Bcl-2 expression and triple negative profile in breast carcinoma

Clinicopathological importance of Bcl-2 and p53 in postmenopausal triple-negative breast carcinoma and association with age

Appropriate biomarkers are required to predict the clinical outcome of triple-negative breast cancer (TNBC). In this study, we focused on the clinical importance of two representative tumor-associated proteins, Bcl-2 and p53. Bcl-2 expression is usually related to estrogen receptor expression and a favorable outcome in breast cancer. TNBC has been reported to show a high frequency of p53 positivity suggesting TP53 mutations. The expressions of Bcl-2 and p53 were immunohistochemically examined in TNBC involving two age groups of postmenopausal women (≥75 y/o, n = 75; 55-64 y/o, n = 47), who underwent surgery without neoadjuvant therapy. We examined their associations with each other, or with clinicopathological factors including the outcome. Bcl-2 expression was inversely correlated with androgen receptor, apocrine morphology, and p53 expressions, and was an independent predictor of a poor outcome in total or in younger women. p53 positivity was associated with a more favorable outcome than p53 negativity in the younger group. In combined analyzes, none of the twenty Bcl-2-negative/p53-positive cases in the younger group exhibited recurrence, resulting in the independent favorable predictive value of Bcl-2-negative/p53-positive. The anti-apoptotic nature of Bcl-2 may be apparent in TNBC. The excellent outcome of Bcl-2-negative/p53-positive cases in the younger group warrants further combined investigation of Bcl-2/p53 in TNBC.

Epstein-Barr virus in breast carcinoma and in triple negative cases impact on clinical outcomes

BACKGROUND

The contribution of viral infection in tumors pathogenesis has currently attracted attention. Epstein-Barr virus is an infectious agent involved in numerous human malignancies, including breast cancer. Although, their prognostic impact in breast tumor is rarely investigated. Therefore, we sought in our study to evaluate the prevalence of EBV in Tunisian breast carcinoma and to examine their potential association with clinicopathological features and overall survival.

METHODS

Our retrospective study included 100 formalin fixed paraffin embedded samples from Tunisian breast carcinoma. EBV infection was evaluated by immunohistochemical analysis, using monoclonal antibody against latent membrane protein 1 (LMP-1) and polymerase chain reaction. A subset of PCR positive specimens was subjected to in situ hybridization for the detection of EBER expression. Biomarker's expression was evaluated by immunohistochemistry method. Statistical analysis was also explored.

RESULTS

The expression status of ER, PR and HER2 was 81%, 71.4% and 33.7% respectively. The triple negative profile was present in 10.84% of cases. LMP-1 expression was negative in all breast cancer specimens. PCR assay showed that 44% of patients were positive for EBV genome. None of the 15 PCR positive cases showed positive results for EBV by ISH. According to the molecular phenotype, there was a statistically significant difference in EBV DNA prevalence between breast cancer subgroups including TN (67%), Lum B (64%), HER2 + (50%) and Lum A (30%). Bivariate analysis showed that EBV DNA was significantly associated with HER2 + (p = 0.035), tumor size (p = 0.018) and high SBR grade (p = 0.009). Multiple logistic regression analysis confirms the positive correlation of EBV with tumor size (p = 0.048) and SBR grade (p = 0.042). Kaplan-Meier analysis showed that patients with EBV+ had significantly shorter overall survival than those with EBV- (p = 0.032).

CONCLUSIONS

Our study demonstrated the presence of EBV DNA in Tunisian breast carcinoma. EBV DNA was associated with aggressive features and poor overall survival. Further investigations will be required in large samples size to clarify the potential role of EBV in breast tumor progression.

Prognostic value of circulating Bcl-2 and anti-p53 antibodies in patients with breast cancer: A long term follow-up (17.5 years)

BACKGROUND

Apoptosis inhibition is a major tumorigenic factor. Bcl-2 dysregulation and TP53 mutation status, which may correlate with autoantibody generation, contribute to impaired apoptosis.

