Vascular endothelial growth factor and bevacitumab in breast cancer

Generation and characterization of 7DC-DM1: a non-cleavable CD47-targeting antibody-drug conjugates with antitumor effects

Colorectal cancer is the second leading cause of cancer-related deaths following lung cancer in recent years. Therefore, lung or colorectal cancer therapy is very important for reducing mortality. In this study, we developed and characterized CD47-specific antibody-drug conjugates, namely 7DC-DM1 ADCs, to evaluate their therapeutic effects on lung and colorectal cancer. Both 7DC2-DM1 and 7DC4-DM1 demonstrated good binding affinities of 0.56 nM and 0.49 nM, respectively, and exhibited significant cytotoxicity, though they displayed different penetration effects. These findings suggest that the binding complexes of 7DC2-DM1 and 7DC4-DM1 with CD47 receptors adopt different conformations, leading to variations in their cellular internalized efficiencies. Molecular docking simulations revealed that 7DC2 and 7DC4 bind to CD47 molecules in distinct orientations and epitopes, differing between conserved and non-conserved regions. Furthermore, treatments with 7DC2-DM1 and 7DC4-DM1 displayed notable differences in antitumor effects in murine syngeneic tumor models derived from the MC38 cell line in C57BL/6 mice. In the tumor model treated with 7DC4-DM1, immunofluorescence staining analysis revealed a large area of necrosis in the tumor stroma, accompanied by a significant infiltration of CD11b-expressing immune cells. In summary, these results indicate that 7DC4-DM1 holds promise as a therapeutic agent for colorectal cancer treatment.

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.

The role of VEGF in cancer-induced angiogenesis and research progress of drugs targeting VEGF

Angiogenesis is a double-edged sword; it is a mechanism that defines the boundary between health and disease. In spite of its central role in physiological homeostasis, it provides the oxygen and nutrition needed by tumor cells to proceed from dormancy if pro-angiogenic factors tip the balance in favor of tumor angiogenesis. Among pro-angiogenic factors, vascular endothelial growth factor (VEGF) is a prominent target in therapeutic methods due to its strategic involvement in the formation of anomalous tumor vasculature. In addition, VEGF exhibits immune-regulatory properties which suppress immune cell antitumor activity. VEGF signaling through its receptors is an integral part of tumoral angiogenic approaches. A wide variety of medicines have been designed to target the ligands and receptors of this pro-angiogenic superfamily. Herein, we summarize the direct and indirect molecular mechanisms of VEGF to demonstrate its versatile role in the context of cancer angiogenesis and current transformative VEGF-targeted strategies interfering with tumor growth.

Uncarboxylated osteocalcin promotes proliferation and metastasis of MDA-MB-231 cells through TGF-β/SMAD3 signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC) is the most severe type of breast cancer owing to its high heterogeneity, aggressiveness and lack of treatment. Studies have reported that uncarboxylated osteocalcin (GluOC) promotes the development of prostate and other cancers. Studies have also found elevated levels of serum osteocalcin in breast cancer patients with bone metastasis, and serum osteocalcin can be a marker of bone metastasis. However, whether GluOC promotes the development of TNBC and the related mechanisms need to be further clarified.

RESULTS

Our results revealed that GluOC is associated with the proliferation and metastasis of MDA-MB-231 cells. GluOC increased the viability and proliferation of MDA-MB-231 cells. In addition, GluOC enhanced the metastatic ability of MDA-MB-231 cells by promoting the expression of matrix metalloproteinase-2 (MMP2), matrix metalloproteinase-13 (MMP13), and vascular endothelial growth factor (VEGF) and inducing epithelial-mesenchymal transition (EMT). We also found that GluOC upregulated the expression of interleukin-8 (IL-8) and parathyroid hormone-related protein (PTHrP) genes in MDA-MB-231 breast cancer cells. Moreover, the promoting effect of GluOC was reversed in MDA-MB-231 breast cancer cells treated with specific inhibitor of SMAD3 (SIS3), a SMAD3 phosphorylation inhibitor.

CONCLUSION

Our research proved for the first time that GluOC facilitates the proliferation and metastasis of MDA-MB-231 cells by accelerating the transforming growth factor-β (TGF-β)/SMAD3 signaling pathway. Moreover, GluOC also promotes the gene expression of IL-8 and PTHrP. Both IL-8 and PTHrP can act as osteolytic factors in breast cancer cells. This study indicates that GluOC may be a useful target for preventing TNBC bone metastasis.

Cooperation between Angiogenesis, Vasculogenesis, Chemotaxis, and Coagulation in Breast Cancer Metastases Development: Pathophysiological Point of View

Simple Summary

Breast cancer is one of the main causes of morbidity and mortality in women. Early breast cancer has a relatively good prognosis, in contrast to metastatic disease with rather poor outcomes. Metastasis formation in distant organs is a complex process requiring cooperation of numerous cells, growth factors, cytokines, and chemokines. Tumor growth, invasion, and finally systemic spread are driven by processes of angiogenesis, vasculogenesis, chemotaxis, and coagulation. This review summarizes their role in development of distant metastases in breast cancer, as well as explains the essential processes occurring throughout these actions.

Abstract

With almost 2.3 million new cases and 685 thousand fatal events in 2020 alone, breast cancer remains one of the main causes of morbidity and mortality in women worldwide. Despite the increasing prevalence of the disease in recent years, the number of deaths has dropped—this is mostly the result of better diagnostic and therapeutic opportunities, allowing to recognize and treat breast cancer earlier and more efficiently. However, metastatic disease still remains a therapeutic challenge. As mechanisms of tumor spread are being explored, new drugs can be implemented in clinical practice, improving the outcomes in patients with advanced disease. Formation of metastases is a complex process, which involves activation of angiogenesis, vasculogenesis, chemotaxis, and coagulation. The actions, which occur during metastatic spread are interrelated and complementary. This review summarizes their importance and mutual connections in formation of secondary tumors in breast cancer.

Innovative Betulin Nanosuspension exhibits enhanced anticancer activity in a Triple Negative Breast Cancer Cell line and Zebrafish angiogenesis model

We present a nanosuspension of betulin, a BCS class II anticancer drug, particularly effective against resistant breast cancer. As anticancer efficacy of betulin is hampered by poor aqueous solubility, a nanosuspension with surface area was considered to enhance efficacy. An innovative approach wherein the betulin nanosuspension is generated instantaneously in situ, by adding a betulin preconcentrate (BeTPC) comprising drug and excipients, to aqueous medium, is successfully demonstrated. The optimal BeTPC when added to isotonic dextrose solution instantaneously generated an in situ nanosuspension (BeTNS-15) with high precipitation efficiency (92.7 ± 1.21%), average particle size (383.74 ± 7.24 nm) and good stability as per ICH guidelines. TEM revealed elongated particles while DSC and XRD indicated partial amorphization. Significantly higher cytotoxicity of BeTNS-15 (IC₅₀ 38.44 µg/ml) compared to betulin (BetS) (IC₅₀ 69.54 µg/ml) in the resistant triple negative human breast cancer cell line MDA-MB-231, was attributed to high intracellular uptake confirmed by HPLC and Imaging Flow cytometry (IFC). IFC confirmed superior anti-cancer efficacy of BeTNS-15 mediated by mitochondrial membrane disruption and inhibition of the G0/G1 phase. BeTNS-15 also exhibited significantly greater anti-angiogenic efficacy (p < 0.05) in the zebrafish model confirming superior efficacy. Simplicity of the innovative in situ approach coupled with superior efficacy proposes BeTNS as an innovative and highly promising anticancer formulation.

Upregulated osterix promotes invasion and bone metastasis and predicts for a poor prognosis in breast cancer

Approximately 70% of patients with advanced breast cancer develop bone metastases, accompanied by complications, such as bone pain, fracture, and hypercalcemia. However, our understanding of the molecular mechanisms that govern this process remains fragmentary. Osterix (Osx) is a zinc finger-containing transcription factor essential for osteoblast differentiation and bone formation. Here, we identified the functional roles of Osx in facilitating breast cancer invasion and bone metastasis. Osx upregulation was associated with lymph node metastasis and was negatively prognostic for overall survival. Knockdown of Osx inhibited invasion of breast cancer and osteolytic metastasis by downregulating MMP9, MMP13, VEGF, IL-8, and PTHrP, which are involved in invasion, angiogenesis, and osteolysis; overexpression of Osx had the opposite effect. Moreover, MMP9 was a direct target of Osx and mediated the Osx-driven invasion of breast cancer cells. Together, our data showed that Osx facilitates bone metastasis of breast cancer by upregulating the expression of a cohort of genes that contribute to steps in the metastatic cascade. These findings suggest that Osx is an attractive target for the control of bone metastasis of breast cancers.

