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To investigate the dynamics of stomata, transpiration, and photosynthesis under varying light intensities and CO 2 conditions during leaf development, the light response and CO 2 response of stomatal conductance ( g sw ), transpiration rate ( T r ), and net photosynthetic rate ( P n ) were observed for rice leaves at different days after leaf emergence (DAE). The results showed that (1) as photosynthetically active radiation (PAR) increased, leaf g sw , T r , and P n initially increased rapidly and linearly, followed by a more gradual rise to maximum values, and then either stabilized or showed a declining trend. The maximum g sw , T r , and P n were smaller and occurred earlier for old leaves than for young leaves. The g sw , T r , and P n all exhibited a linear decreasing trend with increasing DAE, and the rate of decrease slowed down with the reduction in PAR; (2) as the CO 2 concentration ( C a ) increased, g sw and T r decreased gradually to a stable minimum value, while P n increased linearly and slowly up to the maximum and then kept stable or decreased. The g sw , T r , and P n values initially kept high and then decreased with the increase of DAE. These results contribute to understanding the dynamics in g sw , T r , and P n during rice leaf growth and their response to varied light and CO 2 concentration conditions and provide mechanistic support to estimate dynamic evapotranspiration and net ecosystem productivity at field-scale and a larger scale in paddy field ecosystems through the upscaling of leaf-level stomatal conductance, transpiration, and photosynthesis.

Background Ovarian cancer (OC) is the most lethal malignant gynecological tumor type for which limited therapeutic targets and drugs are available. Enhanced mitochondrial oxidative phosphorylation (OXPHOS), which enables cell growth, migration, and cancer stem cell maintenance, is a critical driver of disease progression and a potential intervention target of OC. However, the current OXPHOS intervention strategy mainly suppresses the activity of the electron transport chain directly and cannot effectively distinguish normal tissues from cancer tissues, resulting in serious side effects and limited efficacy. Methods We screened natural product libraries to investigate potential anti-OC drugs that target OXPHOS. Additionally, LC-MS, qRT-PCR, western-blot, clonogenic assay, Immunohistochemistry, wound scratch assay, and xenograft model was applied to evaluate the anti-tumor mechanism of small molecules obtained by screening in OC. Results Gossypol acetic acid (GAA), a widely used gynecological medicine, was screened out from the drug library with the function of suppressing OXPHOS and OC progression by targeting the leucine-rich pentatricopeptide repeat containing (LRPPRC) protein. Mechanically, LRPPRC promotes the synthesis of OXPHOS subunits by binding to RNAs encoded by mitochondrial DNA. GAA binds to LRPPRC directly and induces LRPPRC rapid degradation in a ubiquitin-independent manner. LRPPRC was overexpressed in OC, which is highly correlated with the poor outcomes of OC and could promote the malignant phenotype of OC cells in vitro and in vivo. GAA management inhibits cell growth, clonal formation, and cancer stem cell maintenance in vitro, and suppresses subcutaneous graft tumor growth in vivo. Conclusions Our study identified a therapeutic target and provided a corresponding inhibitor for OXPHOS-based OC therapy. GAA inhibits OC progression by suppressing OXPHOS complex synthesis via targeting LRPPRC protein, supporting its potential utility as a natural therapeutic agent for ovarian cancer.

Objective To investigate the efficacy and mechanism of ultrasound-targeted microbubble destruction (UTMD) combined with radiotherapy (XRT) on glioblastoma. Methods The enhanced radiosensitization by UTMD was assessed through colony formation and cell apoptosis in Human glioblastoma cells (U87MG). Subcutaneous transplantation tumors in 24 nude mice implanted with U87MG cells were randomly assigned to 4 different treatment groups (Control, UTMD, XRT, and UTMD + XRT) based on tumor sizes (100–300 mm 3 ). Tumor growth was observed for 10 days after treatment, and then histopathology stains (HE, CD34, and γH2AX) were applied to the tumor samples. A TUNEL staining experiment was applied to detect the apoptosis rate of mice tumor samples. Meanwhile, tissue proteins were extracted from animal specimens, and the expressions of dsDNA break repair-related proteins from animal specimens were examined by the western blot. Results When the radiotherapy dose was 4 Gy, the colony formation rate of U87MG cells in the UTMD + XRT group was 32 ± 8%, lower than the XRT group (54 ± 14%, p  < 0.01). The early apoptotic rate of the UTMD + XRT group was 21.1 ± 3% at 48 h, higher than that of the XRT group (15.2 ± 4%). The tumor growth curve indicated that the tumor growth was inhibited in the UTMD + XRT group compared with other groups during 10 days of observation. In TUNEL experiment, the apoptotic cells of the UTMD + XRT group were higher than that of the XRT group ( p  < 0.05). The UTMD + XRT group had the lowest MVD value, but was not significantly different from other groups ( p  > 0.05). In addition, γH2AX increased due to the addition of UTMD to radiotherapy compared to XRT in immunohistochemistry ( p  < 0.05). Conclusions Our study clearly demonstrated the enhanced destructive effect of UTMD combined with 4 Gy radiotherapy on glioblastoma. This could be partly achieved by the increased ability of DNA damage of tumor cells.

