Objective: To investigate the effects and the mechanism of Calcyclin-binding protein (CacyBP) on the proliferation and invasion of non-small cell lung cancer (NSCLC) cells. Methods: Six lung cancer tissues and paired normal lung tissues were collected from NSCLC patients who underwent surgical treatment in Jinan Central Hospital during 2016. The expression of CacyBP in these tissues was examined by western blot. The protein and mRNA expression of CacyBP in human bronchial epithelial cells (16HBE), NSCLC cell lines including A549, H1299, H460 and H1975 were examined by western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. RNAi and shRNA against negative control (NC) or CacyBP were transfected into A549 cell which were denoted as siNC group, siCacyBP-1 group, sicacyBP-2 group, shNC group and shCacyBP group, respectively. Control and Flag-CacyBP plasmids were transfected into A549 cells which were denoted as NC group and Flag-CacyBP group, respectively. Cell counting kit-8 (CCK-8), plate clone formation assay and flow cytometry assay were used to assess cell proliferation ability and cycle of A549. Wound healing assay and transwell assay were used to assess abilities of A549 cells migration and invasion. The protein expressions of epithelial-mesenchymal transition (EMT) markers including E-cadherin, N-cadherin, Snail1, Vimentin, and phosphorylation of protein kinase B (p-Akt) were examined in CacyBP depleted or overexpressed A549 cells. Results: The CacyBP protein level in NSCLC tissues was 0.41±0.23, significantly higher than 0.11±0.04 in normal lung tissues (P<0.05). The CacyBP protein expression levels in different NSCLC cell lines including A549, H1299, H460 and H1975 were 0.35±0.01, 0.38±0.01, 0.32±0.01 and 0.41±0.01, respectively, which were significantly higher than 0.03±0.01 in 16HBE cells (P<0.05). The result of RT-PCR was consistent with that of western blot. Compared with siNC group (absorbance was 1.54±0.03), siCacyBP-1 group and siCacyBP-2 group showed decreased cell proliferation (absorbances were 1.38±0.04 and 1.34±0.03, P<0.05). The number of cell colony in shNC group was 41.33±3.21, significantly higher than 22.00±3.61 in shCacyBP group (P<0.05). The proportion of G(1) phase in shCacyBP group was (61.35±5.45)%, higher than (49.61±1.54) % in shNC group (P<0.05). The proportion of S phase was (25.41±3.21)%, which was lower than (38.68±0.46)% of shNC group (P<0.05). The cell migration rate of shCacyBP group was (12.67±0.71)%, which was significantly lower than (35.50±2.07)% of shNC group (P<0.05). The numbers of cell migration and invasion in shNC group were 406.33±7.37 and 92.33±8.50, respectively, which were significantly higher than 224.67±10.01 and 66.00±7.94 in shCacyBP group (P<0.05). Compared with siNC group, the expression of epithelial marker E-cadherin was up-regulated, while the expressions of mesenchymal markers including N-cadherin, Vimentin, Snail1 and p-Akt were down-regulated in CacyBP depleted A549 cells. Compared with NC group, overexpression of CacyBP inhibited E-cadherin expression while promoted the expressions of N-cadherin, Snail1, Vimentin and p-Akt, which could be restored by LY294002. Conclusion: CacyBP may promote the proliferation and invasion of NSCLC cells by regulating Akt signal pathway.
目的： 探讨钙周期素结合蛋白(CacyBP)对非小细胞肺癌细胞增殖和侵袭能力的影响及其分子机制。 方法： 选取2016年于济南市中心医院行手术治疗的非小细胞肺癌患的肺癌组织和正常癌旁组织标本各6例，采用Western blot法检测肺癌和正常癌旁组织中CacyBP蛋白的表达水平，Western blot和逆转录聚合酶链反应(RT-PCR)检测正常支气管上皮细胞16HBE和不同非小细胞肺癌细胞系(A549、H1299、H460和H1975)中CacyBP蛋白和mRNA的表达水平。将siRNA、siCacyBP-1、siCacyBP-2、慢病毒包装质粒shNC和shCacyBP转染至A549细胞(分别记为siNC组、siCacyBP-1组、siCacyBP-2组、shNC组和shCacyBP组)，将对照质粒和Flag-CacyBP质粒转染至A549细胞(分别记为NC组和Flag-CacyBP组)。采用细胞计数试剂盒8法、平板克隆实验以及流式细胞术检测细胞增殖能力以及细胞周期情况，细胞划痕和Transwell实验检测细胞迁移和侵袭能力，Western blot法检测敲低或过表达CacyBP A549细胞中E-cadherin、N-cadherin、Snail1、Vimentin和磷酸化蛋白激酶B(p-Akt)的表达。 结果： CacyBP蛋白在非小细胞肺癌组织中的表达水平为0.41±0.23，高于正常癌旁组织(0.11±0.04，P<0.05)。不同非小细胞肺癌细胞系(A549、H1299、H460和H1975)CacyBP蛋白的表达水平分别为0.35±0.01、0.38±0.01、0.32±0.01和0.41±0.01，均高于16HBE细胞(0.03±0.01，均P<0.05)；RT-PCR结果与Western blot结果一致。与siNC组[吸光度(A)值为1.54±0.03]比较，siCacyBP-1组和siCacyBP-2组细胞增殖能力降低(分别为1.38±0.04和1.34±0.03，均P<0.05)。shNC组细胞克隆形成数为(41.33±3.21)个，高于shCacyBP组[(22.00±3.61)个，P<0.05]。shCacyBP组细胞G(1)期占比为(61.35±5.45)%，高于shNC组[(49.61±1.54)%，P<0.05]；S期占比为(25.41±3.21)%，低于shNC组[(38.68±0.46)%，P<0.05]。shCacyBP组细胞迁移率为(12.67±0.71)%，低于shNC组[(35.50±2.07)%，P<0.05]。shNC组细胞迁移和侵袭的数量分别为(406.33±7.37)个和(92.33±8.50)个，高于shCacyBP组[分别为(224.67±10.01)个和(66.00±7.94)个，均P<0.05]。与siNC组相比，敲低CacyBP的表达，E-cadherin的表达水平升高，N-cadherin、Vimentin、Snail1和p-Akt的表达水平降低(均P<0.05)。与NC组相比，Flag-CacyBP组E-cadherin的表达水平降低，N-cadherin、Vimentin、Snail1和p-Akt的表达水平升高(均P<0.05)，PI3K/Akt通路抑制剂LY294002可逆转上述结果。 结论： CacyBP通过调控Akt通路的活性促进非小细胞肺癌细胞的增殖和侵袭。.
Keywords: CacyBP; Invasion; Neoplasms, non-small cell lung; Proliferation.