Simultaneous inhibition of the constitutively activated nuclear factor kappaB and of the interleukin-6 pathways is necessary and sufficient to completely overcome apoptosis resistance of human U266 myeloma cells

Molecular targets and mechanisms of anti-cancer effects of withanolides

Withanolides are a class of natural products with a steroidal lactone structure that exhibit a broad spectrum of anti-cancer effects. To date, several studies have shown that their possible mechanisms in cancer development and progression are associated with the regulation of cell proliferation, apoptosis, metastasis, and angiogenesis. Withanolides can also attenuate inflammatory responses, as well as modulate the genomic instability and energy metabolism of cancer cells. In addition, they may improve the safety and efficacy of cancer treatments as adjuvants to traditional cancer therapeutics. Herein, we summarize the molecular targets and mechanisms of withanolides in different cancers, as well as their current clinical studies on them.

Emerging hallmarks of endometriosis metabolism: A promising target for the treatment of endometriosis

Endometriosis, characterized by ectopic endometrium growth in the extrauterine environment, is one of the most notable diseases of the female reproductive system. Worldwide, endometriosis affects nearly 10 % of women in their reproductive years and causes a significant decline in quality of life. Despite extensive investigations of endometriosis over the past years, the mechanisms of endometriosis pathogenesis remain unclear. In recent years, metabolic factors have increasingly been considered factors in endometriosis. There is compelling evidence regarding the progress of endometriosis in the context of severe metabolic dysfunction. Hence, the curative strategies and ongoing attempts to conquer endometriosis might start with metabolic pathways. This review focuses on metabolic mechanisms and summarizes current research progress. These findings provide valuable information for the non-intrusive diagnosis of the disease and may contribute to the understanding of the pathogenesis of endometriosis.

Withaferin A: From Ancient Remedy to Potential Drug Candidate

Withaferin A (WA) is a pivotal withanolide that has conquered a conspicuous place in research, owning to its multidimensional biological properties. It is an abundant constituent in Withania somnifera Dunal. (Ashwagandha, WS) that is one of the prehistoric pivotal remedies in Ayurveda. This article reviews the literature about the pharmacological profile of WA with special emphasis on its anticancer aspect. We reviewed research publications concerning WA through four databases and provided a descriptive analysis of literature without statistical or qualitative analysis. WA has been found as an effective remedy with multifaceted mechanisms and a broad spectrum of pharmacological profiles. It has anticancer, anti-inflammatory, antiherpetic, antifibrotic, antiplatelet, profibrinolytic, immunosuppressive, antipigmentation, antileishmanial, and healing potentials. Evidence for wide pharmacological actions of WA has been established by both in vivo and in vitro studies. Further, the scientific literature accentuates the role of WA harboring a variable therapeutic spectrum for integrative cancer chemoprevention and cure. WA is a modern drug from traditional medicine that is necessary to be advanced to clinical trials for advocating its utility as a commercial drug.

Daturataturin A, a withanolide in Datura metel L., induces HaCaT autophagy through the PI3K-Akt-mTOR signaling pathway

Daturataturin A (DTA), a withanolide compound in Datura metel L., exhibits excellent anti-inflammatory and anti-proliferative activities. Here, we report the study of DTA-induced proliferation and inflammation in human immortalized keratinocytes (HaCaTs) and the associated molecular mechanisms. HaCaTs are a model of the epidermal proliferative state of cells. The pharmacodynamics and mechanism of DTA were studied by western blot, immunofluorescence, apoptosis and proliferation detection, and real-time quantitative polymerase chain reaction. We confirmed that DTA induced HaCaT autophagy, which, in turn, induced HaCaT senescence and, ultimately, led to cell cycle arrest. DTA also negatively regulated inflammation through the activation of autophagy. This may be one of the mechanisms underlying the action of Datura metel L. preparation used for the treatment of psoriasis.

Effect of levamisole on expression of CD138 and interleukin-6 in human multiple myeloma cell lines

INTRODUCTION

Multiple myeloma (MM) is a B-cell malignancy accounting for 0.8% of all cancer deaths globally. This malignancy is characterized by lytic bone disease renal insufficiency, anemia, hypercalcemia, and immunodeficiency. The myeloma cells have enhanced expression of CD138. CD138 is a transmembrane heparin sulfate glycoprotein expressed on different types of adherent and nonadherent cells.CD138 is used as a standard marker for identification of tumor cells.

AIMS AND OBJECTIVES

Despite introduction of many therapeutic agents, the management of multiple myeloma (MM) remains a challenge and search for new therapeutic agents is in progress. In this study, we attempted to evaluate the effect of an alkaline phosphatase inhibitor, levamisole on expression of CD138, and level of interleukin-6 (IL-6) in human MM cell lines RPMI 8226 and U266 B1.

MATERIAL AND METHODS

U266B1 and RPMI 8226 cell lines were obtained from the National Centre for Cell Sciences, Pune. Alkaline phosphatase assay, Interleukin-6 assay and CD138 expression on myeloma cells by flow cytometry were investigated when the cells were exposed to Levamisole.

RESULTS

Levamisole-mediated growth inhibition of myeloma cells in vitro is associated with a loss of CD138 and increased IL-6 secretion. The increased secretion of IL-6 by myeloma cells could be an attempt to protect themselves from apoptosis.

CONCLUSION

Levamisole inhibited CD138 expression and affected the levels of IL-6 in a dose-dependent manner. The results of the present study add new dimension to levamisole's mode of action as inhibitor of CD138 and IL-6 and as an antiapoptotic agent.

Proteomic characterization of Withaferin A-targeted protein networks for the treatment of monoclonal myeloma gammopathies

Withaferin A (WA), a natural steroid lactone from the plant Withania somnifera, is often studied because of its antitumor properties. Although many in vitro and in vivo studies have been performed, the identification of Withaferin A protein targets and its mechanism of antitumor action remain incomplete. We used quantitative chemoproteomics and differential protein expression analysis to characterize the WA antitumor effects on a multiple myeloma cell model. Identified relevant targets were further validated by Ingenuity Pathway Analysis and Western blot and indicate that WA targets protein networks that are specific for monoclonal gammopathy of undetermined significance (MGUS) and other closely related disorders, such as multiple myeloma (MM) and Waldenström macroglobulinemia (WM). By blocking the PSMB10 proteasome subunit, downregulation of ANXA4, potential association with HDAC6 and upregulation of HMOX1, WA puts a massive blockage on both proteotoxic and oxidative stress responses pathways, leaving cancer cells defenseless against WA induced stresses. These results indicate that WA mediated apoptosis is preceded by simultaneous targeting of cellular stress response pathways like proteasome degradation, autophagy and unfolded protein stress response and thus suggests that WA can be used as an effective treatment for MGUS and other closely related disorders.

SIGNIFICANCE

Multifunctional antitumor compounds are of great potential since they reduce the risk of multidrug resistance in chemotherapy. Unfortunately, characterization of all protein targets of a multifunctional compound is lacking. Therefore, we optimized an SILAC quantitative chemoproteomics workflow to identify the potential protein targets of Withaferin A (WA), a natural multifunctional compound with promising antitumor properties. To further understand the antitumor mechanisms of WA, we performed a differential protein expression analysis and combined the altered expression data with chemoproteome WA target data in the highly curated Ingenuity Pathway database. We provide a first global overview on how WA kills multiple myeloma cancer cells and serve as a starting point for further in depth experiments. Furthermore, the combined approach can be used for other types of cancer and/or other promising multifunctional compounds, thereby increasing the potential development of new antitumor therapies.

Withaferin A induces cell death and differentiation in multiple myeloma cancer stem cells

Multiple myeloma (MM) remains an incurable malignancy despite the development of novel therapeutics. This is believed to be due to a subset of rare chemotherapy-resistant cancer stem cells (CSCs). Differentiation therapy represents one strategy aimed at reducing the stemness of CSCs. The anticancer effect of withaferin A (WFA) was studied in MM-CSCs and RPMI 8226 MM tumoral plasma cells (RPMIs). WFA exhibited growth inhibitory effects in both MM-CSCs and RPMIs, with IC₅₀ values of 649 and 224 nM, respectively. WFA also induced a G₂ cell cycle arrest, as well as cell death and apoptosis. Although, WFA did not exhibit a direct anti-migratory effect, a remarkable morphological change was observed in MM-CSCs in response to WFA treatment. Using qPCR gene expression analyses, WFA caused a reduction in stemness markers, and a promotion of differentiation markers in MM-CSCs. These results warrant further investigation of WFA in relevant MM animal models.

Selective glucocorticoid receptor-activating adjuvant therapy in cancer treatments

Although adverse effects and glucocorticoid resistance cripple their chronic use, glucocorticoids form the mainstay therapy for acute and chronic inflammatory disorders, and play an important role in treatment protocols of both lymphoid malignancies and as adjuvant to stimulate therapy tolerability in various solid tumors. Glucocorticoid binding to their designate glucocorticoid receptor (GR), sets off a plethora of cell-specific events including therapeutically desirable effects, such as cell death, as well as undesirable effects, including chemotherapy resistance, systemic side effects and glucocorticoid resistance. In this context, selective GR agonists and modulators (SEGRAMs) with a more restricted GR activity profile have been developed, holding promise for further clinical development in anti-inflammatory and potentially in cancer therapies. Thus far, the research into the prospective benefits of selective GR modulators in cancer therapy limped behind. Our review discusses how selective GR agonists and modulators could improve the therapy regimens for lymphoid malignancies, prostate or breast cancer. We summarize our current knowledge and look forward to where the field should move to in the future. Altogether, our review clarifies novel therapeutic perspectives in cancer modulation via selective GR targeting.

Ex-vivo characterization of circulating colon cancer cells distinguished in stem and differentiated subset provides useful biomarker for personalized metastatic risk assessment

BACKGROUND

Circulating tumor cells (CTCs) represent one of the most interesting target in improving diagnosis, prognosis and treatment. Herein we evaluate the possibility of using an emo-cytometric approach on the evaluation of the heterogeneous population of CTCs to improve personalized metastatic risk assessment. We benchmarked ex vivo behavior of distinct subsets of circulating colon tumor cells with correspondent clinical behavior of patients from which we isolated CTCs.

METHODS

Isolation and CTC expansion were performed by a gradient protocol. In vitro characterization was determined by flow cytometry, immunofluorescence, western blotting and proteomic profiling. Cell sorter was performed with immunomagnetic beads. Confocal microscopy was used to evaluate tissue sections. Kaplan Mayer curves was cared for through Medcalc program.

RESULTS

We collected heterogeneous CTCs, derived from the whole blood of seven patients affected by colon cancer, expressing CD133(pos)CD45(neg) (5 ± 1) and (2 ± 1) and CK20(pos)CD45(neg) of (29 ± 3) (11 ± 1) cells/ml in Dukes D and A stage respectively. Proliferation rate of 57 ± 16 %, expression for CXCR4(pos) of 18 ± 7 % and detectable levels of IL-6, IL-8 and SDF-1 cytokines in conditioned culture medium characterized short-time expanded-CTCs (eCTCs). ECTCs organized in tumor sphere were CD45(neg)CD133(pos) while in adhesion were CXCR4(pos)CK20(pos). These two subsets were separately injected in mice. The first group of xenografts developed superficial lesions within 2 weeks. In the second group, in absence of growing tumour, the survival of injected eCTCs was monitored through SDF-1 serum levels detection. The detection of human cancer cells expressing CK20, in mice tissues sections, suggested a different biological behaviour of injected eCTC-subsets: tumorigenic for the first and disseminating for the second. The benchmarking of the experimental data with the clinical course highlights that patients with prevalence of circulating cancer stem cells (CD45(neg)CD133(pos)) have a lower overall survival. Conversely, patients with prevalence of circulating differentiated cells (CXCR4(pos)CK20(pos)) have a low disease-free survival.

CONCLUSION

On the basis of the heterogeneous composition and despite the low number of CTCs, it was possible to distinguish two subgroups of CTCs, suggesting a different clinical outcome. CTC-subsets detailing is useful to better define the metastatic-risk personalized score thus improving disease management and reducing patient care cost.

Drugs acting on homeostasis: challenging cancer cell adaptation

Cancer treatment aims to exploit properties that define malignant cells. In recent years, it has become apparent that malignant cells often survive cancer treatment and ensuing cell stress by switching on auxiliary turnover pathways, changing cellular metabolism and, concomitantly, the gene expression profile. The changed profile impacts the material exchange of cancer cells with affected tissues. Herein, we show that pathways of proteostasis and energy generation regulate common transcription factors. Namely, when one pathway of intracellular turnover is blocked, it triggers alternative turnover mechanisms, which induce transcription factor proteins that control expression of cytokines and regulators of apoptosis, cell division, differentiation, metabolism, and response to hormones. We focus on several alternative turnover mechanisms that can be blocked by drugs already used in clinical practice for the treatment of other non-cancer related diseases. We also discuss paradigms on the challenges posed by cancer cell adaptation mechanisms.

Potential Anticancer Properties and Mechanisms of Action of Withanolides

Plant-based Ayurvedic medicine has been practiced in India for thousands of years for the treatment of a variety of disorders. They are rich sources of bioactive compounds potentially useful for prevention and treatment of cancer. Withania somnifera (commonly known as Ashwagandha in Ayurvedic medicine) is a widely used medicinal plant whose anticancer value was recognized after isolation of steroidal compounds withanolides from the leaves of this shrub. Withaferin A is the first member of withanolides to be isolated, and it is the most abundant withanolide present in W. somnifera. Its cancer-protective role has now been established using chemically induced and oncogene-driven rodent cancer models. The present review summarizes the key preclinical studies demonstrating anticancer effects of withaferin along with its molecular targets and mechanisms related to its anticancer effects. Anticancer potential of other withanolides is also discussed.

Soluble CD54 induces human endothelial cells ex vivo expansion useful for cardiovascular regeneration and tissue engineering application

Aim

Consistent expansion of primary human endothelial cells in vitro is critical in the development of engineered tissue. A variety of complex culture media and techniques developed from different basal media have been reported with alternate success. Incongruous results are further confounded by donor-to-donor variability and cellular source of derivation. Our results demonstrate how to overcome these limitations using soluble CD54 (sCD54) as additive to conventional culture medium.

Methods and results

Isolated primary fragment of different vessel types was expanded in Ham's F12 DMEM, enriched with growth factors, Fetal Calf Serum and conditioned medium of Human Umbilical Vein Endothelial Cells (HUVEC) collected at different passages. Cytokine content of culture media was analyzed in order to identify the soluble factors correlating with better proliferation profile. sCD54 was found to induce the in vitro expansion of human endothelial cells (HECs) independently from the vessels source and even in the absence of HUVEC-conditioned medium. The HECs cultivated in the presence of sCD54 (50 ng/ml), resulted positive for the expression of CD146 and negative for CD45, and lower fibroblast contamination. Cells were capable to proliferate with an S phase of 25%, to produce vascular endothelial growth factor, VEGF, (10 ng/ml) and to give origin to vessel-like tubule in vitro.

Conclusion

Our results demonstrate that sCD54 is an essential factor for the in-vitro expansion of HECs without donor and vessel-source variability. Resulting primary cultures can be useful, for tissue engineering in regenerative medicine (e.g. artificial micro tissue generation, coating artificial heart valve etc.) and bio-nanotechnology applications.

Withaferin A Inhibits STAT3 and Induces Tumor Cell Death in Neuroblastoma and Multiple Myeloma

Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor that has been implicated in many human cancers and has emerged as an ideal target for cancer therapy. Withaferin A (WFA) is a natural product with promising antiproliferative properties through its association with a number of molecular targets including STAT3. However, the effect of WFA in pediatric neuroblastoma (NB) and its interaction with STAT3 have not been reported. In this study, we found that WFA effectively induces dose-dependent cell death in high-risk and drug-resistant NB as well as multiple myeloma (MM) tumor cells, prevented interleukin-6 (IL-6)–mediated and persistently activated STAT3 phosphorylation at Y705, and blocked the transcriptional activity of STAT3. We further provide computational models that show that WFA binds STAT3 near the Y705 phospho-tyrosine residue of the STAT3 Src homology 2 (SH2) domain, suggesting that WFA prevents STAT3 dimer formation similar to BP-1-102, a well-established STAT3 inhibitor. Our findings propose that the antitumor activity of WFA is mediated at least in part through inhibition of STAT3 and provide a rationale for further drug development and clinical use in NB and MM.

Establishment and characterization of bortezomib-resistant U266 cell line: constitutive activation of NF-κB-mediated cell signals and/or alterations of ubiquitylation-related genes reduce bortezomib-induced apoptosis

Bortezomib has been known as the most promising anti-cancer drug for multiple myeloma (MM). However, recent studies reported that not all MM patients respond to bortezomib. To overcome such a stumbling-block, studies are needed to clarify the mechanisms of bortezomib resistance. In this study, we established a bortezomib-resistant cell line (U266/velR), and explored its biological characteristics. The U266/velR showed reduced sensitivity to bortezomib, and also showed crossresistance to the chemically unrelated drug thalidomide. U266/velR cells had a higher proportion of CD138 negative subpopulation, known as stem-like feature, compared to parental U266 cells. U266/velR showed relatively less inhibitory effect of prosurvival NF-κB signaling by bortezomib. Further analysis of RNA microarray identified genes related to ubiquitination that were differentially regulated in U266/velR. Moreover, the expression level of CD52 in U266 cells was associated with bortezomib response. Our findings provide the basis for developing therapeutic strategies in bortezomib-resistant relapsed and refractory MM patients.

Preclinical validation of interleukin 6 as a therapeutic target in multiple myeloma

Studies on the biologic and molecular genetic underpinnings of multiple myeloma (MM) have identified the pleiotropic, pro-inflammatory cytokine, interleukin-6 (IL-6), as a factor crucial to the growth, proliferation and survival of myeloma cells. IL-6 is also a potent stimulator of osteoclastogenesis and a sculptor of the tumor microenvironment in the bone marrow of patients with myeloma. This knowledge has engendered considerable interest in targeting IL-6 for therapeutic purposes, using a variety of antibody- and small-molecule-based therapies. However, despite the early recognition of the importance of IL-6 for myeloma and the steady progress in our knowledge of IL-6 in normal and malignant development of plasma cells, additional efforts will be required to translate the promise of IL-6 as a target for new myeloma therapies into significant clinical benefits for patients with myeloma. This review summarizes published research on the role of IL-6 in myeloma development and describes ongoing efforts by the University of Iowa Myeloma Multidisciplinary Oncology Group to develop new approaches to the design and testing of IL-6-targeted therapies and preventions of MM.

Sequential treatment of HPV E6 and E7-expressing TC-1 cells with bortezomib and celecoxib promotes apoptosis through p-p38 MAPK-mediated downregulation of cyclin D1 and CDK2

Interruption of the cell cycle is accompanied by changes in several related molecules that result in the activation of apoptosis. The present study was performed to verify the apoptotic effects of sequential treatment with bortezomib and celecoxib in TC-1 cells expressing the human papillomavirus (HPV) E6 and E7 proteins. In TC-1 cells sequentially treated with bortezomib and celecoxib, apoptosis was induced through decreased expression of signal transducer and activator of transcription-3 (STAT3), cyclin D1 and cyclin-dependent kinase (CDK) 2, which are major regulators of the G0/G1 cell cycle checkpoint. In addition, increased levels of p21, CHOP, BiP and p-p38 MAPK were identified in these cells. The treatment-induced apoptosis was effectively inhibited by treatment with SB203580, an inhibitor of p-p38. Moreover, the growth of tumors sequentially treated with bortezomib and celecoxib was retarded compared to the growth of tumors exposed to a single treatment with either bortezomib or celecoxib in vivo. We demonstrated that sequential treatment with bortezomib and celecoxib induced apoptosis via p-p38-mediated G0/G1 cell cycle arrest and endoplasmic reticulum (ER) stress. Sequential treatment with these two drugs could therefore be a useful therapy for cervical cancer.

Myeloid-derived suppressor cell function is reduced by Withaferin A, a potent and abundant component of Withania somnifera root extract

Myeloid cells play a crucial role in tumor progression. The most common tumor-infiltrating myeloid cells are myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAMs). These cells promote tumor growth by their inherent immune suppressive activity which is enhanced by their cross-talk. The root extract of the plant Withania somnifera (Ashwagandha) (WRE) has been reported to reduce tumor growth. HPLC analysis identified Withaferin A (WA) as the most abundant constituent of WRE and led us to determine whether the anti-tumor effects of WRE and WA involve modulating MDSC and TAM activity. A prominent effect of MDSC is their production of IL-10 which increases upon cross-talk with macrophages, thus polarizing immunity to a pro-tumor type 2 phenotype. In vitro treatment with WA decreased MDSC production of IL-10 and prevented additional MDSC production of IL-10 generated by MDSC-macrophage cross-talk. Macrophage secretion of IL-6 and TNFα, cytokines that increase MDSC accumulation and function, was also reduced by in vitro treatment with WA. Much of the T-cell suppressive activity of MDSC is due to MDSC production of reactive oxygen species (ROS), and WA significantly reduced MDSC production of ROS through a STAT3-dependent mechanism. In vivo treatment of tumor-bearing mice with WA decreased tumor weight, reduced the quantity of granulocytic MDSC, and reduced the ability of MDSC to suppress antigen-driven activation of CD4+ and CD8+ T cells. Thus, adjunctive treatment with WA reduced myeloid cell-mediated immune suppression, polarized immunity toward a tumor-rejecting type 1 phenotype, and may facilitate the development of anti-tumor immunity.

The effects of nonsteroidal anti-inflammatory drugs on clinical outcomes, synovial fluid cytokine concentration and signal transduction pathways in knee osteoarthritis. A randomized open label trial

OBJECTIVE

We investigated the effects of celecoxib, diclofenac, and ibuprofen on the disease-specific quality of life, synovial fluid cytokines and signal transduction pathways in symptomatic knee osteoarthritis (OA).

DESIGN

Ninety patients scheduled for a total knee arthroplasty (TKA) were randomized to six groups that were treated with low and high dosages of celecoxib, diclofenac or ibuprofen. At the time of the first admission (T0) and at surgery (T1 = 14 days after beginning of the nonsteroidal anti-inflammatory drugs (NSAIDs)), samples of knee synovial fluid were obtained from each patient for analysis. During the surgery the synovial tissue was harvested from the knee of patients. The Western Ontario and McMaster universities (WOMAC) score was used to evaluate the patient disease-specific quality of life at T0 and T1. Microarray tests performed at T0 and T1 were used to evaluate the effects of NSAIDs on Tumor necrosis factor (TNF)-alpha, Interleukin-6 (IL-6), IL8 and Vascular endothelial growth factor (VEGF) concentration in the synovial fluid. Western blot assays evaluated the effects of NSAIDs on MAP kinase (MAPK) signal transduction pathway in the synovial membrane.

RESULTS

NSAID treatment induced a statistically significant improvement in the WOMAC score and a statistically significant decrease in the IL-6, VEGF and TNF-alpha concentration in the synovial fluid. Higher dosages of NSAIDs provided a greater improvement in the disease-specific quality of life of patients and lower concentrations of pro-inflammatory cytokines in the synovial fluid. Inhibition of MAPKs was noted after NSAID treatment.

CONCLUSION

Short-term NSAID treatment improves the patient disease-specific quality of life with a parallel decrease in pro-inflammatory synovial fluid cytokine levels in knee OA. Signal transduction pathways may be involved in regulating the anti-inflammatory effects of NSAIDs. ClinicalTrial.gov: NCT01860833.

Effects of simvastatin and rosuvastatin on RAS protein, matrix metalloproteinases and NF-κB in lung cancer and in normal pulmonary tissues

OBJECTIVES

In this study, we have evaluated effects of 24-hour treatments with simvastatin or rosuvastatin on RAS protein, NF-κB and MMP expression in LC tissues obtained from 12 patients undergoing thoracic surgery.

MATERIALS AND METHODS

Normal and lung tumour tissues obtained from each sample were exposed to simvastatin (2.5-30 μm) or rosuvastatin (1.25-30 μm) and western blot analysis was then performed.

RESULTS

We documented increased expression of proteins, MMP-2, MMP-9 and NF-κB-p65 in LC tissues, with respect to normal tissues (P < 0.01). In the malignant tissues, simvastatin and rosuvastatin significantly (P < 0.01) and dose-dependently reduced RAS protein, MMP-2/9 and NF-κB-p65 expression.

CONCLUSIONS

In conclusion, our results suggest that simvastatin and rosuvastatin could play a role in LC treatment by modulation of RAS protein, MMP-2/9 and NF-κB-p65.

Doxycycline speeds up healing of chronic venous ulcers

Venous ulcers are common, with an overall prevalence of up to 2% in the general population of western countries, and have significant socioeconomic impact. Matrix metalloproteinases (MMPs) are involved in the alteration of extracellular matrix that could lead to venous ulceration. Sixty-four patients with venous ulcers were recruited in a 22-month period. All patients were subjected to the most appropriate treatment considering also the patient's wishes (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 32 persons in each (groups A and B). Patients of group A in addition to the basic treatment, described above, received the administration of oral low doses of doxycycline 20 mg b.i.d. for 3 months, whereas patients of group B received basic treatment only. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a higher healing rate compared with group B. In group B, the lower healing rate was related to higher levels of MMP-9; neutrophil gelatinase-associated lipocalin and vascular endothelial growth factor, documented in plasma; wound fluid and biopsies executed and compared between both groups. Pharmacological treatments, as doxycycline administration, which by means of its immunomodulatory and anti-inflammatory actions, through the inhibition of MMP, could improve extracellular matrix functioning and represent a possible solution to support wound healing.

Chronic venous leg ulcers are associated with high levels of metalloproteinases-9 and neutrophil gelatinase-associated lipocalin

Venous ulcers are related to dysfunctions in extracellular matrix. Both matrix metalloproteinases (MMP) and neutrophil gelatinase-associated lipocalin (NGAL) could play a role in the healing process in patients with chronic venous ulcers. We evaluated the role of MMP-9 and NGAL in the healing process in venous ulceration. We performed an open-label, parallel groups, single clinical center study. Patients with chronic venous leg ulcers represented the test group (Group I), whereas patients without chronic ulcers represented the control group (Group II). In Group I plasma and wound fluid samples were collected at the time of admission, at the time of the surgery, and at the follow-up, while ulcer tissues were taken at the time of the surgery. In Group II, plasma and wound fluid were collected at admission and at the time of the surgery, whereas skin tissues were collected at the time of the surgery. Enzyme-linked immunosorbent assay test was used to evaluate the levels of MMP-9 and NGAL in plasma and wound fluid, whereas Western blot analysis was performed to estimate the expression of MMP-9 and NGAL in tissues. Enzyme-linked immunosorbent assay tests revealed significantly higher levels of MMP-9 and NGAL in both plasma and wound fluid of patients with ulcers compared to patients without ulcers (p < 0.01). Moreover, Western blot analysis documented an increased expression of MMP-9 and NGAL in biopsy tissue of patients with ulcers compared to patients without ulcers (p < 0.01). In conclusion MMP-9 and NGAL may correlate with the clinical course of venous ulcers.

Bortezomib enhances antigen-specific cytotoxic T cell responses against immune-resistant cancer cells generated by STAT3-ablated dendritic cells

Dendritic cell (DC)-based vaccines have received attention as a new therapeutic modality against cancer. However, increased STAT3 activity in the tumor microenvironment makes DCs tolerogenic and suppresses their antitumor activity. In this study, we explored the effects of a combination treatment consisting of a proteasome inhibitor, bortezomib, and an antigen specific STAT3-ablated (STAT3⁻/⁻) DC-based vaccine on the control of TC-1(P3) tumors, a p53-degraded immune resistant cancer cells. We found that E7-antigen expressing STAT3⁻/⁻ DC (E7-DC-1STAT3⁻/⁻) vaccination enhanced generation of E7-specific CD8⁺ T cells, but was not enough to control TC-1(P3) cancer cells. Therefore, we investigated whether bortezomib could create a synergistic effect with E7-DC-1STAT3⁻/⁻ vaccination. We found that apoptosis via down-regulation of STAT3 and NF-κB and up-regulation of Fas and death receptor 5 (DR5) expression in TC-1(P3) induced by bortezomib was independent of p53 status. We also observed that TC-1(P3) cells pretreated with bortezomib had markedly enhanced anti-tumor effects on E7-specific CD8⁺ T cells through a Fas/DR5-mediated mechanism. In addition, TC-1(P3) tumor-bearing mice treated with bortezomib prior to vaccination with E7-DC-1STAT3⁻/⁻ demonstrated enhanced generation of E7-specific CD8⁺ T cells and prolonged survival compared to those treated with monotherapy. These results suggest that the anti-tumor effects against a p53-degraded immune resistant variant generated by antigen-expressing STAT3-ablated mature DCs may be enhanced by bortezomib via death receptor-mediated apoptosis.

The nuclear factor kappa-B signaling pathway as a therapeutic target against thyroid cancers

BACKGROUND

The nuclear factor kappa-B (NF-κB) proteins, a family of transcription factors found virtually in all cells, are known to play crucial roles in the growth of a number of human malignancies. The ability of NF-κB to target a large number of genes that regulate cell proliferation, differentiation, survival, and apoptosis, provides clues toward its deregulation during the process of tumorigenesis, metastatic progression, and therapeutic resistance of tumors.

SUMMARY

In addition to the signaling pathways known to be involved in thyroid tumorigenesis, such as the mitogen-activated protein kinase and janus kinase cascades, studies implicate the NF-κB pathway in the development of both less aggressive thyroid cancers, papillary and follicular adenocarcinomas, and progression to aggressive thyroid cancers, such as anaplastic adenocarcinomas. A constitutively activated NF-κB pathway also closely links Hashimoto's thyroiditis with increased incidence of thyroid cancers. The NF-κB pathway is becoming one of the major targets for drug development, and a number of compounds have been developed to inhibit this pathway at different levels in cancer cells. Some of these targets have shown promising outcomes in both in vitro and in vivo investigations and a handful of them have shown efficacy in the clinical setting.

CONCLUSIONS

This review discusses the recent findings that demonstrate that the inhibition of NF-κB, alone or with other signaling pathway inhibitors may be of significant therapeutic benefits against aggressive thyroid cancers.

