A mutation threshold distinguishes the antitumorigenic effects of the mitochondrial gene MTND1, an oncojanus function

The oncogenic versus suppressor roles of mitochondrial genes have long been debated. Peculiar features of mitochondrial genetics such as hetero/homoplasmy and mutation threshold are seldom taken into account in this debate. Mitochondrial DNA (mtDNA) mutations generally have been claimed to be protumorigenic, but they are also hallmarks of mostly benign oncocytic tumors wherein they help reduce adaptation to hypoxia by destabilizing hypoxia-inducible factor-1α (HIF1α). To determine the influence of a disassembling mtDNA mutation and its hetero/homoplasmy on tumorigenic and metastatic potential, we injected mice with tumor cells harboring different loads of the gene MTND1 m.3571insC. Cell cultures obtained from tumor xenografts were then analyzed to correlate energetic competence, apoptosis, α-ketoglutarate (α-KG)/succinate (SA) ratio, and HIF1α stabilization with the mutation load. A threshold level for the antitumorigenic effect of MTND1 m.3571insC mutation was defined, above which tumor growth and invasiveness were reduced significantly. Notably, HIF1α destabilization and downregulation of HIF1α-dependent genes occurred in cells and tumors lacking complex I (CI), where there was an associated imbalance of α-KG/SA despite the presence of an actual hypoxic environment. These results strongly implicate mtDNA mutations as a cause of oncocytic transformation. Thus, the antitumorigenic and antimetastatic effects of high loads of MTND1 m.3571insC, following CI disassembly, define a novel threshold-regulated class of cancer genes. We suggest these genes be termed oncojanus genes to recognize their ability to contribute either oncogenic or suppressive functions in mitochondrial settings during tumorigenesis.     

Giant condyloma acuminatum of the anorectum: successful radical surgery with anal reconstruction

Buschke-L?wenstein tumor, or giant condyloma acuminatum, is a relatively uncommon lesion of the anus with aggressive local invasive behavior which may present as a large warty tumor of the genital region with expansive and destructive growth. Many sporadic reports have been published suggesting various therapeutic strategies. We report a case of Buschke-L?wenstein tumor treated with conservative surgery followed by reconstructive procedures without a loop colostomy     

Squamous cell carcinoma of the umbilicus: management of an unusual localization

We describe the case of a squamous cell carcinoma spreading to the skin and regional lymph nodes from the umbilicus. Bilateral inguinal lymphadenectomy and a session of electrochemotherapy with bleomycin 15 mg/m2 were performed. However, because of the development of new cutaneous nodules in the abdominopelvic region, we performed targeted palliative therapy with erlotinib 150 mg/day. Targeted adjuvant therapy was preferred to the use of a major cytotoxic agent because of the high risk of superinfection and heart failure. Erlotinib produced a partial clinical response with reduction of the number and size of the skin nodules. CT scan performed after 60 days of treatment did not show any new lesions. To our knowledge, this is the first report of an umbilical metastatic squamous cell carcinoma treated with modern targeted therapy. This therapeutic strategy can be considered a valid palliative option in the management of metastatic cutaneous nodules of this rare primary site.     

Professional oral hygiene as a therapeutic option for pediatric patients with plasma cell gingivitis: preliminary results of a prospective case series

