The discovery of large numbers of long non-coding RNAs (lncRNAs) has been driven by genome-wide transcriptional analyses. Compared to small ncRNAs, lncRNAs have been shown to harbor biological activities, but the functions of the great majority of lncRNAs are not known. There is growing evidence that lncRNAs can regulate gene expression at epigenetic, transcription, and post-transcription levels and widely take part in various physiological and pathological processes, such as participating in cell development, immunity, oncogenesis, clinical disease processes, etc. Here, the current research efforts on the function of lncRNA in recent years were summarized.

MicroRNAs (miRNAs) are a class of 18-27-nucleotides single-stranded RNA molecules that regulate gene expression at the post-transcriptional level. It has been demonstrated that miRNAs regulate a variety of physiological functions, including development, cell differentiation, proliferation, and apoptosis. There are growing evidence showed that miRNAs can affect the genesis and development of tumor and play a kind of tumor suppressor or oncogenic function by regulating its targetted gene-related signal pathway. miRNA-21 is one of the early discovered miRNAs in human cells, and the expression of miRNA-21 is significantly upregulated in different kinds of solid tumors. Its abnormal expression levels are closely associated with pathogenesis of cancers. This review summarizes the recent study on the field of miRNA-21 and its association with cancer.

Recently, using large-scale genomic sequencing, a great number of small noncoding RNAs (ncRNA) has been discovered. Short ncRNAs can be classified into three major classes--small interfering RNA (siRNA), microRNA (miRNA), and piwi-interacting RNA (piRNA). These short ncRNAs ranging from 20 to 300 nt in size are now recognized as a new paradigm of gene regulation for controlling many biological processes. In this paper, we review the biogenesis and recent research on the functions of small regulatory non-coding RNAs and aim at understanding their important functions in living organisms.

Glioblastoma multiforme (GBM) is an incurable malignant brain tumor, usually fatal within 1 year of diagnosis. Using a syngeneic rat 9L gliosarcoma model, we have developed a novel drug delivery method in which naked plasmid DNA is selectively targeted to brain tumors via intra-arterial injection. Using a plasmid encoding the antiangiogenic endostatin, transgene expression can be detected in tumor cells in vivo, and therapeutic efficacy is observed. Administration of this plasmid resulted in an 80% tumor volume reduction 1 week after treatment and enhanced survival time by up to 47%.Treated tumors exhibited a 40% decrease in the number of tumor vessels; ultrastructural analysis of remaining tumor vessels demonstrated a number of changes including markedly narrowed or collapsed lumens. We conclude that intra-arterial injection of plasmids selectively targets therapeutic genes to CNS neoplasms. This method of gene therapy holds promise for the treatment of these highly malignant brain tumors.