Chemo- and regio-selective differential modification of native cysteines on an antibody via the use of dehydroalanine forming reagents

Protein modification has garnered increasing interest over the past few decades and has become an important tool in many aspects of chemical biology. In recent years, much effort has focused on site-selective modification strategies that generate more homogenous bioconjugates, and this is particularly so in the antibody modification space. Modifying native antibodies by targeting solvent-accessible cysteines liberated by interchain disulfide reduction is, perhaps, the predominant strategy for achieving more site-selectivity on an antibody scaffold. This is evidenced by numerous approved antibody therapeutics that have utilised cysteine-directed conjugation reagents and the plethora of methods/strategies focused on antibody cysteine modification. However, all of these methods have a common feature in that after the reduction of native solvent-accessible cystines, the liberated cysteines are all reacted in the same manner. Herein, we report the discovery and application of dehydroalanine forming reagents (including novel reagents) capable of regio- and chemo-selectively modifying these cysteines (differentially) on a clinically relevant antibody fragment and a full antibody. We discovered that these reagents could enable differential reactivity between light chain C-terminal cysteines, heavy chain hinge region cysteines (cysteines with an adjacent proline residue, Cys-Pro), and other heavy chain internal cysteines. This differential reactivity was also showcased on small molecules and on the peptide somatostatin. The application of these dehydroalanine forming reagents was exemplified in the preparation of a dually modified antibody fragment and full antibody. Additionally, we discovered that readily available amide coupling agents can be repurposed as dehydroalanine forming reagents, which could be of interest to the broader field of chemical biology.

Emerging role of MYB transcription factors in cancer drug resistance

Decades ago, the viral myeloblastosis oncogene v-myb was identified as a gene responsible for the development of avian leukemia. However, the relevance of MYB proteins for human cancer diseases, in particular for solid tumors, remained basically unrecognized for a very long time. The human family of MYB transcription factors comprises MYB (c-MYB), MYBL2 (b-MYB), and MYBL1 (a-MYB), which are overexpressed in several cancers and are associated with cancer progression and resistance to anticancer drugs. In addition to overexpression, the presence of activated MYB-fusion proteins as tumor drivers was described in certain cancers. The identification of anticancer drug resistance mediated by MYB proteins and their underlying mechanisms are of great importance in understanding failures of current therapies and establishing new and more efficient therapy regimens. In addition, new drug candidates targeting MYB transcription factor activity and signaling have emerged as a promising class of potential anticancer therapeutics that could tackle MYB-dependent drug-resistant cancers in a more selective way. This review describes the correlation of MYB transcription factors with the formation and persistence of cancer resistance to various approved and investigational anticancer drugs.

Engineering a modular double-transmembrane synthetic receptor system for customizing cellular programs

Implementation of designer receptors in engineered cells confers them to sense a particular physiological or disease state and respond with user-defined programs. To expand the therapeutic application scope of engineered cells, synthetic receptors realized through different strategies are in great demand. Here, we develop a synthetic receptor system that exerts dual control by incorporating two transmembrane helices for the signal chain. Together with a sensor-actuator device with minimal background signals and a positive loop circuit, this receptor system can sensitively respond to extracellular protein signals. We demonstrate that this synthetic receptor system can be readily adapted to respond to various inputs, such as interleukin-1 (IL-1), programmed death ligand 1 (PD-L1), and HER2, and release customized outputs, including fluorescence signals and the therapeutic molecule IL-2. The robust signaling ability and generality of this receptor system promise it to be a useful tool in the field of cell engineering for fundamental research and translational applications.

ZIM, a Norbornene Derived from 4-Aminoantipyrine, Induces DNA Damage and Cell Death but in Association Reduces the Effect of Commercial Chemotherapeutics

Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed. Here, we evaluated the effects of ZIM, a candidate for chemotherapy, and 4-AA alone and in association with commercial chemotherapeutic agents. Subsequently, the results of ZIM and 4-AA were compared. Male Swiss mice were treated with doses of 12, 24, or 48 mg/kg ZIM or 4-AA alone or in association with cisplatin (6 mg/kg), doxorubicin (16 mg/kg), and cyclophosphamide (100 mg/kg). Biometric parameters, DNA damage (comet and micronuclei), cell death, and splenic phagocytosis were evaluated. DNA docking was also performed to confirm the possible interactions of ZIM and 4-AA with DNA. 4-AA has been shown to have low genotoxic potential, increase the frequency of cell death, and activate phagocytosis. ZIM causes genomic and chromosomal damage in addition to causing cell death and activating phagocytosis. In association with chemotherapeutical agents, both 4-AA and ZIM have a chemopreventive effect and, therefore, reduce the frequency of DNA damage, cell death, and splenic phagocytosis. The association of 4-AA and ZIM with commercial chemotherapeutic agents increased the frequency of lymphocytes compared to chemotherapeutic agents alone. Molecular docking demonstrated that ZIM has more affinity for DNA than 4-AA and its precursors (1 and 2). This was confirmed by the lower interaction energy of the complex (-119.83 kcal/mol). ZIM can break the DNA molecule and, therefore, its chemotherapeutic effect can be related to DNA damage. It is considered that ZIM has chemotherapeutic potential. However, it should not be used in combination with cisplatin, doxorubicin, and cyclophosphamide as it reduces the effects of these drugs.

Regulation of Signaling from the Epidermal Growth Factor Family

The epidermal growth factor (EGF) system has allowed chemists, biologists, and clinicians to improve our understanding of cell production and cancer therapy. The discovery of EGF led to the recognition of cell surface receptors capable of controlling the proliferation and survival of cells. The detailed structures of the EGF-like ligand and the responses of their receptors (EGFR-family) has revealed the conformational and aggregation changes whereby ligands activate the intracellular kinase domains. Biophysical analysis has revealed the preformed clustering of different EGFR-family members and the processes which occur on ligand binding. Understanding these receptor activation processes and the consequential cytoplasmic signaling has allowed the development of inhibitors which are revolutionizing cancer therapy. This Review describes the recent progress in our understanding of the activation of the EGFR-family, the effects of signaling from the EGFR-family on cell proliferation, and the targeting of the EGFR-family in cancer treatment.

The current staging and classification systems of breast cancer and their pitfalls: Is it possible to integrate the complexity of this neoplasm into a unified staging system?

Breast cancer is one of the leading causes of cancer death in women worldwide due to its variable aggressiveness and high propensity to develop distant metastases. The staging can be performed clinically or pathologically, generating the stage stratification by the TNM (T - tumor size; N- lymph node metastasis; M - distant organ metastasis) system. However, cancers with virtually identical TNM characteristics can present highly contrasting behaviors due to the divergence of molecular profiles. This review focuses on the histopathological nuances and molecular understanding of breast cancer through the profiling of gene and protein expression, culminating in improvements promoted by the integration of this information into the traditional staging system. As a culminating point, it will highlight predictive statistical tools for genomic risks and decision algorithms as a possible solution to integrate the various systems because they have the potential to reduce the indications for such tests, serving as a funnel in association with staging and previous classification.

