Pathophysiology of tumor neovascularization

Combining conventional ultrasound and ultrasound elastography to predict HER2 status in patients with breast cancer

Introduction: Identifying the HER2 status of breast cancer patients is important for treatment options. Previous studies have shown that ultrasound features are closely related to the subtype of breast cancer. Methods: In this study, we used features of conventional ultrasound and ultrasound elastography to predict HER2 status. Results and Discussion: The performance of model (AUROC) with features of conventional ultrasound and ultrasound elastography is higher than that of the model with features of conventional ultrasound (0.82 vs. 0.53). The SHAP method was used to explore the interpretability of the models. Compared with HER2- tumors, HER2+ tumors usually have greater elastic modulus parameters and microcalcifications. Therefore, we concluded that the features of conventional ultrasound combined with ultrasound elastography could improve the accuracy for predicting HER2 status.

Catulin reporter marks a heterogeneous population of invasive breast cancer cells with some demonstrating plasticity and participating in vascular mimicry

Breast cancer is the most commonly diagnosed cancer in women worldwide. The activation of partial or more complete epithelial–mesenchymal transition in cancer cells enhances acquisition of invasive behaviors and expands their generation of cancer stem cells. Increased by EMT plasticity of tumor cells could promote vascular mimicry, a newly defined pattern of tumor microvascularization by which aggressive tumor cells can form vessel-like structures themselves. VM is strongly associated with a poor prognosis, but biological features of tumor cells that form VM remains unknown. Here we show that catulin is expressed in human BC samples and its expression correlates with the tumor progression. Ablation of catulin in hBC cell lines decreases their invasive potential in the 3D assays. Using a novel catulin promoter based reporter we tracked and characterized the small population of invasive BC cells in xenograft model. RNAseq analysis revealed enrichment in genes important for cellular movement, invasion and interestingly for tumor-vasculature interactions. Analysis of tumors unveiled that catulin reporter marks not only invasive cancer cells but also rare population of plastic, MCAM positive cancer cells that participate in vascular mimicry. Ablation of catulin in the xenograft model revealed deregulation of genes involved in cellular movement, and adhesive properties with striking decrease in CD44 which may impact stemness potential, and plasticity of breast cancer cells. These findings show directly that some plastic tumor cells can change the fate into endothelial-like, expressing MCAM and emphasize the importance of catulin in this process and breast cancer progression.

Transcriptomic and Functional Evidence for Differential Effects of MCF-7 Breast Cancer Cell-Secretome on Vascular and Lymphatic Endothelial Cell Growth

Vascular and lymphatic vessels drive breast cancer (BC) growth and metastasis. We assessed the cell growth (proliferation, migration, and capillary formation), gene-, and protein-expression profiles of Vascular Endothelial Cells (VECs) and Lymphatic Endothelial Cells (LECs) exposed to a conditioned medium (CM) from estrogen receptor-positive BC cells (MCF-7) in the presence or absence of Estradiol. We demonstrated that MCF-7-CM stimulated growth and capillary formation in VECs but inhibited LEC growth. Consistently, MCF-7-CM induced ERK1/2 and Akt phosphorylation in VECs and inhibited them in LECs. Gene expression analysis revealed that the LECs were overall (≈10-fold) more sensitive to MCF-7-CM exposure than VECs. Growth/angiogenesis and cell cycle pathways were upregulated in VECs but downregulated in LECs. An angiogenesis proteome array confirmed the upregulation of 23 pro-angiogenesis proteins in VECs. In LECs, the expression of genes related to ATP synthesis and the ATP content were reduced by MCF-7-CM, whereas MTHFD2 gene, involved in folate metabolism and immune evasion, was upregulated. The contrasting effect of MCF-7-CM on the growth of VECs and LECs was reversed by inhibiting the TGF-β signaling pathway. The effect of MCF-7-CM on VEC growth was also reversed by inhibiting the VEGF signaling pathway. In conclusion, BC secretome may facilitate cancer cell survival and tumor growth by simultaneously promoting vascular angiogenesis and inhibiting lymphatic growth. The differential effects of BC secretome on LECs and VECs may be of pathophysiological relevance in BC.

Biological aspects in controlling angiogenesis: current progress

All living beings continue their life by receiving energy and by excreting waste products. In animals, the arteries are the pathways of these transfers to the cells. Angiogenesis, the formation of the arteries by the development of pre-existed parental blood vessels, is a phenomenon that occurs naturally during puberty due to certain physiological processes such as menstruation, wound healing, or the adaptation of athletes' bodies during exercise. Nonetheless, the same life-giving process also occurs frequently in some patients and, conversely, occurs slowly in some physiological problems, such as cancer and diabetes, so inhibiting angiogenesis has been considered to be one of the important strategies to fight these diseases. Accordingly, in tissue engineering and regenerative medicine, the highly controlled process of angiogenesis is very important in tissue repairing. Excessive angiogenesis can promote tumor progression and lack of enough angiogensis can hinder tissue repair. Thereby, both excessive and deficient angiogenesis can be problematic, this review article introduces and describes the types of factors involved in controlling angiogenesis. Considering all of the existing strategies, we will try to lay out the latest knowledge that deals with stimulating/inhibiting the angiogenesis. At the end of the article, owing to the early-reviewed mechanical aspects that overshadow angiogenesis, the strategies of angiogenesis in tissue engineering will be discussed.

