PubMed Health⌕ Search

Biomedical subjects

Song-Qing Fan

Publications and source records attributed to Song-Qing Fan.

8 recordsLinked to original sources
PubMed2006

Gene expression profiling of nasopharyngeal carcinoma reveals the abnormally regulated Wnt signaling pathway.

Nasopharyngeal carcinoma (NPC) is a particularly common malignant disease in areas of south China and Southeast Asia. To characterize the gene expression profiling of NPC, we detected the gene expression profiles in 22 NPC and 10 nontumor nasopharyngeal epithelial tissues by complementary DNA microarray. We identified 503 genes that were significantly (P < .001) differentially regulated between NPC and nontumor nasopharyngeal epithelial tissues. The differentially expressed genes are involved in many signaling pathways, such as the Wnt, transforming growth factor-beta, and mitogen-activated protein kinase signaling pathways. The aberrant expression of the Wnt signaling pathway components, such as wingless-type MMTV integration site family, member 5A, Frizzled homolog 7, casein kinase IIbeta, beta-catenin, CREB-binding protein, and Dishevelled-associated activator of morphogenesis 2 was validated on the NPC tissue microarrays. The data suggest that the Wnt signaling pathway may be abnormally regulated in NPC, which provides insight into the molecular mechanisms of NPC.

Adolescent↗
PubMed2006

BRD2 is one of BRD7-interacting proteins and its over-expression could initiate apoptosis.

BRD7 is a potential nuclear transcription regulation factor related to nasopharyngeal carcinoma (NPC). BRD2, a putative BRD7-interacting protein, has been screened from human fetal brain cDNA library by yeast two-hybrid system. This study was to further identify the interaction between BRD7 and BRD2 in mammalian cells, and to investigate the subcellular localization of BRD2, as well as the effect on the functions of cell biology. Both immunoprecipitation and subcellular colocalization were performed together to identify the interaction of BRD7 with full-length BRD2, as well as C-terminal truncated BRD2 or N-terminal truncated BRD2. GFP direct fluorescence and Hochest 33258 staining were used to investigate the cellular localization pattern of BRD2 and the roles in initiating cell apoptosis in COS7 and HNE1. The results showed that BRD7 could interact with BRD2 and the region from amino acid 430 to 798 of BRD2 was critical for the interaction of BRD2 with BRD7. BRD2 mainly localizes in nucleus in two distribution patterns, diffused and dotted, and BRD2 has distinct roles in initiating apoptosis, and the dotted distribution pattern of BRD2 in nucleus may be a morphologic marker of cell apoptosis.

Animals↗
PubMed2006

Differential expression of Epstein-Barr virus-encoded RNA and several tumor-related genes in various types of nasopharyngeal epithelial lesions and nasopharyngeal carcinoma using tissue microarray analysis.

Studies have revealed that Epstein-Barr virus (EBV) infection, genetic aberration, and environmental factors are of importance in the development of nasopharyngeal carcinoma (NPC), although the definite mechanism remains to be fully elucidated. The aim of our study is to investigate using tissue microarray analysis whether differential expression of EBV-encoded small RNA-1 (EBER-1) and several tumor-related genes were associated with NPC carcinogenesis. Immunohistochemistry and in situ hybridization were performed on tissue microarrays containing 148 NPCs and 164 noncancerous nasopharyngeal epithelia (NPE) with different morphologic features. We found that overexpressions of EBER-1 hybridization signals, p53, p21ras, and bcl-2 proteins and loss expressions of p16 and p27 proteins were significantly increased in NPC tissues compared with normal NPE and hyperplastic NPE (P </= .001). The overexpressions of EBER-1 and p53 (P < .001) and the loss expressions of P16 (P < .001) and P27 (P = .005) were also significantly higher and more frequently observed in NPC than in dysplastic NPE. The positive expression of EBER-1 hybridization signals in NPC had significant associations with overexpressions of p53 (P < .001), p21ras (P = .041), and bcl-2 proteins (P < .001) and loss expression of p16 protein (P = .001). Further analysis confirmed that the abnormal expression of p53, p16, and p27 proteins occurred in the earliest stage of nasopharyngeal epithelial carcinogenesis. In the final logistic regression analysis model, the positive hybridization signals of EBER-1 and the abnormal expression of p53, p16, and p27 proteins were independent contributions for nasopharyngeal carcinogenesis, and EBER-1 was the most significant, independent predictor of nasopharyngeal carcinogenesis (hazard ratio = 13.412, 95% confidence interval 6.179-29.111, P < .001). In conclusion, EBV infection, together with overexpressions of p53, and loss expressions of p16 and p27 proteins are involved in the multistep process of human nasopharyngeal epithelial carcinogenesis.

Adenocarcinoma↗
PubMed2003

[In situ expression of connexins in various carcinomas].

BACKGROUND & OBJECTIVE: Malignant cells are often associated with aberrant expression or localization of connexins. Expression of Cx26, Cx32, Cx43, and Cx45 genes were studied to gain their expression profile in tissue microarrayers consisting of various carcinomas and to elucidate their function in carcinogenesis. METHODS: Basing on the principle of constructing tissue microarrays, the authors take use of self-made tissue arrayer to construct tissue microarrays for the different kinds of cancer specimens. Meanwhile, expression of connexin(Cx) genes, such as Cx32, Cx26, Cx43, and Cx45 in the tissue microarrays were detected in 292 cases of tumor tissues and 89 paratumor tissues by immunohistochemistry. RESULTS: (1) Three kinds of tissue microarrays consisting samples from 20 different carcinomas were constructed successfully, which contained 360, 200, or 100 spots in each receptive paraffin block with tissue cylinder of 0.75mm or 0.6mm diameter respectively.(2) The expression profiles of Cx32, Cx26, Cx43, and Cx45 in 20 kinds of carcinomas and their related adjacent-cancer tissues were gained, which were widely low expressed in carcinomas especially in nasopharyngeal carcinomas. Expression of Cx26, Cx32, Cx43, and Cx45 in carcinomas such as carcinomas of colon and recta, hepatocellular carcinomas, gastric carcinomas, lung carcinomas and thyroid cancers were significantly lower than their related adjacent-cancer tissues. CONCLUSION: Low expression of Cx26, Cx32, Cx43, and Cx45 might play crucial roles in carcinogenesis of many kinds of carcinomas. Tissue microarrays consisting of many different kinds of carcinomas provide a new high-throughout tool for rapid and comprehensive molecular expression profiles of carcinomas, such as connexin genes.

Carcinoma↗
PubMed2003

Expression of LRRC4 has the potential to decrease the growth rate and tumorigenesis of glioblastoma cell line U251.

BACKGROUND & OBJECTIVE: LRRC4 is a novel gene that the author has identified recently, which displayed significant downregulation in primary brain tumor biopsies. This study was designed to investigate if LRRC4 has the potential of suppressing brain tumor growth. METHODS: The full-length coding region of LRRC4 gene was subcloned into the expression vector pcDNA3.1, the recombinant was introduced into the glioblastoma cell line U251 by liposome transfection, and the U251 cells stably expressing LRRC4 gene were established by G418 selection. Furthermore, cell proliferation assay, soft agar assay, tumorigenesis assay were taken to examine the effect of LRRC4 expression on cell growth and tumor formation. RESULTS: U251 cells stably expressing full-length coding region of LRRC4 were established by lipofection-mediated transfection and selected for further study. Compared with the nontransfected and vector-transfected cells, the cells transfected with LRRC4 cDNA exhibited a significant increase of expression of LRRC4 mRNA by Northern blot analysis. Further, when cell proliferation was followed over several days, the cells expressing the transfected LRRC4 cDNA grew more slowly than nontransfected cells. Consistently, the cells transfected with LRRC4 exhibited markedly lower colony formation rate. These clones were injected into athymic nude mice who was killed after 40 days and the tumor sizes were evaluated. Tumor volume in mice was significantly smaller in the group of cells stably transfected with LRRC4 cDNA than in the control. CONCLUSION: LRRC4 gene may be transfected into the human glioblastoma cell line U251. The expression of LRRC4 in U251 cells may have the potential to suppress tumor cell growth and the tumorigenesis of U251 cell transplanted in nude mice.

