Inhibited Tumor Cell Proliferation Research Articles

The potential of kaempferol in digestive system tumors: recent advances and mechanistic insights.

Digestive system neoplasms are a heterogeneous group of cancers characterized by diverse symptoms, complex diagnosis, and treatment. Prognosis is poor and influenced by multiple factors, making early detection and comprehensive treatment crucial for patient survival. Kaempferol, a flavonoid compound, has attracted attention due to its anti-tumor biological activity, holding promise as a potential drug for treating digestive system neoplasms. Derived from various plants such as cabbage, propolis, and grapefruit, this compound's anti-inflammatory, antioxidant, and other pharmacological effects have been confirmed. Research has found that kaempferol inhibits the occurrence and development of digestive system neoplasms by inducing apoptosis in cancer cells, inhibiting tumor cell proliferation, suppressing tumor metastasis and invasion, and enhancing the effects of other cancer treatment methods. This paper summarizes the role and mechanisms of kaempferol in the study of digestive system neoplasms, providing valuable insights for both scientists and clinical physicians engaged in this field. By detailing the various pathways through which kaempferol exerts its anticancer effects, the paper not only highlights its potential as a therapeutic agent but also opens avenues for further research into its applications.

Population Pharmacokinetics of Tamibarotene in Pediatric and Young Adult Patients with Recurrent or Refractory Solid Tumors

Tamibarotene is a synthetic retinoid that inhibits tumor cell proliferation and promotes differentiation. We previously reported on the safety and tolerability of tamibarotene in patients with recurrent or refractory solid tumors. Therefore, in this study, we aimed to evaluate the pharmacokinetic properties of tamibarotene and construct a precise pharmacokinetic model. We also conducted a non-compartmental analysis and population pharmacokinetic (popPK) analysis based on the results of a phase I study. Targeted pediatric and young adult patients with recurrent or refractory solid tumors were administered tamibarotene at doses of 4, 6, 8, 10, and 12 g/m2/day. Serum tamibarotene concentrations were evaluated after administration, and a popPK model was constructed for tamibarotene using Phoenix NLME. During model construction, we considered the influence of various parameters (weight, height, body surface area, and age) as covariates. Notably, 22 participants were included in this study, and 109 samples were analyzed. A two-compartment model incorporating lag time was selected as the base model. In the final model, the body surface area was included as a covariate for apparent total body clearance, the central compartment volume of distribution, and the peripheral compartment volume of distribution. Visual prediction checks and bootstrap analysis confirmed the validity and predictive accuracy of the final model as satisfactory.

Mechanistic insights into traditional Chinese medicine for digestive tract cancers: implications for gastric, hepatic, esophageal, intestinal, and pancreatic tumors

Abstract The increasing incidence of cancer-related deaths highlights the pressing need for effective treatment modalities, particularly in the context of digestive tract cancers, such as gastric, hepatic, esophageal, intestinal, and pancreatic tumors. While conventional drug therapies play a critical role in managing these malignancies, their associated side effects often pose significant challenges to patient quality of life. Thus, there is a growing focus on traditional Chinese medicine (TCM) and its compounds, which are safe, non-toxic, and reliable. During anti-tumor therapy, TCM compounds, based on their multi-target, multi-pathway, and multi-level regulatory effects, fully mobilize multiple mechanisms of the body, presenting significant advantages in inhibiting tumor development, boosting patient welfare, and increasing their lifespan. This article reviews the mechanisms by which TCM inhibits tumor cell proliferation, promotes tumor cell death, suppresses tumor cell invasion and metastasis, regulates the tumor microenvironment, inhibits angiogenesis, and enhances anti-tumor drug resistance. This knowledge might provide a theoretical and scientific basis for preventing and treating tumors using TCM.

