Bone morphogenetic protein signaling regulation of AMPK and PI3K in lung cancer cells and C. elegans

AMPK: an energy sensor for Non-small cell lung cancer progression and treatment

Lung cancer (LC) is the leading cause of cancer-related morbidity and mortality in China, with non-small cell lung cancer (NSCLC) accounting for 85% of the overall lung cancer cases. AMP-activated protein kinase (AMPK) is a key regulator of energy balance and homeostasis, and its dysregulation is a common feature in various malignancies, particularly in NSCLC with mutations in Liver kinase B1 (LKB1). Studies have shown that the AMPK signalling pathway has a dual role in NSCLC progression, both inhibiting and promoting the progression of malignant tumours. Therefore, drugs targeting the AMPK signalling pathway may hold significant promise for therapeutic application in NSCLC. This review aims to examine the manifestations and mechanisms by which AMPK and its associated signalling molecules influence NSCLC progression and treatment. Firstly, we discuss the critical importance of AMPK within the mutational context of NSCLC. Secondly, We summarise the drugs and related substances that modulate the AMPK signalling pathway in NSCLC and evaluate the evidence from preclinical studies on combination AMPK-targeted therapies to address the issue of drug resistance in NSCLC under current clinical treatments. In summary, this paper highlights the critical importance of developing AMPK-targeted drugs to enhance therapeutic efficacy in NSCLC, as well as the potential for applying these drugs in clinical therapy to overcome drug resistance.

HOXD1 inhibits lung adenocarcinoma progression and is regulated by DNA methylation

The homeobox (HOX) gene family encodes a number of highly conserved transcription factors and serves a crucial role in embryonic development and tumorigenesis. Homeobox D1 (HOXD1) is a member of the HOX family, whose biological functions in lung cancer are currently unclear. The University of Alabama at Birmingham Cancer data analysis Portal of HOXD1 expression patterns demonstrated that HOXD1 was downregulated in lung adenocarcinoma (LUAD) patient samples compared with adjacent normal tissue. Western blotting analysis demonstrated low HOXD1 protein expression levels in lung LUAD cell lines. The Kaplan‑Meier plotter database demonstrated that reduced HOXD1 expression levels in LUAD correlated with poorer overall survival. Meanwhile, an in vitro study showed that HOXD1 overexpression suppressed LUAD cell proliferation, migration and invasion. In a mouse tumor model, upregulated HOXD1 was demonstrated to inhibit tumor growth. In addition, targeted bisulfite sequencing and chromatin immunoprecipitation assays demonstrated that DNA hypermethylation occurred in the promoter region of the HOXD1 gene and was associated with the action of DNA methyltransferases. Moreover, upregulated HOXD1 served as a transcriptional factor and increased the transcriptional expression of bone morphogenic protein (BMP)2 and BMP6. Taken together, the dysregulation of HOXD1 mediated by DNA methylation inhibited the initiation and progression of LUAD by regulating the expression of BMP2/BMP6.

BMP receptor 2 inhibition regulates mitochondrial bioenergetics to induce synergistic cell death with BCL-2 inhibitors in leukemia and NSLC cells

Background

Bone morphogenetic protein (BMP) signaling cascade is a phylogenetically conserved stem cell regulator that is aberrantly expressed in non-small cell lung cancer (NSLC) and leukemias. BMP signaling negatively regulates mitochondrial bioenergetics in lung cancer cells. The impact of inhibiting BMP signaling on mitochondrial bioenergetics and the effect this has on the survival of NSLC and leukemia cells are not known.

Methods

Utilizing the BMP type 2 receptor (BMPR2) JL189, BMPR2 knockout (KO) in cancer cells, and BMP loss of function mutants in C elegans, we determined the effects of BMPR2 inhibition (BMPR2i) on TCA cycle metabolic intermediates, mitochondrial respiration, and the regulation of mitochondrial superoxide anion (SOA) and Ca++ levels. We also examined whether BMPR2i altered the threshold cancer therapeutics induce cell death in NSLC and leukemia cell lines. KO of the mitochondria uniporter (MCU) was used to determine the mechanism BMPR2i regulates the uptake of Ca++ into the mitochondria, mitochondrial bioenergetics, and cell death.

Results

BMPR2i increases mtCa++ levels and enhances mitochondrial bioenergetics in both NSLC and leukemia cell lines that is conserved in C elegans. BMPR2i induced increase in mtCa++ levels is regulated through the MCU, effecting mitochondria mass and cell survival. BMPR2i synergistically induced cell death when combined with BCL-2 inhibitors or microtubule targeting agents in both NSLC and leukemia cells. Cell death is caused by synergistic increase in mitochondrial ROS and Ca++ levels. BMPR2i enhances Ca++ uptake into the mitochondria induced by reactive oxygen species (ROS) produced by cancer therapeutics. Both acute myeloid leukemia (AML) and T-cell lymphoblastic leukemia cells lines were more responsive to the JL189 alone and when combined with venetoclax or navitoclax compared to NSLC.

