CXCR4 expression correlates with the degree of tumor infiltration and BRAF status in papillary thyroid carcinomas

The prognostic significance of CXCR4 and SDF-1 in differentiated thyroid cancer depends on CD8+ density

BACKGROUND

Tumor infiltration with cytotoxic CD8+ T-cells is associated with a favorable outcome in several neoplasms, including thyroid cancer. The chemokine axis CXCR4/SDF-1 correlates with more aggressive tumors, but little is known concerning the prognostic relevance in relation to the tumor immune microenvironment of differentiated thyroid cancer (DTC).

METHODS

A tissue microarray (TMA) of 37 tumor specimens of primary DTC was analyzed by immunohistochemistry (IHC) for the expression of CD8+, CXCR4, phosphorylated CXCR4 and SDF-1. A survival analysis was performed on a larger collective (n = 456) at RNA level using data from The Cancer Genome Atlas (TCGA) papillary thyroid cancer cohort.

RESULTS

Among the 37 patients in the TMA-cohort, the density of CD8+ was higher in patients with less advanced primary tumors (median cells/TMA-punch: 12.5 (IQR: 6.5, 12.5) in T1-2 tumors vs. 5 (IQR: 3, 8) in T3-4 tumors, p = 0.05). In the TCGA-cohort, CXCR4 expression was higher in patients with cervical lymph node metastasis compared to N0 or Nx stage (CXCR4^high/low 116/78 vs. 97/116 vs. 14/35, respectively, p = 0.001). Spearman's correlation analysis of the TMA-cohort demonstrated that SDF-1 was significantly correlated with CXCR4 (r = 0.4, p = 0.01) and pCXCR4 (r = 0.5, p = 0.002). In the TCGA-cohort, density of CD8+ correlated with CXCR4 and SDF-1 expression (r = 0.58, p < 0.001; r = 0.4, p < 0.001). The combined marker analysis of the TCGA cohort demonstrated that high expression of both, CXCR4 and SDF-1 was associated with reduced overall survival in the CD8 negative TCGA cohort (p = 0.004).

CONCLUSION

These findings suggest that the prognostic significance of CXCR4 and SDF-1 in differentiated thyroid cancer depends on the density of CD8 positive T-lymphocytes. Further studies with larger sample sizes are needed to support our findings and inform future investigations of new treatment and diagnostic options for a more personalized approach for patients with differentiated thyroid cancer.

Comparative evaluation of somatostatin and CXCR4 receptor expression in different types of thyroid carcinoma using well-characterised monoclonal antibodies

Background

Papillary and follicular thyroid carcinomas can be treated surgically and with radioiodine therapy, whereas therapeutic options for advanced stage IV medullary and for anaplastic tumours are limited. Recently, somatostatin receptors (SSTs) and the chemokine receptor CXCR4 have been evaluated for the treatment of thyroid carcinomas, however, with contradictory results.

Methods

The expression of the five SSTs and of CXCR4 was assessed in 90 samples from 56 patients with follicular, papillary, medullary, or anaplastic thyroid carcinoma by means of immunohistochemistry using well-characterised monoclonal antibodies. The stainings were evaluated using the Immunoreactivity Score (IRS) and correlated to clinical data. In order to further substantiate the immunohistochemistry results, in serial sections of a subset of the samples receptor expression was additionally examined at the mRNA level using qRT-PCR.

Results

Overall, SST and CXCR4 protein expression was low in all four entities. In single cases, however, very high IRS values for SST2 and CXCR4 were observed. SST2 was the most frequently expressed receptor, found in 38% of cases, followed by SST5 and SST4, found in 14 and 9% of tumours, respectively. SST1 and SST3 could not be detected to any significant extent. CXCR4 was present in 12.5% of medullary and 25% of anaplastic carcinomas. Expression SST3, SST4, SST5 and CXCR4 was positively correlated with expression of the proliferation marker Ki-67. Additionally, a negative interrelationship between SST4 or SST5 expression and patient survival and a positive association between SST3 expression and tumour diameter were observed. qRT-PCR revealed a similar receptor expression pattern to that seen at the protein level. However, probably due to the low overall expression, no correlation was found for the SSTs or the CXCR4 between the IRS and the mRNA values.

Conclusions

SST- or CXCR4-based diagnostics or therapy in thyroid carcinomas should not be considered in general but may be feasible in single cases with high levels of expression of these receptors.

CCL18 Knockdown Suppresses Cell Growth and Migration in Thyroid Cancer

BACKGROUND

Chemokine (C-C motif) ligand 18 (CCL18) is a chemokine that plays a key role in immune and inflammatory responses. In recent years, CCL18 participates in the development and progression of various cancers, but its expression and role in thyroid cancer (TC) remain unclear.

