BNIP3 supports melanoma cell migration and vasculogenic mimicry by orchestrating the actin cytoskeleton

BNIP3-mediated mitophagy boosts the competitive growth of Lenvatinib-resistant cells via energy metabolism reprogramming in HCC

An increasing evidence supports that cell competition, a vital selection and quality control mechanism in multicellular organisms, is involved in tumorigenesis and development; however, the mechanistic contributions to the association between cell competition and tumor drug resistance remain ill-defined. In our study, based on a contructed lenvitinib-resistant hepatocellular carcinoma (HCC) cells display obvious competitive growth dominance over sensitive cells through reprogramming energy metabolism. Mechanistically, the hyperactivation of BCL2 interacting protein3 (BNIP3) -mediated mitophagy in lenvatinib-resistant HCC cells promotes glycolytic flux via shifting energy production from mitochondrial oxidative phosphorylation to glycolysis, by regulating AMP-activated protein kinase (AMPK) -enolase 2 (ENO2) signaling, which perpetually maintaining lenvatinib-resistant HCC cells' competitive advantage over sensitive HCC cells. Of note, BNIP3 inhibition significantly sensitized the anti-tumor efficacy of lenvatinib in HCC. Our findings emphasize a vital role for BNIP3-AMPK-ENO2 signaling in maintaining the competitive outcome of lenvitinib-resistant HCC cells via regulating energy metabolism reprogramming; meanwhile, this work recognizes BNIP3 as a promising target to overcome HCC drug resistance.

Bioinformatics Analysis and Experimental Validation of Mitochondrial Autophagy Genes in Knee Osteoarthritis

Background

Mitochondrial autophagy is closely related to the pathogenesis of osteoarthritis, In order to explore the role of mitochondrial autophagy related genes in knee osteoarthritis (KOA) and its molecular mechanism.

Methods

KOA-related transcriptome data were extracted from the Gene Expression Omnibus (GEO) database. Differentially expressed mitochondrial autophagy gene (DEMGs) were screened in patients with KOA by differential expression analysis. The STRING website was used to construct a protein-protein interaction (PPI) network among DEMGs. Molecular complex detection (MCODE) method in Cytoscape software was performed to identify hub DEMGs. Support vector machine recursive feature elimination (SVM-RFE) method was used to construct the hub DEMG diagnosis model. Genes with diagnostic value were identified as biomarkers by plotting receiver operating characteristic (ROC) curves and Expression validation. CIBERSORT algorithm was used to calculate the proportion of 22 immune cells in each sample in the GSE114007 dataset. Finally, biomarker expression was verified by qPCR.

Results

A total of 15 DEMGs were obtained and enrichment analyses showed that these DEMG strains were mainly enriched in the mitophagy-animal, shigellosis, autophagy-animal and FoxO signal pathways. The PPI network unveiled 13 DEMGs with interactions. In addition, 8 hub DEMGs (ULK1, CALCOCO2, MAP1LC3B, BNIP3L, GABARAPL1, BNIP3, FKBP8 and FOXO3) were obtained for KOA. And 5 model DEMGs (BNIP3L, BNIP3, MAP1LC3B, ULK1 and FOXO3) were screened. The ROC curves revealed that BNIP3 and FOXO3 has strong diagnostic value in these models of DEMG. Immune-infiltration and correlation analysis showed that BNIP3 and FOXO3 were significantly correlated with three different immune cells, including primary B cells, M0 macrophage and M2 macrophage. The cartilage tissue samples qPCR verification results show that FOXO3 and BNIP3 were all down-regulated in KOA (p < 0.01), and the validation results are consistent with the above analysis.

Conclusion

BNIP3 and FOXO3 have been identified as biomarkers for the diagnosis of KOA, which might supply a new insight for the pathogenesis and treatment of KOA.

Hypoxic microenvironment promotes dermal fibroblast migration and proliferation via a BNIP3-autophagy pathway

Upon injury, nearby cells, including fibroblasts at the wound edge, are often found in a hypoxic microenvironment. Nevertheless, the influence of hypoxia on skin fibroblasts is poorly understood. Using previously established mouse full-thickness wounds, we show that Bcl-2 and adenovirus E1B 19-kDa interacting protein 3 (BNIP3) expression was significantly elevated at the wound edge, and hypoxia treatment enhanced BNIP3 expression in fibroblasts. Interestingly, BNIP3 promoted the migration and proliferation, as well as the activation of autophagy, in fibroblasts under hypoxia. The hypoxia-induced autophagy was found to induce the migration and proliferation of fibroblasts, a process that could be reversed by knocking down the autophagy-related gene for autophagy protein 5, ATG5. Furthermore, hypoxia-inducible factor 1 subunit alpha (HIF-1α) was significantly upregulated in fibroblasts under hypoxia treatment, and HIF-1α knockdown attenuated the hypoxia-induced expression of BNIP3 and the migration and proliferation of fibroblasts. Altogether, our results establish the hypoxia-BNIP3-autophagy signaling axis as a newly identified regulatory mechanism of skin fibroblast migration and proliferation upon wounding. Autophagy intervening might thus represent a promising therapeutic strategy for patients with chronic refractory wounds.

Mitochondrial protein BNIP3 regulates Chikungunya virus replication in the early stages of infection

Chikungunya virus (CHIKV) is a human pathogen causing outbreaks of febrile illness for which vaccines and specific treatments remain unavailable. Autophagy-related (ATG) proteins and autophagy receptors are a set of host factors that participate in autophagy, but have also shown to function in other unrelated cellular pathways. Although autophagy is reported to both inhibit and enhance CHIKV replication, the specific role of individual ATG proteins remains largely unknown. Here, a siRNA screen was performed to evaluate the importance of the ATG proteome and autophagy receptors in controlling CHIKV infection. We observed that 7 out of 50 ATG proteins impact the replication of CHIKV. Among those, depletion of the mitochondrial protein and autophagy receptor BCL2 Interacting Protein 3 (BNIP3) increased CHIKV infection. Interestingly, BNIP3 controls CHIKV independently of autophagy and cell death. Detailed analysis of the CHIKV viral cycle revealed that BNIP3 interferes with the early stages of infection. Moreover, the antiviral role of BNIP3 was found conserved across two distinct CHIKV genotypes and the closely related Semliki Forest virus. Altogether, this study describes a novel and previously unknown function of the mitochondrial protein BNIP3 in the control of the early stages of the alphavirus viral cycle.

Transdermal delivery of brucine-encapsulated liposomes significantly enhances anti-tumor outcomes in treating triple-negative breast cancer

Triple-negative breast cancer (TNBC) is always the most challenging breast cancer subtype. Herein, brucine, encapsulated in peptide-modified liposomes, was proposed for treating TNBC by transdermal delivery. For the TD peptide-modified brucine-loaded liposome (Bru-TD-Lip) we developed, it presents high encapsulation efficiency of brucine and stability. In vitro, Bru-TD-Lip shows the enhanced percutaneous permeability of brucine, is able to readily enter TNBC cells, and significantly inhibits the proliferation, migration, and invasion of these cells. In vivo, through transdermal delivery, Bru-TD-Lip presents good biosafety and anti-tumor efficacy. The transdermal delivery of Bru-TD-Lip effectively targets and inhibits subcutaneous mammary carcinogenesis in female nude mice. Compared with oral administration, the transdermal delivery significantly reduces the damage of brucine to major organs and enhances the antitumor outcomes of brucine in treating TNBC. This study provides a new therapeutic strategy for treating triple-negative breast cancer by brucine.

Multifaceted roles of mitochondria in wound healing and chronic wound pathogenesis

Mitochondria are intracellular organelles that play a critical role in numerous cellular processes including the regulation of metabolism, cellular stress response, and cell fate. Mitochondria themselves are subject to well-orchestrated regulation in order to maintain organelle and cellular homeostasis. Wound healing is a multifactorial process that involves the stringent regulation of several cell types and cellular processes. In the event of dysregulated wound healing, hard-to-heal chronic wounds form and can place a significant burden on healthcare systems. Importantly, treatment options remain limited owing to the multifactorial nature of chronic wound pathogenesis. One area that has received more attention in recent years is the role of mitochondria in wound healing. With regards to this, current literature has demonstrated an important role for mitochondria in several areas of wound healing and chronic wound pathogenesis including metabolism, apoptosis, and redox signalling. Additionally, the influence of mitochondrial dynamics and mitophagy has also been investigated. However, few studies have utilised patient tissue when studying mitochondria in wound healing, instead using various animal models. In this review we dissect the current knowledge of the role of mitochondria in wound healing and discuss how future research can potentially aid in the progression of wound healing research.

