Tumor monocyte content predicts immunochemotherapy outcomes in esophageal adenocarcinoma

For inoperable esophageal adenocarcinoma (EAC), identifying patients likely to benefit from recently approved immunochemotherapy (ICI+CTX) treatments remains a key challenge. We address this using a uniquely designed window-of-opportunity trial (LUD2015-005), in which 35 inoperable EAC patients received first-line immune checkpoint inhibitors for four weeks (ICI-4W), followed by ICI+CTX. Comprehensive biomarker profiling, including generation of a 65,000-cell single-cell RNA-sequencing atlas of esophageal cancer, as well as multi-timepoint transcriptomic profiling of EAC during ICI-4W, reveals a novel T cell inflammation signature (INCITE) whose upregulation correlates with ICI-induced tumor shrinkage. Deconvolution of pre-treatment gastro-esophageal cancer transcriptomes using our single-cell atlas identifies high tumor monocyte content (TMC) as an unexpected ICI+CTX-specific predictor of greater overall survival (OS) in LUD2015-005 patients and of ICI response in prevalent gastric cancer subtypes from independent cohorts. Tumor mutational burden is an additional independent and additive predictor of LUD2015-005 OS. TMC can improve patient selection for emerging ICI+CTX therapies in gastro-esophageal cancer.

Abstract 1247: Comprehensive molecular profiling to predict first-line immunochemotherapy outcomes in inoperable esophageal adenocarcinoma

For patients with inoperable esophageal adenocarcinoma (EAC), prognosis on conventional chemotherapy (CTX) remains poor. In 2021, the FDA approved two αPD-1 immune checkpoint inhibitors (ICI) for addition to fluoropyrimidine/platinum-containing CTX in this first-line setting. As ICI+CTX enters the clinic, understanding ICI responses and predicting which patients will benefit from ICI addition are key challenges. To address these challenges, we assessed clinical and molecular profiles from the experimental LUD2015-005 trial (NCT02735239, EudraCT 2015-005298-19). Treatment consisted of an initial four-week ICI-only window with durvalumab (αPD-L1) with or without a single dose of tremelimumab (αCTLA-4), followed by 6 cycles of ICI+CTX (CapOx). 38 inoperable patients received treatment (35 EAC; 3 ESCC); median overall survival (OS) and progression-free survival (PFS) were 13.4 and 9.3 months, respectively. All patients reported at least one treatment emergent adverse event (TEAE), with 29 (76.3%) reporting grade 3 or higher TEAEs. EAC patients with available samples (n = 33) were taken forward for biomarker analysis, using tumor and adjacent normal biopsies collected at pre-treatment (PreTx), after four weeks of ICI-only (ICI-4W), and at the end of ICI+CTX (PostTx).

Transcriptomic comparison of paired PreTx and ICI-4W EAC biopsies (n = 28) revealed ICI-induced upregulation of a novel T-cell inflammation signature (termed INCITE). Stronger INCITE upregulation correlated with greater tumor shrinkage during the ICI-only window, and tumors with minimal INCITE upregulation showed markers of ICI resistance, including Innate PD-1 Resistance (IPRES). Despite correlation with ICI-only responses, INCITE changes were not associated with overall ICI+CTX outcomes.

To find predictive biomarkers of ICI+CTX outcomes, we conducted comprehensive genomic and transcriptomic profiling of PreTx EAC biopsies (n = 33). First, we generated a novel 65,000 cell scRNA-seq dataset and designed a deconvolution workflow to resolve tumor cell composition. Unexpectedly, monocyte composition was strongly linked with greater overall survival (OS) (HR: 0.40 [0.23-0.69]; p = 0.001; FDR = 0.047). Coding tumor mutational burden (TMB) was also associated with improved OS (HR: 0.50 [0.28-0.89]; p = 0.019). Multivariate modelling suggested monocyte composition and TMB were independent and complementary predictors of outcomes. Neither factor was associated with outcomes in a TCGA cohort of EAC patients not treated with ICI, suggesting these biomarkers may be specific to ICI or ICI+CTX.

