System analysis based on Anoikis-related genes identifies MAPK1 as a novel therapy target for osteosarcoma with neoadjuvant chemotherapy.

BACKGROUND: Osteosarcoma (OS) is the most common bone malignant tumor in children, and its prognosis is often poor. Anoikis is a unique mode of cell death.However, the effects of Anoikis in OS remain unexplored. METHOD: Differential analysis of Anoikis-related genes was performed based on the metastatic and non-metastatic groups. Then LASSO logistic regression and SVM-RFE algorithms were applied to screen out the characteristic genes. Later, Univariate and multivariate Cox regression was conducted to identify prognostic genes and further develop the Anoikis-based risk score. In addition, correlation analysis was performed to analyze the relationship between tumor microenvironment, drug sensitivity, and prognostic models. RESULTS: We established novel Anoikis-related subgroups and developed a prognostic model based on three Anoikis-related genes (MAPK1, MYC, and EDIL3). The survival and ROC analysis results showed that the prognostic model was reliable. Besides, the results of single-cell sequencing analysis suggested that the three prognostic genes were closely related to immune cell infiltration. Subsequently, aberrant expression of two prognostic genes was identified in osteosarcoma cells. Nilotinib can promote the apoptosis of osteosarcoma cells and down-regulate the expression of MAPK1. CONCLUSIONS: We developed a novel Anoikis-related risk score model, which can assist clinicians in evaluating the prognosis of osteosarcoma patients in clinical practice. Analysis of the tumor immune microenvironment and chemotherapeutic drug sensitivity can provide necessary insights into subsequent mechanisms. MAPK1 may be a valuable therapeutic target for neoadjuvant chemotherapy in osteosarcoma.

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.

Muscone restores anoikis sensitivity in TMZ-resistant glioblastoma cells by suppressing TOP2A via the EGFR/Integrin ß1/FAK signaling pathway.

BACKGROUND: Temozolomide (TMZ) resistance is the main obstacle faced by glioblastoma multiforme (GBM) treatment. Muscone, one of the primary active pharmacological ingredients of Shexiang (Moschus), can cross the blood-brain barrier (BBB) and is being investigated as an antineoplastic medication. However, muscone treatment for GBM has received little research, and its possible mechanisms are still unclear. PURPOSE: This study aims to evaluate the effect and the potential molecular mechanism of muscone on TMZ-resistant GBM cells. METHODS: The differentially expressed genes (DEGs) between TMZ-resistant GBM cells and TMZ-sensitive GBM cells were screened using GEO2R. By progressively raising the TMZ concentration, a relatively stable TMZ-resistant human GBM cell line was established. The drug-resistance traits of U251-TR cells were assessed via the CCK-8 assay and Western Blot analysis of MGMT and TOP2A expression. Cell viability, cell proliferation, cell migration ability, and drug synergism were detected by the CCK-8 assay, colony formation assay, wound healing assay, and drug interaction relationship test, respectively. Anoikis was quantified by Calcein-AM/EthD-1 staining, MTT assay, and flow cytometry. Measurements of cell cycle arrest, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were performed using cell cycle staining, Annexin V-FITC/PI labeling, JC-1 assay, and ROS assay, respectively. DNA damage was measured by TUNEL assay, alkaline comet assay, and γ-H2AX foci assay. GEPIA was used to investigate the link between the anoikis marker (FAK)/drug resistance gene and critical proteins in the EGFR/Integrin ß1 signaling pathway. Molecular docking was used to anticipate the probable targets of muscone. The intracellular co-localization and expression of EGFR and FAK were shown using immunofluorescence. The U251-TR cell line stably overexpressing EGFR was constructed using lentiviral transduction to assess the involvement of EGFR-related signaling in anoikis resistance. Western Blot was employed to detect the expression of migration-related proteins, cyclins, anoikis-related proteins, DNA damage/repair-related proteins, and associated pathway proteins. RESULTS: DEGs analysis identified 97 deregulated chemotherapy-resistant genes and 3779 upregulated genes in TMZ-resistant GBM cells. Subsequent experiments verified TMZ resistance and the hyper-expression of DNA repair-related genes (TOP2A and MGMT) in continuously low-dose TMZ-induced U251-TR cells. Muscone exhibited dose-dependent inhibition of U251-TR cell migration and proliferation, and its co-administration with TMZ showed the potential for enhanced therapeutic efficacy. By downregulating FAK, muscone reduced anoikis resistance in anchorage-independent U251-TR cells. It also caused cell cycle arrest in the G2/M phase by upregulating p21 and downregulating CDK1, CDK2, and Cyclin E1. Muscone-induced anoikis was accompanied by mitochondrial membrane potential collapse, ROS production, an increase in the BAX/Bcl-2 ratio, as well as elevated levels of Cytochrome c (Cyt c), cleaved caspase-9, and cleaved caspase-3. These findings indicated that muscone might trigger mitochondrial-dependent anoikis via ROS generation. Moreover, significant DNA damage, DNA double-strand breaks (DSBs), the formation of γ-H2AX foci, and a reduction in TOP2A expression are also associated with muscone-induced anoikis. Overexpression of EGFR in U251-TR cells boosted the expression of Integrin ß1, FAK, ß-Catenin, and TOP2A, whereas muscone suppressed the expression levels of EGFR, Integrin ß1, ß-Catenin, FAK, and TOP2A. Muscone may influence the expression of the key DNA repair enzyme, TOP2A, by suppressing the EGFR/Integrin ß1/FAK pathway. CONCLUSION: We first demonstrated that muscone suppressed TOP2A expression through the EGFR/Integrin ß1/FAK pathway, hence restoring anoikis sensitivity in TMZ-resistant GBM cells. These data suggest that muscone may be a promising co-therapeutic agent for enhancing GBM treatment, particularly in cases of TMZ-resistant GBM with elevated TOP2A expression.

