Myoepithelioma is a rare benign salivary gland tumor, accounting for <1% of all salivary gland neoplasms, with only a little over ten cases of nasal cavity or paranasal sinus involvement reported in the English literature. Due to its rarity, lack of specific imaging features, and significant histological overlap with other tumors, the diagnosis poses a challenge for clinicians, radiologists, and pathologists. We present a case of a 68-year-old male with progressively worsening nasal obstruction over 6 months, ultimately diagnosed with nasal myoepithelioma. Approximately 3 months after endoscopic transnasal tumor resection, the patient showed no signs of recurrence. Low cytological atypia, a low Ki-67 proliferation index, and characteristic immunohistochemical findings support the diagnosis of benign myoepithelioma. This case suggests that myoepithelioma should be considered in the differential diagnosis when benign-appearing tumors are observed in the nasal cavity or paranasal sinuses. A multidisciplinary approach integrating imaging, histopathology, and immunohistochemistry is essential for establishing an accurate diagnosis.
Objectives: B-Raf proto-oncogene ( BRAF) and telomerase reverse transcriptase ( TERT) mutations have established roles in the management of thyroid nodules, but rat sarcoma virus oncogene homolog ( RAS) mutations’ significance is less conclusive. Integrating mutation profiles with cytological grades provides evidence to evaluate the clinical significance of molecular testing in risk stratification and diagnosis of thyroid nodules. Material and Methods: A total of 5378 nodules were subjected to fine-needle aspiration (FNA cohort) and classified according to the Bethesda system for reporting thyroid cytology. Of them, 705 were surgically removed (thyroidectomy cohort) and pathologically examined, and 53 were followed for 0.5–53.6 months (follow-up cohort) and underwent at least one follow-up FNA. Eight follow-up nodules were resected. All FNA samples were tested for mutations of the BRAF V600E , TERT , and RAS genes. Results: 640 nodules of the thyroidectomy cohort and 6 follow-up nodules were malignant. Molecular testing showed BRAF V600E had a prevalence of 41.5, 58.0, and 15.1% in FNA-, thyroidectomy-, and follow-up cohorts, respectively, but RAS mutations’ prevalence was no higher than 4% in any of them, while TERT mutations’ prevalence was <1%. Consistently, BRAF V600E had a sensitivity of 63.9% and a specificity of 100% in diagnosing malignancy in the thyroidectomy cohort, while RAS mutations had much lower sensitivity and specificity (1.88 and 7.65%, respectively). Furthermore, BRAF V600E increased the risk of malignancy of the FNA cohort to 100% regardless of cytological grades, while RAS mutations showed no increase. In the follow-up nodules, BRAF V600E was strongly associated with malignancy and elevated cytological grades, while RAS mutations showed no association. Conclusion: BRAF V600E is a robust marker for thyroid malignancy in FNA specimens, whereas RAS mutations have limited standalone diagnostic utility but may still provide adjunctive value for risk stratification when interpreted together with cytology and clinical findings.
Immune checkpoint inhibitor (ICI)-associated acute kidney injury is a significant complication of cancer immunotherapy, with acute interstitial nephritis (AIN) being the most common pathological type. This review systematically elaborates on the core pathogenesis, spectrum of pathological heterogeneity, and the distinct immunological underpinnings of ICI-associated AIN (ICI-AIN). The typical mechanism of ICI-AIN involves abnormal activation of the adaptive immune system, activating resident autoreactive CD8 + tissue-resident memory T cells. This triggers an interferon-gamma-driven inflammatory cascade, which subsequently recruits and activates myeloid cells, establishing a self-amplifying immune injury network. This type of mechanism can sometimes also form a tertiary lymphoid structure. Further research has unveiled a highly heterogeneous immunopathological spectrum of ICI-AIN, encompassing distinct subtypes often accompanied by features such as a dominant neutrophil infiltration and granulomatous interstitial nephritis. These subtypes correspond to differential immunopathogenic pathways and are closely associated with responses to glucocorticoid therapy and long-term renal outcomes. Future directions necessitate the integration of spatial multi-omics technologies and clinical studies to deeply dissect the immune cell interaction networks. Such efforts are critical to advancing the development of non-invasive diagnostics and targeted therapies, ultimately enabling precision clinical management of ICI-AIN.
Objectives: Cytopathology laboratories are required to track diagnostic category distributions as part of quality control (QC) under Clinical Laboratory Improvement Amendments regulations. This process is typically manual, time-consuming, and prone to inconsistency. We evaluated whether a large language model (LLM) could accurately and efficiently categorize cytopathology reports to support regulatory QC processes. Material and Methods: A total of 472 fine needle aspiration and non-gynecologic (NG) cytology reports from 1–31 January 2024 were processed using DeepSeek-R1:32B, a locally deployed open-source LLM. GYN cytology reports were excluded because their diagnostic categories are already captured as discrete data in our laboratory information system, eliminating the need for natural language processing. The model extracted the final diagnosis, diagnostic category, and confidence score from each report. A board-certified cytopathologist independently reviewed all cases to serve as the ground truth. Cases were categorized as correct or incorrect. Time required for manual versus artificial intelligence (AI)-assisted review was also measured. Results: The model achieved 98.5% categorization agreement (95% confidence interval: 97.0–99.3%; Cohen’s Kappa = 0.973) with expert review (465/472 cases were classified as correct), with only 1.5% (7/472) raw misclassifications. Most misclassifications were due to semantic ambiguity, missing context, or institutional interpretation conventions. The pipeline implemented a human-in-the-loop mechanism by flagging low-confidence or non-standard outputs for manual review, enhancing safety. The AI-assisted workflow reduced total review time by 98.5%, from 279 to 4.15 min. Conclusion: This study demonstrates that LLMs can accurately and safely support cytopathology QC tasks, significantly reducing workload while maintaining reporting consistency. With further development and validation, LLM-powered tools may become integral to pathology workflows across specialties.
Objective:While carboplatin remains a cornerstone chemotherapeutic agent for ovarian carcinoma, the emergence of resistance constitutes a major contributor to therapeutic failure and compromised clinical outcomes. This study elucidates molecular mechanisms driving carboplatin resistance and identifies novel therapeutic targets for carboplatin-refractory malignancies through characterization of a long non-coding RNA (lncRNA)-encoded micropeptide. Material and Methods:Ribosome profiling analysis delineated translational alterations induced by carboplatin in ovarian cancer models. Mechanistic validation was achieved through the integration of gain- and loss-of-function methodologies, nuclear localization assays, and quantitative assessment of deoxyribonucleic acid (DNA) damage through enumeration of gamma-H2AX (phosphorylated histone H2AX at serine 139) foci, supplemented by alkaline comet analysis. The therapeutic significance was corroborated using subcutaneous xenograft models derived from patient-derived ovarian cancer cells. Results:The micropeptide carboplatin-induced upregulation factor (CARUF), derived from lncRNA LOC101926915, was markedly upregulated in response to carboplatin treatment, with ribosome profiling showing significant enrichment of ribosome-associated LOC101926915 transcripts (adjusted P < 0.01 and log2FC >1). In clinical specimens, elevated CARUF expression was positively correlated with platinum resistance (r = 0.425, P < 0.001). Functional analyses showed that CARUF overexpression promoted DNA damage repair (P < 0.001) and enhanced carboplatin resistance both in vitro and in vivo (P < 0.001). In contrast, CARUF inhibition impaired DNA damage repair (P < 0.001) and restored carboplatin sensitivity (P < 0.001), resulting in reduced cell viability in vitro (P < 0.001) and suppressed tumor growth in vivo (P < 0.001). Mechanistically, carboplatin-induced DNA lesions activated ataxia-telangiectasia mutated and Rad3-related (ATR) kinase, which phosphorylated CARUF, facilitated its localization to DNA lesion sites, and enhanced DNA repair capacity. Conclusion:Our findings identify CARUF as a critical mediator of aberrant DNA damage response signaling in carboplatin-resistant ovarian cancer, indicating its potential as a druggable target for overcoming carboplatin resistance.
