Somatic SLC30A1 mutations altering zinc transporter ZnT1 cause aldosterone-producing adenomas and primary aldosteronism.

Primary aldosteronism (PA) is the most common form of endocrine hypertension and is characterized by inappropriately elevated aldosterone production via a renin-independent mechanism. Driver somatic mutations for aldosterone excess have been found in approximately 90% of aldosterone-producing adenomas (APAs). Other causes of lateralized adrenal PA include aldosterone-producing nodules (APNs). Using next-generation sequencing, we identified recurrent in-frame deletions in SLC30A1 in four APAs and one APN (p.L51_A57del, n = 3; p.L49_L55del, n = 2). SLC30A1 encodes the ubiquitous zinc efflux transporter ZnT1 (zinc transporter 1). The identified SLC30A1 variants are situated close to the zinc-binding site (His43 and Asp47) in transmembrane domain II and probably cause abnormal ion transport. Cases of PA with SLC30A1 mutations showed male dominance and demonstrated increased aldosterone and 18-oxocortisol concentrations. Functional studies of the SLC30A151_57del variant in a doxycycline-inducible adrenal cell system revealed pathological Na+ influx. An aberrant Na+ current led to depolarization of the resting membrane potential and, thus, to the opening of voltage-gated calcium (Ca2+) channels. This resulted in an increase in cytosolic Ca2+ activity, which stimulated CYP11B2 mRNA expression and aldosterone production. Collectively, these data implicate zinc transporter alterations as a dominant driver of aldosterone excess in PA.

Targeting Oncogenic Wnt/ß-Catenin Signaling in Adrenocortical Carcinoma Disrupts ECM Expression and Impairs Tumor Growth.

Adrenocortical carcinoma (ACC) is a rare but highly aggressive cancer with limited treatment options and poor survival for patients with advanced disease. An improved understanding of the transcriptional programs engaged in ACC will help direct rational, targeted therapies. Whereas activating mutations in Wnt/ß-catenin signaling are frequently observed, the ß-catenin-dependent transcriptional targets that promote tumor progression are poorly understood. To address this question, we analyzed ACC transcriptome data and identified a novel Wnt/ß-catenin-associated signature in ACC enriched for the extracellular matrix (ECM) and predictive of poor survival. This suggested an oncogenic role for Wnt/ß-catenin in regulating the ACC microenvironment. We further investigated the minor fibrillar collagen, collagen XI alpha 1 (COL11A1), and found that COL11A1 expression originates specifically from cancer cells and is strongly correlated with both Wnt/ß-catenin activation and poor patient survival. Inhibition of constitutively active Wnt/ß-catenin signaling in the human ACC cell line, NCI-H295R, significantly reduced the expression of COL11A1 and other ECM components and decreased cancer cell viability. To investigate the preclinical potential of Wnt/ß-catenin inhibition in the adrenal microenvironment, we developed a minimally invasive orthotopic xenograft model of ACC and demonstrated that treatment with the newly developed Wnt/ß-catenin:TBL1 inhibitor Tegavivint significantly reduced tumor growth. Together, our data support that the inhibition of aberrantly active Wnt/ß-catenin disrupts transcriptional reprogramming of the microenvironment and reduces ACC growth and survival. Furthermore, this ß-catenin-dependent oncogenic program can be therapeutically targeted with a newly developed Wnt/ß-catenin inhibitor. These results show promise for the further clinical development of Wnt/ß-catenin inhibitors in ACC and unveil a novel Wnt/ß-catenin-regulated transcriptome.

ß-Catenin-Driven Differentiation Is a Tissue-Specific Epigenetic Vulnerability in Adrenal Cancer.

Adrenocortical carcinoma (ACC) is a rare cancer in which tissue-specific differentiation is paradoxically associated with dismal outcomes. The differentiated ACC subtype CIMP-high is prevalent, incurable, and routinely fatal. CIMP-high ACC possess abnormal DNA methylation and frequent ß-catenin-activating mutations. Here, we demonstrated that ACC differentiation is maintained by a balance between nuclear, tissue-specific ß-catenin-containing complexes, and the epigenome. On chromatin, ß-catenin bound master adrenal transcription factor SF1 and hijacked the adrenocortical super-enhancer landscape to maintain differentiation in CIMP-high ACC; off chromatin, ß-catenin bound histone methyltransferase EZH2. SF1/ß-catenin and EZH2/ß-catenin complexes present in normal adrenals persisted through all phases of ACC evolution. Pharmacologic EZH2 inhibition in CIMP-high ACC expelled SF1/ß-catenin from chromatin and favored EZH2/ß-catenin assembly, erasing differentiation and restraining cancer growth in vitro and in vivo. These studies illustrate how tissue-specific programs shape oncogene selection, surreptitiously encoding targetable therapeutic vulnerabilities. SIGNIFICANCE: Oncogenic ß-catenin can use tissue-specific partners to regulate cellular differentiation programs that can be reversed by epigenetic therapies, identifying epigenetic control of differentiation as a viable target for ß-catenin-driven cancers.

Senescence-induced immune remodeling facilitates metastatic adrenal cancer in a sex-dimorphic manner.

Aging markedly increases cancer risk, yet our mechanistic understanding of how aging influences cancer initiation is limited. Here we demonstrate that the loss of ZNRF3, an inhibitor of Wnt signaling that is frequently mutated in adrenocortical carcinoma, leads to the induction of cellular senescence that remodels the tissue microenvironment and ultimately permits metastatic adrenal cancer in old animals. The effects are sexually dimorphic, with males exhibiting earlier senescence activation and a greater innate immune response, driven in part by androgens, resulting in high myeloid cell accumulation and lower incidence of malignancy. Conversely, females present a dampened immune response and increased susceptibility to metastatic cancer. Senescence-recruited myeloid cells become depleted as tumors progress, which is recapitulated in patients in whom a low myeloid signature is associated with worse outcomes. Our study uncovers a role for myeloid cells in restraining adrenal cancer with substantial prognostic value and provides a model for interrogating pleiotropic effects of cellular senescence in cancer.

Variation in the Diagnosis of Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features.

CONTEXT: Noninvasive encapsulated follicular variant of papillary thyroid cancer was reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) in January 2017. The impact of this nomenclature change at a population level remains unknown. OBJECTIVE: Examine use of NIFTP across different US regions and populations. DESIGN: Descriptive epidemiology study using SEER-22 data (2000-2019). PARTICIPANTS: Individuals diagnosed with papillary or follicular thyroid cancer (2000-2019) or NIFTP (2017-2019). MAIN OUTCOME MEASURES: Annual incidence rates of thyroid cancer by subtype and NIFTP. Using 2018-2019 data, (1) rates of NIFTP at the 17 SEER-22 sites and (2) comparison of demographics for patients diagnosed with NIFTP vs papillary and follicular thyroid cancer. RESULTS: NIFTP comprised 2.2% and 2.6% of cases in 2018 and 2019, respectively. Between 2018 and 2019, large heterogeneity was observed in the regional use of NIFTP diagnosis, with site-specific incidence rates between 0.0% and 6.2% (median 2.8%, interquartile range 1.3-3.6%). A diagnosis of NIFTP (vs papillary and follicular thyroid cancer) in 2018 and 2019 was significantly associated with older age (P = 0.012 and P = 0.009, respectively), Black race (both Ps < 0.001), and non-Hispanic ethnicity (both Ps < 0.001). CONCLUSIONS: Marked variation exists in the use of the NIFTP diagnosis. The recent 2021 coding change that resulted in NIFTP, a tumor with uncertain malignant potential and for which there is no long-term outcome data available, no longer being a reportable diagnosis to SEER will disproportionately affect vulnerable patient groups such as older patients and Black patients, in addition to patients who reside in regions with higher rates of NIFTP diagnoses.

Histopathology and Genetic Causes of Primary Aldosteronism in Young Adults.

