Endothelial cells and angiogenic growth factors in cancer growth and metastasis. Introduction

Discovery of potent thieno[2,3-d]pyrimidine VEGFR-2 inhibitors: Design, synthesis and enzyme inhibitory evaluation supported by molecular dynamics simulations

Vascular endothelial growth factor receptor (VEGFR) is one of the well-known targets that control angiogenesis and cancer progression. In this study, we are reporting the design, synthesis and biological evaluation of a series of 4-substituted thieno[2,3-d]pyrimidine derivatives as VEGFR-2 inhibitors. The design of these compounds was based on interactions extracted from crystal structure of potent pyrrolo[3,2-d]pyrimidine inhibitor VIII with VEGFR-2 (PDB: 3VHE). In addition to these interactions, the new compounds were also designed to interact with residues in the solvent accessible region such as Asn923. Accordingly, the thienopyrimidine target compounds were synthesized and subjected to VEGFR-2 enzyme inhibition assay. Several target compounds (7d-f, 8b-c, 8e-g and 15c) exhibited potent inhibitory activities against VEGFR-2 with IC₅₀ values in low nanomolar range. Compounds 8b and 8e revealed exceptionally potent inhibitory activity with IC₅₀ of 5 and 3.9 nM, respectively. The molecular docking analysis and molecular dynamics simulation were also performed to further investigate these findings.

Exosome in Hepatocellular Carcinoma: an update

Hepatocellular carcinoma (HCC) is a common malignant tumor in the digestive tract with limited therapeutic choices. Intercellular communication among cancer cells and their microenvironment is crucial to disease progression. Exosomes are extracellular vesicles secreted by multiple types of cells into the extracellular space, which contain a variety of active components of secretory cells, including lipids, proteins, RNA and DNA. This vesicle structure involves in the exchange of materials and information between cells and plays an important role in the development of many diseases. Studies have shown that exosomes participate in the communication between HCC cells and non-HCC cells and regulate the occurrence and development of hepatocellular carcinoma. Therefore, exosomes may be specific biomarkers for early diagnosis and metastasis of HCC, which are also potential targets for the treatment of HCC. This review summarizes the characteristic, types and biological functions of exosomes and discusses their research progress and application prospects in the diagnosis and treatment of HCC.

Syndecan-1 Overexpressing Mesothelioma Cells Inhibit Proliferation, Wound Healing, and Tube Formation of Endothelial Cells

Simple Summary

The transmembrane proteoglycan syndecan-1 (SDC-1) is an important mediator of cell-matrix interactions. The heparan sulfate side-chains of SDC-1 can bind to a multitude of growth factors, cytokines, and chemokines, thereby regulating a plethora of physiological and pathological processes, including angiogenesis. The extracellular region of SDC-1 can be released from the cell surface by the action of sheddases including matrix metalloproteinase-7 and 9, resulting in a soluble protein that is still active and can act as a competitive activator or inhibitor of the cell surface receptor. Accelerated shedding and loss of cell surface SDC-1 is associated with epithelial to mesenchymal transition (EMT) and achievement of a more invasive phenotype in malignant mesothelioma (MM). Transfection with SDC-1 reverts the morphology in epithelioid direction and inhibits the proliferation and migration of MM cells. This study aimed to investigate the role of SDC-1 in angiogenesis. We demonstrate that overexpression and silencing of SDC-1 alters the secretion of angiogenic proteins in MM cells. Upon SDC-1 overexpression, several factors collectively inhibit the proliferation, wound closure, and tube formation of endothelial cells, whereas SDC-1 silencing only affects wound healing.

Abstract

Malignant mesothelioma (MM) is an aggressive tumor of the serosal cavities. Angiogenesis is important for mesothelioma progression, but so far, anti-angiogenic agents have not improved patient survival. Our hypothesis is that better understanding of the regulation of angiogenesis in this tumor would largely improve the success of such a therapy. Syndecan-1 (SDC-1) is a transmembrane heparan sulfate proteoglycan that acts as a co-receptor in various cellular processes including angiogenesis. In MM, the expression of SDC-1 is generally low but when present, SDC-1 associates to epithelioid differentiation, inhibition of tumor cell migration and favorable prognosis, meanwhile SDC-1 decrease deteriorates the prognosis. In the present study, we studied the effect of SDC-1 overexpression and silencing on MM cells ability to secrete angiogenic factors and monitored the downstream effect of SDC-1 modulation on endothelial cells proliferation, wound healing, and tube formation. This was done by adding conditioned medium from SDC-1 transfected and SDC-1 silenced mesothelioma cells to endothelial cells. Moreover, we investigated the interplay and molecular functional changes in angiogenesis in a co-culture system and characterized the soluble angiogenesis-related factors secreted to the conditioned media. We demonstrated that SDC-1 over-expression inhibited the proliferation, wound healing, and tube formation of endothelial cells. This effect was mediated by a multitude of angiogenic factors comprising angiopoietin-1 (Fold change ± SD: 0.65 ± 0.07), FGF-4 (1.45 ± 0.04), HGF (1.33 ± 0.07), NRG1-β1 (1.35 ± 0.08), TSP-1 (0.8 ± 0.02), TIMP-1 (0.89 ± 0.01) and TGF-β1 (1.35 ± 0.01). SDC-1 silencing increased IL8 (1.33 ± 0.06), promoted wound closure, but did not influence the tube formation of endothelial cells. Pleural effusions from mesothelioma patients showed that Vascular Endothelial Growth Factor (VEGF) levels correlate to soluble SDC-1 levels and have prognostic value. In conclusion, SDC-1 over-expression affects the angiogenic factor secretion of mesothelioma cells and thereby inhibits endothelial cells proliferation, tube formation, and wound healing. VEGF could be used in prognostic evaluation of mesothelioma patients together with SDC-1.

Impact of the Delayed Initiation of Adjuvant Chemotherapy in the Outcome of Triple Negative Breast Cancer

BACKGROUND

Adjuvant chemotherapy decreases the recurrence risk and improves survival rates; however, it is unclear whether a delayed initiation is associated with adverse outcomes, especially in triple negative breast cancer (TNBC). In this study, we evaluated the influence of the time to start adjuvant chemotherapy (TTC) in the outcomes of TNBC.

PATIENTS AND METHODS

We retrospectively analyzed 15 years of data from patients with TNBC who received adjuvant chemotherapy at the Instituto Nacional de Enfermedades Neoplasicas (Lima, Peru). TTC was categorized into 4 groups: ≤ 30, 31 to 60, 61 to 90, and ≥ 91 days. We evaluated overall survival (OS) and distant recurrence-free survival (DRFS). Cox proportional hazard models were used to identify prognostic factors.

RESULTS

In total, 687 patients were included. The mean age at diagnosis was 49.1 years (SD, 11.8 years), and most (62.6%) patients had pathologic stage T2. The median TTC was 48.1 days (SD, 27.4 days); 189 (27.5%) received chemotherapy ≤ 30 days; 329 (47.9%), between 31 and 60 days; 115 (16.7%), between 61 and 90 days; and 54 (7.9%) in ≥ 90 days. In the multivariate analysis, a TTC between 31 and 60 days (hazard ratio [HR], 1.78; 95% confidence interval [CI], 1.17-2.72), 61 and 90 days (HR, 2.38; 95%CI, 1.43-3.97), and ≥ 91 days (HR, 2.45; 95% CI, 1.32-4.55) was associated with an increased mortality in contrast with a TTC < 30 days. Although a TTC between 31 and 60 days, 61 and 90 days, and ≥ 91 days was associated with an increased risk of DRFS (HR, 1.86; 95% CI, 1.24-2.79; HR, 2.34, 95% CI, 1.42-3.867; and HR, 3.16; 95% CI, 1.78-5.61, respectively).

CONCLUSION

A delaying in TTC ≥ 30 days was associated with poorer outcomes. Our data suggest that several efforts should be conducted to avoid a delayed TTC in patients with TNBC.

Clinical Impact of Delayed Initiation of Adjuvant Chemotherapy Among Patients With Stage II/III Gastric Cancer: Can We Do Better?

Background: To investigate the prognostic effects and risk factors of the omission and delay of postoperative chemotherapy of stage II/III gastric cancer (GC). Methods: The clinicopathological data of 1,520 patients undergoing radical gastrectomy for stage II/III GC were collected and retrospectively analyzed. We defined the chemotherapy delayed until more than 60 days after radical gastrectomy and the complete omission of chemotherapy as unacceptable chemotherapy initiation (UAC), whereas the chemotherapy conducted within 60 days of radical gastrectomy was defined as acceptable chemotherapy initiation (AC). The survival between the two groups was compared, and the trends and risk factors of UAC were analyzed. Results: There were 539 (35.5%) patients with UAC. The overall survival (OS) and disease-free survival of the UAC group patients were significantly inferior to those in the AC group (p < 0.001). Cox multivariate analysis demonstrated that UAC is an independent predictor of OS (p < 0.05). The OS and disease-free survival of the patients in the UAC group were close to those of the patients without chemotherapy (p > 0.05). Logistic analysis showed that female, old age, a self-paid status, a very low social status, high American Society of Anesthesiologists scores, intra-abdominal surgery history, and serious postoperative complications were independent risk factors of UAC (all p < 0.05). The radar chart shows the risk factors of UAC changed with time. Conclusions: UAC after radical gastrectomy is an independent risk factor for the prognosis of stage II/III GC patients. However, no significant decline of UAC has been achieved recently and should call for the attention of both government and clinicians.

Retinal capillary perfusion: Spatial and temporal heterogeneity

The central role of the cardiovascular system is to maintain adequate capillary perfusion. The spatially and temporally heterogeneous nature of capillary perfusion has been reported in some organs. However, such heterogeneous perfusion properties have not been sufficiently explored in the retina. Arguably, spatial and temporal heterogeneity of capillary perfusion could be more predominant in the retina than that in other organs. This is because the retina is one of the highest metabolic demand neural tissues yet it has a limited blood supply due to optical requirements. In addition, the unique heterogeneous distribution of retinal neural cells within different layers and regions, and the significant heterogeneity of intraretinal oxygen distribution and consumption add to the complexity. Retinal blood flow distribution must match consumption of nutrients such as oxygen and glucose within the retina at the cellular level in order to effectively maintain cell survival and function. Sophisticated local blood flow control in the microcirculation is likely required to control the retinal capillary perfusion to supply local retinal tissue and accommodate temporal and spatial variations in metabolic supply and demand. The authors would like to update the knowledge of the retinal microvessel and capillary network and retinal oxidative metabolism from their own studies and the work of others. The coupling between blood supply and energy demands in the retina is particularly interesting. We will mostly describe information regarding the retinal microvessel network and retinal oxidative metabolism relevant to the spatial and temporal heterogeneity of capillary perfusion. We believe that there is significant and necessary spatial and temporal heterogeneity and active regulation of retinal blood flow in the retina, particularly in the macular region. Recently, retinal optical coherence tomography angiography (OCTA) has been widely used in ophthalmology, both experimentally and clinically. OCTA could be a valuable tool for examining retinal microvessel and capillary network structurally and has potential for determining retinal capillary perfusion and its control. We have demonstrated spatial and temporal heterogeneity of capillary perfusion in the retina both experimentally and clinically. We have also found close relationships between the smallest arterioles and capillaries within paired arterioles and venules and determined the distribution of smooth muscle cell contraction proteins in these vessels. Spatial and temporal heterogeneity of retinal capillary perfusion could be a useful parameter to determine retinal microvessel regulatory capability as an early assay for retinal vascular diseases. This topic will be of great interest, not only for the eye but also other organs. The retina could be the best model for such investigations. Unlike cerebral vessels, retinal vessels can be seen even at the capillary level. The purpose of this manuscript is to share our current understanding with the readers and encourage more researchers and clinicians to investigate this field. We begin by reviewing the general principles of microcirculation properties and the spatial and temporal heterogeneity of the capillary perfusion in other organs, before considering the special requirements of the retina. The local heterogeneity of oxygen supply and demand in the retina and the need to have a limited and well-regulated retinal circulation to preserve the transparency of the retina is discussed. We then consider how such a delicate balance of metabolic supply and consumption is achieved. Finally we discuss how new imaging methodologies such as optical coherence tomography angiography may be able to detect the presence of spatial and temporal heterogeneity of capillary perfusion in a clinical setting. We also provide some new information of the control role of very small arterioles in the modulation of retinal capillary perfusion which could be an interesting topic for further investigation.

CDK8 regulates the angiogenesis of pancreatic cancer cells in part via the CDK8-β-catenin-KLF2 signal axis

BACKGROUND

CDK8 is associated with the transcriptional Mediator complex and has been shown to regulate several transcription factors implicated in cancer. As a pancreatic cancer oncogene, the role of CDK8 in cancer angiogenesis remains unclear. Here, we investigated the contribution of CDK8 in pancreatic cancer angiogenesis and examined the underlying molecular mechanisms.

METHODS

CDK8 expression was evaluated via immunohistochemistry, western blotting, and qRT-PCR in relation to the clinicopathological characteristics of pancreatic cancer patients. The effects of silencing or overexpressing CDK8 on cancer angiogenesis were assessed in vitro by western blotting assays in pancreatic cancer cell lines and in vivo with nude mice xenograft models.

RESULTS

Compared with adjacent normal tissues, pancreatic cancer tissues showed upregulation of CDK8 expression, which was inversely correlated with T grade, liver metastasis, size, lymph node metastasis and poor survival. CDK8 overexpression promoted angiogenesis in pancreatic cancer via activation of the CDK8-β-catenin-KLF2 signaling axis, as demonstrated by the upregulation and downregulation of signals representing the rate-limiting steps in angiogenesis. Silencing CDK8 inhibited angiogenesis in pancreatic cancer in vitro. Additionally, these results were confirmed in nude mice xenograft models in vivo.

CONCLUSIONS

CDK8 promotes angiogenesis in pancreatic cancer via activation of the CDK8-β-catenin-KLF2 signaling axis, thus providing valid targets for the treatment of pancreatic cancer.

The effect of vascular endothelial growth factor-1 expression on survival of advanced colorectal cancer patients

Colorectal cancer is third leading cause of cancer mortality. About 60% of patients had already developed metastasis at the time of diagnosis. Vascular endothelial growth factor (VEGF) is crucial for the development of neovascularization and hence metastasis. This study aimed at investigating the relation between the expression of VEGF in biopsies from surgically dissected colon cancer and the survival of those patients. Biopsies were collected from 86 patients with advanced colon cancer and sections were stained by immunohistochemistry for VEGF. Patients received chemotherapy after the operation and were followed up for disease progression and survival. The clinical data were statistically analyzed with respect to the immunohistochemistry results. The survival of the patients was significantly longer in the patients for whom biopsies showed negative or weak expression of VEGF in comparison to those with moderate to high expression (p-value = 0.04). The expression of VEGF was more frequent in the patients who died as a consequence of the disease in comparison to the 10-year survivors. In conclusion, VEGF could be related to the survival of the patients with colorectal carcinoma and should be considered as a predictor of the prognosis.

Identifying the neck margin status of ductal adenocarcinoma in the pancreatic head by multiphoton microscopy

Complete surgical resection is the only option for improving the survival of patients with ductal adenocarcinoma in the pancreatic head. After resection, determining the status of resection margins (RMs) is crucial for deciding on the nature of the follow-up treatment. The purpose of this study was to evaluate whether multiphoton microscopy (MPM) could be considered a reliable tool for determining the status of pancreatic neck margins by identifying tumour cells of ductal adenocarcinoma in these margins in the pancreatic head, and our results were affirmative. In particular, MPM could identify tumour cells in the nerves. It was also found that the quantification of the difference between normal duct cells and tumour cells was possible. In addition, the content of collagen could be quantified and used as a marker for differentiating ductal adenocarcinoma in the pancreatic head from normal pancreatic tissues, eventually leading to the identification of R0 and R1 resections of the pancreatic neck margin. With the development of the clinical applications of the multiphoton endoscope, MPM has the potential to provide in vivo real-time identification of RM status during surgery.

Fertility preservation with ovarian stimulation and time to treatment in women with stage II-III breast cancer receiving neoadjuvant therapy

PURPOSE

To determine whether fertility preservation with ovarian stimulation (OS) results in treatment delay in breast cancer (BC) patients receiving neoadjuvant therapy (NAT).

METHODS

This is a retrospective study of women screened for the prospective neoadjuvant ISPY2 trial at the University of California San Francisco. All patients were <43, had stage II-III BC, and received neoadjuvant therapy. Time to initiation of NAT was compared between women who underwent OS (STIM) and women who did not (control). Patient and tumor characteristics, as well as oncologic outcomes, were compared between STIM and control groups.

RESULTS

82 patients were included (34 STIM and 48 control). STIM patients were overall younger (mean = 35 vs. 36.9 years old, p = 0.06), and more likely to be childless (79.4 vs 31.2%, p < 0.0001) than controls. Mean time from diagnosis to initiation of NAT was 40 days, with no significant difference between STIM and control groups (mean 39.8 days vs 40.9 days, p = 0.75). Mean time from diagnosis to fertility consultation was 16.3 days. With median follow-up of 79 months, 16 (19.5%) patients have recurred or died from BC. Rates of pCR, recurrence, and death were similar in both groups. Six of 34 STIM patients have undergone embryo transfer, resulting in one patient with two live births.

CONCLUSION

Fertility preservation with OS can be performed in the neoadjuvant setting without delay in initiation of systemic therapy and should be discussed with all early-stage BC patients of reproductive age.

Efficacy and safety of aflibercept in in vitro and in vivo models of retinoblastoma

Background

To evaluate the inhibitory effects of aflibercept on the growth and subretinal invasion of retinoblastoma.

Methods

Xenotransplantation and orthotopic mouse models were created by injecting Y-79 cells subcutaneously and intravitreally, respectively. After induction of retinoblastoma, animals were intraperitoneally injected with aflibercept (25 mg/kg body weight) or saline twice a week for 3 weeks. Tumor size was measured weekly and compared between the two groups. At 4 weeks, animals were sacrificed and an immunohistochemical examination was conducted to compare the microvascular density and degree of apoptosis between groups. In addition, the degree of choroidal invasion was also analyzed in the orthotopic xenotransplantation model. A co-culture system of Y-79 or WERI-Rb-1 cells and human umbilical vein endothelial cells (HUVECs) was used for in vitro experiments, and the anti-angiogenic effect of aflibercept was evaluated by analyzing cell numbers.

Results

In the Y-79 xenotransplantation model, aflibercept treatment significantly inhibited tumor growth at 4 weeks versus baseline compared with saline-injected mice (188.53 ± 118.53 mm³ vs. 747.87 ± 118.83 mm³, respectively, P < 0.001). Tumors isolated from aflibercept-treated mice contained fewer blood vessels (8.59 % ± 7.60 % vs. 14.91 % ± 4.53 %, respectively, P < 0.05) and an increased number of apoptotic cells (15.10 ± 9.13 vs. 4.44 ± 2.24, respectively, P < 0.05). In the orthotopic model, the degree of subretinal invasion of tumor cells was significantly reduced after aflibercept treatment (0.07 ± 0.06 vs. 0.15 ± 0.10, P < 0.05). And addition of aflibercept to co-cultures of HUVECs and Y-79, WERI-Rb-1 cells significantly reduced HUVEC proliferation.

Conclusions

Aflibercept reduced retinoblastoma angiogenesis in association with a significant reduction in tumor growth and invasion. These findings suggest that aflibercept could be used in an adjuvant role together with systemic chemotherapy to reduce tumor size and angiogenesis in retinoblastoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0451-7) contains supplementary material, which is available to authorized users.

Walker 256 Tumor Growth Suppression by Crotoxin Involves Formyl Peptide Receptors and Lipoxin A₄

We investigated the effects of Crotoxin (CTX), the main toxin of South American rattlesnake (Crotalus durissus terrificus) venom, on Walker 256 tumor growth, the pain symptoms associated (hyperalgesia and allodynia), and participation of endogenous lipoxin A₄. Treatment with CTX (s.c.), daily, for 5 days reduced tumor growth at the 5th day after injection of Walker 256 carcinoma cells into the plantar surface of adult rat hind paw. This observation was associated with inhibition of new blood vessel formation and decrease in blood vessel diameter. The treatment with CTX raised plasma concentrations of lipoxin A₄ and its natural analogue 15-epi-LXA₄, an effect mediated by formyl peptide receptors (FPRs). In fact, the treatment with Boc-2, an inhibitor of FPRs, abolished the increase in plasma levels of these mediators triggered by CTX. The blockage of these receptors also abolished the inhibitory action of CTX on tumor growth and blood vessel formation and the decrease in blood vessel diameter. Together, the results herein presented demonstrate that CTX increases plasma concentrations of lipoxin A₄ and 15-epi-LXA₄, which might inhibit both tumor growth and formation of new vessels via FPRs.

Delayed Initiation of Adjuvant Chemotherapy Among Patients With Breast Cancer

IMPORTANCE

Adjuvant chemotherapy improves outcomes of patients with breast cancer. However, the optimal timing of chemotherapy initiation is unknown. Delayed administration can decrease the benefit of cytotoxic systemic therapies.

OBJECTIVE

To identify the determinants in delayed chemotherapy initiation and to determine the relationship between time to chemotherapy (TTC) and outcome according to breast cancer subtype. We hypothesized that prolonged TTC would be associated with adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

In an observational, population-based investigation using data from the California Cancer Registry, we studied a total of 24 843 patients with stage I to III invasive breast cancer diagnosed between January 1, 2005, and December 31, 2010, and treated with adjuvant chemotherapy. Data analysis was performed between August 2014 and August 2015.

MAIN OUTCOMES AND MEASURES

Time to chemotherapy was defined as the number of days between surgery and the first dose of chemotherapy, and delayed TTC was defined as 91 or more days from surgery to the first dose of adjuvant chemotherapy. We evaluated overall survival and breast cancer-specific survival. Logistic regression and Cox proportional hazard models were used.

RESULTS

In all, 24 843 patients were included. Median age at diagnosis was 53 years, and median was TTC was 46 days. Factors associated with delays in TTC included low socioeconomic status, breast reconstruction, nonprivate insurance, and Hispanic ethnicity or non-Hispanic black race. Compared with patients receiving chemotherapy within 31 days from surgery, there was no evidence of adverse outcomes among those with TTC of 31 to 60 or 60 to 90 days. Patients treated 91 or more days from surgery experienced worse overall survival (hazard ratio [HR], 1.34; 95% CI, 1.15-1.57) and worse breast cancer-specific survival (HR, 1.27; 95% CI, 1.05-1.53). In a subgroup analysis according to subtype, longer TTC caused patients with triple-negative breast cancer to have worse overall survival (HR, 1.53; 95% CI, 1.17-2.00) and worse breast cancer-specific survival (HR, 1.53; 95% CI 1.17-2.07).

CONCLUSIONS AND RELEVANCE

For patients with breast cancer, adverse outcomes are associated with delaying initiation of adjuvant chemotherapy 91 or more days. Delayed TTC was particularly detrimental among patients with triple-negative breast cancer. The determinants of delays in chemotherapy initiation appeared to be sociodemographic, and clinicians should provide timelier care to all patients.

DCLAK11, a multi-tyrosine kinase inhibitor, exhibits potent antitumor and antiangiogenic activity in vitro

AIM

To investigate the molecular targets of DCLAK11, a novel compound discovered from a series of substituted pyridin-3-amine derivatives, and to characterize its anti-tumor properties in vitro.

METHODS

Kinase inhibition was measured by an ELISA assay. Cell viability was assessed with an SRB or a CCK8 assay. The alterations induced by kinase signaling proteins in cancer cells were detected by Western blot. Apoptosis was determined by an Annexin V-PI assay. The following assays were used to evaluate the impact on angiogenesis: wound-healing, Transwell, tube formation and microvessel outgrowth from rat aortic rings.

RESULTS

DCLAK11 was a multi-targeted kinase inhibitor that primarily inhibited the EGFR, HER2, and VEGFR2 tyrosine kinases with IC50 value of 6.5, 18, and 31 nmol/L, respectively. DCLAK11 potently inhibited the proliferation of EGFR- and HER2-driven cancer cells: its IC50 value was 12 and 22 nmol/L, respectively, in HCC827 and HCC4006 cells with EGFR exon deletions, and 19 and 81 nmol/L, respectively, in NCI-N87 and BT474 cells with HER2 amplification. Consistently, DCLAK11 blocked the EGFR and HER2 signaling in cancer cells with either an EGFR or a HER2 aberration. Furthermore, DCLAK11 effectively induced EGFR/HER2-driven cell apoptosis. Moreover, DCLAK11 exhibited anti-angiogenic activity, as shown by its inhibitory effect on the proliferation, migration and tube formation of human umbilical vascular endothelial cells and the microvessel outgrowth of rat aortic rings.

CONCLUSIONS

DCLAK11 is a multi-targeted kinase inhibitor with remarkable potency against tyrosine kinases EGFR, HER2 and VEGFR2, which confirms its potent anti-cancer activity in EGFR- and HER2-addicted cancers and its anti-angiogenic activity.

Immunohistochemical Expression of Angiogenic Factors by Neoplastic Epithelial Cells Is Associated With Canine Prostatic Carcinogenesis

The dog is the only species, other than humans, in which spontaneous prostatic cancer occurs; therefore, dogs are a valuable model for the study of factors that regulate tumor progression. Angiogenesis is important in the development and spread of a variety of cancers, including prostate cancer. To better define the role of cancer epithelial cells in prostate cancer neovascularization, immunohistochemical staining for angiogenic factors (vascular endothelial growth factor [VEGF], platelet endothelial cell adhesion molecule-1 [PECAM-1], Tie-2, and fibroblast growth factor-2 [FGF-2]) was performed on formalin-fixed, paraffin-embedded tissues from 10 normal prostates, 15 hyperplastic prostates, and 11 prostatic carcinomas from dogs. Normal and hyperplastic epithelial cells were negative for PECAM-1, VEGF, and Tie-2, while the same markers were expressed with a variable intensity of cytoplasmic staining by neoplastic cells. Mild to moderate FGF-2 staining was detected in all normal prostates with less than 10% of positive cells, mainly distributed in the basal layer. The percentage of FGF-2-positive hyperplastic cells was variable, with both basal and secretory cells exhibiting a perinuclear to diffuse cytoplasmic staining. The mean number of positive cells and the intensity of staining were higher in prostatic carcinomas than normal and hyperplastic prostates. Moreover, microvessel density analyzed on PECAM-1-stained slides was increased in prostate cancer compared with normal and hyperplastic prostates. Therefore, prostatic neoplastic cells are capable of simultaneous expression of various angiogenic factors and may increase tumor proliferation and angiogenesis in a paracrine and autocrine fashion.