A novel anoikis-related signature predicts prognosis risk and treatment responsiveness in diffuse large B-cell lymphoma.

BACKGROUND: Although anoikis plays a role in cancer metastasis and aggressiveness, it has rarely been reported in diffuse large B cell lymphoma (DLBCL). METHODS: We obtained RNA sequencing data and matched clinical data from the GEO database. An anoikis-related genes (ARGs)-based risk signature was developed in GSE10846 training cohort and validated in three other cohorts. Additionally, we predicted half-maximal inhibitory concentration (IC50) of drugs based on bioinformatics method and obtained the actual IC50 to some chemotherapy drugs via cytotoxicity assay. RESULTS: The high-risk group, as determined by our signature, was associated with worse prognosis and an immunosuppressive environment in DLBCL. Meanwhile, the nomogram based on eight variables had more accurate ability in forecasting the prognosis than the international prognostic index in DLBCL. The prediction of IC50 indicated that DLBCL patients in the high-risk group were more sensitive to doxorubicin, IPA-3, lenalidomide, gemcitabine, and CEP.701, while patients in the low-risk group were sensitive to cisplatin and dasatinib. Consistent with the prediction, cytotoxicity assay suggested the higher sensitivity to doxorubicin and gemcitabine and the lower sensitivity to dasatinib in the high-risk group in DLBCL. CONCLUSION: The ARG-based signature may provide a promising direction for prognosis prediction and treatment optimization for DLBCL patients.

Parkin Enhances Gefitinib-induced Anoikis in HeLa Cervical Cancer Cells.

BACKGROUND/AIM: Gefitinib exhibits anticancer activity against cervical cancer cells via anoikis, a type of apoptosis induced by cell detachment from the extracellular matrix. Previous studies have reported that Parkin expression affects the efficacy of anticancer drugs. However, the impact of Parkin expression on the therapeutic effects of gefitinib in human cervical cancer remains unclear. Thus, this study aimed to evaluate whether Parkin over-expression improves the therapeutic effects of gefitinib against HeLa cervical cancer cells. MATERIALS AND METHODS: Cell viability and apoptotic death of HeLa cells were measured by trypan blue dye exclusion assay and flow cytometry. Cell detachment, adhesion, spreading, and cell-cell interaction were observed by inverted microscopy. Alteration of adhesion-related molecules was evaluated by confocal microscopy and western blot assay. RESULTS: Parkin expression potentiated gefitinib-induced cell detachment by affecting the organization of the actin cytoskeleton. In addition, Parkin expression induced a further reduction in the reattachment of and interaction between detached cells. The therapeutic efficacy of low-dose gefitinib combined with Parkin expression was equivalent to that of high-dose gefitinib alone. CONCLUSION: Parkin expression promotes gefitinib-induced anoikis, consequently increasing the efficacy of gefitinib against HeLa human cervical cancer cells. Based on our results, we propose that Parkin can be used to increase the anti-cancer effect of gefitinib on cervical cancer cells.

Synergistic effects of photodynamic therapy and chemotherapy: Activating the intrinsic/extrinsic apoptotic pathway of anoikis for triple-negative breast cancer treatment.

Triple-negative breast cancer (TNBC) is a highly invasive and metastatic subtype of breast cancer that often recurs after surgery. Herein, we developed a cyclodextrin-based tumor-targeted nano delivery system that incorporated the photosensitizer chlorin e6 (Ce6) and the chemotherapeutic agent lonidamine (LND) to form the R6RGD-CMßCD-se-se-Ce6/LND nanoparticles (RCC/LND NPS). This nanosystem could target cancer cells, avoid lysosomal degradation and further localize within the mitochondria. The RCC/LND NPS had pH and redox-responsive to control the release of Ce6 and LND. Consequently, the nanosystem had a synergistic effect by effectively alleviating hypoxia, enhancing the production of cytotoxic reactive oxygen species (ROS) and amplifying the efficacy of photodynamic therapy (PDT). Furthermore, the RCC/LND NPS + light weakened anoikis resistance, disrupted extracellular matrix (ECM), activated both the intrinsic apoptotic pathway (mitochondrial pathway) and extrinsic apoptotic pathway (receptor death pathway) of anoikis. In addition, the nanosystem showed significant anti-TNBC efficacy in vivo. These findings collectively demonstrated that RCC/LND NPS + light enhanced the anticancer effects, induced anoikis and inhibited tumor cell migration and invasion through a synergistic effect of chemotherapy and PDT. Overall, this study highlighted the promising potential of the RCC/LND NPS + light for the treatment of TNBC.

Lysophosphatidylcholine disrupts cell adhesion and induces anoikis in hepatocytes.

Lysophosphatidylcholine (LPC), the active metabolite of palmitate, triggers hepatocyte death by activating endoplasmic reticulum stress and JNK signalling-mediated lipoapoptosis. However, LPC-induced cytotoxicity in hepatocytes is not well understood. Here, we found for the first time that LPC-induced cell rounding occurred prior to apoptosis. LPC-induced rounding of cells reduced both cell-extracellular matrix (ECM) adhesion and cell-cell junctions, which promoted detachment-induced apoptosis (defined as anoikis) in hepatocytes. Further study revealed that LPC altered cellular morphology and cell adhesion by inhibiting integrin and cadherin signalling-mediated microfilament polymerization. We also found that ECM supplementation and microfilament cytoskeletal stabilization inhibited LPC-induced hepatocyte death by attenuating anoikis. Our data indicate a novel cytotoxic process and signalling pathway induced by LPC.

Cadmium induced Fak -mediated anoikis activation in kidney via nuclear receptors (AHR/CAR/PXR)-mediated xenobiotic detoxification pathway.

Cadmium (Cd) is a toxic heavy metal of considerable toxicity, possessing a serious environmental problem that threatening food safety and human health. However, the underlying mechanisms of Cd-induced nephrotoxicity and detoxification response remain largely unclear. Cd was administered at doses of 35, 70, and 140 mg/kg diet with feed for 90 days and produced potential damage to chickens' kidneys. The results showed that Cd exposure induced renal anatomical and histopathological injuries. Cd exposure up-regulated cytochrome P450 enzymes (CYP450s), activated nuclear xenobiotic receptors (NXRs) response, including aryl hydro-carbon receptor (AHR), constitutive androstane receptor (CAR), and pregnane X receptor (PXR) by low and moderate doses of Cd, and induced an increase in CYP isoforms expression. Cd exposure down-regulated phase II detoxification enzymes (glutathione-S-transferase (GST), glutathione peroxidase (GSH-PX) activities, and glutathione (GSH) content), and GST isoforms transcription . Furthermore, ATP-binding cassette (ABC) transporters, multidrug resistance protein (MRP1), and P-glycoprotein (P-GP) levels were elevated by low dose, but high dose inhibited the P-GP expression. Activation of detoxification enzymes lost their ability of resistance as increasing dose of Cd, afterwards brought into severe renal injury. Additionally, Cd suppressed focal adhesion kinase (Fak) and integrins protein expression as well as activated extrinsic pathway and intrinsic pathways, thereby producing anoikis. In conclusion, these results indicated that Cd induced Fak-mediated anoikis activation in the kidney via nuclear receptors (AHR/CAR/PXR)-mediated xenobiotic detoxification pathway.

