Citations

Abstract Background/purpose: Despite recent advances in the development of androgen deprivation therapies (ADT), prostate cancer (PCa) remains the second leading cause of cancer death in American men. Thus, there is a critical need to improve treatment outcomes for men with aggressive PCa. The purpose of this study was to identify and functionally characterize kinases that can serve as both prognostic biomarkers and therapeutic targets in PCa. Methods: To identify kinases associated with metastatic progression of PCa, we utilized high-density oligonucleotide arrays to interrogate the expression of all kinases in 545 prostatectomy samples, obtained from high-risk patients with long-term clinical follow-up (>10 years). We ranked all kinases by their fold change in expression between PCas that subsequently metastasized versus those that did not. We then characterized the top ranked kinase in preclinical PCa models with in vitro mechanistic experiments and in vivo therapeutic studies. Results: We nominated DNA-dependent protein kinase (DNAPK) as the top kinase associated with metastatic PCa progression. Interrogation of pathways associated with DNAPK knockdown in PC3, DU145, VCaP and C4-2B, identified canonical Wnt signaling as the top DNAPK-activated pathway. In PCa cells (PC3, LNCaP C.S. {LNCaP grown under charcoal-stripped serum condition}, C4-2B and LNCaP-AR) DNAPK inhibition significantly abrogates Wnt signaling and abolishes cell proliferation, migration and invasion. Interestingly, we found that DNAPK directly modulates the Wnt signaling independent of the androgen receptor (AR), highlighting the therapeutic potential of DNAPK inhibition in cancers resistant to ADT. Indeed, in VCaP xenograft models, pharmacologic inhibition of DNAPK with NU7441 demonstrated 3.4 fold (p<0.01) reduction of tumor growth at non-toxic doses. Using an independent prostate cancer tissue cohort, we validate DNAPK expression as a biomarker for metastatic disease progression (p = 6.4 e−06, hazard ratio = 2). Conclusion: In summary, we nominate DNAPK as a potential biomarker of disease progression and as a novel therapeutic target in aggressive prostate cancer. Our data suggests that DNAPK mediates PCa progression by upregulating Wnt signaling, and demonstrates that DNAPK inhibition results in significant tumor responses in PCa xenografts. Citation Format: Vishal Kothari, Jonathan F. Goodwin, Shuang Zhao, Elai Davicioni, Jeffrey R. Karnes, Robert B. Den, Rohit Mehra, Karen E. Knudsen, Felix Y. Feng. Investigating DNAPK as a biomarker and a novel therapeutic target in aggressive prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2853. doi:10.1158/1538-7445.AM2015-2853

Abstract Emerging evidence demonstrates that the DNA repair kinase DNA-PK exerts divergent roles in transcriptional regulation of unsolved consequence. Here, in vitro and in vivo interrogation demonstrate that DNA-PK functions as a selective modulator of transcriptional networks that induce cell migration, invasion, and metastasis. Accordingly, suppression of DNA-PK inhibits tumor metastases. Clinical assessment revealed that DNA-PK is significantly elevated in advanced disease, and independently predicts for metastases, recurrence, and reduced overall survival. Further investigation demonstrated that DNA-PK in advanced tumors is highly activated, independently of DNA damage indicators. Combined, these findings put forth new paradigms for DNA-PK function, identify DNA-PK as a potent driver of tumor progression and metastases, and nominate DNA-PK as a therapeutic target for advanced malignancies. Citation Format: Jonathan F. Goodwin, Vishal Kothari, Justin M. Drake, Shuang Zhao, Emanuela Dylgjeri, Jeffry L. Dean, Matthew J. Schiewer, Christopher McNair, Michael S. Magee, Robert B. Den, Ziqi Zhu, Nicholas A. Graham, Ajay A. Vashisht, James A. Wohlschlegel, Thomas G. Graeber, R Jeffrey Karnes, Mandeep Takhar, Elai Davicioni, Scott A. Tomlins, Nima Sharifi, Owen N. Witte, Felix Y. Feng, Karen E. Knudsen. DNA-PK-mediated transcriptional regulation drives tumor progression and metastasis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1860. doi:10.1158/1538-7445.AM2015-1860