Analysis of the activity and safety of weekly low-dose bevacizumab-based regimens in heavily pretreated patients with metastatic breast cancer

Background

Currently, there are no standard regimens for metastatic breast cancer patients (MBC) who have failed ≥ 3 chemotherapy treatments. The aim of this study was to assess whether weekly low‐dose bevacizumab‐based regimens were well tolerated and would improve efficacy in MBC patients who had failed numerous therapies.

Methods

Seventeen patients with MBC who were heavily pretreated with a median of five regimens of therapy (range 1–10) between 2012 and 2016 were included in the analysis. Bevacizumab was administered at a dose of 100 mg intravenously once a week combined with one or two types of chemotherapeutic drugs until confirmed disease progression or an intolerable adverse event was observed. Patient characteristics, objective response rate, clinical benefit rate, progression‐free survival, and toxicity were assessed.

Results

All 17 patients had been pretreated with taxane‐based and anthracycline‐based chemotherapy. Weekly low‐dose bevacizumab combined with one or two types of chemotherapeutic drugs, which had usually not been previously used (e.g. etoposide, irinotecan, pemetrexed, methotrexate, and nab‐paclitaxel), was administered. Three patients achieved a partial response, while one had stable disease for > 24 weeks, and the clinical benefit rate was 23.5%. Median progression‐free survival was 3.4 months (95% confidence interval 2.0–4.8). The most common hematological adverse events were neutropenia, anemia, and thrombocytopenia. Bevacizumab‐related adverse events included grade 1 bleeding (17.6%) and grade 2 hypertension (5.9%).

Conclusions

Weekly low‐dose bevacizumab combined with chemotherapy shows a relatively favorable clinical response and tolerable toxicity, providing a feasible option for heavily pretreated MBC patients.

Anti-angiogenic treatment in breast cancer: Facts, successes, failures and future perspectives

Angiogenesis is one of the hallmarks of cancer and a crucial requisite in the development of tumors. Interrupting this process by blocking the vascular endothelial growth factor (VEGF) with the monoclonal antibody bevacizumab has been considered a possible breakthrough in the treatment of various types of cancer, especially for advanced disease. However in breast cancer, studies have shown ambivalent results causing debate about the value of this drug. In this article, we review the evidence for anti-angiogenic treatment options for breast cancer, as well as discuss the possible factors limiting the effectiveness of anti-angiogenic agents and offer a recommendation regarding the future research on these therapies for the treatment of breast cancer.

Triple-negative breast carcinoma: current and emerging concepts

OBJECTIVES

Triple-negative breast cancer is regarded as an aggressive disease that affects a young patient population and for which effective targeted therapy is not yet available.

METHODS

Intense efforts have been made to gain a better understanding of this heterogeneous group of tumors from the histologic to the genomic and molecular levels.

RESULTS

Progress has been made, including the ability to subtype these tumors and the discovery of biomarkers toward which current therapeutic efforts are focused. Many novel targets under exploration have the potential to affect the clinical course of this disease.

CONCLUSIONS

This article reviews the current concepts regarding the clinicopathologic features of triple-negative breast carcinoma, its histologic subtypes, molecular classification, the prognostic and therapeutic potential of biomarkers, and emerging targeted therapies.

Small activating RNA restores the activity of the tumor suppressor HIC-1 on breast cancer

HIC-1 is a gene that is hypermethylated in cancer, and commonly downregulated in human breast cancer. However, the precise mechanisms and molecular pathways regulated by HIC-1 remain unclear. We assessed HIC-1 expression on a tissue microarray containing 80 cases of breast cancer. We also analyzed its biological function by restoring HIC-1 expression using 5-aza-2′ deoxycytidine (5-CdR) and small-activating RNAs for the reversal of HIC-1 tumor suppressive effects on MCF-7 and MDA-MB-231 cell lines. An Agilent Q44h global expressing microarray was probed after restoring the expression of HIC-1. Data demonstrated that HIC-1 expression was reduced significantly in breast cancer tissues. HIC-1 immunohistochemistry resulted in mean staining scores in cancer tissue and normal ductal epithelia of 3.54 and 8.2, respectively (p<0.01). 5-CdR partially reversed HIC-1 expression, and modulated cell growth and apoptosis. dsHIC1-2998, an saRNA, showed activating efficacy in breast cancer cells. A group of differentially expressed genes were characterized by cDNA microarray. Upon saRNA treatment, genes upregulated included those involved in immune activation, cell cycle interference, the induction of apoptosis, anti-metastasis, and cell differentiation. Downregulated genes included oncogenes and those that play roles in cell invasion, cell growth, and cell division. Our findings may provide valuable resources not only for gene functional studies, but also for potential clinical applications to develop novel drug targets.

