ABCG2 Gene and ABCG2 Protein Expression in Colorectal Cancer-In Silico and Wet Analysis.

ABCG2 (ATP-binding cassette superfamily G member 2) is a cell membrane pump encoded by the ABCG2 gene. ABCG2 can protect cells against compounds initiating and/or intensifying neoplasia and is considered a marker of stem cells responsible for cancer growth, drug resistance and recurrence. Expression of the ABCG2 gene or its protein has been shown to be a negative prognostic factor in various malignancies. However, its prognostic significance in colorectal cancer remains unclear. Using publicly available data, ABCG2 was shown to be underexpressed in colon and rectum adenocarcinomas, with lower expression compared to both the adjacent nonmalignant lung tissues and non-tumour lung tissues of healthy individuals. This downregulation could result from the methylation level of some sites of the ABCG2 gene. This was connected with microsatellite instability, weight and age among patients with colon adenocarcinoma, and with tumour localization, population type and age of patients for rectum adenocarcinoma. No association was found between ABCG2 expression level and survival of colorectal cancer patients. In wet analysis of colorectal cancer samples, neither ABCG2 gene expression, analysed by RT-PCR, nor ABCG2 protein level, assessed by immunohistochemistry, was associated with any clinicopathological factors or overall survival. An ABCG2-centered protein-protein interaction network build by STRING showed proteins were found to be involved in leukotriene, organic anion and xenobiotic transport, endodermal cell fate specification, and histone methylation and ubiquitination. Hence, ABCG2 underexpression could be an indicator of the activity of certain signalling pathways or protein interactors essential for colorectal carcinogenesis.

The Interaction between Four Polymorphisms and Haplotype of ABCB1, the Risk of Non-Small Cell Lung Cancer, and the Disease Phenotype.

P-glycoprotein, product of the ABCB1 (ATP binding cassette subfamily B member 1) gene, has been reported to play an important role in multiple drug resistance during cancer therapy. However, its influence on non-small cell lung cancer (NSCLC) risk has not been clearly defined. The aim of the present study was to examine the association between clinicopathological factors and SNPs T-129C, C1236T, G2677T/A, and C3435T, as well as its haplotype, and to investigate the role of ABCB1 polymorphisms in NSCLC development. The study included 80 patients who suffered from NSCLC and underwent surgery to remove the tumour and 96 healthy controls. The tissues were genotyped by PCR-RFLP and sequencing methods, and the haplotype frequencies in both groups were estimated. The SNP C3435T was identified as a NSCLC risk factor. The presence of mutated allelic variant T (p=0.0103) or homozygote TT (p=0.0099) was observed significantly more often in cancer patients than in healthy controls. The two groups also demonstrated a highly significant difference in common haplotype frequency (p=0.01). The T-129-T1236-T2677-T3435 haplotype was found to be most closely associated with NSCLC risk. Although the investigated polymorphisms were not related to demographic features, clinicopathological lung tumour characteristics, or blood morphology indices, marginally significant correlations were found with some variables: C1236T with age of disease onset (p=0.0410); C3435T with smoking status (p=0.0561). As the findings indicate, lung cancer and control groups demonstrate significantly different patterns of -129/1236/2677/3435 haplotype distribution; T-T-T-T haplotype contributes to NSCLC susceptibility, and this effect is probably mainly dependent on C3435T. So far, similar studies were published in other populations.

Importance of selected ABCB1 SNPs for the level of severity of depressive symptoms and effectiveness of recurrent depressive disorder therapy.

