Dataset Information

SOX9-activated FARSA-AS1 predetermines cell growth, stemness, and metastasis in colorectal cancer through upregulating FARSA and SOX9

ABSTRACT: SRY-box transcription factors (SOXs) are effective inducers for the formation of stem-like phenotypes. As a member of SOX family, SOX9 (SRY-box transcription factor 9) has been reported to be highly expressed and exert oncogenic functions in multiple human cancers. In this study, we hypothesized that SOX9 could regulate the function of cancer stem/initiating cells (CSCs) to further facilitate the progression of colorectal cancer (CRC). Then, stable transfection of shRNAs was used to silence indicated genes. Loss-of-function experiments were conducted to demonstrate the in vitro function of CRC cells. In vivo study was conducted to determine the changes in tumorigenesis and metastasis in vivo. Bioinformatics analyses and mechanistic experiments were employed to explore the downstream molecules. Presently, GEPIA data indicated that SOX9 was upregulated in 275 COAD (colon adenocarcinoma) samples relative to 349 normal tissues. Besides, we also proved the upregulation of SOX9 in CRC cell lines (HCT15, SW480, SW1116, and HT-29) compared to normal NCM-460 cells. Silencing of SOX9 suppressed cell growth, stemness, migration, and invasion. Mechanistically, SOX9 activated the transcription of lncRNA phenylalanyl-tRNA synthetase subunit alpha antisense RNA 1 (FARSA-AS1), while FARSA-AS1 elevated SOX9 in turn by absorbing miR-18b-5p and augmented FARSA via sequestering miR-28-5p. Furthermore, loss of FARSA-AS1 hindered malignant phenotypes in vitro and blocked tumor growth and metastasis in vivo. Notably, we testified that FARSA-AS1 aggravated the malignancy in CRC by enhancing SOX9 and FARSA. Our study unveiled a mechanism of SOX9-FARSA-AS1-SOX9/FARSA loop in CRC, which provides some clews of promising targets for CRC.

SUBMITTER: Zhou T

PROVIDER: S-EPMC7736271 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundGrb2-associated binder 2 (Gab2) is a scaffolding protein that serves as a critical signaling amplifier downstream of tyrosine kinase receptors. Our previous study has shown that Gab2 induces epithelial-to-mesenchymal transition (EMT) and promotes metastasis in colorectal cancer (CRC). However, the role of Gab2 in CRC growth and angiogenesis remains unclear.MethodsThe expression of vascular endothelial growth factor (VEGF) in different colorectal tissues was detected by immunohistochemistry and qRT-PCR to evaluate its correlation with Gab2. Lentiviral vectors bearing Gab2 gene and its small interfering RNAs were constructed and transfected into CRC cell lines. The effects of Gab2 on the cell proliferation in vitro and tumorigenesis in vivo, were examined via CCK‑8 assay, colony formation assay as well as tumorigenicity assay respectively. Moreover, to assess its potential role in tumor growth and angiogenesis, the expression of Ki67, CD34 and vascular endothelial growth factor receptor-2 (VEGFR2) were detected by immunohistochemistry in CRC cells tumors. Finally, we evaluated the impact of Gab2 on the expression of c-Myc and VEGF, and the probable effect of mechanistic targeted extracellular signal-regulated kinase (ERK) pathway in suppressing tumor growth and angiogenesis.ResultsUp-regulation of Gab2 expression was found to be positively correlated with VEGF in CRC tissues. Exogenous expression of Gab2 obviously promoted, whereas silencing of Gab2 inhibited, proliferation and clone formation of human CRC cells in vitro. Of note, Gab2 enhanced tumorigenesis and tumor growth in mouse xenografts with high Ki67 expression, and led to an increased vessel density with strong CD34 and VEGFR2 activity. In addition, elevated Gab2 expression obviously up-regulated the expression of VEGF, and stimulated the activation of its downstream genes, ERK1/2 and c-Myc in CRC cells. Instead, down-regulated Gab2 expression significantly reduced the levels of VEGF, and inhibited the transduction of ERK/c-Myc pathway. Finally, we revealed that mechanistic target of mitogen-activated protein kinase (MEK) could attenuate Gab2-induced tumor growth and angiogenesis via altering VEGF and c-Myc levels.ConclusionsThe results from our study suggest that Gab2 promotes intestinal tumor growth and angiogenesis through upregulation of VEGF expression mediated by the MEK/ERK/c-Myc pathway.

Dataset Information

SOX9-activated FARSA-AS1 predetermines cell growth, stemness, and metastasis in colorectal cancer through upregulating FARSA and SOX9

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets