CCND1 G870A polymorphism and colorectal cancer risk: An updated meta-analysis

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.

Association between Cyclin D1 G870A (rs9344) polymorphism and cancer risk in Indian population: meta-analysis and trial sequential analysis

Introduction: Association between Cyclin D1 (CCND1) single nucleotide polymorphism (SNP) rs9344 and cancer risk is paradoxical. Thus, we performed a meta-analysis to explore the association between CCND1 variant and overall cancer risk in Indian population. Methods: Data from 12 published studies including 3739 subjects were collected using Pubmed and Embase. RevMan (Review Manager) 5.3 was used to perform the meta-analysis. OR with 95%CI were calculated to establish the association. Results: Overall, the cumulative findings demonstrated that CCND1 polymorphism (rs9344) was not significantly associated with cancer risk in all the genetic models studied (dominant model: GG vs GA+AA: OR (95%CI) = 0.81 (0.60-1.09), P=0.17; recessive model: GG+GA vs AA: OR (95%CI) = 1.23 (0.96-1.59), P=0.11; co-dominant model: GG vs AA: OR (95%CI) = 1.35 (0.93-1.97), P=0.12; co-dominant model: (GG vs GA: OR (95%CI) = 1.16 (0.85-1.59), P=0.34; allelic model: A vs G: OR (95%CI) = 1.20 (1.14-2.85), P=0.23; allelic model: G vs A: OR (95%CI) = 0.83 (0.62-1.12), P=0.23). Subgroup analysis according to cancer types presented significant association of CCND1 polymorphism and increased breast cancer risk in dominant model (GG vs GA+AA: OR = 2.75, 95%CI = 1.54-4.90, P=0.0006) and allelic model (G vs A: OR = 1.63, 95%CI = 1.22-2.19, P=0.001). An increased esophageal cancer risk in recessive model (GG+GA vs AA: OR = 1.51, 95%CI = 1.05-2.16, P=0.03) and co-dominant model (GG vs AA: OR = 2.51, 95%CI = 1.10-5.71, P=0.03) was detected. A higher risk for colorectal cancer was detected under both the co-dominant models (GG vs AA: OR = 2.46, 95%CI = 1.34-4.51, P=0.004 and GG vs GA: OR = 1.74, 95%CI = 1.14-2.67, P=0.01). However, in case of cervical cancer risk a non-significant association was reported under the recessive model (GG+GA vs AA: OR = 1.52, 95%CI = 0.60-3.90, P=0.38) with reference to CCND1 polymorphism (rs9344). The trial sequential analysis (TSA) showed that the cumulative Z-curve neither crossed the trial sequential monitoring boundary nor reached the required information size (RIS). Thus, present meta-analysis remained inconclusive due to insufficient evidence. Conclusion:CCND1 polymorphism rs9344 may not have a role in overall cancer susceptibility in Indian population. However, this polymorphism acts as a crucial risk factor for breast, esophageal, and colorectal cancer but not for cervical cancer. Future studies with larger sample size are required to draw a reliable conclusion.

Relationship between polymorphisms of the lipid metabolism-related gene PLA2G16 and risk of colorectal cancer in the Chinese population

This study aimed to investigate the relationship between polymorphisms in the lipid metabolism-related gene PLA2G16 encoding Group XVI phospholipase A2 and the risk of colorectal cancer (CRC) in the Chinese population. A total of 185 patients with CRC and 313 healthy controls were enrolled. Thirteen single nucleotide polymorphisms (SNPs) of PLA2G16 were genotyped with SNPscan™. Linkage disequilibrium and haplotypes were analysed using Haploview software. Multivariate logistic regression was used to determine the association between the various genotypes and CRC risk. We identified five PLA2G16 SNPs (rs11600655, rs3809072, rs3809073, rs640908 and rs66475048) that were associated with CRC risk after adjusting for age, sex and body mass index. Two haplotypes (CTC and GGA) of rs11600655, rs3809073 and rs3809072, were relevant to CRC risk. The rs11600655 polymorphism was also associated with lymph node metastasis and CRC staging, while rs3809073 and rs3809072 may affect transcriptional regulation of PLA2G16 by altering transcription factor binding. These findings suggest that PLA2G16 polymorphisms-especially CTC and GGA haplotypes-increase CRC susceptibility. Importantly, we showed that the rs11600655 CC, rs640908 CT and rs66475048 GA genotypes are independent risk factors for CRC in the Chinese population.

CDCA3 promotes cell proliferation by activating the NF-κB/cyclin D1 signaling pathway in colorectal cancer

Cell division cycle associated 3 (CDCA3) is required for mitotic entry, and mediates the degradation of the inhibitory kinase Wee1. New evidence suggests CDCA3 plays a role in tumor promotion. However, little is known about the relevance of CDCA3 in colorectal cancer(CRC), especially in the regulation of NF-κB activity. In this study, we found that colorectal tumors significantly expressed more CDCA3 than non-cancer tissues. In addition, CDCA3 promoted CRC cell proliferation in vitro. Furthermore, downregulation of CDCA3 not only induced cell cycle arrest but also facilitated apoptosis. Mechanistically, CDCA3 activates the NF-κB signaling pathway by interacting with TRAF2 in CRC. Together, these results define a tumor-supportive role for CDCA3, which may also provide a new promising strategy for treating CRC.

Low penetrance genetic polymorphisms as potential biomarkers for colorectal cancer predisposition

Colorectal cancer is a leading form of cancer in both males and females. Early detection of individuals at risk of colorectal cancer allows proper treatment and management of the disease to be implemented, which can potentially reduce the burden of colorectal cancer incidence, morbidity and mortality. In recent years, the role of genetic susceptibility factors in mediating predisposition to colorectal cancer has become more and more apparent. Identification of high-frequency, low-penetrance genetic polymorphisms associated with the cancer has therefore emerged as an important approach which can potentially aid prediction of colorectal cancer risk. However, the overwhelming amount of genetic epidemiology data generated over the past decades has made it difficult for one to assimilate the information and determine the exact genetic polymorphisms that can potentially be used as biomarkers for colorectal cancer. This review comprehensively consolidates, based primarily on results from meta-analyses, the recent progresses in the search of colorectal cancer-associated genetic polymorphisms, and discusses the possible mechanisms involved.

State of Art of Cancer Pharmacogenomics in Latin American Populations

Over the past decades, several studies have shown that tumor-related somatic and germline alterations predicts tumor prognosis, drug response and toxicity. Latin American populations present a vast geno-phenotypic diversity due to the great interethnic and interracial mixing. This genetic flow leads to the appearance of complex characteristics that allow individuals to adapt to endemic environments, such as high altitude or extreme tropical weather. These genetic changes, most of them subtle and unexplored, could establish a mutational profile to develop new pharmacogenomic therapies specific for Latin American populations. In this review, we present the current status of research on somatic and germline alterations in Latin America compared to those found in Caucasian and Asian populations.

Single Nucleotide Polymorphism (A870G) of the CCND1 gene: association with colorectal cancer susceptibility

AIM

The aim of this study is to demonstrate the role of CCND1 gene polymorphism, A870G, in susceptibility to sporadic colorectal cancer in Iranian population.

BACKGROUND

It has been distinguished that CCND1 gene is one of the main genes in Wnt signaling pathway which involves in generating colorectal cancer. Nonetheless, there is no consistent result in terms of association between the genetic variations of this gene and colorectal cancer risk.

METHODS

We designed a case-control study consisting of 100 subjects with colorectal cancer (CRC) and 100 healthy controls to investigate the effect of A870G polymorphism on CRC susceptibility in an Iranian population. Genotype determination was performed by PCR-RFLP method.

RESULTS

The frequency of GG, AG and AA genotypes for cases were 24%, 51% and 25% respectively, while the genotype frequency for controls were 21%, 50% and 29% respectively. It was identified that there is no significant association between A870G polymorphism and risk of CRC, even after adjusting sex, age and smoking status variables (P = 0.777; OR=1.32 95% CI: 0.6-2.93)..

CONCLUSION

Despite the well-known role of CCND1 gene in cell cycle regulation, our results revealed that A870G polymorphism could not be a potential predisposing risk factor in genetic susceptibility to CRC, at least in the studied population.