MiRNA-148a inhibits cell growth and drug resistance by regulating WNT10a expression in renal cell carcinoma

BackgroundWe aimed to explore miR-148a exerts a tumor suppressor effect and arsenic trioxide (As₂O₃) sensitivity on renal cell carcinoma (RCC).MethodsWe performed polymerase chain reaction (PCR) on 42 pairs of tumor and paracancerous samples collected from RCC patients to investigate the miR-148a expression; meanwhile, we analyzed the interplay between clinical indicators and miR-148a expression of RCC. Then, the influence of miR-148a overexpression on the functions of RCC cells were analyze using transwell migration assay, Cell Counting Kit-8 (CCK-8), and cell wound healing assay. Furthermore, the ability of miR-148a to sensitize Caki-1 cells treated with As₂O₃ were detected using flow cytometry. Finally, the relevant mechanism of miR-148a on the downstream gene Wnt family member 10A (WNT10a) was explored by cell reverse method.ResultsThe results from RCC patients indicated a significantly lower miR-148a level than adjacent tissues. The low miR-148a expression increased prevalence of distant metastasis and decreased survival rate compared to those with high expression in patients. In the RCC cell lines, the proliferation and metastasis ability of the miR-148a mimic group was remarkably lower than the miR-NC group. At the same time, it was verified that WNT10a was remarkably higher cell lines and RCC tissues; and negatively related to miR-148a expression. In addition, miR-148a mimics were found to remarkably reduce the protein expression of WNT10a. In the cell reverse experiment, overexpression of WNT10a was confirmed to offset the miR-148a mimics effect on metastasis and proliferation of RCC cells. In addition, an increase in relative apoptosis was detected in As₂O₃ treated with/without miR-148a mimics for 48 hours, and apoptosis was significantly reduced after transfection with WNT10a in the Caki-1 cell line and significantly reduced after combined treatment.ConclusionsThe study revealed that miR-148a is associated with distant metastases and leads to poor prognosis in RCC patients. Moreover, miR-148a inhibit the malignant progression and increase the sensitivity of RCC cells to As₂O₃ by regulating WNT10a.     

Up-regulation of miR-181a in clear cell renal cell carcinoma is associated with lower KLF6 expression,enhanced cell proliferation,accelerated cell cycle transition,and diminished apoptosis

Objectives

Dysregulated expression of miR-181a accompanies tumorigenesis in many human cancers. However, in clear cell renal cell carcinoma (ccRCC), the role of miR-181a remains unclear. The aim of this study was to investigate biological functions of miR-181a and its expression levels in ccRCC tissues and cancer cell lines.

Circ_0000274 contributes to renal cell carcinoma progression by regulating miR-338-3p/NUCB2 axis and JAK1/STAT3 pathway

BackgroundKidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). Accumulating evidence has demonstrated that circular RNAs (circRNAs) are essential players in tumor advancement. However, the functions of circ_0000274 in renal cell carcinoma (RCC) are barely explored.MethodsThe primary RCC cell lines 786-O and A498 were used in this study. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was employed for the RNA levels of circ_0000274, microRNA-338-3p (miR-338-3p) and nucleobindin 2 (NUCB2). RNase R assay was conducted to analyze the feature of circ_0000274.Cell Counting Kit-8 (CCK-8) assay, colony formation assay, transwell assay, tube formation assay and flow cytometry analysis were conducted for cell viability, colony formation, metastasis, angiogenesis and apoptosis, respectively. Western blot assay was utilized for protein levels. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were adopted to analyze the associations of circ_0000274 RNA, miR-338-3p RNA and NUCB2 protein. Murine xenograft model was established to explore the function of circ_0000274 RNA in vivo. Immunohistochemistry (IHC) assay was used to analyze NUCB2 protein level in xenograft tumors.ResultsCompared to normal tissues and cells, circ_0000274 RNA level was elevated in RCC tissues and cells. Knockdown of circ_0000274 RNA suppressed cell viability, colony formation, metastasis and tube formation and promoted apoptosis in RCC cells in vitro. Circ_0000274 RNA sponged miR-338-3p RNA to positively regulate NUCB2 protein in RCC cells. Inhibition of miR-338-3p reversed the impacts of circ_0000274 knockdown on RCC cell malignant behaviors. MiR-338-3p RNA overexpression repressed the malignant phenotypes of RCC cells, while NUCB2 protein elevation could abrogate the effect. Moreover, circ_0000274 RNA knockdown blocked tumorigenesis in vivo. Besides, circ_0000274 RNA knockdown inactivated the JAK1/STAT3 protein signaling pathway.ConclusionCirc_0000274 RNA functioned as an oncogene in RCC development by regulating miR-338-3p RNA/NUCB2 protein axis and activating the JAK1/STAT3 protein signaling pathway.     

