I read with interest the article by Yin et al.1 on differentiation therapy of hepatocellular carcinoma (HCC). The study by Yin et al.1 showed that a differentiation therapy with hepatocyte nuclear factor 4 alpha induced the differentiation of hepatoma cells into hepatocytes by the dramatic decrease of gene expression of four transcription factors (Oct3/4 [octamer 3/octamer 4], Sox2 [sex-determining region Y box 2], Klf4 [Kruppel-like factor 4], and c-Myc) which are known reprogramming factors.2-4 The results by Yin et al.1 may be helpful in order to understand the differences between human induced pluripotent stem (iPS) cells and human hepatoma cells or to develop novel HCC therapy. Therefore, first, I reviewed the gene expression of the four factors between human iPS cells established from healthy humans by using the four factors2, 3 and human hepatoma cells.1 As a result, the gene expression levels of c-Myc and Klf4 were lower than that of Oct3/4 and Sox2 in human iPS cells.2, 3 However, the gene expression levels of c-Myc and Klf4 were higher than that of Oct3/4 and Sox2 in Hep3B and HepG2 human hepatoma cell lines.1 On the other hand, the relative ratio of Oct3/4 and Sox2 was 1:1 in human iPS cells derived from neonatal foreskin fibroblasts, adult dermal fibroblasts, and CD 34+ mobilized human peripheral blood cells, generally.2, 3 However, for example, the relative ratio of Oct3/4 and Sox2 was 4:1 in Hep3B or HepG2 cells, generally.1 Thus, the gene expression levels of the four factors or the relative ratio of Oct3/4 and Sox2 in human hepatoma cells were inappropriate in comparison with the cases of human iPS cells. Therefore, I found that the differences between human iPS cells and human hepatoma cells can be explained by the gene expression levels of the four factors or the relative ratio of Oct3/4 and Sox2. On the other hand, a recent study showed that gene expression for the four factors in human cancers was overexpressed compared to normal tissues and the expression levels were associated with tumor progression or bad prognosis.5 Furthermore, after undergoing the differentiation therapy of Yin et al.,1 the gene expression levels of c-Myc and Klf4 became lower than that of Oct3/4 and Sox2. This was comparable to the cases of human iPS cells. Therefore, if the gene expression levels for the four factors in human hepatoma cells can be decreased and can be compared with the levels in human normal cells and/or tissues, the efficacy of human HCC therapy could be increasingly improved. Furthermore, the gene expression levels for the four factors may serve as a basis for detecting and/or monitoring the effect of potential therapeutic agents on human HCC. In conclusion, the four factors are not only reprogramming factors of human somatic cells but also novel targets for human HCC therapy. I am grateful to Ms. Satoko Iioka for helpful discussions. Hisashi Moriguchi M.P.H., Ph.D.*, * Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
The results of J Cinatl and colleagues1Cinatl J Morgenstern B Bauer G Chandra P Rabenau H Doerr HW Treatment of SARS with human interferons.Lancet. 2003; 362: 293-294Summary Full Text Full Text PDF PubMed Scopus (396) Google Scholar show that interferon beta is effective against SARS-CoV—a membrane-enclosed RNA virus2Drosten C Gunther S Preiser W et al.Identification of a novel coronavirus in patients with severe acute respiratory syndrome.N Engl J Med. 2003; 348: 1967-1976Crossref PubMed Scopus (3682) Google Scholar—in vitro, when used either alone or in combination with other antiviral drugs. Their results concur with our beliefs that interferon, with its broad-spectrum antiviral activity against RNA viruses, might be useful in the treatment of SARS, either as a monotherapy or plus ribavirin. However, the findings of Ozes and co-workers3Ozes ON Reiter Z Klein S Blatt LM Taylor MW A comparison of interferon-Con1 with natural recombinant interferons-alpha: antiviral, antiproliferative, and natural killer-inducing activities.J Interferon Res. 1992; 12: 55-59Crossref PubMed Scopus (118) Google Scholar show that the specific activity (antiviral units/mg) of recombinant human interferon-consensus 1 (IFN-Con1) was ten-fold higher than that of interferon alfa-2a and interferon alfa-2b in vitro. Furthermore, IFN-Con1 increases the ability of or induces natural killer cells to kill target cells to a greater extent than does interferon alfa.3Ozes ON Reiter Z Klein S Blatt LM Taylor MW A comparison of interferon-Con1 with natural recombinant interferons-alpha: antiviral, antiproliferative, and natural killer-inducing activities.J Interferon Res. 1992; 12: 55-59Crossref PubMed Scopus (118) Google Scholar Therefore, we suggest that IFN-Con1 and IFN-Con1 plus ribavirin are assessed as potential antiviral drugs for the treatment of SARS with the method used by Cinatl and colleagues.
Precise control of differentiation processes of pluripotent stem cell is key component for realization of regenerative medicine. Electrical stimulation is one of the promising techniques, particularly for regulation of neuronal regeneration. In the present study, we developed substrates with embedded electrodes, which allowed ensemble electrical stimulation of embryoid bodies (EBs) of stem cells. Microcavity-array patterns were fabricated on substrates with embedded electrodes using standard photo-lithography. Uniform-size EBs of P19 cells were prepared, inserted one by one in each microcavity, and electrical stimulation was applied through substrate electrodes. Stimulus-induced intracellular calcium transients were successfully monitored by fluorescence imaging. The results suggested that this method would be useful for applying precisely-controlled electrical stimulation to a large number of EBs of stem cells.
4069 Background: The incidence of hepatocellular carcinoma (HCC) is increasing because of the dissemination of hepatitis C virus (HCV) infection worldwide. Therefore, an appropriate method to predict HCV-related HCC is needed. Methods: To investigate an association between the mutation in the PKR-binding domain (PKR-bd: NS5A 2209–2274) of the HCV-NS5A protein and the incidence of HCC, sequential data of HCV-1b genomic regions were obtained from available published data (n=82) by the MEDLINE data base and our clinical data (n=125), in which the regions were amplified and directly sequenced from serum samples obtained from 207 patients with chronic liver diseases [HCV-1b infection or HCV-1b-related cirrhosis], 80 with and 127 without HCC. None of them had received interferon therapies. The PKR-bd mutant was defined to have more than 4 amino acid substitutions, the PKR-bd intermediate had 1 to 3 amino acid substitutions, and the PKR-bd wild had no amino acid substitutions. We compared categorical data by the chi-square test. P < 0.05 was considered significant. Results: The incidence of HCV-1b-related HCC in the PKR-bd wild, the PKR-bd intermediate and the PKR-bd mutant was 6/26 (23.1 %), 39/119 (32.8 %) and 35/62 (56.5 %), respectively. Therefore, the incidence of HCV-1b-related HCC was significantly higher in the PKR-bd mutant than the others (mutant vs wild, p=0.004: mutant vs intermediate, p=0.002). Especially, the relative risk for HCV-1b-related HCC in the PKR-bd mutant was 2.45 (95 % CI: 1.17–5.10) compared to the PKR-bd wild. Conclusions: The risk of HCV-1b-related HCC can be predicted by the mutation in the PKR-bd. And, the PKR-bd mutant is super high risk group of HCV-1b-related HCC. No significant financial relationships to disclose.
Various methods for the direct reprogramming of human somatic cells have been developed. However, a therapeutic method to reprogram and eliminate human solid tumor cells has not been developed. Here we show a novel therapeutic method to reprogram and eliminate human solid tumor cells with chemicals. This therapeutic method may be applicable to various human solid tumor cells that express aldo-keto reductase family 1 member B10 (AKR1B10) and retinoid X receptors (RXRs).
We read with interest the article by Delang et al.1 They showed excellent antiviral effects for the combination of hepatitis C virus (HCV) polymerase or protease inhibitors with mevastatin or simvastatin in vitro.1 However, they did not use atorvastatin and pitavastatin in their study.1 According to our replicon system,2 atorvastatin or pitavastatin was more effective for HCV-1b infection among monotherapy of statins (Fig. 1). This result is also supported by an experimental study.3 For example, median effective concentration (EC50) value was 2.16, 1.57, 1.39, 0.90, and 0.45 μM in lovastatin, simvastatin, atorvastatin, fluvastatin, and pitavastatin, respectively.3 Therefore, pitavastatin possessed the strongest anti-HCV activity among the statins tested.3 Considering these facts, antiviral effects in HCV-1b infection for the combination of HCV polymerase or protease inhibitors with pitavastatin should be also considered in vitro. Efficacy of several drugs against HCV infection among monotherapy of statins. Vertical axis; Relative luciferase activity (% of control) horizontal axis; statins (μM), IFN (U/mL) ATV, atorvastatin; FLV, fluvastatin; IFN, interferon; PTV, pitavastatin; SMV, simvastatin. MTS; 5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazoly)-3-(4-sulfophenyl)tetra-zolium, inner salt). In addition, the toxicities for these combination therapies should be evaluated appropriately. As for this point, human induced pluripotent stem cells (iPSCs) can be efficiently induced to differentiate into hepatocyte-like cells.4 This suggest that human iPSCs derived from patients with HCV-1b infection can differentiate into hepatocyte-like cells. By using the patient-specific hepatocyte-like cells, the patient-specific toxicities for the abovementioned combination therapies for HCV-1b infection could be evaluated in the near future. In conclusion, we describe a method to effectively progress the translational research on novel combination therapies for HCV-1b infection. Acknowledgment: We are grateful to Dr. Naoya Sakamoto and other members of our laboratories for technical support. Furthermore, we are also grateful to Ms. Satoko Iioka for helpful discussions. We are grateful to Dr. Naoya Sakamoto and other members of our laboratories for technical support. Furthermore, we are also grateful to Ms. Satoko Iioka for helpful discussions. Hisashi Moriguchi* , Raymond T Chung , Chifumi Sato , * Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan, Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, Department of Analytical Health Science, Graduate School of Health Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
