Role of AKT and mTOR signaling pathways in the induction of epithelial-mesenchymal transition (EMT) process

ATF4/NUPR1 axis promotes cancer cell survival and mediates immunosuppression in clear cell renal cell carcinoma

Cancer cells encounter unavoidable stress during tumor growth. The stress-induced transcription factor, activating transcription factor 4 (ATF4), has been reported to upregulate various adaptive genes involved in salvage pathways to alleviate stress and promote tumor progression. However, this effect is unknown in clear cell renal cell carcinoma (ccRCC). In this study, we found that ATF4 expression was remarkably upregulated in tumor tissues and associated with poor ccRCC outcomes. ATF4 depletion significantly impaired ccRCC cell proliferation, migration, and invasion in vitro and in vivo by inhibiting the AKT/mTOR and epithelial-mesenchymal transition (EMT)-related signaling pathway. RNA sequencing and functional studies identified nuclear protein 1 (NUPR1) as a key downstream target of ATF4 for repressing ferroptosis and promoting ccRCC cell survival. In addition, targeting ATF4 or pharmacological inhibition using NUPR1 inhibitor ZZW115 promoted antitumor immunity in syngeneic graft mouse models, represented by increased infiltration of CD4+ and CD8+ T cells. Furthermore, ZZW115 could improve the response to the PD-1 immune checkpoint blockade. The results demonstrate that the ATF4/NUPR1 signaling axis promotes ccRCC survival and facilitates tumor-mediated immunosuppression, providing a set of potential targets and prognostic indicators for ccRCC patients.

mTOR in the Development of Hypoxic Pulmonary Hypertension Associated with Cardiometabolic Risk Factors

The pathophysiology of pulmonary hypertension is complex and multifactorial. It is a disease characterized by increased pulmonary vascular resistance at the level due to sustained vasoconstriction and remodeling of the pulmonary arteries, which triggers an increase in the mean pulmonary artery pressure and subsequent right ventricular hypertrophy, which in some cases can cause right heart failure. Hypoxic pulmonary hypertension (HPH) is currently classified into Group 3 of the five different groups of pulmonary hypertensions, which are determined according to the cause of the disease. HPH mainly develops as a product of lung diseases, among the most prevalent causes of obstructive sleep apnea (OSA), chronic obstructive pulmonary disease (COPD), or hypobaric hypoxia due to exposure to high altitudes. Additionally, cardiometabolic risk factors converge on molecular mechanisms involving overactivation of the mammalian target of rapamycin (mTOR), which correspond to a central axis in the development of HPH. The aim of this review is to summarize the role of mTOR in the development of HPH associated with metabolic risk factors and its therapeutic alternatives, which will be discussed in this review.

Recent update on anti-tumor mechanisms of valproic acid in glioblastoma multiforme

Glioblastoma multiforme (GBM) is a malignant tumor of the brain that is considered to be incurable. Currently, surgical removal of tumors, chemotherapy with temozolomide, and radiation treatment remain established options for treatment. Nevertheless, the prognosis of those with GBM continues to be poor owing to the inherent characteristics of tumor growth and spread, as well as the resistance to treatment. To effectively deal with the present circumstances, it is vital to do extensive study to understand GBM thoroughly. The following piece provides a concise overview of the most recent advancements in using valproic acid, an antiseizure medication licensed by the FDA, for treating GBM. In this review, we outline the most recent developments of valproic acid in treating GBM, as well as its fundamental mechanisms and practical consequences. Our goal is to provide a greater understanding of the clinical use of valproic acid as a potential therapeutic agent for GBM.

Putative epithelial-mesenchymal transitions during salamander limb regeneration: Current perspectives and future investigations

Previous studies have implicated epithelial-mesenchymal transition (EMT) in salamander limb regeneration. In this review, we describe putative roles for EMT during each stage of limb regeneration in axolotls and other salamanders. We hypothesize that EMT and EMT-like gene expression programs may regulate three main cellular processes during limb regeneration: (1) keratinocyte migration during wound closure; (2) transient invasion of the stump by epithelial cells undergoing EMT; and (3) use of EMT-like programs by non-epithelial blastemal progenitor cells to escape the confines of their niches. Finally, we propose nontraditional roles for EMT during limb regeneration that warrant further investigation, including alternative EMT regulators, stem cell activation, and fibrosis induced by aberrant EMT.

Parishin A Inhibits Oral Squamous Cell Carcinoma via the AKT/mTOR Signaling Pathway

BACKGROUND

Oral squamous cell carcinoma (OSCC) is an aggressive cancer with limited treatment options. Parishin A, a natural compound derived from Gastrodia elata, possesses multiple therapeutic properties. However, its effects on OSCC remain unexplored.

PURPOSE

This study explores the anti-cancer potential of Parishin A on OSCC and its mechanisms.

METHODS

OSCC cell lines YD-10B and Ca9-22 were treated with varying Parishin A concentrations. Cell viability was detected using the CCK-8 assay, and colony formation was evaluated in agarose gel. Migration and invasion ability were assessed through wound healing and Matrigel invasion assays. The protein expression levels involved in the PI3K/AKT/mTOR signaling pathway and epithelial-mesenchymal transition (EMT) markers were examined via Western blotting.

RESULTS

Parishin A inhibited OSCC cell viability in both dose- and time-dependent manners, with significant reductions at 20, 40, 60, and 80 μM, without affecting normal human gingival fibroblasts. Colony formation decreased substantially at ≥40 μM higher Parishin A concentrations in a dose-dependent manner. Also, migration and invasion assays showed significant suppression by Parishin A treatment concentration ≥40 μM in a dose-dependent manner, as evidenced by decreased wound closure and invasion. Western blot analyses revealed increased E-cadherin levels and decreased N-cadherin and vimentin levels, suggesting EMT inhibition. Parishin A also decreased the phosphorylation levels of PI3K, AKT, and mTOR.

CONCLUSION

Collectively, these findings support the potential of Parishin A as an anti-OSCC agent.

The role of liquid-liquid phase separation in defining cancer EMT

Cancer EMT is a pivotal process that drives carcinogenesis, metastasis, and cancer recurrence, with its initiation and regulation intricately governed by biochemical pathways in a precise spatiotemporal manner. Recently, the membrane-less biomolecular condensates formed via liquid-liquid phase separation (LLPS) have emerged as a universal mechanism underlying the spatiotemporal collaboration of biological activities in cancer EMT. In this review, we first elucidate the current understanding of LLPS formation and its cellular functions, followed by an overview of valuable tools for investigating LLPS. Secondly, we examine in detail the LLPS-mediated biological processes crucial for the initiation and regulation of cancer EMT. Lastly, we address current challenges in advancing LLPS research and explore the potential modulation of LLPS using therapeutic agents.

STRIP2 is regulated by the transcription factor Sp1 and promotes lung adenocarcinoma progression via activating the PI3K/AKT/mTOR/MYC signaling pathway

BACKGROUND

Patients with lung adenocarcinoma (LUAD) generally have poor prognosis. The role of striatin-interacting protein 2 (STRIP2) in LUAD remain unclear.

METHODS

Liquid chromatography-mass spectrometry analyses were used to screen the STRIP2-binding proteins and co-immunoprecipitation verified these interactions. A dual luciferase reporter assay explored the transcription factor activating STRIP2 transcription. Xenograft and lung metastasis models assessed STRIP2's role in tumor growth and metastasis in vivo.

RESULTS

STRIP2 is highly expressed in LUAD tissues and is linked to poor prognosis. STRIP2 expression in LUAD cells significantly promoted cell proliferation, invasion, and migration in vitro and in vivo. Mechanistically, STRIP2 boosted the PI3K/AKT/mTOR/MYC cascades by binding AKT. In addition, specificity protein 1, potently activated STRIP2 transcription by binding to the STRIP2 promoter. Blocking STRIP2 reduces tumor growth and lung metastasis in xenograft models.

CONCLUSIONS

Our study identifies STRIP2 is a key driver of LUAD progression and a potential therapeutic target.

NAT10 Overexpression Promotes Tumorigenesis and Epithelial-Mesenchymal Transition Through AKT Pathway in Gastric Cancer

BACKGROUND

N-acetyltransferase 10 (NAT10), the only RNA cytosine acetyltransferase known in humans, contributes to cancer tumorigenesis and progression. This study aims to investigate the effect of NAT10 on the malignant biological properties of gastric cancer (GC) and its underlying mechanism.

METHODS

The expression and prognostic significance of NAT10 in GC were analyzed using The Cancer Genome Atlas (TCGA) and Sun Yat-sen University (SYSU) cohorts. The influence of NAT10 on the malignant biological behaviors of GC was detected by Cell Counting Kit-8 (CCK-8) assay, plate colony formation assay, 5-ethynyl-2'-deoxyuridine (EdU), Transwell migration and invasion assays, scratch wound assay, flow cytometric analysis, and animal studies. The overall level of N4 acetylcytidine (ac4C) in GC was detected by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The downstream signal pathways of NAT10 were analyzed by Gene Set Enrichment Analysis (GSEA) and verified by Western blot (WB) and immunofluorescence (IF).

RESULTS

The significant upregulation of NAT10 expression in GC was associated with a poor prognosis. The knockdown of NAT10 markedly suppressed GC cell proliferation, migration, invasion, and cell cycle progression. Downregulating NAT10 reduced ac4C levels and inhibited AKT phosphorylation and epithelial-mesenchymal transition (EMT) in GC.

CONCLUSIONS

NAT10 functions as an oncogene and may provide a new therapeutic target in GC.

Gentisic acid prevents colorectal cancer metastasis via blocking GPR81-mediated DEPDC5 degradation

BACKGROUND

Metastasis driven by epithelial-mesenchymal transition (EMT) remains a significant contributor to the poor prognosis of colorectal cancer (CRC), and requires more effective interventions. GPR81 signaling has been linked to tumor metastasis, while lacks an efficient specific inhibitor.

PURPOSE

Our study aimed to investigate the effect and mechanism of Gentisic acid on colorectal cancer (CRC) metastasis.

STUDY DESIGN

A lung metastasis mouse model induced by tail vein injection and a subcutaneous graft tumor model were used. Gentisic acid (GA) was administered by an intraperitoneal injection. HCT116 was treated with lactate to establish an in vitro model.

METHODS

MC38 cells with mCherry fluorescent protein were injected into tail vein to investigate lung metastasis ability in vivo. GA was administered by intraperitoneal injection for 3 weeks. The therapeutic effect was evaluated by survival rates, histochemical analysis, RT-qPCR and live imaging. The mechanism was explored using small interfering RNA (siRNA), Western blotting, RT-qPCR and immunofluorescence.

RESULTS

GA had a therapeutic effect on CRC metastasis and improved survival rates and pathological changes in dose-dependent manner. GA emerged as an GPR81 inhibitor, effectively suppressed EMT and mTOR signaling in CRC induced by lactate both in vivo and in vitro. Mechanistically, GA halted lactate-induce degradation of DEPDC5 through impeding the activation of Chaperone-mediated autophagy (CMA).

CONCLUSION

CMA-mediated DEPDC5 degradation is crucial for lactate/GPR81-induced CRC metastasis, and GA may be a promising candidate for metastasis by inhibiting GPR81 signaling.

GSK'872 Improves Prognosis of Traumatic Brain Injury by Switching Receptor-Interacting Serine/Threonine-Protein Kinase 3-dependent Necroptosis to Cysteinyl Aspartate Specific Proteinase-8-Dependent Apoptosis

BACKGROUND

Traumatic brain injury (TBI) is an important health concern in the society. Previous studies have suggested that necroptosis occurs following TBI. However, the underlying mechanisms and roles of necroptosis are not well understood. In this study, we aimed to assess the role of receptor-interacting serine/threonine-protein kinase 3 (RIP3)-mediated necroptosis after TBI both in vitro and in vivo.

METHODS

We established a cell-stretching injury and mouse TBI model by applying a cell injury controller and controlled cortical impactor to evaluate the relationships among necroptosis, apotosis, inflammation, and TBI both in vitro and in vivo.

RESULTS

The results revealed that necroptosis mediated by RIP1, RIP3, and mixed lineage kinase domain-like protein was involved in secondary TBI. Additionally, protein kinase B (Akt), phosphorylated Akt, mammalian target of rapamycin (mTOR), and phosphorylated mTOR potentially contribute to necroptosis. The inhibition of RIP3 by GSK'872 (a specific inhibitor) blocked necroptosis and reduced the activity of Akt/mTOR, leading to the alleviation of inflammation by reducing the levels of NOD-, LRR- and pyrin domain-containing protein 3. Moreover, the inhibition of RIP3 by GSK'872 promoted the activity of cysteinyl aspartate specific proteinase-8, an enzyme involved in apoptosis and inflammation.

CONCLUSIONS

These data demonstrate that RIP3 inhibition could improve the prognosis of TBI, based on the attenuation of inflammation by switching RIP3-dependent necroptosis to cysteinyl aspartate specific proteinase-8-dependent apoptosis.

Bis-arylidene oxindoles for colorectal cancer nanotherapy

Oxindoles are potent anti-cancer agents and are also used against microbial and fungal infections and for treating neurodegenerative diseases. These oxindoles are earlier established as estrogen receptor (ER)-targeted agents for killing ER (+) cancer cells. Our previously developed bis-arylidene oxindole, Oxifen (OXF) exhibits effective targeting towards ER (+) cancer cells which has a structural resemblance with tamoxifen. Herein, we have designed and synthesized few structural analogues of OXF such as BPYOX, ACPOX and ACPOXF to examine its cytotoxicity in different cancer as well as non-cancer cell lines and its potential to form self- aggregates in aqueous solution. Among these series of molecules, ACPOXF showed maximum toxicity in colorectal cancer cell line which are ER (-) but it also kills non-cancer cell line HEK-293, thereby reducing its cancer cell selectivity. Incidentally, ACPOXF exhibits self-aggregation, without the help of a co-lipid with nanometric size in aqueous solution. ACPOXF self-aggregate was co-formulated with glucocorticoid receptor (GR) synthetic ligand, dexamethasone (Dex) (called, ACPOXF-Dex aggregate) which could selectively kill ER (-) colorectal cancer cells and also could increase survivability of colon-tumour bearing mice. ACPOXF-Dex induced ROS up-regulation followed by apoptosis through expression of caspase-3. Further, we observed upregulation of antiproliferative factor, p53 and epithelial-to-mesenchymal (EMT) reversal marker E-cadherin in tumour mass. In conclusion, a typical structural modification in ER-targeting Oxifen moiety resulted in its self-aggregation that enabled it to carry a GR-ligand, thus broadening its selective antitumor property especially as colon cancer therapeutics.

Chloroxine inhibits pancreatic cancer progression through targeted antagonization of the PI3K/AKT/mTOR signaling pathway

BACKGROUND

Patients with pancreatic cancer have a dismal prognosis due to tumor cell infiltration and metastasis. Many reports have documented that EMT and PI3K-AKT-mTOR axis control pancreatic cancer cell infiltration and metastasis. Chloroxine is an artificially synthesized antibacterial compound that demonstrated anti-pancreatic cancer effects in our previous drug-screening trial. We have explored the impact of chloroxine on pancreatic cancer growth, infiltration, migration, and apoptosis.

METHODS

The proliferation of pancreatic cancer cell lines (PCCs) treated with chloroxine was assessed through real-time cell analysis (RTCA), colony formation assay, CCK-8 assay, as well as immunofluorescence. Chloroxine effects on the infiltrative and migratory capacities of PCCs were assessed via Transwell invasion and scratch experiments. To assess the contents of EMT- and apoptosis-associated proteins in tumor cells, we adopted Western immunoblotting as well as immunofluorescence assays, and flow cytometry to determine chloroxine effects on PCCs apoptosis. The in vivo chloroxine antineoplastic effects were explored in nude mice xenografts.

RESULTS

Chloroxine repressed pancreatic cancer cell growth, migration, and infiltration in vitro, as well as in vivo, and stimulated apoptosis of the PCCs. Chloroxine appeared to inhibit PCC growth by Ki67 downregulation; this targeted and inhibited aberrant stimulation of the PI3K-AKT-mTOR signaling cascade, triggered apoptosis in PCC via mitochondria-dependent apoptosis, and modulated the EMT to inhibit PCC infiltration and migration.

CONCLUSIONS

Chloroxine targeted and inhibited the PI3K-AKT-mTOR cascade to repress PCCs growth, migration, as well as invasion, and triggered cellular apoptosis. Therefore, chloroxine may constitute a potential antineoplastic drug for the treatment of pancreatic cancer.

