The molecular mechanisms underlying reduced E-cadherin expression in invasive ductal carcinoma of the breast: high throughput analysis of large cohorts

E-cadherin is a tumor suppressor gene in invasive lobular breast cancer. However, a proportion of high-grade ductal carcinoma shows reduced/loss of E-cadherin. In this study, we assessed the underlying mechanisms and molecular implications of E-cadherin loss in invasive ductal carcinoma. This study used large, well-characterized cohorts of early-stage breast cancer-evaluated E-cadherin expression via various platforms including immunohistochemistry, microarray analysis using Illumina HT-12 v3, copy number analysis using Affymetrix SNP 6.0 arrays, and next-generation sequencing for differential gene expression. Our results showed 27% of high-grade invasive ductal carcinoma showed reduced/loss of E-cadherin membranous expression. CDH1 copy number loss was in 21% of invasive ductal carcinoma, which also showed low CDH1 mRNA expression (p = 0.003). CDH1 copy number was associated with copy number loss of TP53, ATM, BRCA1, and BRCA2 (p < 0.001). Seventy-nine percent of invasive ductal carcinoma with reduced CDH1 mRNA expression showed elevated expression of E-cadherin transcription suppressors TWIST2, ZEB2, NFKB1, LLGL2, CTNNB1 (p < 0.01). Reduced/loss E-cadherin expression was associated with differential expression of 2143 genes including those regulating Wnt (FZD2, GNG5, HLTF, WNT2, and CER1) and PIK3-AKT (FGFR2, GNF5, GNGT1, IFNA17, and IGF1) signaling pathways. Interestingly, key genes differentially expressed between invasive lobular carcinoma and invasive ductal tumors did not show association with E-cadherin loss in invasive ductal carcinoma. We conclude that E-cadherin loss in invasive ductal carcinoma is likely a consequence of genomic instability occurring during carcinogenesis. Potential novel regulators controlling E-cadherin expression in invasive ductal carcinoma warrant further investigation

A centrosome clustering protein, KIFC1, predicts aggressive disease course in serous ovarian adenocarcinomas

Background Amplified centrosomes are widely recognized as a hallmark of cancer. Although supernumerary centrosomes would be expected to compromise cell viability by yielding multipolar spindles that results in death-inducing aneuploidy, cancer cells suppress multipolarity by clustering their extra centrosomes. Thus, cancer cells, with the aid of clustering mechanisms, maintain pseudobipolar spindle phenotypes that are associated with low-grade aneuploidy, an edge to their survival. KIFC1, a nonessential minus end-directed motor of the kinesin-14 family, is a centrosome clustering molecule, essential for viability of extra centrosome-bearing cancer cells. Given that ovarian cancers robustly display amplified centrosomes, we examined the overexpression of KIFC1 in human ovarian tumors. Results We found that in clinical epithelial ovarian cancer (EOC) samples, an expression level of KIFC1 was significantly higher when compared to normal tissues. KIFC1 expression also increased with tumor grade. Our In silico analyses showed that higher KIFC1 expression was associated with poor overall survival (OS) in serous ovarian adenocarcinoma (SOC) patients suggesting that an aggressive disease course in ovarian adenocarcinoma patients can be attributed to high KIFC1 levels. Also, gene expression levels of KIFC1 in high-grade serous ovarian carcinoma (HGSOC) highly correlated with expression of genes driving centrosome amplification (CA), as examined in publically-available databases. The pathway analysis results indicated that the genes overexpressed in KIFC1 high group were associated with processes like regulation of the cell cycle and cell proliferation. In addition, when we performed gene set enrichment analysis (GSEA) for identifying the gene ontologies associated to KIFC1 high group, we found that the first 100 genes enriched in KIFC1 high group were from centrosome components, mitotic cell cycle, and microtubule-based processes. Results from in vitro experiments on well-established in vitro models of HGSOC (OVSAHO, KURAMOCHI), OVCAR3 and SKOV3) revealed that they display robust centrosome amplification and expression levels of KIFC1 was directly associated (inversely correlated) to the status of multipolar mitosis. This association of KIFC1 and centrosome amplification with HGSOC might be able to explain the increased aggressiveness in this disease. Conclusion These findings compellingly underscore that KIFC1 can be a biomarker that predicts an aggressive disease course in ovarian adenocarcinomas

Amplified centrosomes and mitotic index display poor concordance between patient tumors and cultured cancer cells

Centrosome aberrations (CA) and abnormal mitoses are considered beacons of malignancy. Cancer cell doubling times in patient tumors are longer than in cultures, but differences in CA between tumors and cultured cells are uncharacterized. We compare mitoses and CA in patient tumors, xenografts, and tumor cell lines. We find that mitoses are rare in patient tumors compared with xenografts and cell lines. Contrastingly, CA is more extensive in patient tumors and xenografts (~35–50% cells) than cell lines (~5–15%), although CA declines in patient-derived tumor cells over time. Intratumoral hypoxia may explain elevated CA in vivo because exposure of cultured cells to hypoxia or mimicking hypoxia pharmacologically or genetically increases CA, and HIF-1α and hypoxic gene signature expression correlate with CA and centrosomal gene signature expression in breast tumors. These results highlight the importance of utilizing low-passage-number patient-derived cell lines in studying CA to more faithfully recapitulate in vivo cellular phenotypes

