Electroporation is a versatile method for in vitro or in vivo delivery of different molecules int... more Electroporation is a versatile method for in vitro or in vivo delivery of different molecules into cells. However, no study so far has analysed the effects of electric pulses used in electrochemotherapy (ECT pulses) or electric pulses used in electrogene therapy (EGT pulses) on malignant cells. We studied the effect of ECT and EGT pulses on human malignant melanoma cells in vitro in order to understand and predict the possible effect of electric pulses on gene expression and their possible effect on cell behaviour. We used microarrays with 2698 different oligonucleotides to obtain the expression profile of genes involved in apoptosis and cancer development in a malignant melanoma cell line (SK-MEL28) exposed to ECT pulses and EGT pulses. Cells exposed to ECT pulses showed a 68.8% average survival rate, while cells exposed to EGT pulses showed a 31.4% average survival rate. Only seven common genes were found differentially expressed in cells 16 h after exposure to ECT and EGT pulses....
Experimental biology and medicine (Maywood, N.J.), 2015
The heart is the first organ to function in the developing embryo. MicroRNAs (miRNAs) are small n... more The heart is the first organ to function in the developing embryo. MicroRNAs (miRNAs) are small non-coding RNAs involved in the translational regulation of gene expression, which is beside transcriptional regulation crucial for the morphologic development of muscle tissue. The aim of our study was to test the hypothesis that the expression of miR-1, miR-133a/b, and miR-208a correlates with gestational age as well as with an apoptotic and proliferative index in the developing human heart. Our study included normal heart tissue samples obtained at autopsy from 46 fetuses, 12 children, and 15 adults. Proliferation and apoptosis were measured by the immunohistochemical detection of Ki67 and cleaved-CK18. Expression of miR-1, miR-133a, miR-133b, and miR-208a was measured using real-time PCR. We found a similar level of expression of miR-133a/b in fetal and children hearts that was different from the levels in healthy adults. We also found a correlation between a miR-208a expression to th...
Cancer biomarkers : section A of Disease markers, 2012
The study focuses on BBC3 gene expression in primary head and neck squamous cell carcinomas (HNSC... more The study focuses on BBC3 gene expression in primary head and neck squamous cell carcinomas (HNSCC) in relation to pTNM classification. We used quantitative real-time PCR on 35 biopsy samples of HNSCC tumor samples to evaluate differences of BBC3 expression depending on tumor size, regional lymph node involvement, location and tumor staging. In order to confirm the model of BBC3-mediated apoptosis, we used immunohistochemistry to determine the expression of apoptotic proteins p53, p63, Bcl-2 and Bax. We also used publicly available cDNA microarray datasets. Our results show a general down-regulation of BBC3 in tumor tissue compared to adjacent normal tissue. The expression was significantly altered among different groups of patho-histologically evaluated tumor sizes, but not in relation to tumor location, regional lymph node involvement or tumor stage. That suggests the potential use of BBC3 as a new tumor size marker in HNSCC. Through protein expression analysis combined with publi...
Acta dermatovenerologica Alpina, Pannonica, et Adriatica, 2010
Keratoconus (KC) is a bilateral, non-inflammatory, and progredient corneal ectasia that mostly oc... more Keratoconus (KC) is a bilateral, non-inflammatory, and progredient corneal ectasia that mostly occurs as a sporadic disorder, but it has long been recognized that a significant minority of patients also exhibit a family history. In recent years several candidate genes such as VSX1 and SOD1 have been proposed, and some disease-causing mutations have been identified. Lately research has also focused on collagen genes, especially those that are differentially expressed in KC cornea. Alterations in COL4A3 and COL4A4 genes may be responsible for decreases in collagen types I and III, a feature often detected in KC. To investigate the role of all four genes in 113 Slovenian patients with sporadic or familial keratoconus, DNA extraction, polymerase chain reaction amplification, and sequencing of both genes were performed. No disease-causing mutations were found, but two previously identified single nucleotide polymorphisms were identified (A128A and 627+23G>A) in the VSX1 gene. D326Y in...
