Mitsugu Kanehira

Predicting Response to Methotrexate, Vinblastine, Doxorubicin, and Cisplatin Neoadjuvant Chemotherapy for Bladder Cancers through Genome-Wide Gene Expression Profiling

Purpose: Neoadjuvant chemotherapy for invasive bladder cancer, involving a regimen of methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC), can improve the resectability of larger neoplasms for some patients and offer a better prognosis. However, some suffer severe adverse drug reactions without any effect, and no method yet exists for predicting the response of an individual patient to chemotherapy. Our purpose in this study is to establish a method for predicting response to the M-VAC therapy. Experimental Design: We analyzed gene expression profiles of biopsy materials from 27 invasive bladder cancers using a cDNA microarray consisting of 27,648 genes, after populations of cancer cells had been purified by laser microbeam microdissection. Results: We identified dozens of genes that were expressed differently between nine “responder” and nine “nonresponder” tumors; from that list we selected the 14 “predictive” genes that showed the most significant differences and devised a numerical prediction scoring system that clearly separated the responder group from the nonresponder group. This system accurately predicted the drug responses of 8 of 9 test cases that were reserved from the original 27 cases. Because real-time reverse transcription–PCR data were highly concordant with the cDNA microarray data for those 14 genes, we developed a quantitative reverse transcription–PCR–based prediction system that could be feasible for routine clinical use. Conclusions: Our results suggest that the sensitivity of an invasive bladder cancer to the M-VAC neoadjuvant chemotherapy can be predicted by expression patterns in this set of genes, a step toward achievement of “personalized therapy” for treatment of this disease.

Oncogenic Role of MPHOSPH1, a Cancer-Testis Antigen Specific to Human Bladder Cancer

To disclose the molecular mechanism of bladder cancer, the second most common genitourinary tumor, we had previously done genome-wide expression profile analysis of 26 bladder cancers by means of cDNA microarray representing 27,648 genes. Among genes that were significantly up-regulated in the majority of bladder cancers, we here report identification of M-phase phosphoprotein 1 (MPHOSPH1) as a candidate molecule for drug development for bladder cancer. Northern blot analyses using mRNAs of normal human organs and cancer cell lines indicated this molecule to be a novel cancer-testis antigen. Introduction of MPHOSPH1 into NIH3T3 cells significantly enhanced cell growth at in vitro and in vivo conditions. We subsequently found an interaction between MPHOSPH1 and protein regulator of cytokinesis 1 (PRC1), which was also up-regulated in bladder cancer cells. Immunocytochemical analysis revealed colocalization of endogenous MPHOSPH1 and PRC1 proteins in bladder cancer cells. Interestingly, knockdown of either MPHOSPH1 or PRC1 expression with specific small interfering RNAs caused a significant increase of multinuclear cells and subsequent cell death of bladder cancer cells. Our results imply that the MPHOSPH1/PRC1 complex is likely to play a crucial role in bladder carcinogenesis and that inhibition of the MPHOSPH1/PRC1 expression or their interaction should be novel therapeutic targets for bladder cancers. [Cancer Res 2007;67(7):3276–85]

Involvement of upregulation of DEPDC1 (DEP domain containing 1) in bladder carcinogenesis

In an attempt to disclose mechanisms of bladder carcinogenesis and discover novel target molecules for development of treatment, we applied a cDNA microarray to screen genes that were significantly transactivated in bladder cancer cells. Among the upregulated genes, we here focused on a novel gene, (DEPDC1) DEP domain containing 1, whose overexpression was confirmed by northern blot and immunohistochemical analyses. Immunocytochemical staining analysis detected strong staining of endogenous DEPDC1 protein in the nucleus of bladder cancer cells. Since DEPDC1 expression was hardly detectable in any of 24 normal human tissues we examined except the testis, we considered this gene-product to be a novel cancer/testis antigen. Suppression of DEPDC1 expression with small-interfering RNA significantly inhibited growth of bladder cancer cells. Taken together, these findings suggest that DEPDC1 might play an essential role in the growth of bladder cancer cells, and would be a promising molecular-target for novel therapeutic drugs or cancer peptide-vaccine to bladder cancers.

Validation study of the prediction system for clinical response of M-VAC neoadjuvant chemotherapy

To predict the efficacy of the M‐VAC neoadjuvant chemotherapy for invasive bladder cancers, we previously established the method to calculate the prediction score on the basis of expression profiles of 14 predictive genes. This scoring system had clearly distinguished the responder group from the non‐responder group. To further validate the clinical significance of the system, we applied it to 22 additional cases of bladder cancer patients and found that the scoring system correctly predicted clinical response for 19 of the 22 test cases. The group of patients with positive predictive scores had significantly longer survival than that with negative scores. When we compared our results with a previous report describing the prognosis of the patients with cystectomy alone, the results imply that patients with positive scores are likely to benefit from M‐VAC neoadjuvant chemotherapy, but that the chemotherapy would shorten the lives of patients with negative scores. We are confident that our prediction system to M‐VAC therapy should provide opportunities for achieving better prognosis and improving the quality of life of patients. Taken together, our data suggest that the goal of ‘personalized medicine’, prescribing the appropriate treatment regimen for each patient, may be achievable by selecting specific sets of genes for their predictive values according to the approach shown here. (Cancer Sci 2007; 98: 113–117)

Cancer Peptide Vaccine Therapy Developed from Oncoantigens Identified through Genome-wide Expression Profile Analysis for Bladder Cancer

OBJECTIVE The field of cancer vaccine therapy is currently expected to become the fourth option in the treatment of cancer after surgery, chemotherapy and radiation therapy. We developed a novel cancer peptide vaccine therapy for bladder cancer through a genome-wide expression profile analysis. METHODS Among a number of oncoproteins that are transactivated in cancer cells, we focused on M phase phosphoprotein 1 and DEP domain containing 1, both of which are cancer-testis antigens playing critical roles in the growth of bladder cancer cells, as candidate molecules for the development of drugs for bladder cancer. In an attempt to identify the peptide epitope from these oncoantigens, we conducted a clinical trial using these peptides for patients with advanced bladder cancer. RESULTS We identified HLA-A24-restricted peptide epitopes corresponding to parts of M phase phosphoprotein 1 and DEP domain containing 1 proteins, which could induce peptide-specific cytotoxic T lymphocytes. Using these peptides, we found that M phase phosphoprotein 1- and DEP domain containing 1-derived peptide vaccines could be well tolerated without any serious adverse events, and effectively induced peptide-specific cytotoxic T lymphocytes in vivo. CONCLUSIONS The novel approach adopted in the treatment with peptide vaccines is considered to be a promising therapy for bladder cancer.

Cell-Permeable Peptide DEPDC1-ZNF224 Interferes with Transcriptional Repression and Oncogenicity in Bladder Cancer Cells

Bladder cancer is the second most common genitourinary cancer worldwide, yet its oncogenic origins remain poorly understood. The cancer-testis antigen DEPDC1 was shown recently to contribute to bladder cancer oncogenesis. In this study, we examined the biological functions of DEPDC1 and defined a potential therapeutic strategy to target this molecule. Coimmunoprecipitation and immunocytochemistry revealed that DEPDC1 interacted and colocalized with zinc finger transcription factor ZNF224, a known transcriptional repressor. Inhibiting this interaction with a cell-permeable peptide corresponding to the ZNF224-interacting domain in DEPDC1 induced apoptosis of bladder cancer cells in vitro and in vivo. By inhibiting DEPDC1-ZNF224 complex formation, this peptide triggered transcriptional activation of A20, a potent inhibitor of the NF-kappaB signaling pathway. Our findings indicate that the DEPDC1-ZNF224 complex is likely to play a critical role in bladder carcinogenesis.

Phase I clinical trial of cell division associated 1 (CDCA1) peptide vaccination for castration resistant prostate cancer

Cell division associated 1 (CDCA1) was screened as an oncogene that is overexpressed on several cancers, including prostate cancer. A highly immunogenic HLA‐A*2402‐restricted epitope peptide corresponding to part of the CDCA1 protein was also identified. A phase I clinical trial was conducted for patients with castration resistant prostate cancer (CRPC) using a CDCA1 peptide vaccination. Twelve patients having HLA‐A*2402 with CRPC after failure of docetaxel chemotherapy were enrolled. They received subcutaneous administration of the CDCA1 peptide as an emulsion with Montanide ISA51VG once a week in a dose‐escalation manner (doses of 1.0 or 3.0 mg/body, six patients received each dose). The primary endpoint was safety, and the secondary endpoints were the immunological and clinical responses. Vaccination with CDCA1 peptide was well tolerated without any serious adverse events. Peptide‐specific cytotoxic T lymphocyte (CTL) responses using ELISPOT assay and dextramer assay were observed in three patients receiving the 1.0 mg dose and five patients receiving the 3.0 mg dose. The median overall survival time was 11.0 months and specific CTL reacting to CDCA1 peptide were recognized in long‐surviving patients. CDCA1‐derived peptide vaccine treatment was tolerable and might effectively induce peptide‐specific CTLs for CRPC patients. This novel peptide vaccine therapy for CRPC appears promising. (ClinicalTrials.gov number, NCT01225471).

Recent progress in immunotherapy for urological cancer

Cancer immunotherapy for urological tumors had made progress for several decades, but recent advances in immunotherapy, as therapeutic vaccines or immune checkpoint inhibitors, have drastically changed the present treatment strategy. Recently, nivolumab and atezolizumab have been approved by the Food and Drug Administration for treatment of urological cancers. Additional immune checkpoint inhibitors and vaccines are being tested in clinical trials. Despite advances in these therapeutic modalities, benefits are limited to a subset of patients. New agents and novel combinations will also continue to create new immunotherapy strategies. Further development of biomarkers for predicting response is required to achieve optimal efficacy with these therapeutic interventions.

Present status and future perspective of peptide‐based vaccine therapy for urological cancer

Use of peptide‐based vaccines as therapeutics aims to elicit immune responses through antigenic epitopes derived from tumor antigens. Peptide‐based vaccines are easily synthesized and lack significant side‐effects when given in vivo. Peptide‐based vaccine therapy against several cancers including urological cancers has made progress for several decades, but there is no worldwide approved peptide vaccine. Peptide vaccines were also shown to induce a high frequency of immune response in patients accompanied by clinical efficacy. These data are discussed in light of the recent progression of immunotherapy caused by the addition of immune checkpoint inhibitors thus providing a general picture of the potential therapeutic efficacy of peptide‐based vaccines and their combination with other biological agents. In this review, we discuss the mechanism of the antitumor effect of peptide‐based vaccine therapy, development of our peptide vaccine, recent clinical trials using peptide vaccines for urological cancers, and perspectives of peptide‐based vaccine therapy.

MP70-09 IDENTIFICATION OF NINE NEW SUSCEPTIBILITY LOCI FOR PROSTATE CANCER IN THE JAPANESE POPULATION

Source of Funding: The work was supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. BK 20160112), the National Science Foundation for Postdoctoral Scientists of Jiangsu Province, China (Grant No. 1601018A), General Financial Grant from the China Postdoctoral Science Foundation (Grant No. 2017M611792), and Nanjing Medical Science and Technique Development Foundation (Grant No. QRX17048).