Cancer stem cells: targeting tumors at the source

The cancer stem cell hypothesis states that tumors rely exclusively on the continued proliferation of a subset of cancer cells that originated from normal adult stem cells. These cells have two key traits: multipotency, and self-renewal. The prolonged lifespan of stem cells makes them perfect candidates for the accumulation of carcinogenic mutations that would convert them into cancer stem cells (CSCs) no longer responsive to the many regulatory pathways in place that are responsible for tight governance of proliferation and differentiation in normal stem cells. Comprehending what these regulatory pathways are, and how their derailment contributes to oncogenic transformation, can hold the key to finding new strategies to target CSCs in order to effectively treat cancer. Additionally, what environmental factors are involved in promoting or suppressing CSC tumorigenicity requires attention. The possibility that some cancers may have clonal origins in non-stem cell populations that were able to acquire stem cell-like properties, and the lack of complete cell autonomy in carcinogenesis, suggests that the CSC hypothesis is continually evolving. Continued research in this field can shed light on how effective selective elimination of CSCs as opposed to generalized targeting of cancer cells will be in the treatment of cancer.

Utilization of International Association of Diabetes and Pregnancy Study Groups criteria vs. a two-step approach to screening for gestational diabetes mellitus in Chinese women with twin pregnancies

AIM

To evaluate prevalence and pregnancy outcomes using the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria and screening protocol vs. a standard two-step screening approach for gestational diabetes mellitus in Chinese twin pregnancies.

METHODS

A retrospective cohort study for pregnancies during 2007-2013 was performed in a tertiary hospital in Shanghai, China. Data were abstracted from the medical records of twin pregnancies delivered at the hospital. During the period 2007-2011, this hospital used a two-step approach with a 50 g screening with a cut-off value of ≥ 7.8 mmol/l followed by a 100 g diagnostic oral glucose tolerance test (OGTT) utilizing Carpenter-Coustan criteria. In 2012-2013, the hospital switched to the IADPSG protocol of universal 75 g OGTT.

RESULTS

Among 1461 twin pregnancies, 643 were screened utilizing IADPSG criteria and 818 using the two-step protocol. Gestational diabetes mellitus was diagnosed more frequently in the IADPSG group than in the two-step group [20.4% and 7.0%, respectively; adjusted odds ratio (aOR) = 3.22; 95% confidence interval (CI) = 2.30-4.52]. During the IADPSG period, the incidence of pre-eclampsia was 38% lower in non-gestational diabetes mellitus affected pregnancies compared with the two-step period (aOR = 0.62; 95% CI = 0.44-0.87). We observed no significant differences in most perinatal outcomes between the two groups.

CONCLUSION

Compared with a standard two-step approach to screening and diagnosis, the IADPSG screening method resulted in a three-fold increase in the incidence of gestational diabetes mellitus in twin pregnancies, with a 38% lower risk of pre-eclampsia but no significant difference in most perinatal outcomes in non-gestational diabetes mellitus affected pregnancies.

Dietary patterns are associated with prevalence of fatty liver disease in adults

BACKGROUND/OBJECTIVES

Previous studies have indicated that higher levels of food consumption are associated with fatty liver disease (FLD), but few studies have investigated the relationship between this disease and different dietary patterns. The aim of this cross-sectional study was to examine the association between dietary patterns and FLD in adults.

SUBJECTS/METHODS

Dietary intakes of participants in the Tianjin were assessed via questionnaire. Factor analysis was used to identify dietary patterns, and FLD was defined as having a FLD diagnosis using liver ultrasonography. Relationships between dietary patterns and FLD were assessed using multiple logistic regression analysis.

RESULTS

Female participants in the highest quartile of high-carbohydrate/sweet pattern scores had a 2.19-fold greater risk (95% confidence interval (CI), 1.40-3.46) of developing non-alcoholic FLD (NAFLD) than those in the lowest quartile after adjusting for confounding factors. No significant differences were found between any dietary pattern and NAFLD in males. In males, a significantly increasing trend of alcoholic FLD (AFLD) prevalence was associated with increasing high-protein/cholesterol pattern scores (P for trend = 0.03; odds ratio (OR), 2.08; 95% CI, 1.15-3.81) while an increased high-carbohydrate/sweet pattern score appeared protective against AFLD (P for trend = 0.02; OR, 0.55; 95% CI, 0.29-1.00).

CONCLUSIONS

Our study demonstrates that high-protein/cholesterol pattern scores are associated with higher prevalence of AFLD in males. We also show high-carbohydrate/sweet pattern scores are associated with higher prevalence of NAFLD in females; but, interestingly, this pattern shows a favorable effect on AFLD in males.

Synthesis of ovalbumin-stabilized highly fluorescent gold nanoclusters and their application as an Hg2+ sensor

Highly fluorescent Au nanoclusters were synthesized using ovalbumin (OVA) as a template. The application of the nanoclusters for the detection of mercury ions was also achieved.

Dimethyl fumarate attenuates 6-OHDA-induced neurotoxicity in SH-SY5Y cells and in animal model of Parkinson's disease by enhancing Nrf2 activity

Oxidative stress is central to the pathology of several neurodegenerative diseases, including Parkinson's disease (PD), and therapeutics designed to enhance antioxidant potential could have clinical value. In this study, we investigated whether dimethyl fumarate (DMF) has therapeutic effects in cellular and animal model of PD, and explore the role of nuclear transcription factor related to NF-E2 (Nrf2) in this process. Treatment of animals and dopaminergic SH-SY5Y cells with DMF resulted in increased nuclear levels of active Nrf2, with subsequent upregulation of antioxidant target genes. The cytotoxicity of 6-hydroxydopamine (6-OHDA) was reduced by pre-treatment with DMF in SH-SY5Y cells. The increase in the reactive oxygen species caused by 6-OHDA treatment was also attenuated by DMF in SH-SY5Y cells. The neuroprotective effects of DMF against 6-OHDA neurotoxicity were dependent on Nrf2, since treatment with Nrf2 siRNA failed to block against 6-OHDA neurotoxicity and induce Nrf2-dependent cytoprotective genes in SH-SY5Y cells. In vivo, DMF oral administration was shown to upregulate mRNA and protein levels of Nrf2 and Nrf2-regulated cytoprotective genes, attenuate 6-OHDA induced striatal oxidative stress and inflammation in C57BL/6 mice. Moreover, DMF ameliorated dopaminergic neurotoxicity in 6-OHDA-induced PD animal models as evidenced by amelioration of locomotor dysfunction, loss in striatal dopamine, and reductions in dopaminergic neurons in the substantia nigra and striatum. Taken together, these data strongly suggest that DMF may be beneficial for the treatment of neurodegenerative diseases like PD.

Peroxisome proliferator-activated receptor α activation attenuates the inflammatory response to protect the liver from acute failure by promoting the autophagy pathway

Peroxisome proliferator-activated receptor α (PPARα) has been reported to induce a potent anti-inflammatory response. Autophagy is a recently recognized rudimentary cellular response to inflammation and injury. The aim of the present study was to test the hypothesis that PPARα activation mediates autophagy to inhibit liver inflammation and protect against acute liver failure (ALF). PPARα expression during ALF and the impact of PPARα activation by Wy-14 643 on the hepatic immune response were studied in a D-galactosamine/lipopolysaccharide-induced mouse model. Autophagy was inhibited by 3-methyladenine or small interfering RNA (siRNA) against Atg7. In both the mouse model and human ALF subjects, PPARα was significantly downregulated in the injured liver. PPARα activation by pretreatment with Wy-14 643 protected against liver injury in mice. The protective effect of PPARα activation relied on the suppression of inflammatory mechanisms through the induction of autophagy. This hypothesis is supported by the following evidence: first, PPARα activation suppressed proinflammatory responses and inhibited phosphorylated NF-κBp65, phosphorylated JNK and phosphorylated ERK pathways in vivo. Second, protection by PPARα activation was due to the induction of autophagy because inhibition of autophagy by 3-methyladenine or Atg7 siRNA reversed liver protection and inflammation. Third, PPARα activation directly induced autophagy in primary macrophages in vitro, which protected cells from a lipopolysaccharide-induced proinflammatory response. Here, for the first time, we have demonstrated that PPARα-mediated induction of autophagy ameliorated liver injury in cases of ALF by attenuating inflammatory responses, indicating a potential therapeutic application for ALF treatment.