OBJECTIVE

This study aimed to investigate the prognostic value of circulating Bcl-2 and anti-p53 antibodies (p53Abs) in a 17.5-year follow-up of breast cancer patients. We also analyzed the correlations of Bcl-2 and p53Abs with various clinicopathological parameters in order to assess their impact on tumor aggressiveness.

METHODS

Serum Bcl-2 and p53Abs levels were analyzed by the enzyme-linked immunosorbent assay (ELISA) in 82 patients with invasive breast cancer and twenty individuals without malignancy.

RESULTS

Serum Bcl-2 and p53Abs levels in breast cancer patients were significantly higher than those in controls. Patients with high levels of Bcl-2 (cut-off 200 U/ml) had a poorer prognosis (17.5-year survival) than those with lower Bcl-2 values. In combined analysis the subgroup of patients with elevated p53Abs (cut-off 15 U/ml) and elevated Bcl-2 (cut-offs 124 U/ml and 200 U/ml) had the worse prognosis in 17.5-year survival. In correlation analysis p53Abs and Bcl-2 were associated with unfavorable clinicopathological parameters.

CONCLUSIONS

Our results suggest that breast cancer patients with high serum levels of p53Abs and Bcl-2 present an especially unfavorable group in a long follow-up.

MicroRNA-615-5p regulates the proliferation and apoptosis of breast cancer cells by targeting HSF1

Breast cancer, which commonly occurs in the epithelium of the mammary gland, is a malignant tumor. MicroRNAs are involved in various cancer-associated processes, and microRNA-615-5p has been identified to be decreased in the pathological tissues from patients with breast cancer. In the present study, the possible mechanism of microRNA-615-5p in the progression of breast cancer was investigated in order to identify potential novel targets for clinical treatment. Heat shock factor 1 (HSF1) was identified as a predictive target gene of microRNA-615-5p using TargetScan analysis. The expression levels of microRNA-615-5p and its target gene, HSF1, were measured in breast cancer tissues and normal adjacent tissues. Additionally, the effects of microRNA-615-5p on MCF-7 breast cancer cell growth and apoptosis were examined. Furthermore, the interaction between HSF1 and microRNA-615-5p was investigated by a dual luciferase gene reporter assay. The expression levels of HSF1 were measured following transfection with microRNA-615-5p or pcDNA3.1-HSF1. Finally, the expression levels of proliferation- and apoptosis-associated factors such as B-cell lymphoma 2 (Bcl-2), cyclin D1, proliferating cell nuclear antigen (PCNA) and bcl-2-like protein 4 (Bax) were determined. The results demonstrated that lower microRNA-615-5p expression and higher HSF1 mRNA expression were present in tumor tissues compared with adjacent tissues (P<0.01). HSF1 was verified as a direct target of microRNA-615-5p using the dual luciferase gene reporter assay. In comparison with untransfected control and mimic-transfected negative control (NC) cells, MCF-7 cells transfected with microRNA-615-5p mimics exhibited reduced cell proliferation and increased apoptosis (P<0.01). However, the overexpression of HSF1 using a vector reversed the suppression of HSF1 induced by microRNA-615-5p mimics (P<0.01). The mRNA and protein expression levels of Bax were significantly increased, whereas those of Bcl-2, cyclin D1 and PCNA were decreased in the cells transfected with microRNA-615-5p mimics compared with the control and NC cells (P<0.01). Collectively, the present study indicated that microRNA-615-5p may mediate the progression of breast cancer by targeting HSF1.

