Analysis of one case of adolescent blastic plasmacytoid dendritic cell neoplasm / 中国实验血液学杂志

This study was purposed to summarize the clinical characteristics and laboratorial data of blastic plasmacytoid dendritic cell neoplasm (BPDCN) in pediatric patients in order to enhance understanding this disease in diagnosis and therapy. A rare case of BPDCN in children was enrolled in this study. The blood routine test, examination of bone marrow cell morphology, histopathology and immunophenotype of the skin lesions were performed and analysed, the single cell suspensions of the biopsied skin mass were detected by flow cytometry. The results showed that tumor cells expressed CD4, CD56, CD43 and CD123, while not expressed CD19, CD20, CD3, CD8, CD13, CD11b and myeloperoxidase (MPO). According to the clinical and laboratorial features and the results from histopathological and immunophenotype examinations, BPDCN was confirmed. It is concluded that BPDCN in children is an extremely rare hematopoietic malignancy with presenting a rapidly and fatally aggressive clinical course. The diagnosis of this disease is mainly based on the clinical presentations, pathologic and immunohistochemical features. BPDCN is a highly aggressive disease, its prognosis is very poor, its pathogenesis remans still unclear. A standard treatment protocol for BPDCN has not yet been established.

Outcome of children and adolescents with Burkitt lymphoma and diffuse large B cell lymphoma treated with a modified NHL-BFM-90 protocol / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of a modified NHL-BFM-90 protocol in childhood and adolescence with Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL).</p><p><b>METHODS</b>A total of 138 de novo patients with BL and DLBCL were enrolled. All patients were stratified into low (R1), intermediate (R2) and high risk (R3) groups based on the stage, chemotherapy response and LDH level, and treated with a modified NHL-BFM 90 protocol.</p><p><b>RESULTS</b>Of the 138 patients, 105 were boys and 33 girls, with a median age at diagnosis of 7.5 yr (range 1.5 to 20.0 yr). Eighty-two cases were BL, 56 cases DLBCL. The patients with stage III/IV accounted for 76.1%. Thirty-one patients were assigned to group R1, 38 patients group R2, and 69 patients group R3. Complete remission (CR) after chemotherapy was 90.6%. At a median follow-up of 50 months(1-158 months), a total of 19 patients died of disease. The 5-year event free survival (EFS) and overall survival (OS) for the entire group were 85.8%, 85.8% respectively. 5-year EFS was 97.1% for stage I/II, 82.1% for stage III/IV respectively (P=0.039); and 96.7%, 86.8% and 80.2% for groups R1, R2 and R3 respectively (P=0.135); and 85.2% and 86.9% for BL and DLBCL respectively (P=0.635). Major toxicity was myelosuppression, which was tolerant and manageable.</p><p><b>CONCLUSION</b>That the modified NHL-BFM-90 protocol was highly effective for children and adolescents with BL and DLBCL, and especially improved the survival of the advanced patients.</p>

Clinicopathologic study of 963 cases of mature T-cell and natural killer/T-cell lymphoma with respect to 2008 WHO classification of lymphoid neoplasms / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of various types of mature T-cell and natural killer (NK)/T-cell lymphoma in Guangdong, China, with respect to the 2008 WHO classification of lymphoid neoplasms.</p><p><b>METHODS</b>Eleven hundred and thirty-seven (1137) cases of mature T-cell or NK/T-cell lymphoma diagnosed during the period from 2002 to 2006 in Guangzhou area were retrieved. The clinical data, histologic features and immunohistochemical findings were reviewed by a panel of experienced hematopathologists. Additional immunostaining was performed if indicated. The cases were re-classified according to the 2008 WHO classification of lymphoid neoplasms.</p><p><b>RESULTS</b>Nine hundred and sixty-three (963) cases fulfilled the diagnostic criteria of mature T-cell or NK/T-cell lymphoma and accounted for 20.1% of all cases of lymphoma encountered during the same period (963/4801). A predominance of extranodal involvement was noted in 644 cases (66.9%), while 319 cases (33.1%) showed mainly nodal disease. The prevalence of various lymphoma subtypes was as follows: peripheral T-cell lymphoma, unspecified (PTCL, NOS) 293 cases (30.4%), extranodal NK/T-cell lymphoma, nasal type 281 cases (29.2%), anaplastic large cell lymphoma (ALCL) 198 cases (20.6%), and angioimmunoblastic T-cell lymphoma (AILT) 46 cases (4.8%). The male-to-female ratio was 1.99. The median age of the patients was 44 years, with the peak age of PTCL, NOS, extranodal NK/T-cell lymphoma, nasal type and AILT being 55 to 64 years, 25 to 54 years and 65 to 74 years, respectively. ALK-positive ALCL occurred more frequently in young age, while the ALK-negative ALCL cases occurred mainly in the elderly.</p><p><b>CONCLUSIONS</b>Extranodal lesions predominate in mature T-cell and NK/T-cell lymphomas occurring in Guangzhou area. There is a male predominance and the overall incidence shows no increasing trend with age of the patient. The peak age of various subtypes however varies. The most common subtype was PTCL, NOS, followed by extranodal NK/T-cell lymphoma, nasal type, ALCL and AILT. The relatively frequent occurrence of extranodal NK/T-cell lymphoma, nasal type in Guangdong area is likely associated with the high incidence of Epstein-Barr virus infection there.</p>

Follicular dendritic cell sarcoma: a clinicopathologic analysis of ten cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of follicular dendritic cell sarcoma (FDCS) and its differential diagnosis.</p><p><b>METHODS</b>Ten cases of FDCS were studied by light microscopy, immunohistochemistry and in-situ hybridization. The clinical features and follow-up information were analyzed.</p><p><b>RESULTS</b>Amongst the 10 cases of FDCS studied, the male-to-female ratio was 1:1. The mean age of the patients was 42 years. Six of them were located in cervical and peritoneal lymph nodes and four in extranodal sites (including tonsil, pelvic cavity, tail of pancreas and spleen). Histologically, the tumor cells had whorled, storiform or diffuse growth patterns. They were spindle in shape and contained syncytial eosinophilic cytoplasm, with round or oval nuclei, vesicular chromatin, distinct nucleoli and a variable number of mitotic figures. Multinucleated tumor giant cells and intranuclear pseudoinclusions were occasionally seen. There was a sprinkling of small lymphocytes and neutrophils within the tumor as well as in the perivascular region. Immunohistochemical study showed that the tumor cells were diffusely or focally positive for CD21, CD23, CD35 and D2-40, but negative for LCA, CD20, CD3, CD1a, HMB45 and CK. Some of them showed EMA, CD68 and S-100 reactivity. In-situ hybridization for Epstein-Barr virus-encoded RNA (EBER) showed positive signals in only one case (which was diagnosed as inflammatory pseudotumor-like FDCS). Of the 7 patients with follow-up information available (duration: 2 months to 39 months; mean: 14 months), 2 cases with paraneoplastic pemphigus died of pulmonary infection at 5 and 7 months respectively. The remaining 5 patients were alive and disease-free after surgical excision (+/- chemotherapy and radiotherapy).</p><p><b>CONCLUSIONS</b>FDCS is a rare low to intermediate-grade malignant tumor. Appropriate application of FDC markers, such as CD21, CD35 and D2-40, would be helpful for arriving at a correct diagnosis. Most cases are associated with good prognosis after surgical treatment, with or without chemotherapy and radiotherapy. Patients with paraneoplastic pemphigus carry a less favorable prognosis.</p>

Inhibitory effect of angiogenesis inhibitor YH-16 in combination with 5-FU on liver metastasis of colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To study the effect of angiogenesis inhibitor YH-16 in combination with 5-FU on liver metastasis of colorectal cancer.</p><p><b>METHODS</b>In vitro, the inhibitory effects of YH-16 and 5-FU on the growth of vascular endothelial cells and colorectal cancer cells were examined by MTT assay. In vivo, colorectal cancer cells were transplanted into BALB/c mice, and the mice were divided into six groups randomly:control group, low-dose YH-16 group, middle-dose YH-16 group, high-dose YH-16 group, 5-FU group and combination group. The number of liver metastases, the size of primary tumor and the toxicity were examined after 2 weeks postoperatively. The expression of vascular endothelial growth factor (VEGF) in liver metastases was detected by immunohistochemistry, and tumor microvessel density (MVD) was measured by immunostaining with CD34 and factor VIII (monoclonal antibodies.</p><p><b>RESULTS</b>In vitro, YH-16 inhibited the growth of colon cancer cells and vascular endothelial cells, with the IC50 at (2.16+/-0.28) microg/ml and (0.64+/-0.10) microg/ml respectively. In vivo high-dose YH-16 and 5-FU had a remarkable inhibitory effect on liver metastasis, and the combination group showed significant enhancement on this effect (P< 0.05). The combination group and 5-FU group could inhibit the growth of primary tumor, but not found in YH-16 group. The toxicity of YH-16 was lower than that of 5-FU (P< 0.05), and the difference was not found in the toxicity between combination group and 5-FU group (P > 0.05). Expression of VEGF in liver metastases was clearly inhibited by YH-16 in combination with 5-FU or 5-FU alone compared to the control group, and MVD in middle-dose and high-dose YH-16 group, 5-FU group and combination group was lower than that in control group (P< 0.05).</p><p><b>CONCLUSIONS</b>The angiogenesis inhibitor YH-16 can inhibit liver metastasis of colorectal cancer through inhibiting the growth of vascular endothelial cells. YH-16 in combination with 5-FU has additive effect on inhibitory activity against liver metastasis.</p>

Study of sequence variations of Epstein-Barr virus LMP1 gene in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect the sequence variations frequently found within the N- and C-terminal regions of Epstein-Barr virus (EBV) LMP1 gene in nasopharyngeal carcinoma (NPC) and to study the underlying mechanisms.</p><p><b>METHODS</b>Fresh tumor tissues were sampled from 63 patients with untreated NPC encountered in Affiliated Tumor Hospital of Sun Yat-sen University, Guangzhou. The N-terminal region of EBV LMP1 gene was amplified with nested polymerase chain reaction (PCR), followed by XhoI enzyme digestion. Nested PCR was also employed to detect the 30 base pairs deletion within the C-terminal region. Four-colored fluorescence terminator sequencing method was applied for bi-directional solid-phase sequencing of the 8 representative PCR products in 4 cases of NPC. The DNA sequence within the N- and C-terminal regions of LMP1 gene was then analyzed.</p><p><b>RESULTS</b>There were 4 patterns of sequence variations, namely, wt-XhoI/wt-LMP1 (4 cases, 6.3%), wt-XhoI and XhoI-loss/del-LMP1 (4 cases, 6.3%), wt-XhoI/del-LMP1 (5 cases, 7.9%) and XhoI-loss/del-LMP1 (50 cases, 79.5%), detected in the 63 studied cases. Sequence analysis showed that the EBV LMP1 gene had underwent non-synonymous and synonymous substitutions, as compared with the prototype of B95-8 cells. The ratio of non-synonymous to synonymous substitutions was 2.25.</p><p><b>CONCLUSIONS</b>XhoI-loss/del-LMP1 is the predominant sequence variation pattern of EBV LMP1 gene in NPC from Guangzhou. The XhoI-loss variation seems to develop on top of del-LMP1. When compared with the EBV LMP1 gene in peripheral blood B-lymphocytes of virus carriers and in preinvasive epithelial lesions (reported previously), it is likely that the sequence variation patterns of LMP1 gene may represent 4 different phases of intrahost evolution of EBV during nasopharyngeal carcinogenesis.</p>

