YWHAE loss of function causes a rare neurodevelopmental disease with brain abnormalities in human and mouse.

PURPOSE: Miller-Dieker syndrome is caused by a multiple gene deletion, including PAFAH1B1 and YWHAE. Although deletion of PAFAH1B1 causes lissencephaly unambiguously, deletion of YWHAE alone has not clearly been linked to a human disorder. METHODS: Cases with YWHAE variants were collected through international data sharing networks. To address the specific impact of YWHAE loss of function, we phenotyped a mouse knockout of Ywhae. RESULTS: We report a series of 10 individuals with heterozygous loss-of-function YWHAE variants (3 single-nucleotide variants and 7 deletions <1 Mb encompassing YWHAE but not PAFAH1B1), including 8 new cases and 2 follow-ups, added with 5 cases (copy number variants) from literature review. Although, until now, only 1 intragenic deletion has been described in YWHAE, we report 4 new variants specifically in YWHAE (3 splice variants and 1 intragenic deletion). The most frequent manifestations are developmental delay, delayed speech, seizures, and brain malformations, including corpus callosum hypoplasia, delayed myelination, and ventricular dilatation. Individuals with variants affecting YWHAE alone have milder features than those with larger deletions. Neuroanatomical studies in Ywhae-/- mice revealed brain structural defects, including thin cerebral cortex, corpus callosum dysgenesis, and hydrocephalus paralleling those seen in humans. CONCLUSION: This study further demonstrates that YWHAE loss-of-function variants cause a neurodevelopmental disease with brain abnormalities.

The detection of specific hypermethylated WIF1 and NPY genes in circulating DNA by crystal digital PCR™ is a powerful new tool for colorectal cancer diagnosis and screening.

BACKGROUND: In oncology, liquid biopsy is of major relevance from theranostic point of view. The searching for mutations in circulating tumor DNA (ctDNA) in case of colorectal cancers (CRCs) allows the optimization of patient care. In this context, independent of mutation status biomarkers are required for its detection to confirm the presence of ctDNA in liquid biopsies. Indeed, the hypermethylation of NPY and WIF1 genes appear to be an ideal biomarker for the specific detection of ctDNA in CRCs. The objective of this work is to develop the research of hypermethylation of NPY and WIF1 by Crystal Digital PCR™ for the detection of ctDNA in CRCs. METHODS: Detection of hypermethylated NPY and WIF1 was developed on Cristal digital PCR™. Biological validation was performed from a local cohort of 22 liquid biopsies and 23 tissue samples from patients with CRC. These patients were treated at the University Hospital of Besancon (France). RESULTS: The local cohort study confirmed that NPY and WIF1 were significantly hypermethylated in tumor tissues compared to adjacent non-tumor tissues (WIF1 p < 0.001; NPY p < 0.001; non-parametric Wilcoxon paired-series test). Histological characteristics, tumor stages or mutation status were not correlated to the methylation profiles. On the other hand, hypermethylation of NPY or WIF1 in liquid biopsy had a 95.5% [95%CI 77-100%] sensitivity and 100% [95%CI 69-100%] specificity. CONCLUSION: Using Crystal digital PCR™, this study shows that hypermethylation of NPY and WIF1 are constant specific biomarkers of CRCs regardless of a potential role in carcinogenesis.

Temporal and spatial heterogeneity of HER2 status in metastatic colorectal cancer.

BACKGROUND: HER2-targeted therapies have recently emerged as an option in the management of metastatic colorectal cancer (mCRC) overexpressing HER2. However, data regarding HER2 status in primary CRC and its corresponding liver metastases are limited, potentially influencing clinical decisions. Therefore, the aim of this study was to compare the HER2 status in primary CRC and paired liver metastases. METHODS: Patients with mCRC who were operated from their primary colorectal cancer and their corresponding synchronous or metachronous liver metastases, in the digestive surgery department of Besançon University Hospital, between April 1999 and October 2021, were included. Tissue microarrays were constructed from matched primary CRC and liver metastastic tissue samples. HER2 status was assessed by immunohistochemistry and in situ hybridization according to Valtorta's criteria. RESULTS: A series of 108 paired primary CRC and liver metastases, including a series of multiple liver metastases originating from the same patients (n = 24), were assessed. Among the primary CRC, 89 (82.4%), 17 (15.8%) and 2 (1.8%) cases were scored 0, 1 + and 2 + respectively. In liver metastases, 99 (91.7%), 7 (6.5%) and 2 (1.8%) were scored 0, 1 + and 2, respectively. Overall, there was a 19% discrepancy rate in HER2 status between primary CRC and metastases, which increased to 21% in cases with multiple synchronous or metachronous liver metastases in a given patient. No significant difference was found between metachronous and synchronous metastases regarding the HER2 status (p = 0.237). CONCLUSIONS: Our study highlights the temporal and spatial heterogeneity of HER2 status between primary CRC and corresponding liver metastases. These findings raise the question of a sequential evaluation of the HER2 status during disease progression, to provide the most suitable treatment strategy.

Evaluation of immune infiltrate according to the HER2 status in colorectal cancer.

BACKGROUND AND AIMS: In colorectal cancer (CRC), HER2 targeting is a promising treatment and immune infiltrate is an important area of research and strategy. Data regarding HER2 status and immune infiltrate are lacking. The aim of this study was to compare the immune infiltrate between HER2 amplified and non-amplified categories in proficient MisMatchRepair (pMMR)/microsatellite stable (MSS) CRC. METHODS: HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization were performed in a retrospective series of 654 CRC. Lymphocyte infiltrate was analysed by anti-CD3, CD8 and CD4 IHC and evaluated digitally using QuPath software. RESULTS: Among the 654 CRC, we first observed a decreased CD3+ and CD8+ infiltrate between HER2 amplified (all IHC 3+ except one 2+) and non-amplified HER2 2+ IHC CRC (p = 0.059 and 0.072 respectively). A supplementary analysis of 258 pMMR/MSS CRC from the previous cohort, displaying all the IHC scores (0, 1+, 2+, 3+), showed a lower CD3+ infiltrate between HER2 amplified versus HER2 0 (p = 0.002), 1+ (p = 0.088) and non-amplified 2+ (p = 0.081) IHC cases. CONCLUSIONS: Our original findings suggest that in pMMR/MSS CRC, the immune infiltrate is reduced in HER2 amplified versus other HER2 categories. These data might be useful for future strategies combining anti-HER2 treatments and immune checkpoint inhibitors and need to be confirmed in larger CRC cohorts.

Combining globally search for a regular expression and print matching lines with bibliographic monitoring of genomic database improves diagnosis.

Introduction: Exome sequencing has a diagnostic yield ranging from 25% to 70% in rare diseases and regularly implicates genes in novel disorders. Retrospective data reanalysis has demonstrated strong efficacy in improving diagnosis, but poses organizational difficulties for clinical laboratories. Patients and methods: We applied a reanalysis strategy based on intensive prospective bibliographic monitoring along with direct application of the GREP command-line tool (to "globally search for a regular expression and print matching lines") in a large ES database. For 18 months, we submitted the same five keywords of interest [(intellectual disability, (neuro)developmental delay, and (neuro)developmental disorder)] to PubMed on a daily basis to identify recently published novel disease-gene associations or new phenotypes in genes already implicated in human pathology. We used the Linux GREP tool and an in-house script to collect all variants of these genes from our 5,459 exome database. Results: After GREP queries and variant filtration, we identified 128 genes of interest and collected 56 candidate variants from 53 individuals. We confirmed causal diagnosis for 19/128 genes (15%) in 21 individuals and identified variants of unknown significance for 19/128 genes (15%) in 23 individuals. Altogether, GREP queries for only 128 genes over a period of 18 months permitted a causal diagnosis to be established in 21/2875 undiagnosed affected probands (0.7%). Conclusion: The GREP query strategy is efficient and less tedious than complete periodic reanalysis. It is an interesting reanalysis strategy to improve diagnosis.

