PCSK5 downregulation promotes the inhibitory effect of andrographolide on glioblastoma through regulating STAT3.

Proprotein convertase subtilisin/kexin type 5 (PCSK5) is a member of the proprotein convertase (PC) family, which processes immature proteins into functional proteins and plays an important role in the process of cell migration and transformation. Andrographolide is a non-peptide compound with PC inhibition and antitumor activity. Our research aimed to investigate the functional role of PCSK5 downregulation combined with Andro on GBM progression. Results from the cancer genome atlas (TCGA) and clinical samples revealed a significant upregulation of PCSK5 in GBM tissues than in non-tumor brain tissues. Higher expression of PCSK5 was correlated with advanced GBM stages and worse patient prognosis. PCSK5 knockdown attenuated the epithelial-mesenchymal transition (EMT)-like properties of GBM cells induced by IL-6. PCSK5 knockdown in combination with Andro treatment significantly inhibited the proliferation and invasion of GBM cells in vitro, as well as tumor growth in vivo. Mechanistically, PCSK5 downregulation reduced the expression of p-STAT3 and Matrix metalloproteinases (MMPs), which could be rescued by the p-STAT3 agonist. STAT3 silencing downregulated the expression of MMPs without affecting PCSK5. Furthermore, Andro in combination with PCSK5 silencing significantly inhibited STAT3/MMPs axis. These observations provided evidence that PCSK5 functioned as a potential tumor promoter by regulating p-STAT3/MMPs and the combination of Andro with PCSK5 silencing might be a good strategy to prevent GBM progression.

Downregulation of MAL2 inhibits breast cancer progression through regulating ß-catenin/c-Myc axis.

PURPOSE: Myelin and lymphocyte protein 2 (MAL2) is mainly involved in endocytosis under physiological conditions and mediates the transport of materials across the membranes of cell and organelle. It has been reported that MAL2 is significantly upregulated in diverse cancers. This study aimed to investigate the role of MAL2 in breast cancer (BC). METHODS: Bioinformatics analysis and Immunohistochemical assay were applied to detect the correlation between MAL2 expression in breast cancer tissues and the prognosis of breast cancer patients. Functional experiments were carried out to investigate the role of MAL2 in vitro and in vivo. The molecular mechanisms involved in MAL2-induced ß-catenin and c-Myc expression and ß-catenin/c-Myc-mediated enhancement of BC progression were confirmed by western blot, ß-catenin inhibitor and agonist, Co-IP and immunofluorescence colocalization assays. RESULTS: Results from the cancer genome atlas (TCGA) and clinical samples confirmed a significant upregulation of MAL2 in BC tissues than in adjacent non-tumor tissues. High expression of MAL2 was associated with worse prognosis. Functional experiments demonstrated that MAL2 knockdown reduced the migration and invasion associating with EMT, increased the apoptosis of BC cells in vitro and reduced the metastatic capacity in vivo. Mechanistically, MAL2 interacts with ß-catenin in BC cells. MAL2 silencing reduced the expression of ß-catenin and c-Myc, while the ß-catenin agonist SKL2001 partially rescued the downregulation of c-Myc and inhibition of migration and invasion caused by MAL2 knockdown in BC cells. CONCLUSION: These observations provided evidence that MAL2 acted as a potential tumor promoter by regulating EMT and ß-catenin/c-Myc axis, suggesting potential implications for anti-metastatic therapy for BC.

Relationships between Dark Triad and negative emotions during COVID-19 lockdown: The chain mediating roles of negative coping and state boredom.

Personality is distal vulnerability of negative emotions and vital to mental health. Dark Triad was significantly correlated with negative emotions, whereas the mechanisms beneath the relationships were less clear. Based on life history strategy theory (LHS) and cognitive vulnerability-transactional stress model, the study explored the relationships between Dark Triad and negative emotions and investigated the roles of negative coping style and state boredom in the relationships aforementioned during the strict period of COVID-19 lockdown in China. 464 participants (M age = 36.78 years; SD = 10.53) finished a package of measurements online including Depression Anxiety and Stress Scale (DASS-21), Short Dark Triad (SD3), Multidimensional State Boredom Scale (MSBS), and Simplified Coping Style Questionnaire (SCSQ). The results showed there were positive relationships between Dark Triad and depression, anxiety and stress. Moreover, the relationships between Dark Triad and negative emotions were sequentially mediated by negative coping style and state boredom. The present study offered fascinating perspectives in the relationships between Dark Triad and negative emotions, and revealed how Dark Triad affected depression, anxiety and stress during the initial phase of COVID-19 pandemic and strict lockdown among Chinese population. The present results may provide important implications for the prevention and intervention of depression, anxiety and stress during COVID-19 pandemic and lockdown. Specifically, the intervention strategies that focus on reducing Dark Triad, negative coping and boredom may help offset occurrence of negative emotional states.

Roles of genetic and microenvironmental factors in cancer epithelial-to-mesenchymal transition and therapeutic implication.

Epithelial-to-mesenchymal transition (EMT) is a process in which epithelial cells lose their cell-cell contacts resulting in the formation of mesenchymal cells with migratory properties. Increasing evidence indicate EMT plays a key role in the invasion, metastasis and therapeutic resistance of cancer and maintenance of the phenotype of cancer stem cells (CSCs), which makes the prognosis of patients worse. The progression of cancer from epithelial tissue towards a malignant phenotype is driven by multiple factors that remodel the tissue architecture. This review summarizes and analyzes current studies of genetic and microenvironmental factors in inducing and maintaining cancer EMT and therapeutic implications. This will enable a better understanding of the contribution of EMT-associated factors to cancer progression and highlights that genetic factors and tumor microenvironment responsible for EMT could be used as attractive targets for therapeutic intervention.

Morusin inhibits glioblastoma stem cell growth in vitro and in vivo through stemness attenuation, adipocyte transdifferentiation, and apoptosis induction.

Glioblastoma multiforme (GBM) cancer stem cells (GSCs) are responsible for the progression and recurrence of GBM after conventional therapy. Morusin possesses anti-cancer activity in vitro. The purpose of this study is to confirm the growth inhibition effect of morusin on human GSCs growth in vitro and in vivo and to explore the possible mechanism of its activity. Human GSCs were enriched under nonadhesive culture system, and characterized through neurosphere formation, toluidine blue staining, immunofluorescence staining, Western blotting analysis of stemness markers of CD133, nestin, Sox2 and Oct4, and tumorigenecity in vivo; the growth inhibition effect of morusin on human GSCs in vitro and in vivo were tested by cell cytotoxicity, neurosphere formation inhibition, adipogenic differentiation, apoptosis induction, and tumor growth inhibition in vivo assays. The potential molecular mechanisms underlying the growth inhibition effect of morusin on GSCs in vitro and in vivo were investigated with Western blotting evaluation of stemness, adipogenic, and apoptotic proteins in morusin treated GSCs and tumor tissues. GSCs enriched under nonadhesive culture system possess stemness characterstics; Morusin inhibited GSCs growth in vitro and in vivo, it reduced stemness of GSCs, induced them adipocyte-like transdifferention and apoptosis. Morusin has the potential to inhibit human GSCs growth in vitro and in vivo through stemness attenuation, adipocyte transdifferentiation, and apoptosis induction.

Lithocarpus polystachyus REHD leaf aqueous extract inhibits human breast cancer growth in vitro and in vivo.

Lithocarpus polystachyus leaves have been used as tea beverage and folk medicine for healthy care in the Southwest of China. The purpose of this study is to investigate the anticancer activity of Lithocarpus polystachyus Rehd leaf aqueous extract (LPAE) and to explore the possible mechanism of its activity. Growth inhibition effects of LPAE breast cancer were tested in vitro and in vivo. The possible mechanism of its activity was analyzed with cell biological and molecular biological assays. After LPAE treatment, the proliferation and colony formation of cancer cells decreased; apoptotic cells increased; DNA fragmentations were evident; mRNA and protein expressions of PPARγ, Bax, and caspase-3 genes increased and expressions of cyclin D1 and Bcl-2 genes decreased; in vivo experiment, LPAE inhibited human beast cancer growth. The findings in this experimental study suggested that LPAE has potential cytotoxic and apoptotic effects on human breast cancer cells in vitro and inhibits the cancer growth in vivo, and its mechanism of activity might be associated with apoptosis induction of cancer cells through upregulation of the mRNA and protein expressions of PPARγ, Bax, and capase-3 genes and downregulation of the expressions of cyclin D1 and Bcl-2 genes.

Tanshinone IIA inhibits breast cancer stem cells growth in vitro and in vivo through attenuation of IL-6/STAT3/NF-kB signaling pathways.

Cancer stem cells (CSCs) are maintained by inflammatory cytokines and signaling pathways. Tanshinone IIA (Tan-IIA) possesses anti-cancer and anti-inflammatory activities. The purpose of this study is to confirm the growth inhibition effect of Tan-IIA on human breast CSCs growth in vitro and in vivo and to explore the possible mechanism of its activity. Human breast CSCs were enriched and expanded under serum-free mammosphere culture condition, and identified through mammosphere formation, toluidine blue staining, immunofluorescence staining, and flow cytometry analysis of stemness markers of CD44/CD24 and ALDH, and tumorigenecity in vivo; the growth inhibition effect of Tan-IIA on human breast CSCs in vitro were tested by cell proliferation and mammosphere formation assays; inflammatory signaling pathway related protein expression in response to Tan-IIA, IL-6, STAT3, phospho-STAT3 (Tyr705), NF-κBp65 in cytoplasm and nucleus and cyclin D1 were evaluated with Western blotting; the growth inhibition effect of Tan-IIA on human breast CSCs growth were tested in vivo. A useful model of human breast CSCs for researching and developing the agents targeting CSCs was established. After Tan-IIA treatment, cell proliferation and mammosphere formation of CSCs were decreased significantly; the expression levels of IL-6, STAT3, phospho-STAT3 (Tyr705), NF-κBp65 in nucleus and cyclin D1 proteins were decreased significantly; the tumor growth and mean tumor weight were reduced significantly. Tan-IIA has the potential to target and kill CSCs, and can inhibit human breast CSCs growth both in vitro and in vivo through attenuation of IL-6/STAT3/NF-kB signaling pathways.

Morusin inhibits human cervical cancer stem cell growth and migration through attenuation of NF-κB activity and apoptosis induction.

Cancer stem cells (CSCs) are believed to be responsible for tumor metastasis, recurrence, and high mortality of cancer patients due to their high tumorigenicity resistance to chemo-radiotherapy. Morusin possesses anti-cancer activity through attenuation of NF-κB activity, which is up-regulated in cancer stem cells. The purpose of this study is to confirm the growth and migration inhibition effect of morusin on human cervical CSCs, and to clarify its partial mechanism of activity. Human cervical CSCs were enriched using non-adhesive culture system. Their stemness characteristics were identified with tumor sphere formation, self-renewal, toluidine blue staining, migration assays, RT-PCR analysis, and immunofluorescence staining of putative stem cell markers, Oct4, SOX2, and ALDH1; the epithelial-to-mesenchymal (EMT) transition markers and relevant transcription factors were evaluated with Western blotting. The growth and migration inhibition effects of morusin on human cervical CSCs were tested by cell proliferation, tumor sphere formation, and transwell assay; apoptotic death of human cervical CSCs in response to morusin was measured with DAPI staining, apoptotic DNA fragmentation; NF-κBp65, Bcl-2, Bax, and caspase-3 protein expressions were detected through Western blotting. Under this non-adhesive culture system, typical tumor spheres appeared within 5-7 days, the tumor sphere formation, self-renewal, and cell migration, expressions of putative stem cell markers, EMT markers, and relevant transcription factors of the tumor sphere cells were increased significantly. After morusin treatment, the proliferation, tumor sphere formation, and migration of human cervical CSCs were decreased significantly, DAPI-stained apoptotic cells increased, apoptotic DNA fragmentations formed evidently; the expression levels of NF-κBp65 and Bcl-2 decreased significantly, Bax, and caspase-3 increased significantly in a dose-dependent manner. Using the non-adhesive culture system, human cervical CSCs were enriched and expanded. Morusin has the potential to target and kill CSCs, and can inhibit human cervical growth and migration through NF-κB attenuation mediated apoptosis induction.

Hypoxia and hypoxia-inducible factors in glioblastoma multiforme progression and therapeutic implications.

Glioblastoma multiforme (GBM) is the most malignant and aggressive primary brain tumor in humans, with a uniformly poor prognosis. Hypoxia is a predominant feature in GBM and its microenvironment; it is associated with the tumor growth, progression and resistance to conventional therapy of cancers. Hypoxia-inducible factors (HIFs) are the master regulators of the transcriptional response to hypoxia in tumor cells and their microenvironment. Numerous studies indicated that hypoxia and HIFs played pivotal roles in the initiation, progression, therapy resistance and recurrence of GBM and maintained the phenotype of glioma stem cells (GSCs), which makes the prognosis of GBM patients worse. This review summarized the current research advance of hypoxia and HIFs in GBM progression and therapeutic implications, which will provide a better understanding of the contribution of hypoxia and HIFs to GBM initiation and progression and highlight that HIFs might be taken as the attractive molecular target approaches for GBM therapeutics.

Bisbenzylisoquinoline alkaloid fangchinoline derivative HY-2 inhibits breast cancer cells by suppressing BLM DNA helicase.

The high expression of BLM (Bloom syndrome) DNA helicase in tumors involves its strong association with cell expansion. Bisbenzylisoquinoline alkaloids own an antitumor property and have developed as candidates for anticancer drugs. This paper aimed to study the antitumor effect of fangchinoline derivative HY-2 by targeting BLM642-1290 DNA helicase, and then explore its inhibitory mechanism on proliferation of MDA-MB-435 breast cancer cells. We confirmed that the mRNA and protein levels of BLM DNA helicase in breast cancer were higher than those in normal tissues. HY-2 could inhibit the DNA binding, ATPase and DNA unwinding of BLM642-1290 DNA helicase with enzymatic assay. HY-2 could also inhibit the DNA unwinding of DNA helicase in cells. In addition, HY-2 showed an inhibiting the MDA-MB-435, MDA-MB-231, MDA-MB-436 breast cancer cells expansion. The mRNA and protein levels of BLM DNA helicase in MDA-MB-435 cells increased after HY-2 treatment, which might contribute to HY-2 inhibiting the DNA binding, ATPase and DNA unwinding of BLM DNA helicase. The mechanism of HY-2 inhibition on BLM DNA helicase was further confirmed with the effect of HY-2 on the ultraviolet spectrogram of BLM642-1290 DNA helicase and Molecular dynamics simulation of the interacting between HY-2 and BLM640-1291 DNA helicase. Our study provided some valuable clues for the exploration of HY-2 in the living body and developing it as an anticancer drug.

Sex Differences in Traditional School Bullying Perpetration and Victimization among Adolescents: A Chain-Mediating Effect.

The study explored sex differences in traditional school bullying perpetration and victimization among Chinese adolescents and the effects of Machiavellianism and school climate. Data were collected from 727 adolescents (M = 16.8 years, SD = 0.9) who completed the Olweus Bully/Victim Questionnaire, Kiddie Machiavellian Scale, and School Climate Perception Questionnaire. Results showed: (1) boys were more likely to bully others and be bullied; (2) both Machiavellianism and school climate partially mediated sex differences in school bullying perpetration and victimization; (3) the chain-mediating effect of Machiavellianism and school climate on sex differences in bullying perpetration and victimization was significant. These results provide insight into the sex differences in Chinese traditional school bullying perpetration and victimization. The implications are interpreted and discussed.

Gene admixture in ethnic populations in upper part of Silk Road revealed by mtDNA polymorphism.

To evaluate the gene admixture on the current genetic landscape in Gansu Corridor (GC) in China, the upper part of the ancient Silk Road which connects the Eastern and Central Asia, we examined mitochondrial DNA (mtDNA) polymorphisms of five ethnic populations in this study. Using PCR-RFLP and sequencing, we analyzed mtDNA haplotypes in 242 unrelated samples in three ethnic populations from the GC region and two ethnic populations from the adjacent Xinjiang Uygur Autonomous Region of China. We analyzed the data in comparison with the previously reported data from Eastern, Central and Western Asia and Europe. We found that both European-specific haplogroups and Eastern Asian-specific haplogroups exist in the Gansu Corridor populations, while a modest matrilineal gene flow from Europeans to this region was revealed. The Gansu Corridor populations are genetically located between Eastern Asians and Central Asians, both of who contributed significantly to the maternal lineages of the GC populations. This study made the landscape of the gene flow and admixture along the Silk Road from Europe, through Central Asia, to the upper part of the Silk Road more complete.

Enrichment and characterization of cancer stem­like cells from a cervical cancer cell line.

Cancer stem cells (CSCs) are proposed to be responsible for tumor recurrence, metastasis and the high mortality rate of cancer patients. Isolation and identification of CSCs is crucial for basic and preclinical studies. However, as there are currently no universal markers for the isolation and identification of CSCs in any type of cancer, the method for isolating CSCs from primary cancer tissues or cell lines is costly and ineffective. In order to establish a reliable model of cervical cancer stem cells for basic and preclinical studies, the present study was designed to enrich cervical cancer CSCs using a nonadhesive culture system and to characterize their partial stemness phenotypes. Human cervical cancer cells (HeLa) were cultured using a nonadhesive culture system to generate tumor spheres. Their stemness characteristics were investigated through colony formation, tumor sphere formation, self-renewal, toluidine blue staining, chemoresistance, invasion assays, reverse transcription-polymerase chain reaction, immunofluorescence staining of putative stem cell markers, including octamer-binding transcription factor 4, SRY-box 2 and aldehyde dehydrogenase 1 family, member A1, and adipogenic differentiation induction. Typical tumor spheres were formed within 5-7 days under this nonadhesive culture system. Compared with the adherent parental HeLa cells, the colony formation capacity, self-renewal potential, light cell population, cell invasion, chemoresistance and expression of putative stem cell markers of the tumor sphere cells increased significantly, and a subpopulation of tumor sphere cells were induced into adipogenic differentiation. Using the nonadhesive culture system, a reliable model of cervical cancer stem cells was established, which is inexpensive, effective and simple compared with the ultra-low attachment serum free culture method. The stemness characteristics of the tumor sphere HeLa cells mirrored the CSC phenotypes. This CSC model may be useful for basic and preclinical studies of cervical cancer and other types of cancer.

Tanshinone IIA inhibits the growth, attenuates the stemness and induces the apoptosis of human glioma stem cells.

Glioma stem cells (GSCs) are believed to contribute to glioblastoma multiforme (GBM) propagation and treatment resistance. Tanshinone IIA possesses anticancer and anti-inflammatory activities. This study aimed to determine the inhibitory effect of tanshinone IIA on human GSCs in vitro and in vivo and to explore the underlying mechanisms. In the present study, human GBM neurospheres (GBMS) were isolated from adherent GBM cells in serum-free medium, and the cells from the GBMS displayed characteristics of GSCs. Results from the MTT, neurosphere formation and in vivo inhibition assays revealed that tanshinone IIA had a significant inhibitory effect on human GSCs in vitro and in vivo. Furthermore, tanshinone IIA increased the expression of differentiation and neural lineage markers including GFAP and ß-tubulin, decreased expression of GSC markers including CD133 and nestin, and induced GSC apoptosis in vitro and in vivo in a dose­dependent manner. Inflammatory cytokines and signaling pathways are believed to play key roles in maintaining the stem-like properties in human glioma cells. In the present study, inflammatory cytokine interleukin 6 (IL6) and its downstream activated signal transducer and activator of transcription 3 [phospho-STAT3(tyrosine705) and phospho-STAT3(serine727)] were downregulated after tanshinone IIA treatment in vitro and in vivo. This result indicated that disturbance of the IL6/STAT3 signaling axis by tanshinone IIA is closely related to the growth inhibition of GSCs. Taken together, our results indicate that tanshinone IIA has the potential to target and kill GSCs through suppression of proliferation, attenuation of stemness and induction of apoptosis. Its mechanism of activity may be associated with attenuation of the IL6/STAT3 signaling pathway.