HB-EGF Is a Promising Therapeutic Target for Lung Cancer with Secondary Mutation of EGFRT790M.

Advanced lung cancer is one of the most lethal malignancies. Many anticancer agents have been developed for lung cancer with epidermal growth factor receptor (EGFR) mutations, but its prognosis remains extremely poor. The development of molecularly-targeted therapies is required for patients with lung cancer with secondary mutation of the EGFR gene. In this study, in order to assess the validity of heparin-binding EGF-like growth factor (HB-EGF) as a therapeutic target for lung cancer with EGFR mutation, we examined the antitumor effects of a specific inhibitor (cross-reacting material 197; CRM197) on lung cancer cells with EGFR mutation. HB-EGF was the most predominantly expressed EGFR ligand in lung cancer cells with EGFR mutation. CRM197 induced significant cell apoptosis and marked suppression of tumorigenicity in lung cancer cells with single or double mutation of EGFR. These results suggest that HB-EGF is a rational target for the treatment of lung cancer with EGFR mutation.

Antitumour Effects of Intravenous Administration of BK-UM, a Novel Inhibitor of HB-EGF, in Ovarian Cancer Therapy.

BACKGROUND: Patients with ovarian cancer with high levels of heparin-binding epidermal growth factor-like growth factor have a poor prognosis. Here we assessed the pharmacokinetics and tumour-inhibiting effects of cross-reacting material 197, produced commercially as BK-UM, and examined the efficacy and safety of its intravenous (i.v.) administration. MATERIALS AND METHODS: BK-UM was administered to rats, and its serum levels were measured. Ovarian cancer cell lines were either intraperitoneally (i.p.) or subcutaneously administered into mice, to establish a mouse model of ovarian cancer. BK-UM was then administered i.p. or i.v., and its tumour-inhibiting effects were examined. RESULTS: Higher maximum serum concentration (Cmax) values resulted from i.v. administration, whereas longer time to maximum serum (Tmax) values resulted from i.p. administration. In the peritoneal dissemination model, i.p. administration inhibited tumour growth and increased survival rate, whereas in the subcutaneous model, i.v. administration significantly inhibited tumour growth compared to i.p. administration. CONCLUSION: Administration of BK-UM by i.v. is both efficacious and safe.

BK-UM in patients with recurrent ovarian cancer or peritoneal cancer: a first-in-human phase-I study.

BACKGROUND: BK-UM (CRM197) is a mutant form of diphtheria toxin and a specific inhibitor of heparin-binding epidermal growth factor-like growth factor (HB-EGF). We assessed the safety, pharmacokinetics, recommended dose, and efficacy of BK-UM in patients with recurrent ovarian cancer (OC) or peritoneal cancer (PC), and measured HB-EGF levels in serum and abdominal fluid after BK-UM administration. METHODS: Eleven patients with advanced or recurrent OC or PC were enrolled and treated with BK-UM via the intraperitoneal route. The dose was escalated (1.0, 2.0, 3.3, and 5.0 mg/m2) using a 3 + 3 design. RESULTS: Eight of 11 patients completed treatment. No dose-limiting toxicity (DLT) was experienced at dose levels 1 (1.0 mg/m2) and 2 (2.0 mg/m2). Grade 3 transient hypotension as an adverse event (defined as a DLT in the present study) was observed in two of four patients at dose level 3 (3.3 mg/m2). Treatment with BK-UM was associated with decreases in HB-EGF levels in serum and abdominal fluid in seven of 11 patients and five of eight patients, respectively. Clinical outcomes included a partial response in one patient, stable disease in five patients, and progressive disease in five patients. CONCLUSIONS: BK-UM was well tolerated at doses of 1.0 and 2.0 mg/m2, with evidence for clinical efficacy in patients with recurrent OC or PC. A dose of 2.0 mg/m2 BK-UM is recommended for subsequent clinical trials. TRIAL REGISTRATION: This trial was prospectively performed as an investigator-initiated clinical trial. The trial numbers are UMIN000001002 and UMIN000001001, with registration dates of 1/30/2008 and 2/4/2008, respectively. UMIN000001001 was registered as a trial for the continuous administration of BK-UM after UMIN000001002 .

Anti-tumor Effect of Intravenous Administration of CRM197 for Triple-negative Breast Cancer Therapy.

