Metalloproteinase-9 immunoexpression and angiogenesis in thyroid follicular neoplasms: relation to clinical and histopathologic features

Assessment of Biomarkers for Clinical Diagnosis of Papillary Thyroid Carcinoma with Distant Metastasis

Early diagnosis and treatment of thyroid cancers are critical for better prognosis and better survival rates. The purpose of this study was to identify potential diagnostic markers for papillary thyroid carcinomas with distant metastasis. Fifty-eight papillary thyroid tumor specimens (27 papillary thyroid carcinomas with distant metastasis and 31 without metastasis) were examined, and protein expression of pituitary tumor-transforming gene (PTTG), E-cadherin, p27kip1, vascular endothelial growth factor (VEGF)-C, metalloproteinase (MMP) 2, MMP9, chemokine receptor CXCR4, and basic fibroblast growth factor (bFGF) in these tumors was assessed by immunohistochemistry. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and their diagnostic values were evaluated by ROC curve analysis. PTTG, VEGF-C, MMP2, MMP9, CXCR4, and bFGF were overexpressed in metastatic papillary thyroid carcinomas, whereas p27kip1 expression was elevated only in carcinomas lacking metastasis. Multiple-factor binary ordinal logistic regression analysis revealed that PTTG, VEGF-C, MMP2, and bFGF were independently related to biological metastatic behavior in thyroid tumors, suggesting their potential use as biomarkers. ROC curve analysis showed that among these four proteins, VEGF-C and bFGF were the best diagnostic biomarkers. A VEGF-C and bFGF cluster was the most useful factor for the differential diagnosis between metastatic and non-metastatic papillary thyroid cancers. Thus, the combined use of VEGF-C and bFGF as biomarkers may improve the diagnostic accuracy of papillary thyroid carcinoma and may be useful in multimodal screening programs for the clinical diagnosis of papillary thyroid carcinoma and early detection of papillary thyroid carcinoma with distant metastasis.

Thyroid nodules: pathophysiological insight on oncogenesis and novel diagnostic techniques

Thyroid nodules are a very frequent pathology among common population. Despite the vast majority of them are of benign origin, the incidence of thyroid cancer is currently rather rising. Although there are several risk factors of thyroid cancer and several clinical, ultrasound, biochemical and molecular diagnostic markers, the exact mechanisms of thyroid oncogenesis and the linkage between thyroid nodule ultrasound appearance and its biological character remain unclear. While ionizing radiation is the only one well-known risk factor for thyroid cancer, the significance of some others remains unclear. The aim of our review was to discuss some not completely known pathophysiological mechanisms involved in thyroid oncogenesis as hypothyroidism, mutations of genes regulating cell proliferation, thyroid autoimmunity and pregnancy and to describe pathophysiological background of some ultrasound markers of thyroid cancer (size, echogenicity, vascularization, calcifications and stiffness). Better knowledge in this field is crucial for development of novel diagnostic techniques and therapeutic approaches. For example, the analysis of BRAF, RAS and other mutations in cytological samples may help to distinction between follicular thyroid carcinoma and follicular thyroid adenoma and may significantly decrease the number of unnecessary surgery among patients with thyroid nodules. Alternatively, the different malign cells growth, angiogenesis, destructions of thyroid follicles, reparative changes, growth retardation, fibrosis and increased interstitial fluid pressure implicate the typical ultrasound appearance of papillary thyroid cancer (hypoechogenicity, irregular vascularization, microcalcifications, stiffness) which is essential to catch the suspicious nodules on the basis of their ultrasound appearance among large amount of benign nodules.

VEGF expression, microvessel density and dendritic cell decrease in thyroid cancer

Thyroid cancer is one of the five most common cancers in the age between 20 and 50 years. Many factors including the potent angiogenic vascular endothelial growth factor (VEGF) and different dendritic cell types are known to be related to thyroid tumourogenesis. The study was performed to address the expression of VEGF and microvessel density in thyroid cancers and to evaluate the effect of VEGF expression in thyroid tumour cells on the dendritic cells. We investigated 65 patients with different types of thyroid carcinomas: papillary (PTC), oncocytic (OTC), follicular (FTC) and anaplastic (ATC), immunohistochemically with antibodies against VEGF, CD1a, CD83, S100 and CD31. Our results suggest that the expression of VEGF is significantly more often in PTC than ATC (92.3% vs. 60.0%, p = 0.025). The microvessel density marked with CD31 in the tumour border of PTC was significantly higher as compared to FTC (p = 0.039), but not to ATC and OTC (p = 0.337 and 0.134). We found that CD1a- and CD83-positive cells were dispersed with variable density and in OC CD31⁺ vessel numbers were positively correlated with CD83⁺ dendritic cells in tumour stroma (R = 0.847, p = 0.016). We did not find statistically significant associations of the survival of patients with PTC after the surgical therapy with VEGF expression and MVD. In conclusion we may state that VEGF expression in tumour cells of thyroid cancer can induce neovascularization and suppress dendritic cells.

