Clinical Correlates of the NR3C1 Gene Methylation at Various Stages of Psychosis.

BACKGROUND: Dysregulation of epigenetic processes might account for alterations of the hypothalamic-pituitary-adrenal axis observed in patients with schizophrenia. Therefore, in this study, we aimed to investigate methylation of the glucocorticoid receptor (NR3C1) gene in patients with schizophrenia-spectrum disorders, individuals at familial high risk of schizophrenia (FHR-P), and healthy controls with respect to clinical manifestation and a history of psychosocial stressors. METHODS: We recruited 40 first-episode psychosis patients, 45 acutely relapsed schizophrenia (SCZ-AR) patients, 39 FHR-P individuals, and 56 healthy controls. The level of methylation at 9 CpG sites of the NR3C1 gene was determined using pyrosequencing. RESULTS: The level of NR3C1 methylation was significantly lower in first-episode psychosis patients and significantly higher in SCZ-AR patients compared with other subgroups of participants. Individuals with FHR-P and healthy controls had similar levels of NR3C1 methylation. A history of adverse childhood experiences was associated with significantly lower NR3C1 methylation in all subgroups of participants. Higher methylation of the NR3C1 gene was related to worse performance of attention and immediate memory as well as lower level of general functioning in patients with psychosis. CONCLUSIONS: Patients with schizophrenia-spectrum disorders show altered levels of NR3C1 methylation that are significantly lower in first-episode psychosis patients and significantly higher in SCZ-AR patients. Higher methylation of the NR3C1 gene might be related to cognitive impairment observed in this clinical population. The association between a history of adverse childhood experiences and lower NR3C1 methylation is not specific to patients with psychosis. Longitudinal studies are needed to establish causal mechanisms underlying these observations.

Novel de novo mutation affecting two adjacent aminoacids in the EED gene in a patient with Weaver syndrome.

Overgrowth, macrocephaly, accelerated osseous maturation, variable intellectual disability, and characteristic facial features are the main symptoms of Weaver syndrome, a rare condition caused by mutations in EZH2 gene. Recently, in four patients with Weaver-like symptoms without mutations in EZH2 gene, pathogenic variants in EED were described. We present another patient clinically diagnosed with Weaver syndrome in whom WES revealed an EED de novo mutation affecting two neighboring aminoacids, NM_003797.3:c.917_919delinsCGG/p.(Arg306_Asn307delinsThrAsp) located in one allele (in cis). Our observation, together with previous reports suggests that EED gene testing is warranted in patients with the overgrowth syndrome features and suspicion of Weaver syndrome with normal results of EZH2 gene sequencing.

Genetic Variation in One-Carbon Metabolism and Changes in Metabolic Parameters in First-Episode Schizophrenia Patients.

Background: In this study, we aimed to investigate the effects of polymorphisms in genes encoding 1-carbon metabolism enzymes on differential development of metabolic parameters during 12 weeks of treatment with second-generation antipsychotics in first-episode schizophrenia patients. Methods: The following polymorphisms in 1-carbon metabolism genes were genotyped: MTHFR (C677T and A1298C), MTHFD1 (G1958A), MTRR (A66G), and BHMT (G742A). A broad panel of metabolic parameters including body mass index, waist circumference, total cholesterol low and high density lipoproteins, triglycerides, homocysteine, folate, and vitamin B12 was determined. Results: There was a significant effect of the interaction between the MTHFR C677T polymorphism and time on body mass index and waist circumference in the allelic and genotype analyses. Indeed, patients with the MTHFR 677CC genotype had higher increase in body mass index and waist circumference compared with other corresponding genotypes or the MTHFR 677T allele carriers (CT and TT genotypes). In addition, patients with the MTHFR 677TT genotype had higher waist circumference in all time points. Similarly, patients with the MTHFR 677TT genotype had higher body mass index in all time points, but this effect was not significant after correction for multiple testing. Conclusions: Our results indicate that the MTHFR C677T polymorphism may predict antipsychotic-induced weight gain. Effects of the MTHFR C677T polymorphism might be different in initial exposure to antipsychotics compared with long-term perspective.

