Serum YB-1 (Y-box binding protein 1) as a biomarker of bone disease progression in patients with breast cancer and bone metastases

YB-1 (Y-box binding protein 1) is a multifunctional cold-shock protein that has been implicated in all hallmarks of cancer. Elevated YB-1 protein level was associated with poor prognosis in several types of cancers, including breast cancer (BC), where it is a marker of decreased overall survival (OS) and distant metastasis-free survival across all subtypes. YB-1 is also secreted by different cell types and may act as an extracellular mitogen; however the pathological implications of the secreted form of YB-1 (sYB-1) are unknown. Our purpose was to retrospectively evaluate the association between YB-1 measured by ELISA in serum and disease characteristics and outcomes in patients with BC and bone metastases (BM). In our cohort, sYB-1 was detected in the serum of 22 (50%) patients, and was associated with the presence of extra-bone metastases (p=0.044). Positive sYB-1 was also associated with faster bone disease progression (HR 3.1, 95% CI 1.09–8.95, P=0.033), but no significant differences were observed concerning OS, and time to development of skeletal-related events. Moreover, patients with positive sYB-1 also had higher levels of IL-6, a known osteoclastogenic inducer. Therefore, detection of sYB-1 in patients with BC and BM may indicate a higher tumor burden, in bone and extra-bone locations, and is a biomarker of faster bone disease progression.

Studies with neuronal cells: From basic studies of mechanisms of neurotoxicity to the prediction of chemical toxicity

Neurotoxicology considers that chemicals perturb neurological functions by interfering with the structure or function of neural pathways, circuits and systems. Using in vitro methods for neurotoxicity studies should include evaluation of specific targets for the functionalism of the nervous system and general cellular targets. In this review we present the neuronal characteristics of primary cultures of cortical neurons and of cerebellar granule cells and their use in neurotoxicity studies. Primary cultures of cortical neurons are constituted by around 40% of GABAergic neurons, whereas primary cultures of cerebellar granule cells are mainly constituted by glutamatergic neurons. Both cultures express functional GABAA and ionotropic glutamate receptors. We present neurotoxicity studies performed in these cell cultures, where specific neural targets related to GABA and glutamate neurotransmission are evaluated. The effects of convulsant polychlorocycloalkane pesticides on the GABAA, glycine and NMDA receptors points to the GABAA receptor as the neural target that accounts for their in vivo acute toxicity, whereas NMDA disturbance might be relevant for long-term toxicity. Several compounds from a list of reference compounds, whose severe human poisoning result in convulsions, inhibited the GABAA receptor. We also present cell proteomic studies showing that the neurotoxic contaminant methylmercury affect mitochondrial proteins. We conclude that the in vitro assays that have been developed can be useful for their inclusion in an in vitro test battery to predict human toxicity.

Pro12Ala substitution in the peroxisome proliferator-activated receptor-gamma is associated with increased leptin levels in women with type-2 diabetes mellitus

OBJECTIVE

To analyze the relationship between the peroxisome proliferator-activated receptor-gamma (PPARgamma2) Pro12Ala variant and type-2 diabetes mellitus and its correlation with some cytokine determinants of insulin resistance such as tumor necrosis factor (TNF)-alpha and leptin.

METHODS

The PPARgamma2 Pro12Ala genetic polymorphism was studied in 167 type-2 diabetic patients and 63 healthy controls. Serum leptin and plasma-soluble TNF-R2 were measured.

RESULTS

Women carriers of the Pro12Ala mutation exhibited higher leptin levels than women non-carriers (median 31.4 vs. 17.5 ng/ml; p < 0.005). sTNF-R2 levels did not show differences between the two genotypes. Analysis by the multiple linear regression model of leptin-body mass index controlled by the PPARgamma2 genotype showed that leptin levels were determined by the Pro12Ala mutation in type-2 diabetic women but not in men.

CONCLUSIONS

PPARgamma2 seems to be implicated in leptin homeostasis in type-2 diabetic women.

Bone mineral mass is associated with interleukin 1 receptor autoantigen and TNF-alpha gene polymorphisms in post-menopausal Mediterranean women

Bone mass is known to be under genetic control. Interleukin-1 (IL-1), interleukin-6 (IL-6) and TNF-alpha are strong inductors of bone resorption. The estrogenic deficiency that occurs during menopause leads to an increase in the production of these cytokines. We analyzed the genetic susceptibility of several polymorphisms of the interleukin-1 receptor antagonist (IL-1ra), IL-6 and TNF-alpha genes in lumbar spine and hip bone mass in a sample of post-menopausal Caucasian Mediterranean women with osteoporosis. 104 post-menopausal osteoporotic women (58.6+/-4.8 yr) and 51 post-menopausal women without osteoporosis as the control group (57.2+/-4.5 yr) were studied. The osteoporotic group was in turn sub-classified into severe and non-severe osteoporosis. The variable number of tandem repeats IL1-ra, IL-6 SfaNI and TNF-alpha NcoI genetic polymorphisms were studied. Biochemical markers of bone turnover were measured in blood and urine. Women carrying the A2 allele (A2+) of the IL-1ra gene showed greater BMD in the lumbar spine (p=0.02) and hip (p=0.006), compared to those not carrying the allele (A2-). The IL-6 polymorphism studied in its 5' flanking region did not show any association with BMD values. The TNF-alpha gene G allele was associated with a greater bone mass in the non-severe osteoporotic subgroup, both in the lumbar spine (p=0.0007) and in the hip (p=0.02). Likewise, genotype combination A2+GG was associated to a greater hip BMD at the femoral neck and Ward triangle levels (p=0.02). We conclude that both IL-1ra and TNF-alpha can be candidate loci to be studied in the susceptibility to develop post-menopausal osteoporosis.