RESUMEN
BACKGROUND: Tigilanol tiglate (TT) is a protein kinase C (PKC)/C1 domain activator currently being developed as an intralesional agent for the treatment of various (sub)cutaneous malignancies. Previous work has shown that intratumoral (I.T.) injection of TT causes vascular disruption with concomitant tumor ablation in several preclinical models of cancer, in addition to various (sub)cutaneous tumors presenting in the veterinary clinic. TT has completed Phase I dose escalation trials, with some patients showing signs of abscopal effects. However, the exact molecular details underpinning its mechanism of action (MoA), together with its immunotherapeutic potential in oncology remain unclear. METHODS: A combination of microscopy, luciferase assays, immunofluorescence, immunoblotting, subcellular fractionation, intracellular ATP assays, phagocytosis assays and mixed lymphocyte reactions were used to probe the MoA of TT in vitro. In vivo studies with TT used MM649 xenograft, CT-26 and immune checkpoint inhibitor refractory B16-F10-OVA tumor bearing mice, the latter with or without anti-programmed cell death 1 (PD-1)/anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) mAb treatment. The effect of TT at injected and non-injected tumors was also assessed. RESULTS: Here, we show that TT induces the death of endothelial and cancer cells at therapeutically relevant concentrations via a caspase/gasdermin E-dependent pyroptopic pathway. At therapeutic doses, our data demonstrate that TT acts as a lipotoxin, binding to and promoting mitochondrial/endoplasmic reticulum (ER) dysfunction (leading to unfolded protein responsemt/ER upregulation) with subsequent ATP depletion, organelle swelling, caspase activation, gasdermin E cleavage and induction of terminal necrosis. Consistent with binding to ER membranes, we found that TT treatment promoted activation of the integrated stress response together with the release/externalization of damage-associated molecular patterns (HMGB1, ATP, calreticulin) from cancer cells in vitro and in vivo, characteristics indicative of immunogenic cell death (ICD). Confirmation of ICD in vivo was obtained through vaccination and rechallenge experiments using CT-26 colon carcinoma tumor bearing mice. Furthermore, TT also reduced tumor volume, induced immune cell infiltration, as well as improved survival in B16-F10-OVA tumor bearing mice when combined with immune checkpoint blockade. CONCLUSIONS: These data demonstrate that TT is an oncolytic small molecule with multiple targets and confirms that cell death induced by this compound has the potential to augment antitumor responses to immunotherapy.
Asunto(s)
Inhibidores de Puntos de Control Inmunológico , Muerte Celular Inmunogénica , Animales , Ratones , Muerte Celular Inmunogénica/efectos de los fármacos , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Línea Celular Tumoral , Femenino , Ensayos Antitumor por Modelo de Xenoinjerto , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Neoplasias/terapiaRESUMEN
Human papillomavirus (HPV)-related oropharyngeal cancer (OPC) is increasing in incidence, yet very little is known about oral HPV infection in the general population. In this Australian-based study we assess oral HPV prevalence according to HPV vaccination status. Participants of the Oral Diversity Study were Australian residents, aged 18 to 70 years, who filled out a questionnaire about lifestyle and sexual behaviour, and donated a saliva sample in 2020 to 2021. We obtained permission to access HPV vaccination status through record linkage with the Australian Immunisation Register. Saliva samples were DNA extracted, DNA quality checked and analysed for HPV. We recruited 1023 participants to the Oral Diversity Study. Nine hundred twenty-one returned a saliva sample for analysis, 911 passed the DNA quality check and were included in the study. The oral HPV prevalence was 7.2%, and was strongly associated with sexual behaviours. We identified 27 different HPV types; 53% of participants carried high-risk HPV types, with no difference between the vaccinated and the unvaccinated groups (53% both, P = .979). Two hundred thirty participants (26%) were HPV vaccinated. The oral prevalence of the nine HPV types included in the nonavalent HPV vaccine was significantly lower in the vaccinated participants compared to the unvaccinated (0.9% vs 3.4%; P = .022). These findings suggest that a sizeable minority of Australian residents harbour oral HPV infections, and many of these are high-risk subtypes. We found some evidence that HPV vaccination resulted in lower prevalence of oral HPV infections of vaccine-specific types. Larger surveys are required to confirm these findings.
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Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Humanos , Australia/epidemiología , Virus del Papiloma Humano , Papillomaviridae , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/prevención & control , Prevalencia , Vacunación , Boca/virología , Saliva/virologíaRESUMEN
Oropharyngeal cancer is increasingly caused by human papillomavirus (HPV), and this increase is believed to be caused by changing sexual behaviour. It has been hypothesised that an immune response to HPV through sexual intercourse is much stronger than an immune response elicited from oral sex. Therefore, people who have their debut of oral sex before or at the same time as sexual intercourse would have a weaker immune response to HPV and hence be more likely to develop a persistent oral HPV infection and oropharyngeal cancer. Drake et al (Cancer. 2021;127[7]:1029-1038) found some evidence that supported this hypothesis. We have reanalysed two of our Australian cohorts with similar data in order to provide a perspective of Drake and colleagues' publication, as sexual behaviour varies depending on culture and geographical location. We found that engaging in oral sex (OR 4.46, 95% CI [1.88-10.62]) and being younger than 20 years at oral sex debut (OR 9.46, 95% CI [3.53-25.31]) were both very strong risk factors for oropharyngeal cancer. Participants in the general population cohort who had their sexual intercourse debut before the age of 18 were more likely to be oral HPV positive (OR 2.69, 95% CI [1.50-4.83]). Oral sex debut before sexual intercourse debut was quite uncommon in our two Australian cohorts. However, timing of or sexual debuts may further add to risks of oropharyngeal cancer, and future studies should be designed to investigate timing and order of sexual debuts to help clarify the roles of these potential causal factors.
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Alphapapillomavirus , Neoplasias Orofaríngeas , Infecciones por Papillomavirus , Australia/epidemiología , Humanos , Neoplasias Orofaríngeas/epidemiología , Neoplasias Orofaríngeas/etiología , Papillomaviridae , Prevalencia , Factores de Riesgo , Conducta SexualRESUMEN
Oral infection with human papillomavirus (HPV) is likely to underpin the rapidly rising incidence of oropharyngeal squamous cell carcinoma; however, there are few data describing the natural history of oral HPV infection. We recruited 704 participants aged 20 to 70 years from worksites, universities and primary care practices in Brisbane, Australia. Participants completed questionnaires at baseline, 12 and 24 months and donate four saliva samples at baseline, 6, 12 and 24 months for HPV polymerase chain reaction testing and typing. We estimated the prevalence of oral HPV infection at baseline, incidence of new infections among those HPV-negative at baseline, clearance rate and persistent infections. At baseline, 10.7% of participants had oral HPV infections from 26 different HPV types. Sexual behaviours were associated with oral HPV infection, including more partners for passionate kissing (29 or more; odds ratio [OR] 3.4, 95% confidence interval [CI] 1.5-8.0), and giving and receiving oral sex (16 or more; OR 5.4, 95% CI 1.6-17.7 and OR 5.6, 95% CI 1.6-18.7, respectively). Of 343 participants, HPV-free at baseline and with subsequent saliva samples, 87 (25%) acquired new infections over the 24 months. Sixty-eight of 87 people included in the clearance analysis (78%) cleared their oral HPV infections. Clearance was associated with being a nonsmoker (OR 12.7, 95% CI 1.3-122.8), and no previous diagnosis of a sexually transmitted infection (OR 6.2, 95% CI 2.0-19.9). New oral infections with HPV in this sample were not rare. Although most infections were cleared, clearance was not universal suggesting a reservoir of infection exists that might predispose to oropharyngeal carcinogenesis.
