Alterations of the interactome of Bcl-2 proteins in breast cancer at the transcriptional, mutational and structural level

Recent advances in canonical versus non-canonical Ca2+-signaling-related anti-apoptotic Bcl-2 functions and prospects for cancer treatment

Cell fate is tightly controlled by a continuous balance between cell survival and cell death inducing mechanisms. B-cell lymphoma 2 (Bcl-2)-family members, composed of effectors and regulators, not only control apoptosis at the level of the mitochondria but also by impacting the intracellular Ca2+ homeostasis and dynamics. On the one hand, anti-apoptotic protein Bcl-2, prevents mitochondrial outer membrane permeabilization (MOMP) by scaffolding and neutralizing proapoptotic Bcl-2-family members via its hydrophobic cleft (region composed of BH-domain 1-3). On the other hand, Bcl-2 suppress pro-apoptotic Ca2+ signals by binding and inhibiting IP3 receptors via its BH4 domain, which is structurally exiled from the hydrophobic cleft by a flexible loop region (FLR). As such, Bcl-2 prevents excessive Ca2+ transfer from ER to mitochondria. Whereas regulation of both pathways requires different functional regions of Bcl-2, both seem to be connected in cancers that overexpress Bcl-2 in a life-promoting dependent manner. Here we discuss the anti-apoptotic canonical and non-canonical role, via calcium signaling, of Bcl-2 in health and cancer and evolving from this the proposed anti-cancer therapies with their shortcomings. We also argue how some cancers, with the major focus on diffuse large B-cell lymphoma (DLBCL) are difficult to treat, although theoretically prime marked for Bcl-2-targeting therapeutics. Further work is needed to understand the non-canonical functions of Bcl-2 also at organelles beyond the mitochondria, the interaction partners outside the Bcl-2 family as well as their ability to target or exploit these functions as therapeutic strategies in diseases.

Study on the anti-mitochondrial apoptosis mechanism of Erigeron breviscapus injection based on UPLC-Q-TOF-MS metabolomics and molecular docking in rats with cerebral ischemia-reperfusion injury

ETHNOPHARMACOLOGICAL RELEVANCE

Erigeron breviscapus is a common medicine of eight ethnic minorities, including Miao, Naxi, and Yi. As early as the Ming Dynasty (AD 1368-1644), Lanmao's Materia Medica of Southern Yunnan (AD 1436) recorded that the medicine is used for the treatment of "Zuo tan you huan." In modern pharmacological research, Erigeron breviscapus injection is the most commonly used preparation in the treatment of ischemic stroke caused by acute cerebral infarction, but its mechanism of action in the treatment of ischemic stroke is not well understood.

AIM OF THE STUDY

In this study, a metabonomics study based on ultraperformance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) was used in investigating the effect of a traditional Chinese medicine preparation Erigeron breviscapus injection on the rat model of focal cerebral ischemia-reperfusion and the affinity of its main components with the targets of mitochondrial apoptotic pathways.

MATERIALS AND METHODS

This study used molecular docking technology to verify the effective binding ability of main effective components of Erigeron breviscapus injection to target proteins related to mitochondrial apoptosis pathway. This study developed a metabonomics method based on the ultra-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) to evaluate the efficacy and study the mechanism of traditional Chinese medicine preparation. With pattern recognition analysis (principal component analysis and partial least squares-discriminate analysis) of urinary metabolites, a clear separation of focal cerebral ischemia-reperfusion model group and healthy control group was achieved.

RESULTS

Erigeron breviscapus injection can significantly reduce the area of cerebral infarction, improve tissue morphological lesion in rats, and can increase the number of Nissl bodies. It may be a promoting factor by inhibiting hippocampal nerve cell apoptosis and Bax protein expression and by exerting effects against ischemia reperfusion after the induction of apoptosis. Thus, it plays a role in brain protection. Moreover, it can considerably promote the recovery of neurological deficiency signs in advance. Meanwhile, Erigeron breviscapus decreased malondialdehyde content and T-NOS activity. Its curative effect from strong to weak order: low dose > high dose > medium dose. The representative components of Erigeron breviscapus have good affinity with the active sites of mitochondrial apoptosis-related proteins. Metabolomics found that the potential biomarkers regulated by breviscapine are kynurequinolinic acid, succinylornithine, and leucine proline. It is speculated that it may participate in TRP-kynurequinolinic acid and succinylornithine-urea cycle-NO metabolic pathways.

CONCLUSIONS

This paper revealed the potential biomarkers and metabolic pathways regulated by Erigeron breviscapus. It was speculated that the mechanism is related to its inhibition of mitochondrion-mediated apoptosis. Erigeron breviscapus could restore the metabolic profiles of the model animals to normal animal levels. The mechanism may be related to the potential biomarkers of quinolinic acid, succinylornithine, and leucine proline and the metabolic pathways involved. However, the exact mechanism by which Erigeron breviscapus inhibits mitochondrion-mediated apoptosis remains to be further explored.

Prediction of cancer driver genes and mutations: the potential of integrative computational frameworks

The vast amount of available sequencing data allows the scientific community to explore different genetic alterations that may drive cancer or favor cancer progression. Software developers have proposed a myriad of predictive tools, allowing researchers and clinicians to compare and prioritize driver genes and mutations and their relative pathogenicity. However, there is little consensus on the computational approach or a golden standard for comparison. Hence, benchmarking the different tools depends highly on the input data, indicating that overfitting is still a massive problem. One of the solutions is to limit the scope and usage of specific tools. However, such limitations force researchers to walk on a tightrope between creating and using high-quality tools for a specific purpose and describing the complex alterations driving cancer. While the knowledge of cancer development increases daily, many bioinformatic pipelines rely on single nucleotide variants or alterations in a vacuum without accounting for cellular compartments, mutational burden or disease progression. Even within bioinformatics and computational cancer biology, the research fields work in silos, risking overlooking potential synergies or breakthroughs. Here, we provide an overview of databases and datasets for building or testing predictive cancer driver tools. Furthermore, we introduce predictive tools for driver genes, driver mutations, and the impact of these based on structural analysis. Additionally, we suggest and recommend directions in the field to avoid silo-research, moving towards integrative frameworks.

