Thymosin alpha 1 suppresses proliferation and induces apoptosis in breast cancer cells through PTEN-mediated inhibition of PI3K/Akt/mTOR signaling pathway. Apoptosis. 2015;20:1109-1121. [PMID: 26002438 DOI: 10.1007/s10495-015-1138-9]

Evaluating the in vitro and in vivo effects of carvacrol zinc oxide quantum dots in breast cancer

The study investigates the molecular interactions and biological effects of carvacrol zinc oxide quantum dots (CVC-ZnO QDs) on breast cancer in vitro MCF-7 cell lines and in vivo mammary cancer models. Molecular docking using AutoDock Vina revealed binding energies of CVC with key proteins in the PI3K/AKT/mTOR pathway, including PI3K, AKT, PTEN, and mTOR. The results showed significant interaction with specific amino acids, indicating a strong binding affinity. In vitro studies demonstrated a dose-dependent cytotoxic effect of CVC-ZnO QDs on MCF-7 cells, with an IC50 of 20.02 µg/mL, while enhancing intracellular reactive oxygen species (ROS) and decreasing mitochondrial membrane potential (MMP), indicative of apoptosis induction. Antioxidant activity, lipid peroxidation, and nuclear morphological changes were assessed, revealing decreased antioxidant status and increased lipid peroxidation in treated cells. In vivo, CVC-ZnO QDs modulated the PI3K/AKT/mTOR signaling in DMBA-induced mammary cancer in rats, decreasing p-PI3K, p-AKT, and p-mTOR expression while upregulating PTEN. Immunohistochemistry, qRT-PCR, and Western blot analyses confirmed these molecular alterations. The study concludes that CVC-ZnO QDs exert cytotoxic and pro-apoptotic effects on breast cancer cells by modulating the PI3K/Akt/mTOR pathway and promoting oxidative stress, presenting a potential therapeutic strategy for breast cancer management.

Molecular mechanisms of mTOR-mediated cisplatin response in tumor cells

Cisplatin (CDDP) is one of the main chemotherapeutic drugs that is widely used in many cancers. However, CDDP resistance is a frequent therapeutic challenge that reduces prognosis in cancer patients. Since, CDDP has noticeable side effects in normal tissues and organs, it is necessary to assess the molecular mechanisms associated with CDDP resistance to improve the therapeutic methods in cancer patients. Drug efflux, detoxifying systems, DNA repair mechanisms, and drug-induced apoptosis are involved in multidrug resistance in CDDP-resistant tumor cells. Mammalian target of rapamycin (mTOR), as a serine/threonine kinase has a pivotal role in various cellular mechanisms such as autophagy, metabolism, drug efflux, and cell proliferation. Although, mTOR is mainly activated by PI3K/AKT pathway, it can also be regulated by many other signaling pathways. PI3K/Akt/mTOR axis functions as a key modulator of drug resistance and unfavorable prognosis in different cancers. Regarding, the pivotal role of mTOR in CDDP response, in the present review we discussed the molecular mechanisms that regulate mTOR mediated CDDP response in tumor cells.

Phenotypic drug discovery: a case for thymosin alpha-1

Phenotypic drug discovery (PDD) involves screening compounds for their effects on cells, tissues, or whole organisms without necessarily understanding the underlying molecular targets. PDD differs from target-based strategies as it does not require knowledge of a specific drug target or its role in the disease. This approach can lead to the discovery of drugs with unexpected therapeutic effects or applications and allows for the identification of drugs based on their functional effects, rather than through a predefined target-based approach. Ultimately, disease definitions are mostly symptom-based rather than mechanism-based, and the therapeutics should be likewise. In recent years, there has been a renewed interest in PDD due to its potential to address the complexity of human diseases, including the holistic picture of multiple metabolites engaging with multiple targets constituting the central hub of the metabolic host-microbe interactions. Although PDD presents challenges such as hit validation and target deconvolution, significant achievements have been reached in the era of big data. This article explores the experiences of researchers testing the effect of a thymic peptide hormone, thymosin alpha-1, in preclinical and clinical settings and discuss how its therapeutic utility in the precision medicine era can be accommodated within the PDD framework.

αO-Conotoxin GeXIVA[1,2] Suppresses In Vivo Tumor Growth of Triple-Negative Breast Cancer by Inhibiting AKT-mTOR, STAT3 and NF-κB Signaling Mediated Proliferation and Inducing Apoptosis

Breast cancer is one of the leading causes of cancer mortality worldwide, and triple-negative breast cancer (TNBC) is the most problematic subtype. There is an urgent need to develop novel drug candidates for TNBC. Marine toxins are a valuable source for drug discovery. We previously identified αO-conotoxin GeXIVA[1,2] from Conus generalis, which is a selective antagonist of α9 nicotinic acetylcholine receptors (nAChRs). Recent studies indicated that α9 nAChR expression is positively correlated with breast cancer development; thus, α9 nAChR could serve as a therapeutic target for breast cancer. In this study, we aimed to investigate the in vivo antitumor effects of GeXIVA[1,2] on TNBC and to elucidate its underlying anticancer mechanism. Our data showed that GeXIVA[1,2] effectively suppressed 4T1 tumor growth in vivo at a very low dose of 0.1 nmol per mouse. Our results uncovered that the antitumor mechanism of GeXIVA[1,2] simultaneously induced apoptosis and blocked proliferation. Further investigations revealed that GeXIVA[1,2]-induced Caspase-3-dependent apoptosis was achieved through regulating Bax/Bcl-2 balance, and GeXIVA[1,2]-inhibited proliferation was mediated by the downregulation of the AKT-mTOR, STAT3 and NF-κB signaling pathways. Our study provides valuable arguments to demonstrate the potential of GeXIVA[1,2] as a novel marine-derived anticancer drug candidate for the treatment of TNBC.

Environmental pollutants and phosphoinositide signaling in autoimmunity

Environmental pollution stands as one of the most critical challenges affecting human health, with an estimated mortality rate linked to pollution-induced non-communicable diseases projected to range from 20% to 25%. These pollutants not only disrupt immune responses but can also trigger immunotoxicity. Phosphoinositide signaling, a pivotal regulator of immune responses, plays a central role in the development of autoimmune diseases and exhibits high sensitivity to environmental stressors. Among these stressors, environmental pollutants have become increasingly prevalent in our society, contributing to the initiation and exacerbation of autoimmune conditions. In this review, we summarize the intricate interplay between phosphoinositide signaling and autoimmune diseases within the context of environmental pollutants and contaminants. We provide an up-to-date overview of stress-induced phosphoinositide signaling, discuss 14 selected examples categorized into three groups of environmental pollutants and their connections to immune diseases, and shed light on the associated phosphoinositide signaling pathways. Through these discussions, this review advances our understanding of how phosphoinositide signaling influences the coordinated immune response to environmental stressors at a biological level. Furthermore, it offers valuable insights into potential research directions and therapeutic targets aimed at mitigating the impact of environmental pollutants on the pathogenesis of autoimmune diseases. SYNOPSIS: Phosphoinositide signaling at the intersection of environmental pollutants and autoimmunity provides novel insights for managing autoimmune diseases aggravated by pollutants.

MicroRNAs as the critical regulators of autophagy-mediated cisplatin response in tumor cells

Chemotherapy is one of the most common therapeutic methods in advanced and metastatic tumors. Cisplatin (CDDP) is considered as one of the main first-line chemotherapy drugs in solid tumors. However, there is a high rate of CDDP resistance in cancer patients. Multi-drug resistance (MDR) as one of the main therapeutic challenges in cancer patients is associated with various cellular processes such as drug efflux, DNA repair, and autophagy. Autophagy is a cellular mechanism that protects the tumor cells toward the chemotherapeutic drugs. Therefore, autophagy regulatory factors can increase or decrease the chemotherapy response in tumor cells. MicroRNAs (miRNAs) have a pivotal role in regulation of autophagy in normal and tumor cells. Therefore, in the present review, we discussed the role of miRNAs in CDDP response through the regulation of autophagy. It has been reported that miRNAs mainly increased the CDDP sensitivity in tumor cells by inhibition of autophagy. PI3K/AKT signaling pathway and autophagy-related genes (ATGs) were the main targets of miRNAs in the regulation of autophagy-mediated CDDP response in tumor cells. This review can be an effective step to introduce the miRNAs as efficient therapeutic options to increase autophagy-mediated CDDP sensitivity in tumor cells.

