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

Aberrant Cyclin D1 splicing in cancer: from molecular mechanism to therapeutic modulation

Cyclin D1 (CCND1), a crucial mediator of cell cycle progression, possesses many mutation types with different mutation frequencies in human cancers. The G870A mutation is the most common mutation in CCND1, which produces two isoforms: full-length CCND1a and divergent C-terminal CCND1b. The dysregulation of the CCND1 isoforms is associated with multiple human cancers. Exploring the molecular mechanism of CCND1 isoforms has offer new insight for cancer treatment. On this basis, the alterations of CCND1 gene are described, including amplification, overexpression, and mutation, especially the G870A mutation. Subsequently, we review the characteristics of CCND1 isoforms caused by G870A mutation. Additionally, we summarize cis-regulatory elements, trans-acting factors, and the splice mutation involved in splicing regulation of CCND1. Furthermore, we highlight the function of CCND1 isoforms in cell cycle, invasion, and metastasis in cancers. Importantly, the clinical role of CCND1 isoforms is also discussed, particularly concerning prognosis, chemotherapy, and radiotherapy. Last, emphasis is given to the corrective strategies that modulate the cancerous CCND1 isoforms. Thus, it is highlighting significance of aberrant isoforms of CCND1 as targets for cancer therapy.

Genetic and expression variations of cell cycle pathway genes in brain tumor patients

The present study was designed to determine the association between the genetic polymorphisms/expression variations of RB1 and CCND1 genes and brain tumor risk. For this purpose, 250 blood samples of brain tumor patients along with 250 controls (cohort I) and 96 brain tumor tissues (cohort II) with adjacent control section were collected. Mutation analysis of RB1 (rs137853294, rs121913300) and CCND1 (rs614367, rs498136) genes was performed using ARMS-PCR followed by sequencing, and expression analysis was performed using real-time PCR and immunohistochemistry. The results showed homozygous mutant genotype of RB1 gene polymorphism, rs121913300 (P=0.003) and CCND1 gene polymorphism rs614367 (P=0.01) were associated significantly with brain tumor risk. Moreover, significant down-regulation of RB1 (P=0.005) and up-regulation of CCND1 (P=0.0001) gene was observed in brain tumor sections vs controls. Spearman correlation showed significant negative correlation between RB1 vs proliferation marker, Ki-67 (r = -0.291*, P<0.05) in brain tumors. Expression levels of selected genes were also assessed at protein level using immunohistochemical analysis (IHC) and signification down-regulation of RB1 (P=0.0001) and up-regulation of CCND1 (P=0.0001) was observed in brain tumor compared with control sections. In conclusion, it is suggested that polymorphisms/expression variations of RB1 and CCND1 genes may be associated with increased risk of brain tumor.

Cyclin D1 G870A Polymorphism: Relation to the Risk of ALL Development, Prognosis Impact, and Methotrexate Cytotoxicity

Background:

Cyclin D1 (CCND1) regulates cell cycle progression during the late G1 and S phase and takes part in methotrexate metabolism. It was hypothesized that CCND1 gene polymorphism affects acute lymphoblastic leukemia (ALL) development, prognosis and may relate to methotrexate cytotoxicity.

Subjects and methods:

This study included 50 ALL patients and 50 healthy controls, CCND1 G870A polymorphism was studied in all items using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and evaluated methotrexate cytotoxicity for ALL patients using liver function tests before and after methotrexate treatment. We followed up patients for one year to determine disease-free survival (DFS) and overall survival (OS) and its relation to the CCND1 genotype.

Results:

We found that AA genotype and A allele have a higher risk of developing ALL compared to the control group. Additionally, we found no notable association between CCND1 variant and methotrexate cytotoxicity and no role of CCND1 polymorphism in ALL prognosis.

Conclusion:

Our results suggested that CCND1 G870A polymorphism is associated with a high risk of ALL development. However, it has no role in ALL prognosis or methotrexate cytotoxicity.

Upregulation of cyclin D1 can act as an independent prognostic marker for longer survival time in human nasopharyngeal carcinoma

Background

Cyclin D1 is an essential part of oncogenic transformation. We previously proved that cyclin D1 was upregulated in nasopharyngeal carcinoma (NPC) and promoted the NPC cell proliferation. But the association between cyclin D1 and the clinical outcome of NPC has not yet been determined. The study explores the possible relevance between the cyclin D1 expression and clinical parameters and its predictive value of prognosis in NPC patients.

Methods

We analyzed the clinical data from 379 NPC patients and 112 non‐NPC patients in our previous study, which made further statistics. Receiver operating curve (ROC) was applied to select the optimal cutoff points. By analyzing the clinical data from 101 NPC patients using Chi‐squared test, we estimated the relationship between the cyclin D1 expression level and clinicopathological parameters. We also used Kaplan‐Meier method and log‐rank test assess and compared the disease‐free survival (DFS) rate and overall survival (OS) rate. The Cox proportional hazards model was adopted to perform the univariate and multivariate analyses.

Result

Receiver operating curve analysis reported that cyclin D1 was used to differentiate between NPC patients and non‐NPC patients (P < .001, sensitivity: 53.6%, specificity: 85.7%, AUC = 0.752). Cyclin D1 was positively correlated with lymph node metastasis (P = .015). A survival analysis of the 101 NPC patients indicated that the positive expression of cyclin D1 was predictive of a good prognosis (DFS: P = .010, OS: P = .019). Multivariate analysis showed that cyclin D1 could be used independently to predict NPC patients' prognosis (DFS: P = .038).

Conclusion

The overexpression of cyclin D1 is a good prognostic marker for NPC.

