ARTS-based anticancer therapy: taking aim at cancer stem cells

Apoptosis related protein in TGF-β signaling pathway (ARTS/septin 4 isoform 2) hereforth referred to as ARTS, was originally found to promote apoptosis induced by TGF-β, but later was shown to promote apoptosis induced by a wide variety of apoptotic stimuli. In vivo and in vitro studies revealed that ARTS-induced apoptosis is mainly executed through direct binding and antagonizing XIAP. High levels of XIAP are found in many types of cancers and often correlate with poor prognosis. ARTS was shown to function as a tumor-suppressor protein in human patients and mouse-tumor models. In particular, Septin 4/ARTS-deficient mice have increased tumor susceptibility and contain increased numbers of stem cells (SCs) and progenitor cells, apparently owing to their resistance towards apoptosis. Based on these results we propose that loss of proapoptotic ARTS may act as the 'first hit' initiating tumorigenesis in two distinct ways. First, loss of ARTS-mediated apoptosis leads to increased numbers of normal SCs. Elevated numbers of normal SCs may lead to increased cancer risk due to higher numbers of cellular targets available for transforming mutations. Second, after these SCs acquire additional transforming mutations and become cancer SC (CSCs), they are more likely to survive in the absence of ARTS owing to increased resistance toward apoptosis. A combination of these two mechanisms, over time, is expected to significantly increase tumor risk. Because CSCs appear to share phenotypic markers with normal SCs, targeting the signaling pathways that affect normal SC development and maintenance can serve as a useful approach towards true eradication of cancer. In this article we describe the role of ARTS in apoptosis and cancer, with focus on its potential role as a CSC marker and as a potential target for anticancer and anti-CSC therapy.     

Application of pulsed-field gel electrophoresis to identify the source of bacterial contamination of peripheral blood progenitor cell products

BACKGROUND: Positive microbial cultures of peripheral blood progenitor cell (PBPC) products, although estimated to be low, are serious events in the manufacture of hematopoietic progenitor cell (HPC) products that warrant a thorough investigation to determine the contamination source. STUDY DESIGN AND METHODS: Two patients underwent autologous PBPC collection. The first patient was admitted before the collection and was febrile intermittently throughout hospitalization. The second patient spiked a low‐grade fever by the end of the procedure. The HPC products from each patient were cultured during processing and before infusion. Blood cultures were drawn during febrile episodes and before transplant. Bacterial identification and antimicrobial susceptibilities were performed on all positive cultures. All strains were typed using pulsed‐field gel electrophoresis (PFGE) to determine their relatedness. RESULTS: The blood cultures from both patients and their corresponding HPC products grew Staphylococcus epidermidis. The PFGE pattern of the S. epidermidis recovered from each patient blood was indistinguishable from the one recovered from the corresponding HPC product. The gel pattern of the strains recovered from the first patient differed by four bands from the one recovered from the second. For each patient, the antibiotic susceptibility patterns of the blood cultures and the HPC products were identical. Infusion of the contaminated HPC had no adverse event, and the patients engrafted successfully. CONCLUSION: By use of PFGE technology, the contamination source of PBPC products was identified. It is concluded that the contamination resulted from intermittent bacteremia in the donors and was not introduced during laboratory manufacturing.     

Laparoscopic Sleeve Gastrectomy—Volume and Pressure Assessment

BACKGROUND: Aiming to clarify the mechanism of weight loss after the restrictive bariatric procedure of sleeve gastrectomy (LSG), the volumes and pressures of the stomach, of the removed part, and of the remaining sleeve were measured in 20 morbidly obese patients. METHODS: The technique used consisted of occlusion of the pylorus with a laparoscopic clamp and of the gastroesophageal junction with a special orogastric tube connected to a manometer. Instillation of methylene-blue-colored saline via the tube was continued until the intraluminal pressure increased sharply, or the inflated stomach reached 2,000 cc. After recording of measurements, LSG was performed. RESULTS: Mean volume of the entire stomach was 1,553 cc (600-2,000 cc) and that of the sleeve 129 cc (90-220 cc), i.e., 10% (4-17%) and that of the removed stomach was 795 cc (400-1,500 cc). The mean basal intragastric pressure of the whole stomach after insufflations of the abdominal cavity with CO(2) to 15 mmHg was 19 mmHg (11-26 mmHg); after occlusion and filling with saline it was 34 mmHg (21-45 mmHg). In the sleeved stomach, mean basal pressure was similar 18 mmHg (6-28 mmHg); when filled with saline, pressure rose to 43 mmHg (32-58 mmHg). The removed stomach had a mean pressure of 26 mmHg (12-47 mmHg). There were no postoperative complications and no mortality. CONCLUSIONS: The notably higher pressure in the sleeve, reflecting its markedly lesser distensibility compared to that of the whole stomach and of the removed fundus, indicates that this may be an important element in the mechanism of weight loss.     

Association of mild to moderate kidney dysfunction and coronary calcification

Coronary artery calcification (CAC) is prevalent and predicts mortality among patients with ESRD, but whether less severe kidney dysfunction is associated with CAC is uncertain. To address this question, 6749 participants of the Multi-Ethnic Study of Atherosclerosis, who were middle-aged and without known cardiovascular disease, were evaluated. Renal function was categorized by cystatin C quartiles and estimated GFR (eGFR; < to >60 ml/min per 1.73 m(2)), and CAC was evaluated by computed tomography (CT). Fifty percent of participants had CAC, mean cystatin C was 0.90 mg/L, and 10% had eGFR <60 ml/min per 1.73 m(2). In unadjusted analysis, kidney dysfunction by either measure was strongly associated with CAC; however, the associations were lost after adjustment for age, gender, race, hypertension, and IL-6 (relative risk 1.04 [95% confidence interval 0.97 to 1.11] for the highest cystatin C quartile compared with the lowest, and relative risk 1.03 [95% confidence interval 0.98 to 1.08] for eGFR below compared with above 60 m/min per 1.73 m(2)). Similarly, neither higher cystatin C nor eGFR <60 was associated with severity of CAC. These results suggest that a higher burden of CAC is unlikely to explain the association between mild to moderate kidney dysfunction and cardiovascular mortality.     

Molecular impacts of rapamycin-based drug combinations: combining rapamycin with gemcitabine or imatinib mesylate (Gleevec) in a human leiomyosarcoma model

Drug combinations may provide a therapeutic benefit in treating cancer patients. However when considering a drug combination, it is important to assess how the molecular impact of the combination relates to the effects manifested by each drug alone and whether or not it varies depending on the tumor type. In this study, we have analyzed the molecular impact on a human leiomyosarcoma cell line (SK-LMS-1) of a combination consisting of the mTOR inhibitor rapamycin and either the anti-metabolite drug gemcitabine (Gemzar) or the protein tyrosine kinase inhibitor imatinib mesylate (Gleevec, STI571). We show that imatinib mesylate depolarizes the mitochondrial membrane potential (DeltaPhim) and inhibits protein tyrosine phosphorylation, but displays only minor effects on cell proliferation when added alone or in combin-ation with rapamycin. Gemcitabine or rapamycin, when added alone, inhibit protein tyrosine phosphorylation as well as phosphorylation of the MAP kinases ERK1/2. Both drugs also affect the cell cycle, arresting the cells at the S or G1 phase respectively. Rapamycin elevates significantly DeltaPhim but produces only a moderate effect on cell growth. Gemcitabine inhibits considerably cell growth but exerts no effect on DeltaPhim. Combining gemcitabine and rapamycin produces a major effect on the cell cycle, elevates the DeltaPhim even further and maintains the molecular impacts exerted by each single drug. Therefore, consistent with our clinical observation, these results suggest that combining gemcitabine and rapamycin may be beneficial in treating leiomyosarcoma patients.     

Alginate scaffold for organ culture of cryopreserved-thawed human ovarian cortical follicles

Purpose  

To compare macroporous alginate scaffolds with Matrigel for culturing frozen-thawed human primordial follicles in organ culture.     

Invited commentary: a single nucleotide polymorphism in BMP15 is associated with high response to controlled ovarian hyperstimulation

A report has been published which shows a connection between single nucleotide polymorphisms (SNP) in the bone morphogenetic protein 15 (BMP15) gene and ovarian hyperstimulation syndrome (OHSS) in women, similar to reported effects of heterozygous BMP15 point mutations in sheep. The report also describes the near-significant presence of another BMP15 gene SNP correlated with a low response to ovarian stimulation. Previous studies associated two SNP with anovulation or infertility in women with polycystic ovary syndrome, and heterozygosity for another BMP15 SNP resulted in ovarian dysgenesis and hypergonadotrophic failure. In sheep, homozygous point mutations or immunization against BMP15 led to follicular developmental arrest, ovarian dysgenesis and streak ovaries. In mammalian (including human) ovaries BMP15 and its three receptors were shown to be expressed from primary or primordial follicular stages, suggesting that BMP15 might also be involved in activating primordial follicles, and could possibly serve as a marker of follicular reserve. BMP15 also inhibited follicle stimulating hormone receptor expression, was associated with cumulus expansion and its high follicular-fluid concentration was correlated with improved oocyte and embryo quality. Thus, BMP15 seems to be an important regulator of ovarian function. Further studies are needed to clarify its roles in human female fertility.