Dr Guy Simpson

We have examined the human mammary tumor cell line T47D and have found that these cells produce virus-like particles which band at the typical density for retroviral particles on a sucrose gradient, possess reverse transcriptase activity, and package HERV-K10-like sequences. Using this information and a bacterial expression system to identify long open reading frames, we have identified individual clones which have full-length open reading frames for reverse transcriptase and RNase H and which could encode the reverse transcriptase activity detected in these cells.

The initial step in the infection cycle of human immunodeficiency virus type 1 (HIV-1) involves binding of its surface glycoprotein gpl20 to the T lymphocyte CD4 antigen. CPF-DD is a low molecular weight inhibitor of HIV infectivity that inhibits gpl 20 binding to CD4 in vitro (Finberg et al, Science 249, 287–291, 1990). We find, however, that the actions of CPF-DD are not limited to its ability to interfere with gpl20-CD4 binding; its predominant action is to remove the viral envelope from the underlying core. Subsequently the virions disintegrate. Most enveloped viruses tested were inhibited by CPF-DD, but the infectivity of noneveloped viruses was unaffected or only slightly reduced.

A newly identified herpesvirus has been associated with Kaposi's sarcoma. We determined risk factors for Kaposi's‐sarcoma‐associated herpesvirus/human herpesvirus 8 (KSHV/HHV‐8) seropositivity and incidence of infection over time in a cohort of Danish homosexual men followed from 1981 to 1996. Antibodies to a latent nuclear (LANA) and a structural (orf65) antigen of KSHV/HHV‐8 were measured by immunofluorescence and ELISA/WB respectively. Through linkage with the national AIDS registry, all cohort members diagnosed with AIDS as of September 1996 were identified and their hospital records were scrutinized to record all diagnoses of KS. Overall, 21.1% (52/246) of the men were KSHV/HHV‐8‐seropositive in 1981. Among the initially seronegative, the rate of KSHV/HHV‐8 seroconversion was highest between 1981 and 1982 and declined steadily thereafter. In a multivariate analysis of the status at enrollment in 1981, KSHV/HHV‐8 seropositivity was not associated with age but was independently associated both with number of receptive anal intercourses (OR = 2.83; p = 0.03) and with sex with US men (OR = 2.27; p < 0.05). In a multivariate analysis of follow‐up data, risk of KSHV/HHV‐8 seroconversion was independently associated with having visited homosexual communities in the United States, and current HIV‐positive status. More than 5 years' homosexual experience was associated with an insignificantly increased risk (RR = 2.68). KS occurred only in HIV‐positive men who were KSHV/HHV‐8‐positive at or prior to their KS diagnosis. In conclusion, KSHV/HHV‐8 appears to be sexually transmitted, probably by receptive anal intercourse, and may have been introduced to Danish homosexual men via sex with US men. The epidemic of KSHV/HHV‐8 is now declining. These findings are concordant with the view that KSHV/HHV‐8 may have been actively spread simultaneously with and by the same activities that lead to the spread of HIV. Int. J. Cancer 77:543–548, 1998. © 1998 Wiley‐Liss, Inc.

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8, may be the infectious cause of KS. Its prevalence in the general population, on the basis of detection of the virus genome, is controversial. To investigate the seroprevalence, we measured antibodies to a recombinant capsid-related (lytic cycle) KSHV antigen and a latent antigen complex. We selected potentially immunoreactive capsidrelated proteins of KSHV by expressing them as recombinant proteins and testing them in western blot assays. We used a truncated recombinant protein encoded by KSHV open reading frame 65 (orf 65) to develop a diagnostic enzyme-linked immunosorbent assay (ELISA) and tested sera from HIV-infected individuals with KS, HIV-uninfected patients with “classic” KS, other HIV risk groups, and blood donors. We also compared the antibody response to this capsid-related protein to the response to latent antigen(s) in an immunofluorescence assay. 77/92 (84%) sera from KS patients reacted with the KSHV orf 65 protein and 84/103 (81·5%) reacted with KSHV latent antigen(s). The dominant immunogenic region of orf 65 is within the carboxyterminal 80 aminoacids, a region with little sequence similarity to the related Epstein-Barr virus, suggesting that orf 65 is a KSHV specific antigen. Only three sera from patients with haemophilia (1/84) or from intravenous drug users (2/63) had KSHV specific antibodies in the orf 65 assay whereas none of these sera reacted with latent antigen. Antibodies to KSHV were also infrequently found in UK and US blood donors by either assay (UK, 3/174 with orf 65 and 4/150 with latent antigen; US, 6/117 with orf 65 and 0/117 with latent antigen). They were more common among HIV-infected gay men without KS (5/16 by orf 65 ELISA, 10/33 by IFA), HIV-uninfected STD clinic attenders (14/166 by IFA), and Ugandan HIV-uninfected controls (6/17 by orf 65 ELISA, 9/17 by IFA). Antibody reactivity to the orf 65 protein (ELISA) and to latent antigen(s) (IFA) was concordant in 89% of 462 sera tested but reactive blood donor sera were discordant in both assays. Four AIDS-KS sera were unreactive in both assays. The distribution of antibodies to both a capsid-related recombinant protein and latent antigen(s) of KSHV strongly supports the view that infection with this virus is largely confined to individuals with, or at increased risk for, KS. However, infection with KSHV does occur, rarely, in the general UK and US population and is more common in Uganda. Antibodies to latent antigen(s) or to orf 65 encoded capsid protein will not detect all cases of KSHV infection, and a combination of several antigens will probably be required for accurate screening and confirmatory assays.

Engrailed-2 (EN2) is a homeodomain-containing transcription factor that has roles in boundary formation and neural guidance in early development, but which is also expressed in a range of cancers. In addition to transcriptional regulation, it is secreted by cells and taken up by others through a mechanism that is yet to be fully elucidated. In this study, the distribution of EN2 protein in cells was evaluated using immunofluorescence with a set of antibodies raised against overlapping epitopes across the protein, and through the use of an EN2-GFP construct. MX2 expression in primary prostate tumors was evaluated using immunohistochemistry. We showed that EN2 protein is present in the cell membrane and within microvesicles that can be secreted from the cell and taken up by others. When taken up by normal cells from the stroma EN2 induces the expression of MX2 (MxB), a protein that has a key role in the innate immune response to viruses. Our findings indicate that EN2 secretion by tumors may be a means of preventing viral-mediated immune invasion of tissue immediately adjacent to the tumor.

The HOX genes encode a family of transcription factors that have key roles in both development and malignancy. Disrupting the interaction between HOX proteins and their binding partner, PBX, has been shown to cause apoptotic cell death in a range of solid tumors. However, despite HOX proteins playing a particularly significant role in acute myeloid leukemia (AML), the relationship between HOX gene expression and patient survival has not been evaluated (with the exception of HOXA9), and the mechanism by which HOX/PBX inhibition induces cell death in this malignancy is not well understood. In this study, we show that the expression of HOXA5, HOXB2, HOXB4, HOXB9, and HOXC9, but not HOXA9, in primary AML samples is significantly related to survival. Furthermore, the previously described inhibitor of HOX/PBX dimerization, HXR9, is cytotoxic to both AML-derived cell lines and primary AML cells from patients. The mechanism of cell death is not dependent on apoptosis but instead involves a regulated form of necrosis referred to as necroptosis. HXR9-induced necroptosis is enhanced by inhibitors of protein kinase C (PKC) signaling, and HXR9 combined with the PKC inhibitor Ro31 causes a significantly greater reduction in tumor growth compared to either reagent alone.

To study the seroprevalence of Kaposi's sarcoma-associated herpesvirus/human herpesvirus type 8 (KSHV/HHV-8) in 779 Italian blood donors. Sera were tested for antibodies to a latency-associated nuclear antigen (LANA) and a capsid related protein encoded by ORF65. Among all Italian donors, 17.7% and 18.7% had antibodies to LANA and ORF65 protein, respectively, and 24.1% had antibodies to at least one antigen. KSHV/HHV-8 seroprevalence was higher in the Po valley and in Sardinia than close to the sub-Alpine Veneto region, Tuscany, or Apulia. KSHV/HHV-8 seroprevalence was almost equally distributed between men and women but increased in the older age groups. The regional differences and age distribution in seroprevalence agree partially with the incidence of classic KS in Italy. The rarity of classic KS in KSHV/HHV-8-infected subjects and the equal gender distribution of seroprevalence suggest that other cofactors may contribute to KS development in human immunodeficiency virus type 1 (HIV-1)-uninfected individuals.

All primates studied to date produce retroviral-like particles in their placentae. We have purified these particles from two primate species, one Old World (human) and one New World (marmoset), and have identified the retroviral sequences which are packaged into these particles. Three families of sequences have been detected in these particles in human, all of which have the highest homology to B- and D-type retroviruses and to the human endogenous retrovirus HERV-K10. Previous studies have reported that the New World monkeys do not possess sequences with homology to HERV-K10. We have identified a new family of low-copy-number sequences which are present in New World monkeys and which possess 70% homology to the HERV-K family. Particles from both species possess reverse transcriptase activity and we have found that some of these retroviral particles package sequences which encode long open reading frames inpol,as revealed by expression cloning inEscherichia coli.These open reading frames could encode the reverse transcriptase enzyme activity found in the particles.

We have isolated a new foamy virus from blood samples taken from two apparently healthy orangutans (Pongo pygmaeus). The older orangutan has since died with encephalopathy after a brief acute illness, while the younger one, his grandson, remains well. These animals and 12 other orangutans had specific antibodies to foamy virus as measured by immunofluorescence. The new foamy virus and the antisera showed strong and specific neutralization, with only weak cross-reaction with other simian foamy virus strains. Southern blotting with gag and env probes of human foamy virus and PCR amplification showed that the new foamy virus, designated SFV-11, is related to, yet distinct from, previously characterized strains from humans, chimpanzees, and monkeys.

