Anti-vascular endothelial growth factor therapy in breast cancer

Recent updates on potential of VEGFR-2 small-molecule inhibitors as anticancer agents

The vascular endothelial growth factor receptor (VEGFR) system is the key component for controlling angiogenesis in cancer cells. Blocking vascular endothelial growth factor receptor 2 (VEGFR2) signalling is one of the most promising approaches to hindering angiogenesis and the subsequent growth of cancer cells. The USFDA-approved small-molecule drugs targeting VEGFR-2 are developing drug resistance over the course of chemotherapy, and cardiac-related side effects are consistently being reported; hence, there is an urgent need for more safe and effective anticancer molecules. The present review focuses on the structure and physiology of VEGFR-2 and its involvement in the progression of cancer cells. The recent updates from the last five years through papers and patents on structure-activity relationships, pharmacophoric attributes, molecular docking interactions, antiangiogenic assays, cancer cell line studies, and the potencies (IC50) of VEGFR-2 inhibitors are discussed herein. The common structural framework requirements, such as the Asp-Phe-Gly (DFG) motif of VEGFR-2 interacting with the HBD-HBA region in the ligand molecules, the central aryl ring occupying the linker region, and a variety of bio-isosteres, can enhance activity against VEGFR-2. At one end, the heteroaryl moiety is essential for interaction within the ATP-binding site of VEGFR-2, while the terminal hydrophobic tail occupies the allosteric binding site. Three to five bond spacers between the heteroaryl and HBD-HBA regions provided a better result towards VEGFR-2 inhibition, mirroring the behaviors of standard drugs. The in-depth analysis of recent updates on VEGFR-2 inhibitors presented in this paper will help prospective synthetic and medicinal chemists to discover new lead molecules for the treatment of various cancers.

NDRGs in Breast Cancer: A Review and In Silico Analysis

The N-myc downstream regulated gene family (NDRGs) includes four members: NDRG1, NDRG2, NDRG3, and NDRG4. These members exhibit 53-65% amino acid identity. The role of NDRGs in tumor growth and metastasis appears to be tumor- and context-dependent. While many studies have reported that these family members have tumor suppressive roles, recent studies have demonstrated that NDRGs, particularly NDRG1 and NDRG2, function as oncogenes, promoting tumor growth and metastasis. Additionally, NDRGs are involved in regulating different signaling pathways and exhibit diverse cellular functions in breast cancers. In this review, we comprehensively outline the oncogenic and tumor suppressor roles of the NDRG family members in breast cancer, examining evidence from in vitro and in vivo breast cancer models as well as tumor tissues from breast cancer patients. We also present analyses of publicly available genomic and transcriptomic data from multiple independent cohorts of breast cancer patients.

Vascular Endothelial Growth Factor Ligands and Receptors in Breast Cancer

Breast cancer (BC) is the most common malignancy responsible for the largest number of deaths in women worldwide. The risk of developing BC is predisposed by many factors such as age, presence of genetic mutations or body weight. The diagnosis is mostly made relatively late, which is why patients are exposed to radical surgical treatments, long-term chemotherapy and lower survival rates. There are no sufficiently sensitive and specific screening tests; therefore, researchers are still looking for new diagnostic biomarkers that would indicate the appearance of neoplastic changes in the initial stage of neoplasm. The VEGF family of proteins (VEGF-A, VEGF-B, VEGF-C, VEGF-D, EG-VEGF, PlGF) and their receptors are significant factors in the pathogenesis of BC. They play a significant role in the process of angiogenesis and lymphangiogenesis in both physiological and pathological conditions. The usefulness of these proteins as potential diagnostic biomarkers has been initially proven. Moreover, the blockage of VEGF-related pathways seems to be a valid therapeutic target. Recent studies have tried to describe novel strategies, including targeting pericytes, use of miRNAs and extracellular tumor-associated vesicles, immunotherapeutic drugs and nanotechnology. This indicates their possible contribution to the formation of breast cancer and their usefulness as potential biomarkers and therapeutic targets.

The role of Th-17 cells and IL-17 in the metastatic spread of breast cancer: As a means of prognosis and therapeutic target

Metastatic breast cancer is one of the most common and well-known causes of death for women worldwide. The inflammatory tumor cell and other cancer hallmarks dictate the metastatic form and dissemination of breast cancer. Taking these into account, from various components of the tumor microenvironment, a pro-inflammatory infiltrative cell known as Th-17 plays an immense role in breast cancer proliferation, invasiveness, and metastasis. It has been demonstrated that IL-17, a pleiotropic pro-inflammatory cytokine generated by Th-17, is upregulated in a metastatic form of breast cancer. Recent research updates stated that chronic inflammation and mediators like cytokines and chemokines are causative hallmarks in many human cancers, including breast cancer. Therefore, IL-17 and its multiple downward signaling molecules are the centers of research attention to develop potent treatment options for cancer. They provide information on the role of IL-17-activated MAPK, which results in tumor cell proliferation and metastasis via NF-kB-mediated expression of MMP signaling. Overall, this review article emphasizes IL-17A and its intermediate signaling molecules, such as ERK1/2, NF-kB, MMPs, and VEGF, as potential molecular targets for the prevention and treatment of breast cancer.

Capturing the spatial and temporal dynamics of tumor stroma for on-chip optimization of microenvironmental targeting nanomedicine

Malignant cells grow in a complex microenvironment that plays a key role in cancer progression. The "dynamic reciprocity" existing between cancer cells and their microenvironment is involved in cancer differentiation, proliferation, invasion, metastasis, and drug response. Therefore, understanding the molecular mechanisms underlying the crosstalk between cancer cells and their surrounding tissue (i.e., tumor stroma) and how this interplay affects the disease progression is fundamental to design and validate novel nanotherapeutic approaches. As an important regulator of tumor progression, metastasis and therapy resistance, the extracellular matrix of tumors, the acellular component of the tumor microenvironment, has been identified as very promising target of anticancer treatment, revolutionizing the traditional therapeutic paradigm that sees the neoplastic cells as the preferential objective to fight cancer. To design and to validate such a target therapy, advanced 3D preclinical models are necessary to correctly mimic the complex, dynamic and heterogeneous tumor microenvironment. In addition, the recent advancement in microfluidic technology allows fine-tuning and controlling microenvironmental parameters in tissue-on-chip devices in order to emulate the in vivo conditions. In this review, after a brief description of the origin of tumor microenvironment heterogeneity, some examples of nanomedicine approaches targeting the tumor microenvironment have been reported. Further, how advanced 3D bioengineered tumor models coupled with a microfluidic device can improve the design and testing of anti-cancer nanomedicine targeting the tumor microenvironment has been discussed. We highlight that the presence of a dynamic extracellular matrix, able to capture the spatiotemporal heterogeneity of tumor stroma, is an indispensable requisite for tumor-on-chip model and nanomedicine testing.

Prostate Cancer Tumor Stroma: Responsibility in Tumor Biology, Diagnosis and Treatment

Simple Summary

The crosstalk between prostate stroma and its epithelium is essential to tissue homeostasis. Likewise, reciprocal signaling between tumor cells and the stromal compartment is required in tumor progression to facilitate or stimulate key processes such as cell proliferation and invasion. The aim of the present work was to review the current state of knowledge on the significance of tumor stroma in the genesis, progression and therapeutic response of prostate carcinoma. Additionally, we addressed the future therapeutic opportunities.

Abstract

Prostate cancer (PCa) is a common cancer among males globally, and its occurrence is growing worldwide. Clinical decisions about the combination of therapies are becoming highly relevant. However, this is a heterogeneous disease, ranging widely in prognosis. Therefore, new approaches are needed based on tumor biology, from which further prognostic assessments can be established and complementary strategies can be identified. The knowledge of both the morphological structure and functional biology of the PCa stroma compartment can provide new diagnostic, prognostic or therapeutic possibilities. In the present review, we analyzed the aspects related to the tumor stromal component (both acellular and cellular) in PCa, their influence on tumor behavior and the therapeutic response and their consideration as a new therapeutic target.

