[Construction of a Mouse Model for Myeloproliferative Neoplasms and an Evaluation System].

OBJECTIVE: To construct a myeloproliferative neoplasms (MPN) transplanted mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation, and establish a systematic evaluation system to verify the success of model construction. METHODS: The bone marrow c-kit+ cells of the mice were obtained by the following steps: The mice were killed by cervical dislocation, the femur, tibia and ilium were separated, and the bone marrow cells were collected. The c-kit+ cells were sorted after incubation with CD117 magnetic beads. The method of constructing mouse primary mutant cells is as follows: A gene mutation vector with a GFP tag was constructed by the retroviral system, and the retroviral vector was packaged into the Platinum-E cells to obtain the virus supernatant, and then used it to infect the c-kit+ cells of mice. The MPN mouse model was constructed as follows: the mouse primary c-kit+ cells containing the mutant genes were collected after infection, and then transplanted them via the tail vein into the female recipient mice of the same species which were irradiated with a lethal dose of gamma rays (8.0 Gy). The MPN mouse model was evaluated as follows: After transplantation, the peripheral blood of the mice was regularly collected from the tail vein to perform the complete blood count test, and the size of spleen and the degree of bone marrow fibrosis were estimated. RESULTS: The mouse c-kit+ cells with the mutant genes were successfully obtained from the bone marrow. MPN mouse model was successfully constructed: The peripheral blood cells of the MPN-transplanted mice carried exogenous implanted GFP-positive cells, and the white blood cells (WBC), platelet (PLT) and hematocrit (HCT) were all increased; the body weight loss, and the water and food intake were reduced in the transplanted mice; further pathological analysis showed that the transplanted mice displayed splenomegaly and bone marrow fibrosis. These results suggested that the MPN mouse model was successfully constructed. According to the common and different characteristics of the three MPN mouse model, a preliminary evaluation system for judging the success of MPN mouse model construction was summarized, which mainly included the following indicators, for example, the proportion of GFP-positive cells in the peripheral blood of mice; WBC, PLT and HCT; the degree of spleen enlargement and the bone marrow fibrosis. CONCLUSION: The MPN mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation is successfully established by retroviral system, which can provide an important experimental animal model for the research of MPN pathogenesis and drug-targeted therapy.

Inhibition of ITCH Suppresses Proliferation and Induces Apoptosis of Lung Cancer Cells.

BACKGROUND/AIMS: The E3 ubiquitin ligase ITCH plays an important role in invasive and metastatic cancers. However, the role of ITCH in the progression of lung cancer has not been fully described. METHODS: Real-time PCR was used to detect the expression of ITCH mRNA in the tumor tissues and paracarcinoma tissues from 32 patients with lung cancer. SiRNA was used to inhibit the expression of ITCH in two lung cancer cell lines, H1975 and Calu3 and the cell proliferation and apoptosis were measured by MTT and flow cytometric assay. In addition, to further investigate whether ITCH affected the apoptosis of cancer cells and its underlying mechanisms, the expression of important markers of apoptosis and invasion in lung cancer cells were detected by Western blot. RESULTS: The study showed significant increments in the expression of ITCH in lung cancer tissues (p< 0.001). ITCH siRNA effectively inhibited the proliferation and invasion of the lung cancer cells and promoted cell apoptosis. Molecular analysis further showed significant reductions in the expression of Bcl2, MMP2, MMP9 and ß-catenin and an increase in the expression of Bax and E-cadherin in the lung cancer cells with ITCH deficiency. CONCLUSIONS: Inhibition of ITCH might suppress lung cancer proliferation and invasion via regulation of MMPs, EMT and Bcl2/Bax signaling pathway.

Insights into the roles of hnRNP A2/B1 and AXL in non-small cell lung cancer.

Lung cancer has long been one of the most serious types of malignant tumor, and is associated with high incidence and mortality rates. Despite advancements in the comprehensive treatment of the disease, particularly with targeted therapeutic agents, there has been little improvement in the 5-year survival rates of patients. One of the leading causes of mortality in lung cancer is the lack of effective early diagnostic criteria. On this basis, the present study aimed to identify an index with potential in the early diagnosis and prognosis of lung cancer. The current study determined the expression of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 and AXL proteins in non-small cell lung cancer (NSCLC) tumor samples, and performed prognostic analysis of the collected clinical data to identify any association. In addition, RNA interference was performed to silence the expression of hnRNP A2/B1, allowing evaluation of its molecular and cellular functions, and determination of the mechanism of hnRNP A2/B1 in NSCLC by means of AXL mediation. It was identified that the positive expression rate of hnRNP A2/B1 and AXL proteins were significantly higher in NSCLC compared with paracancerous lung tissues (P<0.05). Furthermore, the expression of hnRNP A2/B1 protein was correlated with the expression AXL. Thus, the expression of hnRNP A2/B1 and AXL protein are factors affecting prognosis in patients with NSCLC. Of these, hnRNP A2/B1 appears to be an independent risk factor.

[Analysis of clinical manifestations and genetic mutations in a child with Laron syndrome].

