Global expression analysis of cancer/testis genes in uterine cancers reveals a high incidence of BORIS expression

Abstract Purpose: Cancer/testis (CT) genes predominantly expressed in the testis (germ cells) and generally not in other normal tissues are aberrantly expressed in human cancers. This highly restricted expression provides a unique opportunity to use these CTgenes for diagnostics, immunotherapeutic, or other targeted therapies. The purpose of this study was to identify those CT genes with the greatest incidence of expression in uterine cancers. Experimental Design: We queried the expression of known and putative CT gene transcripts (representing 79 gene loci) using whole genome gene expression arrays. Specifically, the global gene expressions of uterine cancers (n = 122) and normal uteri (n = 10) were determined using expression data from the Affymetrix HG-U133A and HG-U133B chips. Additionally, we also examined the brother of the regulator of imprinted sites (BORIS) transcript by reverse transcription-PCR and quantitative PCR because its transcript was not represented on the array. Results: Global microarray analysis detected many CT genes expressed in various uterine cancers; however, no individual CT gene was expressed in more than 25% of all cancers. The expression of the two most commonly expressed CT genes on the arrays, MAGEA9 (24 of 122 cancers and 0 of10 normal tissues) and Down syndrome critical region 8 (DSCR8)/MMA1 (16 if 122 cancers and 0 of 10 normal tissues), was confirmed by reverse transcription-PCR methods, validating the array screening approach. In contrast to the relatively low incidence of expression of the other CTgenes, BORIS expression was detected in 73 of 95 (77%) endometrial cancers and 24 of 31 (77%) uterine mixed mesodermal tumors. Conclusions: These data provide the first extensive survey of multiple CT genes in uterine cancers. Importantly, we detected a high frequency of BORIS expression in uterine cancers, suggesting its potential as an immunologic or diagnostic target for these cancers. Given the high incidence of BORIS expression and its possible regulatory role, an examination of BORIS function in the etiology of these cancers is warranted

Gene expression profiles derived from fine needle aspiration correlate with response to systemic chemotherapy in breast cancer

BACKGROUND: Drug resistance in breast cancer is a major obstacle to successful chemotherapy. In this study we used cDNA microarray technology to examine gene expression profiles obtained from fine needle aspiration (FNA) of primary breast tumors before and after systemic chemotherapy. Our goal was to determine the feasibility of obtaining representative expression array profiles from limited amounts of tissue and to identify those expression profiles that correlate with treatment response. METHODS: Repeat presurgical FNA samples were taken from six patients who were to undergo primary surgical treatment. Additionally, a group of 10 patients who were to receive neoadjuvant chemotherapy underwent two FNAs before chemotherapy (adriamycin 60 mg/m(2) and cyclophosphamide 600 mg/m(2)) followed by another FNA on day 21 after the first cycle. Total RNA was amplified with T7 Eberwine's procedure and labeled cDNA was hybridized onto a 7600-feature glass cDNA microarray. RESULTS: We identified candidate gene expression profiles that might distinguish tumors with complete response to chemotherapy from tumors that do not respond, and found that the number of genes that change after one cycle of chemotherapy was 10 times greater in the responding group than in the non-responding group. CONCLUSION: This study supports the suitability of FNA-derived cDNA microarray expression profiling of breast cancers as a comprehensive genomic approach for studying the mechanisms of drug resistance. Our findings also demonstrate the potential of monitoring post-chemotherapy changes in expression profiles as a measure of pharmacodynamic effect and suggests that these approaches might yield useful results when validated by larger studies

Intra and intermodular exchange interactions in bis(α-aminoisobutyrato)oxalamidodicopper(Aib-COCO-Aib)Cu₂

Magnetic susceptibility and electron paramagnetic resonance (EPR) spectra of exquisite two-dimensional supramolecular assembly of [bis(α-aminoisobutyrato)oxalamidodicopper](Aib-COCO-Aib)Cu2 were studied. The temperature dependent magnetic susceptibility studies reveal temperature dependency of the exchange coupling constant. Single crystal EPR studies both at X- and Q-bands show the two-dimensional nature of magnetic lattice and yield the weak intermodular exchange coupling constant in presence of strong intramodular exchange. The intermodular coupling is about five orders of magnitude smaller than the intramodular coupling but it produces a broadening and coalescence of the EPR lines. The temperature dependence of exchange coupling constant reflects dynamical properties of the crystal lattice

