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Abstract Background Hepatitis delta virus (HDV) ribozyme is an attractive molecular tool that can specifically recognize and catalyze the self-cleavage of the viral RNA phosphodiester backbone. However, a major obstacle in the medical application of the HDV ribozyme is the lack of specificity in the delivery of the ribozyme to defined target cells. Results The objective of this study was to determine whether retroviral vectors can deliver the HDV ribozyme into the target cells and to elucidate whether HDV ribozyme plays a role in hepatitis B virus (HBV) replication. In our study, the transduction of helper-free pseudotyped retrovirus, which showed a broad host range, in human hepatoma cells was performed under 2 conditions, that is, in the presence of polymerized human serum albumin (pHSA) and in the absence of pHSA. The transduction ability in the presence of pHSA was higher than in the absence of pHSA. Moreover, HBsAg and HBeAg levels after transductions with pHSA were significantly lower than those in the absence of pHSA, thus indicating that the recombinant retrovirus had HBV-specific cleavage activity and targeted HepG2215 cells. Conclusions These data suggest that this system provides a new approach for targeting hepatocytes and has a great potential in gene therapy for HBV infection.

Upregulation of histone methyltransferase SET domain bifurcated 1 (SETDB1) is associated with poor prognosis in cancer patients. However, the mechanism of oncogenicity of SETDB1 in cancer is hitherto unknown. Here, we show that SETDB1 is upregulated in human colorectal cancer (CRC) where its level correlates with poor clinical outcome. Ectopic SETDB1 promotes CRC cell proliferation, whereas SETDB1 attenuation inhibits this process. Flow cytometry reveals that SETDB1 promotes proliferation by driving the CRC cell cycle from G0/G1 phase to S phase. Mechanistically, SETDB1 binds directly to the STAT1 promoter region resulting in increased STAT1 expression. Functional characterization reveals that STAT1-CCND1/CDK6 axis is a downstream effector of SETDB1 -mediated CRC cell proliferation. Furthermore, SETDB1 upregulation is sufficient to accelerate in vivo proliferation in xenograft animal model. Taken together, our results provide insight into the upregulation of SETDB1 within CRC and can lead to novel treatment strategies targeting this cell proliferation-promoting gene. [ABSTRACT FROM AUTHOR]

The expression of microRNA (miR-433) is altered in various types of human cancer. The present study analyzed the prognostic and biological value of miR-433 expression in colorectal cancer using reverse transcription-quantitative polymerase chain reaction in 125 colorectal tissue specimens (including a test cohort of 40 cases of paired colorectal cancer and adjacent normal mucosae and a confirmation cohort of 85 cases of stage I-III colorectal cancer). In vitro and nude mouse xenograft experiments were subsequently used to assess the effects of miR-433 expression on the regulation of colorectal cancer cell proliferation, adhesion, migration, and invasion. The data indicated that miR-433 expression was significantly downregulated in colorectal cancer tissues in the test and confirmation patient cohorts and that low miR-433 expression was associated with advanced tumor stage and early relapse. Furthermore, the restoration of miR-433 expression was able to significantly inhibit the proliferation of tumor cells by inducing G1-S cell cycle arrest, suppressing cyclinD1 and CDK4 expression, and markedly inhibited the migratory and invasive capacities of tumor cells in vitro. The restoration of miR-433 expression or liposome-based delivery of miR-433 mimics suppressed the growth of colorectal cancer cell xenografts in nude mice. In conclusion, miR-433 may be a putative tumor suppressor in colorectal cancer, and the detection of low miR-433 expression will be investigated in further studies as a putative biomarker for the detection of early relapse in patients with colorectal cancer. [ABSTRACT FROM AUTHOR]

The aim of this study was to ascertain the diagnostic value of serum squamous cell carcinoma antigen (SCCA) and SCCA-IgM for hepatocellular carcinoma (HCC). After a comprehensive search of PubMed and Web of Science databases, we identified eligible studies on the diagnostic value serum SCCAs for HCC. The quality of the eligible studies was assessed using the revised Quality Assessment for Studies of Diagnostic Accuracy (QUADAS-2) tool. The overall diagnostic value of SCCAs for HCC was pooled using a bivariate model. Twelve studies were included in this systematic review and meta-analysis. The pooled sensitivities for SCCA and SCCA-IgM were 0.61 (95% confidence interval [CI], 0.37–0.81) and 0.70 (95% CI, 0.55–0.82), respectively. The corresponding specificities were 0.80 (95% CI, 0.52–0.94) and 0.62 (95% CI, 0.51–0.72), respectively. The areas under summary receiver operating characteristic (sROC) curves for SCCA and SCCA-IgM were 0.76 (95% CI, 0.72–0.80) and 0.70 (95% CI, 0.66–0.74), respectively. Major design deficiencies of the included studies were two-gate design and partial verification bias. Therefore, we concluded that both serum SCCA and SCCA-IgM have a fair diagnostic value for HCC. [ABSTRACT FROM PUBLISHER]

Background and Aims: MicroRNAs (miRNA) can act as oncogenes or tumor suppressors. Polymorphisms present in pri-, pre- and mature miRNAs can potentially modulate the expression of hundreds of genes, broadly affecting miRNA function. Notably, the rs11614913 SNP in miR-196a2 has been implicated in carcinogenesis, but its association with colorectal cancer (CRC) remains unexplored. We performed a case−control study to investigate the genetic association between this functional SNP and CRC susceptibility and progression. Methods: We genotyped the rs11614913 SNP in 252 CRC patients and 543 healthy controls by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). In addition, we examined miR-196a expression level in colorectal cancer tissues (n = 50) obtained from the studied CRC patients. Results: Frequency of the CC genotype was higher in CRC patients than controls, implying that the subjects with the CC genotype or C allele containing genotypes (CT and CC) have a higher risk of CRC. However, no significant association between this polymorphism and CRC progression was observed. Expression analysis revealed that rs11614913 CC or carrying at least one C allele was associated with a significantly increased level of mature miR-196a (p = 0.010 or = 0.022). Conclusions: The present study provides the first evidence that miR-196a2 polymorphism may contribute to CRC susceptibility in a Chinese population through modulating mature miR-196a expression. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the role of [18F] fluorodeoxyglucose positron emission tomography (FDG-PET) in influencing salvage treatment decision making for locally persistent nasopharyngeal carcinoma (NPC). Methods and Materials: A total of 33 NPC patients with histologic persistence at nasopharynx 1 to 6 weeks after a full course of radiotherapy underwent both computed tomography (CT) and FDG-PET/CT simulation at the same treatment position. The salvage treatment decisions, with regard to the decision to offer salvage treatment and the definition of gross tumor volume (GTV), were made before knowledge of the FDG-PET findings. Subsequently the salvage treatment decisions were made again based on the FDG-PET findings and compared with the pre-FDG-PET decisions. Results: All 33 patients were referred for salvage treatment in the pre-FDG-PET decision. After knowledge of the FDG-PET results, the decision to offer salvage treatment was withdrawn in 4 of 33 patients (12.1%), as no abnormal uptake of FDG was found at nasopharynx. Spontaneous remission was observed in repeat biopsies and no local recurrence was found in these 4 cases. For the remaining 29 patients, GTV based on FDG-PET was smaller than GTV based on CT in 24 (82.8%) cases and was greater in 5 (17.2%) cases, respectively. The target volume had to be significantly modified in 9 of 29 patients (31%), as GTV based on FDG-PET images failed to be enclosed by the treated volume in the salvage treatment plan performed based on GTV based on CT simulation images. Conclusion: Use of FDG-PET was found to influence the salvage treatment decision making for locally persistent NPC by identifying patients who were not likely to benefit from additional treatment and by improving accuracy of GTV definition in salvage treatment planning. [ABSTRACT FROM AUTHOR]

Objective: To detect the expression of miR-124 in colorectal carcinoma (CRC) cells and tissue specimens and analyze its association with the radiosensitivity of the cells., Methods: The expression of miR-124 in CRC cell lines and tissues were detected using qRT-PCR. The effect of miR-124 in modulating cell radiosensitivity was assessed in CRC cells with miRNA-124 overexpression and miRNA-124 knockdown, and bioinformatics prediction and dual luciferase reporter system were employed to identify the direct target of miR-124., Results: s miR-124 expression was down-regulated in CRC cell lines and tissues. CRC cells over-expressing miR-124 showed an obviously enhanced radiosensitivity, whereas miR-124 knockdown resulted in a reduced radiosensitivity of the cells. Bioinformatics prediction and dual luciferase reporter system verified PRRX1 as a direct target of miR-124, which regulated the radiosensitivity of CRC cells by directly inhibiting PRRX1., Conclusion: miR-124 can enhance the radiosensitivity of CRC cells by directly targeting PRRX1, which provides a target for improving the therapeutic effect of radiotherapy of CRC.

Objective: To evaluate the effect of gemcitabine in enhancing the radiosensitivity of hepatoma cell line HepG2 and explore its mechanisms., Methods: Clonogenic survival assay is employed to calculate the ratios of L-Q model radiation biology parameters and radiosensitization after different doses of irradiation. Flow cytometry was used to detect the changes in HepG2 cell cycle and apoptosis rate after gemcitabine treatment and radiation exposure., Results: The survival fraction at 2 Gy of HepG2 cells treated with gemcitabine was significantly lower, and the value of alpha was significantly higher than those of untreated cells. GEM treatment increased the percentage of radiation-induced G0/G1 phase cells and cell apoptosis., Conclusion: Gemcitabine can significantly enhance the radiosensitivity of HepG2 cells by enhancing radiation-induced cell cycle arrest in G0/G1 phase and cell apoptosis.

Objective: To define the planning target volume (PTV) margins in intensity-modulated radiotherapy (IMRT) for prostate cancer without imaging guidance using B-mode acquisition and targeting (BAT) ultrasound-based prostate localization., Methods: Ten patients with prostate cancer underwent BAT ultrasound alignment before each IMRT session. The set-up deviations, each consisting of isocenter displacements in 3 directions (anterior-posterior, right-left lateral, and superior-inferior), were recorded for a total of 225 times and analyzed with Kolmogorov-Smimov (K-S) method., Results: The isocenter shift in each direction, which represented an average from all the patients, was 3.56∓2.71 mm, 4.08∓3.99 mm, and 3.20∓2.92 mm in the lateral (RL), anteroposterior (AP), and superior-inferior (SI) dimensions, respectively, and the deviations in each direction conformed to a normal distribution (P=0.806, P=0.061, and P=0.106, respectively). In the absence of imaging guidance for IMRT for prostate cancer, the PTV margin should expand by 8.97 mm in the right, 1.87 mm in the left, 12.05 mm in the anterior, 3.91 mm in the posterior, 9.06 mm in the superior and 2.66 mm in the inferior to allow 95% isodose curve to cover 90% of the clinical target volume., Conclusion: The ultrasound imagining guided localization, with simple operation, nonirradiation and small systemic error, can be real-time corrected.

Breast cancer-initiating cells are a relatively radioresistant subpopulation of breast cancer cells. However, the mechanism of this radioresistance is still unclear. This study aimed to investigate the effect of radiation on the levels of signal transducer and activator of transcription 1 (STAT1) in mammospheres of cancer-initiating cells and monolayer cultures of MCF-7 cells. We isolated CD44(+)/CD24(-/low) cancer-initiating cells from MCF-7 cells and propagated them as mammospheres. Next we used realtime quantitative reverse-transcriptase polymerase chain reaction to examine the mRNA level of STAT1 in mammospheres of breast cancer-initiating cells and monolayer cultures of MCF-7 cells. The apoptosis rate and surviving fraction using clonogenic assays was observed after treating the cells with a STAT1 inhibitor. After irradiation, the STAT1 level in the mammospheres was higher than that in the monolayer cultures. STAT1 inhibitor treatment did not cause significant changes in the apoptosis rate and surviving fraction in the MCF-7 monolayer cultures. However, the inhibitor treatment caused significant differences in the apoptosis rate and surviving fraction in mammospheres. Our study provides the first evidence that STAT1 signaling contributes to radioresistance in breast cancer-initiating cells and reveals STAT1 as a promising target to reduce radioresistance and enhance the efficacy of radiotherapy for breast cancer.

