- Browse by Subject
Browsing by Subject "vascular endothelial growth factor"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Angiogenesis: A Cellular Response to Traumatic Injury(Wolters Kluwer, 2020) Pecoraro, Anthony R.; Hosfield, Brian D.; Li, Hongge; Shelley, W. Christopher; Markel, Troy A.; Surgery, School of MedicineThe development of new vasculature plays a significant role in a number of chronic disease states, including neoplasm growth, peripheral arterial disease, and coronary artery disease, among many others. Traumatic injury and hemorrhage, however, is an immediate, often dramatic pathophysiologic insult which can also necessitate neovascularization to promote healing. Traditional understanding of angiogenesis involved resident endothelial cells branching outward from localized niches in the periphery. Additionally, there are a small number of circulating endothelial progenitor cells which participate directly in the process of neovessel formation. The bone marrow stores a relatively small number of so-called pro-angiogenic hematopoietic progenitor cells (PACs) – that is, progenitor cells of a hematopoietic potential that differentiate into key structural cells and stimulate or otherwise support local cell growth/differentiation at the site of angiogenesis. Following injury, a number of cytokines and intercellular processes are activated or modulated to promote development of new vasculature. These processes initiate and maintain a robust response to vascular insult, allowing new vessels to canalize and anastomose and provide timely oxygen delivering to healing tissue. Ultimately as we better understand the key players in the process of angiogenesis we can look to develop novel techniques to promote healing following injury.Item Gene Expression Analysis Reveals Distinct Pathways of Resistance to Bevacizumab in Xenograft Models of Human ER-Positive Breast Cancer(Ivyspring, 2014) Gökmen-Polar, Yesim; Goswami, Chirayu P.; Toroni, Rachel A.; Sanders, Kerry L.; Mehta, Rutika; Sirimalle, Usha; Tanasa, Bogdan; Shen, Changyu; Li, Lang; Ivan, Mircea; Badve, Sunil S.; Sledge, George W.; Pathology and Laboratory Medicine, School of MedicineBevacizumab, the recombinant antibody targeting vascular endothelial growth factor (VEGF), improves progression-free but not overall survival in metastatic breast cancer. To seek further insights in resistance mechanisms to bevacizumab at the molecular level, we developed VEGF and non-VEGF-driven ER-positive MCF7-derived xenograft models allowing comparison of tumor response at different timepoints. VEGF gene (MV165) overexpressing xenografts were initially sensitive to bevacizumab, but eventually acquired resistance. In contrast, parental MCF7 cells derived tumors were de novo insensitive to bevacizumab. Microarray analysis with qRT-PCR validation revealed that Follistatin (FST) and NOTCH were the top signaling pathways associated with resistance in VEGF-driven tumors (P<0.05). Based on the presence of VEGF, treatment with bevacizumab resulted in altered patterns of metagenes and PAM50 gene expression. In VEGF-driven model after short and long-term bevacizumab treatments, a change in the intrinsic subtype (luminal to myoepithelial/basal-like) was observed in association with increased expression of genes implicated with cancer stem cell phenotype (P<0.05). Our results show that the presence or absence of VEGF expression affects the response to bevacizumab therapy and gene pathways. In particular, long-term bevacizumab treatment shifts the cancer cells to a more aggressive myoepithelial/basal subtype in VEGF-expressing model, but not in non-VEGF model. These findings could shed light on variable results to anti-VEGF therapy in patients and emphasize the importance of patient stratification based on the VEGF expression. Our data strongly suggest consideration of patient subgroups for treatment and designing novel combinatory therapies in the clinical setting.Item Molecular examination of bone marrow stromal cells and chondroitinase ABC-assisted acellular nerve allograft for peripheral nerve regeneration(Spandidos, 2016-10) Wang, Ying; Jia, Hua; Li, Wen-Yuan; Guan, Li-Xin; Deng, Lingxiao; Liu, Yan-Cui; Liu, Gui-Bo; Department of Anatomy and Cell Biology, IU School of MedicineThe present study aimed to evaluate the molecular mechanisms underlying combinatorial bone marrow stromal cell (BMSC) transplantation and chondroitinase ABC (Ch-ABC) therapy in a model of acellular nerve allograft (ANA) repair of the sciatic nerve gap in rats. Sprague Dawley rats (n=24) were used as nerve donors and Wistar rats (n=48) were randomly divided into the following groups: Group I, Dulbecco's modified Eagle's medium (DMEM) control group (ANA treated with DMEM only); Group II, Ch-ABC group (ANA treated with Ch-ABC only); Group III, BMSC group (ANA seeded with BMSCs only); Group IV, Ch-ABC + BMSCs group (Ch-ABC treated ANA then seeded with BMSCs). After 8 weeks, the expression of nerve growth factor, brain-derived neurotrophic factor and vascular endothelial growth factor in the regenerated tissues were detected by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Axonal regeneration, motor neuron protection and functional recovery were examined by immunohistochemistry, horseradish peroxidase retrograde neural tracing and electrophysiological and tibialis anterior muscle recovery analyses. It was observed that combination therapy enhances the growth response of the donor nerve locally as well as distally, at the level of the spinal cord motoneuron and the target muscle organ. This phenomenon is likely due to the propagation of retrograde and anterograde transport of growth signals sourced from the graft site. Collectively, growth improvement on the donor nerve, target muscle and motoneuron ultimately contribute to efficacious axonal regeneration and functional recovery. Thorough investigation of molecular peripheral nerve injury combinatorial strategies are required for the optimization of efficacious therapy and full functional recovery following ANA.Item Overview of pre-clinical and clinical studies targeting angiogenesis in pancreatic ductal adenocarcinoma(Elsevier, 2016) Craven, Kelly E.; Gore, Jesse; Korc, Murray; Department of Biochemistry and Molecular Biology, IU School of MedicineThe importance of angiogenesis in pancreatic ductal adenocarcinoma (PDAC) and its therapeutic potential have been explored in both pre-clinical and clinical studies. Human PDACs overexpress a number of angiogenic factors and their cognate high-affinity receptors, and anti-angiogenic agents reduce tumor volume, metastasis, and microvessel density (MVD), and improve survival in subcutaneous and orthotopic pre-clinical models. Nonetheless, clinical trials using anti-angiogenic therapy have been overwhelmingly unsuccessful. This review will focus on these pre-clinical and clinical studies, the potential reasons for failure in the clinical setting, and ways these shortcomings could be addressed in future investigations of angiogenic mechanisms in PDAC.Item The plasma level changes of VEGF and soluble VEGF receptor‐1 are associated with high‐altitude pulmonary edema(2018) Zhang, Shukun; Liu, Juanli; Jiang, Dongmei; Wuren, Tana; Ma, Siqing; Du, Yansheng; Wu, Shizheng; Neurology, School of MedicineHypoxia‐induced plasma levels of VEGF and sFlt‐1 are responsible for increased vascular permeability occurred in both brain and pulmonary edema. Currently, it remains unclear the exact roles of VEGF and sFlt‐1 in High Altitude Pulmonary Edema (HAPE) pathogenesis. In this study, plasma levels of VEGF and sFlt‐1 from 10 HAPE and 10 non‐HAPE subjects were measured and compared. The results showed that plasma levels of both VEGF and sFlt‐1 in HAPE patients were significantly increased as compared to the non‐HAPE group. Interestingly, increased plasma levels of these two protein factors were markedly reduced after treatments. As compared to VEGF, sFlt‐1 was much more affected by hypoxia and treatments, suggesting this factor was a key factor contributed to HAPE pathogenesis. Importantly, the ratio of sFlt‐1 and VEGF in group of either non‐HAPE or HAPE after recovery was significantly lower than the ratio in HAPE patients prior to treatments. Our findings suggested that sFlt‐1 was a key factor that involved in HAPE pathogenesis and the sFlt‐1/VEGF ratio could be used as a sensitive diagnostic marker for HAPE.Item Regulation of EVI5, VEGF and P53bp2 during Amphibian Limb Regeneration(Office of the Vice Chancellor for Research, 2013-04-05) Elkhatib, WiaamUnderstanding limb regeneration on a molecular level could lead to new methods of healing for humans, therefore revolutionizing current medical treatments. The axolotl salamander possesses capabilities of limb regeneration that are lost in the Xenopus laevis froglet. The hypothesized reason is that elevated levels of EVI5 (ecotropic viral integration site 5) binding protein allow the axolotl to regenerate by delaying the mitosis of dedifferentiated cells until they have established a blastema. VEGF (vascular endothelial growth factor) and P53bp2 (tumor protein 53 binding protein 2) genes also take part in this process by stimulating blood vessel formation and regulating apoptosis and cell growth in regenerated tissue. The objective of this study is to clone EVI5, VEGF, and P53BP2 cDNA that can be used to detect their mRNA transcripts during limb regeneration in the axolotl and Xenopus laevis. To accomplish this, RNA is extracted from axolotl and Xenopus laevis limb tissue using an RNeasy kit. Total RNA concentration is then measured spectrophotometrically. RT-PCR (reverse transcription polymerase chain reaction) is used to clone the cDNAs, which are identified by Agarose gel electrophoresis and later sequenced for verification. It took half a year to get high enough RNA concentrations from both species’ tissues and then clone the three genes. The EVI5 band size was determined to be about 200bps, VEGF about 370bps, and P53bp2 about 500bps using the Agarose gel electrophoresis, signifying successful gene cloning. The long-term goal is to determine the role these genes play in limb regeneration with the aim of applying that knowledge to new medical treatments.Item Weighted gene co-expression network analysis of colorectal patients to identify right drug-right target for potent efficacy of targeted therapy(2017-12-10) Tripathi, Anamika; Pradhan, Meeta; Wu, HuanmeiColon rectal cancer (CRC) is one of the most common cancers worldwide. It is characterized by the successive accumulation of mutations in genes controlling epithelial cell growth and differentiation leading to genomic in-stability. This results in the activation of proto-oncogene(K-ras), loss of tumor suppressor gene activity and ab-normality in DNA repair genes. Targeted therapy is a new generation of cancer treatment in which drugs attack targets which are specific for the cancer cell and are critical for its survival or for its malignant behavior. Survival of metastatic CRC patients has approximately doubled due to the development of new combinations of stan-dard chemotherapy, and the innovative targeted therapies, such as monoclonal antibodies against epidermal growth factor receptor (EGFR) or monoclonal antibodies against vascular endothelial growth factor (VEGFR).The study is to exhibit the need for right drug-right target and provides a proof of principle for potent efficacy of molecular targeted therapy for CRC. We have performed the weighted gene co-expression network analysis for three different patient cohort treated with different targeted therapy drugs. The results demonstrates the variation across different treatment regime in context of transcription factor networks. New significant tran-scription factors have been identified as potential biomarker for CRC cancer including EP300, STAT6, ATF3, ELK1, HNF4A, JUN, TAF1, IRF1, TP53, ELF1 and YY1. The results provides guidance for future omic study on CRC and additional validation work for potent biomarker for CRC.