A miRNA-HERC4 pathway promotes breast tumorigenesis by inactivating tumor suppressor LATS1

The E3 ligase HERC4 is overexpressed in human breast cancer and its expression levels correlated with the prognosis of breast cancer patients. However, the roles of HERC4 in mammary tumorigenesis remain unclear. Here we demonstrate that the knockdown of HERC4 in human breast cancer cells dramatically suppressed their proliferation, survival, migration, and tumor growth in vivo, while the overexpression of HERC4 promoted their aggressive tumorigenic activities. HERC4 is a new E3 ligase for the tumor suppressor LATS1 and destabilizes LATS1 by promoting the ubiquitination of LATS1. miRNA-136-5p and miRNA-1285-5p, expression of which is decreased in human breast cancers and is inversely correlated with the prognosis of breast cancer patients, are directly involved in suppressing the expression of HERC4. In summary, we discover a miRNA-HERC4-LATS1 pathway that plays important roles in the pathogenesis of breast cancer and represents new therapeutic targets for human breast cancer.

Core pluripotency factors promote glycolysis of human embryonic stem cells by activating GLUT1 enhancer

Human embryonic stem cells (hESCs) depend on glycolysis for energy and substrates for biosynthesis. To understand the mechanisms governing the metabolism of hESCs, we investigated the transcriptional regulation of glucose transporter 1 (GLUT1, SLC2A1), a key glycolytic gene to maintain pluripotency. By combining the genome-wide data of binding sites of the core pluripotency factors (SOX2, OCT4, NANOG, denoted SON), chromosomal interaction and histone modification in hESCs, we identified a potential enhancer of the GLUT1 gene in hESCs, denoted GLUT1 enhancer (GE) element. GE interacts with the promoter of GLUT1, and the deletion of GE significantly reduces the expression of GLUT1, glucose uptake and glycolysis of hESCs, confirming that GE is an enhancer of GLUT1 in hESCs. In addition, the mutation of SON binding motifs within GE reduced the expression of GLUT1 as well as the interaction between GE and GLUT1 promoter, indicating that the binding of SON to GE is important for its activity. Therefore, SON promotes glucose uptake and glycolysis in hESCs by inducing GLUT1 expression through directly activating the enhancer of GLUT1.

Generation of a new strain of NOD/SCID/IL2Rγ mice with targeted disruption of Prkdc and IL2Rγ genes using CRISPR/Cas9 system / 南方医科大学学报

<p><b>OBJECTIVE</b>The NOD/SCID/IL2Rγ (NSG) mouse strain is the most widely used immunodeficient strain for xenograft transplantation. However, the existing SCID mutation is a spontaneous mutation of the Prkdc gene, which leads to leaky T cell developmental block and difficulty in genotyping. It is therefore important to develop a new strain of NSG mice with targeted disruption of Prkdc and IL2Rγ genes.</p><p><b>METHODS</b>Targeted disruption of Prkdc and IL2Rγ genes was achieved using the CRISPR/Cas9 system. By intercrossing the knockout and NOD mice, we obtained a novel strain of NOD/SCID/IL2Rγ(NSG) mice, denoted as cNSG (Chinese NSG) mice.</p><p><b>RESULTS</b>In addition to the NOD mutation, cNSG mice exhibited a complete absence of T cells, B cells and NK cells. cNSG mice allowed more efficient engraftment of human cancer cells than the commonly used immunodeficient nude mice.</p><p><b>CONCLUSION</b>cNSG mice will provide an important xenotransplantation model for biomedical research.</p>

Expressions of short palate, lung and nasal epithelium clone 1 in different human tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the expression patterns of short palate, lung and nasal epithelium clone 1 (SPLUNC1) gene in human tissues.</p><p><b>METHODS</b>In situ hybridization was used to detect the expression of SPLUNC1 gene in 37 different human tissues.</p><p><b>RESULTS</b>We found that SPLUNC1 gene was not expressed in squamous epithelial cells of the palate, epidermis, esophagus, or the esophagus-cardia junction, metaplastic squamous cells in the nasopharynx, trachea, or uterus cervix, or tumor cells of esophageal squamous cell carcinoma or lung squamous cell carcinoma. SPLUNC1 gene was not expressed in the single layer columnar epithelia cells in the stomach, gallbladder, jejunum, colon, endometrium, or uterus cervix. SPLUNC1 expression was detected mainly in pseudostratified columnar epithelial cells in the nasopharynx, trachea and bronchi, and was gradually down-regulated from the upper to lower end of the respiratory tract, but was not detected in the lung tissues. SPLUNC1 expression was detected not only in the duct and serous gland cells in the parotid and submandibular glands, but also in cells of submucosal serous glands in the nasopharynx and lung, but not in the cells of the mucosal glands. The parietal cells of the gastric submucosa and epithelial cells of the lobula and ducts of the mammary glands expressed SPLUNC1. The adenocarcinoma cells in the lung, stomach, colon, mammary gland, uterus endometrium and cervix showed strong expressions of SPLUNC1 gene.</p><p><b>CONCLUSION</b>SPLUNC1 expression is highly cell-specific in association with the cell functions.</p>

