If you’ve ever wanted to help guide the future of hepatitis B treatments, now is your chance! The Hepatitis B Foundation has created a short survey that is designed to capture a comprehensive view of the patient experience. The survey, which takes approximately 20-25 minutes to complete, will be made available for use by the US Food and Drug Administration (FDA) and drug development researchers to help clinical trial development for future hepatitis B therapies. All survey responses are anonymous.
All individuals living with chronic hepatitis B are welcome to take this survey! After answering a few standard questions, participants will be asked whether or not they are currently on treatment for hepatitis B. If they are on treatment, the survey will prompt the participant to answer a few questions about their experience with the medication, such as how it makes you feel to take it,
and what challenges you may face while taking your medication. All participants, regardless of their current treatment status, will have an opportunity to provide feedback on what they hope future medications will look like!
The patient perspective is essential to creating a treatment that is not only effective but something that those living with hepatitis B would be willing to take. Oftentimes, researchers do not have the opportunity to gather insight into what patients are looking for or how a therapy would impact their lives. This can result in missed dosages of a medication, or avoiding a therapy altogether, rendering the treatment ineffective. This survey is also unique because it seeks to capture the diverse experiences of global patients living with hepatitis B. As we want to ensure that new treatments are as universal as possible, gathering the thoughts of both international and national individuals will ensure that different voices and opinions are captured!
The survey is the first part of a multistep process to collect information on the patient experience. In the upcoming months, we will carry out focus groups and interviews to have a better understanding of what it is like to live with hepatitis B, its impact on a person’s daily life, and more. The information collected will help to direct our patient-focused drug development meeting – a chance for stakeholders and those living with hepatitis B to meet and discuss the patient perspective – in June 2020.
The work being done will result in a broader understanding of how individuals are affected by the disease and more informed decisions regarding future hepatitis B therapies. Help guide the future of hepatitis B clinical trials and drug development by taking the survey today!
Eiger is currently working on two new drugs for hepatitis delta; Lonafarnib and Pegylated Interferon Lambda, which are both currently inphase 3 clinical trials. Lonafarnib is a new type of treatment that attempts to control hepatitis delta through a new method: through blocking a key enzyme that is needed for the hepatitis delta virus to replicate. Blocking this enzyme prevents a new virus from being created, which may control and even cure hepatitis delta.
Lambda is being developed as a better tolerated interferon compared to interferon alfa (IFN alfa). Interferons work by stimulating the body’s own immune system to fight the virus. Pegylated interferon alpha, which is the only current treatment for hepatitis delta, is a difficult treatment to tolerate, with many patients experiencing unpleasant side-effects. Lambda utilizes the same method of treatment as IFN alfa, in combination with a new strategy, which stimulates an immune response and targets receptors in the liver, which may reduce side effects and result in improved tolerability.
Below is Eiger Biopharmaceuticals’ response to a series of questions we posed to them.
1. Lambda is an immunomodulator and Lonafarnib is a prenylation inhibitor. Can you explain in laymen’s terms the mechanism for these drugs and how they work?
Eiger’s wording: Lonafarnib is a well-characterized, first-in-class, orally active inhibitor of an enzyme that is key to a vital process in the life cycle of HDV. Inhibiting this enzyme blocks the ability of HDV to assemble and package viral particles. Currently approved nucleos(t)ide treatments for HBV only suppress HBV DNA, do not affect HBsAg, and have no impact on HDV infection.
Lambda is being developed as a better tolerated interferon compared to interferon alfa (IFN alfa). Lambda is a well-characterized, first-in-class, type III interferon (IFN) that stimulates immune responses that are critical for the development of host protection during viral infections. By targeting receptors that are localized in the liver, Lambda treatment may reduce side effects and result in improved tolerability .
Can you share, in simple terms, the basic results of Eiger phase 3 studies for hepatitis delta trials? Are these drugs equally effective in HBeAg positive and negative HBV patients?
The Eiger Phase 2 LOWR program with Lonafarnib has been completed. Over 120 patients were dosed in Phase 2 dose-finding studies to identify combination regimens of lonafarnib (LNF) and ritonavir (RTV) with and without pegylated interferon-alfa (PEG IFN α), with efficacy and tolerability to enable viral load suppression of HDV RNA and ALT normalization at Week 24.
Dosing regimens of LNF 50 mg twice daily + RTV 100 mg twice daily with and without PEG IFN-a-2a 180 mcg once weekly were identified with the following reported results:
All-oral: Lonafarnib boosted with ritonavir
29% of patients achieved ≥ 2 log decline and ALT normalization
Combination: Lonafarnib boosted with ritonavir + PEG IFN-a-2a
63% of patients achieved ≥ 2 log decline and ALT normalization
These dosing arms are being further studied in the global Phase 3 D-LIVR study. Phase 2 studies have not been stratified by HBeAg status.
The D-LIVR Study, a Phase 3 pivotal trial, is on-going and evaluating the safety and efficacy of lonafarnib treatments in patients chronically infected with Hepatitis Delta Virus (HDV). Topline Week 48 data will be available in 2021.
2. How will Lambda and Lonafarnib be administered to patients?
Lonafarnib capsules are administered orally twice daily by mouth. Lonafarnib is taken in combination with ritonavir, a therapeutic booster that increases the bioavailability of lonafarnib. Ritonavir tablets are administered orally twice daily by mouth.
Pegylated interferon-lambda is administered as a self-administered subcutaneous injection once weekly.
3. Do you anticipate combination therapy will be needed and if so, which combinations do you anticipate?
No form of viral hepatitis has been cured with a single drug. Combinations of treatments with different mechanism of actions have always been required.
Lonafarnib and interferons have different mechanisms of action and have been studied as monotherapies and in combination together as treatments for HDV. While each treatment alone reduces the HDV viral load, combination studies have shown that using these treatments together leads to a synergistic effect and further reduces the HDV viral load.
Recently, the interim end of treatment results of peginterferon lambda (Lambda) and lonafarnib combination study in HDV-infected patients were presented at AASLD 2019. The LIFT study is being conducted within the National Institutes of Health (NIH) at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). LIFT is a Phase 2a open-label study of 26 adult patients with chronic HDV treated with Lambda 180 mcg once weekly in combination with Lonafarnib 50 mg twice daily boosted with ritonavir 100 mg twice daily for 24 weeks. Primary efficacy endpoint is > 2 log HDV RNA decline at end of treatment. At the time of analysis, 19 of 26 patients had reached Week 24. Median HDV RNA decline was 3.4 log IU/mL (IQR: 2.9-4.5, p<0.0001) with 53% (10 of 19) patients achieving below the limit of quantification and 37% (7 of 19) patients achieving undetectable HDV RNA at Week 24. 18 of 19 patients (95%) achieved primary endpoint of > 2 log decline during 24 weeks of therapy. We believe these data are the most encouraging yet in pursuit of HDV cure.
4. What kind of side effects can patients expect with Lambda and Lonafarnib, with or without combination therapy?
The most common side effects of lonafarnib include diarrhea, nausea, fatigue, decreased appetite, vomiting, abdominal pain, and decreased weight. Antacid, antiemetic, and antidiarrheal medications may be used prophylactically to treat these gastrointestinal side effects.
The most common side effects of pegylated interferon-lambda (Lambda) are the expected side effects of interferons. However, these side effects have been demonstrated to be much milder and less severe than what has been previously been shown with pegylated interferon-alfa (alfa). These include musculoskeletal (myalgia, arthralgia, and back pain), flu-like symptoms (chills, pyrexia, and pain) and elevated alanine aminotransferase (ALT) levels.
A combination of these side effects is expected with combination therapy.
5. Are Lambda and Lonafarnib safe for use in people with cirrhosis?
Currently, the safety and efficacy of lonafarnib and pegylated interferon-lambda are being investigated in persons chronically infected with HDV. The clinical trials require study participants meet certain eligibility criteria to be included in these studies. These eligibility criteria may or may not reflect the type of patient who will use these therapies after they receive FDA approval.
Phase 2 and Phase 3 studies both include patients with well-compensated cirrhosis.
6. With a clearance of HDV, would you also anticipate a loss of surface antigen – functional cure for chronic HBV as well? If so, in what percentage of HBeAg and HBeAb patients?
HDV is always found as a co-infection with HBV because HDV requires just a small amount of HBV surface antigen (HBsAg) to complete HDV viron replication. However, an HDV / HBV coinfection leads to much more severe chronic viral hepatitis compared to HBV monoinfection alone. Therefore, it is important to treat HDV, even if HBV is not cured. It is possible to clear HDV RNA without loss of HBsAg.
7. Lambda and Lonafarnib are currently in phase 3 trials for delta. Are you able to provide an approximate timeline for when it will be approved for use in U.S. and Europe?
Eiger BioPharmaceuticals is committed to developing safe and effective therapies for HDV and providing patients with a pathway to gain access to approved therapies as quickly as possible.
The D-LIVR Study is a global study that is evaluating the safety and efficacy of lonafarnib treatment in patients chronically infected with HDV. The D-LIVR Study is recruiting subjects in up to 20 countries in over 100 study sites. The D-LIVR study includes 48 weeks of treatment with two different lonafarnib-based treatment regimens, followed by 24 weeks of follow-up. Primary endpoint is ≥ 2 log decline and ALT normalization at Week 48. Topline data from the Phase 3 D-LIVR study will be available in 2021. For more information about study locations and eligibility, please visit www.clinicaltrials.gov (NCT03719313).
End of Phase 2 meeting with FDA to discuss Phase 3 development with Lambda monotherapy is planned for Q1 2020.
Nigeria, with an estimated population of 190 million people, has a Hepatitis B prevalence of 8.1% and Hepatitis C at 1.1%, based on a recent Nigeria HIV/AIDS Indicator and Impact Survey(NAIIS) report. The NAIIS survey was a National house-hold based Survey that assessed the prevalence of HIV and related health indicators including the national prevalence of two additional blood-borne viruses: Hepatitis B virus and Hepatitis C virus. This gives an estimated number of about 19 million Nigerians living with Hepatitis B and or C.
The large population and relatively high prevalence rates of hepatitis B and hepatitis C, suggest that Nigeria should be considered a key country for hepatitis elimination efforts. Nigeria’s population was estimated at over 190 million in 2017, and growing rapidly, with projections suggesting it will surpass the United States to become the third most populous country in the world by 2050
The Journey to Hepatitis Elimination in Nigeria
In 2018, Patient groups and members of the World Hepatitis Alliance under the umbrella of the Civil Society Network on viral hepatitis in Nigeria partnered with the Federal Ministry of Health, and World Health Organization (WHO) to organize the 1st Nigeria
Hepatitis Summit in Abuja, FCT. The meeting was the flagship event in the country that brought together 26 states Ministry of health officials, academia, and civil society groups to engage on ways to accelerate hepatitis elimination in the country. The event was supported by Gilead Sciences and Roche Products Limited, with technical support from Clinton Health Access Initiative.
In May 2019 as a follow up to the Summit, the National Viral Hepatitis Control Program, convened the first Review meeting of all Hepatitis Desk officers across Nigeria in Abuja, with the active participation of the civil society groups in the event. The meeting was organized to review the Hepatitis Treatment facilities directory and share best practices among key actors.
In response to high prevalence rates and in alignment with the global effort towards elimination, The Nigerian Ministry of Health developed the National Viral Hepatitis Strategic Plan 2016 to 2020, which maps out actions to put Nigeria on the path of hepatitis elimination. National guidelines for the prevention, care and treatment of viral hepatitis B and C were also developed and published in 2016, which centre on firmly establishing the management of viral hepatitis as part of universal health coverage. Although there is a paucity of data on modes of viral hepatitis transmission within Nigeria, local intelligence suggests that there are some modes of transmission that are particularly relevant, including mother-to-child transmission, healthcare related transmission due to poor infection control and traditional cultural practices, including scarification, female genital mutilation, male circumcision, and uvulectomy.
However, whilst this political will and strategic direction are promising, there remain substantial challenges to the realisation of these plans and the attainment of elimination goals in Nigeria.
Although there have been efforts to work towards universal health coverage in Nigeria, the health system has limited funding, and there is a need for coordination between the levels of government.
Challenges to accessing health care in Nigeria
Although guidelines and strategic direction have been developed to guide Nigeria’s response to viral hepatitis, important barriers remain in place, which must be surmounted to reach elimination targets. These include geographical and financial barriers to accessing testing and treatment and the availability of alternative tests and treatment providers that lack connection with the health system and efficacy for treatment outcomes.
Service barriers to hepatitis care
The allocation of health care resources, including the health care workforce, in Nigeria, is skewed towards secondary and tertiary services, which are predominantly situated in urban areas. Currently, the majority of hepatitis treatment in Nigeria is provided at tertiary level services, which are not easily accessible to large parts of the population.
Financial barriers to hepatitis care
For Nigerians that are able to access health care services, significant financial barriers remain to access testing and treatment for hepatitis. Despite an effort to develop a system of universal health coverage, the majority (approximately 70%) of health spending for health in Nigeria still comes from private expenditure. The majority
of this is out-of-pocket spending, with only a small minority of Nigerians (approximately 4-5%) covered by health insurance. Costs of testing and treatment pose significant barriers to accessing viral hepatitis care, as tests, treatments, and vaccines must be paid for privately, and there is often limited availability of supplies.
This barrier of cost in accessing the hepatitis continuum of care is the primary drive towards quackery and unethical practices perpetrated by some organizations and individuals in Nigeria, providing alternative herbal and relatively cheaper treatment options to vulnerable and gullible patients.
The l ack of social and financial risk protection for Nigerians in accessing hepatitis continuum of care leads to high levels of poverty, vulnerability, and inequality in health
Elimination efforts in Nigeria
Clinton Health Access Initiative (CHAI) to date is leading in providing access to affordable treatment for Hepatitis C patients in Lafiya, Nasarawa state, through its partnership with the
government. The program provides affordable HCV RNA @ $35 and generic DAAs/month @ $80/month. CHAI through its access program has succeeded in negotiating costs of HCV diagnostics in some health centres across Nigeria, such as Lagos, Abuja, and Kwara, where patients can access affordable HCV RNA tests.
Similarly, Taraba State Government in partnership with Roche Products is providing a Pegasys based HBV treatment program for Tarabans. The Yakubu Gowon Centre in partnership with Taraba state government is also providing affordable diagnostics and treatment on HCV for patients at its treatment locations in Takum local council of Taraba state. The centre recently donated some doses of DAAs for patients.
Birth-dose HBV vaccination: Nigeria has a coverage rate of about 51% birth-dose HBV vaccination rate in the country. Sadly, there are no HBV vaccination programs for at-risk populations such as Men who Have Sex With Men, health care workers, People Who Inject Drugs, Incarcerated Populations. There are no government-funded harm reduction projects for People Who Inject Drugs in Nigeria.
Over 80% of activities of civil society and patient groups in Nigeria are on-demand creation, awareness and testing and linkage to care for patients. In June 2019, Centre for Initiative and Development (CFID) and other civil society organizations in Nigeria received a donation of 120 doses of DAAs at the African Hepatitis Summit in Kampala, Uganda through the African Regional Board Member.
Nigeria and the 2030 target
Unless something drastic is done, Nigeria and most of Africa stands the risk of missing the SDGs Goal 3.3 and the WHO Global Health Sector Strategy on Viral Hepatitis Elimination target for 2030.
Nigeria, with its vast mineral, natural resources, and human capital, has what it takes to eliminate viral hepatitis by 2030. But what it lacks is the strong political will and financial commitment by governments at all levels to finance an elimination strategy!
1st Nigeria Hepatitis Summit Report, 2019
World Hepatitis Summit 2015. New data shows relentless rise in hepatitis deaths.
World Health Organization (WHO). Global Hepatitis Report 2017. Geneva: WHO, 2017.
WHO, 2016.WHO Global Health Sector Strategy for the Elimination of Viral Hepatitis: 2016-2030
World Health Organization (WHO). Global Hepatitis Report 2017. Geneva: WHO, 2017:Availableat:apps.who.int/iris/bitstream/handle/10665/255016/9789241565455-eng.pdf;jsessionid=9DECA1FF83BC4A8CAE3BE2649662?sequence=1
Centers for Disease C, Prevention. Progress in hepatitis B prevention through universal infant vaccination – China, 1997–2006. Morbidity and Mortality Weekly Report, 2007;56(18): 441–445
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 proteinwill 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.
This paper from Fudan University in Shanghai, Chinareports 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.
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.
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.
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.
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.
With a new year right around the corner, now is a great time to reflect upon the past year and plan for the one ahead! 2020 is the start of a new era, but it also means that we have just 10 more years left to reach the World Health Organization’s 2030 goal of eliminating viral hepatitis. Many strides have been made over the years. In order to truly work towards elimination, we need everyone’s help – including yours!
Take Care of Your Health: The hepatitis B virus and your liver health can change over time, making regular doctors’ appointments essential to staying healthy and preventing liver disease and possibly liver cancer. Take a few hours this January to sit down and schedule your healthcare appointments for the year. Following up with your healthcare provider will allow them to monitor the infection, identify any signs of liver damage, and prescribe treatment early, if needed, to prevent further damage.
If you were diagnosed with acute hepatitis B and recovered, there are steps you can take to take care of your health too! You – and your healthcare providers – should be aware of the risk of reactivation, and how to prevent it. Always read the warning labels on over-the-counter medications, and make sure that anyone prescribing medication to you is aware of your past infection.
Get involved: Researchers are working hard each day to find a cure for hepatitis B and while they do so, there are many other issues in the hepatitis B community that can be addressed with the help of people like you! If you are in the United States, you can join ouradvocacy network to be notified of opportunities to take action. If you are located in another country, get involved with the #NOhep campaign, or search for World Hepatitis Alliance members near you to see what activities you can take part in. It’s essential for us to work both within our own country and globally. When we work together, our voices will be heard!
Get tested – or encourage others to: Despite being the most common liver disease in the world, just 10% of those infected are aware that they are living with hepatitis B. It is very important that people with hepatitis B are tested – especially because hepatitis B does not have any symptoms. Start small by encouraging your family members and loved ones to get tested or offering to go with a friend to their doctor’s appointment. If you want to help on a larger scale, you can volunteer with local health organizations who are active in the hepatitis community.
Perhaps your friends and family have already been tested and found out that they are not – and have never been – infected. That’s great! Now, it’s time to make sure that they get vaccinated to protect themselves. Remind them to schedule an appointment to receive their vaccine, and check in on them to make sure that they receive all necessary doses. Increasing global vaccination rates – especially in high-risk communities – is essential to meeting the 2030 elimination goals.
Put Your Social Media to Good Use: Technology is one of the best and most powerful communication tools that we have. Consider spreading positive, accurate messaging about hepatitis B in the new year to help destigmatize the disease, raise awareness, and combat false information. Start simple by liking, retweeting, and sharing posts by groups that are working hard to educate others! Be sure to follow reputable organizations so that the information you are receiving and passing on is correct! Join the Hepatitis B Foundation community on Facebook,Twitter, and Instagram for international updates and Hep B United on Facebook, Twitter, and Instagram for hepatitis B information in the United States!
For those of you who may be struggling to cope with your diagnosis or are dealing with stigma and discrimination around your diagnosis, the suggestions above may not be for you. Instead, consider taking 2020 to empower yourself by learning more about hepatitis B and sharing your experiences, even if you are only comfortable sharing anonymously. Remember, you are not alone! Over 292 million individuals are living with hepatitis B and each person has a story to tell.
The only way to fight stigma and discrimination is to make it known that it is unacceptable. Many of our #justB storytellers have faced the same obstacles that others are currently going through. Take some time in 2020 to watch some of our #justB storytelling videos that share the journeys of brave men and women who have found the strength to speak about their diagnosis and how hepatitis B has impacted their lives or family. Other global storytelling campaigns, such as the World Hepatitis Alliance’s #StigmaStops Campaign, or online support groups can provide support, too. However you decide to contribute to eliminating hepatitis B, your efforts will be appreciated!