Mass spectrometry imaging of L-[ring-13C6]-labeled phenylalanine and tyrosine kinetics in non-small cell lung carcinoma

BACKGROUND

Metabolic reprogramming is a common phenomenon in tumorigenesis and tumor progression. Amino acids are important mediators in cancer metabolism, and their kinetics in tumor tissue are far from being understood completely. Mass spectrometry imaging is capable to spatiotemporally trace important endogenous metabolites in biological tissue specimens. In this research, we studied L-[ring-¹³C₆]-labeled phenylalanine and tyrosine kinetics in a human non-small cell lung carcinoma (NSCLC) xenografted mouse model using matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry imaging (MALDI-FTICR-MSI).

METHODS

We investigated the L-[ring-¹³C₆]-Phenylalanine (¹³C₆-Phe) and L-[ring-¹³C₆]-Tyrosine (¹³C₆-Tyr) kinetics at 10 min (n = 4), 30 min (n = 3), and 60 min (n = 4) after tracer injection and sham-treated group (n = 3) at 10 min in mouse-xenograft lung tumor tissues by MALDI-FTICR-MSI.

RESULTS

The dynamic changes in the spatial distributions of 19 out of 20 standard amino acids are observed in the tumor tissue. The highest abundance of ¹³C₆-Phe was detected in tumor tissue at 10 min after tracer injection and decreased progressively over time. The overall enrichment of ¹³C₆-Tyr showed a delayed temporal trend compared to ¹³C₆-Phe in tumor caused by the Phe-to-Tyr conversion process. Specifically, ¹³C₆-Phe and ¹³C₆-Tyr showed higher abundances in viable tumor regions compared to non-viable regions.

CONCLUSIONS

We demonstrated the spatiotemporal intra-tumoral distribution of the essential aromatic amino acid ¹³C₆-Phe and its de-novo synthesized metabolite ¹³C₆-Tyr by MALDI-FTICR-MSI. Our results explore for the first time local phenylalanine metabolism in the context of cancer tissue morphology. This opens a new way to understand amino acid metabolism within the tumor and its microenvironment.

Evaluation of a tumor electric field treatment system in a rat model of glioma

Objective

Glioma is a devastating disease lacking effective treatment. Tumor electric field therapy is emerging as a novel non‐invasive therapy. The current study evaluates the efficacy and safety of a self‐designed tumor electric field therapy system (TEFTS ASCLU‐300) in a rat orthotopic transplantation model of glioma.

Methods

A model of intracranial orthotopic transplantation was established in rats using glioma C6 cells. For electric field therapy, glioma‐bearing rats were exposed to alternating electric fields generated by a self‐developed TEFTS starting on either 1st (Group 2) or 3rd (Group 3) day after transplantation, while other conditions were maintained the same as non‐treated rats (Group 1). Glioma size, body weight, and overall survival (OS) were compared between groups. Immunohistochemical staining was applied to access tumor cell death and microvessel density within the tumor. In addition, the systemic effects of TEFTS on blood cells, vital organs, and hepatorenal functions were evaluated.

Results

TEFTS treatment significantly elongated the OS of tumor‐bearing rats compared with non‐treated rats (non‐treated vs treated: 24.77 ± 7.08 days vs 40.31 ± 19.11 days, P = .0031). Continuous TEFTS treatment starting on 1st or 3rd day significantly reduced glioma size at 2 and 3 weeks after tumor cell inoculation (Week 2: Group 1:289.95 ± 101.69 mm³; Group 2:70.45 ± 17.79 mm³; Group 3:73.88 ± 33.21 mm³, P < .0001. Week 3: Group 1:544.096 ± 78.53 mm³; Group 2:187.58 ± 78.44 mm³; Group 3:167.14 ± 109.96 mm³, P = .0005). Continuous treatment for more than 4 weeks inhibited tumor growth. The TEFTS treatment promoted tumor cell death, as demonstrated by increased number of Caspase 3⁺ cells within the tumor (non‐treated vs treated: 38.06 ± 10.04 vs 68.57 ± 8.09 cells/field, P = .0007), but had minimal effect on microvessel density, as shown by CD31 expression (non‐treated vs treated: 1.63 ± 0.09 vs 1.57 ± 0.13% of positively stained areas, P > .05). No remarkable differences were observed in hepatorenal function, blood cell counts, or other vital organs between non‐treated and treated groups.

Conclusion

The TEFTS developed by our research team was proved to be effective and safe to inhibit tumor growth and improve general outcomes in a rat model of brain glioma.

Endothelial Cells in the Tumor Microenvironment

Angiogenesis is a critical process required for tumor progression. Newly formed blood vessels provide nutrition and oxygen to the tumor contributing to its growth and development. However, endothelium also plays other functions that promote tumor metastasis. It is involved in intravasation, which allows invasive cancer cells to translocate into the blood vessel lumen. This phenomenon is an important stage for cancer metastasis. Besides direct association with cancer development, endothelial cells are one of the main sources of cancer-associated fibroblasts (CAFs). The heterogeneous group of CAFs is the main inductor of migration and invasion abilities of cancer cells. Therefore, the endothelium is also indirectly responsible for metastasis. Considering the above, the endothelium is one of the important targets of anticancer therapy. In the chapter, we will present mechanisms regulating endothelial function, dependent on cancer and cancer niche cells. We will focus on possibilities of suppressing pro-metastatic endothelial functions, applied in anti-cancer therapies.

