Deyun Feng

Therapeutic Evaluation of Epstein-Barr Virus-encoded Latent Membrane Protein-1 Targeted DNAzyme for Treating of Nasopharyngeal Carcinomas

The ability of the 10–23 DNAzyme to specifically cleave RNA with high efficiency has fuelled expectation that this agent may have useful applications for targeted therapy. Here, we, for the first time, investigated the antitumor and radiosensitizing effects of a DNAzyme (DZ1) targeted to the Epstein-Barr virus (EBV)-LMP1 mRNA of nasopharyngeal carcinoma (NPC) in patients. Preclinical studies indicated that the DNAzyme was safe and well tolerated. A randomized and double-blind clinical study was conducted in 40 NPC patients who received DZ1 or saline intratumorally, in conjunction with radiation therapy. Tumor regression, patient survival, EBV DNA copy number and tumor microvascular permeability were assessed in a 3-month follow-up. The mean tumor regression rate at week 12 was significantly higher in DZ1 treated group than in the saline control group. Molecular imaging analysis showed that DZ1 impacted on tumor microvascular permeability as evidenced by a faster decline of the Ktrans in DZ1-treated patients. The percentage of the samples with undetectable level of EBV DNA copy in the DZ1 group was significantly higher than that in the control group. No adverse events that could be attributed to the DZ1 injection were observed in patients.

FOXC2 promotes chemoresistance in nasopharyngeal carcinomas via induction of epithelial mesenchymal transition

Paclitaxel (Taxol) is currently used as the front-line chemotherapeutic drug for many types of human cancers. However, the emergence of drug resistance has been a major obstacle to the effective treatment of cancers in clinical settings. The transcription factor Forkhead box protein C2 (FOXC2) was recently demonstrated to activate the epithelial-mesenchymal transition (EMT). In this article, we present a novel role of FOXC2 in regulating chemoresistance of nasopharyngeal carcinoma (NPC) through the EMT. Using an EMT PCR array based on the screening of 84 genes, the expression of FOXC2 was notably upregulated in paclitaxel-resistant NPC cells (CNE2/t). We observed that the paclitaxel-resistant cells exhibited characteristic EMT phenotypes. The silencing of FOXC2 expression in the resistant cells can reverse the EMT molecular markers and chemoresistant phenotypes, such as cellular morphology, proliferation and anoikis. In an NPC xenograft mouse model, the downregulation of FOXC2 expression in the resistant NPC cells increased their sensitivity to paclitaxel treatment, resulting in reduced tumor growth. Taken together, our results suggest that FOXC2-mediated EMT may be an alternative mechanism through which cancer cells can initiate and maintain drug resistance. Thus, targeting FOXC2 may provide a novel strategy for overcoming chemoresistance in NPC therapy.

HSP70 and mucin 5B: novel protein targets of N,N′‐dinitrosopiperazine‐induced nasopharyngeal tumorigenesis

N,N′‐Dinitrosopiperazine (DNP) induces nasopharyngeal carcinoma (NPC) and shows organ specificity to the nasopharyneal epithelium. To investigate its mechanism, the rat NPC model was inducd using DNP. Rat NPC and normal nasopharyngeal cells were obtained from the NPC model using laser capture. The total proteins from these cell samples were separated with two‐dimension polyacrylamide gel electrophoresis techniques, and highly expressed proteins (> five‐fold) were analyzed using matrix‐assisted laser desorption/ionization time of flight and bioinformatics. The results showed that HSP70 and mucin 5B expression increased not only in rat NPC but also in atypical hyperplasia nasopharyngeal tissues, a precancer stage of NPC. High‐expression of heat shock protein 70 (HSP70) and mucin 5B was further supported by western blot analysis. The immunofluorescence and western‐blotting studies further showed that DNP induced the expression of HSP70 and mucin 5B in a dosage‐dependent manner in normal nasopharyngeal epithelia cells. Our data indicate that DNP triggers over‐expression of HSP70 and mucin 5B, and is involved in nasopharyngeal tumorigenesis. HSP70 and mucin 5B may be important targets in nasopharyngeal tumorigenesis induced by DNP. (Cancer Sci 2009; 100: 216–224)

Detection of STAT2 in early stage of cervical premalignancy and in cervical cancer

OBJECTIVE To measure the expression pattern of STAT2 in cervical cancer initiation and progression in tissue sections from patients with cervicitis, dysplasia, and cervical cancer. METHODS Antibody against human STAT2 was confirmed by plasmids transient transfection and Western blot. Immunohistochemistry was used to detect STAT2 expression in the cervical biopsies by using the confirmed antibody against STAT2 as the primary antibody. RESULTS It was found that the overall rate of positive STAT2 expression in the cervicitis, dysplasia and cervical cancer groups were 38.5%, 69.4% and 76.9%, respectively. The STAT2 levels are significantly increased in premalignant dysplasia and cervical cancer, as compared to cervicitis (P< 0.05). Noticeably, STAT2 signals were mainly found in the cytoplasm, implying that STAT2 was not biologically active. CONCLUSIONS These findings reveal an association between cervical cancer progression and augmented STAT2 expression. In conclusion, STAT2 increase appears to be an early detectable cellular event in cervical cancer development.

