Autopsy analysis reveals increased macrophage infiltration and cell apoptosis in COVID-19 patients with severe pulmonary fibrosis.

Clinical data indicates that SARS-CoV-2 infection-induced respiratory failure is a fatal condition for severe COVID-19 patients. However, the pathological alterations of different types of respiratory failure remained unknown for severe COVID-19 patients. This study aims to evaluate whether there are differences in the performance of various types of respiratory failure in severe COVID-19 patients and investigate the pathological basis for these differences. The lung tissue sections of severe COVID-19 patients were assessed for the degree of injury and immune responses. Transcriptome data were used to analyze the molecular basis in severe COVID-19 patients. Severe COVID-19 patients with combined oxygenation and ventilatory failure presented more severe pulmonary fibrosis, airway obstruction, and prolonged disease course. The number of M2 macrophages increased with the degree of fibrosis in patients, suggesting that it may be closely related to the development of pulmonary fibrosis. The co-existence of pro-inflammatory and anti-inflammatory cytokines in the pulmonary environment could also participate in the progression of pulmonary fibrosis. Furthermore, the increased apoptosis in the lungs of COVID-19 patients with severe pulmonary fibrosis may represent a critical factor linking sustained inflammatory responses to fibrosis. Our findings indicate that during the extended phase of COVID-19, antifibrotic and antiapoptotic treatments should be considered in conjunction with the progression of the disease.

COVID-19-associated monocytic encephalitis (CAME): histological and proteomic evidence from autopsy.

Severe neurological symptoms are associated with Coronavirus disease 2019 (COVID-19). However, the morphologic features, pathological nature and their potential mechanisms in patient brains have not been revealed despite evidence of neurotropic infection. In this study, neuropathological damages and infiltrating inflammatory cells were quantitatively evaluated by immunohistochemical staining, ultrastructural examination under electron microscopy, and an image threshold method, in postmortem brains from nine critically ill COVID-19 patients and nine age-matched cadavers of healthy individuals. Differentially expressed proteins were identified by quantitative proteomic assays. Histopathological findings included neurophagocytosis, microglia nodules, satellite phenomena, extensive edema, focal hemorrhage, and infarction, as well as infiltrating mononuclear cells. Immunostaining of COVID-19 brains revealed extensive activation of both microglia and astrocytes, severe damage of the blood-brain barrier (BBB) and various degrees of perivascular infiltration by predominantly CD14+/CD16+/CD141+/CCR7+/CD11c+ monocytes and occasionally CD4+/CD8+ T lymphocytes. Quantitative proteomic assays combined with bioinformatics analysis identified upregulated proteins predominantly involved in immune responses, autophagy and cellular metabolism in COVID-19 patient brains compared with control brains. Proteins involved in brain development, neuroprotection, and extracellular matrix proteins of the basement membrane were downregulated, potentially caused by the activation of transforming growth factor ß receptor and vascular endothelial growth factor signaling pathways. Thus, our results define histopathological and molecular profiles of COVID-19-associated monocytic encephalitis (CAME) and suggest potential therapeutic targets.

A map of the spatial distribution and tumour-associated macrophage states in glioblastoma and grade 4 IDH-mutant astrocytoma.

Tumour-associated macrophages (TAMs) abundantly infiltrate high-grade gliomas and orchestrate immune response, but their diversity in isocitrate dehydrogenase (IDH)-differential grade 4 gliomas remains largely unknown. This study aimed to dissect the transcriptional states, spatial distribution, and clinicopathological significance of distinct monocyte-derived TAM (Mo-TAM) and microglia-derived TAM (Mg-TAM) clusters across glioblastoma-IDH-wild type and astrocytoma-IDH-mutant-grade 4 (Astro-IDH-mut-G4). Single-cell RNA sequencing was performed on four cases of human glioblastoma and three cases of Astro-IDH-mut-G4. Cell clustering, single-cell regulatory network inference, and gene set enrichment analysis were performed to characterize the functional states of myeloid clusters. The spatial distribution of TAM subsets was determined in human glioma tissues using multiplex immunostaining. The prognostic value of different TAM-cluster specific gene sets was evaluated in the TCGA glioma cohort. Profiling and unbiased clustering of 24,227 myeloid cells from glioblastoma and Astro-IDH-mut-G4 identified nine myeloid cell clusters including monocytes, six Mo/Mg-TAM subsets, dendritic cells, and proliferative myeloid clusters. Different Mo/Mg-TAM clusters manifest functional and transcriptional diversity controlled by specific regulons. Multiplex immunostaining of subset-specific markers identified spatial enrichment of distinct TAM clusters at peri-vascular/necrotic areas in tumour parenchyma or at the tumour-brain interface. Glioblastoma harboured a substantially higher number of monocytes and Mo-TAM-inflammatory clusters, whereas Astro-IDH-mut-G4 had a higher proportion of TAM subsets mediating antigen presentation. Glioblastomas with a higher proportion of monocytes exhibited a mesenchymal signature, increased angiogenesis, and worse patient outcome. Our findings provide insight into myeloid cell diversity and its clinical relevance in IDH-differential grade 4 gliomas, and may serve as a resource for immunotherapy development. © 2022 The Pathological Society of Great Britain and Ireland.

