Genetic variations in death receptor domain 4 gene and the susceptibility to hepatitis C related hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide, particularly in Egypt. The role of apoptosis in tumorigenesis has been well-documented and resistance to apoptosis is a hallmark of cancer. Several studies discussed the association between death receptor 4 (DR4) genetic variants and HCC risk.

AIM

To study the possible link between DR4 gene polymorphisms and the susceptibility to HCC.

METHODS

Genotyping of DR4-C626G, -A683C, and DR4-A1322G single nucleotide polymorphisms (SNP) was determined by polymerase chain reaction assay for 100 de novo HCV-related HCC patients, 100 chronic hepatitis C-related liver cirrhosis patients, and 150 healthy controls.

RESULTS

DR4-A1322G polymorphic genotypes (AG and GG) were significantly higher in HCC and cirrhotic patients than controls. The AG genotype conferred two-fold increased risk of HCC (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.56-3.51) and the risk increased to three-fold for the GG genotype (OR, 3.51; 95%CI, 2.33-5.28). The frequency of DR4-C626G and -A683C SNPs in HCC and cirrhotic patients were not significantly different from the controls. Combined genotype analysis showed that coinheritance of the polymorphic genotypes of DR4-C626G and -A1322G conferred nine-fold increased risk of HCC (OR, 9.34; 95%CI, 3.76-23.12). The risk increased to be 12-fold when DR4-A683C and -A1322G variants were coinherited (OR, 11.9; 95%CI, 4.82-29.39). Coexistence of the variant genotypes of the three SNPs conferred almost 10-fold increased risk of HCC (OR, 9.75; 95%CI, 1.86-51.19).

CONCLUSIONS

The G allele of DR4 -A1322G could be considered as a novel independent molecular predictor for HCV-related HCC in the Egyptian population.

Evaluation of trail receptor 1 (DR4) polymorphisms C626G and A683C as risk factors of hepatocellular carcinoma

Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) plays an important role in many cancers including hepatocellular carcinoma (HCC). The aim of this study is to investigate the association of the DR4 polymorphisms C626G (Thr209Arg, rs20575) and A683C (Glu228Ala, rs20576) with the occurrence of HCC in Egyptian patients chronically infected with HCV. The study included 80 patients with HCV-related HCC (group 1) and 80 patients with HCV-related liver cirrhosis (group 2) who are naïve to treatment. Clinical and laboratory data were recorded. Genotyping of TRAIL receptor DR4 polymorphism C626G rs20575 and A683C rs20576 SNP was done by Real-Time PCR using taqman probes technology. The mean age of HCC patients was 57.6 ± 8.4 years with 62 patients (77.5%) were males. While group 2 mean age was 49.5 ± 10.29 years with 50% were males. The frequency distribution of rs20575 genotypes showed a statistically significant difference between the two studied groups (P = 0.02), the carriers of the C allele were 2.01 times more likely to develop HCC than the carriers of the G allele (P = 0.003), while no significant difference in rs20576 genotypes distribution was found between the studied groups (P = 0.680). On combining the carriers of C allele of rs20575 and the carriers of A allele of rs20576, a significant difference was detected (P > 0.001) with 2.85 higher risk of HCC development in patients who carried both genetic risk alleles simultaneously. The significant difference in DR4 polymorphisms among HCC and cirrhotic patients suggests their role as potential risk factors of HCC development.

Inflammatory pathway genes associated with inter-individual variability in the trajectories of morning and evening fatigue in patients receiving chemotherapy

Fatigue, a highly prevalent and distressing symptom during chemotherapy (CTX), demonstrates diurnal and interindividual variability in severity. Little is known about the associations between variations in genes involved in inflammatory processes and morning and evening fatigue severity during CTX. The purposes of this study, in a sample of oncology patients (N=543) with breast, gastrointestinal (GI), gynecological (GYN), or lung cancer who received two cycles of CTX, were to determine whether variations in genes involved in inflammatory processes were associated with inter-individual variability in initial levels as well as in the trajectories of morning and evening fatigue. Patients completed the Lee Fatigue Scale to determine morning and evening fatigue severity a total of six times over two cycles of CTX. Using a whole exome array, 309 single nucleotide polymorphisms SNPs among the 64 candidate genes that passed all quality control filters were evaluated using hierarchical linear modeling (HLM). Based on the results of the HLM analyses, the final SNPs were evaluated for their potential impact on protein function using two bioinformational tools. The following inflammatory pathways were represented: chemokines (3 genes); cytokines (12 genes); inflammasome (11 genes); Janus kinase/signal transducers and activators of transcription (JAK/STAT, 10 genes); mitogen-activated protein kinase/jun amino-terminal kinases (MAPK/JNK, 3 genes); nuclear factor-kappa beta (NFkB, 18 genes); and NFkB and MAP/JNK (7 genes). After controlling for self-reported and genomic estimates of race and ethnicity, polymorphisms in six genes from the cytokine (2 genes); inflammasome (2 genes); and NFkB (2 genes) pathways were associated with both morning and evening fatigue. Polymorphisms in six genes from the inflammasome (1 gene); JAK/STAT (1 gene); and NFkB (4 genes) pathways were associated with only morning fatigue. Polymorphisms in three genes from the inflammasome (2 genes) and the NFkB (1 gene) pathways were associated with only evening fatigue. Taken together, these findings add to the growing body of evidence that suggests that morning and evening fatigue are distinct symptoms.