Abstract Background: Hepatocellular Carcinoma (HCC) is the 6th most common cancer and the 2nd leading cause of cancer-related mortality in the world. Sub-Saharan Africa and Eastern Asia are regions endemic for viral hepatitis, accounting for 80% of all HCC cases worldwide. A recent hospital-based study assessing the frequency of hepatitis B (HBV), hepatitis C (HCV), and HCC among Somali immigrants seen at Mayo Clinic determined the adjusted frequency for HBsAg positivity was 10-fold higher and anti-HCV positivity was 3-fold higher as compared to non-Somali residents of Olmsted County, Minnesota. Furthermore, HCV infection was identified as the leading contributor to HCC development among Somalis. The overall goal of this study is to determine the risk factors, surveillance, treatment options, and outcomes of Somalis with HCC seen at Mayo Clinic. Methods: The Mayo Clinic Unified Data Platform Advanced Cohort Explorer (ACE) query tool was used to identify Somali patients seen at Mayo Clinic from March 1, 1998 to March 31, 2015. Clinical notes were searched in ACE using conjunction and disjunction combinations: the terms Somali, Somalia or Somalian were linked with the terms HCC, Hepatocellular Carcinoma or Liver Cancer. Diagnosis was validated using histopathology and/or imaging reports from the electronic medical record (EMR). To confirm the ethnicity of identified patients, names were screened by author HMA who is of Somali heritage. Variables abstracted from the EMR include demographics, etiology of HCC, diagnosis date, date of death or last contact, Child-Turcotte-Pugh class, Barcelona Clinic Liver Cancer (BCLC) stage, comorbid conditions, initial and subsequent treatments, HCC surveillance, cirrhosis and other malignancies. Results: 54 Somali patients diagnosed with HCC were seen at Mayo Clinic from March 1, 1998 to March 31, 2015. The mean age was 63±16.3 and 36 (67%) individuals were male. Thirty-eight (70%) of the 54 HCC patients had HCV, 14 (26%) had HBV, 1 (2%) had non-alcoholic steatohepatitis (NASH), and 1 (2%) had unknown etiology for HCC. Of those with known HCV genotypes, the most common were genotype 4 (45%) and 3 (35%). At the time of HCC diagnosis, 16 (32%) presented with BCLC stage A, 5 (10%) with stage B, 17 (34%) with stage C, and 12 (24%) with stage D. Of the 54 patients, 43 (80%) had cirrhosis, 15 (28%) had vascular invasion, and 10 (19%) had metastatic HCC. Regarding treatment, 12 (22%) patients received curative treatment while 42 (78%) received palliative treatment. Orthotopic liver transplantation (OLT) was received by 3 (6%) of Somali patients compared to 19% of non-Somali HCC patients seen at Mayo Clinic between 2007 and 2009. HCC was detected during surveillance in 11 (20%) Somali HCC patients; of the 11, 2 (4%) received semiannual surveillance. Conclusions: These findings provide a starting point to address liver cancer disparities among Somalis. HCV genotype 4 was most commonly associated with HCC development among the study population. Due to low surveillance rates, more Somalis presented with end-stage liver disease. Furthermore, advanced stage HCC was disproportionately found among Somalis compared to the general North American population. A recent study demonstrated that 11% of North American HCC patients seen at 4 major medical centers presented with stage D. By contrast, our study found 25% of Somalis had Stage D HCC. As a result, Somalis are more likely to receive palliative rather than curative treatments. Improving the identification of individuals with chronic HBV or HCV who are at increased risk for HCC and implementing more comprehensive HCC surveillance is likely to reduce the burden of HCC among this population. Citation Format: Hawa M. Ali, Nasra H. Giama, Hager Ahmed Mohammed, Essa A. Mohamed, Ju Dong Yang, Abdirashid M. Shire, Lewis R. Roberts. Hepatocellular carcinoma characteristics and outcomes among Somali immigrants. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B64.
