Hear my voice: understanding how community health workers in the Peruvian Amazon expanded their roles to mitigate the impact of the COVID-19 pandemic through community-based participatory research.

INTRODUCTION: The COVID-19 pandemic led to the collapse of the Peruvian health system, disrupting healthcare access for indigenous communities in the Amazon. Our study analysed how community health workers (CHWs) from indigenous communities in the Peruvian Amazon expanded their roles to mitigate the effects of the COVID-19 pandemic. METHODS: Fourteen CHWs from Loreto, Peru, participated in a community-based participatory research project using Photovoice, a technique encouraging vulnerable groups to take photos and develop stories illustrating their lived experiences. Participants were recruited from Mamás del Río, a local university-based programme, through purposive sampling. CHWs were asked to photograph how the pandemic affected their lives and work. Participants met four times over 5 months to share photos and develop action items. Data were organised into key themes using thematic analysis. CHWs shared photo galleries with policy-makers in Loreto and Lima. RESULTS: CHWs produced 36 photos with 33 texts highlighting their roles during COVID-19. Three core themes emerged: the (1) collapse of health infrastructure, (2) use of medicinal plants versus pharmaceuticals and (3) community adaptations and struggles. The leadership of CHWs emerged as a cross-cutting theme as CHWs supported COVID-19 efforts without government training or resources. CHWs asked policy-makers for formal integration into the health system, standardisation of training and management of community pharmacies. CONCLUSION: CHWs demonstrated their leadership and expanded their roles during the pandemic with little to no training from the government. Global investment in robust CHW programmes can fortify healthcare delivery.

TACkling Cancer by Targeting Selective Protein Degradation.

Targeted protein degradation has emerged as an alternative therapy against cancer, offering several advantages over traditional inhibitors. The new degrader drugs provide different therapeutic strategies: they could cross the phospholipid bilayer membrane by the addition of specific moieties to extracellular proteins. On the other hand, they could efficiently improve the degradation process by the generation of a ternary complex structure of an E3 ligase. Herein, we review the current trends in the use of TAC-based technologies (TACnologies), such as PROteolysis TArgeting Chimeras (PROTAC), PHOtochemically TArgeting Chimeras (PHOTAC), CLIck-formed Proteolysis TArgeting Chimeras (CLIPTAC), AUtophagy TArgeting Chimeras (AUTAC), AuTophagosome TEthering Compounds (ATTEC), LYsosome-TArgeting Chimeras (LYTAC), and DeUBiquitinase TArgeting Chimeras (DUBTAC), in experimental development and their progress towards clinical applications.

Addressing knowledge gaps: the key role of community health workers and healthcare providers in human papillomavirus prevention and vaccine uptake in a border community.

The Human Papillomavirus (HPV) is the most common sexually transmitted infection and nearly every person who is sexually active will get HPV at some point in their lifetime without having the HPV vaccine. Healthcare Providers (HCPs) and Community Health Workers (CHWs) play an essential role in promoting the HPV vaccine and providing education about HPV in communities. Three focus groups with CHWs (n = 17) and HCPs (n = 7) were conducted and led by trained facilitators. In addition to participating in the focus group, CHWs and HCPs completed a brief questionnaire. Focus groups were voice recorded and transcribed for qualitative analysis. Independent coders conducted content analysis to identify the salient themes of the focus groups. Several important findings emerged from this study highlighting the barriers to HPV knowledge, gaps in the self-perceived role of HPV cancer prevention, and opportunities to action. Financial, knowledge, patriarchy, behaviors, attitudes, and fears were identified as the perceived patient-related barriers to promoting HPV cancer prevention. Both CHWs and HCPs explained that their female patients are often discouraged by their husbands from seeking out sexual health-related healthcare. Finding suggest the need for community tailored education on HPV and "best practice" trainings for HPV prevention that is applicable to both CHWs and HCPs.

Hispanic Survivors and Caregivers of Human Papillomavirus-Associated Cancers: Lived Experiences in a U.S.-Mexico Border Community.

