Systemic treatment strategies for triple-negative breast cancer

Triple Negative Breast Cancer Treatment Options and Limitations: Future Outlook

Triple negative breast cancer (TNBC) has a negative expression of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptors (HER2). The survival rate for TNBC is generally worse than other breast cancer subtypes. TNBC treatment has made significant advances, but certain limitations remain. Treatment for TNBC can be challenging since the disease has various molecular subtypes. A variety of treatment options are available, such as chemotherapy, immunotherapy, radiotherapy, and surgery. Chemotherapy is the most common of these options. TNBC is generally treated with systemic chemotherapy using drugs such as anthracyclines and taxanes in neoadjuvant or adjuvant settings. Developing resistance to anticancer drugs and off-target toxicity are the primary hindrances to chemotherapeutic solutions for cancer. It is imperative that researchers, clinicians, and pharmaceutical companies work together to develop effective treatment options for TNBC. Several studies have suggested nanotechnology as a potential solution to the problem of suboptimal TNBC treatment. In this review, we summarized possible treatment options for TNBC, including chemotherapy, immunotherapy, targeted therapy, combination therapy, and nanoparticle-based therapy, and some solutions for the treatment of TNBC in the future. Moreover, we gave general information about TNBC in terms of its characteristics and aggressiveness.

Pd(II) and Pt(II) Trinuclear Chelates with Spermidine: Selective Anticancer Activity towards TNBC-Sensitive and -Resistant to Cisplatin

Triple-negative breast cancer (TNBC) is one of the most aggressive forms of breast cancer and constitutes 10-20% of all breast cancer cases. Even though platinum-based drugs such as cisplatin and carboplatin are effective in TNBC patients, their toxicity and development of cancer drug resistance often hamper their clinical use. Hence, novel drug entities with improved tolerability and selectivity profiles, as well as the ability to surpass resistance, are needed. The current study focuses on Pd(II) and Pt(II) trinuclear chelates with spermidine (Pd₃Spd₂ and Pt₃Spd₂) for evaluating their antineoplastic activity having been assessed towards (i) cisplatin-resistant TNBC cells (MDA-MB-231/R), (ii) cisplatin-sensitive TNBC cells (MDA-MB-231) and (iii) non-cancerous human breast cells (MCF-12A, to assess the cancer selectivity/selectivity index). Additionally, the complexes' ability to overcome acquired resistance (resistance index) was determined. This study revealed that Pd₃Spd₂ activity greatly exceeds that displayed by its Pt analog. In addition, Pd₃Spd₂ evidenced a similar antiproliferative activity in both sensitive and resistant TNBC cells (IC₅₀ values 4.65-8.99 µM and 9.24-13.34 µM, respectively), with a resistance index lower than 2.3. Moreover, this Pd compound showed a promising selectivity index ratio: >6.28 for MDA-MB-231 cells and >4.59 for MDA-MB-231/R cells. Altogether, the data presently gathered reveal Pd₃Spd₂ as a new, promising metal-based anticancer agent, which should be further explored for the treatment of TNBC and its cisplatin-resistant forms.

Value of apparent diffusion coefficient factor in correlation with the molecular subtypes, tumor grade, and expression of Ki-67 in breast cancer

Background

Breast cancer is known to be the most common cancer in women; in the last decade, contrast-enhanced magnetic resonance imaging has become an important tool in the diagnosis of cancer breast. Numerous studies have analyzed associations between imaging and histopathological features as well as the proliferation potential of breast cancer. The purpose of this study was to evaluate the relationship between the apparent diffusion coefficient (ADC) and expression of Ki-67 as well as tumor molecular subtype in breast cancer.

Results

No significant difference between the mean ADC value of tumors of grade I, II, and III was found. However, there was a significant difference between the mean ADC value of tumors of molecular type A and molecular type B (P = 0.000), HER2 overexpression (P = 0.018), and TN (P = 0.000), respectively. However, there was no significant difference between molecular type B, HER2 overexpression and TN. Also, no significant difference was found between the Ki-67 value of tumors of grade I, II, and III. Yet there was a significant difference between the mean ADC value of tumors of molecular type A and molecular type B (P = 0.000), HER2 overexpression (P = 0.014), and TN (P = 0.000), respectively. However, there was no significant difference between molecular type B, HER2 overexpression, and TN.

Conclusions

There is a significant inverse correlation between ADC values and Ki-67 expression. DWI and Ki-67 could be a good discriminator between tumors of molecular subtype A from other subtypes, yet it did not show a correlation with the tumor grade.

Molecular-Genetic Portrait of Breast Cancer with Triple Negative Phenotype

Simple Summary

Breast cancer is a genetically heterogeneous disease with different molecular biological and clinical characteristics. The available knowledge about the genetic heterogeneity of the most aggressive molecular subtype of breast cancer—triple-negative—has led to discoveries in drug treatment. Identification of the molecular-genetic phenotype of breast cancer is an important prognostic factor of the disease and allows personalization of the patient’s treatment.

Abstract

Understanding of the genetic mechanisms and identification of the biological markers of tumor progression that form the individual molecular phenotype of transformed cells can characterize the degree of tumor malignancy, the ability to metastasize, the hormonal sensitivity, and the effectiveness of chemotherapy, etc. Breast cancer (BC) is a genetically heterogeneous disease with different molecular biological and clinical characteristics. The available knowledge about the genetic heterogeneity of the most aggressive molecular subtype of breast cancer—triple-negative (TN)—has led to discoveries in drug treatment, including the use of DNA damaging agents (platinum and PARP inhibitors) for these tumors, as well as the use of immunotherapy. Most importantly, the ability to prescribe optimal drug treatment regimens for patients with TNBC based on knowledge of the molecular-genetic characteristics of this subtype of BC will allow the achievement of high rates of overall and disease-free survival. Thus, identification of the molecular-genetic phenotype of breast cancer is an important prognostic factor of the disease and allows personalization of the patient’s treatment.

Screening mammography mitigates breast cancer disparities through early detection of triple negative breast cancer

PURPOSE

Screening mammography improves breast cancer survival through early detection, but Triple Negative Breast Cancer (TNBC) is more difficult to detect on mammography and has lower survival compared to non-TNBC, even when detected at early stages. TNBC is twice as common among African American (AA) compared to White American (WA) women, thereby contributing to the 40% higher breast cancer mortality rates observed in AA women. The role of screening mammography in addressing breast cancer disparities is therefore worthy of study.

METHODS

Outcomes were evaluated for TNBC patients treated in the prospectively-maintained databases of academic cancer programs in two metropolitan cities of the Northeast and Midwest, 1998-2018.

RESULTS

Of 756 TNBC cases, 301 (39.8%) were mammographically screen-detected. 46% of 189 AA and 38.5% of 460 WA patients had screen-detected TNBC (p = 0.16). 25.3% of 257 TNBC cases ≤50 years old had screen-detected disease compared to 47.3% of 499 TNBC cases >50 years old (p < 0.0001). 220/301 (73.1%) screen-detected TNBC cases were T1 lesions versus 118/359 (32.9%) non-screen-detected cases (p < 0.0001). Screen-detected TNBC was more likely to be node-negative (51.9% v. 40.4%; p < 0.0001). Five-year overall survival was better in screen-detected TNBC compared to nonscreen-detected TNBC (92.8% v. 81.5%; p < 0.0001) in the entire cohort. The magnitude of this effect was most significant among AA patients (Fig. 1). Screening-related survival patterns were similar among AA and WA patients in both cities.

CONCLUSION

Data from two different cities demonstrates the value of screening mammography to mitigate breast cancer disparities in AA women through the early detection of TNBC.

Cell-derived biomimetic nanocarriers for targeted cancer therapy: cell membranes and extracellular vesicles

Nanotechnology provides synthetic carriers for cancer drug delivery that protect cargos from degradation, control drug release and increase local accumulation at tumors. However, these non-natural vehicles display poor tumor targeting and potential toxicity and are eliminated by the immune system. Recently, biomimetic nanocarriers have been widely developed based on the concept of ‘mimicking nature.’ Among them, cell-derived biomimetic vehicles have become the focus of bionics research because of their multiple natural functions, such as low immunogenicity, long circulation time and targeting ability. Cell membrane-coated carriers and extracellular vesicles are two widely used cell-based biomimetic materials. Here, this review summarizes the latest progress in the application of these two biomimetic carriers in targeted cancer therapy. Their properties and performance are compared, and their future challenges and development prospects are discussed.

