tRNA-Uridine Aminocarboxypropyltransferase DTW Domain Containing 2 Suppresses Colon Adenocarcinoma Progression.

Background: DTW Domain Containing 2 (DTWD2) is a newly identified transfer RNA-uridine aminocarboxypropyltransferase. Dysregulated expression of DTWD1 has been reported in several malignancies, nevertheless, the role of DTWD2 in cancers remains completely unknown. Here, we aimed to initially investigate the expression and role of DTWD2 in colon adenocarcinoma. Methods: We first evaluated the transcription and mRNA levels of DTWD2 using data from The Cancer Genome Atlas. Besides, we tested its mRNA and protein expression in our enrolled retrospective cohort. Univariate and multivariate analyses were conducted to assess its prognostic value. Cellular experiments and xenografts were also performed to validate the role of DTWD2 in colon cancer progression. Results: DTWD2 was downregulated in colon adenocarcinoma and associated with poor prognosis. Lymph node metastasis, distant metastasis, and advanced tumor stage are all characterized by lower DTWD2 levels. Furthermore, Cox regression analysis demonstrated that DTWD2 is a novel independent prognostic factor for colon cancer patients. Finally, cellular and xenograft data demonstrated that silencing DTWD2 significantly enhanced colon cancer growth. Conclusion: Low expression of DTWD2 may be a potential molecular marker for poor prognosis in colon cancer.

The combination therapy of high-intensity focused ultrasound with radiotherapy in locally advanced pancreatic carcinoma.

BACKGROUND: The aim of the present study is to evaluate the effectiveness of the combined application of high-intensity focused ultrasound (HIFU) and radiotherapy in the treatment of locally advanced pancreatic carcinoma (LAPC). METHODS: A total number of sixteen patients with LAPC started treatment beginning with HIFU and radiotherapy 1 week after the HIFU treatment. Evaluation of the effectiveness of treatment was performed using main clinical symptoms, serum levels of CA-19-9, Response Evaluation Criteria in Solid Tumors (RECIST) guidelines, and the Kaplan-Meier method for estimating median overall survival (OS). The occurrence of adverse reactions was recorded. RESULTS: The main clinical symptoms including abdominal pain and lower back pain were alleviated, and the mean visual analog scale (VAS) pain score declined from 5.1 points to just 3.3 points immediately after the HIFU treatment. The median pain relief time was 5.6 months after radiotherapy, serum CA-19-9 levels began to decrease significantly 1 week after the HIFU treatment, from 102.1 to 60.8 U/ml, and the median continuous decline time was 4.3 months after radiotherapy. Partial response (PR) was observed in seven of sixteen patients, with stable disease (SD) in four patients, and progressive disease (PD) in the remaining five patients at 6 months after radiotherapy. Serum levels of amylopsin and lipase were not elevated to abnormal levels. The median OS was 14 months. No serious adverse reactions occurred. CONCLUSIONS: Treatment with both HIFU and radiotherapy can quickly improve symptoms and the quality of life and prolong survival lengths. This combination might be a promising therapeutic treatment for patients with LAPC.

S-adenosylmethionine inhibits the activated phenotype of human hepatic stellate cells via Rac1 and matrix metalloproteinases.

OBJECTIVE: To investigate the effects of S-adenosylmethionine (SAM) on the proliferation, adhesion, migration, invasion and apoptosis of activated human hepatic stellate cells (HSCs) and to explore the relevant potential mechanisms. METHODS: Human HSCs LX-2 were cultured with SAM. The proliferation and adhesion were detected by CCK-8. Cell apoptosis rate were analyzed by flow cytometry, and cell migration and invasion were tested by the transwell assay. The expression of Rac1 and MMP-2 was identified by real-time PCR or Western blotting, and activated Rac1 was detected by GST pull-down assay. The activity of MMP-2 and MMP-9 was analyzed by substrate zymography. RESULTS: The proliferation of LX-2 cells was inhibited by SAM, exhibiting a dose-dependent manner. Cell apoptosis rate induced by SAM was remarkably increased. SAM decreased the adhesion, migration and invasion of LX-2 cells. The expression and activation of Rac1 in LX-2 cells were significantly suppressed by SAM. In contrast, the activity of MMP-2 and MMP-9 was enhanced by SAM. SAM attenuated the up-regulated expression of Smad3/4 and Rac1 induced by TGF-ß1. CONCLUSION: SAM inhibits the proliferation, adhesion, migration and invasion of LX-2 cells in vitro probably via attenuating the expression and activation of Rac1 and up-regulating MMP-2 and MMP-9 expression, which possibly provide a molecular basis for potential application of SAM in the therapy of liver fibrosis.

[Novel synthetic method and analgesic activity of tepoxalin].

