Expression of Cytosolic and Mitochondrial Superoxide Dismutases: Their Role in the Chemoresistance of Malignant Melanoma

269 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.In summary, MM cells that are exposed to sublethal doses of ROS generating chemotherapeutic agents are able to modulate antioxidant defenses as an adaptive response. By upregulating Mn-SOD without commensurate increase in catalase activities, an imbalance in oxidant processing occurs. This imbalance in the antioxidant defense system results in accumulation of peroxides, which can act as secondary messengers to enhance cell survival pathways.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Initiation of prostate cancer in mice by Tp53R270H: evidence for an alternative molecular progression

SUMMARY Tp53 mutations are common in human prostate cancer (CaP), occurring with a frequency of ∼30% and ∼70% in localized and metastatic disease, respectively. In vitro studies have determined several common mutations of Tp53 that have specific gain-of-function properties in addition to loss of function, including the ability to promote castration-resistant (CR) growth of CaP cells in some contexts. To date, a lack of suitable mouse models has prohibited investigation of the role played by Tp53 mutations in mediating CaP progression in vivo. Here, we describe the effects of conditional expression of a mutant Tp53 (Tp53R270H; equivalent to the human hotspot mutant R273H) in the prostate epithelium of mice. Heterozygous “Tp53LSL-R270H/+” [129S4(Trp53tm3Tyj)] and “Nkx3.1-Cre” [129S(Nkx3-1tm3(cre)Mms)] mice with prostate-specific expression of the Tp53R270H mutation (p53R270H/+ Nkx3.1-Cre mice) were bred onto an FVB/N background via speed congenesis to produce strain FVB.129S4(Trp53tm3Tyj/wt); FVB.129S(Nkx3-1tm3(cre)Mms/wt) and littermate genotype negative control mice. These mutant mice had significantly increased incidences of prostatic intraepithelial neoplasia (PIN) lesions, and these appeared earlier, compared with the Nkx3.1 haploinsufficient (Nkx3.1-Cre het) littermate mice, which did not express the Tp53 mutation. PIN lesions in these mice showed consistent progression and some developed into invasive adenocarcinoma with a high grade, sarcomatoid or epithelial-mesenchymal transition (EMT) phenotype. PIN lesions were similar to those seen in PTEN conditional knockout mice, with evidence of AKT activation concomitant with neoplastic proliferation. However, the invasive tumor phenotype is rarely seen in previously described mouse models of prostatic neoplasia. These data indicate that the Tp53R270H mutation plays a role in CaP initiation. This finding has not previously been reported. Further characterization of this model, particularly in a setting of androgen deprivation, should allow further insight into the mechanisms by which the Tp53R270H mutation mediates CaP progression

A serum glycomics approach to breast cancer biomarkers

Because the glycosylation of proteins is known to change in tumor cells during the development of breast cancer, a glycomics approach is used here to find relevant biomarkers of breast cancer. These glycosylation changes are known to correlate with increasing tumor burden and poor prognosis. Current antibody-based immunochemical tests for cancer biomarkers of ovarian (CA125), breast (CA27.29 or CA15-3), pancreatic, gastric, colonic, and carcinoma (CA19-9) target highly glycosylated mucin proteins. However, these tests lack the specificity and sensitivity for use in early detection. This glycomics approach to find glycan biomarkers of breast cancer involves chemically cleaving oligosaccharides (glycans) from glycosylated proteins that are shed or secreted by breast cancer tumor cell lines. The resulting free glycan species are analyzed by MALDI-FT-ICR MS. Further structural analysis of the glycans can be performed in FTMS through the use of tandem mass spectrometry with infrared multiphoton dissociation. Glycan profiles were generated for each cell line and compared. These methods were then used to analyze sera obtained from a mouse model of breast cancer and a small number of serum samples obtained from human patients diagnosed with breast cancer or patients with no known history of breast cancer. In addition to the glycosylation changes detected in mice as mouse mammary tumors developed, glycosylation profiles were found to be sufficiently different to distinguish patients with cancer from those without. Although the small number of patient samples analyzed so far is inadequate to make any legitimate claims at this time, these promising but very preliminary results suggest that glycan profiles may contain distinct glycan biomarkers that may correspond to glycan "signatures of cancer.

