3 research outputs found
Mitotane Targets Lipid Droplets to Induce Lipolysis in Adrenocortical Carcinoma
INTRODUCTION
Adrenocortical carcinoma (ACC) is a rare aggressive cancer with low overall survival. Adjuvant mitotane improves survival but is limited by poor response rates and resistance. Mitotane's efficacy is attributed to the accumulation of toxic free cholesterol, predominantly through cholesterol storage inhibition. However, targeting this pathway has proven unsuccessful. We hypothesize that mitotane-induced free-cholesterol accumulation is also mediated through enhanced breakdown of lipid droplets.
METHODOLOGY
ATCC-H295R (mitotane-sensitive) and MUC-1 (mitotane-resistant) ACC cells were evaluated for lipid content using specific BODIPY dyes. Protein expression was evaluated by immunoblotting and flow cytometry. Cell viability was measured by quantifying propidium iodide-positive cells following mitotane treatment and pharmacological inhibitors of lipolysis.
RESULTS
H295R and MUC-1 cells demonstrated similar neutral lipid droplet numbers at baseline. However, evaluation of lipid machinery demonstrated distinct profiles in each model. Analysis of intracellular lipid droplet content showed H295R cells preferentially store cholesteryl esters, whereas MUC-1 cells store triacylglycerol. Decreased lipid droplets were associated with increased lipolysis in H295R and in MUC-1 at toxic mitotane concentrations. Pharmacological inhibition of lipolysis attenuated mitotane-induced toxicity in both models.
CONCLUSION
We highlight that lipid droplet breakdown and activation of lipolysis represent a putative additional mechanism for mitotane-induced cytotoxicity in ACC. Further understanding of cholesterol and lipids in ACC offers potential novel therapeutic exploitation, especially in mitotane-resistant disease
Improved diagnosis of SARS-CoV-2 by using nucleoprotein and spike protein fragment 2 in quantitative dual ELISA tests
The novel coronavirus, severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), is the
causative agent of the 2020 worldwide coronavirus pandemic. Antibody testing is useful for
diagnosing historic infections of a disease in a population. These tests are also a helpful
epidemiological tool for predicting how the virus spreads in a community, relating antibody
levels to immunity and for assessing herd immunity. In the present study, SARS-CoV-2 viral proteins were recombinantly produced and used to analyse serum from individuals previously
exposed, or not, to SARS-CoV-2. The nucleocapsid (Npro) and spike subunit 2 (S2Frag) proteins
were identified as highly immunogenic, although responses to the former were generally greater.
These two proteins were used to develop two quantitative enzyme-linked immunosorbent assays
(ELISAs) that when used in combination resulted in a highly reliable diagnostic test. Npro and
S2Frag-ELISAs could detect at least 10% more true positive coronavirus disease-2019 (COVID-19) cases than the commercially available ARCHITECT test (Abbott). Moreover, our quantitative ELISAs also show that specific antibodies to SARS-CoV-2 proteins tend to wane rapidly even
in patients who had developed severe disease. As antibody tests complement COVID-19 diagnosis and determine population-level surveillance during this pandemic, the alternative diagnostic
we present in this study could play a role in controlling the spread of the virus
Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome
Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease