The ERBB2 gene polymorphisms rs2643194, rs2934971, and rs1058808 are associated with increased risk of gastric cancer.

Gastric cancer (GC) is the third most lethal type of cancer worldwide. Single nucleotide polymorphisms (SNPs) in regulatory sites or coding regions can modify the expression of genes involved in gastric carcinogenesis, as ERBB2, which encodes for the tyrosine-kinase receptor HER-2. The aim of this work was to analyze the association of the polymorphisms: rs2643194, rs2517951, rs2643195, rs2934971, and rs1058808 with GC, as they have not yet been analyzed in GC patients, as well as to report their frequency in the general Mexican population (GMP). We studied genomic DNA from subjects with GC (n=74), gastric inflammatory diseases (GID, n=76 control subjects), and GMP (n=102). Genotypes were obtained by means of real-time PCR and DNA-sequencing. The risks for GC were estimated through odds ratio (OR) using the Cochran-Armitage trend test and multinomial logistic regression. Increased risk for GC was observed under the dominant inheritance model for the rs2643194 TT or CT genotypes with an OR of 2.75 (95%CI 1.12-6.75, P=0.023); the rs2934971 TT or GT genotypes with an OR of 2.41 (95%CI 1.01-5.76, P=0.043), and the rs1058808 GG or CG genotypes with an OR of 2.21 (95%CI 1.00-4.87, P=0.046). The SNPs rs2643194, rs2934971, and rs1058808 of the ERBB2 gene were associated with increased risk for GC.

The ERBB2 gene polymorphisms rs2643194, rs2934971, and rs1058808 are associated with increased risk of gastric cancer

Gastric cancer (GC) is the third most lethal type of cancer worldwide. Single nucleotide polymorphisms (SNPs) in regulatory sites or coding regions can modify the expression of genes involved in gastric carcinogenesis, as ERBB2, which encodes for the tyrosine-kinase receptor HER-2. The aim of this work was to analyze the association of the polymorphisms: rs2643194, rs2517951, rs2643195, rs2934971, and rs1058808 with GC, as they have not yet been analyzed in GC patients, as well as to report their frequency in the general Mexican population (GMP). We studied genomic DNA from subjects with GC (n=74), gastric inflammatory diseases (GID, n=76 control subjects), and GMP (n=102). Genotypes were obtained by means of real-time PCR and DNA-sequencing. The risks for GC were estimated through odds ratio (OR) using the Cochran-Armitage trend test and multinomial logistic regression. Increased risk for GC was observed under the dominant inheritance model for the rs2643194 TT or CT genotypes with an OR of 2.75 (95%CI 1.12−6.75, P=0.023); the rs2934971 TT or GT genotypes with an OR of 2.41 (95%CI 1.01−5.76, P=0.043), and the rs1058808 GG or CG genotypes with an OR of 2.21 (95%CI 1.00−4.87, P=0.046). The SNPs rs2643194, rs2934971, and rs1058808 of the ERBB2 gene were associated with increased risk for GC.

Association between the CDH1-472delA and -160C>A polymorphisms and diffuse and intestinal gastric cancer in a Mexican population.

Gastric cancer (GC), the third leading cause of cancer-related deaths in Mexico and worldwide, can be classified into diffuse (DGC) or intestinal (IGC) types based on its histological characteristics. DGC is characterized by reduced expression of the cell adhesion protein E-cadherin, which is encoded by CDH1. The -472delA (rs5030625) and -160C>A (rs16260) polymorphisms in CDH1 induce a decrease in gene transcription; in fact, these mutated alleles have been associated with GC in some populations, with conflicting results. The aim of this study was to determine the association between the CDH1 -472delA and -160C>A polymorphisms and DGC and IGC in Mexican patients. The study was conducted in 24, 23, 48, and 93 individuals with DGC and IGC, without GC (control), and belonging to the general Mexican population (GMP), respectively. The genotypes were obtained by polymerase chain reaction - restriction fragment length polymorphism and the obtained data analyzed using Arlequin 3.1. The frequencies of the mutated allele (A) of -472delA were 0.326, 0.318, 0.284, and 0.296 in the DGC, IGC, control, and GMP groups, respectively, and those of the -160C>A polymorphism were 0.174, 0.318, 0.313, and 0.280, respectively. The genotype and allele frequencies of the two polymorphisms did not differ significantly (P > 0.05) among DGC, IGC, and control subjects. Therefore, we concluded that the CDH1 -472delA and -160C>A polymorphisms are not associated with DGC or IGC in patients from western Mexico.

