Use of recombinant microRNAs as antimetabolites to inhibit human non-small cell lung cancer

During the development of therapeutic microRNAs (miRNAs or miRs), it is essential to define their pharmacological actions. Rather, miRNA research and therapy mainly use miRNA mimics synthesized in vitro. After experimental screening of unique recombinant miRNAs produced in vivo, three lead antiproliferative miRNAs against human NSCLC cells, miR-22-3p, miR-9-5p, and miR-218-5p, were revealed to target folate metabolism by bioinformatic analyses. Recombinant miR-22-3p, miR-9-5p, and miR-218-5p were shown to regulate key folate metabolic enzymes to inhibit folate metabolism and subsequently alter amino acid metabolome in NSCLC A549 and H1975 cells. Isotope tracing studies further confirmed the disruption of one-carbon transfer from serine to folate metabolites by all three miRNAs, inhibition of glucose uptake by miR-22-3p, and reduction of serine biosynthesis from glucose by miR-9-5p and -218-5p in NSCLC cells. With greater activities to interrupt NSCLC cell respiration, glycolysis, and colony formation than miR-9-5p and -218-5p, recombinant miR-22-3p was effective to reduce tumor growth in two NSCLC patient-derived xenograft mouse models without causing any toxicity. These results establish a common antifolate mechanism and differential actions on glucose uptake and metabolism for three lead anticancer miRNAs as well as antitumor efficacy for miR-22-3p nanomedicine, which shall provide insight into developing antimetabolite RNA therapies.

Expression levels of serum miR-126 and miR-9 in patients with wet age-related macular degeneration and their relationship with VEGF and CMT / 中国医师杂志

Objective:To investigate the expression levels of serum miR-126 and miR-9 in patients with wet age-related macular degeneration (wAMD) and their relationship with vascular endothelial growth factor (VEGF) and central macular thickness (CMT).Methods:A total of 73 wAMD patients(observation group) admitted to the ophthalmology department of Taizhou Municipal Hospital from May 2020 to May 2021 and 60 healthy subjects (control group) who underwent physical examination during the same period were selected. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-126 and miR-9 in serum of the two groups. Serum angiogenesis regulatory factors [VEGF, tissue inhibitor of melalloproteinuses-1 (TIMP-1), endostatin (ES), platelet-derived growth factor (PDGF)] were detected by enzyme-linked immunosorbent assay (ELISA), and CMT and intraocular pressure (IOP) were measured. Pearson correlation analysis was performed to determine the correlation between miR-126 and miR-9 and serum angiogenesis regulatory factor levels, CMT and IOP. The diagnostic value of miR-126 and miR-9 in wAMD was analyzed by receiver operating characteristic (ROC) curve.Results:The relative expression level of serum miR-126 in observation group was significantly lower than that in control group ( P<0.05) , while the relative expression level of serum miR-9 was significantly higher than that in control group ( P<0.05). The levels of serum VEGF and PDGF in observation group were significantly higher than those in control group (all P<0.05), while the levels of serum TIMP-1 and ES were significantly lower than those in control group (all P<0.05). CMT and IOP in observation group were significantly higher than those in control group (all P<0.05). The expression level of serum miR-126 in observation group was negatively correlated with serum VEGF, PDGF, CMT and IOP ( r=-0.275, -0.523, -0.302, -0.542, all P<0.05), and was positively correlated with TIMP-1 and ES ( r=0.460, 0.263, all P<0.05). Serum miR-9 expression level was positively correlated with serum VEGF, PDGF, CMT and IOP ( r=0.434, 0.438, 0.396, 0.307, all P<0.05), and was negatively correlated with TIMP-1 and ES ( r=-0.256, -0.310, all P<0.05). The area under curve (AUC) values of serum miR-126 and miR-9 in diagnosing wAMD were 0.713 and 0.847 respectively. Conclusions:The expression level of serum miR-126 is significantly decreased while the expression level of miR-9 is significantly increased in patients with wAMD. miR-126 is negatively correlated with VEGF and CMT, and miR-9 is positively correlated with VEGF and CMT, which may aggravate the disease by promoting the inflammatory response. The detection of expression levels of serum miR-126 and miR-9 is helpful to provide the reference basis for early diagnosis of wAMD and early prevention and treatment.

Diagnostic and prognostic value of serum miR-9-5p and miR-128-3p levels in early-stage acute ischemic stroke

OBJECTIVES: To investigate the clinical utility of serum microRNA levels (miR-9-5p and miR-128-3p) in the diagnosis and prognosis of early-stage acute ischemic stroke (AIS). METHODS: We compared the differences in serum miR-9-5p and miR-128-3p levels between patients with AIS and healthy individuals (controls). The serum levels of miR-9-5p and miR-128-3p were quantified using quantitative real-time PCR, and the association of each miRNA with AIS was determined using receiver operator characteristic curve analysis. The predictive value of these indices in the diagnosis of early-stage AIS was evaluated in conjunction with that of computed tomography findings and neuron-specific enolase levels. The prognosis of patients with AIS was evaluated three months after their discharge from hospital using the modified Rankin scale, which classifies the prognosis as either favorable or poor. Logistic regression analysis was used to analyze the correlation between miR-9-5p and miR-128-3p levels and patient prognosis. RESULTS: The serum levels of miR-9-5p and miR-128-3p were upregulated in patients with AIS relative to those in healthy individuals. A pronounced correlation was identified between serum miR-9-5p and miR-128-3p levels and patient prognosis, with high levels of both miRNAs being associated with poor patient outcomes. CONCLUSION: Assessment of serum miR-9-5p and miR-128-3p levels is important for the early diagnosis and prognosis of AIS.

Effect of microRNA-9-5p targeting MEF2C on biological behaviors of alveolar rhabdomyosarcoma cells / 吉林大学学报(医学版)

Objective: To investigate the effect of microRNA-9-5p (miR-9-5p) targeting the myocyte enhancer factor 2C (MKF2C) on the biologicals behaviors of the alveolar rhabdomyosarcoma (ARMS) cells, and to provide the basis for the molecular diagnosis and targeted therapy of ARMS. Methods: The expression levels of miR-9-5p and MKF2C mRNA in ARMS tissue and cells were detected by qRT-PCR method' the proliferation rate of cells was detected by CCK-8 method, the apoptotic rate was detected by flow cytometry, the numbers of invasion and migration cells were detected by Transwell chamber assay, the luciferase activity in 293T cells was detected by double luciferase reporter gene, and the expression level of MEF2C protein in the cells was detected by Western blotting method. Results: The expression levels of miR-9-5p in ARMS tissue and cells were higher than those in normal skeletal muscle tissue and HSKMC cells ( P

Effect of lncRNA MEG3 on the malignant biological behaviors of cervical cancer standard regimen for advanced colorectal cancer / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To explore the regulatory effect of lncRNA maternal imprinting gene 3 (MEG3) on proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of cervical cancer cells via miR-9-5p/SOCS5 axis. Methods: A total of 20 pairs of cancer and para-cancerous tissue specimens resected from cervical cancer patients in Chongqing Hospital of Traditional Chinese Medicine from January 2017 to June 2019 were collected for this study. Using liposome transfection technology, pcDNA3.1-MEG3,si-MEG3, miR-9-5p mimics, miR-9-5p inhibitor and their control plasmids were transfected into cervical cancer HeLa and SiHa cells respectively to construct overexpression and silence cell model. qPCR was used to detect the expression levels of MEG3, miR-9-5p and SOCS5 in cervical cancer tissues and cell lines. CCK-8 method and Transwell chamber method were used to detect cell proliferation, migration and invasion ability. The expression levels of E-cadherin and vimentin in cells were detected by cellular immunofluorescence experiments. Target genes were predicted through the Online Bioinformatics TargetScan database. Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-9-5p and MEG3, SOCS5, respectively. Results: Compared with para-cancerous tissues and cervical epithelial HcerEpic cells, the expressions of MEG3 and SOCS5 were significantly down-regulated and the expression of miR-9-5p was significantly up-regulated in cervical cancer tissues and cell lines (all P<0.01). TargetScan database analysis and Dual luciferase reporter gene assay confirmed the targeting relationship between miR-9-5p and MEG3 or SOCS5. MEG3 and SOCS5 significantly inhibited while miR-9-5p significantly promoted cell proliferation, migration and invasion ability (all P<0.01). MEG3 and SOCS5 promoted E-cadherin expression and inhibited vimentin expression, while miR-9-5p inhibited E-cadherin expression and promoted vimentin expression (P<0.05 or P<0.01). Conclusion: lncRNA MEG3 regulates proliferation, migration, invasion and EMT of cervical cancer cells via miR-9-5p/SOCS5 axis.