METHODS

RT-qPCR assay and Western blot assay were used to explore the expression level of CCL18 in TC tissues and cells. Cell proliferation was measured by MTT assay. Transwell assay was adopted to detect cell migration in TC cells. Dual luciferase reporter assay was performed to assess the relationship between CCL18 and miR-149-5p.

RESULTS

There was an uptrend of CCL18 in TC tissues and cells. Our findings indicated that CCL18 overexpression facilitated lymph node metastasis in patients with TC. CCL18 silencing was found to inhibit cell migration, proliferation, and EMT progression in TC cells. CCL18 was proved to be a target gene of miR-149-5p. Additionally, miR-149-5p weakened the effect of CCL18 in the progression of TC.

CONCLUSION

Therefore, our results indicated that CCL18 knockdown restrained TC progression and suggested that CCL18 might be a potential therapeutic target for TC.

Sex Bias in Differentiated Thyroid Cancer

Differentiated thyroid cancers are more frequent in women than in men. These different frequencies may depend on differences in patient's behavior and in thyroid investigations. However, an impact on sexual hormones is likely, although this has been insufficiently elucidated. Estrogens may increase the production of mutagenic molecules in the thyroid cell and favor the proliferation and invasion of tumoral cells by regulating both the thyrocyte enzymatic machinery and the inflammatory process associated with tumor growth. On the other hand, the worse prognosis of thyroid cancer associated with the male gender is poorly explained.

Clinical association of CXCR4 in primary tumor of papillary thyroid cancer and response to iodine-131 treatment

OBJECT

Papillary thyroid cancer (PTC) has an excellent prognosis. However, patients with such, if refract to radioiodine treatment, increase recurrent and mortality rates. Tumor aggressiveness in primary tumor of PTC expresses CXCR4 chemokine receptor. Thus, CXCR4 expression of the tumor may predict response to radioiodine treatment.

MATERIALS AND METHODS

Retrospective review of seventy-four PTC patients, treated with total/near-total thyroidectomy and radioiodine treatment at King Chulalongkorn Memorial Hospital from January 2007 to 2013, were classified as non-radioiodine-refractory (non-RAIR) or RAIR treatment response. All histopathologic diagnoses were reviewed and paraffin blocks were retrieved for CXCR4 immunostaining, determined by automated digital imaging analysis for intensity and extension. The scores were compared between primary tumour and adjacent normal thyroid tissue as well as between the tissue of non-RAIR and that of RAIR. Factors determining type of RAI response were analyzed.

RESULTS

CXCR4 immunostaining scores of PTC is significantly higher than normal thyroid [2.03 (0.52) and 1.48 (0.75)] [mean (SD)] (P = 0.0001). CXCR4 immunostaining scores in RAIR are potentially higher than non-RAIR [1.95 (0.54) and 2.13 (0.47) (P = 0.149)]. Odds ratio of CXCR4 immunostaining score for predicting RAIR treatment is 1.99 (P = 0.150). CXCR4 immunostaining scores positively associate with tumor size (R = 0.298, P = 0.01); whereas no significant association with other clinicopathologic factors.

CONCLUSION

Our data support the notion that CXCR4 are significantly expressed in PTC tumor over normal thyroid tissues. However, there is no clinical association with radioiodine treatment response.

Chemokines and their Receptors: Multifaceted Roles in Cancer Progression and Potential Value as Cancer Prognostic Markers

Chemokines are chemotactic cytokines that mediate immune cell chemotaxis and lymphoid tissue development. Recent advances have indicated that chemokines and their cognate receptors play critical roles in cancer-related inflammation and cancer progression. On the basis of these findings, the chemokine system has become a new potential drug target for cancer immunotherapy. In this review, we summarize the essential roles of the complex network of chemokines and their receptors in cancer progression. Furthermore, we discuss the potential value of the chemokine system as a cancer prognostic marker. The chemokine system regulates the infiltration of immune cells into the tumor microenvironment, which induces both pro- and anti-immunity and promotes or suppresses tumor growth and proliferation, angiogenesis, and metastasis. Increasing evidence indicates the promising prognostic value of the chemokine system in cancer patients. While CCL2, CXCL10, and CX3CL1/CX3CR1 can serve as favorable or unfavorable prognostic factors depending on the cancer types, CCL14 and XCL1 possess good prognostic value. Other chemokines such as CXCL1, CXCL8, and CXCL12 are poor prognostic markers. Despite vast advances in our understanding of the complex nature of the chemokine system in tumor biology, knowledge about the multifaceted roles of the chemokine system in different types of cancers is still limited. Further studies are necessary to decipher distinct roles within the chemokine system in terms of cancer progression and to validate their potential value in cancer prognosis.

The multifaceted anti-cancer effects of BRAF-inhibitors

The BRAF gene is commonly involved in normal processes of cell growth and differentiation. The BRAF (V600E) mutation is found in several human cancer, causing an increase of cell proliferation due to a modification of the ERK/MAPK-signal cascade. In particular, BRAFV600E mutation is found in those melanoma or thyroid cancer refractory to the common therapy and with a more aggressive phenotype. BRAF V600E was found to influence the composition of the so-called tumour microenvironment modulating both solid (immune-cell infiltration) and soluble (chemokines) mediators, which balance characterize the ultimate behaviour of the tumour, making it more or less aggressive. In particular, the presence of BRAFV600E mutation would be associated with a change of this balance to a more aggressive phenotype of the tumour and a worse prognosis. The investigation of the possible modulation of those components of tumour microenvironment is nowadays object of several studies as a new potential target therapy in those more complicated cases. At present several clinical trials both in melanoma and thyroid cancer are using BRAF-inhibitors with encouraging results, which are derived also from numerous in vitro pre-clinical studies aimed at evaluate the possible modulation of immune-cell density and of specific pro-tumorigenic chemokine secretion (CXCL8 and CCL2) by several BRAF-inhibitors in the context of melanoma and thyroid cancer. This review will encompass in vitro and in vivo studies which investigated the modulation of the tumour microenvironment by BRAF-inhibitors, highlighting also the most recent clinical trials with a specific focus on melanoma and thyroid cancer.

Quercetin inhibits NTHi-triggered CXCR4 activation through suppressing IKKα/NF-κB and MAPK signaling pathways in otitis media

Otitis media is one of the most common bacterial infections in children, contributing to hearing loss. A vital bacterial pathogen leading to otitis media development is the nontypeable Haemophilus influenzae (NTHi). Inflammation response is reported as an important characristic for otitis media. Chemokine CXC receptor 4 (CXCR4) is a 352-amino acid seven-span transmembrane G-protein coupled receptor, essential for inflammatory response. However, the possible molecular mechanism indicating the alteration of CXCR4 modulated by NTHi is poorly known. In the present study, NTHi enhanced CXCR4 expression through phosphorylation of IKKα and p38, which relied on nuclear factor-κB (NF-κB) translocation in vitro as well as in the middle ear of mice in vivo. Previously, quercetin, a natural production mainly isolated from rutin, has shown anti-inflammatory effects. Here, we report that quercetin suppressed NTHi-induced CXCR4 expression levels in vitro and in vivo. Quercetin blocked CXCR4 activation through direct IKKβ phosphorylation inhibition, as well as of p38 MAPK restraining. Hence, identification of quercetin may be a potential therapeutic strategy for treating otitis media induced by NTHi through inflammation suppression.

Clinicopathological significance of chemokine receptor CXCR4 expression in papillary thyroid carcinoma: a meta-analysis

INTRODUCTION

Emerging evidence indicates that C-X-C chemokine receptor type 4 (CXCR 4) is a candidate oncogene in several types of human tumors including papillary thyroid carcinoma (PTC). To investigate its expression impact on clinicopathological features, a meta-analysis was performed.

EVIDENCE ACQUISITION

A comprehensive search in the PubMed, Embase and The Cochrane Library (up to March 14, 2017) was performed for relevant studies using multiple search strategies. Methodological quality of the studies was also evaluated. Odds ratios (ORs) were calculated and summarized.

EVIDENCE SYNTHESIS

Final analysis was performed of 661 PTC patients from 8 eligible studies. The pooled OR indicated that CXCR4 expression was significantly higher in PTC than that in normal thyroid tissue and benign thyroid nodule (NTT/BTN) (OR=67.22, 95% CI: 32.85-137.55, P<0.00001). In subgroup analysis, CXCR4 expression was associated with age (OR=1.55, 95% CI: 1.02-2.34, P=0.04), lympaocytic thyroiditis (OR=1.68, 95% CI: 1.06-2.67, P=0.03); CXCR4 expression was not found to be associated with gender (OR=1.02, 95% CI: 0.66-1.58, P=0.93), multiple (OR=0.91, 95% CI: 0.55-1.53, P=0.73), lymph node metastatic (LNM) (OR=1.98, 95% CI: 0.88-4.47, P=0.10) and TNM stage (OR=2.00, 95% CI: 0.49-8.16, P=0.34). A sensitivity analysis found out the study by Zhu et al. which impacted the pooled OR, after removing this study, a positive and relatively stable result conformed that CXCR4 expression was associated to LNM.

CONCLUSIONS

The results of this meta-analysis suggest that CXCR4 expression is frequent and cancer-specific event in PTC.

RET-mediated modulation of tumor microenvironment and immune response in multiple endocrine neoplasia type 2 (MEN2)

Medullary thyroid carcinomas (MTC) arise from thyroid parafollicular, calcitonin-producing C-cells and can occur either as sporadic or as hereditary diseases in the context of familial syndromes, including multiple endocrine neoplasia 2A (MEN2A), multiple endocrine neoplasia 2B (MEN2B) and familial MTC (FMTC). In a large fraction of sporadic cases, and virtually in all inherited cases of MTC, activating point mutations of the RET proto-oncogene are found. RET encodes for a receptor tyrosine kinase protein endowed with transforming potential on thyroid parafollicular cells. As in other cancer types, microenvironmental factors play a critical role in MTC. Tumor-associated extracellular matrix, stromal cells and immune cells interact and influence the behavior of cancer cells both in a tumor-promoting and in a tumor-suppressing manner. Several studies have shown that, besides the neoplastic transformation of thyroid C-cells, a profound modification of tumor microenvironment has been associated to the RET FMTC/MEN2-associated oncoproteins. They influence the surrounding stroma, activating cancer-associated fibroblasts (CAFs), promoting cancer-associated inflammation and suppressing anti-cancer immune response. These mechanisms might be exploited to develop innovative anti-cancer therapies and novel prognostic tools in the context of familial, RET-associated MTC.

CXCR4 polymorphism predicts progression-free survival in metastatic colorectal cancer patients treated with first-line bevacizumab-based chemotherapy

We analyzed associations between CXCR4/CXCL12 single-nucleotide polymorphisms and outcomes in metastatic colorectal cancer (mCRC) patients who underwent first-line bevacizumab-based chemotherapy. A total of 874 patients were included in this study: 144 treated with bevacizumab and FOLFOX or XELOX (training cohort), 653 treated with bevacizumab and FOLFIRI or FOLFOXIRI (validation cohort A or B) and 77 treated with cetuximab- and oxaliplatin-based regimens (control cohort). One CXCR4 polymorphism (rs2228014) and two CXCL12 polymorphisms (rs1801157 and rs3740085) were analyzed by PCR-based direct sequencing. Patients with a C/C genotype had a prolonged progression-free survival (PFS) compared with those with any T allele (P=0.030) in the training cohort. Similarly, patients with the C/C genotype had a superior PFS in the validation cohorts, but not in the control cohort. Our findings suggest that a common genetic variant, CXCR4 rs2228014, could predict PFS and may guide therapeutic decisions in mCRC patients receiving first-line bevacizumab-based chemotherapy.

The Role of Chemokines in Thyroid Carcinoma

The global incidence of thyroid cancer is increasing, and metastatic spread to the lymph nodes is common in papillary thyroid carcinoma. The metastatic course of thyroid carcinoma is an intricate process involving invasion, angiogenesis, cell trafficking, extravasation, organ specific homing, and growth. A key aspect in this process involves a multitude of interactions between chemokines and their receptors. Chemokines are a group of small proteins, which act to elicit normal physiologic and immune responses principally through recruitment of specific cell populations to the site of infection or malignancy. Thyroid cancer cells, like other tumors, possess the ability to corrupt the chemokine system to their advantage by altering cell movement into the tumor microenvironment and affecting all aspects of thyroid cancer progression.

Expression of CXCL12 and its receptor CXCR4 in patients with adenomyosis

The aim of the present study was to investigate the role of chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor, chemokine (C-X-C motif) receptor 4 (CXCR4) in the pathogenesis of adenomyosis (AD). Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction analysis were used to measure the protein and mRNA expression of CXCL12 and CXCR4 in eutopic endometrial and ectopic foci tissue samples. Samples from a total of 36 patients with AD (study group) were compared with endometrial tissue samples from 33 patients who underwent uterine fibroids surgery (control group) during the same period. All data are presented as the mean ± standard deviation and were analyzed with SPSS software (version 16.0). Analysis of variance was used for between group analysis and pairwise comparison was performed using Fisher's least significant difference post hoc test. The results of the present study revealed that CXCL12 and CXCR4 protein expression was significantly increased in ectopic foci tissue compared with eutopic endometrial tissue samples from patients with AD. CXCL12 and CXCR4 protein expression in ectopic foci and eutopic endometrial tissue samples were significantly increased compared with the control group (P<0.05 for between group comparisons). No significant differences were identified in CXCL12 and CXCR4 protein expression between the proliferative and secretory phases within each group. Furthermore, CXCL12 and CXCR4 mRNA expression was significantly increased in ectopic foci tissue and eutopic endometrial tissue compared with the control group (P<0.05 for between group comparisons). CXCL12 mRNA expression was markedly increased in ectopic foci tissue compared with eutopic endometrial tissue of patients with AD. The expression of CXCR4 mRNA was significantly increased in eutopic endometrial tissue compared with ectopic foci tissue and the control group (P<0.05 for between group comparisons). No significant differences were identified in CXCL12 and CXCR4 mRNA expression between proliferative and secretory phase within each group. In conclusion, CXCL12 and CXCR4 may induce the ectopia, and promote the spread and localized growth of endometrial cells in the development of AD.

Chemokine receptor patterns in lymphocytes mirror metastatic spreading in melanoma

Melanoma prognosis is dictated by tumor-infiltrating lymphocytes, the migratory and functional behavior of which is guided by chemokine or cytokine gradients. Here, we retrospectively analyzed the expression patterns of 9 homing receptors (CCR/CXCR) in naive and memory CD4+ and CD8+ T lymphocytes in 57 patients with metastatic melanoma (MMel) with various sites of metastases to evaluate whether T cell CCR/CXCR expression correlates with intratumoral accumulation, metastatic progression, and/or overall survival (OS). Homing receptor expression on lymphocytes strongly correlated with MMel dissemination. Loss of CCR6 or CXCR3, but not cutaneous lymphocyte antigen (CLA), on circulating T cell subsets was associated with skin or lymph node metastases, loss of CXCR4, CXCR5, and CCR9 corresponded with lung involvement, and a rise in CCR10 or CD103 was associated with widespread dissemination. High frequencies of CD8+CCR9+ naive T cells correlated with prolonged OS, while neutralizing the CCR9/CCL25 axis in mice stimulated tumor progression. The expansion of CLA-expressing effector memory CD8+ T cells in response to a single administration of CTLA4 blockade predicted disease control at 3 months in 47 patients with MMel. Thus, specific CCR/CXCR expression patterns on circulating T lymphocytes may guide potential diagnostic and therapeutic approaches.

Role of gene expression profiling in defining indeterminate thyroid nodules in addition to BRAF analysis

Fine-needle aspiration (FNA) is routinely used in the preoperative evaluation of thyroid nodules. However, 15% to 30% of aspirations yield indeterminate cytologic findings. Because the assessment of BRAF mutations seems to improve the diagnostic accuracy, this study evaluated BRAF mutations with Sanger sequencing and real-time methods in 650 consecutive thyroid aspirates. In addition, the expression of a large number of genes involved in basement membrane remodeling, extracellular matrix proteolysis, and cell adhesion was studied in both benign and malignant nodules to identify new diagnostic tools. In this prospective series, despite the use of a very sensitive BRAF mutational testing method, the frequency of a BRAF alteration being identified in indeterminate FNA samples was 3 of 68. Expression analysis revealed several genes that were differentially expressed between benign and malignant nodules (transforming growth factor, cadherin 1, collagen α1, catenin α1, integrin α3, and fibronectin 1 [FN1]), between follicular adenomas and follicular variant of papillary thyroid carcinoma (FN1, laminin γ1, integrin β2, connective tissue growth factor, catenin δ1, and integrin αV), and between BRAF-wild-type and BRAF-mutated papillary thyroid carcinomas (TIMP metallopeptidase inhibitor 1; catenin α1; secreted phosphoprotein 1; FN1; ADAM metallopeptidase with thrombospondin type 1 motif, 1; and selectin L). These data were partially confirmed with real-time polymerase chain reaction analysis and immunohistochemistry. When the cost/benefit ratio of the procedures was taken into account, BRAF mutational testing failed to increase diagnostic accuracy in cytologically indeterminate nodules. However, the additional analysis of the expression of specific molecular markers could have possible utility as a diagnostic tool, although further evidence based on a large series of samples is needed before definitive conclusions can be drawn. Cancer Cytopathol 2016;124:340-9. © 2015 American Cancer Society.

Positron emission tomographic imaging of CXCR4 in cancer: challenges and promises

Molecular imaging is an attractive platform for noninvasive detection and assessment of cancer. In recent years, the targeted imaging of the C-X-C chemokine receptor 4 (CXCR4), a chemokine receptor that has been associated with tumor metastasis, has become an area of intensive research. This review article focuses on positron emission tomography (PET) and aims to provide useful and critical insights into the application of PET to characterize CXCR4 expression, including the chemical, radiosynthetic, and biological requirements for PET radiotracers. This discussion is informed by a summary of the different approaches taken so far and a comparison of their clinical translation. Finally, our expert opinions as to potential future advances in the field are expressed.

Digital gene expression profiling of a series of cytologically indeterminate thyroid nodules

BACKGROUND

Fine-needle aspiration cytology (FNAC) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules. Testing for the expression of specific genes should improve the accuracy of FNAC diagnosis, especially when it is performed in samples with indeterminate cytology.

METHODS

In total, 69 consecutive FNACs that had both cytologic and histologic diagnoses were collected, and expression levels of 34 genes were determined in RNA extracted from FNAC cells by using a custom digital mRNA counting assay. A supervised k-nearest neighbor (K-nn) learning approach was used to build a 2-class prediction model based on a subset of 27 benign and 26 malignant FNAC samples. Then, the K-nn models were used to classify the 16 indeterminate FNAC samples.

RESULTS

Malignant and benign thyroid nodules had different gene expression profiles. The K-nn approach was able to correctly classify 10 FNAC samples as benign, whereas only 1 sample was grouped in the malignant class. Two malignant FNAC samples were incorrectly classified as benign, and 3 of 16 samples were unclassified.

CONCLUSIONS

Although the current data will require further confirmation in a larger number of cases, the preliminary results indicate that testing for specific gene expression appears to be useful for distinguishing between benign and malignant lesions. The results from this study indicate that, in indeterminate FNAC samples, testing for cancer-specific gene expression signatures, together with mutational analyses, could improve diagnostic accuracy for patients with thyroid nodules.

Effects of Astragaloside IV on the SDF-1/CXCR4 Expression in Atherosclerosis of apoE(-/-) Mice Induced by Hyperlipaemia

Astragaloside IV (AsIV) is the major effective component extracted from the Chinese herb Astragalus membranaceus, which has been widely used to treat cardiovascular disease. Recent studies have shown that AsIV can potentially protect the arteries from atherosclerosis; however the mechanisms underneath are unknown. The aim of this study was to investigate the effects of AsIV on blood lipids, CD40-CD40L signal system, and SDF-1/CXCR4 biological axis in high-fat diet apoE^−/− mice and reveal the molecular mechanisms of AsIV against atherosclerosis. Here, we showed that AsIV alleviated the extent of atherosclerosis in aorta of apoE^−/− mice. And AsIV can significantly downregulate PAC-1, CD40L, and CXCR4 expression on platelet surface in blood of high-fat diet apoE^−/− mice. AsIV also can significantly downregulate mRNA and protein level of SDF-1 and CXCR4 in thoracic aorta. Consistent with aorta CXCR4 expression, CXCR4 in bone marrow-derived endothelial progenitor cell (EPC) was also reduced. Meanwhile biochemical analysis showed that AsIV could downregulate TG, TC, and LDL-C levels and upregulate HDL-C level in blood of high-fat diet apoE^−/− mice. We concluded that the protective effects of AsIV in atherosclerosis injury may be related to regulating blood lipids, CD40-CD40L system, and SDF-1/CXCR4 biological axis. SDF-1/CXCR4 biological axis is probably one of the main targets of intervening atherosclerosis.

E-selectin expression and BRAF status in papillary thyroid carcinomas: Correlation with clinicopathologic features

BACKGROUND

Cell adhesion molecules, represented by the immunoglobulin family and selectins, play an important role in the progression of cancer. A correlation between selectins and tumor aggressiveness has been demonstrated in several reports.

METHODS

Eighty-eight patients (mean age, 41.0 ± 14 years) with papillary thyroid carcinoma (conventional variant and sized approximately 20 mm) were divided in 2 groups: 41 with encapsulated tumors and 47 with tumors with extrathyroidal extension. E-selectin expression was evaluated by immunohistochemical staining and semiquantitative real-time reverse-transcription polymerase chain reaction and normalized by calculating the z-score (positive: value above the population mean; negative: below the mean).

RESULTS

Lymph node metastasis (LNM) was found in 2 of 41 encapsulated tumors (4.8%) and in 19 of 47 tumors (40.4%) with extrathyroidal extension. BRAF mutation was present in 21 encapsulated tumors (51.2%) and in 31 tumors with extrathyroidal extension (65.9%). The mean E-selectin z-score was -0.32 for encapsulated tumors and 0.28 for tumors with extrathyroidal extension. E-selectin expression correlates with neoplastic infiltration (P = .04), the American Joint Commission on Cancer stage (P = .02), and BRAF mutation (P = .03).

CONCLUSION

E-selectin overexpression in association with BRAF mutation status could promote a more aggressive phenotype in papillary thyroid carcinoma.

Protein expression of the chemokine receptor CXCR4 and its ligand CXCL12 in primary cutaneous melanoma--biomarkers of potential utility?

Dysregulation of the CXCR4/CXCL12 axis, relevant in melanoma progression, activates cell cycle progression and migration via stimulation of the MAPK pathway. We sought to ascertain the cooperativity of the CXCR4/CXCL12 axis with established prognosticators and BRAF status in melanoma. Samples (n = 107) of primary cutaneous melanoma were assessed for protein expression of CXCR4 and CXCL12, and molecular analyses were performed to ascertain BRAF status. Univariate analyses of CXCR4 protein showed that the proportion of CXCR4 positives was greater in melanomas with absence of mitoses (P < .0001), absence of ulceration (P = .0008), and absence of regression (P = .02). Patients presenting at shallower stages (American Joint Committee on Cancer [AJCC] 1-2) exhibited a larger proportion of CXCR4 positives (76.9%, P < .0001 and 69.0%, P = .008), whereas those at deeper stages (AJCC 3-4) exhibited a larger proportion of negatives (75.0%, P = .004 and 66.7%, P = .22). In a multivariate analysis, lower odds of CXCR4 protein expression were associated with AJCC stage 3 (odds ratio [OR]=0.16, P = .01), AJCC stage 4 (OR=0.17, P = .04), and mitoses (OR=0.21, P = .01). Univariate analyses of CXCL12 protein showed that the proportion of CXCL12 negatives was significantly smaller in melanomas with depth of at least 1 mm, absence of ulceration, and absence of vascular invasion (P < .0001 for all). CXCR4 and CXCL12 appear to be biomarkers associated with established prognosticators of good and poor clinical outcome, respectively, in primary cutaneous melanoma. A BRAF mutation does not appear to be associated with CXCR4/CXCL12 axis upregulation in primary cutaneous melanoma.

Molecular pathways associated with aggressiveness of papillary thyroid cancer

The most common thyroid malignancy is papillary thyroid cancer (PTC). Mortality rates from PTC mainly depend on its aggressiveness. Geno- and phenotyping of aggressive PTC has advanced our understanding of treatment failures and of potential future therapies. Unraveling molecular signaling pathways of PTC including its aggressive forms will hopefully pave the road to reduce mortality but also morbidity from this cancer. The mitogen-activated protein kinase and the phosphatidylinositol 3-kinase signaling pathway as well as the family of RAS oncogenes and BRAF as a member of the RAF protein family and the aberrant expression of microRNAs miR-221, miR-222, and miR-146b all play major roles in tumor initiation and progression of aggressive PTC. Small molecule tyrosine kinase inhibitors targeting BRAF-mediated events, vascular endothelial growth factor receptors, RET/PTC rearrangements, and other molecular targets, show promising results to improve treatment of radioiodine resistant, recurrent, and aggressive PTC.

RNA sequencing identifies multiple fusion transcripts, differentially expressed genes, and reduced expression of immune function genes in BRAF (V600E) mutant vs BRAF wild-type papillary thyroid carcinoma

CONTEXT

The BRAF V600E mutation (BRAF-MUT) confers an aggressive phenotype in papillary thyroid carcinoma, but unidentified additional genomic abnormalities may be required for full phenotypic expression.

OBJECTIVE

RNA sequencing (RNA-Seq) was performed to identify genes differentially expressed between BRAF-MUT and BRAF wild-type (BRAF-WT) tumors and to correlate changes to patient clinical status.

DESIGN

BRAF-MUT and BRAF-WT tumors were identified in patients with T1N0 and T2-3N1 tumors evaluated in a referral medical center. Gene expression levels were determined (RNA-Seq) and fusion transcripts were detected. Multiplexed capture/detection and digital counting of mRNA transcripts (nCounter, NanoString Technologies) validated RNA-Seq data for immune system-related genes.

PATIENTS

BRAF-MUT patients included nine women, three men; nine were TNM stage I and three were stage III. Three (25%) had tumor infiltrating lymphocytes. BRAF-WT included five women, three men; all were stage I, and five (62.5%) had tumor infiltrating lymphocytes.

RESULTS

RNA-Seq identified 560 of 13 085 genes differentially expressed between BRAF-MUT and BRAF-WT tumors. Approximately 10% of these genes were related to MetaCore immune function pathways; 51 were underexpressed in BRAF-MUT tumors, whereas 4 (HLAG, CXCL14, TIMP1, IL1RAP) were overexpressed. The four most differentially overexpressed immune genes in BRAF-WT tumors (IL1B; CCL19; CCL21; CXCR4) correlated with lymphocyte infiltration. nCounter confirmed the RNA-Seq expression level data. Eleven different high-confidence fusion transcripts were detected (four interchromosomal; seven intrachromosomal) in 13 of 20 tumors. All in-frame fusions were validated by RT-PCR.

CONCLUSION

BRAF-MUT papillary thyroid cancers have reduced expression of immune/inflammatory response genes compared with BRAF-WT tumors and correlate with lymphocyte infiltration. In contrast, HLA-G and CXCL14 are overexpressed in BRAF-MUT tumors. Sixty-five percent of tumors had between one and three fusion transcripts. Functional studies will be required to determine the potential role of these newly identified genomic abnormalities in contributing to the aggressiveness of BRAF-MUT and BRAF-WT tumors.