DDDR-03. DEVELOPMENT OF ANTI-TUMOR AROMA THERAPY FOR GLIOBLASTOMA WITH LEMONGRASS ESSENTIAL OIL

Abstract INTRODUCTION Aroma essential oils apply to cancer therapy because of their immune-enhancing and sedative effects, and their ability to reduce the side effects of chemotherapy. Recently, aroma essential oils have also been reported to have anti-tumor effects. We investigate the anti-tumor effects of aromatic compounds contained in essential oils as a novel treatment for glioblastoma. In this study, we analyzed the antitumor effect of lemongrass essential oil and investigated its antitumor aroma therapy for glioblastoma. methods and RESULTS Human glioblastoma cells (U87, T98G) and mouse brain tumor cells (RSV-M) were used in the study. Tumor cells were cultured in the presence of lemongrass essential oil for 72 hours, and the growth inhibitory effect was observed, suggesting that the evaporated lemongrass essential oil components acted on tumor cells in the vicinity. In addition, a similar effect was observed with citral alone, which is the main component of lemongrass. Analysis of the effects of citral revealed that citral strongly binds to MARK4 and inhibits its enzyme activity, and that citral decreases the phosphorylation of tau protein. Next, a mouse brain tumor model with RSV-M was established, and the anti-tumor effect of lemongrass essential oil was studied. The results showed that the mice that inhaled lemongrass essential oil for 12 h/day had a significantly prolonged survival period compared to the control group. DISCUSSION Citral is the main component of lemongrass essential oil, which contains 70-80% of lemongrass essential oil. This study suggests a mechanism of inhibition of tumor cell proliferation by citral in malignant gliomas. Citral is a volatile monoterpene, and its anti-tumor effect was demonstrated by diffusion through evaporation. CONCLUSION Citral in lemongrass essential oil shows anti-tumor effects and is expected to be applied to a new glioblastoma therapy using “aroma”

Living photosynthetic microneedle patches for in situ oxygenation and postsurgical melanoma therapy.

Surgical excision remains the principal treatment for melanoma, while tumor recurrence and delayed wound healing often occur due to the residual tumor cells and hypoxic microenvironment in the postoperative skin wounds. Herein, we present a living photosynthetic microneedle (MN) patch (namely MA/CM@MN) loaded with microalgae (MA) and cuttlefish melanin (CM) for postsurgical melanoma therapy and skin wound healing. Benefiting from the oxygenic photosynthesis of the alive MA in the MN base, the MA/CM@MN can generate oxygen under light exposure, thus facilitating skin cell proliferation and protecting cells against hypoxia-induced cell death. In addition, with CM nanoparticles embedded in the MN tips, the MA/CM@MN can be effectively heated up under near-infrared (NIR) irradiation, contributing to a strong tumor killing efficacy on melanoma cells in vitro. Further experiments demonstrate that the NIR-irradiated MA/CM@MN effectively prevents local tumor recurrence and simultaneously promotes the healing of tumor-induced wounds after incomplete tumor resection in melanoma-bearing mice, probably because the MA/CM@MN can inhibit tumor cell proliferation, stimulate tumor cell apoptosis, and mitigate tissue hypoxia in light. These results indicate that the living photosynthetic MN patch offers an effective therapeutic strategy for postoperative cancer therapy and wound healing applications.

DDDR-47. TARGETING HTR2B SUPPRESSES NON-FUNCTIONING PITUITARY ADENOMA GROWTH AND SENSITIZES CABERGOLINE TREATMENT VIAINHIBITING GΑQ/PLC/PKCΓ/STAT3 AXIS

Abstract BACKGROUND Managing non-functioning pituitary adenomas (NFPAs) is difficult due to limited drug treatments. Cabergoline’s (CAB) effectiveness for NFPAs is debated. This study explores the role of HTR2B in NFPAs and its therapeutic potential. METHODS We conducted screening of bulk RNA-sequencing data to analyze HTR2B expression levels in NFPA samples. In vitro and in vivo experiments were performed to evaluate the effects of HTR2B modulation on tumor growth and cell cycle regulation. Mechanistic insights into the HTR2B-mediated signaling pathway were elucidated using pharmacological inhibitors and molecular interaction assays. RESULTS Elevated HTR2B expression was detected in NFPA samples, which was associated with increased tumor survival. Inhibition of HTR2B activity resulted in the suppression of tumor growth through modulation of the G2M cell cycle. The inhibition of HTR2B with PRX-08066 was found to block STAT3 phosphorylation and nuclear translocation by interfering with the Gαq/PLC/PKC pathway. A direct interaction between PKC-γ and STAT3 was critical for STAT3 activation. CAB was shown to activate pSTAT3 via HTR2B, reducing its therapeutic potential. However, the combination of an HTR2B antagonist with CAB significantly inhibited tumor cell proliferation in HTR2B-expressing pituitary tumor cell lines, a xenografted pituitary tumor model, and patient-derived samples. Analysis of patient-derived data indicated that a distinct molecular pattern characterized by upregulated HTR2B/PKC-γ and downregulated BTG2/GADD45A may benefit from combination treatment with CAB and PRX-08066.

Dysregulation of R-loop homeostasis shapes the immunosuppressive microenvironment and induces malignant progression in melanoma.

Dysregulated R-loop homeostasis leads to DNA replication stress and genomic instability, a major driver of cancer. However, the role of R-loops in melanoma development remains unclear. We established an R-loop scoring model based on a single-cell RNA sequencing dataset and evaluated the association between the R-loop score with the melanoma immune microenvironment and treatment response. We explored the role of CENPA-mediated changes in R-loop distribution during melanoma progression by DNA/RNA immunoprecipitation and sequencing and a series of functional experiments. We found that malignant cells with high R-loop scores may be involved in melanoma progression by modulating immune evasion, metabolic reprogramming, and cancer-related pathways. A cell communication analysis revealed that high-score R-loops play an important role in altering cell-cell interactions and limiting the CD8 + cytotoxic T cell response and T cell accumulation. CENPA silencing induced changes in R-loop distribution, upregulated Hippo signaling activity, and inhibited tumor cell proliferation and migration. Moreover, the R-loop score can predict the prognosis and immunotherapy effect of melanoma patients. Our work reveals the potential molecular mechanism by which abnormal R-loops promote melanoma progression, which may help develop anticancer therapies based on R-loops or R-loop regulators.

Deciphering the oncogenic potential of ADAM9 in hepatocellular carcinoma through bioinformatics and experimental approaches

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. This study investigates the role and mechanisms of ADAM9 as a biomarker and potential therapeutic target in HCC. Utilizing RNA-sequencing data and clinicopathological characteristics from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we conducted survival and meta-analyses, functional enrichment, and immune infiltration studies. Additionally, we evaluated the effects of ADAM9 silencing on HCC cell proliferation, migration, and invasion through in vitro experiments. Our results demonstrate that high ADAM9 expression is associated with poor prognosis and increased immune infiltration in HCC patients. Furthermore, ADAM9 knockdown significantly inhibited tumor cell proliferation and migration. These findings indicate that ADAM9 is a promising prognostic biomarker and potential therapeutic target in HCC. In conclusion, ADAM9 could offer avenues for developing strategies to inhibit tumor progression and improve patient outcomes.

Structural characterization and potential antitumor and immunostimulatory activities of mycelial polysaccharides from Ophiocordyceps gracilis

Ophiocordyceps gracilis (O. gracilis), the same genus as Ophiocordyceps sinensis, has been used as an edible medicinal fungus for many years. However, the active ingredients of O. gracilis polysaccharides remain relatively unknown. To address this, a 310.1kDa novel polysaccharide (PDP-1a) was isolated from O. gracilis. The structural characteristics of PDP-1a were determined by different spectroscopy analyses, revealing that PDP-1a was α-glucan homologs with →4)-α-Glcp(1→ as the main chain. Furthermore, PDP-1a inhibited tumor cell proliferation, particularly in the A549 cell line, with a cell death mechanism involving cell cycle blockage, mitochondrial membrane potential reduction, and increased reactive oxygen species, thereby leading to apoptosis. Importantly, PDP-1a promotes antitumor cytokine secretion and enhances macrophage phagocytosis concentration-dependently. These findings provide a theoretical foundation for the use of O. gracilis and emphasize the potential application of PDP-1a in antitumor immunomodulatory therapy.

Desuccinylation of Inosine-5´-monophosphate Dehydrogenase 1 by SIRT5 Promotes Tumor Cell Proliferation

Inosine-5´-monophosphate dehydrogenase (IMPDH) catalyzes the rate limiting step of de novo purine synthesis. Currently, it remains still largely unknown how this metabolic event is regulated in tumor cells. Here, we report that a deacetylase sirtuin 5 (SIRT5) may possess a regulatory effect on GMP anabolism by desuccinylating IMPDH1. We found that SIRT5 can directly interacts with IMPDH1 and promotes desuccinylation on the N terminal of IMPDH1, thereby leading to increased IMPDH enzymatic activity, enhanced purine biosynthesis and promoted cell proliferation. Consistently, down-regulation of SIRT5 expression results in decreased IMPDH1 activity and impaired tumor cell proliferation. Therefore, our results reveal that SIRT5-mediated IMPDH1 desuccinylation adapts purine metabolism for rapid cell growth, and could be a potential therapeutic target for tumor cell proliferation inhibition.

Human decidua basalis mesenchymal stem/stromal cells enhance anticancer properties of human natural killer cells, in vitro.

Mesenchymal stem cells/stromal cells from the Decidua Basalis of the human placenta (DBMSCs) express wide range of effector molecules that modulate the functions of their target cells. These properties make them potential candidate for use in cellular therapy. In this study, we have investigated the consequences of interaction between DBMSCs and natural killer (NK) cells for both cell types. DBMSCs were cultured with IL-2-activated and resting non-activated NK cells isolated from healthy human peripheral blood and various functional assays were performed including, NK cell proliferation and cytolytic activities. Flow cytometry and microscopic studies were performed to examine the expression of NK cell receptors that mediate these cytolytic activities against DBMSCs. Moreover, the mechanism underlying these effects was also investigated. Our findings revealed that, co-culture of DBMSCs and NK cells resulted in inhibition of proliferation of resting NK cells, while proliferation of IL-2 activated NK cells was increased. Contrarily, treatment of DBMSC's with comparatively high numbers of IL-2 activated NK cells, resulted in their lysis, whereas treatment with low numbers resulted in reduction in their proliferation. Cytolytic activity of NK cells against DBMSCs was mediated by several activating NK cell receptors. In spite of the expression of HLA class I molecules by DBMSCs, they were still lysed by NK cells, excluding their involvement in cytolytic activity. In addition, preconditioning NK cells by DBMSCs, enhanced their ability to suppress tumor cell proliferation and in severe cases resulted in their partial lysis. Lysis and decrease of tumor cell proliferation is associated with increased expression of important molecules involved in anticancer activities. We conclude that DBMSCs exhibit dualfunctions on NK cells that enhance their anticancer therapeutic potential.

Terahertz spectroscopy study of oridonin and ponicidin in the anticancer Chinese herbal medicine Rabdosia rubescens.

Rabdosia rubescens, a Chinese herbal medicine with anticancer properties, contains two active ingredients: oridonin and ponicidin. Both compounds exhibit antitumor effects by inducing tumor cell apoptosis and autophagy and inhibiting tumor cell proliferation. To further explore the differences in molecular structure and pharmacological properties between the two substances, this study employs Terahertz Time-Domain Spectroscopy (THz-TDS) to investigate the spectral characteristics of oridonin and ponicidin in the frequency range of 0.1 to 2.3 THz. The crystal structures of the two substances are simulated using Materials Studio software and Density Functional Theory (DFT), yielding their spectra and molecular vibration modes, which elucidate the mechanism underlying the peak generation. The consistency between experimental and simulation results confirms the reliability of the experimental findings. Thus, THz spectroscopy can effectively distinguish between these two substances. Finally, a THz detection is performed on Rabdosia rubescens capsules purchased from the market, revealing the presence of absorption peaks for both substances in their absorption spectra. This provides a new approach for detecting active ingredients in Chinese herbal medicines.

The Role of Rosmarinic Acid in Cancer Prevention and Therapy: Mechanisms of Antioxidant and Anticancer Activity

Rosmarinic acid (RA), a polyphenolic compound found in herbs, such as rosemary, basil, and mint, has garnered significant attention due to its potent antioxidant and anticancer properties. This review examined the molecular mechanisms underlying these properties and their potential application in cancer prevention and therapy. It focuses specifically on RA’s role in modulating cancer-related pathways and presents a detailed analysis of recent advancements in this area. A systematic review of PubMed, Scopus, and Web of Science databases was conducted in accordance with PRISMA (Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, focusing on studies published between 2019 and 2024. A total of 25 articles providing evidence from in vitro, in vivo, and in silico studies were selected. These findings elucidate the role of RA in inhibiting tumor cell proliferation, inducing apoptosis, and preventing metastasis in various types of cancer through diverse mechanisms, including its antioxidant properties. Despite these promising results, RA’s bioavailability challenges limit its therapeutic efficacy, underscoring the necessity for improved delivery methods. This review concludes that RA exhibits significant potential as a natural agent for cancer prevention and treatment, although further clinical trials are warranted.

Anti-tumor mechanism of artesunate.

Artesunate (ART) is a classic antimalarial drug with high efficiency, low toxicity and tolerance. It has been shown to be safe and has good anti-tumor effect. Existing clinical studies have shown that the anti-tumor mechanisms of ART mainly include inducing apoptosis and autophagy of tumor cells, affecting tumor microenvironment, regulating immune response, overcoming drug resistance, as well as inhibiting tumor cell proliferation, migration, invasion, and angiogenesis. ART has been proven to fight against lung cancer, hepatocarcinoma, lymphoma, multiple myeloma, leukemia, colorectal cancer, ovarian cancer, cervical cancer, malignant melanoma, oral squamous cell carcinoma, bladder cancer, prostate cancer and other neoplasms. In this review, we highlight the effects of ART on various tumors with an emphasis on its anti-tumor mechanism, which is helpful to propose the potential research directions of ART and expand its clinical application.

4-Methyl-N-(Piperidin-1-Ylmethylene) Benzenesulfonamide (PMSA) Promotes Ferroptosis of Tumor Cells by Targeting the KEAP1-NRF2-GPX4 Axis.

We aimed to investigate the effect of 4-methyl-N-(piperidin-1-ylmethylene) benzenesulfonamide (PMSA) on tumor cell proliferation, migration, ferroptosis, and the potential molecular mechanism of ferroptosis in tumor cells. PMSA was produced in the marine biomedical research institute of Guangdong Medical University (Zhanjiang, China) and used for tumor cells treatment. MTT and cell colony formation assays were used to measure the inhibition of tumor cell proliferation, the scratch assay was used to identified the suppression of tumor cell migration, the death of tumor cells was measured by Annexin-V-FITC/PI staining, the level of ferroptosis-relative lipid ROS in tumor cells was measured by flow cytometry and MDA detection kit, and the expression of ferroptosis-relative protein was measured by Western blot. The Discovery Studio system was used for molecular docking and the binding ability was measured by cellular thermal shift assay. The PMSA we produced inhibited tumor cell proliferation, colony formation, migration and triggered cell death, and Fer-1 could reverse these effects. The amount of ROS and MDA levels in tumor cells was also markedly raised by PMSA. PMSA treatment significantly reduced the expression of SLC7A11/XCT, NRF2, and GPX4 in tumor cells. The phosphorylation level of NRF2 was also decreased. Through molecular docking, it was discovered that PMSA could bind to NRF2 and thereby block its activity. The KEAP1-NRF2-GPX4 axis was the target of PMSA's anti-tumor action, which results in ferroptosis of tumor cells. This demonstrated that the compound has the potential to be used as a candidate for anti-tumor drugs.