Our findings suggest monocyte composition and TMB may identify EAC patients likely to benefit from ICI+CTX. INCITE upregulation may also serve as a useful monitor of ICI efficacy. These timely findings further our understanding of ICI response and resistance and may help inform patient selection for ICI+CTX.

Citation Format: Thomas M. Carroll, Joseph A. Chadwick, Richard P. Owen, Michael J. White, Joseph Kaplinsky, Iliana Peneva, Anna Frangou, Jaeho Chang, Phil F. Xie, Andrew Roth, Bob Amess, Hantao Lou, Katy J. McCann, Georgina Berridge, Roman Fischer, Chansavath Phetsouphanh, Ayo O. Omiyale, Brittany-Amber Jacobs, David Ahern, Simon R. Lord, Stewart Norris-Bulpitt, Sam T. Dobbie, Lucinda Griffiths, Kristen Aufiero Ramirez, Toni Ricciardi, Mary J. Macri, Aileen Ryan, Ralph R. Venhaus, Benoit J. Van den Eynde, Ioannis Karydis, Benedikt M. Kessler, Benjamin Schuster-Böckler, Mark R. Middleton, Xin Lu. Comprehensive molecular profiling to predict first-line immunochemotherapy outcomes in inoperable esophageal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1247.

Taenia larvae possess distinct acetylcholinesterase profiles with implications for host cholinergic signalling

Larvae of the cestodes Taenia solium and Taenia crassiceps infect the central nervous system of humans. Taenia solium larvae in the brain cause neurocysticercosis, the leading cause of adult-acquired epilepsy worldwide. Relatively little is understood about how cestode-derived products modulate host neural and immune signalling. Acetylcholinesterases, a class of enzyme that breaks down acetylcholine, are produced by a host of parasitic worms to aid their survival in the host. Acetylcholine is an important signalling molecule in both the human nervous and immune systems, with powerful modulatory effects on the excitability of cortical networks. Therefore, it is important to establish whether cestode derived acetylcholinesterases may alter host neuronal cholinergic signalling. Here we make use of multiple techniques to profile acetylcholinesterase activity in different extracts of both Taenia crassiceps and Taenia solium larvae. We find that the larvae of both species contain substantial acetylcholinesterase activity. However, acetylcholinesterase activity is lower in Taenia solium as compared to Taenia crassiceps larvae. Further, whilst we observed acetylcholinesterase activity in all fractions of Taenia crassiceps larvae, including on the membrane surface and in the excreted/secreted extracts, we could not identify acetylcholinesterases on the membrane surface or in the excreted/secreted extracts of Taenia solium larvae. Bioinformatic analysis revealed conservation of the functional protein domains in the Taenia solium acetylcholinesterases, when compared to the homologous human sequence. Finally, using whole-cell patch clamp recordings in rat hippocampal brain slice cultures, we demonstrate that Taenia larval derived acetylcholinesterases can break down acetylcholine at a concentration which induces changes in neuronal signalling. Together, these findings highlight the possibility that Taenia larval acetylcholinesterases can interfere with cholinergic signalling in the host, potentially contributing to pathogenesis in neurocysticercosis.

Infection of the human nervous system with larvae of the parasite Taenia solium is a significant cause of acquired epilepsy worldwide. Despite this, the precise cellular and molecular mechanisms underlying epileptogenesis in neurocysticercosis remain unclear. Acetylcholinesterases are a family of enzymes widely produced by helminthic parasites. These enzymes facilitate the breakdown of acetylcholine, which is also a major neurotransmitter in the human nervous system. If T. solium larvae produce acetylcholinesterases, this could potentially disrupt host cholinergic signalling, which may in turn contribute to seizures and epilepsy. We therefore set out to investigate the presence and activity of acetylcholinesterases in T. solium larvae, as well as in Taenia crassiceps larvae, a species commonly used as a model parasite in neurocysticercosis research. We found that both T. crassiceps and T. solium larvae produce acetylcholinesterases with substantial activity and that the functional protein domains in the Taenia solium acetylcholinesterases have great similarity to those of human acetylcholinesterases. We further demonstrate that the acetylcholinesterase activity in the products of these parasites is sufficient to break down acetylcholine at a concentration which induces changes in neuronal signalling in an ex vivo brain slice model. This study provides evidence that Taenia larvae produce acetylcholinesterases and that these can potentially interfere with cholinergic signalling in the host and contribute to pathogenesis in neurocysticercosis.

