IL-34 is a potential biomarker for the treatment of papillary thyroid cancer

Immune microenvironment in papillary thyroid carcinoma: roles of immune cells and checkpoints in disease progression and therapeutic implications

Papillary thyroid cancer (PTC) is the most common type of primary thyroid cancer. Despite the low malignancy and relatively good prognosis, some PTC cases are highly aggressive and even develop refractory cancer in the thyroid. Growing evidence suggested that microenvironment in tumor affected PTC biological behavior due to different immune states. Different interconnected components in the immune system influence and participate in tumor invasion, and are closely related to PTC metastasis. Immune cells and molecules are widely distributed in PTC tissues. Their quantity and proportion vary with the host's immune status, which suggests that immunotherapy may be a very promising therapeutic modality for PTC. In this paper, we review the role of immune cells and immune checkpoints in PTC immune microenvironment based on the characteristics of the PTC tumor microenvironment.

[Expression of interleukin-34 in tongue squamous cell carcinoma and its clinical implications]

OBJECTIVE

To investigate the expression of interleukin- 34 (IL-34) in tongue squamous cell carcinoma (TSCC) and its clinical implications.

METHODS

Serum IL-34 level was detected in 36 patients with TSCC and 36 healthy individuals using enzymelinked immunosorbent assay (ELISA). The expressions of IL-34 mRNA and protein levels in TSCC and adjacent tissues were examined in 41 patients using real-time fluorescence quantitative PCR (qRT-PCR) and immunohistochemistry (IHC), and their correlation with the clinicopathological features of the patients was further analyzed. Informatic analysis of the differentially expressed genes related with IL-34 in TSCC was carried out based on String database, LinkedOmics database and GEO database, and GO functional analysis and KEGG signaling pathway enrichment analysis were performed using Webgestalt database.

RESULTS

The serum level of IL-34 was significantly lower in TSCC patients than in the healthy individuals (P < 0.001), and its expression level was also significantly lower in the tumor tissues than in the adjacent tissues (P < 0.001). The expression level of IL-34 in TSCC tissues was related with lymph node metastasis and TNM staging (P < 0.05), but not with age, gender, smoking, drinking, or tumor size (P > 0.05). Informatic analysis suggested that IL-34 had the strongest correlation with CSF1R and PTPRJ. IL-34 and its related genes in TSCC were enriched mainly in bone marrow cell differentiation, collagen-containing extracellular matrix, and cytokine binding and signal receptor activator activity. KEGG signaling pathway enrichment showed that IL-34 and the related differentially expressed genes were involved mainly in osteoclast differentiation, protein polysaccharide in cancer, and the MAPK signaling pathway.

CONCLUSION

IL-34 is lowly expressed in TSCC and participates in the occurrence and progression of TSCC, and can be potentially used as a new diagnostic biomarker and therapeutic target for TSCC.

Interleukin-34 promotes the proliferation and epithelial-mesenchymal transition of gastric cancer cells

BACKGROUND

Interleukin (IL)-34 is a pro-inflammatory cytokine involved in tumor development. The role of IL-34 in the proliferation and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) remains to be investigated.

AIM

To investigate whether and how IL-34 affects the proliferation of GC cells and EMT.

METHODS

Using immunohistochemical staining, the expression of IL-34 protein was detected in 60 paired GC and normal paracancerous tissues and the relationship between IL-34 and clinicopathological factors was analyzed. The expression of IL-34 mRNA and protein in normal gastric epithelial cell lines and GC was detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, respectively. Stable IL-34 knockdown and overexpression in AGS cell lines were established by lentiviral infection and validated by qRT-PCR and western blotting. The cholecystokinin-8 assay, clone formation assay, cell scratch assay, and transwell system were used to detect GC cell proliferation, clone formation, migration, and invasion capacity, respectively. The effects of IL-34 on the growth of GC transplant tumors were assessed using a subcutaneous transplant tumor assay in nude mice. The effects of IL-34 on the expression level of EMT-associated proteins in AGS cells were examined by western blotting.

