miR-144-3p Targets FosB Proto-oncogene, AP-1 Transcription Factor Subunit (FOSB) to Suppress Proliferation, Migration, and Invasion of PANC-1 Pancreatic Cancer Cells

Abstract

This study aimed to investigate the role of miR-144-3p in pancreatic cancer (PC) carcinogenesis and to explore the mechanism of its function in PC. miR-144-3p was downregulated in PC tissues and cells. miR-144-3p overexpression significantly inhibited PC cell proliferation, migration, and invasion. FosB proto-oncogene, AP-1 transcription factor subunit (FOSB) was a target gene of miR-144-3p. miR-144-3p could repress PC cell proliferation, migration, and invasion by inhibiting the expression of FOSB. In conclusion, miR-144-3p plays an important role in PC cell proliferation, migration, and invasion by targeting FOSB. miR-144-3p may provide a new target for the development of therapeutic agents against PC.

Figure 1

The relative expression levels of miR-144-3p in pancreatic cancer (PC) tissues and cells detected by real-time (RT)-PCR. (A) miR-144-3p was downregulated in PC tissues compared with the adjacent noncancerous pancreatic tissues. (B) Relative miR-144-3p expression in the PANC-1 PC cell line was significantly lower than that in the SW-1990 and BxPC-3 cell lines. *p < 0.05, **p < 0.01 compared with control.

Figure 2

miR-144-3p inhibited proliferation, migration, and invasion of PANC-1 cells. (A) The relative expression levels of miR-144-3p after transfection of the miR-141 mimic with Lipofectamine 2000 detected by quantitative (q)RT-PCR. (B) The proliferation of PANC-1 cells was significantly inhibited by overexpressed miR-144-3p detected by MTT assay. (C) Overexpression of miR-144-3p reduced cell colony formation. (D) Overexpression of miR-144-3p decreased migration of PANC-1 cells detected by Transwell assay. (E) Overexpression of miR-144-3p decreased invasion of PANC-1 cells detected by Transwell assay. *p < 0.05, **p < 0.01, ***p < 0.001 compared with control.

Figure 3

miR-144-3p directly targets the FOSB gene. (A) The gene sequences of FOSB regulated by miR-144-3p. (B) The expression level of FOSB was upregulated in PC tissues detected by RT-PCR and Western blot. (C) The relative FOSB expression in the PANC-1 PC cell line was significantly higher than that in the SW-1990 and BxPC-3 cell lines. (D) The relative luciferase activities in wild-type 3′-UTR of FOSB and mutant-type 3′-UTR of FOSB in transfected cells. (E) The relative mRNA expression level of FOSB after cell transfection detected by RT-PCR. (F) The relative protein expression level of FOSB after cell transfection detected by Western blot. *p < 0.05, **p < 0.01, ***p < 0.001 compared with control. ns, not significant.

Figure 4

Effect of FOSB on PANC-1 cell proliferation, migration, and invasion. (A) The relative protein expression level of FOSB after cell transfection with siFOSB or anti-miR-144-3p. (B) Growth curve among siFOSB, siFOSB + anti-miR-144-3p, and their appropriate controls. (C) Colony formation among siFOSB, siFOSB + anti-miR-144-3p, and their appropriate controls. (D) Transwell assay indicated that the migration ability of PANC-1 cells was markedly attenuated by downregulation of FOSB. (E) Transwell assay indicated that siFOSB significantly decreased the invasion ability of PANC-1 cells. (F) Effect of miR-144-3p mimic or FOSB on the expressions of COX2, VEGF, MMP2, and MMP9 detected by Western blot. *p < 0.05, **p < 0.01, ***p < 0.001, #p < 0.05 compared with control.