The oncogene Ahi-1 was recently identified through provirus insertional mutagenesis in murine leukemias and lymphomas. Its involvement in human leukemogenesis is demonstrated by gross perturbations in its expression in several leukemic cells lines, particularly in cutaneous T-cell lymphoma (CTCL) cell lines (Hut 78 and Hut 102). Hut 78 is derived from a patient with Sezary syndrome, a common leukemic variant of the human CTCL mycosis fungoides. Aberrant expression of AHI-1 mRNA and protein has been found in CD4⁺CD7⁻ leukemic Sezary cells from patients with Sezary syndrome. Moreover, stable suppression of AHI-1 using retroviral-mediated RNA interference in Hut 78 cells inhibits their transforming activity in vitro and in vivo. In an effort to identify genes involved in AHI-1-mediated leukemic transformation in CTCL, microarray analysis was performed to compare six RNA samples from AHI-1 suppressed Hut 78/sh4 cells to five samples from Hut 78 control cells. Limma and dChip analyses identified 218 and 95 differentially expressed genes, respectively, using a fold change criteria of > or < 2 and a p-value threshold of ≤ 0.01. After evaluation of both analyses, 21 genes were selected based upon interesting structural and functional information, specificity to hematopoietic cells or T-cells, and previous connections to cancer. Expression patterns of these 21 genes were validated by qRT-PCR with p-values < 0.05 ranging from 1.97 x 10⁻¹⁰ to 6.55 x 10⁻³, with the exception of BRDG1 at 5.88 x 10⁻². The observed up-regulation of both BIN1 and HCK in AHI-1 suppressed Hut 78/sh4 cells as compared to control cells further confirmed at the protein level. The tumor suppressor BIN1 is known to physically interact with c-MYC, which also exhibits differential protein expression in these cells. Characterization of BIN1 identified 4 isoforms all of which contain exon 10 and demonstrate alternative splicing of exons 12A and 13. Additionally, qRT-PCR results from primary Sezary samples indicate there is clinical significance in the expression changes detected for BIN1, HCK, REPS2, BRDG1, NKG7 and SPIB. These findings identify several new differentially expressed genes that may play critical roles in AHI-1-mediated leukemic transformation of human CTCL cells. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

Although it is fairly well accepted that Helicobacter pylori infection plays a significant role in causing gastric cancer, the exact mechanisms involved in its pathogenesis are unclear. We have examined the relationship between H. pylori infection and oncogene expression in different stages of disease progression from precursor lesions to gastric carcinoma. We used Diff-Quik stain to diagnose H. pylori infection and immunohistochemical stains against c-erbB-2, p53, ras, c-myc, and bcl-2 to determine expression of oncogenes. H. pylori infection was found in all cases of chronic gastritis, atrophic gastritis, intestinal metaplasia, and early gastric carcinoma, and in 16 of 30 (53%) cases of advanced gastric carcinoma. Overexpression of c-erbB-2 was found in 2 (7%) cases of advanced gastric carcinoma, which were H. pylori negative. Suppressor gene, p53, was overexpressed in 3 (30%) cases of intestinal metaplasia, 2 (33%) cases of early gastric carcinoma, and 18 (60%) cases of advanced gastric carcinoma. Of these 18 p53-positive advanced gastric cancer cases, 11 (61%) were H. pylori positive. Expression of ras p21 was found in 4 (40%) cases of H. pylori-negative normal mucosa, 10 (100%) cases of chronic gastritis, 1 (10%) case of atrophic mucosa, 6 (60%) cases of intestinal metaplasia, 2 (33%) cases of nonneoplastic mucosa adjacent to early gastric carcinoma, and 7 (23%) nonneoplastic mucosa adjacent to advanced gastric carcinoma, all of which showed H. pylori. No evidence of expression of either c-myc or bcl-2 was detected in any of the above-mentioned samples. The data suggest that H. pylori infection may increase expression of ras p21 proteins and induce p53 suppressor gene mutation early in the process of gastric carcinogenesis.

No description available.

No description available.

A proteína jun é um dos principais integrantes do complexo AP-1 e está envolvido nos processos inflamatórios, diferenciação, apoptose e migração celular. Esta proteína pode formar homodímeros e heterodímeros por meio da dimerização que ocorre pelo sítio de sequências de leucinas. Existem evidências de que a proteína jun pode ser inibida pela proteína RPL10 mediante a ligação destas proteínas, no mesmo sítio de sequências de leucinas no núcleo celular, parando a progressão de tumores. O objetivo deste trabalho foi expressar, isolar e caracterizar a região de ligação das sequências de leucinas (região AP-1), para estudos posteriores de ligação com a proteína RPL10. O cDNA para proteína jun foi amplificado por PCR e clonado nos vetores de expressão pET 26b(+), pET 28a-c(+) e p1813 e expressa em E.coli BL21 (DE3). A proteína expressa em vetor pET28_AP1 foi eficientemente purificada pela técnica de cromatografia de afinidade a íons metálicos, por possuir uma sequência (poli)histidina que facilitou a purificação, apresentando um excelente grau de pureza. A identidade da proteína foi confirmada através de análise feita por western blotting e dot blotting e também por analise por espectrometria de massas. / The jun protein is one of the main AP-1 complex members and is involved in the inflammatory process, differentiation, apoptosis and cell migration. The Jun protein may form homodimers and heterodimers by dimerization in the leucines sequences site. There are evidences that jun protein can be inhibited by RPL10 protein through these protein binding in the same leucine sequences site, in the cell nucleus, stopping the tumor progress. The objective of this study was to express, isolate and characterize the binding region of the leucine sequences (AP-1 region) for subsequent binding studies with RPL10 protein. The jun protein cDNA was amplified by PCR and cloned into pET 26b(+), pET 28a-c(+) and p1813 expression vectors, and was expressed in E.coli BL21 (DE3). The protein expressed in pET28_AP1 vector was efficiently purified by the affinity chromatography technique to metal ions because have a (poly)histidine sequence which facilitate the protein purification, showing an excellent high purity. The protein identity was confirmed by western blotting and dot blotting and also by mass spectrometry analysis.

A proteína jun é um dos principais integrantes do complexo AP-1 e está envolvido nos processos inflamatórios, diferenciação, apoptose e migração celular. Esta proteína pode formar homodímeros e heterodímeros por meio da dimerização que ocorre pelo sítio de sequências de leucinas. Existem evidências de que a proteína jun pode ser inibida pela proteína RPL10 mediante a ligação destas proteínas, no mesmo sítio de sequências de leucinas no núcleo celular, parando a progressão de tumores. O objetivo deste trabalho foi expressar, isolar e caracterizar a região de ligação das sequências de leucinas (região AP-1), para estudos posteriores de ligação com a proteína RPL10. O cDNA para proteína jun foi amplificado por PCR e clonado nos vetores de expressão pET 26b(+), pET 28a-c(+) e p1813 e expressa em E.coli BL21 (DE3). A proteína expressa em vetor pET28_AP1 foi eficientemente purificada pela técnica de cromatografia de afinidade a íons metálicos, por possuir uma sequência (poli)histidina que facilitou a purificação, apresentando um excelente grau de pureza. A identidade da proteína foi confirmada através de análise feita por western blotting e dot blotting e também por analise por espectrometria de massas. / The jun protein is one of the main AP-1 complex members and is involved in the inflammatory process, differentiation, apoptosis and cell migration. The Jun protein may form homodimers and heterodimers by dimerization in the leucines sequences site. There are evidences that jun protein can be inhibited by RPL10 protein through these protein binding in the same leucine sequences site, in the cell nucleus, stopping the tumor progress. The objective of this study was to express, isolate and characterize the binding region of the leucine sequences (AP-1 region) for subsequent binding studies with RPL10 protein. The jun protein cDNA was amplified by PCR and cloned into pET 26b(+), pET 28a-c(+) and p1813 expression vectors, and was expressed in E.coli BL21 (DE3). The protein expressed in pET28_AP1 vector was efficiently purified by the affinity chromatography technique to metal ions because have a (poly)histidine sequence which facilitate the protein purification, showing an excellent high purity. The protein identity was confirmed by western blotting and dot blotting and also by mass spectrometry analysis.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [74]-91).

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 111-140).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 92-109).