Citations

Abstract Inflammation plays a role in the progression to cancer and it is linked to the presence of senescent cells. Ulcerative colitis (UC) is a chronic inflammatory disease that predisposes to colorectal cancer. Tumorigenesis in this setting is associated with telomere shortening that can be observed in the nondysplastic epithelium of UC patients with high-grade dysplasia (HGD) or cancer (UC progressors). We hypothesized that a preneoplastic field of inflammation, telomere shortening, and senescence underlies tumor progression in UC progressors. Multiple biopsies of varying histologic grade were collected along the colon of nine UC progressors and analyzed for telomere length, DNA damage, senescence, p53, p16, and chronic and acute inflammation. Twenty biopsies from four UC nonprogressors and twenty-one biopsies from control individuals without UC were also analyzed. Short telomeres and increased DNA damage, senescence, and infiltrating leukocytes were observed in biopsies located less than 10 cm from HGD or cancer. Low-grade dysplasia (LGD) had the shortest telomeres along with the highest levels of senescence and infiltrating leukocytes, whereas HGD biopsies showed the opposite pattern. The expression of p16 and p53 was low in nondysplastic biopsies but progressively increased in LGD and HGD. In addition, high levels of infiltrating leukocytes were associated with telomere shortening, senescence, and reduced p53 expression. These results suggest that dysplasia arises in a preneoplastic field of chronic inflammation, which leads to telomere shortening, DNA damage, and senescence. Our findings argue that senescence acts as a tumor suppressor mechanism that is abrogated during the transition from LGD to HGD in UC. Cancer Res; 71(5); 1669–79. ©2011 AACR.

Abstract Growth factor and K-ras-induced generation of reactive oxygen species have important roles in mediating pancreatic ductal adenocarcinoma. Pancreatic cancer cells also express high levels of active transcription factor Nuclear Factor-κB (NF-κB), which is responsible for cell survival and resistance to chemotherapeutics. The serine/threonine kinase Protein Kinase D1 (PKD1) is a sensor for oxidative stress and protects cancer cells by inducing anti-apoptotic and anti-oxidant genes. Here we provide evidence that PKD1 is the means of how high NF-κB activity levels are achieved in pancreatic cancer cells. We also show the contribution of K-ras, which is upregulated in its activity in over 90% of PDAC (pancreatic ductal adenocarcinoma). We found that K-ras in pancreatic ductal HPDE cells increases PKD1 activity and that the depletion of the pancreatic ductal adenocarcinoma cell line Panc-1 from K-ras leads to decreased PKD1 activity and NF-κB activation. As a mechanism we found that K-ras mediates activation of PKD1 via Src and that these signaling events relay to high NF-κB levels. Our data reveal K-ras as an activator of PKD1 and show that both oncogenes, Src and K-ras cooperate to activate NF-κB in PDAC through PKD1. This suggests the K-ras/Src/PKD1/NF-κB pathway as a new potential drug target for pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3143.