Low correlation between Ki67 assessed by qRT-PCR in Oncotype Dx score and Ki67 assessed by Immunohistochemistry.

Breast cancers expressing high levels of Ki67 are associated with poor outcomes. Oncotype DX test was designed for ER+/HER2- early-stage breast cancers to help adjuvant chemotherapy decision by providing a Recurrent Score (RS). RS measures the expression of 21 specific genes from tumor tissue, including Ki67. The primary aim of this study was to assess the agreement between Ki67RNA obtained with Oncotype DX RS and Ki67IHC. Other objectives were to analyze the association between the event free survival (EFS) and the expression level of Ki67RNA; and association between RS and Ki67RNA. Herein, we report a low agreement of 0.288 by Pearson correlation coefficient test between Ki67IHC and Ki67RNA in a cohort of 98 patients with early ER+/HER2- breast cancers. Moreover, Ki67RNAhigh tumors were significantly associated with the occurrence of events (p = 0.03). On the other hand, we did not find any association between Ki67IHC and EFS (p = 0.26). We observed a low agreement between expression level of Ki67RNA and Ki67 protein labelling by IHC. Unlike Ki67IHC and independently of the RS, Ki67RNA could have a prognostic value. It would be interesting to better assess the prognosis and predictive value of Ki67RNA measured by qRT-PCR. The Ki67RNA in medical routine could be a good support in countries where Oncotype DX is not accessible.

Human papillomavirus DNA and p16 expression in head and neck squamous cell carcinoma in young French patients.

OBJECTIVES: Human papillomavirus (HPV) is a risk factor for head and neck squamous cell carcinoma (HNSCC), which is currently increasing worldwide. We evaluated the prevalence of HPV DNA and p16 expression in HNSCC patients age <45 years compared with patients aged ≥45 years. METHODS: Thirty-nine patients aged <45 years who presented at Besançon University Hospital with HNSCC since 2005 were included in this retrospective study. HPV DNA was detected by HPV genotyping and p16 expression was determined by immunohistochemistry using paraffin-embedded tissues. A matched-group of 38 patients aged ≥45 years from Besançon University Hospital was included. RESULTS: The overall prevalence of HPV infection was 11.7%. HPV16 was the only genotype detected in 4/39 and 5/38 patients, and p16 was expressed in 6/39 and 4/38 patients aged <45 years and ≥45 years, respectively. CONCLUSIONS: HPV-positivity and p16 expression were similar in both age groups. The results suggest that p16 immunohistochemistry may provide a prognosis biomarker for all HNSCCs, not only oropharyngeal cancers, and this should be addressed in large clinical trials.

The NMD Pathway Regulates GABARAPL1 mRNA during the EMT.

EMT is a reversible cellular process that is linked to gene expression reprogramming, which allows for epithelial cells to undergo a phenotypic switch to acquire mesenchymal properties. EMT is associated with cancer progression and cancer therapeutic resistance and it is known that, during the EMT, many stress response pathways, such as autophagy and NMD, are dysregulated. Therefore, our goal was to study the regulation of ATG8 family members (GABARAP, GABARAPL1, LC3B) by the NMD and to identify molecular links between these two cellular processes that are involved in tumor development and metastasis formation. IHC experiments, which were conducted in a cohort of patients presenting lung adenocarcinomas, showed high GABARAPL1 and low UPF1 levels in EMT+ tumors. We observed increased levels of GABARAPL1 correlated with decreased levels of NMD factors in A549 cells in vitro. We then confirmed that GABARAPL1 mRNA was indeed targeted by the NMD in a 3'UTR-dependent manner and we identified four overlapping binding sites for UPF1 and eIF4A3 that are potentially involved in the recognition of this transcript by the NMD pathway. Our study suggests that 3'UTR-dependent NMD might be an important mechanism that is involved in the induction of autophagy and could represent a promising target in the development of new anti-cancer therapies.