Molecular characterization of the salivary adenoid cystic carcinoma immune landscape by anatomic subsites.

Adenoid cystic carcinoma (AdCC) is a slow-growing salivary gland malignancy that relapses frequently. AdCCs of the submandibular gland exhibit unique differences in prognosis and treatment response to adjuvant radiotherapy compared to other sites, yet the role of tumor anatomic subsite on gene expression and tumor immune microenvironment (TIME) composition remains unclear. We used 87 samples, including 48 samples (27 AdCC and 21 normal salivary gland tissue samples) from 4 publicly available AdCC RNA sequencing datasets, a validation set of 33 minor gland AdCCs, and 39 samples from an in-house cohort (30 AdCC and 9 normal salivary gland samples). RNA sequencing data were used for single sample gene set enrichment analysis and TIME deconvolution. Quantitative PCR and multiplex immunofluorescence were performed on the in-house cohort. Wilcoxon rank-sum, nonparametric equality-of-medians tests and linear regression models were used to evaluate tumor subsite differences. AdCCs of different anatomic subsites including parotid, submandibular, sublingual, and minor salivary glands differed with respect to expression of several key tumorigenic pathways. Among the three major salivary glands, the reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (NRF2) pathway signature was significantly underexpressed in AdCC of submandibular compared to parotid and sublingual glands while this association was not observed among normal glands. Additionally, the NRF2 pathway, whose expression was associated with favorable overall survival, was overexpressed in AdCCs of parotid gland compared to minor and submandibular glands. The TIME deconvolution identified differences in CD4+ T cell populations between AdCC of major and minor glands and natural killer (NK) cells among AdCC of minor, submandibular, and parotid glands while plasma cells were enriched in normal submandibular glands compared to other normal gland controls. Our data reveal key molecular differences in AdCC of different anatomic subsites. The ROS and NRF2 pathways are underexpressed in submandibular and minor AdCCs compared to parotid gland AdCCs, and NRF2 pathway expression is associated with favorable overall survival. The CD4+ T, NK, and plasma cell populations also vary by tumor subsites, suggesting that the observed submandibular AdCC tumor-intrinsic pathway differences may be responsible for influencing the TIME composition and survival differences.

A Novel Scoring System for MYB RNA In Situ Hybridization Displays High Sensitivity and Specificity for Adenoid Cystic Carcinoma in a Clinical Setting.

BACKGROUND: MYB RNA in situ hybridization (ISH) has emerged as a reliable and accessible marker to support adenoid cystic carcinoma (ACC) diagnosis, though still not well studied. Here, we report our results in a validation and prospective cohort to improve MYB RNA ISH diagnostic accuracy. METHODS: 79 cases (23 retrospective and 56 prospective) underwent MYB RNA ISH testing (44 ACC and 35 non-ACC). MYB RNA ISH results were initially interpreted based on previously established (original) scoring criteria. Weighted "i-scores", percent positive tumor cells, percent tumor cells with large signals (% LS), and staining pattern (abluminal, diffuse, focal non-patterned, or negative) were inputs for logistic regression models. Final model performance characteristics were compared with original scoring criteria and MYB::NFIB FISH results. RESULTS: An abluminal pattern was characteristic and exclusive to ACC. All i-scores, % LS, and percent positive were significantly higher in ACC. Original scoring criteria yielded a 95.5% sensitivity (Sn), 68.6% specificity (Sp), and 83.5% accuracy. MYB::NFIB FISH yielded a 42.9% sensitivity, 100% specificity, and 60% accuracy. Optimizing for performance, simplicity, and minimal collinearity, our final model was defined as: abluminal pattern and/or % LS > 16.5%, which resulted in a 93.2% Sn, 97.1% Sp, and 94.9% accuracy for ACC diagnosis. False negatives included an ACC with striking tubular eosinophilia and a MYBL1::NFIB translocated ACC. One false positive exclusive to the final model was a nasopharyngeal carcinoma with MYB amplification. CONCLUSIONS: MYB RNA ISH has a higher Sn than MYB::NFIB FISH while retaining high Sp. Our model provides improvements to specificity compared to original scoring criteria and highlight the importance of abluminal staining pattern and % LS. Nonetheless, alternate fusions remain key false negatives while rare non-ACC with other mechanisms of MYB activation may present as false positives.

Comprehensive genomic profiling of salivary gland carcinoma: Analysis of the Center for Cancer Genomics and Advanced Therapeutics database in Japan.

Comprehensive information on genetic alterations in salivary gland cancer (SGC) is limited. This study aimed to elucidate the genetic and clinical characteristics of patients with SGC using the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, a Japanese national genomic database. We analyzed data of 776 patients with SGC registered in the C-CAT database between June 1, 2019, and June 30, 2023. Adenoid cystic carcinoma was the most common histologic type, followed by salivary duct carcinoma (SDC) and adenocarcinoma not otherwise specified. Genetic data of 681 patients receiving FoundationOne® CDx were analyzed. We identified specific features of the combination of TP53 and CDKN2A alterations among the histological types. Specific LYN amplification was mainly detected in carcinoma ex pleomorphic adenoma and myoepithelial carcinoma. For SDC, the frequency of ERBB2 and BRAF alterations were higher in cases with metastatic lesions than in those with primary lesions. Although 28.6% patients were offered recommended treatment options, only 6.8% received the recommended treatments. This study highlights the differences in genetic alterations among the histological types of SGC, with comprehensive genomic profiling tests revealing lower drug accessibility. These findings could contribute to the development of personalized treatment for patients with SGC.

TGFß signaling pathway in salivary gland tumors.

OBJECTIVE: Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFß signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFß signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFß cascade. DESIGN: Thirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR. RESULTS: Cases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFß signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC. CONCLUSIONS: Our study demonstrated the differential expression of TGFß cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

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

PURPOSE: To explore the role and mechanism of heat shock protein 27 (HSP27) in SACC VM formation. STUDY DESIGN: Immunohistochemistry 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 3-dimensional culture. RESULTS: HSP27 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. CONCLUSION: HSP27 may plays an important role in VM formation in SACC via the AKT-MMP-2/9 signalling pathway.

Molecular Profiling and the Impact of Treatment on Outcomes in Adenoid Cystic Carcinoma Type I and II.

PURPOSE: Adenoid cystic carcinoma (ACC) is an uncommon salivary gland cancer with no approved therapies available to treat advanced, incurable disease. Recent molecular profiling efforts have identified two important subtypes: the more aggressive ACC-I is characterized by Notch pathway alterations and MYC amplification whereas ACC-II demonstrates a more indolent phenotype and TP63 overexpression. EXPERIMENTAL DESIGN: This retrospective observational cohort study involved de-identified samples from 438 patients with ACC with tumor samples sent for commercially-available molecular profiling (Caris Life Sciences). Next-generation whole-exome and whole-transcriptomic sequencing was performed on primary and metastatic samples. Immunostaining for PD-L1 and RNA deconvolution (quanTIseq) was used to explore the tumor immune microenvironment (TME). Real-world clinical and survival outcome metrics were extracted from insurance claims data. RESULTS: MYC expression was 1.61-fold higher (39.8 vs. 24.7; P < 0.0001) among NOTCH1-mutant ACC-I tumors, whereas MYB/L1 fusion rates were similar among ACC-I/II. The median B-cell fraction in the TME was higher among ACC-II (7.1% vs. 5.8%; P < 0.01), although infiltrating T cells subsets were low among either ACC subgroup (both <1%). When pooling systemic treatment categories, ACC-I patients had worse outcomes with available therapies (HR, 3.06; 95% confidence interval, 1.65-5.68; P < 0.01), with no significant difference in overall survival between ACC-I/II based on chemotherapy or VEGFR tyrosine kinase inhibitor exposure in smaller subsets. CONCLUSIONS: We confirmed the previously reported associations with MYC and TP63 in the prognostically relevant subgroups of ACC-I and -II, respectively, and report immunologic differences among these subtypes. Survival outcomes are comparatively worse in ACC-I regardless of treatment type.

Adenoid cystic carcinoma of the Bartholin's gland is underpinned by MYB- and MYBL1- rearrangements.

OBJECTIVE: Adenoid cystic carcinoma (AdCC) of the Bartholin's gland (AdCC-BG) is a very rare gynecologic vulvar malignancy. AdCC-BGs are slow-growing but locally aggressive and are associated with high recurrence rates. Here we sought to characterize the molecular underpinning of AdCC-BGs. METHODS: AdCC-BGs (n = 6) were subjected to a combination of RNA-sequencing, targeted DNA-sequencing, reverse-transcription PCR, fluorescence in situ hybridization (FISH) and MYB immunohistochemistry (IHC). Clinicopathologic variables, somatic mutations, copy number alterations and chimeric transcripts were assessed. RESULTS: All six AdCC-BGs were biphasic, composed of ductal and myoepithelial cells. Akin to salivary gland and breast AdCCs, three AdCC-BGs had the MYB::NFIB fusion gene with varying breakpoints, all of which were associated with MYB overexpression by IHC. Two AdCC-BGs were underpinned by MYBL1 fusion genes with different gene partners, including MYBL1::RAD51B and MYBL1::EWSR1 gene fusions, and showed MYB protein expression. Although the final AdCC-BG studied had MYB protein overexpression, no gene fusion was identified. AdCC-BGs harbored few additional somatic genetic alterations, and only few mutations in cancer-related genes were identified, including GNAQ, GNAS, KDM6A, AKT1 and BCL2, none of which were recurrent. Two AdCC-BGs, both with a MYB::NFIB fusion gene, developed metastatic disease. CONCLUSIONS: AdCC-BGs constitute a convergent phenotype, whereby activation of MYB or MYBL1 can be driven by the MYB::NFIB fusion gene or MYBL1 rearrangements. Our observations further support the notion that AdCCs, irrespective of organ site, constitute a genotypic-phenotypic correlation. Assessment of MYB or MYBL1 rearrangements may be used as an ancillary marker for the diagnosis of AdCC-BGs.

Novel Epigenetic Modifiers of Histones Presenting Potent Inhibitory Effects on Adenoid Cystic Carcinoma Stemness and Invasive Properties.

Adenoid cystic carcinoma (ACC) is a rare neoplasm known for its indolent clinical course, risk of perineural invasion, and late onset of distant metastasis. Due to the scarcity of samples and the tumor's rarity, progress in developing effective treatments has been historically limited. To tackle this issue, a high-throughput screening of epigenetic drugs was conducted to identify compounds capable of disrupting the invasive properties of the tumor and its cancer stem cells (CSCs). ACC cells were screened for changes in tumor viability, chromatin decondensation, Snail inhibition along tumor migration, and disruption of cancer stem cells. Seven compounds showed potential clinical interest, and further validation showed that Scriptaid emerged as a promising candidate for treating ACC invasion. Scriptaid demonstrated a favorable cellular toxicity index, effectively inhibited Snail expression, induced hyperacetylation of histone, reduced cell migration, and effectively disrupted tumorspheres. Additionally, LMK235 displayed encouraging results in four out of five validation assays, further highlighting its potential in combating tumor invasion in ACC. By targeting the invasive properties of the tumor and CSCs, Scriptaid and LMK235 hold promise as potential treatments for ACC, with the potential to improve patient outcomes and pave the way for further research in this critical area.

[Correlation of MYB/NFIB gene fusion with the grade and prognosis of head and neck adenoid cystic carcinoma and the concordance of two detection methods].

Objective: To explore the correlation between MYB/NFIB gene fusion and clinicopathological features such as tumor grade and prognosis of head and neck adenoid cystic carcinoma (ACC), and to assess the concordant rate of fluorescent in situ hybridization (FISH) with MYB and NFIB immunohistochemistry. Methods: FISH detection of MYB/NFIB gene fusion was performed on 48 head and neck ACC cases and 15 non-ACC salivary gland tumors at National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China during April 2014 and January 2020. ACC cases were divided into grade Ⅰ-Ⅱ, grade Ⅲ and high-grade transformation, according to pathological grading criteria. Prognosis, FISH results and other clinicopathological characteristics were analyzed. MYB and NFIB immunohistochemistry was performed on the 48 ACC and 15 non-ACC cases. The diagnostic accuracy of FISH and immunohistochemistry was compared. Results: FISH detected MYB/NFIB gene fusion in 41.7% (20/48) of the ACC. Its positive rate was inversely correlated with higher pathological grades (P=0.036). The higher histological grade was linked to worse progression-free survival (P=0.024), whereas there was no correlation between the status of gene fusion detected by FISH and progression-free survival (P=0.536). FISH didnot detect MYB/NFIB gene fusion in 15 non-ACC salivary gland tumors The specificity of diagnosing ACC is 100% for both FISH detection of gene fusion and immunohistochemical detection of MYB expression. However, the sensitivity for both methods was only about 41.7%, respectively. By combining FISH and MYB immunohistochemistry, the sensitivity for diagnosing ACC was increased to 66.7%. Conclusions: MYB/NFIB gene fusion has a lower detection rate in grade Ⅲ ACC and high-grade transformation ACC. Meanwhile gene fusion status is not correlated with prognosis. The sensitivity for diagnosing ACC can be improved by combining FISH and MYB immunohistochemistry.