Systematic review of comparative transcriptomic studies of cellular resistance to genotoxic stress

The development of resistance by tumor cells to various types of therapy is a significant problem that decreases the effectiveness of oncology treatments. For more than two decades, comparative transcriptomic studies of tumor cells with different sensitivities to ionizing radiation and chemotherapeutic agents have been conducted in order to identify the causes and mechanisms underlying this phenomenon. However, the results of such studies have little in common and often contradict each other. We have assumed that a systematic analysis of a large number of such studies will provide new knowledge about the mechanisms of development of therapeutic resistance in tumor cells. Our comparison of 123 differentially expressed gene (DEG) lists published in 98 papers suggests a very low degree of consistency between the study results. Grouping the data by type of genotoxic agent and tumor type did not increase the similarity. The most frequently overexpressed genes were found to be those encoding the transport protein ABCB1 and the antiviral defense protein IFITM1. We put forward a hypothesis that the role played by the overexpression of the latter in the development of resistance may be associated not only with the stimulation of proliferation, but also with the limitation of exosomal communication and, as a result, with a decrease in the bystander effect. Among down regulated DEGs, BNIP3 was observed most frequently. The expression of BNIP3, together with BNIP3L, is often suppressed in cells resistant to non-platinum genotoxic chemotherapeutic agents, whereas it is increased in cells resistant to ionizing radiation. These observations are likely to be mediated by the binary effects of these gene products on survival, and regulation of apoptosis and autophagy. The combined data also show that even such obvious mechanisms as inhibition of apoptosis and increase of proliferation are not universal but show multidirectional changes.

Targeting CD47 as a therapeutic strategy: A common bridge in the therapy of COVID-19-related cancers

Macrophages are essential mediators of innate immunity. Non-self-cells resist phagocytosis through the expression of the checkpoint molecule CD47. CD47, as the integrin-associated protein, is overexpressed on tumor and SARS-CoV-2-infected cells as a potential surface biomarker for immune surveillance evasion. CD47-signal-regulating protein alpha (SIRPα) interaction is a promising innate immunotarget. Previous findings based on monoclonal antibodies (mAbs) or fusion proteins that block CD47 or SIRPα have been developed in cancer research. While CD47 efficacy in infectious diseases, especially severe COVID-19 studies, is lacking, focus on macrophage-mediated immunotherapy that increases "eat me" signals in combination therapy with mAbs is optimistic. This integrin-related protein can be as a potential target to therapy for COVID-19. Here, we concentrate on the role of the CD47 signaling pathway as a novel therapeutic strategy for COVID-19-associated cancer treatment.

HIF-1α dependent RhoA as a novel therapeutic target to regulate rheumatoid arthritis fibroblast-like synoviocytes migration in vitro and in vivo

Objective

The purpose of this work is to investigate how the Rho family of GTPases A (RhoA) mediates the pathogenesis of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS).

Methods

The expression of RhoA in the synovial tissues of RA and Healthy people (Control) was detected using immunohistochemistry methods. The expression of RhoA and hypoxia-inducible factor-1α (HIF-1α) is inhibited by small interfering RNAs (siRNAs). The inhibition effect on RA-FLS migration was further investigated. The protein expression level of HIF-1α, RhoA, focal adhesion kinase (FAK), and myosin light chain (MLC) was also analysed using western blotting (WB). DBA1 mice were immunised with the mixture of bovine type II collagen and Freund's adjuvant to establish collagen induced arthritis (CIA) mouse model. Lip-siRhoA is administered through joint injection every two days. Micro-computed tomography (micro-CT) was used to detect mouse ankle joint destruction and evaluate the bone loss of the periarticular side. Destruction of the ankle articular cartilage was tested by histology. Expressions of P-RhoA, P-FAK and P-MLC in the ankle joint was detected by immunohistochemistry assay.

Results

The expression level of RhoA in the synovial tissues of RA patients was significantly higher than that in control group. Hypoxia was able to up-regulate the expression of RhoA. Whereas, HIF-1α siRNA (siHIF-1α) could down-regulate the expression of RhoA. Additionally, both of siHIF-1α and RhoA siRNA (siRhoA) delivered by liposome (Lip-siHIF-1α and Lip-siRhoA) were found to suppress FAK and MLC phosphorylation in vitro. In CIA mouse model, Lip-siRhoA was demonstrated to ameliorate the destruction of ankle joint and reduce the severity of ankle joint cartilage damage by micro-CT and histological staining, respectively. Therefore, inhibition of FLS cell migration can protect articular bone from destruction. Furthermore, the expression of P-RhoA, P-FAK and P-MLC was evaluated and found to be down-regulated by Lip-siRhoA in vivo.

Conclusion

The results demonstrated that under hypoxic environment, HIF-1α dependent RhoA pathway played an important role on cytoskeleton remodelling and RA-FLS migration. Through down-regulating RhoA expression, it could effectively treat RA in vitro and in vivo.

The translational potential of this article

Our study provides new evidence for the potential clinical application of RhoA as a candidate for the treatment of RA.

Cofilin promotes vasculogenic mimicry by regulating the actin cytoskeleton in human breast cancer cells

Vasculogenic mimicry (VM) is the formation of microvascular channels by cancer cells. VM requires cellular processes that are regulated by changes in cellular migration and morphology. Cofilin (CFL), a key regulator of actin depolymerization, has been reported to affect malignant phenotypes of cancer. We show that treatment with inhibitors of actin dynamics suppresses VM in MDA-MB-231 human breast cancer cells. We established CFL-knockout (KO) MDA-MB-231 cells and found that VM was attenuated in CFL-KO cells. Although the re-expression of wild-type CFL restored VM in CFL-KO cells, inactive phosphomimetic CFL failed to do so. Collectively, our results demonstrate that CFL is a critical regulator of VM and implicate CFL as a novel therapeutic target for breast cancer.

Mitochondrial plasticity supports proliferative outgrowth and invasion of ovarian cancer spheroids during adhesion

Background

Ovarian cancer cells aggregate during or after exfoliation from the primary tumor to form threedimensional spheroids. Spheroid formation provides a survival advantage during peritoneal dissemination in nutrient and oxygen-depleted conditions which is accompanied by a suppressed metabolic phenotype and fragmented mitochondria. Upon arrival to their metastatic sites, spheroids adhere to peritoneal organs and transition to a more epithelial phenotype to support outgrowth and invasion. In this study, we investigated the plasticity of mitochondrial morphology, dynamics, and function upon adhesion.

Methods

Using our slow-developing (MOSE-L) and fast-developing (MOSE-LTICv) ovarian cancer models, we mimicked adhesion and reoxygenation conditions by plating the spheroids onto tissue culture dishes and changing culture conditions from hypoxia and low glucose to normoxia with high glucose levels after adhesion. We used Western Blot, microscopy and Seahorse analyses to determine the plasticity of mitochondrial morphology and functions upon adhesion, and the impact on proliferation and invasion capacities.

Results

Independent of culture conditions, all spheroids adhered to and began to grow onto the culture plates. While the bulk of the spheroid was unresponsive, the mitochondrial morphology in the outgrowing cells was indistinguishable from cells growing in monolayers, indicating that mitochondrial fragmentation in spheroids was indeed reversible. This was accompanied by an increase in regulators of mitobiogenesis, PGC1a, mitochondrial mass, and respiration. Reoxygenation increased migration and invasion in both cell types but only the MOSE-L responded with increased proliferation to reoxygenation. The highly aggressive phenotype of the MOSE-LTICv was characterized by a relative independence of oxygen and the preservation of higher levels of proliferation, migration and invasion even in limiting culture conditions but a higher reliance on mitophagy. Further, the outgrowth in these aggressive cells relies mostly on proliferation while the MOSE-L cells both utilize proliferation and migration to achieve outgrowth. Suppression of proliferation with cycloheximide impeded aggregation, reduced outgrowth and invasion via repression of MMP2 expression and the flattening of the spheroids.

Discussion

Our studies indicate that the fragmentation of the mitochondria is reversible upon adhesion. The identification of regulatory signaling molecules and pathways of these key phenotypic alterations that occur during primary adhesion and invasion is critical for the identification of druggable targets for therapeutic intervention to prevent aggressive metastatic disease.

Comprehensive Analysis of Necroptosis-Related Genes as Prognostic Factors and Immunological Biomarkers in Breast Cancer

Breast cancer (BC) is a lethal malignancy with a poor prognosis. Necroptosis is critical in the progression of cancer. However, the expression of genes involved in necroptosis in BC and their association with prognosis remain unclear. We investigated the predictive potential of necroptosis-related genes in BC samples from the TCGA dataset. We used LASSO regression to build a risk model consisting of twelve necroptosis-related genes in BC. Using the necroptosis-related risk model, we were able to successfully classify BC patients into high- and low-risk groups with significant prognostic differences (p = 4.872 × 10 ^-7). Additionally, we developed a matched nomogram predicting 5, 7, and 10-year overall survival in BC patients based on this necroptosis-related risk model. Our next step was to perform multiple GSEA analyses to explore the biological pathways through which these necroptosis-related risk genes influence cancer progression. For these twelve risk model genes, we analyzed CNV, SNV, OS, methylation, immune cell infiltration, and drug sensitivity in pan-cancer. In addition, immunohistochemical data from the THPA database were used to validate the protein expression of these risk model genes in BC. Taken together, we believe that necroptosis-related genes are considered potential therapeutic targets in BC and should be further investigated.

Pharmacological targeting of the mitochondrial calcium-dependent potassium channel KCa3.1 triggers cell death and reduces tumor growth and metastasis in vivo

Ion channels are non-conventional, druggable oncological targets. The intermediate-conductance calcium-dependent potassium channel (K_Ca3.1) is highly expressed in the plasma membrane and in the inner mitochondrial membrane (mitoK_Ca3.1) of various cancer cell lines. The role mitoK_Ca3.1 plays in cancer cells is still undefined. Here we report the synthesis and characterization of two mitochondria-targeted novel derivatives of a high-affinity K_Ca3.1 antagonist, TRAM-34, which retain the ability to block channel activity. The effects of these drugs were tested in melanoma, pancreatic ductal adenocarcinoma and breast cancer lines, as well as in vivo in two orthotopic models. We show that the mitochondria-targeted TRAM-34 derivatives induce release of mitochondrial reactive oxygen species, rapid depolarization of the mitochondrial membrane, fragmentation of the mitochondrial network. They trigger cancer cell death with an EC₅₀ in the µM range, depending on channel expression. In contrast, inhibition of the plasma membrane K_Ca3.1 by membrane-impermeant Maurotoxin is without effect, indicating a specific role of mitoK_Ca3.1 in determining cell fate. At sub-lethal concentrations, pharmacological targeting of mitoK_Ca3.1 significantly reduced cancer cell migration by enhancing production of mitochondrial reactive oxygen species and nuclear factor-κB (NF-κB) activation, and by downregulating expression of Bcl-2 Nineteen kD-Interacting Protein (BNIP-3) and of Rho GTPase CDC-42. This signaling cascade finally leads to cytoskeletal reorganization and impaired migration. Overexpression of BNIP-3 or pharmacological modulation of NF-κB and CDC-42 prevented the migration-reducing effect of mitoTRAM-34. In orthotopic models of melanoma and pancreatic ductal adenocarcinoma, the tumors at sacrifice were 60% smaller in treated versus untreated animals. Metastasis of melanoma cells to lymph nodes was also drastically reduced. No signs of toxicity were observed. In summary, our results identify mitochondrial K_Ca3.1 as an unexpected player in cancer cell migration and show that its pharmacological targeting is efficient against both tumor growth and metastatic spread in vivo.

Characterization of Novel Derivatives of MBQ-167, an inhibitor of the GTP-binding proteins Rac/Cdc42

Rac and Cdc42, are homologous GTPases that regulate cell migration, invasion, and cell cycle progression; thus, representing key targets for metastasis therapy. We previously reported on the efficacy of MBQ-167, which blocks both Rac1 and Cdc42 in breast cancer cells and mouse models of metastasis. To identify compounds with increased activity, a panel of MBQ-167 derivatives was synthesized, maintaining its 9-ethyl-3-(1H-1,2,3-triazol-1-yl)-9H-carbazole core. Similar to MBQ-167, MBQ-168 and EHop-097, inhibit activation of Rac and Rac1B splice variant and breast cancer cell viability, and induce apoptosis. MBQ-167 and MBQ-168 inhibit Rac and Cdc42 by interfering with guanine nucleotide binding, and MBQ-168 is a more effective inhibitor of PAK (1,2,3) activation. EHop-097 acts via a different mechanism by inhibiting the interaction of the guanine nucleotide exchange factor (GEF) Vav with Rac. MBQ-168 and EHop-097 inhibit metastatic breast cancer cell migration, and MBQ-168 promotes loss of cancer cell polarity to result in disorganization of the actin cytoskeleton and detachment from the substratum. In lung cancer cells, MBQ-168 is more effective than MBQ-167 or EHop-097 at reducing ruffle formation in response to EGF. Comparable to MBQ-167, MBQ-168 significantly inhibits HER2+ tumor growth and metastasis to lung, liver, and spleen. Both MBQ-167 and MBQ-168 inhibit the cytochrome P450 (CYP) enzymes 3A4, 2C9, and 2C19. However, MBQ-168 is ~10X less potent than MBQ-167 at inhibiting CYP3A4, thus demonstrating its utility in relevant combination therapies. In conclusion, the MBQ-167 derivatives MBQ-168 and EHop-097 are additional promising anti metastatic cancer compounds with similar and distinct mechanisms.

LINC00461 Regulates the Recurrence of Large B Cell Lymphoma through the miR-411-5p/BNIP3 Pathway

Objective

To analyze the mechanism of LINC00461 regulating the recurrence of diffuse large B cell lymphoma (DLBCL) through microRNA (miR)-411-5p/BCL2 interacting protein 3 (BNIP3) pathway.

Methods

DLBCL samples in TCGA and GSE12453 were used for differential analysis to find long noncoding RNA (lncRNA) related to DLBCL recurrence. The 4 DLBCL data with the highest and lowest expression levels of LINC00461 in the TCGA database were selected for GSEA enrichment analysis. The targeting relationships of miR-411-5p with LINC00461 and BNIP3 were verified by the dual luciferase report. Blood samples from DLBCL patients were used to analyze the correlation between miR-411-5p and LINC00461 or BNIP3. LINC00461, miR-411-5p, or BNIP3 was overexpressed or silenced by transfection, and a tumor-bearing nude mice model was constructed to detect their effects on proliferation and apoptosis.

Results

The level of LINC00461 in DLBCL was significantly higher than that in normal cases, and the level in recurrence DLBCL was significantly higher than that in nonrecurrence. The enrichment analysis results showed that the function of LINC00461 was closely related to apoptosis. The results shown that miR-411-5p bound to LINC00461 and BNIP3 and was negatively correlated with LINC00461 and BNIP3 mRNA in blood of DLBCL patients. Suppressing the level of LINC00461 inhibited cell proliferation and induced apoptosis. The inhibition of LINC00461 or overexpression of miR-411-5p reduced the expression of BNIP3 protein, thereby inducing apoptosis at the in vivo and in vitro levels.

Conclusion

LINC00461 may induce miR-411-5p to “sponge,” thereby increasing the expression of BNIP3 protein, and exerting the function of inhibiting apoptosis and promoting DLBCL recurrence.

Scorpion Peptide Smp24 Exhibits a Potent Antitumor Effect on Human Lung Cancer Cells by Damaging the Membrane and Cytoskeleton In Vivo and In Vitro

Smp24, a cationic antimicrobial peptide identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus, shows variable cytotoxicity on various tumor (KG1a, CCRF-CEM and HepG2) and non-tumor (CD34⁺, HRECs, HACAT) cell lines. However, the effects of Smp24 and its mode of action on lung cancer cell lines remain unknown. Herein, the effect of Smp24 on the viability, membrane disruption, cytoskeleton, migration and invasion, and MMP-2/-9 and TIMP-1/-2 expression of human lung cancer cells have been evaluated. In addition, its in vivo antitumor role and acute toxicity were also assessed. In our study, Smp24 was found to suppress the growth of A549, H3122, PC-9, and H460 with IC₅₀ values from about 4.06 to 7.07 µM and show low toxicity to normal cells (MRC-5) with 14.68 µM of IC₅₀. Furthermore, Smp24 could induce necrosis of A549 cells via destroying the integrity of the cell membrane and mitochondrial and nuclear membranes. Additionally, Smp24 suppressed cell motility by damaging the cytoskeleton and altering MMP-2/-9 and TIMP-1/-2 expression. Finally, Smp24 showed effective anticancer protection in a A549 xenograft mice model and low acute toxicity. Overall, these findings indicate that Smp24 significantly exerts an antitumor effect due to its induction of membrane defects and cytoskeleton disruption. Accordingly, our findings will open an avenue for developing scorpion venom peptides into chemotherapeutic agents targeting lung cancer cells.

Cordycepin enhances anti-tumor immunity in colon cancer by inhibiting phagocytosis immune checkpoint CD47 expression

Cordycepin, also known as 3'-deoxyadenosine, is an extract from Cordyceps militaris, which has been reported as an anti-inflammation and anti-tumor substance without toxicity. However, the pharmacological mechanism of Cordycepin on tumor immunity under its anti-tumor effect has not yet been elucidated. Herein, we investigated Cordycepin's anti-tumor effect on colon cancer both in vitro and in vivo. Our results show that Cordycepin can inhibit growth, migration, and promoted apoptosis of CT26 cells in a dose-dependent manner. Cordycepin suppressed the growth of colon cancer in mouse subcutaneous tumor model by modulating tumor immune microenvironment where CD4⁺ T, CD8⁺ T, M1 type macrophages, NK cells were up-regulated. Further investigations revealed that Cordycepin inhibited phagocytosis immune checkpoint CD47 protein expression by reducing BNIP3 expression. In addition, Cordycepin also inhibited the expression of TSP1 in tumor cells and Jurkat cells, which may reduce the binding of TSP1 to CD47, thereby reducing T cell apoptosis and allowing more T cells to infiltrate into tumors. And in vitro co-culture experiments proved that Cordycepin could enhance the phagocytosis of CT26 cells by macrophages. These results explained the underlying mechanism of the anti-tumor immunity of Cordycepin. In conclusion, our results identify a novel mechanism by which Cordycepin inhibits phagocytosis immune checkpoint CD47 in tumor cells to promote tumor cells phagocytosis of macrophages. Cordycepin may be able to serve as a more effective immunotherapeutic drug against colon cancer.

Intracellular Self-Assembly of Peptides to Induce Apoptosis against Drug-Resistant Melanoma

Biosynthesis has been a diverse toolbox to develop bioactive molecules and materials, especially for fabricating modified peptides and their assemblies induced by enzymes. Although desired chemical structures and nanoarchitectures have been achieved, the subsequent interferences of peptide assemblies with organelles and the cellular pathways still remain unsolved important challenges. Herein, we developed a new tripeptide, phenylalanine-phenylalanine-tyrosine (Phe-Phe-Tyr, or FFY), which can be intracellularly oxidized and in situ self-assemble into nanoparticles with excellent interference capability with microtubules and ultimately reverse the drug resistance of melanoma. With the catalysis of tyrosinase, FFY was first oxidized to a melanin-like FFY dimer (mFFY) with a diquinone structure for further self-assembling into mFFY assemblies, which could inhibit the self-polymerization of tubulin to induce severe G2/M arrest (13.9% higher than control). Afterward, mitochondrial dysfunction was also induced for overproduction of cleaved caspase 3 (3.1 times higher than control) and cleaved PARP (6.3 times higher), achieving a high level of resistant reversing without chemotherapeutic drugs. In vivo studies showed that the resistant melanoma tumor volumes were reduced by 87.4% compared to control groups after FFY treatment by peritumoral injections. Overall, this tyrosinase-induced tripeptide assembly has been demonstrated with effective intrinsic apoptosis against drug-resistant melanoma, providing a new insight into utilizing biomolecules to interfere with organelles to activate certain apoptosis pathways for treatment of drug-resistant cancer.

GATA binding protein 5 (GATA5) induces Rho GTPase activating protein 9 (ARHGAP9) to inhibit the malignant process of lung adenocarcinoma cells

Lung adenocarcinoma is the main cause of the excessive mortality for patients who lives with lung cancers. According to the GEPIA database analysis, GATA5 and ARHGAP9 were found to be low expressed in lung adenocarcinoma, and they were positively correlated, and in addition ARHGAP9 low expression was associated with poor prognosis in lung adenocarcinoma. Therefore, the present study focused on the effect of promoting GATA5 to induce ARHGAP9 on the malignant process of lung adenocarcinoma cells. The expressions of GATA5 and ARHGAP9 were measured with Western blot and RT-qPCR. With the adoption of CCK-8, EDU staining, transwell and colony formation, the cell viability, proliferation, invasion and tumorigenesis ability were detected, respectively. In addition, the wound healing and Western blot were employed to evaluate migration and metastasis-related proteins individually. Moreover, the luciferase activity as well as the binding of GATA5 and ARHGAP9 promoters were detected by luciferase report and ChIP. After further comprehensive assessments, the results confirmed that GATA5 could successfully activate ARHGAP9. Moreover, ARHGAP9 upregulation remarkably inhibited lung adenocarcinoma cell proliferation, invasion and migration as compared to the control group. More importantly, GATA5 silencing reversed the inhibitory effect of ARHGAP9 upregulation on the malignant progression of lung adenocarcinoma cells. To conclude, the present study successfully demonstrated for the first time that GATA5-induced ARHGAP9 upregulation has a protective effect on lung adenocarcinoma cells.

A Balance Between Autophagy and Other Cell Death Modalities in Cancer

Autophagy is an intracellular self-digestive process involved in catabolic degradation of damaged proteins, and organelles, and the elimination of cellular pathogens. Initially, autophagy was considered as a prosurvival mechanism, but the following insights shed light on its prodeath function. Nowadays, autophagy is established as a crucial player in the development of various diseases through interaction with other molecular pathways within a cell. Additionally, disturbance in autophagy is one of the main pathological alterations that lead to resistance of cancer cells to treatment. These autophagy-related pathologies gave rise to the development of new therapeutic drugs. Here, we summarize the current knowledge on the autophagic role in disease pathogenesis, particularly in cancer, and the interplay between autophagy and other cell death modalities in order to combat cancer.

Mitophagy in carcinogenesis and cancer treatment

In order to maintain a functional mitochondrial network, cells have developed a quality control mechanism, namely mitophagy. This process can be induced through different pathways. The most studied is the so-called PINK1/Parkin pathway, which is associated with ubiquitylation of several mitochondrial proteins that were initially found to be related to Parkinson's disease. Another type of mitophagy is known as receptor-mediated mitophagy, which includes proteins, such as BNIP3 and BNIP3L, also known as Nix. Through these two mechanisms, mitophagy fulfills its functions and maintains cellular homeostasis. Here, we summarize the current knowledge about the mechanisms of mitophagy regulation and their interplay with cancer progression as well as anticancer treatment.

Microtubule-Based Mitochondrial Dynamics as a Valuable Therapeutic Target in Cancer

Mitochondria constitute an ever-reorganizing dynamic network that plays a key role in several fundamental cellular functions, including the regulation of metabolism, energy production, calcium homeostasis, production of reactive oxygen species, and programmed cell death. Each of these activities can be found to be impaired in cancer cells. It has been reported that mitochondrial dynamics are actively involved in both tumorigenesis and metabolic plasticity, allowing cancer cells to adapt to unfavorable environmental conditions and, thus, contributing to tumor progression. The mitochondrial dynamics include fusion, fragmentation, intracellular trafficking responsible for redistributing the organelle within the cell, biogenesis, and mitophagy. Although the mitochondrial dynamics are driven by the cytoskeleton-particularly by the microtubules and the microtubule-associated motor proteins dynein and kinesin-the molecular mechanisms regulating these complex processes are not yet fully understood. More recently, an exchange of mitochondria between stromal and cancer cells has also been described. The advantage of mitochondrial transfer in tumor cells results in benefits to cell survival, proliferation, and spreading. Therefore, understanding the molecular mechanisms that regulate mitochondrial trafficking can potentially be important for identifying new molecular targets in cancer therapy to interfere specifically with tumor dissemination processes.

BNIP3 in melanoma: isn't it IRONic?

Melanoma cells exploit mitophagy and hypoxia signaling to promote their growth. In a recent study, we found that loss of B-cell lymphoma 2 (BCL-2)/adenovirus E1B 19kDa protein-interacting protein 3 (BNIP3) curbed Hypoxia Inducible Factor 1 alpha (HIF-1α) levels and melanoma growth in vivo. Insufficient levels of BNIP3 boost iron-driven prolyl hydroxylase 2 (Phd2)-mediated degradation of HIF-1α by exacerbating nuclear receptor activator 4 (Ncoa4)-mediated ferritinophagy. Thus, BNIP3 promotes melanoma growth by controlling iron metabolism.

The Nucleus/Mitochondria-Shuttling LncRNAs Function as New Epigenetic Regulators of Mitophagy in Cancer

Mitophagy is a specialized autophagic pathway responsible for the selective removal of damaged or dysfunctional mitochondria by targeting them to the autophagosome in order to maintain mitochondria quality. The role of mitophagy in tumorigenesis has been conflicting, with the process both supporting tumor cell survival and promoting cell death. Cancer cells may utilize the mitophagy pathway to augment their metabolic requirements and resistance to cell death, thereby leading to increased cell proliferation and invasiveness. This review highlights major regulatory pathways of mitophagy involved in cancer. In particular, we summarize recent progress regarding how nuclear-encoded long non-coding RNAs (lncRNAs) function as novel epigenetic players in the mitochondria of cancer cells, affecting the malignant behavior of tumors by regulating mitophagy. Finally, we discuss the potential application of regulating mitophagy as a new target for cancer therapy.

RhoGTPase Signalling in Cancer Progression and Dissemination

Rho GTPases are a family of small G proteins that regulate a wide array of cellular processes related to their key roles controlling the cytoskeleton. On the other hand, cancer is a multi-step disease caused by the accumulation of genetic mutations and epigenetic alterations, from the initial stages of cancer development when cells in normal tissues undergo transformation, to the acquisition of invasive and metastatic traits, responsible for a large number of cancer related deaths. In this review, we discuss the role of Rho GTPase signalling in cancer in every step of disease progression. Rho GTPases contribute to tumour initiation and progression, by regulating proliferation and apoptosis, but also metabolism, senescence and cell stemness. Rho GTPases play a major role in cell migration, and in the metastatic process. They are also involved in interactions with the tumour microenvironment and regulate inflammation, contributing to cancer progression. After years of intensive research, we highlight the importance of relevant models in the Rho GTPase field, and we reflect on the therapeutic opportunities arising for cancer patients.

TRPS1 knockdown inhibits angiogenic vascular mimicry in human triple negative breast cancer cells

PURPOSE

Vascular mimicry (VM) tubules are lumen structures comprised of malignant tumor cells without the participation of endothelial cells. VM simulates blood vessel function in tumors to deliver a sufficient blood supply for proliferation, invasion, and metastasis of malignant tumors, thereby reducing the clinical effects of anti-angiogenic treatments. The elimination or prevention of malignant tumor VM development therefore represents an urgent research goal as a therapeutic strategy to and cut off nutrients required for tumor growth. The GATA transcription factor TRPS1 is abnormally up-regulated in breast cancer, osteosarcoma, prostate cancer, and other tumor tissues, and is instrumental in regulating cell proliferation, differentiation, and tissue growth and development.

METHODS

Here, we explored the effects of TRPS1 knockdown on VM and the proteins underlying its development in triple-negative breast cancer cell line MDA-MB-231.

RESULTS

We found that TRPS1 knockdown resulted in obvious inhibition of VM development. Fluorescence microscopy of F-actin and tubulin revealed that loss of TRPS1 function resulted in disruption of cytoskeleton and microtubule formation, respectively. In addition, TRPS1-suppressed cells exhibited reduced accumulation of VM-associated proteins EphA2, MMP-2, MMP-9, VEGF, and VE-cadherin. Moreover, it is interesting to know that the capacity for migration and invasion were limited in MDA-MB-231cells after TRPS1 knockdown and that the average number of VM tubules, their length, and number of intersections were also significantly decreased.

CONCLUSIONS

Based on our results, and in light of previous studies, we thus proposed that TRPS1 suppression negatively affects vascular mimicry possibly through reduced TRPS1-mediated transcriptional regulation of VM-related protein VEGF-A.

BNIP3 promotes HIF-1α-driven melanoma growth by curbing intracellular iron homeostasis

BNIP3 is a mitophagy receptor with context-dependent roles in cancer, but whether and how it modulates melanoma growth in vivo remains unknown. Here, we found that elevated BNIP3 levels correlated with poorer melanoma patient's survival and depletion of BNIP3 in B16-F10 melanoma cells compromised tumor growth in vivo. BNIP3 depletion halted mitophagy and enforced a PHD2-mediated downregulation of HIF-1α and its glycolytic program both in vitro and in vivo. Mechanistically, we found that BNIP3-deprived melanoma cells displayed increased intracellular iron levels caused by heightened NCOA4-mediated ferritinophagy, which fostered PHD2-mediated HIF-1α destabilization. These effects were not phenocopied by ATG5 or NIX silencing. Restoring HIF-1α levels in BNIP3-depleted melanoma cells rescued their metabolic phenotype and tumor growth in vivo, but did not affect NCOA4 turnover, underscoring that these BNIP3 effects are not secondary to HIF-1α. These results unravel an unexpected role of BNIP3 as upstream regulator of the pro-tumorigenic HIF-1α glycolytic program in melanoma cells.

Mitophagy in tumorigenesis and metastasis

Cells use mitophagy to remove dysfunctional or excess mitochondria, frequently in response to imposed stresses, such as hypoxia and nutrient deprivation. Mitochondrial cargo receptors (MCR) induced by these stresses target mitochondria to autophagosomes through interaction with members of the LC3/GABARAP family. There are a growing number of these MCRs, including BNIP3, BNIP3L, FUNDC1, Bcl2-L-13, FKBP8, Prohibitin-2, and others, in addition to mitochondrial protein targets of PINK1/Parkin phospho-ubiquitination. There is also an emerging link between mitochondrial lipid signaling and mitophagy where ceramide, sphingosine-1-phosphate, and cardiolipin have all been shown to promote mitophagy. Here, we review the upstream signaling mechanisms that regulate mitophagy, including components of the mitochondrial fission machinery, AMPK, ATF4, FoxOs, Sirtuins, and mtDNA release, and address the significance of these pathways for stress responses in tumorigenesis and metastasis. In particular, we focus on how mitophagy modulators intersect with cell cycle control and survival pathways in cancer, including following ECM detachment and during cell migration and metastasis. Finally, we interrogate how mitophagy affects tissue atrophy during cancer cachexia and therapy responses in the clinic.

Molecular mechanisms and physiological functions of mitophagy

Degradation of mitochondria via a selective form of autophagy, named mitophagy, is a fundamental mechanism conserved from yeast to humans that regulates mitochondrial quality and quantity control. Mitophagy is promoted via specific mitochondrial outer membrane receptors, or ubiquitin molecules conjugated to proteins on the mitochondrial surface leading to the formation of autophagosomes surrounding mitochondria. Mitophagy-mediated elimination of mitochondria plays an important role in many processes including early embryonic development, cell differentiation, inflammation, and apoptosis. Recent advances in analyzing mitophagy in vivo also reveal high rates of steady-state mitochondrial turnover in diverse cell types, highlighting the intracellular housekeeping role of mitophagy. Defects in mitophagy are associated with various pathological conditions such as neurodegeneration, heart failure, cancer, and aging, further underscoring the biological relevance. Here, we review our current molecular understanding of mitophagy, and its physiological implications, and discuss how multiple mitophagy pathways coordinately modulate mitochondrial fitness and populations.

Macrophage-Mediated Tumor Cell Phagocytosis: Opportunity for Nanomedicine Intervention

Macrophages are one of the most abundant non-malignant cells in the tumor microenvironment, playing critical roles in mediating tumor immunity. As important innate immune cells, macrophages possess the potential to engulf tumor cells and present tumor-specific antigens for adaptive antitumor immunity induction, leading to growing interest in targeting macrophage phagocytosis for cancer immunotherapy. Nevertheless, live tumor cells have evolved to evade phagocytosis by macrophages via the extensive expression of anti-phagocytic molecules, such as CD47. In addition, macrophages also rapidly recognize and engulf apoptotic cells (efferocytosis) in the tumor microenvironment, which inhibits inflammatory responses and facilitates immune escape of tumor cells. Thus, intervention of macrophage phagocytosis by blocking anti-phagocytic signals on live tumor cells or inhibiting tumor efferocytosis presents a promising strategy for the development of cancer immunotherapies. Here, the regulation of macrophage-mediated tumor cell phagocytosis is first summarized, followed by an overview of strategies targeting macrophage phagocytosis for the development of antitumor therapies. Given the potential off-target effects associated with the administration of traditional therapeutics (for example, monoclonal antibodies, small molecule inhibitors), we highlight the opportunity for nanomedicine in macrophage phagocytosis intervention.

Sirtuins' control of autophagy and mitophagy in cancer

Mammalian cells use a specialized and complex machinery for the removal of altered proteins or dysfunctional organelles. Such machinery is part of a mechanism called autophagy. Moreover, when autophagy is specifically employed for the removal of dysfunctional mitochondria, it is called mitophagy. Autophagy and mitophagy have important physiological implications and roles associated with cellular differentiation, resistance to stresses such as starvation, metabolic control and adaptation to the changing microenvironment. Unfortunately, transformed cancer cells often exploit autophagy and mitophagy for sustaining their metabolic reprogramming and growth to a point that autophagy and mitophagy are recognized as promising targets for ongoing and future antitumoral therapies. Sirtuins are NAD+ dependent deacylases with a fundamental role in sensing and modulating cellular response to external stresses such as nutrients availability and therefore involved in aging, oxidative stress control, inflammation, differentiation and cancer. It is clear, therefore, that autophagy, mitophagy and sirtuins share many common aspects to a point that, recently, sirtuins have been linked to the control of autophagy and mitophagy. In the context of cancer, such a control is obtained by modulating transcription of autophagy and mitophagy genes, by post translational modification of proteins belonging to the autophagy and mitophagy machinery, by controlling ROS production or major metabolic pathways such as Krebs cycle or glutamine metabolism. The present review details current knowledge on the role of sirtuins, autophagy and mitophagy in cancer to then proceed to discuss how sirtuins can control autophagy and mitophagy in cancer cells. Finally, we discuss sirtuins role in the context of tumor progression and metastasis indicating glutamine metabolism as an example of how a concerted activation and/or inhibition of sirtuins in cancer cells can control autophagy and mitophagy by impinging on the metabolism of this fundamental amino acid.

BNIP3 in Lung Cancer: To Kill or Rescue?

Simple Summary

Bcl-2/adenovirus E1B 19kDa interacting protein 3 (BNIP3) is a pro-apoptotic BH3-only protein of the Bcl-2 family. Its function in various biological processes was described. Although potential involvement of BNIP3 in cancer progression has been discussed in many review articles, its specific role in lung cancer is still unclear. In this review, we shed light on the BNIP3‘s role in different types of cancer in general and lung cancer, in particular, as well as suggested its potential for targeting therapy of lung cancer.

Abstract

Bcl-2/adenovirus E1B 19kDa interacting protein 3 (BNIP3) is a pro-apoptotic BH3-only protein of the Bcl-2 family. Initially, BNIP3 was described as one of the mediators of hypoxia-induced apoptotic cell death in cardiac myocytes and neurons. Besides apoptosis, BNIP3 plays a crucial role in autophagy, metabolic pathways, and metastasis-related processes in different tumor types. Lung cancer is one of the most aggressive types of cancer, which is often diagnosed at an advanced stage. Therefore, there is still urgent demand for reliable biochemical markers for lung cancer and its efficient treatment. Mitochondria functioning and mitochondrial proteins, including BNIP3, have a strong impact on lung cancer development and progression. Here, we summarized current knowledge about the BNIP3 gene and protein features and their role in cancer progression, especially in lung cancer in order to develop new therapeutic approaches associated with BNIP3.

The Non-Coding Landscape of Cutaneous Malignant Melanoma: A Possible Route to Efficient Targeted Therapy

Considered to be highly lethal if not diagnosed in early stages, cutaneous malignant melanoma is among the most aggressive and treatment-resistant human cancers, and its incidence continues to rise, largely due to ultraviolet radiation exposure, which is the main carcinogenic factor. Over the years, researchers have started to unveil the molecular mechanisms by which malignant melanoma can be triggered and sustained, in order to establish specific, reliable biomarkers that could aid the prognosis and diagnosis of this fatal disease, and serve as targets for development of novel efficient therapies. The high mutational burden and heterogeneous nature of melanoma shifted the main focus from the genetic landscape to epigenetic and epitranscriptomic modifications, aiming at elucidating the role of non-coding RNA molecules in the fine tuning of melanoma progression. Here we review the contribution of microRNAs and lncRNAs to melanoma invasion, metastasis and acquired drug resistance, highlighting their potential for clinical applications as biomarkers and therapeutic targets.

Multifaceted effects of soluble human CD6 in experimental cancer models

Background

CD6 is a lymphocyte surface co-receptor physically associated with the T-cell receptor (TCR)/CD3 complex at the center of the immunological synapse. There, CD6 assists in cell-to-cell contact stabilization and modulation of activation/differentiation events through interaction with CD166/ALCAM (activated leukocyte cell adhesion molecule), its main reported ligand. While accumulating evidence is attracting new interest on targeting CD6 for therapeutic purposes in autoimmune disorders, little is known on its potential in cancer. In an attempt to elucidate the in vivo relevance of blocking CD6-mediated interactions in health and disease, we explored the consequences of expressing high circulating levels of a soluble form CD6 (sCD6) as a decoy receptor.

Methods

High sCD6 serum levels were achieved by using transgenic C57BL/6 mice expressing human sCD6 under the control of lymphoid-specific transcriptional elements (shCD6LckEμTg) or wild type either transduced with hepatotropic adeno-associated virus coding for mouse sCD6 or undergoing repeated infusions of recombinant human sCD6 protein. Characterization of sCD6-induced changes was performed by ex vivo flow cytometry and functional analyses of mouse lymphoid organ cells. The in vivo relevance of those changes was explored by challenging mice with subcutaneous or metastatic tumors induced by syngeneic cancer cells of different lineage origins.

Results

Through a combination of in vitro and in vivo studies, we show that circulating sCD6 expression induces defective regulatory T cell (Treg) generation and function, decreased CD166/ALCAM-mediated tumor cell proliferation/migration and impaired galectin-induced T-cell apoptosis, supporting the fact that sCD6 modulates antitumor lymphocyte effector function and tumorigenesis. Accordingly, sCD6 expression in vivo resulted in delayed subcutaneous tumor growth and/or reduced metastasis on challenge of mice with syngeneic cancer cells.

Conclusions

Evidence is provided for the disruption of CD6 receptor–ligand interactions as a feasible immunomodulatory approach in cancer.

Cardiolipin, the Mitochondrial Signature Lipid: Implication in Cancer

Cardiolipins (CLs) are specific phospholipids of the mitochondria composing about 20% of the inner mitochondria membrane (IMM) phospholipid mass. Dysregulation of CL metabolism has been observed in several types of cancer. In most cases, the evidence for a role for CL in cancer is merely correlative, suggestive, ambiguous, and cancer-type dependent. In addition, CLs could play a pivotal role in several mitochondrial functions/parameters such as bioenergetics, dynamics, mitophagy, and apoptosis, which are involved in key steps of cancer aggressiveness (i.e., migration/invasion and resistance to treatment). Therefore, this review focuses on studies suggesting that changes in CL content and/or composition, as well as CL metabolism enzyme levels, may be linked with the progression and the aggressiveness of some types of cancer. Finally, we also introduce the main mitochondrial function in which CL could play a pivotal role with a special focus on its implication in cancer development and therapy.

Involvement of Actin and Actin-Binding Proteins in Carcinogenesis

The actin cytoskeleton plays a crucial role in many cellular processes while its reorganization is important in maintaining cell homeostasis. However, in the case of cancer cells, actin and ABPs (actin-binding proteins) are involved in all stages of carcinogenesis. Literature has reported that ABPs such as SATB1 (special AT-rich binding protein 1), WASP (Wiskott-Aldrich syndrome protein), nesprin, and villin take part in the initial step of carcinogenesis by regulating oncogene expression. Additionally, changes in actin localization promote cell proliferation by inhibiting apoptosis (SATB1). In turn, migration and invasion of cancer cells are based on the formation of actin-rich protrusions (Arp2/3 complex, filamin A, fascin, α-actinin, and cofilin). Importantly, more and more scientists suggest that microfilaments together with the associated proteins mediate tumor vascularization. Hence, the presented article aims to summarize literature reports in the context of the potential role of actin and ABPs in all steps of carcinogenesis.

Sulforaphane-cysteine inhibited migration and invasion via enhancing mitophagosome fusion to lysosome in human glioblastoma cells

Here we uncovered the involved subcellular mechanisms that sulforaphane-cysteine (SFN-Cys) inhibited invasion in human glioblastoma (GBM). SFN-Cys significantly upregulated 45 and downregulated 14 microtubule-, mitophagy-, and invasion-associated proteins in GBM cells via HPLC-MS/MS and GEO ontology analysis; SFN-Cys disrupted microtubule by ERK1/2 phosphorylation-mediated downregulation of α-tubulin and Stathmin-1 leading to the inhibition of cell migration and invasion; SFN-Cys downregulated invasion-associated Claudin-5 and S100A4, and decreased the interaction of α-tubulin to Claudin-5. Knockdown of Claudin-5 and S100A4 significantly reduced the migration and invasion. Besides, SFN-Cys lowered the expressions of α-tubulin-mediated mitophagy-associated proteins Bnip3 and Nix. Transmission electron microscopy showed more membrane-deficient mitochondria and accumulated mitophagosomes in GBM cells, and mitochondria fusion might be downregulated because that SFN-Cys downregulated mitochondrial fusion protein OPA1. SFN-Cys increased the colocalization and interplay of LC3 to lysosomal membrane-associated protein LAMP1, aggravating the fusion of mitophagosome to lysosome. Nevertheless, SFN-Cys inhibited the lysosomal proteolytic capacity causing LC3II/LC3I elevation but autophagy substrate SQSTM1/p62 was not changed, mitophagosome accumulation, and the inhibition of migration and invasion in GBM cells. These results will help us develop high-efficiency and low-toxicity anticancer drugs to inhibit migration and invasion in GBM.

Wnt5a regulates Ameloblastoma Cell Migration by modulating Mitochondrial and Cytoskeletal Dynamics

Objective: Abnormal expression of Wnt5a has been detected in various tumors, including ameloblastoma (AB). Yet, there is no specific mechanistic evidence for the functional role of Wnt5a in AB. In this study, we aimed to conduct a mechanistic examination of the importance of Wnt5a in AB development. Methods: The expressions of Wnt5a and Coro1A were examined by Western blot and immunohistochemistry both in AB tissues and AM-1 cells. The number and size of mitochondria were detected by electronic transmission microscope and confocal microscope. Gain-of-function and loss-of-function assays were used to explore the biological roles of Wnt5a and Coro1A in organelle dynamics changes and cell migration. Cell migration was detected by wound healing and transwell assay. Results: We found that in AM-1 cells, up-regulation of Wnt5a led to enhanced mitochondrial energy production and altered calcium homeostasis, with elevated calcium levels directly leading to altered mitochondrial dynamics and interactions between the cytoskeleton and the mitochondria. When Wnt5a or its downstream cytoskeleton-associated protein Coro1A was knocked down, the migration capacity of AM-1 cells was markedly impaired. Conclusion: Together, these results suggest that Wnt5a plays mitochondria and cytoskeleton specific roles in regulating the development of human AB, with its down-regulation leading to impaired tumor development, thus highlighting Wnt5a or Coro1A as potentially viable therapeutic targets for the treatment of AB.

Gene Expression Signature of BRAF Inhibitor Resistant Melanoma Spheroids

In vitro cell cultures are frequently used to define the molecular background of drug resistance. The majority of currently available data have been obtained from 2D in vitro cultures, however, 3D cell culture systems (spheroids) are more likely to behave similarly to in vivo conditions. Our major aim was to compare the gene expression signature of 2D and 3D cultured BRAFV600E mutant melanoma cell lines. We successfully developed BRAF-drug resistant cell lines from paired primary/metastatic melanoma cell lines in both 2D and 3D in vitro cultures. Using Affymetrix Human Gene 1.0 ST arrays, we determined the gene expression pattern of all cell lines. Our analysis revealed 1049 genes (562 upregulated and 487 downregulated) that were differentially expressed between drug-sensitive cells grown under different cell cultures. Pathway analysis showed that the differently expressed genes were mainly associated with the cell cycle, p53, and other cancer-related pathways. The number of upregulated genes (72 genes) was remarkably fewer when comparing the resistant adherent cells to cells that grow in 3D, and were associated with cell adhesion molecules and IGF1R signalling. Only 1% of the upregulated and 5.6% of the downregulated genes were commonly altered between the sensitive and the resistant spheroids. Interestingly, we found several genes (BNIP3, RING1 and ABHD4) with inverse expression signature between sensitive and resistant spheroids, which are involved in anoikis resistance and cell cycle regulation. In summary, our study highlights gene expression alterations that might help to understand the development of acquired resistance in melanoma cells in tumour tissue.

The Role of Mitochondrial Dynamics and Mitophagy in Carcinogenesis, Metastasis and Therapy

Mitochondria are key cellular organelles and play vital roles in energy metabolism, apoptosis regulation and cellular homeostasis. Mitochondrial dynamics refers to the varying balance between mitochondrial fission and mitochondrial fusion that plays an important part in maintaining mitochondrial homeostasis and quality. Mitochondrial malfunction is involved in aging, metabolic disease, neurodegenerative disorders, and cancers. Mitophagy, a selective autophagy of mitochondria, can efficiently degrade, remove and recycle the malfunctioning or damaged mitochondria, and is crucial for quality control. In past decades, numerous studies have identified a series of factors that regulate mitophagy and are also involved in carcinogenesis, cancer cell migration and death. Therefore, it has become critically important to analyze signal pathways that regulate mitophagy to identify potential therapeutic targets. Here, we review recent progresses in mitochondrial dynamics, the mechanisms of mitophagy regulation, and the implications for understanding carcinogenesis, metastasis, treatment, and drug resistance.

Small Ones to Fight a Big Problem-Intervention of Cancer Metastasis by Small Molecules

Metastasis represents the most lethal attribute of cancer and critically limits successful therapies in many tumor entities. The clinical need is defined by the fact that all cancer patients, who have or who will develop distant metastasis, will experience shorter survival. Thus, the ultimate goal in cancer therapy is the restriction of solid cancer metastasis by novel molecularly targeted small molecule based therapies. Biomarkers identifying cancer patients at high risk for metastasis and simultaneously acting as key drivers for metastasis are extremely desired. Clinical interventions targeting these key molecules will result in high efficiency in metastasis intervention. In result of this, personalized tailored interventions for restriction and prevention of cancer progression and metastasis will improve patient survival. This review defines crucial biological steps of the metastatic cascade, such as cell dissemination, migration and invasion as well as the action of metastasis suppressors. Targeting these biological steps with tailored therapeutic strategies of intervention or even prevention of metastasis using a wide range of small molecules will be discussed.

Vascular mimicry: changing the therapeutic paradigms in cancer

Cancer is a major problem in the health system, and despite many efforts to effectively treat it, none has yet been fully successful. Angiogenesis and metastasis are considered as major challenges in the treatment of various cancers. Researchers have struggled to succeed with anti-angiogenesis drugs for the effective treatment of cancer, although new challenges have emerged in the treatment with the emergence of resistance to anti-angiogenesis and anti-metastatic drugs. Numerous studies have shown that different cancers can resist anti-angiogenesis drugs in a new process called vascular mimicry (VM). The studies have revealed that cells resistant to anti-angiogenesis cancer therapies are more capable of forming VMs in the in vivo and in vitro environment, although there is a link between the presence of VM and poor clinical outcomes. Given the importance of the VM in the challenges facing cancer treatment, researchers are trying to identify factors that prevent the formation of these structures. In this review article, it is attempted to provide a comprehensive overview of the molecules and main signaling pathways involved in VM phenomena, as well as the agents currently being identified as anti-VM and the role of VM in response to treatment and prognosis of cancer patients.

