The protective role of the immunomodulator AS101 against chemotherapy-induced alopecia studies on human and animal models

Commonly prescribed medications associated with alopecia

BACKGROUND

The diagnosis and treatment of medication-associated alopecia often challenges patients and physicians. While numerous studies on the topic exist, limited information on the strength and magnitude of these studies exists.

OBJECTIVES

We investigated the most commonly prescribed medications with high levels of evidence to support associations with alopecia.

METHODS

A list of most commonly prescribed medications was compiled using the "Top 100 Prescriptions, Sales" (Intercontinental Marketing Services) and "Top 200 Names Searched" (RxList.com). PubMed, Embase, and Web of Science were searched for "generic drug name" AND "alopecia" and "generic drug name" AND "hair loss." Two reviewers independently reviewed articles for drug, study type and level of evidence, and number of alopecia cases.

RESULTS

A total of 192 unique drugs were investigated, with 110 yielding positive search results. Of these, 13 were associated with alopecia in studies with strong levels of evidence (adalimumab, infliximab, budesonide, interferon β-1α, tacrolimus, enoxaparin, zoster vaccine, lamotrigine, docetaxel, capecitabine, erlotinib, imatinib, and bortezomib).

LIMITATIONS

Only full-length articles available in the English language were included. The methodology used relied on lists of drugs based on their sales rather than number of prescriptions, which likely overrepresented expensive drugs.

CONCLUSIONS

Few studies with high levels of evidence have been conducted on the topic of medication-associated alopecia. The mechanisms of hair loss must be further identified to provide effective management.

Improving Quality of Life During Chemotherapy: Cannabinoids, Cryotherapy, and Scalp Cooling

There have been significant advances in the treatment of cancer in the past decade. However, patients continue to suffer from significant side effects of antineoplastic agents that greatly affect their quality of life (QOL), including chemotherapy-induced nausea and vomiting (CINV), chemotherapy-induced peripheral neuropathy (CIPN), and chemotherapy-induced alopecia (CIA). This review aims to provide an updated overview of emerging strategies for the management and prevention of these immediate and long-lasting side effects. The use of integrative medicine including cannabis continues to evolve in the realm of CINV and cancer-related anorexia. Although no pharmaceutical agent has been approved for the prevention of CIPN, cryotherapy, compression therapy and, more recently, cryocompression therapy have shown benefit in small trials, but there are concerns with tolerability especially related to cryotherapy. More data are necessary to determine an effective and tolerable option to prevent CIPN in large, randomized studies. Scalp cooling (SC), which has a similar mechanism to cryotherapy and compression therapy for CIPN prevention, has proven to be an effective and tolerable approach in randomized studies and has significantly limited CIA, an entity that definitively affects the QOL of patients living with cancer. Taken together, cannabis, cryotherapy, compression and cryocompression therapy, and SC all strive to improve the QOL of patients living with cancer by minimizing the side effects of chemotherapeutic agents.

Mild oxidative stress protects against chemotherapy-induced hair loss

Chemotherapy induces hair loss in most cancer patients who undergo treatment, which causes them significant psychosocial trauma. Scalp cooling has demonstrated some efficacy in attenuating chemotherapy-induced alopecia, but response rate varies between patients and chemotherapy class. Here, we showcase in rats a proof-of-concept treatment of using subcutaneous hydrogen peroxide and cumene hydroperoxide injections to provide total protection from hair loss against multiple classes of chemotherapy. We found that subcutaneous peroxides induce cell cycle arrest via P53 activation, thereby protecting hair follicles from the cytotoxic effects of chemotherapy on actively dividing cells. This treatment represents a highly effective and accessible way for cancer patients to maintain quality of life while undergoing treatment for cancer.

Latest developments on the synthesis of bioactive organotellurium scaffolds

This review deals with the latest developments on the synthesis of biologically promising organotellurim scaffolds reported during last two decades.

Synthesis, Mechanism Elucidation and Biological Insights of Tellurium(IV)-Containing Heterocycles

Inspired by the synthetic and biological potential of organotellurium substances, a series of five- and six-membered ring organotelluranes containing a Te-O bond were synthesized and characterized. Theoretical calculations elucidated the mechanism for the oxidation-cyclization processes involved in the formation of the heterocycles, consistent with chlorine transfer to hydroxy telluride, followed by a cyclization step with simultaneous formation of the new Te-O bond and deprotonation of the OH group. Moreover, theoretical calculations also indicated anti-diastereoisomers to be major products for two chirality center-containing compounds. Antileishmanial assays against Leishmania amazonensis promastigotes disclosed 1,2λ⁴ -oxatellurane LQ50 (IC₅₀ =4.1±1.0; SI=12), 1,2λ⁴ -oxatellurolane LQ04 (IC₅₀ =7.0±1.3; SI=7) and 1,2λ⁴ -benzoxatellurole LQ56 (IC₅₀ =5.7±0.3; SI=6) as more powerful and more selective compounds than the reference, being up to four times more active. A stability study supported by ¹²⁵ Te NMR analyses showed that these heterocycles do not suffer structural modifications in aqueous-organic media or at temperatures up to 65 °C.

The tellurium-based immunomodulator, AS101 ameliorates adjuvant-induced arthritis in rats

Despite undeniable improvement in the management of rheumatoid arthritis (RA), the discovery of more effective, less toxic and, ideally, less immune suppressive drugs are much needed. In the current study, we set to explore the potential anti-rheumatic activity of the non-toxic, tellurium-based immunomodulator, AS101 in an experimental animal model of RA. The effect of AS101 was assessed on adjuvant-induced arthritis (AIA) rats. Clinical signs of arthritis were assessed. Histopathological examination was used to assess inflammation, synovial changes and tissue lesions. Very late antigen-4 (VLA-4)+ cellular infiltration was detected using immunohistochemical staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure circulating anti-cyclic citrullinated-peptide autoantibody (ACPA) and real-time polymerase chain reaction (PCR) was used to measure the in-vitro effect of AS101 on interleukin (IL)-6 and IL-1β expression in activated primary human fibroblasts. Prophylactic treatment with intraperitoneal AS101 reduced clinical arthritis scores in AIA rats (P < 0·01). AS101 abrogated the migration of active chronic inflammatory immune cells, particularly VLA-4+ cells, into joint cartilage and synovium, reduced the extent of joint damage and preserved joint architecture. Compared to phosphate-buffered saline (PBS)-treated AIA rats, histopathological inflammatory scores were significantly reduced (P < 0·05). Furthermore, AS101 resulted in a marked reduction of circulating ACPA in comparison to PBS-treated rats (P < 0·05). Importantly, AS101 significantly reduced mRNA levels of proinflammatory mediators such as IL-6 (P < 0·05) and IL-1β (P < 0·01) in activated primary human fibroblasts. Taken together, we report the first demonstration of the anti-rheumatic/inflammatory activity of AS101 in experimental RA model, thereby supporting an alternative early therapeutic intervention and identifying a promising agent for therapeutic intervention.

