Antiangiogenic effects of zoledronate on cancer neovasculature

Role of lymphocytes, macrophages and immune receptors in suppression of tumor immunity

Cancer is now the leading cause of mortality across the world. Inflammatory immune cells are functionally important in the genesis and progression of tumors, as demonstrated by their presence in human tumors. Numerous research has recently been conducted to determine if the innate and adaptive immune systems' cytotoxic cells can inhibit tumor growth and spread. Majority of cancers, when growing into identifiable tumors use multiple strategies to elude immune monitoring by lowering tumor immunity. Immunological suppression in the tumor microenvironment is achieved through interfering with antigen-presenting cells and effector T cells. Treatment of cancer requires managing both the tumor as well as tumor microenvironment (TME). Most patients will not be able to gain benefits from immunotherapy because of the immunosuppressive tumor microenvironment. The actions of many stromal myeloid and lymphoid cells are regulated to suppress tumor-specific T lymphocytes. These frequently exhibit inducible suppressive processes brought on by the same anti-tumor inflammatory response the immunotherapy aims to produce. Therefore, a deeper comprehensive understanding of how the immunosuppressive environment arises and endures is essential. Here in this chapter, we will talk about how immune cells, particularly macrophages and lymphocytes, and their receptors affect the ability of tumors to mount an immune response.

Systematic evaluation of the mechanisms of zoledronic acid based on network pharmacology

Zoledronic acid (ZA) is an FDA-approved drug and a third-generation bisphosphonate (BPs). A systematic evaluation of the mechanisms of ZA has not previously been performed. In this study, validated targets of ZA were screened using PubChem, Herbal Ingredients' Targets Database (HIT), Binding Database (BindingDB), and ChemBank, and potential targets of ZA were identified based on structural characteristics of ligands and proteins. The candidate targets were then assessed using GeneMANIA, Gene Ontology (GO), and pathway analysis, and molecule-target-GO-pathway networks were visualized using Cytoscape. Nine validated targets and 26 potential targets were obtained. The networks generated via this analysis showed that the candidate targets were associated with cell proliferation and metabolism as well as other biological processes (BP) and pathways. In general, ZA appeared to play crucial roles in multiple functions, including metabolism, regulation of vascular smooth muscle cell proliferation, and chemical carcinogenesis; a great deal of additional research must be performed. Moreover, the current study showed that it is feasible to analyze the mechanisms of ZA via target prediction, which facilitates systematic pharmacological evaluation.

Tumor-associated macrophages in tumor metastasis: biological roles and clinical therapeutic applications

Tumor metastasis is a major contributor to the death of cancer patients. It is driven not only by the intrinsic alterations in tumor cells, but also by the implicated cross-talk between cancer cells and their altered microenvironment components. Tumor-associated macrophages (TAMs) are the key cells that create an immunosuppressive tumor microenvironment (TME) by producing cytokines, chemokines, growth factors, and triggering the inhibitory immune checkpoint proteins release in T cells. In doing so, TAMs exhibit important functions in facilitating a metastatic cascade of cancer cells and, meanwhile, provide multiple targets of certain checkpoint blockade immunotherapies for opposing tumor progression. In this article, we summarize the regulating networks of TAM polarization and the mechanisms underlying TAM-facilitated metastasis. Based on the overview of current experimental evidence dissecting the critical roles of TAMs in tumor metastasis, we discuss and prospect the potential applications of TAM-focused therapeutic strategies in clinical cancer treatment at present and in the future.

Tumor-associated macrophages in tumor metastasis: biological roles and clinical therapeutic applications

Tumor metastasis is a major contributor to the death of cancer patients. It is driven not only by the intrinsic alterations in tumor cells, but also by the implicated cross-talk between cancer cells and their altered microenvironment components. Tumor-associated macrophages (TAMs) are the key cells that create an immunosuppressive tumor microenvironment (TME) by producing cytokines, chemokines, growth factors, and triggering the inhibitory immune checkpoint proteins release in T cells. In doing so, TAMs exhibit important functions in facilitating a metastatic cascade of cancer cells and, meanwhile, provide multiple targets of certain checkpoint blockade immunotherapies for opposing tumor progression. In this article, we summarize the regulating networks of TAM polarization and the mechanisms underlying TAM-facilitated metastasis. Based on the overview of current experimental evidence dissecting the critical roles of TAMs in tumor metastasis, we discuss and prospect the potential applications of TAM-focused therapeutic strategies in clinical cancer treatment at present and in the future.

Atorvastatin increases oxidative stress and inhibits cell migration of oral squamous cell carcinoma in vitro

OBJECTIVE

This study aimed to evaluate the effect of atorvastatin treatment on reactive oxygen species (ROS) production and tumor angiogenesis in oral squamous cell carcinomas.

