ARRB1-Promoted NOTCH1 Degradation Is Suppressed by OncomiR miR-223 in T-cell Acute Lymphoblastic Leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is a type of aggressive leukemia with inferior prognosis. Although activating mutations of NOTCH1 are observed in most T-ALL cases, these mutations alone are not sufficient to drive the full development of T-ALL. ß-Arrestins (ARRB) are versatile and multifunctional adapter proteins that regulate diverse cellular functions, including promoting the development of cancer. However, the role of ARRBs in T-ALL has largely remained elusive. In this study, we showed that ARRB1 is expressed at low levels in assayed T-ALL clinical samples and cell lines. Exogenous ARRB1 expression inhibited T-ALL proliferation and improved the survival of T-ALL xenograft animals. ARRB1 facilitated NOTCH1 ubiquitination and degradation through interactions with NOTCH1 and DTX1. Mechanistically, the oncogenic miRNA (oncomiR) miR-223 targets the 3'-UTR of ARRB1 (BUTR) and inhibits its expression in T-ALL. Furthermore, overexpression of the ARRB1-derived miR-223 sponge suppressed T-ALL cell proliferation and induced apoptosis. Collectively, these results demonstrate that ARRB1 acts as a tumor suppressor in T-ALL by promoting NOTCH1 degradation, which is inhibited by elevated miR-223, suggesting that ARRB1 may serve as a valid drug target in the development of novel T-ALL therapeutics.Significance: These findings highlight a novel tumor suppressive function of the adaptor protein ß-arrestin1 in T-ALL.

[Respiratory physicians' knowledge, attitude and practice of tobacco control and their smoking status in the city of Chongqing].

OBJECTIVE: To investigate the smoking status, knowledge of smoking hazards, attitude of tobacco control and skill of assisting smoking cessation in respiratory physicians in the city of Chongqing and therefore to provide references for their further participation in social tobacco control. METHODS: With a self-designed questionnaire, a cross-sectional study was conducted on respiratory physicians of 8 hospitals in Chongqing, which were selected with stratified random sampling method. All the data were inputted with software Epidata 3.1 and were analyzed with SPSS 13.0. RESULTS: A total of 428 valid questionnaires were retrieved, with a valid rate of 95.1% (428/450). The total smoking rate was 12.4% (95%CI: 9.3% - 15.5%), with 7.4% in physicians of teaching hospitals, 8.13% in those of hospitals located in urban areas, and 19.0% in those of hospitals located in suburban district counties. The differences in smoking rates in the respiratory physicians among different hospitals showed statistical significance (χ(2) = 11.734, P = 0.014). The smoking rate of the male was higher than that of the female. Of the surveyed doctors, 80.14% had awareness that tobacco dependence was a neuropsychiatric disease characterized as nicotine addiction, while 34.8% claimed that they had no idea about quitting smoking drugs. Although all participants claimed that they knew the harm of secondhand smoke, 16.36% of them still had never come forward to prevent smoking behavior in hospitals. There was only 27.4% of the surveyed discouraging smoking behavior with the reason of unwillingness to breath in secondhand smoke, while 53.9% of the surveyed discouraged smoking behavior because of regulations of hospitals. Most of the surveyed did relatively well in routinely inquiring and recording the smoking status of patients, but only 27.1% of them had recommended specific quitting smoking methods to patients, and there were few successful cases in practice. The situations of smoking cessation assistance in hospitals located in urban areas and suburban district counties were better than that in teaching hospitals. CONCLUSIONS: The smoking rate of the respiratory physicians (especially male doctors) in Chongqing is high. There is lack of enthusiasm in preventing smoking behavior in public area of hospitals. The knowledge and skills of smoking cessation are lacking as well. Therefore more training programs for smoking control are needed. Respiratory physicians in primary hospitals or community health centers can play a more important role in smoking control.

[Survivin antisense oligodeoxynucleotides inhibits the proliferation of hepatocellular carcinoma cells and enhances 5-FU sensitivity].

