Bcl-2 expression correlates with lymphovascular invasion and long-term prognosis in breast cancer

Detachable MOF-Based Core/Shell Nanoreactor for Cancer Dual-Starvation Therapy With Reversing Glucose and Glutamine Metabolisms

Tumor-dependent glucose and glutamine metabolisms are essential for maintaining survival, while the accordingly metabolic suppressive therapy is limited by the compensatory metabolism and inefficient delivery efficiency. Herein, a functional metal-organic framework (MOF)-based nanosystem composed of the weakly acidic tumor microenvironment-activated detachable shell and reactive oxygen species (ROS)-responsive disassembled MOF nanoreactor core is designed to co-load glycolysis and glutamine metabolism inhibitors glucose oxidase (GOD) and bis-2-(5-phenylacetmido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES) for tumor dual-starvation therapy. The nanosystem excitingly improves tumor penetration and cellular uptake efficiency via integrating the pH-responsive size reduction and charge reversal and ROS-sensitive MOF disintegration and drug release strategy. Furthermore, the degradation of MOF and cargoes release can be self-amplified via additional self-generation H2 O2 mediated by GOD. Last, the released GOD and BPTES collaboratively cut off the energy supply of tumors and induce significant mitochondrial damage and cell cycle arrest via simultaneous restriction of glycolysis and compensatory glutamine metabolism pathways, consequently realizing the remarkable triple negative breast cancer killing effect in vivo with good biosafety via the dual starvation therapy.

Prognostic influences of B-cell lymphoma 2-positive expression on late recurrence in breast cancer

Purpose

B-cell lymphoma 2 (BCL2) has an antiapoptotic role, however, has resulted in it being a powerful favorable prognostic factor in breast cancer. Several studies revealed BCL2 is strongly associated with a lower rate of early recurrence after initial treatment in breast cancer patients, but study of a prolonged effect after 5 years is lacking. We investigated BCL2 as a prognostic factor in breast cancer in comparison to early and late recurrence.

Methods

We retrieved data from 2,198 patients with primary breast cancer who underwent surgical treatment and adjuvant treatment at the breast cancer center between 2005 and 2015. Each molecular subtype was classified, and Ki-67 and BCL2 were also assessed by immunohistochemistry. BCL2 and the association between molecular subtypes were assessed in early and late recurrences, respectively. Five-year postrecurrence survival and BCL2 were also assessed.

Results

The BCL2-positive group was associated with favorable clinicopathologic characteristics. The time to recurrence was significantly longer in the BCL2-positive group (P = 0.035). Late recurrence after 5 years was higher in the BCL2-positive group (P = 0.029). In multivariate survival analysis, tumor size and BCL2-positive expression were the only independent prognostic factors for late recurrence (P = 0.004). In the patients with recurrence, 5-year postrecurrence survival was significantly higher in the BCL2-positive group (P < 0.001).

Conclusion

Our result showed that prognosis was better in BCL2-positive patients compared to BCL2-negative patients at late recurrence. We suggested that BCL2 expression could be used as a marker to help determine additional adjuvant therapy or extended hormone therapy in hormone-dependent breast cancer.

Does the Expression of Vascular Endothelial Growth Factor (VEGF) and Bcl-2 Have a Prognostic Significance in Advanced Non-Small Cell Lung Cancer?

Lung cancer is the most common cause of mortality from malignant tumors worldwide. The five-year survival rate for people with advanced stages varies considerably, from 35.4% to 6.9%. The angiogenic potential of bcl2 is not well known, nor is the way in which tumor cells with excessive bcl2 expression affect VEGF production. Hypothetically, given that tumor growth, progression and metastasis are dependent on angiogenesis, the antiapoptotic effect is expected to form a link between these two molecules. The aim of this study was to evaluate the relationship between bcl-2 and VEGF expression, clinicopathological features and survival in 216 patients with advanced NSCLC. Archival tumor tissues were examined by immunohistochemistry for the expression of bcl-2 and VEGF. Immunoreactivity for bcl-2 was observed in 41.4% of NSCLCs, 51% of squamous and 34.8% of adenocarcinomas-expressed Bcl-2. There was an inverse correlation of mononuclear stromal reaction and bcl-2 expression in adenocarcinoma (p < 0.0005). A total of 71.8% NSCLCs were VEGF positive, 56% of squamous and 82.2% of adenocarcinomas. High level of VEGF expression was significantly associated with histology type (p = 0.043), low histology grade (p = 0.014), clinical stage IV (p = 0.018), smoking history (p = 0.008) and EGFR mutations (p = 0.026). There was an inverse correlation in the expression of Bcl-2 and VEGF in NSCLC patients (p = 0.039, r = -0.163). Two-year survival of patients with unresectable NSCLC was 39.3%, and 50% of patients were alive at 17 months. Our results demonstrated no difference in survival for patients in advanced NSCLC grouped by bcl-2 and VEGF status. Additionally, we observed an inverse correlation in the expression of Bcl-2 and VEGF in NSCLC and mononuclear reaction and bcl-2 expression in adenocarcinomas.

A Signature of Three Apoptosis-Related Genes Predicts Overall Survival in Breast Cancer

Background

The commonest malignancy in women is known as breast cancer (BC). Numerous studies demonstrated that apoptosis appears to be critical to the management and clinical outcome of BC patients. The purpose of this study is to explore the potential connection between apoptosis and BC and establish the apoptosis-associated gene signature in BC.

Methods

The data of BC patient transcripts and related clinical information comes from the Cancer Genome Atlas Database (TCGA), and the genes related to apoptosis come from the Molecular Characterization Database (MSigDB). We identified the abnormally expressed apoptosis-related genes in BC samples. The optimal apoptosis-related genes screened by Cox regression analysis were designed to construct a prognostic model for predicting BC patients. Using the Nom Chart to Predict 1-Year, 3-Year, and 5-Year overall survival for BC patients. The gene signature-related functional pathways were explored by gene set enrichment analysis (GSEA).

Results

Three genes [alpha subunit of the interleukin 3 receptor (IL3RA), apoptosis-inducing factor mitochondrial-associated 1 (AIFM1), and phosphatidylinositol-3 kinase catalytic alpha (PIK3CA)] correlated with apoptosis were shown to be strongly linked to the overall survival of BC. Survival analysis shows that the risk score is directly proportional to the poor prognosis of BC patients. Risk assessment based on three genetic characteristics (age, pathological stage N, and pathological stage M) can independently predict the prognosis of patients with BC. The Nom chart is most suitable for assessing the long-term survival rate of BC patients. The results of GSEA demonstrated that numerous cell cycle-related pathways were abundant in the high-risk group.

Conclusion

We constructed an apoptosis-associated gene signature in BC, which had a potential clinical application prospect for BC patients.

HPV16 E1 dysregulated cellular genes involved in cell proliferation and host DNA damage: A possible role in cervical carcinogenesis

HPV16 is the most prominent cause of cervical cancer. HPV16 E1, a helicase required for HPV replication exhibits increased expression in association with cervical cancer progression, suggesting that E1 has a similar effect on the host as the HPV16 E6 and E7 oncoproteins. This study aimed to determine whether expression of HPV16 E1 correlated with carcinogenesis by modulating cellular pathways involved in cervical cancer. HEK293T cells were transfected with pEGFP, pEGFPE1 or truncated forms of HPV16 E1. Cell proliferation, cell death, and the impact of HPV16 E1 on host gene expression was then evaluated. HPV16 E1 overexpression resulted in a significant reduction of cell viability and cellular proliferation (p-value<0.0001). Moreover, prolonged expression of HPV16 E1 significantly induced both apoptotic and necrotic cell death, which was partially inhibited by QVD-OPH, a broad-spectrum caspase inhibitor. Microarray, real time RT-PCR and kinetic host gene expression analyses revealed that HPV16 E1 overexpression resulted in the downregulation of genes involved in protein synthesis (RPL36A), metabolism (ALDOC), cellular proliferation (CREB5, HIF1A, JMJDIC, FOXO3, NFKB1, PIK3CA, TSC22D3), DNA damage (ATR, BRCA1 and CHEK1) and immune response (ISG20) pathways. How these genetic changes contribute to HPV16 E1-mediated cervical carcinogenesis warrants further studies.

Targeting Bcl-2 for cancer therapy

Apoptosis deficiency is one of the most important features observed in neoplastic diseases. The Bcl-2 family is composed of a subset of proteins that act as decisive apoptosis regulators. Research and clinical studies have both demonstrated that the hyperactivation of Bcl-2-related anti-apoptotic effects correlates with cancer occurrence, progression and prognosis, also having a role in facilitating the radio- and chemoresistance of various malignancies. Therefore, targeting Bcl-2 inactivation has provided some compelling therapeutic advantages by enhancing apoptotic sensitivity or reversing drug resistance. Therefore, this pharmacological route turned into one of the most promising routes for cancer treatment. This review discusses some of the well-defined and emerging roles of Bcl-2 as well as its potential clinical value in cancer therapeutics.