Expression of hepatocyte growth factor/c-Met system in nasopharyngeal carcinoma and its biological significance / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of hepatocyte growth factor (HGF), and its receptor c-Met protein in nasopharyngeal carcinoma (NPC) and CNE-2 NPC cell line, to correlate their expression level with clinicopathologic features and to study the effect of HGF/c-Met system on the invasive and metastatic potential of NPC.</p><p><b>METHODS</b>Forty-five biopsies were collected from pre-treatment NPC patients during the period from 1999 to 2003. Immunohistochemical staining was used to detect the expression of HGF-alpha subunit and c-Met protein in NPC tissues. The association between expression of these proteins and clinicopathologic features was statistically analyzed. The expression of HGF and c-Met, as detected by flow cytometry, in CNE-2 NPC cell line (with or without exogenous HGF) was compared. Western blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) were also applied to evaluate the protein and mRNA expression of c-Met in CNE-2 cells.</p><p><b>RESULTS</b>In the 45 cases studied, the expression rate of c-Met was 91.1% (41/45). Only 1 case (2.2%, 1/45) showed positive signal for HGF in neoplastic cells. Instead, HGF was expressed in surrounding lymphocytes. The expression of c-Met positively correlated with lymph node metastasis (P = 0.024). There was also a positive correlation between expression of c-Met by tumor cells and expression of HGF by surrounding lymphocytes (r(s) = 0.450, P = 0.002). Moreover, the expression of c-Met was higher if there was a higher expression of HGF by lymphocytes (P = 0.009). However, there was no association between expression of c-Met and clinicopathologic features, such as age, gender, histopathologic type and clinical stage. After treatment with HGF for 24 hours, the percentage of c-Met-positive cells was significantly increased in CNE-2 cell line, from (46.6 +/- 9.02)% to (85.8 +/- 6.05)% (P = 0.003). The c-Met protein expression and c-Met mRNA level were also enhanced in CNE-2 cells with HGF treatment. However, endogenous HGF was not detected in CNE-2 cells, regardless of HGF treatment.</p><p><b>CONCLUSIONS</b>HGF may play an important role in the development of NPC metastasis by inducing the expression of c-Met in tumor cells via a paracrine, instead of an autocrine, pathway.</p>

Increased cell migration of nasopharyngeal carcinoma cell lines in vitro by macrophage migration inhibitory factor / 中华病理学杂志

<p><b>OBJECTIVE</b>To study whether macrophage migration inhibitory factor (MIF) can increase the ability of invasion of nasopharyngeal carcinoma cell lines in vitro, and to investigate the mechanism of invasion and metastasis of tumor cells during the early stage of nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>The invasion and migration of NPC cell lines, CNE-1 and CNE-2, were evaluated by micron-migration assay in a chamber with 8- micro m porosity polycarbonate filter membrane. Flow cytometry and western blotting were adopted respectively to evaluate the protein expression level of matrix metalloproteinase 2 and 9 (MMP2, MMP9) in MIF treated or non-treated tumor cell lines. The concentrations of interleukin 8 (IL-8) secreted into the culture supernatant by the cells were measured by using Enzyme-linked immunoabsorbent assay (ELISA).</p><p><b>RESULTS</b>(1) After treatment with MIF for 24 hours, the number of cells passing through the 8- micro m filter membrane were increased in CNE-1 (113.7 +/- 20.9) and CNE-2 (311.3 +/- 48.9), as compared with that of non-MIF treated NPC cells. A significant statistic difference (P = 0.005, P = 0.001) was obtained in both CNE-1 and CNE-2 cells. (2) After treatment with MIF, the number of MMP9-positive cells increased in both CNE-1 (from 28.5% +/- 2.45% to 82.4% +/- 3.49%, P = 0.001) and CNE-2 (from 32.8% +/- 3.48% to 86.1% +/- 1.62%, P = 0.002) cell lines. In addition, an enhanced MMP9 protein expression up to 3-fold was observed in both cell lines. However, the expression level of MMP2 did not changed significantly between treated and non-treated cell lines (P > 0.05). (3) The concentration of IL-8 in the culture supernatant of CNE-2 was 1201.8 +/- 593.3 pg/ml after treatment with MIF for 24 h, remarkably higher than that without MIF treatment (32.7 +/- 20.1 pg/ml, P = 0.026). A similar change was not detected in CNE-1 (P = 0.581) cells.</p><p><b>CONCLUSIONS</b>(1) MIF can increase cell migration of CNE-1 and CNE-2 NPC cell lines in vitro. (2) A higher expression level of MMP9 and an up-regulated IL-8 by MIF may play a very important role in the progress of NPC, such as invasion and metastasis.</p>

