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Updated: Sep 26, 2026
Building Up a High-throughput Screening Platform to Assess the Heterogeneity of HER2 Gene Amplification in Breast Cancers
Published on: December 5, 2017
Identification of differentially expressed genes associated with HER-2/neu overexpression in human breast cancer
J J Oh1, D R Grosshans, S G Wong
1Department of Medicine, Division of Hematology and Oncology, UCLA School of Medicine, Los Angeles, CA 90095-1678, USA.
Abstract:
Amplification and resulting overexpression of the HER-2/ neu proto-oncogene is found in approximately 30% of human breast and 20% of human ovarian cancers. To better understand the molecular events associated with overexpression of this gene in human breast cancer cells, differential hybridization was used to identify genes whose expression levels are altered in cells overexpressing this receptor. Of 16 000 clones screened from an overexpression cell cDNA library, a total of 19 non-redundant clones were isolated including seven whose expression decreases (C clones) and 12 which increase (H clones) in association with HER-2/ neu overexpression. Of these, five C clones and 11 H clones have been confirmed to be differentially expressed by northern blot analysis. This group includes nine genes of known function, three previously sequenced genes of relatively uncharacterized function and four novel genes without a match in GenBank. Examination of the previously characterized genes indicates that they represent sequences known to be frequently associated with the malignant phenotype, suggesting that the subtraction cloning strategy used identified appropriate target genes. In addition, differential expression of 12 of 16 (75%) cDNAs identified in the breast cancer cell lines are also seen in HER-2/ neu -overexpressing ovarian cancer cells, indicating that they represent generic associations with HER-2/ neu overexpression. Finally, up-regulation of two of the identified cDNAs, one novel and one identified but as yet uncharacterized gene, was confirmed in human breast cancer specimens in association with HER-2/ neu overexpression. Further characterization of these genes may yield insight into the fundamental biology and pathogenetic effects of HER-2/ neu overexpression in human breast and ovarian cancer cells.
Insights
Researchers identified genes altered by HER-2/neu overexpression in breast and ovarian cancers. This study reveals key molecular changes, offering insights into cancer biology and potential therapeutic targets for HER-2/neu-driven malignancies.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- HER-2/neu proto-oncogene amplification and overexpression are common in breast (30%) and ovarian (20%) cancers.
- Understanding molecular events linked to HER-2/neu overexpression is crucial for cancer research.
Purpose of the Study:
- To identify genes with altered expression in breast cancer cells overexpressing HER-2/neu.
- To investigate conserved molecular alterations in ovarian cancer associated with HER-2/neu overexpression.
Main Methods:
- Differential hybridization was employed to screen a cDNA library from HER-2/neu-overexpressing cells.
- Northern blot analysis was used to confirm differential gene expression.
- Genomic screening against GenBank was performed for identified clones.
Main Results:
- 19 non-redundant clones were isolated, with 7 showing decreased (C clones) and 12 increased (H clones) expression.
- Northern blot confirmed differential expression in 16 clones (5 C, 11 H).
- Of the 16 confirmed clones, 12 (75%) showed similar differential expression in HER-2/neu-overexpressing ovarian cancer cells.
- Up-regulation of two cDNAs (one novel, one uncharacterized) was confirmed in human breast cancer specimens with HER-2/neu overexpression.
Conclusions:
- The subtraction cloning strategy successfully identified genes associated with the malignant phenotype.
- Identified genes represent generic associations with HER-2/neu overexpression across different cancer types.
- Further characterization of these genes may elucidate fundamental biological and pathogenetic effects of HER-2/neu overexpression in breast and ovarian cancers.
