Cell cycle effects of nonsteroidal anti-inflammatory drugs and enhanced growth inhibition in combination with gemcitabine in pancreatic carcinoma cells

Increased cyclooxygenase-2 (COX-2) expression in human pancreatic adenocarcinomas, as well as the growth-inhibitory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in vitro, suggests that NSAIDs may be an effective treatment for pancreatic cancer. Gemcitabine is currently the most effective chemotherapeutic drug available for patients with pancreatic cancer, but is only minimally effective against this aggressive disease. Clearly, other treatment options must be identified. To design successful therapeutic strategies involving compounds either alone or in combination with others, it is necessary to understand their mechanism of action. In the present study, we evaluated the effects of three NSAIDs (sulindac, indomethacin, and NS-398) or gemcitabine in two human pancreatic carcinoma cell lines, BxPC-3 (COX-2-positive) and PaCa-2 (COX-2-negative), previously shown to be growth-inhibited by these NSAIDs. Effects on cell cycle and apoptosis were investigated by flow cytometry or Western blotting. Treatment with NSAIDs or gemcitabine altered the cell cycle phase distribution as well as the expression of multiple cell cycle regulatory proteins in both cell lines, but did not induce substantial levels of apoptosis. Furthermore, we demonstrated that the combination of the NSAID sulindac or NS-398 with gemcitabine inhibited cell growth to a greater degree than either compound alone. These results indicate that the antiproliferative effects of NSAIDs and gemcitabine in pancreatic tumor cells are primarily due to inhibition of cell cycle progression rather than direct induction of apoptotic cell death, regardless of COX-2 expression. In addition, NSAIDs in combination with gemcitabine may hold promise in the clinic for the treatment of pancreatic cancer.     

Potential involvement of the cyclooxygenase-2 pathway in the regulation of tumor-associated angiogenesis and growth in pancreatic cancer

Angiogenesis plays a crucial role in tumor development and growth. The present investigation was undertaken to test the potential involvement of the cyclooxygenase-2 (COX-2) pathway in the regulation of angiogenesis and growth in pancreatic cancer. We compared the angiogenic characteristics of a COX-2-positive human pancreatic tumor cell line, BxPC-3, with those of a COX-2-negative pancreatic tumor cell line, AsPC-1. Cultured BxPC-3 cells promoted a marked increase of endothelial cell migration in comparison with migration that occurred in the absence of cancer cells. Furthermore, BxPC-3 cell culture supernatants induced endothelial cell capillary morphogenesis in vitro and neovascularization in vivo. In contrast, cultured AsPC-1 cells elicited a modest effect on endothelial cell migration and neovascularization in vivo. Pretreatment of BxPC-3 cells with the selective COX-2 inhibitor NS-398 (50 micro M) dramatically decreased angiogenic responses of endothelial cells. NS-398 (25-100 micro M) caused inhibition of BxPC-3 cell proliferation but had no effect on AsPC-1 cell growth. SC-560, a selective COX-1 inhibitor, had no effect on growth of either cell lines. These results suggest an involvement of COX-2 in the control of tumor-dependent angiogenesis and growth in certain pancreatic cancers and provide the rational for inhibition of the COX pathway as an effective therapeutic approach for pancreatic tumors.     

EFFECTS OF p53 GENE THERAPY COMBINED WITH CYCLOOXYGENASE-2 INHIBITOR ON CYCLOOXYGENASE-2 GENE EXPRESSION AND GROWTH INHIBITION OF HUMAN LUNG CANCER CELLS

1 INTRODUCTIONCOXis the key enzyme involved in the synthesis of prostanoids,a collective termfor the PGs andthromboxanes.Of the two major isoforms of the COXenzyme,COX-1 is ubiquitous and constitutively ex-pressedin virtually all normal tissues.In contras…     

Cyclooxygenase-independent down-regulation of multidrug resistance-associated protein-1 expression by celecoxib in human lung cancer cells