Further evidence for GRIN2B mutation as the cause of severe epileptic encephalopathy.

Epileptic encephalopathies (EE) include a range of severe epilepsies in which intractable seizures or severe sub-clinical epileptiform activity are accompanied by impairment of motor and cognitive functions. Mutations in several genes including ion channels and other genes whose function is not completely understood have been associated to some EE. In this report, we provide a detailed clinical description of a sporadic male patient with early-onset epilepsy and epileptic encephalopathy in whom we performed complete exome sequencing (WES) and identified a GRIN2B mutation. The GRIN2B splicing mutation in intron 10 (c.2011-1G>A) was revealed in a WES study. The result was confirmed by Sanger sequencing. No mutation was found in both parents. Our finding confirms that early-onset EE may be caused not only by gain-of-function variants but also by splice site mutations-in particular those affecting the splice acceptor site of the 10th intron of the GRIN2B gene. © 2016 Wiley Periodicals, Inc.

Hexasomy 13q31.3q34 due to two marker chromosomes with inverted duplication in a fetus with increased nuchal translucency.

BACKGROUND: Small supernumerary marker chromosomes are structurally rearranged chromosomes that can be formed from different chromosomal fragments and cannot be identified using chromosomal banding analysis. Their examination has to be complemented by additional analyses like fluorescent in situ hybridization or array comparative genomic hybridization. METHODS: We report on partial hexasomy of chromosome 13q in a fetus of a pregnant woman referred to genetic counseling because of increased fetal nuchal translucency and increased risk of trisomy 21 and trisomy 18 in first-trimester combined prenatal screening. Using chromosome banding analysis, in situ hybridization and array comparative hybridization we revealed the presence of two marker chromosomes with inverted duplication resulting in hexasomy of a 22.6 Mbp fragment in chromosomal region 13q31.3-13q34 with the lack of chromosome 13 centromere. RESULTS: The fetus presented dysmorphic facial features, head and body disproportion, wide neck, ambiguous genitalia, incorrect position of the anus, and symmetrical shortening of the long bones were present in our described case. Some of these features were in accordance with other published cases. Other most often described features in tetrasomy were: microphtalmia or other major eye defects, ear abnormalities and deafness, hemangiomata, hypotelorism, severe learning disability and seizures. Despite a low risk of recurrence for small supernumerary marker chromosomes the possibility of germ line mosaicism exists, thus genetic counseling was offered to the examined family. CONCLUSION: A full characterization of small supernumerary marker chromosomes in fetal karyotype is necessary for pregnancy prognosis and genetic counseling.

The Role of Single Nucleotide Polymorphisms in MicroRNA Genes in Head and Neck Squamous Cell Carcinomas: Susceptibility and Prognosis.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent cancers worldwide. The identification of molecular alterations adding to the individual risk of HNSCC development and progression is one of the most important challenges in studies on cancer genetics. MicroRNAs (miRNAs), which belong to the group of important post-transcriptional regulators of human gene expression, seem to be valuable options for consideration as key modifiers of individual cancer risk, and therefore may be helpful in predicting inter-individual differences in cancer risk, response to treatment and prognosis. METHODS: There have not been many studies focused on the relationship between miRNA variants and HNSCC published in PubMed within the last 15 years. We found and analyzed 30 reviews, meta-analyses and research papers and revealed 14 SNPs which have been reported as significant in the context of HNSCC susceptibility and/or prognosis. RESULTS: These 14 SNPs were located in 13 separate miRNAs. Among them, four were the most frequently studied (miRNA-146, -196, -149 and -499) and have been shown to have the greatest impact on the course of HNSCC. However, the presented results have been conflicting. CONCLUSIONS: It must be concluded that, despite the years of studies, there are no conclusive reports demonstrating a significant role of SNPs in miRNAs in the context of the susceptibility to HNSCC or its prognosis.

