Potential anti-cancer activity of N-hydroxy-7-(2-naphthylthio) heptanomide (HNHA), a histone deacetylase inhibitor, against breast cancer both in vitro and in vivo

Histone deacetylase (HDAC) is an attractive target for cancer therapy because it plays a key role in gene expression and carcinogenesis. N-hydroxy-7-(2-naphthylthio) heptanomide (HNHA) is a novel synthetic HDAC inhibitor (HDACI) that shows better pharmacological properties than a known HDACI present in the human fibrosarcoma cell: suberoylanilide hydroxamic acid (SAHA). Here, we investigate the anti-cancer activity of HNHA against breast cancer both in vitro and in vivo. HNHA arrested the cell cycle at the G(1) /S phase via p21 induction, which led to profound inhibition of cancer cell growth in vitro. In addition, HNHA-treated cells showed markedly decreased levels of VEGF and HIF-1α than SAHA and fumagillin (FUMA) when accompanied by increased histone acetylation. HNHA significantly inhibited tumor growth in an in vivo mouse xenograft model. HNHA-treated mice survived significantly longer than SAHA- and FUMA-treated mice. Dynamic MRI showed significantly decreased blood flow in the HNHA-treated mice, implying that HNHA inhibits tumor neovascularization. This finding was accompanied by marked reductions of proangiogenic factors and significant induction of angiogenesis inhibitors in tumor tissues. We have shown that HNHA is an effective anti-tumor agent in breast cancer cells in vitro and in breast cancer xenografts in vivo. Collectively, these findings indicate that HNHA may be a potent anti-cancer agent against breast cancer due to its multi-faceted inhibition of HDAC activity, as well as anti-angiogenesis activity.     

Combination therapy for advanced pancreatic cancer using Herceptin plus chemotherapy

The HER2/neu oncogene is overexpressed in up to 70% of human pancreatic cancer specimens when compared to normal pancreatic tissue. This cell surface receptor can be targeted specifically by the neutralizing antibody Herceptin. Herceptin has been successfully used in combination with other chemotherapeutic agents in breast cancer, a cancer in which only 30% of patients harbor elevated HER2/neu levels. In the present study, we investigated the therapeutic efficacy of Herceptin in combination with gemcitabine and docetaxel. Gemcitabine is currently the standard chemotherapeutic agent used to treat pancreatic cancer. In contrast, docetaxel, a taxane, is only just being investigated in pancreatic cancer. Tumor cell resistance to taxanes is at least in part mediated by the HER2/NEU oncogene. We have previously characterized HER2/NEU expression in human pancreatic cancer cell lines and studied the anti-tumor activity of Herceptin monotherapy in vitro and in vivo. In the present study, combination therapy resulted in a dramatic improvement of animals bearing human pancreatic cancer xenografts. Furthermore, metastasis and production of ascites was lower when a combination of these three agents was used. We conclude that, as with breast cancer, the anti-tumor activity of Herceptin may be improved by combination with taxanes or gemcitabine.     

Dose-dense Vinorelbine and Paclitaxel with Granulocyte Colony-stimulating Factor in Metastatic Breast Cancer Patients: Anti-tumor Activity and Peripheral Blood Progenitor Cell Mobilization Capability

