Treatment Of Adrenocortical Carcinoma Research Articles

7652 Functional Adrenocortical Carcinoma Presenting As Uncontrolled Hypertension

Abstract Disclosure: B.R. Bedell: None. M. Fariduddin: None. J. Sanchez Perez: None. S.C. Kukreja: None. R.M. Sargis: None. Adrenocortical carcinoma is a rare malignancy, with approximately 2,000 cases reported in the United States since 1970.[1] Many secrete excess adrenocortical hormones, adding to morbidity and mortality. Surgery can be curative or prolong survival if diagnosis is made early, but prognosis remains poor due to delayed detection.[2] We present a case of metastatic functional adrenocortical carcinoma that presented with consequences of long-standing uncontrolled hypertension. A 59-year-old male with history of hypertension and CAD presented to the hospital with worsening bilateral pitting edema, dyspnea on exertion, palpitations, headaches, and proximal muscle weakness over for multiple months. His hypertension (HTN) was noted to be uncontrolled despite use of multiple antihypertensives (daily Lasix 20 mg, Lisinopril 40 mg, Metoprolol Succinate 100 mg and Amlodipine 10 mg). Hypokalemia of 3.0 mmol/l (3.5 - 5.2 mmol/l) was noted. Echocardiogram revealed new heart failure with preserved ejection fraction. A subsequent nuclear stress test incidentally revealed a right-sided 15 cm retroperitoneal mass, invading the IVC and the right hepatic lobe. An AM dexamethasone suppression test was notable for a cortisol of 39 ug/dl (<1.8 ug/dl) and an undetectable ACTH level of <1.5 pg/ml (7.2 - 63.3 pg/mL), suggestive of primary hypercortisolism. 24-hour urine cortisol was 930.6 ug/d, (<=60.0 ug/d), DHEA-s 1105 ug/dL (52 - 295 ug/dL), Androstenedione 2.641ng/mL (0.230 - 0.890 ng/mL), and 17-Hydroxyprogesterone 299.87 ng/dL (<=138.00 ng/dL). Plasma metanephrines were normal and aldosterone levels were undetectable, confirming cortisol and its precursor excess as the cause of hypertension. Biopsy of the mass was consistent with adrenocortical carcinoma. Due to disease extent, the patient was not a candidate for surgical debulking, and radiation therapy was commenced. Ketoconazole 200 mg and Spironolactone 150 mg twice daily led to improvement in HTN and hypokalemia. His course was further complicated by bacteremia and acute pulmonary embolism. The patient eventually elected to pursue hospice care. Adrenocortical carcinoma remains challenging to detect at early stages given a paucity of symptoms. This case highlights the need to have a high index of suspicion for hypercortisolism in patients with uncontrolled HTN and hypokalemia, as this may be indicative of a functional adrenal cancer. This could be a potential strategy for earlier diagnosis, thereby increasing survival rates by improving disease amenability to surgical intervention. (1.) Sharma E, Dahal S, Sharma P, et al. The Characteristics and Trends in Adrenocortical Carcinoma: A United States Population Based Study. J Clin Med Res. 2018;10(8):636-640. doi:10.14740/jocmr3503w (2.) Vaidya A, Nehs M, Kilbridge K. Treatment of Adrenocortical Carcinoma. Surg Pathol Clin. 2019;12(4):997-1006. doi:10.1016/j.path.2019.08.010 Presentation: 6/2/2024

