Resistance to platinum-based chemotherapy in lung cancer cell lines.
OBJECTIVE
A series of six lung cancer cell lines of different cell origin (including small cell and mesothelioma) were characterized immunohistochemically and the role of a series of protein candidates previously implicated in drug resistance were investigated.


METHODS
These include colony-forming and cell growth assays, immunohistochemistry, siRNA knockouts, real-time PCR and western blots.


RESULTS
No correlation was found with AKT, HO-1, HO-2, GRP78, 14-3-3zeta and ERCC1 levels and cisplatin nor oxaliplatin cytotoxicity, but an association was observed with levels of the enzyme, dihydrodiol dehydrogenase (DDH); an enzyme previously implicated in the development of platinum resistance. The relationship appeared to hold true for those cell lines derived from lung epithelial primary tumors but not for the neuroendocrine/small-cell and mesothelioma cell lines. siRNA knockouts to DDH-1 and DDH-2 were prepared with the cell line exhibiting the greatest resistance to cisplatin (A549) resulting in marked decreases in the DDH isoforms as assessed by real-time PCR, western blot and enzymatic activity. The DDH-1 knockout was far more sensitive to cisplatin than the DDH-2 knockout.


CONCLUSIONS
Thus, sensitivity to cisplatin appeared to be associated with DDH levels in epithelial lung cancer cell lines with the DDH-1 isoform producing the greatest effect. Results in keeping with transfection experiments with ovarian and other cell lines.
North Shore-Long Island Jewish Health System, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA.
Jianli
J
Chen
Nashwa
N
Emara
Charalambos
C
Solomides
Hemant
H
Parekh
Henry
H
Simpkins
D000230:Adenocarcinoma / Q000188:drug therapy; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy; D018288:Carcinoma, Small Cell / Q000188:drug therapy; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D000091342:Endoplasmic Reticulum Chaperone BiP; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000235:genetics; D007150:Immunohistochemistry; D020128:Inhibitory Concentration 50; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D008654:Mesothelioma / Q000188:drug therapy; D009944:Organoplatinum Compounds / Q000494:pharmacology; D000077150:Oxaliplatin; D017671:Platinum Compounds / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014410:Tumor Stem Cell Assay; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
D002945:Cisplatin; D000091342:Endoplasmic Reticulum Chaperone BiP; D006913:Hydroxysteroid Dehydrogenases; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D017671:Platinum Compounds; C000717247:HSPA5 protein, human; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)