In search of triple-negative DCIS: tumor-type dependent model of breast cancer progression from DCIS to the invasive cancer

Molecular subtyping reveals uniqueness of prognosis in breast ductal carcinoma in situ patients with lumpectomy

Background

We aimed to analyse the discrepancy in clinical features and prognosis between molecular subtypes in primary ductal carcinoma in situ (DCIS) patients with lumpectomy.

Methods

Primary DCIS patients were identified from the Surveillance, Epidemiology, and End Results registries database from 2010 to 2017. Based on immunohistochemistry markers of hormone receptor (HR) and human epidermal growth factor receptor-2 (HER2), enrolled DCIS cases were divided into four molecular subtypes, HR-HER2-, HR-HER2+, HR + HER2+, and HR + HER2-. Clinical features and prognosis were compared between molecular subtypes. Radiotherapy (RT) effects on prognosis were also analysed in each molecular subtype.

Results

A total of 5,628 DCIS cases were retrospectively enrolled in this study. HR-HER2-, HR-HER2+, HR+HER2+, and HR+HER2- are 299 (5.3%), 498 (8.8%), 1,086 (19.3%), and 3,745 (66.5%), respectively. HR + HER2- cases have smaller tumor size (72.6%, P < 0.001) and lower grade (23.5%, P < 0.001). Comedo necrosis is more frequent in HR-HER2- (24.4%, P < 0.001) and HR-HER2+ DCIS cases (24.3%, P < 0.001). In univariate analyses, HR-HER2+ cases have significantly higher ipsilateral breast event (IBE) recurrence than HR+HER2- cases (P = 0.010). HR-HER2- cases show higher disease-specific mortality than HR+HER2+ cases (P = 0.021). In high-risk DCIS cases, RT reduces the absolute 5-year IBE incidence by 1.3%, 0.7%, 1.9%, and 2.6%, respectively in HR-HER2-, HR-HER2+, HR+HER2+, and HR+HER2- cases, respectively.

Conclusion

In this population-based study, DCIS cases have diverse clinical and prognostic features for different molecular subtypes. Adjusting treatment strategies according to DCIS molecular subtypes is worth advancing.

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HR-HER2+ DCIS shows the highest proportion of high-risk cases. HR + HER2- DCIS shows lowest proportion of high-risk cases.

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HR-HER2+ DCIS shows high risk of IBE recurrence. The DSmortality has no differences among four molecular subtypes.

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RT lowered the probability of IBE incidence in high-risk cases for each molecular subtype of DCIS.

Stem Cell Marker Aldehyde Dehydrogenase 1A1 Expression in Triple-negative Breast Carcinoma

Background: Increasing evidence has proposed that tumor contains tumor initiating cells or cancer stem cells (CSCs) are responsible for its progression and relapse. Aldehyde dehydrogenase 1A1 (ALDH1A1) has recently been identified as a marker for cancer stem cells in some human malignancies including breast cancer.Triple negative breast carcinomas (TNBCs) are group of primary breast tumors with aggressive clinical behavior that have no targeted therapy at present. Aim: The assessment of immunohistochemical expression of ALDH1A1 in triple negative breast carcinoma and its correlation with the clinicopathological features of TNBC. Material and Methods: This study consisted of 60 cases of TNBC. Immunohistochemical reactions were carried out by using ALDH1A1 monoclonal antibody. A total score of ALDH1A1 expression is obtained by multiplying the score of staining intensity & percentage of stained cells to obtain score ranging from 0 up to 300. Due to the relatively large number of positive cases, a statistical analysis was performed with a negative (score ≤ 10) and positive (score > 10) cutoff [1]. Results: Evaluation of the results of immunostaining for ALDH1A1 showed 88.3% of totalcases (53 cases) having a positive cytoplasmic reactivity. Statistical analysis for a possible correlation between ALDH1A1 expression and prognostic clinicopathological parameters; age, size, tumor grade, histologic subtypes, lymphovascular invasion, intraductal components, tumor infiltrating lymphocytes and TNM stage grouping revealed a non-significant correlation. Conclusion: ALDH1A1 couldn’t be used solely as a diagnostic or prognostic marker In TNBCs. Further research combining with other biomarkers and with a greater number of patients is necessary to confirm the role of ALDH1A1 in TNBC. Key words: Cancer stem cells (CSCs), Aldehyde dehydrogenase 1A1 (ALDH1A1), Triple Negative Breast   cancer (TNBC).

Ajuba Overexpression Promotes Breast Cancer Chemoresistance and Glucose Uptake through TAZ-GLUT3/Survivin Pathway

The LIM protein Ajuba has been implicated in the development of human cancers. To date, its expression pattern and biological significance in breast cancers (BC) have not been fully investigated. In the current study, we examined Ajuba protein levels in 93 invasive ductal carcinoma specimens by immunohistochemistry. The Ajuba expression level was elevated in breast cancer tissue compared with normal tissue. Ajuba overexpression is correlated with advanced tumor-node-metastasis (TNM) stage, positive node status, and adverse patient outcomes. The Ajuba protein level was also higher in BC cell lines compared to normal breast epithelial cell line MCF-10A. Ectopically expressed Ajuba in MCF-7 cells stimulated in vitro and in vivo cell growth, invasion, cell cycle progression, and decreased paclitaxel-induced apoptosis. RNA-sequencing (RNA-seq) followed by gene set enrichment analysis (GSEA) analysis showed that Ajuba overexpression regulated the Hippo signaling pathway. Ajuba overexpression also increased glucose uptake and increased expression of TAZ, GLUT3, and Survivin. TAZ knockdown abolished the role of Ajuba on GLUT3 and Survivin induction. The ChIP assay showed that TEAD4, a major TAZ binding transcription factor, could bind to the GLUT3 and Survivin promoter regions. In conclusion, our data demonstrated that elevated Ajuba expression is correlated with poor BC prognosis and regulated malignant behavior through TAZ-GLUT3/Survivin signaling in BC cells.

Comparable cancer-relevant mutation profiles in synchronous ductal carcinoma in situ and invasive breast cancer

Background

Ductal carcinoma in situ (DCIS) comprises a diverse group of preinvasive lesions in the breast and poses a considerable clinical challenge due to lack of markers of progression. Genomic alterations are to a large extent similar in DCIS and invasive carcinomas, although differences in copy number aberrations, gene expression patterns, and mutations exist. In mixed tumors with synchronous invasive breast cancer (IBC) and DCIS, it is still unclear to what extent invasive tumor cells are directly derived from the DCIS cells.

Aim

Our aim was to compare cancer‐relevant mutation profiles of different cellular compartments in mixed DCIS/IBC and pure DCIS tumors.

Methods and results

We performed targeted sequencing of 50 oncogenes in microdissected tissue from three different epithelial cell compartments (in situ, invasive, and normal adjacent epithelium) from 26 mixed breast carcinomas. In total, 44 tissue samples (19 invasive, 16 in situ, 9 normal) were subjected to sequencing using the Ion Torrent platform and the AmpliSeq Cancer Hotspot Panel v2. For comparison, 10 additional, pure DCIS lesions were sequenced.

Across all mixed samples, we detected 23 variants previously described in cancer. The most commonly affected genes were TP53, PIK3CA, and ERBB2. The PIK3CA:p.H1047R variant was found in nine samples from six patients. Most variants detected in invasive compartments were also found in the corresponding in situ cell compartment indicating a clonal relationship between the tumor stages. A lower frequency of variants were observed in pure DCIS lesions.

Conclusion

Similar mutation profiles between in situ and invasive cell compartments indicate a similar origin of the two tumor stages in mixed breast tumors. The lower number of potential driver variants found in pure DCIS compared with the in situ cell compartments of mixed tumors may imply that pure DCIS is captured earlier in the path of progression to invasive disease.

Contrasting DCIS and invasive breast cancer by subtype suggests basal-like DCIS as distinct lesions

Ductal carcinoma in situ (DCIS) is a non-invasive type of breast cancer with highly variable potential of becoming invasive and affecting mortality. Currently, many patients with DCIS are overtreated due to the lack of specific biomarkers that distinguish low risk lesions from those with a higher risk of progression. In this study, we analyzed 57 pure DCIS and 313 invasive breast cancers (IBC) from different patients. Three levels of genomic data were obtained; gene expression, DNA methylation, and DNA copy number. We performed subtype stratified analyses and identified key differences between DCIS and IBC that suggest subtype specific progression. Prominent differences were found in tumors of the basal-like subtype: Basal-like DCIS were less proliferative and showed a higher degree of differentiation than basal-like IBC. Also, core basal tumors (characterized by high correlation to the basal-like centroid) were not identified amongst DCIS as opposed to IBC. At the copy number level, basal-like DCIS exhibited fewer copy number aberrations compared with basal-like IBC. An intriguing finding through analysis of the methylome was hypermethylation of multiple protocadherin genes in basal-like IBC compared with basal-like DCIS and normal tissue, possibly caused by long range epigenetic silencing. This points to silencing of cell adhesion-related genes specifically in IBC of the basal-like subtype. Our work confirms that subtype stratification is essential when studying progression from DCIS to IBC, and we provide evidence that basal-like DCIS show less aggressive characteristics and question the assumption that basal-like DCIS is a direct precursor of basal-like invasive breast cancer.

