Interferon-ε is a tumour suppressor and restricts ovarian cancer.

High-grade serous ovarian cancers have low survival rates because of their late presentation with extensive peritoneal metastases and frequent chemoresistance1, and require new treatments guided by novel insights into pathogenesis. Here we describe the intrinsic tumour-suppressive activities of interferon-ε (IFNε). IFNε is constitutively expressed in epithelial cells of the fallopian tube, the cell of origin of high-grade serous ovarian cancers, and is then lost during development of these tumours. We characterize its anti-tumour activity in several preclinical models: ovarian cancer patient-derived xenografts, orthotopic and disseminated syngeneic models, and tumour cell lines with or without mutations in Trp53 and Brca genes. We use manipulation of the IFNε receptor IFNAR1 in different cell compartments, differential exposure status to IFNε and global measures of IFN signalling to show that the mechanism of the anti-tumour activity of IFNε involves direct action on tumour cells and, crucially, activation of anti-tumour immunity. IFNε activated anti-tumour T and natural killer cells and prevented the accumulation and activation of myeloid-derived suppressor cells and regulatory T cells. Thus, we demonstrate that IFNε is an intrinsic tumour suppressor in the female reproductive tract whose activities in models of established and advanced ovarian cancer, distinct from other type I IFNs, are compelling indications of potential new therapeutic approaches for ovarian cancer.

Examining the impact of a universal positive psychology program on mental health outcomes among Australian secondary students during the COVID-19 pandemic.

BACKGROUND: This study aimed to examine the impact of a web-based positive psychology program delivered universally to secondary school students during school closures caused by the COVID-19 pandemic in New South Wales, Australia. METHODS: Using a quasi-experimental design conducted in 2020, 438 students aged 12-15 years (73% male) from 4 secondary schools were invited to complete the 'Bite Back Mental Fitness Challenge'. This web-based program consisted of 7 self-directed modules that targeted 5 key domains of positive psychology. Self-reported symptoms of anxiety and depression and help-seeking intentions for mental health were assessed at baseline prior to school closures (February to March 2020) and at post-test after the return to school (July to August 2020). At post-test, students also reported on their perceived changes in mental health and help-seeking behavior for mental health during the pandemic. Completion of the program modules was recorded. RESULTS: A total of 445 students consented and 336 (75.5%) completed both assessments. On average, participants completed 2.31 modules (SD: 2.38, range: 0 to 7). There was no change in symptoms of anxiety and depression or help-seeking intentions between baseline and post-test, with no significant effects for gender and history of mental illness. Students who were symptomatic for anxiety and depression at baseline reported lower symptoms at post-test, but this change was not significant. Ninety-seven students (27.5%) reported that their mental health had worsened during the pandemic, and a significant increase in anxiety and depressive symptoms was found in this subsample at post-test. Only 7.7% of students reported a change in their help-seeking behavior, with increased mental health support sought from the Internet, parents, and friends. CONCLUSIONS: The universal delivery of a web-based positive psychology program during school closures did not appear to be associated with improved mental health symptoms; however, completion of the modules was low. Different effects may emerge when selectively delivered to students with mild or greater symptoms. The findings also suggest that broader measures of mental health and wellbeing, including perceived change, are key to the mental health surveillance of students during periods of remote learning.

Investigating the Role of Heparanase in Breast Cancer Development Utilising the MMTV-PyMT Murine Model of Mammary Carcinoma.

Breast cancer is the second most common human malignancy and is a major global health burden. Heparanase (HPSE) has been widely implicated in enhancing the development and progression of solid tumours, including breast cancer. In this study, the well-established spontaneous mammary tumour-developing MMTV-PyMT murine model was utilised to examine the role of HPSE in breast cancer establishment, progression, and metastasis. The use of HPSE-deficient MMTV-PyMT (MMTV-PyMTxHPSE-/-) mice addressed the lack of genetic ablation models to investigate the role of HPSE in mammary tumours. It was demonstrated that even though HPSE regulated mammary tumour angiogenesis, mammary tumour progression and metastasis were HPSE-independent. Furthermore, there was no evidence of compensatory action by matrix metalloproteinases (MMPs) in response to the lack of HPSE expression in the mammary tumours. These findings suggest that HPSE may not play a significant role in the mammary tumour development of MMTV-PyMT animals. Collectively, these observations may have implications in the clinical setting of breast cancer and therapy using HPSE inhibitors.