Gene mutations in the PI3K/Akt signaling pathway were related to immune thrombocytopenia pathogenesis

BACKGROUND

Immune thrombocytopenic (ITP) is an autoimmune bleeding disease with genetic susceptibility. Twenty newly diagnosed active primary ITP patients who had not been treated with glucocorticosteroids, immune globulin or immunosuppressants prior to sampling were enrolled in this study. Bone marrow blood mononuclear cells were used for whole exome sequencing to further elucidation the variant genes of ITP.

METHODS

High-molecular-weight genomic DNA was extracted from freshly frozen bone marrow blood mononuclear cells from 20 active ITP patients. Next, the samples were subjected to molecular genetic analysis by whole-exome sequencing, and the results were confirmed by Sanger sequencing. The signaling pathways and cellular processes associated with the mutated genes were identified with gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses.

RESULTS

The results showed that there were 3998 missense mutations involving 2269 genes in more than 10 individuals. Unique genetic variants including phosphatase and tensin homolog, insulin receptor, and coagulation factor C homology were the most associated with the pathogenesis of ITP. Functional analysis revealed these mutation genes mainly affect Phosphatidylinositol 3 kinase/serine/threonine kinase B signaling pathways (signal transduction) and platelet activation (immune system).

CONCLUSION

Our finding further demonstrates the functional connections between these variant genes and ITP. Although the substantial mechanism and the impact of genetic variation are required further investigation, the application of next generation sequencing in ITP in this paper is a valuable method to reveal the genetic susceptibility.

RBM10 regulates alternative splicing of lncRNA Neat1 to inhibit the invasion and metastasis of NSCLC

Background

Non-small cell lung cancer (NSCLC) accounts for more than 85% of the total cases with lung cancer. NSCLC is characterized by easy metastasis, which often spreads to bones, brains and livers. RNA-binding motif protein 10 (RBM10) is an alternative splicing (AS) regulator frequently mutated in NSCLC. We found that there were multiple peak binding sites between RBM10 and long non-coding RNA nuclear enriched abundant transcript 1 (LncRNA Neat1) by crosslinking-immunprecipitation and high-throughput sequencing (Clip-Seq). LncRNA Neat1 plays an indispensable role in promoting cancer in a variety of tumors and produces two splicing variants: Neat1_1 and Neat1_2. This study aims to explore the mechanism of RBM10 and LncRNA Neat1 in invasion and metastasis of NSCLC.

Methods

Through histological and cytological experiments, we assessed the expression level of RBM10 protein expression. The interaction between RBM10 and Neat1 was evaluated via Clip-Seq and RNA immunoprecipitation assay. The effect of RBM10 on Neat1 and its splicing variants was identified by RT-qPCR. The effect of RBM10 and Neat1 on invasive and metastasis phenotypes of NSCLC was analyzed using transwell invasion assay and scratch test. Additionally, downstream signaling pathway of RBM10 were identified by immunofluorescence and western blot.

Results

RBM10 exhibited low levels of expression in NSCLC tissues and cells. RBM10 inhibited the invasion and metastasis of NSCLC and recruited Neat1 and Neat1_2. Overexpression of RBM10 simultaneously inhibited Neat1 and Neat1_2, and promoted the expression of Neat1_1. On the other hand, silencing RBM10 promoted Neat1 and Neat1_2, and inhibited the expression of Neat1_1. From this, we concluded that RBM10 regulated AS of Neat1, and the tumor-promoting effect of Neat1 was mainly attributed to Neat1_2. RBM10 had a negative correlation with Neat1_2. In addition, RBM10 upregulated the expression of PTEN and downregulated the phosphorylation of PI3K/AKT/mTOR through Neat1_2, which ultimately inhibited the invasion and metastasis of NSCLC.

Conclusion

The RBM10 regulated AS of Neat1 to cause the imbalance of Neat1_1 and Neat1_2, and RBM10 suppressed the activation of the PTEN/PI3K/AKT/mTOR signal by downregulating Neat1_2, finally affected the invasion and metastasis of NSCLC.

Cell Senescence and Central Regulators of Immune Response

Pathways regulating cell senescence and cell cycle underlie many processes associated with ageing and age-related pathologies, and they also mediate cellular responses to exposure to stressors. Meanwhile, there are central mechanisms of the regulation of stress responses that induce/enhance or weaken the response of the whole organism, such as hormones of the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic and parasympathetic systems, thymic hormones, and the pineal hormone melatonin. Although there are many analyses considering relationships between the HPA axis and organism ageing, we found no systematic analyses of relationships between the neuroendocrine regulators of stress and inflammation and intracellular mechanisms controlling cell cycle, senescence, and apoptosis. Here, we provide a review of the effects of neuroendocrine regulators on these mechanisms. Our analysis allowed us to postulate a multilevel system of central regulators involving neurotransmitters, glucocorticoids, melatonin, and the thymic hormones. This system finely regulates the cell cycle and metabolic/catabolic processes depending on the level of systemic stress, stage of stress response, and energy capabilities of the body, shifting the balance between cell cycle progression, cell cycle stopping, senescence, and apoptosis. These processes and levels of regulation should be considered when studying the mechanisms of ageing and the proliferation on the level of the whole organism.

Impact of thymosin α1 as an immunomodulatory therapy on long-term survival of non-small cell lung cancer patients after R0 resection: a propensity score-matched analysis

BACKGROUND

There is limited information about thymosin α1 (Tα1) as adjuvant immunomodulatory therapy, either used alone or combined with other treatments, in patients with non-small cell lung cancer (NSCLC). This study aimed to evaluate the effect of adjuvant Tα1 treatment on long-term survival in margin-free (R0)-resected stage IA-IIIA NSCLC patients.

METHODS

A total of 5746 patients with pathologic stage IA-IIIA NSCLC who underwent R0 resection were included. The patients were divided into the Tα1 group and the control group according to whether they received Tα1 or not. A propensity score matching (PSM) analysis was performed to reduce bias, resulting in 1027 pairs of patients.

RESULTS

After PSM, the baseline clinicopathological characteristics were similar between the two groups. The 5-year disease-free survival (DFS) and overall survival (OS) rates were significantly higher in the Tα1 group compared with the control group. The multivariable analysis showed that Tα1 treatment was independently associated with an improved prognosis. A longer duration of Tα1 treatment was associated with improved OS and DFS. The subgroup analyses showed that Tα1 therapy could improve the DFS and/or OS in all subgroups of age, sex, Charlson Comorbidity Index (CCI), smoking status, and pathological tumor-node-metastasis (TNM) stage, especially for patients with non-squamous cell NSCLC and without targeted therapy.

CONCLUSION

Tα1 as adjuvant immunomodulatory therapy can significantly improve DFS and OS in patients with NSCLC after R0 resection, except for patients with squamous cell carcinoma and those receiving targeted therapy. The duration of Tα1 treatment is recommended to be >24 months.

Combination of Gemcitabine and Thymosin alpha 1 exhibit a better anti-tumor effect on nasal natural killer/T-cell lymphoma

BACKGROUND

Nasal natural killer/T-cell lymphoma (NNKTL) is an aggressive and poor prognostic malignant tumor along with high-level infection of Epstein-Barr virus (EBV). Gemcitabine (Gem) and Thymosin alpha 1 (Tα1) exert an anti-tumor effect in various cancers. However, the effect of the combination of Gem and Tα1 in NNKTL remains unknown.