Photoacoustic Imaging in Tissue Engineering and Regenerative Medicine

Several imaging modalities are available for investigation of the morphological, functional, and molecular features of engineered tissues in small animal models. While research in tissue engineering and regenerative medicine (TERM) would benefit from a comprehensive longitudinal analysis of new strategies, researchers have not always applied the most advanced methods. Photoacoustic imaging (PAI) is a rapidly emerging modality that has received significant attention due to its ability to exploit the strong endogenous contrast of optical methods with the high spatial resolution of ultrasound methods. Exogenous contrast agents can also be used in PAI for targeted imaging. Applications of PAI relevant to TERM include stem cell tracking, longitudinal monitoring of scaffolds in vivo, and evaluation of vascularization. In addition, the emerging capabilities of PAI applied to the detection and monitoring of cancer and other inflammatory diseases could be exploited by tissue engineers. This article provides an overview of the operating principles of PAI and its broad potential for application in TERM. Impact statement Photoacoustic imaging, a new hybrid imaging technique, has demonstrated high potential in the clinical diagnostic applications. The optical and acoustic aspect of the photoacoustic imaging system works in harmony to provide better resolution at greater tissue depth. Label-free imaging of vasculature with this imaging can be used to track and monitor disease, as well as the therapeutic progression of treatment. Photoacoustic imaging has been utilized in tissue engineering to some extent; however, the full benefit of this technique is yet to be explored. The increasing availability of commercial photoacoustic systems will make application as an imaging tool for tissue engineering application more feasible. This review first provides a brief description of photoacoustic imaging and summarizes its current and potential application in tissue engineering.

Regulation Networks Driving Vasculogenic Mimicry in Solid Tumors

Vasculogenic mimicry (VM) is a mechanism whereby cancer cells form microvascular structures similar to three-dimensional channels to provide nutrients and oxygen to tumors. Unlike angiogenesis, VM is characterized by the development of new patterned three-dimensional vascular-like structures independent of endothelial cells. This phenomenon has been observed in many types of highly aggressive solid tumors. The presence of VM has also been associated with increased resistance to chemotherapy, low survival, and poor prognosis. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are non-coding RNAs that regulate gene expression at the post-transcriptional level through different pathways. In recent years, these tiny RNAs have been shown to be expressed aberrantly in different human malignancies, thus contributing to the hallmarks of cancer. In this context, miRNAs and lncRNAs can be excellent biomarkers for diagnosis, prognosis, and the prediction of response to therapy. In this review, we discuss the role that the tumor microenvironment and the epithelial-mesenchymal transition have in VM. We include an overview of the mechanisms of VM with examples of diverse types of tumors. Finally, we describe the regulation networks of lncRNAs-miRNAs and their clinical impact with the VM. Knowing the key genes that regulate and promote the development of VM in tumors with invasive, aggressive, and therapy-resistant phenotypes will facilitate the discovery of novel biomarker therapeutics against cancer as well as tools in the diagnosis and prognosis of patients.

Interplay between STAT3, Cell Adhesion Molecules and Angiogenesis-Related Parameters in Gastric Carcinoma. Does STAT3 Really Have a Prognostic Value?

Background and objectives: Gastric cancer (GC) is one of the deadliest malignancies, with the underlying pathophysiological mechanisms still not completely understood. In this study, we aimed to investigate the signal transducer and activator of transcription 3 (STAT3) moleculeconnection with the pathological features of GCs, and the expression of cell adhesive molecules (E-cadherin and β-catenin) and angiogenesis-related factors (vascular endothelial growth factor (VEGF), HIF1α, and CD31)). Materials and Methods: This study comprised 136 cases of GCs with data related to the patients’ demographic characteristics (age, gender) and pathological features (tumor location, gross type, Laurens’ type of GC, histological differentiation, invasion depth, lymphovascular invasion and the presence of metastases) which were correlated with STAT3 expression. Additionally, STAT3 expression and the expression of adhesive molecules and angiogenesis-related factors were studied by immunohistochemical methods. Results: The expression of STAT3 was found to be significantly associated with the occurrence of poorly differentiated GCs in the lower portion of the stomach and with the presence of distant metastases. Interestingly, none of the investigated parameters related to cell adhesion or to angiogenesis were found to be related to the expression of STAT3. Conclusions: The lack of significant differences between the studied STAT3 expression and some of the molecules associated with different cancer features might be due to the characteristics of the studied population sample associated with the origin, heterogeneity, and cancer pathophysiological background. Nonetheless, the results of our study suggest that STAT3 could be a useful marker for the presence of distant GC metastases, which further indicates that STAT3 action might involve some other signaling molecules/pathways that warrant further elucidation.

Changes of tumor infiltrating lymphocyte subtypes before and after neoadjuvant endocrine therapy in estrogen receptor-positive breast cancer patients – an immunohistochemical study of cd8+ and foxp3+ using double immunostaining with correlation to the pathobiological response of the patients

Tumor-stromal interactions involve continuous crosstalk and interactions among different cell types and play pivotal roles in tumorigenesis, tumor development, disease progression, subsequent metastasis, and also tumor response to therapeutic agents. Tumor infiltrating lymphocytes (TILs) are important components of these tumor-stromal interactions. Specific TIL subtypes are known to be involved in the clinical course of individual patients. However, the status of TILs following endocrine therapy has not been studied in breast cancer patients. We evaluated the alterations of TIL subtypes in a cohort of East Asian patients with estrogen receptor-positive breast cancer during the course of neoadjuvant steroidal aromatase inhibitor (AI) therapy, using double immunohistochemical staining of CD8+ and T regulatory cells (Treg) or Foxp3+, yielding the CD8+/Treg ratio in individual patients. Changes in CD8+/Treg ratio before and after therapy were then correlated with pathobiological responses of individual patients based upon alterations of the Ki-67 labeling index (LI). A significant increase in the CD8+/Treg ratio was detected in responders (p=0.028) but not in non-responders, which may reflect the dynamic process in which the host immune response to tumor antigens changed in consequence of an interaction between tumor and stromal cells in its microenvironment following estrogen depletion caused by the AI. The CD8+/Treg ratio in breast cancer tissue can be a potential surrogate marker in surgical pathology specimens for predicting responses to neoadjuvant endocrine therapy, not only incorporating features of carcinoma cells as in Ki-67 LI but also those of adjacent stromal cells in the tumor microenvironment, especially in the early stage of treatment prior to any detectable clinical and/or histopathological changes.

Pivotal Cytoprotective Mediators and Promising Therapeutic Strategies for Endothelial Progenitor Cell-Based Cardiovascular Regeneration

Cardiovascular diseases (CVDs), including atherosclerosis, stroke, and myocardial infarction, is a major cause of death worldwide. In aspects of cell therapy against CVD, it is generally accepted that endothelial progenitor cells (EPCs) are potent neovascular modulators in ischemic tissues. In response to ischemic injury signals, EPCs located in a bone marrow niche migrate to injury sites and form new vessels by secreting various vasculogenic factors including VEGF, SDF-1, and FGF, as well as by directly differentiating into endothelial cells. Nonetheless, in ischemic tissues, most of engrafted EPCs do not survive under harsh ischemic conditions and nutrient depletion. Therefore, an understanding of diverse EPC-related cytoprotective mediators underlying EPC homeostasis in ischemic tissues may help to overcome current obstacles for EPC-mediated cell therapy for CVDs. Additionally, to enhance EPC's functional capacity at ischemic sites, multiple strategies for cell survival should be considered, that is, preconditioning of EPCs with function-targeting drugs including natural compounds and hormones, virus mediated genetic modification, combined therapy with other stem/progenitor cells, and conglomeration with biomaterials. In this review, we discuss multiple cytoprotective mediators of EPC-based cardiovascular repair and propose promising therapeutic strategies for the treatment of CVDs.

Therapeutic monoclonal antibodies and derivatives: Historical perspectives and future directions

Biologics, both monoclonal antibodies (mAbs) and fusion proteins, have revolutionized the practice of medicine. This year marks the 30th anniversary of the Food and Drug Administration approval of the first mAb for human use. In this review, we examine the biotechnological breakthroughs that spurred the explosive development of the biopharmaceutical mAb industry, as well as how critical lessons learned about human immunology informed the development of improved biologics. We also discuss the most common mechanisms of action of currently approved biologics and the indications for which they have been approved to date.

Radiochemotherapy-induced changes of tumour vascularity and blood supply estimated by dynamic contrast-enhanced CT and fractal analysis in malignant head and neck tumours

OBJECTIVE

To investigate radiochemotherapy (RChT)-induced changes of transfer coefficient (K(trans)) and relative tumour blood volume (rTBV) estimated by dynamic contrast-enhanced CT (DCE-CT) and fractal analysis in head and neck tumours (HNTs).

METHODS

DCE-CT was performed in 15 patients with inoperable HNTs before RChT, and after 2 and 5 weeks. The dynamics of K(trans) and rTBV as well as lacunarity, slope of log(lacunarity) vs log(box size), and fractal dimension were compared with tumour behaviour during RChT and in the 24-month follow-up.

RESULTS

In 11 patients, an increase of K(trans) and/or rTBV after 20 Gy followed by a decrease of both parameters after 50 Gy was noted. Except for one local recurrence, no tumour residue was found during the follow-up. In three patients with partial tumour reduction during RChT, a decrease of K(trans) accompanied by an increase in rTBV between 20 and 50 Gy was detected. In one patient with continuous elevation of both parameters, tumour progressed after RChT. Pre-treatment difference in intratumoral heterogeneity with its decline under RChT for the responders vs non-responders was observed.

CONCLUSION

Initial growth of K(trans) and/or rTBV followed by further reduction of both parameters along with the decline of the slope of log(lacunarity) vs log(box size) was associated with positive radiochemotherapeutic response. Increase of K(trans) and/or rTBV under RChT indicated a poor outcome.

ADVANCES IN KNOWLEDGE

The modification of K(trans) and rTBV as measured by DCE-CT may be applied for the assessment of tumour sensitivity to chose RChT regimen and, consequently, to reveal clinical impact allowing individualization of RChT strategy in patients with HNT.

Phase II evaluation of dalantercept, a soluble recombinant activin receptor-like kinase 1 (ALK1) receptor fusion protein, for the treatment of recurrent or persistent endometrial cancer: an NRG Oncology/Gynecologic Oncology Group Study 0229N

OBJECTIVE

This two-stage phase II study assessed activity of single agent dalantercept in patients with recurrent/persistent endometrial carcinoma (EMC).

METHODS

Eligible patients had persistent/recurrent EMC after 1-2 prior cytotoxic regimens, measurable disease (RECIST 1.1), and GOG performance≤2. Dalantercept 1.2mg/kg subcutaneous was administered once every 3weeks until disease progression (PD)/development of prohibitory toxicity. Primary objectives were to estimate the proportion of patients with persistent/recurrent EMC, who survive progression-free without receiving non-protocol therapy (TPFS) for at least 6months and to estimate the proportion having objective tumor response.

RESULTS

All 28 enrolled patients were eligible and evaluable. Median age: 62years. Most common histologies: 32% Grade 1/2 endometrioid and 54% serous tumors. Prior treatment: 1 or 2 regimens in 82% and 18% of patients, respectively. Eighteen patients received prior radiation therapy. Patients received 1-12 cycles of dalantercept, and 46% of patients received ≤2cycles. The most common adverse events (AE) were fatigue, anemia, constipation and peripheral edema. Grade 3/4 AEs occurred in 39% and 4% of patients. One grade 5 gastric hemorrhage in a patient with a history of radiation fibrosis/small bowel obstruction was deemed possibly dalantercept-related. All patients are off study: 86% for PD. No ORs were observed; 57% had stable disease and 11% had TPFS>6 mos. Median progression-free and overall survival: 2.1months (90% CI: 1.4-3.2) and 14.5months (90% CI: 7.0-17.5), respectively.

CONCLUSIONS

Dalantercept has insufficient single agent activity in recurrent EMC to warrant further investigation at this dose level and schedule.

Glipizide suppresses embryonic vasculogenesis and angiogenesis through targeting natriuretic peptide receptor A

Glipizide, a second-generation sulfonylurea, has been widely used for the treatment of type 2 diabetes. However, it is controversial whether or not glipizide would affect angiogenesis or vasculogenesis. In the present study, we used early chick embryo model to investigate the effect of glipizide on angiogenesis and vasculogenesis, which are the two major processes for embryonic vasculature formation as well as tumor neovascularization. We found that Glipizide suppressed both angiogenesis in yolk-sac membrane (YSM) and blood island formation during developmental vasculogenesis. Glipizide did not affect either the process of epithelial to mesenchymal transition (EMT) or mesoderm cell migration. In addition, it did not interfere with separation of smooth muscle cell progenitors from hemangioblasts. Moreover, natriuretic peptide receptor A (NPRA) has been identified as the putative target for glipizide׳s inhibitory effect on vasculogenesis. When NPRA was overexpressed or activated, blood island formation was reduced. NPRA signaling may play a crucial role in the effect of glipizide on vasculogenesis during early embryonic development.

Overexpression of miR‑145 in U87 cells reduces glioma cell malignant phenotype and promotes survival after in vivo implantation

In the present study, we sought to elucidate the effect of miR‑145 on glioma cell progression and its mechanisms of action. We examined the effects of miR‑145 on proliferation and invasion of U87 glioma cells and on capillary tube formation. Our data show that restoration of miR‑145 in U87 glioma cells significantly reduced their in vitro proliferation, invasion and angiogenesis. However, decreased miR‑145 expression promoted U87 glioma cell proliferation, invasion and angiogenesis, and reduced-expression of miR‑145 increased ADAM17 and EGFR expression in U87 cells. Overexpression of miR‑145 reduced ADAM17 and EGFR expression. VEGF secretion and VEGF expression were decreased by increased miR‑145 expression in U87 cells and were reversed by miR‑145 downregulation in vitro. Nude mice with intracerebral implantation of U87 overexpressing miR‑145 cells exhibited significantly reduced tumor growth and promoted survival compared with control groups. Taken together, these results suggest a role for miR‑145 as a tumor suppressor which inhibits glioma cell proliferation, invasion and angiogenesis in vitro and reduces glioma growth in vivo.

Correlation of tumor-infiltrative lymphocyte subtypes alteration with neoangiogenesis before and after neoadjuvant chemotherapy treatment in breast cancer patients

The two most important factors in tumor-stromal interactions are tumor-infiltrating lymphocytes (TIL) and neoangiogenesis (NAng). While changes of these parameters in responders of neoadjuvant chemotherapy (NCTx) have been reported, their correlation with pathological response in breast cancer (BC) patients treated with NCTx have not been described. We therefore evaluated alterations of the TIL subtypes ratio and alterations of NAng using the vasohibin-1-positive ratio (VPR) in BC patients during the course of NCTx. To this aim we used: (i) double immunohistochemistry of CD8 cytotoxic T cells and T regulatory cells (Treg) with Foxp3, determining the CD8+/Foxp3 ratio; (ii) immunostaining of CD31 and vasohibin-1, yielding the VPR, which reflects the NAng status. Changes between the CD8+/Foxp3 ratio and VPR before and after therapy were then correlated with the pathological response of the patients. A concomitant significant decrement of Foxp3 and NAng, represented by VPR, were detected only in NCTx pathological responders (p<0.001 and p=0.044, respectively). The CD8+/Foxp3 ratio increased in both responders and non-responders, but to greater extent in responders (p=0.02). The changes of VPR in the NCTx-treated group differed from those recorded for the patients treated with aromatase inhibitors and shown in our earlier study; this indicates that the reactions of the tumor-stromal interaction to therapy were different among different treatments in BC patients. Changes in Foxp3 and VPR in responders may reflect the dynamic activity of tumor stroma and host immune response to tumor antigens in the tumor microenvironment in response to the NCTx. VPR can be a potential surrogate marker in BC specimens for predicting the response to NCTx, incorporating both features of carcinoma and stromal cells.

Targeting tumor microenvironment: crossing tumor interstitial fluid by multifunctional nanomedicines

Introduction: The genesis of cancer appears to be a complex matter, which is not simply based upon few genetic abnormalities/alteration. In fact, irregular microvasculature and aberrant interstitium of solid tumors impose significant pathophysiologic barrier functions against cancer treatment modalities, hence novel strategies should holistically target bioelements of tumor microenvironment (TME). In this study, we provide some overview and insights on TME and important strategies used to control the impacts of such pathophysiologic barriers.

Methods: We reviewed all relevant literature for the impacts of tumor interstitium and microvasculature within the TME as well as the significance of the implemented strategies.

Results: While tumorigenesis initiation seems to be in close relation with an emergence of hypoxia and alterations in epigenetic/genetic materials, large panoplies of molecular events emerge as intricate networks during oncogenesis to form unique lenient TME in favor of tumor progression. Within such irregular interstitium, immune system displays defective surveillance functionalities against malignant cells. Solid tumors show multifacial traits with coadaptation and self-regulation potentials, which bestow profound resistance against the currently used conventional chemotherapy and immunotherapy agents that target solely one face of the disease.

Conclusion: The cancerous cells attain unique abilities to form its permissive microenvironment, wherein (a) extracellular pH is dysregulated towards acidification, (b) extracellular matrix (ECM) is deformed, (c) stromal cells are cooperative with cancer cells, (d) immune system mechanisms are defective, (e) non-integrated irregular microvasculature with pores (120-1200 nm) are formed, and (h) interstitial fluid pressure is high. All these phenomena are against cancer treatment modalities. As a result, to control such abnormal pathophysiologic traits, novel cancer therapy strategies need to be devised using multifunctional nanomedicines and theranostics.

Angiogenesis stimulated by human kallikrein-related peptidase 12 acting via a platelet-derived growth factor B-dependent paracrine pathway

KLK12, a kallikrein peptidase, is thought to take part in the control of angiogenesis. Our analysis of the secretome of endothelial cells (ECs) that had been treated with KLK12 showed that KLK12 converts the extracellular matrix- or membrane-bound precursor of platelet-derived growth factor B (PDGF-B) into a soluble form. Both PDGF-B and vascular endothelial growth factor A (VEGF-A) take part in the induction of angiogenesis by KLK12 in a coculture model of angiogenesis that mimics endothelial tubule formation. We used a cellular approach to analyze the interplay between KLK12, PDGF-B, and VEGF-A and showed that release of PDGF-B by KLK12 leads to the fibroblast-mediated secretion of VEGF-A. This then stimulates EC differentiation and the formation of capillary tube-like structures. Thus, KLK12 favors the interaction of ECs and stromal cells. The released PDGF-B acts as a paracrine factor that modulates VEGF-A secretion by stromal cells, which ultimately leads to angiogenesis. Moreover, the genes encoding KLK12 and PDGFB are both expressed in ECs and up-regulated in tumor cells kept under hypoxic conditions, which is consistent with the physiological involvement of KLK12 in PDGF-B maturation.

Angiogenesis and lymphangiogenesis in the spectrum of leprosy and its reactional forms

Background

Angiogenesis and lymphangiogenesis are the processes of neovascularization that evolve from preexisting blood and lymphatic vessels. There are few studies on angiogenesis and none on lymphangiogenesis in leprosy. Thus, the role of neovascularization in the pathophysiological mechanisms of the disease was studied across the spectrum of leprosy, its reactional states and its residual lesions.

Methodology/Principal Findings

Seventy-six biopsies of leprosy skin lesions and seven healthy controls were selected. Fifty-five serum samples were used for the detection of CD105 by ELISA. Histological sections were stained with antibodies against CD31 (blood and lymphatic vessels), D2-40/podoplanin (lymphatic vessels), and CD105/endoglin (neovessels). Microvessels were counted in 100 high-power fields (400x) and the number of vessels was evaluated in relation to the extension of the inflammatory infiltrate (0-3), to the bacillary index (0-6) and to the clinical forms. Angiogenesis, as marked by CD31 and CD105, was observed across the leprosy spectrum, compared with the controls. Additionally, there was a positive correlation between these markers with extension of the infiltrate (p <0.0001). For D2/40, lymphangiogenesis was observed in the tuberculoid form (p <0.0001). There was no statistical significance for values of CD105 detected in plasma by ELISA.

Conclusions/Significance

Angiogenesis is present across the spectrum of leprosy and in its reactional forms. The increase in the number of vessels, as detected by CD31 and CD105 staining, is related to the extension of the inflammatory infiltrate. Samples from reactional lesions have a higher number of CD31+ and CD105+ stained vessels, which indicates their involvement in the pathophysiological mechanisms of the reactional states. The regression of lesions is accompanied by the regression of neovascularization. Drugs inhibiting angiogenesis may be relevant in the treatment of leprosy, in addition to multidrugtherapy, and in the prevention of the development of reactions.