Critical roles for EGFR and EGFR-HER2 clusters in EGF binding of SW620 human carcinoma cells

Epidermal growth factor (EGF) signalling regulates normal epithelial and other cell growth, with EGF receptor (EGFR) overexpression reported in many cancers. However, the role of EGFR clusters in cancer and their dependence on EGF binding is unclear. We present novel single-molecule total internal reflection fluorescence microscopy of (i) EGF and EGFR in living cancer cells, (ii) the action of anti-cancer drugs that separately target EGFR and human EGFR2 (HER2) on these cells and (iii) EGFR–HER2 interactions. We selected human epithelial SW620 carcinoma cells for their low level of native EGFR expression, for stable transfection with fluorescent protein labelled EGFR, and imaged these using single-molecule localization microscopy to quantify receptor architectures and dynamics upon EGF binding. Prior to EGF binding, we observe pre-formed EGFR clusters. Unexpectedly, clusters likely contain both EGFR and HER2, consistent with co-diffusion of EGFR and HER2 observed in a different model CHO-K1 cell line, whose stoichiometry increases following EGF binding. We observe a mean EGFR : EGF stoichiometry of approximately 4 : 1 for plasma membrane-colocalized EGFR–EGF that we can explain using novel time-dependent kinetics modelling, indicating preferential ligand binding to monomers. Our results may inform future cancer drug developments.

Targeting HER2 in Breast Cancer: Latest Developments on Treatment Sequencing and the Introduction of Biosimilars

Approximately 20% of all breast cancers overexpress the human epidermal growth factor receptor 2 (HER2). Targeting breast cancer through this vital oncogenic protein has been a major step towards improved patient outcomes. Today, several anti-HER2 agents are in clinical use including: the monoclonal antibodies trastuzumab and pertuzumab; the small molecule inhibitors lapatinib, neratinib, and tucatinib; and the antibody-drug conjugates ado-trastuzumab emtansine and trastuzumab deruxtecan, in some jurisdictions. In addition, several trastuzumab biosimilars have recently been granted regulatory approval in North America and the EU, and are enhancing patient access to HER2-directed therapy. The various agents differ greatly in their side-effect profiles and approved indications, from neoadjuvant and adjuvant use in early disease, to first- and later-line use in metastatic disease. This review discusses the current treatment recommendations for the use of anti-HER2 agents alone and in combination, examines the latest advances in HER2-targeted drugs and how they may be best applied in clinical practice, and provides guidance on optimal sequencing of the growing array of therapeutic options for HER2-positive breast cancer.

Biosimilars in an era of rising oncology treatment options

New diagnostic technologies, including molecular profiling, have enabled advances in treatments of various cancers; this has significantly improved clinical outcomes, including overall survival. However, the high cost of biologic drugs may prevent patients from having access to optimal treatment. Introduction of lower priced biosimilar agents into the therapeutic armamentarium brings the potential to ease the burden on healthcare expenditure and facilitate better access to effective cancer treatments. Oncology biosimilars have shown comparable efficacy and safety based on clinical evidence and physicochemical quality data as well as in real-world settings. This paper aims to review changes in the management of oncology treatment and their implication with respect to biosimilars.

Tumor uptake and associated greater efficacy of anti-Her2 immunoliposome does not rely on Her2 expression status: study of a docetaxel-trastuzumab immunoliposome on Her2+ breast cancer model (SKBR3)

Nanoparticles have been used for decades in breast cancer. More recently, anti-human epidermal receptor 2 (Her2) immunoliposomes are of rising interest. However, recent studies have questioned the actual relevance of using anti-Her2 antibodies to improve liposome distribution and efficacy. Using standard thin-film method and maleimide linker, we have synthesized a 140-nm docetaxel-trastuzumab immunoliposome. This nanoparticle was then tested on a canonical Her2-overexpressing breast cancer model (i.e., SKBR3), using 3D spheroids and xenografted mice. Its efficacy was compared with free docetaxel + trastuzumab, liposomal docetaxel + free trastuzumab and to reference antibody-drug conjugate trastuzumab-emtansine (T-DM1). Immunoliposomes resulted in better efficacy as compared with all other treatments, both in vitro and in vivo. To explain such an improvement, immunoliposome biodistribution was investigated using live imaging in xenografted mice. Surprisingly, no difference in tumor uptake was found between anti-Her2 immunoliposomes and standard docetaxel liposomes (i.e., 1.9 ± 1.2 vs. 1.7 ± 0.5% at the end of treatment and 1.4 ± 0.6 vs. 1.6 ± 0.4% at the end of the study, respectively, P > 0.05). We hypothesized that passive targeting (i.e., enhanced permeation and retention effect) contributed more to tumor distribution than active targeting and that the observed differences in efficacy could come from a better internalization of immunoliposomes into Her2+ cells as compared with standard liposomes, and not from a higher specificity towards tumor tissue.

Clinical Trial in a Dish: Using Patient-Derived Induced Pluripotent Stem Cells to Identify Risks of Drug-Induced Cardiotoxicity

Drug-induced cardiotoxicity is a significant clinical issue, with many drugs in the market being labeled with warnings on cardiovascular adverse effects. Treatments are often prematurely halted when cardiotoxicity is observed, which limits their therapeutic potential. Moreover, cardiotoxicity is a major reason for abandonment during drug development, reducing available treatment options for diseases and creating a significant financial burden and disincentive for drug developers. Thus, it is important to minimize the cardiotoxic effects of medications that are in use or in development. To this end, identifying patients at a higher risk of developing cardiovascular adverse effects for the drug of interest may be an effective strategy. The discovery of human induced pluripotent stem cells has enabled researchers to generate relevant cell types that retain a patient's own genome and examine patient-specific disease mechanisms, paving the way for precision medicine. Combined with the rapid development of pharmacogenomic analysis, the ability of induced pluripotent stem cell-derivatives to recapitulate patient-specific drug responses provides a powerful platform to identify subsets of patients who are particularly vulnerable to drug-induced cardiotoxicity. In this review, we will discuss the current use of patient-specific induced pluripotent stem cells in identifying populations who are at risk to drug-induced cardiotoxicity and their potential applications in future precision medicine practice. Graphic Abstract: A graphic abstract is available for this article.

Recent progress in immunotherapy of breast cancer targeting the human epidermal growth factor receptor 2 (HER2)

OBJECTIVE

Breast cancer is responsible for most of the cancer-induced deaths in women around the world. The current review will discuss different approaches of targeting HER2, an epidermal growth factor overexpressed in 30% of breast cancer cases.

DATA SOURCES

We conducted a search on Pubmed and Scopus databases to find studies relevant to HER2+ breast cancers and targeting HER2 as means of immunotherapy. Out of 1043 articles, 105 studies were included in this review.

DATA SUMMARY

As well as the introduction of HER2 and breast cancer subtypes, we discussed various aspects of HER2-targeting immunotherapy including monoclonal antibodies, Antibody-drug conjugates (ADCs), Chimeric Antigen Receptor (CAR) T-cells and vaccines.

CONCLUSIONS

Despite several ways of controlling breast cancer, the need to investigate new drugs and approaches seems to be much significant as this cancer still has a heavy burden on people's health and survival.

Design and Implementation of NK Cell-Based Immunotherapy to Overcome the Solid Tumor Microenvironment

Natural killer (NK) cells are innate immune effectors capable of broad cytotoxicity via germline-encoded receptors and can have conferred cytotoxic potential via the addition of chimeric antigen receptors. Combined with their reduced risk of graft-versus-host disease (GvHD) and cytokine release syndrome (CRS), NK cells are an attractive therapeutic platform. While significant progress has been made in treating hematological malignancies, challenges remain in using NK cell-based therapy to combat solid tumors due to their immunosuppressive tumor microenvironments (TMEs). The development of novel strategies enabling NK cells to resist the deleterious effects of the TME is critical to their therapeutic success against solid tumors. In this review, we discuss strategies that apply various genetic and non-genetic engineering approaches to enhance receptor-mediated NK cell cytotoxicity, improve NK cell resistance to TME effects, and enhance persistence in the TME. The successful design and application of these strategies will ultimately lead to more efficacious NK cell therapies to treat patients with solid tumors. This review outlines the mechanisms by which TME components suppress the anti-tumor activity of endogenous and adoptively transferred NK cells while also describing various approaches whose implementation in NK cells may lead to a more robust therapeutic platform against solid tumors.

Xeloda Oral, Trastuzumab, and Pertuzumab Combined Drug Therapy Reduced Cervical Lymphadenopathy and Dermal Involvement in Patient With Recurrent Breast Cancer: Case Report

We report the case of a 42-year-old woman who was diagnosed with breast cancer that recurred 3 years later, with supraclavicular lymphadenopathy and dermal involvement. The main drug used in the therapy was trastuzumab; however, the association of this drug with docetaxel was not able to decrease or cease the effect of the inflammatory BCA component with erythema and thickening of the skin as well as the supraclavicular lymphadenopathy previously diagnosed. Thus, a combined therapy was required. The patient was started on 6 cycles (1 per month) of trastuzumab subcutaneous 600 mg, pertuzumab intravenous 840 mg (as an attack dose, later on 420 mg), and xeloda oral 1000 mg. As a result, the patient showed a significant improvement in erythema and thickening of the skin in the neck and the right part of her trunk, besides decrease in supraclavicular lymphadenopathy. After 6 cycles, her skin was almost restored. Intravenous trastuzumab can be an effective single agent; however, its association with other chemotherapies—such as pertuzumab—can present a synergic effect, which can increase the survival expectations of metastatic HER2+ patients. Additionally, as reported in the literature, the use of xeloda plays a key role in restoring the skin health of patients with breast cancer presenting with skin metastasis. Our findings suggest that trastuzumab, pertuzumab, and xeloda combined therapy, following the schedule and posology handled in this study, can be a good treatment for recurrent HER2+ breast cancer with signs of supraclavicular lymphadenopathy and severe inflammatory BCA component with erythema and thickening of the skin.

Negative regulators of cell death pathways in cancer: perspective on biomarkers and targeted therapies

Cancer is a primary cause of human fatality and conventional cancer therapies, e.g., chemotherapy, are often associated with adverse side-effects, tumor drug-resistance, and recurrence. Molecularly targeted therapy, composed of small-molecule inhibitors and immunotherapy (e.g., monoclonal antibody and cancer vaccines), is a less harmful alternative being more effective against cancer cells whilst preserving healthy tissues. Drug-resistance, however, caused by negative regulation of cell death signaling pathways, is still a challenge. Circumvention of negative regulators of cell death pathways or development of predictive and response biomarkers is, therefore, quintessential. This review critically discusses the current state of knowledge on targeting negative regulators of cell death signaling pathways including apoptosis, ferroptosis, necroptosis, autophagy, and anoikis and evaluates the recent advances in clinical and preclinical research on biomarkers of negative regulators. It aims to provide a comprehensive platform for designing efficacious polytherapies including novel agents for restoring cell death signaling pathways or targeting alternative resistance pathways to improve the chances for antitumor responses. Overall, it is concluded that nonapoptotic cell death pathways are a potential research arena for drug discovery, development of novel biomarkers and targeted therapies.

Ex Vivo-expanded Natural Killer Cells Derived From Long-term Cryopreserved Cord Blood are Cytotoxic Against Primary Breast Cancer Cells

With over 600,000 units of umbilical cord blood (CB) stored on a global scale, it is important to elucidate the therapeutic abilities of this cryopreserved reservoir. In the advancing field of natural killer (NK) cell cancer immunotherapy, CB has proven to be a promising and noninvasive source of therapeutic NK cells. Although studies have proven the clinical efficacy of using long-term cryopreserved CB in the context of hematopoietic stem cell transplantations, little is known about its use for the ex vivo expansion of effector immune cells. Therefore, our group sought to derive ex vivo-expanded NK cells from long-term cryopreserved CB, using an artificial antigen presenting cell-mediated expansion technique. We compared the expansion potential and antitumor effector function of CB-derived NK (CB-NK) cells expanded from fresh (n=4), short-term cryopreserved (<1-year old, n=5), and long-term cryopreserved (1-10-year old, n=5) CB. Here, we demonstrated it is possible to obtain an exponential amount of expanded CB-NK cells from long-term cryopreserved CB. Ex vivo-expanded CB-NK cells had an increased surface expression of activating markers and showed potent antitumor function by producing robust levels of proinflammatory cytokines, interferon-γ, and tumor necrosis factor-α. Moreover, expanded CB-NK cells (n=3-5) demonstrated cytotoxicity towards primary breast cancer cells (n=2) derived from a triple-negative breast cancer and an estrogen receptor-positive/progesterone receptor-positive breast cancer patient. Long-term cryopreservation had no effect on the expansion potential or effector function of expanded CB-NK cells. Therefore, we propose that long-term cryopreserved CB remains clinically useful for the ex vivo expansion of therapeutic NK cells.

Etiologic Role of Kinases in the Progression of Human Cancers and Its Targeting Strategies

Cancer is one of the dominant causes of death worldwide while lifelong prognosis is still inauspicious. The maturation of the cancer is seen as a process of transformation of a healthy cell into a tumor-sensitive cell, which is held entirely at the cellular, molecular, and genetic levels of the organism. Tyrosine kinases can play a major, etiologic role in the inception of malignancy and devote to the uncontrolled proliferation of cancerous cells and the progression of a tumor as well as the development of metastatic disease. Angiogenesis and oncogene activation are the major event in cell proliferation. The growth of a tumor and metastasis are fully depending on angiogenesis and lymphangiogenesis triggered by chemical signals from tumor cells in a phase of rapid growth. Tyrosine kinase inhibitors are compounds that inhibit tyrosine kinases and effective in targeting angiogenesis and blocking the signaling pathways of oncogenes. Small molecule tyrosine kinase inhibitors like afatinib, erlotinib, crizotinib, gefitinib, and cetuximab are shown to a selective cut off tactic toward the constitutive activation of an oncogene in tumor cells, and thus contemplated as promising therapeutic approaches for the diagnosis of cancer and malignancies.

