Cyclin D1 G870A polymorphism and risk of nasopharyngeal carcinoma: a meta-analysis

The Relationship Between the hOGG1 rs1052133 Polymorphism and the Occurrence of Nasopharyngeal Carcinoma: A Systematic Review and Meta-Analysis

Objectives: Exploring the relationship between the hOGG1 rs1052133 polymorphism and the occurrence of nasopharyngeal carcinoma (NPC). Methods: PubMed, Web of Science, Scopus, CNKI, Wanfangdata, and VIP were used to search for studies and the NOS evaluation scale was used to evaluate the quality. All studies were grouped according to different genotypes. The Cochrane's Q test and I2 test were used for heterogeneity evaluations. If heterogeneity was small, the fixed effects model was used, and conversely, the random effects model was used. Publication bias was also detected. P < .05 in all results indicated statistically significant. Results: We ultimately included 6 studies with 2021 NPC patients in the study group and 2375 healthy populations in the control group. After meta-analysis, it was found that the total OR value of the "Ser/Cys (CG) vs Ser/Ser (CC)" group was 1.00 (95% CI: 0.85-1.18) and the "Cys/Cys (GG) vs Ser/Ser (CC)" group was 1.06 (95% CI: 0.87-1.28). These results were not statistically significant (P > .05). Furthermore, the integrated total OR values of each group were not statistically significant with or without the smoking history, even in other genotype models (Allele, Dominant, Recessive, and Additive) (P > .05). Conclusion: There is no clear correlation between the hOGG1 rs1052133 polymorphism and the occurrence of NPC, even with or without the smoking history.

Radiotherapy induces cell cycle arrest and cell apoptosis in nasopharyngeal carcinoma via the ATM and Smad pathways

Nasopharyngeal carcinoma (NPC) is a common malignant neoplasm of the head and neck which is harmful to human's health. Radiotherapy is commonly used in the treatment of NPC and it induces immediate cell cycle arrest and cell apoptosis. However, the mechanism remains unknown. Evidences suggested the activation of Ataxia telangiectasia mutated (ATM) pathway and Smad pathway are 2 of the important crucial mediators in the function of radiotherapy. In this study, we performed in vitro assays with human nasopharyngeal carcinoma CNE-2 cells and in vivo assays with nude mice to investigate the role of the ATM and Smad pathways in the treatment of nasopharyngeal carcinoma with radiotherapy. The results suggested that radiation induced activation of ATM pathway by inducing expression of p-ATM, p-CHK1, p-CHK2, p15 and inhibiting expression of p-Smad3. In addition, Caspase3 expression was increased while CDC25A was decreased, leading to cell cycle arrest and cell apoptosis. On the other hand, activation of Smad3 can inhibited the ATM pathway and attenuated the efficacy of radiation. In summary, we suggest that both ATM and Smad pathways contribute to the cell cycle arrest and cell apoptosis during nasopharyngeal carcinoma cells treated with radiation.

MicroRNA-124-3p inhibits the growth and metastasis of nasopharyngeal carcinoma cells by targeting STAT3

The present study investigated the effects of microRNA-124-3p (miR-124-3p) expression on nasopharyngeal carcinoma (NPC) cells and its relevant mechanism. A total of 90 NPC tissues and 85 postnasal catarrh tissues were collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect tissue samples and expression of miR-124-3p in CNE1, CNE2, SUNE1, H0NE1, 5-8F, 6-10B and C666-1 NPC cell line and immortalized nasopharyngeal epithelial cells line (NP69). Overexpressed miRNA-124-3p in CNE-2 was downregulated, and low-expressed miRNA‑124-3p in C666-1 was upregulated by liposome-mediated transfection. Cell Counting Kit-8 (CCK-8), flow cytometry, the scratch test, Transwell migration assay and Boyden chamber assays were used to detect cell proliferation, apoptosis, migration and invasion. The target gene of miRNA-124-3 calculated by bioinformatics was further determined using dual-luciferase system. Protein levels of the signal transducers and activators of transcription 3 (STAT3), phospho-STAT3 (p-STAT3), mouse anti-human cyclin D2 (CCND2) and matrix metalloproteinase-2 (MMP-2) were tested by western blotting. miRNA-124-3p expression in NPC was markedly downregulated compared to postnasal catarrh tissues (P<0.001); miRNA-124-3p expression showed close linkage with clinical stages, regional lymph node involvement and T stages (all P<0.001). miRNA-124-3p expression was lower in the 7 NPC cell lines than NP69 cells (all P<0.05). After upregulation of miR-124-3p, proliferation, apoptosis, migration and invasion of C666-1 cells were suppressed; while after downregulation of miR-124-3p, CNE2 cells were increased (all P<0.05). Expression of STAT3, p-STAT3, CCND2 and MMP-2 in C666-1 cells was decreased after transfection with miRNA-124-3p, and the above protein expression in CNE-2 cells was increased after inhibition of miRNA-124-3p (all P<0.05). To sum up, this study shows that miR-124-3p may negatively regulate the transcription of the STAT3 by interfering with its 3'UTR, and the degradation of STAT3 affects its downstream expression of such as p-STAT3, CCND2 and MMP-2, thereby promoting NPC cells apoptosis and inhibiting proliferation, migration and invasion of NPC cells.

Limb-bud and Heart (LBH) functions as a tumor suppressor of nasopharyngeal carcinoma by inducing G1/S cell cycle arrest

Epstein–Barr virus-encoded latent membrane protein-1 (LMP1) plays a fundamental role in the malignant transformation of nasopharyngeal carcinoma (NPC), although the mechanism is not well understood. Here, we showed that Limb-bud and Heart (LBH) is considerably downregulated in patient NPC tissues. The expression of LBH in biopsies of 40 consecutive NPC patients devoid of initial distant metastasis and treated according to consistent guidelines was also analyzed, and we found the LBH expression level was correlated with some of clinicopathological features, disease-specific survival (DSS), distant metastasis-free survival (DMFS). We further determined that LBH normally induces NPC cell cycle arrest at the G1/S transition, and LBH can suppress the growth of transplanted NPC tumors in vivo by downregulating LMP1-mediated NF-κB transcriptional activity. Transforming growth factor-beta 1 (TGF-β1) normally protects against tumor development by suppressing cell proliferation, but NPC cells acquire resistance to TGF-β1–mediated inhibition. We found that TGF-β1 inhibits NF-κB transcriptional activity and nasopharyngeal epithelial cell proliferation through upregulating LBH expression. These data reveal a previously unknown NPC transformation mechanism and provide a new concept and treatment strategy for LMP1-driven oncogenesis in NPC.

Cyclin D1 G870A polymorphism and risk of nasopharyngeal carcinoma: a case-control study and meta-analysis

Background

Cyclin D1 (CCND1) plays a key role in cell cycle regulation. It is a well-established human oncogene which is frequently amplified or overexpressed in cancers. The association between CCND1 G870A polymorphism and cancer risk has been widely assessed. However, a definitive conclusion between CCND1 G870A polymorphism and risk of nasopharyngeal carcinoma (NPC) remains elusive.

Methods

We firstly performed a hospital-based case-control study involving 165 NPC cases and 191 cancer-free controls in central-south China, and then conducted a meta-analysis with six case-control studies to evaluate the association between NPC risk and CCND1 G870A polymorphism.

Results

The case-control study found a significant association between CCND1 G870A polymorphism and NPC risk in various comparison models (AA vs. GG: OR = 2.300, 95% CI 1.089–4.857, p = 0.029; AG vs. GG: OR = 2.832, 95% CI 1.367–5.867, p = 0.005; AA/AG vs. GG: OR = 2.597, 95% CI 1.288–5.237, p = 0.008; AA vs. AG/GG: OR = 0.984, 95% CI 0.638–1.518, p = 0.944). Further meta-analysis showed that there was no significant association between CCND1 G870A polymorphism and NPC risk in overall analysis. In the stratified analysis by race, however, significant associations were only found in Caucasians (for the allele model A vs. G: OR = 0.75, 95% CI 0.59–0.97, p = 0.03; for the co-dominant model AA vs. GG: OR = 0.52, 95% CI 0.32–0.86, p = 0.01; for the dominant model AA/AG vs. GG: OR = 0.49, 95% CI 0.32–0.74, p<0.01; for the recessive model AA vs. AG/GG: OR = 0.90, 95% CI 0.61–1.34, p = 0.60).

Conclusions

A significant association between CCND1 G870A polymorphism and NPC risk was found in the central-southern Chinese population. The meta-analysis indicated that CCND1 G870A polymorphism may contribute to the development of NPC in Caucasians.

Cyclin D1 (CCND1) G870A polymorphisms and cervical cancer susceptibility: a meta-analysis based on ten case-control studies

Many studies have evaluated the association between cyclin D1 (CCND1) G870A polymorphism and cervical cancer susceptibility. However, these studies showed inconsistent results. The aim of this study was to derive a more precise estimation of this association. We searched PubMed and Embase for related studies that had been published in English, and ten case-control studies with a total of 2,864 cases and 3,898 controls were finally identified to be eligible studies in the meta-analysis. The association was assessed by summarizing the odds ratios (ORs) with the corresponding 95 % confidence intervals (CIs). Overall, there was no significant association between cyclin D1 (CCND1) G870A polymorphism and cervical cancer risk (for the allele model A vs. G: OR = 1.02, 95 % CI 0.88-1.19, p = 0.76; for the co-dominant model AA vs. GG: OR = 1.03, 95 % CI 0.75-1.41, p = 0.85; for the dominant model AA + GA vs. GG: OR = 1.00, 95 % CI 0.78-1.28, p = 0.99; for the recessive comparison AA vs. GA + GG: OR = 1.06, 95 % CI 0.85-1.32, p = 0.62). In subgroup analysis by ethnicity, no significant difference was found in both Asians and Caucasians. In summary, the present meta-analysis provides evidence that genotypes for the cyclin D1 (CCND1) G870A polymorphism may be not associated with genetic susceptibility of cervical cancer.