The tumour microenvironment: a novel target for cancer therapy

Biomechanical Aspects in Bone Tumor Engineering

In the past decades, anticancer drug development brought the field of tumor engineering to a new level by the need of robust test systems. Simulating tumor microenvironment in vitro remains a challenge, and osteosarcoma-the most common primary bone cancer-is no exception. The growing evidence points to the inevitable connection between biomechanical stimuli and tumor chemosensitivity and aggressiveness, thus making this component of the microenvironment a mandatory requirement to the developed models. In this review, we addressed the question: is the "in vivo - in vitro" gap in osteosarcoma engineering bridged from the perspective of biomechanical stimuli? The most notable biomechanical cues in the tumor cell microenvironment are observed and compared in the contexts of in vivo conditions and engineered three-dimensional in vitro models. Impact statement The importance of biomechanical stimuli in three-dimensional in vitro models for drug testing is becoming more pronounced nowadays. This review might assist in understanding the key players of the biophysical environment of primary bone cancer and the current state of bone tumor engineering from this perspective.

Identification of fatty acid signature to predict prognosis and guide clinical therapy in patients with ovarian cancer

High-grade serous ovarian cancer (HGSOC) is a heterogeneous cancer characterized by high relapse rate. Approximately 80% of women are diagnosed with late-stage disease, and 15–25% of patients experience primary treatment resistance. Ovarian cancer brings tremendous suffering and is the most malignant type in all gynecologic malignancies. Metabolic reprogramming in tumor microenvironment (TME), especially fatty acid metabolism, has been identified to play a crucial role in cancer prognosis. Yet, the underlying mechanism of fatty acid metabolism on ovarian cancer progression is severely understudied. Recently, studies have demonstrated the role of fatty acid metabolism reprogramming in immune cells, but their roles on cancer cell metastasis and cancer immunotherapy response are poorly characterized. Here, we reported that the fatty acid–related genes are aberrantly varied between ovarian cancer and normal samples. Using samples in publicly databases and bio-informatic analyses with fatty acid–related genes, we disentangled that cancer cases can be classified into high- and low-risk groups related with prognosis. Furthermore, the nomogram model was constructed to predict the overall survival. Additionally, we reported that different immune cells infiltration was presented between groups, and immunotherapy response differed in two groups. Results showed that our signature may have good prediction value on immunotherapy efficacy, especially for anti–PD-1 and anti–CTLA-4. Our study systematically marked the critical association between cancer immunity in TME and fatty acid metabolism, and bridged immune phenotype and metabolism programming in tumors, thereby constructed the metabolic-related prognostic model and help to understand the underlying mechanism of immunotherapy response.

Dual-functional antitumor conjugates improving the anti-metastasis effect of combretastatin A4 by targeting tubulin polymerization and matrix metalloproteinases

This study prepared different novel conjugates containing tubulin and MMP inhibitors and assessed their anticancer effects. Typically, the conjugate 15g, which contained combretastatin A4 (CA4) and 2-(4-((diethoxyphosphono)(o-tolyl)methylamino)phenyl)acetic acid (19g) connected by an ester bond, showed the maximum effect against proliferation. Particularly, the conjugate yielded a reduced IC₅₀ value of 0.05 μM in controlling the proliferation of HepG2 cells compared to CA4 alone (0.09 μM). Systematic research indicated that 15g suppressed tubulin polymerization, induced cell cycle arrest at the G2/M phase, led to reactive oxidative stress (ROS) generation of HepG2 cells, and resulted in apoptosis by the mitochondrial-dependent apoptotic pathway. Moreover, 15g showed a potent effect on resistant metastasis by decreasing the levels of the proteins MMP2 and MMP9 in the HepG2 cells. Therefore, this conjugate is a potentially effective approach to improve the anti-metastatic effect of CA4 with high safety.

Understanding the complex pathogenesis of oral cancer: A comprehensive review

The pathogenesis of oral cancer is a complex and multifactorial process that requires a deep understanding of the underlying mechanisms involved in the development and progress of malignancy. The ever-improving comprehension of the diverse molecular characteristics of cancer, the genetic and epigenetic alterations of tumor cells, and the complex signaling pathways that are activated and frequently cross talk open up promising horizons for the discovery and application of diagnostic molecular markers and set the basis for an era of individualized management of the molecular defects underlying and governing oral premalignancy and cancer. The purpose of this article is to review the key molecular concepts that are implicated in oral carcinogenesis, especially focusing on oral squamous cell carcinoma, and to review selected biomarkers that play a substantial role in controlling the so-called "hallmarks of cancer," with special reference to recent advances that shed light on their deregulation during the different steps of oral cancer development and progression.

Targeting Endothelial Cell-Specific Molecule 1 Protein in Cancer: A Promising Therapeutic Approach

Despite the dramatic advances in cancer research in the past few years, effective therapeutic strategies are urgently needed. Endothelial cell-specific molecule 1 (ESM-1), a soluble dermatan sulfate proteoglycan, also known as endocan, serves as a diagnostic and prognostic indicator due to its aberrant expression under pathological conditions, including cancer, sepsis, kidney diseases, and cardiovascular disease. Significantly, ESM-1 can promote cancer progression and metastasis through the regulation of tumor cell proliferation, migration, invasion, and drug resistant. In addition, ESM-1 is involved in the tumor microenvironment, containing inflammation, angiogenesis, and lymph angiogenesis. This article reviews the molecular and biological characteristics of ESM-1 in cancer, the underlying mechanisms, the currently clinical and pre-clinical applications, and potential therapeutic strategies. Herein, we propose that ESM-1 is a new therapeutic target for cancer therapy.