Concomitant use of renin-angiotensin-aldosterone system inhibitors prevent trastuzumab-induced cardiotoxicity in HER2+ breast cancer patients: an institutional retrospective study

Background

Cardiotoxicity is an adverse effect of trastuzumab (TRA) in the treatment of human epidermal growth factor 2 positive (HER2+) breast cancer. Current literature on the cardioprotective effects of agents targeted against the renin-angiotensin-aldosterone system (RAAS) and beta-blockers (BB) in TRA-treated HER2+ breast cancer patients is conflicting. We hypothesized that concurrent use of RAAS inhibitors would prevent TRA-induced cardiotoxicity (TIC).

Methods and materials

Surveillance ejection fraction (EF) at 3-month intervals up to 36 months obtained from echocardiogram or multigated acquisition (MUGA) scans were retrospectively compared to baseline EF in TRA-treated HER2+ breast cancer patients between 2011 to 2016 at a tertiary cancer center. TIC was defined as a decrease of EF by more than 15 EF percentage points from baseline on surveillance imaging. Cardiac medications and comorbidities were compared between patients with reduced EF secondary to TIC (rEF) and patients who did not experience TIC (pEF). A published clinical risk score (CRS) was applied to the patient population with calculated sensitivity analyses to determine if the CRS could predict TIC.

Results

Of 127 patients with TRA-treated HER2+ breast cancer, 11% developed cardiotoxicity resulting in discontinuation of TRA. Cardiotoxicity with reduced EF was seen as early as 3 months and at subsequent 3-month follow up intervals up to the 15-month follow-up. Co-existing arrhythmia, coronary artery disease (CAD), hypertension (HTN) and diabetes mellitus (DM) tended to infer an increased risk for cardiotoxicity. Patients with pEF were found to be concurrently on a RAAS inhibitor more than the rEF group (OR of 0.24, 95% CI 0.05-1.11, p 0.06). The CRS high-risk cut-off had a sensitivity of 0.17 (95% CI 0.03-0.49), specificity of 0.89 (95% CI 0.82-0.94), positive predictive value of 0.14 (95% CI 0.03-0.44) and negative predictive value of 0.91 (95% CI 0.84-0.95).

Conclusion

Our data suggest that the concurrent use of a RAAS inhibitors during TRA treatment may provide a protective effect against TIC and warrants further investigation. The low sensitivity and positive predictive value demonstrated that the CRS has minimal utility as a screening tool for prediction of patients at high risk for TIC. Therefore, closer surveillance of patients receiving TRA is warranted for early detection of TIC.

Highly homogeneous antibody modification through optimisation of the synthesis and conjugation of functionalised dibromopyridazinediones

Herein we report novel protocols for the generation and application of dibromopyridazinediones, an exciting class of disulfide bridging reagents.

Due to their exquisite cysteine-selectivity, excellent stability, and ability to functionally rebridge disulfide bonds, dibromopyridazinediones are emerging as an exciting new class of bioconjugation reagents, particularly in the field of antibody conjugation. Despite this, relatively little work has been performed on the optimisation of their synthesis and subsequent reaction with immunoglobulins. Herein we present a novel synthetic route towards functionalised dibromopyridazinediones, proceeding via an isolatable dibromopyridazinedione-NHS ester. Reaction of this activated intermediate with a variety of amines produces functional dibromopyridazinediones in good to excellent yields. The disulfide rebridging capacity of these reagents was optimised on the clinically relevant IgG1 trastuzumab, resulting in a general method which allows for the generation of site-selectively modified native trastuzumab with over 90% homogeneity (no disulfide scrambling) without the need for protein engineering or enzymatic conjugation.

Trastuzumab induces PUMA-dependent apoptosis and inhibits tumor growth in gastric cancer

Gastric cancer (GC) is one of the most prevalent cancers worldwide. Trastuzumab has been approved for the treatment of metastatic GC, gastroesophageal junction cancer, and breast cancer. However, the mechanisms involved in trastuzumab-induced GC cell apoptosis remain largely unknown. In this study, we investigated the underlying mechanisms of trastuzumab-mediated suppression of GC cell growth both in vitro and in vivo. We found that trastuzumab treatment induces p53 upregulated modulator of apoptosis (PUMA) expression in GC cells, through the NF-κB pathway following AKT inhibition and glycogen synthase kinase 3β (GSK3β) activation. We also observed that PUMA was necessary for trastuzumab-induced apoptosis in GC cells. Moreover, PUMA deficiency suppressed apoptosis and the antitumor effect of trastuzumab in xenograft models. Finally, computerized tomography (CT) and immunohistochemistry results showed that patients with increased activation of PUMA were more sensitive to trastuzumab treatment than those with low PUMA expression. These results indicate that trastuzumab induces PUMA-dependent apoptosis and inhibits tumor growth in GC, suggesting that PUMA plays a critical role in mediating the antitumor effects of trastuzumab in GC. PUMA induction may be used as a marker of trastuzumab sensitivity.

Developing a genetic signature to predict drug response in ovarian cancer

There is a lack of personalized treatment options for women with recurrent platinum-resistant ovarian cancer. Outside of bevacizumab and a group of poly ADP-ribose polymerase inhibitors, few options are available to women that relapse. We propose that efficacious drug combinations can be determined via molecular characterization of ovarian tumors along with pre-established pharmacogenomic profiles of repurposed compounds. To that end, we selectively performed multiple two-drug combination treatments in ovarian cancer cell lines that included reactive oxygen species inducers and HSP90 inhibitors. This allowed us to select cell lines that exhibit disparate phenotypes of proliferative inhibition to a specific drug combination of auranofin and AUY922. We profiled altered mechanistic responses from these agents in both reactive oxygen species and HSP90 pathways, as well as investigated PRKCI and lncRNA expression in ovarian cancer cell line models. Generation of dual multi-gene panels implicated in resistance or sensitivity to this drug combination was produced using RNA sequencing data and the validity of the resistant signature was examined using high-density RT-qPCR. Finally, data mining for the prevalence of these signatures in a large-scale clinical study alluded to the prevalence of resistant genes in ovarian tumor biology. Our results demonstrate that high-throughput viability screens paired with reliable in silico data can promote the discovery of effective, personalized therapeutic options for a currently untreatable disease.

Natural killer cells unleashed: Checkpoint receptor blockade and BiKE/TriKE utilization in NK-mediated anti-tumor immunotherapy

Natural killer (NK) cells have long been known to mediate anti-tumor responses without prior sensitization or recognition of specific tumor antigens. However, the tumor microenvironment can suppress NK cell function resulting in tumor escape and disease progression. Despite recent advances in cytokine therapy and NK cell adoptive transfer, tumor expression of ligands to NK - expressed checkpoint receptors can still suppress NK mediated tumor lysis. This review will explore many of the checkpoint receptors tumors utilize to manipulate the NK cell response as well as some of the current and upcoming pharmacological solutions to limit tumor suppression of NK cell function. Furthermore, we will discuss the potential to use these drugs in combinational therapies with novel antibody reagents such as bi- and tri-specific killer engagers (BiKEs and TriKEs) against tumor-specific antigens to enhance NK cell-mediated tumor rejection.

Regulation of NKG2D-Dependent NK Cell Functions: The Yin and the Yang of Receptor Endocytosis

Natural-killer receptor group 2, member D (NKG2D) is a well characterized natural killer (NK) cell activating receptor that recognizes several ligands poorly expressed on healthy cells but up-regulated upon stressing stimuli in the context of cancer or viral infection. Although NKG2D ligands represent danger signals that render target cells more susceptible to NK cell lysis, accumulating evidence demonstrates that persistent exposure to ligand-expressing cells causes the decrease of NKG2D surface expression leading to a functional impairment of NKG2D-dependent NK cell functions. Upon ligand binding, NKG2D is internalized from the plasma membrane and sorted to lysosomes for degradation. However, receptor endocytosis is not only a mechanism of receptor clearance from the cell surface, but is also required for the proper activation of signalling events leading to the functional program of NK cells. This review is aimed at providing a summary of current literature relevant to the molecular mechanisms leading to NKG2D down-modulation with particular emphasis given to the role of NKG2D endocytosis in both receptor degradation and signal propagation. Examples of chronic ligand-induced down-regulation of NK cell activating receptors other than NKG2D, including natural cytotoxicity receptors (NCRs), DNAX accessory molecule-1 (DNAM1) and CD16, will be also discussed.

'Big data' approaches for novel anti-cancer drug discovery

INTRODUCTION

The development of improved cancer therapies is frequently cited as an urgent unmet medical need. Recent advances in platform technologies and the increasing availability of biological 'big data' are providing an unparalleled opportunity to systematically identify the key genes and pathways involved in tumorigenesis. The discoveries made using these new technologies may lead to novel therapeutic interventions. Areas covered: The authors discuss the current approaches that use 'big data' to identify cancer drivers. These approaches include the analysis of genomic sequencing data, pathway data, multi-platform data, identifying genetic interactions such as synthetic lethality and using cell line data. They review how big data is being used to identify novel drug targets. The authors then provide an overview of the available data repositories and tools being used at the forefront of cancer drug discovery. Expert opinion: Targeted therapies based on the genomic events driving the tumour will eventually inform treatment protocols. However, using a tailored approach to treat all tumour patients may require developing a large repertoire of targeted drugs.

In Vivo Efficacy of Umbilical Cord Blood Stem Cell-Derived NK Cells in the Treatment of Metastatic Colorectal Cancer

Therapeutic monoclonal antibodies against the epidermal growth factor receptor (EGFR) act by inhibiting EGFR downstream signaling and by eliciting a natural killer (NK) cell-mediated antitumor response. The IgG₁ mAb cetuximab has been used for treatment of RAS^wt metastatic colorectal cancer (mCRC) patients, showing limited efficacy. In the present study, we address the potential of adoptive NK cell therapy to overcome these limitations investigating two allogeneic NK cell products, i.e., allogeneic activated peripheral blood NK cells (A-PBNK) and umbilical cord blood stem cell-derived NK cells (UCB-NK). While cetuximab monotherapy was not effective against EGFR⁻ RAS^wt, EGFR⁺ RAS^mut, and EGFR⁺ BRAF^mut cells, A-PBNK were able to initiate lysis of EGFR⁺ colon cancer cells irrespective of RAS or BRAF status. Cytotoxic effects of A-PBNK (but not UCB-NK) were further potentiated significantly by coating EGFR⁺ colon cancer cells with cetuximab. Of note, a significantly higher cytotoxicity was induced by UCB-NK in EGFR⁻RAS^wt (42 ± 8 versus 67 ± 7%), EGFR⁺ RAS^mut (20 ± 2 versus 37 ± 6%), and EGFR⁺ BRAF^mut (23 ± 3 versus 43 ± 7%) colon cancer cells compared to A-PBNK and equaled the cytotoxic efficacy of the combination of A-PBNK and cetuximab. The antitumor efficacy of UCB-NK cells against cetuximab-resistant human EGFR⁺ RAS^mut colon cancer cells was further confirmed in an in vivo preclinical mouse model where UCB-NK showed enhanced antitumor cytotoxicity against colon cancer independent of EGFR and RAS status. As UCB-NK have been proven safe in a recently conducted phase I clinical trial in acute myeloid leukemia, a fast translation into clinical proof of concept for mCRC could be considered.

The need for fundamental reforms in the pain research field to develop innovative drugs

INTRODUCTION

Chronic pain is a major healthcare issue owing to its high prevalence, significant physical and emotional burden on the patients, and huge financial burden on the society. The efficacy of currently available medications is unsatisfactory owing to their limited effect size and the low responder rate (less than 50%). Thus, there is a large unmet need for innovative therapies for chronic pain. Areas covered: In this review, the author points out the need for fundamental reforms in pain research. For the last several decades, drug discovery research has extensively focused on designing new therapies using animal models of chronic pain. It has, however, made insufficient progress with respect to the launch of innovative analgesic drugs, because the translation from preclinical to clinical stages has not been satisfactory. Thus, the strategies for developing innovative analgesic drugs are discussed. Expert opinion: Points to be considered in the discovery of drugs for pain relief include: (1) the exclusion of bias incorporation and the alignment of clinical and preclinical endpoints in the assessment of analgesic efficacy; (2) the understanding of primary unmet needs; (3) the assessment of new therapies by biomarker-prioritized frameworks, and (4) the stratification of chronic pain sufferers.

The need for effective pancreatic cancer detection and management: a biomarker-based strategy

Pancreatic cancer (Pa) is generally a very aggressive disease, with few effective approaches available for early diagnosis or therapy. These factors, combined with the aggressiveness and chemoresistance of Pa, results in a bleak outcome post-diagnosis. Cancer-related biomarkers have established capabilities for diagnosis, prognosis and screening and can be exploited to aid in earlier less-invasive diagnosis and optimization of targeted therapies. Pa has only one US FDA-approved biomarker, CA19-9, which has significant limitations. Hence, it is vital that novel biomarkers are identified and validated to diagnose, treat, control and monitor Pa. This review focuses on existing and potential Pa-associated markers and discusses how they may be applied in cohort for improved management of Pa.

Generation of BiKEs and TriKEs to Improve NK Cell-Mediated Targeting of Tumor Cells

Cancer immunotherapies have gained significant momentum over the past decade, particularly with the advent of checkpoint inhibitors and CAR T-cells. While the latter personalized targeted immunotherapy has revolutionized the field, a need for off-the-shelf therapies remains. The ability of NK cells to quickly lyse antibody-coated tumors and potently secrete cytokines without prior priming has made NK cells ideal candidates for antigen-specific immunotherapy. NK cells have been targeted to tumors through two main strategies: mono-specific antibodies and bi/tri-specific antibodies. Mono-specific antibodies drive NK cell antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells. Bi/tri-specific antibodies drive re-directed lysis of tumor cells through binding of a tumor antigen and direct binding and crosslinking of the CD16 receptor on NK cells, thus bypassing the need for binding of the Fc portion of mono-specific antibodies. This chapter focuses on the generation of bi- and tri-specific killer engagers (BiKEs and TriKEs) meant to target NK cells to tumors. BiKEs and TriKEs are smaller molecules composed of 2-3 variable portions of antibodies with different specificities, and represent a novel and more versatile strategy compared to traditional bi- and tri-specific antibody platforms.

