Expression of activated VEGFR2 by R1051Q mutation alters the energy metabolism of Sk-Mel-31 melanoma cells by increasing glutamine dependence

Therapeutic advances of targeting receptor tyrosine kinases in cancer

Receptor tyrosine kinases (RTKs), a category of transmembrane receptors, have gained significant clinical attention in oncology due to their central role in cancer pathogenesis. Genetic alterations, including mutations, amplifications, and overexpression of certain RTKs, are critical in creating environments conducive to tumor development. Following their discovery, extensive research has revealed how RTK dysregulation contributes to oncogenesis, with many cancer subtypes showing dependency on aberrant RTK signaling for their proliferation, survival and progression. These findings paved the way for targeted therapies that aim to inhibit crucial biological pathways in cancer. As a result, RTKs have emerged as primary targets in anticancer therapeutic development. Over the past two decades, this has led to the synthesis and clinical validation of numerous small molecule tyrosine kinase inhibitors (TKIs), now effectively utilized in treating various cancer types. In this manuscript we aim to provide a comprehensive understanding of the RTKs in the context of cancer. We explored the various alterations and overexpression of specific receptors across different malignancies, with special attention dedicated to the examination of current RTK inhibitors, highlighting their role as potential targeted therapies. By integrating the latest research findings and clinical evidence, we seek to elucidate the pivotal role of RTKs in cancer biology and the therapeutic efficacy of RTK inhibition with promising treatment outcomes.

Mutation in the Kinase Domain Alters the VEGFR2 Membrane Dynamics

BACKGROUND

Recently, the substitution R1051Q in VEGFR2 has been described as a cancer-associated "gain of function" mutation. VEGFR2R1051Q phosphorylation is ligand-independent and enhances the activation of intracellular pathways and cell growth both in vitro and in vivo. In cancer, this mutation is found in heterozygosity, suggesting that an interaction between VEGFR2R1051Q and VEGFR2WT may occur and could explain, at least in part, how VEGFR2R1051Q acts to promote VEGFR2 signaling. Despite this, the biochemical/biophysical mechanism of the activation of VEGFR2R1051Q remains poorly understood. On these bases, the aim of our study is to address how VEGFR2R1051Q influences the biophysical behavior (dimerization and membrane dynamics) of the co-expressed VEGFR2WT.

METHODS

We employed quantitative FLIM/FRET and FRAP imaging techniques using CHO cells co-transfected with the two forms of VEGFR2 to mimic heterozygosity.

RESULTS

Membrane protein biotinylation reveals that VEGFR2WT is more exposed on the cell membrane with respect to VEGFR2R1051Q. The imaging analyses show the ability of VEGFR2WT to form heterodimers with VEGFR2R1051Q and this interaction alters its membrane dynamics. Indeed, when the co-expression of VEGFR2WT/VEGFR2R1051Q occurs, VEGFR2WT shows reduced lateral motility and a minor pool of mobile fraction.

CONCLUSIONS

This study demonstrates that active VEGFR2R1051Q can affect the membrane behavior of the VEGFR2WT.

The pharmacology activities of Angelica keiskei Koidzumi and its efficacy and safety in humans

Chronic exposure to elevated levels of pro-oxidant factors may cause structural failings at the mitochondrial DNA level and alteration of antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase). Oxidative stress is an imbalance between the capacity of endogenous non-enzymatic antioxidants (glutathione, alpha-lipoic acid, uric acid, ferritin, metallothionein, melatonin, and bilirubin) and the occurrence of pro-oxidant factors which may lead to the pathogenesis of various diseases that affects the kidneys, pancreas, central nervous system, and cardiovascular system. Therefore, the utilization of medicinal plants with antioxidant activity, e.g., Angelica keiskei Koidzumi which contains chalcones, is interesting to be explored. Chalcones exhibit direct and indirect antioxidant activity and prevent oxidative stress by decreasing ROS, RNS, and superoxide production. In this review, we discuss the pharmacology activities of A. keiskei Koidzumi and its efficacy in humans. The articles were explored on PubMed and Google Scholar databases and based on the titles and abstracts related to the topic of interest, and 55 articles were selected. Two main chalcones of this plant, 4-hydroxyderricin and xanthoangelol, have been reported for their various pharmacology activities. The efficacy of A. keiskei was confirmed in anti-obesity, hepatoprotective, anti-diabetes mellitus, and increasing plasma antioxidants in patients with metabolic syndrome. A keiskei is safe as proven by only mild or no adverse events reported, thus it is prospective to be further developed as an antioxidant nutraceutical.

Anti-Oxidative and Anti-Aging Effects of Ethanol Extract of the Officinal Breynia (Breynia vitis-idaea) In Vitro

The skin is the largest organ of the human body, and it is also the one most exposed to external environmental contaminants. The skin is the body's first defense against harmful environmental stimuli, including ultraviolet B (UVB) rays and hazardous chemicals. Therefore, proper care of the skin is required to prevent skin-related diseases and age-related symptoms. In this study, we analyzed anti-aging and anti-oxidative effects of Breynia vitis-idaea ethanol extract (Bv-EE) in human keratinocytes and dermal fibroblasts. The Bv-EE had free radical scavenging activity and decreased the mRNA expression of MMPs and COX-2 in H₂O₂- or UVB-treated HaCaT cells. The Bv-EE also inhibited AP-1 transcriptional activity and phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase, and mitogen-activated protein kinase 14 (p38), which are major AP-1 activators upon H₂O₂ or UVB exposure. Furthermore, the promoter activity and mRNA expression of collagen type I (Col1A1) increased in HDF cells treated with Bv-EE, and Bv-EE recovered the collagen mRNA expression decreased by H₂O₂ or UVB exposure. These results suggest that Bv-EE has anti-oxidative effects by inhibiting the AP-1 signaling pathway, and shows anti-aging effects by upregulating collagen synthesis.

Anti-Melanogenesis Effects of a Cyclic Peptide Derived from Flaxseed via Inhibition of CREB Pathway

Linosorbs (Los) are cyclic peptides from flaxseed oil composed of the LO mixture (LOMIX). The activity of LO has been reported as being anti-cancer and anti-inflammatory. However, the study of skin protection has still not proceeded. In particular, there are poorly understood mechanisms of melanogenesis to LO. Therefore, we investigated the anti-melanogenesis effects of LOMIX and LO, and its activity was examined in mouse melanoma cell lines. The treatment of LOMIX (50 and 100 μg/mL) and LO (6.25-50 μM) suppressed melanin secretion and synthesis, which were 3-fold increased, in a dose-dependent manner, up to 95%. In particular, [1-9-NαC]-linusorb B3 (LO1) and [1-9-NαC]-linusorb B2 (LO2) treatment (12.5 and 25 μM) highly suppressed the synthesis of melanin in B16F10 cell lines up to 90%, without toxicity. LOMIX and LOs decreased the 2- or 3-fold increased mRNA levels, including the microphthalmia-associated transcription factor (MITF), Tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2) at the highest concentration (25 μM). Moreover, the treatment of 25 μM LO1 and LO2 inhibited the expression of MITF and phosphorylation of upper regulatory proteins such as CREB and PKA. Taken together, these results suggested that LOMIX and its individual LO could inhibit melanin synthesis via downregulating the CREB-dependent signaling pathways, and it could be used for novel therapeutic materials in hyperpigmentation.

Thymidine Kinase 1 Drives Skin Cutaneous Melanoma Malignant Progression and Metabolic Reprogramming

Background

Thymidine kinase 1 (TK1) is a cell cycle-dependent kinase that catalyzes the addition of a gamma-phosphate group to thymidine. The protumorigenic role of TK1 has been reported in various malignancies. However, the role of TK1 in skin cutaneous melanoma (SKCM) remains unclear. This study aimed to explore the molecular function of TK1 in SKCM progression.

Methods

Bioinformatics data were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Subcutaneous xenografts were established to observe the effect of TK1 knockdown on the proliferation of SKCM cells in vivo. RNA sequencing (RNA-seq; deposited in Sequence Read Archive, SRX10950283-SRX10950285 for A375 control cells and SRX10950286-SRX10950288 for TK1-silenced A375 cells) and immunoprecipitation–mass spectrometry (IP-MS) were used to analyze TK1-related genes and pathways. Seahorse XF Cell Mito tests and glycolysis stress assays were conducted for metabolic testing.

Results

TK1 was upregulated in malignant SKCM compared to that in normal tissues and cell lines. Elevated expression of TK1 was associated with poor prognosis. In vitro and in vivo assays demonstrated that TK1 promoted the proliferation and migration of SKCM cells. Moreover, TK1 was strongly associated with multiple intracellular metabolic pathways, facilitating cell mitochondrial respiration and glycolysis in SKCM malignant progression.

Conclusions

TK1 drives SKCM malignant progression and supports metabolic reprogramming, indicating that TK1 serves as a therapeutic target for SKCM.

Novel potential oncogenic and druggable mutations of FGFRs recur in the kinase domain across cancer types

Fibroblast growth factor receptors (FGFRs) are recurrently altered by single nucleotide variants (SNVs) in many human cancers. The prevalence of SNVs in FGFRs depends on the cancer type. In some tumors, such as the urothelial carcinoma, mutations of FGFRs occur at very high frequency (up to 60%). Many characterized mutations occur in the extracellular or transmembrane domains, while fewer known mutations are found in the kinase domain. In this study, we performed a bioinformatics analysis to identify novel putative cancer driver or therapeutically actionable mutations of the kinase domain of FGFRs. To pinpoint those mutations that may be clinically relevant, we exploited the recurrence of alterations on analogous amino acid residues within the kinase domain (PK_Tyr_Ser-Thr) of different kinases as a predictor of functional impact. By exploiting MutationAligner and LowMACA bioinformatics resources, we highlighted novel uncharacterized mutations of FGFRs which recur in other protein kinases. By revealing unanticipated correspondence with known variants, we were able to infer their functional effects, as alterations clustering on similar residues in analogous proteins have a high probability to elicit similar effects. As FGFRs represent an important class of oncogenes and drug targets, our study opens the way for further studies to validate their driver and/or actionable nature and, in the long term, for a more efficacious application of precision oncology.

Irisin regulates thermogenesis and lipolysis in 3T3-L1 adipocytes

BACKGROUND

Adipose tissue plays a pivotal role in the development and progression of the metabolic syndrome which along with its complications is an epidemic of the 21st century. Irisin is an adipo-myokine secreted mainly by skeletal muscle and targeting, among others, adipose tissue. In brown adipose tissue it upregulates uncoupling protein-1 (UCP1) which is responsible for mitochondrial non-shivering thermogenesis.

METHODS

Here we analyzed the effects of irisin on the metabolic activity of 3T3-L1 derived adipocytes through a mitochondrial flux assay. We also assessed the effects of irisin on the intracellular signaling through Western Blot. Finally, the gene expression of ucp1 and lipolytic genes was examined through RT-qPCR.

RESULTS

Irisin affects mitochondrial respiration and lipolysis in a time-dependent manner through the regulation of PI3K-AKT pathway. Irisin also induces the expression of UCP1 and the regulation of NF-κB, and CREB and ERK pathways.

CONCLUSION

Our data supports the role of irisin in the induction of non-shivering thermogenesis, the regulation of energy expenditure and lipolysis in adipocytes.

GENERAL SIGNIFICANCE

Irisin may be an attractive therapeutic target in the treatment of obesity and related metabolic disorders.

Apatinib triggers autophagic and apoptotic cell death via VEGFR2/STAT3/PD-L1 and ROS/Nrf2/p62 signaling in lung cancer

Background

Recently, a variety of clinical trials have shown that apatinib, a small-molecule anti-angiogenic drug, exerts promising inhibitory effects on multiple solid tumors, including non-small cell lung cancer (NSCLC). However, the underlying molecular mechanism of apatinib on NSCLC remains unclear.

