Photobiomodulation therapy: management of mucosal necrosis of the oropharynx in previously treated head and neck cancer patients.

Necrosis of the oral mucosa following head and neck cancer radiation therapy presents considerable clinical management challenges. We report three cases of symptomatic persisting oral ulcerations where the addition of photobiomodulation therapy resulted in a rapid resolution of the oral lesions and in patient symptoms. These cases suggest that photobiomodulation may represent an adjunct to care of these difficult to manage complications in oncology.

Amelioration of sepsis by TIE2 activation-induced vascular protection.

Protection of endothelial integrity has been recognized as a frontline approach to alleviating sepsis progression, yet no effective agent for preserving endothelial integrity is available. Using an unusual anti-angiopoietin 2 (ANG2) antibody, ABTAA (ANG2-binding and TIE2-activating antibody), we show that activation of the endothelial receptor TIE2 protects the vasculature from septic damage and provides survival benefit in three sepsis mouse models. Upon binding to ANG2, ABTAA triggers clustering of ANG2, assembling an ABTAA/ANG2 complex that can subsequently bind and activate TIE2. Compared with a conventional ANG2-blocking antibody, ABTAA was highly effective in augmenting survival from sepsis by strengthening the endothelial glycocalyx, reducing cytokine storms, vascular leakage, and rarefaction, and mitigating organ damage. Together, our data advance the role of TIE2 activation in ameliorating sepsis progression and open a potential therapeutic avenue for sepsis to address the lack of sepsis-specific treatment.

Protection from cyanide-induced brain injury by the Nrf2 transcriptional activator carnosic acid.

Cyanide is a life-threatening, bioterrorist agent, preventing cellular respiration by inhibiting cytochrome c oxidase, resulting in cardiopulmonary failure, hypoxic brain injury, and death within minutes. However, even after treatment with various antidotes to protect cytochrome oxidase, cyanide intoxication in humans can induce a delayed-onset neurological syndrome that includes symptoms of Parkinsonism. Additional mechanisms are thought to underlie cyanide-induced neuronal damage, including generation of reactive oxygen species. This may account for the fact that antioxidants prevent some aspects of cyanide-induced neuronal damage. Here, as a potential preemptive countermeasure against a bioterrorist attack with cyanide, we tested the CNS protective effect of carnosic acid (CA), a pro-electrophilic compound found in the herb rosemary. CA crosses the blood-brain barrier to up-regulate endogenous antioxidant enzymes via activation of the Nrf2 transcriptional pathway. We demonstrate that CA exerts neuroprotective effects on cyanide-induced brain damage in cultured rodent and human-induced pluripotent stem cell-derived neurons in vitro, and in vivo in various brain areas of a non-Swiss albino mouse model of cyanide poisoning that simulates damage observed in the human brain. Cyanide, a potential bioterrorist agent, can produce a chronic delayed-onset neurological syndrome that includes symptoms of Parkinsonism. Here, cyanide poisoning treated with the proelectrophillic compound carnosic acid, results in reduced neuronal cell death in both in vitro and in vivo models through activation of the Nrf2/ARE transcriptional pathway. Carnosic acid is therefore a potential treatment for the toxic central nervous system (CNS) effects of cyanide poisoning. ARE, antioxidant responsive element; Nrf2 (NFE2L2, Nuclear factor (erythroid-derived 2)-like 2).

Gln-362 of angiopoietin-2 mediates migration of tumor and endothelial cells through association with α5ß1 integrin.

Angiopoietin-2 (Ang-2) not only regulates angiogenesis by binding to its well known receptor Tie2 on endothelial cells but also controls sprouting of Tie2-negative angiogenic endothelial cells and invasion of Tie2-negative non-endothelial cells by binding to integrins. However, the molecular mechanism of the Ang-2/integrin association has been unclear. In this study, we found that the Gln-362 residue of Ang-2 was essential for binding to α5ß1 integrin. A Q362E Ang-2 mutant, which still bound to Tie2, failed to associate with α5ß1 integrin and was unable to activate the integrin downstream signaling of focal adhesion kinase. In addition, unlike wild-type Ang-2, the Q362E Ang-2 mutant was defective in mediating invasion of Tie2-negative glioma or Tie2-positive endothelial cells. Furthermore, the tailpiece domain of the α5 subunit in α5ß1 integrin was critical for binding to Ang-2. Taken together, these results provide a novel insight into the mechanism of integrin regulation by Ang-2, which contributes to tumor invasion and endothelial cell migration in a Tie2-independent manner.

Protein grafting of p53TAD onto a leucine zipper scaffold generates a potent HDM dual inhibitor.

Reactivation of the p53 pathway by a potential therapeutic antagonist, which inhibits HDM2 and HDMX, is an attractive strategy for drug development in oncology. Developing blockers towards conserved hydrophobic pockets of both HDMs has mainly focused on small synthetic compounds; however, this approach has proved challenging. Here we describe an approach to generate a potent HDM dual inhibitor, p53LZ2, by rational protein grafting of the p53 transactivation domain onto a homodimeric leucine zipper. p53LZ2 shows tight binding affinity to both HDMs compared with wild-type p53 in vitro. X-ray crystallographic, comparative modelling and small-angle X-ray scattering studies of p53LZ2-HDM complexes show butterfly-shaped structures. A cell-permeable TAT-p53LZ2 effectively inhibits the cancer cell growth in wild-type but not mutant p53 by arresting cell cycle and inducing apoptosis in vitro. Thus, p53LZ2, designed by rational grafting, shows a potential therapeutic approach against cancer.

USP8 modulates ubiquitination of LRIG1 for Met degradation.

