Objective evaluation of the degree of pigmentation in human induced pluripotent stem cell-derived RPE.

Purpose: For the transplantation of human induced pluripotent stem cell-derived retinal pigment epithelium (hiPSC-RPE), determination of the maturation status of these cells is essential, and the degree of pigmentation (dPG) can serve as a good indicator of this status. The aim of this study was to establish a method of objectively and quantitatively evaluating the dPG of hiPSC-RPE.

Methods: Two observers determined the dPG subjectively by observing recorded images of hiPSC-RPE as follows: the dPG of a single cell was classified into three different pigmentation stages, and the overall dPG was compared between two cell groups to identify the group with the higher dPG.

Breast cancers with high DSS1 expression that potentially maintains BRCA2 stability have poor prognosis in the relapse-free survival.

Background: Genetic BRCA2 insufficiency is associated with breast cancer development; however, in sporadic breast cancer cases, high BRCA2 expression is paradoxically correlated with poor prognosis. Because DSS1, a mammalian component of the transcription/RNA export complex, is known to stabilize BRCA2, we investigated how the expression of DSS1 is associated with clinical parameters in breast cancers.

Methods: DSS1 mRNA and p53 protein were examined by RT-PCR and immunohistochemical staining of breast cancer specimens to classify DSS1(high) and DSS1(low) or p53(high) and p53(low) groups.

Selective cell death of p53-insufficient cancer cells is induced by knockdown of the mRNA export molecule GANP.

Cancer cells often contain p53 abnormalities that impair cell-cycle checkpoint progression and cause resistance to various anti-cancer treatments. DNA damage occurs at actively transcribed genes during G1-phase in yeast cells that have a deficient mRNA export capacity. Here, we show that germinal center-associated nuclear protein (GANP), a homologue of yeast Sac3 that is involved in mRNA export, is indispensable for ensuring the stability of human genomic DNA and that GANP knockdown causes apoptosis and necrosis of p53-insufficient cancer cells.

Clostridium perfringens iota-toxin b induces rapid cell necrosis.

Clostridium perfringens iota-toxin is a binary toxin composed of an enzyme component (Ia) and a binding component (Ib). Each component alone lacks toxic activity, but together they produce cytotoxic effects. We examined the cytotoxicity of iota-toxin Ib in eight cell lines.

Dihydro-alpha-lipoic acid has more potent cytotoxicity than alpha-lipoic acid.

Alpha-lipoic acid has been shown to possess cancer-cell-killing activity via activation of the apoptosis pathway. In this study, the cytotoxic activities of alpha-lipoic and dihydro-alpha-lipoic acid were compared in HL-60 cells. The cell-killing activity of dihydro-alpha-lipoic acid was higher than that of alpha-lipoic acid.

Three distinct stages of apoptotic nuclear condensation revealed by time-lapse imaging, biochemical and electron microscopy analysis of cell-free apoptosis.

During apoptotic execution, chromatin undergoes a phase change from a heterogeneous, genetically active network to an inert highly condensed form that is fragmented and packaged into apoptotic bodies. We have previously used a cell-free system to examine the roles of caspases or other proteases in apoptotic chromatin condensation and nuclear disassembly. But so far, the role of DNase activity or ATP hydrolysis in this system has not yet been elucidated.