MATERIAL AND METHODS

An HN13 cell line was treated with 1 µM, 5 µM, and 10 µM of atorvastatin. VEGF-A gene expression was evaluated by quantitative real time PCR. VEGF-A protein expression was quantified from total protein and conditioned media by ELISA. Cellular oxidative stress was measured using 2',7'-dichlorfluorescein-diacetate (DCFH-DA). Angiogenesis assay was performed using human umbilical vein endothelial cells (HUVEC). The effect of atorvastatin on cell migration was evaluated by wound healing assay.

RESULTS

5 µM and 10 µM of atorvastatin significantly increased VEGF-A gene expression in the HN13 cell line. Intracellular expression of the VEGF-A protein was higher in the cells treated with 5 µM and 10 µM than in the control cells. VEGF-A protein expression was also higher in the conditioned media from the atorvastatin-treated cells than in the media from the DMSO-treated cells. 5 µM and 10 µM of atorvastatin increased oxidative stress. Regarding angiogenesis assay, 5 µM of atorvastatin resulted in higher numbers of branch points, compared to the solvent. 10 µM of atorvastatin treatment resulted in significantly reduced cell migration.

CONCLUSIONS

This study showed that atorvastatin increases the oxidative stress and angiogenesis in oral squamous cell carcinomas. The decrease of cell migration indicates atorvastatin's inhibitory effect in oral tumors. These results suggest that atorvastatin could increase the intracellular oxidative stress in these cells, leading to a toxic microenvironment and inhibiting their metastasis.

Nitrogen-containing bisphosphonate therapy-Part II: Assessment of alveolar bone tissue inflammatory response in rats-A blind randomized controlled trial

This study aimed to evaluate the alveolar bone tissue inflammatory response in rats undergoing zoledronic acid therapy. The study sample was composed of 28 Wistar rats. Animals from the test group GTa received a weekly intraperitoneal dose of 0.2 mg/kg of zoledronic acid for 3 weeks, while test group GTb received the same dose for 8 weeks. A physiological saline dose, equivalent to that of the medication, was administered to the controls in groups GCa and GCb. A defect was created in the dental crown of the lower first molars using a drill to simulate pulp and periapical injury. Data were evaluated regarding image grey levels by cone-beam computed tomography and histologically by assigning scores for the presence of inflammatory infiltrate, type of infiltrate, vascularization, bone necrosis and dental resorption. Grey levels in the 3-week therapy group (GTa) showed more pronounced changes in comparison with those seen in the GCa group (P < 0.05). Evaluation of the scores demonstrated no association between any of the variables amongst the groups (>0.05). However, bone remodelling decreased in the groups receiving the medication. Bone necrosis was present more frequently in group GTb than in the control group GCb. The results suggest that the drug interfered in the reaction capacity of the alveolar bone tissue as test group GTa showed higher grey levels in comparison to the control group GCa. In addition, there was less bone remodelling activity, with the appearance of bone necrosis zones and intense acute inflammatory infiltrate associated with the 8-week therapy group GTb.

Prognostic impact of blood and urinary angiogenic factor levels at diagnosis and during treatment in patients with osteosarcoma: a prospective study

Background

Angiogenesis is essential for the progression and metastatic spread of solid tumours. Expression of vascular endothelial growth factor (VEGF) has been linked to poor survival among osteosarcoma patients but the clinical relevance of monitoring blood and urine angiogenic factors is uncertain. The aim of this study was to determine the prognostic significance of blood VEGF and blood and urinary basic fibroblast growth factor (bFGF) levels in osteosarcoma patients, both at diagnosis and during treatment.

Methods

Patients with localised or metastatic osteosarcoma enrolled in OS2005 and OS2006 studies between 2005 and 2011 were prospectively included in this study. VEGF and bFGF levels in serum and plasma and bFGF levels in urine were measured by ELISA at diagnosis, before surgery, and at the end of treatment. Endpoints considered for the prognostic analysis were histological response, progression-free and overall survival. Kruskal-Wallis tests were used to compare the distribution of baseline biomarker values across the different subgroups, and paired sample Wilcoxon rank tests were used to analyze changes over time. Association between biomarker levels and outcomes were assessed in multivariable models (logistic regression for histologic response, and Cox models for survival).

Results

Samples were available at diagnosis for 269 patients (54% males; age ≤ 18 years: 73%; localised disease in 68%, doubtful lung lesions in 17%, and metastases in 15%). High serum VEGF and bFGF levels were observed in respectively 61% and 51% of patients. Serum and plasma VEGF values were not strongly correlated with one another (r = 0.53). High serum and plasma VEGF levels were significantly more frequent in patients with large tumours (≥10 cm; p = 0.003 and p = 0.02, respectively). VEGF levels fell significantly during pre-operative chemotherapy (p < 0.0001). No significant correlation was found between this variation and either the histological response, progression-free survival or overall survival (p = 0.26, p = 0.67, and p = 0.87, respectively). No significant association was found between blood or urinary bFGF levels and clinical characteristics, histological response, or survival.