The recent finding of a link between cyclooxygenase-2 (COX-2) and p-glycoprotein expression suggests that COX-2 is involved in the development of the multidrug resistance (MDR) phenotype. MDR-associated protein 1 (MRP1) is another major MDR-related protein that is frequently overexpressed in cancer patients, including those with lung cancer. Based on our observation that among four human epithelial lung cell lines both MRP1 and COX-2 protein were highly expressed only in A549 cells, we have investigated whether COX-2 regulates the expression of MRP1. The COX-2 inhibitor celecoxib down-regulated the expression of MRP1 protein in A549 cells, which was accompanied by increased accumulation and enhanced cytotoxicity of doxorubicin, an MRP1 substrate. However, enforced expression of COX-2 in human H460 lung carcinoma cell lines, which express minimal level of COX-2, did not cause enhancement in MRP1 expression. Celecoxib down-regulation of MRP1 was observed independent of COX-2 expression. Moreover, in COX-2-overexpressing cell lines, celecoxib down-regulation of MRP1 was observed only at a concentration far exceeding that required for inhibiting COX activity, and exogenous addition of prostaglandin E(2) did not restore MRP1 expression. These results suggest that celecoxib down-regulates MRP1 expression in human lung cancer cells in a COX-independent manner. The use of celecoxib for adjuvant therapy in lung cancer patients may contribute to their decreased resistance to chemotherapeutic drugs transported by MRP1.     

Critical role of prostate apoptosis response-4 in determining the sensitivity of pancreatic cancer cells to small-molecule inhibitor-induced apoptosis

Role of prostate apoptosis response-4 (PAR-4) has been well described in prostate cancer. However, its significance in other cancers has not been fully elucidated. For the current study, we selected four pancreatic cancer cell lines (BxPC-3, Colo-357, L3.6pl, and HPAC) that showed differential endogenous expression of PAR-4. We found that nonpeptidic small-molecule inhibitors (SMI) of Bcl-2 family proteins (apogossypolone and TW-37; 250 nmol/L and 1 mumol/L, respectively) could induce PAR-4-dependent inhibition of cell growth and induction of apoptosis. Sensitivity to apoptosis was directly related to the expression levels of PAR-4 (R = 0.92 and R(2) = 0.95). Conversely, small interfering RNA against PAR-4 blocked apoptosis, confirming that PAR-4 is a key player in the apoptotic process. PAR-4 nuclear localization is considered a prerequisite for cells to undergo apoptosis, and we found that the treatment of Colo-357 and L3.6pl cells with 250 nmol/L SMI leads to nuclear localization of PAR-4 as confirmed by 4',6-diamidino-2-phenylindole staining. In combination studies with gemcitabine, pretreatment with SMI leads to sensitization of Colo-357 cells to the growth-inhibitory and apoptotic action of a therapeutic drug, gemcitabine. In an in vivo setting, the maximum tolerated dose of TW-37 in xenograft of severe combined immunodeficient mice (40 mg/kg for three i.v. injections) led to significant tumor inhibition. Our results suggest that the observed antitumor activity of SMIs is mediated through a novel pathway involving induction of PAR-4. To our knowledge, this is the first study reporting SMI-mediated apoptosis involving PAR-4 in pancreatic cancer. [Mol Cancer Ther 2008;7(9):2884-93].     

In vitro and in vivo inhibitory effect evaluation of cyclooxygenase-2 inhibitors,antisense cyclooxygenase-2 cDNA,and their combination on the growth of human bladder cancer cells

Overexpression of cyclooxygenase (COX)-2 is associated with the progression of various malignancies, but the contribution of COX-2 expression, bioactivity or their cooperation to bladder cancer growth calls for further clarification. In this study, we investigated the inhibitory effect of COX-2 inhibitors, antisense COX-2 nucleotide, and their combination on the growth of bladder cancer cells (5637, 5637-P and 5637-AS). Suppression of either COX-2 expression or activity caused reduced cell proliferation, enhanced cell numbers in G₁ phase, and increased apoptosis; the joint suppression of COX-2 expression and bioactivity enhanced the degree of cell growth inhibition. COX-2 antisense-expressing 5637-AS tumors showed a 41.42 ± 3.08% growth inhibition as compared with 5637 controls. Oral administration of indomethacin (3 mg/kg) or celecoxib (15 mg/kg) caused tumor growth inhibition by 31.5 ± 14.87% or 83.17 ± 1.17%, respectively. When COX-2 antisense cDNA and COX-2 inhibitor celecoxib were combined, the tumor growth inhibition rate was further increased up to 88.78 ± 3.10%. These results provide evidence that celecoxib has potential therapeutic effect on bladder cancer, and the joint use of COX-2 antisense cDNA with celecoxib may improve their individual therapeutic effect, especially significantly increase the growth inhibitory effect of COX-2 antisense cDNA.     

塞来昔布对人白血病细胞株HL-60细胞增殖及凋亡的影响及其作用机制

本研究旨在探讨塞来昔布（celecoxib）对人急性髓系白血病细胞株HL-60细胞增殖、凋亡的影响及其可能的作用机制。不同浓度塞来昔布作用于HL-60细胞24h后,CCK-8法测定细胞增殖活性,流式细胞技术分析细胞凋亡及细胞周期分布的变化,定量RT—PCR的方法检测细胞周期蛋白DJ、EI及COX-2mRNA的表达。结果表明,不同浓度塞来昔布作用于HL-60细胞24h后,细胞增殖明显受抑,且呈-定的浓度依赖性（r=0．955）,24h的IC50值为63．037μmol／L。塞来昔布可诱导HL-60细胞的凋亡,也呈剂量依赖性（r=0．988）。塞来昔布可使HL-60细胞明显阻滞于G0／G1期,可下调cyclinD1、cyclinE1mRNA的表达。塞来昔布可使细胞COX-2mRNA表达水平降低。结论：塞来昔布呈浓度依赖性抑制HL-60细胞增殖,并可能通过下调cyclinD1、cyclinE1的表达引起细胞G0／G1,期阻滞,下调COX-2的表达诱导细胞凋亡。     

塞来昔布联合 PDTC 对人结肠癌细胞 HT-29 的抑制增殖和促凋亡作用及其机制

目的研究塞来昔布联合吡咯烷二硫氨基甲酸（PDTC）对人结肠癌细胞HT-29增殖、凋亡的影响及其对COX-2、NF-κB、Caspase-3基因表达的影响,探讨塞来昔布联合用药抗肿瘤的机制。方法用不同浓度的塞来昔布（30、60、120、240μmol／L）（单药组）以及不同浓度塞来昔布联合不同浓度的PDTC（50、100μmol／L）（联合组）分别处理人结肠癌细胞,采用CCK-8法检测细胞的增殖情况,流式细胞术分析细胞凋亡情况,实时荧光定量PCR检测各组细胞COX-2、NF-κB、Caspase-3表达的变化。结果塞来昔布单药组对结肠癌细胞具有抑制增殖、促进凋亡作用,其作用随着药物浓度、给药时间的增加而增强（P均〈0．05）;同时检测到COX-2、NF-κBKBmRNA的表达降低（P均〈0．05）,Caspase-3表达升高（P〈0．05）,且具有浓度依赖性;联合组较同一塞来昔布浓度的单药组上述作用更明显（P均〈0．05）。结论塞来昔布单药组和联合组均能抑制人结肠癌细胞的增殖,促进其凋亡;联合组作用强于单药组;其机制可能与COX-2、NF-κB的下调和Caspase-3表达上调有关。     

Suppression of pancreatic tumor growth by combination chemotherapy with sulindac and LC-1 is associated with cyclin D1 inhibition in vivo

The design of novel targeted or combination therapies may improve treatment options for pancreatic cancer. Two targets of recent interest are nuclear factor-kappaB (NF-kappaB) and cyclooxygenase (COX), known to be activated or overexpressed, respectively, in pancreatic cancer. We have previously shown that parthenolide, a proapoptotic drug associated with NF-kappaB inhibition, enhanced the growth suppression of pancreatic cancer cells by the COX inhibitor sulindac in vitro. In the present study, a bioavailable analogue of parthenolide, LC-1, and sulindac were evaluated in vivo using a xenograft model of human pancreatic cancer. Treatment groups included placebo, low-dose/high-dose LC-1 (20 and 40 mg/kg), low-dose/high-dose sulindac (20 and 60 mg/kg), and low-dose combination LC-1/sulindac (20 mg/kg each). In MiaPaCa-2 xenografts, tumor growth was inhibited by either high-dose sulindac or LC-1. In BxPC-3 xenografts, tumor size was significantly reduced by treatment with the low-dose LC-1/sulindac combination or high-dose sulindac alone (P < 0.05). Immunohistochemistry of BxPC-3 tumors revealed a significant decrease in Ki-67 and CD31 staining by high-dose sulindac, with no significant changes in COX-1/COX-2 levels or activity in any of the treatment groups. NF-kappaB DNA-binding activity was significantly decreased by high-dose LC-1. Cyclin D1 protein levels were reduced by the low-dose LC-1/sulindac combination or high-dose sulindac alone, correlating with BxPC-3 tumor suppression. These results suggest that LC-1 and sulindac may mediate their antitumor effects, in part, by altering cyclin D1 levels. Furthermore, this study provides preclinical evidence for the therapeutic efficacy of these agents.     

