Association between CDKN1A gene rs1801270 polymorphisms and susceptibility to colorectal cancser in an Iranian population.

CDKN1A gene is implicated in cell differentiation, development process, repair, apoptosis, senescence, migration, and tumorigenesis. Somatic alterations and polymorphisms may interfere in the function of CDKN1A, and this could affect the individual susceptibility to colorectal cancer (CRC). Here in, we evaluated the importance of single nucleotide polymorphic variants in codon 31 of CDKN1A (rs1801270: C > A) for the development of colorectal cancer in an Iranian population. A total of 150 CRC patients and 150 healthy controls were enrolled in this study. Genomic DNA was extracted from peripheral blood specimens. Genotypes were determined using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) assay. In CRC patients, the genotype frequencies detected were 90%, 8.0% and 2.0%2 for CC, AC and AA genotypes while the genotype frequencies in control group were 78%, 20.7% and 1.35% 1.35% for CC, AC and AA genotype, respectively. There were statistically significant differences in the distribution of CDKN1A rs1801270 genotypes and allele frequencies between colorectal cancer patients and healthy controls (p value = 0.021). Also, results indicated a significant negative association between AC genotype and risk of colorectal cancer occurrence. (Odds ratio (OR)=0.357; 95% confidence interval (CI)=0.168-0.760, p = 0.007). Our data suggest that the AC genotype may have a protective role in the development of CRC in an Iranian population.

Novel long noncoding RNAs upregulation may have synergistic effects on the CYP24A1 and PFDN4 biomarker role in human colorectal cancer.

Long noncoding RNAs (lncRNAs) are emerging as the master regulators of tumor initiation, proliferation, and metastasis; however, their diagnostic value as potential biomarkers should be clarified. Vitamin D influences the expression of several genes in various pathways, including the CYP24A1 gene in the vitamin D metabolism pathway. In the present research, we surveyed the expression levels and clinical significance of novel lncRNAs related to CYP24A1 and PFDN4 genes in colorectal cancer (CRC) using real-time polymerase chain reaction. Furthermore, we assessed the expression of these genes after vitamin D treatment in HCT-116 and HT-29 colon cancer cell lines. Our results indicated that the transcription of CYP24A1, PFDN4, and nearby lncRNAs was affected by vitamin D treatment in HCT-116 and HT-29 cell lines. Moreover, CYP24A1, PFDN4, lnc-CYP24A1-3:1, and lnc-TSHZ2-19:1 were upregulated and had the potential to distinguish colorectal cancer tissues from the adjacent tissues by the large area under the receiver operating characteristic curve (0.94, 0.66, 0.70, and 0.60, respectively). lnc-TSHZ2-19:1 expression level significantly correlated with gender (p = .03). In conclusion, CYP24A1, PFDN4, lnc-CYP24A1-3:1, and lnc-TSHZ2-19:1 can be used as potential diagnostic biomarkers in the specific and sensitive assessment of CRC. Besides this, vitamin D treatment may modulate the expression of these genes in a cell-specific manner.

Lack of association between VEGF -2578C/A polymorphism and risk of colorectal cancer in an Iranian population.

AIM: Here, we evaluated the VEGF gene -2578C/A polymorphism as a potential susceptibility factor in colorectal cancer (CRC) occurrence amongst Iranian CRC patients. BACKGROUND: Vascular endothelial growth factor (VEGF) is a key regulatory factor in angiogenesis which plays essential roles in the development of malignancy in colorectal cancer (CRC), as the third most prevalent cancer worldwide. METHODS: VEGF -2578C/A polymorphism was evaluated in 200 CRC patients and 200 healthy control subjects via restriction fragment length polymorphism analysis. RESULTS: The frequencies of CC, AC and AA genotypes among CRC patients were 22.5%, 51% and 26.5%, respectively, with their respective genotype frequencies at 16%, 54% and 30% in control cohorts (P=0.247). The A allele frequency among the case group was 52% and for control group, it was 57%. C allele frequency in case and control groups was 48% and 43%, respectively (p=0.156). No significant association was observed (p=0.990) between this polymorphism and CRC stage. CONCLUSION: Our findings provide limited support for the hypothesis that the -2578C/A VEGF are associated with increased risk of colorectal cancer in Iranian colorectal cancer patients and suggest instead that meta data studies, which have previously relied upon populations definitions such as 'Asian', should more specifically take into account country of origin when associating prognostic value to a given genotype.

The Differential DNA Hypermethylation Patterns of microRNA-137 and microRNA-342 Locus in Early Colorectal Lesions and Tumours.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, representing 13% of all cancers. The role of epigenetics in cancer diagnosis and prognosis is well established. MicroRNAs in particular influence numerous cancer associated processes including apoptosis, proliferation, differentiation, cell-cycle controls, migration/invasion and metabolism. MiRNAs-137 and 342 are exon- and intron-embedded, respectively, acting as tumour-suppressive microRNA via hypermethylation events. Levels of miRNAs 137 and 342 have been investigated here as potential prognostic markers for colorectal cancer patients. The methylation status of miRNA-137 and miRNA-342 was evaluated using methylation-specific (MSP) polymerase chain reaction (PCR) on freshly frozen tissue derived from 51 polyps, 8 tumours and 14 normal colon mucosa specimens. Methylation status of miRNA-137 and miRNA-342 was significantly higher in tumour lesions compared to normal adjacent mucosa. Surprisingly, the methylation frequency of miR-342 (76.3%) among colorectal cancer patients was significantly higher compared to miR-137 (18.6%). Furthermore, normal tissues, adjacent to the lesions (N-Cs), displayed no observable methylation for miRNA-137, whereas 27.2% of these N-Cs showed miRNA-342 hypermethylation. MiRNA-137 hypermethylation was significantly higher in male patients and miR-342 hypermethylation correlated with patient age. Methylation status of miRNA-137 and miRNA-342 has both diagnostic and prognostic value in CRC prediction and prevention.

Evaluation of promoter methylation status of MLH1 gene in Iranian patients with colorectal tumors and adenoma polyps.

AIM: The aim of this study was to evaluate the methylation status of the promoter region of MLH1 gene in colorectal cancer (CRC) and its precursor lesions as well as elucidate its association with various clinicopathological characteristics among Iranian population. BACKGROUND: Epigenetic silencing of mismatch repair genes, such as MLH1, by methylation of CpG islands of their promoter region has been proved to be an important mechanism in colorectal carcinogenesis. METHODS: Fifty colorectal cancer and polyp tissue samples including 13 Primary colorectal tumor and 37 Adenoma polyp samples were enrolled in this study. Methylation-specific polymerase chain reaction (MSP) was performed to find the frequency of MLH1 Promoter Methylation. RESULTS: Promoter methylation of MLH1 gene was detected in 5 out of 13 tumor tissues and 4 out of 37 adenoma polyp. The frequency of MLH1 methylation in tumor samples was significantly higher compared to that in polyp tissues (P= 0.026). No significant association was observed between MLH1 promoter methylation and clinicopathological characteristics of the patients. CONCLUSION: The frequency of MLH1 promoter methylation in CRC and colon polyp was 18%. Our findings indicated that methylation of MLH1 promoter region alone cannot be considered as a biomarker for early detection of CRC.

Expression of liver alpha-amylase in obese mouse hepatocytes.

AIM: The aim of this study is to demonstrate the relation between the expression of liver alpha-amylase and obesity. BACKGROUND: Alpha-amylase catalyses the hydrolysis of 1, 4-alpha-glucosidic linkages in polysaccharides and has three main subtypes, including: salivary, pancreatic, and hepatic. Hepatic alpha-amylase is involved in glycogen metabolism, and has a role in obesity and its management. In this study, we aimed to analyze the expression of liver alpha-amylase in overweight and obese mouse. MATERIAL AND METHODS: In this study, NMRI male mice were randomly divided into two groups. The sample group (obese) took a high-fat and carbohydrate diet, while the control group (normal) took a laboratory pellet chow for eight weeks. During this period, their weight was measured. After eight weeks, liver hepatocytes were isolated using an enzymatic digestion method. Immunocytochemistry (ICC) and flow cytometry analysis were performed to measure alpha amylase protein expression in mouse liver hepatocyte cells. RESULTS: A significant difference in the body weight was observed between the two groups (p<0.05). The qualitative protein expression of liver alpha-amylase was found to be higher in the obese group in both tests (immunocytochemistry and flow cytometry). Animals from the test group presented higher alpha-amylase expression, which suggests that this hepatic protein may constitute a potential indicator of susceptibility for fat tissue accumulation and obesity. The present data demonstrates an increased expression of liver amylase in obese mice. CONCLUSION: These results suggest that liver amylase secretion might be useful for predicting susceptibility to obesity induced by consumption of a high-fat and carbohydrate diet.

Lack of Association between NOD2 rs3135500 and IL12B rs1368439 microRNA Binding Site SNPs and Colorectal Cancer Susceptibility in an Iranian Population.

OBJECTIVE: The purpose of this study was to evaluate the potential association between single nucleotide polymorphisms (SNPs) in microRNA (miRNA) binding sites in the NOD2 and IL12B gene 3.-untranslated regions and colorectal cancer (CRC) susceptibility in an Iranian population. METHODS: We genotyped NOD2 rs3135500 [3. untranslated region (UTR) A/G] and IL12B rs1368439 (3.UTR G /T) in a hospital-based study of 92 colorectal cancer cases and 105 healthy controls. All samples were genotyped by TaqMan assay via an ABI 7500 Real Time PCR System (Applied Biosystems) with DNA from FFPE tissue and peripheral blood. RESULTS: our results showed similar distribution of genotype and allelic frequencies of the NOD2 and IL12B polymorphisms between patients and controls. When the more common rs3135500 AA genotype was used as the reference, the rs3135500 AG and rs3135500 GG genotypes were not significantly associated with the risk of CRC (OR = 1.294, 95% CI: 0.524 -3.197; and OR = 2.230, 95% CI: 0.87 - 5.715, respectively), and The IL12B rs1368439 TG and IL12B rs1368439 GG genotypes were not significantly associated with the risk of CRC compared with the IL12B rs1368439 TT genotype (OR = 1.547 95% CI: 0.187- 12.771; and OR = 1.753, 95% CI: 0.217-14.157, respectively). CONCLUSION: NOD2 rs3135500 and IL12B rs1368439 SNPs were not genetic risk factors for colorectal cancer in the studied Iranian population.

Low Level of Microsatellite Instability Correlates with Poor Clinical Prognosis in Stage II Colorectal Cancer Patients.

The influence of microsatellite instability (MSI) on the prognosis of colorectal cancer (CRC) requires more investigation. We assessed the role of MSI status in survival of individuals diagnosed with primary colorectal cancer. In this retrospective cross-sectional study the MSI status was determined in 158 formalin-fixed paraffin-embedded tumors and their matched normal tissues from patients who underwent curative surgery. Cox proportional hazard modeling was performed to assess the clinical prognostic significance. In this study we found that MSI-H tumors were predominantly located in the colon versus rectum (p = 0.03), associated with poorer differentiation (p = 0.003) and TNM stage II/III of tumors (p = 0.02). In CRC patients with stage II, MSI-L cases showed significantly poorer survival compared with patients who had MSI-H or MSS tumors (p = 0.04). This study indicates that MSI-L tumors correlate with poorer clinical outcome in patients with stage II tumors (p = 0.04) or in tumors located in the colon (p = 0.02). MSI-L characterizes a distinct subgroup of CRC patients who have a poorer outcome. This study suggests that MSI status in CRC, as a clinical prognostic marker, is dependent on other factors, such as tumor stage and location.

Correlation between the EGF gene intronic polymorphism, rs2298979, and colorectal cancer.

Colorectal cancer (CRC) is an important disorder that results from genetic and epigenetic alterations in one colonic epithelial cell. Epidermal growth factor (EGF) is critical in the development of tumors in epithelial tissues. Variations in the DNA sequence of the EGF gene may be particularly significant with regard to susceptibility to CRC. The present study aimed to investigate the effect of the EGF gene single nucleotide polymorphism (SNP), rs2298979, on CRC. In this prospective study, 220 samples were collected from patients with CRC and compared with 220 matched healthy controls. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and the result was validated by direct sequencing. A significant correlation was observed between the rs2298979 variant in the EGF gene and CRC. The frequency of the A/G genotype in the control group was higher than in the patients with sporadic CRC [odds ratio (OR), 0.488; 95% confidence interval (CI), 0.307-0.774; P=0.002]. In this study there were no individuals with a G/G genotype. Although the frequency of the G and A alleles was similar in the healthy control and CRC patient groups, individuals with the A/G genotype were less susceptible to CRC compared with those with the A/A genotype.

Programmed death-1 gene polymorphism (PD-1.5 C/T) is associated with gastric cancer.

AIM: This study aimed to determine the association between PD-1.5C/T (rs2227981, +7785) and the risk of gastric cancer (GC) in an Iranian population. BACKGROUND: Gastric cancer is the fourth most common cancer in the world. The programmed death 1 (PD-1) is a member of the CD28 super family. PD-1 is a negative regulator of T-cell effector mechanisms which decrease immune responses against cancer. PATIENTS AND METHODS: we conducted case- control study to investigate the association of PD-1.5 C/T polymorphism in 122 GC patients and 166 control individuals. DNA was extracted from blood specimens. Genotypes were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. RESULTS: The frequency of CC, CT and TT genotypes was 53.6%, 42.2% and 4.2% in control group and 41%, 54.1% and 4.9% in gastric cancer patients respectively. CC genotype was more frequent in control individuals than in patients but we found no statically significant association. The frequencies of PD-1.5CT genotypes were significantly higher in GC patient compared with control individuals (OR= 1.77, 95% CI= 1.077-2.931; P=0.026). Allele distribution was similar in patients and healthy individuals (p = 0.061).Frequency of C and T alleles was 74.7%, 25.3% in control individuals and 68.03% and 31.97% in gastric cancer patients respectively. CONCLUSION: These results suggest that PD-1.5 C/T polymorphism may affect the GC risk and prognosis in an Iranian population.

Different frequency of epidermal growth factor rs76189946 polymorphism genotype in an Iranian colorectal cancer.

AIM: This study aimed to determinant association between rs76189946 polymorphism of EGF gene and risk of colorectal cancer in an Iranian population. BACKGROUND: Colorectal cancer (CRC) is the third most prevalent cancer in both genders worldwide. The determination of genetic variation becomes a new way to etiology of colorectal cancer. Epidermal growth factor (EGF) is a mitogen that plays an important role in cell growth and tumourigenesis, this protein acts by binding its receptor, EGFR. PATIENTS AND METHODS: DNA samples taken from totally 125 CRC patients and healthy controls were amplified by polymerase chain reaction (PCR) for the rs76189946 polymorphism. Genotypes were analyzed using restriction fragment length polymorphism (RFLP). Finally to confirm the RFLP procedure, 20 of the PCR products were sequenced using the ABI PRISM 3130xl Genetic Analyzer and chain termination method (Applied Biosystems, Carlsbad, CA). RESULTS: Genotype distribution and allele frequency was similar in CRC patients and controls individuals. We expect observe C and G allele in both groups but only was found C allele. CONCLUSION: In this study for first time we identified genetic distribution of exonic rs76189946 polymorphism in EGF gene both CRC patients and healthy controls. These results suggest there wasn't association between EGF polymorphism rs76189946 and risk of colorectal cancer in an Iranian population.