Identifying Lymph Node Metastasis-Related Factors in Breast Cancer Using Differential Modular and Mutational Structural Analysis

Complex diseases are generally caused by disorders of biological networks and/or mutations in multiple genes. Comparisons of network topologies between different disease states can highlight key factors in their dynamic processes. Here, we propose a differential modular analysis approach that integrates protein-protein interactions with gene expression profiles for modular analysis, and introduces inter-modular edges and date hubs to identify the "core network module" that quantifies the significant phenotypic variation. Then, based on this core network module, key factors, including functional protein-protein interactions, pathways, and driver mutations, are predicted by the topological-functional connection score and structural modeling. We applied this approach to analyze the lymph node metastasis (LNM) process in breast cancer. The functional enrichment analysis showed that both inter-modular edges and date hubs play important roles in cancer metastasis and invasion, and in metastasis hallmarks. The structural mutation analysis suggested that the LNM of breast cancer may be the outcome of the dysfunction of rearranged during transfection (RET) proto-oncogene-related interactions and the non-canonical calcium signaling pathway via an allosteric mutation of RET. We believe that the proposed method can provide new insights into disease progression such as cancer metastasis.

PyInteraph2 and PyInKnife2 to Analyze Networks in Protein Structural Ensembles

Due to the complex nature of noncovalent interactions and their long-range effects, analyzing protein conformations using network theory can be enlightening. Protein Structure Networks (PSNs) provide a convenient formalism to study protein structures in relation to essential properties such as key residues for structural stability, allosteric communication, and the effects of modifications of the protein. PSNs can be defined according to very different principles, and the available tools have limitations in input formats, supported models, and version control. Other outstanding problems are related to the definition of network cutoffs and the assessment of the stability of the network properties. The protein science community could benefit from a common framework to carry out these analyses and make them easier to reproduce, reuse, and evaluate. We here provide two open-source software packages, PyInteraph2 and PyInKnife2, to implement and analyze PSNs in a reproducible and documented manner. PyInteraph2 interfaces with multiple formats for protein ensembles and incorporates different network models with the possibility of integrating them into a macronetwork and performing various downstream analyses, including hubs, connected components, and several other centrality measures, and visualizes the networks or further analyzes them thanks to compatibility with Cytoscape.PyInKnife2 that supports the network models implemented in PyInteraph2. It employs a jackknife resampling approach to estimate the convergence of network properties and streamline the selection of distance cutoffs. We foresee that the modular structure of the code and the supported version control system will promote the transition to a community-driven effort, boost reproducibility, and establish common protocols in the PSN field. As developers, we will guarantee the introduction of new functionalities and maintenance, assistance, and training of new contributors.

Nephroprotective mechanisms of Rhizoma Chuanxiong and Radix et Rhizoma Rhei against acute renal injury and renal fibrosis based on network pharmacology and experimental validation

The molecular mechanisms of Rhizoma Chuanxiong (Chuanxiong, CX) and Rhei Radix et Rhizoma (Dahuang, DH) in treating acute kidney injury (AKI) and subsequent renal fibrosis (RF) were investigated in this study by applying network pharmacology and experimental validation. The results showed that aloe-emodin, (-)-catechin, beta-sitosterol, and folic acid were the core active ingredients, and TP53, AKT1, CSF1R, and TGFBR1 were the core target genes. Enrichment analyses showed that the key signaling pathways were the MAPK and IL-17 signaling pathways. In vivo experiments confirmed that Chuanxiong and Dahuang pretreatments significantly inhibited the levels of SCr, BUN, UNAG, and UGGT in contrast media-induced acute kidney injury (CIAKI) rats (p < 0.001). The results of Western blotting showed that compared with the control group, the protein levels of p-p38/p38 MAPK, p53, and Bax in the contrast media-induced acute kidney injury group were significantly increased, and the levels of Bcl-2 were significantly reduced (p < 0.001). Chuanxiong and Dahuang interventions significantly reversed the expression levels of these proteins (p < 0.01). The localization and quantification of p-p53 expression in immunohistochemistry technology also support the aforementioned results. In conclusion, our data also suggest that Chuanxiong and Dahuang may inhibit tubular epithelial cell apoptosis and improve acute kidney injury and renal fibrosis by inhibiting p38 MAPK/p53 signaling.

The effect of 5-α reductase inhibitor on Th1, Th2, and Th17 cell-related inflammatory response in BPH

OBJECTIVE

To investigate the effect of 5-α reductase inhibitor on the expression of inflammation-related cytokines in Benign prostatic hyperplasia (BPH) specimens after transurethral prostatic resection (TUR-P).

METHODS

We prospectively examined the expression of inflammation-related cytokines with immunohistochemistry in the paraffin blocks of 60 patients who underwent TUR-P. 30 cases in the 5-α-reductase inhibitor group were treated with finasteride, 5 mg qd, for more than 6 months; 30 cases in the control group were not treated with medicine before operation. HE staining was used to analyze the difference of inflammation reaction between the two groups, and immunohistochemical staining was used to analyze the effect of 5-α reductase inhibitor on the expression of B-cell lymphoma-2 (Bcl-2), Interleukin-2 (IL-2), Interferon-γ (IFN-γ), Interleukin-4 (IL-4), Interleukin-6 (IL-6), Interleukin-17 (IL-17), Interleukin-21 (IL-21) and Interleukin-23 (IL-23) in prostatic tissue.

RESULTS

There was no statistical difference in the location, range and degree of inflammation between the two groups (P > 0.05). When IL-17 expression was low, there was statistical difference between the two groups (P < 0.05). Bcl-2 expression was positively correlated with IL-2, IL-4, IL-6 and IFN-γ (P < 0.05). There was no statistical difference in the expression of IL-21, IL-23 and high expression of IL-17 between the two groups (P > 0.05).

CONCLUSIONS

5-α Reductase inhibitor can inhibit the expression of Bcl-2 in prostatic tissue and the inflammatory response related to T-helper cell 1 (Th1) and T-helper cell 2 (Th2) cells. However, it did not affect Th17 cell-related inflammatory response.

