Gene silencing of beta-catenin by RNAi inhibits cell proliferation in human esophageal cancer cells in vitro and in nude mice

Data-based modeling of breast cancer and optimal therapy

Excessive accumulation of β-catenin proteins is a vital driver in the development of breast cancer. Many clinical assessments incorporating immunotherapy with targeted mRNA of β-catenin are costly endeavor. This paper develops novel mathematical models for different treatments by invoking available clinical data to calibrate models, along with the selection and evaluation of therapy strategies in a faster manner with lower cost. Firstly, in order to explore the interactions between cancer cells and the immune system within the tumor microenvironment, we construct different types of breast cancer treatment models based on RNA interference technique and immune checkpoint inhibitors, which have been proved to be an effective combined therapy in pre-clinical trials associated with the inhibition of β-catenin proteins to enhance intrinsic anti-tumor immune response. Secondly, various techniques including MCMC are adopted to estimate multiple parameters and thus simulations in agreement with experimental results sustain the validity of our models. Furthermore, the gradient descent method and particle swarm algorithm are designed to optimize therapy schemes to inhibit the growth of tumor and lower the treatment cost. Considering the mechanisms of drug resistance in vivo, simulations exhibit that therapies are ineffective resulting in cancer relapse in the prolonged time. For this reason, parametric sensitivity analysis sheds light on the choice of new treatments which indicate that, in addition to inhibiting β-catenin proteins and improving self-immunity, the injection of dendritic cells promoting immunity may provide a novel vision for the future of cancer treatment. Overall, our study provides witness of principle from a mathematical perspective to guide clinical trials and the selection of treatment regimens.

RNAi-mediated TCF-3 gene silencing inhibits proliferation of Eca-109 esophageal cancer cells by inducing apoptosis

Esophageal cancer (EC) remains an important health problem in China. In the present study, through the use of siRNA, specific gene knockdown of transcription factor 3 gene (TCF-3) was achieved in vitro and the effect of TCF-3 gene on human EC Eca-109 cell proliferation and apoptosis. Eca-109 cells were treated using negative control (NC) of siRNA against TCF-3 (siTCF-3) and siTCF-3 group. Colony formation assay was used to detect the colony formation ability in Eca-109 cells. MTT assay was used to measure the cell growth and viability, whereas BrDU assay was used to evaluate cell proliferation, and flow cytometry (FCM) to assess cell apoptosis. Reverse-transcription quantitative PCR (RT-qPCR) was applied to measure TCF-3 gene expression. Protein expressions of TCF-3, apoptosis-related proteins, Bcl-2, Bax, and caspase-3 were determined using Western blotting. Transfection of siTCF-3 successfully down-regulated TCF-3 gene expression. In addition, siTCF-3, reduced Eca-109 cell viability and proliferation, in a time-dependent manner, and inhibited progression of cell cycle from G₀/G₁ to S-stage. When treated with siTCF-3, the Eca-109 cells exhibited increased apoptosis, with up-regulated cleaved caspase and Bax expressions, whereas Bcl-2 expression was down-regulated. The present study shows that TCF-3 gene silencing inhibits Eca-109 cell growth and proliferation, suppresses cell cycle progression, and promotes apoptosis, which might serve as a new objective for EC treatment.

β-catenin knockdown enhances the effects of fluorouracil in the breast cancer cell line MDA-MB-468

Tumor proliferation, drug resistance and cell stemness are major difficulties that are encountered during breast cancer therapy and are often responsible for disease progression and cancer-related mortality. β-catenin is considered to be an invasion gene in breast cancer. However, how β-catenin regulates breast cancer cell proliferation and stemness remains unclear. In the present study, β-catenin knockdown by small interfering RNA in MDA-MB-468, a highly metastatic breast cancer cell line, inhibited the expression of β-catenin, Oct3/4 (stemness), survivin (anti-apoptosis) and BCRP (drug resistance). Knockdown of β-catenin enhanced the effects of fluorouracil (5-FU) chemotherapy on the proliferation of MDA-MB-468 cells. Thus, these preliminary results indicate that β-catenin knockdown enhanced 5-FU-induced proliferation inhibition in the breast cancer cell line MDA-MB-468, and indicate that combining 5-FU with gene silencing could be an advantageous option for enhancing the curative effect of chemotherapy in breast cancer and other malignancies.

Activated macrophages promote Wnt/β-catenin signaling in cholangiocarcinoma cells

The Wnt/β-catenin signaling pathway is pathologically activated in cholangiocarcinoma (CCA). Here, we determined the expression profile as well as biological role of activated Wnt/β-catenin signaling in CCA. The quantitative reverse transcription polymerase chain reaction demonstrated that Wnt3a, Wnt5a, and Wnt7b mRNA were significantly higher in CCA tissues than adjacent non-tumor tissues and normal liver tissues. Immunohistochemical staining revealed that Wnt3a, Wnt5a, and Wnt7b were positive in 92.1, 76.3, and 100 % of 38 CCA tissues studied. It was noted that Wnt3 had a low expression in tumor cells, whereas a high expression was mainly found in inflammatory cells. Interestingly, a high expression level of Wnt5a was significantly correlated to poor survival of CCA patients (P=0.009). Membrane localization of β-catenin was reduced in the tumors compared to normal bile duct epithelia, and we also found that 73.7 % of CCA cases showed the cytoplasmic localization. Inflammation is known to be a risk factor for CCA development, and we tested whether this might induce Wnt/β-catenin signaling. We found that lipopolysaccharides (LPS) elevated the expression of Wnt3 both mRNA and protein levels in the macrophage cell line. Additionally, the conditioned media taken from LPS-induced activated macrophage culture promoted β-catenin accumulation in CCA cells. Furthermore, transient suppression of β-catenin by siRNA significantly induced growth inhibition of CCA cells, concurrently with decreasing cyclin D1 protein level. In conclusion, the present study reports the abundant expression of Wnt protein family and β-catenin in CCA as well as the effect of inflammatory condition on Wnt/β-catenin activation in CCA cells. Importantly, abrogation of β-catenin expression caused significant CCA cell growth inhibition. Thus, the Wnt/β-catenin signaling pathway may contribute to CCA cell proliferation and hence may serve as a prognostic marker for CCA progression and provide a potential target for CCA therapy.

Gene silencing of β-catenin by RNAi inhibits proliferation of human esophageal cancer cells by inducing G0/G1 cell cycle arrest

OBJECTIVES

The aim of the present study was to explore mechanisms underlying the effects of down-regulating β-catenin expression on esophageal carcinoma (EC) cells.

METHODS

Cell cycle distribution and apoptosis were determined using flow cytometry and annexin V apoptosis assay, respectively. Transmission electron microscopy (TEM) was used to examine changes in ultrastructure, while expression of cyclin D1 protein and mRNA was detected by western blot and real-time PCR. Proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) 1/2 were evaluated by Western blot analysis. PCNA labeling index (LI) was determined by immunocytochemistry.

RESULTS

Compared with pGen-3-con transfected and Eca-109 cells, the percentage of G0/G1-phase pGen-3-CTNNB1 transfected cells was obviously increased (P<0.05), with no significant difference among the three groups with regard to apoptosis (P>0.05). pGen-3-CTNNB1 transfected cells exhibited obvious decrease in cyclin D1 mRNA and protein expression (P<0.05) and the ultrastructure of Eca-109 cells underwent a significant change after being transfected with pGen-3-CTNNB1, suggesting that down-regulating β-catenin expression can promote the differentiation and maturation. The expression of PCNA and the ERKI/2 phosphorylation state were also down-regulated in pGen-3-CTNNB1 transfected cells (P<0.05). At the same time, the PCNA labeling index was decreased accordingly (P<0.05).

CONCLUSION

Inhibition of EC Eca-109 cellproliferation by down-regulating β-catenin expression could improve cell ultrastructure by mediating blockade in G0/G1 through inhibiting cyclin D1, PCNA and the MAPK pathway (p-ERK1/2).

Lentivirus-mediated gene silencing of beta-catenin inhibits growth of human tongue cancer cells

BACKGROUND

Beta-catenin is one of the key components of Wnt signaling pathway. Increased level of this protein has been proved to be associated with enhanced cellular proliferation and the development of many kinds of cancers. But its role in the carcinogenesis in human tongue squamous cell carcinoma, one of the most common carcinomas of the human oral cavity, remains poorly characterized.

METHODS

In this study, we used lentivirus-mediated RNA interference (RNAi) targeted against beta-catenin to determine the effects of decreasing the high constitutive level of this protein in human tongue carcinoma cell line Tca8113.

RESULTS

Our studies demonstrated that RNAi directly against beta-catenin markedly decreased beta-catenin gene expression and inhibited cellular proliferation as reflected in the reduced growth of tongue cancer cells both in vitro and in nude mice.

CONCLUSIONS

RNA interference (RNAi) targeting against beta-catenin can induce cell growth suppression of tongue cancer and may have the potential as a therapeutic modality to treat human tongue cancer.

Potential use of RNA interference in cancer therapy

RNA interference (RNAi) is an evolutionary conserved mechanism for specific gene silencing. This mechanism has great potential for use in targeted cancer therapy. Understanding the RNAi mechanism has led to the development of several novel RNAi-based therapeutic approaches currently in the early phases of clinical trials. It remains difficult to effectively deliver the nucleic acids required in vivo to initiate RNAi, and intense effort is under way in developing effective and targeted systemic delivery systems for RNAi. Description of in vivo delivery systems is not the focus of this review. In this review, we cover the rationale for pursuing personalised cancer therapy with RNAi, briefly review the mechanism of each major RNAi therapeutic technique, summarise and sample recent results with animal models applying RNAi for cancer, and provide an update on current clinical trials with RNAi-based therapeutic agents for cancer therapy. RNAi-based cancer therapy is still in its infancy, and there are numerous obstacles and issues that need to be resolved before its application in personalised therapy focusing on patient-cancer-specific targets can become standard cancer treatment, either alone or in combination with other treatments.

Short hairpin RNA targeting beta-catenin suppresses cell proliferation and induces apoptosis in human gastric carcinoma cells

OBJECTIVE

Aberrant activation of Wnt/beta-catenin signaling is involved in various cancers, including human gastric cancer. Here we investigate the role of Wnt/beta-catenin signaling in regulating gastric cancer cell apoptosis.

MATERIAL AND METHODS

Expression of beta-catenin was investigated after transfection with beta-catenin short hairpin RNA (shRNA) in gastric cancer cells by Western blotting and immunofluorescence analysis. beta-catenin/T-cell factor transcriptional activity was also investigated by using a luciferase reporter assay. Next, the effects of beta-catenin shRNA on cell proliferation and apoptosis were evaluated by the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide assay and flow cytometric analysis. To investigate the precise mechanism of these effects, a comprehensive analysis was performed using a cDNA microarray.

RESULTS

shRNA targeting beta-catenin resulted in a significant decrease in beta-catenin expression, and its nuclear localization and cell proliferation. Meanwhile, increased cell apoptosis was confirmed. The comprehensive analysis showed that shRNA targeting beta-catenin upregulated 26 apoptosis-related genes (including PERP, TRAF3, PDCD2, TNFRSF25, AKT2 and YWHAZ) and downregulated 48 apoptosis-related genes (including MALT1, IRAK1, TNFAIP3, PPP1R13L, TRIP and YWHAB) in gastric cancer cells. Pathway analysis suggested that the nuclear factor-kappaB pathway was involved in beta-catenin knockdown-induced apoptosis.

CONCLUSIONS

Attenuation of beta-catenin by shRNA resulted in suppressed cell proliferation and apparent apoptosis, suggesting that beta-catenin may be a target for therapy of gastric cancer.

Comparative proteomic analysis of beta-catenin-mediated malignant progression of esophageal squamous cell carcinoma

beta-catenin has emerged as a key regulator of Wnt signaling pathway, which plays an important role in the development and progression of various cancers. Its accumulation in nucleus of the esophagus squamous epithelium might be the crucial step for the carcinogenesis of esophageal squamous cell carcinoma (ESCC). To detect the proteins correlated with beta-catenin function, we used the established cell lines of pGen-3-con (Eca109 cells transfected by control vector) and pGen-3-CTNNB1 (Eca109 cells transfected by beta-catenin siRNA) as cell models for further analysis. Two-dimensional gel electrophoresis technology was performed to separate the proteins of pGen-3-con and pGen-3-CTNNB1 cell lines, respectively. The differential protein spots were analyzed by software analysis, subjected to in-gel digestion, and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Consequently, 13 differentially expressed proteins between the two cell lines were identified, of which 14-3-3sigma, prohibitin, and nm23-H1 were further verified by western blotting and quantitative real-time reverse transcriptase-polymerase chain reaction. Then, the tissue microarray and immunohistochemical analysis were employed to research their relationship in ESCC and their corresponding normal mucosa tissues. The upregulation of prohibitin or the downregulation of 14-3-3sigma and nm23-H1 proteins was significantly associated with the proliferation, invasion depth, and lymph node metastasis of ESCC. There were statistically significant correlations between the expression of beta-catenin and the three proteins. The results presented here might provide potential protein markers to elucidate the mechanism of beta-catenin-mediated biologic characteristics for ESCC.