METHODS

SNK6 cells were treated with Gem, Tα1 and Gem plus Tα1 for 48 h. The expression levels of EBV and inflammatory factors were measured by qRT-PCR assay. The effect of Gem and Tα1 on cell viability, proliferation, apoptosis, autophagy was detected by CCK-8, colony formation, flow cytometry, autophagic flux measurement, respectively. Western blot was used to evaluate the expression of proteins related to epithelial-mesenchymal transition (EMT), apoptosis and autophagy. In vivo xenograft models were used to further verify the roles of Gem and Tα1. Tumors were removed for weight measurement, H&E and IHC staining.

RESULTS

We identified that the half maximal inhibitory concentration (IC50) of Gem and Tα1 was 116.5 μmol/ml and 1.334 μmol/ml. Alone or combined administration of Gem and Tα1 dramatically attenuated the EBV viral load and promoted inflammatory factors expression in SNK6 cells, among which the combination of Gem and Tα1 treatment showed the most significant effect. Besides, combination treatment with Gem and Tα1 markedly inhibited cell growth and EMT progress, and enhanced apoptosis and autophagy. Similarly, Gem combined with Tα1 suppressed tumor growth, promoted apoptosis and autophagy in vivo. Additionally, combination treatment with Gem and Tα1 inhibited PI3K/AKT/mTOR pathway.

CONCLUSION

In summary, combination administration of Gem and Tα1 suppressed the progression of NNKTL in vivo and in vitro. Our study provided an effective therapeutic strategy potentially for the clinical treatment of NNKTL.

Thymosin alpha 1: A comprehensive review of the literature

Thymosin alpha 1 is a peptide naturally occurring in the thymus that has long been recognized for modifying, enhancing, and restoring immune function. Thymosin alpha 1 has been utilized in the treatment of immunocompromised states and malignancies, as an enhancer of vaccine response, and as a means of curbing morbidity and mortality in sepsis and numerous infections. Studies have postulated that thymosin alpha 1 could help improve the outcome in severely ill corona virus disease 2019 patients by repairing damage caused by overactivation of lymphocytic immunity and how thymosin alpha 1 could prevent the excessive activation of T cells. In this review, we discuss key literature on the background knowledge and current clinical uses of thymosin alpha 1. Considering the known biochemical properties including antibacterial and antiviral properties, time-honored applications, and the new promising findings regarding the use of thymosin, we believe that thymosin alpha 1 deserves further investigation into its antiviral properties and possible repurposing as a treatment against severe acute respiratory syndrome coronavirus-2.

A novel 4-aminoquinazoline derivative, DHW-208, suppresses the growth of human breast cancer cells by targeting the PI3K/AKT/mTOR pathway

Breast cancer is one of the most frequent cancers among women worldwide. However, there is still no effective therapeutic strategy for advanced breast cancer that has metastasized. Aberrant activation of the PI3K/AKT/mTOR pathway is an essential step for the growth of human breast cancers. In our previous study, we designed and synthesized DHW-208 (2,4-difluoro-N-(5-(4-((1-(2-hydroxyethyl)-1H-pyrazol-4-yl)amino)quinazolin-6-yl)-2-methoxypyridin-3-yl)benzenesulfonamide) as a novel pan-PI3K inhibitor. This study aimed to assess the therapeutic efficacy of DHW-208 in breast cancer and investigate its underlying mechanism. We found that DHW-208 inhibited the growth, proliferation, migration, and invasion of breast cancer cells. Moreover, DHW-208 induced breast cancer cell apoptosis via the mitochondrial pathway and induced G0/G1 cell-cycle arrest. In vitro results show that DHW-208 is a dual inhibitor of PI3K and mTOR, and suppress the growth of human breast cancer cells by targeting the PI3K/AKT/mTOR pathway. Consistent with the in vitro results, in vivo studies demonstrated that DHW-208 elicits an antitumor effect by inhibiting the PI3K/AKT/mTOR-signaling pathway with a high degree of safety in breast cancer. Above all, we report for the first time that DHW-208 suppressed the growth of human breast cancer cells by inhibiting the PI3K/AKT/mTOR-signaling pathway both in vivo and in vitro. Our study may provide evidence for the use of DHW-208 as an effective, novel therapeutic candidate for the treatment of human breast cancers in clinical trials.

Thymosin alpha-1; a natural peptide inhibits cellular proliferation, cell migration, the level of reactive oxygen species and promotes the activity of antioxidant enzymes in human lung epithelial adenocarcinoma cell line (A549)

This research was conducted to investigate the biochemical effects of thymosin alpha-1 using human lung cancer cells (A549). The A549 cells were treated with different concentrations of Thα1 for 24 h and the growth, inhibition of cells was determined. Thα1 revealed anti-proliferative effect at 24 and 48 μg/ml after 24 h. Furthermore, it indicated antioxidant properties by significantly enhancing the activity of catalase (12 μg/ml), superoxide dismutase (6 and 12 μg/ml), and glutathione peroxidase (3, 6 and 12 μg/ml) and reducing the production of cellular ROS. Our results showed that Thα1 inhibits the migration of A549 cells in a concentration-dependent manner after 24 and 48 h. Moreover, the effect of Thα1 on apoptosis was investigated by Hoechst 33342 staining and cell cycle analysis. Results demonstrated no significant effect on the induction of apoptosis in A549 cells. In conclusion, our results showed the antioxidant properties of Thα1 on A549 cancer cells.

Clinical efficacy and safety of synthetic thymic peptides with chemotherapy for non-small cell lung cancer in China: A systematic review and meta-analysis of 27 randomized controlled trials following the PRISMA guidelines

BACKGROUND

Synthetic thymic peptides (sTPs) are used with chemotherapy to treat non-small cell lung cancer (NSCLC). In this study, we have performed a systematic review and meta-analysis of published trials to confirm the clinical efficacy and safety of sTPs, and determine the optimal types, usages, and sTP/chemotherapy combinations to produce the desired responses.

MATERIALS AND METHODS

We collected all studies regarding combined sTP therapy and chemotherapy for NSCLC from the Chinese and English databases (up to October 2018). Bias risk was evaluated for each. Data for meta-analysis was extracted using a pre-designed form. Evidence quality was rated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

We included 27 randomized controlled trials containing 1925 patients, most with unclear bias risk. Combining sTPs with chemotherapy significantly increased the objective response rate [1.28, (1.13 to 1.45)], disease control rate [1.10, (1.01 to 1.18)], quality of life (QOL) [2.05, (1.62, 2.60)], and 1-year overall survival rate [1.43, (1.15 to 1.78)], with decreased risks of neutropenia, thrombocytopenia, and gastrointestinal reactions. Optimal conditions included treatment in combination with gemcitabine or navelbine and cisplatin, twice a week, with one 3-week cycle. In these conditions, thymosin α1 improved both antitumor immunity and tumor response. Most results had good robustness, and their quality ranged from moderate to very low.

CONCLUSIONS

The results suggest that treatment with sTPs, especially thymosin α1, and concomitant chemotherapy is beneficial to the patient, and provide evidence for optimal treatment regimens that may increase patient QOL and survival.

Bioactive Thymosin Alpha-1 Does Not Influence F508del-CFTR Maturation and Activity

Deletion of phenylalanine 508 (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel is the most frequent mutation causing cystic fibrosis (CF). F508del-CFTR is misfolded and prematurely degraded. Recently thymosin a-1 (Tα-1) was proposed as a single molecule-based therapy for CF, improving both F508del-CFTR maturation and function by restoring defective autophagy. However, three independent laboratories failed to reproduce these results. Lack of reproducibility has been ascribed by the authors of the original paper to the use of DMSO and to improper handling. Here, we address these potential issues by demonstrating that Tα-1 changes induced by DMSO are fully reversible and that Tα-1 peptides prepared from different stock solutions have equivalent biological activity. Considering the negative results here reported, six independent laboratories failed to demonstrate F508del-CFTR correction by Tα-1. This study also calls into question the autophagy modulator cysteamine, since no rescue of mutant CFTR function was detected following treatment with cysteamine, while deleterious effects were observed when bronchial epithelia were exposed to cysteamine plus the antioxidant food supplement EGCG. Although these studies do not exclude the possibility of beneficial immunomodulatory effects of thymosin α-1, they do not support its utility as a corrector of F508del-CFTR.

SHCBP1 regulates apoptosis in lung cancer cells through phosphatase and tensin homolog

Src homologous and collagen (SHC) SH2-binding protein 1 (SHCBP1) is a member of the SHC family, and is overexpressed in numerous types of cancer. In addition, apoptosis serves an important role in the development of cancer. The purpose of this study was to examine the effect of SHCBP1 on apoptosis and its potential underlying mechanism in lung cancer cells. Apoptosis was detected by flow cytometry and caspase-3 activity analysis. The expression levels of SHCBP1 and phosphatase and tensin homolog (PTEN) were detected by western blot analysis and reverse transcription-quantitative polymerase chain reaction. Cell viability was determined by MTT assay. The results indicated that SHCBP1 was increased in lung cancer cell lines and lung cancer tissues compared with in normal lung cell lines and tissues. The apoptosis of lung cancer cells was significantly increased by SHCBP1 small interfering RNA (siRNA), as indicated by the increased number of apoptotic cells and enhanced caspase-3 activity. In addition, it was demonstrated that PTEN expression was modulated by SHCBP1 knockdown; silencing of SHCBP1 expression led to a significant increase in PTEN expression. Furthermore, inhibition of PTEN by siRNA reversed the increase in apoptosis induced by SHCBP1 siRNA. These results suggested that SHCBP1 may be upregulated in lung cancer and it may serve a key role in the apoptosis of lung cancer cells; this effect was associated with the expression of PTEN.

Thymosin α1 suppresses migration and invasion of PD-L1 high-expressing non-small-cell lung cancer cells via inhibition of STAT3-MMP2 signaling

Background

Thymosin α1 (Tα1) is one of the most commonly used immunomodulators for metastatic non-small-cell lung cancer (NSCLC) patients in many countries. Despite the identification of the direct suppression on cancer cell proliferation, little is known about its effect on metastasis and metastasis-related signaling such as matrix metalloproteinases (MMPs) and programmed cell death ligand 1 (PD-L1).

Materials and methods

NSCLC cells with distinguishing PD-L1 expression levels were treated with Tα1. siRNAs were used to knockdown PD-L1. Cell migration and invasion abilities were evaluated by wound-healing and transwell assays. The xenograft model by BALB/c nude mice was constructed to test the inhibitory effect of Tα1 on metastasis in vivo. The expression levels of metastasis-related signaling pathways and key molecules were assessed by Western blot (WB) and quantitative reverse transcriptase PCR (qRT-PCR).

Results

Tα1 significantly suppressed cell migration and invasion in PD-L1 high-expressing H1299, NL9980, and L9981 cells but not in PD-L1 low-expressing A549 or SPC-A-1 cells. This difference was demonstrated by mouse model in vivo as well. Knocking down of PD-L1 significantly impaired the inhibition of cell migration and invasion caused by Tα1 treating in PD-L1 high-expressing cells. Besides, Tα1 inhibited the activation and translocation of STAT3 and the expression of MMP2 in PD-L1 high-expressing NSCLC cells. Moreover, the treatment of STAT3 activator colivelin could partly reverse the Tα1-induced MMP2 suppression and the migration phenotype.

Conclusion

Tα1 significantly suppresses migration and invasion in PD-L1 high-expressing NSCLC cells compared with PD-L1 low-expressing NSCLC cells in vitro and in vivo, through the downregulation of STAT3–MMP2 signaling. These different responses to Tα1, together with the depiction of Tα1-induced signaling changes, suggest a potential benefit of Tα1 for PD-L1-positive NSCLC patients, enlightening the combination of Tα1 with target therapy or immune checkpoint inhibitors.

Thymosin Alpha1-Fc Modulates the Immune System and Down-regulates the Progression of Melanoma and Breast Cancer with a Prolonged Half-life

Thymosin alpha 1 (Tα1) is a biological response modifier that has been introduced into markets for treating several diseases. Given the short serum half-life of Tα1 and the rapid development of Fc fusion proteins, we used genetic engineering method to construct the recombinant plasmid to express Tα1-Fc (Fc domain of human IgG4) fusion protein. A single-factor experiment was performed with different inducers of varying concentrations for different times to get the optimal condition of induced expression. Pure proteins higher than 90.3% were obtained by using 5 mM lactose for 4 h with a final production about 160.4 mg/L. The in vivo serum half-life of Tα1-Fc is 25 h, almost 13 times longer than Tα1 in mice models. Also, the long-acting protein has a stronger activity in repairing immune injury through increasing number of lymphocytes. Tα1-Fc displayed a more effective antitumor activity in the 4T1 and B16F10 tumor xenograft models by upregulating CD86 expression, secreting IFN-γ and IL-2, and increasing the number of tumor-infiltrating CD4+ T and CD8+ T cells. Our study on the novel modified Tα1 with the Fc segment provides valuable information for the development of new immunotherapy in cancer.

Effect of a C-end rule modification on antitumor activity of thymosin α1

Thymosin α1 (Tα1), a hormone containing 28 amino acids, has been approved in several cancer therapies, but the lack of tumor-targeting hinders its full use in tumor treatment. We designed a new peptide by connecting Tα1 and RGDR, generating a product, Tα1-RGDR, where RGDR is located in the C-end with both tumor-homing and cell internalizing properties (C-end rule peptides, a consensus R/KXXR/K motif). This work aimed to study the antitumor and immunological activities of Tα1-RGDR, and its differences compared with the wild-type Tα1. The antitumor and immunological activities of Tα1-RGDR were measured using the B16F10 tumor and immunologic suppression models. Tα1-RGDR treatment led to significant inhibition of tumor growth at a dose at which Tα1 showed a slight effect in the B16F10 tumor growth model. In the immunologic suppression model, Tα1-RGDR shared almost equivalent immunomodulatory effect with Tα1. These results demonstrated the better therapeutic effects after treatment with Tα1-RGDR compared with Tα1. Moreover, both Tα1-RGDR and Tα1 shared a helical conformation in the presence of trifluoroethanol based on CD spectroscopy. Our dock information of Tα1-RGDR when combined with integrin αvβ3 or neuropilin-1 further confirmed previous experimental results. All these findings suggest that Tα1-RGDR might be a useful therapy for tumors by overcoming its wild type limitation of tumor homing.

miRNA-23a has effects to improve lung injury induced by sepsis in vitro and vivo study

AIM

The aim of this study is to explain the effects and mechanism of miRNA-23a in lung injury which were induced by sepsis in vitro and vivo.

METHODS

In the vitro study, The BEAS-2B cells were divided into 4 groups: NC, MC, miRNA and miRNA + PTEN agonist groups. The cell proliferation and apoptosis of difference groups were measured by MTT and flow cytometry, the relative proteins expression of difference groups were measured by WB assay. In the vivo study, the rats were also divided into 4 groups: NC, MC, miRNA and miRNA + PTEN agonist groups. The miRNA-23a expression of difference groups were evaluated by ISH in lung tissues of rats. The cell apoptosis of difference groups were evaluated by TUNEL assay in lung tissues; the relative proteins expression of difference groups were evaluated by IHC assay.

RESULTS

Compared with NC group, the cell apoptosis rate of MC groups were significantly increased in vitro and vivo studies (P ＜ 0.05, respectively). The relative proteins (PTEN, PI3K, AKT and P53) expressions of MC group were significantly differences (P ＜ 0.05, respectively) compared with those of NC groups in vitro and vivo studies. However, with miRNA-23a infection, the cell apoptosis of miRNA group were significantly suppressed compared with MC groups, and the relative proteins (PTEN, PI3K, AKT and P53) of miRNA group were also significantly differences compared with MC groups in vitro and vivo studies (P ＜ 0.05, respectively).

CONCLUSION

The miRNA-23a has improved lung injury induced by sepsis via PTEN/PI3K/AKT/P53 pathway in vitro and vivo studies.

Deciphering cellular biological processes to clinical application: a new perspective for Tα1 treatment targeting multiple diseases

BACKGROUND

Thymosin alpha 1 (Tα1) is a well-recognized immune response modulator in a wide range of disorders, particularly infections and cancer. The bioinformatic analysis of public databases allows drug repositioning, predicting a new potential area of clinical intervention. We aimed to decipher the cellular network induced by Tα1 treatment to confirm present use and identify new potential clinical applications.

RESEARCH DESIGN AND METHODS

We used the transcriptional profile of human peripheral blood mononuclear cells treated in vitro with Tα1 to perform the enrichment network analysis by the Metascape online tools and the disease enrichment analysis by the DAVID online tool.

RESULTS

Networked cellular responses reflected Tα1 regulated biological processes including immune and metabolic responses, response to compounds and oxidative stress, ion homeostasis, peroxisome biogenesis and drug metabolic process. Beyond cancer and infections, the analysis evidenced the association with disorders such as kidney chronic failure, diabetes, cardiovascular, chronic respiratory, neuropsychiatric, neurodegenerative and autoimmune diseases.

CONCLUSIONS

In addition to the known ability to promote immune response pathways, the network enrichment analysis demonstrated that Tα1 regulates cellular metabolic processes and oxidative stress response. Notable, the analysis highlighted the association with several diseases, suggesting new translational implication of Tα1 treatment in pathological conditions unexpected until now.

Transcriptional Repression and Protein Degradation of the Ca2+-Activated K+ Channel KCa1.1 by Androgen Receptor Inhibition in Human Breast Cancer Cells

The large-conductance Ca²⁺-activated K⁺ channel K_Ca1.1 plays an important role in the promotion of breast cancer cell proliferation and metastasis. The androgen receptor (AR) is proposed as a therapeutic target for AR-positive advanced triple-negative breast cancer. We herein investigated the effects of a treatment with antiandrogens on the functional activity, activation kinetics, transcriptional expression, and protein degradation of K_Ca1.1 in human breast cancer MDA-MB-453 cells using real-time PCR, Western blotting, voltage-sensitive dye imaging, and whole-cell patch clamp recording. A treatment with the antiandrogen bicalutamide or enzalutamide for 48 h significantly suppressed (1) depolarization responses induced by paxilline (PAX), a specific K_Ca1.1 blocker and (2) PAX-sensitive outward currents induced by the depolarizing voltage step. The expression levels of K_Ca1.1 transcripts and proteins were significantly decreased in MDA-MB-453 cells, and the protein degradation of K_Ca1.1 mainly contributed to reductions in K_Ca1.1 activity. Among the eight regulatory β and γ subunits, LRRC26 alone was expressed at high levels in MDA-MB-453 cells and primary and metastatic breast cancer tissues, whereas no significant changes were observed in the expression levels of LRRC26 and activation kinetics of PAX-sensitive outward currents in MDA-MB-453 cells by the treatment with antiandrogens. The treatment with antiandrogens up-regulated the expression of the ubiquitin E3 ligases, FBW7, MDM2, and MDM4 in MDA-MB-453 cells, and the protein degradation of K_Ca1.1 was significantly inhibited by the respective siRNA-mediated blockade of FBW7 and MDM2. Based on these results, we concluded that K_Ca1.1 is an androgen-responsive gene in AR-positive breast cancer cells, and its down-regulation through enhancements in its protein degradation by FBW7 and/or MDM2 may contribute, at least in part, to the antiproliferative and antimetastatic effects of antiandrogens in breast cancer cells.

miR-181 regulates cisplatin-resistant non-small cell lung cancer via downregulation of autophagy through the PTEN/PI3K/AKT pathway

A number of miRNAs have been found to be abnormally expressed or mutated in numerous cancers and thus, are considered to act as oncogenes or tumor suppressor genes. The aim of the present study was to investigate the effect of miR-181 on cisplatin-resistant non-small cell lung cancer (NSCLC). In patients with cisplatin-resistant NSCLC, miR-181 expression was found to be markedly decreased. In addition, in the cisplatin-resistant human lung adenocarcinoma cell line A549/DDP, miR-181 downregulation promoted cell growth and metastasis and inhibited cell apoptosis, whereas miR-181 overexpression exerted the opposite effects. Furthermore, miR-181 downregulation suppressed LC3 and ATG5 protein expression in A549/DDP cells through suppression of the PTEN/PI3K/AKT/mTOR pathway, whereas miR-181 overexpression recovered LC3 and ATG5 protein expression by promoting PTEN/PI3K/AKT/mTOR signaling. In turn, PTEN inhibitors reduced the anticancer effects of miR-181 overexpression on A549/DDP cell growth via the regulation of autophagy through the PI3K/AKT/mTOR pathway. Therefore, miR-181 may be a novel and important regulator of cisplatin-resistant NSCLC by serving a role in the regulation of apoptosis, as an established rate-limiting miRNA target.

Thymosin α-1 does not correct F508del-CFTR in cystic fibrosis airway epithelia

In cystic fibrosis (CF), deletion of phenylalanine 508 (F508del) in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel causes misfolding and premature degradation. Considering the numerous effects of the F508del mutation on the assembly and processing of CFTR protein, combination therapy with several pharmacological correctors is likely to be required to treat CF patients. Recently, it has been reported that thymosin α-1 (Tα-1) has multiple beneficial effects that could lead to a single-molecule-based therapy for CF patients with F508del. Such effects include suppression of inflammation, improvement in F508del-CFTR maturation and gating, and stimulation of chloride secretion through the calcium-activated chloride channel (CaCC). Given the importance of such a drug, we aimed to characterize the underlying molecular mechanisms of action of Tα-1. In-depth analysis of Tα-1 effects was performed using well-established microfluorimetric, biochemical, and electrophysiological techniques on epithelial cell lines and primary bronchial epithelial cells from CF patients. The studies, which were conducted in 2 independent laboratories with identical outcome, demonstrated that Tα-1 is devoid of activity on mutant CFTR as well as on CaCC. Although Tα-1 may still be useful as an antiinflammatory agent, its ability to target defective anion transport in CF remains to be further investigated.

Hesperetin inhibits Eca-109 cell proliferation and invasion by suppressing the PI3K/AKT signaling pathway and synergistically enhances the anti-tumor effect of 5-fluorouracil on esophageal cancer in vitro and in vivo

Previously, we reported that hesperetin exhibited pro-apoptotic activity against esophageal cancer in vitro and in vivo. Here, we examined whether hesperetin inhibits cell proliferation and invasion and synergistically enhances the anti-tumor effect of 5-fluorouracil (5-FU) in esophageal cancer. Flow cytometry, EdU staining, and transwell invasion assays using Eca-109 cells showed that hesperetin induced cell cycle arrest at the G0/G1 phase and inhibited cell proliferation and invasion significantly. Moreover, hesperetin suppressed the expression of phosphorylated PI3K/AKT, cyclin D1, MMP-2, and MMP-9 and increased phosphorylated PTEN and p21 in Eca-109 cells. Hesperetin combined with 5-FU inhibited cell growth more effectively than did either drug alone in Eca-109 cells and in a xenograft mouse model. Hoechst 33258, Annexin V-PE/7-ADD double staining and TUNEL assay showed more apoptotic cells in the combination treatment group than in either individual treatment group. The combination down-regulated protein levels of Bcl-2 and up-regulated those of Bax, cleaved caspase-3, and cleaved caspase-9 more effectively than did either drug alone. These data suggest that hesperetin inhibited esophageal cancer cell proliferation and invasion by suppressing the PI3K/AKT signaling pathway. In conclusion, 5-FU and hesperetin exerted synergistic antitumor effects in vivo and in vitro and could constitute a novel therapeutic approach for esophageal cancer.

Effects of hesperetin on the proliferation and invasion of esophageal cancer cells and its synergistic anti-cancer effect with 5-FU.

Cell-free circulating tumor DNA analysis for breast cancer and its clinical utilization as a biomarker

Circulating tumor DNA (ctDNA) in the blood of cancer patients contains much information on genetic and epigenetic profiles associated with cancer development, progression, and response to therapy. Analysis of ctDNA provides an opportunity for non-invasive sampling of tumor DNA repetitiously and therefore advance precision medicine. Recent development in massively parallel sequencing and digital genomic techniques support the analytical and clinical validity of ctDNA as a promising 'liquid biopsy' in human cancer. In this review, we discussed the current status of cell-free ctDNA including ctDNA biology, recently developed techniques for ctDNA detection, breast cancer specific detecting strategies, with a focus on clinical applications of ctDNA-based biomarkers in breast oncology.

The regulatory role of aberrant Phosphatase and Tensin Homologue and Liver Kinase B1 on AKT/mTOR/c-Myc axis in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumor (pNET) is an uncommon type of pancreatic neoplasm. Low Phosphatase and Tensin Homologue (PTEN) expression and activation of the mechanistic target of rapamycin (mTOR) pathway have been noted in pNETs, and the former is associated with poor survival in pNET patients. Based on the results of the RADIANT-3 study, everolimus, an oral mTOR inhibitor, has been approved to treat advanced pNETs. However, the exact regulatory mechanism for the mTOR pathway in pNETs remains largely unknown. PTEN and liver kinase B1 (LKB1) are well-known for their regulatory role in the mTOR pathway. We evaluated the expression of PTEN and LKB1 in 21 pNET patients, and low PTEN and LKB1 expression levels were noted in 48% and 24% of the patients, respectively. Loss of PTEN and LKB1 synergistically promoted cell proliferation of pNET, attenuated the sensitivity of cells to mTOR inhibitors and enhanced c-Myc expression, which back-regulated PTEN, AKT, mTOR and its downstream effectors. For pNET cells with low expression levels of PTEN and LKB1, silencing the expression of c-Myc by shRNA reduced their proliferative rate, while adding either c-Myc inhibitor or AMP-activated protein kinase activator reversed their resistance to mTOR inhibitors in vitro and in vivo. Furthermore, high c-Myc expression was subsequently identified in 81% of pNETs, suggesting that up-regulation of c-Myc expression in pNETs may occur through PTEN/LKB1-dependent and PTEN/LKB1-independent regulation. The results delineated the regulation of PTEN and LKB1 on the AKT/mTOR/c-Myc axis and suggested that both c-Myc and mTOR are potential therapeutic targets for pNET.

MicroRNA-10a suppresses breast cancer progression via PI3K/Akt/mTOR pathway

Previous studies have demonstrated that microRNA-10a (miR-10a) regulates various opposing biological functions in breast cancer. The aim of the present study was to investigate the exact functions of miR-10a in the pathogenesis of breast cancer. miR-10a expression was initially detected in two human breast cancer cell lines, MCF-7 and MDA-MB-231 and a normal human mammary epithelial cell line MCF-10A. The proliferation, migration and apoptosis of breast cancer cells were analyzed using MTT assays, Transwell assays and flow cytometry, respectively, following transfection of MCF-7 and MDA-MB-231 cells with an miR-10a mimic or anti-miR-10a. The expression of phosphorylated (p-)protein kinase B (Akt), p-mammalian target of rapamycin (p-mTOR), p-ribosomal protein S6 kinase β-1 (p-p70S6K), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), Cytochrome C (Cyt C), B-cell lymphoma 2 (Bcl-2), BCL-2 associated X, apoptosis regulator (Bax), and cleaved caspase-3 were analyzed by western blotting. The migration of MCF-7 cells pretreated with an mTOR inhibitor CCI-779, was detected using a Transwell assay. Relative miR-10a expression was significantly elevated in MDA-MB-231 breast cancer cells and was at its highest levels in MCF-7 cells. Transfection with the miR-10a mimic significantly inhibited proliferation and migration, and promoted the apoptosis of breast cancer cells. Furthermore, upregulation of miR-10a markedly suppressed the levels of p-Akt, p-mTOR, p-p70S6K, and PIK3CA, and increased the expression of Cyt C, cleaved caspase-3, and the ratio of Bax/Bcl-2. Anti-miR-10a had the opposite effects. In addition, CCI-779 reversed the effect of anti-miR-10a on the migration of MCF-7 cells in a dose-dependent manner. In conclusion, miR-10a is downregulated in high aggressive breast cancer cells. miR-10a inhibited the proliferation and migration, and promoted apoptosis of breast cancer cells via phosphoinositide/Akt/mTOR signaling, and the mitochondrial apoptotic pathway.

miRNA-125b regulates apoptosis of human non-small cell lung cancer via the PI3K/Akt/GSK3β signaling pathway

The present investigation demonstrated that regulation of microRNA (miR)-125b affected the apoptosis of human non-small cell lung cancer (NSCLC) through targeting of the PI3K/Akt and Wnt/β-catenin signaling pathways. The expression of miR-125b was assessed in patients with NSCLC, which demonstrated that miR-125b expression in NSCLC tissue was higher than that in para-carcinoma tissue. Furthermore, survival analysis of patients with NSCLC over 3 years indicated that the overall survival (OS) and disease-free survival (DFS) rates of patients with low miR-125b expression were higher than those of patients with high miR-125b expression. Proliferation and apoptosis assays were subsequently conducted in the human NSCLC cell line A549 using MTT assay and Annexin V-FITC/PI kits, respectively. Caspase-3 activity ELISA and western blot analysis were also used to assess caspase-3 activity and the protein expression of Bax, Akt, phosphorylated (p)-Akt, p-GSK3β, Wnt and β-catenin. It was observed that downregulation of miR-125b inhibited the proliferation and induced the apoptosis of A549 cells. Downregulation of miR-125b also suppressed the protein expression of p-Akt, Wnt and β-catenin, and increased caspase-3 activity and Bax protein expression in A549 cells. In addition, downregulation of miR-125b combined with the PI3K inhibitor LY294002 enhanced cell growth inhibition, suppression of p-GSK3β, Wnt and β-catenin protein expression and promotion of caspase-3 activity in A549 cells. These results revealed that the downregulation of miR-125b regulates apoptosis in human NSCLC through the suppression of the PI3K/Akt/GSK3β and Wnt/β-catenin signaling pathways.

Crude terpene glycoside component from Radix paeoniae rubra protects against isoproterenol-induced myocardial ischemic injury via activation of the PI3K/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Radix paeoniae rubra, also known as chishao (CS), is a frequently used traditional Chinese medicine that can promote blood circulation to remove blood stasis. It has been widely used for the prevention and treatment of cardiovascular diseases in China. Although terpene glycoside (TG), the major component in CS, has been shown to possess cardioprotective properties, the mechanism underlying CS-TG's preventive effect against myocardial ischemia injury is unknown. This study was conducted to explore the protective and curative effects of CS-TG against isoproterenol (ISO)-induced myocardial ischemic injury in rats and investigate the underlying myocardial protective mechanisms.