AlphaBet: Combination of Radium-223 and [17 7Lu]Lu-PSMA-I&T in men with metastatic castration-resistant prostate cancer (clinical trial protocol).

Background: [177Lu]Lu-PSMA is a radioligand therapy used in metastatic castration-resistant prostate cancer (mCRPC). Despite a survival benefit, the responses for many patients receiving [177Lu]Lu-PSMA are not durable, and all patients eventually develop progressive disease. The bone marrow is the most common site of progression. Micrometastases in this area likely receive an inadequate dose of radiation, as the emitted beta-particles from 177Lu travel an average range of 0.7 mm in soft tissue, well beyond the diameter of micrometastases. Radium-223 (223Ra) is a calcium-mimetic and alpha-emitting radionuclide approved for use in men with mCRPC with bone metastases. The range of emitted alpha particles in soft tissue is much shorter (≤100 µm) with high linear energy transfer, likely more lethal for osseous micrometastases. We anticipate that combining a bone-specific alpha-emitter with [177Lu]Lu-PSMA will improve eradication of micrometastatic osseous disease, and thereby lead to higher and longer responses. Methods: This is a single-center, single-arm phase I/II trial evaluating the combination of 223Ra and [177Lu]Lu-PSMA-I&T in men with mCRPC. Thirty-six patients will receive 7.4 GBq of [177Lu]Lu-PSMA-I&T, concurrently with 223Ra in escalating doses (28 kBq/kg - 55kBq/kg), both given intravenously every six weeks for up to six cycles. Eligible patients will have at least two untreated bone metastases visible on bone scintigraphy, and PSMA-positive disease on PSMA PET scan. Patients must have adequate bone marrow and organ function and be willing to undergo tumor biopsies. Patients with discordant disease visible on FDG PET scan (defined as FDG positive disease with minimal or no PSMA expression and no uptake on bone scan) will be excluded. Other key exclusion criteria include the presence of diffuse marrow disease, prior treatment with 223Ra or [177Lu]Lu-PSMA, or more than one prior line of chemotherapy for prostate cancer. The co-primary objectives of this study are to determine the maximum tolerated dose of 223Ra when combined with [177Lu]Lu-PSMA-I&T and the 50% PSA response rate. Conclusion: The AlphaBet trial is a phase I/II study combining 223Ra with [177Lu]Lu-PSMA-I&T in patients with mCRPC. We aim to enroll the first patient in Q3 2022, and recruitment is anticipated to continue for 24 months. Study registration: NCT05383079.

Estrogen-induced immune changes within the normal mammary gland.

Breast cancer (BCa) incidence increases following aberrant hormone exposure, which has been linked to direct effects on estrogen receptor (ER)+ mammary epithelium. While estrogen exposure during mammary involution has been shown to drive tumour growth via neutrophils, the potential for the ER + immune microenvironment to mediate part (in addition to mammary epithelial cells) of hormonally controlled BCa risk during normal development has not been assessed. We collected mammary tissue, lymph nodes and blood from tumour naïve mice treated with, oophorectomy, estrogen (17ß estradiol) or Fulvestrant. Flow cytometry was used to examine the impact on the frequency of innate and adaptive immune cells. Oophorectomy and fulvestrant decreased the proportion of macrophages, particularly pro-tumour polarized M2 macrophages and neutrophils. Conversely, dendritic cells were increased by these therapies, as were eosinophils. Estrogen increased the proportion of M2 macrophages and to a lesser extent CD4-CD8- double negative and FoxP3+ regulatory T cells but decreased CD8 + T cells and B cells. Excluding eosinophils, these changes were restricted to the mammary tissue. This suggests that inhibiting estrogen action lowers the immune suppressive myeloid cells, increases in antigen presentation and eosinophil-mediated direct or indirect cytotoxic effects. In contrast, estrogen exposure, which drives BCa risk, increases the suppressive myeloid cells and reduces anti-tumour cytotoxic T cells. The impact of hormonal exposure on BCa risk, may in part be linked to its immune modulatory activity.

