Apoptosis and cancer: mutations within caspase genes

The inactivation of programmed cell death has profound effects not only on the development but also on the overall integrity of multicellular organisms. Beside developmental abnormalities, it may lead to tumorigenesis, autoimmunity, and other serious health problems. Deregulated apoptosis may also be the leading cause of cancer therapy chemoresistance. Caspase family of cysteinyl-proteases plays the key role in the initiation and execution of programmed cell death. This review gives an overview of the role of caspases, their natural modulators like IAPs, FLIPs, and Smac/Diablo in apoptosis and upon inactivation, and also in cancer development. Besides describing the basic mechanisms governing programmed cell death, a large part of this review is dedicated to previous studies that were focused on screening tumours for mutations within caspase genes as well as their regulators. The last part of this review discusses several emerging treatments that involve modulation of caspases and their regulators. Thus, we also highlight caspase cascade modulating experimental anticancer drugs like cFLIP-antagonist CDDO-Me; cIAP1 antagonists OSU-03012 and ME-BS; and XIAP small molecule antagonists 1396-11, 1396-12, 1396-28, triptolide, AEG35156, survivin/Hsp90 antagonist shephedrin, and some of the direct activators of procaspase-3.

Facile Synthesis of Novel Nanostructured MnO(2) Thin Films and Their Application in Supercapacitors

Nanostructured alpha-MnO(2) thin films with different morphologies are grown on the platinum substrates by a facile solution method without any assistance of template or surfactant. Microstructural characterization reveals that morphology evolution from dandelion-like spheres to nanoflakes of the as-grown MnO(2) is controlled by synthesis temperature. The capacitive behavior of the MnO(2) thin films with different morphologies are studied by cyclic voltammetry. The alpha-MnO(2) thin films composed of dandelion-like spheres exhibit high specific capacitance, good rate capability, and excellent long-term cycling stability.

Polyphyllin D Exerts Potent Anti-tumour Effects on Lewis Cancer Cells under Hypoxic Conditions

Paris polyphylla has been used to treat cancer in China for many years and components of the plant, such as polyphyllin D, may have potent antiproliferative effects in vitro To investigate the potential antitumour effects of polyphyllin D on cancer cells under hypoxia, Lewis lung cancer cells and mouse tracheal epithelial cells were cultured with or without polyphyllin D under normoxic and hypoxic conditions. Proliferation and apoptosis of cells were assayed. Real-time reverse transcription–polymerase chain reaction was used to quantify the expression of hypoxia-inducible factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) mRNA. Polyphyllin D decreased cell proliferation, increased apoptosis and inhibited expression of HIF-1α and VEGF mRNAs in Lewis cells. These effects were greater under hypoxic than normoxic conditions. Polyphyllin D did not show a cytotoxic effect in non-tumour cells (mouse skin fibroblasts and tracheal epithelial cells). These results suggest that polyphyllin D potentially has anticancer effects in vitro under hypoxia.

Stromal gene signatures in large-B-cell lymphomas

BACKGROUND

The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear.

METHODS

We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group.

RESULTS

A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted survival both in patients who received CHOP and patients who received R-CHOP. The prognostically favorable stromal-1 signature reflected extracellular-matrix deposition and histiocytic infiltration. By contrast, the prognostically unfavorable stromal-2 signature reflected tumor blood-vessel density.

CONCLUSIONS

Survival after treatment of diffuse large-B-cell lymphoma is influenced by differences in immune cells, fibrosis, and angiogenesis in the tumor microenvironment.

The metabolic effects of once daily extended-release metformin in patients with type 2 diabetes: a multicentre study

AIM

To investigate the effects of extended-release metformin (MXR) compared with immediate-release metformin (MIR) on post-prandial glycaemic excursion, chronic glycaemia, lipid profiles, insulin resistance and islet function in type 2 diabetes.

METHODS

A randomised, open-labelled, positive-controlled multicentre study was conducted on 150 Chinese patients with type 2 diabetes. After 2 weeks of run-in period with MIR, 150 subjects were randomised into MXR group and MIR group. The patients in MXR group were assigned to take MXR 1500 mg once daily after dinner, while the patients in MIR group were assigned to continue MIR 500 mg thrice daily after meals for 12 weeks. Standard meal tests were carried out at baseline and at the end of this study. Plasma glucose, serum insulin, HbA1c and lipid profiles were measured. Homeostasis model assessment (HOMA) was used to evaluate insulin resistance index (HOMA-IR) and islet beta-cell function index (HOMA-B).

