Penghui Zhang

β-arrestin2 mediates β-2 adrenergic receptor signaling inducing prostate cancer cell progression

The expression of the β-2 adrenergic receptor (β2AR), one of the stress-inducible receptors, has been reported to be closely correlated with malignant tumors. Prostate cancer is the most common non-cutaneous cancer among males, accompanied with increased castration levels and β2AR activation in patients. However, the role of β2AR activation in prostate cancer cells and its underlying mechanisms are not fully understood. Here, we found that β2AR activation promoted cell proliferation and cell migration through increasing cellular adenylyl cyclase (cAMP) levels and ERK1/2 activation in LNCaP and PC3 prostate cancer cells. Moreover, the scaffold protein β-arrestin2 was found to be involved in the β2AR-mediated activation of ERK1/2 and cell proliferation using stable overexpressing β-arrestin2 LNCaP (LNCaP-βArr2) cells. Furthermore, enhanced β-arrestin2/c-Src complex formation by β2AR activation was observed in LNCaP-βArr2 cells. In addition, the c-Src inhibitor could block this enhanced complex formation and suppressed cell proliferation. This study demonstrates that βArr2 is involved in prostate carcinogenesis induced by stress and provides potential therapeutic targets for cancer.

Elevated β-arrestin1 expression correlated with risk stratification in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the main subtype of childhood leukemia. Risk stratification is pivotal for ALL prognosis and individualized therapy. The current factors for risk stratification include clinical and laboratory features, cytogenetic characteristics of the blast, early response to chemotherapy, and genetic factors. Analyses of gene expression are becoming increasingly important in ALL risk stratification. β-Arrestin1, a multifunctional scaffold protein mediating many intracellular signaling networks, has been shown to be involved in many tumors. However, little is known of β-arrestin1 in leukemia. In this study, we found that β-arrestin1 was significantly elevated in 155 newly diagnosed ALL patients, compared with 51 controls. Further analysis showed that β-arrestin1 expression was positively related with risk classification and white blood cell count in ALL. Moreover, expression of Notch1, an essential gene for developing hematological cells and T-ALL, was found to be negatively correlated with β-arrestin1 in ALL. In conclusion, β-arrestin1 may be a useful predictor of risk stratification and prognosis of ALL, and thus of potential use in the design of individualized therapy strategies.

β-Arrestin1 promotes the self-renewal of the leukemia-initiating cell-enriched subpopulation in B-lineage acute lymphoblastic leukemia related to DNMT1 activity

The self-renewal ability of the leukemia initiating cell-enriched subpopulation is critical for leukemia initiation and maintenance. However, the regulation of leukemia initiating cells for the leukemia progression is poorly understood. In this study, we observed that β-Arrestin1, a multiple-function protein, is elevated in leukemia initiating cells-enriched fraction from B-lineage acute lymphoblastic leukemia patients. The loss of β-Arrestin1 in leukemia initiating cells-enriched fraction attenuates its self-renewal capacity both in vitro and in vivo. Further experiments showed that the mRNA expression level of β-Arrestin1 is negatively correlated with that of PTEN in leukemia initiating cells-enriched fraction. Moreover, DNA methylation of the PTEN promoter region, the activity and expression of DNMTs were enhanced in the leukemia initiating cells-enriched fraction. The inhibition of DNMT1 activity impaired the self-renewal and increased expression of PTEN of leukemia initiating cells-enriched fraction. In addition, depletion of β-Arrestin1 significantly decreased DNMT1 activity and PTEN methylation, and consistently increased PTEN expression in leukemia initiating cells-enriched fraction. Our study reveals a novel function of β-Arrestin1 in the regulation of the self-renewal of leukemia initiating cells-enriched fraction from B-lineage acute lymphoblastic leukemia patients related to DNMT1 activity, indicating that β-Arrestin1 is a potential therapeutic target in B-lineage acute lymphoblastic leukemia.