miR-9 regulates the malignant biological behaviors of small cell lung cancer by targeting zinc finger E-box binding homeobox 2 and its possible mechanism / 中国肿瘤生物治疗杂志

@#[Abstract] Objective：To explore the regulatory effect of miR-9 on biological behaviors of small cell lung cancer (SCLC) cells by targeting zinc finger E-box binding homeobox 2 (ZEB2), and to analyze the role of miR-9 in SCLC and its possible mechanism. Methods: qPCR, WB and immunohistochemistry methods were used to detect the mRNA and protein expressions of ZEB2 in cancer tissues and corresponding adjacent tissues of 67 SCLC patients who received surgical treatment at the Department of Oncology, Fourth Hospital of Hebei Medical University from February 2018 to November 2019. TargetScan was used to predict the potential target gene of miR-9, which was later verified by Dual luciferase reporter gene assay, qPCR and WB methods. CCK-8 method, Flow cytometry and Transwell experiment were used to detect the effect of miR-9 and ZEB2 over-expression on the biological behaviors of NCI-H446 cells, and WB was used to detect the protein expressions of E-cadherin, N-cadherin and Vimentin in cells. NCI-H446 cells overexpressing miR-9 were used to construct SCLC nude mouse xenograft model, and the effect of miR-9 on the growth of xenografts was observed. Results: The mRNA and protein expression levels of ZEB2 in SCLC tissues were significantly higher than those in adjacent tissues (P<0.01). There is a potential binding site on the 3' UTR of ZEB2 to bind with miR-9. Compared with the control group, the mRNA and protein expression levels of ZEB2 in NCI-H446 cells of the miR-9 over-expression group were significantly reduced (P<0.01); the proliferation, migration and invasion abilities of NCI-H446 cells were significantly suppressed (P<0.05 or P<0.01), and the expression of EMT protein was reduced; However, simultaneous over-expression of ZEB2 could reverse above effects. In in vivo experiments, the size and weight of transplanted tumors in the miR-9 over-expression group were significantly lower than those in the control group (P<0.05 or P<0.01). The expression of ZEB2 protein in the tumor tissues of nude mice in the miR-9 overexpression group was significantly lower than that in the control group (P<0.01). Conclusion: miR-9 can inhibit the biological behaviors of SCLC cells and the growth of NCI-H446 transplanted tumors in nude mice by targeting and regulating ZEB2.

Regulatory effect and mechanism of miR-9-5p on malignant biological behaviors of breast cancer / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To explore the role of miR-9-5p in the biological behaviors of breast cancer cells and its possible regulatory mechanism. Methods: online OncomiR database was used to analyze the differential expression of miR-9-5p in breast cancer tissues and normal breast tissues. qPCR was used to detect the miR-9-5p expression in breast cancer cell lines and normal breast cells. Based on target gene prediction software TargetScan, ONECUT2 (one cut homeobox 2) was predicted to be the target gene of miR-9-5p. Dual luciferase reporter system was used to validate the relationship between miR-9-5p and its promising target gene ONECUT2. MDA-231 cells were transfected with miR-9-5p mimic, ONECUT2 siRNAs as well as the corresponding control sequences. The protein and mRNA levels of stemness-associated gene NOTCH1, NANOG and SOX9 (SRY (sex-determing region of Y chromosome) -Box transcription Factor 9) were detected by WB and qPCR. The effect of transfection on proliferation, apoptosis and chemo-resistance of cells was detected by BrdU method, Annexin Ⅴ method and MTS Assay, respectively. The ALDEFLUOR experiment was used to detect the effects of miR-9-5p and its target gene ONECUT2 on tumor stemness. NSG mouse breast cancer chemotherapy model was established, and the in vivo experiments further verified the effect of ONECUT2 on tumor malignant biological behaviors, such as cell stemness and chemo-resistance. Results: miR-9-5p was highly expressed in breast cancer tissues (P=0.007) and breast cancer MDA-231 cell line (P=0.0005), and was positively correlated with the poor prognosis of breast cancer patients (P=0.0016). Compared to control group, miR-9-5p could target and negatively regulate ONECUT2 expression, further increase ALDH+ cell population (P=0.0006), as well as increase the expressions of stemness-associated genes NOTCH1, NANOG and SOX9. Besides, miR-9-5p increased the anti-apoptosis ability (P=0.0003) and chemo-resistance of MDA-231 cells; however, miR-9-5p/ONECUT2 exerted no significant effect on the proliferation ability of MDA-231 cells (P>0.05). Compared with the control group, the volume of xenografts in mice of MDA-231/ONECUT2 group after DTX chemotherapy was significantly lower than that in the control group (P<0.05), and the protein expressions of NOTCH1, SOX9 and the mRNA expression of ABC transporter in the transplanted tumor tissues were significantly reduced (P<0.05 or P<0.01). Conclusions: The highly expressed miR-9-5p in breast cancer induces tumor stemness and anti-apoptotic ability by targeting ONECUT2 and enhances its resistance to chemotherapy.