MATERIALS AND METHODS

A rat model of ISO-induced myocardial ischemia was established to evaluate the protective effect of CS-TG in ameliorating heart injury. Myocardial ischemia was induced by administering ISO (40mg/kg/d) subcutaneously for 2 days. Serum was collected and analyzed for the levels of different cardiac biomarkers, and heart tissues were isolated and prepared for ATP analysis, glycogen content determination, histopathology assay, and ultrastructure observation. The regulatory effects of CS-TG on myocardial apoptosis in rats were studied by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of cleaved caspase-3, Bax, and Bcl-2 were detected by western blotting. Furthermore, in vitro experiments were conducted to examine whether the CS-TG's cardioprotective effects were linked to the inhibition of apoptosis via activation of the phosphoinositide-3-kinase/serine-threonine kinase AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway.

RESULTS

CS-TG (300mg/kg/d) significantly decreased serum levels of creatine kinase and lactate dehydrogenase in ISO-induced myocardial ischemic rats. Analysis of ATP and glycogen contents, myocardial ultrastructure, and pathological examination showed that CS-TG (300mg/kg/d) significantly improved energy metabolism and alleviated myocardial injury in vivo. In addition, the expression of p-AKT and p-mTOR in rats subjected to CS-TG significantly elevated, while the levels of caspase-3 and Bax/Bcl-2 dramatically reduced. Moreover, treatment with LY294002, a PI3K inhibitor, abrogated CS-TG (200μg/mL) induced down-regulation of cleaved caspase-3, Bax/Bcl-2 in the serum.

CONCLUSIONS

CS-TG protects the heart from ISO-induced myocardial ischemia, potentially by improving cardiac energy metabolism and inhibiting cardiomyocyte apoptosis via activation of the PI3K/AKT/mTOR signaling pathway. Thus, CS -TG might be a potential therapeutic candidate for the prevention and treatment of myocardial ischemia.

Circulating microRNA-194 regulates human melanoma cells via PI3K/AKT/FoxO3a and p53/p21 signaling pathway

In the present study, we analyzed the role of microRNA-194 circulating regulated human melanoma cell growth. We found that microRNA-194 expression was markedly suppressed in human melanoma patients, compared with negative control group. Next, disease-free survival (DFS) and overall survival (OS) of high expression in human melanoma patients was higher than those of low expression in human melanoma patients. MicroRNA-194 overexpression inhibited cell proliferation, induced apoptosis, increased caspase-3/-9 activities and promoted Bax/Bcl-2 of human melanoma cells. Furthermore, microRNA-194 overexpression also suppressed PI3K/AKT/FoxO3a signaling pathway and induced p53/p21 signaling pathway. PI3K inhibitor, suppressed PI3K, phosphorylation-AKT, FoxO3a protein expression and increased the effects of microRNA-194 overexpression on cell growth, apoptosis, caspase-3/-9 activities and Bax/Bcl-2 protein expression of human melanoma cells through the induction of p53/p21 signaling pathway. Taken together, these data indicate that circulating microRNA-194 regulated human melanoma cells via PI3K/AKT/FoxO3a and p53/p21 signaling pathway.

Impact on Autophagy and Ultraviolet B Induced Responses of Treatment with the MTOR Inhibitors Rapamycin, Everolimus, Torin 1, and pp242 in Human Keratinocytes

The mechanistic target of Rapamycin (MTOR) protein is a crucial signaling regulator in mammalian cells that is extensively involved in cellular biology. The function of MTOR signaling in keratinocytes remains unclear. In this study, we detected the MTOR signaling and autophagy response in the human keratinocyte cell line HaCaT and human epidermal keratinocytes treated with MTOR inhibitors. Moreover, we detected the impact of MTOR inhibitors on keratinocytes exposed to the common carcinogenic stressors ultraviolet B (UVB) and UVA radiation. As a result, keratinocytes were sensitive to the MTOR inhibitors Rapamycin, everolimus, Torin 1, and pp242, but the regulation of MTOR downstream signaling was distinct. Next, autophagy induction only was observed in HaCaT cells treated with Rapamycin. Furthermore, we found that MTOR signaling was insensitive to UVB but sensitive to UVA radiation. UVB treatment also had no impact on the inhibition of MTOR signaling by MTOR inhibitors. Finally, MTOR inhibition by Rapamycin, everolimus, or pp242 did not affect the series of biological events in keratinocytes exposed to UVB, including the downregulation of BiP and PERK, activation of Histone H2A and JNK, and cleavage of caspase-3 and PARP. Our study demonstrated that MTOR inhibition in keratinocytes cannot always induce autophagy, and the MTOR pathway does not play a central role in the UVB triggered cellular response.

Mechanism of immune evasion in breast cancer

Breast cancer (BC) is the most common malignant tumor among women, with high morbidity and mortality. Its onset, development, metastasis, and prognosis vary among individuals due to the interactions between tumors and host immunity. Many diverse mechanisms have been associated with BC, with immune evasion being the most widely studied to date. Tumor cells can escape from the body’s immune response, which targets abnormal components and foreign bodies, using different approaches including modification of surface antigens and modulation of the surrounding environment. In this review, we summarize the mechanisms and factors that impact the immunoediting process and analyze their functions in detail.

Ursolic acid induced anti-proliferation effects in rat primary vascular smooth muscle cells is associated with inhibition of microRNA-21 and subsequent PTEN/PI3K

This study focused on the anti-proliferation effects of ursolic acid (UA) in rat primary vascular smooth muscle cells (VSMCs) and investigated underlying molecular mechanism of action. Rat primary VSMCs were pretreated with UA (10, 20 or 30μM) or amino guanidine (AG, 50μM) for 12h or with PI3K inhibitor LY294002 for 30min or with Akt inhibitor MK2206 for 24h, then 10% fetal bovine serum was used to induce proliferation. CCK-8 was used to assess cell proliferation. To explore the mechanism, cells were treated with UA (10, 20 or 30μM), LY294002 or MK2206, or transient transfected to inhibit miRNA-21 (miRNA-21) or to overexpress PTEN, then quantitative real-time PCR was used to assess the mRNA levels of miRNA-21 and phosphatase and tensin homolog (PTEN) for cells treated with UA or miRNA-21 inhibitor; western blotting was used to measure the protein levels of PTEN and PI3K. UA exerted significant anti-proliferation effects in rat primary VSMCs. Furthermore, UA inhibited the expression of miRNA-21 and subsequently enhanced the expression of PTEN. PTEN was found to inhibit the expression of PI3K. In conclusion, UA exerts anti-proliferation effects in rat primary VSMCs, which is associated with the inhibition of miRNA-21 expression and modulation of PTEN/PI3K signaling pathway.

Cold-water extracts of Grifola frondosa and its purified active fraction inhibit hepatocellular carcinoma in vitro and in vivo

Mushrooms are used in traditional Chinese medicine to treat a variety of diseases. Grifola frondosa (GF) is an edible mushroom indigenous to many Asian countries with a large fruiting body characterized by overlapping caps. In particular, GF is known for its anti-tumor activity, which has been targeted by scientific and clinical research. This study aimed to investigate the effects of the cold-water extract of GF (GFW) and its active fraction (GFW-GF) on autophagy and apoptosis, and the underlying mechanisms in vitro and in vivo Our results revealed that GFW and GFW-GF inhibited phosphatidylinositol 3-kinase (PI3K) and stimulated c-Jun N-terminal kinase (JNK) pathways, thereby inducing autophagy. We also demonstrated that GFW and GFW-GF inhibited proliferation, induced cell cycle arrest, and apoptosis in Hep3B hepatoma cells. GFW and GFW-GF markedly arrested cells in S phase and promoted cleavage of caspase-3 and -9. In addition, GFW and GFW-GF decreased the expression levels of the anti-apoptotic proteins protein kinase B and extracellular signal-regulated kinase. We also found that GFW significantly inhibited tumor growth in nude mice implanted with Hep3B cells. Our work demonstrates that GF and its active fraction inhibit hepatoma growth by inducing autophagy and apoptosis.

