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Introduction: The chemoresistance mechanism of diffuse large B-cell lymphoma (DLBCL) is still poorly understood, and patient prognosis remains unsatisfactory. This study aimed to investigate drug resistance mechanisms in non-germinal center B-cell-like (non-GCB) DLBCL. Methods: Doxorubicin (DOX)-resistant OCI-Ly3 cells were generated through long-term incubation of cells in a medium with gradually increasing DOX concentrations. The expression levels of genes related to drug metabolism were determined using a functional gene grouping polymerase chain reaction (PCR) array. Drug-resistant proteins were identified using bioinformatics, and molecular association networks were subsequently generated. The association and mechanism of key genes were determined using a dual-luciferase reporter assay System and chromatin immunoprecipitation (ChIP). The expression of drug-resistant genes and target genes was then measured using Western blotting and immunohistochemistry. The correlation between gene expressions was analyzed using Spearman’s rank correlation coefficient. Results: Using the PCR array, MDR1 was identified as the key gene that regulates DOX resistance in OCI-Ly3/DOX-A100, a non-GCB DLBCL cell line. The dual-luciferase reporter assay system demonstrated that MDR1 transcription could be inhibited by PRDM1. ChIP results showed that PRDM1 had the ability to bind to the promoter region (−1,132 to −996) of MDR1. In OCI-Ly3/DOX cells, NF-κB activity and PRDM1 expression decreased with an increase in drug-resistant index, whereas MDR1 expression increased with enhanced drug resistance. Immunohistochemical analysis revealed that relative MDR1 expression was higher than that of PRDM1 in human DLBCL tissue samples. A negative correlation was observed between MDR1 and PRDM1. Conclusion: In non-GCB DLBCL cells, NF-κB downregulates PRDM1 and thereby promotes MDR1 transcription by terminating PRDM1-induced transcriptional inhibition of MDR1. Such a mechanism may explain the reason for disease recurrence in non-GCB DLBCL after R-CHOP or combined CHOP with bortezomib treatment. Our findings may provide a potential therapeutic strategy for reducing drug resistance in patients with DLBCL.

Ganoderic acids (GAs), a group of highly oxygenated lanostane-type triterpenoids from the traditional Chinese medicinal mushroom Ganoderma lucidum, possessed significant pharmacological activities. Due to the difficulty in its genetic manipulation, low yield, and slow growth of G. lucidum, biosynthesis of GAs in a heterologous host is a promising alternative for their efficient production. Heterologous production of a GA, 3-hydroxy-lanosta-8,24-dien-26-oic acid (HLDOA), was recently achieved by expressing CYP5150L8 from Ganoderma lucidum in Saccharomyces cerevisiae, but post-modification of HLDOA to biosynthesize other GAs remains unclear. In this study, another P450 from G. lucidum, CYP5139G1, was identified to be responsible for C-28 oxidation of HLDOA, resulting in the formation of a new GA 3,28-dihydroxy-lanosta-8,24-dien-26-oic acid (DHLDOA) by the engineered yeast, whose chemical structure was confirmed by UPLC-APCI-HRMS and NMR. In vitro enzymatic experiments confirmed the oxidation of HLDOA to DHLDOA by CYP5139G1. As the DHLDOA production was low (0.27 mg/L), to improve it, the strategy of adjusting the dosage of hygromycin and geneticin G418 to respectively manipulate the copy number of plasmids pRS425-Hyg-CYP5150L8-iGLCPR (harboring CYP5150L8, iGLCPR, and hygromycin-resistant gene hygR) and pRS426-KanMx-CYP5139G1 (harboring CYP5139G1 and G418-resistant gene KanMx) was adopted. Finally, 2.2 mg/L of DHLDOA was obtained, which was 8.2 fold of the control (without antibiotics addition). The work enriches the GA biosynthetic enzyme library, and is helpful to construct heterologous cell factories for other GA production as well as to elucidate the authentic GA biosynthetic pathway in G. lucidum. KEY POINTS: • Another P450 gene responsible for GA's post-modification was discovered and identified. • One new GA, DHLDOA, was identified and produced via engineered yeast. • With the balance of the two CYP genes expression, DHLDOA production was significantly improved.

Rosiglitazone (ROSI), an oral antidiabetic agent, has been reported the anti-cancer properties recent years. In this paper, the potency of ROSI as a synergistic drug for vincristine (VCR) on resistant oral cancer cells was investigated. We found that ROSI potently enhanced the susceptibility of KB cells or KB/V cells to VCR in a dose manner and the synergy in KB/V cells was much more prominent than that in KB cells. The synergistic anti-proliferative effect of ROSI and VCR was associated with inhibition on tubulin polymerization, cell cycle arrest in G2/M phase and cell apoptosis induction, but has no effect on drug efflux-protein P-gp and was independent with PPARγ. The combination treatment of ROSI and VCR could regulate the PTEN/PI3K/AKT survival pathway with an upregulation of PTEN and down-regulation of p-AKT. The effect of G2/M phase arrest was associated with the upregulation of cyclin B1 and downregulation of p-cdc2. The apoptosis induction of ROSI and VCR was partly due to an upregulation of cleaved PARP and downregulation of Bcl-2/Bax ratio. In addition, combination treatment of ROSI and VCR had also shown anti-angiogenic effect by suppressing the migration and blocking the capillary tube formation of HUVECs. More importantly, this combination treatment induced an acceptably weak cytotoxicity in human normal HL-7702 cells, GES-1 cells and HUVECs. Taken together, ROSI may be used as a potential compound for combinatorial therapy or as a complement to VCR for treatment on oral cancer, especially on that have acquired resistance to VCR therapy.

The nerve growth factor (NGF) is a growth factor that belongs to the neurotrophin family. NGF has two structurally different receptors, the p75 neurotrophin receptor (p75NTR) and the tropomyosin-related kinase A (TrkA). Interaction of NGF with its receptors regulates a variety of physiological processes of neuronal system. Recent studies have shown that NGF and its receptors were involved in the regulation of tumourigenesis by either supporting or suppressing tumor growth depending on the tumor types. This review summarizes the current views of NGF and its receptors in tumorigenesis and cancer pain.

Compared with normal reflecting scanning transform Spectrometry, cube-based Spectrometr is a key component in the time-based modulation interference spectrometer, it have more compact structure ,using less accessory , easy to fix up , more steadily and more practicality . Calculations on optical path difference (OPD) of spectrometry play an important role in analyzing and improving of the structure. Following the law of Malus and the geometrical relationship of model, get the formula of OPD and the affective factors .The calculation results demonstrate that OPD is closely related to the tilted angel of rotating reflector , the size of cube reflector and the refractive index of reflector. And this kind of spectrometry has the character of high resolution, especial in some spectrum.

In order to explore micro-beam relaxation dynamics of MEMS, the beam deflection relaxation expression considering air slide-film damping effect was educed based on Euler–Bernoulli equation with boundary conditions of two hinged ends. The beam deflection relaxation process under over damping, critical damping and under damping was calculated used Maple. The relaxation simulation data of micro-beam with two hinged ends used ANSYS demonstrate that relaxation process conform to theoretical calculation and relaxation period of under damping relaxation approximate constant when damping coefficient is small, but increase significantly when damping coefficient is large.

A ligustrazine (TMP) derivative, (E)-2-(2, 4-dimethoxystyryl)-3,5,6-trimethylpyrazine (DLJ14) was synthesized for the improvement of low bioavailability and short half-life of ligustrazine. We have observed potential reversal effects of DLJ14 on adriamycin (Adr)-resistant human myelogenous leukemia cells (K562/A02) and Adr-resistant human breast cancer cells (MCF-7/A) in vitro or in vivo in previous studies. The aim of the present study was to investigate the underlying molecular mechanism of DLJ14 and Adr combination treatment on Adr-resistant human breast cancer. Inhibition of cancer cell growth was estimated by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell cycle distribution was analyzed by flow cytometry and apoptosis determined using Annexin V-FITC/propidium iodide (PI) double staining and Hoechst 33258 nuclear staining. The expression of proteins in the epidermal growth factor receptor (EGFR)/phosphatidylinositol-3 kinase (PI3K)/Akt survival pathway and mitochondrial-mediated apoptosis pathway were measured by Western blotting analysis. Results showed that DLJ14 and Adr combination treatment exhibited stronger inhibition of the survival of MCF-7/A cells than Adr treatment alone. This effect might be associated with its role in cell cycle arrest and apoptosis induction. DLJ14 combined with Adr induced cell cycle arrest in the G2/M-phase by activating p21(wafl /cip1) and p53 in mitochondria and increased cleavage of caspase-9 and caspase-3, and Bax/Bcl-2 ratio. Mitochondrial membrane potential (MMP) disruption and cytochrome c (Cytc) release from mitochondria to cytosol suggested that apoptosis induction might be mediated by the mitochondrial pathway. Moreover, the combination of DLJ14 and Adr could down-regulate the expression of EGFR, p-EGFR, PI3K, and p-Akt in MCF-7/A cells. Overall, DLJ14 and Adr combination treatment may inhibit proliferation of Adr-resistant human breast cancer cells through inhibition of the EGFR/PI3K/Akt survival pathway and induction of apoptosis via the mitochondrial-mediated apoptosis pathway.

Diffuse large B cell lymphoma (DLBCL) represents the most common subtype of non-Hodgkin lymphoma and accounts for approximately 30 % of newly diagnosed lymphoid neoplasms in Western countries, and 40–50 % in China. A better understanding of the biology of DLBCL is needed for the development of potential therapeutic agents that target specific intracellular pathways. In this study, expression of the important components of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway and their clinical significance were investigated in 73 DLBCL cases. The effect of rituximab alone or combined with the PI3K/AKT/mTOR pathway inhibitor rapamycin was further evaluated in the DLBCL cell lines. A total of 73 patients were identified, including 45 men and 28 women aged 18 to 78 years (median age 50 years). Of these patients, p-AKT was positive in 40 cases (54.8 %), p-p70S6K in 34 cases (46.6 %), and p-4E-BP1 in 33 cases (45.2 %). Activation of the PI3K/AKT/mTOR pathway was related to poor disease outcome in DLBCL patients treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) but not in those treated with rituximab-CHOP. Rituximab combined with rapamycin synergically downregulated the PI3K/AKT/mTOR signaling pathway. Western blot analysis revealed a baseline activation status of the PI3K/AKT/mTOR pathway in DLBCL cell lines, with high levels of p-AKT, p-mTOR, in addition to downstream molecules p-p70S6K and p-4E-BP1. The results indicate that the PI3K/AKT/mTOR pathway is a potentially important signaling route and an unfavorable prognostic factor for DLBCL. Patients with PI3K/AKT/mTOR activation experience a more rapidly deteriorating clinical course with poor treatment response and decreased survival time. Addition of rituximab could downregulate PI3K/AKT/mTOR activation, reversing its negative effect on chemotherapy-treated patients. In addition, our results indicate that the combination of rituximab and inhibition of the activated PI3K/AKT/mTOR pathway could be a promising target for DLBCL therapeutic intervention in the future.

To the Editor: Spinocerebellar ataxia (SCA) is an inherited disorder of brain function characterized by progressive incoordination of gait and is often associated with poor coordination of hands, speech, and eye movements. It is a slowly progressive disease that gradually worsens over a period of years. Zolpidem is a nonbenzodiazepine sedative in the imidazopyridine class and is chemically distinct from other sedatives. It is a short-acting hypnotic with a selective agonist effect for γ-aminobutyric acid (GABA) type A receptors in the brain. It was considered originally by physicians as almost devoid of abuse and dependence potential. Intriguingly, aside from its hypnotic effect, zolpidem has been shown to improve catatonia,1 aphasia,2 Parkinson's disease,3 and ataxia.4 However, reports of zolpidem abuse or dependence are increasing,5,6 and more attention should be paid in terms of zolpidem withdrawal. We report a patient with SCA who took zolpidem for movement difficulties initially, developed dependence on high-dose zolpidem treatment, and encountered serious withdrawal symptoms. We also review the literature on the possible mechanism for the effect of zolpidem on SCA. Case report. Ms A, a 40-year-old married woman, was referred in 2009 for psychiatric consultation due to high-dose zolpidem use. She was diagnosed with SCA type IV at age 35 years with initial symptoms of unsteady gait and mild slurred speech. Her father and brother were also afflicted with SCA. This time, she was admitted via emergency department to our neurology department because of loss of consciousness. Generalized seizure lasted for 1 minute at home, and initial management at the emergency department with phenytoin intravenous drip terminated further progression. Toxicology testing detected no plasma alcohol, whereas plasma benzodiazepine level was 64.80 ng/mL. She claimed she had abused triazolam and alcohol during early adulthood due to insomnia. Other illicit substance use was denied. She had started taking zolpidem 3 years earlier for insomnia, and, paradoxically, zolpidem relieved her ataxia and spasticity. She recalled being able to move her arms and turn her trunk more easily, although the improvement lasted only around 1 hour after taking zolpidem. The dose of zolpidem was gradually escalated by the patient to reach optimal effect. The dose usually amounted to 1,000 mg/d for the past year. Nausea, palpitation, jitters, hand tremor, and perspiration were noted if she did not take enough zolpidem. She was bedridden due to SCA and was cared for by her husband. Although she consumed high doses of zolpidem, her husband tried to cater to all her needs out of sympathy. Zolpidem had been prescribed from different physicians. Withdrawal seizures were noted several times if her supply of zolpidem fell short. Ms A was detoxified by taper of zolpidem gradually over 2 weeks. We prescribed trazodone 100 mg before sleep and diazepam 20 mg/d and propranolol 30 mg/d for anxiety. No seizure attack was noted during hospitalization. After this 2-week hospitalization, she was referred to the psychiatric clinic for further management. The imidazopyridine hypnotic zolpidem binds preferably to the α1 subtype of the benzodiazepine receptor, which is part of GABAA receptor complex. This highly accounts for its sedative effect, whereas the anxiolytic action of benzodiazepines appears to be mediated by receptors that contain the α2 subunit.7 Zolpidem at high doses might lose its selectivity on α1 subunits and bind to lower-affinity α2 units, leading to an anxiolytic effect. Thus, high-dose zolpidem may have a paradoxical effect for alleviating anxiety, and abrupt discontinuation would produce withdrawal symptoms such as palpitation, anxiety, tremor, or seizure similar to those seen with benzodiazepine withdrawal. There is no definite treatment that can prevent or slow the progression of SCA. Clauss et al4 reported transient improvement of SCA with zolpidem in 4 cases. Single photon emission computed tomography demonstrated that GABAergic function may be decreased in the cerebral cortex, thalamus, striatum, and cerebellum in patients with SCA.8 Zolpidem has been shown to mildly improve catatonia, aphasia, and Parkinson's disease.9 Such motor improvement may be due to selective inhibition by zolpidem of GABAergic inhibitory neurons in the internal globus pallidus and substantia nigra pars reticulata, resulting in activation of the thalamus and cerebral cortex.9 Positron emission tomography imaging also has shown normalized tracer uptake in the left thalamus and cerebellum after treatment with zolpidem.4 Our case further corroborates that zolpidem has a mode of action apart from hypnotic properties. To our knowledge, this is the first case report concerning high-dose zolpidem withdrawal seizure in a patient with SCA. We should be more cautious in prescribing zolpidem to patients with past drug abuse or dependence to prevent unwanted consequence. Further investigation of the pharmacologic efficacy of zolpidem in SCA might be needed.