Suxia Han

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.

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.

Using immunoproteomics to identify tumor-associated antigens (TAAs) as biomarkers in cancer immunodiagnosis

Since intracellular proteins involved in carcinogenesis have been shown to provoke autoantibody responses, autoantibodies can be used as probes in immunoproteomics to isolate, identify, and characterize potential tumor-associated antigens (TAAs). Once a TAA is identified, several approaches will be used to comprehensively characterize and validate the identified TAA/anti-TAA systems that are potential biomarkers in certain types of cancer. Our ultimate goal is to establish rigorous criteria for designation of an autoantibody to a TAA as a cancer biomarker, examine candidate TAAs for sensitivity and specificity of anti-TAA antibody response, and further develop customized TAA arrays that can be used to enhance anti-TAA antibody detection in cancer. This review will mainly focus on the recent advances in our studies using immunoproteomic approach to identify and characterize TAAs as biomarkers in cancer.

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.

Speckle-type POZ protein, SPOP, is involved in the DNA damage response

Speckle-type POZ protein (SPOP) is an adaptor of the cullin 3-based ubiquitin ligase responsible for the degradation of oncoproteins frequently overexpressed in many tumor cells. Altered expression and somatic mutations of SPOP have been observed in various tumor types with chromosomal aberrations, indicating a role of SPOP in maintaining genome stability, although a detailed mechanism remains unclear. Here, we show that SPOP is a component of the DNA damage response (DDR). SPOP is recruited to DNA double-strand break sites and it forms nuclear foci after DNA damage. SPOP foci colocalize with γ-H2AX foci and are predominantly dependent on the activity of the ataxia-telangiectasia mutated (ATM) kinase. Furthermore, SPOP interacts with ATM in response to DNA damage. Finally, we demonstrate that knocking down of SPOP resulted in an impaired DDR and a hypersensitivity to ionizing irradiation. Together, we highlight a critical role of SPOP in the DDR.

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

OBJECTIVES To 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. METHODS Patients 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. RESULTS One 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). CONCLUSIONS Delayed 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 PAM4 in the Management of Pancreatic Cancer: Diagnosis, Radioimmunodetection, and Radioimmunotherapy

PAM4, a new monoclonal antibody (MAb) known as clivatuzumab, is highly reactive with pancreatic cancer and precursor lesions. It is absent from the normal tissues and has limited reactivity with nonpancreatic cancer. The detailed characteristic of the PAM4 epitope is unknown but recent studies have shown that it is dependent on MUC1 glycosylation status. The limited PAM4 expression pattern makes it an attractive candidate for management of pancreatic adenocarcinoma. In addition, PAM4 is a serum biomarker for diagnosis of pancreatic cancer. Several different radiolabeled immunodiagnostic and immunotherapeutic agents of PAM4 have been developed and some are being evaluated in preclinical and/or clinical studies. The review will focus on PAM4 and its potential utility for the diagnosis, radioimmunodetection, and radioimmunotherapy of pancreatic cancer.