Antisense Bcl-2 and HER-2 oligonucleotide treatment of breast cancer cells enhances their sensitivity to anticancer drugs

Overexpression of the HER-2 correlates with drug-resistance and a poor prognosis in breast cancer, however the mechanism(s) of HER-2-mediated drug-resistance are unknown. We examined the effects of antisense Bcl-2 and HER-2 oligonucleotides (ODN) to assess the mechanism(s) through which down-regulation of Bcl-2 and HER-2 enhances drug-sensitivity. Using two human breast cancer cell lines, MDA-MB-231 and BT-474, the antitumor effects of a combination of antisense ODN and anticancer drugs, including mitomycin C (MMC), adriamycin (ADM), paclitaxel (TXL), and docetaxel (TXT) was evaluated. The expression of Bcl-2 protein was suppressed by treatment with antisense Bcl-2 ODN in a dose-dependent manner. An enhanced drug-sensitivity to MMC and TXL upon pretreatment with antisense Bcl-2 ODN was observed, with the IC50 values increasing 1.9- and 2.0-fold, respectively. Treatment of BT-474 cells with antisense HER-2 at 1.0 micro M suppressed HER-2 overexpression by 60.5%. Pretreatment with antisense HER-2 ODN increased the sensitivity of these cells to ADM and TXL 20.8- and 10.8-fold, respectively. In vivo experiments using a combination of antisense HER-2 and TXL showed the similar enhancement of antitumor effect of TXL as compared to that of antisense HER-2 or TXL alone (p=0.068). Enhancement of drug-sensitivity was associated with the induction of apoptosis. Of interest, treatment with antisense HER-2 ODN also suppressed the expression of Bcl-2 and pAkt. These results indicate that down-regulation of Bcl-2 and HER-2 increased drug-sensitivity by modulating drug-induced apoptotic pathways in breast cancer cells, and that antisense ODN therapy, targeting Bcl-2 and HER-2 may be a useful strategy to enhance drug-sensitivity.     

6周期AT新辅助化疗治疗乳腺癌临床疗效及其影响因素的分析

目的:探讨6周期AT方案(蒽环类联合紫杉类)新辅助化疗在乳腺癌治疗中的疗效及影响pCR 的因素.方法:回顾性分析159例顺利完成6周期AT方案患者的临床病理资料,对比治疗前后病理变化,评价其临床疗效及不良反应,并探究影响新辅助化疗达到pCR的因素.结果:159例完成6周期AT方案新辅助化疗的乳腺癌患者占同期进行新辅助化疗52.3%,总pCR为30.8%,降期率为76.1%.单因素及Logistic回归分析发现,肿瘤大小,组织学分级,ER、PR状态、HER-2表达、分子分型以及化疗的早期反应是影响pCR的重要因素,其中肿瘤≤3 cm、ER缺失、HER-2扩增、超声评价化疗早期反应阳性患者更容易达到pCR.结论:乳腺癌6周期AT方案新辅助化疗pCR率较高,超声评价的早期反应能够预测pCR,肿瘤大小以及肿瘤分子分型是影响pCR的重要因素,临床实践中需综合考虑影响因素,从而决定手术的最佳时机.     

Human epidermal growth factor receptor 2 (HER2) in gastric cancer: a new therapeutic target

Surgery is the only curative therapy for gastric cancer. In the metastatic setting the objective of treatment is to manage symptoms, improve quality of life and prolong survival, but current treatment options have limited efficacy and some of them exhibit unfavourable toxicity profiles. Fluoropyrimidine, taxanes and platinum-based regimens are used most frequently and offer a response rate of 30-50% with a median overall survival of =1 year. These discouraging data support the need for new therapeutic strategies based on targeted drugs. Trastuzumab, a monoclonal antibody against HER2, has shown survival benefits when given with chemotherapy in all setting of HER2-positive breast cancer patients. The ToGA trial, the first study evaluating the efficacy and safety of adding trastuzumab to chemotherapy in HER-2 positive advanced gastric cancer, showed a significant superiority of combination over chemotherapy alone. Based on these results trastuzumab combined with a cisplatin and fluoropyrimidine regimen appear the new reference treatment for HER-2 positive metastatic gastric cancer.     

Advances in first-line treatment for patients with HER-2+ metastatic breast cancer

Background.

The prognosis for breast cancer patients overexpressing human epidermal growth factor receptor (HER)-2 has changed with anti–HER-2–targeted therapy. Although anti–HER-2 therapy with trastuzumab and chemotherapy is the standard first-line treatment, the best therapeutic regimen has yet to be defined, and new strategies are evolving.

Methods.

A literature review of well-established and recently published trials, reviews, and ongoing clinical trials addressing first-line treatment for HER-2⁺ metastatic breast cancer patients was performed.

Results.

Taxanes are the agents most commonly used in combination with trastuzumab, but other chemotherapy drugs, such as anthracyclines, vinorelbine, and gemcitabine and triple-combination therapies including platinum compounds, capecitabine, and taxanes have been studied. The combination of aromatase inhibitors with anti–HER-2 therapies is a new therapeutic option for some patients who coexpress HER-2 and hormone receptors, although its activity observed in randomized clinical trials seems to be inferior to that of chemotherapy plus anti–HER-2 therapies. In addition, new anti–HER-2 therapies have shown activity in HER-2⁺ tumors, both alone and in combination with trastuzumab.

Conclusions.

Trastuzumab plus chemotherapy is the current standard of care for the upfront treatment of HER-2⁺ breast cancer patients, though other anti–HER-2–targeting agents may appear as new standards in the upcoming years.     

Effect of cisplatin on skin metastasis in breast cancer patients.

BACKGROUND: Metastatic breast cancer is a common clinical entity, and its treatment is still a major clinical problem in modern oncology. Both cisplatin (CDDP) and 5-fluorouracil (5-FU) are effective agents. PATIENTS AND METHODS: In this retrospective study, the therapeutic efficacy and tolerability of CDDP and continuous infusion of 5-FU were evaluated in patients with pretreated metastatic breast cancer. 16 patients were surveyed. All of them were pretreated with anthracyclines in an adjuvant and/or therapeutic setting. Eight of them also received taxanes after the failure of anthracyclines. CDDP at 80 mg/m(2) for 1 day and 5-FU at 1,000 mg/m(2) as a continuous 24-hour infusion for 5 consecutive days were administrated every 3 weeks. RESULTS: 13 patients were included in response analysis. Because of severe toxicity, chemotherapy protocols of 3 patients were stopped after the first cycle. The objective response rate (partial response) was 46%. No complete response was observed. The median response duration was 5 (3.5-7) months in the response group. Favorable objective responses were observed more frequently in cases with skin metastasis. Five out of 6 patients who attained partial remission had skin metastasis. Response rates were similar in patients pretreated with taxanes and in those not pretreated with taxanes (75 vs. 80%). The most serious toxicity was myelosuppression (25%). CONCLUSIONS: Although this study is based on only a limited number of patients, the combination of CDDP and 5-FU can be recommended in patients refractory to both anthracyclines and taxanes and especially in cases of skin metastasis with a good performance status.     

HER-2/neu positive breast cancer: how to prescribe adjuvant trastuzumab (Herceptin)?

One of the most recent advances in the management of Her-2/neu positive breast cancer is the validation of a targeted therapy from bench to the clinic, particularly towards the adjuvant setting. The recommended dose of trastuzumab (Herceptin), a humanized monoclonal antibody targeting the HER-2 antigen, has been determined in phase I studies. In the metastatic patients two randomised trials have demonstrated its efficacy when associated to taxanes. In less than 10 years, trastuzumab became the standard of care in the adjuvant treatment of HER-2/neu positive breast cancer. In this setting, two combinations regimen with chemotherapy (concomitant or sequential) have been recently published. The concomitant schedule has been used in three studies (North American Group, BCIRG, FinHer), whereas in the Hera trial trastuzumab was started after the end of neo-adjuvant and adjuvant chemotherapy. In this article, the advantages and uncertainties on efficacy and toxicities of the trastuzumab administration modalities, associated or not to chemotherapy and radiation therapy, are discussed.     

Randomized phase II study of weekly docetaxel plus trastuzumab versus weekly paclitaxel plus trastuzumab in patients with previously untreated advanced nonsmall cell lung carcinoma

BACKGROUND: Trastuzumab is a monoclonal antibody directed against the human epidermal growth factor receptor-2 (HER-2). Nonsmall cell lung carcinoma (NSCLC) overexpresses HER-2 protein in approximately 20% of cases. In the current study, the authors combined trastuzumab with weekly taxanes in an attempt to improve outcomes over standard chemotherapy in patients with advanced NSCLC. METHODS: The primary objective was to determine whether docetaxel plus trastuzumab or paclitaxel plus trastuzumab was the superior regimen based on response and toxicity, and to determine whether either regimen was appropriate for further testing in a randomized Phase III trial. After stratification based on the results of HER-2 immunohistochemistry, chemotherapy-naive patients were randomized to receive trastuzumab plus docetaxel or trastuzumab plus paclitaxel. The study was designed so patients with or without HER-2 overexpression would be distributed equally between the study arms. RESULTS: Immunohistochemistry for HER-2 protein expression was attempted for 182 pathologic samples from 169 patients. Twenty-eight of the 179 evaluable samples (16%) revealed 2+ or 3+ staining. The objective response rate was 23% (7 of 30 patients) in the patients treated with docetaxel plus trastuzumab and 32% (11 of 34 patients) in the patients treated with paclitaxel plus trastuzumab (P=0.76, Wilcoxon test). No difference was noted in the median survival (16 mos vs. 14 mos) or 1-year survival (57% vs. 55%) (P=0.998). Toxicities were mild in both treatment arms. No difference with regard to response rates or survival was noted between HER-2-positive (2+ or 3+) and HER-2-negative (0-1+) patients. CONCLUSIONS: The expression of HER-2 protein in patients with advanced NSCLC in this study was found to be similar to that reported in previous series. The response rates and toxicities for patients treated with docetaxel and trasuzumab or paclitaxel and trasuzumab were not significantly different, though survival in both arms was better than expected. HER-2 expression status did not appear to affect outcomes for this uniform group of patients who were treated in a comparable fashion. Because of the infrequency of HER-2 overexpression, and the absence of improved outcomes in patients with NSCLC who were treated with trastuzumab plus chemotherapy in other studies, neither regimen tested will be advanced to a Phase III trial.     

Marked response to single agent trastuzumab in a patient with metastatic HER-2 gene amplified rectal cancer

Overexpression or HER-2 gene amplification occurs in approximately 25% of invasive breast cancers and predicts response to the targeting therapeutic antibody trastuzumab (1). In this report, trastuzumab was used in the treatment of a patient with metastatic colorectal cancer harboring HER-2 gene amplification and overexpression. There was a marked radiographic response to the trastuzumab. If a larger series confirms the efficacy of trastuzumab use in patients with colorectal cancers with HER-2 gene amplification, trastuzumab could help improve the outlook for patients with this unusual colorectal cancer variant.     

Pharmacological breast cancer therapy (review)

Breast cancer ranks as the second most common cause of cancer death among women in the United States. Anticancer agents are an important component of breast cancer therapy. Drugs frequently used to treat breast cancer include methotrexate, 5-fluorouracil (5-FU), cyclophosphamide, anthracyclines, taxanes, trastuzumab, tamoxifen, and aromatase inhibitors. These agents inhibit breast cancer progression by a variety of different mechanisms. This review describes each of these drugs and the varying effects each of them have upon breast cancer cells.     

Drug treatments for adjuvant chemotherapy in breast cancer: recent trials and future directions

Adjuvant chemotherapy with anthracycline-based regimens has been proven to decrease the risk of relapse and cancer-related mortality in women with early-stage breast cancer. The taxanes, paclitaxel and docetaxel, have been incorporated into several adjuvant chemotherapy regimens in recent studies. Some of these trials have matured and demonstrated a definitive benefit with the use of taxanes. The available studies reveal that the addition of a taxane after an anthracycline or the substitution of a taxane into a three-drug regimen, such as docetaxel, doxorubicin and cyclophosphamide, clearly demonstrate a benefit for taxanes in the adjuvant treatment of breast cancer. The toxicities of the taxanes are generally acceptable. Targeted therapy, such as with trastuzumab, has demonstrated a large benefit that previously has never been seen in adjuvant chemotherapy trials, and thus, should now be part of the standard in the treatment of HER-2/neu positive breast cancer. Newer agents are on the horizon.     

Cardiac toxicity with anti-HER-2 therapies-what have we learned so far?

Trastuzumab, a monoclonal antibody that blocks HER-2 receptor, improves the survival of women with HER-2-positive early and advanced breast cancer when given with chemotherapy. Lapatinib, a dual tyrosine kinase inhibitor of EGFR and HER-2, is approved for the treatment of metastatic breast cancer patients after failure of prior anthracycline, taxanes and trastuzumab therapies in combination with capecitabine. Importantly, cardiac toxicity, manifested as symptomatic congestive heart failure or asymptomatic left ventricular ejection fraction decline, has been reported in some of the patients receiving these novel anti-HER-2 therapies, particularly when these drugs are used following anthracyclines, whose cardiotoxic potential has been recognized for decades. This review will focus on the incidence, natural history, underlying mechanisms, management, and areas of uncertainty regarding trastuzumab-and lapatinib-induced cardiotoxicity.     

Breast cancer: achievements in adjuvant systemic therapies in the pre-genomic era

In recent decades, the use of adjuvant systemic therapies for early breast cancer has increased extensively and has most likely contributed to the decline in breast cancer mortality observed in the U.S. and in some European countries. The last few years have witnessed accelerated progress in the treatment of early breast cancer, with the introduction of taxanes and aromatase inhibitors and, most impressively, trastuzumab to the adjuvant portfolio. When compared with anthracycline-based regimens, the addition of taxanes to treatments for patients with node-positive breast cancer has shown benefits in disease-free survival and, in some trials, in overall survival; however, these drugs are not yet universally accepted as standard treatment. Significant improvements in endocrine therapy in both pre- and postmenopausal patients with endocrine-responsive disease have been made. In the postmenopausal setting, aromatase inhibitors have shown superiority over tamoxifen in a direct comparison upfront or when given in sequence after 2-5 years of tamoxifen, but the optimal modality of administration remains unclear. For premenopausal women, ovarian function suppression with luteinizing hormone-releasing hormone analogues combined with tamoxifen has generated similar results to cyclophosphamide, methotrexate, 5-fluorouracil (CMF)-based regimens. Recently, trastuzumab has had a dramatic impact on the evolution of human epidermal growth factor receptor 2 (HER-2)-positive early breast cancer treated with standard adjuvant modalities; specifically, relapses, including distant relapses, have been halved. In this review, we summarize these main achievements, discuss the currently available adjuvant treatment options for breast cancer patients, and emphasize the need for more efficient translational research to improve individual treatment tailoring.     

Clinical development of S-1 (TS-1) for advanced gastric cancer

The 5-FU plus cisplatin containing regimen like FP, ECF and DCF, is considered to be the most effective treatment for advanced gastric cancer in the United States, Europe, and Korea. In Japan, oral fluoropyrimidine S-1 (TS-1) is currently considered to be the first candidate as the standard drug for advanced gastric cancer. S-1 based combination therapies with other promising drugs like cisplatin, irinotecan and taxanes, are expected to yield good results. Above all, S-1+CDDP therapy showed a high efficacy and expected to be a standard therapy for advanced gastric cancer. Two large phase III studies, JCOG 9912 5-FU vs S-1 vs CPT-11 +CDDP and S-1 vs S-1+CDDP, are now on going to establish an acceptable frontline standard for patients with AGC. We therefore need to develop new agents and combination chemotherapy regimens to achieve a greater survival benefit in AGC.     

Enhancement of antitumor effect by intratumoral administration of bax gene in combination with anticancer drugs in gastric cancer

Proapototic gene is an important target to enhance the chemotherapeutic effect in cancer cells. Based on in vitro study showing that the introduction of bax gene enhanced the sensitivity to anticancer drugs, we examined whether the intratumoral administration of bax gene could enhance the anti-tumor effect in combination with anticancer drugs in gastric cancer. The human gastric cancer cell line, MKN45 was transplanted into nude mice, and the intratumoral administration of bax gene was performed using the bax cDNA plasmid complexed with a cationic lipopolyamine. The enhancement of antitumor effect was examined in the combination with 5-fluorouracil (5-FU) and cisplatin (CDDP). The anticancer drugs were administered intraperitoneally with one third of LD50 four times at 4-day intervals, and the antitumor effect was assessed by the NCI protocol. The expression of bax gene was analyzed by RT-PCR and the apoptotic cell death was assessed by TUNEL method. The intratumoral administration of bax gene alone showed slight anti-tumor effect as compared to that of control tumor injected with vector alone. The antitumor effect of 5-FU and CDDP was significantly enhanced in the combination with intra-tumoral administration of bax gene as compared to that of CDDP and 5-FU alone (p<0.05, Student's t-test). The enhancement of antitumor effect was associated with the constitutive overexpression of bax gene and with the induction of apoptosis in the tumor treated with anticancer drug and bax gene. These results indicate that the combination therapy of intratumoral administration of bax gene complexed with a cationic lipopolyamine and anticancer drugs may provide us a new strategy for cancer chemotherapy to enhance its therapeutic efficacy in gastric cancer as termed with gene-chemotherapy.     

Selective inhibition of ADAM metalloproteases blocks HER-2 extracellular domain (ECD) cleavage and potentiates the anti-tumor effects of trastuzumab

The HER-2 receptor tyrosine kinase is an important regulator of cell proliferation and survival, and it is a clinically validated target of therapeutic intervention for HER-2 positive breast cancer patients. Its extracellular domain (ECD) is frequently cleaved by protease(s) in HER-2 overexpressing breast cancer patients, rendering the remaining membrane-bound portion (p95) a constitutively activated kinase. The presence of both serum ECD and cellular p95 protein has been linked to poor clinical outcome as well as reduced effectiveness of some therapeutic treatments. We have identified a series of potent, selective small molecule inhibitors of ADAM proteases, exemplified here by INCB003619, and demonstrate that these inhibitors effectively block HER-2 cleavage in HER-2 overexpressing human breast cancer cell lines. Intriguingly, when used in combination, INCB003619 dramatically enhances the antiproliferative activity of suboptimal doses of the anti-HER-2 antibody, trastuzumab, in HER-2 overexpressing/shedding breast cancer cell lines, accompanied by reduced ERK and AKT phosphorylation. Furthermore, INCB003619, in combination with trastuzumab, augments the pro-apoptotic and antiproliferative effects of the chemotherapeutic agent paclitaxel. Consistent with these in vitro data, INCB003619 reduces serum ECD levels and enhances the antitumor effect of trastuzumab in a xenograft tumor model derived from the HER-2 overexpressing BT-474 breast cancer cell line. Collectively, these findings suggest that blocking HER-2 cleavage with selective ADAM inhibitors may represent a novel therapeutic approach for treating HER-2 overexpressing breast cancer patients.     

Resistance to human epidermal growth factor receptor type 2-targeted therapies

The overexpression of the human epidermal growth factor receptor type 2 (HER-2) is an independent prognostic factor of poor outcome in patients with breast cancer. Two compounds have been registered for HER-2-positive tumour treatment: trastuzumab, a humanised antibody directed against the HER-2 extracellular domain, and lapatinib, a small molecule acting as a dual EGF-R and HER-2 tyrosine kinase inhibitor. Although both drugs improve progression-free survival, many patients’ tumours will exhibit primary resistance, or develop secondary resistance, to anti-HER-2 therapies. The recent significant improvement of survival gained with pertuzumab (an antibody disrupting dimerisation of the receptor) or trastuzumab emtansine (T-DM1, a cytotoxic drug vectored by trastuzumab binding) opened the way for new registrations.This review describes the molecular mechanisms by which tumour cells may adapt to and evade HER-2 inhibition by HER-2-targeted therapies and discusses strategies to prevent and overcome resistance to trastuzumab and lapatinib. These strategies may include the establishment of predictive markers, exploration of combination therapies and modulation of nodal targets.     

The Her-2/neu gene and protein in breast cancer 2003: biomarker and target of therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. In this review, the association of HER-2/neu gene and protein abnormalities with prognosis and response to therapy with trastuzumab and to other therapies in breast cancer is presented. By considering a series of 80 published studies encompassing more than 25,000 patients, the relative advantages and disadvantages of Southern blotting, polymerase chain reaction amplification, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is presented as well as its potential impact on responses to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review also evaluates the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.     

Role of the combination of trastuzumab and taxanes in the therapeutic management of cancer of the breast: from preclinical data to clinical application

Taxanes are major drugs in the treatment of breast metastatic cancer. Since 1990, the mechanisms implicated in carcinogenesis are better understood and the oncoprotein HER2 is a potential target. Trastuzumab is a monoclonal antibody that binds to this transmembrane glycoprotein. This antibody demonstrated a significant activity in clinical trials. In this review, we discuss the preclinical (mechanisms of action) and clinical data with the combination of trastuzumab and taxanes.     

Experimental chemotherapy for xenograft cell lines of human bile duct and gall bladder cancers in nude mice.

Most biliary tract cancers are advanced and inoperable when first diagnosed. Even if surgery can be performed, the postsurgical prognosis of these diseases is poor. In the present study, we investigated effective chemotherapies for a human bile duct cancer xenograft cell line (undifferentiated carcinoma, BDC-SN) and a gall bladder cancer xenograft cell line (well-differentiated adenocarcinoma, GBC-GN), which were transplanted into nude mice. Eight anticancer agents (CDDP, 5-FU, VDS, MMC, ADR, EPIR, CQ, and VP-16) and their various combinations were evaluated at 2-4 times the clinical dose. When used singly, CDDP, 5-FU, and VDS were effective against BDC-SN, and only CDDP was effective against GBC-GN. Among the various 2-agent combinations, CDDP + 5-FU was the most effective against both BDC-SN and GBC-GN. However, 3-agent combinations consisting of CDDP + 5-FU + another agent were less effective than the CDDP + 5-FU double regimen and caused significant loss of weight as well as high mortality. These results suggest that CDDP + 5-FU may be the most useful regimen against biliary tract cancers in clinical application.