G. Nasioulas - Academia.edu (original) (raw)

Papers by G. Nasioulas

Research paper thumbnail of Molecular analysis of Kaposi's sarcoma occurring during haemodialysis

Clinical and Experimental Dermatology, 2004

Human Herpesvirus 8 (HHV-8) has been implicated in the pathogenesis of Kaposi's sarcoma (... more Human Herpesvirus 8 (HHV-8) has been implicated in the pathogenesis of Kaposi's sarcoma (KS). In this paper we attempted to confirm the connection between dialysis, HHV-8, and KS by examining the case of an elderly haemodialysis nonimmunosuppressed male patient with end-stage renal disease, who developed KS. By using PCR we have verified the presence of DNA from two different genomic regions (ORF 26 and ORF K1) of HHV-8. In addition, our RT-PCR results suggest active replication of HHV-8 in blood and KS lesions of the patient. Phylogenetic analysis revealed identical DNA sequence to ORF K1, and a close relation to its C1 variant. In conclusion, we document the case of KS and HHV-8 coexistence in a Greek elderly patient undergoing regular haemodialysis. Furthermore, our results indicate that factors other than immunosuppression could lead to KS development possibly due to activation of HHV-8.

Research paper thumbnail of Dating the origin of the CCR5-Δ32 AIDS-resistance allele by the coalescence of …

The American Journal of …, 1998

The CCR5-Δ32 deletion obliterates the CCR5 chemokine and the human immunodeficiency virus (HIV)–1... more The CCR5-Δ32 deletion obliterates the CCR5 chemokine and the human immunodeficiency virus (HIV)–1 coreceptor on lymphoid cells, leading to strong resistance against HIV-1 infection and AIDS. A genotype survey of 4,166 individuals revealed a cline of CCR5-Δ32 allele ...

Research paper thumbnail of Allele frequency of the CCR5 mutant chemokine receptor in Greek Caucasians

Journal of acquired immune deficiency syndromes and human retrovirology : official publication of the International Retrovirology Association, 1998

Research paper thumbnail of Newly established tumourigenic primary human colon cancer cell lines are sensitive to TRAIL-induced apoptosis in vitro and in vivo

British journal of cancer, Jan 2, 2007

Most data on the therapeutic potential of tumour necrosis factor-related apoptosis-inducing ligan... more Most data on the therapeutic potential of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) as well as resistance to FAS ligand (FASL) in colorectal cancer have come from in vitro studies using cell lines. To gain a clearer understanding about the susceptibility of patient tumours to TRAIL and FASL, we derived primary human cancer epithelial cells from colon cancer patients. Characterisation of primary cultures PAP60 and MIH55 determined their highly proliferating advantage, transforming capability and tumorigenicity in vitro and in vivo. Although FASL treatment appeared to cause little apoptosis only in the PAP60 primary culture, increased apoptosis independent of p53 was observed in both primary PAP60 and MIH55 and control cell lines Caco-2, HT29 and DLD-1 after treatment with SuperKiller TRAIL. Expression analysis of death receptors (DR) in the original parental tumours, the primary cultures before and after engraftment as well as the mouse xenografts, revealed a s...

Research paper thumbnail of Molecular Analysis of GISTs: Evaluation of Sequencing and dHPLC

DNA and Cell Biology, 2004

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointes... more Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and are characterized by mutations in the proto-oncogene KIT (c-kit). To date, the detection of genomic alterations of the c-kit gene has been based mostly on direct sequencing. However, sequencing is an expensive and time-consuming approach. Since the technology of WAVE DNA Fragment Analysis System (Transgenomic, Inc., Worcester, MA) (dHPLC) is available in our laboratory, we decided to evaluate its use. Sixteen patients with small/large intestine, stomach tumors were included in the study. Immunohistochemical evaluation was performed on formalin-fixed, paraffin-embedded specimens with the polyclonal antibody CD117 for the KIT protein. After DNA extraction and isolation from paraffin-embedded sections, a nested PCR approach was applied to amplify sequences of exon 11 of the c-kit gene. dHPLC and the ABI Prism 310 Genetic Analyzer (Applied Biosystems, Bedford, MA) were used respectively for screening and identification of genomic alterations. Immunohistochemical analysis revealed strong and diffuse KIT expression in each of the 16 paraffin-embedded sections examined. dHPLC analysis in two temperatures showed the presence of genomic alterations in 8 out of 16 (50%) samples examined. Subsequently, sequence analysis of exon 11 in those samples revealed c-kit alterations in only 8 out of 16 (50%) samples. These were five deletions, one of which was an in-frame deletion one-point mutation and one insertion. Furthermore, the sensitivity of both methods was compared by using different mixtures of a wild-type and a sample with a deletion in exon 11. dHPLC was shown to be able to detect genomic alterations in all four different sample mixtures, whereas with sequence analysis genomic alterations were detected only in the 1:2 and 1:4 sample mixtures. In conclusion, we showed that dHPLC is an efficient and accurate, as well as a more sensitive, method for screening of genomic alterations in exon 11 of the c-kit gene, compared to sequence analysis.

Research paper thumbnail of Novel germline mutations in the APC gene of Cypriot patients with familial and sporadic adenomatous polyposis

Clinical Genetics, 2006

Familial adenomatous polyposis (FAP) is one of the two commonest familial syndromes that predispo... more Familial adenomatous polyposis (FAP) is one of the two commonest familial syndromes that predispose to colorectal cancer. FAP is caused by mutations in the adenomatous polyposis coli (APC) tumour suppressor gene that has a high penetrance. The disease is characterized by the occurrence of hundreds to thousands of colorectal polyps, which if left untreated give rise to colorectal cancer. In Cyprus, there are no molecular data available as yet on families with FAP. This work presents the results of APC analysis in our population for the first time.

Research paper thumbnail of Novel mutations of the APC gene in familial adenomatous polyposis in Greek patients

Cancer Genetics and Cytogenetics, 2003

Familial adenomatous polyposis (FAP), a premalignant clinical entity inherited as an autosomal do... more Familial adenomatous polyposis (FAP), a premalignant clinical entity inherited as an autosomal dominant trait, is characterized by the development thousands of adenomatous polyps of the colorectum during the 2nd and 3rd decade of life. Approximately 80% of patients with FAP harbor truncating germline mutations in the adenomatous polyposis coli (APC) tumor suppressor gene. We tested 24 members of six Greek families. All patients had the FAP phenotype, and one patient had an extracolonic tumor (medulloblastoma). Our method for testing was the polymerase chain reaction (PCR) amplification from genomic DNA extracted from whole blood, followed by automated DNA sequencing. Two novel truncating mutations (2601delGA and R923X) and three already-known mutations (R876X, Q1045X, and D1822V) were found. Other polymorphisms were also found. We identified the inactivating APC mutation in 12 of 13 of our FAP patients. Our results suggest that PCR sequencing is a reliable method for screening the APC gene for germline mutations.

Research paper thumbnail of Molecular Analysis of the Full-Length Genome of HIV Type 1 Subtype I: Evidence of A/G/I Recombination

AIDS Research and Human Retroviruses, 1999

Phylogenetic analysis of partial env sequences of HIV-1 isolates from Cyprus and Greece suggested... more Phylogenetic analysis of partial env sequences of HIV-1 isolates from Cyprus and Greece suggested the existence of a distinct subtype of the virus, designated as I. We examined whether this subtype represents a distinct group, or a mosaic consisting of previously characterized subtypes. The full-length sequences under consideration were recovered from serum samples of "subtype I" obtained from two nonepidemiologically linked HIV-1-infected subjects in Greece. The first subject was an intravenous drug user (IDU), while the second was a vertically infected child born in 1984 whose parents were both IDUs. A variety of methods, such as diversity plots as well as phylogenetic and informative site analyses, were used to classify the DNA sequences. Subsequent detailed analysis revealed a unique genomic organization composed of alternating portions of subtypes A, G, and I. The two Greek isolates formed a distinct group in most of the pol, gp120, and gp41 regions, and in the vif/vpr, vpu, LTR, and 5' terminus of nef. In contrast, different parts of env and gag as well as the 3' pol region, and the first exons of tat and rev, appeared to have arisen from subtypes A and G. Our results indicate that subtype I, which was probably circulating in Greece in the early 1980s, is a triple mosaic consisting of A, G, and I sequences.

