New tripodal hydroxypyridinone based chelating agents for Fe(III), Al(III) and Ga(III): Synthesis, physico-chemical properties and bioevaluation

Two new tris-hydroxypyridinone based compounds (KEMPPr(3,4-HP)₃ and KEMPBu(3,4-HP)₃) have been developed and studied as strong sequestering agents for iron and the group III of metal ions, aimed as potential pharmacological applications on metal-chelation therapy. Their structure is based on the KEMP acid scaffold to which three 3-hydroxy-4-pyridinone chelating moieties are attached via two different size spacers. After the preparation and characterization of the compounds their physico-chemical properties were studied, in relation with their metal binding affinity and lipophilicity. The KEMPPr(3,4-HP)₃ ligand was also bioassayed to evaluate its in vivo metal sequestering capacity from most organs using an animal model overload with ⁶⁷Ga. These studies showed that, for both in solution and in vivo conditions, the compounds have higher metal chelating efficacy than Deferriprone, the commercially available iron chelator in medical application, thus some perspectives are envisaged as potential pharmaceutical drug candidates for chelating therapy.     

Ki-67 as a prognostic marker in mantle cell lymphoma��consensus guidelines of the pathology panel of the European MCL Network

Mantle cell lymphoma (MCL) has a heterogeneous clinical course and is mainly an aggressive B cell non-Hodgkin lymphoma; however, there are some indolent cases The Ki-67 index, defined by the percentage of Ki-67-positive lymphoma cells on histopathological slides, has been shown to be a very powerful prognostic biomarker. The pathology panel of the European MCL Network evaluated methods to assess the Ki-67 index including stringent counting, digital image analysis, and estimation by eyeballing. Counting of 2 × 500 lymphoma cells is the gold standard to assess the Ki-67 index since this value has been shown to predict survival in prospective randomized trials of the European MCL Network. Estimation by eyeballing and digital image analysis showed a poor concordance with the gold standard (concordance correlation coefficients [CCC] between 0.29 and 0.61 for eyeballing and CCC of 0.24 and 0.37 for two methods of digital image analysis, respectively). Counting a reduced number of lymphoma cells (2 × 100 cells) showed high interobserver agreement (CCC = 0.74). Pitfalls of the Ki-67 index are discussed and guidelines and recommendations for assessing the Ki-67 index in MCL are given.     

Caveolin-1 overexpression correlates with tumour progression markers in pancreatic ductal adenocarcinoma

The assessment of caveolin-1 (Cav-1) as a marker of tumor aggressiveness in pancreatic ductal adenocarcinoma (PDAC). In this study, we examined the expression of Cav-1 in 34 human PDAC tissue samples and the associated peritumoral tissues by immunohistochemistry and western blot. Additionally, we correlated Cav-1 expression with other tissue (Ki-67, p53) and serum (CA 19-9) tumor markers. In the tumor-derived tissue, both tumor cells and blood vessels expressed Cav-1. In contrast, in peritumoral tissue, Cav-1 expression was confined mainly to blood vessels and was only occasionally expressed in ductal or parenchymal cells. Western blot analysis confirmed the overexpression of Cav-1 in pancreatic tumors compared with peritumoral tissue. Cav-1 expression in tumor tissues was correlated with both the Ki-67 LI (r = 0.95, P < 0.0001) and p53 expression (χ2 = 9.91, P < 0.005). Overexpression of Cav-1 was associated with tumor size, grade and stage and Cav-1 expression in tumors was correlated with an increased serum level of CA 19-9 (r = 0.795, P < 0.001). Based on the results of this study, the inclusion of Cav-1 in a putative panel of biomarkers predicting pancreatic cancer aggressiveness is warranted.     

