Environmental modulation of alpha(v), alpha(2) and beta(1) integrin subunit expression in human oesophageal squamous cell carcinomas

Role of Microenvironmental Components in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell cancer (HNSCC) is one of the ten most common malignant neoplasms, characterized by an aggressive course, high recurrence rate, poor response to treatment, and low survival rate. This creates the need for a deeper understanding of the mechanisms of the pathogenesis of this cancer. The tumor microenvironment (TME) of HNSCC consists of stromal and immune cells, blood and lymphatic vessels, and extracellular matrix. It is known that HNSCC is characterized by complex relationships between cancer cells and TME components. TME components and their dynamic interactions with cancer cells enhance tumor adaptation to the environment, which provides the highly aggressive potential of HNSCC and resistance to antitumor therapy. Basic research aimed at studying the role of TME components in HNSCC carcinogenesis may serve as a key to the discovery of both new biomarkers-predictors of prognosis and targets for new antitumor drugs. This review article focuses on the role and interaction with cancer of TME components such as newly formed vessels, cancer-associated fibroblasts, and extracellular matrix.

New-generation photosensitizer-anchored gold nanorods for a single near-infrared light-triggered targeted photodynamic-photothermal therapy

Traditional combined photodynamic and photothermal therapy (PDT/PTT) was limited in clinical treatment of cancer due to the exceptionally low drug delivery efficiency to tumor sites and the activation by laser excitation with different wavelengths. We have accidentally discovered that our synthesized chlorin e6-C-15-ethyl ester (HB, a new type of photosensitizer) be activated by a laser with an excitation wavelength of 660 nm. Herein, we utilized Au nanorods (AuNRs) as 660 nm-activated PTT carriers to be successively surface-functionalized with HB and tumor-targeting peptide cyclic RGD (cRGD) to develop HB-AuNRs@cRGD for single NIR laser-induced targeted PDT/PTT. The HB-AuNRs@cRGD could be preferentially accumulated within tumor sites and rapidly internalized by cancer cells. Thereby, the HB-AuNRs@cRGD could exhibit amplified therapeutic effects by producing both significant reactive oxygen species (ROS) and hyperthermia simultaneously under the guidance of fluorescence imaging. The tumor inhibition rate on ECA109 esophageal cancer model was approximately 77.04%, and the negligible systematic toxicity was observed. This study proposed that HB-AuNRs@cRGD might be a promising strategy for single NIR laser-induced and imaging-guided targeted bimodal phototherapy.

miR-30b-5p acts as a tumor suppressor microRNA in esophageal squamous cell carcinoma

Background

To study miR-30b-5p expression in esophageal squamous cell carcinoma (ESCC) by comparisons between tumor tissues and matched adjacent non-cancerous tissues to elucidate the correlation between miR-30b-5p expression and ESCC clinical parameters, and to explore the signaling pathways associated with miR-30b-5p and key target genes.

Methods

Clinical data, cancer tissues, and adjacent non-cancerous tissues of 32 patients diagnosed with ESCC were collected from Taizhou Hospital of Zhejiang Province. The expression levels of miR-30b-5p were determined by real-time polymerase chain reaction (RT-PCR). mRNA data for ESCC tissues and normal tissues, and clinical materials of patients with ESCC were obtained from the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA). Associations between miR-30b-5p expression and clinical features of patients with ESCC and overall survival were explored. A bioinformatics analysis was performed to determine the pathways and key miR-30b-5p targets associated with ESCC. Additionally, a cytological experiment was performed to evaluate the biological functions of miR-30b-5p. Finally, correlations between miR-30b-5p and key targets involved in PI3K/Akt signaling pathways were validated by western blotting.

Results

The expression level of miR-30b-5p in the 32 ESCC tissues was significantly lower than that in adjacent normal tissues (P<0.01) and was significantly disparate in the T stage, with higher expression in T1 than in T2 (P<0.05). Among the patients with higher expression levels of miR-30b-5p in ESCC tissues than in adjacent normal tissues, patients with higher expression of miR-30b-5p had a better prognosis (P<0.05). An analysis of gene chip data from the GEO database showed similar results. A gene enrichment analysis indicated a series of pathways that may be associated with the downregulation of miR-30b-5p, including focal adhesion, ECM-receptor interaction, and PI3K/Akt signaling pathways. Seven key target genes (PDGFRB, VIM, ITGA5, ACTN1, THBS2, SERPINE1, and RUNX2) were identified; these were found to be upregulated in ESCC tissues and were negatively correlated with miR-30b-5p. Functional experiments showed that miR-30b-5p attenuated migration (P<0.01) and invasion (P<0.05) in the Eca109 cell line. Moreover, the levels of ITGA5, PDGFRB, p-PI3K, and p-AKT, which are involved in the PI3K/Akt signaling pathway, were decreased in the miR-30b-5p-overexpressing Eca109 cell line.

Conclusions

Upregulated miR-30b-5p may inhibit migration and invasion in ESCC by targeting ITGA5, PDGFRB, and signaling pathways, such as PI3K/Akt, involved in ESCC regulation. Our results indicate that miR-30b-5p plays an important role in the occurrence and progression of ESCC and is a potential therapeutic target.

Near infrared fluorescent peptide nanoparticles for enhancing esophageal cancer therapeutic efficacy

Various types of nanoparticles have been proposed for targeted drug delivering, imaging, and tracking of therapeutic agents. However, highly biocompatible nanoparticles with structure-induced fluorescence and capability to conjugate with biomarkers and drugs remain lacking. This research proposes and synthesizes fluorescent nanoparticles (f-PNPs) assembled by cyclic peptides to combine imaging and drug delivering for esophageal cancer (EC). To achieve tumor targeting, f-PNPs are first conjugated with RGD moieties to selectively target EC cells via αvβ3 integrin; the nanoparticles are then embedded with epirubicin (EPI). Cell viability assays and analysis of tissue histology reveal that EPI-loaded RGD-f-PNPs (RGD-f-PNPs/EPI) led to significantly reduced cardiotoxicity and improved anti-tumor activity compared to EPI alone. Moreover, the drug delivery to tumor sites and therapeutic responses could be monitored with near-infrared fluorescence using RGD-f-PNPs/EPI. This unique nanoparticle system may lead to potential approaches for bioorganic fluorescence-based delivering, imaging, and drug release tracking.

Deoxycholic acid promotes development of gastroesophageal reflux disease and Barrett's oesophagus by modulating integrin-αv trafficking

The fundamental mechanisms underlying erosive oesophagitis and subsequent development of Barrett's oesophagus (BO) are poorly understood. Here, we investigated the contribution of specific components of the gastric refluxate on adhesion molecules involved in epithelial barrier maintenance. Cell line models of squamous epithelium (HET‐1A) and BO (QH) were used to examine the effects of bile acids on cell adhesion to extracellular matrix proteins (Collagen, laminin, vitronectin, fibronectin) and expression of integrin ligands (α₃, α_4, α₅, α₆ and α_ν). Experimental findings were validated in human explant oesophageal biopsies, a rat model of gastroesophageal reflux disease (GORD) and in patient tissue microarrays. The bile acid deoxycholic acid (DCA) specifically reduced adhesion of HET‐1A cells to vitronectin and reduced cell‐surface expression of integrin‐α_νvia effects on endocytic recycling processes. Increased expression of integrin‐α_v was observed in ulcerated tissue in a rat model of GORD and in oesophagitis and Barrett's intestinal metaplasia patient tissue compared to normal squamous epithelium. Increased expression of integrin‐α_ν was observed in QH BO cells compared to HET‐1A cells. QH cells were resistant to DCA‐mediated loss of adhesion and reduction in cell‐surface expression of integrin‐α_ν. We demonstrated that a specific component of the gastric refluxate, DCA, affects the epithelial barrier through modulation of integrin α_ν expression, providing a novel mechanism for bile acid‐mediated erosion of oesophageal squamous epithelium and promotion of BO. Strategies aimed at preventing bile acid‐mediated erosion should be considered in the clinical management of patients with GORD.