Targeting Rac and Cdc42 GEFs in Metastatic Cancer

The Rho family GTPases Rho, Rac, and Cdc42 have emerged as key players in cancer metastasis, due to their essential roles in regulating cell division and actin cytoskeletal rearrangements; and thus, cell growth, migration/invasion, polarity, and adhesion. This review will focus on the close homologs Rac and Cdc42, which have been established as drivers of metastasis and therapy resistance in multiple cancer types. Rac and Cdc42 are often dysregulated in cancer due to hyperactivation by guanine nucleotide exchange factors (GEFs), belonging to both the diffuse B-cell lymphoma (Dbl) and dedicator of cytokinesis (DOCK) families. Rac/Cdc42 GEFs are activated by a myriad of oncogenic cell surface receptors, such as growth factor receptors, G-protein coupled receptors, cytokine receptors, and integrins; consequently, a number of Rac/Cdc42 GEFs have been implicated in metastatic cancer. Hence, inhibiting GEF-mediated Rac/Cdc42 activation represents a promising strategy for targeted metastatic cancer therapy. Herein, we focus on the role of oncogenic Rac/Cdc42 GEFs and discuss the recent advancements in the development of Rac and Cdc42 GEF-interacting inhibitors as targeted therapy for metastatic cancer, as well as their potential for overcoming cancer therapy resistance.

Preconditioning of Human Decidua Basalis Mesenchymal Stem/Stromal Cells with Glucose Increased Their Engraftment and Anti-diabetic Properties

Background:

Mesenchymal stem/stromal cells (MSCs) from the decidua basalis (DBMSCs) of the human placenta have important functions that make them potential candidates for cellular therapy. Previously, we showed that DBMSC functions do not change significantly in a high oxidative stress environment, which was induced by hydrogen peroxide (H₂O₂) and immune cells. Here, we studied the consequences of glucose, another oxidative stress inducer, on the phenotypic and functional changes in DBMSCs.

Methods:

DBMSCs were exposed to a high level of glucose, and its effect on DBMSC phenotypic and functional properties was determined. DBMSC expression of oxidative stress and immune molecules after exposure to glucose were also identified.

Results:

Conditioning of DBMSCs with glucose improved their adhesion and invasion. Glucose also increased DBMSC expression of genes with survival, proliferation, migration, invasion, anti-inflammatory, anti-chemoattractant and antimicrobial properties. In addition, DBMSC expression of B7H4, an inhibitor of T cell proliferation was also enhanced by glucose. Interestingly, glucose modulated DBMSC expression of genes involved in insulin secretion and prevention of diabetes.

Conclusion:

These data show the potentially beneficial effects of glucose on DBMSC functions. Preconditioning of DBMSCs with glucose may therefore be a rational strategy for increasing their therapeutic potential by enhancing their engraftment efficiency. In addition, glucose may program DBMSCs into insulin producing cells with ability to counteract inflammation and infection associated with diabetes. However, future in vitro and in vivo studies are essential to investigate the findings of this study further.

Electronic supplementary material

The online version of this article (10.1007/s13770-020-00239-7) contains supplementary material, which is available to authorized users.

Mitochondrial Dysfunction at the Center of Cancer Therapy

Significance: Mitochondria undergo constant morphological changes through fusion, fission, and mitophagy. As the key organelle in cells, mitochondria are responsible for numerous essential cellular functions such as metabolism, regulation of calcium (Ca²⁺), generation of reactive oxygen species, and initiation of apoptosis. Unsurprisingly, mitochondrial dysfunctions underlie many pathologies including cancer. Recent Advances: Currently, the gold standard for cancer treatment is chemotherapy, radiation, and surgery. However, the efficacy of these treatments varies across different cancer cells. It has been suggested that mitochondria may be at the center of these diverse responses. In the past decade, significant advances have been made in understanding distinct types of mitochondrial dysfunctions in cancer. Through investigations of underlying mechanisms, more effective treatment options are developed. Critical Issues: We summarize various mitochondria dysfunctions in cancer progression that have led to the development of therapeutic options. Current mitochondrial-targeted therapies and challenges are discussed. Future Directions: To address the "root" of cancer, utilization of mitochondrial-targeted therapy to target cancer stem cells may be valuable. Investigation of other areas such as mitochondrial trafficking may offer new insights into cancer therapy. Moreover, common antibiotics could be explored as mitocans, and synthetic lethality screens can be utilized to overcome the plasticity of cancer cells.

The Complex Role of Autophagy in Melanoma Evolution: New Perspectives From Mouse Models

Despite tremendous efforts in the last decade to improve treatments, melanoma still represents a major therapeutic challenge and overall survival of patients remains poor. Therefore, identifying new targets to counteract melanoma is needed. In this scenario, autophagy, the “self-eating” process of the cell, has recently arisen as new potential candidate in melanoma. Alongside its role as a recycling mechanism for dysfunctional and damaged cell components, autophagy also clearly sits at a crossroad with metabolism, thereby orchestrating cell proliferation, bioenergetics and metabolic rewiring, all hallmarks of cancer cells. In this regard, autophagy, both in tumor and host, has been flagged as an essential player in melanomagenesis and progression. To pave the way to a better understanding of such a complex interplay, the use of genetically engineered mouse models (GEMMs), as well as syngeneic mouse models, has been undoubtedly crucial. Herein, we will explore the latest discoveries in the field, with particular focus on the potential of these models in unraveling the contribution of autophagy in melanoma, along with the therapeutic advantages that may arise.

Mitochondrial Involvement in Migration, Invasion and Metastasis

Mitochondria in addition to be a main cellular power station, are involved in the regulation of many physiological processes, such as generation of reactive oxygen species, metabolite production and the maintenance of the intracellular Ca²⁺ homeostasis. Almost 100 years ago Otto Warburg presented evidence for the role of mitochondria in the development of cancer. During the past 20 years mitochondrial involvement in programmed cell death regulation has been clarified. Moreover, it has been shown that mitochondria may act as a switchboard between various cell death modalities. Recently, accumulated data have pointed to the role of mitochondria in the metastatic dissemination of cancer cells. Here we summarize the modern knowledge concerning the contribution of mitochondria to the invasion and dissemination of tumor cells and the possible mechanisms behind that and attempts to target metastatic cancers involving mitochondria.

BNIP3 contributes to the glutamine-driven aggressive behavior of melanoma cells

Aerobic glycolysis ('Warburg effect') is used by cancer cells to fuel tumor growth. Interestingly, metastatic melanoma cells rely on glutaminolysis rather than aerobic glycolysis for their bioenergetic needs through the tricarboxylic acid (TCA) cycle. Here, we compared the effects of glucose or glutamine on melanoma cell proliferation, migration and oxidative phosphorylation in vitro. We found that glutamine-driven melanoma cell's aggressive traits positively correlated with increased expression of HIF1α and its pro-autophagic target BNIP3. BNIP3 silencing reduced glutamine-mediated effects on melanoma cell growth, migration and bioenergetics. Hence, BNIP3 is a vital component of the mitochondria quality control required for glutamine-driven melanoma aggressiveness.

Bnip3 regulates airway smooth muscle cell focal adhesion and proliferation

Increased airway smooth muscle (ASM) mass is a key contributor to airway narrowing and airway hyperresponsiveness in asthma. Besides conventional pathways and regulators of ASM proliferation, recent studies suggest that changes in mitochondrial morphology and function play a role in airway remodeling in asthma. In this study, we aimed at determining the role of mitochondrial Bcl-2 adenovirus E1B 19 kDa-interacting protein, Bnip3, in the regulation of ASM proliferation. Bnip3 is a member of the Bcl-2 family of proteins critical for mitochondrial health, mitophagy, and cell survival/death. We found that Bnip3 expression is upregulated in ASM cells from asthmatic donors compared with that in ASM cells from healthy donors and transient downregulation of Bnip3 expression in primary human ASM cells using an siRNA approach decreased cell adhesion, migration, and proliferation. Furthermore, Bnip3 downregulation altered the structure (electron density) and function (cellular ATP levels, membrane potential, and reacitve oxygen species generation) of mitochondria and decreased expression of cytoskeleton proteins vinculin, paxillin, and actinin. These findings suggest that Bnip3 via regulation of mitochondria functions and expression of adhesion proteins regulates ASM adhesion, migration, and proliferation. This study reveals a novel role for Bnip3 in ASM functions and establishes Bnip3 as a potential target in mitigating ASM remodeling in asthma.