microRNA-107 functions as a candidate tumor suppressor gene in renal clear cell carcinoma involving multiple genes

BackgroundMicroRNAs (miRNAs) are small RNAs with oncogenic and tumor-suppressing functions in cancer. miRNAs not only regulate various target genes but also participate in vital signaling pathways.Methods and resultsThe tumor-suppressing function of miRNA-107 (miR-107) was confirmed in clear cell renal cell carcinoma in 52 paired clinical specimens and renal cell carcinoma cell lines. Significant correlations were noted between clinical features and miR-107 expression level. Lentiviral vector and biosynthesis mimics were used to overexpress pre-miR-107 or mimicked miR-107 to investigate further the tumorigenesis of miR-107 in vivo and in vitro. Cell proliferation and invasiveness were inhibited in the 786-O cell line after miR-107 was delivered. High miR-107 level expression can apparently induce cell cycle arrest at the G2/M phase and retard tumor growth in nude mice. In addition, eukaryotic translation initiation factor 5 was found to be a direct target of miR-107 and exhibited an inverse relationship with miR-107. It was seen that p53 and VHL genes, which are implicated in renal tumors, were associated with miR-107.ConclusionIn summary, our results showed that miR-107 can inhibit cell proliferation and invasiveness of renal cell carcinoma. Furthermore, this study may provide a potential therapeutic regimen for clear cell renal cell carcinoma treatment.     

MicroRNAs as potential predictors of extreme response to tyrosine kinase inhibitors in renal cell cancer

BackgroundMicroRNAs play an important role as modulators of gene expression in several biological processes and are closely related to development and cell differentiation regulation. Previous works have revealed a potential predictive role for miRNAs in different tumor types. This study aims to analyze the ability of miRNAs in segregating metastatic renal cell carcinoma patients according to their responses to tyrosine kinase inhibitors (TKIs).MethodsExtreme responders were considered in the study and were defined as those patients that either had a long-term response (LR) (progression-free survival ˃11 months) or those that were primary refractory (PR) (progression as best response). The expression of 754 miRNAs was analyzed in tumor tissue of these 2 sets of patients.ResultsIn a study cohort (n = 15) 4 miRNAs were significantly associated with patient response and differentially expressed in PR vs. LR (up-regulated in PR vs. LR: miR-425-5p, down-regulated in PR vs. LR: miR-139-3p, let-7d and let-7e). Further analysis in a validation cohort (n = 36) revealed similar results.ConclusionThe present data strength the potential role of miRNAs as a tool to predict treatment outcomes in patients with metastatic renal cell carcinoma treated with TKIs.     

Renal cancer stem cell-derived sEVs impair renal function by inducing renal cell ERS and apoptosis in mice

