TLR4 SiRNA Inhibits Proliferation,Invasion And Migration In Colorectal Cancer Cells By Downregulating ACAT1 Expression

AIMS:TLR4(Toll like receptor 4)plays a key role in the process in the occurrence and development of tumor.At present,many related studies have confirmed that the TLR4 participated in several process of the occurrence and development of variety of tumor,such as participated in the tumor inflammation,the proliferation and the invasion of cancer cells.Some research has shown that high expression of ACAT1(Acetyl-coenzyme A acyltransferase 1)can promote the proliferation of human colon cancer cells SW620,and it is associated with tumor invasive is obvious.Colorectal cancer is one of the most common gastrointestinal malignancy,and it has higher incidence and mortality in middle-aged adults.But the interaction mechanism between TLR4 and ACAT1 in the occurrence and development of the colorectal cancer,has still not been fully elucidated.In this study was to investigate the in vitro experiment,the influence of TLR4 on ACAT1 in human colorectal cancer cells(HT29 and SW480)and its effects on cancer cell proliferation,invasion and migration.Then target therapy for colorectal cancer.MAIN METHODS:All the cell lines were divided into six groups: 1.the liposomes control group;2.the negative control group(TLR4 si RNA);3.the experiment group 1(TLR4si RNA);4.the empty control group(p LV-Neo);5.the negative control group(TLR4si RNA p LV-Neo);6.the experiment group 2(TLR4 si RNA p LV-Neo-ACAT1).We adopted Reverse transcriptase-polymerase chain reaction(RT-PCR)and Western blot to detected the expression of TLR4 and ACAT1 in colorectal cancer tissues and cell lines.Adopted CCK8 kits(Cell Counting Kit 8)and Transwell inser to detect and evaluate the changes of the proliferation,invasion and migration ability in human colorectal cancer cells(HT29 and SW480)after used the TLR4 small interfering RNA(TLR4 si RNA)to silence TLR4.Used RT-PCR and Western blot to research the relationship between the TLR4 and ACAT1.KEY FINDINGS:This experiment research results found that the TLR4 and ACAT1 m RNA and protein expression significantly increased in colorectal cancer tissue relative to the tissue adjacent to carcinoma(TLR4 m RNA: 2.395±0.2477 and 1.093±0.07575P<0.0001;ACAT1 m RNA: 2.196 ±0.1895 and 1.093±0.07575 P<0.0001).The TLR4 and ACAT1 expression are also raised(P < 0.01)in human colorectal cancer cell line(HT29,SW480,Caco 2,DLD-1)relative to the normal colorectal cell lines FHC.Using RT-PCR found that the TLR4 in human colorectal cancer cell lines HT29 and SW480 m RNA had be down-regulated expression after it had be silenced P<0.05(HT29 0.3367 ±0.1068 and 1.067 ±0.1139 p= 0.0095;SW480 0.4467±0.08969 and 0.9433 ±0.08253 p= 0.0152).Meanwhile,TLR4 si RNA can reduce the expression of ACAT1 in colorectal cancer HT29 cell(m RNA: 0.3500±0.1457 and1.017±0.145 P=0.0316;Protein: 0.5233±0.05207 and 1.140±0.1058 P=0.0064).And the use of p LV Neo-ACAT1(ACAT1 slow virus gene expression vector)could make the ACAT1 overexpression which can remove the inhibition of TLR4 si RNA in colorectal cancer.SIGNIFICANCE:TLR4 si RNA suppress the proliferation,invasion and migration by influencing the expression of ACAT1 in colorectal cancer cells shows that the TLR4 may could be an important potential gene target therapy for colorectal cancer.