A novel long non-coding RNA MIR4500HG003 promotes tumor metastasis through miR-483-3p-MMP9 axis in triple-negative breast cancer.

Breast cancer (BC) is the most common cancer and the leading cause of cancer-related deaths in women worldwide. The 5-year survival rate is over 90% in BC patients, but once BC cells metastasis into distal organs, it is dramatically decreasing to less than 30%. Especially, triple-negative breast cancer (TNBC) patients usually lead to poor prognosis and survival because of metastasis. Understanding the underline mechanisms of TNBC metastasis is a critical issue. Non-coding RNAs, including of lncRNAs and microRNAs, are non-protein-coding transcripts and have been reported as important regulators in TNBC metastasis. However, the underline mechanisms for non-coding RNAs regulating TNBC metastasis remain largely unclear. Here, we found that lncRNA MIR4500HG003 was highly expressed in highly metastatic MDA-MB-231 TNBC cells and overexpression of MIR4500HG003 enhanced metastasis ability in vitro and in vivo and promoted MMP9 expression. Furthermore, we found MIR4500HG003 physically interacted with miR-483-3p and reporter assay showed miR-483-3p attenuated MMP9 expression. Importantly, endogenous high expressions of MIR4500HG003 were correlated with tumor recurrence in TNBC patients with tumor metastasis. Taken together, our findings suggested that MIR4500HG003 promotes metastasis of TNBC through miR-483-3p-MMP9 signaling axis and may be used as potential prognostic marker for TNBC patients.

ICAM2 initiates trans-blood-CSF barrier migration and stemness properties in leptomeningeal metastasis of triple-negative breast cancer.

Leptomeningeal metastasis (LM) occurs when tumor cells spread to the leptomeningeal space surrounding the brain and the spinal cord, thereby causing poor clinical outcomes. The triple-negative breast cancer (TNBC) has been associated with symptoms of LM and mechanism remained unclear. Through proteomic analysis, we identified high expression of ICAM2 in leptomeningeal metastatic TNBC cells, which promoted the colonization of the spinal cord and resulted in poor survival in vivo. Two-way demonstration indicated that high levels of ICAM2 promoted blood-cerebrospinal fluid barrier (BCB) adhesion, trans-BCB migration, and stemness abilities and determined the specificity of LM in vivo. Furthermore, pull-down and antibody neutralizing assay revealed that ICAM2 determined the specificity of LM through interactions with ICAM1 in the choroid plexus epithelial cells. Therefore, neutralizing ICAM2 can attenuate the progression of LM and prolong survival in vivo. The results suggested that targeting ICAM2 is a potential therapeutic strategy for LM in TNBC.

Concurrent Chemoradiotherapy-Driven Cell Plasticity by miR-200 Family Implicates the Therapeutic Response of Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a common and fatal malignancy with an increasing incidence worldwide. Over the past decade, concurrent chemoradiotherapy (CCRT) with or without surgery is an emerging therapeutic approach for locally advanced ESCC. Unfortunately, many patients exhibit poor response or develop acquired resistance to CCRT. Once resistance occurs, the overall survival rate drops down rapidly and without proper further treatment options, poses a critical clinical challenge for ESCC therapy. Here, we utilized lab-created CCRT-resistant cells as a preclinical study model to investigate the association of chemoradioresistantresistance with miRNA-mediated cell plasticity alteration, and to determine whether reversing EMT status can re-sensitize refractory cancer cells to CCRT response. During the CCRT treatment course, refractory cancer cells adopted the conversion of epithelial to mesenchymal phenotype; additionally, miR-200 family members were found significantly down-regulated in CCRT resistance cells by miRNA microarray screening. Down-regulated miR-200 family in CCRT resistance cells suppressed E-cadherin expression through snail and slug, and accompany with an increase in N-cadherin. Rescuing expressions of miR-200 family members in CCRT resistance cells, particularly in miR-200b and miR-200c, could convert cells to epithelial phenotype by increasing E-cadherin expression and sensitize cells to CCRT treatment. Conversely, the suppression of miR-200b and miR-200c in ESCC cells attenuated E-cadherin, and that converted cells to mesenchymal type by elevating N-cadherin expression, and impaired cell sensitivity to CCRT treatment. Moreover, the results of ESCC specimens staining established the clinical relevance that higher N-cadherin expression levels associate with the poor CCRT response outcome in ESCC patients. Conclusively, miR-200b and miR-200c can modulate the conversion of epithelial-mesenchymal phenotype in ESCC, and thereby altering the response of cells to CCRT treatment. Targeting epithelial-mesenchymal conversion in acquired CCRT resistance may be a potential therapeutic option for ESCC patients.

MiR-211 determines brain metastasis specificity through SOX11/NGN2 axis in triple-negative breast cancer.

Brian metastasis, which is diagnosed in 30% of triple-negative breast cancer (TNBC) patients with metastasis, causes poor survival outcomes. Growing evidence has characterized miRNAs involving in breast cancer brain metastasis; however, currently, there is a lack of prognostic plasma-based indicator for brain metastasis. In this study, high level of miR-211 can act as brain metastatic prognostic marker in vivo. High miR-211 drives early and specific brain colonization through enhancing trans-blood-brain barrier (BBB) migration, BBB adherence, and stemness properties of tumor cells and causes poor survival in vivo. SOX11 and NGN2 are the downstream targets of miR-211 and negatively regulate miR-211-mediated TNBC brain metastasis in vitro and in vivo. Most importantly, high miR-211 is correlated with poor survival and brain metastasis in TNBC patients. Our findings suggest that miR-211 may be used as an indicator for TNBC brain metastasis.