Estrogen-dependent activation of NCOA3 couples with p300 and NF-κB to mediate antiapoptotic genes in ER-positive breast cancer cells

Circumvention of apoptosis by the elevation of antiapoptotic proteins is an important cause of carcinogenesis. The induction of antiapoptotic genes, including B-cell CLL/lymphoma 2 (BCL2), BCL2 related protein A1 (BCL2A1), BCL2 like 1 (BCL2L1), BCL2L2, and myeloid cell leukemia 1 (MCL1), has been observed in multiple cancers, including breast cancer. However, the underlying mechanisms of their overexpression are still being investigated. Here, we revealed that BCL2, BCL2A1, BCL2L2, and MCL1 but not BCL2L1 were overexpressed in estrogen receptor (ER)-positive breast cancer cells and clinical biopsies. Stimulation with estrogen in ER-positive cell lines resulted in a dose-dependent increase in BCL2, BCL2A1, BCL2L2, and MCL1 mRNA levels. Molecular investigation revealed that nuclear factor kappa B (NF-κB) recruited histone acetyltransferase p300 and nuclear receptor coactivator 3 (NCOA3) to form a transcriptional complex. This complex docked the promoters of BCL2, BCL2A1, BCL2L2, and MCL1 and activated their expression. Interestingly, estrogen exposure dose-dependently activated NCOA3. Depletion of the NCOA3-p300-NF-κB components or blockage of NCOA3 function with inhibitors (gossypol and bufalin) in ER-positive cells suppressed BCL2, BCL2A1, BCL2L2, and MCL1 expression, while also decreasing cell viability, colony formation, cell invasion, and tumor growth. Collectively, our results demonstrate an upstream signaling that activates four antiapoptotic genes in ER-positive breast cancer cells. Importantly, our results also imply that targeting NCOA3 or blocking the assembly of the NCOA3-p300-NF-κB complex may be promising therapeutic strategies for treating ER-positive breast cancer.

Mating-Induced Common and Sex-Specific Behavioral, Transcriptional Changes in the Moth Fall Armyworm (Spodoptera frugiperda, Noctuidae, Lepidoptera) in Laboratory

The intermediate process between mating and postmating behavioral changes in insects is still poorly known. Here, we studied mating-induced common and sex-specific behavioral and transcriptional changes in both sexes of Spodoptera frugiperda and tested whether the transcriptional changes are linked to postmating behavioral changes in each sex. A behavioral study showed that mating caused a temporary suppression of female calling and male courting behavior, and females did not lay eggs until the next day after the first mating. The significant differences on daily fecundity under the presence of males or not, and the same or novel males, suggest that females may intentionally retain eggs to be fertilized by novel males or to be fertilized competitively by different males. RNA sequencing in females revealed that there are more reproduction related GO (gene ontology) terms and KEGG (Kyoto encyclopedia of genes and genomes) pathways (mainly related to egg and zygote development) enriched to upregulated DEGs (differentially expressed genes) than to downregulated DEGs at 0 and 24 h postmating. In males, however, mating induced DEGs did not enrich any reproduction related terms/pathways, which may be because male reproductive bioinformatics is relatively limited in moths. Mating also induced upregulation on soma maintenance (such as immune activity and stress reaction) related processes in females at 0, 6 and 24 h postmating. In males, mating also induced upregulation on soma maintenance related processes at 0 h postmating, but induced downregulation on these processes at 6 and 24 h postmating. In conclusion, this study demonstrated that mating induced sex-specific postmating behavioral and transcriptional changes in both sexes of S. frugiperda and suggested that the transcriptional changes are correlated with postmating physiological and behavioral changes in each sex.

HRK inhibits colorectal cancer cells proliferation by suppressing the PI3K/AKT/mTOR pathway

Background

As one of the most common malignant tumor, colorectal cancer (CRC) continues to have a high incidence and mortality rate. HRK belongs to the BCL-2 protein family, which has been shown to have antitumor effects in prostate cancer. However, its role in colorectal cancer is not yet known.

Methods

In this study, we verified the expression levels of HRK in colorectal cancer tissues by public database search as well as immunohistochemistry. Next, we analyzed HRK expression levels in CRC tissues,adjacent non-cancerous tissues, cell lines and normal intestinal epithelial cells by qPCR and Western blotting. CCK-8 proliferation assays, transwell assays, wound healing assays, colony assays and flow cytometry were performed to clarified the effect of HRK on CRC cells. Western blotting and rescue experiments were used to determine the role of HRK in regulating PI3K/AKT/mTOR signaling pathway.

Results

HRK expression was lower in CRC tissues and cell lines. Gain and loss of function experiments showed that HRK decreased proliferation, invasion and migration of CRC cells. Low expression of HRK inhibited CRC cell apoptosis as well as activated the PI3K/AKT/mTOR signaling pathway. In addition, rapamycin inhibits the activation of PI3K/AKT/mTOR signaling pathway and reverses HRK-induced alterations in cell biological functions.

Conclusion

Our study demonstrates that HRK is lowly expressed in colorectal cancer tissues. And for the first time, HRK was shown to promote apoptosis and inhibit proliferation of colorectal cancer cells by inhibiting PI3K/AKT/mTOR signaling pathway. HRK represents a potential target for the treatment of CRC.

Bcl-xL as prognostic marker and potential therapeutic target in cholangiocarcinoma

Intrahepatic, perihilar, and distal cholangiocarcinoma (iCCA, pCCA, dCCA) are highly malignant tumours with increasing mortality rates due to therapy resistances. Among the mechanisms mediating resistance, overexpression of anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-x_L , Mcl-1) is particularly important. In this study, we investigated whether antiapoptotic protein patterns are prognostically relevant and potential therapeutic targets in CCA. Bcl-2 proteins were analysed in a pan-cancer cohort from the NCT/DKFZ/DKTK MASTER registry trial (n = 1140, CCA n = 72) via RNA-sequencing and transcriptome-based protein activity interference revealing high ranks of CCA for Bcl-x_L and Mcl-1. Expression of Bcl-x_L , Mcl-1, and Bcl-2 was assessed in human CCA tissue and cell lines compared with cholangiocytes by immunohistochemistry, immunoblotting, and quantitative-RT-PCR. Immunohistochemistry confirmed the upregulation of Bcl-x_L and Mcl-1 in iCCA tissues. Cell death of CCA cell lines upon treatment with specific small molecule inhibitors of Bcl-x_L (Wehi-539), of Mcl-1 (S63845), and Bcl-2 (ABT-199), either alone, in combination with each other or together with chemotherapeutics was assessed by flow cytometry. Targeting Bcl-x_L induced cell death and augmented the effect of chemotherapy in CCA cells. Combined inhibition of Bcl-x_L and Mcl-1 led to a synergistic increase in cell death in CCA cell lines. Correlation between Bcl-2 protein expression and survival was analysed within three independent patient cohorts from cancer centers in Germany comprising 656 CCA cases indicating a prognostic value of Bcl-x_L in CCA depending on the CCA subtype. Collectively, these observations identify Bcl-x_L as a key protein in cell death resistance of CCA and may pave the way for clinical application.

In silico investigation of nonsynonymous single nucleotide polymorphisms in BCL2 apoptosis regulator gene to design novel protein-based drugs against cancer

BCL2 apoptosis regulator gene encodes Bcl-2 pro-survival protein, which plays an important role to evade apoptosis in various cancers. Moreover, single nucleotide polymorphisms (SNPs) in the BCL2 gene can be nonsynonymous (nsSNPs), which might affect the protein stability and probably its function. Therefore, we implement cutting-edge computational techniques based on the Spherical Polar Fourier and Monte-Carlo algorithms to investigate the impact of these SNPs on the B cell lymphoma-2 (Bcl-2) stability and therapeutic potential of protein-based molecules to inhibit this protein. As a result, we identified two nsSNPs (Q118R and R129C) to be deleterious and highly conserved, having a negative effect on protein stability. Additionally, molecular docking and molecular dynamics simulations confirmed the decreased binding affinity of mutated Bcl-2 variants to bind three-helix bundle protein inhibitor as these mutations occurred in the protein-protein binding site. Overall, this computational approach investigating nsSNPs provides a useful basis for designing novel molecules to inhibit Bcl-2 pro-survival pathway in malignant cells.

Rat Mammary carcinoma susceptibility 3 (Mcs3) pleiotropy, socioenvironmental interaction, and comparative genomics with orthologous human 15q25.1-25.2

Genome-wide association studies of breast cancer susceptibility have revealed risk-associated genetic variants and nominated candidate genes; however, the identification of causal variants and genes is often undetermined by genome-wide association studies. Comparative genomics, utilizing Rattus norvegicus strains differing in susceptibility to mammary tumor development, is a complimentary approach to identify breast cancer susceptibility genes. Mammary carcinoma susceptibility 3 (Mcs3) is a Copenhagen (COP/NHsd) allele that confers resistance to mammary carcinomas when introgressed into a mammary carcinoma susceptible Wistar Furth (WF/NHsd) genome. Here, Mcs3 was positionally mapped to a 7.2-Mb region of RNO1 spanning rs8149408 to rs107402736 (chr1:143700228-150929594, build 6.0/rn6) using WF.COP congenic strains and 7,12-dimethylbenz(a)anthracene-induced mammary carcinogenesis. Male and female WF.COP-Mcs3 rats had significantly lower body mass compared to the Wistar Furth strain. The effect on female body mass was observed only when females were raised in the absence of males indicating a socioenvironmental interaction. Furthermore, female WF.COP-Mcs3 rats, raised in the absence of males, did not develop enhanced lobuloalveolar morphologies compared to those observed in the Wistar Furth strain. Human 15q25.1-25.2 was determined to be orthologous to rat Mcs3 (chr15:80005820-82285404 and chr15:83134545-84130720, build GRCh38/hg38). A public database search of 15q25.1-25.2 revealed genome-wide significant and nominally significant associations for body mass traits and breast cancer risk. These results support the existence of a breast cancer risk-associated allele at human 15q25.1-25.2 and warrant ultrafine mapping of rat Mcs3 and human 15q25.1-25.2 to discover novel causal genes and variants.

The Cancermuts software package for the prioritization of missense cancer variants: a case study of AMBRA1 in melanoma

Cancer genomics and cancer mutation databases have made an available wealth of information about missense mutations found in cancer patient samples. Contextualizing by means of annotation and predicting the effect of amino acid change help identify which ones are more likely to have a pathogenic impact. Those can be validated by means of experimental approaches that assess the impact of protein mutations on the cellular functions or their tumorigenic potential. Here, we propose the integrative bioinformatic approach Cancermuts, implemented as a Python package. Cancermuts is able to gather known missense cancer mutations from databases such as cBioPortal and COSMIC, and annotate them with the pathogenicity score REVEL as well as information on their source. It is also able to add annotations about the protein context these mutations are found in, such as post-translational modification sites, structured/unstructured regions, presence of short linear motifs, and more. We applied Cancermuts to the intrinsically disordered protein AMBRA1, a key regulator of many cellular processes frequently deregulated in cancer. By these means, we classified mutations of AMBRA1 in melanoma, where AMBRA1 is highly mutated and displays a tumor-suppressive role. Next, based on REVEL score, position along the sequence, and their local context, we applied cellular and molecular approaches to validate the predicted pathogenicity of a subset of mutations in an in vitro melanoma model. By doing so, we have identified two AMBRA1 mutations which show enhanced tumorigenic potential and are worth further investigation, highlighting the usefulness of the tool. Cancermuts can be used on any protein targets starting from minimal information, and it is available at https://www.github.com/ELELAB/cancermuts as free software.

Regulation of Apoptosis and Autophagy During Anoxia in the Freshwater Crayfish, Faxonius virilis

The ability of an animal to survive prolonged periods of oxygen deprivation is a critical area of study, both in terms of its importance to better understanding the physiology of these incredible animals and to its potential applicability to medical fields. The freshwater crayfish, Faxonius virilis, is one such animal capable of resisting anoxia, but it remains understudied and much of the metabolic mechanisms underlying this anoxia tolerance remain largely unprofiled. This study examines the activity and regulation of apoptosis and autophagy in F. virilis in response to 20-h anoxia. Apoptosis signaling was assessed through pro- and anti-apoptosis targets, whereas autophagy was assessed via expression response of multiple autophagy proteins. An anoxia-triggered, tissue-specific result arose, potentially based on the importance of individual organ integrity through hypometabolism. Tail muscle, which showed increased expression profiles of all three target groups, contrasted with hepatopancreas, which appeared to not be susceptible to either apoptotic or autophagic signaling during anoxia. This is likely due to the importance of the hepatopancreas, given that apoptosis or autophagy of this organ at any significant level could be fatal to the organism. The data provides a comprehensive overview of the responses and integration of multiple stress-responsive signaling pathways in F. virilis that provide a novel contribution to our understanding of pro-survival mechanisms supporting invertebrate anoxia resistance.

Cancer-related Mutations with Local or Long-range Effects on an Allosteric Loop of p53

The tumor protein 53 (p53) is involved in transcription-dependent and independent processes. Several p53 variants related to cancer have been found to impact protein stability. Other variants, on the contrary, might have little impact on structural stability and have local or long-range effects on the p53 interactome. Our group previously identified a loop in the DNA binding domain (DBD) of p53 (residues 207-213) which can recruit different interactors. Experimental structures of p53 in complex with other proteins strengthen the importance of this interface for protein-protein interactions. We here characterized with structure-based approaches somatic and germline variants of p53 which could have a marginal effect in terms of stability and act locally or allosterically on the region 207-213 with consequences on the cytosolic functions of this protein. To this goal, we studied 1132 variants in the p53 DBD with structure-based approaches, accounting also for protein dynamics. We focused on variants predicted with marginal effects on structural stability. We then investigated each of these variants for their impact on DNA binding, dimerization of the p53 DBD, and intramolecular contacts with the 207-213 region. Furthermore, we identified variants that could modulate long-range the conformation of the region 207-213 using a coarse-grain model for allostery and all-atom molecular dynamics simulations. Our predictions have been further validated using enhanced sampling methods for 15 variants. The methodologies used in this study could be more broadly applied to other p53 variants or cases where conformational changes of loop regions are essential in the function of disease-related proteins.