Methods

MTT, EdU, AO/EB staining, TUNEL staining, flow cytometry, colony formation assays were performed to investigate the effects of apatinib on cell proliferation, cell cycle distribution, apoptosis and cancer stem like properties. Wound healing and transwell assays were conducted to explore the role of apatinib on migration and invasion. The regulation of apatinib on VEGFR2/STAT3/PD-L1 and ROS/Nrf2/p62 signaling were detected. Furthermore, we collected conditioned medium (CM) from A549 and H1299 cells to stimulate phorbol myristate acetate (PMA)-activated THP-1 cells, and examined the effect of apatinib on PD-L1 expression in macrophages. The Jurkat T cells and NSCLC cells co-culture model was used to assess the effect of apatinib on T cells activation. Subcutaneous tumor formation models were established to evaluate the effects of apatinib in vivo. Histochemical, immunohistochemical staining and ELISA assay were used to examine the levels of signaling molecules in tumors.

Results

We showed that apatinib inhibited cell proliferation and promoted apoptosis in NSCLC cells in vitro. Apatinib induced cell cycle arrest at G1 phase and suppressed the expression of Cyclin D1 and CDK4. Moreover, apatinib upregulated Cleaved Caspase 3, Cleaved Caspase 9 and Bax, and downregulated Bcl-2 in NSCLC cells. The colony formation ability and the number of CD133 positive cells were significantly decreased by apatinib, suggesting that apatinib inhibited the malignant and stem-like features of NSCLC cells. Mechanistically, apatinib inhibited PD-L1 and c-Myc expression by targeting VEGFR2/STAT3 signaling. Apatinib also inhibited PD-L1 expression in THP-1 derived macrophages stimulated by CM from NSCLC cells. Furthermore, apatinib pretreatment increased CD69 expression and IFN-γ secretion in stimulated Jurkat T cells co-cultured with NSCLC cells. Apatinib also promoted ROS production and inhibited Nrf2 and p62 expression, leading to the autophagic and apoptotic cell death in NSCLC. Moreover, apatinib significantly inhibited tumor growth in vivo.

Conclusion

Our data indicated that apatinib induced autophagy and apoptosis in NSCLC via regulating VEGFR2/STAT3/PD-L1 and ROS/Nrf2/p62 signaling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02069-4.

Apatinib suppressed proliferation, induced cell cycle arrest and apoptosis, and inhibited malignancy in NSCLC in vitro and in vivo.

Apatinib downregulated PD-L1 and c-Myc in NSCLC through VEGFR2/STAT3 pathway.

Apatinib inhibited PD-L1 expression in THP-1 derived macrophages stimulated by the conditioned medium from NSCLC cells and partially restored the activation of Jurkat T cells co-cultured with NSCLC cells.

Apatinib induced ROS generation and inhibited Nrf2 and p62 expression, leading to the autophagic and apoptotic cell death in NSCLC.

Protein domain-based approaches for the identification and prioritization of therapeutically actionable cancer variants

The tremendous number of cancer variants that can be detected by NGS analyses has required the development of computational approaches to prioritize mutations on the basis of their biological and clinical significance. Standard strategies take a gene-centric approach to the problem, allowing exclusively the identification of highly frequent variants. On the contrary, protein domain (PD)-based approaches allow to identify functionally relevant low frequency variants by searching for mutations that recur on analogous residues across homologous proteins (i.e. containing the same PD). Such approaches enable to transfer information about the effects and druggability from one known mutation to unknown ones. Here we describe how PD-based strategies work, and discuss how they could be exploited for mutation prioritization. The principle that mutations clustered on specific residues of PDs have the same functional consequences and are therapeutically actionable in a similar manner could help the choice of patient-specific targeted drugs, eventually improving the management of cancer patients.