Objectives:This retrospective, single-center, small-sample proof-of-concept study aims to evaluate the feasibility of detecting epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in the supernatant of non-plasma biological fluids, pleural, ascitic, or pericardial effusions, using the Idylla® platform (Ct cartridges with research use only certification for plasma samples). Materials and Methods:Ten fluids were tested with the Ct KRAS cartridge and seven with the Ct EGFR cartridge, comparing results with Idylla® testing in formalin fixed paraffin embedded (FFPE) tissue from the primary tumor. For each sample, 100 μL of supernatant was directly pipetted into the corresponding cartridge; in turbid samples, a preliminary centrifugation step (1600 g, 10 min, room temperature) was performed. Results:All cases showed concordance between fluid and FFPE results. Notably, KRAS mutations were detected in two fluids with no malignant cells and in one with only scattered tumor cells, and an EGFR mutation was detected in a sample with 5% tumor cells. Specimens had been stored at 4°C for up to 3 weeks, suggesting good DNA preservation. Conclusion:This simple and rapid approach appears feasible in low tumor cellularity samples and could expand molecular testing to patients without accessible tissue. Validation in larger, multicenter cohorts is warranted.
Objective: In type 1 autoimmune pancreatitis (AIP), serum immunoglobulin G4 (IgG4) has a complex correlation with pathology. In this study, clinical/histopathological traits of serum IgG4-negative/positive (N/P) patients were compared, and serum IgG4-tissue IgG4 correlations were explored to aid accurate diagnosis/typing. Material and Methods: A retrospective analysis was performed on 78 type 1 AIP patients (screened from 160 eligible cases through inclusion/exclusion criteria, International Consensus Diagnostic Criteria-confirmed at Changhai Hospital (December 2019-2023). At diagnosis, patients with serum IgG4 <135 mg/dL (n = 19) were assigned to the serum IgG4-N group, and those with serum IgG4 ≥135 mg/dL (n = 59) were assigned to the serum IgG4-P group. Clinical baseline data, laboratory indicators, imaging features (computed tomography/magnetic resonance imaging/endoscopic ultrasound guided [EUS]), and histopathological findings (from EUS fine-needle aspiration/fine-needle biopsy [EUS-FNA/FNB] or surgery) were compared. Statistical analysis (R 4.4.0) was conducted with Chi-square/Fisher’s exact tests (categorical data) and Mann‒Whitney U tests (continuous data); Spearman correlation was used to assess serum IgG4-tissue IgG4 links. A Bonferroni-corrected P <0.050 was considered to indicate statistical significance. Results: No significant differences in sex, age, most comorbidities (e.g., hypertension), or symptoms (e.g., abdominal discomfort) were observed between the serum IgG4-N and serum IgG4-P groups (all P > 0.050). The rate of bile duct stenosis was higher in the serum IgG4-P group than in the serum IgG4-N group (55.93% vs. 26.32%, P = 0.047), as were the rates of EUS examination (84.75% vs. 52.63%, P = 0.010), EUS-FNA/FNB (84.75% vs. 52.63%, P = 0.010). The 84.75% vs 52.63% ( P = 0.010) represents the EUS examination receiving rate between serum IgG4-P and serum IgG4-N groups, rather than the diagnostic positive rate of FNA/FNB subtypes. The serum IgG4-P group also had a higher histopathological confirmation rate (71.19% vs. 36.84%, P = 0.015) and a greater median number of tissue IgG4-P cells (36 vs. 8 cells per high-power field (HPF), P = 0.035). In contrast, the serum IgG4-N group had a higher median carbohydrate antigen 19-9 (CA19-9) level (32.14 vs. 5.97 U/mL, P = 0.035), a higher rate of long/multiple pancreatic duct narrow sections (30% vs. 2%, P = 0.013), and a higher surgical rate (47.37% vs. 15.25%, P = 0.010). Across both groups, no significant correlation was detected between serum IgG4 levels and tissue IgG4-P plasma cell counts (Spearman’s rho = 0.113, P = 0.322; linear regression coefficient = 0.004, P = 0.538). Conclusion: Serum IgG4 typing is associated with the clinical-pathological features of type 1 AIP. The serum IgG4-P group often shows biliary duct stenosis and diffuse pancreatic enlargement, with a reliance on EUS puncture. The serum IgG4-N group has higher CA19-9 and a higher surgical rate. Pathological examination remains critical (no serum-tissue IgG4 association). This study supports optimized, accurate diagnosis and stratified management of type 1 AIP.
