Targeting the Ang2/Tie2 Axis with Tanshinone IIA Elicits Vascular Normalization in Ischemic Injury and Colon Cancer.

Pathological angiogenesis, as exhibited by aberrant vascular structure and function, has been well deemed to be a hallmark of cancer and various ischemic diseases. Therefore, strategies to normalize vasculature are of potential therapeutic interest in these diseases. Recently, identifying bioactive compounds from medicinal plant extracts to reverse abnormal vasculature has been gaining increasing attention. Tanshinone IIA (Tan IIA), an active component of Salvia miltiorrhiza, has been shown to play significant roles in improving blood circulation and delaying tumor progression. However, the underlying mechanisms responsible for the therapeutic effects of Tan IIA are not fully understood. Herein, we established animal models of HT-29 human colon cancer xenograft and hind limb ischemia to investigate the role of Tan IIA in regulating abnormal vasculature. Interestingly, our results demonstrated that Tan IIA could significantly promote the blood flow, alleviate the hypoxia, improve the muscle quality, and ameliorate the pathological damage after ischemic insult. Meanwhile, we also revealed that Tan IIA promoted the integrity of vascular structure, reduced vascular leakage, and attenuated the hypoxia in HT-29 tumors. Moreover, the circulating angiopoietin 2 (Ang2), which is extremely high in these two pathological states, was substantially depleted in the presence of Tan IIA. Also, the activation of Tie2 was potentiated by Tan IIA, resulting in decreased vascular permeability and elevated vascular integrity. Mechanistically, we uncovered that Tan IIA maintained vascular stability by targeting the Ang2-Tie2-AKT-MLCK cascade. Collectively, our data suggest that Tan IIA normalizes vessels in tumors and ischemic injury via regulating the Ang2/Tie2 signaling pathway.

Cyclovirobuxine D inhibits colorectal cancer tumorigenesis via the CTHRC1­AKT/ERK­Snail signaling pathway.

Cyclovirobuxine D (CVB­D) is an alkaloid, which is mainly derived from Buxus microphylla. It has been reported that CVB­D has positive effects on breast cancer, gastric cancer and other malignant tumors. However, to the best of our knowledge, there are no reports regarding the effects of CVB­D on colorectal cancer (CRC). The purpose of the present study was to determine the anticancer effects of CVB­D and further elucidate its molecular mechanism(s). DLD­1 and LoVo cell lines were selected to evaluate the antitumor effect of CVB­D. Cytotoxicity, viability and proliferation were evaluated by the MTT and colony formation assays. Flow cytometry was used to detect the effects on apoptosis and the cell cycle in CVB­D­treated CRC cells. The migration and invasion abilities of CRC cells were examined by wound healing and Transwell assays. In addition, RNA sequencing, bioinformatics analysis and western blotting were performed to investigate the target of drug action and clarify the molecular mechanisms. A xenograft model was established using nude mice, and ultrasound was employed to assess the preclinical therapeutic effects of CVB­D in vivo. It was identified that CVB­D inhibited the proliferation, migration, stemness, angiogenesis and epithelial­mesenchymal transition of CRC cells, and induced apoptosis and S­phase arrest. In addition, CVB­D significantly inhibited the growth of xenografts. It is notable that CVB­D exerted anticancer effects in CRC cells partly by targeting collagen triple helix repeat containing 1 (CTHRC1), which may be upstream of the AKT and ERK pathways. CVB­D exerted anticancer effects through the CTHRC1­AKT/ERK­Snail signaling pathway. Targeted therapy combining CTHRC1 with CVB­D may offer a promising novel therapeutic approach for CRC treatment.

Stroma-normalised vessel density predicts benefit from adjuvant fluorouracil-based chemotherapy in patients with stage II/III colon cancer.