Gene expression profiling of nasopharyngeal carcinoma cell line 5-8F-EGFP and the liver metastatic 5-8F-H3B-EGFP cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the gene expression profiles of nasopharyngeal carcinoma (NPC) cell line 5-8F-EGFP and the liver metastatic 5-8F-H3B-EGFP cells.</p><p><b>METHODS</b>The fluorescence-labeled cDNA were prepared separately from the total RNA extracted from the two cell lines and hybridized with Human_U133A2.0 Genechip (Affymetrix, USA) containing approximately 18 400 known gene. The gene expression profiles were analyzed with special software and cluster analysis.</p><p><b>RESULTS</b>A total of 3767 genes were identified to have significant differential expressions between these two cell lines (P<0.05), among which 281 genes showed twofold or higher differential expressions. Using MILANO software, we found 16 genes with probable close relation with liver metastasis of NPC.</p><p><b>CONCLUSION</b>The 16 genes differentially expressed between the two cell lines can be of importance in the investigation of the molecular mechanism of NPC liver metastasis and identification of molecular markers for prognostic evaluation.</p>

Isolation and detection of label-retaining cells in a nasopharyngeal carcinoma cell line / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Detection of label retaining cells (LRCs) has been a method to confirm existence of stem cells, and bromodeoxyuridine (BrdU) has commonly been used for labeling. In this study, to verify stem cells in nasopharyngeal carcinoma (NPC), LRCs were established and detected in NPC cell line 5-8F.</p><p><b>METHODS</b>The 5-8F cells were cultured with BrdU and inoculated subcutaneously into nude mice. By immunohistochemistry, immunocytochemistry, and immunofluorescence, BrdU was detected in 5-8F cells and xenograft tumors.</p><p><b>RESULTS</b>BrdU was strongly positive in cells on the 2nd and the 7th day after being added BrdU, while negative when cells were cultured without BrdU. However, only sporadic cells were positive on the 14th day after BrdU being washed out, and these cells were thought to be LRCs. The average percentage of LRCs was (0.67 +/- 0.32)%. After being cultivated with BrdU for 48 h, 5-8F cells were inoculated into nude mice subcutaneously. After chasing 8 weeks, only sporadic LRCs were detected in xenograft tumors, with a proportion of (0.55 +/- 0.36)%, and these LRCs were located at cancer margin.</p><p><b>CONCLUSION</b>The existence of LRCs in 5-8F cells indicates the existence of cancer stem cells in NPC.</p>

Screening and preliminary analysis of the apoptosis- and proliferation-related genes in nasopharyngeal carcinoma / 南方医科大学学报

<p><b>UNLABELLED</b>To screen and analyze the apoptosis- and proliferation-related genes in human nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>According to gene ontology classification, the abnormal expressions of the genes related to cell apoptosis and proliferation were identified in the NPC gene chip data. The cell apoptosis- and proliferation-related genes expressed in each of the 3 stages, as defined by the tree model for the pathogenesis and progression of NPC, were screened, and with literature review, their distribution in the tree model were analyzed.</p><p><b>RESULTS</b>Nineteen genes related to cell apoptosis were found in NPC, among which 9 were down-regulated (such as DNASE1L3) and located in the chromosome deletion regions, and 10 were up-regulated (such as DEDD) in the chromosome amplification regions. Twenty-one cell proliferation-related genes were identified, including 8 down-regulated genes (such as TUSC2) in the chromosome deletion regions and 13 up-regulated ones (such as EMP1) in the chromosome amplification regions. In the chromosome deletion regions, the down-regulated cell apoptosis-related genes participated mostly in inducing and regulating cell apoptosis, and the up-regulated cell proliferation-related genes in the chromosome amplification regions were mostly associated with the positive regulation of cell proliferation.</p><p><b>CONCLUSION</b>NPC occurs possibly through two pathways by inhibiting cell apoptosis or by promoting excessive cell proliferation.</p>

Association of the T1270533G polymorphism in GSTM1 gene coding region with susceptibility to nasopharyngeal carcinoma in a Chinese population / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of T1270533G polymorphism in the glutathione S-transferase M1 (GSTM1) gene with the susceptibility to nasopharyngeal carcinoma (NPC) and clinical phenotype of NPC in Chinese population. METHDOS: The genomic DNAs were obtained from 27 Chinese subjects, and the single nucleotide polymorphism (SNP) in all the exons and relevant intron-exon boundaries of GSTM1 were determined by PCR and direct sequencing. A case-control study was performed to analyze the SNP site T1270533G (the rare allele frequency is 22.2% in Chinese population) in the coding region by means of tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and sequencing.</p><p><b>RESULT</b>Sequence analysis identified 29 SNPs in GSTM1 gene, among which 13 SNPs presented high linkage disequilibrium with each other. No obvious relations were found between the variation in the coding region T1270533G and the clinical phenotype of NPC (RR=0.170, 95% CI =0.95-0.306 for TT homozygotes).</p><p><b>CONCLUSION</b>The missense mutation in the coding region T1270533G of GSTM1 gene that causes an amino acid change does not affect the detoxification function of GSTM1, and the T1270533G polymorphism does not have apparent relations to NPC susceptibility in Chinese subjects in Guangdong Province.</p>

Preparation and application of Epstein-Barr virus genome-wide genechip / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare an Epstein-Barr virus (EBV) microarray using known and predicted EBV-coded genes as the cDNA probes to detect the EBV gene expression in nasopharyngeal carcinoma (NPC) tissues.</p><p><b>METHODS</b>The EBV gene probes were amplified by PCR using a pair of primers designed in both sides of the multiple clone site (MCS) of the T/A vector. After purification of the PCR products, 85 EBV genes and 8000 human genes were printed onto the same slide as the detection chip consisting of both EBV and human genes. This genechip was used to detect the differential gene expression in NPC and non-cancerous nasopharynx (NP) tissues.</p><p><b>RESULTS</b>Detection of the human gene expression profile using the prepared genechip resulted in the identification of numerous human genes in the tissue specimens. Some EBV genes were also detected in the tissues using the genechip, but the signals of the genes appeared rather weak without distinctly visible fluorescence, and were not comparable to the strong signal intensities of the human genes.</p><p><b>CONCLUSION</b>The EBV microarray, though constructed successfully, can not meet the needs for clinical application due to the limited detection sensitivity and the relative small quantity of EBV gene expression in NPC samples. Further improvements of the research methods are warranted.</p>

Establishment of a stable nasopharyngeal carcinoma cell line with lentivirus-mediated RNA interference for EIF4G1 gene silencing / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a nasopharyngeal carcinoma (NPC) cell line with stable EIF4G1 gene silencing induced by small interfering RNA (siRNA).</p><p><b>METHODS</b>The EIF4G1 mRNA levels in 8 NPC cell lines including 5-8F, 6-10B, C666-1, CNE1, CNE2, HNE1, HONE1, and SUNE1 were detected by fluorescence quantitative RT-PCR (QRT-PCR). The recombinant lentivirus shRNA expression plasmid targeting EIF4G1 gene was packaged into mature lentivirus by 293FT cells and used to infect 5-8F cells. After blasticidin selection of NPC cells with constant expression of the EIF4G1-siRNA, the efficiency of EIF4G1 mRNA expression interference was determined using QRT-PCR.</p><p><b>RESULTS</b>The 8 NPC cell lines showed differential expression of EIF4G1 mRNA, among which 5-8F cells had the highest EIF4G1 expression. The recombinant lentivirus plasmid pLenti6/BLOCK-iT-DEST/EIF4G1-shRNA was successfully constructed and verified by PCR and sequencing. The EIF4G1 mRNA level of 5-8F cells infected with shRNA-EIF4G1 lentivirus was significantly reduced as compared with the negative control and the blank control cells.</p><p><b>CONCLUSION</b>The recombinant lentivirus vector pLenti6/BLOCK- iT-DEST/EIF4G1-shRNA we constructed results in marked downregulation of EIF4G1 mRNA expression and constant expression of EIF4G1-siRNA after infection of 5-8F cells.</p>