Epidermal growth factor receptor expression in gastric tumors and its relationship with the germline polymorphisms - 216 G>T, -191 C>A, (CA) n IVS1, and R521K.

BACKGROUND: Gastric cancer (GC) is the third worldwide leading cause of cancer-related death affecting both sexes. The aberrant expression of epidermal growth factor receptor (EGFR) gene has been detected in many human epithelial malignancies and linked to advanced disease, more aggressive phenotype, and poor prognosis. AIMS: To analyze the relation that the expression of EGFR in gastric tumors holds with pathological characteristics and with the germline polymorphisms -216 G>T, -191 C>A, (CA) n IVS1, and R521K. MATERIALS AND METHODS: We studied 22 biopsies from gastric tumors obtained by endoscopy. EGFR expression was determined by relative quantification real-time polymerase chain reaction with the glyceraldehyde-3-phosphate dehydrogenase reference gene (as for messenger RNA [mRNA]) and by immunohistochemistry (IHC) (as for protein). EGFR germline polymorphisms were analyzed by sequencing, GeneScan, and restriction fragment length polymorphisms. RESULTS: EGFR mRNA expression was increased (>2-fold) in 13.6% of GC cases, decreased (<0.5-fold) in 68.2%, and normal in 18.2%; overexpression was related to well-differentiated gastric tumors, whereas underexpression was linked to moderate or poorly differentiated gastric tumors (P < 0.001). EGFR protein expression was high (IHC 2+ and 3+) in 29.4% of gastric tumors and was normal or low (score 0 to 1+) in 70.6% cases. EGFR expression, in both mRNA and protein, was not related to any EGFR polymorphism (P > 0.05). CONCLUSIONS: Most gastric tumors showed low EGFR expression (mRNA and protein), whereas EGFR overexpression was related to well-differentiated gastric tumors. Furthermore, germinal polymorphisms -216, -191, (CA) n IVS1, and R521K were not related to EGFR expression (mRNA or protein).

EGFR gene polymorphisms -216G>T and -191C>A are risk markers for gastric cancer in Mexican population.

Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein with tyrosine-kinase activity that plays an important role in multiple cellular functions. EGFR overexpression has been observed in several types of tumors and it is significantly associated with disease stage, survival, prognosis, and progression of cancer. The polymorphisms -216G>T, -191C>A, and (CA)n first intervening sequence (IVS1) have been related to EGFR overexpression and have been studied in several types of cancer, but not in gastric cancer (GC). The aim of this study was to determine the association of these 3 polymorphisms and GC. Genomic DNA from 68 GC patients and 102 healthy blood donors were analyzed. Polymorphisms were identified by DNA-sequencing (-216G>T and -191C>A) and GeneScan (CA)n IVS1. The results showed that the distribution of the -216G>T and -191C>A genotypes differed between groups (P < 0.05). The odds ratio for the -216TT genotype was 4.59 (95% confidence interval = 1.55-13.54, P < 0.05) and 10.71 (95% confidence interval = 2.31-49.59, P < 0.05) for the -191AA genotype, both in a recessive model. The genotype and allele distributions of the (CA)n IVS1 repeat was similar in both groups. In conclusion, the -216TT and -191AA genotypes and GA haplotype of the EGFR gene were found to be associated with an increased risk of gastric cancer in a Mexican population.