Breast Cancer-Epidemiology, Classification, Pathogenesis and Treatment (Review of Literature)

Breast cancer is the most-commonly diagnosed malignant tumor in women in the world, as well as the first cause of death from malignant tumors. The incidence of breast cancer is constantly increasing in all regions of the world. For this reason, despite the progress in its detection and treatment, which translates into improved mortality rates, it seems necessary to look for new therapeutic methods, and predictive and prognostic factors. Treatment strategies vary depending on the molecular subtype. Breast cancer treatment is multidisciplinary; it includes approaches to locoregional therapy (surgery and radiation therapy) and systemic therapy. Systemic therapies include hormone therapy for hormone-positive disease, chemotherapy, anti-HER2 therapy for HER2-positive disease, and quite recently, immunotherapy. Triple negative breast cancer is responsible for more than 15-20% of all breast cancers. It is of particular research interest as it presents a therapeutic challenge, mainly due to its low response to treatment and its highly invasive nature. Future therapeutic concepts for breast cancer aim to individualize therapy and de-escalate and escalate treatment based on cancer biology and early response to therapy. The article presents a review of the literature on breast carcinoma-a disease affecting women in the world.

Relationship between VEGF Family Members, Their Receptors and Cell Death in the Neoplastic Transformation of Colorectal Cancer

Colorectal cancer (CRC) is the second most common cause of cancer death in the world. Both modifiable and nonmodifiable risk factors play a significant role in the pathogenesis of this tumor. The diagnosis is usually made late due to limitations of screening tests; therefore, the scientists are looking for new diagnostic tools such as gene or miRNA expression or different proteins’ concentrations, e.g., vascular endothelial growth factor (VEGF) family members. The VEGF family (VEGF-A, VEGF-B, VEGF-C, VEGF-D and PlGF) plays a key role in the processes of blood vessel formation in embryonic development as well as in pathological angiogenesis and lymphangiogenesis, which allow the tumor to grow exponentially. Blockage of VEGF-related pathways seems to be a valid therapeutic target. It was suggested in recent studies, that besides already used drugs, e.g., bevacizumab, there are other agents with potential usefulness in anticancer activity such as miRNAs, TMEA, granzyme K, baicalein and arginine. Moreover, VEGF proteins were assessed to induce the expression of anti-apoptotic proteins such as BCL-2 and BAX. Therefore, investigations concerning the usefulness of VEGF family members, not only in the development but also in the therapy of CRC, in order to fully elucidate their role in carcinogenesis, are extremely important.

IQ Motif-Containing GTPase-Activating Protein 2 Inhibits Breast Cancer Angiogenesis By Suppressing VEGFR2-AKT Signaling

Antiangiogenesis cancer therapies are facing setbacks due to side effects and resistance. Parallel targeting of multiple pathways can help in the development of more effective therapies. This requires the discovery of new molecules that can regulate multiple cellular processes. Our study has recently established the association of reduced IQGAP2 expression in breast cancer with EMT and poor prognosis of the patient. Existing literature indirectly suggests the role of IQGAP2 in angiogenesis that is still unexplored. In this study, we searched the role of IQGAP2 in tumor angiogenesis in a comprehensive manner using cell culture, patients, and animal models. Depletion of IQGAP2 in breast cancer cells increased proliferation, migration, and tubulogenesis of HUVECs. Findings were validated in ex ovo CAM, Matrigel plug and skin wound-healing assays in mouse model, showing that the reduction of IQGAP2 significantly increased angiogenesis. As a confirmation, IHC analysis of the patient's tissues showed a negative correlation of IQGAP2 expression with the microvessel density. Mechanistically, loss of IQGAP2 appeared to activate VEGF-A via ERK activation in tumor cells, which activated the VEGFR2-AKT axis in HUVECs. IMPLICATIONS: The findings of this study suggest the antiangiogenic properties of IQGAP2 in breast cancer. The Dual effect of IQGAP2 on EMT and angiogenesis makes it a potential target for anticancer therapy.

Early Imaging and Molecular Changes with Neoadjuvant Bevacizumab in Stage II/III Breast Cancer

This prospective, phase II study evaluated novel biomarkers as predictors of response to bevacizumab in patients with breast cancer (BC), using serial imaging methods and gene expression analysis. Patients with primary stage II/III BC received bevacizumab 15 mg/kg (cycle 1; C1), then four cycles of neoadjuvant docetaxel doxorubicin, and bevacizumab every 3 weeks (C2-C5). Tumour proliferation and hypoxic status were evaluated using 18F-fluoro-3'-deoxy-3'-L-fluorothymidine (FLT)- and 18F-fluoromisonidazole (FMISO)-positron emission tomography (PET) at baseline, and during C1 and C5. Pre- and post-bevacizumab vascular changes were evaluated using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Molecular biomarkers were assessed using microarray analysis. A total of 70 patients were assessed for treatment efficacy. Significant decreases from baseline in tumour proliferation (FLT-PET), vascularity, and perfusion (DCE-MRI) were observed during C1 (p ≤ 0.001), independent of tumour subtype. Bevacizumab treatment did not affect hypoxic tumour status (FMISO-PET). Significant changes in the expression of 28 genes were observed after C1. Changes in vascular endothelial growth factor receptor (VEGFR)-2p levels were observed in 65 patients, with a > 20% decrease in VEGFR-2p observed in 13/65. Serial imaging techniques and molecular gene profiling identified several potentially predictive biomarkers that may predict response to neoadjuvant bevacizumab therapy in BC patients.

Alterations of Growth and Focal Adhesion Molecules in Human Breast Cancer Cells Exposed to the Random Positioning Machine

In this study, we evaluated changes in focal adhesions (FAs) in two types of breast cancer cell (BCC) lines (differentiated MCF-7 and the triple-negative MDA-MB-231 cell line) exposed to simulated microgravity (s-μg) created by a random positioning machine (RPM) for 24 h. After exposure, the BCC changed their growth behavior and exhibited two phenotypes in RPM samples: one portion of the cells grew as a normal two-dimensional monolayer [adherent (AD) BCC], while the other portion formed three-dimensional (3D) multicellular spheroids (MCS). After 1 h and 30 min (MDA-MB-231) and 1 h 40 min (MCF-7), the MCS adhered completely to the slide flask bottom. After 2 h, MDA-MB-231 MCS cells started to migrate, and after 6 h, a large number of the cells had left the MCS and continued to grow in a scattered pattern, whereas MCF-7 cells were growing as a confluent monolayer after 6 h and 24 h. We investigated the genes associated with the cytoskeleton, the extracellular matrix and FAs. ACTB, TUBB, FN1, FAK1, and PXN gene expression patterns were not significantly changed in MDA-MB-231 cells, but we observed a down-regulation of LAMA3, ITGB1 mRNAs in AD cells and of ITGB1, TLN1 and VCL mRNAs in MDA-MB-231 MCS. RPM-exposed MCF-7 cells revealed a down-regulation in the gene expression of FAK1, PXN, TLN1, VCL and CDH1 in AD cells and PXN, TLN and CDH1 in MCS. An interaction analysis of the examined genes involved in 3D growth and adhesion indicated a central role of fibronectin, vinculin, and E-cadherin. Live cell imaging of eGFP-vinculin in MCF-7 cells confirmed these findings. β-catenin-transfected MCF-7 cells revealed a nuclear expression in 1g and RPM-AD cells. The target genes BCL9, MYC and JUN of the Wnt/β-catenin signaling pathway were differentially expressed in RPM-exposed MCF-7 cells. These findings suggest that vinculin and β-catenin are key mediators of BCC to form MCS during 24 h of RPM-exposure.