Abstract Epidemiologic studies suggest that breast cancer risk factor associations vary by tumor marker expression; however, individual studies have had limited power to address this question. We pooled data from up to 35,568 invasive breast cancer cases from 34 studies participating in the Breast Cancer Association Consortium (BCAC) to evaluate associations between established risk factors (age at menarche, nulliparity, age at first full time birth [AFFTB], body mass index [BMI] and family history) and breast cancer subtypes, defined by immunohistochemical expression of ER, PR, HER2, and basal markers (CK5/6 or CK5, EGFR). We used polychotomous logistic regression to evaluate relationships between risk factors and tumor subtypes in case-only analyses and to estimate case-control odds ratios and 95% confidence intervals for the associations between risk factors and specific tumor subtypes in 11 population-based studies including up to 12,841 cases and 17,032 controls. In case-only analyses, we found that reproductive risk factors were more common in hormone receptor positive tumors: early age at menarche was most strongly related to PR status (34.6% vs. 32.4% of women with age at menarche ≤12 years among PR+ and PR- cases, respectively, P= 0.001); whereas nulliparity, and late AFFTB in parous women were most strongly related to ER status (15.3% vs. 13.6% nulliparous women, 17.1% vs. 15.2% women with late AFFTB [≥30 years], among ER+ and ER- cases, respectively, P=2.6×10−6 for nulliparity and P=2.0×10−7 for late AFFTB). Nulliparity and late AFFTB were less common among triple negative (TN) tumors overall and among TN tumors expressing basal markers. Elevated BMI in women aged 50 years or younger was more common in ER-&PR- than ER+&PR+ tumors (17.0% vs 13.6% women with BMI ≥30, respectively, P=1.3×10−7), whereas above age 50 years, elevated BMI was more common in ER+&PR+ than ER+&PR- tumors (20.9% vs 16.7% women with BMI ≥30, respectively, P=2.8×10−8 comparing BMI ≥30 to BMI <25). In case-control analyses, early age at menarche was associated with increased risk of PR+ tumors; nulliparity and late AFFTB were most strongly associated with increased risk of (ER+ or PR+)&HER2- tumors, and did not increase the risk of TN tumors. Having a family history of breast cancer increased the risk of all tumor subtypes, although the association was strongest for TN tumors expressing basal markers. Our data provide convincing evidence for etiological heterogeneity with respect to breast cancer risk factors stratified by ER and PR status. Stratification by additional markers provides additional insights about etiologic differences in breast cancer risk. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 870.

Abstract Subclinical variation in immune response may be a risk factor for non-Hodgkin lymphoma (NHL). Endotoxin is a substance located in the cell wall of gram-negative bacteria that elicits a strong innate and inflammatory immune response. It is present in large amounts in animal and human fecal material, other organic material, and cigarette smoke. We hypothesized that higher endotoxin exposure might be a risk factor for NHL because of its effect on B-cell activation. Using a population based, multi-center (Detroit, Iowa, Los Angeles and Seattle) case-control study, we evaluated the association between endotoxin levels in carpet dust and NHL risk. During an in-person interview, we collected used vacuum cleaner bags from participants who had used their vacuum within the past year and had owned at least half of their carpets or rugs for 5 years or more. Dust samples were analyzed using the kinetic chromogenic Limulus amebocyte lysate assay in the Pulmonary Toxicology Facility, University of Iowa. Endotoxin measurements from 629 cases and 467 controls were log-transformed and evaluated as both continuous and categorical variables. In order to examine a possible threshold effect, endotoxin levels among controls were categorized into tertiles, with the highest tertile further split into two equal groups based on a preliminary model search. Multivariable logistic regression was used to estimate the effect of endotoxin on NHL risk adjusted for sex, age, race, education, study center, and last change of vacuum bag. The highest category of household endotoxin level in dust was associated with a 35% significantly decreased risk of NHL relative to the lowest category (95% confidence interval [CI] = 0.44, 0.96). The effect was stronger for the diffuse large B-cell lymphoma (DLBCL) subtype (Odds Ratio [OR]= 0.49; 95% CI= 0.26,0.91). In conclusion, contrary to our initial hypothesis, our results suggest an inverse association between high levels of household endotoxin and NHL risk. Further studies are needed to validate this finding, ideally with endotoxin measurements prior to diagnosis. Possible mechanisms of action will be discussed. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5736.

Abstract Purpose: This study uses spatially accurate image-guided tissue analysis to evaluate the correlation between Perfusion MRI (pMRI) and tissue microvascular density parameters as markers for tumor recurrence and treatment response in high-grade glioma (HGG). Methods: Following Institutional Review Board approval, we recruited previously treated (including chemo-radiation therapy) HGG patients undergoing surgical re-resection of new enhancing lesions on surveillance MRI. Preoperatively, we acquired pMRI and contrast-enhanced stereotactic T1-Weighted (T1W) MRI data sets. Intraoperatively, we recorded stereotactic locations of multiple biopsies based on T1W data sets that guided surgery. Following surgery, we coregistered pMRI and T1W data sets to calculate localized relative cerebral blood volume (rCBV) for each stereotactic specimen location. For each specimen, we performed 1) standard H&E staining to diagnose tumor recurrence or post-treatment radiation effect (PTRE); and 2) immunohistochemical analysis with CD34 to highlight tissue vessels. We analyzed CD-34 stained slides with Axiovision Automeasure 3.4 (Zeiss, Germany) to calculate both total microvessel number (MVN) and total microvessel area (MVA), each normalized to total slide specimen area (μm2). We calculated Pearson correlations to establish relationships between a) rCBV and MVN; and b) rCBV and MVA. We also performed t-test to compare MVN, MVA, and rCBV values between tumor and PTRE samples. A neuroradiologist performed all coregistration and pMRI calculations, and a neuropathologist analyzed all tissue specimens, without knowledge of corresponding data. A biostatistician performed all statistical comparisons. Results: In this preliminary study, we included 16 tissue specimens (from 8 subjects), each diagnosed as either tumor (n=7) or PTRE (n=9). We successfully calculated localized rCBV and determined both MVA and MVN for each specimen. The rCBV values showed highest correlation with total vessel area (MVA) (r=0.65, p=0.007) and slightly less correlation with vessel number (MVN) (r=0.52, p=0.04). Tumor showed significantly higher values than PTRE for all parameters: rCBV (1.87 + 0.82 versus 0.78 + 0.2, p=.002); MVA (0.22 + 0.03 versus 0.04 + 0.007, p=0.0001); and MVN (0.0068 + 0.001 versus. 0.0016 + 0.0006, p=0.0004). Conclusion: These preliminary results show the promise of Perfusion MRI to non-invasively estimate tissue microvessel density and distinguish tumor recurrence from treatment effects. The current study is ongoing to confirm results in a larger patient population. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3748.

AbstractPurposeThe purpose of this study is to determine the effect of bioabsorbable interference screw (BIS) tibial fixation with the Delta screw (antegrade) and RetroScrew (retrograde) on initial (time zero) intra‐articular graft tension in soft tissue anterior cruciate ligament (ACL) reconstruction in a cadaveric model.MethodsTen matched pairs of cadaveric tibias received one of two tibial fixation constructs using quadrupled hamstring grafts, Delta screw (antegrade) or the RetroScrew (retrograde). Each specimen was mounted to the materials testing device with the displacement force vector in line with the tibial tunnel. The construct was pre‐tensioned (10–30 N, 0.1 Hz, 10 cycles), a baseline tension of 25 N was introduced, and the change in intra‐articular graft tension before and after screw insertion was recorded.ResultsSegmental (proximal, middle, distal) BMD was utilized to assess BMD using quantitative computed tomography (qCT). The Delta screw had a higher maximum insertion torque (P = 0.03) and exhibited a larger increase in intra‐articular graft tension as compared to the RetroScrew (38.3 ± 17.9 N, 7.6 N ± 14.4, P = 0.004), respectively. There were no significant correlations between intra‐articular graft tension increase to maximum insertion torque (P = NS) or corresponding segmental BMD (P = NS).ConclusionsDelta screw tibial fixation (antegrade) in soft tissue ACL reconstruction significantly increases the initial intra‐articular graft tension as compared to RetroScrew screw fixation (retrograde) in this cadaveric model. Delta screw (antegrade) tibial fixation may increase initial quadrupled hamstring graft intra‐articular tension with currently accepted insertion techniques.

Purpose Findings from the human epidermal growth factor receptor 2 (HER2) –positive National Surgical Adjuvant Breast and Bowel Project (NSABP) B31 trial suggested that MYC/HER2 coamplification (> 5.0 copies/nucleus) was associated with additional benefit from adjuvant trastuzumab in patients with early-stage breast cancer. To further explore this relationship, we investigated associations between MYC amplification and disease-free survival (DFS) in a similar adjuvant trastuzumab HER2-positive breast cancer trial—North Central Cancer Treatment Group (NCCTG) N9831. Patients and Methods This analysis included 799 patients randomly assigned to receive chemotherapy alone or with concurrent trastuzumab on N9831. Fluorescence in situ hybridization (FISH) was performed by using a dual-probe mixture for MYC and centromere 8 (MYC:CEP8) on tissue microarrays. MYC amplification was prespecified as MYC:CEP8 ratio > 2.2 or average MYC copies/nucleus > 5.0. Exploratory variables included polysomy 8. Results In comparing DFS (median follow-up, 4.0 years) between treatments, patients with MYC:CEP8 ratio ≤ 2.2 (n = 618; 77%) and > 2.2 (n = 181; 23%) had hazard ratios (HRs) of 0.46 (P < .001) and 0.67 (P = .33), respectively (interaction P = .38). Patients with MYC copies/nucleus ≤ 5.0 (n = 534; 67%) and > 5.0 (n = 265; 33%) had HRs of 0.52 (P = .002) and 0.48 (P = .02), respectively (interaction P = .94). Patients with MYC:CEP8 ratio < 1.3 with normal chromosome 8 copy number (n = 141; 18%) and ≥ 1.3 or < 1.3 with polysomy 8 (n = 658; 82%) had HRs of 0.66 (P = .28) and 0.44 (P < .001), respectively (interaction P = .23). Patients with MYC copies/nucleus < 2.5 (n = 130; 16%) and ≥ 2.5 (n = 669; 84%) had HRs of 1.07 (P = .87) and 0.42 (P < .001), respectively (interaction P = .05). Conclusion We did not confirm the B31 association between MYC amplification and additional trastuzumab benefit. Exploratory analyses revealed potential associations between alternative MYC/chromosome 8 copy number alterations and differential benefit of adjuvant trastuzumab.

ABSTRACTBackground:The relations between hepatic steatosis and histological features of hepatocyte injury in children with nonalcoholic fatty liver disease have yet to be examined. The aims of the present study were to establish associations between steatosis amount, type, and distribution in a well‐characterized group of children with biopsy‐proven nonalcoholic fatty liver disease (NAFLD).Patients and Methods:One hundred eight children with NAFLD seen in 5 centers were studied. Clinical and laboratory data were collected. Hematoxylin‐eosin and Masson trichrome stains were evaluated by 2 expert liver pathologists. Steatosis grade (0–3), type (macrovesicular, microvesicular, or mixed), and zone (1, 3, azonal, or panacinar) were determined. The NAFLD activity score and fibrosis stage were determined.Results:Median patient age was 12 years and median body mass index was 31 kg/m2. Fibrosis was present in 87%. The median NAFLD activity score was 4. Mild, moderate, and severe steatosis were present in 42%, 34%, and 24% of biopsies, respectively. Macrovesicular steatosis was present in 81% and mixed steatosis was present in 19%. Panacinar distribution of steatosis was most frequent (40%), followed by azonal (27%). Steatosis grade positively correlated with portal inflammation (P = 0.018). Azonal distribution positively correlated with presence of hepatocyte ballooning (P = 0.03). Biopsies with mixed steatosis were approximately 20 times more likely to have megamitochondria than those with macrovesicular steatosis alone (95% confidence interval 2.3–204.9). There was no relation between steatosis amount, type, or distribution to fibrosis stage.Conclusions:Specific histological patterns of steatosis in children are associated with histological markers of steatohepatitis. Ballooning and portal inflammation correlated well with features of steatosis.