BIK drives an aggressive breast cancer phenotype through sublethal apoptosis and predicts poor prognosis of ER-positive breast cancer

Apoptosis is fundamental to normal animal development and is the target for many anticancer therapies. Recent studies have explored the consequences of "failed apoptosis" where the apoptotic program is initiated but does not go to completion and does not cause cell death. Nevertheless, this failed apoptosis induces DNA double-strand breaks generating mutations that facilitate tumorigenesis. Whether failed apoptosis is relevant to clinical disease is unknown. BCL-2 interacting killer (BIK) is a stress-induced BH3-only protein that stimulates apoptosis in response to hormone and growth factor deprivation, hypoxia, and genomic stress. It was unclear whether BIK promotes or suppresses tumor survival within the context of breast cancer. We investigated this and show that BIK induces failed apoptosis with limited caspase activation and genomic damage in the absence of extensive cell death. Surviving cells acquire aggressive phenotypes characterized by enrichment of cancer stem-like cells, increased motility and increased clonogenic survival. Furthermore, by examining six independent cohorts of patients (total n = 969), we discovered that high BIK mRNA and protein levels predicted clinical relapse of Estrogen receptor (ER)-positive cancers, which account for almost 70% of all breast cancers diagnosed but had no predictive value for hormone receptor-negative (triple-negative) patients. Thus, this study identifies BIK as a biomarker for tumor recurrence of ER-positive patients and provides a potential mechanism whereby failed apoptosis contributes to cancer aggression.

Inhibition of Anti-Apoptotic Bcl-2 Proteins in Preclinical and Clinical Studies: Current Overview in Cancer

The dynamic interplay between pro-death and pro-survival Bcl-2 family proteins is responsible for a cell’s fate. Due to the recognized relevance of this family in cancer progression and response to therapy, different efforts have made in recent years in order to develop small molecules able to target anti-apoptotic proteins such as Bcl-2, Bcl-xL and Mcl-1. The limitations of the first Bcl-2 family targeted drugs, regarding on-target and off-target toxicities, have been overcome with the development of venetoclax (ABT-199), the first BH3 mimetic inhibitor approved by the FDA. The purpose of this review is to discuss the state-of-the-art in the development of drugs targeting Bcl-2 anti-apoptotic proteins and to highlight the potential of their application as single agents or in combination for improving anti-cancer therapy, focusing in particular on solid tumors.

Mitochondrial Involvement in Migration, Invasion and Metastasis

Mitochondria in addition to be a main cellular power station, are involved in the regulation of many physiological processes, such as generation of reactive oxygen species, metabolite production and the maintenance of the intracellular Ca²⁺ homeostasis. Almost 100 years ago Otto Warburg presented evidence for the role of mitochondria in the development of cancer. During the past 20 years mitochondrial involvement in programmed cell death regulation has been clarified. Moreover, it has been shown that mitochondria may act as a switchboard between various cell death modalities. Recently, accumulated data have pointed to the role of mitochondria in the metastatic dissemination of cancer cells. Here we summarize the modern knowledge concerning the contribution of mitochondria to the invasion and dissemination of tumor cells and the possible mechanisms behind that and attempts to target metastatic cancers involving mitochondria.

Bcl-2 promotes metastasis through the epithelial-to-mesenchymal transition in the BCap37 medullary breast cancer cell line

Metastatic breast cancer is one of the major types of cancer in women. However, despite being the focus of considerable research efforts, its molecular mechanism remains to be fully elucidated. The B-cell lymphoma/leukemia gene-2 (Bcl-2) protein is well known for its role in inhibiting programmed cell death/apoptosis. However, little is known concerning its function in cell invasion and migration. In the present study, cell migration and invasion assays revealed that anti-apoptotic Bcl-2 protein induced migration and invasion without affecting cell proliferation in the BCap37 breast cancer cell line. In addition, it was found that the overexpression of Bcl-2 in BCap37 cells increased metastasis to the lung in a mouse model. Using western blotting and RT q-PCR analysis, it was demonstrated that the overexpression of Bcl-2 inhibited the expression of E-cadherin, an epithelial marker, whereas it increased the levels of mesenchymal markers N-cadherin and vimentin. Therefore, the results suggested that Bcl-2 may induce cellular metastasis in breast cancer via the epithelial-to-mesenchymal transition.

MicroRNA-148a promotes apoptosis and suppresses growth of breast cancer cells by targeting B-cell lymphoma 2

MicroRNAs (miRNAs) contribute toward tumorigenesis through the modulation of tumor-related genes. MiR-148a has been characterized as a tumor-suppressing miRNA and its downregulation has been reported in tumors of a variety of cancers. However, the functional role of miR-148a in breast cancer is not yet fully understood. Using both in-vitro and in-vivo models, we confirmed that miR-148a acts to inhibit the proliferation of breast cancer cells. Through the use of bioinformatic approaches in miRNA target prediction, we determined that B-cell lymphoma 2 (BCL-2) is a likely target of miR-148a. The overexpression and tumorigenic effects of BCL-2 have already been confirmed in cancerous tumors of the breast. A dual-luciferase assay was performed to confirm that miR-148a targets the 3'-untranslated region of BCL-2. In this study, we first characterized the downregulation of miR-148a in breast cancer tissues. We then found that restoring expression of miR-148a suppressed the expression of BCL-2 at the level of both mRNA and protein. Upregulation of miR-148a caused a subsequent reduction of proliferation and an increase in apoptosis. In conclusion, we have confirmed the role of miR-148a as a pivotal regulator in breast cancer through its targeting of BCL-2. This evidence strongly suggests that miR-148a could prove to be a novel therapeutic target in breast cancer.