CONTEXT: Due to its rare incidence, molecular features of primary aldosteronism (PA) in young adults are largely unknown. Recently developed targeted mutational analysis identified aldosterone-driver somatic mutations in aldosterone-producing lesions, including aldosterone-producing adenomas (APAs), aldosterone-producing nodules (APNs), and aldosterone-producing micronodules, formerly known as aldosterone-producing cell clusters. OBJECTIVE: To investigate histologic and genetic characteristics of lateralized PA in young adults. METHODS: Formalin-fixed, paraffin-embedded adrenal tissue sections from 74 young patients with lateralized PA (<35 years old) were used for this study. Immunohistochemistry (IHC) for aldosterone synthase (CYP11B2) was performed to define the histopathologic diagnosis. Somatic mutations in aldosterone-producing lesions were further determined by CYP11B2 IHC-guided DNA sequencing. RESULTS: Based on the CYP11B2 IHC results, histopathologic classification was made as follows: 48 APAs, 20 APNs, 2 multiple aldosterone-producing nodules (MAPN), 1 double APN, 1 APA with MAPN, and 2 nonfunctioning adenomas (NFAs). Of 45 APAs with successful sequencing, 43 (96%) had somatic mutations, with KCNJ5 mutations being the most common genetic cause of young-onset APA (35/45, 78%). Of 18 APNs with successful sequencing, all of them harbored somatic mutations, with CACNA1D mutations being the most frequent genetic alteration in young-onset APN (8/18, 44%). Multiple CYP11B2-expressing lesions in patients with MAPN showed several aldosterone-driver mutations. No somatic mutations were identified in NFAs. CONCLUSION: APA is the most common histologic feature of lateralized PA in young adults. Somatic KCNJ5 mutations are common in APAs, whereas CACNA1D mutations are often seen in APNs in this young PA population.

Targeted Mutational Analysis of Cortisol-Producing Adenomas.

CONTEXT: Somatic gene mutations have been identified in only about half of cortisol-producing adenomas (CPAs). Affected genes include PRKACA, GNAS, PRKAR1A, and CTNNB1. OBJECTIVE: This work aims to expand our understanding of the prevalence of somatic mutations in CPAs from patients with overt Cushing syndrome (OCS) and "subclinical" mild autonomous cortisol excess (MACE), with an immunohistochemistry (IHC)‒guided targeted amplicon sequencing approach using formalin-fixed paraffin-embedded (FFPE) tissue. METHODS: We analyzed FFPE adrenal tissue from 77 patients (n = 12 men, 65 women) with either OCS (n = 32) or MACE (n = 45). Using IHC for 17α-hydroxylase/17,20-lyase (CYP17A1) and 3ß-hydroxysteroid dehydrogenase (HSD3B2), we identified 78 CPAs (32 OCS CPAs and 46 MACE CPAs). Genomic DNA was isolated from the FFPE CPAs and subjected to targeted amplicon sequencing for identification of somatic mutations. RESULTS: Somatic mutations were identified in 71.8% (56/78) of the CPAs. While PRKACA was the most frequently mutated gene in OCS CPAs (14/32, 43.8%), somatic genetic aberrations in CTNNB1 occurred in 56.5% (26/46) of the MACE CPAs. Most GNAS mutations were observed in MACE CPAs (5/7, 71.4%). No mutations were observed in PRKAR1A. In addition to the known mutations, we identified one previously unreported mutation in PRKACA. Two patients with MACE harbored 2 adjacent tumors within the same adrenal gland - one patient had 2 CPAs, and the other patient had a CPA and an aldosterone-producing adenoma (identified by IHC for aldosterone synthase). CONCLUSION: A comprehensive FFPE IHC-guided gene-targeted sequencing approach identified somatic mutations in 71.8% of the CPAs. OCS CPAs demonstrated a distinct mutation profile compared to MACE CPAs.

Single-cell analyses of renal cell cancers reveal insights into tumor microenvironment, cell of origin, and therapy response.

Diverse subtypes of renal cell carcinomas (RCCs) display a wide spectrum of histomorphologies, proteogenomic alterations, immune cell infiltration patterns, and clinical behavior. Delineating the cells of origin for different RCC subtypes will provide mechanistic insights into their diverse pathobiology. Here, we employed single-cell RNA sequencing (scRNA-seq) to develop benign and malignant renal cell atlases. Using a random forest model trained on this cell atlas, we predicted the putative cell of origin for more than 10 RCC subtypes. scRNA-seq also revealed several attributes of the tumor microenvironment in the most common subtype of kidney cancer, clear cell RCC (ccRCC). We elucidated an active role for tumor epithelia in promoting immune cell infiltration, potentially explaining why ccRCC responds to immune checkpoint inhibitors, despite having a low neoantigen burden. In addition, we characterized an association between high endothelial cell types and lack of response to immunotherapy in ccRCC. Taken together, these single-cell analyses of benign kidney and RCC provide insight into the putative cell of origin for RCC subtypes and highlight the important role of the tumor microenvironment in influencing ccRCC biology and response to therapy.

Significance of Alpha-inhibin Expression in Pheochromocytomas and Paragangliomas.

Alpha-inhibin expression has been reported in pheochromocytomas and paragangliomas (PPGLs). We analyzed alpha-inhibin immunohistochemistry in 77 PPGLs (37 pheochromocytomas [PCCs] and 40 paragangliomas) and correlated the results with catecholamine profile, tumor size, Ki-67 labeling index, succinate dehydrogenase B subunit and carbonic anhydrase IX (CAIX) staining, and genetic pathogenesis. PPGLs were classified as pseudohypoxic cluster 1 disease with documented VHL mutation or SDHx mutation or biochemical phenotype, whereas NF1-driven and RET-driven PPGLs and those with a mature secretory (adrenergic or mixed adrenergic and noradrenergic) phenotype were classified as cluster 2 disease. The Cancer Genome Atlas data on INHA expression in PPGLs was examined. Alpha-inhibin was positive in 43 PPGLs (56%). Ki-67 labeling indices were 8.07% and 4.43% in inhibin-positive and inhibin-negative PPGLs, respectively (P<0.05). Alpha-inhibin expression did not correlate with tumor size. Alpha-inhibin was expressed in 92% of SDHx-related and 86% of VHL-related PPGLs. CAIX membranous staining was found in 8 of 51 (16%) tumors, including 1 SDHx-related PCC and all 5 VHL-related PCCs. NF1-driven and RET-driven PPGLs were negative for alpha-inhibin and CAIX. Alpha-inhibin was expressed in 77% of PPGLs with a pseudohypoxia signature, and 20% of PPGLs without a pseudohypoxia signature (P<0.05). PPGLs with a mature secretory phenotype were negative for CAIX. The Cancer Genome Atlas data confirmed higher expression of INHA in cluster 1 than in cluster 2 PPGLs. This study identifies alpha-inhibin as a highly sensitive (90.3%) marker for SDHx/VHL-driven pseudohypoxic PPGLs. Although CAIX has low sensitivity, it is the most specific biomarker of VHL-related pathogenesis. While alpha-inhibin cannot replace succinate dehydrogenase B subunit immunohistochemistry for detection of SDHx-related disease, it adds value in prediction of cluster 1 disease. Importantly, these data emphasize that alpha-inhibin is not a specific marker of adrenal cortical differentiation, as it is also expressed in PCCs.

What Did We Learn from the Molecular Biology of Adrenal Cortical Neoplasia? From Histopathology to Translational Genomics.

Approximately one-tenth of the general population exhibit adrenal cortical nodules, and the incidence has increased. Afflicted patients display a multifaceted symptomatology-sometimes with rather spectacular features. Given the general infrequency as well as the specific clinical, histological, and molecular considerations characterizing these lesions, adrenal cortical tumors should be investigated by endocrine pathologists in high-volume tertiary centers. Even so, to distinguish specific forms of benign adrenal cortical lesions as well as to pinpoint malignant cases with the highest risk of poor outcome is often challenging using conventional histology alone, and molecular genetics and translational biomarkers are therefore gaining increased attention as a possible discriminator in this context. In general, our understanding of adrenal cortical tumorigenesis has increased tremendously the last decade, not least due to the development of next-generation sequencing techniques. Comprehensive analyses have helped establish the link between benign aldosterone-producing adrenal cortical proliferations and ion channel mutations, as well as mutations in the protein kinase A (PKA) signaling pathway coupled to cortisol-producing adrenal cortical lesions. Moreover, molecular classifications of adrenal cortical tumors have facilitated the distinction of benign from malignant forms, as well as the prognostication of the individual patients with verified adrenal cortical carcinoma, enabling high-resolution diagnostics that is not entirely possible by histology alone. Therefore, combinations of histology, immunohistochemistry, and next-generation multi-omic analyses are all needed in an integrated fashion to properly distinguish malignancy in some cases. Despite significant progress made in the field, current clinical and pathological challenges include the preoperative distinction of non-metastatic low-grade adrenal cortical carcinoma confined to the adrenal gland, adoption of individualized therapeutic algorithms aligned with molecular and histopathologic risk stratification tools, and histological confirmation of functional adrenal cortical disease in the context of multifocal adrenal cortical proliferations. We herein review the histological, genetic, and epigenetic landscapes of benign and malignant adrenal cortical neoplasia from a modern surgical endocrine pathology perspective and highlight key mechanisms of value for diagnostic and prognostic purposes.

