[Corrigendum] Enhanced antitumor activity by the combination of dasatinib and combretastatin A­4 in vitro and in vivo.

Following the publication of this article, an interested reader drew to the authors' attention that the flow cytometric (FCM) plots in Fig. 2A on p. 2278 showing the 'Dasatinib' and 'CA­4' experiments were duplicates of each other. After having re­examined their original data, and due to the overall similarity of the data, the authors have realized that these data were inadvertently assembled incorrectly in the figure. They realize that they also made a further mistake regarding the writing of the ratios of mitochondrial membrane­depolarized HO­8910 cells for these FCM plots (essentially, these were written the wrong way around): The percentage of mitochondrial membrane­depolarized HO­8910 cells should have been written as 22.50% for the dasatinib­treated cells (the centre­left FCM plot) and 15.71% for the CA­4­treated cells (centre­right plot). A revised version of Fig. 2 now showing alternative data for the FCM experiments shown in Fig. 2A, is shown on the next page. Note that the errors made in terms of assembling the data in Fig. 2A did not greatly affect either the results or the conclusions reported in this paper, and all the authors agree with the publication of this corrigendum. The authors regret that these errors went unnoticed prior to the publication of their article, and are grateful to the Editor of Oncology Reports for granting them this opportunity to publish a corrigendum. Furthermore, they apologize to the readership for any inconvenience caused. [Oncology Reports 29: 2275­2282, 2013; DOI: 10.3892/or.2013.2405].

Enhanced antitumor activity by the combination of dasatinib and combretastatin A-4 in vitro and in vivo.

The present study showed that the combination of dasatinib and combretastatin A-4 (CA-4) exhibited synergistic cytotoxicity in multiple types of cancer, including ovarian, hepatocellular, lung and prostate carcinoma. The enhanced apoptosis induced by dasatinib plus CA-4 was accompanied by a greater extent of mitochondrial depolarization, caspase-3 activation and PARP cleavage in HO-8910 cells. Furthermore, elevated expression of Mcl-1 led to a reduced apoptosis induced by dasatinib plus CA-4, highlighting that downregulated Mcl-1 was necessary for the potentiating effect of dasatinib to CA-4-triggered apoptosis. A clear increase in γ-H2AX expression was observed in the dasatinib+CA-4 group compared with the mono-treatment groups, indicating that dasatinib plus CA-4 may induce double-strand breaks (DSBs) in HO-8910 cells. Moreover, the increased anticancer efficacy of dasatinib combined with CA-4 was further validated in a human HO-8910 ovarian cancer xenograft model in nude mice. Our study is the first to show that the combination of dasatinib with CA-4 could be a novel and promising therapeutic approach for the treatment of cancer.

In vitro anti-cancer activity of chamaejasmenin B and neochamaejasmin C isolated from the root of Stellera chamaejasme L.

AIM: To examine the anti-cancer effects of chamaejasmenin B and neochamaejasmin C, two biflavonones isolated from the root of Stellera chamaejasme L (known as the traditional Chinese herb Rui Xiang Lang Du) in vitro. METHODS: Human liver carcinoma cell lines (HepG2 and SMMC-7721), a human non-small cell lung cancer cell line (A549), human osteosarcoma cell lines (MG63, U2OS, and KHOS), a human colon cancer cell line (HCT-116) and a human cervical cancer cell line (HeLa) were used. The anti-proliferative effects of the compounds were measured using SRB cytotoxicity assay. DNA damage was detected by immunofluorescence and Western blotting. Apoptosis and cell cycle distribution were assessed using flow cytometry analysis. The expression of the related proteins was examined with Western blotting analysis. RESULTS: Both chamaejasmenin B and neochamaejasmin C exerted potent anti-proliferative effects in the 8 human solid tumor cell lines. Chamaejasmenin B (the IC(50) values ranged from 1.08 to 10.8 µmol/L) was slightly more potent than neochamaejasmin C (the IC(50) values ranged from 3.07 to 15.97 µmol/L). In the most sensitive A549 and KHOS cells, the mechanisms underlying the anti-proliferative effects were characterized. The two compounds induced prominent expression of the DNA damage marker γ-H2AX as well as apoptosis. Furthermore, treatment of the cells with the two compounds caused prominent G(0)/G(1) phase arrest. CONCLUSION: Chamaejasmenin B and neochamaejasmin C are potential anti-proliferative agents in 8 human solid tumor cell lines in vitro via inducing cell cycle arrest, apoptosis and DNA damage.

Wnt/ß-catenin signaling induces the aging of mesenchymal stem cells through promoting the ROS production.

