MicroRNA-577/EIF5A2 axis suppressed the proliferation of DDP-resistant nasopharyngeal carcinoma cells by blocking TGF-ß signaling pathway.

Diaminodichoroplatinum (DDP) resistance of tumor cells is the culprit of nasopharyngeal carcinoma (NPC) treatment failure. MicroRNA-577 is lowly expressed in NPC tissues, but relevant mechanism is poorly studied. Therefore, this study investigated the role of microRNA-577 in NPC cells with DDP resistance and its mechanism. DDP-resistant NPC cells were established by treatment with DDP at increased concentrations (2, 4, 6, 8, or 10 µg/mL). MicroRNA-577 and EIF5A2 mRNA expressions were detected by qRT-PCR. Cell biological behaviors were assessed via cell function experiments. Expressions of epithelial mesenchymal transformation (EMT)-related proteins were quantified by western blot. The targeting relationship between eukaryotic translation initiation factor 5A2 (EIF5A2) and microRNA-577 was verified through dual-luciferase reporter assay. The tumor volume and weight were measured after subcutaneous tumorigenesis in mice. As observed from the results, microRNA-577 expression was reduced in NPC cells and DDP-resistant NPC cells. Up-regulated microRNA-577 suppressed the malignant behaviors and EMT of DDP-resistant NPC cells, and facilitated cell apoptosis. MicroRNA-577 targeted EIF5A2, and overexpressed EIF5A2 reversed the above effects of up-regulated microRNA-577 on DDP-resistant NPC cells. Besides, EIF5A2 positively regulated TGF-ß signaling pathway, and TGF-ß treatment offset the promoting effects of EIF5A2 silencing on apoptosis of DDP-resistant NPC cells. Up-regulated microRNA-577 suppressed the proliferation of DDP-resistant NPC cells, and down-regulated the levels of EIF5A2 and TGF-ß as well as EMT in vivo. Collectively, microRNA-577/EIF5A2 axis hinders the EMT progression through the blockage of TGF-ß signaling pathway, so as to inhibit the proliferation of DDP-resistant NPC.

Exosomal miR-18a-5p promotes EMT and metastasis of NPC cells via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

This study investigated the underlying mechanism of miR-18a-5p regulating the proliferation, invasion, and metastasis of nasopharyngeal carcinoma (NPC) cells in vitro and in vivo to indicate the pathogenesis of NPC. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was utilized to determine miR-18a-5p expression level in NPC tissues and cell lines. Besides, 2,5-diphenyl-2 H-tetrazolium bromide (MTT) and colony formation assays were employed to detect the effect of miR-18a-5p expression level on NPC cell proliferation. Wound healing and Transwell assays were utilized to detect the effect of miR-18a-5p on NPC cell invasion and migration. The expression levels of epithelial-mesenchymal transition (EMT)-related proteins (Vimentin, N-cadherin, and E-cadherin) were identified by Western blot assay. After collecting exosomes from CNE-2 cells, it was found that exosomal miR-18a-5p secreted from NPC cells promoted NPC cell proliferation, migration, invasion, and EMT, whereas inhibition of miR-18a-5p expression level led to the opposite results. The dual-luciferase reporter assay showed that BTG anti-proliferation factor 3 (BTG3) was the target gene of miR-18a-5p, and BTG3 could overturn the effect of miR-18a-5p on NPC cells. Xenograft mouse model of NPC nude mice showed that miR-18a-5p promoted NPC growth and metastasis in vivo. This study revealed that exosomal miR-18a-5p derived from NPC cells promoted angiogenesis via targeting BTG3 and activating the Wnt/ß-catenin signaling pathway.

Identification and validation of an ECM organization-related gene signature as a prognostic biomarker and therapeutic target for glioma patients.

BACKGROUND: Glioma is the most common and devastating form of malignant brain tumor, with a poor prognosis. Extracellular matrix (ECM) organization is a crucial determinant of glioma invasion and progression. However, the clinical significance of ECM organization in glioma patients remains unclear. OBJECTIVE: To evaluate the prognostic value of ECM organization-related genes in glioma patients and identify potential therapeutic targets. METHODS: Bulk RNA-sequencing and corresponding clinical data for patients with glioma were downloaded from TCGA and GEO databases. Differentially expressed ECM organization genes were identified, and an ECM organization-related gene prognostic model was then generated. Furthermore, the prognostic model has validated in the Chinese Glioma Genome Atlas (CGGA) dataset. The role of TIMP1 in glioma cells by using various functional assays revealed their underlying mechanism in vitro. RESULTS: We identified and validated a nine-gene signature (TIMP1, SERPINE1, PTX3, POSTN, PLOD3, PDPN, LOXL1, ITGA2, and COL8A1) related to ECM organization as a robust prognostic biomarker for glioma. Time-dependent ROC curve analysis confirmed the specificity and sensitivity of the signature. The signature was closely related to an immunosuppressive phenotype, and its combination with immune checkpoints served as a good predictor for patients' clinical outcomes. Notably, single-cell RNA sequencing analysis revealed high expression of TIMP1 in astrocytes and oligodendrocyte progenitor cells in glioma patients. Last, we show that TIMP1 regulates glioma cell growth and invasion via the AKT/GSK3ß signaling pathway. CONCLUSION: This study provides promising insights into predicting glioma prognosis and identifying a potential therapeutic target in TIMP1.

Molecular mechanism of FBXW7-mediated ubiquitination modification in nasopharyngeal carcinoma cell proliferation in vitro and in vivo.

OBJECTIVES: Nasopharyngeal carcinoma (NPC) is a type of keratinizing squamous cell malignancy. Ubiquitination, a common protein posttranslational modification, participates in cancer development. This study sought to investigate the mechanism of F-box and WD repeat domain containing 7 (FBXW7) in NPC cell proliferation in vivo and in vitro. METHODS: FBXW7, Homeobox A10 (HOXA10), and bone morphogenetic protein-2 (BMP2) expression levels in NPC tissues and cells were detected by RT-qPCR and Western blotting. Cell proliferation was assessed by cell counting kit-8 and colony formation assays. The binding of FBXW7 to HOXA10 and HOXA10 ubiquitination level were detected via co-immunoprecipitation and ubiquitination assay. Cells were treated with MG132 (the proteasome inhibitor), followed by the determination of HOXA10 ubiquitination and protein levels. The binding of HOXA10 to BMP2 was testified via dual-luciferase and chromatin immunoprecipitation assays. Collaborative experiments were performed to confirm the role of HOXA10 or BMP2 in FBXW7-mediated NPC cell proliferation. Xenograft tumor assay was performed to confirm the role of FBXW7/HOXA10/BMP2 in vivo. RESULTS: FBXW7 was under-expressed, while HOXA10 and BMP2 were up-expressed in NPC tissues and cells. FBXW7 overexpression restricted NPC cell proliferation. Mechanically, FBXW7 bound to HOXA10 to promote ubiquitination-based degradation of HOXA10 and further reduced the binding of HOXA10 to the BMP2 promoter and inhibited BMP2 transcription. Overexpression of HOXA10 or BMP2 attenuated the role of FBXW7 overexpression in inhibiting NPC cell proliferation. FBXW7 overexpression reduced Ki67 positive rate and repressed tumor growth. CONCLUSION: FBXW7 overexpression promoted HOXA10 ubiquitination-based degradation and further inhibited BMP2 transcription, consequently restricting NPC cell proliferation in vitro and in vivo.

LncRNA GAS5/miR­4465 axis regulates the malignant potential of nasopharyngeal carcinoma by targeting COX2.

Nasopharyngeal carcinoma is a malignant tumor that not only negatively affects the physical and mental health but also the quality of life of the patients. Growth arrest-specific transcript 5 (GAS5) is a common long-chain non-coding RNA (lncRNA) that has been reported to participate in the development of various cancers. However, the biological functions of lncRNA GAS5 in the occurrence and development of nasopharyngeal carcinoma are elusive. The expression of lncRNA GAS5 in nasopharyngeal carcinoma and normal samples were analyzed. Bioinformatic tool was utilized to predict the potential function of lncRNA in nasopharyngeal carcinoma. Transplanted mice were used for in vivo experiments. We observed that the expression of lncRNA GAS5 was upregulated in nasopharyngeal carcinoma tissues and cells. Down-regulation of lncRNA GAS5 inhibited the proliferation and promoted apoptosis of nasopharyngeal carcinoma cells. The expression of miR-4465 was down regulated in nasopharyngeal carcinoma tissues and cells. LncRNA GAS5 could directly bind to miR-4465 and regulated the expression of miR-4465. It was further confirmed that miR-4465 could directly bind with COX2 and inhibit the expression of COX2. Down-regulation of lncRNA GAS5 suppressed tumor growth, promoted the expression levels of miR-18a-5p and suppressed the expression of COX2 in vivo. LncRNA GAS5 regulated nasopharyngeal carcinoma malignancy through targeting miR-4465 and modulating COX2. The GAS5/miR-4465/COX2 axis in nasopharyngeal carcinoma pathogenesis was confirmed, which would provide a new therapeutic target for nasopharyngeal carcinoma.

