High Expression of CD105 as a Prognostic Predictor of Early Tongue Cancer

Endoglin in head and neck neoplasms

Tumors of the head and neck region form a heterogeneous group of pathologies, including various benign lesions and malignant neoplasms. Endoglin, also known as CD105, is an accessory receptor for transforming growth factor beta (TGF-β), that regulates angiogenesis, both under physiological and pathological conditions. It is highly expressed in proliferating endothelial cells. Therefore, it is considered as a marker of tumor-related angiogenesis. In this review we discuss the role of endoglin as a possible marker of carcinogenesis, as well as a potential target for antibody-based therapies in the neoplasms of the head and neck region.

Prognostic value of blood and lymphatic vessel markers in tongue cancer: A systematic review

Tongue squamous cell carcinoma (TSCC) has a poor prognosis due to its early metastasis through blood and lymphatic vessels. We undertook a systematic review to investigate the prognostic significance of blood microvessel density (MVD) and lymphatic vessel density (LVD) in TSCC patients. We carried out a systematic search in Ovid Medline, Scopus, and Cochrane libraries. All studies that evaluated the prognostic significance of MVD/LVD markers in TSCC were systematically retrieved. Our results showed that MVD/LVD markers, CD31, CD34, CD105, factor VIII, lymphatic vessel endothelial hyaluronan receptor‐1, and D2‐40 were evaluated in TSCC patients until 28 June 2018. Six out of 13 studies reported markers that were associated with poor prognosis in TSCC. Two out of three studies suggested that a high number of D2‐40⁺ vessels predicated low overall survival (OS); the third study reported that the ratio of D2‐40⁺ over factor VIII⁺ vessels is associated with low OS. Most of the other markers had controversial results for prognostication. We found higher expression of MVD/LVD markers were commonly, but not always, associated with shorter survival in TSCC patients. It is therefore not currently possible to recommend implementation of these markers as reliable prognosticators in clinical practice. More studies (especially for D2‐40) with larger patient cohorts are needed.

Prognostic value of endoglin-assessed microvessel density in cancer patients: a systematic review and meta-analysis

Background

Endoglin (ENG, CD105), an auxiliary receptor for several TGF-β superfamily ligands, is constitutively expressed in tumor microvessels. The prognostic value of ENG-assessed microvessel density (MVD) has not been systemically analyzed. This meta-analysis reviews and evaluates the association between ENG expression and prognosis in cancer patients.

Materials and Methods

Thirty published studies involving in 3613 patients were included after searching of PubMed, Web of Science, and EMBASE. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) were calculated using random-effects models. The publication bias was detected by a Begg's test and Egger's test. The outcome stability was verified by sensitivity analysis.

Results

The high ENG-assessed MVD was significantly associated with poor OS (HR = 2.14, 95% CI 1.62-2.81; P < 0.001), DFS (HR = 3.23, 95% CI 2.10-4.95; P < 0.001), CSS (HR = 3.33, 95% CI 1.32-8.37; P < 0.001). Furthermore, subgroup analysis revealed that the association between the overexpression of ENG in tumor microvessels and the outcome endpoints (OS or DFS) were also significant in the Asians and Caucasians patients with different cancer types.

Conclusions

ENG of tumor microvessels is a predictor of poor OS, DFS and CSS and may be a prognostic marker of patients with cancer.

Prognosis of neutrophil-to-lymphocyte ratio in clinical early-stage tongue (cT1/T2N0) cancer

BACKGROUND

Inflammation plays a role in the development of cancer. This study aims to analyze the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and other clinicopathological determinants in early-stage (cT1/T2N0) tongue cancer.

MATERIALS AND METHODS

A total of 262 patients were selected from our institute's cancer database between 2004 and 2011. Optimal cutoff value of NLR and lymph node density (LND) were determined statistically using receiver operating characteristic curve analysis for survival prediction. The 5-year overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) rates were estimated using the Kaplan-Meier method.

RESULTS

The results showed that, in this cohort, the optimal cutoff value of NLR was 2.95 and for LND, it was 0.031. Patients with NLR ≥2.95 correlated significantly with positive N classification (P=0.011), T2 classification (P=0.007), positive perineural invasion (P<0.001), and a tumor thickness of >5 mm (P=0.005). The 5-year OS among patients with NLR <2.95 was much higher than that in patients with NLR ≥2.95 (P<0.001). Similarly, the 5-year DSS among patients with NLR <2.95 was much higher than that in patients with NLR ≥2.95 (P=0.002). The 5-year DFS among patients with NLR <2.95 was much higher than that in patients with NLR ≥2.95 (P=0.004). The 5-year OS, DSS, and DFS were significantly reduced among patients with LND >0.031 compared to those with LND <0.031, respectively. In multivariate analysis, NLR, LND, and tumor thickness were independent prognostic factors for OS.

CONCLUSION

Pretreatment NLR ≥2.95 is significantly correlated with a larger tumor, positive neck lymph node metastasis, and positive perineural invasion. Importantly, it indicates reduced survival rate. Therefore, if the NLR ≥2.95 in early-stage (cT1/T2N0) tongue cancer is noted preoperatively, it reveals more invasive tumor behavior clinically. Then, aggressive treatments, including elective neck dissection, become necessary.

Prognostic value of some tumor markers in unresectable stage IV oropharyngeal carcinoma patients treated with concomitant radiochemotherapy

Background

The aim of the study was to investigate how the expression of tumor markers p21, p27, p53, cyclin D1, EGFR, Ki-67, and CD31 influenced the outcome of advanced inoperable oropharyngeal carcinoma patients, treated with concomitant radiochemotherapy.

Patients and methods.

The pretreatment biopsy specimens of 74 consecutive patients with inoperable stage IV oropharyngeal squamous cell carcinoma treated with concomitant radiochemotherapy were in retrospective study processed by immunochemistry for p21, p27, p53, cyclin D1, EGFR, Ki-67, and CD31. Disease-free survival (DFS) was assessed according to the expression of tumor markers.

Results

Patients with a high expression of p21 (≥10%), p27 (>50%), Ki-67 (>50%), CD31 (>130 vessels/mm2) and low expression of p53 (<10%), cyclin D1 (<10%) and EGFR (<10%) (favorable levels - FL) had better DFS than patients with a low expression of p21 (<10%), p27 (≤50%), Ki-67 (≤50%), CD31 (<130 vessels/mm2) and high expression of p53 (≥10%), cyclin D1 (≥10%) and EGFR (≥10%) (unfavorable levels - UL). However, statistical significance in survival between FL and UL was achieved only for p27 and cyclin D1. DFS significantly decreased with an increasing number of markers with an unfavorable level per tumor (1–4 vs. 5–7) (78% vs. 32%, respectively; p = 0.004). The number of markers per tumor with UL of expression retained prognostic significance also in multivariate analysis.

Conclusions

Statistical significance in survival between FL and UL emerged only for p27 and cyclin D1. The number of markers per tumor with UL of expression was an independent prognostic factor for an adverse outcome.

Circulating CD105 shows significant impact in patients of oral cancer and promotes malignancy of cancer cells via CCL20

CD105 is rich in endothelium cells and is involved in angiogenesis. Higher microvascular density of tumor is also related to the prognosis in a variety of cancers. In this present study, patients with positive N classification, advanced T classification, advanced TNM stage, extracapsular spread of lymph nodes (ECS), and perineural invasion had significantly higher levels of peripheral vein (pCD105) and venous return from tumor (tCD105) in 71 patients with OSCC compared to 13 healthy volunteers. Those with higher pCD105 or tCD105 levels had significantly poorer 5-year disease-specific survival rate (DDS) and overall survival rate (OS). The tCD105 and pCD105 levels and ECS were the independent prognostic factors by the multivariate analysis according to the Cox regression model in 5-year DDS and OS rate. SAS and SCC4 cells treated with CD105 showed the increase in migration, invasion, and proliferation in vitro and in vivo. Furthermore, CCL20 expression participated in CD105-elicited cell motility in oral cancer cells. In conclusion, higher level of circulating CD105 is related to adverse pathological features among patients with OSCC. It is also a useful marker for evaluating the prognosis and targeting therapeutics of OSCC.

Triple-positive pathologic findings in oral cavity cancer are related to a dismal prognosis

OBJECTIVES/HYPOTHESIS

Perineural invasion (PNI), lymphovascular invasion (LVI), and extracapsular spread (ECS) of lymph nodes are adverse histopathologic factors among patients with oral cancer. We analyzed the clinical impact of the combination of PNI, LVI, and ECS among patients with oral cancer.

STUDY DESIGN

Retrospective analysis of patients with oral cancer that was treated primarily with surgery with at least 5 years of follow-up data in a tertiary referral center.

METHODS

In total, 554 patients diagnosed with oral cavity squamous cell carcinoma who underwent operations consecutively between 2006 and 2008 in our hospital were enrolled. Clinical characteristics, 5-year survival rates, and local/regional control rates were analyzed.

RESULTS

There were 41 females and 513 males. Patients with PNI, LVI, or ECS presented pathologically had 5-year overall survival rates of 58.4%, 50.4%, and 31.4%, respectively. Patients with both ECS and PNI or both ECS and LVI presented had 5-year overall survival rates of 31.5% and 22.2%, respectively. Patients presenting with triple-positive status (PNI, LVI, and ECS) had only a 20.0% 5-year overall survival rate. The 5-year local/regional control rate for patients with both ECS and PNI or both ECS and LVI was 26% and 44.4%, respectively; for all three factors, it was 26.7%.

CONCLUSION

Patients with triple-positive status (PNI, LVI, ECS), ECS and PNI, or ECS and LVI experienced very low 5-year local/regional control rates, 5-year overall, and disease-specific survival rates. Novel interventions are necessary to improve these clinical outcomes.

LEVEL OF EVIDENCE

4.

Lymphangiogenesis and podoplanin expression in oral squamous cell carcinoma and the associated lymph nodes

The objective of this study was to evaluate lymphangiogenesis in oral squamous cell carcinoma and in the associated lymph nodes and podoplanin expression in neoplastic cells at the invasive front. In addition, the association of the above parameters with lymph node metastasis was also investigated. We used immunohistochemistry to examine primary tumors and lymph nodes, regardless of metastasis. Lymphatic vessel density (LVD) and microvessel density (MVD) were assessed by antibodies D2-40 and CD105, respectively, in intratumoral and peritumoral areas and in lymph node regions. Vascular endothelial growth factor-C and vascular endothelial growth factor receptor-3 expression was evaluated in tumor cells and D2-40 (podoplanin) expression in parenchymal cells found at the invasive front. The majority of cases with nodal involvement presented a high peritumoral LVD. In addition, a strong association of LVD with size and site of primary tumors could also be identified. MVD was statistically associated with metastasis, and a significant association between the lymphangiogenic factors and the density of vessels in the intratumoral region was also seen. The well-differentiated tumors did not express podoplanin. LVD and MVD were higher in metastatic lymph nodes than in nonmetastatic lymph nodes. The enhanced vascular network in metastatic lymph nodes reinforces the previous reports of lymphangiogenesis occurrence in lymph nodes. Moreover, the expression of podoplanin by more undifferentiated tumor cells suggests that this protein could be an indicator of tumor aggressiveness.

The expression of activin receptor-like kinase 1 among patients with head and neck cancer

OBJECTIVES

We investigated the expression and clinical significance of activin receptor-like kinase 1 (ACVRL1) in patients with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Case series with chart review.

SETTING

Academic Institute of Otolaryngology, Kaohsiung, Taiwan.

SUBJECTS AND METHODS

Patients diagnosed with HNSCC (n = 169) underwent surgical resection followed by radiotherapy and/or chemotherapy for aggressive tumors between November 2000 and March 2004. ACVRL1 expression was assessed using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry approaches.

RESULTS

High levels of ACVRL1 expression were significantly correlated with advanced T classification (P < .001), positive N classification (P = .002), advanced TNM stage (P < .001), lymphovascular invasion (P < .001), and extracapsular spread of lymph node metastasis (P = .021). A poor 5-year overall survival rate was correlated with high ACVRL1 expression (P = .0048), advanced T classification (P = .0075), positive N classification (P = .0024), advanced TNM stage (P = .0077), and extracapsular spread of lymph node (P = .0002), but a multivariate analysis using the Cox regression model revealed that the only independent prognostic factors for survival were ACVRL1 expression (P = .043; odds ratio [OR], 1.635; 95% confidence interval [CI], 1.017-2.629) and extracapsular spread of lymph node metastasis (P = .003; OR, 2.052; 95% CI, 1.270-3.315).

CONCLUSION

A high level of ACVRL1 expression in tumor tissue is significantly correlated with advanced T classification, positive N classification, advanced TNM stage, and poorer prognosis.

The role of angiogenin in pT1-T2 tongue carcinoma neo-angiogenesis and cell proliferation: an exploratory study

BACKGROUND

Angiogenin (ANG) is a member of the ribonuclease superfamily and of medical interest largely because it supports the growth of primary and metastatic malignancies. This study is the first to investigate the potential role of ANG in tongue carcinoma neo-angiogenesis and cancer cell proliferation.