Altered expression of cellular membrane molecules of HLA-DR, HLA-G and CD99 in cervical intraepithelial neoplasias and invasive squamous cell carcinoma

OBJECTIVE: The aim of this study was to investigate the role of HLA-DR, HLA-G and CD99 during cervical carcinogenesis and to examine the prognostic significance of these protein expressions in invasive squamous cell carcinoma (SCC). METHODS: Using specific antibodies for HLA-DR, HLA-G and CD99, we examined protein expressions in 19 normal cervix, 15 mild dysplasia (CIN I), 22 moderate dysplasia (CIN II), 23 severe dysplasia (CIN III), and 34 invasive squamous cell carcinoma by immunohistochemistry. And we detected the expression of Ki67 in the same specimens. RESULTS: None of normal cervix and CINs except three cases of CIN III expressed HLA-DR. HLA-DR expression increased progressively with the grade of the tumor, and significant differences could be observed between grade 1 and grade 2 (P<0.01) and between grade 1 and grade 3 (P<0.05). In all normal epithelial control samples, HLA-G expression was seen in ectocervical squamous and endocervical columnar epithelium and the staining was strong and uniform. Only a small proportion of CINs and SCCs showed reduced expression of HLA-G. Compared with the results in the control samples, CINs and SCCs showed significantly reduced expression of HLA-G (P<0.001). SCCs showed significantly increased expression of CD99 when compared with normal cervix and CINs (P<0.05). Ki67 was expressed in all specimens. Significant differences were observed between CINs and normal cervix (P<0.001) and SCCs and controls (P<0.001), but no significant differences could be observed between SCCs and CINs. None of the expressions of these proteins was associated with any of clinicopathological parameters. CONCLUSIONS: These results indicate that increased expression of HLA-DR and CD99 may be related to the evolution of cervical cancer. All protein expressions were not associated with clinicopathological parameters.     

Mapping early fate determination in Lgr5+ crypt stem cells using a novel Ki67‐RFP allele

Cycling Lgr5⁺ stem cells fuel the rapid turnover of the adult intestinal epithelium. The existence of quiescent Lgr5⁺ cells has been reported, while an alternative quiescent stem cell population is believed to reside at crypt position +4. Here, we generated a novel Ki67^RFP knock-in allele that identifies dividing cells. Using Lgr5-GFP;Ki67^RFP mice, we isolated crypt stem and progenitor cells with distinct Wnt signaling levels and cell cycle features and generated their molecular signature using microarrays. Stem cell potential of these populations was further characterized using the intestinal organoid culture. We found that Lgr5^high stem cells are continuously in cell cycle, while a fraction of Lgr5^low progenitors that reside predominantly at +4 position exit the cell cycle. Unlike fast dividing CBCs, Lgr5^low Ki67⁻ cells have lost their ability to initiate organoid cultures, are enriched in secretory differentiation factors, and resemble the Dll1 secretory precursors and the label-retaining cells of Winton and colleagues. Our findings support the cycling stem cell hypothesis and highlight the cell cycle heterogeneity of early progenitors during lineage commitment.     

Ki67 Antigen Contributes to the Timely Accumulation of Protein Phosphatase 1γ on Anaphase Chromosomes

Ki67 is a protein widely used as cell-proliferation marker, with its cellular functions being hardly unveiled. In this paper, we present the direct interaction between Ki67 and PP1γ, a protein phosphatase showing characteristic accumulation on anaphase chromosomes via the canonical PP1-binding motif within Ki67. In cells depleted of Ki67, PP1γ is targeted to anaphase chromosomes less efficiently. Additionally, overexpression of Ki67, but not a mutant form without the ability to bind PP1γ, induced ectopic localization of PP1γ οn metaphase chromosomes. These observations demonstrate that Ki67 is one factor that defines the cellular behavior of PP1γ in anaphase. To explore the specific roles of the subset of PP1γ recruited on chromosome via its interaction with Ki67 (PP1γ-Ki67), endogenous Ki67 was replaced with a Ki67 mutant deficient in its ability to interact with PP1γ. Although no obvious defects in the progression of mitosis were observed, the timing of dephosphorylation of the mutant Ki67 in anaphase was delayed, indicating that Ki67 itself is one of the substrates of PP1γ-Ki67.     

