Precursor messenger RNA (pre-mRNA) splicing is catalyzed by an intricate ribonucleoprotein complex called the spliceosome. Although the spliceosome is considered to be general cell "housekeeping" machinery, mutations in core components of the spliceosome frequently correlate with cell- or tissue-specific phenotypes and diseases. In this review, we expound the links between spliceosome mutations, aberrant splicing, and human cancers. Remarkably, spliceosome-targeted therapies (STTs) have become efficient anti-cancer strategies for cancer patients with splicing defects. We also highlight the links between spliceosome and immune signaling. Recent studies have shown that some spliceosome gene mutations can result in immune dysregulation and notable phenotypes due to mis-splicing of immune-related genes. Furthermore, several core spliceosome components harbor splicing-independent immune functions within the cell, expanding the functional repertoire of these diverse proteins.
Humans ; Neoplasms/metabolism* ; RNA Precursors/metabolism* ; RNA Splicing ; RNA Splicing Factors/metabolism* ; Spliceosomes/metabolism*

Alternative splicing of pre-mRNA is an important mechanism for regulating gene function at the post-transcription level and for producing proteomic diversity in higher eukaryotes. The alternative splicing is regulated by the interaction between diverse cis-acting elements and trans-acting factors. Alternative splicing events of oncogenes, tumor suppressor genes and metastasis suppressor genes are associated with the initiation and development of human neoplasms. The protein isoforms sourced from alternative splicing take part in regulating the gene transcription, cell cycle, apoptosis of cells, and playing a role in tumor growth. It is possible for molecular therapy to target directly isoforms of protein produced by alternative splicing or to interfere with the process of alternative splicing.
Alternative Splicing ; genetics ; Humans ; Neoplasms ; genetics ; RNA Precursors ; metabolism ; RNA, Neoplasm ; analysis ; Transcription, Genetic

Varying length of messenger RNA (mRNA) 3′-untranslated region is generated by alternating the usage of polyadenylation sites during pre-mRNA processing. It is prevalent through all eukaryotes and has emerged as a key mechanism for controlling gene expression. Alternative polyadenylation (APA) plays an important role for cell growth, proliferation, and differentiation. In this review, we discuss the functions of APA related with various physiological conditions including cellular metabolism, mRNA processing, and protein diversity in a variety of disease models. We also discuss the molecular mechanisms underlying APA regulation, such as variations in the concentration of mRNA processing factors and RNA-binding proteins, as well as global transcriptome changes under cellular signaling pathway.
Eukaryota ; Gene Expression ; Humans* ; Metabolism ; Polyadenylation* ; RNA Precursors ; RNA, Messenger ; RNA-Binding Proteins ; TOR Serine-Threonine Kinases ; Transcriptome

MicroRNAs (miRNAs) are conserved small non-coding RNAs that play an important role in the regulation of gene expression and participate in a variety of biological processes. The biogenesis of miRNAs is tightly controlled at multiple steps, such as transcription of miRNA genes, processing by Drosha and Dicer, and transportation of precursor miRNAs (pre-miRNAs) from the nucleus to the cytoplasm by exportin-5 (XPO5). Given the critical role of nuclear export of pre-miRNAs in miRNA biogenesis, any alterations of XPO5, resulting from either genetic mutation, epigenetic change, abnormal expression level or posttranslational modification, could affect miRNA expression and thus have profound effects on tumorigenesis. Importantly, XPO5 phosphorylation by ERK kinase and its cis/trans isomerization by the prolyl isomerase Pin1 impair XPO5's nucleo-to-cytoplasmic transport ability of pre-miRNAs, leading to downregulation of mature miRNAs in hepatocellular carcinoma. In this review, we focus on how XPO5 transports pre-miRNAs in the cells and summarize the dysregulation of XPO5 in human tumors.
Carcinoma, Hepatocellular ; genetics ; metabolism ; Cell Nucleus ; metabolism ; Cytoplasm ; metabolism ; Humans ; Karyopherins ; chemistry ; metabolism ; physiology ; Liver Neoplasms ; genetics ; metabolism ; MicroRNAs ; chemistry ; metabolism ; NIMA-Interacting Peptidylprolyl Isomerase ; Neoplasms ; genetics ; metabolism ; RNA Precursors ; chemistry ; metabolism ; RNA Transport