Numerical evaluation reveals the effect of branching morphology on vessel transport properties during angiogenesis

Blood flow governs transport of oxygen and nutrients into tissues. Hypoxic tissues secrete VEGFs to promote angiogenesis during development and in tissue homeostasis. In contrast, tumors enhance pathologic angiogenesis during growth and metastasis, suggesting suppression of tumor angiogenesis could limit tumor growth. In line with these observations, various factors have been identified to control vessel formation in the last decades. However, their impacts on the vascular transport properties of oxygen remain elusive. Here, we take a computational approach to examine the effects of vascular branching on blood flow in the growing vasculature. First of all, we reconstruct a 3D vascular model from the 2D confocal images of the growing vasculature at postnatal day 5 (P5) mouse retina, then simulate blood flow in the vasculatures, which are obtained from the gene targeting mouse models causing hypo- or hyper-branching vascular formation. Interestingly, hyper-branching morphology attenuates effective blood flow at the angiogenic front, likely promoting tissue hypoxia. In contrast, vascular hypo-branching enhances blood supply at the angiogenic front of the growing vasculature. Oxygen supply by newly formed blood vessels improves local hypoxia and decreases VEGF expression at the angiogenic front during angiogenesis. Consistent with the simulation results indicating improved blood flow in the hypo-branching vasculature, VEGF expression around the angiogenic front is reduced in those mouse retinas. Conversely, VEGF expression is enhanced in the angiogenic front of hyper-branching vasculature. Our results indicate the importance of detailed flow analysis in evaluating the vascular transport properties of branching morphology of the blood vessels.

Blood vessels are important for the transport of various substances, such as oxygen, nutrients, and cells, to the entire body. Control of blood vessel formation is thought to be important in health and disease. In the last decades, various factors which regulate blood vessel branching morphology have been identified. Gene modification of some of these identified factors results in hyper-branching of the vasculature while others cause hypo-branching of the vessel. Given the importance of the transport property of the blood vessel, it is important to examine the effect of these identified factors on the transport property of the affected vascular morphology. In line with these facts, we reconstruct 3D vessel structures from 2D confocal microscopy images. We then numerically simulate blood flow in the structures. Interestingly, our results suggest vessel network complexity negatively affects the blood perfusion efficiency and tissue oxygenation during angiogenesis. Thus, our results highlight the importance of flow analysis considering the detailed 3D branching pattern of the vascular network to quantitatively evaluate its transport properties.

Design, synthesis and biological evaluation of a new thieno[2,3-d]pyrimidine-based urea derivative with potential antitumor activity against tamoxifen sensitive and resistant breast cancer cell lines

Breast cancer (BC) and endocrine resistance to chemotherapy are challenging problems where angiogenesis plays fundamental roles. Thus, targeting of VEGFR-2 signalling pathway has been an attractive approach. In this study, we synthesised a new sorafenib analogue, thieno[2,3-d]pyrimidine based urea derivative, KM6. It showed 65% inhibition of VEGF2 tyrosine kinase activity and demonstrated a potential antitumor activity in TAM-resistant, LCC2, and its parental MCF7 BC cells. KM6 retained the sensitivity of LCC2 through upregulation of key enzymes of apoptosis and proteins of cell death including caspases 3, 8, 9, P53, BAX/BCL-2 ratio and LDH in media. It downregulated mRNA expression of Ki-67, survivin, Akt, and reduced levels of ROS and glucose uptake. Moreover, KM6 reduced the levels of inflammation markers PGE2, COX2, IL-1β and IL6 and metastasis markers MMP-2 and MMP-9. In conclusion, KM6 is a promising compound for ER + and TAM-resistant BC with many potential antitumor and polypharmacological mechanisms.

Understanding Breast cancer: from conventional therapies to repurposed drugs

Breast cancer is the most common cancer among women and is considered a developed country disease. Moreover, is a heterogenous disease, existing different types and stages of breast cancer development, therefore, better understanding of cancer biology, helps to improve the development of therapies. The conventional treatments accessible after diagnosis, have the main goal of controlling the disease, by improving survival. In more advance stages the aim is to prolong life and symptom palliation care. Surgery, radiation therapy and chemotherapy are the main options available, which must be adapted to each person individually. However, patients are developing resistance to the conventional therapies. This resistance is due to alterations in important regulatory pathways such as PI3K/AKt/mTOR, this pathway contributes to trastuzumab resistance, a reference drug to treat breast cancer. Therefore, is proposed the repurposing of drugs, instead of developing drugs de novo, for example, to seek new medical treatments within the drugs available, to be used in breast cancer treatment. Providing safe and tolerable treatments to patients, and new insights to efficacy and efficiency of breast cancer treatments. The economic and social burden of cancer is enormous so it must be taken measures to relieve this burden and to ensure continued access to therapies to all patients. In this review we focus on how conventional therapies against breast cancer are leading to resistance, by reviewing those mechanisms and discussing the efficacy of repurposed drugs to fight breast cancer.

Angiogenesis in Breast Cancer Progression, Diagnosis, and Treatment

Angiogenesis is a significant event in a wide range of healthy and diseased conditions. This process frequently involves vasodilation and an increase in vascular permeability. Numerous players referred to as angiogenic factors, work in tandem to facilitate the outgrowth of endothelial cells (EC) and the consequent vascularity. Conversely, angiogenic factors could also feature in pathological conditions. Angiogenesis is a critical factor in the development of tumors and metastases in numerous cancers. An increased level of angiogenesis is associated with decreased survival in breast cancer patients. Therefore, a good understanding of the angiogenic mechanism holds a promise of providing effective treatments for breast cancer progression, thereby enhancing patients' survival. Disrupting the initiation and progression of this process by targeting angiogenic factors such as vascular endothelial growth factor (Vegf)-one of the most potent member of the VEGF family- or by targeting transcription factors, such as Hypoxia-Inducible Factors (HIFs) that act as angiogenic regulators, have been considered potential treatment options for several types of cancers. The objective of this review is to highlight the mechanism of angiogenesis in diseases, specifically its role in the progression of malignancy in breast cancer, as well as to highlight the undergoing research in the development of angiogenesis-targeting therapies.

Design of Anti-Angiogenic Peptidomimetics and Evaluation their Biological Activity by In Vitro Assays

BACKGROUND

One of the important therapeutic approaches in cancer field is development of compounds which can block the initial tumor growth and the progression of tumor metastasis with no side effects. Thus, the recent study was carried out to design anti-VEGFR2-peptidomimetics as the most significant factor of angiogenesis process- and evaluate their biological activity by in vitro assays.

METHODS

We designed anti-VEGFR2 peptidomimetics with anti-angiogenic activity, including compound P (lactam derivative) and compound T (indole derivative) by using in silico methods. Then, the inhibitory activity on angiogenesis was evaluated by using angiogenesis specific assays such as Human Umbilical Vein Endothelial Cell (HUVEC) proliferation, tube formation in Matrigel, MTT and Real-Time PCR. IC50 values of the compounds were also determined by cytotoxicity plot in MTT assay.

RESULTS

Compounds P and T inhibited HUVEC cell proliferation and viability in a dose-dependent manner. The IC50 for compound T and compound P in HUVEC cell line were 113 and 115 μg/ml, respectively. Tube formation assay revealed that both compounds can inhibit angiogenesis effectively. The results of Real-Time PCR also showed these compounds are able to inhibit the expression of CD31 gene in HUVEC cell line.

CONCLUSION

Our study suggested that compounds P and T may act as therapeutic molecules, or lead compounds for development of angiogenesis inhibitors in VEGF-related diseases.