METHODS

Angiogenin expression (in carcinoma cells and endothelial intratumor vessel cells), CD105-assessed micro-vessel density (MVD), and MIB-1 expression were correlated with prognostic parameters in 28 primarily consecutively operated pT1-T2 tongue carcinomas (squamous cell carcinoma [SCC]). Whenever feasible, a computer-based image analysis system was used for the immunohistochemical reaction analysis.

RESULTS

No significant correlations emerged between ANG expression in the tongue carcinoma cells or endothelial intratumor vessel cells and tongue SCC recurrence rate or disease-free survival (DFS). ANG expression was also unrelated to CD105-assessed MVD or MIB-1 expression. Conversely, CD105-assessed MVD correlated directly with recurrence rate (P = 0.02) and DFS was significantly shorter in cases with CD105-assessed MVD >167 micro-vessels/mm(2) than in those with CD105-assessed MVD ≤167 micro-vessels/mm(2) (P = 0.042).

CONCLUSIONS

Our results support the hypothesis that CD105-assessed MVD would be a valuable parameter for predicting which patients with tongue SCC are at greatest risk of disease recurrence. Despite our study results, the role of ANG in tongue carcinoma warrants further investigation in larger series.

Endoglin for tumor imaging and targeted cancer therapy

INTRODUCTION

Although cancer treatment has evolved substantially in the past decades, cancer-related mortality rates are still increasing. Therapies targeting tumor angiogenesis, crucial for the growth of solid tumors, mainly target vascular endothelial growth factor (VEGF) and have been clinically applied during the last decade. However, these therapies have not met high expectations, which were based on therapeutic efficacy in animal models. This can partly be explained by the upregulation of alternative angiogenic pathways. Therefore, additional therapies targeting other pro-angiogenic pathways are needed.

AREAS COVERED

The transforming growth factor (TGF)-β signaling pathway plays an important role in (tumor) angiogenesis. Therefore, components of this pathway are interesting candidates for anti-angiogenic therapy. Endoglin, a co-receptor for various TGF-β family members, is specifically overexpressed in tumor vessels and endoglin expression is associated with metastasis and patient survival. Therefore, endoglin might be a good candidate for anti-angiogenic therapy. In this review, we discuss the potential of using endoglin to target the tumor vasculature for imaging and therapeutic purposes.

EXPERT OPINION

Considering the promising results from various in vitro studies, in vivo animal models and the first clinical trial targeting endoglin, we are convinced that endoglin is a valuable tool for the diagnosis, visualization and ultimately treatment of solid cancers.

Role of platelet derived growth factor receptor (PDGFR) over-expression and angiogenesis in ependymoma

New molecularly targeted therapies are needed for childhood ependymoma. Angiogenesis and the PDGFR pathway could be potential therapeutic targets. This study aimed to screen ependymomas for the expression and clinicopathological correlates of angiogenic factors and potential therapeutic targets including VEGFR, endoglin (CD105), CD34, CD31, c-Kit, PDGFR-α and PDGFR-β. Immunohistochemistry for angiogenesis factors and PDGFR-α and β was performed in 24 archival tumor samples from children and adults treated for ependymoma at our institution. CD31 density, CD105 density and pericyte coverage index (PCI) were calculated. These findings were correlated with clinical outcome. VEGFR2 was overexpressed in tumor cells in only one out of 24 cases, but was found overexpressed in the vessels in 6 cases. PDGFR-α and β were found to be over-expressed in the ependymoma tumor cells in seven out of 24 cases (29.2 %). CD31 density, CD105 density and PCI did not correlate with expression of PDGFRs. Overexpression of PDGFR-α and β in tumor cells and overexpression of PDGFR-α in tumor endothelium had prognostic significance and this was maintained in multivariate analysis for overexpression of PDGFR-α in tumor cells (2 year progression free survival was 16.7 ± 15.2 for cases with overexpression of PDGFR-α in the tumor vs. 74.5 ± 15.2 for those with low/no expression, hazard ratio = 5.78, p = 0.04). A number of angiogenic factors are expressed in ependymoma tumor cells and tumor endothelium. Preliminary evidence suggests that the expression of PDGFRs could have a prognostic significance in ependymoma. This data suggests that PDGFRs should be further evaluated as targets using novel PDGFR inhibitors.

Prognostic value of vascular endothelial growth factor in patients with head and neck cancer: A meta-analysis

BACKGROUND

The correlation between vascular endothelial growth factor (VEGF) overexpression and the clinical outcome of head and neck cancer remains inconclusive. This meta-analysis aimed to evaluate the prognostic value of VEGF in patients with head and neck cancer.

