contributed to the editing of the manuscript. Conflicts of Interest The authors declare no competing financial interest. Acknowledgments This work was supported by the National Natural Science Foundation of China (nos. GC. hybridization (ISH) by analyzing a large cohort of 153 archived paraffin-embedded GC specimens and normal tissues. miR-577 was found to be highly expressed in GC, and its expression increased relative to the progression of the tumor stage (Figure?1E). It showed a significant correlation between miR-577 expression and clinical variables, including TNM stage (p? 0.05), tumor invasion (p? 0.05), lymph node metastasis (p? 0.05), distant metastasis (p? 0.01), recurrence (p? 0.05), Lercanidipine and OS (p? 0.05), while age, gender, and tumor differentiation were not correlated with miR-577 expression (Figure?1F; Table S1). Kaplan-Meier survival analysis revealed that GC patients with high miR-577 expression had worse disease-free survival (DFS) in stage ICIII patients and worse overall survival in stage-IV patients (p? 0.001 and p? 0.001, respectively; Figure?1G). Univariate survival analysis showed that high miR-577 expression was associated with the shorter OS (p? 0.001, hazard ratio [HR]?= 2.473; Table 1). Furthermore, multivariate survival analysis indicated that the expression of miR-577, T classification, and age were independent predictors for prognosis in GC patients (Table 1). Open in a separate window Figure?1 miR-577 Is Upregulated in GC and Associated with Poor Prognosis (A) qRT-PCR analysis of miR-577 expression in 36 pairs of GC specimens and normal tissues. miR-577 was normalized to endogenous U6 RNA and expressed relative to their respective match normal tissues. (B) The expression of miR-577 in 36 pairs of GC specimens and normal tissues. **p? 0.01. (C) The miR-577 expression in TNM stage I and stage II GC tissues and Lercanidipine stage III and stage IV GC tissues. *p? 0.05. (D) The miR-577 expression in GC tissues with or without metastasis. ***p? 0.001. (E) hybridization (ISH) analysis of miR-577 expression in 153 human normal gastric tissues and GC specimens from TNM stage ICIV patients. (F) Frequency of low and high miR-577 expressions categorized by TNM stage, tumor invasion, lymph node metastasis, distant metastasis, recurrence, and death (p?= 0.022, p?= 0.019, p?= 0.027, p?= 0.002, p?= 0.029, and p?= 0.030, respectively). Patients were separated into high- and/or low-expression groups by the expression score of the miR-577. *p? 0.05; **p? 0.01. (G) Retrospective analysis of Kaplan-Meier plots for miR-577 expression in association with disease-free survival and overall survival. (H) qRT-PCR analysis of miR-577 expression in GC cell lines and an immortalized human gastric cell line. Data represent mean? SD. Table 1 Univariate and Multivariate Analyses of Individual Parameters for Correlations with Overall Survival Rate: Cox Proportional Hazards Model and (Figures CENPF S2ECS2G). For analysis, we constructed the subcutaneous-tumor mouse model and found that miR-577 overexpression or suppression showed no impacts on tumor weights, volumes, tumor signals, or the Ki-67 index (Figures S2HCS2K). We then assessed the metastatic potential of miR-577. Results from Transwell assays showed that the overexpression of miR-577 significantly enhanced cell migration and invasiveness, while this effect was abolished when treated with the miR-577 antagonist AntagomiR (p? ?0.01; Figures 2A and 2B). Subsequently, to observe the effect of miR-577 on lung colonization, malignancy cells were injected into the tail vein of nude mice. Higher metastasis signals and shorter survival time were found in the miR-577 overexpressed group compared with the control group, Lercanidipine while miR-577 suppression in MKN45 cells led to the opposite effects (Numbers 2CC2E). We also found that more and larger tumor nodules were created in the LV-miR-577 group compared with the lentivirus of bad control (LV-NC) group. In contrast, miR-577 inhibition reduced the number of lung metastases compared with that in the control group (Number?2F). Open in a separate window Number?2 miR-577 Promotes GC Metastasis and effect of SDPR on GC cell metastasis, we established that MGC803 stably suppressed SDPR cells.