Tellurium compound provides pro-apoptotic signaling in drug resistant multiple myeloma

Multiple Myeloma, effectively treated by chemotherapeutic drugs, relapses due to drug resistance. We tested here the capacity of mesenchymal stromal cells, from the bone marrow of patients or from adipose tissue of healthy individuals, to induce drug resistance in Myeloma cell lines. We show that drug resistance can be achieved by factors secreted by the various MSC's. Mass spectrometry analysis of MSC's conditioned media revealed that fibronectin, was particularly instrumental in providing anti-apoptotic signals to MM cells. Moreover, we demonstrate that SAS ([octa-O-bis-(R,R)tartarate ditellurane]), an immunomodulator Tellurium compound, is not only able of blocking the physical interaction between MM cells and fibronectin but is also capable of re-sensitizing the cells to the chemotherapeutic drugs. Finally, we show that this re-sensitization is coupled with the blocking of pAKT induction, in MM cells, by the MSC's. These results indicate that SAS may be useful in the treatment of drug resistant MM.

Evaluation of efficacy of QR678® and QR678® Neo hair growth factor formulation in the treatment of persistent chemotherapy-induced alopecia caused due to cytotoxic chemotherapy-A prospective pilot study

BACKGROUND

Cancers are one of the main reasons of morbidity and mortality globally. Chemotherapy-induced alopecia (CIA) is one of the most alarming, terrifying, and traumatic adverse effects. A range of therapeutic measures has been suggested to alleviate CIA, but at present, there is no accepted pharmacological therapy that can assure prevention or management.

AIM

The aim of the present study was to evaluate the efficacy of QR 678 Neo® therapy in the treatment of persistent chemotherapy-induced alopecia in women and men treated with cytotoxic chemotherapy for breast and lung cancers, respectively.

METHODS

A total of 8 male patients with history of lung cancer and 12 female patients with history of breast cancer in the age range of 25-60 years, with WHO classification of grade I and II persistent alopecia who had undergone chemotherapy treatment, were selected for the study. At each visit, 1.5 mL solution of QR 678^® was injected into the scalp skin of patients. A total of 8 sessions were performed at an interval of 3 weeks each. All the patients were evaluated with standard global photography, video microscopic assessment, and patient self-assessment questionnaire at baseline, 6 months, and 1 year.

RESULTS

Marked improvement was seen in the global assessment score at 6 months (mean-8) which was maintained even after 1 year. Mean score increase in hair count at 6 months was 12.71 which further increased at 1 year. High satisfaction score was given by patients for slowing of hair loss (mean = 4.2) and also for overall hair growth. For appearance and growth of hair, the mean value was 3.4 and 3.8, respectively.

CONCLUSION

The formulation of QR 678^® and QR 678^® Neo showed to be significantly safe and efficient for chemotherapy-induced alopecia in both men and women. Improvement in hair growth was maintained even at 1 year of follow-up. No patient had any severe adverse effects, and injections were also easily bearable by most of them.

Scalp cooling to prevent chemotherapy-induced alopecia

Chemotherapy-induced alopecia causes an important impact on cancer patients and its risk of persistence is currently a considerable issue in cancer survivors. Of the various interventions proposed for the prevention of chemotherapy-induced alopecia, scalp cooling has emerged as an effective and safe strategy. This paper aims to provide an overview on scalp cooling and chemotherapy-induced alopecia prevention.

Antitumor effect of chiral organotelluranes elicited in a murine melanoma model

Protease roles in cancer progression have been demonstrated and their inhibitors display antitumor effects. Cathepsins are lysosomal cysteine proteases that have increased expression in tumor cells, and tellurium compounds were described as potent cysteine protease inhibitors and also assayed in several animal models. In this work, the two enantiomeric forms of 1-[Butyl(dichloro)-λ⁴-tellanyl]-2-[1S-methoxyethyl]benzene (organotelluranes RF-13R and RF-13S) were evaluated as inhibitors of cathepsins B and L, showing significant enantiodiscrimination. We observed their cytotoxic effects on a murine melanoma model, effectively inhibiting tumor progression in vivo. The enantiomers were able to inhibit melanoma cell viability, migration and invasion in vitro. Besides, RF-13S and RF-13R were able to inhibit endothelial cell angiogenesis using a tube formation assay in vitro, in a stereodependent manner. These organotelluranes affected cell morphology, showing disassembling of the actin cytoskeleton. These results suggest organotelluranes as potential antitumor agents, acting directly on tumor cell proliferation, migration and invasion, and on endothelial cells, disrupting angiogenesis, showing low toxicity and high efficiency. Taken together our results suggest that this class of compounds should be further studied to reveal their potential as antitumoral agents.

Tellurium Compounds Prevent and Reverse Type-1 Diabetes in NOD Mice by Modulating α4β7 Integrin Activity, IL-1β, and T Regulatory Cells

The study shows that treatment of NOD mice with either of two tellurium-based small molecules, AS101 [ammonium trichloro(dioxoethylene-o,o')tellurate] or SAS [octa-O-bis-(R,R)-tartarate ditellurane] could preserve β cells function and mass. These beneficial effects were reflected in decreased incidence of diabetes, improved glucose clearance, preservation of body weight, and increased survival. The normal glucose levels were associated with increased insulin levels, preservation of β cell mass and increased islet size. Importantly, this protective activity could be demonstrated when the compounds were administered either at the early pre-diabetic phase with no or initial insulitis, at the pre-diabetic stage with advanced insulitis, or even at the advanced, overtly diabetic stage. We further demonstrate that both tellurium compounds prevent migration of autoimmune lymphocytes to the pancreas, via inhibition of the α4β7 integrin activity. Indeed, the decreased migration resulted in diminished pancreatic islets damage both with respect to their size, β cell function, and caspase-3 activity, the hallmark of apoptosis. Most importantly, AS101 and SAS significantly elevated the number of T regulatory cells in the pancreas, thus potentially controlling the autoimmune process. We show that the compounds inhibit pancreatic caspase-1 activity followed by decreased levels of the inflammatory cytokines IL-1β and IL-17 in the pancreas. These properties enable the compounds to increase the proportion of Tregs in the pancreatic lymph nodes. AS101 and SAS have been previously shown to regulate specific integrins through a unique redox mechanism. Our current results suggest that amelioration of disease in NOD mice by this unique mechanism is due to decreased infiltration of pancreatic islets combined with increased immune regulation, leading to decreased inflammation within the islets. As these tellurium compounds show remarkable lack of toxicity in clinical trials (AS101) and pre-clinical studies (SAS), they may be suitable for the treatment of type-1 diabetes.