Research paper thumbnail of Genotypic Characterization of Human Immunodeficiency Virus Type 1 in Greece

AIDS Research and Human Retroviruses, 1998

The HIV-1 subtype distribution in 83 HIV-1-seropositive individuals living in Greece was investig... more The HIV-1 subtype distribution in 83 HIV-1-seropositive individuals living in Greece was investigated by using the heteroduplex mobility assay (HMA), DNA sequencing, and phylogenetic analysis. The results revealed that partial HIV-1 gp120 sequences from 71 (86%) patients were subtype B, 5 (6%) were subtype A, 4 were subtype D (5%), 2 (2%) were subtype C, and 1 (1%) was subtype I. The subtype I isolate was documented in an intravenous drug user. A high prevalence (90-100%) of B isolates among intravenous drug users, hemophiliacs, and homosexual men was observed, in contrast to heterosexuals, among whom non-B subtypes seemed to be common (42.9%, p < 0.001). Among the Greek population subtype B is the most frequent (94%), in contrast to the high prevalence (57%) of non-B isolates found in emigrants living in Greece (p < 0.001). A heterosexual transmission case of subtype D in a Greek individual not traveling abroad was also documented. The broad HIV-1 diversity in Greece may be explained by population movements, such as migration and traveling.

Research paper thumbnail of Genetics of familial colorectal cancer: the experience in Cyprus

Familial adenomatous,polyposis (FAP) and Hereditary Non Polyposis Syndrome,(HNPCC) are the two co... more Familial adenomatous,polyposis (FAP) and Hereditary Non Polyposis Syndrome,(HNPCC) are the two commonest,familial syndromes,that predispose to colorectal cancer. FAP is caused,by mutations in the ,Adenomatous ,Polyposis Coli (APC) tumour suppressor ,gene ,that has a high penetrance. The disease ,is characterized by ,the occurrence ,of hundreds ,to thousands ,of

Research paper thumbnail of Molecular analysis of Kaposi's sarcoma occurring during haemodialysis

Clinical and Experimental Dermatology, 2004

Human Herpesvirus 8 (HHV-8) has been implicated in the pathogenesis of Kaposi's sarcoma (... more Human Herpesvirus 8 (HHV-8) has been implicated in the pathogenesis of Kaposi's sarcoma (KS). In this paper we attempted to confirm the connection between dialysis, HHV-8, and KS by examining the case of an elderly haemodialysis nonimmunosuppressed male patient with end-stage renal disease, who developed KS. By using PCR we have verified the presence of DNA from two different genomic regions (ORF 26 and ORF K1) of HHV-8. In addition, our RT-PCR results suggest active replication of HHV-8 in blood and KS lesions of the patient. Phylogenetic analysis revealed identical DNA sequence to ORF K1, and a close relation to its C1 variant. In conclusion, we document the case of KS and HHV-8 coexistence in a Greek elderly patient undergoing regular haemodialysis. Furthermore, our results indicate that factors other than immunosuppression could lead to KS development possibly due to activation of HHV-8.

Research paper thumbnail of Dating the origin of the CCR5-Δ32 AIDS-resistance allele by the coalescence of …

The American Journal of …, 1998

The CCR5-Δ32 deletion obliterates the CCR5 chemokine and the human immunodeficiency virus (HIV)–1... more The CCR5-Δ32 deletion obliterates the CCR5 chemokine and the human immunodeficiency virus (HIV)–1 coreceptor on lymphoid cells, leading to strong resistance against HIV-1 infection and AIDS. A genotype survey of 4,166 individuals revealed a cline of CCR5-Δ32 allele ...

Research paper thumbnail of Allele frequency of the CCR5 mutant chemokine receptor in Greek Caucasians

Journal of acquired immune deficiency syndromes and human retrovirology : official publication of the International Retrovirology Association, 1998

Research paper thumbnail of Newly established tumourigenic primary human colon cancer cell lines are sensitive to TRAIL-induced apoptosis in vitro and in vivo

British journal of cancer, Jan 2, 2007

Most data on the therapeutic potential of tumour necrosis factor-related apoptosis-inducing ligan... more Most data on the therapeutic potential of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) as well as resistance to FAS ligand (FASL) in colorectal cancer have come from in vitro studies using cell lines. To gain a clearer understanding about the susceptibility of patient tumours to TRAIL and FASL, we derived primary human cancer epithelial cells from colon cancer patients. Characterisation of primary cultures PAP60 and MIH55 determined their highly proliferating advantage, transforming capability and tumorigenicity in vitro and in vivo. Although FASL treatment appeared to cause little apoptosis only in the PAP60 primary culture, increased apoptosis independent of p53 was observed in both primary PAP60 and MIH55 and control cell lines Caco-2, HT29 and DLD-1 after treatment with SuperKiller TRAIL. Expression analysis of death receptors (DR) in the original parental tumours, the primary cultures before and after engraftment as well as the mouse xenografts, revealed a s...

Research paper thumbnail of Molecular Analysis of GISTs: Evaluation of Sequencing and dHPLC

DNA and Cell Biology, 2004

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointes... more Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and are characterized by mutations in the proto-oncogene KIT (c-kit). To date, the detection of genomic alterations of the c-kit gene has been based mostly on direct sequencing. However, sequencing is an expensive and time-consuming approach. Since the technology of WAVE DNA Fragment Analysis System (Transgenomic, Inc., Worcester, MA) (dHPLC) is available in our laboratory, we decided to evaluate its use. Sixteen patients with small/large intestine, stomach tumors were included in the study. Immunohistochemical evaluation was performed on formalin-fixed, paraffin-embedded specimens with the polyclonal antibody CD117 for the KIT protein. After DNA extraction and isolation from paraffin-embedded sections, a nested PCR approach was applied to amplify sequences of exon 11 of the c-kit gene. dHPLC and the ABI Prism 310 Genetic Analyzer (Applied Biosystems, Bedford, MA) were used respectively for screening and identification of genomic alterations. Immunohistochemical analysis revealed strong and diffuse KIT expression in each of the 16 paraffin-embedded sections examined. dHPLC analysis in two temperatures showed the presence of genomic alterations in 8 out of 16 (50%) samples examined. Subsequently, sequence analysis of exon 11 in those samples revealed c-kit alterations in only 8 out of 16 (50%) samples. These were five deletions, one of which was an in-frame deletion one-point mutation and one insertion. Furthermore, the sensitivity of both methods was compared by using different mixtures of a wild-type and a sample with a deletion in exon 11. dHPLC was shown to be able to detect genomic alterations in all four different sample mixtures, whereas with sequence analysis genomic alterations were detected only in the 1:2 and 1:4 sample mixtures. In conclusion, we showed that dHPLC is an efficient and accurate, as well as a more sensitive, method for screening of genomic alterations in exon 11 of the c-kit gene, compared to sequence analysis.

Research paper thumbnail of Novel germline mutations in the APC gene of Cypriot patients with familial and sporadic adenomatous polyposis

Clinical Genetics, 2006

Familial adenomatous polyposis (FAP) is one of the two commonest familial syndromes that predispo... more Familial adenomatous polyposis (FAP) is one of the two commonest familial syndromes that predispose to colorectal cancer. FAP is caused by mutations in the adenomatous polyposis coli (APC) tumour suppressor gene that has a high penetrance. The disease is characterized by the occurrence of hundreds to thousands of colorectal polyps, which if left untreated give rise to colorectal cancer. In Cyprus, there are no molecular data available as yet on families with FAP. This work presents the results of APC analysis in our population for the first time.