Hypercoagulation in colorectal cancer: what can platelet indices tell us?

Colorectal cancer, as all solid malignancies, is accompanied by changes in the haemostatic mechanism favoring the establishment of a thrombotic potential, with platelets playing a key-role in this framework; they further link colorectal cancer progression and hypercoagulation with the immune-response against the neoplastic spread. Under this rationale, various studies have assessed the use of platelet indices as prognostic markers of the biological behavior of colorectal cancer, demonstrating significant results. We herein attempt to summarize in a narrative and critical approach the relevant available data and the underlying pathophysiology, stressing the necessity of a more thorough understanding and future implementation of platelet indices in all stages of care we deliver to colorectal cancer patients.

Morphological characterization of sprouting and intussusceptive angiogenesis by SEM in oral squamous cell carcinoma

The word angiogenesis indicates the formation of new vascular segments from existing vessels such as capillaries and venules. Blood vessel formation in tumors is the result of rapid, disorganized vascular growth through two distinct mechanisms: sprouting and intussusceptive angiogenesis. The objective of this study was to elucidate the morphological aspects of these two vascular growth mechanisms in oral squamous cell carcinoma induced in hamster buccal pouch. Eight Syrian golden hamsters had their right buccal pouch treated with DMBA 0.5% and 10% carbamide peroxide for 90 days in order to produce squamous cell carcinoma in this site. Next, buccal pouches of the animals were submitted to the vascular corrosion technique and then analyzed by scanning electron microscopy. The vascular figures of sprouts were observed in the entire vascular network of the buccal pouches, as opposed to the intussusceptive angiogenesis that was predominantly observed in the sub-epithelial network. It was possible to differentiate the figures of sprouts from artifacts by the analysis of the blind ending of these structures. Intussusceptive angiogenesis was identified by the presence of holes trespassing the lumen of the capillaries. Vascular expansion occurred through intussusceptive angiogenesis in two ways: by the fusion of the pillars to form a new capillary and, by increasing the girth of the pillar to form meshes. The method of corrosion associated with scanning electron microscopy proved to be an excellent tool to study the two types of angiogenesis in oral squamous cell carcinoma in the hamster buccal pouch.

Clinical impact of delaying initiation of adjuvant chemotherapy in patients with breast cancer

PURPOSE

For patients with breast cancer (BC), the optimal time to initiation of adjuvant chemotherapy (TTC) after definitive surgery is unknown. We evaluated the association between TTC and survival according to breast cancer subtype and stage at diagnosis.

PATIENTS AND METHODS

Women diagnosed with BC stages I to III between 1997 and 2011 who received adjuvant chemotherapy at our institution were included. Patients were categorized into three groups according to TTC: ≤ 30, 31 to 60, and ≥ 61 days. Survival outcomes were estimated and compared according to TTC and by BC subtype.

RESULTS

Among the 6,827 patients included, the 5-year overall survival (OS), relapse-free survival (RFS), and distant RFS (DRFS) estimates were similar for the different TTC categories. Initiation of chemotherapy ≥ 61 days after surgery was associated with adverse outcomes among patients with stage II (DRFS: hazard ratio [HR], 1.20; 95% CI, 1.02 to 1.43) and stage III (OS: HR, 1.76; 95% CI, 1.26 to 2.46; RFS: HR, 1.34; 95% CI, 1.01 to 1.76; and DRFS: HR, 1.36; 95% CI, 1.02 to 1.80) BC. Patients with triple-negative BC (TNBC) tumors and those with human epidermal growth factor receptor 2 (HER2) -positive tumors treated with trastuzumab who started chemotherapy ≥ 61 days after surgery had worse survival (HR, 1.54; 95% CI, 1.09 to 2.18 and HR, 3.09; 95% CI, 1.49 to 6.39, respectively) compared with those who initiated treatment in the first 30 days after surgery.

CONCLUSION

TTC influenced survival outcomes in the overall study cohort. This finding was particularly meaningful for patients with stage III BC, TNBC, and trastuzumab-treated HER2-positive tumors who experienced worse outcomes when chemotherapy was delayed. Our findings suggest that early initiation of chemotherapy should be granted for patients in these high-risk groups.

Estrogen mediated-activation of miR-191/425 cluster modulates tumorigenicity of breast cancer cells depending on estrogen receptor status

MicroRNAs (miRNAs), single-stranded non-coding RNAs, influence myriad biological processes that can contribute to cancer. Although tumor-suppressive and oncogenic functions have been characterized for some miRNAs, the majority of microRNAs have not been investigated for their ability to promote and modulate tumorigenesis. Here, we established that the miR-191/425 cluster is transcriptionally dependent on the host gene, DALRD3, and that the hormone 17β-estradiol (estrogen or E2) controls expression of both miR-191/425 and DALRD3. MiR-191/425 locus characterization revealed that the recruitment of estrogen receptor α (ERα) to the regulatory region of the miR-191/425-DALRD3 unit resulted in the accumulation of miR-191 and miR-425 and subsequent decrease in DALRD3 expression levels. We demonstrated that miR-191 protects ERα positive breast cancer cells from hormone starvation-induced apoptosis through the suppression of tumor-suppressor EGR1. Furthermore, enforced expression of the miR-191/425 cluster in aggressive breast cancer cells altered global gene expression profiles and enabled us to identify important tumor promoting genes, including SATB1, CCND2, and FSCN1, as targets of miR-191 and miR-425. Finally, in vitro and in vivo experiments demonstrated that miR-191 and miR-425 reduced proliferation, impaired tumorigenesis and metastasis, and increased expression of epithelial markers in aggressive breast cancer cells. Our data provide compelling evidence for the transcriptional regulation of the miR-191/425 cluster and for its context-specific biological determinants in breast cancers. Importantly, we demonstrated that the miR-191/425 cluster, by reducing the expression of an extensive network of genes, has a fundamental impact on cancer initiation and progression of breast cancer cells.

Effects of autocrine vascular endothelial growth factor (VEGF) in non-small cell lung cancer cell line A549

It is reported that the autocrine loop of the vascular endothelial growth factor (VEGF) is crucial for the survival and proliferation of non-small cell lung cancer (NSCLC) tumors. In this study we aimed to systematically investigate the role of autocrine vascular VEGF in NSCLC cell line A549 through inhibition of endogenous VEGF. A549 cells were transfected with florescence-labeled VEGF oligodeoxynucleotide with lipofectamine. For the experimental group, cells were transfected with VEGF anti-sense oligodeoxynucleotide (ASODN), sense oligodeoxynucleotide (SODN) and mutant oligodeoxynuleotide (MODN) respectively. For the control group cells were mock transfected with lipofectamine or culture medium. At indicated time point after transfection, the expression levels of VEGF mRNA and protein in A549 cells were analyzed by RT-PCR and ELISA respectively. Cell viability was measured by the MTT assay. Cell cycle distribution was detected by flow cytometry. As revealed by RT-PCR assay, the mRNA level of VEGF in cells transfected with ASDON was significantly lower than the other four groups (P < 0.05) at 24 and 48 h after transfection. ELISA assay yielded similar result with significantly decreased level of VEGF protein expression (P < 0.05). The survival fraction of A549 cells transfected with ASDON was significantly lower than the other four groups (P < 0.05) at 24 h after transfection. Also the percentage of G2 phase cells of ASODN group was significantly lower than other four groups. Our data indicate that VEGF expression is efficiently inhibited in A549 cells by ASODN transfection and this inhibition leads to inhibited cell growth and impaired cell cycle distribution.

"Peripancreatic strands appearance" in pancreatic body and tail carcinoma: evaluation by multi-detector CT with pathological correlation

OBJECTIVES

In pancreatic body and tail carcinoma, "peripancreatic strands appearance" is frequently seen on multidetector CT (MDCT). The purpose of this study was to clarify the pathological and clinical implications of peripancreatic strands appearance.

METHODS

We retrospectively evaluated MDCT images in 17 patients with pancreatic body and tail carcinoma who underwent surgical resection. Peripancreatic strands appearance was defined as the strands structure deriving from the primary lesion and associated with increased CT attenuation of surrounding adipose tissues. All CT examinations were performed by contrast-enhanced MDCT with a multiplanar reformation technique.

RESULTS

Peripancreatic strands appearance was detected on MDCT in 13 (76%) patients. The maximum width of the peripancreatic strands seen on MDCT was 1.55 ± 0.36 mm (range, 1.0-2.5 mm). This CT finding was well correlated with extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa, including microvessels. This pathological finding was confirmed in all 13 patients with positive CT finding whereas it was not confirmed in the 4 patients with negative CT finding.

CONCLUSION

Peripancreatic strands appearance on MDCT in pancreatic body and tail carcinoma reflects extrapancreatic carcinoma invasion with marked fibrotic thickening of adipose tissue septa. This CT finding would indicate the property of carcinoma aggressiveness.

