• IMMUNE NETWORK
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• v.23 no.5
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• pp.36.1-36.16
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• 2023

Thymic epithelial cells (TECs) play a critical role in thymic development and thymopoiesis. As individuals age, TECs undergo various changes that impact their functions, leading to a reduction in cell numbers and impaired thymic selection. These age-related alterations have been observed in both mice and humans. However, the precise mechanisms underlying age-related TEC dysfunction remain unclear. Furthermore, there is a lack of a comprehensive study that connects mouse and human biological processes in this area. To address this gap, we conducted an extensive transcriptome analysis of young and old TECs in mice, complemented by further analysis of publicly available human TEC single-cell RNA sequencing data. Our analysis revealed alterations in both known and unknown pathways that potentially contribute to age-related TEC dysfunction. Specifically, we observed downregulation of pathways related to cell proliferation, T cell development, metabolism, and cytokine signaling in old age TECs. Conversely, TGF-β, BMP, and Wnt signaling pathways were upregulated, which have been known to be associated with age-related TEC dysfunctions or newly discovered in this study. Importantly, we found that these age-related changes in mouse TECs were consistently present in human TECs as well. This cross-species validation further strengthens the significance of our findings. In conclusion, our comprehensive analysis provides valuable insight into the biological and immunological characteristics of aged TECs in both mice and humans. These findings contribute to a better understanding of thymic involution and age-induced immune dysfunction.

• Clinical and Experimental Pediatrics
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• v.49 no.9
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• pp.996-999
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• 2006

True thymic hyperplasia and ectopic thymus are very rare in children. In embryologic aspect, thymus is distributed around cervical area and ends up in mediastinum. This case is simultaneous thymic hyperplasia of neck and mediastinum. Ectopic thymus in the neck and thymic hyperplasia in the mediastinum in children were reported 2 and 7 cases respectively in Korea. In Clinical aspects, these thymic hyperplasia were presented by mass. So we should suspect these benign condition to avoid unnecessary operation or biopsy. We report a case of true thymic hyperplasia in the mediastinum with ectopic thymus in the neck in a 4-month-old male infant and review the relevant literature. We believe this is the first reported case in the world of true thymus hyperplasia in the mediastinum with cervical ectopic thymus in the neck.

• Molecules and Cells
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• v.38 no.6
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• pp.548-561
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• 2015

By combining conventional single cell analysis with flow cytometry and public database searches with bioinformatics tools, we extended the expression profiling of thymic stromal cotransporter (TSCOT), Slc46A2/Ly110, that was shown to be expressed in bipotent precursor and cortical thymic epithelial cells. Genome scale analysis verified TSCOT expression in thymic tissue- and cell type- specific fashion and is also expressed in some other epithelial tissues including skin and lung. Coexpression profiling with genes, Foxn1 and Hoxa3, revealed the role of TSCOT during the organogenesis. TSCOT expression was detected in all thymic epithelial cells (TECs), but not in the $CD31^+$endothelial cell lineage in fetal thymus. In addition, ABC transporter-dependent side population and Sca-$1^+$ fetal TEC populations both contain TSCOT-expressing cells, indicating TEC stem cells express TSCOT. TSCOT expression was identified as early as in differentiating embryonic stem cells. TSCOT expression is not under the control of Foxn1 since TSCOT is present in the thymic rudiment of nude mice. By searching variations in the expression levels, TSCOT is positively associated with Grhl3 and Irf6. Cytokines such as IL1b, IL22 and IL24 are the potential regulators of the TSCOT expression. Surprisingly, we found TSCOT expression in the lung is diminished in lung cancers, suggesting TSCOT may be involved in the suppression of lung tumor development. Based on these results, a model for TEC differentiation from the stem cells was proposed in context of multiple epithelial organ formation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3457-3460
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• 2014

Background: Thymomas and thymic carcinomas are rare malignancies and devising clinically effective molecular targeted therapies is a major clinical challenge. The aim of the study was to analyze BLC2 and vascular endothelial growth factor receptor (VEGFR) expression and KRAS and EGFR mutational status and to correlate them with the clinical characteristics of patients with thymomas and thymic carcinomas. Materials and Methods: A total of 62 patients (mean age: $50.4{\pm}13.2$ years) with thymomas and thymic carcinomas were enrolled. The expression of BLC2 and VEGFR in tumor cells and normal tissues was evaluated by RT-PCR. The mutational status of the KRAS and EGFR genes was investigated by PCR with sequence specific primers. Results: The BLC2 and VEGFR expression levels did not differ significantly between tumor and normal tissues. Moreover, there were no clearly pathogenic mutations in KRAS or EGFR genes in any tumor. None of the molecular markers were significantly related to clinical outcomes. Conclusions: Changes in levels of expression of BLC2 and VEGFR do not appear to be involved in thymic tumorigenesis. Moreover, our data suggest that KRAS and EGFR mutations do not play a major role in the pathogenesis of thymomas and thymic carcinomas.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.266-273
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• 2002