Sensitization of MCF7 Cells with High Notch1 Activity by Cisplatin and Histone Deacetylase Inhibitors Applied Together

Histone deacetylase inhibitors (HDIs) are promising anti-cancer agents that inhibit proliferation of many types of cancer cells including breast carcinoma (BC) cells. In the present study, we investigated the influence of the Notch1 activity level on the pharmacological interaction between cisplatin (CDDP) and two HDIs, valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA, vorinostat), in luminal-like BC cells. The type of drug-drug interaction between CDDP and HDIs was determined by isobolographic analysis. MCF7 cells were genetically modified to express differential levels of Notch1 activity. The cytotoxic effect of SAHA or VPA was higher on cells with decreased Notch1 activity and lower for cells with increased Notch1 activity than native BC cells. The isobolographic analysis demonstrated that combinations of CDDP with SAHA or VPA at a fixed ratio of 1:1 exerted additive or additive with tendency toward synergism interactions. Therefore, treatment of CDDP with HDIs could be used to optimize a combined therapy based on CDDP against Notch1-altered luminal BC. In conclusion, the combined therapy of HDIs and CDDP may be a promising therapeutic tool in the treatment of luminal-type BC with altered Notch1 activity.

Extraction of chlorophyll and carotenoids loaded into chitosan as potential targeted therapy and bio imaging agents for breast carcinoma

In the current study, the treatment efficacy of ECHCAH was evaluated in vitro studies using cell viability and flow cytometry in human TNBCs. The results here showed significant gradual reduction in growth of TNBCs (MDA-231cell lines) after their exposure to serial concentrations for hydrogel assembly (5 μg/mL to 25 μg/mL) for 24 and 48 h, representing (86 ± 1% to 45 ± 1.5% p < 0.001) and (79 ± 1.5% to 35 ± 2.5% p < 0.001) respectively. The flow cytometry showed significant increase in the present of late apoptotic and necrotic cells (64% ± 1.2 and 27% ± 0.3 p < 0.001) after 48 h incubation compared to untreated cells (1.13% ± 0.3 and 4% ± 0.2 p < 0.001) respectively. It can be summarized that ECHCA inside targeted hydrogel assemblies can inhibit proliferation of cancer cells.

Toward developing a metastatic breast cancer treatment strategy that incorporates history of response to previous treatments

Background

Information regarding response to past treatments may provide clues concerning the classes of drugs most or least likely to work for a particular metastatic or neoadjuvant early stage breast cancer patient. However, currently there is no systematized knowledge base that would support clinical treatment decision-making that takes response history into account.

Methods

To model history-dependent response data we leveraged a published in vitro breast cancer viability dataset (84 cell lines, 90 therapeutic compounds) to calculate the odds ratios (log (OR)) of responding to each drug given knowledge of (intrinsic/prior) response to all other agents. This OR matrix assumes (1) response is based on intrinsic rather than acquired characteristics, and (2) intrinsic sensitivity remains unchanged at the time of the next decision point. Fisher’s exact test is used to identify predictive pairs and groups of agents (BH p < 0.05). Recommendation systems are used to make further drug recommendations based on past ‘history’ of response.

Results

Of the 90 compounds, 57 have sensitivity profiles significantly associated with those of at least one other agent, mostly targeted drugs. Nearly all associations are positive, with (intrinsic/prior) sensitivity to one agent predicting sensitivity to others in the same or a related class (OR > 1). In vitro conditional response patterns clustered compounds into five predictive classes: (1) DNA damaging agents, (2) Aurora A kinase and cell cycle checkpoint inhibitors; (3) microtubule poisons; (4) HER2/EGFR inhibitors; and (5) PIK3C catalytic subunit inhibitors. The apriori algorithm implementation made further predictions including a directional association between resistance to HER2 inhibition and sensitivity to proteasome inhibitors.

Conclusions

Investigating drug sensitivity conditioned on observed sensitivity or resistance to prior drugs may be pivotal in informing clinicians deciding on the next line of breast cancer treatments for patients who have progressed on their current treatment. This study supports a strategy of treating patients with different agents in the same class where an associated sensitivity was observed, likely after one or more intervening treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07912-7.

Insights Into the Impacts of BRCA Mutations on Clinicopathology and Management of Early-Onset Triple-Negative Breast Cancer

Background

Little is known regarding the clinicopathologic characteristics, oncologic outcomes, and treatment strategies that could be ascribed to BRCA mutation in early-onset triple-negative breast cancer (eTNBC).

Methods

eTNBC patients who underwent BRCA genetic testing were derived from our clinical database between 2012 and 2018. Differences in clinical features and pathologic characteristics were examined in groups divided by BRCA mutation status, and the contribution of germline mutations in conjunction with treatment modalities to survival outcomes was determined.

Results

Of the 355 qualifying eTNBC patients, 67 (18.87%) were BRCA mutated and 288 (81.13%) were BRCA wild. Overall, median age at diagnosis was 34 years (range, 24-40 years) in the BRCA mutated subgroup and 35 years (range, 21-40 years) in BRCA wild. The majority of clinicopathologic parameters were parallel; however, tumor size (P = 0.07) and nuclear grade (P =0.08) tend to be more aggressive in the BRCA mutated subgroup. Compared with BRCA wild patients, BRCA mutated patients had a higher likelihood of receiving anthracyclines and taxane-based combination chemotherapy (P = 0.04) and tend to be lower tumor burden (P =0.01). After approximately 5-year median follow-up, the overall survival (OS) (P = 0.021) and breast cancer-specific survival (BCSS) (P = 0.004) in BRCA mutated patients were superior to those in their BRCA wild counterparts. Intriguingly, the clinical outcomes were comparable in patients with breast conserving surgery (BCS) regardless of BRCA mutations and in patients with BRCA mutations in spite of surgical schedules.

Conclusions

These results suggest that eTNBC patients with BRCA mutations are prone to better OS and BCSS, which might be largely attributed to more benefit from anthracyclines and taxane-based chemotherapy. The BCS procedure could be a safe alternative surgical option for eTNBC patients with BRCA mutations. Future studies with substantial numbers of participants are urgently needed to validate whether BRCA mutation eTNBC patients are more sensitive to chemotherapy.

Mining Natural Compounds to Target WNT Signaling: Land and Sea Tales

WNT signaling plays paramount roles in organism development, physiology, and disease, representing a highly attractive target for drug development. However, no WNT-modulating drugs have been approved, with several candidates trudging through the early clinical trials. This delay instigates alternative approaches to discover WNT-modulating drugs. Natural products were the source of therapeutics for centuries, but the chemical diversity they offer, especially when looking at different taxonomic groups and habitats, is still to a large extent unexplored. These considerations urge researchers to screen natural compounds for the WNT-modulatory activities. Since several reviews on such endeavors exist, we here have attempted to present these efforts as "Land and sea tales" (citing the book title by Rudyard Kipling) superimposing them onto the traditional pipeline of drug discovery and early development. In doing so, we illustrate each step of the pipeline with case studies stemming from our own research. It will become obvious that several steps of the pipeline need to be modified when applied to natural products rather than to synthetic libraries. Yet the main message of this chapter is that natural compounds represent a powerful source for the WNT signaling modulators and can be developed towards drug candidates against WNT-dependent maladies.

