The Influence of C3435T Polymorphism of the ABCB1 Gene on Genetic Susceptibility to Depression and Treatment Response in Polish Population - Preliminary Report.

BACKGROUND: Despite the high prevalence of depression, the mechanism of the origin of this disease as well as the causes of resistance to therapy in some patients are still not fully understood. Increasingly, the possible role of genetic factors is considered. One of them is polymorphisms in the ABCB1 (MDR1) gene which encodes P-glycoprotein, responsible for the transport of xenobiotics, including antidepressant drugs, through the blood-brain barrier. METHODS: C3435T was evaluated in 90 patients with recurrent depressive disorders (rDD). Genotyping was performed using a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: The obtained results indicate that the TT genotype occurred more frequently among patients with rDD than in healthy volunteers (p=0.0441). Also, at least one C allele was present significantly less frequent in the study group than in healthy individuals (p=0.0300). The severity of depressive symptoms was higher among patient with the CC genotype in comparison with the other genotypes (p=0.0106) but treatment response to antidepressants was better in this group than among patients with CT or TT genotypes (p=0.0301). Likewise, patients with the T allele have a significantly lower severity of symptoms (p=0.0026) and decreased therapy effectiveness (p=0.0142) than C allele carriers. CONCLUSIONS: This study suggests that C3435T polymorphisms in the ABCB1 gene are strongly associated with a predisposition to depression development, the severity of depressive symptoms and the effectiveness of therapy with using different groups of antidepressant agents.

[Characterisation of selected molecular mechanisms influencing pharmacokinetics and pharmacodynamics of antidepressants]. / Charakterystyka wybranych mechanizmów molekularnych wplywajacych na farmakokinetyke i farmakodynamike leków przeciwdepresyjnych.

Over 350 millions of people suffer from depression worldwide, and an increase in the incidence of the disease is expected in the coming years. Therefore, there is a strong need of knowing the mechanisms of development this disease and its effective treatment. Pharmacological therapy is an essential element of antidepressant therapy and its failure is a serious problem in clinical psychiatry. In spite of large number of available medicines, only 50% of patients achieved remission after single-drug treatment. Genetic factors which predispose to depression development and predict an outcome of its pharmacotherapy, probably play a substantial role in these phenomena. In spite of this, they are still not characterized enough and applied in practice. Therefore, the aim of this study is to present the current knowledge of the impact of selected genes on pharmacokinetics and pharmacodynamics of antidepressants by changing function and/or structure of encoded proteins. In the review the best known polymorphisms of selected genes encoding isoenzymes of cytochrome P-450, responsible for metabolism of popular antidepressant drugs, namely CYP2C19, CYP2D6, CYP1A2, and CYP3A4/5 are described. Further, 4 polymorphisms of ABCB1 gene (rs 1045642, rs 2032582, rs 1128503 and rs 2032583) encoding glycoprotein P, which play a key role in transportation of large number of drugs used in treatment of depression. For benefit of treatment of patients with depression, it is worthy to estimate and to take on the board all so far known mechanisms of planning therapy.

Quantitative analysis of FJ 194940.1 gene expression in colon cancer and its association with clinicopathological parameters.

AIM OF THE STUDY: The FJ 194940.1 gene is located on chromosome 1 and consists of 6 exons and 5 introns. The gene undergoes alternative splicing and its isoforms appear during cancer development. Evidence suggests that expression of FJ 194940.1 splice variants relate to colorectal cancer progression. This paper discusses the quantitative analysis of the exon V expression level of FJ 194940.1 in colon cancer. The aim of the study is to carry out quantitative analysis by real-time PCR in a series of 102 colon cancer samples that had previously shown presence of exon V expression. To compare the exon V expression level with certain histological parameters and clinical staging of the neoplasm in order to assess its potential role as a prognostic factor in colon cancer. MATERIAL AND METHODS: Tissue specimens of colorectal cancer were obtained from the Oncological Centre of Lodz, Poland.Total RNA isolation was performed in accordance with the protocol enclosed in the Total RNA Prep Plus Minicolumn Kit (A&A Biotechnology, Poland). Reverse Transcriptase-PCR reaction was carried out using Enhanced Avian HSRT-PCR Kit, Sigma, according to the manufacturer's protocol.. Presence of cDNA in each sample was checked by PCR amplification of ß-actin. Only samples showing the PCR product of this housekeeping gene were included in further tests. The amount of FJ 194940.1 transcript containing exon V was analysed by means of real-time PCR. RESULTS: Exon V expression level is not significantly related to any clinicopathological features in colon cancer. However, there was a tendency towards a lower exon V expression level in a group of cases where vessel invasion was present (p = 0.0697). Additionally, the risk of death in patients with a low exon V expression level was more than two times higher when compared to patients with a high exon V expression level. CONCLUSIONS: FJ 194940.1 gene expression correlates with cancer progression independently of analysed clinicopathological parameters.

Investigation of ABCB1 1236 and 2677 SNPs in patients with peptic ulcer.

OBJECTIVE: P-gp, encoded by ABCB1 gene, is an ATP-binding membrane pump, which exports substrates from the cell including drugs and xenobiotics. Changes in the function of P-gp as a result of polymorphism could have an impact in some diseases' risks and treatment outcomes. The aim of the study was to determine the significance of the ABCB1 gene SNPs: 1236 and 2677 for peptic ulcer risk and development of Helicobacter pylori infection in peptic ulcer patients. MATERIAL AND METHODS: One hundred and ninety-five biopsy specimens obtained from peptic ulcer patients (investigated group) were genotyped using sequencing for common SNPs of ABCB1: 1236 and 2677. Genotyping data were compared with the results from healthy subjects (control) and with the presence of H. pylori infection, which was estimated by urease test. RESULTS: No statistically significant difference in frequency of genotypes and alleles for the SNPs were found between the investigated group and the control. However, in the peptic ulcer patients, mutant TT homozygotes and those who carried at least one allele T for the polymorphisms 1236 and 2677 were observed more frequently than the control group. In the peptic ulcer group, there were no significant dependences between the presence of H. pylori infection and the investigated polymorphisms other than more frequent occurrence of TT 1236 homozygous in the group of infected women (p = 0.0298). CONCLUSIONS: The TT genotype and the mutated allele T for the polymorphisms 1236 and 2677 could increase peptic ulcer risk. ABCB1 1236 polymorphism may also be associated with an increased likelihood of H. pylori infection development, especially in women.

ABCB1/MDR1 gene polymorphisms as a prognostic factor in colorectal cancer.

OBJECTIVE: To analyse the single-nucleotide polymorphisms (SNPs): ABCB1(1236C>T), ABCB1(2677G>T/A), ABCB1(3435C>T) and haplotypes in the ABCB1/MDR1 gene, which could contribute to genetic risk of colorectal cancer (CRC). Disease association between the ABCB1/MDR1 genotype, allele, haplotype frequencies and histological features, such as TNM classification, localization of primary carcinoma, grade of malignancy, histological type of tumour, lymphoid infiltration and vessel invasion were estimated. In this study, the potential role of SNPs of the ABCB1/MDR1 gene as a prognostic marker for CRC was analysed. MATERIALS AND METHODS: Tumour specimens of 95 patients with CRC were studied. Using automated sequencing or PCR-RFLP method, DNA for three common SNPs of ABCB1/MDR1 was extracted and analysed. The results of genotyping and haplotype analysis with histopathological features, grading and clinical staging of neoplasms were correlated. RESULTS: A statistically significant higher frequency of T(1236) allele in T1/T2 (89.7%), M0 groups (81.6%) and I/II clinical staging (82.7%) in comparison with T3/T4 (68.2%), M1 groups (47.4%) and III/IV clinical staging (65.1%) was detected. Furthermore, multivariate analysis according to Cox's proportional hazard model indicated that the T(1236) allele is a good, independent prognostic factor and the presence of this allele decreases the risk of death in comparison with a group without this allele (HR = 0.26; p = 0.0424). In addition, a statistically significant higher frequency of C(3435) allele and significant differences in the C(3435) allele distribution in N1/N2 group (91.7% and 62.5%, respectively) than N0 group (71.2% and 44.9%, respectively) was found. Each of the eight possible haplotypes was noted in M0 or I/II group and only seven in M1 or III/IV group. Haplotype T(1236)-G(2677)-C(3435) only in less advanced CRC subjects (9.6% in I/II and 9.2% in M0 group) was detected. In addition, significant differences in haplotype distributions between M0 or I/II and M1 or III/IV group were found (p = 0.01 and p = 0.05, respectively). CONCLUSIONS: These results suggest association between T(1236) allele and T(1236)-G(2677)-C(3435) haplotype and less advanced CRC, so these genetic markers may play a role as potentially good prognostic factors. Differences in haplotype distributions and degree of clinical staging may suggest that some other potential SNPs, especially in regulatory region of ABCB1/MDR1 gene, may influence P-glycoprotein function and CRC progression.

[MDR1 (ABCB1) gene encoding glycoprotein P (P-gp), a member of ABC transporter superfamily: consequences for therapy and progression of neoplastic diseases]. / Gen MDR1 (ABCB1) kodujacy glikoproteine P (P-gp) z rodziny transporterów blonowych Abc: znaczenie dla terapii i rozwoju nowotworów.

Glycoprotein P (P-gp) is a membrane protein belonging to the ABC transporter superfamily. As ATP-dependent pump it extrudes lipophilic particles out of the cell. P-gp was discovered in Chinese hamster ovary cells (CHO) where causing resistance to anticancer drugs. In a physiological state it is present in secretory organs and contribute to tissue barriers. P-gp transports wide variety of structurally diverse compounds including many anticancer drugs. Both environmental factors and mutations of the MDR1 gene may influence P-gp synthesis level. Linkage disequilibrium between single nucleotide polymorphisms (SNPs) of the MDR1 gene results from joint inheritance of these SNPs comprised in one haplotype. MDR1 polymorphism could affect the bioavailability of drugs which are P-gp substrates and thus influence the effectiveness of pharamacotherapy. Furthermore, P-gp protects organism against cancerogenic and toxic substances contained in the food and urine. A change in P-gp expression level or its activity is a putative cause of neoplastic disorders.

Investigation of -308G>A and -1031T>C polymorphisms in the TNFA promoter region in Polish peptic ulcer patients.

BACKGROUND/AIMS: Tumor necrosis factor α (TNF-α) encoded by TNFA is a key mediator in inflammation, a precursor condition for peptic ulceration. Promoter polymorphisms of TNFA that influence its transcriptional activity and TNF-α production are known. TNFA-308G>A (rs1800629) and TNFA-1031T>C (rs1799964), which are responsible for increased TNFA transcription, could influence the risk of peptic ulceration. This study aimed to investigate these polymorphisms and to evaluate their association with peptic ulcer disease and Helicobacter pylori infection in the Polish population. METHODS: Gastric mucosa specimens obtained from 177 Polish peptic ulcer patients were used to conduct rapid urease tests and to assess the investigated polymorphisms by polymerase chain reaction-restriction fragment length polymorphism. Genotyping data were compared with the results obtained from healthy individuals of Polish origin. RESULTS: There were no significant differences in genotype and allele frequency of the investigated polymorphisms between peptic ulcer patients and healthy individuals. No associations between the frequencies of particular genotypes and alleles for both single-nucleotide polymorphisms (SNPs) and the presence of H. pylori infection in peptic ulcer patients and in subgroups of men and women with peptic ulcer disease were found. CONCLUSIONS: The investigated SNPs are not risk factors for either peptic ulcer or H. pylori infection development in the Polish population. The results require verification in a larger cohort.

ABCB1 expression in peptic ulcer patients and its connection with H. pylori Infection.

Glycoprotein P, encoded by the ABCB1 gene, plays an important role in gastric mucosa homeostasis and can influence the eradication therapy outcome in H. pylori-infected individuals. In the study we examined the ABCB1 expression level in 128 peptic ulcer patients by real-time PCR. There was no correlation between gene expression and the presence of H. pylori or the H. pylori infection intensity. The expression level did not differ between women and men. However, the levels were higher in patients who were over 54 years old than those who were aged up to 54 years old. As ABCB1 expression is largely determined by genetic polymorphisms, in the future, expression data will be related to the patients' ABCB1 genotypes.

Investigation of FJ 194940.1 gene alternative splicing in colon cancer and its association with clinicopathological parameters.

Colorectal cancer (CRC) is one of the most frequent neoplasms and is responsible for the second highest mortality rate of all cancers in the more developed regions of the world. The molecular mechanisms of CRC are relatively well characterized and are correlated to the accumulation of genetic mutations and certain patterns of gene expression/over-expression. There are a number of possible molecular factors involved in CRC progression in the aforementioned pathways, which are as yet not well described. One of these factors appears to be the gene FJ 194940.1, previously termed P65. FJ 194940.1 consists of 6 exons and probably undergoes alternative splicing in malignant tissues. In this study, tissue samples from 102 patients with colon cancer were investigated to confirm alternative splicing and to correlate results obtained with clinicopathological parameters. A total of 18 splice variants, which arise from various combinations of 4 exons (II, III, IV and V) and exon-exon junctions between exons 1 and 2 (I/II); 2 and 3 (II/III); 3 and 4 (III/IV), as well as 4 and 5 (IV/V), were found. For statistical analysis the full length transcript was divided into parts A and B. Part A consisted of exons II and III, as well as I/II and II/III exon-exon junctions, whereas part B comprised exons IV and V, as well as III/IV and IV/V exon-exon junctions. The expression of part B of the FJ 194940.1 gene transcript is correlated with well-differentiated (G1) and moderately differentiated cases (G2). Lymphocytic tumor infiltration, a good prognostic factor in CRC, was significantly correlated to the presence of all elements in part A of the FJ 194940.1 gene transcript. Patients who had all elements in part A of the transcript survived for a shorter duration. Investigation of the FJ 194940.1 gene revealed that the gene had undergone alternative splicing. However, the role of its transcripts and potential proteins should be examined in detail.

Apoptotic gene expression under influence of fludarabine and cladribine in chronic lymphocytic leukemia-microarray study.

BACKGROUND: A deep insight into gene expression profiling (GEP) is a key to understanding the background of disease. It can lead to identification of diagnostic and prognostic factors and then to a selection of the most appropriate therapy. The aim of this study was to evaluate differences in apoptotic gene expression in chronic lymphocytic leukemia (CLL) cells influenced by fludarabine (FA) or cladribine (2-CdA). METHODS: GEP was performed in cells obtained from 10 untreated CLL patients and cultured in vitro with FA or 2-CdA. Ninety-three selected apoptotic genes were analyzed using 384 TaqMan® Low Density Arrays in pooled RNA. RESULTS: Relevant results were found in a set of 27 genes, however, the most striking differences between FA and 2-CdA were observed in the following 5 genes: BAD, TNFRSF21, DAPK1, CARD 6 and CARD 9. CONCLUSION: We have found some differences in apoptotic gene expression between FAand 2-CdA. These findings give prominence to genes qualifying for further studies currently conducted in our Department.

Changes in the apoptotic gene expression profile in CLL patients treated with rituximab combined with cladribine and cyclophosphamide-preliminary results.

The study was aimed to investigate modifications of apoptotic gene expression profile by microarray technique in 10 patients with chronic lymphocytic leukemia by treatment with rituximab, cladribine and cyclophosphamide (RCC) according to IGHV mutational status. The TaqMan Low Density Array for 96 gene transcripts was used. Those modifications followed two distinctive patterns largely overlapping the IGHV mutational status. In the IGHV-mutated group, the expression of many proapoptotic genes increased after treatment as compared to initial value. Our results suggest that RCC drugs may act through influence on the expression of some apoptosis-involved genes dependently on the IGVH mutational status.

C3435T polymorphism of the ABCB1 gene: impact on genetic susceptibility to peptic ulcers.

The functional single nucleotide polymorphism (SNP) C3435T in exon 26 of the ABCB1 gene encoding the xenobiotic transporter P-glycoprotein (P-gp) may influence susceptibility to several diseases, as well as the clinical outcome of treatment with P-gp substrates. Exposure to environmental chemicals is thought to be involved in peptic ulcer pathogenesis and then later in stomach cancer development. About 80% of ulcers are associated with Helicobacter pylori infection, one of the risk factors of stomach cancer. P-gp-transported drugs are used in treatment of H. pylori. Therefore, a lack of effectiveness in eradication therapy can lead to chronic stomach inflammation and promote cancerogenesis. In this study, 196 patients with peptic ulcers divided into two groups with and without H. pylori infection and combined with 96 healthy controls were genotyped for the ABCB1 C3435T SNP. A trend towards higher incidence of the 3435TT genotype among peptic ulcer patients than in controls (p = 0.0983) was observed. Likewise, the 3435T allele was more frequent in groups suffering from peptic ulcers. The association was near to statistical significance (p = 0.0538). Between analyzed genotypes and H. pylori infection, statistically significant dependence was found (p = 0.0372). In addition, the CT genotype was associated with 1.56 times and the TT with 2.45 times higher prevalence of infection compared to the CC genotype. Asimilar association was present in a subgroup of peptic ulcer men (p = 0.0090). The isolated C3435T ABCB1 SNP is not a major factor for genetic susceptibility to peptic ulcer, but in a group of men who suffered from peptic ulcer, this polymorphism seemed to be a risk factor for H. pylori infection development.

Polymorphisms and haplotypes in the multidrug resistance 1 gene (MDR1/ABCB1) and risk of multiple myeloma.

MDR1(ABCB1) gene encodes for P-glycoprotein (P-gp, MDR1, ABCB1), an ATP-binding cassette superfamily member involved in the transport of xenobiotics. Here, we investigated whether common MDR1 single nucleotide polymorphisms (1236C>T, 2677G>A/T and 3435C>T) affect predisposition to multiple myeloma. Genotyping was performed in 111 myeloma patients and 96 controls by PCR-based assays. Haplotypes were inferred using PHASE algorithm. We found comparable allele and genotype frequencies among myeloma patients and controls. Moreover, patient and control groups did not differ regarding MDR1 haplotype distribution (p=0.18). In conclusion, our results do not support major influence of MDR1 variants on the risk of myeloma in Caucasians.