Down-regulation of matrix metalloproteinase-7 inhibits metastasis of human anaplastic thyroid cancer cell line

Epigenetic drugs such as histone deacetylase inhibitors (HDACIs) possess anticancer properties due to its ability to regulate genes associated with tumor growth, differentiation, apoptosis and metastasis. In addition to its apoptotic effect, phenylbutyrate (PB), a carboxylic acid HDACI, inhibited an anaplastic (ATC) thyroid cancer cell line ARO from penetrating a matrigel coated transwell with concomitant suppression of a metastasis-associated gene, matrix metalloproteinase-7 (MMP-7) and stimulation of a transformation suppressor protein, reversion-inducing- cysteine-rich protein with Kazal motifs without affecting MMP-2 expression levels. Direct evidence suggesting MMP-7 down-regulated cancer metastasis came from the observation of a decreased pulmonary metastasis in SCID mice xeno-transplanted with MMP-7-knocked-down ARO cells. In addition, H-89, a protein kinase A inhibitor, remarkably restored the down-regulaed MMP-7 level treated by PB. Thus, the suppressive effect of PB on MMP-7 was partially carried out through H3 phosphoacetylation. To conclude, our findings suggest PB inhibits MMP-7 expression epigenetically through phosphoacetylation of histone proteins, and thereby, reduced invasive ability of an ATC thyroid cancer cell line.

Angiogenesis in Malignant Thyroid Tumors

It is well known that radiation significantly impacts the morbidity of thyroid cancer and that is why Belarus has the highest incidence of the malignancy. Author describes statistical data, classification of angiogenesis, and typical pathological features of malignant thyroid diseases with regard to the vascular network.

Expression of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in medullary thyroid carcinoma: prognostic implications

BACKGROUND

Metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 2 (TIMP-2) participate in the degeneration of the extracellular matrix and are associated with carcinogenesis. MMP-2 is one of the main metalloproteinases active in neoplasia and is a marker of the malignant phenotype. Since the biological behavior of medullary thyroid carcinoma (MTC) varies widely, the present study was undertaken to determine if there is a correlation between the clinical evolution of MTC and the immunohistochemically detected expression of these enzymes in thyroid surgical specimens containing MTC. If so, their expression would be a novel indicator of the prognosis of MTC.

METHODS

Thirty-seven patients with MTC who had undergone thyroid surgery were followed for an average of 73 months. Immunohistochemical staining for metalloproteinase-related enzymes was performed in surgical paraffin blocks. The clinical status of the patients after surgery and at the end of the study period was characterized to determine correlations between these and the immunohistochemical markers. A value of p < 0.05 was considered statistically significant.

RESULTS

At the end of the study period, 15 patients (40.5%) were alive and without evidence of MTC, 17 (45.9%) had persistent MTC, and 5 (13.5%) had a relapse of their neoplasia. Four patients (10.8%) died during the course of the study. There was a significant correlation (p = 0.0005) between the immunohistochemical staining for MMP-2 and the clinical condition of the patients at the end of the study period, and a correlation between the state of apparent cure compared to persistence of MTC after thyroid surgery (p = 0.0207). No significant correlations were observed between either TIMP-2 expression or immune marking of metastatic lymph nodes and the clinical variables studied.

CONCLUSION

Immunohistochemical expression of MMP-2 in thyroid surgical specimens from patients with MTC is a novel indicator of the prognosis of this cancer.

E-cadherin, MMP-2, and MMP-9 as prognostic markers in penile cancer: analysis of 125 patients

OBJECTIVES

The treatment of choice for invasive penile carcinoma is amputation and lymphadenectomy. The latter is associated with a high morbidity rate. Analysis of new prognostic factors such as E-cadherin, matrix metalloproteinase (MMP)-2, and MMP-9 may help to select candidates for lymphadenectomy.

