Shuling Ren

MicroRNA-324-3p regulates nasopharyngeal carcinoma radioresistance by directly targeting WNT2B.

PURPOSE Radioresistance severely restricts the clinical treatment of nasopharyngeal carcinoma (NPC). Accumulating evidence demonstrates that aberrant expression of microRNAs (miRNAs) contributes to cancer progression and sensitivity to radiation. Therefore, we aimed to identify miRNAs associated with radioresistance in NPC. METHODS Aberrant miRNA-324-3p expression in NPC CNE-2 cells with radioresistance (CNE-2-Rs), compared to its parental cells, was screened by high-throughput sequencing technology and determined by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) analysis. Bioinformatic analysis was used to predict the downstream target genes of miRNA-324-3p. Then, functional and mechanical analyses of miRNA-324-3p in NPC radioresistance were performed by overexpression and down-regulation of miRNA-324-3p in CNE-2-Rs cells and its parental cells. Finally, the clinical significance of miRNA-324-3p and WNT2B was investigated in NPC tissues. RESULTS Our data reveal that the expression of miRNA-324-3p is significantly decreased in CNE-2-Rs cells compared to its parental cells, and WNT2B is predicted to be the downstream target of miRNA-324-3p. Both overexpression and down-regulation of miRNA-324-3p following irradiation result in radiosensitivity alterations and protein changes of WNT2B signalling pathway in CNE-2-Rs cells and its parental cells. Importantly, down-regulation of miRNA-324-3p and up-regulation of WNT2B are significantly correlated with advanced clinical stages of NPC and this inverse expression pattern is also observed in NPC tissues before and after irradiation. CONCLUSIONS The present study reveals that miRNA-324-3p contributes to the radioresistance of NPC by regulating the WNT2B signalling pathway. Both miRNA-324-3p and WNT2B are potential biomarkers for radioresistance in NPC, which may serve as valuable targets for reversing radioresistance in the management of NPC.

Genome-Wide Analyses of Radioresistance-Associated miRNA Expression Profile in Nasopharyngeal Carcinoma Using Next Generation Deep Sequencing

Background Rapidly growing evidence suggests that microRNAs (miRNAs) are involved in a wide range of cancer malignant behaviours including radioresistance. Therefore, the present study was designed to investigate miRNA expression patterns associated with radioresistance in NPC. Methods The differential expression profiles of miRNAs and mRNAs associated with NPC radioresistance were constructed. The predicted target mRNAs of miRNAs and their enriched signaling pathways were analyzed via biological informatical algorithms. Finally, partial miRNAs and pathways-correlated target mRNAs were validated in two NPC radioreisitant cell models. Results 50 known and 9 novel miRNAs with significant difference were identified, and their target mRNAs were narrowed down to 53 nasopharyngeal-/NPC-specific mRNAs. Subsequent KEGG analyses demonstrated that the 53 mRNAs were enriched in 37 signaling pathways. Further qRT-PCR assays confirmed 3 down-regulated miRNAs (miR-324-3p, miR-93-3p and miR-4501), 3 up-regulated miRNAs (miR-371a-5p, miR-34c-5p and miR-1323) and 2 novel miRNAs. Additionally, corresponding alterations of pathways-correlated target mRNAs were observed including 5 up-regulated mRNAs (ICAM1, WNT2B, MYC, HLA-F and TGF-β1) and 3 down-regulated mRNAs (CDH1, PTENP1 and HSP90AA1). Conclusions Our study provides an overview of miRNA expression profile and the interactions between miRNA and their target mRNAs, which will deepen our understanding of the important roles of miRNAs in NPC radioresistance.

miR-185-3p regulates nasopharyngeal carcinoma radioresistance by targeting WNT2B in vitro.