The Age-Dependent Changes of the Human Adrenal Cortical Zones Are Not Congruent.

BACKGROUND: While previous studies indicate that the zonae reticularis (ZR) and glomerulosa (ZG) diminish with aging, little is known about age-related transformations of the zona fasciculata (ZF). OBJECTIVES: To investigate the morphological and functional changes of the adrenal cortex across adulthood, with emphasis on (i) the understudied ZF and (ii) sexual dimorphisms. METHODS: We used immunohistochemistry to evaluate the expression of aldosterone synthase (CYP11B2), visinin-like protein 1 (VSNL1), 3ß-hydroxysteroid dehydrogenase type II (HSD3B2), 11ß-hydroxylase (CYP11B1), and cytochrome b5 type A (CYB5A) in adrenal glands from 60 adults (30 men), aged 18 to 86. Additionally, we employed mass spectrometry to quantify the morning serum concentrations of cortisol, 11-deoxycortisol (11dF), 17α-hydroxyprogesterone, 11-deoxycorticosterone, corticosterone, and androstenedione in 149 pairs of age- and body mass index-matched men and women, age 21 to 95 years. RESULTS: The total cortical area was positively correlated with age (r = 0.34, P = 0.008). Both the total (VSNL1-positive) and functional ZG (CYP11B2-positive) areas declined with aging in men (r = -0.57 and -0.67, P < 0.01), but not in women. The CYB5A-positive area declined with age in both sexes (r = -0.76, P < 0.0001). In contrast, the estimated ZF area correlated positively with age in men (r = 0.59, P = 0.0006) and women (r = 0.49, P = 0.007), while CYP11B1-positive area remained unchanged across ages. Serum cortisol, corticosterone, and 11-deoxycorticosterone levels were stable across ages, while 11dF levels increased slightly with age (r = 0.16, P = 0.007). CONCLUSION: Unlike the ZG and ZR, the ZF and the total adrenal cortex areas enlarge with aging. An abrupt decline of the ZG occurs with age in men only, possibly contributing to sexual dimorphism in cardiovascular risk.

The Exceptional Responders Initiative: Feasibility of a National Cancer Institute Pilot Study.

BACKGROUND: Tumor molecular profiling from patients experiencing exceptional responses to systemic therapy may provide insights into cancer biology and improve treatment tailoring. This pilot study evaluates the feasibility of identifying exceptional responders retrospectively, obtaining pre-exceptional response treatment tumor tissues, and analyzing them with state-of-the-art molecular analysis tools to identify potential molecular explanations for responses. METHODS: Exceptional response was defined as partial (PR) or complete (CR) response to a systemic treatment with population PR or CR rate less than 10% or an unusually long response (eg, duration >3 times published median). Cases proposed by patients' clinicians were reviewed by clinical and translational experts. Tumor and normal tissue (if possible) were profiled with whole exome sequencing and, if possible, targeted deep sequencing, RNA sequencing, methylation arrays, and immunohistochemistry. Potential germline mutations were tracked for relevance to disease. RESULTS: Cases reflected a variety of tumors and standard and investigational treatments. Of 520 cases, 476 (91.5%) were accepted for further review, and 222 of 476 (46.6%) proposed cases met requirements as exceptional responders. Clinical data were obtained from 168 of 222 cases (75.7%). Tumor was provided from 130 of 168 cases (77.4%). Of 117 of the 130 (90.0%) cases with sufficient nucleic acids, 109 (93.2%) were successfully analyzed; 6 patients had potentially actionable germline mutations. CONCLUSION: Exceptional responses occur with standard and investigational treatment. Retrospective identification of exceptional responders, accessioning, and sequencing of pretreatment archived tissue is feasible. Data from molecular analyses of tumors, particularly when combining results from patients who received similar treatments, may elucidate molecular bases for exceptional responses.

International Histopathology Consensus for Unilateral Primary Aldosteronism.

OBJECTIVE: Develop a consensus for the nomenclature and definition of adrenal histopathologic features in unilateral primary aldosteronism (PA). CONTEXT: Unilateral PA is the most common surgically treated form of hypertension. Morphologic examination combined with CYP11B2 (aldosterone synthase) immunostaining reveals diverse histopathologic features of lesions in the resected adrenals. PATIENTS AND METHODS: Surgically removed adrenals (n = 37) from 90 patients operated from 2015 to 2018 in Munich, Germany, were selected to represent the broad histologic spectrum of unilateral PA. Five pathologists (Group 1 from Germany, Italy, and Japan) evaluated the histopathology of hematoxylin-eosin (HE) and CYP11B2 immunostained sections, and a consensus was established to define the identifiable features. The consensus was subsequently used by 6 additional pathologists (Group 2 from Australia, Brazil, Canada, Japan, United Kingdom, United States) for the assessment of all adrenals with disagreement for histopathologic diagnoses among group 1 pathologists. RESULTS: Consensus was achieved to define histopathologic features associated with PA. Use of CYP11B2 immunostaining resulted in a change of the original HE morphology-driven diagnosis in 5 (14%) of 37 cases. Using the consensus criteria, group 2 pathologists agreed for the evaluation of 11 of the 12 cases of disagreement among group 1 pathologists. CONCLUSION: The HISTALDO (histopathology of primary aldosteronism) consensus is useful to standardize nomenclature and achieve consistency among pathologists for the histopathologic diagnosis of unilateral PA. CYP11B2 immunohistochemistry should be incorporated into the routine clinical diagnostic workup to localize the likely source of aldosterone production.

Data set for reporting of carcinoma of the adrenal cortex: explanations and recommendations of the guidelines from the International Collaboration on Cancer Reporting.

Complete resection of adrenal cortical carcinoma (ACC) with or without adjuvant therapy offers the best outcome. Recurrence is common, and in individual cases, the long-term outcome is difficult to predict, making it challenging to personalize treatment options. Current risk stratification approaches are based on clinical and conventional surgical pathology assessment. Rigorous and uniform pathological assessment may improve care for individual patients and facilitate multi-institutional collaborative studies. The International Collaboration on Cancer Reporting (ICCR) convened an expert panel to review ACC pathology reporting. Consensus recommendations were made based on the most recent literature and expert opinion. The data set comprises 23 core (required) items. The core pathological features include the following: diagnosis as per the current World Health Organization classification, specimen integrity, greatest dimension, weight, extent of invasion, architecture, percentage of lipid-rich cells, capsular invasion, lymphatic invasion, vascular invasion, atypical mitotic figures, coagulative necrosis, nuclear grade, mitotic count, Ki-67 proliferative index, margin status, lymph node status, and pathological stage. Tumors were dichotomized into low-grade (<20 mitoses per 10 mm2) and high-grade (>20 mitoses per 10 mm2) ones. Additional noncore elements that may be useful in individual cases included several multifactorial risk assessment systems (Weiss, modified Weiss, Lin-Weiss-Bisceglia, reticulin, Helsinki, and Armed Forces Institute of Pathology scores/algorithms). This data set is now available through the ICCR website with the hope of better standardizing pathological assessment of these relatively rare but important malignancies.

Identification of Somatic Mutations in CLCN2 in Aldosterone-Producing Adenomas.

Somatic mutations driving aldosterone production have been identified in approximately 90% of aldosterone-producing adenomas (APAs) using an aldosterone synthase (CYP11B2) immunohistochemistry (IHC)-guided DNA sequencing approach. In the present study, using CYP11B2-guided whole-exome sequencing (WES) and targeted amplicon sequencing, we detected 2 somatic variants in CLCN2 in 2 APAs that were negative for currently known aldosterone-driver mutations. The CLCN2 gene encodes the voltage-gated chloride channel ClC-2. CLCN2 germline variants have previously been shown to cause familial hyperaldosteronism type II. Somatic mutations in CLCN2 were identified in 2 of 115 APAs, resulting in a prevalence of 1.74%. One of the CLCN2 somatic mutations (c.G71A,p.G24D) was identical to a previously described germline variant causing early-onset PA, but was present only as a somatic mutation. The second CLCN2 mutation, which affects the same region of the gene, has not been reported previously (c.64-2_74del). These findings prove that WES of CYP11B2-guided mutation-negative APAs can help determine rarer genetic causes of sporadic PA.

Targeted RNAseq of Formalin-Fixed Paraffin-Embedded Tissue to Differentiate Among Benign and Malignant Adrenal Cortical Tumors.

