Structural alterations in tumor-draining lymph nodes before papillary thyroid carcinoma metastasis

The expression of HDAC9 and P300 in papillary thyroid carcinoma cell line

PURPOSE

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer and accounts for 85-90% of all thyroid cancers. Metastatic differentiated thyroid cancer, radioiodine-refractory thyroid cancer, and anaplastic thyroid cancer still lack effective therapeutic options. Here, we aimed to assess HDAC9 and P300 expression in the papillary thyroid carcinoma cell line and compare them with normal thyroid cells.

METHODS

Nthy-ori-3-1, a normal thyroid cell line, and BCPAP, a PTC cell line, were cultured for 24 and 48 h and immunofluorescence staining was used to determine the levels of HDAC9 and P300 protein expression. HDAC9 paracrine release was assessed using an ELISA assay.

RESULTS

HDAC9 protein expression was higher in both cell groups at the 48th hour than at the 24th hour; however, P300 protein expression was lower in BCPAP cells at the 48th hour than at the 24th hour. In comparison to Nthy-ori-3-1, BCPAP expressed more HDAC9 and P300 proteins. HDAC9 secretion slightly increased in Nthy-ori-3-1 cells from 24 to 48 h. Furthermore, HDAC9 secretion in BCPAP cells dramatically decreased from 24 to 48 h.

CONCLUSION

Our findings revealed that the expression of HDAC9 and P300 was higher in the PTC cell line than in normal thyroid cells. This indicates that the acetylation mechanism in thyroid cancer cells is not the same as it is in healthy cells. Epigenetic studies may reveal the mechanisms underlying PTC with further analysis.

Pivotal roles of tumor-draining lymph nodes in the abscopal effects from combined immunotherapy and radiotherapy

BACKGROUND

Currently, due to synergy enhancement of anti-tumor effects and potent stimulation of abscopal effects, combination therapy with irradiation and programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint inhibition (immuno-radiotherapy, iRT) has revolutionized the therapeutic guidelines. It has been demonstrated that tumor-draining lymph nodes (TDLN) are essential for effective antitumor immunity induced by radiotherapy, immunotherapy, or iRT. Given that the function of TDLN in iRT remains unclear, this study aimed to investigate the function and mechanism of TDLN in iRT-induced abscopal effects.

METHODS

The function of TDLN was evaluated using unilateral or bilateral MC38 and B16F10 subcutaneous tumor models with or without indicated TDLN. The flow cytometry, multiple immunofluorescence analysis, and NanoString analysis were utilized to detect the composition and function of the immune cells in the primary and abscopal tumor microenvironment. Additionally, we tempted to interrogate the possible mechanisms via RNA-sequencing of tumor-infiltrating lymphocytes and TDLN.

RESULTS

TDLN deficiency impaired the control of tumor growth by monotherapy. Bilateral TDLN removal rather than unilateral TDLN removal substantially curtailed iRT-stimulated anti-tumor and abscopal effects. Furthermore, in the absence of TDLN, the infiltration of CD45⁺ and CD8⁺ T cells was substantially reduced in both primary and abscopal tumors, and the anti-tumor function of CD8⁺ T cells was attenuated as well. Additionally, the polarization of tumor-associated macrophages in primary and abscopal tumors were found to be dependent on intact bilateral TDLN. RNA-sequencing data indicated that impaired infiltration and anti-tumor effects of immune cells partially attributed to the altered secretion of components from the tumor microenvironment.

CONCLUSIONS

TDLN play a critical role in iRT by promoting the infiltration of CD8⁺ T cells and maintaining the M1/M2 macrophage ratio.