BackgroundCancer stem cells (CSCs) have been confirmed to participate in tumorigenesis, development, and metastasis, and to affect the local environment in normal tissues. Extracellular vesicles derived from CSCs (CSC-EVs) affect the local environment, contributing to tumor metastasis. However, the effect of small extracellular vesicles (sEVs) from renal CSCs (RCSCs) on renal function has not been studied. This study aimed to establish the impact of RCSC-sEVs on the renal function.MethodsRCSC-sEVs were isolated from cell lines and locally injected into C57 mouse kidneys to observe the effect of RCSC-sEVs on the renal function. 24-hour urinary protein and serum creatinine were examined for renal function evaluation. Periodic Acid-Schiff (PAS) and immunochemistry (IHC) staining were applied for investigations of the pathological changes. Western blot (WB), flow cytometry (FCM), real-time quantitative polymerase chain reaction (RT-qPCR), and TUNEL were employed to assess cell apoptosis and endoplasmic reticulum stress (ERS).ResultsWe found that RCSC-sEVs induced apoptosis and ERS in the mouse kidneys and eventually led to a decrease in the renal function. In vivo, RCSC-sEVs, applied by local injection, induced a continual increase in the 24-hour urinary protein and serum creatinine. In vitro, RCSC-sEVs induced HK2 cell ERS and apoptosis, which was caused by miR-142-3p and was confirmed by antagomir treatment. Further research showed that the miR-142-3p carried by RCSC-sEVs regulated ERp44, thus activating the PERK-CHOP pathway, which induced ERS and led to cell apoptosis.ConclusionsRenal function impairment during tumor development is induced not only by tumor invasion but also by RCSC-sEVs-induced renal cell apoptosis. As a natural vector of miR-142-3p, RCSC-sEVs return to the kidney cells and interfered with the expression of ERp44, inducing ERS and ultimately leading to apoptosis of normal renal cells and renal function impairment.     

miR-503 regulates metastatic function through Rho guanine nucleotide exchanger factor 19 in hepatocellular carcinoma

Background

Our previous work described a metastasis-related microRNAs expression profiling and revealed miR-503 regulating metastatic function in hepatocellular carcinoma (HCC) cells. Here, we investigate to define the mechanism of miR-503 regulating metastasis in HCC.

Materials and methods

The expressions of miR-503 in HCC cell lines and clinical tissues with different metastatic potential were investigated. Meanwhile, a metastatic human HCC cell BALB/c nude mice model was used to investigate whether miR-503 regulates metastasis of HCC in vivo. Furthermore, luciferase activity of reporter gene, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), fluorescence-activated cell sorting analysis (FACS), and invasion assay were carried out to characterize the mechanism of miR-503 regulating metastasis in HCC.

Results

We confirmed the negative correlation between miR-503 expression and metastatic potential of HCC in cell lines and in clinical HCC tissues. We also showed that overexpression of miR-503 resulted in inhibition of proliferation and metastasis of HCC in vivo. Furthermore, we demonstrated that ARHGEF19 is a direct target gene of miR-503. Finally, our results indicated that ARHGEF19 overcomes the suppressive influence of miR-503 in HCC cells.

Conclusions

Our results suggest an important role of miR-503 in inhibiting metastasis of HCC through deregulating ARHGEF19.     

Expression of CX3CR1 associates with cellular migration,metastasis, and prognosis in human clear cell renal cell carcinoma

ObjectivesThe identification of critical proteins regulating cancer cell metastasis, in clear cell renal cell carcinoma (CCRCC), is important for prediction of prognosis, prevention of metastasis, and treatment of this lethal malignancy. In the present study, we evaluated the role of CX3CR1 in cellular adhesion, migration, and metastasis in CCRCC. We further investigated the downstream molecular signaling mechanism of fractalkine (FKN)-CX3CR1-induced migration and metastasis.Materials and methodsThe expression and localization of CX3CR1 in RCC cell lines were assessed by immunofluorescence analysis. The migration of cancer cells was examined by wound healing and transwell migration assay. The expression level of CX3CR1 and FKN in 78 CCRCC individual samples, 16 normal kidney cortex tissue samples, and 16 cases of metastatic lesions of CCRCC were evaluated using immunohistochemical analysis on tissue microarray. The signal pathway of functional FKN was analyzed by the use of the western-blotting method and inhibitory migration assay.ResultsCX3CR1 was expressed in human RCC cell lines, and only membrane positive cells were responsible for FKN-induced cell migration. Extracellular signal-related kinases (ERK1/2) and phosphatidyl-inositide 3 kinase/Akt (PI3K/Akt) were each activated upon soluble FKN stimulation in a time-dependent manner, whereas blockades of MEK, PI3K, and G proteins prevented FKN-mediated cellular migration. Furthermore, CCRCC tissue microarray immunohistochemistry data revealed a clear association of strong CX3CR1 expression with tumor metastasis and poor prognosis.ConclusionsCX3CR1 expression is associated with the process of cellular migration in vitro and tumor metastasis of CCRCC in vivo. Both clinical and molecular cellular evidence suggest that CX3CR1 is a potential marker and therapeutic target for CCRCC prognostic prediction and treatment.     

