Accumulating evidence suggests the involvement of tumor-derived exosomes in the development and recurrence of hepatocellular carcinoma (HCC). We previously identified miR-4669 as a highly expressed microRNA in circulating exosomes obtained from patients with post-transplant HCC recurrence. This study aimed to explore how overexpression of miR-4669 affects HCC development and recurrence. The impact of miR-4669 overexpression in Hep3B cells on tumor cell behavior and the tumor microenvironment was evaluated in vitro. In addition, the clinical value of exosomal miR-4669 for the prediction of treatment response to HCC downstaging therapies and following post-transplant HCC recurrence was explored. Overexpression of miR-4669 enhanced migration ability and led to acquired sorafenib resistance with an elevation of sirtuin 1 and long noncoding RNA associated with microvascular invasion. Active release of tumor-derived exosomes and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) contributed to generating an immunosuppressive tumor microenvironment through the induction of M2 macrophage polarization. The retrospective analysis demonstrated the clinical value of exosomal miR-4669 for predicting treatment response to HCC downstaging therapies and for risk assessment of post-transplant HCC recurrence. In summary, the present data demonstrate the impact of exosomal miR-4669 on HCC recurrence through the enhancement of tumor aggressiveness and generation of an immunosuppressive tumor microenvironment.

(1) Background: Alpha-fetoprotein (AFP) has been incorporated into the selection criteria of liver transplantation and been used to predict the outcome of hepatocellular carcinoma (HCC) recurrence. Locoregional therapy (LRT) is recommended for bridging or downstaging in HCC patients listed for liver transplantation. The aim of this study was to evaluate the effect of the AFP response to LRT on the outcomes of hepatocellular carcinoma patients after living donor liver transplantation (LDLT). (2) Methods: This retrospective study included 370 HCC LDLT recipients with pretransplant LRT from 2000 to 2016. The patients were divided into four groups according to AFP response to LRT. (3) Results: The nonresponse group had the worst 5-year cumulative recurrence rates whereas the complete-response group (patients with abnormal AFP before LRT and with normal AFP after LRT) had the best 5-year cumulative recurrence rate among the four groups. The 5-year cumulative recurrence rate of the partial-response group (AFP response was over 15% lower) was comparable to the control group. (4) Conclusions: AFP response to LRT can be used to stratify the risk of HCC recurrence after LDLT. If a partial AFP response of over 15% declineis achieved, a comparable result to the control can be expected.

Background: Active vaccination has been utilized to prevent de novo hepatitis B virus infection (DNHB) in anti-HBc (+) grafts after liver transplantation. However, the long-term efficacy of active vaccination and graft/patient outcomes of anti-HBc (+) grafts have yet to be comprehensively investigated. Materials and methods: Among 204 pediatric patients enrolled in the study, 82 recipients received anti-HBc (+) grafts. For DNHB prevention, active vaccination was repeatedly administered prior to transplant. Antiviral therapy was given to patients with pretransplant anti-HBs 1000 IU/ml, while antiviral therapy was not given in patients with an anti-HBs titer over 1000 IU/ml. The primary outcome was to investigate the long-term efficacy of active vaccination, while the secondary outcomes included the graft and patient survival rates. Results: Among the 82 anti-HBc (+) transplant patients, 68% of recipients achieved a robust immune response, thus not requiring antiviral therapy. Two patients (2.4%) developed DNHB infection, one of which was due to an escape mutant. With a median follow-up of 150 months, the overall 10-year patient and graft survival rates were significantly worse in recipients of anti-HBc (+) grafts than those of anti-HBc (-) grafts (85.2 vs 93.4%, P=0.026; 85.1 vs 93.4%, P=0.034, respectively). Additionally, the 10-year patient and graft outcomes of the anti-HBc (+) graft recipients were significantly worse than those of the anti-HBc (-) graft recipients after excluding early mortality and nongraft mortality values (90.8 vs 96.6%, P=0.036; 93.0 vs 98.3%, P=0.011, respectively). Conclusion: Our long-term follow-up study demonstrates that active vaccination is a simple, cost-effective strategy against DNHB infection in anti-HBc (+) graft patients, whereby the need for life-long antiviral therapy is removed. Notably, both the anti-HBc (+) grafts and patients exhibited inferior long-term survival rates, although the exact mechanisms remain unclear.

The field of hyperspectral imaging (HSI) has progressed exponentially since its inception in 1972 and is applied to various research fields including agriculture, food quality and archeology. The purpose of the technology is to acquire images containing spatial and spectral data that can be used for detection and/or identification purposes. Our goal was to use HSI technology to differentiate between 3 different bacteria that are common foodborne organisms in 3 phases of growth: log, late log and stationary. For our study we used the Cytoviva hyperspectral imaging system to extract the individual hyperspectral profiles produced by Salmonella enterica serotype Typhimurium, Escherichia coli O157: H7, and Listeria monocytogenes . All organisms were cultured in Brain Heart Infusion (BHI) broth, pelleted at 10,000× rpm and washed in 1× PBS buffer prior to imaging. 0.8 μL of each sample was transferred to a poly‐l‐lysine coated slide for immobilization and topped with a glass cover slip to extract the profiles of each organism. Our protocol was enhanced to extract spectral profiles of intact live microorganisms. Data is collected by the pushbroom approach through which an image is made that has both hyperspectral and spatial data by moving the sample pixel line by pixel line to produce distinct profiles for each specimen. The use of a patented enhanced darkfield condenser in conjunction with high resolution optical and hyperspectral imaging creates sharp spectral profiles based upon the unique surface chemistries of each organism. The hyperspectral profiles of the cells were composed from each image through the ENVI software. The unique spectral graphs produced by each organism appear to align with increased growth, especially at the 24 hour time point. However, these organisms do exhibit different hyperspectral patterns at each time point and they are not the same for any organism. Hyperspectral imaging has the potential to be used as a rapid diagnostic tool that does not damage the sample while reporting data that can be shared and analyzed by multiple people at the same time. Support or Funding Information This work was supported in part by a grant from the Lake Erie College of Osteopathic Medicine, USA, Department of Biological Sciences and Department of Anatomy, Physiology and Pharmacology at Auburn University. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .