IL-15 induces strong but short-lived tumor-infiltrating CD8 T cell responses through the regulation of Tim-3 in breast cancer.

IL-15 has pivotal roles in the control of CD8(+) memory T cells and has been investigated as a therapeutic option in cancer therapy. Although IL-15 and IL-2 share many functions together, including the stimulation of CD8 T cell proliferation and IFN-γ production, the different in vivo roles of IL-15 and IL-2 have been increasingly recognized. Here, we explored the different effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells from resected breast tumors. We found that neither IL-2 nor IL-15 induced intratumoral CD8 T cell proliferation by itself, but after CD3/CD28-stimulation, IL-15 induced significantly higher proliferation than IL-2 during early time points, at day 2, day 3 and day 6. However, the IL-15-induced proliferation leveled off at day 9 and day 12, whereas IL-2 induced lower but progressive proliferation at each time point. Furthermore, IL-15 caused an early and robust increase of IFN-γ in the supernatant of TI cell cultures, which diminished at later time points, while the IL-2-induced IFN-γ production remained constant over time. In addition, the IL-15-costimulated CD8 T cells presented higher frequencies of apoptotic cells. The diminishing IL-15-induced response was possibly due to regulatory and/or exhaustion mechanisms. We did not observe increased IL-10 or PD-1 upregulation, but we have found an increase of Tim-3 upregulation on IL-15-, but not IL-2-stimulated cells. Blocking Tim-3 function using anti-Tim-3 antibodies resulted in increased IL-15-induced proliferation and IFN-γ production for a prolonged period of time, whereas adding Tim-3 ligand galectin 9 led to reduced proliferation and IFN-γ production. Our results suggest that IL-15 in combination of Tim-3 blocking antibodies could potentially act as an IL-2 alternative in tumor CD8 T cell expansion in vitro, a crucial step in adoptive T cell therapy.

Molecular determinants of cetuximab efficacy.

PURPOSE: To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS: Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction. RESULTS: There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment. CONCLUSION: This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment.

Genomic profiling associated with recurrence in patients with rectal cancer treated with chemoradiation.

PURPOSE: Stage II and III adenocarcinoma of the rectum has an overall 5-year survival rate of approximately 50%, and tumor recurrence remains a major problem despite an improvement in local control through chemotherapy and radiation. The efficacy of chemoradiation therapy may be significantly compromised as a result of interindividual variations in clinical response and host toxicity. Therefore, it is imperative to identify those patients who will benefit from chemoradiation therapy and those who will develop recurrent disease. In this study, we tested whether a specific pattern of 21 polymorphisms in 18 genes involved in the critical pathways of cancer progression (i.e., drug metabolism, tumor microenvironment, cell cycle regulation, and DNA repair) will predict the risk of tumor recurrence in rectal cancer patients treated with chemoradiation. PATIENTS AND METHODS: A total of 90 patients with Stage II or III rectal cancer treated with chemoradiation were genotyped using polymerase chain reaction (PCR)-based techniques for 21 polymorphisms. RESULTS: A polymorphism in interleukin (IL)-8 was individually associated with risk of recurrence. Classification and regression tree analysis of all polymorphisms and clinical variables developed a risk tree including the following variables: node status, IL-8, intracellular adhesion molecule-1, transforming growth factor-beta, and fibroblast growth factor receptor 4. CONCLUSION: Genomic profiling may help to identify patients who are at high risk for developing tumor recurrence, and those who are more likely to benefit from chemoradiation therapy. A larger prospective study is needed to validate these preliminary data using germline polymorphisms on tumor recurrences in rectal cancer patients treated with chemoradiation.

Epidermal growth factor receptor gene polymorphisms predict pelvic recurrence in patients with rectal cancer treated with chemoradiation.

An association between epidermal growth factor receptor (EGFR) signaling pathway and response of cancer cells to ionizing radiation has been reported. Recently, a polymorphic variant in the EGFR gene that leads to an arginine-to-lysine substitution in the extracellular domain at codon 497 within subdomain IV of EGFR has been identified. The variant EGFR (HER-1 497K) may lead to attenuation in ligand binding, growth stimulation, tyrosine kinase activation, and induction of proto-oncogenes myc, fos, and jun. A (CA)(n) repeat polymorphism in intron 1 of the EGFR gene that alters EGFR expression in vitro and in vivo has also been described. In the current pilot study, we assessed both polymorphisms in 59 patients with locally advanced rectal cancer treated with adjuvant or neoadjuvant chemoradiation therapy using PCR-RFLP and a 5'-end [gamma-(33)P]ATP-labeled PCR protocol. We tested whether either polymorphism alone or in combination can be associated with local recurrence in the setting of chemoradiation treatment. We found that patients with HER-1 497 Arg/Arg genotype or lower number of CA repeats (both alleles <20) tended to have a higher risk of local recurrence (P = 0.24 and 0.31, respectively). Combined analysis showed the highest risk for local recurrence was seen in patients who possessed both a HER-1 497 Arg allele and <20 CA repeats (P = 0.05, log-rank test). Our data suggest that the HER-1 R497K and EGFR intron 1 (CA)(n) repeat polymorphisms may be potential indicators of radiosensitivity in patients with rectal cancer treated with chemoradiation.

