Surgical resection and peri-operative chemotherapy for colorectal cancer liver metastases: A population-based study

BACKGROUND

Most literature describing surgery for colorectal cancer (CRC) liver metastases (LM) comes from high volume centres. Here, we report management and outcomes achieved in routine clinical practice.

METHODS

All cases of CRC in Ontario who underwent resection of LM in 1994-2009 were identified using the population-based Ontario Cancer Registry. Electronic treatment records identified chemotherapy delivery. Temporal trends are described for 3 periods: 1994-1999, 2000-2004, 2005-2009. We describe volume of resected CRCLM as a ratio of incident cases per CRCLM resection. Overall (OS) and cancer-specific survival (CSS) are measured from time of LM resection.

RESULTS

2717 patients underwent resection of CRCLM. Between 1994 and 2009 there was a 78% increase in case volume; from one resection for every 48 incident cases to one resection for every 27 incident cases, p < 0.001. Use of peri-operative chemotherapy increased over study periods from 44% (306/700), to 52% (429/830), to 65% (777/1187, p < 0.001). Chemotherapy utilization rates varied across geographic regions (range 43%-69%, p < 0.001). Post-operative mortality rates at 30 and 90 days were 2.5% and 4.3% respectively. Five year OS during the study periods was 36% (95% CI 32-39%), 40% (95% CI 36-43%), and 46% (95% CI 43-49%) (p < 0.001); CSS was 38% (95% CI 35-42%), 42% (95% CI 38-45%), 49% (95% CI 44-53%) (p < 0.001). The temporal improvement in OS/CSS persisted on adjusted analyses.

CONCLUSIONS

Outcomes of patients with resected CRCLM in routine practice is comparable to those reported from high volume centres. Survival improved over the study period despite a greater proportion of patients with CRC undergoing liver resection.

Synthesis, characterization and targeting chemotherapy for ovarian cancer of trastuzumab-SN-38 conjugates

Antibody-drug conjugates (ADCs), combining monoclonal antibody with high cytotoxicity chemotherapeutic drug (warhead), have been successfully applied for clinical cancer therapy. Linker technology to select and design linker connecting warhead with antibody, is critical to the success of therapeutic ADCs. In this study, three kinds of linkers were designed to connect SN-38, the bioactive metabolite of the anticancer drug irinotecan (CPT-11), which is 100-1000 times more potent than CPT-11, with the anti-HER2 antibody trastuzumab to prepare three different ADC conjugates (T-SN38 A, B and C). Meanwhile, we compared the anti-ovarian cancer effect of these three T-SN38 conjugates with trastuzumab in vitro and in vivo. Our in vitro results showed that T-SN38 A, B and C (drug-to-antibody ratio, DAR=3.7, 3.2, 3.4) were 2 to 3 times as cytotoxic as SN-38, and the IC50 for these three conjugates on SKOV-3 cell line at 72 h were 5.2 ± 0.3, 4.4 ± 0.7, and 5.1 ± 0.4 nM respectively. In our in vivo studies, T-SN38 conjugates had well targeting ability for tumor tissue and all three of them had much higher anti-ovarian cancer potency than trastuzumab. Among of them, T-SN38 B, which coupled SN-38 with trastuzumab by a carbonate bond, has the best anti-ovarian cancer potency. In conclusion, the novel HER2-targeting ADCs T-SN38 have great potential for HER2-positive ovarian cancer. Moreover, the SN-38-Linkers designed in this study can also be used to connect with other antibodies for the therapy of other cancers.

Expression level and distribution of HMGB1 in Sombati's cell model and kainic acid-induced epilepsy model

OBJECTIVE

Observe the expression and distribution of HMGB1 in Sombati's cell model and kainic acid-induced epileptic rats' model.

MATERIALS AND METHODS

Dissociated hippocampal neurons from neonatal SD rats and cultured those for 9 days, then changed medium to Mg2+-free medium for 3 hours to induce Sombati's cell model. The expression level of HMGB1 in the neurons was detected at 24h and 72h by Western Blotting. Appropriate kainic acid was injected into the lateral ventricles to induced epileptic rats' model in vivo trial, the expression level and distribution of HMGB1 at 24h and 72h were established by immunohistochemistry.

RESULTS

The expression level of HMGB1 showed significantly different between model group and control group both in vitro and in vivo trials. At 24h, the expression level of HMGB1 in the model group was lower than the control group (p < 0.05), and became higher than the control group at 72h (p < 0.05). From the in vivotrial, a nucleus-to-cytoplasm translocation was also discovered.

CONCLUSIONS

This investigation indicates that HMGB1 plays a crucial role in the pathophysiology of epilepsy, by altering its quantity and distribution.

Immune memory responses to HBV vaccine 13-18 years after primary vaccination

The aim of this study was to evaluate the immune memory response 13-18 years after an hepatitis B virus (HBV) vaccine by performing a specific in vitro stimulation experiment. Thirty healthy volunteers who had been inoculated 13-18 years ago with the HBV vaccine were collected from the physical examination center. Peripheral blood mononuclear cells were stimulated with 50 ng/mL recombinant HBsAg. An ELISA kit was used for the detection of antibodies that were produced by these cells in vitro. It was found that even 13-18 years after inoculation with the HBV vaccine, an anamnestic antibody response still existed, and was not correlated with the serum antibody levels (r = -0.177, P = 0.377). In conclusion, our data showed that the individuals after inoculation, including those with anti-HBs <10 IU/L as well as those individuals in whom the antibody was not detected, retained immune memory, which may be the main role of memory B cells.

Neonatal Overfeeding in Female Mice Predisposes the Development of Obesity in their Male Offspring via Altered Central Leptin Signalling

The prevalence of obesity among child-bearing women has increased significantly. The adverse consequences of maternal obesity on the descendants have been well accepted, although few studies have examined the underlying mechanisms. We investigated whether neonatal overfeeding in female mice alters metabolic phenotypes in the offspring and whether hypothalamic leptin signalling is involved. Neonatal overfeeding was induced by reducing the litter size to three pups per litter, in contrast to normal litter size of 10 pups per litter. Normal and neonatally overfed female mice were bred with normal male mice, and offspring of overfeeding mothers (OOM) and control mothers (OCM) were generated. We examined body weight, daily food intake, leptin responsiveness and the number of positive neurones for phosphorylated-signal transducer and activator of transcription 3 (pSTAT3) along with neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH) and NPY in the nucleus tractus solitarius (NTS) of the brain stem. The body weight and daily food intake of OOM were significantly higher than those of OCM. Leptin significantly reduced food intake and increased the number of pSTAT3 positive neurones in the ARH of OCM mice, whereas no significant changes in food intake and pSTAT3 neurones were found in leptin-treated OOM mice. The number of NPY neurones in the ARH and NTS of the OOM mice was significantly higher than that of OCM mice. The results of the present study indicate that the obese phenotype from mothers can be passed onto the subsequent generation, which is possibly associated with hypothalamic leptin resistance.

Use of multisequence 3.0-T MRI to detect severe traumatic brain injury and predict the outcome

OBJECTIVE

The aim of this study was to evaluate multisequence 3.0-T MRI in the detection of severe traumatic brain injury (sTBI) and in predicting the outcome.

METHODS

32 patients with sTBI were prospectively enrolled, and multisequence 3.0-T MRI was performed 4-8 weeks post injury. Quantitative data were recorded on each sequence. The ability to display the parenchymal lesions was compared with that of 64-slice spiral CT. The clinical and radiological results were correlated with the Glasgow Outcome Scale Extended scores 6 months after injury.

RESULTS

3.0-T MRI could display more lesions than CT, especially when the lesion was deeply located. The lesion volumes and diffuse axonal injury (DAI) scores were different between good and poor outcome groups on fluid attenuated inversion recovery (p < 0.05). The apparent diffusion coefficient (ADC) values of the splenium of the corpus callosum and brain stem were also different (p < 0.05). Patients with unfavourable outcome showed a significantly higher volume of haemorrhage on susceptibility-weighted imaging than those with favourable outcomes and had haemorrhages generally located more deeply. Logistic regression analysis revealed that the location of haemorrhage and the ADC values of the splenium of the corpus callosum were independent risk factors for poor outcome, with an overall predictive accuracy of 91.4%.