ATP2A2 encodes the sarco/endoplasmic reticulum Ca2+- ATPase (SERCA2) and has been identified as a... more ATP2A2 encodes the sarco/endoplasmic reticulum Ca2+- ATPase (SERCA2) and has been identified as a defective gene in Darier disease (DD). It is an autosomal dominant genodermatosis, which is characterized by loss of adhesion between suprabasal epidermal keratinocytes (acantholysis) and abnormal keratinization (dyskeratosis). We examined 28 Slovenian patients with DD (the cohort of patients represents over 50% of all DD patients in Slovenia) and screened genomic DNA for ATP2A2 mutations and RNA for splice site mutations. We identified 7 different ATP2A2 mutations, 4 of which are novel: A516P, R559G, 544+1del6, and 1762-6del18. We also found two previously described polymorphisms 2741+54 G>A in intron XVIII and 2172 G>A (A724A) in exon 15, with allele frequencies of 64.2% and 11.3%, respectively. The mutations are scattered throughout the gene and affect the actuator, phosphorylation, stalk and transmembrane domains of SERCA2. A P160L mutation in a Slovene patient with severe DD ...
Alterations in collagen type IV, alpha-3 (COL4A3) and collagen type IV, alpha-4 (COL4A4) genes ma... more Alterations in collagen type IV, alpha-3 (COL4A3) and collagen type IV, alpha-4 (COL4A4) genes may be responsible for a decrease in collagen types I and III, a feature often detected in keratoconus (KC). To evaluate the significance of alterations in COL4A3 and COL4A4 genes in KC patients, we screened both genes and estimated the significance of polymorphisms in Slovenian patients with KC. The study included 104 unrelated patients with KC and 157 healthy blood donors. Diagnosis was established by clinical examination, electronic refractometry, and keratometry. DNA was extracted from blood, and gene exons were amplified by PCR. Non-isotopic high-resolution single-stranded conformation analysis (SSCA) was used to screen COL4A3 and COL4A4 genes, and migration shifts detected by SSCA were subsequently sequenced. For statistical evaluation, control blood donors were chosen according to age, sex, and not having blood relationship. Neither patients nor control blood donors chosen for stati...
Acta dermatovenerologica Alpina, Pannonica, et Adriatica, 2008
MicroRNAs (miRNAs) are small (20-22 nt), non-coding RNAs involved in post-transcriptional gene si... more MicroRNAs (miRNAs) are small (20-22 nt), non-coding RNAs involved in post-transcriptional gene silencing. Their binding to the 3' UTR of target mRNAs influences the translation or stability of the transcripts. miRNAs have been shown to regulate several developmental and physiological processes, including stem cell differentiation and the immune response. Recent findings report their involvement in hair follicle morphogenesis (ablation of miRNAs from keratinocytes causes several defects, such as evagination instead of invagination), in psoriasis (skin-specific expression of miR-203 and psoriasisspecific expression of miR-146a, miR-21 and miR-125b in the skin), in autoimmune diseases affecting the skin, such as SLE and ITP, in wound healing (changes in the expression of specific miRNA at specific phases of the regeneration process), and in skin carcinogenesis (a novel miRNA signature that includes induction of miR-21, a candidate oncogenic miRNA). Researchers worldwide are interes...
The multidrug resistance 1 (MDRI) gene and transcription factor 4(TCF4) gene are suggested to be ... more The multidrug resistance 1 (MDRI) gene and transcription factor 4(TCF4) gene are suggested to be involved in the WNT signalling pathway, the most important pathway altered in colorectal cancer. Mutations in both genes have been identified and associated with colorectal tumors exhibiting high microsatellite instability (MSI-H). In this study, we report on the distribution of functional polymorphisms in the MDR] gene and somatic frameshift mutations in the TCF4 gene coding mononucleotide repetition in 62 MSI-H colorectal tumors. Somatic frameshift mutations in(of) the TCF4 gene were identified in 24/62 (39%) of the studied MSI-H tumors. The estimated allele frequencies of functional polymorphisms in(of) exon 21 (2677 G>T, Ala893Ser) and exon 26(3435 C>T, Ilel 142I1e) of the MDR] gene were 0.42 and 0.46 in the controls and 0.54 (p=0.035) and 0.60 (p=0.017) in the MSI-H tumors. However, the allele frequency of both functional MDR] polymorphisms did not significantly differ between...
