Qing Zhu

Overexpression of YAP and TAZ is an independent predictor of prognosis in colorectal cancer and related to the proliferation and metastasis of colon cancer cells.

Background and Objective Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) are nuclear effectors of the Hippo pathway. Although they are abundantly expressed in the cytoplasm and nuclei of human colorectal cancer (CRC), and related to tumor proliferation status, there have been few studies on the predictive role of YAP and TAZ expression on the overall survival of patients with CRC. This study investigated YAP and TAZ expression in both CRC patients and colon cancer cell lines, and assessed their prognostic value. Methods Paraffin-embedded specimens from 168 eligible patients were used to investigate YAP and TAZ expression by immunohistochemistry, and compared with experimental results in colon cancer HCT116 cell line to explore their clinical significance in CRC. Results Statistically significant positive correlations were found between protein expression of YAP and TAZ in CRC tissues. Patients with higher YAP or TAZ expression showed a trend of shorter survival times; more importantly, our cohort study indicated that patients with both YAP and TAZ overexpression presented the worst outcomes. This was supported by multivariate analysis. In HCT116 colon cancer cells, the capacity for proliferation, metastasis, and invasion was dramatically reduced by knockdown of YAP and TAZ expressions by siRNA. Conclusions Co-overexpression of YAP and TAZ is an independent predictor of prognosis for patients with CRC, and may account for the higher proliferation, metastasis, and poor survival outcome of these patients.

Expression and Clinical Significance of YAP, TAZ, and AREG in Hepatocellular Carcinoma

Purpose. Yes-associated protein (YAP) and PDZ-binding motif (TAZ) are two important effectors of Hippo pathway controlling the balance of organ size and carcinogenesis. Amphiregulin (AREG) is a member of the epidermal growth factor family, a direct target gene of YAP and TAZ. The role of these proteins in hepatocellular carcinoma (HCC) is unclear. Methods. The expression of YAP, TAZ, and AREG in HCC was analyzed by immunohistochemical staining. The level of secreted serum AREG was also assayed by enzyme-linked immunosorbent (ELISA) assay. Results. YAP, TAZ, and AREG were expressed in 69.2% (27/39), 66.7% (26/39), and 61.5% (24/39) of HCC patients. The expression of YAP was significantly correlated with Edmondson stage (P > 0.05), serum AFP level (P > 0.05), and HCC prognosis (P > 0.05). AREG expression was also significantly correlated with Edmondson stage (P > 0.05) and serum AFP level (P > 0.05). In addition, the expression of serum AREG was higher than serum AFP in HCC patients. Further multivariate analysis showed that YAP expression was an independent prognostic factor that significantly affected the overall survival of HCC patients. Conclusions. YAP maybe an independent prognostic indicator for HCC patients and serum AREG may be a serological biomarker of HCC.

Serum SALL4 Is a Novel Prognosis Biomarker with Tumor Recurrence and Poor Survival of Patients in Hepatocellular Carcinoma

Aim. Sal-like protein 4 (SALL4), is reexpressed in tissues of a subgroup of HCC associated with poor prognosis. Reports of SALL4 serological levels linked to HCC patients are meager and unclear in the prognosis of this malignancy. Methods. Immunohistochemistry and optical microscopy protocols were used to examine the presence of SALL4 in liver tissues from the following patients: 38 HCC, 11 chronic hepatitis B virus (HBV), 13 liver cirrhosis, and 12 healthy controls. Additionally, enzyme-linked immunosorbent assay (ELISA) was used to measure the SALL4 levels in serum samples isolated from patients as follows: 127 with HCC, 27 with HBV, 24 with liver cirrhosis, and 23 normal controls. Results. Analysis of liver tissues sections from HCC patients (18 out 38; 47.4%) showed positive staining for SALL4 and its expression did no correlate with any of the clinicopathologic characteristics. HCC patients displayed higher levels (50.4%) of SALL4 protein in serum, compared with the three control groups. Moreover, SALL4 concentration reached the maximum level after one week after treatment and dropped quickly after one month. These HCC patients showing high SALL4 serum levels had poor prognosis, evidenced by both tumor recurrence and overall survival rate. Conclusions. High SALL4 serum levels are a novel biomarker in the prognosis of HCC patients.