Gene polymorphisms of epidermal growth factor receptor and its downstream effector, interleukin-8, predict oxaliplatin efficacy in patients with advanced colorectal cancer.

BACKGROUND: Researchers have recently reported an association between the epidermal growth factor receptor (EGFR) pathway and platinum-chemotherapy sensitivity in cancer patients. The (CA)(n) repeat polymorphism in intron 1 of the EGFR gene has been identified and found to alter EGFR expression in vitro as well as in vivo. A higher number of these CA repeats is associated with lower EGFR levels, whereas a low number of repeats is associated with higher EGFR levels. A second key polymorphism within the EGFR pathway (HER1 R497K) is a single nucleotide change (G-A) in codon 497 of the EGFR gene, which leads to an arginine-lysine substitution in the extracellular domain of subdomain IV. Furthermore, interleukin-8 (IL-8), recently identified as an EGFR downstream effector, plays a vital role in tumor angiogenesis and progression. Three other polymorphisms, each related to the IL-8 gene, have also been identified as playing a pivotal role in the EGFR pathway: T-251A in the promoter region of the IL-8 gene, G+2607C in exon 2 of the IL-8 receptor CXCR1 gene, and C+785T in exon 11 of the IL-8 receptor CXCR2 gene. PATIENTS AND METHODS: In this study, we employed a 5'-end 33P-gATP-labeled polymerase chain reaction (PCR) protocol as well as the PCR-restriction fragment length polymorphism method in order to determine the genotypes for the previously mentioned polymorphisms in 105 patients with metastatic colorectal cancer. Tests were conducted to establish whether these polymorphisms could predict clinical outcome to 5-flourouracil/oxaliplatin chemotherapy. RESULTS: Among all patients assessed, those possessing < 20 EGFR CA repeats were more likely to show disease progression than were patients with >or= 20 CA repeats (P = 0.019; log-rank test). Also, patients with the CXCR1 GC genotype were found to have an increased relative risk of time to tumor progression that was 1.55 (95% CI, 0.8-3.0) times that of patients with the homozygous GG genotype (P = 0.17; log-rank test). CONCLUSION: Overall, our data suggest that gene polymorphisms active in the EGFR pathway may be associated with the sensitivity of colorectal cancer patients to platinum-based chemotherapy.

Characterization of HER2 status by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC).

The use of human epidermal growth factor receptor type 2 (HER2) gene amplification and overexpression as a molecular predictive marker has become critically important for proper selection of breast cancer patients for treatment with targeted therapeutic agents such as trastuzumab, lapatinib, pertuzumab, and T-DM1. A high level of sensitivity and specificity of molecular tests for this alteration is desirable. The American Society of Clinical Oncology and College of American Pathology have jointly established consensus guidelines to standardize characterization of this alteration in breast cancers. This chapter provides a brief overview of pre-analytic and analytical processing of breast specimens as well as subsequent molecular evaluation for HER2 status.

Gender-related survival differences associated with EGFR polymorphisms in metastatic colon cancer.

Evidence is accumulating supporting gender-related differences in the development of colonic carcinomas. Sex steroid hormone receptors are expressed in the colon and interact with epidermal growth factor receptor (EGFR), a gene widely expressed in colonic tissue. Increased EGFR expression is linked with poor prognosis in colon cancer. Within the EGFR gene there are two functional polymorphisms of interest: a polymorphism located at codon 497 (HER-1 R497K) and a dinucleotide (CA)(n) repeat polymorphism located within intron 1. These germ-line polymorphisms of EGFR were analyzed in genomic DNA from 318 metastatic colon cancer patients, 177 males and 141 females, collected from 1992 to 2003. Gender-related survival differences were associated with the HER-1 R497K polymorphism (P(interaction) = 0.003). Females with the HER-1 497 Arg/Arg variant had better overall survival (OS) when compared with the Lys/Lys and/or Lys/Arg variants. In males the opposite was true. The EGFR dinucleotide (CA)(n) repeat also trended with a gender-related OS difference (P(interaction) = 0.11). Females with both short <20 (CA)(n) repeat alleles had better OS than those with any long >or=20 (CA)(n) repeats. In males the opposite was true. Combination analysis of the two polymorphisms taken together also revealed the same gender-related survival difference (P(interaction) = 0.002). These associations were observed using multivariable analysis. The two polymorphisms were not in linkage disequilibrium and are independent of one another. This study supports the role of functional EGFR polymorphisms as independent prognostic markers in metastatic colon cancer. As a prognostic factor, these variants had opposite prognostic implications based on gender.

