Development of Oncolytic Adenoviruses for the Management of Prostate Cancer

Prostate cancer (PCa) is the fifth most common cause of cancer-related deaths in men globally. Androgen receptor (AR) signalling plays a vital role in initiation and progression and antiandrogens are standard of care first-line therapeutics. However, resistance frequently develops resulting in metastatic castration-resistant prostate cancer (mCRPC). Management of CRPC is currently chemotherapy and/or radiotherapy but is mostly palliative due to rapid development of resistance. The need for novel approaches to eliminate mCRPC is compelling; a promising option is replication-selective (oncolytic) adenoviruses with demonstrated efficacy in preclinical models of multidrug-resistant PCa. The safety of various viral mutants has been confirmed in numerous clinical trials with minimal toxicity in patients. Importantly, oncolytic adenoviruses synergise with the current standard of care for mCRPC even in treatment-resistant cells. In early phase I–II clinical trials, promising efficacy in patients with localised PCa was reported after intratumoural administration, and phase III trials are underway. To enable systemic delivery, for targeting of mCRPC, further developments are necessary because of the short half-life of the adenoviral mutants in human blood. Current progress in preventing the high-affinity binding of adenovirus to erythrocytes, hepatocyte uptake, and elimination by hepatic Kupffer cells will be described

Targeting Triple Negative Breast Cancer With Oncolytic Adenoviruses

Breast cancer (BC) is the most common cancer globally, accounting for 685,000 deaths in 2020. Triple-negative breast cancers (TNBC) lack oestrogen (ER) and progesterone (PR) hormone receptor expression and HER2 overexpression. TNBC represent 10–15% of all BC with high incidence in women under 50-years old that have BRCA mutations, and have a dismal prognosis. African American and Hispanic women are at higher risk partly due to the common occurrence of BRCA mutations. The standard treatment for TNBC includes surgery, radiotherapy, and chemotherapy although, resistance to all standard-of-care therapies eventually develops. It is crucial to identify and develop more efficacious therapeutics with different mechanisms of action to improve on survival in these women. Recent findings with oncolytic adenoviruses (OAds) may generate a new strategy to improve on the outcomes for women afflicted by TNBC and other types of BC. OAds are genetically engineered to selectively lyse, eliminate and recruit the host antitumour immune responses, leaving normal cells unharmed. The most common modifications are deletions in the early gene products including the E1B55 KDa protein, specific regions of the E1A protein, or insertion of tumour-specific promoters. Clinical trials using OAds for various adenocarcinomas have not yet been sufficiently evaluated in BC patients. Preclinical studies demonstrated efficacy in BC cell lines, including TNBC cells, with promising novel adenoviral mutants. Here we review the results reported for the most promising OAds in preclinical studies and clinical trials administered alone and in combination with current standard of care or with novel therapeutics. Combinations of OAds with small molecule drugs targeting the epidermal growth factor receptor (EGFR), androgen receptor (AR), and DNA damage repair by the novel PARP inhibitors are currently under investigation with reported enhanced efficacy. The combination of the PARP-inhibitor Olaparib with OAds showed an impressive anti-tumour effect. The most promising findings to date are with OAds in combination with antibodies towards the immune checkpoints or expression of cytokines from the viral backbone. Although safety and efficacy have been demonstrated in numerous clinical trials and preclinical studies with cancer-selective OAds, further developments are needed to eliminate metastatic lesions, increase immune activation and intratumoural viral spread. We discuss shortcomings of the OAds and potential solutions for improving on patient outcomes

Adenovirus-Mediated Sensitization to the Cytotoxic Drugs Docetaxel and Mitoxantrone Is Dependent on Regulatory Domains in the E1ACR1 Gene-Region

Oncolytic adenoviruses have shown promising efficacy in clinical trials targeting prostate cancers that frequently develop resistance to all current therapies. The replication-selective mutants AdΔΔ and dl922–947, defective in pRb-binding, have been demonstrated to synergise with the current standard of care, mitoxantrone and docetaxel, in prostate cancer models. While expression of the early viral E1A gene is essential for the enhanced cell killing, the specific E1A-regions required for the effects are unknown. Here, we demonstrate that replicating mutants deleted in small E1A-domains, binding pRb (dl1108), p300/CBP (dl1104) and p400/TRRAP or p21 (dl1102) sensitize human prostate cancer cells (PC-3, DU145, 22Rv1) to mitoxantrone and docetaxel. Through generation of non-replicating mutants, we demonstrate that the small E1A12S protein is sufficient to potently sensitize all prostate cancer cells to the drugs even in the absence of viral replication and the E1A transactivating domain, conserved region (CR) 3. Furthermore, the p300/CBP-binding domain in E1ACR1 is essential for drug-sensitisation in the absence (AdE1A1104) but not in the presence of the E1ACR3 (dl1104) domain. AdE1A1104 also failed to increase apoptosis and accumulation of cells in G2/M. All E1AΔCR2 mutants (AdE1A1108, dl922–947) and AdE1A1102 or dl1102 enhance cell killing to the same degree as wild type virus. In PC-3 xenografts in vivo the dl1102 mutant significantly prolongs time to tumor progression that is further enhanced in combination with docetaxel. Neither dl1102 nor dl1104 replicates in normal human epithelial cells (NHBE). These findings suggest that additional E1A-deletions might be included when developing more potent replication-selective oncolytic viruses, such as the AdΔCR2-mutants, to further enhance potency through synergistic cell killing in combination with current chemotherapeutics

Designer Oncolytic Adenovirus: Coming of Age

The licensing of talimogene laherparepvec (T-Vec) represented a landmark moment for oncolytic virotherapy, since it provided unequivocal evidence for the long-touted potential of genetically modified replicating viruses as anti-cancer agents. Whilst T-Vec is promising as a locally delivered virotherapy, especially in combination with immune-checkpoint inhibitors, the quest continues for a virus capable of specific tumour cell killing via systemic administration. One candidate is oncolytic adenovirus (Ad); it’s double stranded DNA genome is easily manipulated and a wide range of strategies and technologies have been employed to empower the vector with improved pharmacokinetics and tumour targeting ability. As well characterised clinical and experimental agents, we have detailed knowledge of adenoviruses’ mechanisms of pathogenicity, supported by detailed virological studies and in vivo interactions. In this review we highlight the strides made in the engineering of bespoke adenoviral vectors to specifically infect, replicate within, and destroy tumour cells. We discuss how mutations in genes regulating adenoviral replication after cell entry can be used to restrict replication to the tumour, and summarise how detailed knowledge of viral capsid interactions enable rational modification to eliminate native tropisms, and simultaneously promote active uptake by cancerous tissues. We argue that these designer-viruses, exploiting the viruses natural mechanisms and regulated at every level of replication, represent the ideal platforms for local overexpression of therapeutic transgenes such as immunomodulatory agents. Where T-Vec has paved the way, Ad-based vectors now follow. The era of designer oncolytic virotherapies looks decidedly as though it will soon become a reality

Försurning och kalkning i Jönköpings län. Verksamhetsberättelse 2011

Klimatet påverkar i hög grad miljön i våra vatten. Mer regn ger högre flöden och utflödet av försurande ämnen ökar från omgivande marker. Under 2011 var nederbörden 20 % högre och temperaturen 1,5 °C över det normala. De största högflödena inföll under april och december. Nedfallet av svavel var något högre än under de tre senaste åren men under nivån för vad som är långsiktigt hållbart. För nedfall av kväve och för pH i markvattnet märks ännu inga förbättringar. Under 2011 spreds 11 300 ton kalk i länet vilket är 34 % lägre än snittet för 1997- 99. Drygt hälften av kalken spreds på våtmarker. Prishöjningen var i genomsnitt 12 %. Nio av totalt tio kalkande kommuner reviderade sina kalkmängder. Den vattenkemiska måluppfyllelsen har undersökts på 350 lokaler i länet. Målet var uppfyllt i 82 % av vattendragens längd och 99 % av den sjöyta som undersökts. Måluppfyllelsen för den biologiska effektuppföljningen var uppnådd i 86 % av vattendragens längd och 87 % av undersökt sjöyta. Under 2011 har totalt 33 bottenfaunalokaler, 1 mussellokal, 15 kräftlokaler, 66 elfiskelokaler och 14 nätprovfiskesjöar undersökts. Arbetet med biologisk återställning görs för att de arter som försvunnit eller minskat i antal på grund av försurning ska kunna återkomma. Målvattendragsinventeringen påbörjades hösten 2010 och omfattar totalt 146 målvattendragssträckor i länet. Syftet är att beskriva försurningsläget och ge underlag för framtida kalkningsplanering. Länsstyrelsen i Jönköpings län har under 2011 varit med och utvecklat Nationella Kalkdatabasen. Informationsmaterial om försurning och kalkning – ”När surt regn faller” har tagits fram och är avsedda för högstadie- och gymnasieskolor.Regionala inventeringsrapporter import från MDP 2015-05</p

