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Objective: Long non-coding RNAs (lncRNAs) are extensively involved in tumor development. In-depth researches on cancer-associated lncRNAs provide a theoretical basis for developing prognostic hallmarks and individualized therapeutic targets in breast cancer (BCa). This study aims to detect expression characteristics of LINC00174 in BCa and its biological role in regulating BCa cell phenotypes., Patients and Methods: LINC00174 levels in BCa and adjacent normal tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The influence of LINC00174 on pathological indicators of BCa was analyzed. In MCF-7 and MDA-MB-231 cells with LINC00174 knockdown, proliferative and migratory abilities were examined by cell counting kit-8 (CCK-8), colony formation and transwell assay, respectively. At last, molecular mechanisms of LINC00174 and its downstream gene miR-1827 in regulating BCa development were explored by Luciferase assay and rescue experiments., Results: LINC00174 was upregulated in BCa tissues than adjacent normal ones. High level of LINC00174 predicted advanced tumor staging, high metastasis rate and poor prognosis in BCa. Knockdown of LINC00174 attenuated proliferative and migratory abilities in BCa cells. MiR-1827 was the target gene binding LINC00174, showing a negative correlation between each other. Silence of miR-1827 abolished the regulatory effects of LINC00174 on proliferative and migratory abilities in BCa cells., Conclusions: LINC00174 is upregulated in BCa samples. It is closely linked to tumor staging, metastasis and prognosis in BCa. By negatively regulating miR-1827 level, LINC00174 aggravates the malignant development of BCa.

Objective: To study the effectiveness of natural killer cell-derived exosome (NK-Exos)-entrapped paclitaxel (PTX-NK-Exos) in enhancing its anti-tumor effect., Materials and Methods: The NK-Exos were isolated through ultra-high-speed centrifugation, and the PTX-NK-Exos system was constructed via electroporation. The morphology, particle size, Zeta potential and entrapment rate of PTX-NK-Exos were evaluated using transmission electron microscope (TEM), dynamic light scattering (DLS), Western blotting and high-performance liquid chromatography (HPLC), respectively. The uptake of Exos in human breast cancer MCF-7 cells was observed under a laser confocal microscope. Moreover, the effect of PTX-NK-Exos on MCF-7 cell viability was determined through methyl thiazolyl tetrazolium (MTT) assay, flow cytometry and 4',6-diamidino-2-phenylindole (DAPI) staining. The effects of PTX-NK-Exos on messenger ribonucleic acid (mRNA) and protein expressions of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax) and Caspase-3 in MCF-7 cells were detected using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting, respectively., Results: The NK-Exos were successfully isolated via ultra-high-speed centrifugation, and they had uniform particle size and high expression of markers for Exos. MCF-7 cells could take up Exos. The PTX-NK-Exos drug delivery system was successfully prepared using electroporation. In PTX group and NK-Exos group, the proliferation of MCF-7 cells declined, the nuclear apoptosis was evident and the apoptosis rate of MCF-7 cells rose compared with those in Control group. In PTX group and PTX-NK-Exos group, the migration of MCF-7 cells declined compared with that in Control group. According to the results of qRT-PCR and Western blotting, PTX-NK-Exos exerted an anti-tumor effect through inducing the up-regulation of Bax and Caspase-3 in the apoptotic signaling pathway in tumor cells., Conclusions: Exos isolated through ultra-high-speed centrifugation can be used to prepare the PTX-NK-Exos drug delivery system through electroporation. Drug-loaded Exos can effectively inhibit proliferation and induce apoptosis of tumor cells, thereby exerting an anti-tumor effect.

Objective: To elucidate the role of telomerase RNA elements (TERC) in alleviating osteoporosis (OP) by absorbing microRNA-217 (miRNAs-217) to regulate runt-related transcription factor 2 (RUNX2) level., Materials and Methods: The serum levels of TERC and miRNA-217 in OP patients and healthy controls were determined. During the osteogenic process, the relative levels of alkaline phosphatase (ALP), RUNX2, and Osterix were determined in hMSCs. The regulatory effects of TERC, miRNA-217, and RUNX2 on ALP and RUNX2 levels in hMSCs were examined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot. In addition, the changes in ALP activity and calcification ability in hMSCs influenced by them were assessed through ALP activity determination and alizarin red staining, respectively. The interaction of TERC/miRNA-217/RUNX2 regulatory loop and its role in influencing hMSCs osteogenesis were assessed by Dual-Luciferase Reporter Gene Assay and a series of rescue experiments, respectively., Results: The downregulated TERC and upregulated miRNA-217 were identified in the serum of the OP patients. Consistently, the downregulated TERC and upregulated miRNA-217 were discovered in in vitro osteogenic process of hMSCs. The silence of TERC, or RUNX2 downregulated ALP and RUNX2 levels, decreased ALP activity and attenuated the calcification ability in hMSCs. The overexpression of miRNA-217 gave similar results. The binding relationship in TERC/miRNA-217/RUNX2 regulatory loop was verified. At last, rescue experiments suggested that TERC accelerated hMSCs osteogenesis by absorbing miRNA-217 to upregulate RUNX2., Conclusions: The serum level of TERC is lowly expressed in OP patients. TERC influences hMSCs osteogenesis by absorbing miRNA-217 to upregulate RUNX2, thus alleviating the progression of OP.