Msh2, Mlh1, Fhit, p53, Bcl-2, and Bax expression in invasive and in situ squamous cell carcinoma of the uterine cervix.

To analyze relevant factors and their effects on neoplastic progression in cervical carcinoma, a panel of genetic markers was studied. Paraffin-embedded tissue sections were obtained from 37 patients with carcinoma of the uterine cervix, 14 noninvasive squamous cell carcinomas (NISCCs), and 23 invasive squamous cell carcinomas (ISCCs). Immunoreactivity of Msh2, Mlh1, Fhit, p53, Bcl-2, and Bax proteins was examined by immunohistochemical staining with appropriate antibodies. Positive staining of Msh2 was detected in 13 of 14 (92.9%) NISCCs and in 13 of 23 (56.5%) ISCCs (P < 0.02). Mlh1 immunoreactivity was observed in 10 of 14 (71.4%) NISCCs and in 8 of 23 (34.8%) ISCCs (P < 0.04). Overexpression of p53 protein was found in 4 of 14 (28.6%) NISCCs and in 16 of 23 (69.6%) ISCCs (P < 0.02). Bcl-2 overexpression was detected in 2 of 14 (14.3%) NISCCs and in 15 of 23 (65.2%) ISCCs (P < 0.003). No significant difference in the two types of lesion was found for Bax and Fhit expression. The relationship between Mlh1, Msh2, and p53 protein expression was significant (P < 0.001 and P < 0.001, respectively), as was that between Fhit and Bax immunoreactivity (P < 0.02). In conclusion, we consider that altered expression of Msh2, Mlh1, p53, and Bcl-2 may be a critical event during cervical cancer progression, whereas Fhit may be a component of a proapoptotic pathway.     

The expression of Bcl-2 family proteins differs between nonsmall cell lung carcinoma subtypes

BACKGROUND: Proteins of the Bcl-2 family play a key role in the control of apoptosis and carry out both proapoptotic and antiapoptotic functions. However, with the exception of Bcl-2 itself, little is known about the expression of these potentially critical proteins in nonsmall cell lung carcinoma. METHODS: Immunohistochemistry was used to study the expression of Bcl-2 and 6 other Bcl-2 family proteins in a pilot series of 41 archival nonsmall cell lung carcinoma specimens (19 adenocarcinomas and 22 squamous cell carcinomas). RESULTS: Overexpression of the apoptosis inhibitors Bcl-2 and Bcl-X(L) was observed in 10 of 41 samples (24%) and in 11 of 41 samples (27%), respectively. Loss of expression of proapoptotic proteins was observed as follows: Bak, 24 of 41 samples (59%); Bad, 21 of 41 samples (51%); Bid, 20 of 41 samples (49%); Bax, 14 of 41 samples (34%); and Bim/Bod, 2 of 41 samples (5%). Statistically significant differences in expression between adenocarcinoma samples and squamous cell carcinoma samples were observed for Bcl-X(L) (overexpression in 11 of 19 adenocarcinomas [58%] vs. 0 of 22 squamous cell carcinomas [0%]; P < 0.001) and for Bad (loss of expression in 5 of 19 adenocarcinomas [26%] vs. 16 of 22 squamous cell carcinomas [73%]; P = 0.004). CONCLUSIONS: Although this was only a pilot study, the results revealed significant differences in the expression of apoptosis-related proteins both between individual samples of nonsmall cell lung carcinoma and between the two main histologic subtypes. Such differences may play a role in the development of lung tumors; and, if it is found that these differences are of clinical importance, then it may be required to regard nonsmall cell lung carcinoma subtypes as separate entities rather than as one disease.     

The prognostic value of spontaneous apoptosis, Bax, Bcl-2, and p53 in oral squamous cell carcinoma of the tongue.