Tepoxalin is a potent inhibitor of both the cyclooxygenase and lipoxygenase pathways of the arachidonic acid cascade, as well as a potent anti-inflammatory and control-pain (postoperation, arthritis et. al.) agent. The new method about the use of novel synthesis reagents and the first using ionic liquid as reactive solvent to synthesize tepoxalin were presented in this paper. The ionic liquid can be easily recycled and reused for several runs efficiently. The analgesic activity of tepoxalin was detected by acetic acid test on mice. The analysis of variance showed that oral administration of tepoxalin could significantly inhibit the number of writhing response within 1 hour and prolong the latent time in a dose dependent manner as compared with CMC control group (P < 0.05). At the same time, tepoxalin had the same analgesic activity as diclofenac sodium.

Paclitaxel-doxorubicin sequence is more effective in breast cancer cells with heat shock protein 27 overexpression / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cancer cells with overexpression of heat shock protein 27 (HSP27) are resistant to chemotherapeutic drug doxorubicin (Dox). Paclitaxel (Pacl) was reported to suppress HSP27 expression in ovarian and uterine cancer cells. The purposes of this study were to investigate whether Pacl inhibits the expression of HSP27 in breast cancer cells, whether Pacl can sensitize breast cancer cells with HSP27 overexpression to Dox, and to define a more effective schedule for the combination of Dox with Pacl.</p><p><b>METHODS</b>The HSP27 high-expressing human breast cancer cell lines, MCF-7 and MDA-MB-435, and the HSP27 low-expressing cell line, MDA-MB-231, were used in this study. The level of HSP27, topoisomerase (Topo) IIalpha and beta expression were assessed by Western blotting. The cytotoxic activities of Dox, Pacl and combination of these two drugs were evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and flow cytometric assays.</p><p><b>RESULTS</b>Pacl (0.1 micromol/L) inhibited HSP27 expression by approximately 2-fold in MCF-7 and MDA-MB-435 cells, while up-regulating the level of topo IIalpha and beta. In contrast, expression of HSP27 in MDA-MB-231 did not change significantly following Pacl treatment. There were synergistic effects in both treatment sequences (Pacl-Dox and Dox-Pacl) when Pacl was combined with Dox. Compared with those treated with the Dox-Pacl sequence, the Pacl-Dox sequence had a stronger effect in cancer cells with HSP27 overexpression, as MCF-7 and MDA-MB-435 treated with the Pacl-Dox sequence had lower viabilities and a higher apoptotic rate.</p><p><b>CONCLUSIONS</b>Paclitaxel significantly decreases the level of HSP27 in breast cancer cells overexpressing HSP27. In combination therapies, the Pacl-Dox sequence is more effective in clearing breast cancer cells with high HSP27 expression compared with the Dox-Pacl sequence.</p>

Ataxin 10 induces neuritogenesis via interaction with G-protein beta2 subunit.

Spinocerebellar ataxia type 10 (SCA10) is a dominantly inherited disorder caused by an intronic ATTCT pentanucleotide repeat expansion. The ATXN10 gene encodes a novel protein, ataxin 10, known previously as E46L, which is widely expressed in the brain. Ataxin 10 deficiency has been shown recently to cause increased apoptosis in primary cerebellar cultures, thus implicated in SCA10 pathogenesis. The biologic functions of ataxin 10 remain largely unknown. By using yeast-two-hybrid screening of a human brain cDNA library, we identified the G-protein beta2 subunit (Gbeta2) as an ataxin 10 binding partner, and the interaction was confirmed by coimmunoprecipitation and colocalization in mammalian cells in culture. Overexpression of ataxin 10 in PC12 cells induced neurite extension and enhanced neuronal differentiation induced by nerve growth factor (NGF). Moreover, coexpression of ataxin 10 and Gbeta2 potently activated the Ras-MAP kinase-Elk-1 cascade. Dominant negative Ras or inhibitor of MEK-1/2 (U0126) aborted this activation, and blocked morphologic changes, whereas inhibition of TrkA receptor by K252a had no effects. Our data suggest that the ataxin 10-Gbeta2 interaction represents a novel mechanism for inducing neuritogenesis in PC12 cells by activating the Ras-MAP kinase-Elk-1 cascade.

Adsorption removal of thiocyanate from aqueous solution by calcined hydrotalcite.

A hydrotalcite with Mg/Al molar ratio 2 was prepared by co-precipitation method and was characterized by XRD, TG/DTA, Zeta potential and BET surface area. The hydrotalcite was calcined at 500 degrees C, with the dehydration from interlayer, the dehydroxilation from the brucite-like layer and the decomposition of carbonate successively, transformed into the mixed oxide type. The removal of thiocyanate from aqueous solution by using the original hydrotalcite and calcined hydrotalcite (HTC-500) was investigated. The results showed that the thiocyanate adsorption capacity of calcined hydrotalcite was much higher than that of the original form. Calcined hydrotalcite was particularly effective at removing thiocyanate, and that the effective range of pH for the thiocyanate removal are between 5.5-10.0. The experimental data of thiocyanate removal fit nicely with Langmuir isotherm, and the saturated adsorption uptake was 96.2 mg SCN-/g HTC-500. The adsorption of thiocyanate by calcined hydrotalcite follows first-order kinetics. And the intercalation to the structure recovery for calcined hydrotalcite. But the presence of additional anions could affect the adsorption behavior of thiocyanate.