Triple-Negative Breast Cancer Comparison With Canine Mammary Tumors From Light Microscopy to Molecular Pathology

Many similar characteristics in human and dog cancers including, spontaneous development, clinical presentation, tumor heterogeneity, disease progression, and response to standard therapies have promoted the approval of this comparative model as an alternative to mice. Breast cancer represents the second most frequent neoplasm in humans after lung cancer. Triple-negative breast cancers (TNBC) constitute around 15% of all cases of breast cancer and do not express estrogen receptor (ER), progesterone receptor (PR), and do not overexpress human epidermal growth factor receptor 2 (HER2). As a result, they do not benefit from hormonal or trastuzumab-based therapy. Patients with TNBC have worse overall survival than patients with non-TNBC. Lehmann and collaborators described six different molecular subtypes of TNBC which further demonstrated its transcriptional heterogeneity. This six TNBC subtype classification has therapeutic implications. Breast cancer is the second most frequent neoplasm in sexually intact female dogs after skin cancer. Canine mammary tumors are a naturally occurring heterogeneous group of cancers that have several features in common with human breast cancer (HBC). These similarities include etiology, signaling pathway activation, and histological classification. Molecularly CMTs are more like TNBCs, and therefore dogs are powerful spontaneous models of cancer to test new therapeutic approaches, particularly for human TNBCs. More malignant tumors of the breast are more often ER and PR negative in both humans and dogs. Promising breast cancer biomarkers in both humans and canines are cancer-associated stroma (CAS), circulating tumor cells and tumor DNA (ctDNA), exosomes and miRNAs, and metabolites.

IL-8 and MCP-1/CCL2 regulate proteolytic activity in triple negative inflammatory breast cancer a mechanism that might be modulated by Src and Erk1/2

Inflammatory breast cancer (IBC) is a highly metastatic and lethal breast cancer. As many as 25-30% of IBCs are triple negative (TN) and associated with low survival rates and poor prognosis. We found that the microenvironment of IBC is characterized by high infiltration of tumor associated macrophages (TAMs) and by over-expression of the cysteine protease cathepsin B (CTSB). TAMs in IBC secrete high levels of the cytokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1/CCL2) compared to non-IBC patients. Herein, we tested the roles of IL-8 and MCP-1/CCL2 in modulating proteolytic activity and invasiveness of TN-non-IBC as compared to TN-IBC and addressed the underlying molecular mechanism(s) for both cytokines. Quantitative real time PCR results showed that IL-8 and MCP-1/CCL2 were significantly overexpressed in tissues of TN-IBCs. IL-8 and MCP-1/CCL2 induced CTSB expression and activity of the p-Src and p-Erk1/2 signaling pathways relevant for invasion and metastasis in TN-non-IBC, HCC70 cells and TN-IBC, SUM149 cells. Dasatinib, an inhibitor of p-Src, and U0126, an inhibitor of p-Erk1/2, down-regulated invasion and expression of CTSB by HCC70 and SUM149 cells, a mechanism that is reversed by IL-8 and MCP-1/CCL2. Our study shows that targeting the cytokines IL-8 and MCP-1/CCL2 and associated signaling molecules may represent a promising therapeutic strategy in TN-IBC patients.

Engineering macrophage-derived exosomes for targeted chemotherapy of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most metastatic and recurrent subtype of all breast cancers. Owing to the lack of therapeutic targets, chemotherapy and surgical intervention are the only treatments for TNBC. However, the effectiveness of chemotherapeutics is limited by its shortcomings such as poor targeting, easy removal and high toxicity. Recently, exosomes have attracted more and more attention as a drug delivery system. As endogenous vesicles, exosomes ensure low immunogenicity, nontoxicity, and long blood circulation time. In addition, immune cell-derived exosomes can mimic the immune cell to target tumor cells. Herein, we developed a macrophage-derived exosome-coated poly(lactic-co-glycolic acid) nanoplatform for targeted chemotherapy of TNBC. To further improve the tumor targetability, the surface of the exosome was modified with a peptide to target the mesenchymal-epithelial transition factor (c-Met), which is overexpressed by TNBC cells. The results showed that the engineered exosome-coated nanoparticles significantly improved the cellular uptake efficiency and the antitumor efficacy of doxorubicin. In vivo study demonstrated that the nanocarriers exhibited remarkable tumor-targeting efficacy, led to increased inhibition of tumor growth and induced intense tumor apoptosis. These results indicated that the engineered macrophage exosome-coated nanoparticles were a promising drug delivery strategy for TNBC treatment.

Simultaneous targeting of HER family pro-survival signaling with Pan-HER antibody mixture is highly effective in TNBC: a preclinical trial with PDXs

BACKGROUND

The human epidermal growth factor receptor (HER) family, notably EGFR, is overexpressed in most triple-negative breast cancer (TNBC) cases and provides cancer cells with compensatory signals that greatly contribute to the survival and development of resistance in response to therapy. This study investigated the effects of Pan-HER (Symphogen, Ballerup, Denmark), a novel mixture of six monoclonal antibodies directed against members of the HER family EGFR, HER2, and HER3, in a preclinical trial of TNBC patient-derived xenografts (PDXs).

METHODS

Fifteen low passage TNBC PDX tumor samples were transferred into the right mammary fat pad of mice for engraftment. When tumors reached an average size of 100-200 mm3, mice were randomized (n ≥ 6 per group) and treated following three 1-week cycles consisting of three times/week intraperitoneal (IP) injection of either formulation buffer (vehicle control) or Pan-HER (50 mg/kg). At the end of treatment, tumors were collected for Western blot, RNA, and immunohistochemistry analyses.

RESULTS

All 15 TNBC PDXs were responsive to Pan-HER treatment, showing significant reductions in tumor growth consistent with Pan-HER-mediated tumor downmodulation of EGFR and HER3 protein levels and significantly decreased activation of associated HER family signaling pathways AKT and ERK. Tumor regression was observed in five of the models, which corresponded to those PDX tumor models with the highest level of HER family activation.

CONCLUSIONS

The marked effect of Pan-HER in numerous HER family-dependent TNBC PDX models justifies further studies of Pan-HER in TNBC clinical trials as a potential therapeutic option.

Hydrogen sulfide and its donors: Novel antitumor and antimetastatic therapies for triple-negative breast cancer

Hydrogen sulfide (H₂S) is considered as a novel second-messenger molecule associated with the modulation of various physiological and pathological processes. In the field of antitumor research, endogenous H₂S induces angiogenesis, accelerates the cell cycle and inhibits apoptosis, which results in promoting oncogenesis eventually. Interestingly, high concentrations of exogenous H₂S liberated from donors suppress the growth of various tumors via inducing cellular acidification and modulating several signaling pathways involved in cell cycle regulation, proliferation, apoptosis and metastasis. The selective release of certain concentrations of H₂S from H₂S donors in the target has been considered as an alternative tumor therapy strategy. Triple-negative breast cancer (TNBC), an aggressive subtype with less than one year median survival time, is known to account for approximately 15–20% of all breast cancers. Due to the lack of approved targeted therapy, the clinical treatment of TNBC is still hindered by metastasis as well as recurrence. Significant efforts have been spent on developing novel treatments of TNBC, and remarkable progress in the control of TNBC by H₂S donors and their derivatives have been made in recent years. This review summarizes various pathways involved in antitumor and anti-metastasis effects of H₂S donors and their derivatives on TNBC, which provides novel insights for TNBC treatment.

Can NF-κB Be Considered a Valid Drug Target in Neoplastic Diseases? Our Point of View

Multidrug resistance (MDR), of the innate and acquired types, is one of major problems in treating tumor diseases with a good chance of success. In this review, we examine the key role of nuclear factor-kappa B (NF-κB) to induce MDR in three tumor models characterized precisely by innate or acquired MDR, in particular triple negative breast cancer (TNBC), hepatocellular carcinoma (HCC), and acute myeloid leukemia (AML). We also present different pharmacological approaches that our group have employed to reduce the expression/activation of this transcriptional factor and thus to restore chemo-sensitivity. Finally, we examine the latest scientific evidence found by other groups, the most significant clinical trials regarding NF-κB, and new perspectives on the possibility to consider this transcriptional factor a valid drug target in neoplastic diseases.