The Met receptor tyrosine kinase is an attractive target for cancer therapy as it promotes invasive tumor growth. SAIT301 is a novel anti-Met antibody, which induces LRIG1-mediated Met degradation and inhibits tumor growth. However, detailed downstream mechanism by which LRIG1 mediates target protein down-regulation is unknown. In the present study, we discovered that SAIT301 induces ubiquitination of LRIG1, which in turn promotes recruitment of Met and LRIG1 complex to the lysosome through its interaction with Hrs, resulting in concomitant degradation of both LRIG1 and Met. We also identified USP8 as a LRIG1-specific deubiquitinating enzyme, reporting the interaction between USP8 and LRIG1 for the first time. SAIT301 triggers degradation of LRIG1 by inhibiting the interaction of LRIG1 and USP8, which regulates ubiquitin modification and stability of LRIG1. In summary, SAIT301 employs ubiquitination of LRIG1 for its highly effective Met degradation. This unique feature of SAIT301 enables it to function as a fully antagonistic antibody without Met activation. We found that USP8 is involved in deubiquitination of LRIG1, influencing the efficiency of Met degradation. The relation of Met, LRIG1 and USP8 strongly supports the potential clinical benefit of a combination treatment of a USP8 inhibitor and a Met inhibitor, such as SAIT301.

A new anti-c-Met antibody selected by a mechanism-based dual-screening method: therapeutic potential in cancer.

c-Met, the high affinity receptor for hepatocyte growth factor (HGF), is one of the most frequently activated tyrosine kinases in many human cancers and a target for cancer therapy. However, inhibitory targeting of c-Met with antibodies has proven difficult, because most antibodies have intrinsic agonist activity. Therefore, the strategy for reducing the agonism is critical for successful development of cancer therapies based on anti-c-Met antibodies. Here we developed a mechanism-based assay method for rapid screening of anti-c-Met antibodies, involving the determination of Akt phosphorylation and c-Met degradation for agonism and efficacy, respectively. Using the method, we identified an antibody, F46, that binds to human c-Met with high affinity (Kd = 2.56 nM) and specificity, and induces the degradation of c-Met in multiple cancer cells (including MKN45, a gastric cancer cell line) with minimal activation of c-Met signaling. F46 induced c-Met internalization in both HGF-dependent and HGF-independent cells, suggesting that the degradation of c-Met results from antibody-mediated receptor internalization. Furthermore, F46 competed with HGF for binding to c-Met, resulting in the inhibition of both HGF-mediated invasion and angiogenesis. Consistently, F46 inhibited the proliferation of MKN45 cells, in which c-Met is constitutively activated in an HGF-independent manner. Xenograft analysis revealed that F46 markedly inhibits the growth of subcutaneously implanted gastric and lung tumors. These results indicate that F46, identified by a novel mechanism-based assay, induces c-Met degradation with minimal agonism, implicating a potential role of F46 in therapy of human cancers.

MET signaling regulates glioblastoma stem cells.

Glioblastomas multiforme (GBM) contain highly tumorigenic, self-renewing populations of stem/initiating cells [glioblastoma stem cells (GSC)] that contribute to tumor propagation and treatment resistance. However, our knowledge of the specific signaling pathways that regulate GSCs is limited. The MET tyrosine kinase is known to stimulate the survival, proliferation, and invasion of various cancers including GBM. Here, we identified a distinct fraction of cells expressing a high level of MET in human primary GBM specimens that were preferentially localized in perivascular regions of human GBM biopsy tissues and were found to be highly clonogenic, tumorigenic, and resistant to radiation. Inhibition of MET signaling in GSCs disrupted tumor growth and invasiveness both in vitro and in vivo, suggesting that MET activation is required for GSCs. Together, our findings indicate that MET activation in GBM is a functional requisite for the cancer stem cell phenotype and a promising therapeutic target.

Health care-related economic burden of the polycystic ovary syndrome during the reproductive life span.

CONTEXT: The polycystic ovary syndrome (PCOS) is the most common endocrine abnormality of reproductive-aged women today, affecting approximately 6.6% of unselected reproductive-aged women (approximately 4 million women in the United States) (1990 National Institutes of Health criteria), and potentially represents a significant financial burden to our health care. OBJECTIVE: The objective of the study was to define, using current definitions and prevalence or incidence data, the minimal economic burden that PCOS in reproductive-aged women represents for the United States. DESIGN: The study design was a literature review. SETTING: The study was conducted at a tertiary care center. PATIENTS OR OTHER PARTICIPANTS: There were no patients or other participants. INTERVENTION(S): We performed a systematic review of the published medical literature to identify studies evaluating epidemiology of reproductive-age PCOS and its clinical consequences and costs. We tied general societal cost data for the different health consequences to reproductive-age PCOS costs, using prevalence data. MAIN OUTCOME MEASURE(S): The main measure in the study was total health care-related economic costs. RESULTS: We estimated the mean annual cost of the initial evaluation to be dollar 93 million (2.1% of total costs), that of hormonally treating menstrual dysfunction/abnormal uterine bleeding to be dollar 1.35 billion (31.0% of total), that of providing infertility care to be dollar 533 million (12.2% of total), that of PCOS-associated diabetes to be dollar 1.77 billion (40.5% of total), and that of treating hirsutism to be dollar 622 million (14.2% of total). CONCLUSIONS: The total cost of evaluating and providing care to reproductive-aged PCOS women in the United States is dollar 4.36 billion. Because the cost of the diagnostic evaluation accounted for a relatively minor part of the total costs (approximately 2%), more widespread and liberal screening for the disorder appears be a cost-effective strategy, leading to earlier diagnosis and intervention and possibly the amelioration and prevention of serious sequelae.