Engineered Exosomes with Ouabain for H3K27M‐Mutated DIPG Therapy

AbstractDiffuse intrinsic pontine glioma (DIPG) is a highly lethal tumor that occurs in the brain stem. At present, there is no effective drug for DIPG. In this work, Na/K‐ATPase inhibitor‐ouabain (OB) is found to efficiently kill H3K27M‐mutated DIPG at low doses, inhibit tumor cell proliferation, reduce tumor stemness for the first time, demonstrating its potential as a chemotherapy drug for DIPG. In order to increase the blood–brain barrier (BBB) permeability and tumor accumulation of OB, acidic‐responsive engineered exosomes loaded with OB (OB@EXO‐LCCP) are constructed, which increase the accumulation of OB within the tumor microenvironment of DIPG and efficiently deliver OB to DIPG cells to achieve targeted killing effect. In in vitro experiments, OB@EXO‐LCCP is able to release OB in an acid‐responsive manner and effectively kill DIPG tumor cells. In in vivo experiments, OB@EXO‐LCCP significantly inhibits DIPG growth and prolongs the overall survival of DIPG‐bearing mice. Overall, OB@EXO‐LCCP can promote the BBB permeability and tumor‐targeting ability of OB, thereby enhancing its DIPG‐killing ability and reducing its toxicity. This study provides technical and theoretical information for the precision therapy of DIPG.

Autophagy activator-loaded bicomponent peptide nanocarriers for phototherapy-triggered immunity enhancement against metastatic breast cancer

Mild autophagy accompanied with immunogenic cell death (ICD) effect destructs immune-associated antigens, weakening the immune response against tumor growth. To address this dilemma, we develop a peptide-based bicomponent nanocarrier with encapsulation of a cellular hyperautophagy activator (STF-62247) for near-infrared (NIR) photo/immunotherapy to eliminate primary and metastatic breast tumors. The electrostatic-driven nanodrug (PPNPs@STF) with active-targeting and efficient endosomal escape can induce specific ICD effect upon NIR laser irradiation, and trigger autophagy to a mild activation state. Notably, the simultaneously released STF-62247 precisely promotes autophagy to an overactivated state, resulting in autophagic death of tumor cells and further boosting ICD-related antigen presentation. More importantly, the combined photo/immunotherapy of PPNPs@STF not only inhibits tumor cell proliferation, but also promotes dendritic cells (DCs)-associated immune response. In 4 T1 tumor-bearing mice, PPNPs@STF effectively inhibits growth of primary and distant tumors, and suppresses lung metastasis with a minimized side effect. This study provides a hyperautophagy activator-assisted strategy that can enhance ICD-based antitumor immune response for the treatment of metastatic breast cancer.

SPOCK: Master regulator of malignant tumors (Review).

SPARC/osteonectin, CWCV and Kazal‑like domain proteoglycan (SPOCK) is a family of highly conserved multidomain proteins. In total, three such family members, SPOCK1, SPOCK2 and SPOCK3, constitute the majority of extracellular matrix glycoproteins. The SPOCK gene family has been demonstrated to serve key roles in tumor regulation by affecting MMPs, which accelerates the progression of cancer epithelial‑mesenchymal transition. In addition, they can regulate the cell cycle via overexpression, inhibit tumor cell proliferation by inactivating PI3K/AKT signaling and have been associated with numerous microRNAs that influence the expression of downstream genes. Therefore, the SPOCK gene family are potential cancer‑regulating genes. The present review summarizes the molecular structure, tissue distribution and biological function of the SPOCK family of proteins, in addition to its association with cancer. Furthermore, the present review documents the progress made in investigations into the role of SPOCK, whilst also discussing prospects for the future of SPOCK‑targeted therapy, to provide novel ideas for clinical application and treatment.