DNA barcoding reveals ongoing immunoediting of clonal cancer populations during metastatic progression and immunotherapy response.

Cancers evade the immune system through the process of cancer immunoediting. While immune checkpoint inhibitors are effective for reactivating tumour immunity in some cancer types, many other solid cancers, including breast cancer, remain largely non-responsive. Understanding how non-responsive cancers evade immunity and whether this occurs at the clonal level will improve immunotherapeutic design. Here we use DNA barcoding to track murine mammary cancer cell clones during immunoediting and determine clonal transcriptional profiles that allow immune evasion following anti-PD1 plus anti-CTLA4 immunotherapy. Clonal diversity is significantly restricted by immunotherapy treatment in both primary tumours and metastases, demonstrating selection for pre-existing breast cancer cell populations and ongoing immunoediting during metastasis and treatment. Immunotherapy resistant clones express a common gene signature associated with poor survival of basal-like breast cancer patient cohorts. At least one of these genes has an existing small molecule that can potentially be used to improve immunotherapy response.

Potent Stimulation of the Androgen Receptor Instigates a Viral Mimicry Response in Prostate Cancer.

Inhibiting the androgen receptor (AR), a ligand-activated transcription factor, with androgen deprivation therapy is a standard-of-care treatment for metastatic prostate cancer. Paradoxically, activation of AR can also inhibit the growth of prostate cancer in some patients and experimental systems, but the mechanisms underlying this phenomenon are poorly understood. This study exploited a potent synthetic androgen, methyltestosterone (MeT), to investigate AR agonist-induced growth inhibition. MeT strongly inhibited growth of prostate cancer cells expressing AR, but not AR-negative models. Genes and pathways regulated by MeT were highly analogous to those regulated by DHT, although MeT induced a quantitatively greater androgenic response in prostate cancer cells. MeT potently downregulated DNA methyltransferases, leading to global DNA hypomethylation. These epigenomic changes were associated with dysregulation of transposable element expression, including upregulation of endogenous retrovirus (ERV) transcripts after sustained MeT treatment. Increased ERV expression led to accumulation of double-stranded RNA and a "viral mimicry" response characterized by activation of IFN signaling, upregulation of MHC class I molecules, and enhanced recognition of murine prostate cancer cells by CD8+ T cells. Positive associations between AR activity and ERVs/antiviral pathways were evident in patient transcriptomic data, supporting the clinical relevance of our findings. Collectively, our study reveals that the potent androgen MeT can increase the immunogenicity of prostate cancer cells via a viral mimicry response, a finding that has potential implications for the development of strategies to sensitize this cancer type to immunotherapies. Significance: Our study demonstrates that potent androgen stimulation of prostate cancer cells can elicit a viral mimicry response, resulting in enhanced IFN signaling. This finding may have implications for the development of strategies to sensitize prostate cancer to immunotherapies.

Examining the Preliminary Effectiveness and Acceptability of a Web-Based Training Program for Australian Secondary School Teachers: Pilot Study of the BEAM (Building Educators' Skills in Adolescent Mental Health) Program.

BACKGROUND: Secondary schools are increasingly supporting adolescents' mental health and well-being, yet many teachers report that they lack the skills and confidence to do so. Building Educators' skills in Adolescent Mental Health (BEAM) is a web-based training program developed to improve secondary school teachers' knowledge and confidence in caring for students' mental health. OBJECTIVE: This pilot study examined the preliminary effectiveness and acceptability of the BEAM program for improving mental health knowledge, attitudes, confidence, helping behaviors, and psychological distress among secondary school teachers. METHODS: A single-arm pilot trial was conducted from July to December 2019 among secondary school teachers located in New South Wales, Australia, who were employed in leadership positions responsible for managing student well-being (ie, Year Advisors). Participants had access to the BEAM program for 6 weeks. Self-report surveys, delivered at baseline, postintervention (6-weeks post baseline) and 3-month follow-up (19 weeks post baseline) were used to measure changes in training outcomes. Acceptability was assessed by program use, barriers, satisfaction, and participants' perceptions of program effectiveness. RESULTS: A total of 70 secondary school teachers took part (mean age 36.5 years, SD 9.41 years, range 24-60 years). Significant improvements in confidence were reported at postintervention and 3-month follow-up. Significant improvements in helping behaviors were reported at 3-month follow-up only. There was also a significant reduction in psychological distress at postintervention. Participants agreed that the program content was easy to understand and relevant, but program completion was challenged by lack of time, competing priorities, and forgetfulness. CONCLUSIONS: Findings indicated that a web-based training program may be beneficial for improving secondary school teachers' abilities to care for students' mental health; however, program modifications are required to increase training completions. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12619000821190, Universal Trial Number U1111-1232-7680; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377529.

Colorimetric histology using plasmonically active microscope slides.

The human eye can distinguish as many as 10,000 different colours but is far less sensitive to variations in intensity1, meaning that colour is highly desirable when interpreting images. However, most biological samples are essentially transparent, and nearly invisible when viewed using a standard optical microscope2. It is therefore highly desirable to be able to produce coloured images without needing to add any stains or dyes, which can alter the sample properties. Here we demonstrate that colorimetric histology images can be generated using full-sized plasmonically active microscope slides. These slides translate subtle changes in the dielectric constant into striking colour contrast when samples are placed upon them. We demonstrate the biomedical potential of this technique, which we term histoplasmonics, by distinguishing neoplastic cells from normal breast epithelium during the earliest stages of tumorigenesis in the mouse MMTV-PyMT mammary tumour model. We then apply this method to human diagnostic tissue and validate its utility in distinguishing normal epithelium, usual ductal hyperplasia, and early-stage breast cancer (ductal carcinoma in situ). The colorimetric output of the image pixels is compared to conventional histopathology. The results we report here support the hypothesis that histoplasmonics can be used as a novel alternative or adjunct to general staining. The widespread availability of this technique and its incorporation into standard laboratory workflows may prove transformative for applications extending well beyond tissue diagnostics. This work also highlights opportunities for improvements to digital pathology that have yet to be explored.

A cluster randomised controlled trial of a web-based youth mental health service in Australian schools.

BACKGROUND: Secondary schools have attempted to address gaps in help-seeking for mental health problems with little success. This trial evaluated the effectiveness of a universal web-based service (Smooth Sailing) for improving help-seeking intentions for mental health problems and other related outcomes among students. METHODS: A cluster randomised controlled trial was conducted to evaluate the 12-week outcomes of the Smooth Sailing service among 1841 students from 22 secondary schools in New South Wales, Australia. Assignment was conducted at the school level. The control condition received school-as-usual. The primary outcome was help-seeking intentions for general mental health problems at 12-weeks post-baseline. Secondary outcomes included help-seeking behaviour, anxiety and depressive symptoms, psychological distress, psychological barriers to help-seeking, and mental health literacy. Data were analysed using mixed linear models. This trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12618001539224). FINDINGS: At 12-weeks post-baseline, there was a marginal statistical difference in the relative means of help-seeking intentions (effect size=0•10, 95%CI: -0•02-0•21) that favoured the intervention condition. Help-seeking from adults declined in both conditions. There was a greater reduction in the number of students who "needed support for their mental health but were not seeking help" in the intervention condition (OR: 2•08, 95%CI: 1•72-2.27, P<•0001). No other universal effects were found. Participants found the service easy to use and understand; However, low motivation, time, forgetfulness, and lack of perceived need were barriers to use. INTERPRETATION: Smooth Sailing led to small improvements in help-seeking intentions. Refinements are needed to improve its effectiveness on other mental health outcomes and to increase student uptake and engagement. FUNDING: HSBC and Graf Foundation.

Oral administration of bovine milk-derived extracellular vesicles induces senescence in the primary tumor but accelerates cancer metastasis.

The concept that extracellular vesicles (EVs) from the diet can be absorbed by the intestinal tract of the consuming organism, be bioavailable in various organs, and in-turn exert phenotypic changes is highly debatable. Here, we isolate EVs from both raw and commercial bovine milk and characterize them by electron microscopy, nanoparticle tracking analysis, western blotting, quantitative proteomics and small RNA sequencing analysis. Orally administered bovine milk-derived EVs survive the harsh degrading conditions of the gut, in mice, and is subsequently detected in multiple organs. Milk-derived EVs orally administered to mice implanted with colorectal and breast cancer cells reduce the primary tumor burden. Intriguingly, despite the reduction in primary tumor growth, milk-derived EVs accelerate metastasis in breast and pancreatic cancer mouse models. Proteomic and biochemical analysis reveal the induction of senescence and epithelial-to-mesenchymal transition in cancer cells upon treatment with milk-derived EVs. Timing of EV administration is critical as oral administration after resection of the primary tumor reverses the pro-metastatic effects of milk-derived EVs in breast cancer models. Taken together, our study provides context-based and opposing roles of milk-derived EVs as metastasis inducers and suppressors.

Tumor microenvironmental cytokines bound to cancer exosomes determine uptake by cytokine receptor-expressing cells and biodistribution.

Metastatic spread of a cancer to secondary sites is a coordinated, non-random process. Cancer cell-secreted vesicles, especially exosomes, have recently been implicated in the guidance of metastatic dissemination, with specific surface composition determining some aspects of organ-specific localization. Nevertheless, whether the tumor microenvironment influences exosome biodistribution has yet to be investigated. Here, we show that microenvironmental cytokines, particularly CCL2, decorate cancer exosomes via binding to surface glycosaminoglycan side chains of proteoglycans, causing exosome accumulation in specific cell subsets and organs. Exosome retention results in changes in the immune landscape within these organs, coupled with a higher metastatic burden. Strikingly, CCL2-decorated exosomes are directed to a subset of cells that express the CCL2 receptor CCR2, demonstrating that exosome-bound cytokines are a crucial determinant of exosome-cell interactions. In addition to the finding that cytokine-conjugated exosomes are detected in the blood of cancer patients, we discovered that healthy subjects derived exosomes are also associated with cytokines. Although displaying a different profile from exosomes isolated from cancer patients, it further indicates that specific combinations of cytokines bound to exosomes could likewise affect other physiological and disease settings.

High-content siRNA 3D co-cultures to identify myoepithelial cell-derived breast cancer suppressor proteins.

Understanding how cancer cells interact with the surrounding microenvironment early in breast cancer development can provide insight into the initiation and progression of invasive breast cancers. The myoepithelial cell layer surrounding breast ducts acts as a physical barrier in early breast cancer, preventing cancer cells from invading the surrounding stroma. Changes to the expression profile and properties of myoepithelial cells have been implicated in progression to invasive carcinoma. Identifying the molecular drivers of myoepithelial cell-mediated tumour suppression may offer new approaches to predict and block the earliest stages of cancer invasion. We employed a high-content approach to knock down 87 different genes using siRNA in an immortalised myoepithelial cell line, prior to co-culture with invasive breast cancer cells in 3D. Combined with high-content imaging and a customised analysis pipeline, this system was used to identify myoepithelial proteins that are necessary to control cancer cell invasion. This dataset has identified prospective myoepithelial suppressors of early breast cancer invasion which may be used by researchers to investigate their clinical validity and utility.

The Building Educators' Skills in Adolescent Mental Health Training Program for Secondary School Educators: Protocol for a Cluster Randomized Controlled Trial.

