Citations

Abstract Objective: This paper introduces an alternative non-invasive and non-ionizing breast imaging tool called vibro-acoustography (VA). This method is based on low-frequency harmonic vibrations induced in the object by the radiation force of ultrasound. Contrast in Vibro-acoustography images represent several properties of the object, including the dynamic characteristics at the audio frequency and scattering and absorption properties at the ultrasound frequency. X-ray mammography and ultrasound are the main imaging modality used today for detection of breast lesions. X-ray mammography, however, is ionizing and its sensitivity is greatly reduced in dense breasts. Ultrasound images suffer from speckles or other or artifact that prevents the physician from delineating the mass lesion from the background tissue. Hence, VA may be used as a stand-alone imaging device or as a tool to provide supplementary information to other existing imaging modalities. Materials & Methods: Matching vibro-acoustography and mammography images of human breast are acquired using a combined mammography/vibro-acoustography machine. Images of various types of breast masses are investigated and their characteristics features are compared. Image features, such as lesion borders, interior texture, and speculation pattern, are studied. Results: Resulting images show soft tissue structures, breast lesions and microcalcifications within breast with high contrast, high resolution, and no speckles. The results have been verified using x-ray mammograms of the breast. Vibro-acoustography images demonstrate that calcified masses normally show sharp borders, benign non-calcified masses have smooth texture, and, in some cases, malignant masses are characterized with spiculation. Conclusion: The encouraging results which are based on the data collected from an ongoing study indicate that the above mentioned image features may be used for differentiation of breast masses and suggest that further development of vibro-acoustography technology may lead to a new clinical tool for various imaging applications. Work supported in part by Grant CA121579-01A1from NIH and Grant BCTR#0504550 from Susan G. Komen Breast Cancer Foundation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4047. doi:1538-7445.AM2012-4047

Abstract SHP2 is a protein tyrosine phosphatase encoded by the PTPN11 gene. SHP2 is normally auto-inhibited by its regulatory N-SH2 domain. It is activated by several receptor tyrosine kinases and positively regulates the RAS/ERK and other signaling pathways by mechanisms that remain incompletely defined. Furthermore, gain-of-function activating SHP2 mutants have been found in human hematologic malignancies and solid tumors, including lung, colon, and prostate cancer. Previous studies have demonstrated the oncogenic activity of gain-of-function SHP2 mutants in the hematopoietic system. To investigate the biological functions of mutant SHP2 in vivo, we generated transgenic mice harboring a tetO-SHP2E76K transgene for tetracycline-inducible expression of the constitutively active SHP2E76K mutant. This allows us to examine the roles of the cancer-associated, Glu-76 mutant SHP2 in various tissues in bitransgenic mice. tetO-SHP2E76K mice were crossed with CCSP-rtTA or SPC-rtTA mice for inducible expression of SHP2E76K in the lung type II pneumocytes. Elevated levels of active Erk1/2 and Src were detected in the lungs of bitransgenic mice induced with doxycycline. Focal hyperplasia of bronchioloalveolar epithelial cells was observed within one month of doxycycline induction in bitransgenic mice, which progressed to more extensive atypical adenomous hyperplasia and adenoma after six months. These results suggest that Shp2 is a proto-oncogene of lung carcinoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4005. doi:1538-7445.AM2012-4005