LANA, the major latency-associated nuclear antigen of Kaposi's sarcoma herpesvirus/human herpesvirus-8 (KSHV/HHV-8), binds RING3 protein, one of five human homologues of the fsh (female sterile homeotic) gene product of Drosophila. In KSHV/HHV-8-infected cells LANA and the viral episomes accumulate in heterochromatin-associated nuclear bodies. Here we show that in several KSHV/HHV-8-negative cell lines derived from carcinomas, sarcomas and lymphomas, RING3 was expressed at low levels, primarily localized to the euchromatin, and dissociated from the chromosomes during mitosis. In contrast, in KSHV/HHV-8-infected body cavity lymphoma cells the bulk of RING3 localizes to the LANA nuclear bodies and remains associated with the chromosomes during cell division. KSHV/HHV-8-infected body cavity lymphoma cells expressed RING3 at much higher levels than cells without the virus. Transfection of full-length LANA, but not the C terminus alone, greatly induced RING3 gene expression, and LANA and RING3 co-localized even in the transfected cells, in the absence of KSHV/HHV-8 viral DNA. High levels of LANA expression led to the disappearance of heterochromatin in both human and mouse cells. We suggest that LANA and RING3 may create a local euchromatic microenvironment around the viral episomes that are anchored to the heterochromatin.

Human HOS cells containing a Moloney murine leukemia virus (Mo-MLV) recombinant genome were infected by a panel of retroviruses. The C-type viruses simian sarcoma associated virus, feline leukemia virus subgroup B, and the feline endogenous virus RD114 were able to form pseudotypes with the Mo-MLV genome, which transferred a selectable marker gene to target cells; however, Human T cell leukemia virus-1 and the D-type viruses Mason-Pfizer monkey virus and simian retrovirus-1 failed to rescue the Mo-MLV vector. Further characterization of the RD114 pseudotype demonstrated that it retained the receptor specificity of RD114 and will therefore prove useful in receptor characterization.

Specific point mutations which affect viral tropism have been identified in both the V3 loop and in the CD4-binding region of the human immunodeficiency virus type 1 surface glycoprotein gp120. Here we report that a single point mutation in the first variable region (V1) of human immunodeficiency virus type 1 strain JRCSF is responsible for a change in viral tropism.

Kaposi’s sarcoma-associated herpesvirus (KSHV/HHV-8) is the likely infectious cause of Kaposi’s sarcoma, primary effusion lymphoma, and some cases of multicentric Castleman’s disease. Its latent nuclear antigen (LANA) is expressed in the nuclei of latently infected cells and may play a role in the persistence of episomal viral DNA in dividing cells. Here we report that LANA interacts with RING3, a nuclear protein and member of the Drosophila fsh (female sterile homeotic) family of proteins, some of which have previously been implicated in controlling gene expression. Binding of RING3 to LANA involves the ET domain, characteristic of fsh-related proteins, suggesting that this highly conserved region is involved in protein-protein interactions. The interaction between RING3 and LANA results in phosphorylation of serine and threonine residues located between amino acids 951 and 1107 in the carboxy-terminal region of LANA. However, RING3 is not itself a kinase but appears to recruit an as yet unidentified serine/threonine protein kinase into the complex which it forms with LANA.

Kaposi's sarcoma (KS)-associated herpesvirus or human herpesvirus 8 (KSHV/HHV8) is the likely cause of KS and primary effusion lymphomas or body cavity-based lymphomas (BCBLs). A latency-associated nuclear immunofluorescence antigen (LANA) (D. H. Kedes, E. Operskalski, M. Busch, R. Kohn, J. Flood, and D. Ganem, Nat. Med. 2:918-924, 1996; S. J. Gao, L. Kingsley, M. Li, W. Zheng, C. Parravicini, J. Ziegler, R. Newton, C. R. Rinaldo, A. Saah, J. Phair, R. Detels, Y. Chang, and P. S. Moore, Nat. Med. 2:925-928, 1996) and a 222- to 234-kDa nuclear protein (LNA) (S. J. Gao, L. Kingsley, D. R. Hoover, T. J. Spira, C. R. Rinaldo, A. Saah, J. Phair, R. Detels, P. Parry, Y. Chang, and P. S. Moore, N. Engl. J. Med. 335:233-241, 1996) have previously been described in BCBL cell lines by immunofluorescence and Western blotting techniques, respectively. To identify the viral gene(s) encoding this antigen(s) we screened a cDNA library from HBL-6 cells, a B-cell lymphoma cell line persistently infected with KSHV/HHV8, with KS patient sera. One set of positive clones contained the 3' end of orf73, as well as the complete orf72 and orfK13, and another set contained the 5' end of orf73. Comparison of cDNA sequences with the KSHV/HHV8 genomic sequence revealed a splice event, occurring upstream of orf73. Immunoaffinity purified antibodies to a recombinant carboxy-terminal fragment of the orf73-encoded protein showed the characteristic speckled nuclear immunofluorescence pattern of LANA and reacted with the 222- to 234-kDa LNA on Western blots. Expression of full-length orf73 in bacteria and COS7 cells reproduced the LNA banding pattern. Immunohistochemistry on cases of nodular KS revealed that orf73/LNA is expressed in the nucleus of KS spindle cells. These findings demonstrate that orf73 encodes the 222- to 234-kDa LNA, is a component of LANA, and is expressed in KS tumor cells.