lncRNA MEG3 inhibits the growth of hepatocellular carcinoma cells by sponging miR-9-5p to upregulate SOX11

The long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3), a tumor suppressor, is critical for the carcinogenesis and progression of different cancers, including hepatocellular carcinoma (HCC). To date, the roles of lncRNA MEG3 in HCC are not well illustrated. Therefore, this study used western blot and qRT-PCR to evaluate the expression of MEG3, miR-9-5p, and Sex determining Region Y-related HMG-box 11 (SOX11) in HCC tissues and cell lines. RNA pull-down and luciferase reporter assay were used to evaluate these molecular interactions. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and flow cytometry detected the viability and apoptosis of HCC cells, respectively. The results showed that MEG3 and SOX11 were poorly expressed but miR-9-5p was highly expressed in HCC. The expression levels of these molecules suggested a negative correlation between MEG3 and miR-9-5p and a positive correlation with SOX11, confirmed by Pearson's correlation analysis and biology experiments. Furthermore, MEG3 could combine with miR-9-5p, and SOX11 was a direct target of miR-9-5p. Moreover, MEG3 over-expression promoted cell apoptosis and growth inhibition in HCC cells through sponging miR-9-5p to up-regulate SOX11. Therefore, the interactions among MEG3, miR-9-5p, and SOX11 might offer a novel insight for understanding HCC pathogeny and provide potential diagnostic markers and therapeutic targets for HCC.

Propofol inhibits invasion and growth of ovarian cancer cells via regulating miR-9/NF-kappaB signal

Propofol is one of the most commonly used intravenous anesthetic agents during cancer resection surgery. A previous study has found that propofol can inhibit invasion and induce apoptosis of ovarian cancer cells. However, the underlying mechanisms are not known. miR-9 has been reported to be little expressed in ovarian cancer cells, which has been related to a poor prognosis in patients with ovarian cancer. Studies have also demonstrated that propofol could induce microRNAs expression and suppress NF-κB activation in some situations. In the present study, we assessed whether propofol inhibits invasion and induces apoptosis of ovarian cancer cells by miR-9/NF-κB signaling. Ovarian cancer ES-2 cells were transfected with anti-miR-9 or p65 cDNA or p65 siRNA for 24 h, after which the cells were treated with different concentrations of propofol (1, 5, and 10 μg/mL) for 24 h. Cell growth and apoptosis were detected using MTT assay and flow cytometry analysis. Cell migration and invasion were detected using Transwell and Wound-healing assay. Western blot and electrophoretic mobility shift assay were used to detect different protein expression and NF-κB activity. Propofol inhibited cell growth and invasion, and induced cell apoptosis in a dose-dependent manner, which was accompanied by miR-9 activation and NF-κB inactivation. Knockdown of miR-9 abrogated propofol-induced NF-κB activation and MMP-9 expression, reversed propofol-induced cell death and invasion of ES-2 cells. Knockdown of p65 inhibited NF-κB activation rescued the miR-9-induced down-regulation of MMP-9. In addition, overexpression of p65 by p65 cDNA transfection increased propofol-induced NF-κB activation and reversed propofol-induced down-regulation of MMP-9. Propofol upregulates miR-9 expression and inhibits NF-κB activation and its downstream MMP-9 expression, leading to the inhibition of cell growth and invasion of ES-2 cells.

