Altered chemokine receptor expression in papillary 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.

C-C Chemokine Receptor 7 in Cancer

C-C chemokine receptor 7 (CCR7) was one of the first two chemokine receptors that were found to be upregulated in breast cancers. Chemokine receptors promote chemotaxis of cells and tissue organization. Since under homeostatic conditions, CCR7 promotes migration of immune cells to lymph nodes, questions immediately arose regarding the ability of CCR7 to direct migration of cancer cells to lymph nodes. The literature since 2000 was examined to determine to what extent the expression of CCR7 in malignant tumors promoted migration to the lymph nodes. The data indicated that in different cancers, CCR7 plays distinct roles in directing cells to lymph nodes, the skin or to the central nervous system. In certain tumors, it may even serve a protective role. Future studies should focus on defining mechanisms that differentially regulate the unfavorable or beneficial role that CCR7 plays in cancer pathophysiology, to be able to improve outcomes in patients who harbor CCR7-positive cancers.

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.

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.

The CXCL12-CXCR4 axis promotes migration, invasiveness, and EMT in human papillary thyroid carcinoma B-CPAP cells via NF-κB signaling

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy involving local and distant metastasis. It is known that CXC chemokine ligand 12 (CXCL12) interacts specifically with CXC chemokine receptor 4 (CXCR4) to guide the migration of PTC cells. However, the signaling pathway downstream of the CXCL12-CXCR4 axis in PTC is not fully understood. In the present study, high expression of CXCR4 was detected in 38 out of 82 specimens of PTC, and the expression level of CXCR4 significantly correlated with the stage of PTC. Additionally, the roles of the CXCL12-CXCR4 axis in the migration, invasion, and epithelial-mesenchymal transition (EMT) of B-CPAP cells were investigated in vitro. The motility and invasiveness were significantly enhanced in CXCR4-overexpressing B-CPAP cells with CXCL12 treatment. Moreover, the CXCL12-CXCR4 axis promoted the EMT process, as evidenced by a decreased level of E-cadherin and increased expressions of N-cadherin and vimentin. Furthermore, the CXCL12-CXCR4 axis activated the nuclear factor kappa-B (NF-κB) signaling pathway, whereas BAY11-7082, an IκB phosphorylation inhibitor, counteracted CXCL12-CXCR4-induced migration, invasion, and EMT processes in B-CPAP cells. In conclusion, the CXCL12-CXCR4 axis promotes the migration, invasion, and EMT processes in B-CPAP cells, at least partly, by activating the NF-κB signaling pathway.

Current and future immunotherapies for thyroid cancer

INTRODUCTION

Cancer immunotherapies were approved in recent years, including immune checkpoint inhibitors. Experience with ipilimumab (CTLA-4 antagonist), nivolumab and pembrolizumab (PD-1 antagonists), and atezolizumab (PD-L1 antagonist) has shown that the impact on overall survival in cancer patients is paramount. Immune checkpoint inhibitors target the immune system and they can be applied across multiple cancers; the response rate is ranging from 20 to 40%. Many studies have shown that thyroid cancer (TC) cells produce cytokines and chemokines, inducing several tumor-promoting effects. Targeting and/or lowering cytokines and chemokines concentrations within the tumor microenvironment would produce a therapeutic benefit. In TC, increased Treg and PD-1⁺ T cell frequencies are indicative of aggressive disease and PD-L1 expression correlates with a greater risk of recurrence. Area covered: After performing a literature search, a few pioneering studies have evaluated immunotherapy in thyroid cancer. More recently a case has been described involving anaplastic thyroid cancer treated with vemurafenib and nivolumab, with substantial regression and complete radiographic and clinical remission. Expert commentary: The use of immune checkpoint inhibitors in aggressive TC has not yet been extensively investigated and further studies in a large number of TC patients are urgently needed.

Emerging roles of the CXCL12/CXCR4 axis in pancreatic cancer progression and therapy

Chemokine networks regulate a variety of cellular, physiological, and immune processes. These normal functions can become appropriated by cancer cells to facilitate a more hospitable niche for aberrant cells by enhancing growth, proliferation, and metastasis. This is especially true in pancreatic cancer, where chemokine signaling is a vital component in the development of the supportive tumor microenvironment and the signaling between the cancer cells and surrounding stromal cells. Although expression patterns vary among cancer types, the chemokine receptor CXCR4 has been implicated in nearly every major malignancy and plays a prominent role in pancreatic cancer development and progression. This receptor, in conjunction with its primary chemokine ligand CXCL12, promotes pancreatic cancer development, invasion, and metastasis through the management of the tumor microenvironment via complex crosstalk with other pathways. Thus, CXCR4 likely contributes to the poor prognoses observed in patients afflicted with this malignancy. Recent exploration of combination therapies with CXCR4 antagonists have demonstrated improved outcomes, and abolishing the contribution of this pathway may prove crucial to effectively treat pancreatic cancer at both the primary tumor and metastases.

Cell surface nucleolin interacts with CXCR4 receptor via the 212 c-terminal portion

Previously, we reported that CXCR4 receptor interacted with cell surface nucleolin, and the synergy of CXCR4 and nucleolin plays an essential role in malignant transformation. Here, we continued to conduct a structure-function analysis of nucleolin to identify which portion can efficaciously bind to CXCR4. In the present study, the expression of CXCR4 and nucleolin in 100 cases of papillary thyroid cancer (PTC) samples was investigated through immunohistochemistry (IHC). Subsequently, using nucleolin mutants and pull-down assay, we investigated precise interactions between CXCR4 and nucleolin in HEK-293 cells. A previous study demonstrated CXCR4 and nucleolin co-expressed in cell lines, and the present study further identified that CXCR4 and nucleolin co-expressed in PTC tissues, instead of normal tissues. The nucleolin mutant analysis revealed that nucleolin can efficaciously bind CXCR4 to activate CXCR4 signaling by 212 C-terminal domain. Conversely, N-terminal, RBD and GAR mutants of nucleolin showed no sign of activation of CXCR4 signaling, and differences were statistically insignificant (p > 0.05). In conclusion, these results suggested nucleolin is essential to activate CXCR4 signaling via 212 C-terminal domain, which is required for cell growth, migration, and invasiveness. Furthermore, nucleolin may interact with more G protein-coupled receptors, at least chemokine receptor. Our study will lay a new foundation for cancer therapy by antagonizing nucleolin and CXCR4.

Cell surface nucleolin is crucial in the activation of the CXCL12/CXCR4 signaling pathway

Recently, CXCL12-CXCR4 has been focused on therapeutic strategies for papillary thyroid carcinoma (PTC) and other cancers. At the same time, cell surface nucleolin is also over-expressed in PTC and others. Interestingly, a few reports suggest that either CXCR4 or cell surface nucleolin is a co-receptor for HIV-1 entry into CD4+ T cells, which indicates that there is a relationship between CXCR4 and nucleolin. In this study, antibody and siRNA were used to identify effects of cell surface nucleolin and CXCR4 on cell signaling; soft-agar colony formation assay and Transwell assay were used to determine roles of nucleolin and CXCR4 in cell proliferation and migration. Importantly, co-immunoprecipitation was used to demonstrate the relationship between CXCR4 and nucleolin. Results showed CXCR4 and nucleolin were co-expressed in PTC cell line K1, B-CPAP, and TPC-1. Either cell surface nucleolin or CXCR4 was necessary to prompt extracellular signal-regulated kinase phosphorylation. When blocked, CXCR4 or nucleolin can significantly affect TPC-1 proliferation and migration (p < 0.01). Co-immunoprecipitation analysis identified that nucleolin can bind and interact with CXCR4 to activate CXCR4 signaling. This study suggests that nucleolin is crucial in the activation of CXCR4 signaling, which affects cell growth, migration, and invasiveness. Further, nucleolin may interact with other receptors. Our study also offers new ideas for cancer therapy.

Different CXCR4 expression according to various histologic subtype of papillary thyroid carcinoma

Functional chemokine (C-X-C motif) receptor 4 (CXCR4) is well known to be over-expressed in papillary thyroid carcinoma (PTC). The aim of this study was to evaluate whether or not the expression of CXCR4 is different by histological subtypes of PTC and to elucidate the relationship between the expression of CXCR4 and clinicopathologic factors. CXCR4 expression in 127 PTC samples was assessed using immunohistochemical staining. The expression of CXCR4 showed different patterns according to the histological subtype of PTC (p < 0.001). A strong expression of CXCR4 was observed more frequently in the poorly differentiated region of PTC (81.0 %) than in classical PTC (50.0 %). Strong CXCR4 expression was less frequently shown in follicular variant (33.9 %) and in diffuse sclerosing variant (14.3 %) of PTC. CXCR4 expression showed a distinct pattern according to the histological subtype of PTC although not associated with other clinicopathological parameters.

Modulation of tumor immunity by soluble and membrane-bound molecules at the immunological synapse

To circumvent pathology caused by infectious microbes and tumor growth, the host immune system must constantly clear harmful microorganisms and potentially malignant transformed cells. This task is accomplished in part by T-cells, which can directly kill infected or tumorigenic cells. A crucial event determining the recognition and elimination of detrimental cells is antigen recognition by the T cell receptor (TCR) expressed on the surface of T cells. Upon binding of the TCR to cognate peptide-MHC complexes presented on the surface of antigen presenting cells (APCs), a specialized supramolecular structure known as the immunological synapse (IS) assembles at the T cell-APC interface. Such a structure involves massive redistribution of membrane proteins, including TCR/pMHC complexes, modulatory receptor pairs, and adhesion molecules. Furthermore, assembly of the immunological synapse leads to intracellular events that modulate and define the magnitude and characteristics of the T cell response. Here, we discuss recent literature on the regulation and assembly of IS and the mechanisms evolved by tumors to modulate its function to escape T cell cytotoxicity, as well as novel strategies targeting the IS for therapy.

