Faculty Bibliography

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease affecting 30% of the population in the United States. Biopsy is the gold standard for diagnosing NAFLD. Liver histology assesses the amount of fat, and determines type and extent of cell injury, inflammation and fibrosis. However, liver biopsy is invasive and is limited by sampling error. Current radiological diagnostic modalities can evaluate the 'physical' morphology in liver by quantifying the backscattered US signals, but cannot interrogate the 'histochemical' components forming these backscatterers. For example, ultrasound (US) imaging can detect the presence of fat but cannot differentiate steatosis alone from steatohepatitis. Our previous study of photoacoustic physiochemical analysis (PAPCA) has demonstrated that this method can characterize the histological changes in livers during the progression of NAFLD in animal models. In this study, we will further validate PAPCA with human livers. Ex vivo human liver samples with steatosis, fibrosis and cirrhosis will be scanned using optical illumination at wavelengths of 680-1700 nm and compared to histology results. In vivo study on human subjects with confirmed steatosis is planned using our PA-ultrasound (US) parallel imaging system based on Verasonic US imaging flatform with an L7-4 probe. 10 mJ/cm(2) per pulse optical energy at 755 nm will be delivered to the skin surface, which is under the safety limit of American National Standard Institute. Preliminary study with ex vivo human tissue has demonstrated the potential of the proposed approach in differentiating human liver conditions.

Pancreatic ductal adenocarcinoma (PDA) is characterized by a dense stroma consisting of a prevalence of activated fibroblasts whose functional contributions to pancreatic tumorigenesis remain incompletely understood. In this study, we provide the first identification and characterization of mesenchymal stem cells (MSC) within the human PDA microenvironment, highlighting the heterogeneity of the fibroblast population. Primary patient PDA samples and low-passage human pancreatic cancer-associated fibroblast cultures were found to contain a unique population of cancer-associated MSCs (CA-MSC). CA-MSCs markedly enhanced the growth, invasion, and metastatic potential of PDA cancer cells. CA-MSCs secreted the cytokine GM-CSF that was required for tumor cell proliferation, invasion, and transendothelial migration. Depletion of GM-CSF in CA-MSCs inhibited the ability of these cells to promote tumor cell growth and metastasis. Together, these data identify a population of MSCs within the tumor microenvironment that possesses a unique ability, through GM-CSF signaling, to promote PDA survival and metastasis. SIGNIFICANCE: The role of stroma in pancreatic cancer is controversial. Here, we provide the first characterization of MSCs within the human PDA microenvironment and demonstrate that CA-MSCs promote tumorigenesis through the production of GM-CSF. These data identify a novel cytokine pathway that mediates mesenchymal-epithelial cross-talk and is amenable to therapeutic intervention. Cancer Discov; 6(8); 886-99. (c)2016 AACR.This article is highlighted in the In This Issue feature, p. 803.

BACKGROUND: There is no standard of care for adjuvant therapy for patients with hepatocellular carcinoma. This trial was designed to assess the efficacy and safety of sorafenib versus placebo as adjuvant therapy in patients with hepatocellular carcinoma after surgical resection or local ablation. METHODS: We undertook this phase 3, double-blind, placebo-controlled study of patients with hepatocellular carcinoma with a complete radiological response after surgical resection (n=900) or local ablation (n=214) in 202 sites (hospitals and research centres) in 28 countries. Patients were randomly assigned (1:1) to receive 400 mg oral sorafenib or placebo twice a day, for a maximum of 4 years, according to a block randomisation scheme (block size of four) using an interactive voice-response system. Patients were stratified by curative treatment, geography, Child-Pugh status, and recurrence risk. The primary outcome was recurrence-free survival assessed after database cut-off on Nov 29, 2013. We analysed efficacy in the intention-to-treat population and safety in randomly assigned patients receiving at least one study dose. The final analysis is reported. This study is registered with ClinicalTrials.gov, number NCT00692770. FINDINGS: We screened 1602 patients between Aug 15, 2008, and Nov 17, 2010, and randomly assigned 1114 patients. Of 556 patients in the sorafenib group, 553 (>99%) received the study treatment and 471 (85%) terminated treatment. Of 558 patients in the placebo group, 554 (99%) received the study treatment and 447 (80%) terminated treatment. Median duration of treatment and mean daily dose were 12.5 months (IQR 2.6-35.8) and 577 mg per day (SD 212.8) for sorafenib, compared with 22.2 months (8.1-38.8) and 778.0 mg per day (79.8) for placebo. Dose modification was reported for 497 (89%) of 559 patients in the sorafenib group and 206 (38%) of 548 patients in the placebo group. At final analysis, 464 recurrence-free survival events had occurred (270 in the placebo group and 194 in the sorafenib group). Median follow-up for recurrence-free survival was 8.5 months (IQR 2.9-19.5) in the sorafenib group and 8.4 months (2.9-19.8) in the placebo group. We noted no difference in median recurrence-free survival between the two groups (33.3 months in the sorafenib group vs 33.7 months in the placebo group; hazard ratio [HR] 0.940; 95% CI 0.780-1.134; one-sided p=0.26). The most common grade 3 or 4 adverse events were hand-foot skin reaction (154 [28%] of 559 patients in the sorafenib group vs four [<1%] of 548 patients in the placebo group) and diarrhoea (36 [6%] vs five [<1%] in the placebo group). Sorafenib-related serious adverse events included hand-foot skin reaction (ten [2%]), abnormal hepatic function (four [<1%]), and fatigue (three [<1%]). There were four (<1%) drug-related deaths in the sorafenib group and two (<1%) in the placebo group. INTERPRETATION: Our data indicate that sorafenib is not an effective intervention in the adjuvant setting for hepatocellular carcinoma following resection or ablation.

Hepatocellular carcinoma (HCC) is highly associated with inflammation. Myeloid cells, including tumor-associated macrophages and myeloid-derived suppressor cells, are abundant in the HCC microenvironment and are often associated with poor prognosis. Myeloid cells in HCC play a vital role in supporting tumor initiation, progression, angiogenesis, metastasis, and therapeutic resistance. Here, we summarize our current knowledge about myeloid cells in HCC and focus on their immune-suppressive activities and tumor-promoting functions, as well as the relevance to potential new therapies in HCC.