Tumour angiogenesis: vascular growth and survival

The multiple roles of autophagy in uveal melanoma and the microenvironment

PURPOSE

Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults, and effective clinical treatment strategies are still lacking. Autophagy is a lysosome-dependent degradation system that can encapsulate abnormal proteins, damaged organelles. However, dysfunctional autophagy has multiple types and plays a complex role in tumorigenicity depending on many factors, such as tumor stage, microenvironment, signaling pathway activation, and application of autophagic drugs.

METHODS

A systematic review of the literature was conducted to analyze the role of autophagy in UM, as well as describing the development of autophagic drugs and the link between autophagy and the tumor microenvironment.

RESULTS

In this review, we summarize current research advances regarding the types of autophagy, the mechanisms of autophagy, the application of autophagy inhibitors or agonists, autophagy and the tumor microenvironment. Finally, we also discuss the relationship between autophagy and UM.

CONCLUSION

Understanding the molecular mechanisms of how autophagy differentially affects tumor progression may help to design better therapeutic regimens to prevent and treat UM.

Thoracic Applications of Spectral CT Scan

TOPIC IMPORTANCE

Thoracic imaging with CT scan has become an essential component in the evaluation of respiratory and thoracic diseases. Providers have historically used conventional single-energy CT; however, prevalence of dual-energy CT (DECT) is increasing, and as such, it is important for thoracic physicians to recognize the utility and limitations of this technology.

REVIEW FINDINGS

The technical aspects of DECT are presented, and practical approaches to using DECT are provided. Imaging at multiple energy spectra allows for postprocessing of the data and the possibility of creating multiple distinct image reconstructions based on the clinical question being asked. The data regarding utility of DECT in pulmonary vascular disorders, ventilatory defects, and thoracic oncology are presented. A pictorial essay is provided to give examples of the strengths associated with DECT.

SUMMARY

DECT has been most heavily studied in chronic thromboembolic pulmonary hypertension; however, it is increasingly being used across a wide spectrum of thoracic diseases. DECT combines morphologic and functional assessments in a single imaging acquisition, providing clinicians with a powerful diagnostic tool. Its role in the evaluation and treatment of thoracic diseases will likely continue to expand in the coming years as clinicians become more experienced with the technology.

Applications of Contrast-Enhanced Ultrasound in Splenic Studies of Dogs and Cats

Simple Summary

Contrast-enhanced ultrasound (CEUS) is a noninvasive imaging technique that has become a reliable tool for identifying and monitoring lesions in both human and animals. In the last decade, its use in veterinary diagnostic imaging has gained increasing importance, and it can be reliable in everyday clinical practice. However, there is a lack of reviews describing existing CEUS results in the study of splenic lesions, which is of particular importance in dogs and cats. This information is important for validating its efficacy, to facilitate decision making related to sampling procedures and diagnosis, or even as a means to select CEUS as an alternative diagnostic tool in specific cases. Our goal was to review the existing studies of CEUS applications for splenic ultrasound studies in cats and dogs, present these results in a systematic manner, and combine this information into practical guidelines that can be used to help diagnosis and interpretation in both clinical cases and research.

Abstract

Contrast-enhanced ultrasound (CEUS) is an emerging technology in veterinary medicine involving the administration of intravenous contrast agents, and it is increasingly recognized for its high potential as a diagnostic imaging tool for small animals. This exam is easy and quick to perform, safe and reliable, and allows for the differentiation of lesions. It permits the identification of lesions that may require more invasive procedures, from those that can be safely dismissed to those that can be followed-up with ultrasound imaging. Although it has been extensively reviewed for use in human medicine, there is an overall lack of information about the application of this technique for cats and dogs, particularly in splenic studies, which can be particularly important for small animals. The present review describes and summarizes the CEUS applications used for splenic analysis in cats and dogs, providing a basic overview of CEUS technology with examples of common and uncommon features of focal splenic lesions. It also systematically gathers the results obtained for benign and malignant splenic lesions described in the literature, whilst providing guidelines for their interpretation. Furthermore, it presents the advantages of using CEUS for splenic analysis in cats and dogs and the main factors that may influence the quality of the imaging and the accuracy of the diagnosis. This type of knowledge can be used to provide a framework to help veterinarians make informed decisions regarding the use of this emerging technique for splenic lesions, guiding their interpretation of CEUS findings in the splenic ultrasounds of cats and dogs.

Vascular damage in tumors: a key player in stereotactic radiation therapy?

The use of stereotactic radiation therapy (SRT) for cancer treatment has grown in recent years, showing excellent results for some tumors. The greatly increased doses per fraction in SRT compared to conventional radiotherapy suggest a 'new biology' that determines treatment outcome. Proposed mechanisms include significant damage to tumor blood vessels and enhanced antitumor immune responses, which are also vasculature-dependent. These ideas are mostly based on the results of radiation studies in animal models because direct observations in humans are limited. However, even preclinical findings are somewhat incomplete and result in ambiguous conclusions. Current evidence of vasculature-related mechanisms of SRT is reviewed. Understanding them could result in better optimization of SRT alone or in combination with immune or other cancer therapies.

Application of two-dimensional difference gel electrophoresis to identify protein changes between center, margin, and adjacent non-tumor tissues obtained from non-small-cell lung cancer with adenocarcinoma or squamous cell carcinoma subtype

Lung cancer is responsible for the most cancer-related mortality worldwide and the mechanism of its development is poorly understood. Proteomics has become a powerful tool offering vital knowledge related to cancer development. Using a two-dimensional difference gel electrophoresis (2D-DIGE) approach, we sought to compare tissue samples from non-small-cell lung cancer (NSCLC) patients taken from the tumor center and tumor margin. Two subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were compared. Data are available via ProteomeXchange with identifier PXD032736 and PXD032962 for ADC and SCC, respectively. For ADC proteins, 26 significant canonical pathways were identified, including Rho signaling pathways, a semaphorin neuronal repulsive signaling pathway, and epithelial adherens junction signaling. For SCC proteins, nine significant canonical pathways were identified, including hypoxia-inducible factor-1α signaling, thyroid hormone biosynthesis, and phagosome maturation. Proteins differentiating the tumor center and tumor margin were linked to cancer invasion and progression, including cell migration, adhesion and invasion, cytoskeletal structure, protein folding, anaerobic metabolism, tumor angiogenesis, EMC transition, epithelial adherens junctions, and inflammatory responses. In conclusion, we identified several proteins that are important for the better characterization of tumor development and molecular specificity of both lung cancer subtypes. We also identified proteins that may be important as biomarkers and/or targets for anticancer therapy.

