Application of chemokine CXC motif ligand 12 as a novel diagnostic marker in preoperative fine-needle aspiration biopsy for papillary thyroid carcinoma

Diagnostic and prognostic utility of TROP-2, SLP-2, and CXCL12 expression in papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most frequent thyroid malignancy. Histopathological examination is widely accepted as the gold standard test for the diagnosis of PTC. However, the histopathological examination sometimes can't differentiate PTC from other thyroid diseases. Differentiating PTC from other thyroid diseases is essential for a therapeutic approach and prognosis.

OBJECTIVES

The current study was performed to investigate the utility of TROP-2, SPL-2, and CXCL12 mRNA and protein expression in discriminating PTC from other thyroid diseases that mimic PTC.

METHODS

The current study was performed on 75 cases of surgically resected thyroid glands. The cases were distributed in two groups: the PTC group and the non-PTC group. The PTC group consisted of 35 cases (25 patients of the classic PTC variant and 10 patients of the PTC follicular variant). The non-PTC group consisted of 40 cases (10 cases were multinodular goiter, 5 cases were Graves' disease, 5 cases were Hashimoto thyroiditis, 15 patients were follicular adenoma (FA) and 5 cases were follicular carcinoma). TROP-2, SPL-2, and CXCL12 mRNA expression were estimated by qRT-PCR, and protein expression was estimated by immunohistochemistry.

RESULTS

There were upregulated TROP-2, SPL-2, and CXCL12 mRNA and protein expressions in PTC compared to non-PTC (P< 0.001, for each). There was a statistically significant upregulation in the mRNA expression of the three genes among PTC cases with larger tumor sizes (P< 0.001, for each), those with tumor stages III and IV (P= 0.008, 0.002 and < 0.001 respectively), and those with LN metastasis (P< 0.001, for each). Moreover, there was a statistically significant upregulation in CXCL-12 gene expression among PTC cases with extra-thyroid extension (P< 0.001).

CONCLUSION

mRNA expression of TROP-2, SPL-2, and CXCL12 among PTC cases increased in larger tumor size, tumor stages III and IV, and LN metastasis. Moreover, there was an increase in CXCL-12 gene expression among PTC cases with extra-thyroid extension. Thus, TROP-2, SPL-2, and CXCL12 expressions could be possible diagnostic and prognostic markers in PTC.

Role of chemokines in breast cancer

Chemokines belong to a family of chemoattractant cytokines and are well known to have an essential role in various cancer aetiologies. Multiplesubsets of immune cells are recruited and enrolled into the tumor microenvironment through interactions between chemokines and their specific receptors. These populations and their interactions have a distinct impact on tumor growth, progression, and treatment outcomes. While it is clear that many chemokines and their cognate receptors can be detected in breast and other cancers, the role of each chemokine and receptor has yet to be determined. This review focuses on the main chemokines that play a crucial role in the tumor microenvironment, emphasizing breast cancer. We have also discussed the techniques used to identify the chemokines and their future implication in the early diagnosis of cancer. In-depth knowledge of chemokines and their role in breast cancer progression can provide specific targets for breast cancer biotherapy.

Expression of CXCR4 and CXCR7 in papillary thyroid carcinoma and adjacent tissues and their relationship with pathologic indicators of tumor aggressiveness

The receptors of chemokines play a significance role in the aggressiveness of tumor. CXCR4/CXCR7 promote metastasis of papillary thyroid carcinoma (PTC). This study examined the expresssion of chemokine receptors CXCR4/CXCR7 in human tissue specimens of PTC and peritumoral nonmalignant tissues. The correlation between CXCR4/CXCR7 and the clinicopathological factors in PTC was also determined. CXCR4/CXCR7 were examined in 115 PTC tissues from 115 patients using immunohistochemistry. Staining intensity was compared with patients and tumor characteristics including gender, age, tumor size, capsule invasion, multifocality, lymph node metastasis, and nature of paracancerous tissue. [Statistics: rank sum test, Spearman rank order correlation test; p < 0.05]. Higher expression rates of CXCR4/CXCR7 exhibited in PTC compared with peritumoral nonmalignant tissues. The expression of them was correlated in cancer and paracancerous specimens. A trend toward higher CXCR4/CXCR7 expression was found among tumors showing positive lymph nodes and capsule invasion, while no association with sex, age, tumor size, and nature of paracancerous tissue. Number of lymph nodes was associated with higher intensity IHC staining for CXCR4/CXCR7. Intense staining for CXCR4 was also associated with multifocality. Expression of CXCR4/CXCR7 by PTCs was correlated with lymph node metastasis and capsule invasion. Although multiple bias, they were thought to play a significance role in the aggressiveness of PTC, which provides potential targets for therapeutic interventions.

The clinical usefulness of chemokine C-X-C Motif Ligand 12 as a diagnostic marker for Papillary Thyroid Carcinoma

Background

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer worldwide. It is essential to develop methods for the accurate diagnosis of PTC to avoid unnecessary surgery. The chemokine C-X-C motif ligand 12 (CXCL12) is associated with various cancers. We aimed to investigate the efficacy of CXCL12 in the diagnosis of PTC in fine-needle aspiration (FNA) specimens.

Methods

We prospectively collected samples from 58 patients who were scheduled for surgical treatment of PTC from 2013 to 2015. Tissue samples of 31 people with benign thyroid conditions were used as controls. Immunocytochemical and immunohistochemical staining for CXCL12 was performed on FNAs and corresponding tissue specimens. B-type Raf kinase (BRAF) V600E mutant protein expression and gene mutation were also analyzed to compare the clinical usefulness.

Results

: The mean age of the patients was 49.1 ± 1.4 years and 88.1% were women. Positive CXCL12 staining was observed in 6.5% of benign and in 98.3% of PTC samples; positive BRAF V600E mutant protein expression was found in 19.4% of benign and 93.1% of PTC samples. For the diagnosis of PTC for CXCL12 staining of FNA specimens, the calculated values were 93.1% sensitivity, 90.3% specificity, 94.7% positive predictive value, 87.5% negative predictive value, and 89.1% accuracy. CXCL12 had 100% sensitivity and specificity for the 12 cases of atypia of undetermined significance (AUS) diagnosed in FNA specimens.

Conclusions

CXCL12 may be a useful diagnostic tool for PTC, especially when the FNA specimen is classified as AUS.

Thyroid Cancer Stem-Like Cells: From Microenvironmental Niches to Therapeutic Strategies

Thyroid cancer (TC) is the most common endocrine malignancy. Recent progress in thyroid cancer biology revealed a certain degree of intratumoral heterogeneity, highlighting the coexistence of cellular subpopulations with distinct proliferative capacities and differentiation abilities. Among those subpopulations, cancer stem-like cells (CSCs) are hypothesized to drive TC heterogeneity, contributing to its metastatic potential and therapy resistance. CSCs principally exist in tumor areas with specific microenvironmental conditions, the so-called stem cell niches. In particular, in thyroid cancer, CSCs' survival is enhanced in the hypoxic niche, the immune niche, and some areas with specific extracellular matrix composition. In this review, we summarize the current knowledge about thyroid CSCs, the tumoral niches that allow their survival, and the implications for TC therapy.

MicroRNA-101 Targets CXCL12-Mediated Akt and Snail Signaling Pathways to Inhibit Cellular Proliferation and Invasion in Papillary Thyroid Carcinoma

Escalating evidence suggests that microRNA-101 (miR-101) is implicated in the development and progression of various cancers, including papillary thyroid carcinoma (PTC). However, the biological function and molecular mechanisms of miR-101 in PTC are still unclear. In this study, we demonstrated that miR-101 expression was significantly decreased in PTC tissues and cell lines. Clinically, a low level of miR-101 was positively associated with advanced histological stages and lymph node and distant metastases. The expression of CXCL12 was negatively correlated with miR-101 level in PTC. CXCL12 was validated as a direct target of miR-101 in PTC cells. Functional experiments proved that miR-101 markedly reduced the proliferation, apoptosis escape, migration, and invasion of PTC cells. Moreover, CXCL12 restoration rescued the suppressive effects of miR-101 on PTC cells by activating Akt- and EMT-associated signaling pathways. Overall, miR-101 exerts oncostatic effects on PTC by downregulating CXCL12 and repressing its downstream Akt and Snail signaling pathways, suggesting that miR-101/CXCL12/Akt or Snail axis may serve as a potential therapeutic target for PTC.

Role of Chemokines in Thyroid Cancer Microenvironment: Is CXCL8 the Main Player?

Tumor-related inflammation does influence the biological behavior of neoplastic cells and ultimately the patient's outcome. With specific regard to thyroid cancer, the issue of tumor-associated inflammation has been extensively studied and recently reviewed. However, the role of chemokines, which play a crucial role in determining the immuno-phenotype of tumor-related inflammation, was not addressed in previous reviews on the topic. Experimental evidence shows that thyroid cancer cells actively secrete a wide spectrum of chemokines and, at least for some of them, solid scientific data support a role for these immune-active molecules in the aggressive behavior of the tumor. Our proposal for a review article on chemokines and thyroid cancer stems from the notion that chemokines, besides having the ability to attract and maintain immune cells at the tumor site, also produce several pro-tumorigenic actions, which include proangiogenetic, cytoproliferative, and pro-metastatic effects. Studies taking into account the role of CCL15, C-X-C motif ligand 12, CXCL16, CXCL1, CCL20, and CCL2 in the context of thyroid cancer will be reviewed with particular emphasis on CXCL8. The reason for focusing on CXCL8 is that this chemokine is the most studied one in human malignancies, displaying multifaceted pro-tumorigenic effects. These include enhancement of tumor cells growth, metastatization, and angiogenesis overall contributing to the progression of several cancers including thyroid cancer. We aim at reviewing current knowledge on the (i) ability of both normal and tumor thyroid cells to secrete CXCL8; (ii) direct/indirect pro-tumorigenic effects of CXCL8 demonstrated by in vitro and in vivo studies specifically performed on thyroid cancer cells; and (iii) pharmacologic strategies proven to be effective for lowering CXCL8 secretion and/or its effects on thyroid cancer cells.

Thyroid Fine-Needle Aspiration Cytology Practice in Korea

We reviewed the current status of thyroid fine-needle aspiration cytology (FNAC) in Korea. Thyroid aspiration biopsy was first introduced in Korea in 1977. Currently, radiologists aspirate the thyroid nodule under the guidance of ultrasonography, and cytologic interpretation is only legally approved when a cytopathologist makes the diagnosis. In 2008, eight thyroid-related societies came together to form the Korean Thyroid Association. The Korean Society for Cytopathology and the endocrine pathology study group of the Korean Society for Pathologists have been updating the cytologic diagnostic guidelines. The Bethesda System for Reporting Thyroid Cytopathology was first introduced in 2009, and has been used by up to 94% of institutions by 2016. The average diagnosis rates are as follows for each category: I (12.4%), II (57.9%), III (10.4%), IV (2.9%), V (3.7%), and VI (12.7%). The malignancy rates in surgical cases are as follows for each category: I (28.7%), II (27.8%), III (50.6%), IV (52.3%), V (90.7%), and VI (100.0%). Liquid-based cytology has been used since 2010, and it was utilized by 68% of institutions in 2016. The categorization of thyroid lesions into "atypia of undetermined significance" or "follicular lesion of undetermined significance" is necessary to draw consensus in our society. Immunocytochemistry for galectin-3 and BRAF is used. Additionally, a molecular test for BRAF in thyroid FNACs is actively used. Core biopsies were performed in only 44% of institutions. Even the institutions that perform core biopsies only perform them for less than 3% of all FNACs. However, only 5% of institutions performed core biopsies up to three times more than FNAC.

Fine-Needle Aspiration with Immunohistochemistry Using a Modified Scrape Cell Block Technique for the Diagnosis of Thyroid and Parathyroid Nodules

OBJECTIVE

To evaluate the diagnostic accuracy of a modified scrape cell block (SCB) technique in a large series of patients. The technique was especially developed and tested for fine-needle aspiration of thyroid and parathyroid nodules.

STUDY DESIGN

Eighty-two ultrasound-guided fine-needle aspiration specimens with the sonographic aspect of a thyroid (n = 33) or a possible parathyroid nodule (n = 49) were studied. Immunohistochemistry (IHC) was used on cell blocks containing plasma, thromboplastin, and selected 3-dimensional cell aggregates scraped off Papanicolaou-stained smears. Antibodies for chromogranin A, thyroglobulin, parathyroid hormone, calcitonin, and carcinoembryonic antibody (CEA) were used. In cases of reduced immunosensitivity or suspected metastases or rare primary tumors, additional IHC markers were employed.

