A partial fragment of novel sequence (arr, adriamycin-resistant related) was previously identified using the differential display (DD)-PCR technique with adriamycin-resistant L1210 variant (L1210AdR), which shows a typical multidrug resistant (MDR) phenotypes. The present research shows the isolation of full length arr cDNA sequence. To clone the full length cDNA of arr gene, DD-PCR fragments were subjected to 5'- and 3'-Rapid Amplification of cDNA End (RACE) method. The cloned arr cDNA consisted of 770 bases and contained an open reading frame of 153 bases, encoding a protein of 51 amino acid with the molecular mass of 4 kDa by in vitro translation reactions. Northern blot analysis showed that a 770 bases transcript arr gene was overexpressed in adriamycin-resistant L1210 variant, but not in the parent suggesting that the arr gene may be involved in the adriamycin-resistant phenotypes.
Amino Acid Sequence ; Animal ; Base Sequence ; Blotting, Northern ; Cloning, Molecular ; DNA Primers ; Doxorubicin/pharmacology* ; Drug Resistance, Neoplasm/genetics* ; Gene Expression Regulation, Neoplastic ; Glycoproteins/genetics* ; Leukemia L1210/genetics* ; Leukemia L1210/drug therapy ; Mice ; Molecular Sequence Data ; Translation, Genetic

OBJECTIVETo clone and identify MF-1 gene which responded to extremely low frequency magnetic fields(ELF MF) in Daudi cells, and explore the response universality of MF-1 gene in several MF-sensitive cell lines, so as to provide experimental basis for revealing the mechanism of biological effects induced by magnetic field.

METHODSThe DNA fragment of MF-1 was cloned and sequenced; the mRNA level of MF-1 gene were analysed in MF-sensitive cell lines(HL-60, L1210 and CHL) by Northern blot after these cells being treated with 0.1 mT and 0.8 mT MF for 20 minutes and 24 hours, respectively.

RESULTSThe MF-1 cDNA sequence had 100% homology with cytochrome oxidase subunit 1 gene(CO1) by searching Gene Bank database; the transcription of CO1 in HL-60, L1210 and CHL cell lines which exposed to 0.1 mT and 0.8 mT MF for 20 minutes were significantly lower(0.38 +/- 0.12 and 0.37 +/- 0.04) than that of control(0.58 +/- 0.12) and so did for 24 hours exposure(0.46 +/- 0.09 and 0.45 +/- 0.09 vs 0.65 +/- 0.06) (P < 0.05).

CONCLUSIONCO1 is a MF-responsive gene. Cytochrome oxidase activity may be affected through low level of CO1 transcription by magnetic fields, thus induce bioeffects in organisms.

Animals ; Cricetinae ; Electron Transport Complex IV ; genetics ; metabolism ; radiation effects ; HL-60 Cells ; Humans ; Leukemia L1210 ; Magnetics ; Mice ; Protein Subunits ; RNA, Messenger ; analysis ; Transcription, Genetic ; radiation effects

The aim of this study was to explore the molecule mechanism of resveratrol antileukaemia. The mouse lymphocytic leukemia L1210 cells were cultured and the expressions of pJAK1 and pSTAT3 protein in L1210 cells were detected by immunohistochemistry and immunoprecipitation in vitro. The mouse model with L1210 leukemia ascites carcinoma was established and activities of singal transduction pathway molecules pJAK1 and pSTAT3 were measured by Western blot and immunohistochemistry assay in vitro. The results indicated that resveratrol could significantly inhibit the JAK1/STAT3 signal transduction pathway, down-regulate expressions of pJAK1 and pSTAT3 and reduce the phosphorylation of JAK1 and STAT3 in a dose-and time-dependent manner. It is concluded that the resveratrol can regulate signal transduction pathway and reduce the activation of JAK1/STAT3 tyrosine phosphorylation significantly, and therefore resveratrol shows chemotherapeutic potential to leukaemia.
Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Down-Regulation ; Janus Kinase 1 ; genetics ; metabolism ; Leukemia L1210 ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Random Allocation ; STAT3 Transcription Factor ; genetics ; metabolism ; Signal Transduction ; drug effects ; Stilbenes ; pharmacology