[Research progress of hepatocyte transplantation treatment for alpha-1 antitrypsin deficiency].

Alpha-1 antitrypsin deficiency is an autosomal codominant genetic disease characterized by low levels of alpha-1 antitrypsin in the blood. Clinically, in young patients, it mainly manifests as emphysema, acute/chronic liver injury and liver cancer. The treatment methods include symptomatic treatment and alpha -1 antitrypsin supplementation. However, the existing treatment cannot prevent the liver fibrosis progression. At present, more than ten cases of the disease have been reported in China, but the understanding of this disease is still indecisive. Moreover, there exists no biotherapy drug for this disorder. This article introduces the research progress of hepatocyte transplantation treatment for this disorder.

[The effect of human islet amyloid polypeptide on autophagy in murine INS-1 cells and potential mechanisms].

Objective: The aims of the study were to investigate the effects of human islet amyloid polypeptide (hIAPP) on autophagy in INS-1 cells and its underlying mechanism, and to explore the role of autophagy in hIAPP-induced cytotoxicity and oxidative stress. Methods: INS-1 cells were treated with hIAPP (10 µmol/L) for 24 h in the presence or absence of N-acetyl-L-cysteine (NAC), compound C, 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside (AICAR) and 3-methyladenine (3-MA), respectively. Transmission electron microscopy was used to observe the number of autophagosome in cells. Cell viability was determined by methyl thiazolyl tetrazolium (MTT) test. 2',7'-dichlorofluorescin diacetate (DCFH-DA) assay was used to measure the relative levels of reactive oxygen species (ROS). Western blot was used to detect expression of adenosine monophosphate-activated protein kinase (AMPK) and autophagic markers p62 and microtubule associated protein 1 light chain3 (LC3). Results: Treatment of INS-1 cells with hIAPP resulted in a significant increase in the number of autophagosomes and the expression of LC3-Ⅱ/LC3-Ⅰ (both P<0.05). Meanwhile, treatment of INS-1 cells with hIAPP enhanced the level of ROS to 1.76 times of control cells (P<0.01). Co-treatment with NAC, an antioxidant, inhibited hIAPP-induced ROS generation, and the expression of LC3-Ⅱ/LC3-Ⅰ and p-AMPK in the INS-1 cells (all P<0.05). Pretreatment of INS-1 cells with AMPK inhibitor compound C suppressed hIAPP and AICAR, an activator of AMPK, induced expression of LC3-Ⅱ/LC3-Ⅰ and p-AMPK (all P<0.05). Autophagic inhibitor 3-MA and compound C aggravated the hIAPP-induced cell death and ROS generation in INS-1 cells (All P<0.05). The cytotoxic effects of hIAPP were significantly attenuated by co-treatment with AICAR (P<0.05). Conclusion: Autophagy may act as an adaptive mechanism to alleviate hIAPP-induced oxidative damage and toxicity in INS-1 cells.

Ordering of mutations in acute myeloid leukemia with partial tandem duplication of MLL (MLL-PTD).

Partial tandem duplication of MLL (MLL-PTD) characterizes acute myeloid leukemia (AML) patients often with a poor prognosis. To understand the order of occurrence of MLL-PTD in relation to other major AML mutations and to identify novel mutations that may be present in this unique AML molecular subtype, exome and targeted sequencing was performed on 85 MLL-PTD AML samples using HiSeq-2000. Genes involved in the cohesin complex (STAG2), a splicing factor (U2AF1) and a poorly studied gene, MGA were recurrently mutated, whereas NPM1, one of the most frequently mutated AML gene, was not mutated in MLL-PTD patients. Interestingly, clonality analysis suggests that IDH2/1, DNMT3A, U2AF1 and TET2 mutations are clonal and occur early, and MLL-PTD likely arises after these initial mutations. Conversely, proliferative mutations (FLT3, RAS), typically appear later, are largely subclonal and tend to be unstable. This study provides important insights for understanding the relative importance of different mutations for defining a targeted therapeutic strategy for MLL-PTD AML patients.

LNK (SH2B3): paradoxical effects in ovarian cancer.

LNK (SH2B3) is an adaptor protein studied extensively in normal and malignant hematopoietic cells. In these cells, it downregulates activated tyrosine kinases at the cell surface resulting in an antiproliferative effect. To date, no studies have examined activities of LNK in solid tumors. In this study, we found by in silico analysis and staining tissue arrays that the levels of LNK expression were elevated in high-grade ovarian cancer. To test the functional importance of this observation, LNK was either overexpressed or silenced in several ovarian cancer cell lines. Remarkably, overexpression of LNK rendered the cells resistant to death induced by either serum starvation or nutrient deprivation, and generated larger tumors using a murine xenograft model. In contrast, silencing of LNK decreased ovarian cancer cell growth in vitro and in vivo. Western blot studies indicated that overexpression of LNK upregulated and extended the transduction of the mitogenic signal, whereas silencing of LNK produced the opposite effects. Furthermore, forced expression of LNK reduced cell size, inhibited cell migration and markedly enhanced cell adhesion. Liquid chromatography-mass spectroscopy identified 14-3-3 as one of the LNK-binding partners. Our results suggest that in contrast to the findings in hematologic malignancies, the adaptor protein LNK acts as a positive signal transduction modulator in ovarian cancers.

Cloning and mutation analysis of the human potassium channel KCNQ2 gene promoter.

Benign familial neonatal convulsions (BFNC) have been previously found to be associated with mutations within the coding region of KCNQ2. We have now cloned and analyzed the promoter region of the human KCNQ2 gene. 5'-RACE identified a transcription start site (TSS) located 200 bp upstream of the ATG start codon. The TSS is located close to a repetitive region containing seven copies of a degenerate 42-mer repeat. Several different luciferase (LUC) reporter plas- mids containing fragments from the KCNQ2 5'-flanking region were constructed and expressed in NT2N and SH-SY5Y cell lines. A core promoter region was found to be located between bp 20 and bp 74 upstream of the TSS. Neither the promoter region nor the repetitive region showed any mutations in 13 index patients from unrelated BFNC families.