Aberrant microRNA (miRNA) expression contributes to a series of malignant cancer behaviors, including radioresistance. Our previous study showed differential expression of miR‐185‐3p in post‐radiation nasopharyngeal carcinoma (NPC) cells. To investigate the role of miR‐185‐3p in NPC radioresistance, CNE‐2 and 5‐8F cells were transfected with miR‐185‐3p mimic and miR‐185‐3p inhibitor, respectively. CCK‐8 assay and colony formation experiment confirmed that the expression of miR‐185‐3p affected the radioresistance of NPC cells. A negative correlation between miR‐185‐3p and WNT2B expression was observed in NPC cells and tissues. Luciferase reporter assays confirmed that miR‐185‐3p directly targeted the coding region of WNT2B. Furthermore, we found radioresistance decreased in WNT2B‐silenced NPC cells. Activation of the WNT2B/β‐catenin pathway was accompanied by epithelial–mesenchymal transition biomarker changes in NPC. We concluded that miR‐185‐3p contributed to the radioresistance of NPC via modulation of WNT2B expression in vitro.

Metadherin regulates metastasis of squamous cell carcinoma of the head and neck via AKT signalling pathway-mediated epithelial-mesenchymal transition.

Our recent study suggested that metadherin (MTDH) is overexpressed in laryngeal squamous cell carcinoma. Here, we further investigated its role in promoting metastasis of squamous cell carcinoma of the head and neck (SCCHN). An immunohistochemistry analysis demonstrated that MTDH is elevated and positively correlated with metastasis in 189 primary SCCHN tissues. In vitro experiments demonstrated that MTDH overexpression enhanced the migratory and invasive ability of SCCHN cells. Moreover, MTDH induced epithelial-mesenchymal transition (EMT) by both regulating morphological changes and mediating the expression of the biomolecular makers E-cadherin and vimentin. In addition, MTDH mediated AKT activation, and all of the above effects were nearly completely blocked by the inhibition of AKT. Our results suggested that MTDH might promote the metastasis of SCCHN through AKT signalling pathway mediated-EMT.

Increased expression of metadherin protein predicts worse disease-free and overall survival in laryngeal squamous cell carcinoma.

Metadherin (MTDH) is involved in tumourigenesis and cancer progression in multiple human malignancies. However, the MTDH protein has rarely been reported in laryngeal squamous cell carcinoma (LSCC). The expression pattern of the MTDH protein in 176 primary archival LSCC and 27 corresponding adjacent noncarcinoma specimens was detected by immunohistochemistry and further correlated with clinicopathological parameters. The results demonstrated that 161 (91.48%) primary LSCC samples stained positive for MTDH; however, staining was barely detectable in all adjacent noncarcinoma samples. Moreover, the expression of the MTDH protein was significantly associated with the primary tumour site (p = 0.021), T classification (p = 0.002), clinical stage (I + II/III + IV; p < 0.001), lymph node metastasis (p < 0.001) and postoperational recurrence (p < 0.001). Kaplan‐Meier analysis revealed that MTDH expression was significantly associated with worse disease‐free survival (DFS) and overall survival (OS) rates in patients with LSCC (both p < 0.001). When lymph node metastasis and MTDH expression were considered together, patients with lymph node metastasis and high MTDH expression had both poorer DFS and OS rates than others (both p < 0.001). Finally, multivariate analysis demonstrated that MTDH expression was an independent prognostic factor for both DFS and OS rates in patients with LSCC. Strong MTDH expression was negatively correlated with a canonical epithelial–mesenchymal transition molecule E‐cadherin (p < 0.001) and positively associated with proangiogenic protein vascular endothelial growth factor (p < 0.001). MTDH overexpression was tightly associated with more aggressive tumour behaviour and a poor prognosis, indicating that MTDH is a valuable molecular biomarker for LSCC progression.

Next generation deep sequencing identified a novel lncRNA n375709 associated with paclitaxel resistance in nasopharyngeal carcinoma.

