Triple negative breast cancer

Medicinal Mushrooms in Metastatic Breast Cancer: What Is Their Therapeutic Potential as Adjuvant in Clinical Settings?

Breast cancer (BC) is the most commonly diagnosed tumor, remaining one of the leading causes of morbidity and mortality in females worldwide, with the highest rates in Western countries. Among metastatic BC (MBC), triple-negative breast cancer (TNBC) is characterized by the lack of expression of specific receptors, and differs from other subgroups of BC for its increased growth and fast spreading, with reduced treatment possibilities and a worse outcome. Actually, MBC patients are extremely prone to metastasis and consequent relapses, which affect distant target organs (e.g., brain, lung, bone and liver). Hence, the comprehension of biological mechanisms underlying the BC metastatization process is a key requirement to conceive/set up innovative medicinal strategies, with the goal to achieve long-lasting therapeutic efficacy, reducing adverse effects, and also ameliorating Quality of Life (QoL). Bioactive metabolites isolated from medicinal mushrooms (MMs) used as a supportive treatment, combined with conventional oncology, have recently gained wide interest. In fact, mounting evidence has revealed their peculiar promising immunomodulatory, anti-inflammatory and anticancer activities, even though these effects have to be further clarified. Among the group of most promising MMs are Lentinula edodes, Grifola frondosa, Ganoderma lucidum, Ophiocordyceps sinensis and Agaricus blazei, which are already employed in conventional cancer protocols in Asia and China. Recently, a growing number of studies have focused on the pharmacology and feasibility of MM-derived bioactive compounds as a novel valuable approach to propose an effective adjuvant therapy for MBC patients' management. In this review, we summarized the current state of knowledge on the abovementioned MM-derived bioactive compounds and their therapeutic potential in clinical settings.

An insight into the therapeutic effects of isoliquiritigenin in breast cancer

Breast cancer ranks as the most widespread malignant condition in women, emerging as a primary contributor to mortality. The primary challenges in cancer treatments involve undesirable side effects. Therefore, exploring natural compounds as additional therapy could provide valuable insights. Isoliquiritigenin (ILN), an isoflavonoid featuring a chalcone moiety primarily sourced from Glycyrrhiza species, has garnered increasing interest in breast cancer research. This review aims to provide a comprehensive understanding of ILN's mechanisms of action in breast cancer, drawing from a range of in vitro and in vivo studies. ILN primarily acts by inhibiting angiogenesis, aromatase, inflammation, and cell proliferation, and preventing invasion and metastasis. Mechanistically, it downregulates miR-374a, phosphoinositide-3-kinase-protein kinase B/Akt, maternal embryonic leucine zipper kinase, vascular endothelial growth factor, and estrogen receptor protein levels, and causes enhancement of Wnt inhibitory factor-1, and Unc-51-like kinase 1 expression to treat breast cancer. ILN emerges as a promising natural option, offering therapeutic advantages with minimal side effects. However, it is important to note that current research on ILN is primarily limited to preclinical models, underscoring the need for further investigation to validate its potential efficacy.

Targeting Pivotal Hallmarks of Cancer for Enhanced Therapeutic Strategies in Triple-Negative Breast Cancer Treatment-In Vitro, In Vivo and Clinical Trials Literature Review

This literature review provides a comprehensive overview of triple-negative breast cancer (TNBC) and explores innovative targeted therapies focused on specific hallmarks of cancer cells, aiming to revolutionize breast cancer treatment. TNBC, characterized by its lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), presents distinct features, categorizing these invasive breast tumors into various phenotypes delineated by key elements in molecular assays. This article delves into the latest advancements in therapeutic strategies targeting components of the tumor microenvironment and pivotal hallmarks of cancer: deregulating cellular metabolism and the Warburg effect, acidosis and hypoxia, the ability to metastasize and evade the immune system, aiming to enhance treatment efficacy while mitigating systemic toxicity. Insights from in vitro and in vivo studies and clinical trials underscore the promising effectiveness and elucidate the mechanisms of action of these novel therapeutic interventions for TNBC, particularly in cases refractory to conventional treatments. The integration of targeted therapies tailored to the molecular characteristics of TNBC holds significant potential for optimizing clinical outcomes and addressing the pressing need for more effective treatment options for this aggressive subtype of breast cancer.

Identification of INFG/STAT1/NOTCH3 as γ-Mangostin's potential targets for overcoming doxorubicin resistance and reducing cancer-associated fibroblasts in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a very aggressive subtype of breast cancer characterized by drug resistance and distant metastasis. Cancer stem cells (CSCs) are considered a major contributor to TNBC's drug resistance. Thus targeting and eliminating CSCs have been vigorously researched. However, the precise targetable molecular networks responsible for CSC genesis remain unclear; this conundrum is mainly due to the high heterogeneity of the TNBC tumor microenvironment (TME). The cancer-associated fibroblasts (CAFs) are one of the most abundant cellular components of the TME. Emerging studies indicate that CAFs facilitate TNBC's progression by establishing a pro-tumor TME. Hence, identifying the molecular networks involved in CAF transformation and CAF-associated oncogenesis are essential areas to be explored. Through a bioinformatics approach, we identified INFG/STAT1/NOTCH3 as a molecular link between CSCs and CAF. DOX-resistant TNBC cell lines showed increased expression of INFG/STAT1/NOTCH3 and CD44 and were associated with increased self-renewal ability and CAF-transformative ability. Downregulation of STAT1 significantly reduced the tumorigenic properties of MDA-MB-231 and -468 cells and their CAF-transforming potential. Our molecular docking analysis suggested that gamma mangostin (gMG), a xanthone, formed complexes with INFG/STAT1/NOTCH3 better than celecoxib. We then demonstrated that gMG treatment reduced the tumorigenic properties similarly observed in STAT1-knocked down conditions. Finally, we utilized a DOX-resistant TNBC tumoroid-bearing mouse model to demonstrate that gMG treatment significantly delayed tumor growth, reduced CAF generation, and improved DOX sensitivity. Further investigations are warranted for clinical translation.

Fighting secondary triple-negative breast cancer in cerebellum: A powerful aid from a medicinal mushrooms blend

Breast cancer (BC) is the second most common cause of brain metastasis onset in patients, with the cerebellum accounting for the 33% of cases. In the current study, using a 4T1 triple-negative mouse BC model, we revealed that an orally administered medicinal mushrooms (MM) blend, rich in β-glucans, played a direct and specific anti-cancer action on cerebellar metastases, also bettering locomotor performances. The neuroprotective effect of the MM blend plays through (i) a direct and specific inhibition of cerebellar metastatization pattern typical of TNBC (with an induced reduction of about 50% of metastases density) and (ii) the regulation of apoptosis and proliferation-related genes, as suggested by expression changes of specific molecular markers, i.e. PCNA, p53, Bcl2, BAX, CASP9, CASP3, Hsp70 and AIF. Therefore, inhibiting the metastatization process, triggering a significant apoptosis increase, and lessening cell proliferation, this MM supplement, employed as adjuvant treatment in association with conventional therapy, could represent a promising approach, in the field of Integrative Oncology, for patients' management in both prevention and treatment of brain metastases from BC.

Epigenetic restoration and activation of ERβ: an inspiring approach for treatment of triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer. TNBC lacks targeted therapy receptors, rendering endocrine and HER2-targeted therapies ineffective. TNBC is typically treated with cytotoxic chemotherapy followed by surgery. Targeting epigenetic modifications could potentially be a new effective TNBC target therapy. The aim of this study is to examine the effects of epigenetic drugs, decitabine as DNA methyltransferase inhibitor (DNMTI) and vorinostat as histone deacetylase inhibitor (HDACI), and the ERβ agonist DPN on ERα and ERβ re-expressions in the MDA-MB-231 cells as a model of TNBC.

METHODS

Using MTT assay, the IC50 of decitabine, vorinostat, and DPN on MDA-MB-231 cells were determined. The effects of all drugs alone or in combinations on MDA-MB-231 cells were evaluated. qRT-PCR was used to determine ERα & ERβ gene expression. Caspase-3 activity and the protein expression levels of VEGF, Cyclin D1, and IGF-1 were assessed.

RESULTS

Both ERα and ERβ mRNA were re-expressed in different high levels in all treated groups, especially in the triple therapy group compared with control. Significantly, the triple drugs therapy showed the lowest levels of VEGF, Cyclin D1, and IGF-1 and the highest level of Caspase-3 activity, indicating a possible antitumor effect of ERβ activation through decreasing proliferation and angiogenesis and increasing apoptosis in MDA-MB-231 cells.

CONCLUSIONS

The antiproliferative effect of ERβ could be retained when co-expressed with Erα using a powerful epigenetic combination of Decitabine and vorinostat with DPN.

Signaling Pathways and Natural Compounds in Triple-Negative Breast Cancer Cell Line

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, having a poor prognosis and rapid metastases. TNBC is characterized by the absence of estrogen, progesterone, and human epidermal growth receptor-2 (HER2) expressions and has a five-year survival rate. Compared to other breast cancer subtypes, TNBC patients only respond to conventional chemotherapies, and even then, with limited success. Shortages of chemotherapeutic medication can lead to resistance, pressured index therapy, non-selectivity, and severe adverse effects. Finding targeted treatments for TNBC is difficult owing to the various features of cancer. Hence, identifying the most effective molecular targets in TNBC pathogenesis is essential for predicting response to targeted therapies and preventing TNBC cell metastases. Nowadays, natural compounds have gained attention as TNBC treatments, and have offered new strategies for solving drug resistance. Here, we report a systematic review using the database from Pubmed, Science Direct, MDPI, BioScince, Springer, and Nature for articles screening from 2003 to 2022. This review analyzes relevant signaling pathways and the prospect of utilizing natural compounds as a therapeutic agent to improve TNBC treatments in the future.

Clinicopathological Features of BRCA1/2 Mutation-Positive Breast Cancer

PURPOSE

The BRCA1/2 gene is the most well-known and studied gene associated with hereditary breast cancer. BRCA1/2 genetic testing is widely performed in high-risk patients of hereditary breast cancer in Korea. This study aimed to investigate the clinicopathological characteristics of BRCA1/2 mutation-positive breast cancer patients.

METHODS

The clinical data of 188 Korean breast cancer patients who underwent genetic testing of BRCA1/2 mutation between March 2015 and February 2020 at Pusan National University Yangsan Hospital were retrospectively reviewed. The characteristics of breast cancer according to the expression of BRCA1 and BRCA2 mutations were analyzed using the Health Insurance Review and Assessment Service guideline criteria and other clinicopathological factors.

RESULTS

The factor associated with BRCA1/2 gene expression was cancer stage, and mutation expression was significantly decreased in stage I compared to stage 0 (p = 0.033; odds ratio [OR], 0.169; 95% confidence interval [CI], 0.033-0.867), and there was a tendency to increase in stage II (p = 0.780; OR, 1.150; 95% CI, 0.432-3.064). BRCA1 was significantly associated with triple-negative breast cancer (TNBC) (p = 0.004; OR, 5.887; 95% CI, 1.778-19.498). Gene expression of BRCA2 was significantly reduced under 40 years of age (p = 0.040; OR, 0.198; 95% CI, 0.042-0.930). There was no difference in disease-free survival (p = 0.900) and overall survival (p = 0.733) between the BRCA1/2 mutation-positive and -negative groups.

CONCLUSION

In this study, the clinicopathological characteristics of breast cancer patients with BRCA1/2 gene mutations were identified. BRCA1 gene expression was highly correlated with TNBC. BRCA1/2 mutation did not have a poor prognosis regarding recurrence and death.

Concordance of Programmed Death-Ligand 1 Expression between SP142 and 22C3/SP263 Assays in Triple-Negative Breast Cancer

PURPOSE

Triple-negative breast cancer (TNBC) represents a major clinical challenge due to its aggressive and metastatic behavior and the lack of available targeted therapies. Therefore, therapeutic strategies are needed to improve TNBC patient management. Recently, atezolizumab and nab-paclitaxel chemotherapy has been approved by the Food and Drug Administration for the first-line treatment of patients with locally advanced and metastatic TNBC. The programmed death-ligand 1 (PD-L1) immunohistochemical SP142 assay was also approved as a companion diagnostic device for selecting TNBC patients for atezolizumab treatment. This study aimed to evaluate and compare the analytical performance of the PD-L1 22C3/SP263 assays in comparison with the SP142 assay for ≥ 1% immune cells (ICs).

METHODS

Immunohistochemical expression for the PD-L1 22C3/SP263 assays, in comparison with the SP142 assay, was analyzed for the ≥ 1% ICs in 95 TNBCs.

RESULTS

At the 1% cut-off value, the proportions of positive cases were 52.6% for the SP142 assay in infiltrating ICs and 50.5% and 52.6% for the 22C3 and SP263 assays in tumor cells, respectively. The PD-L1 SP263 assay had the highest while the PD-L1 22C3 assay had the lowest total positive expression rate at all cut-off values. The concordance rate between the assays was highest at a 1% cut-off value and decreased when the cut-off value increased. The concordance rate between the SP142 and SP263 assays at 1% cut-off was high, while in comparison, the concordance rate between the SP142 and 22C3 assays at 1% cut-off was relatively lower.

CONCLUSION

This study demonstrates that although the 22C3 assay at a 1% cut-off value compared with the PD-L1 SP142 assay at the clinically relevant cut-off shows comparable but not interchangeable analytical performance, the analytical performance of the SP263 assay at a 1% cut-off value shows interchangeable performance with the PD-L1 SP142 assay at the clinically relevant cut-off.

Overexpression of MiR-146a-5p Upregulates lncRNA HOTAIR in Triple-Negative Breast Cancer Cells and Predicts Poor Prognosis

MiR-146a-5p plays different roles in different types of cancers. We showed that miR-146a-5p and long noncoding RNA HOTAIR were both upregulated in triple-negative breast cancer. Follow-up study showed that high levels of miR-146a-5p and HOTAIR in tumor tissues were closely correlated with poor survival. MiR-146a-5p and HOTAIR were positively correlated in tumor tissues. MiR-146a-5p positively regulated HOTAIR triple-negative breast cancer cells, while HOTAIR showed no regulatory effects on miR-146a-5p expression. MiR-146a-5p and HOTAIR positively regulated the migration and invasion of triple-negative breast cancer cells. In addition, HOTAIR silencing attenuated the effects of miR-146a-5p. Therefore, overexpression of miR-146a-5p may promote triple-negative breast cancer cell invasion and migration by upregulating HOTAIR.

Anti-Migratory and Pro-Apoptotic Properties of Parvifloron D on Triple-Negative Breast Cancer Cells

Medicinal plants are important sources of new bioactive compounds with potential anticancer activity. Parvifloron D (ParvD) is an abietane diterpenoid, isolated in high amounts from Plectranthus ecklonii Benth. Previous reports have suggested potential therapeutic properties for ParvD. ParvD has shown pro-apoptotic and cytotoxic effects in leukemia and melanoma cell lines. However, to the best of our knowledge, there are no studies in triple-negative breast cancer (TNBC) models. TNBC is a breast cancer subtype characterized by an aggressive behavior with poor clinical outcomes and weak overall therapeutic responses to the current treatment options. This work aimed at evaluating the anticancer effect of ParvD in MDA-MB-231 cells, a model of human TNBC. To obtain sufficient amounts of purified ParvD the efficiency of several extraction methods was compared. ParvD (0.1–10 µM) decreased cell viability in a concentration-dependent manner. Treatment with ParvD (5 µM) significantly increased the percentage of apoptotic nuclei and exposure to 3 µM ParvD increased the sub-G1 population. Since altered cell adherence, migration, and invasion are determinant processes for the formation of metastases, the effect of ParvD on these cellular processes was tested. Although treatment with ParvD (1 µM) had no effect on cell-substrate attachment, ParvD (1 µM) significantly reduced cell chemotaxis and invasion. This is the first report describing the proapoptotic effect of ParvD in TNBC cells. Moreover, for the first time we have shown that ParvD reduces cell motility, unraveling potential anti-metastatic properties.

Paclitaxel's Mechanistic and Clinical Effects on Breast Cancer

Paclitaxel (PTX), the most widely used anticancer drug, is applied for the treatment of various types of malignant diseases. Mechanisms of PTX action represent several ways in which PTX affects cellular processes resulting in programmed cell death. PTX is frequently used as the first-line treatment drug in breast cancer (BC). Unfortunately, the resistance of BC to PTX treatment is a great obstacle in clinical applications and one of the major causes of death associated with treatment failure. Factors contributing to PTX resistance, such as ABC transporters, microRNAs (miRNAs), or mutations in certain genes, along with side effects of PTX including peripheral neuropathy or hypersensitivity associated with the vehicle used to overcome its poor solubility, are responsible for intensive research concerning the use of PTX in preclinical and clinical studies. Novelties such as albumin-bound PTX (nab-PTX) demonstrate a progressive approach leading to higher efficiency and decreased risk of side effects after drug administration. Moreover, PTX nanoparticles for targeted treatment of BC promise a stable and efficient therapeutic intervention. Here, we summarize current research focused on PTX, its evaluations in preclinical research and application clinical practice as well as the perspective of the drug for future implication in BC therapy.

MiR-214-3p regulates the viability, invasion, migration and EMT of TNBC cells by targeting ST6GAL1

MiR-214-3p is concerned with the outcomes of various tumors, such as liver cancer, bladder cancer, etc. However, the role and target of miR-214-3p in triple negative breast cancer (TNBC) is not fully understood. This study took this as the entry point, with a view to find a potential target for TNBC. The expressions of miR-214-3p in TNBC tissues and cell lines were detected, and the effects of miR-214-3p inhibitor on the viability, migration, invasion and epithelial mesenchymal transition (EMT) of TNBC cells were further analyzed. The potential target of miR-214-3p were predicted and verified, as well as the effects of target silencing on the TNBC cells were also measured. MiR-214-3p was abnormally elevated in both TNBC tissues and cell lines, especially in MDA-MB-468 cells. Low-expression of miR-214-3p restrained the survival, migration, invasion and EMT of TNBC cells. ST6GAL1 was the target gene of miR-214-3p, and its expression level increased with the low-expression of miR-214-3p. ST6GAL1 expression was abnormally reduced in both TNBC tissues and cell lines. The silence of ST6GAL1 promoted the viability, migration, invasion and EMT of TNBC cells, which could be reversed by miR-214-3p inhibitor. The down-regulation of miR-214-3p could suppress the viability, migration, invasion and EMT of TNBC cells though targeting ST6GAL1, which might be a potential target for future treatment of TNBC. Up-regulation of miR-214-3p could promote the EMT of non-TNBC cells.

Inhibition of miRNA-34a promotes triple negative cancer cell proliferation by promoting glucose uptake

miRNA-34a is a tumor suppressor that is expressed in a variety of different types of cancer. The current study aimed to determine the involvement of miRNA-34a in triple negative breast cancer. miRNA-34a expression was detected using reverse transcription-quantitative PCR in the breast tissue and serum of patients with triple negative breast cancer and of healthy controls. The diagnostic value of miRNA-34a in triple negative breast cancer was analyzed using receiver operating curve analysis. A miRNA-34a inhibitor was transfected into triple negative breast cancer cells and the effects on cell proliferation, glucose uptake and glucose transporter 1 (GLUT1) expression were detected using a cell counting kit-8 assay, glucose uptake assay and western blot analysis, respectively. The results demonstrated that miRNA-34a was downregulated in patients with triple negative breast cancer compared with healthy controls and the downregulation of miRNA-34a effectively distinguished patients with triple negative breast cancer from healthy controls. miRNA-34a inhibition promoted cancer cell proliferation, accelerated glucose uptake and upregulated GLUT1. The current study concluded that the inhibition of miR-34a may promote triple negative cancer cell proliferation by promoting glucose uptake.

Druggable Molecular Targets for the Treatment of Triple Negative Breast Cancer

Breast cancer (BC) is still the most common cancer among women worldwide. Amongst the subtypes of BC, triple negative breast cancer (TNBC) is characterized by deficient expression of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. These patients are therefore not given the option of targeted therapy and have worse prognosis as a result. Consequently, much research has been devoted to identifying specific molecular targets that can be utilized for targeted cancer therapy, thereby limiting the progression and metastasis of this invasive tumor, and improving patient outcomes. In this review, we have focused on the molecular targets in TNBC, categorizing these into targets within the immune system such as immune checkpoint modulators, intra-nuclear targets, intracellular targets, and cell surface targets. The aim of this review is to introduce and summarize the known targets and drugs under investigation in phase II or III clinical trials, while introducing additional possible targets for future drug development. This review brings a tangible benefit to cancer researchers who seek a comprehensive comparison of TNBC treatment options.

Ilamycin E, a natural product of marine actinomycete, inhibits triple-negative breast cancer partially through ER stress-CHOP-Bcl-2

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among women in the worldwide. Triple-negative breast cancer (TNBC) has a poor clinical outcome. The antitumor efficacy of Ilamycins, natural products with anti-tuberculosis activity isolated from deep sea-derived Streptomyces atratus, in TNBC has not been investigated, and the mechanisms remain elusive. Here, we demonstrated that Ilamycin-E, but not -F, decreases cell viability, inhibits G1/S cell cycle progression, and promotes apoptosis in the TNBC cell lines HCC1937 and MDA-MB-468. Ilamycin E promotes apoptosis via activation of endoplasmic reticulum (ER) stress, increasing the expression of CHOP, and down-regulating the expression of anti-apoptotic protein Bcl-2. Depletion of CHOP or overexpression of Bcl2 significantly rescued Ilamycin E-induced apoptosis. These findings indicate that Ilamycin E has anti-cancer activity in TNBC.

LncRNA AWPPH and miRNA-21 regulates cancer cell proliferation and chemosensitivity in triple-negative breast cancer by interacting with each other

Long-non-coding RNAs (lncRNA) AWPPH promotes the progression of liver and bladder cancer, indicating its oncogenic role. The current study aimed to explore the involvement of AWPPH in triple-negative breast cancer (TNBC). In the current study, we found that plasma levels of lncRNA AWPPH and microRNA-21 (miRNA-21) were upregulated in patients with TNBC than in healthy controls, and the upregulation of plasma lncRNA AWPPH and miRNA-21 distinguished early-stage patients with TNBC from healthy controls. Plasma levels of lncRNA AWPPH and miRNA-21 were significantly and positively correlated in both patients with TNBC and healthy controls. LncRNA AWPPH and miRNA-21 overexpression led to promoted cancer cells proliferation and improved cancer cell viability under carboplatin treatment, while lncRNA AWPPH small interfering RNA (siRNA) silencing played an opposite role. In addition, miRNA-21 overexpression attenuated the effects of lncRNA AWPPH siRNA silencing on of cancer cell behaviors. LncRNA AWPPH overexpression led to upregulated miRNA-21 in TNBC cells, while miRNA-21 overexpression also led to significantly upregulated lncRNA AWPPH expression. Therefore, lncRNA AWPPH and miRNA-21 may regulate cancer cell proliferation and chemosensitivity in TNBC by interacting with each other.

LncRNA NEF is downregulated in triple negative breast cancer and correlated with poor prognosis

LncRNA NEF has been proved to be a tumor suppressor in liver cancer. In the present study, we found that lncRNA NEF was downregulated and miRNA-155 was upregulated in plasma of triple-negative breast cancer (TNBC) patients compared with those in controls. These two factors were inversely correlated only in TNBC patients but not in controls. Altered expression of lncRNA NEF and miRNA-155 distinguished TNBC patients from healthy controls. Follow-up study showed that low level of lncRNA NEF and high level of miRNA-155 were correlated with poor survival. LncRNA NEF overexpression inhibited the migration and invasion of TNBC cells, while miRNA-155 overexpression promoted the migration and invasion of TNBC cells, but showed no significant effects on cancer cell proliferation. MiRNA-155 overexpression partially rescued the inhibited cell migration and invasion caused by lncRNA NEF overexpression. LncRNA NEF overexpression inhibited miRNA-155 expression, while miRNA-155 overexpression showed no significant effect on lncRNA NEF expression. Therefore, lncRNA NEF may participate in TNBC by negatively regulating miRNA-155.

LncRNA POU3F3 promotes proliferation and inhibits apoptosis of cancer cells in triple-negative breast cancer by inactivating caspase 9

It has been reported that lncRNA POU3F3 was upregulated in esophageal squamous-cell carcinomas, indicating its role as an oncogene in this disease. However, the mechanism of its function and its involvement in other malignancies is unknown. In the present study we found that expression levels of lncRNA POU3F3 were higher in tumor tissues than in adjacent healthy tissues of triple negative breast cancer (TNBC) patients and were significantly and inversely correlated with levels of cleaved caspase 9 only in tumor tissues. In addition, plasma levels of lncRNA POU3F3 were higher in TNBC patients than in healthy controls and were significantly and inversely correlated with levels of cleaved caspase 9 only in TNBC patients. In addition, treatment of exogenous Cleaved Caspase-9 significantly attenuated the effects of lncRNA POU3F3 overexpression on cancer cell proliferation and apoptosis. lncRNA POU3F3 may promote proliferation and inhibit apoptosis of cancer cells in triple-negative breast cancer.

Probing the interaction between the histone methyltransferase/deacetylase subunit RBBP4/7 and the transcription factor BCL11A in epigenetic complexes

The transcription factor BCL11A has recently been reported to be a driving force in triple-negative breast cancer (TNBC), contributing to the maintenance of a chemoresistant breast cancer stem cell (BCSC) population. Although BCL11A was shown to suppress γ-globin and p21 and to induce MDM2 expression in the hematopoietic system, its downstream targets in TNBC are still unclear. For its role in transcriptional repression, BCL11A was found to interact with several corepressor complexes; however, the mechanisms underlying these interactions remain unknown. Here, we reveal that BCL11A interacts with histone methyltransferase (PRC2) and histone deacetylase (NuRD and SIN3A) complexes through their common subunit, RBBP4/7. In fluorescence polarization assays, we show that BCL11A competes with histone H3 for binding to the negatively charged top face of RBBP4. To define that interaction, we solved the crystal structure of RBBP4 in complex with an N-terminal peptide of BCL11A (residues 2-16, BCL11A(2-16)). The crystal structure identifies novel interactions between BCL11A and the side of the β-propeller of RBBP4 that are not seen with histone H3. We next show that BCL11A(2-16) pulls down RBBP4, RBBP7, and other components of PRC2, NuRD, and SIN3A from the cell lysate of the TNBC cell line SUM149. Furthermore, we demonstrate the therapeutic potential of targeting the RBBP4-BCL11A binding by showing that a BCL11A peptide can decrease aldehyde dehydrogenase-positive BCSCs and mammosphere formation capacity in SUM149. Together, our findings have uncovered a previously unidentified mechanism that BCL11A may use to recruit epigenetic complexes to regulate transcription and promote tumorigenesis.

High-level expression of ARID1A predicts a favourable outcome in triple-negative breast cancer patients receiving paclitaxel-based chemotherapy

Paclitaxel‐based chemotherapy is a common strategy to treat patients with triple‐negative breast cancer (TNBC). As paclitaxel resistance is still a clinical issue in treating TNBCs, identifying molecular markers for predicting pathologic responses to paclitaxel treatment is thus urgently needed. Here, we report that an AT‐rich interaction domain 1A (ARID1A) transcript is up‐regulated in paclitaxel‐sensitive TNBC cells but down‐regulated in paclitaxel‐resistant cells upon paclitaxel treatment. Moreover, ARID1A expression was negatively correlated with the IC₅₀ concentration of paclitaxel in the tested TNBC cell lines. Kaplan‐Meier analyses revealed that ARID1A down‐regulation was related to a poorer response to paclitaxel‐based chemotherapy in patients with TNBCs as measured by the recurrence‐free survival probability. The pharmaceutical inhibition with p38MAPK‐specific inhibitor SCIO‐469 revealed that p38MAPK‐related signalling axis regulates ARID1A expression and thereby modulates paclitaxel sensitivity in TNBC cells. These findings suggest that ARID1A could be used as a prognostic factor to estimate the pathological complete response for TNBC patients who decide to receive paclitaxel‐based chemotherapy.

Efficacy and Safety of Vinorelbine Plus Cisplatin vs. Gemcitabine Plus Cisplatin for Treatment of Metastatic Triple-Negative Breast Cancer After Failure with Anthracyclines and Taxanes

BACKGROUND This study aimed to compare the efficacy and safety of vinorelbine plus cisplatin (NP regimen) vs. gemcitabine plus cisplatin (GP regimen) for treatment of metastatic TNBC after failure with anthracyclines and taxanes. MATERIAL AND METHODS A total of 48 patients with metastatic TNBC that failed in anthracyclines and taxanes treatment were enrolled and randomly grouped. Patients in the NP group (n=22) were given 25 mg/m² vinorelbine on days 1 and 8 and 25 mg/m² cisplatin on days 2-4 of each 21-day cycle, while subjects in the GP group (n=26) were administered 1000 mg/m² gemcitabine on days 1 and 8 and 25 mg/m² cisplatin on days 2-4 of each 21-day cycle. The treatment response and adverse events were compared between the 2 groups every 2 cycles. RESULTS The ORR, DCR, and median TTP were 45.5%, 77.3%, and 5 months in the NP group, and 46.2%, 80.8%, and 5.2 months in the GP group, and no significant differences were observed in ORR, DCR, and median TTP between the 2 groups (P>0.05). The major adverse events included grade I-II bone marrow inhibition, gastrointestinal reactions, and phlebitis, and a lower incidence of thrombocytopenia and rash and a higher incidence of phlebitis was found in the NP group than in the GP group (P<0.05). CONCLUSIONS Either NP or GP regimen is active and tolerated in treatment of metastatic TNBC with anthracyclines and/or taxanes resistance, which may be used as a salvage treatment for metastatic TNBC.

Targeted exome sequencing of Korean triple-negative breast cancer reveals homozygous deletions associated with poor prognosis of adjuvant chemotherapy-treated patients

Triple-negative breast cancer is characterized by the absence of estrogen and progesterone receptors and human epidermal growth factor receptor 2, and is associated with a poorer outcome than other subtypes of breast cancer. Moreover, there are no accurate prognostic genes or effective therapeutic targets, thereby necessitating continued intensive investigation. This study analyzed the genetic mutation landscape in 70 patients with triple-negative breast cancer by targeted exome sequencing of tumor and matched normal samples. Sequencing showed that more than 50% of these patients had deleterious mutations and homozygous deletions of DNA repair genes, such as ATM, BRCA1, BRCA2, WRN, and CHEK2. These findings suggested that a large number of patients with triple-negative breast cancer have impaired DNA repair function and that therefore a poly ADP-ribose polymerase inhibitor may be an effective drug in the treatment of this disease. Notably, homozygous deletion of three genes, EPHA5, MITF, and ACSL3, was significantly associated with an increased risk of recurrence or distant metastasis in adjuvant chemotherapy-treated patients.

HER-2 Positive Breast Cancer - a Mini-Review

Breast cancer is one of among all cancers with increased incidence, high mortality rate, and high economic and social costs. The the most common type of cancer among females worldwide, breast cancer is actually the uncontrolled proliferation of cells which attain malignancy. Recently it has shown that breast cancer contributes 11% among all types of cancer diagnosed globally on an annual basis and it is one of the leading causes of death among women. The human epidermal growth factor receptor 2 (HER-2) is a receptor tyrosine-protein kinase erbB-2 normally involved in the proliferation and division of breast cells. In some abnormal cases the HER2 gene does not work correctly and makes too many copies of itself. HER2-positive (HER2+) breast cancers constitute an aggressive type of breast cancer and tend to grow faster and are more likely to spread. However, therapies that specifically target HER2, such as Herceptin® (traztuzumab), are very effective. HER2 targeted therapies, has significantly improved the therapeutic outcome for patients with HER2 positive breast cancer.

Interaction of MRE11 and Clinicopathologic Characteristics in Recurrence of Breast Cancer: Individual and Cumulated Receiver Operating Characteristic Analyses

The interaction between the meiotic recombination 11 homolog A (MRE11) oncoprotein and breast cancer recurrence status remains unclear. The aim of this study was to assess the interaction between MRE11 and clinicopathologic variables in breast cancer. A dataset for 254 subjects with breast cancer (220 nonrecurrent and 34 recurrent) was used in individual and cumulated receiver operating characteristic (ROC) analyses of MRE11 and 12 clinicopathologic variables for predicting breast cancer recurrence. In individual ROC analysis, the area under curve (AUC) for each predictor of breast cancer recurrence was smaller than 0.7. In cumulated ROC analysis, however, the AUC value for each predictor improved. Ten relevant variables in breast cancer recurrence were used to find the optimal prognostic indicators. The presence of any six of the following ten variables had a high (79%) sensitivity and a high (70%) specificity for predicting breast cancer recurrence: tumor size ≥ 2.4 cm, tumor stage II/III, therapy other than hormone therapy, age ≥ 52 years, MRE11 positive cells > 50%, body mass index ≥ 24, lymph node metastasis, positivity for progesterone receptor, positivity for epidermal growth factor receptor, and negativity for estrogen receptor. In conclusion, this study revealed that these 10 clinicopathologic variables are the minimum discriminators needed for optimal discriminant effectiveness in predicting breast cancer recurrence.

Potential role of targeted therapies in the treatment of triple-negative breast cancer

Breast cancer is the most common cancer type that affects women and is the major cause of morbidity and mortality. Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype and accounts for 10-20% of all breast cancer cases. TNBC is commonly characterized by the absence of estrogen, progesterone, and the Her2/neu receptor and is usually diagnosed by immunohistochemistry. Mutations in the BRCA1 gene, as well as overexpression of oncogenic kinases, such as human epidermal growth factor receptor 2, vascular endothelial growth factor-A, insulin-like growth factor-1 (IGF-1)/IGF-1 receptor, and transforming growth factor-β1, have been found to be correlated with a higher risk of metastasis and poor overall survival in TNBC patients. The current review briefly discusses the various treatment options including chemotherapeutics and targeted therapies that are available currently for the therapy of TNBC patients and highlights their comparative benefits and disadvantages for clinical application.

Effects of metformin on cell kinetic parameters of MCF-7 breast cancer cells in vitro

In this study, the antiproliferative effects of the metformin was evaluated on MCF-7 Cells (human breast adenocarcinoma cell line). For this purpose cell kinetic parameters including cell proliferation assay, mitotic index and labelling index analysis were used. 30 μM, 65 μM and 130 μM Metformin doses were applied to cells for 24, 48 and 72 hours. The results showed that there was a significant decrease in cell proliferation, mitotic index and labelling index for all experimental groups (p<0.05) for all applications.

Nifuroxazide induces apoptosis and impairs pulmonary metastasis in breast cancer model

Breast carcinoma is the most common female cancer with considerable metastatic potential. Signal transducers and activators of the transcription 3 (Stat3) signaling pathway is constitutively activated in many cancers including breast cancer and has been validated as a novel potential anticancer target. Here, we reported our finding with nifuroxazide, an antidiarrheal agent identified as a potent inhibitor of Stat3. The potency of nifuroxazide on breast cancer was assessed in vitro and in vivo. In this investigation, we found that nifuroxazide decreased the viability of three breast cancer cell lines and induced apoptosis of cancer cells in a dose-dependent manner. In addition, western blot analysis demonstrated that the occurrence of its apoptosis was associated with activation of cleaved caspases-3 and Bax, downregulation of Bcl-2. Moreover, nifuroxazide markedly blocked cancer cell migration and invasion, and the reduction of phosphorylated-Stat3^Tyr705, matrix metalloproteinase (MMP) MMP-2 and MMP-9 expression were also observed. Furthermore, in our animal experiments, intraperitoneal administration of 50 mg/kg/day nifuroxazide suppressed 4T1 tumor growth and blocked formation of pulmonary metastases without detectable toxicity. Meanwhile, histological and immunohistochemical analyses revealed a decrease in Ki-67-positive cells, MMP-9-positive cells and an increase in cleaved caspase-3-positive cells upon nifuroxazide. Notably, nifuroxazide reduced the number of myeloid-derived suppressor cell in the lung. Our data indicated that nifuroxazide may potentially be a therapeutic agent for growth and metastasis of breast cancer.