NF-κB, stem cells and breast cancer: the links get stronger

Cell plasticity modulation by flavonoids in resistant breast carcinoma targeting the nuclear factor kappa B signaling

Cancer cell plasticity plays a crucial role in tumor initiation, progression, and metastasis and is implicated in the multiple cancer defense mechanisms associated with therapy resistance and therapy evasion. Cancer resistance represents one of the significant obstacles in the clinical management of cancer. Some reversal chemosensitizing agents have been developed to resolve this serious clinical problem, but they have not yet been proven applicable in oncological practice. Activated nuclear factor kappa B (NF-κB) is a frequently observed biomarker in chemoresistant breast cancer (BC). Therefore, it denotes an attractive cellular target to mitigate cancer resistance. We summarize that flavonoids represent an essential class of phytochemicals that act as significant regulators of NF-κB signaling and negatively affect the fundamental cellular processes contributing to acquired cell plasticity and drug resistance. In this regard, flavokawain A, icariin, alpinetin, genistein, wogonin, apigenin, oroxylin A, xanthohumol, EGCG, hesperidin, naringenin, orientin, luteolin, delphinidin, fisetin, norwogonin, curcumin, cardamonin, methyl gallate and catechin-3-O-gallate, ampelopsin, puerarin, hyperoside, baicalein, paratocarpin E, and kaempferol and also synthetic flavonoids such as LFG-500 and 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone have been reported to specifically interfere with the NF-κB pathway with complex signaling consequences in BC cells and could be potentially crucial in re-sensitizing unresponsive BC cases. The targeting NF-κB by above-mentioned flavonoids includes the modification of tumor microenvironment and epithelial-mesenchymal transition, growth factor receptor regulations, and modulations of specific pathways such as PI3K/AKT, MAP kinase/ERK, and Janus kinase/signal transduction in BC cells. Besides that, NF-κB signaling in BC cells modulated by flavonoids has also involved the regulation of ATP-binding cassette transporters, apoptosis, autophagy, cell cycle, and changes in the activity of cancer stem cells, oncogenes, or controlling of gene repair. The evaluation of conventional therapies in combination with plasticity-regulating/sensitizing agents offers new opportunities to make significant progress towards a complete cure for cancer.

Non-coding RNAs mediated inflammation in breast cancers

Breast cancer is the major cancer that affects women all over the world. The awareness over past several decades has led to intensive screening and detection as well as successful treatments. Still, the breast cancer mortality is unacceptable and needs to be urgently addressed. Among many factors, inflammation has often been associated with tumorigenesis, including breast cancer. More than a third of all breast cancer deaths are marked by deregulated inflammation. The exact mechanisms are still not completely known but among the many putative factors, the epigenetic changes, particularly those mediated by non-coding RNAs are fascinating. microRNAs, long non-coding RNAs as well as circular RNAs seem to impact the inflammation in breast cancer which further highlights their important regulatory role in breast cancer pathogenesis. Understanding inflammation in breast cancer and its regulation by non-coding RNAs is the primary objective of this review article. We attempt to provide the most complete information on the topic in hopes of opening new areas of research and discoveries.

Infliximab, a Monoclonal Antibody against TNF-α, Inhibits NF-κB Activation, Autotaxin Expression and Breast Cancer Metastasis to Lungs

An inflammatory milieu in the tumor microenvironment leads to immune evasion, resistance to cell death, metastasis and poor prognosis in breast cancer patients. TNF-α is a proinflammatory cytokine that regulates multiple aspects of tumor biology from initiation to progression. TNF-α-induced NF-κB activation initiates inflammatory pathways, which determine cell survival, death and tumor progression. One candidate pathway involves the increased secretion of autotaxin, which produces lysophosphatidate that signals through six G-protein-coupled receptors. Significantly, autotaxin is one of the 40-50 most upregulated genes in metastatic tumors. In this study, we investigated the effects of TNF-α by blocking its action with a monoclonal antibody, Infliximab, and studied the effects on autotaxin secretion and tumor progression. Infliximab had little effect on tumor growth, but it decreased lung metastasis by 60% in a syngeneic BALB/c mouse model using 4T1 breast cancer cells. Infliximab-treated mice also showed a decrease in proliferation and metastatic markers like Ki-67 and vimentin in tumors. This was accompanied by decreases in NF-κB activation, autotaxin expression and the concentrations of plasma and tumor cytokines/chemokines which are involved in metastasis. We also demonstrated a positive correlation of TNF-α -NF-κB and ATX expression in breast cancer patients using cancer databases. Studies in vitro showed that TNF-α-induced NF-κB activation increases autotaxin expression and the clone forming ability of 4T1 breast cancer cells. This report highlights the potential role of Infliximab as an additional approach to attenuate signaling through the autotaxin-lysophosphatidate-inflammatory cycle and decrease mortality from metastatic cancer.

Modulatory Effect of Vitamin C on Hypoxia Induced Breast Cancer Stem Cells

Purpose

Eliminating cancer stem cells (CSCs) is a challenge because of their enhanced resistance to anti-cancer drugs. Vitamin C, which is insufficient in patients with higher stages of cancer, has been gaining attention as a potential treatment for human malignancies. Hence this study aimed to analyze the effect of high-dose vitamin C treatment on the gene expression level of HIF-1α, NF-κB1, BAX, and DNMT1 in the MCF7 cells undergoing hypoxia, as an inducer of CSCs characteristics. As a result, vitamin C could be possibly used as a promising therapeutic adjuvant.

Methods

Here we first analyzed the breast CSC population alteration in MCF7 cells following hypoxia induction. Then, we evaluated the impact of vitamin C treatment on the gene expression level of four stemness-related genes in hypoxic MCF7 cells.

Results

Our results indicate that vitamin C could reduce proliferation and stemness states in CSCs possibly by induction of apoptotic markers such as BAX, along with attenuating stemness markers, including NF-κB1, and DNMT1 gene expressions.

Conclusion

According to our findings, vitamin C administration would become a new approach to avoiding the stimulation of CSCs during cancer therapies.

Rel-A/PACER/miR 7 Axis May Play a Role in Radiotherapy Treatment in Breast Cancer Patients

Background

Radiotherapy has become the standard form of treatment for breast cancer (BC). Radioresistance is an issue that limits the effectiveness of radiotherapy (RT). Therefore, predictive biomarkers are needed to choose the appropriate RT for the patient. Activation of the proinflammatory transcription factor, nuclear factor-kappa B (NF-κB), is a frequently noted pathway in BC. Investigating the relationship between RT and alterations in gene expression involved in the immune pathway can help better control the disease. This research investigated the impact of RT on the expression levels of Rel-A, PACER, and miR-7 within the NF-κB signaling pathway.

Methods

Blood samples (n = 15) were obtained from BC patients during four different time intervals: 72 hours prior to initiating RT, as well as one, two, and four weeks following RT completion. Samples were also collected from 20 healthy women who had no immune or cancer-related diseases. Blood RNA was extracted, and complementary DNA was synthesized. Gene expression level was determined using R real-time polymerase chain reaction (RT-PCR).

Results

There was a significant difference in the expression level of Rel-A between patients and normal individual blood samples (p < 0.05). After four weeks of RT, qRT-PCR revealed a significant downregulation of miR-7 and upregulation of Rel-A and PACER in BC patients. Also, there was a significant association between Rel-A expression and monocyte numbers during RT (p < 0.001).

Conclusion

The expression level of PACER, miR-7 and Rel-A, changed after RT; therefore, these genes could be used as diagnostic and therapeutic RT markers in BC.

Rel-A/PACER/miR 7 Axis May Play a Role in Radiotherapy Treatment in Breast Cancer Patients

Background

Radiotherapy has become the standard form of treatment for breast cancer (BC). Radioresistance is an issue that limits the effectiveness of radiotherapy (RT). Therefore, predictive biomarkers are needed to choose the appropriate RT for the patient. Activation of the proinflammatory transcription factor, nuclear factor-kappa B (NF-κB), is a frequently noted pathway in BC. Investigating the relationship between RT and alterations in gene expression involved in the immune pathway can help better control the disease. This research investigated the impact of RT on the expression levels of Rel-A, PACER, and miR-7 within the NF-κB signaling pathway.

Methods

Blood samples (n = 15) were obtained from BC patients during four different time intervals: 72 hours prior to initiating RT, as well as one, two, and four weeks following RT completion. Samples were also collected from 20 healthy women who had no immune or cancer-related diseases. Blood RNA was extracted, and complementary DNA was synthesized. Gene expression level was determined using R real-time polymerase chain reaction (RT-PCR).

Results

There was a significant difference in the expression level of Rel-A between patients and normal individual blood samples (p < 0.05). After four weeks of RT, qRT-PCR revealed a significant downregulation of miR-7 and upregulation of Rel-A and PACER in BC patients. Also, there was a significant association between Rel-A expression and monocyte numbers during RT (p < 0.001).

Conclusion

The expression level of PACER, miR-7 and Rel-A, changed after RT; therefore, these genes could be used as diagnostic and therapeutic RT markers in BC.

Innovative Thiosemicarbazones that Induce Multi-Modal Mechanisms to Down-Regulate Estrogen-, Progesterone-, Androgen- and Prolactin-Receptors in Breast Cancer

The estrogen receptor-α (ER-α) is a key driver of breast cancer (BC) and the ER-antagonist, tamoxifen, is a central pillar of BC treatment. However, cross-talk between ER-α, other hormone and growth factor receptors enables development of de novo resistance to tamoxifen. Herein, we mechanistically dissect the activity of a new class of anti-cancer agents that inhibit multiple growth factor receptors and down-stream signaling for the treatment of ER-positive BC. Using RNA sequencing and comprehensive protein expression analysis, we examined the activity of di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), on the expression and activation of hormone and growth factor receptors, co-factors, and key resistance pathways in ER-α-positive BC. DpC differentially regulated 106 estrogen-response genes, and this was linked to decreased mRNA levels of 4 central hormone receptors involved in BC pathogenesis, namely ER, progesterone receptor (PR), androgen receptor (AR), and prolactin receptor (PRL-R). Mechanistic investigation demonstrated that due to DpC and Dp44mT binding metal ions, these agents caused a pronounced decrease in ER-α, AR, PR, and PRL-R protein expression. DpC and Dp44mT also inhibited activation and down-stream signaling of the epidermal growth factor (EGF) family receptors, and expression of co-factors that promote ER-α transcriptional activity, including SRC3, NF-κB p65, and SP1. In vivo, DpC was highly tolerable and effectively inhibited ER-α-positive BC growth. Through bespoke, non-hormonal, multi-modal mechanisms, Dp44mT and DpC decrease the expression of PR, AR, PRL-R, and tyrosine kinases that act with ER-α to promote BC, constituting an innovative therapeutic approach.

Cancer plasticity: Investigating the causes for this agility

Cancer is not a hard-wired phenomenon but an evolutionary disease. From the onset of carcinogenesis, cancer cells continuously adapt and evolve to satiate their ever-growing proliferation demands. This results in the formation of multiple subtypes of cancer cells with different phenotypes, cellular compositions, and consequently displaying varying degrees of tumorigenic identity and function. This phenomenon is referred to as cancer plasticity, during which the cancer cells exist in a plethora of cellular states having distinct phenotypes. With the advent of modern technologies equipped with enhanced resolution and depth, for example, single-cell RNA-sequencing and advanced computational tools, unbiased cancer profiling at a single-cell resolution are leading the way in understanding cancer cell rewiring both spatially and temporally. In this review, the processes and mechanisms that give rise to cancer plasticity include both intrinsic genetic factors such as epigenetic changes, differential expression due to changes in DNA, RNA, or protein content within the cancer cell, as well as extrinsic environmental factors such as tissue perfusion, extracellular milieu are detailed and their influence on key cancer plasticity hallmarks such as epithelial-mesenchymal transition (EMT) and cancer cell stemness (CSCs) are discussed. Due to therapy evasion and drug resistance, tumor heterogeneity caused by cancer plasticity has major therapeutic ramifications. Hence, it is crucial to comprehend all the cellular and molecular mechanisms that control cellular plasticity. How this process evades therapy, and the therapeutic avenue of targeting cancer plasticity must be diligently investigated.

Inside the stemness engine: Mechanistic links between deregulated transcription factors and stemness in cancer

Cell identity is largely determined by its transcriptional profile. In tumour, deregulation of transcription factor expression and/or activity enables cancer cell to acquire a stem-like state characterised by capacity to self-renew, differentiate and form tumours in vivo. These stem-like cancer cells are highly metastatic and therapy resistant, thus warranting a more complete understanding of the molecular mechanisms downstream of the transcription factors that mediate the establishment of stemness state. Here, we review recent research findings that provide a mechanistic link between the commonly deregulated transcription factors and stemness in cancer. In particular, we describe the role of master transcription factors (SOX, OCT4, NANOG, KLF, BRACHYURY, SALL, HOX, FOX and RUNX), signalling-regulated transcription factors (SMAD, β-catenin, YAP, TAZ, AP-1, NOTCH, STAT, GLI, ETS and NF-κB) and unclassified transcription factors (c-MYC, HIF, EMT transcription factors and P53) across diverse tumour types, thereby yielding a comprehensive overview identifying shared downstream targets, highlighting unique mechanisms and discussing complexities.

Long noncoding RNA HOTAIR regulates the stemness of breast cancer cells via activation of the NF-κB signaling pathway

Breast cancer is the most prevalent cancer among women, and it is characterized by a high rate of tumor development and heterogeneity. Breast cancer stem cells (CSCs) may well contribute to these pathological properties, but the mechanisms underlying their self-renewal and maintenance are still elusive. Here, we found that the long noncoding RNA HOTAIR is highly expressed in breast CSCs. HOTAIR is required for breast CSC self-renewal and tumor propagation. Mechanistically, we demonstrate that HOTAIR recruits the PRC2 protein complex to the promoter of IκBα to inhibit its expression, leading to activation of the NF-κB signaling pathway. The activated NF-κB signaling promotes downstream c-Myc and Cyclin D1 expression. Furthermore, our analysis of clinical samples from the GEPIA database indicated that the IκBα level, as well as the survival rate of patients, with high HOTAIR expression was significantly lower than that of patients with relatively low HOTAIR expression. Our data suggest that HOTAIR-mediated NF-κB signaling primes breast CSC self-renewal and tumor propagation. In sum, we have identified HOTAIR-based NF-κB signaling regulatory circuit that promotes tumorigenic activity in breast CSCs, further indicating that HOTAIR could be a promising target for clinical treatment of breast cancers.

Higher Expressions of SHH and AR Are Associated with a Positive Receptor Status and Have Impact on Survival in a Cohort of Croatian Breast Cancer Patients

Breast cancers (BC) are usually classified into four molecular subtypes according to the expression of estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER2) receptors and proliferation marker Ki-67. Despite available anti-hormonal therapies and due to the inherent propensity of some subtypes to develop metastasis, there is a permanent need to discover new prognostic and predictive biomarkers, as well as therapeutic targets for BC. In this study, we used immunohistochemical staining to determine the expression of androgen receptor (AR) and sonic hedgehog protein (SHH), the main ligand of the Hedgehog-GLI (HH-GLI) signaling pathway, in 185 archival primary BC tissue samples and correlated it with clinicopathological characteristics, molecular subtypes, receptors statuses, and survival in a cohort of Croatian BC patients. Results showed that higher SHH and AR expressions were associated with positive receptor status, but increased SHH expression had a negative impact on survival in receptor-negative BCs. On the contrary, higher AR expression was mostly protective. However, multivariate analysis showed that only higher AR expression could be considered as an independent prognostic biomarker for poorer overall survival in triple-negative breast cancer patients (TNBC) (HR 10.9, 95% CI 1.43-83.67; p = 0.021), what could be Croatian population-related. SHH could be a potential target for treating TNBCs and HER2-enriched BCs, in cases where HH-GLI signaling is canonical (SHH-dependent).

Crocin attenuates NF-κB-mediated inflammation and proliferation in breast cancer cells by down-regulating PRKCQ

Breast cancer (BC) is the most commonly diagnosed cancer confronting women worldwide. Crocin, a glycosylated carotenoid extracted from Crocus sativus L., possesses anti-cancer and anti-inflammatory activities. This study tried to explore the influences of crocin on proliferation and inflammation of BC cells, and to investigate the possible mechanism. The protein levels of protein kinase C theta (PRKCQ) and nuclear factor kappa B (NF-κB) p-p65 and p65 were examined using western blot analysis. The potential targets of crocin were predicted using the PharmMapper database. Cell viability and proliferation were determined utilizing CCK-8 and EdU incorporation assays, respectively. Inflammation was assessed by detecting the levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) using RT-qPCR and ELISA. Results showed that crocin inhibited NF-κB activation and suppressed cell viability and proliferation in BC cells. Crocin caused a significant reduction of levels of TNF-α and IL-1β, suggesting that crocin suppressed inflammation in BC cells. NF-κB inhibition decreased proliferation and inflammation in BC cells. Additionally, PRKCQ was identified as a potential target of crocin according to PharmMapper database. Crocin treatment inhibited the activation of NF-κB in BC cells by reducing PRKCQ expression. Mechanistically, PRKCQ-dependent activation of NF-κB pathway reversed the effects of crocin on the proliferation and inflammation in BC cells. In conclusion, crocin inhibited NF-κB-mediated inflammation and proliferation in BC cells through reducing PRKCQ expression.

MUC1 is a potential target to overcome trastuzumab resistance in breast cancer therapy

Although resistance is its major obstacle in cancer therapy, trastuzumab is the most successful agent in treating epidermal growth factor receptor 2 positive (HER2 +) breast cancer (BC). Some patients show resistance to trastuzumab, and scientists want to circumvent this problem. This review elaborately discusses possible resistance mechanisms to trastuzumab and introduces mucin 1 (MUC1) as a potential target efficient for overcoming such resistance. MUC1 belongs to the mucin family, playing the oncogenic/mitogenic roles in cancer cells and interacting with several other oncogenic receptors and pathways, such as HER2, β-catenin, NF-κB, and estrogen receptor (ERα). Besides, it has been established that MUC1- Cytoplasmic Domain (MUC1-CD) accelerates the development of resistance to trastuzumab and that silencing MUC1-C proto-oncogene is associated with increased sensitivity of HER2⁺ cells to trastuzumab-induced growth inhibitors. We mention why targeting MUC1 can be useful in overcoming trastuzumab resistance in cancer therapy.

Elevated EDAR signalling promotes mammary gland tumourigenesis with squamous metaplasia

Ectodysplasin A receptor (EDAR) is a death receptor in the Tumour Necrosis Factor Receptor (TNFR) superfamily with roles in the development of hair follicles, teeth and cutaneous glands. Here we report that human Oestrogen Receptor (ER) negative breast carcinomas which display squamous differentiation express EDAR strongly. Using a mouse model with a high Edar copy number, we show that elevated EDAR signalling results in a high incidence of mammary tumours in breeding female mice. These tumours resemble the EDAR-high human tumours in that they are characterised by a lack of oestrogen receptor expression, contain extensive squamous metaplasia, and display strong β-catenin transcriptional activity. In the mouse model, all of the tumours carry somatic deletions of the third exon of the CTNNB1 gene that encodes β-catenin. Deletion of this exon yields unconstrained β-catenin signalling activity. We also demonstrate that β-catenin activity is required for transformed cell growth, showing that increased EDAR signalling creates an environment in which β-catenin activity can readily promote tumourigenesis. Together, this work identifies a novel death receptor oncogene in breast cancer, whose mechanism of transformation is based on the interaction between the WNT and Ectodysplasin A (EDA) pathways.

Ubiquitination of NF-κB p65 by FBXW2 suppresses breast cancer stemness, tumorigenesis, and paclitaxel resistance

The F-box and WD-repeat-containing protein 2 (FBXW2) plays a crucial role as an E3 ligase in regulating tumorigenesis. However, the functions of FBXW2 in breast cancer are still unknown. Here, we find that nuclear factor-kB (NF-κB) p65 is a new substrate of FBXW2. FBXW2 directly binds to p65, leading to its ubiquitination and degradation. Interestingly, p300 acetylation of p65 blocks FBXW2 induced p65 ubiquitination. FBXW2-p65 axis is a crucial regulator of SOX2-induced stemness in breast cancer. Moreover, FBXW2 inhibits breast tumor growth by regulating p65 degradation in vitro and in vivo. FBXW2 overexpression abrogates the effects of p65 on paclitaxel resistance in vitro and in vivo. Furthermore, FBXW2 induced p65 degradation is also confirmed in FBXW2-knockout mice. Our results identify FBXW2 as an important E3 ligase for p65 degradation, which provide insights into the tumor suppressor functions of FBXW2 in breast cancer.

Global signalling network analysis of luminal T47D breast cancer cells in response to progesterone

BACKGROUND

Breast cancer cells enter into the cell cycle following progestin exposure by the activation of signalling cascades involving a plethora of enzymes, transcription factors and co-factors that transmit the external signal from the cell membrane to chromatin, ultimately leading to a change of the gene expression program. Although many of the events within the signalling network have been described in isolation, how they globally team up to generate the final cell response is unclear.

METHODS

In this study we used antibody microarrays and phosphoproteomics to reveal a dynamic global signalling map that reveals new key regulated proteins and phosphor-sites and links between previously known and novel pathways. T47D breast cancer cells were used, and phospho-sites and pathways highlighted were validated using specific antibodies and phenotypic assays. Bioinformatic analysis revealed an enrichment in novel signalling pathways, a coordinated response between cellular compartments and protein complexes.

RESULTS

Detailed analysis of the data revealed intriguing changes in protein complexes involved in nuclear structure, epithelial to mesenchyme transition (EMT), cell adhesion, as well as transcription factors previously not associated with breast cancer cell proliferation. Pathway analysis confirmed the key role of the MAPK signalling cascade following progesterone and additional hormone regulated phospho-sites were identified. Full network analysis shows the activation of new signalling pathways previously not associated with progesterone signalling in T47D breast cancer cells such as ERBB and TRK. As different post-translational modifications can mediate complex crosstalk mechanisms and massive PARylation is also rapidly induced by progestins, we provide details of important chromatin regulatory complexes containing both phosphorylated and PARylated proteins.

CONCLUSIONS

This study contributes an important resource for the scientific community, as it identifies novel players and connections meaningful for breast cancer cell biology and potentially relevant for cancer management.

Olfactory receptor 5B21 drives breast cancer metastasis

Olfactory receptors (ORs), responsible for the sense of smell, play an essential role in various physiological processes outside the nasal epithelium, including cancer. In breast cancer, however, the expression and function of ORs remain understudied. We examined the significance of OR transcript abundance in primary and metastatic breast cancer to the brain, bone, and lung. Although 20 OR transcripts were differentially expressed in distant metastases, OR5B21 displayed an increased transcript abundance in all three metastatic sites compared with the primary tumor. Knockdown of OR5B21 significantly decreased the invasion and migration of breast cancer cells as well as metastasis to different organs especially the brain, whereas increasing of OR5B21 transcript abundance had the opposite effect. Mechanistically, OR5B21 expression was associated with epithelial to mesenchymal transition through the STAT3/NF-κB/CEBPβ signaling axis. We propose OR5B21 (and potentially other ORs) as a novel oncogene contributing to breast cancer metastasis and a potential target for adjuvant therapy.

Body mass index and type 2 diabetes and breast cancer survival: a Mendelian randomization study

The causal relationship between body mass index (BMI) and type 2 diabetes (T2D) and breast cancer prognosis is still ambiguous. The aim of this study was to investigate the prognostic effect of BMI and T2D on breast cancer disease-free survival (DFS) among Asian individuals. In this two-sample Mendelian randomization (MR) study, the instrumental variables (IVs) were identified using a genome-wide association study (GWAS) among 24,000 participants in the Taiwan Biobank. Importantly, the validity of these IVs was confirmed with a previous large-scale GWAS (Biobank Japan Project, BBJ). In this study, we found that a genetic predisposition toward higher BMI (as indicated by BMI IVs, F = 86.88) was associated with poor breast cancer DFS (hazard ratio [HR] = 6.11; P < 0.001). Furthermore, higher level of genetically predicted T2D (as indicated by T2D IVs) was associated with an increased risk of recurrence of and mortality from breast cancer (HR = 1.43; P < 0.001). Sensitivity analyses, including the weighted-median approach, MR-Egger regression, Radial regression and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) supported the consistency of our findings. Finally, the causal relationship between BMI and poor breast cancer prognosis was confirmed in a prospective cohort study. Our MR analyses demonstrated the causal relationship between the genetic prediction of elevated BMI and a greater risk of T2D with poor breast cancer prognosis. BMI and T2D have important clinical implications and may be used as prognostic indicators of breast cancer.

DEAD-box helicase 27 enhances stem cell-like properties with poor prognosis in breast cancer

Background

Although the rapid development of diagnosis and treatment has improved prognosis in early breast cancer, challenges from different therapeutic response remain due to breast cancer heterogeneity. DEAD-box helicase 27 (DDX27) had been proved to influence ribosome biogenesis and identified as a promoter in gastric and colorectal cancer associated with stem cell-like properties, while the impact of DDX27 on breast cancer prognosis and biological functions is unclear. We aimed to explore the influence of DDX27 on stem cell-like properties and prognosis in breast cancer.

Methods

The expression of DDX27 was evaluated in 24 pairs of fresh breast cancer and normal tissue by western blot. We conducted Immunohistochemical (IHC) staining in paraffin sections of 165 breast cancer patients to analyze the expression of DDX27 and its correlation to stemness biomarker. The Cancer Genome Atlas-Breast Cancer (TCGA-BRCA) database and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database were used to analyze the expression of DDX27 in breast cancer. Kaplan–Meier survival analysis were used to investigate the implication of DDX27 on breast cancer prognosis. Western blot, CCK-8 assay, Transwell assay and wound-healing assay were carried out to clarify the regulation of DDX27 on stem cell-like properties in breast cancer cells. Gene Set Enrichment Analysis (GSEA) was performed to analyze the potential molecular mechanisms of DDX27 in breast cancer.

Results

DDX27 was significantly high expressed in breast cancer compared with normal tissue. High expression of DDX27 was related to larger tumor size (p = 0.0005), positive lymph nodes (p = 0.0008), higher histological grade (p = 0.0040), higher ki-67 (p = 0.0063) and later TNM stage (p < 0.0001). Patients with high DDX27 expression turned out a worse prognosis on overall survival (OS, p = 0.0087) and disease-free survival (DFS, p = 0.0235). Overexpression of DDX27 could enhance the expression of biomarkers related to stemness and promote stem cell-like activities such as proliferation and migration in breast cancer cells.

Conclusion

DDX27 can enhance stem cell-like properties and cause poor prognosis in breast cancer, also may be expected to become a potential biomarker for breast cancer therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03011-0.

Disabling the Nuclear Translocalization of RelA/NF-κB by a Small Molecule Inhibits Triple-Negative Breast Cancer Growth

INTRODUCTION

Constitutive activation of NF-κB has been implicated as being contributive to cancer cell growth, drug resistance, and tumor recurrence in many cancers including breast cancer. Activation of NF-κB leads to nuclear translocation of RelA, a critical component of the NF-κB transcription factor complex, which subsequently binds to specific DNA sites and activates a multitude of genes involved in diverse cell functions. Studies show that triple-negative breast cancer (TNBC) cells possess constitutively active NF-κB and concomitantly have higher levels of nuclear localization of RelA than cytoplasmic RelA. This feature is considered to be associated with the response to chemotherapy. However, currently, there is no specific inhibitor to block nuclear translocation of RelA.

METHODS

A structure-based approach was used to develop a small-molecule inhibitor of RelA nuclear translocation. The interaction between this molecule and RelA was verified biophysically through isothermal titration calorimetry and microscale thermophoresis. TNBC cell lines MDA-MB-231 and MDA-MB-468 and a human TNBC xenograft model were used to verify in vitro and in vivo efficacy of the small molecule, respectively.

RESULTS

We found that the small molecule, CRL1101, bound specifically to RelA as indicated by the biophysical assays. Further, CRL1101 blocked RelA nuclear translocation in breast cancer cells in vitro, and markedly reduced breast tumor growth in a triple-negative breast cancer xenograft model.

CONCLUSION

Our study demonstrates that CRL1101 may lead to new NF-κB-targeted therapeutics for TNBC. Further, blocking of nuclear translocation of shuttling transcription factors may be a useful general strategy in cancer drug development.

Cancer-Associated Fibroblasts Modulate Transcriptional Signatures Involved in Proliferation, Differentiation and Metastasis in Head and Neck Squamous Cell Carcinoma

Simple Summary

Cancer-associated fibroblasts (CAFs) are the major cellular component of the tumor microenvironment and have been shown to stimulate tumor growth, epithelial-to-mesenchymal transition (EMT), invasion, and radio-resistance. Radio-resistance leading to disease relapse is one of the major challenges in long-term survival and outcome in head and neck squamous cell carcinoma (HNSCC). Therefore, it is essential to search for predictive markers and new targets for treatment using clinically relevant in vitro tumor models. We show that CAFs alter the expression of HNSCC tumor cell genes, many of which are associated with proliferation, differentiation, and metastasis. Moreover, the expression pattern of selected CAF-regulated genes differed between HNSCC tumor tissue and the adjacent non-tumoral tissue. Two CAF-regulated genes, MMP9 and FMOD, were found to be associated with overall survival (OS) in patients treated with radiotherapy.

Abstract

Cancer-associated fibroblasts (CAFs) are known to increase tumor growth and to stimulate invasion and metastasis. Increasing evidence suggests that CAFs mediate response to various treatments. HNSCC cell lines were co-cultured with their patient-matched CAFs in 2D and 3D in vitro models, and the tumor cell gene expression profiles were investigated by cDNA microarray and qRT-PCR. The mRNA expression of eight candidate genes was examined in tumor biopsies from 32 HNSCC patients and in five biopsies from normal oral tissue. Differences in overall survival (OS) were tested with Kaplan–Meier long-rank analysis. Thirteen protein coding genes were found to be differentially expressed in tumor cells co-cultured with CAFs in 2D and 81 in 3D when compared to tumor cells cultured without CAFs. Six of these genes were upregulated both in 2D and 3D (POSTN, GREM1, BGN, COL1A2, COL6A3, and COL1A1). Moreover, two genes upregulated in 3D, MMP9 and FMOD, were significantly associated with the OS. In conclusion, we demonstrated in vitro that CAF-derived signals alter the tumor cell expression of multiple genes, several of which are associated with differentiation, epithelial-to-mesenchymal transition (EMT) phenotype, and metastasis. Moreover, six of the most highly upregulated genes were found to be overexpressed in tumor tissue compared to normal tissue.

13R,20-Dihydroxydocosahexaenoic Acid, a Novel Dihydroxy- DHA Derivative, Inhibits Breast Cancer Stemness through Regulation of the Stat3/IL-6 Signaling Pathway by Inducing ROS Production

Breast cancer is a major health problem worldwide. Cancer stem cells (CSCs) are known to mediate breast cancer metastasis and recurrence and are therefore a promising therapeutic target. In this study, we investigated the anti-inflammatory effect of 13R,20-dihydroxydocosahexaenoic acid (13R,20-diHDHA), a novel dihydroxy-DHA derivative, which was synthesized through an enzymatic reaction using cyanobacterial lipoxygenase. We found that 13R,20-diHDHA reduced the macrophage secretion of the inflammatory cytokines, IL-6 and TNF-α, and thus appeared to have anti-inflammatory effects. As the inflammatory tumor microenvironment is largely devoted to supporting the cancer stemness of breast cancer cells, we investigated the effect of 13R,20-diHDHA on breast cancer stemness. Indeed, 13R,20-diHDHA effectively inhibited breast cancer stemness, as evidenced by its ability to dose-dependently inhibit the mammospheres formation, colony formation, migration, and invasion of breast CSCs. 13R,20-diHDHA reduced the populations of CD44^high/CD24^low and aldehyde dehydrogenase (ALDH)-positive cells and the expression levels of the cancer stemness-related self-renewal genes, Nanog, Sox2, Oct4, c-Myc, and CD44. 13R,20-diHDHA increased reactive oxygen species (ROS) production, and the generated ROS reduced the phosphorylation of nuclear signal transducer and activator of transcription 3 (Stat3) and the secretion of IL-6 by mammospheres. These data collectively suggest that 13R,20-diHDHA inhibits breast cancer stemness through ROS production and downstream regulation of Stat3/IL-6 signaling, and thus might be developed as an anti-cancer agent acting against CSCs.

Deep Pathway Analysis V2.0: A Pathway Analysis Framework Incorporating Multi-Dimensional Omics Data

Pathway analysis is essential in cancer research particularly when scientists attempt to derive interpretation from genome-wide high-throughput experimental data. If pathway information is organized into a network topology, its use in interpreting omics data can become very powerful. In this paper, we propose a topology-based pathway analysis method, called DPA V2.0, which can combine multiple heterogeneous omics data types in its analysis. In this method, each pathway route is encoded as a Bayesian network which is initialized with a sequence of conditional probabilities specifically designed to encode directionality of regulatory relationships defined in the pathway. Unlike other topology-based pathway tools, DPA is capable of identifying pathway routes as representatives of perturbed regulatory signals. We demonstrate the effectiveness of our model by applying it to two well-established TCGA data sets, namely, breast cancer study (BRCA) and ovarian cancer study (OV). The analysis combines mRNA-seq, mutation, copy number variation, and phosphorylation data publicly available for both TCGA data sets. We performed survival analysis and patient subtype analysis and the analysis outcomes revealed the anticipated strengths of our model. We hope that the availability of our model encourages wet lab scientists to generate extra data sets to reap the benefits of using multiple data types in pathway analysis. The majority of pathways distinguished can be confirmed by biological literature. Moreover, the proportion of correctly indentified pathways is 10 percent higher than previous work where only mRNA-seq and mutation data is incorporated for breast cancer patients. Consequently, such an in-depth pathway analysis incorporating more diverse data can give rise to the accuracy of perturbed pathway detection.

Cross Talk between COVID-19 and Breast Cancer

Cancer patients are more susceptible to COVID-19; however, the prevalence of COVID-19 in different types of cancer is still inconsistent and inconclusive. Here, we delineate the intricate relationship between breast cancer and COVID-19. Breast cancer and COVID-19 share the involvement of common comorbidities, hormonal signalling pathways, gender differences, rennin- angiotensin system (RAS), angiotensin-converting enzyme-2 (ACE-2), transmembrane protease serine 2 (TMPRSS2) and dipeptidyl peptidase-IV (DPP-IV). We also shed light on the possible effects of therapeutic modalities of COVID-19 on breast cancer outcomes. Briefly, we conclude that breast cancer patients are more susceptible to COVID-19 in comparison with their normal counterparts. Women are more resistant to the occurrence and severity of COVID-19. Increased expressions of ACE2 and TMPRSS2 are correlated with occurrence and severity of COVID-19, but higher expression of ACE2 and lower expression of TMPRSS2 are prognostic markers for overall disease free survival in breast cancer. The ACE2 inhibitors and ibuprofen therapies for COVID-19 treatment may aggravate the clinical condition of breast cancer patients through chemo-resistance and metastasis. Most of the available therapeutic modalities for COVID-19 were also found to exert positive effects on breast cancer outcomes. Besides drugs in clinical trend, TMPRSS2 inhibitors, estrogen supplementation, androgen deprivation and DPP-IV inhibitors may also be used to treat breast cancer patients infected with SARS-CoV-2. However, drug-drug interactions suggest that some of the drugs used for the treatment of COVID-19 may modulate the drug metabolism of anticancer therapies which may lead to adverse drug reaction events.

Proteomic Analysis of Inflammatory Biomarkers Associated With Breast Cancer Recurrence

INTRODUCTION

Breast cancer is the most frequent cancer detected for women, and while our ability to treat breast cancer has improved substantially over the years, recurrence remains a major obstacle. Standard screening for new and recurrent breast cancer involves clinical breast imaging. However, there is no clinically approved noninvasive body fluid test for the early detection of recurrent breast cancer. Materials and Method: In this study, we analyzed serum samples from both recurrent and nonrecurrent breast cancer patients by different proteomics methods to identify biomarkers in patients with recurrence of disease.

RESULTS

Comparative data analysis identified several histone deacetylase (HDAC) proteins, which were found at significantly higher levels in the serum of recurrent breast cancer patients: HDAC9 (C-term) (P = 0.0035), HDAC5 (C-term) (P = 0.013), small ubiquitin-like modifier 1 (N-term) (P = 0.017), embryonic stem cell-expressed Ras (inter) (P = 0.018), and HDAC7 (C-term) (P = 0.020). Chronic inflammation plays a critical role in the development of the breast cancer recurrence, and we identified several proinflammatory cytokines that were present at elevated levels only in recurrent breast cancer patient serum.

CONCLUSIONS

Our data indicated that the epigenetic regulation of inflammatory processes plays a critical role in breast cancer recurrence. The identified proteins could lay the groundwork for the development of a serum-based breast cancer recurrence assay.

Cancer Stem Cell-Associated Pathways in the Metabolic Reprogramming of Breast Cancer

Metabolic reprogramming of cancer is now considered a hallmark of many malignant tumors, including breast cancer, which remains the most commonly diagnosed cancer in women all over the world. One of the main challenges for the effective treatment of breast cancer emanates from the existence of a subpopulation of tumor-initiating cells, known as cancer stem cells (CSCs). Over the years, several pathways involved in the regulation of CSCs have been identified and characterized. Recent research has also shown that CSCs are capable of adopting a metabolic flexibility to survive under various stressors, contributing to chemo-resistance, metastasis, and disease relapse. This review summarizes the links between the metabolic adaptations of breast cancer cells and CSC-associated pathways. Identification of the drivers capable of the metabolic rewiring in breast cancer cells and CSCs and the signaling pathways contributing to metabolic flexibility may lead to the development of effective therapeutic strategies. This review also covers the role of these metabolic adaptation in conferring drug resistance and metastasis in breast CSCs.

Solvent fractions of selected Ethiopian medicinal plants used in traditional breast cancer treatment inhibit cancer stem cells in a breast cancer cell line

Background

The incidence and mortality of breast cancer in women is increasing worldwide. Breast cancer contains a subpopulation of cells known as cancer stem cells (CSCs). The CSCs are believed to be responsible for chemotherapeutic resistance and are also involved in tumor initiation, progression, evolution, and metastasis to distant sites. The present study aimed to investigate the anti-CSC potential of selected Ethiopian medicinal plants traditionally used for breast cancer treatment.

Methods

The solvent fractions of three medicinal plants (the ethyl acetate fraction of Vernonia leopoldi, the aqueous fraction of Sideroxylon oxyacanthum, and the chloroform fraction of Clematis simensis) resulting from the methanolic crude extracts were selected based on their previously demonstrated cytotoxic effects on breast cancer cell lines. The effect of these solvent fractions on the status of the cancer stem cell subpopulation of the JIMT-1 cell line was assessed by flow cytometric evaluation of the proportion of aldehyde dehydrogenase positive cells and by measuring colony forming efficiency in a serum-free soft agar assay after treatment. Effects on cell migration using a wound healing assay and on tumor necrosis factor-α-induced translocation of nuclear factor-kappa B to the cell nucleus were also investigated.

Results

The solvent fractions showed a dose-dependent reduction in the aldehyde dehydrogenase positive subpopulation of JIMT-1 cells. The chloroform fraction of C. simensis (80 μg/mL) completely blocked colony formation of JIMT-1 cells. The wound healing assay showed that all fractions significantly reduced cell migration. The ethyl acetate fraction of V. leopoldi (0.87 μg/mL) significantly inhibited tumor necrosis factor-α-induced nuclear factor-kappa B translocation to the nucleus.

Conclusion

The solvent fractions of the medicinal plants showed desirable activities against breast cancer stem cells in the JIMT-1 cell line, which warrants further studies.

Differential expression of Oct-4, CD44, and E-cadherin in eutopic and ectopic endometrium in ovarian endometriomas and their correlations with clinicopathological variables

BACKGROUND

Endometriosis is an estrogen-dependent inflammatory disease that often causes infertility and chronic pelvic pain. Although endometriosis is known as a benign disease, it has demonstrated characteristics of malignant neoplasms, including neoangiogenesis, tissue invasion, and cell implantation to distant organs. Octamer-binding protein 4 (Oct-4) is a molecular marker for stem cells that plays an essential role in maintaining pluripotency and self-renewal processes in various types of benign and malignant tissues. CD44 is a multifunctional cell surface adhesion molecule that acts as an integral cell membrane protein and plays a role in cell-cell and cell-matrix interactions. E-cadherin is an epithelial cell-cell adhesion molecule that plays important role in the modulation of cell polarization, cell migration, and cancer metastasis. The aim of this study was to investigate the expression patterns of Oct-4, CD44, and E-cadherin in eutopic and ectopic endometrial tissues from women with endometrioma compared to control endometrial tissues from women without endometrioma.

METHODS

In the present study, Oct-4, CD44, and E-cadherin expressions were evaluated in eutopic and ectopic endometrial tissue samples from women with endometrioma (n = 32) and compared with those of control endometrial tissue samples from women without endometrioma (n = 30).

RESULTS

Immunohistochemical expression of Oct-4 was significantly higher in the ectopic endometrial tissue samples of women with endometrioma than in the control endometrial tissue samples (p = 0.0002). Conversely, CD44 and E-cadherin expressions were significantly lower in the ectopic endometrial tissue samples of women with endometrioma than in the control endometrial tissue samples (p = 0.0137 and p = 0.0060, respectively). Correlation analysis demonstrated significant correlations between Oct-4 expression and endometrioma cyst diameter (p = 0.0162), rASRM stage (p = 0.0343), and total rASRM score (p = 0.0223). Moreover, CD44 expression was negatively correlated with the presence of peritoneal endometriotic lesions (p = 0.0304) while E-cadherin expression was negatively correlated with the presence of deep infiltrating endometriosis (p = 0.0445).

CONCLUSIONS

Increased expression of Oct-4 and decreased expression of adhesion molecules in endometriotic tissues may contribute to the development and progression of endometriosis.

Biomarkers for Inflammatory Breast Cancer: Diagnostic and Therapeutic Utility

Inflammatory breast cancer (IBC) is a rare and highly aggressive subtype of advanced breast cancer. The aggressive behavior, resistance to chemotherapy, angiogenesis, and high metastatic potential are key intrinsic characteristics of IBC caused by many specific factors. Pathogenesis and behavior of IBC are closely related to tumor surrounding inflammatory and immune cells, blood vessels, and extracellular matrix, which are all components of the tumor microenvironment (TME). The tumor microenvironment has a crucial role in the local immune r09esponse. The communication between intrinsic and extrinsic components of IBC and the abundance of cytokines and chemokines in the TME strongly contribute to the aggressiveness and high angiogenic potential of this tumor. Critical modes of interaction are cytokine-mediated communication and direct intercellular contact between cancer cells and tumor microenvironment with a variety of pathway crosstalk. This review aimed to summarize current knowledge of predictive and prognostic biomarkers in IBC.

Dimethyl Fumarate and Its Esters: A Drug with Broad Clinical Utility?

Fumaric acid esters (FAEs) are small molecules with anti-oxidative, anti-inflammatory and immune-modulating effects. Dimethyl fumarate (DMF) is the best characterised FAE and is approved and registered for the treatment of psoriasis and Relapsing-Remitting Multiple Sclerosis (RRMS). Psoriasis and RRMS share an immune-mediated aetiology, driven by severe inflammation and oxidative stress. DMF, as well as monomethyl fumarate and diroximel fumarate, are commonly prescribed first-line agents with favourable safety and efficacy profiles. The potential benefits of FAEs against other diseases that appear pathogenically different but share the pathologies of oxidative stress and inflammation are currently investigated.

Identification of Target Genes Related to Sulfasalazine in Triple-Negative Breast Cancer Through Network Pharmacology

Background

The anti-inflammatory drug sulfasalazine (SAS) has been confirmed to inhibit the growth of triple-negative breast cancer (TNBC), but the mechanism is not clear. The aim of this study was to use network pharmacology to find relevant pathways of SAS in TNBC patients.

Material/Methods

Through screening of the GeneCards, CTD, and ParmMapper databases, potential genes related to SAS and TNBC were identified. In addition, gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed using the R programming language. Protein–protein interaction networks were constructed using Cytoscape. The Kaplan-Meier plotter screened genes related to TNBC prognosis. TNBC patient gene expression profiles and clinical data were downloaded from The Cancer Genome Atlas database. A heatmap was generated using the R programming language that presents the expression of potential target genes in patients with TNBC.

Results

Eighty potential target genes were identified through multiple databases. The bioinformatical analyses predicted the interrelationships, potential pathways, and molecular functions of the genes from multiple aspects, which are associated with physiological processes such as the inflammatory response, metabolism of reactive oxygen species (ROS), and regulation of proteins in the matrix metalloproteinase (MMP) family. Survival analysis showed that 12 genes were correlated with TNBC prognosis. Heatmapping showed that genes such as those encoding members of the MMP family were differentially expressed in TNBC tissues and normal tissues.

Conclusions

Our analysis revealed that the main reasons for the inhibitory effect of SAS on TNBC cells may be inhibition of the inflammatory response and MMP family members and activation of ROS.

The MyD88 inhibitor TJ-M2010-2 suppresses proliferation, migration and invasion of breast cancer cells by regulating MyD88/GSK-3β and MyD88/NF-κB signalling pathways

MyD88 has been implicated in the tumourigenesis, metastasis and recurrence of breast cancer (BC). Here we utilized TJ-M2010-2 (TJ), an inhibitor of MyD88 homodimerimerization, and siMyD88 to suppress the function of MyD88 in MCF-7 and MDA-MB-231 cells. BC cells were treated in vitro and xenografted into nude mice to generate a model in vivo. TJ inhibited BC cell growth by impeding proliferation rather than by promoting apoptosis in vitro. Additionally, TJ and siMyD88 significantly attenuated cell migration and invasion, inhibited EMT-like progression and reduced cytokine (IL-6, IL-8, TGF-β1 and TNF-α) secretion induced by LPS. In vivo, TJ significantly hindered tumour growth in mice. Notably, TJ also decreased the secretion of IL-6, IL-8, TGF-β1, and TNF-α and M2 macrophage infiltration in the tumour microenvironment. The expression of MyD88, TRAF6, NF-κB p65, Snail, MMP-2, MMP-9, p-GSK-3β and p-Akt was significantly downregulated by TJ in BC cells and tumour tissues. Collectively, these results suggest that a MyD88 inhibitor (TJ) may be a promising therapeutic modality for treating BC patients.

CDYL2 Epigenetically Regulates MIR124 to Control NF-κB/STAT3-Dependent Breast Cancer Cell Plasticity

Epigenetic deregulation of gene transcription is central to cancer cell plasticity and malignant progression but remains poorly understood. We found that the uncharacterized epigenetic factor chromodomain on Y-like 2 (CDYL2) is commonly over-expressed in breast cancer, and that high CDYL2 levels correlate with poor prognosis. Supporting a functional role for CDYL2 in malignancy, it positively regulated breast cancer cell migration, invasion, stem-like phenotypes, and epithelial-to-mesenchymal transition. CDYL2 regulation of these plasticity-associated processes depended on signaling via p65/NF-κB and STAT3. This, in turn, was downstream of CDYL2 regulation of MIR124 gene transcription. CDYL2 co-immunoprecipitated with G9a/EHMT2 and GLP/EHMT1 and regulated the chromatin enrichment of G9a and EZH2 at MIR124 genes. We propose that CDYL2 contributes to poor prognosis in breast cancer by recruiting G9a and EZH2 to epigenetically repress MIR124 genes, thereby promoting NF-κB and STAT3 signaling, as well as downstream cancer cell plasticity and malignant progression.

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Up-regulation of CDYL2 is common in breast cancer and correlates with poor prognosis

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CDYL2 regulates enrichment of methyltransferases G9a and EZH2 at MIR124 genes

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microRNA-124 regulation by CDYL2 impacts STAT3 and NF-κB signaling

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CDYL2 regulation of EMT, migration, invasion, and stemness is STAT3/NF-κB dependent

Anti-cancer Activity of Centipeda minima Extract in Triple Negative Breast Cancer via Inhibition of AKT, NF-κB, and STAT3 Signaling Pathways

Breast cancer is the most commonly diagnosed cancer in females worldwide. Estimates from the World Health Organization (WHO) International Agency for Research on Cancer, suggest that globally, there were around 2.1 million new breast cancer cases and 627,000 deaths due to breast cancer in 2018. Among the subtypes of breast cancer, triple negative breast cancer (TNBC) is the most aggressive and carries the poorest prognosis, largest recurrence, and lowest survival rate. Major treatment options for TNBC patients are mainly constrained to chemotherapy, which can be accompanied by severe side effects. Therefore, development of novel and effective anti-cancer drugs for the treatment of TNBC are urgently required. Centipeda minima is a well-known traditional Chinese herbal medicine that has historically been used to treat rhinitis, sinusitis, relieve pain, and reduce swelling. Recent studies have shown that Centipeda minima exhibited efficacy against certain cancers, however, to date, no studies have been conducted on its effects in breast cancer. Here, we aimed to investigate the anti-cancer activity of the total extract of Centipeda minima (CME), and its underlying mechanism, in TNBC. In MDA-MB-231, we found that CME could significantly reduce cell viability and proliferation, induce apoptosis and inhibit cancer cell migration and invasion, in a dose and time-dependent manner. We showed that CME may potentially act via inhibition of multiple signaling pathways, including the EGFR, PI3K/AKT/mTOR, NF-κB, and STAT3 pathways. Treatment with CME also led to in vitro downregulation of MMP-9 activity and inhibition of metastasis. Further, we demonstrated that CME could significantly reduce tumor burden in MDA-MB-231 xenograft mice, without any appreciable side effects. Based on our findings, CME is a promising candidate for development as a therapeutic with high efficacy against TNBC.

Sphingosine Kinase 1 Regulates the Survival of Breast Cancer Stem Cells and Non-stem Breast Cancer Cells by Suppression of STAT1

Cancer stem cells (CSCs) represent rare tumor cell populations capable of self-renewal, differentiation, and tumor initiation and are highly resistant to chemotherapy and radiotherapy. Thus, therapeutic approaches that can effectively target CSCs and tumor cells could be the key to efficient tumor treatment. In this study, we explored the function of SPHK1 in breast CSCs and non-CSCs. We showed that RNAi-mediated knockdown of SPHK1 inhibited cell proliferation and induced apoptosis in both breast CSCs and non-CSCs, while ectopic expression of SPHK1 enhanced breast CSC survival and mammosphere forming efficiency. We identified STAT1 and IFN signaling as key regulatory targets of SPHK1 and demonstrated that an important mechanism by which SPHK1 promotes cancer cell survival is through the suppression of STAT1. We further demonstrated that SPHK1 inhibitors, FTY720 and PF543, synergized with doxorubicin in targeting both breast CSCs and non-CSCs. In conclusion, we provide important evidence that SPHK1 is a key regulator of cell survival and proliferation in breast CSCs and non-CSCs and is an attractive target for the design of future therapies.

Basal-Type Breast Cancer Stem Cells Over-Express Chromosomal Passenger Complex Proteins

(1) Aim: In the present paper we analyzed the transcriptome of CSCs (Cancer Stem Cells), in order to find defining molecular processes of breast cancer. (2) Methods: We performed RNA-Seq from CSCs isolated from the basal cell line MDA-MB-468. Enriched processes and networks were studied using the IPA (Ingenuity Pathway Analysis) tool. Validation was performed with qRT-PCR and the analysis of relevant genes was evaluated by overexpression, flow cytometry and in vivo zebrafish studies. Finally, the clinical relevance of these results was assessed using reported cohorts. (3) Results: We found that CSCs presented marked differences from the non-CSCs, including enrichment in transduction cascades related to stemness, cellular growth, proliferation and apoptosis. Interestingly, CSCs overexpressed a module of co-regulated Chromosomal Passenger Proteins including BIRC5 (survivin), INCENP and AURKB. Overexpression of BIRC5 increased the number of CSCs, as assessed by in vitro and in vivo zebrafish xenotransplant analyses. Analysis of previously published cohorts showed that this co-regulated module was not only overexpressed in basal breast tumors but also associated with relapse-free and overall survival in these patients. (4) Conclusions: These results underline the importance of Cancer Stem Cells in breast cancer progression and point toward the possible use of chromosomal passenger proteins as prognostic factors.

MTSS1 suppresses mammary tumor-initiating cells by enhancing RBCK1-mediated p65 ubiquitination

Tumor-initiating cells (TICs) are considered the culprits of cancer development and progression. Dysregulation of metastasis suppressor protein 1 (MTSS1) has been widely observed in tumor metastasis, but its functional contribution and mechanism in cancer is poorly understood. Here we report a role of MTSS1 in suppressing TICs in breast cancer. Mtss1 knockout (KO) enhances the mammary epithelial TIC subpopulation in both luminal and basal-like breast cancer mouse models. MTSS1 also suppresses tumorsphere formation in breast cancer cells. Mechanistically, MTSS1 interacts with the E3 ligase RanBP2-type and C3HC4-type zinc finger containing 1 (RBCK1) to facilitate RBCK1-mediated p65 ubiquitination and degradation, thus suppressing the NF-κB signaling pathway and tumorigenesis. In addition, actin beta-like 2 (ACTBL2) competes with RBCK1 for MTSS1 binding, leading to p65 stabilization. Importantly, MTSS1 silencing promotes patient-derived organoid formation and xenograft growth. MTSS1 downregulation in clinical tumors is also linked to worse prognosis. Overall our data reveal a new paradigm of NF-κB regulation and may have important implications in therapeutics targeting TICs.

MicroRNA-708 activation by glucocorticoid receptor agonists regulate breast cancer tumorigenesis and metastasis via downregulation of NF-κB signaling

Therapeutic administration of glucocorticoids (GCs) is frequently used as add-on chemotherapy for palliative purposes during breast cancer treatment. Recent studies have shown that GC treatment induces microRNA-708 in ovarian cancer cells, resulting in impaired tumor cell proliferation and metastasis. However, the regulatory functions of GCs on miR-708 and its downstream target genes in human breast cancer cells (BCCs) are poorly understood. In this study, we found that treatment with either the synthetic GC dexamethasone (DEX) or the natural GC mimic, antcin A (ATA) significantly increased miR-708 expression by transactivation of glucocorticoid receptor alpha (GRα) in MCF-7 and MDA-MB-231 human BCCs. Induction of miR-708 by GR agonists resulted in inhibition of cell proliferation, cell-cycle progression, cancer stem cell (CSC)-like phenotype and metastasis of BCCs. In addition, GR agonist treatment or miR-708 mimic transfection remarkably inhibited IKKβ expression and suppressed nuclear factor-kappaB (NF-κB) activity and its downstream target genes, including COX-2, cMYC, cyclin D1, Matrix metalloproteinase (MMP)-2, MMP-9, CD24, CD44 and increased p21CIP1 and p27KIP1 that are known to be involved in proliferation, cell-cycle progression, metastasis and CSC marker protein. BCCs xenograft models indicate that treatment with GR agonists significantly reduced tumor growth, weight and volume. Overall, our data strongly suggest that GR agonists induced miR-708 and downstream suppression of NF-κB signaling, which may be applicable as a novel therapeutic intervention in breast cancer treatment.

Robust clustering of noisy high-dimensional gene expression data for patients subtyping

Motivation

One of the most important research areas in personalized medicine is the discovery of disease sub-types with relevance in clinical applications. This is usually accomplished by exploring gene expression data with unsupervised clustering methodologies. Then, with the advent of multiple omics technologies, data integration methodologies have been further developed to obtain better performances in patient separability. However, these methods do not guarantee the survival separability of the patients in different clusters.

Results

We propose a new methodology that first computes a robust and sparse correlation matrix of the genes, then decomposes it and projects the patient data onto the first m spectral components of the correlation matrix. After that, a robust and adaptive to noise clustering algorithm is applied. The clustering is set up to optimize the separation between survival curves estimated cluster-wise. The method is able to identify clusters that have different omics signatures and also statistically significant differences in survival time. The proposed methodology is tested on five cancer datasets downloaded from The Cancer Genome Atlas repository. The proposed method is compared with the Similarity Network Fusion (SNF) approach, and model based clustering based on Student's t-distribution (TMIX). Our method obtains a better performance in terms of survival separability, even if it uses a single gene expression view compared to the multi-view approach of the SNF method. Finally, a pathway based analysis is accomplished to highlight the biological processes that differentiate the obtained patient groups.

Availability and implementation

Our R source code is available online at https://github.com/angy89/RobustClusteringPatientSubtyping.

Supplementary information

Supplementary data are available at Bioinformatics online.

Pathological and molecular characteristics of inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer characterized by the presence of many dermal tumor emboli in the papillary and reticular dermis of the skin overlying the breast. IBC patients, compared to other breast cancer patients, have more frequently metastatic axillary lymph nodes. IBC is often high grade, negative for hormone receptors and presents with amplification of the HER2 gene. Invasive IBC is frequently of ductal phenotype, even if a specific histological distinction for these lesions has not been described. The pathogenesis and evolution of IBC are strongly dependent upon tumor microenvironment, characterized by several macrophages/monocytes and lymphocytes. The tumor and microenvironment cells are well molecularly characterized, showing the main contributor of inflammatory pathways in tumor biology of IBC. In addition, several molecular alterations are described in this tumor, such as mutations of ERBB2, KRAS, BRAF, EGFR, PIK3CA, PTEN, AKT1, and AKT3 genes that could suggest a therapeutic stratification of IBC patients with the combination of different biological target therapies.

NF-κB/NKILA signaling modulates the anti-cancerous effects of EZH2 inhibition

A wealth of evidence supports the broad therapeutic potential of NF-κB and EZH2 inhibitors as adjuvants for breast cancer treatment. We contribute to this knowledge by elucidating, for the first time, unique regulatory crosstalk between EZH2, NF-κB and the NF-κB interacting long non-coding RNA (NKILA). We define a novel signaling loop encompassing canonical and non-canonical actions of EZH2 on the regulation of NF-κB/NKILA homeostasis, with relevance to breast cancer treatment. We applied a respective silencing approach in non-transformed breast epithelial cells, triple negative MDA-MB-231 cells and hormone responsive MCF-7 cells, and measured changes in EZH2/NF-κB/NKILA levels to confirm their interdependence. We demonstrate cell line-specific fluctuations in these factors that functionally contribute to epithelial-to-mesenchymal transition (EMT) remodelling and cell fate response. EZH2 inhibition attenuates MDA-MB-231 cell motility and CDK4-mediated MCF-7 cell cycle regulation, while inducing global H3K27 methylation and an EMT phenotype in non-transformed cells. Notably, these events are mediated by a cell-context dependent gain or loss of NKILA and NF-κB. Depletion of NF-κB in non-transformed cells enhances their sensitivity to growth factor signaling and suggests a role for the host microenvironment milieu in regulating EZH2/NF-κB/NKILA homeostasis. Taken together, this knowledge critically informs the delivery and assessment of EZH2 inhibitors in breast cancer.

Tannic acid attenuates the formation of cancer stem cells by inhibiting NF-κB-mediated phenotype transition of breast cancer cells

Cancer stem cells (CSCs) are innately resistant to standard therapies, which positions CSCs in the focus of anti-cancer research. In this study, we investigated the potential inhibitory effect of tannic acid (TA) on CSCs. Our data demonstrated that TA (10 μM), at the concentration not inhibiting the proliferation of normal mammary cells (MCF10A), inhibited the formation and growth of mammosphere in MCF7, T47D, MDA-MB-231 cells shown as a decrease in mammosphere formation efficiency (MFE), cell number, diameter of mammosphere, and ALDH1 activity. NF-κB pathway was activated in the mammosphere indicated by an up-regulation of p65, a degradation of IκBα, and an increased IL-6. The inhibition of NF-κB pathway via gene silencing of p65 (sip65), NF-κB inhibitor (PDTC), or IKK inhibitor (Bay11-7082) alleviated MFE. Other CSCs markers such as an increase in ALDH1 and CD44^high/CD24^low ratio were ameliorated by sip65. TA also alleviated TGFβ-induced EMT, increase in MFE, and NF-κB activation. In murine xenograft model, TA reduced tumor volume which was associated with a decrease in CD44^high/CD24^low expression and IKK phosphorylation. These results suggest that TA negatively regulates CSCs by inhibiting NF-κB activation and thereby prevents cancer cells from undergoing EMT and CSCs formation, and may thus be a promising therapy targeting CSCs.

Melatonin is an appropriate candidate for breast cancer treatment: Based on known molecular mechanisms

Breast cancer is the most prevalent cancer and one of the most important causes of death in women throughout the world. Breast cancer risk factors include smoking, alcohol consumption, personal and family history, hypertension, and hormone therapy, long-term use of nonsteroidal anti-inflammatory drugs and tobacco usage. Surgery, chemotherapy, radiotherapy, immunotherapy, and neoadjuvant therapy are the current means for breast cancer treatment. Despite hormonal agents and chemotherapy, which have beneficial effects on lowering breast cancer death rate, the reaction of different people to these treatments is still a challenging point. Melatonin (N-acetyl-5-methoxy tryptamine) is a methoxy indole compound that is mainly secreted by the pineal gland at night; it is as an antioxidant, anti-inflammatory, and oncostatic agent. On the basis of recent studies, melatonin has antitumor properties on different cancer types and it may suppress cancer development in vitro and as well as in animal models. It is suggested that melatonin inhibits the development of breast cancer by various mechanisms. This paper summarizes the roles of melatonin in breast cancer treatment from the aspect of its molecular actions.

The role of inflammation and its related microRNAs in breast cancer: A narrative review

Breast cancer is recognized as the most common type of cancer among women with a high rate of mortality all over the world. Over the past years, growing attention has been regarded to realize more about the mechanisms underlying the disease process. It is revealed that the progression of breast cancer may be strongly linked to chronic inflammation owing to the role of inflammatory factors in genetic instability and subsequent cancer predisposition. Although the association between breast cancer and inflammatory pathways has been well-defined now, only recent evidence pointed towards the inflammation-related microRNAs (miRNAs) as potential biomarkers and therapeutic targets involved in the crosstalk of multiple pathways during breast cancer development. Moreover, the practical interactions between these miRNAs and inflammatory factors are also a little characterized. In this review, we intended to describe the effects of predominant inflammatory pathways such as cytokines, phosphoinositide 3-kinase/protein kinase B, and nuclear factor kappa B in association with tumor promoting and tumor suppressing miRNAs on breast cancer progression. Providing new studies in the field of combining biomarkers for early diagnosis, prognosis, and monitoring breast cancer are very important. Notably, understanding the underlying mechanisms of miRNAs as a possible link between inflammation and tumorigenesis may offer a novel insight for combating this epidemic.

Role of Hedgehog Signaling in Breast Cancer: Pathogenesis and Therapeutics

Breast cancer (BC) is the leading cause of cancer-related mortality in women, only followed by lung cancer. Given the importance of BC in public health, it is essential to identify biomarkers to predict prognosis, predetermine drug resistance and provide treatment guidelines that include personalized targeted therapies. The Hedgehog (Hh) signaling pathway plays an essential role in embryonic development, tissue regeneration, and stem cell renewal. Several lines of evidence endorse the important role of canonical and non-canonical Hh signaling in BC. In this comprehensive review we discuss the role of Hh signaling in breast development and homeostasis and its contribution to tumorigenesis and progression of different subtypes of BC. We also examine the efficacy of agents targeting different components of the Hh pathway both in preclinical models and in clinical trials. The contribution of the Hh pathway in BC tumorigenesis and progression, its prognostic role, and its value as a therapeutic target vary according to the molecular, clinical, and histopathological characteristics of the BC patients. The evidence presented here highlights the relevance of the Hh signaling in BC, and suggest that this pathway is key for BC progression and metastasis.

The Upregulation of hsa-mir-181b-1 and Downregulation of Its Target CYLD in the Late-Stage of Tumor Progression of Breast Cancer

Some microRNAs are usually dysregulated in the cancers and influencing tumor behavior and progression. Hsa-miR-181b-1 and its target CYLD are involved in regulating the inflammatory pathways. This study aimed to investigate the expression levels of hsa-mir-181b-1 and CYLD in a cohort of breast tumor tissues and normal adjacent tissues to assess their association with breast cancer stages. A total number of 60 breast samples including cancerous and normal adjacent tissue specimens were collected. After pathological study, the expression of hsa-mir-181b-1 and CYLD were measured by qRT-PCR method. The hsa-mir-181b-1 expression level was significantly increased in breast tumor tissues compared to the controls. This increase was associated with the disease progression. Conversely, CYLD expression level was decreased in tumor samples compared to normal samples, significantly. ROC curve data added other prestigious information of hsa-mir-181b-1 and CYLD by defining cancer and healthy tissues with high specificity and sensitivity at a proposed cutoff point. Also, bioinformatic enrichment for the possible targets of mature sequence of "hsa-mir-181b-5p" was performed. Computational analysis showed the five most significant pathways including metabolic, cancer, calcium signaling, PI3K-Akt signaling and focal adhesion pathways which may be influenced by hsa-mir-181b-1. Thus, we suggested hsa-mir-181b-1 and CYLD might be involved in the pathogenesis of breast cancer and could be considered as two biomarkers for prediction, prognosis and diagnosis of the stages of the breast cancer.

Therapeutics strategies against cancer stem cell in breast cancer

Breast cancer is known as a most prevalent cancer and second deadly cancer, among women worldwide. Due to the high incidence rate of breast cancer and limitations of conventional therapy it seemed essential to look for new targets in cancer cells and directly target them such as target therapy on breast cancer stem cells. In this review we indicate some of therapeutic uses of cancer stem cells in breast cancer. Some strategies are targeting surface specific markers and activated signaling pathways in their microenvironment such as Notch, Hedgehog, Wnt/b-catenin, PI3K/Akt, NF-kB, BMP and TGF-β and their maintenance and drug resistance, using various miRNAs, enhancement of CSCs apoptosis, differentiation therapy, blocking epithelial to mesenchymal transition and using different natural compounds. Recent studies have shown that cancer stem cells play major roles in target therapy on breast cancer. The new manipulation approaches of cancer stem cells can be used as target therapy of breast cancer that were highlighted for immunotherapy of cancer.

Dimethyl fumarate, a two-edged drug: Current status and future directions

Dimethyl fumarate (DMF) is a fumaric acid ester registered for the treatment of relapsing-remitting multiple sclerosis (RRMS). It induces protein succination leading to inactivation of cysteine-rich proteins. It was first shown to possess cytoprotective and antioxidant effects in noncancer models, which appeared related to the induction of the nuclear factor erythroid 2 (NF-E2)-related factor 2 (NRF2) pathway. DMF also displays antitumor activity in several cellular and mice models. Recently, we showed that the anticancer mechanism of DMF is dose-dependent and is paradoxically related to the decrease in the nuclear translocation of NRF2. Some other studies performed indicate also the potential role of DMF in cancers, which are dependent on the NRF2 antioxidant and cellular detoxification program, such as KRAS-mutated lung adenocarcinoma. It, however, seems that DMF has multiple biological effects as it has been shown to also inhibit the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), thus blocking downstream targets that may be involved in the development and progression of inflammatory cascades leading to various disease processes, including tumors, lymphomas, diabetic retinopathy, arthritis, and psoriasis. Herein, we present the current status and future directions of the use of DMF in various diseases models with particular emphases on its targeting of specific intracellular signal transduction cascades in cancer; to shed some light on its possible mode of action.

Exosomes from differentially activated macrophages influence dormancy or resurgence of breast cancer cells within bone marrow stroma

Breast cancer (BC) cells (BCCs) can retain cellular quiescence for decades, a phenomenon referred to as dormancy. BCCs show preference for the bone marrow (BM) where they can remain dormant for decades. Targeting BCCs within the BM is a challenge since the dormant BCCs reside within BM stroma, also residence for hematopoietic stem cells (HSCs). Dormant BCCs could behave as cancer stem cells (CSCs). The CSCs and HSCs are similar by function and also, by commonly expressed genes. The method by which dormant BCCs transition into clinically metastatic cells remains unclear. This study tested the hypothesis that macrophages (MΦs) within BM stroma, facilitates dormancy or reverse this state into metastatic cells. MΦs exhibiting an M2 phenotype constitute ~10% of cultured BM stroma. The M2 MΦs form gap junctional intercellular communication (GJIC) with CSCs, resulting in cycling quiescence, reduced proliferation and carboplatin resistance. In contrast, MΦs expressing the M1 phenotype reversed BC dormancy. Activation of M2a MΦs via the toll-like receptor 4 (TLR4) switched to M1 phenotype. The switch can occur by direct activation of M2a MΦs, or indirectly through activation of mesenchymal stem cells. M1 MΦ-derived exosomes activated NFкB to reverse quiescent BCCs to cycling cells. Using an in vivo model of BC dormancy, injected Mi MOs sensitized BCCs to carboplatin and increased host survival. In summary, we have shown how BM stromal MΦs, through exosomes, regulate the behavior of BCCs, by either inducing or reversing dormancy.

Resistance to endocrine therapy in breast cancer: molecular mechanisms and future goals

Introduction

The majority of breast cancers (BCs) are characterized by the expression of estrogen receptor alpha (ERα+). ERα acts as ligand-dependent transcription factor for genes associated with cell survival, proliferation, and tumor growth. Thus, blocking the estrogen agonist effect on ERα is the main strategy in the treatment of ERα+ BCs. However, despite the development of targeted anti-estrogen therapies for ER+ BC, around 30–50% of early breast cancer patients will relapse. Acquired resistance to endocrine therapy is a great challenge in ER+ BC patient treatment.

Discussion

Anti-estrogen resistance is a consequence of molecular changes, which allow for tumor growth irrespective of estrogen presence. Those changes may be associated with ERα modifications either at the genetic, regulatory or protein level. Additionally, the activation of alternate growth pathways and/or cell survival mechanisms can lead to estrogen-independence and endocrine resistance.

Conclusion

This comprehensive review summarizes molecular mechanisms associated with resistance to anti-estrogen therapy, focusing on genetic alterations, stress responses, cell survival mechanisms, and cell reprogramming.