Gastrointestinal Nematode-Derived Antigens Alter Colorectal Cancer Cell Proliferation and Migration through Regulation of Cell Cycle and Epithelial-Mesenchymal Transition Proteins

As the global incidences of colorectal cancer rises, there is a growing importance in understanding the interaction between external factors, such as common infections, on the initiation and progression of this disease. While certain helminth infections have been shown to alter the severity and risk of developing colitis-associated colorectal cancer, whether these parasites can directly affect colorectal cancer progression is unknown. Here, we made use of murine and human colorectal cancer cell lines to demonstrate that exposure to antigens derived from the gastrointestinal nematode Heligmosomoides polygyrus significantly reduced colorectal cancer cell proliferation in vitro. Using a range of approaches, we demonstrate that antigen-dependent reductions in cancer cell proliferation and viability are associated with increased expression of the critical cell cycle regulators p53 and p21. Interestingly, H. polygyrus-derived antigens significantly increased murine colorectal cancer cell migration, which was associated with an increased expression of the adherens junction protein β-catenin, whereas the opposite was true for human colorectal cancer cells. Together, these findings demonstrate that antigens derived from a gastrointestinal nematode can significantly alter colorectal cancer cell behavior. Further in-depth analysis may reveal novel candidates for targeting and treating late-stage cancer.

Serial sevens: not the most effective test of mental status in high school athletes

OBJECTIVE

To evaluate the ability of uninjured high school athletes to pass three mental status tests that are commonly used on the sidelines for the evaluation of concussions: the serial sevens test, the serial threes test, and recitation of months of year in reverse order (MOYR).

PARTICIPANTS

High school student athletes in grades 9, 10, 11, and 12 having sports preparticipation physical examinations. The initial study tested 522 consecutive athletes. The follow-up study tested 109 consecutive athletes.

INTERVENTION

The athletes of the initial group were asked to perform a serial sevens test, followed by a serial threes test, and finally to recite the MOYR. The second group was asked to perform the same tests in a random order.

MAIN OUTCOME MEASURES

Participants were given 1-min time limits for each test, with passing defined as either 7 consecutive correct iterations or 11 correct with one mistake.

RESULTS

For the initial group, 51.3% successfully performed serial sevens, 78.7% successfully performed serial threes, and 89.5% successfully recited the MOYR. For the second group, 52.7% successfully performed serial sevens, 78.1% successfully performed serial threes, and 88.9% successfully recited the MOYR. The pass rates were significantly different for both groups. The pass rates were similar for both sexes, all grade levels, and all sports in both test groups. Participants, both overall and in all subgroups, failed serial sevens more often than serial threes and MOYR (p < 0.001 for the initial group; p < 0.0001 for the second group). They failed serial threes more often than MOYR (p < 0.001 for the initial group; p < 0.01 for the second group).

CONCLUSIONS

The percentage of uninjured high school athletes successfully completing serial sevens is too low to make the test useful for evaluation of concussion; the test lacks specificity. The percentage of athletes passing the MOYR was greatest, perhaps making this a better sideline test than the traditional serial sevens test. However, testing needs to be done in injured athletes before clinical application can be recommended.

Laser beam recording of video master disks

A method for real time recording of video information on a disk by means of a laser beam is described. The laser beam is focused on a rotating substrate, covered with a thin film of positive photoresist. During exposure the laser beam is intensity modulated by means of an electrooptic modulator driven by the encoded video signal. After etching away the exposed areas of photoresist a master disk is obtained with pits, containing the video information in their periodicity and length. Such a master disk will serve as the source for generating submasters, stampers, etc. for the production of a large number of replicas as is usually done in the phonograph record industry.