OBJECTIVE: To investigate the inhibitory effect of survivin antisense oligodeoxynuleotides (ASODN) mediated by polyethylenimine (PEI) on hepatocelluar carcinoma SMMC-7721 cell proliferation and its effect on chemosensitivity to 5-FU in tumor-bearing mice. METHODS: The inhibitory effect of PEI-ASODN on SMMC-7721 cell proliferation was assayed by WST-8 test, Trypan blue exclusion test, and cell clone formation assay. In mouse models of transplanted H22 cell hepatocarcinoma and ascites tumor, the effect of 5-FU combined with PEI-ASODN on the weight and volume of the subcutaneous tumors was examined. The tumor inhibition rate in the tumor-bearing mice was calculated and the average survival time recorded. RESULTS: SMMC-7721 cells incubated with different concentrations of PEI-ASODN for 48 h showed significantly reduced cell proliferation in comparison with the control cells, while PEI or ASODN alone produced no such inhibitory effect. Incubation of SMMC-7721 cells with 0.75 micromol/L PEI-ASODN for 24, 48, 72, and 96 h resulted in significantly suppressed cell proliferation, and a 7-day incubation of the cells with PEI-ASODN at different concentrations (0.25-0.75 micromol/L) significantly inhibited the cell clone formation. In the tumor-bearing mice, the tumor weight and volume were obviously reduced with a tumor inhibition rate of 56.91% and volume inhibition rate of 57.83%, significantly different from those in saline-treated mice (P<0.01). In the mice bearing ascites tumor, the average survival time was 22.0 days in saline group and 42.7 days in 5-FU+PEI-ASODN treatment group, showing a a life-prolonging rate of 94.09% in the latter group. A synergetic effect was noted between 5-FU and PEI-ASODN. CONCLUSION: PEI-ASODN complex can significantly inhibit the proliferation of hepatocarcinoma SMMC-7721 cells and enhance 5-FU chemosensitivity of the tumor cells in vitro and transplanted H22 tumors in mice.

[Survivin antisense oligodeoxynucleotides inhibits the proliferation of hepatocellular carcinoma cells and enhances the cell chemosensitivity to 5-Fu].

OBJECTIVE: To investigate the inhibitory effect of survivin antisense oligodeoxynucleotides (ASODN) mediated by polyethylenimine(PEI) on the proliferation of hepatocellular carcinoma SMMC-7721 cells, and assess its detect on the chemosensitivity of the cells to 5-FU. METHODS: The inhibitory effect of PEI-ASODN on SMMC-7721 cell proliferation was assessed using WST-8 test, trypan blue staining, and cell clone formation test. In mice bearing transplanted hepatocarcinoma and ascites tumor derived from H22 cells, 5-FU combined with PEI-ASODN was administered, and the weight and volume of the subcutaneous tumors were measured to calculate the tumor inhibition rate, and the average survival time of the mice was calculated. RESULTS: Incubation of the cells with different concentrations of PEI-ASODN for 48 h significantly inhibited the cell proliferation as compared with the control group, but PEI or ASODN alone produced no significant inhibitory effects. At 24, 48, 72, 96 h of incubation of the SMMC-7721 cells with 0.75 micromol/L PEI-ASODN, the cell proliferation was suppressed significantly, and incubation with PEI-ASODN at 0.25-0.75 micromol/L for 7 days resulted in significantly inhibited cell clone formation. No significant inhibition was detected in ASODN and PEI group. The tumor weight and volume were reduced in all the treated groups. The tumor inhibition rate was 56.91% and volume inhibition rate was 57.83% in 5-FU+PEI-ASODN group, significantly different from those in the normal saline group (P<0.01). In mice bearing ascites tumor, the average survival time was 22.0 days in saline group, and 42.7 days 5-FU+PEI-ASODN group. The life-prolongation rate of 5-FU+PEI-ASODN was 94.09% when compared with the survival time in saline group. A cooperative effect was detected between 5-FU and PEI-ASODN. CONCLUSION: PEI-ASODN complex can significantly inhibit the proliferation of hepatocarcinoma SMMC-7721 cells and enhance the chemosensitivity of the tumor cells to 5-FU.