Prognostic biomarkers in ovarian cancer

Epithelial ovarian cancer (EOC) remains the most lethal gynecological malignancy despite several decades of progress in diagnosis and treatment. Taking advantage of the robust development of discovery and utility of prognostic biomarkers, clinicians and researchers are developing personalized and targeted treatment strategies. This review encompasses recently discovered biomarkers of ovarian cancer, the utility of published prognostic biomarkers for EOC (especially biomarkers related to angiogenesis and key signaling pathways), and their integration into clinical practice.

Endothelial cells are able to synthesize and release catecholamines both in vitro and in vivo

Recently it has been demonstrated that catecholamines are produced and used by macrophages and mediate immune response. The aim of this study is to verify whether endothelial cells (ECs), which are of myeloid origin, can produce catecholamines. We demonstrated that genes coding for tyrosine hydroxylase, Dopa decarboxylase, dopamine β hydroxylase (DβH), and phenylethanolamine-N-methyl transferase, enzymes involved in the synthesis of catecholamines, are all expressed in basal conditions in bovine aorta ECs, and their expression is enhanced in response to hypoxia. Moreover, hypoxia enhances catecholamine release. To evaluate the signal transduction pathway that regulates catecholamine synthesis in ECs, we overexpressed in bovine aorta ECs either protein kinase A (PKA) or the transcription factor cAMP response element binding, because PKA/cAMP response element binding activation induces tyrosine hydroxylase transcription and activity in response to stress. Both cAMP response element binding and PKA overexpression enhance DβH and phenylethanolamine-N-methyl transferase gene expression and catecholamine release, whereas H89, inhibitor of PKA, exerts the opposite effect, evidencing the role of PKA/cAMP response element binding transduction pathway in the regulation of catecholamine release in bovine aorta ECs. We then evaluated by immunohistochemistry the expression of tyrosine hydroxylase, Dopa decarboxylase, DβH, and phenylethanolamine-N-methyl transferase in femoral arteries from hindlimbs of C57Bl/6 mice 3 days after removal of the common femoral artery to induce chronic ischemia. Ischemia evokes tyrosine hydroxylase, Dopa decarboxylase, DβH, and phenylethanolamine-N-methyl transferase expression in the endothelium. Finally, the pharmacological inhibition of catecholamine release by fusaric acid, an inhibitor of DβH, reduces the ability of ECs to form network-like structures on Matrigel matrix. In conclusion, our study demonstrates for the first time that ECs are able to synthesize and release catecholamines in response to ischemia.

Novel compounds in the treatment of lung cancer: current and developing therapeutic agents

Lung cancer is the leading cause of cancer-related death in the United States. Though incremental advances have been made in the treatment of this devastating disease during the past decade, new therapies are urgently needed. Traditional cytotoxic agents have been combined with other modalities with improved survival for early-stage patients. Newer cytotoxic agents targeting the same or different mechanisms have been developed at different stages. Optimization of various chemotherapy regimens in different settings is one of the aims of current clinical trials. Some predictive biomarkers (eg, excision repair cross-complementing 1, ERCC1) and histotypes (eg, adenocarcinoma) are found to be associated with resistance/response to some cytotoxic drugs. Another notable advance is the addition of targeted therapy to lung cancer treatment. Targeted agents such as erlotinib and bevacizumab have demonstrated clinical benefits and gained Food and Drug Administration approval for lung cancer. More agents targeting various signaling pathways critical to lung cancer are at different stages of development. Along with the effort of new targeted drug discovery, biomarkers such as epidermal growth factor receptor and anaplastic lymphoma kinase mutations have proven useful for patient selection, and more predictive biomarkers have been actively evaluated in non-small cell lung cancer. The paradigm of lung cancer treatment has shifted towards biomarker-based personalized medicine.

MUC4 mucin-induced epithelial to mesenchymal transition: a novel mechanism for metastasis of human ovarian cancer cells

The acquisition of invasiveness in ovarian cancer (OC) is accompanied by the process of epithelial-to-mesenchymal transition (EMT). The MUC4 mucin is overexpressed in ovarian tumors and has a role in the invasiveness of OC cells. The present study was aimed at evaluating the potential involvement of MUC4 in the metastasis of OC cells by inducing EMT. Ectopic overexpression of MUC4 in OC cells (SKOV3-MUC4) resulted in morphological alterations along with a decreased expression of epithelial markers (E-cadherin and cytokeratin (CK)-18) and an increased expression of mesenchymal markers (N-cadherin and vimentin) compared with the control cells (SKOV3-vector). Also, pro-EMT transcription factors TWIST1, TWIST2 and SNAIL showed an upregulation in SKOV3-MUC4 cells. We further investigated the pathways upstream of N-cadherin, such as focal adhesion kinase (FAK), MKK7, JNK1/2 and c-Jun, which were also activated in the SKOV3-MUC4 cells compared with SKOV3-vector cells. Inhibition of phospho-FAK (pFAK) and pJNK1/2 decreased N-cadherin expression in the MUC4-overexpressing cells, which further led to a significant decrease in cellular motility. Knockdown of N-cadherin decreased the activation of extracellular signal-regulated kinase-1/2 (ERK1/2), AKT and matrix metalloproteinase 9 (MMP9), and inhibited the motility in the SKOV3-MUC4 cells. Upon in vivo tumorigenesis and metastasis analysis, the SKOV3-MUC4 cells produced significantly larger tumors and demonstrated a higher incidence of metastasis to distance organs (peritoneal wall, colon, intestine, stomach, lymph nodes, liver and diaphragm). Taken together, our study reveals a novel role for MUC4 in inducing EMT through the upregulation of N-cadherin and promoting metastasis of OC cells.

A phase II study of bevacizumab, oxaliplatin, and docetaxel in locally advanced and metastatic gastric and gastroesophageal junction cancers

BACKGROUND

Bevacizumab has demonstrated antitumor activity in multiple diseases. This phase II study was undertaken to determine the effects of adding bevacizumab to a regimen of docetaxel and oxaliplatin in patients with advanced adenocarcinoma of the stomach or gastroesophageal junction.

PATIENTS AND METHODS

Previously untreated patients with locally advanced or metastatic disease and a performance status (PS) of 0-1 were eligible for this study. Patients received bevacizumab at 7.5 mg/kg, docetaxel at 70 mg/m(2), and oxaliplatin at 75 mg/m(2) administered on day 1 of a 21-day cycle. The primary end point of the study was progression-free survival (PFS).

RESULTS

A total of 38 eligible patients (median age 57 years, 45% gastric, 55% PS 0) were enrolled on to the study. Median PFS was 6.6 months [95% confidence interval (CI) 4.4-10.5] and median survival 11.1 months (95% CI 8.2-15.3). Complete responses were documented in 2 (5%) patients, partial responses in 14 (37%), and stable disease in 14 (37%). No treatment-related deaths were observed. The most commonly reported grade 3-4 toxicity was neutropenia (34%), and gastrointestinal perforation occurred in three patients (8%).

CONCLUSION

The combination of bevacizumab, docetaxel, and oxaliplatin has promising activity for further evaluation in randomized trials.

Glycosylated VCAM-1 isoforms revealed in 2D western blots of HUVECs treated with tumoral soluble factors of breast cancer cells

Background

Several common aspects of endothelial phenotype, such as the expression of cell adhesion molecules, are shared between metastasis and inflammation. Here, we analyzed VCAM-1 variants as biological markers of these two types of endothelial cell activation. With the combination of 2-DE and western blot techniques and the aid of tunicamycin, we analyzed N-glycosylation variants of VCAM-1 in primary human endothelial cells stimulated with either TNF or tumoral soluble factors (TSF's) derived from the human breast cancer cell line ZR75.30.

Results

Treatments induced a pro-adhesive endothelial phenotype. 2D western blots analysis of cells subjected to both treatments revealed the expression of the two known VCAM-1 isoforms and of previously unknown isoforms. In particular TSFZR75.30 induced an isoform with a relative molecular mass (Mr) and isoelectric point (pI) of 75-77 kDa and 5.0, respectively.

Conclusion

The unknown isoforms of VCAM-1 that were found to be overexpressed after treatment with TSF's compared with TNF, could serve as biomarkers to discriminate between inflammation and metastasis. 2D western blots revealed three new VCAM-1 isoforms expressed in primary human endothelial cells in response to TSF stimulation. Each of these isoforms varies in Mr and pI and could be the result of differential glycosylation states.

Morphometric analysis of CD34-positive vessels in salivary gland adenoid cystic and mucoepidermoid carcinomas

BACKGROUND

Carcinomas of the salivary glands are uncommon and morphologically a diverse group of malignancies. To evaluate the prognostic value of CD34 immunostaining of the vessels in adenoid cystic carcinoma (AdCC) and mucoepidermoid carcinoma (MEC), an automated image analysis method was used.

METHOD

In a nationwide study, covering salivary gland cancer (SGC) patients in Finland 1991-1996, 37 AdCC and 18 MEC patients (M 25, F 30, age 25-90, mean 63) were included. In addition to clinical characteristics the size, shape, staining intensity and vessel density in CD34 immunostained histologic samples were measured.