We studied the safety, activity and peripheral blood progenitor cell mobilizing capability of a dose-dense combination of vinorelbine (VNB) and paclitaxel (PTX) as first-line chemotherapy for patients with metastatic breast cancer (MBC). Forty-three MBC patients were submitted to four cycles of VNB 30 mg/m2 and PTX 175 mg/m2 intravenously, every 2 weeks, as the first induction step of a tandem high-dose chemotherapy program. Granulocyte colony-stimulating factor (G-CSF) 5 microg/kg was administered daily from day +5 to +10 in order to accelerate hematopoietic recovery, or 48h after the last VNB-PTX when a leukapheresis was planned (after the third or fourth cycle). A total of 172 cycles were administered. The mean delivered dose-intensity of VNB and PTX was 14.7 and 86 mg/m2/week, respectively (98% of the planned dose-intensity). The main per-patient toxicities were: peripheral neurotoxicity (G1/2 60%, G3 5%), constipation (G1/2 10%), oral mucositis (G1/2 20%), and asthenia (G1/2 35%). Hematological toxicity was unremarkable, except for anemia with hemoglobin (Hb) values < 10 g/dl (28%), and lymphopenia with lymphocyte counts < 1000/mm3 (28%). Two complete (5.1%) and 24 partial (61.5%) responses were observed in 39 assessable patients, for an overall response rate of 66.6% (95% CI 51.6-80.9). A median of one apheretic procedure (range 1-3) was required to achieve the target number of 6 x 10(6)/kg CD34+ cells. The median number of CD34+ harvested per patient was 15 x 10(6)/kg (range 6.4-36.5). Four cycles of dose dense VNB and PTX showed a favorable toxicity profile, a relevant anti-tumor activity and a high peripheral blood progenitor cell mobilizing activity.     

Improved therapeutic efficacy of unmodified anti-tumor antibodies by immune checkpoint blockade and kinase targeted therapy in mouse models of melanoma

The use of specific anti-tumor antibodies has transformed the solid cancer therapeutics landscape with the relative successes of therapies such as anti-HER2 in breast cancer, and anti-EGFR in HNSCC and colorectal cancer. However, these therapies result in toxicity and the emergence of resistant tumors. Here, we showed that removing immune suppression and enhancing stimulatory signals increased the anti-tumor activity of unmodified TA99 antibodies (anti-TYRP1) with a significant reduction of growth of solid tumors and lung metastases in mouse models of melanoma. Immune checkpoint blockade enhanced the efficacy of TA99, which was associated with greater CD8⁺/Foxp3⁺, NK1.1⁺ and dendritic cell infiltrates, suggestive of an increased anti-tumor innate and adaptive immune responses. Further, MEK inhibition in melanoma cell lines increased the expression of melanosomal antigens in vitro, and combining TA99 and MEKi in vivo resulted in enhanced tumor control. Moreover, we found an improved therapeutic effect when YUMM tumor-bearing mice were treated with TA99 combined with MEKi and immune checkpoint blockade (anti-PD1 and anti-CTLA4). Our findings suggest that MEKi induced an increased expression of tumor-associated antigens, which in combination with anti-tumor antibodies, generated a robust adaptive anti-tumor response that was sustained by immune checkpoint inhibition therapy. We postulate that combining anti-tumor antibodies with standard-of-care strategies such as immune checkpoint blockade or targeted therapy, will improve therapeutic outcomes in cancer.     

Combined 4-hydroxy-ifosfamide and vinorelbine treatment in established and primary human breast cell cultures

Background:Vinorelbine and ifosfamide are active drugs againstbreast cancer, but the best treatment schedule has yet to be defined bypreclinical or clinical studies. The antitumor activity of4-hydroxy-ifosfamide (4-OH-IF), the active form of ifosfamide, and vinorelbine(VNB) and their interaction were investigated in two established breast cancercell lines (MCF-7 and BRC-230) and in 10 primary breast cancer cultures. Materials and methods:Cytotoxic activity was evaluated by ahighly efficient clonogenic assay (HECA). The median-effect principle wasapplied to evaluate synergistic and antagonistic interactions and thecorresponding combination index values were calculated. Cell cycleperturbations were analysed by flow cytometry. Results:In MCF-7 and BRC-230 cell lines the sequence VNB for 4hours followed by 4-OH-IF for 24 hours produced an antagonistic effect.Conversely, the inverse sequential scheme, 4-OH-IF VNB providedsynergistic effects on both cell lines. The synergism was associated with astrong block in the G2-M phase. Synergistic activity of 4-OH-IF VNBsequence was confirmed in 7 of 10 primary breast cancercultures. Conclusions:In conclusion, the sequence 4-OH-IF VNBappeared to be the most effective scheme both in established cell lines andin primary breast cancer cultures.     

In vitro Anti-tumor Activity of Anti-c-erbB-2 × Anti-CD3ɛ Bifunctional Monoclonal Antibody

With the aim of developing an effective cancer immunotherapy for common epithelial cancer, a new class of bifunctional antibody (BFA) was developed; one arm of this BFA recognized c- erb B-2 gene product, and the other arm recognized CD3ɛ, a T-cell specific surface antigen. Application of this BFA with human peripheral blood lymphocytes exhibited specific anti-tumor activity in vitro on a breast tumor cell line, ZR-75–1, which expressed abundant c- erbB -2 gene product on its cell surface. These results indicate that BFA recognizing an oncogene product on cell surface is a potential new agent for cancer immunotherapy.     

In vitro anti-tumor activity of anti-c-erbB-2 x anti-CD3 epsilon bifunctional monoclonal antibody.

With the aim of developing an effective cancer immunotherapy for common epithelial cancer, a new class of bifunctional antibody (BFA) was developed; one arm of this BFA recognized c-erbB-2 gene product, and the other arm recognized CD3 epsilon, a T-cell specific surface antigen. Application of this BFA with human peripheral blood lymphocytes exhibited specific anti-tumor activity in vitro on a breast tumor cell line, ZR-75-1, which expressed abundant c-erbB-2 gene product on its cell surface. These results indicate that BFA recognizing an oncogene product on cell surface is a potential new agent for cancer immunotherapy.     

乳腺癌抗血管生成治疗的研究进展

新生血管生成是恶性肿瘤的增殖过程中的关键步骤,因此抗血管生成已成为抗肿瘤治疗的重要策略和研究热点。本文就乳腺癌抗肿瘤血管生成治疗的研究背景、应用现状、未来展望作一综述。     

Treatment outcomes with vinorelbine for metastatic breast cancer patients previously treated with both doxorubicin and docetaxel]

The purpose of this study was to evaluate the efficacy and toxicity of weekly vinorelbine (VNB) in patients with metastatic breast cancer previously treated with both adriamycin (ADM) and docetaxel (TXT). VNB was administered weekly at the dose 20 mg/m2 by i.v. infusion over 20 minutes followed by flushing the vein with 100 ml of normal saline. From June 1999 to August 2000, ten patients were enrolled in this study. Patient characteristics were that the cumulative doses (median) of previous ADM and TXT were 300 mg (range, 120-880 mg), 560 mg (range, 120-960 mg) respectively. The median number of metastatic sites was four, with poor performance status (ECOG 1-2: 40%, 3-4: 60%). The median cycles of weekly VNB were seven (range: 2-12). Two of 10 assessable patients obtained partial response, with an overall response rate of 20%. The main toxicity (NCI grade 4) was leukopenia in 10% of 10 patients. Phlebitis (grade 2) was observed in 4 of 10 patients (40%). VNB is an active agent against metastatic breast cancer pretreated with both ADM and TXT, possessing no severe toxicities.     

Differential effects of estrone and estrone-3-O-sulfamate derivatives on mitotic. Arrest, apoptosis, and microtubule assembly in human breast cancer cells

