Inhibition of topoisomerase II by antitumor agents bis(2,6-dioxopiperazine) derivatives.

Several recently developed derivatives of bis(2,6-dioxopiperazine) have been shown to be new antitumor agents and are currently under clinical trials. We found that the mother compound of the bis(2,6-dioxopiperazine)s, ICRF-154, and its derivatives, ICRF-159, ICRF-193, and MST-16, are all inhibitors of mammalian type II DNA topoisomerase. By decatenation assay using kinetoplast DNA from Crithidia fasciculata, inhibition of purified calf thymus topoisomerase II by these compounds was investigated. Potency of inhibition was in the following order: ICRF-193 greater than ICRF-154 = ICRF-159 greater than MST-16. The doses giving 50% inhibition were 2, 13, 30 and 300 microM, respectively, for these compounds. ICRF-193, the most potent inhibitor, however, did not inhibit topoisomerase I at concentrations up to 300 microM. Addition of excess enzyme, but not of the substrate DNA, overcame the inhibition by ICRF-193. The drug did not stimulate the formation of cleavable complex between DNA and the enzyme. Furthermore, ICRF-193 even inhibited the formation of enzyme-mediated DNA cleavage induced by etoposide or 4'-[9-acridinylamino)methanesulfon-m-anisidide. These observations, together with the finding that ICRF-193 did not intercalate into DNA, suggest that ICRF-154 and related compounds are specific inhibitors of topoisomerase II with different modes of action: i.e., they interfere with some step(s) before the formation of the intermediate cleavable complex in the catalytic cycle. This is a property quite distinct from previously known cleavable complex-forming type topoisomerase II-targeting antitumor agents such as acridines, anthracyclines, and epipodophyllotoxins, but rather, mechanistically similar to the recently reported group of inhibitors that includes merbarone, aclarubicin, and fostriecin.     

Inhibition of intracellular topoisomerase II by antitumor bis(2,6-dioxopiperazine) derivatives: mode of cell growth inhibition distinct from that of cleavable complex-forming type inhibitors.

In the accompanying paper (K. Tanabe, Y. Ikegami, R. Ishida, and T. Andoh, Cancer Res., 51: 4903-4908, 1991), we showed that ICRF-154 and -193, dioxopiperazine derivatives, inhibited the activity of purified topoisomerase II, without formation of a cleavable DNA-protein complex. In order to see whether ICRF-154 and ICRF-193 affect cellular topoisomerase II in situ or not, we examined the effect of these drugs on etoposide (VP-16)-induced, topoisomerase II-mediated DNA breaks in RPMI 8402 cells by alkaline sedimentation analysis. When RPMI 8402 cells were exposed to VP-16 in the presence of ICRF-154 or ICRF-193 for 1 h, VP-16-induced DNA strand breaks were greatly inhibited by both ICRF compounds. In parallel with this observation, VP-16-induced growth inhibition was also reversed by ICRF-193. Exposure of cells to ICRF-154 resulted in a progressive accumulation of cells with 4C DNA content. Although mitotic index did not significantly increase, mitotic abnormalities were seen in cells exposed to ICRF-193 or ICRF-154: all mitotic cells exhibited early mitotic figures with fewer condensed and entangled chromosomes. The most sensitive phase of the cell cycle to ICRF-154 was the G2-M. ICRF-154 did not affect the spindle formation. However, abnormally oriented spindles were observed in drug-treated cells in parallel with the appearance of multinucleated cells. The results suggest that ICRF-154 and -193 inhibit topoisomerase II activity in RPMI 8402 cells, and this effect resulted in the appearance of cells in G2 and early M phase with fewer condensed and entangled chromosomes and of cells with multilobed nuclei.     

Antitumor activities and schedule dependence of orally administered MST-16, a novel derivative of bis(2,6-dioxopiperazine)

