Hisatsugu Ohori

Synthesis and biological analysis of new curcumin analogues bearing an enhanced potential for the medicinal treatment of cancer

Curcumin (diferuloylmethane) is a dietary phytochemical with low toxicity that exhibits growth-suppressive activity against a variety of cancer cells and possesses certain chemopreventive properties. Curcumin has already been the subject of several clinical trials for use as a treatment in human cancers. Synthetic chemical modifications of curcumin have been studied intensively in an attempt to find a molecule with similar but enhanced properties of curcumin. In this study, a series of novel curcumin analogues were synthesized and screened for anticancer activity. New analogues that exhibit growth-suppressive activity 30 times that of curcumin and other commonly used anticancer drugs were identified. Structurally, the new analogues are symmetrical 1,5-diarylpentadienone whose aromatic rings possess an alkoxy substitution at each of the positions 3 and 5. Analysis of the effects of the analogues on the expression of cancer-related genes usually affected by curcumin indicated that some induced the down-regulation of β-catenin, Ki-ras, cyclin D1, c-Myc, and ErbB-2 at as low as one eighth the concentration at which curcumin normally has an effect. The analogues, however, exhibited neither harmful nor growth-suppressive effects on normal hepatocytes where oncogene products are not activated. They also exhibited no toxicities in vivo that they may provide effective alternative therapies for the prevention and treatment of some human cancers. [Mol Cancer Ther 2006;5(10):2563–71]

Newly synthesized curcumin analog has improved potential to prevent colorectal carcinogenesis in vivo

Curcumin (diferuloylmethane) has chemopreventive and chemotherapeutic potentials against various types of cancers. We have developed a series of curcumin analogs to improve its low bioavailability by enhancing its potentials. The newly synthesized analog GO‐Y030 [(1E, 4E)‐1,5‐bis‐(3,5(‐bismethoxymethoxyphenyl) penta‐1,4‐dien‐3‐one] showed a 30‐fold greater growth suppression in vitro via similar molecular mechanisms to curcumin. The availability of this analog was examined by using a mouse model harboring the germ‐line mutation of Apc, Apc580D/+, in vivo. Apc580D/+ mice had a very limited survival time with an intestinal obstruction due to polyposis. The average tumor number in mice fed GO‐Y030 was reduced to 61.2% of those that were fed the basal diet (P < 0.05). Compared with Apc580D/+ mice fed the basal diet (median survival time = 166.5 days), a significantly prolonged lifespan (213 days) was observed in Apc580D/+ mice fed GO‐Y030. The chemopreventive effect with GO‐Y030 was improved, compared with curcumin (191 days). The survival benefit corresponded to the diminished intestinal tumor incidence in Apc580D/+ mice fed GO‐Y030. No adverse reactions were observed, judging from body weight or biochemical data concerning liver and renal damage. Degradation of accumulated β‐catenin with curcumin is one of the major mechanisms of chemoprevention in colorectal carcinogenesis. It was demonstrated that the number of β‐catenin‐positive adenoma cells in Apc580D/+ mice fed GO‐Y030 was reduced. (Cancer Sci 2009; 100: 956–960)

Structure-activity relationship of C5-curcuminoids and synthesis of their molecular probes thereof.

A series of novel analogues of 1,5-bis(4-hydroxy-3-methoxyphenyl)-penta-(1E,4E)-1,4-dien-3-one (C(5)-curcumin), which is a natural analogue of curcumin isolated from the rhizomes of Curcuma domestica Val. (Zingiberacea), were synthesized and evaluated for their cytotoxicities against human colon cancer cell line HCT-116 to conclude the SAR of C(5)-curcuminoids for further development of their use in cancer chemotherapy: (1) Bis(arylmethylidene)acetone serves as a promising skeleton for eliciting cytotoxicity. (2) The 3-oxo-1,4-pentadiene structure is essential for eliciting cytotoxicity. (3) As for the extent of the aromatic substituents, hexasubstituted compounds exhibit strong activities, in which 3,4,5-hexasubstitution results in the highest potency. (5) The symmetry between two aryl rings is not an essential requirement for bis(arylmethylidene)acetones to elicit cytotoxicity. (6) para-Positions allows the installation of additional functional groups for use as molecular probes. By taking advantage of the SAR diagram, we have elaborated several advanced derivatives having GI(50) of single-digit micromolar potencies that will function as molecular probes to target and/or report key biomolecules interacting with curcumin and C(5)-curcumin.

Curcumin analog GO‐Y030 is a novel inhibitor of IKKβ that suppresses NF‐κB signaling and induces apoptosis

Curcumin is a dietary constituent with tumor‐suppressing potential, inhibiting various pathways involved in carcinogenesis. However, because of its low bioavailability, the use of curcumin in in vivo trials has been limited. To overcome this problem, we synthesized more than 50 analogs and identified a monoketone analog, GO‐Y030, which has a 30‐fold higher potential to suppress tumor cell growth compared with curcumin. We investigated the inhibitory effect of GO‐Y030 on NF‐κB activation. In thyroid, pancreatic cancers and cholangiocarcinoma cells, in which NF‐κB is activated, NF‐κB activation was suppressed to 8–62% of the control value following treatment with 1 μM GO‐Y030, an effect comparable to that of 10 μM curcumin. Direct inhibition of IKKβ kinase activity and suppression of nuclear translocation of the NF‐κB p65 subunit were observed. The 50% growth inhibition concentrations of GO‐Y030 ranged from one‐11th to one‐14th of those of curcumin. GO‐Y030 also induced cell death comparable to that induced by curcumin but at a 10‐fold lower concentration. In pancreatic and thyroid cancer cells, the growth‐inhibitory effect of GO‐Y030 was 4‐ and 15‐fold greater, respectively, than that of curcumin. GO‐Y030 was a much stronger inducer of apoptosis compared with curcumin. The enhanced potency of GO‐Y030 may make it more useful than curcumin, which suffers from low bioavailability. GO‐Y030 is a good lead compound for the development of useful compounds for practical cancer chemotherapy. (Cancer Sci 2011; 102: 1045–1051)

Synthesis of 86 species of 1,5-diaryl-3-oxo-1,4-pentadienes analogs of curcumin can yield a good lead in vivo

BackgroundCurcumin is known to possess many anti-tumor properties such as inhibition of tumor growth and induction of apotosis. However, limited bioavailability of curcumin prevents its clinical application. A synthesized curcumin analog, 1,5-diaryl-3-oxo-1,4-pentadiene such as GO-Y030, has the improved anti-tumor potential in vitro as well as in mouse model of colorectal carcinogenesis.ResultsThese compounds were divided into two groups; one is the higher anti-proliferative group, in which 79.7% of 1,5-diaryl-3-oxo-1,4-pentadienes were clustered. One of the 1,5-diaryl-3-oxo-1,4-pentadiene analogs, GO-Y078 has the most enhanced growth inhibition, and its solubility was improved, compared with curcumin. GO-Y078 inhibits NF-κB transactivation, as well as expression of TP53 and DR5 more effectively than curcumin. In a mouse model, GO-Y078 presented 1.4 fold more survival elongation that was not achieved by curcumin and GO-Y030.ConclusionsThe 1,5-diaryl-3-oxo-1,4-pentadiene analogs can yield good lead compounds for cancer chemotherapy, to overcome low bioavailability of curcumin.

KSRP/FUBP2 Is a Binding Protein of GO-Y086, a Cytotoxic Curcumin Analogue

Bis(arylmethylidene)acetone derivatives are an important class of curcumin analogues that exhibit various biological and pharmacological activities. We herein report that GO-Y086, a biotinylated bis(arylmethylidene)acetone, inhibits cancer cell growth. We also show that GO-Y086 specifically interacts with the nuclear protein KSRP/FUBP2 by covalent modification. GO-Y086 markedly suppresses the expression of the c-Myc protein, which plays an important role in cellular proliferation and whose expression is regulated by KSRP/FUBP2.

Safety Verification Trials of mFOLFIRI and Sequential IRIS + Bevacizumab as First- or Second-Line Therapies for Metastatic Colorectal Cancer in Japanese Patients

Objective: S-1 is effective in sequential combination with irinotecan (IRIS) in treating metastatic colorectal cancer. We conducted a randomized phase II trial of modified leucovorin, fluorouracil and irinotecan (mFOLFIRI) + bevacizumab and sequential IRIS + bevacizumab as first- or second-line therapies. Methods: Sixty metastatic colorectal cancer patients were randomly assigned to receive mFOLFIRI + bevacizumab or sequential IRIS + bevacizumab (7.5 mg/kg of bevacizumab and 150 mg/m2 of irinitecan, and 80 mg/m2/day of S-1 orally from day 3 until day 16 as a 3-week course). The primary endpoint was the safety of each method until week 12, with the secondary endpoint being the comparison of the safety and efficacy of the two methods. Results: The safety of the two treatments was comparable, except that G3 anorexia and diarrhoea were less frequent with sequential IRIS + bevacizumab. The overall response rate was 62% [95% confidence interval (CI) 40.1–79.8] versus 72% (95% CI 50.6–86.2), and progression-free survival was 324 days (95% CI 247–475) versus 345 days (95% CI 312–594) with mFOLFIRI + bevacizumab versus IRIS + bevacizumab, respectively. Conclusion: Sequential IRIS + bevacizumab is a safe and effective method of systemic chemotherapy against metastatic colorectal cancer and is compatible with mFOLFIRI + bevacizumab.

