Faecal immunochemical tests can improve colonoscopy triage in patients with iron deficiency: A systematic review and meta-analysis.

BACKGROUND: Use of the faecal immunochemical test (FIT) to triage patients with iron deficiency (ID) for colonoscopy due to suspected colorectal cancer (CRC) may improve distribution of colonoscopic resources. We reviewed the diagnostic performance of FIT for detecting advanced colorectal neoplasia, including CRC and advanced pre-cancerous neoplasia (APCN), in patients with ID, with or without anaemia. METHODS: We performed a systematic review of three databases for studies comprising of patients with ID, with or without anaemia, completing a quantitative FIT within six months prior to colonoscopy, where test performance was compared against the reference standard colonoscopy. Random effects meta-analyses determined the diagnostic performance of FIT for advanced colorectal neoplasia. RESULTS: Nine studies were included on a total of n=1761 patients with ID, reporting FIT positivity thresholds between 4-150 µg haemoglobin/g faeces. Only one study included a non-anaemic ID (NAID) cohort. FIT detected CRC and APCN in ID patients with 90.7 % and 49.3 % sensitivity, and 81.0 % and 82.4 % specificity, respectively. FIT was 88.0 % sensitive and 83.4 % specific for CRC in patients with ID anaemia at a FIT positivity threshold of 10 µg haemoglobin/g faeces. CONCLUSIONS: FIT shows high sensitivity for advanced colorectal neoplasia and may be used to triage those with ID anaemia where colonoscopic resources are limited, enabling those at higher risk of CRC to be prioritised for colonoscopy. There is a need for further research investigating the diagnostic performance of FIT in NAID patients.

Accuracy, Acceptability, and Application: Fecal Immunochemical Tests for Early Detection of Advanced Neoplasia in Colonoscopy-Based Surveillance.

BACKGROUND: The fecal immunochemical test (FIT) is widely used in colorectal cancer (CRC) screening, but limited data exist for its application in individuals at above-average risk for CRC who complete surveillance colonoscopies. AIM: To assess the accuracy, acceptability, and effectiveness of FIT in the interval between surveillance colonoscopies, for predicting advanced neoplasia (advanced adenoma or CRC) at the next colonoscopy. METHODS: Individuals enrolled in an Australian surveillance program were included. Diagnostic accuracy was determined for 614 individuals completing a two-sample FIT (OC-Sensor) ≤ 3 months preceding surveillance colonoscopy. 386 Individuals were surveyed to assess acceptability of interval FIT. Additionally, a retrospective analysis was performed on 7331 individuals offered interval FIT between colonoscopies, where a positive FIT (≥ 20 µg hemoglobin/g feces) triggered an early colonoscopy. Associations between interval FIT results and advanced neoplasia were determined using regression analysis. RESULTS: FIT detected CRC and advanced adenoma with sensitivities of 60.0% (3/5) and 27.1% (35/129), respectively. Most (89.1%, 344/386) survey respondents preferred completing interval FIT every 1-2 years. The detection rate of interval FIT for advanced neoplasia decreased with increasing FIT completion. Individuals returning a positive FIT had a higher risk of advanced neoplasia than those who did not complete FIT. Positive interval FIT reduced time-to-diagnosis for CRC and advanced adenoma by a median of 30 and 20 months, respectively. CONCLUSION: Interval FIT was well accepted and enabled earlier detection of advanced neoplasia in individuals at above-average risk of CRC. Given that interval FIT predicts advanced neoplasia, it may be used to personalize surveillance colonoscopy intervals.

BCAT1, IKZF1 and SEPT9: methylated DNA biomarkers for detection of pan-gastrointestinal adenocarcinomas.