BACKGROUND: Identification of biomarkers associated with benefit of adjuvant chemotherapy in stage II/III colon cancer is an important task. METHODS: Vessel density (VD) and tumour stroma were analysed in a randomised-trial-derived discovery cohort (n = 312) and in a stage II/III group of a population-based validation cohort (n = 85). VD was scored separately in the tumour centre, invasive margin and peritumoral stroma compartments and quantitated as VD/total analysed tissue area or VD/stroma area. RESULTS: High stroma-normalised VD in the invasive margin was associated with significantly longer time to recurrence and overall survival (OS) (p = 0.002 and p = 0.006, respectively) in adjuvant-treated patients of the discovery cohort, but not in surgery-only patients. Stroma-normalised VD in the invasive margin and treatment effect were significantly associated according to a formal interaction test (p = 0.009). Similarly, in the validation cohort, high stroma-normalised VD was associated with OS in adjuvant-treated patients, although statistical significance was not reached (p = 0.051). CONCLUSION: Through the use of novel digitally scored vessel-density-related metrics, this exploratory study identifies stroma-normalised VD in the invasive margin as a candidate marker for benefit of adjuvant 5-FU-based chemotherapy in stage II/III colon cancer. The findings, indicating particular importance of vessels in the invasive margin, also suggest biological mechanisms for further exploration.

Lathyrus sativus diamine oxidase counteracts histamine-induced cell proliferation, migration and pro-angiogenic mediators release in human colon adenocarcinoma cell line Caco-2.

Because histamine is a modulator of cancer cell proliferation and invasiveness, this study aimed at investigating the effect of Lathyrus sativus-derived diamine oxidase (LSAO) and its mechanism of action on Caco-2 cell line, considering that LSAO catalizes the oxidative deamination of histamine to the corresponding aldehyde, NH3 and H2 O2 . Histamine (0.01-1 µM) caused a proliferative effect on Caco-2 cells promoting cell migration, invasion and nitric oxide and vascular endothelial growth factor release. Histamine (1 µM) stimulus also down regulated occludin expression, favouring up regulation of pro-proliferative nuclear protein Ki67. Incubation with LSAO (0.004-0.4 µM) resulted in a significant inhibition of histamine-induced effects. LSAO rescued occludin expression and down regulated Ki67, and it inhibited histamine-induced increase of both MMP-2 and 9 expression. Histamine effects were mediated by RhoA-GTP down regulation and inversely related to phospho-p38MAPK/p50/65 up regulation. These effects were counteracted by LSAO incubation. Histamine catabolism by LSAO accounts for a significant down regulation of proliferation and invasiveness of Caco-2 cells. This study highlights the importance to control histamine levels in contrasting pro-angiogenic and metastatization capability of colon cancer cells and expands the knowledge about the diamine oxidase from L. sativus seeding as a phytotherapeutic approach for colon cancer.

