TMBIM6/BI-1 contributes to cancer progression through assembly with mTORC2 and AKT activation

TMBIM6/BI-1 is an intracellular environmental regulator that induces paraptosis in cancer via ROS and Calcium-activated ERAD II pathways

Transmembrane B cell lymphoma 2-associated X protein inhibitor motif-containing (TMBIM) 6, also known as Bax Inhibitor-1 (BI-1), has been heavily researched for its cytoprotective functions. TMBIM6 functional diversity includes modulating cell survival, stress, metabolism, cytoskeletal dynamics, organelle function, regulating cytosolic acidification, calcium, and reactive oxygen species (ROS). Clinical research shows TMBIM6 plays a key role in many of the world's top diseases/injuries (i.e., Alzheimer's, Parkinson's, diabetes, obesity, brain injury, liver disease, heart disease, aging, etc.), including cancer, where TMBIM6 expression impacts patient survival, chemoresistance, cancer progression, and metastasis. We show TMBIM6 is activated by, and undergoes, different conformational changes that dictate its function following a significant change in the cell's IntraCellular Environment (ICE). TMBIM6 agonism, following ICE change, can help the cell overcome multiple stresses including toxin exposure, viral infection, wound healing, and excitotoxicity. However, in cancer cells TMBIM6 agonism results in rapid paraptotic induction irrespective of the cancer type, sub-type, genotype or phenotype. Furthermore, the level of TMBIM6 expression in cancer did not dictate the level of paraptotic induction; however, it did dictate the rate at which paraptosis occurred. TMBIM6 agonism did not induce paraptosis in cancer via canonical routes involving p38 MAPK, JNK, ERK, UPR, autophagy, proteasomes, or Caspase-9. Instead, TMBIM6 agonism in cancer upregulates cytosolic Ca2+ and ROS, activates lysosome biogenesis, and induces paraptosis via ERAD II mechanisms. In xenograft models, we show TMBIM6 agonism induces rapid cancer cell death with no toxicity, even at high doses of TMBIM6 agonist (>450 mg/kg). In summary, this study shows TMBIM6's functional diversity is only activated by severe ICE change in diseased/injured cells, highlighting its transformative potential as a therapeutic target across various diseases and injuries, including cancer.

An updated systematic review about various effects of microplastics on cancer: A pharmacological and in-silico based analysis

Microplastics (MPs) are known as substantial environmental and health threats because of their pervasive existence and potential function in human diseases. This study is the first research in which a comprehensive analysis of various impacts of MPs on cancer cells is performed through pharmacological and in silico approaches. Moreover, our results demonstrate that MPs have both promotive and suppressive impacts on cancer cells, changing some of the important features of these kinds of cells including cellular viability, migration, metastasis, and apoptosis. Furthermore, the present study displayed that AP-2 complex subunit mu-1 (AP2M1), Asialoglycoprotein receptor 2 (ASGR2), Bax inhibitor-1 (BI-1), and Ferritin Heavy Chain, and pivotal role in the progression of cancers mediated by MPs. Moreover, our in-silico analysis identified Goserelin, Paclitaxel, Raloxifene, Exemestane, Epirubicin, Trametinib, Vemurafenib, Pactitaxel, and Sorafenib as potential anticancer agents for curing MPS-based cancer. Besides, our results demonstrated that MPs can exacerbate the development of tumor cells by affecting some important mechanisms including oxidative stress, immune suppression, and adjusting of critical signaling pathways. Interestingly, some sorts of MPs also displayed suppressive effects on cancer cells in some particular contexts, highlighting their complicated biological roles in different biological interactions. Ultimately the present survey tries to demonstrate the crucial roles of MPs in cancer cells and the different mechanisms that occur in the mentioned cells in order to emphasize performing more studies about clarifying the roles of MPs in carcinogenesis.

Deciphering the Function of lncRNA XIST/miR-329-3p/TMBIM6 Axis in the Proliferation of Non-Small Cell Lung Cancer

OBJECTIVE

Non-small cell lung cancer (NSCLC) remains a major health concern due to its high incidence and mortality rates. This study aimed to investigate the role and underlying mechanism of the long non-coding X inactivation-specific transcript (lncRNA XIST)/microRNA-329-3p (miR-329-3p)/transmembrane BAX Inhibitor Motif-6 (TMBIM6) axis in the proliferation, migration, and invasion of NSCLC, and its potential as a therapeutic target.

METHODS

The expression levels of XIST, miR-329-3p, and TMBIM6 in NSCLC tissues and cell lines were assessed using quantitative real-time PCR (qRT-PCR), and their correlations with clinicopathological characteristics were examined. Dual-luciferase reporter assays and RNA immunoprecipitation (RIP) were used to validate the binding interactions among XIST and miR-329-3p, and TMBIM6. The malignant phenotypes of NSCLC cells, including proliferation, migration, invasion, and apoptosis, were assessed using CCK-8, Transwell assays, and flow cytometry.

RESULTS

Silencing XIST significantly suppressed the proliferation, migration, and invasion of NSCLC cells while promoting apoptosis. Mechanistically, XIST functioned as a competitive endogenous RNA (ceRNA), sponging miR-329-3p and thereby downregulating its expression. Overexpression of miR-329-3p counteracted the oncogenic effects of XIST in NSCLC cells. Additionally, miR-329-3p downregulated TMBIM6 expression, while TMBIM6 overexpression counteracted the tumor-suppressive effects of miR-329-3p.

CONCLUSION

Silencing XIST upregulates miR-329-3p, leading to the suppression of TMBIM6 expression and inhibition of NSCLC progression. These findings suggest that the XIST/miR-329-3p/TMBIM6 axis could serve as a promising molecular target for therapeutic strategies in NSCLC.

GRINA alleviates hepatic ischemia‒reperfusion injury-induced apoptosis and ER-phagy by enhancing HRD1-mediated ATF6 ubiquitination

BACKGROUND & AIMS

Hepatic ischemia-reperfusion injury (HIRI) is a critical complication of liver surgery and transplantation that contributes significantly to severe organ failure. GRINA, a calcium-regulating endoplasmic reticulum (ER) protein, plays an essential role in controlling the unfolded protein response; however, its role in HIRI remains unclear. The aim of this study was to investigate the function of GRINA in HIRI and explore its potential as a therapeutic target.

METHODS

Liver tissues from patients undergoing hepatectomy, alongside a mouse model of partial HIRI, were used to assess GRINA expression levels. Hepatocyte-specific Grina knockout and transgenic mouse models were generated to explore the effects of GRINA on HIRI. Key markers of inflammation, apoptosis, ER stress, and autophagy were evaluated via real-time PCR, Western blotting, immunohistochemistry, immunofluorescence, and ELISA. RNA sequencing, mass spectrometry, coimmunoprecipitation and ubiquitination assays were used to elucidate the underlying molecular mechanisms.

RESULTS

GRINA expression was markedly reduced in hepatocytes from both patients and mice with HIRI, and its expression was inversely correlated with the severity of liver damage. Hepatocyte-specific Grina overexpression mitigated liver injury, the inflammatory response, and hepatocyte apoptosis following HIRI, whereas GRINA deficiency exacerbated these outcomes. Mechanistically, GRINA interacted directly with ATF6 and recruited HRD1 to form a multiprotein complex that catalyzed ATF6 polyubiquitination, thereby promoting its degradation. This process suppressed ER autophagy (ER-phagy), providing cellular protection following HIRI. The inhibition of ATF6 degradation attenuated the protective effects of GRINA in HIRI.

CONCLUSIONS

Our study highlights the critical role of the GRINA-HRD1-ATF6 complex in regulating ER stress and autophagy during HIRI. These findings provide new insights into therapeutic strategies to alleviate HIRI.

IMPACT AND IMPLICATIONS

Hepatic ischemia-reperfusion injury (HIRI) represents a multifaceted pathophysiological challenge commonly encountered during liver surgeries, yet its underlying molecular mechanisms remain inadequately understood. In this study, we revealed a significant negative correlation between GRINA levels and the severity of liver damage in patients with HIRI. Our findings demonstrate that GRINA alleviates endoplasmic reticulum stress by enhancing HRD1-mediated ubiquitination of ATF6, thereby maintaining calcium homeostasis and inhibiting ER-phagy. This study provides novel insights into the role of GRINA in protecting liver cells under HIRI, offering fresh perspectives for clinical prevention and management strategies for HIRI.

Halcinonide activates smoothened to ameliorate ischemic stroke injury

OBJECTIVES

The Shh pathway may shed new light on developing new cell death inhibitors for the therapy of ischemic stroke. We aimed to examine whether the Shh co-reporter SMO or its agonist halcinonide can upregulate Bcl-2 to suppress neuronal cell death, ultimately improving behavioral deficits and reducing cerebral infarction in an ischemic stroke model.

METHODS

Halcinonide or genetic manipulation of SMO was conducted in PC12 cells to examine their impacts on oxidative or OGD/R stress, and the chemical, along with AAV-SMO or AAV-EGFP were tested in MCAO rats to investigate their potential protective effects against neuronal damages due to cerebral I/R injury. The amounts or activities of L-LA, LDH, ROS, MDA, SOD, MPO, GSSG, and GSH were detected using the corresponding biochemical kits. The levels of TNF-α and IL-6 were analyzed by ELISA.

RESULTS

The results show that halcinonide alleviated neurological score and cerebral infarction, and the abnormal changes in L-LA, LDH, MDA, SOD, MPO, GSH, GSSG, TNF-α, and IL-6 were also reversed in MCAO rats. Through expression or knockout of SMO, we discovered that SMO worked similarly to halcinonide, protecting neuronal cells from oxidative or OGD/R stress, and AAV-SMO prevented cerebral damages of MCAO rats caused by ischemia and reperfusion. Halcinonide inhibited Bcl-2/Bax-mediated apoptosis, at least partially by promoting the Shh signaling pathway through enhancing SMO expression in vivo and in vitro.

CONCLUSION

This study identified a new target and a candidate chemical for therapy of ischemic stroke, hopefully reducing its morbidity and mortality.

The alarming link between environmental microplastics and health hazards with special emphasis on cancer

Microplastic contamination is a burgeoning environmental issue that poses serious threats to animal and human health. Microplastics enter the human body through nasal, dermal, and oral routes to contaminate multiple organs. Studies have advocated the existence of microplastics in human breast milk, sputum, faeces, and blood. Microplastics can find their ways to the sub-cellular moiety via active and passive approaches. At cellular level, microplastics follow clathrin and caveolae-dependent pathways to invade the sub-cellular environment. These environmental contaminants modulate the epigenetic control of gene expression, status of inflammatory mediators, redox homeostasis, cell-cycle proteins, and mimic the endocrine mediators like estrogen and androgen to fuel carcinogenesis. Furthermore, epidemiological studies have suggested potential links between the exposure to microplastics and the onset of various chronic diseases. Microplastics trigger uncontrolled cell proliferation and ensue tissue growth leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs. In essence, numerous reports have claimed microplastic-induced toxicity and tumorigenesis in human and model animals. Nonetheless, the underlying molecular mechanism is still elusive and warrants further investigations. This review provides a comprehensive analysis of microplastics, covering their sources, chemistry, human exposure routes, toxicity, and carcinogenic potential at the molecular level.

Long non-coding RNA TMEM147 antisense RNA 1/microRNA-124/signal transducer and activator of transcription 3 axis in estrogen receptor-positive breast cancer

OBJECTIVE

This research aimed to probe the expression of long noncoding RNA TMEM147 antisense RNA 1 (TMEM147-AS1)/micro-RNA (miR)-124/signal transducer and activator of transcription 3 (STAT3) axis in estrogen receptor (ER)-positive breast cancer (BC).

METHODS

Sixty ER-positive BC patients undergoing surgical treatment were gathered. TMEM147-AS1, miR-124, and STAT3 expression levels in BC cells and tissues were measured. The binding sites of TMEM147-AS1 and miR-124, miR-124, and STAT3 were analyzed and validated. The miR-124, STAT3 overexpression (oe) sequences, TMEM147-AS1 oe, and interference sequences and their control sequences were planned and cells were transfected to assess their functions in BC cells biological functions.

RESULTS

TMEM147-AS1, as well as STAT3 was extremely expressed and miR-124 was lowly expressed in BC cells and tissues. Interference with TMEM147-AS1 restrained ER-positive BC cell malignant activities. Mechanistically, TMEM147-AS1 could competitively bind miR-124 in refraining miR-124 expression, and STAT3 was a target gene of miR-124. Oe of miR-124 effectively reversed the enhancement of BC cell proliferation and invasion induced by TMEM147-AS1 upregulation. Oe of STAT3 could reverse the inhibitory effect of miR-124 on BC cell malignant behaviors.

CONCLUSION

TMEM147-AS1 has oncogenic activity in ER-positive BC, which may be a result of the altered miR-124/STAT3 axis. Therefore, targeting the TMEM147-AS1/miR-124/STAT3 axis may be a target for ER-positive BC therapy.

Zishenhuoxue decoction-induced myocardial protection against ischemic injury through TMBIM6-VDAC1-mediated regulation of calcium homeostasis and mitochondrial quality surveillance

BACKGROUND

Zishenhuoxue decoction (ZSHX), a Chinese herbal medicine, exhibits myocardial and vascular endothelial protective properties. The intricate regulatory mechanisms underlying myocardial ischemic injury and its association with dysfunctional mitochondrial quality surveillance (MQS) remain elusive.

HYPOTHESIS/PURPOSE

To study the protective effect of ZSHX on ischemic myocardial injury in mice using a TMBIM6 gene-modified animal model and mitochondrial quality control-related experiments.

STUDY DESIGN

Using model animals and myocardial infarction surgery-induced ischemic myocardial injury TMBIM6 gene-modified mouse models, the pharmacological activity of ZSHX in inhibiting ischemic myocardial injury and mitochondrial homeostasis disorder in vivo was tested.

METHODS

Our focal point entailed scrutinizing the impact of ZSHX on ischemic myocardial impairment through the prism of TMBIM6. This endeavor was undertaken utilizing mice characterized by heart-specific TMBIM6 knockout (TMBIM6CKO) and their counterparts, the TMBIM6 transgenic (TMBIM6TG) and VDAC1 transgenic (VDAC1TG) mice.

RESULTS

ZSHX demonstrated dose-dependent effectiveness in mitigating ischemic myocardial injury and enhancing mitochondrial integrity. TMBIM6CKO hindered ZSHX's cardio-therapeutic and mitochondrial protective effects, while ZSHX's benefits persisted in TMBIM6TG mice. TMBIM6CKO also blocked ZSHX's regulation of mitochondrial function in HR-treated cardiomyocytes. Hypoxia disrupted the MQS in cardiomyocytes, including calcium overload, excessive fission, mitophagy issues, and disrupted biosynthesis. ZSHX counteracted these effects, thereby normalizing MQS and inhibiting calcium overload and cardiomyocyte necroptosis. Our results also showed that hypoxia-induced TMBIM6 blockade resulted in the over-activation of VDAC1, a major mitochondrial calcium uptake pathway, while ZSHX could increase the expression of TMBIM6 and inhibit VDAC1-mediated calcium overload and MQS abnormalities.

CONCLUSIONS

Our findings suggest that ZSHX regulates mitochondrial calcium homeostasis and MQS abnormalities through a TMBIM6-VDAC1 interaction mechanism, which helps to treat ischemic myocardial injury and provides myocardial protection. This study also offers insights for the clinical translation and application of mitochondrial-targeted drugs in cardiomyocytess.

mTOR mutation disrupts larval zebrafish tail fin regeneration via regulating proliferation of blastema cells and mitochondrial functions

BACKGROUND

The larval zebrafish tail fin can completely regenerate in 3 days post amputation. mTOR, the main regulator of cell growth and metabolism, plays an essential role in regeneration. Lots of studies have documented the role of mTOR in regeneration. However, the mechanisms involved are still not fully elucidated.

MATERIALS AND RESULTS

This study aimed to explore the role and mechanism of mTOR in the regeneration of larval zebrafish tail fins. Initially, the spatial and temporal expression of mTOR signaling in the larval fin was examined, revealing its activation following tail fin amputation. Subsequently, a mTOR knockout (mTOR-KO) zebrafish line was created using CRISPR/Cas9 gene editing technology. The investigation demonstrated that mTOR depletion diminished the proliferative capacity of epithelial and mesenchymal cells during fin regeneration, with no discernible impact on cell apoptosis. Insight from SMART-seq analysis uncovered alterations in the cell cycle, mitochondrial functions and metabolic pathways when mTOR signaling was suppressed during fin regeneration. Furthermore, mTOR was confirmed to enhance mitochondrial functions and Ca2 + activation following fin amputation. These findings suggest a potential role for mTOR in promoting mitochondrial fission to facilitate tail fin regeneration.

CONCLUSION

In summary, our results demonstrated that mTOR played a key role in larval zebrafish tail fin regeneration, via promoting mitochondrial fission and proliferation of blastema cells.

13-oxyingenol dodecanoate derivatives induce mitophagy and ferroptosis through targeting TMBIM6 as potential anti-NSCLC agents

Ingenol diterpenoids continue to attract the attention for their extensive biological activity and novel structural features. To further explore this type of compound as anti-tumor agent, 13-oxyingenol dodecanoate (13-OD) was prepared by a standard chemical transformation from an Euphorbia kansui extract, and 29 derivatives were synthesized through parent 13-OD. Their inhibition activities against different types of cancer were screened and some derivatives showed superior anti-non-small cell lung cancer (NSCLC) cells cytotoxic potencies than oxaliplatin. In addition, TMBIM6 was identified as a crucial cellular target of 13-OD using ABPP target angling technique, and subsequently was verified by pull down, siRNA interference, BLI and CETSA assays. With modulating the function of TMBIM6 protein by 13-OD and its derivatives, Ca2+ release function was affected, causing mitochondrial Ca2+ overload, depolarisation of membrane potential. Remarkably, 13-OD, B6, A2, and A10-2 induced mitophagy and ferroptosis. In summary, our results reveal that 13-OD, B6, A2, and A10-2 holds great potential in developing anti-tumor agents for targeting TMBIM6.

LncRNA SNHG1 acts as a ceRNA for miR-216a-3p to regulate TMBIM6 expression in esophageal squamous cell carcinoma

Background: The long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been demonstrated to play a crucial role in the progression of esophageal squamous cell carcinoma (ESCC). The current study aims to explore the deeper molecular mechanisms of SNHG1 in ESCC. Methods: Fifty patients with ESCC were enrolled to assess overall survival. Quantitative real-time PCR was performed to measure the levels of SNHG1, miR-216a-3p, and TMBIM6 in ESCC cells. Functional assessments of SNHG1 on ESCC cells were conducted using CCK-8 assay, flow cytometry, and Transwell assays. Western blot was conducted to detect the protein levels of TMBIM6 and proapoptotic proteins (Calpain and Caspase-12). The interaction among SNHG1, miR-216a-3p, and TMBIM6 was assessed with luciferase reporter assays. Results: Our study revealed that SNHG1 was notably increased in both clinical ESCC samples and cellular lines. Upregulation of SNHG1 in ESCC tissues was indicative of poor overall survival. Functionally, SNHG1 knockdown significantly inhibited the proliferation, migration, and invasion while promoting apoptosis in ESCC cells. Mechanistically, SNHG1 functioned as a competing endogenous RNA by sequestering miR-216a-3p to modulate TMBIM6 levels in ESCC cells. Notably, inhibiting miR-216a-3p or restoring TMBIM6 reversed the inhibitory effect induced by SNHG1 knockdown in ESCC cells. Conclusions: We demonstrate for the first time that SNHG1 may act as a competing endogenous RNA and promote ESCC progression through the miR-216a-3p/TMBIM6 axis. This highlights the potential of SNHG1 as a target for ESCC treatment.

The mTORC2 signaling network: targets and cross-talks

The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.

TRPV4 enhances the synthesis of fatty acids to drive the progression of ovarian cancer through the calcium-mTORC1/SREBP1 signaling pathway

Transient receptor potential vanilloid 4 (TRPV4) is a nonselective cation channel activated by various stimuli, such as heat. A recent study reported that high expression of TRPV4 predicted a poor prognosis in ovarian cancer patients. This study demonstrated that TRPV4 was highly expressed in ovarian cancer and had the ability to promote proliferation and migration. Through RNA-seq and related experiments, we confirmed that the oncogenic pathway of TRPV4 in ovarian cancer may be related to the fatty acid synthesis. By correlation analysis and RNA-seq, we demonstrated that SREBP1 and mTORC1 were inseparably related to that. Therefore, we used inhibitors to perform experiments. Calcium fluorescent probe experiments suggest that the change of calcium content in ovarian cancer cells was related to the downstream mTORC1 signaling pathway and fatty acid synthesis. These results confirmed that TRPV4 affected the fatty acid synthesis through the calcium-mTOR/SREBP1 signaling pathway, thereby promoting ovarian cancer progression.

Exosomes-regulated lipid metabolism in tumorigenesis and cancer progression

Increasing evidence highlights the role of lipid metabolism in tumorigenesis and tumor progression. Targeting the processes of lipid metabolism, including lipogenesis, lipid uptake, fatty acid oxidation, and lipolysis, is an optimal strategy for anti-cancer therapy. Beyond cell-cell membrane surface interaction, exosomes are pivotal factors that transduce intercellular signals in the tumor microenvironment (TME). Most research focuses on the role of lipid metabolism in regulating exosome biogenesis and extracellular matrix (ECM) remodeling. The mechanisms of exosome and ECM-mediated reprogramming of lipid metabolism are currently unclear. We summarize several mechanisms associated with the regulation of lipid metabolism in cancer, including transport of exosomal carriers and membrane receptors, activation of the PI3K pathway, ECM ligand-receptor interactions, and mechanical stimulation. This review aims to highlight the significance of these intercellular factors in TME and to deepen the understanding of the functions of exosomes and ECM in the regulation of lipid metabolism.