INTRODUCTION: Methylated circulating tumour DNA (ctDNA) blood tests for BCAT1/IKZF1 (COLVERA) and SEPT9 (Epi proColon) are used to detect colorectal cancer (CRC). However, there are no ctDNA assays approved for other gastrointestinal adenocarcinomas. We aimed to characterize BCAT1, IKZF1 and SEPT9 methylation in different gastrointestinal adenocarcinoma and non-gastrointestinal tumours to determine if these validated CRC biomarkers might be useful for pan-gastrointestinal adenocarcinoma detection. METHODS: Tissue DNA methylation data from colorectal (COAD, READ), gastroesophageal (ESCA, STAD), pancreatic (PAAD) and cholangiocarcinoma (CHOL) adenocarcinoma cohorts within The Cancer Genome Atlas were used for differential methylation analyses. Clinicodemographic predictors of BCAT1, IKZF1 and SEPT9 methylation, and the selectivity of hypermethylated BCAT1, IKZF1 and SEPT9 for colorectal adenocarcinomas in comparison to other cancers were each explored with beta regression. RESULTS: Hypermethylated BCAT1, IKZF1 and SEPT9 were each differentially methylated in colorectal and gastroesophageal adenocarcinomas. IKZF1 was differentially methylated in pancreatic adenocarcinoma. Hypermethylated DNA biomarkers BCAT1, IKZF1 and SEPT9 were largely stable across different stages of disease and were highly selective for gastrointestinal adenocarcinomas relative to other cancer types. DISCUSSION: Existing CRC methylated ctDNA blood tests for BCAT1/IKZF1 and SEPT9 might be usefully repurposed for use in other gastrointestinal adenocarcinomas and warrant further prospective ctDNA studies.

Comparing a fecal immunochemical test and circulating tumor DNA blood test for colorectal cancer screening adherence.

BACKGROUND AND AIM: Colorectal cancer (CRC) screening programs are most effective at reducing disease incidence and mortality through sustained screening participation. A novel blood test modality is being explored for CRC screening, but it is unclear whether it will provide sustained screening participation. This study aimed to investigate whether a circulating tumor DNA (ctDNA) blood test improved CRC screening re-participation when compared with a fecal immunochemical test (FIT) and to define the predictors of sustained CRC screening in an Australian population. METHODS: South Australians who initially participated in CRC screening using a ctDNA blood test (n = 36) or FIT (n = 547) were offered the same CRC screening test approximately 2 years later through an extended phase of a randomized controlled trial. Surveys collected demographic, psychosocial, and clinical information. Predictors of CRC screening re-participation were explored using chi-square, Wilcoxon tests, and logistic regression. RESULTS: Participants offered a second ctDNA blood test were equally likely to re-participate in CRC screening as those who completed a FIT in the first round and who were offered the same test (61% vs 66% re-participation respectively, P = 0.6). CRC fatalism, health activation, and self-efficacy were associated with repeated screening participation. Test awareness was predictive of repeated FIT-based CRC screening. CONCLUSIONS: Targeted interventions to improve CRC screening awareness and increase patient health activation may improve CRC screening adherence. A ctDNA blood test may be a suitable CRC screening option to maintain CRC screening adherence in people who do not participate in screening with FIT.

The androgen receptor interacts with GATA3 to transcriptionally regulate a luminal epithelial cell phenotype in breast cancer.

BACKGROUND: The androgen receptor (AR) is a tumor suppressor in estrogen receptor (ER) positive breast cancer, a role sustained in some ER negative breast cancers. Key factors dictating AR genomic activity in a breast context are largely unknown. Herein, we employ an unbiased chromatin immunoprecipitation-based proteomic technique to identify endogenous AR interacting co-regulatory proteins in ER positive and negative models of breast cancer to gain new insight into mechanisms of AR signaling in this disease. RESULTS: The DNA-binding factor GATA3 is identified and validated as a novel AR interacting protein in breast cancer cells irrespective of ER status. AR activation by the natural ligand 5α-dihydrotestosterone (DHT) increases nuclear AR-GATA3 interactions, resulting in AR-dependent enrichment of GATA3 chromatin binding at a sub-set of genomic loci. Silencing GATA3 reduces but does not prevent AR DNA binding and transactivation of genes associated with AR/GATA3 co-occupied loci, indicating a co-regulatory role for GATA3 in AR signaling. DHT-induced AR/GATA3 binding coincides with upregulation of luminal differentiation genes, including EHF and KDM4B, established master regulators of a breast epithelial cell lineage. These findings are validated in a patient-derived xenograft model of breast cancer. Interaction between AR and GATA3 is also associated with AR-mediated growth inhibition in ER positive and ER negative breast cancer. CONCLUSIONS: AR and GATA3 interact to transcriptionally regulate luminal epithelial cell differentiation in breast cancer regardless of ER status. This interaction facilitates the tumor suppressor function of AR and mechanistically explains why AR expression is associated with less proliferative, more differentiated breast tumors and better overall survival in breast cancer.

The potential of epigenetic therapy to target the 3D epigenome in endocrine-resistant breast cancer.