Solid basal adenoid cystic carcinoma of the breast: A case report and literature review.

RATIONALE: Adenoid cystic carcinoma (AdCC) is a rare malignancy of the breast with a low Ki-67 index and good prognosis. Owing to the rarity of breast AdCC, the misdiagnosis rate is as high as 50%, and there is no consensus or recognized guidelines for the treatment of this disease. Therefore, it is necessary to conduct a detailed clinical and pathological analysis in combination with a literature review to improve our understanding, diagnosis, and treatment of the disease. METHODS: A 68-year-old woman sought medical attention due to a recently increasing mass in the breast. The left breast mass was 1.3 cm × 1 cm in size. We analyzed the morphology, immunohistochemistry, and molecular characteristics of the tumor removed by surgery, and reviewed relevant literature. DIAGNOSES: Solid basal AdCC of the breast. INTERVENTIONS: We performed biopsy, immunohistochemistry and molecular testing on surgical resection specimens. OUTCOMES: Combining morphological and immunohistochemical features, it is consistent with solid basal AdCC of the breast, and Fish detected MYB gene break. LESSONS: Due to the high misdiagnosis rate of AdCC, accurate histopathological diagnosis is particularly important. At present, breast conserving surgery and local tumor resection are mainly used for the treatment of breast AdCC, and postoperative adjuvant radiotherapy is feasible.

A phase 2 study of MK-2206 in patients with incurable adenoid cystic carcinoma (Alliance A091104).

BACKGROUND: Recurrent/metastatic adenoid cystic carcinoma (ACC) is a rare, incurable disease. MYB is a putative oncogenic driver in ACC that is often overexpressed through an MYB-NFIB rearrangement. The authors hypothesized that AKT inhibition with the allosteric inhibitor MK-2206 could decrease MYB expression and induce tumor regression in patients with incurable ACC (ClinicalTrials.gov identifier NCT01604772). METHODS: Patients with progressive, incurable ACC were enrolled and received MK-2206 150 mg weekly; escalation to 200 mg was allowed. The primary end point was confirmed response. Secondary end points were progression-free survival, overall survival, and safety. An exploratory analysis evaluating the effect of MK-2206 on MYB expression was conducted in a subset of patients. RESULTS: Sixteen patients were enrolled, and 14 were evaluable for efficacy. No confirmed responses were observed. Thirteen patients had stable disease, and one had disease progression as their best response. The median progression-free survival was 9.7 months (95% CI, 3.8-11.8 months), and the median overall survival was 18.0 months (95% CI, 11.8-29.9 months). Nine of 16 patients (56%) had at least one grade 3 treatment-related adverse event, and the most common were rash (38%), fatigue (19%), decreased lymphocyte count (13%), and hyperglycemia (13%). Twelve of 14 tumors (86%) had detectable MYB expression by immunohistochemistry, and seven of 14 tumors (50%) had an MYB-NFIB gene rearrangement. Serial biopsies revealed decreased MYB levels with MK-2206 in four of five patients. CONCLUSIONS: MK-2206 failed to induce clinical responses in patients with incurable ACC. AKT inhibition may diminish MYB protein levels, although the effect was highly variable among patients. Novel approaches to target MYB in ACC are needed.

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.

Current diagnosis and treatment of salivary gland-type tumors of the lung.

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

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.

The mitotic checkpoint kinase BUB1 is a direct and actionable target of MYB in adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a head and neck cancer that frequently originates in salivary glands, but can also strike other exocrine glands such as the breast. A key molecular alteration found in the majority of ACC cases is MYB gene rearrangements, leading to activation of the oncogenic transcription factor MYB. In this study, we used immortalised breast epithelial cells and an inducible MYB transgene as a model of ACC. Molecular profiling confirmed that MYB-driven gene expression causes a transition into an ACC-like state. Using this new cell model, we identified BUB1 as a targetable kinase directly controlled by MYB, whose pharmacological inhibition caused MYB-dependent synthetic lethality, growth arrest and apoptosis of patient-derived cells and organoids.

Primary pulmonary adenoid cystic carcinoma: A clinicopathological study of 64 patients.

BACKGROUND: This study aimed to investigate the clinicopathological features and prognostic indicators of primary pulmonary adenoid cystic carcinoma (PACC). METHODS: Clinical data were collected from 64 primary PACC patients and analyzed retrospectively at the Tianjin Medical University General Hospital, the West China Hospital of Sichuan University, the First Affiliated Hospital of Guangxi Medical University, and the Bishan Hospital of Chongqing Medical University from January 2003 to August 2023. The 64 patients (28 males and 36 females) were aged from 20 to 73 years, with a median age of 49 years and an average age of 49.3 years. RESULTS: Immunohistochemical staining showed that the tumors expressed CK7, S-100 protein, CK5/6, CD117, and p63. Seven patients underwent fluorescence in situ hybridization (FISH) testing and three were found to have myeloblastosis (MYB) gene translocation. In total, 53 patients underwent surgery, among whom 31 received only surgery and 22 received both surgery and postoperative chemoradiotherapy. In addition, 10 patients received chemoradiotherapy only, while one patient underwent treatment with traditional Chinese medicine. The overall survival rates in the first, third, and fifth years were 98.4%, 95.3%, and 87.5%, respectively. CONCLUSION: Prognostic analysis revealed that age, tumor size, lymph node metastasis status, margin status, and choice of treatment modality significantly influenced the patients' prognosis.

Diagnosis of Adenoid Cystic Carcinoma with Striking Tubular Hypereosinophilia by MYB and EWSR1 Breakapart Fluorescence In Situ Hybridization.

BACKGROUND: Adenoid cystic carcinoma (AdCC), associated with MYB/MYBL1 gene rearrangements, shows epithelial and basaloid myoepithelial cells arranged in tubular, cribriform and solid patterns. Variations from this classic morphology make diagnosis challenging, necessitating molecular testing. AdCC with striking tubular hypereosinophilia (AdCC-STE) is one such recently described histological subtype. METHODS: A 52-year-old female presented with a floor of mouth swelling for two months, diagnosed elsewhere as polymorphous adenocarcinoma (PAC). A biopsy was obtained. With a diagnosis of oncocytic neoplasm, wide excision of the tumor was undertaken. Histological examination, fluorescence in situ hybridization (FISH) and ultrastructural examination were performed. Archival cases of PAC and epithelial myoepithelial carcinoma (EMC) were reviewed, and MYB immunostaining and FISH were performed to identify potential AdCC-STE cases. RESULTS: The excised tumor from the index patient showed bilayered tubules, micropapillae and cribriform pattern. Luminal cells with hypereosinophilic to clear cytoplasm were surrounded by flattened abluminal cells. Focally, basophilic matrix was seen within sharply demarcated pseudocystic spaces. FISH revealed MYB and EWSR1 gene rearrangements, confirmatory of AdCC-STE. Electron microscopy showed features consistent with AdCC; however, mitochondria were not prominent. Among 14 archival PACs, two showed MYB immunopositivity; one showed MYB rearrangement but was classical AdCC. Among 35 EMC, one case showed MYB immunoreactivity and eosinophilia of luminal cells but lacked MYB/MYBL1 rearrangement. CONCLUSION: Awareness of unusual histological subtypes of AdCC, such as AdCC-STE, is imperative, as it may be misdiagnosed as PAC and EMC, among others. Presence of basophilic matrix and squamoid morules in a biphasic tumor even with hypereosinophilic rather than basaloid myoepithelial appearance should raise suspicion for AdCC-STE, and prompt molecular testing for confirmation. With wider accessibility, lower cost and significantly shorter turn-around-time when compared to RNA sequencing, FISH can be employed for confirmation of diagnosis, especially in low- and middle-income countries.

Induction of perineural invasion in salivary adenoid cystic carcinoma by circular RNA RNF111

Objective Local recurrence, distant metastasis, and perineural invasion (PNI) viciously occur in salivary adenoid cystic carcinoma (SACC), resulting in a poor prognosis. This study aimed to explore the mechanism by which circular RNA RNF111 (circ-RNF111) regulates PNI in SACC by targeting the miR-361-5p/high mobility group box 2 (HMGB2) axis. Method Circ-RNF111 and HMGB2 were highly expressed in SACC specimens, while miR-361-5p was underexpressed. Functional experiments showed that ablating circ-RNF111 or promoting miR-361-5p hindered the biological functions and PNI of SACC-LM cells. Results HMGB2 overexpression induced the reversal of SACC-LM cell biological functions and PNI caused by circ-RNF111 knockout. Furthermore, reduction of circ-RNF111 suppressed PNI in a SACC xenograft model. Circ-RNF111 regulated HMGB2 expression through targeted modulation of miR-361-5p. Conclusion Taken together, circ-RNF111 stimulates PNI in SACC by miR-361-5p/HMGB2 axis and may serve as a potential therapeutic target for SACC (AU)

Extracting Potential New Targets for Treatment of Adenoid Cystic Carcinoma using Bioinformatic Methods.