RESULTS

Altogether 4433 vessels were measured from AdCC and 2615 from MEC tumor. Of the total tumor vessels measured, 2651 were from patients who deceased with disease (Group I) and 4397 were from specimens derived from those who did not die of disease (Group II) during the 10-year follow-up. The staining intensity was significantly higher in MEC than in AdCC tumor (P = 0.0005). In MEC, the Group I patients had a higher staining intensity among high-grade patients compared with patients with low grade disease, whereas the tumors in Group II had a lower staining intensity among the high-grade compared with the low grade tumors (P = 0.018). A higher vessel density was found in patients with MEC in group II compared with group I (P = 0.017).

CONCLUSIONS

The staining intensity of CD34 positive vessels in MEC was higher than in AdCC. In MEC, higher staining intensity of vessels in high-grade tumors and lower vessel density in all MEC patients, predicted poor survival.

Elevating blood pressure as a strategy to increase tumor-targeted delivery of macromolecular drug SMANCS: cases of advanced solid tumors

The purpose of this study is to evaluate the improved method of arterial infusion therapy of SMANCS (SX) with lipiodol under the angiotensin-induced hypertensive state for various difficult-to-treat solid tumors. Most patients were unresectable with no other therapeutic options, recurrence after resection, or patients do not respond to common treatments. The new method utilizes angiotensin II (AT) to induce hypertension (e.g. approximately 15-30 mmHg above norm) for 15-20 min. This method was successfully applied to metastatic liver cancer, cholangiocarcinoma, massive renal cell carcinoma, pancreatic and other abdominal solid cancers. This AT-induced hypertension resulted in remarkably enhanced tumor delivery accompanied by improved therapeutic response, and a shorter time to achieve 50% regression of tumor size with least toxicity. We demonstrated clinically herein improved therapy for various advanced solid tumors with SX by elevating the tumor blood flow selectively. This is the first clinical proof that modulations of vascular pathophysiology can uniquely accomplish enhanced tumor selective delivery of polymeric drugs and thus yielded better clinical outcome.

Angiogenesis in salivary carcinomas with and without myoepithelial differentiation

To investigate whether salivary carcinomas with and without myoepithelial differentiation could present differences regarding degree of angiogenesis, we compared tumor vascularization between adenoid cystic (31 cases) and epithelial-myoepithelial carcinomas (14) versus mucoepidermoid (37) carcinoma. The expression of peroxiredoxin I was also studied to verify the potential relationship between cellular metabolism and microvascular density. Microvascular density for CD34 and CD105 were significantly lower in carcinomas with myoepithelial differentiation. However, no correlation was found between degree of angiogenesis and amounts of myoepithelial cells. High-grade peroxiredoxin I expression was found in 73.7% of mucoepidermoid carcinomas, whereas 85.1% of carcinomas with myoepithelial differentiation presented low-grade expression. In conclusion, carcinomas with myoepithelial differentiation, regardless of the amounts of myoepithelial cells, are associated to a significantly lower vascular density. The reasons for this lower angiogenic activity remain to be determined but could be related to metabolic characteristics of the cancer cells.

Enhanced expression of Rab27A gene by breast cancer cells promoting invasiveness and the metastasis potential by secretion of insulin-like growth factor-II

In addition to the functions of transporting melanosome in melanocytes and releasing contents of lytic granules in CTLs, Rab27A was recently shown to be involved in exocytosis of insulin and chromaffin granules in endocrine cells; it was also reported to be expressed in an exceptionally broad range of specialized secretory cells. As autocrine and paracrine cytokines are essential for invasion and metastasis in some solid tumors, blocking them may be an effective strategy to prevent tumor dissemination. In the present study, we show that Rab27A is associated with invasive and metastatic potentials of human breast cancer cells. The overexpression of Rab27A protein redistributed the cell cycle and increased the invasive and metastatic abilities in breast cancer cells both in vitro and in vivo. We also certified that Rab27A conferred the invasive and metastatic phenotypes on breast cancer cells by promoting the secretion of insulin-like growth factor-II (IGF-II), which regulates the expression of p16, vascular endothelial growth factor, matrix metalloproteinase-9, cathepsin D, cyclin D1, and urokinase-type plasminogen activator. These data provide functional evidence that Rab27A acts as a novel mediator of invasion and metastasis promotion in human breast cancer cells, at least in part, through regulating the secretion of IGF-II, suggesting that synergistic suppression of Rab27A and IGF-II activities holds a promise for preventing breast cancer invasion and metastasis.

Interaction between the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF) pathways: a rational approach for multi-target anticancer therapy

Over the last decade, the concept of targeted biological therapy for the treatment of cancer has emerged. However, a better understanding of these targets and their role in tumor cells and in the surrounding stromal cells is required. Two interesting biological targets are the epidermal growth factor receptor (EGFR) and the vascular endothelia growth factor (VEGF) and its receptors. A number of agents that target these pathways have been described. Many of these are currently in clinical trials and a few have recently been approved by the regulatory authorities in USA and in the European Union. The molecular pathways involved in the proliferation of cancer cells and in tumor-related angiogenesis are very complex and the interference with only a single step of these pathways may often reveal an insufficient therapeutic approach. Moreover, cancer cells have an inherent ability to harness different growth factor signaling pathways for growth advantage and cell survival, a process that may even be facilitated by the use of selective targeted agents. Because of these escape mechanisms, monotherapy with selective targeted agents is unlikely to be a fully effective cancer treatment. For these reasons, targeting different pathways is an attractive and effective therapeutic strategy with a strong rationale for investigating this approach in the clinic. This review focuses on the preclinical rationale of combining targeted agents such as EGFR and VEGF inhibitors in the treatment of cancer and on the clinical trials that have emerged from these studies.

The role of bevacizumab in the treatment of non-small cell lung cancer: current indications and future developments

The majority of non-small cell lung cancer (NSCLC) patients present with advanced disease, and despite the improvement in efficacy and safety outcomes with platinum-based chemotherapy, this standard cytotoxic approach has reached a therapeutic plateau, with the prognosis for this clinical condition remaining poor. Advances in the knowledge of tumor biology and mechanisms of oncogenesis have granted the singling out of several molecular targets for NSCLC treatment. Bevacizumab, an anti-growth factor vascular endothelial growth factor (VEGF) monoclonal antibody, is the antiangiogenic agent at the most advanced stage of development in the treatment of solid tumors and also in NSCLC treatment. Bevacizumab, combined with platinum-based chemotherapy, has been demonstrated to improve efficacy outcomes over chemotherapy alone in the treatment of nonsquamous advanced NSCLC in two phase III randomized trials. These represent the first evidence of improvement in treatment outcomes of chemotherapy with targeted therapies in the first-line treatment of advanced NSCLC. Future clinical developments of bevacizumab in NSCLC treatment will include the combination of this agent with other targeted therapies in advanced disease (especially with erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor) and the integration of this agent into combined modality approaches for the treatment of early-stage and locally advanced disease.

Multiphase contrast-enhanced CT imaging in hepatocellular carcinoma correlation with immunohistochemical angiogenic activities

RATIONALE AND OBJECTIVES

To evaluate the correlation between enhancement parameters of multiphase contrast-enhanced computed tomography (CT) and immunohistochemical activities of vascular endothelial growth factor (VEGF), VEGF receptors, and CD34 in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Twenty-seven patients underwent curative resection for HCC with no preoperative treatment. We defined several CT enhancement parameters by measuring attenuation values of tumor, liver parenchyma, and aorta. The stored tissue blocks were assayed for immunohistochemical activities of VEGF, two VEGF receptors (Flt-1, Flk-1), and CD34, which were correlated with the enhancement parameters of multiphase contrast-enhanced CT.

RESULTS

The VEGF activities in HCC showed moderate positive correlation with phase difference in portal phase, delayed enhancement (DE), tumor-blood ratio, blood pool index, and tumor-parenchyma ratio in arterial phase. The Flk-1 activities in HCC showed moderate positive correlation only with DE. CD34 activity in HCC showed positive correlation with most of the CT parameters except for DE.

CONCLUSION

Our study showed that several CT enhancement parameters representing mainly delayed enhancement features were well correlated with VEGF activity in HCC, and might be valuable indicators for assessing angiogenic activity in HCC.

Morphometric analysis using automated image analysis of CD34-positive vessels in salivary gland acinic cell carcinoma

CONCLUSIONS

In computer-assisted analysis of acinic cell cancer (ACC) morphological characteristics of CD34 immunoreactivity were detected. Bigger vessel size, vessel irregularity, and lower intensity of CD34-positive vessel staining may indicate unfavorable prognosis.

OBJECTIVES

Salivary gland cancer (SGC) is a morphologically diverse group of malignancies, the most common histological types being mucoepidermoid, adenoid cystic and ACC, which has the most favorable prognosis of the three. The aim of this research was to study the applicability of automated image analysis as prognostic criteria in ACC.

PATIENTS AND METHODS

In a nationwide study covering SGC patients in Finland during 1991-1996, 34 patients with ACC (15 males, 19 females, aged 19-95 years, mean 55 years) were included. Parameters were measured from CD34-stained samples.