Structural Details of BH3 Motifs and BH3-Mediated Interactions: an Updated Perspective

Apoptosis is a mechanism of programmed cell death crucial in organism development, maintenance of tissue homeostasis, and several pathogenic processes. The B cell lymphoma 2 (BCL2) protein family lies at the core of the apoptotic process, and the delicate balance between its pro- and anti-apoptotic members ultimately decides the cell fate. BCL2 proteins can bind with each other and several other biological partners through the BCL2 homology domain 3 (BH3), which has been also classified as a possible Short Linear Motif and whose distinctive features remain elusive even after decades of studies. Here, we aim to provide an updated overview of the structural features characterizing BH3s and BH3-mediated interactions (with a focus on human proteins), elaborating on the plasticity of BCL2 proteins and the motif properties. We also discussed the implication of these findings for the discovery of interactors of the BH3-binding groove of BCL2 proteins and the design of mimetics for therapeutic purposes.

The effect of the PLIN1 gene on the metabolism and mitochondria of porcine skeletal muscle satellite cells

BACKGROUND

Perilipin 1 (PLIN1) is a lipid droplet scaffolding protein that plays a regulatory role in fat decomposition and mitochondrial function.

OBJECTIVE

In this study, the effects of PLIN1 gene knockout (PLIN1-KO) and PLIN1 gene overexpression (PLIN1-EX) on cell metabolism and mitochondrial function in porcine skeletal muscle satellite cells were assessed.

METHODS

Porcine skeletal muscle satellite cells were used as the control group (NC). The expression of mitochondrial function-related proteins was detected by western blot. Apoptosis, cell cycle, mitochondrial function-related indices, mitochondrial structure, and morphology were measured by flow cytometry.

RESULTS

Our results demonstrated that stable expression of the PLIN1 gene in skeletal muscle satellite cells is critical to maintaining cell metabolism and mitochondrial function. After knockout and overexpression of the PLIN1 gene, the anti-apoptotic ability of cells was enhanced, and the metabolic activity of the cells was accelerated, but at the cost of mitochondrial structural damage, reduction in the number of mitochondria, and decreased mitochondrial function.

CONCLUSION

This study explored the effect of the PLIN1 gene on the mitochondria and metabolism of porcine skeletal muscle satellite cells and provided a theoretical basis for the subsequent study of the effects of PLIN1 on muscle tissue development and meat quality.

An Integrated Approach Based on Network Analysis Combined With Experimental Verification Reveals PI3K/Akt/Nrf2 Signaling Is an Important Way for the Anti-Myocardial Ischemia Activity of Yi-Qi-Tong-Luo Capsule

Background: Yiqi-Tongluo Capsule (YTC) is a Chinese traditional patent medicine that has been used in the treatment of myocardial ischemia (MI). However, its molecular mechanisms against MI have not been clear. Methods: Network analysis and experimental verification were used to explore the potential molecular mechanisms of YTC for MI treatment. Firstly, the main components in the capsules and the potential targets of these components were predicted by online databases. The MI related genes were collected from Genecards and Online Mendelian Inheritance in Man (OMIM) databases. The drug targets and disease targets were intersected, and then the protein-protein interaction (PPI) and Drug-Molecular-Target-Disease Network (DMTD) were constructed, and GO enrichment analysis and KEGG pathway enrichment analysis were performed. Based on the H₂O₂-stimulated H9c2 cells, flow cytometry, western blot (WB) and immunofluorescence experiments were performed to verify the network analysis prediction. Results: A total of 100 active components and 165 targets of YTC were predicted, in which there were 109 targets intersected with the targets of MI. GO and KEGG analysis showed that these potential targets were related to a variety of biological processes and molecular mechanisms, including oxidative stress and PI3K/AKT pathway. Astragaloside IV (AS IV) and paeoniflorin (PAE) might be the main active components in YTC. The results of cell counting kit-8 (CCK-8) showed that YTC alleviated the damage of H₂O₂ to H9c2 cells. The results of flow cytometry, DAPI staining and JC-1 probe showed that YTC alleviated H₂O₂ induced apoptosis in H9c2 cells. In addition, YTC reduced the level of intracellular superoxide anion, increased the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and reduced the content of malondialdehyde (MDA) in H₂O₂-induced H9c2 cells. The results of immunofluorescence and WB showed that the phosphorylation of PI3K and Akt were increased, the expression of Bcl-2 was up-regulated and the expression of cleaved caspase-3 and Bax were down-regulated. Besides, the nuclear translocation of Nrf2 were increased. Conclusion: In conclusion, the results of this study showed that YTC might alleviate MI by suppressing apoptosis induced by oxidative stress via the PI3K/Akt/Nrf2 signal pathway.

Tetramethylpyrazine: An Active Ingredient of Chinese Herbal Medicine With Therapeutic Potential in Acute Kidney Injury and Renal Fibrosis

As an increasing public health concern worldwide, acute kidney injury (AKI) is characterized by rapid deterioration of kidney function. Although continuous renal replacement therapy (CRRT) could be used to treat severe AKI, effective drug treatment methods for AKI are largely lacking. Tetramethylpyrazine (TMP) is an active ingredient of Chinese herb Ligusticum wallichii (Chuan Xiong) with antioxidant and anti-inflammatory functions. In recent years, more and more clinical and experimental studies suggest that TMP might effectively prevent AKI. The present article reviews the potential mechanisms of TMP against AKI. Through search and review, a total of 23 studies were finally included. Our results indicate that the undergoing mechanisms of TMP preventing AKI are mainly related to reducing oxidative stress injury, inhibiting inflammation, preventing apoptosis of intrinsic renal cells, and regulating autophagy. Meanwhile, given that AKI and chronic kidney disease (CKD) are very tightly linked by each other, and AKI is also an important inducement of CKD, we thus summarized the potential of TMP impeding the progression of CKD through anti-renal fibrosis.

MicroRNA-489 Promotes the Apoptosis of Cardiac Muscle Cells in Myocardial Ischemia-Reperfusion Based on Smart Healthcare

With the development of information technology, the concept of smart healthcare has gradually come to the fore. Smart healthcare uses a new generation of information technologies, such as the Internet of Things (loT), big data, cloud computing, and artificial intelligence, to transform the traditional medical system in an all-around way, making healthcare more efficient, more convenient, and more personalized. miRNAs can regulate the proliferation, differentiation, and apoptosis of human cells. Relevant studies have also shown that miRNAs may play a key role in the occurrence and development of myocardial ischemia-reperfusion injury (MIRI). This study aims to explore the effects of miR-489 in MIRI. In this study, miR-489 expression in a myocardial ischemia-reperfusion animal model and H9C2 cells induced by H/R was detected by qRT-PCR. The release of lactate dehydrogenase (LDH) and the activity of creatine kinase (CK) was detected after miR-489 knockdown in H9C2 cells induced by H/R. The apoptosis of H9C2 cells and animal models were determined by ELISA. The relationship between miR-489 and SPIN1 was verified by a double fluorescence reporter enzyme assay. The expression of the PI3K/AKT pathway-related proteins was detected by Western blot. Experimental results showed that miR-489 was highly expressed in cardiac muscle cells of the animal model and in H9C2 cells induced by H/R of the myocardial infarction group, which was positively associated with the apoptosis of cardiac muscle cells with ischemia-reperfusion. miR-489 knockdown can reduce the apoptosis of cardiac muscle cells caused by ischemia-reperfusion. In downstream targeting studies, it was found that miR-489 promotes the apoptosis of cardiac muscle cells after ischemia-reperfusion by targeting the inhibition of the SPIN1-mediated PI3K/AKT pathway. In conclusion, high expression of miR-489 is associated with increased apoptosis of cardiac muscle cells after ischemia-reperfusion, which can promote the apoptosis after ischemia-reperfusion by targeting the inhibition of the SPIN1-mediated PI3K/AKT pathway. Therefore, miR-489 can be one of the potential therapeutic targets for reducing the apoptosis of cardiac muscle cells after ischemia-reperfusion.

Making Sense of Antisense Oligonucleotide Therapeutics Targeting Bcl-2

The B-cell lymphoma 2 (Bcl-2) family, comprised of pro- and anti-apoptotic proteins, regulates the delicate balance between programmed cell death and cell survival. The Bcl-2 family is essential in the maintenance of tissue homeostasis, but also a key culprit in tumorigenesis. Anti-apoptotic Bcl-2, the founding member of this family, was discovered due to its dysregulated expression in non-Hodgkin’s lymphoma. Bcl-2 is a central protagonist in a wide range of human cancers, promoting cell survival, angiogenesis and chemotherapy resistance; this has prompted the development of Bcl-2-targeting drugs. Antisense oligonucleotides (ASO) are highly specific nucleic acid polymers used to modulate target gene expression. Over the past 25 years several Bcl-2 ASO have been developed in preclinical studies and explored in clinical trials. This review will describe the history and development of Bcl-2-targeted ASO; from initial attempts, optimizations, clinical trials undertaken and the promising candidates at hand.

Paradoxical implication of BAX/BAK in the persistence of tetraploid cells

Pro-apoptotic multi-domain proteins of the BCL2 family such as BAX and BAK are well known for their important role in the induction of mitochondrial outer membrane permeabilization (MOMP), which is the rate-limiting step of the intrinsic pathway of apoptosis. Human or mouse cells lacking both BAX and BAK (due to a double knockout, DKO) are notoriously resistant to MOMP and cell death induction. Here we report the surprising finding that BAX/BAK DKO cells proliferate less than control cells expressing both BAX and BAK (or either BAX or BAK) when they are driven into tetraploidy by transient exposure to the microtubule inhibitor nocodazole. Mechanistically, in contrast to their BAX/BAK-sufficient controls, tetraploid DKO cells activate a senescent program, as indicated by the overexpression of several cyclin-dependent kinase inhibitors and the activation of β-galactosidase. Moreover, DKO cells manifest alterations in ionomycin-mobilizable endoplasmic reticulum (ER) Ca2+ stores and store-operated Ca2+ entry that are affected by tetraploidization. DKO cells manifested reduced expression of endogenous sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (Serca2a) and transfection-enforced reintroduction of Serca2a, or reintroduction of an ER-targeted variant of BAK into DKO cells reestablished the same pattern of Ca2+ fluxes as observed in BAX/BAK-sufficient control cells. Serca2a reexpression and ER-targeted BAK also abolished the tetraploidy-induced senescence of DKO cells, placing ER Ca2+ fluxes downstream of the regulation of senescence by BAX/BAK. In conclusion, it appears that BAX/BAK prevent the induction of a tetraploidization-associated senescence program. Speculatively, this may contribute to the low incidence of cancers in BAX/BAK DKO mice and explain why human cancers rarely lose the expression of both BAX and BAK.

The Stress-Inducible BCL2A1 Is Required for Ovarian Cancer Metastatic Progression in the Peritoneal Microenvironment

Emerging evidence indicates that hypoxia plays a critical role in governing the transcoelomic metastasis of ovarian cancer. Hence, targeting hypoxia may be a promising approach to prevent the metastasis of ovarian cancer. Here, we report that BCL2A1, a BCL2 family member, acts as a hypoxia-inducible gene for promoting tumor progression in ovarian cancer peritoneal metastases. We demonstrated that BCL2A1 was induced not only by hypoxia but also other physiological stresses through NF-κB signaling and then was gradually reduced by the ubiquitin-proteasome pathway in ascites-derived ovarian cancer cells. The upregulated BCL2A1 was frequently found in advanced metastatic ovarian cancer cells, suggesting its clinical relevance in ovarian cancer metastatic progression. Functionally, BCL2A1 enhanced the foci formation ability of ovarian cancer cells in a stress-conditioned medium, colony formation in an ex vivo omental tumor model, and tumor dissemination in vivo. Under stress conditions, BCL2A1 accumulated and colocalized with mitochondria to suppress intrinsic cell apoptosis by interacting with the BH3-only subfamily BCL2 members HRK/BAD/BID in ovarian cancer cells. These findings indicate that BCL2A1 is an early response factor that maintains the survival of ovarian cancer cells in the harsh tumor microenvironment.

The Role of miRNA in the Pathophysiology of Neuroendocrine Tumors

Neuroendocrine tumors (NETs) represent a tumor group that is both rare and heterogeneous. Prognosis is largely determined by the tumor grading and the site of the primary tumor and metastases. Despite intensive research efforts, only modest advances in diagnostic and therapeutic approaches have been achieved in recent years. For patients with non-respectable tumor stages, prognosis is poor. In this context, the development of novel diagnostic tools for early detection of NETs and prediction of tumor response to therapy as well as estimation of the overall prognosis would greatly improve the clinical management of NETs. However, identification of novel diagnostic molecules is hampered by an inadequate understanding of the pathophysiology of neuroendocrine malignancies. It has recently been demonstrated that microRNA (miRNA), a family of small RNA molecules with an established role in the pathophysiology of quite different cancer entities, may also play a role as a biomarker. Here, we summarize the available knowledge on the role of miRNAs in the development of NET and highlight their potential use as serum-based biomarkers in the context of this disease. We discuss important challenges currently preventing their use in clinical routine and give an outlook on future directions of miRNA research in NET.

Expanding the phenotype of E318K (c.952G > A) MITF germline mutation carriers: case series and review of the literature

Background

The microphthalmia-associated transcription factor gene (MITF) belongs to the MYC supergene family and plays an important role in melanocytes’ homeostasis. Individuals harboring MITF germline pathogenic variants are at increased risk of developing cancer, most notably melanoma and renal cell carcinoma.

Case presentation

We describe a cohort of ten individuals who harbor the same MITF c.952G > A (p.Glu 318Lys), or p.E318K, germline pathogenic variant. Six carriers developed at least one malignancy (4 cases of breast cancer; 1 cervical cancer; 1 colon cancer; 1 melanoma; 1 ovarian/fallopian tube cancer). A significant phenotypic heterogeneity was found among these individuals and their relatives. Breast cancer was, overall, the most frequent malignancy observed in this case series, with 13 occurrences of 60 (21.67 %) total cancer cases described among the probands and their relatives.

Conclusions

Our retrospective analysis data raise the hypothesis of a possible association of the MITF p.E318K pathogenic variant with an increased risk of breast cancer.

Exploring the Allosteric Territory of Protein Function

While the pervasiveness of allostery in proteins is commonly accepted, we further show the generic nature of allosteric mechanisms by analyzing here transmembrane ion-channel viroporin 3a and RNA-dependent RNA polymerase (RdRp) from SARS-CoV-2 along with metabolic enzymes isocitrate dehydrogenase 1 (IDH1) and fumarate hydratase (FH) implicated in cancers. Using the previously developed structure-based statistical mechanical model of allostery (SBSMMA), we share our experience in analyzing the allosteric signaling, predicting latent allosteric sites, inducing and tuning targeted allosteric response, and exploring the allosteric effects of mutations. This, yet incomplete list of phenomenology, forms a complex and unique allosteric territory of protein function, which should be thoroughly explored. We propose a generic computational framework, which not only allows one to obtain a comprehensive allosteric control over proteins but also provides an opportunity to approach the fragment-based design of allosteric effectors and drug candidates. The advantages of allosteric drugs over traditional orthosteric compounds, complemented by the emerging role of the allosteric effects of mutations in the expansion of the cancer mutational landscape and in the increased mutability of viral proteins, leave no choice besides further extensive studies of allosteric mechanisms and their biomedical implications.

Structural Model for Recruitment of RIT1 to the LZTR1 E3 Ligase: Evidences from an Integrated Computational Approach

Leucine-zipper transcription regulator 1 (LZTR1) is a highly mutated tumor suppressor gene, involved in the pathogenesis of several cancer types and developmental disorders. In proteasomal degradation, it acts as an adaptor protein responsible for the recognition and recruitment of substrates to be ubiquitinated in Cullin3-RING ligase E3 (CRL3) machinery. LZTR1 belongs to the BTB-Kelch family, a multi-domain protein where the Kelch propeller plays as the substrate recognition region and for which no experimental structure has been solved. Recently, large effort mutational analyses pointed to the role of disease-associated LZTR1 mutations in the RAS/MAPK signaling pathway and RIT1, a small Ras-related GTPase protein, has been identified by mass spectroscopy to interact with LZTR1. Hence, a better understanding of native structure, molecular mechanism, and substrate specificity would help clarifying the role of LZTR1 in pathological diseases, thus promoting advancement in the development of novel therapeutic strategies. Here, we address the interaction model between adaptor LZTR1 and substrate RIT1 by applying an integrated computational approach, including molecular modeling and docking techniques. We observe that the interaction model LZTR1-RIT1 is stabilized by an electrostatic bond network established between the two protein surfaces, which is reminiscent of homologous ubiquitin ligases complexes. Then, running MD simulations, we characterize differential conformational dynamics of the multi-domain LZTR1, offering interesting implications on the mechanistic role of specific point mutations. We identify G248R and R283Q as damaging mutations involved in the recognition process of the substrate RIT1 and R412C as a possible allosteric mutation from the Kelch to the C-term BTB-domain. Our findings provide important structural insights on targeting CRL3s for drug discovery.

The Complex Roles and Therapeutic Implications of m6A Modifications in Breast Cancer

Accumulating evidence indicates that N⁶-methyladenosine (m⁶A), which directly regulates mRNA, is closely related to multiple biological processes and the progression of different malignancies, including breast cancer (BC). Studies of the aberrant expression of m⁶A mediators in BC revealed that they were associated with different BC subtypes and functions, such as proliferation, apoptosis, stemness, the cell cycle, migration, and metastasis, through several factors and signaling pathways, such as Bcl-2 and the PI3K/Akt pathway, among others. Several regulators that target m⁶A have been shown to have anticancer effects. Fat mass and obesity-associated protein (FTO) was identified as the first m⁶A demethylase, and a series of inhibitors that target FTO were reported to have potential for the treatment of BC by inhibiting cell proliferation and promoting apoptosis. However, the exact mechanism by which m⁶A modifications are regulated by FTO inhibitors remains unknown. m⁶A modifications in BC have only been preliminarily studied, and their mechanisms require further investigation.

Age-related injury responses of human oligodendrocytes to metabolic insults: link to BCL-2 and autophagy pathways

Myelin destruction and oligodendrocyte (OL) death consequent to metabolic stress is a feature of CNS disorders across the age spectrum. Using cells derived from surgically resected tissue, we demonstrate that young (<age 5) pediatric-aged sample OLs are more resistant to in-vitro metabolic injury than fetal O4+ progenitor cells, but more susceptible to cell death and apoptosis than adult-derived OLs. Pediatric but not adult OLs show measurable levels of TUNEL+ cells, a feature of the fetal cell response. The ratio of anti- vs pro-apoptotic BCL-2 family genes are increased in adult vs pediatric (<age 5) mature OLs and in more mature OL lineage cells. Lysosomal gene expression was increased in adult and pediatric compared to fetal OL lineage cells. Cell death of OLs was increased by inhibiting pro-apoptotic BCL-2 gene and autophagy activity. These distinct age-related injury responses should be considered in designing therapies aimed at reducing myelin injury.

Identification of BCL-XL as highly active survival factor and promising therapeutic target in colorectal cancer

Since metastatic colorectal cancer (CRC) is a leading cause of cancer-related death, therapeutic approaches overcoming primary and acquired therapy resistance are an urgent medical need. In this study, the efficacy and toxicity of high-affinity inhibitors targeting antiapoptotic BCL-2 proteins (BCL-2, BCL-XL, and MCL-1) were evaluated. By RNA sequencing analysis of a pan-cancer cohort comprising >1500 patients and subsequent prediction of protein activity, BCL-XL was identified as the only antiapoptotic BCL-2 protein that is overactivated in CRC. Consistently, pharmacologic and genetic inhibition of BCL-XL induced apoptosis in human CRC cell lines. In a combined treatment approach, targeting BCL-XL augmented the efficacy of chemotherapy in vitro, in a murine CRC model, and in human ex vivo derived CRC tissue cultures. Collectively, these data show that targeting of BCL-XL is efficient and safe in preclinical CRC models, observations that pave the way for clinical translation.

Hydroxy-α-sanshool Possesses Protective Potentials on H2O2-Stimulated PC12 Cells by Suppression of Oxidative Stress-Induced Apoptosis through Regulation of PI3K/Akt Signal Pathway

Zanthoxylum bungeanum pericarp is a commonly used herbal medicine in China with effects of anti-inflammatory and analgesic, improving learning and memory ability, while hydroxy-α-sanshool (HAS) is the most important active ingredient of Z. bungeanum pericarps. The purpose of this study was to investigate the neuroprotective effect of HAS and its related possible mechanisms using a H₂O₂-stimulated PC12 cell model. CCK-8 assay results showed that HAS had a significant protective effect on H₂O₂-stimulated PC12 cells without obvious cytotoxicity on normal PC12 cells. Flow cytometry and fluorescence microscope (DAPI staining and DCFH-DA staining) indicated that HAS could reduce the H₂O₂-induced apoptosis in PC12 cells via reduction of intracellular ROS and increase of mitochondrial membrane potential (MMP). Subsequently, results of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) determination suggested that HAS could increase the enzyme activities of SOD, CAT, and GSH-Px whereas it could decrease the MDA contents in H₂O₂-stimulated PC12 cells. Furthermore, the western blotting assays showed that HAS could upregulate the expressions of p-PI3k, Akt, p-Akt, and Bcl-2, while it could downregulate the expressions of cleaved caspase-3 and Bax in H₂O₂-stimulated PC12 cells. Collectively, it could be concluded according to our results that HAS possesses protective potentials on H₂O₂-stimulated PC12 cells through suppression of oxidative stress-induced apoptosis via regulation of PI3K/Akt signal pathway.

Breast Cancer Chemotherapeutic Options: A General Overview on the Preclinical Validation of a Multi-Target Ruthenium(III) Complex Lodged in Nucleolipid Nanosystems

In this review we have showcased the preclinical development of original amphiphilic nanomaterials designed for ruthenium-based anticancer treatments, to be placed within the current metallodrugs approach leading over the past decade to advanced multitarget agents endowed with limited toxicity and resistance. This strategy could allow for new options for breast cancer (BC) interventions, including the triple-negative subtype (TNBC) with poor therapeutic alternatives. BC is currently the second most widespread cancer and the primary cause of cancer death in women. Hence, the availability of novel chemotherapeutic weapons is a basic requirement to fight BC subtypes. Anticancer drugs based on ruthenium are among the most explored and advanced next-generation metallotherapeutics, with NAMI-A and KP1019 as two iconic ruthenium complexes having undergone clinical trials. In addition, many nanomaterial Ru complexes have been recently conceived and developed into anticancer drugs demonstrating attractive properties. In this field, we focused on the evaluation of a Ru(III) complex-named AziRu-incorporated into a suite of both zwitterionic and cationic nucleolipid nanosystems, which proved to be very effective for the in vivo targeting of breast cancer cells (BBC). Mechanisms of action have been widely explored in the context of preclinical evaluations in vitro, highlighting a multitarget action on cell death pathways which are typically deregulated in neoplasms onset and progression. Moreover, being AziRu inspired by the well-known NAMI-A complex, information on non-nanostructured Ru-based anticancer agents have been included in a precise manner.

LncRNA DANCR-miR-758-3p-PAX6 Molecular Network Regulates Apoptosis and Autophagy of Breast Cancer Cells

Objective

This study set out to probe into the effects of long non-coding RNA (LncRNA) differentiation antagonizing non-protein coding RNA (DANCR) on apoptosis and autophagy of breast cancer (BC) cells.

Methods

The expression levels of DANCR, miR-758-3p and paired box 6 (PAX6) in BC tissues and cell lines were detected. The transcription and protein levels of PAX6, apoptosis-related factors (caspase-3, caspase-9, Bax/Bcl-2), and autophagy-related factors (LC3B, Atg5, Beclin-1) in BC cells were detected. The cell proliferation, apoptosis, autophagy and the regulatory relationship between genes and target genes were analyzed.

Results

DANCR and PAX6 were up-regulated in BC tissues and cell lines, while miR-758-3p was opposite. Down-regulating DANCR inhibited the malignant proliferation of BC cells and also promoted apoptosis and autophagy, which showed that caspase-3, caspase-9, Bax/Bcl-2, LC3B, Atg5 transcription and protein levels increased, while Beclin-1 transcription and protein levels decreased. DANCR regulated miR-758-3p in a targeted manner, and its over-expression could weaken the anti-cancer effect of miR-758-3p on BC cells. In addition, miR-758-3p also directly targeted PAX6, and knocking down its expression could weaken the inhibitory effect of down-regulating PAK6 on BC cell apoptosis and autophagy. We also found that DANCR acted as a competitive endogenous RNA sponge miR-758-3p, thus regulating the PAX6 expression.

Conclusion

DANCR-miR-758-3p-PAX6 molecular network plays a key regulatory role in BC cell apoptosis and autophagy, which may provide reference for treating patients.