Telocinobufagin Has Antitumor Effects in Non-Small-Cell Lung Cancer by Inhibiting STAT3 Signaling

α-Mangostin Exhibits Antitumor Activity Against NCI-H1975 Cells via the EGFR/STAT3 Pathway: An Experimental and Molecular Simulation Study

Non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations have brought great challenges to the medical treatment in the world. Current treatment strategies, such as EGFR tyrosine kinase inhibitors (TKIs), have reached certain achievements, however, patients inevitably experienced resistance after undergoing a period of treatment with these drugs. Hence, more novel therapy strategies need to be urgently developed. Natural compounds have become popular topics in drug development. α-Mangostin, which is derived from mangosteen, possesses multiple biological properties, yet the antitumor mechanism against NSCLC has not been further elucidated. In this study, an MTT assay, Western blotting, a colony formation assay, and flow cytometry were performed to detect the antitumor activity of α-Mangostin on NSCLC cell NCI-H1975. Molecular docking and molecular dynamics simulations were performed to analyze the interactions between α-Mangostin and the core target proteins. The results indicated that α-Mangostin exerts its antitumor activity by inhibiting cell proliferation and migration, reducing cell cycle arrest, promoting cell apoptosis, and regulating the phosphorylation expression levels of EGFR and signal transducer and activator of transcription 3 (STAT3). Moreover, the results of the molecular simulation study revealed the potential binding mode of α-Mangostin to EGFR and STAT3. In summary, we characterized that α-Mangostin may be used as a potent pro-drug against NSCLC via the EGFR/STAT3 pathway.

Telocinobufagin suppresses malignant metastasis of undifferentiated thyroid carcinoma via modulation of the LARP1-mTOR pathway

Metastasis is the trigger of death in anaplastic thyroid cancer (ATC) patients, yet the specific mechanisms at play are still largely enigmatic. While the involvement of LARP1 in the metastatic process of various cancers has been documented, there is a noticeable gap in the literature regarding its potential influence on ATC metastasis. Molecular studies probed LARP1 expression within ATC cells, with subsequent in vitro experiments examining the effects of LARP1 on ATC cell metastasis and the mTOR signaling cascade. A suite of assays, including colony formation, scratch wound healing, transwell invasion, and cell adhesion, was used to assess cell growth, movement, invasion, and attachment. Western Blot determined the expression levels of epithelial-mesenchymal transition (EMT) markers (E-cadherin, Vimentin, N-cadherin) and proteins implicated in metastasis (MMP-2, MMP-9), along with mTOR and p-mTOR. The affinity of Telocinobufagin (TBG) from Yuanhua Toad Essence for LARP1 was investigated through molecular docking, with CETSA assays providing subsequent validation. Further cellular experiments substantiated the influence of TBG on ATC cell metastasis and modulation in the mTOR pathway. LARP1 levels were heightened in ATC cells, and its depletion effectively curbs their proliferative, migratory, invasive, and adhesive activities. With LARP1 knockdown, we also observed that the onset of EMT and metastatic processes was thwarted, as was the mTOR pathway. Subsequent research has uncovered that TBG formed a physical complex with LARP1, allowing it to target and suppress the mTOR pathway, thus preventing the metastasis of ATC. The simultaneous overexpression of LARP1, however, lessened the ability of TBG to inhibit ATC metastasis. This study highlights the importance of TBG binding to LARP1 in the mediation of the mTOR signaling pathway, a key process in the inhibition of ATC cell metastasis. This discovery introduces a new target for the diagnosis of ATC and enlightens the consideration of TBG as a treatment for ATC metastasis.

Coccinic acid exhibits anti-tumor efficacy against NSCLC harboring EGFR L858R/T790M mutation via the EGFR/STAT3 pathway

Epidermal growth factor receptor (EGFR) is a starring target for the treatment of non-small cell lung cancer (NSCLC). EGFR tyrosine kinase inhibitors (EGFR-TKIs) have been used to treat NSCLC patients with EGFR-activating mutations. However, most patients invariably develop resistance to these agents due to the occurrence of novel mutations at the EGFR kinase domain. There is an urgent need to develop more effective therapy strategies to provide more selection for patients with NSCLC. Coccinic acid was reported to exerts potential anti-tumor effects, but its mechanism has not been elucidated and warrants investigation. In this study, coccinic acid was shown to inhibit cell proliferation on cells harboring L858R/T790M mutant EGFR by suppressing p-EGFR and p-STAT3. It was also shown that coccinic acid promoted cell cycle distribution and showed a potent apoptosis-inducing efficacy. Further results in vivo assays demonstrated that coccinic acid reduced tumor growth of NCI-H1975 xenograft in nude mice via the EGFR/STAT3 signaling. Moreover, these effects are involving in the binding of coccinic acid to the EGFR extracellular domain. In conclusion, our finding demonstrated that coccinic acid may be utilized as a potential novel candidate for NSCLC with EGFR L858R/T790M mutation.

Bufadienolides from Chansu Injection Synergistically Enhances the Antitumor Effect of Erlotinib by Inhibiting the KRAS Pathway in Pancreatic Cancer

Background and Objectives: The Chansu injection (CSI), a sterile aqueous solution derived from Chansu, is applied in clinical settings to support antitumor and anti-radiation treatments. CSI's principal active components, bufadienolides (≥90%), demonstrate potential effects on pancreatic cancer (PDAC), but their underlying mechanisms remain unclear. This study aimed to elucidate the antitumor effects and pathways associated with CSI in PDAC. Methods: Network pharmacology and bioinformatics analyses explored CSI's mechanisms against PDAC. MTT, colony-formation, and migration assays evaluated CSI's impact on proliferation and migration in PANC-1 and MIA PACA-2 cells, both as a single agent and in combination with erlotinib (EGFR inhibitor). Cell cycle analysis employed flow cytometry. Animal experiments were performed on tumor-bearing mice, with targets and pathways assessed via molecular docking and western blotting. Results: CSI treatment suppressed PDAC cell proliferation and migration by inducing G2/M phase arrest. Network pharmacology, bioinformatics, and molecular docking indicated that CSI's anti-PDAC effects may involve EGFR pathway modulation, with CSI lowering p-EGFR/KRAS/p-ERK1/2 pathway expressions in PDAC cells. Additionally, sustained KRAS activation in mediating erlotinib resistance in PDAC and CSI potentiated erlotinib's antitumor effects through enhanced KRAS and p-ERK1/2 inhibition. CSI also enhanced erlotinib's efficacy in tumor-bearing mice without causing detectable toxicity in renal, cardiac, or hepatic tissues at therapeutic doses. Conclusions: CSI as an adjuvant used in antitumor and anti-radiation therapies enhanced erlotinib's antitumor effects through modulation of the KRAS pathway. CSI and erlotinib's synergistic interaction represents a promising approach for addressing erlotinib resistance in PDAC treatment.

Structure, function, signaling pathways and clinical therapeutics: The translational potential of STAT3 as a target for cancer therapy

Cancer remains one of the most difficult human diseases to overcome because of its complexity and diversity. Signal transducers and transcriptional activators 3 (STAT3) protein has been found to be overexpressed in a wide range of cancer types. Hyperactivation of STAT3 is particularly associated with low survival in cancer patients. This review summarizes the specific molecular mechanisms of STAT3 in cancer development. STAT3 is activated by extracellular signals in the cytoplasm, interacts with different enzymes in the nucleus, mitochondria or endoplasmic reticulum, and subsequently participates in cancer development. The phosphorylated STAT3 at tyrosine 705 site (YP-STAT3) enters the nucleus and regulates a number of tumor-related biological processes such as angiogenesis, migration invasion, cell proliferation and cancer cell stemness. In contrast, the phosphorylated STAT3 at serine 727 site (SP-STAT3) is found on the mitochondria, affects electron respiration transport chain activity and thereby prevents tumor cell apoptosis. SP-STAT3 also appears on the mitochondria-associated endoplasmic reticulum membrane, influences the flow of Ca2+, and affects tumor progression. In addition, we summarize the direct and indirect inhibitors of STAT3 which are currently undergoing clinical studies. Some of them such as TTI101 and BBI608 have been approved by the FDA for the treatment of certain cancers. All in all, STAT3 plays an important role in cancer progression and becomes a potential target for cancer treatment.

Cytochrome P450 Mining for Bufadienolide Diversification

Bufadienolides are a class of steroids with a distinctive α-pyrone ring at C17, mostly produced by toads and consisting of over 100 orthologues. They exhibit potent cardiotonic and antitumor activities and are active ingredients of the traditional Chinese medicine Chansu and Cinobufacini. Direct extraction from toads is costly, and chemical synthesis is difficult, limiting the accessibility of active bufadienolides with diverse modifications and trace content. In this work, based on the transcriptome and genome analyses, using a yeast-based screening platform, we obtained eight cytochrome P450 (CYP) enzymes from toads, which catalyze the hydroxylation of bufalin and resibufogenin at different sites. Moreover, a reported fungal CYP enzyme Sth10 was found functioning in the modification of bufalin and resibufogenin at multiple sites. A total of 15 bufadienolides were produced and structurally identified, of which six were first discovered. All of the compounds were effective in inhibiting the proliferation of tumor cells, especially 19-hydroxy-bufalin (2) and 1β-hydroxy-bufalin (3), which were generated from bufalin hydroxylation catalyzed by CYP46A35. The catalytic efficiency of CYP46A35 was improved about six times and its substrate diversity was expanded to progesterone and testosterone, the common precursors for steroid drugs, achieving their efficient and site-specific hydroxylation. These findings elucidate the key modification process in the synthesis of bufadienolides by toads and provide an effective way for the synthesis of unavailable bufadienolides with site-specific modification and active potentials.

Telocinobufagin, a PLK1 suppressor that inhibits tumor growth and metastasis by modulating CDC25c and CTCF in HNSCC cells

BACKGROUND

The high metastasis and mortality rates of head and neck squamous cell carcinoma (HNSCC) urgently require new treatment targets and drugs. A steroidal component of ChanSu, telocinobufagin (TBG), was verified to have anti-cancer effects in various tumors, but its activity and mechanism in anti-HNSCC were still unknown.

PURPOSE

This study tried to demonstrate the anti-tumor effect of TBG on HNSCC and verify its potential mechanism.

METHODS

The effect of TBG on cell proliferation and metastasis were performed and the TBG changed genes were detected by RNA-seq analysis in HNSCC cells. The GSEA and PPI analysis were used to identify the pathways targeted for TBG-regulated genes. Meanwhile, the mechanism of TBG on anti-proliferative and anti-metastasis were investigated in vitro and in vivo.

RESULTS

The in vitro and in vivo experiments confirmed that TBG has favorable anti-tumor effects by induced G2/M phase arrest and suppressed metastasis in HNSCC cells. Further RNA-seq analysis demonstrated the genes regulated by TBG were enriched at the G2/M checkpoint and PLK1 signaling pathway. Then, the bioinformatic analysis of clinical data found that high expressed PLK1 were closely associated with poor overall survival in HNSCC patients. Furthermore, PLK1 directly and indirectly modulated G2/M phase and metastasis (by regulated CTCF) in HNSCC cells, simultaneously. TBG significantly inhibited the protein levels of PLK1 in both phosphorylated and non-phosphorylated forms and then, in one way, inactivated PLK1 failed to activate G2/M phase-related proteins (including CDK1, CDC25c, and cyclin B1). In another way, be inhibited PLK1 unable promote the nuclear translocation of CTCF and thus suppressed HNSC cell metastasis. In contrast, the anti-proliferative and anti-metastasis effects of TBG on HNSCC cell were vanished when cells high-expressed PLK1.