Asunto(s)
Carcinoma de Células Escamosas/diagnóstico , Enfermedades de la Boca/diagnóstico , Neoplasias Orofaríngeas/diagnóstico , Infecciones por Papillomavirus/diagnóstico , Encuestas y Cuestionarios , Adulto , Anciano , Alphapapillomavirus/clasificación , Alphapapillomavirus/fisiología , Australia/epidemiología , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/virología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Enfermedades de la Boca/epidemiología , Enfermedades de la Boca/virología , Neoplasias Orofaríngeas/epidemiología , Neoplasias Orofaríngeas/virología , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Prevalencia , Estudios Prospectivos , Saliva/virología , Conducta Sexual/estadística & datos numéricos , Factores de Tiempo , Adulto JovenRESUMEN
Importance: Human papillomavirus (HPV) infection is associated with oropharyngeal squamous cell carcinoma. International estimates suggest overall oral HPV prevalence is 7.5%, with prevalence of oral HPV types 16 and 18 being 1.6%; prior Australian estimates suggest oral HPV prevalence is 2.3%, with HPV-16 and HPV-18 being 1.3%. Objectives: To estimate the prevalence of oral HPV infection among Indigenous Australians and to report the prevalence of factors associated with high-risk HPV types (ie, HPV-16 and HPV-18) and HPV types linked with Heck disease (ie, HPV-13 and HPV-32). Design, Setting, and Participants: This cross-sectional study analyzed HPV screening results from saliva samples collected from 1011 Indigenous Australians between February 2018 and January 2019. Data were analyzed from May 2018 to May 2019. Recruitment occurred through Aboriginal Community Controlled Health Organisations in South Australia. Eligibility included identifying as Indigenous, residing in South Australia, and being aged 18 years or older. Main Outcomes and Measures: Saliva samples were collected, with microbial DNA for genotyping extracted. Sociodemographic parameters, health-related behaviors, and sexual history data were collected. Analyses were stratified by sex as well as by HPV types 13 and 32 (Heck disease) and 16 and 18 (high risk of oropharyngeal squamous cell carcinoma). Multivariable analyses were conducted to obtain adjusted odds ratios (ORs). Results: Data were obtained for 910 participants (median [interquartile range] age, 37 [27-51] years); 595 participants (65%) were female and 572 (63%) resided in nonmetropolitan locations. In all, 321 saliva samples (35.3%; 95% CI, 32.2%-38.4%) were positive for oral HPV (106 [33.7%] men; 215 [36.1%] women). The highest prevalence was found for HPV types 13 and 32 (207 [22.7%] total; 60 [19.0%] men; 147 [24.7%] women) followed by HPV types 16 and 18 (30 [3.3%] total; 9 [2.9%] men; 21 [3.5%] women). After multivariable analysis, risk factors associated with HPV types 13 and 32 included nonmetropolitan residential status (OR, 2.06; 95% CI, 1.10-3.88) and not having had a tonsillectomy (OR, 2.74; 95% CI, 1.05-7.16). Among women, having obtained a high school education or less was associated with lower odds of HPV-16 and HPV-18 infection (OR, 0.16; 95% CI, 0.03-0.97). Conclusions and Relevance: Prevalence of oral HPV infection in a large sample of Indigenous Australians was high, with one-third testing positive. The most prevalent HPV types were those associated with Heck disease. The prevalence of HPV types associated with oropharyngeal squamous cell carcinoma exceeded both Australian and international population-level estimates.
Asunto(s)
Hiperplasia Epitelial Focal/epidemiología , Nativos de Hawái y Otras Islas del Pacífico/estadística & datos numéricos , Neoplasias Orofaríngeas/virología , Infecciones por Papillomavirus/epidemiología , Infecciones por Papillomavirus/virología , Carcinoma de Células Escamosas de Cabeza y Cuello/virología , Adulto , Australia/epidemiología , Estudios Transversales , Escolaridad , Femenino , Hiperplasia Epitelial Focal/virología , Conductas Relacionadas con la Salud , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Población Rural/estadística & datos numéricos , Saliva/virología , Conducta Sexual/estadística & datos numéricos , Parejas Sexuales , Tonsilectomía/estadística & datos numéricos , Población Urbana/estadística & datos numéricosRESUMEN
Very little is known about the natural history of oral HPV infection. Several different methods exist to collect oral specimens and detect HPV, but their respective performance characteristics are unknown. We compared two different methods for oral specimen collection (oral saline rinse and commercial saliva kit) from 96 individuals and then analyzed the samples for HPV by two different PCR detection methods (single GP5+/6+ PCR and nested MY09/11 and GP5+/6+ PCR). For the oral rinse samples, the oral HPV prevalence was 10.4% (GP+ PCR; 10% repeatability) vs 11.5% (nested PCR method; 100% repeatability). For the commercial saliva kit samples, the prevalences were 3.1% vs 16.7% with the GP+ PCR vs the nested PCR method (repeatability 100% for both detection methods). Overall the agreement was fair or poor between samples and methods (kappa 0.06-0.36). Standardizing methods of oral sample collection and HPV detection would ensure comparability between future oral HPV studies.