Background: The finding of antibodies against human herpesvirus 8 (HHV-8) is associated with the occurrence of Kaposi's sarcoma in persons infected with HIV. However, the predictive value of HHV-8 antibodies for Kaposi's sarcoma in HIV infection is unknown. Methods: The Amsterdam Cohort Studies on HIV infection and AIDS started in 1984 for homosexual men and in 1985 for injecting drug users. Serum samples from 1459 homosexual men and 1167 drug users were tested for antibodies to recombinant HHV-8 lytic-phase capsid (ORF65) antigen and latent-phase nuclear (ORF73) antigen. Individuals were retrospectively identified as HHV-8-positive or HHV-8-negative at enrolment or HHV-8 seroconverter during the study. Kaposi's sarcoma-free survival time was compared between HIV-infected men who were positive for HHV-8 at enrolment and those who later seroconverted for HHV-8. Hazard ratios were estimated for Kaposi's sarcoma, lymphoma, and opportunistic infection according to the HHV-8 serostatus. Results: The incidence of HHV-8 seroconversion among drugs users was 0.7 per 100 person-years based on 31 seroconversions, whereas an incidence of 3.6 was found among homosexual men based on 215 seroconversions. The hazard ratio for Kaposi's sarcoma was 3.15 (95% CI: 1.89-5.25) in HIV-infected individuals if HHV-8 antibodies were present either at enrolment or at HIV seroconversion. In HIV-infected persons who later seroconverted to HHV-8, Kaposi's sarcoma developed more rapidly: hazard ratio of 5.04 (95% CI: 2.94-8.64), an additional risk of 1.60 (95% CI: 1.01-2.53; P = 0.04). Time-dependent adjustment for CD4 super(+) cell count and HIV RNA had no impact on the additional risk, although the CD4 super(+) cell count was an independent risk factor for Kaposi's sarcoma. HHV-8 infection did not increase the risk of AIDS-related lymphoma or opportunistic infections. Conclusions: The incidence of HHV-8 infection is higher in homosexual men than in drug users. The presence of HHV-8 antibodies in HIV-infected persons increases the risk of Kaposi's sarcoma. Among HIV-infected persons, those who subsequently seroconvert for HHV-8 are at highest risk. These results strongly confirm the causal role of HHV-8 in Kaposi's sarcoma and emphasize the clinical relevance of HHV-8 seroconversion before and after the HIV infection.

Pseudotypes of gibbon ape leukemia virus/simian sarcoma-associated virus (GALV/SSAV) and feline leukemia virus subgroup B (FeLV-B) have been constructed by rescuing a Moloney murine leukemia virus vector genome with wild-type GALV/SSAV or FeLV-B. The resulting recombinant viruses utilized core and envelope proteins from the wild-type virus and conferred resistance to growth in L-histidinol upon infected cells by virtue of the HisD gene encoded by the vector genome. They displayed the host range specificity of the rescuing viruses and could be neutralized by virus-specific antisera. Receptor cross-interference was observed when the GALV/SSAV or FeLV-B pseudotypes were used to superinfect cells productively infected with either GALV/SSAV or FeLV-B. Although murine cells are resistant to FeLV-B infection, murine cells expressing the human gene for the GALV/SSAV receptor became susceptible to FeLV-B infection. Therefore GALV/SSAV and FeLV-B utilize the same cell surface receptor.

Purpose: The CANON (CAVATAK in NON-muscle invasive bladder cancer) study evaluated a novel ICAM-1-targeted immunotherapeutic-coxsackievirus A21 as a novel oncolytic agent against bladder cancer. Experimental Design: Fifteen patients enrolled on this 'window of opportunity' phase 1 study, exposing primary bladder cancers to CAVATAK prior to surgery. The first nine patients received intravesical administration of monotherapy CAVATAK; in the second stage, six patients received CAVATAK with a sub-therapeutic dose of mitomycinC, known to enhance expression of ICAM-1 on bladder cancer cells. The primary endpoint was to determine patient safety and maximum tolerated dose. Secondary endpoints were evidence of viral replication, induction of inflammatory cytokines, anti-tumour activity and viral-induced changes in resected tissue. Results: Clinical activity of CAVATAK was demonstrated by induction of tumour inflammation and haemorrhage following either single or multiple administrations of CAVATAK in multiple patients, and a complete resolution of tumour in one patient. Whether used alone or in combination with mitomycinC, CAVATAK caused marked inflammatory changes within NMIBC tissue biopsies by up-regulating interferon-inducible genes including both immune checkpoint-inhibitory genes (PD-L1 and LAG3) and Th1-associated chemokines as well as induction of the innate activator RIG-I, compared to bladder cancer tissue from untreated patients. No significant toxicities were reported in any patient, from either virus or combination therapy. Conclusions: The acceptable safety profile of CAVATAK, proof of viral targeting, replication and tumour cell death together with the virus-mediated increases in "immunological heat" within the tumour microenvironment all indicate that CAVATAK may be potentially considered as a novel therapeutic for NMIBC.

This fully updated volume explores recently improved avenues to study urothelial carcinomas. Beginning with several novel chapters on molecular characterization and urothelial carcinogenesis, the book continues with sections on cellular and animal models, biomarkers, and approaches for targeted therapy. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step and readily reproducible laboratory protocols, as well as tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Urothelial Carcinoma: Methods and Protocols, Second Edition serves as a valuable resource to further increase our knowledge on urothelial carcinoma and also to aid research on numerous other cancers.

Oncolytic viruses are multifunctional anticancer agents with huge clinical potential, and have recently passed the randomized Phase III clinical trial hurdle. Both wild-type and engineered viruses have been selected for targeting of specific cancers, to elicit cytotoxicity, and also to generate antitumor immunity. Single-agent oncolytic virotherapy treatments have resulted in modest effects in the clinic. There is increasing interest in their combination with cytotoxic agents, radiotherapy and immune-checkpoint inhibitors. Similarly to oncolytic viruses, the benefits of chemotherapeutic agents may be that they induce systemic antitumor immunity through the induction of immunogenic cell death of cancer cells. Combining these two treatment modalities has to date resulted in significant potential in vitro and in vivo synergies through various mechanisms without any apparent additional toxicities. Chemotherapy has been and will continue to be integral to the management of advanced cancers. This review therefore focuses on the potential for a number of common cytotoxic agents to be combined with clinically relevant oncolytic viruses. In many cases, this combined approach has already advanced to the clinical trial arena.

There are currently numerous oncolytic viruses undergoing clinical trial evaluation in cancer patients and one agent,Talimogene laherparepvec, has been approved for the treatment of malignant melanoma. This progress highlights the huge clinical potential of this treatment modality, and the focus is now combining these agents with conventional anti-cancer treatments or agents that enhance viral replication, and thereby oncolysis, in the tumour microenvironment. We evaluated the combination of reovirus with rapamycin in B16F10 cell, a murine model of malignant melanoma, based on potential mechanisms by which mTOR inhibitors might enhance viral oncolysis. Rapamycin was not immunomodulatory in that it had no effect on the generation of an anti-reovirus neutralising antibody response in C57/black 6 mice. The cell cycle effects of reovirus (increase G0/G1 fraction) were unaffected by concomitant or sequential exposure of rapamycin, However, rapamycin attenuated viral replication if given prior or concomitantly with reovirus and similarly reduced reovirus-induced apoptotic cell death annexin V/PI and caspase 3/7 activation studies. We found clear evidence of synergistic antitumour effects of the combination both in vitro and in vivo, which was sequence dependent only in the in vitro setting. In conclusion, we have demonstrated synergistic anti-tumour efficacy of reovirus and rapamycin combination.

A large number of oncolytic viral vectors are currently under clinical development for cancer therapy. Herpes simplex virus type 1 (HSV-1) has demonstrated particular promise in this field, showing genetically engineered selective tumor replication and cytotoxicity in a wide variety of tumor types, without damaging healthy tissues. Enhanced activity has been observed when a range of therapeutic genes has been inserted into various oncolytic HSV genomes. Here, we discuss methods used to develop and characterize an oncolytic HSV virus that combines expression of a highly potent prodrug activating gene (yeast cytosine deaminase/uracil phosphoribosyltransferase fusion [Fcy::Fur]) and the fusogenic glycoprotein from gibbon ape leukemia virus (GALV) for enhanced local tumor control.

The HOX genes are a family of closely related transcription factors that help to define the identity of cells and tissues during embryonic development and which are also frequently deregulated in a number of malignancies, including breast cancer. While relatively little is known about the roles that individual HOX genes play in cancer, it is however clear that these roles can be both contradictory, with some members acting as oncogenes and some as tumor suppressors, and also redundant, with several genes essentially having the same function. Here, we have attempted to address this complexity using the HXR9 peptide to target the interaction between HOX proteins and PBX, a second transcription factor that serves as a common co-factor for many HOX proteins. We show that HXR9 causes apoptosis in a number of breast cancer-derived cell lines and that sensitivity to HXR9 is directly related to the averaged expression of HOX genes HOXB1 through to HOXB9, providing a potential biomarker to predict the sensitivity of breast tumors to HXR9 or its derivatives. Measuring the expression of HOX genes HOXB1-HOXB9 in primary tumors revealed that a subset of tumors show highly elevated expression indicating that these might be potentially very sensitive to killing by HXR9. Furthermore, we show that while HXR9 blocks the oncogenic activity of HOX genes, it does not affect the known tumor-suppressor properties of a subset of HOX genes in breast cancer.

Prostate cancers are considered “cold” tumors characterized by minimal T cell infiltrates, absence of a type I interferon (IFN) signature, and the presence of immunosuppressive cells. This non-inflamed phenotype is likely responsible for the lack of sensitivity of prostate cancer patients to immune checkpoint blockade (ICB) therapy. Oncolytic virus therapy can potentially overcome this resistance to immunotherapy in prostate cancers by transforming cold tumors into “hot,” immune cell-infiltrated tumors. We investigated whether the combination of intratumoral oncolytic reovirus, followed by targeted blockade of Programmed cell death protein 1 (PD-1) checkpoint inhibition and/or the immunomodulatory CD73/Adenosine system can enhance anti-tumor immunity. Treatment of subcutaneous TRAMP-C2 prostate tumors with combined intratumoral reovirus and anti-PD-1 or anti-CD73 antibody significantly enhanced survival of mice compared with reovirus or either antibody therapy alone. Only combination therapy led to rejection of pre-established tumors and protection from tumor re-challenge. This therapeutic effect was dependent on CD4 + T cells and natural killer (NK) cells. NanoString immune profiling of tumors confirmed that reovirus increased tumor immune cell infiltration and revealed an upregulation of the immune-regulatory receptor, B- and T-lymphocyte attenuator (BTLA). This expression of BTLA on innate antigen-presenting cells (APCs) and its ligand, Herpesvirus entry mediator (HVEM), on T cells from reovirus-infected tumors was in keeping with a role for the HVEM-BTLA pathway in promoting the potent anti-tumor memory response observed. Immunotherapy in prostate cancer is limited because of a lack of immune cells within the tumor. Annels et al. used oncolytic viruses to recruit immune cells into the tumor and showed that in combination with checkpoint inhibitors, which take the brake off of the immune system, established tumors were rejected.

Purpose. Nonmuscle invasive bladder cancer (BCa) has a high recurrence rate requiring lifelong surveillance. Urinary biomarkers are promising as simple alternatives to cystoscopy for the diagnosis of recurrent bladder cancer. However, no single marker can achieve the required accuracy. The purpose of this study was to select a multiparameter panel, comprising urinary biomarkers and clinical parameters, for BCa recurrence diagnosis. Experimental Design. Candidate biomarkers were measured in urine samples of BCa patients with recurrence and BCa patients without recurrence. A multiplatform strategy was used for marker quantification comprising a multiplexed microarray and an automated platform for ELISA analysis. A multivariate statistical analysis combined the results from both platforms with the collected clinical data. Results. The best performing combination of biomarkers and clinical parameters achieved an AUC value of 0.91, showing better performance than individual parameters. This panel comprises six biomarkers (cadherin-1, IL-8, ErbB2, IL-6, EN2, and VEGF-A) and three clinical parameters (number of past recurrences, number of BCG therapies, and stage at time of diagnosis). Conclusions. The multiparameter panel could be a useful noninvasive tool for BCa surveillance and potentially impact the clinical management of this disease. Validation of results in an independent cohort is warranted.

Glioblastoma multiforme (GBM) is the most common high-grade malignant brain tumour in adults and arises from the glial cells in the brain. The prognosis of treated GBM remains very poor with 5-year survival rates of 5%, a figure which has not improved over the last few decades. Currently, there is a modest 14-month overall median survival in patients undergoing maximum safe resection plus adjuvant chemoradiotherapy. HOX gene dysregulation is now a widely recognised feature of many malignancies. In this study we have focused on HOX gene dysregulation in GBM as a potential therapeutic target in a disease with high unmet need. We show significant dysregulation of these developmentally crucial genes and specifically that HOX genes A9, A10, C4 and D9 are strong candidates for biomarkers and treatment targets for GBM and GBM cancer stem cells. We evaluated a next generation therapeutic peptide, HTL-001, capable of targeting HOX gene over-expression in GBM by disrupting the interaction between HOX proteins and their co-factor, PBX. HTL-001 induced both caspase-dependent and -independent apoptosis in GBM cell lines. In vivo biodistribution studies confirmed that the peptide was able to cross the blood brain barrier. Systemic delivery of HTL-001 resulted in improved control of subcutaneous murine and human xenograft tumours and improved survival in a murine orthotopic model.

It is now well-recognized that the tumor microenvironment (TME) is not only a key regulator of cancer progression but also plays a crucial role in cancer treatment responses. Recently, several high-profile publications have demonstrated the importance of particular immune parameters and cell types that dictate responsiveness to immunotherapies. With this increased understanding of TME-mediated therapy, approaches that increase therapeutic efficacy by remodeling the TME are actively being pursued. A classic example of this, in practice by urologists for over 40 years, is the manipulation of the bladder microenvironment for the treatment of non-muscle invasive bladder cancer (NMIBC) by instillation of intravesical bacillus Calmette-Guerin (BCG). The success of BCG treatment is thought to be due to its ability to induce a massive influx of Th1-polarized inflammatory cells, production of Th1 inflammatory cytokines and the generation of tumor-targeted Th1-mediated cytotoxic responses. Whilst BCG immunotherapy is currently the best treatment for NMIBC, similar to 30% of patients show no response to this treatment. Here we present a review highlighting a variety of promising alternative immunotherapies being developed that remodel the bladder tumor microenvironment. These include (1) the use of oncolytic viruses which selectively replicate within cancer cells whilst also modifying the immunological components of the TME, (2) manipulation of the bladder microbiome to augment the response to BCG or other immunotherapies (3) utilizing Toll-like Receptor agonists as anti-tumor agents due to their potent stimulation of innate and adaptive immunity and (4) the growing recognition that immunotherapeutic strategies that will have the largest impact on patients may require multiple therapeutic approaches combined together. The accumulating knowledge on TME remodeling holds promise for providing an alternative therapy for patients with BCG-unresponsive NMIBC.

Abstract Introduction: Triple Negative Breast Cancer (TNBC) is a heterogeneous disease, clinically defined for its aggressive tumour behaviour, metastatic ability and poor prognosis. Homeobox (HOX) genes are a family of homeodomain-containing transcription factors, which establish and maintain the identity and fate of cells and tissues during normal embryogenesis and organ development. A total of 39 HOX genes exist, located in four clusters (A-D) on different chromosomes. HOX genes are dysregulated in most cancers and they have an established role in driving key processes in breast carcinogenesis, including the regulation of the cell cycle, apoptosis, angiogenesis and metastasis. In this study, we evaluated the anti-tumour efficacy of a novel inhibitor of HOX protein function, HTL-001, which antagonizes the interactions between HOX proteins and their PBX cofactors. HTL-001, developed by HOX Therapeutics Ltd, is a synthetic peptide of 18 amino acids, comprised of a hexapeptide sequence, which resembles that on HOX proteins of paralogs 1-9, and a short C-terminal polyarginine sequence for cell penetration. We evaluated the efficacy of HTL-001 in vitro as a monotherapy in all cell lines representing all molecular classifications of breast cancer and in combination with chemotherapeutics for TNBC therapy. Most importantly, HTL-001 was examined in MDA-MB-231-BR cells, which have a propensity to metastasise to the brain, reflecting the disease course frequently observed in human patients. Methods: The differential expression of HOX and PBX genes in all subtypes of breast cancer was evaluated using bioinformatics analysis of TCGA and Oncomine data. The sensitivity to HTL-001 of breast cancer-derived cell lines of different molecular classifications, was determined using Cell Proliferation (MTS) Assay and FACS-based Annexin Assay. The anti-tumour effect of HTL-001 in combination with various chemotherapeutics was assessed and analysed for synergy using Bliss Analysis. The expression of genes previously shown to respond to HOX/PBX inhibition was measured from extracted RNA and protein using RT-qPCR and western blotting, respectively. The in vivo efficacy of HTL-001 will be investigated using a mouse flank tumour xenograft model with MDA-MB-231-BR cells, representative of TNBC. Results: TCGA and Oncomine data analysis showed TNBC tumours have a unique signature of HOX gene dysregulation, different to that of all other types of breast tumours, relative to normal breast tissues; most importantly upregulation in HOXB2 and HOXB3 genes. Targeting HOX/PBX dimers with HTL-001, induced apoptotic cell death in all breast cancer cell lines including; MCF-7, ZR-75-1, MDA-MB-231, BT-20 and SK-BR-3, with the highest sensitivity seen in brain seeking MDA-MB-231-BR cells. HTL-001 significantly upregulated the expression of key apoptotic and anti-survival genes including; AIF, cFOS, and DUSP1, resulting in the induction of apoptotic cell death in all breast cancer cell lines tested. Furthermore, we observed high levels of synergy between HTL-001 and the chemotherapeutic agents, Paclitaxel, Palbociclib and 5-Fluorouracil. Conclusion: HTL-001 is a novel inhibitor of HOX and PBX protein interactions capable of marked in vitro cytotoxicity in all types of breast cancer cells, particularly in TNBC. HTL-001 induced rapid apoptosis and triggered a downstream unique signature after target engagement. HTL-001 is currently the only therapy which targets HOX gene dysregulation and in doing so, may help address the current urgent unmet therapeutic need in TNBC through its unique mechanism of action and high levels of synergy with conventional anti-cancer agents. Citation Format: Einthavy Arunachalam, Guy R Simpson, Carla Sofia Möller-Levet, Nicola Annels, Richard Morgan, Timothy Robert Crook, Hardev Singh Pandha. Therapeutic targeting of HOX gene dysregulation in triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-10-15.

Context: About 50–70% of patients with non-muscle invasive bladder cancer (NMIBC) experience relapse of disease. Objective: To establish a panel of protein biomarkers incorporated in a multiplexed microarray (BCa chip) and a classifier for diagnosing recurrent NMIBC. Materials and methods: Urine samples from 45 patients were tested. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis. Results: A multi biomarker panel (ECadh, IL8, MMP9, EN2, VEGF, past recurrences, BCG therapies and stage at diagnosis) was identified yielding an area under the curve of 0.96. Discussion and conclusion: This biomarker panel represents a potential diagnostic tool for noninvasive diagnosis of recurrent NMIBC.

Urothelial carcinoma of the urinary bladder (UCB) or bladder cancer remains a major health problem with high morbidity and mortality rates, especially in the western world. UCB is also associated with the highest cost per patient. In recent years numerous markers have been evaluated for suitability in UCB detection and surveillance. However, to date none of these markers can replace or even reduce the use of routine tools (cytology and cystoscopy). Our current study described UCB's extensive expression profile and highlighted the variations with normal bladder tissue. Our data revealed that JUP, PTGDR, KLRF1, MT-TC , and RNU6-135P are associated with prognosis in patients with UCB. The microarray expression data identified also S100A12, S100A8 , and NAMPT as potential UCB biomarkers. Pathway analysis revealed that natural killer cell mediated cytotoxicity is the most involved pathway. Our analysis showed that S100A12 protein may be useful as a biomarker for early UCB detection. Plasma S100A12 has been observed in patients with UCB with an overall sensitivity of 90.5% and a specificity of 75%. S100A12 is highly expressed preferably in high-grade and high-stage UCB. Furthermore, using a panel of more than hundred urine samples, a prototype lateral flow test for the transcription factor Engrailed-2 (EN2) also showed reasonable sensitivity (85%) and specificity (71%). Such findings provide confidence to further improve and refine the EN2 rapid test for use in clinical practice. In conclusion, S100A12 and EN2 have shown potential value as biomarker candidates for UCB patients. These results can speed up the discovery of biomarkers, improving diagnostic accuracy and may help the management of UCB.

Oncolytic viruses are biological agents which can easily be delivered at high doses directly to the bladder through a catheter (intravesical), with low risk of systemic uptake and toxicity. To date, a number of viruses have been delivered intravesically in patients and in murine models with bladder cancer and antitumour effects demonstrated. Here, we describe in vitro methods to evaluate Coxsackie virus, CVA21, as an oncolytic virus for the treatment of human bladder cancer by determining the susceptibility of bladder cancer cell lines expressing differing levels of ICAM-1 surface receptor to CVA21.