Stability of antibacterial Te(IV) compounds: A combined experimental and computational study

Inorganic Te(IV) compounds are important cysteine protease inhibitors and antimicrobial agents; AS-101 [ammonium trichloro (dioxoethylene-O,O')tellurate] is the first compound of a family with formula NH₄[C₂H₄Cl₃O₂Te], where a Te(IV) centre is bound to a chelate ethylene glycol, and showed several protective therapeutic applications. This compound is lacking in stability performance and is subjected to hydrolysis reaction with displacement of the diol ligand. In this paper, we report the stability trend of a series of analogues complexes of AS-101 with generic formula NH₄[(RC₂H₃O₂)Cl₃Te], where R is an alkyl group with different chain length and different electronic properties, in order to find a correlation between structure and stability in aqueous-physiological conditions. The stability was studied in solution via multinuclear NMR spectroscopy (¹H, ¹³C, ¹²⁵Te) and computationally at the Density Functional Theory level with an explicit micro solvation model. The combined experimental and theoretical work highlights the essential role of the solvating environment and provides mechanistic insights into the complex decomposition reaction. Antimicrobial activity of the compounds was assessed against different bacterial strains.

Computational Drug Discovery in Chemotherapy-induced Alopecia via Text Mining and Biomedical Databases

PURPOSE

Chemotherapy-induced alopecia (CIA) is a common and often stressful adverse effect associated with chemotherapy. CIA can cause more psychosocial pressure in patients, including effects on sexuality, self-esteem, and social relationships. We analyzed publicly available data to identify drugs formulated for topical use targeting the relevant CIA molecular pathways by using computational tools.

METHODS

The genes associated with CIA were determined by text mining, and the gene ontology of the gene set was studied using the Functional Enrichment analysis tool. Protein-protein interaction network analysis was performed using the String database. Enriched gene sets belonging to the identified pathways were queried against the Drug-Gene Interaction database to find drug candidates for topical use in CIA.

FINDINGS

Our analysis identified 427 genes common to CIA text-mining concepts. Gene enrichment analysis and protein-protein interaction analysis yielded 19 genes potentially targetable by a total of 29 drugs that could possibly be formulated for topical application.

IMPLICATIONS

The findings from the present analysis would give a new thought to help discover more effective agents, and present tremendous opportunities to study novel target pharmacology and facilitate drug repositioning efforts in the pharmaceutical industry.

Permanent Chemotherapy-Induced Alopecia in Patients with Breast Cancer: A 3-Year Prospective Cohort Study

Chemotherapy‐induced alopecia is (CIA) considered temporary; however, some patients report persistent alopecia several years after chemotherapy. Long‐term prospective data on the incidence and impact of permanent CIA is scarce. This article reports the results of a study conducted to estimate the long‐term incidence of persistent CIA in a cohort of breast cancer patients with measurements of hair volume and density before and after chemotherapy.

Background.

Although chemotherapy‐induced alopecia (CIA) is considered temporary, some patients report persistent alopecia several years after chemotherapy. There is, however, a paucity of long‐term prospective data on the incidence and impact of permanent CIA (PCIA). The objective of our study was to estimate the long‐term incidence of PCIA in a cohort of patients with breast cancer whose hair volume and density were measured prior to chemotherapy and who were followed for 3 years after chemotherapy.

Materials and Methods.

Prospective cohort study of consecutive patients ≥18 years of age with postoperative diagnosis of stage I–III breast cancer expected to receive adjuvant chemotherapy at the outpatient breast cancer clinic at the Samsung Medical Center in Seoul, Korea, from February 2012 to July 2013 (n = 61). Objective hair density and thickness were measured using a noninvasive bioengineering device.

Results.

The proportion of participants who had PCIA at 6 months and 3 years was 39.5% and 42.3%, respectively. PCIA was characterized in most patients by incomplete hair regrowth. Patients who received a taxane‐based regimen were more likely to experience PCIA compared with patients with other types of chemotherapy. At a 3‐year follow‐up, hair thinning was the most common problem reported by study participants (75.0%), followed by reduced hair volume (53.9%), hair loss (34.6%), and gray hair (34.6%).

Conclusion.

PCIA is a common adverse event of breast cancer adjuvant cytotoxic chemotherapy. Clinicians should be aware of this distressing adverse event and develop supportive care strategies to counsel patients and minimize its impact on quality of life.

Implications for Practice.

Knowledge of permanent chemotherapy‐induced alopecia, an under‐reported adverse event, should lead to optimized pretherapy counseling, anticipatory coping techniques, and potential therapeutic strategies for this sequela of treatment.

Hair disorders in patients with cancer

Cytotoxic chemotherapies, molecularly targeted therapies, immunotherapies, radiotherapy, stem cell transplants, and endocrine therapies may lead to hair disorders, including alopecia, hirsutism, hypertrichosis, and pigmentary and textural hair changes. The mechanisms underlying these changes are varied and remain incompletely understood, hampering the development of preventive or therapeutic guidelines. The psychosocial impact of chemotherapy-induced alopecia has been well documented primarily in the oncology literature; however, the effect of other alterations, such as radiation-induced alopecia, hirsutism, and changes in hair color or texture on quality of life have not been described. This article reviews clinically significant therapy-related hair disorders in oncology patients, including the underlying pathophysiological mechanisms, severity grading scales, patient-reported quality of life questionnaires, management strategies, and future translational research opportunities.

A Clinical and Biological Guide for Understanding Chemotherapy-Induced Alopecia and Its Prevention

Chemotherapy-induced alopecia (CIA) is the most visibly distressing side effect of commonly administered chemotherapeutic agents. Because psychological health has huge relevance to lifestyle, diet, and self-esteem, it is important for clinicians to fully appreciate the psychological burden that CIA can place on patients. Here, for the first time to our knowledge, we provide a comprehensive review encompassing the molecular characteristics of the human hair follicle (HF), how different anticancer agents damage the HF to cause CIA, and subsequent HF pathophysiology, and we assess known and emerging prevention modalities that have aimed to reduce or prevent CIA. We argue that, at present, scalp cooling is the only safe and U.S. Food and Drug Administration-cleared modality available, and we highlight the extensive available clinical and experimental (biological) evidence for its efficacy. The likelihood of a patient that uses scalp cooling during chemotherapy maintaining enough hair to not require a wig is approximately 50%. This is despite different types of chemotherapy regimens, patient-specific differences, and possible lack of staff experience in effectively delivering scalp cooling. The increased use of scalp cooling and an understanding of how to deliver it most effectively to patients has enormous potential to ease the psychological burden of CIA, until other, more efficacious, equally safe treatments become available.

IMPLICATIONS FOR PRACTICE

Chemotherapy-induced alopecia (CIA) represents perhaps the most distressing side effect of chemotherapeutic agents and is of huge concern to the majority of patients. Scalp cooling is currently the only safe option to combat CIA. Clinical and biological evidence suggests improvements can be made, including efficacy in delivering adequately low temperature to the scalp and patient-specific cap design. The increased use of scalp cooling, an understanding of how to deliver it most effectively, and biological evidence-based approaches to improve its efficacy have enormous potential to ease the psychological burden of CIA, as this could lead to improvements in treatment and patient quality-of-life.

The Small Tellurium Compound AS101 Ameliorates Rat Crescentic Glomerulonephritis: Association with Inhibition of Macrophage Caspase-1 Activity via Very Late Antigen-4 Inactivation

Crescentic glomerulonephritis (CGN) is the most aggressive form of GN and, if untreated, patients can progress to end-stage renal failure within weeks of presentation. The α4β1 integrin very late antigen-4 (VLA-4) is an adhesion molecule of fundamental importance to the recruitment of leukocytes in inflammation. We addressed the role of VLA-4 in mediating progressive renal injury in a rat model of CGN using a small tellurium compound. AS101 [ammonium trichloro(dioxoethylene-o,o')tellurate]. This compound has been previously shown to uniquely inhibit VLA-4 activity by redox inactivation of adjacent thiols in the exofacial domain of VLA-4. The study shows that administration of AS101 either before or after glomerular basement membrane anti-serum injection ameliorates crescent formation or preserves renal function. This was associated with profound inhibition of critical inflammatory mediators, accompanied by decreased glomerular infiltration of macrophages. Mechanistic studies demonstrated vla-4 inactivation on glomerular macrophages both in vitro and in vivo as well as inhibition of caspase-1 activity. Importantly, this cysteine protease activity modification was dependent on VLA-4 inactivation and was associated with the anti-inflammatory activity of AS101. We propose that inactivation of macrophage VLA-4 by AS101 in vivo results in a decrease of inflammatory cytokines and chemokines produced in the glomeruli of diseased rats, resulting in decreased further macrophage recruitment and decreased extracellular matrix expansion. Thus, AS101, which is currently in clinical trials for other indications, might be beneficial for treatment of CGN.

Drug discovery for alopecia: gone today, hair tomorrow

INTRODUCTION

Hair loss or alopecia affects the majority of the population at some time in their life, and increasingly, sufferers are demanding treatment. Three main types of alopecia (androgenic [AGA], areata [AA] and chemotherapy-induced [CIA]) are very different, and have their own laboratory models and separate drug-discovery efforts.

AREAS COVERED

In this article, the authors review the biology of hair, hair follicle (HF) cycling, stem cells and signaling pathways. AGA, due to dihydrotesterone, is treated by 5-α reductase inhibitors, androgen receptor blockers and ATP-sensitive potassium channel-openers. AA, which involves attack by CD8(+)NK group 2D-positive (NKG2D(+)) T cells, is treated with immunosuppressives, biologics and JAK inhibitors. Meanwhile, CIA is treated by apoptosis inhibitors, cytokines and topical immunotherapy.

EXPERT OPINION

The desire to treat alopecia with an easy topical preparation is expected to grow with time, particularly with an increasing aging population. The discovery of epidermal stem cells in the HF has given new life to the search for a cure for baldness. Drug discovery efforts are being increasingly centered on these stem cells, boosting the hair cycle and reversing miniaturization of HF. Better understanding of the molecular mechanisms underlying the immune attack in AA will yield new drugs. New discoveries in HF neogenesis and low-level light therapy will undoubtedly have a role to play.

The effect of the novel tellurium compound AS101 on autoimmune diseases

Tellurium is a rare element, which has been regarded as a non-essential trace element despite its relative abundance in the human body. The chemistry of tellurium supports a plethora of activities, but its biochemistry is not clearly established to date. The small tellurium(IV) compound, ammonium trichloro (dioxoethylene-o,o')tellurate (AS101) developed and initially investigated by us, is currently being evaluated in Phase II clinical trials in psoriasis patients. AS101 is the first tellurium compound to be tested for clinical efficacy. This compound is a potent immunomodulator both in vitro and in vivo with a variety of potential therapeutic applications. The present review will focus on the immunomodulatory properties of AS101, and specifically, its effects in mitigating autoimmune diseases. AS101 has several activities that act on the immune system, including: 1) its ability to reduce IL-17 levels and to inhibit the function of Th17 cells; 2) its specific unique redox-modulating activities enabling the inhibition of specific leukocyte integrins such as α4β1 and α4β7, that are pivotal for diapedesis of macrophages and CD4(+) T inflammatory/auto-reactive cells into the autoimmune tissues; and 3) its ability to enhance the activity of regulatory T cells (Treg). These activities coupled with its excellent safety profile suggest that AS101 may be a promising candidate for the management of autoimmune diseases.

Efficacy of interventions for prevention of chemotherapy-induced alopecia: a systematic review and meta-analysis

Chemotherapy-induced alopecia (CIA) is a highly distressing event for cancer patients, and hence, we here aimed to assess the efficacy of various interventions in the prevention of CIA. We searched PubMed, EMBASE and the Cochrane Library, from June 20, 2013 through August 31, 2013. Two of the authors independently reviewed and selected clinical trials that reported the efficacy of any intervention for prevention of CIA compared with that of controls. Two authors extracted data independently on dichotomized outcome in terms of CIA occurrence. Relative risks (RRs) and 95% confidential intervals (CIs) were calculated for efficacy of CIA prevention by using random-effect or fixed-effect models. Out of 691 articles retrieved, a total of eight randomized controlled trials and nine controlled clinical trials involving 1,098 participants (616 interventions and 482 controls), were included in the final analyses. Scalp cooling, scalp compression, a combination of cooling and compression, topical minoxidil and Panicum miliaceum were used as interventions. The participants were mainly breast cancer patients receiving doxorubicin- or epirubicin-containing chemotherapy. Scalp cooling, which is the most popular preventive method, significantly reduced the risk of CIA (RR = 0.38, 95% CI = 0.32-0.45), whereas topical 2% minoxidil and other interventions did not significantly reduce the risk of CIA. No serious adverse effects associated with scalp cooling were reported. Our results suggest that scalp cooling can prevent CIA in patients receiving chemotherapy. However, the long-term safety of scalp cooling should be confirmed in further studies.

A new strategy to prevent chemotherapy and radiotherapy-induced alopecia using topically applied vasoconstrictor

In a new strategy, we sought to determine whether topically applied vasoconstrictor, with its accompanying transient skin hypoxia and exclusion of systemic drug, would prevent or suppress radiotherapy or chemotherapy-induced alopecia. Topical vasoconstrictor was applied to 1-cm(2) skin patches on the backs of 10-day-old rats and minutes later they received either 7.1 gray (Gy) whole-body radiation or systemic N-nitroso-N-methylurea (MNU) or Cytoxan. The degree of alopecia was scored 10 days later by visual assessment (% coat retention) and hair follicle histologic analysis. Topical application of epinephrine or norepinephrine in an alcohol:water delivery vehicle induced clear skin blanch, and in a dose-dependent manner, topical epinephrine or norepinephrine (20-1,000 mM) applied before 7.1 Gy irradiation conferred 95% of coat retention in the treated skin patches versus 0% coat retention in vehicle controls, or in skin outside the treated patches. By histology, small numbers of dystrophic hair follicles were observed in hairless skin versus the normal density of anagen follicles in the immediately adjacent, drug-protected skin patches at day 20; protected coats were retained into adulthood. Topical epinephrine or norepinephrine before systemic MNU (30 ug/gm body weight) conferred up to 95% of coat retention in treated skin patches versus 0% coat retention elsewhere. Epinephrine-conferred % coat retention dropped to 16% in rats that received systemic Cytoxan, a drug whose plasma half-life is at least 8- to 10-fold longer than MNU. A general strategy is discussed for the use of topical epinephrine or norepinephrine in the clinic to provide an inexpensive and convenient strategy to prevent cancer therapy-induced alopecia.

Multifunctional activity of a small tellurium redox immunomodulator compound, AS101, on dextran sodium sulfate-induced murine colitis

Inflammatory bowel diseases (IBDs) are a group of idiopathic, chronic immune-mediated diseases characterized by an aberrant immune response, including imbalances of inflammatory cytokine production and activated innate and adaptive immunity. Selective blockade of leukocyte migration into the gut is a promising strategy for the treatment of IBD. This study explored the effect of the immunomodulating tellurium compound ammonium trichloro (dioxoethylene-o,o') tellurate (AS101) on dextran sodium sulfate (DSS)-induced murine colitis. Both oral and intraperitoneal administration of AS101 significantly reduced clinical manifestations of IBD. Colonic inflammatory cytokine levels (IL-17 and IL-1β) were significantly down-regulated by AS101 treatment, whereas IFN-γ was not affected. Neutrophil and α4β7(+) macrophage migration into the tissue was inhibited by AS101 treatment. Adhesion of mesenteric lymph node cells to mucosal addressin cell adhesion molecule (MAdCAM-1), the ligand for α4β7 integrin, was blocked by AS101 treatment both in vitro and in vivo. DSS-induced destruction of colonic epithelial barrier/integrity was prevented by AS101, via up-regulation of colonic glial-derived neurotrophic factor, which was found previously to regulate the intestinal epithelial barrier through activation of the PI3K/AKT pathway. Indeed, the up-regulation of glial-derived neurotrophic factor by AS101 was associated with increased levels of colonic pAKT and BCL-2 and decreased levels of BAX. Furthermore, AS101 treatment reduced colonic permeability to Evans blue and decreased colonic TUNEL(+) cells. Our data revealed multifunctional activities of AS101 in the DSS-induced colitis model via anti-inflammatory and anti-apoptotic properties. We suggest that treatment with the small, nontoxic molecule AS101 may be an effective early therapeutic approach for controlling human IBD.

Novel microwave-assisted synthesis of the immunomodulator organotellurium compound ammonium trichloro(dioxoethylene-O,O')tellurate (AS101)

Ammonium trichloro[1,2-ethanediolato-O,O′]-tellurate (AS101) is the most important synthetic Te compound from the standpoint of its biological activity. It is a potent immunomodulator with a variety of potential therapeutic applications and antitumoral action in several preclinical and clinical studies. An experimental design has been used to develop and optimize a novel microwave-assisted synthesis (MAOS) of the AS101. In comparison to the results observed in the literature, refluxing Te(IV) chloride and ethylene glycol in acetonitrile (Method A), or by refluxing Te(IV) chloride and ammonium chloride in ethylene glycol (Method B), it was found that the developed methods in the present work are an effective alternative, because although performance slightly decreases compared to conventional procedures (75% vs. 79% by Method A, and 45% vs. 51% by Method B), reaction times decreased from 4 h to 30 min and from 4 h to 10 min, by Methods A and B respectively. MAOS is proving to be of value in the rapid synthesis of compounds with new and improved biological activities, specially based on the benefit of its shorter reaction times.

Cyclophosphamide triggers follicle activation and "burnout"; AS101 prevents follicle loss and preserves fertility

Premature ovarian failure and infertility are major side effects of chemotherapy treatments in young cancer patients. A more thorough understanding of the mechanism behind chemotherapy-induced follicle loss is necessary to develop new methods to preserve fertility in these patients. We show that the alkylating agent cyclophosphamide (Cy) activates the growth of the quiescent primordial follicle population in mice, resulting in loss of ovarian reserve. Despite the initial massive apoptosis observed in growing, though not in resting, follicles of Cy-treated mice, differential follicle counts demonstrated both a decrease in primordial follicles and an increase in early growing follicles. Immunohistochemistry showed that granulosa cells were undergoing proliferation. Analysis of the phosphatidylinositol 3-kinase signaling pathway demonstrated that Cy increased phosphorylation of proteins that stimulate follicle activation in the oocytes and granulosa cells. Coadministration of an immunomodulator, AS101, reduced follicle activation, thereby increasing follicle reserve and rescuing fertility after Cy, and also increased the efficacy of Cy against breast cancer cell lines. These findings suggest that the mechanism in Cy-induced loss of ovarian reserve is accelerated primordial follicle activation, which results in a "burnout" effect and follicle depletion. By preventing this activation, AS101 shows potential as an ovarian-protective agent, which may be able to preserve fertility in female cancer patients.

