Genomic profiles of primary and metastatic esophageal adenocarcinoma identified via digital sorting of pure cell populations: results from a case report

Correlations between Molecular Alterations, Histopathological Characteristics, and Poor Prognosis in Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is a severe malignancy with increasing incidence, poorly understood pathogenesis, and low survival rates. We sequenced 164 EAC samples of naïve patients (without chemo-radiotherapy) with high coverage using next-generation sequencing technologies. A total of 337 variants were identified across the whole cohort, with TP53 as the most frequently altered gene (67.27%). Missense mutations in TP53 correlated with worse cancer-specific survival (log-rank p = 0.001). In seven cases, we found disruptive mutations in HNF1alpha associated with other gene alterations. Moreover, we detected gene fusions through massive parallel sequencing of RNA, indicating that it is not a rare event in EAC. In conclusion, we report that a specific type of TP53 mutation (missense changes) negatively affected cancer-specific survival in EAC. HNF1alpha was identified as a new EAC-mutated gene.

A review: Dielectrophoresis for characterizing and separating similar cell subpopulations based on bioelectric property changes due to disease progression and therapy assessment

This paper reviews the use of dielectrophoresis for high-fidelity separations and characterizations of subpopulations to highlight the recent advances in the electrokinetic field as well as provide insight into its progress toward commercialization. The role of cell subpopulations in heterogeneous clinical samples has been studied to deduce their role in disease progression and therapy resistance for instances such as cancer, tissue regeneration, and bacterial infection. Dielectrophoresis (DEP), a label-free electrokinetic technique, has been used to characterize and separate target subpopulations from mixed samples to determine disease severity, cell stemness, and drug efficacy. Despite its high sensitivity to characterize similar or related cells based on their differing bioelectric signatures, DEP has been slowly adopted both commercially and clinically. This review addresses the use of dielectrophoresis for the identification of target cell subtypes in stem cells, cancer cells, blood cells, and bacterial cells dependent on cell state and therapy exposure and addresses commercialization efforts in light of its sensitivity and future perspectives of the technology, both commercially and academically.

Targeted Sequencing of Sorted Esophageal Adenocarcinoma Cells Unveils Known and Novel Mutations in the Separated Subpopulations

INTRODUCTION

Our study aimed at investigating tumor heterogeneity in esophageal adenocarcinoma (EAC) cells regarding clinical outcomes.

METHODS

Thirty-eight surgical EAC cases who underwent gastroesophageal resection with lymph node dissection in 3 university centers were included. Archival material was analyzed via high-throughput cell sorting technology and targeted sequencing of 63 cancer-related genes. Low-pass sequencing and immunohistochemistry (IHC) were used to validate the results.

RESULTS

Thirty-five of 38 EACs carried at least one somatic mutation that was absent in the stromal cells; 73.7%, 10.5%, and 10.5% carried mutations in tumor protein 53, cyclin dependent kinase inhibitor 2A, and SMAD family member 4, respectively. In addition, 2 novel mutations were found for hepatocyte nuclear factor-1 alpha in 2 of 38 cases. Tumor protein 53 gene abnormalities were more informative than p53 IHC. Conversely, loss of SMAD4 was more frequently noted with IHC (53%) and was associated with a higher recurrence rate (P = 0.015). Only through cell sorting we were able to detect the presence of hyperdiploid and pseudodiploid subclones in 7 EACs that exhibited different mutational loads and/or additional copy number amplifications, indicating the high genetic heterogeneity of these cancers.

DISCUSSION

Selective cell sorting allowed the characterization of multiple molecular defects in EAC subclones that were missed in a significant number of cases when whole-tumor samples were analyzed. Therefore, this approach can reveal subtle differences in cancer cell subpopulations. Future studies are required to investigate whether these subclones are responsible for treatment response and disease recurrence.