7427 Cellular Senescence As A Pro-Tumorigenic Process And Therapeutic Target In Adrenocortical Carcinoma

Abstract Disclosure: L. Smith: None. K. Warde: None. S. Haston: None. J. Martinez-Barbera: None. K. Basham: None. Adrenocortical carcinoma (ACC) is a rare, yet highly aggressive malignancy that arises in the adrenal cortex. Advanced age is a major risk factor for ACC, with the peak age incidence between 50 and 60 years old. Older individuals above age 50 also have significantly worse survival outcomes. A better understanding of how aging contributes to the development and progression of ACC will uncover new treatment strategies. A major hallmark of aging is the systemic accumulation of senescent cells. While senescent cells have been implicated in various age-related diseases, including cancer, their role in ACC remains poorly understood. ACC tumors from older patients have an enrichment of senescence-associated gene signatures. Moreover, advanced ACC patients are treated with etoposide, doxorubicin, and cisplatin (EDP), which are chemotherapies that induce senescence. While EDP offers short-term benefit in some patients, more than half will progress within 6-months. We hypothesize that the accumulation of senescent cells that arise after EDP treatment are ultimately tumor-supportive long-term. As a result, we postulate that the use of senolytic compounds that clear away senescent cells after EDP treatment will lead to improved survival outcomes for ACC patients. We developed a new ACC mouse model that provides a window to study the role of senescence in ACC tumor progression and treatment. Our model is based on adrenal specific loss of ZNRF3, which is a Wnt inhibitor that is frequently inactivated in human ACC tumors. Despite early adrenal hyperplasia, we showed that Znrf3 conditional knockout (cKO) mice do not develop adrenal tumors until 18-months of age, which corresponds to the peak age incidence in humans. Additionally, the adrenals of Znrf3 cKO mice show a robust senescence activation phenotype that precedes adrenal tumorigenesis. We hypothesize that the accumulation of senescent cells is pro-tumorigenic long-term. To test our hypothesis, we combined Znrf3 cKO mice with a newly established mouse model that enables selective ablation of senescent cells (ZKO-FDR mice). Ongoing aging studies will determine whether the removal of early and late senescent cells in ZKO-FDR mice reduces adrenal tumorigenesis. Further, we established new primary tumor cell lines from aged ZKO-FDR mice. These cell lines will facilitate testing of the pro-tumor mechanisms of senescence. Additionally, they will permit the removal of senescent cells, both genetically and pharmacologically with senolytics, as a new treatment strategy in ACC. Overall, this project aims to investigate the pro-tumor biology of age- and therapy-induced senescence in ACC. Results from these studies will advance our understanding of senescence in cancer and aid in the development of new therapeutic strategies for ACC, including senolytics. Presentation: 6/2/2024

7888 Mitotane Induces Different Modes Of Cell Death In Treatment Resistant And Sensitive Models Of Adrenocortical Carcinoma

Abstract Disclosure: S. Feely: None. N. Mullen: None. C. Hong: None. C. Hantel: None. W.E. Rainey: None. M.C. Dennedy: None. Adrenocortical carcinoma (ACC) is a rare aggressive cancer with poor survival. Adjuvant mitotane is the only approved drug for treatment of ACC. It improves survival but its use is limited by poor tolerability and drug resistance. For metastatic ACC, combination chemotherapy, using mitotane and etoposide, doxorubicin, and cisplatin improves survival, but efficacy is limited. Better understating the cytotoxic mechanisms of mitotane offers potential to develop improved therapeutic options for ACC. To investigate the underlying mechanisms in vitro, human ACC cells (HAC15 and H295R), in monolayer cell culture were treated with increasing concentrations of mitotane. Cell death was evaluated at 6 and 24 hours using flow cytometry analysis of Annexin V and Sytox Blue. This was complemented by Incucyte ® Live-Cell Analysis System imaging of annexin V and Sytox Blue staining. Expression of the markers of apoptosis, cleaved caspase 3, and necroptosis, phosphorylated MLKL and RIPK1 was measured at 6 and 24 hours. Mitotane significantly reduced the viability of H295R cells at 6 and 24 hours at the therapeutic concentration of 50uM (p>0.0001), thereby demonstrating treatment-sensitivity. In HAC15 cells, a supratherapeutic dose of 200uM was needed to significantly reduce viability (p>0.05) at 24 hours, indicating resistance to mitotane treatment at therapeutic concentrations. There was increasing Annexin V fluorescence with increasing mitotane concentration in H295R and HAC15 cells ar 6 and 24 hours without higher coinciding staining with Sytox Blue. Video analysis demonstrated these findings. Cleaved caspase 3 expression was associated with mitotane-induced cell death in H295R cells at 6 and 24 hours, indicating apoptosis. HAC15 cells demonstrated cleaved caspase 3 expression only at the highest concentration of mitotane exposure (600uM) at 6 hours, without appreciable expression at 24 hours. Phosphorylated-MLKL and RIPK1 expression was seen in controls and all mitotane doses in both cell lines at both timepoints, indicating necroptosis. In this study, H295R cells, representing a treatment-sensitive model of Mitotane undergo both apoptotic and necroptotic cell death at 6 and 24 hours of mitotane exposure. In contrast, HAC15 cells, demonstrated relative treatment resistance to mitotane, and undergo necroptotic cell death only. These results highlight the importance of understanding and targeting non-apoptotic and necroptotic cell death pathways, particularly when evaluating mechanisms of treatment resistance in ACC. Given the difference in the mechanism of cell death in treatment-sensitive and treatment-resistant cells, further exploration of necroptosis is necessary to better understand how ACC cells may manifest treatment resistance. Presentation: 6/1/2024

The impact of acyl-CoA:cholesterol transferase (ACAT) inhibitors on biophysical membrane properties depends on membrane lipid composition

Acyl-coenzyme A: cholesterol acyltransferases are enzymes which are involved in the homeostasis of cholesterol. Impaired enzyme activity is associated with the occurrence of various diseases like Alzheimer’s disease, atherosclerosis, and cancers. At present, mitotane is the only inhibitor of this class of enzymes in clinical use for the treatment of adrenocortical carcinoma but associated with common and severe adverse effects. The therapeutic effect of mitotane depends on its interaction with cellular membranes. The search for less toxic but equally effective compounds is hampered by an incomplete understanding of these biophysical properties. In the present study, the interaction of the three ACAT inhibitors nevanimibe, Sandoz 58-035, and AZD 3988 with membranes has been investigated using lipid model membranes in conjunction with biophysical experimental (NMR, ESR, fluorescence) and theoretical (MD simulations) approaches. The data show, that the drugs (i) incorporate into lipid membranes, (ii) differently influence the structure of lipid membranes; (iii) affect membrane structure depending on the lipid composition; and (iv) do not cause hemolysis of red blood cells. The results are discussed with regard to the use of the drugs, in particular to better understand their efficacy and possible side effects.

Novel repurposing of sulfasalazine for the treatment of adrenocortical carcinomas, probably through the SLC7A11/xCT-hsa-miR-92a-3p-OIP5-AS1 network pathway

BackgroundRecent multigenomic analysis of adrenocortical carcinomas (ACCs) identified SLC7A11/xCT as a novel biomarker. The Food and Drug Administration–approved anti-inflammatory drug, sulfasalazine (SAS), induces ferroptosis by blocking SLC7A11 expression. We hypothesize that SAS could be repurposed to target ACC cells. MethodsExpression of SLC7A11 and its association with ACC survival was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA). The validated ACC cell lines NCI-H295R, ACC1, and ACC2 were grown in 2D culture. In vitro studies included the CellTiter-Glo assay to calculate viability, Western blot (WB) analysis for apoptosis and other target protein changes, reverse transcriptase polymerase chain reaction for steroidogenic enzyme changes, C11BODIPY for lipid peroxidation, and mass spectrometry for changes in lipids. ResultsThe Cancer Genome Atlas Program database analysis in GEPIA showed that SLC7A11 and linked long noncoding RNA OAP5-AS1 are highly expressed in ACC tumors versus normal adrenals (n = 77 vs 128; P < .05). This was associated with poor overall and disease-free survival with hazard ratios of 4.3 and 5.2 for SLC7A11 and 4.8 and 2.7 for OAP5-AS1, respectively. ACC cell line half-inhibitory maximum concentration values after 72-hour SAS treatment ranged from 412 nM (ACC1) to 799 nM (ACC2), and all showed cleavage of poly (ADP-ribose) polymerase, upregulation of p-Akt and p-ERK, and downregulation of GPX4 and SLC7A11 (P < .05) by WB analysis. Sphere formation, migration, and invasion assay showed inhibition, and lipid peroxidation using C11BODIPY, increase in intracellular iron, induction of oxidative stress, and significant upregulation of oxidized polyunsaturated fatty acid phospholipids (P < .05 each) by mass spectrometry suggests induction of ferroptosis. ConclusionSAS downregulates tSLC7A11 in ACCs, targets the Akt/ERK pathway and lipid metabolism, and induces cell death in vitro, warranting additional translational studies to define its therapeutic potential in ACC.

Demystifying Delays: Factors Associated with Timely Treatment of Adrenocortical Carcinoma

Demystifying Delays: Factors Associated with Timely Treatment of Adrenocortical Carcinoma

Adverse Events of Adjuvant Mitotane Treatment for Adrenocortical Carcinoma

ABSTRACT Background Mitotane is the cornerstone of adjuvant adrenocortical cancer (ACC) treatment. However, its use is burdened with frequent adverse events. Methods A retrospective analysis of adverse events was performed in 26 ACC patients adjuvantly treated with mitotane. Results Mitotane toxicity was present in all patients (100%). Two (7.7%) patients developed 1–3 adverse events, 15 (57.7%) experienced 4–6 adverse events and 9 (34.6%) patients had more than 6 adverse events. Two (7.7%) patients discontinued mitotane due to adverse events. Conclusion Careful monitoring and timely management are essential for ensuring mitotane treatment adherence and maximizing its benefits.

A review of mitotane in the management of adrenocortical cancer.

Mitotane (Lysodren, o,p'-DDD [1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane)] is currently the only United States Food and Drug Administration and European Medicines Agency-approved product for the treatment of adrenocortical carcinoma. Mitotane is challenging to administer; however, its toxicities (specifically adrenal insufficiency) are well known, and the management of adverse consequences has established approaches. While often viewed through the prism of a cytotoxic agent, it can also interfere with hormone production making it a valuable asset in managing functional ACC. A recently completed prospective trial has shed some light on its use in the adjuvant setting, but further clarity is needed. Many think mitotane has a role in the advanced or metastatic setting, although prospective data are lacking and retrospective analyses are often difficult to interpret. When used carefully and thoughtfully, especially in patients with hormonal excess, mitotane is an important component of the treatment armamentarium for ACC.

Adrenal tumors: current standards in clinical management

Adrenal tumors are among the most common tumors in humans. They are most frequently discovered incidentally during abdominal imaging for other reasons or due to clinical symptoms (e.g. Conn's or Cushing's syndrome, pheochromocytoma or androgen excess). Although over 80% of adrenal tumors are benign, in cases of hormone excess, they are associated with significantly increased morbidity. In highly malignant adrenocortical carcinoma (ACC), early diagnosis is of particular prognostic relevance. Therefore, this review presents the diagnostic procedure for what are referred to as adrenal incidentalomas and provide recommendations for the management of ACC and pheochromocytomas/paragangliomas (PPGL). In primary diagnosis, sufficient hormone diagnostics is required for all adrenal tumors, as this is the only way to identify all patients with relevant hormone excess. Imaging has increasingly improved in recent years and allows areliable assessment of the tumor's malignancy in most cases. Imaging of first choice is unenhanced computed tomography (CT), while magnetic resonance imaging (MRI) and fluorodeoxyglucose-18 positron emission tomography (FDG-PET/CT) are reserved for special situations, as published evidence on these procedures is more limited. The treatment of ACC and PPGL is complex and is carried out on an interdisciplinary basis at specialized centers. In the case of localized disease, surgery is the only curative treatment option. There are now clear recommendations for individualized adjuvant therapy for ACC. In metastatic disease, mitotane with or without platinum-containing chemotherapy is the standard. Other lines of therapy should be discussed with areference center. Over 35% of PPGL have agermline mutation; therefore, genetic testing should be offered. In metastatic PPGL, an individual decision is required between active surveillance, radionuclide therapy, sunitinib or chemotherapy.

Knock out of ELAVL1 affects steroid synthesis in adrenocortical carcinoma cell line NCI-H295R and leads to a less malignant phenotype

Introduction: Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal gland. With a 5-year-survival rate below 50% and no curative treatment options in advanced stages new therapeutic options in ACC are needed. Analyzing the ACC cohort of the cancer genome atlas we found a significant negative correlation of the expression level of a gene called Embryonic Lethal Abnormal Vision Like 1 (ELAVL1) and ACC patient survival. ELAVL1 has been described to be unfavorable in a lot of different tumor entities, but its function in ACC progression is still unknown. Methods: To evaluate the function of ELAVL1 in ACC progression we performed a CRISPR/Cas9 mediated knock out (KO) of the ELAVL1 gene in the ACC cell line NCI-H295R. The KO was confirmed on DNA level via Sanger sequencing and on protein level via immunofluorescence and western blot. Transcriptome changes were analyzed by next generation RNA sequencing (NGS). To characterize changes in cell function we performed soft agar colony forming assays and evaluated changes in steroid production via mass spectrometry. Results: Via CRISPR/Cas9 we knocked out ELAVL1 in NCI-H295R cells. NGS data showed 6926 significantly deregulated genes in ELAVL1-KO cells compared to control cells. There was an upregulation of 3468 genes, while 3458 genes showed a lower expression in ELAVL1 KO cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed a significant upregulation of 29 genes associated with aldosterone synthesis and a significant downregulation of 87 genes associated with pathways in cancer. Analyzing cell function via soft agar colony forming assays an impaired colony forming ability in ELAVL1 KO cells was seen. Furthermore, we could prove significant changes in steroid production. ELAVL1 KO led to an inhibition of androgen and glucocorticoid synthesis and an enhancement in mineralocorticoid synthesis. These changes could not only be proven by measuring steroid concentrations in cell culture supernatants, but also by NGS showing a downregulation of the genes CYP17A1 and CYP11B1 and an upregulation of CYP21A2 and CYP11B2. Conclusion: Our study showed that ELAVL1 affects the regulation of around 7000 genes in the ACC cell line NCI-H295R. Especially the inhibition of glucocorticoid synthesis shows that ELAVL1 may be a new target for therapeutic approaches in ACC treatment since hypercortisolism is one of the main symptoms in ACC and a negative prognostic factor for patient survival. The authors have nothing to disclose. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Clinicopathological characteristics of adrenocortical carcinoma in the Kyushu-Okinawa area of Japan.