Ductal Carcinoma In Situ of the Breast: Perspectives on Tumor Subtype and Treatment

Objective

To evaluate ductal carcinoma in situ (DCIS) characteristics and the effect of different treatment strategies. Patients and Methods. Using data with known hormone receptor (HoR) and human epidermal growth factor receptor 2 (HER2) status obtained by the Surveillance, Epidemiology, and End Results (SEER) program from 2010-2014, the study was conducted to investigate tumor subtype-specific differences in various characteristics, overall survival (OS), and breast cancer-specific mortality (BCSM).

Results

A total of 3415 patients with DCIS were eligible. Compared with HoR+/HER- subgroup, patients with triple-negative (TN) and HoR-/HER+ were commonly higher in grade, larger in size, and tended to receive mastectomy (P < 0.05). The multivariate analysis revealed that patients with TN were more likely to have a poorer OS and show a higher breast cancer-specific mortality compared with the HoR+/HER- subgroup (P < 0.05). Multivariate analysis on the history of local treatment and surgery showed patients receiving breast-conserving surgery (BCS) plus radiotherapy (R) and BCS plus axillary lymph node dissection was likely to improve OS without affecting breast cancer-specific mortality (P < 0.05).

Conclusion

The results demonstrate that DCIS associated with TN subtype portends poor prognosis. Meanwhile, BCS plus R was a preferable option and resulted in survival rates better than those achieved with mastectomy, and SLNB should be considered as an appropriate assessment of axillary staging in patients with DCIS.

DNA methylation landscape of triple-negative ductal carcinoma in situ (DCIS) progressing to the invasive stage in canine breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer unresponsive to traditional receptor-targeted treatments, leading to a disproportionate number of deaths. Invasive breast cancer is believed to evolve from non-invasive ductal carcinoma in situ (DCIS). Detection of triple-negative DCIS (TN-DCIS) is challenging, therefore strategies to study molecular events governing progression of pre-invasive TN-DCIS to invasive TNBC are needed. Here, we study a canine TN-DCIS progression and investigate the DNA methylation landscape of normal breast tissue, atypical ductal hyperplasia (ADH), DCIS and invasive breast cancer. We report hypo- and hypermethylation of genes within functional categories related to cancer such as transcriptional regulation, apoptosis, signal transduction, and cell migration. DNA methylation changes associated with cancer-related genes become more pronounced at invasive breast cancer stage. Importantly, we identify invasive-only and DCIS-specific DNA methylation alterations that could potentially determine which lesions progress to invasive cancer and which could remain as pre-invasive DCIS. Changes in DNA methylation during TN-DCIS progression in this canine model correspond with gene expression patterns in human breast tissues. This study provides evidence for utilizing methylation status of gene candidates to define late-stage (DCIS and invasive), invasive stage only or DCIS stage only of TN-DCIS progression.

TRIM59 overexpression correlates with poor prognosis and contributes to breast cancer progression through AKT signaling pathway

TRIM59 has been recently implicated in the carcinogenesis of several cancers such as lung cancer, gastric cancer, and bladder cancer. However, its expression pattern and clinical significance has not been investigated in human breast cancer. In the present study, we examined TRIM59 protein expression in 95 cases of breast cancer tissues using immunohistochemistry. We found that TRIM59 was upregulated in 42 out of 95 cases and correlated with TNM stage (P = 0.0056), lymph node metastasis (P = 0.0088) and poor prognosis (P = 0.0092). Importantly, TRIM59 level was higher in triple-negative breast cancer (TNBC) (P = 0.0157). Expression of TRIM59 protein was also upregulated in breast cancer cell lines compared to normal MCF-10A cell line. TRIM59 plasmid and shRNA transfection was performed in MCF-7 and SK-BR-3 cells respectively. TRIM59 overexpression promoted cell proliferation, invasion, migration, cell cycle transition, and paclitaxel resistance, whereas TRIM59 depletion showed the opposite results. Further analysis showed that TRIM59 overexpression upregulated expression of cyclinA, cyclinE, Bcl-xl, Bcl-2, p-AKT, and downregulated expression of p21, p27, p53. AKT inhibitor treatment abolished the effect of TRIM59 on Bcl-2 expression. TRIM59 overexpression also upregulated the level of p53 ubiquitination. In conclusion, TRIM59 overexpression correlates with poor prognosis and promotes malignant behavior through regulation of AKT pathway in human breast cancer.

