Inhibitory Effects of Cathepsin K Inhibitor (ODN-MK-0822) on the Paracrine Pro-Osteoclast Factors of Breast Cancer Cells.

BACKGROUND: Breast cancer (BC) produces bone resorptive cytokines and growth factors that accelerate the development of osteoclasts (OCs), leading to osteolytic bone metastases. In the Long-term Odanacatib Fracture Trial (LOFT), the skeletal-metastasized breast cancer subjects who received odanacatib (ODN) had a delayed tumour progression and skeletal tumour burden as a result of anti-resorptive effects through inhibition of cathepsin K (CTSK). In this study, we explored the effect of ODN, a CTSK inhibitor, on the paracrine pro-osteoclast activity of breast cancer cells. METHODS: An immunohistochemistry study was performed to demonstrate CTSK and PTHrP expression in the samples of primary breast carcinoma. Expression of CTSK mRNA and protein was confirmed by the reverse transcription PCR and western blotting analysis in two human breast cancer cell lines, MDA-MB-231 and MCF-7 BC cell lines. Cells were incubated with sub-lethal amounts of ODN, and their conditioned supernatants were assessed for their capacity to differentiate PBMCs of healthy donors into osteoclast and its interference on bone-resorbing activities. We also measured the mRNA levels of major pro-osteoclast (pro-OC) factors in ODN-treated breast cancer cells and their secreted levels by semi-quantitative reverse transcription PCR and protein expression by immunoblotting. RESULTS: Different staining intensity was observed in samples containing PTHrP and CTSK in various histological grades of breast carcinoma. A significant positive relationship was found between CTSK expression and histological grade of BC and presence or absence of distant metastasis. The present study results also indicate that ODN has no effects on OCs number, however, ODN decreases the mRNA expression of secreted pro-OC factors such as PTHrP, CXCR-4, and TNF-α. Immunoblot indicates that ODN treatment decreased the protein expression of CTSK, IL-6, and IL-1ß, and thus lowered protein levels paralleled the defective phosphorylation of NF-κB. Moreover, there was a significant reduction in the level of growth factors such as IGF-1, PDGF, and TGFß expression at transcriptional level after ODN treatment as compared to control. CONCLUSION: ODN has shown to prevent osteolytic metastasis by interacting with the NF-κB pathway, inhibiting bone resorptive cytokines and growth factors. This effect can also be taken into account the delayed development of metastatic bone disease found in the long-term odanacatib fracture trial (LOFT) study.

Inhibitory effect of cathepsin K inhibitor (ODN-MK-0822) on invasion, migration and adhesion of human breast cancer cells in vitro.

Approximately 90% of patients with advanced breast cancer develop bone metastases; an event that results in severe decrease of quality of life and a drastic deterioration in prognosis. Therefore, to increase the survival of breast cancer patients, the development of new therapeutic strategies to impair metastatic process and skeletal complications is critical. Previous studies on the role of cathepsin K (CTSK) in metastatic spreading led to several strategies for inhibition of this molecule such as MIV-711 (Medivir), balicatib and odanacatib (ODN) which were on trial in the past. The present study intended to assess the anti-metastatic efficacy of ODN in breast cancer cells. Human breast cancer cell lines MDA-MB-231 were treated with different concentrations of ODN and performed invasion, adhesion and migration assays and, RT-PCR and western blot to evaluate the effect of ODN on the metastatic potential of breast cancer cells. ODN markedly decreased wound healing cell migration, invasion and adhesion at a dose dependent manner. ODN inhibits cell invasion by decreasing the matrix metalloproteinase (MMP-9) with the upregulation of TIMP-1 expression. ODN effectively inhibited the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal Kinase (JNK), and blocked the expression of ß-integrins and FAK proteins. ODN also significantly inhibited PI3K downstream targets Rac1, Cdc42, paxillin and Src which are critical for cell adhesion, migration and cytoskeletal reorganization. ODN exerts anti-metastatic action through inhibition of signaling pathway for MMP-9, PI3K and MAPK. This indicates potential therapeutic effects of ODN in the treatment of metastatic breast cancer.

The Citrus Flavanone Hesperetin Induces Apoptosis in CTCL Cells via STAT3/Notch1/NFκB-Mediated Signaling Axis.

BACKGROUND: Hesperetin is a natural compound known for its cholesterol-lowering effect and a wide range of pharmacological activities. OBJECTIVES: Investigating the potential anticancer activities of Hesperetin in malignant hematolymphoid cell lines HuT78 and MJ, derived from patients with Cutaneous T-Cell Lymphomas (CTCL). METHODS: The cytotoxic effect of Hesperetin on two different CTCL cell lines, HuT78 and MJ, was assessed by MTS-based colorimetric assay. Apoptosis, cell cycle, ROS (Reactive Oxygen Species) and molecular analysis were performed using flow-cytometry and immunoblotting. RESULTS: Hesperetin-treated CTCL cells were arrested at the sub-G1 phase of cell cycle with the concomitant decrease in the expression of the cell cycle regulator protein cyclin B. In addition, the study found that the cellular treatment with Hesperetin caused an induction of apoptosis, which was independent of ROS generation. Hesperetin caused a significant decrease in the expression level of anti-apoptotic protein Bcl-xL and an increase in cleaved caspase-3 and PARP proteins in CTCL cells. Furthermore, Hesperetin treatment in CTCL cells down-regulated the expression of Notch1 and phosphorylation of STAT3 (Tyr705) and inhibited NFκBp65. CONCLUSION: This study highlights the anticancer properties of Hesperetin. Which induces apoptosis in CTCL cells via STAT3/Notch1/NFκB mediated signaling pathway, suggesting that further development of this novel class of flavonoid may contribute to new drug discovery for certain hematolymphoid malignancies.

Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21WAF1/CIP1 and p27KIP1 in Cancer Cells.

BACKGROUND AND OBJECTIVE: Alterations in gene expressions are often due to epigenetic modifications that can have a significant influence on cancer development, growth, and progression. Lately, histone deacetylase inhibitors (HDACi) such as suberoylanilide hydroxamic acid (SAHA, or vorinostat, MK0683) have been emerging as a new class of drugs with promising therapeutic benefits in controlling cancer growth and metastasis. The small molecule RG7388 (idasanutlin, R05503781) is a newly developed inhibitor that is specific for an oncogene-derived protein called MDM2, which is also in clinical trials for the treatment of various types of cancers. These two drugs have shown the ability to induce p21 expression through distinct mechanisms in MCF-7 and LNCaP cells, which are reported to have wild-type TP53. Our understanding of the molecular mechanism whereby SAHA and RG7388 can induce cell cycle arrest and trigger cell death is still evolving. In this study, we performed experiments to measure the cell cycle arrest effects of SAHA and RG7388 using MCF-7 and LNCaP cells. MATERIALS AND METHODS: The cytotoxicity, cell cycle arrest, and apoptosis/necroptosis effects of the SAHA and RG7388 treatments were assessed using the Trypan Blue dye exclusion (TBDE) method, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence assay with DEVD-amc substrate, and immunoblotting methods. RESULTS: The RG7388 treatment was able to induce cell death by elevating p21WAF1/CIP1 through inhibition of MDM2 in LNCaP, but not in MCF-7 cells, even though there was evidence of p53 elevation. Hence, we suspect that there is some level of uncoupling of p53-mediated transcriptional induction of p21WAF1/CIP1 in MCF-7 cells. CONCLUSION: Our results from MCF-7 and LNCaP cells confirmed that SAHA and RG7388 treatments were able to induce cell death via a combination of cell cycle arrest and cytotoxic mechanisms. We speculate that our findings could lead to the development of newer treatments for breast and prostate cancers with drug combinations including HDACi.

Potential Biomolecules and Current Treatment Technologies for Diabetic Foot Ulcer: An Overview.

BACKGROUND: Diabetic foot ulceration remains a major challenge and is one of the most expensive and leading causes of major and minor amputations among patients with diabetic foot ulcer. Hence the purpose of this review is to emphasize on potential molecular markers involved in diabetic foot ulcer physiology, the efficacy of different types of dressing materials, adjunct therapy and newer therapeutic approach like nanoparticles for the treatment of diabetic foot ulcer. METHODS: We conducted a systematic literature review search by using Pubmed and other web searches. The quality evidence of diabetic foot ulcer biomolecules and treatments was collected, summarized and compared with other studies. RESULTS: The present investigation suggested that impaired wound healing in diabetic patients is an influence of several factors. All the advanced therapies and foot ulcer dressing materials are not suitable for all types of diabetic foot ulcers, however more prospective follow ups and in vivo and in vitro studies are needed to draw certain conclusion. Several critical wound biomolecules have been identified and are in need to be investigated in diabetic foot ulcers. The application of biocompatible nanoparticles holds a promising approach for designing dressing materials for the treatment of diabetic foot ulcer. CONCLUSION: Understanding the cellular and molecular events and identifying the appropriate treatment strategies for different foot ulcer grades will reduce recurrence of foot ulcer and lower limb amputation.

Platelet-rich fibrin/biphasic calcium phosphate impairs osteoclast differentiation and promotes apoptosis by the intrinsic mitochondrial pathway in chronic periodontitis.

BACKGROUND: The study explored the effect of platelet-rich fibrin/biphasic calcium phosphate (PRF/BCP) on differentiation and survival of osteoclasts obtained from peripheral blood of CP patients. METHODS: Peripheral blood mononuclear cells (PBMCs) from 25 patients with chronic periodontitis (CP) and 25 healthy individuals were assayed for cluster of differentiation14+ (CD14+ ) expression and monocytes were induced to differentiate into osteoclasts for 21 days in-vitro in the presence of macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kappa B ligand (RANKL). We assessed the number of osteoclasts by tartrate-acid resistant acid phosphatase (TRAP)-positivity. The mechanism of apoptosis was studied with reference to expression of Bcl-2, Bax, Bcl-xL, nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), caspase 3/9 and DNA fragmentation. RESULTS: We observed a relative increase in the proportion of circulating osteoclasts in test group than control group (healthy individuals). In addition, osteoclast precursors in untreated cells (CP) were more osteoclastogenic as compared to cells treated with PRF/BCP and hence, there was a significant increase in the number of osteoclasts in CP. In PRF/BCP treated cells, we found a direct inhibition of transcription factor NF-κB with an increased caspase 3/9 levels and caspase 3 activity. Additionally, the protein expression and transcriptional profile of Bax was upregulated and Bcl-2 and Bcl-xL levels were down-regulated on treatment with PRF/BCP. CONCLUSION: Our results revealed that the PRF/BCP displayed an inhibitory role in osteoclasts formation and its molecular mechanism of action was related to the apoptosis induction through intrinsic mitochondrial pathway.

Differential Mechanisms of Cell Death Induced by HDAC Inhibitor SAHA and MDM2 Inhibitor RG7388 in MCF-7 Cells.

Gene expression is often altered by epigenetic modifications that can significantly influence the growth ability and progression of cancers. SAHA (Suberoylanilide hydroxamic acid, also known as Vorinostat), a well-known Histone deacetylase (HDAC) inhibitor, can stop cancer growth and metastatic processes through epigenetic alterations. On the other hand, Letrozole is an aromatase inhibitor that can elicit strong anti-cancer effects on breast cancer through direct and indirect mechanisms. A newly developed inhibitor, RG7388 specific for an oncogene-derived protein called MDM2, is in clinical trials for the treatment of various cancers. In this paper, we performed assays to measure the effects of cell cycle arrest resulting from individual drug treatments or combination treatments with SAHA + letrozole and SAHA + RG7388, using the MCF-7 breast cancer cells. When SAHA was used individually, or in combination treatments with RG7388, a significant increase in the cytotoxic effect was obtained. Induction of cell cycle arrest by SAHA in cancer cells was evidenced by elevated p21 protein levels. In addition, SAHA treatment in MCF-7 cells showed significant up-regulation in phospho-RIP3 and MLKL levels. Our results confirmed that cell death caused by SAHA treatment was primarily through the induction of necroptosis. On the other hand, the RG7388 treatment was able to induce apoptosis by elevating BAX levels. It appears that, during combination treatments, with SAHA and RG7388, two parallel pathways might be induced simultaneously, that could lead to increased cancer cell death. SAHA appears to induce cell necroptosis in a p21-dependent manner, and RG7388 seems to induce apoptosis in a p21-independent manner, outlining differential mechanisms of cell death induction. However, further studies are needed to fully understand the intracellular mechanisms that are triggered by these two anti-cancer agents.

Selenium Influences Trace Elements Homeostasis, Cancer Biomarkers in Squamous Cell Carcinoma Patients Administered with Cancerocidal Radiotherapy

In the perspective of selenium as an antioxidant and anti-carcinogen, so far no strong intervention trials with selenium over radiation-treated oral squamous cell carcinoma cases have been conducted, to examine the response of the disease and the subsequent biochemical alterations. In the present study, untreated oral cancer cases (Gp II) were compared with radiation-treated groups with and without selenium (Gp IIa, IIb), forward to find the trace elements and cancer biomarkers status, at a follow-up of 6 months. Severe alteration in the trace elements levels of Se, Cu, Fe, Zn, Na, K, Ca, Cl, were noticed in Gp II. Though Gp IIa showed slight improvement, administration of selenium (Gp IIb) improved the level of all these elements to a greater extent (p<0.001). GpII and IIa showed increased level of bio markers 5'-nucleotidase, PschE, LAP, γ-GTP, LDH, SGOT, SGPT, ACP, ALP, CPK, TNF, CEA, AFP, Scc-Ag. The greater extent of restitution to near normalcy was observed in patients given selenium (Gp IIb) (p<0.001). Owing to the fact that selenium scavengers oxidants and hence decelerate carcinogenesis by eliminating tumors, so the tumor released constituents into the systemic circulation declined significantly. Therefore, the outcome of the study suggests selenium as a valuable therapeutic measure as adjuvant for oral cancer patients undergoing cancerocidal radiotherapy.

