lncRNA 178030.2通过TRPS1对三阴性乳腺癌细胞紫杉醇耐药的影响与机制研究

目的:探讨lncRNA 178030.2通过TRPS1对三阴性乳腺癌细胞紫杉醇耐药的影响与机制。方法:采用逐步增加剂量间歇作用的方法诱导三阴性乳腺癌紫杉醇耐药细胞系并命名为MDA-MB-231/R。采用定量PCR和Western blot检测耐药细胞和亲本细胞中lncRNA 178030.2和TRPS1的表达;应用Lipofectamine 2000将lncRNA 178030.2高表达质粒pcmv-178030.2和对照质粒pcmv转染至MDA-MB-231细胞,分别为高表达组和对照组,定量PCR检测lncRNA 178030.2水平的变化,分别用定量PCR和Western blot检测TRPS1 mRNA及蛋白水平的变化;RIP实验检测lncRNA 178030.2是否与TRPS1相结合;MTT法检测MDA-MB-231细胞对紫杉醇的敏感性及细胞增殖。应用Lipofectamine 2000将lncRNA 178030.2小干扰RNA si178030.2和对照siNC转染至MDA-MB-231/R细胞,分别为干扰组和对照组,定量PCR检测lncRNA 178030.2水平的变化,分别用定量PCR和Western blot检测TRPS1 mRNA及蛋白水平的变化;MTT法检测MDA-MB-231/R细胞对紫杉醇的敏感性及细胞增殖。应用Lipofectamine 2000将TRPS1过表达质粒pcmv-TRPS1和对照质粒pcmv转染至MDA-MB-231细胞,分别为高表达组和对照组,分别用定量PCR和Western blot检测两组细胞中TRPS1 mRNA及蛋白水平的表达情况,然后再分别应用Lipofectamine 2000将lncRNA 178030.2高表达质粒pcmv-178030.2转染入两组细胞,MTT法检测MDA-MB-231细胞对紫杉醇的敏感性及细胞增殖。结果:成功构建在3 μg/ml紫杉醇中稳定生长的三阴性乳腺癌耐药细胞系MDA-MB-231/R。定量PCR结果显示:lncRNA 178030.2在紫杉醇耐药细胞系MDA-MB-231/R中的表达明显高于在其亲本细胞MDA-MB-231中的表达;定量PCR和Western blot显示:TRPS1 mRNA和蛋白在紫杉醇耐药细胞系MDA-MB-231/R中的表达明显低于在其亲本细胞系MDA-MB-231中的表达;与对照组相比,高表达lncRNA 178030.2组的MDA-MB-231细胞中TRPS1表达下降,细胞对紫杉醇的敏感性降低,细胞增殖增强,且lncRNA 178030.2确实可以与TRPS1相结合;与对照组相比,低表达lncRNA 178030.2组的MDA-MB-231/R细胞中TRPS1表达升高,细胞对紫杉醇的敏感性升高,细胞增殖减弱;在MDA-MB-231细胞中过表达TRPS1后再过表达lncRNA 178030.2,其促进紫杉醇耐药、促进细胞增殖的作用也明显减弱。结论:lncRNA 178030.2促进三阴性乳腺癌细胞MDA-MB-231的紫杉醇耐药,促进细胞增殖,其发生机制可能与下调TRPS1的表达有关。     

Superior efficacy of a Cremophor-free albumin-bound paclitaxel compared with solvent-based paclitaxel in Chinese patients with metastatic breast cancer

Aim:   In a previous study, a 130-nm nanoparticle albumin-bound paclitaxel ( nab -paclitaxel) demonstrated improved efficacy and safety profile compared with solvent-based paclitaxel (sb-paclitaxel) in Caucasian patients with metastatic breast cancer (MBC). The aim of the present randomized study was to compare the response rates and safety profile of nab -paclitaxel with sb-paclitaxel in Chinese patients with MBC.
Methods:   In the present open-label, multicenter study, 210 patients with MBC were randomly assigned to receive nab -paclitaxel 260 mg/m² intravenously (i.v.) over 30 min every 3 weeks (q3w) with no premedication or sb-paclitaxel 175 mg/m² i.v. over 3 h q3w with standard premedication.
Results:   The overall response rate was 54 and 29% in patients treated with nab -paclitaxel and sb-paclitaxel, respectively ( P  < 0.001). nab -paclitaxel induced a higher response rate in patients who were <65 years old, patients who were receiving first-line therapy, patients who had no prior anthracycline therapy, patients who had ≤ or >3 metastatic lesions, and patients who had visceral disease. The progression-free survival (PFS) period was 7.6 months for nab -paclitaxel and 6.2 months for sb-paclitaxel ( P  = 0.118). Despite the 49% higher paclitaxel dose in patients receiving nab -paclitaxel compared with patients receiving sb-paclitaxel, the safety profile was similar in both treatment groups. The most common grades 3 and 4 adverse event (AE) in both arms was neutropenia. The most common grade 3 nonhematologic AE was peripheral neuropathy, and no grade 4 peripheral neuropathy was observed.
Conclusion:   Compared with sb-paclitaxel, nab -paclitaxel demonstrated superior efficacy, an acceptable safety profile, and a trend toward increased PFS in patients with MBC.     

Dose-finding study of paclitaxel and cyclophosphamide in advanced breast cancer

Background: The toxicity profile of prolonged infusions of paclitaxel incombination with cyclophosphamide in metastatic breast cancer has already beendefined. The objective of this dose-finding study was to determine the maximumtolerable doses (MTDs) of shorter (three-hour) infusions of paclitaxel incombination with i.v. bolus cyclophosphamide in patients who had previouslyreceived a maximum of one chemotherapy for advanced breast carcinoma. The MTDof the same regimen with granulocyte colony-stimulating factor (G-CSF) supportwas then established.Patients and methods: Eighty women with metastatic breast cancer receiveda total of 352 fully evaluable courses of therapy. The starting doses werepaclitaxel 135 mg/m² and cyclophosphamide 750mg/m² given every three weeks. At least three patients weretreated at each dose level and if there were dose-limiting toxic effectsduring the first cycles three additional patients were entered. G-CSF support(5µg/kg s.c.) was added to the second cycle if specific dose-limitingtoxicitieshad occurred during the first cycle. The MTD was defined as the dose level atwhich more than two of six patients presented dose-limiting toxicities duringthe first cycle.Results: Febrile neutropenia (n = 4) and severe thrombocytopenia (n = 1)defined the MTDs of paclitaxel as 200 mg/m² and ofcyclophosphamide as 2,000 mg/m², with or without G-CSF inpatients with and, respectively, without prior chemotherapy for advanceddisease. Non-hematologic toxicity was moderate. Recommended doses were 200mg/m² of paclitaxel and 1,750 mg/m² ofcyclophosphamide with or without G-CSF in patients with and, respectively,without prior chemotherapy. The overall response rate was 25% and50%, respectively, in patients with and without prior chemotherapy formetastatic disease. Complete remissions (9%) were reported only inpatients without prior chemotherapy; antitumour activity in women withanthracycline-resistant disease, with an 8% response rate (95%CI: 1%–26%), was poor.Conclusions: Paclitaxel at 200 mg/m² and cyclophosphamideat 1,750 mg/m² can be safely administered every three weeksto women with advanced breast cancer. The moderate antitumour activityobserved with the schedule tested argues against its use as initial therapyfor advanced breast cancer.     

三阴性乳腺癌X线特征分析

目的:探讨三阴性乳腺癌的X线特征。方法:收集经手术病理证实为乳腺癌的202例患者资料,根据雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体（HER-2）表达情况将其分为三阴性乳腺癌（TNBC）与非三阴性乳腺癌（NTNBC）,比较两组病例腺体分型、病灶是否单发、肿块情况及有无钙化。结果:202例乳腺癌TNBC有34例,NTNBC有168例。两组病例肿块边缘及有无钙化差异有统计学意义(P均＜0.05)。腺体分型、是否单发、肿块的大小、肿块的形态、肿块的密度差异无统计学意义。结论:TNBC有一定特征,大多为单发肿块,与NTNBC相比肿块边缘更易表现为清晰光滑,钙化相对少见的征象。     

三阴性乳腺癌及其研究进展

三阴性（雌激素、孕激素受体与HER-2均为阴性）乳腺癌是具有特殊生物学行为及临床病理特征的一个乳腺癌亚型,与基底样乳腺癌和BRCA1相关性乳腺癌有一定相关性。此类型乳腺癌对放化疗尚比较敏感,但常规标准治疗疗效欠佳,预后较其他类型乳腺癌差。目前针对其BRCA1、EGFR等基因及其功能异常而开展的相应研究正在进行。     

紫杉醇联合顺铂治疗晚期乳腺癌临床观察

目的：观察紫杉醇联合顺铂（TP方案）治疗蒽环类耐药的复发转移性晚期乳腺癌的疗效与安全性。方法：从2005年6月-2008年6月以TP方案治疗蒽环类耐药的复发转移性晚期乳腺癌28例,紫杉醇135mg／m^2静滴,第1天;顺铂75mg／m^2静滴,第一天,21天为1周期,2个周期末评价近期疗效及安全性。结果：28例患者中CR1例（3．5％）,PR13例（46．4％）,SD8例（28．5％）,PD6例（21．4％）,有效率50％,不良反应主要是骨髓抑制,恶心、呕吐、脱发。结论：TP方案治疗蒽环类耐药的复发转移性晚期乳腺癌疗效可靠,不良反应可耐受,可作为蒽环类耐药的复发转移性晚期乳腺癌的化疗方案。     

DNA损伤修复变异指导铂类药物治疗三阴性乳腺癌的应用前景

三阴性乳腺癌(TNBC)极易复发和远处转移, 是预后最差的乳腺癌亚型, 其主要的治疗手段为化疗, 但目前仍缺乏有效的辅助化疗方案。化疗效果不理想成为阻碍TNBC疗效提高的瓶颈问题。铂类药物作用于细胞DNA, 通过损伤肿瘤细胞DNA, 达到杀灭肿瘤的作用, 对携带DNA损伤修复缺陷的肿瘤细胞有更强的杀伤作用, 成为提高TNBC疗效的重要切入点。寻找能够预测铂类药物在TNBC治疗疗效的生物标志物始终为热点问题之一。DNA损伤修复(DDR)通路包含大量相关基因, DDR通路功能缺失可能与铂类药物疗效相关, 其有望成为预测铂类药物治疗乳腺癌疗效的生物标志物。     

A phase II trial of circadian-timed paclitaxel and cisplatin therapy in metastatic breast cancer

Purpose: In a phase II study with combination paclitaxel and cisplatin inmetastatic breast cancer using circadian timing, we attempted to maximiseresponse and minimise toxicity.Materials and methods: Forty-one patients with histologically-provenmetastatic breast cancer with or without previous chemotherapy were treatedwith Paclitaxel 135 mg/m² administered as a three-hourinfusion at 06.00 hours followed by cisplatin 75 mg/m² as aone-hour infusion at 18.00 hours utilising circadian timing. Six cycles wereplanned once every 21 days. Response assessment was performed every twocycles, and toxicity was measured using WHO criteria.Results: All patients were evaluable for response and toxicity. There werenine (22%) complete responses (CR), and 24 (59%) partialresponses (PR), for an overall response rate of 80% (95%confidence interval (CI) 69–92). Responses were seen in patientspreviously treated with anthracyclines (75%) (95% CI57–92), and in patients who had had no prior chemotherapy (90%)(95% CI 71–100). Responses were seen in all metastatic sites:liver 80%, lung 76%, bone 69%, and soft tissues71%. The overall median response duration was seven months (range3–26, 95% CI 5.0–9.8), and 14 of the responses(42%), (95% CI 28–62) were durable. A total of 212 cyclesof chemotherapy were given. There were 15 episodes (7%) of grade3–4neutropenia, seven (3.2%) of grade 3–4 neurologic toxicity, andthree(1.4%) of grade 3–4 nephrotoxicity. There were no toxic deaths.Conclusion: The combination of paclitaxel and cisplatin is very effectivein metastatic breast cancer, and with application of circadian timing,toxicity has been acceptable. This combination is being tested as primarytherapy in locally-advanced breast cancer at our institution.     

A phase I-II study of bi-weekly paclitaxel as first-line treatment in metastatic breast cancer

Background: Single-agent bi-weekly paclitaxel was studied as first-line metastatic treatment for breast cancer in a phase I–II trial.Patients and methods: Thirty-eight women with metastatic breast cancer were enrolled. Thirty-seven are evaluable for toxicity, 35 for response.Results: The MTD was defined at 160 mg/m2 q two weeks with dose limiting toxicity in two patients consisting of hematological toxicity (1) and neurotoxicity (2). Twenty patients were treated at 150 mg/m2, the recommended dose. Response rates were two CRs and nine PRs (overall 61%) at the RD of 150 mg/m2 and three CRs and 11 PRs for an overall RR of 67% for the two top doses.Conclusions: The good drug tolerance, response rates, and convenience over weekly treatment suggest this may be a worthwhile regimen.     

A phase II clinical trial of weekly paclitaxel and carboplatin in combination with panitumumab in metastatic triple negative breast cancer

Purpose: Women with metastatic triple negative breast cancer (TNBC) can have a poor prognosis with treatment limited to cytotoxic chemotherapy. The identification of effective therapies that may limit exposure to cytotoxic chemotherapy and lead to prolonged survival is an unmet medical need. We tested an inhibitor of the epidermal growth factor receptor, panitumumab in combination with chemotherapy. Methods: We conducted a single arm clinical trial in women with metastatic or locally advanced TNBC to paclitaxel 80 mg/m2 and carboplatin AUC of 2 on days 1, 8, and 15 and panitumumab 6 mg/kg on days 1 and 15 for a cycle length of 28 days. The objectives were to evaluate the response rate and safety of the combination in comparison to historical controls. Results: Fourteen patients with TNBC were enrolled with a median age of 53 years. The majority of women were African American (64.3%) with visceral metastasis (64.2%). Hematologic toxicities, particularly neutropenia and thrombocytopenia, were a major cause of missed chemotherapy and delayed treatment in this study. The overall response rate (complete and partial response) of the 13 evaluable patients was 46%. The median time to best response was 2.4 months and the median time to disease progression was 3.6 months. We were able to perform the PAM50 analysis on tumors from 7 of our subjects. All the samples tested clustered within the basal-like subtype. Conclusions: In our experience the response rate of carboplatin, paclitaxel and panitumumab was consistent with other reports of response for cytotoxic chemotherapy in metastatic TNBC.     

铂类药物用于三阴性乳腺癌的新辅助化疗

三阴性乳腺癌(triple-negative breast cancer,TNBC)作为乳腺癌的一个亚型,其复发率较高而总生存率低。尽管其对于包含蒽环类和紫衫类药物为基础的新辅助化疗方案反应显著,但预后较差。目前尚未发现专门的分子及化疗药物作用靶点。铂类并非是治疗三阴性乳腺癌的常规用药,本文对铂药物用于三阴性乳腺癌新辅助化疗的现状进行综述。     

三阴性乳腺癌分子靶向治疗的研究进展

三阴性乳腺癌(TNBC)是雌激素受体(ER)、孕激素受体(PR)和人表皮生长因子受体2(HER-2)均阴性的乳腺癌,具有独特的病理和分子生物学特性,表现为复发早、进展快、生存期短和预后较其他类型乳腺癌差的特点。除手术治疗外,化疗是其主要的全身治疗手段。目前靶向治疗正逐步应用于乳腺癌的临床治疗中,对TNBC靶向治疗的深入研究,将有助于临床采取有效的治疗方法以提高其疗效。     

贝伐单抗联合白蛋白结合型紫杉醇治疗难治三阴性乳腺癌的初步临床观察

为了评价贝伐单抗联合白蛋白结合型紫杉醇治疗晚期难治性三阴性乳腺癌的临床效果,选取经病理学确诊的晚期三阴性乳腺癌患者6例(ER、PR和HER-2均为阴性),既往使用过蒽环、紫杉类、吉西他滨及卡培他滨等药物治疗后进展,接受贝伐单抗联合白蛋白结合型紫杉醇方案治疗,其中贝伐单抗7.5 mg/kg,静脉滴入,d1,3周重复;白蛋白结合型紫杉醇260 mg/m2,静脉滴入,d1,3周重复,不做抗过敏预处理.3例患者接受化疗6个周期,3例4个周期.PR 2例,SD 3例,PD 1倒.毒副反应主要是骨髓抑制和神经毒性,其中Ⅳ度粒细胞减少1例,Ⅲ度粒细胞减少2倒,Ⅱ度粒细胞减少2倒,Ⅰ度粒细胞减少1例;Ⅲ度感觉神经病变2例,Ⅱ度感觉神经病变2例,Ⅰ度感觉神经病变2例;高血压1倒,蛋白尿2例.初步研究结果提示,贝伐单抗联合白蛋白结合型紫杉醇治疗晚期难治性三阴性乳腺癌疗效较好,毒副反应可耐受,值得进一步研究.     

Reversal effects of Raloxifene on paclitaxel resistance in 2 MDR breast cancer cells

Raloxifene hydrochloride (RAL), one of second generation of selective estrogen receptor modulators (SERMs), is usually used in preventing osteoporosis and breast cancer. The present study evaluated whether Raloxifene might sensitize multidrug resistant (MDR) breast cancers to chemotherapies, especially in estrogen receptor negative (ER−) breast cancer. The results showed that RAL could significantly sensitize ER- MDR breast tumors to paclitaxel both in vitro and in vivo. Combination of Raloxifene could significantly enhance paclitaxel-induced cell apoptosis, G2-M arrest as well as inhibition of cell proliferation in MDR tumors. Further studies showed that the combined treatment did not alter P-glycoprotein expression but increased P-gp ATPase activity. These results suggested that raloxifene might be a valuable chemosensitizer agent for breast cancer therapy.     

Dose intensification of mitoxantrone in combination with paclitaxel in advanced breast cancer: a phase II study

Background: Paclitaxel and mitoxantrone are highly active agents in the treatment of advanced breast cancer (ABC). This study evaluated the combination of paclitaxel and mitoxantrone in patients with advanced breast cancer to determine activity and toxicity.Patients and method: 42 patients with ABC were treated with paclitaxel at a fixed dose of 175mg/m2 intravenous (IV) by a 3hour infusion on day 1, while mitoxantrone was given by 2mg/m2 increments, starting from 10mg/m2 by bolus IV injection on day 1 after paclitaxel. Cycles were repeated every 3 weeks. Mitoxantrone doses were increased if the maximum tolerated dose (MTD) had not been reached.Result: The overall response rate (CR + PR) was 69% (CI 95%: 55–83). Six (14%) patients obtained CR and 23 (55%) PR with a median duration of response of 8 months (range 2–16). There were no differences in response rates (RR) between the three levels of mitoxantrone. Median time to failure and survival were 7 months (range 1–26) and 12 months (range 2–29), respectively. After 12 months 14 (33%) patients had died and 8 (19%) patients were alive after 18 months. MTD was reached at 14mg/m2 level of mitoxantrone. Leukopenia was evident in 39 (93%) of total patients and was severe in 28 (67%) patients. All nonhematological toxicity observed was mild.Conclusion: This trial shows the activity of paclitaxel and mitoxantrone in ABC and finds that a dose of 14mg/m2 of mitoxantrone is the MTD in combination with a fixed dose of 175mg/m2 of paclitaxel without granulocyte colony stimulating factor (GCSF).     

三阴性乳腺癌易患因素的研究进展

三阴性乳腺癌（Triple negative breast cancer,TNBC）是乳腺癌的一种特殊亚型,包括基底样型乳腺癌和未分类型乳腺癌。自从2005年被定义,TNBC在生物学特性上与其他亚型的差异、不良的预后情况就一直是流行病学家,病理学家及临床医生研究的重点与热点。 TNBC的易患因素包括种族、肥胖、年龄、女性生殖期口服避孕药、体育锻炼、流产史、家族史和社会经济因素等。本文主要就种族、肥胖、女性生殖期口服避孕药和年龄对三阴性乳腺癌的影响的最新研究成果进行综述,旨在加强健康女性对三阴性乳腺癌的认识与自我保健,提示临床医生将TNBC生物学特点与流行病学特点结合进行指导预防,为研究人员对TNBC的病因学进一步的研究提供更多的理论依据。     

长春瑞滨联合紫杉醇治疗晚期乳腺癌

背景与目的：长春瑞滨（商品名诺维本、NVB）其作用阻滞微管蛋白聚合和诱导微管的解聚，而紫杉醇相反，它促进微管蛋白的聚合，阻微管正常的生理性解聚：本文观察长春瑞滨联合紫杉醇治疗晚期乳腺癌的临床疗效疗效和毒副反应方法：42例经病理学和细胞学证实的晚期乳腺癌患者应用长春瑞滨25mg/m^2，静脉滴注，第1、8d；紫杉醇175mg/m^2，静脉滴注3h，第1天；在紫杉醇静脉滴注之前12h、6h，分别口服地塞米松20mg，给药前30min肌注非那根25mg和西米替丁300mg静脉滴注。21d为一个周期，完成2～4个周期后评价疗效：结果：全组总缓解率（RR）66．7％，填中完全缓解率（CR）16．7％，初次化疗患者RR72．2％，CR27．7％；再次化疔患者RR62．1％，CR8．3％，2，4年生存率分别为40．5％（17／42）和21．4％（9／42）；中位缓解期为8个月（5～17个月），中化生存期为18个月；主要毒副反应为骨髓抑制，脱发和周围静脉炎：结论：长春瑞滨联合紫杉醇方案治疗晚期乳腺癌有很好的疗效，且毒副反心患者可耐受。     

Weekly paclitaxel in women age 65 and above with metastatic breast cancer

We evaluated therapy with weekly paclitaxel 80mg/m² in metastatic breast cancer patients age 65. There was a low incidence of serious toxicities, with similar tolerability profiles in younger and older patients. Response rates and overall survival times were comparable in the two age groups (<65 and 65). Weekly paclitaxel therapy is a reasonable option for older patients with metastatic breast cancer.     

Glucocorticoids interfere with therapeutic efficacy of paclitaxel against human breast and ovarian xenograft tumors

Paclitaxel is a widely used naturally occurring antineoplastic agent that has shown great promise in the treatment of a variety of human solid tumors, particularly for advanced breast and ovarian cancers. Recent studies in our laboratory discovered that glucocorticoids could selectively inhibit paclitaxel-induced apoptosis in a number of human solid tumor cell lines in vitro. Since glucocorticoids (such as dexamethasone) are routinely used as a premedication in the clinical application of paclitaxel to prevent hypersensitivity reactions and other adverse effects, the inhibitory effect of glucocorticoids on paclitaxel-induced apoptosis has raised a clinically relevant question as to whether the pretreatment with glucocorticoids might interfere with the therapeutic efficacy of paclitaxel. In the present study, through development of animal models bearing human breast and ovarian xenograft tumors, we evaluated the potential influence of dexamethasone on antitumor activity of paclitaxel in vivo. The results demonstrated that pretreatment of dexamethasone significantly attenuated therapeutic efficacy of paclitaxel against human breast and ovarian xenograft tumors. The inhibition rate of 20 mg paclitaxel/kg on the growth of breast and ovarian xenograft tumors was around 20-25% less when the animals were pretreated with 1 mg dexamethasone/kg. Further analyses with histological examination and TdT-mediated dUTP nick end labeling assay indicate that pretreatment with dexamethasone clearly interferes with the cytotoxic effects of paclitaxel on both morphological alterations and induction of cell death. Additionally, immunohistochemical staining of proliferation marker Ki-67 indicates that the percentage of proliferating cells in xenograft tumors with pretreatment of dexamethasone is much higher than that in the tumors treated with paclitaxel alone. Put together, the results obtained from the animal experiments show that pretreatment of xenograft tumors with dexamethasone results in significant inhibition of the therapeutic efficacy of paclitaxel in vivo. This finding may have a potential implication on the clinical practice of paclitaxel-based chemotherapy.     

三阴性乳腺癌治疗的研究进展

三阴性乳腺癌（triple negative breast cancer，TNBC）是雌激素受体(estrogen receptor，ER)、孕激素受体（progesterone receptor，PR）及人类表皮生长因子受体（human epidermal growth factor-2,HER-2）均不表达的乳腺癌。按其功能特征可归纳为5类分子分型:以DNA修复缺陷或生长因子为途径的基底细胞样三阴性乳腺癌；以上皮-间充质转化和肿瘤干细胞为特征的间质样三阴性乳腺癌；免疫调节型三阴性乳腺癌；雄激素受体过表达的管腔／分泌型三阴性乳腺癌；HER-2富集型三阴性乳腺癌。三阴性乳腺癌恶性程度高且异型性较大，其治疗困难且预后较差，内分泌治疗及靶向治疗不敏感。目前很多学者对于三阴性乳腺癌的治疗各有研究，并有临床试验证实下述治疗有效。