类mRNA RNA研究进展

类 m RNA RNA (m RNA- like RNA)是一类 3′端有 Poly A ,无典型 ORF,不编码蛋白质 ,而直接在 RNA水平上发挥作用的 RNA分子。近年来的研究表明各种不同的类 m RNA RNA广泛存在于不同的细胞内 ,并发挥着重要的调控作用。它们与细胞的生长和分化、胚胎的发育。

Expression and significance of CD44s, CD44v6, and nm23 mRNA in human cancer

AIM: To investigate the relationship between the expression levels of nm23 mRNA, CD44s, and CD44v6,and oncogenesis, development and metastasis of human gastric adenocarcinoma, colorectal adenocarcinoma,intraductal carcinoma of breast, and lung cancer.METHODS: Using tissue microarray by immuhistochemical (IHC) staining and in situ hybri-dization (ISH), we examined the expression levels of nm23mRNA, CD44s, and CD44v6 in 62 specimens of human gastric adenocarcinoma and 62 specimens of colorectal adenocarcinoma; the expression of CD44s and CD44v6in 120 specimens of intraductal carcinoma of breast and 20 specimens of normal breast tissue; the expression of nm23 mRNA in 72 specimens of human lung cancer and 23 specimens of normal tissue adjacent to cancer.RESULTS: The expression of nm23 mRNA in the tissues of gastric and colorectal adenocarcinoma was not significantly different from that in the normal tissues adjacent to cancer (P＞0.05), and was not associated with the invasion of tumor and the pathology grade of adenocarcinoma (P＞0.05). However, the expression of nm23 mRNA was correlated negatively to the lymph node metastasis of gastric and colorectal adenocarcinoma (r = -0.49, P＜0.01; r = -4.93, P＜0.01). The expression of CD44s in the tissues of gastric and colorectal adenocarcinoma was significantly different from that in the normal tissues adjacent to cancer (P＜0.05;P＜0.01). CD44v6 was expressed in the tissues of gastric and colorectal adenocarcinoma only, the expression of CD44v6 was significantly associated with the lymph node metastasis, invasion and pathological grade of the tumor (r = 0.47, P＜0.01; r = 5.04, P＜0.01). CD44sand CD44v6 were expressed in intraductal carcinoma of breast, the expression of CD44s and CD44v6 was significantly associated with lymph node metastases and invasion (P＜0.01). However, neither of them was expressed in the normal breast tissue. In addition, the expression of CD44v6 was closely related to the degree of cell differentiation of intraductal carcinoma of breast (x2= 5.68, P＜0.05). The expressional level of nm23mRNA was closely related to the degree of cell differentiation (P＜0.05) and lymph node metastasis (P＜0.01), but the expression of nm23 gene was not related to sex, age, and type of histological classification (P＞0.05).CONCLUSION: Patients with overexpression of CD44s and CD44v6 and low expression of nm23 mRNA have a higher lymph node metastatic rate and invasion. In addition, overexpression of CD44v6 is closely related to the degree of cell differentiation. Detection of the three genes is able to provide a reliable index to evaluate the invasion and metastasis of tumor cells.

mRNA differential display on gene expression in settlement metamorphosis process of Ruditapes philippinarum larvae

The mRNA differential display (DDRT-PCR) technique was adopted to find out the genes related tosettlement metamorphosis development process of Ruditapes philippinarum larvae.In this study,we haveobtained three hundred and forty-six amplification bands in total from pediveliger larvae,veliger larvae,eye spot larvae and post-larvae.Sixty-five out of three hundred and forty-six bands are distinctly differen-tial display from band pattern,which can be put into four groups,standing for different expression char-acters.Sixteen differential display bands were cloned,sequenced and analyzed and nine different se-quences are obtained in the study.Three sequences have higher similarity to the cDNAs deposited indatabase and three are very similar to the rDNA of other species,considered as the rDNA of Ruditapesphilippinarum.The rest three sequences are found to be novel sequences after analyzed.Their accessionnumbers are AY916799,AY916798,and AY916797 respectively.We thought the novel sequences arepossibly relevant to the early embryo development of Ruditapes philippinarum larvae and can provide somefundamental understandings that are helpful for the improvement of scallop seed raising industry.

A Second Protein Marker of Caveolae:Caveolin-2

Caveolin-2,a protein about 20 kD,is a major component of the inner surface of caveolae,small invaginations of the plasma membrane.Similar with caveolin-1 and caveolin-3,it serves as a protein marker of caveolae.Caveolin-1 and-2 are located next to each other at 7q31.1 on human chromosome,the proteins encoded are co-localized and form a stable hetero-oligomeric complex,distributing similarly in tissue and cultured cells.Caveolin-3 is located on different chromosomes but confirmed to interact with caveolin-2.Caveolin-2 is similar to caveolin-1 in many respects but differs from the latter in functional domains,especially in G-protein binding domain and caveolin scaffolding domain.The mRNAs of both caveolin-1 and caveolin-2 are most abundantly expressed in white adipose tissue and are induced during differentiation of 3T3-L1 cells to adipocytes.Caveolin-2-deficinet mice demonstrate clear pulmonary defects,with little or no change in caveolin-1 expression and caveolae formation,suggesting that caveolin-2 plays a selective role in lung functions.Caveolin-2 is also involved in lipid metabolism and human cancers.

