Prognostic significance of p53 immunohistochemical expression in adenoid cystic carcinoma of the salivary glands: a meta-analysis

Molecular Aspects of Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of the Salivary Gland

BACKGROUND

Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs.

METHODS

We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma.

RESULTS

Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis.

CONCLUSIONS

Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

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.

CCL25/CCR9 interaction promotes the malignant behavior of salivary adenoid cystic carcinoma via the PI3K/AKT signaling pathway

Background

CC chemokine receptor 9 (CCR9), an organ-specific chemokine receptor, interacts with its exclusive ligand CCL25 to promote tumor proliferation and metastasis. However, the effect of CCR9 on salivary adenoid cystic carcinoma (SACC) malignant behavior remains unknown. This study aimed to investigate the specific molecular mechanism by which CCR9/CCL25 modulates malignant progression in SACC.

Methods

Immunohistochemistry staining and RT-qPCR analyses were performed to detect the correlation of CCR9 expression and tumor progression-associated markers in SACC. In vitro, SACC cell proliferation and apoptosis were evaluated using Cell Counting Kit-8 and colon formation, and cell migration and invasion were detected by wound healing and transwell assays. Vercirnon was used as an inhibitor of CCR9, and LY294002 was used as an inhibitor of the PI3K/AKT pathway in this study. Western blot and RT-qPCR assays were carried out to measure the downstream factors of the interaction of CCL25 and CCR9. The effect of CCL25 on the development of SACC in vivo was examined by a xenograft tumor model in nude mice following CCL25, Vercirnon and LY294002 treatment.

Results

CCR9 was highly expressed in SACC compared with adjacent salivary gland tissues, and its level was associated with tumor proliferation and metastases. CCL25 enhanced cell proliferation, migration, and invasion through its interaction with CCR9 and exerted an antiapoptotic effect on SACC cells. Targeting CCR9 via Vercirnon significantly reduced the phosphorylation level of AKT induced by CCL25. CCL25/CCR9 could activate its downstream factors through the PI3K/AKT signaling pathway, such as cyclin D1, BCL2 and SLUG, thus promoting SACC cell proliferation, antiapoptosis, invasion and metastasis. The in vivo data from the xenograft mouse models further proved that CCL25 administration promoted malignant tumor progression by activating the PI3K/AKT pathway.

Conclusion

The interaction of CCL25 and CCR9 promotes tumor growth and metastasis in SACC by activating the PI3K/AKT signaling pathway, offering a promising strategy for SACC treatment.

Mutually Exclusive Expression of COL11A1 by CAFs and Tumour Cells in a Large panCancer and a Salivary Gland Carcinoma Cohort

Procollagen 11A1 (COL11A1) is a central component of the extracellular matrix in many carcinomas, which is considered to be mainly produced by cancer associated fibroblasts (CAFs). As COL11A1 expression correlates with adverse prognosis and is implicated in chemoresistance, it is a promising putative target. For the first time, we used RNA in-situ hybridization to systematically identify the cells that produce COL11A1 in the ten most prevalent carcinoma types, lymphomas (n = 275) and corresponding normal tissue (n = 55; panCancer cohort). Moreover, as most salivary gland carcinomas (SGC) display distinct stromal architectures, we also analysed 110 SGC. The corresponding protein formation of COL11A1 was determined by MALDI-TOF-MS-Imaging. We report that colon, breast and salivary duct carcinomas are highly infiltrated by COL11A1 positive CAFs (CAFs_COL11A1) and might thus be promising candidates for antidesmoplastic or COL11A1-targeted therapies. The amount of CAFs_COL11A1 correlated significantly with tumour grade, tumour stage and nodal spread in the panCancer cohort. Significant associations between CAFs_COL11A1 and vascular invasion, perineural spread and nodal spread were observed in the SGC cohort. Also, we discovered that tumour cells of intercalated duct derived SGC and CAFs produce COL11A1 in a mutually exclusive manner. Our findings represent a novel mode of extracellular matrix production in carcinomas and could be highly relevant in the future. Our findings elucidate the mode of COL11A1 expression in very different carcinoma types and may aid to categorise tumours in the setting of possible future COL11A1-related therapies.

High-Grade Transformation in Adenoid Cystic Carcinoma of the Bartholin Gland: Case Report

Introduction In the present study, we report a case of primary adenoid cystic carcinoma (ACC) of the Bartholin gland with high-grade transformation (HGT). Adenoid cystic carcinoma of the Bartholin gland is a rare tumor and HGT has only been reported in head and neck tumors.

Case Report A 77-year-old woman with a non-ulcerated vulvar lesion on the topography of the right Bartholin gland. The patient was submitted to tumor resection followed by V–Y island flap and adjuvant radiotherapy. The histopathological examination revealed primary ACC of the Bartholin gland, with areas of HGT and extensive perineural invasion. The immunohistochemical study with p53 showed a diffuse and strong positive reaction in areas with HGT. After 24 months of follow-up, the patient presented distant metastases and died, despite having undergone to chemotherapy.

Conclusion As far as we know, this case is the first description in the literature of HGT in ACC of the Bartholin gland, and HGT appears to be associated with tumor aggressiveness.

Quantitative ubiquitylomics reveals the ubiquitination regulation landscape in oral adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is an extremely rare salivary gland tumor with a poor prognosis and needs attention on molecular mechanisms. Protein ubiquitination is an evolutionarily conserved post-translational modification (PTM) for substrates degradation and controls diverse cellular functions. The broad cellular function of ubiquitination network holds great promise to detect potential targets and identify respective receptors. Novel technologies are discovered for in-depth research and characterization of the precise and dynamic regulation of ubiquitylomics in multiple cellular processes during cancer initiation, progression and treatment. In the present study, 4D label-free quantitative techniques of ubiquitination proteomics were used and we identified a total of 4152 ubiquitination sites in 1993 proteins. We also performed a systematic bioinformatics analysis for differential modified proteins and peptides containing quantitative information through the comparation between oral ACC (OACC) tumor with adjacent normal tissues, as well as the identification of eight protein clusters with motif analysis. Our findings offered an important reference of potential biomarkers and effective therapeutic targets for ACC.

The Role of MRPL23 Antisense RNA 1 (MRPL23-AS1) in the Pre-Metastatic Microenvironment of Malignancy During the Process of Epithelial-Mesenchymal Transition

We aimed to explore MRPL23-AS1’s role in the pre-metastatic microenvironment of malignancy during epithelial-mesenchymal transition (EMT). Identification and verification of lncRNA-interacting proteins in salivary adenoid cystic carcinoma (SACC) cells were conducted via RNA-pulldown, silver staining, and Western blotting. RIP and RIP-seq were sequentially administered to verify the binding partners of lncRNA. CHIRP was performed to detect the promoter DNA in the downstream of lncRNA-protein complex. Ultimately CHIP-qPCR detected the effects of lncRNA on the binding degree of its interacting protein to the promoter DNA in the downstream genes and the methyla-tion level of histones in the promoter region. The exosomes secreted by different SACC cells were extracted from culture supernatant to measure lncRNA expression via qPCR. MRPL23-AS1 interacted with EZH2 protein and promoted EZH2 binding to E-cadherin gene promoter region along with the H3K27 methylation. MRPL23-AS1 could promote EMT of SACC cells and increase pulmonary vascular endothelial cells permeability via exosomes secretion. MRPL23-AS1 up-regulated VEGFA, while down-regulated E-cadherin and VE-cadherin in endothelial cells. Exosomes rich in MRPL23-AS1 could boost lung metastasis in vivo. MRPL23-AS1 inhibits E-cadherin level and promotes EMT of SACC cells, suggesting that it might be a biomarker and therapeutic target for lung cancer.

Prognosis and management of recurrent and/or metastatic head and neck adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare tumor, usually arising in the salivary gland, accounting for 1% of all head and neck cancers. ACC may have a long-term poor prognosis, as about 40% of radically treated patients will recur locoregionally and up to 60% will develop distant metastasis. Factors influencing risk of recurrence have been well studied, but few data exist about prognostic factors in Recurrent/Metastatic (RM) setting. Moreover, treatment of RM ACC is often a challenge for clinicians, in the context of a rare disease, which may have an indolent clinical behavior or less frequently a quicker growth and with a paucity of available clinical trials. This review critically analyzes pathological and molecular prognostic factors in RM ACC and make an overview on actual therapeutic choices and future direction of therapy. Recognized prognostic factors in RM ACC are the presence and site of distant metastasis (lung vs other), the presence of nodal metastasis and of extranodal extension, skull base recurrence, disease free interval, lymphovascular invasion, solid histotypes and grading of disease, and the presence of mutation of NOTCH1 family, PI3K, and TP53. Due to disappointing results with chemotherapy, new approaches are under study, also on the basis of biomolecular research. Ongoing clinical trials are evaluating treatment targeting MYB and NOTCH1 alterations, immunotherapy or combination of targeted treatments and immune checkpoint inhibitors.

Adenoid cystic carcinoma of the salivary gland metastasizing to the pericardium and diaphragm: Report of a rare case

BACKGROUND

Adenoid cystic carcinoma (AdCC) is an uncommon malignancy of the salivary gland characterized by slow growth, increased risk of recurrence and poor prognosis. The annual incidence in the United States is approximately 1200 cases per year and rarely involves the body cavities.

CASE PRESENTATION

We present a case of a 48-year-old male diagnosed with AdCC of the left submandibular gland. He received his last chemotherapy in 2006 and presented with pleural metastasis. After undergoing pleurectomy and decortication procedure, pericardial fluid and biopsies from the chest wall, sixth rib, diaphragm, pleural cavity and pericardium were sent for pathologic evaluation. A diagnosis of metastatic adenoid cystic carcinoma was confirmed, including in the pericardium, pericardial fluid and diaphragm.

CONCLUSION

AdCC of the submandibular gland is a malignant tumor with a high mortality rate. It is very rare for AdCC to metastasize to the pericardium and diaphragm. Metastasis to uncommon sites such as seen in our case with metastases to the pericardium and diaphragm shows the aggressive and unpredictable nature of this tumor, requiring close follow up, and indicating the need for molecular profile analysis and biomarker-stratified clinical trials.

Sympathetic innervation contributes to perineural invasion of salivary adenoid cystic carcinoma via the β2-adrenergic receptor

Purpose

Perineural invasion (PNI) is reported to correlate with local recurrence and poor prognosis of salivary adenoid cystic carcinoma (SACC). However, the pathogenesis of PNI remains unclear. The aims of this study were to investigate the correlation between sympathetic innervation and SACC PNI and to elucidate how the sympathetic neurotransmitter norepinephrine (NE) regulates the PNI process.

Materials and methods

Sympathetic innervation and β2-adrenergic receptor (β2-AR) expression in SACC tissues were evaluated by immunohistochemistry. The NE concentrations in SACC tissues and dorsal root ganglia (DRG) coculture models were measured by ELISA. β2-AR expression in SACC cells was detected by performing quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescence assay. SACC cells were treated with NE, the nonselective α-AR blocker phentolamine, the β2-AR antagonist ICI118,551, or were transfected with β2-AR small interfering RNA (siRNA). Proliferation was evaluated in methyl thiazolyl tetrazolium assay, and migration was evaluated in Transwell assay and wound-healing assay. PNI was tested through both Transwell assay and a DRG coculture model. The expressions of epithelial–mesenchymal transition (EMT) markers and matrix metalloproteinases (MMPs) were measured by performing qRT-PCR and Western blot assay.

Results

Sympathetic innervation and β2-AR were highly distributed in SACC tissues and correlated positively with PNI (P=0.035 and P=0.003, respectively). The sympathetic neurotransmitter NE was overexpressed in SACC tissues and DRG coculture models. Exogenously added NE promoted proliferation, migration, and PNI of SACC cells via β2-AR activation. NE/β2-AR signaling may promote proliferation, migration, and PNI by inducing EMT and upregulating MMPs. However, β2-AR inhibition with either an antagonist or siRNA abrogated NE-induced PNI.

Conclusion

Collectively, our findings reveal the supportive role of sympathetic innervation in the pathogenesis of SACC PNI and suggest β2-AR as a potential therapeutic target for treating PNI in SACC.

Ataxia-Telangiectasia-Mutated Protein Expression as a Prognostic Marker in Adenoid Cystic Carcinoma of the Salivary Glands

PURPOSE

Adenoid cystic carcinoma (ACC) is a high-grade malignant tumor of the salivary glands, clinically characterized by multiple recurrences and late distant metastasis. Biological markers for assessing the prognosis of ACC have remained elusive. The purpose of this study was to investigate whether the protein expressions of ataxia telangiectasia mutated (ATM), p53, and ATM-mediated phosphorylated p53 are related to patient survival in ACC.

MATERIALS AND METHODS

In this study, 48 surgical samples were used to assess the expressions of ATM and its downstream target p53. Fisher's exact test and Kaplan-Meier analysis were conducted to evaluate the role of ATM, p53, and phospho-p53 (S15) protein expressions in predicting patient survival and distant metastasis.

RESULTS

Myb expression was positive in 85.4% of ACCs, but did not reflect patient survival rate. In contrast, low expression of ATM in cancer cells was significantly correlated with poor survival rate (p=0.037). Moreover, under positive p53 expression, low expression of ATM was highly predictive of poor survival in ACC (p=0.017).

CONCLUSION

These data indicate that combined assessment of ATM and p53 expression can serve as a useful prognostic marker for assessing survival rate in patients with ACC of the salivary glands.

The CCL5/CCR5 Chemotactic Pathway Promotes Perineural Invasion in Salivary Adenoid Cystic Carcinoma

PURPOSE

Perineural invasion (PNI) is a hallmark of salivary adenoid cystic carcinoma (SACC) and represents an important risk factor for local recurrence and poor survival. However, the mechanism of PNI has yet to be explored. We sought to examine the CCL5-CCR5 ligand-receptor interaction between nerves and SACC cells.

MATERIALS AND METHODS

CCL5/CCR5 expression was determined by immunohistochemistry in SACC tissue specimens. The correlations between CCL5/CCR5 expression and clinicopathologic features were investigated. Dorsal root ganglia (DRG) and SACC cells cocultured in vitro were used to evaluate the effects of CCL5/CCR5 on PNI progression and pathogenesis.

RESULTS

CCR5 expression was significantly elevated in SACC tissues and associated with distant metastasis, PNI, and TNM grade (P < .05). DRG and SACC cells cocultured in vitro showed that the activation of the CCL5/CCR5 axis significantly increased SACC cell invasion and promoted the outgrowth of the DRG. SACC cell lines expressing CCR5 migrated in response to CCL5 derived from DRG, eventually leading to PNI. More importantly, further study showed that blocking of CCL5 or CCR5 effectively inhibited the invasive capacity and PNI activity of SACC cells (P < .05).

CONCLUSIONS

Our results suggest a pivotal role of CCL5/CCR5 axis in tumor-nerve interactions during PNI of SACC. The CCL5/CCR5 pathway might prove to be an attractive new target for the treatment of SACC with PNI.