Background. Wogonin is a plant monoflavonoid and has been reported to induce apoptosis of cancer cells and show inhibitory effect on cancer cell growth. However, the detailed and underlying molecular mechanisms are not elucidated. In this study, we investigated the molecular and biological effects of wogonin in human ovarian A2780 cancer cells. Materials and Methods. We determined the effects of wogonin on the changes of cell cycling and apoptotic responses of cells. Western blot analysis was used to measure the effects of wogonin on protein expressions. Results. Our results showed that treatment with wogonin inhibited the cancer cell proliferation, decreased the percentage of G0/G1 subpopulation, and reduced invasiveness of A2780 cells. Exposure to wogonin also resulted in downregulated protein levels of estrogen receptor alpha (ER-α), VEGF, Bcl-2, and Akt and increased expressions of Bax and p53. In addition, exposure to wogonin increased caspase-3 cleavage and induced apoptosis in A2780 cells. Our study further showed that MPP, a specific ER-α inhibitor, significantly enhanced antitumor effects of wogonin in A2780 cells. Conclusion. Our results suggest a potential clinical impact of wogonin on management of ovarian cancer.

Polyphyllin I (PPI) is an active component in Rhizoma Paridis, which displays extensive pharmacological antitumor activities. In a previous study, we found that polyphyllin I exhibited inhibitory effects on cell growth in the human ovarian cancer HO-8910PM cell line, as well as promoting apoptosis and the inhibition of cell migration. Furthermore, gene expression was also profiled by microarray, which showed that numerous genes were altered by PPI; three genes were of particular note that were associated with tumor progression, namely, Caspase-9, C-jun and Wnt5a. In the present study, the effect of PPI on subcutaneous tumor growth (HO-8910PM cells) in nude mice was further evaluated, and immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) were used to examine the expression of Caspase-9, C-jun and Wnt5a in subcutaneous and lung metastatic tumor tissues, in order to investigate the possible mechanisms involved. The results showed that PPI significantly inhibited the tumor growth in vivo without a marked impact on body weight, and through use of immunohistochemical staining and RT-PCR, it was found that the expression of Caspase-9 and Wnt5a was decreased, while the expression of C-jun was increased, in subcutaneous and lung metastatic tumor tissue; this was consistent with the in vitro results. In conclusion, the present study showed that PPI exerted antitumor activity on ovarian cancer cells in vivo, and indicated that the modulation of Caspase-9, C-jun and Wnt5a may be involved in the antitumor effect of PPI.

Ovarian cancer leads the worst prognosis among all types of gynecologic malignancies, and patients are often diagnosed at an advanced stage. Ovarian cancer also has a high rate of metastasis; however, the detailed mechanisms for ovarian cancer prone to metastasis remain unclear. In this study, we used continuous in vitro screening of the human ovarian cancer A2780 cell line to establish a cell line (A2780-M) which shows high invasiveness and motility. Compared to the parental cells, A2780-M cells express elevated protein levels of CD44, CD133, CD34, and β-catenin. A2780-M cells are also more resistant to chemotherapeutic agents SN-38 and Docetaxel. Thus, the A2780-M cell line is a new ovarian metastatic cancer cell line that expresses tumor stem cell surface markers and adhesion-related membrane proteins and is with higher motility and invasiveness.

