Lee, Yong Yi

Assessment of bone density is an important part of liver transplantation (LT) evaluation for early identification and treatment of osteoporosis. Dual‐energy X‐ray absorptiometry (DXA) is currently the standard clinical test for osteoporosis; however, it may contribute to the appointment burden on LT candidates during the cumbersome evaluation process, and there are limitations affecting its accuracy. In this study, we evaluate the utility of biomechanical analysis of vertebral images obtained during dual‐energy abdominal triple‐phase computed tomography (TPCT) in diagnosing osteoporosis among LT candidates. We retrospectively reviewed cases evaluated for LT between January 2017 and March 2018. All patients who underwent TPCT within 3 months of DXA were included. The biomechanical computed tomography (BCT) analysis was performed at a centralized laboratory (O.N. Diagnostics, Berkeley, CA) by 2 trained analysts blinded to the DXA data. DXA‐based osteoporosis was defined as a T score ≤−2.5 at the hip or spine. BCT‐based osteoporosis was defined as vertebral strength ≤4500 N for women or ≤6500 N for men or trabecular volumetric bone mineral density ≤80 mg/cm3. Comparative data were available for 91 patients who had complete data for both DXA and BCT: 31 women and 60 men, age 54 ± 11 years (mean ± standard deviation), mean body mass index 28 ± 6 kg/m2. Using DXA as the clinical reference, sensitivity of BCT to detect DXA‐defined osteoporosis was 83.3% (20/24 patients) and negative predictive value was 91.7%; specificity and positive predictive value were 65.7% and 46.5%, respectively. BCT analysis of vertebral images on triple‐phase computed tomography, routinely obtained during transplant evaluation, can reliably rule out osteoporosis in LT candidates. Patients with suspicion of osteoporosis on TPCT may need further evaluation by DXA.

Abstract MUC1 is overexpressed and aberrantly glycosylated in more than 60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In this study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared with both KC and KCM. Cell lines derived from KCKO tumors have significantly less tumorigenic capacity compared with cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared with mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor, platelet-derived growth factor, or matrix metalloproteinase 9. Further, significantly less KCKO cells entered the G2–M phase of the cell cycle compared with the KCM cells. Proteomics and Western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of mitogen-activated protein kinase (MAPK), as well as a significant decrease in nestin and tubulin-α2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. Cancer Res; 71(13); 4432–42. ©2011 AACR.