Individual patient risk stratification of high‐risk neuroblastomas using a two‐gene score suited for clinical use

Several gene expression‐based prognostic signatures have been described in neuroblastoma, but none have successfully been applied in the clinic. Here we have developed a clinically applicable prognostic gene signature, both with regards to number of genes and analysis platform. Importantly, it does not require comparison between patients and is applicable amongst high‐risk patients. The signature is based on a two‐gene score (R‐score) with prognostic power in high‐stage tumours (stage 4 and/or MYCN‐amplified diagnosed after 18 months of age). QPCR‐based and array‐based analyses of matched cDNAs confirmed cross platform (array‐qPCR) transferability. We also defined a fixed cut‐off value identifying prognostically differing subsets of high‐risk patients on an individual patient basis. This gene expression signature independently contributes to the current neuroblastoma classification system, and if prospectively validated could provide further stratification of high‐risk patients, and potential upfront identification of a group of patients that are in need of new/additional treatment regimens.     

Antitumor activity of an anti‐CD98 antibody

CD98 is expressed on several tissue types and specifically upregulated on fast‐cycling cells undergoing clonal expansion. Various solid (e.g., nonsmall cell lung carcinoma) as well as hematological malignancies (e.g., acute myeloid leukemia) overexpress CD98. We have identified a CD98‐specific mouse monoclonal antibody that exhibits potent preclinical antitumor activity against established lymphoma tumor xenografts. Additionally, the humanized antibody designated IGN523 demonstrated robust tumor growth inhibition in leukemic cell‐line derived xenograft models and was as efficacious as standard of care carboplatin in patient‐derived nonsmall lung cancer xenografts. In vitro studies revealed that IGN523 elicited strong ADCC activity, induced lysosomal membrane permeabilization and inhibited essential amino acid transport function, ultimately resulting in caspase‐3 and ‐7‐mediated apoptosis of tumor cells. IGN523 is currently being evaluated in a Phase I clinical trial for acute myeloid leukemia (NCT02040506). Furthermore, preclinical data support the therapeutic potential of IGN523 in solid tumors.     

Association of Fusobacterium nucleatum with clinical and molecular features in colorectal serrated pathway

Human gut microbiota is being increasingly recognized as a player in colorectal cancers (CRCs). Evidence suggests that Fusobacterium nucleatum (F. nucleatum) may contribute to disease progression and is associated with CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) in CRCs; however, to date, there are no reports about the relationship between F. nucleatum and molecular features in the early stage of colorectal tumorigenesis. Therefore, we investigated the presence of F. nucleatum in premalignant colorectal lesions. In total, 465 premalignant lesions (343 serrated lesions and 122 non‐serrated adenomas) and 511 CRCs were studied. We determined the presence of F. nucleatum and analyzed its association with molecular features including CIMP, MSI and microRNA‐31 status. F. nucleatum was detected in 24% of hyperplastic polyps, 35% of sessile serrated adenomas (SSAs), 30% of traditional serrated adenomas (TSAs) and 33% of non‐serrated adenomas. F. nucleatum was more frequently detected in CIMP‐high premalignant lesions than in CIMP‐low/zero lesions (p = 0.0023). In SSAs, F. nucleatum positivity increased gradually from sigmoid colon to cecum (p = 0.042). F. nucleatum positivity was significantly higher in CRCs (56%) than in premalignant lesions of any histological type (p < 0.0001). In conclusion, F. nucleatum was identified in premalignant colorectal lesions regardless of histopathology but was more frequently associated with CIMP‐high lesions. Moreover, F. nucleatum positivity increased according to histological grade, suggesting that it may contribute to the progression of colorectal neoplasia. Our data also indicate that F. nucleatum positivity in SSAs may support the “colorectal continuum” concept.     

Epstein‐Barr virus infection induces miR‐21 in terminally differentiated malignant B cells

The association of Epstein‐Barr virus (EBV) with plasmacytoid malignancies is now well established but how the virus influences microRNA expression in such cells is not known. We have used multiple myeloma (MM) cell lines to address this issue and find that an oncomiR, miR‐21 is induced after in vitro EBV infection. The PU.1 binding site in miR‐21 promoter was essential for its activation by the virus. In accordance with its noted oncogenic functions, miR‐21 induction in EBV infected MM cells caused downregulation of p21 and an increase in cyclin D3 expression. EBV infected MM cells were highly tumorigenic in SCID mice. Given the importance of miR‐21 in plasmacytoid malignancies, our findings that EBV could further exacerbate the disease by inducing miR‐21 has interesting implications both in terms of diagnosis and future miR based therapeutical approaches for the virus associated plasmacytoid tumors.     

Wnt‐3a‐activated human fibroblasts promote human keratinocyte proliferation and matrix destruction

Aberrant Wnt regulation, detectable by nuclear translocation of beta‐catenin, is a hallmark of many cancers including skin squamous cell carcinomas (SCCs). By analyzing primary human skin SCCs, we demonstrate that nuclear beta‐catenin is not restricted to SCC cells but also detected in stromal fibroblasts, suggesting an important role for aberrant Wnt regulation also in the tumor microenvironment. When human keratinocytes and fibroblasts were treated with Wnt‐3a, fibroblasts proved to be more responsive. Accordingly, Wnt‐3a did not alter HaCaT cell functions in a cell‐autonomous manner. However, when organotypic cultures (OTCs) were treated with Wnt‐3a, HaCaT keratinocytes responded with increased proliferation. As nuclear beta‐catenin was induced only in the fibroblasts, this argued for a Wnt‐dependent, paracrine keratinocyte stimulation. Global gene expression analysis of Wnt‐3a‐stimulated fibroblasts identified genes encoding interleukin‐8 (IL‐8) and C‐C motif chemokine 2 (CCL‐2) as well as matrix metalloproteinase‐1 (MMP‐1) as Wnt‐3a targets. In agreement, we show that IL‐8 and CCL‐2 were secreted in high amounts by Wnt‐3a‐stimulated fibroblasts also in OTCs. The functional role of IL‐8 and CCL‐2 as keratinocyte growth regulators was confirmed by directly stimulating HaCaT cell proliferation in conventional cultures. Most important, neutralizing antibodies against IL‐8 and CCL‐2 abolished the Wnt‐dependent HaCaT cell hyperproliferation in OTCs. Additionally, MMP‐1 was expressed in high amounts in Wnt‐3a‐stimulated OTCs and degraded the stromal matrix. Thus, our data show that Wnt‐3a stimulates fibroblasts to secrete both keratinocyte proliferation‐inducing cytokines and stroma‐degrading metalloproteinases, thereby providing evidence for a novel Wnt deregulation in the tumor‐stroma directly contributing to skin cancer progression.     

Incidence and patterns of late recurrences in colon cancer patients

Long‐term recurrences of colon cancer raised questions about the possible benefit of prolonging the recommended active 5‐year surveillance. The aim of this study was to determine, for the first time, the incidence and patterns of late 10‐year recurrence following curative resection of colon cancer. Data were obtained from two French digestive cancer registries. A total of 3,622 patients under 85 years resected for cure for colon cancer diagnosed between 1985 and 2000 were included. Information regarding recurrences was actively collected. Cumulative failure rates at 10 years were estimated using Kaplan–Meier estimates corrected by cause‐specific hazards, and multivariable analysis was performed using a model for the subdistribution of a competing risk proposed by Fine and Gray. The overall cumulative recurrence rate between 5 and 10 years after initial surgery was 2.9% for local recurrence and 4.3% for distant metastasis. Among men with no recurrence 5 years after diagnosis of colon cancer, 1 in 12 developed a recurrence between 5 and 10 years, and the corresponding cumulative rate was 7.8%. The frequency was 1 in 19 for women, corresponding to a cumulative rate of 5.2%. In the multivariate analysis, non‐emergency diagnostic feature, female sex and age under 75 were associated with a lower risk of recurrence. Stage at diagnosis was not a predictor of late recurrence. Late recurrence after colon cancer resection with curative intent can occur. A regular clinical follow‐up is necessary to detect early signs of possible recurrence.     

Hyperpolarized [1,3‐13C2]ethyl acetoacetate is a novel diagnostic metabolic marker of liver cancer

An increased prevalence of liver diseases such as hepatitis C and nonalcoholic fatty liver results in an augmented incidence of the most common form of liver cancer, hepatocellular carcinoma (HCC). HCC is most often found in the cirrhotic liver and it can therefore be challenging to rely on anatomical information alone when diagnosing HCC. Valuable information on specific cellular metabolism can be obtained with high sensitivity thanks to an emerging magnetic resonance (MR) technique that uses ¹³C labeled hyperpolarized molecules. Our interest was to explore potential new high contrast metabolic markers of HCC using hyperpolarized ¹³C‐MR. This work led to the identification of a class of substrates, low molecular weight ethyl‐esters, which showed high specificity for carboxyl esterases and proved in many cases to possess good properties for signal enhancement. In particular, hyperpolarized [1,3‐¹³C₂]ethyl acetoacetate (EAA) was shown to provide a metabolic fingerprint of HCC. Using this substrate a liver cancer implanted in rats was diagnosed as a consequence of an ～4 times higher metabolic substrate‐to‐product ratio than in the surrounding healthy tissue, (p = 0.009). Unregulated cellular uptake as well as cosubstrate independent enzymatic conversion of EAA, made this substrate highly useful as a hyperpolarized ¹³C‐MR marker. This could be appreciated by the signal‐to‐noise (SNR) obtained from EAA, which was comparable to the SNR reported in a literature liver cancer study with state‐of‐the‐art hyperpolarized substrate, [1‐¹³C]pyruvate. Also, the contrast‐to‐noise (CNR) in the EAA based metabolic ratio images was significantly improved compared with the CNR in equivalent images reported using [1‐¹³C]pyruvate.