Apoptosis and proliferation in subcutaneous panniculitis-like T-cell lymphoma.

Subcutaneous panniculitis-like T cell lymphoma (SPTCL), designated recently as a distinct clinicopathologic entity in the World Health Organization Classification, is a neoplasm composed of cytotoxic T-cells that preferentially involves subcutaneous adipose tissue. Histologically, SPTCL is characterized by extensive karyorrhectic debris and tumor necrosis suggesting that apoptotic mechanisms are involved in its pathogenesis. We assessed the apoptotic index (AI) and proliferation rate (PR) of 13 cases of SPTCL by TUNEL test and Ki-67 immunostaining, respectively. We also immunohistochemically assessed for expression of BCL-2 (anti-apoptosis), BAX (pro-apoptosis), and P53 and correlated the results with apoptosis and proliferation. We detected a high AI (median 8.1%) in 11 cases of SPTCL, and 12 cases had low BCL-2 and high BAX expression. BCL-2 expression inversely correlated with AI (P <.001) and BAX (P <.001). We found a low PR (cutoff > or = 25%) in eight (61%) cases. There was an inverse correlation between AI and PR (r = -.58, P =.04). Ten cases were assessed for P53; immunostaining results were heterogeneous but P53 expression correlated with large cell cytologic features. Our findings demonstrate that SPTCLs have a high AI that may be explained by differential expression of BCL-2 and BAX in the neoplastic cells.     

Telomerase activity significantly correlates with chromosome alterations, cell differentiation, and proliferation in lung adenocarcinomas.

Telomerase activity was examined by the telomeric repeat amplification protocol assay in 25 cases of lung adenocarcinoma, in relation to cancer cell differentiation, proliferation, and chromosome alterations. Telomerase activity, chromosome alterations, and cell proliferation assessed by Ki-67 labeling were significantly lower (P < .001 to .05) in well-differentiated (10 cases) than in moderately differentiated (8 cases) or poorly differentiated (7 cases) lesions. Telomerase activity by semiquantitative analysis with scoring of 0 to 3 was significantly correlated with similarly graded chromosome alterations (P < .05) and Ki-67 labeling indices (P < .002). Telomerase activity and chromosome alteration (T-C) indices generated by multiplication of telomerase activity and chromosome alteration scores also showed a significant correlation with cell differentiation. The Clara cell subtype, confirmed by electron microscopic analysis, significantly predominated in the well-differentiated group, showing a low grade of telomerase activity and chromosome alterations and low Ki-67 labeling indices, suggesting clinical relevance. No significant association of telomerase activity was found with p53 protein accumulation or Bcl-2 protein expression. The good correlation of telomerase activity with chromosome alterations, cell differentiation, and Ki-67 labeling indices suggests that this parameter might have potential application in estimation of prognosis.     

Germinal center and activated b-cell profiles separate Burkitt lymphoma and diffuse large B-cell lymphoma in AIDS and non-AIDS cases

Morphologic features of Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) overlap. No single phenotypic marker or molecular abnormality is pathognomonic. We tested a panel of 8 germinal center (GC) and activated B-cell (ABC) markers for their ability to separate BL and DLBCL. We diagnosed 16 BL and 39 DLBCL cases from 21 patients with AIDS and 34 without AIDS based on traditional morphologic criteria, Ki-67 proliferative index, and c-myc rearrangement (fluorescence in situ hybridization). After immunohistochemically staining tissue microarrays of BL and DLBCL for markers of GC (bcl-6, CD10, cyclin H) and ABC (MUM1, CD138, PAK1, CD44, bcl-2), we scored each case for the percentage of positive cells. Hierarchical clustering yielded 2 major clusters significantly associated with morphologic diagnosis (P < .001). For comparison, we plotted the sum of the GC scores and ABC scores for each case as x and y data points. This revealed a high-GC/low-ABC group and a low-GC/high-ABC group that were associated significantly with morphologic diagnosis (P < .001). Protein expression of multiple GC and ABC markers can separate BL and DLBCL.     

胃肠道类癌中Ki-67、PCNA、Laminin的表达及意义

目的 研究胃肠道类癌Ki-67、PCNA、laminin(LN)的表达与侵袭性和增殖性的关系。方法 应用免疫组织化学S-P法检测36例胃肠道类癌组织中3种指标的表达。结果 36例胃肠道类癌组织中Ki～67、PCNA、LN阳性表达率分别为50．o％、55．5％、55．5％；随肿瘤分化程度降低、浸润深度加深、淋巴结的转移，各指标阳性表达率逐渐升高。结论 Ki-67、PC-NA可作为评估胃肠道类癌预后的指标。Ki-67比PCNA在评价胃肠道类癌增殖性方面更准确；PCNA免疫染色反应性较敏感，其类癌诊断的阳性标准应适当提高。LN的表达可预测胃肠道类癌组织的分化、浸润及转移能力。     

B细胞非霍奇金淋巴瘤PBK/TOPK表达与增殖活性的关系

目的研究PBK／TOPK在反应性淋巴组织增生和B细胞非霍奇金淋巴瘤组织（B cell non—Hodgkin’s lymphoma,B—NHL）中的表达和肿瘤增殖活性的关系,探讨TOPK在淋巴瘤组织中发生发艮中的作用及其临床意义。方法运用SP法免疫组化法检测PBK／TOPK和Ki-67在B细胞性侵袭性淋巴瘤22例、惰性淋巴瘤21例、淋巴结反应性增生15例中的表达。结果TOPK在惰性淋巴瘤中的阳性率明显低于侵袭性淋巴瘤（P〈0．01）。Ki-67在反应性淋巴结增生和B—NHL中的表达与PBK／TOPK非常一致,二者存在正相关（P〈0．01）。在淋巴结反应性增牛中,PBK／TOPK主要表达于激活的中心母细胞,同时这些细胞亦表达Ki-67抗原。结论TOPK能激活B淋巴细胞,并与B—NHL的细胞增殖活性和恶性程度密切相关,提示TOPK在B细胞淋巴瘤的恶性增殖过程中发挥重要作用,为B细胞淋巴瘤的预后削断和诊治提供新的依据和靶点。     

Multiparameter immunohistochemical analysis of the cell cycle proteins cyclin D1, Ki-67, p21WAF1, p27KIP1, and p53 in mantle cell lymphoma

BACKGROUND: Mantle cell lymphoma (MCL) is characterized by overexpression of cyclin D1, a G1 cyclin that participates in the control of cell cycle progression at the G1 to S phase transition. In addition to cyclin D1, other cell cycle regulatory molecules may be involved in the proliferation and progression of MCL. Mutation of p53, deletion of p16(INK4a), and loss of p21(WAF1) expression have been reported in some cases of blastoid MCL. OBJECTIVE: We sought to examine levels of expression of these proteins in typical and blastoid MCL and to determine whether differences were present between these subtypes of lymphomas. DESIGN: A retrospective series of typical and blastoid MCLs was evaluated for expression of the cell cycle-related proteins cyclin D1, p21(WAF1), p27(KIP1), Ki-67, and p53, as well as mitotic index. Paraffin-embedded archival tissues from 24 MCL specimens (17 typical, 7 blastoid) were immunostained with antibodies to p21(WAF1), p27(KIP1), p53, Ki-67, and cyclin D1. The percentage of positive cells for each specimen was estimated by counting 1500 cells under oil immersion microscopy. Levels of antigen expression were compared for the typical and blastoid MCLs. The mitotic index was estimated using twenty 100x oil immersion fields (OIFs) for each specimen. RESULTS: Cyclin D1 expression was seen in 22/24 specimens (92%). Blastoid MCLs were characterized by a significantly higher mean mitotic index (>20 mitoses/20 OIFs) and Ki-67 index (>45%) when compared with typical MCLs (P <.001 and P <.008, respectively; Fisher's exact test). High expression of p27(KIP1) (>25% staining) was seen more frequently in typical MCLs than in the blastoid variants (P =.03; Fisher's exact test). No significant differences were found between typical and blastoid MCLs for the expression of p21(WAF1) or p53. CONCLUSIONS: A significantly higher mitotic index and Ki-67 index were found in blastoid MCLs as compared with typical MCLs. Low p27(KIP1) expression was associated with the blastoid MCL variant. These findings confirm the high proliferative nature of blastoid MCL and suggest a role for p27(KIP1) in the negative regulation of the cell cycle in MCL.     

MUM-1/IRF4在滤泡性淋巴瘤中的表达及意义

目的 检测MUM-1/IRF4在滤泡性淋巴瘤中的表达,并探讨其在滤泡性淋巴瘤中表达的生物学意义.方法 应用组织芯片和免疫组织化学SP法检测98例滤泡性淋巴瘤中MUM-1/IRF4及CD10、bcl-6、bcl-2、Ki-67的表达,对MUM-1/IRF4在不同级别滤泡性淋巴瘤中的表达及与其他几个相关蛋白标志物表达的关系进行统计学分析.结果 (1)MUM-1/IRF4在滤泡性淋巴瘤中的表达率为39.8%(39/98),CD10为62.2%(61/98),bcl-6为80.6%(79/98),bcl-2为87.8%(86/98),Ki-67高表达(≥25%)的阳性率为50.0%(49/98);(2)MUM-1/IRF4主要在高级别滤泡性淋巴瘤中表达,与分级(r=0.628,P=0.000)和Ki-67(r=0.473,P=0.000)的表达呈正相关;(3)MUM-1/IRF4与CD10的表达呈负相关(r=-0.597,P=0.000),与bcl-6和bcl-2的表达无相关性.结论 MUM-1/IRF4在高级别滤泡性淋巴瘤中显著性高表达,MUM-1/IRF4阳性病例肿瘤细胞增殖活性高,提示其进展快,预后差,MUM-1/IRF4强阳性有助于高级别滤泡性淋巴瘤的诊断.

Abstract：

Objective To study the expression of MUM-1/IRF4 and its significance in follicular lymphoma. Methods Ninety-eight cases of follicular lymphoma were enrolled into the study. They were graded according to the 2008 WHO criteria. The expression of MUM-1/IRF4 protein and other markers (CD10, bcl-6, bcl-2 and Ki-67) was studied using tissue microarray and immunohistochemistry. Results Amongst the 98 cases studied, there were 24 grade 1 cases, 30 grade 2 cases, 26 grade 3A cases and 18 were grade 3B cases. The rates of expression of MUM-1/IRF4, CD10, bcl-6, bcl-2 and Ki-67 ( ≥25% )were 39. 8% ( 39/98 ), 62.2% ( 61/98 ), 80. 6% ( 79/98 ), 87. 8% ( 86/98 ) and 50. 0% ( 49/98 ),respectively. MUM-1/IRF4 predominantly expressed in high-grade follicular lymphoma and showed a significantly positive correlation with lymphoma grade ( r = 0. 628, P = 0. 000 ) and Ki-67 index ( r = 0. 473,P = 0.000). MUM-1/IRF4 expression had a significantly negative correlation with CD10 expression (r = -0. 597, P = 0. 000), but no correlation with bcl-6 and bcl-2 expression. Conclusions MUM-1/IRF4 expression is significantly higher in high-grade follicular lymphoma, indicating that these cases have a high proliferative activity, more aggressive behavior and poorer prognosis. MUM-1/IRF4, when strongly expressed, is another helpful marker for the diagnosis of high-grade follicular lymphoma.     

The degree of overlap between the follicular dendritic cell meshwork and tumor cells in mantle cell lymphoma is associated with prognosis

This study concerning mantle cell lymphoma (MCL) investigated retrospectively an association between patient prognosis and the percentage of the total number of lymphoma cells found in the follicular dendritic cell (FDC) meshwork, that is, the degree of overlap of lymphoma cells. Two hundred and nine MCL patients were apportioned to grades I–III, in which the CD21-positive FDC meshwork covered ≤50%, 51%–89%, and ≥90% of the tumor area, respectively. Significant differences among the grades (all, P?<?0.01) were found in the following: duration of disease (from onset of clinical manifestation to diagnosis); clinical staging; extranodal involvement (non-lymphoid organs); histological subtype; and Ki-67 proliferation index (PI). After removing the aggressive variants, the overall survival rates of grade I (n?=?92) and II (n?=?57) patients were similar. The overall survival rates of grade III (n?=?46) patients differed from that of grade I?+?II patients (P?<?0.01). The grades negatively correlated with the Ki-67 PI value (r?=??0.234, P?=?0.001). At each grade the OSR of patients with Ki-67 PI ≤30% was similar to that of patients with Ki-67 >30%. In the Ki-67 PI ≤30% group, the OSRs of the patients differed significantly among the grades. In the Ki-67 >30% group the OSRs of the grades were similar. The results of multivariate Cox regression analysis showed that the degree of overlap, age and Ki-67 PI was the independent prognostic factors of the OSRs of MCL patients. Our data suggests that MCL patients in whom there was a high degree of overlap between the FDC meshwork and tumor area have a better clinical prognosis. The degree of overlap correlates well with the Ki-67 PI, which can be used to predict the prognosis of patients.     

Plasmablastic lymphomas and plasmablastic plasma cell myelomas have nearly identical immunophenotypic profiles.

Plasmablastic lymphoma is an aggressive neoplasm that shares many cytomorphologic and immunophenotypic features with plasmablastic plasma cell myeloma. However, plasmablastic lymphoma is listed in the World Health Organization (WHO) classification as a variant of diffuse large B-cell lymphoma. To characterize the relationship between plasmablastic lymphoma and plasmablastic plasma cell myeloma, we performed immunohistochemistry using a large panel of B-cell and plasma cell markers on nine cases of plasmablastic lymphoma and seven cases of plasmablastic plasma cell myeloma with and without HIV/AIDS. The expression profiles of the tumor suppressor genes p53, p16, and p27, and the presence of Epstein-Barr virus (EBV) and human herpes virus type 8 (HHV-8) were also analyzed. All cases of plasmablastic lymphoma and plasmablastic plasma cell myeloma were positive for MUM1/IRF4, CD138, and CD38, and negative for CD20, corresponding to a plasma cell immunophenotype. PAX-5 and BCL-6 were weakly positive in 2/9 and 1/5 plasmablastic lymphomas, and negative in all plasmablastic plasma cell myelomas. Three markers that are often aberrantly expressed in cases of plasma cell myelomas, CD56, CD4 and CD10, were positive in 5/9, 2/5, and 6/9 plasmablastic lymphomas, and in 3/7, 1/5, and 2/7 plasmablastic plasma cell myelomas. A high Ki-67 proliferation index, overexpression of p53, and loss of expression of p16 and p27 were present in both tumors. No evidence of HHV-8 infection was detected in either neoplasm. The only significant difference between plasmablastic lymphoma and plasma cell myeloma was the presence of EBV-encoded RNA, which was positive in all plasmablastic lymphoma cases tested and negative in all plasma cell myelomas. In conclusion, most cases of AIDS-related plasmablastic lymphoma have an immunophenotype and tumor suppressor gene expression profile virtually identical to plasmablastic plasma cell myeloma, and unlike diffuse large B-cell lymphoma. These results do not support the suggestion in the WHO classification that plasmablastic lymphoma is a variant of diffuse large B-cell lymphoma.     

Immunohistochemical analyses of β-catenin and cyclin D1 expression in giant cell tumor of bone (GCTB): A possible role of Wnt pathway in GCTB tumorigenesis

Giant cell tumor of bone (GCTB) is a benign neoplasm but occasionally shows local recurrence, and histologically consists of osteoclast-like giant cells (GC) and stromal mononuclear cells (SC), which are capable of proliferation and osteoblastic differentiation. Activation of Wnt signaling can induce osteoblast differentiation and osteoclastgenesis during bone resorption process. This study analyzed the profiles of β-catenin and cyclin D1 expression in GCTB to elucidate an involvement of Wnt pathway in tumorigenesis. We performed immunohistochemistry for β-catenin, cyclin D1, and Ki-67 in 16 GCTB tumors, including 5 recurrent cases that were surgically resected. All 16 cases of GCTB displayed β-catenin, cyclin D1, and Ki-67 expression. Immunoreactivity for β-catenin was observed in nuclei of SC and GC. Cyclin D1 immunoreactivity was found mainly in nuclei of GC, while Ki-67 immunoreactivity was restricted to nuclei of SC. The nuclear β-catenin labeling index (LI) in both SC (60.6 vs. 41.8%, p=0.074) and GC (41.7 vs. 20.1%, p=0.095) was higher in recurrent tumors than in primary tumors in all the 4 cases. However, Ki-67 LI in SC (18.8 vs. 19.9%, p=0.851) and cyclin D1 LI in GC (55.4 vs. 70.1%, p=0.225) were not higher in recurrent tumors than in primary tumors. Our results suggested activation of Wnt/ β-catenin pathway in GCTB tumorigenesis. Since cyclin D1 in GC was never associated with the expression of the well-known proliferative marker Ki-67, cyclin D1 expression might play a role in GC formation instead of promoting cell proliferation during GCTB tumorigenesis. Importantly, it was suggested that the nuclear β-catenin staining level might be associated with tumor recurrence in GCTB.     

The relationship between the gene mutation of p53 and the protein expression of p53 and Ki-67 in non-Hodgkin's lymphomas

The relationship between the mutation of the p53 gene and the expression of the p53 protein and the Ki-67 antigen has been investigated in 115 cases with non-Hodgkin's lymphoma, using the immunohistochemical double staining technique, single-strand conformational polymorphism and DNA sequencing methods. Eighteen cases showed more than 10% of p53+ cells and the others showed a few p53+ cells presented sporadically. Alterations in the p53 gene were detected in six cases with B cell type, consisting of five cases with point mutation and one case with point mutation and 15 base pairs deletion. These six cases showed a high percentage of p53+ cells and five cases revealed that the percentage of p53+ cells was higher than that of Ki-67+ cells (p53+ cells > Ki-67+ cells). Excluding the six cases with mutation of the p53 gene, all cases revealed that the percentage of p53+ cells was less than that of Ki-67+ cells (p53+ cells < Ki-67+ cells). Moreover, there was a positive correlation between expression of the p53 protein and of the Ki-67 antigen in histologic types of B cell lymphomas and of T cell lymphomas, respectively, except in small non-cleaved (Burkitt's) and lymphoblastic types. Therefore, sporadic cases showing p53+ cells > Ki-67+ cells revealed alteration of the p53 gene, and expressed abnormal p53 protein (mutant form). Most cases showing p53+ cells < Ki-67+ cells expressed normal p53 protein (wild type), and may reflect the rapid proliferation rate.     

Significance of Ki-67 and p53 immunoexpression in the differential diagnosis of oral necrotizing sialometaplasia and squamous cell carcinoma

Necrotizing sialometaplasia (NS) is a benign condition that usually involves the hard palate and can be mistaken for invasive squamous cell carcinoma (SCC). In this study, we have demonstrated that p53 and Ki-67 staining may assist in the differential diagnosis of NS from SCC. Thirteen cases of NS and 20 cases of oral cavity SCC were randomly selected from our surgical pathology archive from 1992 to 2009. Each case was additionally stained with Ki-67, p53, BCL-2, p16, and epidermal growth factor receptor (EGFR) antibodies. All 13 cases of NS were negatively stained for BCL-2, EGFR, and Ki-67. Three cases (23%) showed weak and focal positive nuclear staining for p53. Two cases (15%) showed positive staining for p16. In 16 well-differentiated SCC cases, p53 was positive in 12 cases (75%); BCL-2, p16, EGFR were positive in 3 cases (18%); and Ki-67 was positive in all cases (100%). In 4 moderately differentiated SCC cases, p53 expression was positive in all cases. Two tumors (50%) had a positive expression of BCL-2. Three cases (75%) had a positive p16 staining, and 1 (25%) had a positive EGFR staining. All cases were positive with high nuclear staining greater than 35% of cells for Ki-67. Ki-67 and p53 showed more intense staining and increased in moderately differentiated SCC comparing with well-differentiated SCC and NS. BCL-2, EGFR, and p16 had the same pattern of staining with the same extent in NS and SCCs. The diagnosis of NS may be difficult and may be supplemented via immunohistochemistry by demonstrating focal or absent p53, low to absent Ki-67 (<10% of cells). Although Ki-67 and p53 staining are generally more intense and are increased in malignancy, these findings may be helpful adjuncts in the differential diagnosis of NS from SCC in appropriate clinical setting.     

Determination of the growth fraction in cell suspensions by flow cytometry using the monoclonal antibody Ki-67

A novel procedure for determining the growth fraction of cell suspensions by flow cytometry is described. This method identifies proliferating cells by binding the monoclonal antibody Ki-67 to a nuclear antigen present in all cells that are in the G1, S, G2, and M phase of the cell cycle, but not in the G0 phase. In a kinetic study of Na cell line U937 using concanavalin A for stimulation of peripheral blood mononuclear cells, a steady increase of Ki-67 positive cells evaluated by flow cytometry was observed. Simultaneously, the [3H]thymidine uptake of the ConA blasts was measured and compared to the expression of Ki-67. A linear correlation between the percentage of Ki-67 positive cells and the log transformed counts per minute was demonstrated, and staining with Ki-67 detected cell proliferation with the same sensitivity as 3H-TdR uptake. In addition, it was possible to stain Ki-67-labelled cells with a second cell marker if a second fluorescent dye coupled to an antibody was used. This provided the opportunity to define precisely the phenotype of proliferating cells. Conversely, the number of proliferating cells expressing certain preselected surface markers could be easily determined.     

Detection of telomerase activity in psoriasis lesional skin and correlation with Ki-67 expression and suppression by retinoic acid

Telomerase activity is usually detected in most tumor tissues but not in normal tissues. Recently, there is increasing evidence that telomerase activity is associated with cell proliferation without malignancy, whereas there is little information about telomerase activity and its relationship with cell proliferation in chronic hyperproliferative skin diseases. Thus, we studied telomerase activity in skins from 10 patients with psoriasis and compared telomerase activity with the expression of Ki-67, a proliferation marker, using immunohistochemical staining. The effect of retinoic acid on the telomerase activity in HaCaT cells was also evaluated. Telomerase activity was detected in 7 (70%) of 10 lesional skins of psoriasis and none of the nonlesional skin. Telomerase activity in lesional skin was significantly associated with Ki-67 labelling index. Retinoic acid treatment on HaCaT cells inhibited telomerase activity, which correlated with inhibition of cell proliferation by the agent. The results of our study represent another example that shows telomerase activity correlates with cellular proliferation. Further studies on the regulation of the telomerase are needed to understand the cellular factors involved in controlling telomerase activity.     

Expression of cyclin D1, Ki-67 and PCNA in non-small cell lung cancer: prognostic significance and comparison with p53 and bcl-2

Uncontrolled cell proliferation is the hallmark of malignant tumours. Thus, the proliferative potential of tumour cells is an important prognostic factor. However, evaluation of the prognostic significance of the expression of proteins involved in regulation of cell proliferation remains controversial. In the present study, expression of Ki-67, PCNA and cyclin D1 was estimated in a group of 89 surgically resected non-small cell lung carcinomas using immunohistochemistry. The results were compared with expression of bcl-2 and p53 and with clinicopathological parameters including patients' survival. Ki-67 and PCNA were found to be moderately and highly expressed in 39% and 44% of the tumours, respectively. There was a strong correlation between Ki67 and PCNA expression. Forty five of 88 tumours (51%) showed overexpression of cyclin D1. Surprisingly, cyclin D1 was mainly localized in the cytoplasm and only a small group of tumours (9/88, 10%) showed nuclear staining as well. Bcl-2 and p53 expression was observed in 69% and 30% of the tumours, respectively. All these markers were found to be independent of clinicopathological parameters, except for Ki-67 and bcl-2 expression, which was associated with squamous cell carcinomas. It is concluded that none of the markers that were studied can be used as an independent prognostic factor, whereas the following combinations of markers may have favourable prognostic value: p53 positivity and low Ki-67 expression, p53 positivity and lack of cyclin D1 expression, bcl-2 positivity and low Ki-67 expression, and lack of cyclin D1 expression and low Ki-67 expression.     