Objectives: Parkinson’s disease (PD), the second most prevalent neurodegenerative disease, is closely linked to aging and immune system dysfunction. This study aims to explore potential aging-related biomarkers of PD and examine their diagnostic value, in addition to their relationship with immune cell infiltration, to identify novel therapeutic targets. Methods: Gene expression profiles from the gene expression omnibus (GEO) database (GSE20163, GSE20164, and GSE8397) were analyzed. Aging-related genes associated with PD were screened using weighted gene co-expression network analysis. Subsequent functional enrichment analysis, protein‒protein interaction (PPI) network mapping, and least absolute shrinkage and selection operator regression were used to identify key biomarker candidates. A receiver operating characteristic (ROC) curve analysis was applied to evaluate diagnostic efficacy. Immune cell infiltration was assessed through Spearman correlation analysis, and the expression of key biomarkers was validated in both cellular and animal PD models. Results: Eighteen aging-related genes were identified through a PPI network analysis. Seven genes, including forkhead box O3 (FOXO3) and the proto-oncogene tyrosine-protein kinase receptor rearranged during transfection (RET), showed potential as diagnostic biomarkers for PD. Gene set enrichment analysis revealed that these biomarkers correlated with immune cell infiltration patterns in PD patients. The ROC curve analysis indicated high diagnostic accuracy for these genes across multiple datasets (area under the curve = 96.3158). In vivo and in vitro validation confirmed significant changes in the expression of RET and FOXO3 in PD samples, highlighting their relevance as biomarkers. Conclusion: Our findings suggest that RET and FOXO3 are promising aging-related biomarkers for PD, potentially providing new insights into the early diagnosis and targeted treatment of PD. These biomarkers also reflect the complex interplay between aging, immunity, and PD pathogenesis.
Objective: This study analyzes a rare myxoid spindle cell lipoma (SCL) around the ileum. It aims to systematically summarize the clinicopathological features of this tumor at an atypical location. This will improve understanding of this rare condition. Material and Methods: We conducted a detailed study of SCL around the ileum. This mass was incidentally found in a right hemicolectomy specimen. The analysis integrated multiple methods. These included histomorphological observation, immunohistochemical staining, and molecular testing. Results: The tumor showed a typical myxoid stromal background. It contained spindle cells and scattered mature adipocytes. The characteristic thick collagen bundles commonly seen in classic SCL were absent. A diagnosis of myxoid SCL was confirmed based on the following features: CD34-positive spindle cells, loss of retinoblastoma protein 1expression, a low Ki-67 index, and the absence of MDM2 amplification by both IHC and fluorescence in situ hybridization. This profile effectively excludes malignant differential diagnoses, such as liposarcoma. Conclusion: Myxoid SCL around the ileum is extremely rare. Its diagnosis relies on recognizing its characteristic morphological spectrum. Immunohistochemistry and molecular testing are essential to exclude malignant tumors. A comprehensive understanding of its unique presentation at atypical sites is crucial. This is important for achieving accurate diagnosis and preventing inappropriate treatment.
