HIV-negative plasmablastic lymphoma: report of 8 cases and a comprehensive review of 394 published cases

Background

Human immunodeficiency virus (HIV)-negative plasmablastic lymphoma (PBL) is a rare entity of diffuse large B-cell lymphoma (DLBCL). The clinicopathological features of and optimal treatment for HIV-negative PBL remain largely unknown.

Methods

To gain insight into this distinct lymphoma, we summarized the clinicopathologic characteristics of 8 unpublished HIV-negative PBLs and performed a comprehensive review of 394 published cases.

Results

Of the 8 unpublished PBLs, the median patient age was 53.0 years. Four patients presented with stage IV disease. All 8 patients showed a plasma cell-like immunophenotype. Of the six patients who received anthracycline-based chemotherapy, including two who received bortezomib, three patients achieved a continuous complete response, two patients died due to disease progression, and one patient was lost to follow-up. The other two patients achieved continuous complete response after receiving chemotherapy combined with radiotherapy and surgery. Of the 402 patients, the majority were male, with a mean age of 58.0 years. EBV infection was detected in 55.7% of the patients. The median survival times of the patients who received CHOP or CHOP-like regimens and intensive regimens were not reached and 23.0 months, respectively, and the intensive regimen did not improve the survival outcome (P=0.981). Multivariate analysis showed that EBER remained the only independent factor affecting overall survival (OS).

Conclusion

HIV-negative PBL is a distinct entity with a predilection for elderly and immunosuppressed individuals. Intensive chemotherapy had no apparent survival benefits over the CHOP regimen in terms of OS; the prognosis of this disease is poor with current chemotherapy methods, and treatment remains a challenge.

linc01088 promotes cell proliferation by scaffolding EZH2 and repressing p21 in human non-small cell lung cancer

AIMS

Non-small cell lung cancer (NSCLC), characterized by extensive metastasis and poor prognosis, is the most common type of lung cancer. Dysregulation of certain lncRNAs is known to be linked to the tumorigenesis of NSCLC. However, the specific roles in NSCLC for many other lncRNAs, such as linc01088, remain largely unknown.

MATERIALS AND METHODS

The expression patterns of linc01088, p21 and EZH2 were examined both in NSCLC tissues and cell lines using RT-qPCR assay. CCK-8, colony formation, immunofluorescence staining, and flow cytometry assays were employed to evaluate the effects of linc01088 on NSCLC cell proliferation properties. RNA immunoprecipitation (RIP) assay was performed to determine the direct binding relationship between linc01088 and zeste homolog 2 (EZH2). Western blot and RT-qPCR analysis were performed to assess p21 level within knockdown of either linc01088 or EZH2. Nude mouse subcutaneous NSCLC models were constructed for further validating the effects and mechanisms of linc01088 in vivo.

KEY FINDINGS

linc01088 and EZH2 were highly expressed both in NSCLC tissues and cell lines. Knockdown of linc01088 suppressed the proliferation of NSCLC cells, and prolonged the G1 phase while shortened S and G2-M phases. RIP assay revealed the direct binding relationship between linc01088 and EZH2. Knockdown of either linc01088 or EZH2 induced up-regulation of p21 expression, which subsequently inhibited the tumor growth.

SIGNIFICANCE

We demonstrated that linc01088 could promote cell proliferation via binding with EZH2 to repress p21, which aggravates the tumorigenesis of NSCLC. Therefore, linc01088 might be a potential oncogene and target for novel anti-tumor therapies.

Cathepsin L interacts with CDK2-AP1 as a potential predictor of prognosis in patients with breast cancer

Cathepsin L (CTSL) is a lysosomal acid cysteine protease that has been implicated in tumorigenesis and malignant progression. In the present study, the role of CTSL in tumorigenesis and prognosis of breast cancer was evaluated. The prognostic value of CTSL was analyzed using immunohistochemistry in patients with breast cancer, as well as online microarray datasets. CTSL expression was knocked down in the breast cancer cell line T-47D using RNA interference. MTT and colony formation assays were performed to assess the role of CTSL in the proliferation of breast cancer cells. Cell cycle progression and apoptosis were measured using flow cytometry. A physical interaction of CTSL and cyclin dependent kinase 2 associated protein 1 (CDK2-AP1) was determined using a glutathione S-transferase pull-down assay. Endogenous CTSL expression was high in breast cancer cells and exhibited an inverse association with CDK2-AP1 expression; aberrant expression of CTSL in breast cancer tissues predicted an improved clinical outcome and prognosis. In addition, CTSL knockdown decelerated the progression of breast cancer cells by arresting cell cycle progression and increasing apoptosis. Thus, CTSL may be a potential therapeutic target for treating patients with breast cancer.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。

Cyclin-dependent kinase 1-mediated phosphorylation of YES links mitotic arrest and apoptosis during antitubulin chemotherapy

YES is a member of the SRC family kinase (SFK) group of non-receptor tyrosine kinases, which are implicated in multiple key cellular processes involved in oncogenesis. Antitubulin agents have been widely used as chemotherapeutics for cancer patients and these drugs arrest cells in mitosis, leading to subsequent cell death. In the present study, we define a mechanism for phospho-regulation of YES that is critical for its role in response to antitubulin agents. Specifically, we found that YES is phosphorylated at multiple sites on its N-terminal unique domain by the cell cycle kinase CDK1 during antitubulin drug-induced mitotic arrest. Phosphorylation of YES occurs during normal mitosis. Deletion of YES causes arrest in prometaphase and polyploidy in a p53-independent manner. We further show that YES regulates antitubulin chemosensitivity. Importantly, mitotic phosphorylation is essential for these effects. In support of our findings, we found that YES expression is high in recurrent ovarian cancer patients. Finally, through expression profiling, we documented that YES phosphorylation affects expression of multiple cell cycle regulators. Collectively, our results reveal a previously unrecognized mechanism for controlling the activity of YES during antitubulin chemotherapeutic treatment and suggest YES as a potential target for the treatment of antitubulin-resistant cancer.

Roles of flotillins in tumors

The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer patients. The lipid raft marker proteins, flotillin-1 and flotillin-2, were first found in goldfish retinal ganglion cells during axon regeneration. They have since been found in a variety of cells, mainly on the inner surface of cell membranes, and not only act as a skeleton to provide a platform for protein-protein interactions, but also are involved in signal transduction, nerve regeneration, endocytosis, and lymphocyte activation. Previous studies have shown that flotillins are closely associated with tumor development, invasion, and metastasis. In this article, we review the functions of flotillins in relevant cell processes, their underlying mechanisms of action in a variety of tumors, and their potential applications to tumor molecular diagnosis and targeted therapy.

The role of aldehyde dehydrogenase 1A1 in B-cell non-Hodgkin's lymphoma

Previously we showed that aldehyde dehydrogenase 1A1 (ALDH1A1) is a new mediator for resistance of DLBCL to CHOP and a facility predictor of clinical prognosis. In the present study, knockdown and inhibitor of ALDH1A1 were applied to identify the role of ALDH1A1 in Raji cells. CCK-8 and clone formation assay were applied to determine the CHOP sensitivity and clone formation ability. Caspase colorimetric assay and Annexin V/FITC staining was performed to determine the degree of apoptosis. Western blot analysis was used to detect the NF-κB/STAT3 signaling proteins and apoptotic-associated proteins. Real-time quantitative PCR (RT-PCR) was used to identify the differential expression of ALDH1A1 between NHL patients and healthy donors. We demonstrated that inhibition of ALDH1A1 increased the sensitivity of Raji cells to CHOP, as indicated by increased cytotoxicity, reduced clonogenicity, activated caspase-3/-9, decreased NF-κB/STAT3 signaling and increased pro-apoptosis signaling, ad increased apoptosis rate. Moreover, we found high ALDH1A1 expression was associated with poor prognosis in NHL patients. Our data revealed the critical role of ALDH1A1 in NHL and provides a theoretical basis for the use of ALDH1A1 inhibitors in NHL patients.

Endoplasmic Reticulum Stress Promotes Autophagy and Apoptosis and Reduces Chemotherapy Resistance in Mutant p53 Lung Cancer Cells

BACKGROUND/AIMS

Lung cancer (LC) continues to be one of the most prevalent cancers around the world. During this study we aimed to investigate the involvement of endoplasmic reticulum stress (ERS) in autophagy, apoptosis, and chemotherapy resistance of mutant p53 LC cells.

METHODS

Immunohistochemistry was employed to help determine the p53 mutation status of cancer cells from 92 primary LC patients, who were subsequently assigned to either the mutant p53 (n = 39) or wild-type p53 group (n = 53).

RESULTS

Mutant p53 cells exhibited increased expression of the C/EBP homologous protein (CHOP), glucose-regulated protein 78 (GRP78), and inositol-requiring enzyme-1α (IRE1α). The Mutant p53 cells were also found to be sensitive to chemotherapy and displayed decreased expression of PI3K, Akt, and mTOR. The mutant p53 cell lines were treated with tunicamycin to induce ERS and rapamycin in order to inhibit mTOR. Both agents increased the expression of CHOP, GRP78, IRE1α, LC3-II/LC3-I, Atg5, Atg7, caspase-3, caspase-12, cleaved caspase-3, cleaved caspase-12, as well as decreases in cell proliferation as well as the expression levels of PI3K, Akt, and mTOR. Enhanced levels of cell apoptosis and reduced chemotherapy resistance were also detected.

CONCLUSION

The findings of our study suggest that ERS promotes autophagy and apoptosis, while acting to reduce chemotherapy resistance in mutant p53 LC cells by downregulating the PI3K/Akt/mTOR signaling pathway.

TUSC3 induces autophagy in human non-small cell lung cancer cells through Wnt/β-catenin signaling

We investigated the effects of tumor suppressor candidate 3 (TUSC3) on autophagy in human non-small cell lung cancer (NSCLC) cells. A total of 118 NSCLC patients (88 males and 30 females) who underwent surgery at our institute were enrolled in the study. Immunohistochemical analysis revealed that TUSC3 protein expression was lower in NSCLC specimens than adjacent normal tissue. Correspondingly, there was greater methylation of TUSC3 in NSCLC than adjacent normal tissue. After transient transfection of A549 NSCLC cells with constructs designed to up-regulate or down-regulate TUSC3 expression, we analyzed the effects of inhibiting the Wnt pathway (XAV939) and autophagy (chloroquine, CQ) on the behavior of NSCLC cells. We also performed TOP/FOP-Flash reporter assays, MTT assays, Annexin V-FITC/propidium iodide staining, and acridine orange staining to evaluate Wnt/β-catenin signaling, cell proliferation, apoptosis, and autophagy, respectively. Expression of Wnt/β-catenin pathway components and autophagy-related proteins was analyzed using qRT-PCR and Western blotting. We found that TUSC3 inhibited cell proliferation and promoted both apoptosis and autophagy in A549 cells. In addition, TUSC3 increased expression of autophagy-related proteins. It also increased expression of Wnt/β-catenin signaling pathway components and promoted nuclear transfer of β-catenin, resulting in activation of Wnt/β-catenin signaling. TUSC3 thus induces autophagy in human NSCLC cells through activation of the Wnt/β-catenin signaling pathway.

Silencing platelet-derived growth factor receptor-β enhances the radiosensitivity of C6 glioma cells in vitro and in vivo

Platelet-derived growth factor receptor (PDGFR)-β is an important tyrosine kinase and its downregulation has been reported to alter the radiosensitivity of glioma cells, although the underlying mechanism is unclear. In order to investigate the effect of PDGFR-β on the radiosensitivity of glioblastoma, the present study transfected C6 glioma cells with a PDGFR-β-specific small interfering (si)RNA expression plasmid, and downregulation of the expression of PDGFR-β in C6 glioma cells was confirmed by western blotting and immunohistochemical analysis. Clone formation assays and xenograft growth curves demonstrated that PDGFR-β-siRNA enhanced the radiosensitivity of C6 glioma cells in vitro and in vivo. Furthermore, MTT and xenograft growth curves demonstrated that PDGFR-β-siRNA inhibited the proliferation of C6 glioma cells in vitro and in vivo, and terminal deoxynucleotidyl transferase dUTP nick end-labeling and immunohistochemical analyses demonstrated that PDGFR-β-siRNA induced apoptosis and inhibited the expression of Ki-67, cyclin B1 and vascular endothelial growth factor in C6 glioma cell xenografts. Taken together, these results suggested that PDGFR-β may be used as a target for the radiosensitization of glioblastoma.

Multiple Roles of WNT5A in Breast Cancer

Breast cancer is one of the most common malignant tumors of women. Modern combinatorial therapeutic regimens can reduce patient tumor burdens to undetectable levels, yet in many cases these tumors will relapse. Understanding of breast cancer biology, developing more potent therapeutic approaches, and overcoming resistance are of great importance. WNT5A is a non-canonical signaling member of the WNT family. Its role in breast cancer still remains unclear. Most of the evidence shows that WNT5A is a suppressor in breast cancer and loss of its expression is associated with poor prognosis, while some evidence suggests the tumorigenicity of WNT5A. WNT signaling molecules are potent targets for treatment of cancer. Therefore, understanding the role of WNT5A in breast cancer may provide new ideas and methods for breast cancer treatment. We review the evidence concerning WNT5A and breast cancer involving the signaling pathways and the molecular-targeted therapy of WNT5A. Our results show that the role WNT5A plays depends on the availability of key receptors and intercellular interactions among different cell types.

Pretreatment of Shaoyao Gancao Decoction () alters pharmacokinetics of intravenous paclitaxel in rats

OBJECTIVE

To investigate the effect of Shaoyao Gancao Decoction (, SGD) on the pharmacokinetics of intravenously administered paclitaxel in rats.

METHODS

Paclitaxel was intravenously administered to rats (3 mg/kg) with or without the concomitant administration of SGD (752 mg/kg, a single day or 14 consecutive days pretreatment). The paclitaxel in the serum was quantified using a simple and rapid ultra performance liquid chromatography (UPLC) method for the pharmacokinetic study. The pharmacokinetic parameters were calculated via a non-compartment model using the computer program DAS 2.0.

RESULTS

The pharmacokinetic parameters of paclitaxel were significantly altered in response to 14 consecutive days of pretreatment with SGD. The area under the curve (AUC_0-t, from 4 820±197 to 4 205±186 ng·mL^-1·^-1) and AUC_0-∞ (from 5 237±280 to 4 514±210 ng·mL^-1·^-1) significantly decreased in response to the 14-day pretreatment with SGD. The values of V_dss (L/kg) were 10.74±1.08 and 9.35±0.49, those of CL (L/kg) were 0.67±0.03 and 0.57±0.03 and the t_1/2 (h) values were 11.17±0.84 and 11.32±0.93, respectively, for the 14-day SGD pretreatment and intravenous paclitaxel alone. The AUC_0-t and AUC_0-∞ values decreased by 13% and 14% (P<0.01), respectively. The area under the curve decreased signifificantly (P<0.01), and the total clearance increased by 1.2-fold (P<0.01), after 14 consecutive days of pretreatment with SGD. A single-day pretreatment with SGD did not signifificantly affect the pharmacokinetic parameters of paclitaxel.

CONCLUSIONS

SGD administration for 14 consecutive days increased the metabolism of paclitaxel, while a 1-day pretreatment had little effect. The results would contribute important information to the study on interaction between Chinese medicines and chemotherapy and also help to utilize SGD better in the adjunctive therapy of cancer patients.

ALDH1A1 mediates resistance of diffuse large B cell lymphoma to the CHOP regimen

Although there have been substantial advances in our knowledge of the resistance of diffuse large B cell lymphoma (DLBCL) to chemotherapy, there are few efficient treatment strategies for recurrent/refractory DLBCL. The aim of this study was to investigate the role of aldehyde dehydrogenase (ALDH) 1A1 in the resistance of diffuse large B cell lymphoma to the chemotherapeutic mixture consisting of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). The involvement of ALDH1A1 in DLBCL was elucidated by knockdown and pharmacologic inhibition; Cell Counting Kit-8 (CCK-8) and clone formation assays were used to determine its role in CHOP sensitivity and clone formation ability. Caspase colorimetric assay was used to measure the extent of apoptosis. Western blot analysis was used to measure signal transducer and activator of transcription 3 (STAT3)/nuclear factor kappa B (NF-κB) signaling proteins, and quantitative real-time PCR (RT-PCR) was used to measure the differential expression of ALDH1A1 of DLBCL patients and healthy donors. ALDH1A1 showed a 5.64-fold higher expression in malignant B cells than in normal B cells. Diethylaminobenzaldehyde (DEAB) decreased the half maximal inhibitory concentration (IC50) of the CHOP regimen in Farage cells from 344.78 ± 65.75 to 183.88 ± 49.75 ng/ml (P = 0.004). Both knockdown and inhibition of ALDH1A1 reduced clonogenicity, increased caspase-3/caspase-9 activity, and attenuated the phosphorylation status of STAT3/NF-κB. The prognosis of patients with a high level of ALDH1A1 expression was poor compared with that of patients with low levels of expression (P = 0.044). ALDH1A1 is a new mediator for resistance of DLBCL to CHOP; it is a predictor of clinical prognosis and may serve as a potential target to improve chemotherapy responsiveness of human DLBCL.

[Metabolic changes in abnormal savda patients with different types of tumor: a clinical observation]

OBJECTIVE

To explore in vivo metabolic changes in abnormal savda patients with different types of tumor.

METHODS

A total of 142 abnormal savda patients with common cancer types were enrolled in this study, and 50 healthy volunteers were recruited as the control group. For each sample, the H Nuclear Magnetic Resonance (NMR) based metabonomic analysis was performed. The free attenuation signal was computed subsection integral. Data obtained were analyzed by the Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA).

RESULTS

Compared with the control group, leucine, isoleucine, valine, histidine, phenylalanine, tyrosine, alanine, creatine, lactic acid, inositol, alpha-and beta-glucose, unsaturated lipids, very low density lipoprotein (VLDL) significantly decreased (P <0.05), while glycoprotein and carnitine significantly increased (P <0. 05) in the abnormal Savda group.

CONCLUSION

Abnormal savda patients with different types of tumor had similar metabonomics changes.

Facile synthesis of monodispersed Fe2O3 nanoparticles and its cellular uptake and cytotoxicity studies

Monodispersed Fe2O3 nanoparticles were fabricated with a facile hydrothermal synthetic route by using Fe(NO3)3 x 7H2O and glycin as reagents without using any templates or surfactants in this report. The prepared nanoparticles were pure hexagonal alpha-Fe2O3 particles from the characterization of XRD analysis. The Fe2O3 nanoparticles with a narrow size distribution and a mean diameter of - 50 nm can be well dispersed in water. Cellular uptake and cellular responses of the as-prepared Fe2O3 nanoparticles for human cancer cells have been studied. The Fe2O3 nanoparticles can be readily uptake by the cells, but no obvious oxidative damages in the cells can be detected after an incubation of 24 h. Also the treatment of Fe2O3 nanoparticles did not induce any changes in cell viability and cell proliferation. These results demonstrate that the Fe2O3 nanoparticles prepared with our method are remarkably biocompatible, which can be used as a substitute with high biosafety for the present iron oxides materials in different kinds of applications.

Case-control study of single nucleotide polymorphisms of PSCA and MUC1 genes with gastric cancer in a Chinese

AIMS

A case-control study of 300 gastric cancer patients and 300 controls was conducted to investigate whether the polymorphisms rs2294008 in PSCA and rs2070803 in MUC1 might be associated with risk of gastric cancer in a Chinese population.

METHODS

Single nucleotide polymorphisms (SNPs) were genotyped using the Sequenom MassARRAY platform.

RESULTS

The data showed that the rs2294008 TT genotype increased gastric cancer risk to an adjusted odds ratio (OR) of 2.26 (95%CI 1.25-4.07), TC to 1.72 (95%CI 1.23-2.42) and TC/TT to 1.81 (95% CI 1.31-2.50), while the rs2070803 GA genotype was associated with a decrease in risk to an adjusted OR of 0.42 (95% CI 0.28-0.62) and rs2070803 GA / AA to 0.46 (95% CI 0.32-0.67). Further stratification analysis revealed that rs2294008 in PSCA consistently increased risk of both intestinal and diffuse-type gastric cancers. The effect of rs2070803 in MUC1 was noteworthily also consistent with both subtypes.

CONCLUSIONS

Our study suggested rs2294008 in the PSCA gene to be associated with increased risk of gastric cancer and rs2070803 in MUC1 to play a protective role in a Chinese population.

Predictive value of thymidylate synthase expression in gastric cancer: a systematic review with meta-analysis

PURPOSE

The relationship between thymidylate synthase (TS) expression and outcomes in gastric cancer (GC) patients remains controversial, although most studies reported poor survival and reduced response to fluoropyrimidine were related to high TS in tumors. We carried out a systematic review of the literature with meta-analysis to estimate the predictive value of TS expression from published studies.