Triple-negative and HER2 positive ductal carcinoma in situ of the breast: characteristics, behavior, and biomarker profile

We compared the characteristics, clinical behavior, and biomarker profile between HER2 positive (HER2+) and triple-negative (TN) ductal carcinoma in situ (DCIS) which are considered more aggressive than other DCIS subtypes. In addition, we explored the impact of these features on its potential of progression to invasive breast carcinomas. Cases of DCIS diagnosed at the Department of Pathology, Singapore General Hospital from 1994 to 2010 were identified. TN and HER2+ DCIS cases formed the study cohort. Immunohistochemistry (IHC) was performed for ER, PR, HER2, CK14, EGFR, and p53. Comparisons of clinicopathological features, IHC results, and clinical outcomes were performed between the two groups. We evaluated 145 HER2+ and 85 TN DCIS cases. HER2 positive DCIS had significantly higher nuclear grade (p < 0.001) and more frequent necrosis (p < 0.001) than TN DCIS. HER2 positive DCIS also harbored significantly higher rates of nuclear p53 immunoreactivity (p = 0.002) than TN DCIS. Younger patients (age < 40) with HER2+ and TN DCIS demonstrated statistically significant worse invasive DFS than older women (p < 0.001). Multivariate cox regression analysis (HR 15.08, 95% CI 12.79-81.45, p = 0.002) also confirmed these findings. In addition, younger patients (age < 40) with HER2+ DCIS experienced significantly poorer prognosis when p53 was also positive (p = 0.033). HER2+ DCIS had more aggressive pathological characteristics compared to TN DCIS; accumulation of mutant p53 could possibly be contributory. Age was an independent predictor of aggressive biological behavior of HER2+ and TN DCIS. We demonstrated that younger patients with p53 positive HER2+ DCIS had significantly adverse clinical outcome.

TRIM32 promotes proliferation and confers chemoresistance to breast cancer cells through activation of the NF-κB pathway

Dysregulation of TRIM32 has been implicated in several human cancers, however, its clinical significance and biological function in breast cancer have not been investigated. Using immunohistochemistry, we found that TRIM32 expression is upregulated in breast cancer tissues and that it correlates with advanced stage and poor prognosis. TRIM32 is also overexpressed in 4/7 breast cancer cell lines. CCK8 and colony formation assays showed that TRIM32 depletion inhibited proliferation and colony formation in the T47D cell line, while TRIM32 overexpression promoted MCF-7 cell growth and colony formation. Cell viability and Annexin V/PI staining demonstrated that TRIM32 maintained breast cancer cell survival and reduced apoptosis rate when cells were treated with cisplatin. Western blot analysis demonstrated that TRIM32 overexpression resulted in an upregulation of p-IκB, p-p65, cIAP1, and cIAP2 and a downregulation of p21 and p27 in MCF-7 cells. TRIM32 depletion in T47D cells demonstrated the opposite results, suggesting that TRIM32 may activate the NF-κB pathway. The NF-κB inhibitor BAY 11-7082 blocked the effects of TRIM32 on cisplatin resistance and cIAP1/2 protein regulation. Taken together, the present study demonstrates that TRIM32 downregulates p21/p27 and upregulates IAP family proteins to facilitate breast cancer cell growth and inhibit drug-induced apoptosis, possibly through the NF-κB signaling pathway.

Breast carcinoma in situ: An observational study of tumor subtype, treatment and outcomes

Background & Aims

To evaluate the clinical presentation, treatment and outcome of patients with breast carcinoma in situ (BCIS) with special emphasis on the role of the tumor subtype and local treatment in these patients.

Methods

Using data obtained by the Surveillance, Epidemiology, and End Results (SEER) program from 2010-2013, a retrospective, population-based cohort study was conducted to investigate tumor subtype-specific differences in various characteristics, overall survival (OS) and breast cancer-specific mortality (BCSM).