It has been shown for hepatitis C virus (HCV) infection that host miRNAs contribute to the replic... more It has been shown for hepatitis C virus (HCV) infection that host miRNAs contribute to the replication of the viral RNA genome. However, the clinical impact of these and many other cellular miRNAs on HCV in humans is still largely unclear. We therefore analysed the expression of miR-122, miR-126, miR-181a and miR-136 in HCV-infected patients. The study included liver biopsies of 65 patients infected with HCV of different genotypes (gt 1, gt 1a, gt 1b, gt 3 and gt 4) and nine noninfected individuals. Expression analysis of miRNAs was performed by qPCR, and they were analysed for differences between patient gender and age, genotypes, stage of fibrosis, grade of inflammation, serum level of liver enzymes, serum viral load, the presence of steatosis and mode of transmission. Different target prediction algorithms were used to search for targets of analyzed miRNAs. Statistical analysis revealed significant up-regulation of miR-136 and down-regulation of miR-126 and miR-181a in patients infected with HCV of different genotypes compared with noninfected individuals. The same expression pattern was observed in different stages and grades of liver disease. miR-122 was up-regulated in women relative to men and associated to portal inflammation, miR-122 and miR-126 correlated with serum HCV load and miR-136 and miR-122 correlated with the presence of steatosis. miR-126 and miR-136 were differentially expressed between different modes of HCV transmission. There were approximately 2000 different targets predicted for all four miRNAs and each of the analyzed miRNAs could be involved in more than a 100 different biochemical pathways. miR-122, miR-126, miR-136 and miR-181a have been shown to be involved in HCV infection with different genotypes. Their expression has been associated with the gender, stage and grade of liver disease, mode of transmission, serum HCV load and the presence of steatosis. Numerous target genes and biochemical pathways are predicted for each of the analyzed miRNAs. All these results suggest their role in HCV-infected liver disease.
To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed... more To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed 227 sporadic renal epithelial tumors for mutations and hypermethylations in the von Hippel-Lindau tumor suppressor gene VHL. Tumors were classified according to the recommendations of the Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Somatic VHL mutations were
A 35-year-old white male with symptoms of paranoid schizophrenia was treated by psychiatrists for... more A 35-year-old white male with symptoms of paranoid schizophrenia was treated by psychiatrists for 13 years. During the final year, he developed severe dysphagia, reduced strength of the upper extremity muscles, and cognitive dysfunction. The patient died in his sleep. The only pathology found in coronal brain sections was ill-defined periventricular foci with prominent, firm vessels. Microscopy revealed abundant, hematoxylin and eosin-eosinophilic, periodic acid-Schiff-positive, thioflavin T-positive, and Congo red-negative deposits in the vessel walls, with hypoxic encephalopathy in the affected regions. Immunohistochemistry showed k light chains as the main component of the deposits. Ultrastructural analysis showed amorphous electron dense material in the vessel walls. Perivascular B-cell proliferation was present in the vicinity of affected areas. Polymerase chain reaction was applied for the assessment of B-cell clonality, revealing monoclonal rearrangement of the heavy chain Ig gene. Neither in the kidney nor in any other organ were deposits detected. This is the first case report of light chain deposition disease restricted to the brain. D
MicroRNAs (miRNAs), which are small and non-coding RNAs, are genome encoded from viruses to human... more MicroRNAs (miRNAs), which are small and non-coding RNAs, are genome encoded from viruses to humans. They contribute to various developmental, physiological and pathological processes in living organisms. A huge amount of research results revealed that miRNAs regulate these processes also in the heart. miRNAs may have cell-type-specific or tissue-specific expression patterns or may be expressed ubiquitously. Primary studies of miRNA involvement in hypertrophy, heart failure and myocardial infarction analyzed miRNAs that are enriched in or specific for cardiomyocytes; however, growing evidence suggest that other miRNAs, not cardiac or muscle-specific, play a significant role in cardiovascular disease. Abnormal miRNA regulation has been shown to be involved in cardiac diseases, suggesting that miRNAs might affect cardiac structure and function. In this review, we focus on miRNAs that have been found to contribute to the pathogenesis of myocardial infarction (MI) and the response post-MI and characterized as diagnostic, prognostic and therapeutic targets. The majority of these studies were performed using mouse and rat models of MI, with a focus on the identification of basic cellular and molecular pathways involved in MI and in the response post-MI. Much research has also been performed on animal and human plasma samples from MI individuals to identify miRNAs that are possible prognostic and/or diagnostic targets of MI and other MI-related diseases. A large proportion of research is focused on miRNAs as promising therapeutic targets and biomarkers of drug responses and/or stem cell treatment approaches. However, only a few studies have described miRNA expression in human heart tissue following MI.
MicroRNAs are small, noncoding RNAs that regulate gene expression by posttranscriptional regulati... more MicroRNAs are small, noncoding RNAs that regulate gene expression by posttranscriptional regulation of target genes. miR-200 family and miR-205 have been shown experimentally to regulate epithelial-mesenchymal transition. As epithelial-mesenchymal transition is the postulated pathogenetic mechanism in spindle cell carcinoma, we analyzed the expression of these microRNAs in spindle cell carcinoma of the head and neck in comparison to conventional squamous cell carcinoma of similar location and stage. We also analyzed the expression of classic and desmosomal cadherins, which are believed to be important targets during epithelial-mesenchymal transition. Forty-five cases of spindle cell carcinoma and 45 cases of squamous cell carcinoma of the head and neck were analyzed using real-time polymerase chain reaction for microRNAs, and immunohistochemistry for classic cadherins (E-and N-cadherins) and desmosomal cadherins. We found a significant down-regulation of the miR-200 family and miR-205, loss of desmosomal cadherins, and an altered expression of classic cadherins in spindle cell carcinoma in comparison to squamous cell carcinoma. Down-regulation of the miR-200 family and miR-205 strongly supports the postulated role of epithelial-mesenchymal transition in spindle cell carcinoma. These microRNAs act on transcription repressors that were also up-regulated in our cases of spindle cell carcinoma, both on mRNA and on protein levels. The result is not only an altered expression of classic cadherins in adherens junctions but also a complete loss of desmosomal cadherins.
The authors used polymerase chain reaction to analyse 56 Slovenian cystic fibrosis (CF) chromosom... more The authors used polymerase chain reaction to analyse 56 Slovenian cystic fibrosis (CF) chromosomes for the presence of delta F508 and eight other most frequent mutations located in exons 7,11 and 20 (R347P, R334W, G551D, R553X, S549RA, S549RT, S549I and S1255X) of the CF gene. We also determined the frequency of haplotypes associated with CF for six linked RFLP markers (MetD/TaqI, MetH/TaqI, XV-2c/TaqI, KM-19/PstI, MP6d9/MspI and J3.11/MspI) in 27 Slovenian CF families. delta F508 mutation was present in 55.4 percent of the CF chromosomes. No case of the other mutations were detected in the sample of tested CF chromosomes. A very high degree of association (0.88) has been found between DNA marker MetH and CF (as measured by the Yule's association coefficient) in our population. Using the RFLP markers XV-2c and KM-19, we found that 85% of delta F508 mutated chromosomes have a single 1 2 (B) haplotype, and that this haplotype is present on only 15.4 percent of CF chromosomes with...
Amyotrophic lateral sclerosis (ALS) is a complex fatal neurodegenerative disease characterized by... more Amyotrophic lateral sclerosis (ALS) is a complex fatal neurodegenerative disease characterized by progressive degeneration and loss of upper motor neurons in the cerebral cortex and lower motor neurons in brainstem and spinal cord. We established the frequencies of mutations in 4 major ALS-associated genes, SOD1, TARDBP, FUS, and C9ORF72 in a representative cohort of 85 Slovenian patients with sporadic form of ALS. Pathogenic massive hexanucleotide repeat expansion mutation in C9ORF72 was detected in 5.9% of patients and was the most common cause of the disease. In the remaining 3 genes, we identified 4 changes in 3 patients, p.Val14Met in SOD1, silent mutation p.Arg522Arg in FUS, and p.Gly93Cys in SOD1 together with a novel synonymous variant c.990A>G (p.Leu330Leu) in TARDBP gene, respectively. This study represents the first genetic screening of major causative genes for ALS in a cohort of sporadic ALS patients from Slovenia and is according to our knowledge the first such study in Slavic population. Overall, we genetically characterized 8.2% sporadic ALS patients.
Six cases of gynecomastia with pseudoangiomatous stromal hyperplasia (PASH) and multinucleated st... more Six cases of gynecomastia with pseudoangiomatous stromal hyperplasia (PASH) and multinucleated stromal giant cells (MSGC) associated with neurofibromatosis type 1 (NF1) have been reported, and finding MSGC within PASH in gynecomastia has been suggested as being a characteristic of NF1. The frequency of PASH with MSGC in gynecomastia and its specificity for NF1 have not, however, been systematically studied. A total of 337 gynecomastia specimens from 215 patients, aged from 8 to 78 years (median, 22 years) were reevaluated for the presence of PASH with MSGC. Breast tissue samples of 25 patients were analyzed for the presence of an NF1 gene mutation using next generation sequencing. Rare MSGC, usually in the background of PASH, were noted at least unilaterally in 27 (13 %) patients; and prominent MSGC, always in the background of PASH, were noted in 8 (4 %) patients. The NF1 gene was mutated in only 1 (an 8-year-old boy with known NF1 and prominent MSGC) of the 25 tested patients, including 6 patients with prominent MSGC and 19 patients with rare MSGC. MSGC, usually in the background of PASH, are not characteristic of NF1.
showed generalized irregular slow wave activity. The patient died due to respiratory insufficienc... more showed generalized irregular slow wave activity. The patient died due to respiratory insufficiency at the age of 60, 18 months after the onset of symptoms.
Electroporation is a versatile method for in vitro or in vivo delivery of different molecules int... more Electroporation is a versatile method for in vitro or in vivo delivery of different molecules into cells. However, no study so far has analysed the effects of electric pulses used in electrochemotherapy (ECT pulses) or electric pulses used in electrogene therapy (EGT pulses) on malignant cells. We studied the effect of ECT and EGT pulses on human malignant melanoma cells in vitro in order to understand and predict the possible effect of electric pulses on gene expression and their possible effect on cell behaviour. We used microarrays with 2698 different oligonucleotides to obtain the expression profile of genes involved in apoptosis and cancer development in a malignant melanoma cell line (SK-MEL28) exposed to ECT pulses and EGT pulses. Cells exposed to ECT pulses showed a 68.8% average survival rate, while cells exposed to EGT pulses showed a 31.4% average survival rate. Only seven common genes were found differentially expressed in cells 16 h after exposure to ECT and EGT pulses....
Experimental biology and medicine (Maywood, N.J.), 2015
The heart is the first organ to function in the developing embryo. MicroRNAs (miRNAs) are small n... more The heart is the first organ to function in the developing embryo. MicroRNAs (miRNAs) are small non-coding RNAs involved in the translational regulation of gene expression, which is beside transcriptional regulation crucial for the morphologic development of muscle tissue. The aim of our study was to test the hypothesis that the expression of miR-1, miR-133a/b, and miR-208a correlates with gestational age as well as with an apoptotic and proliferative index in the developing human heart. Our study included normal heart tissue samples obtained at autopsy from 46 fetuses, 12 children, and 15 adults. Proliferation and apoptosis were measured by the immunohistochemical detection of Ki67 and cleaved-CK18. Expression of miR-1, miR-133a, miR-133b, and miR-208a was measured using real-time PCR. We found a similar level of expression of miR-133a/b in fetal and children hearts that was different from the levels in healthy adults. We also found a correlation between a miR-208a expression to th...
Cancer biomarkers : section A of Disease markers, 2012
The study focuses on BBC3 gene expression in primary head and neck squamous cell carcinomas (HNSC... more The study focuses on BBC3 gene expression in primary head and neck squamous cell carcinomas (HNSCC) in relation to pTNM classification. We used quantitative real-time PCR on 35 biopsy samples of HNSCC tumor samples to evaluate differences of BBC3 expression depending on tumor size, regional lymph node involvement, location and tumor staging. In order to confirm the model of BBC3-mediated apoptosis, we used immunohistochemistry to determine the expression of apoptotic proteins p53, p63, Bcl-2 and Bax. We also used publicly available cDNA microarray datasets. Our results show a general down-regulation of BBC3 in tumor tissue compared to adjacent normal tissue. The expression was significantly altered among different groups of patho-histologically evaluated tumor sizes, but not in relation to tumor location, regional lymph node involvement or tumor stage. That suggests the potential use of BBC3 as a new tumor size marker in HNSCC. Through protein expression analysis combined with publi...
Acta dermatovenerologica Alpina, Pannonica, et Adriatica, 2010
Keratoconus (KC) is a bilateral, non-inflammatory, and progredient corneal ectasia that mostly oc... more Keratoconus (KC) is a bilateral, non-inflammatory, and progredient corneal ectasia that mostly occurs as a sporadic disorder, but it has long been recognized that a significant minority of patients also exhibit a family history. In recent years several candidate genes such as VSX1 and SOD1 have been proposed, and some disease-causing mutations have been identified. Lately research has also focused on collagen genes, especially those that are differentially expressed in KC cornea. Alterations in COL4A3 and COL4A4 genes may be responsible for decreases in collagen types I and III, a feature often detected in KC. To investigate the role of all four genes in 113 Slovenian patients with sporadic or familial keratoconus, DNA extraction, polymerase chain reaction amplification, and sequencing of both genes were performed. No disease-causing mutations were found, but two previously identified single nucleotide polymorphisms were identified (A128A and 627+23G>A) in the VSX1 gene. D326Y in...
ATP2A2 encodes the sarco/endoplasmic reticulum Ca2+- ATPase (SERCA2) and has been identified as a... more ATP2A2 encodes the sarco/endoplasmic reticulum Ca2+- ATPase (SERCA2) and has been identified as a defective gene in Darier disease (DD). It is an autosomal dominant genodermatosis, which is characterized by loss of adhesion between suprabasal epidermal keratinocytes (acantholysis) and abnormal keratinization (dyskeratosis). We examined 28 Slovenian patients with DD (the cohort of patients represents over 50% of all DD patients in Slovenia) and screened genomic DNA for ATP2A2 mutations and RNA for splice site mutations. We identified 7 different ATP2A2 mutations, 4 of which are novel: A516P, R559G, 544+1del6, and 1762-6del18. We also found two previously described polymorphisms 2741+54 G>A in intron XVIII and 2172 G>A (A724A) in exon 15, with allele frequencies of 64.2% and 11.3%, respectively. The mutations are scattered throughout the gene and affect the actuator, phosphorylation, stalk and transmembrane domains of SERCA2. A P160L mutation in a Slovene patient with severe DD ...