Research paper thumbnail of Novel mutations of the APC gene in familial adenomatous polyposis in Greek patients

Cancer Genetics and Cytogenetics, 2003

Familial adenomatous polyposis (FAP), a premalignant clinical entity inherited as an autosomal do... more Familial adenomatous polyposis (FAP), a premalignant clinical entity inherited as an autosomal dominant trait, is characterized by the development thousands of adenomatous polyps of the colorectum during the 2nd and 3rd decade of life. Approximately 80% of patients with FAP harbor truncating germline mutations in the adenomatous polyposis coli (APC) tumor suppressor gene. We tested 24 members of six Greek families. All patients had the FAP phenotype, and one patient had an extracolonic tumor (medulloblastoma). Our method for testing was the polymerase chain reaction (PCR) amplification from genomic DNA extracted from whole blood, followed by automated DNA sequencing. Two novel truncating mutations (2601delGA and R923X) and three already-known mutations (R876X, Q1045X, and D1822V) were found. Other polymorphisms were also found. We identified the inactivating APC mutation in 12 of 13 of our FAP patients. Our results suggest that PCR sequencing is a reliable method for screening the APC gene for germline mutations.

Research paper thumbnail of Molecular Analysis of the Full-Length Genome of HIV Type 1 Subtype I: Evidence of A/G/I Recombination

AIDS Research and Human Retroviruses, 1999

Phylogenetic analysis of partial env sequences of HIV-1 isolates from Cyprus and Greece suggested... more Phylogenetic analysis of partial env sequences of HIV-1 isolates from Cyprus and Greece suggested the existence of a distinct subtype of the virus, designated as I. We examined whether this subtype represents a distinct group, or a mosaic consisting of previously characterized subtypes. The full-length sequences under consideration were recovered from serum samples of "subtype I" obtained from two nonepidemiologically linked HIV-1-infected subjects in Greece. The first subject was an intravenous drug user (IDU), while the second was a vertically infected child born in 1984 whose parents were both IDUs. A variety of methods, such as diversity plots as well as phylogenetic and informative site analyses, were used to classify the DNA sequences. Subsequent detailed analysis revealed a unique genomic organization composed of alternating portions of subtypes A, G, and I. The two Greek isolates formed a distinct group in most of the pol, gp120, and gp41 regions, and in the vif/vpr, vpu, LTR, and 5' terminus of nef. In contrast, different parts of env and gag as well as the 3' pol region, and the first exons of tat and rev, appeared to have arisen from subtypes A and G. Our results indicate that subtype I, which was probably circulating in Greece in the early 1980s, is a triple mosaic consisting of A, G, and I sequences.

Research paper thumbnail of Genotypic Characterization of Human Immunodeficiency Virus Type 1 in Greece

AIDS Research and Human Retroviruses, 1998

The HIV-1 subtype distribution in 83 HIV-1-seropositive individuals living in Greece was investig... more The HIV-1 subtype distribution in 83 HIV-1-seropositive individuals living in Greece was investigated by using the heteroduplex mobility assay (HMA), DNA sequencing, and phylogenetic analysis. The results revealed that partial HIV-1 gp120 sequences from 71 (86%) patients were subtype B, 5 (6%) were subtype A, 4 were subtype D (5%), 2 (2%) were subtype C, and 1 (1%) was subtype I. The subtype I isolate was documented in an intravenous drug user. A high prevalence (90-100%) of B isolates among intravenous drug users, hemophiliacs, and homosexual men was observed, in contrast to heterosexuals, among whom non-B subtypes seemed to be common (42.9%, p < 0.001). Among the Greek population subtype B is the most frequent (94%), in contrast to the high prevalence (57%) of non-B isolates found in emigrants living in Greece (p < 0.001). A heterosexual transmission case of subtype D in a Greek individual not traveling abroad was also documented. The broad HIV-1 diversity in Greece may be explained by population movements, such as migration and traveling.

Research paper thumbnail of Genetics of familial colorectal cancer: the experience in Cyprus

Familial adenomatous,polyposis (FAP) and Hereditary Non Polyposis Syndrome,(HNPCC) are the two co... more Familial adenomatous,polyposis (FAP) and Hereditary Non Polyposis Syndrome,(HNPCC) are the two commonest,familial syndromes,that predispose to colorectal cancer. FAP is caused,by mutations in the ,Adenomatous ,Polyposis Coli (APC) tumour suppressor ,gene ,that has a high penetrance. The disease ,is characterized by ,the occurrence ,of hundreds ,to thousands ,of