Effect of simvastatin and microRNA-21 inhibitor on metastasis and progression of human salivary adenoid cystic carcinoma.

Salivary adenoid cystic carcinoma (SACC) is a common malignancy of the salivary glands. Epithelial-mesenchymal transition (EMT) and P53 signaling pathway are associated with SACC metastasis and progression. Although simvastatin (SIM) is effective against the growth of many cancer types, its side effects limit its use. microRNA-21 (miR-21) is highly expressed in a variety of tumors and has a role in promoting tumor development. Therefore, the aim of the present study was to evaluate the effect of SIM in combination with miR-21 inhibitor (miR-21i) against lung metastatic SACC cells (SACC-LM). Our results showed that miR-21i was effective in reducing the resistance of SACC-LM to SIM, resulting in SACC-LM acquisition of epithelial traits, cell migration and invasion reduction, growth inhibition and induction of apoptosis. The expression of proteins associated to metastasis and tumor progression were regulated by the combined use of SIM and miR-21i. Thus, our findings demonstrated that such combination was effective in inhibiting SACC-LM progression, suggesting that multi-target therapy against SACC might represent a potentially successful approach in clinical treatment.

Wang C ，Li T ，Yan F ，Cai W ，Zheng J ，Jiang X ，Sun J ... -  《-》

MicroRNA Profiling and Target Genes Related to Metastasis of Salivary Adenoid Cystic Carcinoma.

Perineural invasion and distant metastasis lead to a poor prognosis of adenoid cystic carcinoma and there is no effective therapy available. MicroRNAs (miRNAs) are small non-coding RNAs that regulate target gene expression, which can be biomarkers or therapeutic targets for certain cancer types. We aimed to identify miRNAs and their target genes possibly involved in metastasis of salivary gland adenoid cystic carcinoma (SACC). Using Nanostring nCounter analysis, we examined miRNA expression in two SACC cell lines: SACC-83 and SACC-LM, with low and high lung metastasis rates, respectively. We then verified the differentially expressed miRNAs with real-time polymerase chain reaction in the cell lines and in tumor samples from patients with SACC. miRNA target-gene expression was also analyzed. SACC-83 showed higher gene expression of miR-130a, miR-342, and miR-205; SACC-LM showed higher gene expression of miR-99a and miR-155. In human tissue, miR-205 was highly expressed in the primary SACC, while miR-155 and miR-342 were highly expressed in recurrent SACC. Six predicted target genes of miRNA-155 and miR-99a linked to tumorigenesis were further analyzed and RNA expression of ubiquitin-like modifier activating enzyme 2 (UBA2) was higher in SACC than normal salivary gland tissue, and higher in primary compared to recurrent SACC (p<0.05). RNA expression of retinoic acid receptors (RARS) was higher in tissue from primary than recurrent SACC and normal salivary gland (p<0.05), but that in recurrent SACC was not significantly higher than normal salivary gland tissue. RNA expression of minichromosome maintenance 8 homologous recombination repair factor (MCM8) and 24-dehydrocholesterol reductase (DHCR24) was higher in primary SACC than normal salivary gland tissue (p<0.05). miR-99a, miR-155, miR-130a, miR-342, and miR-205 may play a role in metastasis of SACC. MiR-155 may be involved in SACC metastasis through UBA2 pathways, and UBA2 may function as a biomarker/mediator of SACC metastasis.

Feng X ，Matsuo K ，Zhang T ，Hu Y ，Mays AC ，Browne JD ，Zhou X ，Sullivan CA ... -  《-》

BDNF mediated TrkB activation contributes to the EMT progression and the poor prognosis in human salivary adenoid cystic carcinoma.

The aim of the present study was to investigate whether the expression of Brain-Derived Neurotrophic Factor (BDNF) and its receptor Tropomyosin-related kinase B (TrkB) is correlated with the clinical progression of salivary adenoid cystic carcinoma (SACC) and whether the BDNF/TrkB axis is associated with the induction of epithelial-mesenchymal transition (EMT) in SACC cells. The expression of BDNF, TrkB, and E-cadherin (an EMT biomarker) in 76 primary SACC specimens and 20 normal salivary gland tissues was analyzed by immunohistochemistry. Additionally, the expression of BDNF, TrkB, and E-cadherin in SACC cell lines (SACC-83 and SACC-LM) was analyzed by RT-PCR and Western blotting. The biological role of the BDNF/TrkB axis in the EMT progression of SACC was evaluated after treatment with increased levels of BDNF and by inhibiting TrkB activity in SACC-83 cell line. The progression of SACC cells through EMT was assessed by RT-PCR, Western blotting, photography, migration and invasion assays. Elevated expression of TrkB (92.1%) and BDNF (89.5%), and downregulated expression of E-cadherin (47.4%) was found in SACC specimens, which was significantly correlated with the invasion and metastasis in SACC (P<0.05). The high expression of TrkB and the low expression of E-cadherin was significantly correlated with the poor prognosis of SACC patients (P<0.05). The expression of TrkB was inversely correlated with the expression of E-cadherin in both SACC cases and cell lines (P<0.05). Increasing BDNF levels after treatment with exogenous recombinant human BDNF (rhBDNF) at 100 ng/ml significantly promoted the activation of TrKB and the progression of EMT in SACC cells. While obstruction of TrkB by its inhibitor, k252a (100 nM), significantly inhibited the EMT progression of SACC cells. These results suggest that BDNF-mediated TrkB activation contributes to the EMT progression and the poor prognosis in SACC. The present study demonstrated that the BDNF/TrkB axis promotes the migration and invasion of SACC cells via EMT in vitro. Targeting the inactivation of the BDNF/TrkB axis may be a potential strategy for the treatment of SACC.

Jia S ，Wang W ，Hu Z ，Shan C ，Wang L ，Wu B ，Yang Z ，Yang X ，Lei D ... -  《-》

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.

Tang Y ，Zhu Q ，Yang L ，Meng Y ，Zhang G ，Zhou T ，Wang C ，Song X ，Su YX ，Ye J ... -  《-》

Claudin-7 Inhibits Proliferation and Metastasis in Salivary Adenoid Cystic Carcinoma Through Wnt/β-Catenin Signaling.

Ji H ，Ding X ，Zhang W ，Zheng Y ，Du H ，Zheng Y ，Song H ，Li M ，Jiang Y ，Xie J ，Wu M ，Jiao P ，Wang Z ，Wu H ，Zhong Y ... -  《-》