Establishment of a nude mouse model of nasopharyngeal carcinoma lymph node metastasis and screening of the metastasis-related signature genes / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a nude mouse model of nasopharyngeal carcinoma (NPC) lymph node metastasis and screen the signature genes associated with the metastasis.</p><p><b>METHODS</b>The NPC 5-8F-EGFP cells were inoculated into nude mice, from which a 5-8F-LN cell line with lymph node metastasis potential was obtained. The lymphatic metastasis-related signature genes of breast cancer and head and neck squamous cell carcinoma were screened by data mining method.</p><p><b>RESULTS</b>The NPC cell lines 5-8F and 6-10B showed 307 differentially expressed genes by microarray analysis, from which 20 overlapping genes were identified, and 3 overexpressed genes were found with probable metastasis potential, namely the ADM, IRF1, and CAV1 genes. Quantitative RT-PCR validated the data mining results in the 5-8F-EGFP, 6-10B-EGFP, NP69, and 5-8F-LN cell lines. The 3 NPC cell lines 5-8F-EGFP, 6-10B-EGFP and 5-8F-LN showed significantly higher expressions of IRF1 than NP69 cells (P=0.008, 0.022, and 0.006, respectively. The expression level of CAV1 in 5-8F-EGFP cells was significantly higher than that in 6-10B-EGFP cells (P=0.014), but ADM expression showed no significant difference between the 4 cell lines.</p><p><b>CONCLUSIONS</b>IRF1 may play an important role in the progression of NPC. The overexpression of CAV1 in 5-8F-EGFP cells can be associated with the high metastatic potential of the cells.</p>

Expression of ATP-binding cassette transporter genes in nasopharyngeal carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the differences in the expression of the ATP-binding cassette (ABC) transporter genes between normal nasopharyngeal tissue and nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Real-time quantitative PCR was used to examine the gene expression of 10 ABC transporters in both NPC and normal nasopharyngeal tissue.</p><p><b>RESULTS</b>The 10 drug resistance-associated ABC transporters were expressed at different levels in NPC. ABCA2 and ABCC3 genes were strongly expressed in both the NPC and normal nasopharyngeal tissues, and ABCC1, ABCC5 and ABCG2 gene expressions were significantly higher in NPC than in normal nasopharyngeal tissue, whereas the ABCB1, ABCC2, ABCC3, ABCC4, ABCC6 and ABCC11 genes were all expressed at low levels in both the carcinoma and normal tissues.</p><p><b>CONCLUSION</b>The transporters with high expressions in both the cancer and normal samples are correlated to the naturally occurring multidrug resistance of NPC, and those with high expression only in NPC may play an important role in drug resistance to chemotherapeuatic agents. The agents targeting the ABC transporters that are lowly expressed in both the carcinoma and normal tissues might serve as sensitivitive chemotherapeutics against NPC.</p>

AF172993 sequence of Plunc in GenBank database is not the complete CDS / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine AF172993 sequence is either the complete CDS or a transcript variant.</p><p><b>METHODS</b>RT-PCR was used to amplify the CDS sequence of Plunc, which was subsequently cloned into the pEGFP-N1 eukaryotic expression vector. After bi-directional sequence analysis, the sequence obtained was blasted against the AF172993 sequence, nr database and human genome database.</p><p><b>RESULTS</b>In CDS of the new cloned sequence, the 658 base A in the AF172993 sequence was replaced by C, and the corresponding genetic code was also converted from AAG to CAG, leading to the alteration of the amino acid Gln to Lys. In addition, the base C at the 658 position of the CDS showed perfect match with the base C at 2094188 position in human chromosome 20.</p><p><b>CONCLUSION</b>The base A at the 658 position of AF172993 sequence of Plunc is a mutation site, which alters the coding of the amino acid. AF172993 sequence is actually a transcript variant of Plunc, and the annotation to AF172993 in GenBank database is not correct and need to be revised.</p>