Protein tyrosine phosphatase receptor-like genes are frequently hypermethylated in sporadic colorectal cancer.

The activity of phosphatases could be influenced by genetic, as well as epigenetic alterations. In our study, we have investigated the methylation status of four PTPRs: PTPRM, PTPRT, PTPRR and PTPRZ1, which were pre-selected using microarray techniques as being alternatively methylated in sporadic colorectal cancer (CRC). The analyses were carried out on 131 surgical specimens obtained from sporadic CRC patients. The methylation status of the four genes was examined using methyl specific PCR (MSP). The analysis of promoter methylation using an Illumina 27K microarray revealed four protein tyrosine phosphatases PTPRM, PTPRT, PTPRR and PTPRZ1 as being hypermethylated with ß-value ≥0.2 and P≤0.05. Subsequent analysis using MSP confirmed these observations-the frequency of promoter methylation was significantly higher in tumor cells compared with matched normal tissue for each of the analyzed genes. There was no association observed between the methylation status of PTPRs and either CIMP, K-ras (codon 12) and BRAF (exon 15, V600E) mutations or tumor localization (proximal/distal). The results of our study show a statistically significant difference between promoter methylation in cancerous and healthy tissue. This result supports the hypothesis that the PTPR family has an important role in the etiology of CRC.

Assessment of three epigenotypes in colorectal cancer by combined bisulfite restriction analysis.

Recent investigations have demonstrated the clear heterogeneity of sporadic colorectal cancer (CRC) with regard to CpG island methylation. Two unsupervised cluster analyses revealed that CRCs form three distinct DNA methylation subsets, which are referred to as the high-, intermediate-, and low-methylation epigenotypes (HME, IME, and LME, respectively). A recent study by Yagi et al. found a fairly sensitive and specific identification of HME, IME, and LME using two marker panels analyzed by MALDI-TOF mass spectrometry (MassARRAY). However, the expensive equipment required for this method substantially increases the cost and complexity of the assay. In this article, we demonstrate the assessment of HME, IME, and LME in a group of 233 sporadic CRCs using seven markers proposed by Yagi et al. The DNA methylation of each marker was quantified using combined bisulfite restriction analysis (COBRA) and analyzed along with various genetic factors associated with CRC [the BRAF and KRAS mutations, MLH1 methylation and microsatellite instability (MSI)]. The baseline methylation of each marker was generated from pooled DNA isolated from 50 normal colon tissues. We demonstrate that the correlation of HME, IME, and LME epigenotyped by COBRA using different molecular classifiers is similar to that achieved by MassARRAY. Therefore, epigenotyping CRCs using COBRA is a simple, specific, and cost-effective method that has the potential to be widely used in CRC research.

Assessment of chromosomal imbalances in CIMP-high and CIMP-low/CIMP-0 colorectal cancers.

Data presented in a number of recent studies have revealed a negative correlation between CpG island methylator phenotype (CIMP) and chromosomal instability (CIN) measured by a loss of heterozygosity (LOH) of selected loci, suggesting that CIN and CIMP represent two independent mechanisms in sporadic colorectal cancer (CRC) carcinogenesis. However, CIN is a heterogeneous phenomenon, which may be studied not only by employing LOH analysis but also by observing chromosomal imbalances (gains and deletions). The current study aimed to investigate the relationship between CIMP and chromosomal gains and deletions (assessed by comparative genomic hybridization) in a group of 20 CIMP-high and 79 CIMP-low/CIMP-0 CRCs. Our results revealed that the mean numbers of gains and of total chromosomal imbalances were significantly greater (p = 0.004 and p = 0.007, respectively) in the CIMP-low/CIMP-0 group compared to the CIMP-high group, while no significant difference was observed between the mean numbers of losses (p = 0.056). The analysis of copy number changes of 41 cancer-related genes by multiplex ligation-dependent probe amplification showed that CRK gene was exclusively deleted in CIMP-low/CIMP-0 tumors (p = 0.02). Given that chromosomal losses play an important role in tumor suppressor inactivation and chromosomal gains, in the activation of proto-oncogenes, we hypothesize that tumor suppressor inactivation plays similar roles in both CIMP-high and CIMP-low/CIMP-0 CRCs, while the predominance of chromosomal gains in CIMP-low/CIMP-0 tumors may suggest that the activation of proto-oncogenes is the underlying mechanism of CIMP-low/CIMP-0 CRC progression.