Background: Adenoid cystic carcinoma is a slow-growing malignancy that most often occurs in the salivary glands. Currently, no FDA-approved therapeutic target or diagnostic biomarker has been identified for this cancer. The aim of this study was to find new therapeutic and diagnostic targets using bioinformatics methods. Methods: We extracted the gene expression information from two GEO datasets (including GSE59701 and GSE88804). Different expression genes between adenoid cystic carcinoma (ACC) and normal samples were extracted using R software. The biochemical pathways involved in ACC were obtained by using the Enrichr database. PPI network was drawn by STRING, and important genes were extracted by Cytoscape. Real-time PCR and immunohistochemistry were used for biomarker verification. Results: After analyzing the PPI network, 20 hub genes were introduced to have potential as diagnostic and therapeutic targets. Among these genes, PLCG1 was presented as new biomarker in ACC. Furthermore, by studying the function of the hub genes in the enriched biochemical pathways, we found that insulin-like growth factor type 1 receptor and PPARG pathways most likely play a critical role in tumorigenesis and drug resistance in ACC and have a high potential for selection as therapeutic targets in future studies. Conclusion: In this study, we achieved the recognition of the pathways involving in ACC pathogenesis and also found potential targets for treatment and diagnosis of ACC. Further experimental studies are required to confirm the results of this study.

Solid-Basaloid Adenoid Cystic Carcinoma of the Breast: An Aggressive Subtype Enriched for Notch Pathway and Chromatin Modifier Mutations With MYB Overexpression.

Adenoid cystic carcinoma (AdCC) is a rare triple-negative breast cancer analogous to its extramammary counterparts. Diagnosis of the more aggressive solid-basaloid variant of AdCC (SB-AdCC) can be challenging due to poorly defined histopathologic and molecular features. We characterized 22 invasive and in situ basaloid carcinomas by morphology, immunohistochemistry, genetics, and MYB status using multiple platforms and assessed clinical behavior and neoadjuvant chemotherapy responses. After consensus review, 16/22 cases were classified as SB-AdCC. All SB-AdCC had predominantly solid growth and at least focal myxohyaline stroma and were immune-poor. Eosinophilic squamoid cells (69%, 11/16) and basement membrane-like secretions (69%, 11/16) were common, and intercalated ducts (31%, 5/16) were less frequent. SB-AdCC typically expressed SOX10 (100%, 16/16) and luminal markers (100%, 16/16 CK7; 88%, 14/16 CD117; 93%, 13/14 CAM5.2). SMA (40%, 6/15) expression was less common, and SMM (27%, 3/11), GATA3 (20%, 3/15), and p63 (25%, 4/16) were mostly negative. MYB protein and/or MYB RNA overexpression was universal in evaluable cases (13/13), with RNA in situ hybridization (10/10) more reliable than immunohistochemistry (10/11, plus 4 excisions inconclusive). Fluorescence in situ hybridization and/or next-generation sequencing identified MYB rearrangements (20%, 3/15) and amplifications/copy gains (60%, 9/15) but no MYB::NFIB fusions. SB-AdCC often had aberrations in Notch pathway (60%, including 40% NOTCH1 and 20% NOTCH2) and/or chromatin modifier (60%, including 33% CREBBP) genes, with relatively infrequent TP53 mutations (27%). Unclassified invasive basaloid carcinomas lacking described histologic features of SB-AdCC (n = 4) and basaloid ductal carcinoma in situ (n = 2) showed similar immunoprofiles and genetics as SB-AdCC, including Notch aberrations and MYB overexpression with MYB rearrangements/amplifications. Overall, nodal (22%) and distant (33%) metastases were common, and 23% of patients died of disease (mean follow-up, 35 months; n = 22). Responses were poor in all 7 neoadjuvant chemotherapy-treated patients, without any achieving pathologic complete response. The data highlight the histopathologic spectrum of basaloid carcinomas including SB-AdCC and reveal shared genetics and MYB activation, which can be diagnostically useful. Aggressive behavior and poor treatment responses emphasize a need for additional treatment approaches.