[Research on the anti-tumor effects of CRYAB in prostate cancer].

OBJECTIVE: To explore the relationship between CRYAB and the prognosis of prostate cancer (PCa) as well as the potential mechanism. METHODS: Bioinformatics analysis was performed using R software, including differential gene expression and clinical correlation analysis, receiver operating characteristic (ROC) curve and Kaplan-Meier (KM) curve generation. Gene expression was detected using RT-qPCR, and protein expression was validated using Western Blot. The proliferation, apoptosis, and metastatic ability of PCa cells were detected using CCK8, TUNEL, Transwell migration, and invasion assays. RESULTS: According to the TCGA and GEO databases, CRYAB mRNA expression was down-regulated in PCa tissue compared with normal tissue (P< 0.05), and CRYAB mRNA and protein were down-regulated in PCa cells compared with RWPE1 cells (P< 0.05). Cell function experiments showed that up-regulated CRYAB could inhibit the proliferation, invasion, and migration of prostate cancer cells, promote apoptosis (P< 0.05), and up-regulate CDH1 expression while down-regulating CDH2 expression in the CRYAB-upregulated cell line. In addition, CRYAB mRNA expression was correlated with Gleason score (P< 0.01). The area under the ROC curve was 0.914, the KM curve showed that CRYAB had prognostic value for progression-free survival (P = 0.008) and disease-specific survival (P = 0.032). CONCLUSION: CRYAB is down-regulated in PCa tissue and is associated with the anti- tumor function of PCa cells. It may affect the metastatic ability of prostate cancer cells by regulating epithelial-mesenchymal transition molecules. CRYAB mRNA has important diagnostic and prognostic value in PCa.

A Functional Screening Identifies a New Organic Selenium Compound Targeting Cancer Stem Cells: Role of c-Myc Transcription Activity Inhibition in Liver Cancer.

Cancer stem cells (CSCs) are reported to play essential roles in chemoresistance and metastasis. Pathways regulating CSC self-renewal and proliferation, such as Hedgehog, Notch, Wnt/ß-catenin, TGF-ß, and Myc, may be potential therapeutic targets. Here, a functional screening from the focused library with 365 compounds is performed by a step-by-step strategy. Among these candidate molecules, phenyl-2-pyrimidinyl ketone 4-allyl-3-amino selenourea (CU27) is chosen for further identification because it proves to be the most effective compound over others on CSC inhibition. Through ingenuity pathway analysis, it is shown CU27 may inhibit CSC through a well-known stemness-related transcription factor c-Myc. Gene set enrichment analysis, dual-luciferase reporter assays, expression levels of typical c-Myc targets, molecular docking, surface plasmon resonance, immunoprecipitation, and chromatin immunoprecipitation are conducted. These results together suggest CU27 binds c-Myc bHLH/LZ domains, inhibits c-Myc-Max complex formation, and prevents its occupancy on target gene promoters. In mouse models, CU27 significantly sensitizes sorafenib-resistant tumor to sorafenib, reduces the primary tumor size, and inhibits CSC generation, showing a dramatic anti-metastasis potential. Taken together, CU27 exerts inhibitory effects on CSC and CSC-associated traits in hepatocellular carcinoma (HCC) via c-Myc transcription activity inhibition. CU27 may be a promising therapeutic to treat sorafenib-resistant HCC.

The splicing regulatory factor hnRNPU is a novel transcriptional target of c-Myc in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common liver cancer with high mortality. Here, we found that hnRNPU is overexpressed in HCC tissues and is correlated with the poor prognosis of HCC patients. Besides, hnRNPU is of high significance in regulating the proliferation, apoptosis, self-renewal, and tumorigenic potential of HCC cells. Mechanismly, c-Myc regulates hnRNPU expression at the transcriptional level, and meanwhile, hnRNPU stabilizes the mRNA of c-MYC. We found that the hnRNPU and c-Myc regulatory loop exerts a synergistic effect on the proliferation and self-renewal of HCC, and promotes the HCC progression. Taken together, hnRNPU functions as a novel transcriptional target of c-Myc and promotes HCC progression, which may become a promising target for the treatment of c-Myc-driven HCC.

A new protocol for long-term culture of a specific subpopulation of liver cancer stem cells enriched by cell surface markers.

Liver cancer stem cells (L-CSCs) are considered to be an important therapeutic target for hepatocellular carcinoma (HCC). This study provides a new in vitro long-term culture model for a specific subpopulation of L-CSCs enriched by cell surface markers. We combined CD13, CD133 and EpCAM to selectively enrich L-CSCs, which we then cultured in modified chemically defined medium. The enriched L-CSCs exhibited enhanced proliferation, self-renewal and long-term clonal maintenance ability as compared with non-CSCs. Compared with wild-type hepatocellular carcinoma, the expression of stemness surface markers, oncogenes, drug resistance and tumorigenicity in enriched L-CSCs was significantly increased. In summary, the subpopulation of L-CSCs still maintains cancer stem cell-related phenotypes after 14 days of culture.

Arsenic trioxide inhibits liver cancer stem cells and metastasis by targeting SRF/MCM7 complex.

Hepatocellular carcinoma (HCC) has a high mortality rate due to the lack of effective treatments and drugs. Arsenic trioxide (ATO), which has been proved to successfully treat acute promyelocytic leukemia (APL), was recently reported to show therapeutic potential in solid tumors including HCC. However, its anticancer mechanisms in HCC still need further investigation. In this study, we demonstrated that ATO inhibits tumorigenesis and distant metastasis in mouse models, corresponding with a prolonged mice survival time. Also, ATO was found to significantly decrease the cancer stem cell (CSC)-associated traits. Minichromosome maintenance protein (MCM) 7 was further identified to be a potential target suppressed dramatically by ATO, of which protein expression is increased in patients and significantly correlated with tumor size, cellular differentiation, portal venous emboli, and poor patient survival. Moreover, MCM7 knockdown recapitulates the effects of ATO on CSCs and metastasis, while ectopic expression of MCM7 abolishes them. Mechanistically, our results suggested that ATO suppresses MCM7 transcription by targeting serum response factor (SRF)/MCM7 complex, which functions as an important transcriptional regulator modulating MCM7 expression. Taken together, our findings highlight the importance of ATO in the treatment of solid tumors. The identification of SRF/MCM7 complex as a target of ATO provides new insights into ATO's mechanism, which may benefit the appropriate use of this agent in the treatment of HCC.

MicroRNA-29a-3p Downregulation Causes Gab1 Upregulation to Promote Glioma Cell Proliferation.

BACKGROUND/AIMS: Glioma causes significant human mortalities annually. Molecularly-targeted therapy is a focus of glioma research. METHODS: Grb2-associated binding 1 (Gab1) expression and microRNA-29a-3p ("miR-29a-3p") expression in human glioma cells and tissues were tested by Western blotting assay and qRT-PCR assay. shRNA/siRNA strategy was applied to silence Gab1 in human glioma cells. miR-29a or anti-sense miR-29a construct was transfected to human glioma cells. Cell proliferation was tested by BrdU ELISA assay and cell counting assay. RESULTS: We show that expression of Gab1 was significantly elevated in human glioma tissues and cells, which correlated with downregulation of its putative microRNA: miR-29a-3p. In A172 glioma cells and primary human glioma cells, Gab1 shRNA/siRNA inhibited Akt-Erk activation and cell proliferation. Forced-expression of miR-29a-3p downregulated Gab1, inhibiting glioma cell proliferation, whereas miR-29a-3p was in-effective on cell proliferation in Gab1-silenced A172 cells. Furthermore, introduction of a 3'-untranslated region (3'-UTR) mutant Gab1 (UTR-G160A) blocked miR-29a-3p-induced inhibition on Akt signaling and A172 cell proliferation. CONCLUSIONS: miR-29a-3p downregulation leads to Gab1 upregulation to promote glioma cell proliferation.

Solidification/stabilization of dredged marine sediments for road construction.

Cement/lime-based solidification is an environmentally sound solution for the management of dredged marine sediments, instead of traditional solutions such as immersion. Based on the mineralogical composition and physical characteristics of Dunkirk sediments, the effects of cement and lime are assessed through Atterberg limits, modified Proctor compaction, unconfined compressive strength and indirect tensile strength tests. The variation of Atterberg limits and the improvement in strength are discussed at different binder contents. The potential of sediments solidified with cement or lime for road construction is evaluated through a proposed methodology from two aspects: I-CBR value and material classification. The test results show the feasibility of solidified dredged sediments for beneficial use as a material in road construction. Cement is superior to lime in terms of strength improvement, and adding 6% cement is an economic and reasonable method to stabilize fine sediments.

[The impact of autologous stem cell transplantation on the prognosis in multiple myeloma].

OBJECTIVE: To evaluate the efficacy of autologous stem cell transplantation (ASCT) in the treatment of multiple myeloma (MM) and its impact on the prognosis of MM. METHODS: Retrospective analysis was performed in 28 patients with MM (group A) treated with ASCT in our hospital from October 1998 to February 2007, compared with those not received ASCT in the same time period including 23 patients with near complete response (nCR) or better (group B) and 25 patients with partial response (PR) (group C). The duration of response (DOR), time to progression (TTP) and overall survival (OS) were compared by Kaplan-Meier method in the 3 groups. RESULTS: Eight patients without nCR or better (7 in PR and 1 in MR) after ASCT achieved CR (2 cases) and nCR (5 cases). Complete response (CR) rate was 10.7% (3 cases) and 42.9% (12 cases) before and after ASCT respectively in group A. DOR was 33 months for group A, 17 months for group B and 18 months for group C, and TTP was 45, 43 and 28 months respectively. After a median follow-up of 30 months, patients in group A and in group B had a trenel of longer OS than in group C although there was no statistically significant difference. CONCLUSIONS: ASCT can further enhance the response, prolong the DOR and TTP and probably OS, and therefore improve the quality of life in MM. MM patients not achieved good response by non-ASCT therapy may benefit from ASCT.

[Study on the relationship of beta-catenin level and sensitivity to Bortezomib of myeloma cell lines].

OBJECTIVE: To explore the relationship of beta-catenin and sensitivity to Bortezomib of myeloma cell lines. METHODS: Myeloma cell lines RPMI8226, CZ-1 and NCI-H929 were treated with Bortezomib and 2ME2, alone or in combination. Typan blue dye exclusion and modified MTT were used to assess the cell viability with or without treatment. Annexin V-FITC and PI staining was performed to detect apoptosis rate. RT-PCR was used to detect beta-catenin mRNA and western blot to analyze beta-catenin protein. RESULTS: The basic expression level of beta-catenin was different in tested myeloma cell lines: RPMI8226 was the most while NCI-H929 the least and CZ-1 the intermediate. IC50 of RPMI8226, CZ-1 and NCI-H929 were (49.8 +/- 0.6), (24.7 +/- 0.4) and (8.4 +/- 0.2) nmol/L, respectively. After the treatment of Bortezomib (at 0, 1, 5, 10 nmol/L), beta-catenin level of tested cell lines accumulated in a time and dose dependent manner for western blot, while no significant change was observed in the result of RT-PCR. The beta-catenin protein levels in the Bortezomib (5 nmol/L) and 2ME2 (1 micromol/L) treated cell group were much lower than that in Bortezomib (5 nmol/L) group, the decrease of the gray scale of beta-catenin/beta-actin was 64.03% for RPMI8226, 52.56% for CZ-1, 51.48% for NCI-H929, and the apoptosis rates were 8.00, 1.86 and 1.19 times increase compared to untreated group. CONCLUSION: Myeloma cell lines with higher beta-catenin level are less sensitive to Bortezomib, and combination treatment of low dose 2ME2 and Bortezomib can reduce beta-catenin accumulation and enhance the sensitivity to Bortezomib.

[Detection of serum free light chain and its clinical significance in nonsecretory multiple myeloma].