Abstract Background: Cyr61, also known as CCN1, is a survival and pro-angiogenic factor overexpressed in invasive breast tumors that promotes tumorigenicity. We investigated whether Cyr61 plays important roles in breast cancer and evaluated its potential role as a chemotherapeutical target. Methods: We analyzed Cyr61 expression in a tissue microarray from breast cancer patients consisting of primary breast carcinomas and recurrences. Cyr61 was silenced in the metastatic MDA-MB-231 cells using a Cyr61-specific short hairpin RNA (Cyr61-shRNA). The effect of Cyr61 silencing on anchorage dependent- and independent growth, migration and invasiveness was characterized in vitro. The mechanism by which Cyr61 mediates the proliferation effects was investigated. The effect of Cyr61 in tumor growth was investigated in a subcutaneous orthotopic tumor xenograft model and the histological and immunohistochemical analysis ware performed. All statistical tests were two-sided. Results: Cyr61 is highly expressed in about 47% of the metastatic breast cancer patients analyzed. The expression is higher in the recurrences than in the primary tumors. Silencing Cyr61 inhibits cell proliferation, prevents anchorage-dependent and -independent growth, and suppresses the invasive potential of the cells by inhibiting migration in vitro. We also found that silencing Cyr61 decreases the expression of its own receptor αvβ3, and decreases its signaling activities. Remarkably, the in vivo studies showed that after silencing Cyr61 the tumor burden is significantly decreased and there is poor vascularized compared to control tumors. Conclusions: Our findings provide the proof of concept that Cyr61 is a key promoter of breast cancer tumorigenicity. It should be considered as a potential target for developing therapies to breast cancers patients that overexpress Cyr61. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1846. doi:1538-7445.AM2012-1846

Abstract Background: Colorectal cancer (CRC) is a molecularly heterogeneous disease. Three molecular pathways (traditional, serrated and alternate) have been recently proposed based on integrated combinations of microsatellite instability (MSI), CpG island methylation phenotype (CIMP), BRAF mutation, and KRAS mutation status (Gastroenterol 2010;138:2088-2100). To our knowledge, clinicopathologic associations with these CRC pathways have not been previously described. Methods: Data and tissue resources were obtained from the population-based Iowa Women's Health Study, which recruited 41,836 randomly selected women, ages 55-69 years, at study entry (1986). Incident CRC cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were collected from 732 CRC cases diagnosed through 12/31/2002. Established laboratory methods were used to characterize CRC cases by MSI (MSS/MSI-L or MSI-H), CIMP (neg, low, or high), BRAF mutation (wt or mut), and KRAS mutation (wt or mut) status. Molecular pathways were defined as: traditional (MSS/MSI-L, CIMP-neg, BRAF wt, and KRAS wt); serrated (any MSI, CIMP-high, BRAF mut, and KRAS wt), alternate (MSS/MSI-L, CIMP-low, BRAF wt, and KRAS mut), or other pathway. Chi-square tests and analyses of variance were used to compare clinicopathologic features at CRC presentation (age, anatomic subsite, tumor grade, and SEER stage) across the molecular pathways. Results: Comlete and informative MSI, CIMP, BRAF and KRAS data were obtained for 491/732 (67%) CRC cases. Clinicopathologic associations are shown in the Table. Conclusions: These data suggest that distributions of age at diagnosis, subsite, and tumor grade, but not SEER stage, differ across the traditional, serrated, and alternate carcinogenic pathways, which may have implications for molecularly-targeted CRC prevention and/or therapy strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5518. doi:1538-7445.AM2012-5518