RESULTS

In all, 10 385 vessels were measured, of which 9873 were from specimens from patients who were alive 5 years after treatment (n=32, group I) and 512 were from patients who died of disease (n=2, group II). The following results were found in group II versus group I: mean vessel size 469 microm vs 272 microm (p=0.024); vessel irregularity 28.3 microm vs 22.3 microm (p<0.001); CD34 staining intensity 0.555 microm vs 0.584 microm (p=0.024).

Bevacizumab in the treatment of non-small-cell lung cancer

Lung cancer is the leading cause of cancer death in the United States. The majority of patients present with advanced disease, and treatment with standard cytotoxic chemotherapy improves survival and quality of life in patients with a preserved functional status. However, the prognosis is poor with the majority of patients dying in less than a year. Treatment with standard cytotoxic chemotherapy has reached a therapeutic plateau, and new therapeutic approaches have investigated therapies that target the specific molecular pathways involved in carcinogenesis and angiogenesis. The most promising strategy for inhibiting angiogenesis involves agents that either target the proangiogenesis growth factor, vascular endothelial growth factor A (VEGF) by preventing binding to the receptor or inhibiting the downstream signaling of the vascular endothelial growth factor receptor. The only therapeutic agent approved for the treatment of lung cancer is bevacizumab, a monoclonal antibody that binds to VEGF. A recent phase III trial revealed a statistically significant improvement in response rate, progression free and overall survival with combination of bevacizumab with chemotherapy over chemotherapy alone. Attempts to identify surrogate markers of antiangiogenesis activity are currently ongoing, and may assist in the selection of patients for antiangiogenesis therapy and the development of this class of agents.

TTYH2, a human homologue of the Drosophila melanogaster gene tweety, is up-regulated in colon carcinoma and involved in cell proliferation and cell aggregation

AIM: To investigate the expression patterns of TTYH2 in the human colon cancer and colon cancer cell lines and to evaluate the inhibitory effect of small interfering RNA (siRNA) on the expression of TTYH2 in colon cancer cell lines.

METHODS: We investigated the expression patterns of TTYH2 in colon cancer, adjacent non-tumorous colon mucosa, and cancer cell lines (DLD-1, caco-2, and Lovo) by RT-PCR. Furthermore, a siRNA plasmid expression vector against TTYH2 was constructed and transfected into DLD-1 and Caco-2 with Lipofectamine^TM 2000. The down regulation of TTYH2 expression was detected by RT-PCR and the role of siRNA in inducing cell proliferation and cell aggregation was evaluated by MTT and aggregation assay.

RESULTS: TTYH2 gene expression in colon cancer tissue was significantly up-regulated compared with normal colonic mucosa (1.23 ± 0.404 vs 0.655 ± 0.373, P = 0.0103). Colon cancer derived cell lines including DLD-1, Caco-2, and Lovo also expressed high levels of TTYH2. In contrast, transfection with siRNA-TTYH2 significantly inhibited both proliferation and scattering of these cancer cell lines.

CONCLUSION: The present work demonstrates, for the first time, that the TTYH2 gene expression is significantly up-regulated in colon cancer. The TTYH2 gene may play an important role in regulating both proliferating and metastatic potentials of colorectal cancer.

AG-013736, a novel inhibitor of VEGF receptor tyrosine kinases, inhibits breast cancer growth and decreases vascular permeability as detected by dynamic contrast-enhanced magnetic resonance imaging

Dynamic contrast-enhanced MRI (DCE-MRI) was used to noninvasively evaluate the effects of AG-03736, a novel inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, on tumor microvasculature in a breast cancer model. First, a dose response study was undertaken to determine the responsiveness of the BT474 human breast cancer xenograft to AG-013736. Then, DCE-MRI was used to study the effects of a 7-day treatment regimen on tumor growth and microvasculature. Two DCE-MRI protocols were evaluated: (1) a high molecular weight (MW) contrast agent (albumin-(GdDTPA)(30)) with pharmacokinetic analysis of the contrast uptake curve and (2) a low MW contrast agent (GdDTPA) with a clinically utilized empirical parametric analysis of the contrast uptake curve, the signal enhancement ratio (SER). AG-013736 significantly inhibited growth of breast tumors in vivo at all doses studied (10-100 mg/kg) and disrupted tumor microvasculature as assessed by DCE-MRI. Tumor endothelial transfer constant (K(ps)) measured with albumin-(GdDTPA)(30) decreased from 0.034+/-0.005 to 0.003+/-0.001 ml min(-1) 100 ml(-1) tissue (P<.0022) posttreatment. No treatment-related change in tumor fractional plasma volume (fPV) was detected. Similarly, in the group of mice studied with GdDTPA DCE-MRI, AG-013736-induced decreases in tumor SER measures were observed. Additionally, our data suggest that 3D MRI-based volume measurements are more sensitive than caliper measurements for detecting small changes in tumor volume. Histological staining revealed decreases in tumor cellularity and microvessel density with treatment. These data demonstrate that both high and low MW DCE-MRI protocols can detect AG-013736-induced changes in tumor microvasculature. Furthermore, the correlative relationship between microvasculature changes and tumor growth inhibition supports DCE-MRI methods as a biomarker of VEGF receptor target inhibition with potential clinical utility.

Enhanced expression of LKB1 in breast cancer cells attenuates angiogenesis, invasion, and metastatic potential

LKB1 (also known as STK11) is a recently identified tumor suppressor gene whose mutation can lead to Peutz-Jeghers syndrome, which is characterized by gastrointestinal polyps and cancers of different organ systems. Approximately 30% of sporadic breast cancer samples express low levels of LKB1. This suggests that the LKB1 gene may be related to the tumorigenesis of breast cancer. We reintroduced LKB1 into MDA-MB-435 breast cancer cells that lack the LKB1 gene to investigate how overexpression of LKB1 affects tumor invasiveness and metastasis. Overexpression of the LKB1 protein in breast cancer cells resulted in significant inhibition of in vitro invasion. In vivo, LKB1 expression reduced tumor growth in the mammary fat pad, microvessel density, and lung metastasis. LKB1 overexpression was associated with down-regulation of matrix metalloproteinase-2, matrix metalloproteinase-9, vascular endothelial growth factor, and basic fibroblast growth factor mRNA and protein levels. Overexpression of the LKB1 protein in human breast cancer is significantly associated with a decrease in microvessel density. Our results indicate that LKB1 plays a negative regulatory role in human breast cancer, a finding that may lead to a new therapeutic strategy.

Assessment of Bone Marrow Angiogenesis in Patients with Acute Myeloid Leukemia by Using Contrast-enhanced MR Imaging with Clinically Approved Iron Oxides: Initial Experience

PURPOSE

To prospectively assess bone marrow (BM) angiogenesis in patients with acute myeloid leukemia (AML) by using iron oxide-enhanced magnetic resonance (MR) imaging.

MATERIALS AND METHODS

The study was institutional ethics committee approved. Informed signed consent was obtained from each study participant. The requirement for informed consent for use of data from a reference database was waived. Eleven patients (seven women, four men; mean age, 53 years+/-4.40 [standard deviation]) with an initial diagnosis of AML were enrolled in the study and underwent T2*-weighted two-echo echo-planar MR imaging of the pelvis before and after intravenous injection of a clinically approved iron oxide blood-pool contrast agent. Six healthy control subjects (one woman, five men; mean age, 35 years+/-2.31) were examined with the same MR protocol. The iron oxide-induced change in R2* relaxation rate (DeltaR2*) was calculated, and the vascular volume fraction (VVF) of the BM was derived by dividing the DeltaR2* of the BM by the DeltaR2* of the muscle. Parametric DeltaR2* maps were calculated to visualize vessel distribution. Patients underwent BM biopsy for correlative determination of microvessel density (MVD) and vascular endothelial growth factor (VEGF). Differences in DeltaR2*, VVF, VEGF, and MVD were compared by using the Wilcoxon rank sum test.

RESULTS

DeltaR2* maps showed prominent areas of highly vascularized BM in the patients with AML, whereas the control subjects had moderately vascularized BM with homogeneous vessel distribution. Quantitative analysis revealed VVF values to be significantly higher in patients with AML than in control subjects: The mean VVF in the pelvis was 9.18%+/-1.54 for patients versus 3.91%+/-0.61 for control subjects (P=.010). In accordance with MR results, MVD (P=.009) and VEGF expression (P=.017) were significantly elevated in the AML group compared with values in the control group.

CONCLUSION

Iron oxide-enhanced MR imaging enables assessment of BM angiogenesis in patients with AML.

