A new NOTCH3 damaging variant in a thrombocytopenia family of Miao ethnic group.

BACKGROUND: Pediatric inherited thrombocytopenia, also known as a deficiency of platelets in children, is caused by genetic factors and it is hard to obtain an effective treatment. Thus, it is necessary to identify the possible genetic variants that are responsible for thrombocytopenia. METHODS: Whole exome sequencing was used to detect genetic variants in two members of a thrombocytopenia family of Miao ethnic group. Multiple in silico analyses were performed to evaluate the effects of the novel missense variants. RESULTS: Finally, a novel variant (chr19: g.15170364G>A) in the NOTCH3 gene was found, as confirmed with Sanger sequencing, which could result in a R1694Q substitution in the protein. This variant was consistently suggested to be damaging by sift (Sorting Tolerant From Intolerant; http://sift.jcvi.org), polyphen (Polymorphism Phenotyping, version 2.0; http://genetics.bwh.harvard.edu/pph2) and mutationtaster (http://www.mutationtaster.org) software. By building the 3D model of the key region of NOTCH3 protein and performing the structure simulation, we found that (i) this variant affected the 3D structure model with a root-mean-square deviation = 0.46 between wild-type and mutant type; (ii) this variant caused the protein to reduce the solvent accessible surface area by 421 Å2 ; and (iii) compared to the wild-type protein, the mutant protein had two less amino acids to maintain protein stability. CONCLUSIONS: A novel damaging variant in the NOTCH3 gene was identified in a thrombocytopenia family with respect to decreasing the stability of NOTCH3, which may help with the prognosis and therapy of inherited thrombocytopenia.

Blockage of PTPRJ promotes cell growth and resistance to 5-FU through activation of JAK1/STAT3 in the cervical carcinoma cell line C33A.

Gene therapy is a promising therapeutic approach for chemoresistant cervical cancers. Therapeutic interventions targeting the key factors contributing to the initiation and progression of cervical cancer may be a more effective treatment strategy. In the present study, we firstly determined the expression of protein tyrosine phosphatase receptor J (PTPRJ) in 8-paired human cervical tumor and non-tumor tissues. We observed a striking downregulation of PTPRJ in the human cervical tumor tissues. Next, we investigated the roles and the function mechanism of PTPRJ in the human cervical carcinoma cell line C33A by loss- and gain-of-function experiments. Our study indicated that C33A cells with loss of PTPRJ expression showed a significantly increased cell viability, rising growth and migration rate, as well as a G1-S transition. We obtained the opposite results when we overexpressed PTPRJ in C33A cells. Our further study indicated that PTPRJ levels were highly correlated with cell survival when the C33A cells were treated with 5-fluorouracil (5-FU), an important chemotherapeutic agent for cervical cancer. In addition, the signaling pathway screening assay showed an obvious alteration of the Janus kinase 1/signal transducer and activator of transcription 3 (JAK1/STAT3) pathway. PTPRJ negatively regulated the activation of the JAK1/STAT3 pathway by decreasing the phosphorylation levels of JAK1 and STAT3. In addition, PTPRJ also regulated the expression of the downstream factors of STAT3, such as cyclin D, Bax, VEGF and MMP2. Our results suggest that PTPRJ may be a promising gene therapy target and its therapeutic potential can be fulfilled when used alone, or in combination with other anticancer agents.