Mesoporous cerium oxide nanoenzyme for Efficacious impeding tumor and metastasis via Conferring resistance to anoikis.

Tumor cells can survive when detached from the extracellular matrix or lose cell-to-cell connections, leading to a phenomenon known as anoikis resistance (AR). AR is closely associated with the metastasis and proliferation of tumor cells, enabling them to disseminate, migrate, and invade after detachment. Here, we have investigated a novel composite nanoenzyme comprising mesoporous silica/nano-cerium oxide (MSN-Ce@SP/PEG). This nanoenzyme exhibited satisfactory catalase (CAT) activity, efficiently converting high levels of H2O2 within tumor cells into O2, effectively alleviating tumor hypoxia. Furthermore, MSN-Ce@SP/PEG nanoenzyme demonstrated high peroxidase (POD) activity, elevating reactive oxygen species (ROS) levels and attenuating AR in hepatocellular carcinoma (HCC) cells. The MSN-Ce@SP/PEG nanoenzyme exhibited satisfactory dual bioactivity in CAT and POD and was significantly enhanced under favorable photothermal conditions. Through the synergistic effects of these capabilities, the nanoenzyme disrupted the epithelial-mesenchymal transition (EMT) process in detached HCC cells, ultimately inhibiting the recurrence and metastasis potential of anoikis-resistant HCC cells. This study represents the first report of a novel nanoenzyme based on mesoporous silica/nano-cerium oxide for treating AR in HCC cells, thereby suppressing HCC recurrence and metastasis. The findings of this work offer a pioneering perspective for the development of innovative strategies to prevent the recurrence and metastasis of HCC.

FOSL1 promotes stem cell­like characteristics and anoikis resistance to facilitate tumorigenesis and metastasis in osteosarcoma by targeting SOX2.

Metastasis is the leading cause of cancer­related death in osteosarcoma (OS). OS stem cells (OSCs) and anoikis resistance are considered to be essential for tumor metastasis formation. However, the underlying mechanisms involved in the maintenance of a stem­cell phenotype and anoikis resistance in OS are mostly unknown. Fos­like antigen 1 (FOSL1) is important in maintaining a stem­like phenotype in various cancers; however, its role in OSCs and anoikis resistance remains unclear. In the present study, the dynamic expression patterns of FOSL1 were investigated during the acquisition of cancer stem­like properties using RNA sequencing, PCR, western blotting and immunofluorescence. Flow cytometry, tumor­sphere formation, clone formation assays, anoikis assays, western blotting and in vivo xenograft and metastasis models were used to further investigate the responses of the stem­cell phenotype and anoikis resistance to FOSL1 overexpression or silencing in OS cell lines. The underlying molecular mechanisms were evaluated, focusing on whether SOX2 is crucially involved in FOSL1­mediated stemness and anoikis in OS. FOSL1 expression was observed to be upregulated in OSCs and promoted tumor­sphere formation, clone formation and tumorigenesis in OS cells. FOSL1 expression correlated positively with the expression of stemness­related factors (SOX2, NANOG, CD117 and Stro1). Moreover, FOSL1 facilitated OS cell anoikis resistance and promoted metastases by regulating the expression of apoptosis related proteins BCL2 and BAX. Mechanistically, FOSL1 upregulated SOX2 expression by interacting with the SOX2 promoter and activating its transcription. The results also showed that SOX2 is critical for FOSL1­mediated stem­like properties and anoikis resistance. The current findings indicated that FOSL1 is an important regulator that promotes a stem cell­like phenotype and anoikis resistance to facilitate tumorigenesis and metastasis in OS by regulating the transcription of SOX2. Thus, FOSL1 might represent an attractive target for therapeutic interventions in OS.

mRNA-Lipid Nanoparticle-Mediated Restoration of PTPN14 Exhibits Antitumor Effects by Overcoming Anoikis Resistance in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) poses a challenging prognosis due to early metastasis driven by anoikis resistance. Identifying crucial regulators to overcome this resistance is vital for improving patient outcomes. In this study, a genome-wide CRISPR/Cas9 knockout screen in TNBC cells has identified tyrosine-protein phosphatase nonreceptor type 14 (PTPN14) as a key regulator of anoikis resistance. PTPN14 expression has shown a progressive decrease from normal breast tissue to metastatic tumors. Overexpressing PTPN14 has induced anoikis and inhibited cell proliferation in TNBC cells, while normal human breast cells are unaffected. Mechanistically, PTPN14 is identified as a key factor in dephosphorylating breast cancer antiestrogen resistance 3, a novel substrate, leading to the subsequent inhibition of PI3K/AKT and ERK signaling pathways. Local delivery of in vitro transcribed PTPN14 mRNA encapsulated by lipid nanoparticles in a TNBC mouse model has effectively inhibited tumor growth and metastasis, prolonging survival. The study underscores PTPN14 as a potential therapeutic target for metastatic TNBC, with the therapeutic strategy based on mRNA expression of PTPN14 demonstrating clinical application prospects in alleviating the burden of both primary tumors and metastatic disease.

Targeting Bmi1 for Enhancing Anoikis Sensitivity and Inhibiting Metastasis in Colorectal Cancer.

BACKGROUND/AIM: Patients diagnosed with advanced metastatic colorectal cancer (CRC) confront a bleak prognosis characterized by low survival rates. Anoikis, the programmed apoptosis resistance exhibited by metastatic cancer cells, is a crucial factor in this scenario. MATERIALS AND METHODS: We employed bulk flow cytometry and RT-qPCR assays, conducted in vivo experiments with mice and zebrafish, and analyzed patient tissues to examine the effects of the B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi1)-midkine (MDK) axis on the cellular response to anoikis. Bmi1 is pivotal in tumorigenesis. This study elucidated the involvement of Bmi1 in conferring anoikis resistance in CRC and explored its downstream targets associated with metastasis. RESULTS: Elevated levels of Bmi1 expression correlated with distant metastasis in CRC. Suppression of Bmi1 significantly diminished the metastatic potential of CRC cells. Inhibition of Bmi1 led to an increase in the proportion of apoptotic SW620 cells detached from the matrix. This effect was further enhanced by the addition of irinotecan, a topoisomerase I inhibitor. Furthermore, Bmi1 was found to synergize with MDK in modulating CRC viability, with consistent expression patterns observed in in vivo models and clinical tissue specimens. In summary, Bmi1 acted as a regulator of CRC metastatic capability by conferring anoikis resistance. Additionally, it collaborated with MDK to facilitate invasion and distant metastasis. CONCLUSION: Targeting Bmi1 may offer a promising adjunctive therapeutic strategy when administering traditional chemotherapy regimens to patients with advanced CRC.

FASN promotes anoikis resistance in colorectal liver metastases through the ERK1/2 pathway.

PURPOSE: Colorectal cancer (CRC) is recognized as the third most common form of malignancy, with the liver frequently serving as the main site for metastasis. Anoikis resistance (AR) is critical in colorectal cancer liver metastases (CRLM). Fatty acid synthase (FASN), essential in lipid synthesis, mediates AR in many cancers. The present research examines the function of FASN in ERK1/2-mediated AR in CRLM and evaluates its therapeutic potential. METHODS: We performed scratch and migration experiment to evaluate the migration capacity of the LoVo cells. Flow cytometry was employed to identify cell apoptosis. The levels of FASN, p-ERK1/2, and proteins related to apoptosis was analyzed by Western blot. The mRNA level of FASN was determined by q-PCR after FASN silencing. In addition, we used an intrasplenic liver metastasis model of nude to assess the effect of FASN on CRLM. RESULTS: In vitro experiments showed that after FASN silencing, the cell apoptosis rate was increased, migration capability was notably decreased, the expression of p-ERK1/2, the proteins related to anti-apoptotic were significantly decreased, and the proteins related to apoptosis were significantly increased. In vivo experiments showed that AR significantly increased the number of liver metastatic foci, whereas FASN silencing significantly inhibited CRLM. CONCLUSION: These results suggest that FASN silencing suppressed AR through the ERK 1/2 pathway, which in turn suppressed CRLM.

A thermo-sensitive hydrogel with prominent hemostatic effect prevents tumor recurrence via anti-anoikis-resistance.

Tumor cells can survive when detached from the extracellular matrix (ECM) or lose cell-cell connections, a phenomenon known as anoikis-resistance (AR). AR is closely associated with tumor cell metastasis and recurrence, enabling tumor cells to disseminate, migrate, and invade after detachment. To address this issue, a novel intervention method combining intraoperative hemostasis with multifunctional nanozyme driven-enhanced chemodynamic therapy (ECDT) has been proposed, which holds the potential to weaken the AR capability of tumor cells and suppress tumor recurrence. Here, a nanocomposite containing a dendritic mesoporous nanoframework with Cu2+ was developed using an anion-assisted approach after surface PEG grafting and glucose oxidase (GOx) anchoring (DMSN-Cu@GOx/PEG). DMSN-Cu@GOx/PEG was further encapsulated in a thermal-sensitive hydrogel (H@DMSN-Cu@GOx/PEG). DMSN-Cu@GOx/PEG utilizes its high peroxidase (POD) activity to elevate intracellular ROS levels, thereby weakening the AR capability of bladder cancer cells. Additionally, through its excellent catalase (CAT) activity, DMSN-Cu@GOx/PEG converts the high level of hydrogen peroxide (H2O2) catalyzed by intracellular GOx into oxygen (O2), effectively alleviating tumor hypoxia, downregulating hypoxia-inducible factor-1α (HIF-1α) expression, inhibiting epithelial-mesenchymal transition (EMT) processes, and ultimately suppressing the migration and invasion of bladder cancer cells. Interestingly, in vivo results showed that the thermosensitive hydrogel H@DMSN-Cu@GOx/PEG could rapidly gel at body temperature, forming a gel film on wounds to eliminate residual tumor tissue after tumor resection surgery. Importantly, H@DMSN-Cu@GOx/PEG exhibited excellent hemostatic capabilities, effectively enhancing tissue coagulation during post-tumor resection surgery and mitigating the risk of cancer cell dissemination and recurrence due to surgical bleeding. Such hydrogels undoubtedly possess strong surgical application. Our developed novel nanosystem and hydrogel can inhibit the AR capability of tumor cells and prevent recurrence post-surgery. This study represents the first report of using dendritic mesoporous silica-based nanoreactors for inhibiting the AR capability of bladder cancer cells and suppressing tumor recurrence post-surgery, providing a new avenue for developing strategies to impede tumor recurrence after surgery.

The critical role of glutamine and fatty acids in the metabolic reprogramming of anoikis-resistant melanoma cells.

Introduction: Circulating tumor cells (CTCs) represent the sub-population of cells shed into the vasculature and able to survive in the bloodstream, adhere to target vascular endothelial cells, and re-growth into the distant organ. CTCs have been found in the blood of most solid tumor-bearing patients and are used as a diagnostic marker. Although a complex genotypic and phenotypic signature characterizes CTCs, the ability to survive in suspension constitutes the most critical property, known as resistance to anoikis, e.g., the ability to resist apoptosis resulting from a loss of substrate adhesion. Here, we selected melanoma cells resistant to anoikis, and we studied their metabolic reprogramming, with the aim of identifying new metabolic targets of CTCs. Methods: Subpopulations of melanoma cells expressing a high anoikis-resistant phenotype were selected by three consecutive rocking exposures in suspension and studied for their phenotypic and metabolic characteristics. Moreover, we tested the efficacy of different metabolic inhibitors targeting glycolysis (2DG), LDHA (LDHA-in-3), the mitochondrial electron transport chain complex I (rotenone), glutaminase (BPTES), fatty acid transporter (SSO), fatty acid synthase (denifanstat), CPT1 (etomoxir), to inhibit cell survival and colony formation ability after 24 h of rocking condition. Results: Anoikis-resistant cells displayed higher ability to grow in suspension on agarose-covered dishes respect to control cells, and higher cell viability and colony formation capability after a further step in rocking condition. They showed also an epithelial-to-mesenchymal transition associated with high invasiveness and a stemness-like phenotype. Anoikis-resistant melanoma cells in suspension showed a metabolic reprogramming from a characteristic glycolytic metabolism toward a more oxidative metabolism based on the use of glutamine and fatty acids, while re-adhesion on the dishes reversed the metabolism to glycolysis. The treatment with metabolic inhibitors highlighted the effectiveness of rotenone, BPTES, SSO, and etomoxir in reducing the viability and the colony formation ability of cells capable of surviving in suspension, confirming the dependence of their metabolism on oxidative phosphorylation, using glutamine and fatty acids as the most important fuels. Discussion: This finding opens up new therapeutic strategies based on metabolic inhibitors of glutaminase and fatty acid oxidation for the treatment of CTCs and melanoma metastases.

The resistance to anoikis, mediated by Spp1, and the evasion of immune surveillance facilitate the invasion and metastasis of hepatocellular carcinoma.

Anoikis-Related Genes (ARGs) lead to the organism manifesting resistance to anoikis and are associated with unfavorable prognostic outcomes across various malignancies.Therefore, it is crucial to identify the pivotal target genes related to anoikis in HCC .We found that ARGs were significantly correlated with prognosis and immune responses in HCC. The core gene, SPP1, notably promoted anoikis resistance and metastasis in HCC through both in vivo and in vitro studies. The PI3K-Akt-mTOR pathway played a critical role in anoikis suppression within HCC contexts. Our research unveiled SPP1's role in enhancing PKCα phosphorylation, which in turn activated the PI3K-Akt-mTOR cascade. Additionally, SPP1 was identified as a key regulator of MDSCs and Tregs migration, directly affecting their immunosuppressive capabilities.These findings indicate that in HCC, SPP1 promoted anoikis resistance and facilitated immune evasion by modulating MDSCs and Tregs.

ASS1 Enhances Anoikis Resistance via AMPK/CPT1A-mediated Fatty Acid Metabolism in Ovarian Cancer.

Metastasis is the leading cause of death in ovarian cancer (OC), with anoikis resistance being a crucial step for detached OC cells survival. Despite extensive research, targeting anoikis resistance remians a challenge. Here, we identify argininosuccinate synthase 1 (ASS1), a key enzyme in urea cycle, is markedly upregulated in OC cells in detached culture and is associated with increased anoikis resistance and metastasis. Disruption of the AMP/ATP balance by elevated ASS1 activates AMPK and its downstream factor, CPT1A. Then, ASS1 enhances FAO, leading to higher ATP generation and lipid utilization. Inhibition of CPT1A reverses ASS1-induced FAO. Our study gives some new functional insights into OC metabolism and represents a shift from traditional views, expanding ASS1's relevance beyond nitrogen metabolism to fatty acid metabolism. It uncovers how ASS1-induced FAO disrupts the AMP/ATP balance, leading to AMPK activation. By identifying the ASS1/AMPK/CPT1A axis as crucial for OC anoikis resistance and metastasis, our study opens up new avenues for therapeutic interventions.

Targeting anoikis resistance as a strategy for cancer therapy.

Anoikis, known as matrix detachment-induced apoptosis or detachment-induced cell death, is crucial for tissue development and homeostasis. Cancer cells develop means to evade anoikis, e.g. anoikis resistance, thereby allowing for cells to survive under anchorage-independent conditions. Uncovering the mechanisms of anoikis resistance will provide details about cancer metastasis, and potential strategies against cancer cell dissemination and metastasis. Here, we summarize the principal elements and core molecular mechanisms of anoikis and anoikis resistance. We discuss the latest progress of how anoikis and anoikis resistance are regulated in cancers. Furthermore, we summarize emerging data on selective compounds and nanomedicines, explaining how inhibiting anoikis resistance can serve as a meaningful treatment modality against cancers. Finally, we discuss the key limitations of this therapeutic paradigm and possible strategies to overcome them. In this review, we suggest that pharmacological modulation of anoikis and anoikis resistance by bioactive compounds could surmount anoikis resistance, highlighting a promising therapeutic regimen that could be used to overcome anoikis resistance in cancers.

Empagliflozin drives ferroptosis in anoikis-resistant cells by activating miR-128-3p dependent pathway and inhibiting CD98hc in breast cancer.