Spliceosomal RNAs are a family of small nuclear RNAs (snRNAs) that are essential for pre-mRNA splicing. All vertebrate spliceosomal snRNAs are extensively pseudouridylated after transcription. Pseudouridines in spliceosomal snRNAs are generally clustered in regions that are functionally important during splicing. Many of these modified nucleotides are conserved across species lines. Recent studies have demonstrated that spliceosomal snRNA pseudouridylation is catalyzed by two different mechanisms: an RNA-dependent mechanism and an RNA-independent mechanism. The functions of the pseudouridines in spliceosomal snRNAs (U2 snRNA in particular) have also been extensively studied. Experimental data indicate that virtually all pseudouridines in U2 snRNA are functionally important. Besides the currently known pseudouridines (constitutive modifications), recent work has also indicated that pseudouridylation can be induced at novel positions under stress conditions, thus strongly suggesting that pseudouridylation is also a regulatory modification.
Animals ; Base Sequence ; Molecular Sequence Data ; Nucleic Acid Conformation ; Nucleotides ; metabolism ; Oocytes ; cytology ; metabolism ; Pseudouridine ; metabolism ; RNA Precursors ; metabolism ; RNA Splice Sites ; RNA Splicing ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Nuclear ; genetics ; metabolism ; Ribonucleoproteins, Small Nuclear ; genetics ; metabolism ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; genetics ; metabolism ; Spliceosomes ; genetics ; metabolism ; Uridine ; analogs & derivatives ; metabolism ; Xenopus ; genetics ; metabolism

Spinal muscular atrophy(SMA) is a genetic disorder of the motor neurons that cause muscular weakness and muscular atrophy due to anterior horn cell degeneration. Classic spinal muscular atrophy patient is caused by mutation in the chromosome 5(q11.2-q13.3), and the majority of the patient shows homozygous deletion of the telomeric survival motor neuron(SMN) gene in the chromosome 5. Deletion of exon 7 and 8 of the SMN gene and deletion of exon 4 and 5 of the neuronal apoptosis inhibitory protein(NAIP) are typically observed in SMA patients. The SMN protein plays a role in an essential cell metabolism process, the splicing of pre mRNA in the spliceosomes. We report a 7 month old male with SMA. He showed rapidly aggrdvatial muscular weakness and died at 7 months. His DNA analysis proved deletion of exon 7 and 8 of the telomeric copy of the SMN gene.
Anterior Horn Cells ; Apoptosis ; Chromosomes, Human, Pair 5 ; DNA ; Exons* ; Humans ; Infant ; Male ; Metabolism ; Motor Neurons* ; Muscle Weakness ; Muscular Atrophy ; Muscular Atrophy, Spinal* ; Neurons ; RNA Precursors ; Spliceosomes

OBJECTIVETo explore the central mechanism of moxibustion on analgesic effect.

METHODSMale Wistar rats were screened by pain threshold value before making model, and 48 rats whose pain threshold was (250 +/- 25) g were selected. Twelve male Wistar rats were randomly selected as a normal group. For the rest rats the rheumatoid arthritis (RA) model was duplicated by raising in a windy, cold and wet environment combined with injection of Freund's complete adjuvant (FCA), and then they were randomly divided into a model group, a moxibustion group and a moxa volatile oil group, 12 rats in each group. The moxibustion and the moxa volatile oil igroup were treated with moxibustion and moxa volatile oil at "Shenshu"(BL 23) and "Zusanli"(ST 36), respectively, for 15 days. No interventions were added on the model group and the normal group. The pain threshold in Iinjured foot and the expression of hypothalamic POMC mRNA and PDYN mRNA in rats were observed.

RESULTSCompared with the normal group, the pain threshold and the expression of hypothalamic POMC mRNA and PDYN mRNA in the model group were increased (all P < 0.01). Compared with the model group, the pain threshold and the expression of hypothalamic POMC mRNA and PDYN mRNA in the moxibustion group were increased significantly (all P < 0.01), but no statistically significance in the moxa volatile oil group (P > 0.05). Compared with the moxa volatile oil group, the above-mentioned observative indices in moxibustion group were all increased significantly (all P < 0.01).

