Cholesterol suppresses AMFR-mediated PDL1 ubiquitination and degradation in HCC.

The degradation of proteasomes or lysosomes is emerging as a principal determinant of programmed death ligand 1 (PDL1) expression, which affects the efficacy of immunotherapy in various malignancies. Intracellular cholesterol plays a central role in maintaining the expression of membrane receptors; however, the specific effect of cholesterol on PDL1 expression in cancer cells remains poorly understood. Cholesterol starvation and stimulation were used to modulate the cellular cholesterol levels. Immunohistochemistry and western blotting were used to analyze the protein levels in the samples and cells. Quantitative real-time PCR, co-immunoprecipitation, and confocal co-localization assays were used for mechanistic investigation. A xenograft tumor model was constructed to verify these results in vivo. Our results showed that cholesterol suppressed the ubiquitination and degradation of PDL1 in hepatocellular carcinoma (HCC) cells. Further mechanistic studies revealed that the autocrine motility factor receptor (AMFR) is an E3 ligase that mediated the ubiquitination and degradation of PDL1, which was regulated by the cholesterol/p38 mitogenic activated protein kinase axis. Moreover, lowering cholesterol levels using statins improved the efficacy of programmed death 1 (PD1) inhibition in vivo. Our findings indicate that cholesterol serves as a signal to inhibit AMFR-mediated ubiquitination and degradation of PDL1 and suggest that lowering cholesterol by statins may be a promising combination strategy to improve the efficiency of PD1 inhibition in HCC.

A machine learning model utilizing delphian lymph node characteristics to predict contralateral central lymph node metastasis in papillary thyroid carcinoma: A prospective multicenter study.

BACKGROUND: This study aimed to use artificial intelligence (AI) to integrate various radiological and clinical pathological data to identify effective predictors of contralateral cervical lymph node metastasis (CCLNM) in patients with papillary thyroid carcinoma (PTC) and to establish a clinically applicable model to guide the extent of surgery. METHODS: This prospective cohort study included 603 patients with PTC from three centers. Clinical, pathological, and ultrasonographic data were collected and utilized to develop a machine learning (ML) model for predicting CCLNM. Model development at the internal center utilized logistic regression along with other ML algorithms. Diagnostic efficacy was compared among these methods, leading to the adoption of the final model (random forest). This model was subject to AI interpretation and externally validated at other centers. RESULTS: CCLNM was associated with multiple pathological factors. The Delphian lymph node metastasis ratio, ipsilateral cervical lymph node metastasis number, and presence of ipsilateral cervical lymph node metastasis were independent risk factors for CCLNM. Following feature selection, a Delphian lymph node-CCLNM (D-CCLNM) model was established using the Random forest algorithm based on five attributes. The D-CCLNM model demonstrated the highest area under the curve (AUC; 0.9273) in the training cohort and exhibited high predictive accuracy, with AUCs of 0.8907 and 0.9247 in the external and validation cohorts, respectively. CONCLUSIONS: We developed a new, effective method that uses ML to predict CCLNM in patients with PTC. This approach integrates data from Delphian lymph nodes and clinical characteristics, offering a foundation for guiding surgical decisions, and is conveniently applicable in clinical settings.

Development of a fluorescent ligand that specifically binds to the c-MYC G-quadruplex by migrating the benzene group on a carbazole-benzothiazolium scaffold.

c-MYC is one of the most important oncogenes, which is overexpressed in many cancers, and is highly related to development, metastasis, and drug resistance of cancers. The G4 structure in the promoter of c-MYC oncogene contributes a lot to the gene transcriptional mechanism. Small-molecule ligands binding to the c-MYC G4 appear to be a new class of anticancer agents. However, selective ligands for the c-MYC G4 over other G4s have been rarely reported. In this study, we reported a novel fluorescent ligand by migrating the benzene group on a carbazole-benzothiazolium scaffold, which was demonstrated to exhibit considerable specificity to the c-MYC G4, which was distinguished from other small-molecule ligands. The further cellular experiments suggested that this ligand may indeed target the promoter G4 and cause apparent transcriptional inhibition of the c-MYC oncogene instead of other G4-mediated oncogenes, which thereby resulted in cancer cell growth inhibition. Collectively, this study provided a good example for developing specific c-MYC G4 ligands, which may further develop into an effective anticancer agent that inhibit the c-MYC expression.

Promising G-Quadruplex-Targeted Dibenzoquinoxaline Type-1 Photosensitizer Triggers DNA Damage in Triple-Negative Breast Cancer Cells.

G-quadruplexes (G4s) are potential drug targets in cancer treatment. However, the G4-targeted ligands seem to lack sufficient selectivity between tumors and normal tissues, appealing for a new modified anticancer strategy on the basis of them. Type-1 photodynamic therapy (PDT) is a promising strategy possessing excellent spatiotemporal precision for solid tumors with a hypoxic microenvironment. However, type-1 photosensitizers that target G4s and induce in situ photodamage have never been previously reported. In this study, we reported a promising type-1 photosensitizer based on a G4-targeted, high-contrast fluorescent ligand (TR2). The subsequent studies demonstrated that TR2 could transfer from lysosomes to nuclei and induce elevated G4 formation as well as DNA damage upon irradiation. Notably, it was observed that TR2 may not activate DNA damage repair machinery upon irradiation, suggesting a durable, strong effect on inducing DNA damage. Consequently, light-irradiated TR2 exhibited excellent photocytotoxicity on triple-negative breast cancer cell proliferation (at nanomolar concentration) and showed obvious inhibition on the growth of three-dimensional (3D) tumor spheroids. Finally, RNA-seq analysis demonstrated that TR2-mediated PDT may have a negative impact on enhancing the DNA damage repair machinery and may activate the antitumor immunity pathways. Overall, this study provided a promising chemical tool for image-guided PDT.

Deubiquitination of CIB1 by USP14 promotes lenvatinib resistance via the PAK1-ERK1/2 axis in hepatocellular carcinoma.

Background: Lenvatinib is the most common multitarget receptor tyrosine kinase inhibitor for the treatment of advanced hepatocellular carcinoma (HCC). Acquired resistance to lenvatinib is one of the major factors leading to the failure of HCC treatment, but the underlying mechanism has not been fully characterized. Methods: We established lenvatinib-resistant cell lines, cell-derived xenografts (CDXs) and patient-derived xenografts (PDXs) and obtained lenvatinib-resistant HCC tumor tissues for further study. Results: We found that ubiquitin-specific protease 14 (USP14) was significantly increased in lenvatinib-resistant HCC cells and tumors. Silencing USP14 significantly attenuated lenvatinib resistance in vitro and in vivo. Mechanistically, USP14 directly interacts with and stabilizes calcium- and integrin-binding protein 1 (CIB1) by reversing K48-linked proteolytic ubiquitination at K24, thus facilitating the P21-activated kinase 1 (PAK1)-ERK1/2 signaling axis. Moreover, in vivo adeno-associated virus 9 mediated transduction of CIB1 promoted lenvatinib resistance in PDXs, whereas CIB1 knockdown resensitized the response of PDXs to lenvatinib. Conclusions: These findings provide new insights into the role of CIB1/PAK1-ERK1/2 signaling in lenvatinib resistance in HCC. Targeting CIB1 and its pathways may be a novel pharmaceutical intervention for the treatment of lenvatinib-resistant HCC.

Clinical features and treatment of apoplectic intratumoral hemorrhage of glioma.

OBJECTIVE: The primary objective of this study was to explore the clinical characteristics of apoplectic intratumoral hemorrhage in gliomas and offer insights for improving the diagnosis and treatment of this disease. METHODS: We analyzed the clinical data of 35 patients with glioma and hemorrhage. There were eight cases of multiple cerebral lobe involvement, and 22 cases involved a single lobe. Twenty-one patients had a preoperative Glasgow Coma Scale (GCS) score of ≥ 9 and had a craniotomy with tumor resection and hematoma evacuation after undergoing preoperative preparation. A total of 14 patients with GCS < 9, including one with thalamic hemorrhage breaking into the ventricles and acute obstructive hydrocephalus, underwent craniotomy for tumor resection after external ventricular drainage (EVD). One patient had combined thrombocytopenia, which was surgically treated after platelet levels were normalized through transfusion. The remaining 12 patients received immediate intervention in the form of craniotomy hematoma evacuation and tumor resection. RESULTS: We performed subtotal resection on three tumors of thalamic origin and two tumors of corpus callosum origin, but we were able to successfully resect all the tumors in other locations that were gross total resection Pathology results showed that 71.43% of cases accounted for WHO-grade 4 tumors. Among the 21 patients with a GCS score of ≥ 9, two died perioperatively. Fourteen patients had a GCS score < 9, of which eight patients died perioperatively. CONCLUSIONS: Patients with a preoperative GCS score ≥ 9 who underwent subemergency surgery and received aggressive treatment showed a reasonable prognosis. We found their long-term outcomes to be correlated with the pathology findings. On the other hand, patients with a preoperative GCS score < 9 required emergency treatment and had a high perioperative mortality rate.

The effectiveness of dexmedetomidine for preventing acute kidney injury after surgery: a systematic review and meta-analysis.

Background: Postoperative acute kidney injury (AKI) is a serious and distressing complication connected to various adverse outcomes following the surgical operation. Controversy remains regarding the dexmedetomidine's preventive impact on postoperative AKI. Therefore, this investigation aims to explore the efficiency and safety of dexmedetomidine in preventing AKI after surgical operation. Methods: We systematically searched electronic databases such as PubMed, Embase, Web of Science, and the Cochrane Library to detect eligible randomized controlled studies that used dexmedetomidine for the prevention of AKI following operation up to April 30, 2023. The main outcome evaluated was AKI incidence. The evidence quality was assessed employing the Grading of Recommendations Assessment, Development, and Evaluation. Results: The meta-analysis included 25 trials, including 3,997 individuals. Of these, 2,028 were in the dexmedetomidine group, and 1,969 were in the control group. The result showed that patients administered dexmedetomidine significantly decreased the AKI incidence following surgical operation in contrast to the control group (risk ratio, 0.60; 95% confidence intervals, 0.45-0.78; p < 0.05; I 2 = 46%). In addition, dexmedetomidine decreased the period of hospitalization in both the intensive care unit (ICU) and the hospital while also reducing postoperative delirium (POD) occurrence. However, dexmedetomidine elevated the incidence of bradycardia but did not have a significant impact on other indicators. Conclusion: Our meta-analysis indicates that the dexmedetomidine treatment reduces the postoperative AKI and POD risk while also shortening the time of hospitalization in the ICU and hospital. However, it is connected to an increased bradycardia risk.

Impact of age and donor sites on bioactivities of tendon cells in autologous tenocyte implantation (OrthoATI™) for treatment of chronic tendinopathy.