The Tellurium compound, AS101, increases SIRT1 level and activity and prevents type 2 diabetes

The histone deacetylase, SIRT1, plays a major role in glucose regulation and lipid metabolism. Ammonium Trichloro (dioxoethylene-o,o') Tellurate, AS101, is a potent in vitro and in vivo immunomodulator, with several potential therapeutic applications. AS101 administration resulted in upregulation of SIRT1 protein expression and activity. These effects were associated with decreased levels of serum insulin like growth factor-1 (IGF-1) and of insulin. The properties of AS101 prompted us to investigate its potential therapeutic role in rats with type 2 diabetes (T2D). T2D was induced by a high fat diet combined with a low dose of Streptozotocin (STZ). Treatment with AS101 before manifestation of hyperglycemia, resulted in increased insulin sensitivity, and decreased blood glucose levels, and prevented symptoms of diabetes including defective glucose clearance, fatty liver, and abnormal distribution of insulin-producing beta cells in the pancreas. Treatment after disease emergence resulted in partial restoration of normal glucose homeostasis. Diabetic rats showed a reduction in liver SIRT1 levels. In both treatment regimens the reduction in SIRT1 levels in the liver were blocked by AS101 consumption. Together, these findings demonstrate the therapeutic potential of AS101 for treating T2D, and for reversing impaired fat and glucose metabolism.

The immune-modulator AS101 reduces anti-HLA antibodies in sera of sensitized patients: a structural approach

BACKGROUND

Significant efforts are dedicated to identification of agents that eliminate anti-HLA antibodies (Ab) from sera of transplant candidates. Antibody titer following in vitro incubation of sera with desensitizing agents has shown to reflect the probability that a patient would benefit from clinical de-sensitization protocols. AS101 is a non-toxic, synthetic, organic tellurium compound. The aim of this research was to assess the ability of AS101 to reduce anti-HLA Abs and to identify patients likely to benefit from this effect.

METHODS

Sera of sensitized patients awaiting transplant were incubated in the presence of AS101. Measured mean fluorescence intensity (MFI) represents reactivity of anti HLA Abs in the serum, as detected by the Luminex platform. The repertoire of HLA antigen epitopes was recognized using HLA Matchmaker software.

RESULTS

AS101 Incubation caused a significant Ab titer decrease in approximately two thirds of the samples. The median Class I and II MFI decrease among the responding samples was 16.7% and 14%, respectively (p<0.05). HLA Matchmaker analysis of the patients' class I epitope sequences revealed apparent amino-acid differences between the patterns of the responding and non-responding patients.

CONCLUSION

In vitro incubation of sera in the presence of AS101 causes a decrease in the anti-HLA Ab's reactivity in several patient samples. Sera most likely to demonstrate this effect are characterized by a moderate MFI level and a distinct antibody reactivity pattern specific for defined HLA antigen epitopes. These results support further investigation of AS101 as a potential agent for desensitization of humoral reactivity prior to transplantation.

A novel rat model for chemotherapy-induced alopecia

BACKGROUND

More than half of all people diagnosed with cancer receive chemotherapy, and approximately 65% of these develop chemotherapy-induced alopecia (CIA), a side-effect that can have considerable negative psychological repercussions. Currently, there are very few animal models available to study the mechanism and prevention of CIA.

AIM

To develop a clinically relevant adult rat model for CIA.

METHODS

We first tested whether neonatal pigmented Long-Evans (LE) rats developed alopecia in response to the chemotherapeutic agents etoposide and cyclophosphamide. We then determined whether the rats developed CIA as adults. In the latter experiment, rat dorsal hair was clipped during the early telogen stage to synchronize the hair cycle, and starting 15 days later, the rats were treated with etoposide for 3 days.

RESULTS

Neonatal LE pups developed CIA in response to etoposide and cyclophosphamide, similar to other murine models for CIA. Clipping of the hair shaft during early telogen resulted in synchronized anagen induction and subsequent alopecia after etoposide treatment in the clipped areas only. Hair follicles in the clipped areas had the typical chemotherapy-induced follicular dystrophy (dystrophic catagen). When the hair in the pigmented alopecic areas regrew, it had normal pigmentation.

CONCLUSIONS

A novel, pigmented adult rat model has been established for CIA. By hair-shaft clipping during early telogen, synchronized anagen entry was induced, which resulted in alopecia in response to chemotherapy. This is the first clinically relevant adult rat model for CIA, and will be a useful tool to test agents for the prevention and treatment of CIA.

Synthesis of novel E-2-chlorovinyltellurium compounds based on the stereospecific anti-addition of tellurium tetrachloride to acetylene

The reaction of tellurium tetrachloride with acetylene proceeds in a stereospecific anti-addition manner to afford the novel products E-2-chlorovinyltellurium trichloride and E,E-bis(2-chlorovinyl)tellurium dichloride. Reaction conditions for the selective preparation of each of these products were found. The latter was obtained in 90% yield in CHCl(3) under a pressure of acetylene of 10-15 atm, whereas the former product was formed in up to 72% yield in CCl(4) under a pressure of acetylene of 1-3 atm. Synthesis of the previously unknown E,E-bis(2-chlorovinyl) telluride, E,E-bis(2-chlorovinyl) ditelluride, E-2-chlorovinyl 1,2,2-trichloroethyl telluride and E,E-bis(2-chlorovinyl)-tellurium dibromide is described.

The organotelluride catalyst LAB027 prevents colon cancer growth in the mice

Organotellurides are newly described redox-catalyst molecules with original pro-oxidative properties. We have investigated the in vitro and in vivo antitumoral effects of the organotelluride catalyst LAB027 in a mouse model of colon cancer and determined its profile of toxicity in vivo. LAB027 induced an overproduction of H(2)O(2) by both human HT29 and murine CT26 colon cancer cell lines in vitro. This oxidative stress was associated with a decrease in proliferation and survival rates of the two cell lines. LAB027 triggered a caspase-independent, ROS-mediated cell death by necrosis associated with mitochondrial damages and autophagy. LAB027 also synergized with the cytotoxic drug oxaliplatin to augment its cytostatic and cytotoxic effects on colon cancer cell lines but not on normal fibroblasts. The opposite effects of LAB027 on tumor and on non-transformed cells were linked to differences in the modulation of reduced glutathione metabolism between the two types of cells. In mice grafted with CT26 tumor cells, LAB027 alone decreased tumor growth compared with untreated mice, and synergized with oxaliplatin to further decrease tumor development compared with mice treated with oxaliplatin alone. LAB027 an organotelluride catalyst compound synergized with oxaliplatin to prevent both in vitro and in vivo colon cancer cell proliferation while decreasing the in vivo toxicity of oxaliplatin. No in vivo adverse effect of LAB027 was observed in this model.