The effect of novel nitrogen-based chalcone analogs on colorectal cancer cells: Insight into the molecular pathways

In colorectal cancer (CRC), aberrations in KRAS are associated with aggressive tumorigenesis and an overall low survival rate because of chemoresistance and adverse effects. Ergo, complementary, and integrative medicines are being considered for CRC treatment. Among which is the use of natural chalcones that are known to exhibit anti-tumor activities in KRAS mutant CRC subtypes treatment regimens. Consequently, we examine the effect of two novel compounds (DK13 and DK14) having chalcones with nitrogen mustard moiety on CRC cell lines (HCT-116 and LoVo) with KRAS mutation. These compounds were synthesized in our lab and previously reported to exhibit potent activity against breast cancer cells. Our data revealed that DK13 and DK14 treatment suppress cell growth, disturb the progression of cell cycle, and trigger apoptosis in CRC cell lines. Besides, treatment with both compounds impedes cell invasion and colony formation in both cell lines as compared to 5-FU; this is accompanied by up and down regulations of E-cadherin and Vimentin, respectively. At the molecular level, both compounds deregulate the expression and phosphorylation of β-catenin, Akt and mTOR, which are the main likely molecular mechanisms underlying these biological occurrences. Our findings present DK13 and DK14 as novel chemotherapies against CRC, through β-catenin/Akt/mTOR signaling pathways.

Assessment of salivary miRNA, clinical, and demographic characterization in colorectal cancer diagnosis

AIM

Colorectal cancer (CRC), as the third most frequent malignancy in the world, is the fourth major cause of cancer-related mortality. Its early detection contributes significantly to a reduction in mortality. The objective of this case-control research was to analyze the salivary expression of microRNA-29a (miR-29a) and microRNA-92a (miR-92a), and also to consider demographic, clinical, and nutritional habits for differentiation between CRC patients and healthy controls, especially in the early stages.

METHOD

A standard checklist was used to obtain the demographic information, clinical features, and dietary habits of the case and control groups. Samplings of whole unstimulated saliva samples were obtained from 33 healthy persons and 42 CRC patients. Through real-time PCR, statistical analyses, and machine learning analyses, miR-29a and miR-92a salivary expression levels were evaluated.

RESULTS

The mean salivary expression of miR-92a and miR-29a in CRC patients was significantly higher than in healthy controls (p < 0.001). The area under the receiver operating characteristic curve for miR-92a and miR-29a salivary biomarkers was 0.947 and 0.978, respectively. The sensitivity and specificity values for miR-92a were 95.24 % and 84.85 %, respectively, whereas sensitivity and specificity for miR-29a were equal to 95.20 % and 87.88 %, respectively. Multiple logistic regressions considering demographics, clinical features, and nutritional habits led to values of 95.35 % and 96.88 % as sensitivity and specificity, respectively, and machine learning analysis led to values of 88.89 % and 86.67 % as sensitivity and specificity, respectively.

CONCLUSION

CRC could be accurately diagnosed based on miR-92a and miR-29a levels in saliva. Statistical analysis and machine learning might develop cost-effective models for the distinction of CRC using a noninvasive technique.

Protein arginine methyltransferases (PRMTs): Orchestrators of cancer pathogenesis, immunotherapy dynamics, and drug resistance

Protein Arginine Methyltransferases (PRMTs) are a family of enzymes regulating protein arginine methylation, which is a post-translational modification crucial for various cellular processes. Recent studies have highlighted the mechanistic role of PRMTs in cancer pathogenesis, immunotherapy, and drug resistance. PRMTs are involved in diverse oncogenic processes, including cell proliferation, apoptosis, and metastasis. They exert their effects by methylation of histones, transcription factors, and other regulatory proteins, resulting in altered gene expression patterns. PRMT-mediated histone methylation can lead to aberrant chromatin remodeling and epigenetic changes that drive oncogenesis. Additionally, PRMTs can directly interact with key signaling pathways involved in cancer progression, such as the PI3K/Akt and MAPK pathways, thereby modulating cell survival and proliferation. In the context of cancer immunotherapy, PRMTs have emerged as critical regulators of immune responses. They modulate immune checkpoint molecules, including programmed cell death protein 1 (PD-1), through arginine methylation. Drug resistance is a significant challenge in cancer treatment, and PRMTs have been implicated in this phenomenon. PRMTs can contribute to drug resistance through multiple mechanisms, including the epigenetic regulation of drug efflux pumps, altered DNA damage repair, and modulation of cell survival pathways. In conclusion, PRMTs play critical roles in cancer pathogenesis, immunotherapy, and drug resistance. In this overview, we have endeavored to illuminate the mechanistic intricacies of PRMT-mediated processes. Shedding light on these aspects will offer valuable insights into the fundamental biology of cancer and establish PRMTs as promising therapeutic targets.

Sialidase NEU3 Contributes to the Invasiveness of Bladder Cancer

Bladder cancer is the 10th most commonly diagnosed cancer worldwide. The current standard treatment for advanced bladder cancer is neoadjuvant cisplatin (NAC)-based chemotherapy followed by cystectomy. However, the response rate to chemotherapy is only 50%, owing to cisplatin resistance, and there is a need for novel therapies. Because the invasiveness of bladder cancer greatly influences patient prognosis, a mechanistic analysis of the invasive function can lead to therapeutic targets. Sialidases, which remove sialic acid residues from the nonreducing ends of sugar chains and catalyze the initial reaction in the degradation of sugar chains, are predicted to be involved in cell invasion and motility. However, the involvement of sialidases in bladder cancer, especially their relationship with the invasive ability, remains unclear. Here, using patient tissues and multiple bladder cancer cell lines, we show that the sialidase NEU3 is highly expressed in bladder cancer. Analysis of NEU3's function using its siRNA-mediated knockdown revealed that NEU3 contributes to bladder cancer invasiveness. Mechanistic analysis showed that NEU3 activates ERK and PI3K signaling. Our results show that NEU3 is involved in the malignancy of bladder cancer, and its suppression may lead to novel treatments for bladder cancer.

Soluble guanylyl cyclase beta1 subunit targets epithelial-to-mesenchymal transition and downregulates Akt pathway in human endometrial and cervical cancer cells

Endometrial and cervical cancer are among the most frequently diagnosed malignancies globally. Nitric oxide receptor-soluble guanylyl cyclase (sGC) is a heterodimeric enzyme composed of two subunits, α1 and β1. Previously we showed that sGCα1 subunit promotes cell survival, proliferation, and migration, but the role of sGCβ1 subunit has not been addressed. The aim of the present work was to study the impact of sGCβ1 restoration in proliferation, survival, migration, and cell signaling in endometrial and cervical cancer cells. We found that sGCβ1 transcript levels are reduced in endometrial and cervical tumors vs normal tissues. We confirmed nuclear enrichment of sGCβ1, unlike sGCα1. Overexpression of sGCβ1 reduced cell viability and augmented apoptotic index. Cell migration and invasion were also negatively affected. All these sGCβ1-driven effects were independent of sGC enzymatic activity. sGCβ1 reduced the expression of epithelial-to-mesenchymal transition factors such as N-cadherin and β-catenin and increased the expression of E-cadherin. sGCβ1 impacted signaling in endometrial and cervical cancer cells through significant downregulation of Akt pathway affecting some of its main targets such as GSK-3β and c-Raf. Our results show for the first time that sGCβ1 exerts several antiproliferative actions in ECC-1 and HeLa cell lines by targeting key regulatory pathways.

The potential relevance of long non-coding RNAs in colorectal cancer pathogenesis and treatment: A review focus on signaling pathways

Colorectal cancer (CRC) is one of the most frequent cancers in incidence and mortality. Despite advances in cancer biology, molecular genetics, and targeted treatments, CRC prognosis and survival have not kept pace. This is usually due to advanced staging and metastases at diagnosis. Thus, great importance has been placed upon understanding the molecular pathophysiology behind the development of CRC, which has highlighted the significance of non-coding RNA's role and associated intracellular signaling pathways in the pathogenesis of the disease. According to recent studies, long non-coding RNAs (lncRNA), a subtype of ncRNAs whose length exceeds 200 nucleotides, have been found to have regulatory functions on multiple levels. Their actions at the transcription, post-transcriptional, translational levels, and epigenetic regulation have made them prime modulators of gene expression. Due to their role in cellular cancer hallmarks, their dysregulation has been linked to several illnesses, including cancer. Furthermore, their clinical relevance has expanded due to their possible detection in blood which has cemented them as potential future biomarkers and thus, potential targets for new therapy. This review will highlight the importance of lncRNAs and related signaling pathways in the development of CRC and their subsequent clinical applications.

Prostate transmembrane androgen inducible protein 1 (PMEPA1): regulation and clinical implications

Prostate transmembrane androgen inducible protein 1 (PMEPA1) can promote or inhibit prostate cancer cell growth based on the cancer cell response to the androgen receptor (AR). Further, it can be upregulated by transforming growth factor (TGF), which downregulates transforming growth factor-β (TGF-β) signaling by interfering with R-Smad phosphorylation to facilitate TGF-β receptor degradation. Studies have indicated the increased expression of PMEPA1 in some solid tumors and its functioning as a regulator of multiple signaling pathways. This review highlights the multiple potential signaling pathways associated with PMEPA1 and the role of the PMEPA1 gene in regulating prognosis, including transcriptional regulation and epithelial mesenchymal transition (EMT). Moreover, the relevant implications in and outside tumors, for example, as a biomarker and its potential functions in lysosomes have also been discussed.

New ruthenium-xanthoxylin complex eliminates colorectal cancer stem cells by targeting the heat shock protein 90 chaperone

In this work, we describe a novel ruthenium-xanthoxylin complex, [Ru(phen)2(xant)](PF6) (RXC), that can eliminate colorectal cancer (CRC) stem cells by targeting the chaperone Hsp90. RXC exhibits potent cytotoxicity in cancer cell lines and primary cancer cells, causing apoptosis in HCT116 CRC cells, as observed by cell morphology, YO-PRO-1/PI staining, internucleosomal DNA fragmentation, mitochondrial depolarization, and PARP cleavage (Asp214). Additionally, RXC can downregulate the HSP90AA1 and HSP90B1 genes and the expression of HSP90 protein, as well as the expression levels of its downstream/client elements Akt1, Akt (pS473), mTOR (pS2448), 4EBP1 (pT36/pT45), GSK-3β (pS9), and NF-κB p65 (pS529), implying that these molecular chaperones can be molecular targets for RXC. Moreover, this compound inhibited clonogenic survival, the percentage of the CRC stem cell subpopulation, and colonosphere formation, indicating that RXC can eliminate CRC stem cells. RXC reduced cell migration and invasion, decreased vimentin and increased E-cadherin expression, and induced an autophagic process that appeared to be cytoprotective, as autophagy inhibitors enhanced RXC-induced cell death. In vivo studies showed that RXC inhibits tumor progression and experimental metastasis in mice with CRC HCT116 cell xenografts. Taken together, these results highlight the potential of the ruthenium complex RXC in CRC therapy with the ability to eliminate CRC stem cells by targeting the chaperone Hsp90.

Identification of basement membrane markers in diabetic kidney disease and immune infiltration by using bioinformatics analysis and experimental verification

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease worldwide. Basement membranes (BMs) are ubiquitous extracellular matrices which are affected in many diseases including DKD. Here, the authors aimed to identify BM-related markers in DKD and explored the immune cell infiltration in this process. The expression profiles of three datasets were downloaded from the Gene Expression Omnibus database. BM-related differentially expression genes (DEGs) were identified and Kyoto encyclopaedia of genes and genomes pathway enrichment analysis were applied to biological functions. Immune cell infiltration and immune function in the kidneys of patients with DKD and healthy controls were evaluated and compared using the ssGSEA algorithm. The association of hub genes and immune cells and immune function were explored. A total of 30 BM-related DEGs were identified. The functional analysis showed that BM-related DEGs were notably associated with basement membrane alterations. Crucially, BM-related hub genes in DKD were finally identified, which were able to distinguish patients with DKD from controls. Moreover, the authors observed that laminin subunit gamma 1(LAMC1) expression was significantly high in HK2 cells treated with high glucose. Immunohistochemistry results showed that, compared with those in db/m mouse kidneys, the levels of LAMC1 in db/db mouse kidneys were significantly increased. The biomarkers genes may prove crucial for DKD treatment as they could be targeted in future DKD treatment protocols.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Combretastatin A-4 suppresses the invasive and metastatic behavior of glioma cells and induces apoptosis in them: in-vitro study

The most common primary brain malignancy, glioblastoma multiforme, is tremendously resistant to conventional treatments due to its potency for metastasis to surrounding brain tissue. Temozolomide is a chemotherapeutic agent that currently is administrated during the treatment procedure. Studies have attempted to investigate new agents with higher effectiveness and fewer side effects. Combretastatin A-4 (CA-4), a natural compound derived from Combretum caffrum, has been recently considered for its potent antitumor activities in a wide variety of preclinical solid tumor models. Our findings have shown that CA-4 exerts potent anti-proliferative and apoptotic effects on glioma cells, and ROS generation may be involved in these cellular events. CA-4 has imposed G2 arrest in U-87 cells. We also observed that CA-4 significantly reduced the migration and invasion capability of U-87 cells. Furthermore, the gene expression and enzyme activity of MMP-2 and MMP-9 were significantly inhibited in the presence of CA-4. We also observed a considerable decrease in PI3K and Akt protein expression following treatment with CA-4. In conclusion, our findings showed significant apoptogenic and anti-metastatic effects of CA-4 on glioma cells and also suggested that the PI3K/Akt/MMP-2/-9 and also ROS pathway might play roles in these cellular events.

Cannabidiol Inhibits the Proliferation and Invasiveness of Prostate Cancer Cells

Prostate cancer is the fifth leading cause of cancer death in men, responsible for over 375,000 deaths in 2020. Novel therapeutic strategies are needed to improve outcomes. Cannabinoids, chemical components of the cannabis plant, are a possible solution. Preclinical evidence demonstrates that cannabinoids can modulate several cancer hallmarks of many tumor types. However, the therapeutic potential of cannabinoids in prostate cancer has not yet been fully explored. The aim of this study was to investigate the antiproliferative and anti-invasive properties of cannabidiol (CBD) in prostate cancer cells in vitro. CBD inhibited cell viability and proliferation, accompanied by reduced expression of key cell cycle proteins, specifically cyclin D3 and cyclin-dependent kinases CDK2, CDK4, and CDK1, and inhibition of AKT phosphorylation. The effects of CBD on cell viability were not blocked by cannabinoid receptor antagonists, a transient receptor potential vanilloid 1 (TRPV1) channel blocker, or an agonist of the G-protein-coupled receptor GPR55, suggesting that CBD acts independently of these targets in prostate cancer cells. Furthermore, CBD reduced the invasiveness of highly metastatic PC-3 cells and increased protein expression of E-cadherin. The ability of CBD to inhibit prostate cancer cell proliferation and invasiveness suggests that CBD may have potential as a future chemotherapeutic agent.

Curcumin ameliorates focal segmental glomerulosclerosis by inhibiting apoptosis and oxidative stress in podocytes

Focal segmental glomerulosclerosis (FSGS), a podocyte disease, is the leading cause of end-stage renal disease (ESRD). Nevertheless, the current effective treatment for FSGS is deficient. Curcumin (CUR) is a principal curcuminoid of turmeric, which is a member of the ginger family. Previous studies have shown that CUR has renoprotective effects. However, the mechanism of CUR in anti-FSGS is not clear. This study aimed to explore the mechanism of CUR against FSGS through a combination of network pharmacological methods and verification of experiments. The analysis identified 98 shared targets of CUR against FSGS, and these 98 targets formed a network of protein-protein interactions (PPI). Of these 98 targets, AKT1, TNF, IL-6, VEGFA, STAT3, MAPK3, HIF1A, CASP3, IL1B, and JUN were identified as the hub targets. Molecular docking suggested that the best binding to CUR is MAPK3 and AKT1. Apoptotic process and cell proliferation were identified as the main biological processes of CUR against FSGS by gene ontology (GO) analysis. The most enriched signaling pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was the PI3K-AKT signaling pathway. Western blots and flow cytometry showed that CUR could inhibit adriamycin (ADR) induced apoptosis, oxidative stress damage, and attenuate podocyte epithelial-mesenchymal transition (EMT) by repressing the AKT signaling pathway. Collectively, our study demonstrates that CUR can attenuate apoptosis, oxidative stress damage, and EMT in FSGS in vitro. These results supply a compelling basis for future studies of CUR for the clinical treatment of FSGS.

Targeting of AKT1 by miR-143-3p Suppresses Epithelial-to-Mesenchymal Transition in Prostate Cancer

An altered expression of miR-143-3p has been previously reported in prostate cancer where it is purported to play a tumor suppressor role. Evidence from other cancers suggests miR-143-3p acts as an inhibitor of epithelial-to-mesenchymal transition (EMT), a key biological process required for metastasis. However, in prostate cancer the interaction between miR-143-3p and EMT-associated mechanisms remains unclear. Therefore, this paper investigated the link between miR-143-3p and EMT in prostate cancer using in vitro and in silico analyses. PCR detected that miR-143-3p expression was significantly decreased in prostate cancer cell lines compared to normal prostate cells. Bioinformatic analysis of The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA PRAD) data showed a significant downregulation of miR-143-3p in prostate cancer, correlating with pathological markers of advanced disease. Functional enrichment analysis confirmed the significant association of miR-143-3p and its target genes with EMT. The EMT-linked gene AKT1 was subsequently shown to be a novel target of miR-143-3p in prostate cancer cells. The in vitro manipulation of miR-143-3p levels significantly altered the cell proliferation, clonogenicity, migration and expression of EMT-associated markers. Further TCGA PRAD analysis suggested miR-143-3p tumor expression may be a useful predictor of disease recurrence. In summary, this is the first study to report that miR-143-3p overexpression in prostate cancer may inhibit EMT by targeting AKT1. The findings suggest miR-143-3p could be a useful diagnostic and prognostic biomarker for prostate cancer.

Silencing of GRHL2 induces epithelial‑to‑mesenchymal transition in lung cancer cell lines with different effects on proliferation and clonogenic growth

Grainyhead-like 2 (GRHL2) is a transcription factor that suppresses epithelial-to-mesenchymal transition (EMT). It has been previously shown that GRHL2 can confer both oncogenic and tumor-suppressive roles in human cancers, including breast, pancreatic and colorectal cancers. However, its role in lung cancer remains elusive. In the present study, a meta-analysis of multiple gene expression datasets with clinical data revealed that GRHL2 expression was increased in lung cancer compared with that in the normal tissues. Copy number analysis of GRHL2, performed using datasets of whole exome sequencing involving 151 lung cancer cell lines, revealed frequent amplifications, suggesting that the increased GRHL2 expression may have resulted from gene amplification. A survival meta-analysis of GRHL2 using The Cancer Genome Atlas (TCGA) dataset showed no association of GRHL2 expression with overall survival. GRHL2 expression was found to be associated with EMT status in lung cancer in TCGA dataset and lung cancer cell lines. GRHL2 knockdown induced partial EMT in the hTERT/Cdk4-immortalized normal lung epithelial cell line HBEC4KT without affecting proliferation measured by CCK-8 assays. In addition, GRHL2 silencing caused three lung cancer cell lines, H1975, H2009 and H441, to undergo partial EMT. However, the proliferative effects differed significantly. GRHL2 silencing promoted proliferation but not colony formation in H1975 cells whilst suppressing colony formation without affecting proliferation in H2009 cells, but it did not affect proliferation in H441 cells. These results suggest cell type-dependent effects of GRHL2 knockdown. Downstream, GRHL2 silencing enhanced the phosphorylation of AKT and ERK, assessed by western blotting with phospho-specific antibodies, in HBEC4KT, H1975 and H2009 cell lines but not in the H441 cell line. By contrast, transient GRHL2 overexpression did not affect A549 cell proliferation, which lack detectable endogenous expression of the GRHL2 protein. However, GRHL2 overexpression did suppress E-cadherin expression in A549 cells. These results suggested that GRHL2 does not only function as a tumor suppressor of EMT but can also behave as an oncogene depending on the lung cancer cell-type context.

PI3K/AKT signaling pathway as a critical regulator of epithelial-mesenchymal transition in colorectal tumor cells

Colorectal cancer (CRC) is one of the most frequent gastrointestinal malignancies that are considered as a global health challenge. Despite many progresses in therapeutic methods, there is still a high rate of mortality rate among CRC patients that is associated with poor prognosis and distant metastasis. Therefore, investigating the molecular mechanisms involved in CRC metastasis can improve the prognosis. Epithelial-mesenchymal transition (EMT) process is considered as one of the main molecular mechanisms involved in CRC metastasis, which can be regulated by various signaling pathways. PI3K/AKT signaling pathway has a key role in CRC cell proliferation and migration. In the present review, we discussed the role of PI3K/AKT pathway CRC metastasis through the regulation of the EMT process. It has been shown that PI3K/AKT pathway can induce the EMT process by down regulation of epithelial markers, while up regulation of mesenchymal markers and EMT-specific transcription factors that promote CRC metastasis. This review can be an effective step toward introducing the PI3K/AKT/EMT axis to predict prognosis as well as a therapeutic target among CRC patients. Video Abstract.

The B56γ3-containing protein phosphatase 2A attenuates p70S6K-mediated negative feedback loop to enhance AKT-facilitated epithelial-mesenchymal transition in colorectal cancer

BACKGROUND

Protein phosphatase 2A (PP2A) is one of the major protein phosphatases in eukaryotic cells and is essential for cellular homeostasis. PP2A is a heterotrimer comprising the dimeric AC core enzyme and a highly variable regulatory B subunit. Distinct B subunits help the core enzyme gain full activity toward specific substrates and contribute to diverse cellular roles of PP2A. PP2A has been thought to play a tumor suppressor and the B56γ3 regulatory subunit was shown to play a key tumor suppressor regulatory subunit of PP2A. Nevertheless, we uncovered a molecular mechanism of how B56γ3 may act as an oncogene in colorectal cancer (CRC).

METHODS

Polyclonal pools of CRC cells with stable B56γ3 overexpression or knockdown were generated by retroviral or lentiviral infection and subsequent drug selection. Co-immunoprecipitation(co-IP) and in vitro pull-down analysis were applied to analyze the protein-protein interaction. Transwell migration and invasion assays were applied to investigate the role of B56γ3 in affecting motility and invasive capability of CRC cells. The sensitivity of CRC cells to 5-fluorouracil (5-FU) was analyzed using the PrestoBlue reagent assay for cell viability. Immunohistochemistry (IHC) was applied to investigate the expression levels of phospho-AKT and B56γ3 in paired tumor and normal tissue specimens of CRC. DataSets of TCGA and GEO were analyzed to investigate the correlation of B56γ3 expression with overall survival rates of CRC patients.

RESULTS

We showed that B56γ3 promoted epithelial-mesenchymal transition (EMT) and reduced the sensitivity of CRC cells to 5-FU through upregulating AKT activity. Mechanistically, B56γ3 upregulates AKT activity by targeting PP2A to attenuate the p70S6K-mediated negative feedback loop regulation on PI3K/AKT activation. B56γ3 was highly expressed and positively correlated with the level of phospho-AKT in tumor tissues of CRC. Moreover, high B56γ3 expression is associated with poor prognosis of a subset of patients with CRC.

CONCLUSIONS

Our finding reveals that the B56γ3 regulatory subunit-containing PP2A plays an oncogenic role in CRC cells by sustaining AKT activation through suppressing p70S6K activity and suggests that the interaction between B56γ3 and p70S6K may serve as a therapeutic target for CRC. Video Abstract.

Exosomal PIK3CB promotes PD-L1 expression and malignant transformation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC), which accounts for 90% of esophageal carcinomas, seriously endangers human health. Worse still, the 5-year overall survival of ESCC is approximately 20%. Elucidation of the potential mechanism and exploration of promising drugs for ESCC are urgently needed. In this study, a high level of exosomal PIK3CB protein was found in the plasma of ESCC patients, which might indicate a poor prognosis. Moreover, a significant Pearson's correlation was observed at the protein level between exosomal PIK3CB and exosomal PD-L1. Further study revealed that cancer cell-intrinsic and exosome-derived PIK3CB promoted the transcriptional activity of the PD-L1 promoter in ESCC cells. Moreover, treatment with exosomes with lower levels of exosomal PIK3CB decreased the protein level of the mesenchymal marker β-catenin while increasing that of the epithelial marker claudin-1, indicating the potential regulation of epithelial-mesenchymal transition. Consequently, the migratory ability and cancer stemness of ESCC cells and the growth of tumors formed by ESCC cells were decreased with the downregulation of exosomal PIK3CB. Therefore, exosomal PIK3CB plays an oncogenic role by promoting PD-L1 expression and malignant transformation in ESCC. This study may provide new insight into the inherent biological aggressiveness and the poor response to currently available therapies of ESCC. Exosomal PIK3CB may be a promising target for the diagnosis and therapy of ESCC in the future.