Imperatorin suppresses proliferation and angiogenesis of human colon cancer cell by targeting HIF-1α via the mTOR/p70S6K/4E-BP1 and MAPK pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Angelica dahurica is a commonly used traditional Chinese medicine to treat migraine headache, toothache and cancer. Imperatorin is an active natural furocoumarin component originating from Angelica dahurica and has been shown to exhibit multiple bioeffector functions, including anti-cancer activity. However, the mechanism by which imperatorin inhibits tumor growth is not fully understood. AIM OF THE STUDY: The aim of this study was to investigate the effectiveness of imperatorin as a treatment of cancer and to identify the underlying mechanisms of its anticancer activity. MATERIALS AND METHODS: HCT116, HeLa, and Hep3B cells were used in this study. Major assays were promoter-reporter gene assay, MTT, western blot analysis, immunofluorescence assay, reverse transcription-PCR (RT-PCR), flow cytometric analysis, clonogenic assay, EdU labeling and immunofluorescence, xenografted assay, and VEGF ELISA. RESULTS: We here demonstrated the effect of imperatorin on hypoxia-inducible factor-1 (HIF-1) activation. Imperatorin showed a potent inhibitory activity against HIF-1 activation induced by hypoxia in various human cancer cell lines. This compound markedly decreased the hypoxia-induced accumulation of HIF-1α protein dose-dependently, whereas it did not affect the expressions of HIF-1ß and topoisomerase-I (Topo-I). Further analysis revealed that imperatorin inhibited HIF-1α protein synthesis, without affecting the expression level of HIF-1α mRNA or degradation of HIF-1α protein. Moreover, the phosphorylation levels of mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase (p70S6K), eIF4E binding protein-1 (4E-BP1), eukaryotic initiation factor 4E (eIF4E), extracellular signal-regulated kinase-1/2 (ERK1/2), SAPK/JNK and p38 were significantly suppressed by imperatorin. Furthermore, imperatorin prevented hypoxia-induced expression of HIF-1 target genes and flow cytometric analysis indicated that imperatorin induced G1 phase arrest in human colon cancer cell (HCT116). We found that imperatorin administration inhibits tumor growth and blocks tumor angiogenesis in a xenograft tumor model. CONCLUSIONS: These results show that imperatorin inhibited HIF-1α protein synthesis by downregulating the mTOR/p70S6K/4E-BP1 and MAPK pathways. These conclusions suggest that imperatorin is an effective inhibitor of HIF-1 and provide new perspectives into the mechanism of its anticancer activity.

Tumor-derived hydrogen sulfide, produced by cystathionine-ß-synthase, stimulates bioenergetics, cell proliferation, and angiogenesis in colon cancer.

The physiological functions of hydrogen sulfide (H2S) include vasorelaxation, stimulation of cellular bioenergetics, and promotion of angiogenesis. Analysis of human colon cancer biopsies and patient-matched normal margin mucosa revealed the selective up-regulation of the H2S-producing enzyme cystathionine-ß-synthase (CBS) in colon cancer, resulting in an increased rate of H2S production. Similarly, colon cancer-derived epithelial cell lines (HCT116, HT-29, LoVo) exhibited selective CBS up-regulation and increased H2S production, compared with the nonmalignant colonic mucosa cells, NCM356. CBS localized to the cytosol, as well as the mitochondrial outer membrane. ShRNA-mediated silencing of CBS or its pharmacological inhibition with aminooxyacetic acid reduced HCT116 cell proliferation, migration, and invasion; reduced endothelial cell migration in tumor/endothelial cell cocultures; and suppressed mitochondrial function (oxygen consumption, ATP turnover, and respiratory reserve capacity), as well as glycolysis. Treatment of nude mice with aminooxyacetic acid attenuated the growth of patient-derived colon cancer xenografts and reduced tumor blood flow. Similarly, CBS silencing of the tumor cells decreased xenograft growth and suppressed neovessel density, suggesting a role for endogenous H2S in tumor angiogenesis. In contrast to CBS, silencing of cystathionine-γ-lyase (the expression of which was unchanged in colon cancer) did not affect tumor growth or bioenergetics. In conclusion, H2S produced from CBS serves to (i) maintain colon cancer cellular bioenergetics, thereby supporting tumor growth and proliferation, and (ii) promote angiogenesis and vasorelaxation, consequently providing the tumor with blood and nutritients. The current findings identify CBS-derived H2S as a tumor growth factor and anticancer drug target.

Inhibition of angiogenesis: a novel antitumor mechanism of the herbal compound arctigenin.