Three-dimensional (3D) epigenome remodeling is an important mechanism of gene deregulation in cancer. However, its potential as a target to counteract therapy resistance remains largely unaddressed. Here, we show that epigenetic therapy with decitabine (5-Aza-mC) suppresses tumor growth in xenograft models of pre-clinical metastatic estrogen receptor positive (ER+) breast tumor. Decitabine-induced genome-wide DNA hypomethylation results in large-scale 3D epigenome deregulation, including de-compaction of higher-order chromatin structure and loss of boundary insulation of topologically associated domains. Significant DNA hypomethylation associates with ectopic activation of ER-enhancers, gain in ER binding, creation of new 3D enhancer-promoter interactions and concordant up-regulation of ER-mediated transcription pathways. Importantly, long-term withdrawal of epigenetic therapy partially restores methylation at ER-enhancer elements, resulting in a loss of ectopic 3D enhancer-promoter interactions and associated gene repression. Our study illustrates the potential of epigenetic therapy to target ER+ endocrine-resistant breast cancer by DNA methylation-dependent rewiring of 3D chromatin interactions, which are associated with the suppression of tumor growth.

Selective inhibition of CDK9 in triple negative breast cancer.

Targeted therapy for triple-negative breast cancers (TNBC) remains a clinical challenge due to tumour heterogeneity. Since TNBC have key features of transcriptionally addicted cancers, targeting transcription via regulators such as cyclin-dependent kinase 9 (CDK9) has potential as a therapeutic strategy. Herein, we preclinically tested a new selective CDK9 inhibitor (CDDD11-8) in TNBC using cell line, patient-derived organoid, and patient-derived explant models. In vitro, CDDD11-8 dose-dependently inhibited proliferation (IC50 range: 281-734 nM), induced cell cycle arrest, and increased apoptosis of cell lines, which encompassed the three major molecular subtypes of TNBC. On target inhibition of CDK9 activity was demonstrated by reduced RNAPII phosphorylation at a CDK9 target peptide and down-regulation of the MYC and MCL1 oncogenes at the mRNA and protein levels in all cell line models. Drug induced RNAPII pausing was evident at gene promoters, with strongest pausing at MYC target genes. Growth of five distinct patient-derived organoid models was dose-dependently inhibited by CDDD11-8 (IC50 range: 272-771 nM), including three derived from MYC amplified, chemo-resistant TNBC metastatic lesions. Orally administered CDDD11-8 also inhibited growth of mammary intraductal TNBC xenograft tumours with no overt toxicity in vivo (mice) or ex vivo (human breast tissues). In conclusion, our studies indicate that CDK9 is a viable therapeutic target in TNBC and that CDDD11-8, a novel selective CDK9 inhibitor, has efficacy in TNBC without apparent toxicity to normal tissues.

The Diagnostic Accuracy of a Fecal Immunochemical Test in Detecting Colorectal Cancer and Advanced Precancerous Colorectal Neoplasia in Patients with Iron Deficiency: A Protocol for Systematic Review and Meta-Analysis.

Background. Iron deficiency (ID) is a common micronutrient deficiency and the leading cause of anemia worldwide. ID can be caused by chronic occult blood loss from colorectal neoplasia including colorectal cancer (CRC) and advanced precancerous colorectal lesions. Current guidelines recommend colonoscopy in both men and postmenopausal women presenting with ID anemia (IDA). However, there is controversy on the investigation of patients presenting with a lower risk of CRC including younger women with ID and those with nonanemic ID (NAID). There is a need for a triaging tool to identify which ID patients may benefit from colonoscopy. The fecal immunochemical test (FIT) is sensitive for CRC screening in an asymptomatic population, but its role in ID patients is unclear. The aim of this study is to conduct a systematic review to determine the diagnostic accuracy of FIT for detecting CRC and advanced precancerous neoplasia in individuals presenting with ID with or without anemia. Methods and Analysis. This protocol conforms with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A comprehensive search of the MEDLINE, Embase, and Web of Science databases will be undertaken for studies published after 2010 which involve patients with ID, who completed a FIT in the 6 months prior to colonoscopy, with FIT sensitivity and specificity calculated against the reference standard colonoscopy. The search will be limited to studies conducted after 2010 to reduce variability in colonoscopy quality. Risk of bias assessment will be conducted using the Quality Assessment of Diagnostic Accuracy Studies version 2. FIT sensitivity and specificity will be the primary measure of diagnostic accuracy, and data will be analysed using a random effects meta-analysis. Discussion. This review and meta-analysis will be the first to systematically explore the value of the FIT as a triaging tool for patients with ID. This trial is registered with CRD42022367162.

Hot Mail: Temperature Exposure during Mail Return of an Immunochemical Fecal Occult Blood Test.

BACKGROUND: Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening; however, high ambient temperatures were found to reduce test accuracy. More recently, proprietary globin stabilizers were added to FIT sample buffers to prevent temperature-associated hemoglobin (Hb) degradation, but their effectiveness remains uncertain. We aimed to determine the impact of high temperature (>30°C) on OC-Sensor FIT Hb concentration with current FITs, characterize FIT temperatures during mail transit, and determine impact of ambient temperature on FIT Hb concentration using data from a CRC screening program. METHODS: FITs were analyzed for Hb concentration after in vitro incubation at different temperatures. Data loggers packaged alongside FITs measured temperatures during mail transit. Separately, screening program participants completed and mailed FITs to the laboratory for Hb analysis. Regression analyses compared the impact of environmental variables on FIT temperatures and separately on FIT sample Hb concentration. RESULTS: In vitro incubation at 30 to 35°C reduced FIT Hb concentration after >4 days. During mail transit, maximum FIT temperature averaged 6.4°C above maximum ambient temperature, but exposure to temperature above 30°C was for less than 24 hours. Screening program data showed no association between FIT Hb concentration and maximum ambient temperatures. CONCLUSIONS: Although FIT samples are exposed to elevated temperatures during mail transit, this is brief and does not significantly reduce FIT Hb concentration. These data support continuation of CRC screening during warm weather with modern FITs with a stabilizing agent when mail delivery is ≤4 days.

The androgen receptor is a tumor suppressor in estrogen receptor-positive breast cancer.

The role of the androgen receptor (AR) in estrogen receptor (ER)-α-positive breast cancer is controversial, constraining implementation of AR-directed therapies. Using a diverse, clinically relevant panel of cell-line and patient-derived models, we demonstrate that AR activation, not suppression, exerts potent antitumor activity in multiple disease contexts, including resistance to standard-of-care ER and CDK4/6 inhibitors. Notably, AR agonists combined with standard-of-care agents enhanced therapeutic responses. Mechanistically, agonist activation of AR altered the genomic distribution of ER and essential co-activators (p300, SRC-3), resulting in repression of ER-regulated cell cycle genes and upregulation of AR target genes, including known tumor suppressors. A gene signature of AR activity positively predicted disease survival in multiple clinical ER-positive breast cancer cohorts. These findings provide unambiguous evidence that AR has a tumor suppressor role in ER-positive breast cancer and support AR agonism as the optimal AR-directed treatment strategy, revealing a rational therapeutic opportunity.

Androgen Receptor Signalling Promotes a Luminal Phenotype in Mammary Epithelial Cells.

Androgens influence mammary gland development but the specific role of the androgen receptor (AR) in mammary function is largely unknown. We identified cell subsets that express AR in vivo and determined the effect of AR activation and transgenic AR inhibition on sub-populations of the normal mouse mammary epithelium by flow cytometry and immunohistochemistry. Immunolocalisation of AR with markers of lineage identity was also performed in human breast tissues. AR activation in vivo significantly decreased the proportion of basal cells, and caused an accumulation of cells that expressed a basal cell marker but exhibited morphological features of luminal identity. Conversely, in AR null mice the proportion of basal mammary epithelial cells was significantly increased. Inhibition of AR increased basal but not luminal progenitor cell activity in vitro. A small population of AR-positive cells in a basal-to-luminal phenotype transition was also evident in human breast lobules. Collectively, these data support a role for AR in promoting a luminal phenotype in mammary epithelial cells.

Non-canonical AR activity facilitates endocrine resistance in breast cancer.

The role of androgen receptor (AR) in endocrine-resistant breast cancer is controversial and clinical trials targeting AR with an AR antagonist (e.g., enzalutamide) have been initiated. Here, we investigated the consequence of AR antagonism using in vitro and in vivo models of endocrine resistance. AR antagonism in MCF7-derived tamoxifen-resistant (TamR) and long-term estrogen-deprived breast cancer cell lines were achieved using siRNA-mediated knockdown or pharmacological inhibition with enzalutamide. The efficacy of enzalutamide was further assessed in vivo in an estrogen-independent endocrine-resistant patient-derived xenograft (PDX) model. Knockdown of AR inhibited the growth of the endocrine-resistant cell line models. Microarray gene expression profiling of the TamR cells following AR knockdown revealed perturbations in proliferative signaling pathways upregulated in endocrine resistance. AR loss also increased some canonical ER signaling events and restored sensitivity of TamR cells to tamoxifen. In contrast, enzalutamide did not recapitulate the effect of AR knockdown in vitro, even though it inhibited canonical AR signaling, which suggests that it is the non-canonical AR activity that facilitated endocrine resistance. Enzalutamide had demonstrable efficacy in inhibiting AR activity in vivo but did not affect the growth of the endocrine-resistant PDX model. Our findings implicate non-canonical AR activity in facilitating an endocrine-resistant phenotype in breast cancer. Unlike canonical AR signaling which is inhibited by enzalutamide, non-canonical AR activity is not effectively antagonized by enzalutamide, and this has important implications in the design of future AR-targeted clinical trials in endocrine-resistant breast cancer.