Value of EBNA1-IgA and EA-IgG in serological diagnosis of nasopharyngeal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the value of EBNA1-IgA and EA-IgG in serological diagnosis of nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>The serum EBNA1-IgA and EA-IgG of 56 patients with NPC and 58 healthy adults were detected by ELISA. The sensitivity, specificity, positive predictive value, accuracy rate and odds ratio of the two tests used singly or in combination were compared with each other.</p><p><b>RESULTS</b>The sensitivity of EBNA1-IgA (91.07%) was higher than that of EA-IgG (87.50%), while the specificity of EA-IgG (87.93%) was higher than that of EBNA1-IgA (84.48%). The combination of EBNA1-IgA and EA-IgG could enhance the specificity (94.83%), positive predictive value (0.9375), likelihood ratio (15.5435) and odds ratio (75.0000) for serological diagnosis of NPC. Forty-five patients showed both positive EBNA1-IgA and positive EA-IgG. A positive EA-IgG was detected in 4 out of 5 patients with negative EBNA1-IgA and a positive EBNA1-IgA was founded in 6 out of 7 patients with negative EA-IgG.</p><p><b>CONCLUSION</b>Although relatively high sensitivity and specificity could be obtained by either EBNA1-IgA or EA-IgG test alone, the combination of these two tests with a complementary effect is able to enhance the reliability of serological diagnosis of NPC as most patients have positive ENBA1-IgA and EA-IgG concurrently.</p>

Association of E-cadherin and beta-catenin with metastasis in nasopharyngeal carcinoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was designed to detect methylation of E-cadherin gene promoter and gene mutation of beta-catenin in exon 3 and their expression of protein and mRNA in primary tumor and lymph node metastatic tumor of nasopharyngeal carcinoma (NPC), and investigate the mechanism of invasion and metastasis of neoplastic cells in NPC.</p><p><b>METHODS</b>Fourty-two fresh biopsy samples were taken from untreated NPC patients at the Affiliated Hospital of Sun Yat-sen Medical College, Sun Yat-sen University, Guangzhou, China during the period of 1999-2002. Among them 21 were taken from primary tumors and the other 21 from lymph node metastatic tumors. The gene promoter methylation of E-cadherin was detected by methylation-specific PCR (MSP). The mutation in exon 3 of beta-catenin was detected by direct sequencing analysis. RT-PCR, Western blot and immunohistochemical staining were used to detect the mRNA and protein expression patterns in both primary and metastatic tumors of NPC.</p><p><b>RESULTS</b>Down-regulated expression of E-cadherin in metastatic tumor was compared with that in primary tumor. Reduced expression of E-cadherin was found to be correlated with lymph node metastatic tumor of NPC (P = 0.004); but there was no obvious correlation between primary and metastatic tumors in the expression of beta-catenin (P = 0.698). The mRNA expression level of E-cadherin in metastatic tumors decreased significantly compared with that in primary tumors. However, little change was observed in the mRNA level of beta-catenin in different tumor tissues. Only 4 samples (19.1%) displayed gene promoter methylation of E-cadherin in primary tumor and 10 samples (47.6%) showed methylated form of E-cadherin. The gene promoter methylation of E-cadherin was more common in metastatic tumor than in primary tumor of NPC (P = 0.024). Only 2 (4.76%) of the 42 samples showed mutations in exon 3 of beta-catenin at 41 (T41A, ACC-->GCC) and codon 47 (S47T, AGT-->ACT). The cytoplasmic and nuclear expression of beta-catenin in tumor was not found in any samples of NPC.</p><p><b>CONCLUSIONS</b>The results suggest that the downregulation of E-cadherin results from the gene promoter aberrant methylation of E-cadherin and that the methylation of E-cadherin plays an important role in invasion and metastasis of tumor cells in NPC. However, beta-catenin mutation is an infrequent event in NPC, and beta-catenin is not a critical factor influencing the invasion and metastasis of tumor cells in NPC.</p>