CONCLUSIONMoxibustion has obvious analgesic effect and its mechanism may be related to the increasing expression of hypothalamic POMC and PDYN mRNA through the warming effect of moxibustion.

Animals ; Arthritis, Rheumatoid ; genetics ; metabolism ; therapy ; Enkephalins ; genetics ; metabolism ; Humans ; Hypothalamus ; metabolism ; Male ; Moxibustion ; Pro-Opiomelanocortin ; genetics ; metabolism ; Protein Precursors ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo establish a quantitative method to detect circulating tumor cells (CTC) in patients with small cell lung cancer, and analyze its sensitivity and stability.

METHODSA specific primer and probe for prepro-gastrin-releasing peptide (preproGRP) was designed and a quantitative RT-PCR method was established to detect preproGRP mRNA. Cell incorporation method was used to evaluate the sensitivity. Magnetic cell sorting (MACS) was used to isolate and purify CTC from peripheral blood, and the MACS in combination with morphological diagnosis were used for cell counting.

RESULTSThe isolation rate of CTC by MACS was 30% and the lower detection limit was 5 cells per ml blood. The sensitivity of quantitative RT-PCR in detection of preproGRP mRNA in CTC was 0.64 cells per reaction, and the lower detection limit was 50 cells per ml blood, which was lower than that of MACS. However, the cell numbers calculated by Ct value was in greater accordance (about 80%) with actual cell numbers than that obtained by MACS.

CONCLUSIONSPreproGRP quantitative RT-PCR and MACS have both advantages and disadvantages in detecting CTC of SCLC patients. MACS has a higher sensitivity, and is more favorable when CTC count is below 50 per ml blood. Meanwhile, preproGRP mRNA quantitative RT-PCR is more reliable in calculating actual cell numbers.

Humans ; Immunomagnetic Separation ; Lung Neoplasms ; blood ; metabolism ; pathology ; Neoplastic Cells, Circulating ; Peptides ; genetics ; metabolism ; Protein Precursors ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Small Cell Lung Carcinoma ; blood ; metabolism ; pathology

OBJECTIVETo investigate the expression of motilin and its precursor mRNA in normal human thyroid. To compare the expression differences of motilin and it precursor mRNA between normal thyroid and intestines. To study the expression of motilin and its precursor mRNA in human thyroid tumors and their clinical implications.

METHODSRT-PCR, Southern blot and molecular cloning were used to detect motilin transcript expression in human thyroid and mucous membrane of small intestine. Real-time PCR and immunohistochemical techniques were used to quantify motilin precursor mRNA and motilin peptide in thyroid tissue samples including adenoma, medullary carcinoma, follicular carcinoma, papillary carcinoma and nodular goiter.

RESULTS(1) The expression of motilin and its precursor mRNA in normal human thyroid was primarily in the thyroid C cells. (2) RT-PCR and Southern blot showed that motilin mRNA expressed in human thyroid was identical to that expressed in duodenum with identical sequence deposited in NCBI Genbank of America. (3) Immunohistochemistry, Western blot research and real-time PCR studies showed that motilin and its precursor mRNA were expressed in normal and tumor tissues of human thyroid. Thyroid tumors (acidophilic adenoma, medullary carcinoma, follicular carcinoma, papillary carcinoma and nodular goiter) showed intense and diffuse immunostaining for motilin peptide. Moreover, the expression of motilin and its precursor mRNA in thyroid medullar carcinoma and acidophilic adenoma were significantly higher than those of normal thyroid tissue (P < 0.05). The expression in thyroid follicular and papillary carcinomas were significantly lower than those of normal thyroid tissue (P < 0.05). There was no difference of the expression between nodular goiter and normal thyroid tissue (P > 0.05).

