Population Genetics Identifies Challenges in Analyzing Rare Variants

Geneticists have, for years, understood the nature of genome‐wide association studies using common genomic variants. Recently, however, focus has shifted to the analysis of rare variants. This presents potential problems for researchers, as rare variants do not always behave in the same way common variants do, sometimes rendering decades of solid intuition moot. In this paper, we present examples of the differences between common and rare variants. We show why one must be significantly more careful about the origin of rare variants, and how failing to do so can lead to highly inflated type I error. We then explain how to best avoid such concerns with careful understanding and study design. Additionally, we demonstrate that a seemingly low error rate in next‐generation sequencing can dramatically impact the false‐positive rate for rare variants. This is due to the fact that rare variants are, by definition, seen infrequently, making it hard to distinguish between errors and real variants. Compounding this problem is the fact that the proportion of errors is likely to get worse, not better, with increasing sample size. One cannot simply scale their way up in order to solve this problem. Understanding these potential pitfalls is a key step in successfully identifying true associations between rare variants and diseases.     

Nanomedicines: From Bench to Bedside and Beyond

Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.     

Matrine,oxymatrine, and compound Kushen injection from the roots of Sophora flavescens: an overview of their anticancer activities

In the present review, we updated current information on the chemistry, contents, and anticancer properties of matrine (MT), oxymatrine (OMT), and compound Kushen injection (CKI). The anticancer properties were focused on lung, breast, and liver cancer cells because they are most susceptible. Sources of information were from Google, Google Scholar, PubMed, PubMed Central, Science Direct, PubChem, J-Stage, Directory of Open Access Journals (DOAJ), and China National Knowledge Infrastructure (CNKI). Reference was also made on botanical websites, such as Flora of China and World Flora Online. MT and OMT are dominant quinolizidine alkaloids from the roots of Sophora flavescens (Kushen) of the family Fabaceae. Against lung, breast, and liver cancer cells, MT and OMT inhibit cell proliferation; induce cell cycle arrest, apoptosis, and autophagy; restrict angiogenesis; and inhibit cell metastasis, invasion, and migration. The processes involve various molecular targets and signaling pathways. CKI is a traditional Chinese medicine (TCM) composed of root extracts of S. flavescens and Smilax glabra (Baituling) of the family Smilacaceae. With MT and OMT as major components, CKI has been approved for the treatment of cancer in China more than 20 years ago. In recent years, systematic reviews and meta-analysis have been undertaken to evaluate the anticancer effects of CKI. When CKI is used alone and in combination with chemotherapy of western medicine, there is much to be learned concerning their interactions besides their individual and integrated efficacy. Some perspectives of MT, OMT, and CKI are discussed, and their suggestions for future research are provided.     

Maximizing Breast Cancer Therapy with Awareness of Potential Treatment-Related Blood Disorders

In this review we summarize the impact of the various modalities of breast cancer therapy coupled with intrinsic patient factors on incidence of subsequent treatment-induced myelodysplasia and acute myelogenous leukemia (t-MDS/AML). It is clear that risk is increased for patients treated with radiation and chemotherapy at younger ages. Radiation is associated with modest risk, whereas chemotherapy, particularly the combination of an alkylating agent and an anthracycline, carries higher risk and radiation and chemotherapy combined increase the risk markedly. Recently, treatment with granulocyte colony-stimulating factor (G-CSF), but not pegylated G-CSF, has been identified as a factor associated with increased t-MDS/AML risk. Two newly identified associations may link homologous DNA repair gene deficiency and poly (ADP-ribose) polymerase inhibitor treatment to increased t-MDS/AML risk. When predisposing factors, such as young age, are combined with an increasing number of potentially leukemogenic treatments that may not confer large risk singly, the risk of t-MDS/AML appears to increase. Patient and treatment factors combine to form a biological cascade that can trigger a myelodysplastic event. Patients with breast cancer are often exposed to many of these risk factors in the course of their treatment, and triple-negative patients, who are often younger and/or BRCA positive, are often exposed to all of them. It is important going forward to identify effective therapies without these adverse associated effects and choose existing therapies that minimize the risk of t-MDS/AML without sacrificing therapeutic gain.

Implications for Practice

Breast cancer is far more curable than in the past but requires multimodality treatment. Great care must be taken to use the least leukemogenic treatment programs that do not sacrifice efficacy. Elimination of radiation and anthracycline/alkylating agent regimens will be helpful where possible, particularly in younger patients and possibly those with homologous repair deficiency (HRD). Use of colony-stimulating factors should be limited to those who truly require them for safe chemotherapy administration. Further study of a possible leukemogenic association with HRD and the various forms of colony-stimulating factors is badly needed.