Immunogenomic profiles associated with response to neoadjuvant chemoradiotherapy in patients with rectal cancer.

BACKGROUND: Accumulating evidence suggests that radiotherapy success has an immune-associated component. The immunogenomic profiles associated with responses to chemoradiotherapy (CRT) were assessed in patients with locally advanced rectal cancer in this study. METHODS: CD8+ tumour-infiltrating lymphocyte (TIL) and stromal lymphocyte densities were assessed by immunohistochemistry using pretreatment biopsies from patients with advanced rectal cancer who had preoperative CRT. Whole-exome sequencing and gene expression microarray analysis were conducted to investigate the genomic properties associated with the response to CRT and CD8+ TIL density. Response to CRT was determined based on Dworak tumour regression grade (TRG); tumours with complete (TRG 4) or near-complete (TRG 3) regression were grouped as good responders, and those with TRG 1 as non-responders. RESULTS: Immunohistochemical examinations (275 patients) showed that pre-CRT CD8+ TIL density was associated with better response to CRT and improved recurrence-free survival, whereas pre-CRT stromal CD8+ cell density was not associated with either response to CRT or recurrence-free survival. Whole-exome sequencing (74 patients) showed that the numbers of single-nucleotide variations (SNVs) and neoantigens predicted from SNVs were higher in good responders than in non-responders, and these correlated positively with CD8+ TIL density (rS = 0·315 and rS = 0·334 respectively). Gene expression microarray (90 patients) showed that CD8A expression correlated positively with the expression of programmed cell death 1 (PDCD1) (rS = 0·264) and lymphocyte-activation gene 3 (LAG3) (rS = 0·507). CONCLUSION: Pre-CRT neoantigen-specific CD8+ T cell priming may be a key event in CRT responses where immune checkpoint molecules could be useful targets to enhance tumour regression.

ANTECEDENTES: Las evidencias existentes sugieren que el éxito de la radioterapia tiene un componente asociado con el sistema inmunitario. En este estudio se evaluaron los perfiles inmunogenómicos asociados con la respuesta a la quimiorradioterapia (chemoradiotherapy, CRT) en pacientes con cáncer de recto localmente avanzado. MÉTODOS: Las densidades de los linfocitos infiltrantes de tumor CD8+ (tumour-infiltrating lymphocyte, TIL) y de los linfocitos del estroma se evaluaron por inmunohistoquímicas en las biopsias antes del tratamiento de pacientes con cáncer de recto localmente avanzado que recibieron CRT preoperatoria. Se realizó secuenciación de todo el exoma, así como microarrays de expresión génica, para investigar las propiedades genómicas asociadas con la respuesta a la CRT y a la densidad de los TIL CD8+. La respuesta a la CRT se determinó según el grado de regresión del tumor de Dworak (tumour regression grade, TRG), agrupándose como buenos respondedores los casos de regresión tumoral completa (TRG4) o casi completa (TRG3) y como no respondedores, los casos de grado TRG1. RESULTADOS: Los exámenes inmunohistoquímicos (n = 275) mostraron que la densidad pre-CRT de TIL CD8+ se asoció con una mejor respuesta a la CRT y una mejor supervivencia libre de recidiva, aunque la densidad de células CD8+ del estroma previa a la CRT no se asoció con la respuesta a la CRT ni con la supervivencia libre de recidiva. La secuenciación de todo el exoma (n = 74) mostró que el número de variaciones de nucleótidos únicos (single nucleotide variations, SNVs) y los neoantígenos predichos a partir de los SNVs fueron mayores en los que respondieron bien que en los que no respondieron, y éstos se correlacionaron positivamente con la densidad de los TIL CD8+ (Spearman r = 0,315 y r = 0,334 respectivamente). Los microarrays de expresión génica (n = 90) mostraron que la expresión CD8A se correlacionó positivamente con la expresión del ligando de muerte programada-1 (r = 0,264) y con el antígeno linfocitario del gen 3 (r = 0,507). CONCLUSIÓN: La activación de células T CD8+ específicas para neoantígenos previa a la CRT puede ser un evento clave en la respuesta a la misma donde las moléculas del punto de control inmunitario podrían ser dianas útiles para intensificar la regresión del tumor.

Case report: dose adjustment of warfarin using genetic information and plasma concentration monitoring.

WHAT IS KNOWN AND OBJECTIVE: Carbamazepine is known to interact with warfarin. We report on a case of this interaction and on its management using the patient's genetic information. CASE SUMMARY: The case concerns a 74-year-old Japanese woman with a mood disorder and a central retinal vein occlusion. She was on therapy that included carbamazepine and had started to take warfarin. However, the patient's prothrombin time expressed as the international normalized ratio (PT-INR) was 1·40 despite taking a dose three times higher than the average. The patient's S-warfarin concentration was 0·15 µg/mL and R-warfarin was 0·52 µg/mL. Her cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex, subunit 1 (VKORC1), genotypes were *1/*1 and -1639GA, respectively. The VKORC1 genotype indicated that she would require an even higher dose. We proposed a further increase in dose and the patient's PT-INR rose to 1·99. WHAT IS NEW AND CONCLUSION: The patient required a high warfarin dose because of the VKORC1 genotype, and induction of CYP2C9 by carbamazepine. We improved the patient's pharmacotherapy based on her genetic information.

Addressing the knowledge gap in the genomic landscape and tailored therapeutic approaches to adolescent and young adult cancers.

BACKGROUND: Adolescents and young adults (AYAs) represent a small proportion of patients with cancer. The genomic profiles of AYA patients with cancer are not well-studied, and outcomes of genome-matched therapies remain largely unknown. PATIENTS AND METHODS: We investigated differences between Japanese AYA and older adult (OA) patients in genomic alterations, therapeutic evidence levels, and genome-matched therapy usage by cancer type. We also assessed treatment outcomes. RESULTS: AYA patients accounted for 8.3% of 876 cases. Microsatellite instability-high and/or tumor mutation burden was less common in AYA patients (1.4% versus 7.7% in OA; P = 0.05). However, BRCA1 alterations were more common in AYA patients with breast cancer (27.3% versus 1.7% in OA; P = 0.01), as were MYC alterations in AYA patients with colorectal cancer (23.5% versus 5.8% in OA; P = 0.02) and sarcoma (31.3% versus 3.4% in OA; P = 0.01). Genome-matched therapy use was similar between groups, with overall survival tending to improve in both. However, in AYA patients, the small number of patients prevented statistical significance. Comprehensive genomic profiling-guided genome-matched therapy yielded encouraging results, with progression-free survival of 9.0 months in AYA versus 3.7 months in OA patients (P = 0.59). CONCLUSION: Our study suggests that tailored therapeutic approaches can benefit cancer patients regardless of age.

Quantitative characterization of T-cell repertoire in allogeneic hematopoietic stem cell transplant recipients.

Allogeneic hematopoietic stem cell transplantation (HSCT) is one of curative treatment options for patients with hematologic malignancies. Although GVHD mediated by the donor's T lymphocytes remains the most challenging toxicity of allo-HSCT, graft-versus-leukemia (GVL) effect targeting leukemic cells, has an important role in affecting the overall outcome of patients with AML. Here we comprehensively characterized the TCR repertoire in patients who underwent matched donor or haplo-cord HSCT using next-generation sequencing approach. Our study defines the functional kinetics of each TCRA and TCRB clone, and changes in T-cell diversity (with identification of CDR3 sequences) and the extent of clonal expansion of certain T-cells. Using this approach, our study demonstrates that higher percentage of cord-blood cells at 30 days after transplant was correlated with higher diversity of TCR repertoire, implicating the role of cord-chimerism in enhancing immune recovery. Importantly, we found that GVHD and relapse, exclusive of each other, were correlated with lower TCR repertoire diversity and expansion of certain T-cell clones. Our results highlight novel insights into the balance between GVHD and GVL effect, suggesting that higher diversity early after transplant possibly implies lower risks of both GVHD and relapse following the HSCT transplantation.

Accommodation of foreign genes into the Sendai virus genome: sizes of inserted genes and viral replication.

Sendai virus (SeV) is an enveloped virus with a negative sense genome RNA of about 15.3 kb. We previously established a system to recover an infectious virus entirely from SeV cDNA and illustrated the feasibility of using SeV as a novel expression vector. Here, we have attempted to insert a series of foreign genes into SeV of different lengths to learn how far SeV can accommodate extra genes and how the length of inserted genes affects viral replication in cells cultured in vitro and in the natural host, mice. We show that a gene up to 3.2 kb can be inserted and efficiently expressed and that the replication speed as well as the final virus titers in cell culture are proportionally reduced as the inserted gene length increases. In vivo, such a size-dependent effect was not very clear but a remarkably attenuated replication and pathogenicity were generally seen. Our data further confirmed reinforcement of foreign gene expression in vitro from the V(-) version of SeV in which the accessory V gene had been knocked out. Based on these results, we discuss the utility of SeV vector in terms of both efficiency and safety.

Kinetic Interpretation of the Importance of OATP1B3 and MRP2 in Docetaxel-Induced Hematopoietic Toxicity.

Neutropenia is a lethal dose-limiting toxicity of docetaxel. Our previous report indicated that the prevalence of severe docetaxel-induced neutropenia is significantly associated with genetic polymorphisms in solute carrier organic anion transporter 1B3 (SLCO1B3) (encoding organic anion-transporting polypeptide 1B3 (OATP1B3)) and ATP-binding cassette subfamily C2 (ABCC2) (encoding multidrug-resistant-associated protein 2 (MRP2)). Therefore, we investigated their significance in docetaxel-induced neutropenia. In vitro experiments suggested their possible involvement in the hepatic uptake of docetaxel and its efflux from bone marrow cells. To further characterize a quantitative impact of OATP1B3 and MRP2 on neutropenia, we used an in silico simulation of the neutrophil count in docetaxel-treated subjects with functional changes in OATP1B3 and MRP2 in a pharmacokinetic/pharmacodynamic model. The clinically reported odds ratios for docetaxel-induced neutropenia risk were explained by the decreased function of OATP1B3 and MRP2 to 41 and 32%, respectively. These results suggest that reduced activities of OATP1B3 and MRP2 associated with systemic exposure and local accumulation in bone marrow cells, respectively, account for the docetaxel-induced neutropenia observed clinically.

CYP2D6 genotype and adjuvant tamoxifen: meta-analysis of heterogeneous study populations.

The International Tamoxifen Pharmacogenomics Consortium was established to address the controversy regarding cytochrome P450 2D6 (CYP2D6) status and clinical outcomes in tamoxifen therapy. We performed a meta-analysis on data from 4,973 tamoxifen-treated patients (12 globally distributed sites). Using strict eligibility requirements (postmenopausal women with estrogen receptor-positive breast cancer, receiving 20 mg/day tamoxifen for 5 years, criterion 1); CYP2D6 poor metabolizer status was associated with poorer invasive disease-free survival (IDFS: hazard ratio = 1.25; 95% confidence interval = 1.06, 1.47; P = 0.009). However, CYP2D6 status was not statistically significant when tamoxifen duration, menopausal status, and annual follow-up were not specified (criterion 2, n = 2,443; P = 0.25) or when no exclusions were applied (criterion 3, n = 4,935; P = 0.38). Although CYP2D6 is a strong predictor of IDFS using strict inclusion criteria, because the results are not robust to inclusion criteria (these were not defined a priori), prospective studies are necessary to fully establish the value of CYP2D6 genotyping in tamoxifen therapy.