Evaluation of p16/Ki-67 dual staining in the detection of cervical precancer and cancer in China

Background This study aimed to evaluate the clinical performance of p16/Ki-67 dual staining in the detection of cervical intraepithelial neoplasia grade 2 or 3 or worse (CIN2+/CIN3+) in Chinese women.Methods Cervical exfoliated cells were collected from 537 eligible women and were used for liquid-based cytology (LBC), p16/Ki-67 dual staining, and human papillomavirus (HPV) DNA testing. All women received colposcopy with biopsies taken at abnormal sites. Histopathological diagnoses were used as the gold standard.Results p16/Ki-67 staining had a positivity rate of 43.58% overall; the rate increased significantly with histological severity (p <0.001). The sensitivities of p16/ki-67 for detecting CIN2+ and CIN3+ were 88.10% and 91.30%, respectively. Compared with high-risk HPV (HR-HPV), sensitivity of p16/Ki-67 was lower for detecting CIN2+ (88.10% versus 95.71%), but similar for detecting CIN3+ (91.30% versus 96.27%). Specificities of p16/Ki-67 were 85.02% for detecting CIN2+ and 76.86% for detecting CIN3+, values similar to those for LBC (84.71% for CIN2+, 80.05% for CIN3+) but higher than those for HR-HPV (62.77% for CIN2+, 71.25% for CIN3+). All the tests performed better in women>30 years. With respect to the performance of triage for women with ASC-US, sensitivities of p16/Ki-67 were 86.36% for detecting CIN2+ and 83.33% for detecting CIN3+, values similar to those of HR-HPV. However, specificities of p16/Ki-67 were both higher than those of HR-HPV (85.96% versus 67.54% for CIN2+, 79.84% versus 62.90% for CIN3+).Conclusion P16/Ki-67 dual staining could probably provide an optional method for China’s national cervical cancer screening, and could also be considered as an efficient method of triage for managing women with ASC-US.     

Efficacy of Ki-67 antigen staining in Papanicolaou (Pap) smears in post-menopausal women with atypia—an audit

In cervical smears from post-menopausal women with mucosal atrophy it can be difficult to distinguish atrophic epithelial cell groups from neoplastic cell groups on cytomorphological criteria only. The consequence of post-menopausal atypia is that the woman is referred for a repeat smear after local oestrogen treatment or for colposcopy. We investigated whether immunocytochemical expression of Ki-67 (MIB-1) on the primary Papanicolaou-stained smear could be of any diagnostic help. Our data showed that negative Ki-67 expression is a very reliable indicator of a normal atrophic cell pattern, and by using this method on the original smear we were able to reduce the false-positive cytologic diagnoses by 86%.     

Measuring the bioavailable/toxic concentration of copper in natural water by using anodic stripping voltammetry and Vibrio-qinghaiensis sp.Nov.-Q67 bioassay

Abstract

Bioassays were carried out in the culture media for Vibrio-qinghaiensis sp.Nov.-Q67 and the influences of alkalinity and different concentrations of chloride, ethylene diamine tetraacetic acid (EDTA) and natural derived fulvic acid (FA) on the labile concentration and toxicity of Cu were investigated. The labile concentration of Cu was obtained by differential pulse anodic stripping voltammetry with a double acidification method (DAM-DPASV). Changes in water alkalinity and chloride concentrations did not affect the labile concentration of Cu, but increases of alkalinity and concentrations of chloride reduced the toxicity on Q67. In the presence of EDTA and FA, both labile concentration of Cu and toxicity were reduced. By excluding Cu-carbonate complexes and Cu-chloride from labile concentration, a bioavailable concentration of Cu (or [Cu*]) was obtained and used to predict the acute toxicity of Cu on Q67. For natural waters, the labile concentration of Cu was measured by DAM-DPASV and [Cu*] was calculated by a MINTEQ A2 software based on composition of waters. This procedure was tested for Guanting Reservoir waters by spiking different concentration Cu. The results showed that [Cu*] was a good indicator for Cu toxicity and could be used in field conditions.