RGD-Binding Integrins in Head and Neck Cancers

Alterations in integrin expression and function promote tumour growth, invasion, metastasis and neoangiogenesis. Head and neck cancers are highly vascular tumours with a tendency to metastasise. They express a wide range of integrin receptors. Expression of the αv and β1 subunits has been explored relatively extensively and linked to tumour progression and metastasis. Individual receptors αvβ3 and αvβ5 have proved popular targets for diagnostic and therapeutic agents but lesser studied receptors, such as αvβ6, αvβ8, and β1 subfamily members, also show promise. This review presents the current knowledge of integrin expression and function in squamous cell carcinoma of the head and neck (HNSCC), with a particular focus on the arginine-glycine-aspartate (RGD)-binding integrins, in order to highlight the potential of integrins as targets for personalised tumour-specific identification and therapy.

Investigation of intercellular adhesion molecules (ICAMs) gene expressions in patients with Barrett's esophagus

The adhesion molecules play a major role in inflammation as well as in neoplastic diseases. The aim of this study is to evaluate the expressions of the adhesion molecules, intercellular adhesion molecule 1 (ICAM-1), ICAM-2, and ICAM-3, in Barrett's esophagus, recognized as a premalign lesion for esophageal cancer and related to inflammation. Eighteen patients with Barrett's esophagus according to endoscopy and 25 volunteers without Barrett's esophagus disease were included in the study. Tissue samples were supplied by biopsy and used for both gene expression and immunohistochemical analysis. The significance of the differences between the two groups was assessed by Student's t test. The ICAM-1 expression level was fivefold higher in the patient group compared with that of the control. There was an increase in the serum level of ICAM-1 in patients compared to that of the controls, but this increase was not significant. ICAM-2 levels were also increased in the patient group, but it was not significant. There was no difference between controls and patients in ICAM-3 levels. Significantly higher levels of ICAM-1 gene expression make us think that ICAM-1 may play an important role in Barrett's esophagus. We think that more studies, with larger patient groups and preferably detailed histopathological and clinical evaluations, are needed to explain the severity of ICAM-1, ICAM-2, and ICAM-3 molecules in Barrett's esophagus.

Differential expression profiles between α-dystroglycan and integrin β1 in ameloblastoma: two possible perlecan signalling pathways for cellular growth and differentiation

AIMS

Intercellular deposition of perlecan, an extracellular matrix molecule, results in characteristic stellate reticulum-like structures in ameloblastomas. The aims of this study were to elucidate which types of perlecan receptors function within any particular type of tissue architecture of ameloblastoma.

METHODS AND RESULTS

Protein and gene expression profiles for α-dystroglycan and integrin β1 were examined comparatively with those of their ligands in ameloblastoma using surgical specimens and cells in primary culture. In the follicular-type tumour cell foci, α-dystroglycan was localized uniformly over the stellate reticulum-like cells, while integrin β1 was restricted mainly to peripheral cells facing the stroma with the interface of the basement membrane, which was also rich in perlecan. In the plexiform-type, mRNA and protein signals for α-dystroglycan were enhanced in the periphery of tumour cell foci, especially in their invading fronts. Integrin β1 was also immunolocalized in the basal cell zone, which was considered to be the proliferation centre of ameloblastoma cells. Furthermore, biosynthesis of α-dystroglycan and integrin β1 by ameloblastoma cells was confirmed in vitro using immunofluorescence and reverse transcriptase-polymerase chain reaction.

CONCLUSIONS

Ameloblastoma cells proliferate and are differentiated by capturing perlecan differentially with α-dystroglycan and integrin β1, respectively.

FOXC2 is a novel prognostic factor in human esophageal squamous cell carcinoma

BACKGROUND

FOXC2 has been implicated in cancer progression through its induction of epithelial-to-mesenchymal transition. We analyzed the clinical significance of FOXC2 in esophageal cancer cases, in which early distant metastasis or invasion to nearby organs is an obstacle to treatment.

