Hong-Chun Liu

FOXQ1 promotes esophageal cancer proliferation and metastasis by negatively modulating CDH1.

BACKGROUND Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with rapid progression, high recurrence and metastasis rate. Besides, the 5-year survival rate of ESCC remains dismal despite improvements in treatments having developed a lot. That is because the cellular basis of ESCC has not yet been fully understood. Forkhead box family membranes possess various kinds of properties as they mediate apoptosis, cell cycle arrest, autophagy, senescence and so on. Foxhead box Q1 (FOXQ1), which has a major impact on several kinds of tumor forming and metastasis, while whether it triggers ESCC remains largely obscure. METHODS To determine whether aberrant FOXQ1 expression in esophageal cancer, protein level and mRNA level of specimens of cancerous tissues and adjacent non-cancerous tissues were determined by western blot and real-time PCR. Then we overexpressed or knockdowned FOXQ1 in EC9706 cell; cell growth curve and colony formation were analyzed. Cell invasion ability was analyzed by migration chambers. Reporter gene assay was used to study the transcriptional regulation activity. RESULTS FOXQ1 was highly expressed in esophageal cancerous tissues compared with adjacent non-cancerous tissues. FOXQ1 overexpression promotes ESCC tumor cell proliferation, whereas FOXQ1 silencing prevents ESCC tumor cell proliferation. FOXQ1 promotes ESCC metastasis via negatively modulation CDH1. CDH1 silencing could rescue the migratory ability which was blemished by FOXQ1 silencing. FOXQ1 could act as transcriptional repressor which binds to the promoter of CDH1 and blocks its transcription. CONCLUSIONS In this study, we identified FOXQ1 as an oncogene to promote ESCC tumor cell proliferation and metastasis by negatively regulating CDH1 in EC9706 cell. Besides, we deciphered a previously unidentified mechanism of ESCC progression and metastasis.

Tamoxifen lowers the MMP-9/TIMP-1 ratio and inhibits the invasion capacity of ER-positive non-small cell lung cancer cells

Tamoxifen (TAM) serves for decades as a therapy drug for the prevention and treatment of breast cancers, especially effective for the estrogen receptor (ER)-positive ones. An increasing number of studies are trying to explore its potential application in treating other types of tumor including lung cancer. However, the effects of TAM on lung cancer cells, especially ER-positive ones, remain unclear. Thus, the present study was undertaken to assess the impact of TAM on the invasion capacity of an ER-positive human lung cancer cell model. In this study, the immunohistochemical staining was applied to verify the expression of estrogen receptors in SPC-A-1, a human lung adenocarcinoma cell line. The real-time PCR analysis was performed to test the expressions of MMP-9 and TIMP-1 in SPC-A-1 cells treated with different doses of TAM, while the invasion capacity was determined using transwell assays. In TAM-treated SPC-A-1 cells, which are ER-positive, an impaired ratio of MMP-9/TIMP-1 was observed as a net result of an increased transcriptional level of TIMP-1 as well as a reduced one of MMP-9. Furthermore, TAM suppressed the invasion of SPC-A-1 cells in vitro. Thus, we propose that TAM could work as an anti-metastasis drug inhibiting the invasion of human lung cancer cells.

Upregulation of the TPX2 gene is associated with enhanced tumor malignance of esophageal squamous cell carcinoma.

PURPOSE To explore the expression of TPX2 and its significance in esophageal squamous cell carcinoma (ESCC) tissue and approach relationship between the TPX2 and clinicopathological characteristic of esophageal squamous cell carcinoma. METHOD RT-PCR and immunohistochemical staining were used to compare the expression of TPX2 in 62 esophageal squamous cell carcinoma, 31 atypical hyperplasia and 62 normal esophageal mucosa. RESULTS In ESCC, atypical hyperplasia and in normal mucous membrane tissues, the positive rate of TPX2 protein expression was 85.5% (53/62), 51.6% (16/31) and 4.8% (3/62); the positive rate of TPX2 mRNA expression was 65.5% (40/62), 35.5 (11/31) and 4.83% (3/62). The expression of TPX2 protein and mRNA were correlated with invasive depth and lymphatic metastasis of ESCC (P<0.01). CONCLUSIONS Overexpression of TPX2 may be risk factor of lymph node in esophageal carcinoma, and maybe a potential biomarker for early diagnosis and prognosis of esophageal squamous cell carcinoma.

TPX2 siRNA regulates growth and invasion of esophageal cancer cells.

PURPOSE Observe how specific small RNA interference (siRNA) aimed at TPX2 gene suppresses TPX2 gene expression in esophageal cancer EC9706 cells and the effect on esophageal cancer cell growth and invasion ability. METHODS Transfect TPX2 siRNA into EC9706 cells via lipofectamin 2000. The experiments were divided into three groups, a negative control, a blank control and an siRNA interference group (24h, 48h, 72h, 96h). We examined RNA and protein level alteration of the TPX2 gene after TPX2 siRNA transfection by RT-PCR and Western blot analysis. Detection of how TPX2 siRNA influences EC9706 cell proliferation was done by MTT, cell apoptosis monitored through Tunel assay, in vitro invasion ability via Boyden chamber and cell cycle change by flow cytometry. RESULTS After effective siRNA transfection, TPX2 mRNA and protein expression level in siRNA interference group were (0.31±0.08, 0.39±0.12),72h after transfection, significantly lower than blank control group (1.00±0.01) and negative control group (0.98±0.11), (F=71.182, t1=8.17, t2=7.90, P<0.05); MTT results demonstrated that cell growth and proliferation were inhibited and the inhibition rate was up to 35.4% (P<0.05) compared with the control group. TUNEL results indicated that cell apoptosis index in siRNA interference group was 18.28±0.35, higher than that in blank control group (4.07±0.26)and negative control group (4.13±0.22), (F=244.5, t1=60.61, t2=53.32, P<0.01). Boyden chamber results showed that the transmembrane cell number was 45.30±8.08 in siRNA interference group, less than blank control group (121.90±7.83), (F=122.46, t1=11.81, t2=10.47, P<0.01); besides, in siRNA interference group cell invasion inhibition rate was 71.42±9.12, higher than negative control group (5.65±3.55), (t=14.256, P<0.01). Flow cytometry results illustrated that more EC9706 cells went into apoptosis and cell cycle arrested in S phase. Similar results were obtained by in vivo transplantation, as TPX2 siRNA transfection significantly reduced tumor growth of the xenograft in nude mice. CONCLUSION siRNA could effectively inhibit the invasion and metastasis of EC9706 cells, promote the apoptosis of tumor cells and may become a new approach for treatment of esophageal carcinoma.

Expression of VRK1 and the downstream gene BANF1 in esophageal cancer

Esophageal cancer is considered one of the most malignant tumors, being characterized by rapid progression and poor outcomes. China has the highest incidence of esophageal cancer in the world. Hence, it is necessary to clarify the mechanisms underlying esophageal cancer progression. In this study, we examined the expression of vaccinia-related kinase 1 (VRK1) and barrier to autointegration factor 1 (BANF1) in tumor tissues at the mRNA and protein levels via real-time PCR and immunohistochemical analyses. The mRNA and protein expression levels of VRK1 and BANF1 were higher in tumor tissues than in adjacent normal tissues. ROC curve analysis showed that VRK1 and BANF1 yielded AUCs of 0.790 and 0.735, respectively, for the detection of esophageal squamous cell carcinoma(ESCC) patients. In conclusion, our study indicates that VRK1 and BANF are promising novel therapeutic targets for esophageal cancer.

Hypoxia inducible factor-1α regulates autophagy via the p27-E2F1 signaling pathway

Autophagy is a highly conserved process by which the cell contents are delivered to lysosomes for degradation, or are used to provide macromolecules for energy generation under conditions of nutritional starvation. It has previously been demonstrated that cancer cells in hypoxic regions, with an oxygen concentration below the normal physiological level, express hypoxia inducible factor (HIF)-1α, in order to adapt and survive. HIF-1α is important in the regulation of oxygen homeostasis and the transcription of hundreds of genes in response to conditions of hypoxia, hence maintaining energy and redox homeostasis. To determine if HIF-1α modulates autophagy and the underlying molecular mechanisms regulating this process, the human esophageal cancer EC109 and IMR90 human diploid fibroblast cell lines were exposed to normoxic or hypoxic conditions and the expression levels of various proteins subsequently examined. Small interfering RNA was used to silence p27, in order to investigate its role in the process of HIF-1α regulated autophagy. Hypoxia induced autophagy in IMR90 cells and it was revealed that immature IMR90 cells demonstrated an increased rate of autophagy compared with mature cells. HIF-1α promoted EC109 cell autophagy via positively modulating p27, whereas silencing of p27 abolished the autophagy induced by hypoxia. The present study identified the primary components of the p27-E2F1 signaling pathway by which HIF-1α regulates autophagy. A previously unidentified mechanism is here presented, via which cancer cells may generate energy, or obtain macromolecules for survival.