RESULTS

Expression of IL-34 protein and mRNA was higher in GC cell lines than in GES-1 cells. Compared to matched normal paraneoplastic tissues, the expression of IL-34 protein was higher in 60 GC tissues, which was correlated with tumor size, T-stage, N-stage, tumor, node and metastasis stage, and degree of differentiation. Knockdown of IL-34 expression inhibited the proliferation, clone formation, migration, and invasion of AGS cells, while overexpression of IL-34 promoted cell proliferation, clone formation, migration, and invasion. Furthermore, the reduction of IL-34 promoted the expression of E-cadherin in AGS cells but inhibited the expression of vimentin and N-cadherin. Overexpression of IL-34 inhibited E-cadherin expression but promoted expression of vimentin and N-cadherin in AGS cells. Overexpression of IL-34 promoted the growth of subcutaneous transplanted tumors in nude mice.

CONCLUSION

IL-34 expression is increased in GC tissues and cell lines compared to normal gastric tissues or cell lines. In GC cells, IL-34 promoted proliferation, clone formation, migration, and invasion by regulating EMT-related protein expression cells. Interference with IL-34 may represent a novel strategy for diagnosis and targeted therapy of GC.

Analysis of anti-apoptotic PVT1 oncogene and apoptosis-related proteins (p53, Bcl2, PD-1, and PD-L1) expression in thyroid carcinoma

BACKGROUND

An aberrant expression of long non-coding RNA PVT1 has been associated with apoptosis in various cancer types. We aimed to explore the PVT1 and four apoptosis-related proteins (p53, Bcl2, and PD-1/PD-L1) signature in thyroid cancer (TC).

METHODS

The PVT1 expression level was measured in 64 FFPE TC paired samples by real-time quantitative PCR. Overall and stratified analyses by different clinicopathological features were done. The apoptotic proteins were evaluated by immunohistochemistry staining.

RESULTS

Overall analysis showed significant PVT1upregulation in TC tissues (p < 0.001). Similarly, subgroup analysis by BRAFV600E mutation showed consistent results. Lower expression of p53 was associated with mortality (p = 0.001). Bcl2 overexpression was associated with greater tumor size (p = 0.005). At the same time, HCV-positive cases were associated with repressed Bcl2 expression levels (54.3% in HCV-negative vs. 6.9% in HCV-positive cases, p = 0.011). PD-1 expression was associated with lymph node metastasis (p = 0.004). Enhanced PD-L1 expression in the tumor was associated with a higher tumor stage, lymphovascular invasion, and mortality risk. Kaplan-Meier curves for overall survival showed that low p53 and high PD-L1 expressions were associated with lower survival time. The p53-positive staining is associated with a 90% decreased mortality risk (HR = 0.10, 95%CI = 0.02-0.47, p = 0.001), while patients with high PD-L1 were five times more likely to die (HR = 4.74, 95%CI = 1.2-18.7, p = 0.027).

CONCLUSION

Our results confirm the upregulation of PVT1 in TC. The apoptosis-related proteins (p53, Bcl2, and PD-1/PD-L1) showed different prognostic utility in TC patients; in particular, low p53 and high PD-L1 expressions associated with low survival times. Further large-scale and mechanistic studies are warranted.

Semaphorin 3D inhibits proliferation and migration of papillary thyroid carcinoma by regulating MAPK/ERK signaling pathway

BACKGROUND

Semaphorin 3D (SEMA3D) plays an important role in the occurrence and development of multifarious cancers. However, the relationship between SEMA3D and papillary thyroid carcinoma (PTC) remains unclear. This study aimed to investigate the functions and mechanism of SEMA3D in papillary thyroid carcinoma (PTC).

METHODS

The expression of SEMA3D in PTC tissues and cell lines was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blotting and immunohistochemistry (IHC) were used to detect the expression of the related proteins. CCK-8 and colony formation assays and Transwell assays were used to evaluate cell proliferation and migration, respectively. A xenograft model was induced to further verify the effect of SEMA3D in vivo.