The Moderating Role of the FKBP5 Gene Polymorphisms in the Relationship between Attachment Style, Perceived Stress and Psychotic-like Experiences in Non-Clinical Young Adults.

Numerous studies have reported that stressful life experiences increase the risk of psychosis and psychotic-like experiences (PLEs). Common variations of the FKBP5 gene have been reported to impact the risk of psychosis by moderating the effects of environmental exposures. Moreover, anxious and avoidant attachment styles have been shown to increase both the level of perceived stress and the risk for psychosis development. In the present cross-sectional study, we aimed to investigate whether variants of the FKBP5 gene moderate the effects of attachment styles and the level of perceived stress on the development of PLEs. A total of 535 non-clinical undergraduates were genotyped for six FKBP5 single nucleotide polymorphisms (SNPs) (rs3800373, rs9470080, rs4713902, rs737054, rs1360780 and rs9296158). The Psychosis Attachment Measure (PAM), the Perceived Stress Scale-10 (PSS-10) and the Prodromal Questionnaire 16 (PQ-16) were administered to assess attachment styles, the level of perceived stress and PLEs, respectively. Anxious attachment style, lower levels of perceived self-efficacy and higher levels of perceived helplessness were associated with a significantly higher number of PLEs. The main effects of attachment style on the severity of PLEs were significant in models testing for the associations with perceived self-efficacy and three FKBP5 SNPs (rs1360780, rs9296158 and rs9470080). The main effect of rs38003733 on the number of PLEs was observed, with GG homozygotes reporting a significantly higher number of PLEs in comparison to T allele carriers. In individuals with dominant anxious attachment style, there was a significant effect of the interaction between the FKBP5 rs4713902 SNP and self-efficacy on the severity of PLEs. Among rs4713902 TT homozygotes, a low level of perceived self-efficacy was associated with higher severity of PLEs. In subjects with non-dominant anxious attachment, a low level of perceived self-efficacy was associated with a higher number of PLEs, regardless of the genotype. Our results indicate that the FKBP5 gene might moderate the relationship between attachment, perceived stress and PLEs.

Effects of traumatic life events, cognitive biases and variation in dopaminergic genes on psychosis proneness.

AIMS: Recent studies have provided evidence that interactions between variation in dopaminergic genes and stressful experiences might impact risk of psychosis. However, it remains unknown whether these interactions impact the development of subclinical symptoms, including psychotic-like experiences (PLEs). In this study, we aimed to test the effects of interactions between variation in dopaminergic genes and traumatic life events (TLEs) on a severity of PLEs. METHODS: We assessed TLEs, cognitive biases, PLEs as well as the catechol-O-methyltransferase (COMT) rs4680 and the dopamine D2 receptor (DRD2) rs6277 gene polymorphisms in 445 university students at three urban areas. RESULTS: There was a significant effect of the interaction between the COMT rs4680 and a history of any type of TLEs on a severity of PLEs. Among the COMT rs4680 Met allele carriers, a severity of PLEs was higher in individuals with a history of any type of TLEs. Further stratification of the sample revealed that this effect appears only in the group of participants with a high level of cognitive biases. The DRD2 rs6277 C allele was independently associated with a higher level of PLEs. CONCLUSIONS: Our results indicate that decreased dopamine catabolism related to the COMT gene polymorphism might increase psychosis proneness in individuals with a history of TLEs and high levels of cognitive biases. Variation in the DRD2 gene might exert independent effects on psychosis proneness. These findings imply that there are various levels of complexity in the models of interactions between genetic and environmental factors explaining the mechanisms underlying psychosis proneness.