Prognostic Value of BCL2 in Women Patients with Invasive Breast Cancer

Background: Breast cancers are heterogeneous, making it essential to recognize several biomarkers for cancer outcome predictions especially in young women where the classical prediction parameters are not suitable. The goal from this study is to evaluate the impact of B cell lymphoma 2 (BCL2), P53 and Ki-67 proteins expression on survival in young women patients with invasive ductal carcinoma. Patients and methods: Samples and clinical data from 238 patients were collected between 2003 and 2017. They were selected according to 2 criteria: age ≤40 years old and most of them are affected by an Invasive Ductal Carcinoma. We evaluated BCL2, P53 and ki-67 expression by immunochemistry test, and then we assessed correlations of these biomarkers expression with patient’s clinicopathological characteristics and survival. Results: Triple negative breast cancer group showed a high frequency among our cohort but we emphasize an almost equitable distribution among all molecular groups. Contrary to other studies which reported that luminal A was correlated with better prognosis, our analysis demonstrated that luminal A is correlated with the Scarff, Bloom and Richardson (SBR) grading 2 or SBR grading 3. To better investigate the prognosis, we analyze three biomarkers known by their impact on physiopathology behavior on breast cancer BCL2, ki-67and P53. BCL2 is the more relevant one, it was correlated with molecular subtypes (p=0.0012) and SBR grading (p=0.0016). BCL2 seems to be the good prognostic biomarker related to survival (p=0.004) with a protective role among patients when endocrine therapy is not provided and Lymph Node (LN) involvement is positive (p=0.021, p=0.000 respectively). Conclusions: The classical prognostic parameters based mainly on the molecular classification in breast cancer seem insufficient in the case of young women. BCL2 protein expression analysis provides a better prognostic value. BCL2 should be clinically associated in current practice when young women specimens are diagnosticated.

MMP-1 is overexpressed in triple-negative breast cancer tissues and the knockdown of MMP-1 expression inhibits tumor cell malignant behaviors in vitro

Matrix metalloproteinase 1 (MMP-1) is a member of the zinc-dependent endopeptidase family, which cleaves the extracellular matrix. The present study investigated the functional role of MMP-1 in breast cancer ex vivo and in vitro in order to determine the underlying molecular mechanisms. The levels of MMP-1 were analyzed in 99 breast cancer specimens using immunohistochemistry and western blotting. A stable short hairpin RNA (shRNA) knockdown of MMP-1 expression was performed in MCF-7 and MDA-MB-231 breast cancer cells, and the effects were examined using MTT and colony formation assays, as well as migration and invasion assays, while western blotting was used to detect the activation of intracellular signaling. The MMP-1 protein was more highly expressed in triple-negative breast cancer tissues than in estrogen receptor(+) and human epidermal growth factor 2 receptor(3+) breast cancer tissues (P<0.05). Furthermore, the MMP-1 levels were significantly higher in the tumor and tumor stromal cells of lymph node metastatic breast cancer tissues than in those of non-metastatic tissues. The knockdown of MMP-1 expression in MCF-7 and MDA-MB-231 cells using MMP-1 shRNA significantly inhibited cell proliferation, migration and invasion, and the expression of the Myc proto-oncogene protein, phosphorylated and total RAC-α serine/threonine-protein kinase 1, and B-cell lymphoma 2, but increased the protein levels of apoptosis regulator BAX and caspase 3. In conclusion, the data suggest that MMP-1 serves an important role in breast cancer development and metastasis. Future studies should assess MMP-1 as a prognostic marker for patients with breast cancer and its inhibition as a novel strategy for controlling breast cancer.

Potential Diagnostic and Therapeutic Applications of Oligonucleotide Aptamers in Breast Cancer

Breast cancer is one of the most common causes of cancer related deaths in women. Currently, with the development of early detection, increased social awareness and kinds of treatment options, survival rate has improved in nearly every type of breast cancer patients. However, about one third patients still have increased chances of recurrence within five years and the five-year relative survival rate in patients with metastasis is less than 30%. Breast cancer contains multiple subtypes. Each subtype could cause distinct clinical outcomes and systemic interventions. Thereby, new targeted therapies are of particular importance to solve this major clinical problem. Aptamers, often termed “chemical antibodies”, are functionally similar to antibodies and have demonstrated their superiority of recognizing target with high selectivity, affinity and stability. With these intrinsic properties, aptamers have been widely studied in cancer biology and some are in clinical trials. In this review, we will firstly discuss about the global impacts and mechanisms of breast cancer, then briefly highlight applications of aptamers that have been developed for breast cancer and finally summarize various challenges in clinical translation of aptamers.

