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Identification of mRNAs differentially-expressed between benign and malignant breast tumour cells.

Liu D, Rudland PS, Sibson DR, Barraclough R - Br. J. Cancer (2002)

Bottom Line: One such oestrogen-responsive expressed sequence tag, M41, is transcribed from a gene located on chromosome 21q22.3, within an intron of a larger gene.The M41 gene contains oestrogen response elements, one of which is associated with alu repeats.M41 mRNA is expressed at a statistically significantly higher level in human breast cancer specimens than in normal human breast and benign lesions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Life Sciences Building, University of Liverpool, PO Box 147, Liverpool L69 7ZB, UK.

ABSTRACT
Two suppression subtracted cDNA libraries have been constructed, one containing cDNAs to mRNAs present at a higher level in a benign human breast tumour-derived cell line relative to the malignant mammary cell line, MCF-7, and the other containing cDNAs present at a higher level in the MCF-7 cells relative to the benign cells. Randomly-picked cloned DNAs have been sequenced yielding 29 and 128 different cDNAs from the benign and malignant libraries, respectively. Using reverse Northern hybridisation, 76% and 83% of the cDNAs were differentially expressed by greater than two-fold, whilst 14% and 11% of cDNAs in the respective libraries were differentially expressed by more than 15-fold. Amongst these were oestrogen-responsive cDNAs and expressed sequence tags. One such oestrogen-responsive expressed sequence tag, M41, is transcribed from a gene located on chromosome 21q22.3, within an intron of a larger gene. The M41 gene contains oestrogen response elements, one of which is associated with alu repeats. M41 mRNA is expressed at a statistically significantly higher level in human breast cancer specimens than in normal human breast and benign lesions. In carcinomas, its up-regulation is associated with the development of the malignant cell.

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In situ hybridisation of M41 mRNA in human breast tumours. Histological sections of breast carcinoma specimens (A–G), and of one benign tumour specimen (H) were subjected to in situ hybridisation using antisense (A, C, E, G, H) or sense (B, D, F) probes to M41 mRNA as described in Materials and Methods. The carcinoma cells in the specimens in A, C, E and G stain with an antisense probe of M41 cRNA, whereas there was no staining of adjacent sections of the specimens with sense M41 RNA probe (B, D, F). (H) shows an example of a fibroadenoma which did not stain with an antisense probe, in common with four other fibroadenomas tested. Magnification is ×231 (A–D, F) or ×578 (E, G, H). Bars=43 μm (A–D, F) or 17 μm (E, G, H).
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fig3: In situ hybridisation of M41 mRNA in human breast tumours. Histological sections of breast carcinoma specimens (A–G), and of one benign tumour specimen (H) were subjected to in situ hybridisation using antisense (A, C, E, G, H) or sense (B, D, F) probes to M41 mRNA as described in Materials and Methods. The carcinoma cells in the specimens in A, C, E and G stain with an antisense probe of M41 cRNA, whereas there was no staining of adjacent sections of the specimens with sense M41 RNA probe (B, D, F). (H) shows an example of a fibroadenoma which did not stain with an antisense probe, in common with four other fibroadenomas tested. Magnification is ×231 (A–D, F) or ×578 (E, G, H). Bars=43 μm (A–D, F) or 17 μm (E, G, H).

Mentions: In order to find out whether M41 mRNA is expressed in human tumour specimens, in situ hybridisation was carried out (Figure 3) using sense and antisense probes derived from the region of the M41 clone spanning two exons (Figure 2). Whereas there was no hybridisation to any of the specimens with the sense probe, the antisense probe yielded strong hybridisation in the carcinoma cells of 10 carcinoma specimens and three specimens were negative. There was no statistically significant correlation between M41 positivity and oestrogen receptor positivity for these samples (P=1.00, two-tailed Fisher Exact test). In contrast, there was no staining using the antisense probe on a benign fibroadenoma (Figure 3), nor on four other fibroadenoma specimens examined. There was a statistically significant difference between the benign and malignant samples for M41 mRNA positivity (P=<0.007, two-tailed Fisher Exact test). Using a sensitive reverse transcript PCR (RT–PCR) assay which yielded an M41-specific 147 bp product (Figure 4Figure 4


Identification of mRNAs differentially-expressed between benign and malignant breast tumour cells.