Functional Plasticity of Adipose-Derived Stromal Cells During Development of Obesity
Abstract Obesity is a major risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases, and cancer. Expansion of the adipose mass requires adipocyte precursor cells that originate from multipotent adipose-derived stromal cells (ASCs), which in turn also participate in repair activities. ASC function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. We tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. Domestic pigs were fed with an atherogenic (n = 7) or normal (n = 7) diet for 16 weeks. Abdominal adipose tissue biopsies were collected after 8, 12, and 16 weeks of diet for ASC isolation and immunohistochemistry of in situ ASCs and tumor necrosis factor-α (TNF-α). Longitudinal changes in proliferation, differentiation, and anti-inflammatory functions of ASCs were assessed. At 16 weeks, upregulated TNF-α expression in adipose tissue from obese pigs was accompanied by increased numbers of adipocyte progenitors (CD24+/CD34+) in adipose tissue and enlarged adipocyte size. In vitro, ASCs from obese pigs showed enhanced adipogenic and osteogenic propensity, which was abolished by anti-TNF-α treatment, whereas lean ASCs treated with TNF-α showed enhanced adipogenesis. Furthermore, obese ASCs showed increased senescence compared with lean ASCs, whereas their immunomodulatory capacity was preserved. Adipose tissue inflammation promotes an increase in resident adipocyte progenitors and upregulated TNF-α enhances ASC adipogenesis. Thus, adipose tissue anti-inflammatory strategies might be a novel target to attenuate obesity and its complications. Significance Adipose-derived stromal cell (ASC) function might decline in a disease milieu, but it remains unclear whether ASC function varies during the development of obesity. This study tested the hypothesis that microenvironmental inflammatory changes during development of metabolic disorders in obesity affect ASC function. It was found that ASCs show increased propensity for differentiation into adipocytes, which is partly mediated by upregulated tumor necrosis factor-α (TNF-α), likely in their adipose tissue microenvironment. Furthermore, TNF-α magnified obese ASC senescence, although it did not regulate their anti-inflammatory properties. Thus, adipose tissue inflammation might be a novel therapeutic target to avert ASC maldifferentiation and senescence.
Immune checkpoint therapy with PD-1 blockade has emerged as an effective therapy for many advanced cancers; however, only a small fraction of patients achieve durable responses. To date, there is no validated blood-based means of predicting the response to PD-1 blockade. We report that Bim is a downstream signaling molecule of the PD-1 pathway, and its detection in T cells is significantly associated with expression of PD-1 and effector T cell markers. High levels of Bim in circulating tumor-reactive (PD-1 + CD11a hi CD8 + ) T cells were prognostic of poor survival in patients with metastatic melanoma who did not receive anti–PD-1 therapy and were also predictive of clinical benefit in patients with metastatic melanoma who were treated with anti–PD-1 therapy. Moreover, this circulating tumor-reactive T cell population significantly decreased after successful anti–PD-1 therapy. Our study supports a crucial role of Bim in both T cell activation and apoptosis as regulated by PD-1 and PD-L1 interactions in effector CD8 + T cells. Measurement of Bim levels in circulating T cells of patients with cancer may provide a less invasive strategy to predict and monitor responses to anti–PD-1 therapy, although future prospective analyses are needed to validate its utility.
Synergy between loss of NF1 and overexpression of MYCN in neuroblastoma is mediated by the GAP-related domain
Earlier reports showed that hyperplasia of sympathoadrenal cell precursors during embryogenesis in Nf1-deficient mice is independent of Nf1’s role in down-modulating RAS-MAPK signaling. We demonstrate in zebrafish that nf1 loss leads to aberrant activation of RAS signaling in MYCN-induced neuroblastomas that arise in these precursors, and that the GTPase-activating protein (GAP)-related domain (GRD) is sufficient to suppress the acceleration of neuroblastoma in nf1-deficient fish, but not the hypertrophy of sympathoadrenal cells in nf1 mutant embryos. Thus, even though neuroblastoma is a classical “developmental tumor”, NF1 relies on a very different mechanism to suppress malignant transformation than it does to modulate normal neural crest cell growth. We also show marked synergy in tumor cell killing between MEK inhibitors (trametinib) and retinoids (isotretinoin) in primary nf1a-/- zebrafish neuroblastomas. Thus, our model system has considerable translational potential for investigating new strategies to improve the treatment of very high-risk neuroblastomas with aberrant RAS-MAPK activation.