Prognostic significance of tumor-infiltrating lymphocytes in ductal carcinoma in situ of the breast

Tumor-infiltrating lymphocytes (TILs) provide prognostic value in invasive breast cancer and guidelines for their assessment have been published. This study aims to evaluate: (a) methods of TILs assessment, and (b) their prognostic significance in breast ductal carcinoma in situ (DCIS). Hematoxylin and eosin sections from two clinically annotated DCIS cohorts; a training set (n = 150 pure DCIS) and a validation set (n = 666 comprising 534 pure DCIS and 132 cases wherein DCIS and invasive breast carcinoma were co-existent) were assessed. Seven different scoring methods were applied to the training set to identify the most optimal reproducible method associated with strongest prognostic value. Among different methods, TILs touching ducts' basement membrane or away from it by one lymphocyte cell thickness provided the strongest significant association with outcome and highest concordance rate [inter-cluster correlation coefficient = 0.95]. Assessment of periductal TILs at increasing distances from DCIS (0.2 , 0.5 , and 1 mm) as well as percent of stromal TILs were practically challenging and showed lower concordance rates than touching TILs. TILs hotspots and lymphoid follicles did not show prognostic significance. Within the pure DCIS validation set, dense TILs were associated with younger age, symptomatic presentation, larger size, higher nuclear grade, comedo necrosis and estrogen receptor negativity as well as shorter recurrence-free interval (p = 0.002). In multivariate survival analysis, dense TILs were independent predictor of shorter recurrence-free interval (p = 0.002) in patients treated with breast conservation. DCIS associated with invasive carcinoma showed denser TILs than pure DCIS (p = 9.0 × 10-13). Dense TILs is an independent prognostic variable in DCIS. Touching TILs provides a reproducible method for their assessment that can potentially be used to guide management

Novel immunohistochemistry-based signatures to predict metastatic site of triple-negative breast cancers

Background: Although distant metastasis (DM) in breast cancer (BC) is the most lethal form of recurrence and the most commonunderlying cause of cancer related deaths, the outcome following the development of DM is related to the site of metastasis.Triple negative BC (TNBC) is an aggressive form of BC characterised by early recurrences and high mortality. Athough multiplevariables can be used to predict the risk of metastasis, few markers can predict the specific site of metastasis. This study aimed atidentifying a biomarker signature to predict particular sites of DM in TNBC.Methods: A clinically annotated series of 322 TNBC were immunohistochemically stained with 133 biomarkers relevant to BC, todevelop multibiomarker models for predicting metastasis to the bone, liver, lung and brain. Patients who experienced metastasisto each site were compared with those who did not, by gradually filtering the biomarker set via a two-tailed t-test and Coxunivariate analyses. Biomarker combinations were finally ranked based on statistical significance, and evaluated in multivariableanalyses.Results: Our final models were able to stratify TNBC patients into high risk groups that showed over 5, 6, 7 and 8 times higher riskof developing metastasis to the bone, liver, lung and brain, respectively, than low-risk subgroups. These models for predictingsite-specific metastasis retained significance following adjustment for tumour size, patient age and chemotherapy status.Conclusions: Our novel IHC-based biomarkers signatures, when assessed in primary TNBC tumours, enable prediction of specificsites of metastasis, and potentially unravel biomarkers previously unknown in site tropism

Distinctions in Breast Tumor Recurrence Patterns Post-Therapy among Racially Distinct Populations

<div><p>Background</p><p>Clinical studies have revealed a higher risk of breast tumor recurrence in African-American (AA) patients compared to European-American (EA) patients, contributing to the alarming inequality in clinical outcomes among the ethnic groups. However, distinctions in recurrence patterns upon receiving hormone, radiation, and/or chemotherapy between the races remain poorly characterized.</p><p>Methods</p><p>We compared patterns and rates (per 1000 cancer patients per 1 year) of recurrence following each form of treatment between AA (n = 1850) and EA breast cancer patients (n = 7931) from a cohort of patients (n = 10504) treated between 2005–2015 at Northside Hospital in Atlanta, GA.</p><p>Results</p><p>Among patients who received any combination of adjuvant therapy, AA displayed higher overall rates of recurrence than EA (p = 0.015; HR: 1.699; CI: 1.108–2.606). Furthermore, recurrence rates were higher in AA than EA among stage I (p = 0.031; HR: 1.736; CI: 1.052–2.864) and T1 classified patients (p = 0.003; HR: 2.009; CI: 1.263–3.197). Interestingly, among patients who received neoadjuvant chemotherapy, AA displayed higher rates of local recurrence than EA (p = 0.024; HR: 7.134; CI: 1.295–39.313).</p><p>Conclusion</p><p>Our analysis revealed higher incidence rates of recurrence in AA compared to EA among patients that received any combination of adjuvant therapy. Moreover, our data demonstrates an increased risk of tumor recurrence in AA than EA among patients diagnosed with minimally invasive disease. This is the first clinical study to suggest that neoadjuvant chemotherapy improves breast cancer recurrence rates and patterns in AA.</p></div

Broad-spectrum recurrence patterns among racially distinct populations.

<p>Broad-spectrum recurrence patterns among racially distinct populations.</p