Bcl-2 antigen expression in luminal A and triple-negative breast cancer

Biomarkers for the prognosis of breast cancer have been routinely used in clinical practice, including the expression of hormone receptors, Ki-67 and HER-2. More recently, Bcl-2 has been recognized as an important prognostic factor in breast cancer, although controversies persist with respect to the significance of its expression. The aim of the present study was to evaluate Bcl-2 antigen expression in luminal A and triple-negative breast cancer. Sixty women with invasive ductal carcinoma were included in the study and divided into two groups: Group A (luminal A) and Group B (triple-negative), with 30 cases in each group. Immunohistochemistry was performed on tissue sections to evaluate Bcl-2 antigen expression. Fisher's exact test was used to compare the proportions of cases with cells expressing Bcl-2 between the two subtype cancer groups, with statistical significance being established at p < 0.05. The number of cases with cells expressing Bcl-2 in Groups A and B was 26 (86.7%) and 12 (40.0%), respectively (p < 0.0003). In the present study, the expression of the anti-apoptotic protein Bcl-2 was greater in luminal A breast cancer tissue samples compared to triple-negative breast cancer.

Anti-Metastatic Effect of Dehydrocorydaline on H1299 Non-Small Cell Lung Carcinoma Cells via Inhibition of Matrix Metalloproteinases and B Cell Lymphoma 2

Though Dehydrocorydaline, an alkaloid isolated from Corydalis turtschaninovii tuber, was known to have anti-coronary artery disease, anti-inflammatory, apoptotic, anti-allergic, anti-acetylcholinesterase, and antitumor effects, the underlying anti-metastatic mechanism of Dehydrocorydalin was never elucidated in lung cancer cells so far. Thus, in the present study, the anti-metastatic effect of Dehydrocorydaline was examined in non-small cell lung carcinoma (NSCLC) cells, mainly targeting matrix metalloproteinases (MMPs) and B cell lymphoma-2 (Bcl-2) signaling. Here, Dehydrocorydaline exerted weak cytotoxicity and attenuated the protein expression of Bcl-2 and activated Bax in a concentration-dependent manner in NSCLC cells, such as A549, H460, H1299, and H596 cells. Also, Dehydrocorydaline suppressed the migration of H1299 cells by wound healing assay and transwell migration assay. Consistently, Dehydrocorydaline attenuated mRNA and protein levels of MMP7 and MMP9 as metastasis biomarkers in H1299 cells by quantitative reverse transcription polymerase chain reaction. Of note, Bcl-2 overexpression reduced the cytotoxic and anti-metastatic effects of Dehydrocorydaline on pCDNA-Bcl-2 transfected H1299 cells. Overall, our findings provide scientific evidence that Dehydrocorydaline exerts anti-metastatic potential via suppression of MMPs and Bcl-2 signaling in NSCLC cells. Copyright © 2017 John Wiley & Sons, Ltd.

BCL2 as a Subtype-Specific Prognostic Marker for Breast Cancer

PURPOSE

B-cell lymphoma 2 (BCL2) is an antiapoptosis protein and an important clinical breast cancer prognostic marker. As the role of BCL2 is dependent on the estrogen receptor (ER) status, this effect might differ according to molecular subtypes. The aim of this study was to evaluate the relationship between the prognostic outcomes and BCL2 expression among the molecular subtypes.

METHODS

We retrieved the data of 1,356 patients who were newly diagnosed with malignant breast cancer between November 2006 and November 2011. Immunohistochemistry was used to measure ER, progesterone receptor, human epidermal growth factor receptor 2 (HER2), Ki-67, and BCL2 expression. We classified breast cancer into five molecular subtypes based on the 13th St. Gallen International Expert Consensus, including luminal A, luminal B (HER2-negative), luminal B (HER2-positive), HER2-overexpression, and triple-negative subtypes. We analyzed the clinicopathological features and assessed the correlation between BCL2 expression and clinical outcomes, such as relapse-free survival (RFS) and disease-specific survival (DSS) according to the five molecular subtypes.

