Discovery of metastasis-associated biomarkers in ovarian cancer using SELDI-TOF: An in vitro and clinical study

OBJECTIVE To identify metastasis-related biomarkers in human ovarian cancer cell lines and in serum. METHODS We isolated total protein from cell lysis solutions and cultured supernatants from 2 human ovarian cancer cell lines and used SELDI-TOF-MS to detect the differential expression of the proteins in the 2 cell lines. The proteomic spectra were generated using weak cation exchange chips. The biomarkers were validated by analyzing serum proteins or peptides in ovarian cancer patients, relapsed ovarian cancer patients, patients with benign ovarian tumors, and healthy people. RESULTS Four proteins in the culture supernatant from HO-8910PM cells were up-regulated, relative to the culture supernatant of HO-8910 cells. One protein （3,144 Da m/z value） was up-regulated in both the cell lysis solution and in the culture supernatant of HO-8910PM cells. In addition, expression of the 3,144 Da m/z protein differed significantly between serum from the 26 ovarian cancer patients, from the 22 relapsed ovarian patients and from the 37 healthy women （P 〈 0.01）. However, there was no difference between patients with benign ovarian tumors and healthy people （P 〉 0.5）. CONCLUSION Ovarian cancer cell lines with high or low metastatic potential have distinct protein profiles. Protein 3,144 Da m/z could be a useful biomarker for diagnosing ovarian cancer metastasis.     

Down-Regulation of Notchl and NF-κB by Curcumin in Breast Cancer Cells MDA-MB-231

Objective:To test whether the down-regulation of Notch1 gene expression by curcumin could inhibit cell growth and induce apoptosis,which may be associated mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods:Breast cancer cell lines MDA-MB-231 were cultured in vitro and treated with different dosages of curcumin(0,1.25,5.0,20.0μmol/L)for dose-dependent assay and different time(0,24,48,72 h)at the dosage of 5.0μmol/L for time course assay.The changes of the mRNA and protein expression of Notch1 and NF-κB were measured by RT-PCR and Western Blot,and MTT assay was used to measure the change of proliferation. Results:The mRNA and protein levels of Notch 1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin(P＜0.05),and with the extension of time course(P＜0.05).These changes suggested a dose- and time-dependent manner.The proliferation rate of cells also was significantly inhibited(P＜0.05). Conclusion:The current results show that the Notch-1 signaling pathway is associated mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer.     

黄芩素对人乳腺癌MDA-MB-231细胞株SATB1表达的影响(英文)

Baicalein had been proved to have anti-cancer activity in vitro and in vivo, including the inhibition of malignant proliferation, migration, adhesion and invasion of many kinds of cancer cells. The special AT-rich sequence binding protein 1 （SATB1） is a tissue-specific expression of nuclear matrix-binding protein and is reported to be a breast cancer ＂gene group organizer＂. Previous studies have shown that SATB1 is involved in the growth, metastasis and prognosis of breast cancer. The present study was aimed to investigate whether baicalein inhibits the proliferation and migration of MDA-MB-231 human breast cancer cells through down-regulation of the SATB1 expression. Methods： MDA-MB-231 cells were treated for 24 h, 48 h and 72 h with various concentrations of baicalein （0, 5, 10, 20, 40 and 80 pM） respectively. Then, the proliferation and migration of MDA-MB-231 cells following treatment with baicalein were determined using colorimetric 3-（4, 5-dimethylthia- zol-2-yl） 2, 5-diphenyltetrazolium bromide （MTT） and wound healing assays. Thereafter, western blot analysis was performed to detect the changes of SATB1 protein expression in MDA-MB-231 cells. Results： Along with the prolongation of time and increase of drug concentration, inhibitory effect of baicalein on proliferation and migration of MDA-MB-231 cells gradually in- creased, in a time.- and dose- dependent manner （P 〈 0.05）. Meanwhile, after treated with baicalein in different concentrations for 48 h, the level of SATB1 protein expression of MDA-MB-231 cells decreased obviously, in a dose-dependent manner （P 〈 0.05）. Conclusion： Baicalein inhibits breast cancer cell proliferation and suppresses its invasion and metastasis by reducing cell migration possibly by down-regulation of the SATB1 protein expression, indicating that baicalein is a potential therapeutic agent for human breast cancer.     

Induction of apoptosis of human ovarian cancer cells by SGI-1776 combination with DDP in sub-toxic concentration in vitro

Objective： The aim of the study was to investigate the effect of SG1-1776 combination with DDP in sub-toxic concentration on induction of apoptosis of human ovarian cancer HO-8910 ceiis in vitro and to unravei the associated mechanisms. Methods： Human ovarian cancer HO-8910 cells were cultured in vitro. The inhibitory effect of SG1-1776 combination with DDP in sub-toxic concentration on induction on viability of human ovarian cancer HO-8910 cells was evaiuated by the MTT assay. Cell apoptosis rate was analyzed by flow cytometry. The proteins expression level related to apoptosis were analyzed by Western blot. Results： SG1-1776 combination with DDP in sub-toxic concentration significantiy inhibited the proliferation of human ovarian cancer HO-8910 cells, and proliferation inhibition rate was increased drastically compared with normai saline （NS） group or DDP group in sub-toxic concentration or SG1-1776 group in sub-toxic concentration （P 〈 0.01）. Apoptosis rate markedly increased after the treatment of SG1-1776 combination with DDP in sub-toxic concentration for 48 h. Western blot showed that the expression of bcl-2 protein was down-regulated and protein level of Bax and Cyto-c were depressed by SG1-1776 combination with DDP in sub-toxic concentration. Cenclusion： SG1-1776 combination with DDP in sub-toxic concentration could inhibit the cell proliferation and lead to cell apoptosis inhuman ovarian cancer HO-8910 cells, and its mechanism may be related to through mitochondrial apoptotic pathway.     

HEDGEHOG-GLI1 signaling regulates human glioma growth, cancer stem cell self-renewal, and tumorigenicity

Cancer stem cells are rare tumor cells characterized by their ability to self-renew and to induce tumorigenesis. They are present in gliomas and may be responsible for the lethality of these incurable brain tumors. In the most aggressive and invasive type, glloblastoma multiforme （GBM）, an average of about one year spans the period between detection and death [1]. The resistence of gliomas to current therapies may be related to the existence of cancer stem cells [2-6]. We find that human gliomas display a stemness signature and demonstrate that HEDGEHOG （HH）-GLI signaling regulates the expression of sternness genes in and the self-renewal of CD133 （＋） glioma cancer stem cells. HH-GLI signaling is also required for sustained glioma growth and survival. It displays additive and synergistic effects with temozolomide （TMZ）, the current hemotherapeutic agent of choice. TMZ, however, does not block glioma stem cell self-renewal. Finally, interference of HH-GLI signaling with cyclopamine or through lentiviral-mediated silencing demonstrates that the tumorigenicity of human gliomas in mice requires an active pathway. Our results reveal the essential role of HH-GLI signaling in controlling the behavior of human glioma cancer stem cells and offer new therapeutic possibilities.     

亚毒性浓度顺铂联合紫花牡荆素体外诱导人卵巢癌细胞调亡(英文)

Objective: The aim of the study was to investigate the effect of Casticin (CAS) combination with Cisplatin (DDP) in sub-toxic concentration on apoptosis of human ovarian cancer HO-8910 cells in vitro and unravel the associated mechanisms. Methods: Human ovarian cancer HO-8910 cells were cultured in vitro. The inhibitory effect of CAS combination with DDP in sub-toxic concentration on viability of human ovarian cancer HO-8910 cells was evaluated by the MTT assay. Morphological changes of cell apoptosis were detected by Hoechst 33258 staining assay. Cell apoptosis rate was analyzed by flow cytometry. The protein expression level was analyzed by Western blot. Results: CAS in sub-toxic concentration and DDP in sub-toxic concentration could slightly inhibit Human ovarian cancer HO-8910 cells, but CAS combination with DDP in sub-toxic concentration significantly inhibited the growth of HO-8910 cells, and growth inhibition rate was increased drastically compared with the control group (P﹤0.01), and the inhibiting effect showed synergistic action. Human ovarian cancer HO-8910 cells showed the typical morphological changes of apoptosis and apoptosis rate markedly increased when they were exposed to CAS combination with DDP in sub-toxic concentration for 48 h. Western blot showed that the expression of bcl-2 protein was down-regulated and protein level of caspase-3 was activated by CAS combination with DDP in sub-toxic concentration. Conclusion: CAS combination with DDP in sub-toxic concentration could inhibit the cells growth and lead to cell apoptosis in human ovarian cancer HO-8910 cells. And the down-regulation of bcl-2 protein expression and activation of caspase-3 protein might contribute to CAS combination with DDP in sub-toxic concentration in human cancer HO-8910 cells.     

Inhibition of proliferation of human breast cancer MCF-7 cells by small interference RNA against LRP16 gene

Objective: Our previous studies have firstly demonstrated that 17β-E2 up-regulates LRP16 gene expression in human breast cancer MCF-7 cells, and ectopic expression of the LRP16 gene promotes MCF-7 cells proliferation. Here, the effects of the LRP16 gene expression on growth of MCF-7 human breast cancer cells and the mechanism were further studied by establishing two stably LRP16-inhibitory MCR-7 cell lines. Methods: Hairpin small interference RNA (siRNA)strategy, bY which hairpin siRNA was released by U6 promoter and was mediated by pLPC-based retroviralvector, was adopted to knockdown endogenous LRP16 level in MCF-7 cells. And the hairpin siRNA against green fluorescence protein (GFP) was used as the negative control. The suppressant efficiency of the LRP16 gene expression was confirmed by Nothern blot.Cell proliferation assay and soft agar colony formation assay were used to determine the status of the cell sproliferation. Cell cycle checkpoints including cyclin E and cyclin D1 were examined by Western blot. Results:The results from cell proliferation assays suggested that down-regulation of LRP16 gene expression is capable of inhibiting MCF-7 breast cancer cell growth and down-regulation of the LRP16 gene expression is able to inhibit anchorage-independent growth of breast cancer cells in soft agar. We also demonstrated that cyclin E and cyclin D1 proteins were much lower in the LRP16-inhibitory cells than in the control cells.Conclusion: These data suggest that LRP16 gene play an important role in MCF-7 cells proliferation by regulating the pathway of the G1/S transition and may function as an important modulator in regulating the process of tumorigenesis in human breast.     

Effects of Triptolide on Cell Proliferation and CXCR4 Expression in Burkitt＇s Lymphoma Raji Cells In Vitro

Objective： To investigate the inhibitory effects of triptolide on cell proliferation and CXCR4 expression in Burkitt＇s lymphoma cell line Raji cells. Methods： The effects of triptolide on the growth of Raji cells were studied by 3-（4, 5-Dimethyl-2-thiazolyl）-2, 5-diphenyl-2H-tetrazolium（MTT） assay. The effects of triptolide on CXCR4 expression on Raji cells were studied by flow cytometric analysis. Chemotaxis assays were performed to observe the effects of triptolide on migration of Raji cells towards recombinant human SDF-1α （rhSDF-1α） in vitro. Results： Triptolide inhibited the proliferation of Raji cells in a dose- and time-dependent way with a 24-h IC50 value of 43.06 nmol/L and a 36-h IC50 value of 25.08 nmol/L. Triptolide could downregulate the CXCR4 expression on Raji cells in a dose-dependent manner. Furthermore, chemotaxis assays showed that triptolide could block the migration of Raji cells to rhSDF-1α in vitro, and the inhibition was dose-dependent. Conclusion： Triptolide could inhibit the proliferation and migration of Raji cells in vitro. The underlying anti-tumor mechanism of triptolide might be related to the anti-proliferative effect and the blockage of SDF-1/CXCR4 axis.     

BYSL contributes to tumor growth by cooperating with the mTORC2 complex in gliomas

Objective:BYSL,which encodes the Bystin protein in humans,is upregulated in reactive astrocytes following brain damage and/or inflammation.We aimed to determine the role and mechanism of BYSL in glioma cell growth and survival.Methods:BYSL expression in glioma tissues was measured by quantitative real-time PCR,Western blot,and immunohistochemistry.In vitro assays were performed to assess the role of BYSL in cell proliferation and apoptosis.Protein interactions and co-localization were determined by co-immunoprecipitation and double immunofluorescence.The expression and activity of the AKT/m TOR signaling molecules were determined by Western blot analysis,and the role of BYSL in glioma growth was confirmed in an orthotopic xenograft model.Results:The BYSL m RNA and protein levels were elevated in glioma tissues.Silencing BYSL inhibited glioma cell proliferation,impeded cell cycle progression,and induced apoptosis,whereas overexpressing BYSL protein led to the opposite effects.We identified a complex consisting of BYSL,RIOK2,and m TOR,and observed co-localization and positive correlations between BYSL and RIOK2 in glioma cells and tissues.Overexpressing BYSL or RIOK2 increased the expression and activity of AKT/m TOR signaling molecules,whereas downregulation of BYSL or RIOK2 decreased the activity of AKT/m TOR signaling molecules.Silencing BYSL or RIOK2 decreased the growth of the tumors and prolonged the lifespan of the animals in an orthotopic xenograft model.Conclusions:High expression of BYSL in gliomas promoted tumor cell growth and survival both in vitro and in vivo.These effects could be attributed to the association of BYSL with RIOK2 and m TOR,and the subsequent activation of AKT signaling.     

沉默轴突导向蛋白4D基因对卵巢癌SKOV3细胞恶性生物学行为的影响

Objective To observe the effect of DNA Sema4D gene silencing by RNA interfering on the proliferation, migration and invasion of human ovarian cancer SKOV3 cells, and to study the effect of pshRNASema4D on the growth of SKOV3 cells in transplanted tumor in nude nice. Methods Recombinant plasmid pshRNASema4D-A, B and C were respectively transfected into SKOV3 cells by lipofetamine 2000, while cells transfected by plasmid vector pcDNA3.1 and cells untreated as control groups. RT-PCR was adopted to select the recombinant plasmid which showed the most optimal inhibition effect. RT-PCR and Western blotwere used to detected the mRNA and protein expression of Sema4D in SKOV3 cells tranfected for 24, 48 and 72 hours. MTT assay was used to investigate the proliferation of the SKOV3 cells after trasnsfection. Transwell cell migration and invasion assays were used to investigate the migration and invasion abilities of the SK0V3 cells after trasnsfection. Human ovarian cancer model was established in nude mice, and the nude mice were treated with pshRNASema4D-B once every 3 days for 3 weeks. The bulk of the transplanted tumor was measured. Results Three Sema4D-targeted short hairpin RNA (shRNA) A, B and C were successfully inserted into the plasmid vector pshRNA, and the coding sequences of the obtained shRNA were consistent with the designed fragment. The results indicated that both recombinant plasmid pshRNASema4D-A and B could effectively knock down the expression of Sema4D gene in human ovarian cancer cells, of which pshRNASema4D-B was the better choice, while no effect of pshRNASema4D-C was seen. RT-PCR results showed that the relative mRNA expression of Sema4D gene in SKOV3 cells transfected with pshRNA-Sema4D for 24, 48 and 72 hours were 0. 401 ±0.051, 0. 120 ±0.035 and 0.014 ±0. 015, respectively, which were significantly lower than that in SKOV3 cells transfected by empty vector and non-transfected cells at 72 hours after transfection. (0.521 ±0.019, 0.536 ±0.040,respectively, P<0.05). The Westen blot analysis manifested that the relative expression of Sema4D protein of SKOV3 cells transfected by pshRNASema4D for 24, 48 and 72 hours were 0. 196 ± 0. 023, 0. 074 ± 0. 015 and 0. 040 ± 0.014, respectively, which were significantly lower than that in SKOV3 cells transfected by empty vector and non-transfected cells at 72 hours after transfection. (0. 275 ± 0. 009, 0. 282 ± 0. 015, respectively, P < 0. 05 ). Comparing with the empty vector-transfected and non-transfected cells, the proliferation, invasion and migration ability of SKOV3 cells transfected with pshRNA-Sema4D were obviously weakened. The pshRNASema4D-B significantly suppressed the growth of the SKOV3 cells-transplanted tumors in nude mice, and the IR( inhibitory rate ) of pshRNASema4D-B group was ( 61.0 ± 3.3 ) % ( P < 0.05). Conclusions Sema4D can be successfully silenced by RNA interfering in human ovarian cancer SKOV3 cells. Downregulation of Sema4D can inhibit the proliferation, migration and invasion of ovarian cancer cells. The pshRNASema4D can significantly suppress the growth in transplanted tumor of human ovary cancer in nude mice. Sema4D may become a candidate gene of gene therapy of human ovarian cancer.     

Clinicopathological Significance of E-cadherin and PCNA Expression in Hunman Non-small Cell Lung Cancer

OBJECTIVE This study was designed to assess E-cadherin (E-cad)and proliferating cell nuclear antigen(PCNA)expression as well as their clinicopathological significance in hunman non- small cell lung cancers(NSCLCs).Possible molecular mechanisms of differentiation and metastasis of NSCLCs are discussed. METHODS Immunohistochemical and immunofluorescence double staining were performed to examine the expression of E-cad and PCNA in 68 primary NSCLCs cases. RESULTS The E-cad expression in squamous cell carcinomas and adenocarcinomas showed no significant difference.E-cad expression had a positive correlation with the histological- differentiated grade.A significant difference of E-cad expression was found between metastatic and non-metastatic groups.PCNA expression in squamous cell carcinomas and adenocarcinomas showed no significant difference.The PCNA expression had a reverse correlation with the histological-differentiated grade.A significant difference of PCNA expression was found between metastatic and non-metastatic groups.The E-cad and PCNA expression presented a reverse correlation. CONCLUSION E-cad expression is not associated with the histological type of NSCLC,but is associated with differentiation and metastasis of the cancer.Down-regulation of E-cad expression affects the proliferation of cancer cells.Conjoint analysis of E-cad and PCNA expression is a good way to evaluate tumor biological behavior.     

沉默轴突导向蛋白4D基因对卵巢癌SKOV3细胞恶性生物学行为的影响

Objective To observe the effect of DNA Sema4D gene silencing by RNA interfering on the proliferation, migration and invasion of human ovarian cancer SKOV3 cells, and to study the effect of pshRNASema4D on the growth of SKOV3 cells in transplanted tumor in nude nice. Methods Recombinant plasmid pshRNASema4D-A, B and C were respectively transfected into SKOV3 cells by lipofetamine 2000, while cells transfected by plasmid vector pcDNA3.1 and cells untreated as control groups. RT-PCR was adopted to select the recombinant plasmid which showed the most optimal inhibition effect. RT-PCR and Western blotwere used to detected the mRNA and protein expression of Sema4D in SKOV3 cells tranfected for 24, 48 and 72 hours. MTT assay was used to investigate the proliferation of the SKOV3 cells after trasnsfection. Transwell cell migration and invasion assays were used to investigate the migration and invasion abilities of the SK0V3 cells after trasnsfection. Human ovarian cancer model was established in nude mice, and the nude mice were treated with pshRNASema4D-B once every 3 days for 3 weeks. The bulk of the transplanted tumor was measured. Results Three Sema4D-targeted short hairpin RNA (shRNA) A, B and C were successfully inserted into the plasmid vector pshRNA, and the coding sequences of the obtained shRNA were consistent with the designed fragment. The results indicated that both recombinant plasmid pshRNASema4D-A and B could effectively knock down the expression of Sema4D gene in human ovarian cancer cells, of which pshRNASema4D-B was the better choice, while no effect of pshRNASema4D-C was seen. RT-PCR results showed that the relative mRNA expression of Sema4D gene in SKOV3 cells transfected with pshRNA-Sema4D for 24, 48 and 72 hours were 0. 401 ±0.051, 0. 120 ±0.035 and 0.014 ±0. 015, respectively, which were significantly lower than that in SKOV3 cells transfected by empty vector and non-transfected cells at 72 hours after transfection. (0.521 ±0.019, 0.536 ±0.040,respectively, P<0.05). The Westen blot analysis manifested that the relative expression of Sema4D protein of SKOV3 cells transfected by pshRNASema4D for 24, 48 and 72 hours were 0. 196 ± 0. 023, 0. 074 ± 0. 015 and 0. 040 ± 0.014, respectively, which were significantly lower than that in SKOV3 cells transfected by empty vector and non-transfected cells at 72 hours after transfection. (0. 275 ± 0. 009, 0. 282 ± 0. 015, respectively, P < 0. 05 ). Comparing with the empty vector-transfected and non-transfected cells, the proliferation, invasion and migration ability of SKOV3 cells transfected with pshRNA-Sema4D were obviously weakened. The pshRNASema4D-B significantly suppressed the growth of the SKOV3 cells-transplanted tumors in nude mice, and the IR( inhibitory rate ) of pshRNASema4D-B group was ( 61.0 ± 3.3 ) % ( P < 0.05). Conclusions Sema4D can be successfully silenced by RNA interfering in human ovarian cancer SKOV3 cells. Downregulation of Sema4D can inhibit the proliferation, migration and invasion of ovarian cancer cells. The pshRNASema4D can significantly suppress the growth in transplanted tumor of human ovary cancer in nude mice. Sema4D may become a candidate gene of gene therapy of human ovarian cancer.     