Bcl-2 family proteins as regulators of cancer cell invasion and metastasis: a review focusing on mitochondrial respiration and reactive oxygen species

Although Bcl-2 family proteins were originally identified as key regulators of apoptosis, an impressive body of evidence has shown that pro-survival members of the Bcl-2 family, including Bcl-2, Bcl-X_L, and Bcl-w, can also promote cell migration, invasion, and cancer metastasis. Interestingly, cell invasion was recently found to be suppressed by multidomain pro-apoptotic members of the Bcl-2 family, such as Bax and Bak. While the mechanisms underlying these new functions of Bcl-2 proteins are just beginning to be studied, reactive oxygen species (ROS) have emerged as inducers of cell invasion and the production of ROS from mitochondrial respiration is known to be promoted and suppressed by the pro-survival and multidomain pro-apoptotic Bcl-2 family members, respectively. Here, I review the evidence supporting the ability of Bcl-2 proteins to regulate cancer cell invasion and metastasis, and discuss our current understanding of their underlying mechanisms, with a particular focus on mitochondrial respiration and ROS, which could have implications for the development of strategies to overcome tumor progression.

Prognostic values of negative estrogen or progesterone receptor expression in patients with luminal B HER2-negative breast cancer

BACKGROUND

The luminal subtype of breast cancer is sensitive to anti-estrogen therapy and shows a better prognosis than that of human epidermal growth factor receptor2 (HER2)-enriched or triple-negative breast cancer. However, the luminal type of breast cancer is heterogeneous and can have aggressive clinical features. We investigated the clinical implications of single hormone receptor negativity in a luminal B HER2-negative group.

METHODS

We collected luminal B HER2-negative breast cancer data that were estrogen receptor (ER) and/or progesterone receptor (PR) positive, Ki 67 high (>14 %), and HER2 negative and divided them into the ER- and PR-positive group and the ER- or PR-negative group. We analyzed the clinical and pathological data and survival according to ER or PR loss.

RESULTS

There were no statistical differences in TNM stage, breast and axillary operative methods, or number of tumors between the ER- and PR-positive group and ER- or PR-negative group. However, the ER- or PR-negative group was associated with older age (≥45 years), higher histological grade, lower Bcl-2 expression, and far higher Ki 67 (>50 %). Disease-free survival (DFS) and overall survival (OS) were shorter in the ER- or PR-negative group than that in the ER- and PR-positive group (p = 0.0038, p = 0.0071).

CONCLUSIONS

ER- or PR-negative subgroup showed worse prognosis than ER- and PR-positive subgroup in the luminal B HER2-negative group. We could consider the negativity of ER or PR as prognostic marker in luminal B HER2-negative subtype of breast cancer.

A fate worse than death: apoptosis as an oncogenic process

Apoptotic cell death is widely considered a positive process that both prevents and treats cancer. Although undoubtedly having a beneficial role, paradoxically, apoptosis can also cause unwanted effects that may even promote cancer. In this Opinion article we highlight some of the ways by which apoptosis can exert oncogenic functions. We argue that fully understanding this dark side will be required to optimally engage apoptosis, thereby maximizing tumour cell kill while minimizing unwanted pro-tumorigenic effects.

Cancer Hallmarks, Biomarkers and Breast Cancer Molecular Subtypes

Breast cancer is a complex disease encompassing multiple tumor entities, each characterized by distinct morphology, behavior and clinical implications. Besides estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, novel biomarkers have shown their prognostic and predictive values, complicating our understanding towards to the heterogeneity of such cancers. Ten cancer hallmarks have been proposed by Weinberg to characterize cancer and its carcinogenesis. By reviewing biomarkers and breast cancer molecular subtypes, we propose that the divergent outcome observed from patients stratified by hormone status are driven by different cancer hallmarks. 'Sustaining proliferative signaling' further differentiates cancers with positive hormone receptors. 'Activating invasion and metastasis' and 'evading immune destruction' drive the differentiation of triple negative breast cancers. 'Resisting cell death', 'genome instability and mutation' and 'deregulating cellular energetics' refine breast cancer classification with their predictive values. 'Evading growth suppressors', 'enabling replicative immortality', 'inducing angiogenesis' and 'tumor-promoting inflammation' have not been involved in breast cancer classification which need more focus in the future biomarker-related research. This review novels in its global view on breast cancer heterogeneity, which clarifies many confusions in this field and contributes to precision medicine.