Paclitaxel chemoresistance restricts the therapeutic efficacy and prognosis of patients with nasopharyngeal carcinoma (NPC). Accumulating evidence suggests that aberrant expression of long non-coding RNAs (lncRNAs) contributes to cancer progression. Therefore, we aimed to identify lncRNAs associated with paclitaxel resistance in NPC. First, paclitaxel-resistant CNE-2 cells (CNE-2-Pr) were successfully established and confirmed to be 33.26±8.70 times more resistant than parental CNE-2 cells. Then, differential expression profile of lncRNAs associated with NPC paclitaxel resistance, which contained a total of 2,670 known lncRNAs and 4,820 novel lncRNAs, was constructed via next generation sequencing technology. Our qRT-PCR confirmed that 7 of the top 8 lncRNAs were expressed with the same trend as the prediction, including 4 known lncRNAs (n375709, n377806, n369241 and n335785) and 3 novel lncRNAs (Unigene6646, Unigene6644 and Unigene1654). Our group initially focused on lncRNA n375709, which was the most significantly overexpressed lncRNA of the known lncRNAs. CCK-8 assays demonstrated that further inhibition of lncRNA n375709 increased the paclitaxel sensitivity in NPC 5-8F and 6-10B cells. In conclusion, the present study provided an overview of the expression profiles of lncRNAs correlated with paclitaxel resistance. lncRNA n375709 was identified to be involved in the regulation of NPC paclitaxel resistance.

Increased expression of miR-93 is associated with poor prognosis in head and neck squamous cell carcinoma

MicroRNA-93-5p (miR-93) is a novel oncogenic microRNA (miRNA) and is elevated in diverse human malignancies. Aberrant expression and dysfunction of miR-93 are involved in many types of human tumours. However, the exact role of miR-93 remains unclear in head and neck squamous cell carcinoma (HNSCC). The objective of this study is to determine the expression pattern and clinical significance of miR-93 in HNSCC. MiR-93 expression levels in 103 primary HNSCC tissues and 16 corresponding non-cancerous epithelia were analysed by miRNA in situ hybridisation and correlated with the clinicopathological parameters and patient outcomes. Moreover, the expression of miR-93 was examined in four HNSCC cell lines and 17 pairs of HNSCC tissues and their corresponding adjacent tissues using quantitative real-time PCR (qRT-PCR). The miR-93 levels in HNSCC tissues and cell lines were significantly higher than those in the non-cancerous tissues. Notably, high miR-93 expression was significantly associated with T classification, lymph node metastasis and clinical stage. Kaplan–Meier survival analysis demonstrated that patients with high miR-93 expression had poorer overall survival than patients with low miR-93 expression. Multivariate Cox regression analysis revealed that miR-93 overexpression and lymph node metastasis were independent prognostic factors in patients with HNSCC. This study demonstrated that miR-93 expression was significantly increased in HNSCC tissue samples and cell lines and that miR-93 overexpression was associated with tumour progression, metastasis and poor prognosis in HNSCC patients. These results suggest that miR-93 may play a critical role in the initiation and progression of HNSCC, indicating that miR-93 may be a valuable marker for the prediction of metastasis and prognosis in HNSCC.

Genome-wide analyses of long noncoding RNA expression profiles correlated with radioresistance in nasopharyngeal carcinoma via next-generation deep sequencing

BackgroundRadioresistance is one of the major factors limiting the therapeutic efficacy and prognosis of patients with nasopharyngeal carcinoma (NPC). Accumulating evidence has suggested that aberrant expression of long noncoding RNAs (lncRNAs) contributes to cancer progression. Therefore, here we identified lncRNAs associated with radioresistance in NPC.MethodsThe differential expression profiles of lncRNAs associated with NPC radioresistance were constructed by next-generation deep sequencing by comparing radioresistant NPC cells with their parental cells. LncRNA-related mRNAs were predicted and analyzed using bioinformatics algorithms compared with the mRNA profiles related to radioresistance obtained in our previous study. Several lncRNAs and associated mRNAs were validated in established NPC radioresistant cell models and NPC tissues.ResultsBy comparison between radioresistant CNE-2-Rs and parental CNE-2 cells by next-generation deep sequencing, a total of 781 known lncRNAs and 2054 novel lncRNAs were annotated. The top five upregulated and downregulated known/novel lncRNAs were detected using quantitative real-time reverse transcription-polymerase chain reaction, and 7/10 known lncRNAs and 3/10 novel lncRNAs were demonstrated to have significant differential expression trends that were the same as those predicted by deep sequencing. From the prediction process, 13 pairs of lncRNAs and their associated genes were acquired, and the prediction trends of three pairs were validated in both radioresistant CNE-2-Rs and 6-10B-Rs cell lines, including lncRNA n373932 and SLITRK5, n409627 and PRSS12, and n386034 and RIMKLB. LncRNA n373932 and its related SLITRK5 showed dramatic expression changes in post-irradiation radioresistant cells and a negative expression correlation in NPC tissues (R = −0.595, p < 0.05).ConclusionsOur study provides an overview of the expression profiles of radioresistant lncRNAs and potentially related mRNAs, which will facilitate future investigations into the function of lncRNAs in NPC radioresistance.