Charge Reversal Polypyrrole Nanocomplex-Mediated Gene Delivery and Photothermal Therapy for Effectively Treating Papillary Thyroid Cancer and Inhibiting Lymphatic Metastasis

As a traditional treatment for papillary thyroid cancer (PTC), surgical resection of diseased tissues often brings lots of inconveniences to patients, and the tumor recurrence and metastasis are difficult to avoid. Herein, we developed a gene and photothermal combined therapy nanosystem based on a polypyrrole (Ppy)-poly(ethylene imine)-siILK nanocomplex (PPR_ILK) to achieve minimally invasive ablation and lymphatic metastasis inhibition in PTC simultaneously. In this system, gelatin-stabilized Ppy mainly acted as a photothermal- and photoacoustic (PA)-responsive nanomaterial and contributed to its well-behaved photosensitivity in the near-infrared region. Moreover, gelatin-stabilized Ppy possessed a charge reversal function, facilitating the tight conjunction of siILK gene at physiological pH (7.35-7.45) and its automatic release into acidic lysosomes (pH 4.0-5.5); the proton sponge effect generated during this process further facilitated the escape of siILK from lysosomes to the cytoplasm and played its role in inhibiting PTC proliferation and lymphatic metastasis. With the guidance of fluorescence and PA bimodal imaging, gene delivery and Ppy location in tumor regions could be clearly observed. As a result, tumors were completely eradicated by photothermal therapy, and the recurrences and metastases were obviously restrained by siILK.

LEM domain containing 1 promotes thyroid cancer cell proliferation and migration by activating the Wnt/β-catenin signaling pathway and epithelial-mesenchymal transition

Thyroid cancer (TC) is the most common type of endocrine malignancy in humans, and its relative incidence has increased continuously in recent years. However, the primary molecular mechanisms of thyroid tumorigenesis and progression remain unclear. Papillary TC (PTC) is the most common subtype of TC. Recent studies have reported that one of the tumorigenesis and progression mechanisms is driven by genetic alterations that regulate the TC cell signaling pathway. In the present study, RNA sequencing (RNA-seq) was performed on 79 paired PTC and adjacent normal thyroid tissues to further study the molecular mechanisms of TC. Reverse transcription-quantitative PCR was used to detect the expression levels of LEM domain containing 1 (LEMD1) in 47 paired PTC and adjacent normal thyroid tissue samples. Initial analysis revealed that LEMD1 expression was significantly upregulated in TC tissues compared with that in normal tissues. The results of the thyroid RNA-seq datasets from The Cancer Genome Atlas were consistent with the RNA-seq analysis results of the present study. High LEMD1 expression increased the risk of lymph node metastasis in patients with TC. The biological function of LEMD1 on cell proliferation, migration, invasion and apoptosis was investigated in vitro via small interfering RNA and overexpression vector. Gene set enrichment analysis indicated that high LEMD1 expression was associated with epithelial-mesenchymal transition (EMT) and the Wnt/β-catenin signaling pathway. Western blotting revealed that LEMD1 modulated the protein expression levels of E-cadherin, N-cadherin, vimentin, β-catenin and cleaved-caspase 3. In conclusion, the present results indicated that LEMD1 may drive TC cell tumorigenesis and progression by activating the Wnt/β-catenin signaling pathway and EMT.

Lymph Node Subcapsular Sinus Microenvironment-On-A-Chip Modeling Shear Flow Relevant to Lymphatic Metastasis and Immune Cell Homing

A lymph node sinus-on-a-chip adhesion microfluidic platform that recapitulates the hydrodynamic microenvironment of the lymph node subcapsular sinus was engineered. This device was used to interrogate the effects of lymph node remodeling on cellular adhesion in fluid flow relevant to lymphatic metastasis. Wall shear stress levels analytically estimated and modeled after quiescent and diseased/inflamed lymph nodes were experimentally recapitulated using a flow-based microfluidic perfusion system to assess the effects of physiological flow fields on human metastatic cancer cell adhesion. Results suggest that both altered fluid flow profiles and presentation of adhesive ligands, which are predicted to manifest within the lymph node subcapsular sinus as a result of inflammation-induced remodeling, and the presence of lymph-borne monocytic cells may synergistically contribute to the dynamic extent of cell adhesion in flow relevant to lymph node invasion by cancer and monocytic immune cells during lymphatic metastasis.

Growth-associated protein 43 promotes thyroid cancer cell lines progression via epithelial-mesenchymal transition

Thyroid cancer is maintaining at a high incidence level and its carcinogenesis is mainly affected by a complex gene interaction. By analysis of the next‐generation resequencing of paired papillary thyroid cancer (PTC) and adjacent thyroid tissues, we found that Growth Associated Protein 43 (GAP43), a phosphoprotein activated by protein kinase C, might be novel markers associated with PTC. However, its function in thyroid carcinoma has been poorly understood. We discovered that GAP43 was significantly overexpressed in thyroid carcinoma and these results were consistent with that in The Cancer Genome Atlas (TCGA) cohort. In addition, some clinicopathological features of GAP43 in TCGA database showed that up‐regulated GAP43 is significantly connected to lymph node metastasis (P < 0.001) and tumour size (P = 0.038). In vitro experiments, loss of function experiments was performed to investigate GAP43 in PTC cell lines (TPC‐1 and BCPAP). The results proved that GAP43 knockdown in PTC cell significantly decreased the function of cell proliferation, colony formation, migration, and invasion and induced cell apoptosis. Furthermore, we also indicated that GAP43 could modulate the expression of epithelial‐mesenchymal transition‐related proteins, which could influence invasion and migration. Put those results together, GAP43 is a gene which was associated with PTC and might be a potential therapeutic target.

NECTIN4 promotes papillary thyroid cancer cell proliferation, migration, and invasion and triggers EMT by activating AKT

Papillary thyroid cancer (PTC) is the most frequent type of malignant thyroid cancer, but its molecular mechanisms remain unknown. To better understand the tumorigenesis and progression of PTC, we conducted a comprehensive analysis of the whole-transcriptome resequencing of paired PTC and normal thyroid tissues. Nectin cell adhesion molecule 4 (NECTIN4) was significantly overexpressed in thyroid carcinoma compared with that in matched normal tissue. We also assessed the relation between the expression level of NECTIN4 and the clinicopathological features of PTC in The Cancer Genome Atlas database, and results showed that upregulated NECTIN4 is associated with lymph node metastasis (P<0.001) and tumor size (P=0.017). The biological function of NECTIN4 was also investigated by using the PTC cell lines TPC-1 and KTC-1. In vitro experiments demonstrated that NECTIN4 downregulation significantly inhibits the colony formation, proliferation, migration, and invasion of PTC cell lines. NECTIN4 could modulate the expression of epithelial-mesenchymal transition-related proteins via the PI3K/AKT pathway, and SC79, an AKT phosphorylation activator, could reverse the si-RNA knockdown effect. In addition, after the use of AKT inhibitors (LY 294,002), we found that SiRNA have similar effect with AKT inhibitors. Taking the results together, the current study shows that NECTIN4 has important biological implications in the tumorigenesis and metastasis of PTC and may be a potential therapeutic target for the disease.

Lipase member H is a downstream molecular target of hypoxia inducible factor-1α and promotes papillary thyroid carcinoma cell migration in BCPAP and KTC-1 cell lines

Background

Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma, which is associated with a high incidence of lymph-node metastasis. Multiple biomarkers have been identified for the precise diagnosis of PTC at an early stage. However, their role in PTC remains poorly elucidated. Previously, we reported that lipase H (LIPH), a membrane-bound protein, was highly expressed in PTC. This study aimed to fully elucidate the causal role of LIPH in the development of PTC and investigated its relationship with lymph-node metastasis in PTC.