METHODS

We assessed 125 patients with penile epidermoid carcinoma treated with amputation and bilateral lymphadenectomy. The following factors were analyzed: age, race, disease evolution time, venereal background, clinical and pathologic stage, tumor thickness, differentiation grade, venous and lymphatic embolization, koilocytosis, type of invasion, and E-cadherin, MMP-2, and MMP-9 immunoreactivity. The value of risk factors for lymph node metastases and specific survival was assessed.

RESULTS

The mean follow-up was 76.5 months. Clinical N stage (P = 0.001), tumor thickness (P = 0.027), lymphatic permeation (P < 0.001), venous embolization (P = 0.002), corpus cavernosum infiltration (P = 0.002), and low E-cadherin expression (P = 0.032) significantly correlated with the presence of metastases. Independent risk factors for metastases were lymphatic permeation (relative risk [RR] = 5.99; 95% confidence interval [CI] 2.1 to 16.9) and clinical N stage (RR = 5.5; 95% CI = 1.9 to 16.7). Lymph node metastases (RR = 57.9; 95% CI = 7.4 to 453.9), urethral infiltration (RR = 3.5; 95% CI = 1.3 to 9.2), and MMP-9 immunoreactivity (RR = 3.2; 95% CI = 1.2 to 8.3) were considered independent risk factors for disease recurrence.

CONCLUSIONS

On univariate analysis, low E-cadherin immunoreactivity was associated with a greater risk of lymph node metastases. High MMP-9 immunoreactivity was an independent risk factor for disease recurrence.

Expression of c-kit, Flk-1, and Flk-2 receptors in benign and malignant tumors of follicular epithelial origin

BACKGROUND

Vascular endothelial growth factor (VEGF) is a key regulator of physiologic as well as pathologic angiogenesis. The response of VEGF to endothelial cell mitogenesis and survival, as well as angiogenesis and microvascular permeability, is mainly mediated through its receptor-2, VEGFR2 (kinase domain receptor or fetal liver kinase-1, KDR or Flk-1). This study aimed to detect the expression of VEGFR2 in various forms of thyroid tumors. In addition, the expression of Flk-2 (receptor for Flt-3) and c-Kit (receptor for steel locus factor), which shows strong similarity to Flk-1, was also examined in thyroid tumors.

METHODS

RT-PCR analyses of c-Kit and immunohistochemical staining of c-Kit, Flk-1, and Flk-2 were performed in archived samples of 18 papillary thyroid carcinoma (PTC), 9 follicular thyroid carcinoma (FTC), 12 follicular adenoma (FA), and 7 nodular goiter (NG) samples. The data were correlated to clinicopathologic features.

RESULTS

By RT-PCR analyses, c-Kit expression was detected in 22% (4/18) of PTC, 22% (2/9) of FTC, 25% (3/12) of FA, and 57% (4/7) of NG samples. However, positive immunostaining signals of c-Kit were only observed in 17% (3/18) of PTC samples, and not in the others. Similarly, Flk-1 expression was only detected by immunohistochemistry in 67% (12/18) of PTC and 43% (3/7) of NG samples, and not in the others. Interestingly, the expression of Flk-2 was found in 89% (16/18) of PTC, 89% (8/9) of FTC, 75% (9/12) of FA, and 29% (2/7) of NG samples. An inverse relationship of thyroid cancer size with Flk-2 expression was found.

CONCLUSION

Flk-2 expression was detected in various forms of thyroid tumors and increased Flk-2 expression was correlated with thyroid tumors with increased transforming activity, suggesting that Flk-2 is involved in pathogenic development of thyroid malignancy. Similarly, Flk-1 expression was also found in some thyroid tumors, while the expression of c-Kit-mediated pathways may not play a major role in thyroid tumorigenesis.

Angiogenesis in benign and malignant thyroid disease

CONTEXT

Angiogenesis has been recognized as an important process contributing to the pathophysiology of many benign and malignant diseases. It is not surprising, therefore, that this complex process is proving to be an important regulator of both benign and malignant disease processes in the thyroid gland. This paper will review the general principles of angiogenesis and lymphangiogenesis, as well as the importance of the balance between angiogenic stimulators and inhibitors in the normal thyroid gland. We will also review how this balance is disturbed in benign and malignant thyroid conditions. Finally, we will address the role manipulation of this process may play in the development of novel treatment strategies for diseases of the thyroid.

OBJECTIVE

To review the literature concerning the role of angiogenesis in the thyroid gland.