Profiling of alternative polyadenylation sites in luminal B breast cancer using the SAPAS method

Breast cancer (BC) is a leading cause of cancer-related mortality in females and is recognized as a molecularly heterogeneous disease. Previous studies have suggested that alternative messenger RNA (mRNA) processing, particularly alternative polyadenylation [poly(A)] (APA), can be a powerful molecular biomarker with prognostic potential. Therefore, in the present study, we profiled APA sites in the luminal B subtype of BC by sequencing APA sites (SAPAS) method, in order to assess the relation of these APA site-switching events to the recognized molecular subtypes of BC, and to discover novel candidate genes and pathways in BC. Through comprehensive analysis, the trend of APA site-switching events in the 3' untranslated regions (3'UTRs) in the luminal B subtype of BC were found to be the same as that in MCF7 cell lines. Among the genes involved in the events, a significantly greater number of genes was found with shortened 3'UTRs in the samples, which were samples of primary cancer with relatively low proliferation. These findings may provide novel information for the clinical diagnosis and prognosis on a molecular level. Several potential biomarkers with significantly differential tandem 3'UTRs and expression were found and validated. The related biological progresses and pathways involved were partly confirmed by other studies. In conclusion, this study provides new insight into the diagnosis and prognosis of BC from the APA site profile aspect.

MiR-148a regulates the growth and apoptosis in pancreatic cancer by targeting CCKBR and Bcl-2

Our previous studies have revealed that miR-148a is downregulated in pancreatic cancer. Bioinformatics analysis has shown cholecystokinin-B receptor (CCKBR) and B cell lymphoma (Bcl-2) to be potential targets of miR-148a. But the pathophysiologic role of miR-148a and its relevance to the growth and development of pancreatic cancer are yet to be investigated. The purpose of this study is to elucidate the molecular mechanisms where miR-148a acts as a tumor suppressor in pancreatic cancer. Our results showed significant downregulation of miR-148a in 28 pancreatic cancer tissue samples and five pancreatic cancer cell lines, compared with their non-tumor counterparts by qRT-PCR. MiR-148a was found to not only inhibit the proliferation of pancreatic cancer cells (PANC-1 and AsPC-1) in vitro by MTT assay and colony formation assay, but also to promote cells apoptosis in vitro by Annexin V-FITC apoptosis detection and caspase activity assay. Using western blot and luciferase activity assay, CCKBR and Bcl-2 were identified as targets of miR-148a. Moreover, we also found that the expression of Bcl-2 lacking in 3'UTR could abrogate the pro-apoptosis function of miR-148a. These findings suggest the importance of miR-148a's targeting of CCKBR and Bcl-2 in the regulation of pancreatic cancer growth and apoptosis.

Different prognostic factors correlate with Bcl-2 expression among triple negative and non-triple negative breast cancers

BACKGROUND

Prognostication of breast cancer using clinico-pathologic variables, although useful, remains imperfect. Recent research has focused on finding new markers of prognosis using gene expression profiling. Panels of proteins assessed by immunohistochemistry might also be useful in this regard. This study focused on Bcl-2 protein expression in triple-negative (TNBC) and non- triple-negative breast cancer (non-TNBC) with correlation to clinico-pathologic variables.

MATERIALS AND METHODS

We analyzed Bcl-2 expression in 77 women with primary breast carcinoma divided into two groups; triple-negative and non- triple-negative according to expression of estrogen (ER), progesterone (PR) and human epidermal growth factor receptors (Her2/neu). Bcl-2 expression was assessed in relation to age, histo-pathological subtype, grade, nodal status and tumor size.

RESULTS

Bcl-2 was expressed in 74% of triple-negative breast cancers and 70% of non- triple-negative cancers. In TNBC, expression was significantly correlated with invasive ductal subtype, while in non-TNBC it was significantly correlated with age and negative nodal status. In both groups higher Bcl-2 expression associated with favourable prognostic factors in breast cancer, but no significant statistical correlations were found.

CONCLUSIONS

Frequency of Bcl-2 expression does not differ between TNBC and non-TNBC, but different prognostic factors correlate with Bcl-2 in the two cases.

Calpastatin is associated with lymphovascular invasion in breast cancer

Metastasis of breast cancer is a major contributor to mortality. Histological assessment of vascular invasion (VI) provides important prognostic information and demonstrates that VI occurs predominantly via lymphatics in breast cancer. We sought to examine genes and proteins involved in lymphovascular invasion (LVI) to understand the mechanisms of this key disease process. A gene expression array of 91 breast cancer patients was analysed by an Artificial Neural Network (ANN) approach using LVI to supervise the analysis. 89 transcripts were significantly associated (p<0.001) with the presence of LVI. Calpastatin, a specific calpain inhibitor, had the second lowest selection error and was investigated in breast cancer specimens using real-time PCR (n=56) and immunohistochemistry (n=53). Both calpastatin mRNA and protein levels were significantly associated with the presence of LVI (p=0.014 and p=0.025 respectively). The data supports the hypothesis that calpastatin may play a role in regulating the initial metastatic dissemination of breast cancer.

BCL2 in breast cancer: a favourable prognostic marker across molecular subtypes and independent of adjuvant therapy received

BACKGROUND

Breast cancer is heterogeneous and the existing prognostic classifiers are limited in accuracy, leading to unnecessary treatment of numerous women. B-cell lymphoma 2 (BCL2), an antiapoptotic protein, has been proposed as a prognostic marker, but this effect is considered to relate to oestrogen receptor (ER) status. This study aimed to test the clinical validity of BCL2 as an independent prognostic marker.

METHODS

Five studies of 11 212 women with early-stage breast cancer were analysed. Individual patient data included tumour size, grade, lymph node status, endocrine therapy, chemotherapy and mortality. BCL2, ER, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) levels were determined in all tumours. A Cox model incorporating the time-dependent effects of each variable was used to explore the prognostic significance of BCL2.

RESULTS

In univariate analysis, ER, PR and BCL2 positivity was associated with improved survival and HER2 positivity with inferior survival. For ER and PR this effect was time dependent, whereas for BCL2 and HER2 the effect persisted over time. In multivariate analysis, BCL2 positivity retained independent prognostic significance (hazard ratio (HR) 0.76, 95% confidence interval (CI) 0.66-0.88, P<0.001). BCL2 was a powerful prognostic marker in ER- (HR 0.63, 95% CI 0.54-0.74, P<0.001) and ER+ disease (HR 0.56, 95% CI 0.48-0.65, P<0.001), and in HER2- (HR 0.55, 95% CI 0.49-0.61, P<0.001) and HER2+ disease (HR 0.70, 95% CI 0.57-0.85, P<0.001), irrespective of the type of adjuvant therapy received. Addition of BCL2 to the Adjuvant! Online prognostic model, for a subset of cases with a 10-year follow-up, improved the survival prediction (P=0.0039).

CONCLUSIONS

BCL2 is an independent indicator of favourable prognosis for all types of early-stage breast cancer. This study establishes the rationale for introduction of BCL2 immunohistochemistry to improve prognostic stratification. Further work is now needed to ascertain the exact way to apply BCL2 testing for risk stratification and to standardise BCL2 immunohistochemistry for this application.

BCL2 inhibits cell adhesion, spreading, and motility by enhancing actin polymerization

BCL2 is best known as a multifunctional anti-apoptotic protein. However, little is known about its role in cell-adhesive and motility events. Here, we show that BCL2 may play a role in the regulation of cell adhesion, spreading, and motility. When BCL2 was overexpressed in cultured murine and human cell lines, cell spreading, adhesion, and motility were impaired. Consistent with these results, the loss of Bcl2 resulted in higher motility observed in Bcl2-null mouse embryonic fibroblast (MEF) cells compared to wild type. The mechanism of BCL2 regulation of cell adhesion and motility may involve formation of a complex containing BCL2, actin, and gelsolin, which appears to functionally decrease the severing activity of gelsolin. We have observed that the lysate from MCF-7 and NIH3T3 cells that overexpressed BCL2 enhanced actin polymerization in cell-free in vitro assays. Confocal immunofluorescent localization of BCL2 and F-actin during spreading consistently showed that increased expression of BCL2 resulted in increased F-actin polymerization. Thus, the formation of BCL2 and gelsolin complexes (which possibly contain other proteins) appears to play a critical role in the regulation of cell adhesion and migration. Given the established correlation of cell motility with cancer metastasis, this result may explain why the expression of BCL2 in some tumor cell types reduces the potential for metastasis and is associated with improved patient prognosis.

Prognostic value of p53 and bcl-2 expression in patients treated with breast conservative therapy

Prognostic value of p53 and bcl-2 expression on treatment outcome in breast cancer patients has been extensively evaluated, but the results were inconclusive. We evaluated the prognostic significance of these molecular markers in patients treated with breast conserving surgery and radiotherapy. One hundred patients whose immunostaining of p53 and bcl-2 expression was available among 125 patients who underwent radiotherapy after breast conserving surgery and axillary lymph node dissection were enrolled into this study. Eighty-seven patients also received adjuvant chemotherapy and/or hormonal therapy. Conventional clinicopathologic variables and treatment-related factors were also considered. The 5-yr loco-regional relapse-free and distant metastasis-free survival rates were 91.7% and 90.9%, respectively. On univariate analysis, age, T stage and the absence of bcl-2 & estrogen receptor (ER) expression were associated with loco-regional relapse-free survival. When incorporating these variables into Cox proportional hazard model, only bcl-2(-)/ER(-) phenotype was an adverse prognostic factor (P=0.018). As for the distant metastasis-free survival, age, T stage, and p53 expression were significant on univariate analysis. However, p53 expression was the only prognosticator on multivariate analysis (P=0.009). A bcl-2(-)/ER(-) phenotype and p53 expression are useful molecular markers predicting loco-regional relapse-free and distant metastasis-free survival, respectively, in patients treated with breast conserving surgery and radiotherapy.

Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b&c

PURPOSE

To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT).

PATIENTS AND METHODS

The present analysis included 1 000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue microarray sections were stained with immunohistochemistry for p53 and BCL2. Median potential follow-up was 17 years. Clinical endpoints were locoregional recurrence (LRR), distant metastases (DM), overall mortality, and overall survival (OS). Statistical analyses included Kappa statistics, chi(2) or exact tests, Kaplan-Meier probability plots, Log-rank test, and Cox univariate and multivariate regression analyses.

RESULTS

p53 accumulation was not significantly associated with increased overall mortality, DM or LRR probability in univariate or multivariate Cox regression analyses. Kaplan-Meier probability plots showed reduced OS and improved DM and LRR probabilities after PMRT within subgroups of both p53 negative and p53 positive patients. Negative BCL2 expression was significantly associated with increased overall mortality, DM and LRR probability in multivariate Cox regression analyses. Kaplan-Meier probability plots showed a significantly improved overall survival after PMRT for the BCL2 positive subgroup, whereas practically no survival improvement was seen after PMRT for the BCL2 negative subgroup. In multivariate analysis of OS, however, no significant interaction was found between BCL2 and randomization status. Significant reductions in LRR probability after PMRT were recorded within both the BCL2 positive and BCL2 negative subgroups.

CONCLUSION

p53 was not associated with survival after radiotherapy in high-risk breast cancer, but BCL2 might be.

Survivin expression in breast carcinoma: correlation with apoptosis and prognosis

BACKGROUND

Survivin is a novel inhibitor of apoptosis commonly detected in tissues during fetal development and in cancer, but not usually in normal tissues. It has been suggested that the expression of this protein may be of prognostic significance in gastric, colorectal, and bladder carcinomas. We assessed survivin expression in breast carcinomas correlating results with expression of other antiapoptotic (bcl-2, bcl-x) and proapoptotic (bax) markers, with prognostic parameters, and with prognosis.

DESIGN

Paraffin-embedded sections of 37 breast carcinomas were immunostained for survivin, bcl-2, bcl-x, and bax. Expression was evaluated in normal breast tissue and carcinoma, nuclei and cytoplasm, as intensity (0 to 3+), and percentage of positive cells.

RESULTS

Survivin expression was noted in 30 (81%) of breast carcinomas, and in normal breast tissue, in nuclei, and cytoplasm. There was a significant correlation (P=0.022) between survivin and bcl-x expression; survivin and bcl-x tended to correlate with overall survival (P=0.072 and 0.075, respectively), but not with disease-free survival (P=0.19 and 0.18, respectively). There was no correlation of survivin with bcl-2 or bax expression, or with other prognostic parameters (age, tumor size, histologic type, histologic grade, nodal status, and tumor stage) (P>0.05).

CONCLUSION

The majority (81%) of breast carcinomas show survivin expression which correlates with bcl-x, another antiapoptotic marker, and both markers tend to correlate with prognosis.

High expression of maspin is associated with early tumor relapse in breast cancer

Maspin is a serine protease inhibitor with tumor suppressor activity. Maspin can suppress tumor growth and metastasis in vivo and tumor cell motility and invasion in vitro. Maspin also modulates apoptosis of tumor cells, possibly by modulating the expression of the B-cell lymphoma-2 family member. p53 regulates the expression of the tumor suppressor gene maspin. Breast cancer is known for its propensity to recur even after decades. The biology behind this phenomenon of tumor dormancy is poorly understood. This study was conducted to clarify the role of maspin and B-cell lymphoma-2 in early and late recurring breast cancer. The expression of maspin, B-cell lymphoma-2, p53, and estrogen receptor was studied by immunohistochemistry in 73 primary breast cancers and in their metastatic relapses detected within 2 years, or 5 or 10 years after primary surgery. The cytoplasmic expression of maspin was significantly higher in the primary tumors of the early metastasizing breast cancers (first tumor relapse within 2 years) and also in their metastases compared to late metastasizing cancers. An opposite activity was observed in the expression of B-cell lymphoma-2. The level of B-cell lymphoma-2 staining was lower in the early relapsing cancers and significantly lower in their metastases, compared to tumors which metastasized 5 or 10 years after primary surgery. High cytoplasmic expression of maspin and low expression of B-cell lymphoma-2 in primary breast cancer predict early tumor relapse.

Expression of bcl-2 in breast cancer: correlation with clinicopathological characteristics and survival

Breast cancer is the most common malignancy in women. It is an immensely heterogeneous disease, characterised by a broad variety of clinical development. The research in recent years has focused on finding new markers of prognosis. This study investigates the role of expression of the bcl-2 protein in breast cancer. We analysed bcl-2 expression in 57 women with primary breast carcinoma who were treated with neoadjuvant (primary) chemotherapy, followed by a surgical procedure. The bcl-2 expression was correlated with other clinicopathological characteristics of the tumour- histological grade, stage, expression of hormonal receptors, proliferation rate, and with the survival of the patients. No significant association of bcl-2 expression with either overall survival or disease free survival was found.