Summary We studied bioavailability, treatment schedule dependence, and therapeutic efficacy of orally administered MST-16, a novel derivative of bis(2,6-dioxopiperazine), against murine tumors and human tumor xenografts. The rate of its intestinal absorption was about 50%, and it was immediately metabolized to its parent compound, ICRF-154. Therapeutic efficacy of MST-16 was heavily dependent on the treatment schedule: 9 daily oral administrations and treatment every 4 h on day 1 only were much more effective against s.c.-implanted L1210 leukemia than a single dose or five daily administrations giving the same total dose. Orally administered MST-16 showed potent lifeprolonging effects (196%, 219% and 148%) in mice inoculated i.p. with P388, L1210 leukemia, and C-26 colon adenocarcinoma, respectively, but had no effect on B16 melanoma inoculated in the same way. MST-16 inhibited more than 80% growth of Lewis lung carcinoma, B16 melanoma, and C-38 colon adenocarcinoma implanted s.c., but had only a minor effect on M5076 fibrosarcoma. Lung metastasis of Lewis lung carcinoma was also effectively suppressed. Furthermore, MST-16 significantly inhibited growth of human colon, lung and breast cancers implanted s.c. in nude mice. We also made a kinetic analysis of the in vitro cell-killing effect by ICRF-154, the active form of MST-16 in vivo. It demonstrated a cell cycle phase-specific and time-dependent action, providing a reasonable explanation for the schedule-dependent therapeutic effect of MST-16.     

MST-16, a novel derivative of bis(2,6-dioxopiperazine), synergistically enhances the antitumor effects of anthracyclines

MST-16, a derivative of bis(2,6-dioxopiperazine), is a newly developed anticancer agent that is potentially effective in combination with anthracyclines. It has a structural similarity to ICRF-187. The effects of MST-16 and its active form, ICRF-154, on the cytotoxic activities of six anthracyclines were investigated both in␣vitro and in vivo. Adriamycin (ADM), therarubicin (THP) and ME2303 (ME) showed synergistic cytotoxicity against colon 26 cells, when combined with MST-16. Epirubicin (EPI) and menogaril (TUT-7) and daunomycin (DM) all had a combination index of less than 1.0 only in the lower fraction affected range and, so there were probably no synergistic interactions between these drugs and MST-16. In colon 26 tumor-bearing mice, a significant delay in tumor growth was noted in the mice treated with ADM (7.5 mg/kg) and MST-16 (750 mg/kg) compared with mice given either drug alone. Similarly, tumor growth in mice treated with THP (10 mg/kg) or ME (10 mg/kg) with MST-16 (750 mg/kg) was significantly delayed. To elucidate the mechanism of synergy between these anthracyclines and MST-16, the concentration of anthracyclines in the treated cells was measured by flow cytometry. No increased intracellular accumulation of ADM, THP or ME was evident even when combined with MST-16. Cell cycle analysis revealed that MST-16 enhanced the accumulation of cells in G₂M induced by ADM, THP and ME 1.6, 1.4, and 1.5 times, respectively. We thus conclude that the administration of ADM, THP and ME combined with MST-16 is synergistic and that the mechanism may not include an increase in the intracellular drug uptake but rather an increase in G₂M accumulation. Received: 27 December 1996 / Accepted: 1 December 1997     

Antitumor activity of MST-16, a novel derivative of bis(2,6-dioxopiperazine), in murine tumor models

Summary We studied the antitumor activity of newly synthesized bis(1-acyloxymethyl) derivatives of 4,4′-(1,2-ethanediyl)bis(2,6-piperazinedione) using i.p.-i.p. models of P388 leukemia and B16 melanoma. As a result, we found 4,4′-(1,2-ethanediyl)bis(1-isobutoxycarbonyloxymethyl-2,6-piperazinedione) (MST-16) to possess considerable therapeutic activity. MST-16 showed not only marked life-prolonging effects in both P388 leukemia- and B16 melanoma-bearing mice but also a greater therapeutic ratio than did its parent compounds, ICRF-154 and ICRF-159. Further studies revealed that MST-16 has considerable therapeutic activity against a number of other tumors such as ascitic forms of L1210 leukemia, colon 26 adenocarcinoma, and MH-134 hepatoma and solid forms of B16 melanoma, Lewis lung carcinoma, colon 38 adenocarcinoma, and M5076 fibrosarcoma. These results suggest that MST-16 is very promising as an antitumor agent.     

Phase II study: treatment of non-Hodgkin's lymphoma with an oral antitumor derivative of bis(2,6-dioxopiperazine).