The emerging role of miR-200 family in metastasis: focus on EMT, CSCs, angiogenesis, and anoikis.

INTRODUCTION: Cancer is the second major threat to human society and one of the main challenges facing healthcare systems. One of the main problems of cancer care is the metastases of cancer cells that cause 90% of deaths due to cancer. Multiple molecular mechanisms are involved in cancer cell metastasis. Therefore, a better understanding of these molecular mechanisms is necessary for designing restrictive strategies against cancer cell metastasis. Accumulating data suggests that MicroRNAs (miRNAs) are involved in metastasis and invasion of human tumors through regulating multiple genes expression levels that are involved in molecular mechanisms of metastasis. The goal of this review is to present the molecular pathways by which the miR 200 family manifests its effects on EMT, cancer stem cells, angiogenesis, anoikis, and the effects of tumor cell metastases. METHODS: A detailed literature search was conducted to find information about the role of the miR-200 family in the processes involved in metastasis in various databases. RESULTS: Numerous lines of evidence revealed an association between the mir-200 family and metastasis of human tumors by impressing processes such as cancer stem cells, EMT, angiogenesis, and anoikis. CONCLUSIONS: Understanding the molecular mechanisms associated with metastasis in which the miR-200 family is involved can be effective in treating metastatic cancers.

Epoxyazadiradione induced apoptosis/anoikis in triple-negative breast cancer cells, MDA-MB-231, by modulating diverse cellular effects.

Triple-negative breast cancer (TNBC) is one of the most aggressive forms of its kind, which accounts for 15-20% of all breast cancers. As this cancer form lacks hormone receptors, targeted chemotherapy remains the best treatment option. Apoptosis and anoikis (detachment-induced cell death) induction by small molecules can prevent TNBC metastasis to a greater extent. Epoxyazadiradione (EAD) is a limonoid from the neem plant with an anticancer property. Here, we demonstrate that EAD induced mitochondria-mediated apoptosis and anoikis in TNBC cells (MDA-MB-231). Apart from this, it promotes antimigration, inhibition of colony formation, downregulation of MMP-9 and fibronectin, induction of G2/M phase arrest with downregulation of cyclin A2/cdk2, interference in cellular metabolism, and inhibition of nuclear factor kappa-B (NF-kB) nuclear translocation. Moreover, a significant reduction is observed in the expression of EGFR on the plasma membrane and nucleus upon treatment with EAD. Among the diverse cellular effects, anoikis induction, metabolic interference, and downregulation of membrane/nuclear EGFR expression by EAD are reported here for the first time. To summarize, EAD targets multiple cellular events to induce growth arrest in TNBC, and hence can be developed into the best antineoplastic agent in the future.

Ursolic acid induces apoptosis and anoikis in colorectal carcinoma RKO cells.

BACKGROUND: Ursolic acid (UA) is an anti-cancer herbal compound. In the present study, we observed the effects of UA on anchorage-dependent and -independent growth of human colorectal cancer (CRC) RKO cells. METHODS: RKO cells were cultured in conventional and detached condition and treated with UA. Cell viability was evaluated by CCK-8 assay. Cell cycle was analyzed by flow cytometry. Apoptosis was identified by Hoechst 33258 staining and flow cytometry analysis. Activities of caspases were measured by commercial kits. Reactive oxygen species (ROS) was recognized by DCFH-DA fluorescent staining. Anoikis was identified by EthD-1 fluorescent staining and flow cytometry analysis. Expression and phosphorylation of proteins were analyzed by western blot. RESULTS: UA inhibited RKO cell viability in both a dose- and time-dependent manner. UA arrested the cell cycle at the G0/G1 phase, and induced caspase-dependent apoptosis. UA inhibited Bcl-2 expression and increased Bax expression. In addition, UA up-regulated the level of ROS that contributed to UA activated caspase-3, - 8 and - 9, and induced apoptosis. Furthermore, UA inhibited cell growth in a detached condition and induced anoikis in RKO cells that was accompanied by dampened phosphorylation of FAK, PI3K and AKT. UA also inhibited epithelial-mesenchymal transition (EMT) as indicated by the down-regulation of N-Cad expression and up-regulation of E-Cad expression. CONCLUSIONS: UA induced caspase-dependent apoptosis, and FAK/PI3K/AKT singling and EMT related anoikis in RKO cells. UA was an effective anti-cancer compound against both anchorage-dependent and -independent growth of RKO cells.

Kallistatin Inhibits Anoikis Resistance and Metastasis of Ectopic Endometrium Cells by Modulating MnSOD and Caspase 3 Signaling.

Endometriosis (EM) is a disease that involves active endometrial cell invasion and migration which is an important reason for infertility. Anoikis resistance is the most important prerequisite for EM, but the molecular mechanism is not yet clear. Kallistatin (KS) is one kind of serine protease inhibitors which had extensive biological function including anti-inflammatory, antioxidant stress, anti-angiogenesis, and anti-tumor. Our preliminary data showed that the level of KS in EM patients' endometrial tissue and blood were much lower than control (non-EM) patients without endometriosis. Interestingly, the decrease of KS is correlated with the severity of endometriosis. Moreover, kallistatin recombinant protein could increase the anoikis rate of ectopic endometrium cells (EESCs), and then inhibits its metastasis and invasion. Mechanically, our data show that the EESCs have lower intracellular reactive oxygen species (ROS) production and KS can elevate the ROS levels significantly. Further, KS modulate expression of MnSOD and caspase 3 signaling in EESCs grown in suspended conditions. These findings reveal novel mechanisms of KS in inducing anoikis and metastasis in EESCs, thus inhibiting EM progression by regulation of MnSOD and caspase 3 signaling. Our findings suggest that KS is a significant protein with prospects for application in EM.

Platelet­derived growth factor­BB mediates pancreatic cancer malignancy via regulation of the Hippo/Yes­associated protein signaling pathway.

Platelet­derived growth factor (PDGF) is a potent mitogen and chemoattractant that serves a role in the development of several types of solid cancer, and abnormal PDGF activity has been reported in numerous human tumors. Tumor­derived PDGF ligands are considered to act in either a paracrine or autocrine manner, serving roles in the phosphorylation of receptors on tumor and stromal cells in the tumor microenvironment. Despite the well­established association between PDGF and tumor progression, the precise mechanisms of autocrine PDGF signaling in pancreatic tumor cells remain elusive. Therefore, the present study aimed to analyze the influence of PDGF­BB in pancreatic cancer. Pancreatic adenocarcinoma BxPC­3 cells were cultured and treated with recombinant human PDGF­BB in vitro. Cell proliferation was tested using an MTT assay. Cell apoptosis was measured using flow cytometry. Tumor cell migration and invasion were examined via wound­healing and Transwell assays, respectively. The expression and subcellular localization of Yes­associated protein (YAP) was determined using western blotting and immunofluorescence. The transcriptional activity of target genes was tested using a luciferase assay and reverse transcription­quantitative PCR. The present study revealed that PDGF­BB significantly promoted cell proliferation in pancreatic adenocarcinoma BxPC­3 cells and enhanced the aggressiveness of this cell line, as demonstrated by Transwell and wound­healing assays. Anoikis resistance is an important mechanism by which metastatic cells avoid apoptosis when detaching from adjacent cells or the extracellular matrix. PDGF­BB treatment inhibited anoikis under anchorage­independent conditions. Mechanistic experiments revealed that PDGF­BB promoted the upregulation and activation of the transcriptional coactivator YAP, an effector of the Hippo signaling pathway. RhoA or protein phosphatase­1 (PP­1) inhibition partially abolished the accumulation and activation of YAP, suggesting PDGF­BB­mediated YAP dephosphorylation and transactivation via the RhoA/PP­1 cascade. Pharmacologic inhibition of the PDGF receptor directly downregulated YAP activity and the expression levels of downstream genes. Furthermore, verteporfin, a small molecular inhibitor of the Hippo/YAP signaling pathway, partially reversed the effects of PDGF­BB on cell proliferation, anoikis resistance and cell migration. In conclusion, the present study revealed that the Hippo/YAP signaling pathway may be involved in the tumor­promoting activity of PDGF­BB in pancreatic cancer.

