[Intercellular transfer of P-glycoprotein in hepatocellular cell line HepG2].
OBJECTIVE
To investigate whether there is intercellular transfer of functional P-glycoprotein(P-gp) from P-gp-positive cells to P-gp-negative cells in vitro.


METHODS
HepG2/GFP cells, a HepG2 cell line stably expressing GFP, were co-cultured with HepG2/ADM cells, an adriamycin-resistant cell line derived from HepG2 cells. The distribution of P-gp in hepatocellular carcinoma cell was observed under laser scanning confocal microscope (LSCM). Immunomagnetic beads were used to separate HepG2/GFP cells from the mixed culture. The abundance of P-gp was analyzed by western blot, and the expression of mdr1 mRNA was detected by qRT-PCR.


RESULTS
Yellow fluorescence was detected in HepG2/aqMDR cells, green fluorescence was detected in HepG2/GFP cells, red fluorescence was detected in HepG2/ADM cells by LSCM. The level of P-gp protein in HepG2/aqMDR cells was lower than that in HepG2/ADM cells, but higher than that in HepG2/GFP cells (q = 35.07, P < 0.05) and HepG2 cells (q = 36.87, P < 0.05). The expression of mdr1 mRNA in HepG2/ADM cells was higher than that in HepG2/aqMDR, HepG2 and HepG2/GFP cells, but there was no significant difference in mdr1 mRNA among HepG2/aqMDR, HepG2 and HepG2/GFP cells (F = 2.30, P > 0.05).


CONCLUSIONS
P-gp can transfer from drug resistant hepatocellular cells to sensitive hepatocellular carcinoma cells. This study suggests a novel mechanism of multidrug resistance in hepatocellular carcinoma.
Chen
Long
L
Department of Gastroenterology, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
Zuo
Guo-qing
GQ
Wu
Jin-feng
JF
Zeng
Gui-li
GL
Li
Tao
T
Liu
Zuo-jin
ZJ
Tang
Kai-fu
KF
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018920:Coculture Techniques / Q000379:methods; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D019450:Genes, MDR; D049452:Green Fluorescent Proteins; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010957:Plasmids; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D004317:Doxorubicin