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- Borg, A., et al.
(författare)
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Association of int2/hst1 coamplification in primary breast cancer with hormone-dependent phenotype and poor prognosis
- 1991
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 63:1, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- The human proto-oncogene INT2 (homologous to the mouse INT2 gene, implicated in proviral induced mammary carcinoma) has been mapped to chromosome llql3 and found to share band localisation with, among others, the HST1 proto-oncogene. Both genes are members of the fibroblast growth factor family. In the present study, coamplification (2-15 copies) of the INT2/HST1 genes was found in 27 (9%) of 311 invasive human breast carcinomas using slot blot and Southern blot analyses. Amplification was not correlated to tumour size, axillary lymph node status or stage of disease, neither to patient age nor menopausal status. However, 26 (96%) of the 27 amplified tumours were, often strongly, Oestrogen receptor positive compared to 65% of the unamplified cases (P = 0. 001). These findings are in sharp contrast to the strong correlations of HER-2/neu proto-oncogene amplification with advanced stage and steroid receptor negativity, previously observed in the same series of tumours. Patients with INT2/HSTI amplified breast cancer had a significantly shorter disease-free survival compared to those with unamplified genes (P = 0. 015, median follow up 45 months). This correlation was confined to node-negative patients and persisted in multivariate analysis. No significant correlation to survival from breast cancer was found. It is concluded that amplification of the 1 lql3 region in breast cancer occurs in a particular subset of aggressive tumours, quite different from that identified by HER-2/neu amplification. It still remains to be shown that the selection for amplified genes at llql3 is due to the activity of INT2, HSTl or yet another, still unidentified, neighbouring gene. However, the results are potentially of clinical value in separating a group of node-negative breast cancer for more intense treatment.
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| 2. |
- Borg, A, et al.
(författare)
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HER-2/neu amplification predicts poor survival in node-positive breast cancer
- 1990
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Ingår i: Cancer Research. - 0008-5472. ; 50:14, s. 7-4332
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Tidskriftsartikel (refereegranskat)abstract
- HER-2/neu protooncogene amplification and protein expression were analyzed with slot blot and Western blot techniques, respectively, in more than 300 invasive primary breast tumors of all stages. Amplification (2- greater than 30 copies) was found in 17% of these tumors and high expression was seen in 19%. There was a striking coincidence between gene amplification and high expression. Tumors associated with many involved axillary lymph nodes or with Stage IV disease were more often HER-2/neu amplified or overexpressed. Furthermore, gene alteration was strongly correlated with the absence of steroid receptors and with larger tumor size. High expression without gene amplification was seen in a minor subset of tumors of less aggressive character. Neither amplification nor overexpression was correlated with disease outcome for patients with negative axillary lymph nodes. For node-positive patients, however, HER-2/neu amplification was a significant predictor of early relapse and death (median follow-up = 45 months), and a similar trend, although not significant, existed for high gene expression. Multivariate analyses indicated that HER-2/neu alterations were not independent predictors of patient outcome.
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| 5. |
- Zhang, Q X, et al.
(författare)
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An exon 5 deletion variant of the estrogen receptor frequently coexpressed with wild-type estrogen receptor in human breast cancer
- 1993
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Ingår i: Cancer Research. - 0008-5472. ; 53:24, s. 4-5882
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence suggests that the expression of estrogen receptor (ER) variants in breast cancer may interfere with wild-type (wt) ER function and be related to tumor progression and resistance to hormone treatment. One of these variants, ER delta E5, lacking that part of the hormone-binding domain encoded by exon 5, has previously been identified in breast tumors with the unusual estrogen receptor negative (ER-) and progesterone receptor positive (PgR+) phenotype and found to possess constitutive and hormone-independent transcriptional activity. Using a ribonuclease protection assay, we analyzed 27 breast tumors and 4 breast cell lines for the presence of this variant. We found the ER delta E5 variant to be expressed, not only in all of three ER-/PgR+ tumors but also in 19 of 20 ER+/PgR+ or ER+/PgR- tumors. Moreover, the variant was always coexpressed with and often in excess of wtER. ER delta E5 was also found in three breast cancer cell lines (MCF7, T47D, and ZR75-1), although to a lesser extent than wtER. A complete absence of both ER delta E5 and wtER was noted in four ER-/PgR- tumors and one normal breast cell line (HBL-100). Thus, our data suggest that the occurrence of ER delta E5 in breast cancer may represent a critical stage in tumor progression to autonomy.
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