PPP6R3‐USP6 amplification: Novel oncogenic mechanism in malignant nodular fasciitis
Saxagliptin and Tadalafil Differentially Alter Cyclic Guanosine Monophosphate (cGMP) Signaling and Left Ventricular Function in Aortic‐Banded Mini‐Swine
Background Cyclic guanosine monophosphate‐protein kinase G‐phosphodiesterase 5 signaling may be disturbed in heart failure ( HF ) with preserved ejection fraction, contributing to cardiac remodeling and dysfunction. The purpose of this study was to manipulate cyclic guanosine monophosphate signaling using the dipeptidyl‐peptidase 4 inhibitor saxagliptin and phosphodiesterase 5 inhibitor tadalafil. We hypothesized that preservation of cyclic guanosine monophosphate cGMP signaling would attenuate pathological cardiac remodeling and improve left ventricular ( LV ) function. Methods and Results We assessed LV hypertrophy and function at the organ and cellular level in aortic‐banded pigs. Concentric hypertrophy was equal in all groups, but LV collagen deposition was increased in only HF animals. Prevention of fibrotic remodeling by saxagliptin and tadalafil was correlated with neuropeptide Y plasma levels. Saxagliptin better preserved integrated LV systolic and diastolic function by maintaining normal LV chamber volumes and contractility (end‐systolic pressure‐volume relationship, preload recruitable SW ) while preventing changes to early/late diastolic longitudinal strain rate. Function was similar to the HF group in tadalafil‐treated animals including increased LV contractility, reduced chamber volume, and decreased longitudinal, circumferential, and radial mechanics. Saxagliptin and tadalafil prevented a negative cardiomyocyte shortening‐frequency relationship observed in HF animals. Saxagliptin increased phosphodiesterase 5 activity while tadalafil increased cyclic guanosine monophosphate levels; however, neither drug increased downstream PKG activity. Early mitochondrial dysfunction, evident as decreased calcium‐retention capacity and Complex II ‐dependent respiratory control, was present in both HF and tadalafil‐treated animals. Conclusions Both saxagliptin and tadalafil prevented increased LV collagen deposition in a manner related to the attenuation of increased plasma neuropeptide Y levels. Saxagliptin appears superior for treating heart failure with preserved ejection fraction, considering its comprehensive effects on integrated LV systolic and diastolic function.
Initial presentation of CNS-restricted acute lymphoblastic B cell leukaemia as peripheral polyneuropathy
We report a case of a 58-year-old woman who presented with a 1-month course of progressive lower and upper extremity weakness in addition to binocular diplopia. Diagnostic lumbar puncture revealed atypical lymphoid cells with 28% blasts. Immunophenotype was consistent with B cell acute lymphoblastic leukaemia (B-ALL). Further work up showed no systemic involvement but extensive thoracolumbar-sacral leptomeningeal disease. The patient was treated with several courses of intrathecal and systemic chemotherapy followed by craniospinal irradiation for consolidation. There was initial steady improvement in neurological symptoms and leptomeningeal disease, the latter being ascertained through radiological studies and cerebrospinal fluid examination. After 10 months of response, the patient relapsed with central nervous system (CNS) and systemic disease. B-ALL is a rare precursor lymphoid neoplasm that generally presents with systemic disease. While CNS involvement is not uncommon, isolated involvement of this compartment without systemic disease is exceedingly rare.
Dync1h1
Mutation Causes Proprioceptive Sensory Neuron Loss and Impaired Retrograde Axonal Transport of Dorsal Root Ganglion Neurons
Summary Background and Purpose Sprawling ( Swl ) is a radiation‐induced mutation which has been identified to have a nine base pair deletion in dynein heavy chain 1 (DYNC1H1: encoded by a single gene Dync1h1 ). This study is to investigate the phenotype and the underlying mechanism of the Dync1h1 mutant. Methods and Results To display the phenotype of Swl mutant mice, we examined the embryos of homozygous ( Swl/Swl ) and heterozygous ( Swl /+) mice and their postnatal dorsal root ganglion (DRG) of surviving Swl /+ mice. The Swl /+ mice could survive for a normal life span, while Swl/Swl could only survive till embryonic (E) 8.5 days. Excessive apoptosis of Swl/ + DRG neurons was revealed during E11.5–E15.5 days, and the peak rate was at E13.5 days. In vitro study of mutated DRG neurons showed impaired retrograde transport of dynein‐driven nerve growth factor (NGF). Mitochondria, another dynein‐driven cargo, demonstrated much slower retrograde transport velocity in Swl/+ neurons than in wild‐type (WT) neurons. Nevertheless, the Swl , Loa, and Cra mutations did not affect homodimerization of DYNC1H1. Conclusion The Swl/Swl mutation of Dync1h1 gene led to embryonic mal‐development and lethality, whereas the Swl/+ DRG neurons demonstrated deficient retrograde transport in dynein‐driven cargos and excessive apoptosis during mid‐ to late‐developmental stages. The underlying mechanism of the mutation may not be due to impaired homodimerization of DYNC1H1.