Upregulated delta-like protein 3 expression is a diagnostic and prognostic marker in endometrial cancer: A retrospective study

Identification of DLL3-related genes affecting the prognosis of patients with colon adenocarcinoma

Background: Delta-like ligand 3 (DLL3) is one of the NOTCH family of ligands, which plays a pro- or anti-carcinogenic role in some cancers. But the role of DLL3 in colon adenocarcinoma (COAD) has not been studied in depth. Materials and methods: First, we used Kaplan-Meier (K-M) curve to evaluate the effect of DLL3 on the prognosis of COAD in The Cancer Genome Atlas (TCGA), which was further validated in clinical samples for immunohistochemistry. Then we screened for differentially expressed genes (DEGs) of DLL3 by analyzing datasets of COAD samples from Gene Expression Omnibus (GEO) and TCGA. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and Gene Set Enrichment Analysis (GSEA) were conducted to explore the underlying mechanisms of DLL3-related in the development and prognosis of COAD. On the basis of DLL3-related signature genes, a prognostic model and a nomogram were constructed. Finally, CIBERSORT was applied to assess the proportion of immune cell types in COAD sample. Results: Survival analysis showed a significant difference in overall survival between high- and low-expression group (p = 0.0092), with COAD patients in the high-group having poorer 5-year survival rate. Gene functional enrichment analysis revealed that DLL3-related DEGs were mainly enriched in tumor- and immunity-related signaling pathways, containing AMPK pathway and mitophagy-animal. The comparison of COAD tumor and normal, DLL3 high- and low-expression groups by GSEA found that AMPK signaling pathway and mitophagy-animal were inhibited. Nomogram constructed from DLL3-related signature genes had a good predictive effect on the prognosis of COAD. We found the highest correlation between DLL3 and interstitial dendritic cell (iDC), natural killer (NK) cell and Interstitial dendritic cell (Tem). DLL3 was also revealed to be diagnostic for COAD. In clinical sample, we identified higher DLL3 expression in colon cancer tissue than in adjacent control (p < 0.0001) and in metastasis than in primary lesion (p = 0.0056). DLL3 expression was associated with stage and high DLL3 expression was observed to predict poorer overall survival (p = 0.004). Conclusion: It suggested that DLL3 may offer prognostic value and therapeutic potential for individualized treatment of COAD, and that it may has a diagnostic role in COAD.

Targeting the DLL/Notch Signaling Pathway in Cancer: Challenges and Advances in Clinical Development

The DLL/Notch signaling pathway plays an important role in cancer as a key driver in maintaining cancer stemness and inducing tumor angiogenesis. Many different types of DLL/Notch inhibitors have been developed and explored in clinical trials for cancer treatment, including small-molecule compounds to inhibit gamma-secretase and antibodies targeting Notch ligands or receptors. Despite promising efficacy of these inhibitors in preclinical studies, the overall clinical outcomes have been insufficient to advance to the next stage of clinical development primarily due to safety concerns or modest efficacy. To overcome the narrow therapeutic window of DLL/Notch inhibitors, diverse strategies for improving the balance between the safety and efficacy are currently being explored. Here, we review the clinical perspective and potential of DLL/Notch inhibitors as anticancer agents based on recent results from multiple clinical studies. An antibody specifically targeting Notch ligands or receptors may offer a better approach to reduce concerns about toxicity derived from broad-spectrum DLL/Notch blockers. In addition, combination therapy with an angiogenesis inhibitor targeting VEGF could be a better option for increasing anticancer efficacy. Taken together, the results of clinical trials suggest a bispecific antibody blocking the DLL/Notch and VEGF/VEGFR signaling pathways as a promising approach for effective anticancer treatment.

Role of Leptin and Adiponectin in Endometrial Cancer

Endometrial cancer is the most common malignancy of the female genital tract. Obesity is a strong risk factor for endometrial cancer. Adipose tissue is an active endocrine organ that synthesizes biologically active cytokine peptides, called adipokines. Adiponectin and leptin are the main cytokines of adipose tissue, which may influence the development of metabolic diseases and carcinogenesis. In this scenario, we describe the role of leptin and adiponectin in the development of endometrial cancer. A better understanding of the signalling pathway of these cytokines in endometrial cancerogenesis will provide an opportunity for effective target therapy and may be usable in fertility-sparing treatment. In the future, clinical trials focusing on adipokines, molecular biology, and genetics of the tumour will be needed.

Prevalence of Delta-Like Protein 3 in a Consecutive Series of Surgically Resected Lung Neuroendocrine Neoplasms

Delta-like protein 3 (DLL3) is a protein of the Notch pathway, and it is a potential therapeutic target for high-grade lung neuroendocrine tumors (NETs), i.e., small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC). However, DLL3 prevalence in lung NETs and its association with clinicopathological characteristics and prognosis remained unclear. We analyzed the immunohistochemical expression of DLL3 and its prognostic role in a consecutive series of 155 surgically resected lung NETs, including typical carcinoid (TC), atypical carcinoid (AC), LCNEC, and SCLC patients. The DLL3 expression was categorized as high (>50% positive tumor cells) or low (<50%). In addition, tumors were categorized by H-score (i.e., percentage of positive cells by staining intensity, ≥150 vs. <150). DLL3 staining was positive in 99/155 (64%) samples, and high DLL3 expression was frequently observed in high-grade tumors. In detail, 46.9% and 75% of SCLC and 48.8% and 53.7% of LCNEC specimens showed a high DLL3 expression by using H-score and percentage of positive tumor cells, respectively. Regarding low-grade NETs, only 4.9% and 12.2% TCs and 19.5% and 24.4% ACs had high DLL3 expression considering H-score and percentage of positive tumor cells, respectively. High DLL3 expression was associated with advanced American Joint Committee on Cancer (AJCC) stage, peripheral location, and chromogranin A expression in high-grade tumors (p < 0.05). In low-grade NETs, high DLL3 expression was associated with female sex, peripheral location, a higher number of mitoses, higher Ki-67 index, presence of necrosis, and pleural infiltration (p < 0.05). No association was observed between high DLL3 expression and overall survival (OS) and disease-free survival (DFS) in high-grade NETs, whereas high DLL3 expression was associated with lower DFS in ACs (p = 0.01). In conclusion, our study demonstrated a high prevalence of DLL3 expression in high-grade lung NET patients and its association with aggressive clinicopathological features. These findings confirm that DLL3 could represent a useful biomarker for target therapy in high-grade tumors. Our results also suggest that the DLL3 expression could identify a subset of AC tumors with more aggressive behavior, thus providing the basis for new therapeutic options in this group of patients.

Delta-like canonical Notch ligand 3 as a potential therapeutic target in malignancies: A brief overview

Delta‐like canonical Notch ligand 3 (DLL3) is a member of the Delta/Serrate/Lag2 (DSL) Notch receptor ligand family and plays a crucial role in Notch signaling, which influences various cellular processes including differentiation, proliferation, survival, and apoptosis. DLL3 is expressed throughout the presomitic mesoderm and is localized to the rostral somatic compartments; mutations in DLL3 induce skeletal abnormalities such as spondylocostal dysostosis. Recently, DLL3 has attracted interest as a novel molecular target due to its high expression in neuroendocrine carcinoma of the lung. Moreover, a DLL3‐targeting Ab‐drug conjugate, rovalpituzumab tesirine (ROVA‐T), has been developed as a new treatment with proven antitumor activity. However, the development of ROVA‐T was suspended because of shorter overall survival compared to topotecan, the second‐line standard treatment. Thus, several studies on the mechanism and function of DLL3 in several malignancies are underway to find a new strategy for targeting DLL3. In this review, we discuss the roles of DLL3 in various malignancies and the future perspectives of DLL3‐related research, especially as a therapeutic target.

Notch and Endometrial Cancer

The human endometrium is a unique, highly dynamic tissue that undergoes cyclic changes of cell proliferation, differentiation, and death. Endometrial cancer is the most common malignancy among women in developed countries. Importantly, the incidence of endometrial cancer is rising in high-income countries. Currently histological classification is used for subtyping of endometrial cancer, while ongoing research is evaluating markers for more accurate molecular classification. Evolutionary conserved Notch signaling pathway regulates diverse cellular processes such as proliferation, differentiation, and cell invasion. Accumulating evidence links aberrant Notch signaling with diseases such as hyperplasia and endometrial cancer. This chapter summarizes the current state of Notch signaling investigations in the endometrium, endometriosis, and endometrial cancer.

A Novel Six-Gene Signature for Prognosis Prediction in Ovarian Cancer

Ovarian cancer (OC) is the most malignant tumor in the female reproductive tract. Although abundant molecular biomarkers have been identified, a robust and accurate gene expression signature is still essential to assist oncologists in evaluating the prognosis of OC patients. In this study, samples from 367 patients in The Cancer Genome Atlas (TCGA) database were subjected to mRNA expression profiling. Then, we used a gene set enrichment analysis (GSEA) to screen genes correlated with epithelial–mesenchymal transition (EMT) and assess their prognostic power with a Cox proportional regression model. Six genes (TGFBI, SFRP1, COL16A1, THY1, PPIB, BGN) associated with overall survival (OS) were used to construct a risk assessment model, after which the patients were divided into high-risk and low-risk groups. The six-gene signature was an independent prognostic biomarker of OS for OC patients based on the multivariate Cox regression analysis. In addition, the six-gene model was validated with samples from the Gene Expression Omnibus (GEO) database. In summary, we established a six-gene signature relevant to the prognosis of OC, which might become a therapeutic tool with clinical applications in the future.

Potential prognostic value of delta-like protein 3 in small cell lung cancer: a meta-analysis

BACKGROUND

Current researches have revealed that delta-like protein 3 (DLL3) may be related with prognosis in patients with small cell lung cancer (SCLC). However, this finding remains controversial in small cell lung cancer. This meta-analysis was systematically performed to evaluate the prognostic value of DLL3 in SCLC.

METHODS

The PubMed, EMBASE and Web of Science databases were retrieved to collect the eligible references. Through Stata 15.0 software, we pooled hazard ratios (HR) with 95% confidence intervals (CI) by using random or fixed-effects models to evaluate the association between DLL3 and SCLC survival results.

RESULTS

A total of 6 inter-related studies including 645 patients were qualified. After we removed 1 study, the remaining 5 studies including 601 patients were pooled to testify that high expression of DLL3 was an inferior prognostic for patients with SCLC in Asian populations (HR = 1.37, 95% CI = 1.05, 1.69; I² = 0.0%, p = 0.000). The pooled results showed that DLL3 might be higher expression in advanced metastasis SCLC in Asian populations (RR = 0.84, 95% CI = 0.71, 0.99; I² = 44.7%, p = 0.039). But the expression of DLL3 was not correlated with sex (RR = 1.33, 95% CI = 0.98, 1.80; I² = 0.0%, p = 0.064), smoking history (RR = 1.01, 95% CI = 0.58, 1.75; I² = 72.1%, p = 0.967) and tumour stage (RR = 0.68, 95% CI = 0.44, 1.05; I² = 66.6%, p = 0.081).

CONCLUSIONS

Our meta-analysis confirms that in Asian populations, high expression of DLL3 was a potential poor prognostic biomarker for SCLC and DLL3 highly expressed in advanced stage SCLC in Asian populations.

The Role of DLLs in Cancer: A Novel Therapeutic Target

Delta-like ligands (DLLs) control Notch signaling. DLL1, DLL3 and DLL4 are frequently deregulated in cancer and influence tumor growth, the tumor vasculature and tumor immunity, which play different roles in cancer progression. DLLs have attracted intense research interest as anti-cancer therapeutics. In this review, we discuss the role of DLLs in cancer and summarize the emerging DLL-relevant targeting methods to aid future studies.

Expression of delta-like protein 3 is reproducibly present in a subset of small cell lung carcinomas and pulmonary carcinoid tumors

OBJECTIVES

Delta-like protein 3 (DLL3), an inhibitory Notch ligand, is the target for rovalpituzumab tesirine in development for the treatment of small cell lung cancer (SCLC). We studied the expression of DLL3, its reproducibility and prognostic role in pulmonary neuroendocrine tumors.

MATERIALS AND METHODS

Institutional pathology files were searched for resected pulmonary neuroendocrine tumors (1995-2017). Expression of DLL3 (clone SP347) was categorized as high (≥50% of tumor cells) or low (<50%). Interobserver agreement among 5 thoracic pathologists was measured by Krippendorff's α coefficient. Staging (N = 148) was performed according to the 8th AJCC.

RESULTS

Our study included 157 patients with a median age of 62.2 years (range 23.2-88.1) including 59 men (37.6%). Tumors included 44 (28.0%) SCLC, 46 (29.3%) atypical and 67 (42.7%) typical carcinoid tumors at stages I (N = 83, 56.1%), II (N = 28, 18.9%), and III/IV (N = 37, 25.0%). Interobserver agreement for high vs low DLL3 expression (N = 70) was 82.9% (α = 0.79, substantial). High DLL3 expression was observed in 35 (79.5%) SCLC, 17 (37.0%) atypical and 22 (32.8%) typical carcinoid tumors. High DLL3 was associated with SCLC morphology (p < 0.0001). During a median follow-up of 4.2 years (range, 2 days-20.3 years), 70 patients died; 19 died from disease. High DLL3 expression was associated with better overall survival in SCLC (p = 0.049) but not after adjusting for age, tumor size and stage.

CONCLUSIONS

DLL3 expression is reliably quantifiable by pathologists and is highly expressed in the majority of SCLC and a subset of carcinoid tumors, making it an attractive target for anti-DLL3 treatment.