Expressions of miR-9 and NRP1 in human NSCLC tissue and adj acent carcinoma tissue and their clinical significances / 吉林大学学报(医学版)

Objective:To detect the expression levels of neuropilin1 (NRP1)mRNA and miR-9 in non-small cell lung cancer (NSCLC)tissue samples, and to explore the correlations between the expressions of NRP1 mRNA, miR-9 and the clinicopathological characteristics of the patients with NSCLC.Methods:Informed consent was obtained from each patient before surgery.The tissue samples including 45 NSCLC tissue ,45 adjacent carcinoma tissue and 45 normal lung tissue were collected from China-Japan Union Hospital of Jilin University from 2010 to 2011.qRT-PCR was used to detect the expression levels of NRP1 mRNA and miR-9 in three kinds of lung tissue, and the correlation between the expressions of NRP1 mRNA, miR-9 and clinicopathological characteristics of the patients with NSCLC was analyzed.Results:Compared with normal tissue,the expression level of NRP1 mRNA in adjacent carcinoma tissue had no change (P>0.05),but the expression level of NRP1 mRNA in non-small cell lung cancer tissue was significantly decreased (P0.05),but the expression level of miR-9 in non-small cell lung cancer tissue was significantly increased (P 0.05),but was correlated to the sex (P<0.05). Conclusion:The expression level of miR-9 is up-regulated and the expression level of NRP1 mRNA is down-regulated significantly in non-small cell lung cancer tissue. The detection of the expression level of NRP1 mRNA contributes to j udge the histological subtype and lymph node metastasis of NSCLC.

Function and Regulation of miR-9-3 in Chronic Lymphocytic Leukemia / 现代检验医学杂志

Objective To investigate the role and regulatory mechanism of micro RNA-9-3 (miR-9-3)in the pathogenesis of chronic lymphocytic leukemia.Methods Using the methylation specific PCR (MSP)technology to detect 8 cases of normal bone marrow tissue and peripheral blood,78 cases of bone marrow tissue came from the chronic lymphocytic leukemia pateints newly diagnosed and the methylation level of 7 kinds of leukemia cell line.Used Western blot to detected the NF-kappa B1 signal transduction pathway activation levels of methylation positive leukemia cell line.Results The miR-9-3 of normal control group were in the negative methylation status.Only I83-E95 and WAC3CD5+ were in positive methylation status in seven kinds of leukemia cell line (the positive of MSP was 28.6%);65 cases occurred miR-9-3 methylated in 78 of chronic lymphocytic leukemia patients (the positive of MSP was 83%).I83-E95 and miR-9-3 cells of WAC3CD5+ were in the methylation state when treatment with 5-nitrogen-2’-deoxidization cytidine (5-Aza2’Dc).Conclusion The abnormal methylation of miR-9-3 were usually seenin chronic lymphocytic leukemia,it could lead to abnormal hyperplasis in cancer cells.The methylation of miR-9-3 could inhibit the activation of NF-kappa B1 signal pathway suggested that it could sup-press the apoptosis of cancer cells through this pathways to trogered the progression of disease.The inhibitor of methylation could be induced the demethylation of leukemia cell lines,so it is possible that miR-9-3 maight be a new gene targets for the treatment of chronic lymphocytic leukemia.

Inhibition of miR-9 expression suppresses proliferation, invasion and mi-gration of nasopharyngeal carcinoma cells / 中国病理生理杂志

AIM:To investigate the effects of down-regulated miR-9 expression on the proliferation , invasion and migration of nasopharyngeal carcinoma (NPC) cells.METHODS:Human NPC CNE1 and CNE2 cells were transfect-ed with the inhibitor of miR-9 by Lipofectamine to down-regulate the expression of miR-9, and the cells transfected with an inhibitor control were also set up .The cell proliferation and cell cycle were evaluated by CCK-8 assay and flow cytometry . The cell invasion and migration abilities were detected by Transwell invasion and wound -healing assays .Immunoblotting was applied to analyze the levels of the proteins .RESULTS:Compared with control group , inhibition of miR-9 expression in the NPC cells by transfection of the miR-9 inhibitor significantly decreased the proliferation ability (P<0.05).The per-centages of the cells in G 0/G1 phase [ CNE2: ( 57.96 ±1.39 )% vs ( 47.93 ±1.76 )%, P<0.05; CNE1: ( 51.24 ± 0.88)%vs (48.29 ±0.39)%, P<0.05] were significantly increased.The migration distances [CNE2: (186.50 ± 7.94)μm vs (247.56 ±15.56)μm, P<0.05;CNE1:(139.06 ±16.73)μm vs (230.66 ±14.27)μm, P<0.01] and the invasion ability of the CNE2 cells (43.00 ±3.17 vs 65.80 ±5.20, P<0.01) were also significantly inhibited .Moreo-ver, the tumor cells transfected with the inhibitors produced lower β-catenin.CONCLUSION:Inhibition of miR-9 expres-sion suppresses the proliferation , invasion and migration of nasopharyngeal carcinoma cells .