OBJECTIVE: To explore the clinical significance of serum free light chain (sFLC) levels in nonsecretory multiple myeloma (NSMM). METHODS: Nine NSMM patients were hospitalized in our department from Feb 2002 to Sep 2006 and no M-components was found in their serum and urine by immunofixation electrophoresis (IFE). sFLC was assayed by immuno-nephelometry. The clonality of sFLC was estimated by serum kappa:lambda sFLC ratio. Meanwhile, serum immunoglobulin, total kappa and lambda light chain level were also determined in these patients. RESULTS: Increased serum concentrations of either kappa or lambda sFLC (and abnormal kappa/lambda ratios) were detected in 6 of 9 patients with NSMM although their serum immunoglobulin levels were not elevated and total kappa:lambda light chain ratios (1.32 - 2.20) were in the reference range. All the 9 patients had clonal IgH gene rearrangements. CONCLUSION: Quantification of sFLC by immuno-nephelometry is more sensitive than that of serum total light chain measurement and is helpful in estimating the clonality of the light chain in patients with NSMM.

[Bortezomib-based combination therapy for relapsed or refractory multiple myeloma].

OBJECTIVES: To investigate the efficacy and toxicity of bortezomib based combination therapy for Chinese patients with relapsed or refractory multiple myeloma (MM), and to determine the combination regimen, dosage and cycles in application of bortezomib for MM therapy. METHODS: Forty-six patients with refractory or relapsed myeloma were treated with bortezomib (1.3 mg/m2) as an intravenous bolus twice weekly for 2 weeks on day 1, 4, 8, and 11 in a 3-4 week cycle, in combination with dexamethasone, dexamethasone plus thalidomide, CD (C-cytoxan, D-dexamethasone), MD (M-mitoxsnteone), DCEP (E-etoposide, P-platinol), and DT-PACE regimens (T-thalidomide, A-adriamycin). Response to bortezomib was evaluated according to the criteria of the International Myeloma Working Group (IMWG) before initiation of each cycle. Adverse events were graded according to the National Cancer Institute Common Toxicity Criteria, version 3.0. Forty-nine matched patients with relapsed and refractory MM who received thalidomide based combination therapy were used as a historical control group. RESULTS: Among 43 of the 46 patients whom could be evaluated, the overall response rate was 72.1% (the control group was 51.0%, P < 0. 05), including complete response in 5 patients (11.6%), very good partial response in 12 patients (27.9%), and partial response in 14 patients (32.6%). The overall response rate after one and two cycles was 30.2% and 58.1% (P < 0.05), respectively. The frequent adverse events were thrombocytopenia (62.8%), fatigue (55.8%), nausea (51.2%) and peripheral neuropathy (30.2%); all of the events could be tolerated. The most common adverse event in the control group was constipation( 69.4%), followed by fatigue (59.2%) and dizziness (46.9%). CONCLUSIONS: Bortezomib based combination therapy is a new effective therapy in relapsed or refractory myeloma patients with a higher response rate and different toxicities as compared with thalidomide based combinations.

[Effect of arsenic trioxide combined with bortezomib on proliferation, apoptosis and beta-catenin level in myeloma cell lines].

The aim of this study was to investigate the effect of arsenic trioxide (As(2)O(3)) combined with bortezomib on the proliferation, apoptosis and beta-catenin level in myeloma cell lines. Myeloma cell lines RPMI8226, CZ-1 and NCI-H929 were treated with As(2)O(3) and bortezomib alone or in combination for 48 hours. Trypan blue dye exclusion and modified MTT were used to assess the cell viability. Flow cytometry with Annexin V-FITC and PI staining was used to detect the apoptosis rate. The beta-catenin level was analyzed by Western blot. The results showed that IC(50) of bortezomib to RPMI8226, CZ-1 and NCI-H929 were 46.9, 20.7 and 6.8 nmol/L, respectively. After the combination treatment with bortezomib (5 nmol/L) and As(2)O(3) (1 micromol/L), the cell viability of RPMI8226, CZ-1 and NCI-H929 decreased from 88.99%, 72.23%, 51.06% to 54.01%, 39.59%, 25.00%(p<0.05), the apoptosis rate increased from 11.1+/-0.1%, 26.8+/-1.7%, 46.8+/-5.5% to 36.1+/-2.2%, 60.4+/-3.8%, 76+/-5.6% (p<0.01) respectively. The Q value of two groups lies between enhancement and significant enhancement (1.198 - 3.75). Besides, beta-catenin levels in tested cell lines were decreased to 24.15%, 31.85%, 33.72% of their basic constitutions respectively (p<0.05). It is concluded that combination treatment of As(2)O(3) and bortezomib can enhance the proliferation inhibition and apoptosis induction of bortezomib to myeloma cell lines, reduce beta-catenin level, and increase the sensitivity of myeloma cell lines to bortezomib.

