Fangfang Zhu

Circulating tumor cells (CTCs) are tumor cells that have sloughed off the primary tumor and extravasate into and circulate in the blood. Understanding of the metastatic cascade of CTCs has tremendous potential for the identification of targets against cancer metastasis. Detecting these very rare CTCs among the massive blood cells is challenging. However, emerging technologies for CTCs detection have profoundly contributed to deepening investigation into the biology of CTCs and have facilitated their clinical application. Current technologies for the detection of CTCs are summarized herein, together with their advantages and disadvantages. The detection of CTCs is usually dependent on molecular markers, with the epithelial cell adhesion molecule being the most widely used, although molecular markers vary between different types of cancer. Properties associated with epithelial-to-mesenchymal transition and stemness have been identified in CTCs, indicating their increased metastatic capacity. Only a small proportion of CTCs can survive and eventually initiate metastases, suggesting that an interaction and modulation between CTCs and the hostile blood microenvironment is essential for CTC metastasis. Single-cell sequencing of CTCs has been extensively investigated, and has enabled researchers to reveal the genome and transcriptome of CTCs. Herein, we also review the clinical applications of CTCs, especially for monitoring response to cancer treatment and in evaluating prognosis. Hence, CTCs have and will continue to contribute to providing significant insights into metastatic processes and will open new avenues for useful clinical applications.

Macrophage-mediated programmed cell removal (PrCR) is a process essential for the clearance of unwanted (damaged, dysfunctional, aged, or harmful) cells. The detection and recognition of appropriate target cells by macrophages is a critical step for successful PrCR, but its molecular mechanisms have not been delineated. Here using the models of tissue turnover, cancer immunosurveillance, and hematopoietic stem cells, we show that unwanted cells such as aging neutrophils and living cancer cells are susceptible to "labeling" by secreted calreticulin (CRT) from macrophages, enabling their clearance through PrCR. Importantly, we identified asialoglycans on the target cells to which CRT binds to regulate PrCR, and the availability of such CRT-binding sites on cancer cells correlated with the prognosis of patients in various malignancies. Our study reveals a general mechanism of target cell recognition by macrophages, which is the key for the removal of unwanted cells by PrCR in physiological and pathophysiological processes.

OBJECTIVES: Severe acute respiratory distress syndrome is complicated with coronavirus disease 2019 and extracorporeal membrane oxygenation support may be necessary in severe cases. This study is to summarize the clinical features, extracorporeal membrane oxygenation characteristics, and outcomes of patients with severe acute respiratory syndrome coronavirus 2 pneumonia received extracorporeal membrane oxygenation. DESIGN: Descriptive study from two hospitals. SETTING: The ICUs from university hospitals. PATIENTS: Patients with severe acute respiratory syndrome coronavirus 2 pneumonia received mechanical ventilation, including those underwent extracorporeal membrane oxygenation from Zhongnan Hospital of Wuhan University and Wuhan Pulmonary Hospital from January 8, 2020, to March 31, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Clinical records, laboratory results, ventilator parameters, and extracorporeal membrane oxygenation-related data were abstracted from the medical records. One-hundred twenty-nine critically ill patients with severe acute respiratory syndrome coronavirus 2 pneumonia were admitted to ICU of the two referral hospitals. Fifty-nine patients received mechanical ventilation and 21 of them received extracorporeal membrane oxygenation support (fourteen from Zhongnan hospital and seven from Wuhan pulmonary hospital). Compared to mechanical ventilation patients without extracorporeal membrane oxygenation support, there was a tendency of decline in mortality but with no significant difference (no-extracorporeal membrane oxygenation group 24/38 [63.2%] vs extracorporeal membrane oxygenation group 12/21 [57.1%]; p = 0.782). For those patients with extracorporeal membrane oxygenation, 12 patients died and nine survived by April 7, 2020. Among extracorporeal membrane oxygenation patients, the PaCO2 prior to extracorporeal membrane oxygenation was lower (54.40 mm Hg [29.20-57.50 mm Hg] vs 63.20 mm Hg [55.40-72.12 mm Hg]; p = 0.006), and pH prior to extracorporeal membrane oxygenation was higher (7.38 [7.28-7.48] vs 7.23 [7.16-7.33]; p = 0.023) in survivors than nonsurvivors. CONCLUSIONS: Extracorporeal membrane oxygenation might be an effective salvage treatment for patients with severe acute respiratory syndrome coronavirus 2 pneumonia associated with severe acute respiratory distress syndrome. Severe CO2 retention and acidosis prior to extracorporeal membrane oxygenation indicated a poor prognosis.