The Impact of the FKBP5 Gene Polymorphisms on the Relationship between Traumatic Life Events and Psychotic-Like Experiences in Non-Clinical Adults.

Common variations of the FKBP5 gene are implicated in psychotic disorders, by modulating the hypothalamic-pituitary-adrenal axis reactivity to stress. It has been demonstrated that some of them might moderate the effects of childhood trauma on psychosis proneness. However, these associations have not been investigated with respect to traumatic life events (TLEs). Therefore, we aimed to explore whether the FKBP5 polymorphisms moderate the effects of TLEs on the level of psychotic-like experiences (PLEs). A total of 535 non-clinical adults were approached for participation, and genotyping of six FKBP5 polymorphisms (rs3800373, rs9470080, rs4713902, rs737054, rs1360780 and rs9296158) was performed. The Prodromal Questionnaire-16 (PQ-16) and the Traumatic Events Checklist (TEC) were administered to assess PLEs and TLEs, respectively. Among the rs1360780 CC homozygotes, a history of physical abuse was associated with significantly higher PQ-16 scores. This difference was not significant in the rs1360780 T allele carriers. Similarly, a history of physical abuse was associated with significantly higher PQ-16 scores in the rs9296158 GG homozygotes but not in the rs9296158 A allele carriers. Finally, emotional neglect was related to significantly higher PQ-16 scores in the rs737054 T allele carriers but not in the rs737054 CC homozygotes. The present study indicates that variation in the FKBP5 gene might moderate the effects of lifetime traumatic events on psychosis proneness.

Adverse Childhood Experiences and Methylation of the FKBP5 Gene in Patients with Psychotic Disorders.

Altered methylation of the FKBP5 gene has been observed in various mental disorders and attributed to the effects of adverse childhood experiences (ACEs). However, the level of FKBP5 methylation has not been investigated in patients with psychotic disorders. Therefore, in this study we aimed to determine the FKBP5 methylation in patients with psychosis and controls, taking into account the effects of ACEs. Participants were 85 patients with psychotic disorders, including first-episode psychosis (FEP) patients and acutely relapsed schizophrenia (SCZ-AR) patients, as well as 56 controls. The level of four CpG sites at the FKBP5 gene was determined in the peripheral blood leukocytes using pyrosequencing. After controlling for potential confounding factors, the level of FKBP5 methylation at one out of four tested CpG sites was significantly lower in FEP patients compared to other groups of participants. Significant main effects of parental antipathy and sexual abuse on the level of FKBP5 methylation were observed at the differentially methylated CpG site. Participants reporting this category of ACEs had significantly lower levels of FKBP5 methylation at this CpG site. Lower levels of FKBP5 methylation were associated with better cognitive performance and higher functional capacity in patients with psychosis. In controls, lower methylation of FKBP5 was related to worse performance of immediate memory and language skills. Our findings suggest that hypomethylation of the FKBP5 appears at early stages of psychosis and might be associated with a history of ACEs as well as less severe clinical manifestation.

Effects of interactions between variation in dopaminergic genes, traumatic life events, and anomalous self-experiences on psychosis proneness: Results from a cross-sectional study in a nonclinical sample.