Selective mediation of ovarian cancer SKOV3 cells death by pristine carbon quantum dots/Cu2O composite through targeting matrix metalloproteinases, angiogenic cytokines and cytoskeleton

It was shown that some nanomaterials may have anticancer properties, but lack of selectivity is one of challenges, let alone selective suppression of cancer growth by regulating the cellular microenvironment. Herein, we demonstrated for the first time that carbon quantum dots/Cu2O composite (CQDs/Cu2O) selectively inhibited ovarian cancer SKOV3 cells by targeting cellular microenvironment, such as matrix metalloproteinases, angiogenic cytokines and cytoskeleton. The result was showed CQDs/Cu2O possessed anticancer properties against SKOV3 cells with IC50 = 0.85 μg mL-1, which was approximately threefold lower than other tested cancer cells and approximately 12-fold lower than normal cells. Compared with popular anticancer drugs, the IC50 of CQDs/Cu2O was approximately 114-fold and 75-fold lower than the IC50 of commercial artesunate (ART) and oxaliplatin (OXA). Furthermore, CQDs/Cu2O possessed the ability to decrease the expression of MMP-2/9 and induced alterations in the cytoskeleton of SKOV3 cells by disruption of F-actin. It also exhibited stronger antiangiogenic effects than commercial antiangiogenic inhibitor (SU5416) through down-regulating the expression of VEGFR2. In addition, CQDs/Cu2O has a vital function on transcriptional regulation of multiple genes in SKOV3 cells, where 495 genes were up-regulated and 756 genes were down-regulated. It is worth noting that CQDs/Cu2O also regulated angiogenesis-related genes in SKOV3 cells, such as Maspin and TSP1 gene, to suppress angiogenesis. Therefore, CQDs/Cu2O selectively mediated of ovarian cancer SKOV3 cells death mainly through decreasing the expression of MMP-2, MMP-9, F-actin, and VEGFR2, meanwhile CQDs/Cu2O caused apoptosis of SKOV3 via S phase cell cycle arrest. These findings reveal a new application for the use of CQDs/Cu2O composite as potential therapeutic interventions in ovarian cancer SKOV3 cells.

Evaluation of density of tumor-associated macrophages using CD163 in histological grades of oral squamous cell carcinoma, an immunohistochemical study

Background:

Macrophages account for 30%–50% of the total inflammatory cell population of ''tumor microenvironment'' that plays an important role in cancer metastasis. M2 macrophages are designated as tumor-associated macrophages (TAMs). They are known to orchestrate all the stages of tumor progression. CD163 is TAMs–M2-specific marker.

Aims:

The aim of the study was to evaluate the role of TAMs using CD163 in different histological grades of oral squamous cell carcinoma (OSCC).

Setting and Design:

Expression of CD 163 was investigated in 30 histopthologically diagnosed cases of OSCC.

Materials and Methods:

Two sections of 4-μ thickness were stained with hematoxylin and eosin, CD163 (Cell Marque, USA). The expression of TAMs with CD163-positive cells was done by counting the number of macrophages in three high-power fields (×400), and the mean number of macrophages per HPF was evaluated.

Statistical Analysis:

The statistical analysis was performed using Statistical Software SPSS version 20.0.

Results:

CD163 TAMs score increasing in higher tumor, node, metastasis stages with significant positive correlation.

Conclusion:

With higher histological grades, CD163 TAMs score increased. Thus, TAMs may be considered as an independent factor for determining the progression of the tumor. The immunotherapeutic approaches to control M2 TAM numbers could protect against progression to malignancy.

Classifying the Linkage between Adipose Tissue Inflammation and Tumor Growth through Cancer-Associated Adipocytes

Recently, tumor microenvironment (TME) and its stromal constituents have provided profound insights into understanding alterations in tumor behavior. After each identification regarding the unique roles of TME compartments, non-malignant stromal cells are found to provide a sufficient tumorigenic niche for cancer cells. Of these TME constituents, adipocytes represent a dynamic population mediating endocrine effects to facilitate the crosstalk between cancer cells and distant organs, as well as the interplay with nearby tumor cells. To date, the prevalence of obesity has emphasized the significance of metabolic homeostasis along with adipose tissue (AT) inflammation, cancer incidence, and multiple pathological disorders. In this review, we summarized distinct characteristics of hypertrophic adipocytes and cancer to highlight the importance of an individual's metabolic health during cancer therapy. As AT undergoes inflammatory alterations inducing tissue remodeling, immune cell infiltration, and vascularization, these features directly influence the TME by favoring tumor progression. A comparison between inflammatory AT and progressing cancer could potentially provide crucial insights into delineating the complex communication network between uncontrolled hyperplastic tumors and their microenvironmental components. In turn, the comparison will unravel the underlying properties of dynamic tumor behavior, advocating possible therapeutic targets within TME constituents.

MiR-141-3p suppresses gastric cancer induced transition of normal fibroblast and BMSC to cancer-associated fibroblasts via targeting STAT4

BACKGROUND

Cancer associated fibroblasts (CAFs) are known to be crucial constituents of cancer microenvironment (CME) and play an important role in initiation, progression and metastasis of various types of cancer, such as oral cancer, pancreatic cancer, and gastric cancer. CAFs are usually derived from normal fibroblasts (NFs), but the mechanism of the transition in gastric cancer has not yet been fully elucidated.

METHODS

qRT-PCR and western blot were employed to investigate differences of miR-141 and STAT4 expression respectively. The CAF-like features and wnt/β-catenin pathway related proteins in NF or BMSC were assessed by qRT-PCR or western blot after treated with the conditioned medium from different indicated groups of gastric cancer cells. The invasion and migration ability of AGS cells after transfection were analyzed by Transwell assay and wound healing assay. Dual-luciferase report assay was employed to determine the direct binding of miR-141 to STAT4 3' UTR.

RESULTS

For the first time, the present study found that STAT4 over-expression in gastric cancer cells induced NFs to obtain CAF-like features via activating wnt/β-catenin pathway. Further gain-of-function and loss-of-function analysis revealed that miR-141 not only limited the migration and invasion of the gastric cancer cells, but also inhibited the transition of NFs and BMSC to CAFs. The luciferase assay indicated that miR-141 directly targeted the 3'-UTR predictive sequence of STAT4.

CONCLUSION

Our data showed that miR-141 inhibited migration and invasion of gastric cancer cells and inhibited transition from NFs to CAFs via targeting STAT4/wnt/β-catenin pathway.