Enhancing antitumor effects in pancreatic cancer cells by combined use of COX-2 and 5-LOX inhibitors

Cyclooxygenase (COX)-2 and lipoxygenase (LOX)-5 are involved in carcinogenesis of pancreatic cancer. COX-2 inhibitor celecoxib displays inhibitory effects in pancreatic cancer cell growth. Recently, it has been reported that COX-2 inhibitor may not be able to suppress pancreatic tumor growth in vivo and its application is further limited by untoward side effects. The present study provides evidence that combined use of celecoxib and 5-LOX inhibitor MK886 markedly suppresses pancreatic tumor cell growth in vitro. Compared to the single inhibitor treatment, dual treatment with celecoxib and MK886 exerted additive antitumor effects in pancreatic tumor cells. We found that MK886 reversed celecoxib-induced increases in 5-LOX gene expression and Erk1/2 activation in pancreatic tumor cells. Moreover, Dual treatment of pancreatic tumor cells with celecoxib and MK886 inhibited the levels of LBT4 receptor BLT1 and vascular endothelial growth factor. Our results imply that combined use of celecoxib and MK886 might be an effective way to treat clinical patients with pancreatic cancer.     

Cyclooxygenase-2 dependent and independent antitumor effects induced by celecoxib in urinary bladder cancer cells

Transitional cell carcinoma of the urinary bladder is the second most common genitourinary malignancy in people in the United States. Cyclooxygenase-2 (COX-2) is overexpressed in bladder cancer. COX-2 inhibitors have had antitumor activity against bladder cancer, but the mechanisms of action are unclear. Clinically relevant concentrations of COX-2 inhibitors fail to inhibit proliferation in standard in vitro assays. In pilot experiments, different culture conditions [standard monolayer, modified monolayer, soft agar, collagen, and poly(2-hydroxyethyl methacrylate)-coated plates] were assessed to determine conditions suitable for the study of COX inhibitor growth-inhibitory effects. This was followed by studies of the effects of clinically relevant concentrations of a selective COX-2 inhibitor (celecoxib) on urinary bladder cancer cell lines (HT1376, TCCSUP, and UMUC3). Celecoxib (相似文献   

Selective inhibition of cyclooxygenase-2 suppresses the growth of pancreatic cancer cells in vitro and in vivo

Cyclooxygenase-2 (COX-2), a prostaglandin synthetase, is involved in development of certain tumors. We therefore analyzed COX-2 expression in pancreatic cancer tissues (53 samples) and Panc-1 human pancreatic cancer cells by immunohistochemistry, RT-PCR and western-blotting analyses. Also, immunohistochemistry of proliferating cell nuclear antigen (PCNA) was performed. We found expression of COX-2 was dramatically upregulated in 36 of 53 cases (67.9%) and the expression of COX-2 was associated with the diameter (> 3 cm) of the tumors (p < 0.05), but not with the age, gender, tumor location, differentiation, lymph-node metastases and TNM stage. The positivity rate of PCNA expression in the pancreatic cancer cells of the COX-2 positive group (32.88 +/- 13.26%) was significantly higher than that in the COX-2 negative group (24.56 +/- 11.51%) (p < 0.05). Then we investigated the effect of selective inhibitors of COX-2 (NS398 and celecoxib) on proliferation of Panc-1 cells by 3-(4,5 dimethyl-2-thiazolyl)-2.5-diphenyl-2H-tetrazolium bromide (MTT) assay. Either NS398 or celecoxib suppressed proliferation of Panc-1 cells dose-dependently in vitro. Furthermore, Panc-1 cells were implanted into nude mice, and celecoxib was administrated orally with feed. The volume of the tumor xenografted into nude mice was decreased by 51.6% in the celecoxib group (p < 0.01). In conclusion, the increased expression of COX-2 may be responsible for rapid proliferation of pancreatic cancer, and specific inhibition of COX-2 suppresses proliferation of Panc-1 cells in vitro and in nude mice. The selective inhibitor of COX-2 may be an effectual agent for pancreatic cancer chemoprevention.     

Biochemistry of cyclooxygenase (COX)-2 inhibitors and molecular pathology of COX-2 in neoplasia

Several types of human tumors overexpress cyclooxygenase (COX) -2 but not COX-1, and gene knockout transfection experiments demonstrate a central role of COX-2 in experimental tumorigenesis. COX-2 produces prostaglandins that inhibit apoptosis and stimulate angiogenesis and invasiveness. Selective COX-2 inhibitors reduce prostaglandin synthesis, restore apoptosis, and inhibit cancer cell proliferation. In animal studies they limit carcinogen-induced tumorigenesis. In contrast, aspirin-like nonselective NSAIDs such as sulindac and indomethacin inhibit not only the enzymatic action of the highly inducible, proinflammatory COX-2 but the constitutively expressed, cytoprotective COX-1 as well. Consequently, nonselective NSAIDs can cause platelet dysfunction, gastrointestinal ulceration, and kidney damage. For that reason, selective inhibition of COX-2 to treat neoplastic proliferation is preferable to nonselective inhibition. Selective COX-2 inhibitors, such as meloxicam, celecoxib (SC-58635), and rofecoxib (MK-0966), are NSAIDs that have been modified chemically to preferentially inhibit COX-2 but not COX-1. For instance, meloxicam inhibits the growth of cultured colon cancer cells (HCA-7 and Moser-S) that express COX-2 but has no effect on HCT-116 tumor cells that do not express COX-2. NS-398 induces apoptosis in COX-2 expressing LNCaP prostate cancer cells and, surprisingly, in colon cancer S/KS cells that does not express COX-2. This effect may due to induction of apoptosis through uncoupling of oxidative phosphorylation and down-regulation of Bcl-2, as has been demonstrated for some nonselective NSAIDs, for instance, flurbiprofen. COX-2 mRNA and COX-2 protein is constitutively expressed in the kidney, brain, spinal cord, and ductus deferens, and in the uterus during implantation. In addition, COX-2 is constitutively and dominantly expressed in the pancreatic islet cells. These findings might somewhat limit the use of presently available selective COX-2 inhibitors in cancer prevention but will probably not deter their successful application for the treatment of human cancers.     

环氧合酶2抑制剂塞来昔布对结肠癌多药耐药逆转作用的研究

目的 探讨环氧合酶2(COX-2)抑制剂塞来昔布对结肠癌多药耐药(MDR)的逆转作用.方法 在结肠癌多药耐药细胞株colo320/5-FU中,应用四甲基偶氮唑蓝(MTT)方法检测塞来昔布时5-氟尿嘧啶(5-FU)的耐药逆转倍数;反转录-聚合酶链反应(RT-PCR)方法检测耐药基因的变化;免疫组织化学法检测细胞膜跨膜蛋白p-170(P-gP)的表达.结果 MTT结果显示塞来昔布对结肠癌细胞的耐药产生明显的逆转作用(F=2285.660,P＜0.01),其逆转倍数分别为1.70,3.80,8.48,且呈浓度依赖性.RT-PCR结果显示塞来昔布明显抑制多药耐药基因1(MDR1)mRNA的表达(F=986.776,P＜0.01),且呈浓度依赖性减低,各浓度组之间差异有统计学意义(P＜0.01).免疫荧光结果显示,细胞膜P-gp荧光强度随着塞来昔布浓度的逐渐增高而减弱.结论 选择性COX-2抑制剂塞来昔布对多药耐药细胞株colo320/5-FU具有明显逆转作用,在非细胞毒剂量范围内呈现剂量依赖性,初步机制可能涉及干预多种转录因子的表达而下调MDR1,继而阻滞细胞周期及增加细胞凋亡.     

Inhibition of 5-lipoxygenase by MK886 augments the antitumor activity of celecoxib in human colon cancer cells

Cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LOX) are key enzymes involved in arachidonic acid metabolism. Their products, prostaglandins and leukotrienes, are involved in colorectal tumor development. We aimed at evaluating whether combined blocking of the COX-2 and 5-LOX pathways might have additive antitumor effects in colorectal cancer. The expression/activity of COX-2 and 5-LOX were assessed in 24 human colorectal cancer specimens. The effects of the COX-2 inhibitor celecoxib and the 5-LOX inhibitor MK886 on prostaglandin E(2) and cysteinyl leukotriene production, tumor cell proliferation, cell apoptosis, and Bcl-2/Bax expression were evaluated in the Caco-2 and HT29 colon cancer cells. We also investigated the effect of the enzymatic inhibition on mitochondrial membrane depolarization, one of the most important mechanisms involved in ceramide-induced apoptosis. Up-regulation of the COX-2 and 5-LOX pathways was found in the tumor tissue in comparison with normal colon mucosa. Inhibition of either COX-2 or 5-LOX alone resulted in activation of the other pathway in colon cancer cells. Combined treatment with 10 micromol/L celecoxib and MK886 could prevent this activation and had additive effects on inhibiting tumor cell proliferation, inducing cell apoptosis, decreasing Bcl-2 expression, increasing Bax expression, and determining mitochondrial depolarization in comparison with treatment with either inhibitor alone. The administration of the ceramide synthase inhibitor fumonisin B1 could prevent some of these antineoplastic effects. In conclusion, our study showed that inhibition of 5-LOX by MK886 could augment the antitumor activity of celecoxib in human colorectal cancer.     

microRNA-301在胰腺癌中的表达及其临床意义

目的 分析miR-301在胰腺癌组织中的表达,探讨其在胰腺癌侵袭转移中的意义.方法 用FQ-PCR方法从细胞水平检测5种胰腺癌细胞系(PANC-1、PaCa-2、AsPC-1、Hs-766T、BxPC-3)中miR-301的表达;进一步用免疫组织化学方法从组织水平检测胰腺癌组织芯片(含60份胰腺癌组织、10份癌旁组织和10份正常胰腺组织)中miR-301的表达;在证实miR-301高表达后,进一步研究其在胰腺癌侵袭转移中的临床意义,用100 nmol/L miR-301抑制剂(anti-miR-301)或阴性对照(Anti-miR~(TM) Negative Control#1)处理对数生长的胰腺癌细胞系PANC-1、PaCa-2,用WB检测胰腺癌细胞系中侵袭转移相关分子COX-2、MMP-2的表达,并用Transwell技术检测胰腺癌细胞的侵袭转移能力.结果 FQ-PCR检测结果显示,在5种胰腺癌细胞系PANC-1、PaCa-2、AsPC-1、Hs-766T、BxPC-3中miR-301的相对表达量分别为33.09±4.21、30.76±3.18、47.57±3.56、20.20±1.21、76.75±13.51;而正常胰腺细胞中为1.00±0.08;5种胰腺癌细胞系分别与正常胰腺细胞相比,差异有统计学意义(t值分别为8.86、9.53、6.39、6.77、11.18,P均<0.01).免疫组织化学结果亦显示,胰腺癌组织、癌旁组织及正常胰腺组织中miR-301的相对表达量分别为0.88±0.09、0.22±0.04、0.14±0.05;胰腺癌组织分别与癌旁组织及正常胰腺组织相比,差异有统计学意义(t值分别为15.1、10.6,P均<0.01);正常胰腺组织与癌旁组织相比,差异无统计学意义(t=1.32,P=0.22).用miR-301抑制剂抑制胰腺癌细胞系PANC-1、PaCa-2中miR-301的表达后,WB检测结果显示,侵袭转移相关分子COX-2、MMP-2的表达下调;细胞侵袭转移能力试验结果显示,miR-301抑制剂处理后跨膜转移的细胞数分别为PANC-1(587±27)个、PaCa-2(363±13)个,而阴性对照处理后跨膜转移的细胞数为:PANC-1(1 091±15)个、PaCa-2(737±44)个;miR-301抑制剂处理与阴性对照处理相比,细胞侵袭转移能力亦显著下降(t值分别为7.89、7.56,P均<0.01).结论 胰腺癌细胞系和组织中miR-301高表达;且与胰腺癌的侵袭转移密切相关,抑制miR-301的表达能够有效抑制胰腺癌细胞的侵袭转移,miR-301有望成为抗胰腺癌侵袭转移治疗的新分子靶标和胰腺癌早期诊断的新分子标志.