Strategies to overcome acquired resistance to EGFR TKI in the treatment of non-small cell lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) represents a paradigm shift in the treatment of non-small cell lung cancer (NSCLC) patients and has been the first-line therapy in clinical practice. While erlotinib, gefitinib and afatinib have achieved superior efficacy in terms of progression-free survival and overall survival compared with conventional chemotherapy in NSCLC patients, most people inevitably develop acquired resistance to them, which presents another challenge in the treatment of NSCLC. The mechanisms of acquired resistance can be classified as three types: target gene mutation, bypass signaling pathway activation and histological transformation. And the most common mechanism is T790M which accounts for approximately 50% of all subtypes. Many strategies have been explored to overcome the acquired resistance to EGFR TKI. Continuation of EGFR TKI beyond progressive disease is confined to patients in asymptomatic stage when the EGFR addiction is still preserved in some subclones. While the combination of EGFR TKI and chemotherapy or other targeted agents has improved the survival benefit in EGFR TKI resistant patients, there are controversies within them. The next-generation EGFR TKI and immunotherapy represent two novel directions for overcoming acquired resistance and have achieved promising efficacy. Liquid biopsy provides surveillance of the EGFR mutation by disclosing the entire genetic landscape but tissue biopsy is still indispensable because of the considerable rate of false-negative plasma.

MicroRNA-200a promotes proliferation and invasion of ovarian cancer cells by targeting PTEN.

OBJECTIVE: We investigate whether microRNA-200a could regulate proliferation and invasion of ovarian cancer cells, thereby participating in the occurrence and development of ovarian cancer. We also explore the specific mechanism of microRNA-200a in regulating ovarian cancer. PATIENTS AND METHODS: Expression level of microRNA-200a in ovarian cancer tissues and paracancerous tissues were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The regulatory effects of microRNA-200a on proliferation and invasion of ovarian cancer cells were examined by Cell counting kit-8 (CCK-8) and cell invasion assay, respectively. Dual-luciferase reporter gene assay was performed to confirm the binding relationship between microRNA-200a and PTEN (phosphatase and tensin homolog deleted on chromosome ten). The regulatory role of microRNA-200a in PTEN expression was accessed by Western blot. Rescue experiments were conducted to assess whether microRNA-200a regulated proliferation and invasion of ovarian cancer cells by inhibiting PTEN expression. RESULTS: MicroRNA-200a expression in ovarian cancer tissues was significantly higher than that of paracancerous tissues. Besides, microRNA-200a was also overexpressed in ovarian cancer cell lines than that of normal ovarian cells. Overexpression of microRNA-200a promoted the proliferative and invasive abilities of SKOV3 and OVCAR3 cells. Dual-luciferase reporter gene assay showed that microRNA-200a could directly degrade PTEN. Overexpression of PTEN in SKOV3 and OVCAR3 cells partially reversed the increased cell proliferation and invasion induced by overexpressed microRNA-200a. CONCLUSIONS: Overexpressed microRNA-200a promoted the proliferative and invasive abilities of ovarian cancer cells, which might be related to the targeted regulation of PTEN expression.

The CRISPR/Cas system inhibited the pro-oncogenic effects of alternatively spliced fibronectin extra domain A via editing the genome in salivary adenoid cystic carcinoma cells.

OBJECTIVES: To identify the association of fibronectin (FN) extra domain A (EDA) with the progression of salivary adenoid cystic carcinoma (SACC). Accordingly, the exclusion of EDA exon through the CRISPR/Cas9 system was investigated as the rescue for such pro-oncogenic splicing. MATERIALS AND METHODS: SACC-83 cells were transiently transfected with plasmids containing recombinant EDA, and the cellular growth and motility were then accessed in vitro. Epithelial-mesenchymal transition (EMT) was investigated with immunohistochemistry, Western blot, and real-time PCR analysis. SACC tissues from 81 patients were used to access the associations between EDA+FN and clinical-pathological parameters. CRISPR/Cas9 plasmids containing sgRNA were designed and co-transfected into SACC-83 cells; the effects of EDA knockout on cellular growth and motility were then accessed. RESULTS: The recombinant EDA exhibited little effect on the proliferation of SACC cells, but significantly promoted the migration and invasion of the cells (P < 0.05), accompanied with upregulated EMT (P < 0.05); consistently, the expression of EDA+FN was positively associated with the metastasis, nerve invasion and recurrence of SACC (P < 0.05). Furthermore, the EDA knockout from the FN gene in most SACC cells resulted in a decrease in cell motility and invasion, as well as prolonged population doubling time, compared with untreated SACC-83 cells (P < 0.05). CONCLUSION: The EDA domain significantly promoted the motility of SACC cells, and positively associated with the tumor progression in patients with SACC. Thus, it is a potential risk factor and also a therapeutic target for SACC. The CRISPR/Cas9 system may control a pro-oncogenic splicing process through the exclusion of EDA exon from the FN gene, leading to inhibition of motility, invasion and proliferation of cancer cells.