EFFECTS AND MECHANISMS OF ENDOSTATIN ON THE GROWTH OF OVARIAN CANCER SKOV3 CELLS IN VITRO AND IN VIVO

Objective： To evaluate the inhibitory effect of Endostatin on ovarian cancer cell line SKOV3 and to investigate the possible mechanism of the inhibition. Methods： Using MTT, transmission electron microscope （TEM） and immunocytochemistry, the effects of Endostatin on the proliferation of SKOV3 cells were studied. Nude mice were subcutaneously implanted with SKOV3 cells. The cell apoptosis of implanted tumor was detected by TUNEL and TEM. The expressions of bcl-2 and bax in implanted tumor tissues were measured by RT-PCR and immunohistochemistry. Results： Endostatin significantly inhibited the proliferation of SKOV3 cells in vitro （P〈0.01） and induced cell apoptosis, whereas the expressions of bcl-2 and bax were not changed obviously in SKOV3 cell treated with Endostatin. The mean tumor weight of Endostatin treated group was markedly lower than that of PBS control group （P〈0.05）. The expression of bcl-2 was down-regulated in Endostatin treated group, but bax was not influenced. Conclusions： The results demonstrated that Endostatin might have anti-tumor effect on ovarian carcinoma. One of the important mechanisms of Endostatin effect of anti-angiogenic and anti-tumor activities might involve regulating the bcl-2/bax expression and inducing apoptosis.     

MicroRNA-mRNA functional pairs for cisplatin resistance in ovarian cancer cells

Ovarian cancer is the leading cause of death in women worldwide. Cisplatin is the core of first-line chemotherapy for patients with advanced ovarian cancer. Many patients eventually become resistant to cisplatin, diminishing its therapeutic effect. MicroRNAs （miRNAs） have critical functions in diverse biological processes. Using miRNA profiling and polymerase chain reaction validation, we identified a panel of differentially expressed miRNAs and their potential targets in cisplatin-resistant SKOV3/DDP ovarian cancer cells relative to cisplatin-sensitive SKOV3 parental cells. More specifically, our results revealed significant changes in the expression of 13 of 663 miRNAs analyzed, including 11 that were up-regulated and 2 that were down-regulated in SKOV3/DDP cells with or without cisplatin treatment compared with SKOV3 cells with or without cisplatin treatment. miRNA array and mRNA array data were further analyzed using Ingenuity Pathway Analysis software. Bioinformatics analysis suggests that the genes ANKRD17, SMC1A, SUMO1, GTF2H1, and TP73, which are involved in DNA damage signaling pathways, are potential targets of miRNAs in promoting cisplatin resistance. This study highlights candidate miRNA-mRNA interactions that may contribute to cisplatin resistance in ovarian cancer.     

Tripartite motif-containing 3 (TRIM3) inhibits tumor growth and metastasis of liver cancer

Background:Reduced expression of tripartite motif-containing 3 (TRIM3) has been reported to be involved in the pathogenesis of human glioblastoma.In our previous research,we found that TRIM3 expression was markedly reduced in human primary hepatocellular carcinoma (HCC) tissues and that low TRIM3 expression was associated with short survival of HCC patients.However,the role of TRIM3 in liver cancer remains unknown.This study aimed to investigate the function of TRIM3 in liver cancer cells.Methods:The protein levels of TRIM3 in five liver cancer cell lines (SK-Hep1,Hep3B,Huh7,HepG2,Bel-7402) and one normal liver cell line (L02) were detected with Western blotting.HepG2 and Bel-7402 cells with IowTRIM3 expression were infected with recombinant lentiviruses overexpressing TRIM3 (LV-TRIM3),whereas Huh7 and Hep3B cells with high TRIM3 expression were transfected with TRIM3-targeted small interfering RNA (siTRIM3).The functions of TRIM3 in the proliferation,colony formation,cell cycle,migration,invasion,and apoptosis of the above cell lines were examined.The effect of TRIM3 on tumor growth and metastases in nude mice was also investigated.Results:TRIM3 was overexpressed in HepG2 and Bel-7402 cells with LV-TRIM3 infection,which further reduced proliferation,colony formation,migration,and invasion of both cell lines.Cell cycle analysis showed thatTRIM3 overexpression induced G0/G1 phase arrest in HepG2 and Bel-7402 cells.Moreover,apoptosis was not increased in HepG2 or Bel-7402 cells overexpressing TRIM3.Contrarily,silencing TRIM3 expression in Huh7 and Hep3B cells by siTRIM3 led to significantly decreased percentages of both cells in the G0/G1 phase and promoted cell proliferation,colony formation,migration,and invasion.In vivo experiment results confirmed thatTRIM3 overexpression suppressed tumor growth and metastasis.Conclusions:TRIM3 plays a tumor-suppressing role in the regulation of liver cancer development by reducing cell proliferation through cell cycle arrest at the G0/G1 phase.