Immunological environment in colorectal cancer: a computer-aided morphometric study of whole slide digital images derived from tissue microarray

Cancer research has moved from investigating tumour cells to including analysis of the tumour microenvironment as well. The aim of this study was to assess the cellular infiltrate of colorectal cancer (CRC) using computer-aided analysis of whole slide digital image derived from tissue microarray (TMA). TMA slides from 31 CRC patients were immunostained for forkhead box protein 3 (FOXP3) and immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) at four sites: centre (C) and invasive front (F) of the tumour, proximal non-metastatic draining lymph node (N-), tumour-draining lymph node with metastasis (N+) and healthy mucosa at 10 cm from the cancer (M). We analysed the proportion of IDO+ tissue areas in the lamina propria or in the non-epithelial area of the lymph node and in epithelial cells in each site. The normal mucosa of patients operated on for benign disease was also analysed. The proportion (%) of FOXP3+ tissue area in C, F, N-, N+ and M were 2.3 ± 1.8, 2.6 ± 2.9, 6.0 ± 2.9, 14.2 ± 5.8 and 1.2 ± 0.8 (p < 0.001). The proportion (%) of IDO+ tissue area in the lamina propria of C, F, N-, N+ and M were 1.6 ± 3.1, 1.1 ± 1.3, 3.4 ± 2.5, 9.1 ± 8.5 and 6.7 ± 5.4 (p < 0.001). IDO+ tissue area in the lamina propria was not significantly different between healthy mucosa of patients with cancer than without (1.8 ± 3 vs 1.1 ± 0.95). The proportion of IDO positive tissue area in the epithelium was significantly higher in healthy mucosa of patients with cancer than without (5.4 ± 13.8 vs 2.1 ± 2.4). The FOXP3+ tissue area was increased in healthy mucosa of CRC patients in comparison with healthy mucosa of patients with colorectal resection for disease other than cancer: 1.20 ± 1.81 versus 0.81 ± 0.51 (p < 0.05). The proportion of IDO+ tissue area in lymph node (N-) was correlated with the proportion of FOXP3+ tissue area in tumour area (r = 0.44, p < 0.01). TMA technique permits simultaneous analysis of FOXP3+ and IDO+ cells at different sites including tumour, draining non-metastatic lymph node, metastatic lymph node and normal mucosa.

Anaplastic transition within the cancer microenvironment in early-stage oral tongue squamous cell carcinoma is associated with local recurrence

The cancer microenvironment (CME) promotes malignant progression of cancer cells by stimulating cell growth, migration and invasion. Cancer-associated fibroblasts (CAFs), prominent features of the CME, interact directly with cancer cells and facilitate epithelial-mesenchymal transition (EMT). The present study examined the spatial distribution of CAFs and EMT on cancer cells in patients with early-stage tongue squamous cell carcinoma (TSCC) and their association with local recurrence. The present study included 14 patients with early-stage TSCC who had undergone glossectomy between 2006 and 2015, of which 7 experienced local recurrence (LR group) and 7 did not (control group). Multiple immunofluorescent analysis (MIA) of PCNA, αSMA, vimentin, E-cadherin and cytokeratin 14 (CK14) was performed on slides obtained from surgical specimens to identify the expression of various cell-specific markers. The number of CAFs in the CME was significantly increased in the LR group (P=0.001). Furthermore, the neighbouring cancer cells were positive for vimentin expression, indicating EMT. However, the present study also identified concurrent expression of CK14 in all vimentin-positive cancer cells, whilst epithelial markers, including E-cadherin, were expressed in certain vimentin-positive cancer cells. Concurrent expression of CK14 and vimentin is not defined as EMT or partial EMT. Therefore, the present study proposed a novel mechanism of anaplastic transition (APT), in which epithelial cancer cells concurrently develop mesenchymal features, which is achieved by pathways other than EMT. APT is characterized such that epithelial cancer cells differentiate into more primitive states, which is different from EMT or partial EMT, and it may be associated with LR. The concept aids in improving knowledge regarding tumor recurrence in patients with early-stage TSCC.

Peptide and peptide-carbon nanotube hydrogels as scaffolds for tissue & 3D tumor engineering

The use of hybrid self-assembling peptide (EFK8)-carbon nanotube (SWNT) hydrogels for tissue engineering and in vitro 3D cancer spheroid formation is reported. These hybrid hydrogels are shown to enhance the attachment, spreading, proliferation and movement of NIH-3T3 cells relative to that observed using EFK8-only hydrogels. After five days, ∼30% more cells are counted when the hydrogel contains SWNTs. Also, 3D encapsulation of these cells when injected in hydrogels does not adversely affect their behavior. Compressive modulus measurements and microscopic examination suggest that SWNTs have this beneficial effect by providing sites for cell anchorage, spreading and movement rather than by increasing hydrogel stiffness. This shows that the cells have a particular interaction with SWNTs not shared with EFK8 nanofibers despite a similar morphology. The effect of EFK8 and EFK8-SWNT hydrogels on A549 lung cancer cell behavior is also investigated. Increasing stiffness of EFK8-only hydrogels from about 44 Pa to 104 Pa promotes a change in A549 morphology from spheroidal to a stretched one similar to migratory phenotype. EFK8-SWNT hydrogels also promote a stretched morphology, but at lower stiffness. These results are discussed in terms of the roles of both microenvironment stiffness and cell-scaffold adhesion in cancer cell invasion. Overall, this study demonstrates that applications of peptide hydrogels in vitro can be expanded by incorporating SWNTs into their structure which further provides insight into cell-biomaterial interactions.

STATEMENT OF SIGNIFICANCE

For the first time we used hybrid self-assembling peptide-carbon nanotube hybrid hydrogels (that we have recently introduced briefly in the "Carbon" journal in 2014) for tissue engineering and 3D tumor engineering. We showed the potential of these hybrid hydrogels to enhance the efficiency of the peptide hydrogels for tissue engineering application in terms of cell behavior (cell attachment, spreading and migration). This opens up new rooms for the peptide hydrogels and can expand their applications. Also our system (peptide and peptide-CNT hydrogels) was used for cancer cell spheroid formation showing the effect of both tumor microenvironment stiffness and cell-scaffold adhesion on cancer cell invasion. This was only possible based on the presence of CNTs in the hydrogel while the stiffness kept constant. Finally it should be noted that these hybrid hydrogels expand applications of peptide hydrogels through enhancing their capabilities and/or adding new properties to them.

In Vivo Hemin Conditioning Targets the Vascular and Immunologic Compartments and Restrains Prostate Tumor Development

Purpose: Conditioning strategies constitute a relatively unexplored and exciting opportunity to shape tumor fate by targeting the tumor microenvironment. In this study, we assessed how hemin, a pharmacologic inducer of heme oxygenase-1 (HO-1), has an impact on prostate cancer development in an in vivo conditioning model.Experimental Design: The stroma of C57BL/6 mice was conditioned by subcutaneous administration of hemin prior to TRAMP-C1 tumor challenge. Complementary in vitro and in vivo assays were performed to evaluate hemin effect on both angiogenesis and the immune response. To gain clinical insight, we used prostate cancer patient-derived samples in our studies to assess the expression of HO-1 and other relevant genes.Results: Conditioning resulted in increased tumor latency and decreased initial growth rate. Histologic analysis of tumors grown in conditioned mice revealed impaired vascularization. Hemin-treated human umbilical vein endothelial cells (HUVEC) exhibited decreased tubulogenesis in vitro only in the presence of TRAMP-C1-conditioned media. Subcutaneous hemin conditioning hindered tumor-associated neovascularization in an in vivo Matrigel plug assay. In addition, hemin boosted CD8⁺ T-cell proliferation and degranulation in vitro and antigen-specific cytotoxicity in vivo A significant systemic increase in CD8⁺ T-cell frequency was observed in preconditioned tumor-bearing mice. Tumors from hemin-conditioned mice showed reduced expression of galectin-1 (Gal-1), key modulator of tumor angiogenesis and immunity, evidencing persistent remodeling of the microenvironment. We also found a subset of prostate cancer patient-derived xenografts and prostate cancer patient samples with mild HO-1 and low Gal-1 expression levels.Conclusions: These results highlight a novel function of a human-used drug as a means of boosting the antitumor response. Clin Cancer Res; 23(17); 5135-48. ©2017 AACR.

Rubus idaeus extract suppresses migration and invasion of human oral cancer by inhibiting MMP-2 through modulation of the Erk1/2 signaling pathway

Raspberries (Rubus idaeus L.) have been extensively studies worldwide because of their beneficial effects on health. Recently reports indicate that crude extracts of Rubus idaeus (RIE) have antioxidant and anticancer ability. The aim of this study was to evaluate the mechanism of its antimetastatic ability in oral cancer cells. In this study, SCC-9 and SAS oral cancer cells were subjected to a treatment with RIE and then analyzed the effect of RIE on migration and invasion. The addition of RIE inhibited the migration and invasion ability of oral cancer cells. Real time PCR, western blot and zymography analysis demonstrated that mRNA, protein expression and enzyme activity of matrix metalloproteinases-2 (MMP-2) were down-regulated by RIE. Moreover, the phosphorylation of Focal adhesion kinase (FAK), src, and extracellular signal-regulated kinase (ERK) were inhibited after RIE treatment. In conclusion, these results demonstrated that RIE exerted an inhibitory effect of migration and invasion in oral cancer cells and alter metastasis by suppression of MMP-2 expression through FAK/Scr/ERK signaling pathway. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1037-1046, 2017.

Comparative assessment of HIF-1α and Akt responses in human lung and skin cells exposed to benzo[α]pyrene: Effect of conditioned medium from pre-exposed primary fibroblasts

Exposure to atmospheric pollutants has been accused for many adverse health effects. Benzo[α]pyrene (Β[α]Ρ) in particular, the most extensively studied member of pollutants, is implicated in both cancer initiation and promotion. In the present study, we compared the effects of noncytotoxic doses of Β[α]Ρ, between human skin and lung epithelial cells A431 and A549, respectively, focusing on Akt kinase and HIF-1α, as it is well known that these proteins are upregulated in various human cancers promoting survival, angiogenesis and metastasis of tumor cells. Also, taking into consideration that fibroblasts are involved in cancer progression, we tested the possible modulation of epithelial cell response by paracrine factors secreted by Β[α]Ρ-treated fibroblasts. Low doses of Β[α]Ρ were found to enhance epithelial cell proliferation and upregulate both Akt kinase and HIF-1α, with A549 cells exhibiting a more sustained profile of upregulation. It is to notice that, the response of HIF-1α was remarkably early, acting as a sensitive marker in response to airborne pollutants. Also, HIF-1α was induced by Β[α]Ρ in both lung and skin fibroblasts indicating that this effect may be conserved throughout different cell types and tissues. Interestingly however, the response of both proteins was differentially modified upon treatment with conditioned medium from Β[α]Ρ-exposed fibroblasts. This is particularly evident in A459 cells and confirms the critical role of intercellular and paracrine factors in the modulation of the final response to an extracellular signal. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1103-1112, 2016.

Excessive collagen turnover products are released during colorectal cancer progression and elevated in serum from metastatic colorectal cancer patients

During cancer progression, the homeostasis of the extracellular matrix becomes imbalanced with an excessive collagen remodeling by matrix metalloproteinases. As a consequence, small protein fragments of degraded collagens are released into the circulation. We have investigated the potential of protein fragments of collagen type I, III and IV as novel biomarkers for colorectal cancer. Specific fragments of degraded type I, III and IV collagen (C1M, C3M, C4M) and type III collagen formation (Pro-C3) were assessed in serum from colorectal cancer patients, subjects with adenomas and matched healthy controls using well-characterized and validated ELISAs. Serum levels of the biomarkers were significantly elevated in colorectal cancer patients compared to subjects with adenomas (C1M, Pro-C3, C3M) and controls (C1M, Pro-C3). When patients were stratified according to their tumour stage, all four biomarkers were able to differentiate stage IV metastatic patients from all other stages. Combination of all markers with age and gender in a logistic regression model discriminated between metastatic and non-metastatic patients with an AUROC of 0.80. The data suggest that the levels of these collagen remodeling biomarkers may be a measure of tumour activity and invasiveness and may provide new clinical tools for monitoring of patients with advanced stage colorectal cancer.

A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn’t showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody–drug conjugates (ADC) or immunotoxins.

Analysis of angiogenic markers in oral squamous cell carcinoma-gene and protein expression

Purpose

Therapeutic strategies attacking oral squamous cell carcinoma have not essentially succeeded to improve long-term prognosis and overall survival over the last decades. Therefore, in this study, we aimed to illuminate the molecular regulation of angiogenesis in this tumour entity in order to demask novel markers of prognosis or therapeutic approach.