Although human papillomavirus (HPV)-associated cancers are preventable and treatable at early stages, health disparities in HPV-associated cancer outcomes continue to exist among Hispanic populations. Hispanics residing along the U.S.-Mexico border face barriers distinct from other geographically dispersed populations within the United States. The current research aimed to explore perspectives and lived experiences of survivors and caregivers of HPV-associated cancers in El Paso, Texas, to inform intervention development and health practices to increase preventive services among populations residing on the U.S.-Mexico border region. A mixed-method approach was employed using a semi-structured interview guide with Quality of Life (QOL) scales with (N = 29) survivors and caregivers of HPV-associated cancers. Content analysis was used to extract themes and descriptive statistics were reported for quality of life. Five major themes were identified: (1) barriers to preventive services and treatment; (2) role of health care providers in diagnosis and care; (3) treatment challenges, support systems, and challenges associated with caregiving; and (4) HPV prevention and health recommendations from survivors and caregivers. Finally, given the context of the COVID-19 pandemic, an additional theme was explored on accessibility to health and human services. QOL scales suggested better overall physical health and spiritual well-being in survivors and fear of reoccurrence among caregivers and survivors. The current research highlights the role of health care providers and human service professionals in the promotion of health practices of at-risk populations by increasing health literacy among cancer patients and caregivers, and exploring experiences, challenges, and messages caregivers and survivors had regarding HPV prevention.

Food and housing security at a US Hispanic-Serving Institution: An examination before and during the COVID-19 pandemic.

University students occupy a socially marginal position and therefore are often underserved by academic and service institutions. This article analyzes food and housing security among students at The University of Texas at El Paso, a Hispanic-Serving Institution located in the U.S.-Mexico Border region. Findings of a sample of n = 7,633 university students are presented in the first cross-sectional, two-year food and housing security study on campus administered via platform Campus Labs Baseline. The first sample in 2019 consisted of n = 2,615 students representing 10.4% of student enrollment (25,177 total 2019 enrollment), and the second sample in 2020 was n = 5,018 representing 20.2% of student enrollment (24,879 total 2020 enrollment). To measure food security, the six-item short form of the U.S. Department of Agriculture (USDA) Household Food Security Survey Module was used. To document housing security, we created questions informed by student input. In this study, survey results are reported, and tests are conducted to assess the relationships between various student characteristics and food and housing security. Student characteristics significantly impacting food and housing security are probed further using data visualizations and subpopulation analysis with a focus on analyzing factors impacted by the COVID-19 pandemic. Results indicate that employment status, consistent employment status, hours per week, academic level, number of dependents, and gender are all factors associated with food security during the pandemic but not prior to the pandemic. Other factors, including, college affiliation, ethnicity/race, having any dependents and being head of household, living alone, mode of campus transportation and mode of the transportation, household income, and age, all were associated with food security in both academic years. Using these results, a critical analysis of past interventions addressing food and housing security is presented with a focus on changes made during the pandemic. Recommendations are made for further data-driven interventions and future steps.

The Use of Photovoice Methodology to Assess Health Needs and Identify Opportunities Among Migrant Transgender Women in the U.S.-Mexico Border.

Psychosocial, social and structural conditions have rarely been studied among transgender women in the U.S.-Mexico Border. This study used Photovoice methodology to empower migrant transgender women of color (TWC) to reflect on realities from their own perspectives and experiences and promote critical dialogue, knowledge, and community action. Sixteen participants documented their daily experiences through photography, engaged in photo-discussions to assess needs and identify opportunities, and developed a community-informed Call to Action. Four major themes emerged from the participants' photographs, discussions, and engagement: (1) mental health, (2) migration experiences and challenges, (3) stigma, discrimination, and resiliency, and (4) impact of the COVID-19 pandemic. Through active community engagement, a Call to Action was developed. A binational advisory committee of decision makers and scholars reviewed a set of recommendations to better respond to the needs of TWC in the U.S.-Mexico Border. Photovoice served as an empowerment tool for TWC to assess the myriad of syndemic conditions, including mental health, stigma, discrimination and COVID-19, affecting them daily and identify initiatives for change.

Antitumoral Activity of a CDK9 PROTAC Compound in HER2-Positive Breast Cancer.