Oxymatrine induces nasopharyngeal cancer cell death through inhibition of PI3K/AKT and NF‑κB pathways

Oxymatrine may inhibit tumor cell proliferation, induce cell cycle arrest, promote apoptosis, induce tumor cell differentiation and fight against tumor angiogenesis, as well as inhibit tumor invasion and metastasis. The present study aimed to investigate the anticancer effects of oxymatrine on nasopharyngeal cancer (NPC) cell death, and the underlying molecular mechanisms of these effects. NPC HK‑1 cells were incubated overnight and treated with oxymatrine (0, 2, 4, 6 and 8 mg/ml) for 1, 2 or 3 days. The results demonstrated that oxymatrine significantly inhibited NPC cell proliferation in a time‑ and dose‑dependent manner. Oxymatrine treatment also induced apoptosis, induced the activities of caspase‑3 and caspase‑9, promoted p53 and Bax protein expression, and suppressed cyclin D protein expression in these cells. The protein expression levels of phosphoinositide 3 kinase (PI3K), phosphorylated (p)‑AKT, p‑mammalian target of rapamycin, p‑p70 ribosomal protein S6 kinase and nuclear factor (NF)‑κB were significantly downregulated by oxymatrine treatment. In conclusion, results from the present study suggested that oxymatrine may induce NPC cell death through the inhibition of PI3K/AKT and NF‑κB signaling pathways.

Clinical significance and prospective molecular mechanism of MALAT1 in pancreatic cancer exploration: a comprehensive study based on the GeneChip, GEO, Oncomine, and TCGA databases

Purpose

Long noncoding RNAs (lncRNAs) are known to function as regulators in the development and occurrence of various tumors. MALAT1 is a highly conserved lncRNA and has vital functions in diverse tumors, including pancreatic cancer (PC). However, the underlying molecular regulatory mechanism involved in the occurrence and development of PC remains largely unknown. Thus, it is important to explore MALAT1 in PC and elucidate its function, which might offer a new perspective for clinical diagnosis and therapy.

Methods

First, we used the Gene Expression Omnibus, Oncomine, and The Cancer Genome Atlas databases to determine the clinical diagnostic and prognostic values of MALAT1. We next used our own GeneChip and The Cancer Genome Atlas database to collect the possible target genes of MALAT1 and further utilized a bioinformatics analysis to explore the underlying significant pathways that might be crucial in PC. Finally, we identified several key target genes of MALAT1 and hope to offer references for future research.

Results

We found that the expression of MALAT1 was significantly elevated in patients with PC. A receiver operating characteristics curve analysis showed a moderate diagnostic value (area under the curve =0.75, sensitivity =0.66, specificity =0.72). A total of 224 important overlapping genes were collected, and six hub genes (CCND1, MAPK8, VEGFA, FOS, CDH1, and HSP90AA1) were identified, of which CCND1, MAPK8, and VEGFA, are important genes in PC. Several pathways, including the mTOR signaling pathway, pathways in cancer, and the MAPK signaling pathway, were suggested to be the vital MALAT1 pathways in PC.

Conclusion

MALAT1 is suggested to be a promising diagnostic biomarker in PC. Six hub genes (CCND1, MAPK8, VEGFA, FOS, CDH1, and HSP90AA1), and specifically CCND1, MAPK8, and VEGFA, might be key MALAT1 target genes in PC. Due to their possible clinical significance in PC, several pathways, such as the mTOR signaling pathway, pathways in cancer, and the MAPK signaling pathway, are worthy of further study.

Relationships between cell cycle pathway gene polymorphisms and risk of hepatocellular carcinoma

AIM: To investigate the associiations between the polymorphisms of cell cycle pathway genes and the risk of hepatocellular carcinoma (HCC).

METHODS: We enrolled 1127 cases newly diagnosed with HCC from the Tumor Hospital of Guangxi Medical University and 1200 non-tumor patients from the First Affiliated Hospital of Guangxi Medical University. General demographic characteristics, behavioral information, and hematological indices were collected by unified questionnaires. Genomic DNA was isolated from peripheral venous blood using Phenol-Chloroform. The genotyping was performed using the Sequenom MassARRAY iPLEX genotyping method. The association between genetic polymorphisms and risk of HCC was shown by P-value and the odd ratio (OR) with 95% confidence interval (CI) using the unconditional logistic regression after adjusting for age, sex, nationality, smoking, drinking, family history of HCC, and hepatitis B virus (HBV) infection. Moreover, stratified analysis was conducted on the basis of the status of HBV infection, smoking, and alcohol drinking.

RESULTS: The HCC risk was lower in patients with the MCM4 rs2305952 CC (OR = 0.22, 95%CI: 0.08-0.63, P = 0.01) and with the CHEK1 rs515255 TC, TT, TC/TT (OR = 0.73, 95%CI: 0.56-0.96, P = 0.02; OR = 0.67, 95%CI: 0.46-0.97, P = 0.04; OR = 0.72, 95%CI: 0.56-0.92, P = 0.01, respectively). Conversely, the HCC risk was higher in patients with the KAT2B rs17006625 GG (OR = 1.64, 95%CI: 1.01-2.64, P = 0.04). In addition, the risk was markedly lower for those who were carriers of MCM4 rs2305952 CC and were also HBsAg-positive and non-drinking and non-smoking (P < 0.05, respectively) and for those who were carriers of CHEK1 rs515255 TC, TT, TC/TT and were also HBsAg-negative and non-drinking (P < 0.05, respectively). Moreover, the risk was higher for those who were carriers of KAT2B rs17006625 GG and were also HBsAg-negative (P < 0.05).

CONCLUSION: Of 12 cell cycle pathway genes, MCM4, CHEK1 and KAT2B polymorphisms may be associated with the risk of HCC.