The Clinical and Biological Significance of Estrogen Receptor-Low Positive Breast Cancer.

Estrogen receptor (ER) status in breast cancer (BC) is determined using immunohistochemistry (IHC) with nuclear expression in ≥1% of cells defined as ER-positive. BC with 1%-9% expression (ER-low-positive), is a clinically and biologically unique subgroup. In this study, we hypothesized that ER-low-positive BC represents a heterogeneous group with a mixture of ER-positive and ER-negative tumor, which may explain their divergent clinical behavior. A large BC cohort (n = 8171) was investigated and categorized into 3 groups: ER-low-positive (1%-9%), ER-positive (≥10%), and ER-negative (<1%) where clinicopathological and outcome characteristics were compared. A subset of ER-low-positive cases was further evaluated using IHC, RNAscope, and RT-qPCR. PAM50 subtyping and ESR1 mRNA expression levels were assessed in ER-low-positive cases within The Cancer Genome Atlas data set. The reliability of image analysis software in assessment of ER expression in the ER-low-positive category was also assessed. ER-low-positive tumors constituted <2% of BC cases examined and showed significant clinicopathological similarity to ER-negative tumors. Most of these tumors were nonluminal types showing low ESR1 mRNA expression. Further validation of ER status revealed that 45% of these tumors were ER-negative with repeated IHC staining and confirmed by RNAscope and RT-qPCR. ER-low-positive tumors diagnosed on needle core biopsy were enriched with false-positive ER staining. BCs with 10% ER behaved similar to ER-positive, rather than ER-negative or low-positive BCs. Moderate concordance was found in assessment of ER-low-positive tumors, and this was not improved by image analysis. Routinely diagnosed ER-low-positive BC includes a proportion of ER-negative cases. We recommend repeat testing of BC showing 1%-9% ER expression and using a cutoff ≥10% expression to define ER positivity to help better inform treatment decisions.

Current research status of anti-cancer peptides: Mechanism of action, production, and clinical applications.

The escalating rate of cancer cases, together with treatment deficiencies and long-term side effects of currently used cancer drugs, has made this disease a global burden of the 21st century. The number of breast and lung cancer patients has sharply increased worldwide in the last few years. Presently, surgical treatment, radiotherapy, chemotherapy, and immunotherapy strategies are used to cure cancer, which cause severe side effects, toxicities, and drug resistance. In recent years, anti-cancer peptides have become an eminent therapeutic strategy for cancer treatment due to their high specificity and fewer side effects and toxicity. This review presents an updated overview of different anti-cancer peptides, their mechanisms of action and current production strategies employed for their manufacture. In addition, approved and under clinical trials anti-cancer peptides and their applications have been discussed. This review provides updated information on therapeutic anti-cancer peptides that hold great promise for cancer treatment in the near future.

Increased inflammatory cytokines and oxidative stress enhanced antibody production in breast and prostate cancer patients with COVID-19 related depression.

Cancer management is highly dependent on the immune status of the patient. During the COVID-19 pandemic, a large number of people suffered from anxiety and depression, especially cancer patients. The effect of depression on breast cancer (BC) and prostate cancer (PC) patients, during the pandemic has been analyzed in this study. Levels of proinflammatory cytokines (IFN-γ, TNF-α, and IL-6) and oxidative stress markers malondialdehyde (MDA) and carbonyl content (CC) were estimated in patients' serum samples. Serum antibodies against in vitro hydroxyl radical (•OH) modified pDNA (•OH-pDNA-Abs) were estimated using direct binding and inhibition ELISA. Cancer patients showed increased levels of proinflammatory cytokines (IFN-γ, TNF-α, and IL-6) and oxidative stress markers (MDA and CC levels), which were further significantly enhanced in cancer patients with depression compared to normal healthy (NH) individuals. Increased levels of •OH-pDNA-Abs were detected in breast cancer (0.506 ± 0.063) and prostate cancer (0.441 ± 0.066) patients compared to NH subjects. Serum antibodies were found to be significantly elevated in BC patients with depression (BCD) (0.698 ± 0.078) and prostate cancer patients with depression (PCD) (0.636 ± 0.058). Inhibition ELISA also exhibited significantly high percent inhibition in BCD (68.8% ± 7.8%) and PCD (62.9% ± 8.3%) subjects compared to BC (48.9% ± 8.1%), and PC (43.4% ± 7.5%) subjects. Cancer is characterized by enhanced oxidative stress and increased inflammation, which may be exaggerated with COVID-19 related depression. High oxidative stress and compromised antioxidant homeostasis exerts alterations in DNA, leading to formation of neo-antigens, subsequently leading to the generation of antibodies. COVID-19 pandemic related depression needs to be addressed globally for improved cancer patient care and cancer disease management.