Arctigenin, a functional ingredient of several traditional Chinese herbs, has been reported to have potential antitumor activity. However, its mechanisms of action are still not well elucidated. Because the establishment and metastatic spread of tumors is crucially dependent on angiogenesis, here we investigated whether arctigenin inhibits tumor growth by disturbing blood vessel formation. For this purpose, human dermal microvascular endothelial cells were exposed to different arctigenin doses to study their viability, proliferation, protein expression, migration, and tube formation compared with vehicle-treated controls. In addition, arctigenin action on vascular sprouting was analyzed in an aortic ring assay. Furthermore, we studied direct arctigenin effects on CT26.WT colon carcinoma cells. Spheroids of these tumor cells were transplanted into the dorsal skinfold chamber of arctigenin-treated and vehicle-treated BALB/c mice for the in-vivo analysis of tumor vascularization and growth by intravital fluorescence microscopy, histology, and immunohistochemistry. We found that noncytotoxic doses of arctigenin dose dependently reduced the proliferation of human dermal microvascular endothelial cells without affecting their migratory and tube-forming capacity. Arctigenin treatment also resulted in a decreased cellular expression of phosphorylated serine/threonine protein kinase AKT, vascular endothelial growth factor receptor 2, and proliferating cell nuclear antigen and inhibited vascular sprouting from aortic rings. In addition, proliferation, but not secretion of vascular endothelial growth factor, was decreased in arctigenin-treated tumor cells. Finally, arctigenin suppressed the vascularization and growth of engrafting CT26.WT tumors in the dorsal skinfold chamber model. Taken together, these results show for the first time an antiangiogenic action of arctigenin, which may contribute considerably toward its antitumor activity.

Novel anti-angiogenic effects of formononetin in human colon cancer cells and tumor xenograft.

Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus, a medicinal plant that possesses antitumorigenic properties. Our previous findings demonstrated that formononetin initiates growth-inhibitory and pro-apoptotic activities in human colon cancer cells. In the present study, we aimed to further examine the potential of formononetin in controlling angiogenesis and tumor cell invasiveness in human colon cancer cells and tumor xenografts. The results showed that formononetin downregulated the expression of the key pro-angiogenic factors, including vascular endothelial growth factor (VEGF) and matrix metalloproteinases. We also discovered that the invasiveness of metastatic colon cancer cells was alleviated following drug treatment. The potential anti-angiogenic effect of formononetin was examined in nude mouse xenografts. The tumor size and the number of proliferating cells were reduced in the tumor tissues obtained from the formononetin-treated group. The serum VEGF level was also reduced in the drug-treated animals when compared to the controls. These findings suggest that formononetin inhibits angiogenesis and tumor cell invasion, and thus support its use in the treatment of advanced and metastatic colon cancers.

Grape seed proanthocyanidins inhibit colon cancer-induced angiogenesis through suppressing the expression of VEGF and Ang1.

Tumor cells trigger angiogenesis through overexpression of various angiogenic factors including vascular endothelial growth factor (VEGF) and angiopoietin 1 (Ang1). Therefore, inhibition of the expression of both VEGF and Ang1, the initial step of tumor angiogenesis, is a promising strategy for cancer chemoprevention and therapy. Grape seed proanthocyanidins (GSPs) are widely consumed dietary supplements that have antitumor activity. Due to their polymeric structure, GSPs are poorly absorbed along the gastrointestinal tract and can reach the colon at high concentrations, allowing these chemicals to act as chemopreventive agents for colon cancer. In the present study, we found that GSPs inhibited colon tumor-induced angiogenesis and, thus, the growth of colon tumor xenografts on the chick chorioallantoic membranes. The mechanisms of their action were related to inhibiting the expression of both VEGF and Ang1 through scavenging reactive oxygen species. Previous studies have demonstrated that the chemopreventive effects of GSPs on colon cancer are associated with their growth inhibitory and apoptosis-inducing effects. Our results demonstrate another mechanism by which GSPs inhibit colon tumor growth, which will be helpful for developing GSPs as a pharmacologically safe angiopreventive agent against colorectal cancer.

Global and local hard X-ray tomography of a centimeter-size tumor vessel tree.