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is a precursor to multiple myeloma and related diseases. The majority of MGUS cases are characterized by the expression of immunoglobulin heavy chain (IgH); however, approximately one-fifth of MGUS cases do not present with IgH expression. These individuals have light chain MGUS (LC-MGUS), a precursor to light-chain MM (LC-MM). LC-MGUS is characterized by an absence of IgH and an abnormal free light chain ratio (FLC-R), indicating excessive expression of either κ or ≤ free light chains. LC-MGUS has a prevalence of 0.8% in the general population over the age of 50, as compared with a prevalence of 3.2% for heavy-chain MGUS (HC-MGUS) (Dispenzieri, 2010). There is currently little understanding of the association between family history of HC-MGUS or multiple myeloma (MM) and LC-MGUS. We investigated whether the prevalence of LC-MGUS is elevated in first-degree relatives of patients with either HC-MGUS or MM. HC-MGUS probands expressed IgH and were recruited through a population-based study of Olmsted County residents; MM probands consisted of both HC-MM and LC-MM and were recruited through the Mayo Clinic Hematology practice. Serum samples were collected from first-degree relatives of probands older than 40 years of age and subjected to electrophoresis, immunofixation, and free light chain assay. Prevalence of LC-MGUS was calculated in all first-degree relatives combined, and in relatives from both HC-MGUS and MM families separately. We compared the prevalence in family members to that in a well-defined Olmsted County, MN cohort (Dispenzieri, 2010) of patients aged 50 and over. A total 911 relatives of 232 MM and 97 MGUS patients were studied. LC-MGUS was detected in 17/911 (1.9%) relatives, for an age- and sex-adjusted prevalence of 1.7% (95% CI, 0.9% to 2.6%). Prevalence among relatives of MM probands (age- and sex- adjusted rate 2.1%; 95% CI, 1.0% to 3.2%) was higher than among relatives of MGUS probands (age- and sex- adjusted rate 0.6%; 95% CI, 0.0%-1.6%). There was an increased risk of LC-MGUS in relatives compared to the reference population which was predominantly due to the increased risk among relatives of MM probands (risk ratio=3.4, 95% CI 2.0, 5.51) as opposed to relatives of MGUS probands (risk ratio=1.1, 95% CI, 0.3 to 4.5). Among MM probands, there was no significant difference between the prevalence increase in relatives of the 32 probands with LC-MM and that of the relatives of the 200 probands with HC-MM (3.8 vs 3.3, ratio=1.2, 95% CI: 0.3-5.1, p=0.85). We conclude that the prevalence of LC-MGUS is significantly higher among first degree family members of all MM probands compared to the general population. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5485. doi:1538-7445.AM2012-5485

Abstract Introduction: Only few genetic studies have been performed in PCNSL, partly due to the rarity of the tumors and the limited amount of available tissue. Unlike nodal DLBCL, PCNSL is poorly understood in terms of its precise histogenetic origin and molecular pathogenesis. It is still a matter of debate whether PCNSL differs from nodal DLBCL with respect to their molecular features and pathogenesis and also if there is a genomic signature PCNSL-specific. Materials and Methods: To determine the pattern of genetic alterations, 17 immunocompetent (EBV-, HIV-) PCNSL were analyzed by aCGH. Seven cases were analyzed using fresh tumor samples and 10 using formalin-fixed paraffin embedded (FFPE) tissues. B-cell differentiation status was characterized by immunostains for CD10, MUM-1, and BCL-6. The aCGH profile from PCNSL cases was compared with aCGH data obtained from 59 nodal DLBCL. Results: We found a complex karyotype with a median of 21 copy-number abnormalities (CNA) per case (range 10-49). Overall, 18 regions (10 losses and 8 gains) were affected in >20% of cases. Loss of 9p21 (CDKN2A) was the commonest CNA (82% of cases). Other common CNAs were loss of 6q23.3 (TNFAIP3; 59%), 6p21 (HLA genes; 53%), 6q21 (PRDM1; 47%) and gain of 12q21-q24 (53%), 7q21-q31 (35%) and 19q13 (35%). Five novel recurrent focal CNAs were found in PCNSL; loss of 3p21.31, 3q26.32, 10p15.3-p14, 12q24.31 and 16q12.1-q21 (29% of cases each). All of them, excluding –16q12.1-q21, were found either in less than 5% or absent in nodal DLBCL, thus suggesting to be unique to PCNSL. Recurrent homozygous deletions were found in CDKN2A, TMEM30A, TOX and CD58, the latter two involved in T-cell development and activation. CD58 was also recurrently affected by small focal deletions in the Ig-like C2-type domain. Furthermore, DNA sequencing analysis showed missense mutations in the Toll/IL-1 receptor domain of MYD88 in 35% of PCNSLs. Another 34 genes, including B2M, ETV6, MHC class II genes, PRDM1, and TNFRSF10A were homozygously deleted. Bioinformatics analysis including the most commonly affected genes showed an enrichment of networks associated with immune response, NF-kB pathway, proliferation, regulation of the apoptosis and lymphocyte differentiation and activation. Conclusions: We showed evidence of a highly complex genome and identified a subset of genes with potential relevance in PCNSL pathogenesis. The genomic profile described here reinforces the existence of a specific molecular signature in PCNSL, thus helping to genetically differentiate this entity from the nodal DLBCL and related lymphomas. Additionally, the results obtained from FFPE samples are encouraging and larger archival tissue collections can now be analyzed in order to complement the still fragmented knowledge we have of the genetic basis of the disease. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5081. doi:1538-7445.AM2012-5081