BACKGROUND: In Australia, secondary school educators are well positioned to recognize mental illness among students and provide support. However, many report that they lack the knowledge and confidence to do so, and few mental health training programs available for educators are evidence based. To address this gap, the Black Dog Institute (BDI) developed a web-based training program (Building Educators' Skills in Adolescent Mental Health [BEAM]) that aims to improve mental health knowledge, confidence, and helping behaviors among secondary school educators in leadership positions. A pilot study of the training program found it to be positively associated with increased confidence and helping behaviors among educators and reduced personal psychological distress. An adequately powered randomized controlled trial (RCT) is needed. OBJECTIVE: The primary objective of this cluster RCT is to evaluate the effectiveness of the BEAM program for improving educators' confidence in managing student mental health. The trial will also evaluate the effect of the BEAM program in increasing educators' frequency of providing help to students and improving their mental health knowledge and reducing educators' psychological distress and stigma toward students with mental health issues. METHODS: The target sample size is 234 educators from 47 secondary schools across New South Wales, Australia. Four waves of recruitment and enrollment into the trial are planned. Schools will participate in one wave only and will be randomized to the intervention or waitlist control conditions. Participants from the same school will be assigned to the same condition. Assessments will be conducted at baseline, posttest (10 weeks after baseline), and follow-up (22 weeks after baseline) using the BDI eHealth research platform. Intervention participants will receive access to the BEAM program for 10 weeks upon completion of baseline, and the control condition will receive access for 10 weeks upon completion of the follow-up assessment. RESULTS: Recruitment for this trial began on July 21, 2020, with the first baseline assessments occurring on August 17, 2020. To date, 295 participants from 71 schools have completed baseline. Due to the unexpected success of recruitment in the first 3 waves, the final fourth wave has been abandoned. Intervention participants are currently receiving the program, with follow-up due for completion in March 2021. CONCLUSIONS: This is one of the first RCTs to examine the effectiveness of a web-based adolescent mental health training program for Australian secondary school educators in leadership positions. If found to be effective, this training program will offer a sustainable and scalable delivery method for upskilling educators in caring for students' mental health. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12620000876998; https://covid-19.cochrane.org/studies/crs-14669208. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/25870.

Loss of type I IFN responsiveness impairs natural killer cell antitumor activity in breast cancer.

Competent type I IFN signaling is the lynchpin of most immune surveillance mechanisms and has recently proven critical to the efficacy of several anticancer agents. Expression of the type I IFN receptor, IFNAR, underpins type I IFN responsiveness in all cells and facilitates the activation and cytotoxic potential of lymphocytes, while loss of IFNAR on lymphocytes has previously been associated with tumor progression and poor patient survival. This study underscores the importance of intact type I IFN signaling to NK cells in the regulation of tumorigenesis and metastasis, whereby ablation of NK cell IFNAR1 impairs antitumor activity and tumor clearance. Using a preclinical model of triple negative breast cancer, we identified that intact IFNAR on NK cells is required for an effective response to type I IFN-inducing immunotherapeutics that may be mediated by pathways associated with NK cell degranulation. Taken together, these data provide a rationale for considering the IFNAR status on NK cells when devising therapeutic strategies aimed at inducing systemic type I IFN signaling in breast cancer.

A switch in mechanism of action prevents doxorubicin-mediated cardiac damage.