Increasing evidence indicates that stimulating hippocampal neurogenesis could provide novel avenues for the treatment of depression, and recent studies have shown that in vitro neurogenesis is enhanced by hypoxia. The aim of this study was to investigate the potential regulatory capacity of an intermittent hypobaric hypoxia (IH) regimen on hippocampal neurogenesis and its possible antidepressant-like effect. Here, we show that IH promotes the proliferation of endogenous neuroprogenitors leading to more newborn neurons in hippocampus in adult rats. Importantly, IH produces antidepressant-like effects in multiple animal models screening for antidepressant activity, including the forced swimming test, chronic mild stress paradigm, and novelty-suppressed feeding test. Hippocampal x-ray irradiation blocked both the neurogenic and behavioral effects of IH, indicating that IH likely produces antidepressant-like effects via promoting neurogenesis in adult hippocampus. Furthermore, IH stably enhanced the expression of BDNF in hippocampus; both the antidepressant-like effect and the enhancement of cell proliferation induced by IH were totally blocked by pharmacological and biological inhibition of BDNF-TrkB (tyrosine receptor kinase B) signaling, suggesting that the neurogenic and antidepressant-like effects of IH may involve BDNF signaling. These observations might contribute to both a better understanding of physiological responses to IH and to developing IH as a novel therapeutic approach for depression.

Objective: To explore the effect of NAD+ against radiation injury and its dose-effect relationship., Methods: L02 liver cells cultured in RPMI 1640 medium containing 10% fetal calf serum were exposed to X-ray irradiation followed by immediate application of NAD+. The cellular viability was analyzed by MTT assay and the apoptotic cells were detected by TUNEL methods to observe the damages of L02 liver cells induced by X-ray exposure and analyze the dose-effect relationship of NAD+., Results: The viability of L02 liver cells was decreased with increasing dose of X-ray irradiation. The most obvious growth inhibition of L02 cells occurred 24 h after the irradiation. NAD+ significantly increased the cell survival rate after irradiation, and this effect was gradually increased within the concentration range of 100-1000 microg/ml; at higher concentrations, the survival rate of the irradiated L02 cells showed no significant increase., Conclusion: NAD+ provides partial protection of the liver cells against radiation injury, and the effect is positively correlated to NAD+ concentration within a certain range.

Objective: To investigate the effects of radiosensitivity and X-ray dose on the expression of miR-7 in nasopharyngeal carcinoma (NPC) cells., Methods: Low radiosensitive NPC cells CNE-1 and high radiosensitive NPC cells CNE-2 were exposed to 0, 2 and 8 Gy X-ray. The total RNAs of the cell lines were extracted 10 h after radiation for reverse transcription of miR-7 and 18S rRNA by stem-loop primer and random hexamers, respectively. The non-irradiated CNE-1 cells served as the control sample and the relative quantity of the expression level was calculated after real-time PCR using SyBR green., Results: miR-7 expression differed significantly between CNE-1 and CNE-2 cells (4.49-/+3.62 vs 1.29-/+1.10, F=135.483, P<0.001). The radiation dose also significantly affected the expression of miR-7 in NPC cells (F=39.565, P<0.001). CNE-1 cells with a 2 Gy exposure had the highest expression level of miR-7, while the non-irradiated CNE-1 cells had the lowest expression. CNE-2 cells exposed to 2 Gy X-ray had the lowest expression level of miR-7 and the non-irradiated CNE-2 cells had the highest., Conclusion: Radiosensitivity and radiation dose of X-ray have significant effect on the expression of miR-7 in NPC cells, indicating that miR-7 plays an important role in radioresistance of NPC cells to X-ray, and suppressed miR-7 expression may elevate the radiosensitivity of NPC cells.

