Breast cancer is the most common malignancy in women. Radiotherapy is frequently used in patients with breast cancer, but some patients may be more susceptible to ionizing radiation, and increased exposure to radiation sources may be associated to radiation adverse events. This susceptibility may be related to deficiencies in DNA repair mechanisms that are activated after cell-radiation, which causes DNA damage, particularly DNA double strand breaks. Some of these genetic susceptibilities in DNA-repair mechanisms are implicated in the etiology of hereditary breast/ovarian cancer (pathologic mutations in the BRCA 1 and 2 genes), but other less penetrant variants in genes involved in sporadic breast cancer have been described. These same genetic susceptibilities may be involved in negative radiotherapeutic outcomes. For these reasons, it is necessary to implement methods for detecting patients who are susceptible to radiotherapy-related adverse events. This review discusses mechanisms of DNA damage and repair, genes related to these functions, and the diagnosis methods designed and under research for detection of breast cancer patients with increased radiosensitivity.

The ideal in vitro recreation of the micro-tumor niche—although much needed for a better understanding of cancer etiology and development of better anticancer therapies—is highly challenging. Tumors are complex three-dimensional (3D) tissues that establish a dynamic cross-talk with the surrounding tissues through complex chemical signaling. An extensive body of experimental evidence has established that 3D culture systems more closely recapitulate the architecture and the physiology of human solid tumors when compared with traditional 2D systems. Moreover, conventional 3D culture systems fail to recreate the dynamics of the tumor niche. Tumor-on-chip systems, which are microfluidic devices that aim to recreate relevant features of the tumor physiology, have recently emerged as powerful tools in cancer research. In tumor-on-chip systems, the use of microfluidics adds another dimension of physiological mimicry by allowing a continuous feed of nutrients (and pharmaceutical compounds). Here, we discuss recently published literature related to the culture of solid tumor-like tissues in microfluidic systems (tumor-on-chip devices). Our aim is to provide the readers with an overview of the state of the art on this particular theme and to illustrate the toolbox available today for engineering tumor-like structures (and their environments) in microfluidic devices. The suitability of tumor-on-chip devices is increasing in many areas of cancer research, including the study of the physiology of solid tumors, the screening of novel anticancer pharmaceutical compounds before resourcing to animal models, and the development of personalized treatments. In the years to come, additive manufacturing (3D bioprinting and 3D printing), computational fluid dynamics, and medium- to high-throughput omics will become powerful enablers of a new wave of more sophisticated and effective tumor-on-chip devices.

We demonstrated acceleration of osteogenesis in a dog model for bone distraction by using an implant of BMP-2 modified MSCs. These results are helpful for future clinical trials of mandible bone distraction.

The genetic makeup of Indigenous populations inhabiting Mexico has been strongly influenced by geography and demographic history. Here, we perform a genome-wide analysis of 716 newly genotyped individuals from 60 of the 68 recognized ethnic groups in Mexico. We show that the genetic structure of these populations is strongly influenced by geography, and our demographic reconstructions suggest a decline in the population size of all tested populations in the last 15–30 generations. We find evidence that Aridoamerican and Mesoamerican populations diverged roughly 4–9.9 ka, around the time when sedentary farming started in Mesoamerica. Comparisons with ancient genomes indicate that the Upward Sun River 1 (USR1) individual is an outgroup to Mexican/South American Indigenous populations, whereas Anzick-1 was more closely related to Mesoamerican/South American populations than to those from Aridoamerica, showing an even more complex history of divergence than recognized so far.

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Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but it has been associated with autoimmune processes. Gene polymorphisms in the tumor necrosis factor-α (TNF-α) have been associated with several imflammatory diseases. In particular, the -308G/A polymorphism in the gene promoter region has been reported to be associated with increased plasma levels of TNF-α and with an increased risk to develop autoimmune diseases. To date, this polymorphism has not been associated with vitiligo. To assess a possible association between the TNF-α -308G/A and vitiligo vulgaris (VV), 198 vitiligo patients and 395 control subjects were recruited for the study. A complete demographic and clinical profile of each case was registered to analyze the possible risk factors of vitiligo. Genomic DNA isolated from peri pheral blood was subjected to PCR-RFLP for genotyping of the TNF-α -308G/A polymorphism. Causal associations were determined by χ(2) test and their respective OR was assessed in a 2×2 contingency table. When population variables of type of vitiligo, gender, age of disease onset, and active disease status were considered, an association between active VV and the TNF-α GA genotype was found (P=0.0295, OR=2.0; 95% CI 1.01-3.93). All other variables were irrelevant to vitiligo. Our data suggest a possible association between the TNF-α -308 GA genotype and the active form of VV in a Mexican population.

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