Akt/mTOR and AMPK signaling pathways are responsible for liver X receptor agonist GW3965-enhanced gefitinib sensitivity in non-small cell lung cancer cell lines

Deoxybouvardin targets EGFR, MET, and AKT signaling to suppress non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) remains a significant challenge, as it is one of the leading causes of cancer-related deaths, and the development of resistance to anticancer therapy makes it difficult to treat. In this study, we investigated the anticancer mechanism of deoxybouvardin (DB), a cyclic hexapeptide, in gefitinib (GEF)-sensitive and -resistant NSCLC HCC827 cells. DB inhibited the viability and growth of HCC827 cells in a concentration- and time-dependent manner. In vitro kinase assay showed DB inhibited epidermal growth factor receptor (EGFR), mesenchymal-epithelial transition (MET), and AKT, and their phosphorylation was suppressed in HCC827 cells treated with DB. A molecular docking model suggested that DB interacts with these kinases in the ATP-binding pockets. DB induces ROS generation and cell cycle arrest. DB treatment of HCC827 cells leads to mitochondrial membrane depolarization. The induction of apoptosis through caspase activation was confirmed by Z-VAD-FMK treatment. Taken together, DB inhibited the growth of both GEF-sensitive and GEF-resistant NSCLC cells by targeting EGFR, MET, and AKT and inducing ROS generation and caspase activation. Further studies on DB can improve the treatment of chemotherapy-resistant NSCLC through the development of effective DB-based anticancer agents.

Dynamics simulation and in vitro studies of betulinic acid derivative with liver X receptor

Molecular dynamics simulation of the dominant conformational conjugate was performed for 40 ns and 100 ns via Amber software based on molecular docking by Sybyl software. Because the RMSD and RMSF of 100 ns MD simulation were higher than that of 40 ns MD simulation, the 40 ns was reasonable and credible for MD simulation. The binding free energy and decomposition free energy of the two systems of betulinic acid, com3 with liver X receptor was calculated by the MM_GBSA and MM_PBSA methods, respectively. The results showed that the two systems reached equilibrium and convergence at 20 ns, both stable at about 2 Å, and exhibited low volatility in the range of amino acid 270 to 370 (RMSF <1 Å). The binding energy of com3 (ΔGbind = -68.02 kcal/mol by the MM_GBSA method or -55.50 kcal/mol by the MM_PBSA method) with the liver X receptor was lower than that of betulinic acid (ΔGbind = -55.70 kcal/mol or -42.73 kcal/mol) respectively, and van der Waals force was the most important main driving force, which was consistent with molecular docking and previous experiments. Hydrophobic groups and aromatic rings can be introduced appropriately in structure optimization to increase the van der Waals force and π-π accumulation effect of betulinic acid and liver X receptor, which is conducive to binding and thereby increasing antitumor activity. The clone formation assay and results of western blotting indicated that BA derivative com3 exposure inhibited cell proliferation may relate to the regulation of the AKT/mTOR pathway in 7721 cells. This study clarifies the dynamic interaction mode and potential mechanism of betulinic acid and its derivatives with the liver X receptor, which provides a new idea for the rapid screening of liver X receptor agonists from traditional Chinese medicines.Communicated by Ramaswamy H. Sarma.

Preclinical evidence using synthetic compounds and natural products indicates that AMPK represents a potential pharmacological target for the therapy of pulmonary diseases

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a highly conserved eukaryotic enzyme discovered as a key regulator of cellular energy homeostasis, with anti-inflammation, antioxidative stress, anticancer, and antifibrosis beneficial effects. AMPK is dysregulated in human pulmonary diseases such as acute lung injury, nonsmall cell lung cancer, pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. This review provides an overview of the beneficial role of natural, synthetic, and Chinese traditional medicines AMPK modulators in pulmonary diseases, and highlights the role of the AMPK signaling pathway in the lung, emphasizing the importance of finding lead compounds and drugs that can target and modulate AMPK to treat the lung diseases.

Targeted Inhibitors of EGFR: Structure, Biology, Biomarkers, and Clinical Applications

Members of the EGFR family of tyrosine kinase receptors are major regulators of cellular proliferation, differentiation, and survival. In humans, abnormal activation of EGFR is associated with the development and progression of many cancer types, which makes it an attractive target for molecular-guided therapy. Two classes of EGFR-targeted cancer therapeutics include monoclonal antibodies (mAbs), which bind to the extracellular domain of EGFR, and tyrosine kinase inhibitors (TKIs), which mostly target the intracellular part of EGFR and inhibit its activity in molecular signaling. While EGFR-specific mAbs and three generations of TKIs have demonstrated clinical efficacy in various settings, molecular evolution of tumors leads to apparent and sometimes inevitable resistance to current therapeutics, which highlights the need for deeper research in this field. Here, we tried to provide a comprehensive and systematic overview of the rationale, molecular mechanisms, and clinical significance of the current EGFR-targeting drugs, highlighting potential candidate molecules in development. We summarized the underlying mechanisms of resistance and available personalized predictive approaches that may lead to improved efficacy of EGFR-targeted therapies. We also discuss recent developments and the use of specific therapeutic strategies, such as multi-targeting agents and combination therapies, for overcoming cancer resistance to EGFR-specific drugs.