Inhibitory effects of antagonists of growth hormone-releasing hormone on growth and invasiveness of PC3 human prostate cancer

New approaches are needed to the therapy of advanced prostate cancer. This study determined the effect of growth hormone-releasing hormone (GHRH) antagonists, JMR-132 and JV-1-38 on growth of PC3 tumors as well as on angiogenesis and metastasis through the evaluation of various factors that contribute largely to the progression of prostate cancer. Human PC3 androgen-independent prostate cancer cells were injected subcutaneously into nude mice. The treatment with JMR-132 (10 μg/day) or JV-1-38 (20 μg/day) lasted 41 days. We also evaluated the effects of JMR-132 and JV-1-38 on proliferation, cell adhesion and migration in PC-3 cells in vitro. Several techniques (Western blot, reverse transcription polymerase chain reaction, immunohistochemistry, ELISA and zymography) were used to evaluate the expression levels of GHRH receptors and its splice variants, GHRH, vascular endothelial growth factor (VEGF), hypoxia inducible factor (HIF)-1α, metalloproteinases (MMPs) -2 and -9, β-catenin and E-cadherin. GHRH antagonists suppressed the proliferation of PC-3 cells in vitro and significantly inhibited growth of PC3 tumors. After treatment with these analogues, we found an increase in expression of GHRH receptor accompanied by a decrease of GHRH levels, a reduction in both VEGF and HIF-1α expression and in active forms of MMP-2 and MMP-9, a significant increase in levels of membrane-associated β-catenin and a significant decline in E-cadherin. These results support that the blockade of GHRH receptors can modulate elements involved in angiogenesis and metastasis. Consequently, GHRH antagonists could be considered as suitable candidates for therapeutic trials in the management of androgen-independent prostate cancer.

DCE-MRI: a review and applications in veterinary oncology

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a functional imaging technique that assesses the physiology of tumour tissue by exploiting abnormal tumour microvasculature. Advances made through DCE-MRI include improvement in the diagnosis of cancer, optimization of treatment choices, assessment of treatment efficacy and non-invasive identification of prognostic information. DCE-MRI enables quantitative assessment of tissue vessel density, integrity, and permeability, and this information can be applied to study of angiogenesis, hypoxia and the evaluation of various biomarkers. Reproducibility of DCE-MRI results is important in determining the significance of observed changes in the parameters. As improvements are made towards the utility of DCE-MRI and interpreting biologic associations, the technique will be applied more frequently in the study of cancer in animals. Given the importance of tumour perfusion with respect to tumour oxygenation and drug delivery, the use of DCE-MRI is a convenient and powerful way to gain basic information about a tumour.

Liposomes targeting tumour stromal cells

Liposomes have found clinical application in cancer therapy in the delivery of cytostatic agents. As a result of the targeted delivery of these toxic molecules to the tumour cells coupled to avoidance of toxicity-sensitive tissues, the therapeutic window is widened. Over the past years the focus of cancer therapy has shifted towards the stromal cells that are present in the tumour. It appears that clinically relevant tumours have acquired the ability to modulate the microenvironment in such a way that a chronic pro-inflammatory and pro-angiogenic state is achieved that contributes to invasion and metastasis and continued proliferation. Over the past years, liposomal formulations have been designed that target key stromal cell types that contribute to tumour growth. At the same time, many promising cell types have not been targeted yet and most of the studies employ drugs that aim at depleting stromal cells rather than modulating their activity towards an anti-tumour phenotype. In this review these target cell types will be addressed. Complementing these targeted formulations with the appropriate drugs to optimally suppress tumour-promoting signals while preserving anti-tumour action will be the challenge for the future.

NO (nitric oxide): the ring master

The migration and proliferation of endothelial cells affect the process of angiogenesis or the formation of blood vessels. Endothelial cells interact with each other to form ring-like structures in monolayers and tubular structures in matrigels. However, the transit phase between the individual endothelial cells and fully formed tubular structures is yet to be established. Guided by imaging, Western blot analysis, drug perturbation studies and siRNA studies we validate that endothelial ring structures are the fundamental and monomeric units of capillary tubes and nitric oxide is implicated in their fabrication. Giving input from experimental data, we used bagging classifier and information-gain to determine some of the physical and chemical parameters that define these biological structures. Further, we elucidated the implications of endothelial nitric oxide synthase and the NO/sGC/cGMP pathway in the formation of endothelial rings. We conclude that, formation of endothelial ring structure is important for angiogenesis and is mediated by the NO/sGC/cGMP pathway; and further endothelial rings can be used as in vitro models to study angiogenesis.

Usefulness of dynamic contrast enhanced computed tomography in patients with non-small-cell lung cancer scheduled for radiation therapy

OBJECTIVE

The goal of this study was to investigate the local tumor blood supply parameters relative tumor blood volume (rTBV) and transfer coefficient (K(trans)) measurable with dynamic contrast enhanced computed tomography (DCE-CT) in patients with non-small-cell lung cancer (NSCLC) scheduled for radiation therapy (RT).