Efficacy and safety of gemcitabine plus docetaxel in Japanese patients with unresectable or recurrent bone and soft tissue sarcoma: Results from a single-institutional analysis

Background Combination therapy with gemcitabine and docetaxel has been reported to be a good therapeutic strategy for patients with soft tissue sarcoma. The aim of the present study was to analyze the efficacy and toxicity of gemcitabine with docetaxel in Japanese patients with advanced bone and soft tissue sarcoma. Patients and methods We retrospectively analyzed the effect of gemcitabine and docetaxel therapy on overall response, progression-free survival, overall survival, and toxicity in 42 patients with bone or soft tissue sarcoma who had received the therapy between October 2006 and September 2015, at Tohoku University Hospital. Results The median age was 55 years; 23 patients were men, and 19 were women. Eight had bone sarcoma and 34 had soft tissue sarcoma. Forty patients (95%) had previously been treated with one or more chemotherapeutic regimens. The overall response rate was 6.9% and the disease control rate was 55%. The median progression-free survival was 2.3 months and the median overall survival was 14.3 months. Grade 3 or more neutropenia and febrile neutropenia were observed in 74% and 4.8% of all patients, respectively. Conclusion The response rate was lower and myelosuppression was more frequently observed than in other previous reports. On the other hand, most of toxicities were enough manageable. In addition, some patients had long survival with a good response. Our study supports the notion that gemcitabine and docetaxel therapy is a good therapeutic option for treating patients with advanced soft tissue sarcoma as well as bone sarcoma, also in Asian populations.

Efficacy and Safety of Trastuzumab in Combination with S-1 and Cisplatin Therapy for Japanese Patients with HER2-Positive Advanced Gastric Cancer: Retrospective Analysis

The combinations of oral fluoropyrimidines and cisplatin such as capecitabine and cisplatin (XP) or S-1 and cisplatin (SP) are regarded as a standard therapy against unresectable, recurrent, or advanced gastric cancer (AGC). Especially, SP is the most common regimen against AGC in Japan. For patients with human epidermal growth factor receptor type 2 (HER2)-positive AGC, trastuzumab, a monoclonal antibody targeting HER2 antibody, is additionally used in combination. Although trastuzumab in combination with XP (trastuzumab-XP) have been widely accepted, the efficacy of trastuzumab in combination with SP (trastuzumab-SP) lacks sufficient verification. The aim of the present study is to validate the comparability of trastuzumab-SP to trastuzumab-XP. Patients with HER2-positive AGC were assigned to the trastuzumab-XP or trastuzumab-SP group. We then retrospectively compared the efficacy and safety between both groups. As a first-line chemotherapy, trastuzumab in combination with XP or SP was administered to 58 patients: 28 with trastuzumab-XP and 30 with trastuzumab-SP. In the trastuzumab-XP group, response rate (RR), disease control rate (DCR), median progression-free survival (mPFS), and median overall survival (mOS) were 39.3%, 89.3%, 7.9 months, and 20.0 months, respectively. In the trastuzumab-SP group, RR, DCR, mPFS and mOS were 50.0%, 86.7%, 6.9 months, and 16.7 months, respectively. No significant difference in efficacy was observed between both groups. Severe hand-foot syndrome was observed more frequently in the trastuzumab-XP group than in the trastuzumab-SP group (14.3% vs. 0%, p = 0.05). Trastuzumab in combination with SP is a potential first-line therapeutic option for patients with HER2-positive AGC.

Intermittent Withdrawal of Oxaliplatin for Alleviating Neurotoxicity during Oxaliplatin-Based Chemotherapy for Japanese Patients with Inoperable or Metastatic Colorectal Cancer: A Phase 2 Multicenter Study

Oxaliplatin-based chemotherapy is a well-established regimen for patients with inoperable and metastatic colorectal cancer. However, one of the major limitations of oxaliplatin-based chemotherapy is sensory neuropathy. It was previously reported that introduction of intermittent oxaliplatin treatment to an oxaliplatin-based regimen has a significant benefit on efficacy or safety. Here, we prospectively assessed whether efficacy and safety of first-line chemotherapy for advanced colorectal cancer are achieved by introduction of withdrawal of oxaliplatin treatment for a certain period (intermittent oxaliplatin treatment). The primary endpoint of the present study is to assess the progression free survival time on patients treated with chemotherapy (mFOLFOX6 (levofolinate, 5-fluorouracil and oxaliplatin combination therapy) plus bevacizumab or CapeOX (oxaliplatin and capecitabine combination therapy) plus bevacizumab) with intermittent oxaliplatin treatment. Bevacizumab is a humanized anti-vascular endothelial growth factor antibody. Median progression-free survival by the mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or the CapeOX plus bevacizumab with intermittent oxaliplatin treatment were 10.6 months (95% confidential interval [CI], 8.3-13.4 months) or 8.0 months (95% CI, 4.2-16.8 months), respectively. Overall response rate by the mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or CapeOX plus bevacizumab with intermittent oxaliplatin treatment was 55.1% or 42.1%, respectively. Grade 3 or 4 neuropathy was observed in 4.1% or 10.5% of patients treated with mFOLFOX6 plus bevacizumab with intermittent oxaliplatin treatment or CapeOX plus bevacizumab with intermittent oxaliplatin treatment, respectively. Introduction of intermittent oxaliplatin treatment has improved severe neuropathy in mFOLFOX6 plus bevacizumab regimen without reducing treatment efficacy.