C-C chemokine receptor type 7 (CCR7) has been implicated in lymph node metastasis of various cancers. Previous studies have revealed that epithelial-mesenchymal transition (EMT) is involved in the chemotactic process mediated by CCR7 and its ligands in various types of carcinoma. However, the underlying mechanism of this process remains to be fully elucidated. The present study investigated whether chemokine (C-C motif) ligand 21 (CCL21)/CCR7 may activate EMT of lung cancer cells and their associated signaling pathways. A549 and H520 lung cancer cell lines were examined in vitro in the present study. The results indicated that A549 and H520 expressed CCR7, but reduced levels of CCL21. Following stimulation of lung cancer cell lines with CCL21, the expression of the epithelial marker E-cadherin was downregulated, and the mesenchymal markers Vimentin/Slug and extracellular signal-regulated kinase (ERK) were upregulated. In addition, the ERK inhibitor PD98059 may inhibit EMT caused by CCL21, and decreased cell migration and invasion initiated by CCL21. Furthermore, lung adenocarcinoma tissues from 50 patients who underwent lung cancer operations were investigated by immunohistochemistry. The findings revealed that CCR7, Slug and Vimentin were highly expressed in lung carcinoma tissues, and were significantly associated with lymph node metastasis and clinical pathological stages, respectively. CCR7 expression was correlated positively with expression levels of Slug and Vimentin. CCL21 was expressed positively in the endothelium of lymphatic vessels adjacent to cancer cells, and weakly in lung cancer cells. Collectively, these results demonstrated that CCL21/CCR7 may activate EMT in lung cancer cells via the ERK1/2 signaling pathway. The current study provides evidence that a close interaction exists between CCL21/CCR7chemotaxis and EMT procedures in lung cancer metastasis, providing a basis for the development of therapeutic targets.

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ObjectiveTo explore the roles of advanced paternal age (APA) and abnormal paternal weight on embryo quality and pregnancy outcomes for unexplained recurrent pregnancy loss (uRPL) couples who underwent preimplantation genetic testing for aneuploidies (PGT-A).MethodsThis study included 779 uRPL couples who underwent their first PGT-A cycles between 2014 and 2018. Male patients’ aging and nutritional status were quantified by paternal age and body mass index (BMI). Routine semen parameters and sperm DNA fragmentation index (DFI) were used to reflect the seminal quality. Blastocyst formation rate and aneuploidy rate were used to reflect the embryo quality. Cycle cancellation rate, implantation rate, pregnancy loss rate, and live birth rate were measured to evaluate the treatment efficiency from IVF. To remove the interference of maternal age, only the women younger than 38 years old were included. After univariate screening, interaction tests were performed in a generalized linear model (GLM) to further examine the effects of paternal age and BMI on each outcome indicator.ResultsIn the total population (779 cycles), there were no statistical differences in aneuploidy rate, cycle cancellation rate, implantation rate, pregnancy loss rate, and live birth rate, whether stratified by paternal age or paternal BMI. Similar results occurred in the younger men (<40 y.o., 633 cycles). Conversely, among the men with advanced age (≥40 y.o., 146 cycles), there were statistical differences between the three BMI groups in four semen parameters (total sperm number, total motility, progressive motility, and total motile sperm count), implantation rate, and live birth rate. After interaction testing, the results of GLM suggested that the interaction effect between APA and paternal obesity was associated with the low implantation rate of uRPL couples.ConclusionsFor the uRPL couples seeking for PGT-A treatment, if the male patients have both advanced age and obesity, their spouses are at higher risks for embryo implantation failure.