BACKGROUND: Although razoxane (ICRF-159), a derivative of bis(2,6-dioxopiperazine), has shown significant antitumor activity in several murine tumors, inadequate bioavailability has limited its clinical efficacy. Sobuzoxane (MST-16), another derivative of bis(2,6-dioxopiperazine), has shown activity against a broad spectrum of murine tumors and human tumor xenografts in nude mice and a lack of cross-resistance to vincristine, doxorubicin, cyclophosphamide, fluorouracil, etoposide, and mitomycin C. These findings suggest that MST-16 has a mode of cytocidal activity different from that of other antitumor agents. PURPOSE: The present late phase II study was conducted to evaluate the clinical efficacy and toxicity of MST-16 in non-Hodgkin's lymphoma (NHL). METHODS: As part of a multi-institutional cooperative study, we conducted a study of MST-16 in 27 patients with NHL who were assessable for drug efficacy and toxicity. MST-16, a bis(2,6-dioxopiperazine) analogue and an inhibitor of topoisomerase II, was administered orally at a dose of 1600 mg/m2 a day for 5-7 days at intervals of 2-3 weeks. RESULTS: Response consisted of one complete remission and seven partial remissions in 27 assessable patients. Response was achieved at a median of 13 days (range, 9-62 days) after initiation of therapy and lasted a median of 46 days (range, 29-155 days). Major toxic effects were leukopenia in 70% of the patients, thrombocytopenia in 44%, and gastrointestinal disorders in 37%. CONCLUSIONS: MST-16 was shown to be effective in NHL and deserves further clinical trial, since the drug shows little cross-resistance to available antitumor drugs. IMPLICATIONS: Phase II clinical studies of MST-16 in treatment of breast cancer, gastric cancer, and adult T-cell leukemia and lymphoma are also being conducted in Japan. Future trials of combination chemotherapy using MST-16 with other antitumor drugs are warranted in view of the additive effects observed in studies of MOLT-3 cells and studies of L1210 leukemia in mice.     

miR-149通过靶向FOXM1基因抑制前列腺癌细胞的生长和侵袭

  目的  探讨miR-149对前列腺癌细胞生长和侵袭的影响,并研究miR-149的靶基因及其功能。  方法  利用实时荧光定量PCR检测前列腺癌和癌旁组织miR-149和FOXM1 mRNA表达水平。在人前列腺癌细胞系PC3和DU145细胞中瞬时转染miR-149模拟物和阴性对照miRNA,运用平板克隆形成和Transwell侵袭实验检测细胞生长和侵袭。在细胞中分别转染miR-149靶基因FOXM1的siRNA和siRNA阴性对照,利用Western blot检测FOXM1蛋白表达情况,并检测细胞的克隆形成和侵袭能力。  结果  在前列腺癌中miR-149低表达（P < 0.01）,FOXM1 mRNA高表达（P < 0.01）。与对照组细胞相比,转染miR-149模拟物的PC3和DU145细胞克隆数目减少（P < 0.01）,发生侵袭的细胞减少（P < 0.01）;FOXM1蛋白水平在转染miR-149模拟物的PC3（P < 0.01）和DU145细胞（P < 0.05）中较对照组细胞降低。转染FOXM1 siRNA的PC3和DU145细胞中FOXM1蛋白水平较对照组降低,且克隆形成和侵袭能力较对照组明显降低（P < 0.01）。  结论  miR-149通过靶向FOXM1抑制前列腺癌细胞生长和侵袭,发挥着抑癌基因的作用,可作为前列腺癌分子治疗的有效靶点。      

Potentiation and inhibition of tumor cell invasion by host cells and mediators

A culture model for invasion of rat mesothelial cell layer by rat ascites hepatoma cells has been developed. By using this quantitative model, the preculture with macrophages (0.1 less than macrophage/tumor cell less than 1.0) was found to enhance both the in vitro and in vivo invasive potentials of the tumor cells. This potentiation appears to be mediated partly by oxygen radicals generated by the cocultured macrophages. The in vitro invasive capacity was also augmented by pretreating the tumor cells with TGF-beta or with activated platelets. A factor with anti-invasive potential (IIF) was extracted from rat liver. It inhibited the directed migration but not the growth of the tumor cells and was effective on their in vivo invasion and metastasis, as well.     

Taxol blocks processes essential for prostate tumor cell (PC-3 ML) invasion and metastases.

We have examined the antimetastatic effects of taxol on a PC-3 human prostatic tumor variant (PC-3 ML) which metastasizes to the lumbar vertebrae in severe combined immunodeficiency-carrying (SCID) mice. Immunofluorescence labeling indicated that taxol (0.5 to 1.0 microM for 6 h) produced an abnormal bundling of microtubules in a dosage-dependent manner. Slot blotting and gelatinase assays revealed that taxol inhibited secretion of the M(r) 72,000 and M(r) 92,000 type IV collagenases plus a M(r) 57,000 gelatinase. Radioimmunoprecipitation measurements confirmed that the drug inhibited both the secretion and the synthesis of the M(r) 72,000 collagenase. Taxol also blocked total protein secretion but did not influence total protein synthesis or turnover. Boyden chamber chemotactic studies further showed that taxol (0.5 to 1.0 microM) inhibited invasion of Matrigel. More importantly, studies in SCID mice demonstrated that taxol (50 to 250 mg/m2/day) blocked the establishment, growth, and long-term survival of PC-3 ML cells.     

Human chorionic gonadotropin beta (HCGbeta) down-regulates E-cadherin and promotes human prostate carcinoma cell migration and invasion

BACKGROUND: Membrane-associated human chorionic gonadotropin beta (HCGbeta) is correlated with a poor prognosis in localized prostate adenocarcinoma. The relationship between HCGbeta and metastasis, however, is unclear. METHODS: To shed some light on the issue, two stable prostate carcinoma cell lines overexpressing HCGbeta, designated DU145 HCGbeta and PC3 HCGbeta, were created and compared with empty vector stably transfected DU145 and PC3 cells (control cells). RESULTS: HCGbeta expression resulted in a change in morphology; the cells were more elongated and had multiple pseudopodia, while the control cells were more rounded. This change in morphology was duplicated by incubating control cells in conditioned medium from the DU145 HCGbeta or PC3 HCGbeta cells, or by adding purified HCGbeta to control medium. The DU145 HCGbeta and PC3 HCGbeta cells were also less adherent than the controls, as assessed by the ease with which trypsin-EDTA could remove them from culture plates. Reduced adherence could be duplicated by incubation of control cells with either conditioned medium or purified HCGbeta. Western blot analysis showed that DU145 HCGbeta and PC3 HCGbeta cells expressed less E-cadherin than control cells and that a change of medium increased expression of E-cadherin. Addition of conditioned medium, or purified HCGbeta, to control cells down-regulated E-cadherin. Cell migration and invasion assays showed that DU145 HCGbeta and PC3 HCGbeta cells were more migratory and invasive than controls and that treatment of control cells with either conditioned medium or purified HCGbeta increased their migratory/invasive capacity. CONCLUSION: The data indicate that HCGbeta is directly responsible for changes in prostate carcinoma cells associated with an increased metastatic phenotype.     

Nuclear type II sites and malignant cell proliferation: inhibition by 2,6-bis-benzylidenecyclohexanones.

Methyl-p-hydroxyphenyllactate (MeHPLA) is a bioflavonoid and/or tyrosine metabolite which may regulate cellular growth and proliferation through interactions with nuclear type II sites. Our current studies suggest that type II sites may function as MeHPLA receptors which are localized on the nuclear matrix, and occupancy of this binding site by MeHPLA directly correlates with the inhibition of normal and malignant cell proliferation. This ligand is inactivated by MeHPLA esterase in mammary tumors, resulting in a deficiency in MeHPLA, high quantities of unoccupied type II sites, and uncontrolled cellular proliferation. For these reasons we synthesized 2,6-bis((3,4-dihydroxyphenyl)methylene)-cyclohexanone (BDHPC) and 2,6-bis((3-methoxy-4-hydroxyphenyl)-methylene)cyclohexanone (BMHPC) for assessment as nuclear type II site and cell growth antagonists. These two esterase stable cyclohexanone derivatives, which bind to nuclear type II sites with high affinity (Kd 1-7 nM), mimic MeHPLA as cell growth-regulating agents. Dose-dependent occupancy of type II sites in MCF-7 human cells by BDHPC and BMHPC directly correlated with the inhibition of cell proliferation, and administration of BDHPC by silastic implant inhibited mouse mammary tumor growth in vivo. These findings demonstrate that esterase-stable type II antagonists such as BDHPC and BMHPC inhibit mammary cancer cell proliferation in vitro and in vivo and support earlier studies demonstrating that MeHPLA and functionally related compounds may regulate malignant cell proliferation at the level of this binding site.     