Materials and methods

Quantitative reverse transcription PCR and immunohistochemistry were used to measure the mRNA and protein expression levels of LIPH in 45 and 6 pairs of PTC tissues and adjacent normal tissues, respectively. Clinical tissue data of 504 PTC tissues and 60 normal thyroid tissues from The Cancer Genome Atlas database were used to analyze the correlation between LIPH expression level and clinical features in PTC. siRNAs were used to knock down genes, while plasmids were used to overexpress genes. Two PTC cell lines (KTC-1 and BCPAP) were used in subsequent cytological function studies. In addition, a hypoxia stress model was constructed using cobaltous chloride hexahydrate reagent, and the protein expression level of the corresponding biomarkers was measured by Western blotting.

Results

This study revealed that high expression of LIPH in PTC was closely associated with lymph-node metastasis. Our cellular function experiments indicated that LIPH positively correlated with the malignant behavior of PTC cell lines. We further confirmed the role of LIPH in hypoxia and its relationship with the epithelial–mesenchymal transition pathway in PTC.

Conclusion

LIPH plays an important role in PTC oncogenesis and development, especially in lymph-node metastasis. It can be regarded as a biomarker for the diagnosis and treatment of PTC in the near future.

CLDN10 is Associated with Papillary Thyroid Cancer Progression

The incidence of thyroid cancer is staying at a high level. Claudin family is a skelemin contacting with the intercellular junction and can keep a dynamic balance between cells. Recently, many types of research indicated that the expression level of claudins is closely related to various cancer types and they can be novel diagnostic markers. For instance, Claudin-10(CLDN10) is the high expression in primary hepatocellular carcinoma, papillary thyroid cancer (PTC) and so on. But the biological role and function of CLDN10 in PTC are unclear. In our study, we measured the expression of CLDN10 in human normal tissues and matched PTC tissues by quantitative real-time polymerase chain reaction (qRT-PCR) and this observation was consistent with that in the TCGA cohort. We discovered that high expression of CLDN10 was correlated with lymph node metastasis, age and Histological type in TCGA cohorts. Kaplan-Meier analysis showed that patients with higher CLDN10 expression had a worse overall survival. In vitro, CLDN10 could promote cellular proliferation, migration, and invasion in PTC cell lines. In a word, CLDN10 is a functionally gene facilitating tumorgenesis in PTC and acts as an oncogene in PTC.

GABRB2 plays an important role in the lymph node metastasis of papillary thyroid cancer

BACKGROUND

Thyroid cancer is a common malignant tumor of the endocrine system. Its incidence has increased continuously worldwide for the past three decades. With advanced sequencing technology, we discovered that GABRB2 gene is overexpressed in tumor tissues and closely associated with vertebrate nervous systems. However, its role in cancer remains unclear.

METHODS

We conducted a massively parallel whole transcriptome resequencing and a comprehensive analysis of matched papillary thyroid carcinoma (PTC) tumors and normal tissues in 19 patients. Results showed that GABRB2 expression was significantly upregulated in thyroid cancer. Forty-five pairs of tumors and normal tissues were subjected to reverse transcription polymerase chain reaction to validate previous findings. The specific functions of GABRB2 in PTC cell lines (BCPAP, TPC1, and KTC-1) transfected with small interfering RNA were determined through cell colony formation, Cell Counting Kit-8, Transwell migration, Transwell invasion, and apoptosis assays. The effect of DNA demethylation on this gene was also examined.

RESULTS

GABRB2 was remarkably overexpressed in primarily sequenced PTC tumors and validation cohort (T: N = 4.94 ± 3.43:0.83 ± 1.71, P < 0.001), and this observation was consistent with that in the TCGA cohort (T: N = 38.92 ± 35.53:0.30 ± 0.55, P < 0.001). GABRB2 overexpression was correlated with lymph node metastasis in both cohorts (P < 0.01). In vitro experiments revealed that GABRB2 downregulation significantly inhibited the colony formation, migration, and invasion of the three PTC cell lines.

CONCLUSION

GABRB2 plays important tumorigenic functions and acts as a novel oncogene in PTC.