The Role And Mechanism Of FANCD2 Gene In The Recurrence And Metastasis Of Cervical Cancer

Cervical cancer recurrence is characterized by rapid progression and extremely poor prognosis following initial surgery,radiation and chemotherapies,and a leading cause of cervical cancer deaths in women worldwide.The pathogenesis of cervical cancer recurrence is poorly understood.To investinate the genomic landscape of cervical cancer recurrence,we carried out clinical genomic study of 82 cervical cancer patients who received radical surgery and postoperative radiotherapy,including 10 patients with cervical cancer recurrence.We successfully obtained whole-exome sequencing results from paraffin embeded surgical specimens and generated the somatic mutation landscape of the clinical cohort.Our analyses identified the top 12 mutated genes(including EP300,PIK3CA,FBXW7,PTEN,RBI,TP53,MSH2,STK11,MBD1,SMAD4,PIK3R1 and ABI1).We further identified that mutations of Cul3,KEAP1,TP53 and RB1 are highly associated with cervical cancer recurrence and significantly associated with poor prognosis of cervical cancer.Importantly our results uncovered high frequent mutations of FANCD2(5/10)in patients with cervical cancer recurrence,often as genomic deletions of FANCD2(4/10).FANCD2 is a key regulator in response to DNA damage and plays critical roles in DNA interstrand crosslinking repairing and fanconi anemia(FA)pathway.Patients with FANCD2 deletion have significantly worse survival outcome than other patients.To further investigate the molecular mechanism of FANCD2 deficiency in radiation and chemotherapy sensitivity,we carried out CRISPR/Cas9 mediated FANCD2 mutations in human embryogenic kidney HEK293T cells.Based on the functional domains of FANCD2 protein,we designed sgRNAs targeting exon 2,exon 9 and exon 10,respectively,and generated a series of FANCD2 deficient cell lines.We further characterized these cell lines by genomic PCR and DNA sequencing.Collectively our results identified FANCD2 as a strong candidate biomarker for precise diagnosis and treatment of cervical cancer recurrence.