While transcription as regulated by histones and their post-translational modifications has been well described, the function of histone variants in this process remains poorly characterized. Potentially important insight into this process pertain to the frequently occurring mutations of H3.3, leading to G34 substitutions in childhood glioblastoma and giant cell tumor of the bone (GCTB). In this study, we have established primary cell lines from GCTB patients and used them to uncover the influence of H3.3 G34W substitutions on cellular growth behavior, gene expression, and chromatin compaction. Primary cell lines with H3.3 G34W showed increased colony formation, infiltration and proliferation, known hallmarks of tumor development. Isogenic cell lines with H3.3 G34W recapitulated the increased proliferation observed in primary cells. Transcriptomic analysis of primary cells and tumor biopsies revealed slightly more downregulated gene expression, perhaps by increased chromatin compaction. We identified components related to splicing, most prominently hnRNPs, by immunoprecipitation and mass spectrometry that specifically interact with H3.3 G34W in the isogenic cell lines. RNA-sequencing analysis and hybridization-based validations further enforced splicing aberrations. Our data uncover a role for H3.3 in RNA processing and chromatin modulation that is blocked by the G34W substitution, potentially driving the tumorigenic process in GCTB.

BackgroundOvarian cancer is one of the major causes of death among females in worldwide. Cisplatin is a primary anti-cancer drug against ovarian cancer, but the recurrent tumors after treatment frequently show acquired chemoresistance. Extract of Scutellaria baicalensis (SbE) has been reported to have functional compounds including baicalin, which has anti-cancer effects. However, the anti-cancer effects of SbE in ovarian cancer and its underlying mechanisms are elusive.MethodsWe investigated that the effects of SbE and/or cisplatin on cell death in the cisplatin sensitive ovarian cancer cell line A2780 (CSC) and the counterpart cell line that has cisplatin resistance (CRC). Molecular mechanisms of the effects, focusing on apoptosis and autophagy, were examined.ResultsTreatment of cisplatin or SbE reduced cell viability significantly in CSC and too much lesser extent in CRC. Cisplatin-induced cell death in CSC was mediated by p53-induced apoptosis acompanied by expresson of damage-regulated autophagy modulator (DRAM). In CRC, decreased DRAM expression (p < 0.01) hindered p21-mediated cell death and contributed to cisplatin resistance. Treatment of SbE also induced cell death in CSC by p53-dependent apoptosis, not in CRC. Autophagy was not induced by neither cisplatin nor SbE. Intriguingly, the combinational treatment of SbE and cisplatin significantly decreased cell viability in CRC. The cell death was mediated by autophagy with increased expression of Atg5 and Atg12 (p < 0.05), rather than p53-dependent pathway with repressed expression of p21 (p < 0.001) through HDAC1 activation.ConclusionsThe combined treatment of SbE with cisplatin was effective in CRC, leading to cell death via Beclin1-independent autophagy, suggesting that SbE treatment in combination with cisplatin has a potential as a chemotherapeutic agent in cisplatin-resistant ovarian cancer.

Ovarian cancer is the gynecological malignancy with the poorest prognosis, in part due to its high incidence of recurrence. Platinum agents are widely used as a first-line treatment against ovarian cancer. Recurrent tumors, however, frequently demonstrate acquired chemo-resistance to platinum agent toxicity. To improve chemo-sensitivity, combination chemotherapy regimens have been investigated. This study examined anti-tumor effects and molecular mechanisms of cytotoxicity of Oldenlandia diffusa (OD) extracts on ovarian cancer cells, in particular, cells resistant to cisplatin. Six ovarian cancer cells including A2780 and cisplatin-resistant A2780 (A2780cis) as representative cell models were used. OD was extracted with water (WOD) or 50% methanol (MOD). MOD significantly induced cell death in both cisplatin-sensitive cells and cisplatin-resistant cells. The combination treatment of MOD with cisplatin reduced viability in A2780cis cells more effectively than treatment with cisplatin alone. MOD in A2780cis cells resulted in downregulation of the epigenetic modulator KDM1B and the DNA repair gene DCLRE1B. Transcriptional suppression of KDM1B and DCLRE1B induced cisplatin sensitivity. Knockdown of KDM1B led to downregulation of DCLRE1B expression, suggesting that DCLRE1B was a KDM1B downstream target. Taken together, OD extract effectively promoted cell death in cisplatin-resistant ovarian cancer cells under cisplatin treatment through modulating KDM1B and DCLRE1B.

The efficiency of biochars (BCs) derived from paper mill sludge (PM-BC), distillery sludge (DS-BC), and pruned branches from roadside trees (PB-BC) for immobilization of selected heavy metals (Cd and Zn) in agricultural soils was examined in the current study. This examination was conducted in order to elucidate whether the recycling of organic wastes could be used as a management option for metal-contaminated agricultural soils. Biochars were applied to contaminated upland soil exceeding the guideline values for Cd (4 mg kg −1 ) and Zn (300 mg kg −1 ) in Korea. Both the incubation study and the pot trial with lettuce cultivation were carried out using soil-BCs mixtures at 0, 1, 2, and 5 % (w/w). From the incubation study, it appears that BCs incorporated into the soil induces an increasing soil pH and a significant decline (Cd 36~100 %; Zn 54~100 %) in the phytoavailable metal pool examined by 1 M NH 4 NO 3 extraction. The PM-BC was most effective in the reduction of Cd and Zn phytoavailability, due to a significantly higher pH and surface area than the DS-BC and PB-BC. Similar results were observed in the pot trial, where the uptake of heavy metals by lettuce greatly declined with PM-BC incorporation (Cd 26~71 %; Zn 28~45 %). PM-BC enhanced the lettuce growth performance evidenced by the highest yield of lettuce being observed with PM-BC-treated soils at 5 %. This was attributed to retardation of the metal toxic effect induced by a decrease in Cd accumulation, while the increased nutrient elements originated from PM-BC. This present study indicates that paper mill sludge is a great candidate for biochar production that can be utilized as a soil amendment for metalcontaminated agricultural soils.

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