Single-cell transcriptome reveals the heterogeneity of malignant ductal cells and the prognostic value of REG4 and SPINK1 in primary pancreatic ductal adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related deaths, with very limited therapeutic options available. This study aims to comprehensively depict the heterogeneity and identify prognostic targets for PDAC with single-cell RNA sequencing (scRNA-seq) analysis. Methods: ScRNA-seq analysis was performed on 16 primary PDAC and three adjacent lesions. A series of analytical methods were applied for analysis in cell clustering, gene profiling, lineage trajectory analysis and cell-to-cell interactions. In vitro experiments including colony formation, wound healing and sphere formation assay were performed to assess the role of makers. Results: A total of 32,480 cells were clustered into six major populations, among which the ductal cell cluster expressing high copy number variants (CNVs) was defined as malignant cells. Malignant cells were further subtyped into five subgroups which exhibited specific features in immunologic and metabolic activities. Pseudotime trajectory analysis indicated that components of various oncogenic pathways were differentially expressed along tumor progression. Furthermore, intensive substantial crosstalk between ductal cells and stromal cells was identified. Finally, genes (REG4 and SPINK1) screened out of differentially expressed genes (DEGs) were upregulated in PDAC cell lines. Silencing either of them significantly impaired proliferation, invasion, migration and stemness of PDAC cells. Conclusions: Our findings offer a valuable resource for deciphering the heterogeneity of malignant ductal cells in PDAC. REG4 and SPINK1 are expected to be promising targets for PDAC therapy.

M6A-Related Long Non-Coding RNA Displays Utility in Predicting Prognosis, Portraying the Tumor Immune Microenvironment and Guiding Immunotherapy in Pancreatic Ductal Adenocarcinoma.

N6-methyladenosine (m6A) lncRNA plays a pivotal role in cancer. However, little is known about its role in pancreatic ductal adenocarcinoma (PDAC) and its tumor immune microenvironment (TIME). Based on The Cancer Genome Atlas (TCGA) cohort, m6A-related lncRNAs (m6A-lncRNA) with prognostic value were filtered using Pearson analysis and univariate Cox regression analysis. Distinct m6A-lncRNA subtypes were divided using unsupervised consensus clustering. Least absolute shrinkage and selection operator (LASSO) Cox regression was applied to establish an m6A-lncRNA-based risk score signature. The CIBERSORT and ESTIMATE algorithms were employed to analyze the TIME. The expression pattern of TRAF3IP2-AS1 was examined using qRT-PCR. The influence of TRAF3IP2-AS1 knockdown on cell proliferation was estimated by performing CCK8, EdU and colony-formation assays. Flow cytometry was applied to measure the effect of TRAF3IP2-AS1 knockdown on cell cycle and apoptosis. The in vivo anti-tumor effect of TRAF3IP2-AS1 was validated in a tumor-bearing mouse model. Two m6A-lncRNA subtypes with different TIME features were clarified. A risk score signature was constructed as a prognostic predictor based on m6A-lncRNAs. The risk score also correlated with TIME characterization, which facilitated immunotherapy. Finally, the m6A-lncRNA TRAF3IP2-AS1 was proved to be a tumor suppressor in PDAC. We comprehensively demonstrated m6A-lncRNAs to be useful tools for prognosis prediction, TIME depiction and immunotherapeutic guidance in PDAC.

Prognostic N6-methyladenosine (m6A)-related lncRNA patterns to aid therapy in pancreatic ductal adenocarcinoma.

Background: Mounting research studies have suggested the indispensable roles of N6-methyladenosine (m6A) RNA modification in carcinogenesis. Nevertheless, it was little known about the potential function of m6A-related lncRNAs in sample clustering, underlying mechanism, and anticancer immunity of pancreatic ductal adenocarcinoma (PDAC). Methods: PDAC sample data were obtained from TCGA-PAAD project, and a total of 23 m6A regulators were employed based on published articles. Pearson correlation and univariate Cox regression were analyzed to determine m6A-related lncRNAs with prognostic significance to identify distinct m6A-related lncRNA subtypes by consensus clustering. Next, the least absolute shrinkage and selection operator (LASSO) algorithm was applied for constructing an m6A-related lncRNA scoring system, further quantifying the m6A-related lncRNA patterns in individual samples. Gene set variation analysis (GSVA) was employed to assign pathway activity estimates to individual samples. To decode the comprehensive landscape of TME, the CIBERSORT method and ESTIMATE algorithm were analyzed. The half-maximal inhibitory concentration (IC50) of chemotherapeutic agents was predicted with the R package pRRophetic. Finally, a quantitative real-time polymerase chain reaction was used to determine TRPC7-AS1 mRNA expression in PDAC. Results: Two distinct m6A-related lncRNA patterns with different clinical outcomes, TEM features, and biological enrichment were identified based on 45 prognostic m6A-related lncRNAs. The identification of m6A-related lncRNA patterns within individual samples based on risk scores contributed to revealing biological signatures, clinical outcomes, TEM characterization, and chemotherapeutic effects. A prognostic risk-clinical nomogram was constructed and confirmed to estimate m6A-related lncRNA patterns in individual samples. Finally, the biological roles of TRPC7-AS1 were revealed in PDAC. Conclusion: This work comprehensively elucidated that m6A-related lncRNA patterns served as an indispensable player in prognostic prediction and TEM features. Quantitative identification of m6A-related lncRNA patterns in individual tumors will contribute to sample stratification for further optimizing therapeutic strategies.