Aspirin may modify tumor microenvironment via antiplatelet effect

High-quality evidence suggests that aspirin is a promising agent for cancer prevention and treatment. Direct inhibition of cyclooxygenase-2 (COX-2) pathway is generally thought to be the main mechanism by which aspirin inhibits cancer development. However, either pharmacological properties of aspirin or recent results of epidemiologic studies do not support that mechanism. To address this inconsistency, we hypothesize that antiplatelet effect of aspirin via inhibition of COX-1 may be one of potential mechanisms to inhibit carcinogenesis. Aberrant platelet activation will lead to promote hostility of tumor microenvironment by releasing an abundant array of angiogenesis regulators. Given the outstanding ability of antiplatelet, aspirin may restore balance of pro- and anti-angiogenic factors released from platelet to "normalize" tumor vasculature and shape tumor microenvironment to some extent, which will not only diminish tumor aggressiveness and progression, but also enhance the sensitivity to therapeutic treatment. Thus, targeting the platelet activation leading to alter tumor microenvironment may provide a novel way to tumor therapy.

Allelic differences between Europeans and Chinese for CREB1 SNPs and their implications in gene expression regulation, hippocampal structure and function, and bipolar disorder susceptibility

Bipolar disorder (BD) is a polygenic disorder that shares substantial genetic risk factors with major depressive disorder (MDD). Genetic analyses have reported numerous BD susceptibility genes, while some variants, such as single-nucleotide polymorphisms (SNPs) in CACNA1C have been successfully replicated, many others have not and subsequently their effects on the intermediate phenotypes cannot be verified. Here, we studied the MDD-related gene CREB1 in a set of independent BD sample groups of European ancestry (a total of 64,888 subjects) and identified multiple SNPs significantly associated with BD (the most significant being SNP rs6785[A], P=6.32 × 10(-5), odds ratio (OR)=1.090). Risk SNPs were then subjected to further analyses in healthy Europeans for intermediate phenotypes of BD, including hippocampal volume, hippocampal function and cognitive performance. Our results showed that the risk SNPs were significantly associated with hippocampal volume and hippocampal function, with the risk alleles showing a decreased hippocampal volume and diminished activation of the left hippocampus, adding further evidence for their involvement in BD susceptibility. We also found the risk SNPs were strongly associated with CREB1 expression in lymphoblastoid cells (P<0.005) and the prefrontal cortex (P<1.0 × 10(-6)). Remarkably, population genetic analysis indicated that CREB1 displayed striking differences in allele frequencies between continental populations, and the risk alleles were completely absent in East Asian populations. We demonstrated that the regional prevalence of the CREB1 risk alleles in Europeans is likely caused by genetic hitchhiking due to natural selection acting on a nearby gene. Our results suggest that differential population histories due to natural selection on regional populations may lead to genetic heterogeneity of susceptibility to complex diseases, such as BD, and explain inconsistencies in detecting the genetic markers of these diseases among different ethnic populations.

Factors influencing response enthusiasm to telephone follow-up in patients with oesophageal carcinoma after oesophagectomy

