YC-1 targeting of hypoxia-inducible factor-1α reduces RGC-5 cell viability and inhibits cell proliferation.
OBJECTIVE
The survival of retinal ganglion cells (RGCs) is a hallmark of many optic neurodegenerative diseases such as glaucoma. YC-1, a potential anticancer drug, is known to be able to decrease the stability and protein expression of hypoxia-inducible factor (HIF)-1α that is triggered by hypoxia and related to RGC survival. We hypothesized that YC-1 may alter RGC cell viability through the down-regulation of HIF-1α.


METHODS
Cell viability of the RGC-5 cell line was measured with a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Flow cytometry, a LIVE/DEAD viability assay, and high-content screening (HCS) with MKI67 (K(i)-67) monoclonal antibodies were used to detect cell death and cellular proliferation.


RESULTS
We found that cells treated with 20 µM YC-1 for 24 h decreased the HIF-1α level in an RGC-5 cell line using immunoblotting and reduced the live cell number in an MTT assay. Results of flow cytometry and HCS demonstrated that reducing the cell proliferation of RGC-5 cells, not cell death, led to the decreased level in the MTT assay.


CONCLUSIONS
Our findings demonstrate that YC-1-induced down-regulation of HIF-1α might reduce RGC cell proliferation and viability under normoxia, which implies a role of YC-1 in the neuroprotective effect for further clinical applications.
Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Leo
L
Tsui
Tsorng-Harn
TH
Fong
I-Jong
IJ
Wang
D000906:Antibodies / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000037:antagonists & inhibitors* / Q000235:genetics; D007191:Indazoles / Q000494:pharmacology*; D019394:Ki-67 Antigen / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
D000906:Antibodies; D000970:Antineoplastic Agents; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007191:Indazoles; D019394:Ki-67 Antigen; D012333:RNA, Messenger; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole