Therapeutic potential of Dickkopf-1 in wild-type BRAF papillary thyroid cancer via regulation of β-catenin/E-cadherin signaling

Vitamin D receptor regulates proliferation and differentiation of thyroid carcinoma via the E-cadherin-β-catenin complex

Thyroid cancer has the fastest rising incidence among cancers, especially for differentiated thyroid carcinoma (DTC). Although the prognosis of DTC is relatively good, if it changes to anaplastic thyroid carcinoma (ATC), the prognosis will be very poor. The prognosis of DTC is largely depending on the degree of cell differentiation and proliferation. However, whether the vitamin D receptor (VDR) plays a role in regulating the proliferation and the differentiation of DTC cells is unclear. In the present study, we found that VDR was upregulated in DTC tissues compared to the adjacent non-cancerous tissue. Knockdown of VDR increased proliferation and decreased differentiation proliferation in DTC cells in vitro as well as DTC cell-derived xenografts in vivo. In contrast, overexpression of VDR had an opposite effect. Knockdown of E-cadherin abolished VDR-induced suppression of proliferation and enhancement of differentiation of the DTC cells. Knockdown of β-catenin partially reversed the effect of the VDR knockdown. VDR increases the levels of E-cadherin in the plasma membrane and decreases the levels of β-catenin in the nucleus. VDR binds to E-cadherin and β-catenin in the plasma membrane of the DTC cell. Taken together, VDR inhibits DTC cell proliferation and promotes differentiation via regulation of the E-cadherin/β-catenin complex, potentially representing novel clues for a therapeutic strategy to attenuate thyroid cancer progression.

E-cadherin on epithelial-mesenchymal transition in thyroid cancer

Thyroid carcinoma is a common malignant tumor of endocrine system and head and neck. Recurrence, metastasis and high malignant expression after routine treatment are serious clinical problems, so it is of great significance to explore its mechanism and find action targets. Epithelial-mesenchymal transition (EMT) is associated with tumor malignancy and invasion. One key change in tumour EMT is low expression of E-cadherin. Therefore, this article reviews the expression of E-cadherin in thyroid cancers (TC), discuss the potential mechanisms involved, and outline opportunities to exploit E-cadherin on regulating the occurrence of EMT as a critical factor in cancer therapeutics.

Exosomal lncRNA DOCK9-AS2 derived from cancer stem cell-like cells activated Wnt/β-catenin pathway to aggravate stemness, proliferation, migration, and invasion in papillary thyroid carcinoma

Exosomal long non-coding RNAs (lncRNAs) are crucial factors that mediate the extracellular communication in tumor microenvironment. DOCK9 antisense RNA2 (DOCK9-AS2) is an exosomal lncRNA which has not been investigated in papillary thyroid carcinoma (PTC). Based on the result of differentially expressed lncRNAs in PTC via bioinformatics databases, we discovered that DOCK9-AS2 was upregulated in PTC, and presented elevation in plasma exosomes of PTC patients. Functionally, DOCK9-AS2 knockdown reduced proliferation, migration, invasion, epithelial-to-mesenchymal (EMT) and stemness in PTC cells. PTC-CSCs transmitted exosomal DOCK9-AS2 to improve stemness of PTC cells. Mechanistically, DOCK9-AS2 interacted with SP1 to induce catenin beta 1 (CTNNB1) transcription and sponged microRNA-1972 (miR-1972) to upregulate CTNNB1, thereby activating Wnt/β-catenin pathway in PTC cells. In conclusion, PTC-CSCs-derived exosomal lncRNA DOCK9-AS2 activated Wnt/β-catenin pathway to aggravate PTC progression, indicating that DOCK9-AS2 was a potential target for therapies in PTC.