Response enthusiasm to telephone follow-up is a precondition for obtaining exhaustive information; however, no study has yet examined this specific issue. This study aimed to investigate possible factors influencing response enthusiasm to telephone follow-up in patients with oesophageal carcinoma after oesophagectomy and to propose corresponding countermeasures. A telephone follow-up was conducted on patients who underwent oesophagectomy. The possible factors influencing response enthusiasm grades were investigated by univariate and logistic regression analyses. The study enrolled 346 eligible patients. Univariate analysis showed that the tumour, nodes, metastasis (TNM) staging (P = 0.004); survival status (P < 0.001); survival time (P < 0.001); complications/co-morbidities (P = 0.001); and the relationship between the patient and his/her contact person (P < 0.001) were significantly different among the three groups. The first group of patients had high response enthusiasm, the second group had moderate response enthusiasm, and the third group had low response enthusiasm. Logistic regression analysis demonstrated that only the complications/co-morbidities [confidence interval (CI) = -2.310 to -0.665, P < 0.001] and dysphagia status (CI = 0.039-1.509, P = 0.039) were independent factors affecting the response enthusiasm grades. The primary therapeutic results and the current complications and co-morbidities, especially the dysphagia status, were important factors influencing response enthusiasm grades. Planning a follow-up schedule with proper health instructions could be crucial to the quality of follow-up.

MRI findings of solitary fibrous tumours in the head and neck region

OBJECTIVES

To analyse the MRI findings of solitary fibrous tumours in the head and neck region.

METHODS

We retrospectively reviewed MR images in eight patients with solitary fibrous tumours proven on histological examination. All the patients underwent conventional MRI, and four patients also underwent dynamic contrast-enhanced MRI and diffusion-weighted imaging in five cases. Image characteristics were analysed.

RESULTS

All lesions were found as solitary well-defined masses ranging in size from 1.9 to 6.8 cm (mean, 4.1 cm). They were mostly homogeneous and isointense to the muscle on T1 weighted images and heterogeneous and mildly hyperintense on T2 weighted images. After gadolinium administration, areas that were mildly hyperintense on T2 weighted images were strongly enhanced. They were mildly hyperintense on diffusion-weighted imaging. The average tumour-apparent diffusion coefficient values were 0.001 157 ± 0.000 304 9 mm s(-2) compared with the muscle 0.000 760 ± 0.000 265 0 mm s(-2), and there was a statistical difference of p = 0.002. The time-intensity curves exhibited a rapidly enhancing and a slow washout pattern on dynamic contrast-enhanced MRI.

CONCLUSIONS

Solitary fibrous tumours should be considered in cases of heterogeneous hypervascular tumours in the head and neck region. Areas of mild hyperintense intensity on T2 weighted images that are strongly enhanced after gadolinium injection are suggestive of this diagnosis. Non-restricted diffusion and rapidly enhancing and slow washout pattern time-intensity curves may be additional valuable features.

Usefulness of 3T diffusion-weighted MRI for discrimination of reactive and metastatic cervical lymph nodes in patients with oral squamous cell carcinoma: a pilot study

OBJECTIVES

To study the diagnostic accuracy of 3T diffusion-weighted MRI (DW-MRI) for the discrimination of reactive and metastatic cervical lymph nodes in patients with oral squamous cell carcinoma.

METHODS

DW T1 and T2 weighted MRI was performed in 25 patients with biopsy-proved primary oral squamous cell carcinoma. The mean apparent diffusion coefficient (ADC) values of 30 histopathologically proved reactive lymph nodes and 21 histopathologically proved metastatic lymph nodes were compared using an unpaired t-test. A cut-off ADC value with optimal diagnostic sensitivity, specificity and area under the curve in discrimination of the two groups was determined using a receiver operating characteristic curve analysis.

RESULTS

The mean ADC values of reactive lymph node and metastatic lymph node groups were (1.037 ± 0.149) × 10(-3) and (0.702 ± 0.197) × 10(-3) mm(2) s(-1), respectively. A statistically significant difference in ADC values of the two groups was certified (p < 0.0001). An optimal ADC threshold value of 0.887 × 10(-3) mm(2) s(-1) was suggested as the cut-off point, which resulted in 93.33% sensitivity, 80.95% specificity, 88.20% accuracy and area under curve of 0.887.

CONCLUSIONS

Our preliminary study indicates that the addition of 3T DW-MRI may be useful for discriminating between reactive lymph nodes and metastatic lymph nodes in patients with oral squamous cell carcinoma. However, larger studies are still required to validate our results and to standardize this imaging technique for daily clinical practice.