Hep B Blog

Tag Archives: HBV related liver cancer

Hepatitis B Research Review

 

 

 

 

Welcome to the Hepatitis B Research Review! This monthly blog shares recent scientific findings with members of Baruch S. Blumberg Institute (BSBI) labs and the hepatitis B (HBV) community. Technical articles concerning HBV, Hepatocellular Carcinoma, and STING protein will be highlighted as well as scientific breakthroughs in cancer, immunology, and virology. For each article, a brief synopsis reporting key points is provided as the BSBI does not enjoy the luxury of a library subscription. The hope is to disseminate relevant articles across our labs and the hep B community. 

Interferon-inducible MX2 is a host restriction factor of hepatitis B virus replication Journal of Hepatology

  • This paper from Fudan University in Shanghai, China reports the interferon-induced GTPase MX2 as a host protein which inhibits HBV replication. Interferon alpha (IFN-α) is a type 1 interferon used in a subset of HBV-infected patients to help eradicate the virus. IFN-α treatment results in the activation of hundreds of genes known as interferon-stimulated genes (ISGs). Which ISGs are most important in eliminating HBV infection remain largely unknown. GTPases are a large family of hydrolase enzymes which convert guanosine triphosphate (GTP) to guanosine diphosphate (GDP). GTPases act as molecular switches in an array of cellular process including signal transduction, cell division and differentiation, and protein translocation. The myxovirus resistance (Mx) proteins are highly conserved, dynamin-like, large GTPases. Humans have two MX proteins: MX1 and MX2, both of which are known ISGs. While MX1 is known to have broad-spectrum antiviral activity against RNA viruses, MX2 has only recently been shown to inhibit human immunodeficiency virus 1 (HIV-1), hepatitis C virus (HCV), and hepesviruses. MX2 antiviral activity against HIV-1 and herpesviruses is mediated through MX2 binding to the capsid of invading viruses whereby it likely inhibits the uncoating of viral DNA. In HCV, MX2 was found to interact with non-structural protein 5A (NS5A) thereby inhibiting its localization to the endoplasmic reticulum (ER). MX1 has been reported to inhibit HBV replication by inhibiting nuclear export of viral RNas and/or trapping the HBV core protein indirectly. This study investigates the anti-HBV activity of MX2. First, the group compared the anti-HBV activity of MX2 to four other innate immune restriction factors: HNRNPU, SAMHD1, MOV10 and A3G. They co-transfected these genes along with the HBV genome into HUH-7 cells and then assessed HBV replication via Southern blot. MX2 was found to inhibit HBV replication the most, with 44% of viral DNA compared to the empty vector control. The group then used siRNA, Southern blot, Western blot, fractionation, and mutagenesis studies to elucidate the anti-HBV role of MX2. Overall, they found that MX2 significantly reduces HBV RNA levels and indirectly impairs cccDNA formation. MX2 was found to contribute substantially to the anti-HBV affect of  IFN-α. Both the GTPase activity and oligomerization status of MX2 were found to be important in conferring its anti-HBV affect. In the future, MX2 and its related pathways may be exploited to help prevent the formation of and even eliminate cccDNA in those infected with HBV.

An HBV-encoded miRNA activates innate immunity to restrict HBV replication – Journal of Molecular Cell Biology

    • This paper from the Tianjin Medical University in China explains how an HBV-encoded microRNA (miRNA) activates the innate immune system in humans infected with the virus. miRNAs are short (21-25 nucleotides) sequences of mRNA which are mainly involved in post-transcriptional silencing of genes. miRNAs are produced in plants, animals, bacteria, and viruses. Typically, miRNA acts to silence protein translation from a messenger RNA (mRNA) by binding to the 3′ untranslated region (UTR) of the mRNA. This binding may result in the destabilization or cleavage of the mRNA or inhibit the function of the ribosome during translation. This group has identified an miRNA from the HBV genome called HBV-miR-3 which they have previously reported inhibits HBV replication by targeting the HBV mRNA transcript. In this paper, the group first shows that HBV-miR-3 is produced in an amount proportional to virus infection in vitro. They also show that HBV-miR-3 is secreted from cells in exosomes. Next, using both patient serum samples and in vitro assays, the group found a positive correlation between HBV-miR-3 production and IFN-α signaling pathways. In patient serum, levels of HBV-miR-3 positively correlated with levels of the hepatitis-related parameters alanine aminotransferase (ALT), aspartate transaminase (AST) and type I IFNs (IFN-α and IFN-β). In cell culture, they observed an increased expression of  the IFN-α-induced antiviral effectors OAS-1, MX1, IFIT2 and IFIT3 in the context of HBV-miR-3 production. Further experiments indicated that HBV-miR-3 promotes IFN-α production by suppressing the expression of suppressor of cytokine signaling 5 (SOCS5), allowing for signal transducer and activator of transcription 1 (STAT1) to be activated by phosphorylation. Finally, the group shows that HBV-miR-3 released from infected cells in exosomes  promotes polarization of the M1 macrophage phenotype. M1 or “classically activated” macrophages secrete high levels of pro-inflammatory cytokines and thereby fight pathogenic infections. Taken together, these results show that aside from directly limiting HBV replication, HBV-miR-3 also indirectly limits HBV infection by activating the host innate immune system. The virus may do this in order to adopt host miRNA-mediated antiviral machinery and thereby alleviate pathogenesis so that persistent and latent infection can continue. In the future, levels of HBV-miR-3 may be used as a diagnostic marker for HBV infection and may shed light on novel antiviral approaches.

Innate and adaptive immunity associated with resolution of acute woodchuck hepatitis virus infection in adult woodchucks – PLOS Pathogens

    • This paper from Georgetown University in Washington, DC is a “woodchuck paper”. That is, it is an in vivo study of woodchucks infected with Woodchuck Hepatitis Virus (WHV). WHV infection is used as a model system for HBV infection in humans because WHV is similar to HBV. This type of study is beneficial, especially when studying the immune response to hepadnaviruses, because humans infected with HBV are typically asymptomatic in the early stage of infection and because it is not advisable to obtain liver biopsies from these patients. The woodchuck infection model offers a controlled infection with WHV at a known time-point, which can be monitored by regular blood tests and liver biopsies. When studying the immune response to hepadnaviruses, liver biopsies are necessary because the liver is the site of the infection. About 95% of adults infected with HBV “clear” the virus; that is, their immune system is able to fight off the virus completely, giving them life-long immunity. The other 5% become chronic carriers of HBV and are at a high risk for liver cirrhosis and hepatocellular carcinoma (HCC). However, 95% of infants infected with HBV become chronic carriers. Differences in the immune systems of adults vs infants have been attributed to this drastic difference in chronicity, but what specific components of the immune system are important in staving off chronic infection remain unknown. Overall, the data presented here indicate that there is an early, non-cytolytic control of WHV replication mediated by interferon gamma (IFN-γ) produced mainly by natural killer (NK) cells. This was followed by an adaptive immune response characterized by antibody production, a T-cell response, and cytolytic action of cytotoxic T lymphocytes (CTLs). This adaptive immune response led to both the decline of WHV as well as symptoms of acute hepatitis B (AHB) including sinusoidal and portal inflammation in the liver.

Differential alternative splicing regulation among hepatocellular carcinoma with different risk factors BMC Medical Genomics

    • This paper from the University of Utah School of Medicine in Salt Lake City, Utah uses bioinformatics to examine how different risk factors for hepatocellular carcinoma (HCC) correlate with differential alternative splicing (AS) of tumor mRNAs. After a primary (precursor) mRNA transcript is produced in the nucleus by RNA polymerase, the transcript must “mature” by having regions called “exons” removed in a process called splicing. Splicing results in an mRNA transcript consisting entirely of “introns”. The mRNA is then capped at its 5′ end with a 7-methylguanosine residue and polyadenylated at its 3′ end with about 200 adenylate residues (poly-A tail). This mature mRNA is able to exit the nucleus and be translated into protein by a ribosome. Alternative splicing (AS) describes how one genomic region may code for many different protein variants (isoforms) by differential spicing of the primary mRNA transcript. A common mechanism of AS is “exon skipping”, where exons are included in some mature transcripts but not others. HCC has various risk factors including alchohol consumption and infection with hepatitis B or C viruses (HBV and HCV). This study used data from The Cancer Genome Atlas (TCGA) and  the Genomic Data Commons (GDC) Data portal to analyze 218 patients with primary HCC associated with HBV (n = 95), HCV (n =47), or alcohol (n = 76). They used RNA sequencing (RNA-Seq) data to examine differences in AS between three groups: HBV vs. HCV, HBV vs. alcohol, and HCV vs. alcohol. 143 genes were identified with differential AS across these groups and these genes were found to be mainly involved in immune system, mRNA splicing-major pathway, and nonsense-mediated decay pathways.Of the 143 AS genes identified, eight and one gene were alternatively spliced specific to HBV and HCV respectively. The human leukocyte antigen genes HLA-A and HLA-C had differential AS in HBV-related HCC compared to both HCV- and alchohol-related HCC. HLA ptoteins are part of the major histocompatibility complex (MHC) class 1 surface proteins which present foreign antigens to the immune system. Also, exon 3 of  the gene encoding inositol hexakisphosphate kinase 2 (IP6K2) was skipped more often in HBV-related HCC than in other groups. IP6K2 is known to be involved in cancer metastasis. This study represents the first investigation into how different risk factors of HCC may affect the AS status of specific genes.

