Background:The anti-cancer activity and mechanisms of isorhapontigenin (ISO) have never been explored. Results: ISO exhibited an anti-cancer activity accompanied by apoptotic induction and XIAP down-regulation through attenuation of SP1 expression. Conclusion: ISO is an active anti-cancer compound by inducing apoptosis via down-regulation of SP1/XIAP pathway. Significance: Current studies identify a new promising active compound for therapy of human cancers with XIAP overexpression.
Cell migration is a dynamic process that is central to a variety of physiological functions as well as disease pathogenesis. The modulation of cell migration by p27 has been reported, but the exact mechanism(s) whereby p27 intersects with downstream effectors that control cell migration have not been elucidated. By systematically comparing p27+/+ MEFs with genetically ablated p27−/− MEFs using wound healing, transwell and time-lapse microscopic analyses, we provide direct evidence demonstrating that p27 inhibits both directional and random cell migration. Identical results were obtained with normal and cancer epithelial cells using complementary knockdown and overexpression approaches. Additional studies revealed that overexpression of manganese superoxide dismutase (MnSOD) and reduced intracellular oxidation played a key role in increased cell migration in p27-deficient cells. Furthermore, we identified signal transducer and activator of transcription 3 (STAT3) as the transcription factor responsible for p27-regulated MnSOD expression which was further mediated by ERKs/ATF1-dependent transactivation of CRE within the stat3 promoter. Collectively, our data strongly indicate that p27 plays a crucially negative role in cell migration by inhibiting MnSOD expression in a STAT-3 dependent manner.
Arsenic trioxide (AsO) is an old drug that has recently been reintroduced as a therapeutic agent for acute promyelocytic leukemia (APL). Although AsO is also applied to treat other types of cancer in vitro and in vivo, it has been reported that single agent AsO has poor efficacy against non-hematologic malignant cancers in clinical trials. Recently, a few reports have indicated that organic arsenic compounds can be a possible alternative for the treatment of AsO-resistant cancers. In this study, we aimed to investigate whether the organic arsenic compound phenylarsine oxide (PAO) has potent cytotoxic effects against human hepatocellular carcinoma (HCC) HepG2 cells. Our results showed that PAO not only had a potent inhibitory effect on the proliferation of HepG2 cells but also activated apoptosis-related proteins (e.g., caspase-3 and -9 and poly-ADP ribose polymerase) in a dose- and time-dependent manner. Furthermore, intracellular ROS were specifically accumulated in the mitochondria and endoplasmic reticulum (ER) after exposure to PAO, implying that they are the target organelles for PAO-induced cytotoxicity. Additionally, when the cells were pretreated with antioxidant N-acetylcysteine (NAC), apoptosis and ER-stress were attenuated significantly, suggesting that induction of apoptosis and cell death probably occurs through the ROS-mediated mitochondria and ER-stress dependent signaling pathways.
Pancreatic β-cell regeneration, the therapeutic expansion of β-cell number to reverse diabetes, is an important goal. Replication of differentiated insulin-producing cells is the major source of new β-cells in adult mice and juvenile humans. Nucleoside analogs such as BrdU, which are incorporated into DNA during S-phase, have been widely used to quantify β-cell proliferation. However, reports of β-cell nuclei labeling with both BrdU and γ-phosphorylated H2A histone family member X (γH2AX), a DNA damage marker, have raised questions about the fidelity of BrdU to label S-phase, especially during conditions when DNA damage is present. We performed experiments to clarify the causes of BrdU-γH2AX double labeling in mouse and human β-cells. BrdU-γH2AX colabeling is neither an age-related phenomenon nor limited to human β-cells. DNA damage suppressed BrdU labeling and BrdU-γH2AX colabeling. In dispersed islet cells, but not in intact islets or in vivo, pro-proliferative conditions promoted both BrdU and γH2AX labeling, which could indicate DNA damage, DNA replication stress, or cell cycle–related intrinsic H2AX phosphorylation. Strategies to increase β-cell number must not only tackle the difficult challenge of enticing a quiescent cell to enter the cell cycle, but also achieve safe completion of the cell division process.
Background and ObjectivesMedications for opioid use disorder (MOUD) reduce opioid use and overdose; however, MOUD clinical trials have used varying primary outcomes to document treatment success. We conducted a literature review to assess and critically examine the methodologies used in MOUD treatment studies.MethodsPublished studies in English that examined MOUD (buprenorphine, methadone, or extended‐release naltrexone) were included (N = 20). The methods and frequencies of measuring primary opioid outcomes, including urine drug tests (UDTs) and self‐report of opioid use were compared among studies.ResultsA total of 20 studies fit the inclusion criteria. Each study assessed opioid use; only 12 had opioid use as a primary outcome. Other primary outcomes included retention in treatment (N = 6), and two had other primary outcomes (death and opioid withdrawal symptoms). Opioid use was assessed through both self‐report and UDTs in 15 studies. Two studies did not use UDTs. Differences were found in the methods used for how opioid use, retention in treatment, self‐report of opioid use, and UDTs were measured.Discussion and ConclusionsThe different primary outcomes used and operational definitions in each study make comparisons between studies difficult. The use of both self‐report and UDTs for opioid use has several advantages, and if possible, researchers should use both measures.Scientific SignificanceThis is the first review critically examining outcome measures from MOUD treatment studies. Creating a standard for opioid treatment outcomes in MOUD studies will allow for generalizable results that can inform both researchers and clinicians to better care for those with OUD. (Am J Addict 2020;00:00–00)
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