TAF participated in the progression of various cancers, including PA via the release of soluble factors. Exosomes belonged to extracellular vesicles, which were revealed as a crucial participator in intercellular communication. However, the expression pattern and effect of TAF-derived exosomes remained largely unknown in PA. In the present study, we performed in silico analysis based on public RNA-seq datasets to generate the circRNA/miRNA regulatory network. The qRT-PCR, Western blotting, RNA pull-down, and luciferase assay were performed to investigate the effect of TAF-derived exosomes. TAF-derived exosomal circDennd1b was significantly upregulated in PA and promoted the proliferation, migration, and invasion of PA cells via sponging miR-145-5p in PA cells. In addition, miR-145-5p directly regulated One Cut homeobox 2 (ONECUT2/OC2) expression and inhibited the promoting effect of ONECUT2 on PA. We further demonstrated that ONECUT2 transcriptionally increased fibroblast growth factor receptor 3 (FGFR3) expression, which further activates the mitogen-activated protein kinases (MAPK) pathway, thus promoting PA progression. Moreover, the suppression of TAFs by ABT-263 and ONECUT2 by CSRM617 inhibited the growth of PA. In conclusion, our study illustrated that TAF-derived exosomal circDennd1b affected PA progression via regulating ONECUT2 expression, which provides a potential therapeutic strategy against aggressive PA.

Background: Pituitary adenoma (PA) bone invasion results in adverse outcomes, such as reduced rates of complete surgical resection and biochemical remission as well as increased recurrence rates, though few studies have been conducted. Methods: We collected clinical specimens of PAs for staining and statistical analysis. Evaluation of the ability of PA cells to induce monocyte–osteoclast differentiation by coculturing PA cells with RAW264.7 in vitro. An in vivo model of bone invasion was used to simulate the process of bone erosion and evaluate the effect of different interventions in alleviating bone invasion. Results: We found an overactivation of osteoclasts in bone-invasive PAs and concomitant aggregation of inflammatory factors. Furthermore, activation of PKCθ in PAs was established as a central signaling promoting PA bone invasion through the PKCθ/NF-κB/IL-1β pathway. By inhibiting PKCθ and blocking IL1β, we were able to significantly reverse bone invasion in an in vivo study. Meanwhile, we also found that celastrol, as a natural product, can obviously reduce the secretion of IL-1β as well as alleviate the progression of bone invasion. Conclusions: By activating the PKCθ/NF-κB/IL-1β pathway, pituitary tumors are able to induce monocyte–osteoclast differentiation in a paracrine manner and promote bone invasion, which can be alleviated by celastrol.

Aims: Dopamine agonists (DAs) are the first-line treatment for patients with prolactin-secreting pituitary adenoma (PRL adenoma). However, a subset of individuals exhibits poor responses, known as DA resistance. Previous studies have reported that DA resistance is more prevalent in male patients. This study aims to investigate the relationship between androgen receptor (AR) expression and DA resistance, as well as to explore underlying mechanisms of AR-mediated DA resistance. Results: Our results demonstrated that patients with higher AR expression exhibit greater resistance to DA in our cohort of DA-resistant PRL adenoma. Furthermore, AR was found to be involved in cell proliferation, PRL secretion, and resistance to bromocriptine (BRC) both in vitro and in vivo . Mechanistically, we demonstrated that intracellular reactive oxygen species (ROS) function as upstream mediators of apoptosis and ferroptosis following BRC treatment. As a ligand-dependent transcription factor, AR could translocate to the nucleus and transcriptionally promote NFE2-like bZIP transcription factor 2 (NRF2) expression, which regulates intracellular ROS levels, thereby enhancing cell viability and conferring DA resistance to pituitary adenoma (PA) cells. Finally, AR targeting agents were used to inhibit AR signaling, downregulate NRF2 transcription, and sensitize PA cells to BRC treatment. Conclusion and Innovation: We demonstrated that AR plays a crucial role in mediating DA resistance in PRL adenoma. Mechanistically, AR promotes cell proliferation and PRL secretion and confers drug resistance by transcriptionally regulating NRF2 expression to maintain redox homeostasis in PA cells. Finally, combining AR targeting agents with BRC shows promise as a therapeutic strategy for treating PRL adenomas. Antioxid. Redox Signal. 42, 954–972.

Prolactinomas are commonly treated with dopamine receptor agonists (DAs), such as bromocriptine (BRC) and cabergoline (CAB). However, 10–30% of patients exhibit resistance to DA therapies. DA resistance is largely associated with reduced dopamine D2 receptor (DRD2) expression, potentially regulated by epigenetic modifications, though the underlying mechanisms are still unclear. Clinical samples were assessed for p300 expression. MMQ and AtT-20 cells were engineered to overexpress either wild-type p300 or a histone acetyltransferase (HAT) domain-mutant form of p300. Mechanistic studies included cell proliferation assays, flow cytometry, immunohistochemistry, immunofluorescence, co-immunoprecipitation, chromatin immunoprecipitation followed by quantitative PCR, reverse transcription quantitative PCR, and Western blotting. Additionally, an in vivo nude mouse xenograft model was used to confirm the in vitro findings. DAs downregulated p300 through the cAMP-PKA-CREB pathway. Activation of the HAT domain of p300 increased H3K18/27 acetylation, promoted DRD2 transcription, and worked synergistically with DA to exert anti-tumor effects both in vitro and in vivo. Tanshinone IIA (Tan IIA) upregulated p300 and DRD2, enhancing the therapeutic efficacy of BRC. These findings highlight the role of p300 in regulating DRD2 transcription in DA-resistant prolactinomas. Combining Tan IIA with BRC may offer a promising strategy to overcome DA resistance.

Background: Glioblastoma (GBM) exhibits marked cellular heterogeneity and resistance to therapy. Calcium (Ca²⁺) signaling at endoplasmic reticulum (ER)–mitochondria contact sites has emerged as a key regulator of mitochondrial function and cell fate; however, its lineage-specific role and therapeutic relevance in GBM remain unclear. Methods: ITPR1 expression was analyzed using single-cell and bulk RNA sequencing (RNA-seq) datasets and validated by immunohistochemistry and survival analyses. Functional studies were conducted using genetic silencing or CRISPR-mediated activation of ITPR1, combined with DRP1 knockdown, Ca²⁺ imaging, transmission electron microscopy, co-immunoprecipitation, mitochondrial fractionation, and mitochondrial functional assays. Therapeutic efficacy was evaluated in orthotopic GBM xenograft models treated with 2-aminoethoxydiphenyl borate (2-APB), temozolomide (TMZ), or their combination. Results: ITPR1 was enriched in mesenchymal-like malignant cell states and associated with higher tumor grade, recurrence, and poor prognosis. ITPR1 knockdown suppressed GBM cell proliferation and tumor growth while promoting intrinsic apoptosis. Mechanistically, loss of ITPR1 impaired ER-to-mitochondria Ca²⁺ transfer, disrupted ER–mitochondria contacts, and altered mitochondrial ultrastructure. This was accompanied by reduced DRP1 Ser616 phosphorylation and mitochondrial recruitment, as well as decreased autophagy and mitophagy activity. Consequently, ITPR1 knockdown led to mitochondrial depolarization, increased mitochondrial reactive oxygen species (ROS) accumulation, and activation of mitochondria-dependent apoptosis. Conversely, DRP1 knockdown attenuated the mitochondrial and pro-survival effects induced by ITPR1 overexpression. In vivo, combined treatment with 2-APB and TMZ resulted in greater tumor suppression and prolonged survival compared with either treatment alone, accompanied by increased apoptosis and reduced proliferation in tumor tissues. Conclusions: ITPR1 promotes GBM progression by sustaining ER–mitochondria Ca²⁺ coupling and DRP1-dependent mitochondrial quality control, thereby maintaining mitochondrial homeostasis and cell survival. Targeting inositol 1,4,5-trisphosphate receptor (IP₃R)-mediated Ca²⁺ signaling with 2-APB enhances the therapeutic efficacy of TMZ, suggesting that ITPR1-centered Ca²⁺ signaling may represent a potential therapeutic vulnerability in aggressive GBM.

Pituitary apoplexy is an uncommon but clinically urgent complication that often involves intrasellar hemorrhage and tissue necrosis. The mechanisms linking acute tissue injury to the inflammatory tumor microenvironment remain incompletely defined. Here, we characterized the apoplexy-associated microenvironment and examined whether macrophage mechanosensitive signaling contributes to inflammatory amplification and tissue damage in pituitary neuroendocrine tumors (PitNETs). We combined single-cell RNA sequencing (scRNA-seq), histological validation, clinical stratification, and in vitro functional assays using apoplectic and non-apoplectic human PitNET specimens. Macrophage state transitions, intercellular communication, and transcriptional regulatory programs were analyzed, followed by an experimental assessment of the PIEZO1–Ca²⁺ axis and macrophage-conditioned medium-induced tumor cell death. Histological validation confirmed macrophage accumulation in apoplectic PitNETs, including a 1.67-fold increase in IBA-1-positive cells (p < 0.001). CellChat-inferred interaction metrics increased descriptively in apoplectic samples. Apoplectic tissues showed higher TNF-α expression (3.00-fold; p < 0.0001) and higher PIEZO1 fluorescence in IBA-1-positive regions (1.39-fold; p = 0.001). Yoda1 increased Calcium 520 fluorescence in macrophages (1.72-fold; p = 0.002), whereas Piezo1 knockdown reduced the Yoda1-associated response (p = 0.003). Conditioned medium from activated macrophages increased total Annexin V/PI-positive death in AtT-20 cells (0.53 ± 0.53% to 32.48 ± 1.14%; p < 0.001) and GH3 cells (0.82 ± 0.50% to 30.92 ± 1.11%; p < 0.001); Piezo1 knockdown or TNF-α neutralization attenuated this effect. Clinically, pathological necrosis was associated with higher symptom frequencies and a greater adjusted likelihood of two or more clinical symptoms. Together, these findings indicate that PIEZO1-related macrophage signaling may participate in TNF-α-associated tumor cell necroptosis in pituitary apoplexy. Pathological necrosis was linked to greater acute symptom burden and perioperative hormonal abnormalities, suggesting that it may identify a clinically severe apoplexy subtype.