BACKGROUND/AIM: Heparin-binding epidermal growth factor-like growth factor (HB-EGF), which belongs to the epidermal growth factor family, is a rational therapeutic target for triple-negative breast cancer (TNBC). This study aimed to assess the anti-tumor efficacy of intravenous (i.v.) HB-EGF-specific inhibitor (CRM197) for TNBC. MATERIALS AND METHODS: NOD/SCID mice were subcutaneously injected withTNBC cells, MDA-MB-231, and, then, treated with i.v. CRM197 in either dose- or frequency-dependent manners, using an advanced cancer model and an adjuvant therapy model. Tumor volume and mouse body weight were calculated weekly. Statistical significance was assessed by the Mann-Whitney U-test. RESULTS: Mice that received i.v. CRM197 showed a significant anti-tumor effect in dose- and frequency-dependent manners in both models. However, their body weight did not differ significantly among groups. CONCLUSION: These results suggest that i.v. CRM197 is an effective treatment for TNBC.

Contribution of transcription factor, SP1, to the promotion of HB-EGF expression in defense mechanism against the treatment of irinotecan in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a worst histological subtype than other ovarian malignant tumor. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. The aims of this study were to validate the efficacy of HB-EGF-targeted therapy for OCCC and to identify the transcription factor that contributed to the induction of HB-EGF by SN38 treatment in OCCC cells. HB-EGF was highly expressed in OCCC cells, and an increase of HB-EGF was induced by SN38 which had only antitumor effect among conventional anticancer agents on OCCC. A specific inhibitor of HB-EGF, a cross-reacting material 197 (CRM197), led to a synergistic increase in the number of apoptotic OCCC cells with the treatment of SN38. The luciferase assay with 5'-deletion promoter constructs identified a GC-rich element between -125 and -178 (the distal transcription start site was denoted +1) as a cis-regulatory region, and the treatment of SN38 induced luciferase activity in this region. An in silico and chromatin immunoprecipitation analysis estimated that SP1 bound to the cis-regulatory region of HB-EGF in OCCC cells. Real-time PCR and cell viability assays showed that the transfection of a small interfering RNA targeting SP1 suppressed the expression of HB-EGF induced by SN38, resulting in the enhanced sensitivity of SN38. Taken together, these results indicate that induction of HB-EGF expression contributed to defense mechanism against treatment of SN38 through the transcriptional activity of SP1 in OCCC cells.

Pre-clinical study of BK-UM, a novel inhibitor of HB-EGF, for ovarian cancer therapy.

BACKGROUND/AIM: Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor family, is a target for ovarian cancer therapy. The present study investigated the administration schedule of BK-UM, an anticancer agent targeting HB-EGF. MATERIALS AND METHODS: The ovarian cancer cell line, RMG-I, was injected subcutaneously into five-week-old female nude mice. The BK-UM was administered intraperitoneally, using three administration schedules with different doses. The tumor volume was calculated every week. Statistical significance was assessed using the Mann-Whitney U-test. RESULTS: At doses >0.1 mg/kg, BK-UM displayed significant antitumor effects, although the antitumor effects and body weights of mice did not significantly differ by dose or by three different administration schedules. At a dose <0.1 mg/kg, however, BK-UM had little inhibitory effect on tumor growth. CONCLUSION: Daily administration of BK-UM, which has a potentially dose-dependent antitumor effect, may be the optimal schedule for clinical application.

Non-AIDS-defining hematological malignancies in HIV-infected patients: an epidemiological study in Japan.

OBJECTIVE: To clarify the incidence and clinical outcomes of non-AIDS-defining hematological malignancies (NADHMs), excluding non-Hodgkin's lymphomas, in HIV-infected patients. DESIGN: A nationwide epidemiological study was conducted to evaluate the incidence and clinical outcomes of NADHMs. METHODS: Questionnaires were sent to 429 regional AIDS centers and 497 educational hospitals certified by the Japanese Society of Hematology. Data from 511 institutes were obtained. RESULTS: From 1991 to 2010, 47 patients with NADHMs were detected (median age, 42.0 years; male, 93.6%). The median CD4-positive T-cell count was 255/µl, and the median duration from the diagnosis of HIV infection to development of hematological malignancy was 28.0 months. Most patients with acute leukemia were treated with standard induction chemotherapy. Complete remission rates and median overall survival periods for acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL) were 70.0 and 85.7% and 13 and 16 months, respectively. Three of four patients with chronic-phase chronic myeloid leukemia (CML-CP) were well controlled with imatinib. Five patients (2 AML, 1 ALL, 1 accelerated-phase CML, and 1 myeloma) were treated with autologous or allogeneic stem-cell transplantation. Comparison of patients over the two periods (1991-2000 and 2001-2009) revealed a 4.5-fold increase in the incidence of hematological malignancies. CONCLUSION: The incidence of NADHMs has increased in the past decade. The prognosis of these patients was similar to that of HIV-negative patients; therefore, standard chemotherapy may be a feasible treatment option for HIV-infected patients with hematological malignancies.

