Leydig Cell Tumor

The p38 MAPKs play important roles in the regulation of balance between cell survival and cell death on the development of various cancers. However, the roles of p38 MAPKs regulating apoptotic effects on Leydig tumor cells remain unclear. In the present study, we showed that cordycepin (3'-deoxyadenosine) selectively induced apoptosis in MA-10 mouse Leydig tumor cells through regulating the p38 MAPK and PI3K/AKT signaling pathways. Cordycepin reduced viability in MA-10, TM4, and NT2/D1 cells, but not cause cell death of primary mouse Leydig cells on moderate concentration. Cordycepin increased reactive oxygen species (ROS) levels, which is associated with the induction of apoptosis as characterized by positive Annexin V binding, activation of caspase-3, and cleavage of PARP. Inhibition of p38 MAPKs activity by SB203580 significantly prevented cordycepin-induced apoptosis in MA-10 cells. Co-treatment with wortmannin or the autophagy inhibitor 3-methyladenine (3-MA) elevated levels of apoptosis in cordycepin-treated MA-10 cells. Moreover, cordycepin activated p53, p21 and TGFß; and downregulated CDK2. The antitumour activity of cordycepin-treated MA-10 cells was significantly distinct in severe combined immunodeficiency (SCID) mice in vivo. These results suggested that cordycein is a highly selective treatment to induce MA-10 cells apoptosis via p38 MAPKs signaling.

We have previously shown that estrogens binding to estrogen receptor (ER) α increase proliferation of Leydig tumor cells. Estrogens can also bind to G protein-coupled ER (GPER) and activation of this receptor can either increase or decrease cell proliferation of several tumor types. The aim of this study was to investigate GPER expression in R2C rat tumor Leydig cells, evaluate effects of its activation on Leydig tumor cell proliferation and define the molecular mechanisms triggered in response to its activation. R2C cells express GPER and its activation, using the specific ligand G-1, is associated with decreased cell proliferation and initiation of apoptosis. Apoptosis after G-1 treatment was asserted by appearance of DNA condensation and fragmentation, decrease in Bcl-2 and increase in Bax expression, cytochrome c release, caspase and poly (ADP-ribose) polymerase-1 (PARP-1) activation. These effects were dependent on GPER activation because after silencing of the gene, using a specific small interfering RNA, cyt c release, PARP-1 activation and decrease in cell proliferation were abrogated. These events required a rapid, however, sustained extracellular regulated kinase 1/2 activation. G-1 was able to decrease the growth of R2C xenograft tumors in CD1 nude mice while increasing the number of apoptotic cells. In addition, in vivo administration of G-1 to male CD1 mice did not cause any alteration in testicular morphology, while cisplatin, the cytotoxic drug currently used for the therapy of Leydig tumors, severely damaged testicular structure, an event associated with infertility in cisplatin-treated patients. These observations indicate that GPER targeting for the therapy of Leydig cell tumor may represent a good alternative to cisplatin to preserve fertility in Leydig tumor patients.

Tumor antigen-specific cytotoxic T lymphocyte (CTL) is a promising agent for cancer therapy. Most solid tumors are characterized by increased interstitial fluid pressure (IFP) and dense collagen capsule, which form physical barriers to impede cancer treatment. However, it remains unclear how CTL-mediated anticancer response is affected at the presence of these obstacles. Using a microfluidic-based platform mimicking these obstacles, we investigated the migration characteristics and performance of anticancer response of CTLs targeting hepatic cancer cells via antigen-specific and allogeneic recognition. The device consisted of slit channels mimicking the narrow interstitial paths constrained by the fibrous capsule and increased IFP was simulated by applying hydrostatic pressure to the tumor center. We found that antigen-specificity of CTLs against the targeted cancer cells determined the cytotoxic efficacy of the CTLs but did not significantly affect the success rate in CTLs that attempted to infiltrate into the tumor center. When increased IFP was present in the tumor center, CTL recruitment to tumor peripheries was promoted but success of infiltration was hindered. Our results highlight the importance of incorporating the physical characteristics of tumor interstitum into the development of CTL-based cancer immunotherapy.

Approximately 10% of testicular Leydig cell tumors (LCTs) are clinically malignant and unresponsive to systemic treatment. Predicting their clinical behavior can be problematic because there are no biomarkers that can consistently discriminate between benign and malignant LCTs. We assessed microRNA expression profiles of LCTs to identify differentially expressed microRNAs that could potentially distinguish benign from malignant neoplasms. The study consisted of two phases. In the first (discovery) phase, we interrogated 768 microRNAs in a series of 11 LCTs (six malignant and five benign) using Taqman Low-Density Array (TLDA) microRNA profiling. In the second phase, we validated the top differentially expressed microRNA targets with real-time quantitative PCR on a series of 35 LCTs (17 malignant and 18 benign), assessing their clinical performance for distinguishing malignant from benign LCTs. Target biologic pathways were analyzed using the miRTargetLink 2.0 tool. A total of 50 microRNAs were differentially regulated in malignant LCTs (27 upregulated, 23 downregulated). The top six microRNA candidates (top three upregulated and top three downregulated) were validated, showing good performance for discriminating between malignant and benign LCTs, with an area under the curve (AUC) ranging between 0.69 and 0.87. MiR-196b-5p showed the best performance, with sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 82%, 83%, 83%, 82%, and 83%, respectively. A panel (i.e. combined) analysis reached 100% sensitivity and 83% specificity. Pathway analysis revealed significant overlap in the biological process targeted by the upregulated microRNAs in malignant LCTs, including proliferation, development, metabolism, hormone synthesis, and cell death. Our results support the idea that malignant LCTs are associated with a distinct microRNA signature. MiR-196b-5p was identified as a potentially useful biomarker to distinguish benign from malignant tumors. The shared downstream targets of the top upregulated microRNAs suggest that dysregulation of cell proliferation and apoptosis underlie aggressive biologic behavior in LCTs and may offer opportunities for targeted therapies. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.