Liu D, Rudland PS, Sibson DR, Barraclough R - Br. J. Cancer (2002)

In situ hybridisation of M41 mRNA in human breast tumours. Histological sections of breast carcinoma specimens (A–G), and of one benign tumour specimen (H) were subjected to in situ hybridisation using antisense (A, C, E, G, H) or sense (B, D, F) probes to M41 mRNA as described in Materials and Methods. The carcinoma cells in the specimens in A, C, E and G stain with an antisense probe of M41 cRNA, whereas there was no staining of adjacent sections of the specimens with sense M41 RNA probe (B, D, F). (H) shows an example of a fibroadenoma which did not stain with an antisense probe, in common with four other fibroadenomas tested. Magnification is ×231 (A–D, F) or ×578 (E, G, H). Bars=43 μm (A–D, F) or 17 μm (E, G, H).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2376136&req=5

fig3: In situ hybridisation of M41 mRNA in human breast tumours. Histological sections of breast carcinoma specimens (A–G), and of one benign tumour specimen (H) were subjected to in situ hybridisation using antisense (A, C, E, G, H) or sense (B, D, F) probes to M41 mRNA as described in Materials and Methods. The carcinoma cells in the specimens in A, C, E and G stain with an antisense probe of M41 cRNA, whereas there was no staining of adjacent sections of the specimens with sense M41 RNA probe (B, D, F). (H) shows an example of a fibroadenoma which did not stain with an antisense probe, in common with four other fibroadenomas tested. Magnification is ×231 (A–D, F) or ×578 (E, G, H). Bars=43 μm (A–D, F) or 17 μm (E, G, H).
Mentions: In order to find out whether M41 mRNA is expressed in human tumour specimens, in situ hybridisation was carried out (Figure 3) using sense and antisense probes derived from the region of the M41 clone spanning two exons (Figure 2). Whereas there was no hybridisation to any of the specimens with the sense probe, the antisense probe yielded strong hybridisation in the carcinoma cells of 10 carcinoma specimens and three specimens were negative. There was no statistically significant correlation between M41 positivity and oestrogen receptor positivity for these samples (P=1.00, two-tailed Fisher Exact test). In contrast, there was no staining using the antisense probe on a benign fibroadenoma (Figure 3), nor on four other fibroadenoma specimens examined. There was a statistically significant difference between the benign and malignant samples for M41 mRNA positivity (P=<0.007, two-tailed Fisher Exact test). Using a sensitive reverse transcript PCR (RT–PCR) assay which yielded an M41-specific 147 bp product (Figure 4Figure 4

Bottom Line: One such oestrogen-responsive expressed sequence tag, M41, is transcribed from a gene located on chromosome 21q22.3, within an intron of a larger gene.The M41 gene contains oestrogen response elements, one of which is associated with alu repeats.M41 mRNA is expressed at a statistically significantly higher level in human breast cancer specimens than in normal human breast and benign lesions.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, Life Sciences Building, University of Liverpool, PO Box 147, Liverpool L69 7ZB, UK.

ABSTRACT
Two suppression subtracted cDNA libraries have been constructed, one containing cDNAs to mRNAs present at a higher level in a benign human breast tumour-derived cell line relative to the malignant mammary cell line, MCF-7, and the other containing cDNAs present at a higher level in the MCF-7 cells relative to the benign cells. Randomly-picked cloned DNAs have been sequenced yielding 29 and 128 different cDNAs from the benign and malignant libraries, respectively. Using reverse Northern hybridisation, 76% and 83% of the cDNAs were differentially expressed by greater than two-fold, whilst 14% and 11% of cDNAs in the respective libraries were differentially expressed by more than 15-fold. Amongst these were oestrogen-responsive cDNAs and expressed sequence tags. One such oestrogen-responsive expressed sequence tag, M41, is transcribed from a gene located on chromosome 21q22.3, within an intron of a larger gene. The M41 gene contains oestrogen response elements, one of which is associated with alu repeats. M41 mRNA is expressed at a statistically significantly higher level in human breast cancer specimens than in normal human breast and benign lesions. In carcinomas, its up-regulation is associated with the development of the malignant cell.

Show MeSH
Related in: MedlinePlus