Efficacy and Mechanism of Angiotensin II Receptor Blocker Treatment in Experimental Abdominal Aortic Aneurysms

<div><h3>Background</h3><p>Despite the importance of the renin-angiotensin (Ang) system in abdominal aortic aneurysm (AAA) pathogenesis, strategies targeting this system to prevent clinical aneurysm progression remain controversial and unproven. We compared the relative efficacy of two Ang II type 1 receptor blockers, telmisartan and irbesartan, in limiting experimental AAAs in distinct mouse models of aneurysm disease.</p> <h3>Methodology/Principal Findings</h3><p>AAAs were induced using either 1) Ang II subcutaneous infusion (1000 ng/kg/min) for 28 days in male ApoE^−/− mice, or 2) transient intra-aortic porcine pancreatic elastase infusion in male C57BL/6 mice. One week prior to AAA creation, mice started to daily receive irbesartan (50 mg/kg), telmisartan (10 mg/kg), fluvastatin (40 mg/kg), bosentan (100 mg/kg), doxycycline (100 mg/kg) or vehicle alone. Efficacy was determined via serial <em>in vivo</em> aortic diameter measurements, histopathology and gene expression analysis at sacrifice. Aortic aneurysms developed in 67% of Ang II-infused ApoE^−/− mice fed with standard chow and water alone (n = 15), and 40% died of rupture. Strikingly, no telmisartan-treated mouse developed an AAA (n = 14). Both telmisartan and irbesartan limited aneurysm enlargement, medial elastolysis, smooth muscle attenuation, macrophage infiltration, adventitial neocapillary formation, and the expression of proteinases and proinflammatory mediators. Doxycycline, fluvastatin and bosentan did not influence aneurysm progression. Telmisartan was also highly effective in intra-aortic porcine pancreatic elastase infusion-induced AAAs, a second AAA model that did not require exogenous Ang II infusion.</p> <h3>Conclusion/Significance</h3><p>Telmisartan suppresses experimental aneurysms in a model-independent manner and may prove valuable in limiting clinical disease progression.</p> </div

Influence of drug treatment on inflammatory gene expression.

<p>Aortic mRNA expression levels (fold expression) as a function of Ang II infusion (left column) and drug treatment status. Nonparametric Mann-Whiteny test, <i>*P</i><0.05 and <i>**P</i><0.01.</p

Effect of drug treatment on systolic blood pressure.

<p><b>A:</b> Dot plot graphs show plasma drug levels in individual Ang II-infused ApoE^−/− mice receiving each drug treatment. Horizontal line in each graph indicates mean drug concentration from 10–14 mice in each group. <b>B:</b> Effect of telmisartan, irbesartan, doxycycline and fluvastatin on systolic blood pressure in ApoE^−/− mice 14 and 28 days after Ang II infusion. <b>C:</b> Effect of bosentan on systolic blood pressure in ApoE^−/− mice 7, 14, 21 and 28 days after Ang II infusion. <b>D:</b> Effect of telmisartan on systolic blood pressure in C57BL/6J mice 7 and 14 days after PPE infusion. Data in B–D are given as mean ± standard derivation for each group. Data in B and C were obtained from separate experiments, each with its own control group. In all experiments, two-way ANOVA followed by Newman-Keuls post-test, *<i>P</i><0.05 or <i>**P</i><0.01 compared to control group at same time points. n = 10–15 (A–C) or 7–9 (D) mice in each group.</p

Effect of telmisartan, irbesartan, fluvastatin and doxycycline on aortic diameters of Ang II-infused ApoE^−/− mice.

<p>Noninvasive transabdominal ultrasonography was used to measure suprarenal aortic diameters in individual mice prior to drug treatment (day -7), on the Ang II infusion day (day 0), and 3, 7, 14, 21 and 28 days after Ang II infusion. Data are given as mean ± standard derivation of the aortic diameters for all groups, with all dimensions listed in units of mm. Number of mice in each group is shown in the parenthesis. Two-way ANOVA analysis followed by Newman-Keuls post-test, <i>*P</i><0.05 and <i>**P</i><0.01 compared to the control group at same measurement day.</p

Antihypertension-independent effect of telmisartan on AAAs. A–C:

<p>Effect of bosentan on AAA incidence (A), mortality (B) and suprarenal aortic diameters (C) in Ang II-infused ApoE^−/− mice. <b>D:</b> Effect of telmisartan on infrarenal aortic diameters in C57BL/6J mice after PPE infusion. Data in B and D are given as mean ± standard derivation for each group. Two-way ANOVA followed by Newman-Keuls post-test, *<i>P</i><0.05 or <i>**P</i><0.01 compared to the control group at corresponding time points. n = 10–15 (A–C) or 7–9 (D) mice in each group.</p

Influence of drug treatment on AAA incidence and mortality.

<p><b>A–C:</b> Ultrasound images representing an intact aorta (A), an aneurysmal aorta without dissection (B) and an aneurysmal aorta with medial dissection (C). <b>D, E:</b> AAA incidence (D) and mortality (E) in Ang II-infused mice treated with telmisartan, irbesartan, fluvastatin or doxycycline. Kaplan-Meier analysis, <i>*P</i><0.05 and <i>**P</i><0.01 compared to control group, n = 14–15 mice in each group.</p