Autoantibodies against insulin-like growth factor-binding protein-2 as a serological biomarker in the diagnosis of lung cancer

Insulin-like growth factor-binding protein-2 (IGFBP-2) is considered to be a human tumor antigen, and the tumor-specific immunity of IGFBP-2 has been reported in several types of cancer. The purpose of this study was to evaluate whether autoantibodies to IGFBP-2 can be used as diagnostic markers in lung cancer. The results demonstrated that serum anti-IGFBP-2 autoantibody levels were significantly elevated in lung cancer (mean, 1,633.318 ng/ml; median, 1,651.462 ng/ml; range, 342.732–4932.582 ng/ml) compared with benign lung disease (1,210.139, 1,035.900, 547.596–2,331.167 ng/ml) and normal controls (1,303.369, 1,194.800, 528.200–2140.500 ng/ml). The sensitivity and specificity of anti-IGFBP-2 autoantibodies in diagnosing lung cancer was 73.2 and 60.6%, respectively. When serum IGFBP-2 and anti-IGFBP-2 autoantibody were used together in the diagnosis of lung cancer, it can increase the discriminative power for lung cancer with a sensitivity of 85.7% and a specificity of 57.5%. In conclusion, this study demonstrates that circulating anti-IGFBP-2 autoantibodies can be used as a potential biomarker in diagnosing lung cancer.

Heat shock protein 70 silencing enhances apoptosis inducing factor-mediated cell death in hepatocellular carcinoma HepG2 cells

Heat-shock protein 70 (HSP70) abundantly expressed in human tumors and protects cells from a wide range of apoptotic stimuli. To study the role of HSP70 in human hepatocarcinomas, we stably silenced HSP70 gene expression in HepG2 cells by transfecting the cells with HSP70-silencing vector (HSP70 shRNA). HSP70 silencing resulted in reduced capacities for cell proliferation in vitro and colony formation in soft agar. In addition, HSP70 silencing enhanced chemotherapy drug-induced cell death and tumor growth in a mouse xenograft model. Most importantly, we extended our previous observation that HSP70 modulates mitochondrial protein Apoptosis-inducing factor (AIF)-induced cell death. In this study, we found that HSP70 silencing dramatically increased AIFΔ1-120 mutant (an active form of AIF after deletion of the mitochondria localization domain)-induced apoptosis. In HSP70 silenced cells, AIFΔ1-120 mutant predominantly localized in nuclear compartment compared to the control cells, confirming that HSP70 protects from apoptosis by sequestering AIF in the cytoplasm. Taken together, our data suggest that HSP70 ablation in combination with delivery of AIFΔ1-120 mutant or other chemotherapy drugs represents a potent anti-cancer therapy for hepatocarcinomas.

Linc00963: A novel, long non-coding RNA involved in the transition of prostate cancer from androgen-dependence to androgen-independence

Whole genome transcriptomic analyses have identified a large number of long non-coding RNAs (lncRNAs), many of which are involved in a variety of biological functions. However, their functions and molecular mechanisms associated with prostate cancer (PCa) progression to a virulent and androgen-independent (AI) form remain elusive. Herein, we investigated the lncRNA expression profiles of the indolent, androgen-dependent (AD) LNCaP cell line to the aggressive metastatic, AI C4-2 cell line using microarray technology. The differentially expressed lncRNAs and genes were identified by microarray technology and the association in cis or in trans was analyzed to find potential lncRNA target genes. Expression of candidate lncRNAs and putative targets was evaluated by real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The functions of linc00963 on cell proliferation, apoptosis, migration and invasion were evaluated by a knockdown strategy in vitro using MTT, flow cytometric analysis and transwell chamber assays. lncRNAs (n=134) were differentially expressed (FDR<0.001 and fold change≥2) between the LNCaP and C4-2 cell lines. Linc00963 was upregulated most obviously evaluated by qRT-PCR. Knockdown of linc00963 attenuated C4-2 cell proliferation, motility, invasion ability, the expression of EGFR and phosphorylation levels of AKT, and promoted cell apoptosis. Linc00963 was involved in the prostate cancer transition from androgen-dependent to androgen-independent and metastasis via the EGFR signaling pathway.

Selective Cytotoxicity to HER2-Positive Tumor Cells by a Recombinant e23sFv-TD-tBID Protein Containing a Furin Cleavage Sequence

Purpose: The HER2 antigen is a recognized target on breast cancer cells for immunotherapy. To overcome the immunogenicity and systemic toxicity of traditional immunotoxins, a novel human immunoproapoptotic molecule was developed and its antitumor activity was investigated. Experimental Design: Recombinant e23sFv-TD-tBID, consisting of a single-chain anti-HER2 antibody fragment linked to a human active truncated Bid by a 10–amino acid residue furin cleavage sequence, was bacterially expressed. Purified e23sFv-TD-tBID was tested for binding, internalization, and cytotoxic activity in cell and for tumor localization and antitumor activity in athymic nude mice bearing established human tumor xenografts. Results: e23sFv-TD-tBID selectively binds to HER2-positive cells and induces apoptotic cell death in vitro and in vivo. An investigation of its mechanism of action has revealed that e23sFv-TD-tBID was internalized on binding to the surface of HER2-positive tumor cells, proteolytically cleaved and transported directly to cytosol. The antitumor activity of e23sFv-TD-tBID was shown in a dose-dependent manner when injected i.p. into immunodeficient mice bearing human breast carcinomas. Moreover, this immunoproapoptotic protein, either given as a single dose or in combination with chemotherapy agents, significantly inhibited tumor growth without any observed toxic side effects on mice. Magnetic resonance imaging further showed the specific targeting and good penetration of tumors by e23sFv-TD-tBID in vivo. The therapeutic value of e23sFv-TD-tBID to human was shown by its cytotoxic effects on primary patient-derived breast tumor cells but not on endothelial cells. Conclusion: These data suggest that recombinant e23sFv-TD-tBID has therapeutic potential for HER2-positive tumors and warrant further testing for clinical applications. Clin Cancer Res; 16(8); 2284–94. ©2010 AACR.

Molecular Beacons: A Novel Optical Diagnostic Tool

As a result of the efforts of the Human Genome Project and the rise in demand for molecular diagnostic assays, the development and optimization of novel hybridization probes have focused on speed, reliability, and accuracy in the identification of nucleic acids. Molecular beacons (MBs) are single-stranded, fluorophore-labeled nucleic acid probes that are capable of generating a fluorescent signal in the presence of target, but are dark in the absence of target. Because of the high specificity and sensitivity characteristics, MBs have been used in variety of fields. In this review, MBs are introduced and discussed as diagnostic tools in four sections: several technologies of MBs will be illustrated primarily; the limitation of MBs next; the third part is new fashions of MBs; and the last one is to present the application of MBs in disease diagnosis.

Effect of socio-economic factors on delayed access to health care among Chinese cervical cancer patients with late rectal complications after radiotherapy

OBJECTIVESnTo determine the effect of socio-economic status (SES) on delayed access to medical treatment by Chinese cervical cancer patients who suffered from late rectal sequelae (LRS) after external beam radiation therapy (EBRT) and intracavitary brachytherapy.nnnMETHODSnPatients diagnosed with LRS were interviewed for their SES, factors including age, residing district, religion, marital status, income, education, insurance and patient delay (the time interval from the onset of symptoms to the first medical consultation) and other factors such as weight, symptom duration and disease stage at diagnosis.nnnRESULTSnOne hundred and twenty nine patients were interviewed. Seventy-one patients (55%) sought medical treatment within three months after the first symptom being recognized and fifty-eight patients (45%) delayed their medical treatment over 3 months. The study shows that age ≥ 55 (OR=12.1; 95% CI: 3.3-43.9), lower education (OR=4.6; 95% CI: 2.0-10.4 for women with primary school education or illiterate), low annual household income (OR=2.3; 95% CI: 1.2-5.1) and widow/divorce (OR=0.1; 95% CI: 0.01-0.07) were the high risk factors for delayed reporting. Patients with bleeding or bleeding plus other symptoms (61.2%) were more likely to seek treatment within three months, compared to patients with other symptoms only (38.8%) (p=0.002). Additionally, delayed reporting was found to be significantly associated with the late stage of late rectal sequelae (LRS) (p=0.000) and the patients with 55 years or older (p=0.000).nnnCONCLUSIONSnDelayed reporting and late-stage presentation of late rectal sequelae are more prevalent among Chinese cervical cancer patients with 55 years or older, low education, poor marital status, or poor financial status. Effective social support and educational programs should be implemented to encourage these patients to seek medical treatment as soon as possible.

The role of CDK1 in apoptin-induced apoptosis in hepatocellular carcinoma cells

Apoptin, a small protein derived from the chicken anemia virus, specifically induces apoptosis in transformed cells or tumor cells but not in normal cells. Thus, apoptin is involved in a general, tumor-specific pathway. Apoptin-induced apoptosis presumably requires additional interaction partners that activate specific signaling pathways in cancer cells. A number of molecules interact with apoptin and play an important role in the nuclear localization of apoptin or its tumor-selective cytotoxicity. Our data indicated that apoptin selectively kills HepG2 hepatocellular carcinoma (HCC) cells but has no effect on the normal liver cell line HL-7702. Analyses of human HCC tissue samples confirmed that CDK1 (cyclin-dependent kinase 1) activity was detected in primary malignancies but not in healthy paraneoplastic tissues. shRNA knockdown of CDK1 significantly reduced the tumor-specific killing effects of apoptin, suggesting that CDK1 plays an important role in the regulation of apoptin-induced apoptosis. Furthermore, the majority of apoptin translocated to the cytoplasm from the nucleus after knockdown of CDK1. Collectively, our results revealed for the first time that apoptin interacts with CDK1 in the complex process of tumorigenesis. The link between CDK1 and apoptin may be a novel cellular signaling pathway to modulate apoptosis in cancer; therefore, apoptin may have pharmacological potential to be directly employed for cancer therapy.