RESULTS

A total of 605 cases of breast cancer (53.8%) showed BCL2 expression. BCL2-positive expression was associated with young age (<50 years, p=0.036), lower histological grade (p<0.001), low Ki-67 level (<14%, p<0.001), hormone receptor positivity (p<0.001), HER2 negativity (p<0.001), luminal breast cancer (p<0.001), and low recurrence rate (p=0.016). BCL2-positive expression was also associated with favorable 5-year RFS (p=0.008, 91.4%) and DSS (p=0.036, 95.6%) in all the patients. BCL2-positive expression in luminal A breast cancer resulted in significantly favorable 5-year RFS and DSS (p=0.023 and p=0.041, respectively). However, BCL2 expression was not associated with the prognosis in the other subtypes.

CONCLUSION

The prognostic role of BCL2 expression in breast cancer is subtype-specific. BCL2 expression differs according to the molecular subtype and is a good prognostic marker for only luminal A breast cancer.

What common biomarkers characterize a triple-negative profile in breast cancer?

Triple-negative breast cancers are not a homogeneous subgroup. There is substantial intra-subgroup diversity in tumor biology, prognosis and treatment sensitivity. Then, these triple-negative phenotype (TNP) groups, having specific features, can be again divided into subclasses based on an added immunohistochemical markers. The challenge in treating TNP breast cancers is that they are not responsive to antiestrogens or trastuzumab secondary to negative receptor status, and as a result have a poor prognosis. Therefore, the presence or absence of supplementary markers could help predict which therapies are best suited for patients based on the pattern that their disease markers show. In this review, we will recapitulate the major supplementary biomarkers related to triple-negative breast cancer, which could give new therapeutic options.

Anti-tumor activity of folate targeted biodegradable polymer-paclitaxel conjugate micelles on EMT-6 breast cancer model

BACKGROUND

Paclitaxel (PTX) is a first line chemotherapy drug for breast cancer. There have been few studies reported concerning the therapeutic efficacy of paclitaxel-conjugated polymeric micelles in breast cancer in vivo.

METHODS

Two kinds of PTX conjugate micelles, one of which (M(PTX)) contained 25 wt.% of PTX and the other (M(FA/PTX)) contained 22.5 wt.% of PTX and 1.4 wt.% of folate (FA), were prepared for cell apoptosis and anti-tumor activity evaluation on EMT-6 mice breast cancer models in comparison with 0.9 wt.% saline (control) and equivalent PTX. Cell apoptosis was analyzed by flow cytometry. Breast tumors were examined histologically with H&E staining and immunohistochemically by examining Bax and Bcl-2 expression. The survival status of tumor-bearing mice with different treatments was also examined.

RESULTS

On day 5 of the drug administration, the average tumor masses were 0.49, 0.33, 0.22, and 0.18 g for the control, PTX, M(PTX) and M(FA/PTX) groups, respectively. The inhibition rates of tumor growth calculated for the three drug groups were 32.6%, 51.6% and 62.3%, respectively. The percentage of cell apoptosis based on flow cytometry was 1.0%, 36.6%, 55.9% and 66.1%, respectively, which showed statistically significant differences (p<0.05) between three drug groups and the control group. Bcl-2 expression of PTX and M(FA/PTX) groups was lower than control group (p<0.05). Bax expression of drug groups was higher than control group (p<0.05). At an equivalent paclitaxel dose of 26.7 mg/kg, the average survival time was 33 days, 31 days, 34 days and 42 days, respectively (p<0.05).

CONCLUSION

The M(FA/PTX) have better anti-tumor activity and are promising in treatment of human breast cancers.

Apoptosis Phenomena in Squamous Cell Carcinomas and Adenocarcinomas of the Uterine Cervix

To investigate the relationship between apoptosis and histologic types in invasive squamous cell carcinoma and adenocarcinoma of the uterine cervix. The present study involved the assessment of surgical specimens from 74 women with cervical carcinomas FIGO stage IB1 (54 squamous cell carcinomas and 20 adenocarcinomas). The study samples were obtained from selected paraffin blocks containing specimens from patients submitted to surgical procedures. The respective medical charts of patients were reviewed and epidemiologic, clinical and disease-related data were collected. Cervical specimens were assessed by the immunohistochemistry technique using the Bcl-2 protein as a marker. The reactions were considered positive when the cells became stained in brown color. Bcl-2 positive cells were counted in 10 fields under a high magnification (400x) using light microscopy, in the slides area containing squamous carcinoma and adenocarcinoma of the cervix. The total cell count was expressed as the number of positive Bcl-2 cells per mm(2). No significant difference in the number of cells marked by the Bcl-2 protein was found for the variables age, tumor diameter, angiolymphatic invasion or number of lymph nodes affected. Comparison of the number of cells marked by the Bcl-2 protein in the two histological groups revealed a statistically significant difference, with squamous tumors presenting a greater number of marked cells. Squamous cervical tumors present a greater number of positive Bcl-2 cells per mm(2), suggesting that that the rate of cell death in squamous cell carcinomas of the cervix is lower than in adenocarcinomas.

Estrogen receptor-positive breast cancer molecular signatures and therapeutic potentials (Review)

In this review, the advances in the study of breast cancer molecular classifications and the molecular signatures of the luminal subtypes A and B of breast cancer were summarized. Effective clinical outcomes depend mainly on successful preclinical diagnosis and therapeutic decisions. Over the last few years, the ever-expanding investigations focusing on breast cancer diagnosis and the clinical trials have provided accumulating information on the molecular characteristics of breast cancer. Specifically, among the estrogen receptor (ER)-positive types of breast cancer, the luminal subtype A breast cancer has been shown to exhibit good clinical outcomes with endocrine therapy, whereas the luminal subtype B breast cancer represents the more complicated type, diagnostically as well as therapeutically. Furthermore, even in luminal subtype A breast cancer, the resistance to treatment has become the major limitation for endocrine-based therapy. Accumulating molecular data and further clinical trials may enable more accurate diagnostic and therapeutic decisions. The molecular signatures have emerged as a powerful tool for future diagnosis and therapeutic decisions, although currently available data are limited.

ANALYSIS OF BREAST CANCER PROFILES USING BAYESIAN NETWORK MODELING

Breast cancer is the leading cause of cancer-related death for women in Tunisia and the prognosis of its metastasis remains a major problem for oncologists despite advances in treatment. In this work we use Bayesian networks to develop a decision support system that is based on the modeling of relationships between key signaling proteins and clinical and pathological characteristics of breast tumors and patients. Motivated by the lack of prior information on the parameters of the problem, we use the Implicit inference for the structure and parameter learning. A dataset of 84 Tunisian breast cancer patients was used and new prognosis factors were identified. The system predicts a metastasis risk for different patients by computing a score that is the joint probability of the Bayesian network using parameters estimated on the learning database. Based on the results of the developed system we identified that overexpression of ErbB2, ErbB3, bcl2 as well as of oestrogen and progesterone receptors associated with a low level of ErbB4 was the predominant profile associated with high risk of metastasis.

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.

Outcome of triple-negative breast cancer in patients with or without markers regulating cell cycle and cell death

Purpose

The genes p53 and B-cell lymphoma (bcl)-2 play an important role in regulating the mechanisms of apoptosis. In this paper, we retrospectively applied these factors to our series of triple negative breast cancer (TNBC) patients, in conjunction with an evaluation of the prognostic significance of these factors' influence on TNBC survival rate. Particular focus was placed on the role of bcl-2, p53, Ki-67.

Methods

The study subjects, 94 women with TNBC, were a subset of patients operated at Kosin University Gospel Hospital from January 2000 to December 2005. Chi-squared tests were used for statistical analysis.

