Jinyue Hu

The Expression of Functional Chemokine Receptor CXCR4 Is Associated with the Metastatic Potential of Human Nasopharyngeal Carcinoma

Purpose: Chemokine receptors are implicated in metastasis of several malignant tumors. This study was done to evaluate the contribution of chemokine receptors CXCR4 and CCR7 to metastasis of human nasopharyngeal carcinoma. Experimental Design: Reverse transcription-PCR, immunohistochemistry, and flow cytometry were used to evaluate mRNA and protein expression of CXCR4 and CCR7 in nasopharyngeal carcinoma tumor tissues and cell lines. Chemotaxis assays were used to evaluate the function of CXCR4 in nasopharyngeal carcinoma cells. Antisense CXCR4 was used to inhibit receptor expression and to block metastasis of human nasopharyngeal carcinoma cells in vivo in athymic mice. Results: CXCR4 protein was detected in tumor cells in 31 of 40 primary human nasopharyngeal carcinoma and in 13 of 15 lymph node metastases. CXCR4 transcripts were detected in eight CXCR4 protein–positive primary nasopharyngeal carcinoma tissues and seven nasopharyngeal carcinoma cell lines tested. On the other hand, the transcripts for CCR7 were detected only in four primary nasopharyngeal carcinoma tissues and in none of the nasopharyngeal carcinoma cell lines. In functional experiments, metastatic nasopharyngeal carcinoma cell lines that expressed high levels of CXCR4 were found to migrate in response to the CXCR4 ligand SDF-1α. Transfection of antisense CXCR4 in metastatic nasopharyngeal carcinoma cells inhibited the expression of CXCR4 and SDF-1α-induced cell migration in vitro and reduced the capacity of the tumor cells to form metastasis in the lungs and lymph nodes when injected in athymic mice. Conclusion: The expression of functional CXCR4 but not CCR7 is correlated with the metastatic potential of human nasopharyngeal carcinoma cells. Therefore, CXCR4 may be considered as a potential target for the prevention of nasopharyngeal carcinoma metastasis.

TLR3 activation inhibits nasopharyngeal carcinoma metastasis via downregulation of chemokine receptor CXCR4.

Toll-like receptor 3 (TLR3), a receptor for viral double strain RNA (dsRNA), mediates anti-viral immune response by activating the innate immunity and cross-priming CD8+ T cells. TLR3 agonists can directly trigger apoptosis in human cancer cells, and have been used as adjuvants to treat cancer patients with the aim of inducing an IFN-dependent immune response. In this study, we examined the effect of TLR3 activation on the metastasis of nasopharyngeal carcinoma (NPC). We found that NPC cells expressed TLR3 gene transcript and protein. TLR3 activation down-regulated the expression of chemokine receptor CXCR4 in a dose-dependent manner, and inhibited cell migration in response to CXCR4 ligand stromal cell-derived factor-1α (SDF-1α) in chemotaxis assays. Furthermore, TLR3 activation significantly reduced the capacity of NPC cells to form metastasis in draining lymph nodes when injected in athymic mice. The anti-metastasis activity of endogenous human TLR3 expression in cancer cells reveals a novel aspect of the multiple-faced TLR biology, which may open new clinical prospects for using TLR3 agonists to control cancer metastasis in selected cancers.

Identification of genes associated with tumor development in CaSki cells in the cosmic space

It is important to understand the mechanisms of tumor development for curing cervical cancer. However, the molecular basis determining the different characteristics of tumor remains unclear. Space environment as a special study model can expand the study field of tumor development. To approach this, after human cervical carcinoma CaSki cells were flown on “Shen Zhou IV” space shuttle mission, the cell morphology and proliferation was investigated after flying to ground. We found that the growth of 48A9 CaSki cell (flight group) became slow compared with ground groups. Observation of cells by light microscopy revealed differences in cell morphology between ground controls and flight groups, and the flight group exhibited morphologic differences, characterized by rounder, smoother, decreased, smaller and low-adhension cells. Transmission electron microscope images showed the structure of the ultrastructural characteristics of 48A9 CaSki cells were clearly distinct from those of the ground CaSki cells in aspects of mitochondrion, cytoplasm, nucleus and ribosomes. MTT and soft agar assay showed that 48A9 CaSki cells grew slowly compared to ground control. Furthermore, suppression subtractive hybridization combining with reverse Northern blot was used to identify differently expression genes between flight and ground groups. These differentially expressed genes included cytoskeleton, cell differentiation, cell apoptosis, signal transduction, DNA repair, protein synthesis, substance metabolism, and antigen presentation. The identification of differently expressed genes which is likely to increase our understanding of the molecular processes underlying tumor development will provide new insight into tumor development mechanisms, and may facilitate the development of new anticancer strategies.

Gammaaminobutyric Acid A Receptor Alpha 3 Subunit is Overexpressed in Lung Cancer

The identification of tumor-associated antigens, which are specifically expressed in cancer tissues, is very important for immunotherapy of lung cancer. We have combined the in silico screening and experimental verifying to identify genes that are differently expressed in cancers compared with their corresponding normal tissues. Using these methods, we have identified that GABRA3 gene was overexpressed in lung cancer and rarely expressed in other cancers. Furthermore, GABRA3 protein expression was significantly higher in the lower grade of lung cancer. It may compose functional GABA-gated channel with other subunits. This study demonstrated GABRA3 could be a potential biomarker for diagnosis of lung cancer, and GABAA receptors may play an important role in cancer differentiation.

BMI-1 autoantibody in serum as a new potential biomarker of nasopharyngeal carcinoma.

BMI-1 is overexpressed in a variety of cancers, which can activate the immune system to produce antibodies in tumor tissues. In this study, we isolated phage expressing BMI-1 protein by screening of a mixture of nasopharyngeal carcinoma (NPC) cDNA T7 phage library and found that the antibody against BMI-1 was elevated in the sera from NPC patients. BMI-1 mRNA was over-expressed at different levels in seven NPC cell lines compared with normal nasopharyngeal epithelial cell line NP69. Histochemistry showed that patient sera were more reactive with BMI-1 than normal sera. Antibody affinity assay using sera from 40 NPC patients and 54 controls showed that BMI-1 antibody was significantly greater in patient sera than in normal controls (patient 0.791 ± 0.025 and normal 0.488 ± 0.042; P < 0.001) and the BMI-1 autoantibody be significantly related with the progress of NPC (Benign versus LNPC P=0.001; LNPC versus MNPC P=0.047). Analysis of the results with logistic regression and receiver operating characteristics (ROC) curves showed that BMI-1 antibody was a modest marker for NPC (sensitivity 0.74 and specificity 0.73; AUC = 0.8044). The showed that BMI-1 antibody as a potential marker of NPC may be rational, and could have diagnostic and prognostic value.

Spaceflight alters the gene expression profile of cervical cancer cells.

Our previous study revealed that spaceflight induced biological changes in human cervical carcinoma Caski cells. Here, we report that 48A9 cells, which were subcloned from Caski cells, experienced significant growth suppression and exhibited low tumorigenic ability after spaceflight. To further understand the potential mechanism at the transcriptional level, we compared gene expression between 48A9 cells and ground control Caski cells with suppression subtractive hybridization (SSH) and reverse Northern blotting methods, and analyzed the relative gene network and molecular functions with the Ingenuity Pathways Analysis (IPA) program. We found 5 genes, SUB1, SGEF, MALAT-1, MYL6, and MT-CO2, to be up-regulated and identified 3 new cDNAs, termed B4, B5, and C4, in 48A9 cells. In addition, we also identified the two most significant gene networks to indicate the function of these genes using the IPA program. To our knowledge, our results show for the first time that spaceflight can reduce the growth of tumor cells, and we also provide a new model for oncogenesis study.

Identification of HTA as a novel-specific marker for human hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is the most common malignancy in the world, especially in China. Early diagnosis of new and recurrent hepatocellular carcinoma, followed by timely treatment, will help decrease mortality. Currently biomarkers are not satisfactory. Better diagnostic methods are highly demanded.MethodsIn this study, we have used in silico identification and RT-PCR test and discovered a hepatoma associated gene (HTA). Knockdown of endogenous HTA expression was performed by small interfering RNA in malignant hepatocyte HepG2. Then we tested the cell proliferative ability of these cells in vitro and in vivo.ResultsHTA was expressed specifically in some kinds of tumors, but not detected in any normal tissues. It was expressed especially high in hepatocellular carcinoma. Knockdown of endogenous HTA expression in HepG2 by small interfering RNA attenuated HCC cell growth.ConclusionsHCA is a very good marker for tumors, especially for HCC. It could play important roles in HCC development and progression and can be a promising molecular target for the development of new diagnostic and therapeutic strategies for HCC.

Immunogenicity and efficacy of a DNA vaccine encoding a human anti-idiotype single chain antibody against nasopharyngeal carcinoma.

G22, an anti-idiotype single chain antibody screened from human nasopharyngeal carcinoma phage anti-idiotype antibody library, has been already identified by He et al. G22 DNA vaccine was produced by cloning G22 gene and inserting the cloned gene into pcDNA3.1. To investigate the immunogenicity of pcDNA3.1-G22, C57BL/6 mice were immunized with the vaccine, pcDNA3.1 and PBS individually and the antibody response, T cell phenocyte at the 15th, 22th, 29th, 36th day after the last immunity were detected. In the tumor protection experiment, the immunized mice were then challenged with CMT-93-G22 cells or CMT-93-mock cells. The tumor size and the survival time of the animals were compared between these groups. The results showed that DNA vaccine pcDNA3.1-G22 could raise G22-specific humoral and cellular immune responses. Furthermore, pcDNA3.1-G22 could prolong the survival time and lessen the tumor size of the CMT-93-G22-bearing mice but had no protection effect on the mice attacked by CMT-93-mock cells. These results were expected to lay foundation for further studies on the clinical application of pcDNA3.1-G22 DNA vaccine.