Molecular insight in the multifunctional activities of Withaferin A

Herbal medicine which involves the use of plants for their medicinal value, dates as far back as the origin of mankind and demonstrates an array of applications including cardiovascular protection and anti-cancer activities, via antioxidant, anti-inflammatory and metabolic activities. Even today the popularity of medicinal herbs is still growing like in traditional medicines such as the Indian medicine, Ayurveda. One of the Ayurvedic medicinal plants is Withania somnifera Dunal, of which the important constituents are the withanolides. Among them, Withaferin A is one of the most bioactive compounds, exerting anti-inflammatory, pro-apoptotic but also anti-invasive and anti-angiogenic effects. In the context of modern pharmacology, a better insight in the underlying mechanism of the broad range of bioactivities exerted by Withaferin A is compulsory. Therefore, a lot of effort was made to explore the intracellular effects of Withaferin A and to characterize its target proteins. This review provides a decisive insight on the molecular basis of the health-promoting potential of Withaferin A.

Withaferin A inhibits the proteasome activity in mesothelioma in vitro and in vivo

The medicinal plant Withania somnifera has been used for over centuries in Indian Ayurvedic Medicine to treat a wide spectrum of disorders. Withaferin A (WA), a bioactive compound that is isolated from this plant, has anti-inflammatory, immuno-modulatory, anti-angiogenic, and anti-cancer properties. Here we investigated malignant pleural mesothelioma (MPM) suppressive effects of WA and the molecular mechanisms involved. WA inhibited growth of the murine as well as patient-derived MPM cells in part by decreasing the chymotryptic activity of the proteasome that resulted in increased levels of ubiquitinated proteins and pro-apoptotic proteasome target proteins (p21, Bax, IκBα). WA suppression of MPM growth also involved elevated apoptosis as evidenced by activation of pro-apoptotic p38 stress activated protein kinase (SAPK) and caspase-3, elevated levels of pro-apoptotic Bax protein and cleavage of poly-(ADP-ribose)-polymerase (PARP). Our studies including gene-array based analyses further revealed that WA suppressed a number of cell growth and metastasis-promoting genes including c-myc. WA treatments also stimulated expression of the cell cycle and apoptosis regulatory protein (CARP)-1/CCAR1, a novel transducer of cell growth signaling. Knock-down of CARP-1, on the other hand, interfered with MPM growth inhibitory effects of WA. Intra-peritoneal administration of 5 mg/kg WA daily inhibited growth of murine MPM cell-derived tumors in vivo in part by inhibiting proteasome activity and stimulating apoptosis. Together our in vitro and in vivo studies suggest that WA suppresses MPM growth by targeting multiple pathways that include blockage of proteasome activity and stimulation of apoptosis, and thus holds promise as an anti-MPM agent.

Withaferin A-related steroids from Withania aristata exhibit potent antiproliferative activity by inducing apoptosis in human tumor cells

Six new withanolides (1-6) along with eleven known ones (7-17) were isolated from the leaves of Withania aristata. Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques. Semisynthesis of the minority metabolites 7 and 15 from compounds 6 and 9, respectively, as starting material, was performed. The isolated compounds as well as three derivatives (7a, 9a and 9b) of withaferin A were evaluated for cytotoxicity against HeLa (carcinoma of the cervix), A-549 (lung carcinoma) and MCF-7 (breast adenocarcinoma) human cancer cell lines, and against normal Vero cells (African green monkey kidney). Five compounds from this series (8, 9a, 9b, 11 and 13) exhibited potent antiproliferative effects on the tumor cells, even higher than the well known anticancer agent, withaferin A (9). Phosphatidylserine externalization, chromatin condensation, and caspase-3 activation clearly indicated apoptosis as a mechanism of action. The structure-activity relationship revealed valuable information on the pharmacophore for withanolide-type compounds.

Natural and synthetic α,β-unsaturated carbonyls for NF-κB inhibition

BACKGROUND

The nuclear transcription factor NF-κB has gained considerable importance due to its major involvement in inflammation and constitutive activity in malignant cells. It is induced by a variety of stimuli and controls the expression of several proteins involved in biological processes. Numerous natural products and synthesized organic molecules have been reported to inhibit NF-κB and have played an integral role in identifying implicated pathways. Prominent among them are the sesquiterpene lactones, polyphenolic enones and other α,β-unsaturated carbonyl-containing molecules, particularly α-methylene-γ-butyrolactones.

DISCUSSION

This mini-review provides an introductory overview of some of the associated pathways involving NF-κB in cancer and discusses the structures and mode of action of natural α,β-unsaturated carbonyl-containing inhibitors and their synthetic counterparts. A review of the recent methods for the synthesis of α-alkylidene-γ-butyrolactones is also provided, with the aim of arousing the interest of synthetic chemists for the design and development of novel NF-κB inhibitors.

CONCLUSIONS

Modulating damaging effects without harming the inflammatory and immune responses are crucial parameters for developing NF-κB inhibitors. Examination of novel α,β-unsaturated carbonyls and the further discovery of simple methods to prepare such molecules should lead to the identification of site-specific inhibitors.