Recent studies have demonstrated that the Wnt/ß-catenin signaling plays an important role in stem cell aging. However, the mechanisms of cell senescence induced by Wnt/ß-catenin signaling are still poorly understood. Our preliminary study has indicated that activated Wnt/ß-catenin signaling can induce MSC aging. In this study, we reported that the Wnt/ß-catenin signaling was a potent activator of reactive oxygen species (ROS) generation in MSCs. After scavenging ROS with N-acetylcysteine, Wnt/ß-catenin signaling-induced MSC aging was significantly attenuated and the DNA damage and the expression of p16(INK4A), p53, and p21 were reduced in MSCs. These results indicated that the Wnt/ß-catenin signaling could induce MSC aging through promoting the intracellular production of ROS, and ROS may be the main mediators of MSC aging induced by excessive activation of Wnt/ß-catenin signaling.

[Expression of B7-H4 in prostate cancer and its clinical significance].

OBJECTIVE: To investigate the expression of B7-H4 in prostate cancer tissue and the relationship between the expression and the clinicopathological features. METHODS: Immunohistochemical staining was used to detect the expression of B7-H4 in prostate cancer tissue. And the relationship between the expressions and pathology was evaluated. RESULTS: The B7-H4 was diffusely expressed in cytoplasm and/or membrane of the prostate cancer tissue; the expression was much higher than that in normal prostate tissue (P<0.05). The expression of B7-H4 in the prostate cancer tissue was higher in patients with higher tumor grade. CONCLUSION: B7-H4 may be used as an new indicator for the diagnosis and prognosis of prostate cancer and a novel target for immunotherapy.

[Effects of Sema3A derived from tumor cells on functions of dendritic cells].

OBJECTIVE: To investigate the effects of tumor cell-derived Sema3A on the immunological functions of murine dendritic cells (DCs). METHODS: Lung adenocarcinoma A549 cells were transfected with small interference RNA, Si-Sema and Si-mut, and the interference efficiency was determined by real-time PCR and Western-blot. The concentrated supernatants from cultured tumor cells, Si-Sema and Si-mut-infected tumor cells were subjected to DCs respectively. The immunophenotypes of DCs were analyzed by flow cytometry, the production of IL-12P70 and the ability of DCs to stimulate DO11. 10 T cells secreting IFN-gamma and IL-2 were detected by enzyme linked immunosorbent assay (ELISA). RESULTS: Knockdown with Si-Sema3A significantly decreased the secretion of Sema3A by A549 cells in comparison with the Si-mut cells. DCs exposed to supernatants from Si-Sema cells showed elevated levels of MHC, CD40 and CD80, more production of IL-12P70, and enhanced capability of activating antigen-specific T cells, as evidenced by the remarkably increased levels of IFN-gamma and IL-2. CONCLUSION: A549 cells secrete Sema3A to inhibit the maturation and functions of DCs, which might be associated with the unidentified mechanism of immune evasion by tumor cells.

[Construction and identification of recombinant adenoviral vector encoding B7-H4 gene].

OBJECTIVE: To construct the recombinant adenovirus containing B7-H4 gene with AdEasy XL system and to identify its biological activities. METHODS: The full-length mouse B7-H4 gene was amplified by RT-PCR from C57 mouse lung and put into T vector, then verified by sequencing. Digested with Xhol I and EcoR V the B7-H4 gene was inserted into pshuttle-CMW(PSC). Pme I linearized shuttle plasmid was transformed into E.coli BJ5183-AD-1 to obtain the recombinant adenoviral plasmid pAd-mB7-H4 by efficient homologous recombination. Then the recombinant adenovirus-mB7-H4/Ad was obtained by packaging Pac I linearized in D-293 cells. The mRNA and protein expression of B7-H4 in mB7-H4/Ad infected AD-293 cells were detected by RT-PCR and Western blot, respectively. mB7-H4/Ad was used to infect L929 cells, the bioactivity of expressed B7-H4 in stimulation of T lymphocytes proliferation and cytokine production were tested. RESULTS: The full-length of mB7-H4 was cloned from mouse lung tissue cDNA and verified by sequencing. The recombinant plasmid pAd-m B7-H4 was successfully generated by homologous recombination, and the primary mB7-H4/Ad was obtained by packaging pAd-B7-H4 in AD-293 cells. Compared with the negative control, L929 cells infected with mB7-H4/Ad effectively inhibited the proliferation of T lymphocytes and cytokines production. CONCLUSION: The bioactive recombinant adenovirus mB7-H4/Ad has been successfully constructed.

[Construction and expression of recombinant adenovirus containing human thymic stromal lymphopoietin gene].

AIM: To construct and express recombinant adenovirus bearing human thymic stromal lymphopoietin (TSLP) gene. METHODS: TSLP gene amplified from human fetal lung cells was first cloned into eukaryotic expression vector pcDNA3.1, and then subcloned into shuttle vector pShuttle. The resultant plasmid was subsequently cotransformed into E. coli BJ5183 cells with adenoviral backbone plasmid pAdEasy-1. The recombinant adenovirus plasmid containing TSLP was digested with Pac I and transfected into HEK293 cells to package recombinant adenovirus particles. The TSLP gene of the recombinant virus was detected by PCR, and its expression was analyzed by Western blot. RESULTS: Recombinant adenovirus vector bearing human TSLP gene was constructed by homologous recombination in E.coli, and recombinant adenovirus was obtained by transfecting HEK293 cells with this infectious DNA. PCR test indicated that TSLP gene was successfully integrated into the adenoviral genome, and the titer of the recombinant Ad reached 1 x 10(11) pfu/L. Meanwhile, expression of TSLP in the infected Hela cells was confirmed by Western blot. CONCLUSION: The construction of recombinant adenovirus bearing human TSLP gene and its expression mediated by this adenovirus pave a foundation for the study on the biological function of this novel cytokine.

[Effect of Triptolide on TNFalpha-induced activation of NF-kappaB and expression of COX-2 and iNOS in human rheumatoid arthritis synovial fibroblasts].

OBJECTIVE: To explore the effects of Triptolide (TP) on TNFalpha-induced cell proliferation and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their inducing products PGE2, NO in human rheumatoid arthritis synovial fibroblasts (RASF). METHODS: Fibroblasts (RASF) were obtained from synovial tissue of patients with RA and were cultured in vitro. RASF were stimulated with TNFalpha(20 microg/L) in the presence or absence of TP(0 - 100 microg/L) for 20 h. The RASF proliferation was determined by (3)H-TdR incorporation, and the productions of PGE2 and NO in culture supernatants of RASF were detected with competitive ELISA and enzyme reduction of nitrate. Expressions of COX-2 and iNOS mRNA in RASF were analyzed by semi-quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western-blot method and cellular enzyme immunoassay in synovial fibroblasts. NF-kappaB activity in whole-cell extract of RASF was also measured by an ELISA-based method. RESULTS: TP (>20 microg/L) down-regulated markedly TNFalpha-induced COX-2 and iNOS mRNA and protein expression, and their inducing products PGE2 and NO of synovial fibroblasts. This effect was positively correlated with TP concentrations. NF-kappaB activity in TNFalpha-stimulated synovial cells was suppressed profoundly by TP treatment (IC(50) approximately 35microg/L). The activity of NF-kappaB was correlated with the levels of COX-2 and iNOS expression in TNFalpha-stimulated RASF. No change was observed in proliferation of synovial cells after treatment of TP. CONCLUSION: TP could significantly down-regulate TNFalpha-induced COX-2, iNOS expression and production of PGE2, NO in human RASF, which is associated with the suppression of NF-kappaB activity.

[Enhancement by FK506 of triptolide-induced inhibition of expression of COX-2 and iNOS in human rheumatoid arthritis synovial fibroblasts].

To explore the effects of FK506 on the inhibition by triptolide (TP) of cell proliferation and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their inducing products PGE2, NO in human rheumatoid arthritis synovial fibroblasts (RASF), and to study the mechanisms of combination of FK506 and TP in RA therapy, RASF used in the experiments were obtained from synovial tissue of patients with RA and were cultured. RASF were pretreated with FK506(10-1000 nmol/L)for 2 h, then the cells were stimulated with TNF alpha(20 microg/L) in the presence or absence of TP (10 microg/L). The RASF proliferation was determined by [(3)H]-TdR incorporation, and the productions of PGE2 and NO in culture supernatants of RASF were detected with competitive ELISA and enzyme reduction of nitrate. Expression of COX-2 and iNOS mRNA in RASF were analyzed by semi quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western blot method and cellular enzyme immunoassay in synovial fibroblasts. NF-kappa B activity in whole-cell extract of RASF was also measured by an ELISA-based method. Results showed that neither FK506 nor TP at lower concentration (10 microg/L) alone affected TNF alpha-induced COX-2, iNOS expression and production of PGE2, NO in synovial cells. Combined treatment of FK506 and a lower concentration of TP (10 microg/L) down-regulated COX-2 and iNOS mRNA and protein expression, and their inducing products PGE2 and NO of synovial fibroblasts. This effect was positively correlated with FK506 concentrations (10-1000 nmol/L). NF-kappa B activity in TNF alpha-stimulated synovial cells was suppressed more profoundly by FK506 plus TP (10 microg/L) treatment than those with TP (10 microg/L) alone. No change was observed in inhibition of proliferation of synovial cells after combined treatment of FK506 and TP. In conclusion, FK506 enhanced TP-mediated down-regulation of COX-2, iNOS and their inducing products PGE2, NO in human RASF by suppressing the activity of NF-kappa B.