression level of human syngeneic epithelial ovarian cancer cells HO8910 (low metastatic ability) was lower than that of HO8910PM (high metastatic ability). Furthermore, microRNA-224 was confirmed to target KLLN in HO8910 and HO8910PM. The known KLLN downstream target cyclin A was regulated by microRNA-224 in HO8910 and HO8910PM. In addition, overexpression of microRNA-224 enhanced the proliferation abilities of HO8910 and knockdown of microRNA-224 suppressed the proliferation abilities of HO8910PM by KLLN-cyclin A pathway. Our results provide new data about microRNAs and their targets involved in proliferation of epithelial ovarian cancer cells by modulating the downstream signaling.     

SEACing the GAP that nEGOCiates TORC1 activation

The target of rapamycin complex 1 (TORC1) regulates eukaryotic cell growth in response to a variety of input signals. In S. cerevisiae, amino acids activate TORC1 through the Rag guanosine triphosphatase (GTPase) heterodimer composed of Gtr1 and Gtr2 found together with Ego1 and Ego3 in the EGO complex (EGOC). The GTPase activity of Gtr1 is regulated by the SEA complex (SEAC). Specifically, SEACIT, a SEAC subcomplex containing Iml1, Npr2, and Npr3 functions as a GTPase activator (GAP) for Gtr1 to decrease the activity of TORC1 and, consequently, growth, after amino acid deprivation. Here, we present genetic epistasis data, which show that SEACAT, the other SEAC subcomplex, containing Seh1, Sea2–4, and Sec13, antagonizes the GAP function of SEACIT. Orthologs of EGOC (Ragulator), SEACIT (GATOR1), and SEACAT (GATOR2) are present in higher eukaryotes, highlighting the remarkable conservation, from yeast to man, of Rag GTPase and TORC1 regulation.