Evaluating the use of hypoxia sensitive markers for body fluid stain age prediction
SCIENCE & JUSTICE
Authors: Asaghiar, Fisal; Williams, Graham A.
Abstract
To augment DNA profiling and body fluid identification techniques efforts are being made to increase the amount of information available from a crime scene stain, which includes efforts to identify externally visible characteristics through phenotypic analysis. A key question surrounding crime scene stains is the length of time between deposition of the stain and its subsequent recovery, in that is the stain recovered related to the incident in question or from a previously deposited stain number of weeks earlier? The inability to answer this fundamental question has a detrimental effect upon the successful completion of a criminal investigation. Once a body fluid leaves the body, the oxygen concentration in the environment changes; therefore, it may be that this change could cause a change in the expression of hypoxia-sensitive biomarkers. Here, a range of bloodstains, liquid saliva and liquid semen samples were collected at 0 days, 7 days, 14 days, 21 days and 28 days of degrading at room temperature (19-22 degrees C), before undergoing total RNA extraction and cDNA synthesis. Blood was recovered from filter paper with 3 mm2, with saliva and semen being left in their tubes and swabbed at the appropriate times. All samples then underwent quantitative PCR targeting Vascular Endothelial Growth Factor A (VEGFA) and Hypoxia-Inducible Factor 1 Alpha (HIF1A), with B-Actin (ACTB) as a reference gene. A range of linear and quadratic correlation values was obtained from the qPCR data and used to develop a predictive model with a mean absolute deviation (MAD) of 4.2, 2.1, and 5 days for blood, saliva, and semen respectively. Blind testing indicated that a stain age prediction model based upon VEGFA with ACTB as a reference gene could be used on samples up to four weeks old with a margin of error ranging from 2 days through to 5 days. While a sizeable potential time frame exists using this model; this represents a significant step towards the target of having an accurate stain age prediction model.
Knockdown of FBXO22 inhibits melanoma cell migration, invasion and angiogenesis via the HIF-1 alpha/VEGF pathway
INVESTIGATIONAL NEW DRUGS
Authors: Zheng, Yufan; Chen, Hairong; Zhao, Yang; Zhang, Xuping; Liu, Jinjin; Pan, Yu; Bai, Jin; Zhang, Hongwei
Abstract
F-box proteins, a type of substrate-recognition complexes consisting of SKP1-cullin 1-F-box protein (SCF) E3 ligase, can critically affect many cellular processes because of the ubiquitylation and subsequent degradation of target proteins. This study investigated the effect of FBXO22 on melanoma angiogenesis, migration, and invasion. Results showed that FBXO22 staining intensity was increased in malignant melanoma (MM) compared with that in skin tissue (P<0.001). The percentage of high FBXO22 expression in MM (74.3%) was markedly higher than that in paracancerous and skin tissues (0%) (P<0.001). FBXO22 was also overexpressed in MM tissues compared with that in normal skin tissues. FBXO22 knockdown in vitro inhibited MM cell migration, invasion, and angiogenesis (P < 0.001). In vivo studies confirmed that using nude mice with knocked down FBXO22 reduced the formation of blood vessels and decreased the positive rate of CD31 (P < 0.05). HIF-1 alpha expression varied with FBXO22, indicating that FBXO22 regulated the expression of HIF-1 alpha and VEGFA and that FBXO22 was a regulator of HIF-1 alpha and VEGF for the control of tumor angiogenesis. In conclusion, FBXO22 promoted the migration and invasion of tumor cells and melanoma angiogenesis via HIF-1 alpha upregulation. This study demonstrated that FBXO22 knockdown suppressed tumor progression and metastasis, suggesting that FBXO22 might be developed as a novel target for treating patients with MM.