OBJECTIVE: To analyze clinical manifestations and gene mutations in a child with severe short stature, explore its molecular mechanism and further clarify the diagnostic procedure for short stature. METHOD: We observed clinical characteristics of a patient with short stature and did diagnostic examinations, assessed the function of GH-IGF-1 axis, and surveyed its family members.Genomic DNA was extracted from peripheral blood, GHR, IGFALS, STAT5b and GH1 gene were amplified by PCR for sequencing, including exons and splicing areas. RESULT: The patient presented symmetrical short stature (height -8.2 SDS) and facial features, and other congenital abnormalities.It displayed non-growth hormone deficiency. The baseline value of GH was 21 µg/L, and the peak was 57.9 µg/L. The value of IGF-1 was less than 25 µg/L, and the IGFBP-3 less than 50 µg/L. And IGF-1 generation test showed no response. There was no similar patients in the family members.Sequencing of GHR in the patient revealed a homozygous point mutation (c.Ivs6+1G>A), and her father and mother had the same heterozygous mutation. The same mutation was not identified for her sister.No other candidate gene was found. CONCLUSION: As the result of combined clinical characteristics and lab examinations, as well as gene detection, the case was diagnosed with Laron syndrome and GHR gene mutation is the molecular mechanism.We should explicit the etiological diagnosis for short stature, and avoid missed diagnosis and misdiagnosis.

[The mechanism of transforming growth factor beta1 in myofibroblast differentiation].

OBJECTIVE: To investigate the mechanism underlying myofibroblast differentiation induced by transforming growth factor (TGF) beta1 in obliterative bronchiolitis following lung transplantation. METHODS: Heterotopic tracheal transplantation was performed in Smad3 wild-type and knock-out mice to simulate the lung transplantation in human. Murine tracheal fibroblasts cultivated in primary culture were used for in vitro study. Immunohistochemistry, immunocytochemistry, Western Blotting, RT-PCR and DNA electrophoresis mobility gel shift assay were conducted to detect the expression of alpha-smooth muscle actin (alphaSMA), the marker of fibroblast-myofibroblast differentiation, and the activation of Smad3, p38 and ERK1/2. RESULTS: In affected airways of experimental obliterative bronchiolitis, abundant expression of alphaSMA were found. In vitro study for tracheal fibroblasts, the activation of Smad3 by TGF-beta1 presents as three major forms, phosphorylation, nuclear translocation and DNA binding. In Smad3 wild-type fibroblasts, TGF-beta1 induces the increase of the myofibroblasts transformation, characterized by the elevation of alphaSMA, both at transcription and protein level. While in Smad3 knock-out fibroblasts, the transformation of myofibroblasts induced by TGF-beta1 is significantly decreased (t = 2.080, P = 0.027; t = 1.982, P = 0.032), but not completely abolished. Further study in Smad3-deficient fibroblasts demonstrates that p38 and ERK1/2 could be activated by TGF-beta1 and result in fibroblast differentiation. CONCLUSIONS: TGF-beta1 could promote the transformation of fibroblasts into myofibroblasts in Smad3 dependent and independent signal pathways, especially the Smad3 dependent path, and result in the development of obliterative bronchiolitis.

[The role of transforming growth factor-beta1/Smad3 signaling in bronchiolitis obliterans following lung transplantation].

OBJECTIVE: To investigate the mechanism underlying bronchiolitis obliterans (OB) following lung transplantation and the significance of transforming growth factor (TGF)-beta1/Smad3 signal pathway in this pathological process. METHODS: The tracheas of BALB/c mice were transplanted into the subcutaneous tissues of a Smad3ex8/ex8 gene knock-out Swiss black mouse and a Smad3 wild-type Swiss black mouse. Forty-two days later the tracheas were taken out. Immunocytochemistry was used to detect the alpha-smooth muscle actin (alphaSMA), a marker of fibroblast-myofibroblast differentiation. The tracheas of Smad3 knock-out and wild type mice were taken out, broken to pieces, and cultured to obtain the fibroblasts. The tracheal fibroblasts in primary culture were treated with TGF-beta1. The activation of Smad3 molecules was investigated with immunocytochemistry, Western blotting and DNA electrophoresis mobility gel shift assay (EMSA). Immunocytochemistry staining was also employed to detect the cytoskeletal polymerization and alphaSMA immunofluorescence after incubation with TGF-beta1; Western blotting and RT-PCR was conducted to detect the difference of alphaSMA at transcriptional and protein level. RESULTS: The number of alphaSMA positive myofibroblasts was great in the experimental OB models produced be transplantation of heterogeneous trachea from Smad3 wild type mice and was very small in the OB model produced be transplantation of heterogeneous trachea from Smad3 knock-out mice (t = 2.125, P = 0.040). Western blotting showed that in vitro experiment showed that phosphorylation of Smad3 protein was increased in the fibroblasts treated with TGF-beta1 and was almost absent in those not treated with TGF-beta1. EMSA showed that DNA binding was increased in the fibroblasts treated with TGF-beta1 and was almost absent in those not treated with TGF-beta1. Immunofluorescence staining showed that the cytoplasm of the fibroblasts not treated with TGF-beta1 was Smad3 positive, however, the nuclei of the fibroblasts treated with TGF-beta1 was Smad3 positive. RT-PCR showed that the alphaSMA mRNA expression level in the Smad3 wild-type fibroblasts was increased after treated with TGF-beta1, and was significantly higher than in the Smad3 knock-out fibroblasts treated with TGF-beta1 (t = 2.080, P = 0.027). Western blotting showed that the alphaSMA protein expression level in the Smad3 wild-type fibroblasts was increased after treatment with TGF-beta1, and was significantly higher than that of the Smad3 knock-out fibroblasts (t = 1.982, P = 0.032). CONCLUSION: TGFbeta1 promotes the production of alphaSMA protein and transformation of fibroblasts into myofibroblasts through the Smad3 dependent signal pathway, thus resulting in the development of bronchiolitis obliterans.