Akihisa Yao

Phase I trial of patient‐oriented vaccination in HLA‐A2‐positive patients with metastatic hormone‐refractory prostate cancer

To evaluate the safety and toxicity of peptide vaccination for patients with metastatic hormone‐refractory prostate cancer (HRPC) based on pre‐existing peptide‐specific cytotoxic T‐lymphocyte (CTL) precursors in the circulation, 10 patients positive for human leukocyte antigen (HLA)‐A2 with metastatic HRPC were enrolled in a phase I study. Peptide‐specific CTL‐precursors reactive to 16 kinds of vaccine candidates in the pre‐vaccination peripheral blood mononuclear cells (PBMCs) were measured, and patients were followed by vaccination with only positive peptides (up to 4 kinds of peptides). Serum prostate‐specific antigen (PSA) levels were monitored regularly. The peptide vaccination was safe and well tolerated with no major adverse effects. The most common toxicities were dermatologic reactions at the injection site. Increased CTL response to peptides was observed in 4 of 10 patients. Anti‐peptide IgG was also detected in post‐vaccination sera of 7 of 10 patients. One patient showed the disappearance of a pelvic bone metastasis after five vaccinations. Three patients showed a decrease of serum PSA level from the baseline after the vaccination, but no patients showed a serum PSA level decrease of ∼50%. The median survival duration of study patients was 22 months with follow‐up from 3 to 27 months. We consider that the increase in cellular and humoral immune responses, and decrease in PSA level in some patients justify further development of peptide vaccination for metastatic HRPC patients. (Cancer Sci 2004; 95: 77–84)

Surgical management of the urinary tract in patients with locally advanced colorectal cancer.

OBJECTIVES To review cases of colorectal cancer requiring urologic management to clarify the role the urologist should play in the surgical procedures. A deterrent to radical surgery for advanced colorectal carcinoma with urinary involvement is the technical complexity and associated morbidity and mortality of this procedure. METHODS Thirty-six tumors in 35 patients, including 19 sigmoid cancers (Stage II, 17; Stage III, 2), 12 rectal cancers (Stage II, 11; Stage III, 1), and 5 local recurrences of colorectal carcinoma in the pelvis were reviewed. All tumors had invaded the bladder, prostate, or ureter. The demographic and clinical characteristics, type of operative procedure, and postoperative complications were analyzed. RESULTS Of the patients with a sigmoid tumor, partial cystectomy was performed in 15 patients who underwent a bladder-sparing procedure; an ileal conduit and ileal neobladder were created in 2 patients each who required cystectomy. Four patients with rectal cancer underwent a bladder-sparing procedure: partial cystectomy in 1, partial cystectomy with ileal ureter in 1, and prostatectomy in 2. The remaining 8 patients underwent cystectomy with the following types of reconstruction: colonic neobladder in 1, ileal neobladder in 4, Indiana pouch in 1, ileal conduit in 1, and ureterocutaneostomy in 1 patient. The bladder was spared in a greater percentage of patients with sigmoid cancer than in those with rectal cancer. The incidence of complications was greater in patients with rectal cancer and local recurrence than in those with sigmoid tumors. The complication rate was especially low in patients who underwent a bladder-sparing procedure (10.5%) compared with patients who required cystectomy (58.3%). The survival in patients with sigmoid cancer who underwent bladder-sparing surgery also was better than in those who underwent cystectomy. CONCLUSIONS The treatment of advanced colorectal cancer is best managed by a committed team that includes an experienced urologist. Urologists play a critical role in determining the surgical options and creating appropriate urinary diversions to achieve curative resection with the highest quality of life.

Identification of Peptide Vaccine Candidates for Prostate Cancer Patients with HLA-A3 Supertype Alleles

Purpose: The peptide vaccine candidates identified to date have been focused on the HLA-A2 and HLA-A24 alleles. The HLA-A11, HLA-A31, and HLA-A33 alleles share binding motifs and belong to an HLA-A3 supertype family. In this study, we attempted to identify CTL-directed peptide candidates, derived from prostate-related antigens and shared by HLA-A11+, HLA-A31+, and HLA-A33+ prostate cancer patients. Experimental Design: Based on the binding motif to the HLA-A3 supertype alleles, 42 peptides were prepared from prostate-specific antigen (PSA), prostate-specific membrane antigen (PSMA), and prostatic acid phosphatase (PAP). These peptides were first screened for their ability to be recognized by immunoglobulin G (IgG) of prostate cancer patients and subsequently for the potential to induce peptide-specific and prostate cancer–reactive CTLs from peripheral blood mononuclear cells (PBMC) of cancer patients with the HLA-A11, HLA-A31, and HLA-A33 alleles. Results: Five peptide candidates, including the PSA16-24, PAP155-163, PAP248-257, PSMA207-215, and PSMA431-440 peptides, were frequently recognized by IgGs of prostate cancer patients. These peptides efficiently induced peptide-specific and prostate cancer–reactive CTLs from PBMCs of cancer patients with the HLA-A11, HLA-A31, and HLA-A33 alleles. Antibody blocking and cold inhibition experiments revealed that the HLA-A3 supertype–restricted cytotoxicity against prostate cancer cells could be ascribed to peptide-specific and CD8+ T cells. Conclusions: We identified prostate-related antigen-derived new peptide candidates for HLA-A11-, HLA-A31-, and HLA-A33-positive prostate cancer patients. This information could facilitate the development of a peptide-based anticancer vaccine for patients with alleles other than HLA-A2 and HLA-A24.

Ran, a Small GTPase Gene, Encodes Cytotoxic T Lymphocyte (CTL) Epitopes Capable of Inducing HLA-A33–restricted and Tumor-Reactive CTLs in Cancer Patients

Purpose: The purpose is to identify a gene coding for tumor-associated antigen and peptide capable of inducing CTLs reactive to tumor cells with a HLA-A33–restricted fashion to provide scientific basis for specific immunotherapy to HLA-A33+ cancer patients. Experimental Design: An expression gene-cloning method was used to identify the tumor-associated antigen gene. Northern blot analysis and immunohistochemistry were used to examine the mRNA and protein expression levels in various cells and tissues, respectively. Synthetic peptides were examined for their ability to induce HLA-A33+ tumor-reactive CTLs in peripheral blood mononuclear cells from cancer patients. Result: A gene of small GTPase, Ran, which controls the cell cycle through the regulation of nucleocytoplasmic transport, mitotic spindle organization, and nuclear envelope formation, was found to encode epitopes recognized by the HLA-A33–restricted CTLs established from T cells infiltrating into gastric adenocarcinoma. The expression of the Ran gene was increased in most cancer cell lines and cancer tissues at both the mRNA and protein levels. However, it was not enhanced in the surrounding normal cells or tissues. It was also undetectable in normal tissues as far as tested. Ran-derived peptides at positions 48–56 and 87–95 could induce CD8+ peptide-specific CTLs reactive to tumor cells from HLA-A33+ epithelial cancer patients in a HLA class I-restricted manner. Conclusions: Because of its increased expression in cancer cells and involvement in malignant transformation and/or the enhanced proliferation of cancer cells, the two Ran-directed peptides could be potent candidates in use for specific immunotherapy against HLA-A33+ epithelial cancers.

Identification of parathyroid hormone-related protein-derived peptides immunogenic in human histocompatibility leukocyte antigen-A24+ prostate cancer patients.

Parathyroid hormone-related protein (PTHrP) is a key factor in the development of bone metastases, which are a major barrier in treating prostate cancer patients. In this study, we attempted to identify PTHrP-derived peptides immunogenic in human histocompatibility leukocyte antigen (HLA)-A24+ prostate cancer patients. Among four different PTHrP peptides carrying the HLA-A24 binding motif, both the PTHrP36–44 and PTHrP102–111 peptides efficiently induced peptide-specific cytotoxic T lymphocytes from peripheral blood mononuclear cells (PBMCs) of HLA-A24+ prostate cancer patients. Peptide-stimulated PBMCs showed cytotoxicity against prostate cancer cells in an HLA-A24-restricted manner. Experiments using antibodies and cold inhibition targets confirmed that their cytotoxicity was dependent on PTHrP peptide-specific and CD8+ T cells. Immunoglobulin G reactive to the PTHrP102–111 or PTHrP110–119 peptide was frequently detected in the plasma of prostate cancer patients, suggesting that the PTHrP102–111 peptide is able to elicit cellular and humoral immune responses in cancer patients. These results indicate that the PTHrP could be a promising target molecule for specific immunotherapy of HLA-A24+ prostate cancer patients with metastases.

The significant immunological characteristics of peripheral blood neutrophil-to-lymphocyte ratio and Fas ligand expression incidence in nephrectomized tumor in late recurrence from renal cell carcinoma

OBJECTIVE In order to characterize the significance of immune system function in patients with advanced renal cell carcinoma (RCC), we investigated the interactive relationships among the following parameters: metastatic characteristics, expression of Fas ligand (FasL) in nephrectomized specimens, immunological parameters, and patients prognosis. MATERIALS AND METHODS Thirty-five patients with advanced RCC were stratified into 3 groups according to the characteristics of metastasis timing, at first presentation (mFP), within 5 years of nephrectomy (early-recurrence), after 5 years (late-recurrence). Immunological parameters [hemoglobin, lymphocyte count, neutrophil/lymphocyte ratio (NLR), serum albumin, Eastern Cooperative Oncology Group (ECOG) performance status (PS), and Charlson Comorbidity Index], FasL expression in RCC, and patient prognosis from occurrence of metastasis were compared among the groups. Thirty-five patients were also stratified into 2 groups according to FasL positivity and individual parameters. Patients prognosis and the remaining immunological parameters were compared between groups. RESULTS The NLRs of the late-recurrence group were significantly lower than those of the mFP (P = 0.0004) and early-recurrence (P = 0.013) groups. The FasL mRNA positivity of the late-recurrence group was significantly lower than those of the mFP (P = 0.001) and early-recurrence (P = 0.0277) groups. The prognosis of the late-recurrence group was significantly better than that of the early-recurrence group (P = 0.0255). NLRs were significantly lower in the FasL-negative group than in the -positive group (P = 0.0182). The cause-specific survival rates of the ECOG PS 0 group were significantly higher than that of the ECOG PS > 0 group (P < 0.0001). CONCLUSIONS Our results suggest the associations of the prognosis in advanced RCC with peripheral blood NLR and FasL expression in nephrectomized tumor. The characteristics of lower values of NLR and FasL expression positivity in late-recurrence compared with other metastatic timings suggest strong host immune activity, and may imply relatively long survival. On the other hand, elucidation of the patients general condition obtained not only by chemical data but also by ECOG PS is crucial in the management of patients with advanced RCC.

Vaccination of cytotoxic T lymphocyte-directed peptides elicited and spread humoral and Th1-type immune responses to prostate-specific antigen protein in a prostate cancer patient.

The authors studied humoral and CD4+ T-cell responses in an HLA-A24+ prostate cancer patient vaccinated with cytotoxic T lymphocyte (CTL)-directed peptides, including a prostate-specific antigen (PSA)248-257 peptide, to understand what kinds of immune responses are elicited in peptide-vaccinated patients. The levels of immunoglobulin G (IgG) reactive to the administered PSA248-257 peptide or the PSA protein were kinetically examined. The level of IgG reactive to the PSA248-257 peptide drastically increased after the peptide vaccination, with a peak after the seventh vaccination, whereas that of IgG reactive to the PSA protein continued to increase throughout the vaccination period. IgG reactive to the PSA protein after the 13th vaccination showed no reactivity to the administered PSA peptides. However, HLA-DRB1*1302-restricted and PSA protein-recognizing TH1-type CD4+ T-cell clone and line, with different specificity, were successfully established from the post-7th and post-13th peripheral blood mononuclear cells, respectively. Both CD4+ T cells produced interferon-γ in response to naturally processed PSA secreted from prostate cancer cells, whereas their reactivity to the administered PSA248-257 peptide was undetectable or negligible. These findings indicate that vaccination with CTL-directed peptides, including a PSA-derived peptide, was able to elicit and spread humoral and TH1-type immune responses to the PSA protein.

Prognostic impact of preoperative hematological disorders and a risk stratification model in bladder cancer patients treated with radical cystectomy.

The present study investigated prognostic indicators, including clinicopathological and preoperative hematological factors, and developed a prognostic factor‐based risk stratification model in bladder cancer patients treated with radical cystectomy.

Fas expression in renal cell carcinoma accurately predicts patient survival after radical nephrectomy.

Objectives: To investigate Fas, Fas ligand (FasL) and Bcl-2 expression, which are considered to be important apoptotic regulatory factors in renal cell carcinomas (RCCs). Patients and Methods: mRNA quantification and immunohistochemistry allowed for the determination of the expression of these three factors in surgically resected tumors from 82 patients with RCC. The correlation of protein and gene expression with more than 10 years of survival data following nephrectomy (along with clinical and pathologic parameters) was analyzed using uni- and multivariate statistical models. Results: A significantly poorer outcome was observed in patients with tumors expressing high levels of Fas mRNA in the multivariate analysis (p = 0.0002). In addition, patient survival was significantly worse in FasL mRNA-positive tumor cases when compared with FasL mRNA-negative cases (p = 0.0345). Ten cases relapsed more than 5 years after nephrectomy. Among them, the tumors of 8 cases (80%) did not express FasL mRNA. Analysis of Bcl-2 did not show statistical significance of Bcl-2 expression as a prognostic indicator. Conclusions: The data suggest that pronounced Fas expression is a surrogate biomarker of active cancer cell proliferation. Given the FasL tumor counterattack theory, FasL overexpression in RCC may be one of the host immune deficiencies, consequently leading to poor prognosis.

High neutrophil‐to‐lymphocyte ratio predicts poor clinical outcome in patients with castration‐resistant prostate cancer treated with docetaxel chemotherapy

To evaluate the prognostic significance of the neutrophil‐to‐lymphocyte ratio in patients receiving chemotherapy with docetaxel for castration‐resistant prostate cancer.