Dual-Energy CT Perfusion of Invasive Tumor Front in Non-Small Cell Lung Cancers

Background Active endothelial cell proliferation occurs at the tumor edge, known as the invading-tumor front. This study focused on perfusion analysis of non-small cell lung cancers. Purpose To analyze dual-phase, dual-energy CT perfusion according to the degree of tumor hypoxia. Materials and Methods This prospective study was performed 2016-2017. A two-phase dual-energy CT protocol was obtained for consecutive participants with operable non-small cell lung cancer. The first pass and delayed iodine concentration within the tumor and normalized iodine uptake, corresponding to the iodine concentration within the tumor normalized to iodine concentration within the aorta, were calculated for the entire tumor and within three peripheral layers automatically segmented (ie, 2-mm-thick concentric subvolumes). The expression of the membranous carbonic anhydrase (mCA) IX, a marker of tumor hypoxia, was assessed in tumor specimens. Comparative analyses according to the histologic subtypes, type of resected tumors, and mCA IX expression were performed. Results There were 33 mCA IX-positive tumors and 16 mCA IX-negative tumors. In the entire tumor, the mean normalized iodine uptake was higher on delayed than on first-pass acquisitions (0.35 ± 0.17 vs 0.13 ± 0.15, respectively; P < .001). A single layer, located at the edge of the tumor, showed higher values of the iodine concentration (median, 0.53 mg/mL vs 0.21 mg/mL, respectively; P = .03) and normalized iodine uptake (0.04 vs 0.02, respectively; P = .03) at first pass in mCA IX-positive versus mCA IX-negative tumors. Within this layer, a functional profile of neovascularization was found in 23 of 33 (70%) of mCA IX-positive tumors, and the median mCA IX score of these tumors was higher than in tumors with a nonfunctional profile of neovascularization (median mCA IX score, 20 vs 2, respectively; P = .03). Conclusion A two-phase dual-energy CT examination depicted higher perfusion between the tumor edge and lung parenchyma in hypoxic tumors. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Murphy and Ryan in this issue.

Integrins Within the Tumor Microenvironment: Biological Functions, Importance for Molecular Targeting, and Cancer Therapeutics Innovation

Many cellular functions important for solid tumor initiation and progression are mediated by members of the integrin family, a diverse family of cell attachment receptors. With recent studies emphasizing the role of the tumor microenvironment (TME) in tumor initiation and progression, it is not surprising that considerable attention is being paid to integrins. Several integrin antagonists are under clinical trials, with many demonstrating promising activity in patients with different cancers. A deeper knowledge of the functions of integrins within the TME is still required and might lead to better inhibitors being discovered. Integrin expression is commonly dysregulated in many tumors with integrins playing key roles in signaling as well as promotion of tumor cell invasion and migration. Integrins also play a major role in adhesion of circulating tumor cells to new sites and the resulting formation of secondary tumors. Furthermore, integrins have demonstrated the ability to promoting stem cell-like properties in tumor cells as well as drug resistance. Anti-integrin therapies rely heavily on the doses or concentrations used as these determine whether the drugs act as antagonists or as integrin agonists. This expert review offers the latest synthesis in terms of the current knowledge of integrins functions within the TME and as potential molecular targets for cancer therapeutics innovation.

The role of Notch ligand, Delta-like ligand 4 (DLL4), in cancer angiogenesis—implications for therapy

Background

It is generally accepted that angiogenesis is a complex and tightly regulated process characterized by the growth of blood vessels from existing vasculature. Activation of the Notch signalling pathway affects multiple aspects of vascular development. One of the components of the Notch signalling pathway, Delta-like ligand 4 (DLL4), has recently appeared as a critical regulator of tumour angiogenesis and thus as a promising therapeutic target.

Methods

This review article includes available data from peer-reviewed publications associated with the role of DLL4 in cancer angiogenesis. Searches were performed in PubMed, EMBASE, Google Scholar and Web of Science using the terms “tumour angiogenesis”, “DLL4”, “Notch signalling” and “anti-cancer therapy”.

Results

The survival curves of cancer patients revealed that the patients with high DLL4 expression levels had significantly shorter survival times than the patients with low DLL4 expression. Moreover, a positive correlation was also identified between DLL4 and VEGF receptorsʼ expression levels. It seems that inhibition of DLL4 may exert potent growth inhibitory effects on some tumours resistant to anti-VEGF therapies. A great number of blocking agents of DLL4/Notch signalling including anti-DLL4 antibodies, DNA vaccination, Notch antibodies and gamma-secretase inhibitors have been studied in preclinical tumour models.

Conclusion

DLL4 seems to be a promising target in anti-cancer therapy. Nevertheless, the careful evaluation of adverse effects on normal physiological processes in relation to therapeutic doses of anti-DLL4 drugs will be significant for advancement of DLL4 blocking agents in clinical oncology.

Diffusion kurtosis imaging and tumour microstructure for monitoring response to radiotherapy in human nasopharyngeal carcinoma xenografts

OBJECTIVE

To investigate the correlations and feasibility of diffusion kurtosis imaging (DKI) parameters and tumour histopathology after radiotherapy in human nasopharyngeal carcinoma (NPC) xenografts on nude mice.

MATERIALS AND METHODS

Seventy-two nude mice were used for the construction of CNE-1 (radio-insensitive) and CNE-2 (radio-sensitive) NPC xenograft models, followed by fraction irradiation at different doses of X-ray. The nude mice were randomly divided into six groups in each cell line models according to the dose of X-ray they have received and with six mice in each group. DKI scan was performed after radiation. DKI parameters, tumour histopathology and AQP-1 biomarkers were detected. One-way ANOVA and Pearson's correlation analysis were used in statistical analysis.

RESULTS

In CNE-1 and CNE-2 NPC xenografts, D values were increased (P < 0.01 and P < 0.001), while K values (P < 0.01 and P < 0.001) and tumour size (P < 0.001 and P < 0.001) were reduced during fraction irradiation. Additionally, cell density (CD) and AQP-1 expressions were decreased, and necrosis ratio (NR) was increased in CNE-2 xenografts after fraction irradiation (P < 0.001). The changes in D values were negatively correlated with tumour size (r = -0.856, P < 0.001), CD (r = -0.918, P < 0.001), AQP-1 mRNA (r = -0.856, P < 0.001) and protein (r = -0.381, P = 0.022) expressions while positively correlated with NR (r = 0.908, P < 0.001) in CNE-2 xenografts. The changes in K values were positively correlated with tumour size (r = 0.964, P < 0.001), CD (r = 0.888, P < 0.001), AQP-1 mRNA (r = 0.955, P < 0.001) and protein (r = 0.330, P = 0.049) expression levels while negatively correlated with NR (r = -0.930, P < 0.001). However, in CNE-1 xenografts, there were no correlation between DKI parameters and the expression of AQP-1.