CXCL16 positively correlated with M2-macrophage infiltration, enhanced angiogenesis, and poor prognosis in thyroid cancer

Although various chemokines have pro-tumorigenic actions in cancers, the effects of CXCL16 remain controversial. The aim of this study was to investigate the molecular characteristics of CXCL16-expressing papillary thyroid cancers (PTCs). CXCL16 expressions were significantly higher in PTCs than benign or normal thyroid tissues. In the TCGA dataset for PTCs, a higher CXCL16 expression was associated with M2 macrophage- and angiogenesis-related genes and poor prognostic factors including a higher TNM staging and the BRAF^V600E mutation. PTCs with a higher expression of 3-gene panel including CXCL16, AHNAK2, and THBS2 showed poor recurrence-free survivals than that of the lower expression group. Next, shCXCL16 was introduced into BHP10-3SCp cells to deplete the endogenous CXCL16, and then, the cells were subcutaneously injected to athymic mice. Tumors from the BHP10-3SCp^shCXCL16 exhibited a delayed tumor growth with decreased numbers of ERG⁺ endothelial cells and F4/80⁺ macrophages than those from the BHP10-3SCp^control. CXCL16-related genes including AHNAK2 and THBS2 were downregulated in the tumors from the BHP10-3SCp^shCXCL16 compared with that from the BHP10-3SCp^control. In conclusion, a higher CXCL16 expression was associated with macrophage- and angiogenesis-related genes and aggressive phenotypes in PTC. Targeting CXCL16 may be a good therapeutic strategy for advanced thyroid cancer.

E-cadherin expression is associated with susceptibility and clinicopathological characteristics of thyroid cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Recently, many studies have been carried out to investigate the clinicopathological significance of E-cadherin expression in thyroid cancer. However, the results remained inconsistent. In the present study, we performed a meta-analysis to evaluate the associations of E-cadherin expression with susceptibility and clinicopathological characteristics of thyroid cancer.

METHODS

Eligible studies were searched from Medicine, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases. The strength of associations between E-cadherin expression and susceptibility and clinicopathological features of thyroid cancer were assessed by pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-six studies with 1700 controls and 2298 thyroid cancer patients were included for this meta-analysis. Pooled results indicated that E-cadherin expression was significantly associated with susceptibility of papillary cancer and follicular cancer (papillary cancer, ORs = 14.31, 95% CIs = 3.42-59.90; follicular cancer, ORs = 10.14, 95% CI = 4.52-22.75). Significant association between E-cadherin expression and thyroid cancer risk was also observed in the subgroup analysis based on control group (normal thyroid tissue, ORs = 28.28, 95% CI = 8.36-95.63; adjacent thyroid tissue, ORs = 8.83, 95% CI = 3.27-23.85; benign thyroid tissue, ORs = 43.96, 95% CI = 9.91-194.95). In addition, E-cadherin expression was significantly correlated with lymph node metastasis, differentiation, and tumor-node-metastasis (TNM) stage of thyroid cancer (lymph node metastasis, ORs = 3.21, 95% CI = 1.98-5.20; differentiation, ORs = 0.25, 95% CI = 0.07-0.82; TNM stage, ORs = 4.85, 95% CI = 2.86-8.25).

CONCLUSIONS

The present study showed that E-cadherin expression was significantly associated with susceptibility and clinicopathological characteristics of thyroid cancer, which suggested that E-cadherin expression might be a potential predictive factor for clinical progression of thyroid cancer.

Coding Molecular Determinants of Thyroid Cancer Development and Progression

Thyroid cancer is the most common endocrine malignancy. Its incidence and mortality rates have increased for patients with advanced-stage papillary thyroid cancer. The characterization of the molecular pathways essential in thyroid cancer initiation and progression has made huge progress, underlining the role of intracellular signaling to promote clonal evolution, dedifferentiation, metastasis, and drug resistance. The discovery of genetic alterations that include mutations (BRAF, hTERT), translocations, deletions (eg, 9p), and copy-number gain (eg, 1q) has provided new biological insights with clinical applications. Understanding how molecular pathways interplay is one of the key strategies to develop new therapeutic treatments and improve prognosis.

miR-410 acts as an oncogene in colorectal cancer cells by targeting dickkopf-related protein 1 via the Wnt/β-catenin signaling pathway