A tumour suppressor miRNA, miR-128-3p, is widely involved in various biological processes and has been found to get downregulated in breast cancer patients. We previously published that ectopically expressed miR-128-3p suppressed migration, invasion, cell cycle arrest, and breast cancer stem cells. In the present study, we explored the role of Empagliflozin (EMPA) as a miR-128-3p functionality-mimicking drug in inducing ferroptosis by inhibiting CD98hc. Given that CD98hc is one of the proteins critical in triggering ferroptosis, we confirmed that miR-128-3p and EMPA inhibited SP1, leading to inhibition of CD98hc expression. Further, transfection with siCD98hc, miR-128-3p mimics, and inhibitors was performed to assess their involvement in the ferroptosis of anoikis-resistant cells. We proved that anoikis-resistant cells possess high ROS and iron levels. Further, miR-128-3p and EMPA treatments induced ferroptosis by inhibiting GSH and enzymatic activity of GPX4 and also induced lipid peroxidation. Moreover, EMPA suppressed bioluminescence of 4T1-Red-FLuc induced thoracic cavity, peritoneal tumour burden and lung nodules in an in-vivo metastatic model of breast cancer. Collectively, we revealed that EMPA sensitized the ECM detached cells to ferroptosis by synergically activating miR-128-3p and lowering the levels of SP1 and CD98hc, making it a potential adjunct drug for breast cancer chemotherapy.

Construction of a gene signature associated with anoikis to evaluate the prognosis and immune infiltration in patients with colorectal cancer.

Background: Colorectal cancer (CRC) is characterized by a high metastasis rate, leading to poor prognosis and increased mortality. Anoikis, a physiological process, serves as a crucial barrier against metastasis. The objective of this research is to construct a prognostic model for CRC based on genes associated with anoikis. Methods: The study involved differential analysis and univariate Cox analysis of anoikis-related genes (ARGs), resulting in the selection of 47 genes closely associated with prognosis. Subsequently, unsupervised k-means clustering analysis was conducted on all patients to identify distinct clusters. Survival analysis, principal component analysis (PCA), and t-distributed stochastic neighbor embedding (t-SNE) analysis were performed on the different clusters to investigate associations within the clusters. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were utilized to assess metabolic pathway enrichment between the identified clusters. Furthermore, single-sample GSEA (ssGSEA) was applied to explore variations in immune infiltration. Multivariable Cox regression and least absolute shrinkage and selection operator (LASSO) analyses were conducted to construct a risk model based on ten signatures, which enabled the grouping of all samples according to their risk scores. The prognostic value of the model was validated using receiver operating characteristic (ROC) curves, area under the curve (AUC) calculations, and survival curves. Additionally, the expression of candidate genes was validated using quantitative real-time polymerase chain reaction (qRT-PCR). Results: Forty-seven survival-related ARGs were screened out. Somatic mutation analysis showed that these genes revealed a high mutation rate. Based on their expression, two clusters were identified. Cluster B patients exhibited a shortened overall survival and higher immune infiltration. A risk scoring model including ten genes was subsequently developed, which exhibited excellent prognostic predictive ability for CRC, as evidenced by the survival curve, ROC curve, and AUC curve. In addition, a nomogram was developed for predicting 3- and 5-year survival probabilities. The qRT-PCR results indicated the dissimilarities among the ten signatures in the tumor tissues and adjacent tissues of patients with CRC were fundamentally consistent with the analytical findings. Conclusions: This study comprehensively evaluated the prognostic significance of ARGs in CRC. It identified two distinct anoikis-related clusters and examined their respective immune microenvironments. Furthermore, an ARGs signature was developed to effectively predict the prognosis of CRC, thereby establishing a solid foundation for investigating the clinical prognostic role of anoikis in CRC.

ENO2 promotes anoikis resistance in anaplastic thyroid cancer by maintaining redox homeostasis.

Background: Anoikis presents a significant barrier in the metastasis of cancer. As the most aggressive type of thyroid cancer, anaplastic thyroid cancer (ATC) exhibits a high risk of metastasis and is characterized by high mortality. Therefore, investigating the molecular mechanisms of anoikis resistance in ATC is important for devising therapeutic targets in clinical research. Methods: Differentially Expressed Genes were screened in ATC cells under attached and detached culture conditions with RNA-seq. Investigate the impact of enolase 2 (ENO2) on apoptosis and spheroid formation by gain and loss of function. Changes of reactive oxygen species (ROS), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) were detected to assess redox balance. The transcriptional regulatory role of signal transducer and activator of transcription 1 (STAT1) on ENO2 was validated through Dual-Luciferase Reporter Gene Assay. Explore the impact of ENO2 expression on the formation of lung metastases in nude mice. Results: We found that the glycolysis process was activated in detached ATC cells. Several genes in the glycolysis process, particularly ENO2, a member of the enolase superfamily was upregulated in ATC cells cultured in suspension. The upregulation of ENO2 enabled the maintenance of redox balance by supplying GSH and NADPH, thereby preventing cells from undergoing anoikis. In terms of mechanism, the expression of STAT1 was enhanced in anoikis resistance cells, which in turn positively regulated the expression of ENO2. In vivo, ENO2-suppressed ATC cells resulted in a significantly lower rate of lung colonization compared to control ATC cells. Conclusions: Stable expression of ENO2 and the maintenance of redox balance played a pivotal role in facilitating anoikis resistance of ATC.

G-protein-coupled estrogen receptor 1 promotes peritoneal metastasis of gastric cancer through nicotinamide adenine dinucleotide kinase 1-mediated redox modulation.

Adipose tissue is the second most important site of estrogen production, where androgens are converted into estrogen by aromatase. While gastric cancer patients often develop adipocyte-rich peritoneal metastasis, the underlying mechanism remains unclear. In this study, we identified the G-protein-coupled estrogen receptor (GPER1) as a promoter of gastric cancer peritoneal metastasis. Functional in vitro studies revealed that ß-Estradiol (E2) or the GPER1 agonist G1 inhibited anoikis in gastric cancer cells. Additionally, genetic overexpression or knockout of GPER1 significantly inhibited or enhanced gastric cancer cell anoikis in vitro and peritoneal metastasis in vivo, respectively. Mechanically, GPER1 knockout disrupted the NADPH pool and increased reactive oxygen species (ROS) generation. Conversely, overexpression of GPER1 had the opposite effects. GPER1 suppressed nicotinamide adenine dinucleotide kinase 1(NADK1) ubiquitination and promoted its phosphorylation, which were responsible for the elevated expression of NADK1 at protein levels and activity, respectively. Moreover, genetic inhibition of NADK1 disrupted NADPH and redox homeostasis, leading to high levels of ROS and significant anoikis, which inhibited lung and peritoneal metastasis in cell-based xenograft models. In summary, our study suggests that inhibiting GPER1-mediated NADK1 activity and its ubiquitination may be a promising therapeutic strategy for peritoneal metastasis of gastric cancer.

C9orf10/Ossa regulates the bone metastasis of established lung adenocarcinoma cell subline H322L-BO4 in a mouse model.

Lung cancer frequently metastasizes to the bones. An in vivo model is urgently required to identify potential therapeutic targets for the prevention and treatment of lung cancer with bone metastasis. We established a lung adenocarcinoma cell subline (H322L-BO4) that specifically showed metastasis to the leg bones and adrenal glands. This was achieved by repeated isolation of metastatic cells from the leg bones of mice. The cells were intracardially injected into nude mice. Survival was prolonged for mice that received H322L-BO4 cells versus original cells (H322L). H322L-BO4 cells did not exhibit obvious changes in general in vitro properties associated with the metastatic potential (e.g., cell growth, migration, and invasion) compared with H322L cells. However, the phosphorylation of chromosome 9 open reading frame 10/oxidative stress-associated Src activator (C9orf10/Ossa) was increased in H322L-BO4 cells. This result confirmed the increased anchorage independence through C9orf10/Ossa-mediated activation of Src family tyrosine kinase. Reduction of C9orf10/Ossa by shRNA reduced cells' metastasis to the leg bone and prolonged survival in mice. These findings indicate that H322L-BO4 cells can be used to evaluate the effect of candidate therapeutic targets against bone metastatic lung cancer cells. Moreover, C9orf10/Ossa may be a useful target for treatment of lung cancer with bone metastasis.

Qizhu Anti-Cancer Recipe promotes anoikis of hepatocellular carcinoma cells by activating the c-Jun N-terminal kinase pathway.

Background: Qizhu Anti-Cancer Recipe (QACR) is a traditional Chinese medicine widely used in treating several liver diseases. However, its function and the relevant mechanism underlying its effect in treating hepatocellular carcinoma (HCC) remain unknown. The aim of this study was to explore the effect of QACR in HCC, which are expected to be a potential therapeutic scheme for HCC. Materials and methods: The chemical compositions of QACR were determined by liquid chromatography/quadrupole time-of-fight mass spectrometry (LC-QTOF-MS). The anoikis-resistant HCC cell proliferation and angiopoiesis were detected using the cell counting kit 8 (CCK8) assay, trypan blue, calcein AM/EthD-1, flow cytometer, Western blot, and tube formation assays. An orthotopic xenograft mouse model was established to evaluate the in vivo effects of the QACR. The expression of proliferating cell nuclear antigen (PCNA), Bcl-2, CD31, caspase-3, caspase-8, caspase-9, PARP-1, DFF40, phospho-c-Jun NH2-terminal kinase (p-JNK), and JNK was assessed using Western blot and immunohistochemical analysis. Results: QACR reduced the growth and tube formation of anoikis-resistant HCC cells and enhanced cell apoptosis in vitro. In the orthotopic xenograft mouse models, QACR suppressed the tumorigenesis of HCC in vivo. Mechanistically, QACR modulated the JNK pathway. The JNK inhibitor (SP600125) reverses the inhibitory effects of QACR on anoikis-resistant HCC cell proliferation and angiopoiesis. Conclusion: Our study suggests that QACR suppresses the proliferation and angiopoiesis of anoikis-resistant HCC cells by activating the JNK pathway. Therefore, QACR is a promising new therapeutic strategy for treating hepatocellular carcinoma.

Anoikis resistance and immune escape mediated by Epstein-Barr virus-encoded latent membrane protein 1-induced stabilization of PGC-1α promotes invasion and metastasis of nasopharyngeal carcinoma.

BACKGROUND: Epstein-Barr virus (EBV) is the first discovered human tumor virus that is associated with a variety of malignancies of both lymphoid and epithelial origin including nasopharyngeal carcinoma (NPC). The EBV-encoded latent membrane protein 1 (LMP1) has been well-defined as a potent oncogenic protein, which is intimately correlated with NPC pathogenesis. Anoikis is considered to be a physiological barrier to metastasis, and avoiding anoikis is a major hallmark of metastasis. However, the role of LMP1 in anoikis-resistance and metastasis of NPC has not been fully identified. METHODS: Trypan blue staining, colony formation assay, flow cytometry, and TUNEL staining, as well as the detection of apoptosis and anoikis resistance-related markers was applied to evaluate the anoikis-resistant capability of NPC cells cultured in ultra-low adhesion condition. Co-immunoprecipitation (Co-IP) experiment was performed to determine the interaction among LMP1, PRMT1 and PGC-1α. Ex vivo ubiquitination assay was used to detect the ubiquitination level of PGC-1α. Anoikis- resistant LMP1-positive NPC cell lines were established and applied for the xenograft and metastatic animal experiments. RESULTS: Our current findings reveal the role of LMP1-stabilized peroxisome proliferator activated receptor coactivator-1a (PGC-1α) in anoikis resistance and immune escape to support the invasion and metastasis of NPC. Mechanistically, LMP1 enhances PGC-1α protein stability by promoting the interaction between arginine methyltransferase 1 (PRMT1) and PGC-1α to elevate the methylation modification of PGC-1α, thus endowing NPC cells with anoikis-resistance. Meanwhile, PGC-1α mediates the immune escape induced by LMP1 by coactivating with STAT3 to transcriptionally up-regulate PD-L1 expression. CONCLUSION: Our work provides insights into how virus-encoded proteins recruit and interact with host regulatory elements to facilitate the malignant progression of NPC. Therefore, targeting PGC-1α or PRMT1-PGC-1α interaction might be exploited for therapeutic gain for EBV-associated malignancies.

A Novel Role of Connective Tissue Growth Factor in the Regulation of the Epithelial Phenotype.