Cyclin-dependent kinases (CDKs) are a broad family of proteins involved in the cell cycle and transcriptional regulation. In this article, we explore the antitumoral activity of a novel proteolysis-targeting chimera (PROTAC) compound against CDK9. Breast cancer cell lines from different subtypes were used. Transcriptomic mapping of CDKs in breast cancer demonstrated that the expression of CDK9 predicted a detrimental outcome in basal-like tumors (HR = 1.51, CI = 1.08-2.11, p = 0.015) and, particularly, in the luminal B subtype with HER2+ expression (HR = 1.82, CI = 1.17-2.82, p = 0.0069). The novel CDK9 PROTAC, THAL-SNS-032, displayed a profound inhibitory activity in MCF7, T47D, and BT474 cells, with less effect in SKBR3, HCC1569, HCC1954, MDA-MB-231, HS578T, and BT549 cells. The three cell lines with HER2 overexpression and no presence of ER, SKBR3, HCC1569, and HCC1954 displayed an EC50 three times higher compared to ER-positive and dual ER/HER2-positive cell lines. BT474-derived trastuzumab-resistant cell lines displayed a particular sensitivity to THAL-SNS-032. Western blot analyses showed that THAL-SNS-032 caused a decrease in CDK9 levels in BT474, BT474-RH, and BT474-TDM1R cells, and a significant increase in apoptosis. Experiments in animals demonstrated an inverse therapeutic index of THAL-SNS-032, with doses in the nontherapeutic and toxic range. The identified toxicity was mainly due to an on-target off-tumor effect of the compound in the gastrointestinal epithelium. In summary, the potent and efficient antitumoral properties of the CDK9 PROTAC THAL-SNS-032 opens the possibility of using this type of compound in breast cancer only if specifically delivered to cancer cells, particularly in ER/HER2-positive and HER2-resistant tumors.

Analysis of Cancer Knowledge, Attitudes, and Practices in Adolescents and Young Adults in Two Texas Rural Communities.

The Youth and Young Adults Cancer Knowledge Attitudes and Practices (C-KAP) exploratory study in 2 rural underserved areas in a border community. C-KAP is an interdisciplinary research pilot project led by university scholars in psychology and social work in partnership with community partners. The exploratory cross-sectional mix-method study recruited 141 (n=141) youth and young adults (ages 18-39). This study was informed on empirical research and a bilingual online questionnaire was field-tested, and data was collected via QuestionPro Software. Quantitative analysis was conducted using SPSS version 27. Descriptive statistics and frequency analysis were used for demographics and basic statistics. Chi square tests and Fisher's exact tests between variables were ran to find statistically significant associations. For the qualitative data, independent coders conducted recurrent content analysis to identify themes. Salient themes include knowledge about cancer types; access to health care; prevention; and the perceived impact of COVID-19 pandemic. Findings highlight a lack of knowledge and orientation on cancer in youth and young adults suggesting the need for community tailored education and screening interventions. Other findings reflect gender differences in knowledge and practices, which indicates that a gender-specific lens is needed when delivering education.

The Impact of Restrictive Policies on Mexican Immigrant Parents and Their Children's Access to Health Care.

Background: This study assessed whether policies that limit Mexican immigrants' access to care affects their children's access to a regular source of care, health insurance, and timely preventive health visits. Method: This was a cross-sectional study among Mexican immigrant parents who attended a health promotion program in Texas, Nevada, New York, and Illinois. A sociodemographic survey, including parental and child variables, was administered. Results: Children of parents without health insurance were almost four times more likely to be uninsured and eight times more likely to lack a regular source of care. Children of parents without a regular source of care were less than half as likely to have their own regular source of care than children whose parents had a regular source of care. Discussion: Findings suggest when parents are uninsured/lack a regular source of care, a child's health disparity is created. Reducing disparities in health care coverage, affecting foreign-born parents, positively impacts their children's access to care. Clinical Trial Registration number: NCT03209713.

Genomic Correlates of DNA Damage in Breast Cancer Subtypes.

