Bax/bcl-2: cellular modulator of apoptosis in feline skin and basal cell tumours

Bcl-2 and bax are two members of the BCL-2 gene family that play a prominent role in the regulation of apoptosis. Bax and bcl-2 expression were examined immunohistochemically in normal (healthy) feline skin and in 24 benign feline cutaneous basal cell tumours. The tumours were also examined for cellular proliferation by measurement of reactivity for the proliferation marker Ki-67, and for apoptosis by in-situ labelling for fragmented DNA. Bcl-2 was detected in normal basal epithelium and in 23 of 24 basal cell tumours. Bax was detected in both basal and suprabasal epithelium, but in only seven of 24 tumours. For tumours that expressed both bax and bcl-2, the bax:bcl-2 ratio was low. Neither bax nor bcl-2 expression was detected in 14 feline cutaneous squamous cell carcinomas. Basal cell tumours showed modest cellular proliferation (median, 17.5% Ki-67- reactive cells), but few (less than 1%) apoptotic cells. The slow, indolent growth of feline cutaneous basal cells in these benign skin tumours may be a response, at least in part, to opposing regulatory expressions of bcl-2 and bax. Copyright Harcourt Publishers Ltd.     

Comparative Analysis of Cells with Combined Apoptosis and Proliferation Markers in Thyroid Tissue Specimens from Patients with Cancer,Adenoma, and Autoimmune Diseases

Combined phenotypes of cells with membrane and intracellular expression of apoptosis and proliferation regulation markers (p53, bcl-2, CD95, CD95L, Ki-67) were studied by flow cytometry of cell suspension from thyroid tissue specimens from patients with autoimmune diseases, adenoma, and thyroid cancer. The incidence of cell groups with phenotypes p53/Ki-67, p53/CD95, bcl-2/Ki-67, bcl-2/CD95, CD95/Ki-67, p53/CD95L, CD95/CD95L, and bcl-2/CD95L was evaluated and the density of receptor distribution on/in each cell group are presented. Patients with autoimmune diseases had high incidence of cells with phenotypes p53/Ki-67, p53/CD95, bcl-2/Ki-67, bcl-2/CD95, CD95/Ki-67, p53/CD95L, CD95/CD95L, and bcl-2/CD95L; cells with the bcl-2/CD95 phenotype were the most incident. Patients with thyroid adenoma had high levels of cells with p53/CD95L phenotype, while patients with thyroid cancer had significantly lower levels of p53 expression in the p53/CD95L cell group. The density of CD95L receptors on CD95/CD95L-positive cells was 4-7-fold higher in patients with thyroid tumors; the density of CD95L receptors on CD95/CD95L cells was maximum in thyroid adenoma and minimum in thyroid cancer. These data indicate differences in the expression of apoptosis and proliferation markers in thyroid adenoma, cancer, and autoimmune diseases. Analysis of the expression of these markers in the above diseases can be useful for differential diagnosis.     

Apoptosis regulation differs between ulcerative colitis-associated and sporadic colonic tumors. Association with survivin and bcl-2

To clarify kinetics in ulcerative colitis (UC)-associated lesions, cell proliferation, apoptosis, and expression of apoptosis-inhibitory proteins were studied. Ki-67 labeling and survivin and bcl-2 expression were examined immunohistochemically in 22 low-grade dysplasias (LGDs), 25 high-grade dysplasias (HGDs), and 13 adenocarcinomas associated with UC, and for comparison in 21 sporadic adenomas with LGD, 22 sporadic adenomas with HGD, and 21 invasive adenocarcinomas. Apoptosis was studied with nick-end labeling and immunohistochemical analysis of single-stranded DNA. In UC-associated LGDs, Ki-67--positive cells were more frequent in the lower than the upper half of the crypt, related to bcl-2 expression, while in sporadic adenomas such cells were more common in the upper half. No difference in apoptosis was found between UC-associated LGDs and sporadic adenomas with LGD or between UC-associated HGDs and sporadic adenomas with HGD. However, UC-associated carcinomas exhibited a lower apoptotic count than their sporadic invasive counterparts. This seemed related to higher survivin expression without a significant difference between the 2 types of invasive lesions regarding bcl-2 levels. Apoptosis is less frequent in UC-associated than in sporadic invasive colon carcinomas, this being linked to elevated survivin expression. The control of apoptosis may be different in the 2 types of tumorigenesis.     

Estimation of apoptosis and cell proliferation in histiocytic necrotizing lymphadenitis using immunohistochemical double staining

The aim of the present study was to estimate the relationship between apoptosis and cell proliferation in histiocytic necrotizing lymphadenitis (HNL). Fifteen patients with HNL were retrospectively analyzed. The patients were divided into three groups according to the proportion of the necrotic area as follows: necrosis (+), necrotic area <25%; necrosis (++), necrotic area 25–50%; and necrosis (+++), necrotic area >50%. Immunohistochemical double staining was performed for CD3 plus caspase-3 and for Ki-67 plus caspase-3 and positive cells were counted in two areas: one without and one with obvious apoptotic features. Most caspase-3-positive cells were also stained for CD3 (area exhibiting obvious apoptotic features: average, 92.3%). Furthermore, various proportions of both Ki-67- and caspase-3-positive cells were detected in all the groups (range, 5–70%). In the area with obvious apoptotic changes, the average percentage of both Ki-67- and caspase-3-positive cells (38.6%) was higher than that in the area without obvious apoptotic features (16.3%). A proportion of cells in HNL undergo proliferation and apoptosis simultaneously, such as neoplastic cells, thereby exhibiting rapid cell cycles.     

Immunohistochemical analysis of cleaved caspase-3 detects high level of apoptosis frequently in diffuse large B-cell lymphomas of the central nervous system

The purpose of the present paper was to examine the level of apoptosis and the relationships among apoptosis, apoptosis-associated proteins, and proliferating potential in lymphoma tissues to clarify the characteristics of apoptosis in diffuse large B-cell lymphomas (DLBCL) of the central nervous system (CNS). The formalin-fixed, paraffin-embedded tissues of CNS and non-CNS DLBCL (20 cases each) were studied by terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) and immunohistochemistry, using antibodies against single-stranded DNA (ssDNA), cleaved caspase-3, bcl-2, bax, p53, Fas and Ki-67. The cleaved caspase-3 immunohistochemistry detected apoptosis of the lymphoma cells most sensitively compared to TUNEL and ssDNA immunohistochemistry. High expression (grade + + or + + +) of cleaved caspase-3 was found more frequently in CNS DLBCL (11 cases, 55%) than non-CNS DLBCL (three cases, 15%; P = 0.009). Bax-positivity of lymphoma cells was increased in six cases of CNS DLBCL, which also showed high positivity of cleaved caspase-3. There was no significant correlation between the cleaved caspase-3-positivity and the Ki-67 positivity. The present study indicates that the number of apoptotic cells and expression level of cleaved caspase-3 were significantly higher in CNS DLBCL than non-CNS DLBCL, and that the correlation of bax and cleaved caspase-3 expression was often present in CNS DLBCL.     

白藜芦醇诱导KG-1细胞凋亡作用机制的初步研究

通过观察白藜芦醇诱导人急性白血病细胞株KG-1凋亡的作用,检测bcl-2、caspase-3的表达,探讨白藜芦醇诱导白血病细胞凋亡的作用机制。采用噻唑蓝(MTT)比色法分析细胞生长状态;瑞-吉染色、透射电镜观察KG-1细胞凋亡的形态学变化;流式细胞术(FCM)测定细胞凋亡与周期分布;半定量RT-PCR检测bcl-2 mRNA、caspase-3 mRNA表达水平。结果显示白藜芦醇可明显抑制KG-1细胞增殖(P<0.01),与对照组相比,实验组使细胞发生S期阻滞(P<0.01),促进细胞凋亡(P<0.01),使bcl-2的表达下调,上调caspase-3的表达(P<0.05)。结论:白藜芦醇能诱导KG-1细胞凋亡,其机制可能与下调bcl-2、上调caspase-3表达水平有关。     

Expression of bcl-2, Ki-67 and p-53 in uveal melanomas

AIM: To investigate expression of proliferative markers bcl-2, Ki-67 and p-53 immunocomplexes in uveal melanoma cells; and to establish whether the intensity of expression correlates with the pathological level of invasion (pT), which would result in prognostic significance. METHODS: Thirty cases of primary uveal melanomas of two different levels of invasion (pT2 and pT3); indirect PAP immunoenzyme method and three step ABC/AP method. The intensity of the reaction was evaluated by a semiquantitative method as negative (-), weakly positive (+), modestly positive (++) and strongly positive (+++). Results were statistically analyzed by Fisher exact test for small examples. RESULTS: The reactivity of Ki-67 and p-53 protein was markedly stronger than bcl-2 in pT2 and pT3 stages. p-53 protein expression showed similar distribution for Ki-67 protein according to pT stages. CONCLUSION: The reactivity of all three markers was stronger in pT3 stage, especially of proliferation markers Ki-67 and p-53. In addition to the fact that they both are reliable indicators of the metastatic potential, Ki-67 is a better marker because there is a well established technique for measuring cell proliferation in all phases of the cell cycle.     

慢病毒介导的caspase-3沉默对大鼠骨髓间充质干细胞增殖和凋亡的影响

 目的：探讨沉默caspase-3对大鼠骨髓间充质干细胞（MSCs）增殖、细胞周期和凋亡的影响。方法：构建靶向caspase-3的shRNA重组慢病毒并转染MSCs,通过real-time PCR和Western blotting 在mRNA及蛋白水平鉴定转染结果。采用MTS法检测细胞增殖,流式细胞术检测细胞周期。Real-time PCR检测bcl-2和bax mRNA的表达。Hoechst荧光染色法检测细胞的凋亡情况。结果：Real-time PCR和Western blotting结果均表明成功建立稳定转染shRNA-caspase-3的大鼠MSCs细胞株。沉默caspase-3使MSCs的增殖率明显提高（P＜0.05）,且S期细胞百分比明显增多,为（52.66±0.30）%。沉默caspase-3后bcl-2 mRNA表达上调,bax mRNA表达下调,bcl-2/bax比值升高（P＜0.05）。转染组的细胞凋亡率为（15.01±1.73）%,低于空载体组的（25.67±3.05）%和空白对照组的（23.67±1.16）%（P＜0.05）。结论: 沉默caspase-3能调控MSCs的细胞周期,促进细胞增殖,减少细胞凋亡。     

Apoptosis occurs independently of bcl-2 and p53 over-expression in non-small cell lung carcinoma

Certain oncogenes and tumour suppressor genes are known to modulate apoptosis. To investigate whether over-expressed bcl-2 and abnormally stabilized p53 are associated with reduced apoptosis in paraffin sections of non-small cell lung carcinoma, apoptotic, mitotic, and Ki-67 labelling indices were determined and correlated with bcl-2 and p53 immunoreactivity in 54 squamous cell carcinomas and 22 adenocarcinomas. Nineteen squamous cell carcinomas (35.2%) showed over-expression of bcl-2, but all 22 adenocarcinomas were bcl-2 negative. Thirty-seven squamous cell carcinomas (68.5%) and 13 adenocarcinomas (59.1%) showed p53 over-expression. Apoptotic tumour cells were identified among p53 positive and bcl-2 positive tumour cells. There was a significant linear correlation between apoptotic indices and mitotic indices. bcl-2 over-expression and p53 over-expression were not associated with attenuated apoptosis, or altered mitotic or Ki-67 labelling indices in either tumour type. Neither bcl-2 nor p53 was of prognostic significance. These results suggest that apoptosis in non-small cell lung carcinoma occurs independently, and is not modulated primarily by, bcl-2 or p53. It is likely that the effects on apoptosis of bcl-2 and p53 are countered by those of other oncogene products and/or additional factors that regulate apoptosis in vivo     

Proliferation and apoptosis in normal bitch mammary tissues in relation to progesterone level

The objective of this study was to investigate the proliferating activity and apoptosis in canine normal mammary tissues in different cycle stages. Mammary tissues were collected from five beagle bitches at six different estrous stages: anestrus, proestrus, estrus, early diestrus, mid diestrus, and late diestrus. The expression of Ki-67 protein and apoptotic bodies was evaluated by avidin–biotin–peroxidase complex (ABC) method and TUNEL assay, respectively. Percentage of Ki-67 positive cells and apoptotic bodies was calculated. The significant highest percentage of Ki-67 positive cells and apoptotic bodies was observed at mid diestrus. Positive correlation was found mainly in the alveolar epithelium between progesterone levels and percentage of Ki-67 positive cells, as well as between progesterone levels and apoptosis. In conclusion, the results from the present study suggested that progesterone may influence on proliferation and apoptosis in canine mammary tissue.     

Immunohistochemical analysis of bcl-2 and p53 expression in breast carcinomas: their correlation with Ki-67 growth fraction

We examined 59 breast cancers for p53 and bcl-2 protein expression by immunohistochemistry. The results were correlated with Ki-67 immunostaining. p53-negativity was noted in 40 cases and the remaining 19 tumours were p53-positive. Thirty-six tumours showed strong expression of bcl-2 and in 23 no staining for this protein was observed. We found statistically significant reverse correlation between expression of p53 and bcl-2 in majority of carcinomas: 31 cases were bcl-2 positive and p53-negative, and 14 tumours were bcl-2-negative and p53-positive. Six carcinomas showed no nuclear staining for Ki-67 and in the remaining 53 the percent of cancer cells positive for Ki-67 ranged from 1 to 60 (mean: 14.6). In these 53 cases we found that bcl-2-positive tumours were characterized by lower proliferation than bcl-2-negative tumours, the mean value of Ki-67 immunostaining being 10.7% and 23.0%, respectively. p53-negative tumours showed lower proliferation than p53-positive tumours: mean Ki-67 index was 10.2% and 23.9%, respectively.We conclude that immunohistochemically detected p53 and bcl-2 proteins show a significant inverse relationship in majority of breast carcinomas and their expression correlates with tumour proliferation (Ki-67 immunostaining).     

DNA replication regulation protein Mcm7 as a marker of proliferation in prostate cancer

BACKGROUND: Recent studies have shown that minichromosome maintenance (MCM) proteins (Mcm2-7) may be useful proliferation markers in dysplasia and cancer in various tissues. AIMS: To investigate the use of Mcm7 as a proliferation marker in 79 lymph node negative prostate cancers and compare it with Ki-67, a commonly used cell proliferation marker. METHODS: The percentage of proliferating cells (proliferation index; PI) was calculated for basal and luminal epithelial cells in benign prostate tissue, prostatic intraepithelial neoplasia (PIN), and epithelial cells in adenocarcinoma. The PI for each biomarker was correlated with the preoperative prostate specific antigen concentration, the Gleason score, surgical resection margin status, and the AJCC pT stage for each patient. RESULTS: The mean PIs for Ki-67 and Mcm7 were: benign luminal epithelium 0.7 and 1.2 and benign basal epithelium 0.8 and 8.2; PIN non-basal epithelium 4.9 and 10.6 and PIN basal epithelium 0.7 and 3.1; adenocarcinoma 9.8 and 22.7, respectively. Mcm7 had a significantly higher mean PI (p<0.0001) than Ki-67 for all cell categories except benign luminal epithelial cells. Mcm7 was a better discriminatory marker of proliferation between benign epithelium, PIN, and invasive adenocarcinoma (p<0.0001) than Ki-67. The drop in Mcm7 mean basal cell PI from benign epithelium to PIN epithelium was significantly larger than for Ki-67 (p<0.0001). Mcm7 had a significantly higher PI than Ki-67 at each risk level. CONCLUSION: Mcm7 may be a useful proliferation marker in prostatic neoplasia and warrants further evaluation as a complementary tool in the diagnosis of PIN and prostate carcinoma.     

Extrinsic and intrinsic pathways of apoptosis in aseptic loosening after total hip replacement

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to identify various apoptosis-related pathways in the cellular response to wear debris. Fas receptor, BAK and caspase-3 cleaved were evaluated immunohistochemically in capsules and interface membranes from patients with aseptic hip implant loosening. Moreover, we investigated local cellular proliferation, documented by the presence of Ki-67, to evaluate the proportion of apoptosis in relation to the proliferation in the different cells. We detected a strong expression of caspase-3 cleaved, Fas and BAK in macrophages, giant cells and T-lymphocytes. The fibroblasts showed caspase-3 cleaved and BAK, but no Fas staining. Demonstrated by Ki-67 staining, we found increased proliferation of macrophages and fibroblasts. Statistical analysis showed a significant positive correlation (p<0.001) between the above mentioned results and the presence of wear debris. The intensity of apoptosis and proliferation differed, depending on the extent of osteolysis. Overall, four different patterns of immunoreactivity were identified. We think, however, that in particle-induced osteolysis apoptosis is pathologically increased - a phenomenon also seen in other diseases. In these instances, the number and degree of apoptotic reactions are so great that the resulting cell remains cannot be completely removed. This leads to an increased excretion of fibrogenic mediators that could be responsible for increased proliferation of fibroblasts in spite of the increased apoptosis. Moreover, it leads to an increased excretion of cytokines which could be responsible for the activation of osteoclasts.     

过表达miR-138抑制TCF-4对甲状腺癌细胞CAL-62增殖，凋亡和运动的调节作用

目的　探究过表达miR-138抑制T细胞因子4（TCF-4）对甲状腺癌细胞CAL-62增殖,凋亡和运动的调节作用机制。 方法　转染miR-138 mimic于CAL-62细胞,使用RT-PCR检测miR-138的表达;使用TCF-4构建pcDNA过表达载体转染CAL-62细胞,使用Westen blot检测TCF-4、增殖核抗原67（Ki67）、增殖细胞核抗原（PCNA）、半胱天冬酶3（caspase-3）、半胱天冬酶9（caspase-9）、上皮型钙黏蛋白（E-cadherin）、波形蛋白（Vimentin）和靶基因cycD、c-Myc的表达;使用EDU染色检测细胞增殖;使用Hoechst染色检测细胞凋亡情况;transwell检测细胞侵袭能力。 结果　相比空白组,miR-138转染+TCF-4组caspase-3、caspase-9、Vimentin蛋白表达显著减少,且有显著性差异（P<0.01）;Ki67、PCNA、E-cadherin、cycD、c-Myc蛋白表达显著增加（P<0.01）;甲状腺肿瘤细胞凋亡受到显著抑制（P<0.01）,增殖、侵染受到显著的促进（P<0.01）。相比TCF-4组,miR-138转染+TCF-4组caspase-3、caspase-9、Vimentin蛋白表达显著增加、（P<0.01）;Ki67、PCNA、E-cadherin、cycD、c-Myc蛋白表达显著减少（P<0.01）,抑制了甲状腺肿瘤细胞增殖、侵染（P＜0.01）,凋亡受到了显著的促进（P<0.01）。 结论　表达miR-138抑制TCF-4使得甲状腺癌细胞CAL-62的增殖、侵染受到显著抑制,凋亡受到显著促进。     

过表达miR-138抑制TCF-4对甲状腺癌细胞CAL-62增殖，凋亡和运动的调节作用

目的　探究过表达miR-138抑制T细胞因子4（TCF-4）对甲状腺癌细胞CAL-62增殖,凋亡和运动的调节作用机制。 方法　转染miR-138 mimic于CAL-62细胞,使用RT-PCR检测miR-138的表达;使用TCF-4构建pcDNA过表达载体转染CAL-62细胞,使用Westen blot检测TCF-4、增殖核抗原67（Ki67）、增殖细胞核抗原（PCNA）、半胱天冬酶3（caspase-3）、半胱天冬酶9（caspase-9）、上皮型钙黏蛋白（E-cadherin）、波形蛋白（Vimentin）和靶基因cycD、c-Myc的表达;使用EDU染色检测细胞增殖;使用Hoechst染色检测细胞凋亡情况;transwell检测细胞侵袭能力。 结果　相比空白组,miR-138转染+TCF-4组caspase-3、caspase-9、Vimentin蛋白表达显著减少,且有显著性差异（P<0.01）;Ki67、PCNA、E-cadherin、cycD、c-Myc蛋白表达显著增加（P<0.01）;甲状腺肿瘤细胞凋亡受到显著抑制（P<0.01）,增殖、侵染受到显著的促进（P<0.01）。相比TCF-4组,miR-138转染+TCF-4组caspase-3、caspase-9、Vimentin蛋白表达显著增加、（P<0.01）;Ki67、PCNA、E-cadherin、cycD、c-Myc蛋白表达显著减少（P<0.01）,抑制了甲状腺肿瘤细胞增殖、侵染（P＜0.01）,凋亡受到了显著的促进（P<0.01）。 结论　表达miR-138抑制TCF-4使得甲状腺癌细胞CAL-62的增殖、侵染受到显著抑制,凋亡受到显著促进。     

异氟醚对膀胱癌 5637 细胞恶性生物学行为及化疗敏感性的影响

目的 探究异氟醚对膀胱癌 5637 细胞恶性生物学行为及化疗敏感性的影响。 方法 单独或联合 给予异氟醚及顺铂处理膀胱癌 5637 细胞, 将细胞随机分为 4 组: 对照组、 异氟醚组、 顺铂组和异氟醚 + 顺 铂联合处理组。 BrdU 染色检测 BrdU 阳性细胞数; 流式细胞仪检测细胞凋亡率和细胞周期分布; Transwell 检测侵袭细胞数; 划痕愈合实验检测划痕愈合率; Western 印迹检测 Ki67、 PCNA、 Bax、 Bcl-2、 cleaved caspase-3 和 caspase-3 蛋白表达; 结果 与顺铂组相比较, 异氟醚 + 顺铂联合处理组 BrdU 阳性细胞数和 Ki67、 PCNA 蛋白表达降低, G0 / G1期比率和 S 期细胞数降低, G2 / M 期比率升高, 细胞凋亡率和 Bax / Bcl-2、 cleaved caspase-3 / caspase-3 比值升高, 侵袭细胞数、 划痕愈合率降低, 均有显著性差异 (P< 0. 05)。 结论 异氟醚可通过抑制细胞增殖、 侵袭、 迁移, 诱导细胞凋亡, 提高 5637 细胞对顺铂的敏感性。     

miR-26b-5p通过抑制REST表达调节胶质瘤细胞生长和侵袭

目的探究miR-26b-5p通过抑制抑制元素1-沉默转录因子(repressor element 1-silencing transcrip-tion factor,REST)表达调节胶质瘤细胞生长和侵袭情况.方法逆转录-聚合酶链反应检测miR-26b-5p和REST表达水平;荧光素酶报告实验检测miR-26b-5p和REST的靶向关系;Hoechst染色检测细胞凋亡;Colony形成法检测细胞增殖;Transwell检测细胞侵袭;蛋白免疫印迹检测细胞Ki67、MMP-9、cleaved caspase-3蛋白表达水平.结果miR-26b-5p和REST存在直接靶向作用关系,与Control组比较,mimic组细胞增殖数、侵袭数和Ki67、MMP-9表达明显降低,凋亡率与cleaved caspase-3表达明显升高,inhibitor组细胞增殖数、侵袭数和Ki67、MMP-9表达明显升高,凋亡率与cleaved caspase-3表达明显降低.结论miR-26b-5p可以通过抑制对REST的表达调节胶质瘤细胞生长、侵袭、凋亡能力.     

Protection of the Peyer's patch-associated crypt and villus epithelium against methotrexate-induced damage is based on its distinct regulation of proliferation

The crypt and villus epithelium associated with Peyer's patches (PPs) is largely spared from methotrexate (MTX)-induced damage, compared with the non-patch (NP) epithelium. To assess the mechanism(s) preventing damage to the PP epithelium after MTX treatment, epithelial proliferation, apoptosis, and cell functions were studied in a rat-MTX model. Small intestinal segments containing PPs were excised after MTX treatment. Epithelial proliferation and apoptosis were assessed by detection of incorporated BrdU and cleaved caspase-3, respectively. Epithelial functions were determined by the expression of cell type-specific gene products at mRNA and protein level. Before and after MTX treatment, the number of BrdU-positive cells was higher in PP crypts than in NP crypts. BrdU incorporation was diminished in NP crypts, while in PP crypts incorporation was hardly affected. In PP and NP crypts, similar and increased levels of cleaved caspase-3-positive cells were observed after MTX. The enterocyte markers, sucrase-isomaltase, sodium-glucose co-transporter 1, glucose transporters 2 and 5, and intestinal and liver fatty acid binding protein, were down-regulated after MTX in NP epithelium but not in PP epithelium. In contrast, expression of the goblet cell markers, Muc2 and trefoil factor 3, and the Paneth cell marker, lysozyme, was maintained after MTX in both PP and NP epithelium. In conclusion, as MTX-induced apoptosis was similar in PP and NP crypts, the protection of the PP epithelium seems to be based on differences in the regulation of epithelial proliferation. Enterocyte function in the PP epithelium was unaffected by MTX treatment. Goblet and Paneth cell function was maintained in both NP and PP epithelium.     

Proliferation in Adrenocortical Tumors: Correlation with Clinical Outcome and p53 Status

There appears to be a relationship between mitotic activity and malignant behavior in adrenocortical tumors, and carcinomas with a high mitotic index may have a poorer prognosis. This has been investigated further by quantifying and comparing the Ki-67 index using antibody MIB-1 in a series of 14 adrenocortical adenomas and 40 carcinomas. The levels have been correlated with survival and disease-free survival in carcinomas and with evidence of abnormal p53 expression as detected by immunohistochemistry. Nevertheless, many carcinomas have a low level of proliferation that may reflect varying abnormalities within the regulation of both cell division and apoptosis. Expression of bcl-2 protein, an inhibitor of apoptosis has therefore also been examined. The Ki-67 index in carcinomas was significantly higher than in adenomas, but below 4% there was overlap. There was no significant difference in survival between carcinomas with MIB-1 index <3% and those greater, but the lower group had significantly longer disease-free survival (p=0.02). There was no significant difference between p53 immunopositive and p53 immunonegative carcinomas. No tumor showed immunopositivity for bcl-2 protein. It is concluded that MIB-1 index may contribute additional prognostic information in adrenocortical tumors. Inhibition of apoptosis by bcl-2 does not appear to play a role in tumor growth.     

Senescence and apoptosis in carcinogenesis of cervical squamous carcinoma.

Senescence and apoptosis are two key mechanisms that protect against cancer development. Many cell cycle regulators, such as p14(ARF), p15(INK4b) and p16(INK4a), are important in G1 cell cycle arrest and oncogene-induced senescence. The bcl-2 protein is one of the key components that control apoptosis, while the p53 protein plays key roles in both mechanisms. The genes of these key regulator proteins are often mutated or deleted in various malignancies. It is unknown how senescence and apoptosis are regulated in one of the most common tumors of the female genital tract, cervical squamous cell carcinoma (SCC). In this study the, expression of senescence, apoptosis and proliferation markers in normal cervical epithelium, cervical intraepithelial neoplasia (CIN) and SCC are characterized via immunohistochemical staining for p14(ARF), p15(INK4b), p16(INK4a), bcl-2, p53 and Ki-67 in tissue microarray blocks containing 20 samples each of normal cervix, moderate-to-severe cervical dysplasia (CIN II-III) and invasive SCC. Samples are derived from 60 total cases of cervical biopsies and cervical conizations. Results showed that the proliferation marker, Ki-67, is markedly increased, and the senescence markers, p15(INK4b), p16(INK4a) and p14(ARF) are overexpressed in both dysplasia and carcinoma. P53 immunostain is negative in all normal cervical tissue, and positive in dysplasia and carcinoma. Although the expression of bcl-2 is increased in dysplasia, this marker is negative in approximately half of SCC cases. These results suggest that some senescence pathways are activated and are still maintained in cervical dysplasia and carcinoma. However proliferation is increased and carcinogenesis is not thwarted, leading to eventual development of cervical cancer. Other mechanisms, such as those that account for the apparent overexpression of p53 and paradoxical loss of bcl-2 expression in some SCC cases, as well as additional senescence and apoptotic pathways, may play key roles carcinogenesis of cervical SCC.