TUC338 is an ultra-conserved element

Ultra-conserved element

An ultra-conserved element is a region of human DNA of length 200 nucleotides or greater, which is entirely conserved in both rats and mice...

 which is transcribed to give a non-coding RNA

Non-coding RNA

A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...

. The TUC338 gene was first identified as uc.338, along with 480 other ultra-conserved elements in the human genome

Human genome

The human genome is the genome of Homo sapiens, which is stored on 23 chromosome pairs plus the small mitochondrial DNA. 22 of the 23 chromosomes are autosomal chromosome pairs, while the remaining pair is sex-determining...

. Expression of this RNA gene has been found to dramatically increase in hepatocellular carcinoma

Hepatocellular carcinoma

Hepatocellular carcinoma is the most common type of liver cancer. Most cases of HCC are secondary to either a viral hepatitide infection or cirrhosis .Compared to other cancers, HCC is quite a rare tumor in the United States...

 (HCC) cells.

The TUC338 RNA gene is 590 base-pairs long, and partially overlaps the gene encoding Poly(rC)-binding protein 2

PCBP2

Poly-binding protein 2 is a protein that in humans is encoded by the PCBP2 gene.In humans, the PCBP2 gene overlaps with TUC338, a transcribed ultra-conserved element implicated in Hepatocellular carcinoma.-Interactions:...

 (PCBP2), a protein involved in mRNA processing. Despite this overlap, PCBP2 and TUC388 were found to be independently expressed.

TUC338 is predicted to function in cell growth

Cell growth

The term cell growth is used in the contexts of cell development and cell division . When used in the context of cell division, it refers to growth of cell populations, where one cell grows and divides to produce two "daughter cells"...

, possibly at the interface between G1 phase

G1 phase

The G1 phase is a period in the cell cycle during interphase, before the S phase. For many cells, this phase is the major period of cell growth during its lifespan. During this stage new organelles are being synthesized, so the cell requires both structural proteins and enzymes, resulting in great...

 and S phase

S phase

S-phase is the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease. Due to the importance, the regulatory pathways that govern this...

, and could potentially present a therapeutic target to treat HCC cells. Experimental evidence shows knocking out

Gene knockout

A gene knockout is a genetic technique in which one of an organism's genes is made inoperative . Also known as knockout organisms or simply knockouts, they are used in learning about a gene that has been sequenced, but which has an unknown or incompletely known function...

 TUC338 using siRNA

Sírna

Sírna Sáeglach , son of Dian mac Demal, son of Demal mac Rothechtaid, son of Rothechtaid mac Main, was, according to medieval Irish legend and historical tradition, a High King of Ireland...

reduced the growth rate of both mouse and human HCC cells.