Kiyohiko Hatake

Blockade of bulky lymphoma‐associated CD55 expression by RNA interference overcomes resistance to complement‐dependent cytotoxicity with rituximab

Recently, anti‐CD20 (rituximab) and anti‐Her2/neu (trastuzumab) antibodies have been developed and applied to the treatment of malignant lymphoma and breast cancer, respectively. However, bulky lymphoma is known to be resistant to rituximab therapy, and this needs to be overcome. Fresh lymphoma cells were collected from 30 patients with non‐Hodgkins lymphoma, the expression of CD20 and CD55 was examined by flow cytometry, and complement‐dependent cytotoxicity (CDC) assays were carried out. Susceptibility to CDC with rituximab was decreased in a tumor size‐dependent manner (r = –0.895, P < 0.0001), but not in a CD20‐dependent manner (r = –0.076, P = 0.6807) using clinical samples. One complement‐inhibitory protein, CD55, contributed to bulky lymphoma‐related resistance to CDC with rituximab. A decrease in susceptibility to CDC with rituximab was statistically dependent on CD55 expression (r = –0.927, P < 0.0001) and the relationship between tumor size and CD55 expression showed a significant positive correlation (r = 0.921, P < 0.0001) using clinical samples. To overcome the resistance to rituximab by high expression of CD55 in bulky lymphoma masses, small interfering RNA (siRNA) was designed from the DNA sequence corresponding to nucleic acids 1–380 of the CD55 cDNA. Introduction of this siRNA decreased CD55 expression in the breast cancer cell line SK‐BR3 and in CD20‐positive cells of patients with recurrent lymphoma; resistance to CDC was also inhibited. This observation gives us a novel strategy to suppress bulky disease‐related resistance to monoclonal antibody treatment. (Cancer Sci 2006; 97: 72–79)

Galectin-9 exhibits anti-myeloma activity through JNK and p38 MAP kinase pathways

Galectins constitute a family of lectins that specifically exhibit the affinity for β-galactosides and modulate various biological events. Galectin-9 is a tandem-repeat type galectin with two carbohydrate recognition domains and has recently been shown to have an anti-proliferative effect on cancer cells. We investigated the effect of recombinant protease-resistant galectin-9 (hGal9) on multiple myeloma (MM). In vitro, hGal9 inhibited the cell proliferation of five myeloma cell lines examined, including a bortezomib-resistant subcell line, with IC50 between 75.1 and 280.0u2009nM, and this effect was mediated by the induction of apoptosis with the activation of caspase-8, -9, and -3. hGal9-activated Jun NH2-terminal kinase (JNK) and p38 MAPK signaling pathways followed by H2AX phosphorylation. Importantly, the inhibition of either JNK or p38 MAPK partly inhibited the anti-proliferative effect of hGal9, indicating the crucial role of these pathways in the anti-MM effect of hGal9. hGal9 also induced cell death in patient-derived myeloma cells, some with poor-risk factors, such as chromosomal deletion of 13q or translocation t(4;14)(p16;q32). Finally, hGal9 potently inhibited the growth of human myeloma cells xenografted in nude mice. These suggest that hGal9 is a new therapeutic target for MM that may overcome resistance to conventional chemotherapy.

CD5 expression is potentially predictive of poor outcome among biomarkers in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP therapy

BACKGROUNDnSeveral biomarkers indicating poor prognosis have been reassessed in patients receiving rituximab combination chemotherapy for diffuse large B-cell lymphoma (DLBCL). However, few studies have investigated outcome in relation to a combination of these biomarkers. In addition, no large-scale studies have reassessed the outcome of patients with CD5-positive DLBCL treated with rituximab.nnnPATIENTS AND METHODSnWe conducted a retrospective study and investigated the predictive value of three biomarkers -- BCL2, germinal center (GC) phenotype and CD5 -- in 121 DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone.nnnRESULTSnCD5-positive patients showed significantly poorer event-free survival (EFS) and overall survival (OS) than CD5-negative patients (2-year EFS, 18% versus 73%, P < 0.001; 2-year OS, 45% versus 91%, P = 0.001). However, no significant difference in outcome according to BCL2 or GC phenotype was observed. Multivariate analysis revealed that CD5 expression was a significant prognostic factor for EFS [hazard ratio 14.2, 95% confidence interval (CI) 4.7-43.2] and OS (hazard ratio 20.3, 95% CI 3.6-114.4).nnnCONCLUSIONSnCD5 expression was the only significant prognostic factor among the biomarkers examined in this study. Further studies with larger numbers are warranted to confirm the prognostic significance of CD5 expression for patients with DLBCL receiving rituximab-containing chemotherapy.

Increased incidence of interstitial pneumonia by CHOP combined with rituximab

Several authors have reported interstitial pneumonia (IP) during rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy, while others have encountered Pneumocystis jirovecii pneumonia during rituximab-combined bi-weekly CHOP. Herein, we report that 13 of 90 (14%) patients developed IP during R-CHOP therapy, compared with none of 105 patients treated with CHOP alone as a historical control. There were no differences in baseline data between patients undergoing the two therapies. Among R-CHOP-treated patients, serum β-d-glucan was increased in 8 of 12 (75%) IP patients compared with none of 30 non-IP patients examined. In five IP patients who underwent sputum evaluation, two were positive for P. jirovecii by the polymerase chain reaction and another two were positive for Candida albicans. No other organisms were detected as causative pathogens. Treatment with steroids, sulfamethoxazole-trimethoprim (ST), and antifungals was effective. Our results suggest that R-CHOP raises the incidence of IP, possibly through increasing the susceptibility to P. jirovecii and fungal infection. The need for prophylactic antifungals and ST during R-CHOP should be evaluated by randomized controlled trials.

Soluble interleukin-2 receptor retains prognostic value in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP (RCHOP) therapy

BACKGROUNDnSoluble interleukin-2 receptor (SIL-2R) is known to be a prognostic parameter in patients with diffuse large B-cell lymphoma (DLBCL) receiving cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) therapy. However, its prognostic value has not been well known since the introduction of rituximab.nnnPATIENTS AND METHODSnWe retrospectively evaluated the prognostic impact of SIL-2R in 228 DLBCL patients, comparing 141 rituximab-combined CHOP (RCHOP)-treated patients with 87 CHOP-treated patients as a historical control.nnnRESULTSnPatients with high serum SIL-2R showed significantly poorer event-free survival (EFS) and overall survival (OS) than patients with low SIL-2R in both the RCHOP group (2-year EFS, 66% versus 92%, P<0.001; OS, 82% versus 95%, P=0.005) and the CHOP group (2-year EFS, 40% versus 82%; OS, 61% versus 90%, both P<0.001). Multivariate analysis including the five parameters of International Prognostic Index (IPI) and two-categorized IPI revealed that SIL-2R was an independent prognostic factor for EFS and OS in the RCHOP group as well as in the CHOP group.nnnCONCLUSIONSnOur results demonstrate that SIL-2R retains its prognostic value in the rituximab era. The prognostic value of SIL-2R in DLBCL patients receiving rituximab-combined chemotherapy should be reassessed on a larger scale and by long-term follow-up.

Element Array by Scanning X-ray Fluorescence Microscopy after Cis-Diamminedichloro-Platinum(II) Treatment

Minerals are important for cellular functions, such as transcription and enzyme activity, and are also involved in the metabolism of anticancer chemotherapeutic compounds. Profiling of intracellular elements in individual cells could help in understanding the mechanism of drug resistance in tumors and possibly provide a new strategy of anticancer chemotherapy. Using a recently developed technique of scanning X-ray fluorescence microscopy (SXFM), we analyzed intracellular elements after treatment with cis-diamminedichloro-platinum(II) (CDDP), a platinum-based anticancer agent. The images obtained by SXFM (element array) revealed that the average Pt content of CDDP-resistant cells was 2.6 times less than that of sensitive cells, and the zinc content was inversely correlated with the intracellular Pt content. Data suggested that Zn-related detoxification is responsible for resistance to CDDP. Of Zn-related excretion factors, glutathione was highly correlated with the amount of Zn. The combined treatment of CDDP and a Zn(II) chelator resulted in the incorporation of thrice more Pt with the concomitant down-regulation of glutathione. We propose that the generation of an element array by SXFM opens up new avenues in cancer biology and treatment.

Identification of CD20 C-Terminal Deletion Mutations Associated with Loss of CD20 Expression in Non-Hodgkin's Lymphoma

Purpose: Rituximab is commonly incorporated into CD20-positive B-cell lymphoma therapy to improve response and prognosis. With increasing use, resistance to rituximab is a continuing concern, but CD20 mutation as a cause of resistance has not previously been reported. Experimental Design: Freshly collected lymphoma cells from 50 patients with previously untreated or relapsed/resistant non-Hodgkins B-cell lymphomas (diffuse large B cell, n = 22; follicular, n = 7; mucosa associated lymphoid tissue, n = 16; chronic lymphocytic leukemia, n = 2; small lymphocytic lymphoma, n = 1; lymphoplasmacytic, n = 1; mantle cell lymphoma, n = 1) were assessed for CD20 expression by flow cytometry, and CD20 gene sequencing was done on extracted DNA. Results: CD20 mutations were found in 11 (22.0%) of 50 patients and could be grouped as C-terminal deletion (8.0%), early termination (10.0%), and extracellular domain (2.0%) or transmembrane domain (2.0%) mutations. The mean fluorescence intensity of CD20 on fresh lymphoma cells was significantly lower for the C-terminal deletion mutation [3.26; 95% confidence interval (95% CI), 0.09-6.89] compared with wild type (30.8; 95% CI, 22.4-39.2; P < 0.05). In contrast, early termination mutations did not show significant differences in CD20 expression compared with wild type (19.5; 95% CI, 10.7-28.4; P > 0.05). Conclusions: It is possible that C-terminal deletion mutations of CD20 may be related to relapse/resistance after rituximab therapy. These mutations should be examined in patients showing progression of disease after partial remission.

Irinotecan plus cisplatin for therapy of small-cell carcinoma of the esophagus: report of 12 cases from single institution experience.

BACKGROUNDnEsophageal small-cell cancer is a rare disease, and standard therapy has not yet been established.nnnMETHODSnA total of 12 esophageal small-cell carcinoma patients were treated with CPT-11 (70 mg/m(2)) on Days 1 and 15 and CPT-11 plus CDDP (80 mg/m(2)) on Day 1 with each cycle repeated every 4 weeks at our institution.nnnRESULTSnA total of 46 chemotherapy courses were given (median, 3.5). There were two complete responses and eight partial responses. The median survival time was 417 (97-1626) days, and three patients were still alive for >40 months. Grade 4 neutropenia was observed in two patients, Grade 4 anemia in one patient, Grade 3-4 diarrhea in three patients and Grade 3-4 hyponatremia in three patients. Other adverse reactions seen were mild with no treatment-related deaths observed.nnnCONCLUSIONSnTo our knowledge, this is the first report of the series of more than 10 patients with small-cell carcinoma of the esophagus treated with the same chemotherapy regimen. The combination of CPT-11 and CDDP appears to be effective therapy of this disease with acceptable toxicity profile. We believe that this regimen is one of the options to be considered for treatment of esophageal small-cell carcinoma.

Functional in vivo optical imaging of tumor angiogenesis, growth, and metastasis prevented by administration of anti-human VEGF antibody in xenograft model of human fibrosarcoma HT1080 cells

Angiogenesis plays a crucial role in cancer progression and metastasis. Thus, blocking tumor angiogenesis is potentially a universal approach to prevent tumor establishment and metastasis. In this study, we used in vivo and ex vivo fluorescence imaging to show that an antihuman vascular endothelial growth factor (VEGF) antibody represses angiogenesis and the growth of primary tumors of human fibrosarcoma HT1080 cells in implanted nude mice. Interestingly, administering the antihuman VEGF antibody reduced the development of new blood vessels and normalized pre‐existing tumor vasculature in HT1080 cell tumors. In addition, antihuman VEGF antibody treatment decreased lung metastasis from the primary tumor, whereas it failed to block lung metastasis in a lung colonization experiment in which tumor cells were injected into the tail vein. These results suggest that VEGF produced by primary HT1080 cell tumors has a crucial effect on lung metastasis. The present study indicates that the in vivo fluorescent microscopy system will be useful to investigate the biology of angiogenesis and test the effectiveness of angiogenesis inhibitors. (Cancer Sci 2009)

Serum level of macrophage colony‐stimulating factor is increased in prostate cancer patients with bone metastasis

Recent evaluation of human prostate tissues has shown predominantly high expression of the macrophage colony-stimulating factor receptor in prostatic intra-epithelial neoplasia or prostate cancer. However, the expression of its ligand, the macrophage colony-stimulating factor (M-CSF), and the biological role of this signaling in prostate cancer has not been analyzed. In this research we determined the relationship of serum M-CSF level to clinical parameters of prostate cancer progression. We measured the serum level of M-CSF in 170 patients with histologically confirmed prostatic adenocarcinoma and in 54 patients in whom prostate cancer was not detected. We also investigated the M-CSF expression in prostate cancer tissues by immunohistochemistry. The serum levels of M-CSF in bone metastatic prostate cancer patients was significantly higher than those in non-metastatic patients, while M-CSF did not differ with regards to histological grade, Gleason score or local tumor progression. M-CSF expression was detected in prostate cancer cells themselves by immunohistochemistry. These results suggest that M-CSF may have a functional role in prostate cancer progression.