Abstract Previous epidemiological studies have suggested that African Americans (AA) are twice as likely to be diagnosed with and to die from Multiple Myeloma (MM) as compared to European Americans (EA). In recent years, however, mortality rates have become more comparable between these groups. Although socioeconomic factors could play a major role to this potential disparity, biological factors may also be responsible for influencing these differences in either incidence and/or mortality. Here we examined a multi-ethnic cohort of MM tumors to assess potential differences in the frequency of molecular events in tumors derived from either African American (AA) or European American (EA) patients. First, we compared the frequency of 14q32 translocation breakpoints at the IgH locus among a series of data from 115 AA MM patients from three studies and EA MM from the Eastern Cooperative Oncology Group (ECOG). Furthermore, we analyzed matching genome-wide copy number and transcriptional data among 47 AA MM tumors and 196 EA MM tumors to determine differences in the frequency of molecular events in tumors from these populations. Univariate analyses were conducted using the Fisher's Exact Test and p-values were calculated to measure statistical significance. We observed statistically significant differences in the frequency of IgH translocations and somatic copy number alterations. Although we did not detect differences for specific translocation subtypes, we saw a statistically significant difference in the overall frequency of IgH translocations between the two groups, which occurred more frequently in EA patients (p = 0.032). When assessing genomic copy number events previously shown to be associated with poor outcome in MM, chromosome 13 monosomy was more frequent in hyperdiploid MM from AA patients and significant after correcting for multiple testing using the Bonferoni correction method (p = 0.001). Moreover, when using the Benjamini-Hochberg multiple testing correction method, chromosome 13 monosomy remained significantly different among hyperdiploid AA patients (p = 0.0121). Chromosome 1q amplification was also significant among hyperdiploid tumors from EA patients when using this correction method (p = 0.036). No differences in the frequency of hyperdiploid status or gene expression-based subtypes were detected when comparing tumors from AA and EA patients. Our study represents the first comprehensive assessment of the frequency and distribution of molecular alterations in MM tumors from both AA and EA patients and could help shed light on possible biological features associated with population differences in incidence and outcome in MM. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5064. doi:1538-7445.AM2012-5064

Abstract MicroRNAs (miRNAs) play an important role in a variety of physiological processes as well as pathophysiological processes, including cancinogenesis. This study was to identify a distinct miRNA expression signature for cervical intraepithelial neoplasia (CIN) and to reveal individual miRNAs that may be involved in the development of cervical carcinoma. Expression profiling using quantitative real-time RT-PCR of 202 miRNAs was performed on micro-dissected high-grade CIN (CIN 2/3) tissues as compared to normal cervical epithelium. The expression of 12 miRNAs including miR-518a, miR-34b, miR-34c, miR-20b, miR-338, miR-9, miR-512-5p, miR-424, miR-345, miR-10a, miR-193b and miR-203 were significantly different between high-grade CIN and normal epithelium. This miRNA signature was further validated by an independent set of high-grade CIN tissue. The same characteristic signature can also be used to distinguish cervical squamous cell carcinoma (SCC) from normal controls. Target prediction analysis revealed that these dysregulated miRNAs control the apoptosis signaling pathway and cell cycle regulation. These findings contribute to understanding of the pathogenesis of cervical carcinoma at the molecular level. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5047. doi:1538-7445.AM2012-5047

