Single-cell RNA sequencing reveals cellular and molecular reprograming landscape of gliomas and lung cancer brain metastases.

BACKGROUND: Brain malignancies encompass gliomas and brain metastases originating from extracranial tumours including lung cancer. Approximately 50% of patients with lung adenocarcinoma (LUAD) will eventually develop brain metastases. However, the specific characteristics of gliomas and lung-to-brain metastases (LC) are largely unknown. METHODS: We applied single-cell RNA sequencing to profile immune and nonimmune cells in 4 glioma and 10 LC samples. RESULTS: Our analysis revealed that tumour microenvironment (TME) cells are present in heterogeneous subpopulations. LC reprogramed cells into immune suppressed state, including microglia, macrophages, endothelial cells, and CD8+ T cells, with unique cell proportions and gene signatures. Particularly, we identified that a subset of macrophages was associated with poor prognosis. ROS (reactive oxygen species)-producing neutrophils was found to participant in angiogenesis. Furthermore, endothelial cells participated in active communication with fibroblasts. Metastatic epithelial cells exhibited high heterogeneity in chromosomal instability (CIN) and cell population. CONCLUSIONS: Our findings provide a comprehensive understanding of the heterogenicity of the tumor microenvironment and tumour cells and it will be crucial for successful immunotherapy development for brain metastasis of lung cancer.

Exonuclease 1 (EXO1) is a Potential Prognostic Biomarker and Correlates with Immune Infiltrates in Lung Adenocarcinoma.

BACKGROUND: Exonuclease 1 (EXO1) has been identified to be highly expressed in different human malignancies, but its expression and prognostic role in lung adenocarcinoma (LUAD) remain unknown. MATERIALS AND METHODS: Two independent cohorts extracted from public databases and one cohort from our center were analyzed in this study. Expression levels of EXO1 in LUAD tissues and paired para-cancer tissues were detected. The prognostic value of EXO1 in LUAD patients was evaluated in the three cohorts. Enrichment analyses were performed to explore the possible underlying biological pathways. Moreover, we also explored the correlations between EXO1 and tumor-infiltrating immune cells and evaluated the impact of EXO1 knock-down on the migration of lung cancer cells. RESULTS: In this study, we found that EXO1 was highly expressed in LUAD tissues compared with para-cancerous tissues in public databases (p < 0.01), which was consistent with our data (p < 0.01). Survival analysis indicated that high expression of EXO1 was associated with poor prognosis in LUAD (p < 0.01). Enrichment analyses indicated that biological pathways like cell cycle regulation, DNA damage and repair, immune response, neuroactive ligand-receptor interaction, may be associated with EXO1 aberrant expression. Moreover, high expression of EXO1 was correlated with decreased infiltrating B cells (p < 0.01) and CD4+ T cells (p < 0.01) levels, and low infiltrating levels of B cells (p < 0.01) and dendritic cells (DCs) (p < 0.05) indicated poor overall survival (OS) in LUAD. Additionally, in vitro experiments suggested that knockdown of EXO1 may inhibit the migratory ability of lung cancer cells. CONCLUSION: In conclusion, EXO1 is a potential prognostic biomarker in LUAD, and correlates with infiltrating levels of immune cells in the tumor microenvironment. Further prospective validation of EXO1 in lung cancer is warranted.

A FXYD5/TGF­ß/SMAD positive feedback loop drives epithelial­to­mesenchymal transition and promotes tumor growth and metastasis in ovarian cancer.

Epithelial ovarian cancer is aggressive and lacks effective prognostic indicators or therapeutic targets. In the present study, using immunohistochemistry and bioinformatics analysis on ovarian cancer tissue data from The Obstetrics and Gynecology Hospital of Fudan University and The Cancer Genome Atlas database, it was identified that FXYD domain­containing ion transport regulator 5 (FXYD5) expression was upregulated in the SKOV3­IP cell line compared with its parental cell line, SKOV3, and in ovarian cancer tissues compared with in normal tissues. In addition, FXYD5 upregulation was predictive of poor patient survival. Furthermore, through various in vitro (Transwell assay, clonogenic assay and western blot analysis) and in vivo (nude mouse model) experiments, it was demonstrated that FXYD5 promoted the metastasis of ovarian cancer cells. Mechanistically, RNA sequencing, western blot analysis, a luciferase reporter assay and chromatin immunoprecipitation were performed to reveal that FXYD5 dispersed the SMAD7­SMAD specific E3 ubiquitin protein ligase 2­TGF­ß receptor 1 (TßR1) complex, deubiquitinated and stabilized TßR1, and subsequently enhanced transforming growth factor­ß (TGF­ß) signaling and sustained TGF­ß­driven epithelial­mesenchymal transition (EMT). The TGF­ß­activated SMAD3/SMAD4 complex was in turn directly recruited to the FXYD5 promoter region, interacted with specific SMAD­binding elements, and then promoted FXYD5 transcription. In brief, FXYD5 positively regulated TGF­ß/SMADs signaling activities, which in turn induced FXYD5 expression, creating a positive feedback loop to drive EMT in the process of ovarian cancer progression. Collectively, the findings of the present study suggested a mechanism through which FXYD5 serves a critical role in the constitutive activation of the TGF­ß/SMADs signaling pathways in ovarian cancer, and provided a promising therapeutic target for human ovarian cancer.

Prognostic values of S100 family members in ovarian cancer patients.

OBJECTIVE: Exhibiting high consistence in sequence and structure, S100 family members are interchangeable in function and they show a wide spectrum of biological processes, including proliferation, apoptosis, migration, inflammation and differentiation and the like. While the prognostic value of each individual S100 in ovarian cancer is still elusive. In current study, we investigated the prognostic value of S100 family members in the ovarian cancer. METHODS: We used the Kaplan Meier plotter (KM plotter) database, in which updated gene expression data and survival information are from 1657 ovarian cancer patients, to assess the relevance of individual S100 family mRNA expression to overall survival in various ovarian cancer subtypes and different clinicopathological features. RESULTS: It was found that high expression of S100A2 (HR = 1.18, 95%CI: 1.04-1.34, P = 0.012), S100A7A (HR = 1.3, 95%CI: 1.04-1.63, P = 0.02),S100A10 (HR = 1.2, 95%CI: 1.05-1.38, P = 0.0087),and S100A16 (HR = 1.23, 95%CI: 1-1.51, P = 0.052) were significantly correlated with worse OS in all ovarian cancer patients, while the expression of S100A1 (HR = 0.87, 95%CI: 0.77-0.99, P = 0.039), S100A3 (HR = 0.83, 95%CI: 0.71-0.96, P = 0.0011), S100A5 (HR = 0.84, 95%CI: 0.73-0.97, P = 0.017), S100A6 (HR = 0.84, 95%CI: 0.72-0.98, P = 0.024), S100A13 (HR = 0.85, 95%CI:0.75-0.97, P = 0.014) and S100G (HR = 0.86, 95%CI: 0.74-0.99, P = 0.041) were associated with better prognosis. Furthermore, we assessed the prognostic value of S100 expression in different subtypes and the clinicopathological features, including pathological grades, clinical stages and TP53 mutation status, of ovarian cancer patients. CONCLUSION: Comprehensive understanding of the S100 family members may have guiding significance for the diagnosis and outcome of ovarian cancer patients.

Downregulation of FOXP2 promotes breast cancer migration and invasion through TGFß/SMAD signaling pathway.

Cancer metastasis and relapse are the primary cause of mortality for patients with breast cancer. The present study performed quantitative proteomic analysis on the differentially expressed proteins between highly metastatic breast cancer cells and parental cells. It was revealed that forkhead box P2 (FOXP2), a transcription factor in neural development, may become a potential inhibitor of breast cancer metastasis. The results demonstrated that patients with a lower level of FOXP2 expression had significantly poorer relapse-free survival (P=0.0047). The transcription of FOXP2 was also significantly downregulated in breast cancer tissue compared with normal breast tissue (P=0.0005). In addition, FOXP2 may inhibit breast cancer cell migration and invasion in vitro. It was also revealed that the underlying mechanism may include the epithelial-mesenchymal transition process driven by the tumor growth factor ß/SMAD signaling pathway. In conclusion, the present study identified FOXP2 as a novel suppressor and prognostic marker of breast cancer metastasis. These results may provide further insight into breast cancer prevention and the development of novel treatments.

Clinicopathological characteristics and survival outcomes in Paget disease: a SEER population-based study.

The objective of this study was to investigate the clinicopathological characteristics and survival outcomes of Paget disease (PD), Paget disease concomitant infiltrating duct carcinoma (PD-IDC), and Paget disease concomitant intraductal carcinoma (PD-DCIS). We identified 501,631 female patients from 2000 to 2013 in the Surveillance, Epidemiology, and End Results (SEER) database. These identified patients included patients with PD (n = 469), patients with PD-IDC (n = 1832), and patients with PD-DCIS (n = 1130) and infiltrating ductal carcinoma (IDC) (n = 498,076). Then, we compared the clinical characteristics of these patients with those who were diagnosed with IDC during the same period. The outcomes of these subtypes of breast carcinoma were different. Based on the overall survival, the patients with PD-IDC had the worst prognosis (5-year survival rate = 84.1%). The PD-DCIS had the best prognosis (5-year survival rate = 97.5%). Besides, among patients with Paget disease, the one who was married had a better prognosis than who were not. And, according to our research, the marital status was associated with the hormone receptor status in patients with PD-IDC. Among three subtypes of Paget disease, patients with PD-IDC had the worst prognosis. Besides, patients who were unmarried had worse outcomes. And the marital status of patients with PD-IDC is associated with hormone status. The observation underscores the importance of individualized treatment.

Clinicopathological characteristics and survival outcomes of male breast cancer according to race: A SEER population-based study.

To investigate the clinicopathological characteristics and survival outcomes of breast cancer in the male population, 8,607 cases of patients were identified in the Surveillance, Epidemiology, and End Results (SEER) database, including white males (n = 7122), black males (n = 1111), and other males (American Indian/AK Native, Asian/Pacific Islander) (n = 374). Black male breast cancer patients were more likely to be in stages II-IV and have more advanced tumors. The rate of lymph node (LN) involvement at diagnosis was higher in black men than in whites and others. The ER- and PR-positive rates were lower in black men than in whites and others. The distant metastasis rate was higher in blacks than in whites and others. Furthermore, the overall survival (OR) rates and breast cancer-specific survival rates were significantly poorer in blacks than in whites and others (χ2 = 29.974, P < 0.001; χ2 = 7.285, P = 0.026, respectively). In a multivariate analysis, the results showed that race could also be a prognostic indicator (P < 0.001). Moreover, significant differences were also observed in OS among 1:1:1 matched white, black, and other groups (P < 0.001). Differences in outcomes may be partially explained by differences in tumor grades, LN status, and ER and PR status between the 3 groups. This study might provide insights into a better understanding of male breast cancer.

Comparison of patterns and prognosis among distant metastatic breast cancer patients by age groups: a SEER population-based analysis.

To investigate the effects of age at diagnosis on metastatic breast cancer and patients' prognosis, we collected patient data from the Surveillance, Epidemiology, and End Results (SEER) database. We finally identified 4932 eligible metastatic breast cancer patients diagnosed between 2010-2013, including 850 younger patients (<50 years), 2,540 middle-aged patients (50-69 years) and 1,542 elder patients (>69 years). The results revealed that in stage IV patients, elder patients were more likely to have lung metastasis (P < 0.001) and less likely to have only distant lymphatic spread (P = 0.004). Higher proportion of younger (34.9%) and middle-aged (36.2%) patients had multiple metastatic sites than elder patients (28.3%) (P < 0.001). In survival analysis, younger patients presented the best prognosis, while elder patients had the worst both in overall survival (χ2 = 121.9, P < 0.001) and breast cancer-specific survival (χ2 = 69.8, P < 0.001). Age at diagnosis was an independent prognostic factor for metastatic breast cancer patients. Moreover, patients with bone metastasis only had superior survival compared to other metastatic patients (P < 0.001). Brain metastasis only group and multiple sites metastasis group had the poorest prognosis (P < 0.05). We hope the results will provide insights into a better understanding of distant metastatic breast cancer.

UHRF1 promotes breast cancer progression by suppressing KLF17 expression by hypermethylating its promoter.

UHRF1 is an epigenetic regulator and perform pivotal functions in cell tumorigenesis. We found UHRF1 is increased in breast cancer and patients with high UHRF1 levels have poorer prognoses than those with low UHRF1 levels. However, the underlying mechanisms remain largely unknown. Here, we found overexpression UHRF1 indeed promoted cell proliferation and migration, whereas its downregulation had the opposite functions. In vivo, UHRF1 also accelerated tumor growth. Mechanistically, microarrays were performed in MDA-MB-231 sh-UHRF1 and NC cells and KLF17, with rich CpG islands on its promoter region, finally caused our attention. Then, the expression of UHRF1 and KLF17 was testified negatively correlated in breast cancer cell lines and tissues. Additionally, the inhibition of cell proliferation and migration by UHRF1 depletion can be rescued by KLF17 silencing, suggesting KLF17 is downstream gene of UHRF1. The potential mechanism is that overexpression UHRF1 increased methylation of CpG nucleotides on KLF17 promoter, while UHRF1 silence decreased methylation. Collectively, our results demonstrated that increased UHRF1 can promote breast cancer cell proliferation and migration via silencing of KLF17 expression through CpG island methylation on its promoter.

High expression of COX5B is associated with poor prognosis in breast cancer.

BACKGROUND: Cytochrome c oxidase subunit VB (COX5B), a subunit of mammalian COX, takes roles in COX assembling and functions. Online database predicts high COX5B transcription may be associated with worse disease-free survival (DFS). However, the clinical implications of COX5B in breast cancer remain unclear. METHODS: We carried out immunohistochemistry on tissue microarrays of 244 patients with invasive ductal breast carcinoma to detected COX5B expression. RESULTS: Our results suggest that COX5B protein level might be associated with tumor size. COX5B overexpression indicated a worse DFS (p < 0.05) in breast cancer. Furthermore, high COX5B expression may act as an independent factor for worse DFS in breast cancer. CONCLUSIONS: Cumulatively, our findings suggest that COX5B might serve as an important prognostic factor for breast cancer.

Targeting of topoisomerases for prognosis and drug resistance in ovarian cancer.

BACKGROUD: As magicians of the DNA world, topoisomerases resolve all of the topological problems in relation to DNA during a variety of genetic processes. While the prognostic value of topoisomerase isoenzymes in epithelial ovarian carcinoma (EOC) is still elusive. In current study, we investigated the prognostic value of topoisomerase isoenzymes in the EOC patients. Kaplan Meier plotter (KM plotter) database were used to assess the relevance of individual topoisomerase isoenzyme mRNA expression to EOC patients overall survival (OS), in which updated survival information and gene expression data were from a total of 1,648 EOC patients. RESULTS: High expression of TOP1 and TOP2A were found to be correlated to worse OS in all patients and serous patients, but not in endometrioid patients. Contrary to TOP1 and TOP2A, TOP3A and TOP3B expression were associated with better OS in all patients and serous patients, but not in endometrioid patients. While TOP2B were not found any significant prognostic value for EOC patients. From the Oncomine database, we also found widespread upregulation in the expression of TOP1 and TOP2A genes in primary tumor tissues. Albeit limited in number, all datasets exhibiting differential expression showed TOP3A and TOP3B under-regulated. CONCLUSION: These results strongly supported that TOP1 and TOP2A were potential biomarkers for predicting poor survival of EOC patients, while TOP3A and TOP3B were expected to be further exploited as tumor suppressors. Comprehensive understanding of the topoisomerase isoforms may have guiding significance for the diagnosis treatment and prognosis in EOC patients.

Loss of TIM50 suppresses proliferation and induces apoptosis in breast cancer.

TIM50 is an essential component of TIM23 complex and involved in protein translocating into the inner mitochondrial membrane. Here, we found that TIM50 was increased in breast cancer cells by SILAC. However, its biological functions and molecular mechanisms in breast cancer are poorly understood. To gain insight into the functions of TIM50 in breast cancer, we constructed two stably transfected cell lines and examined TIM50 expression in tissue samples. Our data showed that TIM50 expression was increased in breast cancer. The stable suppression of TIM50 expression through lentivirus-mediated shRNA was shown to inhibit the abilities of cancer cell proliferation and induce apoptosis. What is more, depletion of TIM50 could decrease mitochondrial membrane potential, which may be associated with cell viability. Taken together, our findings reveal a new role for TIM50 in regulating cell proliferation and apoptosis through decreasing mitochondrial membrane potential in breast cancer cell and suggest that TIM50 might be a potential target for controlling breast cancer progression.

SSBP1 Suppresses TGFß-Driven Epithelial-to-Mesenchymal Transition and Metastasis in Triple-Negative Breast Cancer by Regulating Mitochondrial Retrograde Signaling.

Triple-negative breast cancer (TNBC) is a highly aggressive tumor subtype lacking effective prognostic indicators or therapeutic targets. Mitochondrial function is dysregulated frequently in cancer cells to allow for adaptation to a harsh tumor microenvironment. Targeting mitochondrial biogenesis and bioenergetics is, therefore, an attractive therapeutic strategy. In this study, we performed quantitative proteomic analyses in human parental and metastatic breast cancer cell lines to identify mitochondrial proteins involved in TNBC metastasis. We found that single-strand DNA-binding protein 1 (SSBP1) was downregulated in highly metastatic breast cancer cells. Moreover, SSBP1 downregulation promoted TNBC cell metastasis in vitro and in vivo. Mechanistically, SSBP1 loss decreased mitochondrial DNA copy number, thereby potentiating calcineurin-mediated mitochondrial retrograde signaling that induced c-Rel/p50 nuclear localization, activated TGFß promoter activity, and TGFß-driven epithelial-to-mesenchymal transition. Low SSBP1 expression correlated with tumor progression and poor prognosis in patients. Collectively, our findings identified SSBP1 as a novel metastasis suppressor and elucidated the mechanisms by which dysregulated mitochondrial signaling contributes to metastatic potential, providing potential new prognostic indicators for patients with TNBC.

Down-Regulation of NDUFB9 Promotes Breast Cancer Cell Proliferation, Metastasis by Mediating Mitochondrial Metabolism.

Despite advances in basic and clinical research, metastasis remains the leading cause of death in breast cancer patients. Genetic abnormalities in mitochondria, including mutations affecting complex I and oxidative phosphorylation, are found in breast cancers and might facilitate metastasis. Genes encoding complex I components have significant breast cancer prognostic value. In this study, we used quantitative proteomic analyses to compare a highly metastatic cancer cell line and a parental breast cancer cell line; and observed that NDUFB9, an accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (complex I), was down-regulated in highly metastatic breast cancer cells. Furthermore, we demonstrated that loss of NDUFB9 promotes MDA-MB-231 cells proliferation, migration, and invasion because of elevated levels of mtROS, disturbance of the NAD+/NADH balance, and depletion of mtDNA. We also showed that, the Akt/mTOR/p70S6K signaling pathway and EMT might be involved in this mechanism. Thus, our findings contribute novel data to support the hypothesis that misregulation of mitochondrial complex I NADH dehydrogenase activity can profoundly enhance the aggressiveness of human breast cancer cells, suggesting that complex I deficiency is a potential and important biomarker for further basic research or clinical application.

Loss of COX5B inhibits proliferation and promotes senescence via mitochondrial dysfunction in breast cancer.

COX5B, a peripheral subunit of the cytochrome c oxidase complex, has previously been reported to maintain the stability of this complex. However, its functions and mechanisms involved in breast cancer progression remain unclear. Here, by performing SILAC assays in breast cancer cell models and detecting COX5B expression in tissues, we found that COX5B expression was elevated in breast cancer. Down-regulation of COX5B in breast cancer cell lines can suppress cell proliferation and induced cell senescence which was accompanied by elevating production of IL-8 and other cytokines. Interestingly, conditioned medium from COX5B knockdown cells could promote breast cancer cell migration. Mechanistic studies reveal that COX5B silence induces an increase in production of ROS, depolarization of MMP and a decrease in ATP. What's more, silence of COX5B leads to metabolic disorders, such as increased glucose uptake and decreased lactate secretion. Collectively, our study shows that loss of COX5B induces mitochondrial dysfunction and subsequently leads to cell growth suppression and cell senescence. Cytokines such as IL-8 secreted by senescent cells may in turn alter the microenvironment which could enhance cell migration. These findings may provide a novel paradigm for the treatment which combined anti-cancer drugs with particular cytokine inhibitors such as IL-8 blockers.

Loss of RAB1B promotes triple-negative breast cancer metastasis by activating TGF-ß/SMAD signaling.

Triple-negative breast cancer (TNBC) is a highly aggressive tumor subtype associated with a poor prognosis. The mechanism involved in TNBC progression remains largely unknown. To date, there are no effective therapeutic targets for this tumor subtype. In this study, by performing quantitative proteomic analyses in highly metastatic and parental breast cancer cell line, we found that RAB1B, a member of the RAS oncogene family, was significantly down-regulated in highly metastatic breast cancer cells. Moreover, down-regulation of RAB1B was also found to promote the proliferation and migration of TNBC cells in vitro and in vivo. Mechanistically, loss of RAB1B resulted in elevated expression of TGF-ß receptor 1 (TßR1) through decreased degradation of ubiquitin, increased levels of phosphorylated SMAD3 and TGF-ß-induced epithelial-mesenchymal transition (EMT). Furthermore, low RAB1B expression correlated with poor prognosis in breast cancer patients. Taken together, our findings reveal that RAB1B acts as a metastasis suppressor in TNBC by regulating the TGF-ß/SMAD signaling pathway and RAB1B may serve as a novel biomarker of prognosis and the response to anti-tumor therapeutics for patients with TNBC.