Transcriptional deviation of the rat insulin-like growth factor II gene initiated at three alternative leader-exons between neonatal tissues and ascites hepatomas

Ueno, Takaki; Takahashi, K.; Matsuguchi, Tetsuya; Endo, Hideki; Yamamoto, Mikio

doi:10.1016/0167-4781(88)90138-8

Cited by 36 publications

(13 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transcription initiation at three different promoters generates alternate 5' noncoding exons, E1-E3, which are spliced to the shared coding exons, E4-E6. These promoters show tissue-and development-specific activity (Frunzio et al, 1986;Soares et al, 1986;Ueno et al, 1988).…”

Section: Introductionmentioning

confidence: 96%

Characterization of the Linked Ovine Insulin and Insulin-Like Growth Factor-II Genes

Ohlsen¹,

Lugenbeel²,

Wong³

1994

DNA and Cell Biology

View full text Add to dashboard Cite

The ovine insulin-like growth factor-II (oIGF-II) gene is comprised of 9 exons that span approximately 25 kb. Approximately 750 nucleotides upstream of oIGF-II exon 1 are the three exons of the ovine insulin gene that are transcribed in the same direction as oIGF-II. The genomic organization and expression of the oIGF-II gene is similar to that of the human IGF-II gene. Four putative promoters direct the transcription of six 5' noncoding exons (1, 3, 4, 5, 6, and 7), which are alternatively spliced to the shared exons 8, 9, and 10. An ovine exon comparable to human exon 2 has not been identified. Multiple transcription initiation sites were identified for exons 1 and 6 by primer extension analysis. Using a reverse transcriptase polymerase chain reaction (RT-PCR) assay, exon 1 and 3 transcripts were shown to be expressed in adult but not fetal liver. In addition, a novel transcript, which contained exon 1 spliced directly to exon 8, was detected in adult liver. Exon 4 transcripts were not detected in either fetal or adult liver, whereas exon 6 and 7 transcripts were detected in both fetal and adult liver. Exon 5 transcripts were also expressed in both fetal and adult liver, which is in contrast to the tumor cell-specific expression of human exon 5. Like the human and rodent genes, the regulation of expression of the oIGF-II gene is under complex control.

show abstract

Section: Introductionmentioning

confidence: 96%

Characterization of the Linked Ovine Insulin and Insulin-Like Growth Factor-II Genes

Ohlsen¹,

Lugenbeel²,

Wong³

1994

DNA and Cell Biology

View full text Add to dashboard Cite

show abstract

“…The structural organization of the human and rodent IGF-II genes has been extensively described (Ueno et al 1988;Holthuizen et al 1990). In man and rat, as well as in other species, the IGF-II gene is transcribed to produce multiple mature mRNAs of different sizes (reviewed in Sussenbach, 1989).…”

Section: Introductionmentioning

confidence: 99%

Developmental regulation of bovine insulin-like growth factor-II (IGF-II) gene expression: homology between bovine transcripts and human IGF-II exons

Boulle

Schneid²,

Listrat³

et al. 1993

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

Initial observations have indicated similarities between bovine and human IGF-II production during development. The aim of the present study was to investigate whether cattle could provide an experimental model that would mimic the complex pattern of human IGF-II gene expression. Expression of bovine IGF-II gene during development was studied by RNA hybridization using various human IGF-II probes. In fetal tissues and in adult muscle, the bovine IGF-II gene was expressed as a family of eight transcripts ranging in size from 5.2 to 1.1 kb. In adult bovine liver, a major IGF-II transcript of 4.4 kb was expressed that could not be detected in any fetal or adult extra-hepatic tissue. During fetal life, quantitative IGF-II mRNA expression differed in liver and muscle, and the relative amounts of the different transcripts varied with the tissue of origin. These observations suggest that the regulation of bovine IGF-II gene expression is specific to the stage of development and the tissue concerned. Moreover its pattern is very similar to that in its human counterpart. In order to identify a putative homology between human and bovine gene structures, bovine mRNAs were examined for cross-hybridization with various non-coding exons of the human gene. Cross-hybridization was detected with human untranslated exons 5 and 6, suggesting the presence of two distinct promoters similar to the human promoters P3 and P4. The 4.4 kb mRNA species expressed in adult bovine liver failed to hybridize to a probe for human exons 1 and 2, suggesting that the leader sequences of this transcript were different from those present in the human gene. Finally, results obtained with a probe containing the 3' untranslated end of exon 9 suggested the presence of at least two polyadenylation sites in the bovine gene. Although differences in IGF-II gene structures were found between cattle and man, the similarities in the pattern of gene expression between the two species suggest that cattle may be a useful model to investigate some developmental aspects of the expression of the human IGF-II gene.

show abstract

“…Hepatomas have been shown to overexpress IGF-II [8,9], and more recently, IGF-II expression has been implicated in an animal model of hepatocellular carcinoma [10]. Similarly, IGF expression has been described in other tumors, including lung [11,12], colon [13], and ovarian cancer [14].…”

Section: Introduction --Insulin-like Growth Factors In Malignancymentioning

confidence: 99%

Insulin-like growth factor expression in breast cancer epithelium and stroma

Cullen

Allison

Martire

et al. 1992

Breast Cancer Res Tr

View full text Add to dashboard Cite

The insulin-like growth factors (IGFs) are mitogens for many cancer cell types. In breast cancer cells, IGF-I and IGF-II have both been shown to stimulate cell proliferation. However, IGF-I mRNA has not been found in human breast cancer cell lines, making it unlikely that IGF-I is commonly expressed as an autocrine growth factor for breast cancer cells. Nevertheless, IGF-I mRNA can be detected in breast cancer tissue samples, and in situ hybridization studies have shown that the message originates from the stromal cells adjacent to normal lobules. IGF-II, on the other hand, has been detected in some breast cancer cell lines. In the estrogen receptor positive cell line T47-D, IGF-II mRNA was induced by estradiol. Furthermore, transfection of an IGF-II expression vector into a previously estrogen-dependent cell line resulted in hormone independent growth. Thus, IGF-II can be expressed as an autocrine growth factor in some breast cancers and its expression may, in part, result in hormone independence. Finally, stromal cells obtained from breast tissues showed that IGF-I was commonly expressed in fibroblasts derived from non-malignant biopsy specimens, while IGF-II mRNA was detected in fibroblasts adjacent to malignant tissue. These studies suggest that IGF-II expression may be important in both autocrine and paracrine regulation of breast cancer cell growth.

show abstract

Transcriptional deviation of the rat insulin-like growth factor II gene initiated at three alternative leader-exons between neonatal tissues and ascites hepatomas

Cited by 36 publications

References 30 publications

Characterization of the Linked Ovine Insulin and Insulin-Like Growth Factor-II Genes

Characterization of the Linked Ovine Insulin and Insulin-Like Growth Factor-II Genes

Developmental regulation of bovine insulin-like growth factor-II (IGF-II) gene expression: homology between bovine transcripts and human IGF-II exons

Insulin-like growth factor expression in breast cancer epithelium and stroma

Contact Info

Product

Resources

About