Dyskerin depletion increases VEGF mRNA internal ribosome entry site-mediated translation

Dyskerin is a nucleolar protein encoded by the DKC1 gene that (i) stabilizes the RNA component of the telomerase complex, and (ii) drives the site-specific pseudouridilation of rRNA. It is known that the partial lack of dyskerin function causes a defect in the translation of a subgroup of mRNAs containing internal ribosome entry site (IRES) elements such as those encoding for the tumor suppressors p27 and p53. In this study, we aimed to analyze what is the effect of the lack of dyskerin on the IRES-mediated translation of mRNAs encoding for vascular endothelial growth factor (VEGF). We transiently reduced dyskerin expression and measured the levels of the IRES-mediated translation of the mRNA encoding for VEGF in vitro in transformed and primary cells. We demonstrated a significant increase in the VEGF IRES-mediated translation after dyskerin knock-down. This translational modulation induces an increase in VEGF production in the absence of a significant upregulation in VEGF mRNA levels. The analysis of a list of viral and cellular IRESs indicated that dyskerin depletion can differentially affect IRES-mediated translation. These results indicate for the first time that dyskerin inhibition can upregulate the IRES translation initiation of specific mRNAs.

Low-dose docetaxel combined with (-)-epigallocatechin-3-gallate inhibits angiogenesis and tumor growth in nude mice with gastric cancer xenografts

Low-dose metronomic (LDM) chemotherapy represents a new strategy to treat solid tumors by stronger antiangiogenic activity and less side-effects, especially in combination with other antiangiogenic agents. The aim of the study is to investigate the antiangiogenic effect of docetaxel alone and combined with (-)-epigallocatechin-3-gallate (EGCG) in preclinical settings of gastric cancer. BGC-823 human gastric cancer xenograft model was used, and tumor growth, side-effects of mice were closely monitored. Expression of vascular endothelial growth factor and CD31 were observed by immunohistochemistry, and microvessel density of the tumor tissues was assessed by CD31 immunohistochemical analysis. Our results indicated that LDM docetaxel inhibited angiogenesis and growth of gastric cancer with less toxicity, and the effects were further enhanced by the concurrent administration of EGCG. Our study, for the first time, rationally demonstrated that LDM docetaxel treatment used alone or combined with EGCG is effective and safe in preclinical settings of gastric cancer. Our data suggest that LDM docetaxel used alone or combined with EGCG may be an innovative and promising therapeutic strategy in the experimental treatment of human gastric cancer.

Intraocular bevacizumab levels 24 hours after intravitreal injection in a normal eye

BACKGROUND

To determine intraocular levels of bevacizumab in a normal eye 24 hours after the injection of bevacizumab into the vitreous cavity.

METHODS

Fluid and tissue samples were analyzed for unbound bevacizumab levels using microsphere immunoassays.

RESULTS

After a loading dose of 2.5 mg (0.1 mL) of bevacizumab, levels of unbound drug could be detected in all tissue extracts 24 hours after its injection. At least 60.2% of the injected bevacizumab could be accounted for in this study. Levels of 0.06 mg (2.4%) of bevacizumab were recorded in the choroid.

CONCLUSION

At 24 hours, unbound bevacizumab levels can be detected at the level of the choroid. Therefore, bevacizumab can reach the site where choroidal neovascularization develops. This explains its reported therapeutic effect.

Angiogenesis and breast cancer

Angiogenesis is an essential step for breast cancer progression and dissemination. The development of new blood vessels in cancer setting (angiogenesis) is conducted by numerous physiological and pathological stimuli, where the main stimulus is hypoxia. The knowledge of different molecular pathways regulating angiogenesis is constantly growing. An increased and complex scenario of angiogenesis is nowadays available in breast cancer, specifically, and permits not only to understand most of the important phases of neoplastic growth but also offer an exciting perspective for new therapeutic proposals based on blocking new blood vessels sprouting. This review focused on historical and recent understanding of angiogenesis occurrence in breast cancer.