Objective: To study the protective effect of ginsenoside Rg1 on cultured rat hippocampal neurons against radiation injury and explore new therapies for preventing radiation encephalopathy., Methods: Rat hippocampal neurons cultured for 12 days were subjected to a single-dose X-ray exposure of 30 Gy. 4',6-diamidino-2-phenylindole (DAPI) staining was used to detect the neuronal apoptosis and NOS activity kit utilized to evaluate NOS activity in the cells after the exposure., Results: Nuclear condensation was detected in (25.3-/+3.57)% of the neurons 24 h after 30 Gy X-ray exposure, a rate significantly higher than that in the control cells [(1.95-/+0.78)%, P<0.01]. In the neurons pretreated with ginsenoside Rg1, only (7.43-/+1.51)% of the cells presented with nuclear condensation after the exposure, significantly different from the rates in the control cultures and the exposed cultures (P<0.01). The NOS activity of exposed cultures was 6.46-/+0.95 U/ml, significantly higher than that in the control cultures (3.20-/+0.70 U/ml, P<0.01). The NOS activity of the neurons pretreated with ginsenoside Rg1 was 3.85-/+0.69 U/ml, significantly different from that in the control cultures (P<0.05) and the exposed cultures (P<0.01)., Conclusion: Ginsenoside Rg1 offers significant protective effect on rat hippocampal neurons from radiation-induced apoptosis by reducing the activity of NOS.

Objective: To investigate the role of lung fibroblast activation in radiation-induced lung injury., Methods: Thirty-five male Wistar rats were exposed to a single-dose 30 Gy irradiation of the right hemithorax or sham right lung irradiation. At 1, 7, 14, 28, 56 or 84 days after the irradiation, the rats were sacrificed for examination of alpha-smooth muscle actin (alpha-SMA) expression in the bilateral lung tissues using immunohistochemistry., Results: alpha-SMA expression in fibroblast increased significantly in the out-field and in-field lung tissues within 24 h after irradiation after the irradiation (P<0.001)., Conclusion: Activation of the lung fibroblasts occurred within 24 h after irradiation and found in ont-field and in-field lung tissues, suggesting that radiation-induced lung injury may not have an obvious latency.

Objective: To investigate the differential expression of microRNAs between human hepatocellular carcinoma (HCC) and liver cirrhosis (LC)., Methods: The total RNA was extracted from 25 pairs of HCC and LC tissues. microRNA microarray was used to analyze the microRNA expression profiles, and validation of the microarray results was carried out by real-time quantitative RT-PCR (qRT-PCR)., Results: Three microRNAs exhibited higher expression in the HCC samples than in the LC samples. In comparison with the LC samples, the HCC samples showed down-regulated expressions of 9 microRNAs. qRT-PCR verified that has-miR-122a, has-miR-199a, and has-miR-199b were downregulated in HCC, which was in agreement with the microarray results., Conclusion: HCC and LC samples have significantly different microRNA expression profiles. These differentially expressed microRNAs may be involved in the pathogensis of HCC.

Objective: To determine the repair half-time (T1/2), a speed parameter of sub-lethal damage repair (SLDR), of human nasopharyngeal carcinoma (NPC) cell lines CNE1, HONE1, C666-1 and CNE2., Methods: A total radiation dose of 8 Gy divided into 4+4 Gy was delivered to the cell lines at the interval of 0 s, 15 s, 30 s, 1 h, 2 h, 4 h or 6 h. The cell survival fractions were determined using the standard cell clonogenic assay. The curves of the changes in the surviving cell fraction after a total dose of 8 Gy, as a function of the interval between the two doses of 4 Gy, were fitted manually, and the T1/2 of each cell line was calculated according to the curves., Results: The T1/2 of CNE1, HONE1, C666-1 and CNE2 were 18 s, 22 s, 29 s and 27 s, respectively., Conclusion: The speed of SLDR of NPC cells is quite rapid, indicating that the fraction delivery time longer than 20 s might decrease the effect of radiotherapy.