METHODS

We searched Ovid MEDLINE, EMBASE and 2 Chinese science databases in order to enroll all eligible articles. Forty-seven studies were included in this meta-analysis. All results were evaluated by the random-effects model.

RESULTS

VEGF overexpression is significantly associated with worse overall survival (OS; hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.61-2.22) and progression-free survival (PFS; HR, 1.68; 95% CI, 1.33-2.12). Subgroup analysis reveals that VEGF overexpression is a significant poor predictor for nasopharyngeal cancer (HR, 1.66; 95% CI, 1.30-2.12) and salivary gland cancer (HR, 3.32; 95% CI, 1.61-6.84).

CONCLUSION

Our meta-analysis supports that VEGF overexpression is an available poor predictor for patients with head and neck cancer.

Clinical significance of erythropoietin receptor expression in oral squamous cell carcinoma

BACKGROUND

Hypoxic tumors are refractory to radiation and chemotherapy. High expression of biomarkers related to hypoxia in head and neck cancer is associated with a poorer prognosis. The present study aimed to evaluate the clinicopathological significance of erythropoietin receptor (EPOR) expression in oral squamous cell carcinoma (OSCC).

METHODS

The study included 256 patients who underwent primary surgical resection between October 1996 and August 2005 for treatment of OSCC without previous radiotherapy and/or chemotherapy. Clinicopathological information including gender, age, T classification, N classification, and TNM stage was obtained from clinical records and pathology reports. The mRNA and protein expression levels of EPOR in OSCC specimens were evaluated by Q-RT-PCR, Western blotting and immunohistochemistry assays.

RESULTS

We found that EPOR were overexpressed in OSCC tissues. The study included 17 women and 239 men with an average age of 50.9 years (range, 26-87 years). The mean follow-up period was 67 months (range, 2-171 months). High EPOR expression was significantly correlated with advanced T classification (p < 0.001), advanced TNM stage (p < 0.001), and positive N classification (p = 0.001). Furthermore, the univariate analysis revealed that patients with high tumor EPOR expression had a lower 5-year overall survival rate (p = 0.0011) and 5-year disease-specific survival rate (p = 0.0017) than patients who had low tumor levels of EPOR. However, the multivariate analysis using Cox's regression model revealed that only the T and N classifications were independent prognostic factors for the 5-year overall survival and 5-year disease-specific survival rates.

CONCLUSIONS

High EPOR expression in OSCC is associated with an aggressive tumor behavior and poorer prognosis in the univariate analysis among patients with OSCC. Thus, EPOR expression may serve as a treatment target for OSCC in the future.

Clinical and pathological determinants in tonsillar cancer

BACKGROUND

The purpose of this study was to present the impact of clinicopathological factors on patient survival in tonsillar squamous cell carcinoma (SCC) that needs to be evaluated.

METHOD

This study enrolled 86 patients with tonsillar SCC undergoing surgical resection.

RESULTS

The cumulative 5-year disease-specific survival (DSS) rate for stages I, II, III, and IVa/b tumors was 100%, 91.7%, 100%, and 61.8%, respectively. Unfavorable cumulative 5-year DSS rates were significantly correlated with advanced T classification (p = .029), tumor thickness over 1 cm (p = .007), 3 or more positive neck lymph nodes (p < .001), and extracapsular spread (ECS; p = .002). Cox regression analysis revealed that the presence of 3 or more positive neck lymph nodes (p = .035) and the stage IVa/b (p = .022) were the independent predictors of the 5-year DSS.

CONCLUSION

Patients with tonsillar SCC with stage IVa/b and metastasis to 3 or more lymph nodes have poorer clinical outcomes. Novel therapeutic strategies are necessary for these patients.

Prognostic significance of immunohistochemical biomarkers in oral squamous cell carcinoma

Advances in understanding of the molecular mechanisms underlying oral squamous cell carcinoma (OSCC) have resulted in an increasing number of biomarkers that can be used to predict the behaviour of this disease. The authors conducted a literature review of studies examining the role of immunohistochemistry-based protein biomarkers in predicting OSCC outcome. Only articles published in PubMed-indexed journals over the past 5 years were considered. 22 molecular biomarkers were identified and classified into five groups based on their biological functions: cell cycle acceleration and proliferation; tumour suppression and apoptosis; hypoxia; angiogenesis; and cell adhesion and matrix degradation. The cell cycle acceleration and proliferation biomarkers showed the most divergent prognostic findings. Studies on tumour suppression and apoptosis biomarkers were the most prevalent. There were only a few studies examining molecular biomarkers of hypoxia and angiogenesis, and studies examining cell adhesion and matrix degradation biomarkers have shown that this group has the greatest potential for assessing prognostic parameters. Amongst the several proteins analysed, the immunohistochemical expression levels of epithelial growth factor receptor (EGFR), p53, and matrix metalloproteinases (MMPs) have demonstrated the greatest potential for survival prediction in OSCC, but this review demonstrates that their prognostic relevance is debatable and requires further standardisation.

CD105 is a marker of tumour vasculature and a potential target for the treatment of head and neck squamous cell carcinoma

BACKGROUND

The importance of angiogenesis in solid tumour growth is well recognised. Tumour angiogenesis is considered the result of an imbalance between pro- and anti-angiogenic factors produced by both the malignancy and normal cells. Endoglin (CD105) is a proliferation-associated, hypoxia-inducible glycoprotein that seems to be clinically superior to other pan-endothelial markers in the selective evaluation of tumour angiogenesis. Several studies have revealed CD105 up-regulation in a wide range of tumour endothelia. Since 2002, endothelial CD105 expression has also been retrospectively investigated in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

An exhaustive literature review was performed to investigate available evidence on CD105 expression and its biological role and therapeutic potential in HNSCC.

RESULTS

The available evidence supports the hypothesis that CD105 expression in HNSCC may be a valuable parameter for pinpointing patients at greater risk of recurrent malignancy and with a worse prognosis. A high CD105 expression in HNSCC was associated with metastatic lymph nodes in most of the studies.

CONCLUSIONS

Prospective studies are mandatory to confirm that CD105 expression is a significant prognostic hallmark in HNSCC. The results of prospective studies could be relevant for the adoption of stricter follow-up protocols and/or alternative therapeutic regimens for patients with a high CD105 expression in HNSCC. Great interest is currently being focused on vascular targeting for therapeutic purposes. Preclinical studies on appropriate animal models resembling HNSCC to investigate the effects of inhibiting CD105 may show the efficacy of combined treatment strategies associating angiogenic-targeted with conventional therapies for HNSCC.

Clinical, pathological and molecular determinants in squamous cell carcinoma of the oral cavity

Squamous cell carcinoma of the oral cavity (OCSCC) is the most frequently observed form of head-and-neck cancer in Southeast Asia and is the sixth most common cancer worldwide. Most cases of this preventable disease are caused by alcohol consumption, smoking and betel nut chewing. The survival rates of patients with advanced OCSCC have not increased significantly in recent years. While treatments for OCSCC are similar worldwide, survival rates differ by geographical area. The various genetic profiles and individual genetic susceptibility for carcinogens may account for this discrepancy. In some respects, molecular alteration or accumulation affects tumor progression and the clinical outcomes among patients with OCSCC. Clarifying the tumor behavior of oral cancer, with regard to pathological features or molecular aspects, could help clinicians to judge, tailor and adopt more effective therapeutic strategies to treat oral cancer.

VEGF expression and angiogenesis in oral squamous cell carcinoma: an immunohistochemical and morphometric study

Angiogenesis is involved in tumor progression of oral squamous cell carcinoma (OSCC). In this study, we have investigated by immunohistochemistry vascular endothelial growth factor (VEGF) expression in tumor cells and we have correlated VEGF expression to microvessel area, evaluated by using CD105 as a marker of endothelial cells, in bioptic specimens of 54 human OSCC. Results demonstrated that VEGF is highly expressed in OSCC tumor specimens when compared to pre-neoplastic and normal tissues, without differences between the edge and inside the tumor. Moreover, VEGF expression is reduced in poor differentiated OSCC tumors when compared to moderate and good differentiated forms, and tumor microvessel area is higher in tumors when compared to pre-neoplastic lesions and normal tissues. Finally, VEGF and CD105 may be considered as reliable markers of tumor angiogenesis and progression in OSCC, even if we did not demonstrate any correlation between VEGF expression, tumor microvascular area, clinical stage, and lymph node status.

ALK5 phosphorylation of the endoglin cytoplasmic domain regulates Smad1/5/8 signaling and endothelial cell migration

Endoglin, an endothelial cell-specific transforming growth factor-beta (TGF-beta) superfamily coreceptor, has an essential role in angiogenesis. Endoglin-null mice have an embryonic lethal phenotype due to defects in angiogenesis and mutations in endoglin result in the vascular disease hereditary hemorrhagic telangiectasia type I. Increased endoglin expression in the proliferating endothelium of tumors has been correlated with metastasis, tumor grade and decreased survival. Although endoglin is thought to regulate TGF-beta superfamily signaling in endothelial cells through regulating the balance between two TGF-beta-responsive pathways, the activin receptor-like kinase 5 (ALK5)/Smad2/3 pathway and the activin receptor-like kinase 1 (ALK1)/Smad1/5/8 pathway, the mechanism by which endoglin regulates angiogenesis has not been defined. Here, we investigate the role of the cytoplasmic domain of endoglin and its phosphorylation by ALK5 in regulating endoglin function in endothelial cells. We demonstrate that the cytoplasmic domain of endoglin is basally phosphorylated by ALK5, primarily on serines 646 and 649, in endothelial cells. Functionally, the loss of phosphorylation at serine 646 resulted in a loss of endoglin-mediated inhibition of Smad1/5/8 signaling in response to TGF-beta and endothelial cell migration, whereas loss of phosphorylation at both serines 646 and 649 resulted in a loss of endoglin-mediated inhibition of Smad1/5/8 signaling in response to bone morphogenetic protein-9. Taken together, these results support endoglin phosphorylation by ALK5 as an important mechanism for regulating TGF-beta superfamily signaling and migration in endothelial cells.

The emerging role of TGF-beta superfamily coreceptors in cancer

The transforming growth factor beta (TGF-beta) signaling pathway plays a key role in different physiological processes such as development, cellular proliferation, extracellular matrix synthesis, angiogenesis or immune responses and its deregulation may result in tumor development. The TGF-beta coreceptors endoglin and betaglycan are emerging as modulators of the TGF-beta response with important roles in cancer. Endoglin is highly expressed in the tumor-associated vascular endothelium with prognostic significance in selected neoplasias and with potential to be a prime vascular target for antiangiogenic cancer therapy. On the other hand, the expression of endoglin and betaglycan in tumor cells themselves appears to play an important role in the progression of cancer, influencing cell proliferation, motility, invasiveness and tumorigenicity. In addition, experiments in vitro and in vivo in which endoglin or betaglycan expression is modulated have provided evidence that they act as tumor suppressors. The purpose of this review was to highlight the potential of membrane and soluble forms of the endoglin and betaglycan proteins as molecular targets in cancer diagnosis and therapy.

Independent prognostic relevance of microvessel density in advanced epithelial ovarian cancer and associations between CD31, CD105, p53 status, and angiogenic marker expression: A Gynecologic Oncology Group study

OBJECTIVES

The aims of this study were to examine prognostic significance of microvessel density (MVD) in previously-untreated, advanced epithelial ovarian cancer (EOC) and explore associations between MVD and factors that affect angiogenesis.

METHODS

MVD was determined by immunohistochemical expression of CD31 or CD105 in tumor sections from 106 women treated on GOG randomized phase III trials. Average MVD hotspots were quantified by light microscopy at high power (x400) and categorized as low (<upper quartile) or high (>or=upper quartile). Immunoblot expression of MASPIN, THBS-1, bFGF, VEGF, VEGFR-1 and p53 status (mutation and overexpression) was previously determined.

RESULTS

Of 106 evaluable cases, 25% exhibited high CD31-MVD (>24.25 vessels/high power field [HPF]) or high CD105-MVD (>19.25 vessels/HPF). After adjusting for age and stratifying by GOG performance status, stage, cell type, grade, debulking status and treatment regimen, high versus low CD105-MVD was associated with increased risk of disease progression (hazard ratio [HR]=1.873; 95% confidence interval [CI]: 1.102-3.184; p=0.020), but not death (HR=1.125; 95% CI: 0.654-1.935; p=0.670) whereas CD31-MVD was not associated with risk of disease progression (HR=1.578; 95% CI=0.918-2.711; p=0.099) or death (HR=1.678; 95% CI=0.957-2.943; p=0.071). CD31-MVD was correlated with CD105-MVD (p=0.001) and MASPIN (p=0.016). Neither CD31-MVD nor CD105-MVD was associated with p53 status, THBS-1, bFGF, VEGF or VEGFR-1.

CONCLUSIONS

High MVD assessed using CD105, a marker of proliferating endothelial cells and neoangiogenesis, but not CD31 a pan-endothelial marker, appeared to be an independent prognostic factor for worse progression-free survival in women with advanced EOC after adjusting for prognostic clinical covariates.

Clinical significance of osteopontin expression in T1 and T2 tongue cancers

BACKGROUND

Osteopontin (OPN) is considered to be a tumor-related protein associated with tumor aggressiveness and metastasis.

METHODS

Immunohistochemistry was used to study the clinical significance of OPN expression in T1 and T2 tongue cancers.

RESULTS

Positive OPN expression significantly correlated with higher tumor classification (T) (p = .004), positive nodal classification (N) (p < .001), greater tumor thickness (p < .001), and presence of tumor necrosis (p = .016), respectively. The unfavorable cumulative 5-year disease-free survival rate significantly correlated with positive OPN expression (p < .001), T2 (p = .024), positive N (p < .001), greater tumor thickness (p = .023), and positive tumor necrosis (p = .003). However, taking CD105 into consideration, only CD105 expression was the independent prognostic factor for survival by Cox's regression analysis.

CONCLUSION

Overexpression of OPN in the tumors implicated a more aggressive tumor behavior and was an important factor for survival. In addition, there might be relationship between OPN and CD105 expressions in angiogenesis.

VEGF and ki 67 expression in squamous cell carcinoma of the tongue: An immunohistochemical and computerized image analysis study

Over-expression of ki 67 and vascular endothelial growth factor (VEGF) is a frequent finding in squamous cell carcinoma (SCC) of the oral mucosa. The expression of VEGF and ki 67 proteins was studied in a cohort of 87 patients with primary, previously untreated SCC of the tongue, using computerized image analysis (CIA) in order to determine the potential prognostic significance of these factors. Immunohistochemical analysis was performed with monoclonal anti-ki 67 (MIB 1) and anti-VEGF antibodies. A digital image analysis assay was applied for the evaluation of the results. Using CIA, VEGF over-expression was observed in 24/87 (27.5%) of the examined cases and this finding correlated to the stage of the disease (p=0.05). ki 67 was over-expressed in 49/87 (56.3%) of the cases and correlated to the size of the tumors (p=0.05). Cox regression analysis showed that there was no prognostic significance associating VEGF protein expression to survival status of the examined patients (p=0.77), whereas ki 67 over-expression was strongly correlated to poor prognosis (p=0.017). The size of the primary tumors was also strongly correlated to survival status of the patients (p=0.024), whereas stage of disease showed a borderline statistical significance (p=0.091).

The prognostic value of hypoxia markers in T2-staged oral tongue cancer

Tumor hypoxia is associated with poorer outcome in patients with head and neck carcinomas, but little is known about hypoxia biomarkers in oral tongue cancer. We evaluated whether hypoxia biomarkers and clinicopathologic variables were prognostic predictors in patients with T2-staged squamous cell carcinoma (SCC) of the oral tongue. Tissue microarrays were constructed from formalin-fixed tumor blocks of 43 patients with T2-staged tongue SCCs treated by surgical resection and neck dissection. Tissue samples were stained with monoclonal antibodies to hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase (CA)-9, glucose transporter (GLUT)-1, and erythropoietin receptor (EPOR). Locoregional control and survival rates were calculated by the Kaplan-Meier method, and prognostic factors were calculated from uni- and multivariate analyses. Tumor thickness was correlated with expression of CA-9 and GLUT-1 and nodal classification was correlated with GLUT-1 expression. The nodal metastasis rate was 51%, and the 5-year locoregional control and disease-specific survival (DSS) rates were 59% and 69%, respectively. Univariate analysis showed that HIF-1alpha and EPOR expression were significantly related to DSS. Multivariate analysis showed that EPOR expression was an independent predictor of DSS (P=0.030). EPOR expression may be an independent predictor for DSS in patients with T2-staged SCC of the oral tongue.

Endoglin (CD105): a marker of tumor vasculature and potential target for therapy

Endoglin (CD105) is an accessory protein of the transforming growth factor-beta receptor system expressed on vascular endothelial cells. Mutation of the endoglin gene is associated with hereditary hemorrhagic telangiectasias, or Osler-Weber-Rendu syndrome, and has been studied extensively in the context of this disease. The expression of endoglin is elevated on the endothelial cells of healing wounds, developing embryos, inflammatory tissues, and solid tumors. Endoglin is a marker of activated endothelium, and its vascular expression is limited to proliferating cells. Recent studies identified endoglin expression in several solid tumor types, with the level of expression correlating with various clinicopathologic factors including decreased survival and presence of metastases. Attempts to target endoglin and the cells that express this protein in tumor-bearing mice have yielded promising results.