HER2-targeted therapy in breast cancer. Monoclonal antibodies and tyrosine kinase inhibitors

Surfactant-based drug delivery systems for cancer therapy: Advances, challenges, and future perspectives

Cancer is one of the most formidable global health challenges, needing ongoing progress in therapeutic approaches. Conventional cancer treatments, such as chemotherapy, frequently suffer from low solubility, systemic toxicity, and a lack of tailored drug delivery, resulting in unwanted side effects and limited efficacy. Surfactant-based drug delivery systems have emerged as a viable method for increasing drug solubility, stability, and tailored transport to tumor locations. Surfactants, due to their amphiphilic character, play an important role in the development of various drug delivery systems, such as micelles, liposomes, nanoemulsions, and lipid-based nanoparticles, which improve drug bioavailability and therapeutic index. This article looks at the fundamental role of surfactants in drug administration, including their classification (ionic, nonionic, amphoteric, and zwitterionic) and self-assembly behavior in the formation of micellar, vesicular, and emulsified nanocarriers. Various surfactant-based drug delivery platforms in oncology are explored, including polymeric and surfactant-stabilized micelles, liposomes (e.g., Doxil), nanoemulsions, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs). Furthermore, the use of surfactant-metal complexes in cancer therapy is emphasized because of their potential to improve therapeutic activity and selectivity. The review also looks at surfactant-enhanced drug targeting strategies, such as passive targeting using the enhanced permeability and retention (EPR) effect, active targeting with ligand-functionalized surfactant-based carriers, and stimuli-responsive systems designed for controlled drug release in the tumor microenvironment. Surfactant-based drug delivery advancements are explored, with an emphasis on current advances such as biodegradable and bio-inspired surfactants, combination therapies using surfactant-stabilized carriers, and AI-driven drug formulation techniques. Despite its potential, surfactant-based drug delivery systems confront several hurdles, including biocompatibility concerns, synthetic surfactant toxicity, stability issues, and scaling restrictions in pharmaceutical manufacture. Furthermore, regulatory barriers in clinical translation remain severe. Addressing these problems with innovative surfactant formulations, green chemical techniques, and sophisticated nanotechnological alterations will be critical to optimizing these systems for clinical use. This review provides a comprehensive analysis of the progress, challenges, and future perspectives of surfactant-based drug delivery systems in cancer therapy, highlighting their potential to revolutionize oncology treatments by improving drug efficacy, reducing systemic toxicity, and enabling precision medicine.

Proteolysis Targeting Chimeras (PROTACs) in Breast Cancer Therapy

Breast cancer (BC) accounts for 30 % of cancer cases among women cancer patients globally, indicating the urgent need for the development of selective therapies targeting BCs. Recently, proteolysis-targeting chimera (PROTAC) has emerged as a promising strategy to target breast cancer. PROTAC is a chimeric molecule consisting of a target protein ligand, an E3 ligase ligand, and conjugating linkers, enabling it to facilitate the degradation of desired target proteins by recruiting E3 ligase in close proximity. Due to the catalytic behavior and direct degradation of BC-causing proteins, PROTAC could achieve high drug efficacy with low doses, drawing great attention for its potential as therapeutics. This review provides cases of the currently developed PROTACs targeting BCs depending on the type of BCs, limitations, and future perspectives of PROTAC in targeting BCs.

A review on tyrosine kinase inhibitors for targeted breast cancer therapy

Breast cancer is a heterogeneous disease with complex molecular pathogenesis. Overexpression of several tyrosine kinase receptors is associated with poor prognosis, therefore, they can be key targets in breast cancer therapy. Tyrosine kinase inhibitors (TKIs) have emerged as leading agents in targeted cancer therapy due to their effectiveness in disrupting key molecular pathways involved in tumor growth. TKIs target various tyrosine kinases, including the human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), Vascular endothelial growth factor receptor (VEGFR), anaplastic lymphoma kinase (ALK), vascular endothelial growth factor receptor (VEGFR)-associated multi-targets, rearranged during transfection (RET), fibroblast growth factor receptor (FGFR), receptor tyrosine kinase-like orphan signal 1 (ROS1), Mitogen-activated protein kinase (MAPK), and tropomyosin receptor kinase (TRK). These drugs target the tyrosine kinase domain of receptor tyrosine kinases and play a vital role in proliferation and migration of breast cancer cells. Several TKIs, including lapatinib, neratinib, and tucatinib, have been developed and are currently used in clinical settings, often in combination with chemotherapy, endocrine therapy, or other targeted agents. TKIs have demonstrated remarkable benefits in enhancing progression-free and overall survival in patients with breast cancer and have become a standard of care for this population. This review provides an overview of TKIs currently being examined in preclinical studies and clinical trials, especially in combination with drugs approved for breast cancer treatment. TKIs have emerged as a promising therapeutic option for patients with breast cancer and hold potential for treating other breast cancer subtypes. The development of new TKIs and their integration into personalized treatment strategies will continue to shape the future of breast cancer therapy.

Efficacy and Safety of Neoadjuvant Pyrotinib for Human Epidermal Receptor 2-Positive Breast Cancer: A Meta-Analysis

Neoadjuvant pyrotinib shows the potential to improve treatment response in human epidermal receptor 2 (HER2)-positive breast cancer patients, but relevant meta-analyses are scarce. This meta-analysis intended to explore the efficacy and safety of neoadjuvant pyrotinib for HER2-positive breast cancer patients. Studies comparing the efficacy and safety between HER2-positive breast cancer patients receiving pyrotinib-containing neoadjuvant treatment (pyrotinib group) and those receiving other neoadjuvant treatments (control group), were searched in EMBASE, Web of Science, Cochrane, PubMed, China National Knowledge Infrastructure, Wanfang, and SinoMed until December 2023. Six randomized controlled trials (RCTs) and 4 cohort studies were included. The pyrotinib group and control group contained 540 and 684 patients, respectively. Pathological complete response (pCR) was higher in the pyrotinib group than in the control group [relative risk (RR)=1.93; 95% confidence interval (CI) = 1.63-2.29; P < 0.001]. Similar results were discovered in subgroup analyses of RCTs (RR = 1.89; 95% CI = 1.49-2.40; P < 0.001) and cohort studies (RR = 1.98; 95% CI = 1.55-2.53; P < 0.001). The objective response rate (ORR) was also higher in the pyrotinib group than in the control group (RR = 1.14; 95% CI = 1.07-1.21; P < 0.001). Regarding adverse events, only the incidence of diarrhea was increased in the pyrotinib group versus the control group (RR = 1.97; 95% CI = 1.31-2.96; P = 0.001), while others were not different, including nausea and vomiting, leukopenia, thrombocytopenia, hand-foot syndrome, and alopecia (all P > 0.05). No publication bias existed, and sensitivity analysis suggested the satisfactory robustness of this meta-analysis. In conclusion, compared with other neoadjuvant treatments, pyrotinib-containing neoadjuvant treatment achieves a better treatment response with a good safety profile in HER2-positive breast cancer patients.

Cancer treatment with biosimilar drugs: A review

Biosimilars are biological drugs created from living organisms or that contain living components. They share an identical amino-acid sequence and immunogenicity. These drugs are considered to be cost-effective and are utilized in the treatment of cancer and other endocrine disorders. The primary aim of biosimilars is to predict biosimilarity, efficacy, and treatment costs; they are approved by the Food and Drug Administration (FDA) and have no clinical implications. They involve analytical studies to understand the similarities and dissimilarities. A biosimilar manufacturer sets up FDA-approved reference products to evaluate biosimilarity. The contribution of next-generation sequencing is evolving to study the organ tumor and its progression with its impactful therapeutic approach on cancer patients to showcase and target rare mutations. The study shall help to understand the future perspectives of biosimilars for use in gastro-entero-logic diseases, colorectal cancer, and thyroid cancer. They also help target specific organs with essential mutational categories and drug prototypes in clinical practices with blood and liquid biopsy, cell treatment, gene therapy, recombinant therapeutic proteins, and personalized medications. Biosimilar derivatives such as monoclonal antibodies like trastuzumab and rituximab are common drugs used in cancer therapy. Escherichia coli produces more than six antibodies or antibody-derived proteins to treat cancer such as filgrastim, epoetin alfa, and so on.

Monoclonal Antibodies and Antibody-drug Conjugates as Emerging Therapeutics for Breast Cancer Treatment

When breast cells divide and multiply out of control, it is called breast cancer. Symptoms include lump formation in the breast, a change in the texture or color of the breast, or a discharge from the nipple. Local or systemic therapy is frequently used to treat breast cancer. Surgical and radiation procedures limited to the affected area are examples of local management. There has been significant worldwide progress in the development of monoclonal antibodies (mAbs) since 1986, when the first therapeutic mAb, Orthoclone OKT3, became commercially available. mAbs can resist the expansion of cancer cells by inducing the destruction of cellular membranes, blocking immune system inhibitors, and preventing the formation of new blood vessels. mAbs can also target growth factor receptors. Understanding the molecular pathways involved in tumor growth and its microenvironment is crucial for developing effective targeted cancer therapeutics. Due to their unique properties, mAbs have a wide range of clinical applications. Antibody-drug conjugates (ADCs) are drugs that improve the therapeutic index by combining an antigen-specific antibody with a payload. This review focuses on the therapeutic applications, mechanistic insights, characteristics, safety aspects, and adverse events of mAbs like trastuzumab, bevacizumab, pertuzumab, ertumaxomab, and atezolizumab in breast cancer treatment. The creation of novel technologies utilizing modified antibodies, such as fragments, conjugates, and multi-specific antibodies, must be a central focus of future studies. This review will help scientists working on developing mAbs to treat cancers more effectively.

Clinical perspective: Antibody-drug conjugates for the treatment of HER2-positive breast cancer

Antibody-drug conjugates (ADCs) are a promising class of cancer biopharmaceuticals that exploit the specificity of a monoclonal antibody (mAb) to selectively deliver highly cytotoxic small molecules to targeted cancer cells, leading to an enhanced therapeutic index through increased antitumor activity and decreased off-target toxicity. ADCs hold great promise for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer after the approval and tremendous success of trastuzumab emtansine and trastuzumab deruxtecan, representing a turning point in both HER2-positive breast cancer treatment and ADC technology. Additionally and importantly, a total of 29 ADC candidates are now being investigated in different stages of clinical development for the treatment of HER2-positive breast cancer. The purpose of this review is to provide an insight into the ADC field in cancer treatment and present a comprehensive overview of ADCs approved or under clinical investigation for the treatment of HER2-positive breast cancer.

Quercetin modulates signal transductions and targets non-coding RNAs against cancer development

In recent decades, various investigations have indicated that natural compounds have great potential in the prevention and treatment of different chronic disorders including different types of cancer. As a bioactive flavonoid, Quercetin (Qu) is a dietary ingredient enjoying high pharmacological values and health-promoting effects due to its antioxidant and anti-inflammatory characterization. Conclusive in vitro and in vivo evidence has revealed that Qu has great potential in cancer prevention and development. Qu exerts its anticancer influences by altering various cellular processes such as apoptosis, autophagy, angiogenesis, metastasis, cell cycle, and proliferation. In this way, Qu by targeting numerous signaling pathways as well as non-coding RNAs regulates several cellular mechanisms to suppress cancer occurrence and promotion. This review aimed to summarize the impact of Qu on the molecular pathways and non-coding RNAs in modulating various cancer-associated cellular mechanisms.

Preclinical safety assessment of MV-s-NAP, a novel oncolytic measles virus strain armed with an H . pylori immunostimulatory bacterial transgene

Despite recent therapeutic advances, metastatic breast cancer (MBC) remains incurable. Engineered measles virus (MV) constructs based on the attenuated MV Edmonston vaccine platform have demonstrated significant oncolytic activity against solid tumors. The Helicobacter pylori neutrophil-activating protein (NAP) is responsible for the robust inflammatory reaction in gastroduodenal mucosa during bacterial infection. NAP attracts and activates immune cells at the site of infection, inducing expression of pro-inflammatory mediators. We engineered an MV strain to express the secretory form of NAP (MV-s-NAP) and showed that it exhibits anti-tumor and immunostimulatory activity in human breast cancer xenograft models. In this study, we utilized a measles-infection-permissive mouse model (transgenic IFNAR KO-CD46Ge) to evaluate the biodistribution and safety of MV-s-NAP. The primary objective was to identify potential toxic side effects and confirm the safety of the proposed clinical doses of MV-s-NAP prior to a phase I clinical trial of intratumoral administration of MV-s-NAP in patients with MBC. Both subcutaneous delivery (corresponding to the clinical trial intratumoral administration route) and intravenous (worst case scenario) delivery of MV-s-NAP were well tolerated: no significant clinical, laboratory or histologic toxicity was observed. This outcome supports the safety of MV-s-NAP for oncolytic virotherapy of MBC. The first-in-human clinical trial of MV-s-NAP in patients with MBC (ClinicalTrials.gov: NCT04521764) was subsequently activated.

Molecular perspective on targeted therapy in breast cancer: a review of current status

Breast cancer is categorized at the molecular level according to the status of certain hormone and growth factor receptors, and this classification forms the basis of current diagnosis and treatment. The development of resistance to treatment and recurrence of the disease have led researchers to develop new therapies. In recent years, most of the research in the field of oncology has focused on the development of targeted therapies, which are treatment methods developed directly against molecular abnormalities. Promising advances have been made in clinical trials investigating the effect of these new treatment modalities and their combinations with existing therapeutic treatments in the treatment of breast cancer. Monoclonal antibodies, tyrosine kinase inhibitors, antibody–drug conjugates, PI3K/Akt/mTOR pathway inhibitors, cyclin-dependent kinase 4/6 inhibitors, anti-angiogenic drugs, PARP inhibitors are among the targeted therapies used in breast cancer treatment. In this review, we aim to present a molecular view of recently approved target agents used in breast cancer.

Ensemble of nucleic acid absolute quantitation modules for copy number variation detection and RNA profiling

Current gold standard for absolute quantitation of a specific DNA sequence is droplet digital PCR (ddPCR), which has been applied to copy number variation (CNV) detection. However, the number of quantitation modules in ddPCR is limited by fluorescence channels, which thus limits the CNV sensitivity due to sampling error following Poisson distribution. Here we develop a PCR-based molecular barcoding NGS approach, quantitative amplicon sequencing (QASeq), for accurate absolute quantitation scalable to over 200 quantitation modules. By attaching barcodes to individual target molecules with high efficiency, 2-plex QASeq exhibits higher and more consistent conversion yield than ddPCR in absolute molecule count quantitation. Multiplexed QASeq improves CNV sensitivity allowing confident distinguishment of 2.05 ploidy from normal 2.00 ploidy. We apply multiplexed QASeq to serial longitudinal plasma cfDNA samples from patients with metastatic ERBB2+ (HER2+ ) breast cancer seeking association with tumor progression. We further show an RNA QASeq panel for targeted expression profiling.

Recent advances in nanoscale targeted therapy of HER2-positive breast cancer

Breast cancer is the second leading cause of death among women with high mortality rates worldwide. The exceptionally fast rate of metastasis, the emergence of drug-resistant mechanisms, and the occurrence of inadvertent side effects by cytotoxic chemotherapies often make conventional chemotherapy and immunotherapy treatments ineffective. Similar to other solid tumors, breast cancer can develop unique cellular and molecular characteristics forming an atypical permissive tumor microenvironment (TME). Due to the unique features of TME, cancer cells can further proliferate and coadapt with the stromal cells and evade immunosurveillance. aberrantly abundantly express various pieces of molecular machinery (the so-called oncomarkers) in favor of their survival, progression, metastasis, and further invasion. Such overexpressed oncomarkers can be exploited in the targeted therapy of cancer. Among breast cancer oncomarkers, epidermal growth factor receptors, particularly HER2, are considered as clinically valid molecular targets not only for the thorough diagnosis but also for the targeted therapy of the disease using different conventional and advanced nanoscale treatment modalities. This review aims to elaborate on the recent advances in the targeted therapy of HER2-positive breast cancer, and discuss various types of multifunctional nanomedicines/theranostics, and antibody-/aptamer-drug conjugates.

Carboxylated chitosan-mediated improved efficacy of mesoporous silica nanoparticle-based targeted drug delivery system for breast cancer therapy

Nanoparticle-based targeting of overexpressed cell-surface receptors is a promising strategy that provides precise delivery of drugs to cancer cells. In the present study, we developed highly reproducible and monodispersed, chitosan-coated (pH-responsive), doxorubicin-loaded, aptamer-mesoporous silica nanoparticle (MSN) bioconjugates for actively targeting breast cancer cells harboring overexpression of EGF receptors (EGFR/HER2). The developed targeted MSNs demonstrated higher uptake and cytotoxicity of triple negative and HER2 positive breast cancer cells when compared to non-targeted MSNs. The chitosan coating imparted pH-responsiveness and endo/lysosomal escape ability to MSNs, which augmented cytosolic delivery of an anticancer drug. Partial carboxylation of chitosan coated on MSNs allowed for a greater release of drug in a shorter duration of time while retaining pH-responsiveness and endo/lysosomal escape ability. Overall, the coating of carboxylated-chitosan over MSNs enabled tunable drug release kinetics, conjugation of aptamers (targeting agents), and endo/lysosomal escape which together significantly enhanced the efficacy of the developed drug delivery system.

Preclinical evaluation of MRG002, a novel HER2-targeting antibody-drug conjugate with potent antitumor activity against HER2-positive solid tumors

Background

ERBB2 is a proto-oncogene of multiple cancers including breast and gastric cancers with HER2 protein overexpression or gene amplification and has been proven clinically as a valid target for these cancers. HER2-targeting agents such as Herceptin®, Kadcyla® and ENHERTU® have been approved by the FDA for the treatment of breast cancer, but these drugs still face the challenge of acquired resistance and/or severe adverse reactions in clinical use. Therefore, there is significant unmet medical need for developing new agents that are more effective and safer for patients with advanced HER2-positive solid tumors including breast and gastric cancers.

Methods

We report here the making of MRG002, a novel HER2-targeted antibody drug conjugate (ADC), and preclinical characterization including pharmacology, pharmacodynamics and toxicology and discuss its potential as a novel agent for treating patients with HER2-positive solid tumors.

Results

MRG002 exhibited similar antigen binding affinity but much reduced antibody-dependent cellular cytotoxicity (ADCC) activity compared to trastuzumab. In addition to potent in vitro cytotoxicity, MRG002 showed tumor regression in both high- and medium-to-low HER2 expressing in vivo xenograft models. Furthermore, MRG002 showed enhanced antitumor activity when used in combination with an anti-PD-1 antibody. Main findings from toxicology studies are related to the payload and are consistent with literature report of other ADCs with monomethyl auristatinE.

Conclusion

MRG002 has demonstrated a favorable toxicity profile and potent antitumor activities in the breast and gastric PDX models with varying levels of HER2 expression, and/or resistance to trastuzumab or T-DM1. A phase I clinical study of MRG002 in patients with HER2-positive solid tumors is ongoing (CTR20181778).

Selenium inhibits growth of trastuzumab-resistant human breast cancer cells via downregulation of Akt and beclin-1

The response rate to treatment with trastuzumab (Tz), a recombinant humanized anti-HER2 monoclonal antibody, is only 12–34% despite demonstrated effectiveness on improving the survival of patients with HER2-positive breast cancers. Selenium has an antitumor effect against cancer cells and can play a cytoprotective role on normal cells. This study investigated the effect of selenium on HER2-positive breast cancer cells and the mechanism in relation to the response of the cells to Tz. HER2-positive breast cancer cell lines, SK-BR-3 as trastuzumab-sensitive cells, and JIMT-1 as Tz-resistant cells were treated with Tz and sodium selenite (selenite). Cell survival rates and expression of Her2, Akt, and autophagy-related proteins, including LC3B and beclin 1, in both cell lines 72 h after treatment were evaluated. Significant cell death was induced at different concentrations of selenite in both cell lines. A combined effect of selenite and Tz at 72 h was similar to or significantly greater than each drug alone. The expression of phosphorylated Akt (p-Akt) was decreased in JIMT-1 after combination treatment compared to that after only Tz treatment, while p-Akt expression was increased in SK-BR-3. The expression of beclin1 increased particularly in JIMT-1 after only Tz treatment and was downregulated by combination treatment. These results showed that combination of Tz and selenite had an antitumor effect in Tz-resistant breast cancer cells through downregulation of phosphorylated Akt and beclin1-related autophagy. Selenite might be a potent drug to treat Tz-resistant breast cancer by several mechanisms.

