13 research outputs found

    <i>PIK3CA</i> is upregulated in non-proliferating tumor cells <i>in vivo.</i>

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    <p>A to C. Double immunostaining of p110α (green, FITC) and Ki67 (red, Texas Red) in human ovarian cancer B. High magnification of a region from A with low expression of p110α. p110α is expressed at low levels and localizes to the cytoplasm of Ki67-positive tumor cells. C. High magnification of a region from A with high expression of p110α. p110α is expressed at high levels and localizes to the plasma membrane in Ki67-negative tumor cells. D and E. Immunohistochemical localization of Ki67 allows for clear identification of areas of proliferating and areas of non-proliferating tumor cells <i>in vivo</i> in 2008 ovarian xenograft tumors. E. High magnification of area from D showing the boundary between a proliferating and a non-proliferating region. F to H. Strong expression and cell membrane localization of p110α is only found in Ki67-negative areas. F. Section adjacent to D, stained with antibody against human p110α (1:250 dilution). G. High magnification of area from F showing the boundary between proliferating and non-proliferating region. H. High magnification of area from G showing membrane localization of p110α in the non-proliferating region. I. Immunostaining of human cytokeratin identifies tumor cells in proliferating and non-proliferating areas in the 2008 xenograft model. The line traces the boundary between the two areas, as defined by Ki67 staining in adjacent section (see J). Both proliferating and non-proliferating regions are positive for human cytokeratin (FITC, green), indicating tumor cells. Cell nuclei were counterstained with DAPI. J to L. Double p110α and Ki67 immunostaining maps <i>PIK3CA</i> activation in proliferating or non-proliferating areas in 2008 xenograft tumors. J. Ki67 (red, Texas Red) and p110α (FITC, green) exhibit reciprocal expression. K and L. High magnification of proliferating region (I) and non-proliferating region (H) from J.</p

    NF-κB binds to the <i>PIK3CA</i> promoter and activates its expression.

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    <p>A. Illustration of the predicted NF-κB binding site in human (top) or murine (bottom) <i>PIK3CA</i> promoter region. B. Illustration of the constructs comprising luciferase linked to the human <i>PIK3CA</i> promoter with (Luc-2340/316) or without the NF-κB binding site (Luc-378/316). C. Summary of luciferase activities of Luc-2340/316 and Luc-378/316 co-transfected with pCMV- IκBα or pCMV- IκBαM. D. Gelshift assay using ovarian cancer cell nuclear extract after TNF-α stimulation. <u>Lane 1</u>, NF-κB binding site of wild-type human <i>PIK3CA</i> promoter (wt hu<i>PIK3CA</i> NF-κB probe) alone; <u>lanes 2 and 3</u>, wt hu<i>PIK3CA</i> NF-κB probe+nuclear extract; <u>lane 4</u>, control NF-κB probe+nuclear extract, <u>lanes 5 and 6</u>, mutated hu<i>PIK3CA</i> NF-κB probe+nuclear extract; <u>lane 7</u>, mutated control NF-κB probe+nuclear extract; <u>lanes 8 and 9</u>, scramble hu<i>PIK3CA</i> NF-κB probe+nuclear extract. E. Gel shift assay using recombinant NF-κB/p50 protein. <u>Lane 1</u>, wt hu<i>PIK3CA</i> NF-κB probe alone; <u>lanes 2 and 3</u>, wt hu<i>PIK3CA</i> NF-κB probe+p50; <u>lane 4</u>, mutated hu<i>PIK3CA</i> NF-κB probe alone; <u>lanes 5 and 6</u>, mutated hu<i>PIK3CA</i> NF-κB probe+p50; <u>lane 7</u>, control NF-κB probe alone; <u>lanes 8 and 9</u>, control NF-κB probe+p50.</p

    Identification and characterization of the human <i>PIK3CA</i> promoters.

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    <p>A. Illustration of the structure of human <i>PIK3CA</i> gene and its 5′ upstream regulatory region. B. A region highly rich in GC is found in the <i>PIK3CA</i> 5′TRR. C. Illustration of the primers used for mapping RT-PCR of the <i>PIK3CA</i> transcriptional start site (SST). D. Results of mapping RT-PCR. There is no band between the forward primer F1 located upstream of the SST and the reverse primer R located on exon 1 of <i>PIK3CA</i>. The right size bands could be detected between primer F2 or F3 (both located downstream of SST) and reverse primer R. E. A small splicing variant is found in the 5′UTR of human <i>PIK3CA</i> gene, which can also be detected by mapping RT-PCR (primers F2 and R). F. Summarized results of the transcriptional activity of <i>PIK3CA</i> TRR fragments.</p

    p110α is overexpressed in non-proliferating tumor cells <i>in vivo.</i>

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    <p>A. Immunohistochemical staining of p110α using high primary antibody concentration (1:50) reveals low expression of p110α diffusely in the cytoplasm of tumor cells in Ki67-positive (Ki67+) regions. B and C. High magnification of non-proliferating (B) and proliferating (C) regions from A.</p

    SNP profiling discriminates histology-related subgroups based on chromosomal instability status.

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    <p>Chromosomal instability status (CIN) according to the number of allele-specific copy number alterations (CNAs) and copy number neutral loss of heterozygosity (CNN LOH), using a human mapping 250K single nucleotide polymorphism (SNP) array with paired tumor DNA and normal DNA. CNAs were divided into three subgroups: CIN-high (≥9 arms with CNAs), CIN-low (1–8 arms with CNAs), and CIN-negative (0 CNAs). (A) Details of number of chromosomal arms with CNAs in each tumor of three histological subtypes (serous carcinomas, SC; clear cell carcinomas, CCC; endometrioid carcinomas, EC). Stage I/II and stage III/IV are colored differently. (B) Correlation between CIN status and histological subtypes. (C) Overview of CNAs by running SNP arrays with 57 ovarian cancer samples. Hierarchical clustering based on the Euclidean distance for dissimilarities is shown. The type A cluster includes tumors with a broad range and low frequency of CNAs, whereas the type B cluster includes tumors with a focal range and high frequency of CNAs. C, E, and S indicate clear cell carcinoma, endometrioid carcinoma, and serous carcinoma, respectively.</p
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