The visualization of the vascular network in tumors down to the smallest vessels requires high spatial resolution and reasonable contrast. Stained corrosion casts of the microvasculature network guarantee superior X-ray absorption contrast and highest reproduction fidelity. Tomography of a centimeter-size tumor, however, is unfeasible at the spatial resolution needed to reveal the smallest vessels. Therefore, local tomography has been performed to visualize the smallest capillaries within the region of interest. These three-dimensional data show the detailed morphology, but the reconstructed absorption coefficients obtained in local tomography differ substantially from the absorption coefficients retrieved from the less detailed global tomography data. This paper deals with the adaptation of local tomography data using the global data and considers two-parameter histogram matching of the radiographs, sinogram extension, and multi-parameter cupping correction. It is demonstrated that two-parameter histogram matching of the radiographs already provides reasonable agreement. The change of the lens in front of the detector's camera, however, significantly affects the obtained local X-ray absorption coefficients in the tomograms predominantly owing to the dissimilar point-spread functions of the two configurations used, and much less to the fact that one of the data sets was acquired in a local geometry.

Cat's whiskers tea (Orthosiphon stamineus) extract inhibits growth of colon tumor in nude mice and angiogenesis in endothelial cells via suppressing VEGFR phosphorylation.

Cat's whiskers (Orthosiphon stamineus) is commonly used as Java tea to treat kidney stones including a variety of angiogenesis-dependent diseases such as tumorous edema, rheumatism, diabetic blindness, and obesity. In the present study, antitumor potential of standardized 50% ethanol extract of O. stamineus leaves (EOS) was evaluated against colorectal tumor in athymic mice and antiangiogenic efficacy of EOS was investigated in human umbilical vein endothelial cells (HUVEC). EOS at 100 mg/kg caused 47.62 ± 6.4% suppression in tumor growth, while at 200 mg/kg it caused 83.39 ± 4.1% tumor regression. Tumor histology revealed significant reduction in extent of vascularization. Enzyme-linked immunosorbent assay showed EOS (200 mg/kg) significantly reduced the vascular endothelial growth factor (VEGF) level in vitro (211 ± 0.26 pg/ml cell lysate) as well as in vivo (90.9 ± 2 pg/g tissue homogenate) when compared to the control (378 ± 5 and 135.5 ± 4 pg, respectively). However, EOS was found to be noncytotoxic to colon cancer and endothelial cells. In vitro, EOS significantly inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). EOS suppressed VEGF-induced phosphorylation of VEGF receptor-2 in HUVECs. High performance liquid chromatography (HPLC) analysis of EOS showed high rosmarinic acid contents, whereas phytochemical analysis revealed high protein and phenolic contents. These results demonstrated that the antitumor activity of EOS may be due to its VEGF-targeted antiangiogenicity.

Deltonin, a steroidal saponin, inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis and antiangiogenesis.

Deltonin, a steroidal saponin, isolated from Dioscorea zingiberensis Wright (DZW), has shown high-cytotoxic activity in cancer cells. However, its mechanisms and in vivo anti-cancer effects remain unknown. In the present study, we evaluated the effects and explored the anti-tumor mechanisms of deltonin on a panel of colon cancer cell lines and in a mouse model of murine colon cancer C26. Deltonin had more cytotoxic effect on C26 cells than 5-fluorouracil had, promoting dramatic G2-M phase arrest and apoptosis in C26 cells in a concentration-dependent manner; oral administration of deltonin significantly inhibited the tumor growth and prolonged survival of the tumor bearing mice. The deltonin treatment caused a noticeable apoptosis in tumor tissue, which associated with increased levels of Bax, activated caspase-3, caspase-9, and cleaved poly (ADPribose) polymerase, decreased pro-caspase-8, pro-caspase-9, Bcl-2 expression levels and extracellular signal-regulated kinase-1/2 activity; and dose-dependently inhibit angiogenesis. In conclusion, the findings in this study demonstrated that deltonin is an effective natural agent for cancer therapy, which may be mediated, in part, by induction of apoptosis, as well as involve mitogen-activated protein kinase pathways, and inhibition of angiogenesis.