Isoforms of endothelin-converting enzyme-1 (ECE-1) have opposing effects on prostate cancer cell invasion

Cross-talk between tumour and stromal cells can profoundly influence cancer cell invasion by increasing the availability of mitogenic peptides such as endothelin-1 (ET-1). Endothelin-1 is elevated in men with metastatic prostate cancer (PC), and can exert both an autocrine (epithelial) and a paracrine (stromal) influence on growth. Endothelin-1 is generated from its inactive precursor big-ET-1 by endothelin-converting enzyme 1 (ECE-1). We and others have demonstrated that ECE-1 expression is significantly elevated in tumours and surrounding stromal tissue. Our current data show siRNA-mediated knockdown of stromal ECE-1 reduces epithelial (PC-3) cell invasion in coculture. Interestingly, readdition of ET-1 only partially recovers this effect suggesting a novel role for ECE-1 independent of ET-1 activation. Parallel knockdown of ECE-1 in both stromal and epithelial compartments results in an additive decrease in cell invasion. We extrapolated this observation to the four recognised isoforms ECE-1a, ECE-1b, ECE-1c and ECE-1d. Only ECE-1a and ECE-1c were significant but with reciprocal effects on cell invasion. Transient ECE-1c overexpression increased PC-3 invasiveness through matrigel, whereas transient ECE-1a expression suppressed invasion. Furthermore, transient ECE-1a expression in stromal cells strongly counteracts the effect of transient ECE-1c expression in PC-3 cells. The ECE-1 isoforms may, therefore, be relevant targets for antiinvasive therapy in prostate and other cancers.     

Androgen receptor non-nuclear regulation of prostate cancer cell invasion mediated by Src and matriptase

Castration-resistant prostate cancers still depend on nuclear androgen receptor (AR) function despite their lack of dependence on exogenous androgen. Second generation anti-androgen therapies are more efficient at blocking nuclear AR; however resistant tumors still develop. Recent studies indicate Src is highly active in these resistant tumors. By manipulating AR activity in several different prostate cancer cell lines through RNAi, drug treatment, and the use of a nuclear-deficient AR mutant, we demonstrate that androgen acting on cytoplasmic AR rapidly stimulates Src tyrosine kinase via a non-genomic mechanism. Cytoplasmic AR, acting through Src enhances laminin integrin-dependent invasion. Active Matriptase, which cleaves laminin, is elevated within minutes after androgen stimulation, and is subsequently shed into the medium. Matriptase activation and shedding induced by cytoplasmic AR is dependent on Src. Concomitantly, CDCP1/gp140, a Matriptase and Src substrate that controls integrin-based migration, is activated. However, only inhibition of Matriptase, but not CDCP1, suppresses the AR/Src-dependent increase in invasion. Matriptase, present in conditioned medium from AR-stimulated cells, is sufficient to enhance invasion in the absence of androgen. Thus, invasion is stimulated by a rapid but sustained increase in Src activity, mediated non-genomically by cytoplasmic AR, leading to rapid activation and shedding of the laminin protease Matriptase.     

Detection of polyoma-virus-induced tumor antigen(s) by macrophage migration inhibition

In order to investigate a possible correlation beween in vitro transformation and tumorigenicity in ovo, a new temperature-sensitive class T mutant of Rous Sarcoma Virus was isolated with a lower (39·5C) restrictive temperature for morphological transformation. This lower restrictive temperature was compatible with the survival of chicken and duck eggs for the tumorigenicity studies. In chicken embryo fibroblasts (CEF) infected by this new mutant, PA 17, and cultured at 39·5C, increase of hexose uptake, plasminogen activator production and anchorageindependent growth were only partially restricted, requiring incubation at 41·5C for a complete shut-off. Tumorigenicity in chicken and duck eggs inoculated with CEF infected and transformed by PA 17 was restricted at 39·5C, correlating well with the restriction of morpholgical transformation at this temperature. The kinase activity of the transforming protein pp in lysates of PA 17 infected cells cultured at permissive or restrictive temperatures was labile in RIPA buffer, as in the case of some previously examined tsT mutants. In the non-ionic detergent NP40 buffer, the kinase activity of PA 17 infected cell lysates was better conserved and showed a moderate temperature dependence. These results suggest that, in spite of the correlations between the transformed cell phenotype in vitro and cell tumorigenicity in ovo, it is difficult to establish a quantitative relationship.     

Inhibition of tumor cell invasion by ubenimex (bestatin) in vitro

We have investigated the effect of the immunomodulator ubenimex (bestatin) on tumor cell invasion of reconstituted basement membrane (Matrigel). The invasion of B16-BL6 melanoma cells and Lewis lung carcinoma (3LL) cells into Matrigel-coated filters was inhibited by the presence of bestatin in a concentration-dependent manner. The pretreatment of either tumor cells or Matrigel with bestatin, however, had little effect on the invasion of tumor cells. Since bestatin was found to inhibit amino-peptidase in addition to its immunomodulating activities, the inhibition of tumor invasion by bestatin is likely to be associated with the action as an enzyme inhibitor. Other aminopeptidase inhibitors, arphamenine B and amastatin A, could also inhibit tumor cell invasion into Matrigel. Bestatin inhibited hydrolyzing activities towards substrates of aminopeptidases in B16-BL6 melanoma cells. However, bestatin did not have any effect on the haptotactic migration and adhesion of tumor cells to the substrates. These results indicated that bestatin may inhibit tumor cell invasion through a mechanism involving its inhibitory action on aminopeptidases in tumor cells.     