Immunoediting of natural killer cells by human nasopharyngeal carcinoma cell line: altered expression of KIRs and NKG2D receptors leads to reduction of natural killer cell-mediated cytolysis / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the changes of inhibitory killer cell immunoglobulin-like receptors (KIRs), NKG2D receptor and the cytotoxicity of natural killer (NK) cells induced by persistent exposure to CNE2 cells.</p><p><b>METHODS</b>The HLA-class I genotypes of CNE2 cells and KIR genotypes were determined by PCR with sequence-specific primers (PCR-SSP). The expressions of KIR2DL1, KIR2DL3, KIR3DL1, and NKG2D by the NK cells (freshly isolated NK cells, NK cells cocultured with 100 U/ml IL2 or with 100 U/ml IL2 and CNE2 cells as the control, IL2 and CNE2 groups, respectively) were analyzed by flow cytometry. Cytotoxicity of NK cells against CNE2 cells were detected by LDH releasing assay.</p><p><b>RESULTS</b>The HLA genotypes of CNE2 cells were A2, 24, B18, 35, Cw4, 7. NK cells isolated from 3 healthy donors expressed KIR2DL1, KIR2DL3, and KIR3DL1. After 4, 24 and 48 h of culture, NK cells in CNE2 group displayed higher KIR2DL1, KIR2DL3 but lower NKG2D expression than those in the control and IL2 groups (P<0.01), whereas the latter two groups showed no significant difference in KIR2DL1, KIR2DL3, and NKG2D expressions (P>0.05), and no difference in KIR3DL1 expression was found between the 3 groups (P>0.05). After 24 h of culture, the cytotoxicity against CNE2 cells mediated by the NK cells in IL2 and CNE2 groups were (26.96-/+1.47) % and (2.74-/+1.64) % at E:T ratios of 10:1, and (35.74-/+3.59)% and (4.57-/+2.41) % at E:T ratio of 20:1, respectively. NK cells in CNE2 group displayed lower cytotoxicity than those in IL2 group (P<0.01).</p><p><b>CONCLUSIONS</b>Persistent exposure to tumor cells expressing NKG2D ligands can lead to downregulated expression of NKG2D receptor, increased expression of KIRs and reduction of NK-mediated cytolysis. These results elucidate the molecular mechanism of reduced cytotoxicity mediated by the edited NK cells and indicate that blocking HLA-class I-bound KIRs or enhancing the expression of NKG2D may promote NK cell-mediated cytolysis.</p>

Differentially expressed transcription factor-related genes in nasopharyngeal carcinoma and nasopharyngeal tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the gene expression profiles of transcription factor-related genes in nasopharyngeal carcinoma (NPC) tissues and normal nasopharyngeal tissues using a cDNA microarray membrane for exploring the regulatory mechanism of differential gene express in NPC tissues.</p><p><b>METHODS</b>The total RNAs from 24 NPC tissues and 24 pooled normal nasopharyngeal tissues were reverse transcribed and labeled with alpha-(32)P-dCTP. The resultant cDNAs were hybridized to GF211 microarray, and the signals were analyzed by Pathway 4.0 software. RT-PCR was carried out to confirm the results.</p><p><b>RESULTS</b>Among the 1625 differentially expressed genes detected in NPC and nasopharyngeal tissues, 35 transcription factor-related genes were identified with either up- or down-regulation.</p><p><b>CONCLUSION</b>These differentially expressed transcription factor-related genes in NPC tissues might play a role in the regulation of NPC-related gene expression.</p>

PTX1 in nasopharyngeal carcinoma by RNAi technology / 中南大学学报(医学版)

OBJECTIVE@#To explore the expression and the role of PTX1 located at the amplified 12p12-p11 region in nasopharyngeal carcinoma (NPC).@*METHODS@#Semi-quantitative RT-PCR and real-time RT-PCR were applied to detect the expression level of PTX1 in 36 NPC and 8 chronic nasopharyngitis (NP) biopsies. RNAi vector targeting PTX1 was constructed and transfected into NPC cell line 6-10B. The RNAi effect was determined by detecting the expression level of PTX1 in transfected 6-10B cell line. Finally, the cell biological characteristics were compared between transfected 6-10B and parental 6-10B by analyzing the cell cycle distribution and apoptosis status using flow cytometry.@*RESULTS@#RT-PCR and real-time RT-PCR revealed that PTX1 gene was over-expressed in NPC tissues (P<0.05). PTX1 expression was suppressed in NPC cell line 6-10B by approximately 65% by RNAi, confirmed by RT-PCR. The depletion of PTX1 could effectively block the proliferation and induce the apoptosis of NPC cells.@*CONCLUSION@#Blocking the expression of PTX1 on mRNA level changed the characterization of NPC cell line 6-10B by RNAi, suggesting that PTX1 identified in the amplified 12p12-p11 region may be involved in the genesis and development of NPC via promoting the cell proliferation and inhibiting the cell apoptosis.

Establishment of hepatic metastatic subline of nasopharyngeal carcinoma cell line / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a hepatic metastatic subline of nasopharyngeal carcinoma (NPC) cell line.</p><p><b>METHODS</b>NPC cells metastatic to the liver were isolated from nude mice and the invasion and metastatic ability of the cells was observed in vivo and in vitro.</p><p><b>RESULTS AND CONCLUSION</b>The invasion and metastasis activity of 5-8F-H3B-EGFP (an in vivo isolate with enhanced liver metastatic behaviors) were enhanced obviously in comparison with the parent cell line 5-8F-EGFP. This subline may be useful for cloning genes related to liver metastasis of NPC.</p>

Construction of hu-PBL/SCID chimeras and development of EBV-related lymphomas / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV).</p><p><b>METHODS</b>Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient (SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experimental animals and induced neoplasms.</p><p><b>RESULTS</b>In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence.</p><p><b>CONCLUSIONS</b>EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.</p>

Exploration of multigene, multistep and multipathway model of nasopharyngeal and colorectal carcinogenesis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To construct tree models for nasopharyngeal carcinoma (NPC)and explore the oncogenesis process of NPC.</p><p><b>METHODS</b>Based on the software which Desper et al developed, tree models were constructed for colorectal carcinoma (CC) from the comparative genomic hybridization (CGH) data of 118 CC patients and for NPC from the CGH data of 140 southern Chinese patients, respectively.</p><p><b>RESULTS</b>Tree models for CC suggested that changes in -18q and +20q were important early events in colorectal carcinogenesis. As changes in -18q occurred prior to those in -17p, there might be some cause-effect relationship. Tree models for NPC suggested that change in -3p was an important early event in nasopharyngeal carcinogenesis, and those in -11q, -14q, -16q, -9p were also non-random genetic events in carcinogenesis, suggesting that there might be tumor-associated genes existing on these chromosome arms. The tree model also suggested the existence of oncogene on the short arm of chromosome 12.</p><p><b>CONCLUSION</b>Constructing tree models based on the CGH data to demonstrate the initiation and progression of NPC might help elucidate its multigene, multistep and multipathway development. It may provide valuable clues to explore the mechanism of tumorigenesis.</p>

Study on etiology and pathology of severe acute respiratory syndrome / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathologic characteristics of severe acute respiratory syndrome (SARS).</p><p><b>METHODS</b>Three autopsy cases were studied retrospectively. Routine HE stain was used to study all the cases. Part of the lung tissue specimens were studied further with Macchiavello's stain, viral inclusion body stain, reticulin and PAS stains, immunohistochemistry, thin sections with staining, light microscopy and transmission electronic microscope investigation.</p><p><b>RESULTS</b>The earliest symptom of all 3 cases was hyperpyrexia and followed by progressive dyspnea and appearance of lung field shadows in X rays findings. Pulmonary lesions included: bilateral and extensive consolidation, localized hemorrhage and necrosis, desquamative alveolitis and bronchitis, alveolar proliferation and desquamation, accumulation of protein exudates, mononuclear cells, lymphocytes, and plasma cells as well as hyaline membrane formation in alveoli and viral inclusion bodies were seen in the alveolus epithelial cells. The exudated organization tended to become glomeruloid organizing pneumonitis in a few avaoli. Lesions of the immune organs included: large patchy necrosis in the spleens and localized necrosis in the lymph nodes were seen. Bone marrow became restrained. There were lesions of systemic small vasculitis including edema of the perivascular tissue and vascular wall of the small veins with localized fibrinoid necrosis distributing in the heart, lungs, kidneys, adrenal glands and the striated muscles accompanying with mononuclear cells and lymphocytes infiltration. Thrombosis was seen in part of the small veins. In addition, there were also the systemic poisonous changes including: degeneration and necrosis of the parenchyma cells in lungs, liver, kidneys, heart and adrenals. Electronic microscopy demonstrated clusters of virus particles seen in the lung tissue.</p><p><b>CONCLUSION</b>SARS is a systemic disease. Lungs, immune system and systemic small vessels are the main target organs attacked by the virus. Extensive consolidation of lungs, formation of hyaline membrane to a large extent, respiratory distress and decrease of immune function are the main causes of death.</p>