EPR-based oximetric imaging : a combination of single point-based spatial encoding and T1 weighting

Purpose: Spin-lattice relaxation time (T1)-weighted time-domain EPR oximetry is reported for in vivo applications using a paramagnetic probe, a trityl-based Oxo71. Methods: The R1 dependence of the trityl probe Oxo71 on pO2 was assessed using single point imaging (SPI) mode of spatial encoding combined with rapid repetition, similar to T1-weighted MRI, where R1 was determined from 22 repetition times ranging from 2.1–40.0 μs at 300 MHz. The pO2 maps of a phantom with three tubes containing 2 mM Oxo71 solutions equilibrated at 0%, 2%, and 5% oxygen were determined by R1 and apparent spin-spin relaxation rate (R2*) simultaneously. Results: The pO2 maps derived from R1 and R2* agreed with the known pO2 levels in the tubes of Oxo71. However, the histograms of pO2 revealed that R1 offers better pO2 resolution than R2* in low pO2 regions. The standard deviations of pixels at 2% pO2 (15.2 mmHg) were about 5 times lower in R1-based estimation than R2*-based estimation (mean ± SD: 13.9 ± 1.77 mmHg and 18.3 ± 8.70 mmHg, respectively). The in vivo pO2 map obtained from R1-based assessment displayed a homogeneous profile in low pO2 regions in tumor xenografts, consistent with previous reports on R2*-based oximetric imaging. The scan time to obtain the R1 map can be significantly reduced using three repetition times ranging from 4.0‒12.0 μs. Conclusion: Using the SPI modality, R1-based oximetry imaging with useful spatial and oxygen resolutions for small animals was demonstrated

Estimation of tumor microvessel density by MRI using a blood pool contrast agent

Recognition of importance of angiogenesis to tumor growth, metastasis, and treatment outcome has led to efforts to develop non-invasive methods for longitudinal monitoring of tumor microvasculature. We describe a steadystate MRI technique to determine absolute blood volume (BV) as a marker of microvascular density with improved spatial and temporal resolution using an ultra small super paramagnetic iron oxide (USPIO). A noise reduction scheme for BV imaging was also proposed based on weighting factors derived by pre-contrast signal level as an adjustable additive constant. Gradient echo sequence was used for BV imaging with MRI at 7T. Optimal imaging conditions (USPIO dose and echo time) were determined by USPIO dose-dependent studies ex vivo and in vivo. Improved analysis strategies were at first applied for cerebral BV estimation in mice, which were found in good agreement with the literature values. These methods were then used to determine tumor BV in mice. The optimal concentration of USPIO for BV estimates was found to range from 3.6 to 4.48 mM (estimated as Fe concentration) in ex vivo experiments corresponding to an in vivo dosage of 215-287 umol/kg body weight, whereas a USPIO dose of 287 umol/kg leads to higher cerebral BV estimate in vivo than the reported values. Application of the BV imaging method to evaluation of anti-angiogenic effect of Sunitinib in squamous cell carcinoma (SCC) tumor bearing mice revealed ~46% reduction in tumor BV 4 days after start of Sunitinib treatment. The results show that the MRI approach using USPIO yields high-resolution absolute BV images and the method can be conveniently applied to monitor longitudinal tumor microvessel density changes as a function of growth or in response to treatment

Pharmacological targeting of polyamine and hypusine biosynthesis reduces tumour activity of endometrial cancer

