Identification and validation of heterotypic cell-in-cell structure as an adverse prognostic predictor for young patients of resectable pancreatic ductal adenocarcinoma

Abstract

<jats:p>OBJECTIVES: A proportion of resectable pancreatic ductal adenocarcinoma (PDAC) patients display poorer survival due to profound local immune suppression. However, a pathological/morphological parameter that could functionally read out immune evasion and predict patient survival has not been defined. This study investigated the feasibility of heterotypic cell-in-cell (CIC) structures for immune cell cannibalism by tumor cells to serve as a parameter for survival prediction in resectable PDAC patients. METHODS: A total of 410 samples from PDAC patients were examined using the methods of "EML" multiplex staining or immunohistochemistry (IHC). Prognostic CIC candidates were initially identified in samples plotted in tissue microarray (n=300), then independently validated in specimens from the First Affiliated Hospital of Sun Yat-Sen University (n=110). The Kaplan - Meier estimator and/or the Cox regression model were used for univariate and multivariate analysis. A nomogram was made using the Regression Modeling Strategies. RESULTS: CICs were prevalent in cancerous (203/235) but not non-malignant tissues (15/147). Among the 4 CIC subtypes identified, 2 heterotypic subtypes with tumor cells internalizing CD45+ lymphocytes (LiT, mOS = 8 vs. 14.5 months, p = 0.008) or CD68+ monocytes (MiT, mOS = 7.5 vs. 15 months, p = 0.001), and overall CICs (oCIC, mOS = 10 vs. 27 months, p = 0.021), but not homotypic CICs (TiT, p = 0.089), were identified in univariate analysis as adverse prognostic factors of overall survival (OS) of PDAC. Notably, through cannibalism of immune cells by tumor cells, heterotypic CICs (L/MiT: LiT plus MiT) could independently predict shorter OS (HR = 1.85, p = 0.008) in multivariate analysis, with a performance comparable or even superior to traditional clinicopathological parameters such as histological grade (HR = 1.78, p = 0.012) and TNM stage (HR=1.64, p = 0.108). This was confirmed in the validation cohort, where L/MiT (HR = 1.71, p = 0.02) and tumor-node-metastasis (TNM) stage (HR = 1.66, p = 0.04) were shown to be independent adverse prognostic factors. Moreover, L/MiT stood out as the most prominent contributor in nomogram models constructed for survival prediction (area under the curve = 0.696 at 14 months), the dropout of which compromised prediction performance (area under the curve = 0.661 at 14 months). Furthermore, stratification analysis indicated that L/MiT tended preferentially to impact young and female patients (HR = 11.61, p &lt; 0.0001, and HR = 9.55, p = 0.0008, respectively) in particular with early-stage and low-grade PDAC (HR = 2.37, p &lt; 0.0001, and HR = 2.19, p &lt; 0.0001, respectively), while TNM stage demonstrated little preference.</jats:p>

Role of Heterotypic Neutrophil-in-Tumor Structure in the Prognosis of Patients With Buccal Mucosa Squamous Cell Carcinoma

“…Cell-in-cell (CIC) is an evolutionarily conserved cytobiological phenomenon ( 1 , 2 ), which was first reported 150 years ago by a German scholar ( 3 ). It refers to the presence of one or more living cells within another living one and has ever since been found in varieties of tumors tissues, such as breast carcinoma ( 4 , 5 ), pancreatic ductal adenocarcinoma ( 6 ), and head and neck squamous cell carcinoma (HNSCC) ( 7 ) and the like. CIC has two typical forms: one is homotypic CIC, and the other is heterotypic CIC, with the latter often occurring between tumor cells and immune cells that include neutrophils ( 8 ).…”

Role and dynamics of vacuolar pH during cell-in-cell mediated death

“…Cell-in-cell structure (CICs) refers to a unique type of cellular structure characterized by the enclosure of one or more cells into the cytosolic vacuoles of another cell. CICs had been mostly documented in various of human tumors 1,2 , such as pancreatic cancer 3,4 , head and neck squamous cell carcinoma 5,6 , and breast cancer 7,8 , where it was proposed to mediate competition between tumor cells to facilitate clonal selection and tumor evolution 9 . Meanwhile, recent studies implicated CICs in a wider range of biological processes, such as embryonic development 10 , genome stability 11,12 , virus infection 13,14 , and immune homeostasis 15,16 and the like.…”

AIM-CICs: automatic identification method for Cell-in-cell structures based on convolutional neural network

“…Cell-in-cell structures (CICs) typically referred to the unusual eukaryotic cells involving the whole objects internalized partially or completely inside of others, which had been observed in diverse physiological and pathological samples [1, 2]. The presence of CICs was reported to be correlated with patient prognosis in a group of human tumors, such as breast cancer [3], head and neck squamous carcinoma [4, 5], and pancreatic ductal adenocarcinoma [6]. Functional studies implicated CICs in a number of biomedical processes, including embryonic development [7], mitotic surveillance [8], tumor evolution [9], and immune homeostasis [10] and the forth.…”