Long-Term Survival Outcome Between Living Donor and Deceased Donor Liver Transplant for Hepatocellular Carcinoma: Intention-to-Treat and Propensity Score Matching Analyses.

BACKGROUND: Previous studies comparing outcomes of hepatocellular carcinoma (HCC) patients after living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) showed conflicting results, and most studies measured survival outcomes from the time of liver transplantation (LT). METHOD: This retrospective study was aimed to evaluate the long-term outcomes of HCC patients listed for LT using intention-to-treat (ITT) and propensity score matching (PSM) analyses. Clinicopathological data were retrieved from a prospectively collected database. RESULTS: From 1995 to 2014, 375 HCC patients were listed for LT. ITT-LDLT group had 188 patients, whereas ITT-DDLT group had 187 patients. Twenty-seven patients (14.4%) and 122 patients (65.2%) were delisted from LDLT and DDLT waitlist, respectively. The 1-, 3- and 5-year overall survival rates were significantly better in ITT-LDLT group than ITT-DDLT group (94.1 vs. 77.5%, 81.4 vs. 48.7% and 75.9 vs. 40.8%). High alphafetoprotein (AFP) and ITT-DDLT treatment arm were independent poor prognostic factors affecting overall survival. LDLT group (n = 161) had more young patients, poorer liver function, higher AFP, more tumors outside Milan/UCSF criteria, when compared with DDLT group (n = 85). After PSM, the 1-, 3- and 5-year overall (95.4 vs. 98.5%, 80.0 vs. 92.3% and 73.4 vs. 84.4%) and recurrence-free (87.7% vs. 90.8%, 76.9% vs. 83.1% and 72.2% vs. 81.5%) survival rates were comparable between the matched LDLT and the matched DDLT group, respectively. CONCLUSION: Survival benefit of LDLT was observed for HCC patients with ITT analysis. Despite a more advanced tumor stage, overall and recurrence-free survival rates were comparable between LDLT and DDLT using PSM analysis.

Histone acetyltransferase and protein kinase activities copurify with a putative Xenopus RNA polymerase I holoenzyme self-sufficient for promoter-dependent transcription.

Mounting evidence suggests that eukaryotic RNA polymerases preassociate with multiple transcription factors in the absence of DNA, forming RNA polymerase holoenzyme complexes. We have purified an apparent RNA polymerase I (Pol I) holoenzyme from Xenopus laevis cells by sequential chromatography on five columns: DEAE-Sepharose, Biorex 70, Sephacryl S300, Mono Q, and DNA-cellulose. Single fractions from every column programmed accurate promoter-dependent transcription. Upon gel filtration chromatography, the Pol I holoenzyme elutes at a position overlapping the peak of Blue Dextran, suggesting a molecular mass in the range of approximately 2 MDa. Consistent with its large mass, Coomassie blue-stained sodium dodecyl sulfate-polyacrylamide gels reveal approximately 55 proteins in fractions purified to near homogeneity. Western blotting shows that TATA-binding protein precisely copurifies with holoenzyme activity, whereas the abundant Pol I transactivator upstream binding factor does not. Also copurifying with the holoenzyme are casein kinase II and a histone acetyltransferase activity with a substrate preference for histone H3. These results extend to Pol I the suggestion that signal transduction and chromatin-modifying activities are associated with eukaryotic RNA polymerases.

Hyper-negative template DNA supercoiling during transcription of the tetracycline-resistance gene in topA mutants is largely constrained in vivo.

The excess linking deficit of plasmid DNA from topoisomerase I-defective bacteria (topA mutants) results mainly from transcription and is commonly ascribed to unbalanced relaxation of transcription-induced twin-supercoiled domains. This defect is aggravated in genes for membrane-binding proteins (such as the tet gene) where anchoring of the transcription complex to the bacterial membrane is thought to enhance twin-domain partitioning. Thus, it is often assumed that the 'hyper-negative' linking difference of plasmid DNA from topA mutants reflects unconstrained, hyper-negative DNA supercoiling inside the cell. We tested the validity of this assumption in the present study. A DNA sequence that undergoes a gradual B to Z transition under increasing negative superhelical tension was used as a sensor of unconstrained negative supercoiling. Z-DNA formation was probed at a site upstream from the inducible pTac promoter fused either to the tet gene or to the gene for cytosolic chloramphenicol acetyl transferase (cat). Although plasmid DNA linking deficit increased more extensively in topA mutants following tet activation than following cat activation, no significant differences were observed in the extents to which the B to Z DNA transition is stimulated in the two cases. We infer that the excess linking deficit of the tet-containing plasmid DNA reflects constrained negative DNA supercoiling inside the cell.

The size of the topological domain modulates the B-Z transition of a (TG)n containing repeat.

Under negative superhelical stress, long (TG)n containing repeats experience a stepwise multiple B-Z transitions. We have investigated the effect of the plasmid size on this transitional behavior. A 66-bp (TG)n containing repeat from the 5'-untranscribed region of mouse ribosomal DNA was inserted in a 3-kb, a 6.5-kb and a 12.5-kb plasmids and its supercoil-driven B-Z transition was followed by OsO4 probing of topoisomer-populations. Our results show a clear correlation between the size of the topological domain and the extent of the region that converts cooperatively into Z-DNA at the initial transition.

Gradual and oriented B-Z transition in 5'-untranscribed region of mouse ribosomal DNA.

The structural transition of an alternating purine-pyrimidine sequence (CG)5(TG)28) from the 5'-untranscribed region of the mouse ribosomal DNA was analyzed by two-dimensional gel electrophoresis and chemical probes. The repeat undergoes a supercoil-dependent gradual and oriented B-Z transition. At a threshold level of negative supercoiling, a limited region of the repeat encompassing the (CG)5 motif converts cooperatively into Z-DNA. As the superhelical stress increases, the Z-structure propagates along the remaining part of the repeat by successive transitions until the full-length sequence is converted. By in situ OsO4 probing experiments, we show also that this (TG)n-containing repeat adopts the Z-structure in Escherichia coli.