The expression level of mRNA and also the function of P-gp are strictly connected with the polymorphic nature of the ABCB1 gene. In this study, we evaluated the association between promoter SNP, i.e. T-129C, three other SNPs investigated earlier and ABCB1 expression in the depression group. To assess the additive significance of these SNPs on clinicopathological features a mathematical model was also built. 102 patients suffering from recurrent depressive disorder (rDD) and 94 healthy individuals from a local blood bank were enrolled in this study. ABCB1 gene polymorphism was identified by the RFLP method. The relative level of ABCB1 expression was measured by real-time PCR. For SNP T-129C no statistically significant differences in allele and genotype frequencies between depression and control groups were found (p = 0.3176). There was no statistically significant association between the expression value and 4 studied SNPs in ABCB1 (T-129C, C1236T, G2677T/A and C3435T) or the investigated clinicopathological features. Furthermore, a correlation between the initial HDRS score (lower than 23) and presence of at least 1236 T allele was observed, in particular in combination with 3435 T or 2677 T/A. Mutated allele of each SNP was also significantly associated with declined response to antidepressant therapy, both individually and in combination with others. Results of this study suggest that T-129C does not play an important role in the rDD development. The influence of the studied SNPs on ABCB1 gene expression is still unknown. However, the additive impact of 3 most frequently studied SNPs of ABCB1 on the course of depression and effectiveness of its treatment was confirmed.

HMGA1 gene expression level in cancer tissue and blood samples of non-small cell lung cancer (NSCLC) patients: preliminary report.

The study aimed to assess the HMGA1 gene expression level in NSCLC patients and to evaluate its association with selected clinicopathological features and overall survival of patients. The expression of the HMGA1, coding non-histone transcription regulator HMGA1, was previously proved to correlate with the ability of cancer cells to metastasize the advancement of the disease. The prognostic value of the HMGA1 expression level was demonstrated in some neoplasms, e.g., pancreatic, gastric, endometrial, hepatocellular cancer, but the knowledge about its role in non-small cell lung cancer (NSCLC) is still limited. Thus, the HMGA1 expression level was evaluated by real-time PCR method in postoperative tumor tissue and blood samples collected at the time of diagnosis, 100 days and 1 year after surgery from 47 NSCLC patients. Mean HMGA1 expression level in blood decreased systematically from the time of cancer diagnosis to 1 year after surgery. The blood HMGA1 expression level 1 year after surgery was associated with the tobacco smoking status of patients (p= 0.0230). Patients with high blood HMGA1 expression levels measured 100 days after surgery tend to have worse overall survival than those with low expression levels (p= 0.1197). Tumor HMGA1 expression level was associated with neither features nor the overall survival of NSCLC patients. Moreover, no correlation between HMGA1 expression level measured in tumor tissue and blood samples was stated. Blood HMGA1 mRNA level could be a promising factor in the prognostication of non-small cell lung cancer patients.

Prognostic Significance of HMGA1 Expression in Lung Cancer Based on Bioinformatics Analysis.

High-mobility group protein 1 (HMGA1) participates in the processes of DNA transcription, replication, recombination, and repair. The HMGA1 gene is expressed abundantly during embryogenesis and is reactivated during carcinogenesis. HMGA1 gene expression has been associated with a high degree of malignancy, metastatic tendency, and poor survival in breast, colon, ovary, and pancreatic cancers. However, its prognostic significance in lung cancer remains unclear. Using publicly available data, HMGA1 was shown to be overexpressed in both small and non-small lung tumors, with higher expression compared to both the adjacent non-malignant lung tissues and non-tumor lung tissues of healthy individuals. Elevated HMGA1 expression could result from lowered HMGA1 methylation and was connected with some clinicopathological features like sex, age, and stage of the disease. The high HMGA1 expression level was connected with shorter overall and first progression survival time among lung adenocarcinoma patients, but not lung squamous cell carcinoma patients. HMGA1 could interact with proteins involved in cellular senescence and cell cycle control (TP53, RB1, RPS6KB1, and CDK1), transcription regulation (EP400 and HMGA2), chromatin assembly and remodeling (LMNB1), and cholesterol and isoprene biosynthesis (HMGCR and INSIG1). Taken together, HMGA1 overexpression could be an essential element of lung carcinogenesis and a prognostic feature in lung cancer.

Association between the CEBPA and c-MYC genes expression levels and acute myeloid leukemia pathogenesis and development.