Results

Positive staining for cytokeratin (CK)5/6 in 23 cases (24.5%), epidermal growth factor receptor in 15 cases (16.0%), bcl-2 in 26 cases (27.7%), p53 in 55 cases (58.5%) and Ki-67 in 74 cases (78.7%) was determined. Lymph node status, tumor size and expression of CK5/6 or Ki-67 were independent prognostic factors for patients with TNBC.

Conclusion

Markers regulating cell cycle and cell death such as p53 and bcl-2 cannot be used to classify TNBCs into two subtypes with differing disease-free survival. But because our study is small in size, more abundant patient data will be needed to evaluate the factors' predictive role in regulating cell cycle and cell death.

Differential expression of breast cancer-associated genes between stage- and age-matched tumor specimens from African- and Caucasian-American Women diagnosed with breast cancer

Background

Recent studies suggest that the poorer breast cancer outcome observed in African-American women (AAW) may, in part, result from underlying molecular factors. The purpose of this study was to investigate gene expression differences between Caucasian-American women (CAW) and AAW that may contribute to this poorer prognosis.

Methods

The expression of 84 genes involved in breast carcinoma prognosis, response to therapy, estrogen signaling, and tumor aggressiveness was assessed in age- and stage-matched CAW and AAW paraffin-embedded breast cancer specimens. The Wilcoxon–Mann–Whitney Test was used to identify genes with a significant difference in expression between CAW and AAW. To determine if the differentially expressed genes could segregate between the CAW and AAW, we performed semi-supervised principal component analysis (SSPCA).

Results

Twenty genes were differentially expressed between AAW and CAW. SSPCA incorporating these 20 genes segregated AAW and CAW into two distinct groups. AAW were significantly (p < 0.05) more likely to display aberrations in G₁/S cell-cycle regulatory genes, decreased expression of cell-adhesion genes, and low to no expression of ESR1, PGR, ERBB2 and estrogen pathway targets.

Conclusions

The gene expression differences identified between AAW and CAW may contribute to more aggressive disease, resistance to therapy, enhanced metastatic potential and poor clinical outcome. These findings support the hypothesis that breast cancer specimens collected from AAW display distinct gene expression differences compared to similar tissues obtained from CAW. Additional population-based studies are necessary to determine if these gene expression variations contribute to the highly aggressive and treatment-resistant breast cancer phenotype frequently observed in AAW.

Delivery of chemo-sensitizing siRNAs to HER2+-breast cancer cells using RNA aptamers

Human epidermal growth factor receptor 2 (HER2) expression in breast cancer is associated with an aggressive phenotype and poor prognosis, making it an appealing therapeutic target. Trastuzumab, an HER2 antibody-based inhibitor, is currently the leading targeted treatment for HER2(+)-breast cancers. Unfortunately, many patients inevitably develop resistance to the therapy, highlighting the need for alternative targeted therapeutic options. In this study, we used a novel, cell-based selection approach for isolating 'cell-type specific', 'cell-internalizing RNA ligands (aptamers)' capable of delivering therapeutic small interfering RNAs (siRNAs) to HER2-expressing breast cancer cells. RNA aptamers with the greatest specificity and internalization potential were covalently linked to siRNAs targeting the anti-apoptotic gene, Bcl-2. We demonstrate that, when applied to cells, the HER2 aptamer-Bcl-2 siRNA conjugates selectively internalize into HER2(+)-cells and silence Bcl-2 gene expression. Importantly, Bcl-2 silencing sensitizes these cells to chemotherapy (cisplatin) suggesting a potential new therapeutic approach for treating breast cancers with HER2(+)-status. In summary, we describe a novel cell-based selection methodology that enables the identification of cell-internalizing RNA aptamers for targeting therapeutic siRNAs to HER2-expressing breast cancer cells. The future refinement of this technology may promote the widespread use of RNA-based reagents for targeted therapeutic applications.