CrossHub: a tool for multi-way analysis of The Cancer Genome Atlas (TCGA) in the context of gene expression regulation mechanisms

The contribution of different mechanisms to the regulation of gene expression varies for different tissues and tumors. Complementation of predicted mRNA–miRNA and gene–transcription factor (TF) relationships with the results of expression correlation analyses derived for specific tumor types outlines the interactions with functional impact in the current biomaterial. We developed CrossHub software, which enables two-way identification of most possible TF–gene interactions: on the basis of ENCODE ChIP-Seq binding evidence or Jaspar prediction and co-expression according to the data of The Cancer Genome Atlas (TCGA) project, the largest cancer omics resource. Similarly, CrossHub identifies mRNA–miRNA pairs with predicted or validated binding sites (TargetScan, mirSVR, PicTar, DIANA microT, miRTarBase) and strong negative expression correlations. We observed partial consistency between ChIP-Seq or miRNA target predictions and gene–TF/miRNA co-expression, demonstrating a link between these indicators. Additionally, CrossHub expression-methylation correlation analysis can be used to identify hypermethylated CpG sites or regions with the greatest potential impact on gene expression. Thus, CrossHub is capable of outlining molecular portraits of a specific gene and determining the three most common sources of expression regulation: promoter/enhancer methylation, miRNA interference and TF-mediated activation or repression. CrossHub generates formatted Excel workbooks with the detailed results. CrossHub is freely available at https://sourceforge.net/projects/crosshub/.

Neuroprotective impact of prothymosin alpha-derived hexapeptide against retinal ischemia-reperfusion

Prothymosin alpha (ProTα) has robustness roles against brain and retinal ischemia or serum-starvation stress. In the ProTα sequence, the active core 30-amino acid peptide/P30 (a.a.49-78) is necessary for the original neuroprotective actions against ischemia. Moreover, the 9-amino acid peptide sequence/P9 (a.a.52-60) in P30 still shows neuroprotective activity against brain and retinal ischemia, though P9 is less potent than P30. As the previous structure-activity relationship study for ProTα may not be enough, the possibility still exists that any sequence smaller than P9 retains potent neuroprotective activity. When different P9- and P30-related peptides were intravitreally injected 24h after retinal ischemia in mice, the 6-amino acid peptide/P6 (NEVDEE, a.a.51-56) showed potent protective effects against ischemia-induced retinal functional deficits, which are equipotent to the level of P30 peptide in electroretinography (ERG) and histological damage in Hematoxylin and Eosin (HE) staining. Further studies using ERG and HE staining suggested that intravitreal or intravenous (i.v.) injection with modified P6 peptide/P6Q (NEVDQE) potently inhibited retinal ischemia-induced functional and histological damage. In an immunohistochemical analysis, the ischemia-induced loss of retinal ganglion, bipolar, amacrine and photoreceptor cells were inhibited by a systemic administration with P6Q peptide 24h after the ischemic stress. In addition, systemic post-treatment with P6Q peptide significantly inhibited retinal ischemia-induced microglia and astrocyte activation in terms of increased ionized calcium-binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) intensity, respectively, as well as their morphological changes, increased number and migration. Thus, this study demonstrates the therapeutic significance of modified P6 peptide P6Q (NEVDQE) derived from 6-amino acid peptide (P6) in ProTα against ischemic damage.

Inactivation of PI3-K/Akt and reduction of SP1 and p65 expression increase the effect of solamargine on suppressing EP4 expression in human lung cancer cells

BACKGROUND

Lung cancer is the most common cause of cancer-related deaths worldwide. Natural phytochemicals from traditional medicinal plants such as solamargine have been shown to have anticancer properties. The prostaglandin E2 receptor EP4 is highly expressed in human cancer, however, the functional role of EP4 in the occurrence and progression of non small cell lung cancer (NSCLC) remained to be elucidated.

METHODS

Cell viability was measured by MTT assays. Western blot was performed to measure the phosphorylation and protein expression of PI3-K downstream effector Akt, transcription factors SP1, p65, and EP4. Quantitative real-time PCR (qRT-PCR) was used to examine the mRNA levels of EP4 gene. Exogenous expression of SP1, p65, and EP4 genes was carried out by transient transfection assays. EP4 promoter activity was measured by Dual Luciferase Reporter Kit.

RESULTS

We showed that solamargine inhibited the growth of lung cancer cells. Mechanistically, we found that solamargine decreased the phosphorylation of Akt, the protein, mRNA expression, and promoter activity of EP4. Moreover, solamargine inhibited protein expression of SP1 and NF-κB subunit p65, all of which were abrogated in cells transfected with exogenous expressed Akt. Intriguingly, exogenous expressed SP1 overcame the effect of solamargine on inhibition of p65 protein expression, and EP4 protein expression and promoter activity. Finally, exogenous expressed EP4 feedback reversed the effect of solamargine on phosphorylation of Akt and cell growth inhibition.

CONCLUSION

Our results show that solamargine inhibits the growth of human lung cancer cells through inactivation of Akt signaling, followed by reduction of SP1 and p65 protein expression. This results in the inhibition of EP4 gene expression. The cross-talk between SP1 and p65, and the positive feedback regulatory loop of PI3-K/Akt signaling by EP4 contribute to the overall responses of solamargine in this process. This study unveils a novel mechanism by which solamargine inhibits growth of human lung cancer cells.

Single Cell RNA-Sequencing of Pluripotent States Unlocks Modular Transcriptional Variation

Embryonic stem cell (ESC) culture conditions are important for maintaining long-term self-renewal, and they influence cellular pluripotency state. Here, we report single cell RNA-sequencing of mESCs cultured in three different conditions: serum, 2i, and the alternative ground state a2i. We find that the cellular transcriptomes of cells grown in these conditions are distinct, with 2i being the most similar to blastocyst cells and including a subpopulation resembling the two-cell embryo state. Overall levels of intercellular gene expression heterogeneity are comparable across the three conditions. However, this masks variable expression of pluripotency genes in serum cells and homogeneous expression in 2i and a2i cells. Additionally, genes related to the cell cycle are more variably expressed in the 2i and a2i conditions. Mining of our dataset for correlations in gene expression allowed us to identify additional components of the pluripotency network, including Ptma and Zfp640, illustrating its value as a resource for future discovery.

Lentiviral-Mediated Short Hairpin RNA Knockdown of MTDH Inhibits Cell Growth and Induces Apoptosis by Regulating the PTEN/AKT Pathway in Hepatocellular Carcinoma

The activation of oncogenes and the loss of tumor suppressor genes are believed to play critical roles in the pathogenesis of human hepatocellular carcinoma (HCC). Metaherin (MTDH), also called astrocyte elevated gene-1 (AEG-1), is frequently amplified in a variety of cancers, but the roles of MTDH with regard to growth and apoptosis in HCC have not yet been studied. In the present study, we first analyzed the expression of MTDH in HCC samples. We found that MTDH protein levels are higher in most HCC cancerous tissues compared with their matched adjacent non-tumor tissues. Additionally, the MTDH mRNA was also higher in HCC tissues compared to their matched adjacent non-tumor tissues. Knockdown of the endogenous MTDH using small interfering RNA further showed that deficiency of MTDH suppressed cell growth and caused apoptosis in HCC cells. Knockdown MTDH promoted PTEN and p53 expression in HCC cells and inhibited AKT phosphorylation. Knockdown MTDH also inhibited tumor growth in vivo. All these results indicated that MTDH protein levels in most HCC tissues are higher than non-tumor tissues, and knockdown of MTDH inhibited growth and induced apoptosis in HCC cells through the activation of PTEN. Therefore, MTDH might be an effective targeted therapy gene for HCC.