Classification of Cancer Primary Sites Using Machine Learning and Somatic Mutations

An accurate classification of human cancer, including its primary site, is important for better understanding of cancer and effective therapeutic strategies development. The available big data of somatic mutations provides us a great opportunity to investigate cancer classification using machine learning. Here, we explored the patterns of 1,760,846 somatic mutations identified from 230,255 cancer patients along with gene function information using support vector machine. Specifically, we performed a multiclass classification experiment over the 17 tumor sites using the gene symbol, somatic mutation, chromosome, and gene functional pathway as predictors for 6,751 subjects. The performance of the baseline using only gene features is 0.57 in accuracy. It was improved to 0.62 when adding the information of mutation and chromosome. Among the predictable primary tumor sites, the prediction of five primary sites (large intestine, liver, skin, pancreas, and lung) could achieve the performance with more than 0.70 in F-measure. The model of the large intestine ranked the first with 0.87 in F-measure. The results demonstrate that the somatic mutation information is useful for prediction of primary tumor sites with machine learning modeling. To our knowledge, this study is the first investigation of the primary sites classification using machine learning and somatic mutation data.

MicroRNA-induced drug resistance in gastric cancer

Drug resistance remains one of the major reasons of therapy failure in gastric cancer patients. Although the mechanisms of anticancer drug resistance have been broadly investigated, they have not been completely understood. Accumulating reports have recently highlighted the involvement of endogenous non-coding RNAs, known as microRNAs, in the evolution of cancer cell drug resistance. MiRNAs have been characterized as major regulators of crucial genes implicated in the chemoresistance phenotype of gastric cancer cells. MiRNA-based therapy in the future may provide a new strategy to overcome drug resistance. This review summarizes the current knowledge on the role of miRNAs in regulating drug resistance in gastric cancer and their potential to develop targeted therapies and personalized treatment for managing drug resistant gastric cancers.

Role of subcutaneous formulation of trastuzumab in the treatment of patients with HER2-positive breast cancer

Tumors in about 15% of patients with breast cancer overexpress HER2. Trastuzumab (Herceptin(®); F. Hoffmann-La Roche, Basel, Switzerland) is a humanized monoclonal antibody against HER2. While the introduction of trastuzumab has changed the natural course of HER2-positive breast cancer, the need for repeated administration of the drug over a prolonged period of time represents a challenge. Similarly to other chronic disorders, subcutaneous administration of monoclonal antibodies may be of advantage in this setting. The results of a prospective randomized Phase III study have demonstrated that subcutaneous trastuzumab is noninferior compared with the intravenous administration of the drug in terms of efficacy (assessed as pathological complete response rate) as well as in pharmacokinetic parameters. Moreover, another prospective randomized study showed that an overwhelming majority of patients prefer subcutaneous over intravenous trastuzumab. The advent of subcutaneous trastuzumab represents an important progress in the concept of cancer management that is based also on patient choice and preferences.

A comparative study of disease genes and drug targets in the human protein interactome

BACKGROUND

Disease genes cause or contribute genetically to the development of the most complex diseases. Drugs are the major approaches to treat the complex disease through interacting with their targets. Thus, drug targets are critical for treatment efficacy. However, the interrelationship between the disease genes and drug targets is not clear.

RESULTS

In this study, we comprehensively compared the network properties of disease genes and drug targets for five major disease categories (cancer, cardiovascular disease, immune system disease, metabolic disease, and nervous system disease). We first collected disease genes from genome-wide association studies (GWAS) for five disease categories and collected their corresponding drugs based on drugs' Anatomical Therapeutic Chemical (ATC) classification. Then, we obtained the drug targets for these five different disease categories. We found that, though the intersections between disease genes and drug targets were small, disease genes were significantly enriched in targets compared to their enrichment in human protein-coding genes. We further compared network properties of the proteins encoded by disease genes and drug targets in human protein-protein interaction networks (interactome). The results showed that the drug targets tended to have higher degree, higher betweenness, and lower clustering coefficient in cancer Furthermore, we observed a clear fraction increase of disease proteins or drug targets in the near neighborhood compared with the randomized genes.

CONCLUSIONS

The study presents the first comprehensive comparison of the disease genes and drug targets in the context of interactome. The results provide some foundational network characteristics for further designing computational strategies to predict novel drug targets and drug repurposing.

The biology of NK cells and their receptors affects clinical outcomes after hematopoietic cell transplantation (HCT)

Natural killer (NK) cells were first identified for their capacity to reject bone marrow allografts in lethally irradiated mice without prior sensitization. Subsequently, human NK cells were detected and defined by their non-major histocompatibility complex (MHC)-restricted cytotoxicity toward transformed or virally infected target cells. Karre et al. later proposed 'the missing self hypothesis' to explain the mechanism by which self-tolerant cells could kill targets that had lost self MHC class I. Subsequently, the receptors that recognize MHC class I to mediate tolerance in the host were identified on NK cells. These class I-recognizing receptors contribute to the acquisition of function by a dynamic process known as NK cell education or licensing. In the past, NK cells were assumed to be short lived, but more recently NK cells have been shown to mediate immunologic memory to secondary exposures to cytomegalovirus infection. Because of their ability to lyse tumors with aberrant MHC class I expression and to produce cytokines and chemokines upon activation, NK cells may be primed by many stimuli, including viruses and inflammation, to contribute to a graft-versus-tumor effect. In addition, interactions with other immune cells support the therapeutic potential of NK cells to eradicate tumor and to enhance outcomes after hematopoietic cell transplantation.

Monoclonal antibodies: Pharmacokinetics as a basis for new dosage regimens?

Complete monoclonal IgG antibodies which are in use in clinical practice share some pharmacological properties resulting in high concentrations in plasma. This fact is reflected in their low volumes of distribution, which can also be correlated with a high molecular weight and water solubility. This feature allows a novel approach to be applied to the dosing schedule for this group of drugs with fixed doses being used instead of the initially developed weight- or body surface-adjusted dosing schedules. In addition, the development of a new formulation containing hyaluronidase allows a subcutaneous route of administration to be used, because hyaluronidase creates a space in the subcutaneous tissue that helps antibody absorption. This method requires higher doses, but has allowed testing the feasibility of administering a fixed dose, with no individual dose adjustments based on weight or body surface. Moreover, loading doses are not needed, because the first dose results, within 3 weeks, in minimum concentrations that are higher than effective concentrations.

Subcutaneous trastuzumab: a review of its use in HER2-positive breast cancer

Trastuzumab (Herceptin®) is a humanized IgG1 monoclonal antibody that is an efficacious treatment for HER2-positive breast and gastric cancers. Subcutaneous trastuzumab is a new formulation approved in the European Union for use in patients with early or metastatic breast cancer. In the randomized, open-label, multinational HannaH (enHANced treatment with NeoAdjuvant Herceptin) study of neoadjuvant/adjuvant trastuzumab in patients with early HER2-positive breast cancer, the pharmacokinetics of neoadjuvant subcutaneous trastuzumab were similar to those after intravenous administration, meeting the noninferiority criterion for mean predose trough concentrations, as assessed prior to surgery (primary pharmacokinetic endpoint). Trastuzumab blood concentrations throughout the dosing interval remained above those considered necessary for anticancer activity. In this study, the pathologic complete response rates (primary efficacy endpoint) were 45.4 and 40.7 % in the subcutaneous and intravenous administration groups, respectively, meeting a study noninferiority criterion. In the randomized, open-label, crossover, multinational PrefHer study of neoadjuvant/adjuvant or adjuvant trastuzumab in early HER2-positive breast cancer, subcutaneous administration of trastuzumab was preferred over intravenous administration by >85 % of patients, most commonly because it was time saving and induced less pain and discomfort. In the HannaH study, the tolerability profile of subcutaneous trastuzumab was similar to that of intravenous trastuzumab, except that the rate of serious adverse events was 21 % (vs. 12 % with intravenous administration), partly because of more infections with subcutaneous administration. Whether this finding is of any clinical significance should emerge from ongoing studies. On the evidence, subcutaneous trastuzumab is an effective and generally well-tolerated treatment option that is preferred by patients over intravenous administration.

Advances and Prospects in Cancer Immunotherapy

Cancer immunotherapy is a promising and effective treatment modality for patients with cancers. Cytokine, anticytokine, and antibody therapies appear to be effective in treating various forms of cancer. The human papillomavirus vaccine is protective for cervical cancer, and this discovery has paved the way to the development of cancer vaccines for other forms of virus-associated cancers such as liver cancer and Merkel cell carcinoma. Clinical trials have demonstrated that adoptive cell therapy using tumor-infiltrating lymphocytes can induce tumor regression in approximately 75% of metastatic melanoma patients, suggesting the possibility of using similar technique to effectively treat breast, lung, and renal cancers in the near future. Besides, genetically engineered T cells transduced with genes encoding specific T cell receptors and chimeric antigen receptors have been shown effective in the treatment of cancer patients. These studies suggest that combination therapies are superior choices in cancer immunotherapy for patients.

A case report of trastuzumab dose in gastric cancer

INTRODUCTION

Trastuzumab (Herceptin®, F. Hoffman-La Roche) is now approved for the treatment of metastatic HER2-positive gastric cancer based on the improved survival observed on the phase III Trastuzumab for Gastric Adenocarcinoma (ToGA) study. Standard dosing of trastuzumab is currently extrapolated from breast cancer data: a 3-week schedule (8 mg/kg load, 6 mg/kg q 3 weeks) or a weekly schedule (4 mg/kg load, 2 mg/kg q week).

CASE STUDY

Our case study examines an HER2-positive metastatic gastric cancer patient that required a higher than currently recommended standard dose of trastuzumab to achieve treatment response.

DISCUSSION

Several mechanisms may explain these findings and include higher clearance of trastuzumab, higher tumor burden, and pharmacologic resistance in metastatic gastric cancer versus breast cancer. The question of trastuzumab dosing in gastric cancer is currently being evaluated in a phase III clinical trial.

Characterisation of glycoproteins using a quadrupole time-of-flight mass spectrometer configured for electron transfer dissociation

RATIONALE

Electron transfer dissociation (ETD) within ion trapping mass spectrometers has proven to be a useful tool for the characterisation of post-translational modifications. In this study, we describe the implementation of ETD upon a modified quadrupole time-of-flight (Q-ToF) system and methods for the analysis of glycoproteins.

METHODS

Liquid chromatography electrospray ionisation mass spectrometry (LC/ESI-MS) was performed using a hybrid quadrupole/ion mobility/oa-ToF mass spectrometer equipped with ETD functionality. 1,4-Dicyanobenzene reagent anions necessary for the ETD reaction were generated from a glow discharge region located within the ESI source block. ETD reactions occurred in the stacked ring travelling wave ion guide (located after the quadrupole mass filter and prior to the oa-ToF mass analyser). LC/ETD was performed upon 'super-charged' tryptic glycopeptide ions produced from the recombinant monoclonal antibody trastuzumab. LC/ETD was also performed on ions from the smaller glycopeptides obtained from erythropoietin.

RESULTS

ETD performed upon the quadruply 'super-charged' N-linked glycopeptide ions of trastuzumab and the triply charged O-linked glycopeptide ions of erythropoietin provided both glycosylation site assignments and full sequence information, respectively. Tandem mass (MS/MS) spectra employing collision-induced dissociation (CID) were dominated by oxonium product ions hampering full peptide sequence characterisation.

CONCLUSIONS

LC/ETD on the Q-ToF system proved effective at characterising a number of different N-linked glyco-forms of the tryptic peptide, EEQYNSTYR, from trastuzumab as well as glyco-forms from the O-linked tryptic peptide, EASIPPDAASAAPLR, from erythropoietin. The data demonstrates that the glycopeptide site heterogeneity of trastuzumab and erythropoietin can be accurately characterised. In addition, the post-column mixing of the super-charging reagent, m-NBA, is an effective method to increase the precursor ion charge state and to improve ETD reaction efficiency.

Considerations for the successful co-development of targeted cancer therapies and companion diagnostics

As diagnostic tests become increasingly important for optimizing the use of drugs to treat cancers, the co-development of a targeted therapy and its companion diagnostic test is becoming more prevalent and necessary. In July 2011, the US Food and Drug Administration released a draft guidance that gave the agency's formal definition of companion diagnostics and introduced a drug-diagnostic co-development process for gaining regulatory approval. Here, we identify areas of drug-diagnostic co-development that were either not covered by the guidance or that would benefit from increased granularity, including how to determine when clinical studies should be limited to biomarker-positive patients, defining the diagnostically selected patient population in which to use a companion diagnostic, and defining and clinically validating a biomarker signature for assays that use more than one biomarker. We propose potential approaches that sponsors could use to deal with these challenges and provide strategies to help guide the future co-development of drugs and diagnostics.

Membrane-type 6 matrix metalloproteinase regulates the activation-induced downmodulation of CD16 in human primary NK cells

CD16 (FcγRIIIa), the low-affinity receptor for IgG, expressed by the majority of human NK cells, is a potent activating receptor that facilitates Ab-dependent cell-mediated cytotoxicity (ADCC). ADCC dysfunction has been linked to cancer progression and poor prognosis for chronic infections, such as HIV; thus, understanding how CD16 expression is regulated by NK cells has clinical relevance. Importantly, CD16 cell-surface expression is downmodulated following NK cell activation and, in particular, exposure to stimulatory cytokines (IL-2 or IL-15), likely owing to the action of matrix metalloproteinases (MMPs). In this article, we identify membrane-type 6 (MT6) MMP (also known as MMP25) as a proteinase responsible for CD16 downmodulation. IL-2-induced upregulation of MT6/MMP25 cell-surface expression correlates with CD16 downmodulation. MT6/MMP25, sequestered in intracellular compartments in unstimulated NK cells, translocates to the cell surface after stimulation; moreover, it polarizes to the effector-target cell interface of the CD16-mediated immunological synapse. siRNA-mediated disruption of MT6/MMP25 expression enhances the ADCC capacity of NK cells, emphasizing the important functional role of MT6/MMP25 in the regulation of ADCC activity. Thus, this study uncovers a previously unknown role of MT6/MMP25 in human NK cells, and suggests that inhibition of MT6/MMP25 activity could improve ADCC efficacy of therapeutically administered NK cells that require IL-2 for culture and expansion.