BACKGROUND: Bax, Bcl-2, and p53 proteins are involved in the regulation of apoptosis and have been reported to correlate with prognosis in several tumor types. METHODS: Bax, Bcl-2, p53, and the level of spontaneous apoptosis were evaluated in formalin fixed, paraffin embedded pretreatment specimens from 85 T1-4 squamous cell carcinomas (SCCs) of the tongue by immunohistochemical methods. The percentage of apoptotic cells labeled by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP labeling (TUNEL) method was expressed as an apoptotic index (AI). For Bax and Bcl-2 evaluation, the fraction of tumor cells stained and the staining intensities were given scores that were added together, resulting in a final score. p53 immunostaining was expressed as a percentage of positive cells. RESULTS: High AI was significantly associated with high Bax expression (P = 0.0122) and highly differentiated tumors (P = 0.0062). No correlation was found between AI and Bcl-2 expression. There was no correlation between p53 positivity and any of the other apoptosis-related parameters. Whereas low AI scores and low Bax expression correlated significantly with poor prognosis (P = 0.0053 and P = 0.0012, respectively), a low Bcl-2 expression was associated with a favorable clinical outcome (P = 0.0262). Patients with a high Bcl-2/Bax expression ratio had a significantly poorer prognosis than those with a low ratio (P < 0.0001). Multivariate analysis revealed that Bax expression, the Bcl-2/Bax expression ratio, and the T and N classifications were significantly independent prognostic variables. The Bcl-2/Bax expression ratio was the strongest independent prognostic parameter. CONCLUSIONS: AI, individual Bax and Bcl-2 expression, and particularly the Bcl-2/Bax expression ratio have prognostic value in SCC of the tongue.     

子宫颈鳞状细胞癌组织中细胞凋亡及相关调控基因蛋白的表达

目的：通过对细胞凋亡及部分相关蛋白表达进行检测,探讨子宫颈鳞状细胞癌组织中凋亡细胞的调控机制。方法：应用原位末端标记法（ＴＵＮＥＬ）和双重免疫荧光染色技术对正常子宫颈及不同分化程度的鳞状细胞癌组织中凋亡细胞和Ｂａｘ、Ｂｃｌ－２、ｃａｓｐａｓｅ－３蛋白表达进行检测,利用共聚焦显微镜观察结果。结果：ＴＵＮＥＬ法检测发现,每例标本均有不同程度的细胞凋亡,但数量及分布区域不完全相同,低分化鳞状细胞癌凋亡细     

热疗联合紫杉醇对人舌鳞癌细胞系CAL-27增殖、凋亡和周期影响

目的:观察热疗联合紫杉醇对人舌鳞癌细胞系CAL-27增殖、凋亡和周期的影响并探讨其机制。方法:CCK-8法确定紫杉醇工作浓度,将体外培养CAL-27细胞分为对照组、紫杉醇组、42℃热疗组和联合治疗组。克隆形成实验检测细胞增殖能力,流式细胞术检测细胞周期及凋亡,蛋白印迹法检测AKT、p-AKT、Bcl-2、Bax蛋白表达...     

Predictive value of MMP-7 expression for response to chemotherapy and survival in patients with non-small cell lung cancer

Fundamental studies have suggested that matrix metalloproteinases-7 (MMP-7) expression is associated with chemoresistance and constitutes a prognostic factor in several solid tumors. The present study assessed the prognostic and predictive value of MMP-7 in tumors of patients with advanced non-small cell lung cancer (NSCLC) treated with platinum-based chemotherapy. In total, 159 patients with stage III and IV NSCLC were retrospectively enrolled. Immunohistochemistry was performed to evaluate the expression of MMP-7, apoptosis-related proteins Bcl-2, Bax, Fas and FasL and the Ki-67 proliferation marker. The TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling) method was performed to investigate tumor apoptosis. Ninety carcinomas (56.6%) were identified as high expression of MMP-7. Overexpression of MMP-7 was more frequent in adenocarcinomas than in squamous cell carcinomas (P = 0.032). The expression of MMP-7 was positively related with Ki-67 index and Bcl-2, but not apoptosis index. MMP-7 status was correlated inversely with response to chemotherapy in overall patients (response rates, 20.0% and 35.8%, for patients with high-MMP-7 and low-MMP-7 tumors, respectively, P = 0.036), especially in adenocarcinoma (P = 0.021), but not in patients with squamous cell carcinomas (P = 0.373). The overall survival was significantly lower in NSCLC patients with high MMP-7 than in those with low MMP-7 (P < 0.001). A Cox regression analyses also demonstrated MMP-7 status to be a significant prognostic factor (hazard ratio, 5.49 P = 0.001). These findings suggest that the expression level of MMP-7 in tumor cells is predictive of response to chemotherapy and outcome in patients with advanced NSCLC receiving platinum-based chemotherapy.     