Machine learning based intratumor heterogeneity signature for predicting prognosis and immunotherapy benefit in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is a prevalent malignancy that is highly aggressive and heterogeneous. Intratumor heterogeneity (ITH) showed strong link to tumor progression and metastasis. High ITH may promote tumor evolution. An ITH-related signature (IRS) was created using as integrative technique including 10 machine learning methods based on TCGA, GSE15459, GSE26253, GSE62254 and GSE84437 datasets. The relevance of IRS in predicting the advantages of immunotherapy was assessed using a number of prediction scores and three immunotherapy datasets (GSE78220, IMvigor210 and GSE91061). Vitro experiments were performed to verify the biological functions of AKR1B1. The RSF + Enet (alpha = 0.1) projected model was proposed as the ideal IRS because it had the highest average C-index. The IRS demonstrated a strong performance in serving as an independent risk factor for the clinical outcome of STAD patients. It performed exceptionally well in predicting the overall survival rate of STAD patients, as seen by the TCGA cohort’s AUC of 1-, 3-, and 5-year ROC curves, which were 0.689, 0.683, and 0.669, respectively. A low IRS score demonstrated a superior response to immunotherapy, as seen by a lower TIDE score, lower immune escape score, greater TMB score, higher PD1&CTLA4 immunophenoscore, higher response rate, and improved prognosis. Common chemotherapeutic and targeted treatment regimens had lower IC50 values in the group with higher IRS scores. Vitro experiment showed that AKR1B1 was upregulated in STAD and knockdown of AKR1B1 obviously suppressed tumor cell proliferation and migration. The present investigation produced the best IRS for STAD, which may be applied to prognostication, risk stratification, and therapy planning for STAD patients.

8801 Towards Safe and Efficacious Medical Therapy for Patients with Clinically Non-Functioning Pituitary Tumors

Abstract Disclosure: D. Zhang: None. M. Bergsneider: None. W. Kim: None. M.B. Wang: None. H. Vinters: None. A.P. Heaney: None. Clinically non-functioning pituitary tumors (CNFTs) account for one-third of all pituitary adenomas. They do not cause clinical and/or biochemical evidence of tumor-related hormone hypersecretion, grow insidiously and typically present with mass effect symptoms such as headache and visual field deficits. Surgical resection is the current standard of care for CNFTs but complete resection is infrequently achieved due to their size and invariable invasion of locally adjacent structures. CNFT remnant tumor regrowth rates approach 50% and these patients may need repeat surgery and/or radiotherapy (RT). The latter is quite effective in achieving tumor control, but carries a risk of hypopituitarism of ∼ 40% at 10 years. Although dopamine agonists and somatostatin receptor ligands have been explored as medical therapy, there are currently no consistently effective medical treatments for CNFTs. There is a clear unmet need for novel safe and effective medical therapies for these comparatively common tumors. In a highly innovative approach we have used patient-derived ex vivo 3D tumoroid human CNFTs in an automated high throughput compound screen (HTS) to identify novel tumoricidal and growth inhibitory compounds for CNFTs. To date, we have screened ∼4,000 compounds and have identified 13 potential hits that inhibited tumor cell proliferation (a reduction of 76±15%) and induced apoptosis (induction rate of 8.2 ± 6.6) in the CNFT tumoroids respectively. The hit compounds to date fall into 3 categories based on their targets, namely Na+/K+-ATPase inhibitors (n=6), reactive oxygen species (ROS) regulators (n=4), and cell cycle inhibitors (n=3). Representative “hit” compounds from each group identified in our primary screen were rescreened in triplicate in 20 concentrations from 25µM to 50pM at 2-fold dilutions. Dose-response curves characterized compound doses that inhibited cell viability by 50% (IC50) and ranged from 13nM to 103nM. Two of these 3 compounds also induced 2-3-fold apoptosis at 0.1uM with the final compound displaying a potent 5-10-fold pro-apoptotic effect at 0.15uM concentration. In parallel, we used single cell RNA sequencing to validate targets that emerged from our HTS and to characterize the mechanism of action (MOA) of these hit compounds. As proof of concept, several of the known drug targets were noted to be amongst the highest differentially expressed genes in the CNFT tumor cell population. This approach validating a candidate target in conjunction with demonstrable activity of a drug for that same target in CNFTs may simultaneously provide us with a back-bone molecule to further develop with structural activity relationship analysis and/or allow us to individualize drug choice in patients based on immunocytochemical tumor target expression. Presentation: 6/1/2024