[Expression and clinical significance of mdr-1 gene in lymphoma].
OBJECTIVE
It is still unclear whether overexpression of mdr-1 gene play a role in the chemotherapy resistance of lymphoma. This study was designed to investigate P-glycoprotein(P-gp) and mdr-1 mRNA levels of lymphoma and to observed the impact of P-gp level upon chemotherapy response.


METHODS
Ten samples of relapsed lymphoma and 21 samples of untreated lymphoma were assessed by flow cytometry(FCM). The mdr-1 mRNA levels were determined by real-time reverse-transcription PCR assay simultaneously in eighteen samples. The impact of P-gp levels upon chemotherapy response was observed in seventeen patients.


RESULTS
Nineteen Percent (4/21) patients overexpressed P-gp at diagnosis as compared to 60%(6/10) in relapse(P = 0.012). The copy numbers of mdr-1 mRNA were 4 x 10(2)-1.32 x 10(4) copies/microgram RNA in untreated group and 4 x 10(2)-4 x 10(4) copies/microgram RNA in recurrent group. There existed significant difference in the distribution of mdr-1 mRNA expression between these two groups, P < 0.05. The complete response rates were 46% (6/13) in P-gp non-overexpression group and 25% (1/4) in P-gp overexpression group(P = 0.60).


CONCLUSIONS
Relapsed lymphomas highly express P-gp and mdr-1 mRNA. The overexpression of mdr-1 gene may play a role in the multidrug resistance of relapsed lymphoma.
Tian
Wei-hua
WH
Department of Medicine, Cancer Center, Sun Yat-sen University, Guangzhou 510060, P. R. China.
Feng
Hai-lin
HL
Gao
Jing-song
JS
Jiang
Wen-qi
WQ
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008223:Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009364:Neoplasm Recurrence, Local; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D012333:RNA, Messenger