CEBPA and c-MYC genes belong to TF and play an essential role in hematologic malignancies development. Furthermore, these genes also co-regulate with RUNX1 and lead to bone marrow differentiation and may contribute to the leukemic transformation. Understanding the function and full characteristics of selected genes in the group of patients with AML can be helpful in assessing prognosis, and their usefulness as prognostic factors can be revealed. The aim of the study was to evaluate CEBPA and c-MYC mRNA expression level and to seek their association with demographical and clinical features of AML patients such as: age, gender, FAB classification, mortality or leukemia cell karyotype. Obtained results were also correlated with the expression level of the RUNX gene family. To assess of relative gene expression level the qPCR method was used. The expression levels of CEBPA and c-MYC gene varied among patients. Neither CEBPA nor c-MYC expression levels differed significantly between women and men (p=0.8325 and p=0.1698, respectively). No statistically significant correlation between age at the time of diagnosis and expression of CEBPA (p=0.4314) or c-MYC (p=0.9524) was stated. There were no significant associations between relative CEBPA (p=0.4247) or c-MYC (p=0.4655) expression level and FAB subtype and mortality among the enrolled patients (p=0.5858 and p=0.8437, respectively). However, it was observed that c-MYC and RUNX1 expression levels were significantly positively correlated (rS=0.328, p=0.0411). Overall, AML pathogenesis involves a complex interaction among CEBPA, c-MYC and RUNX family genes.

NFKB2 gene expression in patients with peptic ulcer diseases and gastric cancer.

Gastric cancer is one of the most common worldwide types of cancer. It is a multifactorial disease and both environmental and genetic factors play an important role in its etiology. Evaluation of the relative expression level of NFKB2 gene in two groups of patients: peptic ulcer and gastric cancer and its role in the pathomechanism of these diseases was the aim of this study. RNA was isolated from: 79 samples of peptic ulcer, 22 gastric cancer and 11 control tissue. The real-time PCR technique was used to study the expression of NFKB2 gene. The relative expression level of NFKB2 gene was a variable in all three studied groups. The relative NFKB2 gene expression depends on the type of a disease. Peptic ulcer cases showed the increased relative NFKB2 gene expression to control group (p = 0.0000). Cancer cases presented decreased relative NFKB2 gene expression to normal stomach tissue (p = 0.0183). There are statistically important differences in the investigated gene expression between peptic ulcer, where the expression level is higher comparing to gastric cancer and control tissue which confirmed that such an activation is connected with an inflammatory process. The relative expression level of NFKB2 is decreased in cancer cases as opposed to control tissue and peptic ulcer cases which could suggest that during carcinogenesis of gastric cancer inhibition of NF-kB pathway takes place which could be a promising factor for patients.

CYP2C19*2 polymorphism in Polish peptic ulcer patients.

BACKGROUND: CYP2C19 isoenzyme of cytochrome P450 in the liver catabolises proton pump inhibitors, one of the therapeutics utilized in Helicobacter pylori eradication therapy, and in this way could influence the eradication effectiveness. The isoensyme contributes also to metabolism of endogenous substances, which derivatives are involved in the pathogenesis of peptic ulceration. CYP2C19*2 polymorphism (rs4244285) changing the CYP2C19 function could be relevant in the predisposition to peptic ulcer disease. METHODS: CYP2C19*2 polymorphism in 197 peptic ulcer patients and 107 healthy subjects of Polish origin by PCR-RFLP method was investigated. RESULTS: There were no statistically significant differences in genotypes and alleles frequencies for investigated polymorphism between peptic ulcer patients and healthy individuals. No associations between frequencies of particular CYP2C19 genotypes and alleles and the presence of H. pylori infection in peptic ulcer patients were stated. However, significant association between CYP2C19*2 and gender in H. pylori-infected but not -uninfected peptic ulcer individuals was found. CONCLUSIONS: Investigated polymorphism is not a risk factor for peptic ulcer in Polish population. Obtained results could suggested there is some interaction between gender, CYP2C19*2 polymorphism, and pathogenesis of H. pylori infection development. However, this hypothesis should be verified in the further studies.