Among the described druggable vulnerabilities, acting on the DNA repair mechanism has gained momentum, with the approval of PARP inhibitors in several indications, including breast cancer. However, beyond the mere presence of BRCA1/BRCA2 mutations, the identification of additional biomarkers that would help to select tumors with an extreme dependence on DNA repair machinery would help to stratify therapeutic decisions. Gene set enrichment analyses (GSEA) using public datasets evaluating expression values between normal breast tissue and breast cancer identified a set of upregulated genes. Genes included in different pathways, such as ATM/ATR, BARD1, and Fanconi Anemia, which are involved in the DNA damage response, were selected and confirmed using molecular alterations data contained at cBioportal. Nineteen genes from these gene sets were identified to be amplified and upregulated in breast cancer but only five of them NBN, PRKDC, RFWD2, UBE2T, and YWHAZ meet criteria in all breast cancer molecular subtypes. Correlation of the selected genes with prognosis (relapse free survival, RFS, and overall survival, OS) was performed using the KM Plotter Online Tool. In last place, we selected the best signature of genes within this process whose upregulation can be indicative of a more aggressive phenotype and linked with worse outcome. In summary, we identify genomic correlates within DNA damage pathway associated with prognosis in breast cancer.

Photovoice: Integrating Course-Based Research in Undergraduate and Graduate Social Work Education.

Research skills are vital to students' professional careers and must be cultivated in the social work curriculum. While students and faculty may hesitate to participate in a course-based research project, the authors believe that the Photovoice method is easily adapted to a variety of class and student needs. Photovoice is a field-oriented and qualitative research method that visually documents and communicates community assets and needs. The first purpose of this article is to offer Photovoice as a potential model for instructors to implement a course-based research project. The second purpose is to quantitatively assess changes in students' reported confidence in social work topics and research activities. Data revealed that the students reported increased confidence in the majority of the content and research evaluated; content examples include economic justice and determinants of social inequalities; research examples include analysing data for patterns and identifying the limitations of research methods. The data illustrate the pedagogical power of Photovoice.

Pathogenic Microenvironment from Diabetic-Obese Visceral and Subcutaneous Adipocytes Activating Differentiation of Human Healthy Preadipocytes Increases Intracellular Fat, Effect of the Apocarotenoid Crocetin.

In diabetes mellitus type 2 (DM2), developed obesity is referred to as diabesity. Implementation of a healthy diet, such as the Mediterranean, prevents diabesity. Saffron is frequently used in this diet because of its bioactive components, such as crocetin (CCT), exhibit healthful properties. It is well known that obesity, defined as an excessive accumulation of fat, leads to cardiometabolic pathology through adiposopathy or hypertrophic growth of adipose tissue (AT).This is related to an impaired adipogenic process or death of adipocytes by obesogenic signals. We aimed to evaluate the effect of the pathogenic microenvironment and CCT, activating differentiation of healthy preadipocytes (PA). For this, we used human cryopreserved PA from visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) depots obtained from healthy and obese-DM2 donors. We studied the effect of a metabolically detrimental (diabesogenic) environment, generated by obese-DM2 adipocytes from VAT (VdDM) or SAT (SdDM), on the viability and accumulation of intracellular fat of adipocytes differentiated from healthy PA, in the presence or absence of CCT (1 or 10 µM). Intracellular fat was quantified by Oil Red O staining. Cytotoxicity was measured using the MTT assay. Our results showed that diabesogenic conditions induce cytotoxicity and provide a proadipogenic environment only for visceral PA. CCT at 10 µM acted as an antiadipogenic and cytoprotective compound.

MZ1 co-operates with trastuzumab in HER2 positive breast cancer.