Positive regulation of TAZ expression by EBV-LMP1 contributes to cell proliferation and epithelial-mesenchymal transition in nasopharyngeal carcinoma

The Epstein-Barr virus latent membrane protein 1 (LMP1) is an integral membrane protein. LMP1 has been reported to activate the NF-κB and mitogen-activated protein kinase pathways. However, these effects alone are unable to account for the profound oncogenic properties of LMP1. TAZ is one of the nuclear effectors of Hippo-related pathways and highly expressed in many human tumors. Here, we reported that TAZ was frequently expressed in LMP1-positive nasopharyngeal carcinoma. In NPC cell lines, we showed that LMP1 promoted TAZ expression. Gelsolin is an important inhibitor of TAZ activity. Our studies showed that LMP1 interacted with gelsolin, resulting in inhibition of Lats1/2 phosphorylation and improvement of TAZ stability. Furthermore, we revealed that TAZ is important for LMP1-mediated cell proliferation, cancer stem cell-like properties and epithelial-mesenchymal transition. These findings provide new insights into the carcinogenic roles of LMP1 and contribute to further understanding of its oncogenic mechanism.The Epstein-Barr virus latent membrane protein 1 (LMP1) is an integral membrane protein. LMP1 has been reported to activate the NF-κB and mitogen-activated protein kinase pathways. However, these effects alone are unable to account for the profound oncogenic properties of LMP1. TAZ is one of the nuclear effectors of Hippo-related pathways and highly expressed in many human tumors. Here, we reported that TAZ was frequently expressed in LMP1-positive nasopharyngeal carcinoma. In NPC cell lines, we showed that LMP1 promoted TAZ expression. Gelsolin is an important inhibitor of TAZ activity. Our studies showed that LMP1 interacted with gelsolin, resulting in inhibition of Lats1/2 phosphorylation and improvement of TAZ stability. Furthermore, we revealed that TAZ is important for LMP1-mediated cell proliferation, cancer stem cell-like properties and epithelial-mesenchymal transition. These findings provide new insights into the carcinogenic roles of LMP1 and contribute to further understanding of its oncogenic mechanism.

Overexpression of ANLN contributed to poor prognosis of anthracycline-based chemotherapy in breast cancer patients

PurposeTo investigate the associations of ANLN expression with prognosis of breast cancer and clinical outcome of anthracycline-based chemotherapy.MethodsThis study enrolled 308 breast cancer patients in which 264 of them received anthracycline-based chemotherapy. Immunohistochemistry was used to detect ANLN expression level of the patients. Clinical characteristics of the patients were collected, and associations of ANLN expression with prognosis were analyzed.ResultsOur results showed that ANLN expression was associated with survival of breast cancer patients, and it was also related to clinical outcome of patients received anthracycline-based chemotherapy. Breast cancer patients with high expression of ANLN would have poor prognosis and poor clinical outcome to anthracycline-based chemotherapy.ConclusionANLN could be an independent prognosis predictor for breast cancer, and its expression might be used to predict the anthracycline-based chemotherapy clinical outcome in breast cancer patients.

Preoperative prediction of microvascular invasion of hepatocellular carcinoma with IVIM diffusion-weighted MR imaging and Gd-EOB-DTPA-enhanced MR imaging

Microvascular invasion (MVI) is regarded as one of the independent risk factors for recurrence and poor prognosis of hepatocellular carcinoma (HCC). The presence of MVI in HCCs was evaluated on the basis of pathological reports of surgical specimens and was defined as tumor within a vascular space lined by endothelium that was visible only on microscopy. The aim of the study was to investigate the usefulness of intravoxel incoherent motion (IVIM) diffusion weighted (DW) magnetic resonance (MR) imaging in predicting MVI of HCC. Preoperative IVIM DW imaging and Gd-EOB-DTPA-enhanced MRI (DCE-MRI) of 51 patients were analyzed. Standard apparent diffusion coefficient (ADC), D (the true diffusion coefficient), D* (the pseudodiffusion coefficient) and f (the perfusion fraction), relative enhancement (RE) and radiological features were evaluated and analyzed. Univariate analysis revealed that HCCs with MVI had a higher portion of an irregular tumor shape than HCCs without MVI (p = 0.009), the Standard ADC, D value were significantly lower in HCCs with MVI (p = 0.022, p = 0.007, respectively). Multivariate analysis revealed that an irregular shape (p = 0.012) and D value ≤ 1.16×10-3mm2/sec (p = 0.048) were independent predictors for MVI. Combining the two factors of an irregular shape and D value, a sensitivity of 94.4% and specificity of 63.6% for predicting MVI was obtained. In conclusion, we found that an irregular shape and D value ≤ 1.16×10-3mm2/sec may suggest the presence of MVI in HCCs.