RESULTS

Chromogranin A was expressed in all 28 parathyroid adenomas (PA), in 7 of 8 hyperplastic parathyroid glands, and in 13 of 14 medullary thyroid carcinomas (MTC). When combining positivity for chromogranin A and calcitonin/CEA, the specificity for the detection of MTC was 100%. Parathyroid hormone was expressed in 26 of 36 parathyroid nodules (72.2%). When combining follicular microarchitecture and expression of chromogranin A, the specificity for the detection of parathyroid tissue was 97%.

CONCLUSION

With the modified SCB technique, accurate cytological diagnoses were obtained in 97.6% of 82 patients.

Expression and function of CXCL12/CXCR4/CXCR7 in thyroid cancer

The contribution of CXCL12/CXCR4/CXCR7 axis to cancer progression has been increasingly recognized. However, its role in thyroid cancer development remains unclear. The present study aimed to examine the expression and function of CXCL12 and its receptors in thyroid cancer. The expression of CXCL12/CXCR4/CXCR7 in human tissue specimens of papillary, follicular, medullary, and anaplastic thyroid carcinoma, follicular adenoma, Hashimoto's thyroiditis and nodular goiter were examined by immunohistochemistry using a tissue microarray. CXCR4 and CXCR7 were over-expressed in human thyroid cancer cells K1 by transduction of recombinant lentivirus. The effect of overexpression of CXCR4 and CXCR7 on K1 cell proliferation and invasion and the molecular mechanism underlying the effect were investigated. CXCL12 was exclusively expressed in papillary thyroid carcinoma tissue but absent in other types of thyroid malignancies and benign lesions. CXCR7 was widely expressed in the endothelial cells of all types of malignancy but only occasionally detected in benign lesions. CXCR4 was expressed in 62.5% of papillary thyroid carcinoma tissue specimens and in 30–40% of other types of malignancy, and it was either absent or weakly expressed in benign lesions. CXCL12 stimulated the invasion and migration of K1 cells overexpressing CXCR4, but did not affect K1 cells overexpressing CXCR7. K1 cell proliferation was not affected by overexpression of CXCR4 or CXCR7. Overexpression of CXCR4 in K1 cells significantly increased AKT and ERK phosphorylation and markedly induced the expression and activity of matrix metalloproteinase-2 (MMP-2). Thus, CXCL12 may be an effective diagnostic marker for papillary thyroid carcinoma, and CXCL12/CXCR4/CXCR7 axis may contribute to thyroid cancer development by regulating cancer cell migration and invasion via AKT and ERK signaling and MMP-2 activation.

MiR-137 acts as a tumor suppressor in papillary thyroid carcinoma by targeting CXCL12

Accumulating evidence has shown that aberrantly expressed microRNAs (miRs) are extensively involved in tumorigenesis. microRNA-137 (miR-137) has been reported as a tumor suppressor in various types of cancer. However, the biological function and underlying molecular mechanism of miR-137 in papillary thyroid carcinoma (PTC) remain largely unknown. Therefore, the present study aimed to investigate the expression pattern of miR-137 and its functional significance in PTC. Quantitative RT-PCR (qRT-PCR) assay showed that miR-137 expression was significantly downregulated in human PTC tissues, and its expression was significantly negatively correlated with tumor-node-metastasis (TNM) stage and lymph node metastasis. Functional assays showed that forced expression of miR-137 in PTC cells significantly inhibited proliferation, colony formation, migration and invasion in vitro. Importantly, on the basis of bioinformatic analysis and luciferase reporter assay, we found that miR-137 directly targeted the 3'-untranslated region (3'-UTR) of C-X-C motif chemokine 12 (also known as SDF-1) (CXCL12). qRT-PCR and western blot analysis further verified the results and demonstrated that miR-137 could downregulate CXCL12 expression in PTC cells. We also confirmed that CXCL12 expression was increased in PTC tissues and was inversely correlated with miR-137. In addition, our results also showed that downregulation of CXCL12 mimicked the effects of miR-137 overexpression, and upregulation of CXCL12 partially reversed the inhibitory effects of miR-137 in PTC cells. These results showed that miR-137 may function as a tumor suppressor in PTC by targeting CXCL12, suggesting that miR-137 may act as a potential target for PTC treatment.