Results

In all, 6867 patients with BCIS were eligible during the 2010-2013 study period. Compared with the hormone receptor (HoR)+/HER- subgroup, patients with triple negative (TN) breast cancer were more likely to have tumors that were higher in grade and larger in size; they were also more likely to have tumors with ductal and comedo histology and were less likely to have tumors with cribriform and papillary histology (each P < 0.05). During the follow-up period, patients with TN breast cancer had an OS of 97.0% compared with 98.6 % in the HoR+/HER- subgroup (P < 0.05). Furthermore, the BCSM rate was 1.0% for the TN group compared with 0.1% for the HoR+/HER- subgroup (P < 0.05). Multivariate analysis revealed that patients with TN MBC had a poorer OS and BCSM (P <0.05). Multivariate analysis of OS with respect to the local treatment history showed that patients who received breast-conserving surgery (BCS) combined with radiotherapy (R) were more likely to have an improved OS (P < 0.05). Moreover, the results demonstrated that patients who underwent SLNB were more likely to have a lower BCSM (P < 0.05).

Conclusions

The results demonstrate that BCIS appears to alter the prognosis associated with the TN subtype. Meanwhile, BCS plus R was a preferable option and resulted in survival rates that were better than those achieved with mastectomy; thus, SLNB should be considered as an appropriate assessment of axillary staging in patients with BCIS.

Distribution of Ki-67 values within HER2 & ER/PgR expression variants of ductal breast cancers as a potential link between IHC features and breast cancer biology

BACKGROUND

Unexpected differences in Ki-67 values among HER2 & ER/PgR defined subgroups were found. This study aims to detect possible subdivisions beyond the conventional breast cancer types.

METHODS

One thousand one hundred eighty consecutive patients with invasive ductal breast carcinoma were included and distributed in 16 subgroups (four HER2 phenotypes (0+, 1+, 2+ and 3+) times four ER/PgR phenotypes). Complex distributions of Ki-67 values were tested by expectation maximization (EM) clustering.

RESULTS

Pooled Ki67 values of all patients showed the presence of three EM clusters (defined as LMA-low mitotic activity, IMA-intermediate mitotic activity and HMA-high mitotic activity) with expected mean Ki-67 values of 1.17%, 40.45% and 77.79%, respectively. Only ER-PgR- tumors significantly dispersed in three clusters (29.75% tumors in LMA, 46.95% in IMA and 23.30% in the HMA cluster), while almost no detected HMA tumors were of ER + PgR+ or ER + PgR- phenotypes. Among 799 ER + PgR+ patients distribution in clusters was HER2 dependent (p = 0.000243), due to increased number of IMA HER2 3+ tumors on the expense of LMA HER2 3+ tumors (52 IMA out of 162 HER2 3+ patients versus113 IMA out of 637 HER2 < 3+ patients). This was not found among ER + PgR- patients (p = 0.186968). Among ER-PgR- patients, HER2 overexpression also increased number of IMA tumor, but by reducing the number of HMA tumors (p < 0.000001). Here, difference between HER2 absent (0+) and HER2 3+ patients was evident (10 HMA out of 125 HER2 3+ patients versus 42 HMA out of 103 HER2 0+ patients).

CONCLUSIONS

Results suggest that distributions of breast cancers in three clusters of mitotic activity depend on different mechanisms for ER + PgR+ and ER negative tumors. Although HER2 overexpression increases number of IMA tumors in both settings, in the former it is done by reducing number of LMA tumors, while in the latter it reduces the number of HMA tumors. Mitotic activity of ER + PgR- tumors seems unrelated to the HER2 status, possibly as an indicator that ER dysfunctionality in cancers that lack PgR expression. Among ER negative tumors, the absence of HER2 (0+) might be as important as the HER2 overexpression.

Cytosolic TMEM88 promotes triple-negative breast cancer by interacting with Dvl

TMEM88, a newly discovered protein localized on the cell membrane, inhibits canonical Wnt signaling. Immunohistochemic alanalysis of 139 breast cancers pecimens(64 triple-negative cancers and 75 non-triple-negative cancers) indicated that TMEM88 is expressed at significantly higher levels in breast cancer tissues (71.22%, 99/139) than in normal breast tissues (11.4%, 4/35; p < 0.001). The cytosolic and nuclear expression rates of TMEM88 were 57.81% and 9.37% in triple-negative and 52% and 33.33% (p = 0.5 and p = 0.001) in the non-triple-negative breast cancer tissues, respectively. Western blot analyses indicated that TMEM88 promoted Snail expression and inhibited Zo-1 and Occludin expression by interacting with dishevelled (Dvl) proteins, thereby stimulating invasion and metastasis in breast cancer. While cytosolic TMEM88 did not affect canonical Wnt signaling, cytosolic localization of this protein was positively correlated with both advanced TNM stage (p = 0.038 and p < 0.001) and lymph node metastasis (p = 0.01 and p = 0.002) in all and triple-negative specimens, respectively, and stimulated cell invasion by interacting with Dvls. Meanwhile, nuclear localization of TMEM88 was negatively correlated with lymph node metastasis (p = 0.046). Lastly, the increased prevalence of TMEM88 nuclear localization observed in non-triple-negative, compared to triple-negative tissues, suggests that the biological roles of TMEM88 differ depending on the subcellular localization.