HDAC Inhibitors Enhance Efficacy of the Oncolytic Adenoviruses Ad&#8710;&#8710; and Ad-3&#8710;-A20T in Pancreatic and Triple-Negative Breast Cancer Models

The prognosis for triple-negative breast cancer (TNBC) and pancreatic ductal adenocarcinoma (PDAC) is dismal. TNBC and PDAC are highly aggressive cancers with few treatment options and a potential for rapid resistance to standard-of-care chemotherapeutics. Oncolytic adenoviruses (OAds) represent a promising tumour-selective strategy that can overcome treatment resistance and eliminate cancer cells by lysis and host immune activation. We demonstrate that histone deacetylase inhibitors (HDACi) potently enhanced the cancer-cell killing of our OAds, Ad&#8710;&#8710; and Ad-3&#8710;-A20T in TNBC and PDAC preclinical models. In the TNBC cell lines MDA-MB-436, SUM159 and CAL51, cell killing, viral uptake and replication were increased when treated with sublethal doses of the Class-I-selective HDACis Scriptaid, Romidepsin and MS-275. The pan-HDACi, TSA efficiently improved OAd efficacy, both in vitro and in SUM159 xenograft models in vivo. Cell killing and Ad&#8710;&#8710; replication was also significantly increased in five PDAC cell lines when pre-treated with TSA. Efficacy was dependent on treatment time and dose, and on the specific genetic alterations in each cell line. Expression of the cancer specific &alpha;v&szlig;6-integrin supported higher viral uptake of the integrin-retargeted Ad-3&#8710;-A20T in combination with Scriptaid. In conclusion, we demonstrate that inhibition of specific HDACs is a potential means to enhance OAd activity, supporting clinical translation

Complexing the Oncolytic Adenoviruses Ad&#8710;&#8710; and Ad-3&#8710;-A20T with Cationic Nanoparticles Enhances Viral Infection and Spread in Prostate and Pancreatic Cancer Models

Oncolytic adenoviruses (OAd) can be employed to efficiently eliminate cancer cells through multiple mechanisms of action including cell lysis and immune activation. Our OAds, Ad&Delta;&Delta; and Ad-3&#8710;-A20T, selectively infect, replicate in, and kill adenocarcinoma cells with the added benefit of re-sensitising drug-resistant cells in preclinical models. Further modifications are required to enable systemic delivery in patients due to the rapid hepatic elimination and neutralisation by blood factors and antibodies. Here, we show data that support the use of coating OAds with gold nanoparticles (AuNPs) as a possible new method of virus modification to help augment tumour uptake. The pre-incubation of cationic AuNPs with Ad&Delta;&Delta;, Ad-3&#8710;-A20T and wild type adenovirus (Ad5wt) was performed prior to infection of prostate/pancreatic cancer cell lines (22Rv, PC3, Panc04.03, PT45) and a pancreatic stellate cell line (PS1). Levels of viral infection, replication and cell viability were quantified 24&ndash;72 h post-infection in the presence and absence of AuNPs. Viral spread was assessed in organotypic cultures. The presence of AuNPs significantly increased the uptake of Ad&#8710;&#8710;, Ad-3&#8710;-A20T and Ad5wt in all the cell lines tested (ranging from 1.5-fold to 40-fold), compared to virus alone, with the greatest uptake observed in PS1, a usually adenovirus-resistant cell line. Pre-coating the Ad&Delta;&Delta; and Ad-3&#8710;-A20T with AuNPs also increased viral replication, leading to enhanced cell killing, with maximal effect in the most virus-insensitive cells (from 1.4-fold to 5-fold). To conclude, the electrostatic association of virus with cationic agents provides a new avenue to increase the dose in tumour lesions and potentially protect the virus from detrimental blood factor binding. Such an approach warrants further investigation for clinical translation