KIF18A knockdown reduces proliferation, migration, invasion and enhances radiosensitivity of esophageal cancer.

Kinesin family member 18A (KIF18A) is significantly overexpressed and is related to the poor prognosis of human cancers. However, the function of KIF18A in esophageal cancer (EC) is still unclear. Human EC cell lines were used in this study. KIF18A expression in human tissues was assessed using Gene Expression Profiling Interactive Analysis 2.0 (GEPIA2). The expressions of KIF18A or IGF2BP3 in EC cells were detected using qRT-PCR or WB. Cells were transfected using si-KIF18A, si-IGF2BP3, and plasmid IGF2BP3. The abilities of proliferation, migration, and invasion were detected by EdU, wound-healing, and transwell assay. The interaction between KIF18A and IGF2BP3 was predicted by starBase v3.0 and studied by RIP and RNA stability assay. Colony formation assay was used to reflect the changes of radiosensitivity in EC cells. KIF18A was upregulated in EC, and KIF18A knockdown inhibited EC cell proliferation, migration, invasion, and radioresistance. The prediction in starBase and RIP assay results showed that KIF18A mRNA could bind to IGF2BP3 protein in EC cells. RNA stability assay was performed to confirm that IGF2BP3 affects mRNA stability of KIF18A. Further studies also showed that IGF2BP3 could positively regulate KIF18A on proliferation, migration, invasion, and radioresistance. Our findings first revealed an oncogenic effect of KIF18A in human EC progression. KIF18A expression was associated with radioresistance of EC cells. The binding relationship between KIF18A and IGF2BP3 might influence the mRNA stability of KIF18A in EC cell lines.

Feedback loop in miR-449b-3p/ADAM17/NF-κB promotes metastasis in nasopharyngeal carcinoma.

An emerging body of evidence has promoted the understanding of the role of microRNAs (miRNAs) in tumorigenesis and progression, but the mediating function of miRNAs in nasopharyngeal carcinoma (NPC) development remains poorly elucidated. In this study, miR-449b-3p was downregulated in NPC specimens (P < .001) and cells (P < .05). Cytological and animal experiments provided evidence that miR-449b-3p inhibited NPC metastasis in vitro and in vivo. Disintegrin and metalloproteinase 17 (ADAM17) was revealed as a direct target of miR-449b-3p. Rescue experiments suggested that the downregulation of ADAM17 in the miR-449b-3p knockdown cells partially reversed the inhibition of cell invasion and migration. Luciferase reporter assay, chromatin immunoprecipitation assay, and Western blot analysis showed that ADAM17 could suppress the promoter activity and expression of miR-449b-3p by inducing NF-κB transcriptional activity. In conclusion, our study provided new insights into the underlying mechanism of the invasion and metastasis of NPC. The novel miR-449b-3p/ADAM17/NF-κB feedback loop could be a target for the clinical treatment of NPC.

Isoliquiritigenin suppresses the proliferation and induced apoptosis via miR-32/LATS2/Wnt in nasopharyngeal carcinoma.

Nasopharyngeal Carcinoma is limited by the various severe side-effects and surgery is rarely performed. Iosliquiritigenin has a series of biological activities, such as antiviral, anti-free radical and antitumor. However, the role and underlying mechanism of isoliquiritigenin in nasopharyngeal carcinoma have not been understood yet. Herein, the results revealed that isoliquiritigenin could inhibit cell proliferation in nasopharyngeal carcinoma cell lines, including C666-1 and CNE2, in both Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'-deoxyuridine (EdU) assay. In addition, isoliquiritigenin promoted nasopharyngeal carcinoma cell apoptosis, with the up-regulations of Bax, Caspase-3 and Caspase-9 and the down-regulation of Bcl-2. Meanwhile, isoliquiritigenin suppressed nasopharyngeal carcinoma cells migration and invasion with the down-regulation of matrix metalloproteinases (MMP)-2 and MMP-9. Furthermore, the expression of miR-32 was up-regulated in the nasopharyngeal carcinoma tissues, while isoliquiritigenin could significantly down-regulate the expression of miR-32. And over-expression of miR-32 promoted the nasopharyngeal carcinoma cells growth, migration and invasion, and suppressed apoptosis. However, isoliquiritigenin treatment dramatically inhibited the effect of miR-32. Besides, luciferase reporter assay confirmed that large tumor suppressor 2 (LATS2) was a direct target of miR-32. And isoliquiritigenin increased the expression of LATS2, while silencing of LATS2 promoted the nasopharyngeal carcinoma cells growth. Moreover, western blotting discovered that isoliquiritigenin inhibited nasopharyngeal carcinoma cells growth via Wnt signaling pathway. Finally, CNE2 cells transplanted xenografts tumor model in nude mice were performed and it suggested that isoliquiritigenin could inhibit the development of xenografts nude mice, along with the decrease of tumor volume and the expression of miR-32 and LATS2. Overall, isoliquiritigenin was confirmed to be a potent anti-nasopharyngeal carcinoma compound both in vitro and in vivo, and accomplished by regulation of miR-32/LATS2/Wnt.

miR-184 Inhibits Tumor Invasion, Migration and Metastasis in Nasopharyngeal Carcinoma by Targeting Notch2.

BACKGROUND/AIMS: A recent study found that dysregulated microRNA-184 (miR-184) is involved in the proliferation and survival of nasopharyngeal carcinoma (NPC). This study aimed to evaluate the detailed mechanisms of invasion, migration and metastasis of NPC cells. METHODS: Quantitative reverse-transcription PCR (qRT-PCR) and Western blot were used to confirm the expression levels of miR-184 and Notch2. NPC cell invasion and migration were subsequently examined using in vitro cell invasion and wound-healing assays, respectively. MicroRNA (miRNA) target gene prediction databases and dual-luciferase reporter assay were adopted to validate the target genes of miR-184. RESULTS: MiR-184 was downregulated in the NPC cell lines. The miR-184 inhibitor increased the number of invading NPC cells, whereas miR-184 mimics inhibited the invasive ability of such cells. The protein level of E-cadherin decreased, whereas those of N-cadherin and vimentin increased in the anti-miR-184 group. This result showed that miR-184 inhibited NPC cell invasion and metastasis by regulating EMT progression. MiRNA target gene prediction databases indicated the potential of Notch2 as a direct target gene of miR-184. Such a notion was then validated by results of dual-luciferase reporter assay. Notably, shRNANotch2 restrained the EMT and partially abrogated the inhibitory effects of miR-184 on EMT progression in NPC cells. CONCLUSION: MiR-184 functions as a tumour-suppressive miRNA targeting Notch2 and inhibits the invasion, migration and metastasis of NPC.

MiRNA-34a reversed TGF-ß-induced epithelial-mesenchymal transition via suppression of SMAD4 in NPC cells.

Epithelial-mesenchymal transition (EMT) is considered a prerequisite for tumor invasion and metastasis in many cancers. However, the mechanisms underlying EMT in nasopharyngeal carcinoma (NPC) is largely unknown. In this study, we found that transforming growth factor-ß (TGF-ß), which reportedly promotes EMT in multiple cancers, can trigger EMT and increase the invasive and migratory capacities of NPC cells. Conversely, the downregulation of SMAD4, a vital member of the canonical TGF-ß pathway, reversed the TGF-ß-induced EMT, invasion, and migration. Further experiments revealed that SMAD4 was the target of miRNA-34a, which was downregulated in NPC tissues and suppressed NPC cell metastasis in vivo. miRNA-34a overexpression also antagonized the TGF-ß-induced EMT progression, invasion, and migration through SMAD4 inhibition. However, the restoration of SMAD4 expression rescued the inhibitory effects of miRNA-34a on tumorigenesis. All these results confirmed that miRNA-34a suppressed the TGF-ß-induced EMT, invasion, and migration of NPC cells by directly targeting SMAD4, which indicated the potential of miR-34a as a therapeutic target against NPC.

MIIP gene expression is associated with radiosensitivity in human nasopharyngeal carcinoma cells.

The present study aims to investigate the radiosensitization effect of the migration and invasion inhibitory protein (MIIP) gene on nasopharyngeal carcinoma (NPC) cells. The MIIP gene was transfected into NPC 5-8F and CNE2 cells. The level of MIIP was analyzed by quantitative reverse transcription-polymerase chain reaction analysis and western blot. The changes in radiosensitivity of the cells were analyzed by colony formation assay. The changes in cell apoptosis and cycle distribution following irradiation were detected by flow cytometry. The expression of BCL2 associated X, apoptosis regulator/B-cell lymphoma 2 was evaluated using western blot. DNA damage was analyzed by counting γ-H2AX foci. The expression levels of γ-H2AX were evaluated by immunofluorescence and western blot. In a previous study by the authors, the results indicated that the expression of MIIP gene evidently increased in MIIP-transfected 5-8F (5-8F OE) and MIIP-transfected CNE2 (CNE2 OE) cells compared with the parental or negative control cells. In the present study, the survival rate of 5-8F OE and CNE2 OE cells markedly decreased following irradiation (0, 2, 4, 6 and 8 Gy) compared with the negative control (5-8F NC and CNE2 NC) and the untreated (5-8F and CNE2) groups. The expression of MIIP was able to increase apoptosis, which resulted in G2/M cell cycle arrest and DNA damage repair was attenuated in 5-8F and CNE2 cells following irradiation as measured by the accumulation of γ-H2AX. It was indicated that MIIP expression is associated with the radiosensitivity of NPC cells and has a significant role in regulating cell radiosensitivity.

MiR-152 functioning as a tumor suppressor that interacts with DNMT1 in nasopharyngeal carcinoma.

BACKGROUND: In recent years, miR-152 has been dysregulated in a variety of tumors and used as a tumor suppressor. Nevertheless, its role in nasopharyngeal carcinoma (NPC) remains unidentified. MATERIALS AND METHODS: Real-time quantitative PCR (polymerase chain reaction) was performed to analyze the expression of miR-152 in NPC cell lines. MiR-152 expression profiles in NPC tissues were obtained from Gene Expression Omnibus (GEO GSE36682). The effect of miR-152 on the invasion and proliferation of NPC cells was determined through cell invasion, wound healing, and cell viability assays. Apoptosis was examined by flow cytometry, and Western blot was performed to measure expression of the target gene. Pyrosequencing was used to detect the methylation level of NPC cells. RESULTS: In this study, miR-152 was downregulated in the NPC tissues and cell lines. When miR-152 was enhanced, the invasion and migration of NPC cells were inhibited. However, miR-152 had no effect on the proliferation of NPC cells. Luciferase reporter gene analysis was performed, and the results showed that DNMT1 (DNA (cytosine-5)-methyltransferase 1) is a direct target of miR-152 in NPC cells. DNMT1 downregulation and miR-152 overexpression both reversed the effects of miR-152 inhibition on the NPC cells. In addition, miR-152 expression increased as a result of the inhibition of the methylation level of miR-152 when DNMT1 expression was downregulated. CONCLUSION: The overexpression of miR-152 inhibited the migration and invasion of NPC cells by targeting DNMT1. Furthermore, DNMT1 regulated miR-152 expression through DNA methylation. Overall, the novel miR-152-DNMT1 regulatory circuit may provide better understanding of the pathogenesis of NPC and new epigenetic therapeutic target in NPC.

MicroRNA-19b-3p regulates nasopharyngeal carcinoma radiosensitivity by targeting TNFAIP3/NF-κB axis.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is among the most common squamous cell carcinoma in South China and Southeast Asia. Radiotherapy is the primary treatment for NPC. However, radioresistance acts as a significant factor that limits the efficacy of radiotherapy for NPC patients. Growing evidence supports that microRNAs (miRNAs) play an important role in radiation response. METHODS: Real-time quantitative PCR was used to analyze the expression of miR-19b-3p in NPC cell lines and NP69. miR-19b-3p expression profiles in NPC tissues were obtained from the Gene Expression Omnibus database. The effect of miR-19b-3p on radiosensitivity was evaluated by cell viability assays, colony formation assays and in vivo experiment. Apoptosis and cell cycle were examined by flow cytometry. Luciferase reporter assay was used to assess the target genes of miR-19b-3p. Expression of target proteins and downstream molecules were analyzed by Western blot. RESULTS: miR-19b-3p was upregulated in NPC and served as an independent predictor for reduced patient survival. Radioresponse assays showed that miR-19b-3p overexpression resulted in decreased sensitivity to irradiation, whereas miR-19b-3p downregulation resulted in increased sensitivity to irradiation in vitro. Moreover, miR-19b-3p decreased the sensitivity of NPC cells to irradiation in vivo. Luciferase reporter assay confirmed that TNFAIP3 was a direct target gene of miR-19b-3p. Knockdown of TNFAIP3 reduced sensitivity to irradiation, whereas upregulation of TNFAIP3 expression reversed the inhibitory effects of miR-19b-3p on NPC cell radiosensitivity. Mechanistically, we found that miR-19b-3p increased NPC cell radioresistance by activating the TNFAIP3/ NF-κB axis. CONCLUSIONS: miR-19b-3p contributes to the radioresistance of NPC by activating the TNFAIP3/ NF-κB axis. miR-19b-3p is a determinant of NPC radioresponse and may serve as a potential therapeutic target in NPC treatment.

Incorporation of alpha-fetoprotein(AFP) into subclassification of BCLC C stage hepatocellular carcinoma according to a 5-year survival analysis based on the SEER database.

PURPOSE: To evaluate the effect of serum alpha-fetoprotein(AFP) on prognosis of patients with hepatocellular carcinoma (HCC) and put forward a proposal to modify BCLC staging system and the recommended treatment of patients with stage C. RESULTS: AFP positive was an independent poor prognostic factor of HCC. Race, pathological grade, T stage, M stage were also regarded to be significant predicted factors for poorer prognosis. When combining AFP status with AJCC stage, patients with A1 disease had a worse prognosis compared with those with A0 disease within each stage. Patients with A1 disease of each T/N stage had a worse prognosis than patients with A0 disease of the respective stage, and the prognosis of patients with A1 disease with lower T stages was worse or similar to that of patients with A0 disease of higher T stages. MATERIALS AND METHODS: We performed a retrospective study of all patients histologically diagnosed HCC from January 1, 2004, through December 31, 2008, from the SEER database. CONCLUSIONS: AFP can be used as a subclassification index to modify the AJCC staging system of HCC. Since BCLC stage is the most widely used staging system, we recommend routine pre-treatment AFP testing as standard of care in HCC and incorporate AFP status into the BCLC staging system to modify the recommended treatment of patients with stage C.