OBJECTIVES: Autologous tenocyte implantation (OrthoATI™) therapy has demonstrated efficacy in treating patients with tendinopathy at various anatomical sites. This study evaluates the effect of patient age, gender, and tendon biopsy site on morphology, growth, and gene expression of autologous tendon cells used to treat chronic tendinopathy. METHODS: Patients undergoing OrthoATI™ for tendinopathies between 2020 and 2022 were initially treated by biopsies taken from patella tendon (PT) or palmaris longus tendon (PL). The biopsies were sent to a Good Manufacturing Practice (GMP) cell laboratory where tendon cells were isolated, cultured, and expanded for four to six weeks. Cell morphology was assessed using phase contrast microscopy. Droplet digital PCR (ddPCR) was utilized for gene expression analysis. Dichotomous results were compared between groups using x2 or Fisher's exact tests with no adjustment for multiple comparisons. The nonparametric Mann-Whitney U and Kruskal-Wallis tests were utilized for the sex and age (<35y, 35-44y, 45-54y, >55y) analyses, respectively. All analyses were performed using IBM SPSS v27, and a two-tailed P-value of <0.05 was considered statistically significant. RESULTS: 149 patients were included in the analysis. The PT was biopsied in 63 patients, and PL in 86 patients. There were no observer effects for age and gender between the PT and PL groups. There was no statistical significance between the PT and PL tendons for cell morphology, average cell population doubling time (PDT) (PT 83.9 vs PL 82.7 â€‹h, p â€‹= â€‹0.482), cellular yield (PT 16.2 vs PL 15.2 â€‹× â€‹106, p â€‹= â€‹0.099), and cell viability (PT 98.7 vs PL 99.0%, p â€‹= â€‹0.277). Additionally, ddPCR analyses showed no statistical significance found in tenogenic gene expression, including collagen type I (COL1, p â€‹= â€‹0.86), tenomodulin (TNMD, p â€‹= â€‹0.837) and scleraxis (SCX, p â€‹= â€‹0.331) between PT- and PL-derived tendon cells. An age stratification analysis found no effect on growth and gene expression. COL1 was found to be higher in males when compared to females (P â€‹< â€‹0.001), but otherwise no difference was seen in growth and gene expression in the gender analysis. No postbiopsy clinical complications were reported for either group. CONCLUSION: This study has shown that the growth and bioactivities of tendon cells from tendon biopsies for OrthoATI™ are not affected by tendon donor site and age. LEVEL OF EVIDENCE: IV.

CXCL9 Overexpression Predicts Better HCC Response to Anti-PD-1 Therapy and Promotes N1 Polarization of Neutrophils.

Background: Anti-programmed death-1 (PD1) antibodies have changed the treatment landscape for hepatocellular carcinoma (HCC) and exhibit promising treatment efficacy. However, the majority of HCCs still do not respond to anti-PD-1 therapy. Methods: We analyzed the expression of CXCL9 in blood samples from patients who received anti-PD-1 therapy and evaluated its correlation with clinicopathological characteristics and treatment outcomes. Based on the results of Cox regression analysis, a nomogram was established for predicting HCC response to anti-PD-1 therapy. qRT‒PCR and multiple immunofluorescence assays were utilized to analyze the proportions of N1-type neutrophils in vitro and in tumor samples, respectively. Results: The nomogram showed good predictive efficacy in the training and validation cohorts and may be useful for guiding clinical treatment of HCC patients. We also found that HCC cell-derived CXCL9 promoted N1 polarization of neutrophils in vitro and that AMG487, a specific CXCR3 inhibitor, significantly blocked this process. Moreover, multiple immunofluorescence (mIF) showed that patients with higher serum CXCL9 levels had greater infiltration of the N1 phenotype of tumor-associated neutrophils (TANs). Conclusion: Our study highlights the critical role of CXCL9 as an effective biomarker of immunotherapy efficacy and in promoting the polarization of N1-type neutrophils; thus, targeting the CXCL9-CXCR3 axis could represent a novel pharmaceutical strategy to enhance immunotherapy for HCC.

Case report: Rapidly progressive desmoid tumor after surgery for esophagogastric junction cancer and slowly progressive primary desmoid tumor: a report of two cases and literature review.

Background: Desmoid tumor (DT) is a rare locally aggressive but non-metastatic mesenchymal soft tissue neoplasm that predominantly occurs in the abdominal wall, abdominal cavity, and extremities. Its occurrence in the mesentery is relatively uncommon. Case reports: This article reports two cases of desmoid tumor treated at the Department of Gastrointestinal Surgery, Weifang People's Hospital. The first case was a 59-year-old male patient who had previously undergone surgery for esophagogastric junction cancer. Postoperatively, he developed an intra-abdominal mass that rapidly increased in size within three months. The second case was a 60-year-old male patient who incidentally discovered a mass in the left lower abdomen. Both patients underwent surgical treatment, and the postoperative pathological diagnosis was mesenteric desmoid tumor. Conclusion: The treatment of desmoid tumor remains challenging. Simple surgical resection often yields unsatisfactory outcomes, and the efficacy of adjuvant radiotherapy and chemotherapy is also limited. Further research and clinical practice are necessary to improve diagnostic and therapeutic strategies, aiming to enhance patient survival and quality of life.

Impact of nondiameter aortic indices on surgical eligibility: Results from the Treatment in Thoracic Aortic Aneurysm: Surgery Versus Surveillance (TITAN: SvS) randomized controlled trial.

OBJECTIVES: Traditional criterion for intervention on an asymptomatic ascending aortic aneurysm has been a maximal aortic diameter of 5.5 cm or more. The 2022 American College of Cardiology/American Heart Association aortic guidelines adopted cross-sectional aortic area/height ratio, aortic size index, and aortic height index as alternate parameters for surgical intervention. The objective of this study was to evaluate the impact of using these newer indices on patient eligibility for surgical intervention in a prospective, multicenter cohort with moderate-sized ascending aortic aneurysms between 5.0 and 5.4 cm. METHODS: Patients enrolled from 2018 to 2023 in the randomization or registry arms of the multicenter trial, Treatment In Thoracic Aortic aNeurysm: Surgery versus Surveillance, were included in the study. Clinical data were captured prospectively in an online database. Imaging data were derived from a core computed laboratory. RESULTS: Among the 329 included patients, 20% were female. Mean age was 65.0 ± 11.6 years, and mean maximal aortic diameter was 50.8 ± 3.9 mm. In the one-third of all patients (n = 109) who met any 1 of the 3 criteria (ie, aortic size index ≥3.08 cm/m2, aortic height index ≥3.21 cm/m, or cross-sectional aortic area/height ≥ 10 cm2/m), their mean maximal aortic diameter was 52.5 ± 0.52 mm. Alternate criteria were most commonly met in women compared with men: 20% versus 2% for aortic size index (P < .001), 39% versus 5% for aortic height index (P < .001), and 39% versus 21% for cross-sectional aortic area/height (P = .002), respectively. CONCLUSIONS: One-third of patients in Treatment In Thoracic Aortic aNeurysm: Surgery versus Surveillance would meet criteria for surgical intervention based on novel parameters versus the classic definition of diameter 5.5 cm or more. Surgical thresholds for aortic size index, aortic height index, or cross-sectional aortic area/height ratio are more likely to be met in female patients compared with male patients.

Single-cell analysis of anti-BCMA CAR T cell therapy in patients with central nervous system autoimmunity.

Chimeric antigen receptor (CAR) T cell immunotherapy for the treatment of neurological autoimmune diseases is promising, but CAR T cell kinetics and immune alterations after treatment are poorly understood. Here, we performed single-cell multi-omics sequencing of paired cerebrospinal fluid (CSF) and blood samples from patients with neuromyelitis optica spectrum disorder (NMOSD) treated with anti-B cell maturation antigen (BCMA) CAR T cells. Proliferating cytotoxic-like CD8+ CAR T cell clones were identified as the main effectors in autoimmunity. Anti-BCMA CAR T cells with enhanced features of chemotaxis efficiently crossed the blood-CSF barrier, eliminated plasmablasts and plasma cells in the CSF, and suppressed neuroinflammation. The CD44-expressing early memory phenotype in infusion products was potentially associated with CAR T cell persistence in autoimmunity. Moreover, CAR T cells from patients with NMOSD displayed distinctive features of suppressed cytotoxicity compared with those from hematological malignancies. Thus, we provide mechanistic insights into CAR T cell function in patients with neurological autoimmune disease.

Novel quinoxaline analogs as telomeric G-quadruplex ligands exert antitumor effects related to enhanced immunomodulation.

G-quadruplexes (G4s) are commonly formed in the G-rich strand of telomeric DNA. Ligands targeting telomeric G4 induce DNA damage and telomere dysfunction, which makes them potential antitumor drugs. New telomeric G4 ligands with drug-likeness are still needed to be exploited, especially with their antitumor mechanisms thoroughly discussed. In this study, a novel series of quinoxaline analogs were rationally designed and synthesized. Among them, R1 was the most promising ligand for its cytotoxic effects on tumor cells and stabilizing ability with telomeric G4. Cellular assays illustrated that R1 stabilized G4 and induced R-loop accumulation in the telomeric regions, subsequently triggering DNA damage responses, cell cycle arrest in G2/M phase, apoptosis and antiproliferation. Moreover, R1 evoked immunogenic cell death (ICD) in tumor cells, which promoted the maturation of bone marrow derived dendritic cells (BMDCs). In breast cancer mouse model, R1 exhibited a significant decrease in tumor burden through the immunomodulatory effects, including the increase of CD4+ and CD8+ T cells in tumors and cytokine levels in sera. Our research provides a new idea that targeting telomeric G4 induces DNA damage responses, causing antitumor effects both in vitro and in vivo, partially due to the enhancement of immunomodulation.

Skin mottling score assesses peripheral tissue hypoperfusion in critically ill patients following cardiac surgery.

BACKGROUND: Skin mottling is a common manifestation of peripheral tissue hypoperfusion, and its severity can be described using the skin mottling score (SMS). This study aims to evaluate the value of the SMS in detecting peripheral tissue hypoperfusion in critically ill patients following cardiac surgery. METHODS: Critically ill patients following cardiac surgery with risk factors for tissue hypoperfusion were enrolled (n = 373). Among these overall patients, we further defined a hypotension population (n = 178) and a shock population (n = 51). Hemodynamic and perfusion parameters were recorded. The primary outcome was peripheral hypoperfusion, defined as significant prolonged capillary refill time (CRT, > 3.0 s). The characteristics and hospital mortality of patients with and without skin mottling were compared. The area under receiver operating characteristic curves (AUROC) were used to assess the accuracy of SMS in detecting peripheral hypoperfusion. Besides, the relationships between SMS and conventional hemodynamic and perfusion parameters were investigated, and the factors most associated with the presence of skin mottling were identified. RESULTS: Of the 373-case overall population, 13 (3.5%) patients exhibited skin mottling, with SMS ranging from 1 to 5 (5, 1, 2, 2, and 3 cases, respectively). Patients with mottling had lower mean arterial pressure, higher vasopressor dose, less urine output (UO), higher CRT, lactate levels and hospital mortality (84.6% vs. 12.2%, p < 0.001). The occurrences of skin mottling were higher in hypotension population and shock population, reaching 5.6% and 15.7%, respectively. The AUROC for SMS to identify peripheral hypoperfusion was 0.64, 0.68, and 0.81 in the overall, hypotension, and shock populations, respectively. The optimal SMS threshold was 1, which corresponded to specificities of 98, 97 and 91 and sensitivities of 29, 38 and 67 in the three populations (overall, hypotension and shock). The correlation of UO, lactate, CRT and vasopressor dose with SMS was significant, among them, UO and CRT were identified as two major factors associated with the presence of skin mottling. CONCLUSION: In critically ill patients following cardiac surgery, SMS is a very specific yet less sensitive parameter for detecting peripheral tissue hypoperfusion.

Basilic vein variation encountered during surgery for arm vein port: A case report.

BACKGROUND: Venous variations are uncommon and usually hard to identify, and basilic vein variation is particularly rare. Basilic vein variation usually presents without any clinical symptoms and is often regarded as a benign alteration. This case was a patient with congenital basilic vein variation encountered during surgery for an infusion port. CASE SUMMARY: We documented and analyzed an uncommon anatomical variation in the basilic vein encountered during arm port insertion. This peculiarity has hitherto remained undescribed in the literature. We offer remedial strategies for addressing this anomaly in the future and precautionary measures to circumvent its occurrence. We conducted a comprehensive review of analogous cases in the literature, offering pertinent therapeutic recommendations and solutions, with the aim of enhancing the efficacy and safety of future arm port implantations. CONCLUSION: Venous variation is rare and requires detailed intraoperative and postoperative examination to ensure accuracy, so as not to affect subsequent treatment.

