Of note, Gupta et al didn’t detect the expression of CCL25 in lung cancer cells. performed to detect the expression of CCR9 in lung adenocarcinoma tissues. The correlations of CCR9 with distant metastasis and overall survival were investigated. Serial paraffin-embedded tissue blocks were used to detect ALDH1A1+CSCs expression. The correlations between CCR9 expression and ALDH1A1+CSCs were evaluated. We further studied the effect of CCR9/CCL25 around the migration and invasion of CSCs using transwell assays. Results: There were positive correlations between CCR9 expression and distant metastasis, as well as poor overall survival. Patients with high CCR9 expression were more likely to develop distant metastasis and exhibited poorer overall survival than patients with low CCR9 expression. In Luteolin addition, there was positive correlation between the expression of CCR9 and ALDH1A1 in the same tumor microenvironment. ALDHhigh CSCs exhibited enhanced expression of CCR9 than ALDHlow cells. Further transwell assays exhibited that the numbers of CSCs migrated or invaded in response to CCL25 were more than that without CCL25 stimulation. Additional application of anti-CCR9 antibody reversed the CCL25-induced migration and invasion of CSCs. Conclusions: In summary, our study exhibited that CCR9/CCL25 promoted the migration and invasion of CSCs, which might contribute to distant metastasis and poor overall survival. Our findings provided evidence that CCR9/CCL25 could be used as novel therapeutic targets for lung adenocarcinoma. value 0.05 was considered statistically significant. Results Increased CCR9 expression correlated with distant metastasis and poor outcomes of lung adenocarcinoma patients The expression of CCR9 and its ligand CCL25 in the tumor tissues of lung adenocarcinoma patients was investigated using immunohistochemistry. High expression of CCR9 was detected in 48 cases, while 28 cases displayed low CCR9 expression. The representative photomicrographs are shown in Figure ?Figure1A1A and B. However, CCL25 expression was barely detected in lung adenocarcinoma tissues (supplementary Physique 1). We further analyzed the relationship between CCR9 and distant metastasis. As shown in Table ?Table1,1, there was significant correlation between CCR9 expression and distant metastasis (= 0.026). The high expression rates of CCR9 in patients staged as M0 and M1 were 53.8% and 83.3%, respectively, while the low expression rates were 46.3% and 16.7%, respectively. Open in a separate window Physique Luteolin 1 The expression and prognostic value of CCR9 and ALDH1A1 in lung adenocarcinoma patients. Representative microphotographs of CCR9 expression: (A) High CCR9 expression; (B) Low CCR9 expression. (C) Kaplan-Meier curve of overall survival predicted by CCR9 expression. Patients with low CCR9 expression demonstrated OS than patients with high CCR9 expression. Representative microphotographs of high ALDH1A1 expression (D) and low ALDH1A1 expression (E). (F) Increased ALDH1A1 expression was positively correlated with poor overall survival. Original magnification: 400. Table 1 The relationship between CCR9 expression and distant metastasis in lung adenocarcinoma P= 0.007). Patients with high CCR9 expression had poorer OS than those Rabbit polyclonal to PITPNM1 with low CCR9 expression. Increased expression of ALDH1A1+ cancer stem cells (CSCs) was correlated with distant metastasis and poor overall survival Furthermore, the expression of ALDH1A1+ CSCs in the same tumor microenvironment was detected using serial paraffin-embedded sections. ALDH1A1 was highly expressed in 45 cases and lowly expressed in 31 cases. Figure ?Physique1D1D and E showed representative images of ALDH1A1+CSCs. Kaplan- Meier survival analysis showed that ALDH1A1 expression could predict the overall survival (OS). Lung adenocarcinoma patients with high ALDH1A1 expression had poorer OS than those with low ALDH1A1 expression (= 0.003, Figure ?Physique1F).1F). There was positive correlation between the expression of ALDH1A1+CSCs and distant metastasis (Table ?(Table2,2, = 0.016). Patients in the ALDH1A1 high expression group were more likely to develop distant metastasis. Table 2 The relationship between ALDH1A1+CSCs expression and distant metastasis in lung adenocarcinoma 0.001, Figure ?Physique2C).2C). As shown in Figure ?Physique2C,2C, the immunostaining scores of CCR9 in ALDH1A1 high expression group was generally higher than that of in ALDH1A1 low expression group. Open in a separate windows Physique 2 CCR9 expression was positively correlated with ALDH1A1+CSCS expression in lung adenocarcinoma. Representative microphotographs of CCR9 and ALDH1A1 expression in the lung adenocarcinoma patients: Luteolin (A) The same patient with both high CCR9 expression and high ALDH1A1 expression; (B) The same patient with both low CCR9 expression and low ALDH1A1 expression. (C) There was a positive correlation between the expression of CCR9 and ALDH1A1+ CSCs. Original magnification: 400. CCR9 was highly expressed Luteolin on ALDHhigh cancer stem cells (CSCs) To further clarify the correlation between CCR9 and CSCs, we detected the expression of CCR9 on CSCs. Both ALDHhigh CSCs and ALDHlow non-CSCs were isolated from lung adenocarcinoma cell line A549 using ALDEFLUOR assay. Expression level of CCR9 on ALDHhigh CSCs was much higher than that on ALDHlow cells. Representative graphs of flow cytometry were demonstrated in Physique ?Figure3A3A and B. The result was further confirmed by real time quantitative PCR. ALDHhigh A549 cells expressed more CCR9 than ALDHlow cells (Physique ?(Physique3C,3C, 0.001). Open in a separate window Figure.
Of note, Gupta et al didn’t detect the expression of CCL25 in lung cancer cells