Objective: To evaluate the outcomes of patients with unresectable massive primary liver cancer (PLC) receiving three-dimensional conformal radiotherapy (3-DCRT) combined with transcatheter arterial chemoembolization (TACE)., Methods: From January 2001 to December 2004, 84 patients with unresectable massive PLC (tumor size> or =10 cm) received 3-DCRT combined with TACE, including 49 cases in UICC/AJCC T(3) stage and 35 cases in T(4) stages. Lymph node metastasis was found in none of the patients, and portal vein tumor thrombosis (PVTT) was detected in 30 cases. Child-Pugh grade A of liver cirrhosis was present in 64 cases and grade B in 20 cases. The mean value of GTV was 705-/+430 cm(3) (170-2099 cm(3)). Following injections of fluorouracil and hydroxycamptothecine into the target artery of the tumor, the mixture of carboplatin, mitomycin (or pirarubicin) and super-liquefactive iodized oil was injected into the target artery. Gelatin sponge was used to embolize the artery. The procedure was repeated every 1.5-2 months according to the condition of the patients, and each patient received 1-3 such procedures. 3-DCRT was performed in all the patients, who received a total dose of 53.6-/+6.6 Gy (4-6 Gy per fraction at the interval of 48 h), and 3 fractions were given every week., Results: Eight patients died in 3 months after 3-DCRT and were not evaluated. The total response rate (CR+PR) in these patients was 68.9% (51/74). The overall survival rates at 1, 2 and 3 years were 55.4%, 24.7% and 15.4%, respectively. T stage, GTV, PVTT and fraction size had no significant impact on the overall survival. Child-Pugh grade was found to have significant impact on the patients' survival (P=0.035, RR=2.440)., Conclusion: 3-DCRT combined with TACE has definite therapeutic effect on advanced massive PLC, and Child-Pugh grade is an independent prognostic factor in such cases.

Objective: To investigate the effects of X-ray exposure on the release of soluble tumor necrosis factor receptor-p75 (sTNFR-p75) in hepatocellular carcinoma HepG2 cells in vitro., Methods: Enzyme-linked immunosorbent assay (ELISA) was used to examine the levels of sTNFR-p75 in the supernatants of HepG2 cells before and after X-ray exposure. The cell apoptosis was analyzed by flow cytometry and transmission electron microscope(TEM), and the morphological changes of the cells were examined under optical microscope and transmission electron microscope(TEM)., Results: X-ray exposure of the cells resulted in a strong increase of cell apoptosis (P<0.05) and sTNFR-p75 production in the cells as compared with the those before the exposure (P<0.01). Optical microscopy revealed apoptotic changes of HepG2 cell after the exposure, shown as cell shrinkage, spherical cell morphology, cytoplasmic and nuclear condensation. Apoptotic bodies were detected by TEM., Conclusion: X-ray exposure induces HepG2 cells apoptosis by inhibiting the release of sTNFR-p75 into the supernatant.

Objective: To explore the correlation of the expressions of metastatic tumor antigen 1 (MTA1) and hypoxia-inducible-factor l alpha (HIF-1alpha) to the clinical features of lung cancer., Methods: The expressions of MTA1 and HIF-1alpha proteins in 59 lung cancer patients were detected by immunohistochemistry., Results: Positive staining of MTA1 and HIF-1alpha was found in 54.24% and 50.85% of the patients, respectively. MTA1 expression was not found to correlated to any of the clinical parameters. HIF-1alpha expression was significantly lower in poorly differentiated than in moderately and well differentiated lung cancer (P<0.05), and a positive association between the expressions of MTA1 and HIF-17alpha were noted (P<0.05)., Conclusion: MTA1 and HIF-1alpha overexpression occurs in lung cancer possibly as an important factor of lung carcinogenesis. MTA1 may promote lung carcinogenesis by enhancing HIF-1alpha protein activity.