[Efficacy of thalidomide combined dexamethasone on newly diagnosed multiple myeloma].

BACKGROUND & OBJECTIVE: Thalidomide is effective in treating refractory and relapsed multiple myeloma (MM). However, the efficacy of thalidomide in induction therapy for newly diagnosed MM remains unknown. This study was to evaluate the efficacy of thalidomide combined dexamethasone (TD induction regimen) on previously untreated MM, and observe the adverse events. METHODS: Thirty-nine patients with newly diagnosed MM received oral administration of thalidomide at a dose of 100-300 mg/day continuously and dexamethasone at a dose of 20-40 mg/day on Days 1-4, 9-12, 17-20 in odd months and on Days 1-4 in even months. TD regimen was repeated every 28 days. Thirty-six MM patients who received VAD regimen (vindesine, adriamycin, and dexamethasone) was regarded as a historical matched controls. The efficacy, survival time and adverse events were compared between the two groups. RESULTS: The overall response rates were 71.8% in TD group and 61.1% in VAD group (P>0.05). The median progression-free survival was 14 months in TD group and 9 months in VAD group (P>0.05). Within a median follow-up of 13 months (range, 1-30 months), median overall survival (OS) was not reached in TD group, and was 29 months in VAD group. The most common adverse events (always not higher than grade 2) were constipation, fatigue, dizziness and somnolence in TD group. More grade 3-4 adverse events, included leucopenia and thrombocytopenia, and higher infection rate were observed in VAD group as compared with those in TD group (P<0.05). CONCLUSIONS: The combination of thalidomide and dexamethasone is an effective induction regimen for newly diagnosed MM. It may be considered as a replacement of VAD regimen.

Prognostic factors and staging systems of multiple myeloma:.

BACKGROUND: Previous studies found a range of prognostic factors but no consensus about the proper staging system for multiple myeloma has been achieved. This study explored the prognostic factors to find a staging system for multiple myeloma most suitable for Chinese patients. METHODS: Between February 1990 to August 2004, 206 patients (138 men and 68 women, mean aged (59 +/- 11) years) who were initially diagnosed as multiple myeloma in Changzheng Hospital (Shanghai, China) and had followup records were enrolled in this study. Potential prognostic factors were evaluated by univariate and multivariate analyses. Four staging systems were applied to compare their suitability for the patients. RESULTS: The median survival time of the patients was 33 months. The 1-, 3- and 5-year survival rates were 80.18%, 48.08% and 33.7% respectively. Factors identified as adversely affecting survival were older age, severe bone lesions, low haemoglobin, low platelet, low serum calcium, low serum albumin, high proportion of plasma cells in marrow, high serum creatinine, high serum beta(2) microglobulin and high C-reactive protein. Among these, only C-reactive protein, beta(2) microglobulin, albumin and age were the independent prognostic factors. There were statistically significant survival differences among the three groups in Durie Salmon staging system and Bataille staging system, but not in British Medical Research Council staging system or International Staging System. CONCLUSIONS: High beta(2) microglobulin, high C-reactive protein, low albumin and old age are independent prognostic factors of multiple myeloma. Bataille staging system appears to be optimal for Chinese multiple myeloma patients.

[Clinical features of multiple myeloma patients with extramedullary disease: a report of 40 cases from a single center].

OBJECTIVE: To analyze the clinical and laboratory features and risk factors of multiple myeloma (MM) with extramedullary disease (EM) and its extraosseous localizations at diagnosis and during the course of MM. METHODS: The clinical features, survival rate and prognostic factors were retrospectively analyzed in 40 patients having EM from a total of 418 MM patients hospitalized in Changzheng Hospital from 1993 to 2006. RESULTS: Among the 40 patients, the first three localizations of EM involved soft tissue, pleura or peritoneum and central nervous system (CNS). Median duration of follow-up was 30 months. The median overall survival (OS) was 28 months. Twenty-five patients (6%) were found to have EM at diagnosis (group A), and their median OS was 16 months and 15 patients (3.6%) developed EM during the course of the disease (group B), and their expected median OS was 72 months. There was a significant difference between group A and B (P = 0.0045) for OS. Compared with those in group A, patients in group B had a higher percentage of plasmacytes (P = 0.022) and plasmablasts (P = 0.029) in bone marrow, and less advanced stage for international staging system (ISS) (P = 0.027). Log-rank univariate analysis showed that higher CRP level, higher serum LDH, Stage II and III for ISS, Hb < 110 g/L at diagnosis were poor prognostic factors. However, multivariate analysis with COX model showed none of them were statistically significant. CONCLUSION: EM tumors are not a rare manifestation of MM. Soft tissue in the commonest area involved. Higher serum CRP and LDH level, more advanced stage for ISS, anemia and having EM are poor prognostic factors of MM.

[Prognostic analysis and assessment on the clinical staging systems of multiple myeloma--a report of 206 cases].

BACKGROUND & OBJECTIVE: Multiple myeloma (MM) is a heterogeneous disease of plasma cell tumor with poor prognosis. This study was to explore the prognostic factors of MM in China, and find the most suitable clinical staging systems. METHODS: Univariate and multivariate analyses were carried out on 18 clinical and laboratory indexes from 206 MM patients. These MM patients were classified according to 4 staging systems to compare their survival status. RESULTS: Of the 206 patients, 138 were men and 68 were women, with median age of 59 years (ranged 27-90 years) and median survival time of 33 months. The 2-and 5-year survival rates were 64.7% and 33.7%. Univariate analysis identified 10 prognostic factors: age, the amount of bone marrow plasma cells, hemoglobin, platelet count, adjusted serum calcium, albumin, creatinine, beta2 microglobulin, C-reactive protein, and skeletal disease stage. Multivariate analysis showed that C-reactive protein, beta2 microglobulin, albumin, age were independent prognostic factors. Significant differences of survival period existed among the 3 groups classified according to Durie Salmon staging system and Bataille staging system as well as between group I and group II of International staging system. However, no significant difference was found among the 3 groups classified according to British Medical Research Council staging system and between group II and group III of International staging system. CONCLUSIONS: High level of C-reactive protein, high level of beta2 microglobulin, low level of albumin and old age are correlated to poor prognosis. Durie Salmon staging system and Bataille staging system are suitable for Chinese MM patients.

[The effect of cyclin D2 shRNA on the proliferation and apoptosis of LP-1 cell].

OBJECTIVE: To construct cyclin D2 (CCND2) short hairpin RNA ( shRNA) plasmid for repressing the expression of CCND2 in human myeloma cell line LP-1,and to detect its effect on the proliferation and apoptosis of LP-1 cell. METHODS: A CCND2 shRNA model was constructed and cloned into plasmid pGensil-2, then the plasmid was transfected into LP-1 cell in vitro. The CCND2 expression cell proliferation, cell cycle and cell apoptosis of the transfected LP-1 cells were studied by RT-PCR, trypanosome staining, flow cytometry and annexin V assay. RESULTS: The transfection efficiency of LP-1 cell was 34. 2%. In the transfected LP-1 cell CCND2 mRNA expression was reduced significantly, the cell growth was inhibited significantly and the cell cycle was partly arrested in G, phase. The apoptosis rate of the transfected LP-1 cell after 72 h was (25.7+/-4.8)%. CONCLUSION: The inhibition of CCND2 in LP-1 cells could inhibit the cell growth and induce cell apoptosis. CCND2 maybe a new therapeutic target.