Sodium alginate encapsulated iron oxide decorated with thymoquinone nanocomposite induces apoptosis in human breast cancer cells via PI3K-Akt-mTOR pathway.

The present study investigated the cytotoxicity and proapoptotic properties of iron oxide-sodium-alginate-thymoquinone nanocomposites against breast cancer MDA-MB-231 cells in vitro and in silico. This study used chemical synthesis to formulate the nanocomposite. Electron microscopies such as scanning (SEM) and transmission (TEM), Fourier transform infrared (FT-IR), Ultraviolet-Visible, Photoluminescence spectroscopy, selected area (electron) diffraction (SAED), energy dispersive X-ray analysis (EDX), and X-ray diffraction studies (XRD) were used to characterize the synthesized ISAT-NCs and the average size of them was found to be 55 nm. To evaluate the cytotoxic, antiproliferative, and apoptotic potentials of ISAT-NCs on MDA-MB-231 cells, MTT assays, FACS-based cell cycle studies, annexin-V-PI staining, ELISA, and qRT-PCR were used. PI3K-Akt-mTOR receptors and thymoquinone were predicted using in-silico docking studies. Cell proliferation is reduced in MDA-MB-231 cells due to ISAT-NC cytotoxicity. As a result of FACS analysis, ISAT-NCs had nuclear damage, ROS production, and elevated annexin-V levels, which resulted in cell cycle arrest in the S phase. The ISAT-NCs in MDA-MB-231 cells were found to downregulate PI3K-Akt-mTOR regulatory pathways in the presence of inhibitors of PI3K-Akt-mTOR, showing that these regulatory pathways are involved in apoptotic cell death. We also predicted the molecular interaction between thymoquinone and PI3K-Akt-mTOR receptor proteins using in-silico docking studies which also support PI3K-Akt-mTOR signaling inhibition by ISAT-NCs in MDA-MB-231 cells. As a result of this study, we can conclude that ISAT-NCs inhibit the PI3K-Akt-mTOR pathway in breast cancer cell lines, causing apoptotic cell death.

Effects of Albumin-Chlorogenic Acid Nanoparticles on Apoptosis and PI3K/Akt/mTOR Pathway Inhibitory Activity in MDA-MB-435s Cells.

In this study, we synthesized, characterized, and explored the anti-microbial and anti-cancer effects of albumin-chlorogenic acid nanoparticles (NPs). Characterization studies with a UV-vis spectrophotometer, FTIR, PL spectrum, TEM, FESEM, XRD, and DLA analysis showed patterns confirming the physio-chemical nature of biogenic nanocomposites. Further, anti-microbial studies using bacterial strains Staphylococcus aureus, Streptococcus pneumonia, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Vibrio cholera, and fungal strain Candida albicans showed significant (p < 0.05) anti-bacterial and anti-fungal activities. Next, we used MDA-MB-435s, a human cell line, to evaluate the anti-cancer effects of albumin-chlorogenic acid NPs. Cytotoxic studies revealed its IC50 concentration at 24 µg/mL after a 24 h treatment of MDA-MB-435s cells. We chose this IC50 dose to analyze albumin-chlorogenic acid NPs anti-cancer effects in vitro. MDA-MB-435s cells exposed to our NPs were studied via AO/EtBr staining, cell cycle analyses via PI staining, the status of whole genomic damage via comet assay, levels of apoptotic cells via annexin V/PI staining, ROS generation via DCFH-DA staining, an assay of antioxidant enzymes catalase, superoxide dismutase, and antioxidant GSH, via ELISA analyses of apoptotic markers caspase-3, 8, 9, Bax, Bcl-2, CytC, and p53, PI3/AKT/mTOR pathway. Our results collectively showed albumin-chlorogenic acid NPs induced apoptosis via p53-dependent and PI3/AKT/mTOR inhibition in MDA-MB-435s cells. Our results denote albumin-chlorogenic acid NPs can be used as an effective candidate for anti-microbial and anti-cancer applications; however, further in vivo confirmatory studies are warranted.