Cyclooxygenase-2 protein reduces tamoxifen and N-(4-hydroxyphenyl)retinamide inhibitory effects in breast cancer cells.

Approximately 30-40% of estrogen receptor alpha (ERalpha)-positive breast tumors express high levels of the cyclooxygenase-2 (COX-2) protein, and these high levels have been associated with a poorer prognosis in breast cancer patients. We speculate that high levels of COX-2 induce drug resistance in ERalpha-positive breast tumors, thus reducing the survival rate of patients with such tumors. Human breast cancer cell lines that express high levels of COX-2 are generally ERalpha negative. To determine whether COX-2 induces drug resistance, plasmids encoding the COX-2 gene were stably transfected into ERalpha-positive MCF-7 human breast cancer cells (MCF-7/COX-2). MCF-7/COX-2 cells were resistant to the selective estrogen receptor modulator tamoxifen but not to its analog, raloxifene. MCF-7/COX-2 cells were also resistant to the retinoid N-(4-hydroxyphenyl)retinamide (4-HPR) but not to its analog, all-trans retinoic acid. In contrast, the sensitivities of MCF-7/COX-2 cells to doxorubicin and paclitaxel were similar to those of the parental MCF-7 cells. We then determined which COX-2 product, prostaglandin E2 (PGE2) or prostaglandin F2alpha is involved in the COX-2-mediated drug resistance. PGE2, but not PGF2alpha, blocked the antiproliferative effects of tamoxifen and 4-HPR. Agonists that activate PGE2 receptors and their downstream kinase effectors, protein kinases A and C, also blocked the growth inhibitory effects of these drugs. Increased levels of Bcl-2 and Bcl-XL proteins have been reported in mammary tumors of COX-2 transgenic mice and in human colon cancer cell lines that have high levels of COX-2. However, we did not observe any changes in Bcl-2, Bcl-XL, or Bax expression induced by COX-2 or PGE2. Here we report the novel findings that COX-2 uses PGE2 to stimulate the activities of protein kinases A and C to induce selectively tamoxifen and 4-HPR resistance in ERalpha-positive breast cancer cells.

Multiple mechanisms of action of ZR2002 in human breast cancer cells: a novel combi-molecule designed to block signaling mediated by the ERB family of oncogenes and to damage genomic DNA.

The mechanism of action of ZR2002, a chimeric amino quinazoline designed to possess mixed EGFR tyrosine kinase (TK) inhibitory and DNA targeting properties, was compared to those of ZR01, a reversible inhibitor of the same class and PD168393, a known irreversible inhibitor of EGFR. ZR2002 exhibited 4-fold stronger EGFR TK inhibitory activity than its structural homologue ZR01 but was approximately 3-fold less active than the 6-acrylamidoquinazoline PD168393. It preferentially blocked EGF and TGFalpha-induced cell growth over PDGF and serum. It also inhibited signal transduction in heregulin-stimulated breast tumour cells, indicating that it does not only block EGFR but also its closely related erbB2 gene product. In contrast to its structural homologues, ZR2002 was capable of inducing significant levels of DNA strand breaks in MDA-MB-468 cells after a short 2 hr drug exposure at a concentration as low as 10 microM. Reversibility studies using whole cell autophosphorylation and growth assays in human breast cell lines showed that in contrast to its reversible inhibitor counterpart ZR01, ZR2002 induced irreversible inhibition of EGF-stimulated autophosphorylation in MDA-MB-468 cells and irreversible inhibition of cell growth. Moreover despite possessing a weaker binding affinity than PD168393, it induced a significantly more sustained antiproliferative effect than the latter after a pulse 2 hr exposure. More importantly, in contrast to ZR01 and PD168393, ZR2002 was capable of inducing significant levels of cell death by apoptosis in MDA-MB-468 cells. The results in toto suggest that the superior antiproliferative potency of ZR2002 may be due to its ability to induce a protracted blockade of receptor tyrosine kinase-mediated signaling while damaging cellular DNA, a combination of events that may trigger cell-killing by apoptosis.

Cyclooxygenase-2 is essential for HER2/neu to suppress N- (4-hydroxyphenyl)retinamide apoptotic effects in breast cancer cells.

We reported that HER2/neu reduces the sensitivity of breast cancer cells to N-(4-hydroxyphenyl)retinamide (4-HPR) by suppressing nitric oxide production. We show that HER2/neu uses Akt to induce cyclooxygenase-2 (COX-2) expression and that inhibition of Akt or COX-2 increases 4-HPR-induced apoptosis and nitric oxide production. Apoptosis induced by the 4-HPR and COX-2 inhibitor combination, although unaffected by an anti-HER2/neu antibody, was reversed by the COX-2 product prostaglandin E(2), indicating that COX-2 is a major mechanism by which HER2/neu suppresses 4-HPR apoptosis in breast cancer cells. Combining 4-HPR with COX-2 inhibitors may be a novel chemopreventive strategy against HER2/neu-overexpressing breast tumors.