The changing role of pathologists from morphologists to molecular pathologists in the era of precision medicine

Pathology is the study of human illness. Throughout centuries of scientific discoveries, pathologic examination of tissue samples has been the gold standard for diagnosis and pathologists have been involved in the elucidation of aetiology, assessment of the biology, clinicopathologic correlation and prediction of prognosis. The advances in science and technology and focused interest in breast cancer research have provided ample opportunities for pathologists to participate in better understanding of the basic fundamental cascade of events leading to tumorigenesis in breast cancer. They also partnered with their clinical colleagues and scientists to find more effective therapeutic options. This change has been possible with recognition of the fact that morphology alone may not be sufficient to tell the entire story of clinical behaviour of all breast cancer patients. In addition, the realization of heterogeneity of breast cancer and the differences in the expression of various biomarkers and the observed differences in response to therapy have resulted in extensive efforts to better define the characters of each breast cancer subtype. It is now generally agreed that breast cancer is not a single disease and not all patients with breast cancer can benefit from the same therapy. These changes have brought new challenges for pathologists. Pathologist are now required to not only provide diagnosis, but also study the precise molecular characterization of each individual breast cancer case and play a significant role in the treatment planning of breast cancer patients. This remarkable change in the role of the pathologist require his/her involvement in the modern taxonomy of this disease and to rise to the challenge of genomic medicine and molecular diagnostics, which are the fastest growing areas of medicine. Emphasis should also been placed to create a new morphomolecular pathology and train our young pathologist to expand beyond morphology and to embrace the power of molecular diagnostics, in order to be able to effectively practise in the era of precision medicine.

Additive Pharmacological Interaction between Cisplatin (CDDP) and Histone Deacetylase Inhibitors (HDIs) in MDA-MB-231 Triple Negative Breast Cancer (TNBC) Cells with Altered Notch1 Activity-An Isobolographic Analysis

The aim of this study was to investigate the influence of the Notch1 activity level on the pharmacological interaction between cisplatin (CDDP) and two histone deacetylase inhibitors (HDIs)-valproic acid (VPA) and vorinostat (SAHA) in the triple negative breast cancer (TNBC) cells. Stable breast cancer (BC) cell lines with increased and decreased activity of Notch1 were generated using a transfection method. The type of interaction between CDDP and the HDIs was determined by isobolographic analysis of cell proliferation in MDA-MB-231 cells with differential levels of Notch1 activity in vitro. The combination of CDDP/SAHA and CDDP/VPA in the MDA-MB-231 triple negative breast cancer (TNBC) cells with increased activity of Notch1, as well as CDDP/VPA in the MDA-MB-231 cells with decreased activity of Notch1, yielded an additive interaction, whereas additivity with a tendency towards antagonism was observed for the combination of CDDP/SAHA in MDA-MB-231 cells with the decreased activity of Notch1. Our studies demonstrated that SAHA and VPA might be considered as potential therapeutic agents in combination therapy with CDDP against TNBC with altered Notch1 activity.

The treatment role of Cyperus rotundus L. to triple-negative breast cancer cells

Cyperus rotundus L. is widely used in Traditional Chinese Medicine and studies have reported its anticancer effect, but its chemical composition and therapy mechanism remains unknown. This research aims to analyze the chemical components of the ethanol extract of Cyperus rotundus L. (EECR), detect its treatment effects on human Triple-negative breast cancer (TNBC) cells, and elucidate possible therapy mechanisms. The chemical components of EECR were detected by the Waters UPLC combined with Bruker Q-TOF mass spectrometer (UPLC-Q-TOF-MS). The phytochemical compounds were identified by comparing the mass fragmentations of each metabolite with databases such as METLIN, HMDB, and NCBI. A total of 21 compounds were identified in EECR. MDA-MB-231 and MDA-MB-468 cells were treated with various concentrations of EECR. Cell proliferation was examined using Cell Counting Kit-8 (CCK-8) and colony formation assays. Cell apoptosis and cell cycle were detected by flow cytometry. Apoptosis- and autophagy-related protein expression was detected by Western blot. EECR inhibits the proliferation of TNBC cells (MDA-MB-231 and MDA-MB-468) in a dose-dependent manner, which may be related to the arrest of cell cycle in G0/G1 phase. It induces apoptosis by promoting the expression of BAX and inhibiting the expression of BCL-2. In addition, autophagy inhibitor 3-Methyladenine (3-MA) inhibited TNBC cells pro-survival autophagy and increased the sensitivity of EECR. The present results demonstrated that EECR has potential effects on inhibits the proliferation and induction apoptosis in TNBC.

The triacylglycerol, hydroxytriolein, inhibits triple negative mammary breast cancer cell proliferation through a mechanism dependent on dihydroceramide and Akt

The plasma membrane is an attractive target for new anticancer drugs, not least because regulating its lipid structure can control multiple signaling pathways involved in cancer cell proliferation, differentiation and survival. Accordingly, the novel anticancer drug hydroxytriolein (HTO) was designed to interact with and regulate the composition and structure of the membrane, which in turn controls the interaction of amphitropic signaling membrane proteins with the lipid bilayer. Changes in signaling provoked by HTO impair the growth of triple negative breast cancer (TNBC) cells, aggressive breast tumor cells that have a worse prognosis than other types of breast cancers and for which there is as yet no effective targeted therapy. HTO alters the lipid composition and structure of cancer cell membranes, inhibiting the growth of MDA-MB-231 and BT-549 TNBC cells in vitro. Depending on the cellular context, HTO could regulate two pathways involved in TNBC cell proliferation. On the one hand, HTO might stimulate ERK signaling and induce TNBC cell autophagy, while on the other, it could increase dihydroceramide and ceramide production, which would inhibit Akt independently of EGFR activation and provoke cell death. In vivo studies using a model of human TNBC show that HTO and its fatty acid constituent (2-hydroxyoleic acid) impair tumor growth, with no undesired side effects. For these reasons, HTO appears to be a promising anticancer molecule that targets the lipid bilayer (membrane-lipid therapy). By regulating membrane lipids, HTO controls important signaling pathways involved in cancer cell growth, the basis of its pharmacological efficacy and safety.

Towards the first targeted therapy for triple-negative breast cancer: Repositioning of clofazimine as a chemotherapy-compatible selective Wnt pathway inhibitor

Wnt signaling is overactivated in triple-negative breast cancer (TNBC) and several other cancers, and its suppression emerges as an effective anticancer treatment. However, no drugs targeting the Wnt pathway exist on the market nor in advanced clinical trials. Here we provide a comprehensive body of preclinical evidence that an anti-leprotic drug clofazimine is effective against TNBC. Clofazimine specifically inhibits canonical Wnt signaling in a panel of TNBC cells in vitro. In several mouse xenograft models of TNBC, clofazimine efficiently suppresses tumor growth, correlating with in vivo inhibition of the Wnt pathway in the tumors. Clofazimine is well compatible with doxorubicin, exerting additive effects on tumor growth suppression, producing no adverse effects. Its excellent and well-characterized pharmacokinetics profile, lack of serious adverse effects at moderate (yet therapeutically effective) doses, its combinability with cytotoxic therapeutics, and the novel mechanistic mode of action make clofazimine a prime candidate for the repositioning clinical trials. Our work may bring forward the anti-Wnt targeted therapy, desperately needed for thousands of patients currently lacking targeted treatments.

ATG9A Is Overexpressed in Triple Negative Breast Cancer and Its In Vitro Extinction Leads to the Inhibition of Pro-Cancer Phenotypes

Early detection and targeted treatments have led to a significant decrease in mortality linked to breast cancer (BC), however, important issues need to be addressed in the future. One of them will be to find new triple negative breast cancer (TNBC) therapeutic strategies, since none are currently efficiently targeting this subtype of BC. Since numerous studies have reported the possibility of targeting the autophagy pathway to treat or limit cancer progression, we analyzed the expression of six autophagy genes (ATG9A, ATG9B, BECLIN1, LC3B, NIX and P62/SQSTM1) in breast cancer tissue, and compared their expression with healthy adjacent tissue. In our study, we observed an increase in ATG9A mRNA expression in TNBC samples from our breast cancer cohort. We also showed that this increase of the transcript was confirmed at the protein level on paraffin-embedded tissues. To corroborate these in vivo data, we designed shRNA- and CRISPR/Cas9-driven inhibition of ATG9A expression in the triple negative breast cancer cell line MDA-MB-436, in order to determine its role in the regulation of cancer phenotypes. We found that ATG9A inhibition led to an inhibition of in vitro cancer features, suggesting that ATG9A can be considered as a new marker of TNBC and might be considered in the future as a target to develop new specific TNBC therapies.

Lithium chloride attenuates mitomycin C induced necrotic cell death in MDA-MB-231 breast cancer cells via HMGB1 and Bax signaling

The clinical use of potent anticancer drug mitomycin C (MMC) has limited due to side effects and resistance of cancer cells. The aim of this study was to investigate whether lithium chloride (LiCl), as a mood stabilizer, can affect the sensitivity of MDA-MB-231 breast cancer cells to mitomycin C. The cells were exposed to various concentrations of mitomycin C alone and combined with LiCl and the viability determined by trypan blue and MTT assays. Proteins were analyzed by western blot and mRNA expression of HMGB1 MMP9 and Bcl-2 were analyzed by RT-PCR. Flow cytometry was used to determine the cell cycle arrest and percent of apoptotic and necrotic cells. Concentration of Bax assessed by ELISA. Exposure of the cells to mitomycin C revealed IC₅₀ value of 20 μM, whereas pretreatment of the cells with LiCl induced synergistic cytotoxicity and IC₅₀ value declined to 5 μM. LiCl combined with mitomycin C significantly down-regulated HMGB1, MMP9 and Bcl-2 gene expression but significantly increased the level of Bax protein. In addition, the content of HMGB1 in the nuclei decreased and pretreatment with LiCl reduced the content of HMGB1 release induced by MMC. LiCl increased mitomycin C-induced cell shrinkage and PARP fragmentation suggesting induction of apoptosis in these cells. LiCl prevented mitomycin C-induced necrosis and changed the cell death arrest at G2/M-phase. Taking all together, it is suggested that LiCl efficiently enhances mitomycin C-induced apoptosis and HMGB1, Bax and Bcl-2 expression may play a major role in this process, the findings that provide a new therapeutic strategy for LiCl in combination with mitomycin C.

Antitumor effects of Xi Huang pills on MDA‑MB‑231 cells in vitro and in vivo

The management of patients with triple-negative breast cancer is challenging due to the lack of effective therapeutic options, aggressive behavior and relatively poor prognosis. Xi Huang pills (XHP) are a well-known traditional Chinese medicine that demonstrate anticancer activities. The aim of the present study was to investigate the antitumor effects of XHP on MDA-MB-231 cells in vitro and in vivo, and its potential underlying molecular mechanisms. In the present study, an MTT assay was used to evaluate the antiproliferative activity of XHP on MDA-MB-231 cells. In order to investigate the effects further, cell cycle distribution, apoptosis and mitochondrial membrane potential assays were performed, as well as western blot analyses. In addition, a tumor xenograft model was employed to investigate the effects of XHP in vivo. The results of the MTT assay demonstrated that the viability of MDA-MB-231 cells was markedly inhibited by XHP in a dose- and time-dependent manner. The inhibitory effect of XHP on the viability of MDA-MB-231 cells was greater when compared with MCF-10A cells. An increase in apoptosis and loss of mitochondrial membrane potential was observed following 4, 8 and 12 mg/ml XHP treatment of MDA-MB-231 cells. The protein expression levels of cleaved caspase-3 were increased by 1.62-, 2.13- and 2.19-fold, respectively, when compared with the untreated controls, whereas no effects on the expression of B-cell lymphoma 2 (Bcl-2) or Bcl-2-associated X protein (Bax) were observed. The results of the cell cycle distribution assay analysis demonstrated that XHP treatment arrested cells at the G₂/M phase. In addition, XHP treatment decreased the expression of cyclin A and increased the expression of p21^Cip1. In vivo experiments revealed that XHP inhibited the growth of MDA-MB-231 xenograft tumors without body weight loss, and demonstrated similar effects on the protein expression levels of cleaved caspase 3, cyclin A and p21^Cip1 as observed in vitro. In conclusion, the viability of MDA-MB-231 cells was inhibited by XHP in a dose-dependent, time-dependent and cell-selective manner in vitro, and the potential underlying mechanisms may involve apoptosis and cell cycle arrest at the G₂/M phase. XHP may induce apoptosis in MDA-MB-231 cells via the intrinsic pathway, which does not involve the Bcl-2/Bax ratio. G₂/M phase arrest may have been due to the integrated action of decreased cyclin A expression and increased p21^Cip1 expression. In addition, XHP inhibited the growth of xenograft tumors in the absence of body weight loss in vivo.

Therapeutic positioning of secretory acetylated APE1/Ref-1 requirement for suppression of tumor growth in triple-negative breast cancer in vivo

Triple-negative breast cancer (TNBC) represents a relatively small proportion of all BCs but a relatively large proportion of BC-related death. Thus, more effective therapeutic strategies are needed for the management of TNBC. We demonstrated that the stimulation of apoptosis by the binding of secreted acetylated-apurinic apyrimidinic endonuclease 1/redox factor-1 (Ac-APE1/Ref-1) to the receptor for advanced glycation end products (RAGE) was essential for TNBC cell death in response to hyperacetylation. The aim of the present study was to assess the potential therapeutic efficacy of secretory Ac-APE1/Ref-1 in orthotopic TNBC xenografts in vivo. We found that hyperacetylation in xenografts caused secretion of Ac-APE1/Ref-1 into the blood, where the factor bound directly to RAGE in hyperacetylated tumor tissues. Hyperacetylation in the TNBC xenografts induced strong inhibition of tumor growth and development, leading to apoptotic cell death, accompanied by increased RAGE expression and generation of reactive oxygen species. Tissues exhibited markedly higher counts of apoptotic bodies, a reduced proliferation index, and reduced neovascularization compared with control tumors. Ac-APE1/Ref-1-stimulated apoptosis was markedly reduced in RAGE-knockdown tumors compared with RAGE-overexpressing tumors, even in the presence of hyperacetylation. The function of secreted Ac-APE1/Ref-1 was confirmed in other hyperacetylated TNBCs xenografts using BT-549 and MDA-MB-468 cells, demonstrating its relevance as an anti-cancer molecule.

Clinical study on postoperative triple-negative breast cancer with Chinese medicine: Study protocol for an observational cohort trial

BACKGROUND

Breast cancer (BC) poses a tremendous threat to the health of women worldwide, especially triple-negative breast cancers (TNBCs). Currently, the curative effect of traditional Chinese medicine (TCM) has been recognized in more and more people worldwide; however, the specific effect has not been systematically evaluated. The purpose of this cohort study is to evaluate the clinical effects of TCM syndrome differentiation on recurrence and metastasis rate, survival rate, and the quality of life in patients with TNBC.

METHODS

This study is a multicenter observational cohort trial taking 2 years. A total of 620 patients will be allocated at a ratio of 1:1 to receive TCM or not. The primary outcomes are progression-free survival (PFS) and overall survival (OS), which are calculated at the end of the trial. Secondary outcomes include TCM symptoms, Karnofsky Performance Status (KPS), ECOG score, European Organization for Research and Treatment of Cancer (EORTC) Breast-Cancer-Specific Quality of Life Questionnaire (EORTC QLQ-BR23), as well as clinical indicators including tumor markers, immune function evaluation, chest computed tomography/magnetic resonance imaging, and abdominal B-ultrasound. Assessments will be performed at baseline and 3, 6, 9, 12, 16, and 20 weeks after observation.

DISCUSSION

This will be the first clinical trial to evaluate the PFS and OS in TNBC patients receiving TCM, which may be used to assess the feasibility of a larger-scale clinical trial in the future, and formulate a standardized TCM treatment plan.

STUDY REGISTRATION

ClinicalTrials.gov (NCT03332368).

Binding of galectin-1 to integrin β1 potentiates drug resistance by promoting survivin expression in breast cancer cells

Galectin-1 is a β-galactoside binding protein secreted by many types of aggressive cancer cells. Although many studies have focused on the role of galectin-1 in cancer progression, relatively little attention has been paid to galectin-1 as an extracellular therapeutic target. To elucidate the molecular mechanisms underlying galectin-1-mediated cancer progression, we established galectin-1 knock-down cells via retroviral delivery of short hairpin RNA (shRNA) against galectin-1 in two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and Hs578T. Ablation of galectin-1 expression decreased cell proliferation, migration, invasion, and doxorubicin resistance. We found that these effects were caused by decreased galectin-1-integrin β1 interactions and suppression of the downstream focal adhesion kinase (FAK)/c-Src pathway. We also found that silencing of galectin-1 inhibited extracellular signal-regulated kinase (ERK)/signal transducer and activator of transcription 3 (STAT3) signaling, thereby down-regulating survivin expression. This finding implicates STAT3 as a transcription factor for survivin. Finally, rescue of endogenous galectin-1 knock-down and recombinant galectin-1 treatment both recovered signaling through the FAK/c-Src/ERK/STAT3/survivin pathway. Taken together, these results suggest that extracellular galectin-1 contributes to cancer progression and doxorubicin resistance in TNBC cells. These effects appear to be mediated by galectin-1-induced up-regulation of the integrin β1/FAK/c-Src/ERK/STAT3/survivin pathway. Our results imply that extracellular galectin-1 has potential as a therapeutic target for triple-negative breast cancer.

Phytochemicals: Current strategies for treating breast cancer

Females with early-stage metastatic, estrogen-dependent breast cancer are generally treated with surgery, radiation and chemotherapy, or with more targeted approaches such as aromatase inhibitors (anastrozole or letrozole) or anti-estrogens (tamoxifen). Despite widespread successful usage of these agents for the treatment of breast cancer, resistance, tumor relapse and metastasis remain the principal causes of mortality for patients with breast cancer. While numerous groups have made major contributions toward an improved understanding of resistance mechanisms, the currently insufficient grasp of the most critical pathways involved in resistance is evident in the inability to adequately treat and drastically improve patient outcomes in females with hormone-refractory breast cancer, including triple negative breast cancer. Therefore, further investigation of novel therapeutic approaches is paramount to reveal previously unconsidered agents that could be utilized to treat metastatic disease. Numerous naturally occurring phytochemicals have recently gained interest as potential therapeutic breast cancer agents appear to directly affect estrogen-dependent and estrogen-independent breast cancer cell proliferation, potentially via affecting breast cancer stem cell populations. While numerous natural compounds have exhibited promise, they are limited by their bioavailability. Therefore, to effectively treat future hormone-refractory breast tumors, it is critical to adequately refine and formulate these agents for effective therapeutic use and delivery. Herein, the literature on the current state of phytochemicals is reviewed, including their limitations and potential as targeted therapies for breast cancer.

PITX2 DNA-methylation predicts response to anthracycline-based adjuvant chemotherapy in triple-negative breast cancer patients

Triple-negative breast cancer (TNBC) constitutes a heterogeneous breast cancer subgroup with poor prognosis; survival rates are likely to be lower with TNBC compared to other breast cancer subgroups. For this disease, systemic adjuvant chemotherapy regimens often yield suboptimal clinical results. To improve treatment regimens in TNBC, identification of molecular biomarkers may help to select patients for individualized adjuvant therapy. Evidence has accumulated that determination of the methylation status of the PITX2 gene provides a predictive value in various breast cancer subgroups, either treated with endocrine-based therapy or anthracycline-containing chemotherapy. To further explore the validity of this novel predictive candidate biomarker, in the present exploratory retrospective study, determination of the PITX2 DNA-methylation status was assessed for non-metastatic TNBC patients treated with adjuvant anthracycline-based chemotherapy by molecular analysis of breast cancer tissues. The PITX2 DNA-methylation status was determined in fresh-frozen tumor tissue specimens (n=56) by methylation-specific qRT-PCR (qMSP) and the data related to disease-free and overall survival, applying an optimized DNA-methylation score of 6.35%. For non-metastatic TNBC patients treated with adjuvant systemic anthracycline-based chemotherapy, a low PITX2 DNA-methylation status (<6.35) defines TNBC patients with poor disease-free and overall survival. Univariate and multivariate analyses demonstrate the statistically independent predictive value of PITX2 DNA-methylation. For non-metastatic TNBC patients, selective determination of the PITX2 DNA-methylation status may serve as a cancer biomarker for predicting response to anthracycline-based adjuvant chemotherapy. The assay based on methylation of the PIXT2 gene can be applied to frozen and routinely available formalin-fixed, paraffin-embedded (FFPE) breast cancer tumor tissues that will not only define those TNBC patients who may benefit from anthracycline-based chemotherapy but also those who should be spared the necessity of such potentially toxic treatment. Such patients should be allocated to alternative treatment options.

Interleukin-6 contributes to chemoresistance in MDA-MB-231 cells via targeting HIF-1α

Chemoresistance is a critical challenge in the clinical treatment of triple-negative breast cancer (TNBC). It has been well documented that inflammatory mediators from tumor microenvironment are involved in the pathogenesis of TNBC and might be related to chemoresistance of cancer cells. In this study, the contribution of interleukin-6 (IL-6), one of the principal oncogenic molecules, in chemoresistance of a TNBC cell line MDA-MB-231 was first investigated. The results showed that IL-6 treatment could induce upregulation of HIF-1α via the activation of STAT3 in MDA-MB-231 cells, which consequently contributed to its effect against chemotherapeutic drug-induced cytotoxicity and cell apoptosis. However, knockdown of HIF-1α attenuated such effect via affecting the expressions of apoptosis-related molecules as Bax and Bcl-2 and drug transporters as P-gp and MRP1. This study indicated that targeting at IL-6/HIF-1α signaling pathway might be an effective strategy to overcome chemoresistance in TNBC therapy.

Pharmacological Inhibition of NOS Activates ASK1/JNK Pathway Augmenting Docetaxel-Mediated Apoptosis in Triple-Negative Breast Cancer

Purpose: Chemoresistance in triple-negative breast cancer (TNBC) is associated with the activation of a survival mechanism orchestrated by the endoplasmic reticulum (EnR) stress response and by inducible nitric oxide synthase (iNOS). Our aim was to determine the effects of pharmacologic NOS inhibition on TNBC.Experimental Design: TNBC cell lines, SUM-159PT, MDA-MB-436, and MDA-MB-468, were treated with docetaxel and NOS inhibitor (L-NMMA) for 24, 48, and 72 hours. Apoptosis was assessed by flow cytometry using Annexin-V and propidium iodide. Western blot was used to assess ER stress and apoptosis, and rtPCR was used to evaluate s-XBP1. TNBC patient-derived xenografts (PDX) were treated either with vehicle, docetaxel, or combination therapy (NOS inhibition + docetaxel). Mouse weight and tumor volumes were recorded twice weekly. Docetaxel concentration was determined using mass spectrometry. To quantify proliferation and apoptosis, PDX tumor samples were stained using Ki67 and TUNEL assay.Results:In vitro, L-NMMA ameliorated the iNOS upregulation associated with docetaxel. Apoptosis increased when TNBC cells were treated with combination therapy. In TNBC PDXs, combination therapy significantly reduced tumor volume growth and increased survival proportions. In the BCM-5998 PDX model, intratumoral docetaxel concentration was higher in mice receiving combination therapy. Coupling docetaxel with NOS inhibition increased EnR-stress response via coactivation of ATF4 and CHOP, which triggered the pASK1/JNK proapoptotic pathway, promoting cleavage of caspases 3 and 9.Conclusions: iNOS is a critical target for docetaxel resistance in TNBC. Pharmacologic inhibition of NOS enhanced chemotherapy response in TNBC PDX models. Combination therapy may improve prognosis and prevent relapse in TNBC patients who have failed conventional chemotherapy. Clin Cancer Res; 24(5); 1152-62. ©2018 AACR.

