Spatial competition and agglomeration in the visitor attraction sector

This paper provides a theoretical and empirical contribution to understanding spatial competition by examining visitor attractions in two contrasting clusters of lower and higher levels of agglomeration of businesses in Cornwall, the UK. The study found that competition is mainly for customers and labour and is related differently to the levels of agglomeration, spatial proximity and thematic product similarity between visitor attractions at the local compared to the regional scale. Location can be used differently for employing ‘weak’ and ‘strong’ competitive strategies. The study contributes to the knowledge on the spatiality of competition and the locational strategies of service businesses

Waste recycling: utilization of coffee grounds and kitchen waste in vermicomposting

Vermicomposting using Lumbricus rubellus for 49 days was conducted after 21 days of pre-composting. Three different combination of treatments were prepared with eight replicates for each treatment namely cow dung: kitchen waste in 30:70 ratio (T(1)), cow dung: coffee grounds in 30:70 ratio (T(2)), and cow dung: kitchen waste: coffee grounds in 30:35:35 ratio (T(3)). The multiplication of earthworms in terms of numbers and weight were measured at the end of vermicomposting. Consequently, only T(2) showed significant increase (from it initial stage) compared to other treatments. The presence of coffee grounds in T(2) and T(3) showed higher percentage of nutrient elements in vermicompost produced. The data reveal that coffee grounds can be decomposed through vermicomposting and help to enhance the quality of vermicompost produced rather than sole use of kitchen waste in vermicomposting

Development of novel lipidic particles for siRNA delivery that are highly effective after 12 months storage

Liposomes are versatile and well-proven as a means to deliver nucleic acids into cells. Most of the formulation procedures used are labour intensive and result in unstable end products. We have previously reported on the development of a simple, yet efficient, hydration-of-freeze-dried-matrix (HFDM) method to entrap siRNA within lipid particles. Here we show that the particles are stable up to 12 months after storage at room temperature (RT), 4°C or -20°C. While RT storage results in changes in particle size and polydispersity, gene silencing of all particles was similar to freshly prepared particles following storage for 3, 6, 9 or 12 months at all temperatures. This is the first report of such long-term stability in siRNA-loaded liposomes.</p

Hyperactivating p53 in Human Papillomavirus-Driven Cancers : A Potential Therapeutic Intervention

Despite a vaccine being available, human papillomavirus virus (HPV)-driven cancers remain the ninth most prevalent cancers globally. Current therapies have significant drawbacks and often still lead to poor prognosis and underwhelming survival rates. With gene therapy becoming more available in the clinic, it poses a new front for therapeutic development. A characteristic of HPV-driven cancers is the ability to encode oncoproteins that aberrate normal p53 function without mutating this tumour-suppressor gene. The HPV E6 oncoprotein degrades p53 to allow the HPV-driven carcinogenic process to proceed. This review aimed to investigate the use of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) gene-editing technology and how it may be used to overcome HPV-mediated silencing of p53 by hyper-expressing the p53 promoter. Increasing p53 bioavailability may have promising potential as a therapy and has been a goal in the context of HPV-driven cancers. Clinical trials and proof-of-concept pre-clinical work have shown positive outcomes and tumour death when p53 levels are increased. Despite previous successes of RNA-based medicines, including the knockout of HPV oncogenes, the use of CRISPR activation is yet to be investigated as a promising potential therapy. This short review summarises key developments on attempts that have been made to increase p53 expression in the context of HPV cancer therapy, but leaves open the possibility for other cancers bearing a p53 wild-type gene.</p

RNAi to treat SARS-CoV-2-variant proofing the next generation of therapies

There is an urgent need to bring new antivirals to SARS-CoV-2 to the market. Indeed, in the last 3 months, we have seen at least two new antivirals approved, molnupiravir and paxlovid. Both are older established antivirals that show some efficacy against SARS-CoV-2. The work by Chang et al (2022) in the current issue of EMBO Molecular Medicine explores the use of short interfering RNAs to directly target SARS-CoV-2 and shows that RNAi is an effective approach to reducing, or even eliminating viral replication, depending on the experimental setting. This antiviral effect results in significant prevention of infection-related pathology in animals. The key feature of this approach, besides its simplicity as naked siRNAs, is that all current variants are covered by this treatment.</p

Genetic deletion of HPV E7 oncogene effectively regresses HPV driven oral squamous carcinoma tumour growth

The major HPV oncogenes, E6 and E7, are known for its notoriety in driving the carcinogenic process in human papilloma virus (HPV) driven cancers. It is well-established that the removal of E7 dampens HPV cancer cell growth and proliferation. This has made E7 an attractive target for HPV cancers. Seminal work from our laboratory employed a CRISPR editing approach to delete E7 which resulted in the effective elimination of HPV+ cervical cancer tumours in vivo. We have also successfully delayed HPV+ tumour growth in vivo with aurora kinase (AURK) inhibitors, an effect which is strongly sensitized by the presence of E7. Unlike our previous observations in cervical cancer cells, in vitro targeting of E6/E7 have only resulted in partial killing of HPV+ oral squamous carcinoma (OSC) cells. However, the effect of sustained removal of E7 on HPV+ OSC tumour growth have not been explored. In this study, we investigated a staggered combination of aurora kinase inhibition, using alisertib, followed by CRISPR editing of E7, to determine if this would lead to better HPV+ OSC killing. Remarkably, genetic deletion of E7 alone was sufficient to effectively regress established HPV+ OSC tumours in vivo suggesting that E7 is essential in the maintenance of HPV+ OSC cancers

A 'hit-and-run' affair – A possible link for cancer progression in virally driven cancers

Background: It is well-known that certain cancers are caused by viruses. However, viral oncogenesis is complex and only a small fraction of the infected people develop cancer. Indeed, a number of environmental factors can contribute to virally infected cells developing cancer hallmarks, promoting tumorigenesis. Scope of review: The hit-and-run theory proposes that viruses facilitate the accumulation of mutations and promote genomic instability until the virus becomes dispensable for tumour maintenance. Indeed, several studies have reported viral genome, episome and/or oncogene loss in tumour cells without losing malignant phenotype. Major conclusions: The current evidence supports the clear contribution of certain viruses to develop cancers. Importantly, the evidence supporting the sustained maintenance of malignancy after the loss of viral “presence” is sufficient to support the hit-and-run hypothesis of viral cancer development. Long-term tracking of vaccination outcome over the decades will test this theory. General significance: If the hit-and-run theory is true, viruses might cause more cancers than previously thought and will have implications in the prevention of many cancers through implementing vaccination programs.</p

An intranasally delivered ultra-conserved siRNA prophylactically represses SARS-CoV-2 infection in the lung and nasal cavity

There remains a striking overall mortality burden of COVID-19 worldwide. Given the waning effectiveness of current SARS-CoV-2 antivirals due to the rapid emergence of new variants of concern (VOC), we employed a direct-acting molecular therapy approach using gene silencing RNA interference (RNAi) technology. In this study, we developed and screened several ultra-conserved small-interfering RNAs (siRNAs) before selecting one potent siRNA candidate for pre-clinical in vivo testing. This non-immunostimulatory, anti-SARS-CoV-2 siRNA candidate maintains its antiviral activity against all tested SARS-CoV-2 VOC and works effectively as a single agent. For the first time, significant antiviral effects in both the lungs and nasal cavities of SARS-CoV-2 infected mice were observed when this siRNA candidate was delivered intranasally (IN) as a prophylactic agent with the aid of lipid nanoparticles (LNPs). Importantly, a pre-exposure prophylactic IN-delivered anti-SARS-CoV-2 siRNA antiviral that can ameliorate viral replication in the nasal cavity could potentially prevent aerosol spread of respiratory viruses. An IN delivery approach would allow for the development of a direct-acting nasal spray approach that could be self-administered prophylactically.</p

Extracellular Vesicles Loaded with Long Antisense RNAs Repress Severe Acute Respiratory Syndrome Coronavirus 2 Infection

Long antisense RNAs (asRNAs) have been observed to repress HIV and other virus expression in a manner that is refractory to viral evolution. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease 2019 (COVID-19) disease, has a distinct ability to evolve resistance around antibody targeting, as was evident from the emergence of various SARS-CoV-2 spike antibody variants. Importantly, the effectiveness of current antivirals is waning due to the rapid emergence of new variants of concern, more recently the omicron variant. One means of avoiding the emergence of viral resistance is by using long asRNA to target SARS-CoV-2. Similar work has proven successful with HIV targeting by long asRNA. In this study, we describe a long asRNA targeting SARS-CoV-2 RNA-dependent RNA polymerase gene and the ability to deliver this RNA in extracellular vesicles (EVs) to repress virus expression. The observations presented in this study suggest that EV-delivered asRNAs are one means to targeting SARS-CoV-2 infection, which is both effective and broadly applicable as a means to control viral expression in the absence of mutation. This is the first demonstration of the use of engineered EVs to deliver long asRNA payloads for antiviral therapy.</div