Adrenocortical carcinoma is a rare condition, with limited comprehensive reports from Japan. This study aimed to review Japan's data on adrenocortical carcinoma by assessing information from 46 patients-with adrenocortical carcinoma across 10 Japanese university hospitals. We conducted a retrospective multi-institutional analysis of the clinical characteristics of adrenocortical carcinoma in Japan. We evaluated data from 46 patients across 10 university hospitals over 10 years and analyzed the relationship between clinicopathological characteristics and overall survival. Five- and 10-year overall survival rates were 59% and 53%, respectively. Overall survival was significantly different among the tumor-node-metastasis system for adrenocortical carcinoma of the American Joint Committee on Cancer/International Union Against Cancer, with the worst prognosis in stage IV (p = 0.0044). In our cohort, neither the Weiss score nor the Ki-67 proliferation index correlated with overall survival. Adjuvant treatment did not yield improved overall survival, whereas resection of the primary tumor in stage IV disease was significantly associated with improved overall survival (p = 0.0262). Out of the cases evaluated for plasma hormones, plasma cortisol, aldosterone, testosterone, and DHEA-S levels were measured at 23%, 42%, 29%, and 62%, respectively, demonstrating higher levels than the upper normal limits. Patients with stage IV adrenocortical carcinoma had a poor prognosis; however, resection of the primary tumor in stage IV disease was associated with prolonged survival. The results of this study are expected to contribute to future treatment of adrenocortical carcinoma in Japan.

Wnt/β-catenin signaling pathway in the tumor progression of adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is an uncommon, aggressive endocrine malignancy with a high rate of recurrence, a poor prognosis, and a propensity for metastasis. Currently, only mitotane has received certification from both the US Food and Drug Administration (FDA) and the European Medicines Agency for the therapy of advanced ACC. However, treatment in the advanced periods of the disorders is ineffective and has serious adverse consequences. Completely surgical excision is the only cure but has failed to effectively improve the survival of advanced patients. The aberrantly activated Wnt/β-catenin pathway is one of the catalysts for adrenocortical carcinogenesis. Research has concentrated on identifying methods that can prevent the stimulation of the Wnt/β-catenin pathway and are safe and advantageous for patients in view of the absence of effective treatments and the frequent alteration of the Wnt/β-catenin pathway in ACC. Comprehending the complex connection between the development of ACC and Wnt/β-catenin signaling is essential for accurate pharmacological targets. In this review, we summarize the potential targets between adrenocortical carcinoma and the Wnt/β-catenin signaling pathway. We analyze the relevant targets of drugs or inhibitors that act on the Wnt pathway. Finally, we provide new insights into how drugs or inhibitors may improve the treatment of ACC.

Polish diagnostic and therapeutic recommendations for adrenocortical carcinoma.

Advances in the diagnosis and treatment of adrenocortical carcinoma (ACC), along with the development of new therapeutic and diagnostic methods, have prompted a team of experts to formulate the first Polish guidelines for managing ACC. This article presents the diagnostic and therapeutic recommendations resulting from the discussion of specialists from various medical specialities, who participated in a series of online meetings aimed at developing consistent and effective recommendations under the National Oncology Strategy. These guidelines aim to optimise ACC treatment in Poland through coordinated efforts of multidisciplinary specialist teams, ensuring an effective and modern approach.

Identification of Key Genes and Related Drugs of Adrenocortical Carcinoma by Integrated Bioinformatics Analysis.