Short-Term Microgravity Influences Cell Adhesion in Human Breast Cancer Cells

With the commercialization of spaceflight and the exploration of space, it is important to understand the changes occurring in human cells exposed to real microgravity (r-µg) conditions. We examined the influence of r-µg, simulated microgravity (s-µg, incubator random positioning machine (iRPM)), hypergravity (hyper-g), and vibration (VIB) on triple-negative breast cancer (TNBC) cells (MDA-MB-231 cell line) with the aim to study early changes in the gene expression of factors associated with cell adhesion, apoptosis, nuclear factor "kappa-light-chain-enhancer" of activated B-cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling. We had the opportunity to attend a parabolic flight (PF) mission and to study changes in RNA transcription in the MDA-MB cells exposed to PF maneuvers (29th Deutsches Zentrum für Luft- und Raumfahrt (DLR) PF campaign). PF maneuvers induced an early up-regulation of ICAM1, CD44 and ERK1 mRNAs after the first parabola (P1) and a delayed upregulation of NFKB1, NFKBIA, NFKBIB, and FAK1 after the last parabola (P31). ICAM-1, VCAM-1 and CD44 protein levels were elevated, whereas the NF-κB subunit p-65 and annexin-A2 protein levels were reduced after the 31st parabola (P31). The PRKCA, RAF1, BAX mRNA were not changed and cleaved caspase-3 was not detectable in MDA-MB-231 cells exposed to PF maneuvers. Hyper-g-exposure of the cells elevated the expression of CD44 and NFKBIA mRNAs, iRPM-exposure downregulated ANXA2 and BAX, whereas VIB did not affect the TNBC cells. The early changes in ICAM-1 and VCAM-1 and the rapid decrease in the NF-κB subunit p-65 might be considered as fast-reacting, gravity-regulated and cell-protective mechanisms of TNBC cells exposed to altered gravity conditions. This data suggest a key role for the detected gravity-signaling elements in three-dimensional growth and metastasis.

Tyrosine Kinase Inhibitor-Induced Hypertension: Role of Hypertension as a Biomarker in Cancer Treatment

:

Cancer treatment is an area of continuous improvement. Therapy is becoming more targeted and the use of anti-angiogenic agents in multiple cancers, specifically tyrosine kinase inhibitors (TKIs), has demonstrated prolonged survival outcomes compared with previous drugs. Therefore, they have become a well-established part of the treatment.

:

Despite good results, there is a broad range of moderate to severe adverse effects associated with treatment. Hypertension (HTN) is one of the most frequent adverse effects and has been associated with favourable outcomes (in terms of cancer treatment) of TKI treatment.

:

High blood pressure is considered a class effect of TKI treatment, although the mechanisms have not been fully described. Three current hypotheses of TKI-associated HTN are highlighted in this narrative review. These include nitric oxide decrease, a change in endothelin-1 levels and capillary rarefaction.

:

Several studies have investigated HTN as a potential biomarker of TKI efficacy. HTN is easy to measure and adding this factor to prognostic models has been shown to improve specificity. HTN may become a potential biomarker in clinical practice involving treating advanced cancers. However, data are currently limited by the number of studies and knowledge of the mechanism of action.

Magnusson N. Drug-Induced Hypertension Caused by Multikinase Inhibitors (Sorafenib, Sunitinib, Lenvatinib and Axitinib) in Renal Cell Carcinoma Treatment

This paper reviews current treatments for renal cell carcinoma/cancer (RCC) with the multikinase inhibitors (MKIs) sorafenib, sunitinib, lenvatinib and axitinib. Furthermore, it compares these drugs regarding progression-free survival, overall survival and adverse effects (AE), with a focus on hypertension. Sorafenib and sunitinib, which are included in international clinical guidelines as first- and second-line therapy in metastatic RCC, are now being challenged by new-generation drugs like lenvatinib and axitinib. These drugs have shown significant clinical benefits for patients with RCC, but all four induce a variety of AEs. Hypertension is one of the most common AEs related to MKI treatment. Comparing sorafenib, sunitinib and lenvatinib revealed that sorafenib and sunitinib had the same efficacy, but sorafenib was safer to use. Lenvatinib showed better efficacy than sorafenib but worse safety. No trials have yet been completed that compare lenvatinib with sunitinib. Although axitinib promotes slightly higher hypertension rates compared to sunitinib, the overall discontinuation rate and cardiovascular complications are favourable. Although the mean rate of patients who develop hypertension is similar for each drug, some trials have shown large differences, which could indicate that lifestyle and/or genetic factors play an additional role.

Pilot study of bevacizumab in combination with docetaxel and cyclophosphamide as adjuvant treatment for patients with early stage HER-2 negative breast cancer, including analysis of candidate circulating markers of cardiac toxicity: ICORG 08-10 trial

Background:

Combining bevacizumab and chemotherapy produced superior response rates compared with chemotherapy alone in metastatic breast cancer. As bevacizumab may cause hypertension (HTN) and increase the risk of cardiac failure, we performed a pilot study to evaluate the feasibility and toxicity of a non-anthracycline-containing combination of docetaxel with cyclophosphamide and bevacizumab in early stage breast cancer patients.

Methods:

Treatment consisted of four 3-weekly cycles of docetaxel and cyclophosphamide (75/600 mg/m²). Bevacizumab was administered 15 mg/kg intravenously on day 1, and then every 3 weeks to a total of 18 cycles of treatment. Serum biomarker concentrations of vascular endothelial growth factor (VEGF), cardiac troponin-I (cTnI), myeloperoxidase (MPO), and placental growth factor (PlGF) were quantified using enzyme-linked immunosorbent assay (ELISA) in 62 patients at baseline and whilst on treatment to determine their utility as biomarkers of cardiotoxicity, indicated by left ventricular ejection fraction (LVEF).

Results:

A total of 106 patients were accrued in nine sites. Median follow up was 65 months (1–72 months). Seventeen protocol-defined relapse events were observed, accounting for an overall disease-free survival (DFS) rate of 84%. The DFS rates for hormone receptor positive (HR+) and triple-negative (TN) patients were 95% versus 43%, respectively. The median time to relapse was 25 (12–54) months in TN patients versus 38 (22–71) months in HR+ patients. There have been 13 deaths related to breast cancer . The overall survival (OS) rate was 88%. The 5-year OS rate in HR+ versus TN was 95% versus 57%. None of the measured biomarkers predicted the development of cardiotoxicity.

Conclusions:

We observed a low relapse rate in node-positive, HR+ patients; however, results in TN breast cancer were less encouraging. Given the negative results of three large phase III trials, it is unlikely that this approach will be investigated further.

Trial Registration

ClinicalTrials.gov Identifier: NCT00911716.

Development of a Biocompatible Copolymer Nanocomplex to Deliver VEGF siRNA for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is the most difficult breast cancer subtype to treat. TNBC patients have significantly higher expression of vascular endothelial growth factor (VEGF) in tumors compared to non-TNBC patients. VEGF not only exerts its pro-angiogenic effects on endothelial cells but also acts as a survival and autocrine growth factor for VEGF receptor (VEGFR) expressing cancer cells. Silencing the expression of VEGF is therefore a potential therapy for TNBC.

Methods: A novel biocompatible linear copolymer poly[bis(ε-Lys-PEI)Glut-PEG] (PLEGP) was developed to deliver VEGF siRNA for TNBC therapy. The copolymer is composed of lysine and glutaric acid, a natural metabolite of amino acids in the body. Low-molecular weight polyethyleneimine (PEI) was grafted to the copolymer to efficiently condense siRNA into nanocomplex without inducing cytotoxicity. Various in vitro studies were performed to evaluate the stability, cellular uptake, tumor penetration, and biological activities of the VEGF siRNA nanocomplex. The anti-tumor activities of the nanocomplex was also evaluated in an orthotopic TNBC mouse model.

Results: PEIs with different molecular weights were evaluated, and the copolymer PLEGP₁₈₀₀ was able to easily form a stable nanocomplex with siRNAs and protect them from serum degradation. The siRNA/PLEGP₁₈₀₀ nanocomplex exhibited negligible cytotoxicity but showed high cellular uptake, high transfection efficiency, and high tumor penetration. In vitro activity studies showed that the siRNA nanocomplex significantly inhibited migration and invasion of TNBC cells. Moreover, the VEGF siRNA nanocomplex efficiently inhibited tumor growth in an orthotopic TNBC mouse model and down-regulated VEGF expression in the tumor.

Conclusion: PLEGP₁₈₀₀ is a safe and efficient copolymer to deliver siRNAs for TNBC therapy. It could potentially be applied to other cancers by changing the cargo and incorporating tumor-specific ligands.

Breast Cancer Tumor Stroma: Cellular Components, Phenotypic Heterogeneity, Intercellular Communication, Prognostic Implications and Therapeutic Opportunities

Although the mechanisms underlying the genesis and progression of breast cancer are better understood than ever, it is still the most frequent malignant tumor in women and one of the leading causes of cancer death. Therefore, we need to establish new approaches that lead us to better understand the prognosis of this heterogeneous systemic disease and to propose new therapeutic strategies. Cancer is not only a malignant transformation of the epithelial cells merely based on their autonomous or acquired proliferative capacity. Today, data support the concept of cancer as an ecosystem based on a cellular sociology, with diverse components and complex interactions between them. Among the different cell types that make up the stroma, which have a relevant role in the dynamics of tumor/stromal cell interactions, the main ones are cancer associated fibroblasts, endothelial cells, immune cells and mesenchymal stromal cells. Several factors expressed by the stroma of breast carcinomas are associated with the development of metastasis, such as matrix metalloproteases, their tissular inhibitors or some of their regulators like integrins, cytokines or toll-like receptors. Based on the expression of these factors, two types of breast cancer stroma can be proposed with significantly different influence on the prognosis of patients. In addition, there is evidence about the existence of bi-directional signals between cancer cells and tumor stroma cells with prognostic implications, suggesting new therapeutic strategies in breast cancer.

Co-Expression of VEGF and IL-6 Family Cytokines is Associated with Decreased Survival in HER2 Negative Breast Cancer Patients: Subtype-Specific IL-6 Family Cytokine-Mediated VEGF Secretion

Breast cancer cell-response to inflammatory cytokines such as interleukin-6 (IL-6) and oncostatin M (OSM) may affect the course of clinical disease in a cancer subtype-dependent manner. Furthermore, vascular endothelial growth factor A (VEGF) secretion induced by IL-6 and OSM may also be subtype-dependent. Utilizing datasets from Oncomine, we show that poor survival of invasive ductal carcinoma (IDC) breast cancer patients is correlated with both high VEGF expression and high cytokine or cytokine receptor expression in tumors. Importantly, epidermal growth factor receptor-negative (HER2-), but not HER2-positive (HER2+), patient survival is significantly lower with high tumor co-expression of VEGF and OSM, OSMRβ, IL-6, or IL-6Rα compared to low co-expression. Furthermore, assessment of HER2- breast cancer cells in vitro identified unique signaling differences regulating cytokine-induced VEGF secretion. The levels of VEGF secretion were analyzed by ELISA with siRNAs for hypoxia inducible factor 1 α (HIF1α) and signal transducer and activator of transcription 3 (STAT3). Specifically, we found that estrogen receptor-negative (ER-) MDA-MB-231 cells respond only to OSM through STAT3 signaling, while ER+ T47D cells respond to both OSM and IL-6, though to IL-6 to a lesser extent. Additionally, in the ER+ T47D cells, OSM signals through both STAT3 and HIF1α. These results highlight that the survival of breast cancer patients with high co-expression of VEGF and IL-6 family cytokines is dependent on breast cancer subtype. Thus, the heterogeneity of human breast cancer in relation to IL-6 family cytokines and VEGF may have important implications in clinical treatment options, disease progression, and ultimately patient prognosis.

Recapitulating spatiotemporal tumor heterogeneity in vitro through engineered breast cancer microtissues

Tumor and microenvironmental heterogeneity hinders the study of breast cancer biology and the assessment of therapeutic strategies, being associated with high variability and drug resistance. In this context, it is mandatory to develop three-dimensional breast tumor models able to reproduce this heterogeneity and the dynamic interaction occurring between tumor cells and microenvironment. Here we show a new breast cancer microtissue model (T-µTP) uniquely able to present intra-tumor morphological heterogeneity in a dynamic and responsive endogenous matrix. T-µTP consists of adenocarcinoma cells, endothelial cells and stromal fibroblasts. These three kinds of cells are totally embedded into an endogenous matrix which is rich in collagen and hyaluronic acid and it is directly produced by human fibroblasts. In this highly physiologically relevant environment, tumor cells evolve in different cluster morphologies recapitulating tumor spatiotemporal heterogeneity. Moreover they activate the desmoplastic and vascular reaction with affected collagen content, assembly and organization and the presence of aberrant capillary-like structures (CLS). Thus, T-µTP allows to outline main crucial events involved in breast cancer progression into a single model overcoming the limit of artificial extra cellular matrix surrogates. We strongly believe that T-µTP is a suitable model for the study of breast cancer and for drug screening assays following key parameters of clinical interest.

STATEMENT OF SIGNIFICANCE

Tumor and microenvironmental heterogeneity makes very hurdle to find a way to study and treat breast cancer. Here we develop an innovative 3D tumor microtissue model recapitulating in vitro tumor heterogeneity. Tumor microtissues are characterized by the activation of the stromal and vascular reaction too. We underline the importance to mimic different microenvironmental tumor features in the same time and in a single tissue in order to obtain a model of spatiotemporal tumor genesis and progression, suitable for the study of tumor treatment and resistance.

Advancing Immunotherapy in Metastatic Breast Cancer

OPINION STATEMENT

Despite many advances in the treatment of breast cancer, the development of metastatic disease remains an incurable and frequent cause of cancer death for women worldwide. An improved understanding of the role of host immunosurveillance in modulating breast cancer disease biology, as well as impressive survival benefits seen to checkpoint blockade in other malignancies have provided great hope for an expanding role of immunotherapies in breast cancer management. While these novel therapies are currently being investigated in clinical trials, signals of efficacy, and tolerability in early phase studies suggest these will eventually make their way into standard practice algorithms. Ongoing research has highlighted a high degree of intertumoural heterogeneity in tumour lymphocytic infiltrates, suggesting some tumours or subtypes are more immunogenic than others. Furthermore, tumour intrinsic mechanisms of immune evasion are beginning to be uncovered, potentially representing key therapeutic targets to use in combination with checkpoint blockade, exemplifying the emerging concept of personalised medicine approaches to immune therapies. Subsequently, different immunotherapeutic strategies may be required based on stratification by these factors-for the minority of tumours with a high level of pre-existing immunity, immune checkpoint blockade monotherapy may be sufficient. However, for the majority of tumours with lower levels of pre-existing immunity, combination approaches will likely be required to achieve maximal therapeutic effect. Results of ongoing clinical trials including combinations with chemotherapy, radiation therapy, and targeted therapies are eagerly awaited.

Prognostic evaluation of VEGFA genotypes and haplotypes in a cohort of Brazilian women with non metastatic breast cancer

Vascular Endothelial Growth Factor (VEGF) mediates angiogenesis, which is crucial for tumor development and progression. The present study aimed to evaluate the impact of VEGFA gene polymorphisms rs699947, rs833061, rs1570360, rs2010963 and rs3025039 on breast cancer features and prognosis. A cohort of Brazilian women (N = 1038) with unilateral non-metastatic breast cancer was evaluated. The association between VEGFA polymorphisms and histopathological features or pathological complete response (pCR) to neoadjuvant chemotherapy was evaluated by the Chi-square test, with calculation of the respective odds ratio (OR) and 95% confidence intervals (95% CI). The impact of individual categories on disease-free survival was evaluated using Kaplan-Meier curves and multivariate Cox proportional hazards regression models for calculation of adjusted hazard ratios (HRadjusted). Variant genotypes of rs699947 (CA + AA) were significantly associated with high-grade (G2 + G3) tumors (OR = 1.82; 95% CI = 1.15 - 2.89), and with shorter disease-free survival among patients treated with neoadjuvant chemotherapy followed by mastectomy (HRadjusted = 1.82; 95% CI = 1.16 - 2.86). Variant genotypes of rs833061 (TC + CC) were significantly associated with high-grade (G2 + G3) tumors (OR = 1.79; 95% CI = 1.12 - 2.84) and with positive lymph node status (OR = 1.34; 95% CI = 1.01 - 1.77), but showed no independent effect on disease-free survival. Variant haplotypes (*2 to *5) appear to favor pCR (OR = 7.1; 95% CI = 1.7 - 30.1). VEGFA genotyping may add to prognostic evaluation of breast cancer, with rs699947 being the most likely to contribute.

A niche that triggers aggressiveness within BRCA1-IRIS overexpressing triple negative tumors is supported by reciprocal interactions with the microenvironment

Production of metastasis capable precursors begins within the primary tumor. Here, we define the bidirectional interactions with stromal cells involved in promoting these precursors within BRCA1-IRIS (hereafter IRIS) overexpressing (IRISOE) TNBC tumors. We define an aggressiveness niche, functionally defined as the necrotic/hypoxic core of the tumor, in which metabolically stressed, hypoxic, and inflamed IRISOE TNBC cells secrete higher levels of cytokines, chemokines and growth factors. One cytokine; IL-1β attracts mesenchymal stem cells (MSCs) to the niche and activates them to secrete CXCL1 that entrains IRISOE cells to secrete higher levels of CCL2 and VEGF. CCL2 attracts macrophages (TAMs) to the niche and activates them to secrete S100A8, and VEGF attracts endothelial cells (ECs) and activates them to secrete IL-8. In concert, CXCL1, S100A8 and IL-8 entrain aggressiveness in IRISOE TNBC cells within the niche. Indeed, compared to IRISOE cells alone, tumors developed by co-injecting IRISOE cells admixed with MSCs (10:1) in athymic mice were bigger and more aggressive. They contained more TAMs and ECs, expressed higher-levels of basal, epithelial to mesenchymal transition, and stemness biomarkers, quickly progressed to lymph-node or visceral metastases, and were highly sensitive to the IL-1β inhibitor “Anakinra”. Our findings supported by human data show that breast cancer patients with high-levels of IL-1β, CXCL1, CCL2, S100A8, VEGF, and IL-8 would show worse clinical outcomes. Our findings argue that this cytokine set is a diagnostic biomarker for patients who may benefit from an IRIS inhibitor-based therapy, and is a blue print for translation of approaches to combining that therapy with inhibitors of these bidirectional interactions to overcome TNBC metastasis.

Hypertension Caused by Lenvatinib and Everolimus in the Treatment of Metastatic Renal Cell Carcinoma

Multikinase inhibitors (MKI) and mammalian target of rapamycin (mTOR) inhibitors prolong progression-free (PFS) and overall survival (OS) in the treatment of metastatic renal cell carcinoma (mRCC) by reducing angiogenesis and tumor growth. In this regard, the MKI lenvatinib and the mTOR inhibitor everolimus proved effective when applied alone, but more effective when they were administered combined. Recently, both drugs were included in clinical trials, resulting in international clinical guidelines for the treatment of mRCC. In May 2016, lenvatinib was approved by the American Food and Drug Administration (FDA) for the use in combination with everolimus, as treatment of advanced renal cell carcinoma following one prior antiangiogenic therapy. A major problem of treating mRCC with lenvatinib and everolimus is the serious adverse event (AE) of arterial hypertension. During the treatment with everolimus and lenvatinib combined, 42% of the patients developed hypertension, while 10% of the patients treated with everolimus alone and 48% of the of the lenvatinib only treated patients developed hypertension. Lenvatinib carries warnings and precautions for hypertension, cardiac failure, and other adverse events. Therefore, careful monitoring of the patients is necessary.

Bevacizumab-Based Chemotherapy Combined with Regional Deep Capacitive Hyperthermia in Metastatic Cancer Patients: A Pilot Study

As an angiogenesis inhibitor, bevacizumab has been investigated in combination with different chemotherapeutic agents, achieving an established role for metastatic cancer treatment. However, potential synergic anti-angiogenic effects of hyperthermia have not tested to date in literature. The aim of our study was to analyze efficacy, safety, and survival of anti-angiogenic-based chemotherapy associated to regional deep capacitive hyperthermia (HT) in metastatic cancer patients. Twenty-three patients with metastatic colorectal (n = 16), ovarian (n = 5), and breast (n = 2) cancer were treated with HT in addition to a standard bevacizumab-based chemotherapy regimen. Treatment response assessment was performed, according to the modified Response Evaluation Criteria for Solid Tumors (mRECIST), at 80 days (timepoint-1) and at 160 days (timepoint-2) after therapy. Disease Response Rate (DRR), considered as the proportion of patients who had the best response rating (complete response (CR), partial response (PR), or stable disease (SD)), was assessed at timepoint-1 and timepoint-2. Chi-squared for linear trend test was performed to evaluated the association between response groups (R/NR) and the number of previous treatment (none, 1, 2, 3), number of chemotherapy cycles (<6, 6, 12, >12), number of hyperthermia sessions (<12, 12, 24, >24), and lines of chemotherapy (I, II). Survival curves were estimated by Kaplan-Meier method. DRR was 85.7% and 72.2% at timepoint-1 and timepoint-2, respectively. HT was well tolerated without additional adverse effects on chemotherapy-related toxicity. Chi-squared for linear trend test demonstrated that the percentage of responders grew in relation to the number of chemotherapy cycles (p = 0.015) and to number of HT sessions (p < 0.001) performed. Both overall survival (OS) and time to progression (TTP) were influenced by the number of chemotherapy cycles (p < 0.001) and HT sessions (p < 0.001) performed. Our preliminary data, that need to be confirmed in larger studies, suggest that the combined treatment of bevacizumab-based chemotherapy with HT has a favorable tumor response, is feasible and well tolerated, and offers a potentially promising option for metastatic cancer patients.

Sorafenib for the treatment of breast cancer

INTRODUCTION

Breast cancer treatment includes many options depending on the tumor clinicopathological profile, which groups breast cancer into various subtypes. Bevacizumab is currently the only drug capable of targeting angiogenesis in breast cancer. Sorafenib has also been studied in combination with other agents. Areas covered: Pharmacological aspects of sorafenib, including results from preclinical studies on breast cancer cells; findings about clinical efficacy and safety in both single-arm and randomized clinical trials; ongoing trials. Expert opinion: Since sorafenib as a single agent has shown limited efficacy in breast cancer, its combination with other drugs is under investigation. Dose reduction is the main challenge when sorafenib is combined with chemotherapy or endocrine therapy. Although randomized phase-II trials on sorafenib plus chemotherapy versus chemotherapy alone have shown potential benefits in progression-free survival, preliminary results from a phase-III study in combination with capecitabine are negative. The definitive results of this trial and results from other ongoing phase-II trials will determine further developments of sorafenib in breast cancer. Although these additional data could help determine the most appropriate dose, drug combination and patient settings, a confirmation of the preliminary negative results reported in the phase-III trial are likely to discourage further use of sorafenib in breast cancer, given its non-negligible toxicity, lack of predicting markers, and the number of more promising drugs for breast cancer.

The Adverse Effect of Hypertension in the Treatment of Thyroid Cancer with Multi-Kinase Inhibitors

The treatment of thyroid cancer has promising prospects, mostly through the use of surgical or radioactive iodine therapy. However, some thyroid cancers, such as progressive radioactive iodine-refractory differentiated thyroid carcinoma, are not remediable with conventional types of treatment. In these cases, a treatment regimen with multi-kinase inhibitors is advisable. Unfortunately, clinical trials have shown a large number of patients, treated with multi-kinase inhibitors, being adversely affected by hypertension. This means that treatment of thyroid cancer with multi-kinase inhibitors prolongs progression-free and overall survival of patients, but a large number of patients experience hypertension as an adverse effect of the treatment. Whether the prolonged lifetime is sufficient to develop sequelae from hypertension is unclear, but late-stage cancer patients often have additional diseases, which can be complicated by the presence of hypertension. Since the exact mechanisms of the rise of hypertension in these patients are still unknown, the only available strategy is treating the symptoms. More studies determining the pathogenesis of hypertension as a side effect to cancer treatment as well as outcomes of dose management of cancer drugs are necessary to improve future therapy options for hypertension as an adverse effect to cancer therapy with multi-kinase inhibitors.

Lunasin Attenuates Obesity-Associated Metastasis of 4T1 Breast Cancer Cell through Anti-Inflammatory Property

Obesity prevalence is increasing worldwide and is accompanied by low-grade inflammation with macrophage infiltration, which is linked with a poorer breast cancer prognosis. Lunasin is a natural seed peptide with chemopreventive properties and multiple bioactivities. This is the first study to explore the chemopreventive effects of lunasin in the obesity-related breast cancer condition using 4T1 breast cancer cells, 3T3-L1 adipocytes, and conditioned media. An obesity-related environment, such as leptin-treatment or adipocyte-conditioned medium (Ad-CM), promoted 4T1 cell proliferation and metastasis. Lunasin treatment inhibited metastasis of breast cancer cells, partially through modestly inhibiting production of the angiogenesis-mediator vascular endothelial growth factor (VEGF) and significantly by inhibiting secretion in the Ad-CM condition. Subsequently, two adipocytes inflammation models, 3T3-L1 adipocytes were stimulated by tumor necrosis factor (TNF)-α, and RAW 264.7 cell-conditioned medium (RAW-CM) was used to mimic the obese microenvironment. Lunasin significantly inhibited interleukin (IL)-6 and macrophage chemoattractant protein (MCP)-1 secretion by TNF-α stimulation, and MCP-1 secretion in the RAW-CM model. This study highlights that lunasin suppressed 3T3-L1 adipocyte inflammation and inhibited 4T1 breast cancer cell migration. Interestingly, lunasin exerted more effective anti-metastasis activity in the obesity-related condition models, indicating that it possesses anti-inflammatory properties and blocks adipocyte-cancer cell cross-talk.

Accession of Tumor Heterogeneity by Multiplex Transcriptome Profiling of Single Circulating Tumor Cells

BACKGROUND

Transcriptome analysis of circulating tumor cells (CTCs) holds great promise to unravel the biology of cancer cell dissemination and identify expressed genes and signaling pathways relevant to therapeutic interventions.

METHODS

CTCs were enriched based on their EpCAM expression (CellSearch®) or by size and deformability (ParsortixTM), identified by EpCAM and/or pan-keratin–specific antibodies, and isolated for single cell multiplex RNA profiling.

RESULTS

Distinct breast and prostate CTC expression signatures could be discriminated from RNA profiles of leukocytes. Some CTCs positive for epithelial transcripts (EpCAM and KRT19) also coexpressed leukocyte/mesenchymal associated markers (PTPRC and VIM). Additional subsets of CTCs within individual patients were characterized by divergent expression of genes involved in epithelial–mesenchymal transition (e.g., CDH2, MMPs, VIM, or ZEB1 and 2), DNA repair (RAD51), resistance to cancer therapy (e.g., AR, AR-V7, ERBB2, EGFR), cancer stemness (e.g., CD24 and CD44), activated signaling pathways involved in tumor progression (e.g., PIK3CA and MTOR) or cross talks between tumors and immune cells (e.g., CCL4, CXCL2, CXCL9, IL15, IL1B, or IL8).

CONCLUSIONS

Multimarker RNA profiling of single CTCs reveals distinct CTC subsets and provides important insights into gene regulatory networks relevant for cancer progression and therapy.

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.

Angiogenic cytokines and their influence on circulating tumour cells in sera of patients with the primary diagnosis of breast cancer before treatment

Background

Circulating tumour cells (CTCs) have been found to be a prognostic marker for reduced disease free survival, breast cancer–specific survival, and overall survival before the start of systemic treatment.

Methods

A total of 200 patients’ sera were included in this study, 100 patients being CTC positive and 100 patients being CTC negative. Matching criteria were histo-pathological grading, lymph node metastasis, hormone receptor status, TNM classification and survived breast cancer patients vs. deceased tumor associated patients. A multi cytokine/chemokine array was used to screen the sera for the angiogenic markers.

Results

Statistical significant correlation was exposed for sFlt1 values in regard to the CTC-Status. CTC negative patients displayed increased sFlt1 expression opposed to CTC positive breast cancer patients. Furthermore, significant enhanced PIGF values were also disclosed in CTC negative patients compared to patients being CTC positive. Analyzing the living patient collective we found significant differences in sFlt1 and PlGF values in regard to CTC negative and CTC positive patients.

Conclusion

Both vascular markers showed enhanced expression in the CTC negative patient collective. To continue, the collective graded G2 showed significantly enhanced sFlt1 expressions amongst patients with no CTCs. Moreover, the patient collective with no lymph node metastasis and CTC negativity indicated statistically significant increased sFlt1 values. A functional interaction of sFlt1 and PlGF was found, suggesting that their overexpression in tumour cells inhibits CTCs entering the peripheral blood. Furthermore, in regard to CTC negativity, sFlt1 and PlGF values may potentially serve as predictive markers.

Trial registration

The TRN of this study is NCT02181101 and the date of registration was the 4^th of June 2014. The study was retrospectively registered.

Identifications of novel mechanisms in breast cancer cells involving duct-like multicellular spheroid formation after exposure to the Random Positioning Machine

Many cell types form three-dimensional aggregates (MCS; multicellular spheroids), when they are cultured under microgravity. MCS often resemble the organ, from which the cells have been derived. In this study we investigated human MCF-7 breast cancer cells after a 2 h-, 4 h-, 16 h-, 24 h- and 5d-exposure to a Random Positioning Machine (RPM) simulating microgravity. At 24 h few small compact MCS were detectable, whereas after 5d many MCS were floating in the supernatant above the cells, remaining adherently (AD). The MCS resembled the ducts formed in vivo by human epithelial breast cells. In order to clarify the underlying mechanisms, we harvested MCS and AD cells separately from each RPM-culture and measured the expression of 29 selected genes with a known involvement in MCS formation. qPCR analyses indicated that cytoskeletal genes were unaltered in short-term samples. IL8, VEGFA, and FLT1 were upregulated in 2 h/4 h AD-cultures. The ACTB, TUBB, EZR, RDX, FN1, VEGFA, FLK1 Casp9, Casp3, PRKCA mRNAs were downregulated in 5d-MCS-samples. ESR1 was upregulated in AD, and PGR1 in both phenotypes after 5d. A pathway analysis revealed that the corresponding gene products are involved in organization and regulation of the cell shape, in cell tip formation and membrane to membrane docking.

The DEK oncogene activates VEGF expression and promotes tumor angiogenesis and growth in HIF-1α-dependent and -independent manners

The DEK oncogene is overexpressed in various cancers and overexpression of DEK correlates with poor clinical outcome. Vascular endothelial growth factor (VEGF) is the most important regulator of tumor angiogenesis, a process essential for tumor growth and metastasis. However, whether DEK enhances tumor angiogenesis remains unclear. Here, we show that DEK is a key regulator of VEGF expression and tumor angiogenesis. Using chromatin immunoprecipitation assay, we found that DEK promoted VEGF transcription in breast cancer cells (MCF7, ZR75-1 and MDA-MB-231) by directly binding to putative DEK-responsive element (DRE) of the VEGF promoter and indirectly binding to hypoxia response element (HRE) upstream of the DRE through its interaction with the transcription factor hypoxia-inducible factor 1α (HIF-1α), a master regulator of tumor angiogenesis and growth. DEK is responsible for recruitment of HIF-1α and the histone acetyltransferase p300 to the VEGF promoter. DEK-enhanced VEGF increases vascular endothelial cell proliferation, migration and tube formation as well as angiogenesis in the chick chorioallantoic membrane. DEK promotes tumor angiogenesis and growth in nude mice in HIF-1α-dependent and -independent manners. Immunohistochemical staining showed that DEK expression positively correlates with the expression of VEGF and microvessel number in 58 breast cancer patients. Our data establish DEK as a sequence-specific binding transcription factor, a novel coactivator for HIF-1α in regulation of VEGF transcription and a novel promoter of angiogenesis.

The Importance of Caveolin-1 as Key-Regulator of Three-Dimensional Growth in Thyroid Cancer Cells Cultured under Real and Simulated Microgravity Conditions

We recently demonstrated that the CAV1 gene was down-regulated, when poorly differentiated thyroid FTC-133 cancer cells formed spheroids under simulated microgravity conditions. Here, we present evidence that the caveolin-1 protein is involved in the inhibition of spheroid formation, when confluent monolayers are exposed to microgravity. The evidence is based on proteins detected in cells and their supernatants of the recent spaceflight experiment: "NanoRacks-CellBox-Thyroid Cancer". The culture supernatant had been collected in a special container adjacent to the flight hardware incubation chamber and stored at low temperature until it was analyzed by Multi-Analyte Profiling (MAP) technology, while the cells remaining in the incubation chamber were fixed by RNAlater and examined by mass spectrometry. The soluble proteins identified by MAP were investigated in regard to their mutual interactions and their influence on proteins, which were associated with the cells secreting the soluble proteins and had been identified in a preceding study. A Pathway Studio v.11 analysis of the soluble and cell-associated proteins together with protein kinase C alpha (PRKCA) suggests that caveolin-1 is involved, when plasminogen enriched in the extracellular space is not activated and the vascular cellular adhesion molecule (VCAM-1) mediated cell-cell adhesion is simultaneously strengthened and activated PRKCA is recruited in caveolae, while the thyroid cancer cells do not form spheroids.

Activin Receptor-like Kinase 1 Ligand Trap Reduces Microvascular Density and Improves Chemotherapy Efficiency to Various Solid Tumors

PURPOSE

Antiangiogenic therapy, mostly targeting VEGF, has been applied in cancer patients for the last decade. However, resistance to anti-VEGF therapy and/or no significant benefit as monotherapeutic agent is often observed. Therefore, new antiangiogenic strategies are needed. In the current study, we investigated the therapeutic effect of interfering with the bone morphogenetic protein (BMP)9/activin receptor-like kinase (ALK)1 signaling pathway by using an ALK1-Fc ligand trap.

EXPERIMENTAL DESIGN

We analyzed the potential antiangiogenic and antitumor effects of ALK1-Fc protein as monotherapy and in combination with chemotherapy in vivo in mouse models of melanoma, head and neck cancer, and invasive lobular breast carcinomas. ALK1-Fc sequesters BMP9 and 10 and prevents binding of these ligands to endothelial ALK1, which regulates angiogenesis.

RESULTS

Treatment of mice with ALK1-Fc strongly decreased the tumors' microvascular density in the three different mouse cancer models. However, this effect was not accompanied by a reduction in tumor volume. An immunohistochemical analysis of the tumor samples revealed that ALK1-Fc treatment increased the pericyte coverage of the remaining tumor vessels and decreased the hypoxia within the tumor. Next, we observed that combining ALK1-Fc with cisplatin inhibited tumor growth in the breast and head and neck cancer models more efficiently than chemotherapy alone.

CONCLUSIONS

The addition of ALK1-Fc to the cisplatin treatment was able to enhance the cytotoxic effect of the chemotherapy. Our results provide strong rationale to explore combined targeting of ALK1 with chemotherapy in a clinical setting, especially in the ongoing phase II clinical trials with ALK1-Fc.

Common Effects on Cancer Cells Exerted by a Random Positioning Machine and a 2D Clinostat

In this study we focused on gravity-sensitive proteins of two human thyroid cancer cell lines (ML-1; RO82-W-1), which were exposed to a 2D clinostat (CLINO), a random positioning machine (RPM) and to normal 1g-conditions. After a three (3d)- or seven-day-culture (7d) on the two devices, we found both cell types growing three-dimensionally within multicellular spheroids (MCS) and also cells remaining adherent (AD) to the culture flask, while 1g-control cultures only formed adherent monolayers, unless the bottom of the culture dish was covered by agarose. In this case, the cytokines IL-6 and IL-8 facilitated the formation of MCS in both cell lines using the liquid-overlay technique at 1g. ML-1 cells grown on the RPM or the CLINO released amounts of IL-6 and MCP-1 into the supernatant, which were significantly elevated as compared to 1g-controls. Release of IL-4, IL-7, IL-8, IL-17, eotaxin-1 and VEGF increased time-dependently, but was not significantly influenced by the gravity conditions. After 3d on the RPM or the CLINO, an accumulation of F-actin around the cellular membrane was detectable in AD cells of both cell lines. IL-6 and IL-8 stimulation of ML-1 cells for 3d and 7d influenced the protein contents of ß₁-integrin, talin-1, Ki-67, and beta-actin dose-dependently in adherent cells. The ß₁-integrin content was significantly decreased in AD and MCS samples compared with 1g, while talin-1 was higher expressed in MCS than AD populations. The proliferation marker Ki-67 was elevated in AD samples compared with 1g and MCS samples. The ß-actin content of R082-W-1 cells remained unchanged. ML-1 cells exhibited no change in ß-actin in RPM cultures, but a reduction in CLINO samples. Thus, we concluded that simulated microgravity influences the release of cytokines in follicular thyroid cancer cells, and the production of ß₁-integrin and talin-1 and predicts an identical effect under real microgravity conditions.

Targeting Angiogenesis in Cancer Therapy: Moving Beyond Vascular Endothelial Growth Factor

Angiogenesis, or the formation of new capillary blood vessels, occurs primarily during human development and reproduction; however, aberrant regulation of angiogenesis is also a fundamental process found in several pathologic conditions, including cancer. As a process required for invasion and metastasis, tumor angiogenesis constitutes an important point of control of cancer progression. Although not yet completely understood, the complex process of tumor angiogenesis involves highly regulated orchestration of multiple signaling pathways. The proangiogenic signaling molecule vascular endothelial growth factor (VEGF) and its cognate receptor (VEGF receptor 2 [VEGFR-2]) play a central role in angiogenesis and often are highly expressed in human cancers, and initial clinical efforts to develop antiangiogenic treatments focused largely on inhibiting VEGF/VEGFR signaling. Such approaches, however, often lead to transient responses and further disease progression because angiogenesis is regulated by multiple pathways that are able to compensate for each other when single pathways are inhibited. The platelet-derived growth factor (PDGF) and PDGF receptor (PDGFR) and fibroblast growth factor (FGF) and FGF receptor (FGFR) pathways, for example, provide potential escape mechanisms from anti-VEGF/VEGFR therapy that could facilitate resumption of tumor growth. Accordingly, more recent treatments have focused on inhibiting multiple signaling pathways simultaneously. This comprehensive review discusses the limitations of inhibiting VEGF signaling alone as an antiangiogenic strategy, the importance of other angiogenic pathways including PDGF/PDGFR and FGF/FGFR, and the novel current and emerging agents that target multiple angiogenic pathways for the treatment of advanced solid tumors.

IMPLICATIONS FOR PRACTICE

Significant advances in cancer treatment have been achieved with the development of antiangiogenic agents, the majority of which have focused on inhibition of the vascular endothelial growth factor (VEGF) pathway. VEGF targeting alone, however, has not proven to be as efficacious as originally hoped, and it is increasingly clear that there are many interconnected and compensatory pathways that can overcome VEGF-targeted inhibition of angiogenesis. Maximizing the potential of antiangiogenic therapy is likely to require a broader therapeutic approach using a new generation of multitargeted antiangiogenic agents.