Immunohistochemical demonstration of apoptosis-regulated proteins,Bcl-2 and Bax,in resected non-small-cell lung cancers

Objective. Bcl-2 and Bax proteins regulate apoptosis independently, cooperatively, or both in vitro. The purpose of this study was to clarify the association between their expression with spontaneous apoptosis and various clinicopathologic features in patients with non-small-cell lung cancer (NSCLC). Methods. Bcl-2 protein, Bax protein, and spontaneous apoptosis were evaluated retrospectively in 70 resected specimens from NSCLC patients. Immunohistochemical (IHC) tests were used to assess the expression of Bcl-2 and Bax in the samples. The apoptotic index (AI) was also measured in these samples by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. We then evaluated the clinicopathologic features of all 70 samples and their relationships with malignancy. Results. Bcl-2 overexpression was significantly associated with male sex and squamous cell carcinoma (SCC). Bax overexpression was not associated with any clinicopathologic features. AI was significantly associated with SCC and negative nodal metastasis. No clear associations were found among Bcl-2 expression, Bax expression, and AI. Bcl-2/Bax ratios were not associated significantly with AI. Bcl-2, Bax, Bcl-2/Bax ratio, and the grading of AI did not have prognostic values. Conclusion. Bcl-2 overexpression was significantly associated with SCC. Spontaneous apoptosis was significantly associated with SCC and with negative nodal metastasis. Apoptosis-regulated proteins, Bcl-2 and Bax, and AI lack significant associations with each other and prognostic values in patients with resected NSCLC. Received: January 16, 2001 / Accepted: March 22, 2002     

Expression of Bax,a pro-apoptotic member of the Bcl-2 family,in esophageal squamous cell carcinoma

Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dyplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph-node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti-Bax antibody. Immunostaining was evaluated according to a score system (0–8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax was found in a fraction of pre-neoplastic and neoplastic lesions. Upon comparison of the amount of Bax expression between the different types of lesion, however, no significant differences were found between severe squamous cell dysplasias, carcinomas in situ, invasive carcinomas and lymph-node metastases. In both esophageal carcinoma cell lines, immunoreactivity for Bax was found and confirmed by means of Northern blot analysis. In invasive carcinomas, Bax immunoreactivity was inversely correlated with Bcl-2 expression (p = 0.0243) and decreased continuously with decreasing tumor differentiation (p = 0.0011). No correlation was found between Bax expression and the following parameters: depth of invasion, nodal status and tumor size. Bax expression had no influence on the post-operative survival of esophageal cancer patients. Int. J. Cancer 73:508–513, 1997. © 1997 Wiley-Liss, Inc.     

线粒体蛋白Bcl-2和Bax在肿瘤发生中作用的初步探讨

目的:研究线粒体蛋白(MAB1273)、Bcl-2、Bax在肾细胞癌(RCC)组织内的表达及相关性分析.方法:采用免疫组织化学SP方法检测9例嗜酸细胞瘤、6例嫌色细胞癌、23例透明细胞癌以及12例正常肾组织中MABl273、Bcl-2和Bax蛋白的表达.结果:MABl273和Bel-2在嗜酸细胞瘤、嫌色细胞癌、透明细胞癌中表达明显高于正常肾组织(P=0.006,P=0.008).Bax在各组间表达无明显差异(P=0.057).通过秩相关分析,MAB1273的表达与Bcl-2的表达呈正相关(r=0.341,P=0.015),而Bcl-2表达与Bax表达呈负相关(r=-0.287,P=0.043).结论:线粒体蛋白及Bcl-2的高表达、Bax低表达可能共同参与了肾嗜酸细胞瘤、嫌色细胞癌及透明细胞癌的发生,提示线粒体蛋白表达异常参与RCC细胞凋亡调控过程.     

Bcl-X expression in esophageal squamous cell carcinoma: association with tumor progression and prognosis

BACKGROUND AND OBJECTIVES: Bcl-2 family proteins are regulators of programmed cell death and important in the development and progression of human various tumors. The role of these proteins in the development, progression and differentiation of esophageal squamous cell carcinoma (ESCC) is unclear. METHODS: We investigated the expression of Bcl-2, Bcl-X, and Bax using immunohistochemistry in 86 ESCCs, and scored the expression by the weighted score. RESULTS: Bcl-2 expression related to pT category (P=0.043) and histological grade (P = 0.001). Bcl-X expression related to pT category (P = 0.003), pN category (P = 0.041) and the number of positive nodes (P = 0.036), and had a tendency to relate to histological grade (P = 0.086). Bax expression had a tendency to relate to pN category (P = 0.081). The inverse relationship between Bcl-2 and Bcl-X expression was detected (P = 0.001), while the positive one between Bcl-X and Bax expression was detected (P = 0.014). Patients with low Bcl-X weighted score had a significantly longer survival compared with those with high Bcl-X weighted score. Multivariate analysis revealed Bcl-X expression as the independent prognostic factors (P = 0.022). CONCLUSION: These results imply that Bcl-2 family proteins, especially Bcl-X, may contribute to the progression in ESCC.     

Apoptosis-associated proteins and the development of oral squamous cell carcinoma

Expression of apoptosis-associated proteins was evaluated in premalignant and malignant oral epithelial lesions, to test the hypothesis that protein regulation of apoptosis may be altered in the development of oral squamous cell carcinoma. Ninety archived paraffin-embedded specimens from 25 patients (two or more sequential biopsies each) and eight control specimens were evaluated in immunohistochemically stained sections for tumor suppressor protein p53, p53 binding protein mdm-2, and apoptosis regulatory proteins Bcl-2, Bcl-X, Bax, and Bak. The initial histologic diagnosis for 17/25 patients was either focal keratosis, mild dysplasia, or moderate dysplasia; the initial diagnosis for the remaining eight patients ranged from severe dysplasia to moderately differentiated squamous cell carcinoma. Thirty of 90 specimens showed positive p53 expression, nine of which were dysplasias. In patients with one or more lesions displaying p53 expression, there was increased intensity of staining with disease progression. Bak was expressed in 57/90 specimens, including 27 dysplasias of various grades. There was also a significantly increased intensity of Bak staining with disease progression, which did not appear to be dependent upon p53 status. Bcl-X was expressed in 73/90 specimens, with staining displayed earlier in premalignant lesions than either p53 or Bak. Ten of 90 specimens were positive for Bcl-2 (all were dysplasias or carcinomas), and only 2/90 specimens were positive for Bax. Eleven of 90 specimens were positive for mdm-2; six of which were also positive for p53. These data show that apoptosis-associated proteins are altered in variable patterns in both premalignant and malignant oral epithelial lesions. p53 and especially Bak and Bcl-X are expressed early; Bax is largely absent; and Bcl-2 and mdm-2 show sporadic expression in the development of oral premalignant and malignant disease.     

Expression of apoptotic regulators and their significance in cervical cancer

Insufficient apoptosis is implicated in many human cancers, including cervical carcinoma. The objectives of this study were to explore changes of apoptosis-regulating gene expression and their clinical significance in cervical cancer. The expression of apoptosis-regulating genes, including five Bcl-2 family and two caspase family members, was evaluated in 43 cervical invasive squamous cell carcinomas, using immunohistochemistry. Specimens in which >or=10% of the neoplastic cells showed cytosolic immunoreactivity were considered to be immunopositive. Results were correlated with clinico-pathologic characteristics of the subjects. All seven apoptotic regulators examined were positive in a proportion of the tumors. The percentage of cases expressing Bax was higher in the patients without evidence of disease after treatment than in the patients alive with disease or who died of disease (P<0.05). A significant difference in disease-free survival was detected between Bax-positive and -negative groups (P<0.05), and in overall survival between Mcl-1-positive and -negative groups (P<0.05). Significant association between the seven markers tested was only found for caspase 3 and Bak immunoreactivity in cervical carcinoma (P<0.05). The results demonstrate expression of multiple apoptosis-modulating proteins in cervical cancer. There appears to be complex regulation of apoptosis protein levels in association with clinical behavior of cervical squamous cell carcinoma.     

阿帕替尼调控WWOX对子宫内膜癌细胞增殖、凋亡、迁移、侵袭的影响及其机制研究

目的:探讨阿帕替尼（Apatinib）是否通过包含氧化还原酶的WW结构域（WWOX）影响子宫内膜癌细胞增殖、凋亡、迁移、侵袭。方法:噻唑蓝（MTT）比色法检测4 μmol/L、8 μmol/L、16 μmol/L、32 μmol/L Apatinib作用于子宫内膜癌细胞HEC-1 24 h、48 h、72 h后的细胞活性,流式细胞术检测细胞凋亡率;蛋白质印迹法（Western blot）检测细胞周期蛋白D1（Cyclin D1）、p21、B细胞淋巴瘤/白血病-2（Bcl-2）、Bcl-2相关X蛋白（Bax）、基质金属蛋白酶-2（MMP-2）、E-钙黏蛋白（E-cadherin）、WWOX蛋白水平,Transwell小室法检测迁移细胞数、侵袭细胞数。在HEC-1中转染pcDNA3.1-WWOX,或转染si-WWOX并用16 μmol/L Apatinib进行处理,采用上述方法评估细胞增殖、凋亡、迁移、侵袭情况。结果:Apatinib明显降低HEC-1细胞活性（P＜0.05）,呈剂量、时间依赖性;Apatinib显著增加HEC-1细胞凋亡率及p21、Bax蛋白表达量（P＜0.05）,呈剂量依赖性;Apatinib明显降低Cyclin D1、Bcl-2蛋白表达量（P＜0.05）,呈剂量依赖性;16 μmol/L Apatinib显著减少HEC-1细胞的迁移细胞数、侵袭细胞数、MMP-2蛋白表达量（P＜0.05）,明显提高E-cadherin、WWOX蛋白表达量（P＜0.05）。过表达WWOX明显降低HEC-1细胞中Cyclin D1、Bcl-2、MMP-2蛋白表达量、细胞活性、迁移细胞数、侵袭细胞数（P＜0.05）,提高p21、Bax、E-cadherin、WWOX蛋白表达量及细胞凋亡率（P＜0.05）。抑制WWOX表达逆转了Apatinib对HEC-1细胞中Cyclin D1、Bcl-2、MMP-2蛋白表达量、细胞活性、迁移、侵袭的抑制作用,以及逆转了其对p21、Bax、E-cadherin、WWOX蛋白表达量、细胞凋亡的促进作用。结论:阿帕替尼通过调控WWOX表达,抑制子宫内膜癌细胞增殖、迁移、侵袭,并诱导细胞凋亡。     

Reactive oxygen species (ROS) control the expression of Bcl-2 family proteins by regulating their phosphorylation and ubiquitination

We examined the influence of ROS on the phosphorylation and complex formation of Bcl-2 family proteins in Mn-superoxide dismutase (SOD) antisense-transfected squamous cell carcinoma cells, OSC-4 cells. The increase of intracellular ROS level induced by cis-diamminedichloroplatinum (CDDP) and gamma-ray treatment was greater in antisense-transfected cells than in control vector-transfected cells, and apoptosis was more extensively induced in the former. Antisense-transfected cells expressed high levels of Bax and Bak, but low levels of Bcl-2 and Bcl-XL when treated with CDDP, peplomycin, 5-fluorouracil or gamma-rays. After treatment with these agents, the phosphorylation of protein kinase A, Bcl-2 (Thr56) and Bad (Ser155) was increased, especially in antioxidant (N-acetylcysteine and pyrrolidine dithiocarbamate)-pretreated control cells, but the phosphorylation levels were very low in the antisense-transfected cells. Bcl-2 ubiquitination was increased, but ubiquitination of Bad and Bax was decreased in the antisense-transfected cells, although their ubiquitination was increased by the antioxidants. These results reveal that ROS induce apoptosis by regulating the phosphorylation and ubiquitination of Bcl-2 family proteins, resulting in increased proapoptotic protein levels and decreased antiapoptotic protein expression.     

Restored T-cell activation mechanisms in human tumour-infiltrating lymphocytes from melanomas and colorectal carcinomas after exposure to interleukin-2

We investigated the effects of interleukin-2 (IL-2) exposure on T-cell signal transduction molecules and apoptosis markers in tumour-infiltrating lymphocytes (TIL) isolated from 20 melanoma and 16 colorectal carcinoma metastases and expanded in vitro for therapeutic reinfusion. Before IL-2 culture, TIL showed undetectable or very low levels of T-cell receptor (TCR) epsilon chain, p56(lck), Fas ligand (FasL) and Bax expression, while Bcl-2 values were elevated. Cancer cells were characterised by low or absent Fas and Bcl-2 and high Bax expression. Notably, they also expressed FasL. After 41-48 days of IL-2 culture, TCR epsilon chain and p56(lck) expression of TIL rose to median values of approximately 80 and 30% positive cells, respectively (P<0.001), FasL expression was detected in 45% cells from melanomas (P<0.001) and in 3% from colorectal carcinomas (P=0.09), and Bax-positive cells increased from 17.5 to 70% (P=0.005). Moreover, TCR zeta chain-positive cells were significantly increased from baseline (P=0.001), Bcl-2-positive cells dropped from 50 to 1% (P=0.007) and perforin content was high, while Fas expression was not significantly modified by IL-2 culture. In conclusion, our data suggest that the degree of immunosuppression in TIL from melanomas and colorectal carcinomas is very high, and the apoptosis markers' repertoire of cancer cells resembles that of immune-privileged tissue. Interleukin-2 culture appears to restore lymphocyte activation mechanisms, resulting in consistent FasL expression and perforin production.     

Chronic hypoxia protects against gamma-irradiation-induced apoptosis by inducing bcl-2 up-regulation and inhibiting mitochondrial translocation and conformational change of bax protein

Malignant tumours contain zones of chronic or acute hypoxia, which influence their prognosis and progression. The goal of our study was to understand the role of hypoxia in radio-resistance in a squamous cell carcinoma cell line of the head and neck (KB-3-1 cells). Cell growth was evaluated by Trypan blue exclusion under chronic hypoxia (3-5% O2) for 4 weeks or under normal conditions (21% O2). Cells were then gamma-irradiated either by X-ray (2-6 Gy) or UV-C radiation (0.001-10 J/cm(2)). Apoptosis was estimated by double staining with orange acridine and ethydium bromide and fluorescence microscopy. DNA content was estimated by FACS analysis. Expression of Bax, Bcl-2 and P53 was assessed by immunofluorescence and Western blotting. ROS production was measured by dichlorofluorescein fluorescence. Cell growth depends on oxygen tension. It decreased by 42 and 70% at 5 and 3% O2 compared to control with a significant cell cycle arrest rather than increased mortality. Hypoxic cells are more radio-resistant (x2.5) than normoxic cells. Under chronic hypoxia, Bcl-2 increased considerably in cells compared to control, while Bax and P53 did not change. After irradiation, in hypoxic cells very weak expression of the pro-apoptotic Bax protein and no translocation of Bax to the mitochondria were observed. In addition, irradiation of control KB-3-1 cells demonstrated a large increase in ROS production (x2) compared to cells irradiated identically under hypoxia. In conclusion, chronic hypoxia: i) seems to slow-down cell growth of KB-3-1 cells without inducing apoptosis, ii) induces Bcl-2 overexpression and prevents radiation-induced apoptosis by inhibiting ROS production and altering Bax subcellular redistribution and conformational changes.     

Apoptosis, cell proliferation and expression of Bcl-2 and Bax in gastric carcinomas: immunohistochemical and clinicopathological study.

To clarify the relation between bcl-2 and bax protein (Bcl-2 and Bax) expression with regard to apoptosis and cell proliferation, 82 gastric carcinomas were immunohistochemically investigated. The significance of apoptosis for biological behaviour of the tumours was also examined. The apoptotic indices (AIs) were significantly lower in early-stage than in advanced-stage lesions (P<0.05), being positively correlated with the mitotic indices (MIs) (r=0.447, P<0.001). No association between either AIs or MIs and tumour size (diameter of intramural spreading) was noted. The AIs in the high Bcl-2-immunoreactive score group were significantly smaller than in either the low or the negative categories, whereas they were relatively elevated in the high Bax score group. In addition, an inverse correlation between Bcl-2 and Bax expression was revealed for both AIs and MIs. Although depth of tumour invasion and lymph node status were clearly associated with favourable outcome, no relation between survival rates and average values of either AIs or MIs, or immunoreactive scores for Bcl-2 and Bax was observed. These results indicate that in gastric carcinomas, apoptosis is closely associated with cell proliferation and expression of Bcl-2 and Bax, but appears likely to have no particular biological significance as a prognostic factor.     

Loss of Bcl-2 in invasive breast cancer is associated with high rates of cell death, but also with increased proliferative activity.

Bcl-2 has been demonstrated to inhibit apoptosis in breast cancer cells in vitro, and the ratio between Bcl-2 and its proapoptotic homologue Bax seems to be an important determinant of cellular sensitivity to induction of apoptosis. However, little information is available on the relationship between Bcl-2 and the rate of apoptotic and necrotic cell death in breast tumours. From a series of 441 premenopausal, lymphnode-negative breast cancer patients, a subset of 49 tumours was selected in which immunostaining for the 26-kDa isoform of Bcl-2 was either absent (n = 23) or very high (n = 26). High expression of Bcl-2 was found to be strongly associated with low rates of apoptotic (P < 0.001) and necrotic cell death (P < 0.001). The mean value of the apoptotic index was 2.69%+/-1.40% in Bcl-2-negative tumours and 0.68%+/-1.00% in Bcl-2-positive tumours. Expression of the proapoptotic protein Bax correlated neither with Bcl-2 nor with the frequency of apoptotic cells. Immunostaining for the antiapoptotic Bcl-2 homologue BcI-X(L) correlated with Bcl-2 expression (P < 0.001) but not with apoptosis. High proliferation rate and high tumour grade (Bloom-Richardson) were strongly associated with absence of Bcl-2 expression (P< 0.001). p53 accumulation was associated with absence of Bcl-2 expression and increased apoptotic activity. Loss of Bcl-2 expression was strongly correlated with increased apoptotic and necrotic cell death, high proliferation rate and high tumour grade, supporting a model in which Bcl-2 not only mediates cell death, but also cell division in breast cancer tissue, and in which regulation of cell division and cell death are tightly linked.