Bone morphogenetic protein 4 inhibits rat stem/progenitor Leydig cell development and regeneration via SMAD-dependent and SMAD-independent signaling

Bone morphogenetic protein 4 (BMP4) is an important member of the transforming growth factor-β superfamily. BMP4 is expressed in the Leydig cell lineage. We hypothesized that BMP4 might regulate the development of stem/progenitor Leydig cells. The BMP4 receptors, BMPR1A, BMPR1B, and BMPR2 were found to be expressed in progenitor Leydig cells of prepubertal testis and isolated cells. BMP4 at 1 and 10 ng/mL significantly reduced androgen production and down-regulated steroidogenesis-related gene and protein expression possibly by activating the SMAD signaling pathway (increasing SMAD1/5 phosphorylation and SMAD4) at 24 h treatment. BMP4 at 0.1 ng/mL and higher concentrations markedly reduced the EdU labeling index of CD90⁺ stem Leydig cells after 24 h treatment and significantly reduced the number of EdU⁺ stem Leydig cells on the surface of seminiferous tubules after 7 days of culture. BMP4 at 0.01 ng/mL and higher concentrations significantly blocked the differentiation of stem Leydig cells into adult cells, as shown by the reduction of testosterone secretion and the downregulation of Lhcgr, Scarb1, Cyp11a1, Hsd11b1, and Insl3 and their function after 3D seminiferous tubule culture for 3 weeks, and this effect was reversed by co-treatment with the BMP4 antagonists noggin and doxomorphine. In addition, BMP4 also blocked stem Leydig cell differentiation through SMAD-independent signaling pathways (ERK1/2 and AMPK). Ethanedimethane sulfonate (EDS) single injection can result in reduction of testosterone, restoration can happen post treatment. In an in vivo model of Leydig cell regeneration following EDS treatment, intratesticular injection of BMP4 from day 14 to day 28 post-elimination significantly reduced serum testosterone levels and down-regulated the expression of Scarb1, Star, Hsd11b1, and Insl3 and its proteins, possibly through SMAD-dependent and SMAD-independent (ERK1/2 and AMPK) signaling pathways. In conclusion, BMP4 is expressed in cells of the Leydig cell lineage and blocks entry of stem/progenitor Leydig cells into adult Leydig cells through SMAD-dependent and SMAD-independent signaling pathways.

Curcumin and Its Analogs in Non-Small Cell Lung Cancer Treatment: Challenges and Expectations

Researchers have made crucial advances in understanding the pathogenesis and therapeutics of non-small cell lung cancer (NSCLC), improving our understanding of lung tumor biology and progression. Although the survival of NSCLC patients has improved due to chemoradiotherapy, targeted therapy, and immunotherapy, overall NSCLC recovery and survival rates remain low. Thus, there is an urgent need for the continued development of novel NSCLC drugs or combination therapies with less toxicity. Although the anticancer effectiveness of curcumin (Cur) and some Cur analogs has been reported in many studies, the results of clinical trials have been inconsistent. Therefore, in this review, we collected the latest related reports about the anti-NSCLC mechanisms of Cur, its analogs, and Cur in combination with other chemotherapeutic agents via the Pubmed database (accessed on 18 June 2022). Furthermore, we speculated on the interplay of Cur and various molecular targets relevant to NSCLC with discovery studio and collected clinical trials of Cur against NSCLC to clarify the role of Cur and its analogs in NSCLC treatment. Despite their challenges, Cur/Cur analogs may serve as promising therapeutic agents or adjuvants for lung carcinoma treatment.

Ym155 localizes to the mitochondria leading to mitochondria dysfunction and activation of AMPK that inhibits BMP signaling in lung cancer cells

The imidazolium compound Ym155 was first reported to be a survivin inhibitor. Ym155 potently induces cell death of many types of cancer cells in preclinical studies. However, in phase II clinical trials Ym155 failed to demonstrate a significant benefit. Studies have suggested that the cytotoxic effects of Ym155 in cancer cells are not mediated by the inhibition of survivin. Understanding the mechanism by which Ym155 induces cell death would provide important insight how to improve its efficacy as a cancer therapeutic. We demonstrate a novel mechanism by which Ym155 induces cell death by localizing to the mitochondria causing mitochondrial dysfunction. Our studies suggest that Ym155 binds mitochondrial DNA leading to a decrease in oxidative phosphorylation, decrease in TCA cycle intermediates, and an increase in mitochondrial permeability. Furthermore, we show that mitochondrial stress induced by Ym155 and other mitochondrial inhibitors activates AMP-activated kinase leading to the downregulation to bone morphogenetic protein (BMP) signaling. We provide first evidence that Ym155 initiates cell death by disrupting mitochondrial function.