CONCLUSION

Changes in D and K parameters after fractional irradiation are closely related with NPC cellular and pathological characteristics, especially size reduction and necrosis induction. These parameters exhibit potential abilities of monitoring the response to fractional irradiation in radio-sensitive NPC xenografts.

Tumor microenvironment, immune response and post-radiotherapy tumor clearance

Radiotherapy is the treatment of choice for many cancer patients. Residual tumor leads to local recurrence after a period of an equilibrium created between proliferating, quiescent and dying cancer cells. The tumor microenvironment is a main obstacle for the efficacy of radiotherapy, as impaired blood flow leads to hypoxia, acidity and reduced accessibility of radiosensitizers. Eradication of remnant disease is an intractable clinical quest. After more than a century of research, anti-tumor immunity has gained a dominant position in oncology research and therapy. Immune cells play a significant role in the eradication of tumors during and after the completion of radiotherapy. The tumor equilibrium reached in the irradiated tumor may shift towards cancer cell eradication if the immune response is appropriately modulated. In the modern immunotherapy era, clinical trials are urged to standardize immunotherapy schemes that could be safely applied to improve clearance of the post-radiotherapy remnant disease.

The enhanced T2 star weighted angiography (ESWAN) value for differentiating borderline from malignant epithelial ovarian tumors

PURPOSE

To investigate the potential of ESWAN in differentiating borderline epithelial ovarian tumors (BEOTs) from malignant epithelial ovarian tumors (MEOTs).

METHOD

Thirty-four patients with 37 lesions were enrolled, including 14 BEOTs and 23 MEOTs. The magnitude, phase, R₂* and T₂* maps were analyzed by two observers. The regions of interest were drawn along the boundaries of tumors on the slice with maximal solid area, according to fat suppression T₂WI and T₁WI. The consistency among the three measurements taken by two observers was tested by intra-class correlation coefficients. Agreement of average values measured by two observers was evaluated by Bland-Altman plots. All the data of BEOTs and MEOTs were compared using the independent-sample t test. The receiver operating characteristic curve was used to evaluate the diagnostic performance.

RESULTS

No statistical differences were observed in the magnitude and phase values between two tumor groups. The R₂* value of BEOTs was lower than that of MEOTs (P < 0.001), whereas the T₂* value of BEOTs was higher than that of MEOTs (P = 0.01). The area under the curve of R₂* values was 0.894 and the corresponding cutoff value was 7.50 Hz, with the sensitivity, specificity and accuracy of 85.7%, 82.6% and 86.5%, respectively. The AUC of T₂* values was 0.776 and the corresponding cutoff value was 143.73 ms with the sensitivity, specificity and accuracy of 71.4%, 82.6% and 78.4%, respectively.

CONCLUSIONS

R₂* and T₂* values can be used for quantificationally differentiating BEOTs from MEOTs and the R₂* has better diagnostic performance.

The survivin molecule as a double-edged sword in cellular physiologic and pathologic conditions and its role as a potential biomarker and therapeutic target in cancer

Survivin is a member of the family of apoptosis inhibitory proteins with increased expression level in most cancerous tissues. Evidence shows that survivin plays regulatory roles in proliferation or survival of normal adult cells, principally vascular endothelial cells, T lymphocytes, primitive hematopoietic cells, and polymorphonuclear neutrophils. Survivin antiapoptotic role is, directly and indirectly, related to caspase proteins and shows its role in cell division through the chromosomal passenger complex. Survivin contains many genetic polymorphisms that the role of some variations has been proven in several cancers. The -31G/C polymorphism is one of the most important survivin mutations which is located in the promoter region on a CDE/CHR motif. This polymorphism can upregulate the survivin messenger RNA. In addition, its allele C can increase the risk of cancers in 1.27-fold than allele G. Considering the fundamental role of survivin in different cancers, this protein could be considered as a new therapeutic target in cancer treatment. For this purpose, various strategies have been designed including the prevention of survivin expression through inhibition of mRNA translation using antagonistic molecules, inhibition of survivin gene function through small inhibitory molecules, gene therapy, and immunotherapy. In this study, we describe the structure, played roles in physiological and pathological states and genetic polymorphisms of survivin. Finally, the role of survivin as a potential target in cancer therapy given challenges ahead has been discussed.

Tumor autophagy is associated with survival outcomes in patients with resected non-small cell lung cancer

OBJECTIVES

LC3A protein is associated with autophagosomes, and LC3A immunohistochemistry (IHC) is used for the detection of autophagy activity. The aim of this study was to assess the prognostic value of LC3A expression in patients with resected non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We used tissue microarrays (TMAs) constructed from 116 resected stage IB-III NSCLC patients. Standard immunohistochemistry was performed on formalin-fixed paraffin-embedded tissue sections using antibody against LC3A autophagic potein. Stained slides were scanned by Olympus dotSlide Digital Virtual Microscopy System (Japan) and the LC3A staining was evaluated digitally. Groups were compared using the Mann Whitney U test, and correlations were assessed using Spearman's rank test. Survival was calculated using Kaplan-Meier analysis. Primary study endpoint was overall survival (OS), secondardy study endpoint disease-free survival (DFS). Cut-off optimization for LC3A prognostic value was performed using the "cut-off finder' 'software (Charite, Berlin, Germany). In addition, the Kaplan Meier plotter (KmPlot) was used to assess the relationship between LC3A mRNA expression and clinical outcome (OS and DFS) in patients with NSCLC.

RESULTS

From 116 patients, 88 tissue samples were available for final examination. No significant association was found between LC3A staining and other clinicopathological variables, including tumor grade, stage and histological subtype. A higher number of LC3A stone-like structures (SLSs) (>20), was significanly associated with poor OS (HR = 2.27, p = 0.011) and DFS (HR = 2.27, p = 0.003). A significant association between high LC3A mRNA and both a worse OS and worse DFS was found by KMPlot analysis in patients with stage I-III NSCLC.

CONSLUSION

This retrospective study suggests that SLSs as assessed by LC3A IHC as well as LC3A mRNA expression has a clinically relevant negative prognostic value in patients with resected NSCLC, and should be further investigated.