Macrophage migration inhibitory factor enhances neoplastic cell invasion by inducing the expression of matrix metalloproteinase 9 and interleukin-8 in nasopharyngeal carcinoma cell lines / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nasopharyngeal carcinoma (NPC) shows highly invasive and metastatic features. This study aims to investigate macrophage migration inhibitory factor (MIF)-induced invasion of NPC cells in vitro and the effects on matrix metalloproteinases (MMPs) and interleukin-8 (IL-8), and to study the mechanism of tumor cell invasion and metastasis in the early stage of NPC.</p><p><b>METHODS</b>Two nasopharyngeal carcinoma cell lines, CNE-1 and CNE-2, were adopted in this study. The NPC cell invasion and migration were evaluated by microinvasion assay. The variation of expression percentages of MMP2- or MMP9-positive cells was detected by flow cytometry in two cell lines with or without MIF treatment. Western blotting and RT-PCR were used to assay the protein and mRNA expressions of MMP2 and MMP9. The IL-8 concentration secreted by NPC cells was compared with the cells with different treatments using ELISA.</p><p><b>RESULTS</b>After treating with MIF for 48 hours, the cell numbers of CNE-1 and CNE-2 which went through the 8-microm filter membrane were increased. Compared with non-MIF treated NPC cells, significant difference could be found both in CNE-1 (P = 0.005) and CNE-2 cells (P = 0.001). The percentages of MMP9-positive cells were significantly increased in both CNE-1 [from (28.5 +/- 2.5)% to (82.4 +/- 3.5)%, P = 0.001] and CNE-2 [from (32.8 +/- 3.5)% to (86.1 +/- 1.6)%, P = 0.002]. The relative intensity of MMP9 protein expression was also enhanced in both cell lines (CNE-1: from 83.1 +/- 6.0 to 242.9 +/- 22.9, P = 0.002; CNE-2: from 84.4 +/- 4.3 to 278.9 +/- 29.7, P = 0.003). Correspondingly, the increased MMP9 mRNA expression level was significantly detectable in both cell lines. The concentration of IL-8 in the supernatant of CNE-2 was higher [(1201.8 +/- 593.3) pg/ml] after treatment. It was also remarkably higher than that in the supernatant of CNE-2 without treatment (P = 0.026). However, there was no significant difference in the concentration variation of IL-8 in CNE-1 (P = 0.581), while the IL-8 mRNA level was only enhanced in CNE-2.</p><p><b>CONCLUSIONS</b>MIF can induce potent invasion of NPC cell lines in vitro, and the infiltrating lymphocytes in NPC might be responsible for the invasion and metastasis of tumor cells. MIF cytokine which is secreted by these infiltrating lymphocytes might contribute to the invasion as well as metastasis of NPC in the early stages by induction of MMP9 and IL-8 in an indirect pathway.</p>