PRMT5 facilitates angiogenesis and EMT via HIF-1α/VEGFR/Akt signaling axis in lung cancer

Abnormal angiogenesis is a critical factor in tumor growth and metastasis, and protein arginine methyltransferase 5 (PRMT5), a prominent type II enzyme, is implicated in various human cancers. However, the precise role of PRMT5 in regulating angiogenesis to promote lung cancer cell metastasis and the underlying molecular mechanisms are not fully understood. Here, we show that PRMT5 is overexpressed in lung cancer cells and tissues, and its expression is triggered by hypoxia. Moreover, inhibiting or silencing PRMT5 disrupts the phosphorylation of the VEGFR/Akt/eNOS angiogenic signaling pathway, NOS activity, and NO production. Additionally, inhibiting PRMT5 activity reduces HIF-1α expression and stability, resulting in the down-regulation of the VEGF/VEGFR signaling pathway. Our findings indicate that PRMT5 promotes lung cancer epithelial-mesenchymal transition (EMT), which might be possibly through controlling the HIF-1α/VEGFR/Akt/eNOS signaling axis. Our study provides compelling evidence of the close association between PRMT5 and angiogenesis/EMT and highlights the potential of targeting PRMT5 activity as a promising therapeutic approach for treating lung cancer with abnormal angiogenesis.

The beneficial effects of astragaloside IV on ameliorating diabetic kidney disease

Diabetic kidney disease (DKD) has become the major cause of chronic kidney disease or end-stage renal disease. There is still a need for innovative treatment strategies for preventing, arresting, treating, and reversing DKD, and a plethora of scientific evidence has revealed that Chinese herbal monomers can attenuate DKD in multiple ways. Astragaloside IV (AS-IV) is one of the active ingredients of Astragalus membranaceus and was selected as a chemical marker in the Chinese Pharmacopeia for quality control purposes. An increasing amount of studies indicate that AS-IV is a promising novel drug for the treatment of DKD. AS-IV has been shown to improve DKD by combating oxidative stress, attenuating endoplasmic reticulum stress, regulating calcium homeostasis, alleviating inflammation, improving vascular function, improving epithelial to mesenchymal transition and so on. This review briefly summarizes the pathogenesis of DKD, systematically reviews the mechanisms by which AS-IV improves DKD, and aims to facilitate related pharmacological research and development to promote the utilization of Chinese herbal monomers in DKD.

Interferon regulatory factor 4 deletion protects against kidney inflammation and fibrosis in deoxycorticosterone acetate/salt hypertension

BACKGROUND

Inflammation and renal interstitial fibrosis are the main pathological features of hypertensive nephropathy. Interferon regulatory factor 4 (IRF-4) has an important role in the pathogenesis of inflammatory and fibrotic diseases. However, its role in hypertension-induced renal inflammation and fibrosis remains unexplored.

METHOD AND RESULTS

We showed that deoxycorticosterone acetate (DOCA)-salt resulted in an elevation of blood pressure and that there was no difference between wild-type and IRF-4 knockout mice. IRF-4 -/- mice presented less severe renal dysfunction, albuminuria, and fibrotic response after DOCA-salt stress compared with wild-type mice. Loss of IRF-4 inhibited extracellular matrix protein deposition and suppressed fibroblasts activation in the kidneys of mice subjected to DOCA-salt treatment. IRF-4 disruption impaired bone marrow-derived fibroblasts activation and macrophages to myofibroblasts transition in the kidneys in response to DOCA-salt treatment. IRF-4 deletion impeded the infiltration of inflammatory cells and decreased the production of proinflammatory molecules in injured kidneys. IRF-4 deficiency activated phosphatase and tensin homolog and weakened phosphoinositide-3 kinase/AKT signaling pathway in vivo or in vitro . In cultured monocytes, TGFβ1 also induced expression of fibronectin and α-smooth muscle actin and stimulated the transition of macrophages to myofibroblasts, which was blocked in the absence of IRF-4. Finally, macrophages depletion blunted macrophages to myofibroblasts transition, inhibited myofibroblasts accumulation, and ameliorated kidney injury and fibrosis.

CONCLUSION

Collectively, IRF-4 plays a critical role in the pathogenesis of kidney inflammation and fibrosis in DOCA-salt hypertension.

Size-optimized simvastatin-loaded TPGS modified lipid nanocapsules for targeting epithelial-to-mesenchymal transition in hepatocellular carcinoma: Role of PTEN/AKT signaling

OBJECTIVES

Novel D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) modified lipid nanocapsules (LNC) were prepared with the aim of improving the effectiveness of simvastatin (SIM) in hepatocellular carcinoma (HCC). The present study, therefore, sought to investigate the effect of size-optimized SIM-loaded LNC on epithelial-to-mesenchymal transition (EMT) in HCC, providing insights on the implication of phosphatase and tensin homolog (PTEN)/protein kinase B (AKT) axis.

METHODS

Two optimized SIM-loaded LNCs with particle sizes 25 nm (SIM-LNC25) and 50 nm (SIM-LNC50) were prepared and biodistribution studies were performed. The anticancer effect of the prepared LNC was evaluated both in vitro and in vivo. The anti-migratory potential and EMT suppression through PTEN/AKT axis modulation were also explored.

RESULTS

SIM-LNC50 was superior to SIM-LNC25 in both in vitro and in vivo experiments, as evidenced by cytotoxicity assays, tumor histopathology, and enhanced apoptosis. SIM-LNC50 also alleviated the migratory potential of HCC cells. Moreover, EMT markers implied a transition of tumor cells toward the epithelial rather than the mesenchymal phenotype both in vitro and in vivo. PTEN/AKT axis modulation was also evident with SIM-LNC50.

CONCLUSION

The present study, therefore, suggests the efficacy of the 50 nm particles in SIM-loaded LNC in HCC by targeting EMT via modulating the PTEN/AKT signaling axis.

The Role of Histone Deacetylases in Acute Lung Injury-Friend or Foe

Acute lung injury (ALI), caused by intrapulmonary or extrapulmonary factors such as pneumonia, shock, and sepsis, eventually disrupts the alveolar-capillary barrier, resulting in diffuse pulmonary oedema and microatasis, manifested by refractory hypoxemia, and respiratory distress. Not only is ALI highly lethal, but even if a patient survives, there are also multiple sequelae. Currently, there is no better treatment than supportive care, and we urgently need to find new targets to improve ALI. Histone deacetylases (HDACs) are epigenetically important enzymes that, together with histone acetylases (HATs), regulate the acetylation levels of histones and non-histones. While HDAC inhibitors (HDACis) play a therapeutic role in cancer, inflammatory, and neurodegenerative diseases, there is also a large body of evidence suggesting the potential of HDACs as therapeutic targets in ALI. This review explores the unique mechanisms of HDACs in different cell types of ALI, including macrophages, pulmonary vascular endothelial cells (VECs), alveolar epithelial cells (AECs), and neutrophils.

The Role of Tumor Epithelial-Mesenchymal Transition and Macrophage Crosstalk in Cancer Progression

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published findings regarding the role of epithelial to mesenchymal transition (EMT) in tumor progression, macrophages in the tumor microenvironment, and crosstalk that exists between tumor cells and macrophages.

RECENT FINDINGS

EMT is a crucial process in tumor progression. In association with EMT changes, macrophage infiltration of tumors occurs frequently. A large body of evidence demonstrates that various mechanisms of crosstalk exist between macrophages and tumor cells that have undergone EMT resulting in a vicious cycle that promotes tumor invasion and metastasis. Tumor-associated macrophages and tumor cells undergoing EMT provide reciprocal crosstalk which leads to tumor progression. These interactions provide potential targets to exploit for therapy.

Fatostatin induces ferroptosis through inhibition of the AKT/mTORC1/GPX4 signaling pathway in glioblastoma

Glioblastoma multiforme (GBM) is the most common and fatal primary malignant central nervous system tumor in adults. Although there are multiple treatments, the median survival of GBM patients is unsatisfactory, which has prompted us to continuously investigate new therapeutic strategies, including new drugs and drug delivery approaches. Ferroptosis, a kind of regulated cell death (RCD), has been shown to be dysregulated in various tumors, including GBM. Fatostatin, a specific inhibitor of sterol regulatory element binding proteins (SREBPs), is involved in lipid and cholesterol synthesis and has antitumor effects in a variety of tumors. However, the effect of fatostatin has not been explored in the field of ferroptosis or GBM. In our study, through transcriptome sequencing, in vivo experiments, and in vitro experiments, we found that fatostatin induces ferroptosis by inhibiting the AKT/mTORC1/GPX4 signaling pathway in glioblastoma. In addition, fatostatin inhibits cell proliferation and the EMT process through the AKT/mTORC1 signaling pathway. We also designed a p28-functionalized PLGA nanoparticle loaded with fatostatin, which could better cross the blood-brain barrier (BBB) and be targeted to GBM. Our research identified the unprecedented effects of fatostatin in GBM and presented a novel drug-targeted delivery vehicle capable of penetrating the BBB in GBM.