Mild elevation of body temperature reduces tumor interstitial fluid pressure and hypoxia and enhances efficacy of radiotherapy in murine tumor models.

Human and rodent solid tumors often exhibit elevated interstitial fluid pressure (IFP). This condition is recognized as a prognostic indicator for reduced responses to therapy and decreased disease-free survival rate. In the present study, we tested whether induction of a thermoregulatory-mediated increase in tissue blood flow, induced by exposure of mice to mild environmental heat stress, could influence IFP and other vascular parameters within tumors. Using several murine tumor models, we found that heating results in a sustained reduction in tumor IFP correlating with increased tumor vascular perfusion (measured by fluorescent imaging of perfused vessels, laser Doppler flowmetry, and MRI) as well as a sustained reduction in tumor hypoxia. Furthermore, when radiation therapy was administered 24 hours postheating, we observed a significant improvement in efficacy that may be a result of the sustained reduction in tumor hypoxia. These data suggest, for the first time, that environmental manipulation of normal vasomotor function is capable of achieving therapeutically beneficial changes in IFP and microvascular function in the tumor microenvironment.

Inhibition of metastasis, angiogenesis, and tumor growth by Chinese herbal cocktail Tien-Hsien Liquid.

BACKGROUND: Advanced cancer is a multifactorial disease that demands treatments targeting multiple cellular pathways. Chinese herbal cocktail which contains various phytochemicals may target multiple dys-regulated pathways in cancer cells and thus may provide an alternative/complementary way to treat cancers. Previously we reported that the Chinese herbal cocktail Tien-Hsien Liguid (THL) can specifically induce apoptosis in various cancer cells and have immuno-modulating activity. In this study, we further evaluated the anti-metastatic, anti-angiogenic and anti-tumor activities of THL with a series of in vitro and in vivo experiments. METHODS: The migration and invasion of cancer cells and endothelial cells was determined by Boyden chamber transwell assays. The effect of THL on pulmonary metastasis was done by injecting CT-26 colon cancer cells intravenously to syngenic mice. The in vitro and in vivo microvessel formation was determined by the tube formation assay and the Matrigel plug assay, respectively. The in vivo anti-tumor effect of THL was determined by a human MDA-MB-231 breast cancer xenograft model. The expression of metalloproteinase (MMP)-2, MMP-9, and urokinase plasminogen activator (uPA) was measured by gelatin zymography. The expression of HIF-1alpha and the phosphorylation of ERK1/2 were determined by Western blot. RESULTS: THL inhibited the migration and invasion ability of various cancer cells in vitro, decreased the secretion of MMP-2, MMP-9, and uPA and the activity of ERK1/2 in cancer cells, and suppressed pulmonary metastasis of CT-26 cancer cells in syngenic mice. Moreover, THL inhibited the migration, invasion, and tube formation of endothelial cells in vitro, decreased the secretion of MMP-2 and uPA in endothelial cells, and suppressed neovascularization in Matrigel plugs in mice. Besides its inhibitory effect on endothelial cells, THL inhibited hypoxia-induced HIF-1alpha and vascular endothelial growth factor-A expression in cancer cells. Finally, our results show that THL inhibited the growth of human MDA-MB-231 breast cancer xenografts in NOD-SCID mice. This suppression of tumor growth was associated with decreased microvessel formation and increased apoptosis caused by THL. CONCLUSION: Our data demonstrate that THL had broad-spectra anti-cancer activities and merits further evaluation for its use in cancer therapy.

Vascular endothelial growth factor gene polymorphisms in patients with colorectal cancer.