The dose dependence of the severity of radiation-induced thymic lymphoma in C57BL/6J mice was studied. Mice were exposed to fractionated irradiation at the total doses of 4.0, 6.0 and 8.0 Gy (four irradiations at 8-day intervals) starting from 33 days after birth. Pathological and histological changes of each mouse were observed after periodical sacrifice at day 75, 100, 125, 150, 175, 200, 250, 300 after the first irradiation. The severity of cancers were classified into 4 stages by clinical signs with respect to the enlargement of the thymus, spleen, liver, the progression of the cancer in the thymus, and the metastasis to the spleen, liver, lung and the lymphatic nodes. Among the 490 mice observed, 146 mice had thymic lymphoma. A clear dose-effect relationship was observed as well as the dose-response relationship. Also, periodical observation showed that thymic lymphoma was first induced in mice sacrificed at day 100 (130days old), and metastasize in the order of spleen, lung, liver and then the lymphatic nodes. The results suggest that radiation may be involved not only as a tumor initiator but also as a tumor promoter, and a tumor progression-enhancing agent.

• IMMUNE NETWORK
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• v.9 no.6
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• pp.285-288
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• 2009

The expression pattern of immunoproteasomes in human thymus has not been analyzed but may have important consequences during thymic selection. Here we examined the expression patterns of immunoproteasome subunits in fetal and adult thymic tissues by immunohistochemistry and found that all three subunits are expressed in both cortical and medullary stromal cells. These data suggest that thymic selection in human can be affected by peptide repertoires generated by immunoproteasomes.

• 대한상한금궤의학회지
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• v.4 no.1
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• pp.37-47
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• 2012

Objective : This study is intended to demonstrate the effect of FulingXingrenGancao-Tang on worsened dyspnea after medical treatment for thymic cancer. Method : We diagnosed this case as XiongbiXintongDuanqi(胸痺心痛短氣病) in Jinguiyaolue and treated this patient with FulingXingrenGancao-Tang. Results : By using ZhishiXiebaiGuizhi-Tang, LingGuiWeiGan-Tang, Fuling XingrenGancao-Tang, the patient's symptoms were significantly decreased. Conclusion : This study shows that FulingXingrenGancao-Tang is effective on dyspnea after medical treatment of thymic cancer. However further clinical studies are needed.

• CELLMED
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• v.6 no.3
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• pp.16.1-16.5
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• 2016

Thymic stromal lymphopoietin (TSLP) is a novel interleukin (IL)-7-like cytokine and was originally discovered in the supernatant of a murine thymic stromal cell line. TSLP signal initiates via complex of the TSLP receptor and the IL-7 receptor α chain. TSLP expression is closely connected with many diseases such as atopic dermatitis, allergic rhinitis, asthma, inflammatory arthritis, eosinophilic esophagitis, rheumatoid arthritis, inflammatory bowel diseases, and cancer. In this review, I discussed biological roles of TSLP on mast cell-mediated allergic responses. In addition, this review summarizes the effective drugs in allergic-inflammatory reactions induced by TSLP on mast cells.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.887-890
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• 2001

Neuroendocrine tumor in thymus is rare and has poor prognosis due to frequent recurrence and distant metastasis. Approximately half of thymic carcinoids are hormonally active and Cushing\`s syndrome is seen in 33% of affected patients. Treatment of choice is surgical excision of tumor and role of chemotherapy and radiotherapy is controversal. We report 2 cases of thymic neuroendocrine carcinoma associated with Cushing\`s syndrome.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.212-217
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• 2022

An epidermoid cyst is a benign tumor found anywhere in the body. However, the occurrence of epidermoid cysts in the thymus is extremely rare, with only six cases reported worldwide. The correct diagnosis of thymic epidermoid cysts is often difficult due to the unusual location and nonspecific imaging findings. Herein, we present a case of a thymic epidermoid cyst in a 37-year-old female with clinical information and chest CT findings. Further, we have reviewed previous literature reports describing imaging findings of thymic epidermoid cysts.