CONCLUSION

The present study verified that PLK1 mediated TBG induced anti-tumor effect by modulated G2/M phase and metastasis in HNSCC cells.

A comprehensive review on anticancer evaluation techniques

The development of effective anticancer strategies and the improvement of our understanding of cancer need analytical tools. Utilizing a variety of analytical approaches while investigating anti-cancer medicines gives us a thorough understanding of the traits and mechanisms concerned to cancer cells, which enables us to develop potent treatments to combat them. The importance of anticancer research may be attributed to various analytical techniques that contributes to the identification of therapeutic targets and the assessment of medication efficacy, which are crucial things in expanding our understanding of cancer biology. The study looks at methods that are often used in cancer research, including cell viability assays, clonogenic assay, flow cytometry, 2D electrophoresis, microarray, immunofluorescence, western blot caspase activation assay, bioinformatics, etc. The fundamentals, applications, and how each technique analytical advances our understanding of cancer are briefly reviewed.

Effusanin B Inhibits Lung Cancer by Prompting Apoptosis and Inhibiting Angiogenesis

Cancer is one of the deadliest human diseases, causing high rates of illness and death. Lung cancer has the highest mortality rate among all malignancies worldwide. Effusanin B, a diterpenoid derived from Isodon serra, showed therapeutic potential in treating non-small-cell lung cancer (NSCLC). Further research on the mechanism indicated that effusanin B inhibited the proliferation and migration of A549 cells both in vivo and in vitro. The in vitro activity assay demonstrated that effusanin B exhibited significant anticancer activity. Effusanin B induced apoptosis, promoted cell cycle arrest, increased the production of reactive oxygen species (ROS), and altered the mitochondrial membrane potential (MMP). Based on mechanistic studies, effusanin B was found to inhibit the proliferation and migration of A549 cells by affecting the signal transducer and activator of transcription 3 (STAT3) and focal adhesion kinase (FAK) pathways. Moreover, effusanin B inhibited tumor growth and spread in a zebrafish xenograft model and demonstrated anti-angiogenic effects in a transgenic zebrafish model.

Application of the Nicoya OpenSPR to Studies of Biomolecular Binding: A Review of the Literature from 2016 to 2022

The Nicoya OpenSPR is a benchtop surface plasmon resonance (SPR) instrument. As with other optical biosensor instruments, it is suitable for the label-free interaction analysis of a diverse set of biomolecules, including proteins, peptides, antibodies, nucleic acids, lipids, viruses, and hormones/cytokines. Supported assays include affinity/kinetics characterization, concentration analysis, yes/no assessment of binding, competition studies, and epitope mapping. OpenSPR exploits localized SPR detection in a benchtop platform and can be connected with an autosampler (XT) to perform automated analysis over an extended time period. In this review article, we provide a comprehensive survey of the 200 peer-reviewed papers published between 2016 and 2022 that use the OpenSPR platform. We highlight the range of biomolecular analytes and interactions that have been investigated using the platform, provide an overview on the most common applications for the instrument, and point out some representative research that highlights the flexibility and utility of the instrument.

Bioactive natural products in COVID-19 therapy

The devastating COVID-19 pandemic has caused more than six million deaths worldwide during the last 2 years. Effective therapeutic agents are greatly needed, yet promising magic bullets still do not exist. Numerous natural products (cordycepin, gallinamide A, plitidepsin, telocinobufagin, and tylophorine) have been widely studied and play a potential function in treating COVID-19. In this paper, we reviewed published studies (from May 2021 to April 2022) relating closely to bioactive natural products (isolated from medicinal plants, animals products, and marine organisms) in COVID-19 therapy in vitro to provide some essential guidance for anti-SARS-CoV-2 drug research and development.