Spatial region-resolved proteome map reveals mechanism of COVID-19-associated heart injury.

Direct myocardial and vascular injuries due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven inflammation is the leading cause of acute cardiac injury associated with coronavirus disease 2019 (COVID-19). However, in-depth knowledge of the injury characteristics of the heart affected by inflammation is lacking. In this study, using a quantitative spatial proteomics strategy that combines comparative anatomy, laser-capture microdissection, and histological examination, we establish a region-resolved proteome map of the myocardia and microvessels with obvious inflammatory cells from hearts of patients with COVID-19. A series of molecular dysfunctions of myocardia and microvessels is observed in different cardiac regions. The myocardia and microvessels of the left atrial are the most susceptible to virus infection and inflammatory storm, suggesting more attention should be paid to the lesion and treatment of these two parts. These results can guide in improving clinical treatments for cardiovascular diseases associated with COVID-19.

Dicer deficiency impairs proliferation but potentiates anti-tumoral effect of macrophages in glioblastoma.

Glioblastoma is a lethal primary brain tumor with abundant immune-suppressive glioblastoma-associated macrophage (GAM) infiltration. Skewing immune suppressive GAMs towards an immune-activating phenotype represents a promising immunotherapeutic strategy against glioblastoma. Herein, we reported that genetic deletion of miRNA-processing enzyme Dicer in macrophages inhibited the growth of GL261 murine glioblastoma xenografts and prolonged survival of tumor-bearing mice. Single cell RNA sequencing (scRNA-seq) of the tumor-infiltrating immune cells revealed that Dicer deletion in macrophages reduced the proportion of cell-cycling GAM cluster and reprogramed the remaining GAMs towards a proinflammatory activation state (enhanced phagocytotic and IFN-producing signature). Dicer-deficient GAMs showed reduced level of cyclin-dependent kinases (CDK1 and CDK2) and increased expression of CDK inhibitor p27 Kip1, thus manifesting impaired proliferation. Dicer knockout enhanced phagocytotic activity of GAMs to eliminate GL261 tumor cells. Increased proinflammatory GAM clusters in macrophage Dicer-deficient mice actively interacted with tumor-infiltrating T cells and NK cells through TNF paracrine signaling to create a pro-inflammatory immune microenvironment for tumor cell elimination. Our work identifies the role of Dicer deletion in macrophages in generating an immune-activating microenvironment, which could be further developed as a potential immunotherapeutic strategy against glioblastoma.

HOXA5 is amplified in glioblastoma stem cells and promotes tumor progression by transcriptionally activating PTPRZ1.

Although the tumorigenic potential of glioma stem cells (GSCs) is associated with multiple molecular alterations, the gene amplification status of GSCs has not been elucidated. Overexpression of HomeoboxA5 (HOXA5) is associated with increased glioma malignancy. In this study, we identify the gene amplification and protein overexpression of HOXA5 in GSCs and its function in regulating GSC maintenance and the downstream transcriptional effector, to explore the significance of HOXA5 amplification/overexpression for GSC identification and prognostic determination. The HOXA5 gene is significantly amplified in glioblastoma (GBM) and is an independent prognostic factor for predicting worse patient outcomes. Specifically, HOXA5 gene amplification and the resultant protein overexpression are correlated with increased proportions of GSCs and enhanced self-renewal/invasiveness of these cells. Disruption of HOXA5 expression impairs GSC survival and GBM tumor propagation. Mechanistically, HOXA5 directly binds to the promoter region of protein tyrosine phosphatase receptor type Z1 (PTPRZ1), thereby upregulating this gene for GSC maintenance. Suppression of PTPRZ1 largely compromises the pro-tumoral effect of HOXA5 on GSCs. In summary, HOXA5 amplification serves as a genetic biomarker for predicting worse GBM outcome, by enhancing PTPRZ1-mediated GSC survival.

Overexpression of carnitine palmitoyltransferase 1A promotes mitochondrial fusion and differentiation of glioblastoma stem cells.

Glioma stem cells (GSCs) are self-renewing tumor cells with multi-lineage differentiation potential and the capacity of construct glioblastoma (GBM) heterogenicity. Mitochondrial morphology is associated with the metabolic plasticity of GBM cells. Previous studies have revealed distinct mitochondrial morphologies and metabolic phenotypes between GSCs and non-stem tumor cells (NSTCs), whereas the molecules regulating mitochondrial dynamics in GBM cells are largely unknown. Herein, we report that carnitine palmitoyltransferase 1A (CPT1A) is preferentially expressed in NSTCs, and governs mitochondrial dynamics and GSC differentiation. Expressions of CPT1A and GSC marker CD133 were mutually exclusive in human GBMs. Overexpression of CPT1A inhibited GSC self-renewal but promoted mitochondrial fusion. In contrast, disruption of CPT1A in NSTCs promoted mitochondrial fission and reprogrammed NSTCs toward GSC feature. Mechanistically, CPT1A overexpression increased the phosphorylation of dynamin-related protein 1 at Ser-637 to promote mitochondrial fusion. In vivo, CPT1A overexpression decreased the percentage of GSCs, impaired GSC-derived xenograft growth and prolonged tumor-bearing mice survival. Our work identified CPT1A as a critical regulator of mitochondrial dynamics and GSC differentiation, indicating that CPT1A could be developed as a molecular target for GBM cell-differentiation strategy.

Calcyphosine promotes the proliferation of glioma cells and serves as a potential therapeutic target.

Calcyphosine (CAPS) was initially identified from the canine thyroid. It also exists in many types of tumor, but its expression and function in glioma remain unknown. Here we explored the clinical significance and the functional mechanisms of CAPS in glioma. We found that CAPS was highly expressed in glioma and high expression of CAPS was correlated with poor survival, in glioma patients and public databases. Cox regression analysis showed that CAPS was an independent prognostic factor for glioma patients. Knockdown of CAPS suppressed the proliferation, whereas overexpression of CAPS promoted the proliferation of glioma both in vitro and in vivo. CAPS regulated the G2/M phase transition of the cell cycle, but had no obvious effect on apoptosis. CAPS affected PLK1 phosphorylation through interaction with MYPT1. CAPS knockdown decreased p-MYPT1 at S507 and p-PLK1 at S210. Expression of MYPT1 S507 phosphomimic rescued PLK1 phosphorylation and the phenotype caused by CAPS knockdown. The PLK1 inhibitor volasertib enhanced the therapeutic effect of temozolomide in glioma. Our data suggest that CAPS promotes the proliferation of glioma by regulating the cell cycle and the PLK1 inhibitor volasertib might be a chemosensitizer of glioma. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Pericytes augment glioblastoma cell resistance to temozolomide through CCL5-CCR5 paracrine signaling.

Glioblastoma (GBM) is a prevalent and highly lethal form of glioma, with rapid tumor progression and frequent recurrence. Excessive outgrowth of pericytes in GBM governs the ecology of the perivascular niche, but their function in mediating chemoresistance has not been fully explored. Herein, we uncovered that pericytes potentiate DNA damage repair (DDR) in GBM cells residing in the perivascular niche, which induces temozolomide (TMZ) chemoresistance. We found that increased pericyte proportion correlates with accelerated tumor recurrence and worse prognosis. Genetic depletion of pericytes in GBM xenografts enhances TMZ-induced cytotoxicity and prolongs survival of tumor-bearing mice. Mechanistically, C-C motif chemokine ligand 5 (CCL5) secreted by pericytes activates C-C motif chemokine receptor 5 (CCR5) on GBM cells to enable DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-mediated DDR upon TMZ treatment. Disrupting CCL5-CCR5 paracrine signaling through the brain-penetrable CCR5 antagonist maraviroc (MVC) potently inhibits pericyte-promoted DDR and effectively improves the chemotherapeutic efficacy of TMZ. GBM patient-derived xenografts with high CCL5 expression benefit from combined treatment with TMZ and MVC. Our study reveals the role of pericytes as an extrinsic stimulator potentiating DDR signaling in GBM cells and suggests that targeting CCL5-CCR5 signaling could be an effective therapeutic strategy to improve chemotherapeutic efficacy against GBM.

A cohort autopsy study defines COVID-19 systemic pathogenesis.

Severe COVID-19 disease caused by SARS-CoV-2 is frequently accompanied by dysfunction of the lungs and extrapulmonary organs. However, the organotropism of SARS-CoV-2 and the port of virus entry for systemic dissemination remain largely unknown. We profiled 26 COVID-19 autopsy cases from four cohorts in Wuhan, China, and determined the systemic distribution of SARS-CoV-2. SARS-CoV-2 was detected in the lungs and multiple extrapulmonary organs of critically ill COVID-19 patients up to 67 days after symptom onset. Based on organotropism and pathological features of the patients, COVID-19 was divided into viral intrapulmonary and systemic subtypes. In patients with systemic viral distribution, SARS-CoV-2 was detected in monocytes, macrophages, and vascular endothelia at blood-air barrier, blood-testis barrier, and filtration barrier. Critically ill patients with long disease duration showed decreased pulmonary cell proliferation, reduced viral RNA, and marked fibrosis in the lungs. Permanent SARS-CoV-2 presence and tissue injuries in the lungs and extrapulmonary organs suggest direct viral invasion as a mechanism of pathogenicity in critically ill patients. SARS-CoV-2 may hijack monocytes, macrophages, and vascular endothelia at physiological barriers as the ports of entry for systemic dissemination. Our study thus delineates systemic pathological features of SARS-CoV-2 infection, which sheds light on the development of novel COVID-19 treatment.

Correction: miR-1260b, mediated by YY1, activates KIT signaling by targeting SOCS6 to regulate cell proliferation and apoptosis in NSCLC.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Exosome-mediated transfer of miR-1260b promotes cell invasion through Wnt/ß-catenin signaling pathway in lung adenocarcinoma.

Increasing evidence confirms that exosome-mediated transfer of microRNAs can influence cancer progression including tumor cell invasion, cell proliferation, and drug resistance via cell-cell communication. However, the potential role of exosomal-miR-1260b in lung adenocarcinoma (LAC) remains poorly understood. Thus, this study focused on investigating the function of exosomal-miR-1260b on cell invasion. Exosomal-miR-1260b was found to be higher in plasma of patients with LAC than that of healthy persons via quantitative real-time polymerase chain reaction assay. The sensitivity and specificity of exosomal-miR-1260b (cutoff point: 2.027) were 72% and 86%, and area under the curve of 0.845 (95% CI = 0.772-0.922). Elevated expression of miR-1260b in LAC tissues was positively correlated with exosomal-miR-1260b in plasma (r = .642, p < .05). Furthermore, ceramide biosynthesis regulated exosomal-miR-1260b secretion. Exosome-mediated transfer of miR-1260b promoted A549 cell invasion and was still functional inside A549 cells. Moreover, exosomal-miR-1260b regulated Wnt/ß-catenin signaling pathway by inhibiting sFRP1 and Smad4. This study identified a new regulation mechanism involving in cell invasion by exosome-mediated tumor-cell-to-tumor-cell communication. Targeting exosome-microRNAs may provide new insights into the diagnosis and treatment of LAC.

miR-1260b, mediated by YY1, activates KIT signaling by targeting SOCS6 to regulate cell proliferation and apoptosis in NSCLC.

Non-small cell lung cancer (NSCLC) is one of the most common aggressive malignancies. miRNAs have been identified as important biomarkers and regulators of NSCLC. However, the functional contributions of miR-1260b to NSCLC cell proliferation and apoptosis have not been studied. In this study, miR-1260b was upregulated in NSCLC plasma, tissues, and cell lines, and its high expression was correlated with tumor size and progression. Functionally, miR-1260b overexpression promoted cell proliferation and cell cycle, conversely inhibited cell apoptosis and senescence. Mechanically, miR-1260b negatively regulated SOCS6 by directly binding to its 3'-UTR. Furthermore, miR-1260b-mediated suppression of SOCS6 activated KIT signaling. Moreover, YY1 was an upstream regulator of miR-1260b. This study is the first to illustrate that miR-1260b, mediated by YY1, activates KIT signaling by targeting SOCS6 to regulate NSCLC cell proliferation and apoptosis, and is a potential biomarker and therapeutic target for NSCLC. In sum, our work provides new insights into the molecular mechanisms of NSCLC involved in cell proliferation and apoptosis.

Three-dimensional navigation-guided thoracoscopic combined subsegmentectomy for intersegmental pulmonary nodules.

BACKGROUND: Extended or combined segmentectomies are usually adapted for intersegmental pulmonary nodules. This study explored precise combined subsegmentectomy (CSS) under the guidance of three-dimensional computed tomography bronchography and angiography (3D-CTBA). METHODS: The definition of a pulmonary intersegmental nodule was based on a minimum distance between the nodule and the involved intersegmental veins in the preoperative 3D-CTBA being less than the size of the nodule. Centering on the involved intersegmental vein, two adjacent subsegments belonging to the different segments were combined as a resected unit. RESULTS: We retrospectively reviewed the records of 47 patients (mean age 53.6 ± 12.3, range: 26-81 years) who underwent CSS. Thirty-nine (83.0%) nodules were involved in most intersegmental locations of the upper lobes; the remainder in the lower lobes. The mean nodule size was 0.86 ± 0.32 cm; the mean margin width was 2.20 ± 0.38 cm. Pathological stages included: Tis (8 cases), T1mi (16), IA1 (T1aN0M0, 13), and IA2 (T1bN0M0, 5). Pathological diagnoses included: invasive adenocarcinoma (18 cases), minimally invasive adenocarcinoma (16), adenocarcinoma in situ (8), atypical adenomatous hyperplasia (3), and benign (2). The average operative duration was 190.8 ± 54.9 minutes; operative hemorrhage was 42.7 ± 23.0 mL; 5.8 ± 2.8 lymph nodes dissected had not metastasized; the duration of postoperative chest tube drainage was 3.0 ± 1.8 days; and the postoperative hospital stay was 5.3 ± 2.4 days. CONCLUSIONS: Under 3D navigation, thoracoscopic CSS is a safe technique for intersegmental nodules, sparing more pulmonary parenchyma and ensuring safe margins to achieve anatomical resection.

VDAC2 interacts with PFKP to regulate glucose metabolism and phenotypic reprogramming of glioma stem cells.

Plastic phenotype convention between glioma stem cells (GSCs) and non-stem tumor cells (NSTCs) significantly fuels glioblastoma heterogeneity that causes therapeutic failure. Recent progressions indicate that glucose metabolic reprogramming could drive cell fates. However, the metabolic pattern of GSCs and NSTCs and its association with tumor cell phenotypes remain largely unknown. Here we found that GSCs were more glycolytic than NSTCs, and voltage-dependent anion channel 2 (VDAC2), a mitochondrial membrane protein, was critical for metabolic switching between GSCs and NSTCs to affect their phenotypes. VDAC2 was highly expressed in NSTCs relative to GSCs and coupled a glycolytic rate-limiting enzyme platelet-type of phosphofructokinase (PFKP) on mitochondrion to inhibit PFKP-mediated glycolysis required for GSC maintenance. Disruption of VDAC2 induced dedifferentiation of NSTCs to acquire GSC features, including the enhanced self-renewal, preferential expression of GSC markers, and increased tumorigenicity. Inversely, enforced expression ofVDAC2 impaired the self-renewal and highly tumorigenic properties of GSCs. PFK inhibitor clotrimazole compromised the effect of VDAC2 disruption on glycolytic reprogramming and GSC phenotypic transition. Clinically, VDAC2 expression inversely correlated with glioma grades (Immunohistochemical staining scores of VDAC2 were 4.7 ± 2.8, 3.2 ± 1.9, and 1.9 ± 1.9 for grade II, grade III, and IV, respectively, p < 0.05 for all) and the patients with high expression of VDAC2 had longer overall survival than those with low expression of VDAC2 (p = 0.0008). In conclusion, we demonstrate that VDAC2 is a new glycolytic regulator controlling the phenotype transition between glioma stem cells and non-stem cells and may serves as a new prognostic indicator and a potential therapeutic target for glioma patients.

Microvascular fractal dimension predicts prognosis and response to chemotherapy in glioblastoma: an automatic image analysis study.

The microvascular profile has been included in the WHO glioma grading criteria. Nevertheless, microvessels in gliomas of the same WHO grade, e.g., WHO IV glioblastoma (GBM), exhibit heterogeneous and polymorphic morphology, whose possible clinical significance remains to be determined. In this study, we employed a fractal geometry-derived parameter, microvascular fractal dimension (mvFD), to quantify microvessel complexity and developed a home-made macro in Image J software to automatically determine mvFD from the microvessel-stained immunohistochemical images of GBM. We found that mvFD effectively quantified the morphological complexity of GBM microvasculature. Furthermore, high mvFD favored the survival of GBM patients as an independent prognostic indicator and predicted a better response to chemotherapy of GBM patients. When investigating the underlying relations between mvFD and tumor growth by deploying Ki67/mvFD as an index for microvasculature-normalized tumor proliferation, we discovered an inverse correlation between mvFD and Ki67/mvFD. Furthermore, mvFD inversely correlated with the expressions of a glycolytic marker, LDHA, which indicated poor prognosis of GBM patients. Conclusively, we developed an automatic approach for mvFD measurement, and demonstrated that mvFD could predict the prognosis and response to chemotherapy of GBM patients.

Large Intergenic Non-coding RNA-RoR Inhibits Aerobic Glycolysis of Glioblastoma Cells via Akt Pathway.

Reprogramming energy metabolism is a hallmark of malignant tumors, including glioblastoma (GBM). Aerobic glycolysis is often utilized by tumor cells to maintain survival and proliferation. However, the underlying mechanisms of aerobic glycolysis in GBM remain elusive. Herein, we demonstrated that large intergenic non-coding RNA-RoR (LincRNA-RoR) functioned as a critical suppressor to inhibit the aerobic glycolysis and viability of GBM cells. We found that LincRNA-RoR was markedly reduced in GBM tissues compared with adjacent non-tumor tissues from 10 cases of GBM patients. Consistently, LincRNA-RoR expression in GBM cells was significantly lower than that in normal glial cells. The aerobic glycolysis of GBM cells, as determined by the measurement of glucose uptake and lactate production, was impaired by LincRNA-RoR overexpression. Mechanistically, LincRNA-RoR inhibited the expression of Rictor, the key component of mTORC2 (mammalian target of rapamycin complex 2), to suppress the activity of Akt pathway and impair the expression of glycolytic effectors, including Glut1, HK2, PKM2 and LDHA. Finally, enforced expression of LincRNA-RoR reduced the proliferation of GBM cells in vitro, restrained tumor growth in vivo, and repressed the expression of glycolytic molecules in GBM xenografts. Collectively, our results underscore LincRNA-RoR as a new suppressor of GBM aerobic glycolysis with therapeutic potential.

Tamoxifen enhances stemness and promotes metastasis of ERα36+ breast cancer by upregulating ALDH1A1 in cancer cells.

The 66 kDa estrogen receptor alpha (ERα66) is the main molecular target for endocrine therapy such as tamoxifen treatment. However, many patients develop resistance with unclear mechanisms. In a large cohort study of breast cancer patients who underwent surgery followed by tamoxifen treatment, we demonstrate that ERα36, a variant of ERα66, correlates with poor prognosis. Mechanistically, tamoxifen directly binds and activates ERα36 to enhance the stemness and metastasis of breast cancer cells via transcriptional stimulation of aldehyde dehydrogenase 1A1 (ALDH1A1). Consistently, the tamoxifen-induced stemness and metastasis can be attenuated by either ALDH1 inhibitors or a specific ERα36 antibody. Thus, tamoxifen acts as an agonist on ERα36 in breast cancer cells, which accounts for hormone therapy resistance and metastasis of breast cancer. Our study not only reveals ERα36 as a stratifying marker for endocrine therapy but also provides a promising therapeutic avenue for tamoxifen-resistant breast cancer.

Stanniocalcin-1 augments stem-like traits of glioblastoma cells through binding and activating NOTCH1.

Glioblastoma (GBM) is a fatal tumor and comprises heterogeneous cells in which a subpopulation with stem cell-like properties is included. Cancer cells with stem cell-like properties account for tumor initiation, drug resistance and recurrence. To identify and characterize specific factors in regulating stem-like traits is critical for GBM therapeutic. Here, we showed that Stanniocalcin-1 (STC1), a secretory glycoprotein, functions as a novel stimulator for stem-like traits of GBM cells. We found STC1 was prominently expressed in glioma spheres which are mainly comprised of glioma stem-like cells. The stem-like traits of GBM cells, as determined by the expression of stem cell markers, tumor-sphere formation efficiency and colony-forming ability, were enhanced by STC1 overexpression and inhibited by STC1 knockdown. Furthermore, introduction of STC1 enhanced tumorigenesis in vivo while knockdown of STC1 showed reverse effect. Finally, we demonstrated that STC1 interacted with the extracellular domain of NOTCH1 to activate NOTCH1-SOX2 signaling pathway, by which STC1 augmented the stem-like traits of GBM cells. Taken together, our data herein indicate that STC1 is a novel non-canonical NOTCH ligand and acts as a crucial regulator of stemness in GBM.