Therapeutic Potential of Albumin Nanoparticles Encapsulated Visnagin in MDA-MB-468 Triple-Negative Breast Cancer Cells.

Breast cancer is among the most recurrent malignancies, and its prevalence is rising. With only a few treatment options available, there is an immediate need to search for better alternatives. In this regard, nanotechnology has been applied to develop potential chemotherapeutic techniques, particularly for cancer therapy. Specifically, albumin-based nanoparticles are a developing platform for the administration of diverse chemotherapy drugs owing to their biocompatibility and non-toxicity. Visnagin, a naturally derived furanochromone, treats cancers, epilepsy, angina, coughs, and inflammatory illnesses. In the current study, the synthesis and characterization of albumin visnagin (AV) nanoparticles (NPs) using a variety of techniques such as transmission electron microscopy, UV-visible, Fourier transform infrared, energy dispersive X-ray composition analysis, field emission scanning electron microscopy, photoluminescence, X-Ray diffraction, and dynamic light scattering analyses have been carried out. The MTT test, dual AO/EB, DCFH-DA, Annexin-V-FITC/PI, Propidium iodide staining techniques as well as analysis of apoptotic proteins, antioxidant enzymes, and PI3K/Akt/mTOR signaling analysis was performed to examine the NPs' efficacy to suppress MDA-MB-468 cell lines. The NPs decreased cell viability increased the amount of ROS in the cells, disrupted membrane integrity, decreased the level of antioxidant enzymes, induced cell cycle arrest, and activated the PI3K/Akt/mTOR signaling cascade, ultimately leading to cell death. Thus, AV NPs possesses huge potential to be employed as a strong anticancer therapy alternative.

Synthesis, Characterization, and Antimicrobial and Antiproliferative Effects of CuO-TiO2-Chitosan-Escin Nanocomposites on Human Leukemic MOLT4 Cells.

Nanocomposites comprised of CuO-TiO2-chitosan-escin, which has adjustable physicochemical properties, provide a solution for therapeutic selectivity in cancer treatment. By controlling the intrinsic signaling primarily through the mitochondrial signaling pathway, we desired nanocomposites with enhanced anticancer activity by containing CuO-TiO2-chitosan-escin. The metal oxides CuO and TiO2, the natural polymer chitosan, and a phytochemical compound escin were combined to form CuO-TiO2-chitosan-escin nanocomposites. The synthesized nanocomposites were confirmed and characterized using FTIR spectroscopy, TEM, and UV-Vis absorption spectroscopy. A human leukemia cell line (MOLT-4) was used to assess the efficacy and selectivity of nanocomposites. Based on a cytotoxicity study, CuO-TiO2-chitosan-escin nanocomposites had inhibition concentrations (IC50) of 13.68, 8.9, and 7.14 µg/mL against human T lymphoblast cells after 24, 48, and 72 h of incubation, respectively. Compared with untreated MOLT-4 cells, CuO-TiO2-chitosan-escin nanocomposite-treated cells significantly increased (p < 0.05) caspase-3, -8, and -9 and decreased the levels of antioxidant enzymes GR, SOD, and GSH. Furthermore, MDA for lipid peroxidase and ROS levels significantly increased (p < 0.05) in the treated cells than in the untreated cells. Remarkably, CuO-TiO2-chitosan-escin nanocomposite-mediated control of cell cycles were mainly achieved through the activation of caspase-3, -8, and -9.

Oestrogen-regulated protein SLC39A6: a biomarker of good prognosis in luminal breast cancer.

PURPOSE: The outcome of the luminal oestrogen receptor-positive (ER +) subtype of breast cancer (BC) is highly variable and patient stratification needs to be refined. We assessed the prognostic significance of oestrogen-regulated solute carrier family 39 member 6 (SLC39A6) in BC, with emphasis on ER + tumours. MATERIALS AND METHODS: SLC39A6 mRNA expression and copy number alterations were assessed using the METABRIC cohort (n = 1980). SLC39A6 protein expression was evaluated in a large (n = 670) and annotated series of early-stage (I-III) operable BC using tissue microarrays and immunohistochemistry. The associations between SLC39A6 expression and clinicopathological parameters, patient outcomes and other ER-related markers were evaluated using Chi-square tests and Kaplan-Meier curves. RESULTS: High SLC39A6 mRNA and protein expression was associated with features characteristic of less aggressive tumours in the entire BC cohort and ER + subgroup. SLC39A6 protein expression was detected in the cytoplasm and nuclei of the tumour cells. High SLC39A6 nuclear expression and mRNA levels were positively associated with ER + tumours and expression of ER-related markers, including the progesterone receptor, forkhead box protein A1 and GATA binding protein 3. In the ER + luminal BC, high SLC39A6 expression was independently associated with longer BC-specific survival (BCSS) (P = 0.015, HR 0.678, 95% CI 0.472‒0.972) even in those who did not receive endocrine therapy (P = 0.001, HR 0.701, 95% CI 0.463‒1.062). CONCLUSION: SLC39A6 may be prognostic for a better outcome in ER + luminal BC. Further functional studies to investigate the role of SLC39A6 in ER + luminal BC are warranted.

Nucleolar protein 10 (NOP10) predicts poor prognosis in invasive breast cancer.

PURPOSE: Nucleolar protein 10 (NOP10) is required for ribosome biogenesis and telomere maintenance and plays a key role in carcinogenesis. This study aims to evaluate the clinical and prognostic significance of NOP10 in breast cancer (BC). METHODS: NOP10 expression was assessed at mRNA level employing the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) (n = 1980) and Cancer Genome Atlas (TCGA) BC cohorts (n = 854). Protein expression was evaluated on tissue microarray of a large BC cohort (n = 1081) using immunohistochemistry. The correlation between NOP10 expression, clinicopathological parameters and patient outcome was assessed. RESULTS: NOP10 expression was detected in the nucleus and nucleolus of the tumour cells. At the transcriptomic and proteomic levels, NOP10 was significantly associated with aggressive BC features including high tumour grade, high nucleolar score and poor Nottingham Prognostic Index. High NOP10 protein expression was an independent predictor of poor outcome in the whole cohort and in triple-negative BC (TNBC) class (p = 0.002 & p = 0.014, respectively). In chemotherapy- treated patients, high NOP10 protein expression was significantly associated with shorter survival (p = 0.03) and was predictive of higher risk of death (p = 0.028) and development of distant metastasis (p = 0.02) independent of tumour size, nodal stage and tumour grade. CONCLUSION: High NOP10 expression is a poor prognostic biomarker in BC and its expression can help in predicting chemotherapy resistance. Functional assessments are necessary to decipher the underlying mechanisms and to reveal its potential therapeutic values in various BC subtypes especially in the aggressive TNBC class.

The prognostic significance of BMI1 expression in invasive breast cancer is dependent on its molecular subtypes.

PURPOSE: BMI1, which is a major component of the polycomb group complex 1, is an essential epigenetic repressor of multiple regulatory genes and has been identified as a cancer stem cell (CSC) marker in several cancers. However, its role in breast cancer (BC) remains to be defined. In this study, we have evaluated the prognostic significance of BMI1 among the different molecular subtypes and assessed its association with other breast CSC markers (BCSC). MATERIAL AND METHOD: BMI1 copy number and mRNA was assessed in large and well-characterised cohorts of early-stage BC patients [METABRIC (n = 1980) and the Bc-GenExMiner (n = 9616) databases]. BMI1 protein expression was assessed using tissue microarray and immunohistochemistry in a cohort of 870 invasive BC patients with long-term outcome data and the expression of a panel of BCSC markers was monitored. RESULT: BMI1 expression, prognostic significance and its association with BCSC markers were differed between molecular classes. In the luminal oestrogen receptor-positive (ER+) BC, BMI1 showed significantly higher expression compared to ER- tumours. BMI1 showed positive correlation with favourable prognostic features and it was negatively associated with the expression of key BCSC markers (ALDH1A1, CD24, CD44, CD133, SOX10 and SOX9). High expression of BMI1 was associated with longer breast cancer-specific survival (BCSS) independent of other prognostic variables. In the basal triple negative BC subtype, BMI1 expression showed positive association with CD133 and SOX10 and it was significantly associated with shorter BCSS. CONCLUSION: High BMI1 expression is associated with clinicopathological variables and outcome in BC. However, this association is dependent on the molecular subtypes. Further functional assessment to detect its underlying mechanistic roles in BC subtypes is warranted.

The prognostic significance of ALDH1A1 expression in early invasive breast cancer.

AIMS: Aldehyde dehydrogenase family 1 member A1 (ALDH1A1) is reportedly a key ALDH isozyme linked to the cancer stem cells (CSC) of many solid tumours, where it is involved in self-renewal, differentiation and self-protection. In this study, the prognostic significance of ALDH1A1 expression in early invasive breast cancer (BC) and its role as a BC stem cell (BCSC) were evaluated. METHODS AND RESULTS: ALDH1A1 expression was assessed, using immunohistochemistry and tissue microarrays, in a large well-characterised BC cohort. ALDH1A1 mRNA expression was also assessed at transcriptomic levels, utilising data from the Molecular Taxonomy of Breast Cancer International Consortium. The associations of ALDH1A1 with clinicopathological parameters, other stem cell markers and patient outcomes were determined. ALDH1A1 was expressed in 71% of BC cases at both the protein and mRNA levels. High ALDH1A1 expression was associated with poor prognostic features, including high grade, poor Nottingham Prognostic Index (NPI), lymph node metastasis and highly proliferative ER+ (luminal B) and triple-negative (TNBC) subtypes. ALDH1A1 expression was positively correlated with the expression of CD44, CD24, TWIST, SOX9, EPCAM and CD133. The high immunoexpression of ALDH1A1 was significantly associated with poor BC-specific survival (P < 0.001), and specifically in the luminal B and TNBC subtypes (P = 0.042 and P = 0.003, respectively). The immunoexpression of ALDH1A1 was an independent predictor of poor prognosis (P = 0.015). CONCLUSIONS: ALDH1A1, as assessed using immunohistochemistry, seems to act as a BCSC marker associated not only with other BCSC markers but also with poor prognostic characteristics and poor outcomes, particularly in the luminal B and TNBC subtypes.

The ITIM-Containing Receptor: Leukocyte-Associated Immunoglobulin-Like Receptor-1 (LAIR-1) Modulates Immune Response and Confers Poor Prognosis in Invasive Breast Carcinoma.

BACKGROUND: The leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) plays a role in immune response homeostasis, extracellular matrix remodelling and it is overexpressed in many high-grade cancers. This study aimed to elucidate the biological and prognostic role of LAIR-1 in invasive breast cancer (BC). METHODS: The biological and prognostic effect of LAIR-1 was evaluated at the mRNA and protein levels using well-characterised multiple BC cohorts. Related signalling pathways were evaluated using in silico differential gene expression and siRNA knockdown were used for functional analyses. RESULTS: High LAIR-1 expression either in mRNA or protein levels were associated with high tumour grade, poor Nottingham Prognostic Index, hormone receptor negativity, immune cell infiltrates and extracellular matrix remodelling elements. High LAIR-1 protein expression was an independent predictor of shorter BC-specific survival and distant metastasis-free survival in the entire BC cohort and human epidermal growth factor receptor 2 (HER2)+ subtype. Pathway analysis highlights LAIR-1 association with extracellular matrix remodelling-receptor interaction, and cellular proliferation. Depletion of LAIR-1 using siRNA significantly reduced cell proliferation and invasion capability in HER2+ BC cell lines. CONCLUSION: High expression of LAIR-1 is associated with poor clinical outcome in BC. Association with immune cells and immune checkpoint markers warrant further studies to assess the underlying mechanistic roles.

Enhanced glutamine uptake influences composition of immune cell infiltrates in breast cancer.

BACKGROUND: Cancer cells must alter their metabolism to support proliferation. Immune evasion also plays a role in supporting tumour progression. This study aimed to find whether enhanced glutamine uptake in breast cancer (BC) can derive the existence of specific immune cell subtypes, including the subsequent impact on patient outcome. METHODS: SLC1A5, SLC7A5, SLC3A2 and immune cell markers CD3, CD8, FOXP3, CD20 and CD68, in addition to PD1 and PDL1, were assessed by using immunohistochemistry on TMAs constructed from a large BC cohort (n = 803). Patients were stratified based on SLC protein expression into accredited clusters and correlated with immune cell infiltrates and patient outcome. The effect of transient siRNA knockdown of SLC7A5 and SLC1A5 on PDL1 expression was evaluated in MDA-MB-231 cells. RESULTS: High SLCs were significantly associated with PDL1 and PD1 +, FOXP3 +, CD68 + and CD20 + cells (p < 0.001). Triple negative (TN), HER2 + and luminal B tumours showed variable associations between SLCs and immune cell types (p ≤ 0.04). The expression of SLCs and PDL1, PD1 +, FOXP3 + and CD68 + cells was associated with poor patient outcome (p < 0.001). Knockdown of SLC7A5 significantly reduced PDL1 expression. CONCLUSION: This study provides data that altered glutamine pathways in BC that appears to play a role in deriving specific subtypes of immune cell infiltrates, which either support or counteract its progression.

The role of PIP5K1α/pAKT and targeted inhibition of growth of subtypes of breast cancer using PIP5K1α inhibitor.

Despite recent improvement in adjuvant therapies, triple-negative, and ER+ subtypes of breast cancer (BC) with metastatic potentials remain the leading cause of BC-related deaths. We investigated the role of phosphatidylinositol-4-phosphate 5-kinase alpha (PIP5Kα), a key upstream factor of PI3K/AKT, and the therapeutic effect of PIP5Kα inhibitor on subtypes of BC. The clinical importance of PIP5K1α and its association with survivals were analyzed using three BC cohorts from Nottingham (n = 913), KM plotter (n = 112) and TCGA (n = 817). Targeted overexpression or knockdown of PIP5K1α were introduced into BC cell lines. The effects of PIP5K1α and its inhibitor on growth and invasion of BC were confirmed by using in vitro assays including proliferation, migration, apoptosis and luciferase reporter assays and in vivo xenograft mouse models. All statistical tests were two-sided. PIP5K1α was associated with poor patient outcome in triple-negative BC (for PIP5K1α protein, p = 0.011 and for mRNA expression, p = 0.028, log-rank test). 29% of triple-negative BC had PIP5K1A gene amplification. Elevated level of PIP5K1α increased expression of pSer-473 AKT (p < 0.001) and invasiveness of triple-negative MDA-MB-231 cells (p < 0.001). Conversely, inhibition of PIP5K1α using its inhibitor ISA-2011B, or via knockdown suppressed growth and invasiveness of MDA-MB-231 xenografts (mean vehicle-treated controls = 2160 mm3, and mean ISA-2011B-treated = 600 mm3, p < 0.001). ISA-2011B-treatment reduced expression of pSer-473 AKT (p < 0.001) and its downstream effectors including cyclin D1, VEGF and its receptors, VEGFR1 and VEGFR2 (p < 0.001) in xenograft tumors. In ER+ cancer cells, PIP5K1α acted on pSer-473 AKT, and was in complexes with VEGFR2, serving as co-factor of ER-alpha to regulate activities of target genes including cyclin D1 and CDK1. Our study suggests that our developed PIP5K1α inhibitor has a great potential on refining targeted therapeutics for treatment of triple-negative and ER+ BC with abnormal PI3K/AKT pathways.

Overexpression of the cancer stem cell marker CD133 confers a poor prognosis in invasive breast cancer.

PURPOSE: CD133/ prominin 1 is a cancer stem cell marker associated with cancer progression and patient outcome in a variety of solid tumours, but its role in invasive breast cancer (BC) remains obscure. The current study aims to assess the prognostic value of CD133 expression in early invasive BC. METHODS: CD133 mRNA was assessed in the METABRIC cohort and at the proteomic level using immunohistochemistry utilising a large well-characterised BC cohort. Association with clinicopathological characteristics, expression of other stem cell markers and patient outcome were evaluated. RESULTS: High expression of CD133 either in mRNA or protein levels was associated with characteristics of poor prognosis including high tumour grade, larger tumour size, high Nottingham Prognostic Index, HER2 positivity and hormonal receptor negativity (all; p < 0.001). High CD133 expression was positively associated with proliferation biomarkers including p16, Cyclin E and Ki67 (p < 0.01). Tumours expressing CD133 showed higher expression of other stem cell markers including CD24, CD44, SOX10, ALDHA3 and ITGA6. High expression of CD133 protein was associated with shorter BC-specific survival (p = 0.026). Multivariate analysis revealed that CD133 protein expression was an independent risk factor for shorter BC-specific survival (p = 0.038). CONCLUSION: This study provides evidence for the prognostic value of CD133 in invasive BC. A strong positive association of BC stem cell markers is observed at the protein level. Further studies to assess the value of stem cell markers individually or in combination in BC is warranted.

Heterogeneity of tumour-infiltrating lymphocytes in breast cancer and its prognostic significance.

BACKGROUND AND AIMS: Tumour-infiltrating lymphocytes (TILs) in breast cancer (BC) provide prognostic and predictive information. The aim of this study was to assess the spatial and temporal heterogeneity of TILs in BC and its relationship with immune cell subtypes. METHODS AND RESULTS: Immunohistochemically defined immune cell subtypes, i.e. those expressing T-cell markers (CD3, CD8, and FOXP3), a B-cell marker (CD20) and a histiocytic marker (CD68), were evaluated in a large series (n = 1165) of invasive BCs. A subset of full-face haematoxylin and eosin (H&E)-stained slides were examined for TILs heterogeneity within primary tumours and the corresponding local recurrent carcinomas to investigate spatial and temporal TILs heterogeneity. H&E-stained sections from multiple tumour blocks (three or four blocks per case) representing different tumour areas were evaluated to assess TILs interslide heterogeneity and intraslide heterogeneity. Both average stromal TILs (AV-TILs) and hotspot stromal TILs (HS-TILs) were assessed. AV-TILs showed associations with all immune cell subtypes; however, CD3+ cells constituted the main component (mean number of CD3+ was 55), whereas CD20+ cells constituted the smallest component (mean number of CD20 was 13). There was no significant statistical difference between TILs across tumour blocks of the same case (P = 0.251 for AV-TILs and P = 0.162 for HS-TILs). Triple-negative breast cancer (TNBC) showed higher TILs percentage than other BC subtypes (P < 0.001). High AV-TILs, CD3+ cells, CD8+ cells and CD20+ cells were associated with longer survival in TNBC patients (P < 0.05). High AV-TILs in recurrent tumours showed a significant association with shorter post-recurrence survival (P = 0.004). CONCLUSIONS: Despite the heterogeneity of immune cell type components, average TILs in one full-face H&E-stained section reliably represent TILs in the whole tumour. TILs were associated with outcome in TNBC patients, as well as having prognostic significance for recurrent tumours.

Breast cancer intratumour heterogeneity: current status and clinical implications.

Breast cancer (BC) is a heterogeneous disease that varies in presentation, morphological features, behaviour, and response to therapy. High-throughput molecular profiling studies have revolutionised our understanding of BC heterogeneity, and have demonstrated that molecular profiles of tumours are variable not only between tumours, but also within individual tumours. Current evidence indicates that spatial and temporal intratumour heterogeneity of BC exists at levels beyond what are commonly expected. Intratumour heterogeneity poses critical challenges in the diagnosis, prediction of behaviour and management of BC. For instance, heterogeneous expression of oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 can be seen not only in primary tumours between different regions, but also between primary tumours and their corresponding metastatic/recurrent lesions. The demonstration of molecularly distinct subclones within individual tumours may explain, at least in part, the mechanisms controlling the variable behaviour of BC, and may change our approach to BC sampling and treatment. In this review, BC intratumour heterogeneity is highlighted, with a special emphasis on the current knowledge pertaining to the relationship between intratumour heterogeneity and BC pathogenesis, evolution, and progression, with consideration of its impact on disease diagnosis, management, and the emergence of novel therapeutic targets. The key role of high-throughput molecular and imaging techniques is also addressed.