Cancer patients treated with doxorubicin are at risk of congestive heart failure due to doxorubicin-mediated cardiotoxicity via topoisomerase IIß poisoning. Acute cardiac muscle damage occurs in response to the very first dose of doxorubicin, however, cardioprotection has been reported after co-treatment of doxorubicin with acyloxyalkyl ester prodrugs. The aim of this study was to examine the role played by various forms of acute cardiac damage mediated by doxorubicin and determine a mechanism for the cardioprotective effect of formaldehyde-releasing prodrug AN-9 (pivaloyloxymethyl butyrate). Doxorubicin-induced cardiac damage in BALB/c mice bearing mammary tumours was established with a single dose of doxorubicin (4 or 16 mg/kg) administered alone or in combination with AN-9 (100 mg/kg). AN-9 protected the heart from doxorubicin-induced myocardial apoptosis and also significantly reduced dsDNA breaks, independent from the level of doxorubicin biodistribution to the heart. Covalent incorporation of [14C]doxorubicin into DNA showed that the combination treatment yielded significantly higher levels of formaldehyde-mediated doxorubicin-DNA adducts compared to doxorubicin alone, yet this form of damage was associated with cardioprotection from apoptosis. The cardiac transcriptomic analysis indicates that the combination treatment initiates inflammatory response signalling pathways. Doxorubicin and AN-9 combination treatments were cardioprotective, yet preserved doxorubicin-mediated anti-tumour proliferation and apoptosis in mammary tumours. This was associated with a switch in doxorubicin action from cardiac topoisomerase IIß poisoning to covalent-DNA adduct formation. Co-administration of doxorubicin and formaldehyde-releasing prodrugs, such as AN-9, may be a promising cardioprotective therapy while maintaining doxorubicin activity in primary mammary tumours.

Intratumoral administration of the Toll-like receptor 7/8 agonist 3M-052 enhances interferon-driven tumor immunogenicity and suppresses metastatic spread in preclinical triple-negative breast cancer.

OBJECTIVES: Loss of tumor-inherent type I interferon (IFN) signalling has been closely linked to accelerated metastatic progression via decreased immunogenicity and antitumor immunity. Previous studies in murine models of triple-negative breast cancer (TNBC) demonstrate that systemic IFN inducers are effective antimetastatic agents, via sustained antitumor CD8+ T-cell responses. Repeated systemic dosing with recombinant IFNs or IFN inducers is associated with significant toxicities; hence, the use of alternate intratumoral agents is an active area of investigation. It is critical to investigate the impact of intratumoral agents on subsequent metastatic spread to predict clinical impact. METHODS: In this study, the local and systemic impact of the intratumoral Toll-like receptor (TLR) 7/8 agonist 3M-052 alone or in combination with anti-PD1 was evaluated in metastatic TNBC models. The IFN-α receptor (IFNAR1) blocking antibody, MAR1-5A3, along with immune-deficient mice and ex vivo assays are utilised to examine the key targets of this agent that are critical for an antimetastatic response. RESULTS: Single intratumoral administration of 3M-052 reduced mammary tumor growth, induced a T-cell-inflamed tumor microenvironment (TME) and reduced metastatic spread to lung. Metastasis suppression was reliant on IFN signalling and an antitumor immune response, in contrast to primary tumor growth inhibition, which was retained in NSG and CD8+ T-cell-depleted mice. 3M-052 action was demonstrated via dendritic cell activation and production of type I IFN and other pro-inflammatory cytokines to initiate a T-cell-inflamed TME and promote tumor cell antigen presentation. CONCLUSION: This work supports neoadjuvant TLR agonist-based immunotherapeutics as realistic options for immune activation in the TME and long-term metastatic protection in TNBC.

Preliminary study highlights the potential of immune checkpoint inhibitors in sarcomatoid mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is well known as an aggressive disease with poor survival. This has sparked trials of alternate immune-based therapies in MPM. While up to a quarter of MPM patients respond to immune checkpoint inhibitors (ICIs), predicting response remains challenging and PD-L1 expression alone has been deemed insufficient. Additionally, patients with sarcomatoid MPM are often excluded from trials utilizing ICIs due to their rapid progression. Here, we analyze the association of T lymphocytes with response to ICI-based immunotherapy to uncover predictive immune markers across subtypes. METHODS: Retrospective analysis of immunotherapy treated mesothelioma patient cohorts from two sites were pooled. Patient characteristics, including age, sex, subtype and previous treatment were captured. Multiplex immunohistochemistry was used to assess proportions of CD4, CD8, CD45RO and FOXP3 positive infiltrates in MPM and their association with progression free (PFS) and overall (OS) survival post immunotherapy. RESULTS: Samples derived from 22 patients were analyzed; 13 (59%) had epithelioid MPM, 6 (27%) sarcomatoid and 3 (14%) biphasic. The overall ICI response rate was 40%, with a median PFS (mPFS) and OS (mOS) of 3.8 and 11.17 months, respectively. Of the subtypes, sarcomatoid patients displayed the greatest median PFS and OS (>28 months) post ICI compared to the epithelioid subtype (3 and 11 months respectively), which correlated with higher proportions of infiltrating CD8+, CD45RO+ and CD8+CD45RO+ cells. Patients who received ICIs as first-line therapy had greater PFS than those who received it as second or third line post-chemotherapy. CONCLUSIONS: High proportions of T lymphocytes and CD45RO+ cells were associated with prolonged mPFS and mOS in sarcomatoid patients treated with ICI immunotherapy. These data support the expansion of trials utilizing single and combination ICIs as first-line therapy in sarcomatoid MPM and warrants further studies testing the impact or detriment of chemotherapy pre-ICI.