The Cytosolic DNA-Sensing cGAS–STING Pathway in Cancer (Review) Cancer Discovery

    • This review from the Memorial Sloan Kettering Cancer Center in New York City covers current understanding of the cGAS-STING pathway in the context of cancer. While it is well known that the cGAS-STING pathway is an evolutionarily-conserved  antiviral signaling platform, how this pathway is involved in tumorigenesis remains unclear. In preneoplastic (early tumor) cells, cGAMP produced in response to DNA damage is exported out of the cell to activate STING in neighboring antigen-presenting cells (APC). This activation results in the release of type 1 interferon (IFN) from the APC, which cross-primes natural-killer and CD8 T-cells to kill the preneoplastic cells. In this context, the cGAS-STING pathway plays a role in tumor surveillance by activating innate immunity to create “hot spots” of inflammation. However, there is also evidence that activation of the cGAS-STING pathway can contribute to tumorigenesis.  In advanced, metastatic tumor cells, chronic activation of STING by chromosomal abnormalities leads to suppressed production of IFN and the upregulation of Nf-kB-driven pro-survival genes. This can drive chronic inflammation of the tumor as well as its metastasis to other locations in the body. Activation of the STING pathway in tumor cells may also allow for their immune evasion by inducing autophagy and upregulating expression of programmed death-ligand 1 (PD-L1). Another interesting finding mentioned in this review is a STING-independent form of cGAS activation which may drive tumorigenesis during cell division. During mitosis, cytoplasmic cGAS may bind to repeat sequences in the centromere regions of chromosomal DNA. Once bound, cGAS may interrupt the repair of sister chromatids by homologous recombination, causing aneuploidy in daughter cells, a hallmark of tumor cells. Of additional interest, mentioned in this review are several recent findings regarding the cGAS-STING pathway, including: cGAS can be activated by extracellular DNA entering the cell in exosomes; cGAS can be activated by “micronuclei” which are small nuclear compartments in the cytoplasm formed by chromosomal instability; cGAS-DNA complexes turn into a liquid phase to produce cGAMP; STING dimers oligomerize to form tetramers when activated; palmitoylation of STING has been proposed to recruit TANK binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3).

Lay Summary: 
This month, the innate immune system was the focus of HBV research. Scientists hope to find how the innate immune system interacts with HBV during viral infection and proliferation. Doing so will shed light on host factors which lead to chronic infection and inform antiviral strategies. Notably, this month a human protein, MX2 was found to have potent anti-HBV activity by preventing cccDNA formation. Also, a microRNA encoded by HBV called HBV-miR-3 was found to activate the human innate immune system to limit HBV replication. This month, a paper studying woodchuck hepatitis virus (WHV) traked activation of the innate immune system as well as he adaptive immune system in an acute infection model. Also this month, concerning hepatocellular carcenoma (HCC), the alternative splicing of mRNA in tumors was found to vary in HCC patients based upon their risk factor (HBV, HCV, or alcohol). Finally, a review was published this month concerning STING, an innate immune protein which is not activated by HBV infection but which may prove a valuable tool for cancer treatment.  