Pyrazole Substituted 9-Anilinoacridines as HER2 Inhibitors Targeting Breast Cancer - An In-Silico Approach

BACKGROUND

Breast cancer is one of the malignant tumours which mainly affect the female population. Total 20% of the cases of breast cancer are due to overexpression of Human epidermal growth factor receptor-2 (HER2), which is the dominant tyrosine kinase receptor. In general, 9-anilinoacridine derivatives play an important role as antitumor agents due to their DNA-intercalating properties.

OBJECTIVE

Some novel 9-anilinoacridines substituted with pyrazole moiety(1a-z) were designed, and their HER2enzyme (PDB id-3PP0) inhibition activity was evaluated by molecular docking studies using the Glide module of Schrodinger suite 2019-4.

METHODS

Glide module of the Schrodinger suite was used to perform docking studies, qikprop module was used for in-silico ADMET screening, and the Prime-MM-GBSA module was used for free binding energy calculations. Using GLIDE scoring functions, we can determine the binding affinity of ligands (1a-z) towards HER2.

RESULTS

The inhibitory activity of ligands against HER2 was mainly due to the strong hydrophobic and hydrogen bonding interactions. Almost all the compounds 1a-z have a good binding affinity with Glide scores in the range of -4.9 to -9.75 compared to the standard drugs CK0403(-4.105) and Tamoxifen (-3.78). From the results of in-silico ADMET properties, most of the compounds fall within the recommended values. MM-GBSA binding calculations of the most potent inhibitors are more favourable.

CONCLUSION

The results of in-silico studies provide strong evidence for the consideration of valuable ligands in pyrazole substituted 9-anilinoacridines as potential HER2 inhibitors, and the compounds, 1v,s,r,d, a,o with significant Glide scores may produce significant anti-breast cancer activity for further development.

Prevalence of HER2 overexpression and amplification in squamous cell carcinoma of the esophagus: A systematic review and meta-analysis

Accurate data on HER2 positivity in esophageal squamous cell carcinoma patients (ESCC) is lacking. We conducted a systematic review and meta-analysis (Single Incidence Rates; metarate package, R) to examine the prevalence of HER2 in ESCC. Data on in situ hybridization (ISH) and immunohistochemistry (IHC) were extracted to derive pooled prevalence estimates, characteristics of the studies were extracted for subgroup analysis. Eighteen studies with 1505 patients were identified. HER2 gene amplification by ISH were prevalent in 10 % (95 % CI 6.9 %-15 %). Prevalence of HER2 overexpression (IHC3+) and borderline HER2 expression (IHC2+) were 6 % (95 % CI: 3.5 %-8.7 %) and 10 % (95 % CI: 6.0 %-17 %), respectively. An estimated 8.6 % (95 % CI: 5.5 %-13 %) of ESCC were HER2 positive using initial IHC followed by reflex ISH confirmation of borderline HER2 expression. In conclusion: Estimated prevalence of HER 2 positivity in ESCC were 10 % assessed by ISH and 8.6 % assessed by initial IHC followed by ISH.

A sensitivity scale for targeting T cells with chimeric antigen receptors (CARs) and bispecific T-cell Engagers (BiTEs)

Although T cells can mediate potent antitumor responses, immune tolerance mechanisms often result in the deletion or inactivation of T cells that express T-cell receptors (TCRs) against potentially effective target epitopes. Various approaches have been devised to circumvent this problem. In one approach, the gene encoding an antibody against a cancer-associated antigen is linked, in the form of a single-chain variable fragment (scFv), to genes that encode transmembrane and signaling domains. This chimeric antigen receptor (CAR) is then introduced into T cells for adoptive T-cell therapy. In another approach, the anti-cancer scFv is fused to a scFv that binds to the CD3ε subunit of the TCR/CD3 complex. This fusion protein serves as a soluble, injectable product that has recently been termed bispecific T-cell engager (BiTE). Both strategies have now been tested in clinical trials with promising results, but the comparative efficacies are not known. Here, we performed a direct comparison of the in vitro sensitivity of each strategy, using the same anti-cancer scFv fragments, directed against a tumor-specific glycopeptide epitope on the sialomucin-like transmembrane glycoprotein OTS8, which results form a cancer-specific mutation of Cosmc. While both approaches showed specific responses to the epitope as revealed by T cell-mediated cytokine release and target cell lysis, CAR-targeted T cells were more sensitive than BiTE-targeted T cells to low numbers of antigens per cell. The sensitivity scale described here provides a guide to the potential use of these two different approaches.

Tumor-associated neutrophils as new players in immunosuppressive process of the tumor microenvironment in breast cancer

Despite the conventional reputation of neutrophils to have antibacterial properties, recent studies have put emphasis and are interested in the role of neutrophils in the spread and treatment of cancer. It has been shown that the infiltration of neutrophils, either by exerting pro- or anti-tumoral effects, probably affects tumor prognosis. Tumor-associated neutrophils (TANs) probably participate in tumor promotion and development in different ways, such as increasing genomic instability, induction of immunosuppression, and increasing angiogenesis. Despite major advances in breast cancer treatment, it is the second leading cause of death in American women. It has been revealed that inflammation is a fundamental issue in the treatment of this cancer because tumor growth, invasion, metastasis, and vascularization can be affected by inflammatory factors. It is demonstrated that enhanced neutrophil to lymphocyte ratio probably contributes to the raised rate of mortality and decreased survival among breast cancer cases. The present review explores the biology of TANs, their suspected interactions in the breast cancer microenvironment, and their functions in preserving the tumor microenvironment and progression of tumors. Furthermore, their potential as therapeutic targets and clinical biomarkers has been discussed in this paper.

Prolidase - A protein with many faces

Prolidase is a metal-dependent peptidase specialized in the cleavage of dipeptides containing proline or hydroxyproline on their C-termini. Prolidase homologues are found in all kingdoms of life. The importance of prolidase in human health is underlined by a rare hereditary syndrome referred to as Prolidase Deficiency. A growing number of studies highlight the importance of prolidase in various other human conditions, including cancer. Some recent studies link prolidase's activity-independent regulatory role to tumorigenesis. Furthermore, the enzyme or engineered variants have some applications in biotechnology. In this short review, we aim to highlight different aspects of the protein the importance of which is increasingly recognized over the last years.

Specific targeting of HER2-positive human breast carcinoma SK-BR-3 cells by amygdaline-ZHER2 affibody conjugate

Amygdalin induces apoptotic death in several carcinoma cells. Affibody is an engineered protein with a high affinity for human epidermal receptor 2 (HER2). We assessed the cytotoxic effects of the amygdalin-Z_HER2 affibody conjugate on two breast carcinoma cell lines. The Z_HER2 affibody gene was synthesized and transferred into E. coli BL21 as an expression host. After purification, the Z_HER2 affibody was conjugated to amygdalin. The cytotoxic effects of amygdalin and its Z_HER2 affibody conjugate on the SK-BR-3, with overexpression of HER2, and MCF-7 cells were evaluated by MTT assay. The effects of amygdalin and its conjugate on apoptotic death and expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were measured. Amygdalin individually showed a potent cytotoxic effect against both MCF-7 (IC₅₀ = 14.2 mg ml^-1) and SK-BR-3 cells (IC₅₀ = 13.7 mg ml^-1). However, the amygdalin-Z_HER2 affibody conjugate had a more cytotoxic effect on SK-BR-3 (IC₅₀ = 8.27 mg ml^-1) than MCF-7 cells (IC₅₀ = 19.8 mg ml^-1). Amygdalin had a significant apoptotic effect on both cell lines and the effect of its conjugate on SK-BR-3 cells was significantly more potent than MCF-7 cells. Amygdalin increased Bax and decreased Bcl-2 expression in both cell lines. However, the effect of its conjugate on the Bax and Bcl-2 expression in SK-BR-3 was more potent than MCF-7 cells. In conclusion, the amygdalin-Z_HER2 affibody conjugate may be considered as a valuable candidate for specific treatment of breast cancer patients with overexpression of HER2. However, further in vivo studies are required to explain the antitumoral effects of constructed amygdalin-Z_HER2 affibody conjugate.

MicroRNA-33b Suppresses Epithelial-Mesenchymal Transition Repressing the MYC-EZH2 Pathway in HER2+ Breast Carcinoma

Downregulation of miR-33b has been documented in many types of cancers and is being involved in proliferation, migration, and epithelial–mesenchymal transition (EMT). Furthermore, the enhancer of zeste homolog 2-gene (EZH2) is a master regulator of controlling the stem cell differentiation and the cell proliferation processes. We aim to evaluate the implication of miR-33b in the EMT pathway in HER2+ breast cancer (BC) and to analyze the role of EZH2 in this process as well as the interaction between them. miR-33b is downregulated in HER2+ BC cells vs healthy controls, where EZH2 has an opposite expression in vitro and in patients’ samples. The upregulation of miR-33b suppressed proliferation, induced apoptosis, reduced invasion, migration and regulated EMT by an increase of E-cadherin and a decrease of ß-catenin and vimentin. The silencing of EZH2 mimicked the impact of miR-33b overexpression. Furthermore, the inhibition of miR-33b induces cell proliferation, invasion, migration, EMT, and EZH2 expression in non-tumorigenic cells. Importantly, the Kaplan–Meier analysis showed a significant association between high miR-33b expression and better overall survival. These results suggest miR-33b as a suppressive miRNA that could inhibit tumor metastasis and invasion in HER2+ BC partly by impeding EMT through the repression of the MYC–EZH2 loop.

HER2 biosensing through SPR-envelope tracking in plasmonic optical fiber gratings

In the biomedical detection context, plasmonic tilted fiber Bragg gratings (TFBGs) have been demonstrated to be a very accurate and sensitive sensing tool, especially well-adapted for biochemical detection. In this work, we have developed an aptasensor following a triple strategy to improve the overall sensing performances and robustness. Single polarization fiber (SPF) is used as biosensor substrate while the demodulation is based on tracking a peculiar feature of the lower envelope of the cladding mode resonances spectrum. This method is highly sensitive and yields wavelength shifts several tens of times higher than the ones reported so far based on the tracking of individual modes of the spectrum. An amplification of the response is further performed through a sandwich assay by the use of specific antibodies. These improvements have been achieved on a biosensor developed for the detection of the HER2 (Human Epidermal Growth Factor Receptor-2) protein, a relevant breast cancer biomarker. These advanced developments can be very interesting for point-of-care biomedical measurements in a convenient practical way.

HER2 breast cancer biomarker detection using a sandwich optical fiber assay

Optical fiber-based surface plasmon resonance (OF-SPR) sensors have demonstrated high versatility and performances over the last years, which propelled the technique to the heart of numerous and original biosensing concepts. In this work, we contribute to this effort and present our recent findings about the detection of breast cancer HER2 biomarkers through OF-SPR optrodes. 1 cm-long sections of 400 μm core-diameter optical fibers were covered with a sputtered gold film, yielding enhanced sensitivity to surface refractive index changes. Studying the impacts of the gold film thickness on the plasmonic spectral response, we improved the quality and reproducibility of the sensors. These achievements were correlated in two ways, using both the central wavelengths of the plasmon resonance and its influence on the bulk refractive index sensitivity. Our dataset was fed by additional biosensing experiments with a direct and indirect approach, relying on aptamers and antibodies specifically implemented in a sandwich layout. HER2 biomarkers were specifically detected at 0.6 μg/mL (5.16 nM) in label-free while the amplification with HER2-antibodies provided a nearly hundredfold signal magnification, reaching 9.3 ng/mL (77.4 pM). We believe that these results harbinger the way for their further use in biomedical samples.

Immunohistochemical index prediction of breast tumor based on multi-dimension features in contrast-enhanced ultrasound

Breast cancer is the leading killer of Chinese women. Immunohistochemistry index has great significance in the treatment strategy selection and prognosis analysis for breast cancer patients. Currently, histopathological examination of the tumor tissue through surgical biopsy is the gold standard to determine immunohistochemistry index. However, this examination is invasive and commonly causes discomfort in patients. There has been a lack of noninvasive method capable of predicting immunohistochemistry index for breast cancer patients. This paper proposes a machine learning method to predict the immunohistochemical index of breast cancer patients by using noninvasive contrast-enhanced ultrasound. A total of 119 breast cancer patients were included in this retrospective study. Each patient implemented the pathological examination of immunohistochemical expression and underwent contrast-enhanced ultrasound imaging of breast tumor. The multi-dimension features including 266 three-dimension features and 837 two-dimension dynamic features were extracted from the contrast-enhanced ultrasound sequences. Using the machine learning prediction method, 21 selected multi-dimension features were integrated to generate a model for predicting the immunohistochemistry index noninvasively. The immunohistochemical index of human epidermal growth factor receptor-2 (HER2) was predicted based on multi-dimension features in contrast-enhanced ultrasound sequence with the sensitivity of 71%, and the specificity of 79% in the testing cohort. Therefore, the noninvasive contrast-enhanced ultrasound can be used to predict the immunohistochemical index. To our best knowledge, no studies have been reported about predicting immunohistochemical index by using contrast-enhanced ultrasound sequences for breast cancer patients. Our proposed method is noninvasive and can predict immunohistochemical index by using contrast-enhanced ultrasound in several minutes, instead of relying totally on the invasive and biopsy-based histopathological examination. Graphical abstract Immunohistochemical index prediction of breast tumor based on multi-dimension features in contrast-enhanced ultrasound.

Evaluation of HER2 expression in urothelial carcinoma cells as a biomarker for circulating tumor cells

BACKGROUND

Detection of circulating tumor cells (CTC) by techniques based on epithelial cell adhesion molecule (EpCAM) is suboptimal in urothelial carcinoma (UC). As HER2 is thought to be broadly expressed in UC, we explored its utility for CTC detection.

METHODS

HER2 and EpCAM expression was analyzed in 18 UC cell lines (UCCs) by qRT-PCR, western blot and fluorescence-activated cell scanning (FACS) and compared to the strongly HER2-expressing breast cancer cell line SKBR3 and other controls. HER2 expression in UC patient tissues was measured by qRT PCR and correlated with data on survival and risk for metastasis. UCCs with high EpCAM and variable HER2 expression were used for spike-in experiments in the CellSearch system. Twenty-one blood samples from 13 metastatic UC patients were analyzed for HER2-positive CTCs with CellSearch.

RESULTS

HER2 mRNA and protein were broadly expressed in UCC, with some heterogeneity, but at least 10-fold lower than in the HER-2+ SKBR3 cells. Variations were unrelated to cellular phenotype or clinicopathological characteristics. EpCAM expression was essentially restricted to UCCs with epitheloid phenotypes. Heterogeneity of EpCAM and HER2 expression was observed also in spike-in experiments. The 7 of 21 blood samples from 6 of 13 patients were enumerated as CTC positive via EpCAM, but only one sample stained weakly positive (1+) for HER2.

CONCLUSIONS

Detection rate of CTCs by EpCAM in UC is poor, even in metastatic patients. Because of its widespread expression, particularly in patients with high risk of metastasis, detection of HER2 could improve identification of UC CTCs, which is why combined detection using antibodies for EpCAM and HER2 may be beneficial.

Development of anti-HER2-targeted doxorubicin-core-shell chitosan nanoparticles for the treatment of human breast cancer

Purpose: Doxorubicin (DOX) encapsulated O-succinyl chitosan graft Pluronic^® F127 (OCP) copolymer nanoparticles conjugated with an anti-HER2 monoclonal antibody were developed as targeted drug delivery vehicles for the treatment of HER2-overexpressing breast cancer.

Methods: Five percent and 10% (w/w) of O-succinyl chitosan was grafted onto Pluronic^® F127 using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as mediated cross-linking agents. DOX was added to the copolymer solution to form DOX-nanoparticles before conjugation with anti-HER2 on the surface of the nanoparticles.

Results: DOX was encapsulated within the NP matrices at an encapsulation efficiency of 73.69 ± 0.53% to 74.65 ± 0.44% (the initial DOX concentration was 5 µg/mL). Anti-HER2 was successfully conjugated onto the surface of the nanoparticles at a moderately high conjugation efficiency of approximately 57.23 ± 0.38% to 61.20 ± 4.42%. In the in vitro DOX dissolution study, the nanoparticle formulations exhibited a biphasic drug release with an initial burst release followed by a sustained release profile at both pH 5.0 and pH 7.4. The drug was rapidly and completely released from the nanoparticles at pH 5.0. In the in vitro cytotoxicity, the anti-HER2 conjugated OCP copolymer nanoparticles showed the lowest IC₅₀, which indicated an increase in the therapeutic efficacy of DOX to treat human breast cancer cells with the HER2 overexpression.

Conclusion: Our study shows that anti-HER2 conjugated OCP copolymer nanoparticles have the potential for the development of anticancer drug carriers.

In-silico Design, ADMET Screening, MM-GBSA Binding Free Energy of Some Novel Isoxazole Substituted 9-Anilinoacridines as HER2 Inhibitors Targeting Breast Cancer

BACKGROUND

Human Epidermal development factor Receptor-2 (HER2) is a membrane tyrosine kinase which is overexpressed and gene amplified in human breast cancers. HER2 amplification and overexpression have been linked to important tumor cell proliferation and survival pathways for 20% of instances of breast cancer. 9-aminoacridines are significant DNA-intercalating agents because of their antiproliferative properties.

OBJECTIVE

Some novel isoxazole substituted 9-anilinoacridines(1a-z) were designed by in-silico technique for their HER2 inhibitory activity. Docking investigations of compounds 1a-z are performed against HER2 (PDB id-3PP0) by using Schrodinger suit 2016-2.

METHODS

Molecular docking study for the designed molecules 1a-z are performed by Glide module, in-silico ADMET screening by QikProp module and binding free energy by Prime-MMGBSA module of Schrodinger suit. The binding affinity of designed molecules 1a-z towards HER2 was chosen based on GLIDE score.

RESULTS

Many compounds showed good hydrophobic communications and hydrogen bonding associations to hinder HER2. The compounds 1a-z, aside from 1z have significant Glide scores in the scope of - 4.91 to - 10.59 when compared with the standard Ethacridine (- 4.23) and Tamoxifen (- 3.78). The in-silico ADMET properties are inside the suggested about drug likeness. MM-GBSA binding of the most intense inhibitor is positive.

CONCLUSION

The outcomes reveal that this study provides evidence for the consideration of isoxazole substituted 9-aminoacridine derivatives as potential HER2 inhibitors. The compounds, 1s,x,v,a,j,r with significant Glide scores may produce significant anti breast cancer activity and further in vitro and in vivo investigations may prove their therapeutic potential.

Therapeutic potency of oncolytic virotherapy in breast cancer targeting, current status and perspective

Breast cancer is the most common cause of cancer death in women and presents a serious therapeutic challenge worldwide. Traditional treatments are less successful at targeting cancer tumors, leading to recurrent treatment-resistant secondary malignancies. Oncolytic virotherapy (OV) is a novel anticancer strategy with therapeutic implications at targeting cancer cells by using mechanisms that differ from conventional therapies. Administration of OVs either alone or in combination with standard therapies provide new insights regarding the effectiveness and improvement of treatment responses for breast cancer patients. This review summarizes cellular, animal and clinical studies investigating therapeutic potency of oncolytic virotherapy in breast cancer treatment for a better understanding and hence a better management of this disease.

Interleukin-6 expression contributes to lapatinib resistance through maintenance of stemness property in HER2-positive breast cancer cells

Lapatinib is an inhibitor of human epidermal growth factor receptor 2 (HER2), which is overexpressed in 20-25% of breast cancers. Clinically, lapatinib has shown promising benefits for HER2-positive breast cancer patients; however, patients eventually acquire resistance, limiting its long-term use. In a previous study, we found that interleukin-6 (IL-6) production was increased in acquired lapatinib-resistant HER2-positive breast cancer cells. In the present study, we confirmed that lapatinib-resistant cells had elevated IL-6 expression and also maintained both stemness population and property. The increase in IL-6 was required for stemness property maintenance, which was mediated primarily through the activation of signal transducer and activator of transcription 3 (STAT3). Blocking IL-6 activity reduced spheroid formation, cell viability and subsequently overcame lapatinib resistance, whereas stimulation of IL-6 rendered parental cells more resistant to lapatinib-induced cytotoxicity. These results point to a novel mechanism underlying lapatinib resistance and provide a potential strategy to overcome resistance via IL-6 inhibition.

Risk Factors and Preventions of Breast Cancer

Breast cancer is the second leading cause of cancer deaths among women. The development of breast cancer is a multi-step process involving multiple cell types, and its prevention remains challenging in the world. Early diagnosis of breast cancer is one of the best approaches to prevent this disease. In some developed countries, the 5-year relative survival rate of breast cancer patients is above 80% due to early prevention. In the recent decade, great progress has been made in the understanding of breast cancer as well as in the development of preventative methods. The pathogenesis and tumor drug-resistant mechanisms are revealed by discovering breast cancer stem cells, and many genes are found related to breast cancer. Currently, people have more drug options for the chemoprevention of breast cancer, while biological prevention has been recently developed to improve patients' quality of life. In this review, we will summarize key studies of pathogenesis, related genes, risk factors and preventative methods on breast cancer over the past years. These findings represent a small step in the long fight against breast cancer.

Cell-specific biomarkers and targeted biopharmaceuticals for breast cancer treatment

Breast cancer is the second leading cause of cancer death among women, and its related treatment has been attracting significant attention over the past decades. Among the various treatments, targeted therapy has shown great promise as a precision treatment, by binding to cancer cell-specific biomarkers. So far, great achievements have been made in targeted therapy of breast cancer. In this review, we first discuss cell-specific biomarkers, which are not only useful for classification of breast cancer subtyping but also can be utilized as goals for targeted therapy. Then, the innovative and generic-targeted biopharmaceuticals for breast cancer, including monoclonal antibodies, non-antibody proteins and small molecule drugs, are reviewed. Finally, we provide our outlook on future developments of biopharmaceuticals, and provide solutions to problems in this field.

Emerging therapeutic targets in metastatic progression: A focus on breast cancer

Metastasis is the underlying cause of death for the majority of breast cancer patients. Despite significant advances in recent years in basic research and clinical development, therapies that specifically target metastatic breast cancer remain inadequate, and represents the single greatest obstacle to reducing mortality of late-stage breast cancer. Recent efforts have leveraged genomic analysis of breast cancer and molecular dissection of tumor-stromal cross-talk to uncover a number of promising candidates for targeted treatment of metastatic breast cancer. Rational combinations of therapeutic agents targeting tumor-intrinsic properties and microenvironmental components provide a promising strategy to develop precision treatments with higher specificity and less toxicity. In this review, we discuss the emerging therapeutic targets in breast cancer metastasis, from tumor-intrinsic pathways to those that involve the host tissue components, including the immune system.

Peptide-conjugated PEGylated PAMAM as a highly affinitive nanocarrier towards HER2-overexpressing cancer cells

Efficient drug delivery to the tumor cells was carried out with HER2 targeting peptide-conjugated PEGlyted PAMAM.

Analysis of different HER-2 mutations in breast cancer progression and drug resistance

Studies over the last two decades have identified that amplified human epidermal growth factor receptor (HER‐2; c‐erbB‐2, neu) and its overexpression have been frequently implicated in the carcinogenesis and prognosis in a variety of solid tumours, especially breast cancer. Lots of painstaking efforts were invested on the HER‐2 targeted agents, and significantly improved outcome and prolonged the survival of patients. However, some patients classified as ‘HER‐2‐positive’ would be still resistant to the anti‐HER‐2 therapy. Various mechanisms of drug resistance have been illustrated and the alteration of HER‐2 was considered as a crucial mechanism. However, systematic researches in regard to the HER‐2 mutations and variants are still inadequate. Notably, the alterations of HER‐2 play an important role in drug resistance, but also have a potential association with the cancer risk. In this review, we summarize the possible mutations and focus on HER‐2 variants’ role in breast cancer tumourigenesis. Additionally, the alteration of HER‐2, as a potential mechanism of resistance to trastuzumab, is discussed here. We hope that HER‐2 related activating mutations could potentially offer more therapeutic opportunities to a broader range of patients than previously classified as HER‐2 overexpressed.

Microarray based screening of peptide nano probes for HER2 positive tumor

Peptides are excellent biointerface molecules and diagnostic probes with many advantages such as good penetration, short turnover time, and low cost. We report here an efficient peptide screening strategy based on in situ single bead sequencing on a microarray. Two novel peptides YLFFVFER (H6) and KLRLEWNR (H10) specifically binding to the tumor biomarker human epidermal growth factor receptor 2 (HER2) with aKD of 10(-8) M were obtained from a 10(5) library. Conjugated to nanoparticles, both the H6 and H10 probes showed specific accumulation in HER2-positive tumor tissues in xenografted mice by in vivo imaging.

HER2 gene amplification and protein expression in pancreatic ductal adenocarcinomas

BACKGROUND

Despite advances in combination therapies, the prognosis of pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. Blocking of overexpressed HER2 oncogene improves survival in breast and gastroesophageal cancer and might be also a therapeutic option in PDAC. The purpose of this study was to evaluate HER2 gene amplification and protein expression in PDAC.

METHODS

HER2 protein expression was investigated using a FDA-approved antibody in 87 formalin-fixed and paraffin-embedded cases of PDAC with complete follow-up. HER2 gene amplification was assessed on tissue microarrays using dual color silver in situ hybridization (DISH).

RESULTS

Generally, HER2 immunostaining showed considerable heterogeneity. In 19 cases, ≥10 of tumor cells showed some positive reaction. In no case, complete membranous staining was observed. Using the scoring system developed for assessment of HER2 status in gastroesophageal cancer, 9 cases showed positive immunohistologic staining (score 2+ to 3+). After performing DISH, 6 (7%) immunohistochemically 2+ or 3+ cases were found to have HER2 gene amplification, whereas none of these cases showed polyploidy. No association of HER2 status and clinicopathologic parameters or survival was observed (P>0.05).

CONCLUSIONS

HER2 is overexpressed in a subset of PDACs, identifying them as possible candidates for a targeted therapy. For assessment of HER2 status in PDAC, the scoring system originally developed for gastric cancer is recommend.