Effects of environmental factors on sperm motility and fertilization rate of Phascolosoma esculenta.

The study investigated the effects of environmental factors (salinity, pH, ions and activation media) on sperm motility (activation rate, duration of quick movement, and lifespan) and fertilization rate of Phascolosoma esculenta. The results showed that spermatozoa in the coelom and nephridium are able to move quickly. The optimal salinity was 14.64 to 43.35 and the optimal pH was 6.46 to 9.53 for sperm activation and motility, whereas the ranges for fertilization were narrower (18.56 to 30.3 for salinity and 6.46 to 8.61 for pH). Of the ions studied, Na+ was indispensable for sperm motility and fertilization, and Ca2+ and Mg2+ were necessary for fertilization. P. esculenta sperm could not fertilize eggs and have short lifespans in 200 to 600 mmol/L NaCl and KCl solutions. Furthermore, they could not be activated or move in 200 to 600 mmol/L CaCl2, MgSO4, and sucrose solutions.

Efficiency and dissipation in a two-terminal thermoelectric junction, emphasizing small dissipation.

The efficiency and cooling power of a two-terminal thermoelectric refrigerator are analyzed near the limit of vanishing dissipation (ideal system), where the optimal efficiency is the Carnot one, but the cooling power vanishes. This limit, where transport occurs only via a single sharp electronic energy, has been referred to as "strong coupling" or "the best thermoelectric." Confining the discussion to the linear-response regime, it is found that "parasitic" effects that make the system deviate from the ideal limit, and reduce the efficiency from the Carnot limit, are crucial for the usefulness of the device. Among these parasitics, there are: parallel phonon conduction, finite width of the electrons' transport band, and more than a single energy transport channel. In terms of a small parameter characterizing the deviation from the ideal limit, the efficiency and power grow linearly, and the dissipation quadratically. The results are generalized to the case of broken time-reversal symmetry, and the major nontrivial changes are discussed. Finally, the recent universal relation between the thermopower and the asymmetry of the dissipation between the two terminals is briefly discussed, including the small dissipation limit.

First Report of Stachybotrys chartarum Causing Leaf Blight of Tillandsia tenuifolia in China.