Alterations in collagen type IV, alpha-3 (COL4A3) and collagen type IV, alpha-4 (COL4A4) genes ma... more Alterations in collagen type IV, alpha-3 (COL4A3) and collagen type IV, alpha-4 (COL4A4) genes may be responsible for a decrease in collagen types I and III, a feature often detected in keratoconus (KC). To evaluate the significance of alterations in COL4A3 and COL4A4 genes in KC patients, we screened both genes and estimated the significance of polymorphisms in Slovenian patients with KC. The study included 104 unrelated patients with KC and 157 healthy blood donors. Diagnosis was established by clinical examination, electronic refractometry, and keratometry. DNA was extracted from blood, and gene exons were amplified by PCR. Non-isotopic high-resolution single-stranded conformation analysis (SSCA) was used to screen COL4A3 and COL4A4 genes, and migration shifts detected by SSCA were subsequently sequenced. For statistical evaluation, control blood donors were chosen according to age, sex, and not having blood relationship. Neither patients nor control blood donors chosen for stati...
Acta dermatovenerologica Alpina, Pannonica, et Adriatica, 2008
MicroRNAs (miRNAs) are small (20-22 nt), non-coding RNAs involved in post-transcriptional gene si... more MicroRNAs (miRNAs) are small (20-22 nt), non-coding RNAs involved in post-transcriptional gene silencing. Their binding to the 3' UTR of target mRNAs influences the translation or stability of the transcripts. miRNAs have been shown to regulate several developmental and physiological processes, including stem cell differentiation and the immune response. Recent findings report their involvement in hair follicle morphogenesis (ablation of miRNAs from keratinocytes causes several defects, such as evagination instead of invagination), in psoriasis (skin-specific expression of miR-203 and psoriasisspecific expression of miR-146a, miR-21 and miR-125b in the skin), in autoimmune diseases affecting the skin, such as SLE and ITP, in wound healing (changes in the expression of specific miRNA at specific phases of the regeneration process), and in skin carcinogenesis (a novel miRNA signature that includes induction of miR-21, a candidate oncogenic miRNA). Researchers worldwide are interes...
The multidrug resistance 1 (MDRI) gene and transcription factor 4(TCF4) gene are suggested to be ... more The multidrug resistance 1 (MDRI) gene and transcription factor 4(TCF4) gene are suggested to be involved in the WNT signalling pathway, the most important pathway altered in colorectal cancer. Mutations in both genes have been identified and associated with colorectal tumors exhibiting high microsatellite instability (MSI-H). In this study, we report on the distribution of functional polymorphisms in the MDR] gene and somatic frameshift mutations in the TCF4 gene coding mononucleotide repetition in 62 MSI-H colorectal tumors. Somatic frameshift mutations in(of) the TCF4 gene were identified in 24/62 (39%) of the studied MSI-H tumors. The estimated allele frequencies of functional polymorphisms in(of) exon 21 (2677 G>T, Ala893Ser) and exon 26(3435 C>T, Ilel 142I1e) of the MDR] gene were 0.42 and 0.46 in the controls and 0.54 (p=0.035) and 0.60 (p=0.017) in the MSI-H tumors. However, the allele frequency of both functional MDR] polymorphisms did not significantly differ between...
