studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 1239A
gene, encoding alpha-1-antitrypsin (AAT) protein. AAT is a
serine proteinase inhibitor that is synthesized in the liver and
secreted into the bloodstream to protect the lungs from neutrophil
elastase. Mutations in SERPINA1, most commonly the Z-allele
(Z-AAT), cause the protein to misfold resulting in retention
of aggregated AAT protein in hepatocytes and a corresponding
decrease in circulating levels of AAT leading to Alpha-1-Antitrypsin
Deficiency (A1ATD). Aggregation of Z-AAT protein in
hepatocytes is associated with liver injury, fibrosis, cirrhosis,
and hepatocellular carcinoma, while decreased circulating levels
of AAT often presents as emphysema or chronic obstructive
pulmonary disease. Using a lipid nanoparticle (LNP) system we
developed for hepatic delivery of DsiRNAs, we demonstrate
a significant reduction of human Z-AAT protein in the bloodstream
and livers of the PiZ transgenic mouse model of hepatic
A1ATD disease. Additionally, we provide evidence that targeting
SERPINA1 with DsiRNA results in a reduction of A1ATD-related
liver disease markers in PiZ transgenic mice. To further
extend DsiRNA delivery approaches, we have also developed
DsiRNA conjugates that can effectively deliver DsiRNAs to the
liver without the need for LNP delivery systems. DsiRNA conjugates
were prepared through the addition of N-acetyl galactosamine
(GalNAc) sugars to the DsiRNA molecule to mediate
delivery to hepatocytes via the highly expressed asialoglycoprotein
receptor. SERPINA1-GalNAc conjugates delivered to
PiZ transgenic mice effectively reduced Z-AAT protein levels.
These results indicate Dicerna’s DsiRNA platform, delivered by
either LNP-mediated or GalNAc-conjugated delivery systems,
may be an effective therapeutic approach for hepatic disease.
Disclosures:
Rohan Diwanji - Employment: Dicerna Pharmceuticals; Stock Shareholder:
Dicerna Pharmceuticals
Utsav H. Saxena - Employment: Dicerna Pharmaceuticals
Hank Dudek - Employment: Dicerna
Nicole Avitahl-Curtis - Employment: Dicerna Pharmaceuticals, Inc.
Chaitali Dutta - Employment: Dicerna Pharmaceuticals
Benjamin Holmes - Employment: Dicerna Pharmaceuticals; Stock Shareholder:
Dicerna Pharmaceuticals
Marc Abrams - Employment: Dicerna Pharmaceuticals
Kevin Craig - Employment: Dicerna Pharmaceuticals, Inc
Luciano Apponi - Employment: Dicerna Pharmaceuticals
Martin Koser - Employment: Dicerna Pharmaceuticals
Chengjung Lai - Employment: Dicerna Pharmaceuticals
Bob D. Brown - Employment: Dicerna Pharmaceuticals
The following authors have nothing to disclose: Natalie W. Pursell, Wei Zhou,
Weimin Wang, Dongyu Chen, Purva Pandya, Xue Shui, Boyoung Kim, Rachel
Storr, Anee Shah, Edmond Chipumuro, Girish R. Chopda, Jr-Shiuan Yang, Marita
S. Larsson Cohen, Naim Nazef, Nandini Venkat, Shanthi Ganesh, Venkat
Krishnamurthy, Wendy Cyr, Zakir Siddiquee
2117
GNPAT Variant D519G in patients referred for HFE
Hemochormatosis Testing
Alexander Levstik 2 , Alan Stuart 2 , Paul Adams 1 ; 1 Gastroenterology,
University Hospital, London, ON, Canada; 2 Laboratory Medicine,
Western University, London, ON, Canada
Background: Previous studies in high and low expressors has
demonstrated that a variant in the GNPAT gene (D519G,
Rs11558492, chromosome 1, exon 11) has been associated
with severe iron overload in C282Y homozygotes for hemochromatosis
(McLaren C, et al, Hepatology 2015). The GNPAT
gene is associated with peroxisomal diseases and may be
involved with transferrin receptor recycling. Gene silencing of
GNPAT reduces intracellular hepcidin. In this study, a GNPAT
variant was assessed prospectively in patients over a range of
serum ferritin levels referred for HFE testing. Methods: Consecutive
patients sent for HFE testing were studied for the GNPAT
variant using a TaqMan kit assay (Life Technologies, Burlington,
ON). The assay was validated by sequencing. Serum ferritin
was compared in C282Y homozygotes with and without
the GNPAT variant. The frequency of the GNPAT variant in
referred patients was compared to a control population of voluntary
blood donors without HFE mutations. Results: There were
473 patients that had GNPAT analysis. The allele frequency for
the GNPAT variant in C282Y homozygotes (n=81) was 0.302
and in wild type control patients (n =392) was 0.213 (p = .08)
Forty-nine percent (40) of the C282Y homozygotes were heterozygous
(n=31) or homozygous (n = 9) for the GNPAT variant.