BACKGROUND: Angiogenesis plays an important role in tumor progression. The vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis. In the present study we evaluated single nucleotide polymorphisms (SNPs) -2578C > A, -1154G > A, and +936C > T in the VEGF gene, and their prognostic value for patients operated on for colorectal cancer (CRC). PATIENTS AND METHOD: VEGF polymorphisms have been analyzed in 177 patients who had undergone surgical resection at Hospital Clínico San Carlos. The analysis of these polymorphisms was performed with specific probes for each nucleotide in a multiplex reaction using real-time PCR. RESULTS: We only found a statistically significant relationship for one of these three polymorphisms, +936C > T, with gender and tumor location; 10.7% of patients heterozygotes for this SNP had tumors located in proximal colon, 35.2% in distal segment and 54.1% in rectum (p = 0.03). Patients with the +936T/T genotype had 100% overall survival (OS). CONCLUSION: Patients with a +936T/T genotype showed increased survival, therefore the +936C > T SNP could be a useful marker in the follow-up and clinical management of patients with colorectal cancer.

Interobserver variation in the reporting of local peritoneal involvement and extramural venous invasion in colonic cancer.

AIMS: Local peritoneal involvement (LPI) and extramural venous invasion (EMVI) are of prognostic value in Dukes' B colonic cancers and may be used to select patients for adjuvant chemotherapy. There is marked variation in the frequency with which they are reported however, ranging from 7% to 39% and 10% to 90%, respectively. A grading system for diagnosing LPI has been proposed by Shepherd et al. and partially incorporated into the Royal College of Pathologists guidelines for reporting colorectal cancer. This study aimed to determine the degree of interobserver variation in the reporting of LPI and EMVI amongst a group of experienced pathologists with a special interest in gastrointestinal pathology. METHODS AND RESULTS: Four pathologists specialising in gastrointestinal pathology independently assessed LPI according to the grading system described by Shepherd et al. and the presence or absence of EMVI on 138 and 131 slides of pT3 and pT4 colonic cancers, respectively. Kappa statistics were performed to assess interobserver agreement. Kappa values for LPI ranged from kappa = 0.74 (substantial agreement) to kappa = 0.89 (almost perfect agreement). Kappa values for EMVI ranged from kappa = 0.29 (poor agreement) to kappa = 0.59 (moderate agreement). CONCLUSIONS: Using Shepherd's grading system there was good agreement between pathologists in reporting LPI in colonic carcinomas. The reporting of EMVI in colonic carcinomas on haematoxylin and eosin-stained slides had only poor to moderate agreement however, even amongst gastrointestinal pathologists working together in a single unit. Introduction of standardized criteria and/or the use of an elastin stain in the diagnosis of EMVI may assist in improving interobserver agreement.

Polymorphisms in VEGF and IL-8 predict tumor recurrence in stage III colon cancer.

BACKGROUND: Identifying molecular markers for tumor recurrence is critical in successfully selecting patients with stage III colon cancer who are more likely to benefit from adjuvant chemotherapy. The present study analyzed a subset of 10 polymorphisms within eight genes involved in the tumor angiogenesis pathway and their impact on prognosis in stage III colon cancer patients treated with adjuvant chemotherapy. PATIENTS AND METHODS: Blood samples were obtained from 125 patients with locally advanced colon cancer at University of Southern California medical facilities. DNA was extracted from peripheral blood and the genotypes were analyzed using PCR-restriction fragment length polymorphism and 5'-end [gamma-(33)P] ATP-labeled PCR protocols. RESULTS: Polymorphisms in vascular endothelial growth factor (VEGF) (C+936T; P = 0.003, log-rank test) and interleukin-8 (IL-8) (T-251A; P = 0.04, log-rank test) were independently associated with risk of recurrence in stage III colon cancer patients. In combined analysis, grouping alleles into favorable versus nonfavorable alleles, high expression variants of VEGF C+936T and IL-8 T-251A were associated with a higher likelihood of developing tumor recurrence (P < 0.001). CONCLUSION: High expression variants of VEGF C+936T and IL-8 T-251A were associated with shorter time to tumor recurrence, indicating that the analysis of angiogenesis-related gene polymorphisms may help to identify patient subgroups at high risk for tumor recurrence.