Effect of platelet-derived growth factor-B on renal cell carcinoma growth and progression

BackgroundPlatelet-derived growth factor-B (PDGF-B) expression promotes the proliferation of mural cells surrounding the blood vessels during angiogenesis. The effect of PDGF-B involved in angiogenesis on tumor growth and progression in clear cell renal cell carcinoma (ccRCC) is unknown.MethodsWe examined the expression of PDGF-B and its receptor PDGFR-β in 174 patients with ccRCC by microarray analysis. Cancer-specific survival was estimated using the Kaplan-Meier method. PDGF-B–transfected and mock-transfected ACHN cells were implanted into mice to induce tumor formation and tumor growth, respectively, and progression in mice models was assessed using immunohistochemistry and histomorphology. The role of PDGF-B during angiogenesis in vitro was evaluated by flow cytometry analysis, cell migration, and tube formation assay.ResultsHigh expression of PDGF-B was associated with significantly decreased risk of cancer-specific mortality (P≤0.001). The data indicated significant inhibition of tumor growth (P≤0.05) and a reduction in proliferating tumor cells (P = 0.019) in vivo. PDGF-B also inhibits tumor metastasis and invasion events in tumor-bearing mice models. In vitro studies revealed that the tube formation capability of vascular smooth muscle cells (VSMCs), which are believed to be the precursors to pericytes in vivo, significantly induced by PDGF-B. The PDGF-B overexpression also results in a tendency to reside in S and G2/M phases of the cell cycle (P = 0.001) and increasing migration capability of VSMCs (P≤0.001).ConclusionOur results demonstrated that PDGF-B, which increased VSMCs proliferation and migration capability during angiogenesis, limited tumor growth and progression in ccRCC. Therefore, PDGF-B may be a novel and promising prognostic marker.     

Circ_0000069 contributes to the growth,metastasis and glutamine metabolism in renal cell carcinoma (RCC) via regulating miR-125a-5p-dependent SLC1A5 expression

BackgroundCircular RNAs (circRNAs) have emerged as critical mediators in various cancers, including renal cell carcinoma (RCC). In the present research, the functions of circ_0000069 in RCC were explored.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) assay, western blot assay and immunohistochemistry (IHC) assay were performed for the expression of circ_0000069, microRNA-125a-5p (miR-125a-5p) and solute carrier family 1 member 5 (SLC1A5). Cell Counting Kit-8 (CCK-8) assay and 5′-ethynyl-2′-deoxyuridine (EdU) assay were performed for cell proliferation. Flow cytometry assay was manipulated for cell apoptosis. Transwell assay and wound-healing assay were utilized for cell invasion and migration. Glutamine metabolism level was evaluated by examining glutamine consumption, α-ketoglutarate production and glutamate production. Dual-luciferase reporter assay was used to analyze the relationships of circ_0000069, miR-125a-5p and SLC1A5. Murine xenograft model assay was conducted to analyze the function of circ_0000069 in vivo.ResultsCirc_0000069 level was abnormally upregulated in RCC tissues and cells. Knockdown of circ_0000069 inhibited the proliferation, invasion, migration and glutamine metabolism and promoted the apoptosis in RCC cells in vitro and restrained tumor growth in vivo. Circ_0000069 served as the sponge for miR-125a-5p. MiR-125a-5p inhibition ameliorated the effects of circ_0000069 knockdown on RCC cell malignant behaviors. SLC1A5 was identified as the target gene of miR-125a-5p. Moreover, miR-125a-5p overexpression repressed the progression of RCC cells, while SLC1A5 elevation abrogated the effect.ConclusionCirc_0000069 knockdown inhibited the carcinogenesis of RCC by regulating miR-125a-5p/SLC1A5 axis.     