Abstract BACKGROUND The Kidney Disease Improving Global Outcomes (KDIGO) guideline recommends use of a cystatin C–based estimated glomerular filtration rate (eGFR) to confirm creatinine-based eGFR between 45 and 59 mL · min−1 · (1.73 m2)−1. Prior studies have demonstrated that comorbidities such as solid-organ transplant strongly influence the relationship between measured GFR, creatinine, and cystatin C. Our objective was to evaluate the performance of cystatin C–based eGFR equations compared with creatinine-based eGFR and measured GFR across different clinical presentations. METHODS We compared the performance of the CKD-EPI 2009 creatinine-based estimated GFR equation (eGFRCr) and the newer CKD-EPI 2012 cystatin C–based equations (eGFRCys and eGFRCr-Cys) with measured GFR (iothalamate renal clearance) across defined patient populations. Patients (n = 1652) were categorized as transplant recipients (n = 568 kidney; n = 319 other organ), known chronic kidney disease (CKD) patients (n = 618), or potential kidney donors (n = 147). RESULTS eGFRCr-Cys showed the most consistent performance across different clinical populations. Among potential kidney donors without CKD [stage 2 or higher; eGFR >60 mL · min−1 · (1.73 m2)−1], eGFRCys and eGFRCr-Cys demonstrated significantly less bias than eGFRCr; however, all 3 equations substantially underestimated GFR when eGFR was <60 mL · min−1 · (1.73 m2)−1. Among transplant recipients with CKD stage 3B or greater [eGFR <45 mL · min−1 · (1.73 m2)−1], eGFRCys was significantly more biased than eGFRCr. No clear differences in eGFR bias between equations were observed among known CKD patients regardless of eGFR range or in any patient group with a GFR between 45 and 59 mL · min−1 · (1.73 m2)−1. CONCLUSIONS The performance of eGFR equations depends on patient characteristics that are readily apparent on presentation. Among the 3 CKD-EPI equations, eGFRCr-Cys performed most consistently across the studied patient populations.

Abstract Background & Aims Accumulating evidence indicates that micro RNA s play a role in a number of disease processes including the pathogenesis of liver fibrosis in hepatitis C infection. Our goal is to add to the accruing information regarding micro RNA deregulation in liver fibrosis to increase our understanding of the underlying mechanisms of pathology and progression. Methods We used next generation sequencing to profile all detectable micro RNA s in liver tissue and serum from patients with hepatitis C, stages F1–F4 of fibrosis. Results We found altered expression of several micro RNA s, in particular, miR‐182, miR199a‐5p, miR‐200a‐5p and miR‐183 were found to be significantly upregulated in tissue from liver biopsies of hepatitis C patients with advanced fibrosis, stage F3 and F4, when compared with liver biopsies from patients with early fibrosis, stages F1 and F2. We also found miR‐148‐5p, miR‐1260b, miR‐122‐3p and miR‐378i among the micro RNA s most significantly down‐regulated from early to advanced fibrosis of the liver. We also sequenced the serum micro RNA s; however, we were not able to detect significant changes in circulating micro RNA s associated with fibrosis stage after adjusting for multiple tests. Conclusions Adding measurements of tissue micro RNA s acquired during routine biopsies will continue to increase our knowledge of underlying mechanisms of fibrosis. Our goal is that these data, in combination with studies from other researchers and future long‐term studies, could be used to enhance the staging accuracy of liver biopsies and expand the surveillance of patients at increased risk for cancer and progression to advanced fibrosis.

ObjectiveWe aim to create a model of mandibular osteoradionecrosis in athymic rats. Athymic rats provide an immunosuppressed environment whereby human stem cells and biomaterials can be used to investigate regenerative solutions for osteoradionecrosis, bridging the gap between in vivo testing and clinical application.Study DesignProspective animal study.SettingAcademic otolaryngology department laboratory.Subjects and MethodsAfter Institutional Animal Care and Use Committee approval, 10 athymic nude rats were divided into 2 groups. The experimental group (n = 6) underwent irradiation (20 Gy), while the control group (n = 4) underwent sham irradiation catheter placement only. All 10 rats underwent extraction of the second mandibular molar 7 days later. The rats were sacrificed 28 days after dental extraction, and their mandibles were harvested. The mandibles were examined with histologic analysis and bone volume analysis based on 3‐dimensional micro–computed tomography.ResultsAll 10 rats survived the experiment period. Radiographic and histologic analysis revealed decreased bone formation in the experimental group compared with the control group. Jaw region volume ratio was 0.83 for the experimental group versus 0.97 in the control group (P =. 003). The region‐of‐interest volume ratio was 0.75 in the experimental group and 0.97 in the control group (P =. 005). Histologically, there were increased osteoclasts (P =. 02) and decreased osteoblasts (P =. 001) as well as increased fibrosis in the experimental group versus the control group.ConclusionMandibular osteoradionecrosis can be effectively and reproducibly produced in an athymic rat model. This will allow further research to study regenerative medicine in an athymic rat model.

