Role of NF-κB/ICAM-1, JAK/STAT-3, and apoptosis signaling in the anticancer effect of tangeretin against urethane-induced lung cancer in BALB/c mice

Leptin promotes proliferation of human undifferentiated spermatogonia by activating the PI3K/AKT/mTOR pathway

BACKGROUND

Male infertility is a common disease affecting male reproductive health. Leptin is an important hormone that regulates various physiological processes, including reproductive function. However, few experimental studies have been carried out to elucidate the mechanism of leptin's effects on male reproductive function.

OBJECTIVE

The purpose of this study was to investigate the effects of leptin on testicular spermatogenesis and its mechanism, so as to provide potential targets for the treatment of patients with spermatogenic dysfunction.

METHODS

Testicular tissues were collected from eight prostate cancer patients undergoing surgical castration. GPR125-positive spermatogonia were isolated by two consecutive magnetic activated cell sorting (MACS), followed by incubation with conditioned medium. To identify the signaling pathway(s) involved in the effects of leptin, undifferentiated spermatogonia were treated with different concentrations of leptin and antagonists of leptin-related pathways. The proliferative effect of leptin was evaluated by cell counting using a hemocytometer. Expressions of p-AKT, p-ERK, p-STAT, and p-S6K were determined by western blotting analysis.

RESULTS

Leptin promoted the growth of human GPR125-positive spermatogonia in a concentration-dependent manner. The most significant proliferative effect was observed using 100 ng/mL leptin after 6 days of culture. Leptin significantly increased the phosphorylation of STAT3, AKT, and ERK in undifferentiated spermatogonia. Phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 inhibited the leptin-induced activation of AKT, ERK, and downstream S6K. Treatment with the mammalian target of rapamycin (mTOR) inhibitor rapamycin also inhibited S6K phosphorylation. Moreover, both LY294002 and rapamycin were found to inhibit the leptin-induced proliferation of undifferentiated spermatogonia. These results suggested that the leptin-induced proliferation of GPR125-positive spermatogonia was dependent on the PI3K/AKT/mTOR pathway. Further exploration of proliferation and apoptotic markers suggested that leptin may alleviate cell apoptosis by regulating the expression of Bax and FasL.

CONCLUSIONS

A certain concentration of leptin (25∼100 ng/mL) could promote proliferation of undifferentiated spermatogonia, which was mediated by PI3K/AKT/mTOR pathway.

Proof-of-Concept Study on the Use of Tangerine-Derived Nanovesicles as siRNA Delivery Vehicles toward Colorectal Cancer Cell Line SW480

In the last years, the field of nanomedicine and drug delivery has grown exponentially, providing new platforms to carry therapeutic agents into the target sites. Extracellular vesicles (EVs) are ready-to-use, biocompatible, and non-toxic nanoparticles that are revolutionizing the field of drug delivery. EVs are involved in cell-cell communication and mediate many physiological and pathological processes by transferring their bioactive cargo to target cells. Recently, nanovesicles from plants (PDNVs) are raising the interest of the scientific community due to their high yield and biocompatibility. This study aims to evaluate whether PDNVs may be used as drug delivery systems. We isolated and characterized nanovesicles from tangerine juice (TNVs) that were comparable to mammalian EVs in size and morphology. TNVs carry the traditional EV marker HSP70 and, as demonstrated by metabolomic analysis, contain flavonoids, organic acids, and limonoids. TNVs were loaded with DDHD1-siRNA through electroporation, obtaining a loading efficiency of 13%. We found that the DDHD1-siRNA complex TNVs were able to deliver DDHD1-siRNA to human colorectal cancer cells, inhibiting the target expression by about 60%. This study represents a proof of concept for the use of PDNVs as vehicles of RNA interference (RNAi) toward mammalian cells.

High-Mobility Group Box 1 Overexpression Predicts a Poor Prognosis and Promotes Epithelial-Mesenchymal Transition in Gastric Cancer by Activating TLR4/NF-κB Signaling

INTRODUCTION

The molecular mechanism of high-mobility group box 1 (HMGB1) promoting the epithelial-mesenchymal transition (EMT) of gastric cancer (GC) has not been known well. This study aimed to explore the clinical effects of HMGB1 expression levels on the clinicopathological characteristics of patients with GC and to uncover the potential molecular mechanism which promotes tumor progression.

METHODS

The expression levels of HMGB1 in 125 patients with GC were detected by immunohistochemistry and Western blotting. Univariate and multivariate analyses were performed to evaluate the relationship between HMGB1 expression and clinical characteristics of patients with GC. Stable overexpression (over-HMGB1) and knockdown (sh-HMGB1) GC cell lines (AGS and MKN-45) were used to determine the effects of HMGB1 on the activation of TLR4/NF-κB signaling. Differences were considered statistically significant at p < 0.05 in two sides.

RESULTS

HMGB1 is highly expressed in GC tissues and cell lines. High HMGB1 expression (HR = 1.89, 95% CI: 1.44-2.39, p = 0.001) was an independent risk factor for overall survival in patients with GC. Downregulation of HMGB1 resulted in downregulation of TLR4 and NF-κB subunit (p-p65 and p-IκBα) expression, whereas the upregulated expression of HMGB1 led to increased expression of TLR4 and NF-κB subunits. Overexpression of HMGB1 promotes the upregulation of EMT-TF expression, which enhances the proliferation and migration abilities of GC cell lines.

CONCLUSION

HMGB1 is highly expressed in GC tissues and is associated with a poorer prognosis in patients with GC. HMGB1 activates the TLR4/NF-κB signaling pathway to promote EMT progression in GC cell lines. HMGB1 may be a critical molecule in prognosis prediction and a therapeutic target for patients with GC.

Lung cancer treatment potential and limits associated with the STAT family of transcription factors

Lung cancer is one of the mortal cancers and the leading cause of cancer-related mortality, with a cancer survival rate of fewer than 5% in developing nations. This low survival rate can be linked to things like late-stage detection, quick postoperative recurrences in patients receiving therapy, and chemoresistance developing against various lung cancer treatments. Signal transducer and activator of transcription (STAT) family of transcription factors are involved in lung cancer cell proliferation, metastasis, immunological control, and treatment resistance. By interacting with specific DNA sequences, STAT proteins trigger the production of particular genes, which in turn result in adaptive and incredibly specific biological responses. In the human genome, seven STAT proteins have been discovered (STAT1 to STAT6, including STAT5a and STAT5b). Many external signaling proteins can activate unphosphorylated STATs (uSTATs), which are found inactively in the cytoplasm. When STAT proteins are activated, they can increase the transcription of several target genes, which leads to unchecked cellular proliferation, anti-apoptotic reactions, and angiogenesis. The effects of STAT transcription factors on lung cancer are variable; some are either pro- or anti-tumorigenic, while others maintain dual, context-dependent activities. Here, we give a succinct summary of the various functions that each member of the STAT family plays in lung cancer and go into more detail about the advantages and disadvantages of pharmacologically targeting STAT proteins and their upstream activators in the context of lung cancer treatment.