Effect of dietary tetradecylthioacetic acid on colon cancer growth studied by dynamic contrast enhanced MRI.

PURPOSE: To evaluate the effects of diets supplemented with the modified fatty acid tetradecylthioacetic acid (TTA) and fish protein hydrolysate (FPH) on tumor growth of the human colon cancer cell line SW620, and to investigate the properties of tumor vasculature by dynamic contrast-enhanced MRI in a human tumor xenograft. EXPERIMENTAL DESIGN: SW620 cells were grown in vitro in presence of TTA and palmitic acid and proliferation was measured by thymidine incorporation. The xenograft study in mice was performed with four distinct diets: (a) control diet; (b) diet with TTA; (c) diet with TTA and FPH; and (d) diet with FPH. SW620 cells were injected subcutaneously, and dynamic contrast enhanced (DCE) MRI was performed on a Bruker BioSpec 7T system. The data was analyzed by two-compartment modeling of the contrast enhancement, initial area under the curve (IAUC) and by use of relative signal intensity (RSI) distributions. RESULTS: The in vitro cell studies revealed that TTA reduced tumor cell proliferation as a function of both dose and time. The in vivo tumor growth was significantly reduced for the two groups fed TTA, as compared to the control group. The mean 10(th) percentile RSI, v(e) and IAUC for the TTA group were significant higher than for the control group. CONCLUSIONS: This study confirms the growth inhibitory effects of TTA, both in vitro and in vivo, in a colon cancer model. The analysis of DCE-MRI data showed that TTA influences the vascular properties of the tumor in addition to the growth.

Selective occlusion of tumor blood vessels by targeted delivery of an antibody-photosensitizer conjugate.

The irregular vasculature and high interstitial pressure of solid tumors hinder the delivery of cytotoxic agents to cancer cells. As a consequence, the doses of chemotherapy necessary to achieve complete tumor eradication are associated with unacceptably high toxicities. The selective thrombosis of tumor blood vessels has been postulated as an alternative avenue for combating cancer, depriving tumors of nutrients and oxygen and causing an avalanche of tumor cell deaths. The human antibody L19, specific to the EDB domain of fibronectin, a marker of angiogenesis, is capable of selective in vivo localization around tumor blood vessels and is thus a suitable agent for delivering toxic payloads to the tumor neovasculature. Here we show that a chemical conjugate of the L19 antibody with the photosensitizer bis(triethanolamine)Sn(IV) chlorin e(6), after intravenous injection and irradiation with red light, caused an arrest of tumor growth in mice with subcutaneous tumors. By contrast, a photosensitizer conjugate obtained with an antibody of identical pharmacokinetic properties but irrelevant specificity did not exhibit a significant therapeutic effect. These results confirm that vascular targeting strategies, aimed at the selective occlusion/disruption of tumor blood vessels, have a significant anticancer therapeutic potential and encourage the use of antibody-photosensitizer conjugates for the therapy of superficial tumors and possibly other angiogenesis-related pathologies.

Angiogenesis and antiangiogenic therapy of colon cancer liver metastasis.

The fact that tumor growth and metastatic spread relies on angiogenesis has been widely proven and accepted. The understanding of cancer biology and metastasis formation has led to the development of new therapeutic approaches that target tumor biology. The survival and establishment of metastatic lesions depend on a shift in the normal balance of proangiogenic and antiangiogenic factors that favor angiogenesis. Colorectal cancer is one of the leading cancer deaths worldwide. Angiogenesis has been associated with colon cancer progression and metastatic spread, thereby significantly affecting patient survival. New experimental approaches that inhibit angiogenic processes have demonstrated promising antineoplastic effects on metastatic colorectal cancer and are partially being investigated in clinical trials. This review focuses on angiogenesis in colorectal cancer metastasis formation as a target for antiangiogenic therapy, describing the experience from experimental studies and current clinical trials.