The mean ferritin ± standard deviation did not significantly
differ between C282Y homozygotes with (1450 μg/L ±1529)
and without the GNPAT variant (1464 μg/L ± 1169). Conclusions:
C282Y homozygotes referred for HFE testing commonly
have a GNPAT variant. This GNPAT variant does not appear
be a co-modifying gene affecting expression of HFE related
hemochromatosis in this population. Further functional studies
are in progress to determine the role of the GNPAT variant in
cellular iron metabolism.
GNPAT variant in patients
Disclosures:
The following authors have nothing to disclose: Alexander Levstik, Alan Stuart,
Paul Adams
2118
Vitamin D deficiency promotes hepatocellular cancer
through activation of WNT/TLR signaling with disruption
of TGF-β/Smad3
Ji-Hyun Shin 1 , Jian Chen 1 , Nina M. Muñoz 1 , Lior Katz 2 , Andrea
C. Cortes 1 , Vivek Shukla 3 , Sangbae Kim 1 , H. Franklin Herlong 1 ,
Keigo Machida 4 , Hidekazu Tsukamoto 4 , Kirti Shetty 5 , Asif Rashid 1 ,
Wilma S Jogunoori 6 , Aiwu R. He 7 , Lynt B. Johnson 7 , Ju-Seog Lee 1 ,
Jon White 6 , Lopa Mishra 1 ; 1 The University of Texas MD Anderson
Cancer Center, Houston, TX; 2 Sheba Medical Center, Tel
Hashomer, Israel; 3 NCI, Bethesda, MD; 4 University of Southern
California School of Medicine, Los Angeles, CA; 5 Johns Hopkins
University School of Medicine, Baltimore, MD; 6 Veterans Affairs
Medical Center, Washington, DC; 7 Georgetown University, Washington,
DC
Disruption of the TGF-β pathway has been associated with
liver tumorigenesis, conditions associated with low Vitamin D
(VD) levels. We examined a potential chemo-preventive role
of VD in hepatocellular cancer (HCC) in the context of TGF-β
inactivation. Methods: (1) We analyzed transcriptome profiles
of 488 HCC and screened for somatic mutations (n = 202) and
expression of the TGF-β pathway and VD pathway molecules
(n = 147) in HCC from The Cancer Genome Atlas (TCGA). (2)
Expression of TGF-β and VD pathway molecules was also evaluated
by immunohistochemistry in liver samples from patients
with hepatitis C virus (HCV)-associated cirrhosis who received
VD supplements. (3) We examined the effects of VD on HCC
development through gene and protein expression profiles in
diethylnitrosamine -treated WT, and in mutant mouse models in
the TGF-β pathway. (4) We further validated the effects of VD
and performed further functional analyses examining crosstalk
between TGF-β, VD and key members of cell proliferation and
inflammation that were altered with deprivation of VD. Results:
(1) We observed somatic mutations and a strong correlation
between VD-related genes and the TGF-β pathway in the TCGA
genomic analysis. (2) We observed low levels of TGF-β path-