Object Supratentorial cortical ependymomas (CE) are rare, with 7 cases reported. The lesions, typically occurring in the superficial cortex in young adults and associated with a history of seizures, are not fully characterized. Furthermore, their relationship with the recently described angiocentric glioma (AG) is still being debated. This study was undertaken to summarize the authors' experience with CEs. Methods Between 1997 and 2009, 202 cases of ependymoma were surgically treated at the Mayo Clinic, 49 of which were supratentorial. Among these, 9 CE cases were retrospectively identified. Clinical, imaging, and pathological features of each case were reviewed. Results Tumors arose from the frontal (5 cases), parietal (3), and occipital (1) lobes. No tumor occurred in the temporal lobe, despite its reported association with seizures. The mean age at presentation was 27 ± 19 years (± SD) and age at resection was 36 ± 16 years. The mean size of the lesion was 16 ± 14 cm3. Seizures were the presenting symptom in 78%. Cross-sectional imaging in 8 cases was characterized by a heterogeneous mass with multiple cystlike areas and enhancement of the soft-tissue component. Gross-total resection was achieved in 8 of 9 tumors. Pathologically, 6 were low-grade (WHO Grade II) and 3 were anaplastic (WHO Grade III) ependymomas. All tumors exhibited the focal presence of perivascular pseudorosettes, but only 1 (11%) exhibited the focal presence of a true rosette. A bipolar spindle cell component resembling AG was present in 3 (33%) and “Schwannian-like” nodules in 2 (22%). Subpial aggregation and peripheral infiltration were present in 4 cases (44%). With a mean postsurgery follow-up of 62 ± 38 months, only 2 lesions recurred locally after imaging-confirmed gross-total resection, both being Grade III. In 5 (71%) of 7 patients presenting with seizures an Engel Class I outcome was achieved. Conclusions Cortical ependymomas represent a rare type of ependymoma occurring superficially in the cortex. Morphologically, these tumors are protean, varying from classic to epithelioid, clear cell, and tanycytic. Some also exhibited features typical of AG. Most tumors were low grade and cured with resection. Anaplastic tumors occur and may recur locally despite provision of radiation therapy. Cortical ependymomas frequently, but not always, present with seizures, but despite their high association with epilepsy, none occurred in the temporal lobe in any of the authors' 9 patients. Overall, CEs appear to have a relatively favorable prognosis compared with other supratentorial ependymomas.

Abstract It is now widely accepted that a spectrum of somatic alterations occur in human cancer and that particular alterations are associated with response or lack of response to anti-cancer therapies. Here, we undertook a systematic correlation analysis of somatic mutations, copy number aberrations and drug response across 300+ human cancer cell lines. We studied the RAF and VEGFR inhibitor, sorafenib, evaluating associations between sorafenib response and somatic mutations in 35 common cancer genes and high-level amplifications and homozygous deletions in more than 100 minimal common regions of gain and loss, which include many known oncogenes and tumor suppressor genes. Notably, we found that NRAS mutations, among other alterations, were significantly associated with sensitivity to sorafenib (odds ratio = 7, p-value = 0.003), whereas activating BRAF mutations were strongly associated with a lack of response (odds ratio = 4.9, p-value = 0.012). Specifically, 64% (7 of 11) of NRAS mutant cell lines were sensitive to sorafenib, while only 20% (34 of 170) of NRAS wild-type lines were sensitive. On the contrary, just 6.7% (2 of 30) of BRAF mutant lines were sensitive to sorafenib. Because NRAS mutations occur frequently in leukemia and no leukemia cell lines were included in the original analysis, we selected 5 NRAS mutant and 5 NRAS wild-type leukemia cell lines for further evaluation. Consistent with our previous observation, the four most sensitive leukemia cell lines were all NRAS mutant, each line exhibiting greater than 50% growth inhibition after 72 hours of exposure to 4μM sorafenib. These results confirm the original association and suggest that across both solid tumors and hematologic malignancies, NRAS mutations may identify a subset of cancers that are likely to respond sorafenib. In addition, this work demonstrates that systematic analysis of somatic alterations and drug response across a large collection of cancer cell lines is capable of discovering novel predictive biomarkers. Citation Information: Clin Cancer Res 2010;16(7 Suppl):A41