Immunohistochemistry profiles of breast ductal carcinoma: factor analysis of digital image analysis data

BACKGROUND

Molecular studies of breast cancer revealed biological heterogeneity of the disease and opened new perspectives for personalized therapy. While multiple gene expression-based systems have been developed, current clinical practice is largely based upon conventional clinical and pathologic criteria. This gap may be filled by development of combined multi-IHC indices to characterize biological and clinical behaviour of the tumours. Digital image analysis (DA) with multivariate statistics of the data opens new opportunities in this field.

METHODS

Tissue microarrays of 109 patients with breast ductal carcinoma were stained for a set of 10 IHC markers (ER, PR, HER2, Ki67, AR, BCL2, HIF-1α, SATB1, p53, and p16). Aperio imaging platform with the Genie, Nuclear and Membrane algorithms were used for the DA. Factor analysis of the DA data was performed in the whole group and hormone receptor (HR) positive subgroup of the patients (n = 85).

RESULTS

Major factor potentially reflecting aggressive disease behaviour (i-Grade) was extracted, characterized by opposite loadings of ER/PR/AR/BCL2 and Ki67/HIF-1α. The i-Grade factor scores revealed bimodal distribution and were strongly associated with higher Nottingham histological grade (G) and more aggressive intrinsic subtypes. In HR-positive tumours, the aggressiveness of the tumour was best defined by positive Ki67 and negative ER loadings. High Ki67/ER factor scores were strongly associated with the higher G and Luminal B types, but also were detected in a set of G1 and Luminal A cases, potentially indicating high risk patients in these categories. Inverse relation between HER2 and PR expression was found in the HR-positive tumours pointing at differential information conveyed by the ER and PR expression. SATB1 along with HIF-1α reflected the second major factor of variation in our patients; in the HR-positive group they were inversely associated with the HR and BCL2 expression and represented the major factor of variation. Finally, we confirmed high expression levels of p16 in Triple-negative tumours.

CONCLUSION

Factor analysis of multiple IHC biomarkers measured by automated DA is an efficient exploratory tool clarifying complex interdependencies in the breast ductal carcinoma IHC profiles and informative value of single IHC markers. Integrated IHC indices may provide additional risk stratifications for the currently used grading systems and prove to be useful in clinical outcome studies.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1512077125668949.

Prognostic significance of Bcl-2 in invasive mammary carcinomas: a comparative clinicopathologic study between "triple-negative" and non-"triple-negative" tumors

Bcl-2 is a tumorigenic protein that is expressed in 25% to 50% of breast cancers. Although its expression has been widely accepted as a favorable prognostic marker, its protective mechanism of action remains unclear. "Triple-negative" tumors are an aggressive subgroup known to carry a poor prognosis. Studies documenting prognostic significance of Bcl-2 expression in triple-negative in comparison to non-triple-negative breast cancers are limited. Bcl-2 expression was correlated with tumor size, grade, histologic type, lymphovascular invasion, lymph node status, patients' overall survival, estrogen receptor, progesterone receptor, Her-2, p53, and epidermal growth factor receptor in 124 triple-negative and 458 non-triple-negative tumors. There were significant differences between triple-negative and non-triple-negative tumors in their relationship to Bcl-2 expression (81% versus 29%, respectively) and tumor aggression. As previously reported, in non-triple-negative tumors, Bcl-2 positivity correlated with less aggressive tumors (94% of grade I tumors were Bcl-2+ versus 62% of grade III tumors, P < .011) and overall survival (P = .008). However, the opposite was true in patients with triple-negative tumors, where Bcl-2 positivity was associated with poorer survival (P = .64). In triple-negative tumors, Bcl-2 positivity was not associated with any of the aforementioned parameters except for a lower incidence of lymph node metastasis. Moreover, by Cox regression analysis of all variables, in patients with triple-negative tumors, lymphovascular invasion (P = .009) and Bcl-2 expression (P = .028) were predictors of poor survival. In conclusion, there are major clinicopathologic differences between breast cancer phenotypes. Our results establish the value of using Bcl-2 in prognostic stratification of patients and its potential therapeutic implications in selecting patients for treatment.