Abstract The Yin Yang 1 (YY1) transcription factor is a member of Polycomb protein family, with important roles in development, differentiation, replication and cell proliferation. While YY1 expression is correlated with survival in serous ovarian cancer, its role in chemotherapeutic agent-mediated cytotoxicity is not known. Immunoblot analysis revealed that YY1 is highly expressed in ovarian cancer cell lines, but not in immortalized ovarian surface epithelial (OSE) cell lines, suggesting a possible role of YY1 in ovarian carcinogenesis. shRNA mediated stable downregulation of YY1 resulted in inhibition of proliferation by CyQuant assay in SKOV3 and SKOV3ip cells. While YY1 downregulation increased the sensitivity against paclitaxel in both cell lines compared to nontargeted cells (NTC) as determined by MTT and clonogenic assays, it had no effect on sensitivity to cisplatin-mediated cytotoxicity. YY1 downregulated clones treated with paclitaxel resulted in an increase in cleavage of poly (ADP-ribose) polymerase and caspase-3/7 activity compared to NTC clones treated with it in SKOV3 and SKOV3ip1 cells. To determine the mechanism of paclitaxel sensitivity modulated by YY1, we performed cell cycle analysis and determined the expression of microtubules at protein level. Cell cycle analysis showed that downregulation of YY1 decreased the proportion of G0/G1 phase with corresponding increase in cells accumulating both S and G2/M phases in SKOV3 and SKOV3ip1 cells. Using nocodazole which synchronizes cells into mitotic phase, we found that blocking mitotic exit by YY1 knockdown slowed the cyclin B1 proteolysis, thus allowing more time for death initiation by paclitaxel. Immunoblot analysis showed that downregulation of YY1 increased the acetylation of alpha-tubulin and attenuated betaIII-tubulin expression compared to NTC cells. Immunoprecipitation and immunofluorescence assays revealed that YY1 interacts with HDAC6 which deacetylates alpha-tubulin and these proteins co-localized in mitotic phase, suggesting that dysfunction of HDAC6 by downregulation of YY1 could lead to microtubules stabilization, resulting in the paclitaxel-induced apoptosis by blocking mitotic exit. Moreover, nude mice bearing xenografts with stable downregulation of YY1 in SKOV3ip1 were more sensitive to paclitaxel-induced cytotoxicity compared to xenografts of NTC cells. Additionally immunohistchemical staining showed a decrease in betaIII-tubulin expression in tumor of YY1 downregulated clones compared to that of NTC clones. Collectively, these results indicate that YY1 acts as a modulator of microtubules expression and might be therapeutically targeted against epithelial ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4960. doi:1538-7445.AM2012-4960

Abstract Motivation: Overexpression of HER2 (the product of the ERBB2 gene) occurs in about 15% of all breast tumors. We have undertaken to use next generation transcriptome sequencing technology to identify genomic features that are unique to HER2+ tumors. Interactome mapping was then used to integrate the genes associated with these features into a transcriptome landscape model, with a view towards identifying nodes of interaction that might be targeted in HER2+ tumors. Methods: We performed 50nt paired-end RNA-sequencing for 24 breast tumors: 8 each HER2+, ER+, triple negatives (TN). In addition to breast adenocarcinomas, we also sequenced 8 early passage non-transformed HMEC cell lines as normal controls. Reads from RNA sequencing were aligned to the genome and exon junctions using TopHat software. Gene counts were summarized and annotations were performed using our in-house programs. Tukey's test was used to obtain genes or transcripts that are specific to HER2 tumor group compared to other tumors/normal. A combination of bioinformatics softwares and algorithms were used to identify SNVs. Results: Only 13527 genes with median gene count greater than 16 reads in at least one of the 4 groups were considered for differential gene expression and splicing analysis. Some 696 genes were differentially expressed in HER2+ tumors compared to ER+, TN tumors and HMECs. We identified 272 alternately spliced transcripts for which the HER2+ tumors exhibited a mean transcript expression ratio significantly different from the means of other tumor groups. We also identified 4735 expressed single nucleotide variants that are uniquely associated with HER2+ tumors compared to other tumors/normal groups. Among these 3579/4735 sequence polymorphisms were not present in the 1000 genome germline sequence database or in the dbSNP132 database of naturally occurring germline polymorphisms. Integration of all the genes obtained from genomic feature analyses (differential expression, alternative splicing, single nucleotide variance) has been carried out to indentify biological processes that are specific to the HER2+ tumor subtype. Key nodes and pathways that are specific to HER2+ tumors will be evaluated for association with clinical outcome in a large series of patients who have received HER2-targeted therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4926. doi:1538-7445.AM2012-4926