CD30 positivity serves as a critical diagnostic hallmark for anaplastic lymphoma kinase positive anaplastic large cell lymphoma (ALK+ ALCL); however, rare cases with partial or complete loss of CD30 expression present diagnostic challenges. We report a unique case with two morphologically and immunophenotypically distinct subpopulations within the same tumor: A typical CD30-positive component and a CD30-negative counterpart. Comparative genetic analysis revealed overlapping but divergent molecular features, including nucleophosmin 1- ALK ( NPM1-ALK ) fusion, notch receptor 1 mutations, and differential gene amplifications involving MYC proto-oncogene and BCL2-like 1. These findings offer insights into the regulatory mechanisms of CD30 and highlight that loss of CD30 expression alone should not preclude the diagnosis of ALK-positive ALCL, underscoring the importance of integrated histopathological and molecular evaluation in diagnostically challenging cases. Meanwhile, it provides a basis for optimizing the diagnostic process of clinically suspected cases.
Objectives: Myocardial infarction (MI) is linked to high mortality, which highlights the need for early diagnosis and intervention to prevent heart failure. N6-methyladenosine (m6A) methylation of ribonucleic acid (RNA) influences endothelial dysfunction and MI. Here, the effects and associated mechanisms of fat mass and obesity-associated gene (FTO) on vascular endothelial cell (EC) function, as well as myocardial damage in mice following MI were investigated. Material and Methods: A human umbilical vein EC (HUVEC) model of oxygen-glucose deprivation (OGD) as well as a mouse MI model were used to detect MI-induced endothelial and myocardial damage. EC function was examined using cell-counting-kit-8, wound healing, migration, and tube formation assays. Methylated RNA immunoprecipitation (MeRIP) sequencing and RNA sequencing were utilized to analyze the m6A modifications and RNA expression patterns in control and FTO-overexpressing ECs following OGD. FTO and ATP-binding cassette subfamily F member 1 (ABCF1) levels were evaluated using western blotting. The relationship between FTO and ABCF1 was determined using RNA immunoprecipitation-quantitative polymerase chain reaction (RIPqPCR), MeRIP-qPCR, and RNA stability assays. Echocardiography and Masson's trichrome and hematoxylineosin staining were used to measure myocardial injury. Results: FTO expression was reduced in infarcted myocardial tissue and OGD-induced HUVECs (P < 0.01). Functionally, FTO overexpression improved the impaired function of OGD-treated HUVECs and restored myocardial function in MI mice (P < 0.01). Mechanistically, FTO reduced m6A methylation of ABCF1 mRNA and raised ABCF1 levels in OGD-treated HUVECs (P < 0.01). Conclusion: Taken together, our study revealed that FTO overexpression restored OGD-induced endothelial dysfunction and myocardial pathological injury after MI. FTO increased ABCF1 expression in OGD-treated HUVECs through an m6A-dependent mechanism. These findings offer new insights into mitigating EC dysfunction and myocardial injury after MI.
