Biomarker studies on radiotherapy to hepatocellular carcinoma

Universal ratiometric electrochemical biosensing platform based on mesoporous platinum nanocomposite and nicking endonuclease assisted DNA walking strategy

The occurrence and development of many complex diseases are associated with various molecules, whose contents are rarely in the early stage of the disease. Thus a universal platform for the ultrasensitive detection of multilevel biomarkers should be developed. In this study, we introduced an electrochemical biosensing system based on nicking endonuclease (Nt.BbvCI) assisted DNA walking strategy. We successfully constructed a universal signal-off-on ratiometric electrochemical biosensor for various biomolecules, including small molecules, nucleic acids, and proteins, by progressively optimizing the schematics (schemes 1, 2, and 3). The MB-hairpin probes (MB-HPs) acted as a signal-off probe, and nanocomposites (MPNs@DOX@DNA2) acted as a conventional signal-on probe (scheme 3). With the aid of the MPNs@DOX@DNA2 and Nt.BbvCI assisted DNA walking mechanism, the designed ratiometric electrochemical biosensor showed a high sensitivity and broad detection range. In addition, the proposed method can be utilized to detect diverse targets quantitatively by changing the sequence of aptamers under optimum experimental conditions. Furthermore, it has been widely proved to realize well-accepted signal response in identifying complex samples, thereby resulting in an wide prospect for bioanalysis and clinical diagnosis.

External beam radiotherapy for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm, the sixth most common cancer worldwide, and the third most common cause of cancer mortality. Moreover, its incidence has increased dramatically in the past decade. While surgical resection and liver transplantation are the main curative treatments, only around 20% of people with early hepatocellular carcinoma may benefit from these therapies. Current treatment options for unresectable hepatocellular carcinoma include various ablative and transarterial therapies in addition to the drug sorafenib.

OBJECTIVES

To assess the benefits and harms of external beam radiotherapy in the management of localised unresectable hepatocellular carcinoma.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), Science Citation Index Expanded (Web of Science), and clinicaltrials.gov registry. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to October 6, 2016.

SELECTION CRITERIA

Eligible studies included all randomised clinical trials comparing external beam radiotherapy either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for people with unresectable hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used a random-effects model as well as a fixed-effect model meta-analysis but in case of discrepancy between the two models (e.g. one giving a significant intervention effect, the other no significant intervention effect), we reported both results; otherwise, we reported only the results from the fixed-effect model meta-analysis. We assessed risk of bias of the included trials using predefined risk of bias domains; assessed risks of random errors with Trial Sequential Analysis; and presented the review results incorporating the methodological quality of the trials using GRADE.

MAIN RESULTS

Nine randomised clinical trials with 879 participants fulfilled our inclusion criteria. All trials were at high risk of bias, and we rated the evidence as low to very low quality. All of the included trials compared combined external beam radiotherapy plus chemoembolisation versus chemoembolisation alone in people with unresectable hepatocellular carcinoma; moreover, three of the trials compared external beam radiotherapy alone versus chemoembolisation alone. All trials were conducted in China. The median age in most of the included trials was around 52 years, and most trial participants were male. The median follow-up duration ranged from one to three years. None of the trials reported data on cancer-related mortality, quality of life, serious adverse events, or time to progression of the tumour. For the comparison of radiotherapy plus chemoembolisation versus chemoembolisation alone, the risk ratio for one-year all-cause mortality was 0.51 (95% confidence interval (CI) 0.41 to 0.62; P < 0.001; 9 trials; low-quality evidence); for complete response rate was 2.14 (95% CI 1.47 to 3.13; P < 0.001; 7 trials; low-quality evidence); and for overall response rate defined as complete response plus partial response was 1.58 (95% CI 1.40 to 1.78; P < 0.001; 7 trials; low-quality evidence), all in favour of combined treatment with external beam radiotherapy plus transarterial chemoembolisation and seemingly supported by our Trial Sequential Analysis. Additionally, the combined treatment was associated with a higher risk of elevated total bilirubin and elevated alanine aminotransferase. The risk ratio for the risk of elevated alanine aminotransferase was 1.41 (95% CI 1.08 to 1.84; P = 0.01; very low-quality evidence), while for elevated total bilirubin it was 2.69 (95% CI 1.34 to 5.40; P = 0.005; very low-quality evidence). For the comparison of radiotherapy versus chemoembolisation, the risk ratio for one-year all-cause mortality was 1.21 (95% CI 0.97 to 1.50; 3 trials; I² = 0%; very low-quality evidence) which was not supported by our Trial Sequential Analysis.In addition, we found seven ongoing randomised clinical trials evaluating different external beam radiotherapy techniques for people with unresectable hepatocellular carcinoma.

