OBJECTIVETo synthesize highly pure HBV post-transcriptional regulatory element (HPRE) via transcription in vitro by T7 RNA polymerase.

METHODSHPRE gene was amplified by PCR from a template containing HBV complete genomic DNA and cloned into plasmid pGEM-11zf. The cloned DNA sequence was transcribed by T7 RNA polymerase.

RESULTSThe construction of HPRE gene recombinant plasmid and production of HPRE via transcription in vitro was successful.

CONCLUSIONIn vitro transcription by T7 RNA polymerase can be used to synthesize highly pure HPRE.

DNA-Directed DNA Polymerase ; DNA-Directed RNA Polymerases ; Hepatitis B virus ; genetics ; RNA Processing, Post-Transcriptional ; RNA Splicing ; RNA-Binding Proteins ; physiology ; Transcription, Genetic ; Viral Proteins

Polypyrimidine tract-binding protein 1 (PTBP1) plays an essential role in splicing and is expressed in almost all cell types in humans, unlike the other proteins of the PTBP family. PTBP1 mediates several cellular processes in certain types of cells, including the growth and differentiation of neuronal cells and activation of immune cells. Its function is regulated by various molecules, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and RNA-binding proteins. PTBP1 plays roles in various diseases, particularly in some cancers, including colorectal cancer, renal cell cancer, breast cancer, and glioma. In cancers, it acts mainly as a regulator of glycolysis, apoptosis, proliferation, tumorigenesis, invasion, and migration. The role of PTBP1 in cancer has become a popular research topic in recent years, and this research has contributed greatly to the formulation of a useful therapeutic strategy for cancer. In this review, we summarize recent findings related to PTBP1 and discuss how it regulates the development of cancer cells.
Alternative Splicing ; Carcinogenesis ; Glycolysis ; Heterogeneous-Nuclear Ribonucleoproteins/physiology* ; Humans ; MicroRNAs/physiology* ; Neoplasms/pathology* ; Polypyrimidine Tract-Binding Protein/physiology* ; RNA, Long Noncoding/physiology*

A trans-splicing ribozyme which can specifically reprogram human telomerase reverse transcriptase (hTERT) RNA was previously suggested as a useful agent for tumor-targeted gene therapy. In this study, we evaluated in vivo function of the hTERT-targeting trans-splicing ribozymes by employing the molecular analysis of expression level of genes affected by the ribozyme delivery into peritoneal carcinomatosis mice model. To this effect, we constructed adenoviral vector encoding the specific ribozyme. Noticeably, more than four-fold reduction in the level of hTERT RNA was observed in tumor nodules by the systemic infection of the ribozyme-encoding virus. Such hTERT RNA knockdown in vivo induced changes in the global gene expression profile, including the suppression of specific genes associated with anti-apoptosis including bcl2, and genes for angiogenesis and metastasis. In addition, specific trans-splicing reaction with the targeted hTERT RNA took place in the tumors established as peritoneal carcinomatosis in mice by systemic delivery of the ribozyme. In conclusion, this study demonstrates that an hTERT-specific RNA replacement approach using trans-splicing ribozyme represents a potential modality to treat cancer.
Animals ; Cell Line ; Gene Expression/*physiology ; Genetic Vectors ; Humans ; Mice ; Neoplasm Metastasis ; Neoplasms/genetics/pathology ; RNA, Catalytic/genetics/*metabolism ; RNA, Messenger/genetics/metabolism ; RNA, Neoplasm/genetics/metabolism ; Telomerase/antagonists & inhibitors/genetics/*metabolism ; Trans-Splicing/*genetics

RNA helicases, the largest family of proteins that participate in RNA metabolism, stabilize the intracellular environment through various processes, such as translation and pre-RNA splicing. These proteins are also involved in some diseases, such as cancers and viral diseases. Autophagy, a self-digestive and cytoprotective trafficking process in which superfluous organelles and cellular garbage are degraded to stabilize the internal environment or maintain basic cellular survival, is associated with human diseases. Interestingly, similar to autophagy, RNA helicases play important roles in maintaining cellular homeostasis and are related to many types of diseases. According to recent studies, RNA helicases are closely related to autophagy, participate in regulating autophagy, or serve as a bridge between autophagy and other cellular activities that widely regulate some pathophysiological processes or the development and progression of diseases. Here, we summarize the most recent studies to understand how RNA helicases function as regulatory proteins and determine their association with autophagy in various diseases.
Animals ; Antiviral Agents/pharmacology* ; Autophagy ; Beclin-1/metabolism* ; Carcinogenesis ; Cell Survival ; DEAD Box Protein 58/metabolism* ; Disease Progression ; Gene Expression Regulation ; Homeostasis ; Humans ; Immune System/physiology* ; Neoplasms/metabolism* ; RNA Helicases/metabolism* ; RNA Splicing ; Receptors, Immunologic/metabolism*

Retinitis pigmentosa is a leading cause of blindness and a progressive retinal disorder, affecting millions of people worldwide. This disease is characterized by photoreceptor degeneration, eventually leading to complete blindness. Autosomal dominant (adRP) has been associated with mutations in at least four ubiquitously expressed genes encoding pre-mRNA splicing factors-Prp3, Prp8, Prp31 and PAP1. Biological function of adRP-associated splicing factor genes and molecular mechanisms by which mutations in these genes cause cell-type specific photoreceptor degeneration in humans remain to be elucidated. To investigate the in vivo function of these adRP-associated splicing factor genes, we examined Drosophila in which expression of fly Prp31 homolog was down-regulated. Sequence analyses show that CG6876 is the likely candidate of Drosophila melanogaster Prp31 homolog (DmPrp31). Predicted peptide sequence for CG6876 shows 57% similarity to the Homo sapiens Prp31 protein (HsPrp31). Reduction of the endogenous Prp31 by RNAi-mediated knockdown specifically in the eye leads to reduction of eye size or complete absence of eyes with remarkable features of photoreceptor degeneration and recapitulates the bimodal expressivity of human Prp31 mutations in adRP patients. Such transgenic DmPrp31RNAi flies provide a useful tool for identifying genetic modifiers or interacting genes for Prp31. Expression of the human Prp31 in these animals leads to a partial rescue of the eye phenotype. Our results indicate that the Drosophila CG6876 is the fly ortholog of mammalian Prp31 gene.
Amino Acid Sequence ; Animals ; Animals, Genetically Modified ; Base Sequence ; DNA Primers ; genetics ; Drosophila Proteins ; antagonists & inhibitors ; genetics ; physiology ; Drosophila melanogaster ; genetics ; growth & development ; physiology ; Eye Abnormalities ; genetics ; Eye Proteins ; antagonists & inhibitors ; genetics ; physiology ; Gene Knockdown Techniques ; Genes, Insect ; Humans ; Molecular Sequence Data ; Pancreatitis-Associated Proteins ; Photoreceptor Cells, Invertebrate ; physiology ; RNA Interference ; RNA Splicing ; Sequence Homology, Amino Acid

OBJECTIVETo investigate the changes of the human telomerase reverse transcriptase gene (hTERT) alterative splicing pattern in gastric carcinogenesis.

METHODSThree alternative splicing sites (alpha, beta, gamma) were selected to design primers. The expression of eight hTERT alternative splicing variants (ASVs) in normal gastric mucosa, precancerous lesions and gastric cancer was detected by semi-nested reverse transcription-polymerase chain reaction (RT-PCR). The expression of beta site-remaining ASV (beta (+) hTERT mRNA) in precancerous lesions and gastric cancer tissues was detected by SYBR green real-time RT-PCR.

RESULTSThe positive rate of alpha(+) beta(+)gamma(+) hTERT mRNA was significantly higher in gastric cancer than in precancerous lesions and normal mucosa (94.7% vs. 40.0% and 0, P<0.05). The positive rates of other ASVs were not different among the three groups. The positive rates of beta deletion ASV were 72.2% in normal mucosa, 95.0% in precancerous lesions and 100.0% in gastric cancer. The mRNA level of beta(+) hTERT was 5.49 folds higher in gastric cancer than in precancerous lesions.

CONCLUSIONThe hTERT alternative splicing pattern changes during gastric carcinogenesis. The beta(+) hTERT mRNA is expressed increasingly during gastric carcinogenesis and may provide useful information for diagnosis of gastric cancer or precancerous lesions.

Alternative Splicing ; genetics ; Cell Transformation, Neoplastic ; genetics ; pathology ; Cells, Cultured ; Gene Expression Regulation, Neoplastic ; physiology ; Humans ; Precancerous Conditions ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Telomerase ; classification ; genetics ; metabolism ; Telomere ; genetics

CD44 is a glycoprotein expressed in a wide variety of cell types. Recently expression of some alternatively-spliced variants of CD44 transcripts (CD44v) has been suggested to play a potential role in tumor metastasis and the detection of CD44v containing exon 6 to 11 may be helpful for the diagnosis of cancers. Expressions of CD44v containing exon 6 to 11 were investigated in 20 human colorectal cancer samples, peripheral blood leukocytes isolated from colorectal cancer patients, and 4 colorectal cancer cell lines using reverse transcription-polymerase chain reaction and Southern blot analysis. The standard form of CD44 transcripts was expressed in all samples tested. CD44v containing exon 6 to 11 was expressed in 18 cases of colorectal cancers (sensitivity = 90%), 3 out of 4 cell lines, and one normal tissue (specificity = 95%). These results suggest that the expression of CD44v containing exon 6 to 11 can be regarded as tumor specific and that this marker may be helpful for the early diagnosis of colon cancers, if specimens from the early stage are available.
Adenocarcinoma/*genetics ; Adult ; Aged ; Antigens, CD44/*genetics ; Base Sequence ; Blotting, Southern ; Colorectal Neoplasms/diagnosis/*genetics ; DNA Primers ; Electrophoresis, Agar Gel ; Feces/chemistry/cytology ; Female ; Gene Expression Regulation, Neoplastic/genetics ; Human ; Male ; Middle Age ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA Splicing/*physiology ; RNA, Messenger/analysis ; Tumor Cells, Cultured/*physiology ; Tumor Markers, Biological