METHODS

We identified 24 studies analysing the outcome data in gastric cancer stratified by TS expression. Effect measures of outcome were hazard ratios (HRs) for overall survival (OS) and event-free survival (EFS), or the odds ratio (OR) for overall response rate (ORR). HRs and ORs from these eligible studies were pooled using random-effects meta- analysis.

RESULTS

Fifteen studies investigated outcomes in a total of 844 patients with advanced GC, and nine studies investigated outcomes in a total of 1,235 patients with localized GC undergoing adjuvant therapy. Meta- analysis of estimates showed high TS expression was significantly associated with poor OS in the advanced setting (HR: 1.43, 95%CI: 1.08 - 1.90), and poor EFS in the adjuvant setting (HR: 1.53, 95%CI: 1.01 - 2.32). Subgroup analysis demonstrated TS expression to have even greater value in predicting OS, EFS and ORR in advanced GC patients treated with fluoropyrimidine monotherapy (HR for OS: 2.32, 95%CI: 1.53 - 3.50; HR for EFS: 1.76, 95%CI: 1.19 - 2.60; OR for ORR: 0.32, 95%CI: 0.11 - 0.95).

CONCLUSION

High levels of TS expression were associated with a poorer OS for advanced GC patients compared with low levels. In the adjuvant setting, high TS expression was also associated with a worse EFS. Additional studies with consistent methodology are needed to define the precise predictive value of TS.

Effect of eIF3a on response of lung cancer patients to platinum-based chemotherapy by regulating DNA repair

PURPOSE

The purpose of this study is to test the hypothesis that eIF3a may regulate the expression of DNA repair proteins which, in turn, affects response of lung cancer patients to treatments by DNA-damaging anticancer drugs.

EXPERIMENTAL DESIGN

Immunohistochemistry was used to determine the expression of eIF3a in 211 human lung cancer tissues followed by association analysis of eIF3a expression with patient's response to platinum-based chemotherapy. Ectopic overexpression and RNA interference knockdown of eIF3a were carried out in NIH3T3 and H1299 cell lines, respectively, to determine the effect of altered eIF3a expression on cellular response to cisplatin, doxorubicine, etoposide (VP-16), vincristine, and vinblastine by using MTT assay. The DNA repair capacity of these cells was evaluated by using host-cell reactivation assay. Real-time reverse transcriptase PCR and Western Blot analyses were carried out to determine the effect of eIF3a on the DNA repair genes by using cells with altered eIF3a expression.

RESULTS

eIF3a expression associates with response of lung cancer patients to platinum-based chemotherapy. eIF3a knockdown or overexpression, respectively, increased and decreased the cellular resistance to cisplatin and anthrocycline anticancer drugs, DNA repair activity, and expression of DNA repair proteins.

CONCLUSIONS

eIF3a plays an important role in regulating the expression of DNA repair proteins which, in turn, contributes to cellular response to DNA-damaging anticancer drugs and patients' response to platinum-based chemotherapy.

Clinical significance of mTOR and p-mTOR protein expression in human colorectal carcinomas

AIM

To investigate the significance of mammalian target of rapamycin (mTOR) and its active form, p-mTOR in colorectal carcinomas.

METHODS

Immunohistochemistry was used to detect the expression of mTOR and p-mTOR proteins in 108, 40 and 40 tissue samples from colorectal carcinoma, normal colonic mucosa and adenomatous polyps samples, respectively. The correlation of mTOR and p-mTOR expression with clinicopathological characteristics of colorectal carcinoma was analyzed.

RESULTS

The positive rates of mTOR and p-mTOR were significantly higher in colorectal carcinoma (61.1% and 61.1%, respectively, p<0.05) than in normal colonic mucosa (7.5% and 2.5%) and adenomatous polyps (27.5% and 20%). Overexpression of total mTOR protein was significantly associated with T1/T2 stage tumors, lymph node metastasis, distal metastasis) and degree of differentiation. p-mTOR overexpression was additionaly linked with degree of differentiation and TNM stage.

CONCLUSION

The overexpression of mTOR and p-mTOR may play important roles in colorectal carcinogenesis with relations to the degree of differentiation, invasiveness and metastasis.

[Molecular mechanism of proliferation of human breast cancer cell MCF-7 inhibited by E1A gene]

OBJECTIVE

To explore the molecular mechanism of proliferation inhibition of human breast cancer cell MCF-7 regulated by E1A gene.

METHODS

E1A gene was transfected into MCF-7 cells by liposome reagents. RT-PCR and Western blot were used to detect E1A mRNA and protein expression and HER-2 mRNA in MCF-7. The proliferation and colony formation of MCF-7 were measured by 3-(4,5-dinmethylthiahiazo-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and soft agar formation assay. The apoptosis of MCF-7 cells regulated by E1A expression was examined by flow cytometry.

RESULTS

E1A was not endogenously expressed in MCF-7. E1A expression in MCF-7 could significantly decrease HER-2 mRNA and protein expression. Flow cytometry indicated that the apoptosis of MCF-7 could be induced by E1A. Meanwhile, E1A gene could significantly inhibit MCF-7 proliferation and colony formation in soft agar.

CONCLUSION

E1A gene can decrease HER-2 expression and induce the apoptosis of human breast cancer cell MCF-7, and inhibit the proliferation and colony formation of MCF-7.

[Correlation of cyclooxygenase-2 expression to P-glycoprotein expression in B-cell non-Hodgkin's lymphoma]

BACKGROUND & OBJECTIVE

The overexpression of P-glycoprotein (P-gp) plays an important role in the chemoresistance of relapsed lymphoma. It is up-regulated in a cyclooxygenase-2 (COX-2)-dependent manner. This study was to observe the expression and correlation of COX-2 and P-gp in B-cell non-Hodgkin's lymphoma (B-NHL), and to investigate their correlations to clinicopathologic features of B-NHL.

METHODS

The expression of COX-2 and P-gp in 43 specimens of naive B-NHL and 27 specimens of relapsed B-NHL were detected by SP immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The positive rates of COX-2 and P-gp were significantly lower in naive B-NHL than in relapsed B-NHL (23.3% vs. 74.1%, 11.6% vs. 70.4%, P<0.01). COX-2 expression was positively correlated to P-gp expression in relapsed B-NHL (r=0.998, P<0.01). The positive rates of COX-2 and P-gp were significantly higher in aggressive B-NHL than in indolent B-NHL (64.3% vs. 10.7%, P=0.002; 52.4% vs. 7.1%, P=0.012).

CONCLUSION

COX-2 and P-gp are highly expressed in relapsed B-NHL, and they may play a role in tumor metastasis of B-NHL.

Indigo carmine inhibits endothelium-dependent and -independent vasodilation

To investigate the potential mechanisms by which indigo carmine produces hypertension, we tested the hypothesis that indigo carmine inhibits endothelium-dependent vasodilation and determined the possible site of the inhibition (endothelium versus smooth muscle). Using isolated rat thoracic aortic rings that were precontracted with phenylephrine, we examined vasodilatory responses to acetylcholine, histamine, and Ca2+ ionophore A23187 (in endothelium-intact rings) and sodium nitroprusside and isoproterenol (in endothelium-denuded rings) in the presence and absence of indigo carmine. In addition, the effects of methylene blue on the acetylcholine- and sodium nitroprusside-induced vasodilation were compared with those of indigo carmine. Indigo carmine (10(-6), 10(-5), and 10(-4) mol/L) significantly inhibited receptor- and non-receptor-mediated endothelium-dependent vasorelaxation. Indigo carmine (10(-4) mol/L) also inhibited endothelium-independent vasorelaxation induced by sodium nitroprusside (an activator of vascular smooth muscle soluble guanylyl cyclase), although to a lesser extent than vasodilation from acetylcholine, histamine, and Ca2+ ionophore A23187. In contrast, indigo carmine (10(-4) mol/L) had no effect on the vasodilation induced by isoproterenol (an activator of adenylyl cyclase), indicating that indigo carmine selectively inhibits nitric oxide-mediated responses. Methylene blue, a known inhibitor of soluble guanylyl cyclase, inhibited both acetylcholine- and sodium nitroprusside-induced vasorelaxation. The inhibition was also greater in the acetylcholine- than the sodium nitroprusside-induced vasodilation. These results suggest that indigo carmine, like methylene blue, may inhibit endothelium-dependent relaxation by a mechanism that involves two levels. The major action of indigo carmine appears to be at the level of nitric oxide generation and/or release from the endothelial cell. In addition, indigo carmine appears to inhibit vascular smooth muscle guanylyl cyclase. Thus, indigo carmine may elevate blood pressure by interfering with these nitric oxide-mediated vasodilatory mechanisms.