MiR-181a-5p Regulates NIS Expression in Papillary Thyroid Carcinoma

An age-and sex-matched postoperative therapy should be required in thyroid papillary carcinoma

Background and purpose

Thyroid papillary carcinoma (PTC) had a high possibility of recurrence after surgery, and thyroid stimulating hormone (TSH) suppression and radioactive iodine (131I) were used for postoperative therapy. This study explored the potential mechanism of lymph node metastasis (LNM) and aimed to develop differentiated treatments for PTC.

Method

This study explored the risk factors of lymph node metastasis in PTC by analyzing the clinical information of 2073 cases. The Cancer Genome Atlas Thyroid Cancer (TCGA-THCA) and the Gene Expression Omnibus (GEO) databases of gene expression were analyzed to identify the interrelationships between gene expression to phenotype.

Results

Analyzing clinical data, we found that male gender, younger age, larger tumor size, and extra-thyroidal extension (ETE) were risk significant risk factors for lymph node metastasis(P<0.05). Conversely, thyroid function parameters such as TSH, FT3, FT4, TSH/FT3, and TSH/FT4 didn't correlate with LNM(P>0.05), and TSH levels were observed to be higher in females(P<0.05). Gene expression analysis revealed that SLC5A5 was down-regulated in males, younger individuals, and those with lymph node metastasis, and a lower level of SLC5A5 was associated with a worse disease-free survival(P<0.05). Additionally, our examination of single-cell RNA sequencing (scRNA-seq) data indicated that SLC5A5 expression was reduced in tumors and lymph node metastasis samples, correlating positively with the expression of TSHR.

Conclusion

The impact of TSH on PTC behavior remained unclear, while the capacity for absorbing 131I in dependence on SLC5A5 showed variations across different genders and ages. We conclude that postoperative treatment of PTC should take into account the differences caused by gender and age.

Role of sodium/iodide symporter overexpression in inhibiting thyroid cancer cell invasion and stem cell maintenance by inhibiting the β-catenin/LEF-1 pathway

Background

In thyroid cancers, a reduction in the expression of the sodium/iodide symporter (NIS) is observed concomitant with a diminution in cancer cell differentiation. The β-catenin/LEF-1 pathway emerges as a crucial regulatory pathway influencing the functional expression of NIS in human thyroid cancer cells. Further research is required to comprehensively elucidate the role of NIS overexpression in impeding the progression of thyroid cancer cells.

Methods

Human papillary thyroid carcinoma (PTC) cell lines, specifically PTC-1 and KTC-1, were subjected to Scratch and Transwell assays, colony formation, and tumor sphere formation tests to investigate invasion and migration, focusing on the impact of NIS overexpression. The assessment involved the use of western blot to analyze the expression levels of β-catenin, NIS, CD133, SRY-related HMG box2 (Sox2), lymphoid enhancer-binding factor 1 (LEF-1), NANOG, octamer-binding transcription factor 4 (Oct4), aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), and epithelial cellular adhesion molecule (EpCAM). Statistical analysis was conducted using SPSS version 20.0, and the graphs were developed using GraphPad Prism 7 (GraphPad Software, Inc.).

Results

Our observations revealed that Nthy-ori-3-1 cell lines exhibited notably higher average expression levels of NIS, yet significantly lower levels of LEF-1 and β-catenin compared to PTC-1 and KTC-1 cell lines. Furthermore, the overexpression of β-catenin resulted in reduced binding of LEF-1 to NIF promotion but concurrently increased the expression of NIS. The downregulation of NIS markedly enhanced the expression of ALDH1A1, CD133, OCT4, Nanog, SOX2, and EpCam-all of which are targets within the Wnt/β-catenin signaling pathway. Conversely, the upregulation of NIS suppressed the expression of these proteins. Moreover, cells treated with β-catenin activators demonstrated an increased capability to form more spheroids and displayed heightened aggressiveness. Conversely, the NIS overexpression (OE) group exhibited suppressed abilities in invasion and colony formation.

Conclusion

Thyroid cancer cells exhibit diminished expression of NIS, and the invasion and maintenance of stem cells in thyroid cancer cells were hindered by NIS OE through the inhibition of the β-catenin/LEF-1 pathway. Further research is warranted to comprehensively assess this outcome, which holds promise as a potential targeted treatment for thyroid cancer.

The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine

At recent years, the impairment caused by iodine excess are paid more attention. However, there is still largely unknown about the exact mechanism induced by excessive iodine. MiRNAs have been found to act as biomarkers for a variety of diseases, whereas fewer studies focused on miRNAs related to a cluster of genes regulating thyroid hormone synthesis, such as NIS, Pendrin, TPO, MCT8, TSHR, TSHα, and TSHβ-related miRNAs in structural and functional changes of the thyroid gland induced by subchronic and chronic high iodine exposure. In the present study, one hundred and twenty 4-week-old female Wistar rats were randomly divided into control group (I50µg/L KIO3); HI 1 (I6000µg/L KIO3); HI 2 (I10000µg/L KIO3); and HI 3 (I50000µg/L KIO3), the exposure period was 3 months and 6 months, respectively. The iodine contents in the urine and blood, thyroid function, and pathological changes were determined. In addition, levels of thyroid hormone synthesis genes and the associated miRNAs profiling were detected. The results showed that subclinical hypothyroidism occurred in the high iodine groups with subchronic high iodine exposure, while 6-month exposure led to hypothyroidism in the I10000µg/L and I50000µg/L groups. Subchronic and chronic high iodine exposure caused mRNA and protein levels of NIS, TPO, and TSHR decreased significantly, and Pendrin expression increased significantly. In addition, MCT8 mRNA and protein levels are only remarkably decreased under the subchronic exposure. PCR results showed that levels of miR-200b-3p, miR-185-5p, miR-24-3p, miR-200a-3p, and miR-25-3p increased significantly exposed to high iodine for 3 months, while miR-675-5p, miR-883-5p, and miR-300-3p levels increased significantly under the exposure to high iodine for 6 months. In addition, miR-1839-3p level was markedly decreased exposed to high iodine for 3 and 6 months. Taken together, the miRNA profiling of genes regulating thyroid hormone synthesis remarkably altered from subclinical hypothyroidism to hypothyroidism induced by excess iodine exposure, and some miRNAs may play an important role in subclinical hypothyroidism or hypothyroidism through regulating NIS, Pendrin, TPO, MCT8, and TSHR providing promising targets to alleviate the impairment on the structure and function of thyroid gland.

Role of miR‑181a‑5p in cancer (Review)

MicroRNAs (miRNAs) are non‑coding RNAs (ncRNAs) that can post‑transcriptionally suppress targeted genes. Dysregulated miRNAs are associated with a variety of diseases. MiR‑181a‑5p is a conserved miRNA with the ability to regulate pathological processes, such as angiogenesis, inflammatory response and obesity. Numerous studies have demonstrated that miR‑181a‑5p exerts regulatory influence on cancer development and progression, acting as an oncomiR or tumor inhibitor in various cancer types by impacting multiple hallmarks of tumor. Generally, miR‑181a‑5p binds to target RNA sequences with partial complementarity, resulting in suppression of the targeted genes of miR‑181a‑5p. However, the precise role of miR‑181a‑5p in cancer remains incompletely understood. The present review aims to provide a comprehensive summary of recent research on miR‑181a‑5p, focusing on its involvement in different types of cancer and its potential as a diagnostic and prognostic biomarker, as well as its function in chemoresistance.