Materials and methods

A panel of significant transcriptional alterations in angiogenic genes of 83 cancer samples was established by comparison to 30 samples of healthy oral mucosa with microarray technique. Immunohistochemistry (IHC) was performed to trace the signalling cascade from gene to protein level.

Results

A distinctive expression profile of VEGFA, EFNB2, PECAM1/CD31, ANGPT1 and ANGPT2 was revealed: VEGFA, EFNB2, and ANGPT2 were found overexpressed in 84 % to 95 % of tumour samples. In contrast, the expression of CD31 and ANGPT1 was downregulated in 80 % to 95 % of tumour samples. IHC confirmed results of the microarray analysis.

Tumours with lymphatic spread showed higher gene expression rates of VEGFA, EFNB2 and ANGPT2 in moderately differentiated tumours and of VEGFA and EFNB2 in small tumours, respectively. The ANGPT1/ ANGPT2 transcription ratio was found decreased in larger tumours and especially in tumours without lymphatic spread.

Conclusions

A characteristic expression profile of angiogenic markers was established. The specific overexpression of EFNB2 in small tumours with lymphatic spread and the typical decrease of the ANGPT1/ ANGPT2 ratio in larger tumours give weight to EFNB2 and angiopoietins as prognostic factors and potential therapeutic targets.

A role for cancer-associated fibroblasts in inducing the epithelial-to-mesenchymal transition in human tongue squamous cell carcinoma

OBJECTIVES

Lymph node metastasis is a prominent clinical feature of tongue squamous cell carcinoma (TSCC) and is associated with a higher mortality rate. Carcinoma-associated fibroblasts (CAFs), a major component of the tumor microenvironment (TME), play an important role in tumor progression, and are associated with a poor prognosis. The aim of this study was to examine the role of CAFs in promoting the invasion of TSCC through the epithelial-to-mesenchymal transition (EMT).

MATERIALS AND METHODS

A series of matched CAF and normal fibroblast (NF) pairs were assessed for cell morphology and for the expression of alpha smooth muscle actin (α-SMA), stromal cell-derived factor-1 (SDF1), fibroblast-activating protein (FAP), vimentin, and cytokeratin (CK) markers. Transwell assays, Western blot analysis, reverse transcription-PCR, and immunofluorescence staining were used to assess the role of CAFs, as compared to that of NFs, in promoting proliferation, migration, invasion, and EMT in TSCC.

RESULTS

Both CAF and NF primary cultures expressed vimentin but not CK. CAFs showed significantly higher α-SMA protein levels, SDF1 secretion, and mRNA levels of α-SMA, SDF1, and FAP. We also found that co-culture with CAFs enhanced the proliferation and invasion of SCC9 cells. Moreover, co-culture with CAFs induced upregulation of the EMT markers fibronectin and vimentin, downregulation of E-cadherin, and enhanced invasion in SCC9 cells.

CONCLUSION

These results suggest that CAFs induce EMT marker expression and functional changes in TSCCs.

The potential of heparanase as a therapeutic target in cancer

Heparanase has generated substantial interest as therapeutic target for antitumor therapy, because its activity is implicated in malignant behavior of cancer cells and in tumor progression. Increased heparanase expression was found in numerous tumor types and correlates with poor prognosis. Heparanase, an endoglucuronidase responsible for heparan sulfate cleavage, regulates the structure and function of heparan sulfate proteoglycans, leading to disassembly of the extracellular matrix. The action of heparanase is involved in multiple regulatory events related, among other effects, to augmented bioavailability of growth factors and cytokines. Inhibitors of heparanase suppress tumor growth, angiogenesis and metastasis by modulating growth factor-mediated signaling, ECM barrier function and cell interactions in the tumor microenvironment. Therefore, targeting heparanase has potential implications for anti-tumor, anti-angiogenic and anti-inflammatory therapies. Current approaches for heparanase inhibition include development of chemically modified heparins, small molecule inhibitors and neutralizing antibodies. The available evidence supports the emerging utility of heparanase inhibition as a promising antitumor strategy, specifically in rational combination with other agents. The recent studies with compounds designed to block heparanase (e.g., modified heparins) provide a rational basis for their therapeutic application and optimization.

Targeting tetraspanins in cancer

INTRODUCTION

Tetraspanins are a family of small proteins that cross the membrane four times and form complexes by interacting between themselves and with a variety of transmembrane and cytosolic proteins, building a network of interactions referred to as tetraspanin web or tetraspanin enriched microdomains (TEMs). These domains provide a signaling platform involved in many important cellular functions and malignant processes.

AREAS COVERED

The authors describe the methods and the rationale for targeting tetraspanins in the therapy of cancer in this review.

EXPERT OPINION

Targeting tetraspanins in cancer may be a promising therapy due to the importance of tetraspanins in several steps of tumor formation, communication with the environment, dissemination, and metastasis.

Novel therapy for therapy-resistant mantle cell lymphoma: multipronged approach with targeting of hedgehog signaling

Mantle cell lymphoma (MCL) is one of the most aggressive B-cell lymphomas with a median patient survival of only 5-7 years. The failure of existing therapies is mainly due to disease relapse when therapy-resistant tumor cells remain after chemotherapy. Therefore, development and testing of novel therapeutic strategies to target these therapy-resistant MCL are needed. Here, we developed an in vivo model of therapy-resistant MCL by transplanting a patient-derived MCL cell line (Granta 519) into NOD/SCID mice followed by treatment with combination chemotherapy. Cytomorphologic, immunophenotypic, in vitro and in vivo growth analyses of these therapy-resistant MCL cells confirm their MCL origin and resistance to chemotherapy. Moreover, quantitative real-time PCR revealed the upregulation of GLI transcription factors, which are mediators of the hedgehog signaling pathway, in these therapy-resistant MCL cells. Therefore, we developed an effective therapeutic strategy for resistant MCL by treating the NOD/SCID mice bearing Granta 519 MCL with CHOP chemotherapy to reduce tumor burden combined with GLI-antisense oligonucleotides or bortezomib, a proteosome inhibitor, to target therapy-resistant MCL cells that remained after chemotherapy. This regimen was followed by treatment with MCL-specific cytotoxic T lymphocytes to eliminate all detectable leftover minimal residual disease. Mice treated with this strategy showed a significantly increased survival and decreased tumor burden compared to the mice in all other groups. Such therapeutic strategies that combine chemotherapy with targeted therapy followed by tumor-specific immunotherapy are effective and have excellent potential for clinical application to provide long-term, disease-free survival in MCL patients.

Nanoparticle preconditioning for enhanced thermal therapies in cancer

Nanoparticles show tremendous promise in the safe and effective delivery of molecular adjuvants to enhance local cancer therapy. One important form of local cancer treatment that suffers from local recurrence and distant metastases is thermal therapy. In this article, we review a new concept involving the use of nanoparticle-delivered adjuvants to 'precondition' or alter the vascular and immunological biology of the tumor to enhance its susceptibility to thermal therapy. To this end, a number of opportunities to combine nanoparticles with vascular and immunologically active agents are reviewed. One specific example of preconditioning involves a gold nanoparticle tagged with a vascular targeting agent (i.e., TNF-α). This nanoparticle embodiment demonstrates preconditioning through a dramatic reduction in tumor blood flow and induction of vascular damage, which recruits a strong and sustained inflammatory infiltrate in the tumor. The ability of this nanoparticle preconditioning to enhance subsequent heat or cold thermal therapy in a variety of tumor models is reviewed. Finally, the potential for future clinical imaging to judge the extent of preconditioning and thus the optimal timing and extent of combinatorial thermal therapy is discussed.

New vessel formation in peritumoral area of squamous cell carcinoma of the head and neck

BACKGROUND

This study was conducted to investigate the dynamic process of new vessel formation, fundamental for tumor growth and metastasis, in head and neck squamous cell carcinoma (HNSCC).

METHODS

We used immunohistochemistry, confocal laser-scanning microscopy, and reverse transcriptase-polymerase chain reaction to study endothelial cell and concomitant pericyte development with markers CD133, CD34, VEGFR-2, CD31, vWF, and STRO-1 in tumor and peritumoral tissues of 18 patients with HNSCC.

RESULTS

Highly compressed and structurally abnormal vessels with barely any activity of new vessel formation were found in tumor tissue, whereas the adjacent peritumoral tissue vessels showed a normal architecture with tight endothelial cell-pericyte interaction and a high activity of angiogenesis. Endothelial precursor cells expressing CD133/VEGFR-2 could be incorporated into these newly formed vessels, forming cell clusters from which a thin endothelial lining could emanate.

CONCLUSIONS

These data show a high activity of new vessel formation in the peritumoral stroma of HNSCC, with endothelial precursor cells being incorporated into these structures.

Mast cell: insight into remodeling a tumor microenvironment

Mast cells are of paramount importance to allergies, pathogen immune responses during infections, and angiogenesis, as well as innate and adaptive immune regulations. Beyond all these roles, mast cells are now more and more being recognized as modulators of tumor microenvironment. Notwithstanding mounting evidences of mast cell accumulation in tumors, their exact role in tumor microenvironment is still incompletely understood. In this review, we discuss the significant role of mast cells in the remodeling of tumor microenvironment by either releasing various factors after activation or interacting with other cells within tumor and, as a result, the possible role of mast cell in cancer invasion and metastasis. We also discuss recent findings that mast cells actively release microparticles, which account for the transfer of membrane-type receptor signal and regulatory molecules such as microRNAs to tumor cells and immune cells. These findings on mast cells provide further insights into the complexity of tumor microenvironment remodeling.

Hematopoietic derived cell infiltration of the intestinal tumor microenvironment in Apc Min/+ mice

Tumors consist of a heterogeneous population of neoplastic cells infiltrated by an equally heterogeneous collection of nonneoplastic cells that comprise the tumor microenvironment. Tumor growth, invasion, and metastasis depend on multiple interactions between these cells. To assess their potential as therapeutic targets or vehicles for tumor specific delivery of therapeutic agents, we examined the contribution of bone marrow derived cells (BMDCs) to the intestinal tumor microenvironment. Hematopoietic stem cells expressing the enhanced green fluorescent protein (eGFP) were transplanted into lethally irradiated ApcMin/+ mice, and their engraftment was analyzed by confocal microscopy. The results showed abundant infiltration of eGFP cells into the small intestine, colon, and spleen compared to heart, muscle, liver, lung, and kidney. Within the intestine, there was a pronounced gradient of engraftment along the anterior to posterior axis, with enhanced infiltration into adenomas. Immunofluorescence analysis showed that osteopontin was expressed in tumor stromal cells but not in nontumor stromal populations, suggesting that gene expression in these cells is distinct. Tumor vasculature in ApcMin/+ mice was chaotic compared to normal intestinal regions. Our data suggest that BMDCs can be harnessed for tumor-targeted therapies to enhance antitumor efficacy.

Epithelial tumor, invasion and stroma

Uncontrolled proliferation is a defining feature of the malignant phenotype. Nevertheless, the supportive network provided by the stroma is indispensable for further invasion, progression and metastasis of cancer cells. In addition, the role of inflammation in tumorigenesis is now generally accepted, and it has become evident that an inflammatory microenvironment is an essential component of tumor progression. Since skin tumors are common and easily assessable lesions with features at various stages of tumorigenesis, they provide a wide scope for research in this field to further our understanding of fundamental and clinical carcinogenesis. Some of the basic aspects of epithelial tumorigenesis, invasion and stromal reaction are reviewed in this paper.

Metronomic scheduling of anticancer treatment: the next generation of multitarget therapy?

Metronomic scheduling of anticancer treatment (MSAT) is progressively gaining interest after the antiangiogenic properties of metronomic chemotherapy and its potential to overcome drug resistance was initially described in 2000. MSAT has now grown beyond the anticipated scope of antiangiogenic chemotherapy, with accumulating evidence demonstrating that these treatments may also act by stimulating an antitumor immune response and could ultimately lead to reinduction of tumor dormancy. An increasing number of drugs, not initially developed as anticancer agents, are currently being used in metronomic protocols in order to increase treatment efficacy. Interestingly, these ‘repositioned’ agents can target cancer cells, the tumor vasculature or, more broadly, the tumor microenvironment. Malignant tumors are no longer regarded as simple congregations of cancer cells but as genuine tissues with various components such as blood vessels, fibroblasts, inflammatory cells and an extracellular matrix. These different components and their multiple interactions play a crucial role in tumor development and response to treatment. Therefore, future anticancer treatments will have to take into account the tumor microenvironment and aim to target the different cellular and molecular participants encompassed in a tumor, as well as their specific interactions. In this article, we explain why MSAT represents a very attractive strategy for developing next-generation multitarget therapies.

Significance of talin in cancer progression and metastasis

Upon detachment from the extracellular matrix, tumor epithelial cells and tumor-associated endothelial cells are capable of overcoming anoikis, gain survival benefits, and hence contribute to the process of metastasis. The focal-adhesion complex formation recruits the association of key adaptor proteins such as FAK (focal-adhesion kinase). Vimentin, paxillin, and talin are responsible for mediating the interaction between the actin cytoskeleton and integrins. Talin is an early-recruited focal-adhesion player that is of structural and functional significance in mediating interactions with integrin cytoplasmic tails leading to destabilization of the transmembrane complex and resulting in rearrangements in the extracellular integrin compartments that mediate integrin activation. Talin-mediated integrin activation plays a definitive role in integrin-mediated signaling and induction of downstream survival pathways leading to protection from anoikis and consequently resulting in cancer progression to metastasis. We recently reported that talin expression is significantly increased in prostate cancer compared with benign and normal prostate tissue and that this overexpression correlates with progression to metastatic disease implicating a prognostic value for talin during tumor progression. At the molecular level, talin is functionally associated with enhanced survival and proliferation pathways and confers anoikis resistance and metastatic spread of primary tumor cells via activation of the Akt survival pathway. In this review, we discuss the growing evidence surrounding the value of talin as a prognostic marker of cancer progression to metastasis and as therapeutic target in advanced prostate cancer, as well as the current understanding of mechanisms regulating its signaling activity in cancer.

Cathepsin K-upregulation in fibroblasts promotes matrigel invasive ability of squamous cell carcinoma cells via tumor-derived IL-1α

BACKGROUND

Cathepsin K (CTSK), a cysteine protease with strong collagenolytic properties, is involved in extracellular matrix turnover. In the previous studies, CTSK expression was detected in peritumoral fibroblasts (Fbs) around squamous cell carcinoma (SCC), but not in those surrounding benign epidermal tumors. However, the mechanism governing CTSK expression in epidermal tumors remains unclear.

OBJECTIVE

To study the regulatory mechanisms of fibroblastic CTSK expression in the SCC-stromal interaction.

METHODS

We examined dynamic interactions of Fbs with tumorigenic SCC cells (A431 and A253) or normal human keratinocytes.

RESULTS

SCC cells and normal keratinocytes did not synthesize CTSK, while Fbs constitutively expressed CTSK. When cocultured, SCC cells upregulated fibroblastic CTSK expression more potently than did normal keratinocytes, which was mainly attributable to SCC-derived IL-1α. Coculturing Fbs with SCC cells significantly augmented the matrigel invasive ability of SCC cells, which was downregulated when cocultured with CTSK knockdown Fbs or in the presence of neutralizing anti-IL-1α antibody.

CONCLUSION

The CTSK-upregulated Fbs generated by SCC-derived IL-1α may play a crucial role in the progression and invasion of SCC.

Multiparametric imaging of tumor response to therapy

There is an increasing opportunity to perform multifunctional imaging at a variety of organ sites with relatively short examination times. Each technique yields quantitative parameters that reflect specific aspects of the underlying tumor or tissue biology. Many biomarkers have emerged that provide unique information on tumor behavior, including response to treatment. The multiparametric approach combines the information from different functional imaging techniques; this goes beyond what can be achieved by using any single functional technique, thus allowing an improved understanding of biologic processes and of responses to therapeutic interventions. Multiparametric imaging has many potential clinical roles; it is useful for pharmaceutical drug development and for predicting therapeutic efficacy.

The heme oxygenase system and oral diseases

Oral Diseases (2011) 17, 252-257 Heme oxygenase (HO) system catabolizes heme into three products: carbon monoxide (CO), biliverdin/bilirubin and free iron, which consists of three forms identified to date: the oxidative stress-inducible protein HO-1 and the constitutive isozymes HO-2 and HO-3. HO has been involved in many physiological and pathophysiological processes, ranging from Alzheimer's disease to cancer. The interest in HO system by scientists and clinicians involved with the oral and maxillofacial region is fairly recent, and few papers currently cited on HO relate to diseases in this anatomical area. This review will focus on the current understanding of the physiological significance of HO-1 induction and its possible roles in the oral diseases studied to date. The implications for possible therapeutic manipulation of HO are also discussed.

Increasing the efficacy of oncolytic adenovirus vectors

Oncolytic adenovirus (Ad) vectors present a new modality to treat cancer. These vectors attack tumors via replicating in and killing cancer cells. Upon completion of the vector replication cycle, the infected tumor cell lyses and releases progeny virions that are capable of infecting neighboring tumor cells. Repeated cycles of vector replication and cell lysis can destroy the tumor. Numerous Ad vectors have been generated and tested, some of them reaching human clinical trials. In 2005, the first oncolytic Ad was approved for the treatment of head-and-neck cancer by the Chinese FDA. Oncolytic Ads have been proven to be safe, with no serious adverse effects reported even when high doses of the vector were injected intravenously. The vectors demonstrated modest anti-tumor effect when applied as a single agent; their efficacy improved when they were combined with another modality. The efficacy of oncolytic Ads can be improved using various approaches, including vector design, delivery techniques, and ancillary treatment, which will be discussed in this review.

