title: Expression of mdr1 gene in human breast primary tumors and metastases.
abstract: Expression of mdr1 gene has been evaluated in 34 tumor samples obtained from breast cancer patients who were classified according to their treatment, and clinical follow-up. No gene amplification was found. mdr1-RNA was never detected in 29 primary breast tumors including 5 samples from patients previously treated by 6 courses of 5-fluorouracil, epirubicin, cyclophosphamide (FEC). On the other hand, mdr1-RNA expression was detected in 1 local recurrence and 2 out of 3 metastases, all of them being treated and exhibiting a poor evolution. A second, untreated local recurrence remained negative. Clinical follow-up for 7 to 48 months in patients receiving chemotherapy showed that absence of mdr1-RNA could not be an accurate factor of satisfactory response to chemotherapy. But, all the patients with detectable mdr1-RNA exhibited a poor evolution and response to treatment. In conclusion, evaluation of mdr1-RNA seemed to be of little interest in primary breast tumors. However, the concomitant presence of an mdr1-RNA and a metastatic phenotype could give a new insight into the relationship between invasive and resistance properties of cancer cells. Such situations would need to be analyzed very carefully for a better utilization of chemotherapy.
authors.affiliation: GIBSA, Laboratoire de Biochemie, Institut Jean Godinot, Reims, France.
authors.forename: E
authors.initials: E
authors.lastname: Hennequin
authors.forename: C
authors.initials: C
authors.lastname: Delvincourt
authors.forename: C
authors.initials: C
authors.lastname: Pourny
authors.forename: J C
authors.initials: JC
authors.lastname: Jardillier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015152:Blotting, Northern; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000235:genetics*; D006801:Humans; D015151:Immunoblotting; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics / Q000556:secondary; D010997:Pleural Neoplasms / Q000235:genetics / Q000556:secondary; D012334:RNA, Neoplasm / Q000032:analysis / Q000235:genetics*
chemical_list: D012334:RNA, Neoplasm