Conclusions

Levels of VEGF and bFGF angiogenic factors are high in most osteosarcoma patients, but have no significant impact on response to chemotherapy or outcome in this large prospective series.

OS 2006 trial registration number

clinicaltrials.gov NCT00470223; date of registration: May 3th 2007.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3409-z) contains supplementary material, which is available to authorized users.

Treatment and prognosis of bone metastasis from cervical cancer (KCOG-G1202s)

AIM

The early and precise diagnosis and proper palliative treatment of bone metastasis is important for improving the quality of life of cervical cancer patients. The aim of this study was to clarify the clinical features, treatment modalities and prognosis of bone metastasis in cervical cancer patients in Japan.

METHODS

The medical records of 75 cervical cancer patients with bone metastasis who were treated between January 2000 and December 2010 were retrospectively analyzed in a multi-institutional study.

RESULTS

Fifty-four patients (72.0%) had a single bone metastasis. Bone metastases were found in the spine (46.7%) and pelvis (42.7%). Forty-three patients (57.3%) also had extra-osseous metastases. Most of the patients received radiotherapy, chemotherapy or both, but 25 patients (33.3%) received palliative care only. Bisphosphonates were given as palliative therapy to 25 patients (33.3%). The median overall survival after the diagnosis of bone metastasis was significantly shorter in patients with extra-osseous metastases than in those without extra-osseous metastases (14 vs 5 months; P < 0.05). The survival of patients who received chemotherapy following radiotherapy or concurrent chemoradiotherapy was significantly longer than that of the patients who received palliative care. On multivariate analysis, the presence of extra-osseous metastasis was an independent predictor of survival in patients with bone metastasis from cervical cancer.

CONCLUSIONS

Multidisciplinary treatment might improve the prognosis of patients with bone metastasis who do not have extra-osseous lesions.

Regulation of VEGF by mevalonate pathway inhibition in breast cancer

Aminobisphosphonates are used for the treatment of benign and malignant bone disorders. As inhibitors of the mevalonate pathway they exert direct anti-tumor effects in vitro and in preclinical models of bone metastases. Bisphosphonates are thought to have an anti-angiogenic activity as decreased levels of VEGF have been reported in some, although not all patients, following treatment with bisphosphonates. Direct effects of bisphosphonates on tumor derived VEGF have not been examined in detail. We therefore investigated VEGF expression in breast cancer cell lines following mevalonate pathway inhibition. Treatment of cell lines with increasing doses of zoledronic acid and atorvastatin resulted in increased levels of VEGF production. Similar results were seen with the geranylgeranyltransferase I inhibitor GGTI-298. The induction of VEGF was reversed by the supplementation of geranylgeranyl pyrophosphate but not by farnesyl pyrophosphate indicating that this effect is mediated by inhibited geranylgeranylation. Previous reports have reported decreased VEGF levels in patients following BP treatment in vivo. We assessed VEGF levels in patients with non-metastatic breast cancer following repeated treatment with zoledronic acid. In contrast to our in vitro findings, VEGF serum levels decreased in all patients after 6–9 months of treatment (by an average of 41%) as assessed in a small pilot trial. These results indicate that tissues other than breast tumors contribute to the serum pool of circulating VEGF and may be responsible for the observed VEGF decreases. The increases of VEGF in the cancer cells may provide a rationale for the combined treatment with VEGF inhibitors.

The effects of zoledronic acid in the bone and vasculature support of hematopoietic stem cell niches

Hematopoietic stem cells (HSC) are maintained in a tightly regulated bone microenvironment constituted by a rich milieu of cells. Bone cells such as osteoblasts are associated with niche maintenance as regulators of the endosteal microenvironment. Bone remodeling also plays a role in HSC mobilization although it is poorly defined. The effects of zoledronic acid (ZA), a potent bisphosphonate that inhibits bone resorption, were investigated on bone marrow cell populations focusing on HSCs, and the endosteal and vascular niches in bone. ZA treatment significantly increased bone volume and HSCs in both young and adult mice (4 week and 4 month old, respectively). ZA increased vessel numbers with no overall change in vascular volume in bones of young and had no effect on vasculature in adult mice. Since both young and adult mice had increased HSCs and bone mass with differing vasculature responses, this suggests that ZA indirectly supports HSCs via the osteoblastic niche and not the vascular niche. Additionally, gene expression in Lin- cells demonstrated increased expression of self-renewal-related genes Bmi1 and Ink4a suggesting a role of ZA in the modulation of cell commitment and differentiation toward a long-term self-renewing cell. Genes that support the osteoblastic niche, BMP2 and BMP6 were also augmented in ZA treated mice. In conclusion, ZA-induced HSC expansion occurs independent of the vascular niche via indirect modulation of the osteoblastic niche.