Ionizing radiation promotes advanced malignant traits in nasopharyngeal carcinoma via activation of epithelial-mesenchymal transition and the cancer stem cell phenotype

Post-irradiation residual mass and recurrence always suggest a worse prognosis for nasopharyngeal carcinoma (NPC). Our study aimed to investigate the malignant behaviors of post-irradiation residual NPC cells, to identify the potential underlying mechanisms and to search for appropriate bio-targets to overcome this malignancy. Two NPC cell lines were firstly exposed to 60 Gy irradiation, and residual cells were collected. In our previous study, colony formation assay detected the radioresistance of these cells. Here, the CCK-8 assay examined the cell sensitivity to paclitaxel and cisplatin. Wound-healing and Transwell assays were performed to investigate cell motility and invasion capabilities. Inverted phase-contrast microscopy was used to observe and photograph the morphology of cells. Expression levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by western blot assay in NPC cells and tissues. The mRNA levels of cancer stem cell (CSC)-related genes were detected via qRT-PCR. The results revealed that residual NPC cells exhibited enhanced radioresistance and cross-resistance to paclitaxel and cisplatin. Higher capacities of invasion and migration were also observed. An elongated morphology with pseudopodia formation and broadening in the intercellular space was observed in the residual cells. Downregulation of E-cadherin and upregulation of vimentin were detected in the residual NPC cells and tissues. CSC-related Lgr5 and c-myc were significantly upregulated in the CNE-2-Rs and 6-10B-Rs radioresistance cells. Higher proportions of Lgr5+ cells were observed in radioresistant cells via immunofluorescent staining and flow cytometry. In conclusion, our study demonstrated that residual NPC cells had an advanced malignant transition and presented with both EMT and a CSC phenotype. This provides a possible clue and treatment strategy for advanced and residual NPC.

miR-185-3p regulates the invasion and metastasis of nasopharyngeal carcinoma by targeting WNT2B in vitro

MicroRNAs (miRs) have been recognised as important regulators of malignant behaviour in different types of human cancer, including nasopharyngeal carcinoma (NPC). A previous study by our group revealed that miR-185-3p regulates the radioresistance of NPC cells. The present study aimed to investigate the effect of miR-185-3p on NPC invasion and metastasis. Human NPC CNE-2 and 5-8F cell lines were transfected with a miR-185-3p mimic and miR-185-3p inhibitor, respectively, and their effects on the invasion and metastasis of these cells was assessed using a wound healing assay and Matrigel invasion assay. The target gene of miR-185-3p, Wnt family member 2B (WNT2B) was silenced in 5-8F cells using siRNA in order to investigate its function in NPC. Data from the present study demonstrated that the expression of miR-185-3p was the highest in 5-8F and lowest in CNE-2 cells out of a range of NPC cell lines. Following the transfection of miR-185-3p mimic into CNE-2 cells, the wound healing and Matrigel invasion assays indicated that the migration and invasion ability of CNE-2 cells was significantly reduced compared with the negative control group. In addition, the inhibition of miR-185-3p in 5-8F cells significantly increased the capacity for migration and invasion. Furthermore, silencing WNT2B expression resulted in a significant reduction in the invasion and metastasis in 5-8F cells. The inhibition of miR-185-3p, which promotes invasion and metastasis, could be reversed through the silencing of WNT2B in 5-8F cells. The results of the present study indicate that miR-185-3p mediates the invasion and metastasis of NPC by targeting WNT2B in vitro.