BACKGROUND: There is a growing number of studies showing interactions between genetic polymorphisms associated with dopaminergic neurotransmission and traumatic life events (TLEs) on a risk of psychotic-like experiences (PLEs). Anomalous self-experiences (ASEs) have been associated both with TLEs as well as with PLEs. However, it remains unknown what is the role of ASEs in the complexity of gene-environment interactions on the emergence of PLEs. PATIENTS AND METHODS: We included 445 young adults-university students from three big cities in Poland. We used the Traumatic Events Checklist to assess TLEs, the Inventory of Psychotic-Like anomalous self-experiences in order to measure ASEs, and the Prodromal Questionnaire (PQ16) to record the level of PLEs. The following gene polymorphisms, related to dopaminergic neurotransmission, were determined: the catechol-O-methyltransferase (COMT) rs4680 polymorphism, the dopamine D2 receptor (DRD2) rs6277 polymorphism, and the dopamine transporter 1 (DAT1) rs28363170 polymorphism. RESULTS: There was a significant effect of the interaction between the DAT1 polymorphism, a severity of ASEs, and a history of TLEs on the level of PLEs. Among the DAT1 10R/10R homozygotes with low level of ASEs, a severity of PLEs was significantly higher in individuals with a history of any TLEs. Higher scores of the PQ16 were associated with a greater severity of ASEs both in the DAT1 9R allele carriers and the DAT1 10R/10R homozygotes. CONCLUSION: Our findings imply that genetic liability related to aberrant dopamine transport might impact the association between TLEs and PLEs in subjects with high levels of ASEs.

Rapid Whole-Exome Sequencing as a Diagnostic Tool in a Neonatal/Pediatric Intensive Care Unit.

Genetic disorders are the leading cause of infant morbidity and mortality. Due to the large number of genetic diseases, molecular and phenotype heterogeneity and often severe course, these diseases remain undiagnosed. In infants with a suspected acute monogenic disease, rapid whole-exome sequencing (R-WES) can be successfully performed. R-WES (singletons) was performed in 18 unrelated infants with a severe and/or progressing disease with the suspicion of genetic origin hospitalized in an Intensive Care Unit (ICU). Blood samples were also collected from the parents. The results from the R-WES were available after 5-14 days. A conclusive genetic diagnosis was obtained in 13 children, corresponding to an overall diagnostic yield of 72.2%. For nine patients, R-WES was used as a first-tier test. Eight patients were diagnosed with inborn errors of metabolism, mainly mitochondrial diseases. In two patients, the disease was possibly caused by variants in genes which so far have not been associated with human disease (NARS1 and DCAF5). R-WES proved to be an effective diagnostic tool for critically ill infants in ICUs suspected of having a genetic disorder. It also should be considered as a first-tier test after precise clinical description. The quickly obtained diagnosis impacts patient's medical management, and families can receive genetic counseling.

First-episode schizophrenia is associated with a reduction of HERV-K methylation in peripheral blood.

Human endogenous retroviruses (HERV) have been widely associated with schizophrenia etiology. Aberrant epigenetic processes may play a role in the etiology of schizophrenia. In this study, we tested whether schizophrenia patients at different stages of illness might present alterations in the levels of HERV-K methylation. We recruited 49 first-episode schizophrenia (FES) patients with 47 age- and sex-matched healthy controls (HCs), and 100 multi-episode schizophrenia (MES) patients with 50 age- and sex-matched HCs. Based on the Schedule for Deficit Schizophrenia, patients with MES were also divided into two subgroups: deficit (D-SCZ) and non-deficit schizophrenia (ND-SCZ). DNA methylation levels of HERV-K sequences were examined in peripheral blood leukocytes. We found significantly lower levels of HERV-K methylation in FES patients compared to HCs. Patients with MES and matched HCs had similar levels of HERV-K methylation. There was a significant positive correlation between chlorpromazine equivalent dosage and HERV-K methylation levels in MES patients, but not in FES individuals. No significant differences in HERV-K methylation levels between D-SCZ and ND-SCZ as well as HCs were found. Our results indicate lower HERV-K methylation levels at early stages of schizophrenia. This difference might normalize with subsequent exacerbations of schizophrenia, likely due to the effects of antipsychotics.

The Influence of Tumor Microenvironment on ATG4D Gene Expression in Colorectal Cancer Patients.