Objective:The current non-invasive screening methods for endometrial cancer (EC), such as transvaginal ultrasound (TVUS), lack sufficient specificity, leading to unnecessary invasive diagnostic procedures. The detection of cancer-specific deoxyribonucleic acid (DNA) methylation alterations in cervical cytology samples presents a promising, minimally invasive alternative. This study aimed to evaluate the diagnostic potential of novel DNA methylation biomarkers (CUGBP Elav-like family member 4 methylation [CELF4m ], Galanin receptor 1 methylation [GALR1m ], Zinc finger protein 486 methylation [ZNF486m ]) in cervical exfoliated cells for EC screening. Material and Methods:This case-control study enrolled patients scheduled for diagnostic or surgical curettage at the hospital from September 2024 to June 2025. A total of 104 women underwent endometrial evaluation (32 type I EC, 3 type II EC, 61 benign lesions [BL], 8 atypical hyperplasia). Quantitative methylation-specific polymerase chain reaction assessed biomarker performance against histopathological diagnosis. Results:All three markers (CELF4m, GALR1m, ZNF486m ) showed significant differential ΔCp values between BL and EC groups (all P < 0.01), with moderate diagnostic accuracy (area under the ROC curve [AUCs]: 0.654-0.704). The single-marker GALR1m outperformed endometrial thickness (ET) measured by TVUS in specificity (60.9% vs. 27.5%, P < 0.001) while maintaining comparable sensitivity (80.0% vs. 74.3%, P = 0.527). A two-marker panel (GALR1m /ZNF486m , Model 1) achieved sensitivity (97.1% [95% confidence interval [CI]: 91.6-100%]) with modest specificity (49.3% [95% CI: 37.5-61.1%]). Among three-gene models, Model 3 demonstrated the highest overall performance (AUC: 0.733 [95% CI: 0.657-0.808]; sensitivity: 91.4% [95% CI: 82.1-100%]), whereas Model 4 balanced sensitivity (80.0% [95% CI: 66.7-93.3%]) and improved specificity (63.8% [95% CI: 52.4-75.1%]). Conclusion:DNA methylation signatures in cervical cells show superior diagnostic accuracy to conventional ET measured by TVUS, particularly through multi-marker panels. This non-invasive approach represents a promising EC screening strategy.
Objectives: This study aimed to analyze the prevalence, genotype distribution, and infection burden of human papillomavirus (HPV) as well as their association with cytological findings, among 7,601 women attending a tertiary referral center in Athens, Greece. Materials and Methods: This retrospective, single-center cross-sectional study analyzed cervical samples from women attending a specific institution (2019-2024) that underwent polymerase chain reaction-based HPV genotyping, while cytological findings were classified according to the Bethesda system. Statistical analyses assessed the relationships between HPV types, infection burden, cytological outcomes, and age groups. Results: Overall HPV prevalence was 31%, including 18.4% single and 12.6% multiple infections. The most frequent HPV genotypes detected were HPV-42, HPV-51, HPV-16, HPV-53, and HPV-54. Multiple infections were more common in younger women, while single infections predominated with increasing age. Cytological results showed 82.3% normal, 15.9% low-grade squamous intraepithelial lesions (LSILs), 1.3% atypical squamous cells of undetermined significance (ASC-US), and 0.5% high-grade squamous intraepithelial lesions (HSILs). HPV types 16, 18, 31, 33, 42, and 51 were strongly associated with LSIL and/or HSIL. Women with multiple HPV infections had higher odds of ASC-US and LSIL compared to those with single infections; however, the opposite pattern was observed for HSIL. Age was inversely associated with ASC-US and LSIL but not with HSIL. Conclusion: These findings highlight the importance of HPV genotype and infection burden in cervical disease risk in this patient cohort and underscore the need for targeted screening and vaccination strategies tailored to the local epidemiology.