Triple-negative breast cancer: role of antiangiogenic agents

New blood vessel formation plays an important role in breast cancer growth, invasion, and metastasis. Tumor growth is preceded by the development of new blood vessels, which provide a pathway for metastases and nutrients essential for growth. Vascular endothelial growth factor (VEGF) is a key angiogenic mediator that stimulates endothelial cell proliferation and regulates vascular permeability. Highly proliferative tumors, such as those that are negative for the estrogen, progesterone, and HER2/neu receptors have enhanced angiogenesis that supports rapid growth and early metastases and have been found to have high levels of VEGF. Drugs developed to inhibit the angiogenic process may be particularly effective in triple-negative breast cancer. Subset analyses have demonstrated efficacy with combinations of the VEGF antibody bevacizumab in combination with chemotherapy and, to a limited degree, with other antiangiogenic agents. Many targeted biologic agents in development inhibit angiogenesis including those that inhibit the mammalian target of rapamycin, fibroblast growth factor, Notch, hypoxic inducible factor, 2-methoxyestradiol, insulin like growth factor, matrix metalloproteinase, and others. Ongoing studies are focusing on the effects of these agents in triple-negative disease, and there is an urgent need to identify markers that can predict response to specific targeted therapy.

Vascular endothelial growth factor and its relationship to the prognosis and treatment of breast, ovarian, and cervical cancer

Tumor neovascularization is a complex process that plays a crucial role in the development of many different types of cancer. Vascular endothelial growth factor (VEGF) is a potent mitogen that is involved with mitogenesis, angiogenesis, endothelial survival, and the induction of hematopoiesis. By increasing vascular permeability in endothelial cells, it helps tumors recruit wound-healing proteins fibrin and fibrinogen from the plasma, suggesting that tumor formation is a process of abnormal wound healing dependent on the ability to generate a blood supply. The human female reproductive tract is highly dependent on VEGF for normal functions such as endometrial proliferation and development of the corpus luteum. The unique influence of female sex steroid hormones on the expression and activity of VEGF deems angiogenesis an important facet of the development of breast and ovarian cancer. Additionally, the up-regulation of VEGF by the E6 oncoprotein of the human papillomavirus suggests that VEGF plays an important role in the development of cervical cancer. Clinical trials have investigated the humanized monoclonal antibody bevacizumab as potential treatment for all three forms of cancer; the data show that in breast cancer, the use of bevacizumab may lengthen the disease-free survival for women with advanced breast cancer, but does not appear to change their overall survival. It may have a role as salvage chemotherapy for ovarian and cervical cancer, though further research is needed to establish it as a definitive form of treatment.

Multidisciplinary functional MR imaging for prostate cancer

Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer.

Lymphangiogenesis and lymphatic metastasis in breast cancer

Lymphatic metastasis is the main prognostic factor for survival of patients with breast cancer and other epithelial malignancies. Mounting clinical and experimental data suggest that migration of tumor cells into the lymph nodes is greatly facilitated by lymphangiogenesis, a process that generates new lymphatic vessels from pre-existing lymphatics with the aid of circulating lymphatic endothelial progenitor cells. The key protein that induces lymphangiogenesis is vascular endothelial growth factor receptor-3 (VEGFR-3), which is activated by vascular endothelial growth factor-C and -D (VEGF-C and VEGF-D). These lymphangiogenic factors are commonly expressed in malignant, tumor-infiltrating and stromal cells, creating a favorable environment for generation of new lymphatic vessels. Clinical evidence demonstrates that increased lymphatic vessel density in and around tumors is associated with lymphatic metastasis and reduced patient survival. Recent evidence shows that breast cancers induce remodeling of the local lymphatic vessels and the regional lymphatic network in the sentinel and distal lymph nodes. These changes include an increase in number and diameter of tumor-draining lymphatic vessels. Consequently, lymph flow away from the tumor is increased, which significantly increases tumor cell metastasis to draining lymph nodes and may contribute to systemic spread. Collectively, recent advances in the biology of tumor-induced lymphangiogenesis suggest that chemical inhibitors of this process may be an attractive target for inhibiting tumor metastasis and cancer-related death. Nevertheless, this is a relatively new field of study and much remains to be established before the concept of tumor-induced lymphangiogenesis is accepted as a viable anti-metastatic target. This review summarizes the current concepts related to breast cancer lymphangiogenesis and lymphatic metastasis while highlighting controversies and unanswered questions.

