Proteomics analysis of melanoma metastases: association between S100A13 expression and chemotherapy resistance

Background:

Disseminated cutaneous malignant melanoma (CMM) is commonly unresponsive to standard chemotherapies, and there are as yet no predictive markers of therapy response.

Methods:

In the present study we collected fresh-frozen pretreatment lymph-node metastasis samples (n=14) from melanoma patients with differential response to dacarbazine (DTIC) or temozolomide (TMZ) chemotherapy, to identify proteins with an impact on treatment response. We performed quantitative protein profiling using tandem mass spectrometry and compared the proteome differences between responders (R) and non-responders (NR), matched for age, gender and histopathological type of CMM.

Results:

Biological pathway analyses showed several signalling pathways differing between R vs NR, including Rho signalling. Gene expression profiling data was available for a subset of the samples, and the results were compared with the proteomics data. Four proteins with differential expression between R and NR were selected for technical validation by immunoblotting (ISYNA1, F13A1, CSTB and S100A13), and CSTB and S100A13 were further validated on a larger sample set by immunohistochemistry (n=48). The calcium binding protein S100A13 was found to be significantly overexpressed in NR compared with R in all analyses performed.

Conclusions:

Our results suggest that S100A13 is involved in CMM resistance to DTIC/TMZ.     

Immune checkpoints in targeted-immunotherapy of pancreatic cancer: New hope for clinical development

Immunotherapy has been recently considered as a promising alternative for cancer treatment. Indeed, targeting of immune checkpoint (ICP) strategies have shown significant success in human malignancies. However, despite remarkable success of cancer immunotherapy in pancreatic cancer (PCa), many of the developed immunotherapy methods show poor therapeutic outcomes in PCa with no or few effective treatment options thus far. In this process, immunosuppression in the tumor microenvironment (TME) is found to be the main obstacle to the effectiveness of antitumor immune response induced by an immunotherapy method. In this paper, the latest findings on the ICPs, which mediate immunosuppression in the TME have been reviewed. In addition, different approaches for targeting ICPs in the TME of PCa have been discussed. This review has also synopsized the cutting-edge advances in the latest studies to clinical applications of ICP-targeted therapy in PCa.KEY WORDS: Immune checkpoint, Pancreatic cancer, Tumor microenvironment, Immunotherapy, Clinical development     

An analytical study of Doppler ultrasound systems

The past theoretical contributions in Doppler ultrasonic imaging have borrowed heavily from the electromagnetic case. In these contributions, most points of departure between the ultrasonic and electromagnetic cases were taken care of by heuristic incorporation of factors in the derived formulas. A theory is presented that is more complete in the sense that it specifically accounts for the diffracted fields of the transducer aperture (assumed to be a source of a Gaussian focussed beam), the interaction of these fields with the scattering sites, and the interaction of the transducer aperture with the back scattered fields. The theoretical formulation was used to perform a series of computer simulation studies on Doppler ultrasound. The control afforded by the theory over different parameters of the system has allowed us to study the effect of the different signal bandwidths, tissue attenuation constants, and the role of transducer design in the ultrasound Doppler systems.     

Reliability of polymerase chain reaction in the detection of human immunodeficiency virus infection in children.

During a 3-year period we followed 128 human immunodeficiency virus (HIV) antibody-positive children ages 6 days to 11 years clinically and with an HIV diagnostic panel consisting of antibody (by enzyme-linked immunosorbent assay and confirmed by indirect fluorescence assay or Western blot), p24 antigen detection, HIV isolation from peripheral blood culture and molecular detection of HIV nucleic acids by polymerase chain reaction (PCR). The PCR procedure included 30 cycles of amplification using two separate gag primer pairs (SK38/39 and SK101/145), followed by detection with probes to areas amplified (SK19 and SK102). Results of PCR were available within 48 hours and were sensitive (97%) and specific (100%). PCR should be obtained on all children exposed perinatally, and aggressive management should be undertaken for those found to be positive.     

Development of resistance to serotonin‐induced itch in bile duct ligated mice

Cholestatic itch can be severe and significantly impair the quality of life of patients. The serotonin system is implicated in cholestatic itch; however, the pruritogenic properties of serotonin have not been evaluated in cholestatic mice. Here, we investigated the serotonin‐induced itch in cholestatic mice which was induced by bile duct ligation (BDL). Serotonin, sertraline or saline were administered intradermally to the rostral back area in BDL and sham operated (SHAM) mice, and the scratching behaviour was videotaped for 1 hour. Bile duct ligated mice had significantly increased scratching responses to saline injection on the seventh day after surgery. Additionally, serotonin or sertraline significantly induced scratching behaviour in BDL mice compared to saline at day 7 after surgery, while it did not induce itch at day 5. The scratching behaviour induced by serotonin or sertraline was significantly less in BDL mice compared to SHAM mice. Likewise, the locomotor activity of BDL or SHAM mice was not significantly different from unoperated (UNOP) mice on the fifth and seventh day, suggesting that the scratching behaviour was not affected by motor dysfunctions. Our data suggest that despite the potentiation of evoked itch, a resistance to serotonin‐induced itch is developed in cholestatic mice.     

