Non-benzoquinone geldanamycin analogs trigger various forms of death in human breast cancer cells

Emerging role of necroptosis, pyroptosis, and ferroptosis in breast cancer: New dawn for overcoming therapy resistance

Breast cancer (BC) is one of the primary causes of death in women worldwide. The challenges associated with adverse outcomes have increased significantly, and the identification of novel therapeutic targets has become increasingly urgent. Regulated cell death (RCD) refers to a type of cell death that can be regulated by several different biomacromolecules, which is distinctive from accidental cell death (ACD). In recent years, apoptosis, a representative RCD pathway, has gained significance as a target for BC medications. However, tumor cells exhibit avoidance of apoptosis and result in treatment resistance, which emphasizes further studies devoted to alternative cell death processes, namely necroptosis, pyroptosis, and ferroptosis. Here, in this review, we focus on summarizing the crucial signaling pathways of these RCD in BC. We further discuss the molecular mechanism and potentiality in clinical application of several prospective drugs, nanoparticles, and other small compounds targeting different RCD subroutines of BC. We also discuss the benefits of modulating RCD processes on drug resistance and the advantages of combining RCD modulators with conventional treatments in BC. This review will deepen our understanding of the relationship between RCD and BC, and shed new light on future directions to attack cancer vulnerabilities with RCD modulators for therapeutic purposes.

Therapeutic strategies of targeting non-apoptotic regulated cell death (RCD) with small-molecule compounds in cancer

Regulated cell death (RCD) is a controlled form of cell death orchestrated by one or more cascading signaling pathways, making it amenable to pharmacological intervention. RCD subroutines can be categorized as apoptotic or non-apoptotic and play essential roles in maintaining homeostasis, facilitating development, and modulating immunity. Accumulating evidence has recently revealed that RCD evasion is frequently the primary cause of tumor survival. Several non-apoptotic RCD subroutines have garnered attention as promising cancer therapies due to their ability to induce tumor regression and prevent relapse, comparable to apoptosis. Moreover, they offer potential solutions for overcoming the acquired resistance of tumors toward apoptotic drugs. With an increasing understanding of the underlying mechanisms governing these non-apoptotic RCD subroutines, a growing number of small-molecule compounds targeting single or multiple pathways have been discovered, providing novel strategies for current cancer therapy. In this review, we comprehensively summarized the current regulatory mechanisms of the emerging non-apoptotic RCD subroutines, mainly including autophagy-dependent cell death, ferroptosis, cuproptosis, disulfidptosis, necroptosis, pyroptosis, alkaliptosis, oxeiptosis, parthanatos, mitochondrial permeability transition (MPT)-driven necrosis, entotic cell death, NETotic cell death, lysosome-dependent cell death, and immunogenic cell death (ICD). Furthermore, we focused on discussing the pharmacological regulatory mechanisms of related small-molecule compounds. In brief, these insightful findings may provide valuable guidance for investigating individual or collaborative targeting approaches towards different RCD subroutines, ultimately driving the discovery of novel small-molecule compounds that target RCD and significantly enhance future cancer therapeutics.

Pazopanib ameliorates rotenone-induced Parkinsonism in rats by suppressing multiple regulated cell death mechanisms

Parkinson's disease (PD) is characterized by motor impairments and progressive dopaminergic neuronal death in the substantia nigra (SN). Recently, the involvement of other regulated cell death (RCD) machineries has been highlighted in PD. Necroptosis is controlled by p-RIPK1, p-RIPK3, and p-MLKL and negatively regulated by caspase-8. Ferroptosis is characterized by iron overload and accumulation of reactive oxygen species. Interestingly, the molecular chaperone complex HSP90/CDC37 has been reported to directly regulate necroptosis, ferroptosis, and some PD-associated proteins. We investigated the potential anti-necroptotic and anti-ferroptotic effects of the anti-cancer drug pazopanib, uncovering the HSP90/CDC37 complex as a master RCD modulator in rotenone-induced Parkinsonism in rats. Oral administration of 15 mg/kg pazopanib to rotenone-intoxicated rats for three weeks improved motor deficits, debilitated histopathological changes, and increased striatal dopaminergic levels. Pazopanib suppressed LRRK2 and c-Abl. Pazopanib displayed an anti-necroptotic effect through inhibition of the p-RIPK1/p-RIPK3/p-MLKL pathway and activation of caspase-8. Moreover, pazopanib inhibited the ferroptotic p-VEGFR2-PKCβII-PLC-γ-ACSL-4 pathway, iron, 4-HNE, and PTGS2 while increasing GPX-4 and GSH levels. Taken together, the current research sheds light on the repositioning of pazopanib targeting HSP90/CDC37 and its multiple RCD mechanisms, which would offer a new perspective for therapeutic strategies in PD.

An Organofluorine Isoselenocyanate Analogue of Sulforaphane Affects Antimetabolite 5-Fluorouracil's Anticancer Activity: A Perspective for New Combinatory Therapy in Triple-Negative Breast Cancer

Antimetabolites, especially 5-fluorouracil, are commonly used clinically to treat breast, colon, and other cancers. However, their side effects and inefficiency in monotherapy have prompted further searches for new combinations. Thus, the anticancer effect of 5-fluorouracil (5-FU) and the sulforaphane analogue, 4-isoselenocyanato-1-butyl 4'-fluorobenzyl sulfoxide (ISC), were tested in in vitro and in vivo models of triple-negative breast cancer (TNBC) as a new option for this treatment-resistant and aggressive type of breast cancer. A synergic interaction between 5-FU and ISC was observed in the TNBC in vitro model MDA-MB-231 cell line, which led to enhanced antiproliferative effects. The results of in vitro studies were confirmed by in vivo tests, which demonstrated stronger tumor growth inhibition and additive interactions between 5-FU and ISC in the murine TNBC model. Moreover, the results of the body mass and blood analysis showed the safety of the tested combination. The mechanistic study revealed that the combined treatment triggered apoptosis and necrosis, as well as inhibited cell migration.

Prognostic Lysosome-Related Biomarkers for Predicting Drug Candidates in Hepatocellular Carcinoma: An Insilco Analysis

Background

Lysosomes play an important role in enhancing tumorigenesis and chemoresistance in hepatocellular carcinoma (HCC). Therefore, a detailed analysis of the role of lysosome-related genes could improve the poor prognosis of HCC patients.

Methods

Lysosome-associated genes were downloaded from the GO and Genome Enrichment Analysis (GSEA) databases. After analyzing lysosome-associated differentially expressed genes (DEGs) between the TCGA and GTEx cohorts, we used univariate Cox regression, LASSO-Cox regression, stepwise Cox regression, and multivariate Cox regression analyses to build a predictive risk model. The ICGC cohort was used as a test cohort for the prognostic signature's validation. It was also assessed how significantly the signature affected the tumor microenvironment (TME) and sensitivity to immune checkpoint inhibitors. To investigate the expression of this signature in clinical samples, qRT-PCR and immunohistochemistry (IHC) were carried out in 50 normal tissues and 59 HCC tissues.

Results

A total of 894 lysosome-associated genes were obtained. After identifying 113 lysosome-associated DEGs, we constructed a five-gene prognostic signature (RRAGD, AP1M2, CRHBP, NCSTN, and SLCO4C1) that can be effectively applied to the prognostic classification of HCC patients in TCGA and ICGC cohorts. Additionally, we discovered that this signature can affect the proportion of macrophage infiltration in TME. We also evaluated several tumor-sensitive medicines that affect this signature. Finally, we discovered that HCC tissues had lower amounts of CRHBP compared to normal tissues by the qRT-PCR and IHC assay.

Conclusion

We developed and validated a predictive signature of five lysosome-related genes for HCC patients and verified the downregulation of CRHBP expression in clinical samples, which may provide fresh perspectives for customized immunotherapy.

Effect of aspirin on the TNF-α-mediated cell survival and death pathways in breast cancer

OBJECTIVES

Aspirin is an anti-inflammatory drug commonly used as an analgesic and in cardiovascular disorders. However, many studies have highlighted its anti-cancer properties, especially in colorectal, lung, head and neck, and breast cancers. In this work, we tried to study the effect of aspirin on the TNF-α-mediated cell survival and death pathways in two cell lines representing two different subtypes of breast cancer. TNF-α-mediated stimulation of a cell can result in its proliferation via the NF-κB pathway or its death via either apoptosis or a programmed form of necrosis called necroptosis. The latter is believed to come into the picture only when apoptosis is inhibited.

METHODS

In this work, we studied the effect of aspirin on the TNF-α-mediated cell survival pathway and observed a decrease in expression of the NF-κB pathway regulators, its nuclear translocation, and phosphorylation in a dose-dependent manner. The effect of aspirin on the TNF-α-mediated cell death showed significant cytotoxicity at the higher doses (5-20 mM) of aspirin in both the breast cancer cell lines. The effect of aspirin on necroptosis was investigated after stimulating the cells with TNF-α and inhibiting apoptosis using Z-VAD-FMK.

RESULTS

Though no significant effect was noted in breast cancer cell lines, the above protocol successfully induced necroptosis in L929, i.e., a positive control cell line for necroptosis having an intact necroptosis machinery. Even when combined with the chemotherapeutic drugs, the above regime failed to induce any significant necroptosis in breast cancer cells but was found effective in L929.

CONCLUSIONS

Overall, the findings show that while aspirin has the potential to inhibit the TNF-α-mediated cell survival pathway, it does not help sensitize breast cancer cells to necroptotic cell death induction.

Relative refractoriness of breast cancer cells to tumour necrosis factor-α induced necroptosis

Necroptosis, a recently identified programmed cell death pathway, has attracted attention as an alternative route to target apoptosis-resistant cancer cells. The status of the necroptosis pathway in different subtypes of breast cancer has not been well explored. Stimulating the cells by TNF-α can trigger cell survival or death depending on the combination of downstream players involved. In this work, we attempted to induce necroptosis in them using a combination of TNF-α and Z-VAD-FMK with and without chemotherapy. Cell viability, apoptosis, and necroptosis were assessed using MTT and Annexin-V/PI assays, respectively. Gene and protein expression was analysed by qPCR and immunophenotyping. Both the cell lines were resistant to induction of cell death by necroptosis. There was no enhancement in cell death when chemotherapeutic drugs were combined with necroptosis induction. Expression studies showed reduced translational expression of key necroptosis molecules like RIP kinases and MLKL in breast cancer cells compared to positive control cell line L929. Also, cell survival molecules were expressed more in MDA-MB-231 in contrast to death pathway molecules which were expressed more in T47D cells. In this work, the two breast cancer cell lines were observed to be resistant to TNF-α induced necroptosis with or without chemotherapy. Expression of key necroptosis players revealed relative insufficiency of the molecular machinery involved in the above pathway. In our opinion this may be the cause for resistance to necroptosis and novel strategies to upregulate these molecules need to be developed to sensitize the breast cancer cells towards cell death by necroptosis.

HSP90 mediates the connection of multiple programmed cell death in diseases

Heat shock protein (HSP) 90, an important component of the molecular chaperone network, is closely concerned with cellular signaling pathways and stress response by participating in the process of maturation and activation of client proteins, playing a crucial role both in the normal and abnormal operation of the organism. In functionally defective tissues, programmed cell death (PCD) is one of the regulable fundamental mechanisms mediated by HSP90, including apoptosis, autophagy, necroptosis, ferroptosis, and others. Here, we show the complex relationship between HSP90 and different types of PCD in various diseases, and discuss the possibility of HSP90 as the common regulatory nodal in multiple PCD, which would provide a new perspective for the therapeutic approaches in disease.

Necroptosis: A Pathogenic Negotiator in Human Diseases

Over the past few decades, mechanisms of programmed cell death have attracted the scientific community because they are involved in diverse human diseases. Initially, apoptosis was considered as a crucial mechanistic pathway for programmed cell death; recently, an alternative regulated mode of cell death was identified, mimicking the features of both apoptosis and necrosis. Several lines of evidence have revealed that dysregulation of necroptosis leads to pathological diseases such as cancer, cardiovascular, lung, renal, hepatic, neurodegenerative, and inflammatory diseases. Regulated forms of necrosis are executed by death receptor ligands through the activation of receptor-interacting protein kinase (RIPK)-1/3 and mixed-lineage kinase domain-like (MLKL), resulting in the formation of a necrosome complex. Many papers based on genetic and pharmacological studies have shown that RIPKs and MLKL are the key regulatory effectors during the progression of multiple pathological diseases. This review focused on illuminating the mechanisms underlying necroptosis, the functions of necroptosis-associated proteins, and their influences on disease progression. We also discuss numerous natural and chemical compounds and novel targeted therapies that elicit beneficial roles of necroptotic cell death in malignant cells to bypass apoptosis and drug resistance and to provide suggestions for further research in this field.