Comparison of the Epstein-Barr virus infection and 30 bp-deleted LMP1 gene among 4 histologic types of nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To compare the Epstein-Barr virus (EBV) infection rates and the frequencies of wt-LMP1 and del-LMP1 EBV variants detected singly or dually among the four types of nasopharyngeal carcinoma (NPC) and to illustrate the possible role of del-LMP1 gene in nasopharyngeal carcinogenesis.</p><p><b>METHODS</b>EBER in situ hybridization was performed in 117 NPCs, including 48 non-keratinizing carcinomas (NKCs), 25 keratinizing squamous cell carcinomas (KSCCs), 5 adenosquamous carcinomas (ASCs), 6 mucoepidermoid carcinomas (MECs) and 33 adenocarcinomas (ACs). Nested PCR for demonstration of EBV LMP1 gene was performed on the tissue samples collected from 99 EBER-positive carcinoma cases and the peripheral blood mononuclear cells (PBMCs) of 53 healthy adults (HAs).</p><p><b>RESULTS</b>As indicated by EBER in-situ hybridization, the EBV infection rates in both of 48 NKCs and 25 KSCCs were 100%; and the infection rates of 11 ASCs/MECs and 33 ACs were 9/11 and 51.5% (17/33), respectively. Worthy to note was that most of the NKC cells were EBER-positive while only a small number of EBER-positive neoplastic cells could be found in 17 ACs. The percentage of del-LMP1 EBV variant detected singly in NKCs (85.4%, 41/48) was not only significantly higher than that in PBMCs of 46 HAs (8.7%, 4/46) but also significantly higher than those detected in KSCCs (16.0%, 4/25). The dual infection rate of wt-LMP1 and del-LMP1 variants detected in KSCCs (56.0%, 14/25) was significantly higher than that of NKCs (12.5%, 6/48). The majority of the EBV detected in AC tissues (12/17) and HAs' PBMCs (34/46, 73.7%) were of dual wt-LMP1 and del-LMP1 variants.</p><p><b>CONCLUSIONS</b>The EBV infection rates are significantly different among 3 major histological categories, namely, NKC/KSCC, ASC/MEC and AC. Though NKCs and KSCCs are always consistently associated with EBV, the single del-LMP1 EBV variant detected in NKCs is predominant over that in KSCCs and most of the KSCCs contain dual wt-LMP1 and del-LMP1 EBV variants. The EBV of the del-LMP1 variant might play a crucial role in carcinogenesis of NKC.</p>

Analysis of Epstein-Barr virus with BamHI "f" variant and XhoI-loss of LMP1 gene in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the genomic variation of Epstein-Barr virus (EBV) and its significance in nasopharyngeal carcinogenesis.</p><p><b>METHODS</b>Forty nasopharyngeal carcinoma (NPC) biopsy tissues were used for detection of EBV BamHI f variant and LMP1 XhoI-loss by polymerase chain reaction (PCR), nested PCR, and RFLP (restriction fragment length polymorphism). Forty-eight samples of peripheral blood mononuclear cells (PBMC) taken from apparently healthy adult individuals were used for detection of LMP1 XhoI-loss. Three samples of amplified LMP1 exon 1 DNA from B95-8 cell line and 2 NPC tissues (one having XhoI-loss and the other having Wt-XhoI/XhoI-loss) were sequenced.</p><p><b>RESULTS</b>Thirty out of the 40 NPC cases (30/40, 75%) harbored EBV BamHI f variant and the remaining 10 (10/40, 25%) harbored BamHI F prototype. Thirty out of the 39 NPCs (30/39, 76.9%) showed single EBV LMP1 XhoI-loss, 7 (7/39, 18.0%) showed single LMP1 Wt-XhoI (presence of a XhoI site in exon 1 of LMP1 gene, as in B95-8 cell line), and 2 (2/39, 5.1%) showed both LMP1 Wt-XhoI and XhoI-loss. Thirty-eight of the 39 NPCs (97.4%) showed EBV LMP1 XhoI-loss or/and BamHI F variant. In the NPC tissue (1 case only) showing the prototype of Wt-XhoI/BamHI "f", there were several base substitutions, including 5 missense mutations and 2 silent mutations present in LMP1 exon 3, on DNA sequencing. On the other hand, 10 out of the 48 samples of PBMC taken from apparently healthy individuals could be amplified successfully by nested PCR for detection of LMP1 XhoI site. All of these 10 samples carried the prototype of EBV LMP1 Wt-XhoI.</p><p><b>CONCLUSIONS</b>The majority of EBV present in neoplastic cells of NPC is of BamHI "f" variant and/or possesses LMP1 XhoI-loss, as compared with that in healthy individuals. This genomic variation of EBV may bear some roles in the development and progression of NPC.</p>