Personalized drug combinations to overcome trastuzumab resistance in HER2-positive breast cancer

HER2-positive (HER2+) breast cancer accounts for 18%-20% of all breast cancer cases and has the second poorest prognosis among breast cancer subtypes. Trastuzumab, the first Food and Drug Administration-approved targeted therapy for breast cancer, established the era of personalized treatment for HER2+ metastatic disease. It is well tolerated and improves overall survival and time-to-disease progression; with chemotherapy, it is part of the standard of care for patients with HER2+ metastatic disease. However, many patients do not benefit from it because of resistance. Substantial research has been performed to understand the mechanism of trastuzumab resistance and develop combination strategies to overcome the resistance. In this review, we provide insight into the current pipeline of drugs used in combination with trastuzumab and the degree to which these combinations have been evaluated, especially in patients who have experienced disease progression on trastuzumab. We conclude with a discussion of the current challenges and future therapeutic approaches to trastuzumab-based combination therapy.

Non-initiation and early discontinuation of adjuvant trastuzumab in women with localized HER2-positive breast cancer

One year of trastuzumab therapy is recommended for women with HER2-positive breast cancer ≥ 1.0 cm in size to increase survival and is considered for women with tumors 0.5-0.9 cm in size. We analyzed compliance with trastuzumab among women with HER2-positive breast cancer in a prospective cohort study. Of 1145 recruited patients with breast cancer, 152 were HER2-positive (13.2 %), of whom 126 had tumors ≥ 1.0 cm; 110/126 (87.3 %) of these initiated trastuzumab. Non-receipt was associated with older age, better prognosis tumors, and with non-receipt of adjuvant chemotherapy. Of the 110 who initiated treatment, 18 (15 %) did not complete treatment, 15 (83 %) of them because of cardiotoxicity. Of 20 women with tumors 0.5-0.9 cm, 5 (25 %) initiated trastuzumab. Compliance with trastuzumab was very high among those with HER2-positive breast cancer, as was the completion of the recommended therapy.

Microenvironment, oncoantigens, and antitumor vaccination: lessons learned from BALB-neuT mice

The tyrosine kinase human epidermal growth factor receptor 2 (HER2) gene is amplified in approximately 20% of human breast cancers and is associated with an aggressive clinical course and the early development of metastasis. Its crucial role in tumor growth and progression makes HER2 a prototypic oncoantigen, the targeting of which may be critical for the development of effective anticancer therapies. The setup of anti-HER2 targeting strategies has revolutionized the clinical outcome of HER2⁺ breast cancer. However, their initial success has been overshadowed by the onset of pharmacological resistance that renders them ineffective. Since the tumor microenvironment (TME) plays a crucial role in drug resistance, the design of more effective anticancer therapies should depend on the targeting of both cancer cells and their TME as a whole. In this review, starting from the successful know-how obtained with a HER2⁺ mouse model of mammary carcinogenesis, the BALB-neuT mice, we discuss the role of TME in mammary tumor development. Indeed, a deeper knowledge of antigens critical for cancer outbreak and progression and of the mechanisms that regulate the interplay between cancer and stromal cell populations could advise promising ways for the development of the best anticancer strategy.

Single compartment drug delivery

Drug design is built on the concept that key molecular targets of disease are isolated in the diseased tissue. Systemic drug administration would be sufficient for targeting in such a case. It is, however, common for enzymes or receptors that are integral to disease to be structurally similar or identical to those that play important biological roles in normal tissues of the body. Additionally, systemic administration may not lead to local drug concentrations high enough to yield disease modification because of rapid systemic metabolism or lack of sufficient partitioning into the diseased tissue compartment. This review focuses on drug delivery methods that physically target drugs to individual compartments of the body. Compartments such as the bladder, peritoneum, brain, eye and skin are often sites of disease and can sometimes be viewed as "privileged," since they intrinsically hinder partitioning of systemically administered agents. These compartments have become the focus of a wide array of procedures and devices for direct administration of drugs. We discuss the rationale behind single compartment drug delivery for each of these compartments, and give an overview of examples at different development stages, from the lab bench to phase III clinical trials to clinical practice. We approach single compartment drug delivery from both a translational and a technological perspective.

PET probes beyond (18)F-FDG

During the past several decades, positron emission tomography (PET) has been one of the rapidly growing areas of medical imaging; particularly, its applications in routine oncological practice have been widely recognized. At present, (18)F-fluorodeoxyglucose ((18)F-FDG) is the most broadly used PET probe. However, (18)F-FDG also suffers many limitations. Thus, scientists and clinicians are greatly interested in exploring and developing new PET imaging probes with high affinity and specificity. In this review, we briefly summarize the representative PET probes beyond (18)F-FDG that are available for patients imaging in three major clinical areas (oncology, neurology and cardiology), and we also discuss the feasibility and trends in developing new PET probes for personalized medicine.

Oestrogen receptors in breast cancer: basic mechanisms and clinical implications

Since the discovery of the connection between ovarian hormones and breast cancer, endocrine therapy has been an integral adjuvant treatment for patients with hormone-dependent breast cancers. Oestrogen receptor (ER) plays a central role in mediating the effects of endogenous hormones and therapeutic agents. ER serves as a prognostic marker for responsiveness to endocrine therapy and is targeted either directly by selective oestrogen receptor modulators (SERMs) and pure antagonists or indirectly by aromatase inhibitors (AIs) that block oestrogen production. A significant number of ER-positive patients, however, fail to respond to therapy or develop resistance over time. This review focuses on the current understanding of ER functions and recent advances in genomic technologies and research that have provided a global perspective on hormone and ER activity and led to a number of significant discoveries, including the roles of co-regulatory factors and non-coding RNAs. Mechanistic insights into normal ER functions and therapeutic actions of SERMs and AIs will enable the development of better predictive markers and more effective target mechanisms and ultimately facilitate improvements in disease outcomes and patient survival.

A systematic review of trastuzumab and lapatinib in the treatment of women with brain metastases from HER2-positive breast cancer

Patients with HER2-positive breast cancer are living still longer and increasingly experiencing brain metastases. Current HER2-targeted therapies have limited potential to cross the blood-brain-barrier. We performed a systematic review to investigate data on HER2-targeting therapies in the treatment of brain metastases in breast cancer. We searched PUBMED for all human studies published 1998-2012 using the following search terms: breast neoplasm/cancer, human epidermal growth factor receptor 2/HER2, ErbB2, trastuzumab, lapatinib, brain/cerebral neoplasm/metastases and blood-brain barrier. We identified few and mostly small clinical studies. Study designs were very heterogeneous making comparisons on endpoints difficult. Overall survival for patients treated with trastuzumab varied from 8 to 25 months and 5.5 to 11 months for patients receiving lapatinib. The majority of studies were retrospective thus possibly biasing data. Only three studies were identified comparing trastuzumab to lapatinib. Conclusively, no solid data exist on how to treat patients with HER2-positive disease and brain metastases. Although continuous HER2-blockade is recommended by international consensus guidelines, it is still not evident which HER2-targeting agent should be preferred when brain metastases occur. The choice of chemotherapy to accompany the blockade is not obvious and we do not know if dual is better than single blockade. Further clinical trials are urgently needed.