PI3K/Akt signaling in urological cancers: Tumorigenesis function, therapeutic potential, and therapy response regulation

In addition to environmental conditions, lifestyle factors, and chemical exposure, aberrant gene expression and mutations involve in the beginning and development of urological tumors. Even in Western nations, urological malignancies are among the top causes of patient death, and their prevalence appears to be gender dependent. The prognosis for individuals with urological malignancies remains dismal and unfavorable due to the ineffectiveness of conventional treatment methods. PI3K/Akt is a popular biochemical mechanism that is activated in tumor cells as a result of PTEN loss. PI3K/Akt escalates growth and metastasis. Moreover, due to the increase in tumor cell viability caused by PI3K/Akt activation, cancer cells may acquire resistance to treatment. This review article examines the function of PI3K/Akt in major urological tumors including bladder, prostate, and renal tumors. In prostate, bladder, and kidney tumors, the level of PI3K and Akt are notably elevated. In addition, the activation of PI3K/Akt enhances the levels of Bcl-2 and XIAP, hence increasing the tumor cell survival rate. PI3K/Akt ] upregulates EMT pathways and matrix metalloproteinase expression to increase urological cancer metastasis. Furthermore, stimulation of PI3K/Akt results in drug- and radio-resistant cancers, but its suppression by anti-tumor drugs impedes the tumorigenesis.

LncRNA-HOTAIRM1 promotes aerobic glycolysis and proliferation in osteosarcoma via the miR-664b-3p/Rheb/mTOR pathway

Osteosarcoma (OS), which is a common and aggressive primary bone malignancy, occurs mainly in children and adolescent. Long noncoding RNAs (lncRNAs) are reported to play a pivotal role in various cancers. Here, we found that the lncRNA HOTAIRM1 is upregulated in OS cells and tissues. A set of functional experiments suggested that HOTAIRM1 knockdown attenuated the proliferation and stimulated the apoptosis of OS cells. A subsequent mechanistic study revealed that HOTAIRM1 functions as a competing endogenous RNA to elevate ras homologue enriched in brain (Rheb) expression by sponging miR-664b-3p. Immediately afterward, upregulated Rheb facilitates proliferation and suppresses apoptosis by promoting the mTOR pathway-mediated Warburg effect in OS. In summary, our findings demonstrated that HOTAIRM1 promotes the proliferation and suppresses the apoptosis of OS cells by enhancing the Warburg effect via the miR-664b-3p/Rheb/mTOR axis. Understanding the underlying mechanisms and targeting the HOTAIRM1/miR-664b-3p/Rheb/mTOR axis are essential for OS clinical treatment.

Pharmacological inhibition of bromodomain and extra-terminal proteins induces an NRF-2-mediated antiviral state that is subverted by SARS-CoV-2 infection

Inhibitors of bromodomain and extra-terminal proteins (iBETs), including JQ-1, have been suggested as potential prophylactics against SARS-CoV-2 infection. However, molecular mechanisms underlying JQ-1-mediated antiviral activity and its susceptibility to viral subversion remain incompletely understood. Pretreatment of cells with iBETs inhibited infection by SARS-CoV-2 variants and SARS-CoV, but not MERS-CoV. The antiviral activity manifested itself by reduced reporter expression of recombinant viruses, and reduced viral RNA quantities and infectious titers in the culture supernatant. While we confirmed JQ-1-mediated downregulation of expression of angiotensin-converting enzyme 2 (ACE2) and interferon-stimulated genes (ISGs), multi-omics analysis addressing the chromatin accessibility, transcriptome and proteome uncovered induction of an antiviral nuclear factor erythroid 2-related factor 2 (NRF-2)-mediated cytoprotective response as an additional mechanism through which JQ-1 inhibits SARS-CoV-2 replication. Pharmacological inhibition of NRF-2, and knockdown of NRF-2 and its target genes reduced JQ-1-mediated inhibition of SARS-CoV-2 replication. Serial passaging of SARS-CoV-2 in the presence of JQ-1 resulted in predominance of ORF6-deficient variant, which exhibited resistance to JQ-1 and increased sensitivity to exogenously administered type I interferon (IFN-I), suggesting a minimised need for SARS-CoV-2 ORF6-mediated repression of IFN signalling in the presence of JQ-1. Importantly, JQ-1 exhibited a transient antiviral activity when administered prophylactically in human airway bronchial epithelial cells (hBAECs), which was gradually subverted by SARS-CoV-2, and no antiviral activity when administered therapeutically following an established infection. We propose that JQ-1 exerts pleiotropic effects that collectively induce an antiviral state in the host, which is ultimately nullified by SARS-CoV-2 infection, raising questions about the clinical suitability of the iBETs in the context of COVID-19.

Construction of a Matrix Cancer-Associated Fibroblast Signature Gene-Based Risk Prognostic Signature for Directing Immunotherapy in Patients with Breast Cancer Using Single-Cell Analysis and Machine Learning

Cancer-associated fibroblasts (CAFs) are heterogeneous constituents of the tumor microenvironment involved in the tumorigenesis, progression, and therapeutic responses of tumors. This study identified four distinct CAF subtypes of breast cancer (BRCA) using single-cell RNA sequencing (RNA-seq) data. Of these, matrix CAFs (mCAFs) were significantly associated with tumor matrix remodeling and strongly correlated with the transforming growth factor (TGF)-β signaling pathway. Consensus clustering of The Cancer Genome Atlas (TCGA) BRCA dataset using mCAF single-cell characteristic gene signatures segregated samples into high-fibrotic and low-fibrotic groups. Patients in the high-fibrotic group exhibited a significantly poor prognosis. A weighted gene co-expression network analysis and univariate Cox analysis of bulk RNA-seq data revealed 17 differential genes with prognostic values. The mCAF risk prognosis signature (mRPS) was developed using 10 machine learning algorithms. The clinical outcome predictive accuracy of the mRPS was higher than that of the conventional TNM staging system. mRPS was correlated with the infiltration level of anti-tumor effector immune cells. Based on consensus prognostic genes, BRCA samples were classified into the following two subtypes using six machine learning algorithms (accuracy > 90%): interferon (IFN)-γ-dominant (immune C2) and TGF-β-dominant (immune C6) subtypes. Patients with mRPS downregulation were associated with improved prognosis, suggesting that they can potentially benefit from immunotherapy. Thus, the mRPS model can stably predict BRCA prognosis, reflect the local immune status of the tumor, and aid clinical decisions on tumor immunotherapy.

TMBIM6 deficiency leads to bone loss by accelerating osteoclastogenesis

TMBIM6 is an endoplasmic reticulum (ER) protein that modulates various physiological and pathological processes, including metabolism and cancer. However, its involvement in bone remodeling has not been investigated. In this study, we demonstrate that TMBIM6 serves as a crucial negative regulator of osteoclast differentiation, a process essential for bone remodeling. Our investigation of Tmbim6-knockout mice revealed an osteoporotic phenotype, and knockdown of Tmbim6 inhibited the formation of multinucleated tartrate-resistant acid phosphatase-positive cells, which are characteristic of osteoclasts. Transcriptome and immunoblot analyses uncovered that TMBIM6 exerts its inhibitory effect on osteoclastogenesis by scavenging reactive oxygen species and preventing p65 nuclear localization. Additionally, TMBIM6 depletion was found to promote p65 localization to osteoclast-related gene promoters. Notably, treatment with N-acetyl cysteine, an antioxidant, impeded the osteoclastogenesis induced by TMBIM6-depleted cells, supporting the role of TMBIM6 in redox regulation. Furthermore, we discovered that TMBIM6 controls redox regulation via NRF2 signaling pathways. Our findings establish TMBIM6 as a critical regulator of osteoclastogenesis and suggest its potential as a therapeutic target for the treatment of osteoporosis.

Polypropylene microplastics promote metastatic features in human breast cancer

Microplastics (MPs) are now a global issue due to increased plastic production and use. Recently, various studies have been performed in response to the human health risk assessment. However, these studies have focused on spherical MPs, which have smooth edges and a spherical shape and account for less than 1% of MPs in nature. Unfortunately, studies on fragment-type MPs are very limited and remain in the initial stages. In this study, we studied the effect that 16.4 µm fragment type polypropylene (PP) MPs, which have an irregular shape and sharp edges and form naturally in the environment, had on breast cancer. The detrimental effects of PPMPs on breast cancer metastasis were examined. Here, 1.6 mg/ml of PPMP, which does not induce cytotoxicity in MDA-MB-231, was used, and at this concentration, PPMP did not induce morphological changes or cellular migrating in the MDA-MB-231 and MCF-7 cells. However, PPMP incubation for 24 hours in the MDA-MB-231 cells significantly altered the level of cell cycle-related transcripts in an RNA-seq analysis. When confirmed by qRT-PCR, the gene expression of TMBIM6, AP2M1, and PTP4A2 was increased, while the transcript level of FTH1 was decreased. Further, secretion of the pro-inflammatory cytokine IL-6 from cancer cells was elevated with the incubation of PPMP for 12 hours. These results suggest that PPMP enhances metastasis-related gene expression and cytokines in breast cancer cells, exacerbating breast cancer metastasis.

A gating mechanism of the BsYetJ calcium channel revealed in an endoplasmic reticulum lipid environment

The transmembrane BAX inhibitor-1-containing motif 6 (TMBIM6) is suggested to modulate apoptosis by regulating calcium homeostasis in the endoplasmic reticulum (ER). However, the precise molecular mechanism underlying this calcium regulation remains poorly understood. To shed light on this issue, we investigated all negatively charged residues in BsYetJ, a bacterial homolog of TMBIM6, using mutagenesis and fluorescence-based functional assays. We reconstituted BsYetJ in membrane vesicles with a lipid composition similar to that of the ER. Our results show that the charged residues E49 and R205 work together as a major gate, regulating calcium conductance in these ER-like lipid vesicles. However, these residues become largely inactive when reconstituted in other lipid environments. In addition, we found that D195 acts as a minor filter compared to the E49-R205 dyad. Our study uncovers a previously unknown function of BsYetJ/TMBIM6 in the calcium-dependent inactivation of BsYetJ, providing a framework for the development of a lipid-dependent mechanistic model of BsYetJ that will facilitate our understanding of calcium-dependent apoptosis.

TMBIM6 prevents VDAC1 multimerization and improves mitochondrial quality control to reduce sepsis-related myocardial injury

BACKGROUND

The regulatory mechanisms involved in mitochondrial quality control (MQC) dysfunction during septic cardiomyopathy (SCM) remain incompletely characterized. Transmembrane BAX inhibitor motif containing 6 (TMBIM6) is an endoplasmic reticulum protein with Ca²⁺ leak activity that modulates cellular responses to various cellular stressors.

METHODS

In this study, we evaluated the role of TMBIM6 in SCM using cardiomyocyte-specific TMBIM6 knockout (TMBIM6^CKO) and TMBIM6 transgenic (TMBIM6^TG) mice.

RESULTS

Myocardial TMBIM6 transcription and expression were significantly downregulated in wild-type mice upon LPS exposure, along with characteristic alterations in myocardial systolic/diastolic function, cardiac inflammation, and cardiomyocyte death. Notably, these alterations were further exacerbated in LPS-treated TMBIM6^CKO mice, and largely absent in TMBIM6^TG mice. In LPS-treated primary cardiomyocytes, TMBIM6 deficiency further impaired mitochondrial respiration and ATP production, while defective MQC was suggested by enhanced mitochondrial fission, impaired mitophagy, and disrupted mitochondrial biogenesis. Structural protein analysis, Co-IP, mutant TMBIM6 plasmid transfection, and molecular docking assays subsequently indicated that TMBIM6 exerts cardioprotection against LPS-induced sepsis by interacting with and preventing the oligomerization of voltage-dependent anion channel-1 (VDAC1), the major route of mitochondrial Ca²⁺ uptake.

CONCLUSION

We conclude that the TMBIM6-VDAC1 interaction prevents VDAC1 oligomerization and thus sustains mitochondrial Ca²⁺ homeostasis as well as MQC, contributing to improved myocardial function in SCM.

New Insights into the Regulation of mTOR Signaling via Ca2+-Binding Proteins

Environmental factors are important regulators of cell growth and proliferation. Mechanistic target of rapamycin (mTOR) is a central kinase that maintains cellular homeostasis in response to a variety of extracellular and intracellular inputs. Dysregulation of mTOR signaling is associated with many diseases, including diabetes and cancer. Calcium ion (Ca²⁺) is important as a second messenger in various biological processes, and its intracellular concentration is tightly regulated. Although the involvement of Ca²⁺ mobilization in mTOR signaling has been reported, the detailed molecular mechanisms by which mTOR signaling is regulated are not fully understood. The link between Ca²⁺ homeostasis and mTOR activation in pathological hypertrophy has heightened the importance in understanding Ca²⁺-regulated mTOR signaling as a key mechanism of mTOR regulation. In this review, we introduce recent findings on the molecular mechanisms of regulation of mTOR signaling by Ca²⁺-binding proteins, particularly calmodulin (CaM).

STRIP2 motivates non-small cell lung cancer progression by modulating the TMBIM6 stability through IGF2BP3 dependent

BACKGROUND

Striatin interacting protein 2 (STRIP2) is a core component of the striatin-interacting phosphatase and kinase (STRIPAK) complexes, which is involved in tumor initiation and progression via the regulation of cell contractile and metastasis. However, the underlying molecular mechanisms of STRIP2 in non-small cell lung cancer (NSCLC) progression remain largely unknown.

METHODS

The expressions of STRIP2 and IGF2BP3 in human NSCLC specimens and NSCLC cell lines were detected using quantitative RT-PCR, western blotting, and immunohistochemistry (IHC) analyses. The roles and molecular mechanisms of STRIP2 in promoting NSCLC progression were investigated in vitro and in vivo.

RESULTS

Here, we found that STRIP2 expression was significantly elevated in NSCLC tissues and high STRIP2 expression was associated with a poor prognosis. Knockdown of STRIP2 suppressed tumor growth and metastasis in vitro and in vivo, while STRIP2 overexpression obtained the opposite effect. Mechanistically, P300/CBP-mediated H3K27 acetylation activation in the promoter of STRIP2 induced STRIP2 transcription, which interacted with insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) and upregulated IGF2BP3 transcription. In addition, STRIP2-IGF2BP3 axis stimulated m6A modification of TMBIM6 mRNA and enhanced TMBIM6 stability. Consequently, TMBIM6 involved NSCLC cell proliferation, migration and invasion dependent on STRIP2 and IGF2BP3. In NSCLC patients, high co-expression of STRIP2, IGF2BP3 and TMBIM6 was associated with poor outcomes.

CONCLUSIONS

Our findings indicate that STRIP2 interacts with IGF2BP3 to regulate TMBIM6 mRNA stability in an m6A-dependent manner and may represent a potential prognostic biomarker and therapeutic target for NSCLC.

Primaquine activates Keratin 7 to treat diabetes and its complications

Background

The global prevalence of type 2 diabetes mellitus (T2DM) raises the rates of its complications, such as diabetic nephropathy and cardiovascular diseases. To conquer the complications, new strategies to reverse the deterioration of T2DM are urgently needed. In this project, we aimed to examine the hypoglycemic effect of primaquine and explore its specific target.

Methods

In vitro T2DM insulin resistance model was built in HepG2 cells to screen the potential anti-diabetic chemicals. On the other hand, the potential protein targets were explored by molecular docking. Accordingly, we chose C57BL/6 N mice to establish T2DM model to verify the effect of the chemicals on anti-hyperglycemia and diabetic complications.

Results

By targeting the Keratin 7 (K7) to activate EGFR/Akt glucose metabolism signaling pathway, primaquine poses a potent hypoglycemic effect. The level of acetyl-CoA is enhanced markedly, supporting that primaquine upregulates the aerobic glycolysis. Moreover, primaquine ameliorates kidney function by reducing the secretion of urinary proteins and creatinine, especially for the urea nitrogen which is significantly decreased compared to no-treatment T2DM mice. Notably, primaquine restores the level of plasma low-density lipoprotein cholesterol (LDL-C) nearly to normal, minimizing the incidence of cardiovascular diseases.

Conclusions

We find that primaquine may reverse the dysregulated metabolism to prevent diabetic complications by stimulating EGFR/Akt signaling axis, shedding new light on the therapy of T2DM.

Graphical abstract

Insulin resistance is characterized by reduced p-Akt and glucose metabolism, dominated by anaerobic glycolysis. Primaquine activates the complex made of K7 and EGFR, further stimulating Akt phosphorylation. Then, p-Akt promotes the aerobic glucose metabolism and upregulates Ac-CoA to mobilize TCA cycle, improving insulin sensitivity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01135-8.

Energy metabolism pathways in breast cancer progression: The reprogramming, crosstalk, and potential therapeutic targets

Breast cancer (BC) is a malignant tumor that seriously endangers health in women. BC, like other cancers, is accompanied by metabolic reprogramming. Among energy metabolism-related pathways, BC exhibits enhanced glycolysis, tricarboxylic acid (TCA) cycle, pentose phosphate pathway (PPP), glutamate metabolism, and fatty acid metabolism activities. These pathways facilitate the proliferation, growth and migration of BC cells. The progression of BC is closely related to the alterations in the activity or expression level of several metabolic enzymes, which are regulated by the intrinsic factors such as the key signaling and transcription factors. The metabolic reprogramming in the progression of BC is attributed to the aberrant expression of the signaling and transcription factors associated with the energy metabolism pathways. Understanding the metabolic mechanisms underlying the development of BC will provide a druggable potential for BC treatment and drug discovery.

Epstein-Barr Virus-Encoded MicroRNA-BART18-3p Promotes Colorectal Cancer Progression by Targeting De Novo Lipogenesis

The Epstein-Barr virus (EBV) genome encodes a cluster of 22 viral microRNAs, called miR-BamHI-A rightward transcripts (miR-BARTs), which are shown to promote the development of cancer. Here, this study reports that EBV-miR-BART18-3p is highly expressed in colorectal cancer (CRC) and is closely associated with the pathological and advanced clinical stages of CRC. Ectopic expression of EBV-miR-BART18-3p leads to increased migration and invasion capacities of CRC cells in vitro and causes tumor metastasis in vivo. Mechanistically, EBV-miR-BART18-3p activates the hypoxia inducible factor 1 subunit alpha/lactate dehydrogenase A axis by targeting Sirtuin, which promotes lactate accumulation and acetyl-CoA production in CRC cells under hypoxic condition. Increased acetyl-CoA utilization subsequently leads to histone acetylation of fatty acid synthase and fatty acid synthase-dependent fat synthesis, which in turn drives de novo lipogenesis. The oncogenic role of EBV-miR-BART18-3p is confirmed in the patient-derived tumor xenograft mouse model. Altogether, the findings define a novel mechanism of EBV-miR-BART18-3p in CRC development through the lipogenesis pathway and provide a potential clinical intervention target for CRC.

Canonical and Noncanonical ER Stress-Mediated Autophagy Is a Bite the Bullet in View of Cancer Therapy

Cancer cells adapt multiple mechanisms to counter intense stress on their way to growth. Tumor microenvironment stress leads to canonical and noncanonical endoplasmic stress (ER) responses, which mediate autophagy and are engaged during proteotoxic challenges to clear unfolded or misfolded proteins and damaged organelles to mitigate stress. In these conditions, autophagy functions as a cytoprotective mechanism in which malignant tumor cells reuse degraded materials to generate energy under adverse growing conditions. However, cellular protection by autophagy is thought to be complicated, contentious, and context-dependent; the stress response to autophagy is suggested to support tumorigenesis and drug resistance, which must be adequately addressed. This review describes significant findings that suggest accelerated autophagy in cancer, a novel obstacle for anticancer therapy, and discusses the UPR components that have been suggested to be untreatable. Thus, addressing the UPR or noncanonical ER stress components is the most effective approach to suppressing cytoprotective autophagy for better and more effective cancer treatment.

Assessment of spatial transcriptomics for oncology discovery

Tumor heterogeneity is a major challenge for oncology drug discovery and development. Understanding of the spatial tumor landscape is key to identifying new targets and impactful model systems. Here, we test the utility of spatial transcriptomics (ST) for oncology discovery by profiling 40 tissue sections and 80,024 capture spots across a diverse set of tissue types, sample formats, and RNA capture chemistries. We verify the accuracy and fidelity of ST by leveraging matched pathology analysis, which provides a ground truth for tissue section composition. We then use spatial data to demonstrate the capture of key tumor depth features, identifying hypoxia, necrosis, vasculature, and extracellular matrix variation. We also leverage spatial context to identify relative cell-type locations showing the anti-correlation of tumor and immune cells in syngeneic cancer models. Lastly, we demonstrate target identification approaches in clinical pancreatic adenocarcinoma samples, highlighting tumor intrinsic biomarkers and paracrine signaling.

Identification of Calcium Channel-Related Gene P2RX2 for Prognosis and Immune Infiltration in Prostate Cancer

Prostate cancer is one of the most common malignancies in men. Calcium signaling is implicated in the progression of prostate cancer and plays a critical role in immune cell function. However, whether specific calcium channel-related genes play a crucial role in the immune cell infiltration levels of prostate cancer requires further research. In this study, we performed an integrated analysis of transcriptional, clinical, and somatic mutation data from The Cancer Genome Atlas database and identified the hub calcium channel-related gene P2RX2 to be associated with the prognosis and immune infiltration of prostate cancer. P2RX2 expression was positively correlated with immune cell infiltration levels and the expression of immune checkpoint genes, and downregulation of P2RX2 led to poor survival in patients with prostate cancer. Furthermore, we validated the molecular and clinical characteristics of P2RX2 by using multiple databases and conducting in-vitro experiments. Additionally, drug sensitivity analysis revealed that patients with low P2RX2 expression were sensitive to docetaxel and Bicalutamide. In conclusion, we revealed an association between calcium channel-related genes and prostate cancer, and identified P2RX2 as a biomarker for early diagnosis, prognosis prediction, and aiding treatment decisions for patients with prostate cancer.

Drug-loaded oleic-acid grafted mesoporous silica nanoparticles conjugated with α-lactalbumin resembling BAMLET-like anticancer agent with improved biocompatibility and therapeutic efficacy

Despite its prominent therapeutic efficacy, chemotherapy has raised serious concerns due to the severe adverse effects and multidrug resistance evoked, which propels the search for safe and green therapeutic agents. BAMLET (bovine α-lactalbumin made lethal against tumor cell) is a well-known protein-based anticancer agent of selective tumoricidal activity. Here, we prepared oleic acid-modified mesoporous silica nanoparticles (OA-MSNs) conjugated with bovine α-lactalbumin, a lipoprotein complex resembling BAMLET formed on the surface of MSNs (MSN-BAMLET) to load the anticancer drug of docetaxel (DTX). Compared to that of OA-MSNs/DTX, the obtained MSN-BAMLET/DTX with a sustained and pH-responsive drug release behaviors exhibited good biocompatibility and enhanced cytotoxic effect against cancer cells. Moreover, the presence of lipoprotein complex in MSN-BAMLET contributed to the improved dispersion of the composite in solution and the inhibitory effect on the migration of cancer cells. Furthermore, the adsorption profiles of protein corona on the obtained nanoparticles were analyzed. It was found that the marked low amount and abundance of plasma proteins were adsorbed on the α-lactalbumin coated siliceous composite demonstrated its long circulation property. Finally, in vivo study showed that MSN-BAMLET/DTX contributed to the effective cancer ablation and the prolonged survival. Therefore, the constructed MSN-BAMLET of the mesoregular structure and peculiar tumoricidal effect provides a manipulable nanoplatform as drug nanocarrier for therapeutic applications.

The biochemical and clinical implications of phosphatase and tensin homolog deleted on chromosome ten in different cancers

Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is widely known as a tumor suppressor gene. It is located on chromosome 10q23 with 200 kb, and has dual activity of both protein and lipid phosphatase. In addition, as a targeted gene in multiple pathways, PTEN has a variety of physiological activities, such as those regulating the cell cycle, inducing cell apoptosis, and inhibiting cell invasion, etc. The PTEN gene have been identified in many kinds of cancers due to its mutations, deletions and inactivation, such as lung cancer, liver cancer, and breast cancer, and they are closely connected with the genesis and progression of cancers. To a large extent, the tumor suppressive function of PTEN is realized through its inhibition of the PI3K/AKT signaling pathway which controls cells apoptosis and development. In addition, PTEN loss has been associated with the prognosis of many cancers, such as lung cancer, liver cancer, and breast cancer. PTEN gene is related to many cancers and their pathological development. On the basis of a large number of related studies, this study describes in detail the structure, regulation, function and classical signal pathways of PTEN, as well as the relationship between various tumors related to PTEN. In addition, some drug studies targeting PTEN/PI3K/AKT/mTOR are also introduced in order to provide some directions for experimental research and clinical treatment of tumors.

Morin Acts as a USP7 Inhibitor to Hold Back the Migration of Rheumatoid Arthritis Fibroblast-Like Synoviocytes in a "Prickle1-mTORC2" Dependent Manner

INTRODUCTION

The aim of this study is to investigate the effect and detailed mechanisms of morin, an anti-arthritis compound widely distributed in foods of plant origin, on the pathological migration of fibroblast-like synoviocytes (FLS).

METHODS AND RESULTS

The migration of FLS collected from arthritis rats and MH7A cells is induced by platelet-derived growth factor, and an arthritis model in rats is established by Freund's complete adjuvant. The results show that morin remarkably restrains FLS migration but slightly affects FLS apoptosis and proliferation. Moreover, in the progression of FLS migration, focal adhesion (FA) turnover is inhibited by morin via lowering the activation of Paxillin and focal adhesion kinase (FAK) and internalization of integrin β1. Morin disrupts the formation of mTOR complex 2 (mTORC2) and the activation of AKT (S473) and PKCα (S657), and MHY1485 reverses morin-limited FLS migration. Of note, the protein stability of Prickle1, a binding factor of Rictor, is reduced by morin, and MG132 but not Baf A1 shows a repressive effect. Finally, the target protein is identified as ubiquitin-specific protease 7 (USP7) but not USP9X. USP7 overexpressing plasmid weakens morin-affected protein and ubiquitination of Prickle1, and mechanisms are confirmed in vivo by using an overexpressing plasmid and inhibitor.

CONCLUSION

Morin restricts FLS migration and arthritis by intervening in "USP7-Prickle1-mTORC2" signaling and FA turnover.

TMBIM6 regulates redox-associated posttranslational modifications of IRE1α and ER stress response failure in aging mice and humans

Age-associated persistent ER stress is the result of declining chaperone systems of the ER that reduces cellular functions, induces apoptosis, and leads to age-related diseases. This study investigated the previously unknown regulatory mechanism of TMBIM6 during age-associated hepatic abnormalities. Wild-type (WT) and the TMBIM6 knockout (TMBIM6^−/−) mice liver, human liver samples from different age groups were used to demonstrate the effect of physiological aging on liver. For TMBIM6 rescue experiments, TMBIM6^−/− old mice and stable human hepatic cell lines expressing TMBIM 6 were used to study the functional role of TMBIM6 on aging-associated steatosis and its associated mechanisms. In aging humans and mice, we observed declined expression of TMBIM6 and aberrant UPR expression, which were associated with high hepatic lipid accumulation. During aging, TMBIM6-deficient mice had increased senescence than their WT counterparts. We identified redox-mediated posttranslational modifications of IRE1α such as S-nitrosylation and sulfonation were higher in TMBIM6-deficient aging mice and humans, which impaired the ER stress response signaling. Sulfonation of IRE1α enhanced regulated IRE1α-dependent decay (RIDD) activity inducing TMBIM6 decay, whereas S-nitrosylation of IRE1α inhibited XBP1 splicing enhancing the cell death. Moreover, the degradation of miR-338-3p by strong IRE1α cleavage activity enhanced the expression of PTP1B, resulting in diminishing phosphorylation of PERK. The re-expression of TMBIM6 reduced IRE1α modifications, preserved ER homeostasis, reduced senescence and senescence-associated lipid accumulation in human hepatic cells and TMBIM6-depleted mice. S-nitrosylation or sulfonation of IRE1α and its controller, the TMBIM6, might be the potential therapeutic targets for maintaining ER homeostasis in aging and aging-associated liver diseases.

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TMBIM6 is downregulated in fatty degeneration, and in aging human and mouse liver.

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TMBIM6 deficiency induces ER stress response failure and cell death and increases age-associated steatosis.

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TMBIM6 regulates redox-mediated cysteine modifications such as S-nitrosylation and sulfonation of IRE1α.

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IRE1α-SNO inhibits XBP1 splicing, whereas IRE1α-SO₃H enhances RIDD activity inducing TMBIM6 decay.

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TMBIM6 overexpression attenuates hepatic steatosis by regulating ER stress and cysteine modifications caused by aging.

A Novel Risk Factor Model Based on Glycolysis-Associated Genes for Predicting the Prognosis of Patients With Prostate Cancer

BACKGROUND

Prostate cancer (PCa) is one of the most prevalent cancers among males, and its mortality rate is increasing due to biochemical recurrence (BCR). Glycolysis has been proven to play an important regulatory role in tumorigenesis. Although several key regulators or predictors involved in PCa progression have been found, the relationship between glycolysis and PCa is unclear; we aimed to develop a novel glycolysis-associated multifactor prediction model for better predicting the prognosis of PCa.

METHODS

Differential mRNA expression profiles derived from the Cancer Genome Atlas (TCGA) PCa cohort were generated through the "edgeR" package. Glycolysis-related genes were obtained from the GSEA database. Univariate Cox and LASSO regression analyses were used to identify genes significantly associated with disease-free survival. ROC curves were applied to evaluate the predictive value of the model. An external dataset derived from Gene Expression Omnibus (GEO) was used to verify the predictive ability. Glucose consumption and lactic production assays were used to assess changes in metabolic capacity, and Transwell assays were used to assess the invasion and migration of PC3 cells.

RESULTS

Five glycolysis-related genes were applied to construct a risk score prediction model. Patients with PCa derived from TCGA and GEO (GSE70770) were divided into high-risk and low-risk groups according to the median. In the TCGA cohort, the high-risk group had a poorer prognosis than the low-risk group, and the results were further verified in the GSE70770 cohort. In vitro experiments demonstrated that knocking down HMMR, KIF20A, PGM2L1, and ANKZF1 separately led to less glucose consumption, less lactic production, and inhibition of cell migration and invasion, and the results were the opposite with GPR87 knockdown.

CONCLUSION

The risk score based on five glycolysis-related genes may serve as an accurate prognostic marker for PCa patients with BCR.

Helicobacter urease suppresses cytotoxic CD8 + T cell responses through activating Myh9-dependent induction of PD-L1

As a key virulence factor for persistent colonization, Urease B subunit (UreB) is considered to be an ideal vaccine antigen against Helicobacter pylori (H. pylori) infection. However, the role and molecular mechanisms of UreB involved in immune microenvironment dysregulation still remains largely unknown. In the present study, we evaluated the effects of UreB on macrophage activation and found that UreB induced PD-L1 accumulation on Bone marrow-derived macrophages (BMDMs). Co-culture assays further revealed that UreB-induced PD-L1 expression on BMDMs significantly decreased the proliferation and secretion of cytolytic molecules (granzyme B and perforin) of splenic CD8 + T cells isolated from inactivated H. pylori-immunized mice. More importantly, myosin heavy chain 9 (Myh9) was confirmed to be a direct membrane receptor of UreB via using LC-MS/MS and Co-immunoprecipitation and required for PD-L1 upregulation on BMDMs. Molecular studies further demonstrated that the interaction between UreB and Myh9 decreased GCN2 autophosphorylation and enhanced intracellular pool of amino acids, leading to the upregulation of S6K phosphorylation, a commonly used marker for monitoring activation of mTORC1 signaling activity. Furthermore, blocking mTORC1 activation with its inhibitor Temsirolimus reversed UreB-induced PD-L1 upregulation and the subsequently inhibitory effects of BMDMs on activation of cytotoxic CD8 + T cell responses. Overall, our data unveil a novel immunosuppressive mechanism of UreB during H. pylori infection, which may provide valuable clue for the optimization of H. pylori vaccine.

Downregulation of ATXN3 Enhances the Sensitivity to AKT Inhibitors (Perifosine or MK-2206), but Decreases the Sensitivity to Chemotherapeutic Drugs (Etoposide or Cisplatin) in Neuroblastoma Cells

Background

Chemotherapy resistance is the major cause of failure in neuroblastoma (NB) treatment. ATXN3 has been linked to various types of cancer and neurodegenerative diseases; however, its roles in NB have not been established. The aim of our study was to explore the role of ATXN3 in the cell death induced by AKT inhibitor (perifosine or MK-2206) or chemotherapy drugs (etoposide or cisplatin) in NB cells.

Methods

The expressions of ATXN3 and BCL-2 family members were detected by Western blot. Cell survival was evaluated by CCK8, cell confluence was measured by IncuCyte, and apoptosis was detected by flow cytometry. AS and BE2 were treated with AKT inhibitors or chemotherapeutics, respectively.

Results

Downregulation of ATXN3 did not block, but significantly increased the perifosine/MK-2206-induced cell death. Among the BCL-2 family members, the expression of pro-apoptotic protein BIM and anti-proapoptotic protein Bcl-xl expression increased significantly when ATXN3 was down-regulated. Downregulation of BIM protected NB cells from the combination of perifosine/MK-2206 and ATXN3 downregulation. Downregulation of ATXN3 did not increase, but decrease the sensitivity of NB cells to etoposide/cisplatin, and knockdown of Bcl-xl attenuated this decrease in sensitivity.

Conclusion

Downregulation of ATXN3 enhanced AKT inhibitors (perifosine or MK-2206) induced cell death by BIM, but decreased the cell death induced by chemotherapeutic drugs (etoposide or cisplatin) via Bcl-xl. The expression of ATXN3 may be an indicator in selecting different treatment regimen.

T-box transcription factor TBX1, targeted by microRNA-6727-5p, inhibits cell growth and enhances cisplatin chemosensitivity of cervical cancer cells through AKT and MAPK pathways

Cervical cancer (CC) is the fourth most common cancers among women worldwide. T-box transcription factor 1 (TBX1), a member of the T-box family, has anti-tumor effects in some types of cancer, but its role in CC is yet unknown. The aim of this study is to investigate the functions and underlying mechanisms of TBX1 in CC. Online database UALCAN showed that TBX1 was down-regulated in CC tissues compared with normal tissues and patients with lower TBX1 expression level had a poor prognosis. TBX1 overexpression significantly decreased the proliferation, migration, and invasion of Hela and SiHa cells. Conversely, cell apoptosis and chemosensitivity to cisplatin were promoted in TBX1-overexpressing CC cells. Moreover, up-regulation of TBX1 inhibited both AKT and MAPK signaling pathways. Furthermore, dual luciferase report assay indicated that TBX1 could directly bind to miR-6727-5p. In addition, TBX1 expression was inhibited by miR-6727-5p mimic and up-regulated by miR-6727-5p inhibitor. Knockdown of TBX1 reversed the inhibitory effect of the miR-6727-5p inhibitor on CC cells. This study demonstrates that TBX1, a target gene of miR-6727-5p, acts as a tumor suppressor in CC, indicating that TBX1 may be a new target for CC therapy.

Transcriptional heterogeneity of clonal plasma cells and immune evasion in immunoglobulin light chain amyloidosis

Immunoglobulin light chain amyloidosis (AL amyloidosis) is characterized by the presence of B cells producing amyloidogenic immunoglobulin light chains (LCs). The low frequency of aberrant B cells in AL is often masked by a polyclonal B cell background, making it difficult for treatment. We analyzed the single-cell RNA sequencing data from GEO database to compare the plasma cell (PCs) in four individuals with AL amyloidosis, one AL subject after treatment, and six healthy controls. High interindividual variability in AL-derived PCs in their expression pattern of known overexpressed genes in multiple myeloma and their usage of V regions in LCs was demonstrated. We also found overexpression of MHC class I molecules as one of the common features of clonal PCs in individuals with AL amyloidosis. Significantly reduced frequencies of circulating natural killer (NK) cells were also observed in a small cohort of AL patients when compared to healthy controls. These data demonstrate that aberrant PCs in AL has a highly diverse transcriptome, an upregulation of MHC, and a dampened capability of immunosurveillance by reduction of circulating NK frequencies. The analysis of clonal PCs at single cell level may provide a better approach for precise molecular profiling and diagnosis of AL amyloidosis.