Adrenocortical carcinoma (ACC) is a malignant carcinoma with an extremely poor prognosis, and its pathogenesis remains to be understood to date, necessitating further investigation. This study aims to discover biomarkers and potential therapeutic agents for ACC through bioinformatics, enhancing clinical diagnosis and treatment strategies. Differentially expressed genes (DEGs) between ACC and normal adrenal cortex were screened out from the GSE19750 and GSE90713 datasets available in the GEO database. An online Venn diagram tool was utilized to identify the common DEGs between the two datasets. The identified DEGs were subjected to functional assessment, pathway enrichment, and identification of hub genes by performing the protein-protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The differences in the expressions of hub genes between ACC and normal adrenal cortex were validated at the GEPIA2 website, and the association of these genes with the overall patient survival was also assessed. Finally, on the QuartataWeb website, drugs related to the identified hub genes were determined. A total of 114 DEGs, 10 hub genes, and 69 known drugs that could interact with these genes were identified. The GO and KEGG analyses revealed a close association of the identified DEGs with cellular signal transduction. The 10 hub genes identified were overexpressed in ACC, in addition to being significantly associated with adverse prognosis in ACC. Three genes and the associated known drugs were identified as potential targets for ACC treatment.

Laparoscopic surgery for adrenocortical carcinoma: Estimating the risk of margin-positive resection.

Over recent years, there has been increasing adoption of minimally invasive surgery (MIS) in the treatment of adrenocortical carcinoma (ACC). However, MIS has been associated with noncurative resection and locoregional recurrence. We aimed to identify risk factors for margin-positivity among patients who undergo MIS resection for ACC. We hypothesized that a simple nomogram can accurately identify patients most suitable for curative MIS resection. Curative-intent resections for ACC were identified through the National Cancer Database spanning 2010-2018. Trends in MIS utilization were reported using Pearson correlation coefficients. Factors associated with margin-positive resection were identified among preoperatively available variables using multivariable logistic regression, then incorporated into a predictive model. Model quality was cross validated using an 80% training data set and 20% test data set. Among 1260 ACC cases, 38.6% (486) underwent MIS resection. MIS utilization increased over time at nonacademic centers (R = 0.818, p = 0.007), but not at academic centers (R = 0.009, p = 0.982). Factors associated with margin-positive MIS resection were increasing age, nonacademic center (odds ratio [OR]: 1.8, p = 0.006), cT3 (OR: 4.7, p < 0.001) or cT4 tumors (OR: 14.6, p < 0.001), and right-sided tumors (OR: 2.0, p = 0.006). A predictive model incorporating these four factors produced favorable c-statistics of 0.75 in the training data set and 0.72 in the test data set. A pragmatic nomogram was created to enable bedside risk stratification. An increasing proportion of ACC are resected via minimally invasive operations, particularly at nonacademic centers. Patient selection based on a few key factors can minimize the risk of noncurative surgery.

Albumin/Mitotane Interaction Affects Drug Activity in Adrenocortical Carcinoma Cells: Smoke and Mirrors on Mitotane Effect with Possible Implications for Patients' Management.

Mitotane is the only drug approved for the treatment of adrenocortical carcinoma (ACC). Although it has been used for many years, its mechanism of action remains elusive. H295R cells are, in ACC, an essential tool to evaluate drug mechanisms, although they often lead to conflicting results. Using different in vitro biomolecular technologies and biochemical/biophysical experiments, we evaluated how the presence of "confounding factors" in culture media and patient sera could reduce the pharmacological effect of mitotane and its metabolites. We discovered that albumin, the most abundant protein in the blood, was able to bind mitotane. This interaction altered the effect of the drug by blocking its biological activity. This blocking effect was independent of the albumin source or methodology used and altered the assessment of drug sensitivity of the cell lines. In conclusion, we have for the first time demonstrated that albumin does not only act as an inert drug carrier when mitotane or its metabolites are present. Indeed, our experiments clearly indicated that both albumin and human serum were able to suppress the pharmacological effect of mitotane in vitro. These experiments could represent a first step towards the individualization of mitotane treatment in this rare tumor.

PLK1 inhibitors as a new targeted treatment for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is an aggressive malignancy with limited treatment options. Polo-like kinase 1 (PLK1) is a promising drug target; PLK1 inhibitors (PLK1i) have been investigated in solid cancers and are more effective in TP53-mutated cases. We evaluated PLK1 expression in ACC samples and the efficacy of two PLK1i in ACC cell lines with different genetic backgrounds. PLK1 protein expression was investigated by immunohistochemistry in tissue samples and correlated with clinical data. The efficacy of rigosertib (RGS), targeting RAS/PI3K, CDKs and PLKs, and poloxin (Pol), specifically targeting the PLK1 polo-box domain, was tested in TP53-mutated NCI-H295R, MUC-1, and CU-ACC2 cells and in TP53 wild-type CU-ACC1. Effects on proliferation, apoptosis, and viability were determined. PLK1 immunostaining was stronger in TP53-mutated ACC samples vs wild-type (P = 0.0017). High PLK1 expression together with TP53 mutations correlated with shorter progression-free survival (P= 0.041). NCI-H295R showed a time- and dose-dependent reduction in proliferation with both PLK1i (P< 0.05at 100 nM RGS and 30 µM Pol). In MUC-1, a less pronounced decrease was observed (P< 0.05at 1000 nM RGS and 100 µM Pol). 100 nM RGS increased apoptosis in NCI-H295R (P< 0.001), with no effect on MUC-1. CU-ACC2 apoptosis was induced only at high concentrations (P < 0.05 at 3000 nM RGS and 100 µM Pol), while proliferation decreased at 1000 nM RGS and 30 µM Pol. CU-ACC1 proliferation reduced, and apoptosis increased, only at 100 µM Pol. TP53-mutated ACC cell lines demonstrated better response to PLK1i than wild-type CU-ACC1. These data suggest PLK1i may be a promising targeted treatment of a subset of ACC patients, pre-selected according to tumour genetic signature.

Exploring the role of the disulfidptosis-related gene SLC7A11 in adrenocortical carcinoma: implications for prognosis, immune infiltration, and therapeutic strategies

BackgroundDisulfidptosis and the disulfidptosis-related gene SLC7A11 have recently attracted significant attention for their role in tumorigenesis and tumour management. However, its association with adrenocortical carcinoma (ACC) is rarely discussed.MethodsDifferential analysis, Cox regression analysis, and survival analysis were used to screen for the hub gene SLC7A11 in the TCGA and GTEx databases and disulfidptosis-related gene sets. Then, we performed an association analysis between SLC7A11 and clinically relevant factors in ACC patients. Univariate and multivariate Cox regression analyses were performed to evaluate the prognostic value of SLC7A11 and clinically relevant factors. Weighted gene coexpression analysis was used to find genes associated with SLC7A11. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses and the LinkedOmics database were used to analyse the functions of SLC7A11-associated genes. The CIBERSORT and Xcell algorithms were used to analyse the relationship between SLC7A11 and immune cell infiltration in ACC. The TISIDB database was applied to search for the correlation between SLC7A11 expression and immune chemokines. In addition, we performed a correlation analysis for SLC7A11 expression and tumour mutational burden and immune checkpoint-related genes and assessed drug sensitivity based on SLC7A11 expression. Immunohistochemistry and RT‒qPCR were used to validate the upregulation of SLC7A11 in the ACC.ResultsSLC7A11 is highly expressed in multiple urological tumours, including ACC. SLC7A11 expression is strongly associated with clinically relevant factors (M-stage and MYL6 expression) in ACC. SLC7A11 and the constructed nomogram can accurately predict ACC patient outcomes. The functions of SLC7A11 and its closely related genes are tightly associated with the occurrence of disulfidptosis in ACC. SLC7A11 expression was tightly associated with various immune cell infiltration disorders in the ACC tumour microenvironment (TME). It was positively correlated with the expression of immune chemokines (CXCL8, CXCL3, and CCL20) and negatively correlated with the expression of immune chemokines (CXCL17 and CCL14). SLC7A11 expression was positively associated with the expression of immune checkpoint genes (NRP1, TNFSF4, TNFRSF9, and CD276) and tumour mutation burden. The expression level of SLC7A11 in ACC patients is closely associated withcthe drug sensitivity.ConclusionIn ACC, high expression of SLC7A11 is associated with migration, invasion, drug sensitivity, immune infiltration disorders, and poor prognosis, and its induction of disulfidptosis is a promising target for the treatment of ACC.

Pediatric adrenocortical carcinoma: clinical features and application of neoadjuvant chemotherapy

ObjectiveTo summarize the clinical characteristics of children with adrenocortical carcinoma (ACC) and preliminarily explore the indications for and efficacy of neoadjuvant chemotherapy in certain patients.MethodsThe data of 49 children with adrenocortical tumors (ACT) in the past 15 years were retrospectively analyzed, and after pathology assessment using Weiss system grading, 40 children diagnosed with ACC were included. Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and three-dimensional (3D) reconstruction of contrast-enhanced computed tomography data were used to evaluate the response to neoadjuvant chemotherapy.ResultsForty patients (17 males, 23 females) with ACC were enrolled. Abnormal hormone levels were common in children with ACC (n = 31), and in terms of clinical presentation, sexual precocity was the most common (n = 14, 35.0%), followed by Cushing’s syndrome (n = 12, 30.0%). Seven of 40 children received neoadjuvant chemotherapy due to a maximum lesion diameter greater than 10 cm (n = 4), invasion of surrounding tissues (n = 2), intravenous tumor thrombus (n = 2), and/or distant metastasis (n = 2); 2 patients achieved partial response, and 5 had stable disease according to the RECIST 1.1 standard. Furthermore, 3D tumor volume reconstruction was performed in 5 children before and after neoadjuvant chemotherapy. Tumor volumes were significantly reduced in all 5 children, with a median volume reduction of 270 (interquartile range, IQR 83, 293) (range: 49–413) ml. After surgery with/without chemotherapy, the 5-year overall survival rate for all children was 90.0% (95% CI-confidence interval 80.0–100.0%), and the 5-year event-free survival rate was 81.5% (95% CI 68.0–97.7%).ConclusionIn the diagnosis and treatment of pediatric ACC, a comprehensive endocrine evaluation is necessary to facilitate early diagnosis. Surgery and chemotherapy are important components of ACC treatment, and neoadjuvant chemotherapy should be considered for children with ACC who meet certain criteria, such as a large tumor, distant metastases, or poor general condition.

THU609 Timeline For Undetectable Mitotane Plasma Levels In Adrenocortical Carcinoma Patients After Stopping Treatment

Abstract Disclosure: N. Younes: None. P. Hétu: None. A. Lacroix: None. I. Bourdeau: None. Background: Mitotane (o,p’DDD) is an adrenolytic steroidogenesis inhibitor recommended in the treatment of adrenocortical carcinoma (ACC) with a high risk of recurrence. Mitotane has a long plasma elimination half-life, because of its highly lipophilic properties. Objectives: To further explore time to reach undetectable mitotane plasma levels (UM) in treated ACC patients after stopping the medication. Methods: We retrospectively analyzed the medical files of 13 adult patients with ACC who were treated with mitotane during at least 24 months, between 2006 and 2020, in our center. We calculated the duration in months for plasma concentrations of mitotane to be undetectable, from the time of cessation of mitotane in all 13 patients. Baseline demographic characteristics of patients and baseline tumor characteristics were recorded, along with the maximal dose of mitotane used. We also explored the time it took patients to be able to stop glucocorticoid and/or mineralocorticoid replacement therapy following mitotane cessation. Results: The mean age at diagnosis of ACC was 48.2 ± 14.9 years and 69.2% of patients were female. Patients weighted 78.2 ± 27.2 Kg. The mean tumor size and proliferation index Ki67 were 8.1 ± 4.3 cm and 13.3 ± 7.3%. None of the patients had metastasis at diagnosis. They were treated with a mean of 4 ± 2 g of mitotane daily, for 33.5 ± 9 months. Only one patient never had documented therapeutic mitotane range (between 14 and 20 mg/L) during treatment. The time to UM from the time of mitotane cessation was 13.2 ± 7.1 months. All 13 patients were taking glucocorticoid replacement therapy and 5 were able to completely withdraw hydrocortisone 39 ± 14.5 months after stopping mitotane treatment. Only 2 patients out of the 6 patients that were on mineralocorticoid replacement therapy, were able to stop after 34.2 and 59.7 months, respectively. There was no significant relationship found between the duration of exposure to mitotane and the time to UM (p=0.82). On simple linear regression, patients’ weight explained 80% of variance of time to UM. There was a positive relationship between patients’ weight and time to UM (standardized coefficient beta 0.89, p &amp;lt;0.0001). On multiple linear regression, patients’ weight was an independent predictor of time to UM. Conclusion: Mitotane can take up to 13 months to become undetectable in patients’ plasma after cessation. In our cohort, it is mainly influenced by increased weight but not by duration of exposure to the drug. Presentation: Thursday, June 15, 2023