Targeted therapy in HER2-positive breast cancer

Treatment options for breast cancer vary based on tumor surface markers and clinical factors, including cytotoxic chemotherapy, hormonal therapy, biological therapy or a combination thereof. An important molecular determinant of therapy is the human epidermal growth factor receptor 2 (HER2) positivity of the tumor, which has been identified in 20-25% of breast cancers and is a prognostic marker of poor outcome. The advent of HER2-targeted therapies has significantly improved the survival of patients with HER2-positive breast cancer. This review focuses on current HER2-targeted therapeutic options for patients with HER2-positive breast cancer, including monoclonal antibodies and tyrosine kinase inhibitors (TKIs).

Psoriasis induced by trastuzumab (herceptin®)

Trastuzumab (Herceptin), a humanized monoclonal antibody, is a cancer drug developed to target the human epidermal receptor (HER) 2, which is overexpressed in some cancer cells. Cutaneous side effects, such as folliculitis, xerosis, and alopecia have not been reported with therapies targeting HER2, in spite of the frequent observances of such with the therapies targeting the epidermal growth factor receptor. We experienced a patient in whom psoriasis was triggered by the trastuzumab treatment for breast cancer. She was a 57-year-old woman with erythematous and scaly plaques occurring a few months after starting trastuzumab, with repeated aggravation after the re-administration of trastuzumab for the breast cancer. Histologic examination showed the typical features of psoriasis with parakeratosis, epidermal hyperplasia, elongation of the rete ridges, and a lymphocytic and polymorphonuclear cell infiltrate in the dermis. To the best of our knowledge, this is the first report of psoriasis triggered by trastuzumab treatment for breast cancer.

Synuclein-γ suppression mediated by RNA interference inhibits the clonogenicity and invasiveness of MCF-7 cells

The aim of the present study was to investigate the effects of synuclein-γ (SNCG) downregulation by RNA interference (RNAi) on the clonogenicity and invasiveness of MCF-7 breast cancer cells. This study used four pairs of SNCG-specific siRNAs which were designed and cloned into the pGPU6 plasmid for introduction into an MCF-7 cell line. The SNCG knockdown efficacies of the four siRNAs were compared using the reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry. The cells' clonogenic and invasive phenotypes were examined with clonogenic and Boyden chamber assays. In comparison with the non-specific siRNA and empty vector controls, all four SNCG siRNAs were observed to significantly inhibit SNCG expression at the mRNA and protein levels (F=481.06, P<0.001; F=147.42, P<0.0001). SNCG suppression mediated by RNAi successfully inhibited the clonogenicity (P=0.002) and invasiveness (P<0.001) of transfected MCF-7 cells. According to the results of the present study, we concluded that SNCG suppression mediated by RNAi significantly suppressed SNCG expression at the mRNA and protein levels, suggesting that SNCG suppression mediated by an RNAi strategy may become a novel approach for treating advanced breast cancer.

Effectiveness of neoadjuvant trastuzumab and chemotherapy in HER2-overexpressing breast cancer

Purpose

Trastuzumab and chemotherapy is the current standard of care in HER2+ early or locally advanced breast cancer, but there are scanty literature data of its real world effectiveness.

Methods

We retrospectively reviewed 205 patients with HER2+ breast cancer diagnosed in 10 Italian Medical Oncology Units between July 2003 and October 2011. All patients received neoadjuvant systemic therapy (NST) with trastuzumab in association with chemotherapy. Many different chemotherapy regimens were used, even if 90 % of patients received schemes including anthracyclines and 99 % received taxanes. NST was administered for more than 21 weeks (median: 24) in 130/205 (63.4 %) patients, while trastuzumab was given for more than 12 weeks (median: 12 weeks) in 101/205 (49.3 %) patients. pCR/0 was defined as ypT0+ypN0, and pCR/is as ypT0/is+ypN0.

Results

pCR/0 was obtained in 24.8 % and pCR/is in 46.8 % of the patients. At multivariate logistic regression, nonluminal/HER2+ tumors (P < 0.0001) and more than 12 weeks of neoadjuvant trastuzumab treatment (P = 0.03) were independent predictors of pCR/0. Median disease-free survival (DFS) and cancer-specific survival (CSS) have not been reached at the time of analysis. At multivariate analysis, nonluminal/HER2+ subclass (DFS: P = 0.01 and CSS: P = 0.01) and pathological stage II–III at surgery (DFS: P < 0.0001 and CSS: P = 0.001) were the only variables significantly associated with a worse long-term outcome.

Conclusions

Our data set the relevance of molecular subclasses and residual tumor burden after neoadjuvant as the most relevant prognostic factors for survival in this cohort of patients.

Systematic analysis of challenge-driven improvements in molecular prognostic models for breast cancer

Although molecular prognostics in breast cancer are among the most successful examples of translating genomic analysis to clinical applications, optimal approaches to breast cancer clinical risk prediction remain controversial. The Sage Bionetworks-DREAM Breast Cancer Prognosis Challenge (BCC) is a crowdsourced research study for breast cancer prognostic modeling using genome-scale data. The BCC provided a community of data analysts with a common platform for data access and blinded evaluation of model accuracy in predicting breast cancer survival on the basis of gene expression data, copy number data, and clinical covariates. This approach offered the opportunity to assess whether a crowdsourced community Challenge would generate models of breast cancer prognosis commensurate with or exceeding current best-in-class approaches. The BCC comprised multiple rounds of blinded evaluations on held-out portions of data on 1981 patients, resulting in more than 1400 models submitted as open source code. Participants then retrained their models on the full data set of 1981 samples and submitted up to five models for validation in a newly generated data set of 184 breast cancer patients. Analysis of the BCC results suggests that the best-performing modeling strategy outperformed previously reported methods in blinded evaluations; model performance was consistent across several independent evaluations; and aggregating community-developed models achieved performance on par with the best-performing individual models.

Overcoming treatment resistance in HER2-positive breast cancer: potential strategies

Human epidermal growth factor receptor (HER)-2 overexpression or amplification occurs in about 20% of all breast cancers and results in a worse prognosis. Nevertheless, anti-HER2 treatments have recently been developed, resulting in dramatic improvements in the clinical outcome of patients with HER2-positive breast cancer. Trastuzumab has shown efficacy in early and advanced breast cancer treatment and lapatinib is currently approved for the treatment of advanced disease. Other anti-HER2 agents are being investigated. Mechanisms of resistance to trastuzumab treatment include crosstalk with heterologous receptors and amplification of HER2 signalling; amplification of the phosphoinositide 3-kinase (PI3K)/AKT pathway; alteration in binding of trastuzumab to HER2; and loss of HER2 expression. Proposed mechanisms of resistance to lapatinib involve derepression and/or activation of compensatory survival pathways through increased PI3K/AKT or estrogen receptor (ER) signalling. Several strategies to overcome resistance to anti-HER2 treatment are in different phases of development and include treatment with pertuzumab, T-DM1 and mammalian target of rapamycin (mTOR) inhibitors.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.