MiR-134通过靶向调节KRAS抑制786-0肾透明细胞癌细胞上皮间质转化过程

目的探索miR-134在肾癌组织中的表达并研究其对肾透明细胞癌细胞786-0上皮间质转化的影响。方法采用逆转录-聚合酶链反应(RT-PCR)检测miR-134在20对肾癌组织和786-0细胞中的表达情况;miR-134模拟物转染786-0后,划痕实验和Transwell实验分别检测肾癌细胞迁移和侵袭能力的改变情况,Western blot检测细胞中靶蛋白KRAS及其相关信号通路蛋白表达情况;双荧光素酶报告基因检测miR-134与KRAS 3′-UTR结合情况。结果 MiR-134在20对肾癌组织和786-0细胞中明显低表达(P0.01);miR-134模拟物转染后能够抑制肿瘤细胞侵袭(P0.01)和迁移的能力(P0.05),显著降低肿瘤细胞中KRAS蛋白的水平(P0.05)并抑制RAS/MAPK/ERK通路中关键蛋白p-ERK的表达(P0.05);双荧光素酶报告基因显示miR-134能与KRAS 3′-UTR结合,显著降低荧光值(P0.05)。结论 MiR-134在肾透明细胞癌中显著低表达,能通过靶向抑制KRAS表达调控下游RAS/MAPK/ERK通路活性,阻滞786-0细胞上皮间质转化过程,抑制肿瘤细胞的侵袭和转移。     

High expression of polo-like kinase 1 is associated with the metastasis and recurrence in urothelial carcinoma of bladder

ObjectivesPolo-like kinase 1 (Plk1) has been widely pursued as an oncology target because it is overexpressed in several human tumor types. To investigate whether Plk1 plays a general role in bladder urothelial carcinoma, we examined the expression of Plk1 protein in bladder urothelial carcinoma and cell lines, and analyzed the relationship among Plk1 protein expression, metastasis, and recurrence of urinary bladder urothelial carcinoma.MethodsImmunohistochemistry was used to detect the expression of Plk1 in 120 bladder urothelial carcinoma. Moreover, the expression of Plk1 was analyzed by Western blot in 60 bladder urothelial carcinoma and 21 normal epithelial tissues. MTT assay and flow cytometry and transwell assay were used to examine the proliferative and invasive ability of bladder cancer cells with the treatment of scytonemin (the inhibitor of Plk1). Statistical analysis was used to discuss the association between Plk1 expression and clinicopathologic parameters, tumor metastasis and recurrence, and the proliferative and invasive ability and cell cycle process of the bladder cancer cells.ResultsThere was a significantly higher Plk1expressions in bladder urothelial carcinoma and highly invasive bladder T24 cells than those in bladder normal tissues and the superficial bladder BIU-87 cells. Plk1 expression was positively correlated with histologic grade, pT stage, recurrence, and metastasis. With the increasing concentration of scytonemin, we found that not only the cell proliferation and invasion activity decreased significantly, but also the cell cycle was blocked at G2/M stage.ConclusionPlk1 expression status was closely correlated with important histopathologic characteristics (grades and stages) and the recurrence and metastasis of bladder urothelial carcinomas. Furthermore, Plk1 played an important function on the bladder cancer cells' proliferation by regulating the cancer cell cycle from G1/S to G2/M and probably promoted the invasion and metastasis of bladder cancer.     

Overexpression of microRNA-100 predicts an unfavorable prognosis in renal cell carcinoma

Purpose

Dysregulation of microRNA-100 (miR-100) has been reported to be involved in tumorigenesis and tumor progression of several cancer types. However, its expression patterns in tumors are controversial. The aim of this study was to investigate the expression and clinical significance of miR-100 in renal cell carcinoma (RCC).