Association of methylenetetrahydrofolate reductase gene polymorphisms and sex-specific survival in patients with metastatic colon cancer.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating intracellular folate levels, which affects DNA synthesis and methylation. Two MTHFR gene polymorphisms, C677T and A1298C, are linked to altered enzyme activity. Several studies have shown these two polymorphisms to be associated with response to fluorouracil (FU) -based treatment in advanced colon cancer patients, but data are inconsistent and contradictory. Meanwhile, epidemiologic studies demonstrated that these MTHFR polymorphisms were associated with cancer risk in a sex-specific manner. We tested the hypothesis of whether these two polymorphisms are associated with sex-specific clinical outcome in metastatic colon cancer patients treated with FU-based chemotherapy. PATIENTS AND METHODS: This study included 318 patients (177 men and 141 women) with metastatic colon cancer treated between 1992 and 2003 at the University of Southern California/Norris Comprehensive Cancer Center or Los Angeles County/University of Southern California Medical Center. Peripheral blood samples were collected from each patient, and genomic DNA was extracted from WBCs. Two MTHFR gene polymorphisms (C677T and A1298C) were tested by fluorogenic 5'-nuclease assay. RESULTS: The A1298C polymorphism showed statistically significant differences in overall survival (OS) in female, but not male, patients with metastatic colon cancer (log-rank test, P = .038). Among females, OS was greater for patients with the A/A genotype (n = 67; median OS, 18.4 months) compared with patients with the A/C genotype (n = 50; median OS, 13.9 months) or C/C genotype (n = 10; median OS, 15.6 months). CONCLUSION: Although preliminary, these data support the role of the A1298C polymorphism in MTHFR as prognostic marker in female patients with metastatic colon cancer. Further studies are needed to confirm these findings.

ABCB1, SLCO1B1 and UGT1A1 gene polymorphisms are associated with toxicity in metastatic colorectal cancer patients treated with first-line irinotecan.

We tested specific gene polymorphisms known to be involved in the irinotecan (CPT-11) metabolic pathway. The combination of at least one SLCO1B1 521 T allele, one ABCB1 1236 C allele and one UGT1A1*28 variant 7 repeat demonstrated a statistically significant association with Grade 3/4 toxicities in metastatic colorectal cancer patients.

Cyclin D1 and epidermal growth factor polymorphisms associated with survival in patients with advanced colorectal cancer treated with Cetuximab.

The study aimed to investigate whether polymorphisms in genes of the EGFR signaling pathway are associated with clinical outcome in advanced colorectal cancer (CRC) patients treated with single-agent Cetuximab. Polymorphisms of interest in the EGFR pathway include: cyclin D1 (CCND1) A870G, cyclooxygenase 2 (Cox-2) G-765C, epidermal growth factor (EGF) A61G, epidermal growth factor receptor (EGFR) codon R497 K, EGFR CA dinucleotide repeat in intron 1, interleukin (IL)-8 T-251A and vascular endothelial growth factor (VEGF) C936 T gene polymorphisms. Thirty-nine metastatic CRC patients were enrolled in the IMCL-0144 trial and treated with single-agent Cetuximab. Using the polymerase chain reaction-restriction fragment length polymorphism method, gene polymorphisms of CCND1, COX-2, EGF, EGFR, IL-8 and VEGF were assessed from genomic DNA extracted from blood samples. A significant association was found between the CCND1 A870G polymorphism and overall survival in our 39 CRC subjects. Patients with the AA homozygous genotype survived for a median of 2.3 months [95% confidence interval (CI)=2.1-5.7], whereas those with any G allele (AG, GG genotype) survived for a median of 8.7 months (95% CI=4.4-13.5) (P=0.019, log-rank test). When we analysed the cyclin D1 and EGF polymorphisms together, patients with favourable genotypes (EGF any A allele and CCND1 any G allele) showed a median survival time of 12 months (95% CI=4.8-15.2), whereas patients with any two unfavourable genotypes (EGF GG or CCND1 AA) showed a median survived time of 4.4 months (95% CI=2.1-5.7) (P=0.004, log-rank test). The findings of this pilot study suggest that the cyclin D1 A870G and the EGF A61G polymorphisms may be useful molecular markers for predicting clinical outcome in CRC patients treated with single-agent Cetuximab.