The Role of Protein S-Nitrosylation in Protein Misfolding-Associated Diseases

Abnormal and excessive nitrosative stress contributes to neurodegenerative disease associated with the production of pathological levels of misfolded proteins. The accumulated findings strongly suggest that excessive NO production can induce and deepen these pathological processes, particularly by the S-nitrosylation of target proteins. Therefore, the relationship between S-nitrosylated proteins and the accumulation of misfolded proteins was reviewed. We particularly focused on the S-nitrosylation of E3-ubiquitin-protein ligase, parkin, and endoplasmic reticulum chaperone, PDI, which contribute to the accumulation of misfolded proteins. In addition to the target proteins being S-nitrosylated, NOS, which produces NO, and GSNOR, which inhibits S-nitrosylation, were also suggested as potential therapeutic targets for protein misfolding-associated diseases.

Bacteria as a treasure house of secondary metabolites with anticancer potential

Cancer stands in the frontline among leading killers worldwide and the annual mortality rate is expected to reach 16.4 million by 2040. Humans suffer from about 200 different types of cancers and many of them have a small number of approved therapeutic agents. Moreover, several types of major cancers are diagnosed at advanced stages as a result of which the existing therapies have limited efficacy against them and contribute to a dismal prognosis. Therefore, it is essential to develop novel potent anticancer agents to counteract cancer-driven lethality. Natural sources such as bacteria, plants, fungi, and marine microorganisms have been serving as an inexhaustible source of anticancer agents. Notably, over 13,000 natural compounds endowed with different pharmacological properties have been isolated from different bacterial sources. In the present article, we have discussed about the importance of natural products, with special emphasis on bacterial metabolites for cancer therapy. Subsequently, we have comprehensively discussed the various sources, mechanisms of action, toxicity issues, and off-target effects of clinically used anticancer drugs (such as actinomycin D, bleomycin, carfilzomib, doxorubicin, ixabepilone, mitomycin C, pentostatin, rapalogs, and romidepsin) that have been derived from different bacteria. Furthermore, we have also discussed some of the major secondary metabolites (antimycins, chartreusin, elsamicins, geldanamycin, monensin, plicamycin, prodigiosin, rebeccamycin, salinomycin, and salinosporamide) that are currently in the clinical trials or which have demonstrated potent anticancer activity in preclinical models. Besides, we have elaborated on the application of metagenomics in drug discovery and briefly described about anticancer agents (bryostatin 1 and ET-743) identified through the metagenomics approach.

The potential role of necroptosis in clinical diseases (Review)

As an important type of programmed cell death in addition to apoptosis, necroptosis occurs in a variety of pathophysiological processes, including infections, liver diseases, kidney injury, neurodegenerative diseases, cardiovascular diseases, and human tumors. It can be triggered by a variety of factors, such as tumor necrosis factor receptor and Toll‑like receptor families, intracellular DNA and RNA sensors, and interferon, and is mainly mediated by receptor‑interacting protein kinase 1 (RIP1), RIP3, and mixed lineage kinase domain‑like protein. A better understanding of the mechanism of necroptosis may be useful in the development of novel drugs for necroptosis‑related diseases. In this review, the focus is on the molecular mechanisms of necroptosis, exploring the role of necroptosis in different pathologies, discussing their potential as a novel therapeutic target for disease therapy, and providing suggestions for further study in this area.

Patterns of cell death induced by metformin in human MCF-7 breast cancer cells

The ability to evade apoptosis is an important mechanism of drug resistance and tumor progression in breast cancer. The induction of different pathways of cell death could be an important strategy to limit tumor progression. Metformin, a drug used to treat type two diabetes, has demonstrated promising results in breast cancer experiments. However, little is known about the patterns of cell death induced by this drug. We analyzed the involvement of apoptosis, necroptosis and ferroptosis in the toxicity of metformin in MCF-7 cells, evaluating proliferation, viability and oxidative stress. It was used different inhibitors of cell death: Z-VAD, a pan-caspase inhibitor that blocks apoptosis; Necrostatin-1, which inhibits RIPK1 activity and blocks necroptosis; and the iron chelator, deferoxamine, that chelates iron and prevents ferroptosis. The participation of oxidative stress was analyzed through the evaluation of total thiols, reduced glutathione (GSH) and malondialdehyde (MDA). Our results showed that metformin increased cell death, reduced proliferation, thiol and GSH and increased MDA in cells. After the association between metformin and Z-VAD or Necrostatin-1, the drug toxicity was abolished. Ferroptosis did not significantly enrolled in metformin action against MCF-7 cells. The preservation of cellular antioxidants was found in all situations that cell death was blocked. Together, these results reveals that metformin induces necroptosis and apoptosis in MCF-7 cells and oxidative stress generation play a role in these two pathways of cell death. This information could help future studies to improve strategies to breast cancer treatment.

Reblastatins Inhibit Phenotypic Changes of Monocytes/Macrophages in a Milieu Rich in 27-Hydroxycholesterol

We investigated effects of reblastatins on phenotypic changes in monocytes/macrophages induced by 27-hydroxycholesterol (27OHChol). Treatment of THP-1 monocytic cells with reblastatin derivatives, such as 17-demethoxy-reblastatin (17-DR), 18-dehydroxyl-17-demethoxyreblastatin (WK88-1), 18-hydroxyl-17-demethoxyreblastatin (WK88-2), and 18-hydroxyl-17-demethoxy-4,5-dehydroreblastatin (WK88-3), resulted in blockage of CCL2, CCL3, and CCL4 expression at the transcription and protein levels, which, in turn, impaired migration of monocytes/macrophages and Jurkat T cells expressing CCR5, and almost complete inhibition of transcription of M1 marker cytokines, like CXCL10, CXCL11, and TNF-α. Reblastatins also downregulated surface CD14 as well as soluble CD14 along with inhibition of LPS response and matrix metalloprotease-9 expression. Surface levels of mature dendritic cell (mDC)-specific markers, including CD80, CD83, CD88, CD197, and MHC class I and II molecules, were remarkably down-regulated, and 27OHChol-induced decrease of endocytic activity was recovered following treatment with 17-DR, WK88-1, WK88-2, and WK88-3. However, 15-hydroxyl-17-demethoxyreblastatin (DHQ3) did not affect the molecular or functional changes in monocytic cells induced by 27OHChol. Furthermore, surface levels of CD105, CD137, and CD166 were also down-regulated by 17-DR, WK88-1, WK88-2, and WK88-3, but not by DHQ3. Collectively, results of the current study indicate that, except DHQ3, reblastatins regulate the conversion and differentiation of monocytic cells to an immunostimulatory phenotype and mDCs, respectively, which suggests possible applications of reblastatins for immunomodulation in a milieu rich in oxygenated cholesterol molecules.

Current translational potential and underlying molecular mechanisms of necroptosis

Cell death has a fundamental impact on the evolution of degenerative disorders, autoimmune processes, inflammatory diseases, tumor formation and immune surveillance. Over the past couple of decades extensive studies have uncovered novel cell death pathways, which are independent of apoptosis. Among these is necroptosis, a tightly regulated, inflammatory form of cell death. Necroptosis contribute to the pathogenesis of many diseases and in this review, we will focus exclusively on necroptosis in humans. Necroptosis is considered a backup mechanism of apoptosis, but the in vivo appearance of necroptosis indicates that both caspase-mediated and caspase-independent mechanisms control necroptosis. Necroptosis is regulated on multiple levels, from the transcription, to the stability and posttranslational modifications of the necrosome components, to the availability of molecular interaction partners and the localization of receptor-interacting serine/threonine-protein kinase 1 (RIPK1), receptor-interacting serine/threonine-protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL). Accordingly, we classified the role of more than seventy molecules in necroptotic signaling based on consistent in vitro or in vivo evidence to understand the molecular background of necroptosis and to find opportunities where regulating the intensity and the modality of cell death could be exploited in clinical interventions. Necroptosis specific inhibitors are under development, but >20 drugs, already used in the treatment of various diseases, have the potential to regulate necroptosis. By listing necroptosis-modulated human diseases and cataloging the currently available drug-repertoire to modify necroptosis intensity, we hope to kick-start approaches with immediate translational potential. We also indicate where necroptosis regulating capacity should be considered in the current applications of these drugs.

Programmed necrosis and its role in management of breast cancer

Breast cancer is one of the major causes of cancer related deaths in women worldwide. A major factor responsible for treatment failure in breast cancer is the development of resistance to commonly used chemotherapeutic drugs leading to disease relapse. Several studies have shown dysregulation of molecular machinery of apoptosis, the major programmed cell death pathway in breast malignancies. Thus, there is an unmet need to search for an alternative cell death pathway which can work when apoptosis is compromised. Necroptosis or programmed necrosis is a relatively recently described entity which has attracted attention in this context. Classically, even in physiological conditions necroptosis is found to act if apoptosis is not functional due to some reason. Recently, more and more studies are being conducted in different malignancies to explore the possibility and utility of inducing cell death by necroptosis. The present review describes the key molecular players involved in necroptotic pathway and their status in breast cancer. In addition, the research done to utilize this pathway for treatment of breast cancer has also been highlighted.

