Expression of keratinocyte growth factor and its receptor in human breast cancer: its inhibitory role in the induction of apoptosis possibly through the overexpression of Bcl-2

Keratinocyte growth factor (KGF), a mesenchymal cell derived paracrine growth factor that regulates normal epithelial cell proliferation, appears to be an essential mediator of steroids in various reproductive organs. The present study was designed to determine the expression and role of KGF and its receptor (KGFR) in human breast carcinoma tissues by immunohistochemistry. We also compared the results with the expression of estrogen receptor alpha(ERalpha), ERbeta, the proliferative activity assessed by the labeling index (LI) for the Ki-67 antigen, apoptotic frequency assessed by terminal dUTP nick end-labeling (TUNEL) index, and the expression of Bcl-2. All of KGF-positive cases were ERalpha- positive (p<0.05), but not that of ERbeta, while all of KGFR-positive cases were ERbeta-positive (p<0.05), but not that of ERalpha. The specimens with the coexpression of KGF and KGFR significantly correlated with a lower TUNEL index (p<0.05), but not with Ki-67 LI in breast cancer tissues. Further analysis at the cellular level revealed that Bcl-2 was colocalized in KGFR-positive cells, and these cells were almost negative for TUNEL staining. Bcl-2-positive cells were also associated with ERbeta, as expected. Therefore, the results indicate that ERalpha may be involved in KGF expression, and that the coexpression of KGF and KGFR may play an inhibitory role in the induction of apoptosis possibly through the up-regulation of Bcl-2 expression in human breast cancer.     

On the possible role of mammary-derived growth hormone in human breast cancer

The incidence of breast cancer has risen worldwide, especially in countries where it used to be low, very probably as a result of economic prosperity and changes in life-style. In women, the available data have resulted in the concept of progression from normal breast development to cancer through precursor lesions sensitive to hormones and growth factors that can be produced locally in the mammary gland, acting as paracrine or autocrine stimulating agents. The local endocrine environment in the breast can be different from the situation in the circulation. In the dog, growth hormone (GH) can be produced locally in the mammary glands and its production can be stimulated by progestins. This GH probably plays a paracrine role in the progesterone-induced proliferation and differentiation of mammary epithelium. There is increasing evidence that the local mammary progestin/GH-axis is operational not only in dogs but also in human breast cancer. No data are yet available on the production of mammary-derived GH in women.     

Enhanced expression of keratinocyte growth factor and its receptor correlates with venous invasion in pancreatic cancer

Keratinocyte growth factor (KGF) and KGF receptor (KGFR) have been implicated in cancer growth as well as tissue development and repair. In this study, we examined whether KGF and KGFR have a role in human pancreatic ductal adenocarcinoma (PDAC). KGFR mRNA was expressed in eight pancreatic cancer cell lines, whereas the KGF mRNA was detected in seven of the cell lines and was absent in MIA PaCa-2 cells. KGFR and KGF immunoreactivity were localized in the cancer cells in 41.5 and 34.0% of patients, respectively. There was a significant correlation between KGFR or KGF immunoreactivity and venous invasion and a significant correlation between the presence of both markers and venous invasion, vascular endothelial growth factor (VEGF)-A expression, and poor prognosis. Exogenous KGF increased VEGF-A expression and release in MIA PaCa-2 cells, and PANC-1 cells stably transfected to overexpress KGF-exhibited increased VEGF-A expression. Moreover, short hairpin-KGFR transfection in MIA PaCa-2 cells reduced the stimulatory effect of exogenous KGF on VEGF-A expression. Short hairpin-KGF transfection in KLM-1 cells reduced VEGF-A expression in the cells. KGFR and KGF may act to promote venous invasion and tumor angiogenesis in PDAC, raising the possibility that they may serve as novel therapeutic targets in anti-angiogenic strategies in PDAC.     

siRNA抑制ErbB2基因的表达及对乳腺癌细胞生长的影响

目的:设计并构建ErbB2的小干扰RNA,检测其对ErbB2蛋白表达的干扰效果,并检测其对乳腺癌细胞ZR75-1生长的影响。方法:设计2条针对ErbB2的siRNA,并克隆到siRNA表达载体pSliencer 2.1-U6 neo上。经酶切和测序证明构建成功后,将其与pcDNA3-FLAG-ErbB2共转染于293T细胞,以及单转siRNA于乳腺癌SKBR3和ZR75-1细胞,通过Western blot分别检测siRNA对外源和内源ErbB2的干扰效果。通过结晶紫实验研究siRNA对ZR75-1生长的影响。结果:Western blot证明构建的两条ErbB2 siRNA均能有效抑制外源和内源ErbB2蛋白的表达,并抑制乳腺癌ZR75-1细胞的生长。结论:构建的siRNA能有效地抑制ErbB2蛋白的表达并抑制ZR75-1细胞的生长。     

Immunosuppressive role of transforming growth factor beta in breast cancer

Transforming growth factor beta (TGF-β) is a multifunctional cytokine, whose myriad of functions include its ability to potently suppress the immune system. Because of its ability to negatively modulate the inductive and effector phases of the immune response, TGF-β is thought to contribute to tumor progression and metastases formation. Immunosuppression by tumor-derived TGF-β is increasingly becoming recognized as an important factor in tumor progression and may, in part, explain the low response rates achieved in cancer patients undergoing immunotherapy for their disease. This review will focus on the immunosuppressive role of tumor-derived TGF-β in breast cancer. Due to the paucity of human studies, it will specifically address the actions of tumor-derived TGF-β on cells of the immune system in preclinical animal models, as well as discuss strategies to negate the deleterious effects of TGF-β in order to improve the anti-tumor immune response.     

Syk基因对乳腺癌血管内皮生长因子-C表达的调控作用

目的 研究Syk基因对乳腺癌血管内皮生长因子(VEGF)-C表达的调控机制.方法 采用免疫组织化学(EnVision法)检测乳腺癌组织中Syk、NFκB与VEGF-C的蛋白表达情况,分析三者的相关性及与淋巴转移的关系.转染pcDNA3.1(-)-Syk至乳腺癌MDA-MB-231细胞,检测对VEGF-C和NFκB表达的影响.结果 在淋巴转移组中,Syk蛋白阳性率低于非淋巴转移组,VEGF-C与NFκB阳性率在淋巴转移组高于非淋巴转移组.Syk蛋白表达与NFκB(r=-0.448,P=0.002)、VEGF-C(r=-0.620,P=0.000)蛋白表达呈负相关,VEGF-C与NFκB呈正相关(r =0.310,P=0.036).转染pcDNA3.1(-)-Syk重组质粒的乳腺癌细胞中VEGF-C的mRNA及蛋白表达水平均低于空白对照组,细胞核NFκB蛋白表达低于空白对照组(均P＜0.05).结论 Syk基因与乳腺癌转移相关,可能是通过抑制NFκB的活性而下调VEGF-C的表达,从而抑制乳腺癌的淋巴转移.     

人非小细胞肺癌中KGF mRNA的表达及意义

目的研究人非小细胞肺癌(non-small cell lung cancer,NSCLC)角化细胞生长因子(keratinocyte growth factor,KGF)mR-NA的表达,及其在NSCLC发生过程中肿瘤细胞与间质细胞间的相互作用。方法采用原位杂交和免疫组化法检测KGF mR-NA与Ki-67在50例NSCLC的表达,并与正常组织对照。结果KGF mRNA的表达除在NSCLC某些实质细胞内观察到外,主要见于NSCLC的纤维母细胞和血管平滑肌细胞胞质。肿瘤组织KGF mRNA表达的阳性率86%明显高于正常肺组织的24%(P<0·05)。有淋巴结转移者比无淋巴结转移者的表达更强,且与肺癌的分化相关,分化程度越低,KGF mRNA表达越强。在50例肺癌中Ki-67表达的分布与KGF mRNA相似。结论NSCLC存在KGF mRNA高表达。KGF可通过旁分泌、自分泌两种方式发挥作用。KGF可能与NSCLC的发生有一定的相关性。     

Estrogen receptor beta expression in invasive breast cancer

The aim of this work was to determine the extent of estrogen receptor beta (ER-beta) expression in invasive breast cancer (BrCA) and whether ER-beta expression is correlated with response to adjuvant hormonal therapy with tamoxifen (AHTT). Immunohistochemical staining (IHC) for estrogen receptor alpha (ER-alpha) and ER-beta was performed on sections of formalin-fixed and paraffin-embedded tissue from 47 unselected invasive breast carcinomas (BrCA). IHC for ER-beta was also performed on sections of BrCA from 118 women who were treated with mastectomy and AHTT. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. Of the 47 unselected BrCA, 17 (36%) were negative for ER-alpha and of these, 8 (47% of ER-alpha negative cases and 17% of all 47 patients) were ER-beta positive. Five of the 8 ER-alpha negative and ER-beta positive cases were positive for ER biochemically. There was no correlation between ER-beta positivity and overall survival in the unselected group. By contrast, in the group of women treated with AHTT, expression of ER-beta in more than 10% of cancer cells was associated with better survival (P = .0077), even in women with node-negative BrCA (P = .0069). In conclusion, our results show that a significant number of women with BrCA are positive for ER-beta only, and may be determined to be ER-negative when currently available IHC is used. ER-beta status is a significant predictor of response to AHTT in women with BrCA. Larger studies with multivariate analysis are needed to confirm these findings.     

黄芪多糖抑制人乳腺癌MCF－7细胞增殖和诱导凋亡

目的探讨中药黄芪多糖的体外抗人乳腺癌MCF．7细胞活性。方法实验分为空白对照组、黄芪多糖组和阳性对照组,黄芪多糖组MCF．7细胞给予不同浓度（2．5、5、10、20mg／L）的黄芪多糖,阳性对照组给予10gmol／L顺铂,空白对照组给予等体积培养基。48h后应用四甲基偶氮唑蓝（MTT）法测黄芪多糖对MCF-7细胞增殖抑制率,计算IC_50;吖啶橙（AO）,溴化乙啶（EB）荧光染色法测定黄芪多糖对MCF-7细胞诱导凋亡作用;应用流式细胞仪分析黄芪多糖对MCF-7细胞凋亡和细胞周期的影响。结果在给予2．5、5、10、20mg／L黄芪多糖48h后,黄芪多糖呈浓度依赖性抑制MCF．7细胞的增殖（r=0．985,P〈0．05）,抑制率分别为（4．14±2．96）％、（7．14±2．10）％、（20．13±2．33）％、（64．66±5．15）％,高于空白对照组0％,但4个不同浓度组的抑制率均低于阳性对照组（90．31±4．92）％。黄芪多糖48h的IC_50=16．83mg／L。随着黄芪多糖浓度的逐渐增高,MCF-7细胞中代表凋亡的玛瑙色逐渐增多,细胞核骤缩、核分裂,细胞形态呈现典型的凋亡特征。2．5、5、10、20mg／L黄芪多糖的凋亡率分别为（2．37±0．98）％、（6．76±1．31）％、（11．65±1．46）％、（20．75±2．68）％,高于空白对照组（1．14±1．25）％（均P〈0．05）,但均低于阳性对照组（35．09±2．88）％（均P〈0．05）。与空白对照组比较,黄芪多糖以浓度依赖性诱导MCF-7细胞凋亡（r=0．991,P〈0．05）,随浓度的增加,细胞凋亡率升高,但均低于阳性对照组。黄芪多糖随浓度的增加促使s期细胞比例逐渐升高,但低于空白和阳性对照组（均P〈0．05）,使处于G_0-G_1期细胞的比例逐渐减少,仍高于空白和阳性对照组（均P〈0．05）。结论黄芪多糖抑制人乳腺癌MCF-7细胞增殖并诱导其凋亡,使MCF-7细胞生长增殖停滞在S期?     

Altered expression of prolactin receptor-associated signaling proteins in human breast carcinoma.

Prolactin receptor signaling can modulate proliferation, survival, motility, angiogenesis, and differentiation in breast cancer. Increased serum prolactin is associated with a significantly increased risk of breast cancer in post-menopausal women. The purpose of this study was to examine the expression of prolactin receptor-associated signaling proteins in breast cancer vs benign breast tissue. Breast tissue microarrays representing 40 cases of benign and malignant pathologies were obtained from the Cooperative Human Tissue Network. Standard immunohistochemistry for prolactin and prolactin receptor-associated proteins was performed. Both positive regulators (c-Myb, Nek3, Vav2) and negative regulators (PIAS3, SIRP) of prolactin receptor signaling were examined. Virtual slides were created from the stained breast tissue microarrays. Labels were scored by region of interest and labeling indices incorporating percent target labeled and label intensity were created. Quantitative determinations of labels were made using the Clarient image system. The unpaired t-test was used to compare labels from benign and malignant tissues. Visual scoring data showed upregulation of Nek3 (P=0.000377), PIAS3 (P=0.000257), and prolactin (P=0.002576) in breast cancer vs normal/hyperplastic epithelium. c-Myb showed a trend toward upregulation, but this did not achieve statistical significance (P=0.107374). SIRP (P=0.002060) was downregulated. Vav2 showed a trend toward downregulation (P=0.107456), but this did not achieve statistical significance. Clarient analysis corroborated upregulation in cancer of Nek3 (P=0.000013), PIAS3 (P=0.000067), and prolactin (P=0.017569). In conclusion, regulators of prolactin receptor signaling show heterogeneity in their expression in benign vs malignant breast tissue. Since these species are known to regulate prolactin-mediated actions, these results suggest multiple targets for modulating prolactin receptor-mediated growth and differentiation in breast cancer.     

Recombinant human leptin induces growth inhibition and apoptosis in human gastric cancer MGC-803 cells

The aim of this study is to investigate the effect of recombinant human leptin (rhLep) on the proliferation of human gastric cancer MGC-803 cells and its underlying mechanisms. RT-PCR was performed to identify the expression of leptin receptor (Ob-R). Cell proliferation was measured with MTT assay. DNA content and cell cycle were analyzed by flow cytometry. Apoptosis was assessed by DNA ladder assay and flow cytometry analysis using Annexin V-FITC/PI double staining. Underlying mechanisms of rhLep-induced apoptosis were evaluated by the activities of caspase-3, -8, -9, and cytochrome c release from mitochondria. Moreover, the phosphorylation of STAT3 in MGC-803 cells upon rhLep administration was detected by Western blot analysis. Our results demonstrated that two leptin receptors (Ob-Ra and Ob-Rb) were expressed in MGC-803 cells. rhLep diminished the proliferation rate of MGC-803 cells in a time- and concentration-dependent manner and induced MGC-803 cell apoptosis involving in the activation of caspase-8 and caspase-3 but not caspase-9. In addition, rhLep failed to induce cytochrome c release from mitochondria and had no effect on the activation of STAT3 in MGC-803 cells. Therefore, from these results, we concluded that rhLep significantly inhibited cell proliferation via G0/G1 phase cell cycle arrest and induced apoptosis through the extrinsic apoptotic pathway in human gastric cancer MGC-803 cells.     

Clinical value of epidermal growth factor receptor expression in primary breast cancer

EGFR expression in primary breast cancer has been extensively investigated for its prognostic and predictive value. However overall there is no consensus on its potential to guide such prognostication. This is largely because of the great heterogeneity in study designs and methods used to assay the EGFR protein. The impetus to standardize such studies is much needed as there are now several tyrosine kinase inhibitors directed against the EGF receptor and phase II trials are showing significant promise.     

维甲酸对高氧暴露新生大鼠肺组织角化细胞生长因子及其受体表达的影响

目的: 探讨高氧暴露新生大鼠肺组织结构的变化和角化细胞生长因子(KGF)及其受体(KGFR)的表达情况及维甲酸(RA)对其的影响。方法: 将出生24 h内SD大鼠90只随机分为3组,Ⅰ组:空气+生理盐水(NS);Ⅱ组:高氧+NS;Ⅲ组:高氧+RA。Ⅱ、Ⅲ组持续暴露于85% O₂中,Ⅰ组置于空气中;Ⅲ组每天腹腔注射RA,Ⅰ、Ⅱ组每天腹腔注射NS。分别于生后3、7、14 d取肺标本,用HE染色法观察肺组织结构变化及辐射状肺泡计数(RAC);RT-PCR检测KGF和KGFR mRNA表达强度和免疫组织化学法检测KGF蛋白表达水平。结果: (1)生后第14 d,Ⅱ、Ⅲ组较Ⅰ组RAC值显著减少(P<0.05),但Ⅲ组较Ⅱ组明显增高(P<0.05)。(2)与Ⅰ组相比,Ⅱ组3 d时,KGF mRNA表达明显增强(P<0.05);其后开始下降,7 d仍高于Ⅰ组(P<0.05);14 d时较Ⅰ组有所降低(P<0.05);Ⅲ组各时点表达量均高于同期Ⅱ组(P<0.05)。3 d时,各组KGFR mRNA表达量无明显差异;7 d、14 d时,Ⅱ、Ⅲ组表达量明显低于Ⅰ组(均P<0.05),且Ⅱ组和Ⅲ组之间无显著差异(P>0.05)。(3)KGF阳性细胞主要分布在部分肺泡壁及肺泡周围血管内皮细胞和间质细胞。KGF蛋白表达强度与其mRNA表达变化相似。结论: RA可促进肺组织KGF表达,改善高氧所致肺发育受阻。对未成熟肺高氧损伤有一定的保护作用。     

Vascular endothelial growth factor expression promotes the growth of breast cancer brain metastases in nude mice

Patients with breast cancer brain metastases cannot be cured and have a poor prognosis, with a median survival time of six months after diagnosis, despite developments in diagnostic and therapeutic modalities. In large part the progress in understanding the biology of breast cancer brain metastasis has been limited by the lack of suitable cell lines and experimental models. The objective of this study was to develop a reliable experimental model to study the pathogenesis of breast cancer brain metastases, using intra-internal carotid artery injection of breast cancer cells into nude mice. Brain metastasis-selected variant cells were recovered after three cycles of injection into the internal carotid artery of nude mice and harvest of brain metastases, resulting in variants termed MDA-231 BR1, -BR2 and -BR3. The metastasis-selected cells had increased potential for experimental brain metastasis and mice injected with these cells had significantly shorter mean survival than mice injected with the original cell line. Brain metastatic lesions of the selected variants contained significantly more CD31-positive blood vessels than metastases of the non-selected cell line. The variants selected from brain metastases released significantly more VEGF-A and IL-8 into culture supernatants than the original cell line, and more VEGF-A RNA when cultured in normoxic conditions. Mice injected with MDA-231 BR3 into the carotid artery were treated with the VEGF-receptor tyrosine kinase inhibitor PTK787/Z 222584. Oral administration of the inhibitor resulted in a significant decrease in brain tumor burden, reduced CD31-positive vessels in the brain lesions and incidence of PCNA positive tumor cells, and increased apoptosis in the tumor, as measured by TUNEL labeling. We conclude that elevated VEGF expression contributes to the ability of breast cancer cells to form brain metastases. Targeting endothelial cells with a VEGF-receptor specific tyrosine kinase inhibitor reduced angiogenesis and restricted the growth of the brain metastases.     

Expression of keratinocyte growth factor/fibroblast growth factor-7 and its receptor in human lung cancer: correlation with tumour proliferative activity and patient prognosis

Keratinocyte growth factor (KGF)/fibroblast growth factor-7 (FGF-7), a mesenchymal cell-derived paracrine growth factor that specifically stimulates epithelial cell proliferation, has been implicated in the repair of lung tissue. The present study was designed to determine the expression and role of KGF and its receptor (KGFR) in human lung cancer tissues, particularly in relation to cancer cell kinetics and prognosis. Thirty-one adenocarcinomas and 30 squamous cell carcinomas, and ten normal lung tissues as a control, were examined. The expression of KGF and KGFR proteins was examined using rabbit polyclonal anti-human KGF and anti-human KGFR antisera raised in the authors' laboratories against synthetic peptides corresponding to parts of human KGF KGFR, respectively. Their specificity was confirmed in lung tumour tissues by western blotting various controls. Proliferative activity was assessed by determining the labelling index (LI) for Ki-67 antigen. Immunohistochemistry revealed that tissue co-expression of KGF KGFR correlated significantly with higher differentiation grades in squamous cell carcinoma. Conversely, in adenocarcinoma, co-expression correlated with lower differentiation grades high Ki-67 LI, was significantly associated with lymph node metastasis shorter 5-year survival. Therefore, the results indicate that co-expression of KGF KGFR correlates significantly with poor prognosis in adenocarcinoma, but not in squamous cell carcinoma, of the lung.     

表皮生长因子促进电压门控钠通道Nav1.5表达及人乳腺癌细胞的侵袭

目的 探讨表皮生长因子(EGF)是否调节乳腺癌MDA-MB-231细胞电压门控钠通道(VGSC)Nav1.5亚型基因的表达及其可能的信号分子传导途径.方法 用Matrigel侵袭、免疫荧光定位、实时荧光定量RT.PCR(RFQ-PCR)和Western blot等方法,分别检测或探讨EGFR和Nav1.5蛋白在细胞中的表达和定位、EGF和Nav1.5对细胞侵袭的作用、EGF对Nav1.5 mRNA和蛋白水平的影响以及P13K在EGF增加侵袭中的作用.结果 MDA-MB-231细胞高表达EGF受体和Nav1.5蛋白,EGF增加细胞的侵袭达51.0%±2.6%,VGSC抑制剂Tetrodotoxin(TTX)10 μmol/L阻滞EGF诱导的细胞侵袭(P＜0.05);EGF增加Nav1.5 mRNA水平为(128±4)倍(P＜0.05),Nav1.5蛋白水平有39%±4%上升(P＜0.05).P13K抑制剂Wortmannin抑制EGF诱导的Nav1.5 mRNA和蛋白水平的增加,亦抑制EGF诱导的细胞侵袭.结论 EGF上调乳腺癌MDA-MB-231细胞VGSC Nav1.5亚型mRNA和蛋白的表达,促使乳腺癌细胞的侵袭,P13K参与EGF诱导的Nav1.5的表达和细胞的侵袭.