Lack of inhibition by retinoids of bis(2-oxopropyl)nitrosamine-induced carcinogenesis in Syrian hamsters

Syrian hamsters were treated with either a low (10 mg/kg bodyweight) or high (40 mg/kg body weight) single dose of bis(2-oxopropyl)nitrosamine(BOP) and beginning 1 week later fed either low (0.2 mmol/kgdiet) or high (0.4–1.0 mmol/kg diet) levels of one offour retinoids [13 cis retinoic acid (13-cis-RA), N-ethylretinamide(ERA), N-(2-hydroxy- ethyl)retinamide (OHERA) or N-(phenyl)retinamide(PRA)] for periods of 40 or 50 weeks. The high retinoid levels(0.4–1.0 mmol/kg diet) fed following the highest BOP treatmentenhanced pancreatic carcinoma yields (average number/effectiveanimal) in males fed all four retinoids, and in females fedERA and 13-cis-RA. Enhanced adenoma yields were also seen inall groups when high retinoid levels were fed following 40 mgBOP/kg body weight. However, these retinoid levels caused anincreased adenoma yield in male hamsters only and did not modifycarcinoma yields when fed following 10 mg HOP/kg body weight.Similarly, tumor yields at extra-pancreatic sites were elevatedin refinoid-fed hamsters of both sexes after 40 mg BOP/kg bodyweight and in males fed ERA and 13-cis-RA after 10 mg BOP/kgbody weight when retinoids were given at the high levels (0.4–1.0mmol/kg diet). Increased incidences of bile duct and liver tumorsin particular were found in hamsters given 40 mg BOP/kg bodyweight. Consumption of retinoid levels of 0.4 mmol/kg diet andabove was also associated with a high incidence of liver cellnecrosis, ovarian cysts and ovarian hemorrhage. Retinoids (ERA,OHERA, and PRA) fed at the low level (0.2 mmol/kg diet) followingthe low BOP dose did not enhance carcinogenesis in the pan creasor at other sites and did not cause alterations in morphologicobservations.     

SRC激酶抑制剂对前列腺癌细胞侵袭与增殖的影响

目的:以PP2[4-Amino-5-(4-Chloro-Phenyl)-7-(t-Butyl)Pyrazolo(3,4-d)Pyrimidine]药物(src激酶抑制剂)处理前列腺癌细胞,检测src激酶及E-cadherin蛋白表达水平的变化,探讨PP2对前列腺癌细胞增殖和侵袭能力的影响。方法:PP2处理前列腺癌细胞PC-3,Western blot检测src及其相关蛋白的表达;Boyden小室实验检测细胞侵袭能力;MTT检测细胞的增殖能力。结果:PP2处理PC-3细胞后,src表达水平明显降低,E-cadherin表达水平升高;细胞的增殖和侵袭能力均受到明显抑制,剂量越高抑制作用越明显(P<0.05)。结论:PP2通过提高细胞黏附分子E-cadherin的表达抑制前列腺癌细胞PC-3的增殖和侵袭能力。     

SRC激酶抑制剂对前列腺癌细胞侵袭与增殖的影响

目的：以PP2[4-Amino-5-（4-Chloro-Phenyl）-7-（t-Butyl）Pyrazolo（3,4-d）Pyrimidine]药物（src激酶抑制剂）处理前列腺癌细胞,检测src激酶及E-cadherin蛋白表达水平的变化,探讨PP2对前列腺癌细胞增殖和侵袭能力的影响。方法：PP2处理前列腺癌细胞PC-3,Western blot检测src及其相关蛋白的表达;Boyden小室实验检测细胞侵袭能力;MTT检测细胞的增殖能力。结果：PP2处理PC-3细胞后,src表达水平明显降低,E-cadherin表达水平升高;细胞的增殖和侵袭能力均受到明显抑制,剂量越高抑制作用越明显（P〈0.05）。结论：PP2通过提高细胞黏附分子E-cadherin的表达抑制前列腺癌细胞PC-3的增殖和侵袭能力。