RESULTS

Either MIR or MXR modestly, but significantly decreased HbA1c levels and body mass index (BMI) after 12 weeks of treatment. However, there were no significant differences between two groups. The post-prandial glycaemia at 120 min after a standard meal in MXR group was higher than in MIR group (11.02 +/- 3.08 mmol/l vs. 9.74 +/- 2.61 mmol/l, p < 0.05). Moreover, no differences in the areas under curve of insulin release response, HOMA-B, HOMA-IR and lipid profiles were found within or between groups after 12 weeks of treatment.

CONCLUSION

The effects of once daily MXR on chronic glycaemia, BMI, lipid profiles, insulin resistance and islet function are comparable with that of thrice daily MIR in oriental population.

The significance of BOLD MRI in differentiation between renal transplant rejection and acute tubular necrosis

BACKGROUND

Blood oxygen level-dependent MRI (BOLD MRI) can be used to assess intra-renal oxygen bioavailability by measuring the R2(*) level, which reflects tissue deoxyhaemoglobin levels. This study was designed to identify the significance of BOLD MRI in differentiation of acute rejection (AR) and acute tubular necrosis (ATN) in patients within 6 months after kidney transplantation.

METHODS

Eighty-two patients with normal graft function and 28 patients with biopsy-proven AR (n = 21) or ATN (n = 7) were enrolled. Patients with normal functioning allograft underwent BOLD MRI within 2 to 3 weeks post-transplantation, while patients with AR and ATN underwent BOLD MRI within 6 days before or after kidney transplant biopsy. Cortical R2(*) (CR2(*)) and medullary R2(*) (MR2(*)) levels were measured.

RESULTS

The mean CR2(*) level was significantly higher in the ATN group (15.25 +/- 1.03/s) compared to the normal group (13.35 +/- 2.31/s, P = 0.028) and AR group (12.02 +/- 1.72/s, P = 0.001). There was a significant difference also between the AR group and normal group on CR2(*) levels (P = 0.013). The mean MR2(*) level was significantly lower in the AR group (14.02 +/- 2.68/s) compared to the normal group (16.66 +/- 2.82/s, P < 0.001) and ATN group (19.47 +/- 1.62/s, P < 0.001). There was also a significant difference between the ATN group and normal group on MR2(*) levels (P = 0.011). There were no correlations between characteristics such as patient age, post-operation time, post-biopsy time, Scr level, HB level, urine output volume, MAP level, CNI trough concentration and R2(*) levels, except between MAP level and CR2(*) level (P = 0.029).

CONCLUSIONS

BOLD MRI could be a valuable method to discriminate between AR and ATN by measuring tissue oxygen bioavailability in early kidney allograft dysfunction.

NS-398 enhances the efficacy of gemcitabine against lung adenocarcinoma through up-regulation of p21WAF1 and p27KIP1 protein

Gemcitabine is a chemotherapeutic drug widely used in the treatment of non-small cell lung carcinoma, especially in advanced lung adenocarcinoma. However, many patients with advanced lung adenocarcinoma show a resistance to gemcitabine. Overexpression of COX-2 has been found in human non-small cell lung cancer tissues and itA s cell lines. Evidences show that COX-2 is involved in drug resistance of tumor. However, It is unknown whether COX-2 inhibitor can augment the efficacy of gemcitabine against lung adenocarcinoma. In this study, A549 cells were treated with gemcitabine and/or NS-398. The cell viability was examined by MTT assay. The cell cycle distribution and apoptotic ratio were tested by flow cytometry. The levels of p21WAF1, p27KIP1, p16INK4a and p15INK4b expression were detected by western blotting. After the cells were treated with gemcitabine along with NS-398, more cells were arrested in G1 phase and went to apoptosis. The levels of p21WAF1 and p27KIP1 protein were elevated, while the levels of p16INK4a and p15INK4b protein were not changed. It can be concluded that NS-398 enhances the efficacy of gemcitabine against lung adenocarcinoma and the efficacy is associated with up-regulation of p21WAF1 and p27KIP1protein.

Nearly completely reversible brain abnormalities in a patient with incontinentia pigmenti

SUMMARY

We report a case of incontinentia pigmenti with reversible cortex and subcortical white matter necrosis-like presentation by MR imaging. The reversible changes in follow-up imaging of the patient with incontinentia pigmenti suggest a course of natural repair of inflammation or cerebrovascular disease.

Transition-Metal-Catalyzed Group Transfer Reactions for Selective C−H Bond Functionalization of Artemisinin

Three types of novel artemisinin derivatives have been synthesized through transition-metal-catalyzed intramolecular carbenoid and nitrenoid C-H bond insertion reactions. With rhodium complexes as catalysts, lactone 11 was synthesized via carbene insertion reaction at the C16 position in 90% yield; oxazolidinone 13 was synthesized via nitrene insertion reaction at the C10 position in 87% yield based on 77% conversion; and sulfamidate 14 was synthesized via nitrene insertion reaction at the C8 position in 87% yield.

U19/Eaf2 knockout causes lung adenocarcinoma, B-cell lymphoma, hepatocellular carcinoma and prostatic intraepithelial neoplasia

Upregulated gene 19 (U19)/ELL-associated factor 2 (Eaf2) is a potential human tumor suppressor that exhibits frequent allelic loss and downregulation in high-grade prostate cancer. U19/Eaf2, along with its homolog Eaf1, has been reported to regulate transcriptional elongation via interaction with the eleven-nineteen lysine-rich leukemia (ELL) family of proteins. To further explore the tumor-suppressive effects of U19/Eaf2, we constructed and characterized a murine U19/Eaf2-knockout model. Homozygous or heterozygous deletion of U19/Eaf2 resulted in high rates of lung adenocarcinoma, B-cell lymphoma, hepatocellular carcinoma and prostate intraepithelial neoplasia. Within the mouse prostate, U19/Eaf2 deficiency enhanced cell proliferation and increased epithelial cell size. The knockout mice also exhibited cardiac cell hypertrophy. These data indicate a role for U19/Eaf2 in growth suppression and cell size control as well as argue for U19/Eaf2 as a novel tumor suppressor in multiple mouse tissues. The U19/Eaf2 knockout mouse also provides a unique animal model for three important cancers: lung adenocarcinoma, B-cell lymphoma and hepatocellular carcinoma.

Chemotherapy-evoked painful peripheral neuropathy: analgesic effects of gabapentin and effects on expression of the alpha-2-delta type-1 calcium channel subunit

Chemotherapeutics in the taxane and vinca-alkaloid classes sometimes produce a painful peripheral neuropathy for which there is no validated treatment. Experiments with rat models of paclitaxel- and vincristine-evoked pain suggest that these conditions may not respond to all of the analgesics that have efficacy in other models of painful peripheral neuropathy. We tested gabapentin as a potential analgesic for paclitaxel- and vincristine-evoked pain. We used a repeated dosing paradigm because there are precedents showing that repeated drug exposure may be necessary to demonstrate analgesia in neuropathic pain models. Gabapentin is believed to work via binding to voltage-gated calcium channels that contain the alpha-2-delta type-1 (alpha(2)delta-1) subunit, and the expression of this subunit is known to be increased in some painful peripheral neuropathy models. Thus we also examined whether the paclitaxel-evoked pain syndrome was accompanied by an alpha(2)delta-1 increase, and whether gabapentin had any effect on subunit expression. We found that the paclitaxel- and vincristine-evoked mechano-allodynia and mechano-hyperalgesia were significantly reduced by gabapentin, but only with repeated dosing. Paclitaxel-evoked painful peripheral neuropathy was associated with an increased expression of the alpha(2)delta-1 subunit in the spinal dorsal horn, but not in the dorsal root ganglia. The spinal cord increase was normalized by repeated gabapentin injections. Together, these findings suggest that repeated dosing with gabapentin may be beneficial in patients with chemotherapy-evoked painful peripheral neuropathy and that gabapentin's mechanisms of action may include normalization of the nerve injury-evoked increase in calcium channel alpha(2)delta-1 subunit expression.