A study of high dose furmonertinib in EGFR exon 20 insertion mutation-positive advanced non-small cell lung cancer.

Background: The epidermal growth factor receptor (EGFR) ex20ins mutation, as a rare subtype of mutation, has gradually attracted attention. Its heterogeneity is high, its prognosis is extremely poor, and the efficacy of existing traditional treatment plans is limited. In this study, we aimed to evaluate efficacy of high dose furmonertinib as a first-line treatment for EGFR ex20ins-positive NSCLC. Methods: This is a retrospective, multi-center, non-interventional study. From May 2021 to March 2023, 9 NSCLC patients with EGFR ex20ins were enrolled. Efficacy and safety of 160 mg furmonertinib were evaluated. Objective response rate (ORR), disease control rate (DCR), median progression-free survival (PFS) and treatment related adverse events (TRAEs) were assessed. Results: Of the evaluated patients, six patients experienced partial remission (PR), two patients experienced stable disease (SD) and one patient experienced progress disease (PD). Data indicated 66.7% ORR and 88.9% DCR. The median progression free survival (PFS) was 7.2 months (95% CI: 6.616 - 7.784). Besides, a longgest PFS with 18 months was found in one patient with p.H773_V774insGTNPH mutation. No ≥ level 3 adverse events have been found. Conclusions: The study proved the potential efficacy of 160mg furmonertinib in patients with advanced NSCLC with EGFR ex20ins. Meanwhile, 160mg furmonertinib had a good safety profile.

Development of a fluorescent ligand that can illuminate nuclear G-quadruplexes and modulate oncogene expression.

In this study, we developed a promising dual-function fluorescent ligand termed KS-1 by a slight structural modification on a reported carbazole-based scaffold. KS-1 was then found to mainly bind and illuminate the nuclear DNA G-quadruplexes (G4s) in a sandwich-like interacting mode, and also effectively modulate the oncogene expression through a G4-mediated manner. Furthermore, KS-1 was proved to inhibit cancer cell growth either in 2D monolayer cells or 3D multicellular tumor spheroids. To be noted, this ligand could overcome the shortcomings of other reported dual-function ligands that appeared to accumulate in the lysosomes or mitochondria, and may be used as a theranostic agent in the future.

Discovery of a triphenylamine-based ligand that targets mitochondrial DNA G-quadruplexes and activates the cGAS-STING immunomodulatory pathway.

Stabilization of G-quadruplex (G4) structures in mitochondria leads to the damage of mitochondrial DNA (mtDNA), making mtDNA G4s a promising target in the field of cancer therapy in recent years. Damaged mtDNA released into the cytosol can stimulate cytosolic DNA-sensing pathways, and cGAS-STING pathway is a typical one with potent immunostimulatory effects. A few small molecule ligands of mtDNA G4s are identified with antitumor efficacy, but little is known about their results and mechanisms on immunomodulation. In this study, we engineered a series of triphenylamine-based analogues targeting mtDNA G4s, and A6 was determined as the most promising compound. Cellular studies indicated that A6 caused severe mtDNA damage. Then, damaged mtDNA stimulated cGAS-STING pathway, resulting in the following cytokine production of tumor cells and the maturation of DCs. In vivo experiments certified that A6 exerted suppressive influences on tumor growth and metastasis in 4T1 cell-bearing mice by the regulation of TME, including the remodeling of macrophages and the activation of T cells. To our knowledge, it is the first time to report a ligand targeting mtDNA G4s to activate the cGAS-STING immunomodulatory pathway, providing a novel strategy for the future development of mtDNA G4-based antitumor agents.