Department of Pediatric Surgery, Henan Provincial People's Hospital, No.7, Wei Wu Road, Zhengzhou, 450003, Henan, People's Republic of China.
Department of Clinical Laboratory, Third People's Hospital of Henan Province, Zhengzhou, Henan, People's Republic of China.
Mol Cell Biochem. 2020 Mar;466(1-2):55-63. doi: 10.1007/s11010-020-03687-w. Epub 2020 Feb 12.
Rap2B, belonging to the Ras superfamily of small guanosine triphosphate-binding proteins, is upregulated and contributes to the progression of several tumors by acting as an oncogene, including hepatocellular carcinoma (HCC). However, the mechanism underlying the functional roles of Rap2B in HCC remains unclear. In this study, the evaluation of Rap2B expression in HCC cells and tissues was achieved by qRT-PCR and western blot assays. The effects of Rap2B on the malignant biological behaviors in HCC were explored by means of MTT assay, flow cytometry analysis, and Transwell invasion assay, respectively. Protein levels of Ki67, matrix metalloproteinase (MMP)-2, MMP-9, and cleaved caspase-3, together with the alternations of the ERK1/2 and PTEN/PI3K/Akt pathways were qualified by western blot assay. Further verification of the Rap2B function on HCC tumorigenesis was attained by performing in vivo assays. We found that Rap2B levels were upregulated in HCC tissues and cells. Rap2B silencing led to a reduction of cell-proliferative and invasive abilities, and an increase of apoptosis in HCC cells. In addition, xenograft tumor assay demonstrated that Rap2B silencing repressed HCC xenograft tumor growth in vivo. In addition, we found that Rap2B knockdown significantly inhibited the ERK1/2 and PTEN/PI3K/Akt cascades in HCC cells and xenograft tumor tissues. Together, Rap2B knockdown inhibited HCC-malignant progression, which was involved in inhibiting the ERK1/2 and PTEN/PI3K/Akt pathways. Our findings contribute to understanding of the molecular mechanism of Rap2B in HCC progression.
Rap2B 属于 Ras 家族的小 GTP 结合蛋白，作为癌基因上调并促进多种肿瘤的进展，包括肝细胞癌 (HCC)。然而，Rap2B 在 HCC 中的功能作用的机制尚不清楚。在这项研究中，通过 qRT-PCR 和 Western blot 分析评估了 Rap2B 在 HCC 细胞和组织中的表达。通过 MTT 测定、流式细胞术分析和 Transwell 侵袭测定分别探讨了 Rap2B 对 HCC 恶性生物学行为的影响。Ki67、基质金属蛋白酶 (MMP)-2、MMP-9 和 cleaved caspase-3 的蛋白水平以及 ERK1/2 和 PTEN/PI3K/Akt 通路的改变通过 Western blot 分析进行了鉴定。通过进行体内实验进一步验证了 Rap2B 对 HCC 肿瘤发生的作用。我们发现 Rap2B 水平在 HCC 组织和细胞中上调。Rap2B 沉默导致 HCC 细胞增殖和侵袭能力降低，凋亡增加。此外，异种移植肿瘤实验表明 Rap2B 沉默抑制了体内 HCC 异种移植肿瘤的生长。此外，我们发现 Rap2B 敲低显著抑制了 HCC 细胞和异种移植肿瘤组织中的 ERK1/2 和 PTEN/PI3K/Akt 级联反应。总之，Rap2B 敲低抑制了 HCC 恶性进展，这涉及抑制 ERK1/2 和 PTEN/PI3K/Akt 通路。我们的研究结果有助于理解 Rap2B 在 HCC 进展中的分子机制。