It has been shown for hepatitis C virus (HCV) infection that host miRNAs contribute to the replic... more It has been shown for hepatitis C virus (HCV) infection that host miRNAs contribute to the replication of the viral RNA genome. However, the clinical impact of these and many other cellular miRNAs on HCV in humans is still largely unclear. We therefore analysed the expression of miR-122, miR-126, miR-181a and miR-136 in HCV-infected patients. The study included liver biopsies of 65 patients infected with HCV of different genotypes (gt 1, gt 1a, gt 1b, gt 3 and gt 4) and nine noninfected individuals. Expression analysis of miRNAs was performed by qPCR, and they were analysed for differences between patient gender and age, genotypes, stage of fibrosis, grade of inflammation, serum level of liver enzymes, serum viral load, the presence of steatosis and mode of transmission. Different target prediction algorithms were used to search for targets of analyzed miRNAs. Statistical analysis revealed significant up-regulation of miR-136 and down-regulation of miR-126 and miR-181a in patients infected with HCV of different genotypes compared with noninfected individuals. The same expression pattern was observed in different stages and grades of liver disease. miR-122 was up-regulated in women relative to men and associated to portal inflammation, miR-122 and miR-126 correlated with serum HCV load and miR-136 and miR-122 correlated with the presence of steatosis. miR-126 and miR-136 were differentially expressed between different modes of HCV transmission. There were approximately 2000 different targets predicted for all four miRNAs and each of the analyzed miRNAs could be involved in more than a 100 different biochemical pathways. miR-122, miR-126, miR-136 and miR-181a have been shown to be involved in HCV infection with different genotypes. Their expression has been associated with the gender, stage and grade of liver disease, mode of transmission, serum HCV load and the presence of steatosis. Numerous target genes and biochemical pathways are predicted for each of the analyzed miRNAs. All these results suggest their role in HCV-infected liver disease.
To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed... more To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed 227 sporadic renal epithelial tumors for mutations and hypermethylations in the von Hippel-Lindau tumor suppressor gene VHL. Tumors were classified according to the recommendations of the Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Somatic VHL mutations were
A 35-year-old white male with symptoms of paranoid schizophrenia was treated by psychiatrists for... more A 35-year-old white male with symptoms of paranoid schizophrenia was treated by psychiatrists for 13 years. During the final year, he developed severe dysphagia, reduced strength of the upper extremity muscles, and cognitive dysfunction. The patient died in his sleep. The only pathology found in coronal brain sections was ill-defined periventricular foci with prominent, firm vessels. Microscopy revealed abundant, hematoxylin and eosin-eosinophilic, periodic acid-Schiff-positive, thioflavin T-positive, and Congo red-negative deposits in the vessel walls, with hypoxic encephalopathy in the affected regions. Immunohistochemistry showed k light chains as the main component of the deposits. Ultrastructural analysis showed amorphous electron dense material in the vessel walls. Perivascular B-cell proliferation was present in the vicinity of affected areas. Polymerase chain reaction was applied for the assessment of B-cell clonality, revealing monoclonal rearrangement of the heavy chain Ig gene. Neither in the kidney nor in any other organ were deposits detected. This is the first case report of light chain deposition disease restricted to the brain. D
MicroRNAs (miRNAs), which are small and non-coding RNAs, are genome encoded from viruses to human... more MicroRNAs (miRNAs), which are small and non-coding RNAs, are genome encoded from viruses to humans. They contribute to various developmental, physiological and pathological processes in living organisms. A huge amount of research results revealed that miRNAs regulate these processes also in the heart. miRNAs may have cell-type-specific or tissue-specific expression patterns or may be expressed ubiquitously. Primary studies of miRNA involvement in hypertrophy, heart failure and myocardial infarction analyzed miRNAs that are enriched in or specific for cardiomyocytes; however, growing evidence suggest that other miRNAs, not cardiac or muscle-specific, play a significant role in cardiovascular disease. Abnormal miRNA regulation has been shown to be involved in cardiac diseases, suggesting that miRNAs might affect cardiac structure and function. In this review, we focus on miRNAs that have been found to contribute to the pathogenesis of myocardial infarction (MI) and the response post-MI and characterized as diagnostic, prognostic and therapeutic targets. The majority of these studies were performed using mouse and rat models of MI, with a focus on the identification of basic cellular and molecular pathways involved in MI and in the response post-MI. Much research has also been performed on animal and human plasma samples from MI individuals to identify miRNAs that are possible prognostic and/or diagnostic targets of MI and other MI-related diseases. A large proportion of research is focused on miRNAs as promising therapeutic targets and biomarkers of drug responses and/or stem cell treatment approaches. However, only a few studies have described miRNA expression in human heart tissue following MI.