Endoplasmic reticulum stress mediates withaferin A-induced apoptosis in human renal carcinoma cells

The accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER) results in cellular stress that initiates a specialized response designated as the unfolded protein response. ER stress has been implicated in a variety of common diseases, such as diabetes, ischemia and neurodegenerative disorders. Withaferin A, a major chemical constituent of Withania somnifera, has been reported to inhibit tumor cell growth. We show that withaferin A induced a dose-dependent apoptotic cell death in several types of human cancer cells, as measured by FACS analysis and PARP cleavage. Treatment of Caki cells with withaferin A induced a number of signature ER stress markers, including phosphorylation of eukaryotic initiation factor-2α (eIF-2 α), ER stress-specific XBP1 splicing, and up-regulation of glucose-regulated protein (GRP)-78. In addition, withaferin A caused up-regulation of CAAT/enhancer-binding protein-homologous protein (CHOP), suggesting the induction of ER stress. Pretreatment with N-acetyl cysteine (NAC) significantly inhibited withaferin A-mediated ER stress proteins and cell death, suggesting that reactive oxygen species (ROS) mediate withaferin A-induced ER stress. Furthermore, CHOP siRNA or inhibition of caspase-4 activity attenuated withaferin A-induced apoptosis. Taken together, the present study provides strong evidence supporting an important role of the ER stress response in mediating withaferin A-induced apoptosis.

Vimentin is a novel anti-cancer therapeutic target; insights from in vitro and in vivo mice xenograft studies

BACKGROUND

Vimentin is a ubiquitous mesenchymal intermediate filament supporting mechano-structural integrity of quiescent cells while participating in adhesion, migration, survival, and cell signaling processes via dynamic assembly/disassembly in activated cells. Soft tissue sarcomas and some epithelial cancers exhibiting "epithelial to mesenchymal transition" phenotypes express vimentin. Withaferin-A, a naturally derived bioactive compound, may molecularly target vimentin, so we sought to evaluate its effects on tumor growth in vitro and in vivo thereby elucidating the role of vimentin in drug-induced responses.

METHODS AND FINDINGS

Withaferin-A elicited marked apoptosis and vimentin cleavage in vimentin-expressing tumor cells but significantly less in normal mesenchymal cells. This proapoptotic response was abrogated after vimentin knockdown or by blockade of caspase-induced vimentin degradation via caspase inhibitors or overexpression of mutated caspase-resistant vimentin. Pronounced anti-angiogenic effects of Withaferin-A were demonstrated, with only minimal effects seen in non-proliferating endothelial cells. Moreover, Withaferin-A significantly blocked soft tissue sarcoma growth, local recurrence, and metastasis in a panel of soft tissue sarcoma xenograft experiments. Apoptosis, decreased angiogenesis, and vimentin degradation were all seen in Withaferin-A treated specimens.

CONCLUSIONS

In light of these findings, evaluation of Withaferin-A, its analogs, or other anti-vimentin therapeutic approaches in soft tissue sarcoma and "epithelial to mesenchymal transition" clinical contexts is warranted.

Generation of monoclonal antibodies to surface proteins of human multiple myeloma employing membrane extracts for murine in vivo immunizations

Multiple myeloma is a malignancy of plasma cells that accounts for 1% of cancers worldwide and is treatable, yet incurable. U266 is an IgE-secreting, IL-6-producing human multiple myeloma cell line, against whose unique surface markers we have tried to raise monoclonal antibodies (MAbs). Female Balb/c mice (6 weeks old) were immunized through two routes of administration, with three different antigenic concentrations. Fusion efficiencies and specific efficiencies for the three antigenic concentrations were calculated. It was found that while an initial immunogen concentration of 10 microg gave the best fusion efficiency of 63.89%, an initial immunogen concentration of 15 microg resulted in the best specific efficiency of 54.54%. Out of the 147 supernatants selected for screening, 66 were found reactive to common surface proteins of non-malignant human plasma cells and seven were myeloma-specific MAbs. These MAbs have a range of potential applications in multiple myeloma imaging, phenotyping, and possible targeted therapy.

Serum markers of apoptosis decrease with age and cancer stage

The physical manifestations of aging reflect a loss of homeostasis that effects molecular, cellular and organ system functional capacity. As a sentinel homeostatic pathway, changes in apoptosis can have pathophysiological consequences in both aging and disease. To assess baseline global apoptosis balance, sera from 204 clinically normal subjects had levels of sFas (inhibitor of apoptosis), sFasL (stimulator of apoptosis), and total cytochrome c (released from cells during apoptosis) measured. Serum levels of sFas were significantly higher while sFasL and cytochrome c levels were lower in men compared to women. With increasing age there was a decrease in apoptotic markers (cytochrome c) and pro-apoptotic factors (sFasL) and an increase in anti-apoptotic factors (sFas) in circulation. The observed gender differences are consistent with the known differences between genders in mortality and morbidity. In a separate cohort, subjects with either breast (n = 66) or prostate cancer (n = 38) exhibited significantly elevated sFas with reduced sFasL and total cytochrome c regardless of age. These markers correlated with disease severity consistent with tumor subversion of apoptosis. The shift toward less global apoptosis with increasing age in normal subjects is consistent with increased incidence of diseases whose pathophysiology involves apoptosis dysregulation.