Salivary Adenoid Cystic Carcinoma Research Articles

Salivary gland adenoid cystic carcinoma in the U.S population: Importance of grade, site of metastases, and adjuvant radiation for survival

BackgroundAdenoid cystic carcinoma (AdCC) is a rare and relatively heterogenous salivary gland malignancy, for which there is debate regarding grading, and clinical prognostic factors, including the role of adjuvant radiotherapy. MethodsSurveillance, Epidemiology, and End Results (SEER) data were reviewed for AdCC cases from 2000 to 2018. ResultsA total of 1978 patients with AdCC were identified. Most patients were between 50 and 59 years of age (21.4 %), female (59.9 %), and Caucasian (76.8 %). Most tumors were localized at presentation (44.3 %), and moderately differentiated (or grade II) (43.7 %). Overall and DSS 5-year survival rates were 70.7 % (95 % CI, 69.9–78.8), and 78.6 % (95 % CI, 77.6–79.6). The best overall 5-year survival rate was observed for those treated with surgery plus radiation, 76.8 % (95 % CI, 75.5–78.1). Multivariate analysis revealed male sex, age > 65 (H.R. 2.659 (95 % CI,2.291–3.098), p < .001), grade III/IV (H.R.5.172 (95 % CI, 3.418–7.824), p < .001), nodal metastasis, distant metastasis (H.R. 2.400 (95 % CI, 2.178–2.645), p < .001), chemotherapy only, and combination therapy as negative prognostic factors, and receiving surgery plus radiation therapy (H.R.0.586 (95 % CI, 0.505–0.679), p < .001) as a positive prognostic factor. When limited just to the lungs, had much better survival than those patients with distant metastases to other sites such as the bones and liver (p < .001). ConclusionThis SEER study identifies grade, particularly III and IV, to be the strongest single predictor of worse survival. Patients did best when treated with surgery and postoperative radiotherapy. These results can inform future management of patients with this challenging cancer type.

HSP27 promotes vasculogenic mimicry formation in human salivary adenoid cystic carcinoma via the AKT-MMP-2/9 pathway

PurposeTo explore the role and mechanism of heat shock protein 27 (HSP27) in SACC VM formation. Study DesignImmunohistochemistry and double staining with cluster of differentiation 31 (CD31) and periodic acid-Schiff (PAS) were used to detect HSP27 expression and VM in 70 SACC tissue samples separately. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis, and immunofluorescence were used to detect gene and protein expression. HSP27 in SACC cells were overexpression or downregulated by transfecting HSP27 or short hairpin RNA target HSP27 (sh-HSP27). The migration and invasion abilities of SACC cells were detected using wound healing and Transwell invasion assays. The VM formation ability of the cells in vitro was detected using a Matrigel three-dimensional culture. ResultsHSP27 expression was positively correlated with VM formation and affected the prognosis of patients. In vitro, HSP27 upregulation engendered VM formation and the invasion and migration of SACC cells. Mechanistically, HSP27 upregulation increased Akt phosphorylation and subsequently increased downstream matrix metalloproteinase 2 and 9 expressions. ConclusionHSP27 may plays an important role in VM formation in SACC via the AKT-MMP-2/9 signalling pathway.

EN1 promotes lung metastasis of salivary adenoid cystic carcinoma by regulating the PI3K-AKT pathway and epithelial-mesenchymal transition

BackgroundEngrailed homeobox 1 (EN1) is a candidate oncogene that is epigenetically modified in salivary adenoid cystic carcinoma (SACC). We investigated the expression of EN1 in SACC tissues and cells, EN1 promoter methylation, and the role of EN1 in tumour progression in SACC.MethodsThirty-five SACC samples were screened for key transcription factors that affect tumour progression. In vitro and in vivo assays were performed to determine the viability, tumorigenicity, and metastatic ability of SACC cells with modulated EN1 expression. Quantitative methylation-specific polymerase chain reaction analysis was performed on SACC samples.ResultsEN1 was identified as a transcription factor that was highly overexpressed in SACC tissues, regardless of clinical stage and histology subtype, and its level of expression correlated with distant metastasis. EN1 promoted cell invasion and migration through epithelial-mesenchymal transition in vitro and enhanced SACC metastasis to the lung in vivo. RNA-seq combined with in vitro assays indicated that EN1 might play an oncogenic role in SACC through the PI3K-AKT pathway. EN1 mRNA levels were negatively correlated with promoter hypermethylation, and inhibition of DNA methylation by 5-aza-dC increased EN1 expression.ConclusionsThe transcription factor EN1 is overexpressed in SACC under methylation regulation and plays a pivotal role in SACC progression through the PI3K-AKT pathway. These results suggest that EN1 may be a diagnostic biomarker and a potential therapeutic target for SACC.