MicroRNAs are small, noncoding RNAs that regulate gene expression by posttranscriptional regulati... more MicroRNAs are small, noncoding RNAs that regulate gene expression by posttranscriptional regulation of target genes. miR-200 family and miR-205 have been shown experimentally to regulate epithelial-mesenchymal transition. As epithelial-mesenchymal transition is the postulated pathogenetic mechanism in spindle cell carcinoma, we analyzed the expression of these microRNAs in spindle cell carcinoma of the head and neck in comparison to conventional squamous cell carcinoma of similar location and stage. We also analyzed the expression of classic and desmosomal cadherins, which are believed to be important targets during epithelial-mesenchymal transition. Forty-five cases of spindle cell carcinoma and 45 cases of squamous cell carcinoma of the head and neck were analyzed using real-time polymerase chain reaction for microRNAs, and immunohistochemistry for classic cadherins (E-and N-cadherins) and desmosomal cadherins. We found a significant down-regulation of the miR-200 family and miR-205, loss of desmosomal cadherins, and an altered expression of classic cadherins in spindle cell carcinoma in comparison to squamous cell carcinoma. Down-regulation of the miR-200 family and miR-205 strongly supports the postulated role of epithelial-mesenchymal transition in spindle cell carcinoma. These microRNAs act on transcription repressors that were also up-regulated in our cases of spindle cell carcinoma, both on mRNA and on protein levels. The result is not only an altered expression of classic cadherins in adherens junctions but also a complete loss of desmosomal cadherins.
The authors used polymerase chain reaction to analyse 56 Slovenian cystic fibrosis (CF) chromosom... more The authors used polymerase chain reaction to analyse 56 Slovenian cystic fibrosis (CF) chromosomes for the presence of delta F508 and eight other most frequent mutations located in exons 7,11 and 20 (R347P, R334W, G551D, R553X, S549RA, S549RT, S549I and S1255X) of the CF gene. We also determined the frequency of haplotypes associated with CF for six linked RFLP markers (MetD/TaqI, MetH/TaqI, XV-2c/TaqI, KM-19/PstI, MP6d9/MspI and J3.11/MspI) in 27 Slovenian CF families. delta F508 mutation was present in 55.4 percent of the CF chromosomes. No case of the other mutations were detected in the sample of tested CF chromosomes. A very high degree of association (0.88) has been found between DNA marker MetH and CF (as measured by the Yule's association coefficient) in our population. Using the RFLP markers XV-2c and KM-19, we found that 85% of delta F508 mutated chromosomes have a single 1 2 (B) haplotype, and that this haplotype is present on only 15.4 percent of CF chromosomes with...
Amyotrophic lateral sclerosis (ALS) is a complex fatal neurodegenerative disease characterized by... more Amyotrophic lateral sclerosis (ALS) is a complex fatal neurodegenerative disease characterized by progressive degeneration and loss of upper motor neurons in the cerebral cortex and lower motor neurons in brainstem and spinal cord. We established the frequencies of mutations in 4 major ALS-associated genes, SOD1, TARDBP, FUS, and C9ORF72 in a representative cohort of 85 Slovenian patients with sporadic form of ALS. Pathogenic massive hexanucleotide repeat expansion mutation in C9ORF72 was detected in 5.9% of patients and was the most common cause of the disease. In the remaining 3 genes, we identified 4 changes in 3 patients, p.Val14Met in SOD1, silent mutation p.Arg522Arg in FUS, and p.Gly93Cys in SOD1 together with a novel synonymous variant c.990A>G (p.Leu330Leu) in TARDBP gene, respectively. This study represents the first genetic screening of major causative genes for ALS in a cohort of sporadic ALS patients from Slovenia and is according to our knowledge the first such study in Slavic population. Overall, we genetically characterized 8.2% sporadic ALS patients.
Six cases of gynecomastia with pseudoangiomatous stromal hyperplasia (PASH) and multinucleated st... more Six cases of gynecomastia with pseudoangiomatous stromal hyperplasia (PASH) and multinucleated stromal giant cells (MSGC) associated with neurofibromatosis type 1 (NF1) have been reported, and finding MSGC within PASH in gynecomastia has been suggested as being a characteristic of NF1. The frequency of PASH with MSGC in gynecomastia and its specificity for NF1 have not, however, been systematically studied. A total of 337 gynecomastia specimens from 215 patients, aged from 8 to 78 years (median, 22 years) were reevaluated for the presence of PASH with MSGC. Breast tissue samples of 25 patients were analyzed for the presence of an NF1 gene mutation using next generation sequencing. Rare MSGC, usually in the background of PASH, were noted at least unilaterally in 27 (13 %) patients; and prominent MSGC, always in the background of PASH, were noted in 8 (4 %) patients. The NF1 gene was mutated in only 1 (an 8-year-old boy with known NF1 and prominent MSGC) of the 25 tested patients, including 6 patients with prominent MSGC and 19 patients with rare MSGC. MSGC, usually in the background of PASH, are not characteristic of NF1.
showed generalized irregular slow wave activity. The patient died due to respiratory insufficienc... more showed generalized irregular slow wave activity. The patient died due to respiratory insufficiency at the age of 60, 18 months after the onset of symptoms.
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Papers by Damjan Glavac