Evaluation of robenidine analog NCL195 as a novel broad-spectrum antibacterial agent.

The spread of multidrug resistance among bacterial pathogens poses a serious threat to public health worldwide. Recent approaches towards combating antimicrobial resistance include repurposing old compounds with known safety and development pathways as new antibacterial classes with novel mechanisms of action. Here we show that an analog of the anticoccidial drug robenidine (4,6-bis(2-((E)-4-methylbenzylidene)hydrazinyl)pyrimidin-2-amine; NCL195) displays potent bactericidal activity against Streptococcus pneumoniae and Staphylococcus aureus by disrupting the cell membrane potential. NCL195 was less cytotoxic to mammalian cell lines than the parent compound, showed low metabolic degradation rates by human and mouse liver microsomes, and exhibited high plasma concentration and low plasma clearance rates in mice. NCL195 was bactericidal against Acinetobacter spp and Neisseria meningitidis and also demonstrated potent activity against A. baumannii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Enterobacter spp. in the presence of sub-inhibitory concentrations of ethylenediaminetetraacetic acid (EDTA) and polymyxin B. These findings demonstrate that NCL195 represents a new chemical lead for further medicinal chemistry and pharmaceutical development to enhance potency, solubility and selectivity against serious bacterial pathogens.

Small Glutamine-Rich Tetratricopeptide Repeat-Containing Protein Alpha (SGTA) Ablation Limits Offspring Viability and Growth in Mice.

Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) has been implicated as a co-chaperone and regulator of androgen and growth hormone receptor (AR, GHR) signalling. We investigated the functional consequences of partial and full Sgta ablation in vivo using Cre-lox Sgta-null mice. Sgta(+/-) breeders generated viable Sgta(-/-) offspring, but at less than Mendelian expectancy. Sgta(-/-) breeders were subfertile with small litters and higher neonatal death (P < 0.02). Body size was significantly and proportionately smaller in male and female Sgta(-/-) (vs WT, Sgta(+/-) P < 0.001) from d19. Serum IGF-1 levels were genotype- and sex-dependent. Food intake, muscle and bone mass and adiposity were unchanged in Sgta(-/-). Vital and sex organs had normal relative weight, morphology and histology, although certain androgen-sensitive measures such as penis and preputial size, and testis descent, were greater in Sgta(-/-). Expression of AR and its targets remained largely unchanged, although AR localisation was genotype- and tissue-dependent. Generally expression of other TPR-containing proteins was unchanged. In conclusion, this thorough investigation of SGTA-null mutation reports a mild phenotype of reduced body size. The model's full potential likely will be realised by genetic crosses with other models to interrogate the role of SGTA in the many diseases in which it has been implicated.

Hormone-sensing mammary epithelial progenitors: emerging identity and hormonal regulation.

The hormone-sensing mammary epithelial cell (HS-MEC-expressing oestrogen receptor-alpha (ERα) and progesterone receptor (PGR)) is often represented as being terminally differentiated and lacking significant progenitor activity after puberty. Therefore while able to profoundly influence the proliferation and function of other MEC populations, HS-MECs are purported not to respond to sex hormone signals by engaging in significant cell proliferation during adulthood. This is a convenient and practical simplification that overshadows the sublime, and potentially critical, phenotypic plasticity found within the adult HS-MEC population. This concept is exemplified by the large proportion (~80 %) of human breast cancers expressing PGR and/or ERα, demonstrating that HS-MECs clearly proliferate in the context of breast cancer. Understanding how HS-MEC proliferation and differentiation is driven could be key to unraveling the mechanisms behind uncontrolled HS-MEC proliferation associated with ERα- and/or PGR-positive breast cancers. Herein we review evidence for the existence of a HS-MEC progenitor and the emerging plasticity of the HS-MEC population in general. This is followed by an analysis of hormones other than oestrogen and progesterone that are able to influence HS-MEC proliferation and differentiation: androgens, prolactin and transforming growth factor-beta1.