Endometrial cancer (EC) is a common and deadly cancer in women and novel therapeutic approaches are urgently needed. Polyamines (putrescine, spermidine, spermine) are critical for mammalian cell proliferation and MYC coordinately regulates polyamine metabolism through ornithine decarboxylase (ODC). ODC is a MYC target gene and rate-limiting enzyme of polyamine biosynthesis and the FDA-approved anti-protozoan drug α-difluoromethylornithine (DFMO) inhibits ODC activity and induces polyamine depletion that leads to tumour growth arrest. Spermidine is required for the hypusine-dependent activation of eukaryotic translation initiation factors 5A1 (eIF5A1) and 5A2 (eIF5A2) and connects the MYC/ODC-induced deregulation of spermidine to eIF5A1/2 protein translation, which is increased during cancer cell proliferation. We show that eIF5A1 is significantly upregulated in EC cells compared to control cells (p=.000038) and that combined pharmacological targeting of ODC and eIF5A hypusination with cytostatic drugs DFMO and N1-guanyl-1,7-diaminoheptane (GC7), respectively, reduces eIF5A1 activation and synergistically induces apoptosis in EC cells. In vivo, DFMO/GC7 suppressed xenografted EC tumour growth in mice more potently than each drug alone compared to control (p=.002) and decreased putrescine (p=.045) and spermidine levels in tumour tissues. Our data suggest DFMO and GC7 combination therapy may be useful in the treatment or prevention of EC

EPR‐based oximetric imaging: a combination of single point‐based spatial encoding and T1 weighting

Purpose: Spin‐lattice relaxation rate (R1)‐based time‐domain EPR oximetry is reported for in vivo applications using a paramagnetic probe, a trityl‐based Oxo71. Methods: The R1 dependence of the trityl probe Oxo71 on partial oxygen pressure (pO2) was assessed using single‐point imaging mode of spatial encoding combined with rapid repetition, similar to T1‐weighted MRI, for which R1 was determined from 22 repetition times ranging from 2.1 to 40.0 μs at 300 MHz. The pO2 maps of a phantom with 3 tubes containing 2 mM Oxo71 solutions equilibrated at 0%, 2%, and 5% oxygen were determined by R1 and apparent spin–spin relaxation rate (R2*) simultaneously. Results: The pO2 maps derived from R1 and R2* agreed with the known pO2 levels in the tubes of Oxo71. However, the histograms of pO2 revealed that R1 offers better pO2 resolution than R2* in low pO2 regions. The SDs of pixels at 2% pO2 (15.2 mmHg) were about 5 times lower in R1‐based estimation than R2*‐based estimation (mean ± SD: 13.9 ± 1.77 mmHg and 18.3 ± 8.70 mmHg, respectively). The in vivo pO2 map obtained from R1‐based assessment displayed a homogeneous profile in low pO2 regions in tumor xenografts, consistent with previous reports on R2*‐based oximetric imaging. The scan time to obtain the R1 map can be significantly reduced using 3 repetition times ranging from 4.0 to 12.0 μs. Conclusion: Using the single‐point imaging modality, R1‐based oximetry imaging with useful spatial and oxygen resolutions for small animals was demonstrated

EPR

Purpose: Spin-lattice relaxation time (T1)-weighted time-domain EPR oximetry is reported for in vivo applications using a paramagnetic probe, a trityl-based Oxo71. Methods: The R1 dependence of the trityl probe Oxo71 on pO2 was assessed using single point imaging (SPI) mode of spatial encoding combined with rapid repetition, similar to T1-weighted MRI, where R1 was determined from 22 repetition times ranging from 2.1–40.0 μs at 300 MHz. The pO2 maps of a phantom with three tubes containing 2 mM Oxo71 solutions equilibrated at 0%, 2%, and 5% oxygen were determined by R1 and apparent spin-spin relaxation rate (R2*) simultaneously. Results: The pO2 maps derived from R1 and R2* agreed with the known pO2 levels in the tubes of Oxo71. However, the histograms of pO2 revealed that R1 offers better pO2 resolution than R2* in low pO2 regions. The standard deviations of pixels at 2% pO2 (15.2 mmHg) were about 5 times lower in R1-based estimation than R2*-based estimation (mean ± SD: 13.9 ± 1.77 mmHg and 18.3 ± 8.70 mmHg, respectively). The in vivo pO2 map obtained from R1-based assessment displayed a homogeneous profile in low pO2 regions in tumor xenografts, consistent with previous reports on R2*-based oximetric imaging. The scan time to obtain the R1 map can be significantly reduced using three repetition times ranging from 4.0‒12.0 μs. Conclusion: Using the SPI modality, R1-based oximetry imaging with useful spatial and oxygen resolutions for small animals was demonstrated