Oncogenic zinc finger protein ZNF687 accelerates lung adenocarcinoma cell proliferation and tumor progression by activating the PI3K/AKT signaling pathway

BACKGROUND

Zinc finger protein 687 (ZNF687) has previously been discovered as a potential oncogene in individuals with giant cell tumors of the bone, acute myeloid leukemia, and hepatocellular carcinoma. However, its role and mechanism in lung adenocarcinoma (LUAD) remain unclear.

METHODS

In LUAD cells, tumor, and matched adjacent tissue specimens, quantitative real-time RT- polymerase chain reaction (qRT-PCR), western blotting analyses, and immunohistochemistry staining (IHC) were conducted. Cell counting kit-8 (CCK8) assay, clonogenicity analysis, flow cytometry, and transwell assays were utilized to detect ZNF687 overexpression and knockdown impacts on cell growth, colony formation, cell cycle, migration, and invasion. Bioinformatic studies, qRT-PCR and western blotting studies were employed to validate the underlying mechanisms and signaling pathways implicated in the oncogenic effect of ZNF687.

RESULTS

This study demonstrated that ZNF687 expression was elevated in LUAD cells and tissues. Individuals with upregulated ZNF687 had a poorer prognosis than those with downregulatedZNF687 (p < 0.001). ZNF687 overexpression enhanced LUAD growth, migration, invasion and colony formation, and the cell cycle G1-S transition; additionally, it promoted the epithelial-mesenchymal transition (EMT). In contrast, knocking down ZNF687 showed to have the opposite impact. Moreover, these effects were associated with the activity of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling mechanism.

CONCLUSION

ZNF687 was upregulated in LUAD, and high ZNF687 expression levels are associated with poor prognoses. The activation of the PI3K/AKT signaling pathway by upregulated ZNF687 increased the proliferation of LUAD cells and tumor progression. ZNF687 may be a beneficial predictive marker and a therapeutic target in LUAD.

Untangling the complexity of heat shock protein 27 in cancer and metastasis

Heat shock protein 27 is a type of molecular chaperone whose expression gets up-regulated due to reaction towards different stressful triggers including anticancer treatments. It is known to be a major player of resistance development in cancer cells, whereby cells are sheltered against the therapeutics that normally activate apoptosis. Heat shock protein 27 (HSP27) is one of the highly expressed proteins during various cellular insults and is a strong tumor survival factor. HSP27 influences various cellular pathways associated with cancer cell survival and growth such as apoptosis, autophagy, metastasis, angiogenesis, epithelial to mesenchymal transition, etc. HSP27 is molecular machinery which prevents the clumping of numerous substrates or client proteins which get mutated in cancer. It has been reported in several studies that targeting HSP27 is difficult because of its dynamic structure and absence of an ATP-binding site. Here, in this review, we have summarized different modulators of HSP27 and their mechanism of action as well. Effect of deregulated HSP27 in various cancer models, limitations of targeting HSP27, resistance against the conventional drugs generated due to the overexpression of HSP27, and measures to counteract this effect have also been discussed here in detail.

Oscillatory ERK Signaling and Morphology Determine Heterogeneity of Breast Cancer Cell Chemotaxis via MEK-ERK and p38-MAPK Signaling Pathways

Chemotaxis, regulated by oscillatory signals, drives critical processes in cancer metastasis. Crucial chemoattractant molecules in breast cancer, CXCL12 and EGF, drive the activation of ERK and Akt. Regulated by feedback and crosstalk mechanisms, oscillatory signals in ERK and Akt control resultant changes in cell morphology and chemotaxis. While commonly studied at the population scale, metastasis arises from small numbers of cells that successfully disseminate, underscoring the need to analyze processes that cancer cells use to connect oscillatory signaling to chemotaxis at single-cell resolution. Furthermore, little is known about how to successfully target fast-migrating cells to block metastasis. We investigated to what extent oscillatory networks in single cells associate with heterogeneous chemotactic responses and how targeted inhibitors block signaling processes in chemotaxis. We integrated live, single-cell imaging with time-dependent data processing to discover oscillatory signal processes defining heterogeneous chemotactic responses. We identified that short ERK and Akt waves, regulated by MEK-ERK and p38-MAPK signaling pathways, determine the heterogeneous random migration of cancer cells. By comparison, long ERK waves and the morphological changes regulated by MEK-ERK signaling, determine heterogeneous directed motion. This study indicates that treatments against chemotaxis in consider must interrupt oscillatory signaling.

Plumbagin downregulates UHRF1, p-Akt, MMP-2 and suppresses survival, growth and migration of cervical cancer CaSki cells

Plumbagin is a natural compound known to impede growth of cancerous cells. However, anti-cervical cancer effects of plumbagin and its underlying molecular mechanism still remains elusive. In this study, plumbagin reduced the viability of CaSki cells in a concentration dependent manner and suppressed their colony formation potential. It led to G2/M phase arrest with downregulation of E2F1 and upregulation of p21. Plumbagin reduced mitochondrial membrane potential and concomitantly increased the percentage of apoptotic cells as revealed by annexin V-propidium iodide staining. Real Time PCR and western blotting confirmed that plumbagin induced apoptosis by reducing the expression of pAkt, procaspase 9 and full-length PARP. Furthermore, scratch assay showed that plumbagin suppressed migratory potential of CaSki cells which could be due to the reduced expression and activity of MMP-2 and upregulation of TIMP2. Interestingly, plumbagin also downregulated UHRF1 expression. Transient silencing of UHRF1 like plumbagin, induced G2/M phase arrest, enhanced apoptosis and suppressed metastasis of CaSki cells suggesting the role of UHRF1 in mediating anti-cancer activities of plumbagin. Plumbagin at IC₂₀ (1 μM) interacted synergistically with cisplatin and reduced its IC₅₀ value by 13.23 fold with improved effectivity as revealed by augmented apoptosis in CaSki cells.

Look who's TORking: mTOR-mediated integration of cell status and external signals during limb development and endochondral bone growth

The balance of cell proliferation and size is key for the control of organ development and repair. Moreover, this balance has to be coordinated within tissues and between tissues to achieve robustness in the organ's pattern and size. The tetrapod limb has been used to study these topics during development and repair, and several conserved pathways have emerged. Among them, mechanistic target of rapamycin (mTOR) signaling, despite being active in several cell types and developmental stages, is one of the least understood in limb development, perhaps because of its multiple potential roles and interactions with other pathways. In the body of this review, we have collated and integrated what is known about the role of mTOR signaling in three aspects of tetrapod limb development: 1) limb outgrowth; 2) chondrocyte differentiation after mesenchymal condensation and 3) endochondral ossification-driven longitudinal bone growth. We conclude that, given its ability to interact with the most common signaling pathways, its presence in multiple cell types, and its ability to influence cell proliferation, size and differentiation, the mTOR pathway is a critical integrator of external stimuli and internal status, coordinating developmental transitions as complex as those taking place during limb development. This suggests that the study of the signaling pathways and transcription factors involved in limb patterning, morphogenesis and growth could benefit from probing the interaction of these pathways with mTOR components.

The transglutaminase 2 cancer cell survival factor maintains mTOR activity to drive an aggressive cancer phenotype

Transglutaminase 2 (TG2) is an important cancer stem-like cell survival protein that is highly expressed in epidermal squamous cell carcinoma and drives an aggressive cancer phenotype. In the present study, we show that TG2 knockdown or inactivation results in a reduction in mammalian target of rapamycin (mTOR) level and activity in epidermal cancer stem-like cells which are associated with reduced spheroid formation, invasion, and migration, and reduced cancer stem cell and epithelial-mesenchymal transition (EMT) marker expression. Similar changes were observed in both cultured cells and tumors. mTOR knockdown or treatment with rapamycin phenocopies the reduction in spheroid formation, invasion, and migration, and cancer stem cell and EMT marker expression. Moreover, mTOR appears to be a necessary mediator of TG2 action, as a forced expression of constitutively active mTOR in TG2 knockdown cells partially restores the aggressive cancer phenotype and cancer stem cell and EMT marker expression. Tumor studies show that rapamycin reduces tumor growth and cancer stem cell marker expression and EMT. These studies suggest that TG2 stimulates mTOR activity to stimulate cancer cell stemness and EMT and drive aggressive tumor growth.