Methods

Real-time quantitative PCR was performed to detect the expression levels of miR-100 in 96 paired samples of RCC and adjacent non-cancerous renal tissues. Then, statistical analysis was performed to determine the associations of miR-100 expression with the clinical features and the prognosis of RCCs.

Results

miR-100 expression was significantly higher in RCC tissues compared with adjacent non-cancerous renal tissues (5.3 ± 2.2 vs. 1.9 ± 0.8, P < 0.001). In addition, high miR-100 expression in RCC tissues was significantly associated with advanced tumor T stage (P = 0.005) and grade (P = 0.01), and the presence of metastasis (P = 0.008). Moreover, Kaplan–Meier analysis showed the significant differences in 5-year overall (50.0 vs. 83.3 %, P = 0.006) and tumor-specific survival (58.3 vs. 83.3 %, P = 0.008) for patients with high and low miR-100 expression, respectively. Furthermore, multivariable Cox regression analysis identified high miR-100 expression in RCC tissues as an independent poor prognostic marker of both overall (P = 0.01) and tumor-specific survival (P = 0.02) in patients with RCCs.

Conclusion

Our data offer convincing evidence that miR-100 overexpression strongly associates with advanced tumor progression and unfavorable clinical outcome of patients with RCC. miR-100 expression may be a useful prognostic marker for this disease.     

Overexpression of cyclin-dependent kinase-associated protein phosphatase enhances cell proliferation in renal cancer cells

ObjectiveThe aim of this study was to understand the role of cyclin-dependent kinase-associated protein phosphatase (KAP) in renal cancer cell growth.Materials and methodsRenal cell carcinoma (RCC) tissues from 58 patients receiving surgical resection were included for immunohistochemistry analysis. Additionally, human embryonic kidney (HEK293) cells overexpressing KAP were established for tumorigenicity experiments.ResultsClinicopathologic analysis indicated that poorly differentiated RCCs with a higher histological grade (grade 3/4) were associated with a higher proportion of KAP-positive cells (P < 0.001) as well as cytoplasmic expression of KAP (P < 0.05). HEK293 cells overexpressing KAP had a higher growth rate, greater resistance to TNF-α mediated increment of caspase 3 activity, a shorter cell cycle time, and greater ability of cell invasion. Tumorigenicity experiments showed that KAP-overexpressing cells generated significantly larger xenograft tumors in nude mice compared with mock controls (P = 0.032).ConclusionsKAP expression was associated with poorly differentiated RCCs and overexpression of KAP in renal cells enhanced cell proliferation, resistance to apoptosis, invasive ability, and xenograft tumor formation.     

Expression of vascular endothelial growth factor-C in gastric carcinoma and the effect of its antisense gene transfection on the proliferation of human gastric cancer cell line SGC-7901

PurposeThe aim of this study was to investigate the relationship between the expression of vascular endothelial growth factor-C (VEGF-C) in gastric carcinoma and tumor lymphangiogenesis and to determine the effect of antisense–VEGF-C gene transfection on proliferation.MethodsAdjacent cancer tissues were collected from 72 gastric carcinoma cases and compared with 10 nongastric carcinoma tissues to detect the expression of VEGF-C and its messenger RNA (mRNA) and calculate the density of neonatal lymphatic microvessels. The in vitro–cultured gastric cancer cell line SGC-7901 was transfected with recombinant plasmid pCI-neo-anti VEGF-C. The expression in the transfected cells and the proliferation were determined.ResultsThe positive rate of VEGF-C mRNA in the lymph node metastasis tissues was 85.7% compared with negative controls (20%, P < .05). The density of lymphatic vessels in the metastasis group was 6.65 ± 1.57 compared with the negative group (3.75 ± 1.47, P < .05). Protein and mRNA of VEGF-C were reduced in transfected cells. Proliferation was inhibited as well.ConclusionsVEGF-C can increase the invasiveness of gastric cancer and promote lymphangiogenesis in adjacent tissues. Transfection with antisense VEGF-C can reduce the expression of VEGF-C and inhibit the proliferation. VEGF-C can inhibit the tumor growth and reduce its metastasis and recurrence.     