CONCLUSIONS

Angiogenesis is an important process which has been shown to be involved in the pathophysiology of benign and malignant diseases of the thyroid gland. Manipulation of this process holds great promise for the development of novel treatments for these disorders. As the mechanisms regulating angiogenesis in the thyroid become increasingly clear, researchers will come ever closer to turning this promise into clinical reality.

Angiogenesis as an indicator of metastatic potential in papillary thyroid carcinoma

Angiogenesis is new blood vessel formation, a process that can lead to tumor development. Microvessel count has been correlated to metastasis in some neoplasias.

PURPOSE

To determine if measurement of microvessel density is useful in predicting metastasis to the cervical lymph node and prognosis in patients with papillary thyroid carcinoma.

METHODS

A retrospective analysis was performed in 30 patients that had undergone total thyroidectomy. They were divided in 2 groups of 15 patients--with and without metastatic disease. Immunohistochemistry was used to detect expression of CD34 in archival paraffin-embedded papillary thyroid tumors, and microvessel density was calculated based on it. Association between microvessel density and the presence of metastasis, according to histological subtype, disease recurrence, and AMES prognostic index groups was determined through statistical analysis.

RESULTS

The median microvessel density for the patient group without metastasis (200.0 microvessels/mm2) was apparently, but not significantly, less than that observed among metastatic disease patients (254.4 microvessels/mm2) (P=.20). When papillary carcinoma subtypes were analyzed, this difference became significant (P=02). The follicular variant exhibited a greater microvessel density than the other subtypes, independent of metastasis presence. There was an apparent, but not significant, tendency for a larger median microvessel density in the group of patients that presented recurrence (294.4 microvessels/mm2 vs 249.6 microvessels/mm2, P=.11). There was no relationship between risk level and microvessel density: in the low- and high-risk groups, the median MVD was 304.0 microvessels/mm2 and 229.6 microvessels/mm2, respectively (P=.27).

CONCLUSIONS

The results suggest that angiogenesis is more intense among metastatic tumors in the classic and the tall cell variants, indicating that microvessel count can be an indicator of the potential for metastasis in these subtypes of papillary thyroid carcinoma. Patients that developed recurrent disease had a tendency to exhibit higher angiogenesis; however, there was no association between microvessel density and the AMES prognostic index.

Matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases and angiogenic cytokines in peripheral blood of patients with thyroid cancer

Stimulation of growth of endothelial cells from preexisting blood vessels, i.e., angiogenesis, is one of the essential elements necessary to create a permissive environment in which a tumor can grow. During angiogenesis, the matrix metalloproteinase (MMP) family of tissue enzymes contributes to normal (embriogenesis or wound repair) and pathologic tissue remodeling (chronic inflammation and tumor genesis). The proposed pathogenic roles of MMPs in cancer are tissue breakdown and remodeling during invasive tumor growth and tumor angiogenesis. Tissue inhibitors of metalloproteinases (TIMPs) form a complex with MMPs, which in turn inhibits active MMPs. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are unique among mediators of angiogenesis with synergistic effect, and both can also be secreted by thyroid cancer cells. The goal of the study was to evaluate the plasma blood concentration of VEGF, bFGF, MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1, and TIMP-2 in patients with cancer and in normal subjects. Twenty-two patients with thyroid cancers (papillary cancer, 11; partly papillary and partly follicular cancer, 3; anaplastic cancer, 5; medullary cancer, 3) and 16 healthy subjects (controls) were included in the study. VEGF, bFGF MMPs, and TIMPs were evaluated by enzyme-linked immunosorbent assay (ELISA). In patients with thyroid cancer, normal VEGF concentrations (74.29 +/- 13.38 vs. 84.85 +/- 21.71 pg/mL; p > 0.05) and increased bFGF (29.52 +/- 4.99 vs. 6.05 +/- 1.43 pg/mL; p < 0.001), MMP-2 (605.95 +/- 81.83 vs. 148.75 +/- 43.53 ng/mL; p < 0.001), TIMP-2 (114.19 +/- 6.62 vs. 60.75 +/- 9.18 ng/mL; p < 0.001), as well as lower MMP-1 (0.70 +/- 0.42 vs. 3.87 +/- 0.53; p < 0.001) levels have been noted. Increased plasma levels of MMP-3 and MMP-9 were also found in patients with medullary carcinoma. In conclusion, predominance of MMP-2 over TIMP-2 and TIMP-1 over MMP-1 as well as increased concentration of bFGF in peripheral blood are common features in patients with thyroid cancer.