Tillandsia tenuifolia L. is an air plant that is native to Bolivia, Brazil, and Venezuela. It was introduced to China in 2006. In September 2008, a leaf blight of T. tenuifolia 'Bronze Tip' was observed in a greenhouse in Jurong, Jiangsu. Severe infection led to death of foliage, shoot rot, and eventual mortality of whole plants. The pathogen was isolated from the diseased leaves on potato dextrose agar and subsequently further cultured on a slide culture for 7 days. Anamorphic structures were examined under a compound microscope. Diseased plant parts were covered with abundant conidia, phialides, conidiophores, and mycelia of the pathogen. Conidiophores were simple or branched, zero to two septate, hyaline, smooth at base, brown, smooth to rough at upper portion, and 47.9 ± 7.6 × 4 ± 0.4 µm (n = 30). Phialides were one-celled, obovate, hyaline to pale brown, 8.8 ± 0.9 × 5.3 ± 0.3 µm (n = 20), and in whorls. Conidia were one-celled, ellipsoid to subglobose, dark brown to black, rough to ridged, 10.4 ± 1.4 × 6.2 ± 0.9 µm (n = 30), and in slimy masses. Using morphological characters, the pathogen was identified as Stachybotrys chartarum (Ehrenb.) S. Hughes (1). The living culture was deposited in the China General Microbiological Culture Collection Center (CGMCC 3.13634). S. chartarum, a saprophyte with a worldwide distribution, grows on various substrates such as soil, paper, dry walls, and wood. (2). It was also isolated from moldy sorghum seed and soybean root lesions (3,4). Pathogenicity on T. tenuifolia was confirmed by Koch's postulates in the laboratory. Ninety-six leaves on four plants were pricked with a sterilized needle and inoculated with a suspension of 6.35 × 106 conidia ml-1. Forty-seven leaves on two plants were pricked and sprayed with sterile water as controls. All the plants were kept in a growth chamber with a 12-h photoperiod, 28 ± 1°C, and relative humidity of 70 ± 3%. Initial lesions, which were water soaked, slightly sunken, and pinhead size, appeared on the inoculated plants in 7 days and expanded to 1.5 to 2.0 mm in 21 days. Necrotic spots subsequently coalesced and caused the death of the leaves. Infected shoots were rotten and shed leaves from the basal area. The plants died within 45 days. Symptoms were similar to those observed in the greenhouse. S. chartarum was reisolated from infected leaves. Control plants remained healthy. To confirm the identity of our isolate, DNA sequence was obtained from the internal transcribed spacer (ITS) region and deposited in GenBank (GU945205). The ITS sequence was 100% identical to S. chartarum strains whose DNA sequences were deposited in GenBank. To our knowledge, this is the first report of S. chartarum causing leaf blight on T. tenuifolia. The popularity of T. tenuifolia continues to grow in China. The disease should be monitored to determine its risk and economic significance in China and other regions. References: (1) S. C. Jong and E. E. Davis. Mycotaxon 3:409, 1976. (2) P. M. Kirk. Mycopathologia 115:149, 1991. (3) S. Li et al. Mycopathologia 154:41, 2002. (4) J. Y. Liang and J. K. Bai. J. Shenyang Agric. Univ. 19:27, 1988.

Association study of IFNAR2 and IL10RB genes with the susceptibility and interferon response in HBV infection.

A recent genome-wide association study discovered that two polymorphisms, interferon (IFN) alpha receptor 2 (IFNAR-2) F8S and interleukin 10 receptor (IL10RB) K47E, were associated with susceptibility to hepatitis B virus (HBV) infection in Africa. Here, we reevaluate the effects of the two polymorphisms on HBV susceptibility in the Chinese Han population, and extended the study to look at their association with IFN response in chronic hepatitis B (CHB). We included 341 patients with CHB and 341 unrelated controls presenting with asymptotic HBV self-limited infection, who were well matched in age and sex. In the CHB group, 101 patients had been treated with peg-IFN-alpha-2a for 48 weeks and followed up for 24 weeks to determine the clinical response, resulting 34 individuals with sustained virological response (SVR) and 67 individuals with nonsustained response (NR). Subgroups in the CHB group were divided according to the viral loads, HBeAg and maternal HBsAg status. The association with the susceptibility to HBV infection was only observed for IL10RB K47E when we compared the individuals with persistent HBV infection through nonmaternal transmission to the controls with asymptomatic self-limited HBV infection. Further, we found that the IFNAR2-8SS genotype was associated with HBeAg negative patients (OR = 0.316, 95% CI: 0.121-0.825, P = 0.019) and that the IFNAR2-8F allele was associated with the risk to high viral loads (OR = 1.667, 95% CI: 1.148-2.420, P = 0.007). In addition, the IFNAR2-8FF genotype predisposed to higher MxA gene induction and correlated with sustained IFN response (OR = 0.348, 95% CI: 0.129-0.935, P = 0.036). Haplotype analysis based on polymorphisms of three single-nucleotide polymorphisms, MxA - 88 G/T, IFNAR-2 F8S and IL10RB K47E showed that the haplotype distribution was significantly different between the SVR and NR groups (P = 0.040). This study suggests that IFNAR2 may play an important role in determining IFN response and clinical phenotypes of HBV infection in the Chinese Han population.

SO2 removal with ferric sulfate solution.

The determination of the influence of the concentration of ferric sulfate solution on SO2 absorption was performed in this study. It was found that the SO2 absorption efficiency increased with increasing ferric concentration, and decreased with the acidity of the spraying solution. As the hydrolysis of ferric ions occurs in solution, the SO2 removal efficiency increased slowly with increasing Fe(III) concentration. Taking into account the hydrodynamic and mass transfer characteristics of the packed column, the enhancement factor (E) was found to depend on the concentration of the ferric ions and pH, which indicated that it could be used for the simulation or design of SO2 scrubbers.