Noncoding RNAs: Different roles in tumorigenesis

Abstract

A major portion of the mammalian genome is transcribed to produce large numbers of noncoding RNAs (ncRNAs). During the past decade, the discovery of small RNAs, including the microRNAs (miRNA) and small interfering RNAs (siRNA), has led to important advances in biology. The breadth of the ncRNA field of study has substantially expanded and many recent results have revealed a range of functions that can be attributed to the miRNAs and other ncRNAs. For example, H19 RNA, HOTAIR RNA, transcribed ultraconserved regions (T-UCRs), natural antisense RNA, transfer RNA and mitochondrial noncoding RNA have been suggested to play important roles in cancers and other diseases as well as in diverse cellular processes. In this review, we focus on the current status of several classes of ncRNAs associated with cancer with the emphasis on those that are not microRNAs. Mounting evidence has revealed that a major portion of the mammalian genome is transcribed to produce large numbers of noncoding RNAs (ncRNAs), that is, RNAs that either do not have an open reading frame or RNAs that have a short poorly conserved open reading frame and do not code for a protein [1,2]. During the past decade, the discovery of small RNAs including the microRNAs (miRNAs) and small interfering RNAs (siRNAs) has led to major advances in biology. After miRNAs were first connected to cancer pathogenesis [3], accumulating data have pointed to a central regulatory role for miRNAs in the initiation and progression of most of the cancers that have been analyzed so far. Recently, the breadth of the ncRNA field of study has substantially expanded. A series of studies have revealed the essential roles of many ncRNAs in diverse cellular processes including cancer; these ncRNAs include H19 RNA, HOTAIR RNA, transcribed ultraconserved regions (T-UCRs), natural antisense RNA, transfer RNA and mitochondrial noncoding RNA (Figure 1). In this review, we focus on the current status of the research into the several classes of ncRNAs associated with cancer.

Primate-Specific Long Non-Coding RNAs and MicroRNAs

“…Thus, the number of primate- or even human-specific miRNAs is large. Due to space limitation, we have not mentioned primate-specific miRNAs that are involved in cancer progression [22] or other cellular functions [57] , [58] .…”

Overexpression of WRAP53 Is Associated with Development and Progression of Esophageal Squamous Cell Carcinoma

“…Natural antisense transcripts (NATs), also called antisense RNAs, are RNAs that contain sequences that are complementary to other endogenous transcripts. Antisense RNAs may also encode proteins or may exist only as non-protein-coding transcripts [1] , [2] . In recent years, investigations into NAT functions have indicated that NATs play key roles in carcinogenesis and the development of cancers [3] – [9] .…”

Environmental RNA interference in animals

“…Environmental RNAi has been extensively applied in research with C. elegans, but its application in biotechnology and therapeutics requires further development. Research in environmental RNAi will no doubt be an active branch to continuously bring novel insights in the years to come, as the whole field of noncoding RNA research is moving fast forward [86][87][88][89][90].…”