Expression and function of the miR-143/145 cluster in vitro and in vivo in human breast cancer

MicroRNAs (miRNAs) are small non-coding RNAs that function as post-transcriptional regulators of gene expression and are dysregulated in cancer. Studies of miRNAs to explore their potential as diagnostic and prognostic markers are of great scientific interest. Here, we investigate the functional properties and expression of the miR-143/145 cluster in breast cancer (BC) in vitro and in vivo. The ER positive MCF7, the HER2 positive SK-BR-3, and the triple negative cell line MDA-MB-231 were used to assess cell proliferation and cell invasion. Expression of miRNA in 108 breast cancers in the Norwegian Women and Cancer Study and 44 benign tissue controls were analyzed by microarray and validated by RT-PCR. Further, in situ hybridization (ISH) was used to study the cellular and subcellular distribution of the miRNAs. In vitro, miR-143 promoted proliferation of MCF7 and MDA-MB-231 cells, whereas miR-145 and the cotransfection of both miRNAs inhibited proliferation in all three cell lines. The cells’ invasive capacity was reduced after transfection and cotransfection of the miRNAs. In line with the tumor suppressive functions in vitro, the expression of miR-143 and miR-145 was lower in malignant compared to benign breast tissue, and lower in the more aggressive tumors with higher tumor grade, loss of ER and the basal-like phenotype. ISH revealed miR-143 to be cytoplasmatic and predominantly expressed in luminal cells in benign tissue, whilst miR-145 was nuclear and with strong staining in myoepithelial cells. Both miRNAs were present in malignant epithelial cells and stromal fibroblasts in BC. This study demonstrates that miR-143 and -145 have functional properties and expression patterns typical for tumor suppressors, but the function is influenced by cellular factors such as cell type and miRNA cotransfection. Further, the nuclear functions of miR-145 should be explored for a more complete understanding of the complexity of miRNA regulation and function in BC.

A Novel Benzocoumarin-Stilbene Hybrid as a DNA ligase I inhibitor with in vitro and in vivo anti-tumor activity in breast cancer models

Existing cancer therapies are often associated with drug resistance and toxicity, which results in poor prognosis and recurrence of cancer. This necessitates the identification and development of novel therapeutics against existing as well as novel cellular targets. In this study, a novel class of Benzocoumarin-Stilbene hybrid molecules were synthesized and evaluated for their antiproliferative activity against various cancer cell lines followed by in vivo antitumor activity in a mouse model of cancer. The most promising molecule among the series, i.e. compound (E)-4-(3,5-dimethoxystyryl)-2H-benzo[h]chromen-2-one (19) showed maximum antiproliferative activity in breast cancer cell lines (MDA-MB-231 and 4T1) and decreased the tumor size in the in-vivo 4T1 cell-induced orthotopic syngeneic mouse breast cancer model. The mechanistic studies of compound 19 by various biochemical, cell biology and biophysical approaches suggest that the compound binds to and inhibits the human DNA ligase I enzyme activity that might be the cause for significant reduction in tumor growth and may constitute a promising next-generation therapy against breast cancers.

Development and cytotoxic response of two proliferative MDA-MB-231 and non-proliferative SUM1315 three-dimensional cell culture models of triple-negative basal-like breast cancer cell lines

Triple-Negative Basal-Like tumors, representing 15 to 20% of breast cancers, are very aggressive and with poor prognosis. Targeted therapies have been developed extensively in preclinical and clinical studies to open the way for new treatment strategies. The present study has focused on developing 3D cell cultures from SUM1315 and MDA-MB-231, two triple-negative basal-like (TNBL) breast cancer cell lines, using the liquid overlay technique. Extracellular matrix concentration, cell density, proliferation, cell viability, topology and ultrastructure parameters were determined. The results showed that for both cell lines, the best conditioning regimen for compact and homogeneous spheroid formation was to use 1000 cells per well and 2% Geltrex®. This conditioning regimen highlighted two 3D cell models: non-proliferative SUM1315 spheroids and proliferative MDA-MB-231 spheroids. In both cell lines, the comparison of 2D vs 3D cell culture viability in the presence of increasing concentrations of chemotherapeutic agents i.e. cisplatin, docetaxel and epirubicin, showed that spheroids were clearly less sensitive than monolayer cell cultures. Moreover, a proliferative or non-proliferative 3D cell line property would enable determination of cytotoxic and/or cytostatic drug activity. 3D cell culture could be an excellent tool in addition to the arsenal of techniques currently used in preclinical studies.

A network meta-analysis on the efficacy of targeted agents in combination with chemotherapy for treatment of advanced/metastatic triple-negative breast cancer

OBJECTIVE

Our network meta-analysis aimed to determine the assistant efficacy of targeted therapy in combined with chemotherapy for advanced/metastatic triple-negative breast cancer (TNBC).

RESULTS

A total of 15 randomized controlled trials (RCTs), involving 2,410 patients, met our inclusion criteria. Eight targeted agents involving 11 treatment arms were included. The methodological quality of included RCTs was acceptable. The results of direct comparisons showed that progression-free survival (PFS) was significantly longer with bevacizumab+chemotherapy when compared to chemotherapy alone (hazard ratio [HR] = 0.62, 95% credible intervals [CrI]: 0.41-0.87). However, there were no statistically significant differences for all other direct comparison groups. The results of indirect comparison of different targeted agents revealed no significant differences regarding all outcomes of interest. According to ranking probabilities, all outcomes favored bevacizumab+chemotherapy and veliparib+chemotherapy. Bayesian and Frequentist network meta-analysis showed similar results, and the probability of bias of small-study effects was small.

MATERIALS AND METHODS

A comprehensive literature search in PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science (via ISI Web of Knowledge), BIOSIS Previews (via ISI Web of Knowledge), and Chemical Abstracts (CA) was conducted to identify RCTs involving targeted agents in the treatment of advanced/metastatic TNBC. Two reviewers independently extracted related data and assessed the risk of bias of included studies. Bayesian network meta-analysis was conducted using R-3.3.2 software.

CONCLUSIONS

Limited evidence showed that targeted agents combined with chemotherapy for advanced/metastatic TNBC were slightly effective. Further investigation of targeted therapies for TNBC is required to improve patient outcomes. The registration number was CRD42014014299.

The Gαh-PLCδ1 signaling axis drives metastatic progression in triple-negative breast cancer

BACKGROUND

Distant metastasis of triple-negative breast cancer (TNBC) to other organs, e.g., the lungs, has been correlated with poor survival rates among breast cancer patients. Therefore, the identification of useful therapeutic targets to prevent metastasis or even inhibit tumor growth of TNBC is urgently needed. Gαh is a novel GTP-binding protein and known as an inactive form of calcium-dependent tissue transglutaminase. However, the functional consequences of transamidating and G-protein activities of tissue transglutaminase in promoting cancer metastasis are still controversial.

METHODS

Kaplan-Meier analyses were performed to estimate the prognostic values of Gαh and PLCδ1 by utilizing public databases and performing immunohistochemical staining experiments. Cell-based invasion assays and in vivo lung colony-forming and orthotropic lung metastasis models were established to evaluate the effectiveness of interrupting the protein-protein interaction (PPI) between Gαh and PLCδ1 in inhibiting the invasive ability and metastatic potential of TNBC cells.

RESULTS

Here, we showed that the increased level of cytosolic, not extracellular, Gαh is a poor prognostic marker in breast cancer patients and correlates with the metastatic evolution of TNBC cells. Moreover, clinicopathological analyses revealed that the combined signature of high Gαh/PLCδ1 levels indicates worse prognosis in patients with breast cancer and correlates with lymph node metastasis of ER-negative breast cancer. Blocking the PPI of the Gαh/PLCδ1 complex by synthetically myristoylated PLCδ1 peptide corresponding to the Gαh-binding interface appeared to significantly suppress cellular invasiveness in vitro and inhibit lung metastatic colonies of TNBC cells in vivo.

CONCLUSIONS

This study establishes Gαh/PLCδ1 as a poor prognostic factor for patients with estrogen receptor-negative breast cancers, including TNBCs, and provides therapeutic value by targeting the PPI of the Gαh/PLCδ1 complex to combat the metastatic progression of TNBCs.

FOXC1 overexpression is a marker of poor response to anthracycline-based adjuvant chemotherapy in sporadic triple-negative breast cancer

Purpose

Because of its aggressive characteristics and poor prognosis, triple-negative breast cancer (TNBC) has become a hot topic in cancer research. Chemotherapy is currently the only treatment for patients with TNBC. The transcription factor FOXC1 has been associated with TNBC prognosis, but little is known about its effect on chemosensitivity. The aim of this study was to investigate the effects of FOXC1 on chemosensitivity.

Methods

A case–control study was performed on 25 TNBC patients who experienced relapse and/or metastasis. Another 25 patients without relapse or metastasis were randomly selected as controls. Medical records were reviewed for relevant information, and immunohistochemistry was performed to measure FOXC1 levels. The Kaplan–Meier method and Cox analysis were used to analyze differences in disease-free survival (DFS) and overall survival (OS). The correlation of FOXC1 expression with chemosensitivity was analyzed. Data were analyzed using SPSS 21.0 software, and a P value <0.05 was considered to be statistically significant.

Results

In 15 of 22 case patients, FOXC1 was overexpressed, whereas only 8 control patients exhibited FOXC1 overexpression (P < 0.05). FOXC1 expression had no correlation with pathological indicators. An anthracycline-based regimen was administered to 21 study patients and 23 control patients. FOXC1 expression was significantly associated with a worse DFS (HR 2.62, 95% CI 1.05–6.50, P = 0.038) but presented no correlation with OS (HR 2.53, 95% CI 0.76–8.40, P = 0.131) among these 44 patients.

Conclusions

This study shows that FOXC1 is correlated with chemosensitivity to anthracycline and could be used as an indicator of chemosensitivity in sporadic TNBC.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-017-3319-4) contains supplementary material, which is available to authorized users.

Vitamin D receptor, Retinoid X receptor and peroxisome proliferator-activated receptor γ are overexpressed in BRCA1 mutated breast cancer and predict prognosis

Background

BRCA1 mutated breast cancers are commonly diagnosed as negative for classical hormone receptors i.e. estrogen receptor, progesterone receptor and/or Her2. Due to these common targets being absent the application of anti-endocrine therapies is rather limited and a certain focus has been set on discovering alternative target molecules. We recently highlighted thyroid hormone receptors (TRs) to predict prognosis in breast cancer patients that had been diagnosed a BRCA1 germline mutation. Vitamin D Receptor (VDR), Retinoid X Receptor (RXR) and Peroxisome Proliferator-activated Receptor γ (PPARγ) are known to interact with TRs by forming functional heterodimers. Whether VDR, RXR or PPARγ are expressed in BRCA1 mutated breast cancer or may even be present in case of triple negativity is not known. Hence the current study aimed to investigate VDR, RXR and PPARγ in BRCA1^mut breast cancer and to test whether any of the three may be associated with clinico-pathological criteria including overall survival.

Methods

This study analyzed VDR, RXR and PPARγ by immunohistochemistry in BRCA1 associated (n = 38) and sporadic breast cancer (n = 79). Receptors were quantified by applying an established scoring system (IR-score) and were tested for association with clinico-pathological variables.

Results

VDR, RXR and PPARγ were detected in over 90% of triple negative BRCA1^mut breast cancer and were significantly (VDR: p < 0.001, RXR: p = 0.010, PPARγ: p < 0.001) overexpressed in BRCA1 mutated as compared to sporadic cancer cases. VDR and RXR positivity predicted prolonged overall survival only in BRCA1 mutated cases while such association was not observed in sporadic breast cancer.

Conclusions

In conclusion, this is the first study to describe VDR, RXR and PPARγ in BRCA1 mutated breast cancer. Based on the data presented here these receptors may be hypothesized to potentially evolve as interesting markers or even targets in hereditary breast cancer. However, independent studies are indispensable thus to confirm this hypothesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0517-1) contains supplementary material, which is available to authorized users.

Targeting HSP90-HDAC6 Regulating Network Implicates Precision Treatment of Breast Cancer

Breast cancer is the leading cause of women death. Heat shock protein 90 (HSP90) and Histone deacetylase 6 (HDAC6) are promising anti-cancer drug targets. However, it's still unclear the applicability of anti-HSP90 and anti-HDAC6 strategies in precision treatment of breast cancer. In current study, we found that triple negative breast cancer (TNBC) cells, compared to T47D, an ERα+ breast cancer cell line, exhibited 7~40 times lower IC₅₀ values, stronger cell cycle perturbation, increased cell apoptosis and stronger inhibition of cell migration upon 17-DMAG treatment, while T47D, compared to TNBC cells, expressed higher HDAC6 and showed stronger anti-cancer response upon treatment of Tubacin. Mechanically, 17-DMAG treatment inhibited a complex network consists at least ERK, AKT, and Hippo pathway in TNBC cells, and higher expression of HDAC6 inhibited HSP90 activity via deacetylating HSP90. Furthermore, we found higher HDAC6 expression level in tamoxifen-resistance T47D than that in T47D, and Tubacin treatment suppressed the growth of tamoxifen-resistant cells in vivo. Our data suggested that anti-HSP90 and anti-HDAC6 are promising strategies to treat TNBC and ERα+ breast cancers respectively, and anti-HDAC6 can be considered during treatment of tamoxifen-resistance breast cancers.

Kaiso depletion attenuates the growth and survival of triple negative breast cancer cells

Triple negative breast cancers (TNBC) are highly aggressive and lack specific targeted therapies. Recent studies have reported high expression of the transcription factor Kaiso in triple negative tumors, and this correlates with their increased aggressiveness. However, little is known about the clinical relevance of Kaiso in the growth and survival of TNBCs. Herein, we report that Kaiso depletion attenuates TNBC cell proliferation, and delays tumor onset in mice xenografted with the aggressive MDA-231 breast tumor cells. We further demonstrate that Kaiso depletion attenuates the survival of TNBC cells and increases their propensity for apoptotic-mediated cell death. Notably, Kaiso depletion downregulates BRCA1 expression in TNBC cells expressing mutant-p53 and we found that high Kaiso and BRCA1 expression correlates with a poor overall survival in breast cancer patients. Collectively, our findings reveal a role for Kaiso in the proliferation and survival of TNBC cells, and suggest a relevant role for Kaiso in the prognosis and treatment of TNBCs.

MT4-MMP and EGFR expression levels are key biomarkers for breast cancer patient response to chemotherapy and erlotinib

Background:

Triple-negative breast cancers (TNBC) are heterogeneous cancers with poor prognosis. We aimed to determine the clinical relevance of membrane type-4 matrix metalloproteinase (MT4-MMP), a membrane type matrix metalloproteinase that interacts with epidermal growth factor receptor (EGFR) overexpressed in >50% of TNBC.

Methods:

We conducted a retrospective immunohistochemical analysis on human TNBC samples (n=81) and validated our findings in in vitro and in vivo assays.

Results:

Membrane type-4 matrix metalloproteinase and EGFR are produced in 72.5% of TNBC samples, whereas those proteins are faintly produced by healthy tissues. Unexpectedly, tumour relapse after chemotherapy was reduced in samples highly positive for MT4-MMP. Mechanistically, this is ascribed to a higher sensitivity of MT4-MMP-producing cells to alkylating or intercalating chemotherapeutic agents, as assessed in vitro. In sharp contrast, MT4-MMP expression did not affect tumour cell sensitivity to paclitaxel that interferes with protease trafficking. Importantly, MT4-MMP expression sensitised cancer cells to erlotinib, a tyrosine kinase EGFR inhibitor. In a pre-clinical model, the growth of MT4-MMP overexpressing xenografts, but not of control ones, was reduced by epirubicin or erlotinib. The combination of suboptimal drug doses blocked drastically the growth of MT4-MMP-producing tumours.

Conclusions:

We demonstrate that MT4-MMP defines a sub-population of TNBC sensitive to a combination of DNA-targeting chemotherapeutic agents and anti-EGFR drugs.

Triple-negative breast cancer: is there a treatment on the horizon?

Triple-negative breast cancer (TNBC), which accounts for 15-20% of all breast cancers, does not express estrogen receptor (ER) or progesterone receptor (PR) and lacks human epidermal growth factor receptor 2 (HER2) overexpression or amplification. These tumors have a more aggressive phenotype and a poorer prognosis due to the high propensity for metastatic progression and absence of specific targeted treatments. Patients with TNBC do not benefit from hormonal or trastuzumab-based targeted therapies because of the loss of target receptors. Although these patients respond to chemotherapeutic agents such as taxanes and anthracyclines better than other subtypes of breast cancer, prognosis remains poor. A group of targeted therapies under investigation showed favorable results in TNBC, especially in cancers with BRCA mutation. The lipid-lowering statins (3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors), including lovastatin and simvastatin, have been shown to preferentially target TNBC compared with non-TNBC. These statins hold great promise for the management of TNBC. Only with the understanding of the molecular basis for the preference of statins for TNBC and more investigations in clinical trials can they be reformulated into a clinically approved drug against TNBC.