NAT10/CEBPB/vimentin signalling axis promotes adenoid cystic carcinoma malignant phenotypes invitro.

To explore the biological function and mechanisms of CEBPB and NAT10-mediated N4-acetylcytidine (ac4c) modification in salivary adenoid cystic carcinoma (SACC). CEBPB and NAT10 were knocked down in SACC-LM cells by siRNA transfection and overexpressed in SACC-83 cells by plasmid transfection. Malignant phenotypes were evaluated using CCK-8, Transwell migration and colony formation assays. Real-time PCR, western blotting, ChIP and acRIP were used to investigate the molecular mechanisms involved. We found that CEBPB was highly expressed in SACC tissues and correlated with lung metastasis and unfavourable prognosis. Gain- and loss-of-function experiments revealed that CEBPB promoted SACC malignant phenotypes. Mechanistically, CEBPB exerted its oncogenic effect by binding to the vimentin gene promoter region to enhance its expression. Moreover, NAT10-mediated ac4c modification led to stabilization and overexpression of CEBPB in SACC cells. We also found that NAT10, the only known human enzyme responsible for ac4C modification, promoted SACC cell migration, proliferation and colony formation. Moreover, CEBPB overexpression restored the inhibitory effect of NAT10 knockdown on malignant phenotypes. Our study reveals the critical role of the newly identified NAT10/CEBPB/vimentin axis in SACC malignant progression, and the findings may be applied to improve treatment for SACC.

Anti-NOTCH1 therapy with OMP-52 M51 inhibits salivary adenoid cystic carcinoma by depressing epithelial-mesenchymal transition (EMT) process and inducing ferroptosis

Salivary adenoid cystic carcinoma (ACC) is a common type of salivary gland cancer, and the mechanisms underlying its progression still remain poorly understood without efficient therapies. NOTCH1, an evolutionally conserved cell-cell signaling pathway, is involved in the progression of ACC. In our study, we attempted to explore whether NOTCH1 suppression using the monoclonal anti-NOTCH1 antibody OMP-52 M51 could be of potential for ACC treatment. Here, we identified NOTCH1 elevation in human ACC tissues compared with the matched normal samples. Patients with metastasis expressed much higher NOTCH1. We then found that OMP-52 M51 markedly reduced the expression of NOTCH1 and its intracellular active form NICD1 (NOTCH1 intracellular domain). Importantly, OMP-52 M51 markedly reduced the proliferation, migration and invasion of ACC cells. RNA-Seq and in vitro studies further showed that OMP-52 M51 significantly induced ferroptosis in ACC cells, indicated by the increased cellular malondialdehyde (MDA), iron contents and lipid ROS production, and decreased glutathione (GSH) levels. Further, remarkable glutathione peroxidase 4 (GPX4) reduction was detected in ACC cells with OMP-52 M51 treatment. However, promoting NOTCH1 expression markedly abolished the function of OMP-52 M51 to induce ferroptosis. Intriguingly, low-dose OMP-52 M51 strongly facilitated the capacity of ferroptosis inducer erastin to trigger ferroptotic cell death, revealing that OMP-52 M51 could improve the sensitivity of ACC cells to ferroptosis. In vivo, OMP-52 M51 administration suppressed tumor growth and induced ferroptosis in the constructed ACC xenograft mouse model. Collectively, our findings demonstrated that NOTCH1 inhibition by OMP-52 M51 represses the proliferation and epithelial-mesenchymal transition (EMT) in ACCs, and promotes ferroptosis, revealing the potential therapeutical application of OMP-52 M51 in ACC.

Evaluation of cell proliferation marker CDC-7 in salivary adenoid cystic carcinoma

BackgroundAdenoid cystic carcinoma (AdCC) is considered one of the most common destructive types of malignant salivary gland tumor that have high affinity to perineural invasion (PNI). This study was conducted to access different histological features of AdCC, and assessment of the immunohistochemical expression of CDC-7. MethodsThirty formalin-fixed paraffin incorporated tissue blocks of AdCC were classified according to the WHO histopathological types. The immune-expression of CDC-7 positive area was evaluated according to percentage area as following: Negative = 0 %, Weak = 1–10 %, Moderate = 11–49 %, and Strong = 50–100. The correlations between expression of the marker and different clinico-pathological variables were investigated using Chi-square (χ2) test. The P‐value ≤ 0.05 was considered statistically significant. ResultsThe expression of CDC-7 revealed statistical significant difference between the different tumor types (p ≤ 0.05). ConclusionThe biological behavior of AdCC can be predicated from the expression of CDC-7.

Hypoxia induced cell dormancy of salivary adenoid cystic carcinoma through miR-922/DEC2 axis

BackgroundHypoxia has been shown to induce cancer cells to become dormant meanwhile these cells inclined to disseminate and eventually cause metastasis. However, the molecular mechanism is still elusive. The purpose is to explore whether dormancy-associated microRNAs (DmiRs) get involved in hypoxia-induced cell dormancy of salivary adenoid cystic carcinoma (SACC). Material and MethodsThis study performed multi-perspective investigation of the biological effects of miR-922/DEC2 on SACC based on clinical samples, 2D and 3D in vitro model and nude mice in vivo model, based on our previous study of overexpression of DEC2 inducing SACC cellular dormancy. ResultsAccording to the existing microRNA array of SACC tissue, we found that miR-922 was upregulated in SACC tissue and was inversely correlated with DEC2, suggesting that miR-922 might participate in the activation of SACC cell dormancy as a DmiR. Then, we found miR-922 low SACC cells exhibited cell dormancy and a low level of fatty acid oxidation with propensity for lipid droplets accumulation through DEC2. Moreover, HIF1a downregulated the level of miR-922 to induce SACC cell dormancy. In addition, in xenografts of nude mice the inhibition of miR-922 attenuated the growth of primary tumor and the lung metastasis of SACC. ConclusionsmiR-922/DEC2 axis was necessary to hypoxia-induced cell dormancy and played an important role in the lipid metabolism reprogramming of SACC.

A Precise and Intelligent Nanomedicine for Salivary Adenoid Cystic Carcinoma Treatment by Combining Antivascular Photodynamic Therapy and Neuroinhibitory Chemotherapy

AbstractSalivary adenoid cystic carcinoma (SACC) is one of the most common salivary gland malignancies. Current clinical therapies have limitations and cannot efficiently prevent the SACC development and metastasis. Hematogenous and neural spread are the two major routes of SACC metastasis. In this study, a precise and intelligent nanomedicine, RCDT, is designed to combine antivascular photodynamic therapy and neuroinhibitory chemotherapy against SACC. A tumor vessel‐targeted and reactive oxygen species (ROS)‐responsive photosensitizer (RC) is synthesized by linking cRGD to chlorin e6 (Ce6) via a bridge between the poly(ethylene glycol) and diselenide bonds. A neural‐targeted and pH‐responsive cytotoxic prodrug (DT) is synthesized by conjugating doxorubicin (DOX) with Tet1, a neural‐targeting peptide, via an acidic‐cleavable hydrazone bond. RC and DT are assembled to form RCDT via hydrophobic interactions, thereby shielding Tet1. Under the guidance of cRGD and the photodynamic action of Ce6, RCDT can precisely disrupt the tumor vasculature and simultaneously disintegrate to expose Tet1 by rupturing the diselenide bond. Guided by Tet1, disintegrated RCDT can be specifically internalized into neurons and release DOX to exert neuroinhibitory effects by cleaving the hydrazone bond. Using these stepwise dual‐targeting and dual‐responsive strategies, RCDT can efficiently suppress the growth and metastasis of SACC.

Silencing geranylgeranyltransferase I inhibits the migration and invasion of salivary adenoid cystic carcinoma through RhoA/ROCK1/MLC signaling and suppresses proliferation through cell cycle regulation.

Geranylgeranyltransferase type I (GGTase-I) significantly affects Rho proteins, such that the malignant progression of several cancers may be induced. Nevertheless, the effect and underlying mechanism of GGTase-I in the malignant progression of salivary adenoid cystic carcinoma (SACC) remain unclear. This study primarily aimed to investigate the role and mechanism of GGTase-I in mediating the malignant progression of SACC. The level of GGTase-I gene in cells was stably knocked down by short hairpin RNA-EGFP-lentivirus. The effects of GGTase-I silencing on the migration, invasion, and spread of cells were examined, the messenger RNA levels of GGTase-I and RhoA genes of SACC cells after GGTase-I knockdown were determined, and the protein levels of RhoA and RhoA membrane of SACC cells were analyzed. Moreover, the potential underlying mechanism of silencing GGTase-I on the above-mentioned aspects in SACC cells was assessed by examining the protein expression of ROCK1, MLC, p-MLC, E-cadherin, Vimentin, MMP2, and MMP9. Furthermore, the underlying mechanism of SACC cells proliferation was investigated through the analysis of the expression of cyclinD1, MYC, E2F1, and p21CIP1/WAF1 . Besides, the change of RhoA level in SACC tissues compared with normal paracancer tissues was demonstrated through quantitative reverse-transcription polymerase chain reaction and western blot experiments. Next, the effect after GGTase-I silencing was assessed through the subcutaneous tumorigenicity assay. As indicated by the result of this study, the silencing of GGTase-I significantly reduced the malignant progression of tumors in vivo while decreasing the migration, invasion, and proliferation of SACC cells and RhoA membrane, Vimentin, ROCK1, p-MLC, MMP2, MMP9, MYC, E2F1, and CyclinD1 expression. However, the protein expression of E-cadherin and p21CIP1/WAF1 was notably upregulated. Subsequently, no significant transform of RhoA and MLC proteins was identified. Furthermore, RhoA expression in SACC tissues was significantly higher than that in paracancerous tissues. As revealed by the results of this study, GGTase-I shows a correlation with the proliferation of SACC through the regulation of cell cycle and may take on vital significance in the migration and invasion of SACC by regulating RhoA/ROCK1/MLC signaling pathway. GGTase-I is expected to serve as a novel exploration site of SACC.

SAT550 Warthin-like Variant of Papillary Thyroid Carcinoma: An Even Rarer Presentation

Abstract Disclosure: J. Kunadia: None. S. Chablani: None. Introduction: We present a rare case of Warthin-like variant of papillary thyroid carcinoma (WLPTC) with later development of a second primary malignancy. Clinical Case: A 56 year old female with hypertension, hyperlipidemia, ulcerative colitis, asthma, and a strong family history of cancer presented in 2017 for evaluation of an enlarged thyroid gland noted by her primary care provider. Patient was asymptomatic and denied prior thyroid disease and head or neck radiation. Labs demonstrated normal TSH and free T4 levels. TPO antibodies were elevated to 1,155 IU/mL (reference range 0.0 – 5.5 IU/mL). Thyroid US was notable for a diffusely enlarged thyroid gland containing a 1.4 x 0.6 x 1.0 cm solid, hypoechoic nodule without calcifications in the upper pole of the right lobe. Shared decision-making resulted in a plan for continued surveillance. Repeat thyroid US in 2018 demonstrated that this nodule had increased in volume by 56.25%, now measuring 1.4 x 0.75 x 1.25 cm. Fine needle aspiration (FNA) biopsy was performed and positive for papillary thyroid carcinoma (PTC). Patient underwent total thyroidectomy; pathology revealed a 1.2 x 1 x 0.9 cm WLPTC and 0.2 cm papillary thyroid microcarcinoma. There was no evidence of extrathyroidal extension, angioinvasion, or lymph node involvement. Follow-up neck US in 2020 demonstrated a 0.4 cm hypoechoic ovoid structure in the left thyroid bed and an enlarged but morphologically normal-appearing right level II lymph node. Repeat neck US in 2021 showed the appearance of a new 2.8 cm right level II lymph node; FNA was positive for malignancy with negative thyroid transcription factor-1 staining and undetectable thyroglobulin. Patient underwent an excision biopsy of the lymph node, and pathology was consistent with metastatic adenoid cystic carcinoma (ACC). A right submandibular gland lesion detected on subsequent MRI head and neck was resected and confirmed to be the primary source of ACC. Patient was treated with adjuvant radiation therapy with adequate response to therapy. Conclusion: WLPTC is a rare subtype of PTC that accounts for 0.2-1.9% of cases and carries a strong association with Hashimoto’s thyroiditis. It is histologically characterized by papillary architecture, oncocytic changes, nuclear features of PTC, and dense lymphoplasmacytic infiltration of the papillary cores. WLPTC is considered to have a favorable prognosis given its low frequency of lymphovascular invasion and low recurrence risk. This case also highlights the importance of keeping a broad differential when evaluating new findings on neck US in patients with a history of thyroid cancer. Metastases to cervical lymph nodes most commonly occur from head and neck tumors. However, to date, only one other case of PTC with second primary malignancy of salivary ACC has been reported. Presentation Date: Saturday, June 17, 2023

Cell-type-specific tumour sensitivity identified with a bromodomain targeting PROTAC in adenoid cystic carcinoma.

Salivary gland adenoid cystic carcinoma (ACC) is a rare malignancy with limited treatment options. The development of novel therapies is hindered by a lack of preclinical models. We have generated ACC patient-derived xenograft (PDX) lines that retain the physical and genetic properties of the original tumours, including the presence of the common MYB::NFIB or MYBL1::NFIB translocations. We have developed the conditions for the generation of both 2D and 3D tumour organoid patient-derived ACC models that retain MYB expression and can be used for drug studies. Using these models, we show in vitro and in vivo sensitivity of ACC cells to the bromodomain degrader, dBET6. Molecular studies show a decrease in BRD4 and MYB protein levels and target gene expression with treatment. The most prominent effect of dBET6 on tumours in vivo was a change in the relative composition of ACC cell types expressing either myoepithelial or ductal markers. We show that dBET6 inhibits the progenitor function of ACC cells, particularly in the myoepithelial marker-expressing population, revealing a cell-type-specific sensitivity. These studies uncover a novel mechanistic effect of bromodomain inhibitors on tumours and highlight the need to impact both cell-type populations for more effective treatments in ACC patients. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

909P TROP2 expression in salivary gland adenoid cystic carcinoma (ACC): A new potential therapeutic target for the non-solid subtype

909P TROP2 expression in salivary gland adenoid cystic carcinoma (ACC): A new potential therapeutic target for the non-solid subtype

Abstract PO-092: Molecular characterization of the salivary adenoid cystic carcinoma tumor immune landscape by anatomic subsite

Abstract Introduction: Adenoid cystic carcinoma (AdCC) is typically indolent, however tends to behave more aggressively and present with perineural invasion and distant metastasis. Despite an improved understanding of AdCC pathobiology, the impact of anatomic tumor subsite (e.g., major versus minor salivary glands) on survival and response to treatment is relatively understudied. We recently discovered that submandibular AdCC’s exhibit unique differences in prognosis and treatment response to adjuvant radiotherapy. However, the impact of anatomic subsites on gene expression and immune cell composition, has not been investigated. Materials and methods: We used 4 publicly available AdCC molecular datasets (n = 37 AdCCs of different origin: 27 primary and 10 metastatic; 7 parotid (PG), 5 submandibular (SMG), 4 sublingual (SLG), 21 minor salivary gland (mG) and 21 normal salivary gland tissue samples). Data were harmonized between datasets using identical quantification procedures, followed by filtering and normalization performed simultaneously on the pooled data from all cohorts. Gene set enrichment analysis (GSEA) was performed Human Molecular Signatures Database (MSigDB) Hallmark and Oncologic signatures. Tumor immune microenvironment (TIME) decomposition was performed using a non-negative matrix factorization-based approach. GSEA and TIME differences between AdCC subsites were evaluated using Wilcoxon rank-sum and nonparametric equality-of-medians tests. Results: We identified different levels of enrichment for several key tumorigenic pathways between AdCCs arising within different anatomic subsites. Among AdCCs, major glands overexpressed the HALLMARK_SPERMATOGENESIS signature (parotid and sublingual glands), while the HALLMARK_REACTIVE_OXYGEN_SPECIES_PATHWAY (ROS) signature was significantly underexpressed in SMG AdCCs. In addition, the HALLMARK_EPITHELIAL_MESENCHYMAL_TRANSITION (EMT) signature was significantly underexpressed in both SMG and PG AdCCs. These pathway signatures were not seen in control tissue comparison samples, indicating that these features are AdCC-specific. Additionally, TIME decomposition identified differences in CD4-T cell populations (minor &amp;gt; major gland AdCC) and natural killer (NK) cells (increased in PG and SLG). Meanwhile, normal control comparisons revealed a significant increase in plasma cells only within SM glands. Conclusions: AdCC subsites exhibit survival and treatment-response differences, and in this study demonstrate that these anatomical sites are associated with distinct molecular features. Specifically, these different anatomical sites vary in the expression of spermatogenesis, ROS, and EMT signature-related genes. Also, CD4-T and NK cell populations vary by anatomical site, suggesting that the SMG AdCC tumor-intrinsic pathway differences observed may be responsible for influencing the TIME composition and increased prognosis associated with these tumors following adjuvant radiotherapy. Validation with additional cohorts of primary AdCCs with accurate clinical annotation are required. Citation Format: Jason Tasoulas, Travis Schrank, Steven Johnson, Kimon Divaris, Stamatios Theocharis, Trevor Hackman, Siddharth Sheth, Kedar Kirtane, Juan Hernandez-Prera, Christine Chung, Wendell Gray Yarbrough, Natalia Issaeva, Antonio Amelio. Molecular characterization of the salivary adenoid cystic carcinoma tumor immune landscape by anatomic subsite [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-092.

TIM-3/Galectin-9 and CD160 expression in salivary adenoid cystic carcinoma.

Investigating T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), Galectin 9 (Gal-9), CD160 expression and tumor-infiltrating lymphocytes (TILs) and correlation with clinicopathological characteristics of salivary adenoid cystic carcinoma (SACC). Sixty cases of SACC were detected by immunohistochemical staining to evaluate TIM-3, Gal-9, and CD160 expression and analyze the correlation between TIM-3, Gal-9, CD160 expression and clinicopathologic features by rank-sum test. The association of TILs with TIM-3, Gal-9, and CD160 expression in SACC stromal was done by Chi-square test. TIM-3 and CD160 overexpression were correlated with recurrence of SACC (p = 0.029, p = 0.007, respectively). High Gal-9 expression was correlated with pathological classification (p = 0.018). The average percentage of TILs was 18.2% in SACC and most of TILs were more likely to occur in minor salivary glands (p = 0.038). Pairwise positive correlations were observed between the expression of TIM-3, Gal-9, and CD160 in tumor cells as well as in TILs, respectively. Low density of TILs was characteristic of the SACC microenvironment, with upregulation of TIM-3, Gal-9, and CD160 all occurring. However, TIM-3, Gal-9, and CD160 expression in the stromal dependent on the number of TILs represent potential therapeutic targets in SACC.

The Landscape of MYB/MYBL1- and Peri-MYB/MYBL1-Associated Rearrangements in Adenoid Cystic Carcinoma

Approximately 60% of adenoid cystic carcinoma (AdCC) cases are positive for MYB::NFIB or MYBL1::NFIB, whereas MYB/MYBL1 oncoprotein, a key driver of AdCC, is overexpressed in most cases. Juxtaposition of superenhancer regions in NFIB and other genes into the MYB/MYBL1 locus is an attractive oncogenic hypothesis for AdCC cases, either negative or positive for MYB/MYBL1::NFIB. However, evidence supporting this hypothesis is insufficient. We examined 160 salivary AdCC cases for rearrangements in MYB/MYBL1 loci and peri-MYB/MYBL1 areas (centromeric and telomeric areas of 10 Mb each) using formalin-fixed, paraffin-embedded tumor sections. For the detection of the rearrangements, we employed conventional fluorescence in situ hybridization split and fusion assays and a 5 Mb fluorescence in situ hybridization split assay. The latter is a novel assay that enabled us to detect any possible splits within a 5 Mb distance of a chromosome. We found MYB/MYBL1- and peri-MYB/MYBL1-associated rearrangements in 149/160 patients (93%). AdCC cases positive for rearrangements in MYB, MYBL1, the peri-MYB area, and the peri-MYBL1 area numbered 105 (66%), 20 (13%), 19 (12%), and 5 (3%), respectively. In 24 peri-MYB/MYBL1 rearrangement-positive cases, 14 (58%) were found to have a juxtaposition of the NFIB or RAD51B locus into the MYB/MYBL1 loci. On comparing with a tumor group positive for MYB::NFIB, a hallmark of AdCC, other genetically classified tumor groups had similar features of overexpression of the MYB transcript and MYB oncoprotein as detected by semiquantitative RT-qPCR and immunohistochemistry, respectively. In addition, clinicopathological and prognostic features were similar among these groups. Our study suggests that peri-MYB/MYBL1 rearrangements may be a frequent event in AdCC and may result in biological and clinicopathological consequences comparable to MYB/MYBL1 rearrangements. The landscape of MYB/MYBL1 and peri-MYB/MYBL1 rearrangements shown here strongly suggests that juxtaposition of superenhancers into MYB/MYBL1 or peri-MYB/MYBL1 loci is an alteration that acts as a key driver for AdCC oncogenesis and may unify MYB/MYBL1 rearrangement-positive and negative cases.

Salivary glands adenoid cystic carcinoma: a molecular profile update and potential implications.

Adenoid cystic carcinoma (ACC) is an aggressive tumor with a high propensity for distant metastasis and perineural invasion. This tumor is more commonly found in regions of the head and neck, mainly the salivary glands. In general, the primary treatment modality for ACC is surgical resection and, in some cases, postoperative radiotherapy. However, no effective systemic treatment is available for patients with advanced disease. Furthermore, this tumor type is characterized by recurrent molecular alterations, especially rearrangements involving the MYB, MYBL1, and NFIB genes. In addition, they also reported copy number alterations (CNAs) that impact genes. One of them is C-KIT, mutations that affect signaling pathways such as NOTCH, PI3KCA, and PTEN, as well as alterations in chromatin remodeling genes. The identification of new molecular targets enables the development of specific therapies. Despite ongoing investigations into immunotherapy, tyrosine kinase inhibitors, and anti-angiogenics, no systemic therapy is approved by the FDA for ACC. In this review, we report the genetic and cytogenetic findings on head and neck ACC, highlighting possible targets for therapeutic interventions.

B-cell specific Moloney murine leukemia virus insertion site 1 contributes to invasion, metastasis, and poor prognosis in salivary adenoid cystic carcinoma

Background/purposeUpregulation of B-cell specific Moloney murine leukemia virus insertion site 1 (BMI-1) has been involved in the invasion, metastasis, and poor prognosis of many cancers. The aim of this study was to evaluate the levels and clinical significance of BMI-1 in saliva of patients with salivary adenoid cystic carcinoma (SACC), and to analyze biological function and mechanism of BMI-1 in the invasion and metastasis of SACC. Materials and methodsThe levels of BMI-1 in saliva and tumor tissues of SACC patients were determined. The correlation of salivary BMI-1 levels with clinicopathological parameters and clinical outcomes in patients with SACC was analyzed. Additionally, the effects of BMI-1 on wound-healing, transwell invasion, and epithelial-mesenchymal transition (EMT)-related protein expression in vitro as well as on tumorigenicity and experimental lung metastasis in vivo were investigated through exogenous overexpression and silencing of BMI-1 in SACC cells. ResultsBMI-1 levels increased in saliva and tumor tissues in SACC patients with invasion or metastasis. High salivary BMI-1 levels were correlated with poor TNM stage, poor overall survival, and disease-free survival. Exogenous expression of BMI-1 in SACC-83 promoted its migration and invasion, while silencing BMI-1 in SACC-LM inhibited its migration and invasion in vitro and suppressed tumorigenesis and lung metastasis in vivo. Furthermore, BMI-1 regulated the expression of EMT-related proteins in SACC. ConclusionOur study shows that BMI-1 can serve as a valuable biomarker to identify tumor invasion and metastasis in SACC, predict its prognosis, and act as a promising therapeutic target for SACC.

CDK12 alterations and ARID1A mutations are predictors of poor prognosis and therapeutic targets in high-grade salivary gland carcinoma: analysis of the National Genomic Profiling Database.

Due to the diversity of histopathologic types in salivary gland carcinoma, genomic analysis of large cohorts with next-generation sequencing by histologic type has not been adequately performed. We analysed data from 93 patients with salivary duct carcinoma and 243 patients with adenoid cystic carcinoma who underwent comprehensive genomic profiling testing in the Center for Cancer Genomics and Advanced Therapeutics database, a Japanese national genome profiling database. We visualised gene mutation profiles using the OncoPrinter platform. Fisher's exact test, Kaplan-Meier analysis, log-rank test and Cox regression models were used for statistical analysis. In salivary duct carcinoma, a population with CDK12 and ERBB2 co-amplification was detected in 20 of 37 (54.1%) patients with ERBB2 amplification. We identified five loss-of-function variants in genes related to homologous recombination deficiency, such as BRCA2 and CDK12. Cox survival analysis showed that CDK12 and ERBB2 co-amplification is associated with overall survival (hazard ratio, 3.597; P=0.045). In salivary duct carcinoma, NOTCH1 mutations were the most common, followed by mutations in chromatin modification genes such as KMT2D, BCOR, KDM6A, ARID1A, EP300 and CREBBP. In the multivariate Cox analysis, activating NOTCH1 mutations (hazard ratio, 3.569; P=0.009) and ARID1A mutations (hazard ratio, 4.029; P=0.034) were significantly associated with overall survival. CDK12 and ERBB2 co-amplification is associated with a poor prognosis in salivary duct carcinoma. Chromatin remodelling genes are deeply involved in tumour progression in adenoid cystic carcinoma. One such gene, ARID1A, was an independent prognostic factor. In salivary duct carcinoma and adenoid cystic carcinoma, there might be minor populations with mutations that could be targeted for treatment with the synthetic lethality approach.

MiR-200b-5p inhibits tumor progression in salivary adenoid cystic carcinoma via targeting BTBD1

Salivary adenoid cystic carcinoma (SACC) is a rare malignant tumor of the salivary gland. Studies have suggested that miRNA may play a crucial role in the invasion and metastasis of SACC. This study aimed to investigate the role of miR-200b-5p in SACC progression. Reverse transcription-quantitative PCR and western blot assay were used to detect the expression levels of miR-200b-5p and BTBD1. The biological functions of miR-200b-5p were evaluated via wound-healing assays, transwell assays, and xenograft nude mice model. The interaction between miR-200b-5p and BTBD1 was assessed using luciferase assay. Results showed that miR-200b-5p was downregulated in the SACC tissues while BTBD1 was upregulated. miR-200b-5p overexpression suppressed SACC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Bioinformatics prediction and luciferase reporter assay revealed that miR-200b-5p could directly bind to BTBD1. Besides, miR-200b-5p overexpression could rescue the tumor-promoting effect of BTBD1. miR-200b-5p inhibited tumor progression by modulating EMT-related proteins, targeting BTBD1 and inhibiting PI3K/AKT signaling pathway. Overall, our findings indicate that miR-200b-5p can suppress SACC proliferation, migration, invasion, and EMT by regulating BTBD1 and PI3K/AKT axis, providing a promising therapeutic target for SACC treatment.

Identification of MicroRNA Expression Profiles Related to the Aggressiveness of Salivary Gland Adenoid Cystic Carcinomas.

Adenoid cystic carcinoma (ACC) has been reported as the second most common carcinoma of the salivary glands. Few studies have associated miRNA expression with ACC aggressiveness. In this study, we evaluated the miRNA profile of formalin-fixed, paraffin-embedded (FFPE) samples of salivary gland ACC patients using the NanoString platform. We studied the miRNA expression levels associated with the solid growth pattern, the more aggressive histologic feature of ACCs, compared with the tubular and cribriform growth patterns. Moreover, the perineural invasion status, a common clinicopathological feature of the disease that is frequently associated with the clinical progression of ACC, was investigated. The miRNAs showing significant differences between the study groups were selected for target prediction and functional enrichment, which included associations with the disease according to dedicated databases. We observed decreased expression of miR-181d, miR-23b, miR-455, miR-154-5p, and miR-409 in the solid growth pattern compared with tubular and cribriform growth patterns. In contrast, miR-29c, miR-140, miR-195, miR-24, miR-143, and miR-21 were overexpressed in patients with perineural invasion. Several target genes of the miRNAs identified have been associated with molecular processes involved in cell proliferation, apoptosis, and tumor progression. Together, these findings allowed the characterization of miRNAs potentially associated with aggressiveness in salivary gland adenoid cystic carcinoma. Our results highlight important new miRNA expression profiles involved in ACC carcinogenesis that could be associated with the aggressive behavior of this tumor type.