BACKGROUND: Although the anti-HER2 antibody trastuzumab augments patient survival in HER2+ breast cancer, a relevant number of patients progress to this treatment. In this context, novel drug combinations are needed to increase its antitumor activity. In this work, we have evaluated the efficacy of proteolysis targeting chimera (PROTAC) compounds based on BET inhibitors (BETi) to augment the activity of trastuzumab in HER2+ breast cancer models. METHODS: BT474 and SKBR3 HER2+ breast cancer cell lines were used. The effects of trastuzumab and the BET-PROTAC MZ1 either alone or in combination, were evaluated using MTT proliferation assays, three-dimensional invasion and adhesion cultures, flow cytometry, qPCR and Western blot. In vivo studies were carried out in a xenografted model in mice. Finally, a Clariom_S_Human transcriptomic array was applied to identify deregulated genes after treatments. RESULTS: MZ1 induced a higher antiproliferative effect compared to the BETi JQ1. The combination of MZ1 and -trastuzumab significantly decreased cell proliferation, the formation of three-dimensional structures and cellular invasion compared to either of the drugs alone. Evaluation of apoptosis resulted in an increase of cell death following treatment with the combination, and biochemical studies displayed modifications of apoptosis and DNA damage components. In vivo administration of agents alone or combined, to tumors orthotopically xenografted in mice, resulted in a decrease of the tumor volume only after MZ1-Trastuzumab combination treatment. Results from a transcriptomic array indicated a series of newly described transcription factors including HOXB7, MEIS2, TCERG1, and DNAJC2, that were associated to poor outcome in HER2+ breast cancer subtype and downregulated by the MZ1-trastuzumab combination. CONCLUSIONS: We describe an active novel combination that includes the BET-PROTAC MZ1 and trastuzumab, in HER2+ tumors. Further studies should be performed to confirm these findings and pave the way for their future clinical development.

Checkpoint Kinase 1 Pharmacological Inhibition Synergizes with DNA-Damaging Agents and Overcomes Platinum Resistance in Basal-Like Breast Cancer.

Basal-like breast cancer is an incurable disease with limited therapeutic options, mainly due to the frequent development of anti-cancer drug resistance. Therefore, identification of druggable targets to improve current therapies and overcome these resistances is a major goal. Targeting DNA repair mechanisms has reached the clinical setting and several strategies, like the inhibition of the CHK1 kinase, are currently in clinical development. Here, using a panel of basal-like cancer cell lines, we explored the synergistic interactions of CHK1 inhibitors (rabusertib and SAR020106) with approved therapies in breast cancer and evaluated their potential to overcome resistance. We identified a synergistic action of these inhibitors with agents that produce DNA damage, like platinum compounds, gemcitabine, and the PARP inhibitor olaparib. Our results demonstrated that the combination of rabusertib with these chemotherapies also has a synergistic impact on tumor initiation, invasion capabilities, and apoptosis in vitro. We also revealed a biochemical effect on DNA damage and caspase-dependent apoptosis pathways through the phosphorylation of H2AX, the degradation of full-length PARP, and the increase of caspases 3 and 8 activity. This agent also demonstrated synergistic activity in a platinum-resistant cell line, inducing an increase in cell death in response to cisplatin only when combined with rabusertib, while no toxic effect was found on non-tumorigenic breast tissue-derived cell lines. Lastly, the combination of CHK1 inhibitor with cisplatin and gemcitabine resulted in more activity than single or double combinations, leading to a higher apoptotic effect. In conclusion, in our study we identify therapeutic options for the clinical development of CHK1 inhibitors, and confirm that the inhibition of this kinase can overcome acquired resistance to cisplatin.

Inhibition of the mitotic kinase PLK1 overcomes therapeutic resistance to BET inhibitors in triple negative breast cancer.

The inhibition of bromo- and extraterminal domains (BET) has shown an anti-proliferative effect in triple negative breast cancer (TNBC). In this article we explore mechanisms of resistance to BET inhibitors (BETi) in TNBC, with the aim of identifying novel ways to overcome such resistance. Two cellular models of acquired resistance to the BET inhibitor JQ1 were generated using a pulsed treatment strategy. MTT, colony formation, and cytometry assays revealed that BETi-resistant cells were particularly sensitive to PLK1 inhibition. Targeting of the latter reduced cell proliferation, especially in resistant cultures. Quantitative PCR analysis of a panel of mitotic kinases uncovered an increased expression of AURKA, TTK, and PLK1, confirmed by Western blot. Only pharmacological inhibition of PLK1 showed anti-proliferative activity on resistant cells, provoking G2/M arrest, increasing expression levels of cyclin B, pH3 and phosphorylation of Bcl-2 proteins, changes that were accompanied by induction of caspase-dependent apoptosis. JQ1-resistant cells orthotopically xenografted into the mammary fat pad of mice led to tumours that retained JQ1-resistance. Administration of the PLK1 inhibitor volasertib resulted in tumour regression. These findings open avenues to explore the future use of PLK1 inhibitors in the clinical setting of BETi-resistant patients.