Role of AMPK/mTOR, mitochondria, and ROS in the pathogenesis of endometriosis

Endometriosis is the presence of endometrial tissue outside the uterine cavity usually in the ovaries, fallopian tube, and pelvic cavity. It's a chronic enigmatic gynecological condition associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, and oxidative stress. This environment promotes cell survival through the binding of membrane receptors and subsequent cascading activation of intracellular kinases that stimulate a cellular response. In endometriosis, well-established signaling pathways, mTOR and AMPK, are altered via steroid hormones and other factors to promote cell growth, migration, and proliferation. This is accompanied by dysfunction in the mitochondria that increase energy production to sustain proliferation demands consequently leading to reactive oxygen species overproduction. This review aims to summarize the role of altered mTOR/AMPK signaling pathway, mitochondrial dysfunction, and reactive oxygen species overproduction along with providing therapeutic and diagnostic approaches. Highlighting these factors would provide a better understanding to reach a coherent theory for the pathogenesis of endometriosis.

Cholesterol Metabolic Reprogramming in Cancer and Its Pharmacological Modulation as Therapeutic Strategy

Cholesterol is a ubiquitous sterol with many biological functions, which are crucial for proper cellular signaling and physiology. Indeed, cholesterol is essential in maintaining membrane physical properties, while its metabolism is involved in bile acid production and steroid hormone biosynthesis. Additionally, isoprenoids metabolites of the mevalonate pathway support protein-prenylation and dolichol, ubiquinone and the heme a biosynthesis. Cancer cells rely on cholesterol to satisfy their increased nutrient demands and to support their uncontrolled growth, thus promoting tumor development and progression. Indeed, transformed cells reprogram cholesterol metabolism either by increasing its uptake and de novo biosynthesis, or deregulating the efflux. Alternatively, tumor can efficiently accumulate cholesterol into lipid droplets and deeply modify the activity of key cholesterol homeostasis regulators. In light of these considerations, altered pathways of cholesterol metabolism might represent intriguing pharmacological targets for the development of exploitable strategies in the context of cancer therapy. Thus, this work aims to discuss the emerging evidence of in vitro and in vivo studies, as well as clinical trials, on the role of cholesterol pathways in the treatment of cancer, starting from already available cholesterol-lowering drugs (statins or fibrates), and moving towards novel potential pharmacological inhibitors or selective target modulators.

Plantamajoside modulates the proliferation, stemness, and apoptosis of lung carcinoma via restraining p38MAPK and AKT phosphorylation

BACKGROUND

Plantamajoside (PMS), an active anti-inflammatory component and antioxidant derived from Herba Plantaginis, has been reported to exert a suppressive effect in liver cancer in vivo. In this study, we tested the effects of PMS on the metastatic 95D cell line.

METHODS

95D cells were characterized as most sensitive to PMS across several lung cancer cell lines. Cell viability within 24 h was tested with CCK-8. Different concentrations of PMS (0, 50, 100, and 200 µg/mL) and 5 µg/mL of cisplatin were established for later 24 h treatment. Relative mRNA and protein expression were assessed with PCR and Western blotting. Cell proliferation and stemness were indicated with colony and sphere formation. Cell metastasis was evaluated with wound healing and Transwell. Apoptotic cells and mitochondrial membrane potential were investigated with flow cytometry.

RESULTS

CCK-8 assay showed PMS to inhibit the viability of 95D cells in a dose-dependent manner. PMS decreased colony formation and inhibited stemness in 95D cells. Invasion and migration were also inhibited. Moreover, PMS induced cell apoptosis, and decreased mitochondrial membrane potential. All of these effects were dose dependent. Interestingly, PMS treatment reduced the protein expression of p-p38 MAPK and p-AKT but not that of p38 MAPK and AKT.

CONCLUSIONS

PMS inhibited proliferation, stemness, and migration, and initiated apoptosis in 95D cells, possibly through p38 MAPK and AKT dephosphorylation and mitochondria dysfunction. These findings support the promise of PMS as a prodrug in lung cancer treatment.