BACKGROUND: Epithelial-mesenchymal transition (EMT) is a biological process where epithelial cells lose their adhesive properties and gain invasive, metastatic, and mesenchymal properties. Maintaining the balance between the epithelial and mesenchymal stage is essential for tissue homeostasis. Many of the genes promoting mesenchymal transformation have been identified; however, our understanding of the genes responsible for maintaining the epithelial phenotype is limited. Our objective was to identify the genes responsible for maintaining the epithelial phenotype and inhibiting EMT. METHODS: RNA seq was performed using an vitro model of EMT. CTGF expression was determined via qPCR and Western blot analysis. The knockout of CTGF was completed using the CTGF sgRNA CRISPR/CAS9. The tumorigenic potential was determined using NCG mice. RESULTS: The knockout of CTGF in epithelial ovarian cancer cells leads to the acquisition of functional characteristics associated with the mesenchymal phenotype such as anoikis resistance, cytoskeleton remodeling, increased cell stiffness, and the acquisition of invasion and tumorigenic capacity. CONCLUSIONS: We identified CTGF is an important regulator of the epithelial phenotype, and its loss is associated with the early cellular modifications required for EMT. We describe a novel role for CTGF, regulating cytoskeleton and the extracellular matrix interactions necessary for the conservation of epithelial structure and function. These findings provide a new window into understanding the early stages of mesenchymal transformation.

How do prolonged anchorage-free lifetimes strengthen non-small-cell lung cancer cells to evade anoikis? - A link with altered cellular metabolomics.

BACKGROUND: Malignant cells adopt anoikis resistance to survive anchorage-free stresses and initiate cancer metastasis. It is still unknown how varying periods of anchorage loss contribute to anoikis resistance, cell migration, and metabolic reprogramming of cancerous cells. RESULTS: Our study demonstrated that prolonging the anchorage-free lifetime of non-small-cell lung cancer NCI-H460 cells for 7 days strengthened anoikis resistance, as shown by higher half-life and capability to survive and grow without anchorage, compared to wild-type cells or those losing anchorage for 3 days. While the prolonged anchorage-free lifetime was responsible for the increased aggressive feature of survival cells to perform rapid 3-dimensional migration during the first 3 h of a transwell assay, no significant influence was observed with 2-dimensional surface migration detected at 12 and 24 h by a wound-healing method. Metabolomics analysis revealed significant alteration in the intracellular levels of six (oxalic acid, cholesterol, 1-ethylpyrrolidine, 1-(3-methylbutyl)-2,3,4,6-tetramethylbenzene, ß-alanine, and putrescine) among all 37 identified metabolites during 7 days without anchorage. Based on significance values, enrichment ratios, and impact scores of all metabolites and their associated pathways, three principal metabolic activities (non-standard amino acid metabolism, cell membrane biosynthesis, and oxidative stress response) offered potential links with anoikis resistance. CONCLUSIONS: These findings further our insights into the evolution of anoikis resistance in lung cancer cells and identify promising biomarkers for early lung cancer diagnosis.

Anoikis resistance--protagonists of breast cancer cells survive and metastasize after ECM detachment.

Breast cancer exhibits the highest global incidence among all tumor types. Regardless of the type of breast cancer, metastasis is a crucial cause of poor prognosis. Anoikis, a form of apoptosis initiated by cell detachment from the native environment, is an outside-in process commencing with the disruption of cytosolic connectors such as integrin-ECM and cadherin-cell. This disruption subsequently leads to intracellular cytoskeletal and signaling pathway alterations, ultimately activating caspases and initiating programmed cell death. Development of an anoikis-resistant phenotype is a critical initial step in tumor metastasis. Breast cancer employs a series of stromal alterations to suppress anoikis in cancer cells. Comprehensive investigation of anoikis resistance mechanisms can inform strategies for preventing and regressing metastatic breast cancer. The present review first outlines the physiological mechanisms of anoikis, elucidating the alterations in signaling pathways, cytoskeleton, and protein targets that transpire from the outside in upon adhesion loss in normal breast cells. The specific anoikis resistance mechanisms induced by pathological changes in various spatial structures during breast cancer development are also discussed. Additionally, the genetic loci of targets altered in the development of anoikis resistance in breast cancer, are summarized. Finally, the micro-RNAs and targeted drugs reported in the literature concerning anoikis are compiled, with keratocin being the most functionally comprehensive. Video Abstract.