Growth factor receptors and apoptosis regulators: signaling pathways, prognosis, chemosensitivity and treatment outcomes of breast cancer

Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

Inhibitory effect of ginsenoside Rg3 combined with gemcitabine on angiogenesis and growth of lung cancer in mice

Background

Ginsenoside Rg3, a saponin extracted from ginseng, inhibits angiogenesis. The combination of low-dose chemotherapy and anti-angiogenic inhibitors suppresses growth of experimental tumors more effectively than conventional therapy or anti-angiogenic agent alone. The present study was designed to evaluate the efficacy of low-dose gemcitabine combined with ginsenoside Rg3 on angiogenesis and growth of established Lewis lung carcinoma in mice.

Methods

C57L/6 mice implanted with Lewis lung carcinoma were randomized into the control, ginsenoside Rg3, gemcitabine and combination group. The quality of life and survival of mice were recorded. Tumor volume, inhibitive rate and necrosis rate were estimated. Necrosis of tumor and signals of blood flow as well as dynamic parameters of arterial blood flow in tumors such as peak systolic velocity (PSV) and resistive index (RI) were detected by color Doppler ultrasound. In addition, expression of vascular endothelial cell growth factor (VEGF) and CD31 were observed by immunohistochemstry, and microvessel density (MVD) of the tumor tissues was assessed by CD31 immunohistochemical analysis.

Results

Quality of life of mice in the ginsenoside Rg3 and combination group were better than in the control and gemcitabine group. Combined therapy with ginsenoside Rg3 and gemcitabine not only enhanced efficacy on suppression of tumor growth and prolongation of the survival, but also increased necrosis rate of tumor significantly. In addition, the combination treatment could obviously decrease VEGF expression and MVD as well as signals of blood flow and PSV in tumors.

Conclusion

Ginsenoside Rg3 combined with gemcitabine may significantly inhibit angiogenesis and growth of lung cancer and improve survival and quality of life of tumor-bearing mice. The combination of chemotherapy and anti-angiogenic drugs may be an innovative and promising therapeutic strategy in the experimental treatment of human lung cancer.

Apoptosis-inducing high (.)NO concentrations are not sustained either in nascent or in developed cancers

Nitric oxide ((.)NO) induces apoptosis at high concentrations by S-nitrosating proteins such as glyceraldehyde-3-phosphate dehydrogenase. This literature analysis revealed that failure to sustain high (.)NO concentrations is common to all cancers. In cervical, gastric, colorectal, breast, and lung cancer, the cause of this failure is the inadequate expression of inducible nitric oxide synthase (iNOS), resulting from the inhibition of iNOS expression by TGF-beta1 at the mRNA level. In bladder, renal, and prostate cancer, the reason for the insufficient (.)NO levels is the depletion of arginine, resulting from arginase overexpression. Arginase competes with iNOS for arginine, catalyzing its hydrolysis to ornithine and urea. In gliomas and ovarian sarcomas, low (.)NO levels are caused by inhibition of iNOS by N-chlorotaurine, produced by infiltrating neutrophils. Stimulated neutrophils express myeloperoxidase, catalyzing H2O2 oxidation of Cl- to HOCl, which N-chlorinates taurine at its concentration of 19 mM in neutrophils. In squamous cell carcinomas of the skin, ovarian cancers, lymphomas, Hodgkin's disease, and breast cancers, low (.)NO concentrations arise from the inhibition of iNOS by N-bromotaurine, produced by eosinophil-peroxidase-expressing infiltrating eosinophils. Eosinophil peroxidase catalyzes the H2O2 oxidation of Br- to HOBr, which N-brominates taurine to N-bromotaurine at its concentration of 15 mM in eosinophils. In microvascularized tumors, the (.)NO concentration is further depleted; (.)NO is rapidly consumed by red blood cells (RBCs) through S-nitrosation of RBC glutathione and hemoglobin, and by oxidation to nitrate by RBC oxyhemoglobin. Angiogenesis-inhibiting antibodies are currently used to treat cancers; their mode of action is not, as previously thought, reduction of the tumor O2 or nutrient supply. They actually decrease the loss of (.)NO to RBCs.