Hydrogen Sulfide Gas Exposure Induces Necroptosis and Promotes Inflammation through the MAPK/NF-κB Pathway in Broiler Spleen

Hydrogen sulfide (H2S) is one of the main pollutants in the atmosphere, which is a serious threat to human health. The decomposition of sulfur-containing organics in chicken houses could produce a large amount of H2S, thereby damaging poultry health. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H2S gas (0-3 weeks: 4 ± 0.5 ppm, 4-6 weeks: 20 ± 0.5 ppm). The spleen samples were collected immediately after the chickens were euthanized at 2, 4, and 6 weeks. The histopathological and ultrastructural observations showed obvious necrosis characteristics of H2S-exposed spleens. H2S exposure suppressed GSH, CAT, T-AOC, and SOD activities; increased NO, H2O2, and MDA content and iNOS activity; and induced oxidative stress. ATPase activities and the expressions of energy metabolism-related genes were significantly decreased. Also, the expressions of related necroptosis (RIPK1, RIPK3, MLKL, TAK1, TAB2, and TAB3) were significantly increased, and the MAPK pathway was activated. Besides, H2S exposure activated the NF-κB classical pathway and induced TNF-α and IL-1β release. Taken together, we conclude that H2S exposure induces oxidative stress and energy metabolism dysfunction; evokes necroptosis; activates the MAPK pathway, eventually triggering the NF-κB pathway; and promotes inflammatory response in chicken spleens.

Towards natural mimetics of metformin and rapamycin

Aging is now at the forefront of major challenges faced globally, creating an immediate need for safe, widescale interventions to reduce the burden of chronic disease and extend human healthspan. Metformin and rapamycin are two FDA-approved mTOR inhibitors proposed for this purpose, exhibiting significant anti-cancer and anti-aging properties beyond their current clinical applications. However, each faces issues with approval for off-label, prophylactic use due to adverse effects. Here, we initiate an effort to identify nutraceuticals-safer, naturally-occurring compounds-that mimic the anti-aging effects of metformin and rapamycin without adverse effects. We applied several bioinformatic approaches and deep learning methods to the Library of Integrated Network-based Cellular Signatures (LINCS) dataset to map the gene- and pathway-level signatures of metformin and rapamycin and screen for matches among over 800 natural compounds. We then predicted the safety of each compound with an ensemble of deep neural network classifiers. The analysis revealed many novel candidate metformin and rapamycin mimetics, including allantoin and ginsenoside (metformin), epigallocatechin gallate and isoliquiritigenin (rapamycin), and withaferin A (both). Four relatively unexplored compounds also scored well with rapamycin. This work revealed promising candidates for future experimental validation while demonstrating the applications of powerful screening methods for this and similar endeavors.

Production of bone mineral material and BMP-2 in osteoblasts cultured on double acid-etched titanium

Background

The study of osteoblasts and their osteogenic functions is essential in order to understand them and their applications in implantology. In this sense, this study try to study BMP-2 production and bone matrix deposition, in addition to other biological variables, in osteoblasts cultured on a rough double acid-etched titanium surface (Osseotite®, Biomet 3i, Palm Beach Garden, Florida, USA) in comparison to a smooth titanium surface (machined) and a control Petri dish.

Material and Methods

An in vitro prospective study. NHOst human osteoblasts from the femur were cultured on three different surfaces: Control group: 25-mm methacrylate dish (n = 6); Machined group: titanium discs with machined surface (n = 6) and Experimental group: titanium discs with a double acid-etched nitric and hydrofluoric Osseotite® acid surface (n = 6). A quantification of the mitochondrial membrane potential, and studies of apoptosis, mobility and adhesion, bone productivity (BMP-2) and cellular bone synthesis were carried out after culturing the three groups for forty-eight hours.

Results

A statistically significant difference was observed in the production of BMP-2 between the experimental group and the other two groups (22.33% ± 11.06 vs. 13.10% ± 5.51 in the machined group and 3.88% ± 3.43 in the control group). Differences in cellular bone synthesis were also observed between the groups (28.34% ± 14.4% in the experimental group vs. 20.03% ± 6.79 in the machined group and 19.34% ± 15.93% in the control group).

Conclusions

In comparison with machined surfaces, Osseotite® surfaces favor BMP-2 production and bone synthesis as a result of the osteoblasts in contact with it.

Key words:BMP-2, Cytoskeleton, cell culture, bone matrix, apoptosis, cell viability.