Colorectal cancer (CRC) is a common malignancy with high morbidity. MicroRNAs (miRNAs or miRs) have been demonstrated to be critical post-transcriptional regulators in tumorigenesis. The current study aimed to investigate the effect of miR-410 on the proliferation and metastasis of CRC. The expression of miR-410 was examined in CRC cell lines. SW-480 and HCT-116 CRC cell lines were employed and transfected with miR-410 inhibitor or miR-410 mimics. The association between miR-410 and dickkopf-related protein 1 (DKK-1) was verified by luciferase reporter assay. Cell viability and apoptosis were detected by Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Cell migration and invasion capacity were determined by Transwell assay. The protein level of DKK1, β-catenin and phosphorylated glycogen synthase kinase-3β (pGSK-3β) were analyzed by western blotting. miR-410 was revealed to be upregulated in CRC cell lines. Further studies identified DKK-1 as a direct target of miR-410. In addition, knockdown of miR-410 promoted the expression of DKK, inhibited CRC cell proliferation, migration and invasion capacity, and induced cell apoptosis, while overexpression of miR-410 reversed these results. miR-410 silencing also decreased β-catenin and pGSK-3β levels. The current study indicated that miR-410 negatively regulates the expression of DKK-1 in vitro. miR-410 promotes malignancy phenotypes in CRC cell lines. This regulatory effect of miR-410 may be associated with the Wnt/β-catenin signaling pathway. Therefore, miR-410 could be used as a biomarker for predicting the progression of CRC.

Macrophage Densities Correlated with CXC Chemokine Receptor 4 Expression and Related with Poor Survival in Anaplastic Thyroid Cancer

BACKGROUND

Tumor associated macrophages (TAMs) and CXC chemokine receptor 4 (CXCR4) have emerged as potential biomarkers in various human cancers. The aims of this study were to investigate the clinical characteristics of anaplastic thyroid cancer (ATC) patients according to the TAM numbers in the tumor tissue, and to evaluate the associations between CXCR4 expressions and macrophage densities in ATC tumor microenvironment.

METHODS

Total 14 ATC samples from thyroid tissue microarray were used. Immunohistochemical staining was performed using anti-CD163 and anti-CXCR4 antibodies. According to the immunoreactivity of CD163, all subjects were divided into two groups: low-CD163 (n=8) and high-CD163 (n=6) groups.

RESULTS

The mean diagnostic age was 65±7 years and the median tumor size was 4.3 cm, ranging 2.5 to 15 cm. Clinicopathological characteristics were not significantly different between low-CD163 and high-CD163 groups, while age of diagnosis was younger in high-CD163 group than that of low-CD163 group with marginal significance (56.9±5.5 years vs. 67.5±6.8 years, P=0.09). However, overall survival was significantly reduced in high-CD163 group (5.5 months [range, 1 to 10]) compared with low-CD163 groups (8.8 months [range, 6 to 121); log-rank test, P=0.0443). Moreover, high-CD163 group showed strong CXCR4 expressions in both cancer and stromal compartments, while low-CD163 group showed relatively weak, stromal-dominant CXCR4 expressions. Additionally, CD163 and CXCR4 expressions showed a strong positive correlation (γ²=0.432, P=0.013).

CONCLUSION

Increased number of TAMs showed poor overall survival in ATC, suggesting TAMs are potentially a prognostic biomarker for ATC. CXCR4 expression was significantly correlated with CD163-positive TAM densities, which suggest the possible role of CXCR4 in TAM recruitments.

Nuclear DICKKOPF-1 as a biomarker of chemoresistance and poor clinical outcome in colorectal cancer

Sporadic colorectal cancer (CRC) insurgence and progression depend on the activation of Wnt/β-catenin signaling. Dickkopf (DKK)-1 is an extracellular inhibitor of Wnt/β-catenin signaling that also has undefined β-catenin-independent actions. Here we report for the first time that a proportion of DKK-1 locates within the nucleus of healthy small intestine and colon mucosa, and of CRC cells at specific chromatin sites of active transcription. Moreover, we show that DKK-1 regulates several cancer-related genes including the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) and Ral-binding protein 1-associated Eps domain-containing 2 (REPS2), which are involved in detoxification of chemotherapeutic agents. Nuclear DKK-1 expression is lost along CRC progression; however, it remains high in a subset (15%) of CRC patients (n = 699) and associates with decreased progression-free survival (PFS) after chemotherapy administration and overall survival (OS) [adjusted HR, 1.65; 95% confidence interval (CI), 1.23-2.21; P = 0.002)]. Overexpression of ALDH1A1 and REPS2 associates with nuclear DKK-1 expression in tumors and correlates with decreased OS (P = 0.001 and 0.014) and PFS. In summary, our findings demonstrate a novel location of DKK-1 within the cell nucleus and support a role of nuclear DKK-1 as a predictive biomarker of chemoresistance in colorectal cancer.