Strain-induced spin-gapless semiconductors and pure thermal spin-current in magnetic black arsenic-phosphorus monolayers.

Spin-gapless semiconductor (SGS) materials are regarded as the most promising candidates for ideal massless and dissipationless states towards low-power spintronic device applications. Here, we propose a spin-gapless semiconducting black arsenic-phosphorus (AsP) monolayer halogenated by chlorine (Cl) adatoms and reveal the perfect spin Seebeck effect induced by its SGS character to produce pure thermal spin-current using first-principles calculations. Our results show that Cl atoms prefer to adsorb P atoms rather than As atoms in the AsP monolayer, behaving as a ferromagnetic semiconductor. The As-adsorbed AsP monolayer as an ideal SGS material with parabolic-type energy dispersion can be utilized to realize symmetrical spin Seebeck current for perfect pure thermal spin-current even at an extremely low on-off temperature. Moreover, in-plane strain engineering can effectively manipulate the electronic structures of the P-absorbed AsP monolayer for perfect parabolic-type SGS similar to As-adsorbed AsP, and to obtain the relevant thermoelectric effect. These distinct features suggest the potential applications of the Cl-halogenated AsP monolayer with the SGS character in low-power spin-caloritronic devices.

Reversibility of hAT-MSCs phenotypic and metabolic changes after exposure to and withdrawal from HCC-conditioned medium through regulation of the ROS/MAPK/HIF-1α signaling pathway.

BACKGROUND: Mesenchymal stem cells (MSCs) play an important role in tumor progression; concomitantly, MSCs also undergo profound changes in the tumor microenvironment (TME). These changes can directly impact the application and efficacy of MSC-based anti-tumor therapy. However, few studies have focused on the regulation of MSC fate in TME, which will limit the progress of MSC-based anti-tumor therapy. Herein, we investigated the effects of conditioned medium from human hepatocellular carcinoma cells (HCC-CM) on the phenotype and glucose metabolism of human adipose tissue-derived MSCs (hAT-MSCs). METHODS: The passage 2 (P2) to passage 3 (P3) hAT-MSCs were exposed to conditioned medium from Hep3B, Huh7 and HCCLM3 cells for 4-8 weeks in vitro. Then, immunofluorescent, CCK-8 assay, EdU assay, Transwell assay, and flow cytometry were used to assess the alterations in cell phenotype in terms of cell morphology, secretory profiles, proliferation, migration, invasion, cell cycle, and apoptosis. In addition, glucose metabolism was evaluated by related kits. Next, the treated hAT-MSCs were subjected to withdrawal from HCC-CM for 2-4 weeks, and alterations in phenotype and glucose metabolism were reevaluated. Finally, the molecular mechanism was clarified by Western blotting. RESULTS: The results revealed that after exposure to HCC-CM, hAT-MSCs developed a stellate-shaped morphology. In association with cytoskeleton remodeling, hAT-MSCs showed enhanced capacities for migration and invasion, while cell proliferation was inhibited by regulating the cell cycle by downregulating cyclins and cyclin-dependent kinases and activating the mitochondrial apoptosis pathway. In terms of glucose metabolism, our results showed mitochondrial dysfunction and elevated glycolysis of hAT-MSCs. However, interestingly, when the treated hAT-MSCs were subjected to withdrawal from HCC-CM, the alterations in phenotype and glucose metabolism could be reversed, but secretory phenotype and tumor-promoting properties appear to be permanent. Further studies showed that these changes in hAT-MSCs may be regulated by the ROS/MAPK/HIF-1α signaling pathway. CONCLUSION: Taken together, the effects of long-term HCC-CM treatment on phenotype and glucose metabolism in hAT-MSCs are modest and largely reversible after withdrawal, but HCC-CM endow hAT-MSCs with permanent secretory phenotype and tumor-promoting properties. This is the first report on the reversal of phenotype and glucose metabolism in tumor-associated MSCs (TA-MSCs), it is anticipated that new insights into TA-MSCs will lead to the development of novel strategies for MSC-based anti-tumor therapy.

Melatonin Augments the Effects of Fluoxetine on Depression-Like Behavior and Hippocampal BDNF-TrkB Signaling.

Depression is a debilitating psychiatric disorder with a huge socioeconomic burden, and its treatment relies on antidepressants including selective serotonin reuptake inhibitors (SSRIs). Recently, the melatonergic system that is closely associated with the serotonergic system has been implicated in the pathophysiology and treatment of depression. However, it remains unknown whether combined treatment with SSRI and melatonin has synergistic antidepressant effects. In this study, we applied a sub-chronic restraint stress paradigm, and evaluated the potential antidepressant effects of combined fluoxetine and melatonin in adult male mice. Sub-chronic restraint stress (6 h/day for 10 days) induced depression-like behavior as shown by deteriorated fur state, increased latency to groom in the splash test, and increased immobility time in the forced-swim test. Repeated administration of either fluoxetine or melatonin at 10 mg/kg during stress exposure failed to prevent depression-like phenotypes. However, combined treatment with fluoxetine and melatonin at the selected dose attenuated stress-induced behavioral abnormalities. Moreover, we found that the antidepressant effects of combined treatment were associated with the normalization of brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling in the hippocampus, but not in the prefrontal cortex. Our findings suggest that combined fluoxetine and melatonin treatment exerts synergistic antidepressant effects possibly by restoring hippocampal BDNF-TrkB signaling.

Group cognitive-behavioral therapy in insomnia: a cross-sectional case-controlled study.

BACKGROUND: Group cognitive-behavioral therapy (GCBT) might meet the considerable treatment demand of insomnia, but its effectiveness needs to be addressed. PARTICIPANTS: This study recruited 27 insomnia patients treated with 16-weeks of zolpidem (zolpidem group), 26 patients treated with 4-weeks of zolpidem and also treated with 12-weeks of GCBT (GCBT group), and 31 healthy control volunteers. METHODS: Before treatment and 16 weeks after intervention, participants were evaluated using the Patient Health Questionnaires (Patient Health Questionnaire-9 [PHQ-9] and Patient Health Questionnaire-15 [PHQ-15]), the Dysfunctional Beliefs and Attitudes about Sleep-16 (DBAS-16), and the Pittsburgh Sleep Quality Index (PSQI). RESULTS: Compared to the zolpidem and healthy control groups, the scale scores of PHQ-9, PHQ-15, DBAS-16 and PSQI were significantly reduced after intervention in the GCBT group. Regarding the score changes, there were correlations between PSQI, DBAS-16, PHQ-9, and PHQ-15 scales in the zolpidem group, but there were limited correlations between PSQI and some DBAS-16 scales in the GCBT group. CONCLUSION: Our results indicate that GCBT is effective to treat insomnia by improving sleep quality and reducing emotional and somatic disturbances; thus, the study supports the advocacy of applying group psychotherapy to the disorder.

Development of a Body Image Concern Scale using both exploratory and confirmatory factor analyses in Chinese university students.

BACKGROUND: The body dysmorphic disorder is prevalent in general population and in psychiatric, dermatological, and plastic-surgery patients, but there lacks a structure-validated, comprehensive self-report measure of body image concerns, which is established through both exploratory and confirmatory factor analyses. METHODS: We have composed a 34-item matrix targeting the body image concerns and trialed it in 328 male and 365 female Chinese university students. Answers to the matrix dealt with treatments including exploratory factor analyses, reserve of qualified items, and confirmatory factor analyses of latent structures. RESULTS: Six latent factors, namely the Social Avoidance, Appearance Dissatisfaction, Preoccupation with Reassurance, Perceived Distress/Discrimination, Defect Hiding, and Embarrassment in Public, were identified. The factors and their respective items have composed a 24-item questionnaire named as the Body Image Concern Scale. Each factor earned a satisfactory internal reliability, and the intercorrelations between these factors were in a median level. Women scored significantly higher than men did on the Appearance Dissatisfaction, Preoccupation with Reassurance, and Defect Hiding. CONCLUSION: The Body Image Concern Scale has displayed its structure validation and gender preponderance in Chinese university students.