Transcribed ultraconserved regions (T-UCRs) classified as long non-coding RNAs 
(Lnc-RNAs) are transcripts longer than 200-nt RNA with no protein-coding 
capacity. Previous studies showed that T-UCRs serve as novel oncogenes, or tumor 
suppressors are involved in tumorigenesis and cancer progressive. Nevertheless, 
the clinicopathologic significance and regulatory mechanism of T-UCRs in lung 
cancer (LC) remain largely unknown. We found that uc.454 was downregulated in 
both non-small-cell LC (NSCLC) tissues and LC cell lines, and the downregulated 
uc.454 is associated with tumor size and tumors with more advanced stages. 
Transfection with uc.454 markedly induced apoptosis and inhibited cell 
proliferation in SPC-A-1 and NCI-H2170 LC cell lines. Above results suggested 
that uc.454 played a suppressive role in LC. Heat shock protein family A member 
12B (HSPA12B) protein was negatively regulated by uc.454 at the 
posttranscriptional level by dual-luciferase reporter assay and affected the 
expressions of Bcl-2 family members, which finally induced LC apoptosis. The 
uc.454/HSPA12B axis furthers our understanding of the molecular mechanisms 
involved in tumor apoptosis, which may potentially serve as a therapeutic target 
for lung carcinoma.