Despite great progress in research on the subject, the involvement of autophagy in colorectal cancer (CRC) pathogenesis (initiation, progression, metastasis) remains obscure and controversial. Autophagy is a catabolic process, fundamental to cell viability and connected with degradation/recycling of proteins and organelles. In this study, we aimed at investigating the relative expression level of mRNA via Real-Time PCR of 16 chosen genes belonging to Atg8 mammalian orthologs and their conjugation system, comprising GABARAP, GABARAPL1, GABARAPL2, MAP1LC3A, MAP1LC3B, MAP1LC3C, ATG3, ATG7, ATG10, ATG4A, ATG4B, ATG4C, ATG4D, and three genes encoding proteins building the multimeric ATG16L1 complex, namely ATG5, ATG12, and ATG16L1, in 73 colorectal tumors and paired adjacent normal colon mucosa. Our study demonstrated the relative downregulation of all examined genes in CRC tissues in comparison to adjacent noncancerous mucosa, with the highest rate of expression in both tumor and non-tumor tissues observed for GAPARBPL2 and the lowest for MAP1LC3C. Moreover, in patients with advanced-stage tumors and high values of regional lymph nodes, statistically significant downregulation of ATG4D expression in adjacent normal cells was observed. Our study confirms the role of autophagy genes as cancer suppressors in colorectal carcinogenesis. Furthermore, in regard to the ATG4D gene, we observed the influence of tumor microenvironments on gene expression in adjacent colon mucosa.

Polymorphisms in immune-inflammatory response genes and the risk of deficit schizophrenia.

Polymorphisms in immune-inflammatory response genes are believed to impact schizophrenia susceptibility. However, it remains unknown whether immunogenetic factors play a role in the etiology of deficit schizophrenia (D-SCZ). Therefore, we genotyped four polymorphisms in genes encoding two immune system regulatory proteins (CTLA-4 rs231775 and CD28 rs3116496), interleukin-6 (IL6 rs1800795) and transforming growth factor-ß (TGFB1 rs1800470) in 513 schizophrenia patients and 374 controls. The CD28 rs3116496-CC genotype and C-allele were significantly more frequent in the whole group of patients and D-SCZ patients compared to controls. Our results indicate that the CD28 rs3116496 polymorphism might impact the risk of schizophrenia, especially D-SCZ.

The BAX gene as a candidate for negative autophagy-related genes regulator on mRNA levels in colorectal cancer.

Autophagy is a catabolic process, which is involved in the maintenance of intracellular homeostasis by degrading redundant molecules and organelles. Autophagy begins with the formation of a double-membrane phagophore, followed by its enclosure, thus leading to the appearance of an autophagosome which fuses with lysosome. This process is highly conserved, precisely orchestrated and regulated by autophagy-related genes. Recently, autophagy has been widely studied in different types of cancers, including colorectal cancer. As it has been revealed, autophagy plays two opposite roles in tumorigenesis, as a tumor suppressor and a tumor enhancer/activator, and therefore is called a double-edge sword. Recently, interaction between autophagy and apoptosis has been found. Therefore, we aimed to study the mRNA levels of genes engaged in autophagy and apoptosis in colorectal cancer tissues. Colorectal cancer and adjacent healthy tissues were obtained from 73 patients diagnosed with primary colorectal cancer. Real-time PCR analysis employing Universal Probe Library was used to assess the expression of the seven following selected genes: BECN1, UVRAG, ULK1, ATG13, Bif-1, BCL2 and BAX. For all but one of the tested genes, a decrease in expression was observed. An increase in expression was observed for BAX. BAX expression decreases consistently from early to more advanced stages. High expression of BAX was strongly associated with negative UVRAG expression. The high expression of the BAX gene seems to be a negative regulator of autophagy in colorectal cancer cells. The relative downregulation of autophagy-related genes was observed in colorectal cancer samples.