CONCLUSIONSMotilin peptide and its precursor mRNA are expressed in C cells of human thyroid. The sequence of motilin is identical to that expressed in duodenum from NCBI Genbank of America. The expressions of both motilin and its precursor mRNA in thyroid medullary carcinoma and acidophilic adenoma are significantly increased. In contrast, their expressions in thyroid follicular and papillary carcinomas are significantly decreased. Motilin may regulate physiological functions of the thyroid through parafollicular cells. Motilin may be involved in the pathogenesis of medullary carcinoma and acidophilic adenoma of the thyroid.

Adenocarcinoma, Follicular ; genetics ; Adult ; Aged ; Biomarkers, Tumor ; metabolism ; Carcinoma, Medullary ; genetics ; Carcinoma, Papillary ; genetics ; metabolism ; Female ; Humans ; Intestines ; metabolism ; Male ; Middle Aged ; Motilin ; genetics ; metabolism ; Nervous System Neoplasms ; metabolism ; RNA Precursors ; metabolism ; RNA, Messenger ; metabolism ; Thyroid Gland ; metabolism ; Thyroid Neoplasms ; genetics ; metabolism

OBJECTIVETo examine the changes of expressions of orexin A, orexin receptor-1 (OX1R), prepro-orexin (Prepro-OX) mRNA, OX1R mRNA and ob-R of hypothalamus in rats with chronic renal failure (CRF).

METHODSSixty-two male Wister rats weighing 200-250 g were divided into three groups, including group 1 (normal, n = 5), group 2 (sham-operated, n = 25) and group 3 (CRF, n = 32). Hypothalamus orexin A was assayed by radioimmunoassay. Serum leptin was assayed by enzyme linked immunosorbent assay. The expression of Prepro-OX mRNA and OX1R mRNA of hypothalamus were measured by reverse transcription polymerase chain reaction, and expression of orexin A, OX1R and ob-R by immunohistochemistry. Automatic biochemical analyzer was used to measure the serum creatinine.

RESULTSHypothalamus orexin A levels were negatively correlated (r = -0.63, P < 0.001) with serum leptin levels in the rats. The expression of hypothalamus Prepro-OX mRNA in CRF rats was significantly lower than that of sham-operation at week 12 (P < 0.01). Hypothalamus Prepro-OX mRNA levels were negatively correlated (r = -0.81, P < 0.001) with the levels of serum leptin and serum creatinine (r = -0.68, P < 0.05) in the rats at week 12. The expression of hypothalamus OX1R mRNA in CRF rats was lower than that of sham-operation at week 12 (P > 0.05). Specific immunoreactivity for orexin A was present in perikeryon of the hypothalamus neuron. Specific OX1R-like immunoreactivity was observed in some nerve fibres. Specific immunoreactivity for ob-R was present in membranes of the hypothalamus neuron. Hypothalamus neurons of orexin A-like specific immunoreactivity in CRF rats were significantly fewer than those in shamoperated rats at week 8. Hypothalamus neurons of OX1R-like specific immunoreactivity in CRF rats were similar to those in sham-operated rat at week 8. Hypothalamus neurons of ob-R-like specific immunoreactivity in CRF rats were significantly more than those in sham-operated rats at week 8.

CONCLUSIONSThe lower hypothalamus orexin A levels may be induced by high serum leptin level in CRF rats. The lower expression of hypothalamus Prepro-OX mRNA in CRF rats may be one of the main causes inducing lower hypothalamus orexin A. The expression of OX1R in hypothalamus neurons is somewhat reduced and the expression of ob-R in hypothalamus neurons is somewhat raised in CRF rats. These remain to be studied further.

Animals ; Carrier Proteins ; genetics ; metabolism ; Hypothalamus ; metabolism ; Intracellular Signaling Peptides and Proteins ; Kidney Failure, Chronic ; metabolism ; Leptin ; genetics ; metabolism ; Male ; Neuropeptides ; genetics ; metabolism ; Neurotransmitter Agents ; genetics ; metabolism ; Orexin Receptors ; Orexins ; Protein Precursors ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Cell Surface ; genetics ; metabolism ; Receptors, G-Protein-Coupled ; Receptors, Leptin ; Receptors, Neuropeptide ; genetics ; metabolism