Lack of routine fresh or frozen tissue is a barrier to widespread transcriptomic analysis of adrenal cortical tumors and an impediment to translational research in endocrinology and endocrine oncology. Our group has previously pioneered the use of targeted amplicon-based next-generation sequencing for archival formalin-fixed paraffin-embedded (FFPE) adrenal tissue specimens to characterize the spectrum of somatic mutations in various forms of primary aldosteronism. Herein, we developed and validated a novel 194-amplicon targeted next-generation RNA sequencing (RNAseq) assay for transcriptomic analysis of adrenal tumors using clinical-grade FFPE specimens. Targeted RNAseq-derived expression values for 27 adrenal cortical tumors, including aldosterone-producing adenomas (APA; n=8), cortisol-producing adenomas (CPA; n=11), and adrenal cortical carcinomas (ACC; n=8), highlighted known differentially-expressed genes (DEGs; i. e., CYP11B2, IGF2, etc.) and tumor type-specific transcriptional modules (i. e., high cell cycle/proliferation transcript expression in ACC, etc.), and a subset of DEGs was validated orthogonally using quantitative reverse transcription PCR (qRT-PCR). Finally, unsupervised hierarchical clustering using a subset of high-confidence DEGs revealed three discrete clusters representing APA, CPA, and ACC tumors with corresponding unique gene expression signatures, suggesting potential clinical utility for a transcriptomic-based approach to tumor classification. Overall, these data support the use of targeted amplicon-based RNAseq for comprehensive transcriptomic profiling of archival FFPE adrenal tumor material and indicate that this approach may facilitate important translational research opportunities for the study of these tumors.

Multiplatform molecular test performance in indeterminate thyroid nodules.

BACKGROUND: Approximately 25% of thyroid nodule fine-needle aspirates (FNAs) have cytology that is indeterminate for malignant disease. Accurate risk stratification of these FNAs with ancillary testing would reduce unnecessary thyroid surgery. METHODS: We evaluated the performance of an ancillary multiplatform test (MPTX) that has three diagnostic categories (negative, moderate, and positive). MPTX includes the combination of a mutation panel (ThyGeNEXT®) and a microRNA risk classifier (ThyraMIR®). A blinded, multicenter study was performed using consensus histopathology diagnosis among three pathologists to validate test performance. RESULTS: Unanimous consensus diagnosis was reached in 197 subjects with indeterminate thyroid nodules; 36% had disease. MPTX had 95% sensitivity (95% CI,86%-99%) and 90% specificity (95% CI,84%-95%) for disease in prevalence adjusted nodules with Bethesda III and IV cytology. Negative MPTX results ruledout disease with 97% negative predictive value (NPV; 95% CI,91%-99%) at a 30% disease prevalence, while positive MPTX results ruledin high risk disease with 75% positive predictive value (PPV; 95% CI,60%-86%). Such results are expected in four out of five Bethesda III and IV nodules tested, including RAS positive nodules in which the microRNA classifier was useful in rulingin disease. 90% of mutation panel false positives were due to analytically verified RAS mutations detected in benign adenomas. Moderate MPTX results had a moderate rate of disease (39%, 95% CI,23%-54%), primarily due to RAS mutations, wherein the possibility of disease could not be excluded. CONCLUSIONS: Our results emphasize that decisions for surgery should not solely be based on RAS or RAS-like mutations. MPTX informs management decisions while accounting for these challenges.

Multi-Institutional Prospective Validation of Prognostic mRNA Signatures in Early Stage Squamous Lung Cancer (Alliance).

INTRODUCTION: Surgical resection is curative for some patients with early lung squamous cell carcinoma. Staging and clinical factors do not adequately predict recurrence risk. We sought to validate the discriminative performance of proposed prognostic gene expression signatures at a level of rigor sufficient to support clinical use. METHODS: The two-stage validation used independent core laboratories, objective quality control standards, locked test parameters, and large multi-institutional specimen and data sets. The first stage validation confirmed a signature's ability to stratify patient survival. The second-stage validation determined which signature(s) optimally improved risk discrimination when added to baseline clinical predictors. Participants were prospectively enrolled in institutional (cohort I) or cooperative group (cohort II) biospecimen and data collection protocols. All cases underwent a central review of clinical, pathologic, and biospecimen parameters using objective criteria to determine final inclusion (cohort I: n = 249; cohort II: n = 234). Primary selection required that a signature significantly predict a 3-year survival after surgical resection in cohort I. Signatures meeting this criterion were further tested in cohort II, comparing risk prediction using baseline risk factors alone versus in combination with the signature. RESULTS: Male sex, advanced age, and higher stage were associated with shorter survival in cohort I and established a baseline clinical model. Of the three signatures validated in cohort I, one signature was validated in cohort II and statistically significantly enhanced the prognosis relative to the baseline model (C-index difference 0.122; p < 0.05). CONCLUSIONS: These results represent the first rigorous validation of a test appropriate to direct adjuvant treatment or clinical trials for patients with lung squamous cell carcinoma.

Novel role of ASH1L histone methyltransferase in anaplastic thyroid carcinoma.

Anaplastic thyroid cancer (ATC) is one of the most aggressive human malignancies, with an average life expectancy of ∼6 months from the time of diagnosis. The genetic and epigenetic changes that underlie this malignancy are incompletely understood. We found that ASH1-like histone lysine methyltransferase (ASH1L) is overexpressed in ATC relative to the much less aggressive and more common differentiated thyroid cancer. This increased expression was due at least in part to reduced levels of microRNA-200b-3p (miR-200b-3p), which represses ASH1L expression, in ATC. Genetic knockout of ASH1L protein expression in ATC cell lines decreased cell growth both in culture and in mouse xenografts. RNA-Seq analysis of ASH1L knockout versus WT ATC cell lines revealed that ASH1L is involved in the regulation of numerous cancer-related genes and gene sets. The pro-oncogenic long noncoding RNA colon cancer-associated transcript 1 (CCAT1) was one of the most highly (approximately 68-fold) down-regulated transcripts in ASH1L knockout cells. Therefore, we investigated CCAT1 as a potential mediator of the growth-inducing activity of ASH1L. Supporting this hypothesis, CCAT1 knockdown in ATC cells decreased their growth rate, and ChIP-Seq data indicated that CCAT1 is likely a direct target of ASH1L's histone methyltransferase activity. These results indicate that ASH1L contributes to the aggressiveness of ATC and suggest that ASH1L, along with its upstream regulator miR-200b-3p and its downstream mediator CCAT1, represents a potential therapeutic target in ATC.

Next-generation RNA Sequencing-based Biomarker Characterization of Chromophobe Renal Cell Carcinoma and Related Oncocytic Neoplasms.

BACKGROUND: Renal cell carcinomas (RCCs) are a heterogeneous group of neoplasms. Recent sequencing studies revealed various molecular features associated with histologic RCC subtypes, including chromophobe renal cell carcinoma (ChRCC). OBJECTIVE: To characterize the gene expression and biomarker signatures associated with ChRCC. DESIGN, SETTING, AND PARTICIPANTS: We performed integrative analysis on RNA sequencing data available from 1049 RCC specimens from The Cancer Genome Atlas and in-house studies. Our workflow identified genes relatively enriched in ChRCC, including Forkhead box I1 (FOXI1), Rh family C glycoprotein (RHCG), and LINC01187. We assessed the expression pattern of FOXI1 and RHCG protein by immunohistochemistry (IHC) and LINC01187 mRNA by RNA in situ hybridization (RNA-ISH) in whole tissue sections representing a cohort of 197 RCC cases, including both primary and metastatic tumors. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The FOXI1 and RHCG IHC staining, as well as the LINC01187 RNA-ISH staining, was evaluated in each case for intensity, pattern, and localization of expression. RESULTS AND LIMITATIONS: All primary and metastatic classic ChRCCs demonstrated homogeneous positive labeling for FOXI1, RHCG proteins, and LINC01187 transcript. Unclassified RCC with oncocytic features, oncocytoma, and hybrid oncocytic tumor, as well as all but two cases of eosinophilic ChRCC also stained positive. Importantly, metastatic and primary RCC of all other subtypes did not demonstrate any unequivocal staining for FOXI1, RHCG, or LINC01187. In normal kidney, FOXI1, RHCG, and LINC01187 were detected in the distal nephron segment, specifically in intercalated cells. Two cases of eosinophilic ChRCC with focal expression of FOXI1 and LINC01187, and Golgi-like RHCG staining were found to contain MTOR gene mutations upon DNA sequencing. CONCLUSIONS: We demonstrate a pipeline for the identification and validation of RCC subtype-specific biomarkers that can aid in the confirmation of cell of origin and may facilitate accurate classification and diagnosis of renal tumors. PATIENT SUMMARY: FOXI1, RHCG, and LINC01187 are lineage-specific signature genes for chromophobe renal cell carcinoma.