FoxP3 expression in papillary thyroid carcinoma: a possible resistance biomarker to iodine 131 treatment

BACKGROUND

The forkhead transcription factor FoxP3 plays an important role in regulatory T cell (Treg) functions. Tregs are critical in maintaining immunologic tolerance. It has been shown that vaccination against FoxP3-expressing cells is associated with enhancement of tumor immunity. Tregs appear to be increased in blood and in the tumor microenvironment of patients with different cancer types. Tumor cells themselves can express FoxP3. The present study investigates the possible role of FoxP3 expression in a series of human papillary thyroid cancers with a mean follow-up time of 15 years.

METHODS

One hundred five cases of papillary thyroid carcinoma (PTC) were investigated, and FoxP3 expression was evaluated in both tumor cells and tumor-associated infiltrates. For all patients, clinical/pathologic features were considered and the results analyzed by statistical tests.

RESULTS

Of the 105 PTC cases, 45 (43%) scored FoxP3-positive and 60 (57%) were negative. FoxP3 staining was localized predominantly in the cytoplasm of tumor cells. In some cases, both nuclear and cytoplasmic staining was seen in infiltrating cells. FoxP3 expression in tumor cells was correlated with the presence of extrathyroid invasion (p=0.04) and distant metastasis (p=0.04), but not with overall survival. Interestingly, FoxP3 expression in neoplastic cells was significantly associated with a resistance phenotype to radioiodine treatment (p=0.041).

CONCLUSIONS

The data show an association of FoxP3 expression with features of PTC that seem to have a specific impact on radioiodine sensitivity.

Effect of CXCL12/CXCR4 on increasing the metastatic potential of non-small cell lung cancer in vitro is inhibited through the downregulation of CXCR4 chemokine receptor expression

Lung cancer ranks as the most common type of cancer in males worldwide. Although great advances have been achieved in chemotherapy and radiotherapy, the long-term survival rate of lung cancer patients has not improved significantly. Dissemination of lung cancer in the thoracic cavity and metastatic spread to the liver, bone and brain are characteristic of non-small cell lung cancer (NSCLC), constituting the primary source of morbidity and mortality in lung cancer. Increasing evidence also indicates that the CXC chemokine receptor 4 (CXCR4)/chemokine CXC motif ligand 12 (CXCL12) chemokine axis is important for the cell invasion and migration of lung cancer. CXCR4 is a G protein-coupled receptor with a major role in lymphocyte homing. Its ligand, CXCL12, is secreted by target organs and functions as a highly efficient chemotactic factor for T cells, monocytes, pre-B cells, dendritic cells and myeloid bone marrow-derived cells. In the current study, recombinant CXCR4-specific small interfering RNA-pBSilence1.1 plasmids were constructed and transfected into the A549 NSCLC cell line in vitro. Reverse transcription polymerase chain reaction and western blotting revealed that CXCR4 was downregulated in transfected cells compared with control cells. The results of MTT and Transwell migration assays indicated that the specific downregulation of CXCR4 inhibited cell growth, invasiveness and migration. Thus, siRNA targeting of CXCR4 may effectively inhibit the effect of CXCL12/CXCR4 on increasing the metastatic potential of NSCLC.

Effect of short hairpin RNA-induced CXCR4 silence on ovarian cancer cell

This study was aimed to investigate the effect of down-regulating the CXC chemokine receptor-4 (CXCR4) expression on cell proliferation, invasion and migration of human ovarian cancer cell line SW626. The CXCR4 specific short hairpin RNA (shRNA) plasmid vector was constructed and then transfected into the SW626 cells. The expression of CXCR4 mRNA and protein was detected by real-time RT-PCR and western blot respectively. Cell proliferation was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell invasion and migration was assayed in Biocoat Matrigel invasion chambers. The expression level of CXCR4 in SW626 cell transfected with CXCR4-siRNA was inhibited, leading to significant decrease in SW626 cell proliferation, invasion and migration. We conclude that CXCR4 is essential for tumor cell proliferation and invasion. The CXCR4 molecule is a potential therapeutic target to control ovarian cancer cell growth or metastasis.

Mouse models of follicular and papillary thyroid cancer progression

A significant number of well-differentiated thyroid cancers progress or recur, becoming resistant to current therapeutic options. Mouse models recapitulating the genetic and histological features of advanced thyroid cancer have been an invaluable tool to dissect the mechanisms involved in the progression from indolent, well differentiated tumors to aggressive, poorly differentiated carcinomas, and to identify novel therapeutic targets. In this review, we focus on the lessons learned from models of epithelial cell-derived thyroid cancer showing progression from hyperplastic lesions to locally invasive and metastatic carcinomas.