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

Emerging evidence indicates that interactions between chemokine receptors and their ligands may have a critical role in several steps of tumor development, including tumor growth, progression, and metastasis. In this report, we retrospectively evaluated CXCR4 expression in a consecutive series of 200 papillary thyroid carcinomas. We investigated the relationship between the clinicopathological features of the tumors and mutations in the BRAF gene to verify whether overexpression of CXCR4 is linked to more aggressive behavior in thyroid tumors. CXCR4 protein expression was evaluated by immunohistochemical staining. A final staining score was calculated by adding the score representing the percentage of positive cells to the intensity score. The CXCR4 expression of each papillary thyroid carcinoma sample was normalized by calculating the z score for each final staining score. Univariate analysis was used to correlate CXCR4 expression with the papillary thyroid carcinoma variant, the degree of neoplastic infiltration, the American Joint Commission on Cancer stage, the presence of lymphocytic thyroiditis and the mutation status of the BRAF gene. Multiple regression analysis confirmed a strong association between CXCR4, BRAF mutation and the degree of neoplastic infiltration. These data clearly indicate that the chemokine receptor expression induced by oncogenic activation could be the major determinant of the local aggressiveness of neoplastic cells. In conclusion, our data indicate that CXCR4 expression and BRAF mutation status could cooperatively induce and promote a more aggressive phenotype in papillary thyroid carcinoma through several pathways and specifically increase the tumors' spread outside of the thyroid gland.

Characterization of CXCR4 expression in chondrosarcoma of bone

CONTEXT

Alterations in molecular elements derived from the CXC chemokine receptor 4 (CXCR4)/stromal-derived factor 1 (SDF-1) cytokine system have been found to strongly correlate with neoplastic progression leading to metastasis in a number of tumors, including osteosarcoma. Excluding hematologic malignancies, chondrosarcoma of bone is the most common primary malignant tumor of bone in adults in the United States. Like osteosarcoma, chondrosarcoma preferentially metastasizes to lung, bone, and very rarely to regional lymph nodes. However, the role of the signal pathway(s) driving neoplastic progression in chondrosarcoma has not yet been clearly elucidated.

OBJECTIVE

To test whether CXCR4 was detectable in chondrosarcoma and whether CXCR4 expression levels correlated with chondrosarcoma grade.

DESIGN

Twenty-two chondrosarcoma samples banked at our institution between 2001 and 2006 were retrieved for study. By using invasive ductal carcinoma of the breast and osteosarcoma as the positive controls, immunohistochemistry was performed on paraffin-embedded tissue sections and the intensity of the tumor cells was analyzed by morphometric techniques.

RESULTS

All chondrosarcoma cases (22 of 22) were immunoreactive for CXCR4. However, the staining intensity of the CXCR4 between the low- and high-grade groups was significantly different. There was a higher staining intensity in high-grade chondrosarcoma cells (P < .001).

CONCLUSION

CXCR4 is expressed in chondrosarcomas. CXCR4 expression levels were higher in high-grade chondrosarcoma cells than in low-grade specimens. A larger number of cases will be required to confirm these results and expand the observation, but preliminary data would argue for CXCR4 immunohistochemistry as a potential marker for biologic aggressiveness in chondrosarcoma of bone.

Thyroid cancer and lymph node metastases

There is considerable controversy about the prognostic implications of lymph node metastases in patients with papillary thyroid cancer and whether patients with papillary thyroid cancer should have a prophylactic or selective central (level VI) neck dissection. Some experts report that a prophylactic ipsilateral neck dissection results in fewer patients having elevated thyroglobulin levels but others do not agree. A comprehensive review of the literature suggests that the presence of macroscopic metastases of papillary thyroid cancer in cervical lymph nodes results in a higher recurrence rate and increased death rate, especially in patients 45 years of age or older, whereas microscopic nodal metastases do not appear to adversely influence survival. Until more information is available we recommend preoperative ultrasonography and a selective ipsilateral neck dissection for patients with papillary thyroid cancer.

Targeting CCL11 in the treatment of ovarian cancer

IMPORTANCE OF THE FIELD

The chemokine network, comprised of mediators of inflammation, has been implicated in the development of a number of human cancers. The eosinophil chemoattractant CCL11 was recently shown to play a role in the development of ovarian cancer. Here we review findings regarding CCL11 and discuss its use as a target in the treatment of ovarian cancer.

AREAS COVERED IN THIS REVIEW

We review published findings related to the physiological actions of CCL11, its tumourigenic effects, the chemokine network and inflammatory response present in ovarian cancer, and the current state of therapeutics targeting CCL11 and its receptors. Findings published within the last 10 years receive particular attention.

WHAT THE READER WILL GAIN

An overview of the emerging role of the chemokine network in malignancy and a review of the role of CCL11 in ovarian tumourigenesis. The reader will be presented with a description of the unique aspects of CCL11 action and the inflammatory environment in the setting of ovarian malignancy that make this chemokine an attractive target for intervention.

TAKE HOME MESSAGE

Targeting CCL11 and its receptors through the use of monoclonal antibodies and small-molecule inhibitors may represent a beneficial new avenue of ovarian cancer treatment.