Neuroendocrine neoplasms of the lung and gastrointestinal system: convergent biology and a path to better therapies

miR-223 and Chromogranin A Affect Inflammatory Immune Cell Activation in Liver Metastasis of Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs) are a diverse group originating from endocrine cells/their precursors in pancreas, small intestine, or lung. The key serum marker is chromogranin A (CgA). While commonly elevated in patients with NEN, its prognostic value is still under discussion. Secretion/posttranslational proteolytic cleavage of CgA results in multiple bioactive fragments, which are essential regulators of the cardiovascular and immune system. miR-223, regulator of Nrlp3 inflammasome and neutrophil activation, was recently found to have decreased in patients with NEN. We performed flow cytometry of circulating neutrophils in a patient cohort (n = 10) with NEN, microdissection and histology of tumor tissue. Subsequently, in vitro transfections using the well-established human pancreatic NEN cell line (BON), and co-culture experiments with primary macrophages and neutrophils were performed. Serum miR-223 in patients correlated with the expression of the neutrophil activation marker CD15 in circulating cells. Neutrophilic CD62L/CD63 showed good discrimination compared to healthy controls. Immune cell-derived miR-155, miR-193 and miR-223 colocalize with neutrophil in the extra-tumoral tissue alongside Nlrp3-associated caspase-1 activation. miR-223 knockdown in BON decreased the CgA intracellularly, increased in cellular granularity and caspase-1 activation. Plasmin inhibitor a2-aP reverted those effects. Western Blot showed fragmented CgA following miR-223 knockdown, which altered the inflammatory potential of neutrophils. Our data hence provide initial insights into an immunoregulatory mechanism via miR-223 and CgA in NEN cells, as regulation of miR-223 in NEN may affect tumor-associated inflammation.

Chromothripsis-Mediated Small Cell Lung Carcinoma

Small cell lung carcinoma (SCLC) is a highly aggressive malignancy that is typically associated with tobacco exposure and inactivation of RB1 and TP53 genes. Here, we performed detailed clinicopathologic, genomic, and transcriptomic profiling of an atypical subset of SCLC that lacked RB1 and TP53 co-inactivation and arose in never/light smokers. We found that most cases were associated with chromothripsis-massive, localized chromosome shattering-recurrently involving chromosome 11 or 12 and resulting in extrachromosomal amplification of CCND1 or co-amplification of CCND2/CDK4/MDM2, respectively. Uniquely, these clinically aggressive tumors exhibited genomic and pathologic links to pulmonary carcinoids, suggesting a previously uncharacterized mode of SCLC pathogenesis via transformation from lower-grade neuroendocrine tumors or their progenitors. Conversely, SCLC in never-smokers harboring inactivated RB1 and TP53 exhibited hallmarks of adenocarcinoma-to-SCLC derivation, supporting two distinct pathways of plasticity-mediated pathogenesis of SCLC in never-smokers. Significance: Here, we provide the first detailed description of a unique SCLC subset lacking RB1/TP53 alterations and identify extensive chromothripsis and pathogenetic links to pulmonary carcinoids as its hallmark features. This work defines atypical SCLC as a novel entity among lung cancers, highlighting its exceptional histogenesis, clinicopathologic characteristics, and therapeutic vulnerabilities. See related commentary by Nadeem and Drapkin, p. 8.

The clinicopathological and molecular features of primary high-grade neuroendocrine tumour in the breast

AIMS

Nottingham grade for breast cancers, rather than gastro-entero-pancreatic (GEP) grade for neuroendocrine tumours (NETs), is currently applied to primary breast NETs, which need further clarification. High-grade NETs in breast also remain poorly recognised.

METHODS AND RESULTS

Among 595 breast carcinomas with diffuse synaptophysin (Syn) or chromogranin A (CgA) immunostaining (≥ 90%), 197 eligible cases were selected, including 69 NETs, 123 invasive breast carcinomas of no special type (IBC-NSTs) and five neuroendocrine carcinomas (NECs). The prognostic significance of these two grading systems in breast NETs was assessed. Furthermore, the clinicopathological features were compared in Nottingham G3 cases among three entities. Targeted sequencing and immunostaining (INSM1/p53/Rb/p16) were also performed in all Nottingham G3 NETs, NECs and 10 Nottingham G3 IBC-NSTs. All Nottingham G3 NETs (9 of 69, 13.0%) fell into GEP G3 cases (20 of 69, 29.0%). Nottingham grade provided better prognostic discrimination between G1/G2 and G3 NETs than GEP grade. Among Nottingham G3 cases, there was a trend towards reduced progression-free survival (PFS) in NETs compared with IBC-NSTs (P = 0.057), and the former were more often immunoreactive for INSM1 (44.4 versus 0%, P = 0.033). Nottingham G3 NETs were all of luminal-like phenotype (P < 0.001) and exhibited less aberrant p53 patterns (11.1 versus 80.0%, P = 0.023) as well as more favourable PFS (P = 0.012) and disease-specific survival (P = 0.002) than NECs. Rb loss (4 of 5, 80%), p16 overexpression (5 of 5, 100%) and RB1 mutation (2 of 5, 40%) were observed exclusively in NECs. Based on expression data, epithelial-mesenchymal transition and KRAS signalling pathways were significantly up-regulated in Nottingham G3 NETs (P < 0.05).

CONCLUSIONS

Nottingham grade, rather than GEP grade, holds important prognostic significance in primary breast NETs. Nottingham G3 NETs represent a small proportion of breast NETs, and may demonstrate distinct clinicopathological and molecular features from other high-grade breast carcinomas with diffuse neuroendocrine markers expression.

Biomedical applications of the engineered AIEgen-lipid nanostructurein vitroandin vivo

Since the concept of aggregation-induced emission (AIE) was first coined by Tang and co-workers, AIE-active luminogens (AIEgens) have drawn widespread attention among chemists and biologists due to their unique advantages such as high fluorescence efficiency, large Stokes shift, good photostability, low background noise, and high biological visualization capabilities in the aggregated state, surpassing conventional fluorophores. A growing number of AIEgens have been engineered to possess multifunctional properties, including near-infrared emission, two-photon absorption, reactive oxygen species (ROS) generation and photothermal conversion, making them suitable for deep-tissue imaging and phototherapy. AIEgens show great potential in biomedical applicationsin vitroandin vivo. However, despite the favorable photophysical stability and ROS/heat generation capability in the aggregated state, limitations including uncontrolled size, low targeting efficiency, and unexpected dispersion in physiological environments have hindered their biomedical applications. The combination of AIEgens with lipids offers a simple, promising, and widely adopted solution to these challenges. This review article provides an overview of the synthesis methods of AIEgen-lipid nanostructures and their applications in the biomedical engineering field, aiming to serve as a guideline for developing these AIEgens-lipid nanostructures with promising biological applications.

Basal cell of origin resolves neuroendocrine-tuft lineage plasticity in cancer

Neuroendocrine and tuft cells are rare, chemosensory epithelial lineages defined by expression of ASCL1 and POU2F3 transcription factors, respectively1,2. Neuroendocrine cancers, including small cell lung cancer (SCLC), frequently display tuft-like subsets, a feature linked to poor patient outcomes3-13. The mechanisms driving neuroendocrine-tuft tumour heterogeneity, and the origins of tuft-like cancers are unknown. Using multiple genetically-engineered animal models of SCLC, we demonstrate that a basal cell of origin (but not the accepted neuroendocrine origin) generates neuroendocrine-tuft-like tumours that highly recapitulate human SCLC. Single-cell clonal analyses of basal-derived SCLC further uncovers unexpected transcriptional states and lineage trajectories underlying neuroendocrine-tuft plasticity. Uniquely in basal cells, introduction of genetic alterations enriched in human tuft-like SCLC, including high MYC, PTEN loss, and ASCL1 suppression, cooperate to promote tuft-like tumours. Transcriptomics of 944 human SCLCs reveal a basal-like subset and a tuft-ionocyte-like state that altogether demonstrate remarkable conservation between cancer states and normal basal cell injury response mechanisms14-18. Together, these data suggest that the basal cell is a plausible origin for SCLC and other neuroendocrine-tuft cancers that can explain neuroendocrine-tuft heterogeneity-offering new insights for targeting lineage plasticity.

Recent advances in immunotherapy for small cell lung cancer

PURPOSE OF REVIEW

This review aims to provide an overview of recent advances in immunotherapy for small cell lung cancer (SCLC), with a focus on the current status of immune checkpoint inhibitors (ICIs), novel combination strategies, and key biomarkers.

RECENT FINDINGS

The integration of ICIs into standard chemotherapy has established them as the first-line treatment for extensive-stage SCLC (ES-SCLC). The ADRIATIC trial further demonstrated the efficacy of ICI maintenance therapy in limited-stage SCLC. Additionally, combining radiotherapy with ICIs has shown promising synergistic effects, including the abscopal and radscopal effects. Ongoing investigations into the combination of ICIs with targeted therapies, such as antiangiogenic agents and DNA damage response inhibitors, have yielded encouraging preliminary results. Notably, the novel therapeutic agent tarlatamab, the first bispecific DLL3-directed CD3 T-cell engager, has recently received FDA approval for second-line treatment of ES-SCLC. Advances in omics technologies have shed light on the intra-tumor and inter-tumor heterogeneity of SCLC, leading to the identification of new molecular subtypes and biomarkers, thereby paving the way for precision medicine.

SUMMARY

Despite the improved outcomes associated with immunotherapy in SCLC, the overall clinical benefit remains modest. Further preclinical and clinical studies are essential to identify optimal treatment regimens and enhance therapeutic efficacy.

[Neuroendocrine carcinomas of the gastrointestinal tract : Morphology, molecular pathology, cellular origin]

Neuroendocrine carcinomas (NEC) are poorly differentiated neuroendocrine neoplasms that can occur ubiquitously in the mucosa-bearing organs of the gastrointestinal tract. Based on their morphology, they are classified into large cell (LCNEC) and small cell NEC (SCNEC). The most common form of mixed differentiation is the combination with an adenocarcinoma, referred to as mixed adenoneuroendocrine carcinoma (MANEC). NEC/MANEC exhibit a significantly poorer prognosis than the adenocarcinomas of their respective primary sites, which is inextricably linked to their typical histomorphology. Adenocarcinomas with aberrant expression of neuroendocrine markers do not show a worse clinical course. Molecularly, NEC/MANEC have a profile comparable to the adenocarcinomas of their site of origin and a profile divergent from neuroendocrine tumors. Analyses of gastric NEC/MANEC have shown frequent MYC amplifications, which are reflected in MYC signatures in various transcriptome analyses.The cellular origin of NEC remains a subject of controversial discussion. New insights are provided by a MYC-driven, genetically modified mouse model that led to the development of large gastric tumors. These tumors were histologically identified as LCNEC and were accompanied by both neuroendocrine and non-neuroendocrine precursor lesions. Using immunofluorescence, a derivation from resident neuroendocrine cells in the gastric corpus was demonstrated, suggesting that at least a portion of LCNEC may originate directly from neuroendocrine cells.

Single-cell sequencing reveals the heterogeneity of pancreatic neuroendocrine tumors under genomic instability and histological grading

Histological grading is the key factors affecting the prognosis and instructive in guiding treatment and assessing recurrence in non-functional pancreatic neuroendocrine tumor (NF-Pan-NET). Approximately one-third of patients without copy number variation (CNV) alteration and the prognosis of these patients are better than that of patients with CNV alteration. However, the difference between CNV and histological grading is unclear. Here, we analyzed the heterogeneity of tumor cells according to two classification criteria, genomic instability (including CNV alteration and tumor mutation burden) and histological grading. We revealed that the activated core pathways of tumor cells were significantly different under different histological grading's and genomic instability patterns. We also found that tip cells, lymphatic endothelial cells, macrophages, CD1A + dendritic cell, Treg, MAIT, ILC, and CAFs might participate in the process of hepatic metastases, which will facilitate the understanding of the patterns to decode the malignant potential and of NF-Pan-NET.

Splice-switching antisense oligonucleotide controlling tumor suppressor REST is a novel therapeutic medicine for neuroendocrine cancer

RNA splicing regulation has revolutionized the treatment of challenging diseases. Neuroendocrine cancers, including small cell lung cancer (SCLC) and neuroendocrine prostate cancer (PCa), are highly aggressive, with metastatic neuroendocrine phenotypes, leading to poor patient outcomes. We investigated amido-bridged nucleic acid (AmNA)-based splice-switching oligonucleotides (SSOs) targeting RE1-silencing transcription factor (REST) splicing as a novel therapy. We designed AmNA-based SSOs to alter REST splicing. Tumor xenografts were generated by subcutaneously implanting SCLC or PCa cells into mice. SSOs or saline were intraperitoneally administered and tumor growth was monitored. Blood samples were collected from mice after SSO administration, and serum alanine aminotransferase and aspartate aminotransferase levels were measured to assess hepatotoxicity using a biochemical analyser. In vitro, REST_SSO reduced cancer cell viability. In a tumor xenograft model, it exhibited significant antitumor effects. It repressed REST-controlled RE1-harboring genes and upregulated miR-4516, an SCLC biomarker. Our findings suggest that REST_SSO suppresses tumorigenesis in neuroendocrine cancers by restoring REST function. This novel therapeutic approach holds promise for intractable neuroendocrine cancers such as SCLC and neuroendocrine PCa.

[Pulmonary neuroendocrine tumors : Current review]

CLINICAL ISSUE

Neuroendocrine neoplasms of the lung are a heterogenous tumor group. The pathological classification comprises diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, classic neuroendocrine tumors, and neuroendocrine carcinoma. Classic neuroendocrine tumors include typical and atypical carcinoid tumors.

DIAGNOSTIC WORK-UP

Imaging plays an important role in diagnosis and can help in identifying the tumor biology. Overall, this tumor group is rare, comprising less than 2% of all thoracic tumors.

PRACTICAL RECOMMENDATIONS

In the current review, the various tumors are presented and important aspects regarding pathological classification, imaging modalities, and treatment are described.

Multiple bronchial carcinoids associated with Cowden syndrome

Cowden syndrome (CS) is a rare genetic condition due to the various germline mutations in the phosphatase and tensin homologue on chromosome ten (PTEN) tumour suppressor gene. As a result, CS is characterised by an increased risk of developing various benign and malignant tumours, such as thyroid, breast, endometrial and urogenital neoplasms, as well as gastrointestinal tract tumours. However, the neuroendocrine tumour association with CS is not elucidated yet. We present a case of a 46-year-old male patient diagnosed with testicular seminoma and follicular thyroid cancer in his medical history. Our patient met the clinical diagnostic criteria of Cowden syndrome. Genetic analysis established the clinical diagnosis; a known heterozygous PTEN mutation was detected [PTEN (LRG_311t1)c.388 C > T (p.Arg130Ter)]. Incidentally, he was also seen with multiple pulmonary lesions during his oncological follow-up. A video-assisted thoracoscopic left lingula wedge resection and later resections from the right lung were performed. Histological findings revealed typical pulmonary carcinoid tumours and smaller tumorlets. Somatostatin receptor SPECT-CT, 18F-FDG-PET-CT and 18F-FDOPA-PET-CT scans and endoscopy procedures could not identify any primary tumours in other locations. Our patient is the first published case of Cowden syndrome, associated with multifocal pulmonary carcinoids. Besides multiple endocrine neoplasia type 1, we propose Cowden syndrome as another hereditary condition predisposing to multiple pulmonary tumorlets and carcinoid tumours.

RN0D, a galactoglucan from Panax notoginseng flower induces cancer cell death via PINK1/Parkin mitophagy

Metabolic alterations within mitochondria, encompassing processes such as autophagy and energy metabolism, play a pivotal role in facilitating the swift proliferation, invasion, and metastasis of cancer cells. Despite this, there is a scarcity of currently available medications with proven anticancer efficacy through the modulation of mitochondrial dysfunction in a clinical setting. Here, we introduce the structural characteristics of RN0D, a galactoglucan isolated and purified from Panax notoginseng flowers, mainly composed of β-1,4-galactan and β-1,3/1,6-glucan. RN0D demonstrates the capacity to induce mitochondrial impairment in cancer cells, leading to the accumulation of reactive oxygen species, initiation of mitophagy, and reduction in both mitochondrial number and size. This sequence of events ultimately results in the inhibition of mitochondrial and glycolytic bioenergetics, culminating in the demise of cancer cells due to adenosine triphosphate (ATP) deprivation. Notably, the observed bioactivity is attributed to RN0D's direct targeting of Galectin-3, as affirmed by surface plasmon resonance studies. Furthermore, RN0D is identified as an activator of the PTEN-induced kinase 1 (PINK1)/Parkin pathway, ultimately instigating cytotoxic mitophagy in tumor cells. This comprehensive study substantiates the rationale for advancing RN0D as a potentially efficacious anticancer therapeutic.

Characterization of zinc finger protein 536, a neuroendocrine regulator, using pan-cancer analysis

BACKGROUND

Previous studies suggested that zinc finger protein 536 (ZNF536) was abundant in the central brain and regulated neuronal differentiation. However, the role of ZNF536 in cancer has remained unclear.

METHODS

ZNF536 mutation, copy number alteration, DNA methylation, and RNA expression were explored using public portals. Data from The Cancer Genome Atlas (TCGA) were utilized to analyze pathways and tumor microenvironment (TME), with a focus on prognosis in both TCGA and immunotherapy pan-cancer cohorts. Methylated ZNF536 from small cell lung cancer (SCLC) cell lines were utilized to train with probes for conducting enrichment analysis. Single-cell RNA profile demonstrated the sublocalization and co-expression of ZNF536, and validated its targets by qPCR.

RESULTS

Genetic alterations in ZNF536 were found to be high-frequency and a single sample could harbor different variations. ZNF536 at chromosome 19q12 exerted a bypass effect on CCNE1, supported by CRISPR data. For lung cancer, ZNF536 mutation was associated with longer survival in primary lung adenocarcinoma (LUAD), but its prognosis was poor in metastatic LUAD and SCLC. Importantly, ZNF536 mutation and amplification had opposite prognoses in Stand Up To Cancer-Mark Foundation (SU2C-MARK) LUAD cohort. ZNF536 mutation altered the patterns of genomic alterations in tumors, and had distinct impacts on the signaling pathways and TME compared to ZNF536 amplification. Additionally, ZNF536 expression was predominantly in endocrine tumors and brain tissues. High-dimensional analysis supported this finding and further revealed regulators of ZNF536. Considering that the methylation of ZNF536 was involved in the synaptic pathway associated with neuroendocrine neoplasms, demonstrating both diagnostic and prognostic value. Moreover, we experimentally verified ZNF536 upregulated neuroendocrine markers.

CONCLUSIONS

Our results showed that ZNF536 alterations in cancer, including variations in copy number, mutation, and methylation. We proved the involvement of ZNF536 in neuroendocrine regulation, and identified highly altered ZNF536 as a potential biomarker for immunotherapy.

The stromal microenvironment endows pancreatic neuroendocrine tumors with spatially specific invasive and metastatic phenotypes

Cancer-associated fibroblasts (CAFs) play an important role in a variety of cancers. However, the role of tumor stroma in nonfunctional pancreatic neuroendocrine tumors (NF-PanNETs) is often neglected. Profiling the heterogeneity of CAFs can reveal the causes of malignant phenotypes in NF-PanNETs. Here, we found that patients with high stromal proportion had poor prognosis, especially for that with infiltrating stroma (stroma and tumor cells that presented an infiltrative growth pattern and no regular boundary). In addition, myofibroblastic CAFs (myCAFs), characterized by FAP+ and α-SMAhigh, were spatially closer to tumor cells and promoted the EMT and tumor growth. Intriguingly, only tumor cells which were spatially closer to myCAFs underwent EMT. We further elucidated that myCAFs stimulate TGF-β expression in nearby tumor cells. Then, TGF-β promoted the EMT in adjacent tumor cells and promoted the expression of myCAFs marker genes in tumor cells, resulting in distant metastasis. Our results indicate that myCAFs cause spatial heterogeneity of EMT, which accounts for liver metastasis of NF-PanNETs. The findings of this study might provide possible targets for the prevention of liver metastasis.

Efficacy and safety of neoadjuvant therapy in gastroenteropancreatic neuroendocrine neoplasms: A systematic review and meta-analysis

OBJECTIVE

To determine the effectiveness and safety of neoadjuvant therapy in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and provide evidence-based suggestions for clinical treatment.

METHODS

The Cochrane Library, Embase, PubMed, and Web of Science were searched for articles published that analyzed the effectiveness and safety of GEP-NEN-targeted neoadjuvant therapy before March 2023. A confidence interval (CI) of 95%, a subgroup analysis, heterogeneity, and effect size (ES) were analyzed, and a meta-analysis of the literature was performed using the Stata BE17 software.

RESULTS

A total of 417 patients from 13 studies were included in this meta-analysis. The primary variables comprised the objective response rate (ORR), disease control rate (DCR), surgical resection rate, and R0 resection rate with ES values of 0.42 (95% CI: 0.25-0.60), 0.96 (95% CI: 0.93-0.99), 0.67 (95% CI: 0.50-0.84), and 0.60 (95% CI: 0.54-0.67), respectively. The secondary variables were the incidence rates of treatment-related adverse events (TRAEs), Grade 3 or higher TRAEs, and surgical complications with ES values of 0.29 (95% CI: -0.03-0.21), 0.13 (95% CI: -0.07-0.33), and 0.35 (95% CI: 0.27-0.44), respectively.

CONCLUSION

Neoadjuvant therapy is an effective and safe treatment method for GEP-NENs. However, further studies are required to determine the optimal regimen for this therapy in these tumors.

Functional Characterisation of the ATOH1 Molecular Subtype Indicates a Pro-Metastatic Role in Small Cell Lung Cancer

Molecular subtypes of Small Cell Lung Cancer (SCLC) have been described based on differential expression of transcription factors (TFs) ASCL1, NEUROD1, POU2F3 and immune-related genes. We previously reported an additional subtype based on expression of the neurogenic TF ATOH1 within our SCLC Circulating tumour cell-Derived eXplant (CDX) model biobank. Here we show that ATOH1 protein was detected in 7/81 preclinical models and 16/102 clinical samples of SCLC. In CDX models, ATOH1 directly regulated neurogenesis and differentiation programs consistent with roles in normal tissues. In ex vivo cultures of ATOH1-positive CDX, ATOH1 was required for cell survival. In vivo, ATOH1 depletion slowed tumour growth and suppressed liver metastasis. Our data validate ATOH1 as a bona fide oncogenic driver of SCLC with tumour cell survival and pro-metastatic functions. Further investigation to explore ATOH1 driven vulnerabilities for targeted treatment with predictive biomarkers is warranted.

Decoding the basis of histological variation in human cancer

Molecular abnormalities that shape human neoplasms dissociate their phenotypic landscape from that of the healthy counterpart. Through the lens of a microscope, tumour pathology optically captures such aberrations projected onto a tissue slide and has categorized human epithelial neoplasms into distinct histological subtypes based on the diverse morphogenetic and molecular programmes that they manifest. Tumour histology often reflects tumour aggressiveness, patient prognosis and therapeutic vulnerability, and thus has been used as a de facto diagnostic tool and for making clinical decisions. However, it remains elusive how the diverse histological subtypes arise and translate into pleiotropic biological phenotypes. Molecular analysis of clinical tumour tissues and their culture, including patient-derived organoids, and add-back genetic reconstruction of tumorigenic pathways using gene engineering in culture models and rodents further elucidated molecular mechanisms that underlie morphological variations. Such mechanisms include genetic mutations and epigenetic alterations in cellular identity codes that erode hard-wired morphological programmes and histologically digress tumours from the native tissues. Interestingly, tumours acquire the ability to grow independently of the niche-driven stem cell ecosystem along with these morphological alterations, providing a biological rationale for histological diversification during tumorigenesis. This Review comprehensively summarizes our current understanding of such plasticity in the histological and lineage commitment fostered cooperatively by molecular alterations and the tumour environment, and describes basic and clinical implications for future cancer therapy.

A retrospective study comparing minimally invasive versus open surgical resection of small intestinal neuroendocrine neoplasms at a tertiary referral center

INTRODUCTION

Neuroendocrine neoplasms (SI-NEN) are the commonest malignancies of the small intestine. Traditionally, surgical treatment for SI-NEN has been open surgery.

PURPOSE

The purpose of this study was to compare minimally invasive surgery (MIS) with the traditional open surgery approach for treating SI-NEN in a Swedish population.

METHODS

Patients with histopathological confirmed SI-NEN who underwent open surgery or MIS resection within 2009-2021 were extracted from the hospital's medical records.

RESULTS

65 patients were included in this study, with 35 (54 %) undergoing MIS and 30 (46 %) undergoing open surgery. We found no statistically significant difference (p = 0.173) in the frequency of R0 resections (MIS group n = 34 (97 %), open surgery group n = 26 (87 %)). Nor was there a significant difference (p = 0.101) when comparing the median number of resected lymph nodes (MIS group n = 13.5, open surgery group n = 10). A post-operative paralytic ileus was more often reported (p = 0.052) in the MIS group (n = 9, 26 %) compared to the open surgery group (n = 2, 7 %). In light of this, the days of hospital stay did not differ significantly (MIS group median = 6, IQR (5-8), open surgery group median = 6, IQR (5-9)). The Kaplan-Meier analysis did not reveal differences concerning cancer-related deaths (p = 0.109).

CONCLUSION

The results from this study support that a MIS approach for the treatment of SI-NEN may not be inferior to open surgery. The higher number of resected lymph nodes and R0 resections may even speak in favor for a MIS approach. More studies with a longer time of observation are needed to further support this conclusion.

Niacin restriction with NAMPT-inhibition is synthetic lethal to neuroendocrine carcinoma

Nicotinamide phosphoribosyltransferase (NAMPT) plays a major role in NAD biosynthesis in many cancers and is an attractive potential cancer target. However, factors dictating therapeutic efficacy of NAMPT inhibitors (NAMPTi) are unclear. We report that neuroendocrine phenotypes predict lung and prostate carcinoma vulnerability to NAMPTi, and that NAMPTi therapy against those cancers is enhanced by dietary modification. Neuroendocrine differentiation of tumor cells is associated with down-regulation of genes relevant to quinolinate phosphoribosyltransferase-dependent de novo NAD synthesis, promoting NAMPTi susceptibility in vitro. We also report that circulating nicotinic acid riboside (NAR), a non-canonical niacin absent in culture media, antagonizes NAMPTi efficacy as it fuels NAMPT-independent but nicotinamide riboside kinase 1-dependent NAD synthesis in tumors. In mouse transplantation models, depleting blood NAR by nutritional or genetic manipulations is synthetic lethal to tumors when combined with NAMPTi. Our findings provide a rationale for simultaneous targeting of NAR metabolism and NAMPT therapeutically in neuroendocrine carcinoma.

Application of machine learning algorithms to predict lymph node metastasis in gastric neuroendocrine neoplasms

Background

Neuroendocrine neoplasms (NENs) are tumors that originate from secretory cells of the diffuse endocrine system and typically produce bioactive amines or peptide hormones. This paper describes the development and validation of a predictive model of the risk of lymph node metastasis among gastric NEN patients based on machine learning platform.

Methods

In this investigation, data from 1256 patients were used, of whom 119 patients from the First Affiliated Hospital of Soochow University in China and 1137 cases from the surveillance epidemiology and end results (SEER) database were combined. Six machine learning algorithms, including the logistic regression model (LR), random forest (RF), decision tree (DT), Naive Bayes (NB), support vector machine (SVM), and k-nearest neighbor algorithm (KNN), were used to build the predictive model. The performance of the models was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

Results

Among the 1256 patients with gastric NENs, 276 patients (21.97 %) developed lymph node metastasis. T stage, tumor size, degree of differentiation, and sex were predictive factors of lymph node metastasis. The RF model achieved the best predictive performance among the six machine learning models, with an AUC, accuracy, sensitivity, and specificity of 0.81, 0.78, 0.76, and 0.82, respectively.

Conclusion

The RF model provided the best prediction and can help physicians determine the lymph node metastasis risk of gastric NEN patients to formulate individualized medical strategies.

Widespread in vivo efficacy of The-0504: A conditionally-activatable nanoferritin for tumor-agnostic targeting of CD71-expressing cancers

Background

Cancer is still among the leading causes of death all over the world. Improving chemotherapy and minimizing associated toxicities are major unmet medical needs. Recently, we provided a preliminary preclinical evaluation of a human ferritin (HFt)-based drug carrier (The-0504) that selectively delivers the wide-spectrum topoisomerase I inhibitor Genz-644282 to CD71-expressing tumors. The-0504 has so far been evaluated on four different human tumor xenotransplant models (breast, colorectal, pancreatic and liver cancers).

Methods

Herein, we extend our studies, by: (a) testing DNA damage in vitro, (b) treating eight additional tumor xenograft models in vivo with The-0504; (c) performing pharmacokinetic (PK) studies in rats; and (d) evaluating The-0504 anti-tumor xenotransplant efficacy by optimizing its administration schedule based on PK considerations.

Results

Immunofluorescence demonstrated that The-0504 induces foci expressing the DNA double-strand break marker γH2AX. Expression increases up to 4-fold and is more persistent as compared to free Genz-644282. In vivo studies confirmed a remarkable anti-tumor activity of The-0504, resulting in tumor eradication in most murine xenograft models, regardless of embryological origin (e.g. epithelial, mesenchymal or neuroendocrine), and molecular subtypes. PK studies demonstrated a long persistence of The-0504 in rat serum (half-life of about 40 h as compared to 15 h of the free drug), with a 400-fold increase in peak concentrations as compared to the free drug. On this basis, we reduced The-0504 administration frequency from twice to once per week, with no appreciable loss in therapeutic efficacy in mice.

Conclusion

The results presented here confirm that The-0504 is highly active against several human tumor xenotransplants, even when administered less frequently than previously reported. The-0504 may be a good candidate for further clinical development in a tumor histotype-agnostic setting.

Exportin 1 inhibition prevents neuroendocrine transformation through SOX2 down-regulation in lung and prostate cancers

In lung and prostate adenocarcinomas, neuroendocrine (NE) transformation to an aggressive derivative resembling small cell lung cancer (SCLC) is associated with poor prognosis. We previously described dependency of SCLC on the nuclear transporter exportin 1. Here, we explored the role of exportin 1 in NE transformation. We observed up-regulated exportin 1 in lung and prostate pretransformation adenocarcinomas. Exportin 1 was up-regulated after genetic inactivation of TP53 and RB1 in lung and prostate adenocarcinoma cell lines, accompanied by increased sensitivity to the exportin 1 inhibitor selinexor in vitro. Exportin 1 inhibition prevented NE transformation in different TP53/RB1-inactivated prostate adenocarcinoma xenograft models that acquire NE features upon treatment with the aromatase inhibitor enzalutamide and extended response to the EGFR inhibitor osimertinib in a lung cancer transformation patient-derived xenograft (PDX) model exhibiting combined adenocarcinoma/SCLC histology. Ectopic SOX2 expression restored the enzalutamide-promoted NE phenotype on adenocarcinoma-to-NE transformation xenograft models despite selinexor treatment. Selinexor sensitized NE-transformed lung and prostate small cell carcinoma PDXs to standard cytotoxics. Together, these data nominate exportin 1 inhibition as a potential therapeutic target to constrain lineage plasticity and prevent or treat NE transformation in lung and prostate adenocarcinoma.