Detection of gene promoter methylation and mRNA, protein expression levels of E-cadherin in nasopharyngeal carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To detect the gene promoter methylation, mRNA and protein expression levels of E-cadherin and beta-catenin in primary and metastatic tumor samples of nasopharyngeal carcinoma (NPC), and to investigate the mechanism of invasion and metastasis of neoplastic cell in NPC.</p><p><b>METHODS</b>Twenty-one patients with NPC were studied. The samples of primary tumor and paired lymph node metastatic tumor were collected and examined for aberrant gene promoter methylation in E-cadherin by DNA Methylation-specific polymerase chain reaction (MSP). Reverse transcriptase polymerase chain reaction (RT-PCR), Western blotting and immunohistochemical staining were adopted to detect mRNA and protein levels of E-cadherin and beta-catenin.</p><p><b>RESULTS</b>(1) The gene promoter methylation in E-cadherin was 52.4% (11/21) in primary tumor of NPC, and 80.9% (17/21) in lymph node metastatic tumor, which existed significant difference (P < 0.05). (2) In primary tumor, about 80% (0 approximately 100%) neoplastic cells expressed E-cadherin protein on the average, which was significantly higher than that of metastatic tumor (50% on the average, P = 0.004). The expression levels of beta-catenin protein were high in both primary and metastatic tumors, but with no statistic difference (P = 0.698). (3) By Western blotting analysis, the relative intensity of protein expression in E-cadherin was significantly higher in primary tumor (206.7 +/- 32.7) compared to that of metastatic tumor (65.0 +/- 15.9), while the expression of beta-catenin protein showed no difference between them (P = 0.754). (4) mRNA expression level of E-cadherin was higher in primary tumor than that of metastatic tumor.No remarkable difference was found for the mRNA expression of beta-catenin.</p><p><b>CONCLUSIONS</b>(1) Downregulation of mRNA and protein expression of E-cadherin may play a critical role in neoplastic cell invasion and metastasis in NPC. The aberrant promoter methylation of E-cadherin may ultimately alter the mobility and scattering of tumor cells in NPC. (2) Downregulation of E-cadherin alone may be enough for the tumor cell to lose intercellular adhesions which results in tumor cell invasion and metastasis. However, mutant beta-catenin could also involve in this progress. (3) The detection of gene promoter hypermethylation of E-cadherin should be evaluated in the screening and surveillance of NPC.</p>

Influence of E-cadherin promoter methylation and mutation of beta-catenin on invasion and metastasis of nasopharyngeal carcinoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the mechanism of invasion and metastasis in early nasopharyngeal carcinoma (NPC) in relation to E-cadherin promoter methylation and mutation in exon 3 of beta-catenin.</p><p><b>METHODS</b>Methylation of E-cadherin promoter, mutation in exon 3 of beta-catenin and differential expression of beta-catenin in the primary lesion of 21 NPC and the metastatic lymph node of 21 NPC were investigated by DNA Methylation-Specific PCR, direct sequencing and immunohistochemical method.</p><p><b>RESULTS</b>Methylation on E-cadherin promoter was showed in 23.8% (5/21) primary lesions and 61.9% (13/21) metastatic lymph nodes (P < 0.01). Mutation in exon 3 of beta-catenin was showed in 3 of 42 tissues: codon 37 (TCT-->GCT), codon 41 (ACC-->GCC) and codon 47 (AGT-->ACT). However, there was no relation between these mutations and invasion or metastasis (P > 0.05). High beta-catenin expression on the membrane without nuclear expression was observed in 42 tissues (P > 0.05).</p><p><b>CONCLUSION</b>1. In NPC, methylation of promoter is a major cause of down-regulation of E-cadherin which may finally lead to detachment and metastasis of neoplastic cells, 2. Mutation in exon 3 of beta-catenin is a rare event in NPC. It may be an early event in the carcinogenesis of NPC but have no significant role in invasion and metastasis and 3. High expression of beta-catenin, as one of NPC characteristics, is not a key factor for invasion or metastasis.</p>