Epidemiology of 45,616 suspect cases of Hand, Foot and Mouth Disease in Chongqing, China, 2011–2015

Epidemiology and etiology of hand, foot, and mouth disease (HFMD) based on large sample size or evaluation of detection for more enterovirus serotypes are not well investigated in Chongqing of China. 45,616 suspect HFMD patients were prospectively enrolled among whom 21,615 were laboratory confirmed HFMD cases over a 5-year period (January 2011 to December 2015). Their epidemiological, clinical, and laboratory data were extracted and stratified by month, age, sex, disease severity, and enterovirus serotype. Subsequently 292 non-EV-A71/CV-A16 HFMD confirmed cases were randomly selected in three consecutive outbreaks to detect CV-A6 and CV-A10, using RT-PCR. Results showed that the HFMD epidemic peaked in early summer and autumn. The median age of onset was 2.45 years with a male-to-female ratio of 1.54:1, and with children under 5 years of age accounting for 92.54% of all confirmed cases. EV-A71 and CV-A16 infection accounted for only 36.05% (7793/21615) of total confirmed cases while EV-A71 accounted for 59.64% (232/389) of severe cases. Importantly, the proportion of EV-A71 infection generally increased with age which showed rapid growth in severe cases. CV-A6 and CV-A10 were tested positive in Chongqing, but CV-A6 had greater positive rates of 62.33% while CV-A10 had 4.79% in non-EV-A71/CV-A16 HFMD confirmed cases.

The cellular senescence of leukemia-initiating cells from acute lymphoblastic leukemia is postponed by β -Arrestin1 binding with P300-Sp1 to regulate hTERT transcription

Although we previously reported that the self-renewal of leukemia-initiating cells of B-lineage acute lymphoblastic leukemia (B-ALL LICs) was regulated by β-Arrestin1, a multiple-function protein, the cellular senescence is critical for LICs fate and leukemia progress, and worthy for further investigation. Here we found that depletion of β-Arrestin1 extended the population doubling time and the percentage of senile cells, the signatures of cellular senescence, of B-ALL LICs. Moreover, lack of β-Arrestin1 enhanced the expression of proteins (CBX, HIRA) and genes (P53, P16) related to senescence in leukemic Reh cells and B-ALL-LICs-derived leukemic mice. Further results showed that loss of β-Arrestin1 induced senescence of Reh cells through mediating hTERT-telomerase-telomere axis, which was reversed by BIBR1532, the telomerase activity inhibitor. Importantly, depletion of β-Arrestin1 decreased the binding of Sp1 to hTERT promoter at the region of −28 to −36 bp. The anti-sense oligonucleotide of this key region downregulated the transcription of hTERT and aggravated the senescence of Reh cells. Further data demonstrated that the depleted β-Arrestin1 reduced the interaction of P300 with Sp1, thus to reduce Sp1 binding to hTERT promoter, downregulate hTERT transcription, decrease telomerase activity, shorten telomere length, and promote Reh cell senescence. Interestingly, the percentage of senile cells in B-ALL LICs was decreased, which was negatively correlated to good prognosis and β-Arrestin1 mRNA expression in childhood B-ALL patients. Our study shed a light on the senescence of B-ALL LICs and is regulated by β-Arrestin1, providing the potential therapeutic target of leukemia by promoting cellular senescence with a key region of hTERT promoter.

High proportion of CD34+/CD38-cells is positively correlated with poor prognosis in newly diagnosed childhood acute lymphoblastic leukemia.

Abstract The CD34+/CD38− immunophenotype is used to identify candidate hematopoietic stem cells (HSCs) and leukemia-initiating cells (LICs). However, the clinical significance of the CD34+/CD38−proportion in childhood acute lymphoblastic leukemia (ALL) is not well established. Here, we found that a high proportion of CD34+/CD38− cells from 112 patients with childhood ALL was negatively correlated with the outcome. Also the percentage of CD34+/CD38− cells was associated with clinical and biological features of patients with ALL. Further, a high proportion of CD34+/CD38− cells in childhood ALL was positively correlated with advanced risk subgroups, which could predict risk stratification by receiver operating characteristic (ROC) curve analysis. In addition, a larger tumor burden and lower survival rate were observed in mice injected with CD34+/CD38− cells, but not in mice injected with other fractions. Our data reveal that a high proportion of CD34+/CD38− cells is positively associated with a poor prognosis of childhood ALL, to further guide therapy of the disease.