AUTHORS' CONCLUSIONS

We found very low- and low-quality evidence suggesting that combined external beam radiotherapy and chemoembolisation may be associated with lower mortality and increased complete and overall response rates, despite an increased toxicity as expressed by a higher rise of bilirubin and alanine aminotransferase. A high risk of systematic errors (bias) as well as imprecision and inconsistency suggest that these findings should be considered cautiously and that high-quality trials are needed to assess further the role of external beam radiotherapy for unresectable hepatocellular carcinoma.

Radiotherapy for Hepatocellular Carcinoma: New Indications and Directions for Future Study

Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide; its incidence is increasing in the United States. Depending on disease extent and underlying liver status, patients may be treated with local, locoregional, and/or systemic therapy. Recent data indicates that radiotherapy (RT) can play a meaningful role in the management of HCC. Here, we review published experiences using RT for HCC, including the use of radiosensitizers and stereotactic RT. We discuss methods for performing preclinical studies of RT for HCC and biomarkers of response. As a part of the HCC Working Group, an informal committee of the National Cancer Institute's Radiation Research Program, we suggest how RT should be implemented in the management of HCC and identify future directions for the study of RT in HCC.

In Situ Proximity Ligation Assay (PLA)

In situ proximity ligation assay (PLA) is a method to identify physical closeness of proteins, where a signal will only be produced if the two proteins are closer than 40 nm, in tissue section or cell cultures. Modifications of the PLA method can also be used to increase specificity or sensitivity of standard immunohistochemistry protocols.

Stanniocalcin 2 expression predicts poor prognosis of hepatocellular carcinoma

Previous studies have shown that the expression level of stanniocalcin 2 (STC2) is associated with tumor progression. However, to date, the association between STC2 and clinicopathological factors in hepatocellular carcinoma (HCC) has not been investigated. The clinical significance of STC2 was investigated in 30 fresh HCC samples using western blot analysis and in 240 HCC tissues using immunohistochemical analysis. The level of STC2 in cancerous tissue was higher than in the matched non-cancerous tissues. Using immunohistochemistry, the STC2-positive group exhibited a higher incidence of lymph node metastasis and venous invasion compared with the STC2-negative group. Kaplan-Meier survival analysis revealed that the positive expression of STC2 correlated with poor overall survival (OS) and disease-free survival of HCC patients (P<0.01). STC2 expression was observed to be an independent prognostic factor for OS in HCC patients by multivariate analysis (hazard ratio, 2.39; 95% confidence interval, 1.04–5.89; P=0.013). These data suggest that STC2 expression may be a useful indicator of poor prognosis in HCC patients.

An underlying prognosis predictor of hepatocellular carcinoma: Oncoprotein 18

Recent studies have reported the association between the expression of oncoprotein 18 (op18) and hepatocellular carcinoma (HCC). However, any underlying mechanistic connection between op18 expression and hepatocarcinogenesis is poorly understood. In the present study, Flag-pcDNA3.1 vector and Flag-pcDNA3.1-op18 plasmid were stably transfected in SMMC7721 cells, respectively. Stable SMMC7721 control and op18 overexpression SMMC7721 cell lines were constructed and identified by western blot analysis. Using a cell counting kit-8 (CCK8), it was shown that cell proliferation was significantly increased in the op18 overexpression SMMC7721 cell group (0.60±0.05), compared with the control group (0.29±0.03) at an absorbance of 450 nm (P<0.01). Flow cytometry was used to analyze cell apoptosis by FITC-Annexin V and propidium iodide (PI) apoptosis assay kit. The results demonstrated that the percentage of apoptotic cells was inhibited to 5.80±0.33% in the op18 overexpression group, compared with 11.79±1.09% in the control group. Using FACS, single cell analysis data showed that op18 overexpression induced cell cycle arrest by inhibiting progression from G2 to M phase. The results suggest that op18 expression is closely associated with SMMC7721 cell proliferation and apoptosis, which appears to be a potential predictor of prognosis in HCC.