[Mechanism of arsenic trioxide-induced cytotoxicity on multiple myeloma cells].

BACKGROUND & OBJECTIVE: Multiple myeloma (MM), a plasma cell tumor, is difficult to cure by now. Previous study showed that As2O3 could inhibit the proliferation and induce the apoptosis of myeloma cell in vitro. The aim of this study was to explore the possible mechanism of arsenic trioxide (As2O3) on multiple myeloma cells. METHODS: The cytotoxic effects of As2O3 on five myeloma cell lines U266, SKO-007, LP-1, HS-Sultan, and KM3 were examined using MTT bioassay, and the concentration of 50% growth inhibition (IC(50)) was calculated. The synergistic or antagonistic effects of menadione (VK(3)), N-acetyl-cysteine (NAC), and reduced glutathione (GSH) combined with As2O3 were also examined. The cellular GSH levels in five MM cell lines and its changes in U266 cells after treated with As2O3, VK(3), NAC, and exogenous GSH were determined by colorimetric assay, and the relationship between IC(50) and cellular GSH levels was analyzed. RESULTS: As2O3 inhibited the proliferation of all five myeloma cells, but with different sensitivity. GSH contents in five MM cells were correlated with its IC(50) significantly (r=0.87,P< 0.05). Oxidant VK(3) had significant synergistic effect with As2O3, and antioxidants NAC and GSH partly blocked the growth inhibition of As2O3. Both As2O3 and VK(3) decreased the GSH contents, NAC and GSH increased them contrarily. CONCLUSION: One of the mechanisms of effect of As2O3 on myeloma cells may be through decreasing the cellular GSH levels and inducing myeloma cell apoptosis.

[Real-time quantitative PCR detecting minimal residual disease in multiple myeloma patients after autologous peripheral blood stem cell transplantation].

In order to explore the role of real-time PCR in detecting minimal residual disease in multiple myeloma and Waldenstrom's macroglobulinemia after autologous peripheral blood stem cell transplantation (APBSCT), real-time PCR was used to quantitate the IgH rearrangement in 8 patients with multiple myeloma (MM) and 1 case of Waldenstrom's macroglobulinemia before and after APBSCT. The results showed that the copies of IgH rearrangement pre- or post-APBSCT were 3108 +/- 1043 and 549 +/- 660 (P < 0.05) respectively. The number of IgH copies was positively correlated with the amount of plasmocytes in patient 's bone marrow and the M-protein in peripheral blood (r = 0.86, P < 0.05). Similar result was obtained in a case of relapsed Waldenstrom's macroglobulinemia. In conclusion, the quantitative analysis of IgH rearrangement by real-time PCR is a novel way to evaluate the therapeutic efficaciousness and predict the prognoses in MM patients.

[Effects of arsenic trioxide on cell cycle and expression of cyclin dependent kinase inhibitors of multiple myeloma cells].

OBJECTIVE: To study the effects of arsenic trioxide (As(2)O(3)) on cell cycle and expression of cyclin dependent kinase inhibitors (CDKIs) in multiple myeloma (MM) cells, and explore its pharmacological mechanism. METHODS: The DNA content of MM cells line HS-Sultan was analyzed by flow cytometry after exposure to As(2)O(3), the effects on expression of CDKI P15, P16 AND P21 were studied by reverse transcriptase PCR. RESULTS: DNA flow cytometric analysis showed that As(2)O(3) induced most of HS-Sultan cells, arrest at G(0)/G(1) phase and a small fraction at G(2)/M phase and apoptosis occurred mainly in S phase. There was no expression of P15 and P16 mRNA in untreated HS-Sultan cells and 1.0 micromol/L As(2)O(3) could make them expressed after exposed 24 or 48 hours respectively. Expression of P12 mRNA was obviously elevated by As(2)O(3) comparing with that of control. CONCLUSION: One of the pharmacological mechanisms of As(2)O(3) is to activate the expression of CDKI P15, P16 and P21, and consequently affect cell proliferation cycle.