Circular RNA CDR1as sponges miR-7-5p to enhance E2F3 stability and promote the growth of nasopharyngeal carcinoma.

BACKGROUND: Circular RNA (circRNA) CDR1as plays an important role in the occurrence and development of human tumors. The purpose of this study is to investigate the molecular mechanism of circRNA CDR1as in the development of nasopharyngeal carcinoma (NPC). METHODS: The mRNA expressions of circRNA CDR1as, miR-7-5p, and E2F3 were detected by qRT-PCR. The effects of circRNA CDR1as, miR-7-5p, and E2F3 on NPC cells were investigated using cell counting kit-8 (CCK8) method, colony formation assay, and representative metabolite assay. The molecular mechanism of circRNA CDR1 in NPC was studied by bioinformatics and luciferase reporter assay. In addition, the biological activity of circRNA CDR1as was also investigated in NPC xenograft tumor mice model. RESULTS: The results showed that the circRNA CDR1as expression was significantly up-regulated in NPC tissues by comparison with non-tumor NPE tissues (p < 0.01), suggesting that circRNA CDR1as was associated with poor prognosis in NPC patients. Moreover, circRNA CDR1as could up-regulate E2F3 expression by binding miR-7-5p, and promote the growth and glucose metabolism of NPC cells. Meanwhile, circRNA CDR1as could promote NPC progression through the negative regulation of miR-7-5p in the xenograft tumor model. CONCLUSION: CircRNA CDR1as promoted the occurrence and development of NPCs by successively up-regulating the expression of miR-7-5p and E2F3, suggesting CircRNA CDR1as as a potential target for the treatment of NPC patients.Trial registration The study was approved by the cancer center's institutional research ethics committee on Oct 18, 2008 (2008GZ2847462).

A systematic review and meta-analysis: Association between MGMT hypermethylation and the clinicopathological characteristics of non-small-cell lung carcinoma.

The relationship between O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and clinicopathological characteristics of non-small-cell lung carcinoma (NSCLC) has remained controversial and unclear. Therefore, in this study we have undertaken a systematic review and meta-analysis of relevant studies to quantitatively investigate this association. We identified 30 eligible studies investigating 2714 NSCLC patients. The relationship between MGMT hypermethylation and NSCLC was identified based on 20 studies, including 1539 NSCLC patient tissue and 1052 normal and adjacent tissue samples (OR = 4.60, 95% CI = 3.46~6.11, p < 0.00001). MGMT methylation varied with ethnicity (caucasian: OR = 4.56, 95% CI = 2.63~7.92, p < 0.00001; asian: OR = 5.18, 95% CI = 2.03~13.22, p = 0.0006) and control style (autologous: OR = 4.44, 95% CI = 3.32~5.92, p < 0.00001; heterogeneous: OR = 9.05, 95% CI = 1.79~45.71, p = 0.008). In addition, MGMT methylation was observed to be specifically associated with NSCLC clinical stage, and not with age, sex, smoking, pathological types, and differentiation status. Also MGMT methylation did not impact NSCLC patients survival (HR = 1.32, 95% CI = 0.77~2.28, p = 0.31). Our study provided clear evidence about the association of MGMT hypermethylation with increased risk of NSCLC.

Phase II clinical trial of h-R3 combined with radiotherapy in locally advanced nasopharyngeal carcinoma.