The HOX genes are a family of closely related transcription factors that help to define the identity of cells and tissues during embryonic development and which are also frequently deregulated in a number of malignancies, including breast cancer. While relatively little is known about the roles that individual HOX genes play in cancer, it is however clear that these roles can be both contradictory, with some members acting as oncogenes and some as tumor suppressors, and also redundant, with several genes essentially having the same function. Here, we have attempted to address this complexity using the HXR9 peptide to target the interaction between HOX proteins and PBX, a second transcription factor that serves as a common co-factor for many HOX proteins. We show that HXR9 causes apoptosis in a number of breast cancer-derived cell lines and that sensitivity to HXR9 is directly related to the averaged expression of HOX genes HOXB1 through to HOXB9, providing a potential biomarker to predict the sensitivity of breast tumors to HXR9 or its derivatives. Measuring the expression of HOX genes HOXB1-HOXB9 in primary tumors revealed that a subset of tumors show highly elevated expression indicating that these might be potentially very sensitive to killing by HXR9. Furthermore, we show that while HXR9 blocks the oncogenic activity of HOX genes, it does not affect the known tumor-suppressor properties of a subset of HOX genes in breast cancer.

As a clinical setting in which local live biological therapy is already well established, non-muscle invasive bladder cancer (NMIBC) presents intriguing opportunities for oncolytic virotherapy. Coxsackievirus A21 (CVA21) is a novel intercellular adhesion molecule-1 (ICAM-1)-targeted immunotherapeutic virus. This study investigated CVA21-induced cytotoxicity in a panel of human bladder cancer cell lines, revealing a range of sensitivities largely correlating with expression of the viral receptor ICAM-1. CVA21 in combination with low doses of mitomycin-C enhanced CVA21 viral replication and oncolysis by increasing surface expression levels of ICAM-1. This was further confirmed using 300-μm precision slices of NMIBC where levels of virus protein expression and induction of apoptosis were enhanced with prior exposure to mitomycin-C. Given the importance of the immunogenicity of dying cancer cells for triggering tumor-specific responses and long-term therapeutic success, the ability of CVA21 to induce immunogenic cell death was investigated. CVA21 induced immunogenic apoptosis in bladder cancer cell lines, as evidenced by expression of the immunogenic cell death (ICD) determinant calreticulin, and HMGB-1 release and the ability to reject MB49 tumors in syngeneic mice after vaccination with MB49 cells undergoing CVA21 induced ICD. Such CVA21 immunotherapy could offer a potentially less toxic, more effective option for the treatment of bladder cancer.

Reovirus type 3 Dearing (T3D) has demonstrated oncolytic activity in vitro, in in vivo murine models and in early clinical trials. However the true potential of oncolytic viruses may only be realized fully in combination with other modalities such as chemotherapy, targeted therapy and radiotherapy. In this study, we examine the oncolytic activity of reovirus T3D and chemotherapeutic agents against human prostate cancer cell lines, with particular focus on the highly metastatic cell line PC3 and the chemotherapeutic agent docetaxel. Docetaxel is the standard of care for metastatic prostate cancer and acts by disrupting the normal process of microtubule assembly and disassembly. Reoviruses have been shown to associate with microtubules and may require this association for efficient viral replication.

Oncolytic viruses are multifunctional anticancer agents with huge clinical potential, and have recently passed the randomized Phase III clinical trial hurdle. Both wild-type and engineered viruses have been selected for targeting of specific cancers, to elicit cytotoxicity, and also to generate antitumor immunity. Single-agent oncolytic virotherapy treatments have resulted in modest effects in the clinic. There is increasing interest in their combination with cytotoxic agents, radiotherapy and immune-checkpoint inhibitors. Similarly to oncolytic viruses, the benefits of chemotherapeutic agents may be that they induce systemic antitumor immunity through the induction of immunogenic cell death of cancer cells. Combining these two treatment modalities has to date resulted in significant potential in vitro and in vivo synergies through various mechanisms without any apparent additional toxicities. Chemotherapy has been and will continue to be integral to the management of advanced cancers. This review therefore focuses on the potential for a number of common cytotoxic agents to be combined with clinically relevant oncolytic viruses. In many cases, this combined approach has already advanced to the clinical trial arena. Keywords: oncolytic virotherapy, chemotherapy, immunogenic cell death

Reovirus type 3 Dearing (Reolysin, Oncolytics Biotech) is a wild-type double-stranded RNA virus that is ubiquitous and nonpathogenic in humans. It has been shown to be oncolytic by its ability to replicate in transformed cells but not in normal cells. Reovirus has been shown to exert significant antitumor effects in both preclinical in vitro and in vivo studies. In addition, reovirus can activate both innate and adaptive antitumor response against human and murine tumors. However, despite antitumor activity, the responses to reovirus monotherapy in human trials have been modest and short-lived. As a result, a number of potential strategies for improving antitumor efficacy are currently being evaluated. This chapter describes the application of oncolytic reovirus as an anticancer agent, alone or in combination with conventional therapies such as radiotherapy and chemotherapeutics. It also summarizes current clinical trials on reovirus therapy. © 2014 Elsevier Inc. All rights reserved.