Does proximity to the subventricular zone and expression of CXCR-4 and nestin affect prognosis in high-grade glioma?

BACKGROUND

It is suspected that infiltration of stem cell areas with high-grade glioma (HGG) generates a population that compromises treatment results and survival. In this prospective study we set to assess the prognostic value of the proximity of the contrast-enhancing lesion (CEL) on MRI to the subventricular zone (SVZ) and the expression of CXCR4 and nestin as potential factors in the stem cell migration pathway.

METHOD

All patients diagnosed with high-grade glioma over a three-year period from a single institution were enrolled in this prospective study. Based on MRI preoperative findings, the patients were classified into 4 Groups (I-IV) according to the proximity of the CEL on MRI to the SVZ. Histological samples were assessed with immunohistochemistry for nestin and CXCR4. Classification into groups and the presence of nestin and CXCR4 were evaluated as predictive factors for overall (OS) and progression free survival (PFS).

RESULTS

Fourty patients were included in the study. In multivariate analysis, Groups II, III and IV predicted longer OS in comparison to group I (p = 0.01; p < 0.01; p < 0.01 respectively) and group III and IV predicted longer OS in comparison to group II (p < 0.01; p = 0.04 respectively). Group III predicted longer PFS than group I and II (p = 0.01; p < 0.01 respectively). The expression rates of CXCR-4 and nestin could not predict OS or PFS.

CONCLUSIONS

In our study the classification according to the proximity of the contrast enhancing part of the lesion and the SVZ proved to be prognostically significant for both OS and PFS. Presence of CXCR4 or nestin was not predictive for OS or PFS.

Correlation Between Microvessel Density and Morphological Features in Skin Squamous Cell Carcinoma

INTRODUCTION

Abnormal angiogenesis is described in tumor growth and it facilitates its metastatic spread. Tumors with high angiogenic activity belong to the category of aggressive tumors with poor prognosis for patients. The aim of this study was to determine the blood vessels density (BVD), i.e. neovascularization at the tumor invasive front in skin squamous cell carcinoma (SCC) in order to determine its possible role in the tumor progression, and to correlate it to the blood vessels density of healthy skin and with the prognostic parameters of the TNM classification: T status, depth of tumor invasion (DI) and tumor histological grade (G), which were also correlated between each other.

MATERIAL AND METHODS

The material consisted of surgical specimens obtained from 30 patients with skin SCC, who underwent surgery. Tissue samples were routinely processed by standard paraffin technique stained by Hematoxilin-Eosin and immunohistochemically with antibodies against smooth muscle actin (SMA) and CD34. The BVD in the invasive front of the neoplasms was correlated to the healthy skin, tumor status (pT), depth of invasion and grade of histological differentiation (pG).

RESULTS

The histological analysis has shown a high statistical difference in the density of blood vessels in SCC compared to the healthy skin and statistical difference in BVD in neoplasms with different depth of invasion and different grade of differentiation. The density of neovascularzation increased with the deeper invasion and the worse differentiation.

CONCLUSION

The increased vascularization at the invasive front of SCC with deeper invasion and worse differentiation has pointed out to its possible role in neoplasm progression.

The Role of Galectin-1 in Cancer Progression, and Synthetic Multivalent Systems for the Study of Galectin-1

This review discusses the role of galectin-1 in the tumor microenvironment. First, the structure and function of galectin-1 are discussed. Galectin-1, a member of the galectin family of lectins, is a functionally dimeric galactoside-binding protein. Although galectin-1 has both intracellular and extracellular functions, the defining carbohydrate-binding role occurs extracellularly. In this review, the extracellular roles of galectin-1 in cancer processes are discussed. In particular, the importance of multivalent interactions in galectin-1 mediated cellular processes is reviewed. Multivalent interactions involving galectin-1 in cellular adhesion, mobility and invasion, tumor-induced angiogenesis, and apoptosis are presented. Although the mechanisms of action of galectin-1 in these processes are still not well understood, the overexpression of galectin-1 in cancer progression indicates that the role of galectin-1 is significant. To conclude this review, synthetic frameworks that have been used to modulate galectin-1 processes are reviewed. Small molecule oligomers of carbohydrates, carbohydrate-functionalized pseudopolyrotaxanes, cyclodextrins, calixarenes, and glycodendrimers are presented. These synthetic multivalent systems serve as important tools for studying galectin-1 mediated cancer cellular functions.

Cancer stem cells in head and neck squamous cell carcinoma

Recent studies have demonstrated that cancer stem cells (CSC) play an important role in the pathobiology of head and neck squamous cell carcinomas (HNSCC). This subpopulation of undifferentiated, self-renewing cells is responsible for resistance to conventional anti-cancer therapy, cancer recurrence, metastasis and ability to form a heterogeneous tumor. CSC are identified on the basis of specific markers, including membrane proteins or cell enzymes, or by using their self-renewal properties. As their resistance to standard HNSCC treatment may eventually lead to the lack of treatment success, there is an urgent need to better understanding CSC biology and identify them as potential target new treatment modality.

Characteristics of invasive breast ductal carcinoma, NOS, diagnosed in a tertiary institution in the East Coast of Malaysia with a focus on tumor angiogenesis

BACKGROUND

Prognosis of breast cancer depends on classic pathological factors and also tumor angiogenesis. This study aimed to evaluate the clinicopathological factors of breast cancer in a tertiary centre with a focus on the relationship between tumor angiogenesis and clinicopathological factors.

METHODS

Clinicopathological data were retrieved from the archived formal pathology reports for surgical specimens diagnosed as invasive ductal carcinoma, NOS. Microvessels were immunohistochemically stained with anti-CD34 antibody and quantified as microvessel density.

RESULTS

At least 50% of 94 cases of invasive breast ductal carcinoma in the study were advanced stage. The majority had poor prognosis factors such as tumor size larger than 50mm (48.9%), positive lymph node metastasis (60.6%), and tumor grade III (52.1%). Higher percentages of estrogen and progesterone receptor negative cases were recorded (46.8% and 46.8% respectively). Her-2 overexpression cases and triple negative breast cancers constituted 24.5% and 22.3% respectively. Significantly higher microvessel density was observed in the younger patient age group (p=0.012). There were no significant associations between microvessel density and other clinicopathological factors (p>0.05).

CONCLUSIONS

Majority of the breast cancer patients of this institution had advanced stage disease with poorer prognostic factors as compared to other local and western studies. Breast cancer in younger patients might be more proangiogenic.

Decreased expression of light chain 3 (LC3) increased the risk of distant metastasis in triple-negative breast cancer

The aim of this study was to evaluate the prognostic value of light chain 3 (LC3) expression in triple-negative breast cancer (TNBC) and describe the association of LC3 expression with the occurrence of metastasis. LC3 expression in tissue microarray was evaluated by immunohistochemistry in 163 patients with TNBC. The prognostic value of LC3 expression was assessed by a Cox regression model adjusted for clinical characteristics. Low LC3 expression in TNBC was observed in 56 (34.4 %) of 163 TNBC. Low LC3 expression significantly correlated with a higher risk of distant metastasis, rather than locoregional relapse. The 10-year distant metastases-free survival for LC3-negative and LC3-positive patients was 57.2 and 95.1 %, respectively (p < 0.0001). Accordingly, a significant correlation was found between LC3 expression and disease-free survival (DFS) and overall survival (OS). Multivariate analysis indicated that LC3 negative was a significant independent prognostic factor of DFS (p = 0.019), but not for OS (p = 0.545) in all patients. Our results suggested that expression of LC3 in TNBC was associated with higher distant metastases. This finding could open new avenues for the development of novel therapy strategies to TNBC.

Impact of CD68/(CD3+CD20) ratio at the invasive front of primary tumors on distant metastasis development in breast cancer

Tumors are infiltrated by macrophages, T and B-lymphocytes, which may favor tumor development by promoting angiogenesis, growth and invasion. The aim of this study was to investigate the clinical relevance of the relative amount of macrophages (CD68⁺), T-cells (CD3⁺) and B-cells (CD20⁺) at the invasive front of breast carcinomas, and the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs) either at the invasive front or at the tumor center. We performed an immunohistochemical study counting CD3, CD20 and CD68 positive cells at the invasive front, in 102 breast carcinomas. Also, tissue sections were stained with MMP-2, -9, -11, -14 and TIMP-2 antibodies, and immunoreactivity location, percentage of reactive area and intensity were determined at the invasive front and at the tumor center. The results showed that an increased CD68 count and CD68/(CD3+CD20) ratio were directly associated with both MMP-11 and TIMP-2 expression by mononuclear inflammatory cells at the tumor center (p = 0.041 and p = 0.025 for CD68 count and p = 0.001 and p = 0.045 for ratio, respectively for MMP-11 and TIMP-2). In addition, a high CD68/(CD3+CD20) ratio (>0.05) was directly associated with a higher probability of shortened relapse-free survival. Multivariate analysis revealed that CD68/(CD3+CD20) ratio was an independent factor associated with distant relapse-free survival (RR: 2.54, CI: (1.23–5.24), p<0.01). Therefore, CD68/(CD3+CD20) ratio at the invasive front could be used as an important prognostic marker.

Transglutaminases: future perspectives

This is the third special issue focused on "Transglutaminases" that is now available on this journal and dedicated to one of the pioneers of these enzymes, John Edward Folk, who died December 2010 [see in this issue Beninati et al. 2012a]. The first edition, "Polyamines and Transglutaminases" was published in Amino Acids, vol 26, no. 4, 2004, with the contribution of two prestigious Guest Editors as Alberto Abbruzzese and Mauro Piacentini. This editorial initiative was followed by the second special issue published in occasion of the 50th years of the discovery of transglutaminase. Indeed, "Transglutaminase 2: 50th Anniversary of the Discovery" Amino Acids, vol 36, no. 4, 2009, was published with the valuable collaboration of Carlo Maria Bergamini and Mauro Piacentini (Beninati et al. 2009). To continue with this editorial tradition, on this occasion, an outstanding board of Guest Editors composed by Francesco Facchiano and Mauro Piacentini has also been invited to promote this initiative and recruit a selected panel of Authors, many of who participated in the first and second edition of the Gordon Conference on Transglutaminases: "Transglutaminases in Human Diseases Processes" chaired by Rickard L Eckert and Kapil Mehta on July 18-23, 2010, and by Kapil Mehta and Mauro Piacentini on July 15-20, 2012, held at Davidson College, NC, USA. In this Amino Acids special issue, the manuscripts were selected to reflect the progress and the future perspectives of transglutaminases.

Neovascularization after irradiation: what is the source of newly formed vessels in recurring tumors?

Local relapse of tumors after radiation therapy remains a challenge in oncology. To devise rational approaches for preventing this relapse, we have to improve our understanding of how new vessels form in previously irradiated tumors. We propose that tumor regrowth after local irradiation is dependent on blood vessel formation by local endothelial cells without the need for recruitment of endothelial precursor cells from distant nonirradiated tissues or bone marrow. We also suggest that infiltrating myeloid bone marrow-derived cells promote survival of local endothelial cells during the early period after irradiation and angiogenesis during the later stage of tumor regrowth, both via paracrine mechanisms.

The role of TG2 in ECV304-related vasculogenic mimicry

Tumour vasculogenesis can occur by a process referred to as vasculogenic mimicry, whereby the vascular structures are derived from the tumour itself. These tumours are highly aggressive and do not respond well to anti-angiogenic therapy. Here, we use the well characterised ECV304 cell line, now known as the bladder cancer epithelial cell line T24/83 which shows both epithelial and endothelial characteristics, as a model of in vitro vasculogenic mimicry. Using optimised ratios of co-cultures of ECV304 and C378 human fibroblasts, tubular structures were identifiable after 8 days. The tubular structures showed high levels of TG2 antigen and TG in situ activity. Tubular structures and in situ activity could be blocked either by site-directed irreversible inhibitors of TG2 or by silencing the ECV304 TG2 by antisense transfection. In situ activity for TG2 showed co-localisation with both fibronectin and collagen IV. Deposition of these proteins into the extracellular matrix could be reduced by inclusion of non-cell penetrating TG inhibitors when analysed by Western blotting suggesting that the contribution of TG2 to tube formation is extracellular. Incubation of ECV304 cells with these same irreversible inhibitors reduced cell migration which paralleled a loss in focal adhesion assembly, actin cytoskeleton formation and fibronectin deposition. TG2 appears essential for ECV304 tube formation, thus representing a potential novel therapeutic target in the inhibition of vasculogenic mimicry.