TW-37, a small-molecule inhibitor of Bcl-2, inhibits cell growth and invasion in pancreatic cancer

Bcl-2 family of proteins plays critical roles in human cancers, including pancreatic cancer, suggesting that the discovery of specific agents targeting Bcl-2 family proteins would be extremely valuable for pancreatic cancer therapy. We have previously reported the synthesis and characterization of TW-37, which seems to be a negative regulator of Bcl-2. In this investigation, we tested our hypothesis whether TW-37 could be an effective inhibitor of cell growth, invasion and angiogenesis in pancreatic cancer cells. Using multiple cellular and molecular approaches such as MTT assay, apoptosis enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction, Western blotting, electrophoretic mobility shift assay for measuring DNA binding activity of NF-kappaB, migration, invasion and angiogenesis assays, we found that TW-37, in nanomolar concentrations, inhibited cell growth in a dose- and time-dependent manner. This was accompanied by increased apoptosis and concomitant attenuation of NF-kappaB, and downregulation of NF-kappaB downstream genes such as MMP-9 and VEGF, resulting in the inhibition of pancreatic cancer cell migration, invasion and angiogenesis in vitro and caused antitumor activity in vivo. From these results, we conclude that TW-37 is a potent inhibitor of progression of pancreatic cancer cells, which could be due to attenuation of Bcl-2 cellular signaling processes. Our findings provide evidence showing that TW-37 could act as a small-molecule Bcl-2 inhibitor on well-characterized pancreatic cancer cells in culture as well as when grown as tumor in a xenograft model. We also suggest that TW-37 could be further developed as a potential therapeutic agent for the treatment of pancreatic cancer.

Prognostic value of Bcl-2 in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy

We have analyzed the predictive/prognostic value of Bcl-2 protein in breast cancer patients treated with neoadjuvant chemotherapy. One hundred and ten patients were submitted to two different chemotherapeutic regimens: a) 5-fluorouracil, adriamycin or epirubicin, and cyclophosphamide (FAC/FEC) during 2-6 cycles before surgery and 3 or 4 additional cycles of FAC/FEC after surgery (n=40) and b) doxorubicin (D) 75 mg/m(2) or epirubicin (E) 120 mg/m(2) during 4 cycles before surgery, and 6 cycles of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) after surgery (n=70). Bcl-2 expression, evaluated by immunohistochemistry, did not change significantly after chemotherapy and was not related to clinical/pathological response. In FAC/FEC group, Bcl-2 positive expression after chemotherapy correlated with better disease free survival (DFS) and overall survival (OS) (P=0.008 and P=0.001). In D/E group, Bcl-2 also correlated with better DFS and OS (P=0.03 and P=0.054) in the post-chemotherapy biopsies. An unusual nuclear localization of Bax was observed in some biopsies, but this localization did not correlate with the tumor response or outcome of the patients. We found that a high Bcl-2 expression had no predictive value but had prognostic value in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy.

Assessing interactions between mdm-2, p53, and bcl-2 as prognostic variables in muscle-invasive bladder cancer treated with neo-adjuvant chemotherapy followed by locoregional surgical treatment

BACKGROUND

Tumor proliferation and apoptosis may be influenced by the mdm-2 gene product, which can block the antiproliferative effects of p53. bcl-2, one of a family of related genes that regulates the apoptotic pathway, exhibits a negative influence. Both individual and cooperative effects of these gene products may affect the biological behavior of primary bladder cancers and long-term outcome to standard therapy.

METHODS

This study retrospectively evaluated the association with survival of mdm-2, p53, and bcl-2 expression in 59 patients with muscle-invasive, node-negative transitional cell carcinoma (TCC) treated with neo-adjuvant chemotherapy followed by locoregional surgery. Each marker was defined as an altered phenotype if >or=20% malignant cells in the primary tumor exhibited staining; normal or minimal expression was defined as <20% cells exhibiting staining.

RESULTS

Altered mdm-2, p53, and bcl-2 expression was observed in 37%, 54%, and 46% of patients, respectively. In single marker analysis, altered p53 expression correlated with long-term survival (P = 0.05) but mdm-2 (P = 0.42) or bcl-2 (P = 0.17) did not. In the multiple-marker analysis, a prognostic index simultaneously assessing mdm-2, p53, and bcl-2 correlated with survival (P = 0.01). The 5-year survival for patients in which all markers were normally expressed was 54% compared with 25% in those with all three markers aberrantly expressed. Patients with aberrant expression of either one or two markers had an intermediate 5-year survival (49%). There was no association of molecular markers either alone or in combination with pathologic downstaging after neo-adjuvant chemotherapy.

CONCLUSION

The cooperative effects of phenotypes determined by mdm-2, p53, and bcl-2 expression may predict survival in patients with muscle-invasive TCC of the bladder.