Background: Plasma cell gingivitis (PCG) is a rare, benign inflammatory condition of unclear etiology with no definitive standard of care ever reported to our knowledge. The aim of this case series is to ascertain the clinical efficacy of professional oral hygiene and periodontal therapy in younger individuals with a histologically confirmed diagnosis of PCG. Methods: All patients received non‐surgical periodontal therapy, including oral hygiene instructions, and thorough supragingival scaling and polishing with the removal of all deposits and staining combined with the use of antimicrobials in a 9‐week cohort study. Clinical outcome variables were recorded at baseline and 4 weeks after the intervention and included, as periodontal parameters, full‐mouth plaque scores (FMPS), full‐mouth bleeding scores (FMBS), the clinical extension of gingival involvement, and patient‐related outcomes (visual analog score of pain). Results: A total of 11 patients (six males and five females; mean age: 11 ± 0.86 years) were recruited. Four weeks after finishing the oral hygiene and periodontal therapy protocol, a statistically significant reduction was observed for FMPS (P = 0.000), FMBS (P = 0.000), reported pain (P = 0.003) and clinical gingival involvement (P = 0.003). Conclusion: Standard, professional oral hygiene procedures and non‐surgical periodontal therapy including antimicrobials were associated with a marked improvement of clinical and patient‐related outcomes in pediatric cases of PCG.     

P2X7 receptor signaling contributes to tissue factor-dependent thrombosis in mice

Thrombosis is initiated by tissue factor (TF), a coagulation cofactor/receptor expressed in the vessel wall, on myeloid cells, and on microparticles (MPs) with variable procoagulant activity. However, the molecular pathways that generate prothrombotic TF in vivo are poorly defined. The oxidoreductase protein disulfide isomerase (PDI) is thought to be involved in the activation of TF. Here, we found that in mouse myeloid cells, ATP-triggered signaling through purinergic receptor P2X, ligand-gated ion channel, 7 (P2X7 receptor; encoded by P2rx7) induced activation (decryption) of TF procoagulant activity and promoted release of TF+ MPs from macrophages and SMCs. The generation of prothrombotic MPs required P2X7 receptor-dependent production of ROS leading to increased availability of solvent-accessible extracellular thiols. An antibody to PDI with antithrombotic activity in vivo attenuated the release of procoagulant MPs. In addition, P2rx7-/- mice were protected from TF-dependent FeCl3-induced carotid artery thrombosis. BM chimeras revealed that P2X7 receptor prothrombotic function was present in both hematopoietic and vessel wall compartments. In contrast, an alternative anti-PDI antibody showed activities consistent with cellular activation typically induced by P2X7 receptor signaling. This anti-PDI antibody restored TF-dependent thrombosis in P2rx7-/- mice. These data suggest that PDI regulates a critical P2X7 receptor-dependent signaling pathway that generates prothrombotic TF, defining a link between inflammation and thrombosis with potential implications for antithrombotic therapy.     

Evaluation of a stable gonadotropin-releasing hormone analog in mice for the treatment of endocrine disorders and prostate cancer

Gonadotropin-releasing hormone (GnRH) receptor agonists have wide clinical applications including the treatment of prostate cancer and endocrine disorders. However, such agonists are characterized by poor pharmacokinetic properties, often requiring repeated administration or special formulations. Therefore, the development of novel peptide analogs with enhanced in vivo stability could potentially provide therapeutic alternatives. The pharmacological evaluation of a bioactive peptide [Des-Gly1?,Tyr?(OMe),D-Leu?,Aze-NHEt?]GnRH, analog 1, is presented herein and compared with leuprolide. Peptide stability was evaluated using mouse kidney membrane preparations, followed by a liquid chromatography-tandem mass spectrometry-based approach that afforded identification and quantification of its major metabolites. The analog was significantly more stable in vitro in comparison with leuprolide. In vitro and in vivo stability results correlated well, encouraging us to develop a clinically relevant pharmacokinetic mouse model, which facilitated efficacy measurements using testosterone as a biomarker. Analog 1, an agonist of the GnRH receptor with a binding affinity in the nanomolar range, caused testosterone release in mice that was acutely dose-dependent, an effect blocked by the GnRH receptor antagonist cetrorelix. Repeated dosing studies in mice demonstrated that analog 1 was well tolerated and had potency similar to that of leuprolide, based on plasma and testis testosterone reduction and histopathological findings. Analog 1 also shared with leuprolide similar significant antiproliferative activity on androgen-dependent prostate cancer (LNCaP) cells. On the basis of pharmacokinetic advantages, we expect that analog 1 or analogs based on this new design will be therapeutically advantageous for the treatment of cancer and endocrine disorders.     

Evaluation, synthesis and characterization of tacrolimus impurities

Tacrolimus is an immunosuppressant macrolactam of fermentative origin. By means of HPLC, LC-MS and NMR analyses, coupled with the reference standard synthesis, the main impurities of tacrolimus bulk drug samples were identified and their chemical-physical properties reported. Known ascomycin and tautomers I and II were detected. The correct relative retention time HPLC value of 39,40-dihydro tacrolimus was established. The not described 23,24-anhydro derivative was detected and completely characterized. A full characterization of ascomycin and 39,40-dihydro tacrolimus was also reported.     

Pharmacological actions of statins: a critical appraisal in the management of cancer

Statins, among the most commonly prescribed drugs worldwide, are cholesterol-lowering agents used to manage and prevent cardiovascular and coronary heart diseases. Recently, a multifaceted action in different physiological and pathological conditions has been also proposed for statins, beyond anti-inflammation and neuroprotection. Statins have been shown to act through cholesterol-dependent and -independent mechanisms and are able to affect several tissue functions and modulate specific signal transduction pathways that could account for statin pleiotropic effects. Typically, statins are prescribed in middle-aged or elderly patients in a therapeutic regimen covering a long life span during which metabolic processes, aging, and concomitant novel diseases, including cancer, could occur. In this context, safety, toxicity, interaction with other drugs, and the state of health have to be taken into account in subjects treated with statins. Some evidence has shown a dichotomous effect of statins with either cancer-inhibiting or -promoting effects. To date, clinical trials failed to demonstrate a reduced cancer occurrence in statin users and no sufficient data are available to define the long-term effects of statin use over a period of 10 years. Moreover, results from clinical trials performed to evaluate the therapeutic efficacy of statins in cancer did not suggest statin use as chemotherapeutic or adjuvant agents. Here, we reviewed the pharmacology of the statins, providing a comprehensive update of the current knowledge of their effects on tissues, biological processes, and pathological conditions, and we dissected the disappointing evidence on the possible future use of statin-based drugs in cancer therapy.     

Long-term administration with levonorgestrel decreases allopregnanolone levels and alters GABA(A) receptor subunit expression and anxiety-like behavior

Fluctuations in the concentrations of the neuroactive steroid allopregnanolone are thought to influence γ-amino-butyric acid type A (GABA_A) receptor gene expression and function. Long-term treatment with ethinyl estradiol (EE) plus levonorgestrel (LNG), two of the most widely used steroids in the hormonal contraceptive pill, decreases allopregnanolone levels in rat cerebral cortex and plasma, alters GABA_A receptor expression and induces anxiety-like behavior. We evaluated which component of the hormonal contraceptive pill is responsible for the aforementioned changes. Female rats were injected subcutaneously (s.c.) with EE (0.030 mg) or LNG (0.125 mg) once a day for 4 weeks. Compared to the respective vehicle-treated control groups, EE decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 76, 72 and 33%, respectively and hippocampal levels by 52, 56 and 50%, respectively. Likewise, LNG decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 75, 68 and 33%, respectively, and hippocampal levels by 55, 65 and 60%, respectively. Administration of LNG, but not EE, increased the abundance of the γ2 subunit peptide in cerebral cortex and hippocampus by 38 and 59%, respectively. Further, LNG, but not EE, decreased the time spent and the number of entries into the open arms of the elevated plus maze by 56 and 43%, respectively, an index of anxiety-like behavior. These results suggest that alterations in GABA_A receptor subunit expression and anxiety-like behavior induced by long-term treatment with combined EE/LNG appear to be caused by LNG. Given that both EE and LNG decrease allopregnanolone levels in a similar manner, these results further suggest that changes in allopregnanolone levels are not associated with GABA_A receptor expression.