CXCL16 signaling mediated macrophage effects on tumor invasion of papillary thyroid carcinoma

Macrophages in tumor microenvironment have pivotal roles in tumor growth, metastasis, and angiogenesis. We investigated the interacting mechanism of macrophage actions in human papillary thyroid cancer (PTC). Co-cultures of macrophage/PTC significantly increased the cancer cell migration potentials, compared with the PTC culture alone. Treatment of conditioned medium (CM) of macrophage/PTC co-cultures enhanced cell invasions in 3D invasion assay. Cytokine array analysis demonstrated that CM of macrophage/PTC co-cultures contained a high level of CXCL16, while it was not found in CM of PTC culture alone. Treatment with CXCL16 enhanced the cell migration potentials in PTC cells, and blocking CXCL16 signaling using anti-CXCL16 antibody or metalloproteinase inhibitor (TAPI2) attenuated macrophage-mediated enhancement of PTC cell migration potentials. In PTC cells, CXCL16 treatment or co-cultures with macrophages increased Akt phosphorylation, and these macrophage-dependent increases of Akt phosphorylation was inhibited by anti-CXCL16 antibody. Moreover, Akt inhibitor attenuated macrophage-mediated increases of PTC cell migration potential. In macrophages, treatment of macrophage/PTC co-cultured CMs up-regulated CD163, Il10, and CD206, which were attenuated by anti-CXCL16 antibody treatment. Finally, CXCR6 and CXCL16 expressions were evaluated by immunohistochemical staining with a thyroid tissue microarray including 136 PTC. CXCR6 expressions showed positive correlation with the density of CD163(+) macrophages and associated with lymph node metastasis. In conclusion, CXCL16 signaling partly mediated macrophage actions on PTC tumor cell invasion and also changed the macrophage phenotypes into M2-macrophages in PTC tumor microenvironment. These data suggested that CXCL16 signaling, a bidirectional player in macrophage-associated tumor microenvironment, might be a potential therapeutic target of human PTC.

Cancers with Higher Density of Tumor-Associated Macrophages Were Associated with Poor Survival Rates

Background:

Macrophages are a component of a tumor’s microenvironment and have various roles in tumor progression and metastasis. This study evaluated the relationships between tumor-associated macrophage (TAM) density and clinical outcomes in 14 different types of human cancers.

Methods:

We investigated TAM density in human tissue microarray sections from 14 different types of human cancers (n = 266) and normal thyroid, lung, and breast tissues (n = 22). The five-year survival rates of each cancer were obtained from the 2011 Korea Central Cancer Registry.

Results:

Among 13 human cancers, excluding thyroid cancer, pancreas, lung, and gallbladder cancers had the highest density of CD163-positive macrophages (7.0±3.5%, 6.9±7.4%, and 6.9 ± 5.5%, respectively). The five-year relative survival rates of these cancers (pancreas, 8.7%; lung, 20.7%; gallbladder, 27.5%) were lower than those of other cancers. The histological subtypes in thyroid cancer exhibited significantly different CD163-positive macrophages densities (papillary, 1.8 ± 1.6% vs anaplastic, 22.9 ± 17.1%; p < .001), but no significant difference between histological subtypes was detected in lung and breast cancers. Moreover, there was no significant difference in CD163-positive macrophages densities among the TNM stages in lung, breast, and thyroid cancers.

Conclusions:

Cancers with higher TAM densities (pancreas, lung, anaplastic thyroid, and gallbladder) were associated with poor survival rate.