Circulating tumor cell isolation,culture, and downstream molecular analysis

Circulating tumor cells (CTCs) are a major contributor of cancer metastases and hold a promising prognostic significance in cancer detection. Performing functional and molecular characterization of CTCs provides an in-depth knowledge about this lethal disease. Researchers are making efforts to design devices and develop assays for enumeration of CTCs with a high capture and detection efficiency from whole blood of cancer patients. The existing and on-going research on CTC isolation methods has revealed cell characteristics which are helpful in cancer monitoring and designing of targeted cancer treatments. In this review paper, a brief summary of existing CTC isolation methods is presented. We also discuss methods of detaching CTC from functionalized surfaces (functional assays/devices) and their further use for ex-vivo culturing that aid in studies regarding molecular properties that encourage metastatic seeding. In the clinical applications section, we discuss a number of cases that CTCs can play a key role for monitoring metastases, drug treatment response, and heterogeneity profiling regarding biomarkers and gene expression studies that bring treatment design further towards personalized medicine.     

Comprehensive identification of major flowering time genes and their combinations,which determined rice distribution in Northeast China

Flowering time of rice (Oryza sativa L.) is among the most important agronomic traits for regional adaptation and grain yield. To date, a number of genes or quantitative trait loci (QTLs) controlling flowering time have been identified in rice, and diverse natural allelic variations for these flowering genes have been revealed, which suggested that the underlying regulation mechanism of flowering time in rice is very complicated. Northeast China is a major cultivation region for temperate japonica rice, where the temperature is cooler and the day length is longer. The regional adaptability of local rice cultivar is substantially different from that of other regions. Recently, some flowering genes have been proved to play roles in regulating flowering time of local cultivars. However, a comprehensive analysis of the effectiveness of these flowering genes has not been performed. In the present study, 395 cultivars collected from Northeast China is re-sequenced, SNP and InDel markers were called for 23 selected flowering-related genes. The heading date of these cultivars was also investigated for three consecutive years. Through association analysis, we found that Hd2, Hd4, and Hd5 are major flowering repressors, whereas Dth2 and Hd18 are major flowering promoters. Furthermore, Hd6 and Hd16 were identified as minor flowering repressors, and Hd17 was minor flowering promoter, in that their effectiveness can exclusively be detected when both Hd2 and Hd4 are functional. Collectively, we comprehensively identified the major and minor flowering genes which determine flowering time of temperate japonica rice grown in Northeast China.     

Rap1A Regulates Osteoblastic Differentiation via the ERK and p38 Mediated Signaling

Rap1A is a member of small G proteins belonging to the Ras family. Recently, an integration of human genome-wide association studies (GWAS) and gene expression profiling study revealed that single-nucleotide polymorphisms (SNPs) within human Rap1A were strongly associated with narrow neck width in women. However, the regulatory role of Rap1A in osteoblasts remains to be elucidated. Here we report that Rap1A is a key regulator in osteoblast differentiation. Rap1A expression and activity were gradually enhanced during the induced differentiation of multipotent mesenchymal progenitor cells (C2C12) and preosteoblastic cells (MC3T3-E1). Knockdown of endogenous Rap1A significantly inhibited the osteogenic marker gene expression and matrix mineralization in cells with osteogenesis. In addition, knockdown of endogenous Rap1A suppressed the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), while overexpression of Rap1A accelerated osteoblast differentiation and enhanced the phosphorylation of ERK and p38. Taken together, our study suggests that Rap1A regulates osteoblast differentiation through modulating the ERK/p38 signaling.     

Moderate/Severe Hyponatremia Increases the Risk of Death among Hospitalized Chinese Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome Patients

Objectives

To evaluate whether the serum sodium concentration is associated with the progression and long-term prognosis of Chinese HIV/AIDS patients.

Methods

Three hundred and eighty seven hospitalized patients were recruited into this retrospective cohort study. The strata of serum sodium concentration were moderate/severe hyponatremia, mild hyponatremia and normonatremia. Disease progression was estimated using CD4 counts and the WHO clinical stage. Correlation analysis was used to evaluate the serum sodium concentration with disease progression. The Kaplan-Meier method and the Cox proportional hazards model were used to analyze the effect of different serum sodium levels on survival.

Results

In this study 206 patients (53.2%) had hyponatremia, including 10.6% patients with moderate/severe hyponatremia and 42.6% with mild hyponatremia. The serum sodium concentration was significantly correlated with the HIV/AIDS progression (P<0.001). During the follow-up, 100 patients (25.6%) died. The cumulative survival rates of HIV/AIDS patients were 47.8%±8.5% in patients with moderate/severe hyponatremia, 59.8%±5.0% with mild hyponatremia and 79.9%±3.4% with normonatremia (log-rank P<0.001). After adjusting for sex, age, WHO stage, CD4 count, hemoglobin and albumin, the relative hazard was 3.5 (95% CI: 1.9–6.5) for patients with moderate/severe hyponatremia (P<0.001), and 1.5 (95% CI: 0.9–2.4) for those with mild hyponatremia (P = 0.161), compared with normonatremic patients.

Conclusions

The serum sodium level is closely correlated with the severity of patients. Only moderate/severe hyponatremia affects the prognosis of Chinese HIV/AIDS patients. Earlier intensive medical managements(including HAART)are necessary to increase the survival rates of Chinese HIV/AIDS patients with moderate/severe hyponatremia.