RESULTS

In this study, we found that SEMA3D was downregulated in PTC tissues and PTC cell lines (TPC-1 and BCPAP). The expression level of SEMA3D was significantly related to age (P < 0.01), extrathyroidal extension (P < 0.01), TNM stage (P < 0.01) and lymph node metastasis (P < 0.01). In vitro experiments showed that overexpression of SEMA3D inhibited the proliferation and migration of TPC-1 and BCPAP cells and that upregulated SEMA3D inhibited the phosphorylation of ERK and the expression of the phenotype-related proteins PCNA and MMP2. In addition, SEMA3D overexpression inhibited tumour growth in vivo.

CONCLUSION

In this study, we found that SEMA3D is significantly downregulated in PTC tissues. SEMA3D inhibits the proliferation and migration of PTC cells and suppresses tumour growth in vivo, possibly partially through the MAPK/ERK signalling pathway, suggesting that SEMA3D may be a reliable molecular marker for the diagnosis and treatment of PTC.

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.

IL-34 and CSF-1, deciphering similarities and differences at steady state and in diseases

Although IL-34 and CSF-1 share actions as key mediators of monocytes/macrophages survival and differentiation, they also display differences that should be identified to better define their respective roles in health and diseases. IL-34 displays low sequence homology with CSF-1 but has a similar general structure and they both bind to a common receptor CSF-1R, although binding and subsequent intracellular signaling shows differences. CSF-1R expression has been until now mainly described at a steady state in monocytes/macrophages and myeloid dendritic cells, as well as in some cancers. IL-34 has also 2 other receptors, protein-tyrosine phosphatase zeta (PTPζ) and CD138 (Syndecan-1), expressed in some epithelium, cells of the central nervous system (CNS), as well as in numerous cancers. While most, if not all, of CSF-1 actions are mediated through monocyte/macrophages, IL-34 has also other potential actions through PTPζ and CD138. Additionally, IL-34 and CSF-1 are produced by different cells in different tissues. This review describes and discusses similarities and differences between IL-34 and CSF-1 at steady state and in pathological situations and identifies possible ways to target IL-34, CSF-1, and its receptors.

IL-34 is a potential biomarker for the treatment of papillary thyroid cancer

Background

Interleukin (IL)‐34 is a recently discovered pro‐inflammatory cytokine and is a vital regulator in different tumor types. However, the function of IL‐34 in thyroid carcinoma has yet to be investigated. In this study, we analyzed the expression of IL‐34 in human papillary thyroid cancer (PTC) samples and determined its effects on the proliferation and apoptosis of PTC cells.

Methods

We examined the expression of IL‐34 in serum and tissue samples of patients with PTC by Western blotting and ELISA assay and analyzed its association with clinicopathological features including tumor size, tumor node metastasis (TNM) stage, and lymph node metastasis (LNM). We selected TPC1 and K1 for knockdown or overexpressing of IL‐34 via small interference RNA transfection. The proliferation of PTC cells was evaluated by CCK8 assay. We further investigated the role of IL‐34 in apoptosis by flow cytometry and studied the protein levels of epithelial‐mesenchymal transition (EMT) biomarkers, phosphorylated extracellular‐regulated kinase (ERK), and total‐ERK (t‐ERK) by Western blotting.

Results

Our results show that IL‐34 is significantly upregulated in serum and tissue samples from patients with PTC. IL‐34 promotes the proliferation and suppresses apoptosis in PTC cells. In addition, IL‐34 can promote the EMT and activate ERK signaling pathway in PTC cells.

Conclusion

This study provides novel evidence that IL‐34 serves as an oncogene in PTC. IL‐34 promotes proliferation, EMT phenotype, and ERK signaling pathway and inhibits apoptosis in PTC cells. Therefore, IL‐34 may be a potent therapeutic target for the treatment of PTC.