Silencing of AJAP1 expression by promoter methylation activates the Wnt/ß-catenin signaling pathway to promote tumor proliferation and metastasis in salivary adenoid cystic carcinoma.

Background: Salivary adenoid cystic carcinoma (SACC) is a unique malignant tumor of the salivary gland with poor prognosis, which is not effective with chemotherapy and targeted drugs. Therefore, it is important to explore the molecular mechanism underlying SACC invasion and metastasis to develop novel therapeutic strategies and targets in clinical research. Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) were performed to detect the expression of Adherens Junctions Associated Protein 1 (AJAP1). Methylation-specific PCR was used to evaluate the methylation of the AJAP1 promoter. AJAP1 was overexpressed or knocked down by lentivirus-mediated transfection. Kaplan-Meier analysis was conducted to create a survival curve and the log-rank test was used to analyze the overall survival (OS). The prognostic correlation was assessed using univariate and multivariate Cox regression analyses. Co-immunoprecipitation (Co-IP) was utilized to pull down the possible binding protein of AJAP1 and laser scanning confocal microscopy was applied to detect the subcellular localization of AJAP1, E-cadherin, and ß-catenin. Cell viability, colony formation, wound healing, and Transwell invasion assays were performed to evaluate the function of AJAP1 in vitro. A subcutaneous xenograft assay in nude mice was performed to verify the function of AJAP1 in vivo. Results: AJAP1 was downregulated in SACC tumors and was closely related to SACC lymph node/distant metastasis, which was an independent risk factor for SACC prognosis. Methylation-specific PCR confirmed that high methylation of the AJAP1 promoter was the main cause of its silencing. Overexpression or knockdown of AJAP1 in SACC cells could significantly inhibit or promote the proliferation, invasion, and metastasis of SACC cells, respectively, in both the in vitro and in vivo experiments. Mechanically, we found that AJAP1 binds to E-cadherin and ß-catenin to form a complex in cytomembrane, reducing the nuclear translocation of ß-catenin and blocking the Wingless/Integrated/ß-catenin (Wnt/ß-catenin) signaling pathway to play a suppressive role in cancer. Conclusions: In conclusion, these results suggest that the downregulation of AJAP1 protein expression may play a certain role in progression and metastasis of SACC. Our study indicates that AJAP1 may be a potential prognostic molecular marker and therapeutic target for SACC.

Identification of prognostic biomarkers for papillary thyroid carcinoma by a weighted gene co-expression network analysis.

AIM: Whole transcriptome analysis was conducted to identify differentially expressed RNAs and regulatory networks associated with papillary thyroid carcinoma (PTC). METHODS: A weighted gene co-expression network analysis based on high-throughput sequencing data for six pairs of PTC and adjacent tissue samples was conducted to understand the biological functions and regulatory networks involving long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs). RESULTS: We detected 131, 338, 31, and 556 differentially expressed circRNAs, lncRNAs, miRNAs, and mRNAs, respectively. We identified modules that were significantly positively and negatively related to cancer and lymph node metastasis. Gray and turquoise modules were positively correlated with cancer phenotypes (p < 0.05), whereas yellow, brown, and blue modules were negatively correlated with cancer (p < 0.05). Gray module was positively correlated with lateral lymph node metastasis (p = 0.02). Kaplan-Meier analyses revealed that the levels of transmembrane protein 63C (TMEM63C), lysyl oxidase-like 1 (LOXL1), collagen type V alpha 1 chain (COL5A1), ADAM metalloproteinase with thrombospondin type I motif 2 (ADAMTS2), and LysM-domain containing 3 (LYSMD3) were significantly associated with overall survival (p < 0.05). Significant increase in the expression of COL5A1 and LOXL1 in tumor tissues was validated by quantitative real-time polymerase chain reaction (p < 0.05). COL5A1 and LOXL1 promoted PTC cell growth and invasion in vitro. CONCLUSIONS: We identified COL5A1 and LOXL1 as potential prognostic biomarkers, providing new insights into the occurrence and progression of PTC.

Light-Responsive Micelles Loaded With Doxorubicin for Osteosarcoma Suppression.

The enhancement of tumor targeting and cellular uptake of drugs are significant factors in maximizing anticancer therapy and minimizing the side effects of chemotherapeutic drugs. A key challenge remains to explore stimulus-responsive polymeric nanoparticles to achieve efficient drug delivery. In this study, doxorubicin conjugated polymer (Poly-Dox) with light-responsiveness was synthesized, which can self-assemble to form polymeric micelles (Poly-Dox-M) in water. As an inert structure, the polyethylene glycol (PEG) can shield the adsorption of protein and avoid becoming a protein crown in the blood circulation, improving the tumor targeting of drugs and reducing the cardiotoxicity of doxorubicin (Dox). Besides, after ultraviolet irradiation, the amide bond connecting Dox with PEG can be broken, which induced the responsive detachment of PEG and enhanced cellular uptake of Dox. Notably, the results of immunohistochemistry in vivo showed that Poly-Dox-M had no significant damage to normal organs. Meanwhile, they showed efficient tumor-suppressive effects. This nano-delivery system with the light-responsive feature might hold great promises for the targeted therapy for osteosarcoma.

Advances in targeted therapy for anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) is a highly malignant and aggressive thyroid malignancy with rapid onset and poor prognosis. There is no effective treatment for ATC yet. Molecular targeted therapy provides a new idea for ATC treatment. Tyrosine kinase inhibitor lenvatinib has potential in treating ATC patients with favorable efficacy in clinical trials. The effectiveness of the v-raf murine sarcoma viral oncogene homologue B1 () gene inhibitor dabrafenib in combination with trametinib for the treatment of positive ATC patients has been demonstrated in clinical trials. The has proposed dabrafenib in combination with trametinib as the preferred modality for the treatment of patients with positive ATC. The immune checkpoint inhibitor pembrolizumab can be applied to treat thyroid cancer with high tumor mutational load and may be considered as the preferred modality for the treatment of ATC patients with high programmed death ligand-1 expression. The mammalian target of rapamycin pathway inhibitors, peroxisome proliferators-activated receptor γ agonists, endothelial growth factor receptors-targeting monoclonal antibody cetuximab and novel vascular blocker fosbretabulin are still in the clinical research stage, which are expected to provide new directions for the development of novel targeted drugs. This article reviews the current research progress on targeted drugs for the treatment of ATC.