Inhibition of IKKß by celastrol and its analogues - an in silico and in vitro approach.

CONTEXT: Alzheimer's disease (AD) is the most common form of dementia affecting the aged population and neuroinflammation is one of the most observed AD pathologies. NF-κB is the central regulator of inflammation and inhibitor κB kinase (IKK) is the converging point in NF-κB activation. Celastrol is a natural triterpene used as a treatment for inflammatory conditions. OBJECTIVE: This study determines the neuroprotective and inhibitory effect of celastrol on amyloid beta1-42 (Aß1-42) induced cytotoxicity and IKKß activity, respectively. MATERIALS AND METHODS: Retinoic acid differentiated IMR-32 cells were treated with celastrol (1 µM) before treatment with Aß1-42 (IC30 10 µM) for 24 h. The cytotoxicity and IKK phosphorylation were measured by MTT and western blotting analysis, respectively. We screened 36 celastrol analogues for the IKKß inhibition by molecular docking and evaluated their drug like properties to delineate the neuroprotective effects. RESULTS: Celastrol (1 µM) inhibited Aß1-42 (10 µM) induced IκBα phosphorylation and protected IMR-32 cells from cell death. Celastrol and 25 analogues showed strong binding affinity with IKKß as evidenced by strong hydrogen-bonding interactions with critical active site residues. All the 25 analogues displayed strong anti-inflammatory properties but only 11 analogues showed drug-likeness. Collectively, molecule 15 has highest binding affinity, CNS activity and more drug likeness than parent compound celastrol. DISCUSSION AND CONCLUSION: The decreased expression of pIκBα in celastrol pretreated cells affirms the functional representation of inhibited IKKß activity in these cells. The neuroprotective potentials of celastrol and its analogues may be related to IKK inhibition.

Osteogenic potential of laser modified and conditioned titanium zirconium surfaces.

STATEMENT OF PROBLEM: The osseointegration of dental implant is related to their composition and surface treatment. Titanium zirconium (TiZr) has been introduced as an alternative to the commercially pure titanium and its alloys as dental implant material, which is attributed to its superior mechanical and biological properties. Surface treatments of TiZr have been introduced to enhance their osseointegration ability; however, reliable, easy to use surface modification technique has not been established. PURPOSE: The purpose of this study was to evaluate and compare the effect of neodymium-doped yttrium aluminum garnet (Nd-YAG) laser surface treatment of TiZr implant alloy on their osteogenic potential. MATERIALS AND METHODS: Twenty disc-shaped samples of 5 mm diameter and 2 mm height were milled from the TiZr alloy ingot. The polished discs were ultrasonically cleaned in distilled water. Ten samples each were randomly selected as Group A control samples and Group B consisted of Nd-YAG laser surface etched and conditioned test samples. These were evaluated for cellular response. Cellular adhesion and proliferation were quantified, and the results were statistically analyzed using nonparametric analysis. Cellular morphology was observed using electron and epiflurosence microscopy. RESULTS: Nd-YAG laser surface modified and conditioned TiZr samples increased the osteogenic potential. CONCLUSION: Nd-YAG laser surface modification of TiZr, improves the cellular activity, surface roughness, and wettability, thereby increasing the osteogenic potential.

Interferon ß improves the efficacy of low dose cisplatin by inhibiting NF-κB/p-Akt signaling on HeLa cells.

The purpose of this study was to evaluate the anticancer efficacy of interferon ß in combination with low dose of cisplatin on human cervical cancer progression, as well as its principal action mechanism. The combination treatment synergistically potentiated the effect of interferon ß on cell growth inhibition and DNA damage on HeLa cells by repressing NF-κB/p-Akt signaling. Synergistic targeting of these pathways has a therapeutic potential. Further, the combination treatment ameliorated the expression of pro-apoptotic Bax, and decreased the expression of anti-apoptotic protein Bcl-2. Additionally, the expression of active PARP was significantly increased and MMP-9 level was decreased in combination group as compared to the expression seen for the treatment with interferon ß or cisplatin alone. Results demonstrate that the synergistic inhibitory effects of interferon ß and low dose of cisplatin on human cervical cancer cells and also suggest that the inhibition of NF-κB/p-Akt signaling pathway plays a critical role in the anticancer effects of combination treatment along with the induction of PARP. Therefore, the combination of interferon ß and cisplatin may be a useful treatment for human cervical cancer, with a greater effectiveness than other treatments.

Inhibitory effects of interferon-ß on hepatocellular carcinoma HepG2 via Akt/STAT phosphorylation.

Conventional chemotherapy fails to cure metastatic hepatoma mainly due to its high hepatotoxicity. Currently, doxorubicin is the most widely used drug against liver cancer either as single agent or in combination with other chemotherapeutics such as cisplatin. It is limited due to their severe toxicity on normal hepatocytes. Therefore, alternative therapeutic agents without or with low hepatotoxicity are highly desirable. Interferons are a family of cytokines that potently demonstrate antiviral, immunomodulatory, and antiproliferative activities. It also exerts direct cytotoxic effects on tumor cells. The purpose of this study was to examine the in vitro cytotoxicity of interferon-ß on HepG2 cells. We revealed the presence of binding receptor of interferon-ß in HepG2 cells. The dose-dependent inhibition on cell proliferation was observed. We demonstrated that IFN-ß exhibited significant cytotoxicity in HepG2 cells mainly through phosphorylation of signal transducers and activators of transcription 2. The activation of Akt was suppressed. The stimulation of pro-apoptotic protein expression of Bax, inhibition of anti-apoptotic protein expression of Bcl-2, activation of cleaved caspases 9 and 3 was found at increasing concentrations. In conclusion, our results suggest that interferon-ß has potential to inhibit cell proliferation dose dependently. Increased concentrations of interferon-ß influenced apoptosis via mitochondrial pathway through inhibition of p-Akt.

Enzymatic and non-enzymatic antioxidant status in stage (III) human oral squamous cell carcinoma and treated with radical radio therapy: influence of selenium supplementation.

BACKGROUND: Oxidative stress is implicated in oral carcinogenesis and has been found to be aggravated during radiotherapy. A great deal of attention has been focused on the possible therapeutic implications of selenium as a potent antioxidant. We determined whether selenium supplementation to radiation treated oral cancer patients render improvement in the antioxidant status against oxidative stress. METHOD: Blood samples were collected from stage (III) oral cancer patients before initiating radiotherapy (Group B) (n=63) and this group is bifurcated into Group C-patients given radiotherapy alone (n=27) and Group D-patients given radiotherapy and supplemented with selenium (400 mug/day for 6 months) (n=36). Both Group C and D were followed up for 6 months. We evaluated the plasma selenium concentration, non-enzymatic system including GSH, vitamins E, C, A and ceruloplasmin and enzymatic antioxidant system including superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase. RESULTS: The concentrations of selenium, all non-enzymatic antioxidants and the activities of enzymatic antioxidants were found to be lowered in oral cancer patients (Group B), compared to normal (Group A) (p<0.05). Similar decrease in the concentration of selenium and antioxidants status was observed in radiotherapy group (Group C) (p<0.05). On the contrary, selenium group (Group D) showed marked increase in the concentrations of selenium and antioxidant status at 6 months compared to radiation group (Group C) (p<0.05). CONCLUSION: The observed result represents the antioxidant property of selenium through the improvement of antioxidant defense system. Selenium supplementation could be of great interest in protecting cells against oxidative stress.

Protein oxidative damage in arsenic induced rat brain: influence of DL-alpha-lipoic acid.

A body of evidence has accumulated implicating free radical generation and reaction of arsenic with protein thiols in the biochemical and molecular mechanisms of arsenic toxicity. Brain readily undergoes oxidative damage, so it is important to determine whether arsenic-induced changes in rat brain may be associated with oxidative events. An increase in oxidative stress may contribute to the development of protein damage in rat brain. Present experiments were performed to study the effect of arsenic (sodium arsenite, 100 ppm mixed in drinking water) on protein oxidation and further to demonstrate the potential of dl-alpha-lipoic acid (70 mg/kg body weight) against arsenic-induced changes in different anatomic regions (cortex, striatum, cerebellum, hypothalamus and hippocampus) of the brain of male Wistar rats. We report here that arsenic treated rats had a significantly higher level of oxidised protein as assessed by increased carbonyl residues and decreased protein thiols (protein sulfhydryls) as compared to control rats in all five regions studied, with the most notable changes occurring in the cortex, striatum and hippocampus. Coadministration of lipoic acid along with arsenic resulted in reversal of the arsenic induced trends in carbonyl and sulfhydryl concentrations. The results of the study showed, lipoic acid treatment reduces oxidative protein damage in arsenic intoxicated rat brain regions, which is associated with its antioxidant activity that combines free radical scavenging and metal chelating properties.