PURPOSE: The purpose of this study was to evaluate the short- and long-term efficacy and toxicity of the humanized anti-epidermal growth factor receptor (EGFR) monoclonal antibody h-R3 when combined with radiotherapy for the treatment of locally advanced nasopharyngeal carcinoma (NPC). METHODS: 35 patients with stage III-IVb NPC with moderate- or strong-intensity EGFR expression were randomly divided into either a radiotherapy alone group or a group receiving radiotherapy combined with h-R3. RESULTS: The complete remission (CR) rates of the combination group at three time points were significantly higher (p<0.05) than those of the radiotherapy alone group. Overall survival, 3-year local control rate, and no distant metastasis rate did not differ between the two groups. No severe toxicity was noticed. CONCLUSION: h-R3 is an agent with good safety profile which could help enhance the radiation antitumor effect in locally advanced NPC, but it did not seem to exhibit significant long-term efficacy.

[Phase II clinical trial of h-R3 combined radiotherapy for locoregionally advanced nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies are easily to produce human anti-murine antibody response at present clinical use. This may influence therapeutic effect. This study was to evaluate the short-term and long-term efficacy and toxicity of the humanized anti-EGFR monoclonal antibody h-R3 in combination with radiotherapy for locoregionally advanced nasopharyngeal carcinoma (NPC). METHODS: Patients with newly diagnosed stage III-IVb (UICC 1997) NPC, who had moderate or strong EGFR expression, were randomized into radiotherapy alone group or radiotherapy combined h-R3 group. Similar dosage and technique of radiotherapy was administered in both groups. The combination group received weekly intravenous infusion of 100 mg h-R3 during radiotherapy. The short-term efficacy was evaluated according to WHO criteria. The survival was analyzed by Kaplan-Meier method. RESULTS: A total of 35 patients were enrolled, 17 in radiotherapy alone group and 18 in combination group. During treatment, only 1 patient withdrew from the combination group. The overall complete remission (CR) rates at the end of treatment, 5 and 17 weeks after treatment were significantly higher in combination group than in radiotherapy alone group (72.2% vs. 35.3%, 83.3% vs. 41.2%, and 83.3% vs. 47.1%, P<0.05). Median follow-up time was 31.9 months (range, 4.2-40.7 months). No significant differences in 3-year locoregional control, distant metastasis-free survival and overall survival rates between the 2 groups were found. Except for 1 patient suffered from grade 2 vomiting, no patient developed other adverse events in combination group. No significant differences in radiotherapy-related adverse events between the 2 groups were observed. CONCLUSIONS: h-R3 is a safe drug which may enhance the response of advanced NPC patients to radiotherapy. However, h-R3 seems not to significantly affect the long-term outcomes.

[Multi-center phase II clinical trial of humanized anti-epidermal factor receptor monoclonal antibody h-R3 combined with radiotherapy for locoregionally advanced nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the efficacy and safty of the humanized anti-epidermal factor receptor monoclonal antibody h-R3 in combination with radiotherapy for locoregionally advanced nasopharyngeal carcinoma. METHODS: Totally, 137 patients from 7 medical center around China were randomly divided into combined therapy group or control group. There was no difference in Karnofsky performance score between two groups. All patients in both groups received radical conventionally fractionated radiotherapy to the total dose of D(T) 70-76 Gy. For the combined therapy group, h-R3 was added at a dose of 100 mg i.v. weekly for 8 weeks started at the beginning of radiotherapy. RESULTS: Of the 137 eligilbe patients, 70 were in the combined therapy group treated by h-R3 plus radiotherapy and 67 in the control group by radiotherapy alone. The intent-to-treat (ITT) population consisted of 130 patients, while the per-protocol (PP) population was composed of 126 patients. The efficacy was assessed respectively at three point of time: the end of treatment, the 5th- and 17th-week after treatment. The complete response (CR) of the combined therapy group was significantly higher than that of the control group in both ITT and PP (ITT: 65.63%, 87.50%, 90.63% versus 27.27%, 42.42%, 51.52%; PP: 67.21%, 90.16%, 93.44% versus 27.69%, 43.08%, 52.31%; P < 0.05, respectively). The most common h-R3-related adverse reactions were fever (4.3%), hypotension (2.9%), nausea (1.4%), dizziness (2.9%) and rash (1.4%), which could be reversible if treated properly. Radiotherapy combined with 100 mg h-R3 i. v. weekly was tolerable and did not aggravate the side effects of radiation. The quality of life in the combined therapy group was comparable to that in the control group. CONCLUSION: This phase 1 multicenter clinical trial shows that h-R3 in combination with radiotherapy is effective and well-tolerated for the treatment of locoregionally advanced nasopharyngeal carcinoma.