Extent of ductal carcinoma in situ according to breast cancer subtypes: a population-based cohort study

Ductal carcinoma in situ (DCIS) is a precursor of invasive breast carcinoma (IBC). The DCIS component is often more extensive than the invasive component, which affects local control. The aim of our study was to analyze features of DCIS within different IBC subtypes, which may contribute to the optimization of personalized approaches for patients with IBC. Patients with IBC reported according to the synoptic reporting module in the Netherlands between 2009 and 2015 were included. Data extraction included characteristics of the invasive component and, if present, several features of the DCIS component. Resection margin status analyses were restricted to patients undergoing breast-conserving surgery (BCS). Differences between subtypes were tested by a Chi-square test, spearman’s Rho test or a one-way ANOVA test. Overall, 36.937 cases of IBC were included. About half of the IBCs (n = 16.014; 43.4 %) were associated with DCIS. Her2+ IBC (irrespective of ER status) was associated with a higher prevalence of adjacent DCIS, a larger extent of DCIS and a higher rate of irradicality of the DCIS component as compared to ER+/Her2− and triple-negative subtypes (P < 0.0001 for all variables). The prevalence of DCIS in triple-negative IBC on the other hand was lowest. In this large population-based cohort study, we showed significant differences between the prevalence and extent of DCIS according to IBC subtypes, which is also reflected in the resection margin status in patients treated with BCS. Our data provide important information regarding the optimization of local therapy according to IBC subtypes.

Clinicopathologic characteristics and molecular subtypes of microinvasive carcinoma of the breast

Patients with microinvasive carcinoma often have favorable prognosis, but it remains unclear whether this special type of breast cancer represents a distinct morphological entity with its own biological features and clinical behavior distinct from those of ductal carcinoma in situ (DCIS). The study is a retrospective analysis of a large patient cohort from a single institution. One hundred and thirty one microinvasive carcinoma and 451 DCIS cases were collected. ER, PR, HER2, and Ki67 were examined by immunohistochemistry in pathological sections. We assessed the clinicopathologic characteristics, molecular features, and survival status of microinvasive carcinoma and compared to those of DCIS. Microinvasive carcinoma differed from DCIS with respect to tumor size, lymph node status, and initial presentation (P < 0.05). There was a significant difference in nuclear grade among microinvasive carcinoma of different molecular subtype (P < 0.05). The clinicalpathologic features and outcomes of patients with microinvasive carcinoma were similar to those with DCIS. The 5-year OS rate for microinvasive carcinoma and DCIS patients was 99.0 and 99.2%, respectively. A combination of pathologic, clinical, and molecular factors may ultimately reveal more powerful and robust measures for disease classification than any one modality alone. Microinvasive carcinoma does not significantly predict for worse DFS or OS in comparison with patients with DCIS.

Overexpression of SMARCA5 correlates with cell proliferation and migration in breast cancer

SMARCA5 partners with RSF-1 to compose the RSF complex, which belongs to the ISWI family of chromatin remodelers. Recent studies referred that SMARCA5 was overexpressed in some malignant tumors. However, expression pattern and biological roles of SMARCA5 in breast cancer have not been examined. In the present study, we found that SMARCA5 was overexpressed in breast cancer specimens by immunohistochemistry. Significant association was observed between SMARCA5 overexpression and TNM stage (p = 0.0199), tumor size (p = 0.0066), high proliferation index (p = 0.0366), and poor overall survival (p = 0.0141). SMARCA5 overexpression also correlated with Rsf-1 expression levels (p = 0.0120). Furthermore, colony formation assay and Matrigel invasion assay showed that knockdown of SMARCA5 expression in MDA-MB-231 and MDA-MB-435s cell lines with high endogenous expression decreased cell proliferation and cell invasion. Flow cytometry showed knockdown of SMARCA5-arrested cell cycle. Further analysis of cell cycle and invasion-related molecules showed that SMARCA5 downregulated cyclin A, MMP2 expression and upregulated p21 expression. In conclusion, our study demonstrated that SMARCA5 was overexpressed in human breast cancers and correlated with poor prognosis. SMARCA5 contributes to breast cancer cell proliferation and invasion.

