https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

The establishment of a vascular supply is required for organ development and differentiation as well as for tissue repair and reproductive functions in the adult1 Neovascularization (angiogenesis) is also implicated in the pathogenesis of a number of disorders These include: proliferative retinopathies, age-related macular degeneration, tumors, rheumatoid arthritis, and psoriasis1,2 A strong correlation has been noted between density of microvessels in primary breast cancers and their nodal metastases and patient survival3 Similarly, a correlation has been reported between vascularity and invasive behavior in several other tumors4–6

The biology of vascular endothelial growth factor

Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. The first tetracycline-resistant bacterium, Shigella dysenteriae, was isolated in 1953. Tetracycline resistance now occurs in an increasing number of pathogenic, opportunistic, and commensal bacteria. The presence of tetracycline-resistant pathogens limits the use of these agents in treatment of disease. Tetracycline resistance is often due to the acquisition of new genes, which code for energy-dependent efflux of tetracyclines or for a protein that protects bacterial ribosomes from the action of tetracyclines. Many of these genes are associated with mobile plasmids or transposons and can be distinguished from each other using molecular methods including DNA-DNA hybridization with oligonucleotide probes and DNA sequencing. A limited number of bacteria acquire resistance by mutations, which alter the permeability of the outer membrane porins and/or lipopolysaccharides in the outer membrane, change the regulation of innate efflux systems, or alter the 16S rRNA. New tetracycline derivatives are being examined, although their role in treatment is not clear. Changing the use of tetracyclines in human and animal health as well as in food production is needed if we are to continue to use this class of broad-spectrum antimicrobials through the present century.

Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen in vitro and an angiogenic inducer in a variety of in vivo models. Hypoxia has been shown to be a major inducer of VEGF gene transcription. The tyrosine kinases Flt-1 (VEGFR-1) and Flk-1/KDR (VEGFR-2) are high-affinity VEGF receptors. The role of VEGF in developmental angiogenesis is emphasized by the finding that loss of a single VEGF allele results in defective vascularization and early embryonic lethality. VEGF is critical also for reproductive and bone angiogenesis. Substantial evidence also implicates VEGF as a mediator of pathological angiogenesis. In situ hybridization studies demonstrate expression of VEGF mRNA in the majority of human tumors. Anti-VEGF monoclonal antibodies and other VEGF inhibitors block the growth of several tumor cell lines in nude mice. Clinical trials with various VEGF inhibitors in a variety of malignancies are ongoing. Very recently, an anti-VEGF monoclonal antibody (bevacizumab; Avastin) has been approved by the Food and Drug Administration as a first-line treatment for metastatic colorectal cancer in combination with chemotherapy. Furthermore, VEGF is implicated in intraocular neovascularization associated with diabetic retinopathy and age-related macular degeneration.

/pdf/vascular-endothelial-growth-factor-basic-science-and-17gyy6h97s.pdf

Vascular endothelial growth factor: basic science and clinical progress.

In studying the evolution of organic chemistry and grasping its essence, one comes quickly to the conclusion that no other type of reaction plays as large a role in shaping this domain of science than carbon-carbon bond-forming reactions. The Grignard, Diels-Alder, and Wittig reactions are but three prominent examples of such processes, and are among those which have undeniably exercised decisive roles in the last century in the emergence of chemical synthesis as we know it today. In the last quarter of the 20th century, a new family of carbon-carbon bond-forming reactions based on transition-metal catalysts evolved as powerful tools in synthesis. Among them, the palladium-catalyzed cross-coupling reactions are the most prominent. In this Review, highlights of a number of selected syntheses are discussed. The examples chosen demonstrate the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.

Palladium-catalyzed cross-coupling reactions in total synthesis.

Vascular endothelial growth factor (VEGF) has been investigated as a potent mediator of brain tumor angiogenesis, vascular permeability, and glioma growth. Using a VEGF ELISA, we determined the concentration of VEGF in the sera and tumor extracts of 19 brain tumor patients including glioblastoma, anaplastic astrocytoma, low grade astrocytoma, meningioma, malignant lymphoma, and metastatic brain tumor as well as normal brain. Although VEGF concentration of the serum was not correlated with that of the tissue, VEGF concentrations of glioblastoma cyst fluid were 200-300-fold higher than those of serum in the patients. VEGF concentration in the tumors was significantly correlated with the vascularity measured by counting vessels stained with von Willebrand factor antibody. VEGF protein localized to the cytoplasm of tumor cells and vasculature in gliomas, predominantly in the peripheral microvessel "hot spots" as well as around the necrosis in glioblastomas. VEGF immunopositivities were well reflected with VEGF concentration determined by ELISA. VEGF ELISA demonstrated time-dependent increase of the VEGF concentration in the serum-free conditioned medium of various glioma cell lines. The conditioned medium with high VEGF concentration induced endothelial cell migration. These observations suggest that VEGF represents a useful marker and measurable element of glioblastoma angiogenesis. The measurement of VEGF concentration by ELISA in tumor and tumor cyst fluid may allow for the assessment of vascularity in gliomas.

https://cancerres.aacrjournals.org/content/canres/56/9/2185.full.pdf

Concentration of Vascular Endothelial Growth Factor in the Serum and Tumor Tissue of Brain Tumor Patients

We elucidated the relationship between vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), which is a potent angiogenic factor, and the growth of primary and metastatic tumors using an immunoneutralizing monoclonal antibody against human VEGF/VPF 121 . The monoclonal antibody, MV303, suppressed the growth of human umbilical vein endothelial cells (HUVEC) induced by VEGF/VPF 121 or VEGF/VPF 165 but did not inhibit its growth induced by basic fibroblast growth factor. MV303 inhibited the binding of 125 I-VEGF/VPF 121 to HUVEC. We examined the effects of MV303 on tumor angiogenesis using a membrane chamber packed with the human fibrosarcoma cell line HT-1080 and implanted s.c. into BALB/c mice. The neovascularization induced by HT-1080 was inhibited by the i.v. injection of MV303 at a dose of 100 µg/mouse. Furthermore, the growth of solid tumors of s.c. implanted HT-1080 in BALB/c nude mice was almost completely inhibited by the i.v. and s.c. administration of MV303 ten times from day 1 at a dose of 100 µg/mouse (T/C values of tumor volume at day 18 were 0.20 and 0.18, respectively). Tumor growth was suppressed when MV303 was administered, even from eight days after tumor inoculation. MV303 suppressed the increase in lung weight caused by experimental metastasis with i.v. inoculation of cultured HT-1080 cells to BALB/c nude mice. The life spans of the mice treated with MV303 were significantly prolonged. These results indicated that VEGF/VPF played an important role in both primary and metastatic tumor growth as a tumor angiogenesis factor. MV303, an immunoneutralizing monoclonal antibody against VEGF/VPF, potently inhibited both primary and metastatic tumor growth with no marked side effects.

https://cancerres.aacrjournals.org/content/canres/55/22/5296.full.pdf

Inhibition of Tumor Growth and Metastasis by an Immunoneutralizing Monoclonal Antibody to Human Vascular Endothelial Growth Factor/Vascular Permeability Factor121

https://www.jstage.jst.go.jp/article/antibiotics1968/22/6/22_6_283/_pdf

Leupeptins, new protease inhibitors from Actinomycetes.

Vascular endothelial growth factor (VEGF) is known to play crucial roles in tumor angiogenesis. We have investigated the circulating level of VEGF in sera from cancer patients as well as from healthy normal controls using a sensitive enzymatic immunoassay. Immunoreactive VEGF proteins were detectable in normal sera, and the cutoff level was determined to be 180 pg/ml. In examined patients with all types of cancer, including breast, gastrointestinal, hepatobiliary, and lung cancer, an aberrant increase in the circulating level of VEGF was detected. For example, in 137 primary breast cancer patients, 12 (8.8%) showed an aberrant increase in VEGF levels. This aberrant expression of VEGF in sera was significantly associated with the progression of the disease, and with VEGF protein expression in tumor tissues. In addition, a Western blot analysis confirmed the presence of the VEGF165 form in sera from a patient with recurrent breast cancer. It was concluded that VEGF was detectable in normal sera, and its level was increased in some populations of cancer patients. A positive angiogenesis regulator, VEGF might function as an endocrine growth factor, particularly for solid tumors.

/pdf/concentrations-of-vascular-endothelial-growth-factor-in-the-2zlakn7y0f.pdf

Concentrations of vascular endothelial growth factor in the sera of normal controls and cancer patients.

BACKGROUND

Recent clinical studies have demonstrated that tumor angiogenesis is a potent prognostic indicator for breast cancer patients. The quantitation of endothelial growth factors is thought to be useful to assess angiogenic phenotype in the tumor. Among the many new endothelial growth factors, vascular endothelial growth factor (VEGF) is known to be particularly responsible for promoting the neovascularization in human breast cancer.



METHODS

Intratumoral protein levels of VEGF were measured by enzymatic immunoassay in 135 primary breast cancer tissues. The VEGF levels were compared with the microvessel density evaluated by immunostaining the endothelial antigen and also were compared with intratumoral protein levels of other endothelial growth factors, including basic fibroblast growth factor (bFGF) and hepatocyte growth factor (HGF).



RESULTS

Intratumoral VEGF concentrations varied from 3.3 pg/mg protein to 2032 pg/mg protein (average 148 pg/mg protein). An immunocytochemical analysis using anti-VEGF antibody confirmed that VEGF was located mainly in the cytoplasm of the tumor cells. The VEGF concentrations were significantly higher in vascularly rich tumors than in vascularly poor tumors. No significant association was found between VEGF concentrations and the two other endothelial growth factor concentrations.



CONCLUSIONS

The quantitation of intratumoral VEGF levels seems to be useful for assessing the activity of tumor angiogenesis. Cancer 1996;77:1101-6.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/%28SICI%291097-0142%2819960315%2977%3A6%3C1101%3A%3AAID-CNCR15%3E3.0.CO%3B2-5

Shinichi Kondo

Papers

Concentration of Vascular Endothelial Growth Factor in the Serum and Tumor Tissue of Brain Tumor Patients

Inhibition of Tumor Growth and Metastasis by an Immunoneutralizing Monoclonal Antibody to Human Vascular Endothelial Growth Factor/Vascular Permeability Factor121

Leupeptins, new protease inhibitors from Actinomycetes.

Concentrations of vascular endothelial growth factor in the sera of normal controls and cancer patients.

Quantitative analysis of vascular endothelial growth factor in primary breast cancer.