A woman in her late 50s experienced a witnessed, sudden out of hospital cardiac arrest. Initial workup included coronary angiography, transthoracic echocardiogram and a CT scan of the chest to rule out pulmonary embolus. She was subsequently discharged home without an implantable cardioverter defibrillator (ICD) or a life vest. On follow-up at another facility, an ICD was placed and a Holter monitor showed no ventricular ectopy. Further transthoracic echocardiographic images were obtained, which were suggestive of apical hypertrophic cardiomyopathy. A limited transthoracic echocardiogram with contrast was performed, which did not elucidate the hypertrophy. However, eccentric left ventricular apical wall hypertrophy was visualised by a coronary CT scan.

ObjectiveTo characterize disease presentation and outcomes following surgical treatment of parotid malignancies with occult temporal bone facial nerve (FN) involvement.Study DesignCase series with chart review.SettingTertiary academic referral center.Subjects and MethodsThirty consecutive patients (mean age 58 years; 77% men) who underwent surgery for parotid malignancies with occult perineural involvement of the intratemporal FN were included. Primary outcome measures included margin status and recurrence.ResultsThe mean duration of clinical follow‐up was 49 months, and the most common presenting symptom was FN paresis (n = 23; 77%) followed by pain (n = 15; 50%). To obtain a proximal FN margin, 27 patients (90%) underwent mastoidectomy, and 3 patients (10%) had lateral temporal bone resection. The intratemporal FN margin was cleared in 26 patients (87%), most commonly in the mastoid segment (60%). Adjuvant therapy was given in 25 patients (83%). Ten patients (33%) experienced locoregional (4; 13%) and/or distant (8; 27%) recurrence at a median of 19 months (mean 26, 2–54 months) following surgery. Locoregional failure was significantly more common in cases with a positive intratemporal FN margin (66% vs 8%; P =. 045). Overall 1‐, 3‐, and 5‐year disease‐specific survival rates were 83%, 79%, and 72%, respectively.ConclusionsPerineural invasion of the intratemporal FN by parotid malignancy is uncommon. Normal preoperative FN function does not preclude histopathologic involvement. Temporal bone FN exploration should be considered when a positive margin is encountered at the stylomastoid foramen, as failure to do so is associated with an increased rate of locoregional recurrence.

ObjectiveTo characterize the evolving management of vestibular schwannoma (VS) in the United States.Study DesignRetrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database.SettingSEER database.Subjects and MethodsAll patients with a diagnosis of VS were analyzed. Data were described and compared using trend analyses and univariate and multivariable logistic regression.ResultsA total of 8330 patients (average age 54.7 years, 51.9% female) were analyzed. The mean incidence was approximately 1.1 per 100,000 per year and did not vary significantly across time; however, from 2004 to 2011, there was a statistically significant decrease in tumor size category at time of diagnosis (P <. 01). Overall, 3982 patients (48%) received primary microsurgery, 1978 (24%) radiation therapy alone, and 2370 (29%) observation. Within the microsurgical cohort, 732 (18%) underwent subtotal resection, and of those, 98 (13.4%) received postoperative radiation therapy. Multivariable regression revealed that surgical treatment was more common in younger patients and larger tumor size categories (P <. 05). Management trend analysis revealed that microsurgery was used less frequently over time (P <. 0001), observation was used more frequently (P <. 0001), and the pattern of radiation therapy remained unchanged. Linear regression was used to create an equation that was applied to predict future management practices. These data predict that by 2026, half of all cases of VS will be managed initially with observation.ConclusionWhile the incidence of VS has remained steady, tumor size at time of diagnosis has decreased over time. Within the United States there has been a clear, recent evolution in management toward observation.