Antitumor effects of CRM197, a specific inhibitor of HB-EGF, in T-cell acute lymphoblastic leukemia.

The therapeutic outcome for T-cell acute lymphoblastic leukemia (T-ALL) remains poor; thus, novel, targeted therapies are urgently needed. Recently, we showed that heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the EGF family, is a promising target for the treatment of various types of cancer. The aim of the present study was to investigate whether HB-EGF is a therapeutic target for T-ALL, and to further elucidate the antitumor effects of a specific inhibitor of HB-EGF, cross-reacting material 197 (CRM197). We elucidated the expression of HB-EGF in T-ALL cell lines, and evaluated the effect of CRM197 on these cells alone or in combination with anticancer agent. The expression of EGFR and EGFR ligands was determined by flow cytometry, RT-PCR and real-time quantitative PCR. Induction of apoptosis was assessed by TUNEL assay. HB-EGF was strongly expressed by T-ALL cell lines, and the expression of both HB-EGF and EGFR was enhanced by doxorubicin. CRM197 induced apoptosis, and furthermore, the combination of CRM197 plus doxorubicin enhanced cytotoxicity in a T-ALL cell line. These results suggest that HB-EGF is a promising therapeutic target for T-ALL.

Investigation of emtricitabine-associated skin pigmentation and safety in HIV-1-infected Japanese patients.

Emtricitabine (FTC) has been reported to cause skin pigmentation (SP), and the incidence of SP associated with FTC varied with ethnicity, with a higher rate in African-American patients (8%). We assessed the incidence of SP in Japanese HIV-1-infected patients receiving combination antiretroviral therapy (cART) with FTC for a period of 48 weeks and confirmed new findings of FTC-associated SP, including pathological characteristics. This was a multicenter, prospective, longitudinal non-randomized study. We evaluated the appearance of SP at 48 weeks as the primary endpoint in 155 Japanese patients, and secondary endpoints included the characteristics of the SP (location, color tone, size, and progression). Six cases (3.9%) of SP occurred at a median of 124 days (range: 7-259 days) within 48 weeks. The SP looked like an isolated dark spot, 1-2 mm in diameter, mainly on the hands and/or feet. The severity of all the SPs was mild. Each SP had disappeared or faded at a median of 112 days (range: 28-315 days) with continued FTC. FTC-associated SP was considered to be lentigo simplex by dermatoscopy and pathological appearance. In summary, the incidence of FTC-associated SP in Japanese patients was 3.9%, and was comparable to the previously reported incidence in Asian patients (4%). FTC-associated SP was not associated with any clinically significant symptoms and has little clinical significance.

Long-term successful control of super-multidrug-resistant human immunodeficiency virus type 1 infection by a novel combination therapy of raltegravir, etravirine, and boosted-darunavir.

Drug-resistant virus infection has been a major hurdle in the management of human immunodeficiency virus type 1 (HIV-1) infection. Recently, three novel antiretrovirals [raltegravir (RAL), etravirine (ETR), and darunavir (DRV)] were introduced into the market almost simultaneously, and salvage regimens containing these three antiretrovirals have been reported to exhibit strong potency against drug-resistant HIV-1 infection. However, the sustainability of such regimens remains unclear, particularly for patients infected with multidrug-resistant viruses. Here we report a case of super-multidrug-resistant HIV-1 infection which has been successfully controlled by novel combination therapy including RAL, ETR, and DRV for over 2 years, indicating that the novel combination could become an ultimate weapon against drug-resistant HIV infection and could alter the landscape of HIV salvage therapy.

Neurocysticercosis case with tuberculoma-like epithelioid granuloma strongly suspected by serology and confirmed by mitochondrial DNA.

An Indian woman with multiple and nodular cerebral lesions presenting epithelioid granulomas was diagnosed as suspected malignant tumours and the biopsy was carried at local hospital in Japan. The specimen was pathologically diagnosed as tuberculoma. However, due to her nationality, the authors suspected it to be neurocysticercosis (NCC) and carried out serology and applied mitochondrial DNA analysis of Taenia solium. These diagnostic tools revealed it as NCC radiologically and pathologically mimicking central nervous tuberculomas. Molecular confirmation of NCC cases is strongly recommended when we can get the biopsy specimens.

Changes in impact of HLA class I allele expression on HIV-1 plasma virus loads at a population level over time.