Pharmacological screening and transcriptomic functional analyses identify a synergistic interaction between dasatinib and olaparib in triple-negative breast cancer.

Identification of druggable vulnerabilities is a main objective in triple-negative breast cancer (TNBC), where no curative therapies exist. Gene set enrichment analyses (GSEA) and a pharmacological evaluation using a library of compounds were used to select potential druggable combinations. MTT and studies with semi-solid media were performed to explore the activity of the combinations. TNBC cell lines (MDAMB-231, BT549, HS-578T and HCC3153) and an additional panel of 16 cell lines were used to assess the activity of the two compounds. Flow cytometry experiments and biochemical studies were also performed to explore the mechanism of action. GSEA were performed using several data sets (GSE21422, GSE26910, GSE3744, GSE65194 and GSE42568), and more than 35 compounds against the identified functions were evaluated to discover druggable opportunities. Analyses done with the Chou and Talalay algorithm confirmed the synergy of dasatinib and olaparib. The combination of both agents significantly induced apoptosis in a caspase-dependent manner and revealed a pleotropic effect on cell cycle: Dasatinib arrested cells in G0/G1 and olaparib in G2/M. Dasatinib inhibited pChk1 and induced DNA damage measured by pH2AX, and olaparib increased pH3. Finally, the effect of the combination was also evaluated in a panel of 18 cell lines representative of the most frequent solid tumours, observing a particularly synergism in ovarian cancer. Breast cancer, triple negative, dasatinib, olaparib, screening.

Using Syndemics Theory to Examine HIV Sexual Risk Among Latinx Men Who Have Sex with Men in Philadelphia, PA: Findings from the National HIV Behavioral Surveillance.

Latinx men who have sex with men (MSM) continue to be disproportionately impacted by HIV/AIDS. Identifying the role of multiple syndemic factors associated with sexual risk behaviors is imperative in order to develop effective prevention and treatment strategies. Cross-sectional data for this study were derived from three cycles of the Philadelphia portion of the National HIV Behavioral Surveillance System. This study explored the impact of syndemic factors - heavy drinking, exchange sex, and homophobic discrimination - on sexual HIV risk behaviors, operationalized as number of male partners, and condomless anal intercourse (CAI) with main and casual partners among Latinx MSM (n=464). Analyses took two forms: a syndemic approach, using the cumulative number of conditions as an independent variable; and a non-syndemic approach, incorporating each condition as a unique factor. In multivariable syndemic analyses, participants with two or more factors reported more male partners and more CAI casual male partners than those with none. In non-syndemic models, homophobic discrimination and exchange sex were significantly positively associated with total number of male partners, while heavy drinking was associated with more casual CAI partners. Quantitative results indicate that syndemic and non-syndemic approaches vary in their relative capacity to account for sexual risk among Latinx MSM.

RESUMEN: Los hombres latinos que tienen sexo con hombres (HSH) continúan siendo desproporcionadamente afectados por el VIH / SIDA. Identificar el papel de múltiples factores sindémicos asociados con las conductas de riesgo sexual es imprescindible para desarrollar estrategias efectivas de prevención y tratamiento. Los datos transversales para este estudio se derivaron de tres ciclos de la parte de Filadelfia del Sistema Nacional de Vigilancia del Comportamiento del VIH. Este estudio exploró el impacto de los factores sindémicos (consumo excesivo de alcohol, sexo de intercambio y discriminación homofóbica) en los comportamientos sexuales de riesgo de VIH, operacionalizados como el número de parejas masculinas y las relaciones anales sin condón (IAC) con parejas principales y casuales entre los HSH latinos (n = 464). Los análisis tomaron dos formas: un enfoque sindémico, usando el número acumulado de condiciones como una variable independiente; y un enfoque no sindémico, que incorpora cada condición como un factor único. En análisis sinádicos multivariables, los participantes con dos o más factores informaron más parejas masculinas y más parejas masculinas casuales CAI que aquellos sin ninguno. En los modelos no sindémicos, la discriminación homofóbica y el intercambio sexual se asociaron significativamente positivamente con el número total de parejas masculinas, mientras que el consumo excesivo de alcohol se asoció con parejas CAI más casuals. Los resultados cuantitativos indican que los enfoques sindémicos y no sindémicos varían en su capacidad relativa para dar cuenta del riesgo sexual entre los HSH latinos. PALABRAS CLAVE: Conductas de riesgo sexual del VIH, Latinos gays y bisexuales, Condiciones sindémicas, Consumo de alcohol de alto riesgo, Intercambio de sexo, Homofobia.

Expression of MHC class I, HLA-A and HLA-B identifies immune-activated breast tumors with favorable outcome.

Antigen recognition by MHC class I molecules is a key step for the initiation of the immune response. We hypothesized that expression of these molecules could be a marker of immune-activated breast cancers. Data from KM Plotter were extracted to develop an exploratory cohort. Information from Cancer Genome Atlas (TCGA) and METABRIC was used to create two validation cohorts. Raw data were re-processed and analyzed using plyr R and Bioconductor. We predicted epitope-HLA binding to MHC I molecules by using NetMHC 4.0. Cox proportional hazards regression was computed to correlate gene expression and survival outcome. There was a weak but positive correlation between mutational burden and the expression of most MHC class I molecules. In the exploratory cohort, expression of HLA-A and HLA-B was associated with favorable relapse-free survival (RFS) and overall survival (OS) in the basal-like subgroup. This was confirmed in the METABRIC and TCGA dataset. Expression of HLA-A and HLA-B was associated with biomarkers of T cell activation (GZMA, GZMB, and PRF1) and improved the predictive capacity of known immunologic signatures. Several neopeptides expressed in breast cancer were also identified including FUK, SNAPC3, GC, ANO8, DOT1L, HIST1H3F, MYBPH, STX2, FRMD6, CPSF1, or SMTN, among others. Expression of HLA A and B is associated with T cell activation and identifies immune activated, basal-like breast cancers with favorable prognosis. Antigen recognition markers should be incorporated into the assessment of the tumor immune state of basal-like breast patients.

Activity of BET-proteolysis targeting chimeric (PROTAC) compounds in triple negative breast cancer.

BACKGROUND: Triple negative breast cancer (TNBC) is an incurable disease where novel therapeutic strategies are needed. Proteolysis targeting chimeric (PROTAC) are novel compounds that promote protein degradation by binding to an ubiquitin ligase. In this work, we explored the antitumoral activity of two novel BET-PROTACs, MZ1 and ARV-825, in TNBC, ovarian cancer and in a BET inhibitor resistant model. METHODS: OVCAR3, SKOV3, BT549, MDA-MB-231 cell lines and the JQ1 resistant cell line MDA-MB-231R were evaluated. MTTs, colony-forming assay, three-dimensional cultures in matrigel, flow cytometry, and western blots were performed to explore the anti-proliferative effect and biochemical mechanism of action of MZ1 and ARV-825. In vivo studies included BALB/c nu/nu mice engrafted with MDA-MB-231R cells. RESULTS: The BET-PROTACs MZ1 and ARV-825 efficiently downregulated the protein expression levels of the BET protein BRD4, in MDA-MB-231 and MDA-MB-231R. MZ1 and ARV-825 also showed an antiproliferative effect on sensitive and resistant cells. This effect was corroborated in other triple negative (BT549) and ovarian cancer (SKOV3, OVCAR3) cell lines. MZ1 provoked G2/M arrest in MDA-MB-231. In addition, a profound effect on caspase-dependent apoptosis was observed in both sensitive and resistant cells. No synergistic activity was observed when it was combined with docetaxel, cisplatin or olaparib. Finally, in vivo administration of MZ1 rescued tumor growth in a JQ1-resistant xenograft model, reducing the expression levels of BRD4. CONCLUSIONS: Using both in vitro and in vivo approaches, we describe the profound activity of BET-PROTACs in parental and BETi-resistant TNBC models. This data provides options for further clinical development of these agents in TNBC.