Correlation between integration of high-risk HPV genome into human DNA detected by molecular combing and the severity of cervical lesions: first results of the EXPL-HPV-002 study

OBJECTIVES

The aim of the EXPL-HPV-002 study is to evaluate the integration of 14 high-risk HPV as a biomarker of the severity and the progression of cervical lesions. Such a „triage biomarker“ would help to reduce the number of unnecessary colposcopies, to avoid over-treatment of lesions that spontaneously regress and to better target the lesions requiring treatment.

DESIGN

EXPL-HPV-002 is a prospective, open-label, single arm, GCP study conducted at 2 clinical sites in the Czech Republic.

SETTINGS

Investigations centers: Private Gynecology Center, Brno; Gynecological and Obstetrical Clinic, Brno; Genotyping central lab: NRL for Papillomaviruses and polyomaviruses, IHBT, Prague; Histology Central reading: Aeskulab Pathology, Prague; Molecular combing HPV test: Genomic Vision, Bagneux.

METHODS

From June 2016 to May 2018, 688 patients aged 25-65, referred to colposcopy after an abnormal Pap-smear, were enrolled in the study. Among them 60% were found HPV high-risk. The study is divided in two phases: 1. a cross-sectional phase using data collected at first visit (colposcopy images ± histology, pap-smear for HPV genotyping and molecular combing) to study the association between HPV integration status versus colposcopy and histology grades; 2. a longitudinal phase using data collected in follow-up visits: cytology at 6, 18 and 30 months and colposcopy ± histology at 12, 24 and 36 months. A pap-smear collected at 12, 24 and 36 months allows to perform genotyping and molecular combing. HPV integration status is analyzed in comparison with the evolution of lesions, viral clearance and HPV genotype. HPV genotyping and molecular combing were performed on pap-smear samples in central laboratories. Histology data were reviewed by central reading.

RESULTS

The transversal phase of the study is achieved and shows that the HPV integration into the human DNA, monitored by molecular combing, can significantly differentiate normal subjects from women with cervical lesions or cancer.

CONCLUSION

HPV integration into the host genome, monitored by Genomic Visions technology, is a reliable diagnostic biomarker that will greatly help clinicians to improve their medical decision tree.

Characterization of promoter regulatory elements involved in downexpression of the DNA polymerase kappa in colorectal cancer

The low-fidelity DNA polymerases thought to be specialized in DNA damage processing are frequently misregulated in cancers. We show here that DNA polymerase kappa (polkappa), prone to replicate across oxidative and aromatic adducts and known to function in nucleotide excision repair (NER), is downregulated in colorectal tumour biopsies. Contrary to the replicative poldelta and polalpha, for which only activating domains were described, we identified an upstream 465-bp-long repressor region in the promoter of POLK. We also found an activating 237-bp region that includes stimulating protein-1 (SP1) and cyclic AMP-responsive element (CRE)-binding sites. Mutations at one CRE-binding site led to a dramatic 80% decrease in promoter activity. Alterations of the SP1-binding site also affected, to a lesser extent, the transcription. Gel shift assays confirmed the role played by CRE/SP1 recognition sequences. Moreover, ectopic expression of SP1 or CRE-binding protein (CREB) protein favoured polkappa transcription. Finally, we found that polkappa downexpression in colorectal biopsies correlated with a decreased level of CREB and SP1 transcripts. This work shows that the promoter of POLK is cis-controlled and suggests that silencing of CREB and SP1 proteins could contribute to downregulation of this repair polymerase in colorectal tumours.

Jumping translocation in acute leukemia of myelomonocytic lineage: a case report and review of the literature

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[A new observation of an H-Y antigen positive 46, XX male (author's transl)]

A new serologic test for detecting the H-Y antigen by indirect fluorescence performed on purified lymphocytes was developed. It allowed us to demonstrate H-Y antigen in an 46, XX male. The presence of this antigen explains why the primitive gonad underwent testicular differentiation. Several mechanisms could account for the presence of H-Y antigen. Mosaicism or translocation of an X on a Y or an autosome may prevent detection of a Y chromosome. Alternatively, a Y chromosome may have disappeared during embryogenesis, The last hypothesis suggests that an autosome may carry a structural gene coding for H-Y antigen; in this case thye Y chromosome would act only as an accessory regulating gene.