Autophagy patterns and prognosis in uveal melanomas

Autophagy is a self-degradation mechanism by which cells recycle their own cytoplasmic constituents. It has been claimed that, under certain conditions, such a process may be associated with tumor progression. In this study, the autophagic activity was investigated in a series of 99 uveal melanomas after immunohistochemical staining for the autophagy-associated proteins MAP1LC3A and BECN1, most commonly known as LC3A and Beclin 1, respectively. These were assessed in parallel with the hypoxia-inducible factor 1α (HIF1A) and its downstream protein lactate dehydrogenase 5 (composed by five LDHA subunits). Increased autophagic reactivity, detected by MAP1LC3A or BECN1, was associated with intense pigmentation and tumor hypoxia. Uveal melanomas with extensive overexpression of BECN1 or those with underexpression of this protein were associated with the worst prognosis, but the former manifested metastases much earlier than the latter; only 58% of patients with extensive BECN1 overexpression were alive at 4 years, compared with 80% of patients with underexpressed patterns. It is concluded that autophagy is commonly upregulated in uveal melanomas, and may be associated with hypoxia and intense pigmentation. There is a strong association between extensive BECN1 overexpression and early metastases/poor prognosis, and between underexpression of this protein and late metastases/better prognosis.

Comparative analysis and clinical value of the expression of metalloproteases and their inhibitors by intratumour stromal mononuclear inflammatory cells and those at the invasive front of breast carcinomas

AIMS

Matrix metalloproteases (MMPs) and their inhibitors (TIMPs) play an essential role in the degradation of stromal connective tissue and basement membrane components. The aim of this study was to determine whether the dynamic analysis of these components can help to predict tumour aggressiveness.

METHODS AND RESULTS

An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs -1, -2, -7, -9, -11, -13 and -14 and TIMPs -1, -2 and -3. More than 5000 determinations on cancer specimens from 124 patients with invasive breast cancer were performed on the tumour centre core as well as on the invasive front. Immunostaining for MMPs/TIMPs on mononuclear inflammatory cells (MICs) was evaluated. To identify specific groups of tumours with distinct expression profiles, data obtained from both MICs populations were analysed by unsupervised hierarchical cluster analysis. When compared with MICs at the invasive front, intratumour MICs more frequently showed expression of MMP-7 and -1 and TIMP-3, but less frequently expression of MMP-9 and -11 and TIMP-2.

CONCLUSIONS

Our data led us to consider the need of further studies in order to identify subsets of MICs and other protein elements of the microenvironment as attractive targets for new therapeutic strategies against cancer.

LC3A-positive light microscopy detected patterns of autophagy and prognosis in operable breast carcinomas

Autophagy is a self-degradation mechanism by which cells recycle their own cytoplasmic constituents and dispose of excess or defective organelles after starvation and oxygen deprivation. An antibody to the microtubule-associated protein 1 light chain 3 (LC3A), recognizing both the soluble (LC3A-I) and the membrane-bound form (LC3A-II) of the protein, was used to detect autophagic activity in 102 breast carcinomas. Three distinct patterns were recognized: (1) diffuse cytoplasmic, (2) cytoplasmic/juxta-nuclear, and (3) "stone-like" pattern--dense, rounded, amorphous structures, 5 microm on average, typically enclosed within cytoplasmic vacuoles. The diffuse cytoplasmic pattern showed a direct association with estrogen and progesterone receptor expression. The juxta-nuclear pattern indicated a similar association with hormone receptors, an inverse association with tumor size, and a favorable prognosis. By contrast, an increased number of stone-like structures, probably representing an excessive autophagic response, was related to high-grade tumors and a less favorable outcome. Interestingly, 60 additional epithelial tumors of nonbreast origin disclosed identical autophagic patterns, and so did MDA231 breast cancer xenografts and HCT116 colon tumor spheroids (also analyzed by electron microscopy). Moreover, MCF-7 human breast cancer cell lines confirmed induction of LC3A by anoxia and Thapsigargin. It is concluded that autophagy can be readily recognized in breast carcinomas by light microscopy, after immunohistochemical staining with LC3A, but the significance of the various patterns expressed would need further evaluation.

Heterogeneous expression of cyclooxygenase-2 and inducible nitric oxide synthase within colorectal tumors: correlation with tumor angiogenesis

BACKGROUND

Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human cancers.

AIMS

To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis.

METHODS

Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE2 and NO at the same sites.

RESULTS

COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF.

CONCLUSION

Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.

Comparative analysis and clinical value of the expression of metalloproteases and their inhibitors by intratumor stromal fibroblasts and those at the invasive front of breast carcinomas

An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs -1, -2, -7, -9, -11, -13, -14, and TIMPs -1, -2 and -3. More than 5,000 determinations on cancer specimens from 124 patients with invasive breast cancer were performed at the center of the tumor and the invasive front. Immunostaining for MMPs/TIMPs by fibroblasts was evaluated. To identify specific groups of tumors with distinct expression profiles, the data obtained from both fibroblast populations were analyzed by unsupervised hierarchical cluster analysis. Intratumor stromal fibroblasts more frequently showed expression of MMP-2, -7, and -14, and TIMP-3, but less frequently of MMP-9 than fibroblasts at the invasive front. Multivariate analysis showed that a high profile of MMPs and TIMPs staining in both fibroblast populations was the most potent predictor factor of distant metastases, whereas a low staining profile in fibroblasts was associated with a low risk of metastases.

Isoform-specific expression of 14-3-3 proteins in human astrocytoma

BACKGROUND

14-3-3 protein plays crucial roles in tumorigenesis, including the maintenance of cell cycle and DNA repair, the prevention of apoptosis, among others. In mammalian cells, seven 14-3-3 isoforms (beta, epsilon, zeta, eta, theta, gamma and sigma) have been identified and each of these seems to have distinct tissue localizations and isoform-specific functions. In the present study, the levels of all seven 14-3-3 isoforms were examined in astrocytoma.

METHODS

The expression of 14-3-3 isoforms and their protein expression levels were examined in five glioma cell lines by western blotting. Then in astrocytoma tissues, we investigated expression percentages of each isoform by immunohistochemistry. The protein and mRNA expression levels of each isoform were also detected by western blotting and RT-PCR, respectively.

RESULTS

14-3-3beta and eta were specifically expressed in astrocytoma, and their expression frequencies and levels increased with the increase of astrocytoma malignancy. The result from glioma cell lines was consistent with that from astrocytoma tissue.

CONCLUSIONS

In our study, we found two tumor-specific isoforms of 14-3-3 in astrocytoma. They might be involved in astrocytoma tumorigenesis and may be useful as targets for therapy.

99mTc-NC100692--a tracer for imaging vitronectin receptors associated with angiogenesis: a preclinical investigation

INTRODUCTION

Technetium 99m (99mTc)-NC100692 is being developed as a marker of vitronectin receptor expression. The purpose of this study was to confirm the binding affinity [dissociation constant (Kd)] of 99mTc-NC100692 for a range of integrin receptors including alphavbeta3 and alphavbeta5 as well as to establish the biodistribution and metabolic stability of 99mTc-NC100692 in Wistar rats.

METHODS

The Kd of 99mTc-NC100692 for a range of human integrin receptors was established in an in vitro saturation binding assay. The biodistribution and metabolic stability of 99mTc-NC100692 in normal Wistar rats was investigated.

RESULTS

The Kd of 99mTc-NC100692 to alphavbeta3 and alphavbeta5 was less than 1 nM. It was not possible to saturate the binding of 99mTc-NC10092 towards alphaIIbbeta3, alpha5beta1, alpha3beta1 or alpha1beta1, and as a result, accurate Kd values could not be determined. The biodistribution of 99mTc-NC100692 in male and female Wistar rats showed that radioactivity was rapidly excreted, predominantly into the urine, with very little background tissue retention apart from the liver and kidneys. Kidney and liver retention was reduced in the presence of excess NC100692 ligand. In vivo, there was little systemic metabolism of 99mTc-NC100692.

CONCLUSIONS

99mTc-NC100692 has a high affinity for the vitronectin receptors that are associated with angiogenesis. 99mTc-NC100692 is metabolically stable in the systemic circulation of rats with a biodistribution that is favourable for imaging purposes. This evidence suggests that 99mTc-NC100692 might be a useful marker of vitronectin receptor expression in vivo.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer

BACKGROUND

Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors.

MATERIALS AND METHODS

In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha.

RESULTS

pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032).

CONCLUSIONS

pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

The invasive front in endometrial carcinoma: higher proliferation and associated derailment of cell cycle regulators

The aim of the study was to explore whether expression of proliferation and hypoxia-related proteins differs in the central parts and the invasive front in endometrial carcinomas. Proliferation-associated proteins Ki67 and cyclin A; cell cycle regulators p16, p21, p53, cyclin D1, cyclin E, and cdk2; and hypoxia-inducible factor 1alpha and its downstream factors glucose transporter 1, carbonic anhydrase IX, and vascular endothelial growth factor were immunohistochemically stained in paraffin-embedded specimens from endometrioid (n = 33), mucinous (n = 1), and serous (n = 5) endometrial carcinomas. The percentages of positive cells at the invasive front and central tumor parts were scored and compared. Ki67 (P < .001), cyclin E (P = .018), p16 (P = .003), and cdk2 (.001) were expressed higher at the invasive front than centrally (Wilcoxon signed ranks test). Higher expression of these antigens at the invasive front was seen in 31 of 38 cases for Ki67, in 16 of 39 cases for cyclin E, in 15 of 39 cases for cdk2, and in 11 of 39 cases for p16. The other cell cycle proteins and the hypoxia-related factors did not show significant differences in expression between the central parts and the invasive front. Endometrial carcinomas clearly show an invasive front that is characterized by higher proliferation and progressive derailment of the cell cycle regulators cyclin E, p16, and cdk2, but not by an increased hypoxic response.

Clinicopathological significance of stromal variables: angiogenesis, lymphangiogenesis, inflammatory infiltration, MMP and PINCH in colorectal carcinomas

Cancer research has mainly focused on alterations of genes and proteins in cancer cells themselves that result in either gain-of-function in oncogenes or loss-of-function in tumour-suppressor genes. However, stromal variables within or around tumours, including blood and lymph vessels, stromal cells and various proteins, have also important impacts on tumour development and progression. It has been shown that disruption of stromal-epithelial interactions influences cellular proliferation, differentiation, death, motility, genomic integrity, angiogenesis, and other phenotypes in various tissues. Moreover, stromal variables are also critical to therapy in cancer patients. In this review, we mainly focus on the clinicopathological significance of stromal variables including angiogenesis, lymphangiogenesis, inflammatory infiltration, matrix metalloproteinase (MMP), and the particularly interesting new cysteine-histidine rich protein (PINCH) in colorectal cancer (CRC).

Allometric Scaling Law Questions the Traditional Mechanical Model for Axillary Lymph Node Involvement in Breast Cancer

Purpose

To find a quantitative relationship between tumor size and frequency of axillary lymph node involvement.

Patients and Methods

The frequency of axillary node involvement versus primary tumor volume was analyzed in 10 selected series of patients incorporating a total of 57,244 women with resectable breast cancer. The average number of events per unit volume resulting in tumor spread to axillary lymph nodes before tumor surgical removal Θ(V)/V, was estimated under simple probabilistic assumptions.

Results

The allometric scaling law Θ(V)/V = 0.0586V−0.7457 was estimated on the data, fitting the proportion of lymph node involvement on tumor volume V (in microliters). The estimate 0.7457 (95% CI, 0.7200 to 0.7713) suggests that the true scaling exponent, under the assumed model, may be the fractional value, which characterizes scaling relationships for a wide variety of biologic variables at both the whole organism level and organ level.

Conclusion

Results suggest that the phenomenon should be related to some internal structural trait of the tumor. The vascular network seems to be the best candidate. This result does not support a mere mechanical model of lymphatic tumor spread. A more complex biology-based model of lymphohematogenous spread is suggested, in which the axillary nodes draining the lymph from the primary tumor may become activated by factors produced by both tumor cells and tumor stroma, thus favoring cell-selective homing of otherwise circulating tumor cells. The success of fractal features related to the internal architecture brings additional support to the consideration of primary breast cancer as an organ-like structure.

Hypoxia inducible factors 1alpha and 2alpha are associated with VEGF expression and angiogenesis in gallbladder carcinomas

AIMS

To investigate the significance of the hypoxia inducible factors HIF-1alpha and HIF-2alpha in gallbladder adenocarcinomas and their relation to angiogenesis and to the expression of VEGF, an angiogenic factor transcriptionally regulated by HIFalphas.

METHODS

HIF-1alpha and 2alpha expression was assessed immunohistochemically in 60 patients with early gallbladder adenocarcinomas, treated with surgery alone. In addition, the vascular density (VD) and the expression of the angiogenic factors VEGF and thymidine phosphorylase (TP) were examined. The results were correlated with clinico-pathological features and prognosis.

RESULTS

Overexpression of HIF-1alpha and 2alpha was significantly associated with increased tumor angiogenesis and VEGF expression, while HIF-2alpha was linked with upregulation of TP. None of these factors were associated with T-stage and tumor grade. Although HIFs did not relate significantly with prognosis, patients with HIF-1/2 expression who failed to switch-on VEGF or intratumoral angiogenesis had a favorable outcome.

CONCLUSION

Hypoxia inducible factors are upregulated in a large proportion of gallbladder adenocarcinomas, a feature strongly related to increased expression of VEGF and intensified angiogenesis.

Angiogenesis in colorectal cancer: prognostic and therapeutic implications

Angiogenesis is important for tumor growth and metastasis. This account reviews the clinicopathological studies conducted in the field of angiogenesis in colorectal cancer, the methods of assessing vascular-related characteristics in tissue sections and provides a background for the usefulness of antiangiogenic policies along with chemotherapy and radiotherapy. Highly angiogenic colorectal tumors are associated with aggressive histopathological features and poor patients' survival. Similarly, factors stimulating angiogenesis, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), and others, are commonly related to increased vascular density (VD) and, therefore, to an unfavorable clinical course. Anti-VEGF agents have improved prognosis in patients with metastatic colorectal cancer, when added to standard chemotherapy. It is expected that, in addition to adjuvant chemotherapy and radiotherapy, agents blocking the stimulatory effect of VEGF on endothelial cells would prove beneficial to the patient.

Guanylyl cyclase-dependent chemotaxis of endothelial cells in response to nitric oxide gradients

Nitric oxide (NO) is an important regulator of angiogenesis and neovascularization. The nature of endothelial cell motility responses to NO was examined using a Boyden chamber method. NO generated via decomposition of either DEA/NO or DETA/NO produced increases in human umbilical vein endothelial cell (HUVEC) chemotaxis, which were completely abrogated by ODQ, a soluble guanylyl cyclase inhibitor. Measurements of NO either directly by chemiluminescence or its chemistry with diaminofluorescein revealed that chemotaxis was driven by subtle NO gradients between the lower and the upper wells in this system. In addition to diffusion and volatilization from the upper chambers, the data showed that HUVEC consumption of NO contributed to these sustained gradients. Comparison of DEA/NO- and DETA/NO-mediated responses suggested that the persistence of spatial NO gradients is as significant as the absolute magnitude of NO exposure per unit time. The findings suggest that subnanomolar NO gradients are sufficient to mobilize endothelial cell migration into hypoxic tissue during neovascularization events, such as in wound healing and cancer.

Effect of hypoxia and TP53 mutation status and cytogenetics of normal and malignant mammary epithelium

It has been proposed that hypoxia favors the growth of tumor cells over normal cells, particularly tumor cells carrying TP53 mutations. Cytogenetic studies of breast cancer have shown that highly complex karyotypes seen in direct harvest preparations are rarely detected after short-term culture. In this study, 34 paired samples of breast carcinomas and grossly nontumorous tissue from the same breast were cultured at 20 and 5% (12 samples) or 20 and 0% oxygen (22 samples). Both carcinoma samples and nontumorous tissue survived at 0% oxygen. Recovery for 24 hours at 20% produced good yields for cytogenetic analysis. Lower oxygen levels did not specifically stimulate growth of tumor cells. Samples with TP53 mutations showed a consistently increased growth under anaerobic hypoxic conditions. Culture at 5% oxygen did not generally reveal more karyotypic abnormalities than found at 20%. In the samples cultured at 0 and 20%, karyotypic abnormalities were detected only in anaerobic hypoxic culture in two cases. Of the only four samples where more complex karyotypes were detected in the low-oxygen culture, two were TP53 mutated. Hypoxic treatment followed by recovery at 20% oxygen may thus increase the yield of complex karyotypes from a subset of breast carcinomas, particularly those with mutated TP53.

Comparison of metabolic pathways between cancer cells and stromal cells in colorectal carcinomas: a metabolic survival role for tumor-associated stroma

Understanding tumor metabolism is important for the development of anticancer therapies. Immunohistochemical evaluation of colorectal adenocarcinomas showed that cancer cells share common enzyme/transporter activities suggestive of an anaerobic metabolism [high lactate dehydrogenase 5 (LDH5)/hypoxia-inducible factor alphas (HIFalphas)] with high ability for glucose absorption and lactate extrusion [high glucose transporter 1 (GLUT1)/monocarboxylate transporter (MCT1)]. The tumor-associated fibroblasts expressed proteins involved in lactate absorption (high MCT1/MCT2), lactate oxidation (high LDH1 and low HIFalphas/LDH5), and reduced glucose absorption (low GLUT1). The expression profile of the tumor-associated endothelium indicated aerobic metabolism (high LDH1 and low HIFalphas/LDH5), high glucose absorption (high GLUT1), and resistance to lactate intake (lack of MCT1). It is suggested that the newly formed stroma and vasculature express complementary metabolic pathways, buffering and recycling products of anaerobic metabolism to sustain cancer cell survival. Tumors survive and grow because they are capable of organizing the regional fibroblasts and endothelial cells into a harmoniously collaborating metabolic domain.

Inclusion of Vasculature-Related Variables in the Dukes Staging System of Colon Cancer

PURPOSE

The Dukes stage is used to stratify colorectal cancer patients into groups of different prognosis and need of adjuvant radiotherapy and chemotherapy. However, approximately 80% of patients with Dukes stage C colorectal cancer receive cytotoxic therapy without any expected benefit, for such patients would either not relapse without adjuvant therapy or they would inevitably do so because of tumor resistance to the available regimens. On the other hand, as 20% of Dukes stage B patients would relapse after surgery, adjuvant therapy could improve their survival. Improvement of the Dukes stage predictive accuracy is necessary to better assign patients for adjuvant therapies, especially nowadays when antiangiogenic agents are being incorporated in the clinical practice.

PATIENTS AND METHODS

In this study, we examined the prognostic role of Dukes staging system in parallel with three vasculature-related variables (vascular invasion, tumor angiogenic activity, and vascular survival ability) in a series of 130 stage B/C patients with colorectal cancer treated with surgery alone (without adjuvant radiotherapy or chemotherapy).

RESULTS

Inclusion of vasculature-related variables in the Dukes staging system significantly improved the prognostic categorization of patients, identifying subgroups of B-stage and C-stage patients with an up to 40% and 60% 5-year survival difference, respectively.

CONCLUSIONS

Preliminary results show that the prognostic value of Dukes staging system is significantly improved after taking into account vasculature-related variables, which may be useful in stratifying patients for adjuvant therapies, highlighting also subgroups that may benefit the most from antiangiogenic agents.