[The relationship between in vitro chemosensitivity of human breast cancer to MDR related drugs and expression of mdr-1 gene].
OBJECTIVE
To study the relationship between in vitro chemosensitivity of human breast cancer to MDR related drugs and expression of mdr-1 gene.


METHODS
We measured the chemosensitivity of 56 human breast cancers to MDR related drugs by MTT assay in vitro and level of mdr-1 mRNA in these samples by RT-PCR technique.


RESULTS
The expression of mdr-1 gene in the breast cancer resistant to drugs in vitro was increased significantly. The level of mdr-1 mRNA was not correlated with Imax%, but correlated with IC50 statistically.


CONCLUSIONS
These results support that the increased expression of mdr-1 gene is a major cause of resistance to MDR related drugs.
North Taiping Road Hospital Cancer Center, Beijing.
J
J
Xu
S
S
Song
X
X
Liu
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D019450:Genes, MDR; D006801:Humans; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology; D014751:Vindesine / Q000494:pharmacology
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D014750:Vincristine; D004317:Doxorubicin; D014751:Vindesine