ARL4C stabilized by AKT/mTOR pathway promotes the invasion of PTEN-deficient primary human glioblastoma

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) deficiency in primary human glioblastoma (GBM) is associated with increased invasiveness and poor prognosis with unknown mechanisms. Therefore, how loss of PTEN promotes GBM progression remains to be elucidated. Herein, we identified that ADP-ribosylation factor like-4C (ARL4C) was highly expressed in PTEN-deficient human GBM cells and tissues. Mechanistically, loss of PTEN stabilized ARL4C protein due to AKT/mTOR pathway-mediated inhibition of ARL4C ubiquitination. Functionally, ARL4C enhanced the progression of GBM cells in vitro and in vivo. Moreover, microarray profiling and GST pull-down assay identified that ARL4C accelerated tumor progression via RAC1-mediated filopodium formation. Importantly, targeting PTEN potently inhibited GBM tumor progression in vitro and in vivo, whereas overexpression of ARL4C reversed the tumor progression impaired by PTEN overexpression. Clinically, analyses with patients' specimens validated a negative correlation between PTEN and ARL4C expression. Elevated ARL4C expression but PTEN deficiency in tumor was associated with poorer disease-free survival and overall survival of GBM patients. Taken together, ARL4C is critical for PTEN-deficient GBM progression and acts as a novel prognostic biomarker and a potential therapeutic candidate. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Germinal center B cell initiation,GC maturation,and the coevolution of its stromal cell niches

Throughout the developing GC response, B cell survival and fate choices made at the single cell level are dependent on signals received largely through interactions with other cells, often with cognate T cells. The type of signals that a given B cell can encounter is dictated by its location within tissue microarchitecture. The focus of this review is on the initiation and evolution of the GC response at the earliest time points. Here, we review the key factors influencing the progression of GC B cell differentiation that are both stage and context dependent. Finally, we describe the coevolution of niches within and surrounding the GC that influence the outcome of the GC response.     

Molecular characterization of Coxsackievirus A16 strains isolated from children with severe hand,foot, and mouth disease in Yunnan,Southwest China,during 2009-2015

Coxsackievirus A16 (CV-A16) commonly causes mild symptoms, but severe diseases, such as aseptic meningitis, encephalitis, and even fatal cases, have been reported. Thirteen CV-A16 strains were isolated from patients with severe hand, foot, and mouth disease in Yunnan, Southwest China, from 2009 to 2015. Subgenotype B1a and B1b of CV-A16 were predominantly circulating the region with B1b the predominant strain in recent years. The mean rate of nucleotide substitution based on the VP1 gene sequence was 4.545 × 10 ⁻³ substitution per site per year from 2009 to 2015. These results may help in understanding the genetic diversity of CV-A16 and develop a CV-A16 vaccine.     

A cross-sectional serum investigation of a clustering hepatitis C virus infection in Southwest China

Serum samples were collected in a village with a clustering hepatitis C virus (HCV) infection. HCV antibody, HCV RNA loads, liver function indexes, HCV envelope antibody, and neutralizing activity were assessed. Among 851 adult sera, 342 samples were positive for anti-HCV. Of these positive samples, 254 (74.3%) were HCV RNA positive (≥800 copies/mL). None of the 69 children's sera were positive for HCV antibody or RNA. Among the HCV antibody positive sera, alanine aminotransferase, and aspartate aminotransferase levels increased with the higher virus loads, but decreased when virus loads were higher than 1 × 10 ⁶ copies/mL. HCV envelope antibody and neutralizing antibody levels increased with viral load.     

Prevalence characteristics of single and multiple HPV infections in women with cervical cancer and precancerous lesions in Beijing,China

We assessed the prevalence characteristics of single and multiple high-risk human papillomavirus (HR-HPV) infections. A total of 1783 women who underwent colposcopy and cervical biopsy for abnormal ThinPrep Cytology Test and/or HR-HPV subtype genotyping results were enrolled in the study. Among the participants, 770 were diagnosed with cervicitis, 395 with cervical intraepithelial neoplasia grade 1 (CIN1), 542 with CIN2-3, and 76 with squamous cell carcinoma (SCC), with HR-HPV infection rates of 75.8%, 85.8%, 95.9%, and 88.4%, respectively. The prevalence of total and multiple HR-HPV infections exhibited a bimodal age distribution with a peak at ≤25 years, a decline with age and a second peak at ≥55 years, whereas single HR-HPV infections exhibited one peak from 35 to 44 years. The four most dominant HPV genotypes were HPV 16 (29.5%), 52 (15.0%), 58 (14.2%), and 18 (10.4%). In total, 67.0%, 70.4%, and 82.1% of patients with CIN1, CIN2-3, and SCC, respectively, had a single HR-HPV infection, which increased significantly with the aggravation of the cervical lesion grade (P = 0.045). Patients with a single HPV 16 infection had higher incidences of CIN2+ (62.2%) than those with multiple HPV 16 infections (52.4%) (P = 0.021). Patients coinfected with HPV 16 had higher CIN2+ incidence than those with single HPV 52, 31, 33, 35, 39, 45, 51, 56, or 59 infections (P < 0.001). This study provided baseline data on the prevalence characteristics of single and multiple HR-HPV infections in women attending a gynecological outpatient clinic in Beijing.     

Epidemiology of human adenovirus infection in children hospitalized with lower respiratory tract infections in Hunan,China

To investigate the current genotypes of circulating human adenovirus (HAdV) strains, we molecularly genotyped HAdV in the nasopharyngeal aspirates (NPAs) of patients with acute lower respiratory tract infections (ALRTIs) and attempted to determine their associations with clinical symptoms. A total of 4751 NPA samples were collected from 4751 patients admitted to Hunan Provincial People's Hospital from September 2007 to March 2014, of which 447 (9.4%) samples were HAdV positive. Fourteen different HAdV types were identified; HAdV types 1 to 7 (HAdV 1-7) were identified in 95.7% of the 447 NPA samples with HAdV-7 and HAdV-3 being the most prevalent. In addition, 93.3% (417 of 447) of patients were younger than 5 years. The incidence of HAdV infection peaked in summer. Different HAdV types showed a predilection for different age groups and different seasonal distribution patterns. Coinfection of HAdVs and other respiratory viruses was detected in 63.3% (283 of 447) of the HAdV-positive samples. The most common clinical diagnosis was pneumonia and the most common symptoms were fever and cough. In comparison with children infected with HAdV-3 alone, those infected with HAdV-7 alone had an increased frequency of severe pneumonia involvement (11.6% vs 32.4%; P = 0.031), higher intensive care unit admission rates (7.0% vs 26.5%; P = 0.019), and a longer length of hospital stay (P = 0.03). Mixed infections in younger children were associated with a longer hospital stay (P = 0.023). Our results demonstrate the recent changes in the trends of circulating HAdV genotypes associated with ALRTIs in Hunan China.