METHODS

Quantitative reverse transcriptase-polymerase chain reaction was used to evaluate FOXC2 mRNA expression in 70 esophageal cancer cases to determine the clinicopathologic significance of FOXC2 expression. Furthermore, we examined associations between FOXC2 expression and matrix metalloproteinases 2 (MMP2) and matrix metalloproteinases 9 (MMP9). We also performed in vitro invasion and migration assays for FOXC2-suppressed esophageal cancer cells.

RESULTS

In clinicopathologic analysis, the high-FOXC2 expression group showed a higher incidence of advanced tumor stage, lymph node metastasis, and lymphatic invasion than the low-FOXC2 expression group (P < 0.05). In particular, tumor stage exhibited the most remarkable difference (P < 0.0001). Expression of MMP2 and MMP9 was far higher in the high-FOXC2 expression group. Furthermore, the high-FOXC2 expression group had a significantly poorer prognosis than did the low expression group (P = 0.006). Multivariate analysis indicated that high FOXC2 expression was an independent prognostic factor for survival. Suppression of FOXC2 expression altered the invasive and the migratory ability of esophageal cancer cells in vitro.

CONCLUSIONS

Our findings suggest that FOXC2 could be an important prognostic indicator for esophageal cancer patients. FOXC2 is directly involved in cancer progression and is associated with poor prognosis in esophageal cancer cases.

Association of platelet glycoprotein Ia polymorphism with minor increase of risk for oral cancer

AIMS

In light to association of increased platelet glycoprotein Ia (GPIa) expression with tumor invasion and metastasis in several types of cancer, we investigated the possible contribution of a common polymorphism (C807/T807), affecting the GPIa gene expression, in the development of oral cancer.

METHODS

DNA samples of 110 patients with oral cancer and 114 healthy controls were examined by allele-specific polymerase chain reaction followed by electrophoretic analysis.

RESULTS

The mutant T807 allele homozygotes were significantly increased in the group of patients compared to the control group (P < 0.001). Furthermore, significantly increased frequency of mutant alleles compared to controls was observed in the subgroup of patients with a positive history for cancer (P < 0.01).

CONCLUSIONS

The obtained results indicate that the C807/T807 polymorphism is indeed a genetic predisposing factor which contributes to increased risk for oral cancer.

Expression of cell adhesion molecules in oesophageal carcinoma and its prognostic value

Oesophageal carcinoma remains a disease of poor prognosis. Surgical cure rates are compromised by the fact that most patients are diagnosed at a late stage of disease because of the delayed onset of symptoms, by which time metastases and organ infiltration may have already occurred. Thus, invasion and metastases play a key role in influencing patient survival, and the search for novel treatments may therefore hinge on gaining insight into the mechanisms controlling these processes. It has been established that the initial step in the metastatic cascade is the detachment of tumour cells from the primary tumour via dysregulation of normal cell-cell and cell-matrix interactions. Distinct proteins known as cell adhesion molecules (CAMs) mediate these interactions. In recent years, a plethora of information has contributed to the in depth understanding of these molecules. This review provides a brief description of five families of CAMs (cadherins, integrins, CD44, immunoglobulin superfamily, and selectins) and highlights their altered expression in relation both to prognosis and tumour behaviour in squamous cell carcinoma and adenocarcinoma of the oesophagus.

Expression of integrin subunits alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 in different histological types of ameloblastoma compared with dental germ, dental lamina and adult lining epithelium

OBJECTIVE

To analyze integrin expression and distribution in different histological types of ameloblastoma, compared with dental germ, dental lamina and adult lining epithelium.

MATERIALS AND METHODS

Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method and anti-integrin alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 antibodies.

RESULTS

All integrins were present in all specimens, exhibiting different patterns. In follicular ameloblastoma, the integrin staining was stronger in the periphery while integrin alpha2 was not present in the central cells. Acanthomatous ameloblastoma showed a similar pattern, with positive staining for integrins alpha3, alpha5, alphav, beta1 and beta4 in the metaplastic cells. In the unicystic, integrin staining was uniform except for integrins alpha5 and beta3 which showed weaker staining in the upper layers. In the plexiform ameloblastoma, dental germ and lamina integrin staining was uniform. In the adult lining epithelium, staining for integrins alpha2, alpha5 and beta4 was confined to the basal layer, while integrins alphav and beta3 were present in the basal and parabasal, with integrins alpha3 and beta1 in the upper layers.

CONCLUSION

Acanthomatous, follicular and unicystic ameloblastomas showed integrin staining patterns similar to the adult lining epithelium while the plexiform ameloblastoma was similar to the dental germ and lamina.

N-Myc overexpression leads to decreased beta1 integrin expression and increased apoptosis in human neuroblastoma cells

Neuroblastoma is a childhood tumor thought to arise through improper differentiation of neural crest cells. Increased N-Myc expression in neuroblastoma indicates highly malignant disease and poor patient prognosis. N-myc enhances cell growth, insulin-like growth factor type I receptor (IGF-IR) expression, and tumorigenicity in combination with Bcl-2. Despite these effects, N-Myc overexpression in SHEP neuroblastoma cells (SHEP/N-Myc cells) increases serum-withdrawal and mannitol-induced apoptosis. Although we have previously shown a protective effect of IGF-I in SHEP cells, in SHEP/N-Myc cells IGF-I rescue from mannitol-induced apoptosis is prevented. N-Myc overexpression has little effect on IGF-IR signaling pathways, but results in increased Akt phosphorylation when Bcl-2 is coexpressed. A loss of integrin-mediated adhesion promotes apoptosis in many systems. SHEP/N-Myc cells have dramatically less beta1 integrin expression than control cells, consistent with previous reports. beta1 integrin expression is decreased in more tumorigenic neuroblastoma cells lines, including IMR32 and SH-SY5Y cells. Reintroduction of beta1 integrin into the N-Myc-overexpressing cells prevents mannitol-mediated apoptosis. We speculate that N-Myc repression of beta1 integrin expression leads to a less differentiated phenotype, resulting in increased growth and tumorigenesis if properly supported or apoptosis if deprived of growth sustaining molecules.

Integrin alpha(v) and coxsackie adenovirus receptor expression in clinical bladder cancer

OBJECTIVES

To evaluate the expression of the coxsackie and adenovirus receptor (CAR) and alpha(v) integrins in clinical specimens of bladder cancer to determine the susceptibility to adenoviral gene therapy. Efficient adenovirus-based gene therapy requires binding of the virus to CAR and involves the alpha(v) integrins. Studies on bladder cancer cell lines have shown that low adenoviral transduction rates were associated with low-level expression of CAR. Integrin alpha(v) expression increases in various tumors suggest its importance in differentiation, proliferation, and migration. CAR is structurally a member of the Ig-type superfamily of cell-cell adhesion molecules, suggesting that its expression may also be related to the state of tumor differentiation.

METHODS

We performed immunohistochemistry for CAR and integrin alpha(v) expression in bladder cancer specimens in 50 paraffin-embedded tumor-normal pairs and confirmed the results by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of 11 separate bladder tumors and 4 separate normal bladder controls.

RESULTS

Immunochemistry demonstrated a stage and grade-dependent decrease in CAR expression (90.0%, 83.3%, and 31.3% of normal urothelium and superficial and invasive transitional cell carcinoma [TCC] and 83.3% and 39.5% of low and high-grade TCC, respectively). Furthermore, we found a stage and grade-dependent increase in alpha(v) integrin expression (13.3%, 46.0%, and 56.3% of normal urothelium, superficial TCC, and invasive TCC and 25% and 52.6% of low and high-grade TCC, respectively). Quantitative RT-PCR analysis confirmed a downregulation at the CAR gene expression level.

CONCLUSIONS

This down-regulation may have a major impact on developing adenoviral-based gene therapy modalities. In addition, we propose that loss of CAR expression decreases rigid cell adhesion, possibly increasing the migratory potential. Loss of CAR expression correlates with the invasive phenotype in our analysis of bladder cancer. Simultaneously, the finding of increased alpha(v) expression in invasive cancer suggests a pathogenesis that involves heterophilic adhesion and migration of these cells on various extracellular ligands.