HLA class I allele types have differential impacts on the level of the pVL and outcome of HIV-1 infection. While accumulations of CTL escape mutations at population levels have been reported, their actual impact on the level of the pVL remains unknown. In this study HLA class I types from 141 untreated, chronically HIV-1 infected Japanese patients diagnosed from 1995-2007 were determined, and the associations between expression of individual HLA alleles and level of pVL analyzed. It was found that the Japanese population has an extremely narrow HLA distribution compared to other ethnic groups, which may facilitate accumulation of CTL escape mutations at the population level. Moreover while they uniquely lack the most protective HLA-B27/B57, they commonly express the alleles that are protective in Caucasians (A11:10.4%, A26:11.55%, B51:8.6% and Cw14:12.7%). Cross-sectional analyses revealed no significant associations between expression of individual alleles and the level of the pVL. The patients were then stratified by the date of HIV diagnosis and the analyses repeated. It was found that, before 2001, B51+ individuals displayed significantly lower pVL than the other patients (median: 5150 vs. 18,000 RNA copies/ml, P=0.048); however thereafter this protective effect waned and disappeared, whereas no changes were observed for any other alleles over time. These results indicate that, at a population level, some HLA alleles have been losing their beneficial effects against HIV disease progression over time, thereby possibly posing a significant challenge for HIV vaccine development. However such detrimental effects may be limited to particular HLA class I alleles.

Whole brain radiation alone produces favourable outcomes for AIDS-related primary central nervous system lymphoma in the HAART era.

Primary central nervous system lymphoma (PCNSL) related to acquired immunodeficiency syndrome (AIDS) is a lethal disorder, but the recent application of highly active antiretroviral therapy (HAART) has significantly improved prognosis. This retrospective cohort study of AIDS-related PCNSL examined the actual clinical outcomes and prognostic variables affecting overall survival (OS) in the HAART era. Twenty-three newly diagnosed AIDS-related PCNSL at 12 regional centre hospitals for HIV/AIDS in Japan between 2002 and 2008 were consecutively enrolled. The estimated 3-yr OS rate of the entire cohort was 64% (95%CI, 41.0-80.3%). Whole brain radiation therapy (WBRT) had an independent positive impact on survival (WBRT >or=30 Gy vs. others, P = 0.02). Nine of 10 patients with a good performance status (PS) (0-2) remained alive with complete response, whereas 10 (77%) of 13 of those with a poor PS (3-4) died mostly after a short period. The estimated 3-yr OS rate of the groups with a good and poor PS was 100% and 38% (95%CI, 14-63%), respectively (P = 0.01). Leukoencephalopathy (grade >or= 2) developed in 21% of those that survived more than 12 months after radiation. The patients receiving a curative intent radiation dose (>or=30 Gy) of WBRT achieved prolonged survival while maintaining a good quality of life in the HAART era, especially among patients with a favourable PS.

Highly restricted T-cell receptor repertoire in the CD8+ T-cell response against an HIV-1 epitope with a stereotypic amino acid substitution.

OBJECTIVE: In peripheral blood mononuclear cells (PBMCs) from HIV-1-positive patients, we sought to identify CD8+ T-cell populations and the corresponding T-cell receptor (TCR) repertoires that react to an immunogenic cytotoxic T lymphocyte (CTL) epitope with or without an escape mutation. METHODS: PBMCs from HLA-A*2402(A24)-positive patients were stimulated with peptides representing a wild-type CTL epitope in the HIV-1 Nef protein [Nef138-10(wt)] or an escape mutant with a Y to F (Y139F) substitution at the second position [Nef138-10(2F)]. Cultured PBMCs were stained with peptide-major histocompatibility complex tetramers containing Nef138-10(wt) or Nef138-10(2F) sequences. After in-vitro stimulation of PBMCs with cognate peptides, the CD8+ T-cell population was sorted into different fractions: positive only to the wild-type tetramer (wt-positive), positive only to the mutant tetramer (2F-positive), and positive to both wt-tetramers and mutant-tetramers (dual-positive). TCR repertoires of sorted epitope-specific CD8+ T-cell populations were determined by sequencing. RESULTS: A 2F-positive population was rarely observed under our culture and staining conditions. The wt-positive CD8+ T-cell populations had a diverse TCR repertoire, but the TCR repertoires in dual-positive CD8+ populations were highly restricted. In the dual-positive CD8+ T-cell populations, most clonotypes used the TRBV4-1 and TRBJ2-7 gene segments for the TCR beta-chain and the TRAV8-3 and TRAJ40-1 for the TCR alpha-chain. The CDR3 region of the TCR beta-chain showed little variation. CONCLUSION: These results provide an example of restricted TCR repertoire in a specific CTL response against the escaping epitope. We speculate that impairment of antigen presentation in escaping viruses may underlie the restricted repertoire.