Gene expression profile analysis of an isogenic tumour metastasis model reveals a functional role for oncogene AF1Q in breast cancer metastasis

To study the molecular mechanisms underlying breast cancer metastasis, gene expression profile analysis was performed on two well-established breast cancer cell lines with high and low metastatic potentials: MDA-MB-435HM and MDA-MB-435LM. The analysis was conducted using cDNA microarrays containing 8000 genes. Of 60 differentially expressed genes, ALL1-fused gene from chromosome 1q (AF1Q), a putative oncogene not described previously in breast cancer, was identified and found to be over-expressed in MDA-MB-435HM cells compared with MDA-MB-435LM cells. The results indicate that AF1Q may play an important role in breast cancer metastasis. To test this hypothesis, we generated an AF1Q high-expression cell line by stable transfection of AF1Q cDNA into MDA-MB-435LM cells. Results showed that over-expression of AF1Q led to a marked increase in the invasive and metastatic potential of MDA-MB-435LM cells in vitro and in vivo, accompanied by the up-regulation of matrix metalloproteinase-2 (MMP-2), MMP-9, transcription factor Ets-1, and RhoC expression in both mRNA and protein levels. Consistent with this observation, reduced AF1Q expression in MDA-MB-435HM cells by small interfering RNA (siRNA) resulted in a significant decrease in the invasive potential of MDA-MB-435HM cells in vitro and in the protein expression of MMP-2, MMP-9, Ets-1, and RhoC, compared with either parental or non-silencing control cells. These data provide functional evidence that oncogene AF1Q may be a novel mediator of metastasis promotion in human breast cancer through regulation of the MMP pathway and RhoC expression.

New antiangiogenetic agents and non-small cell lung cancer

New blood vessel formation, known as angiogenesis is a fundamental event in the process of tumor growth and metastatic dissemination. Due to its central role in tumor angiogenesis, the vascular endothelial growth factor (VEGF) and its receptor have been a major focus of basic research and drug development in the field of oncology, including the treatment of non-small cell lung cancer (NSCLC). Approaches targeting VEGF include monoclonal antibodies and vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs). Bevacizumab (Avastin) is an anti-VEGF recombinant humanized monoclonal antibody. A very recent randomized phase III trial demonstrated a statistically significant advantage in median survival favouring the combination of bevacizumab plus chemotherapy versus chemotherapy alone in the treatment of advanced non-squamous NSCLC. This study represents the first evidence of superior efficacy of targeted therapy combined with chemotherapy over chemotherapy alone in the treatment of NSCLC. ZD6474 is an orally bioavailable inhibitor of VEGFR-2 tyrosine kinase. First evidences of antitumor activity and its excellent toxicity profile make it a promising targeted agent for the treatment of NSCLC. A recent phase I/II study examined the combination of Epidermal Growth Factor Receptor (EGFR)-TKI erlotinib and bevacizumab in patients with non-squamous stage IIIB/IV NSCLC. Data on antitumor activity of this combination have to be considered very promising. Clinical trials of multiple targeted therapy may represent the second generation studies in the treatment of NSCLC.

Influence of Timing of Initiation of Adjuvant Chemotherapy Over Survival in Breast Cancer: A Negative Outcome Study by the Spanish Breast Cancer Research Group (GEICAM)

PURPOSE

This retrospective trial evaluates whether the timing of initiation of the adjuvant chemotherapy has any influence over survival in early-stage breast cancer.

PATIENTS AND METHODS

A total of 2782 patients from El Alamo project (from 1990 to 1997; n = 15,400) were selected with stages I-III, surgery and adjuvant chemotherapy. Data were gathered about prognostic factors such as age, tumor size, vessel permeation (vascular or lymphatic), histological grade, and number of involved nodes, hormonal receptor status and administration of hormone therapy. The time interval between surgery and initiation of chemotherapy, and dates of relapse, second primary breast tumor and death were recorded. Patients were assigned in four groups according to the surgery-chemotherapy interval: <3 weeks (group A), 3-6 weeks (group B), 6-9 weeks (group C) and >9 weeks (group D).

RESULTS

There were no differences in disease-free survival (DFS), nor in 5-year overall survival (OS), according to the timing of initiation of adjuvant chemotherapy. Cox proportional hazards model was used to adjust analysis for known prognostic factors but the effect of surgery-chemotherapy interval remained non-significant. The variable timing of initiation of adjuvant chemotherapy has also been assessed as a continuous variable and no differences have been detected.

CONCLUSION

The optimum time of initiation of adjuvant chemotherapy in early stages of breast cancer is unknown. The delay in the initiation of adjuvant chemotherapy has no influence over survival in the analyzed time intervals. Retrospective analysis like this one with enough statistical power would be necessary to detect differences among groups.

Antiangiogenic drugs in non-small cell lung cancer treatment

PURPOSE OF REVIEW

A promising therapeutic target is the vascular endothelial growth factor pathway - a key mediator of tumor angiogenesis - which is important in tumor growth, invasion, and metastasis. This review focuses on the available clinical data on drugs targeting the vascular endothelial growth factor - vascular endothelial growth factor receptor pathway in the treatment of non-small cell lung cancer.

RECENT FINDINGS

The therapeutic value of inhibiting the vascular endothelial growth factor pathway has been demonstrated by using drugs that prevent vascular endothelial growth factor receptor binding and by using drugs that inhibit receptor activation. Two antiangiogenic drugs exemplify these mechanisms: bevacizumab (Avastin; Genentech, South San Francisco, California, USA), a humanized monoclonal antibody that acts by binding and neutralizing vascular endothelial growth factor; and ZD6474 (Zactima; AstraZeneca, Macclesfield, UK), a small-molecule inhibitor of vascular growth factor receptor and epidermal growth factor receptor tyrosine kinase activity. Recently, the first results of a large, phase III randomized clinical trial of bevacizumab in combination with platinum-based doublet chemotherapy have been reported in patients with nonsquamous non-small cell lung cancer.

SUMMARY

The inhibition of tumor angiogenesis is a key therapeutic strategy that holds great promise for the advancement of metastatic lung cancer therapy. The combination of bevacizumab and conventional chemotherapy could offer a new therapeutic option in selected non-small cell lung cancer histotypes.

Correlations of oral tongue cancer invasion with matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) expression

BACKGROUND AND OBJECTIVES

In oral tongue cancer, the degree of tumor invasion has a significant effect on the prognosis. We hypothesized that the destruction of extracellular matrix and neovascularization are related to tumor infiltration mechanism. By studying the tissues of early stage oral tongue cancer patients, we are intending to clarify the invasion-related factors.

MATERIALS AND METHODS

To demonstrate the invasion process in early T-stage oral tongue cancer, the expressions of extracellular matrix destruction-related molecules (MMP-2, MMP-9) and neovascularization-related molecule (VEGF) were observed by immunohistochemical study. Also, staining of CD31 was done for quantification of neovascularization. We analyzed relationship between expression of each substances and tumor invasion depth, tumor free survival rates, and cervical lymph node metastasis rate.

RESULTS

The expression rates of MMP-2, MMP-9, VEGF in 38 early oral cancer patients were 52.6%, 78.9%, and 52.6%, respectively. Significant correlation was found between the VEGF expression and microvessel density showed by CD31 immunohistochemical staining (P < 0.001). VEGF expressions were significantly related with tumor invasion depth (P = 0.002). The tumor-free survival rate of those patients with VEGF-positive tumors was significantly poorer than in those with VEGF-negative tumors (P = 0.019).

CONCLUSIONS

These results indicate that VEGF is a useful marker for predicting the tumor invasion in patients with early tongue cancer.

Invasion and metastasis markers in cancers

Over 90% of all adults human cancers are of epithelial origin comprising mainly of skin and aero-digestive tract cancers. A significant proportion of our discipline's workload consists of management of these cancers. This review article is to provide clinicians with a summary of the current research findings in invasion and metastasis of epithelial cancers and the translation of some of this information to clinical use particularly related to skin and head and neck cancers (HNSCC). Metastasis is the leading cause of death in cancer patients. Although surgical resection of isolated metastases is beneficial for some patients, the overall efficacy of surgery, chemotherapy or radiotherapy is limited. Clearly, with today's advances in surgery a majority of these primary cancers are resectable and a cure attainable if surgeons could control or inhibit metastasis.

Angiogenesis and lung cancer: prognostic and therapeutic implications

Lung cancer is the most common cause of cancer death worldwide, with most patients dying with metastatic disease. The prognosis for the majority of patients remains poor. It is evident that advances in the treatment of this and other tumor types will require new approaches, and recent research has focused on molecular-targeted therapies. A key therapeutic strategy is inhibition of specific processes essential for tumor vascular development (a concept known to be beneficial in colorectal cancer) and a range of such antiangiogenic agents are currently in development. The most promising of these target the proangiogenic vascular endothelial growth factor (VEGF), either by preventing VEGF-receptor binding or inhibiting downstream receptor signaling. However, other more direct approaches against tumor vasculature are also in development. Since antiangiogenic agents often exert an indirect, cytostatic effect, many are being evaluated in combination with conventional chemotherapies in order to optimize the anticancer effects of both strategies. Additionally, the combination of several antiangiogenic agents is also being explored. This has become possible given the large number of agents currently available. As part of this evaluation process, the assessment of surrogate markers of target inhibition and treatment effect is ongoing in the hope of identifying reliable surrogate markers to aid the development of this new generation of anticancer agents.