Convergence of G protein-coupled receptor and S-nitrosylation signaling determines the outcome to cardiac ischemic injury

Protein modifications in hepatic ischemia-reperfusion injury: molecular mechanisms and targeted therapy

Ischemia-reperfusion injury refers to the damage that occurs when blood supply is restored to organs or tissues after a period of ischemia. This phenomenon is commonly observed in clinical contexts such as organ transplantation and cardiac arrest resuscitation. Among these, hepatic ischemia-reperfusion injury is a prevalent complication in liver transplantation, significantly impacting the functional recovery of the transplanted liver and potentially leading to primary graft dysfunction. With the growing demand for organ transplants and the limited availability of donor organs, effectively addressing hepatic ischemia-reperfusion injury is essential for enhancing transplantation success rates, minimizing complications, and improving graft survival. The pathogenesis of hepatic ischemia-reperfusion injury is multifaceted, involving factors such as oxidative stress and inflammatory responses. This article focuses on the role of protein post-translational modifications in hepatic ischemia-reperfusion injury, including phosphorylation, ubiquitination, acetylation, ADP-ribosylation, SUMOylation, crotonylation, palmitoylation, and S-nitrosylation. Initially, we examined the historical discovery of these protein post-translational modifications and subsequently investigated their impact on cellular signal transduction, enzymatic activity, protein stability, and protein-protein interactions. The emphasis of this study is on the pivotal role of protein post-translational modifications in the progression of hepatic ischemia-reperfusion injury and their potential as therapeutic targets. This study aims to conduct a comprehensive analysis of recent advancements in research on protein modifications in hepatic ischemia-reperfusion injury, investigate the underlying molecular mechanisms, and explore future research trajectories. Additionally, future research directions are proposed, including the exploration of interactions between various protein modifications, the identification of specific modification sites, and the development of drugs targeting these modifications. These efforts aim to deepen our understanding of protein post-translational modifications in hepatic ischemia-reperfusion injury and pave the way for innovative therapeutic interventions.

IRS2 Signaling Protects Against Stress-Induced Arrhythmia by Maintaining Ca2+ Homeostasis

BACKGROUND

The docking protein IRS2 (insulin receptor substrate protein-2) is an important mediator of insulin signaling and may also regulate other signaling pathways. Murine hearts with cardiomyocyte-restricted deletion of Irs2 (cIRS2-KO) are more susceptible to pressure overload-induced cardiac dysfunction, implying a critical protective role of IRS2 in cardiac adaptation to stress through mechanisms that are not fully understood. There is limited evidence regarding the function of IRS2 beyond metabolic homeostasis regulation, particularly in the context of cardiac disease.

METHODS

A retrospective analysis of an electronic medical record database was conducted to identify patients with IRS2 variants and assess their risk of cardiac arrhythmias. Arrhythmia susceptibility was examined in cIRS2-KO mice. The underlying mechanisms were investigated using confocal calcium imaging of ex vivo whole hearts and isolated cardiomyocytes to assess calcium handling, Western blotting to analyze the involved signaling pathways, and pharmacological and genetic interventions to rescue arrhythmias in cIRS2-KO mice.

RESULTS

The retrospective analysis identified patients with IRS2 variants of uncertain significance with a potential association to an increased risk of cardiac arrhythmias compared with matched controls. cIRS2-KO hearts were found to be prone to catecholamine-sensitive ventricular tachycardia and reperfusion ventricular tachycardia. Confocal calcium imaging of ex vivo whole hearts and single isolated cardiomyocytes from cIRS2-KO hearts revealed decreased Ca²⁺ transient amplitudes, increased spontaneous Ca²⁺ sparks, and reduced sarcoplasmic reticulum Ca²⁺ content during sympathetic stress, indicating sarcoplasmic reticulum dysfunction. We identified that overactivation of the AKT1/NOS3 (nitric oxide synthase 3)/CaMKII (Ca²⁺/calmodulin-dependent protein kinase II)/RyR2 (type 2 ryanodine receptor) signaling pathway led to calcium mishandling and catecholamine-sensitive ventricular tachycardia in cIRS2-KO hearts. Pharmacological AKT inhibition or genetic stabilization of RyR2 rescued catecholamine-sensitive ventricular tachycardia in cIRS2-KO mice.

CONCLUSIONS

Cardiac IRS2 inhibits sympathetic stress-induced AKT/NOS3/CaMKII/RyR2 overactivation and calcium-dependent arrhythmogenesis. This novel IRS2 signaling axis, essential for maintaining cardiac calcium homeostasis under stress, presents a promising target for developing new antiarrhythmic therapies.

Peroxynitrite-Free Nitric Oxide-Embedded Nanoparticles Maintain Nitric Oxide Homeostasis for Effective Revascularization of Myocardial Infarcts

Revascularization is crucial for treating myocardial infarction (MI). Nitric oxide (NO), at an appropriate concentration, is recognized as an ideal and potent pro-angiogenic factor. However, the application of NO in the treatment of MI is limited. Improper NO supplementation is harmful to revascularization because NO is converted into harmful peroxynitrite (ONOO-) in MI tissues with high reactive oxygen species (ROS) levels. We overcome these obstacles by embedding biliverdin and NO into Prussian blue (PB) nanolattices to obtain an ONOO--free NO-embedded nanomedicine (OFEN). Unlike previous NO donors, OFEN provides NO stably and spontaneously for a longer time (>7 days), which makes it possible to maintain a stable concentration of NO, suitable for angiogenesis, through dose optimization. More importantly, based on the synergy between PB and biliverdin, OFEN converts ROS into beneficial O2 and inhibits the production of ONOO- from the source. OFEN specifically targets MI tissues and achieves sustained and stable NO delivery at the MI site. OFEN effectively promotes revascularization in the MI tissue, significantly reduces myocardial death and fibrosis, and ultimately promotes the complete recovery of cardiac function. Our strategy provides a promising approach for the treatment of myocardial and other ischemic diseases.

Impact of HDAC6-mediated progesterone receptor expression on the response of breast cancer cells to hormonal therapy

Modulation of estrogen receptor (ER) and progesterone receptor (PR) expression, as well as their emerging functional crosstalk, remains a potential approach for enhancing the response to hormonal therapy in breast cancer. Aberrant epigenetic alterations induced by histone deacetylases (HDACs) were massively implicated in dysregulating the function of hormone receptors in breast cancer. Although much is known about the regulation of ER signaling by HDAC, the precise role of HDAC in modulating the expression of PR and its impact on the outcomes of hormonal therapy is poorly defined. Here, we demonstrate the involvement of HDAC6 in regulating PR expression in breast cancer cells. The correlation between HDAC6 and hormone receptors was investigated in patients' tissues by immunohistochemistry (n = 80) and publicly available data (n = 3260) from breast cancer patients. We explored the effect of modulating the expression of HDAC6 as well as its catalytic inhibition on the level of hormone receptors by a variety of molecular analyses, including Western blot, immunofluorescence, Real-time PCR, RNA-seq analysis and chromatin immunoprecipitation. Based on our in-silico and immunohistochemistry analyses, HDAC6 levels were negatively correlated with PR status in breast cancer tissues. The downregulation of HDAC6 enhanced the expression of PR-B in hormone receptor-positive and triple-negative breast cancer (TNBC) cells. The selective targeting of HDAC6 by tubacin resulted in the enrichment of the H3K9 acetylation mark at the PGR-B gene promoter region and enhanced the expression of PR-B. Additionally, transcriptomic analysis of tubacin-treated cells revealed enhanced activity of acetyltransferase and growth factor signaling pathways, along with the enrichment of transcription factors involved in the transcriptional activity of ER, underscoring the crucial role of HDAC6 in regulating hormone receptors. Notably, the addition of HDAC6 inhibitor potentiated the effects of anti-ER and anti-PR drugs mainly in TNBC cells. Together, these data highlight the role of HDAC6 in regulating PR expression and provide a promising therapeutic approach for boosting breast cancer sensitivity to hormonal therapy.

Unveiling FRG1's DNA repair role in breast cancer

The FRG1(FSHD region gene 1) gene has emerged as a pivotal tumor suppressor in both breast and prostate cancer. HPF1 (Histone PARylation Factor 1), a gene crucial in the base excision repair (BER) mechanism for single-stranded DNA (ssDNA) lesions, showcases a robust correlation with FRG1. This implies that FRG1 might have the capacity to influence BER via HPF1, potentially playing a role in tumorigenesis. Using a comprehensive approach that integrates in-silico analyses involving differential gene expression, KEGG (Kyoto Encyclopedia of Genes and Genomes), GO (Gene Ontology), and STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) databases, we unravelled the intricate network of genes and pathways influenced by FRG1, which includes BER. Our linear regression analysis unveiled a positive relationship between FRG1 and key genes crucial for BER. Notably, breast cancer patients with low FRG1 expression exhibited a significantly higher frequency of mutation in TP53. To enhance the accuracy of our analysis, we conducted qRT-PCR assays, which demonstrated that FRG1 affects the transcription of DNA base excision repair genes, showing differential expression in breast cancer cells. Moreover, through the Alkaline Comet Assay, a technique that quantifies DNA damage at the single-cell level, we observed diminished DNA repair capabilities when FRG1 levels are low. Risk scores were calculated using the Cox regression coefficients, and we found notable differences in Overall Survival (OS) and mRNA expression of DEGs in the low and high-risk groups. In summary, our findings shed light on the pivotal role of FRG1 in maintaining DNA repair efficiency within breast cancer cells.

Role of G protein-coupled receptor kinases (GRKs) in β2 -adrenoceptor-mediated glucose uptake

Truncation of the C-terminal tail of the β2 -AR, transfection of βARKct or over-expression of a kinase-dead GRK mutant reduces isoprenaline-stimulated glucose uptake, indicating that GRK is important for this response. We explored whether phosphorylation of the β2 -AR by GRK2 has a role in glucose uptake or if this response is related to the role of GRK2 as a scaffolding protein. CHO-GLUT4myc cells expressing wild-type and mutant β2 -ARs were generated and receptor affinity for [3 H]-CGP12177A and density of binding sites determined together with the affinity of isoprenaline and BRL37344. Following receptor activation by β2 -AR agonists, cAMP accumulation, GLUT4 translocation, [3 H]-2-deoxyglucose uptake, and β2 -AR internalization were measured. Bioluminescence resonance energy transfer was used to investigate interactions between β2 -AR and β-arrestin2 or between β2 -AR and GRK2. Glucose uptake after siRNA knockdown or GRK inhibitors was measured in response to β2 -AR agonists. BRL37344 was a poor partial agonist for cAMP generation but displayed similar potency and efficacy to isoprenaline for glucose uptake and GLUT4 translocation. These responses to β2 -AR agonists occurred in CHO-GLUT4myc cells expressing β2 -ARs lacking GRK or GRK/PKA phosphorylation sites as well as in cells expressing the wild-type β2 -AR. However, β2 -ARs lacking phosphorylation sites failed to recruit β-arrestin2 and did not internalize. GRK2 knock-down or GRK2 inhibitors decreased isoprenaline-stimulated glucose uptake in rat L6 skeletal muscle cells. Thus, GRK phosphorylation of the β2 -AR is not associated with isoprenaline- or BRL37344-stimulated glucose uptake. However, GRKs acting as scaffold proteins are important for glucose uptake as GRK2 knock-down or GRK2 inhibition reduces isoprenaline-stimulated glucose uptake.

Aspartoacylase suppresses prostate cancer progression by blocking LYN activation

BACKGROUND

Globally, despite prostate cancer (PCa) representing second most prevalent malignancy in male, the precise molecular mechanisms implicated in its pathogenesis remain unclear. Consequently, elucidating the key molecular regulators that govern disease progression could substantially contribute to the establishment of novel therapeutic strategies, ultimately advancing the management of PCa.

METHODS

A total of 49 PCa tissues and 43 adjacent normal tissues were collected from January 2017 to December 2021 at Zhongnan Hospital of Wuhan University. The advanced transcriptomic methodologies were employed to identify differentially expressed mRNAs in PCa. The expression of aspartoacylase (ASPA) in PCa was thoroughly evaluated using quantitative real-time PCR and Western blotting techniques. To elucidate the inhibitory role of ASPA in PCa cell proliferation and metastasis, a comprehensive set of in vitro and in vivo assays were conducted, including orthotopic and tumor-bearing mouse models (n = 8 for each group). A combination of experimental approaches, such as Western blotting, luciferase assays, immunoprecipitation assays, mass spectrometry, glutathione S-transferase pull-down experiments, and rescue studies, were employed to investigate the underlying molecular mechanisms of ASPA's action in PCa. The Student's t-test was employed to assess the statistical significance between two distinct groups, while one-way analysis of variance was utilized for comparisons involving more than two groups. A two-sided P value of less than 0.05 was deemed to indicate statistical significance.

RESULTS

ASPA was identified as a novel inhibitor of PCa progression. The expression of ASPA was found to be significantly down-regulated in PCa tissue samples, and its decreased expression was independently associated with patients' prognosis (HR = 0.60, 95% CI 0.40-0.92, P = 0.018). Our experiments demonstrated that modulation of ASPA activity, either through gain- or loss-of-function, led to the suppression or enhancement of PCa cell proliferation, migration, and invasion, respectively. The inhibitory role of ASPA in PCa was further confirmed using orthotopic and tumor-bearing mouse models. Mechanistically, ASPA was shown to directly interact with the LYN and inhibit the phosphorylation of LYN as well as its downstream targets, JNK1/2 and C-Jun, in both PCa cells and mouse models, in an enzyme-independent manner. Importantly, the inhibition of LYN activation by bafetinib abrogated the promoting effect of ASPA knockdown on PCa progression in both in vitro and in vivo models. Moreover, we observed an inverse relationship between ASPA expression and LYN activity in clinical PCa samples, suggesting a potential regulatory role of ASPA in modulating LYN signaling.

CONCLUSION

Our findings provide novel insights into the tumor-suppressive function of ASPA in PCa and highlight its potential as a prognostic biomarker and therapeutic target for the management of this malignancy.

Twist alters the breast tumor microenvironment via choline kinase to facilitate an aggressive phenotype

Twist (TWIST1) is a gene required for cell fate specification in embryos and its expression in mammary epithelium can initiate tumorigenesis through the epithelial-mesenchymal transition. To identify downstream target genes of Twist in breast cancer, we performed microarray analysis on the transgenic breast cancer cell line, MCF-7/Twist. One of the targets identified was choline kinase whose upregulation resulted in increased cellular phosphocholine and total choline containing compounds-a characteristic observed in highly aggressive metastatic cancers. To study the interactions between Twist, choline kinase, and their effect on the microenvironment, we used 1H magnetic resonance spectroscopy and found significantly higher phosphocholine and total choline, as well as increased phosphocholine/glycerophosphocholine ratio in MCF-7/Twist cells. We also observed significant increases in extracellular glucose, lactate, and [H +] ion concentrations in the MCF-7/Twist cells. Magnetic resonance imaging of MCF-7/Twist orthotopic breast tumors showed a significant increase in vascular volume and permeability surface area product compared to control tumors. In addition, by reverse transcription-quantitative polymerase chain reaction, we discovered that Twist upregulated choline kinase expression in estrogen receptor negative breast cancer cell lines through FOXA1 downregulation. Moreover, using The Cancer Genome Atlas database, we observed a significant inverse relationship between FOXA1 and choline kinase expression and propose that it could act as a modulator of the Twist/choline kinase axis. The data presented indicate that Twist is a driver of choline kinase expression in breast cancer cells via FOXA1 resulting in the generation of an aggressive breast cancer phenotype.

Gender differences in GRK2 in cardiovascular diseases and its interactions with estrogen

G protein-coupled receptor kinase 2 (GRK2) is a multifunctional protein involved in regulating G protein-coupled receptor (GPCR) and non-GPCR signaling in the body. In the cardiovascular system, increased expression of GRK2 has been implicated in the occurrence and development of several cardiovascular diseases (CVDs). Recent studies have found gender differences in GRK2 in the cardiovascular system under physiological and pathological conditions, where GRK2's expression and activity are increased in males than in females. The incidence of CVDs in premenopausal women is lower than in men of the same age, which is related to estrogen levels. Given the shared location of GRK2 and estrogen receptors, estrogen may interact with GRK2 by modulating vital molecules such as calmodulin (CaM), caveolin, RhoA, nitrate oxide (NO), and mouse double minute 2 homolog (Mdm2), via signaling pathways mediated by estrogen's genomic (ERα and ERβ), and non-genomic (GPER) receptors, conferring cardiovascular protection in females. Highlighting the gender differences in GRK2 and understanding its interaction with estrogen in the cardiovascular system is pertinent in treating gender-related CVDs. As a result, this article explores the gender differences of GRK2 in the cardiovascular system and its relationship with estrogen during disease conditions. Estrogen's protective and therapeutic effects and its mechanism on GRK2-related cardiovascular diseases have also been discussed.

Role of the cGAS-STING pathway in regulating the tumor-immune microenvironment in dMMR/MSI colorectal cancer

Deficient mismatch repair (dMMR)/microsatellite instability (MSI) colorectal cancer (CRC) has high immunogenicity and better prognosis compared with proficient MMR (pMMR)/microsatellite stable (MSS) CRC. Although the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been considered to contribute to the high number of CD8⁺ TILs, its role in dMMR/MSI CRC is largely unknown. In this study, to examine the role of the cGAS-STING pathway on the recruitment of CD8⁺ TILs in dMMR/MSI CRC, we used public datasets and clinical tissue samples in our cohorts to evaluate the expression of cGAS, STING, and CD8⁺ TILs in pMMR/MSS and dMMR/MSI CRCs. According to the analysis of public datasets, the expression of cGAS-STING, CD8 effector gene signature, and CXCL10-CCL5, chemoattractants for CD8⁺ TILs which regulated by the cGAS-STING pathway, was significantly upregulated in dMMR/MSI CRC, and the expression of cGAS-STING was significantly associated with the expression of CD8 effector gene signature. Immunohistochemistry staining of the clinical tissue samples (n = 283) revealed that cGAS-STING was highly expressed in tumor cells of dMMR CRC, and higher expression of cGAS-STING in tumor cells was significantly associated with the increased number of CD8⁺ TILs. Moreover, we demonstrated that the downregulation of MMR gene in human CRC cell lines enhanced the activation of the cGAS-STING pathway. Taken together, for the first time, we found that dMMR/MSI CRC has maintained a high level of cGAS-STING expression in tumor cells, which might contribute to abundant CD8⁺ TILs and immune-active TME.

G protein-coupled receptor signaling: transducers and effectors

G protein-coupled receptors (GPCRs) are of considerable interest due to their importance in a wide range of physiological functions and in a large number of Food and Drug Administration (FDA)-approved drugs as therapeutic entities. With continued study of their function and mechanism of action, there is a greater understanding of how effector molecules interact with a receptor to initiate downstream effector signaling. This review aims to explore the signaling pathways, dynamic structures, and physiological relevance in the cardiovascular system of the three most important GPCR signaling effectors: heterotrimeric G proteins, GPCR kinases (GRKs), and β-arrestins. We will first summarize their prominent roles in GPCR pharmacology before transitioning into less well-explored areas. As new technologies are developed and applied to studying GPCR structure and their downstream effectors, there is increasing appreciation for the elegance of the regulatory mechanisms that mediate intracellular signaling and function.

The prognostic impact of B7-H3 and B7-H4 in head and neck squamous cell carcinoma

PURPOSE

Immune checkpoint inhibition is a therapeutic option in many cancer entities. In head and neck squamous cell carcinoma (HNSCC) targeting of the PD-1/PD-L1 (B7-H1) axis is approved in recurrent/metastatic disease and is being explored in the curative setting. Here, we evaluated two related members of the B7 family, B7-H3 & B7-H4, for their prognostic impact under standard treatment.

METHODS

A tissue microarray (TMA) of a single center HNSCC cohort was stained for B7-H3 and B7-H4. Staining intensity and the number of tumor cells stained were assessed, and the expression was scored according to an established algorithm. Staining scores were correlated with clinicopathological parameters and associated with patient survival. mRNA levels of both proteins were associated with patient outcome using the TCGA dataset.

RESULTS

mRNA levels of B7-H3 and B7-H4 were not significantly associated with patient survival. TMA analysis revealed interpretable protein staining in 408 samples. Strong staining was the most frequent category for B7-H3 and no staining for B7-H4. In patients with p16-negative oropharyngeal SCC (OPSCC) and in a pooled cohort consisting of p16-negative OPSCC, laryngeal, hypopharyngeal and oral cavity SCC, strong B7-H3 expression was associated with better overall survival. For the latter cohort, this was in part due to reduced lymph node involvement. B7-H3 expression in p16-positive OPSCC and B7-H4 expression were not associated with outcome.

CONCLUSION

Despite a possible role in tumor immune escape, B7-H3 was associated with favorable prognosis in HPV-negative HNSCC in our cohort. The underlying mechanisms and a potential impact for B7-H3 targeting remain to be elucidated.

Comprehensive transcriptomic and co-expression analysis of ABL1 gene and molecularly targeted drugs in hepatocellular carcinoma based on multi-database mining

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. Consequently, it is essential to identify biomarkers for treatment response and the prognosis prediction. We investigated whether ABL1 can function as a biomarker or a drug target for HCC. We assessed the ABL1 expression, genetic alterations and patients' survival from LinkedOmics, GEO, TCGA and Human Protein Atlas. We analyzed PPI, GO and KEGG pathways. GSEA was analyzed for functional comparison. The current drugs targeting ABL1 were statistically analyzed using DRUGSURV and DGIdb database. We found ABL1 is overexpressed in HCC and its higher expression reduces survival probability. Genetic changes of ABL1 are not frequent. We screened out 25 differentially expressed genes correlated with ABL1. The top functions of ABL1 are biological regulation, metabolic process, protein-containing, and protein binding. KEGG pathways showed that ABL1 and correlated with ABL1 significantly genes markedly enriched in the ErbB signaling pathway, and pathways in cancer. We counted the existing drugs targeting ABL1, which indicates that inhibiting ABL1 expression may improve the survival probability of HCC. In conclusion, ABL1 plays a crucial role in the development and progression of this cancerization and is a potential drug target.

Patients deriving long-term benefit from immune checkpoint inhibitors demonstrate conserved patterns of site-specific mutations

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and are now the preferred treatment for several tumor types. Though ICIs have shown remarkable efficacy in several cancer histologies, in many cases providing long-term disease control, not all patients will derive clinical benefit from such approaches. Given the lack of a reliable predictive biomarker for therapeutic responses to ICIs, we conducted a retrospective analysis of publicly available genomic data from a large pan-cancer cohort of patients receiving ICI-based immunotherapy. Consistent with previous results, patients in the combined cohort deriving a long-term survival benefit from ICIs were more likely to have a higher tumor mutational burden (TMB). However, this was not uniform across tumor-types, failing to predict for long-term survivorship in most non-melanoma cancers. Interestingly, long-term survivors in most cancers had conserved patterns of mutations affecting several genes. In melanoma, this included mutations affecting TET1 or PTPRD. In patients with colorectal cancer, mutations affecting TET1, RNF43, NCOA3, LATS1, NOTCH3, or CREBBP were also associated with improved prognosis, as were mutations affecting PTPRD, EPHA7, NTRK3, or ZFHX3 in non-small cell lung cancer, RNF43, LATS1, or CREBBP mutations in bladder cancer, and VHL mutations in renal cell carcinoma patients. Thus, this study identified several genes that may have utility as predictive biomarkers for therapeutic responses in patients receiving ICIs. As many have no known relationship to immunotherapy or ICIs, these genes warrant continued exploration, particularly for cancers in which established biomarkers such as PD-L1 expression or TMB have little predictive value.

The close interaction between hypoxia-related proteins and metastasis in pancarcinomas

Many primary-tumor subregions exhibit low levels of molecular oxygen and restricted access to nutrients due to poor vascularization in the tissue, phenomenon known as hypoxia. Hypoxic tumors are able to regulate the expression of certain genes and signaling molecules in the microenvironment that shift it towards a more aggressive phenotype. The transcriptional landscape of the tumor favors malignant transformation of neighboring cells and their migration to distant sites. Herein, we focused on identifying key proteins that participate in the signaling crossroads between hypoxic environment and metastasis progression that remain poorly defined. To shed light on these mechanisms, we performed an integrated multi-omics analysis encompassing genomic/transcriptomic alterations of hypoxia-related genes and Buffa hypoxia scores across 17 pancarcinomas taken from the PanCancer Atlas project from The Cancer Genome Atlas consortium, protein-protein interactome network, shortest paths from hypoxia-related proteins to metastatic and angiogenic phenotypes, and drugs involved in current clinical trials to treat the metastatic disease. As results, we identified 30 hypoxia-related proteins highly involved in metastasis and angiogenesis. This set of proteins, validated with the MSK-MET Project, could represent key targets for developing therapies. The upregulation of mRNA was the most prevalent alteration in all cancer types. The highest frequencies of genomic/transcriptomic alterations and hypoxia score belonged to tumor stage 4 and positive metastatic status in all pancarcinomas. The most significantly associated signaling pathways were HIF-1, PI3K-Akt, thyroid hormone, ErbB, FoxO, mTOR, insulin, MAPK, Ras, AMPK, and VEGF. The interactome network revealed high-confidence interactions among hypoxic and metastatic proteins. The analysis of shortest paths revealed several ways to spread metastasis and angiogenesis from hypoxic proteins. Lastly, we identified 23 drugs enrolled in clinical trials focused on metastatic disease treatment. Six of them were involved in advanced-stage clinical trials: aflibercept, bevacizumab, cetuximab, erlotinib, ipatasertib, and panitumumab.

Untargeted Metabolomics Studies of H9c2 Cardiac Cells Submitted to Oxidative Stress, β-Adrenergic Stimulation and Doxorubicin Treatment: Investigation of Cardiac Biomarkers

One of the biggest challenges in the search for more effective treatments for diseases is understanding their etiology. Cardiovascular diseases (CVD) are an important example of this, given the high number of deaths annually. Oxidative stress (the imbalance between oxidant and antioxidant species in biological system) is one of the factors responsible for CVD occurrence, demanding extensive investigation. Excess of reactive oxygen species (ROS) are primarily responsible for this condition, and clinical and scientific literature have reported a significant increase in ROS when therapeutic drugs, such as doxorubicin and isoproterenol, are administered. In this context, the aim of this study is the investigation of potential biomarkers that might be associated with oxidative stress in cardiomyocytes. For this purpose, H9c2 cardiomyocytes were submitted to oxidative stress conditions by treatment with doxorubicin (DOX), isoproterenol (ISO) and hydrogen peroxide (PER). Metabolomics analyses of the cell extract and the supernatant obtained from the culture medium were then evaluated by CE-ESI(+)-TOF-MS. Following signal processing, statistical analyses, and molecular features annotations, the results indicate changes in the aspartate, serine, pantothenic acid, glycerophosphocholine and glutathione metabolism in the cell extract.

Smurf2 inhibition enhances chemotherapy and radiation sensitivity in non-small-cell lung cancer

Lung cancer has been the most common cancer worldwide for several decades. The outcomes of patients with locally advanced lung cancer remain dismal, and only a minority of patients survive more than 5 years. However, tumor therapeutic resistance mechanisms are poorly studied. Identification of therapeutic resistance pathways in lung cancer in order to increase the sensitivity of lung tumor cells to therapeutic agents is a crucial but challenging need. To identify novel genes that modulate the response to platinum-based therapy, we performed a genome-wide high-throughput ribonucleic acid interference (RNAi) screen via transfection of human lung cancer (PC9) cells with a viral short hairpin RNA (shRNA) library. We further validated a potential target via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic survival assays on PC9 and A549 lung tumor cells transfected with small interfering RNAs (siRNAs) to successfully downregulate protein expression and then treated with increasing doses of cisplatin or X-ray radiation. We determined protein expression by immunohistochemistry (IHC) after chemoradiotherapy and analyzed gene expression-based survival outcomes in two cohorts of human non-small-cell lung cancer (NSCLC) patients. The screen identified several targets involved in epithelial-to-mesenchymal transition (EMT), including Smurf1, Smurf2, YAP1, and CEBPZ, and glycolytic pathway proteins, including PFKFB3. Furthermore, we found that the small molecule proteasome inhibitor bortezomib significantly downregulated Smurf2 in lung cancer cells. The addition of bortezomib in combination with cisplatin and radiation therapy in PC9 and A549 cells led to an increase in deoxyribonucleic acid (DNA) double-strand breaks with increased numbers of γ-H2AX-positive cells and upregulation of apoptosis. Finally, we found that Smurf2 protein expression was upregulated in situ after treatment with cisplatin and radiation therapy in a relevant cohort of patients with stage III NSCLC. Additionally, Smurf2 gene expression was the strongest predictor of survival in patients with squamous NSCLC after chemotherapy or chemoradiotherapy. We successfully identified and validated Smurf2 as both a common modulator of resistance and an actionable target in lung cancer. These results suggest the urgent need to investigate clinical Smurf2 inhibition via bortezomib in combination with cisplatin and radiation for patients with locally advanced NSCLC.

Prognostic value of p16, p53, and pcna in sarcoma and an evaluation of immune infiltration

Background

p16, p53, and proliferating cell nuclear antigen (pcna) genes play significant roles in many chromatin modifications and have been found to be highly expressed in a variety of tumor tissues. Therefore, they have been used as target genes for some tumor therapies. However, the differential expressions of the p16, p53, and pcna genes in human sarcomas and their effects on prognosis have not been widely reported.

Methods

The Oncomine dataset was used to analyze the transcription levels of p16, p53, and pcna genes, and the gene expression profile interactive analysis (GEPIA) dataset was used to analyze the differential expressions of p16, p53, and pcna. The expression levels of p16, p53, and pcna were further analyzed by Western Blotting. GEPIA and Kaplan–Meier analyses were used to analyze the prognostic value of p16, p53, and pcna. Furthermore, p16, p53, and pcna gene mutations and their association with overall survival (OS) and disease-free survival (DFS) were analyzed using cBioPortal datasets. In addition, genes co-expressed with p16, p53, and pcna were analyzed using Oncomine. The DAVID dataset was used to analyze the functional enrichment of p16, p53, pcna, and their co-expressed genes by Gene Ontology (GO) and Metascape were used to construct a network map. Finally, the immune cell infiltration of p16, p53, and pcna in patients with sarcoma was reported by Tumor Immune Estimation Resource (TIMER).

Results

p16, p53, and pcna were up-regulated in human sarcoma tissues and almost all sarcoma cell lines. Western Blotting showed that the expression of p16, p53, and pcna was elevated in osteosarcoma cell lines. The expression of pcna was correlated with OS, the expression of p16, p53, and pcna was correlated with relapse-free survival, and the genetic mutation of p16 was negatively correlated with OS and DFS. We also found that p16, p53, and pcna genes were positively/negatively correlated with immune cell infiltration in sarcoma.

Conclusions

The results of this study showed that p16, p53, and pcna can significantly affect the survival and immune status of sarcoma patients. Therefore, p16, p53, and pcna could be used as potential biomarkers of prognosis and immune infiltration in human sarcoma and provide a possible therapeutic target for sarcoma.

Double life: How GRK2 and β-arrestin signaling participate in diseases

G-protein coupled receptor (GPCR) kinases (GRKs) and β-arrestins play key roles in GPCR and non-GPCR cellular responses. In fact, GRKs and arrestins are involved in a plethora of pathways vital for physiological maintenance of inter- and intracellular communication. Here we review decades of research literature spanning from the discovery, identification of key structural elements, and findings supporting the diverse roles of these proteins in GPCR-mediated pathways. We then describe how GRK2 and β-arrestins partake in non-GPCR signaling and briefly summarize their involvement in various pathologies. We conclude by presenting gaps in knowledge and our prospective on the promising pharmacological potential in targeting these proteins and/or downstream signaling. Future research is warranted and paramount for untangling these novel and promising roles for GRK2 and arrestins in metabolism and disease progression.

Multi-omics analyses provide novel biological insights to distinguish lobular ductal types of invasive breast cancers

BACKGROUND

Invasive lobular carcinoma (ILC) treatment is similar to invasive ductal carcinoma (IDC; now invasive carcinoma-no special type, IBC-NST), based on its intrinsic subtype. However, further investigation is required for an integrative understanding of differentially perturbed molecular patterns and pathways in these histotypes.

METHODS

A dataset of 780 IDC and 201 ILC samples from the TCGA-BRCA project for cross-platform multi-omics was analyzed. We leveraged a consensus approach integrating different bioinformatic algorithms to analyze mutations, CNAs, mRNA, miRNA abundance, methylation, and protein abundance to understand the complex crosstalks that distinguish ILC and IDC samples. A histotype-matched comparison was performed. We performed Cox survival analyses for prognosis based on our identified 53 histotype-specific and four discordant genes.

RESULTS

Approximately 90% of ILC cases were of the luminal subtype. Somatic mutations in CDH1 were higher in ILC than in IDC (FDR-adjusted p < 0.01). Fifty-three significant oncogenic or tumor-suppressive DEGs were identified in a single histotype. PPAR signaling and lipolysis regulation in adipocytes were significantly enriched in ILC tumors. CDH1 protein had the highest differential abundance (AUC: 0.85). Moreover, BTG2, GSTA2, GPR37L1, and PGBD5 amplification was associated with poorer OS in ILC compared with no alteration. RIMS2, NACA4P, MYC, ZFPM2, and POU5F1B amplification showed a lower overall survival in patients with IDC. miR-195 showed an IDC-specific downregulation, causing overexpression of CCNE1. Integrative multi-omics supervised analysis identified 296 differentially expressed genes that successfully distinguished IDC and ILC histotypes.

CONCLUSIONS

Our findings identify novel molecular candidates that potentially drive and modify the disease differentially among these histotypes.

Cell line models for drug discovery in PIK3CA-mutated colorectal cancers

Colorectal cancer remains a major cause of cancer-related morbidity and mortality. Metastatic disease is still incurable in most cases. New therapies based on a better understanding of the pathogenesis are needed to improve outcomes. Mutations in the catalytic sub-unit of kinase PI3K encoded by gene PIK3CA are common in colorectal cancer cell lines and patient samples. The characteristics of colorectal cancer cell lines from the Cancer Cell Line Encyclopedia (CCLE), with and without PIK3CA mutations, were evaluated and compared. A panel of colorectal cancer cell lines with and without PIK3CA mutations were compared for their sensitivity to PIK3 inhibitors. Concomitant molecular abnormalities of sensitive versus resistant cell lines were identified. Colorectal cancer cell lines with PIK3CA mutations are commonly diploid and have microsatellite instability (MSI) and a high tumor mutation burden (TMB), compared with cell lines without PIK3CA mutations. Cell lines with PIK3CA mutations tend to have higher sensitivity to some but not all PI3K inhibitors tested and display variability in sensitivity. Both cell lines with MSI and microsatellite stable (MSS) are among the most sensitive to PI3K inhibitors. Multiple concomitant mutations in the PI3K/AKT and KRAS/BRAF/MEK/ERK pathways are often observed in sensitive cell lines. In concordance with patient samples, colorectal cancer cell lines with PIK3CA mutations display more commonly MSI and tend to be more sensitive to PI3K inhibitors. Variability in sensitivity of PIK3CA-mutated cell lines suggests that additional molecular abnormalities contribute to sensitivity.

A bioinformatic analysis of WFDC2 (HE4) expression in high grade serous ovarian cancer reveals tumor-specific changes in metabolic and extracellular matrix gene expression

Human epididymis protein-4 (HE4/WFDC2) has been well-studied as an ovarian cancer clinical biomarker. To improve our understanding of its functional role in high grade serous ovarian cancer, we determined transcriptomic differences between ovarian tumors with high- versus low-WFDC2 mRNA levels in The Cancer Genome Atlas dataset. High-WFDC2 transcript levels were significantly associated with reduced survival in stage III/IV serous ovarian cancer patients. Differential expression and correlation analyses revealed secretory leukocyte peptidase inhibitor (SLPI/WFDC4) as the gene most positively correlated with WFDC2, while A kinase anchor protein-12 was most negatively correlated. WFDC2 and SLPI were strongly correlated across many cancers. Gene ontology analysis revealed enrichment of oxidative phosphorylation in differentially expressed genes associated with high-WFDC2 levels, while extracellular matrix organization was enriched among genes associated with low-WFDC2 levels. Immune cell subsets found to be positively correlated with WFDC2 levels were B cells and plasmacytoid dendritic cells, while neutrophils and endothelial cells were negatively correlated with WFDC2. Results were compared with DepMap cell culture gene expression data. Gene ontology analysis of k-means clustering revealed that genes associated with low-WFDC2 were also enriched in extracellular matrix and adhesion categories, while high-WFDC2 genes were enriched in epithelial cell proliferation and peptidase activity. These results support previous findings regarding the effect of HE4/WFDC2 on ovarian cancer pathogenesis in cell lines and mouse models, while adding another layer of complexity to its potential functions in ovarian tumor tissue. Further experimental explorations of these findings in the context of the tumor microenvironment are merited.

Fructose-1,6-bisphosphatase 1 (FBP1) is an independent biomarker associated with a favorable prognosis in esophageal adenocarcinoma

Introduction

Despite modern multimodal therapeutic regimens, the prognosis of esophageal adenocarcinoma (EAC) is still poor and there is a lack of biological markers estimating the patients’ prognosis. Fructose-1,6-biphosphatase (FBP1) is a key enzyme in gluconeogenesis and is associated with tumor initiation in several cancers. Therefore, this study aims to characterize its implication for EAC patients.

Methods and materials

A total of 571 EAC patients who underwent multimodal treatment between 1999 and 2017 were analyzed for FBP1 expression using immunohistochemistry.

Results

82.5% of the EACs show FBP1 expression in the tumor albeit with different intensities categorizing specimens accordingly into score 0 (no expression), score 1 (weak expression), score 2 (moderate expression) and score 3 (strong expression) (score 1 = 25.0%, score 2 = 35.9%, score 3 = 21.5%). Intratumoral FBP1 expression was significantly associated with a better prognosis (p = 0.024). This observation was particularly relevant among patients who received primary surgery without neoadjuvant treatment (p = 0.004). In multivariate analysis, elevated FBP1 expression was an independent biomarker associated with a favorable prognosis.

Discussion

Despite being associated with a favorable prognosis, the majority of patients with high FBP1 expression also require individualized therapy options to ensure long-term survival. Recently, it has been shown that the presence of the FBP1 protein increases the sensitivity of pancreatic cancer cells to the bromodomain and extraterminal domain (BET) inhibitor JQ1.

Conclusion

We described for the first time the prognostic and possibly therapeutic relevance of FBP1 in EAC. The efficiency of the BET inhibitor in EAC should be verified in clinical studies and special attention should be paid to the effects of neoadjuvant therapy on FBP1 expression.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-022-04025-x.

Comprehensive analysis of the expression, prognosis, and immune infiltrates for CHDs in human lung cancer

BACKGROUND

The chromodomain helicase DNA-binding (CHD) family, a group of genes that regulate nucleosome spacing and access to transcription factors, contributes to tumorigenesis in various cancers. However, the roles of CHD family members in lung cancer remain poorly understood.

METHODS

We investigated the transcriptional, survival, and immune data of CHDs in patients with lung cancer from the Oncomine, UALCAN, GEPIA, Kaplan-Meier Plotter, TCGA, TIMER, cBioPortal, and CR2Cancer databases. Then, perform functional enrichment analysis of CHDs was performed using the Metascape. Finally, the expression of CHD7, CHD8 and DNA damage response genes were evaluated by quantitative real-time PCR and western blot.The effects of CHD7 or CHD8 knockdown on A549 and PC9 cells were measured in vitro by flow cytometry, cell viability and colony formation assays.

RESULTS

We found that except for CHD5, nearly all members of CHDs in lung cancer showed altered expression compared with adjacent normal tissues. Moreover, the abnormal expression levels of CHDs were related to the clinical outcome of patients with lung adenocarcinoma and, to a lesser extent, patients with lung squamous cell carcinoma, which were significantly associated with the immune infiltrating levels of immune cells. Furthermore, the functions of CHDs and their neighboring genes are mainly related to DNA repair, the cell cycle, and organelle organization. Finally, cellular experiments conducted in vitro confirmed that CHD7/8 played indispensable roles in DNA damage signaling and cell cycle progression in lung adenocarcinoma cells.

CONCLUSION

This study implied that CHD family members, especially in subclass III, are potential targets of precision therapy and new biomarkers for patients with lung cancer.

Identification of a novel cancer microbiome signature for predicting prognosis of human breast cancer patients

BACKGROUND

Prognosis of breast cancer (BC) patients differs considerably and identifying reliable prognostic biomarker(s) is imperative. With evidence that the microbiome plays a critical role in the response to cancer therapies, we aimed to identify a cancer microbiome signature for predicting the prognosis of BC patients.

METHODS

The TCGA BC microbiome data (TCGA-BRCA-microbiome) was downloaded from cBioPortal. Univariate and multivariate Cox regression analyses were used to examine association of microbial abundance with overall survival (OS) and to identify a microbial signature for creating a prognostic scoring model. The performance of the scoring model was assessed by the area under the ROC curve (AUC). Nomograms using the microbial signature, clinical factors, and molecular subtypes were established to predict OS and progression-free survival (PFS).

RESULTS

Among 1406 genera, the abundances of 94 genera were significantly associated with BC patient OS in TCGA-BRCA-microbiome dataset. From that set we identified a 15-microbe prognostic signature and developed a 15-microbial abundance prognostic scoring (MAPS) model. Patients in low-risk group significantly prolong OS and PFS as compared to those in high-risk group. The time-dependent ROC curves with MAPS showed good predictive efficacy both in OS and PFS. Moreover, MAPS is an independent prognostic factor for OS and PFS over clinical factors and PAM50-based molecular subtypes and superior to the previously published 12-gene signature. The integration of MAPS into nomograms significantly improved prognosis prediction.

CONCLUSION

MAPS was successfully established to have independent prognostic value, and our study provides a new avenue for developing prognostic biomarkers by microbiome profiling.

As a prognostic biomarker of clear cell renal cell carcinoma RUFY4 predicts immunotherapy responsiveness in a PDL1-related manner

Background

Clear cell renal cell carcinoma (ccRCC) is one of the most lethal malignancies in the urinary system and the existing immunotherapy has not achieved satisfactory outcomes. Therefore, this study aims at establishing a novel gene signature for immune infiltration and clinical outcome (overall survival and immunotherapy responsiveness) in ccRCC patients.

Methods

Based on RNA sequencing data and clinical information in The Cancer Genome Atlas (TCGA) database, we calculated proportions of immune cells in 611 samples using an online tool CIBERSORTx. Multivariate survival analysis was conducted to determine crucial survival-associated immune cells and immune-infiltration-related genes (IIRGs). Next, the clinical specimens and common renal cancer cell lines were applied to confirm IIRGs expression at protein and RNA levels. Finally, functional enrichment analyses and siRNA technology targeted to RUFY4 were implemented to verify its function of predicting immunotherapy response.

Results

Follicular helper T cells (TFHs) and Regulatory T cells (Tregs) were highly infiltrated in the tumor microenvironment (TME) and their relative proportions were independent prognostic factors for patients. Among IIRGs of TFHs and TREGs, RUFY4 was found to be highly activated in tumor microenvironment and its co-expression network was enriched in PDL1/PD1 checkpoint pathway in cancer. Additionally, knockdown of RUFY4 led to the decline of PDL1 and proliferation ability in ccRCC cell lines.

Conclusion

TFHs and Tregs were considered as prognostic biomarkers and RUFY4 was an immunotherapeutic predictor of ccRCC patients in a PDL1-Related manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02480-7.

Lower RNA expression of ALDH1A1 distinguishes the favorable risk group in acute myeloid leukemia

The expression and activity of enzymes that belong to the aldehyde dehydrogenases is a characteristic of both normal and malignant stem cells. ALDH1A1 is an enzyme critical in cancer stem cells. In acute myeloid leukemia (AML), ALDH1A1 protects leukemia-initiating cells from a number of antineoplastic agents, which include inhibitors of protein tyrosine kinases. Furthermore, ALDH1A1 proves vital for the establishment of human AML xenografts in mice. We review here important studies characterizing the role of ALDH1A1 in AML and its potential as a therapeutic target. We also analyze datasets from leading studies, and show that decreased ALDH1A1 RNA expression consistently characterizes the AML patient risk group with a favorable prognosis, while there is a consistent association of high ALDH1A1 RNA expression with high risk and poor overall survival. Our review and analysis reinforces the notion to employ both novel as well as existing inhibitors of the ALDH1A1 protein against AML.

Chemogenetic Approaches to Probe Redox Pathways: Implications for Cardiovascular Pharmacology and Toxicology

Chemogenetics refers to experimental systems that dynamically regulate the activity of a recombinant protein by providing or withholding the protein's specific biochemical stimulus. Chemogenetic tools permit precise dynamic control of specific signaling molecules to delineate the roles of those molecules in physiology and disease. Yeast d-amino acid oxidase (DAAO) enables chemogenetic manipulation of intracellular redox balance by generating hydrogen peroxide only in the presence of d-amino acids. Advances in biosensors have allowed the precise quantitation of these signaling molecules. The combination of chemogenetic approaches with biosensor methodologies has opened up new lines of investigation, allowing the analysis of intracellular redox pathways that modulate physiological and pathological cell responses. We anticipate that newly developed transgenic chemogenetic models will permit dynamic modulation of cellularredox balance in diverse cells and tissues and will facilitate the identification and validation of novel therapeutic targets involved in both physiological redox pathways and pathological oxidative stress.

Yeast-based screening of cancer mutations in the DNA damage response protein Mre11 demonstrates importance of conserved capping domain residues

DNA damage response (DDR) pathways are initiated to prevent mutations from being passed on in the event of DNA damage. Mutations in DDR proteins can contribute to the development and maintenance of cancer cells, but many mutations observed in human tumors have not been functionally characterized. Because a proper response to DNA damage is fundamental to living organisms, DDR proteins and processes are often highly conserved. The goal of this project was to use Saccharomyces cerevisiae as a model for functional screening of human cancer mutations in conserved DDR proteins. After comparing the cancer mutation frequency and conservation of DDR proteins, Mre11 was selected for functional screening. A subset of mutations in conserved residues was analyzed by structural modeling and screened for functional effects in yeast Mre11. Yeast expressing wild type or mutant Mre11 were then assessed for DNA damage sensitivity using hydroxyurea (HU) and methyl methanesulfonate (MMS). The results were further validated in human cancer cells. The N-terminal point mutations tested in yeast Mre11 do not confer sensitivity to DNA damage sensitivity, suggesting that these residues are dispensable for yeast Mre11 function and may have conserved sequence without conserved function. However, a mutation near the capping domain associated with breast and colorectal cancers compromises Mre11 function in both yeast and human cells. These results provide novel insight into the function of this conserved capping domain residue and demonstrate a framework for yeast-based screening of cancer mutations.

Comprehensive analysis of prognostic value and immune infiltration of kindlin family members in non-small cell lung cancer

BACKGROUND

Kindlin Family Members have been reported to be aberrantly expressed in various human cancer types and involved in tumorigenesis, tumor progression, and chemoresistance. However, their roles in non-small cell lung cancer (NSCLC) remain poorly elucidated.

METHODS

We analyzed the prognostic value and immune infiltration of Kindlins in NSCLC through Oncomine, GEPIA, UALCAN, CCLE, Kaplan‑Meier plotter, cBioPortal, TIMER, GeneMANIA, STRING, and DAVID database. Additionally, the mRNA expression levels of Kindlins were verified in 30 paired NSCLC tissues and NSCLC cell lines by real-time PCR.

RESULTS

The expression level of FERMT1 was remarkably increased in NSCLC tissues and NSCLC cell lines, while FERMT2 and FERMT3 were reduced. Kindlins expressions were associated with individual cancer stages and nodal metastasis. We also found that higher expression level of FERMT1 was obviously correlated with worse overall survival (OS) in patients with NSCLC, while higher FERMT2 was strongly associated with better overall survival (OS) and first progression (FP). Additionally, the expression of FERMT2 and FERMT3 were obviously correlated with the immune infiltration of diverse immune cells. Functional enrichment analysis has shown that Kindlins may be significantly correlated with intracellular signal transduction, ATP binding and the PI3K-Akt signaling pathway in NSCLC.

CONCLUSIONS

The research provides a new perspective on the distinct roles of Kindlins in NSCLC and likely has important implications for future novel biomarkers and therapeutic targets in NSCLC.

Incidence, clinicopathologic, and genetic characteristics of mismatch repair gene-mutated glioblastomas

BACKGROUND

Glioblastoma (GBM) is the most common and malignant gliomas of adults and recur, resulting in death, despite surgery, radiotherapy, and temozolomide-based chemotherapy. There are a few reports on immunotherapy for the mismatch repair (MMR)-deficient GBMs with high tumor mutational burden (TMB). However, the clinicopathological and genetic features of the MMR genes altered in GBMs have not been elucidated yet.

METHODS

The authors analyzed targeted next-generation sequencing (NGS) data from 282 (276 primary and 6 recurrent) glioblastomas to evaluate the mutational status of six DNA repair-related genes: MLH1, MSH2, MSH6, PMS2, POLE, and POLD1. Tumors harboring somatic or germline mutations in one or more of these six genes were classified as an MMR gene-altered GBM. The clinicopathologic and molecular characteristics of MMR gene-altered GBMs were compared to those of tumors without MMR gene alterations.

RESULTS

Sixty germline or somatic mutations were identified in 37 cases (35 primary and two recurrent) of GBM. The most frequently mutated genes were MSH6 and POLE. Single nucleotide variants were the most common, followed by frameshift deletions or insertions and approximately 60% of the mutations were germline mutations. Two patients who showed MSH2 (c.2038C > T) and MSH6 (c.1082G > A) mutations had familial colon cancer. The clinical findings were not different between the two groups. However, the presence of MGMT promoter methylation and high tumor mutation burden (TMB) values (> 20) were correlated with MMR gene alterations.

CONCLUSION

Since MMR-related genes can be found even in primary glioblastoma and are correlated with high TMB and MGMT promoter methylation, MMR genes should be carefully analyzed in NGS study on glioblastomas.

SWI/SNF chromatin remodeling complex alterations in meningioma

PURPOSE

While SWI/SNF chromatin remodeling complex alterations occur in approximately 20% of cancer, the frequency and potential impact on clinical outcomes in meningiomas remains to be comprehensively elucidated.

METHODS

A large series of 255 meningiomas from a single institution that was enriched for high grade and recurrent lesions was identified. We performed next-generation targeted sequencing of known meningioma driver genes, including NF2, AKT1, PIK3CA, PIK3R1, and SMO and SWI/SNF chromatin remodeling complex genes, including ARID1A, SMARCA4, and SMARCB1 in all samples. Clinical correlates focused on clinical presentation and patient outcomes are presented.

RESULTS

The series included 63 grade I meningiomas and 192 high-grade meningiomas, including 173 WHO grade II and 19 WHO grade III. Samples from recurrent surgeries comprised 37.3% of the series. A total of 41.6% meningiomas were from the skull base. NF2, AKT1, PIK3CA, PIK3R1, and SMO were mutated in 40.8, 7.1, 3.5, 3.9, and 2.4% of samples, respectively. ARID1A, SMARCA4, and SMARCB1 mutations were observed in 17.3, 3.5, and 5.1% of samples, respectively. A total of 68.2% of ARID1A-mutant meningiomas harbored a p.Gln1327del in-frame deletion. ARID1A mutations were seen in 19.1% of Grade I, 16.8% of Grade II, and 15.8% of Grade III meningiomas (P = 0.9, Fisher's exact). Median overall survival was 16.3 years (95% CI 10.9, 16.8). With multivariable analysis, the presence of an ARID1A mutation was significantly associated with a 7.421-fold increased hazard of death (P = 0.04).

CONCLUSION

ARID1A mutations occur with similar frequency between low and high-grade meningiomas, but ARID1A mutations are independently prognostic of worse prognosis beyond clinical and histopathologic features.

Heterodimerization With 5-HT2BR Is Indispensable for β2AR-Mediated Cardioprotection

RATIONALE

The β2-adrenoceptor (β2-AR), a prototypical GPCR (G protein-coupled receptor), couples to both Gs and Gi proteins. Stimulation of the β2-AR is beneficial to humans and animals with heart failure presumably because it activates the downstream Gi-PI3K-Akt cell survival pathway. Cardiac β2-AR signaling can be regulated by crosstalk or heterodimerization with other GPCRs, but the physiological and pathophysiological significance of this type of regulation has not been sufficiently demonstrated.

OBJECTIVE

Here, we aim to investigate the potential cardioprotective effect of β2-adrenergic stimulation with a subtype-selective agonist, (R,R')-4-methoxy-1-naphthylfenoterol (MNF), and to decipher the underlying mechanism with a particular emphasis on the role of heterodimerization of β2-ARs with another GPCR, 5-hydroxytryptamine receptors 2B (5-HT2BRs).

METHODS AND RESULTS

Using pharmacological, genetic and biophysical protein-protein interaction approaches, we studied the cardioprotective effect of the β2-agonist, MNF, and explored the underlying mechanism in both in vivo in mice and cultured rodent cardiomyocytes insulted with doxorubicin, hydrogen peroxide (H2O2) or ischemia/reperfusion. In doxorubicin (Dox)-treated mice, MNF reduced mortality and body weight loss, while improving cardiac function and cardiomyocyte viability. MNF also alleviated myocardial ischemia/reperfusion injury. In cultured rodent cardiomyocytes, MNF inhibited DNA damage and cell death caused by Dox, H2O2 or hypoxia/reoxygenation. Mechanistically, we found that MNF or another β2-agonist zinterol markedly promoted heterodimerization of β2-ARs with 5-HT2BRs. Upregulation of the heterodimerized 5-HT2BRs and β2-ARs enhanced β2-AR-stimulated Gi-Akt signaling and cardioprotection while knockdown or pharmacological inhibition of the 5-HT2BR attenuated β2-AR-stimulated Gi signaling and cardioprotection.

CONCLUSIONS

These data demonstrate that the β2-AR-stimulated cardioprotective Gi signaling depends on the heterodimerization of β2-ARs and 5-HT2BRs.

Interferon regulatory factor 1 (IRF-1) and IRF-2 regulate PD-L1 expression in hepatocellular carcinoma (HCC) cells

The objective response rate of immune checkpoint blockade (ICB) in hepatocellular carcinoma (HCC) with anti PD-L1/PD-1 therapy is low. Discovering the signaling pathways regulating PD-L1 might help to improve ICB response rates. Here, we investigate transcription factors IRF-1 and IRF-2 signaling pathways regulating PD-L1 in HCC cells. In vivo studies show that IRF-1 and PD-L1 mRNA expression in human HCC tumors are significantly repressed compared with noncancerous background liver. IRF-1, IRF-2, and PD-L1 mRNA expression correlated positively in HCC tumors. Increased IRF-1 mRNA expression was observed in patients with well-differentiated or early stage HCC tumors. In vitro studies show that IFN-γ induces PD-L1 mRNA and protein expression through upregulation of IRF-1 in mouse and human HCC cells. IRF-1, IRF-2, and PD-L1 mRNA expression is upregulated in murine HCC by co-culture with effector T cells from spleen cells incubated with anti-CD3/CD28 antibodies. IRF-2 over-expression down-regulates IFN-γ induced PD-L1 promoter activity and protein levels in a dose-dependent manner. We identify two IRF-1 response elements (IRE1/IRE2) in the upstream 5'-flanking region of the CD274 (PD-L1) gene promoter. Site-directed mutagenesis shows both IRE1 and IRE2 are functional in transfection promoter assays. IRF-1 traditionally functions as tumor suppressor gene. However, these novel findings show a complex role for IRF-1 which upregulates PD-L1 in the inflammatory tumor microenvironment. IRF-1 antagonizes IRF-2 for binding to the IRE promoter element in PD-L1 which gives new insight to the regulation of PD-L1/PD-1 pathways in HCC ICB therapy.

Angiotensin Receptors Heterodimerization and Trafficking: How Much Do They Influence Their Biological Function?

G-protein–coupled receptors (GPCRs) are targets for around one third of currently approved and clinical prescribed drugs and represent the largest and most structurally diverse family of transmembrane signaling proteins, with almost 1000 members identified in the human genome. Upon agonist stimulation, GPCRs are internalized and trafficked inside the cell: they may be targeted to different organelles, recycled back to the plasma membrane or be degraded. Once inside the cell, the receptors may initiate other signaling pathways leading to different biological responses. GPCRs’ biological function may also be influenced by interaction with other receptors. Thus, the ultimate cellular response may depend not only on the activation of the receptor from the cell membrane, but also from receptor trafficking and/or the interaction with other receptors. This review is focused on angiotensin receptors and how their biological function is influenced by trafficking and interaction with others receptors.

Expanding cancer predisposition genes with ultra-rare cancer-exclusive human variations

It is estimated that up to 10% of cancer incidents are attributed to inherited genetic alterations. Despite extensive research, there are still gaps in our understanding of genetic predisposition to cancer. It was theorized that ultra-rare variants partially account for the missing heritable component. We harness the UK BioBank dataset of ~ 500,000 individuals, 14% of which were diagnosed with cancer, to detect ultra-rare, possibly high-penetrance cancer predisposition variants. We report on 115 cancer-exclusive ultra-rare variations and nominate 26 variants with additional independent evidence as cancer predisposition variants. We conclude that population cohorts are valuable source for expanding the collection of novel cancer predisposition genes.

Loss of dynamic regulation of G protein-coupled receptor kinase 2 by nitric oxide leads to cardiovascular dysfunction with aging

Nitric oxide (NO) and S-nitrosothiol (SNO) are considered cardio- and vasoprotective substances. We now understand that one mechanism in which NO/SNOs provide cardiovascular protection is through their direct inhibition of cardiac G protein-coupled receptor (GPCR) kinase 2 (GRK2) activity via S-nitrosylation of GRK2 at cysteine 340 (C340). This maintains GPCR homeostasis, including β-adrenergic receptors, through curbing receptor GRK2-mediated desensitization. Previously, we have developed a knockin mouse (GRK2-C340S) where endogenous GRK2 is resistant to dynamic S-nitrosylation, which led to increased GRK2 desensitizing activity. This unchecked regulation of cardiac GRK2 activity resulted in significantly more myocardial damage after ischemic injury that was resistant to NO-mediated cardioprotection. Although young adult GRK2-C340S mice show no overt phenotype, we now report that as these mice age, they develop significant cardiovascular dysfunction due to the loss of SNO-mediated GRK2 regulation. This pathological phenotype is apparent as early as 12 mo of age and includes reduced cardiac function, increased cardiac perivascular fibrosis, and maladaptive cardiac hypertrophy, which are common maladies found in patients with cardiovascular disease (CVD). There are also vascular reactivity and aortic abnormalities present in these mice. Therefore, our data demonstrate that a chronic and global increase in GRK2 activity is sufficient to cause cardiovascular remodeling and dysfunction, likely due to GRK2’s desensitizing effects in several tissues. Because GRK2 levels have been reported to be elevated in elderly CVD patients, GRK2-C340 mice can give insight into the aged-molecular landscape leading to CVD.

NEW & NOTEWORTHY Research on G protein-coupled receptor kinase 2 (GRK2) in the setting of cardiovascular aging is largely unknown despite its strong established functions in cardiovascular physiology and pathophysiology. This study uses a mouse model of chronic GRK2 overactivity to further investigate the consequences of long-term GRK2 on cardiac function and structure. We report for the first time that chronic GRK2 overactivity was able to cause cardiac dysfunction and remodeling independent of surgical intervention, highlighting the importance of GRK activity in aged-related heart disease.

An emerging perspective on sex differences: Intersecting S-nitrosothiol and aldehyde signaling in the heart

Cardiovascular disease is the leading cause of the death for both men and women. Although baseline heart physiology and the response to disease are known to differ by sex, little is known about sex differences in baseline molecular signaling, especially with regard to redox biology. In this review, we describe current research on sex differences in cardiac redox biology with a focus on the regulation of nitric oxide and aldehyde signaling. Furthermore, we argue for a new perspective on cardiovascular sex differences research, one that focuses on baseline redox biology without the elimination or disruption of sex hormones.

G protein-coupled receptor kinase 2 (GRK2) as a multifunctional signaling hub

Accumulating evidence indicates that G protein-coupled receptor kinase 2 (GRK2) is a versatile protein that acts as a signaling hub by modulating G protein-coupled receptor (GPCR) signaling and also via phosphorylation or scaffolding interactions with an extensive number of non-GPCR cellular partners. GRK2 multifunctionality arises from its multidomain structure and from complex mechanisms of regulation of its expression levels, activity, and localization within the cell, what allows the precise spatio-temporal shaping of GRK2 targets. A better understanding of the GRK2 interactome and its modulation mechanisms is helping to identify the GRK2-interacting proteins and its substrates involved in the participation of this kinase in different cellular processes and pathophysiological contexts.

Fast relaxation and desensitization of angiotensin II contraction in the pulmonary artery via AT1R and Akt-mediated phosphorylation of muscular eNOS

Angiotensin II (AngII) triggers a transient contraction of pulmonary arteries (PAs) followed by protracted desensitization. Based on the unconventional eNOS expression in PA smooth muscle cells (PASMCs), we hypothesized that activation of smooth muscle eNOS by AngII might be responsible for fast relaxation and tachyphylaxis. Using dual-wire myograph, mechanically endothelium-denuded rat PA [E(-)PA] showed AngII concentration-dependent transient contractions (ΔT_AngII, 95% decay within 1 min), which were abolished by losartan (AT1R antagonist). Neither PD123319 (AT2R antagonist) nor A779 (MasR antagonist) affected ΔT_AngII. When the vessels were pretreated with L-NAME (NOS inhibitor), ODQ (guanylate cyclase inhibitor), or KT5823 (PKG inhibitor), ΔT_AngII of E(-)PA became larger and sustained, whereas nNOS or iNOS inhibitors had no such effect. Immunoblotting of human PASMCs (hPASMCs) also showed eNOS expression, and AngII treatment induced activating phosphorylations of Ser¹¹⁷⁷ in eNOS and of Ser⁴⁷³ in Akt (Ser/Thr protein kinase B), an upstream signal of eNOS phosphorylation. In addition, L-NAME co-treatment promoted AngII-induced Ser¹⁹ phosphorylation of myosin light chain. In hPASMCs, AngII abolished plasma membrane expression of AT1R, and recovery by washout took more than 1 h. Consistent with the data from hPASMCs, the second application of AngII to E(-)PA did not induce contraction, and significant recovery of ΔT_AngII required prolonged washout (> 2 h) in the myography study. L-NAME treatment before the second application facilitated recovery of ΔT_AngII. Muscular eNOS plays an auto-inhibitory role in ΔT_AngII of PAs. The molecular changes investigated in hPASMCs revealed eNOS phosphorylation and internalization of AT1R by AngII. We propose that the rat PA smooth muscle eNOS-induced lusitropy and slow recovery of AT1R from tachyphylaxis might counterbalance the excessive contractile response to AngII, contributing to the distinctive low-pressure pulmonary circulation.

Integrated Functional Analysis of the Nuclear Proteome of Classically and Alternatively Activated Macrophages

Macrophages (Mφ) play a central role in coordinating host response to pathogens, cellular injury, and environmental stimuli. Herein, we report multidimensional, nuclear proteomic analyses of protein expression and posttranslational modifications (PTMs) that control biological processes during Mφ activation. For this, Mφ were incubated with IFN-γ/LPS and IL-4, and their differentiation to proinflammatory (M1) and anti-inflammatory (M2a, referred as M2 for simplicity throughtout the manuscript) phenotypes was confirmed by detection of CD64 and CD206 surface markers and TNF-α, arginase I, and iNOS-dependent nitrite levels. We used a sequential method of organellar enrichment and labeling of nuclear fractions with BODIPY FL-maleimide fluorescence dye followed by two-dimensional electrophoresis (2DE) to capture quantitative changes in abundance and S-nitrosylated (SNO) proteome signatures. Exact same gels were then labeled with Pro-Q Diamond to detect protein phosphorylation. MALDI-TOF/TOF MS analysis of the protein spots with fold change of ≥|1.5| in any of the groups yielded 229 identifications. We found that 145, 78, and 173 protein spots in M1 Mφ and 105, 81, and 164 protein spots in M2 Mφ were changed in abundance, S-nitrosylation, and phosphorylation, respectively, with respect to M0 controls (fold change: ≥|1.5|, p ≤ 0.05). Targeted analysis by immunoprecipitation and Western blotting was performed to verify the differential abundance and phosphorylation levels of two of the proteins in M1 and M2 (vs. M0) Mφ. Ingenuity Pathway Analysis of the nuclear proteome datasets showed that the abundance and posttranslational (SNO and Phosphor) modifications of the proteins predicted to be involved in cytoskeletal organization/cell movement, phagocytosis/endocytosis, and cell proliferation/cell death were differentially regulated with proinflammatory and anti-inflammatory activation of Mφ.

G Protein-Coupled Receptor Kinase 2 (GRK2) as a Potential Therapeutic Target in Cardiovascular and Metabolic Diseases

G protein-coupled receptor kinase 2 (GRK2) is a central signaling node involved in the modulation of many G protein-coupled receptors (GPCRs) and also displaying regulatory functions in other cell signaling routes. GRK2 levels and activity have been reported to be enhanced in patients or in preclinical models of several relevant pathological situations, such as heart failure, cardiac hypertrophy, hypertension, obesity and insulin resistance conditions, or non-alcoholic fatty liver disease (NAFLD), and to contribute to disease progression by a variety of mechanisms related to its multifunctional roles. Therefore, targeting GRK2 by different strategies emerges as a potentially relevant approach to treat cardiovascular disease, obesity, type 2 diabetes, or NAFLD, pathological conditions which are frequently interconnected and present as co-morbidities.

GRK2 and GRK5 as therapeutic targets and their role in maladaptive and pathological cardiac hypertrophy

INTRODUCTION

One in every four deaths in the United States is attributed to cardiovascular disease, hence the development and employment of novel and effective therapeutics are necessary to improve the quality of life and survival of affected patient. Pathological hypertrophy is a maladaptive response by the heart to relieve wall stress that could result from cardiovascular disease. Maladaptive hypertrophy can lead to further disease progression and complications such as heart failure; hence, efforts to target hypertrophy to prevent and treat further morbidity and mortality are necessary. Areas covered: This review summarizes the compelling literature that describes the mechanistic role of GRK2 and GRK5 in maladaptive cardiac hypertrophy; it examines the approaches to inhibit these kinases in hypertrophic animal models and furthermore, it assesses the potential of GRK2 and GRK5 as therapeutic targets for hypertrophy. Expert opinion: GRK2 and GRK5 are novel therapeutic targets for pathological hypertrophy and may have added benefits of ameliorating morbidity and mortality. Despite the lesser researched role of GRK2 in cardiac hypertrophy, it may be the advantageous strategy for treating cardiac hypertrophy because of its role in other maladaptive pathways. Anti-GRK2 therapy optimization and the discovery and development of specific GRK2 and GRK5 small-molecule inhibitors is necessary for the eventual application of successful, effective therapeutics.

Restricting mitochondrial GRK2 post-ischemia confers cardioprotection by reducing myocyte death and maintaining glucose oxidation

Increased abundance of GRK2 [G protein-coupled receptor (GPCR) kinase 2] is associated with poor cardiac function in heart failure patients. In animal models, GRK2 contributes to the pathogenesis of heart failure after ischemia-reperfusion (IR) injury. In addition to its role in down-regulating activated GPCRs, GRK2 also localizes to mitochondria both basally and post-IR injury, where it regulates cellular metabolism. We previously showed that phosphorylation of GRK2 at Ser⁶⁷⁰ is essential for the translocation of GRK2 to the mitochondria of cardiomyocytes post-IR injury in vitro and that this localization promotes cell death. Here, we showed that mice with a S670A knock-in mutation in endogenous GRK2 showed reduced cardiomyocyte death and better cardiac function post-IR injury. Cultured GRK2-S670A knock-in cardiomyocytes subjected to IR in vitro showed enhanced glucose-mediated mitochondrial respiratory function that was partially due to maintenance of pyruvate dehydrogenase activity and improved glucose oxidation. Thus, we propose that mitochondrial GRK2 plays a detrimental role in cardiac glucose oxidation post-injury.

Asymmetric dimethylarginine (ADMA) as an important risk factor for the increased cardiovascular diseases and heart failure in chronic kidney disease

Patients with chronic kidney disease have an increased cardiovascular morbidity and mortality. It has been recognized that the traditional cardiovascular risk factors could only partially explain the increased cardiovascular morbidity and mortality in patients with chronic kidney disease. Asymmetric dimethylarginine (ADMA) and N-monomethy l-arginine (L-NMMA) are endogenous inhibitors of nitric oxide synthases that attenuate nitric oxide production and enhance reactive oxidative specie generation. Increased plasma ADMA and/or L-NMMA are strong and independent risk factor for chronic kidney disease, and various cardiovascular diseases such as hypertension, coronary artery disease, atherosclerosis, diabetes, and heart failure. Both ADMA and L-NMMA are also eliminated from the body through either degradation by dimethylarginine dimethylaminohydrolase-1 (DDAH1) or urine excretion. This short review will exam the literature of ADMA and L-NMMA degradation and urine excretion, and the role of chronic kidney diseases in ADMA and L-NMMA accumulation and the increased cardiovascular disease risk. Based on all available data, it appears that the increased cardiovascular morbidity in chronic kidney disease may relate to the dramatic increase of systemic ADMA and L-NMMA after kidney failure.

Noncanonical Roles of G Protein-coupled Receptor Kinases in Cardiovascular Signaling

G protein-coupled receptor kinases (GRKs) are classically known for their role in regulating the activity of the largest known class of membrane receptors, which influence diverse biological processes in every cell type in the human body. As researchers have tried to uncover how this family of kinases, containing only 7 members, achieves selective and coordinated control of receptors, they have uncovered a growing number of noncanonical activities for these kinases. These activities include phosphorylation of nonreceptor targets and kinase-independent molecular interactions. In particular, GRK2, GRK3, and GRK5 are the predominant members expressed in the heart. Their canonical and noncanonical actions within cardiac and other tissues have significant implications for cardiovascular function in healthy animals and for the development and progression of disease. This review summarizes what is currently known regarding the activity of these kinases, and particularly the role of GRK2 and GRK5 in the molecular alterations that occur during heart failure. This review further highlights areas of GRK regulation that remain poorly understood and how they may represent novel targets for therapeutic development.

Nrf2 Deficiency Unmasks the Significance of Nitric Oxide Synthase Activity for Cardioprotection

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a key master switch that controls the expression of antioxidant and cytoprotective enzymes, including enzymes catalyzing glutathione de novo synthesis. In this study, we aimed to analyze whether Nrf2 deficiency influences antioxidative capacity, redox state, NO metabolites, and outcome of myocardial ischemia reperfusion (I/R) injury. In Nrf2 knockout (Nrf2 KO) mice, we found elevated eNOS expression and preserved NO metabolite concentrations in the aorta and heart as compared to wild types (WT). Unexpectedly, Nrf2 KO mice have a smaller infarct size following myocardial ischemia/reperfusion injury than WT mice and show fully preserved left ventricular systolic function. Inhibition of NO synthesis at onset of ischemia and during early reperfusion increased myocardial damage and systolic dysfunction in Nrf2 KO mice, but not in WT mice. Consistent with this, infarct size and diastolic function were unaffected in eNOS knockout (eNOS KO) mice after ischemia/reperfusion. Taken together, these data suggest that eNOS upregulation under conditions of decreased antioxidant capacity might play an important role in cardioprotection against I/R. Due to the redundancy in cytoprotective mechanisms, this fundamental antioxidant property of eNOS is not evident upon acute NOS inhibition in WT mice or in eNOS KO mice until Nrf2-related signaling is abrogated.