SMAD-4 gene expression in human colorectal cancer: Comparison with some clinical and pathological parameters.

The aim of this study was to evaluate the expression of SMAD-4 gene in cases of colorectal cancer and to link the obtained data with the development of this disease. SMAD-4 gene is responsible for the control of many important cellular processes, for example prevention of excessive epithelial cell growth and divisions. This suppressor gene is located on chromosome 18 within the region with frequent genetic losses in colorectal cancer. Inactivation of this gene is commonly found in pancreatic cancer where the SMAD-4 gene lost in the expression has been associated with a poor prognosis in this cancer. However, the role of SMAD-4 gene in other cancers has not been completely explained, therefore in the present study we tried to find the role of this gene in colon cancer. The relative expression level of SMAD-4 gene was determined by real-time PCR for 80 cases of colorectal cancer. The obtained results for SMAD-4 expression were compared with many clinical and pathological variables (such as the size and depth of primary tumour penetration, presence of the metastases, stage of cancer, histological grade or overall survival). It was found that the level of SMAD-4 gene expression was not associated with the analyzed parameters of clinical staging. The lack of dependence can be caused by slight differences within the study group in view of parameters correlated with invasive colon cancer. Further analysis in this direction is needed.

Assessment of TNFA polymorphisms at positions -857 and -863 in Polish peptic ulcer patients.

PURPOSE: Peptic ulceration connected with chronic inflammation in gastrointestinal mucosa could be induced by Helicobacter pylori infection. Tumor necrosis factor alpha (TNF-α) encoded by TNFA gene is a key mediator in the inflammation process. There are several polymorphisms in the promoter of TNFA influencing its transcriptional activity. -857C>T (rs1799724) and -863C>A (rs1800630) substitutions may be responsible for increased TNFA transcription and TNF-α production. The association of these two polymorphisms with peptic ulceration and the development of H. pylori infection in peptic ulcer patients in Poles were evaluated. MATERIAL AND METHODS: Polymorphisms were assessed by PCR-RFLP in 203 peptic ulcer patients. H. pylori infection was confirmed by rapid urease test. The results of genotyping were compared with those obtained for 248 healthy Polish individuals. RESULTS: There were no significant differences in genotype and allele frequencies for both investigated polymorphisms between peptic ulcer patients and healthy individuals. No associations between frequencies of particular genotypes and alleles for both SNPs and the presence of H. pylori infection in peptic ulcer patients and in subgroups of peptic ulcer women and men were confirmed. CONCLUSIONS: The investigated SNPs are not risk factors for peptic ulcer development. They are not risk factors for H. pylori infection in ulcer patients.

ABCG2 in peptic ulcer: gene expression and mutation analysis.

The aim of this study was to evaluate the participation of polymorphism at position C421A and mRNA expression of the ABCG2 gene in the development of peptic ulcers, which is a very common and severe disease. ABCG2, encoded by the ABCG2 gene, has been found inter alia in the gastrointestinal tract, where it plays a protective role eliminating xenobiotics from cells into the extracellular environment. The materials for the study were biopsies of gastric mucosa taken during a routine endoscopy. For genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) at position C421A, DNA was isolated from 201 samples, while for the mRNA expression level by real-time PCR, RNA was isolated from 60 patients. The control group of healthy individuals consisted of 97 blood donors. The dominant genotype in the group of peptic ulcer patients and healthy individuals was homozygous CC. No statistically significant differences between healthy individuals and the whole group of peptic ulcer patients and, likewise, between the subgroups of peptic ulcer patients (infected and uninfected with Helicobacter pylori) were found. ABCG2 expression relative to GAPDH expression was found in 38 of the 60 gastric mucosa samples. The expression level of the gene varies greatly among cases. The statistically significant differences between the intensity (p = 0.0375) of H. pylori infection and ABCG2 gene expression have been shown. It was observed that the more intense the infection, the higher the level of ABCG2 expression.