Cancer-associated fibroblasts and epithelial-mesenchymal transition in metastatic oral tongue squamous cell carcinoma

We examined cancer-associated fibroblasts (CAFs) and a panel of immunohistochemical markers of epithelial-mesenchymal transition (EMT) in 19 pair-matched oral tongue squamous cell carcinoma (SCC) and metastatic tumors to regional lymph nodes (RLNs). alpha-Smooth muscle actin (alpha-SMA) was studied to identify CAFs. EMT was studied with syndecan-1, Cadherin-11, fibroblast-specific protein (FSP)-1, secreted protein acidic and rich in cysteine (SPARC) and Twist. Triple immunostaining in RLNs was used to highlight the carcinoma cells (E-cadherin and Ki-67) and their relationship to the CAFs (alpha-SMA). We found that metastatic RLNs hosted CAFs similarly as in pair-matched primary tumors. Expression of EMT markers is common in both primary and metastatic tumors. We demonstrate that metastatic carcinoma cells (Ki-67 positive) downregulate E-cadherin expression at the periphery of cancer islands, where they are in direct contact with CAFs. The supporting connective tissue microenvironment also commonly expresses syndecan-1, Cadherin-11, FSP-1, and SPARC. In conclusion, CAFs are common to both primary and metastatic SCC. We hypothesize that CAFs not only promote tumor invasion but also facilitate metastases, either by cometastasizing and/or being recruited to lymph nodes. Evidence of EMT is common within primary tumors and metastatic SCC and may be further modulated by CAFs.

Interventional therapy of head and neck cancer with lipid nanoparticle-carried rhenium 186 radionuclide

PURPOSE

Minimally invasive interventional cancer therapy with drug-carrying lipid nanoparticles (ie, liposomes) via convection-enhanced delivery by an infusion pump can increase intratumoral drug concentration and retention while facilitating broad distribution throughout solid tumors. The authors investigated the utility of liposome-carrying beta-emitting radionuclides to treat head and neck cancer by direct intratumoral infusion in nude rats.

MATERIALS AND METHODS

Four groups of nude rats were subcutaneously inoculated with human tongue cancer cells. After tumors reached an average size of 1.6 cm(3), the treatment group received an intratumoral infusion of liposomal rhenium-186 ((186)Re) (185 MBq [5 mCi]/cm(3) tumor). Three control groups were intratumorally infused with unlabeled liposomes, unencapsulated (186)Re-perrhenate, or unencapsulated intermediate (186)Re compound ((186)Re-N,N-bis[2-mercaptoethyl]-N',N'-diethyl-ethylenediamine [BMEDA]). In vivo distribution of (186)Re activity was measured by planar gamma-camera imaging. Tumor therapy and toxicity were assessed by tumor size, body weight, and hematology.

RESULTS

Average tumor volume in the (186)Re-liposome group on posttreatment day 14 decreased to 87.7% +/- 20.1%, whereas tumor volumes increased to 395.0%-514.4% on average in the other three groups (P< .001 vs (186)Re-liposome). The (186)Re-liposomes provided much higher intratumoral retention of (186)Re activity, resulting in an average tumor radiation absorbed dose of 526.3 Gy +/- 93.3, whereas (186)Re-perrhenate and (186)Re-BMEDA groups had only 3.3 Gy +/- 1.2 and 13.4 Gy +/- 9.2 tumor doses, respectively. No systemic toxicity was observed.

CONCLUSIONS

Liposomal (186)Re effectively treated head and neck cancer with minimal side effects after convection-enhanced interventional delivery. These results suggest the potential of liposomal (186)Re for clinical application in interventional therapy of cancer.

Oncolytic (replication-competent) adenoviruses as anticancer agents

IMPORTANCE OF THE FIELD

Whilst therapies for neoplasies have advanced tremendously in the last few decades, there is still a need for new anti-cancer treatments. One option is genetically-engineered oncolytic adenovirus (Ad) 'vectors'. These kill cancer cells via the viral replication cycle, and amplify the anti-tumor effect by producing progeny virions able to infect neighboring tumor cells.

AREAS COVERED IN THIS REVIEW

We provide a description of basic Ad biology and summarize the literature for oncolytic Ads from 1996 to the present.

WHAT THE READER WILL GAIN

An overall view of oncolytic Ads, the merits and drawbacks of the various features of these vectors, and obstacles to further development and future directions for research.

TAKE HOME MESSAGE

Ads are attractive for gene therapy because they are relatively innocuous, easy to produce in large quantities, genetically stable, and easy to manipulate. A variety of have been constructed and tested, in pre-clinical and clinical experiments. Oncolytic Ads proved to be remarkably safe; no dose-limiting toxicity was observed in any clinical trial, and the maximum tolerated dose was not reached. At present, the major challenge for researchers is to increase the efficacy of the vectors, and to incorporate oncolytic virotherapy into existing treatment protocols.

New perspectives in cancer virotherapy: bringing the immune system into play

Despite constant advances in medically orientated cancer studies, conventional treatments by surgery, chemotherapy or radiotherapy remain partly ineffective against numerous cancers. Oncolytic virotherapy – the use of replication-competent viruses that specifically target tumor cells – has opened up new perspectives for improved treatment of these pathologies. Certain viruses demonstrate a natural, preferential tropism for tumor cells, while others can be genetically modified to show such an effect. Several of these viruses have already been used in preclinical and clinical trials in different tumor models; these studies have provided encouraging results and, thus, confirm the growing interest presented by this therapeutic strategy. The role of the immune system in the efficacy of cancer virotherapy has been poorly documented for a long time; however, several recent reports have presented evidence of synergistic effects between both direct viral oncolysis and the activation of specific, anti-tumor immune responses. These findings offer an exciting outlook for the future of cancer virotherapy.

Anticancer Role of PPARgamma Agonists in Hematological Malignancies Found in the Vasculature, Marrow, and Eyes

The use of targeted cancer therapies in combination with conventional chemotherapeutic agents and/or radiation treatment has increased overall survival of cancer patients. However, longer survival is accompanied by increased incidence of comorbidities due, in part, to drug side effects and toxicities. It is well accepted that inflammation and tumorigenesis are linked. Because peroxisome proliferator-activated receptor (PPAR)-gamma agonists are potent mediators of anti-inflammatory responses, it was a logical extension to examine the role of PPARgamma agonists in the treatment and prevention of cancer. This paper has two objectives: first to highlight the potential uses for PPARgamma agonists in anticancer therapy with special emphasis on their role when used as adjuvant or combined therapy in the treatment of hematological malignancies found in the vasculature, marrow, and eyes, and second, to review the potential role PPARgamma and/or its ligands may have in modulating cancer-associated angiogenesis and tumor-stromal microenvironment crosstalk in bone marrow.