There is considerable interest in the potential use of estrogen derivatives for the treatment and prevention of breast cancer. We demonstrated previously that the sulfamoylated estrone derivative 2-methoxyestrone-3-O-sulfamate (2-MeOEMATE) induced G2-M cell cycle arrest and modest levels of apoptosis in breast cancer cells in vitro, whereas the parent estrone derivative, 2-methoxyestrone, did not. 2-MeOEMATE also induced breast tumor regression in vivo in intact rats. To further explore the significance of sulfamoylation on the anticancer activity of estrone derivatives and to elucidate their mechanism of action, we synthesized two additional agents, 2-ethylestrone and 2-ethylestrone-3-O-sulfamate (2EtEMATE). 2-MeOEMATE and 2-EtEMATE inhibited the growth of a panel of estrogen receptor-negative and -positive breast cancer cell lines in vitro, induced mitotic arrest and apoptosis, and suppressed the long-term clonogenic potential of MCF7 and CAL51 breast cancer cells. In each assay, the sulfamoylated estrone derivatives were >10-fold more potent than their parent compounds. The sulfamoylated estrone derivatives were also significantly more potent inhibitors of cell growth than the previously studied endogenous estradiol metabolite 2-methoxyestradiol. 2-MeOEMATE and 2-EtEMATE functioned as antimicrotubule agents and inhibited the ability of paclitaxel to promote tubulin assembly in vitro. Like other antimicrotubule agents, the sulfamoylated estrone derivatives induced BCL-2 and BCL-XL phosphorylation and increased p53 expression. 2-MeOEMATE and 2-EtEMATE are novel antimicrotubule agents that have potent anticancer activity in breast cancer cells in vitro and may be beneficial as anticancer agents in vivo.     

Trastuzumab emtansine (T-DM1): a novel agent for targeting HER2+ breast cancer

Increased understanding of the molecular mechanisms of tumorigenesis has led to the development of novel agents that target tumor cells with minimal effects on normal cells. The success of this approach is exemplified by the development of monoclonal antibodies directed toward antigens expressed selectively by tumor cells. The conjugation of these monoclonal antibodies with potent cytotoxic drugs has the potential to further improve efficacy while retaining a favorable safety profile. Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate (ADC) currently in clinical development. It combines the humanized antibody trastuzumab, which targets the human epidermal growth factor receptor 2 (HER2) receptor on cancer cells, and the potent antimicrotubule agent DM1 using a unique highly stable linker. When T-DM1 binds to HER2, a proportion of the receptors are thought to be internalized by the process of receptor endocytosis, followed by the intracellular release of an active form of DM1, which in turn kills the tumor cell. This review presents the rationale for the development of T-DM1 and summarizes the preclinical and clinical data for this novel agent for the treatment of breast cancer.     

Vinorelbine-induced neurotoxicity in patients with advanced breast cancer pretreated with paclitaxel – a phase II study

 Vinorelbine (VNB) shows high antitumoral activity in advanced breast cancer due to its high affinity for mitotic tubulin and differs from the other vinca alkaloids with regard to its low degree of neurotoxicity because of its low affinity for axonal tubulin. Preclinical data show the existence of different binding sites on tubulin for vinca alkaloids and paclitaxel (P), suggesting a lack of cross-resistance. Thus, VNB was chosen eligible for a phase II study to evaluate both the therapeutic efficacy and the toxicity of VNB in patients (pts) with advanced breast cancer failing first-or second-line chemotherapy with P. A total of 14 pts with advanced breast cancer pretreated with P were entered into the study. Therapy consisted of VNB at 30 mg/m² diluted in 500 ml of normal saline given over 30 min after a minimal interval of 4 weeks since the last application of P. For the first four cycles, injections were repeated at 2-week intervals; thereafter they were repeated at 3-week intervals until evidence of progressive disease or severe toxicity developed. All but one pt was considered assessable for response and all pts were evaluable for toxicity. No objective response was observed; two pts showed no change in their disease. In four pts therapy had to be stopped because peripheral neurotoxicity increased from a pretherapeutic level after therapy with P from National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 1 (n=3) and 2 (n=1) to neurotoxicity grade 3 after 1, 2 (n=2), and 3 cycles of therapy with VNB, respectively. In addition, constipation of grade 2 occurred in 10 pts. Hematologic toxicity was negligible. No other evaluable toxicity exceeded NCI-CTC grade 1. Both observations of this study, the complete resistance to VNB and the increase in peripheral neuropathy, let us assume the existence of a preclinically not anticipated but clinically relevant cross-resistance between these two spindle poisons and the presence of common functional targets. Therefore, P-pretreated pts should be excluded from consecutive VNB-containing therapies. Received: 5 November 1995/Accepted: 11 April 1996     

Rational design of the microtubule-targeting anti-breast cancer drug EM015

We studied in silico docking of noscapine onto tubulin, combined with calculations of surface charge, pi-pi, van der Waals, and hydrogen bonding interactions, to rationally design a new compound, EM015. This tubulin-binding semisynthetic compound is a selective and potent anti-breast cancer agent and displays a 20-fold lower IC(50) against many tumor cells compared with our founding compound, (S)-6,7-dimethoxy-3-((R)-4-methoxy-6-methyl-5,6,7,8-tetrahydro[1,3]-dioxolo-[4,5-g]isoquinolin-5-yl)isobenzo-furan-1(3H)-one (noscapine). Furthermore, EM015 is also effective against a variety of drug-resistant cells. Surprisingly, the cell cycle profile of nontumorigenic normal cells is not affected. Many antimicrotubule cancer drugs in clinic today, particularly taxanes and Vincas, face challenges including frequent visits to the hospital for prolonged i.v. infusions, toxicities, and tumor recurrences due to drug resistance. EM015, on the other hand, is orally available, regresses breast tumor xenografts in nude mice models, and increases longevity. Furthermore, we have failed to observe any detectable toxicity in tissues, such as liver, kidney, spleen, lung, heart, and brain, as well as neurons, which are common targets of antimicrotubule drug therapy. Thus, EM015 has a great promise in the clinic.     

Low-Dose Metronomic Oral Administration of Vinorelbine in the First-line Treatment of Elderly Patients With Metastatic Breast Cancer

BackgroundThe concept of metronomic chronic administration of low-dose chemotherapy has become relevant for the treatment of cancer in the last several years. This study sought to determine the safety and activity of oral vinorelbine (VNB), using a metronomic schedule of administration, in elderly patients with metastatic breast cancer (MBC).Patients and MethodsFrom October 2004 to March 2007, 34 patients with MBC (median age, 74 years; range, 70–84 years) were treated with oral VNB at 70 mg/m², fractionated on days 1, 3, and 5, for 3 weeks on and 1 week off, every 4 weeks, for a maximum of 12 cycles. The objective response rate was the primary endpoint.ResultsAll 34 patients received at least 3 cycles of therapy and were evaluable. Two achieved complete responses (6%), and 11 achieved partial responses (32%). Median progression-free survival and median overall survival entailed 7.7 months (95% confidence interval, 6.9-9.05 months) and 15.9 months (95% CI, 13.1-15.91 months), respectively, for all patients.ConclusionThe fractionated administration of oral VNB is well tolerated and presents promising activity in elderly patients with metastatic cancer, warranting further investigation in combination with other chemotherapy agents.     

Induction of antiproliferation and apoptosis in estrogen receptor negative MDA-231 human breast cancer cells by mifepristone and 4-hydroxytamoxifen combination therapy: a role for TGFbeta1

Mifepristone (MIF) is an antiprogestin with potent anti-glucocorticoid and anti-androgen activity. MIF also appears to have anti-tumor activity independent of its ability to bind to nuclear receptors. In this study, we tested the ability of MIF to inhibit the growth of ER and PR negative breast cancer cells. In addition, because high-dose anti-estrogen treatment has been shown to inhibit ER and PR negative breast cancer cells, we compared the anti-proliferative activity of MIF to that of the anti-estrogen 4-hydroxytamoxifen (TAM) or combination hormonal therapy (MIF + TAM). MIF and TAM therapy induced a significant time- and dose-dependent growth inhibition and, ultimately, induced cell death in MDA-231 cells as evidenced by increased DNA fragmentation, cytochrome c release from the mitochondria, and the activation of caspase-3. The anti-proliferative activity of TAM plus MIF combination treatment was at least additive as compared to either monotherapy. The earliest indicator of TAM and MIF cytostatic and cytotoxic action on MDA-231 cells was a significant (p<0.05) induction of TGFbeta1 secretion into the growth medium within 4 h of treatment. Secreted TGFbeta1 levels at 24 and 48 h were significantly higher in the TAM plus MIF treatment group as compared to cells treated with TAM or MIF alone. TGFbeta1 neutralizing antibody or addition of mannose-6-phosphate (M6P), a reagent also used to inhibit TGFbeta1, significantly attenuated the TAM and/or MIF-induced cell growth inhibition and cell death. In summary, our results indicate that MIF used in combination with TAM can effectively kill estrogen-insensitive human breast cancer cells. Our study further implies that agents that effectively increase TGFbeta1 levels in ER negative breast cancer cells may be one treatment approach for hormone-independent breast cancers.     

Preclinical pharmacology of the pyrrolobenzodiazepine (PBD) monomer DRH-417 (NSC 709119)

The pyrrolobenzodiazepine monomer DRH-417 is a member of the anthramycin group of anti-tumor antibiotics that bind covalently to the N2 of guanine within the minor groove of DNA. DRH-417 emerged from the EORTC-Drug Discovery Committee and NCI 60 cell line in vitro screening programs as a potent antiproliferative agent with differential sensitivity towards certain cancer types such as melanoma, breast and renal cell carcinoma (mean IC(50) = 3 nM). DRH-417 was therefore tested for in vivo activity. The maximum tolerated dose (MTD) was established as 0.5 mg/kg given i.p. Marked anti-tumor activity was seen in two human renal cell cancers, one breast cancer and a murine colon tumor model (p<0.01). A selective HPLC (LC/MS) analytical method was developed and plasma pharmacokinetics determined. At a dose of 0.5 mg kg(-1), the plasma AUC was 540 nM h (197.1 ng h ml(-1)) and the peak plasma concentration (171 nM [62.4 ng ml(-1)]) occurred at 30 min., reaching doses levels well above those needed for in vitro antiproliferative activity. Genomic profiling of in vivo sensitive tumors revealed that the latter have an activated insulin-like growth factor signaling pathway.     

Efficacy and toxicity of vinorelbine with doxorubicin/cyclophosphamide combination chemotherapy in a phase I-II study for advanced or recurrent breast cancer patients

BACKGROUND: To evaluate the efficacy and toxicity of vinorelbine (VNB) with doxorubicin/cyclophosphamide (AC) combination chemotherapy, a phase I-II study was carried out in patients with advanced or recurrent breast cancer. METHODS: The phase I part of this study was carried out to determine the treatment schedule and acceptable dose of VNB for the phase II study. In phase I, VNB was initially given as a short infusion on days 1, 8 and 15, every 4 weeks. The initial dose of vinorelbine was 15 mg/m2. In the AC regimen, 20 mg/m2 of doxorubicin (ADM) was given intravenously (i.v.) on days 1 and 8, and 100 mg/body of cyclophosphamide (CPA) was administered orally from days 1 to 14. Subsequently, a phase II study was carried out at the maximum acceptable dose (MAD). RESULTS: Twenty-three patients were entered into this study. In patients receiving VNB at a dose of 15 mg/m2, neutropenia (> or = grade 3) frequently occurred on day 15. The treatment schedule of this study was therefore changed to VNB given i.v. on days 1 and 8 with AC combination chemotherapy. In this treatment schedule, grade 4 neutropenia lasting for more than 4 days occurred in patients given VNB at a dose of 20 mg/m2 with AC more frequently than in those given 15 mg/m2 of VNB. Therefore, the MAD of VNB was determined to be 20 mg/m2 in this regimen. At this recommended dose, there were 1 complete (CR) and 8 partial responses (PRs) in 15 patients, with an overall response rate of 60.0%. No treatment-related death occurred. CONCLUSIONS: These data indicate that VNB plus AC combination chemotherapy was effective and well tolerated for breast cancer patients. A randomized trial of VNB plus AC vs. AC combination chemotherapy may be required to ascertain the benefit of this regimen for advanced or recurrent breast cancer patients.