CONCLUSION

The joint use of conventional and advanced sequences of 3.0-T MRI can comprehensively detect the pathological changes occurring after sTBI. Haemorrhagic and non-haemorrhagic DAIs in deep structures strongly suggest poor outcome.

ADVANCES IN KNOWLEDGE

This article improves the understanding of advanced MRI sequences in the detection of patients with sTBI and prediction of prognosis.

Covalent modification of DNA by α, β-unsaturated aldehydes derived from lipid peroxidation: Recent progress and challenges

Oxidative stress-induced lipid peroxidation (LPO) has been associated with human physiology and pathophysiology. LPO generates an array of oxidation products and among them reactive lipid aldehydes have received intensive research attentions due to their roles in modulating functions of biomolecules through covalent modification. Thus, covalent modification of DNA by these reactive lipid electrophiles has been postulated to be partially responsible for the biological roles of LPO. In this review, we summarized recent progress and challenges in studying the roles of covalent modification of DNA including nuclear and mitochondrial DNA by reactive lipid metabolites from LPO. We focused on the novel mechanistic insights into generation of lipid aldehydes from cellular membranes especially mitochondria through LPO. Recent advances in the technological front using mass spectrometry have also been highlighted in the settings of studying DNA damage caused by LPO and its biological relevance.

Evaluation of cesium-137 conversion models and parameter sensitivity for erosion estimation

The Cs technique has been widely used to provide soil redistribution estimates since the 1970s. However, most Cs-conversion models remain theoretical and largely unvalidated. Our objectives were to validate the four widely used conversion models, examine model parameter sensitivity, and evaluate the potential of using kriging to improve soil redistribution estimation. Soil loss was measured from a 1.6-ha plot since 1978. Winter wheat ( L.) was grown primarily under conventional tillage. Soil samples in a 10-m grid were taken from the plot to estimate the Cs inventory. Soil redistribution rates were estimated using four models and were further interpolated using ordinary kriging. The parameter sensitivity analyses at the 95% confidence limits showed that reference inventory had the most impact on estimated water erosion, followed by particle size correction for erosion and tillage depth, with minimal impacts from mass depth, bulk density, and particle size correction for deposition. Compared with the measured water erosion, the relative errors of the mean net water erosion estimates across the entire plot without and with kriging were 28 and -17% for the proportional model (PM), 141 and 106% for the simplified mass balance model, 133 and 100% for the improved mass balance model (MBM2), and 109% for the extended MBM2 with tillage erosion (MBM3). Results indicated that the PM performed better than the mass balance models under the study conditions and that kriging improved mean soil redistribution estimates. However, the full potential of the MBM2 and MBM3 needs to be further evaluated under conditions where loss of newly deposited Cs exists.

A novel in vitro assay for assessing efficacy and toxicity of antifungals using human leukaemic cells infected with Candida albicans

AIMS

This study describes a novel in vitro assay that simultaneously determines antifungal efficiency and host cell toxicity using suspensions of human leukaemic cells (HL-60) infected with Candida albicans.

METHODS AND RESULTS

The effect of Candida infection on host cell viability was evaluated by the microscopy of trypan blue-stained cells and lactate dehydrogenase (LDH) activity. The in vitro 'drug potency assay' utilized the Cell Counting Kit-8 and measured post-antifungal treatment viability of Candida-infected HL-60 cells and the ability of the antifungal treatment to prevent infection. LDH activity showed that 42% ± 4·0 and 85·3% ± 7·40 of HL-60 cells were killed following Candida infection at the multiplicity of infection (MOI) of 1 : 1 and 1 : 5, respectively. The antifungal nystatin (0·78-25 μmol l(-1) ) was found to inhibit C. albicans infection as seen by the significantly increased viability of HL-60 cells. Cytotoxicity of nystatin towards infected HL-60 cells was evident at higher concentrations and this was also confirmed by propidium iodide staining.

CONCLUSIONS

An assay using undisturbed cell suspension conditions was successfully developed for assessing the selectivity of the antifungal therapy in the host-Candida environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The assay employing Candida infection of host cell suspensions represents a promising method for testing interactions of antifungal compounds with both fungal and host cells.

Towards a resolution of the proton form factor problem: new electron and positron scattering data

There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45  GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75  GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3  GeV(2).

Longitudinal target-spin asymmetries for deeply virtual compton scattering

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions.

MiR-873 regulates ERα transcriptional activity and tamoxifen resistance via targeting CDK3 in breast cancer cells

miRNAs (microRNAs) are frequently and aberrantly expressed in many cancers. MiR-873 has been revealed to be downregulated in colorectal cancer and glioblastoma. However, its function remains unclear. Here we report that miR-873 is downregulated in breast tumor compared with normal tissue. Enforced expression of miR-873 decreases the transcriptional activity of ER (estrogen receptor)-α but not ERβ through the modulation of ERα phosphorylation in ER-positive breast cancer cells. We also found that miR-873 inhibits breast cancer cell proliferation and tumor growth in nude mice. Reporter gene assays revealed cyclin-dependent kinase 3 (CDK3) as a direct target of miR-873. CDK3 was shown to be overexpressed in breast cancer and phosphorylate ERα at Ser104/116 and Ser118. Furthermore, we found that Mir-873 inhibits ER activity and cell growth via targeting CDK3. Interestingly, miR-873 was observed to be downregulated in tamoxifen-resistant MCF-7/TamR cells, while CDK3 is overexpressed in these cells. More importantly, re-expression of miR-873 reversed tamoxifen resistance in MCF-7/TamR cells. Our data demonstrate that miR-873 is a novel tumor suppressor in ER-positive breast cancer and a potential therapeutic approach for treatment of tamoxifen-resistant breast cancer.

Kinome-wide screening of HER2+ breast cancer cells for molecules that mediate cell proliferation or sensitize cells to trastuzumab therapy

Understanding the signaling differences that distinguish human HER2-amplified (HER2-positive (HER2+)) breast cancers from other breast cancer subtypes may help to identify protein drug targets for the specific treatment of HER2+ breast cancers. We performed two kinome-wide small interfering RNA (siRNA) screens on five HER2+ breast cancer cell lines, seven breast cancer cell lines in which HER2 was not amplified and two normal breast cell lines. To pinpoint the main kinases driving HER2 signaling, we performed a comprehensive siRNA screen that identified loss of the HER2/HER3 heterodimer as having the most prominent inhibitory effect on the growth of HER2+ breast cancer cells. In a second siRNA screen focused on identifying genes that could sensitize HER2+ cells to trastuzumab treatment, we found that loss of signaling members downstream of phosphatidylinositol 3 kinase (PI3K) potentiated the growth inhibitory effects of trastuzumab. Loss of HER2 and HER3, as well as proteins involved in mitogenic and environmental stress pathways inhibited the proliferation of HER2+ cells only in the absence of trastuzumab, suggesting that these pathways are inhibited by trastuzumab treatment. Loss of essential G2/M cell cycle mediators or proteins involved in vesicle organization exerted inhibitory effects on HER2+ cell growth that were unaffected by trastuzumab. Furthermore, the use of a sensitization index (SI) identified targeting the PI3K pathway to sensitize to trastuzumab treatment. Antagonism using the SI identified MYO3A, MYO3B and MPZL1 as antagonizers to trastuzumab treatment among HER2+ cell lines. Our results suggest that the dimerization partners of HER2 are important for determining the activation of downstream proliferation pathways. Understanding the complex layers of signaling triggered downstream of HER2 homodimers and heterodimers will facilitate the selection of better targets for combination therapies intended to treat HER2+ breast cancers.