Objective: Colorectal cancer (CRC) is a malignancy known for its aggressive behavior and notable mortality burden. Indoleamine 2,3-dioxygenase 1 (IDO1), an immune checkpoint molecule, is markedly upregulated in CRC, and it has been implicated in the regulation of key components of the ferroptosis pathway. This study aimed to elucidate the regulatory interaction between IDO1 and ferroptosis and assess the potential therapeutic effect of combined IDO1 inhibition with ferroptosis inducers Erastin and RSL3 in CRC. Material and Methods: Three CRC cell lines (CT26, MC38, and HT-29) and one normal colon epithelial cell line (NCM460) were treated with ferroptosis inducers to evaluate the changes in IDO1 expression through reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting. MC38 cells with stable IDO1 knockdown were generated through lentiviral transduction. The expressions of ferroptosis-related genes following IDO1 silencing were assessed through RT-qPCR and Western blot. The antitumor efficacy of combined IDO1 knockdown and Erastin/RSL3 treatment was evaluated through cell counting kit-8, Transwell migration, and wound-healing assays. Enzyme-linked immunosorbent assay was employed to quantify intracellular levels of glutathione (GSH) and malondialdehyde (MDA). Reactive oxygen species (ROS) levels were measured via flow cytometry, and ferrous ion (Fe2+)and nicotinamide adenine dinucleotide phosphate (NADPH) concentrations were determined through colorimetric analysis. Results: Treatment with Erastin and RSL3 upregulated IDO1 expression in CRC cells. Silencing of IDO1 in MC38 cells resulted in increased expressions of cyclooxygenase-2, acyl-CoA synthetase long chain family member 4, and NADPH oxidase 1, alongside decreased expression of GSH peroxidase 4, solute carrier family 7 member 11, ferritin heavy chain 1, and nuclear factor E2-related factor 2. The combination of IDO1 knockdown with Erastin/RSL3 treatment significantly reduced the proliferation, invasion, and migration of MC38 cells (P < 0.001). This combined treatment also elevated intracellular MDA, ROS, and Fe2+ levels while lowering GSH and NADPH levels. Conclusion: Combination therapy with IDO1 inhibitor and ferroptosis inducer may be an effective way to improve treatment efficacy in CRC.
Objective: Breast cancer (BC) is one of the most common malignant tumors among women. Gamma-aminobutyric acid (GABA) is abnormally expressed in various cancers, but its effect on BC remains unclear. This study aims to explore the expression changes of glutamic acid decarboxylase 1 (GAD1) in BC and its mechanism of promoting tumor occurrence and development by regulating GABA synthesis. Material and Methods: GAD1 expression and GABA levels in BC cells (MDA-MB-231) and normal breast epithelial cells (MCF-10A) were measured. GAD1 overexpression and knockdown cell lines were constructed to evaluate the changes in GABA levels and their effects on cell proliferation and invasion ability. Macrophage M2 polarization and protumor factor levels were analyzed by coculturing tumor cells with macrophages. Cell activity was detected by coculturing with CD8(+) T cells, and tumor immune responses were examined by immunofluorescence and cytokine detection. In vitro tube formation was used to simulate angiogenesis, and angiogenesis ability was detected. Western blot was used to analyze the expression of vascular endothelial cell markers, and calcium-tracer dyes were used to detect calcium ion (Ca2+) influx in endothelial cells. Results: GAD1 expression and GABA level in MDA-MB-231 cells were significantly higher than those in normal cells (P <0.01). GAD1 overexpression enhanced cell proliferation, invasion, and migration abilities and simultaneously promoted macrophage polarization to M2, releasing protumor factors interleukin-10 and transforming growth factor-beta and inhibiting the antitumor effect of M1-type macrophages (P <0.05). GAD1 inhibition had the opposite effect (P <0.01). GAD1 overexpression also suppressed the activity of CD8(+) T cells; decreased the expression of programmed death-1 in CD8(+)T cells and the levels of interferon-gamma, perforin, and granzyme B; weakened the immune response; and promoted tumor angiogenesis (P <0.05). The number of in vitro vascular lumen formation increased, the expression of vascular markers rose, and Ca2+ influx was enhanced (P <0.01). Reverse operation demonstrated that GABA promoted the initiation and advancement of BC by regulating the immune microenvironment and angiogenesis (P <0.05). Conclusion: GAD1 is highly expressed in BC. Increasing GABA synthesis promotes tumor cell proliferation and metastasis, regulates the immune microenvironment toward immunosuppression, and enhances tumor angiogenesis. This work reveals the crucial role of the GAD1-GABA pathway in BC and provides a potential therapeutic target for this disease.
