title: Growth arrest associated changes of mRNA levels in breast cancer cells measured by semi-quantitative RT-PCR: potential early indicators of treatment response.
abstract: To find early and sensitive indicators of treatment response in breast cancer, we studied the mRNA levels of proliferation-related genes during growth arrest of the human breast cancer cell lines T47D and MCF7. A sensitive reverse transcriptase-PCR (RT-PCR) technique was used in order to monitor gene expression in small samples of cells. Estrogen-depletion and treatment with tamoxifen effectively induced a G1-arrest in both cell lines, accompanied by a decrease of the mRNA levels of histone H4, cyclin A, cyclin D1, and c-myc. Cyclin A expression decreased most strongly: up to 32-fold within 7 days. The expression of c-fos and WAF1 increased during growth arrest. In conclusion, significant changes of the levels of proliferation-related mRNAs, induced by growth arrest, can be measured in small samples of breast carcinoma cells using RT-PCR. Especially the decrease of the cyclin A mRNA level seems a potential early indicator of clinical response to tamoxifen therapy in breast cancer patients.
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: R A
authors.initials: RA
authors.lastname: Maas
authors.forename: P F
authors.initials: PF
authors.lastname: Bruning
authors.forename: B
authors.initials: B
authors.lastname: Top
authors.forename: A J
authors.initials: AJ
authors.lastname: Breedijk
authors.forename: H L
authors.initials: HL
authors.lastname: Peterse
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002453:Cell Cycle; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D016762:Genes, fos; D016259:Genes, myc; D006657:Histones / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000378:metabolism; D013629:Tamoxifen / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D017931:DNA Primers; D006657:Histones; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D013629:Tamoxifen