Target regulation of miR-9 to the expression of NRP1 and its role in radiation effects / 中华放射医学与防护杂志

Objective To explore the effect of miR-9 on the expression of NRP1 and its radiation effects in A549 cells.Methods Bioinformatics was used to analyze the potential binding sites of has-miR-9 and NRP1-3'UTR.The miR-9 sequence was inserted into pcDNA-DEST-47 plasmid to construct the eukaryotic expression vector (pcDNA-DEST-miR-9) and to construct the NRP1 gene 3'UTR luciferase reporter plasmid (pEZX-MT05) at the same time.They were simultaneously transferred into A549 cells for analysis of the regulatory effect of miR-9 on the expression of NRP1.Meanwhile miR-29b was used as a negative control to observe whether or not NRP1 gene was a target of miR-9.After 10 Gy irradiation,the expression of NRP1,and the inhibitory effect of miR-9 on it was confirmed by Western blot assay.The expression of miR-9 was detected by real-time PCR.Results It was found that miR-9 reduced the luciferase activity of NRP1-3'UTR wild plasmid (t =3.906,P ＜ 0.05) but not NRP1-3' UTR mutant plasmid.This luciferase activity was not inhibited by other types of miRNA (miR-29b).The expression of NRP1 protein in A549 cells was decreased after the cells were transfected with miR-9 mimic.After irradiation with dose of 10 Gy,the expression of miR-9 were decreased (t =37.319,P ＜ 0.05) and the expression of NRP1 protein were increased.Conclusions miR-9 regulates the expression of NRP1 by targeting 3'UTR site of NRP1 gene in A549 cells.

Expression of miR-9 in H/RS cells and its regulation on target PRDM1 / 白血病·淋巴瘤

Objective To explore the expression of miR-9 in H/RS cells and its regulation on target PRDM1.Methods miR-9 expression in normal CD19+ B-cell subsets and eight lymphoma cell lines was detected by fluorescence quantitative RT-PCR and in situ hybridization (ISH),for quantification and location,respectively.Chemically synthesizcd antisense oligonucleotide of miR-9 was transiently transfected into L428 for its silence,and the PRDM1 expression was tested.Results Fluorescence quantitative RT-PCR showed that the expression of miR-9 in L428 cells was marked higher than that of normal CD19+ B-cell subsets and other lymphoma cell lines (the expression of miR-9 in L428 cells was 47-fold of OCI-Ly1,50-fold of Raji cells,7-fold of EBV+ immortalized B cell line,and 6-fold of ALCL cell line).ISH indicated that miR-9 located in cytoplasm,it was a diffuse and strong positive in L428,scattered and weak in DLBCL and Burkitt' s lymphoma cell lines,while negative in KARPAS-299 or Jurkat cell lines.Transient down-regulation of miR-9 in L428 leded to the increase of PRDMI protein.Conclusion miR-9 plays the role of cancer gene in cHL,and may exert a potential function in regulating terminal B cell differentiation through a post transcription regulation of PRDM1 gene.

miR-9 and let-7g enhance the sensitivity to ionizing radiation by suppression of NFkappaB1

The activation of nuclear factor-kappa B1 (NFkappaB1) in cancer cells may confer resistance to ionizing radiation (IR). To enhance the therapeutic efficiency of IR in lung cancer, we screened for microRNAs (miRNAs) that suppress NFkappaB1 and observed their effects on radiosensitivity in a human lung cancer cell line. From time series data of miRNA expression in gamma-irradiated H1299 human lung cancer cells, we found that the expression of miR-9 was inversely correlated with that of NFkappaB1. Overexpression of miR-9 down-regulated the level of NFkappaB1 in H1299 cells, and the surviving fraction of gamma-irradiated cells was decreased. Interestingly, let-7g also suppressed the expression of NFkappaB1, although there was no canonical target site for let-7g in the NFkappaB1 3' untranslated region. From these results, we conclude that the expression of miR-9 and let-7g could enhance the efficiency of radiotherapy for lung cancer treatment through the inhibition of NFkappaB1.