MATERIALS AND METHODS

rTBV and K(trans) were measured before RT in 31 patients with clinically inoperable NSCLC (Stages I-III), which received (n=19) or did not receive (n=12) induction chemotherapy (IChT). Possible links between rTBV and K(trans) and time-to-progression (TTP), overall survival (OS) and maximum standardized uptake value (SUV(max)) from fluorodeoxyglucose positron emission tomography as well as histology were analyzed.

RESULTS

NSCLC showed a wide range of rTBV and K(trans) values as estimated by DCE-CT (6.4±0.6ml/100ml and 18.2±1.5ml/100ml/min correspondingly). A significant difference in rTBV values in patients with IChT (4.6±0.6ml/100ml) and without IChT (7.5±0.9ml/100ml; p=0.023), depending on the number of cycles of the IChT and the clinical stage was found. A negative correlation between rTBV and TTP was revealed only in RT patients up-staged by FDG-PET/CT from stage III to stage IV (n=7, r=-0.96, p=0.0006). An inverse correlation between K(trans) and TTP (n=24, r=-0.53, p=0.008) was observed in all RT patients. No relevant correlation was detected between rTBV, K(trans) and SUV(max) or histologic subtypes and grading.

CONCLUSIONS

Tumor blood supply parameters derived from DCE-CT are useful to characterize tumor vascularization before radiotherapy in patients with NSCLC and data on outcome prediction are supplemented.

Pathophysiology of placentation abnormalities in pregnancy-induced hypertension

During embryogenesis and development, the fetus obtains oxygen and nutrients from the mother through placental microcirculation. The placenta is a distinctive organ that develops and differentiates per se, and that organizes fetal growth and maternal condition in the entire course of gestation. Several life-threatening diseases during pregnancy, such as pregnancy-induced hypertension (PIH) and eclampsia, are closely associated with placental dysfunction. Genetic susceptibilities and poor placentation have been investigated intensively to understand the pathophysiology of PIH. It is currently thought that “poor placentation hypothesis”, in which extravillous trophoblasts fail to invade sufficiently the placental bed, explains in part maternal predisposition to this disease. Cumulative studies have suggested that hypoxic micromilieu of fetoplacental site, shear stress of uteroplacental blood flow, and aberrantly secreted proinflammatory substances into maternal circulation synergistically contribute to the progression of PIH. For example, soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble form of CD105 are elevated in circulation of PIH mothers. However, it remains to be poorly understood the pathological events in the placenta during the last half of gestation as maternal systemic disorders get worse. For better understanding and effective therapeutic approaches to PIH, it is important to clarify pathological course of PIH-associated changes in the placenta. In this review, current understanding of placental development and the pathophysiology of PIH placenta are summarized. In addition, recent findings of vasoactive signalings in PIH and rodent PIH models are discussed.

Microvessel density correlates with lymph node metastases and prognosis in hilar cholangiocarcinoma

BACKGROUND

Neovascularization was shown to be critically involved in the progression of multiple cancers, and treatment approaches targeting tumor-associated neovascularization provide convincing results in recent years in some tumor entities. However, little is known about the tumor-associated neovascularization in hilar cholangiocarcinoma. The present study was conducted to analyze tumor-associated neovascularization in hilar cholangiocarcinoma and to determine its influence on tumor growth, metastasis, recurrence, and prognosis.

METHODS

We analyzed tissue specimens of hilar cholangiocarcinoma (n = 60) by immunohistochemistry using the endothelial-specific antibody CD31 and subsequently quantified the microvessel density (MVD). The MVD was correlated with clinicopathological characteristics and recurrence pattern of the tumors as well as survival of patients.

RESULTS

Hilar cholangiocarcinoma revealed a high degree of vascularization, with a calculated mean MVD of 28.1 +/- 14.5 vessels. Tumors with a high MVD had a significant higher incidence of lymph node involvement (P = 0.009) and local recurrence (P < 0.001). Furthermore, a high MVD was identified to be a significant overall survival disadvantage (3-year, 28% vs. 93%; 5-year, 8% vs. 78%; P < 0.001) as well as disease-free survival disadvantage (3-year, 7% vs. 88%, 5-year, 7% vs. 72%; P < 0.001), with MVD representing an independent prognostic factor for survival.

CONCLUSIONS

Neovascularization is associated with nodal spread as well as local recurrence and serves as an independent prognostic factor for survival after curative resection of hilar cholangiocarcinoma. Therefore, tumor-associated neovascularization seems to be critically involved in the progression of this tumor entity. In addition, neovascularization may represent a potential target in he development of new therapeutic approaches in hilar cholangiocarcinoma.

Tumour vascularisation: a druggable target

Tumour growth, spreading and metastasis require the development of a local vasculature. There have been great advances in the understanding of how this new vasculature arises, particularly in our increased knowledge of the process of angiogenesis, Although, a vast number of pro-angiogenic and anti-angiogenic mediators have been identified, one of the key signalling processes in the development of the tumour vasculature is the hypoxia-induced stimulation of vascular endothelial cell growth factors (VEGFs) production. Anti-VEGF therapy therefore not only provides a new paradigm for limiting tumour growth via targeting angiogenesis, but also provides prototypic agents to test the hypothesis that by controlling the development of the tumour vasculature we are able to limit, and potentially stop, tumour growth and spreading.