PRMT5/FGFR3/AKT Signaling Axis Facilitates Lung Cancer Cell Metastasis

Objectives: This study aims to investigate the function of the protein arginine methyltransferase 5 (PRMT5) and fibroblast growth factor receptor 3 (FGFR3)/Akt signaling axis in the epithelial-mesenchymal transition (EMT) of human lung cancer. Methods: The mRNA and protein expression levels of PRMT5, FGFR3, p-Akt, and EMT markers are determined by quantitative real-time PCR and Western blotting, respectively; the expression and localization of PRMT5, p-Akt, and proliferating cell nuclear antigen are detected by immunofluorescence; the human lung cancer cell proliferation is measured by MTS assay. Results: PRMT5 and FGFR3 are highly expressed in human lung cancer tissues and are closely related to lymphatic metastasis. Moreover, down-regulation of PRMT5 by lentivirus-mediated shRNAs or inhibition of PRMT5 by specific inhibitors attenuates FGFR3 expression, Akt phosphorylation, and lung cancer cell proliferation. Further studies show that silencing PRMT5 impairs EMT-related markers, including vimentin, collagen I, and β-catenin. Conversely, ectopic expression of PRMT5 increases FGFR3 expression, Akt phosphorylation, and EMT-related markers, suggesting that PRMT5 regulates metastasis probably through the FGFR3/Akt signaling axis. Conclusion: PRMT5/FGFR3/Akt signaling axis controls human lung cancer progression and metastasis and also implies that PRMT5 may serve as a prognostic biomarker and therapeutic candidate for treating lung cancer.

ARFIP2 Regulates EMT and Autophagy in Hepatocellular Carcinoma in Part Through the PI3K/Akt Signalling Pathway

Purpose

ARFIP2, a canonical BAR domain-containing protein, is closely associated with regulating cargo exit from the Golgi. However, the potential biological functions of ARFIP2 in hepatocellular carcinoma (HCC) have not been well investigated. This study aimed to explore the critical role of ARFIP2 in HCC cells.

Methods

The expression of proteins related to epithelial to mesenchymal transition (EMT) and cell autophagy in HCC cells and tissues was assayed by quantitative real-time PCR, Western blotting, immunohistochemistry and immunofluorescence staining. The ability of cells to proliferate, migrate and invade was detected by Cell Counting Kit-8, Transwell migration and invasion assays. In addition, the function of ARFIP2 in vivo was assessed using a tumour xenograft model.

Results

ARFIP2 expression is significantly upregulated in early recurrent and metastatic HCC patients and was positively correlated with a poor prognosis. ARFIP2 overexpression promoted cell proliferation, migration, and invasion by inducing EMT and inhibiting autophagy in vitro. Furthermore, the regulatory effects of ARFIP2 on autophagy and EMT were partially attributed to its regulation of the PI3K/AKT signalling pathway. The in vivo results also showed that ARFIP2 modulates HCC progression.

Conclusion

Our results substantiate a novel mechanism by which ARFIP2 can regulate the activity/phosphorylation of Akt to promote EMT and inhibit autophagy in part via the PI3K/Akt signalling pathway. The ARFIP2/PI3K/Akt axis may be a potential diagnostic biomarker and therapeutic target for HCC.

PCMT1 has Potential Prognostic Value and Promotes Cell Growth and Motility in Breast Cancer.. [DOI: 10.21203/rs.3.rs-2349165/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Breast cancer (BC) is one of the frequently diagnosed cancers, and the leading cause of cancer-related death among women worldwide. The roles of protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) in human cancer have been exploring, but the clinical significance and biological function of PCMT1 in BC are not yet clear. In this study, based on the TCGA-BRCA data set, the results showed that high expression of PCMT1 gene was significantly correlated with shorter overall survival (OS), disease specific survival (DSS) and progress free suvival (PFS) of BC patients. Utilizing the immunohistochemical assay, we found that PCMT1 protein was located in the cytoplasm of BC cells, and PCMT1 expression was only obviously correlated with progesterone receptor expression of patients (p < 0.05). Survival analysis showed that PCMT1 protein high-expression was an independent unfavorable prognostic factor for BC patients. The in vitro experiments revealed that PCMT1 could regulate growth, migration and invasion capacity of MCF-7 cell, and modulate the expression of AKT/GSK3β/mTOR signaling pathway, EMT and cell cycle-associated protein. In conclusion, PCMT1 was a potential unfavorable prognostic biomarker for BC patient and might influence the AKT/GSK3β/mTOR signaling pathway to regulate the growth and motility of MCF-7 cell.

Cycloartocarpin Inhibits Migration through the Suppression of Epithelial-to-Mesenchymal Transition and FAK/AKT Signaling in Non-Small-Cell Lung Cancer Cells

Lung cancer metastasis is a multifaceted process that accounts for 90% of cancer deaths. According to several studies, the epithelial-mesenchymal transition (EMT) plays an essential role in lung cancer metastasis. Therefore, this study aimed to investigate the potential pharmacological effect of cycloartocarpin on the suppression of metastasis-related behaviors and EMT. An MTT assay was used to examine cell viability. Cell migration was determined using a wound healing assay. Anchorage-independent cell growth was also performed. Western blot analysis was used to identify the key signaling proteins involved in the regulation of EMT and migration. The results found that non-toxic concentrations of cycloartocarpin (10-20 μM) effectively suppressed cell migration and attenuated anchorage-independent growth in H292, A549, and H460 cells. Interestingly, these effects were consistent with the findings of Western blot analysis, which revealed that the level of phosphorylated focal adhesion kinase (p-FAK), phosphorylated ATP-dependent tyrosine kinase (p-AKT), and cell division cycle 42 (Cdc42) were significantly reduced, resulting in the inhibition of the EMT process, as evidenced by decreased N-cadherin, vimentin, and slug expression. Taken together, the results suggest that cycloartocarpin inhibits EMT by suppressing the FAK/AKT signaling pathway, which is involved in Cdc42 attenuation. Our findings demonstrated that cycloartocarpin has antimetastatic potential for further research and development in lung cancer therapy.

Reduced IQGAP2 Promotes Bladder Cancer through Regulation of MAPK/ERK Pathway and Cytokines

The progression of non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive bladder cancer (MIBC) is a major challenge in urologic oncology. However, understanding of the molecular processes remains limited. The dysregulation of IQGAP2 is becoming increasingly evident in most tumor entities, and it plays a role in multiple oncogenic pathways, so we evaluated the role of IQGAP2 in bladder cancer. IQGAP2 was downregulated in tumors compared with normal urothelium tissues and cells. IQGAP2 effectively attenuated bladder cancer cell growth independently from apoptosis. Reduced IQGAP2 promoted EMT in bladder cancer cells via activation of the MAPK/ERK pathway. In addition, IQGAP2 might influence key cellular processes, such as proliferation and metastasis, through the regulation of cytokines. In conclusion, we suggest that IQGAP2 plays a tumor-suppressing role in bladder cancer, possibly via inhibiting the MAPK/ERK pathway and reducing cytokines.

Immune Pathway and Gene Database (IMPAGT) Revealed the Immune Dysregulation Dynamics and Overactivation of the PI3K/Akt Pathway in Tumor Buddings of Cervical Cancer

Tumor budding (TB) is a small cluster of malignant cells at the invasive front of a tumor. Despite being an adverse prognosis marker, little research has been conducted on the tumor immune microenvironment of tumor buddings, especially in cervical cancer. Therefore, RNA sequencing was performed using 21 formalin-fixed, paraffin-embedded slides of cervical tissues, and differentially expressed genes (DEGs) were analyzed. Immune Pathway and Gene Database (IMPAGT) was generated for immune profiling. "Pathway in Cancer" was identified as the most enriched pathway for both up- and downregulated DEGs. Kyoto Encyclopedia of Genes and Genomes Mapper and Gene Ontology further revealed the activation of the PI3K/Akt signaling pathway. An IMPAGT analysis revealed immune dysregulation even at the tumor budding stage, especially in the PI3K/Akt/mTOR axis, with a high efficiency and integrity. These findings emphasized the clinical significance of tumor buddings and the necessity of blocking the overactivation of the PI3K/Akt/mTOR pathway to improve targeted therapy in cervical cancer.