Intricacies of bevacizumab-induced toxicities and their management

OBJECTIVE

To review the serious and common toxicities of bevacizumab and describe their incidence, risk factors, presentation, pathophysiology, and management.

DATA SOURCES

Literature for this review article was collected from PubMed, MEDLINE, and the proceedings of the American Society of Clinical Oncology (2000-November 2008). The key terms used in the search were: bevacizumab, vascular endothelial growth factor, angiogenesis inhibitors, toxicity, toxicity management, and adverse event.

STUDY SELECTION AND DATA EXTRACTION

Review articles, preclinical studies, and all published Phase 1-3 clinical trials were reviewed. The references listed in identified articles were examined for additional publications.

DATA SYNTHESIS

The biomedical literature from 2000 to 2008 confirms that bevacizumab carries serious and potentially life-threatening toxicity risks and emphasizes the importance of early recognition, continuous monitoring, and prompt management of these toxicities. Such toxicities include hemorrhage/bleeding, wound healing complications, gastrointestinal perforation, arterial thromboembolism, congestive heart failure, hypertension, proteinuria/nephrotic syndrome, infusion-related hypersensitivity reactions, and reversible posterior leukoencephalopathy syndrome. Patients at the highest risk for these toxicities are individuals with a history of hypertension, thromboembolism, bleeding, cardiovascular disease, or preexisting proteinuria, as these conditions may be exacerbated by bevacizumab use. Additionally, particular tumor types correlate with risk for individual toxicities; for example, patients with squamous non-small-cell lung cancer or rectal cancer have a higher risk of bleeding, those with renal cell carcinoma have a higher proteinuria risk, and patients with colorectal cancer have a higher risk of gastrointestinal perforation. Further investigation is warranted to develop effective management strategies for these toxicities.

CONCLUSIONS

As bevacizumab is becoming widely used in general oncology practice, it is important to understand the toxicities that can arise and to develop practice guidelines for their management.

Study on relationship between angiogenesis and micrometastases of peripheral blood in breast cancer

PURPOSE

To investigate the relationship between microvessel density, expression of vascular endothelial growth factor A (VEGF-A) and micrometastases in peripheral blood of patients with breast cancer.

METHOD

Microvessel density (MVD) and expression of VEGF-A were detected by immunohistochemistry S-P. Nested RT-PCR was introduced to detect the expression of hMAM mRNA in peripheral blood of all cases.

RESULT

Average MVD was 28.95 +/- 6.95 microvessels/100x and positive rate of VEGF-A was 64.0% (32/50) in 50 cases with breast cancer. MVD count and expression of VEGF-A were related to tumor size, metastasis of axillary lymph nodes and clinical stages (P < 0.05), independent of age and histological classification (P > 0.05). The positive rate of hMAM mRNA in peripheral blood was 34.0% (17/50), which correlated with lymphatic metastasis and clinical stages (P < 0.05), independent of pathological category, menopause and hormone receptor (P > 0.05). MVD count and positive rate of VEGF-A in breast cancer with positive expression of hMAM mRNA was obviously higher than those without hMAM mRNA expression (chi (2) = 5.766, P = 0.032; t = 5.37, P = 0.002).

CONCLUSIONS

MVD count and positive expression of VEGF-A closely correlated to hMAM mRNA released from tumor cells in the circulation. hMAM mRNA is expected to become a valuable marker for further study on micrometastases of breast cancer.

Role of prolactin and vasoinhibins in the regulation of vascular function in mammary gland

The formation of new blood vessels has become a major focus of mammary gland research stimulated by the therapeutic opportunities of controlling angiogenesis in breast cancer. Normal growth and involution of the mammary gland are profoundly affected by the expansion and regression of blood vessels, whereas dysregulation of angiogenesis is characteristic of breast cancer growth and metastasis. Prolactin stimulates the growth and differentiation of the mammary gland under normal conditions, but its role in breast cancer is controversial. Its action is complicated by the fact that prolactin itself is angiogenic, but proteases cleave prolactin to generate vasoinhibins, a family of peptides that act on endothelial cells to suppress angiogenesis and vasodilation and to promote apoptosis-mediated vascular regression. This review summarizes our current knowledge about the vascular effects of prolactin and the generation and action of vasoinhibins, and discusses their possible contribution to the regulation of blood vessels in the normal and malignant mammary gland.