Expression of the SART1 tumor rejection antigen in renal cell carcinoma

Immunotherapeutic Strategies for Malignant Glioma

BACKGROUND

Despite advances in surgery, radiation therapy, and chemotherapy, only modest improvement has been achieved in the survival of patients with malignant gliomas.

METHODS

The authors review the immunologic aspects of gliomas, potential targets for therapy, and issues surrounding current immunotherapeutic strategies directed against malignant gliomas.

RESULTS

The blood-brain barrier and the purported immunological privilege of the brain are not necessarily insurmountable obstacles to effective immunotherapy for brain tumors. Preclinical studies suggest a number of potential therapeutic avenues. Translational studies offer the prospect of providing substantial new information about immunological trafficking in the nervous system and suggesting the most fruitful approaches to immunotherapy for malignant gliomas.

CONCLUSIONS

More effective adjuvant treatments for malignant gliomas are needed. The applicability of immunological approaches in the treatment of these tumors warrants continued study.

Identification of novel SNPs in glioblastoma using targeted resequencing

High-throughput sequencing opens avenues to find genetic variations that may be indicative of an increased risk for certain diseases. Linking these genomic data to other “omics” approaches bears the potential to deepen our understanding of pathogenic processes at the molecular level. To detect novel single nucleotide polymorphisms (SNPs) for glioblastoma multiforme (GBM), we used a combination of specific target selection and next generation sequencing (NGS). We generated a microarray covering the exonic regions of 132 GBM associated genes to enrich target sequences in two GBM tissues and corresponding leukocytes of the patients. Enriched target genes were sequenced with Illumina and the resulting reads were mapped to the human genome. With this approach we identified over 6000 SNPs, including over 1300 SNPs located in the targeted genes. Integrating the genome-wide association study (GWAS) catalog and known disease associated SNPs, we found that several of the detected SNPs were previously associated with smoking behavior, body mass index, breast cancer and high-grade glioma. Particularly, the breast cancer associated allele of rs660118 SNP in the gene SART1 showed a near doubled frequency in glioblastoma patients, as verified in an independent control cohort by Sanger sequencing. In addition, we identified SNPs in 20 of 21 GBM associated antigens providing further evidence that genetic variations are significantly associated with the immunogenicity of antigens.

Update on vaccine development for renal cell cancer

Renal cell carcinoma (RCC) remains a significant health concern that frequently presents as metastatic disease at the time of initial diagnosis. Current first-line therapeutics for the advanced-stage RCC include antiangiogenic drugs that have yielded high rates of objective clinical response; however, these tend to be transient in nature, with many patients becoming refractory to chronic treatment with these agents. Adjuvant immunotherapies remain viable candidates to sustain disease-free and overall patient survival. In particular, vaccines designed to optimize the activation, maintenance, and recruitment of specific immunity within or into the tumor site continue to evolve. Based on the integration of increasingly refined immunomonitoring systems in both translational models and clinical trials, allowing for the improved understanding of treatment mechanism(s) of action, further refined (combinational) vaccine protocols are currently being developed and evaluated. This review provides a brief history of RCC vaccine development, discusses the successes and limitations in such approaches, and provides a rationale for developing combinational vaccine approaches that may provide improved clinical benefits to patients with RCC.

Expression of SART-1 mRNA in canine squamous cell carcinomas

SART-1, a squamous cell carcinoma (SCC) antigen recognized by cytotoxic T lymphocytes, has been useful in human cancer therapy. The SART-1(259) peptide is a potential candidate for vaccine. The present study examined an orthologue of the mRNA coding this peptide in canine SCCs. Specimens were obtained from seven canine patients with SCC, and the mRNA was isolated from the samples. The SART-1 and beta-actin genes were amplified by reverse-transcription polymerase chain reaction, using the isolated mRNA as a template. Canine SART-1 was amplified in six of the seven specimens, while beta-actin was detected in all the samples. In dogs, carcinomas expressing SART-1 could be a target for cytotoxic T lymphocyte mediated immunotherapy.

The basic biology and immunobiology of renal cell carcinoma: considerations for the clinician

These are indeed exciting times in the study of RCC. No longer should the clinician view RCC as a single entity, nor should the researcher pose basic questions without considering the biologic diversity of this tumor. The success of novel targeted therapeutic strategies will depend on the systematic study of genetic and epigenetic events and their relationship to aberrant protein expression and function, and an understanding of the permissive microenvironment that allows the tumor to be sustained. These studies must be correlated in a rigorous fashion to clinical parameters and outcomes. Progress against this elusive tumor will require a continuous translational dialogue between laboratory and clinical investigators.

T-cell receptor V? gene usage by T cells reactive with the tumor-rejection antigen SART-1 in oral squamous cell carcinoma

We recently described that the SART-1(690-698) peptide could induce HLA-A24-restricted cytotoxic T lymphocytes (CTLs), which recognize the SART-1(259) (+) tumor cells from peripheral blood mononuclear cells (PBMCs) of HLA-A24(+) cancer patients. In our study, in 5 of 14 HLA-A24(+) patients with oral squamous cell carcinomas (SCCs), CTLs could be induced with the SART-1(690-698) peptide from the PBMCs. In 2 of the patients from whom the highest CTL activities were induced, the T-cell receptor (TCR) Vbeta repertoire expressed by the SART-1(690-698)-specific CTLs was found to be restricted and multiple Vbeta families were predominantly expressed in each patient. Although the predominant Vbeta families were different between the 2 patients, Vbeta7 was highly and commonly predominant. The same predominant Vbeta families were also detected in the tumor-infiltrating lymphocytes (TILs) from each patient, and each Vbeta family contained one or more unique T-cell clonotypes. The unique T-cell clonotypes were found to be common between the TILs and SART-1(690-698)-specific CTLs from each patient, and especially 2 T-cell clonotypes with Vbeta7 were identical even in the 2 patients. One of the 2 T-cell clonotypes with Vbeta7 was detected in the TILs from 11 of 14 HLA-A24(+) patients and another was found in those from 8 of HLA-A24(+) patients, while none of 10 HLA-A24(-) patients demonstrated both T-cell clonotypes. These results strongly suggest that the T-cell clonotypes with Vbeta7 are major TCR Vbeta genes expressed by SART-1(690-698)-specific CTLs. Furthermore, autologous tumor cells from one of the HLA-A24(+) patients stimulated the PBMCs and regional lymph node cells (LNCs) to expand the same T-cell clonotypes as those in the SART-1(690-698)-specific CTLs. These results strongly suggest that the SART-1(690-698)-specific CTLs clearly accumulate in vivo, especially in the TILs, as a consequence of in situ antigenic stimulation by autologous tumor cells. The identification of the unique TCR Vbeta genes used by SART-1(259)-specific CTLs should help to improve the diagnosis of the specific immune response in patients with SART-1(259) (+) cancers, especially during anticancer immunotherapy.