Maspin has been shown to inhibit tumor cell invasion and metastasis in breast tumor cells. Maspin expression was detected in normal breast and prostate epithelial cells, whereas tumor cells exhibited reduced or no expression. However, the regulatory mechanism of maspin expression remains unknown. We report here a rapid and robust induction of maspin expression in prostate cancer cells (LNCaP, DU145, and PC3) and breast tumor cells (MCF7) following wild type p53 expression from an adenovirus p53 expression vector (AdWTp53). p53 activates the maspin promoter by binding directly to the p53 consensus-binding site present in the maspin promoter. DNA-damaging agents and cytotoxic drugs induced endogenous maspin expression in cells containing the wild type p53. Maspin expression was refractory to the DNA-damaging agents in cells containing mutant p53. These results, combined with recent studies of the tumor metastasis suppressor gene KAI1 and plasminogen activator inhibitor 1 (PAI1), define a new category of molecular targets of p53 that have the potential to negatively regulate tumor invasion and/or metastasis.Maspin was originally identified in normal breast epithelial cells (1). The maspin gene encodes a 42-kDa protein and belongs to the serine protease inhibitor (serpin) superfamily with tissue type plasminogen activator as the possible protease target (2). Maspin expression was detected in normal breast and prostate epithelial cells; however, tumor cells showed a decreased expression or absence of expression. Expression of maspin in breast tumor cells inhibit tumor cell invasion in vitro and tumor cell metastasis in vivo (1). Neutralization of maspin by an anti-maspin antibody abolished the invasion suppressive effect of conditioned medium from cultured breast myoepithelial cells on tumor cells (3). A recent report also suggests that the tumor suppressive effects of manganese-containing superoxide dismutase in human breast cancer cells could result from the up-regulation of maspin (4). Gamma linolenic acid, an essential fatty acid with anticancer properties, is reported to induce maspin expression and affect the motility of cancer cells (5). Transcriptional activity of maspin expression differed between prostate normal and tumor cells (6). These observations suggest that maspin expression plays important roles in regulating tumor cell invasion and metastasis. Thus, an understanding of the regulation of maspin expression is important in designing therapeutic agents for the cancer treatment.Molecular targets of p53, e.g. p53-regulated genes or p53-interacting proteins, have provided critical information central to the current understanding of the biochemical and biologic function of the p53 tumor suppressor gene. The function of p53 as check point protein is now well established (7). p53-regulated genes have also defined the role of p53 in apoptosis, hypoxia, and angiogenesis (8 -10). However, the downstream targets of p53 remain to be defined in the process of cancer cell invasion/metastasis. In our search for mole...

TMPRSS2-ERG gene fusion leading to the androgenic induction of the ERG proto-oncogene expression is a highly prevalent oncogenic alteration in prostate tumor cells. Prostate cancer is a multi-focal disease, and the origins as well as biological contribution of multiple cancer foci remain unclear with respect to prostate cancer onset or progression. To assess the role of TMPRSS2-ERG alteration in prostate cancer onset and/or progression, we have evaluated the status of fusion transcripts in benign glands, prostatic intraepithelial neoplasia (PIN) and multiple cancer foci of each prostate. Quantitative expression of TMPRSS2-ERG fusion type A and C transcripts was analyzed in benign, tumor and PIN areas, selected from whole-mount radical prostatectomy slides. TMPRSS2-ERG expression was correlated with clinicopathological features. Overall, 30 of 45 (67%) patients exhibited TMPRSS2-ERG fusion transcripts in at least one tumor focus. Of 80 tumor foci analyzed, 39 had TMPRSS2-ERG fusion (type A only: 30, type C only: 2, both types A and C: 7), with predominant detection of the TMPRSS2-ERG fusion type A (27/30, 90%) in the index tumors. Of 14 PIN lesions, 2 were positive for type A fusion. Frequent presence of the TMPRSS2-ERG in index tumors suggests critical roles of ERG alterations in the onset and progression of a large subset of prostate cancer. However, heterogeneity of the TMPRSS2-ERG detection in the context of multiple cancer foci and its frequency in PIN also support the role of other genomic alterations in the origins of prostate cancer.

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Methods to reduce mass shifts caused by space charge with mass-selective axial ejection from a linear quadrupole ion trap are investigated. For axial ejection, dipole excitation is applied to excite ions at q ≈ 0.85. The trapping radiofrequency (rf) voltage is scanned to bring ions of different m/z values into resonance for excitation. In the fringing field at the quadrupole exit, excited ions gain axial kinetic energy, overcoming the trapping potential, and are ejected from the trap. Space charge causes the frequencies of ion oscillation to decrease. Thus, greater rf voltages are required to bring ions into resonance for excitation and ejection, and the ions shift to higher apparent masses in a mass spectrum. At the same time, the peaks broaden, lowering resolution. The effects of injection q value, ejection q value, excitation amplitude, quadrupole dc voltages applied to the electrodes, applying an rf voltage to the exit lens, and scan speed, on mass shifts have been studied experimentally. Most experiments were done with only ions of protonated reserpine (m/z 609.3 and its isotopic peaks) in the trap. Some experiments were done with ions of protonated reserpine and ions of m/z 622 in the trap. In general, the mass shifts are reduced with higher ejection q values, higher excitation amplitudes, with quadrupole dc applied, and at higher scan speeds. The application of quadrupole dc appears to increase the ion cloud temperature, which lowers mass shifts. Thus, a proper choice of operating conditions can reduce, but not eliminate, mass shifts caused by space charge.

Purpose: A region on chromosome 8q24 was recently identified as a novel prostate cancer risk locus. Inherited variation in this region is associated with prostate cancer risk in the general population (21-58%), and specific alleles show a strong association in African-American men. This study was designed to evaluate associations between 8q24 risk alleles and clinical variables, such as pathologic stage, age at diagnosis, and recurrence, in a case series of African-American men.Experimental Design: Peripheral blood DNA samples from 114 African-American men with prostate cancer, including 106 who had undergone radical prostatectomy, were genotyped for six single-nucleotide polymorphisms on three 8q24 regions. The presence of these single-nucleotide polymorphisms was compared with clinicopathologic and follow-up data after radical prostatectomy.Results: The mean age of diagnosis and follow-up time were 57.4 (±8.9) years and 49.1 (±31.6) months, respectively. Patients carrying the Broad11934905 A risk allele, which is specific for African ancestry, were more likely to have a higher pathologic stage (pT 3-4 ) than individuals with the wild type (odds ratio, 4.48; 95% confidence interval, 1.42-14.14; P = 0.011). A trend toward increased frequency of and shorter time to biochemical recurrence was noted in patients with this risk allele on Kaplan-Meier unadjusted survival analysis (P = 0.076).Conclusions: The Broad11934905 polymorphism at 8q24, which is only found in people of African ancestry, is associated with an increase in non-organ-confined prostate cancer at prostatectomy. In addition, for those with this risk allele, there is a trend toward early biochemical recurrence that requires validation in larger studies. Cancer Epidemiol Biomarkers Prev; 19(1); 1-8. ©2010 AACR.