Animals↗
PubMed2003

[Expression and clinical significance of MMP-2, MMP-9,TIMP-1, and TIMP-2 in breast carcinoma].

BACKGROUND & OBJECTIVE: Expression imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play pivotal roles in tumor invasion and metastasis. But little is known about the correlation between their expression and breast cancer prognosis. The aim of this study was to investigate the expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 in breast carcinomas and to seek their relationship with breast cancer invasion, metastasis, and prognosis. METHODS: Sixty-six patients of breast cancer with clinical features and survival data were enrolled. The mRNA expression of TIMP-2, MMP-2 were determined using in situ hybridization. The protein expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined using immunohistochemistry. The results were analyzed using chi-square test, Kaplan-Meier method, and Cox multivariate regression analysis. RESULTS: The positive expression rates of TIMP-2 mRNA, MMP-2 mRNA and MMP-2, MMP-9, TIMP-1, and TIMP-2 protein were 66.7% (44/66), 65.2% (43/66) and 71.2% (47/66), 68.2% (45/66), 40.9% (27/66), 69.7% (46/66), respectively. The expression of MMP-2 protein had positive correlation with those of MMP-2 mRNA and MMP-9 protein(P< 0.01). The expression of TIMP-2 mRNA had positive correlation with that of TIMP-2 protein. Negative correlation between expression of TIMP-1 protein and MMP-9 protein was found (P< 0.01). Overexpression of MMP-2 and MMP-9 protein were higher in breast cancers with lymph node metastases than those without lymph node metastases, whereas TIMP-2 mRNA and TIMP-1 protein expression were lower in breast cancers with lymph node metastases than those without lymph node metastases (P< 0.05). MMP-2 mRNA and MMP-9 protein were positively associated with the tumor size and shortened survival time(P< 0.05, P< 0.01). Increased expression of MMP-9 protein was correlated with high TNM classification(P< 0.01). The patients of menopause and ER negative expression had higher expression of MMP-2 mRNA (P< 0.05). Kaplan-Meier analysis showed that MMP-2 mRNA, MMP-2 and MMP-9 proteins were linked with unfavorable prognosis(P< 0.01,P< 0.05). CONCLUSION: Overexpression of MMP-2, MMP-9 and expression imbalance between MMP-9 and TIMP-1 protein might play critical roles in degradation of extracellular matrix to enhance the invasive and metastatic capacity of breast cancer. MMP-2 protein might be applied as an independent prognostic indicator for primary breast cancer.

Adult↗
PubMed2003

[Information behavior of 7 STR loci on chromosome 9p in gene scanning].

To get genotype and allele frequency distributions of seven short tandem repeat (STR) loci of chromosome 9p,D9S288,D9S157,D9S1748,D9S171,D9S161,D9S1817 and D9S1805 in Chinese Han population in Hunan area,blood samples were collected from the random Han individual in Hunan and the whole genomic DNA was extracted.STR loci were amplified by multiplex-PCR technique and genotyped by ABI 377 sequencer.Seventy-five alleles were detected,with frequencies ranging from 0.002 to 0.800,and constituted 243 genotypes. All the seven loci met Hardy-Weinberg equilibrium. The statistical analysis of seven STR loci showed H(heterozygosity) ranging from 0.347 to 0.844,DP(discrimination power) ranging from 0.346 to 0.841,PPE(probabilities of paternity exclusion) ranging from 0.308 to 0.738 and PIC(polymorphic information content) ranging from 0.328 to 0.822. The result indicated that there was a significant difference between Han ethnic group and the white and the black.

English Abstract↗