Background Programmed cell death 6 (PDCD6) beside its known proapoptotic functions may be a player in survival pathways in cancer. The purpose of this study is to further explore the roles of PDCD6 in epithelial ovarian cancer. Methods Lentiviral vector with shRNA for PDCD6 was used to investigate the effects of PDCD6 knockdown on cell growth, cell cycle, apoptosis and motility in ovarian cancer cells. Two hundred twelve epithelial ovarian cancer tissues were analyzed for mRNA expression of PDCD6 using RT-PCR. Associations of its expression with clinical pathological factors, progression free and overall survival were evaluated. Results PDCD6 is highly expressed in metastatic ovarian cancer cells and positively regulates cell migration and invasion. Significantly, the level of PDCD6 expression in epithelial ovarian cancer correlates with clinical progression. Patients with medium or high levels of PDCD6 mRNA were at higher risk for disease progression, compared to those with low levels (HR, 1.29; P = 0.024 for medium levels; and HR, 1.57; P = 0.045 for high levels) after adjusting for age, disease stage, tumor grade, histologic type and residual tumor size. Kaplan-Meier survival analysis demonstrated similar results. However, no association was found between PDCD6 expression and overall survival. Conclusions PDCD6 seems to play an important role in ovarian cancer progression and it may be an independent predictor of progression free survival in epithelial ovarian cancer. Further studies are needed to more completely elucidate the molecular mechanisms of PDCD6 involve in ovarian cancer progression.

To investigate the dynamics of stomata, transpiration, and photosynthesis under varying light intensities and CO conditions during leaf development, the light response and CO response of stomatal conductance ( ), transpiration rate ( ), and net photosynthetic rate ( ) were observed for rice leaves at different days after leaf emergence (DAE). The results showed that (1) as photosynthetically active radiation (PAR) increased, leaf , , and initially increased rapidly and linearly, followed by a more gradual rise to maximum values, and then either stabilized or showed a declining trend. The maximum , , and were smaller and occurred earlier for old leaves than for young leaves. The , , and all exhibited a linear decreasing trend with increasing DAE, and the rate of decrease slowed down with the reduction in PAR; (2) as the CO concentration ( ) increased, and decreased gradually to a stable minimum value, while increased linearly and slowly up to the maximum and then kept stable or decreased. The , , and values initially kept high and then decreased with the increase of DAE. These results contribute to understanding the dynamics in , , and during rice leaf growth and their response to varied light and CO concentration conditions and provide mechanistic support to estimate dynamic evapotranspiration and net ecosystem productivity at field-scale and a larger scale in paddy field ecosystems through the upscaling of leaf-level stomatal conductance, transpiration, and photosynthesis.

Gene chip technology can be used to identify and localize signal transduction genes associated with metastasis. We used the human genome U133A gene chip to detect differences in gene expression profiles among high (H) and low (L) metastatic human ovarian cancer cell lines (HO-8910PM, HO-8910), and normal ovarian tissues (C), to identify metastasis-associated signal transduction genes and determine their chromosomal localizations. A total of 37 signal transduction genes showed more than twofold differences in expression levels between the H and L metastatic ovarian cancer cell lines; of these, 21 genes were up-regulated [signal log ratio (SLR)  ≥ 1], and 16 genes were down-regulated (SLR  ≤ −1). Most genes were located on chromosome 1 (7 genes, 18.9%), followed by chromosome 8 (5 genes, 13.5%), then chromosomes 6, 11, and 17 (3 genes each, 8.1%). A total of 21 of the differentially expressed genes (56.7%) were localized on the short arm of the chromosome (q). The disruption of signal transduction gene expression may be an important factor associated with ovarian cancer metastasis. The affected signal transduction genes were localized to chromosomes 1, 8, 6, 11, and 17.

The PandaX-4T experiment, a 4-ton scale dark matter direct detection experiment, is being planned at the China Jinping Un- derground Laboratory. In this paper we present a simulation study of the expected background in this experiment. In a 2.8-ton fiducial mass and the signal region between 1–10 keV electron equivalent energy, the total electron recoil background is found to be 4:9 × 10 −5 kg −1 d −1 keV −1 . The nuclear recoil background in the same region is 2:8 × 10 −7 kg −1 d −1 keV −1 . With an exposure of 5.6 ton-years, the sensitivity of PandaX-4T could reach a minimum spin-independent dark matter-nucleon cross section of 6 × 10 −48 cm 2 at a dark matter mass of 40 GeV/ c 2 .