Correlation between the expression of vascular endothelial growth factor c and C-erbB-2 in human breast cancer

Objective: We aimed to study the transcription level of VEGF-C in human breast cancer tissue, and explore the correlations with the expression of C-erbB-2. Methods: The expression of VEGF-C mRNA in 51 cases of human breast cancer was assessed by hybridization in situ. The expressions of C-erbB-2 was assessed by immunohistochemistry. Results: The positive rate of VEGF-C mRNA was 54.9% in 51 cases of breast cancer. The transcription level had correlation with tumor size and status of lymph nodes(P < 0.05). The expression of VEGF-C mRNA had a positive correlation with the expression of C-erbB-2(P < 0.05). Conclusion: The up-expression of VEGF-C has a significant correlation with the malignancy level and clinical stage of breast cancer. The combined detection of VEGF-C, C-erbB-2 may help to estimate the prognosis of patients with breast cancer and study on thetherapeutic implications.

Gradient decrease in telomerase and its RNA in progressive passage of human endometrial stromal stem cells

The purpose of this study was to explore the change of telomerase in passage from human endometrial stromal stem cells isolated from human endometrium.Telomerase activity of cultured endometrial stromal cells was assessed at mRNA and protein levels using RT-PCR and immunohistochemistry technique.Telomerase mRNA and protein levels were higher at early passages,and then had a gradually decreased trend of immunoreactive intensity and gradually weakened positive cells with progressive passage in endometrial stromal stem cells.These results suggest that telomerase is contributed to the insenecence of endometrial stem cell.

极快速减压后大鼠肺组织磷酯酶A2mRNA表达的改变

目的研究极快速减压对大鼠肺组织ⅡA类磷酯酶A2（sPLA2）mRNA表达的影响。方法极快速减压处理后0～210min，间隔30min，分8个时间点对大鼠肺组织ⅡA类sPLA2mRNA表达水平进行连续检测，同时进行每个时间点的肺组织病理学特征和肺湿干重比检测。结果极快速减压处理后30min，大鼠肺组织ⅡA类sPLA2mRNA有一个表达高峰；大鼠肺组织病理损伤特征经历了一个由重至轻，再逐渐加重的反复变化过程；肺湿干重比有一个从重到轻的变化过程。结论大鼠经极快速减压处理出舱后210min内，肺损伤程度经历了一个由重到轻，然后再加重的过程；极快速减压能够导致大鼠肺组织ⅡA类sPLA2mRNA表达水平由低到高，然后再降低，其具体机制有待进一步研究。

RNA-binding proteins in neurological diseases

Emerging studies support that RNA-binding proteins （RBPs） play critical roles in human biology and pathogenesis. RBPs are essential players in RNA processing and metabolism, including pre-mRNA splicing, polyadenylation, transport, surveillance, mRNA localization, mRNA stability control, translational control and editing of various types of RNAs. Aberrant expression of and mutations in RBP genes affect various steps of RNA processing, altering target gene function. RBPs have been associ- ated with various diseases, including neurological diseases. Here, we mainly focus on selected RNA-binding proteins including Nova-i/Nova-2, HuR/HuB/HuC/HuD, TDP-43, Fus, Rbfoxl/Rbfox2, QKI and FMRP, discussing their function and roles in human diseases.

Uridylation and adenylation of RNAs

The posttranscriptional addition of nontemplated nucleotides to the 3′ ends of RNA molecules can have a significant impact on their stability and biological function. It has been recently discovered that nontemplated addition of uridine or adenosine to the 3′ ends of RNAs occurs in different organisms ranging from algae to humans, and on different kinds of RNAs, such as histone m RNAs, m RNA fragments, U6 sn RNA, mature small RNAs and their precursors etc. These modifications may lead to different outcomes, such as increasing RNA decay, promoting or inhibiting RNA processing, or changing RNA activity. Growing pieces of evidence have revealed that such modifications can be RNA sequence-specific and subjected to temporal or spatial regulation in development. RNA tailing and its outcomes have been associated with human diseases such as cancer. Here, we review recent developments in RNA uridylation and adenylation and discuss the future prospects in this research area.

切割与多聚腺苷酸化特异因子与肿瘤相关研究进展

在人类实体肿瘤中,首选治疗方法是手术切除,但多数临床确诊的肿瘤患者已处于中晚期,失去了手术机会.切割与多聚腺苷酸化特异因子是参与mRNA 3＇端的切割和多聚腺嘌呤poly （A）尾的添加,在mRNA成熟和细胞信号转导过程中扮演着重要的角色.在某些条件下,切割与多聚腺苷酸化特异因子表达的异常能导致癌基因的激活,进而引起肿瘤的发生.本文就切割与多聚腺苷酸化特异因子与肿瘤相关研究进行综述.

The conserved ubiquitin-like protein Hub1 plays a critical role in splicing in human cells

Different from canonical ubiquitin-like proteins, Hub1 does not form covalent conjugates with substrates but binds proteins noncovalently. In Socchoromyces cerevisioe, Hub1 associates with spUceosomes and mediates alternative splicing of SRCI, without affecting pre-mRNA splicing generaity. Human Hub1 is highty similar to its yeast homotog, but its cellular function remains largely unexplored. Here, we show that human Hub1 binds to the spliceosomal protein Snu66 as in yeast; however, unlike its 5. cerevisioe homolos, human Hub1 is essential for viability. Prolonged in vivo depletion of human Hub1 leads to various cellular defects, including splicing speckle abnormalities, partial nuclear retention of mRNAs, mitotic catastrophe, and consequently cell death by apoptosis. Early consequences of Hub1 depletion are severe splicing defects, however, only for specific splice sites leading to exon skipping and intron retention. Thus, the ubiquitin-iike protein Hub1 is not a canonlcal spliceosomal factor needed generally for splicing, but rather a modulator of spliceosome performance and facilitator of alternative splicing.