Unusual radiological findings of Fasciola hepatica infection with huge cystic and multilocular lesions.

This report describes a case of hepatic phase Fasciola hepatica infection presenting huge and multilocular lesions. The unique radiological findings mimicked hydatid diseases and also cystic liver neoplasm. Fascioliasis should be included in the differential diagnosis for cystic liver diseases.

Comparison between Sendai virus and adenovirus vectors to transduce HIV-1 genes into human dendritic cells.

Immuno-genetherapy using dendritic cells (DCs) can be applied to human immunodeficiency virus type 1 (HIV-1) infection. Sendai virus (SeV) has unique features such as cytoplasmic replication and high protein expression as a vector for genetic manipulation. In this study, we compared the efficiency of inducing green fluorescent protein (GFP) and HIV-1 gene expression in human monocyte-derived DCs between SeV and adenovirus (AdV). Human monocyte-derived DCs infected with SeV showed the maximum gene expression 24 hr after infection at a multiplicity of infection (MOI) of 2. Although SeV vector showed higher cytopathic effect on DCs than AdV, SeV vector induced maximum gene expression earlier and at much lower MOI. In terms of cell surface phenotype, both SeV and AdV vectors induced DC maturation. DCs infected with SeV as well as AdV elicited HIV-1 specific T-cell responses detected by interferon gamma (IFN-gamma) enzyme-linked immunospot (Elispot). Our data suggest that SeV could be one of the reliable vectors for immuno-genetherapy for HIV-1 infected patients.

Analysis of HIV-1 sequences before and after co-infecting syphilis.

Increasing syphilis incidence among men who have sex with men (MSM) has been reported. The index case was a human immunodeficiency virus type 1 (HIV-1)-positive MSM who presented coincidentally with the secondary syphilis and a rebound of plasma viral load after complete suppression of HIV-1 (below 50 copies/ml) for 13 months with potent antiretroviral therapy (PART), suggesting a possibility of HIV-1 superinfection. We analyzed HIV-1 sequences before and after syphilis in four HIV-1-positive patients including the index case to explore drug resistance mutations (DRMs) and a possibility of HIV-1 superinfection. There were patients who obtained DRMs around syphilis infection but no evidence of HIV-1 superinfection was obtained. Our results underline the importance of strict adherence to PART.

Peptide-loaded dendritic-cell vaccination followed by treatment interruption for chronic HIV-1 infection: a phase 1 trial.

Immune response enhanced by therapeutic HIV-1 vaccine may control viral proliferation after discontinuation of highly active antiretroviral therapy (HAART). Although which strategies for therapeutic vaccination are feasible remains controversial, application of dendritic cells (DCs) as a vaccine adjuvant represents a promising approach to improving deteriorated immune function in HIV-1-infected individuals. The safety and efficacy of DC-based vaccine loaded with HIV-1-derived cytotoxic T lymphocytes (CTL) peptides were thus investigated in this study. Autologous DCs loaded with seven CTL peptides with HLA-A*2402 restriction were immunized to four HIV-1-infected individuals under HAART. In terms of safety, peptide-loaded DCs were well tolerated, and only mild local and general symptoms were observed during vaccine administration. ELISPOT assays to detect IFN-gamma production in CD8(+) lymphocytes revealed a limited breadth of responses to immunized peptides in two of four participants, but no response in the remaining two participants. Differences in immunological response might be attributable to the fact that responders displayed higher nadir CD4 counts before starting HAART and were immunized with a larger number of DCs per reactive peptide than non-responders. Discontinuation of HAART after vaccination failed to lower viral set points compared to those before starting HAART. This early outcome warrants further exploration to elucidate the therapeutic value of vaccination with DCs in HIV-1 infection.

Clinical characteristics of imported malaria in Japan: analysis at a referral hospital.

Imported malaria remains an important problem in Japan. We have reviewed the medical records of 170 cases of malaria in our hospital, which corresponds to 14.9% of the total cases in Japan. The predominant malarial species was Plasmodium falciparum (52.3%), and the most frequent area of acquisition was Africa (54.2%), followed by Asia (20.9%) and Oceania (19.6%). The most common reason for travel among Japanese patients was business. A significant proportion (22.2%) of vivax malaria cases experienced relapse despite standard primaquine therapy. Most primaquine failures were from Oceania. We also found that a substantial number of Japanese patients contracted malaria without chemoprophylaxis and consulted medical facilities with an unfavorably long delay from initial symptoms (median: 3.0 days). Direct education of travelers and travel companies, in addition to health care providers, is likely necessary to improve outcomes of imported malaria.