Genetic basis of neurodevelopmental disorders in 103 Jordanian families.

We recruited 103 families from Jordan with neurodevelopmental disorders (NDD) and patterns of inheritance mostly suggestive of autosomal recessive inheritance. In each family, we investigated at least one affected individual using exome sequencing and an in-house diagnostic variant interpretation pipeline including a search for copy number variation. This approach led us to identify the likely molecular defect in established disease genes in 37 families. We could identify 25 pathogenic nonsense and 11 missense variants as well as 3 pathogenic copy number variants and 1 repeat expansion. Notably, 11 of the disease-causal variants occurred de novo. In addition, we prioritized a homozygous frameshift variant in PUS3 in two sisters with intellectual disability. To our knowledge, PUS3 has been postulated only recently as a candidate disease gene for intellectual disability in a single family with three affected siblings. Our findings provide additional evidence to establish loss of PUS3 function as a cause of intellectual disability.

ATP chemosensitivity testing of new antitumor duplex drugs linking 3`-C-ethynylycytidine (ECyd) and 2´-deoxy-5-fluorouridine (5-FdU) in comparison to standard cytostatica and combinations thereof.

BACKGROUND: 2´-Deoxy-5-fluorouridylyl-(5´-5´)-3´-C-ethynylcytidine [5-FdU(5´-5´)ECyd] and 3´-C-ethynylcytidinylyl-(5´->1-O)-2-O-octadecyl-sn-glycerylyl-(3-Ο->5´)-2´-deoxy-5-fluorouridine [ECyd-lipid-5-FdU] are antitumor active duplex drugs and these heterodinucleoside phosphate analogues could be cleaved in vivo by wide-spread phosphodiesterases into different antitumor active antimetabolites. METHODS: We cultured breast MCF-7, MDA-MB-231 and ovarian OVCAR-29 and OAW-42 cancer cell lines and used the luminometric measuring of the ATP tumor chemosensitivity assay to assess the in vitro activity of 5-FdU(5´-5´)ECyd and ECyd-lipid-5-FdU in comparison to standard single cytostatic agents and combinations thereof currently used in anticancer therapies. To allow comparison between samples and different regimens IndexSUM was determined based on the percentage tumor cell growth inhibition at each test drug concentration. Additionally, the cytostatic efficacy of 5-FdU(5´-5´)ECyd and ECyd-lipid-5-FdU was evaluated at a minimum of five concentrations at 10 fold dilutions using 60 human tumor cell lines including ovarian and breast cancer cell lines from the National Cancer Institute (USA). RESULTS: 5-FdU(5´-5´)ECyd and ECyd-lipid-5-FdU have a high cytostatic efficacy reaching 50% tumor cell growth inhibition at concentrations ranging between nano- and micomolar. IndexSum values for broad range efficacy in MCF-7 breast cancer cells were comparable to values obtained for standard drug combinations. Higher cytostatic efficacy was observed in MDA-MB-231 cells. CONCLUSION: The duplex drugs 5-FdU(5´-5´)ECyd and ECyd-lipid-5-FdU represent potential new chemotherapeutic drugs for breast and ovarian cancer cells which are comparable to currently used drug combinations and more potent in comparison to some monocytostatica used in cancer therapy.

Dynamics of cell-free tumour DNA correlate with treatment response of head and neck cancer patients receiving radiochemotherapy.

PURPOSE: Definitive radiochemotherapy (RCTX) with curative intent is one of the standard treatment options in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Despite this intensive therapy protocol, disease recurrence remains an issue. Therefore, we tested the predictive capacity of liquid biopsies as a novel biomarker during RCTX in patients with HNSCC. MATERIAL AND METHODS: We sequenced the tumour samples of 20 patients with locally advanced HNSCC to identify driver mutations. Subsequently, we performed a longitudinal analysis of circulating tumour DNA (ctDNA) dynamics during RCTX. Deep sequencing and UMI-based error suppression for the identification of driver mutations and HPV levels in the plasma enabled treatment-response monitoring prior, during and after RCTX. RESULTS: In 85% of all patients ctDNA was detectable, showing a significant correlation with the gross tumour volume (p-value 0.032). Additionally, the tumour allele fraction in the plasma was negatively correlated with the course of treatment (p-value <0.05). If ctDNA was detectable at the first follow-up, disease recurrence was seen later on. Circulating HPV DNA (cvDNA) could be detected in three patients at high levels, showing a similar dynamic behaviour to the ctDNA throughout treatment, and disappeared after treatment. CONCLUSIONS: Monitoring RCTX treatment-response using liquid biopsy in patients with locally advanced HNSCC is feasible. CtDNA can be seen as a surrogate marker of disease burden, tightly correlating with the gross tumour volume prior to the treatment start. The observed kinetic of ctDNA and cvDNA showed a negative correlation with time and treatment dosage in most patients.