DNA repair and redox activities and inhibitors of apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1): a comparative analysis and their scope and limitations toward anticancer drug development

The apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme involved in DNA repair and activation of transcription factors through its redox function. The evolutionarily conserved C- and N-termini are involved in these functions independently. It is also reported that the activity of APE1/Ref-1 abruptly increases several-fold in various human cancers. The control over the outcomes of these two functions is emerging as a new strategy to combine enhanced DNA damage and chemotherapy in order to tackle the major hurdle of increased cancer cell growth and proliferation. Studies have targeted these two domains individually for the design and development of inhibitors for APE1/Ref-1. Here, we have made, for the first time, an attempt at a comparative analysis of APE1/Ref-1 inhibitors that target both DNA repair and redox activities simultaneously. We further discuss their scope and limitations with respect to the development of potential anticancer agents.

A model of immunohistochemical differences between invasive breast cancers and DCIS lesions tested on a consecutive case series of 1248 patients

BACKGROUND

A previous theoretic model (Tumour Biol 2013;34:1-7.) that breast tumor types differ in the relative rate of tissue invasion was elaborated and developed on a consecutive case series.

METHOD

Histologic data of 68 ductal breast cancer in situ (DCIS) and 1180 invasive ductal cancer (IDC) patients were collected and analyzed.

RESULTS

ER+PgR- phenotype was more common in Luminal B2 than among the pooled Luminal A&B1 (p = 0.0002), and more frequent in Luminal B1 than in Luminal A (p = 0.0167). The same phenotype was associated with the age older than 54 years in Luminal B1 and in B2 patients. HER2 type cancers were more frequent in older patients (p = 0.0038).Tumor progression from DCIS to IDC was found 39% faster than the average in Luminal B1 tumors, supporting the clinical importance of this tumor type. A rare combination of low Ki-67 in HER2 type cancers (only 14% of HER2 type cancers) showed very slow transition to IDC (occurring at only 53.55% of average progression rate), while triple-negative cancers progressed faster than the average, despite Ki-67 value (104.63% for low and 114.27% for high Ki-67 tumors).In three tumor types with positive steroid receptors the ER+PgR- phenotype showed slower IDC transition than the ER+PgR+ phenotype of the same tumor type (difference in progression rate was 38% for Luminal A, 46% for Luminal B1 and 67% for Luminal B2 with Ki67 > 14%).Triple-negative tumors in younger patients exceeded the expected average progression rate by 24%, while in HER2 type tumors, the rate of tissue invasion was in younger patients 20% lower than the expected value.

CONCLUSIONS

The relative rate of tissue invasion differed substantialy among our patients. Differences depended on tumor types, steroid expression phenotypes and age. The dysfunctional ERs in the ER+PgR- phenotype showed slower rates of tissue invasion, suggesting that ligand binding to functional breast tumor ERs, beside promoting the PgR expression, possibly also promotes tumor transition to the invasive phase.In triple-negative tumors, an age dependent premenopausal mechanism possibly acted as an accelerator of tissue invasion, while faster tissue invasion by HER2-overexpressed tumors in older patients possibly depended on an unidentified mechanism that takes more time to be acquired, so it was less present in premenopausal patients.

Diversin is overexpressed in breast cancer and accelerates cell proliferation and invasion

Diversin was recently reported to play roles in Wnt and JNK pathways. However, the expression pattern and biological roles of diversin in human breast cancer have not been reported. In the present study, we found that diversin was overexpressed in breast cancer specimens by immunohistochemistry and western blot. Significant association was observed between diversin overexpression and TNM stage (p = 0.0036), nodal metastasis (p = 0.0033), negative estrogen receptor expression (p = 0.0012) and triple-negative status (p = 0.0017). Furthermore, colony formation assay and matrigel invasion assay showed that knockdown of diversin expression in MDA-MB-231 cell line with high endogenous expression decreased cell proliferation and cell invasion. Transfection of diversin plasmid in MCF-7 cell line increased cell proliferation and invasion. Further analysis showed that diversin depletion downregulated JNK phosphorylation while its overexpression upregulated JNK phosphorylation. In conclusion, our study demonstrated that diversin was overexpressed in human breast cancers. Diversin could contribute to breast cancer cell proliferation and invasion.

Model of tumor-associated epigenetic changes of HER2, ER, and PgR expression in invasive breast cancer phenotypes

This theoretic paper is an attempt to apply the epigenetic progenitor model of human cancer origin, proposed by Feinberg et al. (Nat Rev Genet 7:21-33, 2006), to the reported phenotype features of invasive breast cancer. The model is based on the idea that expression of estrogen receptors (ER), progesterone receptors (PgR), and HER2 molecules in breast tumors is either remnants of the tissue stem cell from which the tumor has developed or a newly acquired tumor-associated epigenetic feature. HER2 overexpression is considered as an example of the tumor-associated epigenetic changes. The model makes a simple distinction regarding the possible types of ER and PgR expression: the "functional" steroid hormone receptors are inherited from pretumoral tissue stem cells, while the "dysfunctional" steroid hormone receptors are acquired during tumorigenesis from initially ER-PgR-negative cells. In the former, estrogen binding increases the PgR expression while progesterone binding decreases the expression of ER and PgR. Since the estrogen-dependent PgR expression works only in cells with functional ERs, the expected share of tumors with functional ER and PgR receptors is in the model calculated as the squared probability of expressing the PgRs. Reported data from various trials are pooled together to find out phenotype shares (ER+PgR+ makes 62.03 %, ER+PgR- 16.43 %, ER-PgR+ 3.06, and ER-PgR- 18.48 %). By applying the model on these shares, the proposed share of tumors with the functional ER+PgR+ phenotype was 38.48 %, while the share of tumors with the dysfunctional ER+PgR+ was 23.55 %. The presented model suggests that both luminal A and luminal B tumor types are heterogeneous regarding the steroid receptor expression. Some tumors have functional and some have dysfunctional steroid receptors. If these predicted subgroups exist, their detection in the clinical practice might substantially improve treatment options, particularly in the premenopausal setting.

Ductal carcinoma in situ: how should we treat it?

SUMMARY The observed incidence of ductal carcinoma in situ (DCIS) has increased because of the increasing use of sensitive imaging modalities. While the clinical course of DCIS is quite variable, it is considered a precursor lesion to invasive breast cancer. The current focus of DCIS treatment is on the prevention of progression to invasive disease. However, at present, validated diagnostic tests to predict progression accurately are lacking. Additionally, important clinical questions arise during DCIS management. For example, optimal margins of excision or axillary lymph node sampling have not been addressed in randomized clinical trials. May whole-breast radiation after lumpectomy be omitted in selected patients? What is the role of adjuvant tamoxifen if it does not impact overall survival rates? This review aims to describe the natural history of DCIS and highlights the current therapeutic options and challenges in patient management.

Immunohistochemical profile of high-grade ductal carcinoma in situ of the breast

OBJECTIVE

To determine the frequency of the immunohistochemical profiles of a series of high-grade ductal carcinoma in situ of the breast.

METHODS

One hundred and twenty-one cases of high-grade ductal carcinoma in situ, pure or associated with invasive mammary carcinoma, were identified from 2003 to 2008 and examined with immunohistochemistry for estrogen receptor, human epidermal growth factor receptor 2, cytokeratin 5, and epidermal growth factor receptor. The tumors were placed into five subgroups: luminal A, luminal B, HER2, basal-like, and "not classified".

RESULTS

The frequencies of the immunophenotypes of pure ductal carcinoma in situ were the following: luminal A (24/42 cases; 57.1%), luminal B (05/42 cases; 11.9%), HER2 (07/42 cases; 16.7%), basal-like phenotype (00/42 cases; 0%), and "not classified" (06/42 cases; 14.3%). The immunophenotypes of ductal carcinoma in situ associated with invasive carcinoma were the following: luminal A (46/79 cases; 58.2%), luminal B (10/79 cases; 12.7%), HER2 (06/79 cases; 7.6%), basal-like (06/79 cases; 7.6%), and "not classified" (11/79 cases; 13.9%). There was no significant difference in the immunophenotype frequencies between pure ductal carcinoma in situ and ductal carcinoma in situ associated with invasive carcinoma (p>0.05). High agreement was observed in immunophenotypes between both components (kappa=0.867).

CONCLUSION

The most common immunophenotype of pure ductal carcinoma in situ was luminal A, followed by HER2. The basal-like phenotype was observed only in ductal carcinoma in situ associated with invasive carcinoma, which had a similar phenotype.