Characterization of an orthovoltage biological irradiator used for radiobiological research

Orthovoltage irradiators are routinely used to irradiate specimens and small animals in biological research. There are several reports on the characteristics of these units for small field irradiations. However, there is limited knowledge about use of these units for large fields, which are essential for emerging large-field irregular shape irradiations, namely total marrow irradiation used as a conditioning regimen for hematological malignancies. This work describes characterization of a self-contained Orthovoltage biological irradiator for large fields using measurements and Monte Carlo simulations that could be used to compute the dose for in vivo or in vitro studies for large-field irradiation using this or a similar unit. Percentage depth dose, profiles, scatter factors, and half-value layers were measured and analyzed. A Monte Carlo model of the unit was created and used to generate depth dose and profiles, as well as scatter factors. An ion chamber array was also used for profile measurements of flatness and symmetry. The output was determined according to AAPM Task Group 61 guidelines. The depth dose measurements compare well with published data for similar beams. The Monte Carlo–generated depth dose and profiles match our measured doses to within 2%. Scatter factor measurements indicate gradual variation of these factors with field size. Dose rate measured by placing the ion chamber atop the unit''s steel plate or solid water indicate enhanced readings of 5 to 28% compared with those measured in air. The stability of output over a 5-year period is within 2% of the 5-year average.     

Nitric oxide effects on myocardial function and force-interval relations: regulation of twitch duration

As the precise role of nitric oxide (NO) as a modulator of myocardial contraction and the force-interval relationship remains unclear, the objective of this study was to examine the effect of the NO donor S-nitroso-N-acetyl-penicillamine (SNAP) on baseline myocardial contraction, and the impact of both SNAP and the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) on the force interval relation. Studies were performed using isolated rat papillary muscles. In the presence of baseline NOS blockade, nanomolar to micromolar concentrations of SNAP exerted a modest positive inotropic effect with a small but significant increase in twitch isometric tension (P<0.007). Nanomolar concentrations of SNAP also reduced overall twitch duration (P<0.007). These effects were not seen in control experiments using N-acetyl-penicillamine instead of SNAP. The force-frequency response (FFR) and post-rest contractile potentiation, mechanical correlates of sarcoplasmic reticulum (SR) Ca(2+)handling, were also examined. Neither L-NAME nor SNAP had any effect on post-rest potentiation following rest intervals as long as 6 min, or on the negative FFR at stimulation frequencies between 0.3 to 1.7 Hz. However, L-NAME significantly blunted the net reduction in twitch duration between 0.3 Hz and 1.7 Hz compared to control (P=0.006), an effect reversed by 100 n m SNAP. These results indicate that low concentrations of NO can modulate myocardial function by influencing myocardial inotropy and the time course of myofilament interaction, but do not impact significantly on the force-interval relation and, by inference, SR Ca(2+)handling. Moreover, modulation of twitch duration occurs over a range of stimulation frequencies, suggesting a mechanistic role for NO in the changes in contraction and relaxation time intervals seen during changes in heart rate.     

Differentiation of human endometrial stem cells into urothelial cells on a three‐dimensional nanofibrous silk–collagen scaffold: an autologous cell resource for reconstruction of the urinary bladder wall

Reconstruction of the bladder wall via in vitro differentiated stem cells on an appropriate scaffold could be used in such conditions as cancer and neurogenic urinary bladder. This study aimed to examine the potential of human endometrial stem cells (EnSCs) to form urinary bladder epithelial cells (urothelium) on nanofibrous silk–collagen scaffolds, for construction of the urinary bladder wall. After passage 4, EnSCs were induced by keratinocyte growth factor (KGF) and epidermal growth factor (EGF) and seeded on electrospun collagen‐V, silk and silk–collagen nanofibres. Later we tested urothelium‐specific genes and proteins (uroplakin‐Ia, uroplakin‐Ib, uroplakin‐II, uroplakin‐III and cytokeratin 20) by immunocytochemistry, RT–PCR and western blot analyses. Scanning electron microscopy (SEM) and histology were used to detect cell–matrix interactions. DMEM/F12 supplemented by KGF and EGF induced EnSCs to express urothelial cell‐specific genes and proteins. Either collagen, silk or silk–collagen scaffolds promoted cell proliferation. The nanofibrous silk–collagen scaffolds provided a three‐dimensional (3D) structure to maximize cell‐matrix penetration and increase differentiation of the EnSCs. Human EnSCs seeded on 3D nanofibrous silk–collagen scaffolds and differentiated to urothelial cells provide a suitable source for potential use in bladder wall reconstruction in women. Copyright © 2013 John Wiley & Sons, Ltd.     

Three New α-Thalassemia Point Mutations Ascertained Through Newborn Screening

We report three new α-thalassemia (thal) point mutations detected during newborn screening for hemoglobinopathies. The first mutation is a single nucleotide deletion (?A) that abolishes the translation initiation codon of the α2-globin gene, detected in a newborn of Hmong ethnicity who carried the Southeast Asian α⁰-thal deletion (α^Tα/– –^SEA). The second mutation, a frameshift caused by a single nucleotide deletion in exon 2 of the α1-globin gene [codon 78 (?C)], was detected in a Black/Chinese newborn who also carried the Southeast Asian α⁰-thal deletion (αα^T/– –^SEA). The third mutation was a frameshift in exon 3 of the α2-globin gene, codons 113/114 (?C). This mutation was detected in a newborn who carried the 3.7 kb α⁺-thal deletion (α^Tα/–α^3.7).