Hydrogen peroxide alters splicing of soluble guanylyl cyclase and selectively modulates expression of splicing regulators in human cancer cells.
BACKGROUND
Soluble guanylyl cyclase (sGC) plays a central role in nitric oxide (NO)-mediated signal transduction in the cardiovascular, nervous and gastrointestinal systems. Alternative RNA splicing has emerged as a potential mechanism to modulate sGC expression and activity. C-α1 sGC is an alternative splice form that is resistant to oxidation-induced protein degradation and demonstrates preferential subcellular distribution to the oxidized environment of endoplasmic reticulum (ER).


RESULTS
Here we report that splicing of C-α1 sGC can be modulated by H(2)O(2) treatment in BE2 neuroblastoma and MDA-MD-468 adenocarcinoma human cells. In addition, we show that the H(2)O(2) treatment of MDA-MD-468 cells selectively decreases protein levels of PTBP1 and hnRNP A2/B1 splice factors identified as potential α1 gene splicing regulators by in silico analysis. We further demonstrate that down-regulation of PTBP1 by H(2)O(2) occurs at the protein level with variable regulation observed in different breast cancer cells.


CONCLUSIONS
Our data demonstrate that H(2)O(2) regulates RNA splicing to induce expression of the oxidation-resistant C-α1 sGC subunit. We also report that H(2)O(2) treatment selectively alters the expression of key splicing regulators. This process might play an important role in regulation of cellular adaptation to conditions of oxidative stress.
Department of Endocrine Neoplasia and Hormonal Disorders, MD Anderson Cancer Center, Houston, Texas, United States of America.
Gilbert J
GJ
Cote
Wen
W
Zhu
Anthony
A
Thomas
Emil
E
Martin
Ferid
F
Murad
Iraida G
IG
Sharina
D017398:Alternative Splicing / Q000187:drug effects*; D045744:Cell Line, Tumor; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006162:Guanylate Cyclase / Q000235:genetics* / Q000378:metabolism; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology* / Q000633:toxicity; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism; D059748:Proteolysis / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism; D000071756:Soluble Guanylyl Cyclase
D034441:Heterogeneous-Nuclear Ribonucleoproteins; C450006:PTBP1 protein, human; D018160:Receptors, Cytoplasmic and Nuclear; D038941:Polypyrimidine Tract-Binding Protein; D006861:Hydrogen Peroxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase