ABSTRACT
ObjectiveTo observe the effect of Xianlian Jiedu prescription （XLJDP） on the proliferation， apoptosis， and migration of cancer-relative endothelial （CRE） cells， and to decipher the mechanism of XLJDP in regulating angiopoietin2 （Ang2） to maintain CRE cell homeostasis and inhibit tumor neovascularization. MethodHuman umbilical vein endothelial cell line （HUVEC-c） was induced into CRE cells in the human colorectal cancer HCT-116 cell-conditioned medium. The CRE cells were assigned into the blank group， conditioned medium group， and XLJDP groups （1， 2， 3 g·L-1） and treated for 48 h. The proliferation of CRE cells was detected by methyl thiazolyl tetrazolium （MTT） colorimetry. The morphological changes of CRE cells were observed via an inverted microscope. The apoptosis rate was detected by flow cytometry. Wound healing test and Transwell migration assay were employed to detect the 2D/3D migration ability of CRE cells. The protein levels of vimentin， N-cadherin， matrix metalloproteinase-9 （MMP-9）， and Ang2 in CRE cells were measured by Western blot. ResultThe MTT results showed that the cell viability was higher in the conditioned medium group than in the blank group （P<0.05）. Compared with the conditioned medium group， XLJDP decreased the cell proliferation rate （P<0.01） and changed the cell morphology. The total apoptosis rates of all the XLJDP groups were higher than that of the conditioned medium group （P<0.01）. The 2D and 3D migration abilities of the conditioned medium group were higher than those of the blank group （P<0.05， P<0.01）. Compared with the conditioned medium group， XLJDP at all the concentrations weakened the 2D migration ability （P<0.01） and medium- and high-concentration XLJDP weakened the 3D migration ability （P<0.01）. The protein levels of N-cadherin， Vimentin， MMP-9， and Ang2 were up-regulated in the conditioned medium group compared with those in the blank group （P<0.05， P<0.01）. Compared with the conditioned medium group， XLJDP at all the concentrations down-regulated the protein level of Ang2 （P<0.05， P<0.01）， and medium- and high-concentration XLJDP down-regulated those of N-cadherin， vimentin， and MMP-9 protein （P<0.01）. ConclusionXLJDP may inhibit the proliferation， migration， differentiation， and apoptosis of CRE cells by down-regulating the expression of Ang2， inhibiting tumor neovascularization， and maintaining the cell homeostasis.
ABSTRACT
ObjectiveTo study the effect of Xianlian Jiedu prescription （XLJDP） on the activation of nuclear transcription factor-κB （NF-κB） signaling pathway induced by bromodomain-containing protein 4 （Brd4） in hypoxic microenvironment and to explore its mechanism in inhibiting the proliferation of colorectal cancer HT-29 cells. MethodThe human colorectal cancer HT-29 cells were cultured in a hypoxic incubator or normoxia incubator and treated with XLJDP at 0.8，1，1.2，1.6，3.2，6.4，and 12.8 g·L-1 for 48 h， respectively. Following the detection of cell vitality using methyl thiazolyl tetrazolium （MTT） colorimetry， the effects of XLJDP （1.25，2.5，and 5 g·L-1） on the cell mitochondrial membrane potential were determined using a fluorescent probe （JC-1）， and the apoptosis of colorectal cancer HT-29 cells was detected by flow cytometry. The cell colony formation assay and 5-ethynyl-2'-deoxyuridine （EDU） staining were conducted to test the proliferation of colorectal cancer HT-29 cells. The Western blot was carried out to measure the expression levels of Brd4 and its downstream relevant proteins such as c-Myc and hexamethylene bisacetamide-inducible protein 1 （HEXIM1）， as well as the effects of XLJDP on related proteins in the NF-κB signaling pathway. ResultCompared with the blank control group， XLJDP at 0.8，1，1.2，1.6，3.2，6.4，and 12.8 g·L-1 inhibited the vitality of colorectal cancer HT-29 cells （P<0.05 ， P<0.01）， with the median inhibitory concentration （IC50） under the hypoxic condition higher than that under the normoxia condition. Compared with the blank control group， XLJDP at 1.25，2.5，and 5 g·L-1 significantly decreased the mitochondria membrane potential， enhanced the apoptosis （P<0.05，P<0.01）， and lowered the number of cell colonies and also the EDU-positive cells （P<0.05， P<0.01）. The results of Western blot showed that compared with the blank control group， XLJDP at 1.25，2.5，and 5 g·L-1 down-regulated Brd4， c-Myc， p-NF-κB p65， and p-IκBα protein expression to varying degrees and up-regulated the expression of HEXIM1 （P<0.05， P<0.01）. ConclusionIn the hypoxic microenvironment， XLJDP inhibits the proliferation of colorectal cancer HT-29 cells regulated by Brd4， which may be related to its inhibition of the activation of NF-κB signaling pathway.