曲妥珠单抗对HER-2胞外域水平不同的肿瘤细胞系的影响

目的探讨曲妥珠单抗(trastuzumab)对细胞膜p185人表皮生长因子受体2(HER-2)强阳性表达,以及HER-2胞外域(ECD)水平不同的肿瘤细胞系SKBR3和SKOV3细胞的生长、克隆形成及细胞内HER-2蛋白水平的影响。方法SKBR3和SKOV3细胞经曲妥珠单抗处理后,统计细胞数目及克隆形成率。双抗夹心ELISA法检测细胞培养上清中HER-2 ECD水平,Western blot检测细胞HER-2蛋白水平。结果高HER-2 ECD水平的SKBR3细胞生长及克隆形成率明显被曲妥珠单抗抑制,在相对分子质量为90 000和40 000左右分别有1条未知磷酸化蛋白明显降低或基本消失,而细胞生长及克隆形成率未受影响的SKOV3细胞中此蛋白无明显变化。SKBR3和SKOV3细胞中p185 HER-2蛋白、磷酸化-p185蛋白、磷酸化-p95蛋白水平并未见明显降低。曲妥珠单抗不仅与SKOV3细胞培养上清中的HER-2 ECD反应,也与p68/ECDⅢa蛋白反应。经曲妥珠单抗处理后,SKBR3细胞HER-2 ECD水平明显降低,但将曲妥珠单抗处理前、后的细胞数目调整到基本一致时,HER-2 ECD水平未发生明显变化。结论曲妥珠单抗抑制肿瘤细胞生长可能与阻止相对分子质量为90 000和40 000左右的未知磷酸化蛋白表达有关;p68/ECDⅢa蛋白也可能存在曲妥珠单抗识别位点;HER-2 ECD水平降低可能与SKBR3细胞数目减少有关。     

Trastuzumab prolongs overall survival in patients with brain metastases from Her2 positive breast cancer

Background: Brain metastases are frequently encountered in Her2 positive advanced breast cancer. It is still not clear, if trastuzumab treatment should be continued following their diagnosis. In this analysis we evaluated if trastuzumab was able to influence time to in-brain progression (TTP) and overall survival (OS). For this reason, we compared patients who continued on trastuzumab with a historical control group. Patients and Methods: Seventeen Her2 positive patients receiving whole brain radiotherapy for brain metastases and continuing on trastuzumab were identified. As historical control group, thirty-six patients treated before 2002 were identified from a breast cancer database. We performed a multivariate analysis (Cox regression) to explore which factors were potentially able to significantly influence TTP and OS. Results: Median TTP was 6 months, range 1–33+ months. Median OS was 7 months, range 1–38 months. Seventeen patients received trastuzumab after WBRT. Factors associated with prolonged TTP were KPS (p = 0.001), and intensified local treatment (p = 0.004). A trend towards longer TTP was observed in patients treated with trastuzumab (p = 0.068). OS was significantly influenced by KPS (p < 0.001), and continued antibody therapy (p = 0.001). Conclusion: Two parameters were significantly associated with prolonged OS: KPS and trastuzumab. While there was a trend towards prolonged TTP in patients with trastuzumab treatment after WBRT, this did not reach statistical significance. It appears therefore reasonable to suggest continuation of antibody therapy in patients with good performance status despite disease spreading to the brain. Concerning activity of trastuzumab in brain metastases themselves, no final conclusion is possible.     

Neuregulin-1 beta attenuates doxorubicin-induced alterations of excitation-contraction coupling and reduces oxidative stress in adult rat cardiomyocytes

Treatment of metastatic breast cancer with doxorubicin (Doxo) in combination with trastuzumab, an antibody targeting the ErbB2 receptor, results in an increased incidence of heart failure. Doxo therapy induces reactive oxygen species (ROS) and alterations of calcium homeostasis. Therefore, we hypothesized that neuregulin-1 beta (NRG), a ligand of the cardiac ErbB receptors, reduces Doxo-induced alterations of EC coupling by triggering antioxidant mechanisms. Adult rat ventricular cardiomyocytes (ARVM) were isolated and treated for 18-48 h. SERCA protein was analyzed by Western blot, EC coupling parameters by fura-2 and video edge detection, gene expression by RT-PCR, and ROS by DCF-fluorescence microscopy. At clinically relevant doses Doxo reduced cardiomyocytes contractility, SERCA protein and SR calcium content. NRG, similarly as the antioxidant N-acetylcystein (NAC), did not affect EC coupling alone, but protected against Doxo-induced damage. NRG and Doxo showed an opposite modulation of glutathione reductase gene expression. NRG, similarly as NAC, reduced peroxide- or Doxo-induced oxidative stress. Specific inhibitors showed, that the antioxidant action of NRG depended on signaling via the ErbB2 receptor and on the Akt- and not on the MAPK-pathway. Therefore, NRG attenuates Doxo-induced alterations of EC coupling and reduces oxidative stress in ARVM. Inhibition of the ErbB2/NRG signaling pathway by trastuzumab in patients concomitantly treated with Doxo might prevent beneficial effects of NRG in the myocardium.     

Genetic variation of human neutrophil Fcγ receptors and SIRPα in antibody‐dependent cellular cytotoxicity towards cancer cells

The efficacy of cancer therapeutic antibodies varies considerably among patients. Anti‐cancer antibodies act through different mechanisms, including antibody‐dependent cellular cytotoxicity (ADCC) triggered via Fcγ receptors (FcγR). This phagocyte ADCC can be promoted by interference with CD47‐SIRPα interactions, but the magnitude of this enhancement also varies among individuals. Both FcγR and SIRPα display considerable genetic variation, and we investigated whether this explains some of the variability in ADCC. Because of linkage disequilibrium between FcγR variants the interpretation of previous reports suggesting a potential link between FcγR polymorphisms and ADCC has been troublesome. We performed an integrated genetic analysis that enables stratification. ADCC by activated human neutrophils towards Trastuzumab‐coated breast cancer cells was predominantly dependent on FcγRIIa. Neutrophils from individuals with the FcγRIIa‐131H polymorphic variant displayed significantly higher killing capacity relative to those with FcγRIIa‐131R. Furthermore, ADCC was consistently enhanced by targeting CD47‐SIRPα interactions, and there were no significant functional differences between the two most prevalent SIRPα polymorphic variants. Thus, neutrophil ADCC capacity is directly related to the FcγRIIa polymorphism, and targeting CD47‐SIRPα interactions enhances ADCC independently of FcγR and SIRPα genotype, thereby further suggesting that CD47‐SIRPα interference might be a generic strategy for potentiating the efficacy of antibody therapy in cancer.     

Tyrosine kinase inhibitors and human epidermal growth factor receptor-2 positive breast cancer

The body of evidence investigating human epidermal growth factor receptor-2 (HER2) directed therapy in patients with breast cancer (BC) has been growing within the last decade. Recently, the use of tyrosine kinase inhibitors (TKIs) has been of particular interest in the treatment of human malignancies. This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.     

Patients’ satisfaction in early breast cancer treatment: Change in treatment over time and impact of HER2-targeted therapy

Although breast cancer remains a major cause of cancer death, its related death rate has dropped in the last years through early tumor detection and better available treatments. With the development of innovative techniques and new molecules as well as new routes of administration, local treatment and adjuvant therapy of early breast cancer have evolved, from mutilating, time-consuming and/or painful procedures to breast-conservative ones, sparing healthy tissues, reducing the total dose of treatment and the treatment time which in turn reduce the occurrence and severity of toxicity. In parallel with these improvements leading to an increase in survival rate, patients’ health-related quality of life has become a major concern. This review aims at describing the evolution of early breast cancer treatment, and its impact on patients’ quality of life, convenience, and satisfaction, including a special insight into emerging human epidermal growth factor receptor 2 (HER2)-targeted therapy.     

嗜酸性粒细胞作为乳腺癌病人曲妥珠单抗相关输注反应的预测指标价值分析

目的探讨嗜酸性粒细胞作为乳腺癌病人曲妥珠单抗相关输注反应的预测价值。方法回顾性分析黄山市人民医院 2019年 1月至 2021年 12月 174例连续住院女性病人，均接受初始 8 mg/kg曲妥珠单抗治疗量，评估输注反应(IRs)发生情况。结果 136例病人符合纳入研究条件，在 27.9%(38/136)病人中观察到 IRs，多因素 logistic分析结果显示体质量指数 ≥24 kg/m2和嗜酸性粒细胞百分比 ≤2%是病人发生 IRs的危险因素，嗜酸性粒细胞百分比预测 IRs的曲线下面积为 0.75［95%CI:(0.65，0.85)］，当截断值为 2.05时，灵敏度和特异度分别为 86.4%和 54.5%；联合 BMI后预测 IRs的曲线下面积提高至 0.80(0.72，0.88)，其对应的灵敏度和特异度分别为 78.8%和 72.8%。结论低嗜酸性粒细胞百分比可作为乳腺癌病人曲妥珠单抗相关输注反应的预测因素。