Hypoxia induces the overexpression of microRNA-21 in pancreatic cancer cells

BackgroundPancreatic cancer cells exist in a hypoxic microenvironment containing numerous factors that impact tumor survival, proliferation, and metastasis. MicroRNAs (miRs) are differentially expressed in cancer but also altered by hypoxia. We hypothesized that hypoxia could induce expression of miR-21, an oncomir in pancreatic cancer cells.Materials and methodsWe examined how hypoxia regulates miR-21 expression in pancreatic cancer cell lines (BxPC-3, AsPC-1) by stem-loop RT-PCR. Chromatin immunoprecipitation assays were used to study how hypoxia alters hypoxia-inducible factor (HIF)-1α binding to the hypoxia response element of miR-21. BxPC-3 and AsPC-1 cells were transfected with a constitutively stable HIF-1α subunit or vector control (pcDNA3.1) to determine the influence of miR-21 in normoxia. The effect of mature miR-21 sense and antisense oligonucleotides on proliferation and apoptosis in hypoxic and normoxic conditions was assessed via WST-1 assay and flow cytometry.ResultsMiR-21 levels increased in all cell lines grown in hypoxic conditions versus normoxia, whereas siRNA targeting HIF-1α reduced miR-21 expression. Hypoxic conditions resulted in direct binding of HIF-1α to the predicted binding site in miR-21. Transfection with a constitutively stable HIF-1α expression plasmid in normoxia resulted in upregulated miR-21, similar to that seen in hypoxia. Cells transfected with antisense constructs targeting miR-21 had reduced proliferation and increased apoptosis in normoxia, whereas miR-21 overexpression abrogated hypoxia-associated reductions in proliferation.ConclusionsMiR-21 is induced by hypoxia in pancreatic cancer cells via HIF-1α upregulation. MiR-21 overexpression allows cells to avoid apoptosis in a hypoxic microenvironment. Inhibition of miR-21 expression may increase cellular susceptibility to hypoxia in pancreatic cancer.     

LncRNA DANCR regulates lymphatic metastasis of bladder cancer via the miR-335/VEGF-C axis

BackgroundSubstantial evidence indicate that long non-coding RNA (lncRNA) and microRNA (miRNA) act as key role in bladder cancer. Differentiation antagonistic ncRNA (DANCR) could be used as a biomarker in the occurrence and development of cancer. This study aims to explore the mechanism of DANCR/miR-335/VEGF-C axis affecting lymphatic metastasis of bladder cancer.MethodsqRT-PCR detects the expression of DANCR in bladder cancer cell lines (SW780, 5637, T24, UM-UC-3) and normal bladder cell lines (SV-HUC-1), and selects T24 cell lines for subsequent experiments. The expression levels of DANCR, miR-335 and VEGF were measured by qRT-PCR, and the dual luciferase reporter gene verified the targeted regulation of DANCR on miR-335 and miR-335 on VEGF. CCK-8, Transwell and Wound healing assay detect the proliferation, invasion and migration ability of bladder cancer cells, Endothelial cell adhesion assay and Western blot further prove the lymphatic metastasis of bladder cancer.ResultsIn this study, DANCR was highly expressed in bladder cancer cell lines. Transfection of si-DANCR significantly inhibits the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells. Dual luciferase assay confirmed that DANCR targets miR-335/VEGF-C. Transfection of miR-335 mimic promotes the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells, overexpression of DANCR eliminates the promotion of miR-335 mimic on bladder cancer cells. Further experiments proved that inhibition of miR-335 and overexpression of VEGF-C can reverse the inhibitory effect of silencing DANCR on bladder cancer cells.ConclusionsIn bladder cancer, DARCR plays an important role, which regulates the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells through the miR-335/VEGF-C molecular axis.