Telomerase activity in melanocytic lesions: A potential marker of tumor biology

Telomerase activation, being a cardinal requirement for immortalization, is a crucial step in the development of malignancy. With a view toward diagnostic and biological aspects in melanocytic neoplasia, we investigated the relative levels of telomerase activity in 72 nevi and 16 malignant melanomas by means of a modified telomeric repeat amplification protocol (TRAP) assay, including an internal amplification standard. We further compared telomerase activity with the expression of two different proliferation-specific proteins, Ki-67 and repp86, a protein expressed exclusively in the cell cycle phases S, G2, and M. Telomerase activity was associated with the overall growth fraction (Ki-67) but showed a closer correlation with the expression of repp86. Both telomerase activity and proliferation indices discriminated clearly between malignant melanomas and nevi, but not between common and dysplastic nevi. Nonetheless, a portion of nevi exhibited markedly elevated telomerase activity levels without proportionally increased proliferation. This was independent of discernible morphological changes. Clinicopathological correlations showed an association between high telomerase activity and early metastatic spread in melanomas, linking telomerase to tumor biology. Our results provide arguments in favor of an occasional progression from nevi to melanomas and imply that proliferation measurements in combination with telomerase assays may help to elicit early malignant transformation that is undetectable by conventional morphology.     

脱落酸抑制人肝癌细胞增殖

目的探讨脱落酸抑制SMMC-7721人肝癌细胞增殖作用的机制。方法免疫细胞化学检测P53、Ki-67、Cyclin D1蛋白表达;RT-PCR检测P53和端粒酶mRNA表达。结果经脱落酸(ABA)、环六亚甲基二乙酰胺(HMBA)和ABA HMBA作用后细胞内mtP53、Cyclin D1、Ki-67及细胞内mt P53、hTERT mRNA表达水平均明显降低(P<0.05)。结论ABA抑制SMMC-7721人肝癌细胞增殖,其作用机制可能是调控细胞周期,降低mtP53、Ki-67、Cyclin D1蛋白及mtP53,hTERT mRNA表达。     

Proliferative fraction, bcl-1 gene translocation, and p53 mutation status as markers in mantle cell lymphoma

The molecular genetic hallmark of mantle cell lymphomas (MCL) is the reciprocal translocation t(11;14)(q13;q32) which juxtaposes the bcl-1 proto-oncogene to one of the joining segments of the immunoglobulin heavy chain gene. This translocation is very common in MCL and occurs in up to 70% of these malignancies. Due to the aggressive nature of MCL, markers identifying tumor progression and clinical outcomes are necessary. In this study we examined whether a corroborative relation exists between p53 mutations, bcl-1 translocation, and the proliferative fraction in MCL. We evaluated the proliferative fraction, p53 gene status, and bcl-1 translocation in 21 patients with confirmed MCL. Controls consisted of normal DNA and 7 B-cell lymphomas. Immunohistochemical detection of Ki-67 was used to assess proliferative activity while molecular techniques were used to detect p53 mutations and the bcl-1 gene translocation. Reactivity to the monoclonal antibody Ki-67 on neoplastic cells ranged from 5% to 40% in typical MCL cases. The bcl-1 gene translocation was detected by PCR in 48% (10/21) of MCLs while no rearrangements were detected by PCR in case control DNA. Screening exons 5-8 of the p53 gene for mutations did not identify a single mutation in any of the MCL cases. No correlation was found between p53 mutations, the presence of a bcl-1 translocation, and the proliferative activity of neoplastic MCL cells. We conclude that these markers may demonstrate independent events which occur during the pathogenesis of MCL.