A randomised controlled trial of a relationship-focussed mobile phone application for improving adolescents' mental health.

BACKGROUND: This study evaluated the acceptability and effectiveness of a relationship-focussed mobile phone application (WeClick) for improving depressive symptoms and other mental health outcomes in adolescents. METHODS: A randomised controlled trial involving 193 youth (M age: 14.82, SD: 0.94, 86.5% female) from Australia was conducted. Youth were recruited via the Internet and randomly allocated to the intervention or a 4-week wait list control condition, stratified for age and gender. The primary outcome was change in depressive symptom scores measured using the Patient Health Questionnaire for Adolescents (PHQ-A) at baseline, 4-week post-test and 12-week follow-up. Secondary outcomes included anxiety, psychological distress, wellbeing, help-seeking intentions for mental health, social self-efficacy and social support. Participants in the intervention condition received access to the intervention for four weeks. Thematic analysis was utilised to identify and examine acceptability. RESULTS: The change in PHQ-A scores from baseline to 4-week post-test did not differ significantly (d = 0.26, p = .138) between the intervention (Mchange = -2.9, SD = 5.3) and wait list control conditions (Mchange = -1.7, SD = 4.3). However, significant between-group improvements were observed in wellbeing (d = 0.37, p = .023), help-seeking intentions (d = 0.36, p = .016) and professional help-seeking intentions for mental health problems (d = 0.36, p = .008). Increases in help-seeking intentions were sustained at follow-up in the intervention condition. No differential effects were found for generalised anxiety, separation anxiety, social self-efficacy or for any social support outcomes. Over 90% of participants indicated the app was enjoyable, interesting and easy to use. The app provided 'advice and direction' (n = 42; 46.15%), an 'opportunity for self-reflection' (n = 33; 36.3%) and 'normalised experiences' (n = 21; 23.1%). CONCLUSIONS: The WeClick app was found to be effective for improving wellbeing and help-seeking intentions for mental health in adolescents. A larger, adequately powered trial is now required to establish differential effects on depressive symptoms. This trial was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12618001982202.

Adherence to e-mental health among youth: Considerations for intervention development and research design.

E-mental health programmes have great potential to provide young people with access to mental health support. However, it is commonly reported that adherence to these programmes is low. Low adherence can be problematic, particularly if young people do not receive the full benefits of a programme. In a research trial setting, non-adherence to treatment recommendations can prevent researchers from drawing strong conclusions about effectiveness. Although adherence has been recognised as an issue in need of attention, many of the reviews available are focused on adults and lack clear direction towards what strategies to employ. This paper presents a broad review of the adherence literature, focusing on factors associated with improving adherence to e-mental health among youth. Our view on the key elements to improve adherence identified from the existing literature are presented, and key recommendations for e-mental health intervention design are provided. These include: developing and communicating adherence guidelines based on individuals' needs and symptom severity, including customisable features to provide a tailored experience and promote a sense of agency, including engagement checks and adopting a user-centred approach by utilising strategies such as co-design. This paper provides guidance to intervention designers and researchers by outlining recommendations and considerations for intervention development and research design.