Meet our guest blogger, David Schad, B.Sc., Junior Research Fellow at the Baruch S. Blumberg Institute studying programmed cell death such as apoptosis and necroptosis in the context of hepatitis B infection under the direction of PI Dr. Roshan Thapa. David also mentors high school students from local area schools as part of an after-school program in the new teaching lab at the PA Biotech Center. His passion is learning, teaching and collaborating with others to conduct research to better understand nature.

Protecting Yourself From Liver Cancer While Living with Hepatitis B

This Liver Cancer Awareness Month, we are connecting the dots between hepatitis B and liver cancer. Hepatitis B is responsible for up to 60% of all liver cancer cases worldwide. In fact, some of the highest rates of liver cancer are found in places with extremely high rates of hepatitis B, such as sub-Saharan Africa and Southeast Asia. Although liver cancer is the sixth most common cancer in the world, it is the second most common cause of cancer deaths. Liver cancer prevention should be a priority for all living with hepatitis B. Luckily, there are steps that you can take to prevent liver cancer – whether you are living with hepatitis B or not! 

The Importance of Regular Check-Ups

Did you know that a chronic hepatitis B infection can lead to liver cancer without signs of previous damage such as cirrhosis?  Many people do not realize that chronic hepatitis B is the primary global risk factor for developing liver cancer. Cirrhosis – or scarring or the liver – is often a risk factor for liver cancer, but it is not always the case for those living with hepatitis B. This is one of the reasons why it is so important for family members and sexual partners of infected individuals to get tested as well! Lack of symptoms does not mean that damage is not occurring. 

Visiting a doctor regularly is the best way to prevent liver cancer if you are living with hepatitis B. The standard recommendation for visiting your doctor is every six months however this can vary based upon the severity of your infection. The doctor will take a few blood tests, along with an ultrasound examination of the abdominal area to determine the health of the liver. Based upon these tests and other risk factors, the doctor will be able to determine if liver damage is occurring and can guide you on which steps you should take next. 

If damage is detected early enough, progression to liver cancer can be prevented through highly effective treatments that stop or slow the virus from reproducing in your liver. However, it is important to note that not everyone living with hepatitis B needs treatment. Current treatments have been proven to be most effective when there are signs of active liver damage. Hepatitis B can be managed through regular monitoring by a knowledgeable doctor and lifestyle changes that can go a long way in protecting your body. 

Early detection of liver cancer is extremely important. The average 5-year survival rate once diagnosed with liver cancer ranges from 10% -14%. However, with early detection and proper treatment, those numbers rise to over 50%! This significant difference is because if liver cancer is caught early, a doctor can link you to life-saving treatments including chemotherapy, surgical options, ablation techniques, intra-arterial therapies or a liver transplant. Regular monitoring by a knowledgeable doctor will hopefully identify the markers of liver cancer before it occurs, but if you are living with liver cancer, there are treatment options and resources available to you. 

Preventing Liver Cancer 

Educating oneself is the first step in prevention! If you have hepatitis B, be aware of the risk factors and behaviors that can increase your likelihood of liver damage and liver cancer, such as consuming alcohol and high amounts of junk food, and lack of exercise. Non-Alcoholic Fatty Liver Disease (NAFLD) can also increase your risk of cancer, so it is important to discuss NAFLD risk factors and prevention tips with your doctor. Groups such as the CDC Division of Viral Hepatitis and the American Association for the Study of Liver Diseases all provide free fact sheets, call lines, and literature by experts that can help you understand what may be occurring in your body and to make educated choices. You can also check out our Liver Cancer Connect resource for more information or for liver cancer support. 

The hepatitis B vaccine is also the first anti-cancer vaccine ever created! Remember that the vaccine is typically given in a set of 3 doses. It is extremely important to take all three in order to receive lifelong protection from hepatitis B-related liver cancer. In the U.S., there is also a 2-dose vaccine available, so you can be fully protected with fewer doses! If you are worried about the cost of the birth dose for your infant or the vaccine for yourself, many countries have free health clinics that can administer it or link you to an organization that can help. 

Another key to preventing liver cancer is to get tested for hepatitis B. If you have not received your vaccine and you think you fall into a high-risk group, talk to your doctor about getting tested. Because hepatitis B often has no symptoms, it is important to get screened even if you do not feel ill. An early diagnosis means that you can begin any needed treatment sooner and prevent irreversible damage from occurring. Like the vaccines, your local doctor or health clinic may be able to test you for free or reduced cost – just ask! Some local community groups also provide free hepatitis B testing, so be sure to look out for flyers and announcements about them in your community as well

Karen and Dave’s Story

One Couple’s Journey through Hepatitis B, Hepatitis D and Liver Cancer

“Dave knew he had hepatitis B for decades, but honestly, no one ever seemed concerned. His liver
enzymes were slightly elevated, so the doctor told him to just watch what he ate and drank. He didn’t
even insist on bi-yearly blood tests!

In 2016, Dave was scheduled for a routine colonoscopy. Because he’d been looking pale and sickly
around that time, I suggested they do a blood test first at his family doctor. His numbers were off the
chart. They sent us back for the colonoscopy and added an endoscopy too. They found four varices
(enlarged veins in the esophagus that can indicate serious liver disease). How did this happen?

This was when I started to get angry. The gastroenterologist called us in to discuss the results. He asked
if Dave knew he had hepatitis B. Dave said yes, knowing his drug use in his teens and early twenties was
likely the source. Dave never felt shame about it at all, and just accepted it as a path he took, and
thankfully came out of. After that conversation, the doctor slammed his chart shut and pushed it across
the desk. He said that Dave’s liver was so badly damaged that there was nothing he could do and to
‘come back in a year’. When we asked about his options for treatment for the varices and his hepatitis B,
he actually told me that no one would treat the varices unless they were bleeding! He also told us that
hepatitis B antivirals would “make things worse”. That didn’t make sense. We asked about a transplant.
He said there was ‘no way’ anyone would give him a new liver. He didn’t even let us know that there
were actual liver clinics for this very purpose. He sent Dave away to die, really.

Many months later, with much perseverance, we made it to Stanford, where he was immediately put on
entecavir to treat his hepatitis B and to hopefully relieve some of his liver damage. That doctor alerted
us that he should also be tested for hepatitis D, a coinfection of hepatitis B. “It won’t be good if you have
it.” He did.

Due to changes in our health insurance, we were sent to continue at the University of California San
Francisco Liver Center…they were our saving grace. They treated the varices right away and put him on
other medications to help his failing systems. His hepatitis B viral load was now undetectable, with
hepatitis D being the biggest concern. Dave tried interferon to treat the hepatitis D, but with no luck. His
only chance was a transplant, but even though he was doing poorly, his test results didn’t qualify him to
get on the transplant list right away. He had lots of ER visits – 210 office visits in 2017 alone. It was a
whirlwind. Dave hadn’t even driven in 2 ½ years. It was an enormous stress on me, too.

Dave developed liver cancer but wasn’t in good enough shape to go through treatment. As he got sicker,
he eventually qualified for two different                  
liver transplant waiting lists. Finally, on
Thanksgiving night 2017, we got the call
that a healthy liver was available, and we
took it.
Caregiving is a very tough road. Especially
when your person also has encephalopathy,
caused by years of liver damage – and Dave
had it really bad. The encephalopathy
caused mood swings, short-term memory
loss, hand tremors, low appetite. He could
be down-right nasty. At that time, we were
doing the 4 ½ hour drive to San Francisco
once or twice a week. It was stressful for
both of us – and he was really unaware of
the stress that was put on me. Between
driving, taking out the garbage, bills, our
construction business…you name it, I did it
all.

The first 3-4 months out of the transplant, people were telling him all that had gone on. Much to my
frustration, he didn’t believe any of it! Now, over 6 months post-transplant, little things are coming back
to him. I showed him about 2 dozen pictures of him during his journey, and he was shocked! He said he
thought he was fooling everyone into thinking he was well.

The hardest part of this journey was seeing Dave so sick at times. I spent a lot of time in my closet
crying. It was hard on our adult girls too, to see their dad so weak and disoriented. I had a lot of support
through our girls though, and my family, which made a world of a difference. My sister is also a retired
nurse, and she accompanied us to most of our visits. She was a helpful adviser, since his medications
always needed tweaking, and we were often on long calls with our care team, health insurance
company, and pharmacies.

The good we took away is his health! He still doesn’t feel it’s real. We went through so much, and are so
grateful to be on the other side.

Things I’ve learned:
• Get on a Facebook forum for liver transplant patients…they are a great resource and a wealth of
information from other patients.
• Take a third person with you to doctor visits and procedures. At times, I was so consumed with
my concern for Dave, it was easy for me to forget some of the things we discussed. My sister
would take notes, and we would review them after.
• Always get a second opinion if you don’t have a good feeling about your doctor. You will all
become a team, and it’s important to have a team you can trust.
• Get on the transplant list at multiple hospitals, their criteria for transplant varies!
• Have willing family members and friends get tested to see if they are donor matches. Usually the
recipient’s insurance will pay for the testing and survey if they are a match. My sister-in-law and
I were both tested but were not a match.
• Ask about organ swap programs. Apparently, my kidneys were in perfect health. My
hepatologist had me apply to the kidney donor program, in hopes that I may be able to donate
my kidney in exchange for a piece of someone’s liver for Dave.
• Dave was put on depression and anxiety medication early in the process. He was initially very
resistant, mostly because of the stigma. His doctors finally convinced him it would be very
helpful for his general mood…it was!
• I had to make several phone calls to his team without his knowing. Encephalopathy really makes
you confused, and in Dave’s case, grumpy. I asked the doctor to push for the depression and
anxiety medications, which she did. Also, he wouldn’t exercise or take short walks before
surgery, which she had asked him to, to better prepare for surgery. I made the phone call, and
at the next visit, she set him up with a Fitbit! It helped that the ‘suggestions’ came from his
doctor and not me!
• After the transplant, I was so surprised he wasn’t more ‘thankful’ …that he wasn’t in awe of
what we had all gone through for HIM! I got angry with him. I made a private call to our new
post-transplant team. She said depression right after is very common. The patient feels
overwhelmed, and sometimes not very thankful. It’s kind of a way to deny they were in trouble,
to deny that they needed help. That fits my man to a tee!
• I would strongly suggest lots of patience after the transplant. I wish our team would have told
me the possible mental-state Dave might be in. Don’t force them to be thankful. Don’t play the
‘remember when’ game, “remember when I drove you to the ER in the middle of the night?
Remember when they told us you had cancer? Remember when I tried to be your donor?”
Because a lot of it he doesn’t remember.
• Take pictures along the way, but don’t show them until at least 6 months out. I showed Dave
pictures right away, and they didn’t resonate. I just showed him them the other night…and he
was floored! He really ‘got it’. He’s been looking at things differently lately: he’s calmer and
more loving.
• I wish I had kept a journal. The ups and downs of this journey were sometimes excruciating, and
Dave wasn’t ‘present’ to understand it. Hire cleaning help if needed. Get family and friends to
take the patient to lesser important appointments. Don’t let household things pile up on you. Fix
the gutter. Repair the screen. Hire a gardener for a few hours. Ask family to set things up for
you. It’s amazing how in two years without Dave to physically help around the house, things
started to go south pretty quickly! Luckily, I dug in and kept up.

Quite the journey for sure. I feel blessed to be on this side of health!”

– Karen

Antiviral Therapy May Prevent Liver Cancer in Hepatitis B patients

images-2

Useful confirmation of what we already thought was true. Good news…

(HealthNewsDigest.com) – DETROIT, June 9, 2014  —

Researchers have found that antiviral therapy may be successful in preventing hepatitis B virus from developing into the most common form of liver cancer, hepatocellular carcinoma (HCC).

That was the finding of a study published in the May issue of Clinical Gastroenterology and Hepatology. Investigators from Henry Ford Health System in Detroit, Geisinger Health System in Danville, Pa., and Kaiser Permanente in Honolulu, Hawaii and Portland, Ore. participated in the study, along with investigators from the Centers for Disease Control and Prevention in Atlanta.

According to the first-of-its-kind analysis of more than 2,600 adult participants with hepatitis B, those treated with antiviral therapy had a significantly lower occurrence of HCC during a five-year follow up period. Overall, 3 percent of patients developed HCC during the study’s timeframe. But patients who received antiviral therapy were 60 percent less likely to develop HCC than untreated patients.

“The results of this study allow us to reassure our patients that we are not just treating their viral levels, but that antiviral therapy may actually lessen their chance of developing liver cancer,” said the study’s lead investigator, Henry Ford Health System’s Stuart C. Gordon, M.D., who worked closely with Henry Ford Senior Scientist Mei Lu in Detroit. Continue reading here.