The anti-inflammatory effects of the tellurium redox modulating compound, AS101, are associated with regulation of NFkappaB signaling pathway and nitric oxide induction in macrophages

BACKGROUND

LPS-activated macrophages produce mediators which are involved in inflammation and tissue injury, and especially those associated with endotoxic shock. The non toxic tellurium compound ammonium tri-chloro(dioxoethylene-O,O'-)tellurate, AS101, has been recently shown to exert profound anti-inflammatory properties in animal models, associated with its Te(IV) redox chemistry. This study explores the anti-inflammatory properties of AS101 with respect to modulation of inflammatory cytokines production and regulation of iNOS transcription and expression in activated macrophages via targeting the NFkB complex.

RESULTS

AS101 decreased production of IL-6 and in parallel down-regulated LPS-induced iNOS expression and NO secretion by macrophages. AS101 reduced IkB phosphorylation and degradation, and reduced NFkB nuclear translocalization, albeit these effects were exerted at different kinetics. Chromatin immunoprecipitation assays showed that AS101 treatment attenuated p50-subunit ability to bind DNA at the NFkB consensus site in the iNOS promotor following LPS induction.

CONCLUSIONS

Besides AS101, the investigation of therapeutic activities of other tellurium(IV) compounds is scarce in the literature, although tellurium is the fourth most abundant trace element in the human body. Since IKK and NFkB may be regulated by thiol modifications, we may thus envisage, inview of our integrated results, that Te(IV) compounds, may have important roles in thiol redox biological activity in the human body and represent a new class of anti-inflammatory compounds.

Resolution of inflammation-related apoptotic processes by the synthetic tellurium compound, AS101 following liver injury

BACKGROUND/AIMS

Fulminant hepatic failure is a dangerous condition, which occurs when large parts of the liver become damaged beyond repair, and the liver is no longer able to function. This syndrome is induced by inflammatory processes, resulting in acute liver failure. Recently, the organotellurium compound, trichloro(dioxoethylene-O,O(')) tellurate (AS101), has been found by our group to be able to directly inhibit caspases, due to its Te(IV)-thiol chemistry. The aim of this study was to examine the potential of AS101 as an anti-inflammatory and anti-apoptotic compound in vitro and in vivo following liver injury.

METHODS

Propionibacterium acnes-primed LPS-induced liver injury was performed in Balb/c mice. ALT/AST, cytokines, caspase-1,-3 and-8 activities, and liver histology were assessed.

RESULTS

AS101 inhibited TNFalpha or anti-FAS-induced apoptotic processes in hepatocytes in vitro. A P. acnes+LPS in vivo liver injury model revealed lower serum ALT and AST and reduced necrosis and apoptosis in AS101-treated mice. IL-18 and IL-1beta reduced levels in AS101-treated mice were associated with caspase-1 activity inhibition. Our findings suggest IL-6, IL-17 and pSTAT3 as additional novel players in the pathogenicity of FHF. Inhibition of caspase-3, and-8 activities by AS101 treatment contributed to decreased hepatocyte death, resulting in increased survival.

CONCLUSIONS

We suggest that due to its interaction with key-target cysteine residues, AS101 mediates anti-inflammatory and anti-apoptotic effects in this FHF model, which may serve as a potent treatment for mitigation of hepatic damage.

A novel organotellurium compound (RT-01) as a new antileishmanial agent

Leishmaniasis is a neglected disease and endemic in developing countries. A lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. The aim of this study was to investigate the effect of RT-01, an organotellurane compound presenting biological activities, in 2 experimental systems against Leishmania amazonensis. The in vitro system consisted of promastigotes and amastigotes forms of the parasite, and the in vivo system consisted of L. amazonensis infected BALB/c mice, an extremely susceptible mouse strain. The compound proved to be toxic against promastigotes and amastigotes. The study also showed that treatment with RT-01 produces an effect similar to that treatment with the reference antimonial drug, Glucantime, in L. amazonensis infected mice. The best results were obtained following RT-01 intralesional administration (720 microg/kg/day); mice showed significant delay in the development of cutaneous lesions and decreased numbers of parasites obtained from the lesions. Significant differences in tissue pathology consisted mainly of no expressive accumulation of inflammatory cells and well-preserved structures in the skin tissue of RT-01-treated mice compared with expressive infiltration of infected cells replacing the skin tissue in lesions of untreated mice. These findings highlight the fact that the apparent potency of organotellurane compounds, together with their relatively simple structure, may represent a new avenue for the development of novel drugs to combat parasitic diseases.

Protective effect of the immunomodulator AS101 against cyclophosphamide-induced testicular damage in mice

BACKGROUND

Cyclophosphamide (Cy), a widely used anticancer drug, is associated with significant testicular damage and sterility. Co-administration of the immunomodulating compound AS101 during chemotherapy treatments was previously shown to protect organs against cytotoxic damage, without attenuating the drug's anticancer effect. In this animal study, we investigated the effect of AS101 on testicular damage, sperm DNA damage and infertility induced by Cy. Akt and glycogen synthase kinase-3beta (GSK-3beta) phosphorylation were investigated as a possible chemoprotective mechanism.

METHODS

Mature male mice, 10 in each group, were injected intraperitoneally with 200 mg/kg Cy once a week for 5 weeks, with or without concurrent treatment with 10 microg per mouse AS101 three times per week. Damage to testicular tubules and sperm production was determined, sperm chromatin damage was analyzed and fertility was gauged. Akt and GSK-3beta phosphorylation were evaluated.

RESULTS

Co-treatment with AS101 during the course of Cy administration significantly reduced the percentage of damaged seminiferous tubules (76.0 +/- 10.8% versus 40.3 +/- 2.6%), and reduced sperm DNA fragmentation (%DFI) from 44.7 +/- 1.0% to 25 +/- 6.5%. Co-treatment with AS101 also partially protected against the decrease in numbers of impregnated females and litter size. AS101 increased Akt and GSK-3beta phosphorylation.

CONCLUSIONS

Our results indicate that AS101 can significantly protect against Cy-induced testicular damage and sperm DNA damage, probably by acting through Akt/GSK-3beta phosphorylation.

Antitumour effects in mycosis fungoides of the immunomodulatory, tellurium-based compound, AS101

BACKGROUND

The immunomodulator AS101 [ammonium trichloro (dioxoethylene-O,O') tellurate], a nontoxic tellurium (IV) compound, has antitumoral effects which were demonstrated in several preclinical and clinical studies.

OBJECTIVES

To investigate the antitumour activity of AS101 on cutaneous T-cell lymphoma (CTCL), of which mycosis fungoides (MF) is the most frequent disease variant.

METHODS

We used a newly established mouse xenograft model for MF to test the effect of AS101 in vivo and analysed apoptosis induction in vitro.

RESULTS

When injected intratumorally, AS101 delayed tumour growth in a dose-dependent manner. In vitro, AS101 induced a dose-dependent G2/M arrest in the CTCL cell lines Hut78 and MyLa. Moreover, higher concentrations of AS101 induced apoptosis in MyLa cells. Programmed cell death was associated with the loss of mitochondrial transmembrane potential and activation of caspase 9 and caspase 3. AS101 also elevated intracellular reactive oxygen species (ROS) production; the antioxidant, Mn superoxide dismutase, significantly reduced the degree of apoptosis, suggesting that ROS play a key role in apoptosis induction.

CONCLUSIONS

These findings indicate that AS101 may be a promising antitumour drug for CTCL.

Prevention of chemotherapy-induced alopecia by the anti-death FNK protein

Many anticancer drugs attack rapidly dividing cells, including not only malignant cells but also hair follicle cells, and induce alopecia. Chemotherapy-induced alopecia (CIA) is an emotionally distressing side effect of cancer chemotherapy. There is currently no useful preventive therapy for CIA. We have previously constructed anti-death rFNK protein from rat Bcl-x(L) by site-directed mutagenesis to strengthen cytoprotective activity. When fused to the protein transduction domain (PTD) of HIV/Tat, the fusion protein PTD (TAT)-rFNK successfully entered cells from the outside in vitro and in vivo to exhibit anti-death activity against apoptosis and necrosis. Here, we show that topical application of FNK protected against CIA in a newborn rat model. The protective activity against hair-loss was observed in 30-1000 nM TAT-rFNK administrative groups in a dose-dependent manner. Furthermore, a human version of FNK (hFNK) fused to other PTD peptides exhibited a protective ability. These results suggest that PTD-FNK possesses protective activity against CIA and is not restricted to a sequence of PTD peptides or species of FNK. Thus, PTD-FNK represents potential to develop a useful method for preventing CIA in cancer patients.

Octa-O-bis-(R,R)-Tartarate Ditellurane (SAS)—a Novel Bioactive Organotellurium(IV) Compound: Synthesis, Characterization, and Protease Inhibitory Activity

Octa-O-bis-(R,R)-Tartarate Ditellurane (SAS) is a new Te(IV) compound, comprised of two tellurium atoms, each liganded by four oxygen atoms from two carboxylates and two alkoxides of two tartaric acids. Unlike many other Te(IV) compounds, SAS was highly stable in aqueous solution. It interacted with thiols to form an unstable Te(SR)(4) product. The product of the interaction of SAS with cysteine was isolated and characterized by mass spectroscopy and elemental analysis. SAS selectively inactivated cysteine proteases, but it did not inactivate other families of proteolytic enzymes. It displayed selectivity towards the cysteine protease cathepsin B, a human enzyme of pharmaceutical interest, with a second order rate constant k(i)/K(i)=5900 M(-1) s(-1).

Six cases of permanent alopecia after various conditioning regimens commonly used in hematopoietic stem cell transplantation

Alopecia, a side effect of chemotherapy, is usually temporary and reversible. Irreversible alopecia has been reported after high-dose chemotherapy (HDC) and hematopoietic stem cell transplantation (HSCT) especially related to BuCy containing conditioning regimens; however, the overall incidence is not known. We conducted a retrospective study to identify patients with chemotherapy-induced permanent alopecia after HSCT. We describe six such patients, two males and four females, among 760 patients transplanted between 1997 and 2004. Median age was 45 years (range, 37-65). There were three Caucasians and three African-Americans. Median follow-up was 30 months. Conditioning regimens included BuCy, Bu/Cy and etoposide (VP16) (one of these patients received second autograft after Cy and TBI) and CyVP16 and TBI. Our data show that permanent alopecia is a significant long-term side effect of HSCT and can be seen across the spectrum of diseases and transplant types and with non-busulfan containing regimens. We have observed that patients usually accept permanent alopecia as the price for the cure and therefore true incidence of permanent alopecia may be underestimated. Our findings may also have medico legal and psychosocial implications that need to be taken into consideration when consenting patients for HSCT.

Multifunctional tellurium molecule protects and restores dopaminergic neurons in Parkinson's disease models

In Parkinson's disease (PD) dopaminergic neurons in the substantia nigra (SN) become dysfunctional and many ultimately die. We report that the tellurium immunomodulating compound ammonium trichloro(dioxoethylene-O,O'-)tellurate (AS101) protects dopaminergic neurons and improves motor function in animal models of PD. It is effective when administered systemically or by direct infusion into the brain. Multifunctional activities of AS101 were identified in this study. These were mainly due to the peculiar Tellur(IV)-thiol chemistry of the compound, which enabled the compound to interact with cysteine residues on both inflammatory and apoptotic caspases, resulting in their inactivation. Conversely, its interaction with a key cysteine residue on p21(ras), led to its activation, an obligatory activity for AS101-induced neuronal differentiation. Furthermore, AS101 inhibited IL-10, resulting in up-regulation of GDNF in the SN. This was associated with activation of the neuroprotective kinases Akt and mitogen-activated protein kinases, and up-regulation of the antiapoptotic protein Bcl-2. Inhibition of caspase-1 and caspase-3 activities were associated with decreased neuronal death and inhibition of IL-1beta. We suggest that, because multiple mechanisms are involved in the dysfunction and death of neurons in PD, use of a multifunctional compound, exerting antiapoptotic, anti-inflammatory, and neurotrophic-inducing capabilities may be potentially efficacious for the treatment of PD.

Protection Against Chemotherapy-Induced Alopecia

PURPOSE

The goal is to provide an overview on the advances in protection against chemotherapy-induced alopecia (CIA).

MATERIALS AND METHODS

The four major parts of this review are (a) overview of the hair follicle biology, (b) characteristics of CIA, (c) state-of-the-art animal models of CIA, and (d) experimental approaches on protection against CIA.

RESULTS

The hair follicle represents an unintended target of cancer chemotherapy. CIA is a significant side effect that compromises the quality of life of patients. Overcoming CIA represents an area of unmet needs, especially for females and children. Significant progresses have been made in the last decade on the pathobiology of CIA. The pharmacological agents under evaluation include drug-specific antibodies, hair growth cycle modifiers, cytokines and growth factors, antioxidants, cell cycle or proliferation modifiers, and inhibitors of apoptosis. Their potential applications and limitations are discussed.

CONCLUSION

Multiple classes of agents with different action mechanisms have been evaluated in animal CIA models. Most of these protective agents have activity limited to a single chemotherapeutic agent. In comparison, calcitriol and cyclosporine A have broader spectrum of activity and can prevent against CIA by multiple chemotherapeutic agents. Among the three agents that have been evaluated in humans, AS101 and Minoxidil were able to reduce the severity or shorten the duration of CIA but could not prevent CIA.