Jinfukang regulates integrin/Src pathway and anoikis mediating circulating lung cancer cells migration.

ETHNOPHARMACOLOGICAL RELEVANCE: Metastasis is the main cause of death in lung cancer patients. Circulating tumor cells (CTCs) may be an important target of metastasis intervention. Previous studies have shown that Jinfukang could prevent the recurrence and metastasis of lung cancer, and we have established a circulating lung tumor cell line CTC-TJH-01. However, whether Jinfukang inhibition of lung cancer metastasis is related to CTCs is still unknown. AIM OF THE STUDY: To further explore the mechanism of Jinfukang in anti-metastasis of lung cancer from the perspective of intervention of CTCs. MATERIALS AND METHODS: CTC-TJH-01 and H1975 cells were treated with Jinfukang. Cell viability was detected by CCK8, and the cell apoptosis was detected by flow cytometry. Transwell was used to detected cell migration and invasion. Cell anoikis was detected by anoikis detection kit. Protein expression was analysis by Western blot. RESULTS: Jinfukang could inhibit the proliferation, migration and invasion of CTC-TJH-01 and H1975 cells. Besides, Jinfukang could also induce anoikis in CTC-TJH-01 and H1975 cells. Analysis of the mRNA expression profile showed ECM-receptor interaction and focal adhesion were regulated by Jinfukang. Moreover, it was also find that Jinfukang significantly inhibited integrin/Src pathway in CTC-TJH-01 and H1975 cells. When suppress the expression of integrin with ATN-161, it could promote Jinfukang to inhibit migration and induce anoikis in CTC-TJH-01 and H1975 cells. CONCLUSIONS: Our results indicate that the migration and invasion of CTCs are inhibited by Jinfukang, and the mechanism may involve the suppression of integrin/Src axis to induce anoikis. These data suggest that Jinfukang exerts anti-metastatic effects in lung cancer may through anoikis.

Implication of integrins α3ß1 and α5ß1 in invasion and anoikis of SK-Mel-147 human melanoma cells: non-canonical functions of protein kinase Akt.

Downregulation of integrins α3ß1 and α5ß1 strongly decreased cell colony formation and in vitro invasion and markedly enhanced anoikis in SK-Mel-147 human melanoma cells. These modifications were accompanied by a marked increase in the levels of active Akt protein kinase, which indicated it played a non-canonical function in the melanoma cells. Pharmacological inhibition of Akt1, an Akt isozyme, in cells depleted of α3ß1 or α5ß1 restored their invasive activity, while inhibition of the Akt 2 isoform did not cause a visible effect. Similar to our previous results with the α2ß1 integrin, this finding suggested that in signaling pathways initiated by α3ß1 and α5ß1, the Akt1 isoform performs a non-canonical function in regulating invasive phenotype of melanoma cells. In contrast, when the effects of Akt inhibitors on anoikis of the melanoma cells were compared, the Akt2 isoform demonstrated a non-canonical activity in which Akt2 suppression led to a significant attenuation of apoptosis in cells with downregulated α3ß1 or α5ß1. Our results were the first evidence that, in the same tumor cells, different integrins can control various manifestations of tumor progression through distinct signaling pathways that are both common to various integrins and specific to a particular receptor.

Pygenic Acid A (PA) Sensitizes Metastatic Breast Cancer Cells to Anoikis and Inhibits Metastasis In Vivo.

Metastasis is the main cause of cancer-related deaths. Anoikis is a type of apoptosis caused by cell detachment, and cancer cells become anoikis resistant such that they survive during circulation and can successfully metastasize. Therefore, sensitization of cancer cells to anoikis could prevent metastasis. Here, by screening for anoikis sensitizer using natural compounds, we found that pygenic acid A (PA), a natural compound from Prunella vulgaris, not only induced apoptosis but also sensitized the metastatic triple-negative breast cancer cell lines, MDA-MB-231 cells (human) and 4T1 cells (mouse), to anoikis. Apoptosis protein array and immunoblotting analysis revealed that PA downregulated the pro-survival proteins, including cIAP1, cIAP2, and survivin, leading to cell death of both attached and suspended cells. Interestingly, PA decreased the levels of proteins associated with anoikis resistance, including p21, cyclin D1, p-STAT3, and HO-1. Ectopic expression of active STAT3 attenuated PA-induced anoikis sensitivity. Although PA activated ER stress and autophagy, as determined by increases in the levels of characteristic markers, such as IRE1α, p-elF2α, LC3B I, and LC3B II, PA treatment resulted in p62 accumulation, which could be due to PA-induced defects in autophagy flux. PA also decreased metastatic characteristics, such as cell invasion, migration, wound closure, and 3D growth. Finally, lung metastasis of luciferase-labeled 4T1 cells decreased following PA treatment in a syngeneic mouse model when compared with the control. These data suggest that PA sensitizes metastatic breast cancer cells to anoikis via multiple pathways, such as inhibition of pro-survival pathways and activation of ER stress and autophagy, leading to the inhibition of metastasis. These findings suggest that sensitization to anoikis by PA could be used as a new therapeutic strategy to control the metastasis of breast cancer.

Intrahepatic metastases may be specific to hepatocellular carcinoma due to the coagulation and fibrinolytic systems (Review).

Hepatocellular carcinoma (HCC) is different from other solid tumors because it is commonly associated with the occurrence of intrahepatic metastasis. Additionally, the liver, unlike other organs, is the main site of coagulation and fibrinolytic factor production. Therefore, it was speculated that coagulation and fibrinolytic factors could be associated with intrahepatic metastasis of HCC. Do the coagulation and fibrinolytic systems protect HCC cells against anoikis during infiltration and metastasis? Conversely, do the coagulation and fibrinolytic systems lead to immune escape of HCC cells by affecting the immune microenvironment of patients? The current review aimed to present a number of novel hypotheses for the treatment of HCC by exploring the mechanisms of coagulation and fibrinolytic factors in the regulation of cancer growth.

Targeting an autocrine IL-6-SPINK1 signaling axis to suppress metastatic spread in ovarian clear cell carcinoma.

A major clinical challenge of ovarian cancer is the development of malignant ascites accompanied by widespread peritoneal metastasis. In ovarian clear cell carcinoma (OCCC), a challenging subtype of ovarian cancer, this problem is compounded by near-universal primary chemoresistance; patients with advanced stage OCCC thus lack effective therapies and face extremely poor survival rates. Here we show that tumor-cell-expressed serine protease inhibitor Kazal type 1 (SPINK1) is a key driver of OCCC progression and metastasis. Using cell culture models of human OCCC, we find that shRNA silencing of SPINK1 sensitizes tumor cells to anoikis and inhibits proliferation. Knockdown of SPINK1 in OCCC cells also profoundly suppresses peritoneal metastasis in mouse implantation models of human OCCC. We next identify a novel autocrine signaling axis in OCCC cells whereby tumor-cell-produced interleukin-6 (IL-6) regulates SPINK1 expression to stimulate a common protumorigenic gene expression pattern leading to anoikis resistance and proliferation of OCCC cells. We further demonstrate that this signaling pathway can be successfully interrupted with the IL-6Rα inhibitor tocilizumab, sensitizing cells to anoikis in vitro and reducing metastasis in vivo. These results suggest that clinical trials of IL-6 pathway inhibitors in OCCC may be warranted, and that SPINK1 might offer a candidate predictive biomarker in this population.

Curcumol Suppresses Triple-negative Breast Cancer Metastasis by Attenuating Anoikis Resistance via Inhibition of Skp2-mediated Transcriptional Addiction.

BACKGROUND/AIM: Triple-negative breast cancer (TNBC) is a unique subtype that lacks expression of several conventional biomarkers and has a higher incidence of lymph node invasion and distal metastasis among all breast cancers. Anoikis resistance is the fundamental reason behind tumor cells' survival without their attachment to the extracellular matrix and metastasis to distal organs. Therefore, finding novel anti-cancer drugs that can suppress anoikis resistance in cancer cells is critical for patients with TNBC. MATERIALS AND METHODS: Curcumol, a natural compound, was used to assess whether it can inhibit the anoikis resistance and affects cell mortality and motility of IV2-1 TNBC cells. RESULTS: Curcumol suppressed anoikis resistance and inhibited TNBC cell survival in suspension. Additionally, these anti-cancer effects induced by curcumol could be related to the YAP1/Skp2 molecular pathway. CONCLUSION: Curcumol is an effective Skp2-targeted therapy that attenuates anoikis resistance and metastasis in TNBC cells.